Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 1039 insertions, 0 deletions

diff --git a/third_party/rust/h2/src/frame/headers.rs b/third_party/rust/h2/src/frame/headers.rs
new file mode 100644
index 0000000000..bcb9050133
--- /dev/null
+++ b/third_party/rust/h2/src/frame/headers.rs
@@ -0,0 +1,1039 @@
+use super::{util, StreamDependency, StreamId};
+use crate::ext::Protocol;
+use crate::frame::{Error, Frame, Head, Kind};
+use crate::hpack::{self, BytesStr};
+
+use http::header::{self, HeaderName, HeaderValue};
+use http::{uri, HeaderMap, Method, Request, StatusCode, Uri};
+
+use bytes::{BufMut, Bytes, BytesMut};
+
+use std::fmt;
+use std::io::Cursor;
+
+type EncodeBuf<'a> = bytes::buf::Limit<&'a mut BytesMut>;
+/// Header frame
+///
+/// This could be either a request or a response.
+#[derive(Eq, PartialEq)]
+pub struct Headers {
+    /// The ID of the stream with which this frame is associated.
+    stream_id: StreamId,
+
+    /// The stream dependency information, if any.
+    stream_dep: Option<StreamDependency>,
+
+    /// The header block fragment
+    header_block: HeaderBlock,
+
+    /// The associated flags
+    flags: HeadersFlag,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct HeadersFlag(u8);
+
+#[derive(Eq, PartialEq)]
+pub struct PushPromise {
+    /// The ID of the stream with which this frame is associated.
+    stream_id: StreamId,
+
+    /// The ID of the stream being reserved by this PushPromise.
+    promised_id: StreamId,
+
+    /// The header block fragment
+    header_block: HeaderBlock,
+
+    /// The associated flags
+    flags: PushPromiseFlag,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct PushPromiseFlag(u8);
+
+#[derive(Debug)]
+pub struct Continuation {
+    /// Stream ID of continuation frame
+    stream_id: StreamId,
+
+    header_block: EncodingHeaderBlock,
+}
+
+// TODO: These fields shouldn't be `pub`
+#[derive(Debug, Default, Eq, PartialEq)]
+pub struct Pseudo {
+    // Request
+    pub method: Option<Method>,
+    pub scheme: Option<BytesStr>,
+    pub authority: Option<BytesStr>,
+    pub path: Option<BytesStr>,
+    pub protocol: Option<Protocol>,
+
+    // Response
+    pub status: Option<StatusCode>,
+}
+
+#[derive(Debug)]
+pub struct Iter {
+    /// Pseudo headers
+    pseudo: Option<Pseudo>,
+
+    /// Header fields
+    fields: header::IntoIter<HeaderValue>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct HeaderBlock {
+    /// The decoded header fields
+    fields: HeaderMap,
+
+    /// Set to true if decoding went over the max header list size.
+    is_over_size: bool,
+
+    /// Pseudo headers, these are broken out as they must be sent as part of the
+    /// headers frame.
+    pseudo: Pseudo,
+}
+
+#[derive(Debug)]
+struct EncodingHeaderBlock {
+    hpack: Bytes,
+}
+
+const END_STREAM: u8 = 0x1;
+const END_HEADERS: u8 = 0x4;
+const PADDED: u8 = 0x8;
+const PRIORITY: u8 = 0x20;
+const ALL: u8 = END_STREAM | END_HEADERS | PADDED | PRIORITY;
+
+// ===== impl Headers =====
+
+impl Headers {
+    /// Create a new HEADERS frame
+    pub fn new(stream_id: StreamId, pseudo: Pseudo, fields: HeaderMap) -> Self {
+        Headers {
+            stream_id,
+            stream_dep: None,
+            header_block: HeaderBlock {
+                fields,
+                is_over_size: false,
+                pseudo,
+            },
+            flags: HeadersFlag::default(),
+        }
+    }
+
+    pub fn trailers(stream_id: StreamId, fields: HeaderMap) -> Self {
+        let mut flags = HeadersFlag::default();
+        flags.set_end_stream();
+
+        Headers {
+            stream_id,
+            stream_dep: None,
+            header_block: HeaderBlock {
+                fields,
+                is_over_size: false,
+                pseudo: Pseudo::default(),
+            },
+            flags,
+        }
+    }
+
+    /// Loads the header frame but doesn't actually do HPACK decoding.
+    ///
+    /// HPACK decoding is done in the `load_hpack` step.
+    pub fn load(head: Head, mut src: BytesMut) -> Result<(Self, BytesMut), Error> {
+        let flags = HeadersFlag(head.flag());
+        let mut pad = 0;
+
+        tracing::trace!("loading headers; flags={:?}", flags);
+
+        if head.stream_id().is_zero() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        // Read the padding length
+        if flags.is_padded() {
+            if src.is_empty() {
+                return Err(Error::MalformedMessage);
+            }
+            pad = src[0] as usize;
+
+            // Drop the padding
+            let _ = src.split_to(1);
+        }
+
+        // Read the stream dependency
+        let stream_dep = if flags.is_priority() {
+            if src.len() < 5 {
+                return Err(Error::MalformedMessage);
+            }
+            let stream_dep = StreamDependency::load(&src[..5])?;
+
+            if stream_dep.dependency_id() == head.stream_id() {
+                return Err(Error::InvalidDependencyId);
+            }
+
+            // Drop the next 5 bytes
+            let _ = src.split_to(5);
+
+            Some(stream_dep)
+        } else {
+            None
+        };
+
+        if pad > 0 {
+            if pad > src.len() {
+                return Err(Error::TooMuchPadding);
+            }
+
+            let len = src.len() - pad;
+            src.truncate(len);
+        }
+
+        let headers = Headers {
+            stream_id: head.stream_id(),
+            stream_dep,
+            header_block: HeaderBlock {
+                fields: HeaderMap::new(),
+                is_over_size: false,
+                pseudo: Pseudo::default(),
+            },
+            flags,
+        };
+
+        Ok((headers, src))
+    }
+
+    pub fn load_hpack(
+        &mut self,
+        src: &mut BytesMut,
+        max_header_list_size: usize,
+        decoder: &mut hpack::Decoder,
+    ) -> Result<(), Error> {
+        self.header_block.load(src, max_header_list_size, decoder)
+    }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn is_end_headers(&self) -> bool {
+        self.flags.is_end_headers()
+    }
+
+    pub fn set_end_headers(&mut self) {
+        self.flags.set_end_headers();
+    }
+
+    pub fn is_end_stream(&self) -> bool {
+        self.flags.is_end_stream()
+    }
+
+    pub fn set_end_stream(&mut self) {
+        self.flags.set_end_stream()
+    }
+
+    pub fn is_over_size(&self) -> bool {
+        self.header_block.is_over_size
+    }
+
+    pub fn into_parts(self) -> (Pseudo, HeaderMap) {
+        (self.header_block.pseudo, self.header_block.fields)
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn pseudo_mut(&mut self) -> &mut Pseudo {
+        &mut self.header_block.pseudo
+    }
+
+    /// Whether it has status 1xx
+    pub(crate) fn is_informational(&self) -> bool {
+        self.header_block.pseudo.is_informational()
+    }
+
+    pub fn fields(&self) -> &HeaderMap {
+        &self.header_block.fields
+    }
+
+    pub fn into_fields(self) -> HeaderMap {
+        self.header_block.fields
+    }
+
+    pub fn encode(
+        self,
+        encoder: &mut hpack::Encoder,
+        dst: &mut EncodeBuf<'_>,
+    ) -> Option<Continuation> {
+        // At this point, the `is_end_headers` flag should always be set
+        debug_assert!(self.flags.is_end_headers());
+
+        // Get the HEADERS frame head
+        let head = self.head();
+
+        self.header_block
+            .into_encoding(encoder)
+            .encode(&head, dst, |_| {})
+    }
+
+    fn head(&self) -> Head {
+        Head::new(Kind::Headers, self.flags.into(), self.stream_id)
+    }
+}
+
+impl<T> From<Headers> for Frame<T> {
+    fn from(src: Headers) -> Self {
+        Frame::Headers(src)
+    }
+}
+
+impl fmt::Debug for Headers {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut builder = f.debug_struct("Headers");
+        builder
+            .field("stream_id", &self.stream_id)
+            .field("flags", &self.flags);
+
+        if let Some(ref protocol) = self.header_block.pseudo.protocol {
+            builder.field("protocol", protocol);
+        }
+
+        if let Some(ref dep) = self.stream_dep {
+            builder.field("stream_dep", dep);
+        }
+
+        // `fields` and `pseudo` purposefully not included
+        builder.finish()
+    }
+}
+
+// ===== util =====
+
+pub fn parse_u64(src: &[u8]) -> Result<u64, ()> {
+    if src.len() > 19 {
+        // At danger for overflow...
+        return Err(());
+    }
+
+    let mut ret = 0;
+
+    for &d in src {
+        if d < b'0' || d > b'9' {
+            return Err(());
+        }
+
+        ret *= 10;
+        ret += (d - b'0') as u64;
+    }
+
+    Ok(ret)
+}
+
+// ===== impl PushPromise =====
+
+#[derive(Debug)]
+pub enum PushPromiseHeaderError {
+    InvalidContentLength(Result<u64, ()>),
+    NotSafeAndCacheable,
+}
+
+impl PushPromise {
+    pub fn new(
+        stream_id: StreamId,
+        promised_id: StreamId,
+        pseudo: Pseudo,
+        fields: HeaderMap,
+    ) -> Self {
+        PushPromise {
+            flags: PushPromiseFlag::default(),
+            header_block: HeaderBlock {
+                fields,
+                is_over_size: false,
+                pseudo,
+            },
+            promised_id,
+            stream_id,
+        }
+    }
+
+    pub fn validate_request(req: &Request<()>) -> Result<(), PushPromiseHeaderError> {
+        use PushPromiseHeaderError::*;
+        // The spec has some requirements for promised request headers
+        // [https://httpwg.org/specs/rfc7540.html#PushRequests]
+
+        // A promised request "that indicates the presence of a request body
+        // MUST reset the promised stream with a stream error"
+        if let Some(content_length) = req.headers().get(header::CONTENT_LENGTH) {
+            let parsed_length = parse_u64(content_length.as_bytes());
+            if parsed_length != Ok(0) {
+                return Err(InvalidContentLength(parsed_length));
+            }
+        }
+        // "The server MUST include a method in the :method pseudo-header field
+        // that is safe and cacheable"
+        if !Self::safe_and_cacheable(req.method()) {
+            return Err(NotSafeAndCacheable);
+        }
+
+        Ok(())
+    }
+
+    fn safe_and_cacheable(method: &Method) -> bool {
+        // Cacheable: https://httpwg.org/specs/rfc7231.html#cacheable.methods
+        // Safe: https://httpwg.org/specs/rfc7231.html#safe.methods
+        return method == Method::GET || method == Method::HEAD;
+    }
+
+    pub fn fields(&self) -> &HeaderMap {
+        &self.header_block.fields
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn into_fields(self) -> HeaderMap {
+        self.header_block.fields
+    }
+
+    /// Loads the push promise frame but doesn't actually do HPACK decoding.
+    ///
+    /// HPACK decoding is done in the `load_hpack` step.
+    pub fn load(head: Head, mut src: BytesMut) -> Result<(Self, BytesMut), Error> {
+        let flags = PushPromiseFlag(head.flag());
+        let mut pad = 0;
+
+        if head.stream_id().is_zero() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        // Read the padding length
+        if flags.is_padded() {
+            if src.is_empty() {
+                return Err(Error::MalformedMessage);
+            }
+
+            // TODO: Ensure payload is sized correctly
+            pad = src[0] as usize;
+
+            // Drop the padding
+            let _ = src.split_to(1);
+        }
+
+        if src.len() < 5 {
+            return Err(Error::MalformedMessage);
+        }
+
+        let (promised_id, _) = StreamId::parse(&src[..4]);
+        // Drop promised_id bytes
+        let _ = src.split_to(4);
+
+        if pad > 0 {
+            if pad > src.len() {
+                return Err(Error::TooMuchPadding);
+            }
+
+            let len = src.len() - pad;
+            src.truncate(len);
+        }
+
+        let frame = PushPromise {
+            flags,
+            header_block: HeaderBlock {
+                fields: HeaderMap::new(),
+                is_over_size: false,
+                pseudo: Pseudo::default(),
+            },
+            promised_id,
+            stream_id: head.stream_id(),
+        };
+        Ok((frame, src))
+    }
+
+    pub fn load_hpack(
+        &mut self,
+        src: &mut BytesMut,
+        max_header_list_size: usize,
+        decoder: &mut hpack::Decoder,
+    ) -> Result<(), Error> {
+        self.header_block.load(src, max_header_list_size, decoder)
+    }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn promised_id(&self) -> StreamId {
+        self.promised_id
+    }
+
+    pub fn is_end_headers(&self) -> bool {
+        self.flags.is_end_headers()
+    }
+
+    pub fn set_end_headers(&mut self) {
+        self.flags.set_end_headers();
+    }
+
+    pub fn is_over_size(&self) -> bool {
+        self.header_block.is_over_size
+    }
+
+    pub fn encode(
+        self,
+        encoder: &mut hpack::Encoder,
+        dst: &mut EncodeBuf<'_>,
+    ) -> Option<Continuation> {
+        // At this point, the `is_end_headers` flag should always be set
+        debug_assert!(self.flags.is_end_headers());
+
+        let head = self.head();
+        let promised_id = self.promised_id;
+
+        self.header_block
+            .into_encoding(encoder)
+            .encode(&head, dst, |dst| {
+                dst.put_u32(promised_id.into());
+            })
+    }
+
+    fn head(&self) -> Head {
+        Head::new(Kind::PushPromise, self.flags.into(), self.stream_id)
+    }
+
+    /// Consume `self`, returning the parts of the frame
+    pub fn into_parts(self) -> (Pseudo, HeaderMap) {
+        (self.header_block.pseudo, self.header_block.fields)
+    }
+}
+
+impl<T> From<PushPromise> for Frame<T> {
+    fn from(src: PushPromise) -> Self {
+        Frame::PushPromise(src)
+    }
+}
+
+impl fmt::Debug for PushPromise {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("PushPromise")
+            .field("stream_id", &self.stream_id)
+            .field("promised_id", &self.promised_id)
+            .field("flags", &self.flags)
+            // `fields` and `pseudo` purposefully not included
+            .finish()
+    }
+}
+
+// ===== impl Continuation =====
+
+impl Continuation {
+    fn head(&self) -> Head {
+        Head::new(Kind::Continuation, END_HEADERS, self.stream_id)
+    }
+
+    pub fn encode(self, dst: &mut EncodeBuf<'_>) -> Option<Continuation> {
+        // Get the CONTINUATION frame head
+        let head = self.head();
+
+        self.header_block.encode(&head, dst, |_| {})
+    }
+}
+
+// ===== impl Pseudo =====
+
+impl Pseudo {
+    pub fn request(method: Method, uri: Uri, protocol: Option<Protocol>) -> Self {
+        let parts = uri::Parts::from(uri);
+
+        let mut path = parts
+            .path_and_query
+            .map(|v| BytesStr::from(v.as_str()))
+            .unwrap_or(BytesStr::from_static(""));
+
+        match method {
+            Method::OPTIONS | Method::CONNECT => {}
+            _ if path.is_empty() => {
+                path = BytesStr::from_static("/");
+            }
+            _ => {}
+        }
+
+        let mut pseudo = Pseudo {
+            method: Some(method),
+            scheme: None,
+            authority: None,
+            path: Some(path).filter(|p| !p.is_empty()),
+            protocol,
+            status: None,
+        };
+
+        // If the URI includes a scheme component, add it to the pseudo headers
+        //
+        // TODO: Scheme must be set...
+        if let Some(scheme) = parts.scheme {
+            pseudo.set_scheme(scheme);
+        }
+
+        // If the URI includes an authority component, add it to the pseudo
+        // headers
+        if let Some(authority) = parts.authority {
+            pseudo.set_authority(BytesStr::from(authority.as_str()));
+        }
+
+        pseudo
+    }
+
+    pub fn response(status: StatusCode) -> Self {
+        Pseudo {
+            method: None,
+            scheme: None,
+            authority: None,
+            path: None,
+            protocol: None,
+            status: Some(status),
+        }
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn set_status(&mut self, value: StatusCode) {
+        self.status = Some(value);
+    }
+
+    pub fn set_scheme(&mut self, scheme: uri::Scheme) {
+        let bytes_str = match scheme.as_str() {
+            "http" => BytesStr::from_static("http"),
+            "https" => BytesStr::from_static("https"),
+            s => BytesStr::from(s),
+        };
+        self.scheme = Some(bytes_str);
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn set_protocol(&mut self, protocol: Protocol) {
+        self.protocol = Some(protocol);
+    }
+
+    pub fn set_authority(&mut self, authority: BytesStr) {
+        self.authority = Some(authority);
+    }
+
+    /// Whether it has status 1xx
+    pub(crate) fn is_informational(&self) -> bool {
+        self.status
+            .map_or(false, |status| status.is_informational())
+    }
+}
+
+// ===== impl EncodingHeaderBlock =====
+
+impl EncodingHeaderBlock {
+    fn encode<F>(mut self, head: &Head, dst: &mut EncodeBuf<'_>, f: F) -> Option<Continuation>
+    where
+        F: FnOnce(&mut EncodeBuf<'_>),
+    {
+        let head_pos = dst.get_ref().len();
+
+        // At this point, we don't know how big the h2 frame will be.
+        // So, we write the head with length 0, then write the body, and
+        // finally write the length once we know the size.
+        head.encode(0, dst);
+
+        let payload_pos = dst.get_ref().len();
+
+        f(dst);
+
+        // Now, encode the header payload
+        let continuation = if self.hpack.len() > dst.remaining_mut() {
+            dst.put_slice(&self.hpack.split_to(dst.remaining_mut()));
+
+            Some(Continuation {
+                stream_id: head.stream_id(),
+                header_block: self,
+            })
+        } else {
+            dst.put_slice(&self.hpack);
+
+            None
+        };
+
+        // Compute the header block length
+        let payload_len = (dst.get_ref().len() - payload_pos) as u64;
+
+        // Write the frame length
+        let payload_len_be = payload_len.to_be_bytes();
+        assert!(payload_len_be[0..5].iter().all(|b| *b == 0));
+        (dst.get_mut()[head_pos..head_pos + 3]).copy_from_slice(&payload_len_be[5..]);
+
+        if continuation.is_some() {
+            // There will be continuation frames, so the `is_end_headers` flag
+            // must be unset
+            debug_assert!(dst.get_ref()[head_pos + 4] & END_HEADERS == END_HEADERS);
+
+            dst.get_mut()[head_pos + 4] -= END_HEADERS;
+        }
+
+        continuation
+    }
+}
+
+// ===== impl Iter =====
+
+impl Iterator for Iter {
+    type Item = hpack::Header<Option<HeaderName>>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        use crate::hpack::Header::*;
+
+        if let Some(ref mut pseudo) = self.pseudo {
+            if let Some(method) = pseudo.method.take() {
+                return Some(Method(method));
+            }
+
+            if let Some(scheme) = pseudo.scheme.take() {
+                return Some(Scheme(scheme));
+            }
+
+            if let Some(authority) = pseudo.authority.take() {
+                return Some(Authority(authority));
+            }
+
+            if let Some(path) = pseudo.path.take() {
+                return Some(Path(path));
+            }
+
+            if let Some(protocol) = pseudo.protocol.take() {
+                return Some(Protocol(protocol));
+            }
+
+            if let Some(status) = pseudo.status.take() {
+                return Some(Status(status));
+            }
+        }
+
+        self.pseudo = None;
+
+        self.fields
+            .next()
+            .map(|(name, value)| Field { name, value })
+    }
+}
+
+// ===== impl HeadersFlag =====
+
+impl HeadersFlag {
+    pub fn empty() -> HeadersFlag {
+        HeadersFlag(0)
+    }
+
+    pub fn load(bits: u8) -> HeadersFlag {
+        HeadersFlag(bits & ALL)
+    }
+
+    pub fn is_end_stream(&self) -> bool {
+        self.0 & END_STREAM == END_STREAM
+    }
+
+    pub fn set_end_stream(&mut self) {
+        self.0 |= END_STREAM;
+    }
+
+    pub fn is_end_headers(&self) -> bool {
+        self.0 & END_HEADERS == END_HEADERS
+    }
+
+    pub fn set_end_headers(&mut self) {
+        self.0 |= END_HEADERS;
+    }
+
+    pub fn is_padded(&self) -> bool {
+        self.0 & PADDED == PADDED
+    }
+
+    pub fn is_priority(&self) -> bool {
+        self.0 & PRIORITY == PRIORITY
+    }
+}
+
+impl Default for HeadersFlag {
+    /// Returns a `HeadersFlag` value with `END_HEADERS` set.
+    fn default() -> Self {
+        HeadersFlag(END_HEADERS)
+    }
+}
+
+impl From<HeadersFlag> for u8 {
+    fn from(src: HeadersFlag) -> u8 {
+        src.0
+    }
+}
+
+impl fmt::Debug for HeadersFlag {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        util::debug_flags(fmt, self.0)
+            .flag_if(self.is_end_headers(), "END_HEADERS")
+            .flag_if(self.is_end_stream(), "END_STREAM")
+            .flag_if(self.is_padded(), "PADDED")
+            .flag_if(self.is_priority(), "PRIORITY")
+            .finish()
+    }
+}
+
+// ===== impl PushPromiseFlag =====
+
+impl PushPromiseFlag {
+    pub fn empty() -> PushPromiseFlag {
+        PushPromiseFlag(0)
+    }
+
+    pub fn load(bits: u8) -> PushPromiseFlag {
+        PushPromiseFlag(bits & ALL)
+    }
+
+    pub fn is_end_headers(&self) -> bool {
+        self.0 & END_HEADERS == END_HEADERS
+    }
+
+    pub fn set_end_headers(&mut self) {
+        self.0 |= END_HEADERS;
+    }
+
+    pub fn is_padded(&self) -> bool {
+        self.0 & PADDED == PADDED
+    }
+}
+
+impl Default for PushPromiseFlag {
+    /// Returns a `PushPromiseFlag` value with `END_HEADERS` set.
+    fn default() -> Self {
+        PushPromiseFlag(END_HEADERS)
+    }
+}
+
+impl From<PushPromiseFlag> for u8 {
+    fn from(src: PushPromiseFlag) -> u8 {
+        src.0
+    }
+}
+
+impl fmt::Debug for PushPromiseFlag {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        util::debug_flags(fmt, self.0)
+            .flag_if(self.is_end_headers(), "END_HEADERS")
+            .flag_if(self.is_padded(), "PADDED")
+            .finish()
+    }
+}
+
+// ===== HeaderBlock =====
+
+impl HeaderBlock {
+    fn load(
+        &mut self,
+        src: &mut BytesMut,
+        max_header_list_size: usize,
+        decoder: &mut hpack::Decoder,
+    ) -> Result<(), Error> {
+        let mut reg = !self.fields.is_empty();
+        let mut malformed = false;
+        let mut headers_size = self.calculate_header_list_size();
+
+        macro_rules! set_pseudo {
+            ($field:ident, $val:expr) => {{
+                if reg {
+                    tracing::trace!("load_hpack; header malformed -- pseudo not at head of block");
+                    malformed = true;
+                } else if self.pseudo.$field.is_some() {
+                    tracing::trace!("load_hpack; header malformed -- repeated pseudo");
+                    malformed = true;
+                } else {
+                    let __val = $val;
+                    headers_size +=
+                        decoded_header_size(stringify!($field).len() + 1, __val.as_str().len());
+                    if headers_size < max_header_list_size {
+                        self.pseudo.$field = Some(__val);
+                    } else if !self.is_over_size {
+                        tracing::trace!("load_hpack; header list size over max");
+                        self.is_over_size = true;
+                    }
+                }
+            }};
+        }
+
+        let mut cursor = Cursor::new(src);
+
+        // If the header frame is malformed, we still have to continue decoding
+        // the headers. A malformed header frame is a stream level error, but
+        // the hpack state is connection level. In order to maintain correct
+        // state for other streams, the hpack decoding process must complete.
+        let res = decoder.decode(&mut cursor, |header| {
+            use crate::hpack::Header::*;
+
+            match header {
+                Field { name, value } => {
+                    // Connection level header fields are not supported and must
+                    // result in a protocol error.
+
+                    if name == header::CONNECTION
+                        || name == header::TRANSFER_ENCODING
+                        || name == header::UPGRADE
+                        || name == "keep-alive"
+                        || name == "proxy-connection"
+                    {
+                        tracing::trace!("load_hpack; connection level header");
+                        malformed = true;
+                    } else if name == header::TE && value != "trailers" {
+                        tracing::trace!(
+                            "load_hpack; TE header not set to trailers; val={:?}",
+                            value
+                        );
+                        malformed = true;
+                    } else {
+                        reg = true;
+
+                        headers_size += decoded_header_size(name.as_str().len(), value.len());
+                        if headers_size < max_header_list_size {
+                            self.fields.append(name, value);
+                        } else if !self.is_over_size {
+                            tracing::trace!("load_hpack; header list size over max");
+                            self.is_over_size = true;
+                        }
+                    }
+                }
+                Authority(v) => set_pseudo!(authority, v),
+                Method(v) => set_pseudo!(method, v),
+                Scheme(v) => set_pseudo!(scheme, v),
+                Path(v) => set_pseudo!(path, v),
+                Protocol(v) => set_pseudo!(protocol, v),
+                Status(v) => set_pseudo!(status, v),
+            }
+        });
+
+        if let Err(e) = res {
+            tracing::trace!("hpack decoding error; err={:?}", e);
+            return Err(e.into());
+        }
+
+        if malformed {
+            tracing::trace!("malformed message");
+            return Err(Error::MalformedMessage);
+        }
+
+        Ok(())
+    }
+
+    fn into_encoding(self, encoder: &mut hpack::Encoder) -> EncodingHeaderBlock {
+        let mut hpack = BytesMut::new();
+        let headers = Iter {
+            pseudo: Some(self.pseudo),
+            fields: self.fields.into_iter(),
+        };
+
+        encoder.encode(headers, &mut hpack);
+
+        EncodingHeaderBlock {
+            hpack: hpack.freeze(),
+        }
+    }
+
+    /// Calculates the size of the currently decoded header list.
+    ///
+    /// According to http://httpwg.org/specs/rfc7540.html#SETTINGS_MAX_HEADER_LIST_SIZE
+    ///
+    /// > The value is based on the uncompressed size of header fields,
+    /// > including the length of the name and value in octets plus an
+    /// > overhead of 32 octets for each header field.
+    fn calculate_header_list_size(&self) -> usize {
+        macro_rules! pseudo_size {
+            ($name:ident) => {{
+                self.pseudo
+                    .$name
+                    .as_ref()
+                    .map(|m| decoded_header_size(stringify!($name).len() + 1, m.as_str().len()))
+                    .unwrap_or(0)
+            }};
+        }
+
+        pseudo_size!(method)
+            + pseudo_size!(scheme)
+            + pseudo_size!(status)
+            + pseudo_size!(authority)
+            + pseudo_size!(path)
+            + self
+                .fields
+                .iter()
+                .map(|(name, value)| decoded_header_size(name.as_str().len(), value.len()))
+                .sum::<usize>()
+    }
+}
+
+fn decoded_header_size(name: usize, value: usize) -> usize {
+    name + value + 32
+}
+
+#[cfg(test)]
+mod test {
+    use std::iter::FromIterator;
+
+    use http::HeaderValue;
+
+    use super::*;
+    use crate::frame;
+    use crate::hpack::{huffman, Encoder};
+
+    #[test]
+    fn test_nameless_header_at_resume() {
+        let mut encoder = Encoder::default();
+        let mut dst = BytesMut::new();
+
+        let headers = Headers::new(
+            StreamId::ZERO,
+            Default::default(),
+            HeaderMap::from_iter(vec![
+                (
+                    HeaderName::from_static("hello"),
+                    HeaderValue::from_static("world"),
+                ),
+                (
+                    HeaderName::from_static("hello"),
+                    HeaderValue::from_static("zomg"),
+                ),
+                (
+                    HeaderName::from_static("hello"),
+                    HeaderValue::from_static("sup"),
+                ),
+            ]),
+        );
+
+        let continuation = headers
+            .encode(&mut encoder, &mut (&mut dst).limit(frame::HEADER_LEN + 8))
+            .unwrap();
+
+        assert_eq!(17, dst.len());
+        assert_eq!([0, 0, 8, 1, 0, 0, 0, 0, 0], &dst[0..9]);
+        assert_eq!(&[0x40, 0x80 | 4], &dst[9..11]);
+        assert_eq!("hello", huff_decode(&dst[11..15]));
+        assert_eq!(0x80 | 4, dst[15]);
+
+        let mut world = dst[16..17].to_owned();
+
+        dst.clear();
+
+        assert!(continuation
+            .encode(&mut (&mut dst).limit(frame::HEADER_LEN + 16))
+            .is_none());
+
+        world.extend_from_slice(&dst[9..12]);
+        assert_eq!("world", huff_decode(&world));
+
+        assert_eq!(24, dst.len());
+        assert_eq!([0, 0, 15, 9, 4, 0, 0, 0, 0], &dst[0..9]);
+
+        // // Next is not indexed
+        assert_eq!(&[15, 47, 0x80 | 3], &dst[12..15]);
+        assert_eq!("zomg", huff_decode(&dst[15..18]));
+        assert_eq!(&[15, 47, 0x80 | 3], &dst[18..21]);
+        assert_eq!("sup", huff_decode(&dst[21..]));
+    }
+
+    fn huff_decode(src: &[u8]) -> BytesMut {
+        let mut buf = BytesMut::new();
+        huffman::decode(src, &mut buf).unwrap()
+    }
+}