diff options
Diffstat (limited to 'third_party/rust/h2/src/proto/streams/recv.rs')
| -rw-r--r-- | third_party/rust/h2/src/proto/streams/recv.rs | 1097 |
1 files changed, 1097 insertions, 0 deletions
diff --git a/third_party/rust/h2/src/proto/streams/recv.rs b/third_party/rust/h2/src/proto/streams/recv.rs new file mode 100644 index 0000000000..3af1af3a1d --- /dev/null +++ b/third_party/rust/h2/src/proto/streams/recv.rs @@ -0,0 +1,1097 @@ +use super::*; +use crate::codec::UserError; +use crate::frame::{self, PushPromiseHeaderError, Reason, DEFAULT_INITIAL_WINDOW_SIZE}; +use crate::proto::{self, Error}; +use std::task::Context; + +use http::{HeaderMap, Request, Response}; + +use std::io; +use std::task::{Poll, Waker}; +use std::time::{Duration, Instant}; + +#[derive(Debug)] +pub(super) struct Recv { + /// Initial window size of remote initiated streams + init_window_sz: WindowSize, + + /// Connection level flow control governing received data + flow: FlowControl, + + /// Amount of connection window capacity currently used by outstanding streams. + in_flight_data: WindowSize, + + /// The lowest stream ID that is still idle + next_stream_id: Result<StreamId, StreamIdOverflow>, + + /// The stream ID of the last processed stream + last_processed_id: StreamId, + + /// Any streams with a higher ID are ignored. + /// + /// This starts as MAX, but is lowered when a GOAWAY is received. + /// + /// > After sending a GOAWAY frame, the sender can discard frames for + /// > streams initiated by the receiver with identifiers higher than + /// > the identified last stream. + max_stream_id: StreamId, + + /// Streams that have pending window updates + pending_window_updates: store::Queue<stream::NextWindowUpdate>, + + /// New streams to be accepted + pending_accept: store::Queue<stream::NextAccept>, + + /// Locally reset streams that should be reaped when they expire + pending_reset_expired: store::Queue<stream::NextResetExpire>, + + /// How long locally reset streams should ignore received frames + reset_duration: Duration, + + /// Holds frames that are waiting to be read + buffer: Buffer<Event>, + + /// Refused StreamId, this represents a frame that must be sent out. + refused: Option<StreamId>, + + /// If push promises are allowed to be received. + is_push_enabled: bool, + + /// If extended connect protocol is enabled. + is_extended_connect_protocol_enabled: bool, +} + +#[derive(Debug)] +pub(super) enum Event { + Headers(peer::PollMessage), + Data(Bytes), + Trailers(HeaderMap), +} + +#[derive(Debug)] +pub(super) enum RecvHeaderBlockError<T> { + Oversize(T), + State(Error), +} + +#[derive(Debug)] +pub(crate) enum Open { + PushPromise, + Headers, +} + +impl Recv { + pub fn new(peer: peer::Dyn, config: &Config) -> Self { + let next_stream_id = if peer.is_server() { 1 } else { 2 }; + + let mut flow = FlowControl::new(); + + // connections always have the default window size, regardless of + // settings + flow.inc_window(DEFAULT_INITIAL_WINDOW_SIZE) + .expect("invalid initial remote window size"); + flow.assign_capacity(DEFAULT_INITIAL_WINDOW_SIZE); + + Recv { + init_window_sz: config.local_init_window_sz, + flow, + in_flight_data: 0 as WindowSize, + next_stream_id: Ok(next_stream_id.into()), + pending_window_updates: store::Queue::new(), + last_processed_id: StreamId::ZERO, + max_stream_id: StreamId::MAX, + pending_accept: store::Queue::new(), + pending_reset_expired: store::Queue::new(), + reset_duration: config.local_reset_duration, + buffer: Buffer::new(), + refused: None, + is_push_enabled: config.local_push_enabled, + is_extended_connect_protocol_enabled: config.extended_connect_protocol_enabled, + } + } + + /// Returns the initial receive window size + pub fn init_window_sz(&self) -> WindowSize { + self.init_window_sz + } + + /// Returns the ID of the last processed stream + pub fn last_processed_id(&self) -> StreamId { + self.last_processed_id + } + + /// Update state reflecting a new, remotely opened stream + /// + /// Returns the stream state if successful. `None` if refused + pub fn open( + &mut self, + id: StreamId, + mode: Open, + counts: &mut Counts, + ) -> Result<Option<StreamId>, Error> { + assert!(self.refused.is_none()); + + counts.peer().ensure_can_open(id, mode)?; + + let next_id = self.next_stream_id()?; + if id < next_id { + proto_err!(conn: "id ({:?}) < next_id ({:?})", id, next_id); + return Err(Error::library_go_away(Reason::PROTOCOL_ERROR)); + } + + self.next_stream_id = id.next_id(); + + if !counts.can_inc_num_recv_streams() { + self.refused = Some(id); + return Ok(None); + } + + Ok(Some(id)) + } + + /// Transition the stream state based on receiving headers + /// + /// The caller ensures that the frame represents headers and not trailers. + pub fn recv_headers( + &mut self, + frame: frame::Headers, + stream: &mut store::Ptr, + counts: &mut Counts, + ) -> Result<(), RecvHeaderBlockError<Option<frame::Headers>>> { + tracing::trace!("opening stream; init_window={}", self.init_window_sz); + let is_initial = stream.state.recv_open(&frame)?; + + if is_initial { + // TODO: be smarter about this logic + if frame.stream_id() > self.last_processed_id { + self.last_processed_id = frame.stream_id(); + } + + // Increment the number of concurrent streams + counts.inc_num_recv_streams(stream); + } + + if !stream.content_length.is_head() { + use super::stream::ContentLength; + use http::header; + + if let Some(content_length) = frame.fields().get(header::CONTENT_LENGTH) { + let content_length = match frame::parse_u64(content_length.as_bytes()) { + Ok(v) => v, + Err(()) => { + proto_err!(stream: "could not parse content-length; stream={:?}", stream.id); + return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR).into()); + } + }; + + stream.content_length = ContentLength::Remaining(content_length); + } + } + + if frame.is_over_size() { + // A frame is over size if the decoded header block was bigger than + // SETTINGS_MAX_HEADER_LIST_SIZE. + // + // > A server that receives a larger header block than it is willing + // > to handle can send an HTTP 431 (Request Header Fields Too + // > Large) status code [RFC6585]. A client can discard responses + // > that it cannot process. + // + // So, if peer is a server, we'll send a 431. In either case, + // an error is recorded, which will send a REFUSED_STREAM, + // since we don't want any of the data frames either. + tracing::debug!( + "stream error REQUEST_HEADER_FIELDS_TOO_LARGE -- \ + recv_headers: frame is over size; stream={:?}", + stream.id + ); + return if counts.peer().is_server() && is_initial { + let mut res = frame::Headers::new( + stream.id, + frame::Pseudo::response(::http::StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE), + HeaderMap::new(), + ); + res.set_end_stream(); + Err(RecvHeaderBlockError::Oversize(Some(res))) + } else { + Err(RecvHeaderBlockError::Oversize(None)) + }; + } + + let stream_id = frame.stream_id(); + let (pseudo, fields) = frame.into_parts(); + + if pseudo.protocol.is_some() { + if counts.peer().is_server() && !self.is_extended_connect_protocol_enabled { + proto_err!(stream: "cannot use :protocol if extended connect protocol is disabled; stream={:?}", stream.id); + return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR).into()); + } + } + + if !pseudo.is_informational() { + let message = counts + .peer() + .convert_poll_message(pseudo, fields, stream_id)?; + + // Push the frame onto the stream's recv buffer + stream + .pending_recv + .push_back(&mut self.buffer, Event::Headers(message)); + stream.notify_recv(); + } + + // Only servers can receive a headers frame that initiates the stream. + // This is verified in `Streams` before calling this function. + if counts.peer().is_server() { + self.pending_accept.push(stream); + } + + Ok(()) + } + + /// Called by the server to get the request + /// + /// TODO: Should this fn return `Result`? + pub fn take_request(&mut self, stream: &mut store::Ptr) -> Request<()> { + use super::peer::PollMessage::*; + + match stream.pending_recv.pop_front(&mut self.buffer) { + Some(Event::Headers(Server(request))) => request, + _ => panic!(), + } + } + + /// Called by the client to get pushed response + pub fn poll_pushed( + &mut self, + cx: &Context, + stream: &mut store::Ptr, + ) -> Poll<Option<Result<(Request<()>, store::Key), proto::Error>>> { + use super::peer::PollMessage::*; + + let mut ppp = stream.pending_push_promises.take(); + let pushed = ppp.pop(stream.store_mut()).map(|mut pushed| { + match pushed.pending_recv.pop_front(&mut self.buffer) { + Some(Event::Headers(Server(headers))) => (headers, pushed.key()), + // When frames are pushed into the queue, it is verified that + // the first frame is a HEADERS frame. + _ => panic!("Headers not set on pushed stream"), + } + }); + stream.pending_push_promises = ppp; + if let Some(p) = pushed { + Poll::Ready(Some(Ok(p))) + } else { + let is_open = stream.state.ensure_recv_open()?; + + if is_open { + stream.recv_task = Some(cx.waker().clone()); + Poll::Pending + } else { + Poll::Ready(None) + } + } + } + + /// Called by the client to get the response + pub fn poll_response( + &mut self, + cx: &Context, + stream: &mut store::Ptr, + ) -> Poll<Result<Response<()>, proto::Error>> { + use super::peer::PollMessage::*; + + // If the buffer is not empty, then the first frame must be a HEADERS + // frame or the user violated the contract. + match stream.pending_recv.pop_front(&mut self.buffer) { + Some(Event::Headers(Client(response))) => Poll::Ready(Ok(response)), + Some(_) => panic!("poll_response called after response returned"), + None => { + stream.state.ensure_recv_open()?; + + stream.recv_task = Some(cx.waker().clone()); + Poll::Pending + } + } + } + + /// Transition the stream based on receiving trailers + pub fn recv_trailers( + &mut self, + frame: frame::Headers, + stream: &mut store::Ptr, + ) -> Result<(), Error> { + // Transition the state + stream.state.recv_close()?; + + if stream.ensure_content_length_zero().is_err() { + proto_err!(stream: "recv_trailers: content-length is not zero; stream={:?};", stream.id); + return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR)); + } + + let trailers = frame.into_fields(); + + // Push the frame onto the stream's recv buffer + stream + .pending_recv + .push_back(&mut self.buffer, Event::Trailers(trailers)); + stream.notify_recv(); + + Ok(()) + } + + /// Releases capacity of the connection + pub fn release_connection_capacity(&mut self, capacity: WindowSize, task: &mut Option<Waker>) { + tracing::trace!( + "release_connection_capacity; size={}, connection in_flight_data={}", + capacity, + self.in_flight_data, + ); + + // Decrement in-flight data + self.in_flight_data -= capacity; + + // Assign capacity to connection + self.flow.assign_capacity(capacity); + + if self.flow.unclaimed_capacity().is_some() { + if let Some(task) = task.take() { + task.wake(); + } + } + } + + /// Releases capacity back to the connection & stream + pub fn release_capacity( + &mut self, + capacity: WindowSize, + stream: &mut store::Ptr, + task: &mut Option<Waker>, + ) -> Result<(), UserError> { + tracing::trace!("release_capacity; size={}", capacity); + + if capacity > stream.in_flight_recv_data { + return Err(UserError::ReleaseCapacityTooBig); + } + + self.release_connection_capacity(capacity, task); + + // Decrement in-flight data + stream.in_flight_recv_data -= capacity; + + // Assign capacity to stream + stream.recv_flow.assign_capacity(capacity); + + if stream.recv_flow.unclaimed_capacity().is_some() { + // Queue the stream for sending the WINDOW_UPDATE frame. + self.pending_window_updates.push(stream); + + if let Some(task) = task.take() { + task.wake(); + } + } + + Ok(()) + } + + /// Release any unclaimed capacity for a closed stream. + pub fn release_closed_capacity(&mut self, stream: &mut store::Ptr, task: &mut Option<Waker>) { + debug_assert_eq!(stream.ref_count, 0); + + if stream.in_flight_recv_data == 0 { + return; + } + + tracing::trace!( + "auto-release closed stream ({:?}) capacity: {:?}", + stream.id, + stream.in_flight_recv_data, + ); + + self.release_connection_capacity(stream.in_flight_recv_data, task); + stream.in_flight_recv_data = 0; + + self.clear_recv_buffer(stream); + } + + /// Set the "target" connection window size. + /// + /// By default, all new connections start with 64kb of window size. As + /// streams used and release capacity, we will send WINDOW_UPDATEs for the + /// connection to bring it back up to the initial "target". + /// + /// Setting a target means that we will try to tell the peer about + /// WINDOW_UPDATEs so the peer knows it has about `target` window to use + /// for the whole connection. + /// + /// The `task` is an optional parked task for the `Connection` that might + /// be blocked on needing more window capacity. + pub fn set_target_connection_window(&mut self, target: WindowSize, task: &mut Option<Waker>) { + tracing::trace!( + "set_target_connection_window; target={}; available={}, reserved={}", + target, + self.flow.available(), + self.in_flight_data, + ); + + // The current target connection window is our `available` plus any + // in-flight data reserved by streams. + // + // Update the flow controller with the difference between the new + // target and the current target. + let current = (self.flow.available() + self.in_flight_data).checked_size(); + if target > current { + self.flow.assign_capacity(target - current); + } else { + self.flow.claim_capacity(current - target); + } + + // If changing the target capacity means we gained a bunch of capacity, + // enough that we went over the update threshold, then schedule sending + // a connection WINDOW_UPDATE. + if self.flow.unclaimed_capacity().is_some() { + if let Some(task) = task.take() { + task.wake(); + } + } + } + + pub(crate) fn apply_local_settings( + &mut self, + settings: &frame::Settings, + store: &mut Store, + ) -> Result<(), proto::Error> { + if let Some(val) = settings.is_extended_connect_protocol_enabled() { + self.is_extended_connect_protocol_enabled = val; + } + + if let Some(target) = settings.initial_window_size() { + let old_sz = self.init_window_sz; + self.init_window_sz = target; + + tracing::trace!("update_initial_window_size; new={}; old={}", target, old_sz,); + + // Per RFC 7540 ยง6.9.2: + // + // In addition to changing the flow-control window for streams that are + // not yet active, a SETTINGS frame can alter the initial flow-control + // window size for streams with active flow-control windows (that is, + // streams in the "open" or "half-closed (remote)" state). When the + // value of SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST adjust + // the size of all stream flow-control windows that it maintains by the + // difference between the new value and the old value. + // + // A change to `SETTINGS_INITIAL_WINDOW_SIZE` can cause the available + // space in a flow-control window to become negative. A sender MUST + // track the negative flow-control window and MUST NOT send new + // flow-controlled frames until it receives WINDOW_UPDATE frames that + // cause the flow-control window to become positive. + + if target < old_sz { + // We must decrease the (local) window on every open stream. + let dec = old_sz - target; + tracing::trace!("decrementing all windows; dec={}", dec); + + store.for_each(|mut stream| { + stream.recv_flow.dec_recv_window(dec); + }) + } else if target > old_sz { + // We must increase the (local) window on every open stream. + let inc = target - old_sz; + tracing::trace!("incrementing all windows; inc={}", inc); + store.try_for_each(|mut stream| { + // XXX: Shouldn't the peer have already noticed our + // overflow and sent us a GOAWAY? + stream + .recv_flow + .inc_window(inc) + .map_err(proto::Error::library_go_away)?; + stream.recv_flow.assign_capacity(inc); + Ok::<_, proto::Error>(()) + })?; + } + } + + Ok(()) + } + + pub fn is_end_stream(&self, stream: &store::Ptr) -> bool { + if !stream.state.is_recv_closed() { + return false; + } + + stream.pending_recv.is_empty() + } + + pub fn recv_data(&mut self, frame: frame::Data, stream: &mut store::Ptr) -> Result<(), Error> { + let sz = frame.payload().len(); + + // This should have been enforced at the codec::FramedRead layer, so + // this is just a sanity check. + assert!(sz <= MAX_WINDOW_SIZE as usize); + + let sz = sz as WindowSize; + + let is_ignoring_frame = stream.state.is_local_reset(); + + if !is_ignoring_frame && !stream.state.is_recv_streaming() { + // TODO: There are cases where this can be a stream error of + // STREAM_CLOSED instead... + + // Receiving a DATA frame when not expecting one is a protocol + // error. + proto_err!(conn: "unexpected DATA frame; stream={:?}", stream.id); + return Err(Error::library_go_away(Reason::PROTOCOL_ERROR)); + } + + tracing::trace!( + "recv_data; size={}; connection={}; stream={}", + sz, + self.flow.window_size(), + stream.recv_flow.window_size() + ); + + if is_ignoring_frame { + tracing::trace!( + "recv_data; frame ignored on locally reset {:?} for some time", + stream.id, + ); + return Ok(self.ignore_data(sz)?); + } + + // Ensure that there is enough capacity on the connection before acting + // on the stream. + self.consume_connection_window(sz)?; + + if stream.recv_flow.window_size() < sz { + // http://httpwg.org/specs/rfc7540.html#WINDOW_UPDATE + // > A receiver MAY respond with a stream error (Section 5.4.2) or + // > connection error (Section 5.4.1) of type FLOW_CONTROL_ERROR if + // > it is unable to accept a frame. + // + // So, for violating the **stream** window, we can send either a + // stream or connection error. We've opted to send a stream + // error. + return Err(Error::library_reset(stream.id, Reason::FLOW_CONTROL_ERROR)); + } + + if stream.dec_content_length(frame.payload().len()).is_err() { + proto_err!(stream: + "recv_data: content-length overflow; stream={:?}; len={:?}", + stream.id, + frame.payload().len(), + ); + return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR)); + } + + if frame.is_end_stream() { + if stream.ensure_content_length_zero().is_err() { + proto_err!(stream: + "recv_data: content-length underflow; stream={:?}; len={:?}", + stream.id, + frame.payload().len(), + ); + return Err(Error::library_reset(stream.id, Reason::PROTOCOL_ERROR)); + } + + if stream.state.recv_close().is_err() { + proto_err!(conn: "recv_data: failed to transition to closed state; stream={:?}", stream.id); + return Err(Error::library_go_away(Reason::PROTOCOL_ERROR).into()); + } + } + + // Update stream level flow control + stream.recv_flow.send_data(sz); + + // Track the data as in-flight + stream.in_flight_recv_data += sz; + + let event = Event::Data(frame.into_payload()); + + // Push the frame onto the recv buffer + stream.pending_recv.push_back(&mut self.buffer, event); + stream.notify_recv(); + + Ok(()) + } + + pub fn ignore_data(&mut self, sz: WindowSize) -> Result<(), Error> { + // Ensure that there is enough capacity on the connection... + self.consume_connection_window(sz)?; + + // Since we are ignoring this frame, + // we aren't returning the frame to the user. That means they + // have no way to release the capacity back to the connection. So + // we have to release it automatically. + // + // This call doesn't send a WINDOW_UPDATE immediately, just marks + // the capacity as available to be reclaimed. When the available + // capacity meets a threshold, a WINDOW_UPDATE is then sent. + self.release_connection_capacity(sz, &mut None); + Ok(()) + } + + pub fn consume_connection_window(&mut self, sz: WindowSize) -> Result<(), Error> { + if self.flow.window_size() < sz { + tracing::debug!( + "connection error FLOW_CONTROL_ERROR -- window_size ({:?}) < sz ({:?});", + self.flow.window_size(), + sz, + ); + return Err(Error::library_go_away(Reason::FLOW_CONTROL_ERROR)); + } + + // Update connection level flow control + self.flow.send_data(sz); + + // Track the data as in-flight + self.in_flight_data += sz; + Ok(()) + } + + pub fn recv_push_promise( + &mut self, + frame: frame::PushPromise, + stream: &mut store::Ptr, + ) -> Result<(), Error> { + stream.state.reserve_remote()?; + if frame.is_over_size() { + // A frame is over size if the decoded header block was bigger than + // SETTINGS_MAX_HEADER_LIST_SIZE. + // + // > A server that receives a larger header block than it is willing + // > to handle can send an HTTP 431 (Request Header Fields Too + // > Large) status code [RFC6585]. A client can discard responses + // > that it cannot process. + // + // So, if peer is a server, we'll send a 431. In either case, + // an error is recorded, which will send a REFUSED_STREAM, + // since we don't want any of the data frames either. + tracing::debug!( + "stream error REFUSED_STREAM -- recv_push_promise: \ + headers frame is over size; promised_id={:?};", + frame.promised_id(), + ); + return Err(Error::library_reset( + frame.promised_id(), + Reason::REFUSED_STREAM, + )); + } + + let promised_id = frame.promised_id(); + let (pseudo, fields) = frame.into_parts(); + let req = crate::server::Peer::convert_poll_message(pseudo, fields, promised_id)?; + + if let Err(e) = frame::PushPromise::validate_request(&req) { + use PushPromiseHeaderError::*; + match e { + NotSafeAndCacheable => proto_err!( + stream: + "recv_push_promise: method {} is not safe and cacheable; promised_id={:?}", + req.method(), + promised_id, + ), + InvalidContentLength(e) => proto_err!( + stream: + "recv_push_promise; promised request has invalid content-length {:?}; promised_id={:?}", + e, + promised_id, + ), + } + return Err(Error::library_reset(promised_id, Reason::PROTOCOL_ERROR)); + } + + use super::peer::PollMessage::*; + stream + .pending_recv + .push_back(&mut self.buffer, Event::Headers(Server(req))); + stream.notify_recv(); + Ok(()) + } + + /// Ensures that `id` is not in the `Idle` state. + pub fn ensure_not_idle(&self, id: StreamId) -> Result<(), Reason> { + if let Ok(next) = self.next_stream_id { + if id >= next { + tracing::debug!( + "stream ID implicitly closed, PROTOCOL_ERROR; stream={:?}", + id + ); + return Err(Reason::PROTOCOL_ERROR); + } + } + // if next_stream_id is overflowed, that's ok. + + Ok(()) + } + + /// Handle remote sending an explicit RST_STREAM. + pub fn recv_reset(&mut self, frame: frame::Reset, stream: &mut Stream) { + // Notify the stream + stream.state.recv_reset(frame, stream.is_pending_send); + + stream.notify_send(); + stream.notify_recv(); + } + + /// Handle a connection-level error + pub fn handle_error(&mut self, err: &proto::Error, stream: &mut Stream) { + // Receive an error + stream.state.handle_error(err); + + // If a receiver is waiting, notify it + stream.notify_send(); + stream.notify_recv(); + } + + pub fn go_away(&mut self, last_processed_id: StreamId) { + assert!(self.max_stream_id >= last_processed_id); + self.max_stream_id = last_processed_id; + } + + pub fn recv_eof(&mut self, stream: &mut Stream) { + stream.state.recv_eof(); + stream.notify_send(); + stream.notify_recv(); + } + + pub(super) fn clear_recv_buffer(&mut self, stream: &mut Stream) { + while let Some(_) = stream.pending_recv.pop_front(&mut self.buffer) { + // drop it + } + } + + /// Get the max ID of streams we can receive. + /// + /// This gets lowered if we send a GOAWAY frame. + pub fn max_stream_id(&self) -> StreamId { + self.max_stream_id + } + + pub fn next_stream_id(&self) -> Result<StreamId, Error> { + if let Ok(id) = self.next_stream_id { + Ok(id) + } else { + Err(Error::library_go_away(Reason::PROTOCOL_ERROR)) + } + } + + pub fn may_have_created_stream(&self, id: StreamId) -> bool { + if let Ok(next_id) = self.next_stream_id { + // Peer::is_local_init should have been called beforehand + debug_assert_eq!(id.is_server_initiated(), next_id.is_server_initiated(),); + id < next_id + } else { + true + } + } + + pub(super) fn maybe_reset_next_stream_id(&mut self, id: StreamId) { + if let Ok(next_id) = self.next_stream_id { + // !Peer::is_local_init should have been called beforehand + debug_assert_eq!(id.is_server_initiated(), next_id.is_server_initiated()); + if id >= next_id { + self.next_stream_id = id.next_id(); + } + } + } + + /// Returns true if the remote peer can reserve a stream with the given ID. + pub fn ensure_can_reserve(&self) -> Result<(), Error> { + if !self.is_push_enabled { + proto_err!(conn: "recv_push_promise: push is disabled"); + return Err(Error::library_go_away(Reason::PROTOCOL_ERROR)); + } + + Ok(()) + } + + /// Add a locally reset stream to queue to be eventually reaped. + pub fn enqueue_reset_expiration(&mut self, stream: &mut store::Ptr, counts: &mut Counts) { + if !stream.state.is_local_reset() || stream.is_pending_reset_expiration() { + return; + } + + tracing::trace!("enqueue_reset_expiration; {:?}", stream.id); + + if !counts.can_inc_num_reset_streams() { + // try to evict 1 stream if possible + // if max allow is 0, this won't be able to evict, + // and then we'll just bail after + if let Some(evicted) = self.pending_reset_expired.pop(stream.store_mut()) { + counts.transition_after(evicted, true); + } + } + + if counts.can_inc_num_reset_streams() { + counts.inc_num_reset_streams(); + self.pending_reset_expired.push(stream); + } + } + + /// Send any pending refusals. + pub fn send_pending_refusal<T, B>( + &mut self, + cx: &mut Context, + dst: &mut Codec<T, Prioritized<B>>, + ) -> Poll<io::Result<()>> + where + T: AsyncWrite + Unpin, + B: Buf, + { + if let Some(stream_id) = self.refused { + ready!(dst.poll_ready(cx))?; + + // Create the RST_STREAM frame + let frame = frame::Reset::new(stream_id, Reason::REFUSED_STREAM); + + // Buffer the frame + dst.buffer(frame.into()).expect("invalid RST_STREAM frame"); + } + + self.refused = None; + + Poll::Ready(Ok(())) + } + + pub fn clear_expired_reset_streams(&mut self, store: &mut Store, counts: &mut Counts) { + if !self.pending_reset_expired.is_empty() { + let now = Instant::now(); + let reset_duration = self.reset_duration; + while let Some(stream) = self.pending_reset_expired.pop_if(store, |stream| { + let reset_at = stream.reset_at.expect("reset_at must be set if in queue"); + // rust-lang/rust#86470 tracks a bug in the standard library where `Instant` + // subtraction can panic (because, on some platforms, `Instant` isn't actually + // monotonic). We use a saturating operation to avoid this panic here. + now.saturating_duration_since(reset_at) > reset_duration + }) { + counts.transition_after(stream, true); + } + } + } + + pub fn clear_queues( + &mut self, + clear_pending_accept: bool, + store: &mut Store, + counts: &mut Counts, + ) { + self.clear_stream_window_update_queue(store, counts); + self.clear_all_reset_streams(store, counts); + + if clear_pending_accept { + self.clear_all_pending_accept(store, counts); + } + } + + fn clear_stream_window_update_queue(&mut self, store: &mut Store, counts: &mut Counts) { + while let Some(stream) = self.pending_window_updates.pop(store) { + counts.transition(stream, |_, stream| { + tracing::trace!("clear_stream_window_update_queue; stream={:?}", stream.id); + }) + } + } + + /// Called on EOF + fn clear_all_reset_streams(&mut self, store: &mut Store, counts: &mut Counts) { + while let Some(stream) = self.pending_reset_expired.pop(store) { + counts.transition_after(stream, true); + } + } + + fn clear_all_pending_accept(&mut self, store: &mut Store, counts: &mut Counts) { + while let Some(stream) = self.pending_accept.pop(store) { + counts.transition_after(stream, false); + } + } + + pub fn poll_complete<T, B>( + &mut self, + cx: &mut Context, + store: &mut Store, + counts: &mut Counts, + dst: &mut Codec<T, Prioritized<B>>, + ) -> Poll<io::Result<()>> + where + T: AsyncWrite + Unpin, + B: Buf, + { + // Send any pending connection level window updates + ready!(self.send_connection_window_update(cx, dst))?; + + // Send any pending stream level window updates + ready!(self.send_stream_window_updates(cx, store, counts, dst))?; + + Poll::Ready(Ok(())) + } + + /// Send connection level window update + fn send_connection_window_update<T, B>( + &mut self, + cx: &mut Context, + dst: &mut Codec<T, Prioritized<B>>, + ) -> Poll<io::Result<()>> + where + T: AsyncWrite + Unpin, + B: Buf, + { + if let Some(incr) = self.flow.unclaimed_capacity() { + let frame = frame::WindowUpdate::new(StreamId::zero(), incr); + + // Ensure the codec has capacity + ready!(dst.poll_ready(cx))?; + + // Buffer the WINDOW_UPDATE frame + dst.buffer(frame.into()) + .expect("invalid WINDOW_UPDATE frame"); + + // Update flow control + self.flow + .inc_window(incr) + .expect("unexpected flow control state"); + } + + Poll::Ready(Ok(())) + } + + /// Send stream level window update + pub fn send_stream_window_updates<T, B>( + &mut self, + cx: &mut Context, + store: &mut Store, + counts: &mut Counts, + dst: &mut Codec<T, Prioritized<B>>, + ) -> Poll<io::Result<()>> + where + T: AsyncWrite + Unpin, + B: Buf, + { + loop { + // Ensure the codec has capacity + ready!(dst.poll_ready(cx))?; + + // Get the next stream + let stream = match self.pending_window_updates.pop(store) { + Some(stream) => stream, + None => return Poll::Ready(Ok(())), + }; + + counts.transition(stream, |_, stream| { + tracing::trace!("pending_window_updates -- pop; stream={:?}", stream.id); + debug_assert!(!stream.is_pending_window_update); + + if !stream.state.is_recv_streaming() { + // No need to send window updates on the stream if the stream is + // no longer receiving data. + // + // TODO: is this correct? We could possibly send a window + // update on a ReservedRemote stream if we already know + // we want to stream the data faster... + return; + } + + // TODO: de-dup + if let Some(incr) = stream.recv_flow.unclaimed_capacity() { + // Create the WINDOW_UPDATE frame + let frame = frame::WindowUpdate::new(stream.id, incr); + + // Buffer it + dst.buffer(frame.into()) + .expect("invalid WINDOW_UPDATE frame"); + + // Update flow control + stream + .recv_flow + .inc_window(incr) + .expect("unexpected flow control state"); + } + }) + } + } + + pub fn next_incoming(&mut self, store: &mut Store) -> Option<store::Key> { + self.pending_accept.pop(store).map(|ptr| ptr.key()) + } + + pub fn poll_data( + &mut self, + cx: &Context, + stream: &mut Stream, + ) -> Poll<Option<Result<Bytes, proto::Error>>> { + // TODO: Return error when the stream is reset + match stream.pending_recv.pop_front(&mut self.buffer) { + Some(Event::Data(payload)) => Poll::Ready(Some(Ok(payload))), + Some(event) => { + // Frame is trailer + stream.pending_recv.push_front(&mut self.buffer, event); + + // Notify the recv task. This is done just in case + // `poll_trailers` was called. + // + // It is very likely that `notify_recv` will just be a no-op (as + // the task will be None), so this isn't really much of a + // performance concern. It also means we don't have to track + // state to see if `poll_trailers` was called before `poll_data` + // returned `None`. + stream.notify_recv(); + + // No more data frames + Poll::Ready(None) + } + None => self.schedule_recv(cx, stream), + } + } + + pub fn poll_trailers( + &mut self, + cx: &Context, + stream: &mut Stream, + ) -> Poll<Option<Result<HeaderMap, proto::Error>>> { + match stream.pending_recv.pop_front(&mut self.buffer) { + Some(Event::Trailers(trailers)) => Poll::Ready(Some(Ok(trailers))), + Some(event) => { + // Frame is not trailers.. not ready to poll trailers yet. + stream.pending_recv.push_front(&mut self.buffer, event); + + Poll::Pending + } + None => self.schedule_recv(cx, stream), + } + } + + fn schedule_recv<T>( + &mut self, + cx: &Context, + stream: &mut Stream, + ) -> Poll<Option<Result<T, proto::Error>>> { + if stream.state.ensure_recv_open()? { + // Request to get notified once more frames arrive + stream.recv_task = Some(cx.waker().clone()); + Poll::Pending + } else { + // No more frames will be received + Poll::Ready(None) + } + } +} + +// ===== impl Open ===== + +impl Open { + pub fn is_push_promise(&self) -> bool { + use self::Open::*; + + match *self { + PushPromise => true, + _ => false, + } + } +} + +// ===== impl RecvHeaderBlockError ===== + +impl<T> From<Error> for RecvHeaderBlockError<T> { + fn from(err: Error) -> Self { + RecvHeaderBlockError::State(err) + } +} |