diff options
Diffstat (limited to 'vendor/golang.org/x/net/http2/transport.go')
| -rw-r--r-- | vendor/golang.org/x/net/http2/transport.go | 1424 |
1 files changed, 838 insertions, 586 deletions
diff --git a/vendor/golang.org/x/net/http2/transport.go b/vendor/golang.org/x/net/http2/transport.go index b261beb1d..6d6f88589 100644 --- a/vendor/golang.org/x/net/http2/transport.go +++ b/vendor/golang.org/x/net/http2/transport.go @@ -24,6 +24,7 @@ import ( "net/http" "net/http/httptrace" "net/textproto" + "os" "sort" "strconv" "strings" @@ -51,6 +52,15 @@ const ( transportDefaultStreamMinRefresh = 4 << 10 defaultUserAgent = "Go-http-client/2.0" + + // initialMaxConcurrentStreams is a connections maxConcurrentStreams until + // it's received servers initial SETTINGS frame, which corresponds with the + // spec's minimum recommended value. + initialMaxConcurrentStreams = 100 + + // defaultMaxConcurrentStreams is a connections default maxConcurrentStreams + // if the server doesn't include one in its initial SETTINGS frame. + defaultMaxConcurrentStreams = 1000 ) // Transport is an HTTP/2 Transport. @@ -121,6 +131,17 @@ type Transport struct { // Defaults to 15s. PingTimeout time.Duration + // WriteByteTimeout is the timeout after which the connection will be + // closed no data can be written to it. The timeout begins when data is + // available to write, and is extended whenever any bytes are written. + WriteByteTimeout time.Duration + + // CountError, if non-nil, is called on HTTP/2 transport errors. + // It's intended to increment a metric for monitoring, such + // as an expvar or Prometheus metric. + // The errType consists of only ASCII word characters. + CountError func(errType string) + // t1, if non-nil, is the standard library Transport using // this transport. Its settings are used (but not its // RoundTrip method, etc). @@ -227,11 +248,12 @@ func (t *Transport) initConnPool() { // ClientConn is the state of a single HTTP/2 client connection to an // HTTP/2 server. type ClientConn struct { - t *Transport - tconn net.Conn // usually *tls.Conn, except specialized impls - tlsState *tls.ConnectionState // nil only for specialized impls - reused uint32 // whether conn is being reused; atomic - singleUse bool // whether being used for a single http.Request + t *Transport + tconn net.Conn // usually *tls.Conn, except specialized impls + tlsState *tls.ConnectionState // nil only for specialized impls + reused uint32 // whether conn is being reused; atomic + singleUse bool // whether being used for a single http.Request + getConnCalled bool // used by clientConnPool // readLoop goroutine fields: readerDone chan struct{} // closed on error @@ -244,86 +266,94 @@ type ClientConn struct { cond *sync.Cond // hold mu; broadcast on flow/closed changes flow flow // our conn-level flow control quota (cs.flow is per stream) inflow flow // peer's conn-level flow control + doNotReuse bool // whether conn is marked to not be reused for any future requests closing bool closed bool + seenSettings bool // true if we've seen a settings frame, false otherwise wantSettingsAck bool // we sent a SETTINGS frame and haven't heard back goAway *GoAwayFrame // if non-nil, the GoAwayFrame we received goAwayDebug string // goAway frame's debug data, retained as a string streams map[uint32]*clientStream // client-initiated + streamsReserved int // incr by ReserveNewRequest; decr on RoundTrip nextStreamID uint32 pendingRequests int // requests blocked and waiting to be sent because len(streams) == maxConcurrentStreams pings map[[8]byte]chan struct{} // in flight ping data to notification channel - bw *bufio.Writer br *bufio.Reader - fr *Framer lastActive time.Time lastIdle time.Time // time last idle - // Settings from peer: (also guarded by mu) + // Settings from peer: (also guarded by wmu) maxFrameSize uint32 maxConcurrentStreams uint32 peerMaxHeaderListSize uint64 initialWindowSize uint32 + // reqHeaderMu is a 1-element semaphore channel controlling access to sending new requests. + // Write to reqHeaderMu to lock it, read from it to unlock. + // Lock reqmu BEFORE mu or wmu. + reqHeaderMu chan struct{} + + // wmu is held while writing. + // Acquire BEFORE mu when holding both, to avoid blocking mu on network writes. + // Only acquire both at the same time when changing peer settings. + wmu sync.Mutex + bw *bufio.Writer + fr *Framer + werr error // first write error that has occurred hbuf bytes.Buffer // HPACK encoder writes into this henc *hpack.Encoder - - wmu sync.Mutex // held while writing; acquire AFTER mu if holding both - werr error // first write error that has occurred } // clientStream is the state for a single HTTP/2 stream. One of these // is created for each Transport.RoundTrip call. type clientStream struct { - cc *ClientConn - req *http.Request + cc *ClientConn + + // Fields of Request that we may access even after the response body is closed. + ctx context.Context + reqCancel <-chan struct{} + trace *httptrace.ClientTrace // or nil ID uint32 - resc chan resAndError bufPipe pipe // buffered pipe with the flow-controlled response payload - startedWrite bool // started request body write; guarded by cc.mu requestedGzip bool - on100 func() // optional code to run if get a 100 continue response + isHead bool + + abortOnce sync.Once + abort chan struct{} // closed to signal stream should end immediately + abortErr error // set if abort is closed + + peerClosed chan struct{} // closed when the peer sends an END_STREAM flag + donec chan struct{} // closed after the stream is in the closed state + on100 chan struct{} // buffered; written to if a 100 is received + + respHeaderRecv chan struct{} // closed when headers are received + res *http.Response // set if respHeaderRecv is closed flow flow // guarded by cc.mu inflow flow // guarded by cc.mu bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read readErr error // sticky read error; owned by transportResponseBody.Read - stopReqBody error // if non-nil, stop writing req body; guarded by cc.mu - didReset bool // whether we sent a RST_STREAM to the server; guarded by cc.mu - peerReset chan struct{} // closed on peer reset - resetErr error // populated before peerReset is closed + reqBody io.ReadCloser + reqBodyContentLength int64 // -1 means unknown + reqBodyClosed bool // body has been closed; guarded by cc.mu - done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu + // owned by writeRequest: + sentEndStream bool // sent an END_STREAM flag to the peer + sentHeaders bool // owned by clientConnReadLoop: firstByte bool // got the first response byte pastHeaders bool // got first MetaHeadersFrame (actual headers) pastTrailers bool // got optional second MetaHeadersFrame (trailers) num1xx uint8 // number of 1xx responses seen + readClosed bool // peer sent an END_STREAM flag + readAborted bool // read loop reset the stream trailer http.Header // accumulated trailers resTrailer *http.Header // client's Response.Trailer } -// awaitRequestCancel waits for the user to cancel a request or for the done -// channel to be signaled. A non-nil error is returned only if the request was -// canceled. -func awaitRequestCancel(req *http.Request, done <-chan struct{}) error { - ctx := req.Context() - if req.Cancel == nil && ctx.Done() == nil { - return nil - } - select { - case <-req.Cancel: - return errRequestCanceled - case <-ctx.Done(): - return ctx.Err() - case <-done: - return nil - } -} - var got1xxFuncForTests func(int, textproto.MIMEHeader) error // get1xxTraceFunc returns the value of request's httptrace.ClientTrace.Got1xxResponse func, @@ -335,78 +365,65 @@ func (cs *clientStream) get1xxTraceFunc() func(int, textproto.MIMEHeader) error return traceGot1xxResponseFunc(cs.trace) } -// awaitRequestCancel waits for the user to cancel a request, its context to -// expire, or for the request to be done (any way it might be removed from the -// cc.streams map: peer reset, successful completion, TCP connection breakage, -// etc). If the request is canceled, then cs will be canceled and closed. -func (cs *clientStream) awaitRequestCancel(req *http.Request) { - if err := awaitRequestCancel(req, cs.done); err != nil { - cs.cancelStream() - cs.bufPipe.CloseWithError(err) - } +func (cs *clientStream) abortStream(err error) { + cs.cc.mu.Lock() + defer cs.cc.mu.Unlock() + cs.abortStreamLocked(err) } -func (cs *clientStream) cancelStream() { - cc := cs.cc - cc.mu.Lock() - didReset := cs.didReset - cs.didReset = true - cc.mu.Unlock() - - if !didReset { - cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) - cc.forgetStreamID(cs.ID) +func (cs *clientStream) abortStreamLocked(err error) { + cs.abortOnce.Do(func() { + cs.abortErr = err + close(cs.abort) + }) + if cs.reqBody != nil && !cs.reqBodyClosed { + cs.reqBody.Close() + cs.reqBodyClosed = true } -} - -// checkResetOrDone reports any error sent in a RST_STREAM frame by the -// server, or errStreamClosed if the stream is complete. -func (cs *clientStream) checkResetOrDone() error { - select { - case <-cs.peerReset: - return cs.resetErr - case <-cs.done: - return errStreamClosed - default: - return nil + // TODO(dneil): Clean up tests where cs.cc.cond is nil. + if cs.cc.cond != nil { + // Wake up writeRequestBody if it is waiting on flow control. + cs.cc.cond.Broadcast() } } -func (cs *clientStream) getStartedWrite() bool { +func (cs *clientStream) abortRequestBodyWrite() { cc := cs.cc cc.mu.Lock() defer cc.mu.Unlock() - return cs.startedWrite -} - -func (cs *clientStream) abortRequestBodyWrite(err error) { - if err == nil { - panic("nil error") - } - cc := cs.cc - cc.mu.Lock() - if cs.stopReqBody == nil { - cs.stopReqBody = err - if cs.req.Body != nil { - cs.req.Body.Close() - } + if cs.reqBody != nil && !cs.reqBodyClosed { + cs.reqBody.Close() + cs.reqBodyClosed = true cc.cond.Broadcast() } - cc.mu.Unlock() } type stickyErrWriter struct { - w io.Writer - err *error + conn net.Conn + timeout time.Duration + err *error } func (sew stickyErrWriter) Write(p []byte) (n int, err error) { if *sew.err != nil { return 0, *sew.err } - n, err = sew.w.Write(p) - *sew.err = err - return + for { + if sew.timeout != 0 { + sew.conn.SetWriteDeadline(time.Now().Add(sew.timeout)) + } + nn, err := sew.conn.Write(p[n:]) + n += nn + if n < len(p) && nn > 0 && errors.Is(err, os.ErrDeadlineExceeded) { + // Keep extending the deadline so long as we're making progress. + continue + } + if sew.timeout != 0 { + sew.conn.SetWriteDeadline(time.Time{}) + } + *sew.err = err + return n, err + } } // noCachedConnError is the concrete type of ErrNoCachedConn, which @@ -479,9 +496,9 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res } reused := !atomic.CompareAndSwapUint32(&cc.reused, 0, 1) traceGotConn(req, cc, reused) - res, gotErrAfterReqBodyWrite, err := cc.roundTrip(req) + res, err := cc.RoundTrip(req) if err != nil && retry <= 6 { - if req, err = shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil { + if req, err = shouldRetryRequest(req, err); err == nil { // After the first retry, do exponential backoff with 10% jitter. if retry == 0 { continue @@ -492,7 +509,7 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res case <-time.After(time.Second * time.Duration(backoff)): continue case <-req.Context().Done(): - return nil, req.Context().Err() + err = req.Context().Err() } } } @@ -523,7 +540,7 @@ var ( // response headers. It is always called with a non-nil error. // It returns either a request to retry (either the same request, or a // modified clone), or an error if the request can't be replayed. -func shouldRetryRequest(req *http.Request, err error, afterBodyWrite bool) (*http.Request, error) { +func shouldRetryRequest(req *http.Request, err error) (*http.Request, error) { if !canRetryError(err) { return nil, err } @@ -536,7 +553,6 @@ func shouldRetryRequest(req *http.Request, err error, afterBodyWrite bool) (*htt // If the request body can be reset back to its original // state via the optional req.GetBody, do that. if req.GetBody != nil { - // TODO: consider a req.Body.Close here? or audit that all caller paths do? body, err := req.GetBody() if err != nil { return nil, err @@ -548,10 +564,8 @@ func shouldRetryRequest(req *http.Request, err error, afterBodyWrite bool) (*htt // The Request.Body can't reset back to the beginning, but we // don't seem to have started to read from it yet, so reuse - // the request directly. The "afterBodyWrite" means the - // bodyWrite process has started, which becomes true before - // the first Read. - if !afterBodyWrite { + // the request directly. + if err == errClientConnUnusable { return req, nil } @@ -563,6 +577,10 @@ func canRetryError(err error) bool { return true } if se, ok := err.(StreamError); ok { + if se.Code == ErrCodeProtocol && se.Cause == errFromPeer { + // See golang/go#47635, golang/go#42777 + return true + } return se.Code == ErrCodeRefusedStream } return false @@ -637,14 +655,15 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro tconn: c, readerDone: make(chan struct{}), nextStreamID: 1, - maxFrameSize: 16 << 10, // spec default - initialWindowSize: 65535, // spec default - maxConcurrentStreams: 1000, // "infinite", per spec. 1000 seems good enough. - peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead. + maxFrameSize: 16 << 10, // spec default + initialWindowSize: 65535, // spec default + maxConcurrentStreams: initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings. + peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead. streams: make(map[uint32]*clientStream), singleUse: singleUse, wantSettingsAck: true, pings: make(map[[8]byte]chan struct{}), + reqHeaderMu: make(chan struct{}, 1), } if d := t.idleConnTimeout(); d != 0 { cc.idleTimeout = d @@ -659,9 +678,16 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro // TODO: adjust this writer size to account for frame size + // MTU + crypto/tls record padding. - cc.bw = bufio.NewWriter(stickyErrWriter{c, &cc.werr}) + cc.bw = bufio.NewWriter(stickyErrWriter{ + conn: c, + timeout: t.WriteByteTimeout, + err: &cc.werr, + }) cc.br = bufio.NewReader(c) cc.fr = NewFramer(cc.bw, cc.br) + if t.CountError != nil { + cc.fr.countError = t.CountError + } cc.fr.ReadMetaHeaders = hpack.NewDecoder(initialHeaderTableSize, nil) cc.fr.MaxHeaderListSize = t.maxHeaderListSize() @@ -714,6 +740,13 @@ func (cc *ClientConn) healthCheck() { } } +// SetDoNotReuse marks cc as not reusable for future HTTP requests. +func (cc *ClientConn) SetDoNotReuse() { + cc.mu.Lock() + defer cc.mu.Unlock() + cc.doNotReuse = true +} + func (cc *ClientConn) setGoAway(f *GoAwayFrame) { cc.mu.Lock() defer cc.mu.Unlock() @@ -731,27 +764,94 @@ func (cc *ClientConn) setGoAway(f *GoAwayFrame) { last := f.LastStreamID for streamID, cs := range cc.streams { if streamID > last { - select { - case cs.resc <- resAndError{err: errClientConnGotGoAway}: - default: - } + cs.abortStreamLocked(errClientConnGotGoAway) } } } // CanTakeNewRequest reports whether the connection can take a new request, // meaning it has not been closed or received or sent a GOAWAY. +// +// If the caller is going to immediately make a new request on this +// connection, use ReserveNewRequest instead. func (cc *ClientConn) CanTakeNewRequest() bool { cc.mu.Lock() defer cc.mu.Unlock() return cc.canTakeNewRequestLocked() } +// ReserveNewRequest is like CanTakeNewRequest but also reserves a +// concurrent stream in cc. The reservation is decremented on the +// next call to RoundTrip. +func (cc *ClientConn) ReserveNewRequest() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + if st := cc.idleStateLocked(); !st.canTakeNewRequest { + return false + } + cc.streamsReserved++ + return true +} + +// ClientConnState describes the state of a ClientConn. +type ClientConnState struct { + // Closed is whether the connection is closed. + Closed bool + + // Closing is whether the connection is in the process of + // closing. It may be closing due to shutdown, being a + // single-use connection, being marked as DoNotReuse, or + // having received a GOAWAY frame. + Closing bool + + // StreamsActive is how many streams are active. + StreamsActive int + + // StreamsReserved is how many streams have been reserved via + // ClientConn.ReserveNewRequest. + StreamsReserved int + + // StreamsPending is how many requests have been sent in excess + // of the peer's advertised MaxConcurrentStreams setting and + // are waiting for other streams to complete. + StreamsPending int + + // MaxConcurrentStreams is how many concurrent streams the + // peer advertised as acceptable. Zero means no SETTINGS + // frame has been received yet. + MaxConcurrentStreams uint32 + + // LastIdle, if non-zero, is when the connection last + // transitioned to idle state. + LastIdle time.Time +} + +// State returns a snapshot of cc's state. +func (cc *ClientConn) State() ClientConnState { + cc.wmu.Lock() + maxConcurrent := cc.maxConcurrentStreams + if !cc.seenSettings { + maxConcurrent = 0 + } + cc.wmu.Unlock() + + cc.mu.Lock() + defer cc.mu.Unlock() + return ClientConnState{ + Closed: cc.closed, + Closing: cc.closing || cc.singleUse || cc.doNotReuse || cc.goAway != nil, + StreamsActive: len(cc.streams), + StreamsReserved: cc.streamsReserved, + StreamsPending: cc.pendingRequests, + LastIdle: cc.lastIdle, + MaxConcurrentStreams: maxConcurrent, + } +} + // clientConnIdleState describes the suitability of a client // connection to initiate a new RoundTrip request. type clientConnIdleState struct { canTakeNewRequest bool - freshConn bool // whether it's unused by any previous request } func (cc *ClientConn) idleState() clientConnIdleState { @@ -772,13 +872,13 @@ func (cc *ClientConn) idleStateLocked() (st clientConnIdleState) { // writing it. maxConcurrentOkay = true } else { - maxConcurrentOkay = int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams) + maxConcurrentOkay = int64(len(cc.streams)+cc.streamsReserved+1) <= int64(cc.maxConcurrentStreams) } st.canTakeNewRequest = cc.goAway == nil && !cc.closed && !cc.closing && maxConcurrentOkay && + !cc.doNotReuse && int64(cc.nextStreamID)+2*int64(cc.pendingRequests) < math.MaxInt32 && !cc.tooIdleLocked() - st.freshConn = cc.nextStreamID == 1 && st.canTakeNewRequest return } @@ -809,7 +909,7 @@ func (cc *ClientConn) onIdleTimeout() { func (cc *ClientConn) closeIfIdle() { cc.mu.Lock() - if len(cc.streams) > 0 { + if len(cc.streams) > 0 || cc.streamsReserved > 0 { cc.mu.Unlock() return } @@ -824,9 +924,15 @@ func (cc *ClientConn) closeIfIdle() { cc.tconn.Close() } +func (cc *ClientConn) isDoNotReuseAndIdle() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.doNotReuse && len(cc.streams) == 0 +} + var shutdownEnterWaitStateHook = func() {} -// Shutdown gracefully close the client connection, waiting for running streams to complete. +// Shutdown gracefully closes the client connection, waiting for running streams to complete. func (cc *ClientConn) Shutdown(ctx context.Context) error { if err := cc.sendGoAway(); err != nil { return err @@ -865,15 +971,18 @@ func (cc *ClientConn) Shutdown(ctx context.Context) error { func (cc *ClientConn) sendGoAway() error { cc.mu.Lock() - defer cc.mu.Unlock() - cc.wmu.Lock() - defer cc.wmu.Unlock() - if cc.closing { + closing := cc.closing + cc.closing = true + maxStreamID := cc.nextStreamID + cc.mu.Unlock() + if closing { // GOAWAY sent already return nil } + + cc.wmu.Lock() + defer cc.wmu.Unlock() // Send a graceful shutdown frame to server - maxStreamID := cc.nextStreamID if err := cc.fr.WriteGoAway(maxStreamID, ErrCodeNo, nil); err != nil { return err } @@ -881,7 +990,6 @@ func (cc *ClientConn) sendGoAway() error { return err } // Prevent new requests - cc.closing = true return nil } @@ -889,17 +997,12 @@ func (cc *ClientConn) sendGoAway() error { // err is sent to streams. func (cc *ClientConn) closeForError(err error) error { cc.mu.Lock() + cc.closed = true + for _, cs := range cc.streams { + cs.abortStreamLocked(err) + } defer cc.cond.Broadcast() defer cc.mu.Unlock() - for id, cs := range cc.streams { - select { - case cs.resc <- resAndError{err: err}: - default: - } - cs.bufPipe.CloseWithError(err) - delete(cc.streams, id) - } - cc.closed = true return cc.tconn.Close() } @@ -914,6 +1017,9 @@ func (cc *ClientConn) Close() error { // closes the client connection immediately. In-flight requests are interrupted. func (cc *ClientConn) closeForLostPing() error { err := errors.New("http2: client connection lost") + if f := cc.t.CountError; f != nil { + f("conn_close_lost_ping") + } return cc.closeForError(err) } @@ -978,41 +1084,142 @@ func actualContentLength(req *http.Request) int64 { return -1 } +func (cc *ClientConn) decrStreamReservations() { + cc.mu.Lock() + defer cc.mu.Unlock() + cc.decrStreamReservationsLocked() +} + +func (cc *ClientConn) decrStreamReservationsLocked() { + if cc.streamsReserved > 0 { + cc.streamsReserved-- + } +} + func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) { - resp, _, err := cc.roundTrip(req) - return resp, err + ctx := req.Context() + cs := &clientStream{ + cc: cc, + ctx: ctx, + reqCancel: req.Cancel, + isHead: req.Method == "HEAD", + reqBody: req.Body, + reqBodyContentLength: actualContentLength(req), + trace: httptrace.ContextClientTrace(ctx), + peerClosed: make(chan struct{}), + abort: make(chan struct{}), + respHeaderRecv: make(chan struct{}), + donec: make(chan struct{}), + } + go cs.doRequest(req) + + waitDone := func() error { + select { + case <-cs.donec: + return nil + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return errRequestCanceled + } + } + + for { + select { + case <-cs.respHeaderRecv: + res := cs.res + if res.StatusCode > 299 { + // On error or status code 3xx, 4xx, 5xx, etc abort any + // ongoing write, assuming that the server doesn't care + // about our request body. If the server replied with 1xx or + // 2xx, however, then assume the server DOES potentially + // want our body (e.g. full-duplex streaming: + // golang.org/issue/13444). If it turns out the server + // doesn't, they'll RST_STREAM us soon enough. This is a + // heuristic to avoid adding knobs to Transport. Hopefully + // we can keep it. + cs.abortRequestBodyWrite() + } + res.Request = req + res.TLS = cc.tlsState + if res.Body == noBody && actualContentLength(req) == 0 { + // If there isn't a request or response body still being + // written, then wait for the stream to be closed before + // RoundTrip returns. + if err := waitDone(); err != nil { + return nil, err + } + } + return res, nil + case <-cs.abort: + waitDone() + return nil, cs.abortErr + case <-ctx.Done(): + err := ctx.Err() + cs.abortStream(err) + return nil, err + case <-cs.reqCancel: + cs.abortStream(errRequestCanceled) + return nil, errRequestCanceled + } + } +} + +// doRequest runs for the duration of the request lifetime. +// +// It sends the request and performs post-request cleanup (closing Request.Body, etc.). +func (cs *clientStream) doRequest(req *http.Request) { + err := cs.writeRequest(req) + cs.cleanupWriteRequest(err) } -func (cc *ClientConn) roundTrip(req *http.Request) (res *http.Response, gotErrAfterReqBodyWrite bool, err error) { +// writeRequest sends a request. +// +// It returns nil after the request is written, the response read, +// and the request stream is half-closed by the peer. +// +// It returns non-nil if the request ends otherwise. +// If the returned error is StreamError, the error Code may be used in resetting the stream. +func (cs *clientStream) writeRequest(req *http.Request) (err error) { + cc := cs.cc + ctx := cs.ctx + if err := checkConnHeaders(req); err != nil { - return nil, false, err - } - if cc.idleTimer != nil { - cc.idleTimer.Stop() + return err } - trailers, err := commaSeparatedTrailers(req) - if err != nil { - return nil, false, err + // Acquire the new-request lock by writing to reqHeaderMu. + // This lock guards the critical section covering allocating a new stream ID + // (requires mu) and creating the stream (requires wmu). + if cc.reqHeaderMu == nil { + panic("RoundTrip on uninitialized ClientConn") // for tests + } + select { + case cc.reqHeaderMu <- struct{}{}: + case <-cs.reqCancel: + return errRequestCanceled + case <-ctx.Done(): + return ctx.Err() } - hasTrailers := trailers != "" cc.mu.Lock() - if err := cc.awaitOpenSlotForRequest(req); err != nil { + if cc.idleTimer != nil { + cc.idleTimer.Stop() + } + cc.decrStreamReservationsLocked() + if err := cc.awaitOpenSlotForStreamLocked(cs); err != nil { cc.mu.Unlock() - return nil, false, err + <-cc.reqHeaderMu + return err } - - body := req.Body - contentLen := actualContentLength(req) - hasBody := contentLen != 0 + cc.addStreamLocked(cs) // assigns stream ID + cc.mu.Unlock() // TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere? - var requestedGzip bool if !cc.t.disableCompression() && req.Header.Get("Accept-Encoding") == "" && req.Header.Get("Range") == "" && - req.Method != "HEAD" { + !cs.isHead { // Request gzip only, not deflate. Deflate is ambiguous and // not as universally supported anyway. // See: https://zlib.net/zlib_faq.html#faq39 @@ -1025,183 +1232,223 @@ func (cc *ClientConn) roundTrip(req *http.Request) (res *http.Response, gotErrAf // We don't request gzip if the request is for a range, since // auto-decoding a portion of a gzipped document will just fail // anyway. See https://golang.org/issue/8923 - requestedGzip = true + cs.requestedGzip = true } - // we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is - // sent by writeRequestBody below, along with any Trailers, - // again in form HEADERS{1}, CONTINUATION{0,}) - hdrs, err := cc.encodeHeaders(req, requestedGzip, trailers, contentLen) + continueTimeout := cc.t.expectContinueTimeout() + if continueTimeout != 0 && + !httpguts.HeaderValuesContainsToken( + req.Header["Expect"], + "100-continue") { + continueTimeout = 0 + cs.on100 = make(chan struct{}, 1) + } + + // Past this point (where we send request headers), it is possible for + // RoundTrip to return successfully. Since the RoundTrip contract permits + // the caller to "mutate or reuse" the Request after closing the Response's Body, + // we must take care when referencing the Request from here on. + err = cs.encodeAndWriteHeaders(req) + <-cc.reqHeaderMu if err != nil { - cc.mu.Unlock() - return nil, false, err + return err } - cs := cc.newStream() - cs.req = req - cs.trace = httptrace.ContextClientTrace(req.Context()) - cs.requestedGzip = requestedGzip - bodyWriter := cc.t.getBodyWriterState(cs, body) - cs.on100 = bodyWriter.on100 + hasBody := cs.reqBodyContentLength != 0 + if !hasBody { + cs.sentEndStream = true + } else { + if continueTimeout != 0 { + traceWait100Continue(cs.trace) + timer := time.NewTimer(continueTimeout) + select { + case <-timer.C: + err = nil + case <-cs.on100: + err = nil + case <-cs.abort: + err = cs.abortErr + case <-ctx.Done(): + err = ctx.Err() + case <-cs.reqCancel: + err = errRequestCanceled + } + timer.Stop() + if err != nil { + traceWroteRequest(cs.trace, err) + return err + } + } - defer func() { - cc.wmu.Lock() - werr := cc.werr - cc.wmu.Unlock() - if werr != nil { - cc.Close() + if err = cs.writeRequestBody(req); err != nil { + if err != errStopReqBodyWrite { + traceWroteRequest(cs.trace, err) + return err + } + } else { + cs.sentEndStream = true } - }() + } + + traceWroteRequest(cs.trace, err) + + var respHeaderTimer <-chan time.Time + var respHeaderRecv chan struct{} + if d := cc.responseHeaderTimeout(); d != 0 { + timer := time.NewTimer(d) + defer timer.Stop() + respHeaderTimer = timer.C + respHeaderRecv = cs.respHeaderRecv + } + // Wait until the peer half-closes its end of the stream, + // or until the request is aborted (via context, error, or otherwise), + // whichever comes first. + for { + select { + case <-cs.peerClosed: + return nil + case <-respHeaderTimer: + return errTimeout + case <-respHeaderRecv: + respHeaderTimer = nil // keep waiting for END_STREAM + case <-cs.abort: + return cs.abortErr + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return errRequestCanceled + } + } +} + +func (cs *clientStream) encodeAndWriteHeaders(req *http.Request) error { + cc := cs.cc + ctx := cs.ctx cc.wmu.Lock() + defer cc.wmu.Unlock() + + // If the request was canceled while waiting for cc.mu, just quit. + select { + case <-cs.abort: + return cs.abortErr + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return errRequestCanceled + default: + } + + // Encode headers. + // + // we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is + // sent by writeRequestBody below, along with any Trailers, + // again in form HEADERS{1}, CONTINUATION{0,}) + trailers, err := commaSeparatedTrailers(req) + if err != nil { + return err + } + hasTrailers := trailers != "" + contentLen := actualContentLength(req) + hasBody := contentLen != 0 + hdrs, err := cc.encodeHeaders(req, cs.requestedGzip, trailers, contentLen) + if err != nil { + return err + } + + // Write the request. endStream := !hasBody && !hasTrailers - werr := cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs) - cc.wmu.Unlock() + cs.sentHeaders = true + err = cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs) traceWroteHeaders(cs.trace) - cc.mu.Unlock() + return err +} - if werr != nil { - if hasBody { - req.Body.Close() // per RoundTripper contract - bodyWriter.cancel() - } - cc.forgetStreamID(cs.ID) - // Don't bother sending a RST_STREAM (our write already failed; - // no need to keep writing) - traceWroteRequest(cs.trace, werr) - return nil, false, werr - } +// cleanupWriteRequest performs post-request tasks. +// +// If err (the result of writeRequest) is non-nil and the stream is not closed, +// cleanupWriteRequest will send a reset to the peer. +func (cs *clientStream) cleanupWriteRequest(err error) { + cc := cs.cc - var respHeaderTimer <-chan time.Time - if hasBody { - bodyWriter.scheduleBodyWrite() - } else { - traceWroteRequest(cs.trace, nil) - if d := cc.responseHeaderTimeout(); d != 0 { - timer := time.NewTimer(d) - defer timer.Stop() - respHeaderTimer = timer.C - } + if cs.ID == 0 { + // We were canceled before creating the stream, so return our reservation. + cc.decrStreamReservations() } - readLoopResCh := cs.resc - bodyWritten := false - ctx := req.Context() + // TODO: write h12Compare test showing whether + // Request.Body is closed by the Transport, + // and in multiple cases: server replies <=299 and >299 + // while still writing request body + cc.mu.Lock() + bodyClosed := cs.reqBodyClosed + cs.reqBodyClosed = true + cc.mu.Unlock() + if !bodyClosed && cs.reqBody != nil { + cs.reqBody.Close() + } - handleReadLoopResponse := func(re resAndError) (*http.Response, bool, error) { - res := re.res - if re.err != nil || res.StatusCode > 299 { - // On error or status code 3xx, 4xx, 5xx, etc abort any - // ongoing write, assuming that the server doesn't care - // about our request body. If the server replied with 1xx or - // 2xx, however, then assume the server DOES potentially - // want our body (e.g. full-duplex streaming: - // golang.org/issue/13444). If it turns out the server - // doesn't, they'll RST_STREAM us soon enough. This is a - // heuristic to avoid adding knobs to Transport. Hopefully - // we can keep it. - bodyWriter.cancel() - cs.abortRequestBodyWrite(errStopReqBodyWrite) - if hasBody && !bodyWritten { - <-bodyWriter.resc + if err != nil && cs.sentEndStream { + // If the connection is closed immediately after the response is read, + // we may be aborted before finishing up here. If the stream was closed + // cleanly on both sides, there is no error. + select { + case <-cs.peerClosed: + err = nil + default: + } + } + if err != nil { + cs.abortStream(err) // possibly redundant, but harmless + if cs.sentHeaders { + if se, ok := err.(StreamError); ok { + if se.Cause != errFromPeer { + cc.writeStreamReset(cs.ID, se.Code, err) + } + } else { + cc.writeStreamReset(cs.ID, ErrCodeCancel, err) } } - if re.err != nil { - cc.forgetStreamID(cs.ID) - return nil, cs.getStartedWrite(), re.err + cs.bufPipe.CloseWithError(err) // no-op if already closed + } else { + if cs.sentHeaders && !cs.sentEndStream { + cc.writeStreamReset(cs.ID, ErrCodeNo, nil) } - res.Request = req - res.TLS = cc.tlsState - return res, false, nil + cs.bufPipe.CloseWithError(errRequestCanceled) } - - handleError := func(err error) (*http.Response, bool, error) { - if !hasBody || bodyWritten { - cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) - } else { - bodyWriter.cancel() - cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel) - <-bodyWriter.resc - } + if cs.ID != 0 { cc.forgetStreamID(cs.ID) - return nil, cs.getStartedWrite(), err } - for { - select { - case re := <-readLoopResCh: - return handleReadLoopResponse(re) - case <-respHeaderTimer: - return handleError(errTimeout) - case <-ctx.Done(): - return handleError(ctx.Err()) - case <-req.Cancel: - return handleError(errRequestCanceled) - case <-cs.peerReset: - // processResetStream already removed the - // stream from the streams map; no need for - // forgetStreamID. - return nil, cs.getStartedWrite(), cs.resetErr - case err := <-bodyWriter.resc: - bodyWritten = true - // Prefer the read loop's response, if available. Issue 16102. - select { - case re := <-readLoopResCh: - return handleReadLoopResponse(re) - default: - } - if err != nil { - cc.forgetStreamID(cs.ID) - return nil, cs.getStartedWrite(), err - } - if d := cc.responseHeaderTimeout(); d != 0 { - timer := time.NewTimer(d) - defer timer.Stop() - respHeaderTimer = timer.C - } - } + cc.wmu.Lock() + werr := cc.werr + cc.wmu.Unlock() + if werr != nil { + cc.Close() } + + close(cs.donec) } -// awaitOpenSlotForRequest waits until len(streams) < maxConcurrentStreams. +// awaitOpenSlotForStream waits until len(streams) < maxConcurrentStreams. // Must hold cc.mu. -func (cc *ClientConn) awaitOpenSlotForRequest(req *http.Request) error { - var waitingForConn chan struct{} - var waitingForConnErr error // guarded by cc.mu +func (cc *ClientConn) awaitOpenSlotForStreamLocked(cs *clientStream) error { for { cc.lastActive = time.Now() if cc.closed || !cc.canTakeNewRequestLocked() { - if waitingForConn != nil { - close(waitingForConn) - } return errClientConnUnusable } cc.lastIdle = time.Time{} - if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) { - if waitingForConn != nil { - close(waitingForConn) - } + if int64(len(cc.streams)) < int64(cc.maxConcurrentStreams) { return nil } - // Unfortunately, we cannot wait on a condition variable and channel at - // the same time, so instead, we spin up a goroutine to check if the - // request is canceled while we wait for a slot to open in the connection. - if waitingForConn == nil { - waitingForConn = make(chan struct{}) - go func() { - if err := awaitRequestCancel(req, waitingForConn); err != nil { - cc.mu.Lock() - waitingForConnErr = err - cc.cond.Broadcast() - cc.mu.Unlock() - } - }() - } cc.pendingRequests++ cc.cond.Wait() cc.pendingRequests-- - if waitingForConnErr != nil { - return waitingForConnErr + select { + case <-cs.abort: + return cs.abortErr + default: } } } @@ -1228,10 +1475,6 @@ func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, maxFrameSize cc.fr.WriteContinuation(streamID, endHeaders, chunk) } } - // TODO(bradfitz): this Flush could potentially block (as - // could the WriteHeaders call(s) above), which means they - // wouldn't respond to Request.Cancel being readable. That's - // rare, but this should probably be in a goroutine. cc.bw.Flush() return cc.werr } @@ -1258,7 +1501,7 @@ func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int { if n > max { n = max } - if cl := actualContentLength(cs.req); cl != -1 && cl+1 < n { + if cl := cs.reqBodyContentLength; cl != -1 && cl+1 < n { // Add an extra byte past the declared content-length to // give the caller's Request.Body io.Reader a chance to // give us more bytes than they declared, so we can catch it @@ -1273,31 +1516,13 @@ func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int { var bufPool sync.Pool // of *[]byte -func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) { +func (cs *clientStream) writeRequestBody(req *http.Request) (err error) { cc := cs.cc + body := cs.reqBody sentEnd := false // whether we sent the final DATA frame w/ END_STREAM - defer func() { - traceWroteRequest(cs.trace, err) - // TODO: write h12Compare test showing whether - // Request.Body is closed by the Transport, - // and in multiple cases: server replies <=299 and >299 - // while still writing request body - var cerr error - cc.mu.Lock() - if cs.stopReqBody == nil { - cs.stopReqBody = errStopReqBodyWrite - cerr = bodyCloser.Close() - } - cc.mu.Unlock() - if err == nil { - err = cerr - } - }() - - req := cs.req hasTrailers := req.Trailer != nil - remainLen := actualContentLength(req) + remainLen := cs.reqBodyContentLength hasContentLen := remainLen != -1 cc.mu.Lock() @@ -1335,29 +1560,29 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) ( } if remainLen < 0 { err = errReqBodyTooLong - cc.writeStreamReset(cs.ID, ErrCodeCancel, err) return err } } - if err == io.EOF { - sawEOF = true - err = nil - } else if err != nil { - cc.writeStreamReset(cs.ID, ErrCodeCancel, err) - return err + if err != nil { + cc.mu.Lock() + bodyClosed := cs.reqBodyClosed + cc.mu.Unlock() + switch { + case bodyClosed: + return errStopReqBodyWrite + case err == io.EOF: + sawEOF = true + err = nil + default: + return err + } } remain := buf[:n] for len(remain) > 0 && err == nil { var allowed int32 allowed, err = cs.awaitFlowControl(len(remain)) - switch { - case err == errStopReqBodyWrite: - return err - case err == errStopReqBodyWriteAndCancel: - cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) - return err - case err != nil: + if err != nil { return err } cc.wmu.Lock() @@ -1388,21 +1613,27 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) ( return nil } + // Since the RoundTrip contract permits the caller to "mutate or reuse" + // a request after the Response's Body is closed, verify that this hasn't + // happened before accessing the trailers. + cc.mu.Lock() + trailer := req.Trailer + err = cs.abortErr + cc.mu.Unlock() + if err != nil { + return err + } + + cc.wmu.Lock() + defer cc.wmu.Unlock() var trls []byte - if hasTrailers { - cc.mu.Lock() - trls, err = cc.encodeTrailers(req) - cc.mu.Unlock() + if len(trailer) > 0 { + trls, err = cc.encodeTrailers(trailer) if err != nil { - cc.writeStreamReset(cs.ID, ErrCodeInternal, err) - cc.forgetStreamID(cs.ID) return err } } - cc.wmu.Lock() - defer cc.wmu.Unlock() - // Two ways to send END_STREAM: either with trailers, or // with an empty DATA frame. if len(trls) > 0 { @@ -1422,17 +1653,24 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) ( // if the stream is dead. func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) { cc := cs.cc + ctx := cs.ctx cc.mu.Lock() defer cc.mu.Unlock() for { if cc.closed { return 0, errClientConnClosed } - if cs.stopReqBody != nil { - return 0, cs.stopReqBody + if cs.reqBodyClosed { + return 0, errStopReqBodyWrite } - if err := cs.checkResetOrDone(); err != nil { - return 0, err + select { + case <-cs.abort: + return 0, cs.abortErr + case <-ctx.Done(): + return 0, ctx.Err() + case <-cs.reqCancel: + return 0, errRequestCanceled + default: } if a := cs.flow.available(); a > 0 { take := a @@ -1450,9 +1688,14 @@ func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) } } -// requires cc.mu be held. +var errNilRequestURL = errors.New("http2: Request.URI is nil") + +// requires cc.wmu be held. func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) { cc.hbuf.Reset() + if req.URL == nil { + return nil, errNilRequestURL + } host := req.Host if host == "" { @@ -1638,12 +1881,12 @@ func shouldSendReqContentLength(method string, contentLength int64) bool { } } -// requires cc.mu be held. -func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) { +// requires cc.wmu be held. +func (cc *ClientConn) encodeTrailers(trailer http.Header) ([]byte, error) { cc.hbuf.Reset() hlSize := uint64(0) - for k, vv := range req.Trailer { + for k, vv := range trailer { for _, v := range vv { hf := hpack.HeaderField{Name: k, Value: v} hlSize += uint64(hf.Size()) @@ -1653,7 +1896,7 @@ func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) { return nil, errRequestHeaderListSize } - for k, vv := range req.Trailer { + for k, vv := range trailer { lowKey, ascii := asciiToLower(k) if !ascii { // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header @@ -1683,51 +1926,51 @@ type resAndError struct { } // requires cc.mu be held. -func (cc *ClientConn) newStream() *clientStream { - cs := &clientStream{ - cc: cc, - ID: cc.nextStreamID, - resc: make(chan resAndError, 1), - peerReset: make(chan struct{}), - done: make(chan struct{}), - } +func (cc *ClientConn) addStreamLocked(cs *clientStream) { cs.flow.add(int32(cc.initialWindowSize)) cs.flow.setConnFlow(&cc.flow) cs.inflow.add(transportDefaultStreamFlow) cs.inflow.setConnFlow(&cc.inflow) + cs.ID = cc.nextStreamID cc.nextStreamID += 2 cc.streams[cs.ID] = cs - return cs + if cs.ID == 0 { + panic("assigned stream ID 0") + } } func (cc *ClientConn) forgetStreamID(id uint32) { - cc.streamByID(id, true) -} - -func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream { cc.mu.Lock() - defer cc.mu.Unlock() - cs := cc.streams[id] - if andRemove && cs != nil && !cc.closed { - cc.lastActive = time.Now() - delete(cc.streams, id) - if len(cc.streams) == 0 && cc.idleTimer != nil { - cc.idleTimer.Reset(cc.idleTimeout) - cc.lastIdle = time.Now() - } - close(cs.done) - // Wake up checkResetOrDone via clientStream.awaitFlowControl and - // wake up RoundTrip if there is a pending request. - cc.cond.Broadcast() + slen := len(cc.streams) + delete(cc.streams, id) + if len(cc.streams) != slen-1 { + panic("forgetting unknown stream id") + } + cc.lastActive = time.Now() + if len(cc.streams) == 0 && cc.idleTimer != nil { + cc.idleTimer.Reset(cc.idleTimeout) + cc.lastIdle = time.Now() + } + // Wake up writeRequestBody via clientStream.awaitFlowControl and + // wake up RoundTrip if there is a pending request. + cc.cond.Broadcast() + + closeOnIdle := cc.singleUse || cc.doNotReuse || cc.t.disableKeepAlives() + if closeOnIdle && cc.streamsReserved == 0 && len(cc.streams) == 0 { + if VerboseLogs { + cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, cc.nextStreamID-2) + } + cc.closed = true + defer cc.tconn.Close() } - return cs + + cc.mu.Unlock() } // clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop. type clientConnReadLoop struct { - _ incomparable - cc *ClientConn - closeWhenIdle bool + _ incomparable + cc *ClientConn } // readLoop runs in its own goroutine and reads and dispatches frames. @@ -1787,23 +2030,49 @@ func (rl *clientConnReadLoop) cleanup() { } else if err == io.EOF { err = io.ErrUnexpectedEOF } + cc.closed = true for _, cs := range cc.streams { - cs.bufPipe.CloseWithError(err) // no-op if already closed select { - case cs.resc <- resAndError{err: err}: + case <-cs.peerClosed: + // The server closed the stream before closing the conn, + // so no need to interrupt it. default: + cs.abortStreamLocked(err) } - close(cs.done) } - cc.closed = true cc.cond.Broadcast() cc.mu.Unlock() } +// countReadFrameError calls Transport.CountError with a string +// representing err. +func (cc *ClientConn) countReadFrameError(err error) { + f := cc.t.CountError + if f == nil || err == nil { + return + } + if ce, ok := err.(ConnectionError); ok { + errCode := ErrCode(ce) + f(fmt.Sprintf("read_frame_conn_error_%s", errCode.stringToken())) + return + } + if errors.Is(err, io.EOF) { + f("read_frame_eof") + return + } + if errors.Is(err, io.ErrUnexpectedEOF) { + f("read_frame_unexpected_eof") + return + } + if errors.Is(err, ErrFrameTooLarge) { + f("read_frame_too_large") + return + } + f("read_frame_other") +} + func (rl *clientConnReadLoop) run() error { cc := rl.cc - rl.closeWhenIdle = cc.t.disableKeepAlives() || cc.singleUse - gotReply := false // ever saw a HEADERS reply gotSettings := false readIdleTimeout := cc.t.ReadIdleTimeout var t *time.Timer @@ -1820,9 +2089,7 @@ func (rl *clientConnReadLoop) run() error { cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err) } if se, ok := err.(StreamError); ok { - if cs := cc.streamByID(se.StreamID, false); cs != nil { - cs.cc.writeStreamReset(cs.ID, se.Code, err) - cs.cc.forgetStreamID(cs.ID) + if cs := rl.streamByID(se.StreamID); cs != nil { if se.Cause == nil { se.Cause = cc.fr.errDetail } @@ -1830,6 +2097,7 @@ func (rl *clientConnReadLoop) run() error { } continue } else if err != nil { + cc.countReadFrameError(err) return err } if VerboseLogs { @@ -1842,22 +2110,16 @@ func (rl *clientConnReadLoop) run() error { } gotSettings = true } - maybeIdle := false // whether frame might transition us to idle switch f := f.(type) { case *MetaHeadersFrame: err = rl.processHeaders(f) - maybeIdle = true - gotReply = true case *DataFrame: err = rl.processData(f) - maybeIdle = true case *GoAwayFrame: err = rl.processGoAway(f) - maybeIdle = true case *RSTStreamFrame: err = rl.processResetStream(f) - maybeIdle = true case *SettingsFrame: err = rl.processSettings(f) case *PushPromiseFrame: @@ -1875,38 +2137,24 @@ func (rl *clientConnReadLoop) run() error { } return err } - if rl.closeWhenIdle && gotReply && maybeIdle { - cc.closeIfIdle() - } } } func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error { - cc := rl.cc - cs := cc.streamByID(f.StreamID, false) + cs := rl.streamByID(f.StreamID) if cs == nil { // We'd get here if we canceled a request while the // server had its response still in flight. So if this // was just something we canceled, ignore it. return nil } - if f.StreamEnded() { - // Issue 20521: If the stream has ended, streamByID() causes - // clientStream.done to be closed, which causes the request's bodyWriter - // to be closed with an errStreamClosed, which may be received by - // clientConn.RoundTrip before the result of processing these headers. - // Deferring stream closure allows the header processing to occur first. - // clientConn.RoundTrip may still receive the bodyWriter error first, but - // the fix for issue 16102 prioritises any response. - // - // Issue 22413: If there is no request body, we should close the - // stream before writing to cs.resc so that the stream is closed - // immediately once RoundTrip returns. - if cs.req.Body != nil { - defer cc.forgetStreamID(f.StreamID) - } else { - cc.forgetStreamID(f.StreamID) - } + if cs.readClosed { + rl.endStreamError(cs, StreamError{ + StreamID: f.StreamID, + Code: ErrCodeProtocol, + Cause: errors.New("protocol error: headers after END_STREAM"), + }) + return nil } if !cs.firstByte { if cs.trace != nil { @@ -1930,9 +2178,11 @@ func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error { return err } // Any other error type is a stream error. - cs.cc.writeStreamReset(f.StreamID, ErrCodeProtocol, err) - cc.forgetStreamID(cs.ID) - cs.resc <- resAndError{err: err} + rl.endStreamError(cs, StreamError{ + StreamID: f.StreamID, + Code: ErrCodeProtocol, + Cause: err, + }) return nil // return nil from process* funcs to keep conn alive } if res == nil { @@ -1940,7 +2190,11 @@ func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error { return nil } cs.resTrailer = &res.Trailer - cs.resc <- resAndError{res: res} + cs.res = res + close(cs.respHeaderRecv) + if f.StreamEnded() { + rl.endStream(cs) + } return nil } @@ -2002,6 +2256,9 @@ func (rl *clientConnReadLoop) handleResponse(cs *clientStream, f *MetaHeadersFra } if statusCode >= 100 && statusCode <= 199 { + if f.StreamEnded() { + return nil, errors.New("1xx informational response with END_STREAM flag") + } cs.num1xx++ const max1xxResponses = 5 // arbitrary bound on number of informational responses, same as net/http if cs.num1xx > max1xxResponses { @@ -2014,40 +2271,47 @@ func (rl *clientConnReadLoop) handleResponse(cs *clientStream, f *MetaHeadersFra } if statusCode == 100 { traceGot100Continue(cs.trace) - if cs.on100 != nil { - cs.on100() // forces any write delay timer to fire + select { + case cs.on100 <- struct{}{}: + default: } } cs.pastHeaders = false // do it all again return nil, nil } - streamEnded := f.StreamEnded() - isHead := cs.req.Method == "HEAD" - if !streamEnded || isHead { - res.ContentLength = -1 - if clens := res.Header["Content-Length"]; len(clens) == 1 { - if cl, err := strconv.ParseUint(clens[0], 10, 63); err == nil { - res.ContentLength = int64(cl) - } else { - // TODO: care? unlike http/1, it won't mess up our framing, so it's - // more safe smuggling-wise to ignore. - } - } else if len(clens) > 1 { + res.ContentLength = -1 + if clens := res.Header["Content-Length"]; len(clens) == 1 { + if cl, err := strconv.ParseUint(clens[0], 10, 63); err == nil { + res.ContentLength = int64(cl) + } else { // TODO: care? unlike http/1, it won't mess up our framing, so it's // more safe smuggling-wise to ignore. } + } else if len(clens) > 1 { + // TODO: care? unlike http/1, it won't mess up our framing, so it's + // more safe smuggling-wise to ignore. + } else if f.StreamEnded() && !cs.isHead { + res.ContentLength = 0 } - if streamEnded || isHead { + if cs.isHead { res.Body = noBody return res, nil } - cs.bufPipe = pipe{b: &dataBuffer{expected: res.ContentLength}} + if f.StreamEnded() { + if res.ContentLength > 0 { + res.Body = missingBody{} + } else { + res.Body = noBody + } + return res, nil + } + + cs.bufPipe.setBuffer(&dataBuffer{expected: res.ContentLength}) cs.bytesRemain = res.ContentLength res.Body = transportResponseBody{cs} - go cs.awaitRequestCancel(cs.req) if cs.requestedGzip && res.Header.Get("Content-Encoding") == "gzip" { res.Header.Del("Content-Encoding") @@ -2088,8 +2352,7 @@ func (rl *clientConnReadLoop) processTrailers(cs *clientStream, f *MetaHeadersFr } // transportResponseBody is the concrete type of Transport.RoundTrip's -// Response.Body. It is an io.ReadCloser. On Read, it reads from cs.body. -// On Close it sends RST_STREAM if EOF wasn't already seen. +// Response.Body. It is an io.ReadCloser. type transportResponseBody struct { cs *clientStream } @@ -2107,7 +2370,7 @@ func (b transportResponseBody) Read(p []byte) (n int, err error) { n = int(cs.bytesRemain) if err == nil { err = errors.New("net/http: server replied with more than declared Content-Length; truncated") - cc.writeStreamReset(cs.ID, ErrCodeProtocol, err) + cs.abortStream(err) } cs.readErr = err return int(cs.bytesRemain), err @@ -2125,8 +2388,6 @@ func (b transportResponseBody) Read(p []byte) (n int, err error) { } cc.mu.Lock() - defer cc.mu.Unlock() - var connAdd, streamAdd int32 // Check the conn-level first, before the stream-level. if v := cc.inflow.available(); v < transportDefaultConnFlow/2 { @@ -2143,6 +2404,8 @@ func (b transportResponseBody) Read(p []byte) (n int, err error) { cs.inflow.add(streamAdd) } } + cc.mu.Unlock() + if connAdd != 0 || streamAdd != 0 { cc.wmu.Lock() defer cc.wmu.Unlock() @@ -2163,34 +2426,42 @@ func (b transportResponseBody) Close() error { cs := b.cs cc := cs.cc - serverSentStreamEnd := cs.bufPipe.Err() == io.EOF unread := cs.bufPipe.Len() - - if unread > 0 || !serverSentStreamEnd { + if unread > 0 { cc.mu.Lock() - cc.wmu.Lock() - if !serverSentStreamEnd { - cc.fr.WriteRSTStream(cs.ID, ErrCodeCancel) - cs.didReset = true - } // Return connection-level flow control. if unread > 0 { cc.inflow.add(int32(unread)) + } + cc.mu.Unlock() + + // TODO(dneil): Acquiring this mutex can block indefinitely. + // Move flow control return to a goroutine? + cc.wmu.Lock() + // Return connection-level flow control. + if unread > 0 { cc.fr.WriteWindowUpdate(0, uint32(unread)) } cc.bw.Flush() cc.wmu.Unlock() - cc.mu.Unlock() } cs.bufPipe.BreakWithError(errClosedResponseBody) - cc.forgetStreamID(cs.ID) + cs.abortStream(errClosedResponseBody) + + select { + case <-cs.donec: + case <-cs.ctx.Done(): + return cs.ctx.Err() + case <-cs.reqCancel: + return errRequestCanceled + } return nil } func (rl *clientConnReadLoop) processData(f *DataFrame) error { cc := rl.cc - cs := cc.streamByID(f.StreamID, f.StreamEnded()) + cs := rl.streamByID(f.StreamID) data := f.Data() if cs == nil { cc.mu.Lock() @@ -2219,6 +2490,14 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error { } return nil } + if cs.readClosed { + cc.logf("protocol error: received DATA after END_STREAM") + rl.endStreamError(cs, StreamError{ + StreamID: f.StreamID, + Code: ErrCodeProtocol, + }) + return nil + } if !cs.firstByte { cc.logf("protocol error: received DATA before a HEADERS frame") rl.endStreamError(cs, StreamError{ @@ -2228,7 +2507,7 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error { return nil } if f.Length > 0 { - if cs.req.Method == "HEAD" && len(data) > 0 { + if cs.isHead && len(data) > 0 { cc.logf("protocol error: received DATA on a HEAD request") rl.endStreamError(cs, StreamError{ StreamID: f.StreamID, @@ -2250,30 +2529,39 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error { if pad := int(f.Length) - len(data); pad > 0 { refund += pad } - // Return len(data) now if the stream is already closed, - // since data will never be read. - didReset := cs.didReset - if didReset { - refund += len(data) + + didReset := false + var err error + if len(data) > 0 { + if _, err = cs.bufPipe.Write(data); err != nil { + // Return len(data) now if the stream is already closed, + // since data will never be read. + didReset = true + refund += len(data) + } } + if refund > 0 { cc.inflow.add(int32(refund)) + if !didReset { + cs.inflow.add(int32(refund)) + } + } + cc.mu.Unlock() + + if refund > 0 { cc.wmu.Lock() cc.fr.WriteWindowUpdate(0, uint32(refund)) if !didReset { - cs.inflow.add(int32(refund)) cc.fr.WriteWindowUpdate(cs.ID, uint32(refund)) } cc.bw.Flush() cc.wmu.Unlock() } - cc.mu.Unlock() - if len(data) > 0 && !didReset { - if _, err := cs.bufPipe.Write(data); err != nil { - rl.endStreamError(cs, err) - return err - } + if err != nil { + rl.endStreamError(cs, err) + return nil } } @@ -2286,24 +2574,32 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error { func (rl *clientConnReadLoop) endStream(cs *clientStream) { // TODO: check that any declared content-length matches, like // server.go's (*stream).endStream method. - rl.endStreamError(cs, nil) + if !cs.readClosed { + cs.readClosed = true + // Close cs.bufPipe and cs.peerClosed with cc.mu held to avoid a + // race condition: The caller can read io.EOF from Response.Body + // and close the body before we close cs.peerClosed, causing + // cleanupWriteRequest to send a RST_STREAM. + rl.cc.mu.Lock() + defer rl.cc.mu.Unlock() + cs.bufPipe.closeWithErrorAndCode(io.EOF, cs.copyTrailers) + close(cs.peerClosed) + } } func (rl *clientConnReadLoop) endStreamError(cs *clientStream, err error) { - var code func() - if err == nil { - err = io.EOF - code = cs.copyTrailers - } - if isConnectionCloseRequest(cs.req) { - rl.closeWhenIdle = true - } - cs.bufPipe.closeWithErrorAndCode(err, code) + cs.readAborted = true + cs.abortStream(err) +} - select { - case cs.resc <- resAndError{err: err}: - default: +func (rl *clientConnReadLoop) streamByID(id uint32) *clientStream { + rl.cc.mu.Lock() + defer rl.cc.mu.Unlock() + cs := rl.cc.streams[id] + if cs != nil && !cs.readAborted { + return cs } + return nil } func (cs *clientStream) copyTrailers() { @@ -2322,6 +2618,10 @@ func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error { if f.ErrCode != 0 { // TODO: deal with GOAWAY more. particularly the error code cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode) + if fn := cc.t.CountError; fn != nil { + fn("recv_goaway_" + f.ErrCode.stringToken()) + } + } cc.setGoAway(f) return nil @@ -2329,6 +2629,23 @@ func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error { func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error { cc := rl.cc + // Locking both mu and wmu here allows frame encoding to read settings with only wmu held. + // Acquiring wmu when f.IsAck() is unnecessary, but convenient and mostly harmless. + cc.wmu.Lock() + defer cc.wmu.Unlock() + + if err := rl.processSettingsNoWrite(f); err != nil { + return err + } + if !f.IsAck() { + cc.fr.WriteSettingsAck() + cc.bw.Flush() + } + return nil +} + +func (rl *clientConnReadLoop) processSettingsNoWrite(f *SettingsFrame) error { + cc := rl.cc cc.mu.Lock() defer cc.mu.Unlock() @@ -2340,12 +2657,14 @@ func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error { return ConnectionError(ErrCodeProtocol) } + var seenMaxConcurrentStreams bool err := f.ForeachSetting(func(s Setting) error { switch s.ID { case SettingMaxFrameSize: cc.maxFrameSize = s.Val case SettingMaxConcurrentStreams: cc.maxConcurrentStreams = s.Val + seenMaxConcurrentStreams = true case SettingMaxHeaderListSize: cc.peerMaxHeaderListSize = uint64(s.Val) case SettingInitialWindowSize: @@ -2377,17 +2696,23 @@ func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error { return err } - cc.wmu.Lock() - defer cc.wmu.Unlock() + if !cc.seenSettings { + if !seenMaxConcurrentStreams { + // This was the servers initial SETTINGS frame and it + // didn't contain a MAX_CONCURRENT_STREAMS field so + // increase the number of concurrent streams this + // connection can establish to our default. + cc.maxConcurrentStreams = defaultMaxConcurrentStreams + } + cc.seenSettings = true + } - cc.fr.WriteSettingsAck() - cc.bw.Flush() - return cc.werr + return nil } func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error { cc := rl.cc - cs := cc.streamByID(f.StreamID, false) + cs := rl.streamByID(f.StreamID) if f.StreamID != 0 && cs == nil { return nil } @@ -2407,24 +2732,22 @@ func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error { } func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error { - cs := rl.cc.streamByID(f.StreamID, true) + cs := rl.streamByID(f.StreamID) if cs == nil { - // TODO: return error if server tries to RST_STEAM an idle stream + // TODO: return error if server tries to RST_STREAM an idle stream return nil } - select { - case <-cs.peerReset: - // Already reset. - // This is the only goroutine - // which closes this, so there - // isn't a race. - default: - err := streamError(cs.ID, f.ErrCode) - cs.resetErr = err - close(cs.peerReset) - cs.bufPipe.CloseWithError(err) - cs.cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl + serr := streamError(cs.ID, f.ErrCode) + serr.Cause = errFromPeer + if f.ErrCode == ErrCodeProtocol { + rl.cc.SetDoNotReuse() } + if fn := cs.cc.t.CountError; fn != nil { + fn("recv_rststream_" + f.ErrCode.stringToken()) + } + cs.abortStream(serr) + + cs.bufPipe.CloseWithError(serr) return nil } @@ -2446,19 +2769,24 @@ func (cc *ClientConn) Ping(ctx context.Context) error { } cc.mu.Unlock() } - cc.wmu.Lock() - if err := cc.fr.WritePing(false, p); err != nil { - cc.wmu.Unlock() - return err - } - if err := cc.bw.Flush(); err != nil { - cc.wmu.Unlock() - return err - } - cc.wmu.Unlock() + errc := make(chan error, 1) + go func() { + cc.wmu.Lock() + defer cc.wmu.Unlock() + if err := cc.fr.WritePing(false, p); err != nil { + errc <- err + return + } + if err := cc.bw.Flush(); err != nil { + errc <- err + return + } + }() select { case <-c: return nil + case err := <-errc: + return err case <-ctx.Done(): return ctx.Err() case <-cc.readerDone: @@ -2535,6 +2863,11 @@ func (t *Transport) logf(format string, args ...interface{}) { var noBody io.ReadCloser = ioutil.NopCloser(bytes.NewReader(nil)) +type missingBody struct{} + +func (missingBody) Close() error { return nil } +func (missingBody) Read([]byte) (int, error) { return 0, io.ErrUnexpectedEOF } + func strSliceContains(ss []string, s string) bool { for _, v := range ss { if v == s { @@ -2580,87 +2913,6 @@ type errorReader struct{ err error } func (r errorReader) Read(p []byte) (int, error) { return 0, r.err } -// bodyWriterState encapsulates various state around the Transport's writing -// of the request body, particularly regarding doing delayed writes of the body -// when the request contains "Expect: 100-continue". -type bodyWriterState struct { - cs *clientStream - timer *time.Timer // if non-nil, we're doing a delayed write - fnonce *sync.Once // to call fn with - fn func() // the code to run in the goroutine, writing the body - resc chan error // result of fn's execution - delay time.Duration // how long we should delay a delayed write for -} - -func (t *Transport) getBodyWriterState(cs *clientStream, body io.Reader) (s bodyWriterState) { - s.cs = cs - if body == nil { - return - } - resc := make(chan error, 1) - s.resc = resc - s.fn = func() { - cs.cc.mu.Lock() - cs.startedWrite = true - cs.cc.mu.Unlock() - resc <- cs.writeRequestBody(body, cs.req.Body) - } - s.delay = t.expectContinueTimeout() - if s.delay == 0 || - !httpguts.HeaderValuesContainsToken( - cs.req.Header["Expect"], - "100-continue") { - return - } - s.fnonce = new(sync.Once) - - // Arm the timer with a very large duration, which we'll - // intentionally lower later. It has to be large now because - // we need a handle to it before writing the headers, but the - // s.delay value is defined to not start until after the - // request headers were written. - const hugeDuration = 365 * 24 * time.Hour - s.timer = time.AfterFunc(hugeDuration, func() { - s.fnonce.Do(s.fn) - }) - return -} - -func (s bodyWriterState) cancel() { - if s.timer != nil { - if s.timer.Stop() { - s.resc <- nil - } - } -} - -func (s bodyWriterState) on100() { - if s.timer == nil { - // If we didn't do a delayed write, ignore the server's - // bogus 100 continue response. - return - } - s.timer.Stop() - go func() { s.fnonce.Do(s.fn) }() -} - -// scheduleBodyWrite starts writing the body, either immediately (in -// the common case) or after the delay timeout. It should not be -// called until after the headers have been written. -func (s bodyWriterState) scheduleBodyWrite() { - if s.timer == nil { - // We're not doing a delayed write (see - // getBodyWriterState), so just start the writing - // goroutine immediately. - go s.fn() - return - } - traceWait100Continue(s.cs.trace) - if s.timer.Stop() { - s.timer.Reset(s.delay) - } -} - // isConnectionCloseRequest reports whether req should use its own // connection for a single request and then close the connection. func isConnectionCloseRequest(req *http.Request) bool { |