diff options
Diffstat (limited to 'go/vendor/google.golang.org/grpc/transport/http2_client.go')
| -rw-r--r-- | go/vendor/google.golang.org/grpc/transport/http2_client.go | 1245 |
1 files changed, 1245 insertions, 0 deletions
diff --git a/go/vendor/google.golang.org/grpc/transport/http2_client.go b/go/vendor/google.golang.org/grpc/transport/http2_client.go new file mode 100644 index 0000000..486d4a1 --- /dev/null +++ b/go/vendor/google.golang.org/grpc/transport/http2_client.go @@ -0,0 +1,1245 @@ +/* + * + * Copyright 2014, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +package transport + +import ( + "bytes" + "io" + "math" + "net" + "strings" + "sync" + "sync/atomic" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/http2" + "golang.org/x/net/http2/hpack" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/credentials" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/keepalive" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/peer" + "google.golang.org/grpc/stats" + "google.golang.org/grpc/status" +) + +// http2Client implements the ClientTransport interface with HTTP2. +type http2Client struct { + ctx context.Context + target string // server name/addr + userAgent string + md interface{} + conn net.Conn // underlying communication channel + remoteAddr net.Addr + localAddr net.Addr + authInfo credentials.AuthInfo // auth info about the connection + nextID uint32 // the next stream ID to be used + + // writableChan synchronizes write access to the transport. + // A writer acquires the write lock by sending a value on writableChan + // and releases it by receiving from writableChan. + writableChan chan int + // shutdownChan is closed when Close is called. + // Blocking operations should select on shutdownChan to avoid + // blocking forever after Close. + // TODO(zhaoq): Maybe have a channel context? + shutdownChan chan struct{} + // errorChan is closed to notify the I/O error to the caller. + errorChan chan struct{} + // goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor) + // that the server sent GoAway on this transport. + goAway chan struct{} + // awakenKeepalive is used to wake up keepalive when after it has gone dormant. + awakenKeepalive chan struct{} + + framer *framer + hBuf *bytes.Buffer // the buffer for HPACK encoding + hEnc *hpack.Encoder // HPACK encoder + + // controlBuf delivers all the control related tasks (e.g., window + // updates, reset streams, and various settings) to the controller. + controlBuf *recvBuffer + fc *inFlow + // sendQuotaPool provides flow control to outbound message. + sendQuotaPool *quotaPool + // streamsQuota limits the max number of concurrent streams. + streamsQuota *quotaPool + + // The scheme used: https if TLS is on, http otherwise. + scheme string + + creds []credentials.PerRPCCredentials + + // Boolean to keep track of reading activity on transport. + // 1 is true and 0 is false. + activity uint32 // Accessed atomically. + kp keepalive.ClientParameters + + statsHandler stats.Handler + + mu sync.Mutex // guard the following variables + state transportState // the state of underlying connection + activeStreams map[uint32]*Stream + // The max number of concurrent streams + maxStreams int + // the per-stream outbound flow control window size set by the peer. + streamSendQuota uint32 + // goAwayID records the Last-Stream-ID in the GoAway frame from the server. + goAwayID uint32 + // prevGoAway ID records the Last-Stream-ID in the previous GOAway frame. + prevGoAwayID uint32 + // goAwayReason records the http2.ErrCode and debug data received with the + // GoAway frame. + goAwayReason GoAwayReason +} + +func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) { + if fn != nil { + return fn(ctx, addr) + } + return dialContext(ctx, "tcp", addr) +} + +func isTemporary(err error) bool { + switch err { + case io.EOF: + // Connection closures may be resolved upon retry, and are thus + // treated as temporary. + return true + case context.DeadlineExceeded: + // In Go 1.7, context.DeadlineExceeded implements Timeout(), and this + // special case is not needed. Until then, we need to keep this + // clause. + return true + } + + switch err := err.(type) { + case interface { + Temporary() bool + }: + return err.Temporary() + case interface { + Timeout() bool + }: + // Timeouts may be resolved upon retry, and are thus treated as + // temporary. + return err.Timeout() + } + return false +} + +// newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2 +// and starts to receive messages on it. Non-nil error returns if construction +// fails. +func newHTTP2Client(ctx context.Context, addr TargetInfo, opts ConnectOptions) (_ ClientTransport, err error) { + scheme := "http" + conn, err := dial(ctx, opts.Dialer, addr.Addr) + if err != nil { + if opts.FailOnNonTempDialError { + return nil, connectionErrorf(isTemporary(err), err, "transport: %v", err) + } + return nil, connectionErrorf(true, err, "transport: %v", err) + } + // Any further errors will close the underlying connection + defer func(conn net.Conn) { + if err != nil { + conn.Close() + } + }(conn) + var authInfo credentials.AuthInfo + if creds := opts.TransportCredentials; creds != nil { + scheme = "https" + conn, authInfo, err = creds.ClientHandshake(ctx, addr.Addr, conn) + if err != nil { + // Credentials handshake errors are typically considered permanent + // to avoid retrying on e.g. bad certificates. + temp := isTemporary(err) + return nil, connectionErrorf(temp, err, "transport: %v", err) + } + } + kp := opts.KeepaliveParams + // Validate keepalive parameters. + if kp.Time == 0 { + kp.Time = defaultClientKeepaliveTime + } + if kp.Timeout == 0 { + kp.Timeout = defaultClientKeepaliveTimeout + } + var buf bytes.Buffer + t := &http2Client{ + ctx: ctx, + target: addr.Addr, + userAgent: opts.UserAgent, + md: addr.Metadata, + conn: conn, + remoteAddr: conn.RemoteAddr(), + localAddr: conn.LocalAddr(), + authInfo: authInfo, + // The client initiated stream id is odd starting from 1. + nextID: 1, + writableChan: make(chan int, 1), + shutdownChan: make(chan struct{}), + errorChan: make(chan struct{}), + goAway: make(chan struct{}), + awakenKeepalive: make(chan struct{}, 1), + framer: newFramer(conn), + hBuf: &buf, + hEnc: hpack.NewEncoder(&buf), + controlBuf: newRecvBuffer(), + fc: &inFlow{limit: initialConnWindowSize}, + sendQuotaPool: newQuotaPool(defaultWindowSize), + scheme: scheme, + state: reachable, + activeStreams: make(map[uint32]*Stream), + creds: opts.PerRPCCredentials, + maxStreams: defaultMaxStreamsClient, + streamsQuota: newQuotaPool(defaultMaxStreamsClient), + streamSendQuota: defaultWindowSize, + kp: kp, + statsHandler: opts.StatsHandler, + } + // Make sure awakenKeepalive can't be written upon. + // keepalive routine will make it writable, if need be. + t.awakenKeepalive <- struct{}{} + if t.statsHandler != nil { + t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{ + RemoteAddr: t.remoteAddr, + LocalAddr: t.localAddr, + }) + connBegin := &stats.ConnBegin{ + Client: true, + } + t.statsHandler.HandleConn(t.ctx, connBegin) + } + // Start the reader goroutine for incoming message. Each transport has + // a dedicated goroutine which reads HTTP2 frame from network. Then it + // dispatches the frame to the corresponding stream entity. + go t.reader() + // Send connection preface to server. + n, err := t.conn.Write(clientPreface) + if err != nil { + t.Close() + return nil, connectionErrorf(true, err, "transport: %v", err) + } + if n != len(clientPreface) { + t.Close() + return nil, connectionErrorf(true, err, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface)) + } + if initialWindowSize != defaultWindowSize { + err = t.framer.writeSettings(true, http2.Setting{ + ID: http2.SettingInitialWindowSize, + Val: uint32(initialWindowSize), + }) + } else { + err = t.framer.writeSettings(true) + } + if err != nil { + t.Close() + return nil, connectionErrorf(true, err, "transport: %v", err) + } + // Adjust the connection flow control window if needed. + if delta := uint32(initialConnWindowSize - defaultWindowSize); delta > 0 { + if err := t.framer.writeWindowUpdate(true, 0, delta); err != nil { + t.Close() + return nil, connectionErrorf(true, err, "transport: %v", err) + } + } + go t.controller() + if t.kp.Time != infinity { + go t.keepalive() + } + t.writableChan <- 0 + return t, nil +} + +func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream { + // TODO(zhaoq): Handle uint32 overflow of Stream.id. + s := &Stream{ + id: t.nextID, + done: make(chan struct{}), + goAway: make(chan struct{}), + method: callHdr.Method, + sendCompress: callHdr.SendCompress, + buf: newRecvBuffer(), + fc: &inFlow{limit: initialWindowSize}, + sendQuotaPool: newQuotaPool(int(t.streamSendQuota)), + headerChan: make(chan struct{}), + } + t.nextID += 2 + s.windowHandler = func(n int) { + t.updateWindow(s, uint32(n)) + } + // The client side stream context should have exactly the same life cycle with the user provided context. + // That means, s.ctx should be read-only. And s.ctx is done iff ctx is done. + // So we use the original context here instead of creating a copy. + s.ctx = ctx + s.dec = &recvBufferReader{ + ctx: s.ctx, + goAway: s.goAway, + recv: s.buf, + } + return s +} + +// NewStream creates a stream and registers it into the transport as "active" +// streams. +func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) { + pr := &peer.Peer{ + Addr: t.remoteAddr, + } + // Attach Auth info if there is any. + if t.authInfo != nil { + pr.AuthInfo = t.authInfo + } + userCtx := ctx + ctx = peer.NewContext(ctx, pr) + authData := make(map[string]string) + for _, c := range t.creds { + // Construct URI required to get auth request metadata. + var port string + if pos := strings.LastIndex(t.target, ":"); pos != -1 { + // Omit port if it is the default one. + if t.target[pos+1:] != "443" { + port = ":" + t.target[pos+1:] + } + } + pos := strings.LastIndex(callHdr.Method, "/") + if pos == -1 { + return nil, streamErrorf(codes.InvalidArgument, "transport: malformed method name: %q", callHdr.Method) + } + audience := "https://" + callHdr.Host + port + callHdr.Method[:pos] + data, err := c.GetRequestMetadata(ctx, audience) + if err != nil { + return nil, streamErrorf(codes.InvalidArgument, "transport: %v", err) + } + for k, v := range data { + authData[k] = v + } + } + t.mu.Lock() + if t.activeStreams == nil { + t.mu.Unlock() + return nil, ErrConnClosing + } + if t.state == draining { + t.mu.Unlock() + return nil, ErrStreamDrain + } + if t.state != reachable { + t.mu.Unlock() + return nil, ErrConnClosing + } + t.mu.Unlock() + sq, err := wait(ctx, nil, nil, t.shutdownChan, t.streamsQuota.acquire()) + if err != nil { + return nil, err + } + // Returns the quota balance back. + if sq > 1 { + t.streamsQuota.add(sq - 1) + } + if _, err := wait(ctx, nil, nil, t.shutdownChan, t.writableChan); err != nil { + // Return the quota back now because there is no stream returned to the caller. + if _, ok := err.(StreamError); ok { + t.streamsQuota.add(1) + } + return nil, err + } + t.mu.Lock() + if t.state == draining { + t.mu.Unlock() + t.streamsQuota.add(1) + // Need to make t writable again so that the rpc in flight can still proceed. + t.writableChan <- 0 + return nil, ErrStreamDrain + } + if t.state != reachable { + t.mu.Unlock() + return nil, ErrConnClosing + } + s := t.newStream(ctx, callHdr) + s.clientStatsCtx = userCtx + t.activeStreams[s.id] = s + // If the number of active streams change from 0 to 1, then check if keepalive + // has gone dormant. If so, wake it up. + if len(t.activeStreams) == 1 { + select { + case t.awakenKeepalive <- struct{}{}: + t.framer.writePing(false, false, [8]byte{}) + default: + } + } + + t.mu.Unlock() + + // HPACK encodes various headers. Note that once WriteField(...) is + // called, the corresponding headers/continuation frame has to be sent + // because hpack.Encoder is stateful. + t.hBuf.Reset() + t.hEnc.WriteField(hpack.HeaderField{Name: ":method", Value: "POST"}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":scheme", Value: t.scheme}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":path", Value: callHdr.Method}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":authority", Value: callHdr.Host}) + t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"}) + t.hEnc.WriteField(hpack.HeaderField{Name: "user-agent", Value: t.userAgent}) + t.hEnc.WriteField(hpack.HeaderField{Name: "te", Value: "trailers"}) + + if callHdr.SendCompress != "" { + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress}) + } + if dl, ok := ctx.Deadline(); ok { + // Send out timeout regardless its value. The server can detect timeout context by itself. + timeout := dl.Sub(time.Now()) + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-timeout", Value: encodeTimeout(timeout)}) + } + + for k, v := range authData { + // Capital header names are illegal in HTTP/2. + k = strings.ToLower(k) + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: v}) + } + var ( + hasMD bool + endHeaders bool + ) + if md, ok := metadata.FromOutgoingContext(ctx); ok { + hasMD = true + for k, v := range md { + // HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set. + if isReservedHeader(k) { + continue + } + for _, entry := range v { + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry}) + } + } + } + if md, ok := t.md.(*metadata.MD); ok { + for k, v := range *md { + if isReservedHeader(k) { + continue + } + for _, entry := range v { + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry}) + } + } + } + first := true + bufLen := t.hBuf.Len() + // Sends the headers in a single batch even when they span multiple frames. + for !endHeaders { + size := t.hBuf.Len() + if size > http2MaxFrameLen { + size = http2MaxFrameLen + } else { + endHeaders = true + } + var flush bool + if endHeaders && (hasMD || callHdr.Flush) { + flush = true + } + if first { + // Sends a HeadersFrame to server to start a new stream. + p := http2.HeadersFrameParam{ + StreamID: s.id, + BlockFragment: t.hBuf.Next(size), + EndStream: false, + EndHeaders: endHeaders, + } + // Do a force flush for the buffered frames iff it is the last headers frame + // and there is header metadata to be sent. Otherwise, there is flushing until + // the corresponding data frame is written. + err = t.framer.writeHeaders(flush, p) + first = false + } else { + // Sends Continuation frames for the leftover headers. + err = t.framer.writeContinuation(flush, s.id, endHeaders, t.hBuf.Next(size)) + } + if err != nil { + t.notifyError(err) + return nil, connectionErrorf(true, err, "transport: %v", err) + } + } + if t.statsHandler != nil { + outHeader := &stats.OutHeader{ + Client: true, + WireLength: bufLen, + FullMethod: callHdr.Method, + RemoteAddr: t.remoteAddr, + LocalAddr: t.localAddr, + Compression: callHdr.SendCompress, + } + t.statsHandler.HandleRPC(s.clientStatsCtx, outHeader) + } + t.writableChan <- 0 + return s, nil +} + +// CloseStream clears the footprint of a stream when the stream is not needed any more. +// This must not be executed in reader's goroutine. +func (t *http2Client) CloseStream(s *Stream, err error) { + t.mu.Lock() + if t.activeStreams == nil { + t.mu.Unlock() + return + } + delete(t.activeStreams, s.id) + if t.state == draining && len(t.activeStreams) == 0 { + // The transport is draining and s is the last live stream on t. + t.mu.Unlock() + t.Close() + return + } + t.mu.Unlock() + // rstStream is true in case the stream is being closed at the client-side + // and the server needs to be intimated about it by sending a RST_STREAM + // frame. + // To make sure this frame is written to the wire before the headers of the + // next stream waiting for streamsQuota, we add to streamsQuota pool only + // after having acquired the writableChan to send RST_STREAM out (look at + // the controller() routine). + var rstStream bool + var rstError http2.ErrCode + defer func() { + // In case, the client doesn't have to send RST_STREAM to server + // we can safely add back to streamsQuota pool now. + if !rstStream { + t.streamsQuota.add(1) + return + } + t.controlBuf.put(&resetStream{s.id, rstError}) + }() + s.mu.Lock() + rstStream = s.rstStream + rstError = s.rstError + if q := s.fc.resetPendingData(); q > 0 { + if n := t.fc.onRead(q); n > 0 { + t.controlBuf.put(&windowUpdate{0, n}) + } + } + if s.state == streamDone { + s.mu.Unlock() + return + } + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.state = streamDone + s.mu.Unlock() + if _, ok := err.(StreamError); ok { + rstStream = true + rstError = http2.ErrCodeCancel + } +} + +// Close kicks off the shutdown process of the transport. This should be called +// only once on a transport. Once it is called, the transport should not be +// accessed any more. +func (t *http2Client) Close() (err error) { + t.mu.Lock() + if t.state == closing { + t.mu.Unlock() + return + } + if t.state == reachable || t.state == draining { + close(t.errorChan) + } + t.state = closing + t.mu.Unlock() + close(t.shutdownChan) + err = t.conn.Close() + t.mu.Lock() + streams := t.activeStreams + t.activeStreams = nil + t.mu.Unlock() + // Notify all active streams. + for _, s := range streams { + s.mu.Lock() + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.mu.Unlock() + s.write(recvMsg{err: ErrConnClosing}) + } + if t.statsHandler != nil { + connEnd := &stats.ConnEnd{ + Client: true, + } + t.statsHandler.HandleConn(t.ctx, connEnd) + } + return +} + +func (t *http2Client) GracefulClose() error { + t.mu.Lock() + switch t.state { + case unreachable: + // The server may close the connection concurrently. t is not available for + // any streams. Close it now. + t.mu.Unlock() + t.Close() + return nil + case closing: + t.mu.Unlock() + return nil + } + // Notify the streams which were initiated after the server sent GOAWAY. + select { + case <-t.goAway: + n := t.prevGoAwayID + if n == 0 && t.nextID > 1 { + n = t.nextID - 2 + } + m := t.goAwayID + 2 + if m == 2 { + m = 1 + } + for i := m; i <= n; i += 2 { + if s, ok := t.activeStreams[i]; ok { + close(s.goAway) + } + } + default: + } + if t.state == draining { + t.mu.Unlock() + return nil + } + t.state = draining + active := len(t.activeStreams) + t.mu.Unlock() + if active == 0 { + return t.Close() + } + return nil +} + +// Write formats the data into HTTP2 data frame(s) and sends it out. The caller +// should proceed only if Write returns nil. +// TODO(zhaoq): opts.Delay is ignored in this implementation. Support it later +// if it improves the performance. +func (t *http2Client) Write(s *Stream, data []byte, opts *Options) error { + r := bytes.NewBuffer(data) + for { + var p []byte + if r.Len() > 0 { + size := http2MaxFrameLen + // Wait until the stream has some quota to send the data. + sq, err := wait(s.ctx, s.done, s.goAway, t.shutdownChan, s.sendQuotaPool.acquire()) + if err != nil { + return err + } + // Wait until the transport has some quota to send the data. + tq, err := wait(s.ctx, s.done, s.goAway, t.shutdownChan, t.sendQuotaPool.acquire()) + if err != nil { + return err + } + if sq < size { + size = sq + } + if tq < size { + size = tq + } + p = r.Next(size) + ps := len(p) + if ps < sq { + // Overbooked stream quota. Return it back. + s.sendQuotaPool.add(sq - ps) + } + if ps < tq { + // Overbooked transport quota. Return it back. + t.sendQuotaPool.add(tq - ps) + } + } + var ( + endStream bool + forceFlush bool + ) + if opts.Last && r.Len() == 0 { + endStream = true + } + // Indicate there is a writer who is about to write a data frame. + t.framer.adjustNumWriters(1) + // Got some quota. Try to acquire writing privilege on the transport. + if _, err := wait(s.ctx, s.done, s.goAway, t.shutdownChan, t.writableChan); err != nil { + if _, ok := err.(StreamError); ok || err == io.EOF { + // Return the connection quota back. + t.sendQuotaPool.add(len(p)) + } + if t.framer.adjustNumWriters(-1) == 0 { + // This writer is the last one in this batch and has the + // responsibility to flush the buffered frames. It queues + // a flush request to controlBuf instead of flushing directly + // in order to avoid the race with other writing or flushing. + t.controlBuf.put(&flushIO{}) + } + return err + } + select { + case <-s.ctx.Done(): + t.sendQuotaPool.add(len(p)) + if t.framer.adjustNumWriters(-1) == 0 { + t.controlBuf.put(&flushIO{}) + } + t.writableChan <- 0 + return ContextErr(s.ctx.Err()) + default: + } + if r.Len() == 0 && t.framer.adjustNumWriters(0) == 1 { + // Do a force flush iff this is last frame for the entire gRPC message + // and the caller is the only writer at this moment. + forceFlush = true + } + // If WriteData fails, all the pending streams will be handled + // by http2Client.Close(). No explicit CloseStream() needs to be + // invoked. + if err := t.framer.writeData(forceFlush, s.id, endStream, p); err != nil { + t.notifyError(err) + return connectionErrorf(true, err, "transport: %v", err) + } + if t.framer.adjustNumWriters(-1) == 0 { + t.framer.flushWrite() + } + t.writableChan <- 0 + if r.Len() == 0 { + break + } + } + if !opts.Last { + return nil + } + s.mu.Lock() + if s.state != streamDone { + s.state = streamWriteDone + } + s.mu.Unlock() + return nil +} + +func (t *http2Client) getStream(f http2.Frame) (*Stream, bool) { + t.mu.Lock() + defer t.mu.Unlock() + s, ok := t.activeStreams[f.Header().StreamID] + return s, ok +} + +// updateWindow adjusts the inbound quota for the stream and the transport. +// Window updates will deliver to the controller for sending when +// the cumulative quota exceeds the corresponding threshold. +func (t *http2Client) updateWindow(s *Stream, n uint32) { + s.mu.Lock() + defer s.mu.Unlock() + if s.state == streamDone { + return + } + if w := t.fc.onRead(n); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + if w := s.fc.onRead(n); w > 0 { + t.controlBuf.put(&windowUpdate{s.id, w}) + } +} + +func (t *http2Client) handleData(f *http2.DataFrame) { + size := f.Header().Length + if err := t.fc.onData(uint32(size)); err != nil { + t.notifyError(connectionErrorf(true, err, "%v", err)) + return + } + // Select the right stream to dispatch. + s, ok := t.getStream(f) + if !ok { + if w := t.fc.onRead(uint32(size)); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + return + } + if size > 0 { + if f.Header().Flags.Has(http2.FlagDataPadded) { + if w := t.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + } + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + // The stream has been closed. Release the corresponding quota. + if w := t.fc.onRead(uint32(size)); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + return + } + if err := s.fc.onData(uint32(size)); err != nil { + s.rstStream = true + s.rstError = http2.ErrCodeFlowControl + s.finish(status.New(codes.Internal, err.Error())) + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) + return + } + if f.Header().Flags.Has(http2.FlagDataPadded) { + if w := s.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 { + t.controlBuf.put(&windowUpdate{s.id, w}) + } + } + s.mu.Unlock() + // TODO(bradfitz, zhaoq): A copy is required here because there is no + // guarantee f.Data() is consumed before the arrival of next frame. + // Can this copy be eliminated? + if len(f.Data()) > 0 { + data := make([]byte, len(f.Data())) + copy(data, f.Data()) + s.write(recvMsg{data: data}) + } + } + // The server has closed the stream without sending trailers. Record that + // the read direction is closed, and set the status appropriately. + if f.FrameHeader.Flags.Has(http2.FlagDataEndStream) { + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + return + } + s.finish(status.New(codes.Internal, "server closed the stream without sending trailers")) + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) + } +} + +func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) { + s, ok := t.getStream(f) + if !ok { + return + } + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + return + } + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + statusCode, ok := http2ErrConvTab[http2.ErrCode(f.ErrCode)] + if !ok { + grpclog.Println("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error ", f.ErrCode) + statusCode = codes.Unknown + } + s.finish(status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %d", f.ErrCode)) + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) +} + +func (t *http2Client) handleSettings(f *http2.SettingsFrame) { + if f.IsAck() { + return + } + var ss []http2.Setting + f.ForeachSetting(func(s http2.Setting) error { + ss = append(ss, s) + return nil + }) + // The settings will be applied once the ack is sent. + t.controlBuf.put(&settings{ack: true, ss: ss}) +} + +func (t *http2Client) handlePing(f *http2.PingFrame) { + if f.IsAck() { // Do nothing. + return + } + pingAck := &ping{ack: true} + copy(pingAck.data[:], f.Data[:]) + t.controlBuf.put(pingAck) +} + +func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) { + if f.ErrCode == http2.ErrCodeEnhanceYourCalm { + grpclog.Printf("Client received GoAway with http2.ErrCodeEnhanceYourCalm.") + } + t.mu.Lock() + if t.state == reachable || t.state == draining { + if f.LastStreamID > 0 && f.LastStreamID%2 != 1 { + t.mu.Unlock() + t.notifyError(connectionErrorf(true, nil, "received illegal http2 GOAWAY frame: stream ID %d is even", f.LastStreamID)) + return + } + select { + case <-t.goAway: + id := t.goAwayID + // t.goAway has been closed (i.e.,multiple GoAways). + if id < f.LastStreamID { + t.mu.Unlock() + t.notifyError(connectionErrorf(true, nil, "received illegal http2 GOAWAY frame: previously recv GOAWAY frame with LastStramID %d, currently recv %d", id, f.LastStreamID)) + return + } + t.prevGoAwayID = id + t.goAwayID = f.LastStreamID + t.mu.Unlock() + return + default: + t.setGoAwayReason(f) + } + t.goAwayID = f.LastStreamID + close(t.goAway) + } + t.mu.Unlock() +} + +// setGoAwayReason sets the value of t.goAwayReason based +// on the GoAway frame received. +// It expects a lock on transport's mutext to be held by +// the caller. +func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) { + t.goAwayReason = NoReason + switch f.ErrCode { + case http2.ErrCodeEnhanceYourCalm: + if string(f.DebugData()) == "too_many_pings" { + t.goAwayReason = TooManyPings + } + } +} + +func (t *http2Client) GetGoAwayReason() GoAwayReason { + t.mu.Lock() + defer t.mu.Unlock() + return t.goAwayReason +} + +func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) { + id := f.Header().StreamID + incr := f.Increment + if id == 0 { + t.sendQuotaPool.add(int(incr)) + return + } + if s, ok := t.getStream(f); ok { + s.sendQuotaPool.add(int(incr)) + } +} + +// operateHeaders takes action on the decoded headers. +func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) { + s, ok := t.getStream(frame) + if !ok { + return + } + var state decodeState + for _, hf := range frame.Fields { + if err := state.processHeaderField(hf); err != nil { + s.mu.Lock() + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.mu.Unlock() + s.write(recvMsg{err: err}) + // Something wrong. Stops reading even when there is remaining. + return + } + } + + endStream := frame.StreamEnded() + var isHeader bool + defer func() { + if t.statsHandler != nil { + if isHeader { + inHeader := &stats.InHeader{ + Client: true, + WireLength: int(frame.Header().Length), + } + t.statsHandler.HandleRPC(s.clientStatsCtx, inHeader) + } else { + inTrailer := &stats.InTrailer{ + Client: true, + WireLength: int(frame.Header().Length), + } + t.statsHandler.HandleRPC(s.clientStatsCtx, inTrailer) + } + } + }() + + s.mu.Lock() + if !endStream { + s.recvCompress = state.encoding + } + if !s.headerDone { + if !endStream && len(state.mdata) > 0 { + s.header = state.mdata + } + close(s.headerChan) + s.headerDone = true + isHeader = true + } + if !endStream || s.state == streamDone { + s.mu.Unlock() + return + } + + if len(state.mdata) > 0 { + s.trailer = state.mdata + } + s.finish(state.status()) + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) +} + +func handleMalformedHTTP2(s *Stream, err error) { + s.mu.Lock() + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.mu.Unlock() + s.write(recvMsg{err: err}) +} + +// reader runs as a separate goroutine in charge of reading data from network +// connection. +// +// TODO(zhaoq): currently one reader per transport. Investigate whether this is +// optimal. +// TODO(zhaoq): Check the validity of the incoming frame sequence. +func (t *http2Client) reader() { + // Check the validity of server preface. + frame, err := t.framer.readFrame() + if err != nil { + t.notifyError(err) + return + } + atomic.CompareAndSwapUint32(&t.activity, 0, 1) + sf, ok := frame.(*http2.SettingsFrame) + if !ok { + t.notifyError(err) + return + } + t.handleSettings(sf) + + // loop to keep reading incoming messages on this transport. + for { + frame, err := t.framer.readFrame() + atomic.CompareAndSwapUint32(&t.activity, 0, 1) + if err != nil { + // Abort an active stream if the http2.Framer returns a + // http2.StreamError. This can happen only if the server's response + // is malformed http2. + if se, ok := err.(http2.StreamError); ok { + t.mu.Lock() + s := t.activeStreams[se.StreamID] + t.mu.Unlock() + if s != nil { + // use error detail to provide better err message + handleMalformedHTTP2(s, streamErrorf(http2ErrConvTab[se.Code], "%v", t.framer.errorDetail())) + } + continue + } else { + // Transport error. + t.notifyError(err) + return + } + } + switch frame := frame.(type) { + case *http2.MetaHeadersFrame: + t.operateHeaders(frame) + case *http2.DataFrame: + t.handleData(frame) + case *http2.RSTStreamFrame: + t.handleRSTStream(frame) + case *http2.SettingsFrame: + t.handleSettings(frame) + case *http2.PingFrame: + t.handlePing(frame) + case *http2.GoAwayFrame: + t.handleGoAway(frame) + case *http2.WindowUpdateFrame: + t.handleWindowUpdate(frame) + default: + grpclog.Printf("transport: http2Client.reader got unhandled frame type %v.", frame) + } + } +} + +func (t *http2Client) applySettings(ss []http2.Setting) { + for _, s := range ss { + switch s.ID { + case http2.SettingMaxConcurrentStreams: + // TODO(zhaoq): This is a hack to avoid significant refactoring of the + // code to deal with the unrealistic int32 overflow. Probably will try + // to find a better way to handle this later. + if s.Val > math.MaxInt32 { + s.Val = math.MaxInt32 + } + t.mu.Lock() + ms := t.maxStreams + t.maxStreams = int(s.Val) + t.mu.Unlock() + t.streamsQuota.add(int(s.Val) - ms) + case http2.SettingInitialWindowSize: + t.mu.Lock() + for _, stream := range t.activeStreams { + // Adjust the sending quota for each stream. + stream.sendQuotaPool.add(int(s.Val - t.streamSendQuota)) + } + t.streamSendQuota = s.Val + t.mu.Unlock() + } + } +} + +// controller running in a separate goroutine takes charge of sending control +// frames (e.g., window update, reset stream, setting, etc.) to the server. +func (t *http2Client) controller() { + for { + select { + case i := <-t.controlBuf.get(): + t.controlBuf.load() + select { + case <-t.writableChan: + switch i := i.(type) { + case *windowUpdate: + t.framer.writeWindowUpdate(true, i.streamID, i.increment) + case *settings: + if i.ack { + t.framer.writeSettingsAck(true) + t.applySettings(i.ss) + } else { + t.framer.writeSettings(true, i.ss...) + } + case *resetStream: + // If the server needs to be to intimated about stream closing, + // then we need to make sure the RST_STREAM frame is written to + // the wire before the headers of the next stream waiting on + // streamQuota. We ensure this by adding to the streamsQuota pool + // only after having acquired the writableChan to send RST_STREAM. + t.streamsQuota.add(1) + t.framer.writeRSTStream(true, i.streamID, i.code) + case *flushIO: + t.framer.flushWrite() + case *ping: + t.framer.writePing(true, i.ack, i.data) + default: + grpclog.Printf("transport: http2Client.controller got unexpected item type %v\n", i) + } + t.writableChan <- 0 + continue + case <-t.shutdownChan: + return + } + case <-t.shutdownChan: + return + } + } +} + +// keepalive running in a separate goroutune makes sure the connection is alive by sending pings. +func (t *http2Client) keepalive() { + p := &ping{data: [8]byte{}} + timer := time.NewTimer(t.kp.Time) + for { + select { + case <-timer.C: + if atomic.CompareAndSwapUint32(&t.activity, 1, 0) { + timer.Reset(t.kp.Time) + continue + } + // Check if keepalive should go dormant. + t.mu.Lock() + if len(t.activeStreams) < 1 && !t.kp.PermitWithoutStream { + // Make awakenKeepalive writable. + <-t.awakenKeepalive + t.mu.Unlock() + select { + case <-t.awakenKeepalive: + // If the control gets here a ping has been sent + // need to reset the timer with keepalive.Timeout. + case <-t.shutdownChan: + return + } + } else { + t.mu.Unlock() + // Send ping. + t.controlBuf.put(p) + } + + // By the time control gets here a ping has been sent one way or the other. + timer.Reset(t.kp.Timeout) + select { + case <-timer.C: + if atomic.CompareAndSwapUint32(&t.activity, 1, 0) { + timer.Reset(t.kp.Time) + continue + } + t.Close() + return + case <-t.shutdownChan: + if !timer.Stop() { + <-timer.C + } + return + } + case <-t.shutdownChan: + if !timer.Stop() { + <-timer.C + } + return + } + } +} + +func (t *http2Client) Error() <-chan struct{} { + return t.errorChan +} + +func (t *http2Client) GoAway() <-chan struct{} { + return t.goAway +} + +func (t *http2Client) notifyError(err error) { + t.mu.Lock() + // make sure t.errorChan is closed only once. + if t.state == draining { + t.mu.Unlock() + t.Close() + return + } + if t.state == reachable { + t.state = unreachable + close(t.errorChan) + grpclog.Printf("transport: http2Client.notifyError got notified that the client transport was broken %v.", err) + } + t.mu.Unlock() +} |