Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

41 files changed, 21063 insertions, 0 deletions

diff --git a/third_party/rust/neqo-http3/src/buffered_send_stream.rs b/third_party/rust/neqo-http3/src/buffered_send_stream.rs
new file mode 100644
index 0000000000..4f6761fa80
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/buffered_send_stream.rs
@@ -0,0 +1,118 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use neqo_common::qtrace;
+use neqo_transport::{Connection, StreamId};
+
+use crate::Res;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum BufferedStream {
+    Uninitialized,
+    Initialized { stream_id: StreamId, buf: Vec<u8> },
+}
+
+impl Default for BufferedStream {
+    fn default() -> Self {
+        Self::Uninitialized
+    }
+}
+
+impl ::std::fmt::Display for BufferedStream {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "BufferedStream {:?}", Option::<StreamId>::from(self))
+    }
+}
+
+impl BufferedStream {
+    #[must_use]
+    pub fn new(stream_id: StreamId) -> Self {
+        Self::Initialized {
+            stream_id,
+            buf: Vec::new(),
+        }
+    }
+
+    /// # Panics
+    ///
+    /// If the `BufferedStream` is initialized more than one it will panic.
+    pub fn init(&mut self, stream_id: StreamId) {
+        debug_assert!(&Self::Uninitialized == self);
+        *self = Self::Initialized {
+            stream_id,
+            buf: Vec::new(),
+        };
+    }
+
+    /// # Panics
+    ///
+    /// This functon cannot be called before the `BufferedStream` is initialized.
+    pub fn buffer(&mut self, to_buf: &[u8]) {
+        if let Self::Initialized { buf, .. } = self {
+            buf.extend_from_slice(to_buf);
+        } else {
+            debug_assert!(false, "Do not buffer date before the stream is initialized");
+        }
+    }
+
+    /// # Errors
+    ///
+    /// Returns `neqo_transport` errors.
+    pub fn send_buffer(&mut self, conn: &mut Connection) -> Res<usize> {
+        let label = ::neqo_common::log_subject!(::log::Level::Debug, self);
+        let mut sent = 0;
+        if let Self::Initialized { stream_id, buf } = self {
+            if !buf.is_empty() {
+                qtrace!([label], "sending data.");
+                sent = conn.stream_send(*stream_id, &buf[..])?;
+                if sent == buf.len() {
+                    buf.clear();
+                } else {
+                    let b = buf.split_off(sent);
+                    *buf = b;
+                }
+            }
+        }
+        Ok(sent)
+    }
+
+    /// # Errors
+    ///
+    /// Returns `neqo_transport` errors.
+    pub fn send_atomic(&mut self, conn: &mut Connection, to_send: &[u8]) -> Res<bool> {
+        // First try to send anything that is in the buffer.
+        self.send_buffer(conn)?;
+        if let Self::Initialized { stream_id, buf } = self {
+            if buf.is_empty() {
+                let res = conn.stream_send_atomic(*stream_id, to_send)?;
+                Ok(res)
+            } else {
+                Ok(false)
+            }
+        } else {
+            Ok(false)
+        }
+    }
+
+    #[must_use]
+    pub fn has_buffered_data(&self) -> bool {
+        if let Self::Initialized { buf, .. } = self {
+            !buf.is_empty()
+        } else {
+            false
+        }
+    }
+}
+
+impl From<&BufferedStream> for Option<StreamId> {
+    fn from(stream: &BufferedStream) -> Option<StreamId> {
+        if let BufferedStream::Initialized { stream_id, .. } = stream {
+            Some(*stream_id)
+        } else {
+            None
+        }
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/client_events.rs b/third_party/rust/neqo-http3/src/client_events.rs
new file mode 100644
index 0000000000..4b2ebc6c30
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/client_events.rs
@@ -0,0 +1,379 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{cell::RefCell, collections::VecDeque, rc::Rc};
+
+use neqo_common::{event::Provider as EventProvider, Header};
+use neqo_crypto::ResumptionToken;
+use neqo_transport::{AppError, StreamId, StreamType};
+
+use crate::{
+    connection::Http3State,
+    features::extended_connect::{ExtendedConnectEvents, ExtendedConnectType, SessionCloseReason},
+    settings::HSettingType,
+    CloseType, Http3StreamInfo, HttpRecvStreamEvents, RecvStreamEvents, SendStreamEvents,
+};
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum WebTransportEvent {
+    Negotiated(bool),
+    Session {
+        stream_id: StreamId,
+        status: u16,
+        headers: Vec<Header>,
+    },
+    SessionClosed {
+        stream_id: StreamId,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    },
+    NewStream {
+        stream_id: StreamId,
+        session_id: StreamId,
+    },
+    Datagram {
+        session_id: StreamId,
+        datagram: Vec<u8>,
+    },
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum Http3ClientEvent {
+    /// Response headers are received.
+    HeaderReady {
+        stream_id: StreamId,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    },
+    /// A stream can accept new data.
+    DataWritable { stream_id: StreamId },
+    /// New bytes available for reading.
+    DataReadable { stream_id: StreamId },
+    /// Peer reset the stream or there was an parsing error.
+    Reset {
+        stream_id: StreamId,
+        error: AppError,
+        local: bool,
+    },
+    /// Peer has sent a STOP_SENDING.
+    StopSending {
+        stream_id: StreamId,
+        error: AppError,
+    },
+    /// A new push promise.
+    PushPromise {
+        push_id: u64,
+        request_stream_id: StreamId,
+        headers: Vec<Header>,
+    },
+    /// A push response headers are ready.
+    PushHeaderReady {
+        push_id: u64,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    },
+    /// New bytes are available on a push stream for reading.
+    PushDataReadable { push_id: u64 },
+    /// A push has been canceled.
+    PushCanceled { push_id: u64 },
+    /// A push stream was been reset due to a HttpGeneralProtocol error.
+    /// Most common case are malformed response headers.
+    PushReset { push_id: u64, error: AppError },
+    /// New stream can be created
+    RequestsCreatable,
+    /// Cert authentication needed
+    AuthenticationNeeded,
+    /// Encrypted client hello fallback occurred.  The certificate for the
+    /// name `public_name` needs to be authenticated in order to get
+    /// an updated ECH configuration.
+    EchFallbackAuthenticationNeeded { public_name: String },
+    /// A new resumption token.
+    ResumptionToken(ResumptionToken),
+    /// Zero Rtt has been rejected.
+    ZeroRttRejected,
+    /// Client has received a GOAWAY frame
+    GoawayReceived,
+    /// Connection state change.
+    StateChange(Http3State),
+    /// WebTransport events
+    WebTransport(WebTransportEvent),
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct Http3ClientEvents {
+    events: Rc<RefCell<VecDeque<Http3ClientEvent>>>,
+}
+
+impl RecvStreamEvents for Http3ClientEvents {
+    /// Add a new `DataReadable` event
+    fn data_readable(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ClientEvent::DataReadable {
+            stream_id: stream_info.stream_id(),
+        });
+    }
+
+    /// Add a new `Reset` event.
+    fn recv_closed(&self, stream_info: Http3StreamInfo, close_type: CloseType) {
+        let stream_id = stream_info.stream_id();
+        let (local, error) = match close_type {
+            CloseType::ResetApp(_) => {
+                self.remove_recv_stream_events(stream_id);
+                return;
+            }
+            CloseType::Done => return,
+            CloseType::ResetRemote(e) => {
+                self.remove_recv_stream_events(stream_id);
+                (false, e)
+            }
+            CloseType::LocalError(e) => {
+                self.remove_recv_stream_events(stream_id);
+                (true, e)
+            }
+        };
+
+        self.insert(Http3ClientEvent::Reset {
+            stream_id,
+            error,
+            local,
+        });
+    }
+}
+
+impl HttpRecvStreamEvents for Http3ClientEvents {
+    /// Add a new `HeaderReady` event.
+    fn header_ready(
+        &self,
+        stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    ) {
+        self.insert(Http3ClientEvent::HeaderReady {
+            stream_id: stream_info.stream_id(),
+            headers,
+            interim,
+            fin,
+        });
+    }
+}
+
+impl SendStreamEvents for Http3ClientEvents {
+    /// Add a new `DataWritable` event.
+    fn data_writable(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ClientEvent::DataWritable {
+            stream_id: stream_info.stream_id(),
+        });
+    }
+
+    fn send_closed(&self, stream_info: Http3StreamInfo, close_type: CloseType) {
+        let stream_id = stream_info.stream_id();
+        self.remove_send_stream_events(stream_id);
+        if let CloseType::ResetRemote(error) = close_type {
+            self.insert(Http3ClientEvent::StopSending { stream_id, error });
+        }
+    }
+}
+
+impl ExtendedConnectEvents for Http3ClientEvents {
+    fn session_start(
+        &self,
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        status: u16,
+        headers: Vec<Header>,
+    ) {
+        if connect_type == ExtendedConnectType::WebTransport {
+            self.insert(Http3ClientEvent::WebTransport(WebTransportEvent::Session {
+                stream_id,
+                status,
+                headers,
+            }));
+        } else {
+            unreachable!("There is only ExtendedConnectType::WebTransport.");
+        }
+    }
+
+    fn session_end(
+        &self,
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    ) {
+        if connect_type == ExtendedConnectType::WebTransport {
+            self.insert(Http3ClientEvent::WebTransport(
+                WebTransportEvent::SessionClosed {
+                    stream_id,
+                    reason,
+                    headers,
+                },
+            ));
+        } else {
+            unreachable!("There are no other types.");
+        }
+    }
+
+    fn extended_connect_new_stream(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ClientEvent::WebTransport(
+            WebTransportEvent::NewStream {
+                stream_id: stream_info.stream_id(),
+                session_id: stream_info.session_id().unwrap(),
+            },
+        ));
+    }
+
+    fn new_datagram(&self, session_id: StreamId, datagram: Vec<u8>) {
+        self.insert(Http3ClientEvent::WebTransport(
+            WebTransportEvent::Datagram {
+                session_id,
+                datagram,
+            },
+        ));
+    }
+}
+
+impl Http3ClientEvents {
+    pub fn push_promise(&self, push_id: u64, request_stream_id: StreamId, headers: Vec<Header>) {
+        self.insert(Http3ClientEvent::PushPromise {
+            push_id,
+            request_stream_id,
+            headers,
+        });
+    }
+
+    pub fn push_canceled(&self, push_id: u64) {
+        self.remove_events_for_push_id(push_id);
+        self.insert(Http3ClientEvent::PushCanceled { push_id });
+    }
+
+    pub fn push_reset(&self, push_id: u64, error: AppError) {
+        self.remove_events_for_push_id(push_id);
+        self.insert(Http3ClientEvent::PushReset { push_id, error });
+    }
+
+    /// Add a new `RequestCreatable` event
+    pub(crate) fn new_requests_creatable(&self, stream_type: StreamType) {
+        if stream_type == StreamType::BiDi {
+            self.insert(Http3ClientEvent::RequestsCreatable);
+        }
+    }
+
+    /// Add a new `AuthenticationNeeded` event
+    pub(crate) fn authentication_needed(&self) {
+        self.insert(Http3ClientEvent::AuthenticationNeeded);
+    }
+
+    /// Add a new `AuthenticationNeeded` event
+    pub(crate) fn ech_fallback_authentication_needed(&self, public_name: String) {
+        self.insert(Http3ClientEvent::EchFallbackAuthenticationNeeded { public_name });
+    }
+
+    /// Add a new resumption token event.
+    pub(crate) fn resumption_token(&self, token: ResumptionToken) {
+        self.insert(Http3ClientEvent::ResumptionToken(token));
+    }
+
+    /// Add a new `ZeroRttRejected` event.
+    pub(crate) fn zero_rtt_rejected(&self) {
+        self.insert(Http3ClientEvent::ZeroRttRejected);
+    }
+
+    /// Add a new `GoawayReceived` event.
+    pub(crate) fn goaway_received(&self) {
+        self.remove(|evt| matches!(evt, Http3ClientEvent::RequestsCreatable));
+        self.insert(Http3ClientEvent::GoawayReceived);
+    }
+
+    pub fn insert(&self, event: Http3ClientEvent) {
+        self.events.borrow_mut().push_back(event);
+    }
+
+    fn remove<F>(&self, f: F)
+    where
+        F: Fn(&Http3ClientEvent) -> bool,
+    {
+        self.events.borrow_mut().retain(|evt| !f(evt));
+    }
+
+    /// Add a new `StateChange` event.
+    pub(crate) fn connection_state_change(&self, state: Http3State) {
+        match state {
+            // If closing, existing events no longer relevant.
+            Http3State::Closing { .. } | Http3State::Closed(_) => self.events.borrow_mut().clear(),
+            Http3State::Connected => {
+                self.remove(|evt| {
+                    matches!(evt, Http3ClientEvent::StateChange(Http3State::ZeroRtt))
+                });
+            }
+            _ => (),
+        }
+        self.insert(Http3ClientEvent::StateChange(state));
+    }
+
+    /// Remove all events for a stream
+    fn remove_recv_stream_events(&self, stream_id: StreamId) {
+        self.remove(|evt| {
+            matches!(evt,
+                Http3ClientEvent::HeaderReady { stream_id: x, .. }
+                | Http3ClientEvent::DataReadable { stream_id: x }
+                | Http3ClientEvent::PushPromise { request_stream_id: x, .. }
+                | Http3ClientEvent::Reset { stream_id: x, .. } if *x == stream_id)
+        });
+    }
+
+    fn remove_send_stream_events(&self, stream_id: StreamId) {
+        self.remove(|evt| {
+            matches!(evt,
+                Http3ClientEvent::DataWritable { stream_id: x }
+                | Http3ClientEvent::StopSending { stream_id: x, .. } if *x == stream_id)
+        });
+    }
+
+    pub fn has_push(&self, push_id: u64) -> bool {
+        for iter in &*self.events.borrow() {
+            if matches!(iter, Http3ClientEvent::PushPromise{push_id:x, ..} if *x == push_id) {
+                return true;
+            }
+        }
+        false
+    }
+
+    pub fn remove_events_for_push_id(&self, push_id: u64) {
+        self.remove(|evt| {
+            matches!(evt,
+                Http3ClientEvent::PushPromise{ push_id: x, .. }
+                | Http3ClientEvent::PushHeaderReady{ push_id: x, .. }
+                | Http3ClientEvent::PushDataReadable{ push_id: x, .. }
+                | Http3ClientEvent::PushCanceled{ push_id: x, .. } if *x == push_id)
+        });
+    }
+
+    pub fn negotiation_done(&self, feature_type: HSettingType, succeeded: bool) {
+        if feature_type == HSettingType::EnableWebTransport {
+            self.insert(Http3ClientEvent::WebTransport(
+                WebTransportEvent::Negotiated(succeeded),
+            ));
+        }
+    }
+}
+
+impl EventProvider for Http3ClientEvents {
+    type Event = Http3ClientEvent;
+
+    /// Check if there is any event present.
+    fn has_events(&self) -> bool {
+        !self.events.borrow().is_empty()
+    }
+
+    /// Take the first event.
+    fn next_event(&mut self) -> Option<Self::Event> {
+        self.events.borrow_mut().pop_front()
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/conn_params.rs b/third_party/rust/neqo-http3/src/conn_params.rs
new file mode 100644
index 0000000000..23a5d2cc67
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/conn_params.rs
@@ -0,0 +1,136 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cmp::min;
+
+use neqo_qpack::QpackSettings;
+use neqo_transport::ConnectionParameters;
+
+const QPACK_MAX_TABLE_SIZE_DEFAULT: u64 = 65536;
+const QPACK_TABLE_SIZE_LIMIT: u64 = (1 << 30) - 1;
+const QPACK_MAX_BLOCKED_STREAMS_DEFAULT: u16 = 20;
+const MAX_PUSH_STREAM_DEFAULT: u64 = 0;
+const WEBTRANSPORT_DEFAULT: bool = false;
+const HTTP3_DATAGRAM_DEFAULT: bool = false;
+
+#[derive(Debug, Clone)]
+pub struct Http3Parameters {
+    conn_params: ConnectionParameters,
+    qpack_settings: QpackSettings,
+    max_concurrent_push_streams: u64,
+    webtransport: bool,
+    http3_datagram: bool,
+}
+
+impl Default for Http3Parameters {
+    fn default() -> Self {
+        Self {
+            conn_params: ConnectionParameters::default(),
+            qpack_settings: QpackSettings {
+                max_table_size_encoder: QPACK_MAX_TABLE_SIZE_DEFAULT,
+                max_table_size_decoder: QPACK_MAX_TABLE_SIZE_DEFAULT,
+                max_blocked_streams: QPACK_MAX_BLOCKED_STREAMS_DEFAULT,
+            },
+            max_concurrent_push_streams: MAX_PUSH_STREAM_DEFAULT,
+            webtransport: WEBTRANSPORT_DEFAULT,
+            http3_datagram: HTTP3_DATAGRAM_DEFAULT,
+        }
+    }
+}
+
+impl Http3Parameters {
+    #[must_use]
+    pub fn get_connection_parameters(&self) -> &ConnectionParameters {
+        &self.conn_params
+    }
+
+    #[must_use]
+    pub fn connection_parameters(mut self, conn_params: ConnectionParameters) -> Self {
+        self.conn_params = conn_params;
+        self
+    }
+
+    /// # Panics
+    ///
+    /// The table size must be smaller than 1 << 30 by the spec.
+    #[must_use]
+    pub fn max_table_size_encoder(mut self, mut max_table: u64) -> Self {
+        assert!(max_table <= QPACK_TABLE_SIZE_LIMIT);
+        max_table = min(max_table, QPACK_TABLE_SIZE_LIMIT);
+        self.qpack_settings.max_table_size_encoder = max_table;
+        self
+    }
+
+    #[must_use]
+    pub fn get_max_table_size_encoder(&self) -> u64 {
+        self.qpack_settings.max_table_size_encoder
+    }
+
+    /// # Panics
+    ///
+    /// The table size must be smaller than 1 << 30 by the spec.
+    #[must_use]
+    pub fn max_table_size_decoder(mut self, mut max_table: u64) -> Self {
+        assert!(max_table <= QPACK_TABLE_SIZE_LIMIT);
+        max_table = min(max_table, QPACK_TABLE_SIZE_LIMIT);
+        self.qpack_settings.max_table_size_decoder = max_table;
+        self
+    }
+
+    #[must_use]
+    pub fn get_max_table_size_decoder(&self) -> u64 {
+        self.qpack_settings.max_table_size_decoder
+    }
+
+    #[must_use]
+    pub fn max_blocked_streams(mut self, max_blocked: u16) -> Self {
+        self.qpack_settings.max_blocked_streams = max_blocked;
+        self
+    }
+
+    #[must_use]
+    pub fn get_max_blocked_streams(&self) -> u16 {
+        self.qpack_settings.max_blocked_streams
+    }
+
+    #[must_use]
+    pub fn get_qpack_settings(&self) -> &QpackSettings {
+        &self.qpack_settings
+    }
+
+    #[must_use]
+    pub fn max_concurrent_push_streams(mut self, max_push_streams: u64) -> Self {
+        self.max_concurrent_push_streams = max_push_streams;
+        self
+    }
+
+    #[must_use]
+    pub fn get_max_concurrent_push_streams(&self) -> u64 {
+        self.max_concurrent_push_streams
+    }
+
+    #[must_use]
+    pub fn webtransport(mut self, webtransport: bool) -> Self {
+        self.webtransport = webtransport;
+        self
+    }
+
+    #[must_use]
+    pub fn get_webtransport(&self) -> bool {
+        self.webtransport
+    }
+
+    #[must_use]
+    pub fn http3_datagram(mut self, http3_datagram: bool) -> Self {
+        self.http3_datagram = http3_datagram;
+        self
+    }
+
+    #[must_use]
+    pub fn get_http3_datagram(&self) -> bool {
+        self.http3_datagram
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/connection.rs b/third_party/rust/neqo-http3/src/connection.rs
new file mode 100644
index 0000000000..bb2b5a6ce0
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/connection.rs
@@ -0,0 +1,1639 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{
+    cell::RefCell,
+    collections::{BTreeSet, HashMap},
+    fmt::Debug,
+    mem,
+    rc::Rc,
+};
+
+use neqo_common::{qdebug, qerror, qinfo, qtrace, qwarn, Decoder, Header, MessageType, Role};
+use neqo_qpack::{decoder::QPackDecoder, encoder::QPackEncoder};
+use neqo_transport::{
+    streams::SendOrder, AppError, Connection, ConnectionError, DatagramTracking, State, StreamId,
+    StreamType, ZeroRttState,
+};
+
+use crate::{
+    client_events::Http3ClientEvents,
+    control_stream_local::ControlStreamLocal,
+    control_stream_remote::ControlStreamRemote,
+    features::extended_connect::{
+        webtransport_session::WebTransportSession,
+        webtransport_streams::{WebTransportRecvStream, WebTransportSendStream},
+        ExtendedConnectEvents, ExtendedConnectFeature, ExtendedConnectType,
+    },
+    frames::HFrame,
+    push_controller::PushController,
+    qpack_decoder_receiver::DecoderRecvStream,
+    qpack_encoder_receiver::EncoderRecvStream,
+    recv_message::{RecvMessage, RecvMessageInfo},
+    request_target::{AsRequestTarget, RequestTarget},
+    send_message::SendMessage,
+    settings::{HSettingType, HSettings, HttpZeroRttChecker},
+    stream_type_reader::NewStreamHeadReader,
+    CloseType, Error, Http3Parameters, Http3StreamType, HttpRecvStreamEvents, NewStreamType,
+    Priority, PriorityHandler, ReceiveOutput, RecvStream, RecvStreamEvents, Res, SendStream,
+    SendStreamEvents,
+};
+
+pub(crate) struct RequestDescription<'b, 't, T>
+where
+    T: AsRequestTarget<'t> + ?Sized + Debug,
+{
+    pub method: &'b str,
+    pub connect_type: Option<ExtendedConnectType>,
+    pub target: &'t T,
+    pub headers: &'b [Header],
+    pub priority: Priority,
+}
+
+pub enum WebTransportSessionAcceptAction {
+    Accept,
+    Reject(Vec<Header>),
+}
+
+impl ::std::fmt::Display for WebTransportSessionAcceptAction {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        match self {
+            WebTransportSessionAcceptAction::Accept => f.write_str("Accept"),
+            WebTransportSessionAcceptAction::Reject(_) => f.write_str("Reject"),
+        }
+    }
+}
+
+#[derive(Debug)]
+enum Http3RemoteSettingsState {
+    NotReceived,
+    Received(HSettings),
+    ZeroRtt(HSettings),
+}
+
+/// States:
+/// - `Initializing`: this is the state during the QUIC handshake,
+/// - `ZeroRtt`: 0-RTT has been enabled and is active
+/// - Connected
+/// - GoingAway(StreamId): The connection has received a `GOAWAY` frame
+/// - Closing(ConnectionError): The connection is closed. The closing has been initiated by this end
+///   of the connection, e.g., the `CONNECTION_CLOSE` frame has been sent. In this state, the
+///   connection waits a certain amount of time to retransmit the `CONNECTION_CLOSE` frame if
+///   needed.
+/// - Closed(ConnectionError): This is the final close state: closing has been initialized by the
+///   peer and an ack for the `CONNECTION_CLOSE` frame has been sent or the closing has been
+///   initiated by this end of the connection and the ack for the `CONNECTION_CLOSE` has been
+///   received or the waiting time has passed.
+#[derive(Debug, PartialEq, PartialOrd, Ord, Eq, Clone)]
+pub enum Http3State {
+    Initializing,
+    ZeroRtt,
+    Connected,
+    GoingAway(StreamId),
+    Closing(ConnectionError),
+    Closed(ConnectionError),
+}
+
+impl Http3State {
+    #[must_use]
+    pub fn active(&self) -> bool {
+        matches!(
+            self,
+            Http3State::Connected | Http3State::GoingAway(_) | Http3State::ZeroRtt
+        )
+    }
+}
+
+/**
+# HTTP/3 core implementation
+
+This is the core implementation of HTTP/3 protocol. It implements most of the features of the
+protocol. `Http3Client` and `Http3ServerHandler` implement only client and server side behavior.
+
+The API consists of:
+- functions that correspond to the `Http3Client` and `Http3ServerHandler` API:
+  - `new`
+  - `close`
+  - `fetch` -  only used by the client-side implementation
+  - `read_data`
+  - `stream_reset_send`
+  - `stream_stop_sending`
+  - `cancel_fetch`
+  - `stream_close_send`
+- functions that correspond to [`WebTransport`](https://w3c.github.io/webtransport/) functions:
+  - `webtransport_create_session` -  only used by the client-side implementation
+  - `webtransport_session_accept` -  only used by the server-side implementation
+  - `webtransport_close_session`
+  - `webtransport_create_stream_local` -  this function is called when an application wants to open
+     a new `WebTransport` stream. For example `Http3Client::webtransport_create_stream` will call
+     this function.
+  - `webtransport_create_stream_remote` -  this is called when a `WebTransport` stream has been
+     opened by the peer and this function sets up the appropriate handler for the stream.
+- functions that are called by `process_http3`
+  - `process_sending` - some send-streams are buffered streams(see the Streams section) and this
+     function is called to trigger sending of the buffer data.
+- functions that are called to  handle `ConnectionEvent`s:
+  - `add_new_stream`
+  - `handle_stream_readable`
+  - `handle_stream_reset`
+  - `handle_stream_stop_sending`
+  - `handle_state_change`
+  - `handle_zero_rtt_rejected`
+- Additional functions:
+  - `set_features_listener`
+  - `stream_has_pending_data`
+  - `has_data_to_send`
+  - `add_streams`
+  - `add_recv_stream`
+  - `queue_control_frame`
+  - `queue_update_priority`
+  - `set_0rtt_settings`
+  - `get_settings`
+  - `state`
+  - `webtransport_enabled`
+
+## Streams
+
+Each `Http3Connection` holds a list of stream handlers. Each send and receive-handler is registered in
+`send_streams` and `recv_streams`. Unidirectional streams are registered only on one of the lists
+and bidirectional streams are registered in both lists and the 2 handlers are independent, e.g. one
+can be closed and removed ane second may still be active.
+
+The only streams that are not registered are the local control stream, local QPACK decoder stream,
+and local QPACK encoder stream. These streams are send-streams and sending data on this stream is
+handled a bit differently. This is done in the `process_sending` function, i.e. the control data is
+sent first and QPACK data is sent after regular stream data is sent because this stream may have
+new data only after regular streams are handled (TODO we may improve this a bit to send QPACK
+commands before headers.)
+
+There are the following types of streams:
+- `Control`: there is only a receiver stream of this type and the handler is `ControlStreamRemote`.
+- `Decoder`: there is only a receiver stream of this type and the handler is `DecoderRecvStream`.
+- `Encoder`: there is only a receiver stream of this type and the handler is `EncoderRecvStream`.
+- `NewStream`: there is only a receiver stream of this type and the handler is
+               `NewStreamHeadReader`.
+- `Http`: `SendMessage` and `RecvMessage` handlers are responsible for this type of streams.
+- `Push`: `RecvMessage` is responsible for this type of streams.
+- `ExtendedConnect`: `WebTransportSession` is responsible sender and receiver handler.
+- `WebTransport(StreamId)`: `WebTransportSendStream` and `WebTransportRecvStream` are responsible
+                            sender and receiver handler.
+- `Unknown`: These are all other stream types that are not unknown to the current implementation
+             and should be handled properly by the spec, e.g., in our implementation the streams are
+             reset.
+
+The streams are registered in `send_streams` and `recv_streams` in following ways depending if they
+are local or remote:
+- local streams:
+  - all local stream will be registered with the appropriate handler.
+- remote streams:
+  - all new incoming streams are registered with `NewStreamHeadReader`. This is triggered by
+    `ConnectionEvent::NewStream` and `add_new_stream` is called.
+  - reading from a `NewStreamHeadReader` stream, via the `receive` function, will decode a stream
+    type. `NewStreamHeadReader::receive` will return `ReceiveOutput::NewStream(_)` when a stream
+    type has been decoded.  After this point the stream:
+    - will be regegistered with the appropriate handler,
+    - will be canceled if is an unknown stream type or
+    - the connection will fail if it is unallowed stream type (receiveing HTTP request on the
+      client-side).
+    The output is handled in `handle_new_stream`, for control,  qpack streams and partially
+    `WebTransport` streams, otherwise the output is handled by `Http3Client` and `Http3ServerHandler`.
+
+
+### Receiving data
+
+Reading from a stream is triggered by `ConnectionEvent::RecvStreamReadable` events for the stream.
+The receive handler is retrieved from `recv_streams` and its `RecvStream::receive` function is
+called.
+
+Receiving data on `Http` streams is also triggered by the `read_data` function.
+`ConnectionEvent::RecvStreamReadable` events will trigger reading `HEADERS` frame and frame headers
+for `DATA` frames which will produce `Http3ClientEvent` or `Http3ServerEvent` events. The content of
+`DATA` frames is read by the application using the `read_data` function. The `read_data` function
+may read frame headers for consecutive `DATA` frames.
+
+On a `WebTransport(_)` stream data will be read only by the `read_data` function. The
+`RecvStream::receive` function only produces an `Http3ClientEvent` or `Http3ServerEvent` event.
+
+The `receive` and `read_data` functions may detect that the stream is done, e.g. FIN received. In
+this case, the stream will be removed from the `recv_stream` register, see `remove_recv_stream`.
+
+### Sending data
+
+All sender stream handlers have buffers. Data is first written into a buffer before being supplied
+to the QUIC layer. All data except the `DATA` frame and `WebTransport(_)`’s payload are written
+into the buffer. This includes stream type byte, e.g. `WEBTRANSPORT_STREAM` as well. In the case of
+`Http` and `WebTransport(_)` applications can write directly to the QUIC layer using the
+`send_data` function to avoid copying data. Sending data via the `send_data` function is only
+possible if there is no buffered data.
+
+If a stream has buffered data it will be registered in the `streams_with_pending_data` queue and
+actual sending will be performed in the `process_sending` function call. (This is done in this way,
+i.e. data is buffered first and then sent, for 2 reasons: in this way, sending will happen in a
+single function,  therefore error handling and clean up is easier and the QUIC layer may not be
+able to accept all data and being able to buffer data is required in any case.)
+
+The `send` and `send_data` functions may detect that the stream is closed and all outstanding data
+has been transferred to the QUIC layer. In this case, the stream will be removed from the
+`send_stream` register.
+
+### `ControlStreamRemote`
+
+The `ControlStreamRemote` handler uses `FrameReader` to read and decode frames received on the
+control frame. The `receive` returns `ReceiveOutput::ControlFrames(_)` with a list of control
+frames read (the list may be empty). The control frames are handled by `Http3Connection` and/or by
+`Http3Client` and `Http3ServerHandler`.
+
+### `DecoderRecvStream` and `EncoderRecvStream`
+
+The `receive` functions of these handlers call corresponding `receive` functions of `QPackDecoder`
+and `QPackDecoder`.
+
+`DecoderRecvStream` returns `ReceiveOutput::UnblockedStreams(_)` that may contain a list of stream
+ids that are unblocked by receiving qpack decoder commands. `Http3Connection` will handle this
+output by calling `receive` for the listed stream ids.
+
+`EncoderRecvStream` only returns `ReceiveOutput::NoOutput`.
+
+Both handlers may return an error that will close the connection.
+
+### `NewStreamHeadReader`
+
+A new incoming receiver stream registers a `NewStreamHeadReader` handler. This handler reads the
+first bytes of a stream to detect a stream type. The `receive` function returns
+`ReceiveOutput::NoOutput` if a stream type is still not known by reading the available stream data
+or `ReceiveOutput::NewStream(_)`. The handling of the output is explained above.
+
+### `SendMessage` and `RecvMessage`
+
+`RecvMessage::receive` only returns `ReceiveOutput::NoOutput`. It also have an event listener of
+type `HttpRecvStreamEvents`. The listener is called when headers are ready, or data is ready, etc.
+
+For example for `Http`   stream the listener will produce  `HeaderReady` and `DataReadable` events.
+
+### `WebTransportSession`
+
+A `WebTransport` session is connected to a control stream that is in essence an HTTP transaction.
+Therefore, `WebTransportSession` will internally use a `SendMessage` and `RecvMessage` handler to
+handle parsing and sending of HTTP part of the control stream. When HTTP headers are exchenged,
+`WebTransportSession` will take over handling of stream data. `WebTransportSession` sets
+`WebTransportSessionListener` as the `RecvMessage` event listener.
+
+`WebTransportSendStream` and `WebTransportRecvStream` are associated with a `WebTransportSession`
+and they will be canceled if the session is closed. To be avle to do this `WebTransportSession`
+holds a list of its active streams and clean up is done in `remove_extended_connect`.
+
+###  `WebTransportSendStream` and `WebTransportRecvStream`
+
+`WebTransport` streams are associated with a session. `WebTransportSendStream` and
+`WebTransportRecvStream` hold a reference to the session and are registered in the session upon
+ creation by `Http3Connection`. The `WebTransportSendStream` and `WebTransportRecvStream`
+ handlers will be unregistered from the session if they are closed, reset, or canceled.
+
+The call to function `receive` may produce `Http3ClientEvent::DataReadable`. Actual reading of
+data is done in the `read_data` function.
+*/
+#[derive(Debug)]
+pub(crate) struct Http3Connection {
+    role: Role,
+    pub state: Http3State,
+    local_params: Http3Parameters,
+    control_stream_local: ControlStreamLocal,
+    pub qpack_encoder: Rc<RefCell<QPackEncoder>>,
+    pub qpack_decoder: Rc<RefCell<QPackDecoder>>,
+    settings_state: Http3RemoteSettingsState,
+    streams_with_pending_data: BTreeSet<StreamId>,
+    pub send_streams: HashMap<StreamId, Box<dyn SendStream>>,
+    pub recv_streams: HashMap<StreamId, Box<dyn RecvStream>>,
+    webtransport: ExtendedConnectFeature,
+}
+
+impl ::std::fmt::Display for Http3Connection {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Http3 connection")
+    }
+}
+
+impl Http3Connection {
+    /// Create a new connection.
+    pub fn new(conn_params: Http3Parameters, role: Role) -> Self {
+        Self {
+            state: Http3State::Initializing,
+            control_stream_local: ControlStreamLocal::new(),
+            qpack_encoder: Rc::new(RefCell::new(QPackEncoder::new(
+                conn_params.get_qpack_settings(),
+                true,
+            ))),
+            qpack_decoder: Rc::new(RefCell::new(QPackDecoder::new(
+                conn_params.get_qpack_settings(),
+            ))),
+            webtransport: ExtendedConnectFeature::new(
+                ExtendedConnectType::WebTransport,
+                conn_params.get_webtransport(),
+            ),
+            local_params: conn_params,
+            settings_state: Http3RemoteSettingsState::NotReceived,
+            streams_with_pending_data: BTreeSet::new(),
+            send_streams: HashMap::new(),
+            recv_streams: HashMap::new(),
+            role,
+        }
+    }
+
+    /// This function is called when a not default feature needs to be negotiated. This is currently
+    /// only used for the `WebTransport` feature. The negotiation is done via the `SETTINGS` frame
+    /// and when the peer's `SETTINGS` frame has been received the listener will be called.
+    pub fn set_features_listener(&mut self, feature_listener: Http3ClientEvents) {
+        self.webtransport.set_listener(feature_listener);
+    }
+
+    /// This function creates and initializes, i.e. send stream type, the control and qpack
+    /// streams.
+    fn initialize_http3_connection(&mut self, conn: &mut Connection) -> Res<()> {
+        qinfo!([self], "Initialize the http3 connection.");
+        self.control_stream_local.create(conn)?;
+
+        self.send_settings();
+        self.create_qpack_streams(conn)?;
+        Ok(())
+    }
+
+    fn send_settings(&mut self) {
+        qdebug!([self], "Send settings.");
+        self.control_stream_local.queue_frame(&HFrame::Settings {
+            settings: HSettings::from(&self.local_params),
+        });
+        self.control_stream_local.queue_frame(&HFrame::Grease);
+    }
+
+    /// Save settings for adding to the session ticket.
+    pub(crate) fn save_settings(&self) -> Vec<u8> {
+        HttpZeroRttChecker::save(&self.local_params)
+    }
+
+    fn create_qpack_streams(&mut self, conn: &mut Connection) -> Res<()> {
+        qdebug!([self], "create_qpack_streams.");
+        self.qpack_encoder
+            .borrow_mut()
+            .add_send_stream(conn.stream_create(StreamType::UniDi)?);
+        self.qpack_decoder
+            .borrow_mut()
+            .add_send_stream(conn.stream_create(StreamType::UniDi)?);
+        Ok(())
+    }
+
+    /// Inform a `HttpConnection` that a stream has data to send and that `send` should be called
+    /// for the stream.
+    pub fn stream_has_pending_data(&mut self, stream_id: StreamId) {
+        self.streams_with_pending_data.insert(stream_id);
+    }
+
+    /// Return true if there is a stream that needs to send data.
+    pub fn has_data_to_send(&self) -> bool {
+        !self.streams_with_pending_data.is_empty()
+    }
+
+    /// This function calls the `send` function for all streams that have data to send. If a stream
+    /// has data to send it will be added to the `streams_with_pending_data` list.
+    ///
+    /// Control and QPACK streams are handled differently and are never added to the list.
+    fn send_non_control_streams(&mut self, conn: &mut Connection) -> Res<()> {
+        let to_send = mem::take(&mut self.streams_with_pending_data);
+        for stream_id in to_send {
+            let done = if let Some(s) = &mut self.send_streams.get_mut(&stream_id) {
+                s.send(conn)?;
+                if s.has_data_to_send() {
+                    self.streams_with_pending_data.insert(stream_id);
+                }
+                s.done()
+            } else {
+                false
+            };
+            if done {
+                self.remove_send_stream(stream_id, conn);
+            }
+        }
+        Ok(())
+    }
+
+    /// Call `send` for all streams that need to send data. See explanation for the main structure
+    /// for more details.
+    pub fn process_sending(&mut self, conn: &mut Connection) -> Res<()> {
+        // check if control stream has data to send.
+        self.control_stream_local
+            .send(conn, &mut self.recv_streams)?;
+
+        self.send_non_control_streams(conn)?;
+
+        self.qpack_decoder.borrow_mut().send(conn)?;
+        match self.qpack_encoder.borrow_mut().send_encoder_updates(conn) {
+            Ok(())
+            | Err(neqo_qpack::Error::EncoderStreamBlocked | neqo_qpack::Error::DynamicTableFull) => {
+            }
+            Err(e) => return Err(Error::QpackError(e)),
+        }
+        Ok(())
+    }
+
+    /// We have a resumption token which remembers previous settings. Update the setting.
+    pub fn set_0rtt_settings(&mut self, conn: &mut Connection, settings: HSettings) -> Res<()> {
+        self.initialize_http3_connection(conn)?;
+        self.set_qpack_settings(&settings)?;
+        self.settings_state = Http3RemoteSettingsState::ZeroRtt(settings);
+        self.state = Http3State::ZeroRtt;
+        Ok(())
+    }
+
+    /// Returns the settings for a connection. This is used for creating a resumption token.
+    pub fn get_settings(&self) -> Option<HSettings> {
+        if let Http3RemoteSettingsState::Received(settings) = &self.settings_state {
+            Some(settings.clone())
+        } else {
+            None
+        }
+    }
+
+    /// This is called when a `ConnectionEvent::NewStream` event is received. This register the
+    /// stream with a `NewStreamHeadReader` handler.
+    pub fn add_new_stream(&mut self, stream_id: StreamId) {
+        qtrace!([self], "A new stream: {}.", stream_id);
+        self.recv_streams.insert(
+            stream_id,
+            Box::new(NewStreamHeadReader::new(stream_id, self.role)),
+        );
+    }
+
+    /// The function calls `receive` for a stream. It also deals with the outcome of a read by
+    /// calling `handle_stream_manipulation_output`.
+    #[allow(clippy::option_if_let_else)] // False positive as borrow scope isn't lexical here.
+    fn stream_receive(&mut self, conn: &mut Connection, stream_id: StreamId) -> Res<ReceiveOutput> {
+        qtrace!([self], "Readable stream {}.", stream_id);
+
+        if let Some(recv_stream) = self.recv_streams.get_mut(&stream_id) {
+            let res = recv_stream.receive(conn);
+            return self
+                .handle_stream_manipulation_output(res, stream_id, conn)
+                .map(|(output, _)| output);
+        }
+        Ok(ReceiveOutput::NoOutput)
+    }
+
+    fn handle_unblocked_streams(
+        &mut self,
+        unblocked_streams: Vec<StreamId>,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        for stream_id in unblocked_streams {
+            qdebug!([self], "Stream {} is unblocked", stream_id);
+            if let Some(r) = self.recv_streams.get_mut(&stream_id) {
+                let res = r
+                    .http_stream()
+                    .ok_or(Error::HttpInternal(10))?
+                    .header_unblocked(conn);
+                let res = self.handle_stream_manipulation_output(res, stream_id, conn)?;
+                debug_assert!(matches!(res, (ReceiveOutput::NoOutput, _)));
+            }
+        }
+        Ok(())
+    }
+
+    /// This function handles reading from all streams, i.e. control, qpack, request/response
+    /// stream and unidi stream that are still do not have a type.
+    /// The function cannot handle:
+    /// 1) a `Push(_)`, `Htttp` or `WebTransportStream(_)` stream
+    /// 2) frames `MaxPushId`, `PriorityUpdateRequest`, `PriorityUpdateRequestPush` or `Goaway` must
+    ///    be handled by `Http3Client`/`Server`.
+    /// The function returns `ReceiveOutput`.
+    pub fn handle_stream_readable(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+    ) -> Res<ReceiveOutput> {
+        let mut output = self.stream_receive(conn, stream_id)?;
+
+        if let ReceiveOutput::NewStream(stream_type) = output {
+            output = self.handle_new_stream(conn, stream_type, stream_id)?;
+        }
+
+        #[allow(clippy::match_same_arms)] // clippy is being stupid here
+        match output {
+            ReceiveOutput::UnblockedStreams(unblocked_streams) => {
+                self.handle_unblocked_streams(unblocked_streams, conn)?;
+                Ok(ReceiveOutput::NoOutput)
+            }
+            ReceiveOutput::ControlFrames(mut control_frames) => {
+                let mut rest = Vec::new();
+                for cf in control_frames.drain(..) {
+                    if let Some(not_handled) = self.handle_control_frame(cf)? {
+                        rest.push(not_handled);
+                    }
+                }
+                Ok(ReceiveOutput::ControlFrames(rest))
+            }
+            ReceiveOutput::NewStream(
+                NewStreamType::Push(_) | NewStreamType::Http | NewStreamType::WebTransportStream(_),
+            ) => Ok(output),
+            ReceiveOutput::NewStream(_) => {
+                unreachable!("NewStream should have been handled already")
+            }
+            ReceiveOutput::NoOutput => Ok(output),
+        }
+    }
+
+    /// This is called when a RESET frame has been received.
+    pub fn handle_stream_reset(
+        &mut self,
+        stream_id: StreamId,
+        app_error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!(
+            [self],
+            "Handle a stream reset stream_id={} app_err={}",
+            stream_id,
+            app_error
+        );
+
+        self.close_recv(stream_id, CloseType::ResetRemote(app_error), conn)
+    }
+
+    pub fn handle_stream_stop_sending(
+        &mut self,
+        stream_id: StreamId,
+        app_error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!(
+            [self],
+            "Handle stream_stop_sending stream_id={} app_err={}",
+            stream_id,
+            app_error
+        );
+
+        if self.send_stream_is_critical(stream_id) {
+            return Err(Error::HttpClosedCriticalStream);
+        }
+
+        self.close_send(stream_id, CloseType::ResetRemote(app_error), conn);
+        Ok(())
+    }
+
+    /// This is called when `neqo_transport::Connection` state has been change to take proper
+    /// actions in the HTTP3 layer.
+    pub fn handle_state_change(&mut self, conn: &mut Connection, state: &State) -> Res<bool> {
+        qdebug!([self], "Handle state change {:?}", state);
+        match state {
+            State::Handshaking => {
+                if self.role == Role::Server
+                    && conn.zero_rtt_state() == ZeroRttState::AcceptedServer
+                {
+                    self.state = Http3State::ZeroRtt;
+                    self.initialize_http3_connection(conn)?;
+                    Ok(true)
+                } else {
+                    Ok(false)
+                }
+            }
+            State::Connected => {
+                debug_assert!(matches!(
+                    self.state,
+                    Http3State::Initializing | Http3State::ZeroRtt
+                ));
+                if self.state == Http3State::Initializing {
+                    self.initialize_http3_connection(conn)?;
+                }
+                self.state = Http3State::Connected;
+                Ok(true)
+            }
+            State::Closing { error, .. } | State::Draining { error, .. } => {
+                if matches!(self.state, Http3State::Closing(_) | Http3State::Closed(_)) {
+                    Ok(false)
+                } else {
+                    self.state = Http3State::Closing(error.clone());
+                    Ok(true)
+                }
+            }
+            State::Closed(error) => {
+                if matches!(self.state, Http3State::Closed(_)) {
+                    Ok(false)
+                } else {
+                    self.state = Http3State::Closed(error.clone());
+                    Ok(true)
+                }
+            }
+            _ => Ok(false),
+        }
+    }
+
+    /// This is called when 0RTT has been reset to clear `send_streams`, `recv_streams` and
+    /// settings.
+    pub fn handle_zero_rtt_rejected(&mut self) -> Res<()> {
+        if self.state == Http3State::ZeroRtt {
+            self.state = Http3State::Initializing;
+            self.control_stream_local = ControlStreamLocal::new();
+            self.qpack_encoder = Rc::new(RefCell::new(QPackEncoder::new(
+                self.local_params.get_qpack_settings(),
+                true,
+            )));
+            self.qpack_decoder = Rc::new(RefCell::new(QPackDecoder::new(
+                self.local_params.get_qpack_settings(),
+            )));
+            self.settings_state = Http3RemoteSettingsState::NotReceived;
+            self.streams_with_pending_data.clear();
+            // TODO: investigate whether this code can automatically retry failed transactions.
+            self.send_streams.clear();
+            self.recv_streams.clear();
+            Ok(())
+        } else {
+            debug_assert!(false, "Zero rtt rejected in the wrong state.");
+            Err(Error::HttpInternal(3))
+        }
+    }
+
+    pub fn handle_datagram(&mut self, datagram: &[u8]) {
+        let mut decoder = Decoder::new(datagram);
+        let session = decoder
+            .decode_varint()
+            .and_then(|id| self.recv_streams.get_mut(&StreamId::from(id * 4)))
+            .and_then(|stream| stream.webtransport());
+        if let Some(s) = session {
+            s.borrow_mut().datagram(decoder.decode_remainder().to_vec());
+        }
+    }
+
+    fn check_stream_exists(&self, stream_type: Http3StreamType) -> Res<()> {
+        if self
+            .recv_streams
+            .values()
+            .any(|c| c.stream_type() == stream_type)
+        {
+            Err(Error::HttpStreamCreation)
+        } else {
+            Ok(())
+        }
+    }
+
+    /// If the new stream is a control or QPACK stream, this function creates a proper handler
+    /// and perform a read.
+    /// if the new stream is a `Push(_)`, `Http` or `WebTransportStream(_)` stream, the function
+    /// returns `ReceiveOutput::NewStream(_)` and the caller will handle it.
+    /// If the stream is of a unknown type the stream will be closed.
+    fn handle_new_stream(
+        &mut self,
+        conn: &mut Connection,
+        stream_type: NewStreamType,
+        stream_id: StreamId,
+    ) -> Res<ReceiveOutput> {
+        match stream_type {
+            NewStreamType::Control => {
+                self.check_stream_exists(Http3StreamType::Control)?;
+                self.recv_streams
+                    .insert(stream_id, Box::new(ControlStreamRemote::new(stream_id)));
+            }
+
+            NewStreamType::Push(push_id) => {
+                qinfo!(
+                    [self],
+                    "A new push stream {} push_id:{}.",
+                    stream_id,
+                    push_id
+                );
+            }
+            NewStreamType::Decoder => {
+                qinfo!([self], "A new remote qpack encoder stream {}", stream_id);
+                self.check_stream_exists(Http3StreamType::Decoder)?;
+                self.recv_streams.insert(
+                    stream_id,
+                    Box::new(DecoderRecvStream::new(
+                        stream_id,
+                        Rc::clone(&self.qpack_decoder),
+                    )),
+                );
+            }
+            NewStreamType::Encoder => {
+                qinfo!([self], "A new remote qpack decoder stream {}", stream_id);
+                self.check_stream_exists(Http3StreamType::Encoder)?;
+                self.recv_streams.insert(
+                    stream_id,
+                    Box::new(EncoderRecvStream::new(
+                        stream_id,
+                        Rc::clone(&self.qpack_encoder),
+                    )),
+                );
+            }
+            NewStreamType::Http => {
+                qinfo!([self], "A new http stream {}.", stream_id);
+            }
+            NewStreamType::WebTransportStream(session_id) => {
+                let session_exists = self
+                    .send_streams
+                    .get(&StreamId::from(session_id))
+                    .map_or(false, |s| {
+                        s.stream_type() == Http3StreamType::ExtendedConnect
+                    });
+                if !session_exists {
+                    conn.stream_stop_sending(stream_id, Error::HttpStreamCreation.code())?;
+                    return Ok(ReceiveOutput::NoOutput);
+                }
+                // set incoming WebTransport streams to be fair (share bandwidth)
+                conn.stream_fairness(stream_id, true).ok();
+                qinfo!(
+                    [self],
+                    "A new WebTransport stream {} for session {}.",
+                    stream_id,
+                    session_id
+                );
+            }
+            NewStreamType::Unknown => {
+                conn.stream_stop_sending(stream_id, Error::HttpStreamCreation.code())?;
+            }
+        };
+
+        match stream_type {
+            NewStreamType::Control | NewStreamType::Decoder | NewStreamType::Encoder => {
+                self.stream_receive(conn, stream_id)
+            }
+            NewStreamType::Push(_) | NewStreamType::Http | NewStreamType::WebTransportStream(_) => {
+                Ok(ReceiveOutput::NewStream(stream_type))
+            }
+            NewStreamType::Unknown => Ok(ReceiveOutput::NoOutput),
+        }
+    }
+
+    /// This is called when an application closes the connection.
+    pub fn close(&mut self, error: AppError) {
+        qinfo!([self], "Close connection error {:?}.", error);
+        self.state = Http3State::Closing(ConnectionError::Application(error));
+        if (!self.send_streams.is_empty() || !self.recv_streams.is_empty()) && (error == 0) {
+            qwarn!("close(0) called when streams still active");
+        }
+        self.send_streams.clear();
+        self.recv_streams.clear();
+    }
+
+    /// This function will not handle the output of the function completely, but only
+    /// handle the indication that a stream is closed. There are 2 cases:
+    ///  - an error occurred or
+    ///  - the stream is done, i.e. the second value in `output` tuple is true if the stream is done
+    ///    and can be removed from the `recv_streams`
+    /// How it is handling `output`:
+    ///  - if the stream is done, it removes the stream from `recv_streams`
+    ///  - if the stream is not done and there is no error, return `output` and the caller will
+    ///    handle it.
+    ///  - in case of an error:
+    ///    - if it is only a stream error and the stream is not critical, send `STOP_SENDING` frame,
+    ///      remove the stream from `recv_streams` and inform the listener that the stream has been
+    ///      reset.
+    ///    - otherwise this is a connection error. In this case, propagate the error to the caller
+    ///      that will handle it properly.
+    fn handle_stream_manipulation_output<U>(
+        &mut self,
+        output: Res<(U, bool)>,
+        stream_id: StreamId,
+        conn: &mut Connection,
+    ) -> Res<(U, bool)>
+    where
+        U: Default,
+    {
+        match &output {
+            Ok((_, true)) => {
+                self.remove_recv_stream(stream_id, conn);
+            }
+            Ok((_, false)) => {}
+            Err(e) => {
+                if e.stream_reset_error() && !self.recv_stream_is_critical(stream_id) {
+                    mem::drop(conn.stream_stop_sending(stream_id, e.code()));
+                    self.close_recv(stream_id, CloseType::LocalError(e.code()), conn)?;
+                    return Ok((U::default(), false));
+                }
+            }
+        }
+        output
+    }
+
+    fn create_fetch_headers<'b, 't, T>(request: &RequestDescription<'b, 't, T>) -> Res<Vec<Header>>
+    where
+        T: AsRequestTarget<'t> + ?Sized + Debug,
+    {
+        let target = request
+            .target
+            .as_request_target()
+            .map_err(|_| Error::InvalidRequestTarget)?;
+
+        // Transform pseudo-header fields
+        let mut final_headers = vec![
+            Header::new(":method", request.method),
+            Header::new(":scheme", target.scheme()),
+            Header::new(":authority", target.authority()),
+            Header::new(":path", target.path()),
+        ];
+        if let Some(conn_type) = request.connect_type {
+            final_headers.push(Header::new(":protocol", conn_type.string()));
+        }
+
+        if let Some(priority_header) = request.priority.header() {
+            final_headers.push(priority_header);
+        }
+        final_headers.extend_from_slice(request.headers);
+        Ok(final_headers)
+    }
+
+    pub fn fetch<'b, 't, T>(
+        &mut self,
+        conn: &mut Connection,
+        send_events: Box<dyn SendStreamEvents>,
+        recv_events: Box<dyn HttpRecvStreamEvents>,
+        push_handler: Option<Rc<RefCell<PushController>>>,
+        request: &RequestDescription<'b, 't, T>,
+    ) -> Res<StreamId>
+    where
+        T: AsRequestTarget<'t> + ?Sized + Debug,
+    {
+        qinfo!(
+            [self],
+            "Fetch method={} target: {:?}",
+            request.method,
+            request.target,
+        );
+        let id = self.create_bidi_transport_stream(conn)?;
+        self.fetch_with_stream(id, conn, send_events, recv_events, push_handler, request)?;
+        Ok(id)
+    }
+
+    fn create_bidi_transport_stream(&self, conn: &mut Connection) -> Res<StreamId> {
+        // Requests cannot be created when a connection is in states: Initializing, GoingAway,
+        // Closing and Closed.
+        match self.state() {
+            Http3State::GoingAway(..) | Http3State::Closing(..) | Http3State::Closed(..) => {
+                return Err(Error::AlreadyClosed)
+            }
+            Http3State::Initializing => return Err(Error::Unavailable),
+            _ => {}
+        }
+
+        let id = conn
+            .stream_create(StreamType::BiDi)
+            .map_err(|e| Error::map_stream_create_errors(&e))?;
+        conn.stream_keep_alive(id, true)?;
+        Ok(id)
+    }
+
+    fn fetch_with_stream<'b, 't, T>(
+        &mut self,
+        stream_id: StreamId,
+        conn: &mut Connection,
+        send_events: Box<dyn SendStreamEvents>,
+        recv_events: Box<dyn HttpRecvStreamEvents>,
+        push_handler: Option<Rc<RefCell<PushController>>>,
+        request: &RequestDescription<'b, 't, T>,
+    ) -> Res<()>
+    where
+        T: AsRequestTarget<'t> + ?Sized + Debug,
+    {
+        let final_headers = Http3Connection::create_fetch_headers(request)?;
+
+        let stream_type = if request.connect_type.is_some() {
+            Http3StreamType::ExtendedConnect
+        } else {
+            Http3StreamType::Http
+        };
+
+        let mut send_message = SendMessage::new(
+            MessageType::Request,
+            stream_type,
+            stream_id,
+            self.qpack_encoder.clone(),
+            send_events,
+        );
+
+        send_message
+            .http_stream()
+            .unwrap()
+            .send_headers(&final_headers, conn)?;
+
+        self.add_streams(
+            stream_id,
+            Box::new(send_message),
+            Box::new(RecvMessage::new(
+                &RecvMessageInfo {
+                    message_type: MessageType::Response,
+                    stream_type,
+                    stream_id,
+                    header_frame_type_read: false,
+                },
+                Rc::clone(&self.qpack_decoder),
+                recv_events,
+                push_handler,
+                PriorityHandler::new(false, request.priority),
+            )),
+        );
+
+        // Call immediately send so that at least headers get sent. This will make Firefox faster,
+        // since it can send request body immediately in most cases and does not need to do
+        // a complete process loop.
+        self.send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .send(conn)?;
+        Ok(())
+    }
+
+    /// Stream data are read directly into a buffer supplied as a parameter of this function to
+    /// avoid copying data.
+    ///
+    /// # Errors
+    ///
+    /// It returns an error if a stream does not exist or an error happens while reading a stream,
+    /// e.g. early close, protocol error, etc.
+    pub fn read_data(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+        buf: &mut [u8],
+    ) -> Res<(usize, bool)> {
+        qinfo!([self], "read_data from stream {}.", stream_id);
+        let res = self
+            .recv_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .read_data(conn, buf);
+        self.handle_stream_manipulation_output(res, stream_id, conn)
+    }
+
+    /// This is called when an application resets a stream.
+    /// The application reset will close both sides.
+    pub fn stream_reset_send(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+        error: AppError,
+    ) -> Res<()> {
+        qinfo!(
+            [self],
+            "Reset sending side of stream {} error={}.",
+            stream_id,
+            error
+        );
+
+        if self.send_stream_is_critical(stream_id) {
+            return Err(Error::InvalidStreamId);
+        }
+
+        self.close_send(stream_id, CloseType::ResetApp(error), conn);
+        conn.stream_reset_send(stream_id, error)?;
+        Ok(())
+    }
+
+    pub fn stream_stop_sending(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+        error: AppError,
+    ) -> Res<()> {
+        qinfo!(
+            [self],
+            "Send stop sending for stream {} error={}.",
+            stream_id,
+            error
+        );
+        if self.recv_stream_is_critical(stream_id) {
+            return Err(Error::InvalidStreamId);
+        }
+
+        self.close_recv(stream_id, CloseType::ResetApp(error), conn)?;
+
+        // Stream may be already be closed and we may get an error here, but we do not care.
+        conn.stream_stop_sending(stream_id, error)?;
+        Ok(())
+    }
+
+    /// Set the stream `SendOrder`.
+    ///
+    /// # Errors
+    ///
+    /// Returns `InvalidStreamId` if the stream id doesn't exist
+    pub fn stream_set_sendorder(
+        conn: &mut Connection,
+        stream_id: StreamId,
+        sendorder: Option<SendOrder>,
+    ) -> Res<()> {
+        conn.stream_sendorder(stream_id, sendorder)
+            .map_err(|_| Error::InvalidStreamId)
+    }
+
+    /// Set the stream Fairness.   Fair streams will share bandwidth with other
+    /// streams of the same sendOrder group (or the unordered group).  Unfair streams
+    /// will give bandwidth preferentially to the lowest streamId with data to send.
+    ///
+    /// # Errors
+    ///
+    /// Returns `InvalidStreamId` if the stream id doesn't exist
+    pub fn stream_set_fairness(
+        conn: &mut Connection,
+        stream_id: StreamId,
+        fairness: bool,
+    ) -> Res<()> {
+        conn.stream_fairness(stream_id, fairness)
+            .map_err(|_| Error::InvalidStreamId)
+    }
+
+    pub fn cancel_fetch(
+        &mut self,
+        stream_id: StreamId,
+        error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!([self], "cancel_fetch {} error={}.", stream_id, error);
+        let send_stream = self.send_streams.get(&stream_id);
+        let recv_stream = self.recv_streams.get(&stream_id);
+        match (send_stream, recv_stream) {
+            (None, None) => return Err(Error::InvalidStreamId),
+            (Some(s), None) => {
+                if !matches!(
+                    s.stream_type(),
+                    Http3StreamType::Http | Http3StreamType::ExtendedConnect
+                ) {
+                    return Err(Error::InvalidStreamId);
+                }
+                // Stream may be already be closed and we may get an error here, but we do not care.
+                mem::drop(self.stream_reset_send(conn, stream_id, error));
+            }
+            (None, Some(s)) => {
+                if !matches!(
+                    s.stream_type(),
+                    Http3StreamType::Http
+                        | Http3StreamType::Push
+                        | Http3StreamType::ExtendedConnect
+                ) {
+                    return Err(Error::InvalidStreamId);
+                }
+
+                // Stream may be already be closed and we may get an error here, but we do not care.
+                mem::drop(self.stream_stop_sending(conn, stream_id, error));
+            }
+            (Some(s), Some(r)) => {
+                debug_assert_eq!(s.stream_type(), r.stream_type());
+                if !matches!(
+                    s.stream_type(),
+                    Http3StreamType::Http | Http3StreamType::ExtendedConnect
+                ) {
+                    return Err(Error::InvalidStreamId);
+                }
+                // Stream may be already be closed and we may get an error here, but we do not care.
+                mem::drop(self.stream_reset_send(conn, stream_id, error));
+                // Stream may be already be closed and we may get an error here, but we do not care.
+                mem::drop(self.stream_stop_sending(conn, stream_id, error));
+            }
+        }
+        Ok(())
+    }
+
+    /// This is called when an application wants to close the sending side of a stream.
+    pub fn stream_close_send(&mut self, conn: &mut Connection, stream_id: StreamId) -> Res<()> {
+        qinfo!([self], "Close the sending side for stream {}.", stream_id);
+        debug_assert!(self.state.active());
+        let send_stream = self
+            .send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?;
+        // The following function may return InvalidStreamId from the transport layer if the stream
+        // has been closed already. It is ok to ignore it here.
+        mem::drop(send_stream.close(conn));
+        if send_stream.done() {
+            self.remove_send_stream(stream_id, conn);
+        } else if send_stream.has_data_to_send() {
+            self.streams_with_pending_data.insert(stream_id);
+        }
+        Ok(())
+    }
+
+    pub fn webtransport_create_session<'x, 't: 'x, T>(
+        &mut self,
+        conn: &mut Connection,
+        events: Box<dyn ExtendedConnectEvents>,
+        target: &'t T,
+        headers: &'t [Header],
+    ) -> Res<StreamId>
+    where
+        T: AsRequestTarget<'x> + ?Sized + Debug,
+    {
+        qinfo!([self], "Create WebTransport");
+        if !self.webtransport_enabled() {
+            return Err(Error::Unavailable);
+        }
+
+        let id = self.create_bidi_transport_stream(conn)?;
+
+        let extended_conn = Rc::new(RefCell::new(WebTransportSession::new(
+            id,
+            events,
+            self.role,
+            Rc::clone(&self.qpack_encoder),
+            Rc::clone(&self.qpack_decoder),
+        )));
+        self.add_streams(
+            id,
+            Box::new(extended_conn.clone()),
+            Box::new(extended_conn.clone()),
+        );
+
+        let final_headers = Http3Connection::create_fetch_headers(&RequestDescription {
+            method: "CONNECT",
+            target,
+            headers,
+            connect_type: Some(ExtendedConnectType::WebTransport),
+            priority: Priority::default(),
+        })?;
+        extended_conn
+            .borrow_mut()
+            .send_request(&final_headers, conn)?;
+        self.streams_with_pending_data.insert(id);
+        Ok(id)
+    }
+
+    pub(crate) fn webtransport_session_accept(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+        events: Box<dyn ExtendedConnectEvents>,
+        accept_res: &WebTransportSessionAcceptAction,
+    ) -> Res<()> {
+        qtrace!(
+            "Respond to WebTransport session with accept={}.",
+            accept_res
+        );
+        if !self.webtransport_enabled() {
+            return Err(Error::Unavailable);
+        }
+        let mut recv_stream = self.recv_streams.get_mut(&stream_id);
+        if let Some(r) = &mut recv_stream {
+            if !r
+                .http_stream()
+                .ok_or(Error::InvalidStreamId)?
+                .extended_connect_wait_for_response()
+            {
+                return Err(Error::InvalidStreamId);
+            }
+        }
+
+        let send_stream = self.send_streams.get_mut(&stream_id);
+
+        match (send_stream, recv_stream, accept_res) {
+            (None, None, _) => Err(Error::InvalidStreamId),
+            (None, Some(_), _) | (Some(_), None, _) => {
+                // TODO this needs a better error
+                self.cancel_fetch(stream_id, Error::HttpRequestRejected.code(), conn)?;
+                Err(Error::InvalidStreamId)
+            }
+            (Some(s), Some(_r), WebTransportSessionAcceptAction::Reject(headers)) => {
+                if s.http_stream()
+                    .ok_or(Error::InvalidStreamId)?
+                    .send_headers(headers, conn)
+                    .is_ok()
+                {
+                    mem::drop(self.stream_close_send(conn, stream_id));
+                    // TODO issue 1294: add a timer to clean up the recv_stream if the peer does not
+                    // do that in a short time.
+                    self.streams_with_pending_data.insert(stream_id);
+                } else {
+                    self.cancel_fetch(stream_id, Error::HttpRequestRejected.code(), conn)?;
+                }
+                Ok(())
+            }
+            (Some(s), Some(_r), WebTransportSessionAcceptAction::Accept) => {
+                if s.http_stream()
+                    .ok_or(Error::InvalidStreamId)?
+                    .send_headers(&[Header::new(":status", "200")], conn)
+                    .is_ok()
+                {
+                    let extended_conn =
+                        Rc::new(RefCell::new(WebTransportSession::new_with_http_streams(
+                            stream_id,
+                            events,
+                            self.role,
+                            self.recv_streams.remove(&stream_id).unwrap(),
+                            self.send_streams.remove(&stream_id).unwrap(),
+                        )));
+                    self.add_streams(
+                        stream_id,
+                        Box::new(extended_conn.clone()),
+                        Box::new(extended_conn),
+                    );
+                    self.streams_with_pending_data.insert(stream_id);
+                } else {
+                    self.cancel_fetch(stream_id, Error::HttpRequestRejected.code(), conn)?;
+                    return Err(Error::InvalidStreamId);
+                }
+                Ok(())
+            }
+        }
+    }
+
+    pub(crate) fn webtransport_close_session(
+        &mut self,
+        conn: &mut Connection,
+        session_id: StreamId,
+        error: u32,
+        message: &str,
+    ) -> Res<()> {
+        qtrace!("Clos WebTransport session {:?}", session_id);
+        let send_stream = self
+            .send_streams
+            .get_mut(&session_id)
+            .ok_or(Error::InvalidStreamId)?;
+        if send_stream.stream_type() != Http3StreamType::ExtendedConnect {
+            return Err(Error::InvalidStreamId);
+        }
+
+        send_stream.close_with_message(conn, error, message)?;
+        if send_stream.done() {
+            self.remove_send_stream(session_id, conn);
+        } else if send_stream.has_data_to_send() {
+            self.streams_with_pending_data.insert(session_id);
+        }
+        Ok(())
+    }
+
+    pub fn webtransport_create_stream_local(
+        &mut self,
+        conn: &mut Connection,
+        session_id: StreamId,
+        stream_type: StreamType,
+        send_events: Box<dyn SendStreamEvents>,
+        recv_events: Box<dyn RecvStreamEvents>,
+    ) -> Res<StreamId> {
+        qtrace!(
+            "Create new WebTransport stream session={} type={:?}",
+            session_id,
+            stream_type
+        );
+
+        let wt = self
+            .recv_streams
+            .get(&session_id)
+            .ok_or(Error::InvalidStreamId)?
+            .webtransport()
+            .ok_or(Error::InvalidStreamId)?;
+        if !wt.borrow().is_active() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        let stream_id = conn
+            .stream_create(stream_type)
+            .map_err(|e| Error::map_stream_create_errors(&e))?;
+        // Set outgoing WebTransport streams to be fair (share bandwidth)
+        // This really can't fail, panics if it does
+        conn.stream_fairness(stream_id, true).unwrap();
+
+        self.webtransport_create_stream_internal(
+            wt,
+            stream_id,
+            session_id,
+            send_events,
+            recv_events,
+            true,
+        );
+        Ok(stream_id)
+    }
+
+    pub fn webtransport_create_stream_remote(
+        &mut self,
+        session_id: StreamId,
+        stream_id: StreamId,
+        send_events: Box<dyn SendStreamEvents>,
+        recv_events: Box<dyn RecvStreamEvents>,
+    ) -> Res<()> {
+        qtrace!(
+            "Create new WebTransport stream session={} stream_id={}",
+            session_id,
+            stream_id
+        );
+
+        let wt = self
+            .recv_streams
+            .get(&session_id)
+            .ok_or(Error::InvalidStreamId)?
+            .webtransport()
+            .ok_or(Error::InvalidStreamId)?;
+
+        self.webtransport_create_stream_internal(
+            wt,
+            stream_id,
+            session_id,
+            send_events,
+            recv_events,
+            false,
+        );
+        Ok(())
+    }
+
+    fn webtransport_create_stream_internal(
+        &mut self,
+        webtransport_session: Rc<RefCell<WebTransportSession>>,
+        stream_id: StreamId,
+        session_id: StreamId,
+        send_events: Box<dyn SendStreamEvents>,
+        recv_events: Box<dyn RecvStreamEvents>,
+        local: bool,
+    ) {
+        // TODO conn.stream_keep_alive(stream_id, true)?;
+        webtransport_session.borrow_mut().add_stream(stream_id);
+        if stream_id.stream_type() == StreamType::UniDi {
+            if local {
+                self.send_streams.insert(
+                    stream_id,
+                    Box::new(WebTransportSendStream::new(
+                        stream_id,
+                        session_id,
+                        send_events,
+                        webtransport_session,
+                        true,
+                    )),
+                );
+            } else {
+                self.recv_streams.insert(
+                    stream_id,
+                    Box::new(WebTransportRecvStream::new(
+                        stream_id,
+                        session_id,
+                        recv_events,
+                        webtransport_session,
+                    )),
+                );
+            }
+        } else {
+            self.add_streams(
+                stream_id,
+                Box::new(WebTransportSendStream::new(
+                    stream_id,
+                    session_id,
+                    send_events,
+                    webtransport_session.clone(),
+                    local,
+                )),
+                Box::new(WebTransportRecvStream::new(
+                    stream_id,
+                    session_id,
+                    recv_events,
+                    webtransport_session,
+                )),
+            );
+        }
+    }
+
+    pub fn webtransport_send_datagram(
+        &mut self,
+        session_id: StreamId,
+        conn: &mut Connection,
+        buf: &[u8],
+        id: impl Into<DatagramTracking>,
+    ) -> Res<()> {
+        self.recv_streams
+            .get_mut(&session_id)
+            .ok_or(Error::InvalidStreamId)?
+            .webtransport()
+            .ok_or(Error::InvalidStreamId)?
+            .borrow_mut()
+            .send_datagram(conn, buf, id)
+    }
+
+    /// If the control stream has received frames `MaxPushId`, `Goaway`, `PriorityUpdateRequest` or
+    /// `PriorityUpdateRequestPush` which handling is specific to the client and server, we must
+    /// give them to the specific client/server handler.
+    fn handle_control_frame(&mut self, f: HFrame) -> Res<Option<HFrame>> {
+        qinfo!([self], "Handle a control frame {:?}", f);
+        if !matches!(f, HFrame::Settings { .. })
+            && !matches!(
+                self.settings_state,
+                Http3RemoteSettingsState::Received { .. }
+            )
+        {
+            return Err(Error::HttpMissingSettings);
+        }
+        match f {
+            HFrame::Settings { settings } => {
+                self.handle_settings(settings)?;
+                Ok(None)
+            }
+            HFrame::Goaway { .. }
+            | HFrame::MaxPushId { .. }
+            | HFrame::CancelPush { .. }
+            | HFrame::PriorityUpdateRequest { .. }
+            | HFrame::PriorityUpdatePush { .. } => Ok(Some(f)),
+            _ => Err(Error::HttpFrameUnexpected),
+        }
+    }
+
+    fn set_qpack_settings(&mut self, settings: &HSettings) -> Res<()> {
+        let mut qpe = self.qpack_encoder.borrow_mut();
+        qpe.set_max_capacity(settings.get(HSettingType::MaxTableCapacity))?;
+        qpe.set_max_blocked_streams(settings.get(HSettingType::BlockedStreams))?;
+        Ok(())
+    }
+
+    fn handle_settings(&mut self, new_settings: HSettings) -> Res<()> {
+        qinfo!([self], "Handle SETTINGS frame.");
+        match &self.settings_state {
+            Http3RemoteSettingsState::NotReceived => {
+                self.set_qpack_settings(&new_settings)?;
+                self.webtransport.handle_settings(&new_settings);
+                self.settings_state = Http3RemoteSettingsState::Received(new_settings);
+                Ok(())
+            }
+            Http3RemoteSettingsState::ZeroRtt(settings) => {
+                self.webtransport.handle_settings(&new_settings);
+                let mut qpack_changed = false;
+                for st in &[
+                    HSettingType::MaxHeaderListSize,
+                    HSettingType::MaxTableCapacity,
+                    HSettingType::BlockedStreams,
+                ] {
+                    let zero_rtt_value = settings.get(*st);
+                    let new_value = new_settings.get(*st);
+                    if zero_rtt_value == new_value {
+                        continue;
+                    }
+                    if zero_rtt_value > new_value {
+                        qerror!(
+                            [self],
+                            "The new({}) and the old value({}) of setting {:?} do not match",
+                            new_value,
+                            zero_rtt_value,
+                            st
+                        );
+                        return Err(Error::HttpSettings);
+                    }
+
+                    match st {
+                        HSettingType::MaxTableCapacity => {
+                            if zero_rtt_value != 0 {
+                                return Err(Error::QpackError(neqo_qpack::Error::DecoderStream));
+                            }
+                            qpack_changed = true;
+                        }
+                        HSettingType::BlockedStreams => qpack_changed = true,
+                        HSettingType::MaxHeaderListSize
+                        | HSettingType::EnableWebTransport
+                        | HSettingType::EnableH3Datagram => (),
+                    }
+                }
+                if qpack_changed {
+                    qdebug!([self], "Settings after zero rtt differ.");
+                    self.set_qpack_settings(&(new_settings))?;
+                }
+                self.settings_state = Http3RemoteSettingsState::Received(new_settings);
+                Ok(())
+            }
+            Http3RemoteSettingsState::Received { .. } => Err(Error::HttpFrameUnexpected),
+        }
+    }
+
+    /// Return the current state on `Http3Connection`.
+    pub fn state(&self) -> Http3State {
+        self.state.clone()
+    }
+
+    /// Adds a new send and receive stream.
+    pub fn add_streams(
+        &mut self,
+        stream_id: StreamId,
+        send_stream: Box<dyn SendStream>,
+        recv_stream: Box<dyn RecvStream>,
+    ) {
+        if send_stream.has_data_to_send() {
+            self.streams_with_pending_data.insert(stream_id);
+        }
+        self.send_streams.insert(stream_id, send_stream);
+        self.recv_streams.insert(stream_id, recv_stream);
+    }
+
+    /// Add a new recv stream. This is used for push streams.
+    pub fn add_recv_stream(&mut self, stream_id: StreamId, recv_stream: Box<dyn RecvStream>) {
+        self.recv_streams.insert(stream_id, recv_stream);
+    }
+
+    pub fn queue_control_frame(&mut self, frame: &HFrame) {
+        self.control_stream_local.queue_frame(frame);
+    }
+
+    pub fn queue_update_priority(&mut self, stream_id: StreamId, priority: Priority) -> Res<bool> {
+        let stream = self
+            .recv_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .http_stream()
+            .ok_or(Error::InvalidStreamId)?;
+
+        if stream.maybe_update_priority(priority) {
+            self.control_stream_local.queue_update_priority(stream_id);
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+
+    fn recv_stream_is_critical(&self, stream_id: StreamId) -> bool {
+        if let Some(r) = self.recv_streams.get(&stream_id) {
+            matches!(
+                r.stream_type(),
+                Http3StreamType::Control | Http3StreamType::Encoder | Http3StreamType::Decoder
+            )
+        } else {
+            false
+        }
+    }
+
+    fn send_stream_is_critical(&self, stream_id: StreamId) -> bool {
+        self.qpack_encoder
+            .borrow()
+            .local_stream_id()
+            .iter()
+            .chain(self.qpack_decoder.borrow().local_stream_id().iter())
+            .chain(self.control_stream_local.stream_id().iter())
+            .any(|id| stream_id == *id)
+    }
+
+    fn close_send(&mut self, stream_id: StreamId, close_type: CloseType, conn: &mut Connection) {
+        if let Some(mut s) = self.remove_send_stream(stream_id, conn) {
+            s.handle_stop_sending(close_type);
+        }
+    }
+
+    fn close_recv(
+        &mut self,
+        stream_id: StreamId,
+        close_type: CloseType,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        if let Some(mut s) = self.remove_recv_stream(stream_id, conn) {
+            s.reset(close_type)?;
+        }
+        Ok(())
+    }
+
+    fn remove_extended_connect(
+        &mut self,
+        wt: &Rc<RefCell<WebTransportSession>>,
+        conn: &mut Connection,
+    ) {
+        let (recv, send) = wt.borrow_mut().take_sub_streams();
+
+        for id in recv {
+            qtrace!("Remove the extended connect sub receiver stream {}", id);
+            // Use CloseType::ResetRemote so that an event will be sent. CloseType::LocalError would
+            // have the same effect.
+            if let Some(mut s) = self.recv_streams.remove(&id) {
+                mem::drop(s.reset(CloseType::ResetRemote(Error::HttpRequestCancelled.code())));
+            }
+            mem::drop(conn.stream_stop_sending(id, Error::HttpRequestCancelled.code()));
+        }
+        for id in send {
+            qtrace!("Remove the extended connect sub send stream {}", id);
+            if let Some(mut s) = self.send_streams.remove(&id) {
+                s.handle_stop_sending(CloseType::ResetRemote(Error::HttpRequestCancelled.code()));
+            }
+            mem::drop(conn.stream_reset_send(id, Error::HttpRequestCancelled.code()));
+        }
+    }
+
+    fn remove_recv_stream(
+        &mut self,
+        stream_id: StreamId,
+        conn: &mut Connection,
+    ) -> Option<Box<dyn RecvStream>> {
+        let stream = self.recv_streams.remove(&stream_id);
+        if let Some(ref s) = stream {
+            if s.stream_type() == Http3StreamType::ExtendedConnect {
+                self.send_streams.remove(&stream_id).unwrap();
+                if let Some(wt) = s.webtransport() {
+                    self.remove_extended_connect(&wt, conn);
+                }
+            }
+        }
+        stream
+    }
+
+    fn remove_send_stream(
+        &mut self,
+        stream_id: StreamId,
+        conn: &mut Connection,
+    ) -> Option<Box<dyn SendStream>> {
+        let stream = self.send_streams.remove(&stream_id);
+        if let Some(ref s) = stream {
+            if s.stream_type() == Http3StreamType::ExtendedConnect {
+                if let Some(wt) = self.recv_streams.remove(&stream_id).unwrap().webtransport() {
+                    self.remove_extended_connect(&wt, conn);
+                }
+            }
+        }
+        stream
+    }
+
+    pub fn webtransport_enabled(&self) -> bool {
+        self.webtransport.enabled()
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/connection_client.rs b/third_party/rust/neqo-http3/src/connection_client.rs
new file mode 100644
index 0000000000..5cc0541c0c
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/connection_client.rs
@@ -0,0 +1,7296 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{
+    cell::RefCell,
+    convert::TryFrom,
+    fmt::{Debug, Display},
+    mem,
+    net::SocketAddr,
+    rc::Rc,
+    time::Instant,
+};
+
+use neqo_common::{
+    event::Provider as EventProvider, hex, hex_with_len, qdebug, qinfo, qlog::NeqoQlog, qtrace,
+    Datagram, Decoder, Encoder, Header, MessageType, Role,
+};
+use neqo_crypto::{agent::CertificateInfo, AuthenticationStatus, ResumptionToken, SecretAgentInfo};
+use neqo_qpack::Stats as QpackStats;
+use neqo_transport::{
+    streams::SendOrder, AppError, Connection, ConnectionEvent, ConnectionId, ConnectionIdGenerator,
+    DatagramTracking, Output, RecvStreamStats, SendStreamStats, Stats as TransportStats, StreamId,
+    StreamType, Version, ZeroRttState,
+};
+
+use crate::{
+    client_events::{Http3ClientEvent, Http3ClientEvents},
+    connection::{Http3Connection, Http3State, RequestDescription},
+    frames::HFrame,
+    push_controller::{PushController, RecvPushEvents},
+    recv_message::{RecvMessage, RecvMessageInfo},
+    request_target::AsRequestTarget,
+    settings::HSettings,
+    Error, Http3Parameters, Http3StreamType, NewStreamType, Priority, PriorityHandler,
+    ReceiveOutput, Res,
+};
+
+// This is used for filtering send_streams and recv_Streams with a stream_ids greater than or equal
+// a given id. Only the same type (bidirectional or unidirectionsl) streams are filtered.
+fn id_gte<U>(base: StreamId) -> impl FnMut((&StreamId, &U)) -> Option<StreamId> + 'static
+where
+    U: ?Sized,
+{
+    move |(id, _)| {
+        if *id >= base && !(id.is_bidi() ^ base.is_bidi()) {
+            Some(*id)
+        } else {
+            None
+        }
+    }
+}
+
+fn alpn_from_quic_version(version: Version) -> &'static str {
+    match version {
+        Version::Version2 | Version::Version1 => "h3",
+        Version::Draft29 => "h3-29",
+        Version::Draft30 => "h3-30",
+        Version::Draft31 => "h3-31",
+        Version::Draft32 => "h3-32",
+    }
+}
+
+/// # The HTTP/3 client API
+///
+/// This module implements the HTTP/3 client API. The main implementation of the protocol is in
+/// [connection.rs](https://github.com/mozilla/neqo/blob/main/neqo-http3/src/connection.rs) which
+/// implements common behavior for the client-side and the server-side. `Http3Client` structure
+/// implements the public API and set of functions that differ between the client and the server.
+
+/// The API is used for:
+/// - create and close an endpoint:
+///   - [`Http3Client::new`]
+///   - [`Http3Client::new_with_conn`]
+///   - [`Http3Client::close`]
+/// - configuring an endpoint:
+///   - [`Http3Client::authenticated`]
+///   - [`Http3Client::enable_ech`]
+///   - [`Http3Client::enable_resumption`]
+///   - [`Http3Client::initiate_key_update`]
+///   - [`Http3Client::set_qlog`]
+/// - retrieving information about a connection:
+/// - [`Http3Client::peer_certificate`]
+///   - [`Http3Client::qpack_decoder_stats`]
+///   - [`Http3Client::qpack_encoder_stats`]
+///   - [`Http3Client::transport_stats`]
+///   - [`Http3Client::state`]
+///   - [`Http3Client::take_resumption_token`]
+///   - [`Http3Client::tls_info`]
+/// - driving HTTP/3 session:
+///   - [`Http3Client::process_output`]
+///   - [`Http3Client::process_input`]
+///   - [`Http3Client::process`]
+/// - create requests, send/receive data, and cancel requests:
+///   - [`Http3Client::fetch`]
+///   - [`Http3Client::send_data`]
+///   - [`Http3Client::read_data`]
+///   - [`Http3Client::stream_close_send`]
+///   - [`Http3Client::cancel_fetch`]
+///   - [`Http3Client::stream_reset_send`]
+///   - [`Http3Client::stream_stop_sending`]
+///   - [`Http3Client::set_stream_max_data`]
+/// - priority feature:
+///   - [`Http3Client::priority_update`]
+/// - `WebTransport` feature:
+///   - [`Http3Client::webtransport_create_session`]
+///   - [`Http3Client::webtransport_close_session`]
+///   - [`Http3Client::webtransport_create_stream`]
+///   - [`Http3Client::webtransport_enabled`]
+///
+/// ## Examples
+///
+/// ### Fetching a resource
+///
+/// ```ignore
+/// let mut client = Http3Client::new(...);
+///
+/// // Perform a handshake
+/// ...
+///
+/// let req = client
+///     .fetch(
+///         Instant::now(),
+///         "GET",
+///         &("https", "something.com", "/"),
+///         &[Header::new("example1", "value1"), Header::new("example1", "value2")],
+///         Priority::default(),
+///     )
+///     .unwrap();
+///
+/// client.stream_close_send(req).unwrap();
+///
+/// loop {
+///     // exchange packets
+///     ...
+///
+///     while let Some(event) = client.next_event() {
+///         match event {
+///             Http3ClientEvent::HeaderReady { stream_id, headers, interim, fin } => {
+///                 println!("New response headers received for stream {:?} [fin={?}, interim={:?}]: {:?}",
+///                     stream_id,
+///                     fin,
+///                     interim,
+///                     headers,
+///                 );
+///             }
+///             Http3ClientEvent::DataReadable { stream_id } => {
+///                 println!("New data available on stream {}", stream_id);
+///                let mut buf = [0; 100];
+///                let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+///                 println!("Read {:?} bytes from stream {:?} [fin={?}]",
+///                     amount,
+///                     stream_id,
+///                     fin,
+///                 );
+///             }
+///             _ => {
+///                 println!("Unhandled event {:?}", event);
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// ### Creating a `WebTransport` session
+///
+/// ```ignore
+/// let mut client = Http3Client::new(...);
+///
+/// // Perform a handshake
+/// ...
+///
+/// // Create a session
+/// let wt_session_id = client
+///     .webtransport_create_session(now(), &("https", "something.com", "/"), &[])
+///     .unwrap();
+///
+/// loop {
+///     // exchange packets
+///     ...
+///
+///     while let Some(event) = client.next_event() {
+///         match event {
+///             Http3ClientEvent::WebTransport(WebTransportEvent::Session{
+///                 stream_id,
+///                 status,
+///                 ..
+///             }) => {
+///                 println!("The response from the server: WebTransport session ID {:?} status={:?}",
+///                     stream_id,
+///                     status,
+///                 );
+///             }
+///             _ => {
+///                 println!("Unhandled event {:?}", event);
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// ### `WebTransport`: create a stream, send and receive data on the stream
+///
+/// ```ignore
+/// const BUF_CLIENT: &[u8] = &[0; 10];
+/// // wt_session_id is the session ID of a newly created WebTransport session, see the example above.
+///
+/// // create a  stream
+/// let wt_stream_id = client
+///     .webtransport_create_stream(wt_session_id, StreamType::BiDi)
+///     .unwrap();
+///
+/// // send data
+/// let data_sent = client.send_data(wt_stream_id, BUF_CLIENT).unwrap();
+/// assert_eq!(data_sent, BUF_CLIENT.len());
+///
+/// // close stream for sending
+/// client.stream_close_send(wt_stream_id).unwrap();
+///
+/// // wait for data from the server
+/// loop {
+///     // exchange packets
+///     ...
+///
+///     while let Some(event) = client.next_event() {
+///         match event {
+///             Http3ClientEvent::DataReadable{ stream_id } => {
+///                 println!("Data receivedd form the server on WebTransport stream ID {:?}",
+///                     stream_id,
+///                 );
+///                 let mut buf = [0; 100];
+///                 let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+///                 println!("Read {:?} bytes from stream {:?} [fin={?}]",
+///                     amount,
+///                     stream_id,
+///                     fin,
+///                 );
+///             }
+///             _ => {
+///                 println!("Unhandled event {:?}", event);
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// ### `WebTransport`: receive a new stream form the server
+///
+/// ```ignore
+/// // wt_session_id is the session ID of a newly created WebTransport session, see the example above.
+///
+/// // wait for a new stream from the server
+/// loop {
+///     // exchange packets
+///     ...
+///
+///     while let Some(event) = client.next_event() {
+///         match event {
+///             Http3ClientEvent::WebTransport(WebTransportEvent::NewStream {
+///                 stream_id,
+///                 session_id,
+///             }) => {
+///                 println!("New stream received on session{:?}, stream id={:?} stream type={:?}",
+///                     sesson_id.stream_id(),
+///                     stream_id.stream_id(),
+///                     stream_id.stream_type()
+///                 );
+///             }
+///             Http3ClientEvent::DataReadable{ stream_id } => {
+///                 println!("Data receivedd form the server on WebTransport stream ID {:?}",
+///                     stream_id,
+///                 );
+///                 let mut buf = [0; 100];
+///                 let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+///                 println!("Read {:?} bytes from stream {:?} [fin={:?}]",
+///                     amount,
+///                     stream_id,
+///                     fin,
+///                 );
+///             }
+///             _ => {
+///                 println!("Unhandled event {:?}", event);
+///             }
+///         }
+///     }
+/// }
+/// ```
+pub struct Http3Client {
+    conn: Connection,
+    base_handler: Http3Connection,
+    events: Http3ClientEvents,
+    push_handler: Rc<RefCell<PushController>>,
+}
+
+impl Display for Http3Client {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Http3 client")
+    }
+}
+
+impl Http3Client {
+    /// # Errors
+    ///
+    /// Making a `neqo-transport::connection` may produce an error. This can only be a crypto error
+    /// if the crypto context can't be created or configured.
+    pub fn new(
+        server_name: impl Into<String>,
+        cid_manager: Rc<RefCell<dyn ConnectionIdGenerator>>,
+        local_addr: SocketAddr,
+        remote_addr: SocketAddr,
+        http3_parameters: Http3Parameters,
+        now: Instant,
+    ) -> Res<Self> {
+        Ok(Self::new_with_conn(
+            Connection::new_client(
+                server_name,
+                &[alpn_from_quic_version(
+                    http3_parameters
+                        .get_connection_parameters()
+                        .get_versions()
+                        .initial(),
+                )],
+                cid_manager,
+                local_addr,
+                remote_addr,
+                http3_parameters.get_connection_parameters().clone(),
+                now,
+            )?,
+            http3_parameters,
+        ))
+    }
+
+    /// This is a similar function to `new`. In this case, `neqo-transport::connection` has been
+    /// already created.
+    ///
+    /// It is recommended to use `new` instead.
+    #[must_use]
+    pub fn new_with_conn(c: Connection, http3_parameters: Http3Parameters) -> Self {
+        let events = Http3ClientEvents::default();
+        let webtransport = http3_parameters.get_webtransport();
+        let push_streams = http3_parameters.get_max_concurrent_push_streams();
+        let mut base_handler = Http3Connection::new(http3_parameters, Role::Client);
+        if webtransport {
+            base_handler.set_features_listener(events.clone());
+        }
+        Self {
+            conn: c,
+            events: events.clone(),
+            push_handler: Rc::new(RefCell::new(PushController::new(push_streams, events))),
+            base_handler,
+        }
+    }
+
+    #[must_use]
+    pub fn role(&self) -> Role {
+        self.conn.role()
+    }
+
+    /// The function returns the current state of the connection.
+    #[must_use]
+    pub fn state(&self) -> Http3State {
+        self.base_handler.state()
+    }
+
+    #[must_use]
+    pub fn tls_info(&self) -> Option<&SecretAgentInfo> {
+        self.conn.tls_info()
+    }
+
+    /// Get the peer's certificate.
+    #[must_use]
+    pub fn peer_certificate(&self) -> Option<CertificateInfo> {
+        self.conn.peer_certificate()
+    }
+
+    /// This called when peer certificates have been verified.
+    ///
+    /// `Http3ClientEvent::AuthenticationNeeded` event is emitted when peer’s certificates are
+    /// available and need to be verified. When the verification is completed this function is
+    /// called. To inform HTTP/3 session of the verification results.
+    pub fn authenticated(&mut self, status: AuthenticationStatus, now: Instant) {
+        self.conn.authenticated(status, now);
+    }
+
+    pub fn set_qlog(&mut self, qlog: NeqoQlog) {
+        self.conn.set_qlog(qlog);
+    }
+
+    /// Enable encrypted client hello (ECH).
+    ///
+    /// # Errors
+    ///
+    /// Fails when the configuration provided is bad.
+    pub fn enable_ech(&mut self, ech_config_list: impl AsRef<[u8]>) -> Res<()> {
+        self.conn.client_enable_ech(ech_config_list)?;
+        Ok(())
+    }
+
+    /// Get the connection id, which is useful for disambiguating connections to
+    /// the same origin.
+    ///
+    /// # Panics
+    ///
+    /// Never, because clients always have this field.
+    #[must_use]
+    pub fn connection_id(&self) -> &ConnectionId {
+        self.conn.odcid().expect("Client always has odcid")
+    }
+
+    fn encode_resumption_token(&self, token: &ResumptionToken) -> Option<ResumptionToken> {
+        self.base_handler.get_settings().map(|settings| {
+            let mut enc = Encoder::default();
+            settings.encode_frame_contents(&mut enc);
+            enc.encode(token.as_ref());
+            ResumptionToken::new(enc.into(), token.expiration_time())
+        })
+    }
+
+    /// The correct way to obtain a resumption token is to wait for the
+    /// `Http3ClientEvent::ResumptionToken` event. To emit the event we are waiting for a
+    /// resumtion token and a `NEW_TOKEN` frame to arrive. Some servers don't send `NEW_TOKEN`
+    /// frames and in this case, we wait for 3xPTO before emitting an event. This is especially a
+    /// problem for short-lived connections, where the connection is closed before any events are
+    /// released. This function retrieves the token, without waiting for a `NEW_TOKEN` frame to
+    /// arrive.
+    ///
+    /// In addition to the token, HTTP/3 settings are encoded into the token before giving it to
+    /// the application(`encode_resumption_token`). When the resumption token is supplied to a new
+    /// connection the HTTP/3 setting will be decoded and used until the setting are received from
+    /// the server.
+    pub fn take_resumption_token(&mut self, now: Instant) -> Option<ResumptionToken> {
+        self.conn
+            .take_resumption_token(now)
+            .and_then(|t| self.encode_resumption_token(&t))
+    }
+
+    /// This may be call if an application has a resumption token. This must be called before
+    /// connection starts.
+    ///
+    /// The resumption token also contains encoded HTTP/3 settings. The settings will be decoded
+    /// and used until the setting are received from the server.
+    ///
+    /// # Errors
+    ///
+    /// An error is return if token cannot be decoded or a connection is is a wrong state.
+    ///
+    /// # Panics
+    ///
+    /// On closing if the base handler can't handle it (debug only).
+    pub fn enable_resumption(&mut self, now: Instant, token: impl AsRef<[u8]>) -> Res<()> {
+        if self.base_handler.state != Http3State::Initializing {
+            return Err(Error::InvalidState);
+        }
+        let mut dec = Decoder::from(token.as_ref());
+        let Some(settings_slice) = dec.decode_vvec() else {
+            return Err(Error::InvalidResumptionToken);
+        };
+        qtrace!([self], "  settings {}", hex_with_len(settings_slice));
+        let mut dec_settings = Decoder::from(settings_slice);
+        let mut settings = HSettings::default();
+        Error::map_error(
+            settings.decode_frame_contents(&mut dec_settings),
+            Error::InvalidResumptionToken,
+        )?;
+        let tok = dec.decode_remainder();
+        qtrace!([self], "  Transport token {}", hex(tok));
+        self.conn.enable_resumption(now, tok)?;
+        if self.conn.state().closed() {
+            let state = self.conn.state().clone();
+            let res = self
+                .base_handler
+                .handle_state_change(&mut self.conn, &state);
+            debug_assert_eq!(Ok(true), res);
+            return Err(Error::FatalError);
+        }
+        if self.conn.zero_rtt_state() == ZeroRttState::Sending {
+            self.base_handler
+                .set_0rtt_settings(&mut self.conn, settings)?;
+            self.events
+                .connection_state_change(self.base_handler.state());
+            self.push_handler
+                .borrow_mut()
+                .maybe_send_max_push_id_frame(&mut self.base_handler);
+        }
+        Ok(())
+    }
+
+    /// This is call to close a connection.
+    pub fn close<S>(&mut self, now: Instant, error: AppError, msg: S)
+    where
+        S: AsRef<str> + Display,
+    {
+        qinfo!([self], "Close the connection error={} msg={}.", error, msg);
+        if !matches!(
+            self.base_handler.state,
+            Http3State::Closing(_) | Http3State::Closed(_)
+        ) {
+            self.push_handler.borrow_mut().clear();
+            self.conn.close(now, error, msg);
+            self.base_handler.close(error);
+            self.events
+                .connection_state_change(self.base_handler.state());
+        }
+    }
+
+    /// Attempt to force a key update.
+    ///
+    /// # Errors
+    ///
+    /// If the connection isn't confirmed, or there is an outstanding key update, this
+    /// returns `Err(Error::TransportError(neqo_transport::Error::KeyUpdateBlocked))`.
+    pub fn initiate_key_update(&mut self) -> Res<()> {
+        self.conn.initiate_key_update()?;
+        Ok(())
+    }
+
+    // API: Request/response
+
+    /// The function fetches a resource using `method`, `target` and `headers`. A response body
+    /// may be added by calling `send_data`. `stream_close_send` must be sent to finish the request
+    /// even if request data are not sent.
+    ///
+    /// # Errors
+    ///
+    /// If a new stream cannot be created an error will be return.
+    ///
+    /// # Panics
+    ///
+    /// `SendMessage` implements `http_stream` so it will not panic.
+    pub fn fetch<'x, 't: 'x, T>(
+        &mut self,
+        now: Instant,
+        method: &'t str,
+        target: &'t T,
+        headers: &'t [Header],
+        priority: Priority,
+    ) -> Res<StreamId>
+    where
+        T: AsRequestTarget<'x> + ?Sized + Debug,
+    {
+        let output = self.base_handler.fetch(
+            &mut self.conn,
+            Box::new(self.events.clone()),
+            Box::new(self.events.clone()),
+            Some(Rc::clone(&self.push_handler)),
+            &RequestDescription {
+                method,
+                connect_type: None,
+                target,
+                headers,
+                priority,
+            },
+        );
+        if let Err(e) = &output {
+            if e.connection_error() {
+                self.close(now, e.code(), "");
+            }
+        }
+        output
+    }
+
+    /// Send an [`PRIORITY_UPDATE`-frame][1] on next `Http3Client::process_output()` call.
+    /// Returns if the priority got changed.
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist
+    ///
+    /// [1]: https://datatracker.ietf.org/doc/html/draft-kazuho-httpbis-priority-04#section-5.2
+    pub fn priority_update(&mut self, stream_id: StreamId, priority: Priority) -> Res<bool> {
+        self.base_handler.queue_update_priority(stream_id, priority)
+    }
+
+    /// An application may cancel a stream(request).
+    /// Both sides, the receiviing and sending side, sending and receiving side, will be closed.
+    ///
+    /// # Errors
+    ///
+    /// An error will be return if a stream does not exist.
+    pub fn cancel_fetch(&mut self, stream_id: StreamId, error: AppError) -> Res<()> {
+        qinfo!([self], "reset_stream {} error={}.", stream_id, error);
+        self.base_handler
+            .cancel_fetch(stream_id, error, &mut self.conn)
+    }
+
+    /// This is call when application is done sending a request.
+    ///
+    /// # Errors
+    ///
+    /// An error will be return if stream does not exist.
+    pub fn stream_close_send(&mut self, stream_id: StreamId) -> Res<()> {
+        qinfo!([self], "Close sending side stream={}.", stream_id);
+        self.base_handler
+            .stream_close_send(&mut self.conn, stream_id)
+    }
+
+    /// # Errors
+    ///
+    /// An error will be return if a stream does not exist.
+    pub fn stream_reset_send(&mut self, stream_id: StreamId, error: AppError) -> Res<()> {
+        qinfo!([self], "stream_reset_send {} error={}.", stream_id, error);
+        self.base_handler
+            .stream_reset_send(&mut self.conn, stream_id, error)
+    }
+
+    /// # Errors
+    ///
+    /// An error will be return if a stream does not exist.
+    pub fn stream_stop_sending(&mut self, stream_id: StreamId, error: AppError) -> Res<()> {
+        qinfo!([self], "stream_stop_sending {} error={}.", stream_id, error);
+        self.base_handler
+            .stream_stop_sending(&mut self.conn, stream_id, error)
+    }
+
+    /// This function is used for regular HTTP requests and `WebTransport` streams.
+    /// In the case of regular HTTP requests, the request body is supplied using this function, and
+    /// headers are supplied through the `fetch` function.
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist,
+    /// `AlreadyClosed` if the stream has already been closed.
+    /// `TransportStreamDoesNotExist` if the transport stream does not exist (this may happen if
+    /// `process_output` has not been called when needed, and HTTP3 layer has not picked up the
+    /// info that the stream has been closed.) `InvalidInput` if an empty buffer has been
+    /// supplied.
+    pub fn send_data(&mut self, stream_id: StreamId, buf: &[u8]) -> Res<usize> {
+        qinfo!(
+            [self],
+            "send_data from stream {} sending {} bytes.",
+            stream_id,
+            buf.len()
+        );
+        self.base_handler
+            .send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .send_data(&mut self.conn, buf)
+    }
+
+    /// Response data are read directly into a buffer supplied as a parameter of this function to
+    /// avoid copying data.
+    ///
+    /// # Errors
+    ///
+    /// It returns an error if a stream does not exist or an error happen while reading a stream,
+    /// e.g. early close, protocol error, etc.
+    pub fn read_data(
+        &mut self,
+        now: Instant,
+        stream_id: StreamId,
+        buf: &mut [u8],
+    ) -> Res<(usize, bool)> {
+        qinfo!([self], "read_data from stream {}.", stream_id);
+        let res = self.base_handler.read_data(&mut self.conn, stream_id, buf);
+        if let Err(e) = &res {
+            if e.connection_error() {
+                self.close(now, e.code(), "");
+            }
+        }
+        res
+    }
+
+    // API: Push streams
+
+    /// Cancel a push
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist.
+    pub fn cancel_push(&mut self, push_id: u64) -> Res<()> {
+        self.push_handler
+            .borrow_mut()
+            .cancel(push_id, &mut self.conn, &mut self.base_handler)
+    }
+
+    /// Push response data are read directly into a buffer supplied as a parameter of this function
+    /// to avoid copying data.
+    ///
+    /// # Errors
+    ///
+    /// It returns an error if a stream does not exist(`InvalidStreamId`) or an error has happened
+    /// while reading a stream, e.g. early close, protocol error, etc.
+    pub fn push_read_data(
+        &mut self,
+        now: Instant,
+        push_id: u64,
+        buf: &mut [u8],
+    ) -> Res<(usize, bool)> {
+        let stream_id = self
+            .push_handler
+            .borrow_mut()
+            .get_active_stream_id(push_id)
+            .ok_or(Error::InvalidStreamId)?;
+        self.conn.stream_keep_alive(stream_id, true)?;
+        self.read_data(now, stream_id, buf)
+    }
+
+    // API WebTransport
+    //
+    /// # Errors
+    ///
+    /// If `WebTransport` cannot be created, e.g. the `WebTransport` support is
+    /// not negotiated or the HTTP/3 connection is closed.
+    pub fn webtransport_create_session<'x, 't: 'x, T>(
+        &mut self,
+        now: Instant,
+        target: &'t T,
+        headers: &'t [Header],
+    ) -> Res<StreamId>
+    where
+        T: AsRequestTarget<'x> + ?Sized + Debug,
+    {
+        let output = self.base_handler.webtransport_create_session(
+            &mut self.conn,
+            Box::new(self.events.clone()),
+            target,
+            headers,
+        );
+
+        if let Err(e) = &output {
+            if e.connection_error() {
+                self.close(now, e.code(), "");
+            }
+        }
+        output
+    }
+
+    /// Close `WebTransport` cleanly
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist,
+    /// `TransportStreamDoesNotExist` if the transport stream does not exist (this may happen if
+    /// `process_output` has not been called when needed, and HTTP3 layer has not picked up the
+    /// info that the stream has been closed.) `InvalidInput` if an empty buffer has been
+    /// supplied.
+    pub fn webtransport_close_session(
+        &mut self,
+        session_id: StreamId,
+        error: u32,
+        message: &str,
+    ) -> Res<()> {
+        self.base_handler
+            .webtransport_close_session(&mut self.conn, session_id, error, message)
+    }
+
+    /// # Errors
+    ///
+    /// This may return an error if the particular session does not exist
+    /// or the connection is not in the active state.
+    pub fn webtransport_create_stream(
+        &mut self,
+        session_id: StreamId,
+        stream_type: StreamType,
+    ) -> Res<StreamId> {
+        self.base_handler.webtransport_create_stream_local(
+            &mut self.conn,
+            session_id,
+            stream_type,
+            Box::new(self.events.clone()),
+            Box::new(self.events.clone()),
+        )
+    }
+
+    /// Send `WebTransport` datagram.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    /// The function returns `TooMuchData` if the supply buffer is bigger than
+    /// the allowed remote datagram size.
+    pub fn webtransport_send_datagram(
+        &mut self,
+        session_id: StreamId,
+        buf: &[u8],
+        id: impl Into<DatagramTracking>,
+    ) -> Res<()> {
+        qtrace!("webtransport_send_datagram session:{:?}", session_id);
+        self.base_handler
+            .webtransport_send_datagram(session_id, &mut self.conn, buf, id)
+    }
+
+    /// Returns the current max size of a datagram that can fit into a packet.
+    /// The value will change over time depending on the encoded size of the
+    /// packet number, ack frames, etc.
+    ///
+    /// # Errors
+    ///
+    /// The function returns `NotAvailable` if datagrams are not enabled.
+    ///
+    /// # Panics
+    ///
+    /// This cannot panic. The max varint length is 8.
+    pub fn webtransport_max_datagram_size(&self, session_id: StreamId) -> Res<u64> {
+        Ok(self.conn.max_datagram_size()?
+            - u64::try_from(Encoder::varint_len(session_id.as_u64())).unwrap())
+    }
+
+    /// Sets the `SendOrder` for a given stream
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    ///
+    /// # Panics
+    ///
+    /// This cannot panic.
+    pub fn webtransport_set_sendorder(
+        &mut self,
+        stream_id: StreamId,
+        sendorder: Option<SendOrder>,
+    ) -> Res<()> {
+        Http3Connection::stream_set_sendorder(&mut self.conn, stream_id, sendorder)
+    }
+
+    /// Sets the `Fairness` for a given stream
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    ///
+    /// # Panics
+    ///
+    /// This cannot panic.
+    pub fn webtransport_set_fairness(&mut self, stream_id: StreamId, fairness: bool) -> Res<()> {
+        Http3Connection::stream_set_fairness(&mut self.conn, stream_id, fairness)
+    }
+
+    /// Returns the current `SendStreamStats` of a `WebTransportSendStream`.
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist.
+    pub fn webtransport_send_stream_stats(&mut self, stream_id: StreamId) -> Res<SendStreamStats> {
+        self.base_handler
+            .send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .stats(&mut self.conn)
+    }
+
+    /// Returns the current `RecvStreamStats` of a `WebTransportRecvStream`.
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist.
+    pub fn webtransport_recv_stream_stats(&mut self, stream_id: StreamId) -> Res<RecvStreamStats> {
+        self.base_handler
+            .recv_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .stats(&mut self.conn)
+    }
+
+    /// This function combines  `process_input` and `process_output` function.
+    pub fn process(&mut self, dgram: Option<&Datagram>, now: Instant) -> Output {
+        qtrace!([self], "Process.");
+        if let Some(d) = dgram {
+            self.process_input(d, now);
+        }
+        self.process_output(now)
+    }
+
+    /// The function should be called when there is a new UDP packet available. The function will
+    /// handle the packet payload.
+    ///
+    /// First, the payload will be handled by the QUIC layer. Afterward, `process_http3` will be
+    /// called to handle new [`ConnectionEvent`][1]s.
+    ///
+    /// After this function is called `process_output` should be called to check whether new
+    /// packets need to be sent or if a timer needs to be updated.
+    ///
+    /// [1]: ../neqo_transport/enum.ConnectionEvent.html
+    pub fn process_input(&mut self, dgram: &Datagram, now: Instant) {
+        qtrace!([self], "Process input.");
+        self.conn.process_input(dgram, now);
+        self.process_http3(now);
+    }
+
+    pub fn process_multiple_input<'a, I>(&mut self, dgrams: I, now: Instant)
+    where
+        I: IntoIterator<Item = &'a Datagram>,
+        I::IntoIter: ExactSizeIterator,
+    {
+        let dgrams = dgrams.into_iter();
+        qtrace!([self], "Process multiple datagrams, len={}", dgrams.len());
+        if dgrams.len() == 0 {
+            return;
+        }
+        self.conn.process_multiple_input(dgrams, now);
+        self.process_http3(now);
+    }
+
+    /// This should not be used because it gives access to functionalities that may disrupt the
+    /// proper functioning of the HTTP/3 session.
+    /// Only used by `neqo-interop`.
+    pub fn conn(&mut self) -> &mut Connection {
+        &mut self.conn
+    }
+
+    /// Process HTTP3 layer.
+    /// When `process_output`, `process_input`, or `process` is called we must call this function
+    /// as well. The functions calls `Http3Client::check_connection_events` to handle events from
+    /// the QUC layer and calls `Http3Connection::process_sending` to ensure that HTTP/3 layer
+    /// data, e.g. control frames, are sent.
+    fn process_http3(&mut self, now: Instant) {
+        qtrace!([self], "Process http3 internal.");
+        match self.base_handler.state() {
+            Http3State::ZeroRtt | Http3State::Connected | Http3State::GoingAway(..) => {
+                let res = self.check_connection_events();
+                if self.check_result(now, &res) {
+                    return;
+                }
+                self.push_handler
+                    .borrow_mut()
+                    .maybe_send_max_push_id_frame(&mut self.base_handler);
+                let res = self.base_handler.process_sending(&mut self.conn);
+                self.check_result(now, &res);
+            }
+            Http3State::Closed { .. } => {}
+            _ => {
+                let res = self.check_connection_events();
+                _ = self.check_result(now, &res);
+            }
+        }
+    }
+
+    /// The function should be called to check if there is a new UDP packet to be sent. It should
+    /// be called after a new packet is received and processed and after a timer expires (QUIC
+    /// needs timers to handle events like PTO detection and timers are not implemented by the neqo
+    /// library, but instead must be driven by the application).
+    ///
+    /// `process_output` can return:
+    /// - a [`Output::Datagram(Datagram)`][1]: data that should be sent as a UDP payload,
+    /// - a [`Output::Callback(Duration)`][1]: the duration of a  timer. `process_output` should be
+    ///   called at least after the time expires,
+    /// - [`Output::None`][1]: this is returned when `Nttp3Client` is done and can be destroyed.
+    ///
+    /// The application should call this function repeatedly until a timer value or None is
+    /// returned. After that, the application should call the function again if a new UDP packet is
+    /// received and processed or the timer value expires.
+    ///
+    /// The HTTP/3 neqo implementation drives the HTTP/3 and QUC layers, therefore this function
+    /// will call both layers:
+    ///  - First it calls HTTP/3 layer processing (`process_http3`) to make sure the layer writes
+    ///    data to QUIC layer or cancels streams if needed.
+    ///  - Then QUIC layer processing is called - [`Connection::process_output`][3]. This produces a
+    ///    packet or a timer value. It may also produce ned [`ConnectionEvent`][2]s, e.g. connection
+    ///    state-change event.
+    ///  - Therefore the HTTP/3 layer processing (`process_http3`) is called again.
+    ///
+    /// [1]: ../neqo_transport/enum.Output.html
+    /// [2]: ../neqo_transport/struct.ConnectionEvents.html
+    /// [3]: ../neqo_transport/struct.Connection.html#method.process_output
+    pub fn process_output(&mut self, now: Instant) -> Output {
+        qtrace!([self], "Process output.");
+
+        // Maybe send() stuff on http3-managed streams
+        self.process_http3(now);
+
+        let out = self.conn.process_output(now);
+
+        // Update H3 for any transport state changes and events
+        self.process_http3(now);
+
+        out
+    }
+
+    /// This function takes the provided result and check for an error.
+    /// An error results in closing the connection.
+    fn check_result<ERR>(&mut self, now: Instant, res: &Res<ERR>) -> bool {
+        match &res {
+            Err(Error::HttpGoaway) => {
+                qinfo!([self], "Connection error: goaway stream_id increased.");
+                self.close(
+                    now,
+                    Error::HttpGeneralProtocol.code(),
+                    "Connection error: goaway stream_id increased",
+                );
+                true
+            }
+            Err(e) => {
+                qinfo!([self], "Connection error: {}.", e);
+                self.close(now, e.code(), &format!("{e}"));
+                true
+            }
+            _ => false,
+        }
+    }
+
+    /// This function checks [`ConnectionEvent`][2]s emitted by the QUIC layer, e.g. connection
+    /// change state events, new incoming stream data is available, a stream is was reset, etc.
+    /// The HTTP/3 layer needs to handle these events. Most of the events are handled by
+    /// [`Http3Connection`][1] by calling appropriate functions, e.g. `handle_state_change`,
+    /// `handle_stream_reset`, etc. [`Http3Connection`][1] handle functionalities that are common
+    /// for the client and server side. Some of the functionalities are specific to the client and
+    /// they are handled by `Http3Client`. For example, [`ConnectionEvent::RecvStreamReadable`][3]
+    /// event is handled by `Http3Client::handle_stream_readable`. The  function calls
+    /// `Http3Connection::handle_stream_readable` and then hands the return value as appropriate
+    /// for the client-side.
+    ///
+    /// [1]: https://github.com/mozilla/neqo/blob/main/neqo-http3/src/connection.rs
+    /// [2]: ../neqo_transport/enum.ConnectionEvent.html
+    /// [3]: ../neqo_transport/enum.ConnectionEvent.html#variant.RecvStreamReadable
+    fn check_connection_events(&mut self) -> Res<()> {
+        qtrace!([self], "Check connection events.");
+        while let Some(e) = self.conn.next_event() {
+            qdebug!([self], "check_connection_events - event {:?}.", e);
+            match e {
+                ConnectionEvent::NewStream { stream_id } => {
+                    // During this event we only add a new stream to the Http3Connection stream
+                    // list, with NewStreamHeadReader stream handler.
+                    // This function will not read from the stream and try to decode the stream.
+                    // RecvStreamReadable  will be emitted after this event and reading, i.e.
+                    // decoding of a stream will happen during that event.
+                    self.base_handler.add_new_stream(stream_id);
+                }
+                ConnectionEvent::SendStreamWritable { stream_id } => {
+                    if let Some(s) = self.base_handler.send_streams.get_mut(&stream_id) {
+                        s.stream_writable();
+                    }
+                }
+                ConnectionEvent::RecvStreamReadable { stream_id } => {
+                    self.handle_stream_readable(stream_id)?;
+                }
+                ConnectionEvent::RecvStreamReset {
+                    stream_id,
+                    app_error,
+                } => self
+                    .base_handler
+                    .handle_stream_reset(stream_id, app_error, &mut self.conn)?,
+                ConnectionEvent::SendStreamStopSending {
+                    stream_id,
+                    app_error,
+                } => self.base_handler.handle_stream_stop_sending(
+                    stream_id,
+                    app_error,
+                    &mut self.conn,
+                )?,
+
+                ConnectionEvent::SendStreamCreatable { stream_type } => {
+                    self.events.new_requests_creatable(stream_type);
+                }
+                ConnectionEvent::AuthenticationNeeded => self.events.authentication_needed(),
+                ConnectionEvent::EchFallbackAuthenticationNeeded { public_name } => {
+                    self.events.ech_fallback_authentication_needed(public_name);
+                }
+                ConnectionEvent::StateChange(state) => {
+                    if self
+                        .base_handler
+                        .handle_state_change(&mut self.conn, &state)?
+                    {
+                        self.events
+                            .connection_state_change(self.base_handler.state());
+                    }
+                }
+                ConnectionEvent::ZeroRttRejected => {
+                    self.base_handler.handle_zero_rtt_rejected()?;
+                    self.events.zero_rtt_rejected();
+                    self.push_handler.borrow_mut().handle_zero_rtt_rejected();
+                }
+                ConnectionEvent::ResumptionToken(token) => {
+                    if let Some(t) = self.encode_resumption_token(&token) {
+                        self.events.resumption_token(t);
+                    }
+                }
+                ConnectionEvent::Datagram(dgram) => {
+                    self.base_handler.handle_datagram(&dgram);
+                }
+                ConnectionEvent::SendStreamComplete { .. }
+                | ConnectionEvent::OutgoingDatagramOutcome { .. }
+                | ConnectionEvent::IncomingDatagramDropped => {}
+            }
+        }
+        Ok(())
+    }
+
+    /// This function handled new data available on a stream. It calls
+    /// `Http3Client::handle_stream_readable` and handles its response. Reading streams are mostly
+    /// handled by [`Http3Connection`][1] because most part of it is common for the client and
+    /// server. The following actions need to be handled by the client-specific code:
+    ///  - `ReceiveOutput::NewStream(NewStreamType::Push(_))` - the server cannot receive a push
+    ///    stream,
+    ///  - `ReceiveOutput::NewStream(NewStreamType::Http)` - client cannot  receive a
+    ///    server-initiated HTTP request,
+    ///  - `ReceiveOutput::NewStream(NewStreamType::WebTransportStream(_))` - because
+    ///    `Http3ClientEvents`is needed and events handler is specific to the client.
+    ///  - `ReceiveOutput::ControlFrames(control_frames)` - some control frame handling differs
+    ///    between the  client and the server:
+    ///     - `HFrame::CancelPush` - only the client-side may receive it,
+    ///     - `HFrame::MaxPushId { .. }`, `HFrame::PriorityUpdateRequest { .. } ` and
+    ///       `HFrame::PriorityUpdatePush` can only be receive on the server side,
+    ///     - `HFrame::Goaway { stream_id }` needs specific handling by the client by the protocol
+    ///       specification.
+    ///
+    /// [1]: https://github.com/mozilla/neqo/blob/main/neqo-http3/src/connection.rs
+    fn handle_stream_readable(&mut self, stream_id: StreamId) -> Res<()> {
+        match self
+            .base_handler
+            .handle_stream_readable(&mut self.conn, stream_id)?
+        {
+            ReceiveOutput::NewStream(NewStreamType::Push(push_id)) => {
+                self.handle_new_push_stream(stream_id, push_id)
+            }
+            ReceiveOutput::NewStream(NewStreamType::Http) => Err(Error::HttpStreamCreation),
+            ReceiveOutput::NewStream(NewStreamType::WebTransportStream(session_id)) => {
+                self.base_handler.webtransport_create_stream_remote(
+                    StreamId::from(session_id),
+                    stream_id,
+                    Box::new(self.events.clone()),
+                    Box::new(self.events.clone()),
+                )?;
+                let res = self
+                    .base_handler
+                    .handle_stream_readable(&mut self.conn, stream_id)?;
+                debug_assert!(matches!(res, ReceiveOutput::NoOutput));
+                Ok(())
+            }
+            ReceiveOutput::ControlFrames(control_frames) => {
+                for f in control_frames {
+                    match f {
+                        HFrame::CancelPush { push_id } => self
+                            .push_handler
+                            .borrow_mut()
+                            .handle_cancel_push(push_id, &mut self.conn, &mut self.base_handler),
+                        HFrame::MaxPushId { .. }
+                        | HFrame::PriorityUpdateRequest { .. }
+                        | HFrame::PriorityUpdatePush { .. } => Err(Error::HttpFrameUnexpected),
+                        HFrame::Goaway { stream_id } => self.handle_goaway(stream_id),
+                        _ => {
+                            unreachable!(
+                                "we should only put MaxPushId, Goaway and PriorityUpdates into control_frames."
+                            );
+                        }
+                    }?;
+                }
+                Ok(())
+            }
+            _ => Ok(()),
+        }
+    }
+
+    fn handle_new_push_stream(&mut self, stream_id: StreamId, push_id: u64) -> Res<()> {
+        if !self.push_handler.borrow().can_receive_push() {
+            return Err(Error::HttpId);
+        }
+
+        // Add a new push stream to `PushController`. `add_new_push_stream` may return an error
+        // (this will be a connection error) or a bool.
+        // If false is returned that means that the stream should be reset because the push has
+        // been already canceled (CANCEL_PUSH frame or canceling push from the application).
+        if !self
+            .push_handler
+            .borrow_mut()
+            .add_new_push_stream(push_id, stream_id)?
+        {
+            // We are not interested in the result of stream_stop_sending, we are not interested
+            // in this stream.
+            mem::drop(
+                self.conn
+                    .stream_stop_sending(stream_id, Error::HttpRequestCancelled.code()),
+            );
+            return Ok(());
+        }
+
+        self.base_handler.add_recv_stream(
+            stream_id,
+            Box::new(RecvMessage::new(
+                &RecvMessageInfo {
+                    message_type: MessageType::Response,
+                    stream_type: Http3StreamType::Push,
+                    stream_id,
+                    header_frame_type_read: false,
+                },
+                Rc::clone(&self.base_handler.qpack_decoder),
+                Box::new(RecvPushEvents::new(push_id, Rc::clone(&self.push_handler))),
+                None,
+                // TODO: think about the right prority for the push streams.
+                PriorityHandler::new(true, Priority::default()),
+            )),
+        );
+        let res = self
+            .base_handler
+            .handle_stream_readable(&mut self.conn, stream_id)?;
+        debug_assert!(matches!(res, ReceiveOutput::NoOutput));
+        Ok(())
+    }
+
+    fn handle_goaway(&mut self, goaway_stream_id: StreamId) -> Res<()> {
+        qinfo!([self], "handle_goaway {}", goaway_stream_id);
+
+        if goaway_stream_id.is_uni() || goaway_stream_id.is_server_initiated() {
+            return Err(Error::HttpId);
+        }
+
+        match self.base_handler.state {
+            Http3State::Connected => {
+                self.base_handler.state = Http3State::GoingAway(goaway_stream_id);
+            }
+            Http3State::GoingAway(ref mut stream_id) => {
+                if goaway_stream_id > *stream_id {
+                    return Err(Error::HttpGoaway);
+                }
+                *stream_id = goaway_stream_id;
+            }
+            Http3State::Closing(..) | Http3State::Closed(..) => {}
+            _ => unreachable!("Should not receive Goaway frame in this state."),
+        }
+
+        // Issue reset events for streams >= goaway stream id
+        let send_ids: Vec<StreamId> = self
+            .base_handler
+            .send_streams
+            .iter()
+            .filter_map(id_gte(goaway_stream_id))
+            .collect();
+        for id in send_ids {
+            // We do not care about streams that are going to be closed.
+            mem::drop(self.base_handler.handle_stream_stop_sending(
+                id,
+                Error::HttpRequestRejected.code(),
+                &mut self.conn,
+            ));
+        }
+
+        let recv_ids: Vec<StreamId> = self
+            .base_handler
+            .recv_streams
+            .iter()
+            .filter_map(id_gte(goaway_stream_id))
+            .collect();
+        for id in recv_ids {
+            // We do not care about streams that are going to be closed.
+            mem::drop(self.base_handler.handle_stream_reset(
+                id,
+                Error::HttpRequestRejected.code(),
+                &mut self.conn,
+            ));
+        }
+
+        self.events.goaway_received();
+
+        Ok(())
+    }
+
+    /// Increases `max_stream_data` for a `stream_id`.
+    ///
+    /// # Errors
+    ///
+    /// Returns `InvalidStreamId` if a stream does not exist or the receiving
+    /// side is closed.
+    pub fn set_stream_max_data(&mut self, stream_id: StreamId, max_data: u64) -> Res<()> {
+        self.conn.set_stream_max_data(stream_id, max_data)?;
+        Ok(())
+    }
+
+    #[must_use]
+    pub fn qpack_decoder_stats(&self) -> QpackStats {
+        self.base_handler.qpack_decoder.borrow().stats()
+    }
+
+    #[must_use]
+    pub fn qpack_encoder_stats(&self) -> QpackStats {
+        self.base_handler.qpack_encoder.borrow().stats()
+    }
+
+    #[must_use]
+    pub fn transport_stats(&self) -> TransportStats {
+        self.conn.stats()
+    }
+
+    #[must_use]
+    pub fn webtransport_enabled(&self) -> bool {
+        self.base_handler.webtransport_enabled()
+    }
+}
+
+impl EventProvider for Http3Client {
+    type Event = Http3ClientEvent;
+
+    /// Return true if there are outstanding events.
+    fn has_events(&self) -> bool {
+        self.events.has_events()
+    }
+
+    /// Get events that indicate state changes on the connection. This method
+    /// correctly handles cases where handling one event can obsolete
+    /// previously-queued events, or cause new events to be generated.
+    fn next_event(&mut self) -> Option<Self::Event> {
+        self.events.next_event()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{convert::TryFrom, mem, time::Duration};
+
+    use neqo_common::{event::Provider, qtrace, Datagram, Decoder, Encoder};
+    use neqo_crypto::{AllowZeroRtt, AntiReplay, ResumptionToken};
+    use neqo_qpack::{encoder::QPackEncoder, QpackSettings};
+    use neqo_transport::{
+        ConnectionError, ConnectionEvent, ConnectionParameters, Output, State, StreamId,
+        StreamType, Version, RECV_BUFFER_SIZE, SEND_BUFFER_SIZE,
+    };
+    use test_fixture::{
+        addr, anti_replay, default_server_h3, fixture_init, new_server, now,
+        CountingConnectionIdGenerator, DEFAULT_ALPN_H3, DEFAULT_KEYS, DEFAULT_SERVER_NAME,
+    };
+
+    use super::{
+        AuthenticationStatus, Connection, Error, HSettings, Header, Http3Client, Http3ClientEvent,
+        Http3Parameters, Http3State, Rc, RefCell,
+    };
+    use crate::{
+        frames::{HFrame, H3_FRAME_TYPE_SETTINGS, H3_RESERVED_FRAME_TYPES},
+        qpack_encoder_receiver::EncoderRecvStream,
+        settings::{HSetting, HSettingType, H3_RESERVED_SETTINGS},
+        Http3Server, Priority, RecvStream,
+    };
+
+    fn assert_closed(client: &Http3Client, expected: &Error) {
+        match client.state() {
+            Http3State::Closing(err) | Http3State::Closed(err) => {
+                assert_eq!(err, ConnectionError::Application(expected.code()));
+            }
+            _ => panic!("Wrong state {:?}", client.state()),
+        };
+    }
+
+    /// Create a http3 client with default configuration.
+    pub fn default_http3_client() -> Http3Client {
+        default_http3_client_param(100)
+    }
+
+    pub fn default_http3_client_param(max_table_size: u64) -> Http3Client {
+        fixture_init();
+        Http3Client::new(
+            DEFAULT_SERVER_NAME,
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            addr(),
+            addr(),
+            Http3Parameters::default()
+                .connection_parameters(
+                    // Disable compatible upgrade, which complicates tests.
+                    ConnectionParameters::default()
+                        .versions(Version::default(), vec![Version::default()]),
+                )
+                .max_table_size_encoder(max_table_size)
+                .max_table_size_decoder(max_table_size)
+                .max_blocked_streams(100)
+                .max_concurrent_push_streams(5),
+            now(),
+        )
+        .expect("create a default client")
+    }
+
+    const CONTROL_STREAM_TYPE: &[u8] = &[0x0];
+
+    // Encoder stream data
+    const ENCODER_STREAM_DATA: &[u8] = &[0x2];
+    const ENCODER_STREAM_CAP_INSTRUCTION: &[u8] = &[0x3f, 0x45];
+
+    // Encoder stream data with a change capacity instruction(0x3f, 0x45 = change capacity to 100)
+    // This data will be send when 0-RTT is used and we already have a max_table_capacity from
+    // resumed settings.
+    const ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION: &[u8] = &[0x2, 0x3f, 0x45];
+
+    const ENCODER_STREAM_DATA_WITH_CAP_INST_AND_ENCODING_INST: &[u8] = &[
+        0x2, 0x3f, 0x45, 0x67, 0xa7, 0xd4, 0xe5, 0x1c, 0x85, 0xb1, 0x1f, 0x86, 0xa7, 0xd7, 0x71,
+        0xd1, 0x69, 0x7f,
+    ];
+
+    // Decoder stream data
+    const DECODER_STREAM_DATA: &[u8] = &[0x3];
+
+    const PUSH_STREAM_TYPE: &[u8] = &[0x1];
+
+    const CLIENT_SIDE_CONTROL_STREAM_ID: StreamId = StreamId::new(2);
+    const CLIENT_SIDE_ENCODER_STREAM_ID: StreamId = StreamId::new(6);
+    const CLIENT_SIDE_DECODER_STREAM_ID: StreamId = StreamId::new(10);
+
+    struct TestServer {
+        settings: HFrame,
+        conn: Connection,
+        control_stream_id: Option<StreamId>,
+        encoder: Rc<RefCell<QPackEncoder>>,
+        encoder_receiver: EncoderRecvStream,
+        encoder_stream_id: Option<StreamId>,
+        decoder_stream_id: Option<StreamId>,
+    }
+
+    impl TestServer {
+        pub fn new() -> Self {
+            Self::new_with_settings(&[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ])
+        }
+
+        pub fn new_with_settings(server_settings: &[HSetting]) -> Self {
+            fixture_init();
+            let max_table_size = server_settings
+                .iter()
+                .find(|s| s.setting_type == HSettingType::MaxTableCapacity)
+                .map_or(100, |s| s.value);
+            let max_blocked_streams = u16::try_from(
+                server_settings
+                    .iter()
+                    .find(|s| s.setting_type == HSettingType::BlockedStreams)
+                    .map_or(100, |s| s.value),
+            )
+            .unwrap();
+            let qpack = Rc::new(RefCell::new(QPackEncoder::new(
+                &QpackSettings {
+                    max_table_size_encoder: max_table_size,
+                    max_table_size_decoder: max_table_size,
+                    max_blocked_streams,
+                },
+                true,
+            )));
+            Self {
+                settings: HFrame::Settings {
+                    settings: HSettings::new(server_settings),
+                },
+                conn: default_server_h3(),
+                control_stream_id: None,
+                encoder: Rc::clone(&qpack),
+                encoder_receiver: EncoderRecvStream::new(CLIENT_SIDE_DECODER_STREAM_ID, qpack),
+                encoder_stream_id: None,
+                decoder_stream_id: None,
+            }
+        }
+
+        pub fn new_with_conn(conn: Connection) -> Self {
+            let qpack = Rc::new(RefCell::new(QPackEncoder::new(
+                &QpackSettings {
+                    max_table_size_encoder: 128,
+                    max_table_size_decoder: 128,
+                    max_blocked_streams: 0,
+                },
+                true,
+            )));
+            Self {
+                settings: HFrame::Settings {
+                    settings: HSettings::new(&[]),
+                },
+                conn,
+                control_stream_id: None,
+                encoder: Rc::clone(&qpack),
+                encoder_receiver: EncoderRecvStream::new(CLIENT_SIDE_DECODER_STREAM_ID, qpack),
+                encoder_stream_id: None,
+                decoder_stream_id: None,
+            }
+        }
+
+        pub fn create_qpack_streams(&mut self) {
+            // Create a QPACK encoder stream
+            self.encoder_stream_id = Some(self.conn.stream_create(StreamType::UniDi).unwrap());
+            self.encoder
+                .borrow_mut()
+                .add_send_stream(self.encoder_stream_id.unwrap());
+            self.encoder
+                .borrow_mut()
+                .send_encoder_updates(&mut self.conn)
+                .unwrap();
+
+            // Create decoder stream
+            self.decoder_stream_id = Some(self.conn.stream_create(StreamType::UniDi).unwrap());
+            assert_eq!(
+                self.conn
+                    .stream_send(self.decoder_stream_id.unwrap(), DECODER_STREAM_DATA)
+                    .unwrap(),
+                1
+            );
+        }
+
+        pub fn create_control_stream(&mut self) {
+            // Create control stream
+            let control = self.conn.stream_create(StreamType::UniDi).unwrap();
+            qtrace!(["TestServer"], "control stream: {}", control);
+            self.control_stream_id = Some(control);
+            // Send stream type on the control stream.
+            assert_eq!(
+                self.conn
+                    .stream_send(self.control_stream_id.unwrap(), CONTROL_STREAM_TYPE)
+                    .unwrap(),
+                1
+            );
+
+            // Encode a settings frame and send it.
+            let mut enc = Encoder::default();
+            self.settings.encode(&mut enc);
+            assert_eq!(
+                self.conn
+                    .stream_send(self.control_stream_id.unwrap(), enc.as_ref())
+                    .unwrap(),
+                enc.len()
+            );
+        }
+
+        pub fn check_client_control_qpack_streams_no_resumption(&mut self) {
+            self.check_client_control_qpack_streams(
+                ENCODER_STREAM_DATA,
+                EXPECTED_REQUEST_HEADER_FRAME,
+                false,
+                true,
+            );
+        }
+
+        pub fn check_control_qpack_request_streams_resumption(
+            &mut self,
+            expect_encoder_stream_data: &[u8],
+            expect_request_header: &[u8],
+            expect_request: bool,
+        ) {
+            self.check_client_control_qpack_streams(
+                expect_encoder_stream_data,
+                expect_request_header,
+                expect_request,
+                false,
+            );
+        }
+
+        // Check that server has received correct settings and qpack streams.
+        pub fn check_client_control_qpack_streams(
+            &mut self,
+            expect_encoder_stream_data: &[u8],
+            expect_request_header: &[u8],
+            expect_request: bool,
+            expect_connected: bool,
+        ) {
+            let mut connected = false;
+            let mut control_stream = false;
+            let mut qpack_decoder_stream = false;
+            let mut qpack_encoder_stream = false;
+            let mut request = false;
+            while let Some(e) = self.conn.next_event() {
+                match e {
+                    ConnectionEvent::NewStream { stream_id }
+                    | ConnectionEvent::SendStreamWritable { stream_id } => {
+                        if expect_request {
+                            assert!(matches!(stream_id.as_u64(), 2 | 6 | 10 | 0));
+                        } else {
+                            assert!(matches!(stream_id.as_u64(), 2 | 6 | 10));
+                        }
+                    }
+                    ConnectionEvent::RecvStreamReadable { stream_id } => {
+                        if stream_id == CLIENT_SIDE_CONTROL_STREAM_ID {
+                            self.check_control_stream();
+                            control_stream = true;
+                        } else if stream_id == CLIENT_SIDE_ENCODER_STREAM_ID {
+                            // the qpack encoder stream
+                            self.read_and_check_stream_data(
+                                stream_id,
+                                expect_encoder_stream_data,
+                                false,
+                            );
+                            qpack_encoder_stream = true;
+                        } else if stream_id == CLIENT_SIDE_DECODER_STREAM_ID {
+                            // the qpack decoder stream
+                            self.read_and_check_stream_data(stream_id, DECODER_STREAM_DATA, false);
+                            qpack_decoder_stream = true;
+                        } else if stream_id == 0 {
+                            assert!(expect_request);
+                            self.read_and_check_stream_data(stream_id, expect_request_header, true);
+                            request = true;
+                        } else {
+                            panic!("unexpected event");
+                        }
+                    }
+                    ConnectionEvent::StateChange(State::Connected) => connected = true,
+                    ConnectionEvent::StateChange(_)
+                    | ConnectionEvent::SendStreamCreatable { .. } => {}
+                    _ => panic!("unexpected event"),
+                }
+            }
+            assert_eq!(connected, expect_connected);
+            assert!(control_stream);
+            assert!(qpack_encoder_stream);
+            assert!(qpack_decoder_stream);
+            assert_eq!(request, expect_request);
+        }
+
+        // Check that the control stream contains default values.
+        // Expect a SETTINGS frame, some grease, and a MAX_PUSH_ID frame.
+        // The default test configuration uses:
+        //  - max_table_capacity = 100
+        //  - max_blocked_streams = 100
+        // and a maximum of 5 push streams.
+        fn check_control_stream(&mut self) {
+            let mut buf = [0_u8; 100];
+            let (amount, fin) = self
+                .conn
+                .stream_recv(CLIENT_SIDE_CONTROL_STREAM_ID, &mut buf)
+                .unwrap();
+            let mut dec = Decoder::from(&buf[..amount]);
+            assert_eq!(dec.decode_varint().unwrap(), 0); // control stream type
+            assert_eq!(dec.decode_varint().unwrap(), 4); // SETTINGS
+            assert_eq!(
+                dec.decode_vvec().unwrap(),
+                &[1, 0x40, 0x64, 7, 0x40, 0x64, 0xab, 0x60, 0x37, 0x42, 0x00]
+            );
+
+            assert_eq!((dec.decode_varint().unwrap() - 0x21) % 0x1f, 0); // Grease
+            assert!(dec.decode_vvec().unwrap().len() < 8);
+
+            assert_eq!(dec.decode_varint().unwrap(), 0xd); // MAX_PUSH_ID
+            assert_eq!(dec.decode_vvec().unwrap(), &[5]);
+
+            assert_eq!(dec.remaining(), 0);
+            assert!(!fin);
+        }
+
+        pub fn read_and_check_stream_data(
+            &mut self,
+            stream_id: StreamId,
+            expected_data: &[u8],
+            expected_fin: bool,
+        ) {
+            let mut buf = [0_u8; 100];
+            let (amount, fin) = self.conn.stream_recv(stream_id, &mut buf).unwrap();
+            assert_eq!(fin, expected_fin);
+            assert_eq!(amount, expected_data.len());
+            assert_eq!(&buf[..amount], expected_data);
+        }
+
+        pub fn encode_headers(
+            &mut self,
+            stream_id: StreamId,
+            headers: &[Header],
+            encoder: &mut Encoder,
+        ) {
+            let header_block =
+                self.encoder
+                    .borrow_mut()
+                    .encode_header_block(&mut self.conn, headers, stream_id);
+            let hframe = HFrame::Headers {
+                header_block: header_block.as_ref().to_vec(),
+            };
+            hframe.encode(encoder);
+        }
+    }
+
+    fn handshake_only(client: &mut Http3Client, server: &mut TestServer) -> Output {
+        assert_eq!(client.state(), Http3State::Initializing);
+        let out = client.process(None, now());
+        assert_eq!(client.state(), Http3State::Initializing);
+
+        assert_eq!(*server.conn.state(), State::Init);
+        let out = server.conn.process(out.as_dgram_ref(), now());
+        assert_eq!(*server.conn.state(), State::Handshaking);
+
+        let out = client.process(out.as_dgram_ref(), now());
+        let out = server.conn.process(out.as_dgram_ref(), now());
+        assert!(out.as_dgram_ref().is_none());
+
+        let authentication_needed = |e| matches!(e, Http3ClientEvent::AuthenticationNeeded);
+        assert!(client.events().any(authentication_needed));
+        client.authenticated(AuthenticationStatus::Ok, now());
+        out
+    }
+
+    // Perform only Quic transport handshake.
+    fn connect_only_transport_with(client: &mut Http3Client, server: &mut TestServer) {
+        let out = handshake_only(client, server);
+
+        let out = client.process(out.as_dgram_ref(), now());
+        let connected = |e| matches!(e, Http3ClientEvent::StateChange(Http3State::Connected));
+        assert!(client.events().any(connected));
+
+        assert_eq!(client.state(), Http3State::Connected);
+        server
+            .conn
+            .process_input(out.as_dgram_ref().unwrap(), now());
+        assert!(server.conn.state().connected());
+    }
+
+    // Perform only Quic transport handshake.
+    fn connect_only_transport() -> (Http3Client, TestServer) {
+        let mut client = default_http3_client();
+        let mut server = TestServer::new();
+        connect_only_transport_with(&mut client, &mut server);
+        (client, server)
+    }
+
+    fn send_and_receive_client_settings(client: &mut Http3Client, server: &mut TestServer) {
+        // send and receive client settings
+        let out = client.process(None, now());
+        server
+            .conn
+            .process_input(out.as_dgram_ref().unwrap(), now());
+        server.check_client_control_qpack_streams_no_resumption();
+    }
+
+    // Perform Quic transport handshake and exchange Http3 settings.
+    fn connect_with(client: &mut Http3Client, server: &mut TestServer) {
+        connect_only_transport_with(client, server);
+
+        send_and_receive_client_settings(client, server);
+
+        server.create_control_stream();
+
+        server.create_qpack_streams();
+        // Send the server's control and qpack streams data.
+        let out = server.conn.process(None, now());
+        client.process_input(out.as_dgram_ref().unwrap(), now());
+
+        // assert no error occured.
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Perform Quic transport handshake and exchange Http3 settings.
+    fn connect_with_connection_parameters(
+        server_conn_params: ConnectionParameters,
+    ) -> (Http3Client, TestServer) {
+        // connecting with default max_table_size
+        let mut client = default_http3_client_param(100);
+        let server = Connection::new_server(
+            test_fixture::DEFAULT_KEYS,
+            test_fixture::DEFAULT_ALPN_H3,
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            server_conn_params,
+        )
+        .unwrap();
+        let mut server = TestServer::new_with_conn(server);
+        connect_with(&mut client, &mut server);
+        (client, server)
+    }
+
+    // Perform Quic transport handshake and exchange Http3 settings.
+    fn connect() -> (Http3Client, TestServer) {
+        let mut client = default_http3_client();
+        let mut server = TestServer::new();
+        connect_with(&mut client, &mut server);
+        (client, server)
+    }
+
+    // Fetch request fetch("GET", "https", "something.com", "/", headers).
+    fn make_request(
+        client: &mut Http3Client,
+        close_sending_side: bool,
+        headers: &[Header],
+    ) -> StreamId {
+        let request_stream_id = client
+            .fetch(
+                now(),
+                "GET",
+                "https://something.com/",
+                headers,
+                Priority::default(),
+            )
+            .unwrap();
+        if close_sending_side {
+            client.stream_close_send(request_stream_id).unwrap();
+        }
+        request_stream_id
+    }
+
+    // For fetch request fetch("GET", "https", "something.com", "/", &[])
+    // the following request header frame will be sent:
+    const EXPECTED_REQUEST_HEADER_FRAME: &[u8] = &[
+        0x01, 0x10, 0x00, 0x00, 0xd1, 0xd7, 0x50, 0x89, 0x41, 0xe9, 0x2a, 0x67, 0x35, 0x53, 0x2e,
+        0x43, 0xd3, 0xc1,
+    ];
+
+    // For fetch request fetch("GET", "https", "something.com", "/", &[(String::from("myheaders",
+    // "myvalue"))]) the following request header frame will be sent:
+    const EXPECTED_REQUEST_HEADER_FRAME_VERSION2: &[u8] = &[
+        0x01, 0x11, 0x02, 0x80, 0xd1, 0xd7, 0x50, 0x89, 0x41, 0xe9, 0x2a, 0x67, 0x35, 0x53, 0x2e,
+        0x43, 0xd3, 0xc1, 0x10,
+    ];
+
+    const HTTP_HEADER_FRAME_0: &[u8] = &[0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x30];
+
+    // The response header from HTTP_HEADER_FRAME (0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x30)
+    // are decoded into:
+    fn check_response_header_0(header: &[Header]) {
+        let expected_response_header_0 = &[
+            Header::new(":status", "200"),
+            Header::new("content-length", "0"),
+        ];
+        assert_eq!(header, expected_response_header_0);
+    }
+
+    const HTTP_RESPONSE_1: &[u8] = &[
+        // headers
+        0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x37, // the first data frame
+        0x0, 0x3, 0x61, 0x62, 0x63, // the second data frame
+        0x0, 0x4, 0x64, 0x65, 0x66, 0x67,
+    ];
+
+    const HTTP_RESPONSE_HEADER_ONLY_1: &[u8] = &[
+        // headers
+        0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x37,
+    ];
+    const HTTP_RESPONSE_DATA_FRAME_1_ONLY_1: &[u8] = &[0x0, 0x3, 0x61, 0x62, 0x63];
+
+    const HTTP_RESPONSE_DATA_FRAME_2_ONLY_1: &[u8] = &[0x0, 0x4, 0x64, 0x65, 0x66, 0x67];
+
+    // The response header from HTTP_RESPONSE_1 (0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x36) are
+    // decoded into:
+    fn check_response_header_1(header: &[Header]) {
+        let expected_response_header_1 = &[
+            Header::new(":status", "200"),
+            Header::new("content-length", "7"),
+        ];
+        assert_eq!(header, expected_response_header_1);
+    }
+
+    const EXPECTED_RESPONSE_DATA_1: &[u8] = &[0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67];
+
+    const HTTP_RESPONSE_2: &[u8] = &[
+        // headers
+        0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x33, // the data frame
+        0x0, 0x3, 0x61, 0x62, 0x63,
+    ];
+
+    const HTTP_RESPONSE_HEADER_ONLY_2: &[u8] = &[
+        // headers
+        0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x33,
+    ];
+
+    const HTTP_RESPONSE_DATA_FRAME_ONLY_2: &[u8] = &[
+        // the data frame
+        0x0, 0x3, 0x61, 0x62, 0x63,
+    ];
+
+    // The response header from HTTP_RESPONSE_2 (0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x36) are
+    // decoded into:
+    fn check_response_header_2(header: &[Header]) {
+        let expected_response_header_2 = &[
+            Header::new(":status", "200"),
+            Header::new("content-length", "3"),
+        ];
+        assert_eq!(header, expected_response_header_2);
+    }
+
+    // The data frame payload from HTTP_RESPONSE_2 is:
+    const EXPECTED_RESPONSE_DATA_2_FRAME_1: &[u8] = &[0x61, 0x62, 0x63];
+
+    fn make_request_and_exchange_pkts(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        close_sending_side: bool,
+    ) -> StreamId {
+        let request_stream_id = make_request(client, close_sending_side, &[]);
+
+        let out = client.process(None, now());
+        server
+            .conn
+            .process_input(out.as_dgram_ref().unwrap(), now());
+
+        // find the new request/response stream and send frame v on it.
+        while let Some(e) = server.conn.next_event() {
+            match e {
+                ConnectionEvent::NewStream { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(stream_id.stream_type(), StreamType::BiDi);
+                }
+                ConnectionEvent::RecvStreamReadable { stream_id } => {
+                    if stream_id == CLIENT_SIDE_ENCODER_STREAM_ID {
+                        server.read_and_check_stream_data(
+                            stream_id,
+                            ENCODER_STREAM_CAP_INSTRUCTION,
+                            false,
+                        );
+                    } else {
+                        assert_eq!(stream_id, request_stream_id);
+                        server.read_and_check_stream_data(
+                            stream_id,
+                            EXPECTED_REQUEST_HEADER_FRAME,
+                            close_sending_side,
+                        );
+                    }
+                }
+                _ => {}
+            }
+        }
+        let dgram = server.conn.process_output(now()).dgram();
+        if let Some(d) = dgram {
+            client.process_input(&d, now());
+        }
+        request_stream_id
+    }
+
+    fn connect_and_send_request(close_sending_side: bool) -> (Http3Client, TestServer, StreamId) {
+        let (mut client, mut server) = connect();
+        let request_stream_id =
+            make_request_and_exchange_pkts(&mut client, &mut server, close_sending_side);
+        assert_eq!(request_stream_id, 0);
+
+        (client, server, request_stream_id)
+    }
+
+    fn server_send_response_and_exchange_packet(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        stream_id: StreamId,
+        response: impl AsRef<[u8]>,
+        close_stream: bool,
+    ) {
+        _ = server
+            .conn
+            .stream_send(stream_id, response.as_ref())
+            .unwrap();
+        if close_stream {
+            server.conn.stream_close_send(stream_id).unwrap();
+        }
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+    }
+
+    const PUSH_PROMISE_DATA: &[u8] = &[
+        0x00, 0x00, 0xd1, 0xd7, 0x50, 0x89, 0x41, 0xe9, 0x2a, 0x67, 0x35, 0x53, 0x2e, 0x43, 0xd3,
+        0xc1,
+    ];
+
+    fn check_pushpromise_header(header: &[Header]) {
+        let expected_response_header_1 = &[
+            Header::new(":method", "GET"),
+            Header::new(":scheme", "https"),
+            Header::new(":authority", "something.com"),
+            Header::new(":path", "/"),
+        ];
+        assert_eq!(header, expected_response_header_1);
+    }
+
+    // Send a push promise with push_id and request_stream_id.
+    fn send_push_promise(conn: &mut Connection, stream_id: StreamId, push_id: u64) {
+        let frame = HFrame::PushPromise {
+            push_id,
+            header_block: PUSH_PROMISE_DATA.to_vec(),
+        };
+        let mut d = Encoder::default();
+        frame.encode(&mut d);
+        _ = conn.stream_send(stream_id, d.as_ref()).unwrap();
+    }
+
+    fn send_push_data_and_exchange_packets(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        push_id: u8,
+        close_push_stream: bool,
+    ) -> StreamId {
+        let push_stream_id = send_push_data(&mut server.conn, push_id, close_push_stream);
+
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        push_stream_id
+    }
+
+    fn send_push_promise_and_exchange_packets(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        stream_id: StreamId,
+        push_id: u64,
+    ) {
+        send_push_promise(&mut server.conn, stream_id, push_id);
+
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+    }
+
+    fn send_cancel_push_and_exchange_packets(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        push_id: u64,
+    ) {
+        let frame = HFrame::CancelPush { push_id };
+        let mut d = Encoder::default();
+        frame.encode(&mut d);
+        server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), d.as_ref())
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+    }
+
+    const PUSH_DATA: &[u8] = &[
+        // headers
+        0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x34, // the data frame.
+        0x0, 0x4, 0x61, 0x62, 0x63, 0x64,
+    ];
+
+    // The response header from PUSH_DATA (0x01, 0x06, 0x00, 0x00, 0xd9, 0x54, 0x01, 0x34) are
+    // decoded into:
+    fn check_push_response_header(header: &[Header]) {
+        let expected_push_response_header = vec![
+            Header::new(":status", "200"),
+            Header::new("content-length", "4"),
+        ];
+        assert_eq!(header, &expected_push_response_header[..]);
+    }
+
+    // The data frame payload from PUSH_DATA is:
+    const EXPECTED_PUSH_RESPONSE_DATA_FRAME: &[u8] = &[0x61, 0x62, 0x63, 0x64];
+
+    // Send push data on a push stream:
+    //  1) push_stream_type PUSH_STREAM_TYPE
+    //  2) push_id
+    //  3) PUSH_DATA that contains encoded headers and a data frame.
+    // This function can only handle small push_id numbers that fit in a varint of length 1 byte.
+    fn send_data_on_push(
+        conn: &mut Connection,
+        push_stream_id: StreamId,
+        push_id: u8,
+        data: impl AsRef<[u8]>,
+        close_push_stream: bool,
+    ) {
+        // send data
+        _ = conn.stream_send(push_stream_id, PUSH_STREAM_TYPE).unwrap();
+        _ = conn.stream_send(push_stream_id, &[push_id]).unwrap();
+        _ = conn.stream_send(push_stream_id, data.as_ref()).unwrap();
+        if close_push_stream {
+            conn.stream_close_send(push_stream_id).unwrap();
+        }
+    }
+
+    // Send push data on a push stream:
+    //  1) push_stream_type PUSH_STREAM_TYPE
+    //  2) push_id
+    //  3) PUSH_DATA that contains encoded headers and a data frame.
+    // This function can only handle small push_id numbers that fit in a varint of length 1 byte.
+    fn send_push_data(conn: &mut Connection, push_id: u8, close_push_stream: bool) -> StreamId {
+        send_push_with_data(conn, push_id, PUSH_DATA, close_push_stream)
+    }
+
+    // Send push data on a push stream:
+    //  1) push_stream_type PUSH_STREAM_TYPE
+    //  2) push_id
+    //  3) and supplied push data.
+    // This function can only handle small push_id numbers that fit in a varint of length 1 byte.
+    fn send_push_with_data(
+        conn: &mut Connection,
+        push_id: u8,
+        data: &[u8],
+        close_push_stream: bool,
+    ) -> StreamId {
+        // create a push stream
+        let push_stream_id = conn.stream_create(StreamType::UniDi).unwrap();
+        // send data
+        send_data_on_push(conn, push_stream_id, push_id, data, close_push_stream);
+        push_stream_id
+    }
+
+    struct PushPromiseInfo {
+        pub push_id: u64,
+        pub ref_stream_id: StreamId,
+    }
+
+    // Helper function: read response when a server sends:
+    // - HTTP_RESPONSE_2 on the request_stream_id stream,
+    // - a number of push promises described by a list of PushPromiseInfo.
+    // - and a push streams with push_id in the push_streams list.
+    // All push stream contain PUSH_DATA that decodes to headers (that can be checked by calling
+    // check_push_response_header) and EXPECTED_PUSH_RESPONSE_DATA_FRAME
+    fn read_response_and_push_events(
+        client: &mut Http3Client,
+        push_promises: &[PushPromiseInfo],
+        push_streams: &[u64],
+        response_stream_id: StreamId,
+    ) {
+        let mut num_push_promises = 0;
+        let mut num_push_stream_headers = 0;
+        let mut num_push_stream_data = 0;
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::PushPromise {
+                    push_id,
+                    request_stream_id,
+                    headers,
+                } => {
+                    assert!(push_promises
+                        .iter()
+                        .any(|p| p.push_id == push_id && p.ref_stream_id == request_stream_id));
+                    check_pushpromise_header(&headers[..]);
+                    num_push_promises += 1;
+                }
+                Http3ClientEvent::PushHeaderReady {
+                    push_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert!(push_streams.contains(&push_id));
+                    check_push_response_header(&headers);
+                    num_push_stream_headers += 1;
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::PushDataReadable { push_id } => {
+                    assert!(push_streams.contains(&push_id));
+                    let mut buf = [0_u8; 100];
+                    let (amount, fin) = client.push_read_data(now(), push_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(amount, EXPECTED_PUSH_RESPONSE_DATA_FRAME.len());
+                    assert_eq!(&buf[..amount], EXPECTED_PUSH_RESPONSE_DATA_FRAME);
+                    num_push_stream_data += 1;
+                }
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, response_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, response_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let (amount, _) = client.read_data(now(), stream_id, &mut buf).unwrap();
+                    assert_eq!(amount, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+                    assert_eq!(&buf[..amount], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+                }
+                _ => {}
+            }
+        }
+
+        assert_eq!(num_push_promises, push_promises.len());
+        assert_eq!(num_push_stream_headers, push_streams.len());
+        assert_eq!(num_push_stream_data, push_streams.len());
+    }
+
+    // Client: Test receiving a new control stream and a SETTINGS frame.
+    #[test]
+    fn test_client_connect_and_exchange_qpack_and_control_streams() {
+        mem::drop(connect());
+    }
+
+    // Client: Test that the connection will be closed if control stream
+    // has been closed.
+    #[test]
+    fn test_client_close_control_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_close_send(server.control_stream_id.unwrap())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the local control stream
+    // has been reset.
+    #[test]
+    fn test_client_reset_control_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_reset_send(server.control_stream_id.unwrap(), Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the server side encoder stream
+    // has been reset.
+    #[test]
+    fn test_client_reset_server_side_encoder_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_reset_send(server.encoder_stream_id.unwrap(), Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the server side decoder stream
+    // has been reset.
+    #[test]
+    fn test_client_reset_server_side_decoder_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_reset_send(server.decoder_stream_id.unwrap(), Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the local control stream
+    // has received a stop_sending.
+    #[test]
+    fn test_client_stop_sending_control_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_stop_sending(CLIENT_SIDE_CONTROL_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the client side encoder stream
+    // has received a stop_sending.
+    #[test]
+    fn test_client_stop_sending_encoder_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_stop_sending(CLIENT_SIDE_ENCODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: Test that the connection will be closed if the client side decoder stream
+    // has received a stop_sending.
+    #[test]
+    fn test_client_stop_sending_decoder_stream() {
+        let (mut client, mut server) = connect();
+        server
+            .conn
+            .stream_stop_sending(CLIENT_SIDE_DECODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpClosedCriticalStream);
+    }
+
+    // Client: test missing SETTINGS frame
+    // (the first frame sent is a garbage frame).
+    #[test]
+    fn test_client_missing_settings() {
+        let (mut client, mut server) = connect_only_transport();
+        // Create server control stream.
+        let control_stream = server.conn.stream_create(StreamType::UniDi).unwrap();
+        // Send a HEADERS frame instead (which contains garbage).
+        let sent = server
+            .conn
+            .stream_send(control_stream, &[0x0, 0x1, 0x3, 0x0, 0x1, 0x2]);
+        assert_eq!(sent, Ok(6));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpMissingSettings);
+    }
+
+    // Client: receiving SETTINGS frame twice causes connection close
+    // with error HTTP_UNEXPECTED_FRAME.
+    #[test]
+    fn test_client_receive_settings_twice() {
+        let (mut client, mut server) = connect();
+        // send the second SETTINGS frame.
+        let sent = server.conn.stream_send(
+            server.control_stream_id.unwrap(),
+            &[0x4, 0x6, 0x1, 0x40, 0x64, 0x7, 0x40, 0x64],
+        );
+        assert_eq!(sent, Ok(8));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    fn test_wrong_frame_on_control_stream(v: &[u8]) {
+        let (mut client, mut server) = connect();
+
+        // send a frame that is not allowed on the control stream.
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), v)
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    // send DATA frame on a cortrol stream
+    #[test]
+    fn test_data_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x0, 0x2, 0x1, 0x2]);
+    }
+
+    // send HEADERS frame on a cortrol stream
+    #[test]
+    fn test_headers_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x1, 0x2, 0x1, 0x2]);
+    }
+
+    // send PUSH_PROMISE frame on a cortrol stream
+    #[test]
+    fn test_push_promise_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x5, 0x2, 0x1, 0x2]);
+    }
+
+    // send PRIORITY_UPDATE frame on a control stream to the client
+    #[test]
+    fn test_priority_update_request_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x80, 0x0f, 0x07, 0x00, 0x01, 0x03]);
+    }
+
+    #[test]
+    fn test_priority_update_push_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x80, 0x0f, 0x07, 0x01, 0x01, 0x03]);
+    }
+
+    fn test_wrong_frame_on_push_stream(v: &[u8]) {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        // Create a push stream
+        let push_stream_id = server.conn.stream_create(StreamType::UniDi).unwrap();
+
+        // Send the push stream type byte, push_id and frame v.
+        _ = server
+            .conn
+            .stream_send(push_stream_id, &[0x01, 0x0])
+            .unwrap();
+        _ = server.conn.stream_send(push_stream_id, v).unwrap();
+
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    #[test]
+    fn test_cancel_push_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x3, 0x1, 0x5]);
+    }
+
+    #[test]
+    fn test_settings_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x4, 0x4, 0x6, 0x4, 0x8, 0x4]);
+    }
+
+    #[test]
+    fn test_push_promise_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x5, 0x2, 0x1, 0x2]);
+    }
+
+    #[test]
+    fn test_priority_update_request_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x80, 0x0f, 0x07, 0x00, 0x01, 0x03]);
+    }
+
+    #[test]
+    fn test_priority_update_push_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x80, 0x0f, 0x07, 0x01, 0x01, 0x03]);
+    }
+
+    #[test]
+    fn test_goaway_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x7, 0x1, 0x5]);
+    }
+
+    #[test]
+    fn test_max_push_id_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0xd, 0x1, 0x5]);
+    }
+
+    // send DATA frame before a header frame
+    #[test]
+    fn test_data_frame_on_push_stream() {
+        test_wrong_frame_on_push_stream(&[0x0, 0x2, 0x1, 0x2]);
+    }
+
+    // Client: receive unknown stream type
+    // This function also tests getting stream id that does not fit into a single byte.
+    #[test]
+    fn test_client_received_unknown_stream() {
+        let (mut client, mut server) = connect();
+
+        // create a stream with unknown type.
+        let new_stream_id = server.conn.stream_create(StreamType::UniDi).unwrap();
+        _ = server
+            .conn
+            .stream_send(new_stream_id, &[0x41, 0x19, 0x4, 0x4, 0x6, 0x0, 0x8, 0x0])
+            .unwrap();
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // check for stop-sending with Error::HttpStreamCreation.
+        let mut stop_sending_event_found = false;
+        while let Some(e) = server.conn.next_event() {
+            if let ConnectionEvent::SendStreamStopSending {
+                stream_id,
+                app_error,
+            } = e
+            {
+                stop_sending_event_found = true;
+                assert_eq!(stream_id, new_stream_id);
+                assert_eq!(app_error, Error::HttpStreamCreation.code());
+            }
+        }
+        assert!(stop_sending_event_found);
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test wrong frame on req/rec stream
+    fn test_wrong_frame_on_request_stream(v: &[u8]) {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        _ = server.conn.stream_send(request_stream_id, v).unwrap();
+
+        // Generate packet with the above bad h3 input
+        let out = server.conn.process(None, now());
+        // Process bad input and close the connection.
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    #[test]
+    fn test_cancel_push_frame_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0x3, 0x1, 0x5]);
+    }
+
+    #[test]
+    fn test_settings_frame_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0x4, 0x4, 0x6, 0x4, 0x8, 0x4]);
+    }
+
+    #[test]
+    fn test_goaway_frame_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0x7, 0x1, 0x5]);
+    }
+
+    #[test]
+    fn test_max_push_id_frame_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0xd, 0x1, 0x5]);
+    }
+
+    #[test]
+    fn test_priority_update_request_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0x80, 0x0f, 0x07, 0x00, 0x01, 0x03]);
+    }
+
+    #[test]
+    fn test_priority_update_push_on_request_stream() {
+        test_wrong_frame_on_request_stream(&[0x80, 0x0f, 0x07, 0x01, 0x01, 0x03]);
+    }
+
+    // Test reading of a slowly streamed frame. bytes are received one by one
+    #[test]
+    fn test_frame_reading() {
+        let (mut client, mut server) = connect_only_transport();
+
+        // create a control stream.
+        let control_stream = server.conn.stream_create(StreamType::UniDi).unwrap();
+
+        // send the stream type
+        let mut sent = server.conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // start sending SETTINGS frame
+        sent = server.conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x6]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x8]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_eq!(client.state(), Http3State::Connected);
+
+        // Now test PushPromise
+        sent = server.conn.stream_send(control_stream, &[0x5]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x5]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x61]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x62]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x63]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        sent = server.conn.stream_send(control_stream, &[0x64]);
+        assert_eq!(sent, Ok(1));
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // PUSH_PROMISE on a control stream will cause an error
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    #[test]
+    fn fetch_basic() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // send response - 200  Content-Length: 7
+        // with content: 'abcdefg'.
+        // The content will be send in 2 DATA frames.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        let http_events = client.events().collect::<Vec<_>>();
+        assert_eq!(http_events.len(), 2);
+        for e in http_events {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_1(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(amount, EXPECTED_RESPONSE_DATA_1.len());
+                    assert_eq!(&buf[..amount], EXPECTED_RESPONSE_DATA_1);
+                }
+                _ => {}
+            }
+        }
+
+        // after this stream will be removed from hcoon. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    /// Force both endpoints into an idle state.
+    /// Do this by opening unidirectional streams at both endpoints and sending
+    /// a partial unidirectional stream type (which the receiver has to buffer),
+    /// then delivering packets out of order.
+    /// This forces the receiver to create an acknowledgment, which will allow
+    /// the peer to become idle.
+    fn force_idle(client: &mut Http3Client, server: &mut TestServer) {
+        // Send a partial unidirectional stream ID.
+        // Note that this can't close the stream as that causes the receiver
+        // to send `MAX_STREAMS`, which would prevent it from becoming idle.
+        fn dgram(c: &mut Connection) -> Datagram {
+            let stream = c.stream_create(StreamType::UniDi).unwrap();
+            _ = c.stream_send(stream, &[0xc0]).unwrap();
+            c.process_output(now()).dgram().unwrap()
+        }
+
+        let d1 = dgram(&mut client.conn);
+        let d2 = dgram(&mut client.conn);
+        server.conn.process_input(&d2, now());
+        server.conn.process_input(&d1, now());
+        let d3 = dgram(&mut server.conn);
+        let d4 = dgram(&mut server.conn);
+        client.process_input(&d4, now());
+        client.process_input(&d3, now());
+        let ack = client.process_output(now()).dgram();
+        server.conn.process_input(&ack.unwrap(), now());
+    }
+
+    /// The client should keep a connection alive if it has unanswered requests.
+    #[test]
+    fn fetch_keep_alive() {
+        let (mut client, mut server, _request_stream_id) = connect_and_send_request(true);
+        force_idle(&mut client, &mut server);
+
+        let idle_timeout = ConnectionParameters::default().get_idle_timeout();
+        assert_eq!(client.process_output(now()).callback(), idle_timeout / 2);
+    }
+
+    // Helper function: read response when a server sends HTTP_RESPONSE_2.
+    fn read_response(
+        client: &mut Http3Client,
+        server: &mut Connection,
+        request_stream_id: StreamId,
+    ) {
+        let out = server.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(amount, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+                    assert_eq!(&buf[..amount], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+                }
+                _ => {}
+            }
+        }
+
+        // after this stream will be removed from client. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    // Data sent with a request:
+    const REQUEST_BODY: &[u8] = &[0x64, 0x65, 0x66];
+    // Corresponding data frame that server will receive.
+    const EXPECTED_REQUEST_BODY_FRAME: &[u8] = &[0x0, 0x3, 0x64, 0x65, 0x66];
+
+    // Send a request with the request body.
+    #[test]
+    fn fetch_with_data() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Get DataWritable for the request stream so that we can write the request body.
+        let data_writable = |e| matches!(e, Http3ClientEvent::DataWritable { .. });
+        assert!(client.events().any(data_writable));
+        let sent = client.send_data(request_stream_id, REQUEST_BODY).unwrap();
+        assert_eq!(sent, REQUEST_BODY.len());
+        client.stream_close_send(request_stream_id).unwrap();
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // find the new request/response stream and send response on it.
+        while let Some(e) = server.conn.next_event() {
+            match e {
+                ConnectionEvent::NewStream { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(stream_id.stream_type(), StreamType::BiDi);
+                }
+                ConnectionEvent::RecvStreamReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+
+                    // Read request body.
+                    let mut buf = [0_u8; 100];
+                    let (amount, fin) = server.conn.stream_recv(stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(amount, EXPECTED_REQUEST_BODY_FRAME.len());
+                    assert_eq!(&buf[..amount], EXPECTED_REQUEST_BODY_FRAME);
+
+                    // send response - 200  Content-Length: 3
+                    // with content: 'abc'.
+                    _ = server.conn.stream_send(stream_id, HTTP_RESPONSE_2).unwrap();
+                    server.conn.stream_close_send(stream_id).unwrap();
+                }
+                _ => {}
+            }
+        }
+
+        read_response(&mut client, &mut server.conn, request_stream_id);
+    }
+
+    // send a request with request body containing request_body. We expect to receive
+    // expected_data_frame_header.
+    fn fetch_with_data_length_xbytes(request_body: &[u8], expected_data_frame_header: &[u8]) {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Get DataWritable for the request stream so that we can write the request body.
+        let data_writable = |e| matches!(e, Http3ClientEvent::DataWritable { .. });
+        assert!(client.events().any(data_writable));
+        let sent = client.send_data(request_stream_id, request_body);
+        assert_eq!(sent, Ok(request_body.len()));
+
+        // Close stream.
+        client.stream_close_send(request_stream_id).unwrap();
+
+        // We need to loop a bit until all data has been sent.
+        let mut out = client.process(None, now());
+        for _i in 0..20 {
+            out = server.conn.process(out.as_dgram_ref(), now());
+            out = client.process(out.as_dgram_ref(), now());
+        }
+
+        // check request body is received.
+        // Then send a response.
+        while let Some(e) = server.conn.next_event() {
+            if let ConnectionEvent::RecvStreamReadable { stream_id } = e {
+                if stream_id == request_stream_id {
+                    // Read the DATA frame.
+                    let mut buf = vec![1_u8; RECV_BUFFER_SIZE];
+                    let (amount, fin) = server.conn.stream_recv(stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(
+                        amount,
+                        request_body.len() + expected_data_frame_header.len()
+                    );
+
+                    // Check the DATA frame header
+                    assert_eq!(
+                        &buf[..expected_data_frame_header.len()],
+                        expected_data_frame_header
+                    );
+
+                    // Check data.
+                    assert_eq!(&buf[expected_data_frame_header.len()..amount], request_body);
+
+                    // send response - 200  Content-Length: 3
+                    // with content: 'abc'.
+                    _ = server.conn.stream_send(stream_id, HTTP_RESPONSE_2).unwrap();
+                    server.conn.stream_close_send(stream_id).unwrap();
+                }
+            }
+        }
+
+        read_response(&mut client, &mut server.conn, request_stream_id);
+    }
+
+    // send a request with 63 bytes. The DATA frame length field will still have 1 byte.
+    #[test]
+    fn fetch_with_data_length_63bytes() {
+        fetch_with_data_length_xbytes(&[0_u8; 63], &[0x0, 0x3f]);
+    }
+
+    // send a request with 64 bytes. The DATA frame length field will need 2 byte.
+    #[test]
+    fn fetch_with_data_length_64bytes() {
+        fetch_with_data_length_xbytes(&[0_u8; 64], &[0x0, 0x40, 0x40]);
+    }
+
+    // send a request with 16383 bytes. The DATA frame length field will still have 2 byte.
+    #[test]
+    fn fetch_with_data_length_16383bytes() {
+        fetch_with_data_length_xbytes(&[0_u8; 16383], &[0x0, 0x7f, 0xff]);
+    }
+
+    // send a request with 16384 bytes. The DATA frame length field will need 4 byte.
+    #[test]
+    fn fetch_with_data_length_16384bytes() {
+        fetch_with_data_length_xbytes(&[0_u8; 16384], &[0x0, 0x80, 0x0, 0x40, 0x0]);
+    }
+
+    // Send 2 data frames so that the second one cannot fit into the send_buf and it is only
+    // partialy sent. We check that the sent data is correct.
+    #[allow(clippy::useless_vec)]
+    fn fetch_with_two_data_frames(
+        first_frame: &[u8],
+        expected_first_data_frame_header: &[u8],
+        expected_second_data_frame_header: &[u8],
+        expected_second_data_frame: &[u8],
+    ) {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Get DataWritable for the request stream so that we can write the request body.
+        let data_writable = |e| matches!(e, Http3ClientEvent::DataWritable { .. });
+        assert!(client.events().any(data_writable));
+
+        // Send the first frame.
+        let sent = client.send_data(request_stream_id, first_frame);
+        assert_eq!(sent, Ok(first_frame.len()));
+
+        // The second frame cannot fit.
+        let sent = client.send_data(request_stream_id, &vec![0_u8; SEND_BUFFER_SIZE]);
+        assert_eq!(sent, Ok(expected_second_data_frame.len()));
+
+        // Close stream.
+        client.stream_close_send(request_stream_id).unwrap();
+
+        let mut out = client.process(None, now());
+        // We need to loop a bit until all data has been sent. Once for every 1K
+        // of data.
+        for _i in 0..SEND_BUFFER_SIZE / 1000 {
+            out = server.conn.process(out.as_dgram_ref(), now());
+            out = client.process(out.as_dgram_ref(), now());
+        }
+
+        // Check received frames and send a response.
+        while let Some(e) = server.conn.next_event() {
+            if let ConnectionEvent::RecvStreamReadable { stream_id } = e {
+                if stream_id == request_stream_id {
+                    // Read DATA frames.
+                    let mut buf = vec![1_u8; RECV_BUFFER_SIZE];
+                    let (amount, fin) = server.conn.stream_recv(stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(
+                        amount,
+                        expected_first_data_frame_header.len()
+                            + first_frame.len()
+                            + expected_second_data_frame_header.len()
+                            + expected_second_data_frame.len()
+                    );
+
+                    // Check the first DATA frame header
+                    let end = expected_first_data_frame_header.len();
+                    assert_eq!(&buf[..end], expected_first_data_frame_header);
+
+                    // Check the first frame data.
+                    let start = end;
+                    let end = end + first_frame.len();
+                    assert_eq!(&buf[start..end], first_frame);
+
+                    // Check the second DATA frame header
+                    let start2 = end;
+                    let end2 = end + expected_second_data_frame_header.len();
+                    assert_eq!(&buf[start2..end2], expected_second_data_frame_header);
+
+                    // Check the second frame data.
+                    let start3 = end2;
+                    let end3 = end2 + expected_second_data_frame.len();
+                    assert_eq!(&buf[start3..end3], expected_second_data_frame);
+
+                    // send response - 200  Content-Length: 3
+                    // with content: 'abc'.
+                    _ = server.conn.stream_send(stream_id, HTTP_RESPONSE_2).unwrap();
+                    server.conn.stream_close_send(stream_id).unwrap();
+                }
+            }
+        }
+
+        read_response(&mut client, &mut server.conn, request_stream_id);
+    }
+
+    fn alloc_buffer(size: usize) -> (Vec<u8>, Vec<u8>) {
+        let data_frame = HFrame::Data { len: size as u64 };
+        let mut enc = Encoder::default();
+        data_frame.encode(&mut enc);
+
+        (vec![0_u8; size], enc.as_ref().to_vec())
+    }
+
+    // Send 2 frames. For the second one we can only send 63 bytes.
+    // After the first frame there is exactly 63+2 bytes left in the send buffer.
+    #[test]
+    fn fetch_two_data_frame_second_63bytes() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 88);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x3f], &[0_u8; 63]);
+    }
+
+    // Send 2 frames. For the second one we can only send 63 bytes.
+    // After the first frame there is exactly 63+3 bytes left in the send buffer,
+    // but we can only send 63 bytes.
+    #[test]
+    fn fetch_two_data_frame_second_63bytes_place_for_66() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 89);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x3f], &[0_u8; 63]);
+    }
+
+    // Send 2 frames. For the second one we can only send 64 bytes.
+    // After the first frame there is exactly 64+3 bytes left in the send buffer,
+    // but we can only send 64 bytes.
+    #[test]
+    fn fetch_two_data_frame_second_64bytes_place_for_67() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 90);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x40, 0x40], &[0_u8; 64]);
+    }
+
+    // Send 2 frames. For the second one we can only send 16383 bytes.
+    // After the first frame there is exactly 16383+3 bytes left in the send buffer.
+    #[test]
+    fn fetch_two_data_frame_second_16383bytes() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 16409);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x7f, 0xff], &[0_u8; 16383]);
+    }
+
+    // Send 2 frames. For the second one we can only send 16383 bytes.
+    // After the first frame there is exactly 16383+4 bytes left in the send buffer, but we can only
+    // send 16383 bytes.
+    #[test]
+    fn fetch_two_data_frame_second_16383bytes_place_for_16387() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 16410);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x7f, 0xff], &[0_u8; 16383]);
+    }
+
+    // Send 2 frames. For the second one we can only send 16383 bytes.
+    // After the first frame there is exactly 16383+5 bytes left in the send buffer, but we can only
+    // send 16383 bytes.
+    #[test]
+    fn fetch_two_data_frame_second_16383bytes_place_for_16388() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 16411);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x7f, 0xff], &[0_u8; 16383]);
+    }
+
+    // Send 2 frames. For the second one we can send 16384 bytes.
+    // After the first frame there is exactly 16384+5 bytes left in the send buffer, but we can send
+    // 16384 bytes.
+    #[test]
+    fn fetch_two_data_frame_second_16384bytes_place_for_16389() {
+        let (buf, hdr) = alloc_buffer(SEND_BUFFER_SIZE - 16412);
+        fetch_with_two_data_frames(&buf, &hdr, &[0x0, 0x80, 0x0, 0x40, 0x0], &[0_u8; 16384]);
+    }
+
+    // Test receiving STOP_SENDING with the HttpNoError error code.
+    #[test]
+    fn test_stop_sending_early_response() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Stop sending with early_response.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_stop_sending(request_stream_id, Error::HttpNoError.code())
+        );
+
+        // send response - 200  Content-Length: 3
+        // with content: 'abc'.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        let mut stop_sending = false;
+        let mut response_headers = false;
+        let mut response_body = false;
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpNoError.code());
+                    // assert that we cannot send any more request data.
+                    assert_eq!(
+                        Err(Error::InvalidStreamId),
+                        client.send_data(request_stream_id, &[0_u8; 10])
+                    );
+                    stop_sending = true;
+                }
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                    response_headers = true;
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let (amount, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+                    assert!(fin);
+                    assert_eq!(amount, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+                    assert_eq!(&buf[..amount], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+                    response_body = true;
+                }
+                _ => {}
+            }
+        }
+        assert!(response_headers);
+        assert!(response_body);
+        assert!(stop_sending);
+
+        // after this stream will be removed from client. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    // Server sends stop sending and reset.
+    #[test]
+    fn test_stop_sending_other_error_with_reset() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Stop sending with RequestRejected.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_stop_sending(request_stream_id, Error::HttpRequestRejected.code())
+        );
+        // also reset with RequestRejected.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_reset_send(request_stream_id, Error::HttpRequestRejected.code())
+        );
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut reset = false;
+        let mut stop_sending = false;
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestRejected.code());
+                    stop_sending = true;
+                }
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestRejected.code());
+                    assert!(!local);
+                    reset = true;
+                }
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not get any headers or data");
+                }
+                _ => {}
+            }
+        }
+
+        assert!(reset);
+        assert!(stop_sending);
+
+        // after this stream will be removed from client. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    // Server sends stop sending with RequestRejected, but it does not send reset.
+    #[test]
+    fn test_stop_sending_other_error_wo_reset() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Stop sending with RequestRejected.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_stop_sending(request_stream_id, Error::HttpRequestRejected.code())
+        );
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut stop_sending = false;
+
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestRejected.code());
+                    stop_sending = true;
+                }
+                Http3ClientEvent::Reset { .. } => {
+                    panic!("We should not get StopSending.");
+                }
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not get any headers or data");
+                }
+                _ => {}
+            }
+        }
+
+        assert!(stop_sending);
+
+        // after this we can still read from a stream.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_ok());
+
+        client.close(now(), 0, "");
+    }
+
+    // Server sends stop sending and reset. We have some events for that stream already
+    // in client.events. The events will be removed.
+    #[test]
+    fn test_stop_sending_and_reset_other_error_with_events() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // send response - 200  Content-Length: 3
+        // with content: 'abc'.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            false,
+        );
+        // At this moment we have some new events, i.e. a HeadersReady event
+
+        // Send a stop sending and reset.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_stop_sending(request_stream_id, Error::HttpRequestCancelled.code())
+        );
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_reset_send(request_stream_id, Error::HttpRequestCancelled.code())
+        );
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut reset = false;
+
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestCancelled.code());
+                }
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestCancelled.code());
+                    assert!(!local);
+                    reset = true;
+                }
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not get any headers or data");
+                }
+                _ => {}
+            }
+        }
+
+        assert!(reset);
+
+        // after this stream will be removed from client. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    // Server sends stop sending with code that is not HttpNoError.
+    // We have some events for that stream already in the client.events.
+    // The events will be removed.
+    #[test]
+    fn test_stop_sending_other_error_with_events() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // send response - 200  Content-Length: 3
+        // with content: 'abc'.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            false,
+        );
+        // At this moment we have some new event, i.e. a HeadersReady event
+
+        // Send a stop sending.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_stop_sending(request_stream_id, Error::HttpRequestCancelled.code())
+        );
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut stop_sending = false;
+        let mut header_ready = false;
+
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestCancelled.code());
+                    stop_sending = true;
+                }
+                Http3ClientEvent::Reset { .. } => {
+                    panic!("We should not get StopSending.");
+                }
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::DataReadable { .. } => {
+                    header_ready = true;
+                }
+                _ => {}
+            }
+        }
+
+        assert!(stop_sending);
+        assert!(header_ready);
+
+        // after this, we can sill read data from a sttream.
+        let mut buf = [0_u8; 100];
+        let (amount, fin) = client
+            .read_data(now(), request_stream_id, &mut buf)
+            .unwrap();
+        assert!(!fin);
+        assert_eq!(amount, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+        assert_eq!(&buf[..amount], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+
+        client.close(now(), 0, "");
+    }
+
+    // Server sends a reset. We will close sending side as well.
+    #[test]
+    fn test_reset_wo_stop_sending() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Send a reset.
+        assert_eq!(
+            Ok(()),
+            server
+                .conn
+                .stream_reset_send(request_stream_id, Error::HttpRequestCancelled.code())
+        );
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut reset = false;
+
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::StopSending { .. } => {
+                    panic!("We should not get StopSending.");
+                }
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    assert_eq!(error, Error::HttpRequestCancelled.code());
+                    assert!(!local);
+                    reset = true;
+                }
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not get any headers or data");
+                }
+                _ => {}
+            }
+        }
+
+        assert!(reset);
+
+        // after this stream will be removed from client. We will check this by trying to read
+        // from the stream and that should fail.
+        let mut buf = [0_u8; 100];
+        let res = client.read_data(now(), request_stream_id, &mut buf);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        client.close(now(), 0, "");
+    }
+
+    fn test_incomplet_frame(buf: &[u8], error: &Error) {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            buf,
+            true,
+        );
+
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::DataReadable { stream_id } = e {
+                assert_eq!(stream_id, request_stream_id);
+                let mut buf_res = [0_u8; 100];
+                let res = client.read_data(now(), stream_id, &mut buf_res);
+                assert!(res.is_err());
+                assert_eq!(res.unwrap_err(), Error::HttpFrame);
+            }
+        }
+        assert_closed(&client, error);
+    }
+
+    // Incomplete DATA frame
+    #[test]
+    fn test_incomplet_data_frame() {
+        test_incomplet_frame(&HTTP_RESPONSE_2[..12], &Error::HttpFrame);
+    }
+
+    // Incomplete HEADERS frame
+    #[test]
+    fn test_incomplet_headers_frame() {
+        test_incomplet_frame(&HTTP_RESPONSE_2[..7], &Error::HttpFrame);
+    }
+
+    #[test]
+    fn test_incomplet_unknown_frame() {
+        test_incomplet_frame(&[0x21], &Error::HttpFrame);
+    }
+
+    // test goaway
+    #[test]
+    fn test_goaway() {
+        let (mut client, mut server) = connect();
+        let request_stream_id_1 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_1, 0);
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+        let request_stream_id_3 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_3, 8);
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x8])
+            .unwrap();
+
+        // find the new request/response stream and send frame v on it.
+        while let Some(e) = server.conn.next_event() {
+            if let ConnectionEvent::RecvStreamReadable { stream_id } = e {
+                let mut buf = [0_u8; 100];
+                _ = server.conn.stream_recv(stream_id, &mut buf).unwrap();
+                if (stream_id == request_stream_id_1) || (stream_id == request_stream_id_2) {
+                    // send response - 200  Content-Length: 7
+                    // with content: 'abcdefg'.
+                    // The content will be send in 2 DATA frames.
+                    _ = server.conn.stream_send(stream_id, HTTP_RESPONSE_1).unwrap();
+                    server.conn.stream_close_send(stream_id).unwrap();
+                }
+            }
+        }
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let mut stream_reset = false;
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady { headers, fin, .. } => {
+                    check_response_header_1(&headers);
+                    assert!(!fin);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert!(
+                        (stream_id == request_stream_id_1) || (stream_id == request_stream_id_2)
+                    );
+                    let mut buf = [0_u8; 100];
+                    assert_eq!(
+                        (EXPECTED_RESPONSE_DATA_1.len(), true),
+                        client.read_data(now(), stream_id, &mut buf).unwrap()
+                    );
+                }
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert_eq!(stream_id, request_stream_id_3);
+                    assert_eq!(error, Error::HttpRequestRejected.code());
+                    assert!(!local);
+                    stream_reset = true;
+                }
+                _ => {}
+            }
+        }
+
+        assert!(stream_reset);
+        assert_eq!(client.state(), Http3State::GoingAway(StreamId::new(8)));
+
+        // Check that a new request cannot be made.
+        assert_eq!(
+            client.fetch(
+                now(),
+                "GET",
+                &("https", "something.com", "/"),
+                &[],
+                Priority::default()
+            ),
+            Err(Error::AlreadyClosed)
+        );
+
+        client.close(now(), 0, "");
+    }
+
+    #[test]
+    fn multiple_goaways() {
+        let (mut client, mut server) = connect();
+        let request_stream_id_1 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_1, 0);
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+        let request_stream_id_3 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_3, 8);
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // First send a Goaway frame with an higher number
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x8])
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Check that there is one reset for stream_id 8
+        let mut stream_reset_1 = 0;
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::Reset {
+                stream_id,
+                error,
+                local,
+            } = e
+            {
+                assert_eq!(stream_id, request_stream_id_3);
+                assert_eq!(error, Error::HttpRequestRejected.code());
+                assert!(!local);
+                stream_reset_1 += 1;
+            }
+        }
+
+        assert_eq!(stream_reset_1, 1);
+        assert_eq!(client.state(), Http3State::GoingAway(StreamId::new(8)));
+
+        // Server sends another GOAWAY frame
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x4])
+            .unwrap();
+
+        // Send response for stream 0
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id_1,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        let mut stream_reset_2 = 0;
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady { headers, fin, .. } => {
+                    check_response_header_1(&headers);
+                    assert!(!fin);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert!(stream_id == request_stream_id_1);
+                    let mut buf = [0_u8; 100];
+                    assert_eq!(
+                        (EXPECTED_RESPONSE_DATA_1.len(), true),
+                        client.read_data(now(), stream_id, &mut buf).unwrap()
+                    );
+                }
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert_eq!(stream_id, request_stream_id_2);
+                    assert_eq!(error, Error::HttpRequestRejected.code());
+                    assert!(!local);
+                    stream_reset_2 += 1;
+                }
+                _ => {}
+            }
+        }
+
+        assert_eq!(stream_reset_2, 1);
+        assert_eq!(client.state(), Http3State::GoingAway(StreamId::new(4)));
+    }
+
+    #[test]
+    fn multiple_goaways_stream_id_increased() {
+        let (mut client, mut server) = connect();
+        let request_stream_id_1 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_1, 0);
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+        let request_stream_id_3 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_3, 8);
+
+        // First send a Goaway frame with a smaller number
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x4])
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_eq!(client.state(), Http3State::GoingAway(StreamId::new(4)));
+
+        // Now send a Goaway frame with an higher number
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x8])
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_closed(&client, &Error::HttpGeneralProtocol);
+    }
+
+    #[test]
+    fn goaway_wrong_stream_id() {
+        let (mut client, mut server) = connect();
+
+        _ = server
+            .conn
+            .stream_send(server.control_stream_id.unwrap(), &[0x7, 0x1, 0x9])
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    // Close stream before headers.
+    #[test]
+    fn test_stream_fin_wo_headers() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        // send fin before sending any data.
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Recv HeaderReady wo headers with fin.
+        let e = client.events().next().unwrap();
+        assert_eq!(
+            e,
+            Http3ClientEvent::Reset {
+                stream_id: request_stream_id,
+                error: Error::HttpGeneralProtocolStream.code(),
+                local: true,
+            }
+        );
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    // Close stream imemediately after headers.
+    #[test]
+    fn test_stream_fin_after_headers() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_HEADER_ONLY_2,
+            true,
+        );
+
+        // Recv HeaderReady with headers and fin.
+        let e = client.events().next().unwrap();
+        if let Http3ClientEvent::HeaderReady {
+            stream_id,
+            headers,
+            interim,
+            fin,
+        } = e
+        {
+            assert_eq!(stream_id, request_stream_id);
+            check_response_header_2(&headers);
+            assert!(fin);
+            assert!(!interim);
+        } else {
+            panic!("wrong event type");
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    // Send headers, read headers and than close stream.
+    // We should get HeaderReady and a DataReadable
+    #[test]
+    fn test_stream_fin_after_headers_are_read_wo_data_frame() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        // Send some good data wo fin
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_HEADER_ONLY_2,
+            false,
+        );
+
+        // Recv headers wo fin
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not receive a DataGeadable event!");
+                }
+                _ => {}
+            };
+        }
+
+        // ok NOW send fin
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Recv DataReadable wo data with fin
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady { .. } => {
+                    panic!("We should not get another HeaderReady!");
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let res = client.read_data(now(), stream_id, &mut buf);
+                    let (len, fin) = res.expect("should read");
+                    assert_eq!(0, len);
+                    assert!(fin);
+                }
+                _ => {}
+            };
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    // Send headers and an empty data frame, then close the stream.
+    #[test]
+    fn test_stream_fin_after_headers_and_a_empty_data_frame() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send headers.
+        _ = server
+            .conn
+            .stream_send(request_stream_id, HTTP_RESPONSE_HEADER_ONLY_2)
+            .unwrap();
+        // Send an empty data frame.
+        _ = server
+            .conn
+            .stream_send(request_stream_id, &[0x00, 0x00])
+            .unwrap();
+        // ok NOW send fin
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Recv HeaderReady with fin.
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    assert_eq!(Ok((0, true)), client.read_data(now(), stream_id, &mut buf));
+                }
+                _ => {}
+            };
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), request_stream_id, &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    // Send headers and an empty data frame. Read headers and then close the stream.
+    // We should get a HeaderReady without fin and a DataReadable wo data and with fin.
+    #[test]
+    fn test_stream_fin_after_headers_an_empty_data_frame_are_read() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        // Send some good data wo fin
+        // Send headers.
+        _ = server
+            .conn
+            .stream_send(request_stream_id, HTTP_RESPONSE_HEADER_ONLY_2)
+            .unwrap();
+        // Send an empty data frame.
+        _ = server
+            .conn
+            .stream_send(request_stream_id, &[0x00, 0x00])
+            .unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Recv headers wo fin
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { .. } => {
+                    panic!("We should not receive a DataGeadable event!");
+                }
+                _ => {}
+            };
+        }
+
+        // ok NOW send fin
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Recv no data, but do get fin
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady { .. } => {
+                    panic!("We should not get another HeaderReady!");
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let res = client.read_data(now(), stream_id, &mut buf);
+                    let (len, fin) = res.expect("should read");
+                    assert_eq!(0, len);
+                    assert!(fin);
+                }
+                _ => {}
+            };
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    #[test]
+    fn test_stream_fin_after_a_data_frame() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        // Send some good data wo fin
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            false,
+        );
+
+        // Recv some good data wo fin
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady {
+                    stream_id,
+                    headers,
+                    interim,
+                    fin,
+                } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    check_response_header_2(&headers);
+                    assert!(!fin);
+                    assert!(!interim);
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    let mut buf = [0_u8; 100];
+                    let res = client.read_data(now(), stream_id, &mut buf);
+                    let (len, fin) = res.expect("should have data");
+                    assert_eq!(len, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+                    assert_eq!(&buf[..len], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+                    assert!(!fin);
+                }
+                _ => {}
+            };
+        }
+
+        // ok NOW send fin
+        server.conn.stream_close_send(request_stream_id).unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // fin wo data should generate DataReadable
+        let e = client.events().next().unwrap();
+        if let Http3ClientEvent::DataReadable { stream_id } = e {
+            assert_eq!(stream_id, request_stream_id);
+            let mut buf = [0; 100];
+            let res = client.read_data(now(), stream_id, &mut buf);
+            let (len, fin) = res.expect("should read");
+            assert_eq!(0, len);
+            assert!(fin);
+        } else {
+            panic!("wrong event type");
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    #[test]
+    fn test_multiple_data_frames() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send two data frames with fin
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        // Read first frame
+        match client.events().nth(1).unwrap() {
+            Http3ClientEvent::DataReadable { stream_id } => {
+                assert_eq!(stream_id, request_stream_id);
+                let mut buf = [0_u8; 100];
+                assert_eq!(
+                    (EXPECTED_RESPONSE_DATA_1.len(), true),
+                    client.read_data(now(), stream_id, &mut buf).unwrap()
+                );
+            }
+            x => {
+                panic!("event {:?}", x);
+            }
+        }
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    #[test]
+    fn test_receive_grease_before_response() {
+        // Construct an unknown frame.
+        const UNKNOWN_FRAME_LEN: usize = 832;
+
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        let mut enc = Encoder::with_capacity(UNKNOWN_FRAME_LEN + 4);
+        enc.encode_varint(1028_u64); // Arbitrary type.
+        enc.encode_varint(UNKNOWN_FRAME_LEN as u64);
+        let mut buf: Vec<_> = enc.into();
+        buf.resize(UNKNOWN_FRAME_LEN + buf.len(), 0);
+        _ = server.conn.stream_send(request_stream_id, &buf).unwrap();
+
+        // Send a headers and a data frame with fin
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        // Read first frame
+        match client.events().nth(1).unwrap() {
+            Http3ClientEvent::DataReadable { stream_id } => {
+                assert_eq!(stream_id, request_stream_id);
+                let mut buf = [0_u8; 100];
+                let (len, fin) = client.read_data(now(), stream_id, &mut buf).unwrap();
+                assert_eq!(len, EXPECTED_RESPONSE_DATA_2_FRAME_1.len());
+                assert_eq!(&buf[..len], EXPECTED_RESPONSE_DATA_2_FRAME_1);
+                assert!(fin);
+            }
+            x => {
+                panic!("event {:?}", x);
+            }
+        }
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    #[test]
+    fn test_read_frames_header_blocked() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions, but delay them so that the stream is blocked on decoding
+        // headers.
+        let encoder_inst_pkt = server.conn.process(None, now());
+
+        // Send response
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data { len: 3 };
+        d_frame.encode(&mut d);
+        d.encode(&[0x61, 0x62, 0x63]);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!client.events().any(header_ready_event));
+
+        // Let client receive the encoder instructions.
+        mem::drop(client.process(encoder_inst_pkt.as_dgram_ref(), now()));
+
+        let out = server.conn.process(None, now());
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+        mem::drop(client.process(None, now()));
+
+        let mut recv_header = false;
+        let mut recv_data = false;
+        // Now the stream is unblocked and both headers and data will be consumed.
+        while let Some(e) = client.next_event() {
+            match e {
+                Http3ClientEvent::HeaderReady { stream_id, .. } => {
+                    assert_eq!(stream_id, request_stream_id);
+                    recv_header = true;
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    recv_data = true;
+                    assert_eq!(stream_id, request_stream_id);
+                }
+                x => {
+                    panic!("event {:?}", x);
+                }
+            }
+        }
+        assert!(recv_header && recv_data);
+    }
+
+    #[test]
+    fn test_read_frames_header_blocked_with_fin_after_headers() {
+        let (mut hconn, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut hconn, &mut server);
+
+        let sent_headers = vec![
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "0"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &sent_headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions, but delay them so that the stream is blocked on decoding
+        // headers.
+        let encoder_inst_pkt = server.conn.process(None, now());
+
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+
+        server_send_response_and_exchange_packet(
+            &mut hconn,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!hconn.events().any(header_ready_event));
+
+        // Let client receive the encoder instructions.
+        let _out = hconn.process(encoder_inst_pkt.as_dgram_ref(), now());
+
+        let mut recv_header = false;
+        // Now the stream is unblocked. After headers we will receive a fin.
+        while let Some(e) = hconn.next_event() {
+            if let Http3ClientEvent::HeaderReady {
+                stream_id,
+                headers,
+                interim,
+                fin,
+            } = e
+            {
+                assert_eq!(stream_id, request_stream_id);
+                assert_eq!(headers.as_ref(), sent_headers);
+                assert!(fin);
+                assert!(!interim);
+                recv_header = true;
+            } else {
+                panic!("event {:?}", e);
+            }
+        }
+        assert!(recv_header);
+    }
+
+    fn exchange_token(client: &mut Http3Client, server: &mut Connection) -> ResumptionToken {
+        server.send_ticket(now(), &[]).expect("can send ticket");
+        let out = server.process_output(now());
+        assert!(out.as_dgram_ref().is_some());
+        client.process_input(out.as_dgram_ref().unwrap(), now());
+        // We do not have a token so we need to wait for a resumption token timer to trigger.
+        client.process_output(now() + Duration::from_millis(250));
+        assert_eq!(client.state(), Http3State::Connected);
+        client
+            .events()
+            .find_map(|e| {
+                if let Http3ClientEvent::ResumptionToken(token) = e {
+                    Some(token)
+                } else {
+                    None
+                }
+            })
+            .unwrap()
+    }
+
+    fn start_with_0rtt() -> (Http3Client, TestServer) {
+        let (mut client, mut server) = connect();
+        let token = exchange_token(&mut client, &mut server.conn);
+
+        let mut client = default_http3_client();
+
+        let server = TestServer::new();
+
+        assert_eq!(client.state(), Http3State::Initializing);
+        client
+            .enable_resumption(now(), &token)
+            .expect("Set resumption token.");
+
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        let zerortt_event = |e| matches!(e, Http3ClientEvent::StateChange(Http3State::ZeroRtt));
+        assert!(client.events().any(zerortt_event));
+
+        (client, server)
+    }
+
+    #[test]
+    fn zero_rtt_negotiated() {
+        let (mut client, mut server) = start_with_0rtt();
+
+        let out = client.process(None, now());
+
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        assert_eq!(*server.conn.state(), State::Init);
+        let out = server.conn.process(out.as_dgram_ref(), now());
+
+        // Check that control and qpack streams are received and a
+        // SETTINGS frame has been received.
+        // Also qpack encoder stream will send "change capacity" instruction because it has
+        // the peer settings already.
+        server.check_control_qpack_request_streams_resumption(
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+            EXPECTED_REQUEST_HEADER_FRAME,
+            false,
+        );
+
+        assert_eq!(*server.conn.state(), State::Handshaking);
+        let out = client.process(out.as_dgram_ref(), now());
+        assert_eq!(client.state(), Http3State::Connected);
+
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        assert!(server.conn.state().connected());
+
+        assert!(client.tls_info().unwrap().resumed());
+        assert!(server.conn.tls_info().unwrap().resumed());
+    }
+
+    #[test]
+    fn zero_rtt_send_request() {
+        let (mut client, mut server) = start_with_0rtt();
+
+        let request_stream_id =
+            make_request(&mut client, true, &[Header::new("myheaders", "myvalue")]);
+        assert_eq!(request_stream_id, 0);
+
+        let out = client.process(None, now());
+
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        assert_eq!(*server.conn.state(), State::Init);
+        let out = server.conn.process(out.as_dgram_ref(), now());
+
+        // Check that control and qpack streams are received and a
+        // SETTINGS frame has been received.
+        // Also qpack encoder stream will send "change capacity" instruction because it has
+        // the peer settings already.
+        server.check_control_qpack_request_streams_resumption(
+            ENCODER_STREAM_DATA_WITH_CAP_INST_AND_ENCODING_INST,
+            EXPECTED_REQUEST_HEADER_FRAME_VERSION2,
+            true,
+        );
+
+        assert_eq!(*server.conn.state(), State::Handshaking);
+        let out = client.process(out.as_dgram_ref(), now());
+        assert_eq!(client.state(), Http3State::Connected);
+        let out = server.conn.process(out.as_dgram_ref(), now());
+        assert!(server.conn.state().connected());
+        let out = client.process(out.as_dgram_ref(), now());
+        assert!(out.as_dgram_ref().is_none());
+
+        // After the server has been connected, send a response.
+        let res = server.conn.stream_send(request_stream_id, HTTP_RESPONSE_2);
+        assert_eq!(res, Ok(HTTP_RESPONSE_2.len()));
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        read_response(&mut client, &mut server.conn, request_stream_id);
+
+        assert!(client.tls_info().unwrap().resumed());
+        assert!(server.conn.tls_info().unwrap().resumed());
+    }
+
+    #[test]
+    fn zero_rtt_before_resumption_token() {
+        let mut client = default_http3_client();
+        assert!(client
+            .fetch(
+                now(),
+                "GET",
+                &("https", "something.com", "/"),
+                &[],
+                Priority::default()
+            )
+            .is_err());
+    }
+
+    #[test]
+    fn zero_rtt_send_reject() {
+        let (mut client, mut server) = connect();
+        let token = exchange_token(&mut client, &mut server.conn);
+
+        let mut client = default_http3_client();
+        let mut server = Connection::new_server(
+            test_fixture::DEFAULT_KEYS,
+            test_fixture::DEFAULT_ALPN_H3,
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            ConnectionParameters::default(),
+        )
+        .unwrap();
+        // Using a freshly initialized anti-replay context
+        // should result in the server rejecting 0-RTT.
+        let ar = AntiReplay::new(now(), test_fixture::ANTI_REPLAY_WINDOW, 1, 3)
+            .expect("setup anti-replay");
+        server
+            .server_enable_0rtt(&ar, AllowZeroRtt {})
+            .expect("enable 0-RTT");
+
+        assert_eq!(client.state(), Http3State::Initializing);
+        client
+            .enable_resumption(now(), &token)
+            .expect("Set resumption token.");
+        let zerortt_event = |e| matches!(e, Http3ClientEvent::StateChange(Http3State::ZeroRtt));
+        assert!(client.events().any(zerortt_event));
+
+        // Send ClientHello.
+        let client_hs = client.process(None, now());
+        assert!(client_hs.as_dgram_ref().is_some());
+
+        // Create a request
+        let request_stream_id = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id, 0);
+
+        let client_0rtt = client.process(None, now());
+        assert!(client_0rtt.as_dgram_ref().is_some());
+
+        let server_hs = server.process(client_hs.as_dgram_ref(), now());
+        assert!(server_hs.as_dgram_ref().is_some()); // Should produce ServerHello etc...
+        let server_ignored = server.process(client_0rtt.as_dgram_ref(), now());
+        assert!(server_ignored.as_dgram_ref().is_none());
+
+        // The server shouldn't receive that 0-RTT data.
+        let recvd_stream_evt = |e| matches!(e, ConnectionEvent::NewStream { .. });
+        assert!(!server.events().any(recvd_stream_evt));
+
+        // Client should get a rejection.
+        let client_out = client.process(server_hs.as_dgram_ref(), now());
+        assert!(client_out.as_dgram_ref().is_some());
+        let recvd_0rtt_reject = |e| e == Http3ClientEvent::ZeroRttRejected;
+        assert!(client.events().any(recvd_0rtt_reject));
+
+        // ...and the client stream should be gone.
+        let res = client.stream_close_send(request_stream_id);
+        assert!(res.is_err());
+        assert_eq!(res.unwrap_err(), Error::InvalidStreamId);
+
+        // Client will send Setting frame and open new qpack streams.
+        mem::drop(server.process(client_out.as_dgram_ref(), now()));
+        TestServer::new_with_conn(server).check_client_control_qpack_streams_no_resumption();
+
+        // Check that we can send a request and that the stream_id starts again from 0.
+        assert_eq!(make_request(&mut client, false, &[]), 0);
+    }
+
+    // Connect to a server, get token and reconnect using 0-rtt. Seerver sends new Settings.
+    fn zero_rtt_change_settings(
+        original_settings: &[HSetting],
+        resumption_settings: &[HSetting],
+        expected_client_state: &Http3State,
+        expected_encoder_stream_data: &[u8],
+    ) {
+        let mut client = default_http3_client();
+        let mut server = TestServer::new_with_settings(original_settings);
+        // Connect and get a token
+        connect_with(&mut client, &mut server);
+        let token = exchange_token(&mut client, &mut server.conn);
+
+        let mut client = default_http3_client();
+        let mut server = TestServer::new_with_settings(resumption_settings);
+        assert_eq!(client.state(), Http3State::Initializing);
+        client
+            .enable_resumption(now(), &token)
+            .expect("Set resumption token.");
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        let out = client.process(None, now());
+
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        assert_eq!(*server.conn.state(), State::Init);
+        let out = server.conn.process(out.as_dgram_ref(), now());
+
+        // Check that control and qpack streams anda SETTINGS frame are received.
+        // Also qpack encoder stream will send "change capacity" instruction because it has
+        // the peer settings already.
+        server.check_control_qpack_request_streams_resumption(
+            expected_encoder_stream_data,
+            EXPECTED_REQUEST_HEADER_FRAME,
+            false,
+        );
+
+        assert_eq!(*server.conn.state(), State::Handshaking);
+        let out = client.process(out.as_dgram_ref(), now());
+        assert_eq!(client.state(), Http3State::Connected);
+
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        assert!(server.conn.state().connected());
+
+        assert!(client.tls_info().unwrap().resumed());
+        assert!(server.conn.tls_info().unwrap().resumed());
+
+        // Send new settings.
+        let control_stream = server.conn.stream_create(StreamType::UniDi).unwrap();
+        let mut enc = Encoder::default();
+        server.settings.encode(&mut enc);
+        let mut sent = server.conn.stream_send(control_stream, CONTROL_STREAM_TYPE);
+        assert_eq!(sent.unwrap(), CONTROL_STREAM_TYPE.len());
+        sent = server.conn.stream_send(control_stream, enc.as_ref());
+        assert_eq!(sent.unwrap(), enc.len());
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        assert_eq!(&client.state(), expected_client_state);
+        assert!(server.conn.state().connected());
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_are_the_same() {
+        // Send a new server settings that are the same as the old one.
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_omit_max_table() {
+        // Send a new server settings without MaxTableCapacity
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_omit_blocked_streams() {
+        // Send a new server settings without BlockedStreams
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_omit_header_list_size() {
+        // Send a new server settings without MaxHeaderListSize
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_max_table_size_bigger() {
+        // Send a new server settings MaxTableCapacity=200
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 200),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(514)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_max_table_size_smaller() {
+        // Send a new server settings MaxTableCapacity=50
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 50),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_blocked_streams_bigger() {
+        // Send a new server settings withBlockedStreams=200
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 200),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_blocked_streams_smaller() {
+        // Send a new server settings withBlockedStreams=50
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 50),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_max_header_size_bigger() {
+        // Send a new server settings with MaxHeaderListSize=20000
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 20000),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_new_server_setting_max_headers_size_smaller() {
+        // Send the new server settings with MaxHeaderListSize=5000
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 5000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_max_table_size_first_omitted() {
+        // send server original settings without MaxTableCapacity
+        // send new server setting with MaxTableCapacity
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_blocked_streams_first_omitted() {
+        // Send server original settings without BlockedStreams
+        // Send the new server settings with BlockedStreams
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Connected,
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn zero_rtt_max_header_size_first_omitted() {
+        // Send server settings without MaxHeaderListSize
+        // Send new settings with MaxHeaderListSize.
+        zero_rtt_change_settings(
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 10000),
+            ],
+            &[
+                HSetting::new(HSettingType::MaxTableCapacity, 100),
+                HSetting::new(HSettingType::BlockedStreams, 100),
+                HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+            ],
+            &Http3State::Closing(ConnectionError::Application(265)),
+            ENCODER_STREAM_DATA_WITH_CAP_INSTRUCTION,
+        );
+    }
+
+    #[test]
+    fn test_trailers_with_fin_after_headers() {
+        // Make a new connection.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send HEADER frame.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            false,
+        );
+
+        // Check response headers.
+        let mut response_headers = false;
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::HeaderReady {
+                stream_id,
+                headers,
+                interim,
+                fin,
+            } = e
+            {
+                assert_eq!(stream_id, request_stream_id);
+                check_response_header_0(&headers);
+                assert!(!fin);
+                assert!(!interim);
+                response_headers = true;
+            }
+        }
+        assert!(response_headers);
+
+        // Send trailers
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            true,
+        );
+
+        let events: Vec<Http3ClientEvent> = client.events().collect();
+
+        // We already had HeaderReady
+        let header_ready: fn(&Http3ClientEvent) -> _ =
+            |e| matches!(*e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!events.iter().any(header_ready));
+
+        // Check that we have a DataReady event. Reading from the stream will return fin=true.
+        let data_readable: fn(&Http3ClientEvent) -> _ =
+            |e| matches!(*e, Http3ClientEvent::DataReadable { .. });
+        assert!(events.iter().any(data_readable));
+        let mut buf = [0_u8; 100];
+        let (len, fin) = client
+            .read_data(now(), request_stream_id, &mut buf)
+            .unwrap();
+        assert_eq!(0, len);
+        assert!(fin);
+    }
+
+    #[test]
+    fn test_trailers_with_later_fin_after_headers() {
+        // Make a new connection.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send HEADER frame.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            false,
+        );
+
+        // Check response headers.
+        let mut response_headers = false;
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::HeaderReady {
+                stream_id,
+                headers,
+                interim,
+                fin,
+            } = e
+            {
+                assert_eq!(stream_id, request_stream_id);
+                check_response_header_0(&headers);
+                assert!(!fin);
+                assert!(!interim);
+                response_headers = true;
+            }
+        }
+        assert!(response_headers);
+
+        // Send trailers
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            false,
+        );
+
+        // Check that we do not have a DataReady event.
+        let data_readable = |e| matches!(e, Http3ClientEvent::DataReadable { .. });
+        assert!(!client.events().any(data_readable));
+
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        let events: Vec<Http3ClientEvent> = client.events().collect();
+
+        // We already had HeaderReady
+        let header_ready: fn(&Http3ClientEvent) -> _ =
+            |e| matches!(*e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!events.iter().any(header_ready));
+
+        // Check that we have a DataReady event. Reading from the stream will return fin=true.
+        let data_readable_fn: fn(&Http3ClientEvent) -> _ =
+            |e| matches!(*e, Http3ClientEvent::DataReadable { .. });
+        assert!(events.iter().any(data_readable_fn));
+        let mut buf = [0_u8; 100];
+        let (len, fin) = client
+            .read_data(now(), request_stream_id, &mut buf)
+            .unwrap();
+        assert_eq!(0, len);
+        assert!(fin);
+    }
+
+    #[test]
+    fn test_data_after_trailers_after_headers() {
+        // Make a new connection.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send HEADER frame.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            false,
+        );
+
+        // Check response headers.
+        let mut response_headers = false;
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::HeaderReady {
+                stream_id,
+                headers,
+                interim,
+                fin,
+            } = e
+            {
+                assert_eq!(stream_id, request_stream_id);
+                check_response_header_0(&headers);
+                assert!(!fin);
+                assert!(!interim);
+                response_headers = true;
+            }
+        }
+        assert!(response_headers);
+
+        // Send trailers
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_HEADER_FRAME_0,
+            false,
+        );
+
+        // Check that we do not have a DataReady event.
+        let data_readable = |e| matches!(e, Http3ClientEvent::DataReadable { .. });
+        assert!(!client.events().any(data_readable));
+
+        // Send Data frame.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            [0x0, 0x3, 0x61, 0x62, 0x63], // a data frame
+            false,
+        );
+
+        assert_closed(&client, &Error::HttpFrameUnexpected);
+    }
+
+    #[test]
+    fn transport_stream_readable_event_after_all_data() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(false);
+
+        // Send headers.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            false,
+        );
+
+        // Send an empty data frame and a fin
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            [0x0, 0x0],
+            true,
+        );
+
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Ok((3, true))
+        );
+
+        client.process(None, now());
+    }
+
+    #[test]
+    fn no_data_ready_events_after_fin() {
+        // Connect exchange headers and send a request. Also check if the correct header frame has
+        // been sent.
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // send response - 200  Content-Length: 7
+        // with content: 'abcdefg'.
+        // The content will be send in 2 DATA frames.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        let data_readable_event = |e| matches!(e, Http3ClientEvent::DataReadable { stream_id } if stream_id == request_stream_id);
+        assert!(client.events().any(data_readable_event));
+
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            (EXPECTED_RESPONSE_DATA_1.len(), true),
+            client
+                .read_data(now(), request_stream_id, &mut buf)
+                .unwrap()
+        );
+
+        assert!(!client.events().any(data_readable_event));
+    }
+
+    #[test]
+    fn reading_small_chunks_of_data() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // send response - 200  Content-Length: 7
+        // with content: 'abcdefg'.
+        // The content will be send in 2 DATA frames.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        let data_readable_event = |e| matches!(e, Http3ClientEvent::DataReadable { stream_id } if stream_id == request_stream_id);
+        assert!(client.events().any(data_readable_event));
+
+        let mut buf1 = [0_u8; 1];
+        assert_eq!(
+            (1, false),
+            client
+                .read_data(now(), request_stream_id, &mut buf1)
+                .unwrap()
+        );
+        assert!(!client.events().any(data_readable_event));
+
+        // Now read only until the end of the first frame. The firs framee has 3 bytes.
+        let mut buf2 = [0_u8; 2];
+        assert_eq!(
+            (2, false),
+            client
+                .read_data(now(), request_stream_id, &mut buf2)
+                .unwrap()
+        );
+        assert!(!client.events().any(data_readable_event));
+
+        // Read a half of the second frame.
+        assert_eq!(
+            (2, false),
+            client
+                .read_data(now(), request_stream_id, &mut buf2)
+                .unwrap()
+        );
+        assert!(!client.events().any(data_readable_event));
+
+        // Read the rest.
+        // Read a half of the second frame.
+        assert_eq!(
+            (2, true),
+            client
+                .read_data(now(), request_stream_id, &mut buf2)
+                .unwrap()
+        );
+        assert!(!client.events().any(data_readable_event));
+    }
+
+    #[test]
+    fn zero_length_data_at_end() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // send response - 200  Content-Length: 7
+        // with content: 'abcdefg'.
+        // The content will be send in 2 DATA frames.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            false,
+        );
+        // Send a zero-length frame at the end of the stream.
+        _ = server.conn.stream_send(request_stream_id, &[0, 0]).unwrap();
+        server.conn.stream_close_send(request_stream_id).unwrap();
+        let dgram = server.conn.process_output(now()).dgram();
+        client.process_input(&dgram.unwrap(), now());
+
+        let data_readable_event = |e: &_| matches!(e, Http3ClientEvent::DataReadable { stream_id } if *stream_id == request_stream_id);
+        assert_eq!(client.events().filter(data_readable_event).count(), 1);
+
+        let mut buf = [0_u8; 10];
+        assert_eq!(
+            (7, true),
+            client
+                .read_data(now(), request_stream_id, &mut buf)
+                .unwrap()
+        );
+        assert!(!client.events().any(|e| data_readable_event(&e)));
+    }
+
+    #[test]
+    fn stream_blocked_no_remote_encoder_stream() {
+        let (mut client, mut server) = connect_only_transport();
+
+        send_and_receive_client_settings(&mut client, &mut server);
+
+        server.create_control_stream();
+        // Send the server's control stream data.
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        server.create_qpack_streams();
+        let qpack_pkt1 = server.conn.process(None, now());
+        // delay delivery of this packet.
+
+        let request_stream_id = make_request(&mut client, true, &[]);
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions,
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Send response
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data { len: 3 };
+        d_frame.encode(&mut d);
+        d.encode(&[0x61, 0x62, 0x63]);
+        _ = server
+            .conn
+            .stream_send(request_stream_id, d.as_ref())
+            .unwrap();
+        server.conn.stream_close_send(request_stream_id).unwrap();
+
+        let out = server.conn.process(None, now());
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!client.events().any(header_ready_event));
+
+        // Let client receive the encoder instructions.
+        mem::drop(client.process(qpack_pkt1.as_dgram_ref(), now()));
+
+        assert!(client.events().any(header_ready_event));
+    }
+
+    // Client: receive a push stream
+    #[test]
+    fn push_single() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+
+        // create a push stream.
+        _ = send_push_data(&mut server.conn, 0, true);
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 0,
+                ref_stream_id: request_stream_id,
+            }],
+            &[0],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+    }
+
+    /// We can't keep the connection alive on the basis of a push promise,
+    /// nor do we want to if the push promise is not interesting to the client.
+    /// We do the next best thing, which is keep any push stream alive if the
+    /// client reads from it.
+    #[test]
+    fn push_keep_alive() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        let idle_timeout = ConnectionParameters::default().get_idle_timeout();
+
+        // Promise a push and deliver, but don't close the stream.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 0,
+                ref_stream_id: request_stream_id,
+            }],
+            &[], // No push streams yet.
+            request_stream_id,
+        );
+
+        // The client will become idle here.
+        force_idle(&mut client, &mut server);
+        assert_eq!(client.process_output(now()).callback(), idle_timeout);
+
+        // Reading push data will stop the client from being idle.
+        _ = send_push_data(&mut server.conn, 0, false);
+        let out = server.conn.process_output(now());
+        client.process_input(out.as_dgram_ref().unwrap(), now());
+
+        let mut buf = [0; 16];
+        let (read, fin) = client.push_read_data(now(), 0, &mut buf).unwrap();
+        assert!(read < buf.len());
+        assert!(!fin);
+
+        force_idle(&mut client, &mut server);
+        assert_eq!(client.process_output(now()).callback(), idle_timeout / 2);
+    }
+
+    #[test]
+    fn push_multiple() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        send_push_promise(&mut server.conn, request_stream_id, 1);
+
+        // create a push stream.
+        _ = send_push_data(&mut server.conn, 0, true);
+
+        // create a second push stream.
+        _ = send_push_data(&mut server.conn, 1, true);
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 0,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 1,
+                    ref_stream_id: request_stream_id,
+                },
+            ],
+            &[0, 1],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+        assert_eq!(client.cancel_push(1), Err(Error::InvalidStreamId));
+    }
+
+    #[test]
+    fn push_after_headers() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send response headers
+        _ = server
+            .conn
+            .stream_send(request_stream_id, HTTP_RESPONSE_HEADER_ONLY_2)
+            .unwrap();
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+
+        // create a push stream.
+        _ = send_push_data(&mut server.conn, 0, true);
+
+        // Send response data
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_DATA_FRAME_ONLY_2,
+            true,
+        );
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 0,
+                ref_stream_id: request_stream_id,
+            }],
+            &[0],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    #[test]
+    fn push_after_response() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send response headers and data frames
+        _ = server
+            .conn
+            .stream_send(request_stream_id, HTTP_RESPONSE_2)
+            .unwrap();
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        // create a push stream.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 0,
+                ref_stream_id: request_stream_id,
+            }],
+            &[0],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    fn check_push_events(client: &mut Http3Client) -> bool {
+        let any_push_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::PushPromise { .. }
+                    | Http3ClientEvent::PushHeaderReady { .. }
+                    | Http3ClientEvent::PushDataReadable { .. }
+            )
+        };
+        client.events().any(any_push_event)
+    }
+
+    fn check_data_readable(client: &mut Http3Client) -> bool {
+        let any_data_event = |e| matches!(e, Http3ClientEvent::DataReadable { .. });
+        client.events().any(any_data_event)
+    }
+
+    fn check_header_ready(client: &mut Http3Client) -> bool {
+        let any_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        client.events().any(any_event)
+    }
+
+    fn check_header_ready_and_push_promise(client: &mut Http3Client) -> bool {
+        let any_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::HeaderReady { .. } | Http3ClientEvent::PushPromise { .. }
+            )
+        };
+        client.events().any(any_event)
+    }
+
+    #[test]
+    fn push_stream_before_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // create a push stream.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Now send push_promise
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 0,
+                ref_stream_id: request_stream_id,
+            }],
+            &[0],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test receiving pushes out of order.
+    // Push_id 5 is received first, therefore Push_id 3 will be in the PushState:Init state.
+    // Start push_id 3 by receiving a push_promise and then a push stream with the push_id 3.
+    #[test]
+    fn push_out_of_order_1() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 3);
+        // Start a push stream with push_id 3.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 3, true);
+
+        assert_eq!(client.state(), Http3State::Connected);
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 3,
+                    ref_stream_id: request_stream_id,
+                },
+            ],
+            &[3],
+            request_stream_id,
+        );
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test receiving pushes out of order.
+    // Push_id 5 is received first, therefore Push_id 3 will be in the PushState:Init state.
+    // Start push_id 3 by receiving a push stream with push_id 3 and then a push_promise.
+    #[test]
+    fn push_out_of_order_2() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+
+        send_push_data_and_exchange_packets(&mut client, &mut server, 3, true);
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 3);
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 3,
+                    ref_stream_id: request_stream_id,
+                },
+            ],
+            &[3],
+            request_stream_id,
+        );
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test receiving pushes out of order.
+    // Push_id 5 is received first and read so that it is removed from the list,
+    // therefore Push_id 3 will be in the PushState:Init state.
+    // Start push_id 3 by receiving a push stream with the push_id 3 and then a push_promise.
+    #[test]
+    fn push_out_of_order_3() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+        send_push_data_and_exchange_packets(&mut client, &mut server, 5, true);
+        assert_eq!(client.state(), Http3State::Connected);
+
+        // Read push stream with push_id 5 to make it change to closed state.
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 5,
+                ref_stream_id: request_stream_id,
+            }],
+            &[5],
+            request_stream_id,
+        );
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 3);
+        send_push_data_and_exchange_packets(&mut client, &mut server, 3, true);
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 3,
+                ref_stream_id: request_stream_id,
+            }],
+            &[3],
+            request_stream_id,
+        );
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // The next test is for receiving a second PushPromise when Push is in the PushPromise state.
+    #[test]
+    fn multiple_push_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+
+        // make a second request.
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id_2, 5);
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id_2,
+                },
+            ],
+            &[],
+            request_stream_id,
+        );
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // The next test is for receiving a second PushPromise when Push is in the Active state.
+    #[test]
+    fn multiple_push_promise_active() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+        send_push_data_and_exchange_packets(&mut client, &mut server, 5, true);
+
+        // make a second request.
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id_2, 5);
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 5,
+                    ref_stream_id: request_stream_id_2,
+                },
+            ],
+            &[5],
+            request_stream_id,
+        );
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // The next test is for receiving a second PushPromise when the push is already closed.
+    // PushPromise will be ignored for the push streams that are consumed.
+    #[test]
+    fn multiple_push_promise_closed() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 5);
+        // Start a push stream with push_id 5.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 5, true);
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 5,
+                ref_stream_id: request_stream_id,
+            }],
+            &[5],
+            request_stream_id,
+        );
+
+        // make a second request.
+        let request_stream_id_2 = make_request(&mut client, false, &[]);
+        assert_eq!(request_stream_id_2, 4);
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id_2, 5);
+
+        // Check that we do not have a Http3ClientEvent::PushPromise.
+        let push_event = |e| matches!(e, Http3ClientEvent::PushPromise { .. });
+        assert!(!client.events().any(push_event));
+    }
+
+    // Test that max_push_id is enforced when a push promise frame is received.
+    #[test]
+    fn exceed_max_push_id_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send a push promise. max_push_id is set to 5, to trigger an error we send push_id=6.
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 6);
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    // Test that max_push_id is enforced when a push stream is received.
+    #[test]
+    fn exceed_max_push_id_push_stream() {
+        // Connect and send a request
+        let (mut client, mut server) = connect();
+
+        // Send a push stream. max_push_id is set to 5, to trigger an error we send push_id=6.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 6, true);
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    // Test that max_push_id is enforced when a cancel push frame is received.
+    #[test]
+    fn exceed_max_push_id_cancel_push() {
+        // Connect and send a request
+        let (mut client, mut server, _request_stream_id) = connect_and_send_request(true);
+
+        // Send CANCEL_PUSH for push_id 6.
+        send_cancel_push_and_exchange_packets(&mut client, &mut server, 6);
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    // Test that max_push_id is enforced when an app calls cancel_push.
+    #[test]
+    fn exceed_max_push_id_cancel_api() {
+        // Connect and send a request
+        let (mut client, _, _) = connect_and_send_request(true);
+
+        assert_eq!(client.cancel_push(6), Err(Error::HttpId));
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    #[test]
+    fn test_max_push_id_frame_update_is_sent() {
+        const MAX_PUSH_ID_FRAME: &[u8] = &[0xd, 0x1, 0x8];
+
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send 3 push promises.
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        send_push_promise(&mut server.conn, request_stream_id, 1);
+        send_push_promise(&mut server.conn, request_stream_id, 2);
+
+        // create 3 push streams.
+        send_push_data(&mut server.conn, 0, true);
+        send_push_data(&mut server.conn, 1, true);
+        send_push_data_and_exchange_packets(&mut client, &mut server, 2, true);
+
+        read_response_and_push_events(
+            &mut client,
+            &[
+                PushPromiseInfo {
+                    push_id: 0,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 1,
+                    ref_stream_id: request_stream_id,
+                },
+                PushPromiseInfo {
+                    push_id: 2,
+                    ref_stream_id: request_stream_id,
+                },
+            ],
+            &[0, 1, 2],
+            request_stream_id,
+        );
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // Check max_push_id frame has been received
+        let control_stream_readable =
+            |e| matches!(e, ConnectionEvent::RecvStreamReadable{stream_id: x} if x == 2);
+        assert!(server.conn.events().any(control_stream_readable));
+        let mut buf = [0_u8; 100];
+        let (amount, fin) = server.conn.stream_recv(StreamId::new(2), &mut buf).unwrap();
+        assert!(!fin);
+
+        assert_eq!(amount, MAX_PUSH_ID_FRAME.len());
+        assert_eq!(&buf[..3], MAX_PUSH_ID_FRAME);
+
+        // Check that we can send push_id=8 now
+        send_push_promise(&mut server.conn, request_stream_id, 8);
+        send_push_data(&mut server.conn, 8, true);
+
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        assert_eq!(client.state(), Http3State::Connected);
+
+        read_response_and_push_events(
+            &mut client,
+            &[PushPromiseInfo {
+                push_id: 8,
+                ref_stream_id: request_stream_id,
+            }],
+            &[8],
+            request_stream_id,
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test that 2 push streams with the same push_id are caught.
+    #[test]
+    fn duplicate_push_stream() {
+        // Connect and send a request
+        let (mut client, mut server, _request_stream_id) = connect_and_send_request(true);
+
+        // Start a push stream with push_id 0.
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+
+        // Send it again
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    // Test that 2 push streams with the same push_id are caught.
+    #[test]
+    fn duplicate_push_stream_active() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+        // Now the push_stream is in the PushState::Active state
+
+        send_push_data_and_exchange_packets(&mut client, &mut server, 0, true);
+
+        assert_closed(&client, &Error::HttpId);
+    }
+
+    fn assert_stop_sending_event(
+        server: &mut TestServer,
+        push_stream_id: StreamId,
+        expected_error: u64,
+    ) {
+        assert!(server.conn.events().any(|e| matches!(
+            e,
+            ConnectionEvent::SendStreamStopSending {
+                stream_id,
+                app_error,
+            } if stream_id == push_stream_id && app_error == expected_error
+        )));
+    }
+
+    // Test CANCEL_PUSH frame: after cancel push any new PUSH_PROMISE or push stream will be
+    // ignored.
+    #[test]
+    fn cancel_push_ignore_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_cancel_push_and_exchange_packets(&mut client, &mut server, 0);
+
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        // Start a push stream with push_id 0.
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        // Check that the push has been canceled by the client.
+        assert_stop_sending_event(
+            &mut server,
+            push_stream_id,
+            Error::HttpRequestCancelled.code(),
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test CANCEL_PUSH frame: after cancel push any already received PUSH_PROMISE or push stream
+    // events will be removed.
+    #[test]
+    fn cancel_push_removes_push_events() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        send_cancel_push_and_exchange_packets(&mut client, &mut server, 0);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        // Check that the push has been canceled by the client.
+        assert_stop_sending_event(
+            &mut server,
+            push_stream_id,
+            Error::HttpRequestCancelled.code(),
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test CANCEL_PUSH frame: after cancel push any already received push stream will be canceled.
+    #[test]
+    fn cancel_push_frame_after_push_stream() {
+        // Connect and send a request
+        let (mut client, mut server, _) = connect_and_send_request(true);
+
+        // Start a push stream with push_id 0.
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        send_cancel_push_and_exchange_packets(&mut client, &mut server, 0);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        // Check that the push has been canceled by the client.
+        assert_stop_sending_event(
+            &mut server,
+            push_stream_id,
+            Error::HttpRequestCancelled.code(),
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test a push stream reset after a new PUSH_PROMISE or/and push stream. The events will be
+    // ignored.
+    #[test]
+    fn cancel_push_stream_after_push_promise_and_push_stream() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise(&mut server.conn, request_stream_id, 0);
+        // Start a push stream with push_id 0.
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        server
+            .conn
+            .stream_reset_send(push_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test that a PUSH_PROMISE will be ignored after a push stream reset.
+    #[test]
+    fn cancel_push_stream_before_push_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Start a push stream with push_id 0.
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        server
+            .conn
+            .stream_reset_send(push_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test that push_promise events will be removed after application calls cancel_push.
+    #[test]
+    fn app_cancel_push_after_push_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+
+        assert!(client.cancel_push(0).is_ok());
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test that push_promise and push data events will be removed after application calls
+    // cancel_push.
+    #[test]
+    fn app_cancel_push_after_push_promise_and_push_stream() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        assert!(client.cancel_push(0).is_ok());
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        // Check that the push has been canceled by the client.
+        assert_stop_sending_event(
+            &mut server,
+            push_stream_id,
+            Error::HttpRequestCancelled.code(),
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    // Test that push_promise events will be ignored after application calls cancel_push.
+    #[test]
+    fn app_cancel_push_before_push_promise() {
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+        let push_stream_id =
+            send_push_data_and_exchange_packets(&mut client, &mut server, 0, false);
+
+        assert!(client.cancel_push(0).is_ok());
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        send_push_promise_and_exchange_packets(&mut client, &mut server, request_stream_id, 0);
+
+        // Assert that we do not have any push event.
+        assert!(!check_push_events(&mut client));
+
+        // Check that the push has been closed, e.g. calling cancel_push should return
+        // InvalidStreamId.
+        assert_eq!(client.cancel_push(0), Err(Error::InvalidStreamId));
+
+        // Check that the push has been canceled by the client.
+        assert_stop_sending_event(
+            &mut server,
+            push_stream_id,
+            Error::HttpRequestCancelled.code(),
+        );
+
+        assert_eq!(client.state(), Http3State::Connected);
+    }
+
+    fn setup_server_side_encoder_param(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        max_blocked_streams: u64,
+    ) {
+        server
+            .encoder
+            .borrow_mut()
+            .set_max_capacity(max_blocked_streams)
+            .unwrap();
+        server
+            .encoder
+            .borrow_mut()
+            .set_max_blocked_streams(100)
+            .unwrap();
+        server
+            .encoder
+            .borrow_mut()
+            .send_encoder_updates(&mut server.conn)
+            .unwrap();
+        let out = server.conn.process(None, now());
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+    }
+
+    fn setup_server_side_encoder(client: &mut Http3Client, server: &mut TestServer) {
+        setup_server_side_encoder_param(client, server, 100);
+    }
+
+    fn send_push_promise_using_encoder(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        stream_id: StreamId,
+        push_id: u64,
+    ) -> Option<Datagram> {
+        send_push_promise_using_encoder_with_custom_headers(
+            client,
+            server,
+            stream_id,
+            push_id,
+            Header::new("my-header", "my-value"),
+        )
+    }
+
+    fn send_push_promise_using_encoder_with_custom_headers(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        stream_id: StreamId,
+        push_id: u64,
+        additional_header: Header,
+    ) -> Option<Datagram> {
+        let mut headers = vec![
+            Header::new(":method", "GET"),
+            Header::new(":scheme", "https"),
+            Header::new(":authority", "something.com"),
+            Header::new(":path", "/"),
+            Header::new("content-length", "3"),
+        ];
+        headers.push(additional_header);
+
+        let encoded_headers =
+            server
+                .encoder
+                .borrow_mut()
+                .encode_header_block(&mut server.conn, &headers, stream_id);
+        let push_promise_frame = HFrame::PushPromise {
+            push_id,
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions, but delay them so that the stream is blocked on decoding
+        // headers.
+        let encoder_inst_pkt = server.conn.process(None, now()).dgram();
+        assert!(encoder_inst_pkt.is_some());
+
+        let mut d = Encoder::default();
+        push_promise_frame.encode(&mut d);
+        server_send_response_and_exchange_packet(client, server, stream_id, &d, false);
+
+        encoder_inst_pkt
+    }
+
+    #[test]
+    fn push_promise_header_decoder_block() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let encoder_inst_pkt =
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0);
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt.as_ref(), now());
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(check_push_events(&mut client));
+    }
+
+    // If PushPromise is blocked, stream data can still be received.
+    #[test]
+    fn push_promise_blocked_but_stream_is_not_blocked() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        // Send response headers
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_HEADER_ONLY_1,
+            false,
+        );
+
+        let encoder_inst_pkt =
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0);
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        // Stream data can be still read
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_DATA_FRAME_1_ONLY_1,
+            false,
+        );
+
+        assert!(check_data_readable(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt.as_ref(), now());
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(check_push_events(&mut client));
+
+        // Stream data can be still read
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_DATA_FRAME_2_ONLY_1,
+            false,
+        );
+
+        assert!(check_data_readable(&mut client));
+    }
+
+    // The response Headers are not block if they do not refer the dynamic table.
+    #[test]
+    fn push_promise_does_not_block_headers() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let encoder_inst_pkt =
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0);
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        // Send response headers
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_HEADER_ONLY_1,
+            false,
+        );
+
+        assert!(check_header_ready(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt.as_ref(), now());
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(check_push_events(&mut client));
+    }
+
+    // The response Headers are blocked if they refer a dynamic table entry.
+    #[test]
+    fn push_promise_block_headers() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        // Insert an elemet into a dynamic table.
+        // insert "content-length: 1234
+        server
+            .encoder
+            .borrow_mut()
+            .send_and_insert(&mut server.conn, b"content-length", b"1234")
+            .unwrap();
+        let encoder_inst_pkt1 = server.conn.process(None, now()).dgram();
+        let _out = client.process(encoder_inst_pkt1.as_ref(), now());
+
+        // Send a PushPromise that is blocked until encoder_inst_pkt2 is process by the client.
+        let encoder_inst_pkt2 =
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0);
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        let response_headers = vec![
+            Header::new(":status", "200"),
+            Header::new("content-length", "1234"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &response_headers,
+            request_stream_id,
+        );
+        let header_hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+        let mut d = Encoder::default();
+        header_hframe.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // The response headers are blocked.
+        assert!(!check_header_ready(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt2.as_ref(), now());
+
+        // The response headers are blocked.
+        assert!(check_header_ready_and_push_promise(&mut client));
+    }
+
+    // In this test there are 2 push promises that are blocked and the response header is
+    // blocked as well. After a packet is received only the first push promises is unblocked.
+    #[test]
+    fn two_push_promises_and_header_block() {
+        let mut client = default_http3_client_param(200);
+        let mut server = TestServer::new_with_settings(&[
+            HSetting::new(HSettingType::MaxTableCapacity, 200),
+            HSetting::new(HSettingType::BlockedStreams, 100),
+            HSetting::new(HSettingType::MaxHeaderListSize, 10000),
+        ]);
+        connect_only_transport_with(&mut client, &mut server);
+        server.create_control_stream();
+        server.create_qpack_streams();
+        setup_server_side_encoder_param(&mut client, &mut server, 200);
+
+        let request_stream_id = make_request_and_exchange_pkts(&mut client, &mut server, true);
+
+        // Send a PushPromise that is blocked until encoder_inst_pkt2 is process by the client.
+        let encoder_inst_pkt1 = send_push_promise_using_encoder_with_custom_headers(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            0,
+            Header::new("myn1", "myv1"),
+        );
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        let encoder_inst_pkt2 = send_push_promise_using_encoder_with_custom_headers(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            1,
+            Header::new("myn2", "myv2"),
+        );
+
+        // PushPromise is blocked wathing for encoder instructions.
+        assert!(!check_push_events(&mut client));
+
+        let response_headers = vec![
+            Header::new(":status", "200"),
+            Header::new("content-length", "1234"),
+            Header::new("myn3", "myv3"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &response_headers,
+            request_stream_id,
+        );
+        let header_hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+        let mut d = Encoder::default();
+        header_hframe.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // The response headers are blocked.
+        assert!(!check_header_ready(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt1.as_ref(), now());
+
+        assert!(check_push_events(&mut client));
+
+        // Let client receive the encoder instructions.
+        let _out = client.process(encoder_inst_pkt2.as_ref(), now());
+
+        assert!(check_header_ready_and_push_promise(&mut client));
+    }
+
+    // The PushPromise blocked on header decoding will be canceled if the stream is closed.
+    #[test]
+    fn blocked_push_promises_canceled() {
+        const STREAM_CANCELED_ID_0: &[u8] = &[0x40];
+
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        mem::drop(
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0)
+                .unwrap(),
+        );
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_1,
+            true,
+        );
+
+        // Read response that will make stream change to closed state.
+        assert!(check_header_ready(&mut client));
+        let mut buf = [0_u8; 100];
+        _ = client
+            .read_data(now(), request_stream_id, &mut buf)
+            .unwrap();
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        // Check that encoder got stream_canceled instruction.
+        let mut inst = [0_u8; 100];
+        let (amount, fin) = server
+            .conn
+            .stream_recv(CLIENT_SIDE_DECODER_STREAM_ID, &mut inst)
+            .unwrap();
+        assert!(!fin);
+        assert_eq!(amount, STREAM_CANCELED_ID_0.len());
+        assert_eq!(&inst[..amount], STREAM_CANCELED_ID_0);
+    }
+
+    #[test]
+    fn data_readable_in_decoder_blocked_state() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "0"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Delay encoder instruction so that the stream will be blocked.
+        let encoder_insts = server.conn.process(None, now());
+
+        // Send response headers.
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Headers are blocked waiting fro the encoder instructions.
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!client.events().any(header_ready_event));
+
+        // Now send data frame. This will trigger DataRead event.
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data { len: 0 };
+        d_frame.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        // Now read headers.
+        mem::drop(client.process(encoder_insts.as_dgram_ref(), now()));
+    }
+
+    #[test]
+    fn qpack_stream_reset() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        setup_server_side_encoder(&mut client, &mut server);
+        // Cancel request.
+        mem::drop(client.cancel_fetch(request_stream_id, Error::HttpRequestCancelled.code()));
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn));
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 1);
+    }
+
+    fn send_headers_using_encoder(
+        client: &mut Http3Client,
+        server: &mut TestServer,
+        request_stream_id: StreamId,
+        headers: &[Header],
+        data: &[u8],
+    ) -> Option<Datagram> {
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        let out = server.conn.process(None, now());
+
+        // Send response
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data {
+            len: u64::try_from(data.len()).unwrap(),
+        };
+        d_frame.encode(&mut d);
+        d.encode(data);
+        server_send_response_and_exchange_packet(client, server, request_stream_id, &d, true);
+
+        out.dgram()
+    }
+
+    #[test]
+    fn qpack_stream_reset_recv() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        setup_server_side_encoder(&mut client, &mut server);
+
+        // Cancel request.
+        server
+            .conn
+            .stream_reset_send(request_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+        let out = server.conn.process(None, now());
+        let out = client.process(out.as_dgram_ref(), now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn));
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 1);
+    }
+
+    #[test]
+    fn qpack_stream_reset_during_header_qpack_blocked() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        mem::drop(
+            send_headers_using_encoder(
+                &mut client,
+                &mut server,
+                request_stream_id,
+                &[
+                    Header::new(":status", "200"),
+                    Header::new("my-header", "my-header"),
+                    Header::new("content-length", "3"),
+                ],
+                &[0x61, 0x62, 0x63],
+            )
+            .unwrap(),
+        );
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!client.events().any(header_ready_event));
+
+        // Cancel request.
+        client
+            .cancel_fetch(request_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn).unwrap());
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 1);
+    }
+
+    #[test]
+    fn qpack_no_stream_cancelled_after_fin() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let encoder_instruct = send_headers_using_encoder(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &[
+                Header::new(":status", "200"),
+                Header::new("my-header", "my-header"),
+                Header::new("content-length", "3"),
+            ],
+            &[],
+        );
+
+        // Exchange encoder instructions
+        mem::drop(client.process(encoder_instruct.as_ref(), now()));
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(client.events().any(header_ready_event));
+        // After this the recv_stream is in ClosePending state
+
+        // Cancel request.
+        client
+            .cancel_fetch(request_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn).unwrap());
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+    }
+
+    #[test]
+    fn qpack_stream_reset_push_promise_header_decoder_block() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new("content-length", "3"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions.
+        let out = server.conn.process(None, now());
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+
+        // Send PushPromise that will be blocked waiting for decoder instructions.
+        mem::drop(
+            send_push_promise_using_encoder(&mut client, &mut server, request_stream_id, 0)
+                .unwrap(),
+        );
+
+        // Send response
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data { len: 0 };
+        d_frame.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(client.events().any(header_ready_event));
+
+        // Cancel request.
+        client
+            .cancel_fetch(request_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn).unwrap());
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 1);
+    }
+
+    #[test]
+    fn qpack_stream_reset_dynamic_table_zero() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+        // Cancel request.
+        client
+            .cancel_fetch(request_stream_id, Error::HttpRequestCancelled.code())
+            .unwrap();
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+        mem::drop(server.encoder_receiver.receive(&mut server.conn).unwrap());
+        assert_eq!(server.encoder.borrow_mut().stats().stream_cancelled_recv, 0);
+    }
+
+    #[test]
+    fn multiple_streams_in_decoder_blocked_state() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "0"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Delay encoder instruction so that the stream will be blocked.
+        let encoder_insts = server.conn.process(None, now());
+
+        // Send response headers.
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        // Headers are blocked waiting for the encoder instructions.
+        let header_ready_event = |e| matches!(e, Http3ClientEvent::HeaderReady { .. });
+        assert!(!client.events().any(header_ready_event));
+
+        // Make another request.
+        let request2 = make_request_and_exchange_pkts(&mut client, &mut server, true);
+        // Send response headers.
+        server_send_response_and_exchange_packet(&mut client, &mut server, request2, &d, true);
+
+        // Headers on the second request are blocked as well are blocked
+        // waiting for the encoder instructions.
+        assert!(!client.events().any(header_ready_event));
+
+        // Now make the encoder instructions available.
+        mem::drop(client.process(encoder_insts.as_dgram_ref(), now()));
+
+        // Header blocks for both streams should be ready.
+        let mut count_responses = 0;
+        while let Some(e) = client.next_event() {
+            if let Http3ClientEvent::HeaderReady { stream_id, .. } = e {
+                assert!((stream_id == request_stream_id) || (stream_id == request2));
+                count_responses += 1;
+            }
+        }
+        assert_eq!(count_responses, 2);
+    }
+
+    #[test]
+    fn reserved_frames() {
+        for f in H3_RESERVED_FRAME_TYPES {
+            let mut enc = Encoder::default();
+            enc.encode_varint(*f);
+            test_wrong_frame_on_control_stream(enc.as_ref());
+            test_wrong_frame_on_push_stream(enc.as_ref());
+            test_wrong_frame_on_request_stream(enc.as_ref());
+        }
+    }
+
+    #[test]
+    fn send_reserved_settings() {
+        for s in H3_RESERVED_SETTINGS {
+            let (mut client, mut server) = connect_only_transport();
+            let control_stream = server.conn.stream_create(StreamType::UniDi).unwrap();
+            // Send the control stream type(0x0).
+            _ = server
+                .conn
+                .stream_send(control_stream, CONTROL_STREAM_TYPE)
+                .unwrap();
+            // Create a settings frame of length 2.
+            let mut enc = Encoder::default();
+            enc.encode_varint(H3_FRAME_TYPE_SETTINGS);
+            enc.encode_varint(2_u64);
+            // The settings frame contains a reserved settings type and some value (0x1).
+            enc.encode_varint(*s);
+            enc.encode_varint(1_u64);
+            let sent = server.conn.stream_send(control_stream, enc.as_ref());
+            assert_eq!(sent, Ok(4));
+            let out = server.conn.process(None, now());
+            client.process(out.as_dgram_ref(), now());
+            assert_closed(&client, &Error::HttpSettings);
+        }
+    }
+
+    #[test]
+    fn response_w_1xx() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let mut d = Encoder::default();
+        let headers1xx: &[Header] = &[Header::new(":status", "103")];
+        server.encode_headers(request_stream_id, headers1xx, &mut d);
+
+        let headers200: &[Header] = &[
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        server.encode_headers(request_stream_id, headers200, &mut d);
+
+        // Send 1xx and 200 headers response.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Sending response data.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_DATA_FRAME_ONLY_2,
+            true,
+        );
+
+        let mut events = client.events().filter_map(|e| {
+            if let Http3ClientEvent::HeaderReady {
+                stream_id,
+                interim,
+                headers,
+                ..
+            } = e
+            {
+                Some((stream_id, interim, headers))
+            } else {
+                None
+            }
+        });
+        let (stream_id_1xx_rec, interim1xx_rec, headers1xx_rec) = events.next().unwrap();
+        assert_eq!(
+            (stream_id_1xx_rec, interim1xx_rec, headers1xx_rec.as_ref()),
+            (request_stream_id, true, headers1xx)
+        );
+
+        let (stream_id_200_rec, interim200_rec, headers200_rec) = events.next().unwrap();
+        assert_eq!(
+            (stream_id_200_rec, interim200_rec, headers200_rec.as_ref()),
+            (request_stream_id, false, headers200)
+        );
+        assert!(events.next().is_none());
+    }
+
+    #[test]
+    fn response_wo_status() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let mut d = Encoder::default();
+        let headers = vec![
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        server.encode_headers(request_stream_id, &headers, &mut d);
+
+        // Send response
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Stream has been reset because of the malformed headers.
+        let e = client.events().next().unwrap();
+        assert_eq!(
+            e,
+            Http3ClientEvent::Reset {
+                stream_id: request_stream_id,
+                error: Error::InvalidHeader.code(),
+                local: true,
+            }
+        );
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // Check that server has received a reset.
+        let stop_sending_event = |e| {
+            matches!(e, ConnectionEvent::SendStreamStopSending {
+            stream_id,
+            app_error
+        } if stream_id == request_stream_id && app_error == Error::InvalidHeader.code())
+        };
+        assert!(server.conn.events().any(stop_sending_event));
+
+        // Stream should now be closed and gone
+        let mut buf = [0_u8; 100];
+        assert_eq!(
+            client.read_data(now(), StreamId::new(0), &mut buf),
+            Err(Error::InvalidStreamId)
+        );
+    }
+
+    // Client: receive a push stream
+    #[test]
+    fn push_single_with_1xx() {
+        const FIRST_PUSH_ID: u64 = 0;
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, FIRST_PUSH_ID);
+        // Create a push stream
+        let push_stream_id = server.conn.stream_create(StreamType::UniDi).unwrap();
+
+        let mut d = Encoder::default();
+        let headers1xx: &[Header] = &[Header::new(":status", "100")];
+        server.encode_headers(push_stream_id, headers1xx, &mut d);
+
+        let headers200: &[Header] = &[
+            Header::new(":status", "200"),
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        server.encode_headers(push_stream_id, headers200, &mut d);
+
+        // create a push stream.
+        send_data_on_push(
+            &mut server.conn,
+            push_stream_id,
+            u8::try_from(FIRST_PUSH_ID).unwrap(),
+            &d,
+            true,
+        );
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        let mut events = client.events().filter_map(|e| {
+            if let Http3ClientEvent::PushHeaderReady {
+                push_id,
+                interim,
+                headers,
+                ..
+            } = e
+            {
+                Some((push_id, interim, headers))
+            } else {
+                None
+            }
+        });
+
+        let (push_id_1xx_rec, interim1xx_rec, headers1xx_rec) = events.next().unwrap();
+        assert_eq!(
+            (push_id_1xx_rec, interim1xx_rec, headers1xx_rec.as_ref()),
+            (FIRST_PUSH_ID, true, headers1xx)
+        );
+
+        let (push_id_200_rec, interim200_rec, headers200_rec) = events.next().unwrap();
+        assert_eq!(
+            (push_id_200_rec, interim200_rec, headers200_rec.as_ref()),
+            (FIRST_PUSH_ID, false, headers200)
+        );
+        assert!(events.next().is_none());
+    }
+
+    // Client: receive a push stream
+    #[test]
+    fn push_single_wo_status() {
+        const FIRST_PUSH_ID: u64 = 0;
+        // Connect and send a request
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        // Send a push promise.
+        send_push_promise(&mut server.conn, request_stream_id, FIRST_PUSH_ID);
+        // Create a push stream
+        let push_stream_id = server.conn.stream_create(StreamType::UniDi).unwrap();
+
+        let mut d = Encoder::default();
+        let headers = vec![
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        server.encode_headers(request_stream_id, &headers, &mut d);
+
+        send_data_on_push(
+            &mut server.conn,
+            push_stream_id,
+            u8::try_from(FIRST_PUSH_ID).unwrap(),
+            &d,
+            false,
+        );
+
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            HTTP_RESPONSE_2,
+            true,
+        );
+
+        // Stream has been reset because of thei malformed headers.
+        let push_reset_event = |e| {
+            matches!(e, Http3ClientEvent::PushReset {
+            push_id,
+            error,
+        } if push_id == FIRST_PUSH_ID && error == Error::InvalidHeader.code())
+        };
+
+        assert!(client.events().any(push_reset_event));
+
+        let out = client.process(None, now());
+        mem::drop(server.conn.process(out.as_dgram_ref(), now()));
+
+        // Check that server has received a reset.
+        let stop_sending_event = |e| {
+            matches!(e, ConnectionEvent::SendStreamStopSending {
+            stream_id,
+            app_error
+        } if stream_id == push_stream_id && app_error == Error::InvalidHeader.code())
+        };
+        assert!(server.conn.events().any(stop_sending_event));
+    }
+
+    fn handshake_client_error(client: &mut Http3Client, server: &mut TestServer, error: &Error) {
+        let out = handshake_only(client, server);
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(client, error);
+    }
+
+    /// Client fails to create a control stream, since server does not allow it.
+    #[test]
+    fn client_control_stream_create_failed() {
+        let mut client = default_http3_client();
+        let mut server = TestServer::new_with_conn(new_server(
+            DEFAULT_ALPN_H3,
+            ConnectionParameters::default().max_streams(StreamType::UniDi, 0),
+        ));
+        handshake_client_error(&mut client, &mut server, &Error::StreamLimitError);
+    }
+
+    /// 2 streams isn't enough for control and QPACK streams.
+    #[test]
+    fn client_qpack_stream_create_failed() {
+        let mut client = default_http3_client();
+        let mut server = TestServer::new_with_conn(new_server(
+            DEFAULT_ALPN_H3,
+            ConnectionParameters::default().max_streams(StreamType::UniDi, 2),
+        ));
+        handshake_client_error(&mut client, &mut server, &Error::StreamLimitError);
+    }
+
+    fn do_malformed_response_test(headers: &[Header]) {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let mut d = Encoder::default();
+        server.encode_headers(request_stream_id, headers, &mut d);
+
+        // Send response
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Stream has been reset because of the malformed headers.
+        let e = client.events().next().unwrap();
+        assert_eq!(
+            e,
+            Http3ClientEvent::Reset {
+                stream_id: request_stream_id,
+                error: Error::InvalidHeader.code(),
+                local: true,
+            }
+        );
+    }
+
+    #[test]
+    fn malformed_response_pseudo_header_after_regular_header() {
+        do_malformed_response_test(&[
+            Header::new("content-type", "text/plain"),
+            Header::new(":status", "100"),
+        ]);
+    }
+
+    #[test]
+    fn malformed_response_undefined_pseudo_header() {
+        do_malformed_response_test(&[Header::new(":status", "200"), Header::new(":cheese", "200")]);
+    }
+
+    #[test]
+    fn malformed_response_duplicate_pseudo_header() {
+        do_malformed_response_test(&[
+            Header::new(":status", "200"),
+            Header::new(":status", "100"),
+            Header::new("content-type", "text/plain"),
+        ]);
+    }
+
+    #[test]
+    fn malformed_response_uppercase_header() {
+        do_malformed_response_test(&[
+            Header::new(":status", "200"),
+            Header::new("content-Type", "text/plain"),
+        ]);
+    }
+
+    #[test]
+    fn malformed_response_excluded_header() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let mut d = Encoder::default();
+        server.encode_headers(
+            request_stream_id,
+            &[
+                Header::new(":status", "200"),
+                Header::new("content-type", "text/plain"),
+                Header::new("connection", "close"),
+            ],
+            &mut d,
+        );
+
+        // Send response
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Stream has been reset because of the malformed headers.
+        let e = client.events().next().unwrap();
+        assert_eq!(
+            e,
+            Http3ClientEvent::HeaderReady {
+                stream_id: request_stream_id,
+                headers: vec![
+                    Header::new(":status", "200"),
+                    Header::new("content-type", "text/plain")
+                ],
+                interim: false,
+                fin: false,
+            }
+        );
+    }
+
+    #[test]
+    fn malformed_response_excluded_byte_in_header() {
+        do_malformed_response_test(&[
+            Header::new(":status", "200"),
+            Header::new("content:type", "text/plain"),
+        ]);
+    }
+
+    #[test]
+    fn malformed_response_request_header_in_response() {
+        do_malformed_response_test(&[
+            Header::new(":status", "200"),
+            Header::new(":method", "GET"),
+            Header::new("content-type", "text/plain"),
+        ]);
+    }
+
+    fn maybe_authenticate(conn: &mut Http3Client) {
+        let authentication_needed = |e| matches!(e, Http3ClientEvent::AuthenticationNeeded);
+        if conn.events().any(authentication_needed) {
+            conn.authenticated(AuthenticationStatus::Ok, now());
+        }
+    }
+
+    const MAX_TABLE_SIZE: u64 = 65536;
+    const MAX_BLOCKED_STREAMS: u16 = 5;
+
+    fn get_resumption_token(server: &mut Http3Server) -> ResumptionToken {
+        let mut client = default_http3_client_param(MAX_TABLE_SIZE);
+
+        let mut datagram = None;
+        let is_done = |c: &Http3Client| matches!(c.state(), Http3State::Connected);
+        while !is_done(&mut client) {
+            maybe_authenticate(&mut client);
+            datagram = client.process(datagram.as_ref(), now()).dgram();
+            datagram = server.process(datagram.as_ref(), now()).dgram();
+        }
+
+        // exchange qpack settings, server will send a token as well.
+        datagram = client.process(datagram.as_ref(), now()).dgram();
+        datagram = server.process(datagram.as_ref(), now()).dgram();
+        mem::drop(client.process(datagram.as_ref(), now()).dgram());
+
+        client
+            .events()
+            .find_map(|e| {
+                if let Http3ClientEvent::ResumptionToken(token) = e {
+                    Some(token)
+                } else {
+                    None
+                }
+            })
+            .unwrap()
+    }
+
+    // Test that decoder stream type is always sent before any other instruction also
+    // in case when 0RTT is used.
+    // A client will send a request that uses the dynamic table. This will trigger a header-ack
+    // from a server. We will use stats to check that a header-ack has been received.
+    #[test]
+    fn zerortt_request_use_dynamic_table() {
+        let mut server = Http3Server::new(
+            now(),
+            DEFAULT_KEYS,
+            DEFAULT_ALPN_H3,
+            anti_replay(),
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            Http3Parameters::default()
+                .max_table_size_encoder(MAX_TABLE_SIZE)
+                .max_table_size_decoder(MAX_TABLE_SIZE)
+                .max_blocked_streams(MAX_BLOCKED_STREAMS),
+            None,
+        )
+        .unwrap();
+
+        let token = get_resumption_token(&mut server);
+        // Make a new connection.
+        let mut client = default_http3_client_param(MAX_TABLE_SIZE);
+        assert_eq!(client.state(), Http3State::Initializing);
+        client
+            .enable_resumption(now(), &token)
+            .expect("Set resumption token.");
+
+        assert_eq!(client.state(), Http3State::ZeroRtt);
+        let zerortt_event = |e| matches!(e, Http3ClientEvent::StateChange(Http3State::ZeroRtt));
+        assert!(client.events().any(zerortt_event));
+
+        // Make a request that uses the dynamic table.
+        _ = make_request(&mut client, true, &[Header::new("myheaders", "myvalue")]);
+        // Assert that the request has used dynamic table. That will trigger a header_ack.
+        assert_eq!(client.qpack_encoder_stats().dynamic_table_references, 1);
+
+        // Exchange packets until header-ack is received.
+        // These many packet exchange is needed, to get a header-ack.
+        // TODO this may be optimize at Http3Server.
+        let out = client.process(None, now());
+        let out = server.process(out.as_dgram_ref(), now());
+        let out = client.process(out.as_dgram_ref(), now());
+        let out = server.process(out.as_dgram_ref(), now());
+        let out = client.process(out.as_dgram_ref(), now());
+        let out = server.process(out.as_dgram_ref(), now());
+        let out = client.process(out.as_dgram_ref(), now());
+        let out = server.process(out.as_dgram_ref(), now());
+        mem::drop(client.process(out.as_dgram_ref(), now()));
+
+        // The header ack for the first request has been received.
+        assert_eq!(client.qpack_encoder_stats().header_acks_recv, 1);
+    }
+
+    fn manipulate_conrol_stream(client: &mut Http3Client, stream_id: StreamId) {
+        assert_eq!(
+            client
+                .cancel_fetch(stream_id, Error::HttpNoError.code())
+                .unwrap_err(),
+            Error::InvalidStreamId
+        );
+        assert_eq!(
+            client.stream_close_send(stream_id).unwrap_err(),
+            Error::InvalidStreamId
+        );
+        let mut buf = [0; 2];
+        assert_eq!(
+            client.send_data(stream_id, &buf).unwrap_err(),
+            Error::InvalidStreamId
+        );
+        assert_eq!(
+            client.read_data(now(), stream_id, &mut buf).unwrap_err(),
+            Error::InvalidStreamId
+        );
+    }
+
+    #[test]
+    fn manipulate_conrol_streams() {
+        let (mut client, server, request_stream_id) = connect_and_send_request(false);
+        manipulate_conrol_stream(&mut client, CLIENT_SIDE_CONTROL_STREAM_ID);
+        manipulate_conrol_stream(&mut client, CLIENT_SIDE_ENCODER_STREAM_ID);
+        manipulate_conrol_stream(&mut client, CLIENT_SIDE_DECODER_STREAM_ID);
+        manipulate_conrol_stream(&mut client, server.control_stream_id.unwrap());
+        manipulate_conrol_stream(&mut client, server.encoder_stream_id.unwrap());
+        manipulate_conrol_stream(&mut client, server.decoder_stream_id.unwrap());
+        client
+            .cancel_fetch(request_stream_id, Error::HttpNoError.code())
+            .unwrap();
+    }
+
+    // Client: receive a push stream
+    #[test]
+    fn incomple_push_stream() {
+        let (mut client, mut server) = connect();
+
+        // Create a push stream
+        let push_stream_id = server.conn.stream_create(StreamType::UniDi).unwrap();
+        _ = server
+            .conn
+            .stream_send(push_stream_id, PUSH_STREAM_TYPE)
+            .unwrap();
+        _ = server.conn.stream_send(push_stream_id, &[0]).unwrap();
+        server.conn.stream_close_send(push_stream_id).unwrap();
+        let out = server.conn.process(None, now());
+        client.process(out.as_dgram_ref(), now());
+        assert_closed(&client, &Error::HttpGeneralProtocol);
+    }
+
+    #[test]
+    fn priority_update_during_full_buffer() {
+        // set a lower MAX_DATA on the server side to restrict the data the client can send
+        let (mut client, mut server) =
+            connect_with_connection_parameters(ConnectionParameters::default().max_data(1200));
+
+        let request_stream_id = make_request_and_exchange_pkts(&mut client, &mut server, false);
+        let data_writable = |e| matches!(e, Http3ClientEvent::DataWritable { .. });
+        assert!(client.events().any(data_writable));
+        // Send a lot of data to reach the flow control limit
+        client.send_data(request_stream_id, &[0; 2000]).unwrap();
+
+        // now queue a priority_update packet for that stream
+        assert!(client
+            .priority_update(request_stream_id, Priority::new(6, false))
+            .unwrap());
+
+        let md_before = server.conn.stats().frame_tx.max_data;
+
+        // sending the http request and most most of the request data
+        let out = client.process(None, now());
+        let out = server.conn.process(out.as_dgram_ref(), now());
+
+        // the server responses with an ack, but the max_data didn't change
+        assert_eq!(md_before, server.conn.stats().frame_tx.max_data);
+
+        let out = client.process(out.as_dgram_ref(), now());
+        let out = server.conn.process(out.as_dgram_ref(), now());
+
+        // the server increased the max_data during the second read if that isn't the case
+        // in the future and therefore this asserts fails, the request data on stream 0 could be
+        // read to cause a max_update frame
+        assert_eq!(md_before + 1, server.conn.stats().frame_tx.max_data);
+
+        // make sure that the server didn't receive a priority_update on client control stream
+        // (stream_id 2) yet
+        let mut buf = [0; 32];
+        assert_eq!(
+            server.conn.stream_recv(StreamId::new(2), &mut buf),
+            Ok((0, false))
+        );
+
+        // the client now sends the priority update
+        let out = client.process(out.as_dgram_ref(), now());
+        server
+            .conn
+            .process_input(out.as_dgram_ref().unwrap(), now());
+
+        // check that the priority_update arrived at the client control stream
+        let num_read = server.conn.stream_recv(StreamId::new(2), &mut buf).unwrap();
+        assert_eq!(b"\x80\x0f\x07\x00\x04\x00\x75\x3d\x36", &buf[0..num_read.0]);
+    }
+
+    #[test]
+    fn error_request_stream() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let headers = vec![
+            Header::new(":status", "200"),
+            Header::new(":method", "GET"), // <- invalid
+            Header::new("my-header", "my-header"),
+            Header::new("content-length", "3"),
+        ];
+        let encoded_headers = server.encoder.borrow_mut().encode_header_block(
+            &mut server.conn,
+            &headers,
+            request_stream_id,
+        );
+        let hframe = HFrame::Headers {
+            header_block: encoded_headers.to_vec(),
+        };
+
+        // Send the encoder instructions, but delay them so that the stream is blocked on decoding
+        // headers.
+        let encoder_inst_pkt = server.conn.process(None, now());
+
+        // Send response
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        let d_frame = HFrame::Data { len: 3 };
+        d_frame.encode(&mut d);
+        d.encode(b"abc");
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            true,
+        );
+
+        // Let client receive the encoder instructions.
+        client.process_input(encoder_inst_pkt.as_dgram_ref().unwrap(), now());
+
+        let reset_event = |e| matches!(e, Http3ClientEvent::Reset { stream_id, .. } if stream_id == request_stream_id);
+        assert!(client.events().any(reset_event));
+    }
+
+    #[test]
+    fn response_w_101() {
+        let (mut client, mut server, request_stream_id) = connect_and_send_request(true);
+
+        setup_server_side_encoder(&mut client, &mut server);
+
+        let mut d = Encoder::default();
+        let headers1xx = &[Header::new(":status", "101")];
+        server.encode_headers(request_stream_id, headers1xx, &mut d);
+
+        // Send 101 response.
+        server_send_response_and_exchange_packet(
+            &mut client,
+            &mut server,
+            request_stream_id,
+            &d,
+            false,
+        );
+
+        // Stream has been reset because of the 101 response.
+        let e = client.events().next().unwrap();
+        assert_eq!(
+            e,
+            Http3ClientEvent::Reset {
+                stream_id: request_stream_id,
+                error: Error::InvalidHeader.code(),
+                local: true,
+            }
+        );
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/connection_server.rs b/third_party/rust/neqo-http3/src/connection_server.rs
new file mode 100644
index 0000000000..097209a226
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/connection_server.rs
@@ -0,0 +1,420 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{rc::Rc, time::Instant};
+
+use neqo_common::{event::Provider, qdebug, qinfo, qtrace, Header, MessageType, Role};
+use neqo_transport::{
+    AppError, Connection, ConnectionEvent, DatagramTracking, StreamId, StreamType,
+};
+
+use crate::{
+    connection::{Http3Connection, Http3State, WebTransportSessionAcceptAction},
+    frames::HFrame,
+    recv_message::{RecvMessage, RecvMessageInfo},
+    send_message::SendMessage,
+    server_connection_events::{Http3ServerConnEvent, Http3ServerConnEvents},
+    Error, Http3Parameters, Http3StreamType, NewStreamType, Priority, PriorityHandler,
+    ReceiveOutput, Res,
+};
+
+#[derive(Debug)]
+pub struct Http3ServerHandler {
+    base_handler: Http3Connection,
+    events: Http3ServerConnEvents,
+    needs_processing: bool,
+}
+
+impl ::std::fmt::Display for Http3ServerHandler {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Http3 server connection")
+    }
+}
+
+impl Http3ServerHandler {
+    pub(crate) fn new(http3_parameters: Http3Parameters) -> Self {
+        Self {
+            base_handler: Http3Connection::new(http3_parameters, Role::Server),
+            events: Http3ServerConnEvents::default(),
+            needs_processing: false,
+        }
+    }
+
+    #[must_use]
+    pub fn state(&self) -> Http3State {
+        self.base_handler.state()
+    }
+
+    /// Supply a response for a request.
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist,
+    /// `AlreadyClosed` if the stream has already been closed.
+    /// `TransportStreamDoesNotExist` if the transport stream does not exist (this may happen if
+    /// `process_output` has not been called when needed, and HTTP3 layer has not picked up the
+    /// info that the stream has been closed.) `InvalidInput` if an empty buffer has been
+    /// supplied.
+    pub(crate) fn send_data(
+        &mut self,
+        stream_id: StreamId,
+        data: &[u8],
+        conn: &mut Connection,
+    ) -> Res<usize> {
+        self.base_handler.stream_has_pending_data(stream_id);
+        self.needs_processing = true;
+        self.base_handler
+            .send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .send_data(conn, data)
+    }
+
+    /// Supply response heeaders for a request.
+    pub(crate) fn send_headers(
+        &mut self,
+        stream_id: StreamId,
+        headers: &[Header],
+        conn: &mut Connection,
+    ) -> Res<()> {
+        self.base_handler
+            .send_streams
+            .get_mut(&stream_id)
+            .ok_or(Error::InvalidStreamId)?
+            .http_stream()
+            .ok_or(Error::InvalidStreamId)?
+            .send_headers(headers, conn)?;
+        self.base_handler.stream_has_pending_data(stream_id);
+        self.needs_processing = true;
+        Ok(())
+    }
+
+    /// This is called when application is done sending a request.
+    ///
+    /// # Errors
+    ///
+    /// An error will be returned if stream does not exist.
+    pub fn stream_close_send(&mut self, stream_id: StreamId, conn: &mut Connection) -> Res<()> {
+        qinfo!([self], "Close sending side stream={}.", stream_id);
+        self.base_handler.stream_close_send(conn, stream_id)?;
+        self.base_handler.stream_has_pending_data(stream_id);
+        self.needs_processing = true;
+        Ok(())
+    }
+
+    /// An application may reset a stream(request).
+    /// Both sides, sending and receiving side, will be closed.
+    ///
+    /// # Errors
+    ///
+    /// An error will be return if a stream does not exist.
+    pub fn cancel_fetch(
+        &mut self,
+        stream_id: StreamId,
+        error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!([self], "cancel_fetch {} error={}.", stream_id, error);
+        self.needs_processing = true;
+        self.base_handler.cancel_fetch(stream_id, error, conn)
+    }
+
+    pub fn stream_stop_sending(
+        &mut self,
+        stream_id: StreamId,
+        error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!([self], "stream_stop_sending {} error={}.", stream_id, error);
+        self.needs_processing = true;
+        self.base_handler
+            .stream_stop_sending(conn, stream_id, error)
+    }
+
+    pub fn stream_reset_send(
+        &mut self,
+        stream_id: StreamId,
+        error: AppError,
+        conn: &mut Connection,
+    ) -> Res<()> {
+        qinfo!([self], "stream_reset_send {} error={}.", stream_id, error);
+        self.needs_processing = true;
+        self.base_handler.stream_reset_send(conn, stream_id, error)
+    }
+
+    /// Accept a `WebTransport` Session request
+    pub(crate) fn webtransport_session_accept(
+        &mut self,
+        conn: &mut Connection,
+        stream_id: StreamId,
+        accept: &WebTransportSessionAcceptAction,
+    ) -> Res<()> {
+        self.needs_processing = true;
+        self.base_handler.webtransport_session_accept(
+            conn,
+            stream_id,
+            Box::new(self.events.clone()),
+            accept,
+        )
+    }
+
+    /// Close `WebTransport` cleanly
+    ///
+    /// # Errors
+    ///
+    /// `InvalidStreamId` if the stream does not exist,
+    /// `TransportStreamDoesNotExist` if the transport stream does not exist (this may happen if
+    /// `process_output` has not been called when needed, and HTTP3 layer has not picked up the
+    /// info that the stream has been closed.) `InvalidInput` if an empty buffer has been
+    /// supplied.
+    pub fn webtransport_close_session(
+        &mut self,
+        conn: &mut Connection,
+        session_id: StreamId,
+        error: u32,
+        message: &str,
+    ) -> Res<()> {
+        self.needs_processing = true;
+        self.base_handler
+            .webtransport_close_session(conn, session_id, error, message)
+    }
+
+    pub fn webtransport_create_stream(
+        &mut self,
+        conn: &mut Connection,
+        session_id: StreamId,
+        stream_type: StreamType,
+    ) -> Res<StreamId> {
+        self.needs_processing = true;
+        self.base_handler.webtransport_create_stream_local(
+            conn,
+            session_id,
+            stream_type,
+            Box::new(self.events.clone()),
+            Box::new(self.events.clone()),
+        )
+    }
+
+    pub fn webtransport_send_datagram(
+        &mut self,
+        conn: &mut Connection,
+        session_id: StreamId,
+        buf: &[u8],
+        id: impl Into<DatagramTracking>,
+    ) -> Res<()> {
+        self.needs_processing = true;
+        self.base_handler
+            .webtransport_send_datagram(session_id, conn, buf, id)
+    }
+
+    /// Process HTTTP3 layer.
+    pub fn process_http3(&mut self, conn: &mut Connection, now: Instant) {
+        qtrace!([self], "Process http3 internal.");
+        if matches!(self.base_handler.state(), Http3State::Closed(..)) {
+            return;
+        }
+
+        let res = self.check_connection_events(conn, now);
+        if !self.check_result(conn, now, &res) && self.base_handler.state().active() {
+            let res = self.base_handler.process_sending(conn);
+            self.check_result(conn, now, &res);
+        }
+    }
+
+    /// Take the next available event.
+    pub(crate) fn next_event(&mut self) -> Option<Http3ServerConnEvent> {
+        self.events.next_event()
+    }
+
+    /// Whether this connection has events to process or data to send.
+    pub(crate) fn should_be_processed(&mut self) -> bool {
+        if self.needs_processing {
+            self.needs_processing = false;
+            return true;
+        }
+        self.base_handler.has_data_to_send() || self.events.has_events()
+    }
+
+    // This function takes the provided result and check for an error.
+    // An error results in closing the connection.
+    fn check_result<ERR>(&mut self, conn: &mut Connection, now: Instant, res: &Res<ERR>) -> bool {
+        match &res {
+            Err(e) => {
+                self.close(conn, now, e);
+                true
+            }
+            _ => false,
+        }
+    }
+
+    fn close(&mut self, conn: &mut Connection, now: Instant, err: &Error) {
+        qinfo!([self], "Connection error: {}.", err);
+        conn.close(now, err.code(), &format!("{err}"));
+        self.base_handler.close(err.code());
+        self.events
+            .connection_state_change(self.base_handler.state());
+    }
+
+    // If this return an error the connection must be closed.
+    fn check_connection_events(&mut self, conn: &mut Connection, now: Instant) -> Res<()> {
+        qtrace!([self], "Check connection events.");
+        while let Some(e) = conn.next_event() {
+            qdebug!([self], "check_connection_events - event {e:?}.");
+            match e {
+                ConnectionEvent::NewStream { stream_id } => {
+                    self.base_handler.add_new_stream(stream_id);
+                }
+                ConnectionEvent::RecvStreamReadable { stream_id } => {
+                    self.handle_stream_readable(conn, stream_id)?;
+                }
+                ConnectionEvent::RecvStreamReset {
+                    stream_id,
+                    app_error,
+                } => {
+                    self.base_handler
+                        .handle_stream_reset(stream_id, app_error, conn)?;
+                }
+                ConnectionEvent::SendStreamStopSending {
+                    stream_id,
+                    app_error,
+                } => self
+                    .base_handler
+                    .handle_stream_stop_sending(stream_id, app_error, conn)?,
+                ConnectionEvent::StateChange(state) => {
+                    if self.base_handler.handle_state_change(conn, &state)? {
+                        if self.base_handler.state() == Http3State::Connected {
+                            let settings = self.base_handler.save_settings();
+                            conn.send_ticket(now, &settings)?;
+                        }
+                        self.events
+                            .connection_state_change(self.base_handler.state());
+                    }
+                }
+                ConnectionEvent::SendStreamWritable { stream_id } => {
+                    if let Some(s) = self.base_handler.send_streams.get_mut(&stream_id) {
+                        s.stream_writable();
+                    }
+                }
+                ConnectionEvent::Datagram(dgram) => self.base_handler.handle_datagram(&dgram),
+                ConnectionEvent::AuthenticationNeeded
+                | ConnectionEvent::EchFallbackAuthenticationNeeded { .. }
+                | ConnectionEvent::ZeroRttRejected
+                | ConnectionEvent::ResumptionToken(..) => return Err(Error::HttpInternal(4)),
+                ConnectionEvent::SendStreamComplete { .. }
+                | ConnectionEvent::SendStreamCreatable { .. }
+                | ConnectionEvent::OutgoingDatagramOutcome { .. }
+                | ConnectionEvent::IncomingDatagramDropped => {}
+            }
+        }
+        Ok(())
+    }
+
+    fn handle_stream_readable(&mut self, conn: &mut Connection, stream_id: StreamId) -> Res<()> {
+        match self.base_handler.handle_stream_readable(conn, stream_id)? {
+            ReceiveOutput::NewStream(NewStreamType::Push(_)) => Err(Error::HttpStreamCreation),
+            ReceiveOutput::NewStream(NewStreamType::Http) => {
+                self.base_handler.add_streams(
+                    stream_id,
+                    Box::new(SendMessage::new(
+                        MessageType::Response,
+                        Http3StreamType::Http,
+                        stream_id,
+                        self.base_handler.qpack_encoder.clone(),
+                        Box::new(self.events.clone()),
+                    )),
+                    Box::new(RecvMessage::new(
+                        &RecvMessageInfo {
+                            message_type: MessageType::Request,
+                            stream_type: Http3StreamType::Http,
+                            stream_id,
+                            header_frame_type_read: true,
+                        },
+                        Rc::clone(&self.base_handler.qpack_decoder),
+                        Box::new(self.events.clone()),
+                        None,
+                        PriorityHandler::new(false, Priority::default()),
+                    )),
+                );
+                let res = self.base_handler.handle_stream_readable(conn, stream_id)?;
+                assert_eq!(ReceiveOutput::NoOutput, res);
+                Ok(())
+            }
+            ReceiveOutput::NewStream(NewStreamType::WebTransportStream(session_id)) => {
+                self.base_handler.webtransport_create_stream_remote(
+                    StreamId::from(session_id),
+                    stream_id,
+                    Box::new(self.events.clone()),
+                    Box::new(self.events.clone()),
+                )?;
+                let res = self.base_handler.handle_stream_readable(conn, stream_id)?;
+                assert_eq!(ReceiveOutput::NoOutput, res);
+                Ok(())
+            }
+            ReceiveOutput::ControlFrames(control_frames) => {
+                for f in control_frames {
+                    match f {
+                        HFrame::MaxPushId { .. } => {
+                            // TODO implement push
+                            Ok(())
+                        }
+                        HFrame::Goaway { .. } | HFrame::CancelPush { .. } => {
+                            Err(Error::HttpFrameUnexpected)
+                        }
+                        HFrame::PriorityUpdatePush { element_id, priority } => {
+                            // TODO: check if the element_id references a promised push stream or
+                            // is greater than the maximum Push ID.
+                            self.events.priority_update(StreamId::from(element_id), priority);
+                            Ok(())
+                        }
+                        HFrame::PriorityUpdateRequest { element_id, priority } => {
+                            // check that the element_id references a request stream
+                            // within the client-sided bidirectional stream limit
+                            let element_stream_id = StreamId::new(element_id);
+                            if !element_stream_id.is_bidi()
+                                || !element_stream_id.is_client_initiated()
+                                || !conn.is_stream_id_allowed(element_stream_id)
+                            {
+                                return Err(Error::HttpId)
+                            }
+
+                            self.events.priority_update(element_stream_id, priority);
+                            Ok(())
+                        }
+                        _ => unreachable!(
+                            "we should only put MaxPushId, Goaway and PriorityUpdates into control_frames."
+                        ),
+                    }?;
+                }
+                Ok(())
+            }
+            _ => Ok(()),
+        }
+    }
+
+    /// Response data are read directly into a buffer supplied as a parameter of this function to
+    /// avoid copying data.
+    ///
+    /// # Errors
+    ///
+    /// It returns an error if a stream does not exist or an error happen while reading a stream,
+    /// e.g. early close, protocol error, etc.
+    pub fn read_data(
+        &mut self,
+        conn: &mut Connection,
+        now: Instant,
+        stream_id: StreamId,
+        buf: &mut [u8],
+    ) -> Res<(usize, bool)> {
+        qinfo!([self], "read_data from stream {}.", stream_id);
+        let res = self.base_handler.read_data(conn, stream_id, buf);
+        if let Err(e) = &res {
+            if e.connection_error() {
+                self.close(conn, now, e);
+            }
+        }
+        res
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/control_stream_local.rs b/third_party/rust/neqo-http3/src/control_stream_local.rs
new file mode 100644
index 0000000000..62676ee391
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/control_stream_local.rs
@@ -0,0 +1,109 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{
+    collections::{HashMap, VecDeque},
+    convert::TryFrom,
+};
+
+use neqo_common::{qtrace, Encoder};
+use neqo_transport::{Connection, StreamId, StreamType};
+
+use crate::{frames::HFrame, BufferedStream, Http3StreamType, RecvStream, Res};
+
+pub const HTTP3_UNI_STREAM_TYPE_CONTROL: u64 = 0x0;
+
+/// The local control stream, responsible for encoding frames and sending them
+#[derive(Debug)]
+pub(crate) struct ControlStreamLocal {
+    stream: BufferedStream,
+    /// `stream_id`s of outstanding request streams
+    outstanding_priority_update: VecDeque<StreamId>,
+}
+
+impl ::std::fmt::Display for ControlStreamLocal {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Local control stream {:?}", self.stream)
+    }
+}
+
+impl ControlStreamLocal {
+    pub fn new() -> Self {
+        Self {
+            stream: BufferedStream::default(),
+            outstanding_priority_update: VecDeque::new(),
+        }
+    }
+
+    /// Add a new frame that needs to be send.
+    pub fn queue_frame(&mut self, f: &HFrame) {
+        let mut enc = Encoder::default();
+        f.encode(&mut enc);
+        self.stream.buffer(enc.as_ref());
+    }
+
+    pub fn queue_update_priority(&mut self, stream_id: StreamId) {
+        self.outstanding_priority_update.push_back(stream_id);
+    }
+
+    /// Send control data if available.
+    pub fn send(
+        &mut self,
+        conn: &mut Connection,
+        recv_conn: &mut HashMap<StreamId, Box<dyn RecvStream>>,
+    ) -> Res<()> {
+        self.stream.send_buffer(conn)?;
+        self.send_priority_update(conn, recv_conn)
+    }
+
+    fn send_priority_update(
+        &mut self,
+        conn: &mut Connection,
+        recv_conn: &mut HashMap<StreamId, Box<dyn RecvStream>>,
+    ) -> Res<()> {
+        // send all necessary priority updates
+        while let Some(update_id) = self.outstanding_priority_update.pop_front() {
+            let Some(update_stream) = recv_conn.get_mut(&update_id) else {
+                continue;
+            };
+
+            // can assert and unwrap here, because priority updates can only be added to
+            // HttpStreams in [Http3Connection::queue_update_priority}
+            debug_assert!(matches!(
+                update_stream.stream_type(),
+                Http3StreamType::Http | Http3StreamType::Push
+            ));
+            let stream = update_stream.http_stream().unwrap();
+
+            // in case multiple priority_updates were issued, ignore now irrelevant
+            if let Some(hframe) = stream.priority_update_frame() {
+                let mut enc = Encoder::new();
+                hframe.encode(&mut enc);
+                if self.stream.send_atomic(conn, enc.as_ref())? {
+                    stream.priority_update_sent();
+                } else {
+                    self.outstanding_priority_update.push_front(update_id);
+                    break;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// Create a control stream.
+    pub fn create(&mut self, conn: &mut Connection) -> Res<()> {
+        qtrace!([self], "Create a control stream.");
+        self.stream.init(conn.stream_create(StreamType::UniDi)?);
+        self.stream
+            .buffer(&[u8::try_from(HTTP3_UNI_STREAM_TYPE_CONTROL).unwrap()]);
+        Ok(())
+    }
+
+    #[must_use]
+    pub fn stream_id(&self) -> Option<StreamId> {
+        (&self.stream).into()
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/control_stream_remote.rs b/third_party/rust/neqo-http3/src/control_stream_remote.rs
new file mode 100644
index 0000000000..aef4b4c0a4
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/control_stream_remote.rs
@@ -0,0 +1,78 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use neqo_common::qdebug;
+use neqo_transport::{Connection, StreamId};
+
+use crate::{
+    frames::{FrameReader, HFrame, StreamReaderConnectionWrapper},
+    CloseType, Error, Http3StreamType, ReceiveOutput, RecvStream, Res, Stream,
+};
+
+/// The remote control stream is responsible only for reading frames. The frames are handled by
+/// `Http3Connection`.
+#[derive(Debug)]
+pub(crate) struct ControlStreamRemote {
+    stream_id: StreamId,
+    frame_reader: FrameReader,
+}
+
+impl ::std::fmt::Display for ControlStreamRemote {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Http3 remote control stream {:?}", self.stream_id)
+    }
+}
+
+impl ControlStreamRemote {
+    pub fn new(stream_id: StreamId) -> Self {
+        Self {
+            stream_id,
+            frame_reader: FrameReader::new(),
+        }
+    }
+
+    /// Check if a stream is the control stream and read received data.
+    pub fn receive_single(&mut self, conn: &mut Connection) -> Res<Option<HFrame>> {
+        qdebug!([self], "Receiving data.");
+        match self
+            .frame_reader
+            .receive(&mut StreamReaderConnectionWrapper::new(
+                conn,
+                self.stream_id,
+            ))? {
+            (_, true) => Err(Error::HttpClosedCriticalStream),
+            (s, false) => {
+                qdebug!([self], "received {:?}", s);
+                Ok(s)
+            }
+        }
+    }
+}
+
+impl Stream for ControlStreamRemote {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::Control
+    }
+}
+
+impl RecvStream for ControlStreamRemote {
+    fn reset(&mut self, _close_type: CloseType) -> Res<()> {
+        Err(Error::HttpClosedCriticalStream)
+    }
+
+    #[allow(clippy::vec_init_then_push)] // Clippy fail.
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        let mut control_frames = Vec::new();
+
+        loop {
+            if let Some(f) = self.receive_single(conn)? {
+                control_frames.push(f);
+            } else {
+                return Ok((ReceiveOutput::ControlFrames(control_frames), false));
+            }
+        }
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/mod.rs b/third_party/rust/neqo-http3/src/features/extended_connect/mod.rs
new file mode 100644
index 0000000000..77655833f7
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/mod.rs
@@ -0,0 +1,118 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+pub(crate) mod webtransport_session;
+pub(crate) mod webtransport_streams;
+
+use std::fmt::Debug;
+
+use neqo_common::Header;
+use neqo_transport::{AppError, StreamId};
+pub(crate) use webtransport_session::WebTransportSession;
+
+use crate::{
+    client_events::Http3ClientEvents,
+    features::NegotiationState,
+    settings::{HSettingType, HSettings},
+    CloseType, Http3StreamInfo, Http3StreamType,
+};
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum SessionCloseReason {
+    Error(AppError),
+    Status(u16),
+    Clean { error: u32, message: String },
+}
+
+impl From<CloseType> for SessionCloseReason {
+    fn from(close_type: CloseType) -> SessionCloseReason {
+        match close_type {
+            CloseType::ResetApp(e) | CloseType::ResetRemote(e) | CloseType::LocalError(e) => {
+                SessionCloseReason::Error(e)
+            }
+            CloseType::Done => SessionCloseReason::Clean {
+                error: 0,
+                message: String::new(),
+            },
+        }
+    }
+}
+
+pub(crate) trait ExtendedConnectEvents: Debug {
+    fn session_start(
+        &self,
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        status: u16,
+        headers: Vec<Header>,
+    );
+    fn session_end(
+        &self,
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    );
+    fn extended_connect_new_stream(&self, stream_info: Http3StreamInfo);
+    fn new_datagram(&self, session_id: StreamId, datagram: Vec<u8>);
+}
+
+#[derive(Debug, PartialEq, Copy, Clone, Eq)]
+pub(crate) enum ExtendedConnectType {
+    WebTransport,
+}
+
+impl ExtendedConnectType {
+    #[must_use]
+    #[allow(clippy::unused_self)] // This will change when we have more features using ExtendedConnectType.
+    pub fn string(&self) -> &str {
+        "webtransport"
+    }
+
+    #[allow(clippy::unused_self)] // This will change when we have more features using ExtendedConnectType.
+    #[must_use]
+    pub fn get_stream_type(self, session_id: StreamId) -> Http3StreamType {
+        Http3StreamType::WebTransport(session_id)
+    }
+}
+
+impl From<ExtendedConnectType> for HSettingType {
+    fn from(_type: ExtendedConnectType) -> Self {
+        // This will change when we have more features using ExtendedConnectType.
+        HSettingType::EnableWebTransport
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct ExtendedConnectFeature {
+    feature_negotiation: NegotiationState,
+}
+
+impl ExtendedConnectFeature {
+    #[must_use]
+    pub fn new(connect_type: ExtendedConnectType, enable: bool) -> Self {
+        Self {
+            feature_negotiation: NegotiationState::new(enable, HSettingType::from(connect_type)),
+        }
+    }
+
+    pub fn set_listener(&mut self, new_listener: Http3ClientEvents) {
+        self.feature_negotiation.set_listener(new_listener);
+    }
+
+    pub fn handle_settings(&mut self, settings: &HSettings) {
+        self.feature_negotiation.handle_settings(settings);
+    }
+
+    #[must_use]
+    pub fn enabled(&self) -> bool {
+        self.feature_negotiation.enabled()
+    }
+}
+#[cfg(test)]
+mod tests;
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/mod.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/mod.rs
new file mode 100644
index 0000000000..a21f63dbf8
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/mod.rs
@@ -0,0 +1,7 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+mod webtransport;
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/datagrams.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/datagrams.rs
new file mode 100644
index 0000000000..1c58596dd3
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/datagrams.rs
@@ -0,0 +1,146 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::convert::TryFrom;
+
+use neqo_common::Encoder;
+use neqo_transport::Error as TransportError;
+
+use crate::{
+    features::extended_connect::tests::webtransport::{
+        wt_default_parameters, WtTest, DATAGRAM_SIZE,
+    },
+    Error, Http3Parameters, WebTransportRequest,
+};
+
+const DGRAM: &[u8] = &[0, 100];
+
+#[test]
+fn no_datagrams() {
+    let mut wt = WtTest::new_with_params(
+        Http3Parameters::default().webtransport(true),
+        Http3Parameters::default().webtransport(true),
+    );
+    let mut wt_session = wt.create_wt_session();
+
+    assert_eq!(
+        wt_session.max_datagram_size(),
+        Err(Error::TransportError(TransportError::NotAvailable))
+    );
+    assert_eq!(
+        wt.max_datagram_size(wt_session.stream_id()),
+        Err(Error::TransportError(TransportError::NotAvailable))
+    );
+
+    assert_eq!(
+        wt_session.send_datagram(DGRAM, None),
+        Err(Error::TransportError(TransportError::TooMuchData))
+    );
+    assert_eq!(
+        wt.send_datagram(wt_session.stream_id(), DGRAM),
+        Err(Error::TransportError(TransportError::TooMuchData))
+    );
+
+    wt.exchange_packets();
+    wt.check_no_datagram_received_client();
+    wt.check_no_datagram_received_server();
+}
+
+fn do_datagram_test(wt: &mut WtTest, wt_session: &mut WebTransportRequest) {
+    assert_eq!(
+        wt_session.max_datagram_size(),
+        Ok(DATAGRAM_SIZE
+            - u64::try_from(Encoder::varint_len(wt_session.stream_id().as_u64())).unwrap())
+    );
+    assert_eq!(
+        wt.max_datagram_size(wt_session.stream_id()),
+        Ok(DATAGRAM_SIZE
+            - u64::try_from(Encoder::varint_len(wt_session.stream_id().as_u64())).unwrap())
+    );
+
+    assert_eq!(wt_session.send_datagram(DGRAM, None), Ok(()));
+    assert_eq!(wt.send_datagram(wt_session.stream_id(), DGRAM), Ok(()));
+
+    wt.exchange_packets();
+    wt.check_datagram_received_client(wt_session.stream_id(), DGRAM);
+    wt.check_datagram_received_server(wt_session, DGRAM);
+}
+
+#[test]
+fn datagrams() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    do_datagram_test(&mut wt, &mut wt_session);
+}
+
+#[test]
+fn datagrams_server_only() {
+    let mut wt = WtTest::new_with_params(
+        Http3Parameters::default().webtransport(true),
+        wt_default_parameters(),
+    );
+    let mut wt_session = wt.create_wt_session();
+
+    assert_eq!(
+        wt_session.max_datagram_size(),
+        Err(Error::TransportError(TransportError::NotAvailable))
+    );
+    assert_eq!(
+        wt.max_datagram_size(wt_session.stream_id()),
+        Ok(DATAGRAM_SIZE
+            - u64::try_from(Encoder::varint_len(wt_session.stream_id().as_u64())).unwrap())
+    );
+
+    assert_eq!(
+        wt_session.send_datagram(DGRAM, None),
+        Err(Error::TransportError(TransportError::TooMuchData))
+    );
+    assert_eq!(wt.send_datagram(wt_session.stream_id(), DGRAM), Ok(()));
+
+    wt.exchange_packets();
+    wt.check_datagram_received_server(&wt_session, DGRAM);
+    wt.check_no_datagram_received_client();
+}
+
+#[test]
+fn datagrams_client_only() {
+    let mut wt = WtTest::new_with_params(
+        wt_default_parameters(),
+        Http3Parameters::default().webtransport(true),
+    );
+    let mut wt_session = wt.create_wt_session();
+
+    assert_eq!(
+        wt_session.max_datagram_size(),
+        Ok(DATAGRAM_SIZE
+            - u64::try_from(Encoder::varint_len(wt_session.stream_id().as_u64())).unwrap())
+    );
+    assert_eq!(
+        wt.max_datagram_size(wt_session.stream_id()),
+        Err(Error::TransportError(TransportError::NotAvailable))
+    );
+
+    assert_eq!(wt_session.send_datagram(DGRAM, None), Ok(()));
+    assert_eq!(
+        wt.send_datagram(wt_session.stream_id(), DGRAM),
+        Err(Error::TransportError(TransportError::TooMuchData))
+    );
+
+    wt.exchange_packets();
+    wt.check_datagram_received_client(wt_session.stream_id(), DGRAM);
+    wt.check_no_datagram_received_server();
+}
+
+#[test]
+fn datagrams_multiple_session() {
+    let mut wt = WtTest::new();
+
+    let mut wt_session1 = wt.create_wt_session();
+    do_datagram_test(&mut wt, &mut wt_session1);
+
+    let mut wt_session_2 = wt.create_wt_session();
+    do_datagram_test(&mut wt, &mut wt_session_2);
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/mod.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/mod.rs
new file mode 100644
index 0000000000..51dc47e4c1
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/mod.rs
@@ -0,0 +1,661 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+mod datagrams;
+mod negotiation;
+mod sessions;
+mod streams;
+use std::{cell::RefCell, rc::Rc, time::Duration};
+
+use neqo_common::event::Provider;
+use neqo_crypto::AuthenticationStatus;
+use neqo_transport::{ConnectionParameters, StreamId, StreamType};
+use test_fixture::{
+    addr, anti_replay, fixture_init, now, CountingConnectionIdGenerator, DEFAULT_ALPN_H3,
+    DEFAULT_KEYS, DEFAULT_SERVER_NAME,
+};
+
+use crate::{
+    features::extended_connect::SessionCloseReason, Error, Header, Http3Client, Http3ClientEvent,
+    Http3OrWebTransportStream, Http3Parameters, Http3Server, Http3ServerEvent, Http3State,
+    RecvStreamStats, SendStreamStats, WebTransportEvent, WebTransportRequest,
+    WebTransportServerEvent, WebTransportSessionAcceptAction,
+};
+
+const DATAGRAM_SIZE: u64 = 1200;
+
+pub fn wt_default_parameters() -> Http3Parameters {
+    Http3Parameters::default()
+        .webtransport(true)
+        .connection_parameters(ConnectionParameters::default().datagram_size(DATAGRAM_SIZE))
+}
+
+pub fn default_http3_client(client_params: Http3Parameters) -> Http3Client {
+    fixture_init();
+    Http3Client::new(
+        DEFAULT_SERVER_NAME,
+        Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+        addr(),
+        addr(),
+        client_params,
+        now(),
+    )
+    .expect("create a default client")
+}
+
+pub fn default_http3_server(server_params: Http3Parameters) -> Http3Server {
+    Http3Server::new(
+        now(),
+        DEFAULT_KEYS,
+        DEFAULT_ALPN_H3,
+        anti_replay(),
+        Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+        server_params,
+        None,
+    )
+    .expect("create a server")
+}
+
+fn exchange_packets(client: &mut Http3Client, server: &mut Http3Server) {
+    let mut out = None;
+    loop {
+        out = client.process(out.as_ref(), now()).dgram();
+        out = server.process(out.as_ref(), now()).dgram();
+        if out.is_none() {
+            break;
+        }
+    }
+}
+
+// Perform only Quic transport handshake.
+fn connect_with(client: &mut Http3Client, server: &mut Http3Server) {
+    assert_eq!(client.state(), Http3State::Initializing);
+    let out = client.process(None, now());
+    assert_eq!(client.state(), Http3State::Initializing);
+
+    let out = server.process(out.as_dgram_ref(), now());
+    let out = client.process(out.as_dgram_ref(), now());
+    let out = server.process(out.as_dgram_ref(), now());
+    assert!(out.as_dgram_ref().is_none());
+
+    let authentication_needed = |e| matches!(e, Http3ClientEvent::AuthenticationNeeded);
+    assert!(client.events().any(authentication_needed));
+    client.authenticated(AuthenticationStatus::Ok, now());
+
+    let out = client.process(out.as_dgram_ref(), now());
+    let connected = |e| matches!(e, Http3ClientEvent::StateChange(Http3State::Connected));
+    assert!(client.events().any(connected));
+
+    assert_eq!(client.state(), Http3State::Connected);
+
+    // Exchange H3 setttings
+    let out = server.process(out.as_dgram_ref(), now());
+    let out = client.process(out.as_dgram_ref(), now());
+    let out = server.process(out.as_dgram_ref(), now());
+    let out = client.process(out.as_dgram_ref(), now());
+    let out = server.process(out.as_dgram_ref(), now());
+    std::mem::drop(client.process(out.as_dgram_ref(), now()));
+}
+
+fn connect(
+    client_params: Http3Parameters,
+    server_params: Http3Parameters,
+) -> (Http3Client, Http3Server) {
+    let mut client = default_http3_client(client_params);
+    let mut server = default_http3_server(server_params);
+    connect_with(&mut client, &mut server);
+    (client, server)
+}
+
+struct WtTest {
+    client: Http3Client,
+    server: Http3Server,
+}
+
+impl WtTest {
+    pub fn new() -> Self {
+        let (client, server) = connect(wt_default_parameters(), wt_default_parameters());
+        Self { client, server }
+    }
+
+    pub fn new_with_params(client_params: Http3Parameters, server_params: Http3Parameters) -> Self {
+        let (client, server) = connect(client_params, server_params);
+        Self { client, server }
+    }
+
+    pub fn new_with(mut client: Http3Client, mut server: Http3Server) -> Self {
+        connect_with(&mut client, &mut server);
+        Self { client, server }
+    }
+    fn negotiate_wt_session(
+        &mut self,
+        accept: &WebTransportSessionAcceptAction,
+    ) -> (StreamId, Option<WebTransportRequest>) {
+        let wt_session_id = self
+            .client
+            .webtransport_create_session(now(), &("https", "something.com", "/"), &[])
+            .unwrap();
+        self.exchange_packets();
+
+        let mut wt_server_session = None;
+        while let Some(event) = self.server.next_event() {
+            match event {
+                Http3ServerEvent::WebTransport(WebTransportServerEvent::NewSession {
+                    mut session,
+                    headers,
+                }) => {
+                    assert!(
+                        headers
+                            .iter()
+                            .any(|h| h.name() == ":method" && h.value() == "CONNECT")
+                            && headers
+                                .iter()
+                                .any(|h| h.name() == ":protocol" && h.value() == "webtransport")
+                    );
+                    session.response(accept).unwrap();
+                    wt_server_session = Some(session);
+                }
+                Http3ServerEvent::Data { .. } => {
+                    panic!("There should not be any data events!");
+                }
+                _ => {}
+            }
+        }
+
+        self.exchange_packets();
+        (wt_session_id, wt_server_session)
+    }
+
+    fn create_wt_session(&mut self) -> WebTransportRequest {
+        let (wt_session_id, wt_server_session) =
+            self.negotiate_wt_session(&WebTransportSessionAcceptAction::Accept);
+        let wt_session_negotiated_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::WebTransport(WebTransportEvent::Session{
+                    stream_id,
+                    status,
+                    headers,
+                }) if (
+                    stream_id == wt_session_id &&
+                    status == 200 &&
+                    headers.contains(&Header::new(":status", "200"))
+                )
+            )
+        };
+        assert!(self.client.events().any(wt_session_negotiated_event));
+
+        let wt_server_session = wt_server_session.unwrap();
+        assert_eq!(wt_session_id, wt_server_session.stream_id());
+        wt_server_session
+    }
+
+    fn exchange_packets(&mut self) {
+        const RTT: Duration = Duration::from_millis(10);
+        let mut out = None;
+        let mut now = now();
+        loop {
+            now += RTT / 2;
+            out = self.client.process(out.as_ref(), now).dgram();
+            let client_none = out.is_none();
+            now += RTT / 2;
+            out = self.server.process(out.as_ref(), now).dgram();
+            if client_none && out.is_none() {
+                break;
+            }
+        }
+    }
+
+    pub fn cancel_session_client(&mut self, wt_stream_id: StreamId) {
+        self.client
+            .cancel_fetch(wt_stream_id, Error::HttpNoError.code())
+            .unwrap();
+        self.exchange_packets();
+    }
+
+    fn session_closed_client(
+        e: &Http3ClientEvent,
+        id: StreamId,
+        expected_reason: &SessionCloseReason,
+        expected_headers: &Option<Vec<Header>>,
+    ) -> bool {
+        if let Http3ClientEvent::WebTransport(WebTransportEvent::SessionClosed {
+            stream_id,
+            reason,
+            headers,
+        }) = e
+        {
+            *stream_id == id && reason == expected_reason && headers == expected_headers
+        } else {
+            false
+        }
+    }
+
+    pub fn check_session_closed_event_client(
+        &mut self,
+        wt_session_id: StreamId,
+        expected_reason: &SessionCloseReason,
+        expected_headers: &Option<Vec<Header>>,
+    ) {
+        let mut event_found = false;
+
+        while let Some(event) = self.client.next_event() {
+            event_found = WtTest::session_closed_client(
+                &event,
+                wt_session_id,
+                expected_reason,
+                expected_headers,
+            );
+            if event_found {
+                break;
+            }
+        }
+        assert!(event_found);
+    }
+
+    pub fn cancel_session_server(&mut self, wt_session: &mut WebTransportRequest) {
+        wt_session.cancel_fetch(Error::HttpNoError.code()).unwrap();
+        self.exchange_packets();
+    }
+
+    fn session_closed_server(
+        e: &Http3ServerEvent,
+        id: StreamId,
+        expected_reason: &SessionCloseReason,
+    ) -> bool {
+        if let Http3ServerEvent::WebTransport(WebTransportServerEvent::SessionClosed {
+            session,
+            reason,
+            headers,
+        }) = e
+        {
+            session.stream_id() == id && reason == expected_reason && headers.is_none()
+        } else {
+            false
+        }
+    }
+
+    pub fn check_session_closed_event_server(
+        &mut self,
+        wt_session: &mut WebTransportRequest,
+        expected_reeason: &SessionCloseReason,
+    ) {
+        let event = self.server.next_event().unwrap();
+        assert!(WtTest::session_closed_server(
+            &event,
+            wt_session.stream_id(),
+            expected_reeason
+        ));
+    }
+
+    fn create_wt_stream_client(
+        &mut self,
+        wt_session_id: StreamId,
+        stream_type: StreamType,
+    ) -> StreamId {
+        self.client
+            .webtransport_create_stream(wt_session_id, stream_type)
+            .unwrap()
+    }
+
+    fn send_data_client(&mut self, wt_stream_id: StreamId, data: &[u8]) {
+        assert_eq!(
+            self.client.send_data(wt_stream_id, data).unwrap(),
+            data.len()
+        );
+        self.exchange_packets();
+    }
+
+    fn send_stream_stats(&mut self, wt_stream_id: StreamId) -> Result<SendStreamStats, Error> {
+        self.client.webtransport_send_stream_stats(wt_stream_id)
+    }
+
+    fn recv_stream_stats(&mut self, wt_stream_id: StreamId) -> Result<RecvStreamStats, Error> {
+        self.client.webtransport_recv_stream_stats(wt_stream_id)
+    }
+
+    fn receive_data_client(
+        &mut self,
+        expected_stream_id: StreamId,
+        new_stream: bool,
+        expected_data: &[u8],
+        expected_fin: bool,
+    ) {
+        let mut new_stream_received = false;
+        let mut data_received = false;
+        while let Some(event) = self.client.next_event() {
+            match event {
+                Http3ClientEvent::WebTransport(WebTransportEvent::NewStream {
+                    stream_id, ..
+                }) => {
+                    assert_eq!(stream_id, expected_stream_id);
+                    new_stream_received = true;
+                }
+                Http3ClientEvent::DataReadable { stream_id } => {
+                    assert_eq!(stream_id, expected_stream_id);
+                    let mut buf = [0; 100];
+                    let (amount, fin) = self.client.read_data(now(), stream_id, &mut buf).unwrap();
+                    assert_eq!(fin, expected_fin);
+                    assert_eq!(amount, expected_data.len());
+                    assert_eq!(&buf[..amount], expected_data);
+                    data_received = true;
+                }
+                _ => {}
+            }
+        }
+        assert!(data_received);
+        assert_eq!(new_stream, new_stream_received);
+    }
+
+    fn close_stream_sending_client(&mut self, wt_stream_id: StreamId) {
+        self.client.stream_close_send(wt_stream_id).unwrap();
+        self.exchange_packets();
+    }
+
+    fn reset_stream_client(&mut self, wt_stream_id: StreamId) {
+        self.client
+            .stream_reset_send(wt_stream_id, Error::HttpNoError.code())
+            .unwrap();
+        self.exchange_packets();
+    }
+
+    fn receive_reset_client(&mut self, expected_stream_id: StreamId) {
+        let wt_reset_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local
+                } if stream_id == expected_stream_id && error == Error::HttpNoError.code() && !local
+            )
+        };
+        assert!(self.client.events().any(wt_reset_event));
+    }
+
+    fn stream_stop_sending_client(&mut self, stream_id: StreamId) {
+        self.client
+            .stream_stop_sending(stream_id, Error::HttpNoError.code())
+            .unwrap();
+        self.exchange_packets();
+    }
+
+    fn receive_stop_sending_client(&mut self, expected_stream_id: StreamId) {
+        let wt_stop_sending_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::StopSending {
+                    stream_id,
+                    error
+                } if stream_id == expected_stream_id && error == Error::HttpNoError.code()
+            )
+        };
+        assert!(self.client.events().any(wt_stop_sending_event));
+    }
+
+    fn check_events_after_closing_session_client(
+        &mut self,
+        expected_reset_ids: &[StreamId],
+        expected_error_stream_reset: Option<u64>,
+        expected_stop_sending_ids: &[StreamId],
+        expected_error_stream_stop_sending: Option<u64>,
+        expected_local: bool,
+        expected_session_close: &Option<(StreamId, SessionCloseReason)>,
+    ) {
+        let mut reset_ids_count = 0;
+        let mut stop_sending_ids_count = 0;
+        let mut close_event = false;
+        while let Some(event) = self.client.next_event() {
+            match event {
+                Http3ClientEvent::Reset {
+                    stream_id,
+                    error,
+                    local,
+                } => {
+                    assert!(expected_reset_ids.contains(&stream_id));
+                    assert_eq!(expected_error_stream_reset.unwrap(), error);
+                    assert_eq!(expected_local, local);
+                    reset_ids_count += 1;
+                }
+                Http3ClientEvent::StopSending { stream_id, error } => {
+                    assert!(expected_stop_sending_ids.contains(&stream_id));
+                    assert_eq!(expected_error_stream_stop_sending.unwrap(), error);
+                    stop_sending_ids_count += 1;
+                }
+                Http3ClientEvent::WebTransport(WebTransportEvent::SessionClosed {
+                    stream_id,
+                    reason,
+                    headers,
+                }) => {
+                    close_event = true;
+                    assert_eq!(stream_id, expected_session_close.as_ref().unwrap().0);
+                    assert_eq!(expected_session_close.as_ref().unwrap().1, reason);
+                    assert!(headers.is_none());
+                }
+                _ => {}
+            }
+        }
+        assert_eq!(reset_ids_count, expected_reset_ids.len());
+        assert_eq!(stop_sending_ids_count, expected_stop_sending_ids.len());
+        assert_eq!(close_event, expected_session_close.is_some());
+    }
+
+    fn create_wt_stream_server(
+        wt_server_session: &mut WebTransportRequest,
+        stream_type: StreamType,
+    ) -> Http3OrWebTransportStream {
+        wt_server_session.create_stream(stream_type).unwrap()
+    }
+
+    fn send_data_server(&mut self, wt_stream: &mut Http3OrWebTransportStream, data: &[u8]) {
+        assert_eq!(wt_stream.send_data(data).unwrap(), data.len());
+        self.exchange_packets();
+    }
+
+    fn receive_data_server(
+        &mut self,
+        stream_id: StreamId,
+        new_stream: bool,
+        expected_data: &[u8],
+        expected_fin: bool,
+    ) -> Http3OrWebTransportStream {
+        self.exchange_packets();
+        let mut new_stream_received = false;
+        let mut data_received = false;
+        let mut wt_stream = None;
+        let mut stream_closed = false;
+        let mut recv_data = Vec::new();
+        while let Some(event) = self.server.next_event() {
+            match event {
+                Http3ServerEvent::WebTransport(WebTransportServerEvent::NewStream(request)) => {
+                    assert_eq!(stream_id, request.stream_id());
+                    new_stream_received = true;
+                }
+                Http3ServerEvent::Data {
+                    mut data,
+                    fin,
+                    stream,
+                } => {
+                    recv_data.append(&mut data);
+                    stream_closed = fin;
+                    data_received = true;
+                    wt_stream = Some(stream);
+                }
+                _ => {}
+            }
+        }
+        assert_eq!(&recv_data[..], expected_data);
+        assert!(data_received);
+        assert_eq!(new_stream, new_stream_received);
+        assert_eq!(stream_closed, expected_fin);
+        wt_stream.unwrap()
+    }
+
+    fn close_stream_sending_server(&mut self, wt_stream: &mut Http3OrWebTransportStream) {
+        wt_stream.stream_close_send().unwrap();
+        self.exchange_packets();
+    }
+
+    fn reset_stream_server(&mut self, wt_stream: &mut Http3OrWebTransportStream) {
+        wt_stream
+            .stream_reset_send(Error::HttpNoError.code())
+            .unwrap();
+        self.exchange_packets();
+    }
+
+    fn stream_stop_sending_server(&mut self, wt_stream: &mut Http3OrWebTransportStream) {
+        wt_stream
+            .stream_stop_sending(Error::HttpNoError.code())
+            .unwrap();
+        self.exchange_packets();
+    }
+
+    fn receive_reset_server(&mut self, expected_stream_id: StreamId, expected_error: u64) {
+        let stream_reset = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::StreamReset {
+                    stream,
+                    error
+                } if stream.stream_id() == expected_stream_id && error == expected_error
+            )
+        };
+        assert!(self.server.events().any(stream_reset));
+    }
+
+    fn receive_stop_sending_server(&mut self, expected_stream_id: StreamId, expected_error: u64) {
+        let stop_sending = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::StreamStopSending {
+                    stream,
+                    error
+                } if stream.stream_id() == expected_stream_id && error == expected_error
+            )
+        };
+        assert!(self.server.events().any(stop_sending));
+    }
+
+    fn check_events_after_closing_session_server(
+        &mut self,
+        expected_reset_ids: &[StreamId],
+        expected_error_stream_reset: Option<u64>,
+        expected_stop_sending_ids: &[StreamId],
+        expected_error_stream_stop_sending: Option<u64>,
+        expected_session_close: &Option<(StreamId, SessionCloseReason)>,
+    ) {
+        let mut reset_ids_count = 0;
+        let mut stop_sending_ids_count = 0;
+        let mut close_event = false;
+        while let Some(event) = self.server.next_event() {
+            match event {
+                Http3ServerEvent::StreamReset { stream, error } => {
+                    assert!(expected_reset_ids.contains(&stream.stream_id()));
+                    assert_eq!(expected_error_stream_reset.unwrap(), error);
+                    reset_ids_count += 1;
+                }
+                Http3ServerEvent::StreamStopSending { stream, error } => {
+                    assert!(expected_stop_sending_ids.contains(&stream.stream_id()));
+                    assert_eq!(expected_error_stream_stop_sending.unwrap(), error);
+                    stop_sending_ids_count += 1;
+                }
+                Http3ServerEvent::WebTransport(WebTransportServerEvent::SessionClosed {
+                    session,
+                    reason,
+                    headers,
+                }) => {
+                    close_event = true;
+                    assert_eq!(
+                        session.stream_id(),
+                        expected_session_close.as_ref().unwrap().0
+                    );
+                    assert_eq!(expected_session_close.as_ref().unwrap().1, reason);
+                    assert!(headers.is_none());
+                }
+                _ => {}
+            }
+        }
+        assert_eq!(reset_ids_count, expected_reset_ids.len());
+        assert_eq!(stop_sending_ids_count, expected_stop_sending_ids.len());
+        assert_eq!(close_event, expected_session_close.is_some());
+    }
+
+    pub fn session_close_frame_client(&mut self, session_id: StreamId, error: u32, message: &str) {
+        self.client
+            .webtransport_close_session(session_id, error, message)
+            .unwrap();
+    }
+
+    pub fn session_close_frame_server(
+        wt_session: &mut WebTransportRequest,
+        error: u32,
+        message: &str,
+    ) {
+        wt_session.close_session(error, message).unwrap();
+    }
+
+    fn max_datagram_size(&self, stream_id: StreamId) -> Result<u64, Error> {
+        self.client.webtransport_max_datagram_size(stream_id)
+    }
+
+    fn send_datagram(&mut self, stream_id: StreamId, buf: &[u8]) -> Result<(), Error> {
+        self.client.webtransport_send_datagram(stream_id, buf, None)
+    }
+
+    fn check_datagram_received_client(
+        &mut self,
+        expected_stream_id: StreamId,
+        expected_dgram: &[u8],
+    ) {
+        let wt_datagram_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::WebTransport(WebTransportEvent::Datagram {
+                    session_id,
+                    datagram
+                }) if session_id == expected_stream_id && datagram == expected_dgram
+            )
+        };
+        assert!(self.client.events().any(wt_datagram_event));
+    }
+
+    fn check_datagram_received_server(
+        &mut self,
+        expected_session: &WebTransportRequest,
+        expected_dgram: &[u8],
+    ) {
+        let wt_datagram_event = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::WebTransport(WebTransportServerEvent::Datagram {
+                    session,
+                    datagram
+                }) if session.stream_id() == expected_session.stream_id() && datagram == expected_dgram
+            )
+        };
+        assert!(self.server.events().any(wt_datagram_event));
+    }
+
+    fn check_no_datagram_received_client(&mut self) {
+        let wt_datagram_event = |e| {
+            matches!(
+                e,
+                Http3ClientEvent::WebTransport(WebTransportEvent::Datagram { .. })
+            )
+        };
+        assert!(!self.client.events().any(wt_datagram_event));
+    }
+
+    fn check_no_datagram_received_server(&mut self) {
+        let wt_datagram_event = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::WebTransport(WebTransportServerEvent::Datagram { .. })
+            )
+        };
+        assert!(!self.server.events().any(wt_datagram_event));
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/negotiation.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/negotiation.rs
new file mode 100644
index 0000000000..27f669861d
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/negotiation.rs
@@ -0,0 +1,280 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::time::Duration;
+
+use neqo_common::{event::Provider, Encoder};
+use neqo_crypto::AuthenticationStatus;
+use neqo_transport::{Connection, ConnectionError, StreamType};
+use test_fixture::{default_server_h3, now};
+
+use super::{connect, default_http3_client, default_http3_server, exchange_packets};
+use crate::{
+    settings::{HSetting, HSettingType, HSettings},
+    Error, HFrame, Http3Client, Http3ClientEvent, Http3Parameters, Http3Server, Http3State,
+    WebTransportEvent,
+};
+
+fn check_wt_event(client: &mut Http3Client, wt_enable_client: bool, wt_enable_server: bool) {
+    let wt_event = client.events().find_map(|e| {
+        if let Http3ClientEvent::WebTransport(WebTransportEvent::Negotiated(neg)) = e {
+            Some(neg)
+        } else {
+            None
+        }
+    });
+
+    assert_eq!(wt_event.is_some(), wt_enable_client);
+    if let Some(wt) = wt_event {
+        assert_eq!(wt, wt_enable_client && wt_enable_server);
+    }
+}
+
+fn connect_wt(wt_enabled_client: bool, wt_enabled_server: bool) -> (Http3Client, Http3Server) {
+    connect(
+        Http3Parameters::default().webtransport(wt_enabled_client),
+        Http3Parameters::default().webtransport(wt_enabled_server),
+    )
+}
+
+#[test]
+fn negotiate_wt() {
+    let (mut client, _server) = connect_wt(true, true);
+    assert!(client.webtransport_enabled());
+    check_wt_event(&mut client, true, true);
+
+    let (mut client, _server) = connect_wt(true, false);
+    assert!(!client.webtransport_enabled());
+    check_wt_event(&mut client, true, false);
+
+    let (mut client, _server) = connect_wt(false, true);
+    assert!(!client.webtransport_enabled());
+    check_wt_event(&mut client, false, true);
+
+    let (mut client, _server) = connect_wt(false, false);
+    assert!(!client.webtransport_enabled());
+    check_wt_event(&mut client, false, false);
+}
+
+#[derive(PartialEq, Eq)]
+enum ClientState {
+    ClientEnabled,
+    ClientDisabled,
+}
+
+#[derive(PartialEq, Eq)]
+enum ServerState {
+    ServerEnabled,
+    ServerDisabled,
+}
+
+fn zero_rtt(
+    client_state: &ClientState,
+    server_state: &ServerState,
+    client_resumed_state: &ClientState,
+    server_resumed_state: &ServerState,
+) {
+    let client_org = ClientState::ClientEnabled.eq(client_state);
+    let server_org = ServerState::ServerEnabled.eq(server_state);
+    let client_resumed = ClientState::ClientEnabled.eq(client_resumed_state);
+    let server_resumed = ServerState::ServerEnabled.eq(server_resumed_state);
+
+    let (mut client, mut server) = connect_wt(client_org, server_org);
+    assert_eq!(client.webtransport_enabled(), client_org && server_org);
+
+    // exchange token
+    let out = server.process(None, now());
+    // We do not have a token so we need to wait for a resumption token timer to trigger.
+    std::mem::drop(client.process(out.as_dgram_ref(), now() + Duration::from_millis(250)));
+    assert_eq!(client.state(), Http3State::Connected);
+    let token = client
+        .events()
+        .find_map(|e| {
+            if let Http3ClientEvent::ResumptionToken(token) = e {
+                Some(token)
+            } else {
+                None
+            }
+        })
+        .unwrap();
+
+    let mut client = default_http3_client(Http3Parameters::default().webtransport(client_resumed));
+    let mut server = default_http3_server(Http3Parameters::default().webtransport(server_resumed));
+    client
+        .enable_resumption(now(), &token)
+        .expect("Set resumption token.");
+    assert_eq!(client.state(), Http3State::ZeroRtt);
+
+    exchange_packets(&mut client, &mut server);
+
+    assert_eq!(&client.state(), &Http3State::Connected);
+    assert_eq!(
+        client.webtransport_enabled(),
+        client_resumed && server_resumed
+    );
+
+    let mut early_data_accepted = true;
+    // The only case we should not do 0-RTT is when webtransport was enabled
+    // originally and is disabled afterwards.
+    if server_org && !server_resumed {
+        early_data_accepted = false;
+    }
+    assert_eq!(
+        client.tls_info().unwrap().early_data_accepted(),
+        early_data_accepted
+    );
+
+    check_wt_event(&mut client, client_resumed, server_resumed);
+}
+
+#[test]
+fn zero_rtt_wt_settings() {
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+    );
+
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+    );
+
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+    );
+
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientDisabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerDisabled,
+    );
+    zero_rtt(
+        &ClientState::ClientDisabled,
+        &ServerState::ServerEnabled,
+        &ClientState::ClientEnabled,
+        &ServerState::ServerEnabled,
+    );
+}
+
+fn exchange_packets2(client: &mut Http3Client, server: &mut Connection) {
+    let mut out = None;
+    loop {
+        out = client.process(out.as_ref(), now()).dgram();
+        out = server.process(out.as_ref(), now()).dgram();
+        if out.is_none() {
+            break;
+        }
+    }
+}
+
+#[test]
+fn wrong_setting_value() {
+    const CONTROL_STREAM_TYPE: &[u8] = &[0x0];
+    let mut client = default_http3_client(Http3Parameters::default());
+    let mut server = default_server_h3();
+
+    exchange_packets2(&mut client, &mut server);
+    client.authenticated(AuthenticationStatus::Ok, now());
+    exchange_packets2(&mut client, &mut server);
+
+    let control = server.stream_create(StreamType::UniDi).unwrap();
+    server.stream_send(control, CONTROL_STREAM_TYPE).unwrap();
+    // Encode a settings frame and send it.
+    let mut enc = Encoder::default();
+    let settings = HFrame::Settings {
+        settings: HSettings::new(&[HSetting::new(HSettingType::EnableWebTransport, 2)]),
+    };
+    settings.encode(&mut enc);
+    assert_eq!(
+        server.stream_send(control, enc.as_ref()).unwrap(),
+        enc.as_ref().len()
+    );
+
+    exchange_packets2(&mut client, &mut server);
+    match client.state() {
+        Http3State::Closing(err) | Http3State::Closed(err) => {
+            assert_eq!(
+                err,
+                ConnectionError::Application(Error::HttpSettings.code())
+            );
+        }
+        _ => panic!("Wrong state {:?}", client.state()),
+    };
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/sessions.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/sessions.rs
new file mode 100644
index 0000000000..5f929d0e4b
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/sessions.rs
@@ -0,0 +1,456 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem;
+
+use neqo_common::{event::Provider, Encoder};
+use neqo_transport::StreamType;
+use test_fixture::now;
+
+use crate::{
+    features::extended_connect::{
+        tests::webtransport::{
+            default_http3_client, default_http3_server, wt_default_parameters, WtTest,
+        },
+        SessionCloseReason,
+    },
+    frames::WebTransportFrame,
+    Error, Header, Http3ClientEvent, Http3OrWebTransportStream, Http3Server, Http3ServerEvent,
+    Http3State, Priority, WebTransportEvent, WebTransportServerEvent,
+    WebTransportSessionAcceptAction,
+};
+
+#[test]
+fn wt_session() {
+    let mut wt = WtTest::new();
+    mem::drop(wt.create_wt_session());
+}
+
+#[test]
+fn wt_session_reject() {
+    let mut wt = WtTest::new();
+    let headers = vec![Header::new(":status", "404")];
+    let accept_res = WebTransportSessionAcceptAction::Reject(headers.clone());
+    let (wt_session_id, _wt_session) = wt.negotiate_wt_session(&accept_res);
+
+    wt.check_session_closed_event_client(
+        wt_session_id,
+        &SessionCloseReason::Status(404),
+        &Some(headers),
+    );
+}
+
+#[test]
+fn wt_session_close_client() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt.cancel_session_client(wt_session.stream_id());
+    wt.check_session_closed_event_server(
+        &mut wt_session,
+        &SessionCloseReason::Error(Error::HttpNoError.code()),
+    );
+}
+
+#[test]
+fn wt_session_close_server() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt.cancel_session_server(&mut wt_session);
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Error(Error::HttpNoError.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_session_close_server_close_send() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt_session.stream_close_send().unwrap();
+    wt.exchange_packets();
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Clean {
+            error: 0,
+            message: String::new(),
+        },
+        &None,
+    );
+}
+
+#[test]
+fn wt_session_close_server_stop_sending() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt_session
+        .stream_stop_sending(Error::HttpNoError.code())
+        .unwrap();
+    wt.exchange_packets();
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Error(Error::HttpNoError.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_session_close_server_reset() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt_session
+        .stream_reset_send(Error::HttpNoError.code())
+        .unwrap();
+    wt.exchange_packets();
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Error(Error::HttpNoError.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_session_response_with_1xx() {
+    let mut wt = WtTest::new();
+
+    let wt_session_id = wt
+        .client
+        .webtransport_create_session(now(), &("https", "something.com", "/"), &[])
+        .unwrap();
+    wt.exchange_packets();
+
+    let mut wt_server_session = None;
+    while let Some(event) = wt.server.next_event() {
+        if let Http3ServerEvent::WebTransport(WebTransportServerEvent::NewSession {
+            session,
+            headers,
+        }) = event
+        {
+            assert!(
+                headers
+                    .iter()
+                    .any(|h| h.name() == ":method" && h.value() == "CONNECT")
+                    && headers
+                        .iter()
+                        .any(|h| h.name() == ":protocol" && h.value() == "webtransport")
+            );
+            wt_server_session = Some(session);
+        }
+    }
+
+    let mut wt_server_session = wt_server_session.unwrap();
+
+    // Send interim response.
+    wt_server_session
+        .send_headers(&[Header::new(":status", "111")])
+        .unwrap();
+    wt_server_session
+        .response(&WebTransportSessionAcceptAction::Accept)
+        .unwrap();
+
+    wt.exchange_packets();
+
+    let wt_session_negotiated_event = |e| {
+        matches!(
+            e,
+            Http3ClientEvent::WebTransport(WebTransportEvent::Session{
+                stream_id,
+                status,
+                headers,
+            }) if (
+                stream_id == wt_session_id &&
+                status == 200 &&
+                headers.contains(&Header::new(":status", "200"))
+            )
+        )
+    };
+    assert!(wt.client.events().any(wt_session_negotiated_event));
+
+    assert_eq!(wt_session_id, wt_server_session.stream_id());
+}
+
+#[test]
+fn wt_session_response_with_redirect() {
+    let headers = [Header::new(":status", "302"), Header::new("location", "/")].to_vec();
+    let mut wt = WtTest::new();
+
+    let accept_res = WebTransportSessionAcceptAction::Reject(headers.clone());
+
+    let (wt_session_id, _wt_session) = wt.negotiate_wt_session(&accept_res);
+
+    wt.check_session_closed_event_client(
+        wt_session_id,
+        &SessionCloseReason::Status(302),
+        &Some(headers),
+    );
+}
+
+#[test]
+fn wt_session_respone_200_with_fin() {
+    let mut wt = WtTest::new();
+
+    let wt_session_id = wt
+        .client
+        .webtransport_create_session(now(), &("https", "something.com", "/"), &[])
+        .unwrap();
+    wt.exchange_packets();
+    let mut wt_server_session = None;
+    while let Some(event) = wt.server.next_event() {
+        if let Http3ServerEvent::WebTransport(WebTransportServerEvent::NewSession {
+            session,
+            headers,
+        }) = event
+        {
+            assert!(
+                headers
+                    .iter()
+                    .any(|h| h.name() == ":method" && h.value() == "CONNECT")
+                    && headers
+                        .iter()
+                        .any(|h| h.name() == ":protocol" && h.value() == "webtransport")
+            );
+            wt_server_session = Some(session);
+        }
+    }
+
+    let mut wt_server_session = wt_server_session.unwrap();
+    wt_server_session
+        .response(&WebTransportSessionAcceptAction::Accept)
+        .unwrap();
+    wt_server_session.stream_close_send().unwrap();
+
+    wt.exchange_packets();
+
+    let wt_session_close_event = |e| {
+        matches!(
+            e,
+            Http3ClientEvent::WebTransport(WebTransportEvent::SessionClosed{
+                stream_id,
+                reason,
+                headers,
+                ..
+            }) if (
+                stream_id == wt_session_id &&
+                reason == SessionCloseReason::Clean{ error: 0, message: String::new()} &&
+                headers.is_none()
+            )
+        )
+    };
+    assert!(wt.client.events().any(wt_session_close_event));
+
+    assert_eq!(wt_session_id, wt_server_session.stream_id());
+}
+
+#[test]
+fn wt_session_close_frame_client() {
+    const ERROR_NUM: u32 = 23;
+    const ERROR_MESSAGE: &str = "Something went wrong";
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    wt.session_close_frame_client(wt_session.stream_id(), ERROR_NUM, ERROR_MESSAGE);
+    wt.exchange_packets();
+
+    wt.check_session_closed_event_server(
+        &mut wt_session,
+        &SessionCloseReason::Clean {
+            error: ERROR_NUM,
+            message: ERROR_MESSAGE.to_string(),
+        },
+    );
+}
+
+#[test]
+fn wt_session_close_frame_server() {
+    const ERROR_NUM: u32 = 23;
+    const ERROR_MESSAGE: &str = "Something went wrong";
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    WtTest::session_close_frame_server(&mut wt_session, ERROR_NUM, ERROR_MESSAGE);
+    wt.exchange_packets();
+
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Clean {
+            error: ERROR_NUM,
+            message: ERROR_MESSAGE.to_string(),
+        },
+        &None,
+    );
+}
+
+#[test]
+fn wt_unknown_session_frame_client() {
+    const UNKNOWN_FRAME_LEN: usize = 832;
+    const BUF: &[u8] = &[0; 10];
+    const ERROR_NUM: u32 = 23;
+    const ERROR_MESSAGE: &str = "Something went wrong";
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    // Send an unknown frame.
+    let mut enc = Encoder::with_capacity(UNKNOWN_FRAME_LEN + 4);
+    enc.encode_varint(1028_u64); // Arbitrary type.
+    enc.encode_varint(UNKNOWN_FRAME_LEN as u64);
+    let mut buf: Vec<_> = enc.into();
+    buf.resize(UNKNOWN_FRAME_LEN + buf.len(), 0);
+    wt.client.send_data(wt_session.stream_id(), &buf).unwrap();
+    wt.exchange_packets();
+
+    // The session is still active
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.receive_data_client(unidi_server.stream_id(), true, BUF, false);
+
+    // Now close the session.
+    wt.session_close_frame_client(wt_session.stream_id(), ERROR_NUM, ERROR_MESSAGE);
+    wt.exchange_packets();
+
+    wt.check_events_after_closing_session_client(
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &None,
+    );
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Clean {
+                error: ERROR_NUM,
+                message: ERROR_MESSAGE.to_string(),
+            },
+        )),
+    );
+}
+
+#[test]
+fn wt_close_session_frame_broken_client() {
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    // Send a incorrect CloseSession frame.
+    let mut enc = Encoder::default();
+    WebTransportFrame::CloseSession {
+        error: 5,
+        message: "Hello".to_string(),
+    }
+    .encode(&mut enc);
+    let mut buf: Vec<_> = enc.into();
+    // Corrupt the string.
+    buf[9] = 0xff;
+    wt.client.send_data(wt_session.stream_id(), &buf).unwrap();
+    wt.exchange_packets();
+
+    // check that the webtransport session is closed.
+    wt.check_session_closed_event_client(
+        wt_session.stream_id(),
+        &SessionCloseReason::Error(Error::HttpGeneralProtocolStream.code()),
+        &None,
+    );
+    wt.check_session_closed_event_server(
+        &mut wt_session,
+        &SessionCloseReason::Error(Error::HttpGeneralProtocolStream.code()),
+    );
+
+    // The Http3 session is still working.
+    assert_eq!(wt.client.state(), Http3State::Connected);
+    assert_eq!(wt_session.state(), Http3State::Connected);
+}
+
+fn receive_request(server: &mut Http3Server) -> Option<Http3OrWebTransportStream> {
+    while let Some(event) = server.next_event() {
+        if let Http3ServerEvent::Headers { stream, .. } = event {
+            return Some(stream);
+        }
+    }
+    None
+}
+
+#[test]
+// Ignoring this test as it is panicking at wt.create_wt_stream_client
+// Issue # 1386 is created to track this
+#[ignore]
+fn wt_close_session_cannot_be_sent_at_once() {
+    const BUF: &[u8] = &[0; 443];
+    const ERROR_NUM: u32 = 23;
+    const ERROR_MESSAGE: &str = "Something went wrong";
+
+    let client = default_http3_client(wt_default_parameters());
+    let server = default_http3_server(wt_default_parameters());
+    let mut wt = WtTest::new_with(client, server);
+
+    let mut wt_session = wt.create_wt_session();
+
+    // Fill the flow control window using an unrelated http stream.
+    let req_id = wt
+        .client
+        .fetch(
+            now(),
+            "GET",
+            &("https", "something.com", "/"),
+            &[],
+            Priority::default(),
+        )
+        .unwrap();
+    assert_eq!(req_id, 4);
+    wt.exchange_packets();
+    let mut req = receive_request(&mut wt.server).unwrap();
+    req.send_headers(&[
+        Header::new(":status", "200"),
+        Header::new("content-length", BUF.len().to_string()),
+    ])
+    .unwrap();
+    req.send_data(BUF).unwrap();
+
+    // Now close the session.
+    WtTest::session_close_frame_server(&mut wt_session, ERROR_NUM, ERROR_MESSAGE);
+    // server cannot create new streams.
+    assert_eq!(
+        wt_session.create_stream(StreamType::UniDi),
+        Err(Error::InvalidStreamId)
+    );
+
+    let out = wt.server.process(None, now());
+    let out = wt.client.process(out.as_dgram_ref(), now());
+
+    // Client has not received the full CloseSession frame and it can create more streams.
+    let unidi_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+
+    let out = wt.server.process(out.as_dgram_ref(), now());
+    let out = wt.client.process(out.as_dgram_ref(), now());
+    let out = wt.server.process(out.as_dgram_ref(), now());
+    let out = wt.client.process(out.as_dgram_ref(), now());
+    let out = wt.server.process(out.as_dgram_ref(), now());
+    let _out = wt.client.process(out.as_dgram_ref(), now());
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[unidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Clean {
+                error: ERROR_NUM,
+                message: ERROR_MESSAGE.to_string(),
+            },
+        )),
+    );
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/streams.rs b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/streams.rs
new file mode 100644
index 0000000000..b898dbb31e
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/tests/webtransport/streams.rs
@@ -0,0 +1,1131 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem;
+
+use neqo_transport::StreamType;
+
+use crate::{
+    features::extended_connect::{tests::webtransport::WtTest, SessionCloseReason},
+    Error,
+};
+
+#[test]
+fn wt_client_stream_uni() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    let send_stats = wt.send_stream_stats(wt_stream).unwrap();
+    assert_eq!(send_stats.bytes_written(), 0);
+    assert_eq!(send_stats.bytes_sent(), 0);
+    assert_eq!(send_stats.bytes_acked(), 0);
+
+    wt.send_data_client(wt_stream, BUF_CLIENT);
+    wt.receive_data_server(wt_stream, true, BUF_CLIENT, false);
+    let send_stats = wt.send_stream_stats(wt_stream).unwrap();
+    assert_eq!(send_stats.bytes_written(), BUF_CLIENT.len() as u64);
+    assert_eq!(send_stats.bytes_sent(), BUF_CLIENT.len() as u64);
+    assert_eq!(send_stats.bytes_acked(), BUF_CLIENT.len() as u64);
+
+    // Send data again to test if the stats has the expected values.
+    wt.send_data_client(wt_stream, BUF_CLIENT);
+    wt.receive_data_server(wt_stream, false, BUF_CLIENT, false);
+    let send_stats = wt.send_stream_stats(wt_stream).unwrap();
+    assert_eq!(send_stats.bytes_written(), (BUF_CLIENT.len() * 2) as u64);
+    assert_eq!(send_stats.bytes_sent(), (BUF_CLIENT.len() * 2) as u64);
+    assert_eq!(send_stats.bytes_acked(), (BUF_CLIENT.len() * 2) as u64);
+
+    let recv_stats = wt.recv_stream_stats(wt_stream);
+    assert_eq!(recv_stats.unwrap_err(), Error::InvalidStreamId);
+}
+
+#[test]
+fn wt_client_stream_bidi() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_client_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(wt_client_stream, BUF_CLIENT);
+    let mut wt_server_stream = wt.receive_data_server(wt_client_stream, true, BUF_CLIENT, false);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_client_stream, false, BUF_SERVER, false);
+    let send_stats = wt.send_stream_stats(wt_client_stream).unwrap();
+    assert_eq!(send_stats.bytes_written(), BUF_CLIENT.len() as u64);
+    assert_eq!(send_stats.bytes_sent(), BUF_CLIENT.len() as u64);
+    assert_eq!(send_stats.bytes_acked(), BUF_CLIENT.len() as u64);
+
+    let recv_stats = wt.recv_stream_stats(wt_client_stream).unwrap();
+    assert_eq!(recv_stats.bytes_received(), BUF_SERVER.len() as u64);
+    assert_eq!(recv_stats.bytes_read(), BUF_SERVER.len() as u64);
+}
+
+#[test]
+fn wt_server_stream_uni() {
+    const BUF_SERVER: &[u8] = &[2; 30];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+    let send_stats = wt.send_stream_stats(wt_server_stream.stream_id());
+    assert_eq!(send_stats.unwrap_err(), Error::InvalidStreamId);
+
+    let recv_stats = wt.recv_stream_stats(wt_server_stream.stream_id()).unwrap();
+    assert_eq!(recv_stats.bytes_received(), BUF_SERVER.len() as u64);
+    assert_eq!(recv_stats.bytes_read(), BUF_SERVER.len() as u64);
+}
+
+#[test]
+fn wt_server_stream_bidi() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+    wt.send_data_client(wt_server_stream.stream_id(), BUF_CLIENT);
+    mem::drop(wt.receive_data_server(wt_server_stream.stream_id(), false, BUF_CLIENT, false));
+    let stats = wt.send_stream_stats(wt_server_stream.stream_id()).unwrap();
+    assert_eq!(stats.bytes_written(), BUF_CLIENT.len() as u64);
+    assert_eq!(stats.bytes_sent(), BUF_CLIENT.len() as u64);
+    assert_eq!(stats.bytes_acked(), BUF_CLIENT.len() as u64);
+
+    let recv_stats = wt.recv_stream_stats(wt_server_stream.stream_id()).unwrap();
+    assert_eq!(recv_stats.bytes_received(), BUF_SERVER.len() as u64);
+    assert_eq!(recv_stats.bytes_read(), BUF_SERVER.len() as u64);
+}
+
+#[test]
+fn wt_client_stream_uni_close() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(wt_stream, BUF_CLIENT);
+    wt.close_stream_sending_client(wt_stream);
+    wt.receive_data_server(wt_stream, true, BUF_CLIENT, true);
+}
+
+#[test]
+fn wt_client_stream_bidi_close() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_client_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+
+    wt.send_data_client(wt_client_stream, BUF_CLIENT);
+    wt.close_stream_sending_client(wt_client_stream);
+
+    let mut wt_server_stream = wt.receive_data_server(wt_client_stream, true, BUF_CLIENT, true);
+
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.close_stream_sending_server(&mut wt_server_stream);
+    wt.receive_data_client(wt_client_stream, false, BUF_SERVER, true);
+}
+
+#[test]
+fn wt_server_stream_uni_closed() {
+    const BUF_SERVER: &[u8] = &[2; 30];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.close_stream_sending_server(&mut wt_server_stream);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, true);
+}
+
+#[test]
+fn wt_server_stream_bidi_close() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.close_stream_sending_server(&mut wt_server_stream);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, true);
+    wt.send_data_client(wt_server_stream.stream_id(), BUF_CLIENT);
+    wt.close_stream_sending_client(wt_server_stream.stream_id());
+    mem::drop(wt.receive_data_server(wt_server_stream.stream_id(), false, BUF_CLIENT, true));
+}
+
+#[test]
+fn wt_client_stream_uni_reset() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(wt_stream, BUF_CLIENT);
+    mem::drop(wt.receive_data_server(wt_stream, true, BUF_CLIENT, false));
+    wt.reset_stream_client(wt_stream);
+    wt.receive_reset_server(wt_stream, Error::HttpNoError.code());
+}
+
+#[test]
+fn wt_server_stream_uni_reset() {
+    const BUF_SERVER: &[u8] = &[2; 30];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+    wt.reset_stream_server(&mut wt_server_stream);
+    wt.receive_reset_client(wt_server_stream.stream_id());
+}
+
+#[test]
+fn wt_client_stream_bidi_reset() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_client_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+
+    wt.send_data_client(wt_client_stream, BUF_CLIENT);
+    let mut wt_server_stream = wt.receive_data_server(wt_client_stream, true, BUF_CLIENT, false);
+
+    wt.reset_stream_client(wt_client_stream);
+    wt.receive_reset_server(wt_server_stream.stream_id(), Error::HttpNoError.code());
+
+    wt.reset_stream_server(&mut wt_server_stream);
+    wt.receive_reset_client(wt_client_stream);
+}
+
+#[test]
+fn wt_server_stream_bidi_reset() {
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+
+    wt.reset_stream_client(wt_server_stream.stream_id());
+    wt.receive_reset_server(wt_server_stream.stream_id(), Error::HttpNoError.code());
+
+    wt.reset_stream_server(&mut wt_server_stream);
+    wt.receive_reset_client(wt_server_stream.stream_id());
+}
+
+#[test]
+fn wt_client_stream_uni_stop_sending() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+    let wt_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(wt_stream, BUF_CLIENT);
+    let mut wt_server_stream = wt.receive_data_server(wt_stream, true, BUF_CLIENT, false);
+    wt.stream_stop_sending_server(&mut wt_server_stream);
+    wt.receive_stop_sending_client(wt_stream);
+}
+
+#[test]
+fn wt_server_stream_uni_stop_sending() {
+    const BUF_SERVER: &[u8] = &[2; 30];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+    wt.stream_stop_sending_client(wt_server_stream.stream_id());
+    wt.receive_stop_sending_server(wt_server_stream.stream_id(), Error::HttpNoError.code());
+}
+
+#[test]
+fn wt_client_stream_bidi_stop_sending() {
+    const BUF_CLIENT: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let wt_client_stream = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+
+    wt.send_data_client(wt_client_stream, BUF_CLIENT);
+
+    let mut wt_server_stream = wt.receive_data_server(wt_client_stream, true, BUF_CLIENT, false);
+
+    wt.stream_stop_sending_client(wt_client_stream);
+
+    wt.receive_stop_sending_server(wt_server_stream.stream_id(), Error::HttpNoError.code());
+    wt.stream_stop_sending_server(&mut wt_server_stream);
+    wt.receive_stop_sending_client(wt_server_stream.stream_id());
+}
+
+#[test]
+fn wt_server_stream_bidi_stop_sending() {
+    const BUF_SERVER: &[u8] = &[1; 20];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+    let mut wt_server_stream = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+
+    wt.send_data_server(&mut wt_server_stream, BUF_SERVER);
+    wt.receive_data_client(wt_server_stream.stream_id(), true, BUF_SERVER, false);
+    wt.stream_stop_sending_client(wt_server_stream.stream_id());
+    wt.receive_stop_sending_server(wt_server_stream.stream_id(), Error::HttpNoError.code());
+    wt.stream_stop_sending_server(&mut wt_server_stream);
+    wt.receive_stop_sending_client(wt_server_stream.stream_id());
+}
+
+// For the following tests the client cancels a session. The streams are in different states:
+//  1) Both sides of a bidirectional client stream are opened.
+//  2) A client unidirectional stream is opened.
+//  3) A client unidirectional stream has been closed and both sides consumed the closing info.
+//  4) A client unidirectional stream has been closed, but only the server has consumed the closing
+//     info.
+//  5) A client unidirectional stream has been closed, but only the client has consum the closing
+//     info.
+//  6) Both sides of a bidirectional server stream are opened.
+//  7) A server unidirectional stream is opened.
+//  8) A server unidirectional stream has been closed and both sides consumed the closing info.
+//  9) A server unidirectional stream has been closed, but only the server has consumed the closing
+//     info.
+//  10) A server unidirectional stream has been closed, but only the client has consumed the closing
+//      info.
+//  11) Both sides of a bidirectional stream have been closed and consumed by both sides.
+//  12) Both sides of a bidirectional stream have been closed, but not consumed by both sides.
+//  13) Multiples open streams
+
+#[test]
+fn wt_client_session_close_1() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let bidi_from_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_from_client, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_from_client, true, BUF, false));
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_2() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let unidi_from_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+
+    wt.send_data_client(unidi_from_client, BUF);
+    std::mem::drop(wt.receive_data_server(unidi_from_client, true, BUF, false));
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[unidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[unidi_from_client],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_3() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let unidi_from_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+
+    wt.send_data_client(unidi_from_client, BUF);
+    std::mem::drop(wt.receive_data_server(unidi_from_client, true, BUF, false));
+    wt.close_stream_sending_client(unidi_from_client);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(&[], None, &[], None, false, &None);
+}
+
+#[test]
+fn wt_client_session_close_4() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let unidi_from_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+
+    wt.send_data_client(unidi_from_client, BUF);
+    let mut unidi_from_client_s = wt.receive_data_server(unidi_from_client, true, BUF, false);
+    wt.stream_stop_sending_server(&mut unidi_from_client_s);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[unidi_from_client],
+        Some(Error::HttpNoError.code()),
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_5() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let unidi_from_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+
+    wt.send_data_client(unidi_from_client, BUF);
+    mem::drop(wt.receive_data_server(unidi_from_client, true, BUF, false));
+    wt.reset_stream_client(unidi_from_client);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[unidi_from_client],
+        Some(Error::HttpNoError.code()),
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(&[], None, &[], None, false, &None);
+}
+
+#[test]
+fn wt_client_session_close_6() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_from_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_from_server, BUF);
+    wt.receive_data_client(bidi_from_server.stream_id(), true, BUF, false);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_7() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_from_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_from_server, BUF);
+    wt.receive_data_client(unidi_from_server.stream_id(), true, BUF, false);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[unidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[unidi_from_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_8() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.close_stream_sending_server(&mut unidi_server);
+    wt.receive_data_client(unidi_server.stream_id(), true, BUF, true);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(&[], None, &[], None, false, &None);
+}
+
+#[test]
+fn wt_client_session_close_9() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.stream_stop_sending_client(unidi_server.stream_id());
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[unidi_server.stream_id()],
+        Some(Error::HttpNoError.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(&[], None, &[], None, false, &None);
+}
+
+#[test]
+fn wt_client_session_close_10() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.close_stream_sending_server(&mut unidi_server);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_11() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_server, BUF);
+    wt.close_stream_sending_server(&mut bidi_server);
+    wt.receive_data_client(bidi_server.stream_id(), true, BUF, true);
+    wt.stream_stop_sending_server(&mut bidi_server);
+    wt.receive_stop_sending_client(bidi_server.stream_id());
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(&[], None, &[], None, false, &None);
+}
+
+#[test]
+fn wt_client_session_close_12() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_server, BUF);
+    wt.close_stream_sending_server(&mut bidi_server);
+    wt.stream_stop_sending_server(&mut bidi_server);
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[],
+        None,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_server.stream_id()],
+        Some(Error::HttpNoError.code()),
+        false,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_close_13() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let wt_session = wt.create_wt_session();
+
+    let bidi_client_1 = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_client_1, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_client_1, true, BUF, false));
+    let bidi_client_2 = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_client_2, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_client_2, true, BUF, false));
+
+    wt.cancel_session_client(wt_session.stream_id());
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &None,
+    );
+}
+
+// For the following tests the server cancels a session. The streams are in different states:
+//  1) Both sides of a bidirectional client stream are opened.
+//  2) A client unidirectional stream is opened.
+//  3) A client unidirectional stream has been closed and consumed by both sides.
+//  4) A client unidirectional stream has been closed, but not consumed by the client.
+//  5) Both sides of a bidirectional server stream are opened.
+//  6) A server unidirectional stream is opened.
+//  7) A server unidirectional stream has been closed and consumed by both sides.
+//  8) A server unidirectional stream has been closed, but not consumed by the client.
+//  9) Both sides of a bidirectional stream have been closed and consumed by both sides.
+//  10) Both sides of a bidirectional stream have been closed, but not consumed by the client.
+//  12) Multiples open streams
+
+#[test]
+fn wt_client_session_server_close_1() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let bidi_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_client, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_client, true, BUF, false));
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_server_close_2() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let unidi_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(unidi_client, BUF);
+    std::mem::drop(wt.receive_data_server(unidi_client, true, BUF, false));
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[unidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(
+        &[unidi_client],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_server_close_3() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let unidi_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(unidi_client, BUF);
+    let mut unidi_client_s = wt.receive_data_server(unidi_client, true, BUF, false);
+    wt.stream_stop_sending_server(&mut unidi_client_s);
+    wt.receive_stop_sending_client(unidi_client);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[],
+        None,
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_4() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let unidi_client = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::UniDi);
+    wt.send_data_client(unidi_client, BUF);
+    let mut unidi_client_s = wt.receive_data_server(unidi_client, true, BUF, false);
+    wt.stream_stop_sending_server(&mut unidi_client_s);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[unidi_client],
+        Some(Error::HttpNoError.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_5() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_server, BUF);
+    wt.receive_data_client(bidi_server.stream_id(), true, BUF, false);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_server_close_6() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.receive_data_client(unidi_server.stream_id(), true, BUF, false);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_client_session_server_close_7() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.close_stream_sending_server(&mut unidi_server);
+    wt.receive_data_client(unidi_server.stream_id(), true, BUF, true);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    // Already close stream will not have a reset event.
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[],
+        None,
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_8() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.close_stream_sending_server(&mut unidi_server);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    // The stream was only closed on the server side therefore it is cancelled on the client side.
+    wt.check_events_after_closing_session_client(
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_9() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_server, BUF);
+    wt.close_stream_sending_server(&mut bidi_server);
+    wt.receive_data_client(bidi_server.stream_id(), true, BUF, true);
+    wt.stream_stop_sending_server(&mut bidi_server);
+    wt.receive_stop_sending_client(bidi_server.stream_id());
+
+    wt.cancel_session_server(&mut wt_session);
+
+    // Already close stream will not have a reset event.
+    wt.check_events_after_closing_session_client(
+        &[],
+        None,
+        &[],
+        None,
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_10() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut bidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::BiDi);
+    wt.send_data_server(&mut bidi_server, BUF);
+    wt.close_stream_sending_server(&mut bidi_server);
+    wt.stream_stop_sending_server(&mut bidi_server);
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_server.stream_id()],
+        Some(Error::HttpNoError.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(&[], None, &[], None, &None);
+}
+
+#[test]
+fn wt_client_session_server_close_11() {
+    const BUF: &[u8] = &[0; 10];
+
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let bidi_client_1 = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_client_1, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_client_1, true, BUF, false));
+    let bidi_client_2 = wt.create_wt_stream_client(wt_session.stream_id(), StreamType::BiDi);
+    wt.send_data_client(bidi_client_2, BUF);
+    std::mem::drop(wt.receive_data_server(bidi_client_2, true, BUF, false));
+
+    wt.cancel_session_server(&mut wt_session);
+
+    wt.check_events_after_closing_session_client(
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        false,
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Error(Error::HttpNoError.code()),
+        )),
+    );
+
+    wt.check_events_after_closing_session_server(
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &[bidi_client_1, bidi_client_2],
+        Some(Error::HttpRequestCancelled.code()),
+        &None,
+    );
+}
+
+#[test]
+fn wt_session_close_frame_and_streams_client() {
+    const BUF: &[u8] = &[0; 10];
+    const ERROR_NUM: u32 = 23;
+    const ERROR_MESSAGE: &str = "Something went wrong";
+    let mut wt = WtTest::new();
+    let mut wt_session = wt.create_wt_session();
+
+    let mut unidi_server = WtTest::create_wt_stream_server(&mut wt_session, StreamType::UniDi);
+    wt.send_data_server(&mut unidi_server, BUF);
+    wt.exchange_packets();
+
+    wt.session_close_frame_client(wt_session.stream_id(), ERROR_NUM, ERROR_MESSAGE);
+    wt.check_events_after_closing_session_client(
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &[],
+        None,
+        false,
+        &None,
+    );
+    wt.exchange_packets();
+
+    wt.check_events_after_closing_session_server(
+        &[],
+        None,
+        &[unidi_server.stream_id()],
+        Some(Error::HttpRequestCancelled.code()),
+        &Some((
+            wt_session.stream_id(),
+            SessionCloseReason::Clean {
+                error: ERROR_NUM,
+                message: ERROR_MESSAGE.to_string(),
+            },
+        )),
+    );
+}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_session.rs b/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_session.rs
new file mode 100644
index 0000000000..adbdf07e11
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_session.rs
@@ -0,0 +1,555 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{any::Any, cell::RefCell, collections::BTreeSet, mem, rc::Rc};
+
+use neqo_common::{qtrace, Encoder, Header, MessageType, Role};
+use neqo_qpack::{QPackDecoder, QPackEncoder};
+use neqo_transport::{streams::SendOrder, Connection, DatagramTracking, StreamId};
+
+use super::{ExtendedConnectEvents, ExtendedConnectType, SessionCloseReason};
+use crate::{
+    frames::{FrameReader, StreamReaderRecvStreamWrapper, WebTransportFrame},
+    recv_message::{RecvMessage, RecvMessageInfo},
+    send_message::SendMessage,
+    CloseType, Error, HFrame, Http3StreamInfo, Http3StreamType, HttpRecvStream,
+    HttpRecvStreamEvents, Priority, PriorityHandler, ReceiveOutput, RecvStream, RecvStreamEvents,
+    Res, SendStream, SendStreamEvents, Stream,
+};
+
+#[derive(Debug, PartialEq)]
+enum SessionState {
+    Negotiating,
+    Active,
+    FinPending,
+    Done,
+}
+
+impl SessionState {
+    pub fn closing_state(&self) -> bool {
+        matches!(self, Self::FinPending | Self::Done)
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct WebTransportSession {
+    control_stream_recv: Box<dyn RecvStream>,
+    control_stream_send: Box<dyn SendStream>,
+    stream_event_listener: Rc<RefCell<WebTransportSessionListener>>,
+    session_id: StreamId,
+    state: SessionState,
+    frame_reader: FrameReader,
+    events: Box<dyn ExtendedConnectEvents>,
+    send_streams: BTreeSet<StreamId>,
+    recv_streams: BTreeSet<StreamId>,
+    role: Role,
+}
+
+impl ::std::fmt::Display for WebTransportSession {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "WebTransportSession session={}", self.session_id,)
+    }
+}
+
+impl WebTransportSession {
+    #[must_use]
+    pub fn new(
+        session_id: StreamId,
+        events: Box<dyn ExtendedConnectEvents>,
+        role: Role,
+        qpack_encoder: Rc<RefCell<QPackEncoder>>,
+        qpack_decoder: Rc<RefCell<QPackDecoder>>,
+    ) -> Self {
+        let stream_event_listener = Rc::new(RefCell::new(WebTransportSessionListener::default()));
+        Self {
+            control_stream_recv: Box::new(RecvMessage::new(
+                &RecvMessageInfo {
+                    message_type: MessageType::Response,
+                    stream_type: Http3StreamType::ExtendedConnect,
+                    stream_id: session_id,
+                    header_frame_type_read: false,
+                },
+                qpack_decoder,
+                Box::new(stream_event_listener.clone()),
+                None,
+                PriorityHandler::new(false, Priority::default()),
+            )),
+            control_stream_send: Box::new(SendMessage::new(
+                MessageType::Request,
+                Http3StreamType::ExtendedConnect,
+                session_id,
+                qpack_encoder,
+                Box::new(stream_event_listener.clone()),
+            )),
+            stream_event_listener,
+            session_id,
+            state: SessionState::Negotiating,
+            frame_reader: FrameReader::new(),
+            events,
+            send_streams: BTreeSet::new(),
+            recv_streams: BTreeSet::new(),
+            role,
+        }
+    }
+
+    /// # Panics
+    ///
+    /// This function is only called with `RecvStream` and `SendStream` that also implement
+    /// the http specific functions and `http_stream()` will never return `None`.
+    #[must_use]
+    pub fn new_with_http_streams(
+        session_id: StreamId,
+        events: Box<dyn ExtendedConnectEvents>,
+        role: Role,
+        mut control_stream_recv: Box<dyn RecvStream>,
+        mut control_stream_send: Box<dyn SendStream>,
+    ) -> Self {
+        let stream_event_listener = Rc::new(RefCell::new(WebTransportSessionListener::default()));
+        control_stream_recv
+            .http_stream()
+            .unwrap()
+            .set_new_listener(Box::new(stream_event_listener.clone()));
+        control_stream_send
+            .http_stream()
+            .unwrap()
+            .set_new_listener(Box::new(stream_event_listener.clone()));
+        Self {
+            control_stream_recv,
+            control_stream_send,
+            stream_event_listener,
+            session_id,
+            state: SessionState::Active,
+            frame_reader: FrameReader::new(),
+            events,
+            send_streams: BTreeSet::new(),
+            recv_streams: BTreeSet::new(),
+            role,
+        }
+    }
+
+    /// # Errors
+    ///
+    /// The function can only fail if supplied headers are not valid http headers.
+    ///
+    /// # Panics
+    ///
+    /// `control_stream_send` implements the  http specific functions and `http_stream()`
+    /// will never return `None`.
+    pub fn send_request(&mut self, headers: &[Header], conn: &mut Connection) -> Res<()> {
+        self.control_stream_send
+            .http_stream()
+            .unwrap()
+            .send_headers(headers, conn)
+    }
+
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        qtrace!([self], "receive control data");
+        let (out, _) = self.control_stream_recv.receive(conn)?;
+        debug_assert!(out == ReceiveOutput::NoOutput);
+        self.maybe_check_headers();
+        self.read_control_stream(conn)?;
+        Ok((ReceiveOutput::NoOutput, self.state == SessionState::Done))
+    }
+
+    fn header_unblocked(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        let (out, _) = self
+            .control_stream_recv
+            .http_stream()
+            .unwrap()
+            .header_unblocked(conn)?;
+        debug_assert!(out == ReceiveOutput::NoOutput);
+        self.maybe_check_headers();
+        self.read_control_stream(conn)?;
+        Ok((ReceiveOutput::NoOutput, self.state == SessionState::Done))
+    }
+
+    fn maybe_update_priority(&mut self, priority: Priority) -> bool {
+        self.control_stream_recv
+            .http_stream()
+            .unwrap()
+            .maybe_update_priority(priority)
+    }
+
+    fn priority_update_frame(&mut self) -> Option<HFrame> {
+        self.control_stream_recv
+            .http_stream()
+            .unwrap()
+            .priority_update_frame()
+    }
+
+    fn priority_update_sent(&mut self) {
+        self.control_stream_recv
+            .http_stream()
+            .unwrap()
+            .priority_update_sent();
+    }
+
+    fn send(&mut self, conn: &mut Connection) -> Res<()> {
+        self.control_stream_send.send(conn)?;
+        if self.control_stream_send.done() {
+            self.state = SessionState::Done;
+        }
+        Ok(())
+    }
+
+    fn has_data_to_send(&self) -> bool {
+        self.control_stream_send.has_data_to_send()
+    }
+
+    fn done(&self) -> bool {
+        self.state == SessionState::Done
+    }
+
+    fn close(&mut self, close_type: CloseType) {
+        if self.state.closing_state() {
+            return;
+        }
+        qtrace!("ExtendedConnect close the session");
+        self.state = SessionState::Done;
+        if !close_type.locally_initiated() {
+            self.events.session_end(
+                ExtendedConnectType::WebTransport,
+                self.session_id,
+                SessionCloseReason::from(close_type),
+                None,
+            );
+        }
+    }
+
+    /// # Panics
+    ///
+    /// This cannot panic because headers are checked before this function called.
+    pub fn maybe_check_headers(&mut self) {
+        if SessionState::Negotiating != self.state {
+            return;
+        }
+
+        if let Some((headers, interim, fin)) = self.stream_event_listener.borrow_mut().get_headers()
+        {
+            qtrace!(
+                "ExtendedConnect response headers {:?}, fin={}",
+                headers,
+                fin
+            );
+
+            if interim {
+                if fin {
+                    self.events.session_end(
+                        ExtendedConnectType::WebTransport,
+                        self.session_id,
+                        SessionCloseReason::Clean {
+                            error: 0,
+                            message: String::new(),
+                        },
+                        Some(headers),
+                    );
+                    self.state = SessionState::Done;
+                }
+            } else {
+                let status = headers
+                    .iter()
+                    .find_map(|h| {
+                        if h.name() == ":status" {
+                            h.value().parse::<u16>().ok()
+                        } else {
+                            None
+                        }
+                    })
+                    .unwrap();
+
+                self.state = if (200..300).contains(&status) {
+                    if fin {
+                        self.events.session_end(
+                            ExtendedConnectType::WebTransport,
+                            self.session_id,
+                            SessionCloseReason::Clean {
+                                error: 0,
+                                message: String::new(),
+                            },
+                            Some(headers),
+                        );
+                        SessionState::Done
+                    } else {
+                        self.events.session_start(
+                            ExtendedConnectType::WebTransport,
+                            self.session_id,
+                            status,
+                            headers,
+                        );
+                        SessionState::Active
+                    }
+                } else {
+                    self.events.session_end(
+                        ExtendedConnectType::WebTransport,
+                        self.session_id,
+                        SessionCloseReason::Status(status),
+                        Some(headers),
+                    );
+                    SessionState::Done
+                };
+            }
+        }
+    }
+
+    pub fn add_stream(&mut self, stream_id: StreamId) {
+        if let SessionState::Active = self.state {
+            if stream_id.is_bidi() {
+                self.send_streams.insert(stream_id);
+                self.recv_streams.insert(stream_id);
+            } else if stream_id.is_self_initiated(self.role) {
+                self.send_streams.insert(stream_id);
+            } else {
+                self.recv_streams.insert(stream_id);
+            }
+
+            if !stream_id.is_self_initiated(self.role) {
+                self.events
+                    .extended_connect_new_stream(Http3StreamInfo::new(
+                        stream_id,
+                        ExtendedConnectType::WebTransport.get_stream_type(self.session_id),
+                    ));
+            }
+        }
+    }
+
+    pub fn remove_recv_stream(&mut self, stream_id: StreamId) {
+        self.recv_streams.remove(&stream_id);
+    }
+
+    pub fn remove_send_stream(&mut self, stream_id: StreamId) {
+        self.send_streams.remove(&stream_id);
+    }
+
+    #[must_use]
+    pub fn is_active(&self) -> bool {
+        matches!(self.state, SessionState::Active)
+    }
+
+    pub fn take_sub_streams(&mut self) -> (BTreeSet<StreamId>, BTreeSet<StreamId>) {
+        (
+            mem::take(&mut self.recv_streams),
+            mem::take(&mut self.send_streams),
+        )
+    }
+
+    /// # Errors
+    ///
+    /// It may return an error if the frame is not correctly decoded.
+    pub fn read_control_stream(&mut self, conn: &mut Connection) -> Res<()> {
+        let (f, fin) = self
+            .frame_reader
+            .receive::<WebTransportFrame>(&mut StreamReaderRecvStreamWrapper::new(
+                conn,
+                &mut self.control_stream_recv,
+            ))
+            .map_err(|_| Error::HttpGeneralProtocolStream)?;
+        qtrace!([self], "Received frame: {:?} fin={}", f, fin);
+        if let Some(WebTransportFrame::CloseSession { error, message }) = f {
+            self.events.session_end(
+                ExtendedConnectType::WebTransport,
+                self.session_id,
+                SessionCloseReason::Clean { error, message },
+                None,
+            );
+            self.state = if fin {
+                SessionState::Done
+            } else {
+                SessionState::FinPending
+            };
+        } else if fin {
+            self.events.session_end(
+                ExtendedConnectType::WebTransport,
+                self.session_id,
+                SessionCloseReason::Clean {
+                    error: 0,
+                    message: String::new(),
+                },
+                None,
+            );
+            self.state = SessionState::Done;
+        }
+        Ok(())
+    }
+
+    /// # Errors
+    ///
+    /// Return an error if the stream was closed on the transport layer, but that information is not
+    /// yet consumed on the http/3 layer.
+    pub fn close_session(&mut self, conn: &mut Connection, error: u32, message: &str) -> Res<()> {
+        self.state = SessionState::Done;
+        let close_frame = WebTransportFrame::CloseSession {
+            error,
+            message: message.to_string(),
+        };
+        let mut encoder = Encoder::default();
+        close_frame.encode(&mut encoder);
+        self.control_stream_send
+            .send_data_atomic(conn, encoder.as_ref())?;
+        self.control_stream_send.close(conn)?;
+        self.state = if self.control_stream_send.done() {
+            SessionState::Done
+        } else {
+            SessionState::FinPending
+        };
+        Ok(())
+    }
+
+    fn send_data(&mut self, conn: &mut Connection, buf: &[u8]) -> Res<usize> {
+        self.control_stream_send.send_data(conn, buf)
+    }
+
+    /// # Errors
+    ///
+    /// Returns an error if the datagram exceeds the remote datagram size limit.
+    pub fn send_datagram(
+        &self,
+        conn: &mut Connection,
+        buf: &[u8],
+        id: impl Into<DatagramTracking>,
+    ) -> Res<()> {
+        qtrace!([self], "send_datagram state={:?}", self.state);
+        if let SessionState::Active = self.state {
+            let mut dgram_data = Encoder::default();
+            dgram_data.encode_varint(self.session_id.as_u64() / 4);
+            dgram_data.encode(buf);
+            conn.send_datagram(dgram_data.as_ref(), id)?;
+        } else {
+            debug_assert!(false);
+            return Err(Error::Unavailable);
+        }
+        Ok(())
+    }
+
+    pub fn datagram(&mut self, datagram: Vec<u8>) {
+        if let SessionState::Active = self.state {
+            self.events.new_datagram(self.session_id, datagram);
+        }
+    }
+}
+
+impl Stream for Rc<RefCell<WebTransportSession>> {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::ExtendedConnect
+    }
+}
+
+impl RecvStream for Rc<RefCell<WebTransportSession>> {
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        self.borrow_mut().receive(conn)
+    }
+
+    fn reset(&mut self, close_type: CloseType) -> Res<()> {
+        self.borrow_mut().close(close_type);
+        Ok(())
+    }
+
+    fn http_stream(&mut self) -> Option<&mut dyn HttpRecvStream> {
+        Some(self)
+    }
+
+    fn webtransport(&self) -> Option<Rc<RefCell<WebTransportSession>>> {
+        Some(self.clone())
+    }
+}
+
+impl HttpRecvStream for Rc<RefCell<WebTransportSession>> {
+    fn header_unblocked(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        self.borrow_mut().header_unblocked(conn)
+    }
+
+    fn maybe_update_priority(&mut self, priority: Priority) -> bool {
+        self.borrow_mut().maybe_update_priority(priority)
+    }
+
+    fn priority_update_frame(&mut self) -> Option<HFrame> {
+        self.borrow_mut().priority_update_frame()
+    }
+
+    fn priority_update_sent(&mut self) {
+        self.borrow_mut().priority_update_sent();
+    }
+
+    fn any(&self) -> &dyn Any {
+        self
+    }
+}
+
+impl SendStream for Rc<RefCell<WebTransportSession>> {
+    fn send(&mut self, conn: &mut Connection) -> Res<()> {
+        self.borrow_mut().send(conn)
+    }
+
+    fn send_data(&mut self, conn: &mut Connection, buf: &[u8]) -> Res<usize> {
+        self.borrow_mut().send_data(conn, buf)
+    }
+
+    fn has_data_to_send(&self) -> bool {
+        self.borrow_mut().has_data_to_send()
+    }
+
+    fn set_sendorder(&mut self, _conn: &mut Connection, _sendorder: Option<SendOrder>) -> Res<()> {
+        // Not relevant on session
+        Ok(())
+    }
+
+    fn set_fairness(&mut self, _conn: &mut Connection, _fairness: bool) -> Res<()> {
+        // Not relevant on session
+        Ok(())
+    }
+
+    fn stream_writable(&self) {}
+
+    fn done(&self) -> bool {
+        self.borrow_mut().done()
+    }
+
+    fn close(&mut self, conn: &mut Connection) -> Res<()> {
+        self.borrow_mut().close_session(conn, 0, "")
+    }
+
+    fn close_with_message(&mut self, conn: &mut Connection, error: u32, message: &str) -> Res<()> {
+        self.borrow_mut().close_session(conn, error, message)
+    }
+
+    fn handle_stop_sending(&mut self, close_type: CloseType) {
+        self.borrow_mut().close(close_type);
+    }
+}
+
+#[derive(Debug, Default)]
+struct WebTransportSessionListener {
+    headers: Option<(Vec<Header>, bool, bool)>,
+}
+
+impl WebTransportSessionListener {
+    fn set_headers(&mut self, headers: Vec<Header>, interim: bool, fin: bool) {
+        self.headers = Some((headers, interim, fin));
+    }
+
+    pub fn get_headers(&mut self) -> Option<(Vec<Header>, bool, bool)> {
+        mem::take(&mut self.headers)
+    }
+}
+
+impl RecvStreamEvents for Rc<RefCell<WebTransportSessionListener>> {}
+
+impl HttpRecvStreamEvents for Rc<RefCell<WebTransportSessionListener>> {
+    fn header_ready(
+        &self,
+        _stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    ) {
+        if !interim || fin {
+            self.borrow_mut().set_headers(headers, interim, fin);
+        }
+    }
+}
+
+impl SendStreamEvents for Rc<RefCell<WebTransportSessionListener>> {}
diff --git a/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_streams.rs b/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_streams.rs
new file mode 100644
index 0000000000..84dcd20618
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/extended_connect/webtransport_streams.rs
@@ -0,0 +1,271 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{cell::RefCell, rc::Rc};
+
+use neqo_common::Encoder;
+use neqo_transport::{Connection, RecvStreamStats, SendStreamStats, StreamId};
+
+use super::WebTransportSession;
+use crate::{
+    CloseType, Http3StreamInfo, Http3StreamType, ReceiveOutput, RecvStream, RecvStreamEvents, Res,
+    SendStream, SendStreamEvents, Stream,
+};
+
+pub const WEBTRANSPORT_UNI_STREAM: u64 = 0x54;
+pub const WEBTRANSPORT_STREAM: u64 = 0x41;
+
+#[derive(Debug)]
+pub(crate) struct WebTransportRecvStream {
+    stream_id: StreamId,
+    events: Box<dyn RecvStreamEvents>,
+    session: Rc<RefCell<WebTransportSession>>,
+    session_id: StreamId,
+    fin: bool,
+}
+
+impl WebTransportRecvStream {
+    pub fn new(
+        stream_id: StreamId,
+        session_id: StreamId,
+        events: Box<dyn RecvStreamEvents>,
+        session: Rc<RefCell<WebTransportSession>>,
+    ) -> Self {
+        Self {
+            stream_id,
+            events,
+            session_id,
+            session,
+            fin: false,
+        }
+    }
+
+    fn get_info(&self) -> Http3StreamInfo {
+        Http3StreamInfo::new(self.stream_id, self.stream_type())
+    }
+}
+
+impl Stream for WebTransportRecvStream {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::WebTransport(self.session_id)
+    }
+}
+
+impl RecvStream for WebTransportRecvStream {
+    fn receive(&mut self, _conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        self.events.data_readable(self.get_info());
+        Ok((ReceiveOutput::NoOutput, false))
+    }
+
+    fn reset(&mut self, close_type: CloseType) -> Res<()> {
+        if !matches!(close_type, CloseType::ResetApp(_)) {
+            self.events.recv_closed(self.get_info(), close_type);
+        }
+        self.session.borrow_mut().remove_recv_stream(self.stream_id);
+        Ok(())
+    }
+
+    fn read_data(&mut self, conn: &mut Connection, buf: &mut [u8]) -> Res<(usize, bool)> {
+        let (amount, fin) = conn.stream_recv(self.stream_id, buf)?;
+        self.fin = fin;
+        if fin {
+            self.session.borrow_mut().remove_recv_stream(self.stream_id);
+        }
+        Ok((amount, fin))
+    }
+
+    fn stats(&mut self, conn: &mut Connection) -> Res<RecvStreamStats> {
+        const TYPE_LEN_UNI: usize = Encoder::varint_len(WEBTRANSPORT_UNI_STREAM);
+        const TYPE_LEN_BIDI: usize = Encoder::varint_len(WEBTRANSPORT_STREAM);
+
+        let stream_header_size = if self.stream_id.is_server_initiated() {
+            let id_len = if self.stream_id.is_uni() {
+                TYPE_LEN_UNI
+            } else {
+                TYPE_LEN_BIDI
+            };
+            (id_len + Encoder::varint_len(self.session_id.as_u64())) as u64
+        } else {
+            0
+        };
+
+        let stats = conn.recv_stream_stats(self.stream_id)?;
+        if stream_header_size == 0 {
+            return Ok(stats);
+        }
+
+        let subtract_non_app_bytes =
+            |count: u64| -> u64 { count.saturating_sub(stream_header_size) };
+
+        let bytes_received = subtract_non_app_bytes(stats.bytes_received());
+        let bytes_read = subtract_non_app_bytes(stats.bytes_read());
+
+        Ok(RecvStreamStats::new(bytes_received, bytes_read))
+    }
+}
+
+#[derive(Debug, PartialEq)]
+enum WebTransportSenderStreamState {
+    SendingInit { buf: Vec<u8>, fin: bool },
+    SendingData,
+    Done,
+}
+
+#[derive(Debug)]
+pub(crate) struct WebTransportSendStream {
+    stream_id: StreamId,
+    state: WebTransportSenderStreamState,
+    events: Box<dyn SendStreamEvents>,
+    session: Rc<RefCell<WebTransportSession>>,
+    session_id: StreamId,
+}
+
+impl WebTransportSendStream {
+    pub fn new(
+        stream_id: StreamId,
+        session_id: StreamId,
+        events: Box<dyn SendStreamEvents>,
+        session: Rc<RefCell<WebTransportSession>>,
+        local: bool,
+    ) -> Self {
+        Self {
+            stream_id,
+            state: if local {
+                let mut d = Encoder::default();
+                if stream_id.is_uni() {
+                    d.encode_varint(WEBTRANSPORT_UNI_STREAM);
+                } else {
+                    d.encode_varint(WEBTRANSPORT_STREAM);
+                }
+                d.encode_varint(session_id.as_u64());
+                WebTransportSenderStreamState::SendingInit {
+                    buf: d.into(),
+                    fin: false,
+                }
+            } else {
+                WebTransportSenderStreamState::SendingData
+            },
+            events,
+            session_id,
+            session,
+        }
+    }
+
+    fn set_done(&mut self, close_type: CloseType) {
+        self.state = WebTransportSenderStreamState::Done;
+        self.events.send_closed(self.get_info(), close_type);
+        self.session.borrow_mut().remove_send_stream(self.stream_id);
+    }
+
+    fn get_info(&self) -> Http3StreamInfo {
+        Http3StreamInfo::new(self.stream_id, self.stream_type())
+    }
+}
+
+impl Stream for WebTransportSendStream {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::WebTransport(self.session_id)
+    }
+}
+
+impl SendStream for WebTransportSendStream {
+    fn send(&mut self, conn: &mut Connection) -> Res<()> {
+        if let WebTransportSenderStreamState::SendingInit { ref mut buf, fin } = self.state {
+            let sent = conn.stream_send(self.stream_id, &buf[..])?;
+            if sent == buf.len() {
+                if fin {
+                    conn.stream_close_send(self.stream_id)?;
+                    self.set_done(CloseType::Done);
+                } else {
+                    self.state = WebTransportSenderStreamState::SendingData;
+                }
+            } else {
+                let b = buf.split_off(sent);
+                *buf = b;
+            }
+        }
+        Ok(())
+    }
+
+    fn has_data_to_send(&self) -> bool {
+        matches!(
+            self.state,
+            WebTransportSenderStreamState::SendingInit { .. }
+        )
+    }
+
+    fn stream_writable(&self) {
+        self.events.data_writable(self.get_info());
+    }
+
+    fn done(&self) -> bool {
+        self.state == WebTransportSenderStreamState::Done
+    }
+
+    fn send_data(&mut self, conn: &mut Connection, buf: &[u8]) -> Res<usize> {
+        self.send(conn)?;
+        if self.state == WebTransportSenderStreamState::SendingData {
+            let sent = conn.stream_send(self.stream_id, buf)?;
+            Ok(sent)
+        } else {
+            Ok(0)
+        }
+    }
+
+    fn set_sendorder(&mut self, conn: &mut Connection, sendorder: Option<i64>) -> Res<()> {
+        conn.stream_sendorder(self.stream_id, sendorder)
+            .map_err(|_| crate::Error::InvalidStreamId)
+    }
+
+    fn set_fairness(&mut self, conn: &mut Connection, fairness: bool) -> Res<()> {
+        conn.stream_fairness(self.stream_id, fairness)
+            .map_err(|_| crate::Error::InvalidStreamId)
+    }
+
+    fn handle_stop_sending(&mut self, close_type: CloseType) {
+        self.set_done(close_type);
+    }
+
+    fn close(&mut self, conn: &mut Connection) -> Res<()> {
+        if let WebTransportSenderStreamState::SendingInit { ref mut fin, .. } = self.state {
+            *fin = true;
+        } else {
+            self.state = WebTransportSenderStreamState::Done;
+            conn.stream_close_send(self.stream_id)?;
+            self.set_done(CloseType::Done);
+        }
+        Ok(())
+    }
+
+    fn stats(&mut self, conn: &mut Connection) -> Res<SendStreamStats> {
+        const TYPE_LEN_UNI: usize = Encoder::varint_len(WEBTRANSPORT_UNI_STREAM);
+        const TYPE_LEN_BIDI: usize = Encoder::varint_len(WEBTRANSPORT_STREAM);
+
+        let stream_header_size = if self.stream_id.is_client_initiated() {
+            let id_len = if self.stream_id.is_uni() {
+                TYPE_LEN_UNI
+            } else {
+                TYPE_LEN_BIDI
+            };
+            (id_len + Encoder::varint_len(self.session_id.as_u64())) as u64
+        } else {
+            0
+        };
+
+        let stats = conn.send_stream_stats(self.stream_id)?;
+        if stream_header_size == 0 {
+            return Ok(stats);
+        }
+
+        let subtract_non_app_bytes =
+            |count: u64| -> u64 { count.saturating_sub(stream_header_size) };
+
+        let bytes_written = subtract_non_app_bytes(stats.bytes_written());
+        let bytes_sent = subtract_non_app_bytes(stats.bytes_sent());
+        let bytes_acked = subtract_non_app_bytes(stats.bytes_acked());
+        Ok(SendStreamStats::new(bytes_written, bytes_sent, bytes_acked))
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/features/mod.rs b/third_party/rust/neqo-http3/src/features/mod.rs
new file mode 100644
index 0000000000..34e21f50ac
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/features/mod.rs
@@ -0,0 +1,92 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{fmt::Debug, mem};
+
+use neqo_common::qtrace;
+
+use crate::{
+    client_events::Http3ClientEvents,
+    settings::{HSettingType, HSettings},
+};
+
+pub mod extended_connect;
+
+/// States:
+/// - `Disable` - it is not turned on for this connection.
+/// - `Negotiating` - the feature is enabled locally, but settings from the peer have not been
+///   received yet.
+/// - `Negotiated` - the settings have been received and both sides support the feature.
+/// - `NegotiationFailed` - the settings have been received and the peer does not support the
+///   feature.
+#[derive(Debug)]
+pub enum NegotiationState {
+    Disabled,
+    Negotiating {
+        feature_type: HSettingType,
+        listener: Option<Http3ClientEvents>,
+    },
+    Negotiated,
+    NegotiationFailed,
+}
+
+impl NegotiationState {
+    #[must_use]
+    pub fn new(enable: bool, feature_type: HSettingType) -> Self {
+        if enable {
+            Self::Negotiating {
+                feature_type,
+                listener: None,
+            }
+        } else {
+            Self::Disabled
+        }
+    }
+
+    pub fn set_listener(&mut self, new_listener: Http3ClientEvents) {
+        if let Self::Negotiating { listener, .. } = self {
+            *listener = Some(new_listener);
+        }
+    }
+
+    pub fn handle_settings(&mut self, settings: &HSettings) {
+        if !self.locally_enabled() {
+            return;
+        }
+
+        if let Self::Negotiating {
+            feature_type,
+            listener,
+        } = self
+        {
+            qtrace!(
+                "set_negotiated {:?} to {}",
+                feature_type,
+                settings.get(*feature_type)
+            );
+            let cb = mem::take(listener);
+            let ft = *feature_type;
+            *self = if settings.get(ft) == 1 {
+                Self::Negotiated
+            } else {
+                Self::NegotiationFailed
+            };
+            if let Some(l) = cb {
+                l.negotiation_done(ft, self.enabled());
+            }
+        }
+    }
+
+    #[must_use]
+    pub fn enabled(&self) -> bool {
+        matches!(self, &Self::Negotiated)
+    }
+
+    #[must_use]
+    pub fn locally_enabled(&self) -> bool {
+        !matches!(self, &Self::Disabled)
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/frames/hframe.rs b/third_party/rust/neqo-http3/src/frames/hframe.rs
new file mode 100644
index 0000000000..83e69ba894
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/hframe.rs
@@ -0,0 +1,227 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{fmt::Debug, io::Write};
+
+use neqo_common::{Decoder, Encoder};
+use neqo_crypto::random;
+use neqo_transport::StreamId;
+
+use crate::{frames::reader::FrameDecoder, settings::HSettings, Error, Priority, Res};
+
+pub(crate) type HFrameType = u64;
+
+pub const H3_FRAME_TYPE_DATA: HFrameType = 0x0;
+pub const H3_FRAME_TYPE_HEADERS: HFrameType = 0x1;
+pub const H3_FRAME_TYPE_CANCEL_PUSH: HFrameType = 0x3;
+pub const H3_FRAME_TYPE_SETTINGS: HFrameType = 0x4;
+pub const H3_FRAME_TYPE_PUSH_PROMISE: HFrameType = 0x5;
+pub const H3_FRAME_TYPE_GOAWAY: HFrameType = 0x7;
+pub const H3_FRAME_TYPE_MAX_PUSH_ID: HFrameType = 0xd;
+pub const H3_FRAME_TYPE_PRIORITY_UPDATE_REQUEST: HFrameType = 0xf0700;
+pub const H3_FRAME_TYPE_PRIORITY_UPDATE_PUSH: HFrameType = 0xf0701;
+
+pub const H3_RESERVED_FRAME_TYPES: &[HFrameType] = &[0x2, 0x6, 0x8, 0x9];
+
+// data for DATA frame is not read into HFrame::Data.
+#[derive(PartialEq, Eq, Debug)]
+pub enum HFrame {
+    Data {
+        len: u64, // length of the data
+    },
+    Headers {
+        header_block: Vec<u8>,
+    },
+    CancelPush {
+        push_id: u64,
+    },
+    Settings {
+        settings: HSettings,
+    },
+    PushPromise {
+        push_id: u64,
+        header_block: Vec<u8>,
+    },
+    Goaway {
+        stream_id: StreamId,
+    },
+    MaxPushId {
+        push_id: u64,
+    },
+    Grease,
+    PriorityUpdateRequest {
+        element_id: u64,
+        priority: Priority,
+    },
+    PriorityUpdatePush {
+        element_id: u64,
+        priority: Priority,
+    },
+}
+
+impl HFrame {
+    fn get_type(&self) -> HFrameType {
+        match self {
+            Self::Data { .. } => H3_FRAME_TYPE_DATA,
+            Self::Headers { .. } => H3_FRAME_TYPE_HEADERS,
+            Self::CancelPush { .. } => H3_FRAME_TYPE_CANCEL_PUSH,
+            Self::Settings { .. } => H3_FRAME_TYPE_SETTINGS,
+            Self::PushPromise { .. } => H3_FRAME_TYPE_PUSH_PROMISE,
+            Self::Goaway { .. } => H3_FRAME_TYPE_GOAWAY,
+            Self::MaxPushId { .. } => H3_FRAME_TYPE_MAX_PUSH_ID,
+            Self::PriorityUpdateRequest { .. } => H3_FRAME_TYPE_PRIORITY_UPDATE_REQUEST,
+            Self::PriorityUpdatePush { .. } => H3_FRAME_TYPE_PRIORITY_UPDATE_PUSH,
+            Self::Grease => {
+                let r = random(7);
+                Decoder::from(&r).decode_uint(7).unwrap() * 0x1f + 0x21
+            }
+        }
+    }
+
+    pub fn encode(&self, enc: &mut Encoder) {
+        enc.encode_varint(self.get_type());
+
+        match self {
+            Self::Data { len } => {
+                // DATA frame only encode the length here.
+                enc.encode_varint(*len);
+            }
+            Self::Headers { header_block } => {
+                enc.encode_vvec(header_block);
+            }
+            Self::CancelPush { push_id } => {
+                enc.encode_vvec_with(|enc_inner| {
+                    enc_inner.encode_varint(*push_id);
+                });
+            }
+            Self::Settings { settings } => {
+                settings.encode_frame_contents(enc);
+            }
+            Self::PushPromise {
+                push_id,
+                header_block,
+            } => {
+                enc.encode_varint((header_block.len() + (Encoder::varint_len(*push_id))) as u64);
+                enc.encode_varint(*push_id);
+                enc.encode(header_block);
+            }
+            Self::Goaway { stream_id } => {
+                enc.encode_vvec_with(|enc_inner| {
+                    enc_inner.encode_varint(stream_id.as_u64());
+                });
+            }
+            Self::MaxPushId { push_id } => {
+                enc.encode_vvec_with(|enc_inner| {
+                    enc_inner.encode_varint(*push_id);
+                });
+            }
+            Self::Grease => {
+                // Encode some number of random bytes.
+                let r = random(8);
+                enc.encode_vvec(&r[1..usize::from(1 + (r[0] & 0x7))]);
+            }
+            Self::PriorityUpdateRequest {
+                element_id,
+                priority,
+            }
+            | Self::PriorityUpdatePush {
+                element_id,
+                priority,
+            } => {
+                let mut update_frame = Encoder::new();
+                update_frame.encode_varint(*element_id);
+
+                let mut priority_enc: Vec<u8> = Vec::new();
+                write!(priority_enc, "{priority}").unwrap();
+
+                update_frame.encode(&priority_enc);
+                enc.encode_varint(update_frame.len() as u64);
+                enc.encode(update_frame.as_ref());
+            }
+        }
+    }
+}
+
+impl FrameDecoder<HFrame> for HFrame {
+    fn frame_type_allowed(frame_type: u64) -> Res<()> {
+        if H3_RESERVED_FRAME_TYPES.contains(&frame_type) {
+            return Err(Error::HttpFrameUnexpected);
+        }
+        Ok(())
+    }
+
+    fn decode(frame_type: u64, frame_len: u64, data: Option<&[u8]>) -> Res<Option<HFrame>> {
+        if frame_type == H3_FRAME_TYPE_DATA {
+            Ok(Some(HFrame::Data { len: frame_len }))
+        } else if let Some(payload) = data {
+            let mut dec = Decoder::from(payload);
+            Ok(match frame_type {
+                H3_FRAME_TYPE_DATA => unreachable!("DATA frame has been handled already."),
+                H3_FRAME_TYPE_HEADERS => Some(HFrame::Headers {
+                    header_block: dec.decode_remainder().to_vec(),
+                }),
+                H3_FRAME_TYPE_CANCEL_PUSH => Some(HFrame::CancelPush {
+                    push_id: dec.decode_varint().ok_or(Error::HttpFrame)?,
+                }),
+                H3_FRAME_TYPE_SETTINGS => {
+                    let mut settings = HSettings::default();
+                    settings.decode_frame_contents(&mut dec).map_err(|e| {
+                        if e == Error::HttpSettings {
+                            e
+                        } else {
+                            Error::HttpFrame
+                        }
+                    })?;
+                    Some(HFrame::Settings { settings })
+                }
+                H3_FRAME_TYPE_PUSH_PROMISE => Some(HFrame::PushPromise {
+                    push_id: dec.decode_varint().ok_or(Error::HttpFrame)?,
+                    header_block: dec.decode_remainder().to_vec(),
+                }),
+                H3_FRAME_TYPE_GOAWAY => Some(HFrame::Goaway {
+                    stream_id: StreamId::new(dec.decode_varint().ok_or(Error::HttpFrame)?),
+                }),
+                H3_FRAME_TYPE_MAX_PUSH_ID => Some(HFrame::MaxPushId {
+                    push_id: dec.decode_varint().ok_or(Error::HttpFrame)?,
+                }),
+                H3_FRAME_TYPE_PRIORITY_UPDATE_REQUEST | H3_FRAME_TYPE_PRIORITY_UPDATE_PUSH => {
+                    let element_id = dec.decode_varint().ok_or(Error::HttpFrame)?;
+                    let priority = dec.decode_remainder();
+                    let priority = Priority::from_bytes(priority)?;
+                    if frame_type == H3_FRAME_TYPE_PRIORITY_UPDATE_REQUEST {
+                        Some(HFrame::PriorityUpdateRequest {
+                            element_id,
+                            priority,
+                        })
+                    } else {
+                        Some(HFrame::PriorityUpdatePush {
+                            element_id,
+                            priority,
+                        })
+                    }
+                }
+                _ => None,
+            })
+        } else {
+            Ok(None)
+        }
+    }
+
+    fn is_known_type(frame_type: u64) -> bool {
+        matches!(
+            frame_type,
+            H3_FRAME_TYPE_DATA
+                | H3_FRAME_TYPE_HEADERS
+                | H3_FRAME_TYPE_CANCEL_PUSH
+                | H3_FRAME_TYPE_SETTINGS
+                | H3_FRAME_TYPE_PUSH_PROMISE
+                | H3_FRAME_TYPE_GOAWAY
+                | H3_FRAME_TYPE_MAX_PUSH_ID
+                | H3_FRAME_TYPE_PRIORITY_UPDATE_REQUEST
+                | H3_FRAME_TYPE_PRIORITY_UPDATE_PUSH
+        )
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/frames/mod.rs b/third_party/rust/neqo-http3/src/frames/mod.rs
new file mode 100644
index 0000000000..8b615fad01
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/mod.rs
@@ -0,0 +1,21 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub(crate) mod hframe;
+pub(crate) mod reader;
+pub(crate) mod wtframe;
+
+#[allow(unused_imports)]
+pub(crate) use hframe::{
+    HFrame, H3_FRAME_TYPE_HEADERS, H3_FRAME_TYPE_SETTINGS, H3_RESERVED_FRAME_TYPES,
+};
+pub(crate) use reader::{
+    FrameReader, StreamReaderConnectionWrapper, StreamReaderRecvStreamWrapper,
+};
+pub(crate) use wtframe::WebTransportFrame;
+
+#[cfg(test)]
+mod tests;
diff --git a/third_party/rust/neqo-http3/src/frames/reader.rs b/third_party/rust/neqo-http3/src/frames/reader.rs
new file mode 100644
index 0000000000..5017c666a4
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/reader.rs
@@ -0,0 +1,280 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{convert::TryFrom, fmt::Debug};
+
+use neqo_common::{
+    hex_with_len, qtrace, Decoder, IncrementalDecoderBuffer, IncrementalDecoderIgnore,
+    IncrementalDecoderUint,
+};
+use neqo_transport::{Connection, StreamId};
+
+use crate::{Error, RecvStream, Res};
+
+const MAX_READ_SIZE: usize = 4096;
+
+pub(crate) trait FrameDecoder<T> {
+    fn is_known_type(frame_type: u64) -> bool;
+    /// # Errors
+    ///
+    /// Returns `HttpFrameUnexpected` if frames is not alowed, i.e. is a `H3_RESERVED_FRAME_TYPES`.
+    fn frame_type_allowed(_frame_type: u64) -> Res<()> {
+        Ok(())
+    }
+
+    /// # Errors
+    ///
+    /// If a frame cannot be properly decoded.
+    fn decode(frame_type: u64, frame_len: u64, data: Option<&[u8]>) -> Res<Option<T>>;
+}
+
+pub(crate) trait StreamReader {
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    /// Return an error if the stream was closed on the transport layer, but that information is not
+    /// yet consumed on the  http/3 layer.
+    fn read_data(&mut self, buf: &mut [u8]) -> Res<(usize, bool)>;
+}
+
+pub(crate) struct StreamReaderConnectionWrapper<'a> {
+    conn: &'a mut Connection,
+    stream_id: StreamId,
+}
+
+impl<'a> StreamReaderConnectionWrapper<'a> {
+    pub fn new(conn: &'a mut Connection, stream_id: StreamId) -> Self {
+        Self { conn, stream_id }
+    }
+}
+
+impl<'a> StreamReader for StreamReaderConnectionWrapper<'a> {
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    fn read_data(&mut self, buf: &mut [u8]) -> Res<(usize, bool)> {
+        let res = self.conn.stream_recv(self.stream_id, buf)?;
+        Ok(res)
+    }
+}
+
+pub(crate) struct StreamReaderRecvStreamWrapper<'a> {
+    recv_stream: &'a mut Box<dyn RecvStream>,
+    conn: &'a mut Connection,
+}
+
+impl<'a> StreamReaderRecvStreamWrapper<'a> {
+    pub fn new(conn: &'a mut Connection, recv_stream: &'a mut Box<dyn RecvStream>) -> Self {
+        Self { recv_stream, conn }
+    }
+}
+
+impl<'a> StreamReader for StreamReaderRecvStreamWrapper<'a> {
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    fn read_data(&mut self, buf: &mut [u8]) -> Res<(usize, bool)> {
+        self.recv_stream.read_data(self.conn, buf)
+    }
+}
+
+#[derive(Clone, Debug)]
+enum FrameReaderState {
+    GetType { decoder: IncrementalDecoderUint },
+    GetLength { decoder: IncrementalDecoderUint },
+    GetData { decoder: IncrementalDecoderBuffer },
+    UnknownFrameDischargeData { decoder: IncrementalDecoderIgnore },
+}
+
+#[allow(clippy::module_name_repetitions)]
+#[derive(Debug)]
+pub(crate) struct FrameReader {
+    state: FrameReaderState,
+    frame_type: u64,
+    frame_len: u64,
+}
+
+impl Default for FrameReader {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl FrameReader {
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            state: FrameReaderState::GetType {
+                decoder: IncrementalDecoderUint::default(),
+            },
+            frame_type: 0,
+            frame_len: 0,
+        }
+    }
+
+    #[must_use]
+    pub fn new_with_type(frame_type: u64) -> Self {
+        Self {
+            state: FrameReaderState::GetLength {
+                decoder: IncrementalDecoderUint::default(),
+            },
+            frame_type,
+            frame_len: 0,
+        }
+    }
+
+    fn reset(&mut self) {
+        self.state = FrameReaderState::GetType {
+            decoder: IncrementalDecoderUint::default(),
+        };
+    }
+
+    fn min_remaining(&self) -> usize {
+        match &self.state {
+            FrameReaderState::GetType { decoder } | FrameReaderState::GetLength { decoder } => {
+                decoder.min_remaining()
+            }
+            FrameReaderState::GetData { decoder } => decoder.min_remaining(),
+            FrameReaderState::UnknownFrameDischargeData { decoder } => decoder.min_remaining(),
+        }
+    }
+
+    fn decoding_in_progress(&self) -> bool {
+        if let FrameReaderState::GetType { decoder } = &self.state {
+            decoder.decoding_in_progress()
+        } else {
+            true
+        }
+    }
+
+    /// returns true if quic stream was closed.
+    ///
+    /// # Errors
+    ///
+    /// May return `HttpFrame` if a frame cannot be decoded.
+    /// and `TransportStreamDoesNotExist` if `stream_recv` fails.
+    pub fn receive<T: FrameDecoder<T>>(
+        &mut self,
+        stream_reader: &mut dyn StreamReader,
+    ) -> Res<(Option<T>, bool)> {
+        loop {
+            let to_read = std::cmp::min(self.min_remaining(), MAX_READ_SIZE);
+            let mut buf = vec![0; to_read];
+            let (output, read, fin) = match stream_reader
+                .read_data(&mut buf)
+                .map_err(|e| Error::map_stream_recv_errors(&e))?
+            {
+                (0, f) => (None, false, f),
+                (amount, f) => {
+                    qtrace!("FrameReader::receive: reading {} byte, fin={}", amount, f);
+                    (self.consume::<T>(Decoder::from(&buf[..amount]))?, true, f)
+                }
+            };
+
+            if output.is_some() {
+                break Ok((output, fin));
+            }
+
+            if fin {
+                if self.decoding_in_progress() {
+                    break Err(Error::HttpFrame);
+                }
+                break Ok((None, fin));
+            }
+
+            if !read {
+                // There was no new data, exit the loop.
+                break Ok((None, false));
+            }
+        }
+    }
+
+    /// # Errors
+    ///
+    /// May return `HttpFrame` if a frame cannot be decoded.
+    fn consume<T: FrameDecoder<T>>(&mut self, mut input: Decoder) -> Res<Option<T>> {
+        match &mut self.state {
+            FrameReaderState::GetType { decoder } => {
+                if let Some(v) = decoder.consume(&mut input) {
+                    qtrace!("FrameReader::receive: read frame type {}", v);
+                    self.frame_type_decoded::<T>(v)?;
+                }
+            }
+            FrameReaderState::GetLength { decoder } => {
+                if let Some(len) = decoder.consume(&mut input) {
+                    qtrace!(
+                        "FrameReader::receive: frame type {} length {}",
+                        self.frame_type,
+                        len
+                    );
+                    return self.frame_length_decoded::<T>(len);
+                }
+            }
+            FrameReaderState::GetData { decoder } => {
+                if let Some(data) = decoder.consume(&mut input) {
+                    qtrace!(
+                        "received frame {}: {}",
+                        self.frame_type,
+                        hex_with_len(&data[..])
+                    );
+                    return self.frame_data_decoded::<T>(&data);
+                }
+            }
+            FrameReaderState::UnknownFrameDischargeData { decoder } => {
+                if decoder.consume(&mut input) {
+                    self.reset();
+                }
+            }
+        }
+        Ok(None)
+    }
+}
+
+impl FrameReader {
+    fn frame_type_decoded<T: FrameDecoder<T>>(&mut self, frame_type: u64) -> Res<()> {
+        T::frame_type_allowed(frame_type)?;
+        self.frame_type = frame_type;
+        self.state = FrameReaderState::GetLength {
+            decoder: IncrementalDecoderUint::default(),
+        };
+        Ok(())
+    }
+
+    fn frame_length_decoded<T: FrameDecoder<T>>(&mut self, len: u64) -> Res<Option<T>> {
+        self.frame_len = len;
+        if let Some(f) = T::decode(
+            self.frame_type,
+            self.frame_len,
+            if len > 0 { None } else { Some(&[]) },
+        )? {
+            self.reset();
+            return Ok(Some(f));
+        } else if T::is_known_type(self.frame_type) {
+            self.state = FrameReaderState::GetData {
+                decoder: IncrementalDecoderBuffer::new(
+                    usize::try_from(len).or(Err(Error::HttpFrame))?,
+                ),
+            };
+        } else if self.frame_len == 0 {
+            self.reset();
+        } else {
+            self.state = FrameReaderState::UnknownFrameDischargeData {
+                decoder: IncrementalDecoderIgnore::new(
+                    usize::try_from(len).or(Err(Error::HttpFrame))?,
+                ),
+            };
+        }
+        Ok(None)
+    }
+
+    fn frame_data_decoded<T: FrameDecoder<T>>(&mut self, data: &[u8]) -> Res<Option<T>> {
+        let res = T::decode(self.frame_type, self.frame_len, Some(data))?;
+        self.reset();
+        Ok(res)
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/frames/tests/hframe.rs b/third_party/rust/neqo-http3/src/frames/tests/hframe.rs
new file mode 100644
index 0000000000..3da7e7fc36
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/tests/hframe.rs
@@ -0,0 +1,116 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use neqo_common::{Decoder, Encoder};
+use neqo_transport::StreamId;
+use test_fixture::fixture_init;
+
+use super::enc_dec_hframe;
+use crate::{
+    frames::HFrame,
+    settings::{HSetting, HSettingType, HSettings},
+    Priority,
+};
+
+#[test]
+fn test_data_frame() {
+    let f = HFrame::Data { len: 3 };
+    enc_dec_hframe(&f, "0003010203", 3);
+}
+
+#[test]
+fn test_headers_frame() {
+    let f = HFrame::Headers {
+        header_block: vec![0x01, 0x02, 0x03],
+    };
+    enc_dec_hframe(&f, "0103010203", 0);
+}
+
+#[test]
+fn test_cancel_push_frame4() {
+    let f = HFrame::CancelPush { push_id: 5 };
+    enc_dec_hframe(&f, "030105", 0);
+}
+
+#[test]
+fn test_settings_frame4() {
+    let f = HFrame::Settings {
+        settings: HSettings::new(&[HSetting::new(HSettingType::MaxHeaderListSize, 4)]),
+    };
+    enc_dec_hframe(&f, "04020604", 0);
+}
+
+#[test]
+fn test_push_promise_frame4() {
+    let f = HFrame::PushPromise {
+        push_id: 4,
+        header_block: vec![0x61, 0x62, 0x63, 0x64],
+    };
+    enc_dec_hframe(&f, "05050461626364", 0);
+}
+
+#[test]
+fn test_goaway_frame4() {
+    let f = HFrame::Goaway {
+        stream_id: StreamId::new(5),
+    };
+    enc_dec_hframe(&f, "070105", 0);
+}
+
+#[test]
+fn grease() {
+    fn make_grease() -> u64 {
+        let mut enc = Encoder::default();
+        HFrame::Grease.encode(&mut enc);
+        let mut dec = Decoder::from(&enc);
+        let ft = dec.decode_varint().unwrap();
+        assert_eq!((ft - 0x21) % 0x1f, 0);
+        let body = dec.decode_vvec().unwrap();
+        assert!(body.len() <= 7);
+        ft
+    }
+
+    fixture_init();
+    let t1 = make_grease();
+    let t2 = make_grease();
+    assert_ne!(t1, t2);
+}
+
+#[test]
+fn test_priority_update_request_default() {
+    let f = HFrame::PriorityUpdateRequest {
+        element_id: 6,
+        priority: Priority::default(),
+    };
+    enc_dec_hframe(&f, "800f07000106", 0);
+}
+
+#[test]
+fn test_priority_update_request_incremental_default() {
+    let f = HFrame::PriorityUpdateRequest {
+        element_id: 7,
+        priority: Priority::new(6, false),
+    };
+    enc_dec_hframe(&f, "800f07000407753d36", 0); // "u=6"
+}
+
+#[test]
+fn test_priority_update_request_urgency_default() {
+    let f = HFrame::PriorityUpdateRequest {
+        element_id: 8,
+        priority: Priority::new(3, true),
+    };
+    enc_dec_hframe(&f, "800f0700020869", 0); // "i"
+}
+
+#[test]
+fn test_priority_update_push_default() {
+    let f = HFrame::PriorityUpdatePush {
+        element_id: 10,
+        priority: Priority::default(),
+    };
+    enc_dec_hframe(&f, "800f0701010a", 0);
+}
diff --git a/third_party/rust/neqo-http3/src/frames/tests/mod.rs b/third_party/rust/neqo-http3/src/frames/tests/mod.rs
new file mode 100644
index 0000000000..33eea5497a
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/tests/mod.rs
@@ -0,0 +1,84 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem;
+
+use neqo_common::Encoder;
+use neqo_crypto::AuthenticationStatus;
+use neqo_transport::StreamType;
+use test_fixture::{default_client, default_server, now};
+
+use crate::frames::{
+    reader::FrameDecoder, FrameReader, HFrame, StreamReaderConnectionWrapper, WebTransportFrame,
+};
+
+#[allow(clippy::many_single_char_names)]
+pub(crate) fn enc_dec<T: FrameDecoder<T>>(d: &Encoder, st: &str, remaining: usize) -> T {
+    // For data, headers and push_promise we do not read all bytes from the buffer
+    let d2 = Encoder::from_hex(st);
+    assert_eq!(d.as_ref(), &d2.as_ref()[..d.as_ref().len()]);
+
+    let mut conn_c = default_client();
+    let mut conn_s = default_server();
+    let out = conn_c.process(None, now());
+    let out = conn_s.process(out.as_dgram_ref(), now());
+    let out = conn_c.process(out.as_dgram_ref(), now());
+    mem::drop(conn_s.process(out.as_dgram_ref(), now()));
+    conn_c.authenticated(AuthenticationStatus::Ok, now());
+    let out = conn_c.process(None, now());
+    mem::drop(conn_s.process(out.as_dgram_ref(), now()));
+
+    // create a stream
+    let stream_id = conn_s.stream_create(StreamType::BiDi).unwrap();
+
+    let mut fr: FrameReader = FrameReader::new();
+
+    // conver string into u8 vector
+    let buf = Encoder::from_hex(st);
+    conn_s.stream_send(stream_id, buf.as_ref()).unwrap();
+    let out = conn_s.process(None, now());
+    mem::drop(conn_c.process(out.as_dgram_ref(), now()));
+
+    let (frame, fin) = fr
+        .receive::<T>(&mut StreamReaderConnectionWrapper::new(
+            &mut conn_c,
+            stream_id,
+        ))
+        .unwrap();
+    assert!(!fin);
+    assert!(frame.is_some());
+
+    // Check remaining data.
+    let mut buf = [0_u8; 100];
+    let (amount, _) = conn_c.stream_recv(stream_id, &mut buf).unwrap();
+    assert_eq!(amount, remaining);
+
+    frame.unwrap()
+}
+
+pub fn enc_dec_hframe(f: &HFrame, st: &str, remaining: usize) {
+    let mut d = Encoder::default();
+
+    f.encode(&mut d);
+
+    let frame = enc_dec::<HFrame>(&d, st, remaining);
+
+    assert_eq!(*f, frame);
+}
+
+pub fn enc_dec_wtframe(f: &WebTransportFrame, st: &str, remaining: usize) {
+    let mut d = Encoder::default();
+
+    f.encode(&mut d);
+
+    let frame = enc_dec::<WebTransportFrame>(&d, st, remaining);
+
+    assert_eq!(*f, frame);
+}
+
+mod hframe;
+mod reader;
+mod wtframe;
diff --git a/third_party/rust/neqo-http3/src/frames/tests/reader.rs b/third_party/rust/neqo-http3/src/frames/tests/reader.rs
new file mode 100644
index 0000000000..fed1477ba4
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/tests/reader.rs
@@ -0,0 +1,518 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{fmt::Debug, mem};
+
+use neqo_common::Encoder;
+use neqo_transport::{Connection, StreamId, StreamType};
+use test_fixture::{connect, now};
+
+use crate::{
+    frames::{
+        reader::FrameDecoder, FrameReader, HFrame, StreamReaderConnectionWrapper, WebTransportFrame,
+    },
+    settings::{HSetting, HSettingType, HSettings},
+    Error,
+};
+
+struct FrameReaderTest {
+    pub fr: FrameReader,
+    pub conn_c: Connection,
+    pub conn_s: Connection,
+    pub stream_id: StreamId,
+}
+
+impl FrameReaderTest {
+    pub fn new() -> Self {
+        let (conn_c, mut conn_s) = connect();
+        let stream_id = conn_s.stream_create(StreamType::BiDi).unwrap();
+        Self {
+            fr: FrameReader::new(),
+            conn_c,
+            conn_s,
+            stream_id,
+        }
+    }
+
+    fn process<T: FrameDecoder<T>>(&mut self, v: &[u8]) -> Option<T> {
+        self.conn_s.stream_send(self.stream_id, v).unwrap();
+        let out = self.conn_s.process(None, now());
+        mem::drop(self.conn_c.process(out.as_dgram_ref(), now()));
+        let (frame, fin) = self
+            .fr
+            .receive::<T>(&mut StreamReaderConnectionWrapper::new(
+                &mut self.conn_c,
+                self.stream_id,
+            ))
+            .unwrap();
+        assert!(!fin);
+        frame
+    }
+}
+
+// Test receiving byte by byte for a SETTINGS frame.
+#[test]
+fn test_frame_reading_with_stream_settings1() {
+    let mut fr = FrameReaderTest::new();
+
+    // Send and read settings frame 040406040804
+    assert!(fr.process::<HFrame>(&[0x4]).is_none());
+    assert!(fr.process::<HFrame>(&[0x4]).is_none());
+    assert!(fr.process::<HFrame>(&[0x6]).is_none());
+    assert!(fr.process::<HFrame>(&[0x4]).is_none());
+    assert!(fr.process::<HFrame>(&[0x8]).is_none());
+    let frame = fr.process(&[0x4]);
+
+    assert!(frame.is_some());
+    if let HFrame::Settings { settings } = frame.unwrap() {
+        assert!(settings.len() == 1);
+        assert!(settings[0] == HSetting::new(HSettingType::MaxHeaderListSize, 4));
+    } else {
+        panic!("wrong frame type");
+    }
+}
+
+// Test receiving byte by byte for a SETTINGS frame with larger varints
+#[test]
+fn test_frame_reading_with_stream_settings2() {
+    let mut fr = FrameReaderTest::new();
+
+    // Read settings frame 400406064004084100
+    for i in &[0x40, 0x04, 0x06, 0x06, 0x40, 0x04, 0x08, 0x41] {
+        assert!(fr.process::<HFrame>(&[*i]).is_none());
+    }
+    let frame = fr.process(&[0x0]);
+
+    assert!(frame.is_some());
+    if let HFrame::Settings { settings } = frame.unwrap() {
+        assert!(settings.len() == 1);
+        assert!(settings[0] == HSetting::new(HSettingType::MaxHeaderListSize, 4));
+    } else {
+        panic!("wrong frame type");
+    }
+}
+
+// Test receiving byte by byte for a PUSH_PROMISE frame.
+#[test]
+fn test_frame_reading_with_stream_push_promise() {
+    let mut fr = FrameReaderTest::new();
+
+    // Read push-promise frame 05054101010203
+    for i in &[0x05, 0x05, 0x41, 0x01, 0x01, 0x02] {
+        assert!(fr.process::<HFrame>(&[*i]).is_none());
+    }
+    let frame = fr.process(&[0x3]);
+
+    assert!(frame.is_some());
+    if let HFrame::PushPromise {
+        push_id,
+        header_block,
+    } = frame.unwrap()
+    {
+        assert_eq!(push_id, 257);
+        assert_eq!(header_block, &[0x1, 0x2, 0x3]);
+    } else {
+        panic!("wrong frame type");
+    }
+}
+
+// Test DATA
+#[test]
+fn test_frame_reading_with_stream_data() {
+    let mut fr = FrameReaderTest::new();
+
+    // Read data frame 0003010203
+    let frame = fr.process(&[0x0, 0x3, 0x1, 0x2, 0x3]).unwrap();
+    assert!(matches!(frame, HFrame::Data { len } if len == 3));
+
+    // payloead is still on the stream.
+    // assert that we have 3 bytes in the stream
+    let mut buf = [0_u8; 100];
+    let (amount, _) = fr.conn_c.stream_recv(fr.stream_id, &mut buf).unwrap();
+    assert_eq!(amount, 3);
+}
+
+// Test an unknown frame
+#[test]
+fn test_unknown_frame() {
+    // Construct an unknown frame.
+    const UNKNOWN_FRAME_LEN: usize = 832;
+
+    let mut fr = FrameReaderTest::new();
+
+    let mut enc = Encoder::with_capacity(UNKNOWN_FRAME_LEN + 4);
+    enc.encode_varint(1028_u64); // Arbitrary type.
+    enc.encode_varint(UNKNOWN_FRAME_LEN as u64);
+    let mut buf: Vec<_> = enc.into();
+    buf.resize(UNKNOWN_FRAME_LEN + buf.len(), 0);
+    assert!(fr.process::<HFrame>(&buf).is_none());
+
+    // now receive a CANCEL_PUSH fram to see that frame reader is ok.
+    let frame = fr.process(&[0x03, 0x01, 0x05]);
+    assert!(frame.is_some());
+    if let HFrame::CancelPush { push_id } = frame.unwrap() {
+        assert!(push_id == 5);
+    } else {
+        panic!("wrong frame type");
+    }
+}
+
+// Test receiving byte by byte for a WT_FRAME_CLOSE_SESSION frame.
+#[test]
+fn test_frame_reading_with_stream_wt_close_session() {
+    let mut fr = FrameReaderTest::new();
+
+    // Read CloseSession frame 6843090000000548656c6c6f
+    for i in &[
+        0x68, 0x43, 0x09, 0x00, 0x00, 0x00, 0x05, 0x48, 0x65, 0x6c, 0x6c,
+    ] {
+        assert!(fr.process::<WebTransportFrame>(&[*i]).is_none());
+    }
+    let frame = fr.process::<WebTransportFrame>(&[0x6f]);
+
+    assert!(frame.is_some());
+    let WebTransportFrame::CloseSession { error, message } = frame.unwrap();
+    assert_eq!(error, 5);
+    assert_eq!(message, "Hello".to_string());
+}
+
+// Test an unknown frame for WebTransportFrames.
+#[test]
+fn test_unknown_wt_frame() {
+    // Construct an unknown frame.
+    const UNKNOWN_FRAME_LEN: usize = 832;
+
+    let mut fr = FrameReaderTest::new();
+
+    let mut enc = Encoder::with_capacity(UNKNOWN_FRAME_LEN + 4);
+    enc.encode_varint(1028_u64); // Arbitrary type.
+    enc.encode_varint(UNKNOWN_FRAME_LEN as u64);
+    let mut buf: Vec<_> = enc.into();
+    buf.resize(UNKNOWN_FRAME_LEN + buf.len(), 0);
+    assert!(fr.process::<WebTransportFrame>(&buf).is_none());
+
+    // now receive a WT_FRAME_CLOSE_SESSION fram to see that frame reader is ok.
+    let frame = fr.process(&[
+        0x68, 0x43, 0x09, 0x00, 0x00, 0x00, 0x05, 0x48, 0x65, 0x6c, 0x6c, 0x6f,
+    ]);
+    assert!(frame.is_some());
+    let WebTransportFrame::CloseSession { error, message } = frame.unwrap();
+    assert_eq!(error, 5);
+    assert_eq!(message, "Hello".to_string());
+}
+
+enum FrameReadingTestSend {
+    OnlyData,
+    DataWithFin,
+    DataThenFin,
+}
+
+enum FrameReadingTestExpect {
+    Error,
+    Incomplete,
+    FrameComplete,
+    FrameAndStreamComplete,
+    StreamDoneWithoutFrame,
+}
+
+fn test_reading_frame<T: FrameDecoder<T> + PartialEq + Debug>(
+    buf: &[u8],
+    test_to_send: &FrameReadingTestSend,
+    expected_result: &FrameReadingTestExpect,
+) {
+    let mut fr = FrameReaderTest::new();
+
+    fr.conn_s.stream_send(fr.stream_id, buf).unwrap();
+    if let FrameReadingTestSend::DataWithFin = test_to_send {
+        fr.conn_s.stream_close_send(fr.stream_id).unwrap();
+    }
+
+    let out = fr.conn_s.process(None, now());
+    mem::drop(fr.conn_c.process(out.as_dgram_ref(), now()));
+
+    if let FrameReadingTestSend::DataThenFin = test_to_send {
+        fr.conn_s.stream_close_send(fr.stream_id).unwrap();
+        let out = fr.conn_s.process(None, now());
+        mem::drop(fr.conn_c.process(out.as_dgram_ref(), now()));
+    }
+
+    let rv = fr.fr.receive::<T>(&mut StreamReaderConnectionWrapper::new(
+        &mut fr.conn_c,
+        fr.stream_id,
+    ));
+
+    match expected_result {
+        FrameReadingTestExpect::Error => assert_eq!(Err(Error::HttpFrame), rv),
+        FrameReadingTestExpect::Incomplete => {
+            assert_eq!(Ok((None, false)), rv);
+        }
+        FrameReadingTestExpect::FrameComplete => {
+            let (f, fin) = rv.unwrap();
+            assert!(!fin);
+            assert!(f.is_some());
+        }
+        FrameReadingTestExpect::FrameAndStreamComplete => {
+            let (f, fin) = rv.unwrap();
+            assert!(fin);
+            assert!(f.is_some());
+        }
+        FrameReadingTestExpect::StreamDoneWithoutFrame => {
+            let (f, fin) = rv.unwrap();
+            assert!(fin);
+            assert!(f.is_none());
+        }
+    };
+}
+
+#[test]
+fn test_complete_and_incomplete_unknown_frame() {
+    // Construct an unknown frame.
+    const UNKNOWN_FRAME_LEN: usize = 832;
+    let mut enc = Encoder::with_capacity(UNKNOWN_FRAME_LEN + 4);
+    enc.encode_varint(1028_u64); // Arbitrary type.
+    enc.encode_varint(UNKNOWN_FRAME_LEN as u64);
+    let mut buf: Vec<_> = enc.into();
+    buf.resize(UNKNOWN_FRAME_LEN + buf.len(), 0);
+
+    let len = std::cmp::min(buf.len() - 1, 10);
+    for i in 1..len {
+        test_reading_frame::<HFrame>(
+            &buf[..i],
+            &FrameReadingTestSend::OnlyData,
+            &FrameReadingTestExpect::Incomplete,
+        );
+        test_reading_frame::<HFrame>(
+            &buf[..i],
+            &FrameReadingTestSend::DataWithFin,
+            &FrameReadingTestExpect::Error,
+        );
+        test_reading_frame::<HFrame>(
+            &buf[..i],
+            &FrameReadingTestSend::DataThenFin,
+            &FrameReadingTestExpect::Error,
+        );
+    }
+    test_reading_frame::<HFrame>(
+        &buf,
+        &FrameReadingTestSend::OnlyData,
+        &FrameReadingTestExpect::Incomplete,
+    );
+    test_reading_frame::<HFrame>(
+        &buf,
+        &FrameReadingTestSend::DataWithFin,
+        &FrameReadingTestExpect::StreamDoneWithoutFrame,
+    );
+    test_reading_frame::<HFrame>(
+        &buf,
+        &FrameReadingTestSend::DataThenFin,
+        &FrameReadingTestExpect::StreamDoneWithoutFrame,
+    );
+}
+
+// if we read more than done_state bytes FrameReader will be in done state.
+fn test_complete_and_incomplete_frame<T: FrameDecoder<T> + PartialEq + Debug>(
+    buf: &[u8],
+    done_state: usize,
+) {
+    use std::cmp::Ordering;
+    // Let's consume partial frames. It is enough to test partal frames
+    // up to 10 byte. 10 byte is greater than frame type and frame
+    // length and bit of data.
+    let len = std::cmp::min(buf.len() - 1, 10);
+    for i in 1..len {
+        test_reading_frame::<T>(
+            &buf[..i],
+            &FrameReadingTestSend::OnlyData,
+            if i >= done_state {
+                &FrameReadingTestExpect::FrameComplete
+            } else {
+                &FrameReadingTestExpect::Incomplete
+            },
+        );
+        test_reading_frame::<T>(
+            &buf[..i],
+            &FrameReadingTestSend::DataWithFin,
+            match i.cmp(&done_state) {
+                Ordering::Greater => &FrameReadingTestExpect::FrameComplete,
+                Ordering::Equal => &FrameReadingTestExpect::FrameAndStreamComplete,
+                Ordering::Less => &FrameReadingTestExpect::Error,
+            },
+        );
+        test_reading_frame::<T>(
+            &buf[..i],
+            &FrameReadingTestSend::DataThenFin,
+            match i.cmp(&done_state) {
+                Ordering::Greater => &FrameReadingTestExpect::FrameComplete,
+                Ordering::Equal => &FrameReadingTestExpect::FrameAndStreamComplete,
+                Ordering::Less => &FrameReadingTestExpect::Error,
+            },
+        );
+    }
+    test_reading_frame::<T>(
+        buf,
+        &FrameReadingTestSend::OnlyData,
+        &FrameReadingTestExpect::FrameComplete,
+    );
+    test_reading_frame::<T>(
+        buf,
+        &FrameReadingTestSend::DataWithFin,
+        if buf.len() == done_state {
+            &FrameReadingTestExpect::FrameAndStreamComplete
+        } else {
+            &FrameReadingTestExpect::FrameComplete
+        },
+    );
+    test_reading_frame::<T>(
+        buf,
+        &FrameReadingTestSend::DataThenFin,
+        if buf.len() == done_state {
+            &FrameReadingTestExpect::FrameAndStreamComplete
+        } else {
+            &FrameReadingTestExpect::FrameComplete
+        },
+    );
+}
+
+#[test]
+fn test_complete_and_incomplete_frames() {
+    const FRAME_LEN: usize = 10;
+    const HEADER_BLOCK: &[u8] = &[0x01, 0x02, 0x03, 0x04];
+
+    // H3_FRAME_TYPE_DATA len=0
+    let f = HFrame::Data { len: 0 };
+    let mut enc = Encoder::with_capacity(2);
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, 2);
+
+    // H3_FRAME_TYPE_DATA len=FRAME_LEN
+    let f = HFrame::Data {
+        len: FRAME_LEN as u64,
+    };
+    let mut enc = Encoder::with_capacity(2);
+    f.encode(&mut enc);
+    let mut buf: Vec<_> = enc.into();
+    buf.resize(FRAME_LEN + buf.len(), 0);
+    test_complete_and_incomplete_frame::<HFrame>(&buf, 2);
+
+    // H3_FRAME_TYPE_HEADERS empty header block
+    let f = HFrame::Headers {
+        header_block: Vec::new(),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, 2);
+
+    // H3_FRAME_TYPE_HEADERS
+    let f = HFrame::Headers {
+        header_block: HEADER_BLOCK.to_vec(),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+
+    // H3_FRAME_TYPE_CANCEL_PUSH
+    let f = HFrame::CancelPush { push_id: 5 };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+
+    // H3_FRAME_TYPE_SETTINGS
+    let f = HFrame::Settings {
+        settings: HSettings::new(&[HSetting::new(HSettingType::MaxHeaderListSize, 4)]),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+
+    // H3_FRAME_TYPE_PUSH_PROMISE
+    let f = HFrame::PushPromise {
+        push_id: 4,
+        header_block: HEADER_BLOCK.to_vec(),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+
+    // H3_FRAME_TYPE_GOAWAY
+    let f = HFrame::Goaway {
+        stream_id: StreamId::new(5),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+
+    // H3_FRAME_TYPE_MAX_PUSH_ID
+    let f = HFrame::MaxPushId { push_id: 5 };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<HFrame>(&buf, buf.len());
+}
+
+#[test]
+fn test_complete_and_incomplete_wt_frames() {
+    // H3_FRAME_TYPE_MAX_PUSH_ID
+    let f = WebTransportFrame::CloseSession {
+        error: 5,
+        message: "Hello".to_string(),
+    };
+    let mut enc = Encoder::default();
+    f.encode(&mut enc);
+    let buf: Vec<_> = enc.into();
+    test_complete_and_incomplete_frame::<WebTransportFrame>(&buf, buf.len());
+}
+
+// Test closing a stream before any frame is sent should not cause an error.
+#[test]
+fn test_frame_reading_when_stream_is_closed_before_sending_data() {
+    let mut fr = FrameReaderTest::new();
+
+    fr.conn_s.stream_send(fr.stream_id, &[0x00]).unwrap();
+    let out = fr.conn_s.process(None, now());
+    mem::drop(fr.conn_c.process(out.as_dgram_ref(), now()));
+
+    assert_eq!(Ok(()), fr.conn_c.stream_close_send(fr.stream_id));
+    let out = fr.conn_c.process(None, now());
+    mem::drop(fr.conn_s.process(out.as_dgram_ref(), now()));
+    assert_eq!(
+        Ok((None, true)),
+        fr.fr
+            .receive::<HFrame>(&mut StreamReaderConnectionWrapper::new(
+                &mut fr.conn_s,
+                fr.stream_id
+            ))
+    );
+}
+
+// Test closing a stream before any frame is sent should not cause an error.
+// This is the same as the previous just for WebTransportFrame.
+#[test]
+fn test_wt_frame_reading_when_stream_is_closed_before_sending_data() {
+    let mut fr = FrameReaderTest::new();
+
+    fr.conn_s.stream_send(fr.stream_id, &[0x00]).unwrap();
+    let out = fr.conn_s.process(None, now());
+    mem::drop(fr.conn_c.process(out.as_dgram_ref(), now()));
+
+    assert_eq!(Ok(()), fr.conn_c.stream_close_send(fr.stream_id));
+    let out = fr.conn_c.process(None, now());
+    mem::drop(fr.conn_s.process(out.as_dgram_ref(), now()));
+    assert_eq!(
+        Ok((None, true)),
+        fr.fr
+            .receive::<WebTransportFrame>(&mut StreamReaderConnectionWrapper::new(
+                &mut fr.conn_s,
+                fr.stream_id
+            ))
+    );
+}
diff --git a/third_party/rust/neqo-http3/src/frames/tests/wtframe.rs b/third_party/rust/neqo-http3/src/frames/tests/wtframe.rs
new file mode 100644
index 0000000000..b6470a89cf
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/tests/wtframe.rs
@@ -0,0 +1,17 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use super::enc_dec_wtframe;
+use crate::frames::WebTransportFrame;
+
+#[test]
+fn test_wt_close_session() {
+    let f = WebTransportFrame::CloseSession {
+        error: 5,
+        message: "Hello".to_string(),
+    };
+    enc_dec_wtframe(&f, "6843090000000548656c6c6f", 0);
+}
diff --git a/third_party/rust/neqo-http3/src/frames/wtframe.rs b/third_party/rust/neqo-http3/src/frames/wtframe.rs
new file mode 100644
index 0000000000..deb7a026a0
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/wtframe.rs
@@ -0,0 +1,62 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::convert::TryFrom;
+
+use neqo_common::{Decoder, Encoder};
+
+use crate::{frames::reader::FrameDecoder, Error, Res};
+
+pub(crate) type WebTransportFrameType = u64;
+
+const WT_FRAME_CLOSE_SESSION: WebTransportFrameType = 0x2843;
+const WT_FRAME_CLOSE_MAX_MESSAGE_SIZE: u64 = 1024;
+
+#[derive(PartialEq, Eq, Debug)]
+pub enum WebTransportFrame {
+    CloseSession { error: u32, message: String },
+}
+
+impl WebTransportFrame {
+    pub fn encode(&self, enc: &mut Encoder) {
+        enc.encode_varint(WT_FRAME_CLOSE_SESSION);
+        let WebTransportFrame::CloseSession { error, message } = &self;
+        enc.encode_varint(4 + message.len() as u64);
+        enc.encode_uint(4, *error);
+        enc.encode(message.as_bytes());
+    }
+}
+
+impl FrameDecoder<WebTransportFrame> for WebTransportFrame {
+    fn decode(
+        frame_type: u64,
+        frame_len: u64,
+        data: Option<&[u8]>,
+    ) -> Res<Option<WebTransportFrame>> {
+        if let Some(payload) = data {
+            let mut dec = Decoder::from(payload);
+            if frame_type == WT_FRAME_CLOSE_SESSION {
+                if frame_len > WT_FRAME_CLOSE_MAX_MESSAGE_SIZE + 4 {
+                    return Err(Error::HttpMessageError);
+                }
+                let error =
+                    u32::try_from(dec.decode_uint(4).ok_or(Error::HttpMessageError)?).unwrap();
+                let Ok(message) = String::from_utf8(dec.decode_remainder().to_vec()) else {
+                    return Err(Error::HttpMessageError);
+                };
+                Ok(Some(WebTransportFrame::CloseSession { error, message }))
+            } else {
+                Ok(None)
+            }
+        } else {
+            Ok(None)
+        }
+    }
+
+    fn is_known_type(frame_type: u64) -> bool {
+        frame_type == WT_FRAME_CLOSE_SESSION
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/headers_checks.rs b/third_party/rust/neqo-http3/src/headers_checks.rs
new file mode 100644
index 0000000000..9bf661c8fe
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/headers_checks.rs
@@ -0,0 +1,231 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::unused_unit)] // see https://github.com/Lymia/enumset/issues/44
+
+use std::convert::TryFrom;
+
+use enumset::{enum_set, EnumSet, EnumSetType};
+use neqo_common::Header;
+
+use crate::{Error, MessageType, Res};
+
+#[derive(EnumSetType, Debug)]
+enum PseudoHeaderState {
+    Status,
+    Method,
+    Scheme,
+    Authority,
+    Path,
+    Protocol,
+    Regular,
+}
+
+impl PseudoHeaderState {
+    fn is_pseudo(self) -> bool {
+        self != Self::Regular
+    }
+}
+
+impl TryFrom<(MessageType, &str)> for PseudoHeaderState {
+    type Error = Error;
+
+    fn try_from(v: (MessageType, &str)) -> Res<Self> {
+        match v {
+            (MessageType::Response, ":status") => Ok(Self::Status),
+            (MessageType::Request, ":method") => Ok(Self::Method),
+            (MessageType::Request, ":scheme") => Ok(Self::Scheme),
+            (MessageType::Request, ":authority") => Ok(Self::Authority),
+            (MessageType::Request, ":path") => Ok(Self::Path),
+            (MessageType::Request, ":protocol") => Ok(Self::Protocol),
+            (_, _) => Err(Error::InvalidHeader),
+        }
+    }
+}
+
+/// Check whether the response is informational(1xx).
+///
+/// # Errors
+///
+/// Returns an error if response headers do not contain
+/// a status header or if the value of the header is 101 or cannot be parsed.
+pub fn is_interim(headers: &[Header]) -> Res<bool> {
+    let status = headers.iter().take(1).find(|h| h.name() == ":status");
+    if let Some(h) = status {
+        #[allow(clippy::map_err_ignore)]
+        let status_code = h.value().parse::<i32>().map_err(|_| Error::InvalidHeader)?;
+        if status_code == 101 {
+            // https://datatracker.ietf.org/doc/html/draft-ietf-quic-http#section-4.3
+            Err(Error::InvalidHeader)
+        } else {
+            Ok((100..200).contains(&status_code))
+        }
+    } else {
+        Err(Error::InvalidHeader)
+    }
+}
+
+fn track_pseudo(
+    name: &str,
+    result_state: &mut EnumSet<PseudoHeaderState>,
+    message_type: MessageType,
+) -> Res<bool> {
+    let new_state = if name.starts_with(':') {
+        if result_state.contains(PseudoHeaderState::Regular) {
+            return Err(Error::InvalidHeader);
+        }
+        PseudoHeaderState::try_from((message_type, name))?
+    } else {
+        PseudoHeaderState::Regular
+    };
+
+    let pseudo = new_state.is_pseudo();
+    if *result_state & new_state == EnumSet::empty() || !pseudo {
+        *result_state |= new_state;
+        Ok(pseudo)
+    } else {
+        Err(Error::InvalidHeader)
+    }
+}
+
+/// Checks if request/response headers are well formed, i.e. contain
+/// allowed pseudo headers and in a right order, etc.
+///
+/// # Errors
+///
+/// Returns an error if headers are not well formed.
+pub fn headers_valid(headers: &[Header], message_type: MessageType) -> Res<()> {
+    let mut method_value: Option<&str> = None;
+    let mut protocol_value: Option<&str> = None;
+    let mut scheme_value: Option<&str> = None;
+    let mut pseudo_state = EnumSet::new();
+    for header in headers {
+        let is_pseudo = track_pseudo(header.name(), &mut pseudo_state, message_type)?;
+
+        let mut bytes = header.name().bytes();
+        if is_pseudo {
+            if header.name() == ":method" {
+                method_value = Some(header.value());
+            } else if header.name() == ":protocol" {
+                protocol_value = Some(header.value());
+            } else if header.name() == ":scheme" {
+                scheme_value = Some(header.value());
+            }
+            _ = bytes.next();
+        }
+
+        if bytes.any(|b| matches!(b, 0 | 0x10 | 0x13 | 0x3a | 0x41..=0x5a)) {
+            return Err(Error::InvalidHeader); // illegal characters.
+        }
+    }
+    // Clear the regular header bit, since we only check pseudo headers below.
+    pseudo_state.remove(PseudoHeaderState::Regular);
+    let pseudo_header_mask = match message_type {
+        MessageType::Response => enum_set!(PseudoHeaderState::Status),
+        MessageType::Request => {
+            if method_value == Some("CONNECT") {
+                let connect_mask = PseudoHeaderState::Method | PseudoHeaderState::Authority;
+                if let Some(protocol) = protocol_value {
+                    // For a webtransport CONNECT, the :scheme field must be set to https.
+                    if protocol == "webtransport" && scheme_value != Some("https") {
+                        return Err(Error::InvalidHeader);
+                    }
+                    // The CONNECT request for with :protocol included must have the scheme,
+                    // authority, and path set.
+                    connect_mask | PseudoHeaderState::Scheme | PseudoHeaderState::Path
+                } else {
+                    connect_mask
+                }
+            } else {
+                PseudoHeaderState::Method | PseudoHeaderState::Scheme | PseudoHeaderState::Path
+            }
+        }
+    };
+
+    if (MessageType::Request == message_type)
+        && pseudo_state.contains(PseudoHeaderState::Protocol)
+        && method_value != Some("CONNECT")
+    {
+        return Err(Error::InvalidHeader);
+    }
+
+    if pseudo_state & pseudo_header_mask != pseudo_header_mask {
+        return Err(Error::InvalidHeader);
+    }
+
+    Ok(())
+}
+
+/// Checks if trailers are well formed, i.e. pseudo headers are not
+/// allowed in trailers.
+///
+/// # Errors
+///
+/// Returns an error if trailers are not well formed.
+pub fn trailers_valid(headers: &[Header]) -> Res<()> {
+    for header in headers {
+        if header.name().starts_with(':') {
+            return Err(Error::InvalidHeader);
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use neqo_common::Header;
+
+    use super::headers_valid;
+    use crate::MessageType;
+
+    fn create_connect_headers() -> Vec<Header> {
+        vec![
+            Header::new(":method", "CONNECT"),
+            Header::new(":protocol", "webtransport"),
+            Header::new(":scheme", "https"),
+            Header::new(":authority", "something.com"),
+            Header::new(":path", "/here"),
+        ]
+    }
+
+    fn create_connect_headers_without_field(field: &str) -> Vec<Header> {
+        create_connect_headers()
+            .into_iter()
+            .filter(|header| header.name() != field)
+            .collect()
+    }
+
+    #[test]
+    fn connect_with_missing_header() {
+        for field in &[":scheme", ":path", ":authority"] {
+            assert!(headers_valid(
+                &create_connect_headers_without_field(field),
+                MessageType::Request
+            )
+            .is_err());
+        }
+    }
+
+    #[test]
+    fn invalid_scheme_webtransport_connect() {
+        assert!(headers_valid(
+            &[
+                Header::new(":method", "CONNECT"),
+                Header::new(":protocol", "webtransport"),
+                Header::new(":authority", "something.com"),
+                Header::new(":scheme", "http"),
+                Header::new(":path", "/here"),
+            ],
+            MessageType::Request
+        )
+        .is_err());
+    }
+
+    #[test]
+    fn valid_webtransport_connect() {
+        assert!(headers_valid(&create_connect_headers(), MessageType::Request).is_ok());
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/lib.rs b/third_party/rust/neqo-http3/src/lib.rs
new file mode 100644
index 0000000000..635707ca7c
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/lib.rs
@@ -0,0 +1,667 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![warn(clippy::pedantic)]
+
+/*!
+
+# The HTTP/3 protocol
+
+This crate implements [RFC9114](https://datatracker.ietf.org/doc/html/rfc9114).
+
+The implementation depends on:
+ - [neqo-transport](../neqo_transport/index.html) --- implements the QUIC protocol
+   ([RFC9000](https://www.rfc-editor.org/info/rfc9000)) and
+ - [neqo-qpack](../neqo_qpack/index.html) --- implements QPACK
+   ([RFC9204](https://www.rfc-editor.org/info/rfc9204));
+
+## Features
+
+Both client and server-side HTTP/3 protocols are implemented, although the server-side
+implementation is not meant to be used in production and its only purpose is to facilitate testing
+of the client-side code.
+
+__`WebTransport`__
+([draft version 2](https://datatracker.ietf.org/doc/html/draft-vvv-webtransport-http3-02)) is
+supported and can be enabled using [`Http3Parameters`](struct.Http3Parameters.html).
+
+## Interaction with an application
+
+### Driving HTTP/3  session
+
+The crate does not create an OS level UDP socket, it produces, i.e. encodes, data that should be
+sent as a payload in a UDP packet and consumes data received on the UDP socket. For example,
+[`std::net::UdpSocket`] or [`mio::net::UdpSocket`](https://crates.io/crates/mio)
+could be used for creating UDP sockets.
+
+The application is responsible for creating a socket, polling the socket, and sending and receiving
+data from the socket.
+
+In addition to receiving data HTTP/3 session’s actions may be triggered when a certain amount of
+time passes, e.g. after a certain amount of time data may be considered lost and should be
+retransmitted, packet pacing requires a timer, etc. The implementation does not use timers, but
+instead informs the application when processing needs to be triggered.
+
+
+The core functions for driving HTTP/3 sessions are:
+ - __On the client-side__ :
+   - [`process_output`](struct.Http3Client.html#method.process_output) used for producing UDP
+payload. If a payload is not produced this function returns a callback time, e.g. the time when
+[`process_output`](struct.Http3Client.html#method.process_output) should be called again.
+   - [`process_input`](struct.Http3Client.html#method.process_input)  used consuming UDP payload.
+   - [`process`](struct.Http3Client.html#method.process) combines the 2 functions into one, i.e. it
+consumes UDP payload if available and produces some UDP payload to be sent or returns a
+callback time.
+- __On the server-side__ only [`process`](struct.Http3Server.html#method.process) is
+available.
+
+An example interaction with a socket:
+
+```ignore
+let socket = match UdpSocket::bind(local_addr) {
+    Err(e) => {
+        eprintln!("Unable to bind UDP socket: {}", e);
+    }
+    Ok(s) => s,
+};
+let mut client = Http3Client::new(...);
+
+...
+
+// process_output can return 3 values, data to be sent, time duration when process_output should
+// be called, and None when Http3Client is done.
+match client.process_output(Instant::now()) {
+    Output::Datagram(dgram) => {
+        // Send dgram on a socket.
+        socket.send_to(&dgram[..], dgram.destination())
+
+    }
+    Output::Callback(duration) => {
+        // the client is idle for “duration”, set read timeout on the socket to this value and
+        // poll the socket for reading in the meantime.
+        socket.set_read_timeout(Some(duration)).unwrap();
+    }
+    Output::None => {
+        // client is done.
+    }
+};
+
+...
+
+// Reading new data coming for the network.
+match socket.recv_from(&mut buf[..]) {
+     Ok((sz, remote)) => {
+        let d = Datagram::new(remote, *local_addr, &buf[..sz]);
+        client.process_input(d, Instant::now());
+    }
+    Err(err) => {
+         eprintln!("UDP error: {}", err);
+    }
+}
+ ```
+
+### HTTP/3 session events
+
+[`Http3Client`](struct.Http3Client.html) and [`Http3Server`](struct.Http3Server.html) produce
+events that can be obtain by calling
+[`next_event`](neqo_common/event/trait.Provider.html#tymethod.next_event). The events are of type
+[`Http3ClientEvent`](enum.Http3ClientEvent.html) and
+[`Http3ServerEvent`](enum.Http3ServerEvent.html) respectively. They are informing the application
+when the connection changes state, when new data is received on a stream, etc.
+
+```ignore
+...
+
+while let Some(event) = client.next_event() {
+    match event {
+        Http3ClientEvent::DataReadable { stream_id } => {
+            println!("New data available on stream {}", stream_id);
+        }
+        Http3ClientEvent::StateChange(Http3State::Connected) => {
+            println!("Http3 session is in state Connected now");
+        }
+        _ => {
+            println!("Unhandled event {:?}", event);
+        }
+    }
+}
+```
+
+
+
+*/
+
+mod buffered_send_stream;
+mod client_events;
+mod conn_params;
+mod connection;
+mod connection_client;
+mod connection_server;
+mod control_stream_local;
+mod control_stream_remote;
+pub mod features;
+mod frames;
+mod headers_checks;
+mod priority;
+mod push_controller;
+mod qlog;
+mod qpack_decoder_receiver;
+mod qpack_encoder_receiver;
+mod recv_message;
+mod request_target;
+mod send_message;
+mod server;
+mod server_connection_events;
+mod server_events;
+mod settings;
+mod stream_type_reader;
+
+use std::{any::Any, cell::RefCell, fmt::Debug, rc::Rc};
+
+use buffered_send_stream::BufferedStream;
+pub use client_events::{Http3ClientEvent, WebTransportEvent};
+pub use conn_params::Http3Parameters;
+pub use connection::{Http3State, WebTransportSessionAcceptAction};
+pub use connection_client::Http3Client;
+use features::extended_connect::WebTransportSession;
+use frames::HFrame;
+pub use neqo_common::Header;
+use neqo_common::MessageType;
+use neqo_qpack::Error as QpackError;
+pub use neqo_transport::{streams::SendOrder, Output, StreamId};
+use neqo_transport::{
+    AppError, Connection, Error as TransportError, RecvStreamStats, SendStreamStats,
+};
+pub use priority::Priority;
+pub use server::Http3Server;
+pub use server_events::{
+    Http3OrWebTransportStream, Http3ServerEvent, WebTransportRequest, WebTransportServerEvent,
+};
+use stream_type_reader::NewStreamType;
+
+use crate::priority::PriorityHandler;
+
+type Res<T> = Result<T, Error>;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Error {
+    HttpNoError,
+    HttpGeneralProtocol,
+    HttpGeneralProtocolStream, /* this is the same as the above but it should only close a
+                                * stream not a connection. */
+    // When using this error, you need to provide a value that is unique, which
+    // will allow the specific error to be identified.  This will be validated in CI.
+    HttpInternal(u16),
+    HttpStreamCreation,
+    HttpClosedCriticalStream,
+    HttpFrameUnexpected,
+    HttpFrame,
+    HttpExcessiveLoad,
+    HttpId,
+    HttpSettings,
+    HttpMissingSettings,
+    HttpRequestRejected,
+    HttpRequestCancelled,
+    HttpRequestIncomplete,
+    HttpConnect,
+    HttpVersionFallback,
+    HttpMessageError,
+    QpackError(neqo_qpack::Error),
+
+    // Internal errors from here.
+    AlreadyClosed,
+    AlreadyInitialized,
+    DecodingFrame,
+    FatalError,
+    HttpGoaway,
+    Internal,
+    InvalidHeader,
+    InvalidInput,
+    InvalidRequestTarget,
+    InvalidResumptionToken,
+    InvalidState,
+    InvalidStreamId,
+    NoMoreData,
+    NotEnoughData,
+    StreamLimitError,
+    TransportError(TransportError),
+    TransportStreamDoesNotExist,
+    Unavailable,
+    Unexpected,
+}
+
+impl Error {
+    #[must_use]
+    pub fn code(&self) -> AppError {
+        match self {
+            Self::HttpNoError => 0x100,
+            Self::HttpGeneralProtocol | Self::HttpGeneralProtocolStream | Self::InvalidHeader => {
+                0x101
+            }
+            Self::HttpInternal(..) => 0x102,
+            Self::HttpStreamCreation => 0x103,
+            Self::HttpClosedCriticalStream => 0x104,
+            Self::HttpFrameUnexpected => 0x105,
+            Self::HttpFrame => 0x106,
+            Self::HttpExcessiveLoad => 0x107,
+            Self::HttpId => 0x108,
+            Self::HttpSettings => 0x109,
+            Self::HttpMissingSettings => 0x10a,
+            Self::HttpRequestRejected => 0x10b,
+            Self::HttpRequestCancelled => 0x10c,
+            Self::HttpRequestIncomplete => 0x10d,
+            Self::HttpMessageError => 0x10e,
+            Self::HttpConnect => 0x10f,
+            Self::HttpVersionFallback => 0x110,
+            Self::QpackError(e) => e.code(),
+            // These are all internal errors.
+            _ => 3,
+        }
+    }
+
+    #[must_use]
+    pub fn connection_error(&self) -> bool {
+        matches!(
+            self,
+            Self::HttpGeneralProtocol
+                | Self::HttpInternal(..)
+                | Self::HttpStreamCreation
+                | Self::HttpClosedCriticalStream
+                | Self::HttpFrameUnexpected
+                | Self::HttpFrame
+                | Self::HttpExcessiveLoad
+                | Self::HttpId
+                | Self::HttpSettings
+                | Self::HttpMissingSettings
+                | Self::QpackError(QpackError::EncoderStream | QpackError::DecoderStream)
+        )
+    }
+
+    #[must_use]
+    pub fn stream_reset_error(&self) -> bool {
+        matches!(self, Self::HttpGeneralProtocolStream | Self::InvalidHeader)
+    }
+
+    /// # Panics
+    ///
+    /// On unexpected errors, in debug mode.
+    #[must_use]
+    pub fn map_stream_send_errors(err: &Error) -> Self {
+        match err {
+            Self::TransportError(
+                TransportError::InvalidStreamId | TransportError::FinalSizeError,
+            ) => Error::TransportStreamDoesNotExist,
+            Self::TransportError(TransportError::InvalidInput) => Error::InvalidInput,
+            _ => {
+                debug_assert!(false, "Unexpected error");
+                Error::TransportStreamDoesNotExist
+            }
+        }
+    }
+
+    /// # Panics
+    ///
+    /// On unexpected errors, in debug mode.
+    #[must_use]
+    pub fn map_stream_create_errors(err: &TransportError) -> Self {
+        match err {
+            TransportError::ConnectionState => Error::Unavailable,
+            TransportError::StreamLimitError => Error::StreamLimitError,
+            _ => {
+                debug_assert!(false, "Unexpected error");
+                Error::TransportStreamDoesNotExist
+            }
+        }
+    }
+
+    /// # Panics
+    ///
+    /// On unexpected errors, in debug mode.
+    #[must_use]
+    pub fn map_stream_recv_errors(err: &Error) -> Self {
+        match err {
+            Self::TransportError(TransportError::NoMoreData) => {
+                debug_assert!(
+                    false,
+                    "Do not call stream_recv if FIN has been previously read"
+                );
+            }
+            Self::TransportError(TransportError::InvalidStreamId) => {}
+            _ => {
+                debug_assert!(false, "Unexpected error");
+            }
+        };
+        Error::TransportStreamDoesNotExist
+    }
+
+    #[must_use]
+    pub fn map_set_resumption_errors(err: &TransportError) -> Self {
+        match err {
+            TransportError::ConnectionState => Error::InvalidState,
+            _ => Error::InvalidResumptionToken,
+        }
+    }
+
+    /// # Errors
+    ///
+    /// Any error is mapped to the indicated type.
+    ///
+    /// # Panics
+    ///
+    /// On internal errors, in debug mode.
+    fn map_error<R>(r: Result<R, impl Into<Self>>, err: Self) -> Result<R, Self> {
+        r.map_err(|e| {
+            debug_assert!(!matches!(e.into(), Self::HttpInternal(..)));
+            debug_assert!(!matches!(err, Self::HttpInternal(..)));
+            err
+        })
+    }
+}
+
+impl From<TransportError> for Error {
+    fn from(err: TransportError) -> Self {
+        Self::TransportError(err)
+    }
+}
+
+impl From<QpackError> for Error {
+    fn from(err: QpackError) -> Self {
+        match err {
+            QpackError::ClosedCriticalStream => Error::HttpClosedCriticalStream,
+            e => Self::QpackError(e),
+        }
+    }
+}
+
+impl From<AppError> for Error {
+    fn from(error: AppError) -> Self {
+        match error {
+            0x100 => Self::HttpNoError,
+            0x101 => Self::HttpGeneralProtocol,
+            0x103 => Self::HttpStreamCreation,
+            0x104 => Self::HttpClosedCriticalStream,
+            0x105 => Self::HttpFrameUnexpected,
+            0x106 => Self::HttpFrame,
+            0x107 => Self::HttpExcessiveLoad,
+            0x108 => Self::HttpId,
+            0x109 => Self::HttpSettings,
+            0x10a => Self::HttpMissingSettings,
+            0x10b => Self::HttpRequestRejected,
+            0x10c => Self::HttpRequestCancelled,
+            0x10d => Self::HttpRequestIncomplete,
+            0x10f => Self::HttpConnect,
+            0x110 => Self::HttpVersionFallback,
+            0x200 => Self::QpackError(QpackError::DecompressionFailed),
+            0x201 => Self::QpackError(QpackError::EncoderStream),
+            0x202 => Self::QpackError(QpackError::DecoderStream),
+            _ => Self::HttpInternal(0),
+        }
+    }
+}
+
+impl ::std::error::Error for Error {
+    fn source(&self) -> Option<&(dyn ::std::error::Error + 'static)> {
+        match self {
+            Self::TransportError(e) => Some(e),
+            Self::QpackError(e) => Some(e),
+            _ => None,
+        }
+    }
+}
+
+impl ::std::fmt::Display for Error {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "HTTP/3 error: {self:?}")
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Http3StreamType {
+    Control,
+    Decoder,
+    Encoder,
+    NewStream,
+    Http,
+    Push,
+    ExtendedConnect,
+    WebTransport(StreamId),
+    Unknown,
+}
+
+#[must_use]
+#[derive(PartialEq, Eq, Debug)]
+enum ReceiveOutput {
+    NoOutput,
+    ControlFrames(Vec<HFrame>),
+    UnblockedStreams(Vec<StreamId>),
+    NewStream(NewStreamType),
+}
+
+impl Default for ReceiveOutput {
+    fn default() -> Self {
+        Self::NoOutput
+    }
+}
+
+trait Stream: Debug {
+    fn stream_type(&self) -> Http3StreamType;
+}
+
+trait RecvStream: Stream {
+    /// The stream reads data from the corresponding quic stream and returns `ReceiveOutput`.
+    /// The function also returns true as the second parameter if the stream is done and
+    /// could be forgotten, i.e. removed from all records.
+    ///
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)>;
+
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, etc.
+    fn reset(&mut self, close_type: CloseType) -> Res<()>;
+
+    /// The function allows an app to read directly from the quic stream. The function
+    /// returns the number of bytes written into `buf` and true/false if the stream is
+    /// completely done and can be forgotten, i.e. removed from all records.
+    ///
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    fn read_data(&mut self, _conn: &mut Connection, _buf: &mut [u8]) -> Res<(usize, bool)> {
+        Err(Error::InvalidStreamId)
+    }
+
+    fn http_stream(&mut self) -> Option<&mut dyn HttpRecvStream> {
+        None
+    }
+
+    fn webtransport(&self) -> Option<Rc<RefCell<WebTransportSession>>> {
+        None
+    }
+
+    /// This function is only implemented by `WebTransportRecvStream`.
+    fn stats(&mut self, _conn: &mut Connection) -> Res<RecvStreamStats> {
+        Err(Error::Unavailable)
+    }
+}
+
+trait HttpRecvStream: RecvStream {
+    /// This function is similar to the receive function and has the same output, i.e.
+    /// a `ReceiveOutput` enum and bool. The bool is true if the stream is completely done
+    /// and can be forgotten, i.e. removed from all records.
+    ///
+    /// # Errors
+    ///
+    /// An error may happen while reading a stream, e.g. early close, protocol error, etc.
+    fn header_unblocked(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)>;
+
+    fn maybe_update_priority(&mut self, priority: Priority) -> bool;
+    fn priority_update_frame(&mut self) -> Option<HFrame>;
+    fn priority_update_sent(&mut self);
+
+    fn set_new_listener(&mut self, _conn_events: Box<dyn HttpRecvStreamEvents>) {}
+    fn extended_connect_wait_for_response(&self) -> bool {
+        false
+    }
+
+    fn any(&self) -> &dyn Any;
+}
+
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+pub struct Http3StreamInfo {
+    stream_id: StreamId,
+    stream_type: Http3StreamType,
+}
+
+impl Http3StreamInfo {
+    #[must_use]
+    pub fn new(stream_id: StreamId, stream_type: Http3StreamType) -> Self {
+        Self {
+            stream_id,
+            stream_type,
+        }
+    }
+
+    #[must_use]
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    #[must_use]
+    pub fn session_id(&self) -> Option<StreamId> {
+        if let Http3StreamType::WebTransport(session) = self.stream_type {
+            Some(session)
+        } else {
+            None
+        }
+    }
+
+    #[must_use]
+    pub fn is_http(&self) -> bool {
+        self.stream_type == Http3StreamType::Http
+    }
+}
+
+trait RecvStreamEvents: Debug {
+    fn data_readable(&self, _stream_info: Http3StreamInfo) {}
+    fn recv_closed(&self, _stream_info: Http3StreamInfo, _close_type: CloseType) {}
+}
+
+trait HttpRecvStreamEvents: RecvStreamEvents {
+    fn header_ready(
+        &self,
+        stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    );
+    fn extended_connect_new_session(&self, _stream_id: StreamId, _headers: Vec<Header>) {}
+}
+
+trait SendStream: Stream {
+    /// # Errors
+    ///
+    /// Error my occur during sending data, e.g. protocol error, etc.
+    fn send(&mut self, conn: &mut Connection) -> Res<()>;
+    fn has_data_to_send(&self) -> bool;
+    fn stream_writable(&self);
+    fn done(&self) -> bool;
+    fn set_sendorder(&mut self, conn: &mut Connection, sendorder: Option<SendOrder>) -> Res<()>;
+    fn set_fairness(&mut self, conn: &mut Connection, fairness: bool) -> Res<()>;
+
+    /// # Errors
+    ///
+    /// Error my occur during sending data, e.g. protocol error, etc.
+    fn send_data(&mut self, _conn: &mut Connection, _buf: &[u8]) -> Res<usize>;
+
+    /// # Errors
+    ///
+    /// It may happen that the transport stream is already close. This is unlikely.
+    fn close(&mut self, conn: &mut Connection) -> Res<()>;
+
+    /// # Errors
+    ///
+    /// It may happen that the transport stream is already close. This is unlikely.
+    fn close_with_message(
+        &mut self,
+        _conn: &mut Connection,
+        _error: u32,
+        _message: &str,
+    ) -> Res<()> {
+        Err(Error::InvalidStreamId)
+    }
+
+    /// This function is called when sending side is closed abruptly by the peer or
+    /// the application.
+    fn handle_stop_sending(&mut self, close_type: CloseType);
+    fn http_stream(&mut self) -> Option<&mut dyn HttpSendStream> {
+        None
+    }
+
+    /// # Errors
+    ///
+    /// It may happen that the transport stream is already close. This is unlikely.
+    fn send_data_atomic(&mut self, _conn: &mut Connection, _buf: &[u8]) -> Res<()> {
+        Err(Error::InvalidStreamId)
+    }
+
+    /// This function is only implemented by `WebTransportSendStream`.
+    fn stats(&mut self, _conn: &mut Connection) -> Res<SendStreamStats> {
+        Err(Error::Unavailable)
+    }
+}
+
+trait HttpSendStream: SendStream {
+    /// This function is used to supply headers to a http message. The
+    /// function is used for request headers, response headers, 1xx response and
+    /// trailers.
+    ///
+    /// # Errors
+    ///
+    /// This can also return an error if the underlying stream is closed.
+    fn send_headers(&mut self, headers: &[Header], conn: &mut Connection) -> Res<()>;
+    fn set_new_listener(&mut self, _conn_events: Box<dyn SendStreamEvents>) {}
+    fn any(&self) -> &dyn Any;
+}
+
+trait SendStreamEvents: Debug {
+    fn send_closed(&self, _stream_info: Http3StreamInfo, _close_type: CloseType) {}
+    fn data_writable(&self, _stream_info: Http3StreamInfo) {}
+}
+
+/// This enum is used to mark a different type of closing a stream:
+///   `ResetApp` - the application has closed the stream.
+///   `ResetRemote` - the stream was closed by the peer.
+///   `LocalError` - There was a stream error on the stream. The stream errors are errors
+///                  that do not close the complete connection, e.g. unallowed headers.
+///   `Done` - the stream was closed without an error.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum CloseType {
+    ResetApp(AppError),
+    ResetRemote(AppError),
+    LocalError(AppError),
+    Done,
+}
+
+impl CloseType {
+    #[must_use]
+    pub fn error(&self) -> Option<AppError> {
+        match self {
+            Self::ResetApp(error) | Self::ResetRemote(error) | Self::LocalError(error) => {
+                Some(*error)
+            }
+            Self::Done => None,
+        }
+    }
+
+    #[must_use]
+    pub fn locally_initiated(&self) -> bool {
+        matches!(self, CloseType::ResetApp(_))
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/priority.rs b/third_party/rust/neqo-http3/src/priority.rs
new file mode 100644
index 0000000000..f2651d3bb5
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/priority.rs
@@ -0,0 +1,212 @@
+use std::{convert::TryFrom, fmt};
+
+use neqo_transport::StreamId;
+use sfv::{BareItem, Item, ListEntry, Parser};
+
+use crate::{frames::HFrame, Error, Header, Res};
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct Priority {
+    urgency: u8,
+    incremental: bool,
+}
+
+impl Default for Priority {
+    fn default() -> Self {
+        Priority {
+            urgency: 3,
+            incremental: false,
+        }
+    }
+}
+
+impl Priority {
+    /// # Panics
+    ///
+    /// If an invalid urgency (>7 is given)
+    #[must_use]
+    pub fn new(urgency: u8, incremental: bool) -> Priority {
+        assert!(urgency < 8);
+        Priority {
+            urgency,
+            incremental,
+        }
+    }
+
+    /// Returns a header if required to send
+    #[must_use]
+    pub fn header(self) -> Option<Header> {
+        match self {
+            Priority {
+                urgency: 3,
+                incremental: false,
+            } => None,
+            other => Some(Header::new("priority", format!("{other}"))),
+        }
+    }
+
+    /// Constructs a priority from raw bytes (either a field value of frame content).
+    ///
+    /// # Errors
+    ///
+    /// When the contained syntax is invalid.
+    ///
+    /// # Panics
+    ///
+    /// Never, but the compiler is not smart enough to work that out.
+    pub fn from_bytes(bytes: &[u8]) -> Res<Priority> {
+        let dict = Parser::parse_dictionary(bytes).map_err(|_| Error::HttpFrame)?;
+        let urgency = match dict.get("u") {
+            Some(ListEntry::Item(Item {
+                bare_item: BareItem::Integer(u),
+                ..
+            })) if (0..=7).contains(u) => u8::try_from(*u).unwrap(),
+            _ => 3,
+        };
+        let incremental = match dict.get("i") {
+            Some(ListEntry::Item(Item {
+                bare_item: BareItem::Boolean(i),
+                ..
+            })) => *i,
+            _ => false,
+        };
+        Ok(Priority {
+            urgency,
+            incremental,
+        })
+    }
+}
+
+impl fmt::Display for Priority {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Priority {
+                urgency: 3,
+                incremental: false,
+            } => Ok(()),
+            Priority {
+                urgency: 3,
+                incremental: true,
+            } => write!(f, "i"),
+            Priority {
+                urgency,
+                incremental: false,
+            } => write!(f, "u={urgency}"),
+            Priority {
+                urgency,
+                incremental: true,
+            } => write!(f, "u={urgency},i"),
+        }
+    }
+}
+
+#[derive(Debug)]
+#[allow(clippy::module_name_repetitions)]
+pub struct PriorityHandler {
+    push_stream: bool,
+    priority: Priority,
+    last_send_priority: Priority,
+}
+
+impl PriorityHandler {
+    pub fn new(push_stream: bool, priority: Priority) -> PriorityHandler {
+        PriorityHandler {
+            push_stream,
+            priority,
+            last_send_priority: priority,
+        }
+    }
+
+    /*pub fn priority(&self) -> Priority {
+        self.priority
+    }*/
+
+    /// Returns if an priority update will be issued
+    pub fn maybe_update_priority(&mut self, priority: Priority) -> bool {
+        if priority == self.priority {
+            false
+        } else {
+            self.priority = priority;
+            true
+        }
+    }
+
+    pub fn priority_update_sent(&mut self) {
+        self.last_send_priority = self.priority;
+    }
+
+    /// Returns `HFrame` if an priority update is outstanding
+    pub fn maybe_encode_frame(&self, stream_id: StreamId) -> Option<HFrame> {
+        if self.priority == self.last_send_priority {
+            None
+        } else if self.push_stream {
+            Some(HFrame::PriorityUpdatePush {
+                element_id: stream_id.as_u64(),
+                priority: self.priority,
+            })
+        } else {
+            Some(HFrame::PriorityUpdateRequest {
+                element_id: stream_id.as_u64(),
+                priority: self.priority,
+            })
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use neqo_transport::StreamId;
+
+    use crate::{priority::PriorityHandler, HFrame, Priority};
+
+    #[test]
+    fn priority_updates_ignore_same() {
+        let mut p = PriorityHandler::new(false, Priority::new(5, false));
+        assert!(!p.maybe_update_priority(Priority::new(5, false)));
+        // updating with the same priority -> there should not be any priority frame sent
+        assert!(p.maybe_encode_frame(StreamId::new(4)).is_none());
+    }
+
+    #[test]
+    fn priority_updates_send_update() {
+        let mut p = PriorityHandler::new(false, Priority::new(5, false));
+        assert!(p.maybe_update_priority(Priority::new(6, false)));
+        // updating with the a different priority -> there should be a priority frame sent
+        assert!(p.maybe_encode_frame(StreamId::new(4)).is_some());
+    }
+
+    #[test]
+    fn multiple_priority_updates_ignore_same() {
+        let mut p = PriorityHandler::new(false, Priority::new(5, false));
+        assert!(p.maybe_update_priority(Priority::new(6, false)));
+        assert!(p.maybe_update_priority(Priority::new(5, false)));
+        // initial and last priority same -> there should not be any priority frame sent
+        assert!(p.maybe_encode_frame(StreamId::new(4)).is_none());
+    }
+
+    #[test]
+    fn multiple_priority_updates_send_update() {
+        let mut p = PriorityHandler::new(false, Priority::new(5, false));
+        assert!(p.maybe_update_priority(Priority::new(6, false)));
+        assert!(p.maybe_update_priority(Priority::new(7, false)));
+        // updating two times with a different priority -> the last priority update should be in the
+        // next frame
+        let expected = HFrame::PriorityUpdateRequest {
+            element_id: 4,
+            priority: Priority::new(7, false),
+        };
+        assert_eq!(p.maybe_encode_frame(StreamId::new(4)), Some(expected));
+    }
+
+    #[test]
+    fn priority_updates_incremental() {
+        let mut p = PriorityHandler::new(false, Priority::new(5, false));
+        assert!(p.maybe_update_priority(Priority::new(5, true)));
+        // updating the incremental parameter -> there should be a priority frame sent
+        let expected = HFrame::PriorityUpdateRequest {
+            element_id: 4,
+            priority: Priority::new(5, true),
+        };
+        assert_eq!(p.maybe_encode_frame(StreamId::new(4)), Some(expected));
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/push_controller.rs b/third_party/rust/neqo-http3/src/push_controller.rs
new file mode 100644
index 0000000000..c4591991ae
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/push_controller.rs
@@ -0,0 +1,516 @@
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{
+    cell::RefCell,
+    collections::VecDeque,
+    convert::TryFrom,
+    fmt::{Debug, Display},
+    mem,
+    rc::Rc,
+    slice::SliceIndex,
+};
+
+use neqo_common::{qerror, qinfo, qtrace, Header};
+use neqo_transport::{Connection, StreamId};
+
+use crate::{
+    client_events::{Http3ClientEvent, Http3ClientEvents},
+    connection::Http3Connection,
+    frames::HFrame,
+    CloseType, Error, Http3StreamInfo, HttpRecvStreamEvents, RecvStreamEvents, Res,
+};
+
+/// `PushStates`:
+///   `Init`: there is no push stream nor a push promise. This state is only used to keep track of
+/// opened and closed           push streams.
+///   `PushPromise`: the push has only ever receive a pushpromise frame
+///   `OnlyPushStream`: there is only a push stream. All push stream events, i.e. `PushHeaderReady`
+/// and                     `PushDataReadable` will be delayed until a push promise is received
+/// (they are kept in                     `events`).
+///   `Active`: there is a push steam and at least one push promise frame.
+///   `Close`: the push stream has been closed or reset already.
+#[derive(Debug, PartialEq, Clone)]
+enum PushState {
+    Init,
+    PushPromise {
+        headers: Vec<Header>,
+    },
+    OnlyPushStream {
+        stream_id: StreamId,
+        events: Vec<Http3ClientEvent>,
+    },
+    Active {
+        stream_id: StreamId,
+        headers: Vec<Header>,
+    },
+    Closed,
+}
+
+/// `ActivePushStreams` holds information about push streams.
+///
+/// `first_push_id` holds a `push_id` of the first element in `push_streams` if it is present.
+/// `push_id` smaller than `first_push_id` have been already closed. `push_id` => `first_push_id`
+/// are in `push_streams` or they are not yet opened.
+#[derive(Debug)]
+struct ActivePushStreams {
+    push_streams: VecDeque<PushState>,
+    first_push_id: u64,
+}
+
+impl ActivePushStreams {
+    pub fn new() -> Self {
+        Self {
+            push_streams: VecDeque::new(),
+            first_push_id: 0,
+        }
+    }
+
+    /// Returns None if a stream has been closed already.
+    pub fn get_mut(
+        &mut self,
+        push_id: u64,
+    ) -> Option<&mut <usize as SliceIndex<[PushState]>>::Output> {
+        if push_id < self.first_push_id {
+            return None;
+        }
+
+        let inx = usize::try_from(push_id - self.first_push_id).unwrap();
+        if inx >= self.push_streams.len() {
+            self.push_streams.resize(inx + 1, PushState::Init);
+        }
+        match self.push_streams.get_mut(inx) {
+            Some(PushState::Closed) => None,
+            e => e,
+        }
+    }
+
+    /// Returns None if a stream has been closed already.
+    pub fn get(&mut self, push_id: u64) -> Option<&mut PushState> {
+        self.get_mut(push_id)
+    }
+
+    /// Returns the State of a closed push stream or None for already closed streams.
+    pub fn close(&mut self, push_id: u64) -> Option<PushState> {
+        match self.get_mut(push_id) {
+            None | Some(PushState::Closed) => None,
+            Some(s) => {
+                let res = mem::replace(s, PushState::Closed);
+                while let Some(PushState::Closed) = self.push_streams.front() {
+                    self.push_streams.pop_front();
+                    self.first_push_id += 1;
+                }
+                Some(res)
+            }
+        }
+    }
+
+    #[must_use]
+    pub fn number_done(&self) -> u64 {
+        self.first_push_id
+            + u64::try_from(
+                self.push_streams
+                    .iter()
+                    .filter(|&e| e == &PushState::Closed)
+                    .count(),
+            )
+            .unwrap()
+    }
+
+    pub fn clear(&mut self) {
+        self.first_push_id = 0;
+        self.push_streams.clear();
+    }
+}
+
+/// `PushController` keeps information about push stream states.
+///
+/// A `PushStream` calls `add_new_push_stream` that may change the push state from Init to
+/// `OnlyPushStream` or from `PushPromise` to `Active`. If a stream has already been closed
+/// `add_new_push_stream` returns false (the `PushStream` will close the transport stream).
+/// A `PushStream` calls `push_stream_reset` if the transport stream has been canceled.
+/// When a push stream is done it calls `close`.
+///
+/// The `PushController` handles:
+///  `PUSH_PROMISE` frame: frames may change the push state from Init to `PushPromise` and from
+/// `OnlyPushStream` to                        `Active`. Frames for a closed steams are ignored.
+///  `CANCEL_PUSH` frame: (`handle_cancel_push` will be called). If a push is in state `PushPromise`
+/// or `Active`, any                       posted events will be removed and a `PushCanceled` event
+/// will be posted. If a push is in                       state `OnlyPushStream` or `Active` the
+/// transport stream and the `PushStream` will be closed.                       The frame will be
+/// ignored for already closed pushes.  Application calling cancel: the actions are similar to the
+/// `CANCEL_PUSH` frame. The difference is that                              `PushCanceled` will not
+/// be posted and a `CANCEL_PUSH` frame may be sent.
+#[derive(Debug)]
+pub(crate) struct PushController {
+    max_concurent_push: u64,
+    current_max_push_id: u64,
+    // push_streams holds the states of push streams.
+    // We keep a stream until the stream has been closed.
+    push_streams: ActivePushStreams,
+    // The keeps the next consecutive push_id that should be open.
+    // All push_id < next_push_id_to_open are in the push_stream lists. If they are not in the list
+    // they have been already closed.
+    conn_events: Http3ClientEvents,
+}
+
+impl PushController {
+    pub fn new(max_concurent_push: u64, conn_events: Http3ClientEvents) -> Self {
+        PushController {
+            max_concurent_push,
+            current_max_push_id: 0,
+            push_streams: ActivePushStreams::new(),
+            conn_events,
+        }
+    }
+}
+
+impl Display for PushController {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Push controler")
+    }
+}
+
+impl PushController {
+    /// A new `push_promise` has been received.
+    ///
+    /// # Errors
+    ///
+    /// `HttpId` if `push_id` greater than it is allowed has been received.
+    pub fn new_push_promise(
+        &mut self,
+        push_id: u64,
+        ref_stream_id: StreamId,
+        new_headers: Vec<Header>,
+    ) -> Res<()> {
+        qtrace!(
+            [self],
+            "New push promise push_id={} headers={:?} max_push={}",
+            push_id,
+            new_headers,
+            self.max_concurent_push
+        );
+
+        self.check_push_id(push_id)?;
+
+        match self.push_streams.get_mut(push_id) {
+            None => {
+                qtrace!("Push has been closed already {}.", push_id);
+                Ok(())
+            }
+            Some(push_state) => match push_state {
+                PushState::Init => {
+                    self.conn_events
+                        .push_promise(push_id, ref_stream_id, new_headers.clone());
+                    *push_state = PushState::PushPromise {
+                        headers: new_headers,
+                    };
+                    Ok(())
+                }
+                PushState::PushPromise { headers } | PushState::Active { headers, .. } => {
+                    if new_headers != *headers {
+                        return Err(Error::HttpGeneralProtocol);
+                    }
+                    self.conn_events
+                        .push_promise(push_id, ref_stream_id, new_headers);
+                    Ok(())
+                }
+                PushState::OnlyPushStream { stream_id, events } => {
+                    let stream_id_tmp = *stream_id;
+                    self.conn_events
+                        .push_promise(push_id, ref_stream_id, new_headers.clone());
+
+                    for e in events.drain(..) {
+                        self.conn_events.insert(e);
+                    }
+                    *push_state = PushState::Active {
+                        stream_id: stream_id_tmp,
+                        headers: new_headers,
+                    };
+                    Ok(())
+                }
+                PushState::Closed => unreachable!("This is only internal; it is transfer to None"),
+            },
+        }
+    }
+
+    pub fn add_new_push_stream(&mut self, push_id: u64, stream_id: StreamId) -> Res<bool> {
+        qtrace!(
+            "A new push stream with push_id={} stream_id={}",
+            push_id,
+            stream_id
+        );
+
+        self.check_push_id(push_id)?;
+
+        match self.push_streams.get_mut(push_id) {
+            None => {
+                qinfo!("Push has been closed already.");
+                Ok(false)
+            }
+            Some(push_state) => match push_state {
+                PushState::Init => {
+                    *push_state = PushState::OnlyPushStream {
+                        stream_id,
+                        events: Vec::new(),
+                    };
+                    Ok(true)
+                }
+                PushState::PushPromise { headers } => {
+                    let tmp = mem::take(headers);
+                    *push_state = PushState::Active {
+                        stream_id,
+                        headers: tmp,
+                    };
+                    Ok(true)
+                }
+                // The following state have already have a push stream:
+                // PushState::OnlyPushStream | PushState::Active
+                _ => {
+                    qerror!("Duplicate push stream.");
+                    Err(Error::HttpId)
+                }
+            },
+        }
+    }
+
+    fn check_push_id(&mut self, push_id: u64) -> Res<()> {
+        // Check if push id is greater than what we allow.
+        if push_id > self.current_max_push_id {
+            qerror!("Push id is greater than current_max_push_id.");
+            Err(Error::HttpId)
+        } else {
+            Ok(())
+        }
+    }
+
+    pub fn handle_cancel_push(
+        &mut self,
+        push_id: u64,
+        conn: &mut Connection,
+        base_handler: &mut Http3Connection,
+    ) -> Res<()> {
+        qtrace!("CANCEL_PUSH frame has been received, push_id={}", push_id);
+
+        self.check_push_id(push_id)?;
+
+        match self.push_streams.close(push_id) {
+            None => {
+                qtrace!("Push has already been closed (push_id={}).", push_id);
+                Ok(())
+            }
+            Some(ps) => match ps {
+                PushState::Init => Ok(()),
+                PushState::PushPromise { .. } => {
+                    self.conn_events.remove_events_for_push_id(push_id);
+                    self.conn_events.push_canceled(push_id);
+                    Ok(())
+                }
+                PushState::OnlyPushStream { stream_id, .. }
+                | PushState::Active { stream_id, .. } => {
+                    mem::drop(base_handler.stream_stop_sending(
+                        conn,
+                        stream_id,
+                        Error::HttpRequestCancelled.code(),
+                    ));
+                    self.conn_events.remove_events_for_push_id(push_id);
+                    self.conn_events.push_canceled(push_id);
+                    Ok(())
+                }
+                PushState::Closed => unreachable!("This is only internal; it is transfer to None"),
+            },
+        }
+    }
+
+    pub fn close(&mut self, push_id: u64) {
+        qtrace!("Push stream has been closed.");
+        if let Some(push_state) = self.push_streams.close(push_id) {
+            debug_assert!(matches!(push_state, PushState::Active { .. }));
+        } else {
+            debug_assert!(false, "Closing non existing push stream!");
+        }
+    }
+
+    pub fn cancel(
+        &mut self,
+        push_id: u64,
+        conn: &mut Connection,
+        base_handler: &mut Http3Connection,
+    ) -> Res<()> {
+        qtrace!("Cancel push_id={}", push_id);
+
+        self.check_push_id(push_id)?;
+
+        match self.push_streams.get(push_id) {
+            None => {
+                qtrace!("Push has already been closed.");
+                // If we have some events for the push_id in the event queue, the caller still does
+                // not not know that the push has been closed. Otherwise return
+                // InvalidStreamId.
+                if self.conn_events.has_push(push_id) {
+                    self.conn_events.remove_events_for_push_id(push_id);
+                    Ok(())
+                } else {
+                    Err(Error::InvalidStreamId)
+                }
+            }
+            Some(PushState::PushPromise { .. }) => {
+                self.conn_events.remove_events_for_push_id(push_id);
+                base_handler.queue_control_frame(&HFrame::CancelPush { push_id });
+                self.push_streams.close(push_id);
+                Ok(())
+            }
+            Some(PushState::Active { stream_id, .. }) => {
+                self.conn_events.remove_events_for_push_id(push_id);
+                // Cancel the stream. the transport steam may already be done, so ignore an error.
+                mem::drop(base_handler.stream_stop_sending(
+                    conn,
+                    *stream_id,
+                    Error::HttpRequestCancelled.code(),
+                ));
+                self.push_streams.close(push_id);
+                Ok(())
+            }
+            Some(_) => Err(Error::InvalidStreamId),
+        }
+    }
+
+    pub fn push_stream_reset(&mut self, push_id: u64, close_type: CloseType) {
+        qtrace!("Push stream has been reset, push_id={}", push_id);
+
+        if let Some(push_state) = self.push_streams.get(push_id) {
+            match push_state {
+                PushState::OnlyPushStream { .. } => {
+                    self.push_streams.close(push_id);
+                }
+                PushState::Active { .. } => {
+                    self.push_streams.close(push_id);
+                    self.conn_events.remove_events_for_push_id(push_id);
+                    if let CloseType::LocalError(app_error) = close_type {
+                        self.conn_events.push_reset(push_id, app_error);
+                    } else {
+                        self.conn_events.push_canceled(push_id);
+                    }
+                }
+                _ => {
+                    debug_assert!(
+                        false,
+                        "Reset cannot actually happen because we do not have a stream."
+                    );
+                }
+            }
+        }
+    }
+
+    pub fn get_active_stream_id(&mut self, push_id: u64) -> Option<StreamId> {
+        match self.push_streams.get(push_id) {
+            Some(PushState::Active { stream_id, .. }) => Some(*stream_id),
+            _ => None,
+        }
+    }
+
+    pub fn maybe_send_max_push_id_frame(&mut self, base_handler: &mut Http3Connection) {
+        let push_done = self.push_streams.number_done();
+        if self.max_concurent_push > 0
+            && (self.current_max_push_id - push_done) <= (self.max_concurent_push / 2)
+        {
+            self.current_max_push_id = push_done + self.max_concurent_push;
+            base_handler.queue_control_frame(&HFrame::MaxPushId {
+                push_id: self.current_max_push_id,
+            });
+        }
+    }
+
+    pub fn handle_zero_rtt_rejected(&mut self) {
+        self.current_max_push_id = 0;
+    }
+
+    pub fn clear(&mut self) {
+        self.push_streams.clear();
+    }
+
+    pub fn can_receive_push(&self) -> bool {
+        self.max_concurent_push > 0
+    }
+
+    pub fn new_stream_event(&mut self, push_id: u64, event: Http3ClientEvent) {
+        match self.push_streams.get_mut(push_id) {
+            None => {
+                debug_assert!(false, "Push has been closed already.");
+            }
+            Some(PushState::OnlyPushStream { events, .. }) => {
+                events.push(event);
+            }
+            Some(PushState::Active { .. }) => {
+                self.conn_events.insert(event);
+            }
+            Some(_) => {
+                debug_assert!(false, "No record of a stream!");
+            }
+        }
+    }
+}
+
+/// `RecvPushEvents` relays a push stream events to `PushController`.
+/// It informs `PushController` when a push stream is done or canceled.
+/// Also when headers or data is ready and `PushController` decide whether to post
+/// `PushHeaderReady` and `PushDataReadable` events or to postpone them if
+/// a `push_promise` has not been yet received for the stream.
+#[derive(Debug)]
+pub(crate) struct RecvPushEvents {
+    push_id: u64,
+    push_handler: Rc<RefCell<PushController>>,
+}
+
+impl RecvPushEvents {
+    pub fn new(push_id: u64, push_handler: Rc<RefCell<PushController>>) -> Self {
+        Self {
+            push_id,
+            push_handler,
+        }
+    }
+}
+
+impl RecvStreamEvents for RecvPushEvents {
+    fn data_readable(&self, _stream_info: Http3StreamInfo) {
+        self.push_handler.borrow_mut().new_stream_event(
+            self.push_id,
+            Http3ClientEvent::PushDataReadable {
+                push_id: self.push_id,
+            },
+        );
+    }
+
+    fn recv_closed(&self, _stream_info: Http3StreamInfo, close_type: CloseType) {
+        match close_type {
+            CloseType::ResetApp(_) => {}
+            CloseType::ResetRemote(_) | CloseType::LocalError(_) => self
+                .push_handler
+                .borrow_mut()
+                .push_stream_reset(self.push_id, close_type),
+            CloseType::Done => self.push_handler.borrow_mut().close(self.push_id),
+        }
+    }
+}
+
+impl HttpRecvStreamEvents for RecvPushEvents {
+    fn header_ready(
+        &self,
+        _stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        interim: bool,
+        fin: bool,
+    ) {
+        self.push_handler.borrow_mut().new_stream_event(
+            self.push_id,
+            Http3ClientEvent::PushHeaderReady {
+                push_id: self.push_id,
+                headers,
+                interim,
+                fin,
+            },
+        );
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/qlog.rs b/third_party/rust/neqo-http3/src/qlog.rs
new file mode 100644
index 0000000000..c3a13fd19f
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/qlog.rs
@@ -0,0 +1,46 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Functions that handle capturing QLOG traces.
+
+use std::convert::TryFrom;
+
+use neqo_common::qlog::NeqoQlog;
+use neqo_transport::StreamId;
+use qlog::{
+    self,
+    events::{DataRecipient, EventData},
+};
+
+pub fn h3_data_moved_up(qlog: &mut NeqoQlog, stream_id: StreamId, amount: usize) {
+    qlog.add_event_data(|| {
+        let ev_data = EventData::DataMoved(qlog::events::quic::DataMoved {
+            stream_id: Some(stream_id.as_u64()),
+            offset: None,
+            length: Some(u64::try_from(amount).unwrap()),
+            from: Some(DataRecipient::Transport),
+            to: Some(DataRecipient::Application),
+            raw: None,
+        });
+
+        Some(ev_data)
+    });
+}
+
+pub fn h3_data_moved_down(qlog: &mut NeqoQlog, stream_id: StreamId, amount: usize) {
+    qlog.add_event_data(|| {
+        let ev_data = EventData::DataMoved(qlog::events::quic::DataMoved {
+            stream_id: Some(stream_id.as_u64()),
+            offset: None,
+            length: Some(u64::try_from(amount).unwrap()),
+            from: Some(DataRecipient::Application),
+            to: Some(DataRecipient::Transport),
+            raw: None,
+        });
+
+        Some(ev_data)
+    });
+}
diff --git a/third_party/rust/neqo-http3/src/qpack_decoder_receiver.rs b/third_party/rust/neqo-http3/src/qpack_decoder_receiver.rs
new file mode 100644
index 0000000000..46b9ca590b
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/qpack_decoder_receiver.rs
@@ -0,0 +1,45 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{cell::RefCell, rc::Rc};
+
+use neqo_qpack::QPackDecoder;
+use neqo_transport::{Connection, StreamId};
+
+use crate::{CloseType, Error, Http3StreamType, ReceiveOutput, RecvStream, Res, Stream};
+
+#[derive(Debug)]
+pub(crate) struct DecoderRecvStream {
+    stream_id: StreamId,
+    decoder: Rc<RefCell<QPackDecoder>>,
+}
+
+impl DecoderRecvStream {
+    pub fn new(stream_id: StreamId, decoder: Rc<RefCell<QPackDecoder>>) -> Self {
+        Self { stream_id, decoder }
+    }
+}
+
+impl Stream for DecoderRecvStream {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::Decoder
+    }
+}
+
+impl RecvStream for DecoderRecvStream {
+    fn reset(&mut self, _close_type: CloseType) -> Res<()> {
+        Err(Error::HttpClosedCriticalStream)
+    }
+
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        Ok((
+            ReceiveOutput::UnblockedStreams(
+                self.decoder.borrow_mut().receive(conn, self.stream_id)?,
+            ),
+            false,
+        ))
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/qpack_encoder_receiver.rs b/third_party/rust/neqo-http3/src/qpack_encoder_receiver.rs
new file mode 100644
index 0000000000..76c779bcf2
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/qpack_encoder_receiver.rs
@@ -0,0 +1,41 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{cell::RefCell, rc::Rc};
+
+use neqo_qpack::QPackEncoder;
+use neqo_transport::{Connection, StreamId};
+
+use crate::{CloseType, Error, Http3StreamType, ReceiveOutput, RecvStream, Res, Stream};
+
+#[derive(Debug)]
+pub(crate) struct EncoderRecvStream {
+    stream_id: StreamId,
+    encoder: Rc<RefCell<QPackEncoder>>,
+}
+
+impl EncoderRecvStream {
+    pub fn new(stream_id: StreamId, encoder: Rc<RefCell<QPackEncoder>>) -> Self {
+        Self { stream_id, encoder }
+    }
+}
+
+impl Stream for EncoderRecvStream {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::Encoder
+    }
+}
+
+impl RecvStream for EncoderRecvStream {
+    fn reset(&mut self, _close_type: CloseType) -> Res<()> {
+        Err(Error::HttpClosedCriticalStream)
+    }
+
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        self.encoder.borrow_mut().receive(conn, self.stream_id)?;
+        Ok((ReceiveOutput::NoOutput, false))
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/recv_message.rs b/third_party/rust/neqo-http3/src/recv_message.rs
new file mode 100644
index 0000000000..36e8f65b19
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/recv_message.rs
@@ -0,0 +1,501 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{
+    any::Any, cell::RefCell, cmp::min, collections::VecDeque, convert::TryFrom, fmt::Debug, rc::Rc,
+};
+
+use neqo_common::{qdebug, qinfo, qtrace, Header};
+use neqo_qpack::decoder::QPackDecoder;
+use neqo_transport::{Connection, StreamId};
+
+use crate::{
+    frames::{FrameReader, HFrame, StreamReaderConnectionWrapper, H3_FRAME_TYPE_HEADERS},
+    headers_checks::{headers_valid, is_interim},
+    priority::PriorityHandler,
+    push_controller::PushController,
+    qlog, CloseType, Error, Http3StreamInfo, Http3StreamType, HttpRecvStream, HttpRecvStreamEvents,
+    MessageType, Priority, ReceiveOutput, RecvStream, Res, Stream,
+};
+
+#[allow(clippy::module_name_repetitions)]
+pub(crate) struct RecvMessageInfo {
+    pub message_type: MessageType,
+    pub stream_type: Http3StreamType,
+    pub stream_id: StreamId,
+    pub header_frame_type_read: bool,
+}
+
+/*
+ * Response stream state:
+ *    WaitingForResponseHeaders : we wait for headers. in this state we can
+ *                                also get a PUSH_PROMISE frame.
+ *    DecodingHeaders : In this step the headers will be decoded. The stream
+ *                      may be blocked in this state on encoder instructions.
+ *    WaitingForData : we got HEADERS, we are waiting for one or more data
+ *                     frames. In this state we can receive one or more
+ *                     PUSH_PROMIS frames or a HEADERS frame carrying trailers.
+ *    ReadingData : we got a DATA frame, now we letting the app read payload.
+ *                  From here we will go back to WaitingForData state to wait
+ *                  for more data frames or to CLosed state
+ *    ClosePending : waiting for app to pick up data, after that we can delete
+ * the TransactionClient.
+ *    Closed
+ *    ExtendedConnect: this request is for a WebTransport session. In this
+ *                         state RecvMessage will not be treated as a HTTP
+ *                         stream anymore. It is waiting to be transformed
+ *                         into WebTransport session or to be closed.
+ */
+#[derive(Debug)]
+enum RecvMessageState {
+    WaitingForResponseHeaders { frame_reader: FrameReader },
+    DecodingHeaders { header_block: Vec<u8>, fin: bool },
+    WaitingForData { frame_reader: FrameReader },
+    ReadingData { remaining_data_len: usize },
+    WaitingForFinAfterTrailers { frame_reader: FrameReader },
+    ClosePending, // Close must first be read by application
+    Closed,
+    ExtendedConnect,
+}
+
+#[derive(Debug)]
+struct PushInfo {
+    push_id: u64,
+    header_block: Vec<u8>,
+}
+
+#[derive(Debug)]
+pub(crate) struct RecvMessage {
+    state: RecvMessageState,
+    message_type: MessageType,
+    stream_type: Http3StreamType,
+    qpack_decoder: Rc<RefCell<QPackDecoder>>,
+    conn_events: Box<dyn HttpRecvStreamEvents>,
+    push_handler: Option<Rc<RefCell<PushController>>>,
+    stream_id: StreamId,
+    priority_handler: PriorityHandler,
+    blocked_push_promise: VecDeque<PushInfo>,
+}
+
+impl ::std::fmt::Display for RecvMessage {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "RecvMessage stream_id:{}", self.stream_id)
+    }
+}
+
+impl RecvMessage {
+    pub fn new(
+        message_info: &RecvMessageInfo,
+        qpack_decoder: Rc<RefCell<QPackDecoder>>,
+        conn_events: Box<dyn HttpRecvStreamEvents>,
+        push_handler: Option<Rc<RefCell<PushController>>>,
+        priority_handler: PriorityHandler,
+    ) -> Self {
+        Self {
+            state: RecvMessageState::WaitingForResponseHeaders {
+                frame_reader: if message_info.header_frame_type_read {
+                    FrameReader::new_with_type(H3_FRAME_TYPE_HEADERS)
+                } else {
+                    FrameReader::new()
+                },
+            },
+            message_type: message_info.message_type,
+            stream_type: message_info.stream_type,
+            qpack_decoder,
+            conn_events,
+            push_handler,
+            stream_id: message_info.stream_id,
+            priority_handler,
+            blocked_push_promise: VecDeque::new(),
+        }
+    }
+
+    fn handle_headers_frame(&mut self, header_block: Vec<u8>, fin: bool) -> Res<()> {
+        match self.state {
+            RecvMessageState::WaitingForResponseHeaders {..} => {
+                if header_block.is_empty() {
+                    return Err(Error::HttpGeneralProtocolStream);
+                }
+                    self.state = RecvMessageState::DecodingHeaders { header_block, fin };
+             }
+            RecvMessageState::WaitingForData { ..} => {
+                // TODO implement trailers, for now just ignore them.
+                self.state = RecvMessageState::WaitingForFinAfterTrailers{frame_reader: FrameReader::new()};
+            }
+            RecvMessageState::WaitingForFinAfterTrailers {..} => {
+                return Err(Error::HttpFrameUnexpected);
+            }
+            _ => unreachable!("This functions is only called in WaitingForResponseHeaders | WaitingForData | WaitingForFinAfterTrailers state.")
+         }
+        Ok(())
+    }
+
+    fn handle_data_frame(&mut self, len: u64, fin: bool) -> Res<()> {
+        match self.state {
+            RecvMessageState::WaitingForResponseHeaders {..} | RecvMessageState::WaitingForFinAfterTrailers {..} => {
+                return Err(Error::HttpFrameUnexpected);
+            }
+            RecvMessageState::WaitingForData {..} => {
+                if len > 0 {
+                    if fin {
+                        return Err(Error::HttpFrame);
+                    }
+                    self.state = RecvMessageState::ReadingData {
+                        remaining_data_len: usize::try_from(len).or(Err(Error::HttpFrame))?,
+                    };
+                }
+            }
+            _ => unreachable!("This functions is only called in WaitingForResponseHeaders | WaitingForData | WaitingForFinAfterTrailers state.")
+        }
+        Ok(())
+    }
+
+    fn add_headers(&mut self, mut headers: Vec<Header>, fin: bool) -> Res<()> {
+        qtrace!([self], "Add new headers fin={}", fin);
+        let interim = match self.message_type {
+            MessageType::Request => false,
+            MessageType::Response => is_interim(&headers)?,
+        };
+        headers_valid(&headers, self.message_type)?;
+        if self.message_type == MessageType::Response {
+            headers.retain(Header::is_allowed_for_response);
+        }
+
+        if fin && interim {
+            return Err(Error::HttpGeneralProtocolStream);
+        }
+
+        let is_web_transport = self.message_type == MessageType::Request
+            && headers
+                .iter()
+                .any(|h| h.name() == ":method" && h.value() == "CONNECT")
+            && headers
+                .iter()
+                .any(|h| h.name() == ":protocol" && h.value() == "webtransport");
+        if is_web_transport {
+            self.conn_events
+                .extended_connect_new_session(self.stream_id, headers);
+        } else {
+            self.conn_events
+                .header_ready(self.get_stream_info(), headers, interim, fin);
+        }
+
+        if fin {
+            self.set_closed();
+        } else {
+            self.state = if is_web_transport {
+                self.stream_type = Http3StreamType::ExtendedConnect;
+                RecvMessageState::ExtendedConnect
+            } else if interim {
+                RecvMessageState::WaitingForResponseHeaders {
+                    frame_reader: FrameReader::new(),
+                }
+            } else {
+                RecvMessageState::WaitingForData {
+                    frame_reader: FrameReader::new(),
+                }
+            };
+        }
+        Ok(())
+    }
+
+    fn set_state_to_close_pending(&mut self, post_readable_event: bool) -> Res<()> {
+        // Stream has received fin. Depending on headers state set header_ready
+        // or data_readable event so that app can pick up the fin.
+        qtrace!([self], "set_state_to_close_pending: state={:?}", self.state);
+
+        match self.state {
+            RecvMessageState::WaitingForResponseHeaders { .. } => {
+                return Err(Error::HttpGeneralProtocolStream);
+            }
+            RecvMessageState::ReadingData { .. } => {}
+            RecvMessageState::WaitingForData { .. }
+            | RecvMessageState::WaitingForFinAfterTrailers { .. } => {
+                if post_readable_event {
+                    self.conn_events.data_readable(self.get_stream_info());
+                }
+            }
+            _ => unreachable!("Closing an already closed transaction."),
+        }
+        if !matches!(self.state, RecvMessageState::Closed) {
+            self.state = RecvMessageState::ClosePending;
+        }
+        Ok(())
+    }
+
+    fn handle_push_promise(&mut self, push_id: u64, header_block: Vec<u8>) -> Res<()> {
+        if self.push_handler.is_none() {
+            return Err(Error::HttpFrameUnexpected);
+        }
+
+        if !self.blocked_push_promise.is_empty() {
+            self.blocked_push_promise.push_back(PushInfo {
+                push_id,
+                header_block,
+            });
+        } else if let Some(headers) = self
+            .qpack_decoder
+            .borrow_mut()
+            .decode_header_block(&header_block, self.stream_id)?
+        {
+            self.push_handler
+                .as_ref()
+                .ok_or(Error::HttpFrameUnexpected)?
+                .borrow_mut()
+                .new_push_promise(push_id, self.stream_id, headers)?;
+        } else {
+            self.blocked_push_promise.push_back(PushInfo {
+                push_id,
+                header_block,
+            });
+        }
+        Ok(())
+    }
+
+    fn receive_internal(&mut self, conn: &mut Connection, post_readable_event: bool) -> Res<()> {
+        let label = ::neqo_common::log_subject!(::log::Level::Debug, self);
+        loop {
+            qdebug!([label], "state={:?}.", self.state);
+            match &mut self.state {
+                // In the following 3 states we need to read frames.
+                RecvMessageState::WaitingForResponseHeaders { frame_reader }
+                | RecvMessageState::WaitingForData { frame_reader }
+                | RecvMessageState::WaitingForFinAfterTrailers { frame_reader } => {
+                    match frame_reader.receive(&mut StreamReaderConnectionWrapper::new(
+                        conn,
+                        self.stream_id,
+                    ))? {
+                        (None, true) => {
+                            break self.set_state_to_close_pending(post_readable_event);
+                        }
+                        (None, false) => break Ok(()),
+                        (Some(frame), fin) => {
+                            qinfo!(
+                                [self],
+                                "A new frame has been received: {:?}; state={:?} fin={}",
+                                frame,
+                                self.state,
+                                fin,
+                            );
+                            match frame {
+                                HFrame::Headers { header_block } => {
+                                    self.handle_headers_frame(header_block, fin)?;
+                                }
+                                HFrame::Data { len } => self.handle_data_frame(len, fin)?,
+                                HFrame::PushPromise {
+                                    push_id,
+                                    header_block,
+                                } => self.handle_push_promise(push_id, header_block)?,
+                                _ => break Err(Error::HttpFrameUnexpected),
+                            }
+                            if matches!(self.state, RecvMessageState::Closed) {
+                                break Ok(());
+                            }
+                            if fin
+                                && !matches!(self.state, RecvMessageState::DecodingHeaders { .. })
+                            {
+                                break self.set_state_to_close_pending(post_readable_event);
+                            }
+                        }
+                    };
+                }
+                RecvMessageState::DecodingHeaders {
+                    ref header_block,
+                    fin,
+                } => {
+                    if self
+                        .qpack_decoder
+                        .borrow()
+                        .refers_dynamic_table(header_block)?
+                        && !self.blocked_push_promise.is_empty()
+                    {
+                        qinfo!(
+                            [self],
+                            "decoding header is blocked waiting for a push_promise header block."
+                        );
+                        break Ok(());
+                    }
+                    let done = *fin;
+                    let d_headers = self
+                        .qpack_decoder
+                        .borrow_mut()
+                        .decode_header_block(header_block, self.stream_id)?;
+                    if let Some(headers) = d_headers {
+                        self.add_headers(headers, done)?;
+                        if matches!(
+                            self.state,
+                            RecvMessageState::Closed | RecvMessageState::ExtendedConnect
+                        ) {
+                            break Ok(());
+                        }
+                    } else {
+                        qinfo!([self], "decoding header is blocked.");
+                        break Ok(());
+                    }
+                }
+                RecvMessageState::ReadingData { .. } => {
+                    if post_readable_event {
+                        self.conn_events.data_readable(self.get_stream_info());
+                    }
+                    break Ok(());
+                }
+                RecvMessageState::ClosePending | RecvMessageState::Closed => {
+                    panic!("Stream readable after being closed!");
+                }
+                RecvMessageState::ExtendedConnect => {
+                    // Ignore read event, this request is waiting to be picked up by a new
+                    // WebTransportSession
+                    break Ok(());
+                }
+            };
+        }
+    }
+
+    fn set_closed(&mut self) {
+        if !self.blocked_push_promise.is_empty() {
+            self.qpack_decoder
+                .borrow_mut()
+                .cancel_stream(self.stream_id);
+        }
+        self.state = RecvMessageState::Closed;
+        self.conn_events
+            .recv_closed(self.get_stream_info(), CloseType::Done);
+    }
+
+    fn closing(&self) -> bool {
+        matches!(
+            self.state,
+            RecvMessageState::ClosePending | RecvMessageState::Closed
+        )
+    }
+
+    fn get_stream_info(&self) -> Http3StreamInfo {
+        Http3StreamInfo::new(self.stream_id, Http3StreamType::Http)
+    }
+}
+
+impl Stream for RecvMessage {
+    fn stream_type(&self) -> Http3StreamType {
+        self.stream_type
+    }
+}
+
+impl RecvStream for RecvMessage {
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        self.receive_internal(conn, true)?;
+        Ok((
+            ReceiveOutput::NoOutput,
+            matches!(self.state, RecvMessageState::Closed),
+        ))
+    }
+
+    fn reset(&mut self, close_type: CloseType) -> Res<()> {
+        if !self.closing() || !self.blocked_push_promise.is_empty() {
+            self.qpack_decoder
+                .borrow_mut()
+                .cancel_stream(self.stream_id);
+        }
+        self.conn_events
+            .recv_closed(self.get_stream_info(), close_type);
+        self.state = RecvMessageState::Closed;
+        Ok(())
+    }
+
+    fn read_data(&mut self, conn: &mut Connection, buf: &mut [u8]) -> Res<(usize, bool)> {
+        let mut written = 0;
+        loop {
+            match self.state {
+                RecvMessageState::ReadingData {
+                    ref mut remaining_data_len,
+                } => {
+                    let to_read = min(*remaining_data_len, buf.len() - written);
+                    let (amount, fin) = conn
+                        .stream_recv(self.stream_id, &mut buf[written..written + to_read])
+                        .map_err(|e| Error::map_stream_recv_errors(&Error::from(e)))?;
+                    qlog::h3_data_moved_up(conn.qlog_mut(), self.stream_id, amount);
+
+                    debug_assert!(amount <= to_read);
+                    *remaining_data_len -= amount;
+                    written += amount;
+
+                    if fin {
+                        if *remaining_data_len > 0 {
+                            return Err(Error::HttpFrame);
+                        }
+                        self.set_closed();
+                        break Ok((written, fin));
+                    } else if *remaining_data_len == 0 {
+                        self.state = RecvMessageState::WaitingForData {
+                            frame_reader: FrameReader::new(),
+                        };
+                        self.receive_internal(conn, false)?;
+                    } else {
+                        break Ok((written, false));
+                    }
+                }
+                RecvMessageState::ClosePending => {
+                    self.set_closed();
+                    break Ok((written, true));
+                }
+                _ => break Ok((written, false)),
+            }
+        }
+    }
+
+    fn http_stream(&mut self) -> Option<&mut dyn HttpRecvStream> {
+        Some(self)
+    }
+}
+
+impl HttpRecvStream for RecvMessage {
+    fn header_unblocked(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        while let Some(p) = self.blocked_push_promise.front() {
+            if let Some(headers) = self
+                .qpack_decoder
+                .borrow_mut()
+                .decode_header_block(&p.header_block, self.stream_id)?
+            {
+                self.push_handler
+                    .as_ref()
+                    .ok_or(Error::HttpFrameUnexpected)?
+                    .borrow_mut()
+                    .new_push_promise(p.push_id, self.stream_id, headers)?;
+                self.blocked_push_promise.pop_front();
+            } else {
+                return Ok((ReceiveOutput::NoOutput, false));
+            }
+        }
+
+        self.receive(conn)
+    }
+
+    fn maybe_update_priority(&mut self, priority: Priority) -> bool {
+        self.priority_handler.maybe_update_priority(priority)
+    }
+
+    fn priority_update_frame(&mut self) -> Option<HFrame> {
+        self.priority_handler.maybe_encode_frame(self.stream_id)
+    }
+
+    fn priority_update_sent(&mut self) {
+        self.priority_handler.priority_update_sent();
+    }
+
+    fn set_new_listener(&mut self, conn_events: Box<dyn HttpRecvStreamEvents>) {
+        self.state = RecvMessageState::WaitingForData {
+            frame_reader: FrameReader::new(),
+        };
+        self.conn_events = conn_events;
+    }
+
+    fn extended_connect_wait_for_response(&self) -> bool {
+        matches!(self.state, RecvMessageState::ExtendedConnect)
+    }
+
+    fn any(&self) -> &dyn Any {
+        self
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/request_target.rs b/third_party/rust/neqo-http3/src/request_target.rs
new file mode 100644
index 0000000000..28bc22ac2d
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/request_target.rs
@@ -0,0 +1,130 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::fmt::{Debug, Formatter};
+
+use url::{ParseError, Url};
+
+pub trait RequestTarget: Debug {
+    fn scheme(&self) -> &str;
+    fn authority(&self) -> &str;
+    fn path(&self) -> &str;
+}
+
+pub struct RefRequestTarget<'s, 'a, 'p> {
+    scheme: &'s str,
+    authority: &'a str,
+    path: &'p str,
+}
+
+impl RequestTarget for RefRequestTarget<'_, '_, '_> {
+    fn scheme(&self) -> &str {
+        self.scheme
+    }
+
+    fn authority(&self) -> &str {
+        self.authority
+    }
+
+    fn path(&self) -> &str {
+        self.path
+    }
+}
+
+impl<'s, 'a, 'p> RefRequestTarget<'s, 'a, 'p> {
+    #[must_use]
+    pub fn new(scheme: &'s str, authority: &'a str, path: &'p str) -> Self {
+        Self {
+            scheme,
+            authority,
+            path,
+        }
+    }
+}
+
+impl Debug for RefRequestTarget<'_, '_, '_> {
+    fn fmt(&self, f: &mut Formatter) -> ::std::fmt::Result {
+        write!(f, "{}://{}{}", self.scheme, self.authority, self.path)
+    }
+}
+
+/// `AsRequestTarget` is a trait that produces a `RequestTarget` that
+/// refers to the identified object.
+pub trait AsRequestTarget<'x> {
+    type Target: RequestTarget;
+    type Error;
+    /// Produce a `RequestTarget` that refers to `self`.
+    ///
+    /// # Errors
+    ///
+    /// This method can generate an error of type `Self::Error`
+    /// if the conversion is unsuccessful.
+    fn as_request_target(&'x self) -> Result<Self::Target, Self::Error>;
+}
+
+impl<'x, S, A, P> AsRequestTarget<'x> for (S, A, P)
+where
+    S: AsRef<str> + 'x,
+    A: AsRef<str> + 'x,
+    P: AsRef<str> + 'x,
+{
+    type Target = RefRequestTarget<'x, 'x, 'x>;
+    type Error = ();
+    fn as_request_target(&'x self) -> Result<Self::Target, Self::Error> {
+        Ok(RefRequestTarget::new(
+            self.0.as_ref(),
+            self.1.as_ref(),
+            self.2.as_ref(),
+        ))
+    }
+}
+
+impl<'x> AsRequestTarget<'x> for Url {
+    type Target = RefRequestTarget<'x, 'x, 'x>;
+    type Error = ();
+    fn as_request_target(&'x self) -> Result<Self::Target, Self::Error> {
+        Ok(RefRequestTarget::new(
+            self.scheme(),
+            self.host_str().unwrap_or(""),
+            self.path(),
+        ))
+    }
+}
+
+pub struct UrlRequestTarget {
+    url: Url,
+}
+
+impl RequestTarget for UrlRequestTarget {
+    fn scheme(&self) -> &str {
+        self.url.scheme()
+    }
+
+    fn authority(&self) -> &str {
+        self.url.host_str().unwrap_or("")
+    }
+
+    fn path(&self) -> &str {
+        self.url.path()
+    }
+}
+
+impl Debug for UrlRequestTarget {
+    fn fmt(&self, f: &mut Formatter) -> ::std::fmt::Result {
+        self.url.fmt(f)
+    }
+}
+
+impl<'x> AsRequestTarget<'x> for str {
+    type Target = UrlRequestTarget;
+    type Error = ParseError;
+    fn as_request_target(&'x self) -> Result<Self::Target, Self::Error> {
+        let url = Url::parse(self)?;
+        Ok(UrlRequestTarget { url })
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/send_message.rs b/third_party/rust/neqo-http3/src/send_message.rs
new file mode 100644
index 0000000000..96156938a0
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/send_message.rs
@@ -0,0 +1,345 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{any::Any, cell::RefCell, cmp::min, fmt::Debug, rc::Rc};
+
+use neqo_common::{qdebug, qinfo, qtrace, Encoder, Header, MessageType};
+use neqo_qpack::encoder::QPackEncoder;
+use neqo_transport::{streams::SendOrder, Connection, StreamId};
+
+use crate::{
+    frames::HFrame,
+    headers_checks::{headers_valid, is_interim, trailers_valid},
+    qlog, BufferedStream, CloseType, Error, Http3StreamInfo, Http3StreamType, HttpSendStream, Res,
+    SendStream, SendStreamEvents, Stream,
+};
+
+const MAX_DATA_HEADER_SIZE_2: usize = (1 << 6) - 1; // Maximal amount of data with DATA frame header size 2
+const MAX_DATA_HEADER_SIZE_2_LIMIT: usize = MAX_DATA_HEADER_SIZE_2 + 3; // 63 + 3 (size of the next buffer data frame header)
+const MAX_DATA_HEADER_SIZE_3: usize = (1 << 14) - 1; // Maximal amount of data with DATA frame header size 3
+const MAX_DATA_HEADER_SIZE_3_LIMIT: usize = MAX_DATA_HEADER_SIZE_3 + 5; // 16383 + 5 (size of the next buffer data frame header)
+const MAX_DATA_HEADER_SIZE_5: usize = (1 << 30) - 1; // Maximal amount of data with DATA frame header size 3
+const MAX_DATA_HEADER_SIZE_5_LIMIT: usize = MAX_DATA_HEADER_SIZE_5 + 9; // 1073741823 + 9 (size of the next buffer data frame header)
+
+/// A HTTP message, request and response, consists of headers, optional data and an optional
+/// trailer header block. This state machine does not reflect what was already sent to the
+/// transport layer but only reflect what has been supplied to the `SendMessage`.It is
+/// represented by the following states:
+///   `WaitingForHeaders` - the headers have not been supplied yet. In this state only a
+///                         request/response header can be added. When headers are supplied
+///                         the state changes to `WaitingForData`. A response may contain
+///                         multiple messages only if all but the last one are informational(1xx)
+///                         responses. The informational responses can only contain headers,
+///                         therefore after an informational response is received the state
+///                         machine states in `WaitingForHeaders` state.
+///   `WaitingForData` - in this state, data and trailers can be supplied. This state means that
+///                      a request or response header is already supplied.
+///   `TrailersSet` - trailers have been supplied. At this stage no more data or headers can be
+///                   supply only a fin.
+///   `Done` - in this state no more data or headers can be added. This state is entered when the
+///            message is closed.
+
+#[derive(Debug, PartialEq)]
+enum MessageState {
+    WaitingForHeaders,
+    WaitingForData,
+    TrailersSet,
+    Done,
+}
+
+impl MessageState {
+    fn new_headers(&mut self, headers: &[Header], message_type: MessageType) -> Res<()> {
+        match &self {
+            Self::WaitingForHeaders => {
+                // This is only a debug assertion because we expect that application will
+                // do the right thing here and performing the check costs.
+                debug_assert!(headers_valid(headers, message_type).is_ok());
+                match message_type {
+                    MessageType::Request => {
+                        *self = Self::WaitingForData;
+                    }
+                    MessageType::Response => {
+                        if !is_interim(headers)? {
+                            *self = Self::WaitingForData;
+                        }
+                    }
+                }
+                Ok(())
+            }
+            Self::WaitingForData => {
+                trailers_valid(headers)?;
+                *self = Self::TrailersSet;
+                Ok(())
+            }
+            Self::TrailersSet | Self::Done => Err(Error::InvalidInput),
+        }
+    }
+
+    fn new_data(&self) -> Res<()> {
+        if &Self::WaitingForData == self {
+            Ok(())
+        } else {
+            Err(Error::InvalidInput)
+        }
+    }
+
+    fn fin(&mut self) -> Res<()> {
+        match &self {
+            Self::WaitingForHeaders | Self::Done => Err(Error::InvalidInput),
+            Self::WaitingForData | Self::TrailersSet => {
+                *self = Self::Done;
+                Ok(())
+            }
+        }
+    }
+
+    fn done(&self) -> bool {
+        &Self::Done == self
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct SendMessage {
+    state: MessageState,
+    message_type: MessageType,
+    stream_type: Http3StreamType,
+    stream: BufferedStream,
+    encoder: Rc<RefCell<QPackEncoder>>,
+    conn_events: Box<dyn SendStreamEvents>,
+}
+
+impl SendMessage {
+    pub fn new(
+        message_type: MessageType,
+        stream_type: Http3StreamType,
+        stream_id: StreamId,
+        encoder: Rc<RefCell<QPackEncoder>>,
+        conn_events: Box<dyn SendStreamEvents>,
+    ) -> Self {
+        qinfo!("Create a request stream_id={}", stream_id);
+        Self {
+            state: MessageState::WaitingForHeaders,
+            message_type,
+            stream_type,
+            stream: BufferedStream::new(stream_id),
+            encoder,
+            conn_events,
+        }
+    }
+
+    /// # Errors
+    ///
+    /// `ClosedCriticalStream` if the encoder stream is closed.
+    /// `InternalError` if an unexpected error occurred.
+    fn encode(
+        encoder: &mut QPackEncoder,
+        headers: &[Header],
+        conn: &mut Connection,
+        stream_id: StreamId,
+    ) -> Vec<u8> {
+        qdebug!("Encoding headers");
+        let header_block = encoder.encode_header_block(conn, headers, stream_id);
+        let hframe = HFrame::Headers {
+            header_block: header_block.to_vec(),
+        };
+        let mut d = Encoder::default();
+        hframe.encode(&mut d);
+        d.into()
+    }
+
+    fn stream_id(&self) -> StreamId {
+        Option::<StreamId>::from(&self.stream).unwrap()
+    }
+
+    fn get_stream_info(&self) -> Http3StreamInfo {
+        Http3StreamInfo::new(self.stream_id(), Http3StreamType::Http)
+    }
+}
+
+impl Stream for SendMessage {
+    fn stream_type(&self) -> Http3StreamType {
+        self.stream_type
+    }
+}
+impl SendStream for SendMessage {
+    fn send_data(&mut self, conn: &mut Connection, buf: &[u8]) -> Res<usize> {
+        qtrace!([self], "send_body: len={}", buf.len());
+
+        self.state.new_data()?;
+
+        self.stream.send_buffer(conn)?;
+        if self.stream.has_buffered_data() {
+            return Ok(0);
+        }
+        let available = conn
+            .stream_avail_send_space(self.stream_id())
+            .map_err(|e| Error::map_stream_send_errors(&e.into()))?;
+        if available <= 2 {
+            return Ok(0);
+        }
+        let to_send = if available <= MAX_DATA_HEADER_SIZE_2_LIMIT {
+            // 63 + 3
+            min(min(buf.len(), available - 2), MAX_DATA_HEADER_SIZE_2)
+        } else if available <= MAX_DATA_HEADER_SIZE_3_LIMIT {
+            // 16383 + 5
+            min(min(buf.len(), available - 3), MAX_DATA_HEADER_SIZE_3)
+        } else if available <= MAX_DATA_HEADER_SIZE_5 {
+            // 1073741823 + 9
+            min(min(buf.len(), available - 5), MAX_DATA_HEADER_SIZE_5_LIMIT)
+        } else {
+            min(buf.len(), available - 9)
+        };
+
+        qinfo!(
+            [self],
+            "send_request_body: available={} to_send={}.",
+            available,
+            to_send
+        );
+
+        let data_frame = HFrame::Data {
+            len: to_send as u64,
+        };
+        let mut enc = Encoder::default();
+        data_frame.encode(&mut enc);
+        let sent_fh = self
+            .stream
+            .send_atomic(conn, enc.as_ref())
+            .map_err(|e| Error::map_stream_send_errors(&e))?;
+        debug_assert!(sent_fh);
+
+        let sent = self
+            .stream
+            .send_atomic(conn, &buf[..to_send])
+            .map_err(|e| Error::map_stream_send_errors(&e))?;
+        debug_assert!(sent);
+        qlog::h3_data_moved_down(conn.qlog_mut(), self.stream_id(), to_send);
+        Ok(to_send)
+    }
+
+    fn done(&self) -> bool {
+        !self.stream.has_buffered_data() && self.state.done()
+    }
+
+    fn stream_writable(&self) {
+        if !self.stream.has_buffered_data() && !self.state.done() {
+            // DataWritable is just a signal for an application to try to write more data,
+            // if writing fails it is fine. Therefore we do not need to properly check
+            // whether more credits are available on the transport layer.
+            self.conn_events.data_writable(self.get_stream_info());
+        }
+    }
+
+    /// # Errors
+    ///
+    /// `InternalError` if an unexpected error occurred.
+    /// `InvalidStreamId` if the stream does not exist,
+    /// `AlreadyClosed` if the stream has already been closed.
+    /// `TransportStreamDoesNotExist` if the transport stream does not exist (this may happen if
+    /// `process_output` has not been called when needed, and HTTP3 layer has not picked up the
+    /// info that the stream has been closed.)
+    fn send(&mut self, conn: &mut Connection) -> Res<()> {
+        let sent = Error::map_error(self.stream.send_buffer(conn), Error::HttpInternal(5))?;
+        qlog::h3_data_moved_down(conn.qlog_mut(), self.stream_id(), sent);
+
+        qtrace!([self], "{} bytes sent", sent);
+        if !self.stream.has_buffered_data() {
+            if self.state.done() {
+                Error::map_error(
+                    conn.stream_close_send(self.stream_id()),
+                    Error::HttpInternal(6),
+                )?;
+                qtrace!([self], "done sending request");
+            } else {
+                // DataWritable is just a signal for an application to try to write more data,
+                // if writing fails it is fine. Therefore we do not need to properly check
+                // whether more credits are available on the transport layer.
+                self.conn_events.data_writable(self.get_stream_info());
+            }
+        }
+        Ok(())
+    }
+
+    // SendMessage owns headers and sends them. It may also own data for the server side.
+    // This method returns if they're still being sent. Request body (if any) is sent by
+    // http client afterwards using `send_request_body` after receiving DataWritable event.
+    fn has_data_to_send(&self) -> bool {
+        self.stream.has_buffered_data()
+    }
+
+    fn set_sendorder(&mut self, _conn: &mut Connection, _sendorder: Option<SendOrder>) -> Res<()> {
+        // Not relevant for SendMessage
+        Ok(())
+    }
+
+    fn set_fairness(&mut self, _conn: &mut Connection, _fairness: bool) -> Res<()> {
+        // Not relevant for SendMessage
+        Ok(())
+    }
+
+    fn close(&mut self, conn: &mut Connection) -> Res<()> {
+        self.state.fin()?;
+        if !self.stream.has_buffered_data() {
+            conn.stream_close_send(self.stream_id())?;
+        }
+
+        self.conn_events
+            .send_closed(self.get_stream_info(), CloseType::Done);
+        Ok(())
+    }
+
+    fn handle_stop_sending(&mut self, close_type: CloseType) {
+        if !self.state.done() {
+            self.conn_events
+                .send_closed(self.get_stream_info(), close_type);
+        }
+    }
+
+    fn http_stream(&mut self) -> Option<&mut dyn HttpSendStream> {
+        Some(self)
+    }
+
+    fn send_data_atomic(&mut self, conn: &mut Connection, buf: &[u8]) -> Res<()> {
+        let data_frame = HFrame::Data {
+            len: buf.len() as u64,
+        };
+        let mut enc = Encoder::default();
+        data_frame.encode(&mut enc);
+        self.stream.buffer(enc.as_ref());
+        self.stream.buffer(buf);
+        _ = self.stream.send_buffer(conn)?;
+        Ok(())
+    }
+}
+
+impl HttpSendStream for SendMessage {
+    fn send_headers(&mut self, headers: &[Header], conn: &mut Connection) -> Res<()> {
+        self.state.new_headers(headers, self.message_type)?;
+        let buf = SendMessage::encode(
+            &mut self.encoder.borrow_mut(),
+            headers,
+            conn,
+            self.stream_id(),
+        );
+        self.stream.buffer(&buf);
+        Ok(())
+    }
+
+    fn set_new_listener(&mut self, conn_events: Box<dyn SendStreamEvents>) {
+        self.stream_type = Http3StreamType::ExtendedConnect;
+        self.conn_events = conn_events;
+    }
+
+    fn any(&self) -> &dyn Any {
+        self
+    }
+}
+
+impl ::std::fmt::Display for SendMessage {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "SendMesage {}", self.stream_id())
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/server.rs b/third_party/rust/neqo-http3/src/server.rs
new file mode 100644
index 0000000000..b29f715451
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/server.rs
@@ -0,0 +1,1329 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{
+    cell::{RefCell, RefMut},
+    collections::HashMap,
+    path::PathBuf,
+    rc::Rc,
+    time::Instant,
+};
+
+use neqo_common::{qtrace, Datagram};
+use neqo_crypto::{AntiReplay, Cipher, PrivateKey, PublicKey, ZeroRttChecker};
+use neqo_transport::{
+    server::{ActiveConnectionRef, Server, ValidateAddress},
+    ConnectionIdGenerator, Output,
+};
+
+use crate::{
+    connection::Http3State,
+    connection_server::Http3ServerHandler,
+    server_connection_events::Http3ServerConnEvent,
+    server_events::{
+        Http3OrWebTransportStream, Http3ServerEvent, Http3ServerEvents, WebTransportRequest,
+    },
+    settings::HttpZeroRttChecker,
+    Http3Parameters, Http3StreamInfo, Res,
+};
+
+type HandlerRef = Rc<RefCell<Http3ServerHandler>>;
+
+const MAX_EVENT_DATA_SIZE: usize = 1024;
+
+pub struct Http3Server {
+    server: Server,
+    http3_parameters: Http3Parameters,
+    http3_handlers: HashMap<ActiveConnectionRef, HandlerRef>,
+    events: Http3ServerEvents,
+}
+
+impl ::std::fmt::Display for Http3Server {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Http3 server ")
+    }
+}
+
+impl Http3Server {
+    /// # Errors
+    ///
+    /// Making a `neqo_transport::Server` may produce an error. This can only be a crypto error if
+    /// the socket can't be created or configured.
+    pub fn new(
+        now: Instant,
+        certs: &[impl AsRef<str>],
+        protocols: &[impl AsRef<str>],
+        anti_replay: AntiReplay,
+        cid_manager: Rc<RefCell<dyn ConnectionIdGenerator>>,
+        http3_parameters: Http3Parameters,
+        zero_rtt_checker: Option<Box<dyn ZeroRttChecker>>,
+    ) -> Res<Self> {
+        Ok(Self {
+            server: Server::new(
+                now,
+                certs,
+                protocols,
+                anti_replay,
+                zero_rtt_checker
+                    .unwrap_or_else(|| Box::new(HttpZeroRttChecker::new(http3_parameters.clone()))),
+                cid_manager,
+                http3_parameters.get_connection_parameters().clone(),
+            )?,
+            http3_parameters,
+            http3_handlers: HashMap::new(),
+            events: Http3ServerEvents::default(),
+        })
+    }
+
+    pub fn set_qlog_dir(&mut self, dir: Option<PathBuf>) {
+        self.server.set_qlog_dir(dir);
+    }
+
+    pub fn set_validation(&mut self, v: ValidateAddress) {
+        self.server.set_validation(v);
+    }
+
+    pub fn set_ciphers(&mut self, ciphers: impl AsRef<[Cipher]>) {
+        self.server.set_ciphers(ciphers);
+    }
+
+    /// Enable encrypted client hello (ECH).
+    ///
+    /// # Errors
+    ///
+    /// Only when NSS can't serialize a configuration.
+    pub fn enable_ech(
+        &mut self,
+        config: u8,
+        public_name: &str,
+        sk: &PrivateKey,
+        pk: &PublicKey,
+    ) -> Res<()> {
+        self.server.enable_ech(config, public_name, sk, pk)?;
+        Ok(())
+    }
+
+    #[must_use]
+    pub fn ech_config(&self) -> &[u8] {
+        self.server.ech_config()
+    }
+
+    pub fn process(&mut self, dgram: Option<&Datagram>, now: Instant) -> Output {
+        qtrace!([self], "Process.");
+        let out = self.server.process(dgram, now);
+        self.process_http3(now);
+        // If we do not that a dgram already try again after process_http3.
+        match out {
+            Output::Datagram(d) => {
+                qtrace!([self], "Send packet: {:?}", d);
+                Output::Datagram(d)
+            }
+            _ => self.server.process(Option::<&Datagram>::None, now),
+        }
+    }
+
+    /// Process HTTP3 layer.
+    fn process_http3(&mut self, now: Instant) {
+        qtrace!([self], "Process http3 internal.");
+        let mut active_conns = self.server.active_connections();
+
+        // We need to find connections that needs to be process on http3 level.
+        let mut http3_active: Vec<ActiveConnectionRef> = self
+            .http3_handlers
+            .iter()
+            .filter_map(|(conn, handler)| {
+                if handler.borrow_mut().should_be_processed() && !active_conns.contains(conn) {
+                    Some(conn)
+                } else {
+                    None
+                }
+            })
+            .cloned()
+            .collect();
+        // For http_active connection we need to put them in neqo-transport's server
+        // waiting queue.
+        active_conns.append(&mut http3_active);
+        active_conns.dedup();
+        active_conns
+            .iter()
+            .for_each(|conn| self.server.add_to_waiting(conn.clone()));
+        for mut conn in active_conns {
+            self.process_events(&mut conn, now);
+        }
+    }
+
+    fn process_events(&mut self, conn: &mut ActiveConnectionRef, now: Instant) {
+        let mut remove = false;
+        let http3_parameters = &self.http3_parameters;
+        {
+            let handler = self.http3_handlers.entry(conn.clone()).or_insert_with(|| {
+                Rc::new(RefCell::new(Http3ServerHandler::new(
+                    http3_parameters.clone(),
+                )))
+            });
+            handler
+                .borrow_mut()
+                .process_http3(&mut conn.borrow_mut(), now);
+            let mut handler_borrowed = handler.borrow_mut();
+            while let Some(e) = handler_borrowed.next_event() {
+                match e {
+                    Http3ServerConnEvent::Headers {
+                        stream_info,
+                        headers,
+                        fin,
+                    } => self.events.headers(
+                        Http3OrWebTransportStream::new(conn.clone(), handler.clone(), stream_info),
+                        headers,
+                        fin,
+                    ),
+                    Http3ServerConnEvent::DataReadable { stream_info } => {
+                        prepare_data(
+                            stream_info,
+                            &mut handler_borrowed,
+                            conn,
+                            handler,
+                            now,
+                            &mut self.events,
+                        );
+                    }
+                    Http3ServerConnEvent::DataWritable { stream_info } => self
+                        .events
+                        .data_writable(conn.clone(), handler.clone(), stream_info),
+                    Http3ServerConnEvent::StreamReset { stream_info, error } => {
+                        self.events
+                            .stream_reset(conn.clone(), handler.clone(), stream_info, error);
+                    }
+                    Http3ServerConnEvent::StreamStopSending { stream_info, error } => {
+                        self.events.stream_stop_sending(
+                            conn.clone(),
+                            handler.clone(),
+                            stream_info,
+                            error,
+                        );
+                    }
+                    Http3ServerConnEvent::StateChange(state) => {
+                        self.events
+                            .connection_state_change(conn.clone(), state.clone());
+                        if let Http3State::Closed { .. } = state {
+                            remove = true;
+                        }
+                    }
+                    Http3ServerConnEvent::PriorityUpdate {
+                        stream_id,
+                        priority,
+                    } => {
+                        self.events.priority_update(stream_id, priority);
+                    }
+                    Http3ServerConnEvent::ExtendedConnect { stream_id, headers } => {
+                        self.events.webtransport_new_session(
+                            WebTransportRequest::new(conn.clone(), handler.clone(), stream_id),
+                            headers,
+                        );
+                    }
+                    Http3ServerConnEvent::ExtendedConnectClosed {
+                        stream_id,
+                        reason,
+                        headers,
+                        ..
+                    } => self.events.webtransport_session_closed(
+                        WebTransportRequest::new(conn.clone(), handler.clone(), stream_id),
+                        reason,
+                        headers,
+                    ),
+                    Http3ServerConnEvent::ExtendedConnectNewStream(stream_info) => self
+                        .events
+                        .webtransport_new_stream(Http3OrWebTransportStream::new(
+                            conn.clone(),
+                            handler.clone(),
+                            stream_info,
+                        )),
+                    Http3ServerConnEvent::ExtendedConnectDatagram {
+                        session_id,
+                        datagram,
+                    } => self.events.webtransport_datagram(
+                        WebTransportRequest::new(conn.clone(), handler.clone(), session_id),
+                        datagram,
+                    ),
+                }
+            }
+        }
+        if remove {
+            self.http3_handlers.remove(&conn.clone());
+        }
+    }
+
+    /// Get all current events. Best used just in debug/testing code, use
+    /// `next_event` instead.
+    pub fn events(&mut self) -> impl Iterator<Item = Http3ServerEvent> {
+        self.events.events()
+    }
+
+    /// Return true if there are outstanding events.
+    #[must_use]
+    pub fn has_events(&self) -> bool {
+        self.events.has_events()
+    }
+
+    /// Get events that indicate state changes on the connection. This method
+    /// correctly handles cases where handling one event can obsolete
+    /// previously-queued events, or cause new events to be generated.
+    pub fn next_event(&mut self) -> Option<Http3ServerEvent> {
+        self.events.next_event()
+    }
+}
+fn prepare_data(
+    stream_info: Http3StreamInfo,
+    handler_borrowed: &mut RefMut<Http3ServerHandler>,
+    conn: &mut ActiveConnectionRef,
+    handler: &HandlerRef,
+    now: Instant,
+    events: &mut Http3ServerEvents,
+) {
+    loop {
+        let mut data = vec![0; MAX_EVENT_DATA_SIZE];
+        let res = handler_borrowed.read_data(
+            &mut conn.borrow_mut(),
+            now,
+            stream_info.stream_id(),
+            &mut data,
+        );
+        if let Ok((amount, fin)) = res {
+            if amount > 0 || fin {
+                if amount < MAX_EVENT_DATA_SIZE {
+                    data.resize(amount, 0);
+                }
+
+                events.data(conn.clone(), handler.clone(), stream_info, data, fin);
+            }
+            if amount < MAX_EVENT_DATA_SIZE || fin {
+                break;
+            }
+        } else {
+            // Any error will closed the handler, just ignore this event, the next event must
+            // be a state change event.
+            break;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{
+        collections::HashMap,
+        mem,
+        ops::{Deref, DerefMut},
+    };
+
+    use neqo_common::{event::Provider, Encoder};
+    use neqo_crypto::{AuthenticationStatus, ZeroRttCheckResult, ZeroRttChecker};
+    use neqo_qpack::{encoder::QPackEncoder, QpackSettings};
+    use neqo_transport::{
+        Connection, ConnectionError, ConnectionEvent, State, StreamId, StreamType, ZeroRttState,
+    };
+    use test_fixture::{
+        anti_replay, default_client, fixture_init, now, CountingConnectionIdGenerator,
+        DEFAULT_ALPN, DEFAULT_KEYS,
+    };
+
+    use super::{Http3Server, Http3ServerEvent, Http3State, Rc, RefCell};
+    use crate::{Error, HFrame, Header, Http3Parameters, Priority};
+
+    const DEFAULT_SETTINGS: QpackSettings = QpackSettings {
+        max_table_size_encoder: 100,
+        max_table_size_decoder: 100,
+        max_blocked_streams: 100,
+    };
+
+    fn http3params(qpack_settings: QpackSettings) -> Http3Parameters {
+        Http3Parameters::default()
+            .max_table_size_encoder(qpack_settings.max_table_size_encoder)
+            .max_table_size_decoder(qpack_settings.max_table_size_decoder)
+            .max_blocked_streams(qpack_settings.max_blocked_streams)
+    }
+
+    pub fn create_server(conn_params: Http3Parameters) -> Http3Server {
+        fixture_init();
+        Http3Server::new(
+            now(),
+            DEFAULT_KEYS,
+            DEFAULT_ALPN,
+            anti_replay(),
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            conn_params,
+            None,
+        )
+        .expect("create a server")
+    }
+
+    /// Create a http3 server with default configuration.
+    pub fn default_server() -> Http3Server {
+        create_server(http3params(DEFAULT_SETTINGS))
+    }
+
+    fn assert_closed(hconn: &mut Http3Server, expected: &Error) {
+        let err = ConnectionError::Application(expected.code());
+        let closed = |e| matches!(e, Http3ServerEvent::StateChange{ state: Http3State::Closing(e) | Http3State::Closed(e), .. } if e == err);
+        assert!(hconn.events().any(closed));
+    }
+
+    fn assert_connected(hconn: &mut Http3Server) {
+        let connected = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::StateChange {
+                    state: Http3State::Connected,
+                    ..
+                }
+            )
+        };
+        assert!(hconn.events().any(connected));
+    }
+
+    fn assert_not_closed(hconn: &mut Http3Server) {
+        let closed = |e| {
+            matches!(
+                e,
+                Http3ServerEvent::StateChange {
+                    state: Http3State::Closing(..),
+                    ..
+                }
+            )
+        };
+        assert!(!hconn.events().any(closed));
+    }
+
+    const CLIENT_SIDE_CONTROL_STREAM_ID: StreamId = StreamId::new(2);
+    const CLIENT_SIDE_ENCODER_STREAM_ID: StreamId = StreamId::new(6);
+    const CLIENT_SIDE_DECODER_STREAM_ID: StreamId = StreamId::new(10);
+    const SERVER_SIDE_CONTROL_STREAM_ID: StreamId = StreamId::new(3);
+    const SERVER_SIDE_ENCODER_STREAM_ID: StreamId = StreamId::new(7);
+    const SERVER_SIDE_DECODER_STREAM_ID: StreamId = StreamId::new(11);
+
+    fn connect_transport(server: &mut Http3Server, client: &mut Connection, resume: bool) {
+        let c1 = client.process(None, now());
+        let s1 = server.process(c1.as_dgram_ref(), now());
+        let c2 = client.process(s1.as_dgram_ref(), now());
+        let needs_auth = client
+            .events()
+            .any(|e| e == ConnectionEvent::AuthenticationNeeded);
+        let c2 = if needs_auth {
+            assert!(!resume);
+            // c2 should just be an ACK, so absorb that.
+            let s_ack = server.process(c2.as_dgram_ref(), now());
+            assert!(s_ack.as_dgram_ref().is_none());
+
+            client.authenticated(AuthenticationStatus::Ok, now());
+            client.process(None, now())
+        } else {
+            assert!(resume);
+            c2
+        };
+        assert!(client.state().connected());
+        let s2 = server.process(c2.as_dgram_ref(), now());
+        assert_connected(server);
+        let c3 = client.process(s2.as_dgram_ref(), now());
+        assert!(c3.as_dgram_ref().is_none());
+    }
+
+    // Start a client/server and check setting frame.
+    fn connect_and_receive_settings_with_server(server: &mut Http3Server) -> Connection {
+        const CONTROL_STREAM_DATA: &[u8] = &[0x0, 0x4, 0x6, 0x1, 0x40, 0x64, 0x7, 0x40, 0x64];
+
+        let mut client = default_client();
+        connect_transport(server, &mut client, false);
+
+        let mut connected = false;
+        while let Some(e) = client.next_event() {
+            match e {
+                ConnectionEvent::NewStream { stream_id } => {
+                    assert!(
+                        (stream_id == SERVER_SIDE_CONTROL_STREAM_ID)
+                            || (stream_id == SERVER_SIDE_ENCODER_STREAM_ID)
+                            || (stream_id == SERVER_SIDE_DECODER_STREAM_ID)
+                    );
+                    assert_eq!(stream_id.stream_type(), StreamType::UniDi);
+                }
+                ConnectionEvent::RecvStreamReadable { stream_id } => {
+                    if stream_id == CLIENT_SIDE_CONTROL_STREAM_ID
+                        || stream_id == SERVER_SIDE_CONTROL_STREAM_ID
+                    {
+                        // the control stream
+                        let mut buf = [0_u8; 100];
+                        let (amount, fin) = client.stream_recv(stream_id, &mut buf).unwrap();
+                        assert!(!fin);
+                        assert_eq!(amount, CONTROL_STREAM_DATA.len());
+                        assert_eq!(&buf[..9], CONTROL_STREAM_DATA);
+                    } else if stream_id == CLIENT_SIDE_ENCODER_STREAM_ID
+                        || stream_id == SERVER_SIDE_ENCODER_STREAM_ID
+                    {
+                        let mut buf = [0_u8; 100];
+                        let (amount, fin) = client.stream_recv(stream_id, &mut buf).unwrap();
+                        assert!(!fin);
+                        assert_eq!(amount, 1);
+                        assert_eq!(buf[..1], [0x2]);
+                    } else if stream_id == CLIENT_SIDE_DECODER_STREAM_ID
+                        || stream_id == SERVER_SIDE_DECODER_STREAM_ID
+                    {
+                        let mut buf = [0_u8; 100];
+                        let (amount, fin) = client.stream_recv(stream_id, &mut buf).unwrap();
+                        assert!(!fin);
+                        assert_eq!(amount, 1);
+                        assert_eq!(buf[..1], [0x3]);
+                    } else {
+                        panic!("unexpected event");
+                    }
+                }
+                ConnectionEvent::SendStreamWritable { stream_id } => {
+                    assert!(
+                        (stream_id == CLIENT_SIDE_CONTROL_STREAM_ID)
+                            || (stream_id == CLIENT_SIDE_ENCODER_STREAM_ID)
+                            || (stream_id == CLIENT_SIDE_DECODER_STREAM_ID)
+                    );
+                }
+                ConnectionEvent::StateChange(State::Connected) => connected = true,
+                ConnectionEvent::StateChange(_) | ConnectionEvent::SendStreamCreatable { .. } => (),
+                _ => panic!("unexpected event"),
+            }
+        }
+        assert!(connected);
+        client
+    }
+
+    fn connect_and_receive_settings() -> (Http3Server, Connection) {
+        // Create a server and connect it to a client.
+        // We will have a http3 server on one side and a neqo_transport
+        // connection on the other side so that we can check what the http3
+        // side sends and also to simulate an incorrectly behaving http3
+        // client.
+
+        let mut server = default_server();
+        let client = connect_and_receive_settings_with_server(&mut server);
+        (server, client)
+    }
+
+    // Test http3 connection inintialization.
+    // The server will open the control and qpack streams and send SETTINGS frame.
+    #[test]
+    fn test_server_connect() {
+        mem::drop(connect_and_receive_settings());
+    }
+
+    struct PeerConnection {
+        conn: Connection,
+        control_stream_id: StreamId,
+    }
+
+    impl PeerConnection {
+        /// A shortcut for sending on the control stream.
+        fn control_send(&mut self, data: &[u8]) {
+            let res = self.conn.stream_send(self.control_stream_id, data);
+            assert_eq!(res, Ok(data.len()));
+        }
+    }
+
+    impl Deref for PeerConnection {
+        type Target = Connection;
+        fn deref(&self) -> &Self::Target {
+            &self.conn
+        }
+    }
+
+    impl DerefMut for PeerConnection {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.conn
+        }
+    }
+
+    // Connect transport, send and receive settings.
+    fn connect_to(server: &mut Http3Server) -> PeerConnection {
+        let mut neqo_trans_conn = connect_and_receive_settings_with_server(server);
+        let control_stream = neqo_trans_conn.stream_create(StreamType::UniDi).unwrap();
+        let mut sent = neqo_trans_conn.stream_send(
+            control_stream,
+            &[0x0, 0x4, 0x6, 0x1, 0x40, 0x64, 0x7, 0x40, 0x64],
+        );
+        assert_eq!(sent, Ok(9));
+        let mut encoder = QPackEncoder::new(
+            &QpackSettings {
+                max_table_size_encoder: 100,
+                max_table_size_decoder: 0,
+                max_blocked_streams: 0,
+            },
+            true,
+        );
+        encoder.add_send_stream(neqo_trans_conn.stream_create(StreamType::UniDi).unwrap());
+        encoder.send_encoder_updates(&mut neqo_trans_conn).unwrap();
+        let decoder_stream = neqo_trans_conn.stream_create(StreamType::UniDi).unwrap();
+        sent = neqo_trans_conn.stream_send(decoder_stream, &[0x3]);
+        assert_eq!(sent, Ok(1));
+        let out1 = neqo_trans_conn.process(None, now());
+        let out2 = server.process(out1.as_dgram_ref(), now());
+        mem::drop(neqo_trans_conn.process(out2.as_dgram_ref(), now()));
+
+        // assert no error occured.
+        assert_not_closed(server);
+
+        PeerConnection {
+            conn: neqo_trans_conn,
+            control_stream_id: control_stream,
+        }
+    }
+
+    fn connect() -> (Http3Server, PeerConnection) {
+        let mut server = default_server();
+        let client = connect_to(&mut server);
+        (server, client)
+    }
+
+    // Server: Test receiving a new control stream and a SETTINGS frame.
+    #[test]
+    fn test_server_receive_control_frame() {
+        mem::drop(connect());
+    }
+
+    // Server: Test that the connection will be closed if control stream
+    // has been closed.
+    #[test]
+    fn test_server_close_control_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        let control = peer_conn.control_stream_id;
+        peer_conn.stream_close_send(control).unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: test missing SETTINGS frame
+    // (the first frame sent is a MAX_PUSH_ID frame).
+    #[test]
+    fn test_server_missing_settings() {
+        let (mut hconn, mut neqo_trans_conn) = connect_and_receive_settings();
+        // Create client control stream.
+        let control_stream = neqo_trans_conn.stream_create(StreamType::UniDi).unwrap();
+        // Send a MAX_PUSH_ID frame instead.
+        let sent = neqo_trans_conn.stream_send(control_stream, &[0x0, 0xd, 0x1, 0xf]);
+        assert_eq!(sent, Ok(4));
+        let out = neqo_trans_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpMissingSettings);
+    }
+
+    // Server: receiving SETTINGS frame twice causes connection close
+    // with error HTTP_UNEXPECTED_FRAME.
+    #[test]
+    fn test_server_receive_settings_twice() {
+        let (mut hconn, mut peer_conn) = connect();
+        // send the second SETTINGS frame.
+        peer_conn.control_send(&[0x4, 0x6, 0x1, 0x40, 0x64, 0x7, 0x40, 0x64]);
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpFrameUnexpected);
+    }
+
+    fn priority_update_check_id(stream_id: StreamId, valid: bool) {
+        let (mut hconn, mut peer_conn) = connect();
+        // send a priority update
+        let frame = HFrame::PriorityUpdateRequest {
+            element_id: stream_id.as_u64(),
+            priority: Priority::default(),
+        };
+        let mut e = Encoder::default();
+        frame.encode(&mut e);
+        peer_conn.control_send(e.as_ref());
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        // check if the given connection got closed on invalid stream ids
+        if valid {
+            assert_not_closed(&mut hconn);
+        } else {
+            assert_closed(&mut hconn, &Error::HttpId);
+        }
+    }
+
+    #[test]
+    fn test_priority_update_valid_id_0() {
+        // Client-Initiated, Bidirectional
+        priority_update_check_id(StreamId::new(0), true);
+    }
+    #[test]
+    fn test_priority_update_invalid_id_1() {
+        // Server-Initiated, Bidirectional
+        priority_update_check_id(StreamId::new(1), false);
+    }
+    #[test]
+    fn test_priority_update_invalid_id_2() {
+        // Client-Initiated, Unidirectional
+        priority_update_check_id(StreamId::new(2), false);
+    }
+    #[test]
+    fn test_priority_update_invalid_id_3() {
+        // Server-Initiated, Unidirectional
+        priority_update_check_id(StreamId::new(3), false);
+    }
+
+    #[test]
+    fn test_priority_update_invalid_large_id() {
+        // Server-Initiated, Unidirectional (divisible by 4)
+        priority_update_check_id(StreamId::new(1_000_000_000), false);
+    }
+
+    fn test_wrong_frame_on_control_stream(v: &[u8]) {
+        let (mut hconn, mut peer_conn) = connect();
+
+        // receive a frame that is not allowed on the control stream.
+        peer_conn.control_send(v);
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpFrameUnexpected);
+    }
+
+    // send DATA frame on a control stream
+    #[test]
+    fn test_server_data_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x0, 0x2, 0x1, 0x2]);
+    }
+
+    // send HEADERS frame on a cortrol stream
+    #[test]
+    fn test_server_headers_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x1, 0x2, 0x1, 0x2]);
+    }
+
+    // send PUSH_PROMISE frame on a cortrol stream
+    #[test]
+    fn test_server_push_promise_frame_on_control_stream() {
+        test_wrong_frame_on_control_stream(&[0x5, 0x2, 0x1, 0x2]);
+    }
+
+    // Server: receive unknown stream type
+    // also test getting stream id that does not fit into a single byte.
+    #[test]
+    fn test_server_received_unknown_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        // create a stream with unknown type.
+        let new_stream_id = peer_conn.stream_create(StreamType::UniDi).unwrap();
+        _ = peer_conn
+            .stream_send(new_stream_id, &[0x41, 0x19, 0x4, 0x4, 0x6, 0x0, 0x8, 0x0])
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        let out = hconn.process(out.as_dgram_ref(), now());
+        mem::drop(peer_conn.process(out.as_dgram_ref(), now()));
+        let out = hconn.process(None, now());
+        mem::drop(peer_conn.process(out.as_dgram_ref(), now()));
+
+        // check for stop-sending with Error::HttpStreamCreation.
+        let mut stop_sending_event_found = false;
+        while let Some(e) = peer_conn.next_event() {
+            if let ConnectionEvent::SendStreamStopSending {
+                stream_id,
+                app_error,
+            } = e
+            {
+                stop_sending_event_found = true;
+                assert_eq!(stream_id, new_stream_id);
+                assert_eq!(app_error, Error::HttpStreamCreation.code());
+            }
+        }
+        assert!(stop_sending_event_found);
+        assert_not_closed(&mut hconn);
+    }
+
+    // Server: receiving a push stream on a server should cause WrongStreamDirection
+    #[test]
+    fn test_server_received_push_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        // create a push stream.
+        let push_stream_id = peer_conn.stream_create(StreamType::UniDi).unwrap();
+        _ = peer_conn.stream_send(push_stream_id, &[0x1]).unwrap();
+        let out = peer_conn.process(None, now());
+        let out = hconn.process(out.as_dgram_ref(), now());
+        mem::drop(peer_conn.conn.process(out.as_dgram_ref(), now()));
+        assert_closed(&mut hconn, &Error::HttpStreamCreation);
+    }
+
+    /// Test reading of a slowly streamed frame. bytes are received one by one
+    #[test]
+    fn test_server_frame_reading() {
+        let (mut hconn, mut peer_conn) = connect_and_receive_settings();
+
+        // create a control stream.
+        let control_stream = peer_conn.stream_create(StreamType::UniDi).unwrap();
+
+        // send the stream type
+        let mut sent = peer_conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // start sending SETTINGS frame
+        sent = peer_conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x6]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x8]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x0]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        assert_not_closed(&mut hconn);
+
+        // Now test PushPromise
+        sent = peer_conn.stream_send(control_stream, &[0x5]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x5]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x4]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x61]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x62]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x63]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        sent = peer_conn.stream_send(control_stream, &[0x64]);
+        assert_eq!(sent, Ok(1));
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // PUSH_PROMISE on a control stream will cause an error
+        assert_closed(&mut hconn, &Error::HttpFrameUnexpected);
+    }
+
+    // Test reading of a slowly streamed frame. bytes are received one by one
+    fn test_incomplete_frame(res: &[u8]) {
+        let (mut hconn, mut peer_conn) = connect_and_receive_settings();
+
+        // send an incomplete reequest.
+        let stream_id = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        peer_conn.stream_send(stream_id, res).unwrap();
+        peer_conn.stream_close_send(stream_id).unwrap();
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        assert_closed(&mut hconn, &Error::HttpFrame);
+    }
+
+    const REQUEST_WITH_BODY: &[u8] = &[
+        // headers
+        0x01, 0x10, 0x00, 0x00, 0xd1, 0xd7, 0x50, 0x89, 0x41, 0xe9, 0x2a, 0x67, 0x35, 0x53, 0x2e,
+        0x43, 0xd3, 0xc1, // the first data frame.
+        0x0, 0x3, 0x61, 0x62, 0x63, // the second data frame.
+        0x0, 0x3, 0x64, 0x65, 0x66,
+    ];
+    const REQUEST_BODY: &[u8] = &[0x61, 0x62, 0x63, 0x64, 0x65, 0x66];
+
+    const RESPONSE_BODY: &[u8] = &[0x67, 0x68, 0x69];
+
+    fn check_request_header(header: &[Header]) {
+        let expected_request_header = &[
+            Header::new(":method", "GET"),
+            Header::new(":scheme", "https"),
+            Header::new(":authority", "something.com"),
+            Header::new(":path", "/"),
+        ];
+        assert_eq!(header, expected_request_header);
+    }
+
+    // Incomplete DATA frame
+    #[test]
+    fn test_server_incomplete_data_frame() {
+        test_incomplete_frame(&REQUEST_WITH_BODY[..22]);
+    }
+
+    // Incomplete HEADERS frame
+    #[test]
+    fn test_server_incomplete_headers_frame() {
+        test_incomplete_frame(&REQUEST_WITH_BODY[..10]);
+    }
+
+    #[test]
+    fn test_server_incomplete_unknown_frame() {
+        test_incomplete_frame(&[0x21]);
+    }
+
+    #[test]
+    fn test_server_request_with_body() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        let stream_id = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        peer_conn.stream_send(stream_id, REQUEST_WITH_BODY).unwrap();
+        peer_conn.stream_close_send(stream_id).unwrap();
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // Check connection event. There should be 1 Header and 2 data events.
+        let mut headers_frames = 0;
+        let mut data_received = 0;
+        while let Some(event) = hconn.next_event() {
+            match event {
+                Http3ServerEvent::Headers { headers, fin, .. } => {
+                    check_request_header(&headers);
+                    assert!(!fin);
+                    headers_frames += 1;
+                }
+                Http3ServerEvent::Data {
+                    mut stream,
+                    data,
+                    fin,
+                } => {
+                    assert_eq!(data, REQUEST_BODY);
+                    assert!(fin);
+                    stream
+                        .send_headers(&[
+                            Header::new(":status", "200"),
+                            Header::new("content-length", "3"),
+                        ])
+                        .unwrap();
+                    stream.send_data(RESPONSE_BODY).unwrap();
+                    data_received += 1;
+                }
+                Http3ServerEvent::DataWritable { .. }
+                | Http3ServerEvent::StreamReset { .. }
+                | Http3ServerEvent::StreamStopSending { .. }
+                | Http3ServerEvent::StateChange { .. }
+                | Http3ServerEvent::PriorityUpdate { .. }
+                | Http3ServerEvent::WebTransport(_) => {}
+            }
+        }
+        assert_eq!(headers_frames, 1);
+        assert_eq!(data_received, 1);
+    }
+
+    #[test]
+    fn test_server_request_with_body_send_stop_sending() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        let stream_id = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        // Send only request headers for now.
+        peer_conn
+            .stream_send(stream_id, &REQUEST_WITH_BODY[..20])
+            .unwrap();
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // Check connection event. There should be 1 Header and no data events.
+        let mut headers_frames = 0;
+        while let Some(event) = hconn.next_event() {
+            match event {
+                Http3ServerEvent::Headers {
+                    mut stream,
+                    headers,
+                    fin,
+                } => {
+                    check_request_header(&headers);
+                    assert!(!fin);
+                    headers_frames += 1;
+                    stream
+                        .stream_stop_sending(Error::HttpNoError.code())
+                        .unwrap();
+                    stream
+                        .send_headers(&[
+                            Header::new(":status", "200"),
+                            Header::new("content-length", "3"),
+                        ])
+                        .unwrap();
+                    stream.send_data(RESPONSE_BODY).unwrap();
+                }
+                Http3ServerEvent::Data { .. } => {
+                    panic!("We should not have a Data event");
+                }
+                Http3ServerEvent::DataWritable { .. }
+                | Http3ServerEvent::StreamReset { .. }
+                | Http3ServerEvent::StreamStopSending { .. }
+                | Http3ServerEvent::StateChange { .. }
+                | Http3ServerEvent::PriorityUpdate { .. }
+                | Http3ServerEvent::WebTransport(_) => {}
+            }
+        }
+        let out = hconn.process(None, now());
+
+        // Send data.
+        peer_conn
+            .stream_send(stream_id, &REQUEST_WITH_BODY[20..])
+            .unwrap();
+        peer_conn.stream_close_send(stream_id).unwrap();
+
+        let out = peer_conn.process(out.as_dgram_ref(), now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        while let Some(event) = hconn.next_event() {
+            match event {
+                Http3ServerEvent::Headers { .. } => {
+                    panic!("We should not have a Header event");
+                }
+                Http3ServerEvent::Data { .. } => {
+                    panic!("We should not have a Data event");
+                }
+                Http3ServerEvent::DataWritable { .. }
+                | Http3ServerEvent::StreamReset { .. }
+                | Http3ServerEvent::StreamStopSending { .. }
+                | Http3ServerEvent::StateChange { .. }
+                | Http3ServerEvent::PriorityUpdate { .. }
+                | Http3ServerEvent::WebTransport(_) => {}
+            }
+        }
+        assert_eq!(headers_frames, 1);
+    }
+
+    #[test]
+    fn test_server_request_with_body_server_reset() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        let request_stream_id = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        // Send only request headers for now.
+        peer_conn
+            .stream_send(request_stream_id, &REQUEST_WITH_BODY[..20])
+            .unwrap();
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // Check connection event. There should be 1 Header and no data events.
+        // The server will reset the stream.
+        let mut headers_frames = 0;
+        while let Some(event) = hconn.next_event() {
+            match event {
+                Http3ServerEvent::Headers {
+                    mut stream,
+                    headers,
+                    fin,
+                } => {
+                    check_request_header(&headers);
+                    assert!(!fin);
+                    headers_frames += 1;
+                    stream
+                        .cancel_fetch(Error::HttpRequestRejected.code())
+                        .unwrap();
+                }
+                Http3ServerEvent::Data { .. } => {
+                    panic!("We should not have a Data event");
+                }
+                Http3ServerEvent::DataWritable { .. }
+                | Http3ServerEvent::StreamReset { .. }
+                | Http3ServerEvent::StreamStopSending { .. }
+                | Http3ServerEvent::StateChange { .. }
+                | Http3ServerEvent::PriorityUpdate { .. }
+                | Http3ServerEvent::WebTransport(_) => {}
+            }
+        }
+        let out = hconn.process(None, now());
+
+        let out = peer_conn.process(out.as_dgram_ref(), now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        // Check that STOP_SENDING and REET has been received.
+        let mut reset = 0;
+        let mut stop_sending = 0;
+        while let Some(event) = peer_conn.next_event() {
+            match event {
+                ConnectionEvent::RecvStreamReset { stream_id, .. } => {
+                    assert_eq!(request_stream_id, stream_id);
+                    reset += 1;
+                }
+                ConnectionEvent::SendStreamStopSending { stream_id, .. } => {
+                    assert_eq!(request_stream_id, stream_id);
+                    stop_sending += 1;
+                }
+                _ => {}
+            }
+        }
+        assert_eq!(headers_frames, 1);
+        assert_eq!(reset, 1);
+        assert_eq!(stop_sending, 1);
+    }
+
+    // Server: Test that the connection will be closed if the local control stream
+    // has been reset.
+    #[test]
+    fn test_server_reset_control_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        peer_conn
+            .stream_reset_send(CLIENT_SIDE_CONTROL_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: Test that the connection will be closed if the client side encoder stream
+    // has been reset.
+    #[test]
+    fn test_server_reset_client_side_encoder_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        peer_conn
+            .stream_reset_send(CLIENT_SIDE_ENCODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: Test that the connection will be closed if the client side decoder stream
+    // has been reset.
+    #[test]
+    fn test_server_reset_client_side_decoder_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        peer_conn
+            .stream_reset_send(CLIENT_SIDE_DECODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: Test that the connection will be closed if the local control stream
+    // has received a stop_sending.
+    #[test]
+    fn test_client_stop_sending_control_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        peer_conn
+            .stream_stop_sending(SERVER_SIDE_CONTROL_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: Test that the connection will be closed if the server side encoder stream
+    // has received a stop_sending.
+    #[test]
+    fn test_server_stop_sending_encoder_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        peer_conn
+            .stream_stop_sending(SERVER_SIDE_ENCODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    // Server: Test that the connection will be closed if the server side decoder stream
+    // has received a stop_sending.
+    #[test]
+    fn test_server_stop_sending_decoder_stream() {
+        let (mut hconn, mut peer_conn) = connect();
+        peer_conn
+            .stream_stop_sending(SERVER_SIDE_DECODER_STREAM_ID, Error::HttpNoError.code())
+            .unwrap();
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+        assert_closed(&mut hconn, &Error::HttpClosedCriticalStream);
+    }
+
+    /// Perform a handshake, then another with the token from the first.
+    /// The second should always resume, but it might not always accept early data.
+    fn zero_rtt_with_settings(conn_params: Http3Parameters, zero_rtt: ZeroRttState) {
+        let (_, mut client) = connect();
+        let token = client.events().find_map(|e| {
+            if let ConnectionEvent::ResumptionToken(token) = e {
+                Some(token)
+            } else {
+                None
+            }
+        });
+        assert!(token.is_some());
+
+        let mut server = create_server(conn_params);
+        let mut client = default_client();
+        client.enable_resumption(now(), token.unwrap()).unwrap();
+
+        connect_transport(&mut server, &mut client, true);
+        assert!(client.tls_info().unwrap().resumed());
+        assert_eq!(client.zero_rtt_state(), zero_rtt);
+    }
+
+    #[test]
+    fn zero_rtt() {
+        zero_rtt_with_settings(http3params(DEFAULT_SETTINGS), ZeroRttState::AcceptedClient);
+    }
+
+    /// A larger QPACK decoder table size isn't an impediment to 0-RTT.
+    #[test]
+    fn zero_rtt_larger_decoder_table() {
+        zero_rtt_with_settings(
+            http3params(QpackSettings {
+                max_table_size_decoder: DEFAULT_SETTINGS.max_table_size_decoder + 1,
+                ..DEFAULT_SETTINGS
+            }),
+            ZeroRttState::AcceptedClient,
+        );
+    }
+
+    /// A smaller QPACK decoder table size prevents 0-RTT.
+    #[test]
+    fn zero_rtt_smaller_decoder_table() {
+        zero_rtt_with_settings(
+            http3params(QpackSettings {
+                max_table_size_decoder: DEFAULT_SETTINGS.max_table_size_decoder - 1,
+                ..DEFAULT_SETTINGS
+            }),
+            ZeroRttState::Rejected,
+        );
+    }
+
+    /// More blocked streams does not prevent 0-RTT.
+    #[test]
+    fn zero_rtt_more_blocked_streams() {
+        zero_rtt_with_settings(
+            http3params(QpackSettings {
+                max_blocked_streams: DEFAULT_SETTINGS.max_blocked_streams + 1,
+                ..DEFAULT_SETTINGS
+            }),
+            ZeroRttState::AcceptedClient,
+        );
+    }
+
+    /// A lower number of blocked streams also prevents 0-RTT.
+    #[test]
+    fn zero_rtt_fewer_blocked_streams() {
+        zero_rtt_with_settings(
+            http3params(QpackSettings {
+                max_blocked_streams: DEFAULT_SETTINGS.max_blocked_streams - 1,
+                ..DEFAULT_SETTINGS
+            }),
+            ZeroRttState::Rejected,
+        );
+    }
+
+    /// The size of the encoder table is local and therefore doesn't prevent 0-RTT.
+    #[test]
+    fn zero_rtt_smaller_encoder_table() {
+        zero_rtt_with_settings(
+            http3params(QpackSettings {
+                max_table_size_encoder: DEFAULT_SETTINGS.max_table_size_encoder - 1,
+                ..DEFAULT_SETTINGS
+            }),
+            ZeroRttState::AcceptedClient,
+        );
+    }
+
+    #[test]
+    fn client_request_hash() {
+        let (mut hconn, mut peer_conn) = connect();
+
+        let request_stream_id_1 = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        // Send only request headers for now.
+        peer_conn
+            .stream_send(request_stream_id_1, REQUEST_WITH_BODY)
+            .unwrap();
+
+        let request_stream_id_2 = peer_conn.stream_create(StreamType::BiDi).unwrap();
+        // Send only request headers for now.
+        peer_conn
+            .stream_send(request_stream_id_2, REQUEST_WITH_BODY)
+            .unwrap();
+
+        let out = peer_conn.process(None, now());
+        hconn.process(out.as_dgram_ref(), now());
+
+        let mut requests = HashMap::new();
+        while let Some(event) = hconn.next_event() {
+            match event {
+                Http3ServerEvent::Headers { stream, .. } => {
+                    assert!(requests.get(&stream).is_none());
+                    requests.insert(stream, 0);
+                }
+                Http3ServerEvent::Data { stream, .. } => {
+                    assert!(requests.get(&stream).is_some());
+                }
+                Http3ServerEvent::DataWritable { .. }
+                | Http3ServerEvent::StreamReset { .. }
+                | Http3ServerEvent::StreamStopSending { .. }
+                | Http3ServerEvent::StateChange { .. }
+                | Http3ServerEvent::PriorityUpdate { .. }
+                | Http3ServerEvent::WebTransport(_) => {}
+            }
+        }
+        assert_eq!(requests.len(), 2);
+    }
+
+    #[derive(Debug, Default)]
+    pub struct RejectZeroRtt {}
+    impl ZeroRttChecker for RejectZeroRtt {
+        fn check(&self, _token: &[u8]) -> ZeroRttCheckResult {
+            ZeroRttCheckResult::Reject
+        }
+    }
+
+    #[test]
+    fn reject_zero_server() {
+        fixture_init();
+        let mut server = Http3Server::new(
+            now(),
+            DEFAULT_KEYS,
+            DEFAULT_ALPN,
+            anti_replay(),
+            Rc::new(RefCell::new(CountingConnectionIdGenerator::default())),
+            http3params(DEFAULT_SETTINGS),
+            Some(Box::<RejectZeroRtt>::default()),
+        )
+        .expect("create a server");
+        let mut client = connect_to(&mut server);
+        let token = client.events().find_map(|e| {
+            if let ConnectionEvent::ResumptionToken(token) = e {
+                Some(token)
+            } else {
+                None
+            }
+        });
+        assert!(token.is_some());
+
+        let mut client = default_client();
+        client.enable_resumption(now(), token.unwrap()).unwrap();
+
+        connect_transport(&mut server, &mut client, true);
+        assert!(client.tls_info().unwrap().resumed());
+        assert_eq!(client.zero_rtt_state(), ZeroRttState::Rejected);
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/server_connection_events.rs b/third_party/rust/neqo-http3/src/server_connection_events.rs
new file mode 100644
index 0000000000..cbc8e6d56e
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/server_connection_events.rs
@@ -0,0 +1,196 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::{cell::RefCell, collections::VecDeque, rc::Rc};
+
+use neqo_common::Header;
+use neqo_transport::{AppError, StreamId};
+
+use crate::{
+    connection::Http3State,
+    features::extended_connect::{ExtendedConnectEvents, ExtendedConnectType, SessionCloseReason},
+    CloseType, Http3StreamInfo, HttpRecvStreamEvents, Priority, RecvStreamEvents, SendStreamEvents,
+};
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub(crate) enum Http3ServerConnEvent {
+    /// Headers are ready.
+    Headers {
+        stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        fin: bool,
+    },
+    PriorityUpdate {
+        stream_id: StreamId,
+        priority: Priority,
+    },
+    /// Request data is ready.
+    DataReadable {
+        stream_info: Http3StreamInfo,
+    },
+    DataWritable {
+        stream_info: Http3StreamInfo,
+    },
+    StreamReset {
+        stream_info: Http3StreamInfo,
+        error: AppError,
+    },
+    StreamStopSending {
+        stream_info: Http3StreamInfo,
+        error: AppError,
+    },
+    /// Connection state change.
+    StateChange(Http3State),
+    ExtendedConnect {
+        stream_id: StreamId,
+        headers: Vec<Header>,
+    },
+    ExtendedConnectClosed {
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    },
+    ExtendedConnectNewStream(Http3StreamInfo),
+    ExtendedConnectDatagram {
+        session_id: StreamId,
+        datagram: Vec<u8>,
+    },
+}
+
+#[derive(Debug, Default, Clone)]
+pub(crate) struct Http3ServerConnEvents {
+    events: Rc<RefCell<VecDeque<Http3ServerConnEvent>>>,
+}
+
+impl SendStreamEvents for Http3ServerConnEvents {
+    fn send_closed(&self, stream_info: Http3StreamInfo, close_type: CloseType) {
+        if close_type != CloseType::Done {
+            self.insert(Http3ServerConnEvent::StreamStopSending {
+                stream_info,
+                error: close_type.error().unwrap(),
+            });
+        }
+    }
+
+    fn data_writable(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ServerConnEvent::DataWritable { stream_info });
+    }
+}
+
+impl RecvStreamEvents for Http3ServerConnEvents {
+    /// Add a new `DataReadable` event
+    fn data_readable(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ServerConnEvent::DataReadable { stream_info });
+    }
+
+    fn recv_closed(&self, stream_info: Http3StreamInfo, close_type: CloseType) {
+        if close_type != CloseType::Done {
+            self.remove_events_for_stream_id(stream_info);
+            self.insert(Http3ServerConnEvent::StreamReset {
+                stream_info,
+                error: close_type.error().unwrap(),
+            });
+        }
+    }
+}
+
+impl HttpRecvStreamEvents for Http3ServerConnEvents {
+    /// Add a new `HeaderReady` event.
+    fn header_ready(
+        &self,
+        stream_info: Http3StreamInfo,
+        headers: Vec<Header>,
+        _interim: bool,
+        fin: bool,
+    ) {
+        self.insert(Http3ServerConnEvent::Headers {
+            stream_info,
+            headers,
+            fin,
+        });
+    }
+
+    fn extended_connect_new_session(&self, stream_id: StreamId, headers: Vec<Header>) {
+        self.insert(Http3ServerConnEvent::ExtendedConnect { stream_id, headers });
+    }
+}
+
+impl ExtendedConnectEvents for Http3ServerConnEvents {
+    fn session_start(
+        &self,
+        _connect_type: ExtendedConnectType,
+        _stream_id: StreamId,
+        _status: u16,
+        _headers: Vec<Header>,
+    ) {
+    }
+
+    fn session_end(
+        &self,
+        connect_type: ExtendedConnectType,
+        stream_id: StreamId,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    ) {
+        self.insert(Http3ServerConnEvent::ExtendedConnectClosed {
+            connect_type,
+            stream_id,
+            reason,
+            headers,
+        });
+    }
+
+    fn extended_connect_new_stream(&self, stream_info: Http3StreamInfo) {
+        self.insert(Http3ServerConnEvent::ExtendedConnectNewStream(stream_info));
+    }
+
+    fn new_datagram(&self, session_id: StreamId, datagram: Vec<u8>) {
+        self.insert(Http3ServerConnEvent::ExtendedConnectDatagram {
+            session_id,
+            datagram,
+        });
+    }
+}
+
+impl Http3ServerConnEvents {
+    fn insert(&self, event: Http3ServerConnEvent) {
+        self.events.borrow_mut().push_back(event);
+    }
+
+    fn remove<F>(&self, f: F)
+    where
+        F: Fn(&Http3ServerConnEvent) -> bool,
+    {
+        self.events.borrow_mut().retain(|evt| !f(evt));
+    }
+
+    pub fn has_events(&self) -> bool {
+        !self.events.borrow().is_empty()
+    }
+
+    pub fn next_event(&self) -> Option<Http3ServerConnEvent> {
+        self.events.borrow_mut().pop_front()
+    }
+
+    pub fn connection_state_change(&self, state: Http3State) {
+        self.insert(Http3ServerConnEvent::StateChange(state));
+    }
+
+    pub fn priority_update(&self, stream_id: StreamId, priority: Priority) {
+        self.insert(Http3ServerConnEvent::PriorityUpdate {
+            stream_id,
+            priority,
+        });
+    }
+
+    fn remove_events_for_stream_id(&self, stream_info: Http3StreamInfo) {
+        self.remove(|evt| {
+            matches!(evt,
+                Http3ServerConnEvent::Headers { stream_info: x, .. } | Http3ServerConnEvent::DataReadable { stream_info: x, .. } if *x == stream_info)
+        });
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/server_events.rs b/third_party/rust/neqo-http3/src/server_events.rs
new file mode 100644
index 0000000000..4be48363df
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/server_events.rs
@@ -0,0 +1,601 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::{
+    cell::RefCell,
+    collections::VecDeque,
+    convert::TryFrom,
+    ops::{Deref, DerefMut},
+    rc::Rc,
+};
+
+use neqo_common::{qdebug, qinfo, Encoder, Header};
+use neqo_transport::{
+    server::ActiveConnectionRef, AppError, Connection, DatagramTracking, StreamId, StreamType,
+};
+
+use crate::{
+    connection::{Http3State, WebTransportSessionAcceptAction},
+    connection_server::Http3ServerHandler,
+    features::extended_connect::SessionCloseReason,
+    Http3StreamInfo, Http3StreamType, Priority, Res,
+};
+
+#[derive(Debug, Clone)]
+pub struct StreamHandler {
+    pub conn: ActiveConnectionRef,
+    pub handler: Rc<RefCell<Http3ServerHandler>>,
+    pub stream_info: Http3StreamInfo,
+}
+
+impl ::std::fmt::Display for StreamHandler {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        let conn: &Connection = &self.conn.borrow();
+        write!(f, "conn={} stream_info={:?}", conn, self.stream_info)
+    }
+}
+
+impl std::hash::Hash for StreamHandler {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.conn.hash(state);
+        state.write_u64(self.stream_info.stream_id().as_u64());
+        state.finish();
+    }
+}
+
+impl PartialEq for StreamHandler {
+    fn eq(&self, other: &Self) -> bool {
+        self.conn == other.conn && self.stream_info.stream_id() == other.stream_info.stream_id()
+    }
+}
+
+impl Eq for StreamHandler {}
+
+impl StreamHandler {
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_info.stream_id()
+    }
+
+    /// Supply a response header to a request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn send_headers(&mut self, headers: &[Header]) -> Res<()> {
+        self.handler.borrow_mut().send_headers(
+            self.stream_id(),
+            headers,
+            &mut self.conn.borrow_mut(),
+        )
+    }
+
+    /// Supply response data to a request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn send_data(&mut self, buf: &[u8]) -> Res<usize> {
+        self.handler
+            .borrow_mut()
+            .send_data(self.stream_id(), buf, &mut self.conn.borrow_mut())
+    }
+
+    /// Close sending side.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn stream_close_send(&mut self) -> Res<()> {
+        self.handler
+            .borrow_mut()
+            .stream_close_send(self.stream_id(), &mut self.conn.borrow_mut())
+    }
+
+    /// Request a peer to stop sending a stream.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn stream_stop_sending(&mut self, app_error: AppError) -> Res<()> {
+        qdebug!(
+            [self],
+            "stop sending stream_id:{} error:{}.",
+            self.stream_info.stream_id(),
+            app_error
+        );
+        self.handler.borrow_mut().stream_stop_sending(
+            self.stream_info.stream_id(),
+            app_error,
+            &mut self.conn.borrow_mut(),
+        )
+    }
+
+    /// Reset sending side of a stream.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn stream_reset_send(&mut self, app_error: AppError) -> Res<()> {
+        qdebug!(
+            [self],
+            "reset send stream_id:{} error:{}.",
+            self.stream_info.stream_id(),
+            app_error
+        );
+        self.handler.borrow_mut().stream_reset_send(
+            self.stream_info.stream_id(),
+            app_error,
+            &mut self.conn.borrow_mut(),
+        )
+    }
+
+    /// Reset a stream/request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore
+    pub fn cancel_fetch(&mut self, app_error: AppError) -> Res<()> {
+        qdebug!([self], "reset error:{}.", app_error);
+        self.handler.borrow_mut().cancel_fetch(
+            self.stream_info.stream_id(),
+            app_error,
+            &mut self.conn.borrow_mut(),
+        )
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Http3OrWebTransportStream {
+    stream_handler: StreamHandler,
+}
+
+impl ::std::fmt::Display for Http3OrWebTransportStream {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "Stream server {:?}", self.stream_handler)
+    }
+}
+
+impl Http3OrWebTransportStream {
+    pub(crate) fn new(
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_info: Http3StreamInfo,
+    ) -> Self {
+        Self {
+            stream_handler: StreamHandler {
+                conn,
+                handler,
+                stream_info,
+            },
+        }
+    }
+
+    /// Supply a response header to a request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn send_headers(&mut self, headers: &[Header]) -> Res<()> {
+        self.stream_handler.send_headers(headers)
+    }
+
+    /// Supply response data to a request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn send_data(&mut self, data: &[u8]) -> Res<usize> {
+        qinfo!([self], "Set new response.");
+        self.stream_handler.send_data(data)
+    }
+
+    /// Close sending side.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn stream_close_send(&mut self) -> Res<()> {
+        qinfo!([self], "Set new response.");
+        self.stream_handler.stream_close_send()
+    }
+}
+
+impl Deref for Http3OrWebTransportStream {
+    type Target = StreamHandler;
+    #[must_use]
+    fn deref(&self) -> &Self::Target {
+        &self.stream_handler
+    }
+}
+
+impl DerefMut for Http3OrWebTransportStream {
+    fn deref_mut(&mut self) -> &mut StreamHandler {
+        &mut self.stream_handler
+    }
+}
+
+impl std::hash::Hash for Http3OrWebTransportStream {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.stream_handler.hash(state);
+        state.finish();
+    }
+}
+
+impl PartialEq for Http3OrWebTransportStream {
+    fn eq(&self, other: &Self) -> bool {
+        self.stream_handler == other.stream_handler
+    }
+}
+
+impl Eq for Http3OrWebTransportStream {}
+
+#[derive(Debug, Clone)]
+pub struct WebTransportRequest {
+    stream_handler: StreamHandler,
+}
+
+impl ::std::fmt::Display for WebTransportRequest {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "WebTransport session {}", self.stream_handler)
+    }
+}
+
+impl WebTransportRequest {
+    pub(crate) fn new(
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_id: StreamId,
+    ) -> Self {
+        Self {
+            stream_handler: StreamHandler {
+                conn,
+                handler,
+                stream_info: Http3StreamInfo::new(stream_id, Http3StreamType::Http),
+            },
+        }
+    }
+
+    #[must_use]
+    pub fn state(&self) -> Http3State {
+        self.stream_handler.handler.borrow().state()
+    }
+
+    /// Respond to a `WebTransport` session request.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn response(&mut self, accept: &WebTransportSessionAcceptAction) -> Res<()> {
+        qinfo!([self], "Set a response for a WebTransport session.");
+        self.stream_handler
+            .handler
+            .borrow_mut()
+            .webtransport_session_accept(
+                &mut self.stream_handler.conn.borrow_mut(),
+                self.stream_handler.stream_info.stream_id(),
+                accept,
+            )
+    }
+
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    /// Also return an error if the stream was closed on the transport layer,
+    /// but that information is not yet consumed on the  http/3 layer.
+    pub fn close_session(&mut self, error: u32, message: &str) -> Res<()> {
+        self.stream_handler
+            .handler
+            .borrow_mut()
+            .webtransport_close_session(
+                &mut self.stream_handler.conn.borrow_mut(),
+                self.stream_handler.stream_info.stream_id(),
+                error,
+                message,
+            )
+    }
+
+    #[must_use]
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_handler.stream_id()
+    }
+
+    /// Close sending side.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    pub fn create_stream(&mut self, stream_type: StreamType) -> Res<Http3OrWebTransportStream> {
+        let session_id = self.stream_handler.stream_id();
+        let id = self
+            .stream_handler
+            .handler
+            .borrow_mut()
+            .webtransport_create_stream(
+                &mut self.stream_handler.conn.borrow_mut(),
+                session_id,
+                stream_type,
+            )?;
+
+        Ok(Http3OrWebTransportStream::new(
+            self.stream_handler.conn.clone(),
+            self.stream_handler.handler.clone(),
+            Http3StreamInfo::new(id, Http3StreamType::WebTransport(session_id)),
+        ))
+    }
+
+    /// Send `WebTransport` datagram.
+    ///
+    /// # Errors
+    ///
+    /// It may return `InvalidStreamId` if a stream does not exist anymore.
+    /// The function returns `TooMuchData` if the supply buffer is bigger than
+    /// the allowed remote datagram size.
+    pub fn send_datagram(&mut self, buf: &[u8], id: impl Into<DatagramTracking>) -> Res<()> {
+        let session_id = self.stream_handler.stream_id();
+        self.stream_handler
+            .handler
+            .borrow_mut()
+            .webtransport_send_datagram(
+                &mut self.stream_handler.conn.borrow_mut(),
+                session_id,
+                buf,
+                id,
+            )
+    }
+
+    #[must_use]
+    pub fn remote_datagram_size(&self) -> u64 {
+        self.stream_handler.conn.borrow().remote_datagram_size()
+    }
+
+    /// Returns the current max size of a datagram that can fit into a packet.
+    /// The value will change over time depending on the encoded size of the
+    /// packet number, ack frames, etc.
+    ///
+    /// # Errors
+    ///
+    /// The function returns `NotAvailable` if datagrams are not enabled.
+    ///
+    /// # Panics
+    ///
+    /// This cannot panic. The max varint length is 8.
+    pub fn max_datagram_size(&self) -> Res<u64> {
+        let max_size = self.stream_handler.conn.borrow().max_datagram_size()?;
+        Ok(max_size
+            - u64::try_from(Encoder::varint_len(
+                self.stream_handler.stream_id().as_u64(),
+            ))
+            .unwrap())
+    }
+}
+
+impl Deref for WebTransportRequest {
+    type Target = StreamHandler;
+    #[must_use]
+    fn deref(&self) -> &Self::Target {
+        &self.stream_handler
+    }
+}
+
+impl DerefMut for WebTransportRequest {
+    fn deref_mut(&mut self) -> &mut StreamHandler {
+        &mut self.stream_handler
+    }
+}
+
+impl std::hash::Hash for WebTransportRequest {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.stream_handler.hash(state);
+        state.finish();
+    }
+}
+
+impl PartialEq for WebTransportRequest {
+    fn eq(&self, other: &Self) -> bool {
+        self.stream_handler == other.stream_handler
+    }
+}
+
+impl Eq for WebTransportRequest {}
+
+#[derive(Debug, Clone)]
+pub enum WebTransportServerEvent {
+    NewSession {
+        session: WebTransportRequest,
+        headers: Vec<Header>,
+    },
+    SessionClosed {
+        session: WebTransportRequest,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    },
+    NewStream(Http3OrWebTransportStream),
+    Datagram {
+        session: WebTransportRequest,
+        datagram: Vec<u8>,
+    },
+}
+
+#[derive(Debug, Clone)]
+pub enum Http3ServerEvent {
+    /// Headers are ready.
+    Headers {
+        stream: Http3OrWebTransportStream,
+        headers: Vec<Header>,
+        fin: bool,
+    },
+    /// Request data is ready.
+    Data {
+        stream: Http3OrWebTransportStream,
+        data: Vec<u8>,
+        fin: bool,
+    },
+    DataWritable {
+        stream: Http3OrWebTransportStream,
+    },
+    StreamReset {
+        stream: Http3OrWebTransportStream,
+        error: AppError,
+    },
+    StreamStopSending {
+        stream: Http3OrWebTransportStream,
+        error: AppError,
+    },
+    /// When individual connection change state. It is only used for tests.
+    StateChange {
+        conn: ActiveConnectionRef,
+        state: Http3State,
+    },
+    PriorityUpdate {
+        stream_id: StreamId,
+        priority: Priority,
+    },
+    WebTransport(WebTransportServerEvent),
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct Http3ServerEvents {
+    events: Rc<RefCell<VecDeque<Http3ServerEvent>>>,
+}
+
+impl Http3ServerEvents {
+    fn insert(&self, event: Http3ServerEvent) {
+        self.events.borrow_mut().push_back(event);
+    }
+
+    /// Take all events
+    pub fn events(&self) -> impl Iterator<Item = Http3ServerEvent> {
+        self.events.replace(VecDeque::new()).into_iter()
+    }
+
+    /// Whether there is request pending.
+    pub fn has_events(&self) -> bool {
+        !self.events.borrow().is_empty()
+    }
+
+    /// Take the next event if present.
+    pub fn next_event(&self) -> Option<Http3ServerEvent> {
+        self.events.borrow_mut().pop_front()
+    }
+
+    /// Insert a `Headers` event.
+    pub(crate) fn headers(
+        &self,
+        request: Http3OrWebTransportStream,
+        headers: Vec<Header>,
+        fin: bool,
+    ) {
+        self.insert(Http3ServerEvent::Headers {
+            stream: request,
+            headers,
+            fin,
+        });
+    }
+
+    /// Insert a `StateChange` event.
+    pub(crate) fn connection_state_change(&self, conn: ActiveConnectionRef, state: Http3State) {
+        self.insert(Http3ServerEvent::StateChange { conn, state });
+    }
+
+    /// Insert a `Data` event.
+    pub(crate) fn data(
+        &self,
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_info: Http3StreamInfo,
+        data: Vec<u8>,
+        fin: bool,
+    ) {
+        self.insert(Http3ServerEvent::Data {
+            stream: Http3OrWebTransportStream::new(conn, handler, stream_info),
+            data,
+            fin,
+        });
+    }
+
+    pub(crate) fn data_writable(
+        &self,
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_info: Http3StreamInfo,
+    ) {
+        self.insert(Http3ServerEvent::DataWritable {
+            stream: Http3OrWebTransportStream::new(conn, handler, stream_info),
+        });
+    }
+
+    pub(crate) fn stream_reset(
+        &self,
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_info: Http3StreamInfo,
+        error: AppError,
+    ) {
+        self.insert(Http3ServerEvent::StreamReset {
+            stream: Http3OrWebTransportStream::new(conn, handler, stream_info),
+            error,
+        });
+    }
+
+    pub(crate) fn stream_stop_sending(
+        &self,
+        conn: ActiveConnectionRef,
+        handler: Rc<RefCell<Http3ServerHandler>>,
+        stream_info: Http3StreamInfo,
+        error: AppError,
+    ) {
+        self.insert(Http3ServerEvent::StreamStopSending {
+            stream: Http3OrWebTransportStream::new(conn, handler, stream_info),
+            error,
+        });
+    }
+
+    pub(crate) fn priority_update(&self, stream_id: StreamId, priority: Priority) {
+        self.insert(Http3ServerEvent::PriorityUpdate {
+            stream_id,
+            priority,
+        });
+    }
+
+    pub(crate) fn webtransport_new_session(
+        &self,
+        session: WebTransportRequest,
+        headers: Vec<Header>,
+    ) {
+        self.insert(Http3ServerEvent::WebTransport(
+            WebTransportServerEvent::NewSession { session, headers },
+        ));
+    }
+
+    pub(crate) fn webtransport_session_closed(
+        &self,
+        session: WebTransportRequest,
+        reason: SessionCloseReason,
+        headers: Option<Vec<Header>>,
+    ) {
+        self.insert(Http3ServerEvent::WebTransport(
+            WebTransportServerEvent::SessionClosed {
+                session,
+                reason,
+                headers,
+            },
+        ));
+    }
+
+    pub(crate) fn webtransport_new_stream(&self, stream: Http3OrWebTransportStream) {
+        self.insert(Http3ServerEvent::WebTransport(
+            WebTransportServerEvent::NewStream(stream),
+        ));
+    }
+
+    pub(crate) fn webtransport_datagram(&self, session: WebTransportRequest, datagram: Vec<u8>) {
+        self.insert(Http3ServerEvent::WebTransport(
+            WebTransportServerEvent::Datagram { session, datagram },
+        ));
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/settings.rs b/third_party/rust/neqo-http3/src/settings.rs
new file mode 100644
index 0000000000..9cd4b994b7
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/settings.rs
@@ -0,0 +1,299 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use std::ops::Deref;
+
+use neqo_common::{Decoder, Encoder};
+use neqo_crypto::{ZeroRttCheckResult, ZeroRttChecker};
+
+use crate::{Error, Http3Parameters, Res};
+
+type SettingsType = u64;
+
+/// Increment this version number if a new setting is added and that might
+/// cause 0-RTT to be accepted where shouldn't be.
+const SETTINGS_ZERO_RTT_VERSION: u64 = 1;
+
+const SETTINGS_MAX_HEADER_LIST_SIZE: SettingsType = 0x6;
+const SETTINGS_QPACK_MAX_TABLE_CAPACITY: SettingsType = 0x1;
+const SETTINGS_QPACK_BLOCKED_STREAMS: SettingsType = 0x7;
+const SETTINGS_ENABLE_WEB_TRANSPORT: SettingsType = 0x2b60_3742;
+// draft-ietf-masque-h3-datagram-04.
+// We also use this old value because the current web-platform test only supports
+// this value.
+const SETTINGS_H3_DATAGRAM_DRAFT04: SettingsType = 0x00ff_d277;
+
+const SETTINGS_H3_DATAGRAM: SettingsType = 0x33;
+
+pub const H3_RESERVED_SETTINGS: &[SettingsType] = &[0x2, 0x3, 0x4, 0x5];
+
+#[derive(Clone, PartialEq, Eq, Debug, Copy)]
+pub enum HSettingType {
+    MaxHeaderListSize,
+    MaxTableCapacity,
+    BlockedStreams,
+    EnableWebTransport,
+    EnableH3Datagram,
+}
+
+fn hsetting_default(setting_type: HSettingType) -> u64 {
+    match setting_type {
+        HSettingType::MaxHeaderListSize => 1 << 62,
+        HSettingType::MaxTableCapacity
+        | HSettingType::BlockedStreams
+        | HSettingType::EnableWebTransport
+        | HSettingType::EnableH3Datagram => 0,
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct HSetting {
+    pub setting_type: HSettingType,
+    pub value: u64,
+}
+
+impl HSetting {
+    #[must_use]
+    pub fn new(setting_type: HSettingType, value: u64) -> Self {
+        Self {
+            setting_type,
+            value,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct HSettings {
+    settings: Vec<HSetting>,
+}
+
+impl HSettings {
+    #[must_use]
+    pub fn new(settings: &[HSetting]) -> Self {
+        Self {
+            settings: settings.to_vec(),
+        }
+    }
+
+    #[must_use]
+    pub fn get(&self, setting: HSettingType) -> u64 {
+        match self.settings.iter().find(|s| s.setting_type == setting) {
+            Some(v) => v.value,
+            None => hsetting_default(setting),
+        }
+    }
+
+    pub fn encode_frame_contents(&self, enc: &mut Encoder) {
+        enc.encode_vvec_with(|enc_inner| {
+            for iter in &self.settings {
+                match iter.setting_type {
+                    HSettingType::MaxHeaderListSize => {
+                        enc_inner.encode_varint(SETTINGS_MAX_HEADER_LIST_SIZE);
+                        enc_inner.encode_varint(iter.value);
+                    }
+                    HSettingType::MaxTableCapacity => {
+                        enc_inner.encode_varint(SETTINGS_QPACK_MAX_TABLE_CAPACITY);
+                        enc_inner.encode_varint(iter.value);
+                    }
+                    HSettingType::BlockedStreams => {
+                        enc_inner.encode_varint(SETTINGS_QPACK_BLOCKED_STREAMS);
+                        enc_inner.encode_varint(iter.value);
+                    }
+                    HSettingType::EnableWebTransport => {
+                        enc_inner.encode_varint(SETTINGS_ENABLE_WEB_TRANSPORT);
+                        enc_inner.encode_varint(iter.value);
+                    }
+                    HSettingType::EnableH3Datagram => {
+                        if iter.value == 1 {
+                            enc_inner.encode_varint(SETTINGS_H3_DATAGRAM_DRAFT04);
+                            enc_inner.encode_varint(iter.value);
+                            enc_inner.encode_varint(SETTINGS_H3_DATAGRAM);
+                            enc_inner.encode_varint(iter.value);
+                        }
+                    }
+                }
+            }
+        });
+    }
+
+    /// # Errors
+    ///
+    /// Returns an error if settings types are reserved of settings value are not permitted.
+    pub fn decode_frame_contents(&mut self, dec: &mut Decoder) -> Res<()> {
+        while dec.remaining() > 0 {
+            let t = dec.decode_varint();
+            let v = dec.decode_varint();
+
+            if let Some(settings_type) = t {
+                if H3_RESERVED_SETTINGS.contains(&settings_type) {
+                    return Err(Error::HttpSettings);
+                }
+            }
+            match (t, v) {
+                (Some(SETTINGS_MAX_HEADER_LIST_SIZE), Some(value)) => self
+                    .settings
+                    .push(HSetting::new(HSettingType::MaxHeaderListSize, value)),
+                (Some(SETTINGS_QPACK_MAX_TABLE_CAPACITY), Some(value)) => self
+                    .settings
+                    .push(HSetting::new(HSettingType::MaxTableCapacity, value)),
+                (Some(SETTINGS_QPACK_BLOCKED_STREAMS), Some(value)) => self
+                    .settings
+                    .push(HSetting::new(HSettingType::BlockedStreams, value)),
+                (Some(SETTINGS_ENABLE_WEB_TRANSPORT), Some(value)) => {
+                    if value > 1 {
+                        return Err(Error::HttpSettings);
+                    }
+                    self.settings
+                        .push(HSetting::new(HSettingType::EnableWebTransport, value));
+                }
+                (Some(SETTINGS_H3_DATAGRAM_DRAFT04), Some(value)) => {
+                    if value > 1 {
+                        return Err(Error::HttpSettings);
+                    }
+                    if !self
+                        .settings
+                        .iter()
+                        .any(|s| s.setting_type == HSettingType::EnableH3Datagram)
+                    {
+                        self.settings
+                            .push(HSetting::new(HSettingType::EnableH3Datagram, value));
+                    }
+                }
+                (Some(SETTINGS_H3_DATAGRAM), Some(value)) => {
+                    if value > 1 {
+                        return Err(Error::HttpSettings);
+                    }
+                    if !self
+                        .settings
+                        .iter()
+                        .any(|s| s.setting_type == HSettingType::EnableH3Datagram)
+                    {
+                        self.settings
+                            .push(HSetting::new(HSettingType::EnableH3Datagram, value));
+                    }
+                }
+                // other supported settings here
+                (Some(_), Some(_)) => {} // ignore unknown setting, it is fine.
+                _ => return Err(Error::NotEnoughData),
+            };
+        }
+        Ok(())
+    }
+}
+
+impl Deref for HSettings {
+    type Target = [HSetting];
+    fn deref(&self) -> &Self::Target {
+        &self.settings
+    }
+}
+
+impl From<&Http3Parameters> for HSettings {
+    fn from(conn_param: &Http3Parameters) -> Self {
+        Self {
+            settings: vec![
+                HSetting {
+                    setting_type: HSettingType::MaxTableCapacity,
+                    value: conn_param.get_max_table_size_decoder(),
+                },
+                HSetting {
+                    setting_type: HSettingType::BlockedStreams,
+                    value: u64::from(conn_param.get_max_blocked_streams()),
+                },
+                HSetting {
+                    setting_type: HSettingType::EnableWebTransport,
+                    value: u64::from(conn_param.get_webtransport()),
+                },
+                HSetting {
+                    setting_type: HSettingType::EnableH3Datagram,
+                    value: u64::from(conn_param.get_http3_datagram()),
+                },
+            ],
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct HttpZeroRttChecker {
+    settings: Http3Parameters,
+}
+
+impl HttpZeroRttChecker {
+    /// Right now we only have QPACK settings, so that is all this takes.
+    #[must_use]
+    pub fn new(settings: Http3Parameters) -> Self {
+        Self { settings }
+    }
+
+    /// Save the settings that matter for 0-RTT.
+    #[must_use]
+    pub fn save(settings: &Http3Parameters) -> Vec<u8> {
+        let mut enc = Encoder::new();
+        enc.encode_varint(SETTINGS_ZERO_RTT_VERSION)
+            .encode_varint(SETTINGS_QPACK_MAX_TABLE_CAPACITY)
+            .encode_varint(settings.get_max_table_size_decoder())
+            .encode_varint(SETTINGS_QPACK_BLOCKED_STREAMS)
+            .encode_varint(settings.get_max_blocked_streams());
+        if settings.get_webtransport() {
+            enc.encode_varint(SETTINGS_ENABLE_WEB_TRANSPORT)
+                .encode_varint(true);
+        }
+        if settings.get_http3_datagram() {
+            enc.encode_varint(SETTINGS_H3_DATAGRAM).encode_varint(true);
+        }
+        enc.into()
+    }
+}
+
+impl ZeroRttChecker for HttpZeroRttChecker {
+    fn check(&self, token: &[u8]) -> ZeroRttCheckResult {
+        let mut dec = Decoder::from(token);
+
+        // Read and check the version.
+        if let Some(version) = dec.decode_varint() {
+            if version != SETTINGS_ZERO_RTT_VERSION {
+                return ZeroRttCheckResult::Reject;
+            }
+        } else {
+            return ZeroRttCheckResult::Fail;
+        }
+
+        // Now treat the rest as a settings frame.
+        let mut settings = HSettings::new(&[]);
+        if settings.decode_frame_contents(&mut dec).is_err() {
+            return ZeroRttCheckResult::Fail;
+        }
+        if settings.iter().all(|setting| match setting.setting_type {
+            HSettingType::BlockedStreams => {
+                u64::from(self.settings.get_max_blocked_streams()) >= setting.value
+            }
+            HSettingType::MaxTableCapacity => {
+                self.settings.get_max_table_size_decoder() >= setting.value
+            }
+            HSettingType::EnableWebTransport => {
+                if setting.value > 1 {
+                    return false;
+                }
+                let value = setting.value == 1;
+                self.settings.get_webtransport() || !value
+            }
+            HSettingType::EnableH3Datagram => {
+                if setting.value > 1 {
+                    return false;
+                }
+                let value = setting.value == 1;
+                self.settings.get_http3_datagram() || !value
+            }
+            HSettingType::MaxHeaderListSize => true,
+        }) {
+            ZeroRttCheckResult::Accept
+        } else {
+            ZeroRttCheckResult::Reject
+        }
+    }
+}
diff --git a/third_party/rust/neqo-http3/src/stream_type_reader.rs b/third_party/rust/neqo-http3/src/stream_type_reader.rs
new file mode 100644
index 0000000000..f36181d3b1
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/stream_type_reader.rs
@@ -0,0 +1,687 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(clippy::module_name_repetitions)]
+
+use neqo_common::{qtrace, Decoder, IncrementalDecoderUint, Role};
+use neqo_qpack::{decoder::QPACK_UNI_STREAM_TYPE_DECODER, encoder::QPACK_UNI_STREAM_TYPE_ENCODER};
+use neqo_transport::{Connection, StreamId, StreamType};
+
+use crate::{
+    control_stream_local::HTTP3_UNI_STREAM_TYPE_CONTROL, frames::H3_FRAME_TYPE_HEADERS, CloseType,
+    Error, Http3StreamType, ReceiveOutput, RecvStream, Res, Stream,
+};
+
+pub(crate) const HTTP3_UNI_STREAM_TYPE_PUSH: u64 = 0x1;
+pub(crate) const WEBTRANSPORT_UNI_STREAM: u64 = 0x54;
+pub(crate) const WEBTRANSPORT_STREAM: u64 = 0x41;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) enum NewStreamType {
+    Control,
+    Decoder,
+    Encoder,
+    Push(u64),
+    WebTransportStream(u64),
+    Http,
+    Unknown,
+}
+
+impl NewStreamType {
+    /// Get the final `NewStreamType` from a stream type. All streams, except Push stream,
+    /// are identified by the type only. This function will return None for the Push stream
+    /// because it needs the ID besides the type.
+    ///
+    /// # Errors
+    ///
+    /// Push streams received by the server are not allowed and this function will return
+    /// `HttpStreamCreation` error.
+    fn final_stream_type(
+        stream_type: u64,
+        trans_stream_type: StreamType,
+        role: Role,
+    ) -> Res<Option<NewStreamType>> {
+        match (stream_type, trans_stream_type, role) {
+            (HTTP3_UNI_STREAM_TYPE_CONTROL, StreamType::UniDi, _) => {
+                Ok(Some(NewStreamType::Control))
+            }
+            (QPACK_UNI_STREAM_TYPE_ENCODER, StreamType::UniDi, _) => {
+                Ok(Some(NewStreamType::Decoder))
+            }
+            (QPACK_UNI_STREAM_TYPE_DECODER, StreamType::UniDi, _) => {
+                Ok(Some(NewStreamType::Encoder))
+            }
+            (HTTP3_UNI_STREAM_TYPE_PUSH, StreamType::UniDi, Role::Client)
+            | (WEBTRANSPORT_UNI_STREAM, StreamType::UniDi, _)
+            | (WEBTRANSPORT_STREAM, StreamType::BiDi, _) => Ok(None),
+            (H3_FRAME_TYPE_HEADERS, StreamType::BiDi, Role::Server) => {
+                Ok(Some(NewStreamType::Http))
+            }
+            (_, StreamType::BiDi, Role::Server) => Err(Error::HttpFrame),
+            (HTTP3_UNI_STREAM_TYPE_PUSH, StreamType::UniDi, Role::Server)
+            | (_, StreamType::BiDi, Role::Client) => Err(Error::HttpStreamCreation),
+            _ => Ok(Some(NewStreamType::Unknown)),
+        }
+    }
+}
+
+/// `NewStreamHeadReader` reads the head of an unidirectional stream to identify the stream.
+/// There are 2 type of streams:
+///  - streams identified by the single type (varint encoded). Most streams belong to this category.
+///    The `NewStreamHeadReader` will switch from `ReadType`to `Done` state.
+///  - streams identified by the type and the ID (both varint encoded). For example, a push stream
+///    is identified by the type and `PushId`. After reading the type in the `ReadType` state,
+///    `NewStreamHeadReader` changes to `ReadId` state and from there to `Done` state
+#[derive(Debug)]
+pub(crate) enum NewStreamHeadReader {
+    ReadType {
+        role: Role,
+        reader: IncrementalDecoderUint,
+        stream_id: StreamId,
+    },
+    ReadId {
+        stream_type: u64,
+        reader: IncrementalDecoderUint,
+        stream_id: StreamId,
+    },
+    Done,
+}
+
+impl NewStreamHeadReader {
+    pub fn new(stream_id: StreamId, role: Role) -> Self {
+        NewStreamHeadReader::ReadType {
+            role,
+            reader: IncrementalDecoderUint::default(),
+            stream_id,
+        }
+    }
+
+    fn read(&mut self, conn: &mut Connection) -> Res<(Option<u64>, bool)> {
+        if let NewStreamHeadReader::ReadType {
+            reader, stream_id, ..
+        }
+        | NewStreamHeadReader::ReadId {
+            reader, stream_id, ..
+        } = self
+        {
+            loop {
+                let to_read = reader.min_remaining();
+                let mut buf = vec![0; to_read];
+                match conn.stream_recv(*stream_id, &mut buf[..])? {
+                    (0, f) => return Ok((None, f)),
+                    (amount, f) => {
+                        let res = reader.consume(&mut Decoder::from(&buf[..amount]));
+                        if res.is_some() || f {
+                            return Ok((res, f));
+                        }
+                    }
+                }
+            }
+        } else {
+            Ok((None, false))
+        }
+    }
+
+    pub fn get_type(&mut self, conn: &mut Connection) -> Res<Option<NewStreamType>> {
+        loop {
+            let (output, fin) = self.read(conn)?;
+            let Some(output) = output else {
+                if fin {
+                    *self = NewStreamHeadReader::Done;
+                    return Err(Error::HttpStreamCreation);
+                }
+                return Ok(None);
+            };
+
+            qtrace!("Decoded uint {}", output);
+            match self {
+                NewStreamHeadReader::ReadType {
+                    role, stream_id, ..
+                } => {
+                    // final_stream_type may return:
+                    //  - an error if a stream type is not allowed for the role, e.g. Push stream
+                    //    received at the server.
+                    //  - a final type if a stream is only identify by the type
+                    //  - None - if a stream is not identified by the type only, but it needs
+                    //    additional data from the header to produce the final type, e.g. a push
+                    //    stream needs pushId as well.
+                    let final_type =
+                        NewStreamType::final_stream_type(output, stream_id.stream_type(), *role);
+                    match (&final_type, fin) {
+                        (Err(_), _) => {
+                            *self = NewStreamHeadReader::Done;
+                            return final_type;
+                        }
+                        (Ok(t), true) => {
+                            *self = NewStreamHeadReader::Done;
+                            return Self::map_stream_fin(*t);
+                        }
+                        (Ok(Some(t)), false) => {
+                            qtrace!("Decoded stream type {:?}", *t);
+                            *self = NewStreamHeadReader::Done;
+                            return final_type;
+                        }
+                        (Ok(None), false) => {
+                            // This is a push stream and it needs more data to be decoded.
+                            *self = NewStreamHeadReader::ReadId {
+                                reader: IncrementalDecoderUint::default(),
+                                stream_id: *stream_id,
+                                stream_type: output,
+                            }
+                        }
+                    }
+                }
+                NewStreamHeadReader::ReadId { stream_type, .. } => {
+                    let is_push = *stream_type == HTTP3_UNI_STREAM_TYPE_PUSH;
+                    *self = NewStreamHeadReader::Done;
+                    qtrace!("New Stream stream push_id={}", output);
+                    if fin {
+                        return Err(Error::HttpGeneralProtocol);
+                    }
+                    return if is_push {
+                        Ok(Some(NewStreamType::Push(output)))
+                    } else {
+                        Ok(Some(NewStreamType::WebTransportStream(output)))
+                    };
+                }
+                NewStreamHeadReader::Done => {
+                    unreachable!("Cannot be in state NewStreamHeadReader::Done");
+                }
+            }
+        }
+    }
+
+    fn map_stream_fin(decoded: Option<NewStreamType>) -> Res<Option<NewStreamType>> {
+        match decoded {
+            Some(NewStreamType::Control | NewStreamType::Encoder | NewStreamType::Decoder) => {
+                Err(Error::HttpClosedCriticalStream)
+            }
+            None => Err(Error::HttpStreamCreation),
+            Some(NewStreamType::Http) => Err(Error::HttpFrame),
+            Some(NewStreamType::Unknown) => Ok(decoded),
+            Some(NewStreamType::Push(_) | NewStreamType::WebTransportStream(_)) => {
+                unreachable!("PushStream and WebTransport are mapped to None at this stage.")
+            }
+        }
+    }
+
+    fn done(&self) -> bool {
+        matches!(self, NewStreamHeadReader::Done)
+    }
+}
+
+impl Stream for NewStreamHeadReader {
+    fn stream_type(&self) -> Http3StreamType {
+        Http3StreamType::NewStream
+    }
+}
+
+impl RecvStream for NewStreamHeadReader {
+    fn reset(&mut self, _close_type: CloseType) -> Res<()> {
+        *self = NewStreamHeadReader::Done;
+        Ok(())
+    }
+
+    fn receive(&mut self, conn: &mut Connection) -> Res<(ReceiveOutput, bool)> {
+        Ok((
+            self.get_type(conn)?
+                .map_or(ReceiveOutput::NoOutput, ReceiveOutput::NewStream),
+            self.done(),
+        ))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::mem;
+
+    use neqo_common::{Encoder, Role};
+    use neqo_qpack::{
+        decoder::QPACK_UNI_STREAM_TYPE_DECODER, encoder::QPACK_UNI_STREAM_TYPE_ENCODER,
+    };
+    use neqo_transport::{Connection, StreamId, StreamType};
+    use test_fixture::{connect, now};
+
+    use super::{
+        NewStreamHeadReader, HTTP3_UNI_STREAM_TYPE_PUSH, WEBTRANSPORT_STREAM,
+        WEBTRANSPORT_UNI_STREAM,
+    };
+    use crate::{
+        control_stream_local::HTTP3_UNI_STREAM_TYPE_CONTROL, frames::H3_FRAME_TYPE_HEADERS,
+        CloseType, Error, NewStreamType, ReceiveOutput, RecvStream, Res,
+    };
+
+    struct Test {
+        conn_c: Connection,
+        conn_s: Connection,
+        stream_id: StreamId,
+        decoder: NewStreamHeadReader,
+    }
+
+    impl Test {
+        fn new(stream_type: StreamType, role: Role) -> Self {
+            let (mut conn_c, mut conn_s) = connect();
+            // create a stream
+            let stream_id = conn_s.stream_create(stream_type).unwrap();
+            let out = conn_s.process(None, now());
+            mem::drop(conn_c.process(out.as_dgram_ref(), now()));
+
+            Self {
+                conn_c,
+                conn_s,
+                stream_id,
+                decoder: NewStreamHeadReader::new(stream_id, role),
+            }
+        }
+
+        fn decode_buffer(
+            &mut self,
+            enc: &[u8],
+            fin: bool,
+            outcome: &Res<(ReceiveOutput, bool)>,
+            done: bool,
+        ) {
+            let len = enc.len() - 1;
+            for i in 0..len {
+                self.conn_s
+                    .stream_send(self.stream_id, &enc[i..=i])
+                    .unwrap();
+                let out = self.conn_s.process(None, now());
+                mem::drop(self.conn_c.process(out.as_dgram_ref(), now()));
+                assert_eq!(
+                    self.decoder.receive(&mut self.conn_c).unwrap(),
+                    (ReceiveOutput::NoOutput, false)
+                );
+                assert!(!self.decoder.done());
+            }
+            self.conn_s
+                .stream_send(self.stream_id, &enc[enc.len() - 1..])
+                .unwrap();
+            if fin {
+                self.conn_s.stream_close_send(self.stream_id).unwrap();
+            }
+            let out = self.conn_s.process(None, now());
+            mem::drop(self.conn_c.process(out.dgram().as_ref(), now()));
+            assert_eq!(&self.decoder.receive(&mut self.conn_c), outcome);
+            assert_eq!(self.decoder.done(), done);
+        }
+
+        fn decode(
+            &mut self,
+            to_encode: &[u64],
+            fin: bool,
+            outcome: &Res<(ReceiveOutput, bool)>,
+            done: bool,
+        ) {
+            let mut enc = Encoder::default();
+            for i in to_encode {
+                enc.encode_varint(*i);
+            }
+            self.decode_buffer(enc.as_ref(), fin, outcome, done);
+        }
+    }
+
+    #[test]
+    fn decode_stream_decoder() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_DECODER],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Encoder), true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_encoder() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_ENCODER],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Decoder), true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_control() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_CONTROL],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Control), true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_push() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_PUSH, 0xaaaa_aaaa],
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::Push(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_PUSH],
+            false,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_unknown() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[0x3fff_ffff_ffff_ffff],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Unknown), true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_http() {
+        let mut t = Test::new(StreamType::BiDi, Role::Server);
+        t.decode(
+            &[H3_FRAME_TYPE_HEADERS],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Http), true)),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[H3_FRAME_TYPE_HEADERS], /* this is the same as a HTTP3_UNI_STREAM_TYPE_PUSH which
+                                       * is not aallowed on the server side. */
+            false,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Client);
+        t.decode(
+            &[H3_FRAME_TYPE_HEADERS],
+            false,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[H3_FRAME_TYPE_HEADERS, 0xaaaa_aaaa], /* this is the same as a
+                                                    * HTTP3_UNI_STREAM_TYPE_PUSH */
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::Push(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_wt_bidi() {
+        let mut t = Test::new(StreamType::BiDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_STREAM, 0xaaaa_aaaa],
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::WebTransportStream(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_STREAM],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Unknown), true)),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_STREAM, 0xaaaa_aaaa],
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::WebTransportStream(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_STREAM],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Unknown), true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decode_stream_wt_unidi() {
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM, 0xaaaa_aaaa],
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::WebTransportStream(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM],
+            false,
+            &Err(Error::HttpFrame),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM, 0xaaaa_aaaa],
+            false,
+            &Ok((
+                ReceiveOutput::NewStream(NewStreamType::WebTransportStream(0xaaaa_aaaa)),
+                true,
+            )),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM],
+            false,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+    }
+
+    #[test]
+    fn done_decoding() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[0x3fff],
+            false,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Unknown), true)),
+            true,
+        );
+        // NewStreamHeadReader is done, it will not continue reading from the stream.
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_DECODER],
+            false,
+            &Ok((ReceiveOutput::NoOutput, true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn decoding_truncate() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode_buffer(&[0xff], false, &Ok((ReceiveOutput::NoOutput, false)), false);
+    }
+
+    #[test]
+    fn reset() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decoder.reset(CloseType::ResetRemote(0x100)).unwrap();
+        // after a reset NewStreamHeadReader will not read more data.
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_DECODER],
+            false,
+            &Ok((ReceiveOutput::NoOutput, true)),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_decoder() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_DECODER],
+            true,
+            &Err(Error::HttpClosedCriticalStream),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_encoder() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[QPACK_UNI_STREAM_TYPE_ENCODER],
+            true,
+            &Err(Error::HttpClosedCriticalStream),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_control() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_CONTROL],
+            true,
+            &Err(Error::HttpClosedCriticalStream),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_push() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_PUSH, 0xaaaa_aaaa],
+            true,
+            &Err(Error::HttpGeneralProtocol),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[HTTP3_UNI_STREAM_TYPE_PUSH],
+            true,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_wt() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM, 0xaaaa_aaaa],
+            true,
+            &Err(Error::HttpGeneralProtocol),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM],
+            true,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM, 0xaaaa_aaaa],
+            true,
+            &Err(Error::HttpGeneralProtocol),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_UNI_STREAM],
+            true,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_STREAM, 0xaaaa_aaaa],
+            true,
+            &Err(Error::HttpGeneralProtocol),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Client);
+        t.decode(
+            &[WEBTRANSPORT_STREAM],
+            true,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_STREAM, 0xaaaa_aaaa],
+            true,
+            &Err(Error::HttpGeneralProtocol),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::BiDi, Role::Server);
+        t.decode(
+            &[WEBTRANSPORT_STREAM],
+            true,
+            &Err(Error::HttpStreamCreation),
+            true,
+        );
+    }
+
+    #[test]
+    fn stream_fin_uknown() {
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        t.decode(
+            &[0x3fff_ffff_ffff_ffff],
+            true,
+            &Ok((ReceiveOutput::NewStream(NewStreamType::Unknown), true)),
+            true,
+        );
+
+        let mut t = Test::new(StreamType::UniDi, Role::Client);
+        // A stream ID of 0x3fff_ffff_ffff_ffff is encoded into [0xff; 8].
+        // For this test the stream type is truncated.
+        // This should cause an error.
+        t.decode_buffer(&[0xff; 7], true, &Err(Error::HttpStreamCreation), true);
+    }
+}