diff options
Diffstat (limited to 'vendor/golang.org/x/net/http2/transport.go')
| -rw-r--r-- | vendor/golang.org/x/net/http2/transport.go | 3066 |
1 files changed, 3066 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/transport.go b/vendor/golang.org/x/net/http2/transport.go new file mode 100644 index 000000000..90fdc28cf --- /dev/null +++ b/vendor/golang.org/x/net/http2/transport.go @@ -0,0 +1,3066 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Transport code. + +package http2 + +import ( + "bufio" + "bytes" + "compress/gzip" + "context" + "crypto/rand" + "crypto/tls" + "errors" + "fmt" + "io" + "log" + "math" + mathrand "math/rand" + "net" + "net/http" + "net/http/httptrace" + "net/textproto" + "os" + "sort" + "strconv" + "strings" + "sync" + "sync/atomic" + "time" + + "golang.org/x/net/http/httpguts" + "golang.org/x/net/http2/hpack" + "golang.org/x/net/idna" +) + +const ( + // transportDefaultConnFlow is how many connection-level flow control + // tokens we give the server at start-up, past the default 64k. + transportDefaultConnFlow = 1 << 30 + + // transportDefaultStreamFlow is how many stream-level flow + // control tokens we announce to the peer, and how many bytes + // we buffer per stream. + transportDefaultStreamFlow = 4 << 20 + + // transportDefaultStreamMinRefresh is the minimum number of bytes we'll send + // a stream-level WINDOW_UPDATE for at a time. + 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. +// +// A Transport internally caches connections to servers. It is safe +// for concurrent use by multiple goroutines. +type Transport struct { + // DialTLSContext specifies an optional dial function with context for + // creating TLS connections for requests. + // + // If DialTLSContext and DialTLS is nil, tls.Dial is used. + // + // If the returned net.Conn has a ConnectionState method like tls.Conn, + // it will be used to set http.Response.TLS. + DialTLSContext func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) + + // DialTLS specifies an optional dial function for creating + // TLS connections for requests. + // + // If DialTLSContext and DialTLS is nil, tls.Dial is used. + // + // Deprecated: Use DialTLSContext instead, which allows the transport + // to cancel dials as soon as they are no longer needed. + // If both are set, DialTLSContext takes priority. + DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error) + + // TLSClientConfig specifies the TLS configuration to use with + // tls.Client. If nil, the default configuration is used. + TLSClientConfig *tls.Config + + // ConnPool optionally specifies an alternate connection pool to use. + // If nil, the default is used. + ConnPool ClientConnPool + + // DisableCompression, if true, prevents the Transport from + // requesting compression with an "Accept-Encoding: gzip" + // request header when the Request contains no existing + // Accept-Encoding value. If the Transport requests gzip on + // its own and gets a gzipped response, it's transparently + // decoded in the Response.Body. However, if the user + // explicitly requested gzip it is not automatically + // uncompressed. + DisableCompression bool + + // AllowHTTP, if true, permits HTTP/2 requests using the insecure, + // plain-text "http" scheme. Note that this does not enable h2c support. + AllowHTTP bool + + // MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to + // send in the initial settings frame. It is how many bytes + // of response headers are allowed. Unlike the http2 spec, zero here + // means to use a default limit (currently 10MB). If you actually + // want to advertise an unlimited value to the peer, Transport + // interprets the highest possible value here (0xffffffff or 1<<32-1) + // to mean no limit. + MaxHeaderListSize uint32 + + // StrictMaxConcurrentStreams controls whether the server's + // SETTINGS_MAX_CONCURRENT_STREAMS should be respected + // globally. If false, new TCP connections are created to the + // server as needed to keep each under the per-connection + // SETTINGS_MAX_CONCURRENT_STREAMS limit. If true, the + // server's SETTINGS_MAX_CONCURRENT_STREAMS is interpreted as + // a global limit and callers of RoundTrip block when needed, + // waiting for their turn. + StrictMaxConcurrentStreams bool + + // ReadIdleTimeout is the timeout after which a health check using ping + // frame will be carried out if no frame is received on the connection. + // Note that a ping response will is considered a received frame, so if + // there is no other traffic on the connection, the health check will + // be performed every ReadIdleTimeout interval. + // If zero, no health check is performed. + ReadIdleTimeout time.Duration + + // PingTimeout is the timeout after which the connection will be closed + // if a response to Ping is not received. + // 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). + t1 *http.Transport + + connPoolOnce sync.Once + connPoolOrDef ClientConnPool // non-nil version of ConnPool +} + +func (t *Transport) maxHeaderListSize() uint32 { + if t.MaxHeaderListSize == 0 { + return 10 << 20 + } + if t.MaxHeaderListSize == 0xffffffff { + return 0 + } + return t.MaxHeaderListSize +} + +func (t *Transport) disableCompression() bool { + return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression) +} + +func (t *Transport) pingTimeout() time.Duration { + if t.PingTimeout == 0 { + return 15 * time.Second + } + return t.PingTimeout + +} + +// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2. +// It returns an error if t1 has already been HTTP/2-enabled. +// +// Use ConfigureTransports instead to configure the HTTP/2 Transport. +func ConfigureTransport(t1 *http.Transport) error { + _, err := ConfigureTransports(t1) + return err +} + +// ConfigureTransports configures a net/http HTTP/1 Transport to use HTTP/2. +// It returns a new HTTP/2 Transport for further configuration. +// It returns an error if t1 has already been HTTP/2-enabled. +func ConfigureTransports(t1 *http.Transport) (*Transport, error) { + return configureTransports(t1) +} + +func configureTransports(t1 *http.Transport) (*Transport, error) { + connPool := new(clientConnPool) + t2 := &Transport{ + ConnPool: noDialClientConnPool{connPool}, + t1: t1, + } + connPool.t = t2 + if err := registerHTTPSProtocol(t1, noDialH2RoundTripper{t2}); err != nil { + return nil, err + } + if t1.TLSClientConfig == nil { + t1.TLSClientConfig = new(tls.Config) + } + if !strSliceContains(t1.TLSClientConfig.NextProtos, "h2") { + t1.TLSClientConfig.NextProtos = append([]string{"h2"}, t1.TLSClientConfig.NextProtos...) + } + if !strSliceContains(t1.TLSClientConfig.NextProtos, "http/1.1") { + t1.TLSClientConfig.NextProtos = append(t1.TLSClientConfig.NextProtos, "http/1.1") + } + upgradeFn := func(authority string, c *tls.Conn) http.RoundTripper { + addr := authorityAddr("https", authority) + if used, err := connPool.addConnIfNeeded(addr, t2, c); err != nil { + go c.Close() + return erringRoundTripper{err} + } else if !used { + // Turns out we don't need this c. + // For example, two goroutines made requests to the same host + // at the same time, both kicking off TCP dials. (since protocol + // was unknown) + go c.Close() + } + return t2 + } + if m := t1.TLSNextProto; len(m) == 0 { + t1.TLSNextProto = map[string]func(string, *tls.Conn) http.RoundTripper{ + "h2": upgradeFn, + } + } else { + m["h2"] = upgradeFn + } + return t2, nil +} + +func (t *Transport) connPool() ClientConnPool { + t.connPoolOnce.Do(t.initConnPool) + return t.connPoolOrDef +} + +func (t *Transport) initConnPool() { + if t.ConnPool != nil { + t.connPoolOrDef = t.ConnPool + } else { + t.connPoolOrDef = &clientConnPool{t: t} + } +} + +// 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 + getConnCalled bool // used by clientConnPool + + // readLoop goroutine fields: + readerDone chan struct{} // closed on error + readerErr error // set before readerDone is closed + + idleTimeout time.Duration // or 0 for never + idleTimer *time.Timer + + mu sync.Mutex // guards following + 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 + br *bufio.Reader + lastActive time.Time + lastIdle time.Time // time last idle + // 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 +} + +// 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 + + // 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 + bufPipe pipe // buffered pipe with the flow-controlled response payload + requestedGzip bool + 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 + + reqBody io.ReadCloser + reqBodyContentLength int64 // -1 means unknown + reqBodyClosed bool // body has been closed; 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 +} + +var got1xxFuncForTests func(int, textproto.MIMEHeader) error + +// get1xxTraceFunc returns the value of request's httptrace.ClientTrace.Got1xxResponse func, +// if any. It returns nil if not set or if the Go version is too old. +func (cs *clientStream) get1xxTraceFunc() func(int, textproto.MIMEHeader) error { + if fn := got1xxFuncForTests; fn != nil { + return fn + } + return traceGot1xxResponseFunc(cs.trace) +} + +func (cs *clientStream) abortStream(err error) { + cs.cc.mu.Lock() + defer cs.cc.mu.Unlock() + cs.abortStreamLocked(err) +} + +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 + } + // 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) abortRequestBodyWrite() { + cc := cs.cc + cc.mu.Lock() + defer cc.mu.Unlock() + if cs.reqBody != nil && !cs.reqBodyClosed { + cs.reqBody.Close() + cs.reqBodyClosed = true + cc.cond.Broadcast() + } +} + +type stickyErrWriter struct { + 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 + } + 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 +// needs to be detected by net/http regardless of whether it's its +// bundled version (in h2_bundle.go with a rewritten type name) or +// from a user's x/net/http2. As such, as it has a unique method name +// (IsHTTP2NoCachedConnError) that net/http sniffs for via func +// isNoCachedConnError. +type noCachedConnError struct{} + +func (noCachedConnError) IsHTTP2NoCachedConnError() {} +func (noCachedConnError) Error() string { return "http2: no cached connection was available" } + +// isNoCachedConnError reports whether err is of type noCachedConnError +// or its equivalent renamed type in net/http2's h2_bundle.go. Both types +// may coexist in the same running program. +func isNoCachedConnError(err error) bool { + _, ok := err.(interface{ IsHTTP2NoCachedConnError() }) + return ok +} + +var ErrNoCachedConn error = noCachedConnError{} + +// RoundTripOpt are options for the Transport.RoundTripOpt method. +type RoundTripOpt struct { + // OnlyCachedConn controls whether RoundTripOpt may + // create a new TCP connection. If set true and + // no cached connection is available, RoundTripOpt + // will return ErrNoCachedConn. + OnlyCachedConn bool +} + +func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) { + return t.RoundTripOpt(req, RoundTripOpt{}) +} + +// authorityAddr returns a given authority (a host/IP, or host:port / ip:port) +// and returns a host:port. The port 443 is added if needed. +func authorityAddr(scheme string, authority string) (addr string) { + host, port, err := net.SplitHostPort(authority) + if err != nil { // authority didn't have a port + port = "443" + if scheme == "http" { + port = "80" + } + host = authority + } + if a, err := idna.ToASCII(host); err == nil { + host = a + } + // IPv6 address literal, without a port: + if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") { + return host + ":" + port + } + return net.JoinHostPort(host, port) +} + +// RoundTripOpt is like RoundTrip, but takes options. +func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) { + if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) { + return nil, errors.New("http2: unsupported scheme") + } + + addr := authorityAddr(req.URL.Scheme, req.URL.Host) + for retry := 0; ; retry++ { + cc, err := t.connPool().GetClientConn(req, addr) + if err != nil { + t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err) + return nil, err + } + reused := !atomic.CompareAndSwapUint32(&cc.reused, 0, 1) + traceGotConn(req, cc, reused) + res, err := cc.RoundTrip(req) + if err != nil && retry <= 6 { + if req, err = shouldRetryRequest(req, err); err == nil { + // After the first retry, do exponential backoff with 10% jitter. + if retry == 0 { + t.vlogf("RoundTrip retrying after failure: %v", err) + continue + } + backoff := float64(uint(1) << (uint(retry) - 1)) + backoff += backoff * (0.1 * mathrand.Float64()) + select { + case <-time.After(time.Second * time.Duration(backoff)): + t.vlogf("RoundTrip retrying after failure: %v", err) + continue + case <-req.Context().Done(): + err = req.Context().Err() + } + } + } + if err != nil { + t.vlogf("RoundTrip failure: %v", err) + return nil, err + } + return res, nil + } +} + +// CloseIdleConnections closes any connections which were previously +// connected from previous requests but are now sitting idle. +// It does not interrupt any connections currently in use. +func (t *Transport) CloseIdleConnections() { + if cp, ok := t.connPool().(clientConnPoolIdleCloser); ok { + cp.closeIdleConnections() + } +} + +var ( + errClientConnClosed = errors.New("http2: client conn is closed") + errClientConnUnusable = errors.New("http2: client conn not usable") + errClientConnGotGoAway = errors.New("http2: Transport received Server's graceful shutdown GOAWAY") +) + +// shouldRetryRequest is called by RoundTrip when a request fails to get +// 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) (*http.Request, error) { + if !canRetryError(err) { + return nil, err + } + // If the Body is nil (or http.NoBody), it's safe to reuse + // this request and its Body. + if req.Body == nil || req.Body == http.NoBody { + return req, nil + } + + // If the request body can be reset back to its original + // state via the optional req.GetBody, do that. + if req.GetBody != nil { + body, err := req.GetBody() + if err != nil { + return nil, err + } + newReq := *req + newReq.Body = body + return &newReq, nil + } + + // 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. + if err == errClientConnUnusable { + return req, nil + } + + return nil, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err) +} + +func canRetryError(err error) bool { + if err == errClientConnUnusable || err == errClientConnGotGoAway { + 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 +} + +func (t *Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*ClientConn, error) { + host, _, err := net.SplitHostPort(addr) + if err != nil { + return nil, err + } + tconn, err := t.dialTLS(ctx, "tcp", addr, t.newTLSConfig(host)) + if err != nil { + return nil, err + } + return t.newClientConn(tconn, singleUse) +} + +func (t *Transport) newTLSConfig(host string) *tls.Config { + cfg := new(tls.Config) + if t.TLSClientConfig != nil { + *cfg = *t.TLSClientConfig.Clone() + } + if !strSliceContains(cfg.NextProtos, NextProtoTLS) { + cfg.NextProtos = append([]string{NextProtoTLS}, cfg.NextProtos...) + } + if cfg.ServerName == "" { + cfg.ServerName = host + } + return cfg +} + +func (t *Transport) dialTLS(ctx context.Context, network, addr string, tlsCfg *tls.Config) (net.Conn, error) { + if t.DialTLSContext != nil { + return t.DialTLSContext(ctx, network, addr, tlsCfg) + } else if t.DialTLS != nil { + return t.DialTLS(network, addr, tlsCfg) + } + + tlsCn, err := t.dialTLSWithContext(ctx, network, addr, tlsCfg) + if err != nil { + return nil, err + } + state := tlsCn.ConnectionState() + if p := state.NegotiatedProtocol; p != NextProtoTLS { + return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS) + } + if !state.NegotiatedProtocolIsMutual { + return nil, errors.New("http2: could not negotiate protocol mutually") + } + return tlsCn, nil +} + +// disableKeepAlives reports whether connections should be closed as +// soon as possible after handling the first request. +func (t *Transport) disableKeepAlives() bool { + return t.t1 != nil && t.t1.DisableKeepAlives +} + +func (t *Transport) expectContinueTimeout() time.Duration { + if t.t1 == nil { + return 0 + } + return t.t1.ExpectContinueTimeout +} + +func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) { + return t.newClientConn(c, t.disableKeepAlives()) +} + +func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, error) { + cc := &ClientConn{ + t: t, + tconn: c, + readerDone: make(chan struct{}), + nextStreamID: 1, + 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 + cc.idleTimer = time.AfterFunc(d, cc.onIdleTimeout) + } + if VerboseLogs { + t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr()) + } + + cc.cond = sync.NewCond(&cc.mu) + cc.flow.add(int32(initialWindowSize)) + + // TODO: adjust this writer size to account for frame size + + // MTU + crypto/tls record padding. + 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() + + // TODO: SetMaxDynamicTableSize, SetMaxDynamicTableSizeLimit on + // henc in response to SETTINGS frames? + cc.henc = hpack.NewEncoder(&cc.hbuf) + + if t.AllowHTTP { + cc.nextStreamID = 3 + } + + if cs, ok := c.(connectionStater); ok { + state := cs.ConnectionState() + cc.tlsState = &state + } + + initialSettings := []Setting{ + {ID: SettingEnablePush, Val: 0}, + {ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow}, + } + if max := t.maxHeaderListSize(); max != 0 { + initialSettings = append(initialSettings, Setting{ID: SettingMaxHeaderListSize, Val: max}) + } + + cc.bw.Write(clientPreface) + cc.fr.WriteSettings(initialSettings...) + cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow) + cc.inflow.add(transportDefaultConnFlow + initialWindowSize) + cc.bw.Flush() + if cc.werr != nil { + cc.Close() + return nil, cc.werr + } + + go cc.readLoop() + return cc, nil +} + +func (cc *ClientConn) healthCheck() { + pingTimeout := cc.t.pingTimeout() + // We don't need to periodically ping in the health check, because the readLoop of ClientConn will + // trigger the healthCheck again if there is no frame received. + ctx, cancel := context.WithTimeout(context.Background(), pingTimeout) + defer cancel() + cc.vlogf("http2: Transport sending health check") + err := cc.Ping(ctx) + if err != nil { + cc.vlogf("http2: Transport health check failure: %v", err) + cc.closeForLostPing() + } else { + cc.vlogf("http2: Transport health check success") + } +} + +// 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() + + old := cc.goAway + cc.goAway = f + + // Merge the previous and current GoAway error frames. + if cc.goAwayDebug == "" { + cc.goAwayDebug = string(f.DebugData()) + } + if old != nil && old.ErrCode != ErrCodeNo { + cc.goAway.ErrCode = old.ErrCode + } + last := f.LastStreamID + for streamID, cs := range cc.streams { + if streamID > last { + 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 +} + +func (cc *ClientConn) idleState() clientConnIdleState { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.idleStateLocked() +} + +func (cc *ClientConn) idleStateLocked() (st clientConnIdleState) { + if cc.singleUse && cc.nextStreamID > 1 { + return + } + var maxConcurrentOkay bool + if cc.t.StrictMaxConcurrentStreams { + // We'll tell the caller we can take a new request to + // prevent the caller from dialing a new TCP + // connection, but then we'll block later before + // writing it. + maxConcurrentOkay = true + } else { + 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() + return +} + +func (cc *ClientConn) canTakeNewRequestLocked() bool { + st := cc.idleStateLocked() + return st.canTakeNewRequest +} + +// tooIdleLocked reports whether this connection has been been sitting idle +// for too much wall time. +func (cc *ClientConn) tooIdleLocked() bool { + // The Round(0) strips the monontonic clock reading so the + // times are compared based on their wall time. We don't want + // to reuse a connection that's been sitting idle during + // VM/laptop suspend if monotonic time was also frozen. + return cc.idleTimeout != 0 && !cc.lastIdle.IsZero() && time.Since(cc.lastIdle.Round(0)) > cc.idleTimeout +} + +// onIdleTimeout is called from a time.AfterFunc goroutine. It will +// only be called when we're idle, but because we're coming from a new +// goroutine, there could be a new request coming in at the same time, +// so this simply calls the synchronized closeIfIdle to shut down this +// connection. The timer could just call closeIfIdle, but this is more +// clear. +func (cc *ClientConn) onIdleTimeout() { + cc.closeIfIdle() +} + +func (cc *ClientConn) closeConn() error { + t := time.AfterFunc(250*time.Millisecond, cc.forceCloseConn) + defer t.Stop() + return cc.tconn.Close() +} + +// A tls.Conn.Close can hang for a long time if the peer is unresponsive. +// Try to shut it down more aggressively. +func (cc *ClientConn) forceCloseConn() { + tc, ok := cc.tconn.(*tls.Conn) + if !ok { + return + } + if nc := tlsUnderlyingConn(tc); nc != nil { + nc.Close() + } +} + +func (cc *ClientConn) closeIfIdle() { + cc.mu.Lock() + if len(cc.streams) > 0 || cc.streamsReserved > 0 { + cc.mu.Unlock() + return + } + cc.closed = true + nextID := cc.nextStreamID + // TODO: do clients send GOAWAY too? maybe? Just Close: + cc.mu.Unlock() + + if VerboseLogs { + cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, nextID-2) + } + cc.closeConn() +} + +func (cc *ClientConn) isDoNotReuseAndIdle() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.doNotReuse && len(cc.streams) == 0 +} + +var shutdownEnterWaitStateHook = func() {} + +// 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 + } + // Wait for all in-flight streams to complete or connection to close + done := make(chan struct{}) + cancelled := false // guarded by cc.mu + go func() { + cc.mu.Lock() + defer cc.mu.Unlock() + for { + if len(cc.streams) == 0 || cc.closed { + cc.closed = true + close(done) + break + } + if cancelled { + break + } + cc.cond.Wait() + } + }() + shutdownEnterWaitStateHook() + select { + case <-done: + return cc.closeConn() + case <-ctx.Done(): + cc.mu.Lock() + // Free the goroutine above + cancelled = true + cc.cond.Broadcast() + cc.mu.Unlock() + return ctx.Err() + } +} + +func (cc *ClientConn) sendGoAway() error { + cc.mu.Lock() + 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 + if err := cc.fr.WriteGoAway(maxStreamID, ErrCodeNo, nil); err != nil { + return err + } + if err := cc.bw.Flush(); err != nil { + return err + } + // Prevent new requests + return nil +} + +// closes the client connection immediately. In-flight requests are interrupted. +// 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) + } + cc.cond.Broadcast() + cc.mu.Unlock() + return cc.closeConn() +} + +// Close closes the client connection immediately. +// +// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead. +func (cc *ClientConn) Close() error { + err := errors.New("http2: client connection force closed via ClientConn.Close") + return cc.closeForError(err) +} + +// 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) +} + +// errRequestCanceled is a copy of net/http's errRequestCanceled because it's not +// exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests. +var errRequestCanceled = errors.New("net/http: request canceled") + +func commaSeparatedTrailers(req *http.Request) (string, error) { + keys := make([]string, 0, len(req.Trailer)) + for k := range req.Trailer { + k = http.CanonicalHeaderKey(k) + switch k { + case "Transfer-Encoding", "Trailer", "Content-Length": + return "", fmt.Errorf("invalid Trailer key %q", k) + } + keys = append(keys, k) + } + if len(keys) > 0 { + sort.Strings(keys) + return strings.Join(keys, ","), nil + } + return "", nil +} + +func (cc *ClientConn) responseHeaderTimeout() time.Duration { + if cc.t.t1 != nil { + return cc.t.t1.ResponseHeaderTimeout + } + // No way to do this (yet?) with just an http2.Transport. Probably + // no need. Request.Cancel this is the new way. We only need to support + // this for compatibility with the old http.Transport fields when + // we're doing transparent http2. + return 0 +} + +// checkConnHeaders checks whether req has any invalid connection-level headers. +// per RFC 7540 section 8.1.2.2: Connection-Specific Header Fields. +// Certain headers are special-cased as okay but not transmitted later. +func checkConnHeaders(req *http.Request) error { + if v := req.Header.Get("Upgrade"); v != "" { + return fmt.Errorf("http2: invalid Upgrade request header: %q", req.Header["Upgrade"]) + } + if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") { + return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv) + } + if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !asciiEqualFold(vv[0], "close") && !asciiEqualFold(vv[0], "keep-alive")) { + return fmt.Errorf("http2: invalid Connection request header: %q", vv) + } + return nil +} + +// actualContentLength returns a sanitized version of +// req.ContentLength, where 0 actually means zero (not unknown) and -1 +// means unknown. +func actualContentLength(req *http.Request) int64 { + if req.Body == nil || req.Body == http.NoBody { + return 0 + } + if req.ContentLength != 0 { + return req.ContentLength + } + 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) { + 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 + } + } + + handleResponseHeaders := func() (*http.Response, error) { + 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 + } + + for { + select { + case <-cs.respHeaderRecv: + return handleResponseHeaders() + case <-cs.abort: + select { + case <-cs.respHeaderRecv: + // If both cs.respHeaderRecv and cs.abort are signaling, + // pick respHeaderRecv. The server probably wrote the + // response and immediately reset the stream. + // golang.org/issue/49645 + return handleResponseHeaders() + default: + 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) +} + +// 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 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() + } + + cc.mu.Lock() + if cc.idleTimer != nil { + cc.idleTimer.Stop() + } + cc.decrStreamReservationsLocked() + if err := cc.awaitOpenSlotForStreamLocked(cs); err != nil { + cc.mu.Unlock() + <-cc.reqHeaderMu + return err + } + cc.addStreamLocked(cs) // assigns stream ID + if isConnectionCloseRequest(req) { + cc.doNotReuse = true + } + cc.mu.Unlock() + + // TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere? + if !cc.t.disableCompression() && + req.Header.Get("Accept-Encoding") == "" && + req.Header.Get("Range") == "" && + !cs.isHead { + // Request gzip only, not deflate. Deflate is ambiguous and + // not as universally supported anyway. + // See: https://zlib.net/zlib_faq.html#faq39 + // + // Note that we don't request this for HEAD requests, + // due to a bug in nginx: + // http://trac.nginx.org/nginx/ticket/358 + // https://golang.org/issue/5522 + // + // 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 + cs.requestedGzip = true + } + + continueTimeout := cc.t.expectContinueTimeout() + if continueTimeout != 0 { + if !httpguts.HeaderValuesContainsToken(req.Header["Expect"], "100-continue") { + continueTimeout = 0 + } else { + 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 { + return err + } + + 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 + } + } + + 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: + respHeaderRecv = nil + 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 + cs.sentHeaders = true + err = cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs) + traceWroteHeaders(cs.trace) + return err +} + +// 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 + + if cs.ID == 0 { + // We were canceled before creating the stream, so return our reservation. + cc.decrStreamReservations() + } + + // 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() + } + + 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) + } + } + cs.bufPipe.CloseWithError(err) // no-op if already closed + } else { + if cs.sentHeaders && !cs.sentEndStream { + cc.writeStreamReset(cs.ID, ErrCodeNo, nil) + } + cs.bufPipe.CloseWithError(errRequestCanceled) + } + if cs.ID != 0 { + cc.forgetStreamID(cs.ID) + } + + cc.wmu.Lock() + werr := cc.werr + cc.wmu.Unlock() + if werr != nil { + cc.Close() + } + + close(cs.donec) +} + +// awaitOpenSlotForStream waits until len(streams) < maxConcurrentStreams. +// Must hold cc.mu. +func (cc *ClientConn) awaitOpenSlotForStreamLocked(cs *clientStream) error { + for { + cc.lastActive = time.Now() + if cc.closed || !cc.canTakeNewRequestLocked() { + return errClientConnUnusable + } + cc.lastIdle = time.Time{} + if int64(len(cc.streams)) < int64(cc.maxConcurrentStreams) { + return nil + } + cc.pendingRequests++ + cc.cond.Wait() + cc.pendingRequests-- + select { + case <-cs.abort: + return cs.abortErr + default: + } + } +} + +// requires cc.wmu be held +func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, maxFrameSize int, hdrs []byte) error { + first := true // first frame written (HEADERS is first, then CONTINUATION) + for len(hdrs) > 0 && cc.werr == nil { + chunk := hdrs + if len(chunk) > maxFrameSize { + chunk = chunk[:maxFrameSize] + } + hdrs = hdrs[len(chunk):] + endHeaders := len(hdrs) == 0 + if first { + cc.fr.WriteHeaders(HeadersFrameParam{ + StreamID: streamID, + BlockFragment: chunk, + EndStream: endStream, + EndHeaders: endHeaders, + }) + first = false + } else { + cc.fr.WriteContinuation(streamID, endHeaders, chunk) + } + } + cc.bw.Flush() + return cc.werr +} + +// internal error values; they don't escape to callers +var ( + // abort request body write; don't send cancel + errStopReqBodyWrite = errors.New("http2: aborting request body write") + + // abort request body write, but send stream reset of cancel. + errStopReqBodyWriteAndCancel = errors.New("http2: canceling request") + + errReqBodyTooLong = errors.New("http2: request body larger than specified content length") +) + +// frameScratchBufferLen returns the length of a buffer to use for +// outgoing request bodies to read/write to/from. +// +// It returns max(1, min(peer's advertised max frame size, +// Request.ContentLength+1, 512KB)). +func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int { + const max = 512 << 10 + n := int64(maxFrameSize) + if n > max { + n = max + } + 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 + // early. + n = cl + 1 + } + if n < 1 { + return 1 + } + return int(n) // doesn't truncate; max is 512K +} + +var bufPool sync.Pool // of *[]byte + +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 + + hasTrailers := req.Trailer != nil + remainLen := cs.reqBodyContentLength + hasContentLen := remainLen != -1 + + cc.mu.Lock() + maxFrameSize := int(cc.maxFrameSize) + cc.mu.Unlock() + + // Scratch buffer for reading into & writing from. + scratchLen := cs.frameScratchBufferLen(maxFrameSize) + var buf []byte + if bp, ok := bufPool.Get().(*[]byte); ok && len(*bp) >= scratchLen { + defer bufPool.Put(bp) + buf = *bp + } else { + buf = make([]byte, scratchLen) + defer bufPool.Put(&buf) + } + + var sawEOF bool + for !sawEOF { + n, err := body.Read(buf[:len(buf)]) + if hasContentLen { + remainLen -= int64(n) + if remainLen == 0 && err == nil { + // The request body's Content-Length was predeclared and + // we just finished reading it all, but the underlying io.Reader + // returned the final chunk with a nil error (which is one of + // the two valid things a Reader can do at EOF). Because we'd prefer + // to send the END_STREAM bit early, double-check that we're actually + // at EOF. Subsequent reads should return (0, EOF) at this point. + // If either value is different, we return an error in one of two ways below. + var scratch [1]byte + var n1 int + n1, err = body.Read(scratch[:]) + remainLen -= int64(n1) + } + if remainLen < 0 { + err = errReqBodyTooLong + 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)) + if err != nil { + return err + } + cc.wmu.Lock() + data := remain[:allowed] + remain = remain[allowed:] + sentEnd = sawEOF && len(remain) == 0 && !hasTrailers + err = cc.fr.WriteData(cs.ID, sentEnd, data) + if err == nil { + // TODO(bradfitz): this flush is for latency, not bandwidth. + // Most requests won't need this. Make this opt-in or + // opt-out? Use some heuristic on the body type? Nagel-like + // timers? Based on 'n'? Only last chunk of this for loop, + // unless flow control tokens are low? For now, always. + // If we change this, see comment below. + err = cc.bw.Flush() + } + cc.wmu.Unlock() + } + if err != nil { + return err + } + } + + if sentEnd { + // Already sent END_STREAM (which implies we have no + // trailers) and flushed, because currently all + // WriteData frames above get a flush. So we're done. + 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 len(trailer) > 0 { + trls, err = cc.encodeTrailers(trailer) + if err != nil { + return err + } + } + + // Two ways to send END_STREAM: either with trailers, or + // with an empty DATA frame. + if len(trls) > 0 { + err = cc.writeHeaders(cs.ID, true, maxFrameSize, trls) + } else { + err = cc.fr.WriteData(cs.ID, true, nil) + } + if ferr := cc.bw.Flush(); ferr != nil && err == nil { + err = ferr + } + return err +} + +// awaitFlowControl waits for [1, min(maxBytes, cc.cs.maxFrameSize)] flow +// control tokens from the server. +// It returns either the non-zero number of tokens taken or an error +// 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.reqBodyClosed { + return 0, errStopReqBodyWrite + } + 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 + if int(take) > maxBytes { + + take = int32(maxBytes) // can't truncate int; take is int32 + } + if take > int32(cc.maxFrameSize) { + take = int32(cc.maxFrameSize) + } + cs.flow.take(take) + return take, nil + } + cc.cond.Wait() + } +} + +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 == "" { + host = req.URL.Host + } + host, err := httpguts.PunycodeHostPort(host) + if err != nil { + return nil, err + } + + var path string + if req.Method != "CONNECT" { + path = req.URL.RequestURI() + if !validPseudoPath(path) { + orig := path + path = strings.TrimPrefix(path, req.URL.Scheme+"://"+host) + if !validPseudoPath(path) { + if req.URL.Opaque != "" { + return nil, fmt.Errorf("invalid request :path %q from URL.Opaque = %q", orig, req.URL.Opaque) + } else { + return nil, fmt.Errorf("invalid request :path %q", orig) + } + } + } + } + + // Check for any invalid headers and return an error before we + // potentially pollute our hpack state. (We want to be able to + // continue to reuse the hpack encoder for future requests) + for k, vv := range req.Header { + if !httpguts.ValidHeaderFieldName(k) { + return nil, fmt.Errorf("invalid HTTP header name %q", k) + } + for _, v := range vv { + if !httpguts.ValidHeaderFieldValue(v) { + // Don't include the value in the error, because it may be sensitive. + return nil, fmt.Errorf("invalid HTTP header value for header %q", k) + } + } + } + + enumerateHeaders := func(f func(name, value string)) { + // 8.1.2.3 Request Pseudo-Header Fields + // The :path pseudo-header field includes the path and query parts of the + // target URI (the path-absolute production and optionally a '?' character + // followed by the query production (see Sections 3.3 and 3.4 of + // [RFC3986]). + f(":authority", host) + m := req.Method + if m == "" { + m = http.MethodGet + } + f(":method", m) + if req.Method != "CONNECT" { + f(":path", path) + f(":scheme", req.URL.Scheme) + } + if trailers != "" { + f("trailer", trailers) + } + + var didUA bool + for k, vv := range req.Header { + if asciiEqualFold(k, "host") || asciiEqualFold(k, "content-length") { + // Host is :authority, already sent. + // Content-Length is automatic, set below. + continue + } else if asciiEqualFold(k, "connection") || + asciiEqualFold(k, "proxy-connection") || + asciiEqualFold(k, "transfer-encoding") || + asciiEqualFold(k, "upgrade") || + asciiEqualFold(k, "keep-alive") { + // Per 8.1.2.2 Connection-Specific Header + // Fields, don't send connection-specific + // fields. We have already checked if any + // are error-worthy so just ignore the rest. + continue + } else if asciiEqualFold(k, "user-agent") { + // Match Go's http1 behavior: at most one + // User-Agent. If set to nil or empty string, + // then omit it. Otherwise if not mentioned, + // include the default (below). + didUA = true + if len(vv) < 1 { + continue + } + vv = vv[:1] + if vv[0] == "" { + continue + } + } else if asciiEqualFold(k, "cookie") { + // Per 8.1.2.5 To allow for better compression efficiency, the + // Cookie header field MAY be split into separate header fields, + // each with one or more cookie-pairs. + for _, v := range vv { + for { + p := strings.IndexByte(v, ';') + if p < 0 { + break + } + f("cookie", v[:p]) + p++ + // strip space after semicolon if any. + for p+1 <= len(v) && v[p] == ' ' { + p++ + } + v = v[p:] + } + if len(v) > 0 { + f("cookie", v) + } + } + continue + } + + for _, v := range vv { + f(k, v) + } + } + if shouldSendReqContentLength(req.Method, contentLength) { + f("content-length", strconv.FormatInt(contentLength, 10)) + } + if addGzipHeader { + f("accept-encoding", "gzip") + } + if !didUA { + f("user-agent", defaultUserAgent) + } + } + + // Do a first pass over the headers counting bytes to ensure + // we don't exceed cc.peerMaxHeaderListSize. This is done as a + // separate pass before encoding the headers to prevent + // modifying the hpack state. + hlSize := uint64(0) + enumerateHeaders(func(name, value string) { + hf := hpack.HeaderField{Name: name, Value: value} + hlSize += uint64(hf.Size()) + }) + + if hlSize > cc.peerMaxHeaderListSize { + return nil, errRequestHeaderListSize + } + + trace := httptrace.ContextClientTrace(req.Context()) + traceHeaders := traceHasWroteHeaderField(trace) + + // Header list size is ok. Write the headers. + enumerateHeaders(func(name, value string) { + name, ascii := asciiToLower(name) + if !ascii { + // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header + // field names have to be ASCII characters (just as in HTTP/1.x). + return + } + cc.writeHeader(name, value) + if traceHeaders { + traceWroteHeaderField(trace, name, value) + } + }) + + return cc.hbuf.Bytes(), nil +} + +// shouldSendReqContentLength reports whether the http2.Transport should send +// a "content-length" request header. This logic is basically a copy of the net/http +// transferWriter.shouldSendContentLength. +// The contentLength is the corrected contentLength (so 0 means actually 0, not unknown). +// -1 means unknown. +func shouldSendReqContentLength(method string, contentLength int64) bool { + if contentLength > 0 { + return true + } + if contentLength < 0 { + return false + } + // For zero bodies, whether we send a content-length depends on the method. + // It also kinda doesn't matter for http2 either way, with END_STREAM. + switch method { + case "POST", "PUT", "PATCH": + return true + default: + return false + } +} + +// requires cc.wmu be held. +func (cc *ClientConn) encodeTrailers(trailer http.Header) ([]byte, error) { + cc.hbuf.Reset() + + hlSize := uint64(0) + for k, vv := range trailer { + for _, v := range vv { + hf := hpack.HeaderField{Name: k, Value: v} + hlSize += uint64(hf.Size()) + } + } + if hlSize > cc.peerMaxHeaderListSize { + return nil, errRequestHeaderListSize + } + + for k, vv := range trailer { + lowKey, ascii := asciiToLower(k) + if !ascii { + // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header + // field names have to be ASCII characters (just as in HTTP/1.x). + continue + } + // Transfer-Encoding, etc.. have already been filtered at the + // start of RoundTrip + for _, v := range vv { + cc.writeHeader(lowKey, v) + } + } + return cc.hbuf.Bytes(), nil +} + +func (cc *ClientConn) writeHeader(name, value string) { + if VerboseLogs { + log.Printf("http2: Transport encoding header %q = %q", name, value) + } + cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value}) +} + +type resAndError struct { + _ incomparable + res *http.Response + err error +} + +// requires cc.mu be held. +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 + if cs.ID == 0 { + panic("assigned stream ID 0") + } +} + +func (cc *ClientConn) forgetStreamID(id uint32) { + cc.mu.Lock() + 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.closeConn() + } + + cc.mu.Unlock() +} + +// clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop. +type clientConnReadLoop struct { + _ incomparable + cc *ClientConn +} + +// readLoop runs in its own goroutine and reads and dispatches frames. +func (cc *ClientConn) readLoop() { + rl := &clientConnReadLoop{cc: cc} + defer rl.cleanup() + cc.readerErr = rl.run() + if ce, ok := cc.readerErr.(ConnectionError); ok { + cc.wmu.Lock() + cc.fr.WriteGoAway(0, ErrCode(ce), nil) + cc.wmu.Unlock() + } +} + +// GoAwayError is returned by the Transport when the server closes the +// TCP connection after sending a GOAWAY frame. +type GoAwayError struct { + LastStreamID uint32 + ErrCode ErrCode + DebugData string +} + +func (e GoAwayError) Error() string { + return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q", + e.LastStreamID, e.ErrCode, e.DebugData) +} + +func isEOFOrNetReadError(err error) bool { + if err == io.EOF { + return true + } + ne, ok := err.(*net.OpError) + return ok && ne.Op == "read" +} + +func (rl *clientConnReadLoop) cleanup() { + cc := rl.cc + cc.t.connPool().MarkDead(cc) + defer cc.closeConn() + defer close(cc.readerDone) + + if cc.idleTimer != nil { + cc.idleTimer.Stop() + } + + // Close any response bodies if the server closes prematurely. + // TODO: also do this if we've written the headers but not + // gotten a response yet. + err := cc.readerErr + cc.mu.Lock() + if cc.goAway != nil && isEOFOrNetReadError(err) { + err = GoAwayError{ + LastStreamID: cc.goAway.LastStreamID, + ErrCode: cc.goAway.ErrCode, + DebugData: cc.goAwayDebug, + } + } else if err == io.EOF { + err = io.ErrUnexpectedEOF + } + cc.closed = true + for _, cs := range cc.streams { + select { + case <-cs.peerClosed: + // The server closed the stream before closing the conn, + // so no need to interrupt it. + default: + cs.abortStreamLocked(err) + } + } + 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 + gotSettings := false + readIdleTimeout := cc.t.ReadIdleTimeout + var t *time.Timer + if readIdleTimeout != 0 { + t = time.AfterFunc(readIdleTimeout, cc.healthCheck) + defer t.Stop() + } + for { + f, err := cc.fr.ReadFrame() + if t != nil { + t.Reset(readIdleTimeout) + } + if err != nil { + cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err) + } + if se, ok := err.(StreamError); ok { + if cs := rl.streamByID(se.StreamID); cs != nil { + if se.Cause == nil { + se.Cause = cc.fr.errDetail + } + rl.endStreamError(cs, se) + } + continue + } else if err != nil { + cc.countReadFrameError(err) + return err + } + if VerboseLogs { + cc.vlogf("http2: Transport received %s", summarizeFrame(f)) + } + if !gotSettings { + if _, ok := f.(*SettingsFrame); !ok { + cc.logf("protocol error: received %T before a SETTINGS frame", f) + return ConnectionError(ErrCodeProtocol) + } + gotSettings = true + } + + switch f := f.(type) { + case *MetaHeadersFrame: + err = rl.processHeaders(f) + case *DataFrame: + err = rl.processData(f) + case *GoAwayFrame: + err = rl.processGoAway(f) + case *RSTStreamFrame: + err = rl.processResetStream(f) + case *SettingsFrame: + err = rl.processSettings(f) + case *PushPromiseFrame: + err = rl.processPushPromise(f) + case *WindowUpdateFrame: + err = rl.processWindowUpdate(f) + case *PingFrame: + err = rl.processPing(f) + default: + cc.logf("Transport: unhandled response frame type %T", f) + } + if err != nil { + if VerboseLogs { + cc.vlogf("http2: Transport conn %p received error from processing frame %v: %v", cc, summarizeFrame(f), err) + } + return err + } + } +} + +func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error { + 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 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 { + // TODO(bradfitz): move first response byte earlier, + // when we first read the 9 byte header, not waiting + // until all the HEADERS+CONTINUATION frames have been + // merged. This works for now. + traceFirstResponseByte(cs.trace) + } + cs.firstByte = true + } + if !cs.pastHeaders { + cs.pastHeaders = true + } else { + return rl.processTrailers(cs, f) + } + + res, err := rl.handleResponse(cs, f) + if err != nil { + if _, ok := err.(ConnectionError); ok { + return err + } + // Any other error type is a stream error. + 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 { + // (nil, nil) special case. See handleResponse docs. + return nil + } + cs.resTrailer = &res.Trailer + cs.res = res + close(cs.respHeaderRecv) + if f.StreamEnded() { + rl.endStream(cs) + } + return nil +} + +// may return error types nil, or ConnectionError. Any other error value +// is a StreamError of type ErrCodeProtocol. The returned error in that case +// is the detail. +// +// As a special case, handleResponse may return (nil, nil) to skip the +// frame (currently only used for 1xx responses). +func (rl *clientConnReadLoop) handleResponse(cs *clientStream, f *MetaHeadersFrame) (*http.Response, error) { + if f.Truncated { + return nil, errResponseHeaderListSize + } + + status := f.PseudoValue("status") + if status == "" { + return nil, errors.New("malformed response from server: missing status pseudo header") + } + statusCode, err := strconv.Atoi(status) + if err != nil { + return nil, errors.New("malformed response from server: malformed non-numeric status pseudo header") + } + + regularFields := f.RegularFields() + strs := make([]string, len(regularFields)) + header := make(http.Header, len(regularFields)) + res := &http.Response{ + Proto: "HTTP/2.0", + ProtoMajor: 2, + Header: header, + StatusCode: statusCode, + Status: status + " " + http.StatusText(statusCode), + } + for _, hf := range regularFields { + key := http.CanonicalHeaderKey(hf.Name) + if key == "Trailer" { + t := res.Trailer + if t == nil { + t = make(http.Header) + res.Trailer = t + } + foreachHeaderElement(hf.Value, func(v string) { + t[http.CanonicalHeaderKey(v)] = nil + }) + } else { + vv := header[key] + if vv == nil && len(strs) > 0 { + // More than likely this will be a single-element key. + // Most headers aren't multi-valued. + // Set the capacity on strs[0] to 1, so any future append + // won't extend the slice into the other strings. + vv, strs = strs[:1:1], strs[1:] + vv[0] = hf.Value + header[key] = vv + } else { + header[key] = append(vv, hf.Value) + } + } + } + + 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 { + return nil, errors.New("http2: too many 1xx informational responses") + } + if fn := cs.get1xxTraceFunc(); fn != nil { + if err := fn(statusCode, textproto.MIMEHeader(header)); err != nil { + return nil, err + } + } + if statusCode == 100 { + traceGot100Continue(cs.trace) + select { + case cs.on100 <- struct{}{}: + default: + } + } + cs.pastHeaders = false // do it all again + return nil, nil + } + + 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 cs.isHead { + res.Body = noBody + return res, nil + } + + 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} + + if cs.requestedGzip && asciiEqualFold(res.Header.Get("Content-Encoding"), "gzip") { + res.Header.Del("Content-Encoding") + res.Header.Del("Content-Length") + res.ContentLength = -1 + res.Body = &gzipReader{body: res.Body} + res.Uncompressed = true + } + return res, nil +} + +func (rl *clientConnReadLoop) processTrailers(cs *clientStream, f *MetaHeadersFrame) error { + if cs.pastTrailers { + // Too many HEADERS frames for this stream. + return ConnectionError(ErrCodeProtocol) + } + cs.pastTrailers = true + if !f.StreamEnded() { + // We expect that any headers for trailers also + // has END_STREAM. + return ConnectionError(ErrCodeProtocol) + } + if len(f.PseudoFields()) > 0 { + // No pseudo header fields are defined for trailers. + // TODO: ConnectionError might be overly harsh? Check. + return ConnectionError(ErrCodeProtocol) + } + + trailer := make(http.Header) + for _, hf := range f.RegularFields() { + key := http.CanonicalHeaderKey(hf.Name) + trailer[key] = append(trailer[key], hf.Value) + } + cs.trailer = trailer + + rl.endStream(cs) + return nil +} + +// transportResponseBody is the concrete type of Transport.RoundTrip's +// Response.Body. It is an io.ReadCloser. +type transportResponseBody struct { + cs *clientStream +} + +func (b transportResponseBody) Read(p []byte) (n int, err error) { + cs := b.cs + cc := cs.cc + + if cs.readErr != nil { + return 0, cs.readErr + } + n, err = b.cs.bufPipe.Read(p) + if cs.bytesRemain != -1 { + if int64(n) > cs.bytesRemain { + n = int(cs.bytesRemain) + if err == nil { + err = errors.New("net/http: server replied with more than declared Content-Length; truncated") + cs.abortStream(err) + } + cs.readErr = err + return int(cs.bytesRemain), err + } + cs.bytesRemain -= int64(n) + if err == io.EOF && cs.bytesRemain > 0 { + err = io.ErrUnexpectedEOF + cs.readErr = err + return n, err + } + } + if n == 0 { + // No flow control tokens to send back. + return + } + + cc.mu.Lock() + var connAdd, streamAdd int32 + // Check the conn-level first, before the stream-level. + if v := cc.inflow.available(); v < transportDefaultConnFlow/2 { + connAdd = transportDefaultConnFlow - v + cc.inflow.add(connAdd) + } + if err == nil { // No need to refresh if the stream is over or failed. + // Consider any buffered body data (read from the conn but not + // consumed by the client) when computing flow control for this + // stream. + v := int(cs.inflow.available()) + cs.bufPipe.Len() + if v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh { + streamAdd = int32(transportDefaultStreamFlow - v) + cs.inflow.add(streamAdd) + } + } + cc.mu.Unlock() + + if connAdd != 0 || streamAdd != 0 { + cc.wmu.Lock() + defer cc.wmu.Unlock() + if connAdd != 0 { + cc.fr.WriteWindowUpdate(0, mustUint31(connAdd)) + } + if streamAdd != 0 { + cc.fr.WriteWindowUpdate(cs.ID, mustUint31(streamAdd)) + } + cc.bw.Flush() + } + return +} + +var errClosedResponseBody = errors.New("http2: response body closed") + +func (b transportResponseBody) Close() error { + cs := b.cs + cc := cs.cc + + unread := cs.bufPipe.Len() + if unread > 0 { + cc.mu.Lock() + // 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() + } + + cs.bufPipe.BreakWithError(errClosedResponseBody) + cs.abortStream(errClosedResponseBody) + + select { + case <-cs.donec: + case <-cs.ctx.Done(): + // See golang/go#49366: The net/http package can cancel the + // request context after the response body is fully read. + // Don't treat this as an error. + return nil + case <-cs.reqCancel: + return errRequestCanceled + } + return nil +} + +func (rl *clientConnReadLoop) processData(f *DataFrame) error { + cc := rl.cc + cs := rl.streamByID(f.StreamID) + data := f.Data() + if cs == nil { + cc.mu.Lock() + neverSent := cc.nextStreamID + cc.mu.Unlock() + if f.StreamID >= neverSent { + // We never asked for this. + cc.logf("http2: Transport received unsolicited DATA frame; closing connection") + return ConnectionError(ErrCodeProtocol) + } + // We probably did ask for this, but canceled. Just ignore it. + // TODO: be stricter here? only silently ignore things which + // we canceled, but not things which were closed normally + // by the peer? Tough without accumulating too much state. + + // But at least return their flow control: + if f.Length > 0 { + cc.mu.Lock() + cc.inflow.add(int32(f.Length)) + cc.mu.Unlock() + + cc.wmu.Lock() + cc.fr.WriteWindowUpdate(0, uint32(f.Length)) + cc.bw.Flush() + cc.wmu.Unlock() + } + 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{ + StreamID: f.StreamID, + Code: ErrCodeProtocol, + }) + return nil + } + if f.Length > 0 { + if cs.isHead && len(data) > 0 { + cc.logf("protocol error: received DATA on a HEAD request") + rl.endStreamError(cs, StreamError{ + StreamID: f.StreamID, + Code: ErrCodeProtocol, + }) + return nil + } + // Check connection-level flow control. + cc.mu.Lock() + if cs.inflow.available() >= int32(f.Length) { + cs.inflow.take(int32(f.Length)) + } else { + cc.mu.Unlock() + return ConnectionError(ErrCodeFlowControl) + } + // Return any padded flow control now, since we won't + // refund it later on body reads. + var refund int + if pad := int(f.Length) - len(data); pad > 0 { + refund += pad + } + + 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 { + cc.fr.WriteWindowUpdate(cs.ID, uint32(refund)) + } + cc.bw.Flush() + cc.wmu.Unlock() + } + + if err != nil { + rl.endStreamError(cs, err) + return nil + } + } + + if f.StreamEnded() { + rl.endStream(cs) + } + return nil +} + +func (rl *clientConnReadLoop) endStream(cs *clientStream) { + // TODO: check that any declared content-length matches, like + // server.go's (*stream).endStream method. + 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) { + cs.readAborted = true + cs.abortStream(err) +} + +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() { + for k, vv := range cs.trailer { + t := cs.resTrailer + if *t == nil { + *t = make(http.Header) + } + (*t)[k] = vv + } +} + +func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error { + cc := rl.cc + cc.t.connPool().MarkDead(cc) + 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 +} + +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() + + if f.IsAck() { + if cc.wantSettingsAck { + cc.wantSettingsAck = false + return nil + } + 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: + // Values above the maximum flow-control + // window size of 2^31-1 MUST be treated as a + // connection error (Section 5.4.1) of type + // FLOW_CONTROL_ERROR. + if s.Val > math.MaxInt32 { + return ConnectionError(ErrCodeFlowControl) + } + + // Adjust flow control of currently-open + // frames by the difference of the old initial + // window size and this one. + delta := int32(s.Val) - int32(cc.initialWindowSize) + for _, cs := range cc.streams { + cs.flow.add(delta) + } + cc.cond.Broadcast() + + cc.initialWindowSize = s.Val + default: + // TODO(bradfitz): handle more settings? SETTINGS_HEADER_TABLE_SIZE probably. + cc.vlogf("Unhandled Setting: %v", s) + } + return nil + }) + if err != nil { + return err + } + + 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 + } + + return nil +} + +func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error { + cc := rl.cc + cs := rl.streamByID(f.StreamID) + if f.StreamID != 0 && cs == nil { + return nil + } + + cc.mu.Lock() + defer cc.mu.Unlock() + + fl := &cc.flow + if cs != nil { + fl = &cs.flow + } + if !fl.add(int32(f.Increment)) { + return ConnectionError(ErrCodeFlowControl) + } + cc.cond.Broadcast() + return nil +} + +func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error { + cs := rl.streamByID(f.StreamID) + if cs == nil { + // TODO: return error if server tries to RST_STREAM an idle stream + return nil + } + 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 +} + +// Ping sends a PING frame to the server and waits for the ack. +func (cc *ClientConn) Ping(ctx context.Context) error { + c := make(chan struct{}) + // Generate a random payload + var p [8]byte + for { + if _, err := rand.Read(p[:]); err != nil { + return err + } + cc.mu.Lock() + // check for dup before insert + if _, found := cc.pings[p]; !found { + cc.pings[p] = c + cc.mu.Unlock() + break + } + cc.mu.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: + // connection closed + return cc.readerErr + } +} + +func (rl *clientConnReadLoop) processPing(f *PingFrame) error { + if f.IsAck() { + cc := rl.cc + cc.mu.Lock() + defer cc.mu.Unlock() + // If ack, notify listener if any + if c, ok := cc.pings[f.Data]; ok { + close(c) + delete(cc.pings, f.Data) + } + return nil + } + cc := rl.cc + cc.wmu.Lock() + defer cc.wmu.Unlock() + if err := cc.fr.WritePing(true, f.Data); err != nil { + return err + } + return cc.bw.Flush() +} + +func (rl *clientConnReadLoop) processPushPromise(f *PushPromiseFrame) error { + // We told the peer we don't want them. + // Spec says: + // "PUSH_PROMISE MUST NOT be sent if the SETTINGS_ENABLE_PUSH + // setting of the peer endpoint is set to 0. An endpoint that + // has set this setting and has received acknowledgement MUST + // treat the receipt of a PUSH_PROMISE frame as a connection + // error (Section 5.4.1) of type PROTOCOL_ERROR." + return ConnectionError(ErrCodeProtocol) +} + +func (cc *ClientConn) writeStreamReset(streamID uint32, code ErrCode, err error) { + // TODO: map err to more interesting error codes, once the + // HTTP community comes up with some. But currently for + // RST_STREAM there's no equivalent to GOAWAY frame's debug + // data, and the error codes are all pretty vague ("cancel"). + cc.wmu.Lock() + cc.fr.WriteRSTStream(streamID, code) + cc.bw.Flush() + cc.wmu.Unlock() +} + +var ( + errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit") + errRequestHeaderListSize = errors.New("http2: request header list larger than peer's advertised limit") +) + +func (cc *ClientConn) logf(format string, args ...interface{}) { + cc.t.logf(format, args...) +} + +func (cc *ClientConn) vlogf(format string, args ...interface{}) { + cc.t.vlogf(format, args...) +} + +func (t *Transport) vlogf(format string, args ...interface{}) { + if VerboseLogs { + t.logf(format, args...) + } +} + +func (t *Transport) logf(format string, args ...interface{}) { + log.Printf(format, args...) +} + +var noBody io.ReadCloser = noBodyReader{} + +type noBodyReader struct{} + +func (noBodyReader) Close() error { return nil } +func (noBodyReader) Read([]byte) (int, error) { return 0, io.EOF } + +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 { + return true + } + } + return false +} + +type erringRoundTripper struct{ err error } + +func (rt erringRoundTripper) RoundTripErr() error { return rt.err } +func (rt erringRoundTripper) RoundTrip(*http.Request) (*http.Response, error) { return nil, rt.err } + +// gzipReader wraps a response body so it can lazily +// call gzip.NewReader on the first call to Read +type gzipReader struct { + _ incomparable + body io.ReadCloser // underlying Response.Body + zr *gzip.Reader // lazily-initialized gzip reader + zerr error // sticky error +} + +func (gz *gzipReader) Read(p []byte) (n int, err error) { + if gz.zerr != nil { + return 0, gz.zerr + } + if gz.zr == nil { + gz.zr, err = gzip.NewReader(gz.body) + if err != nil { + gz.zerr = err + return 0, err + } + } + return gz.zr.Read(p) +} + +func (gz *gzipReader) Close() error { + return gz.body.Close() +} + +type errorReader struct{ err error } + +func (r errorReader) Read(p []byte) (int, error) { return 0, r.err } + +// isConnectionCloseRequest reports whether req should use its own +// connection for a single request and then close the connection. +func isConnectionCloseRequest(req *http.Request) bool { + return req.Close || httpguts.HeaderValuesContainsToken(req.Header["Connection"], "close") +} + +// registerHTTPSProtocol calls Transport.RegisterProtocol but +// converting panics into errors. +func registerHTTPSProtocol(t *http.Transport, rt noDialH2RoundTripper) (err error) { + defer func() { + if e := recover(); e != nil { + err = fmt.Errorf("%v", e) + } + }() + t.RegisterProtocol("https", rt) + return nil +} + +// noDialH2RoundTripper is a RoundTripper which only tries to complete the request +// if there's already has a cached connection to the host. +// (The field is exported so it can be accessed via reflect from net/http; tested +// by TestNoDialH2RoundTripperType) +type noDialH2RoundTripper struct{ *Transport } + +func (rt noDialH2RoundTripper) RoundTrip(req *http.Request) (*http.Response, error) { + res, err := rt.Transport.RoundTrip(req) + if isNoCachedConnError(err) { + return nil, http.ErrSkipAltProtocol + } + return res, err +} + +func (t *Transport) idleConnTimeout() time.Duration { + if t.t1 != nil { + return t.t1.IdleConnTimeout + } + return 0 +} + +func traceGetConn(req *http.Request, hostPort string) { + trace := httptrace.ContextClientTrace(req.Context()) + if trace == nil || trace.GetConn == nil { + return + } + trace.GetConn(hostPort) +} + +func traceGotConn(req *http.Request, cc *ClientConn, reused bool) { + trace := httptrace.ContextClientTrace(req.Context()) + if trace == nil || trace.GotConn == nil { + return + } + ci := httptrace.GotConnInfo{Conn: cc.tconn} + ci.Reused = reused + cc.mu.Lock() + ci.WasIdle = len(cc.streams) == 0 && reused + if ci.WasIdle && !cc.lastActive.IsZero() { + ci.IdleTime = time.Now().Sub(cc.lastActive) + } + cc.mu.Unlock() + + trace.GotConn(ci) +} + +func traceWroteHeaders(trace *httptrace.ClientTrace) { + if trace != nil && trace.WroteHeaders != nil { + trace.WroteHeaders() + } +} + +func traceGot100Continue(trace *httptrace.ClientTrace) { + if trace != nil && trace.Got100Continue != nil { + trace.Got100Continue() + } +} + +func traceWait100Continue(trace *httptrace.ClientTrace) { + if trace != nil && trace.Wait100Continue != nil { + trace.Wait100Continue() + } +} + +func traceWroteRequest(trace *httptrace.ClientTrace, err error) { + if trace != nil && trace.WroteRequest != nil { + trace.WroteRequest(httptrace.WroteRequestInfo{Err: err}) + } +} + +func traceFirstResponseByte(trace *httptrace.ClientTrace) { + if trace != nil && trace.GotFirstResponseByte != nil { + trace.GotFirstResponseByte() + } +} |