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// 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"
"io/ioutil"
"log"
"math"
mathrand "math/rand"
"net"
"net/http"
"net/http/httptrace"
"net/textproto"
"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"
)
// 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 {
// DialTLS specifies an optional dial function for creating
// TLS connections for requests.
//
// If 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.
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 ulimited 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
// 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)
}
// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
// It returns an error if t1 has already been HTTP/2-enabled.
func ConfigureTransport(t1 *http.Transport) error {
_, err := configureTransport(t1)
return err
}
func configureTransport(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
// 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
closing bool
closed bool
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
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
// Settings from peer: (also guarded by mu)
maxFrameSize uint32
maxConcurrentStreams uint32
peerMaxHeaderListSize uint64
initialWindowSize uint32
hbuf bytes.Buffer // HPACK encoder writes into this
henc *hpack.Encoder
freeBuf [][]byte
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
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
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
done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu
// 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
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,
// 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)
}
// 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) 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)
}
}
// 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
}
}
func (cs *clientStream) getStartedWrite() bool {
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()
cs.stopReqBody = err
cc.cond.Broadcast()
cc.mu.Unlock()
}
type stickyErrWriter struct {
w io.Writer
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
}
// 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, gotErrAfterReqBodyWrite, err := cc.roundTrip(req)
if err != nil && retry <= 6 {
if req, err = shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil {
// After the first retry, do exponential backoff with 10% jitter.
if retry == 0 {
continue
}
backoff := float64(uint(1) << (uint(retry) - 1))
backoff += backoff * (0.1 * mathrand.Float64())
select {
case <-time.After(time.Second * time.Duration(backoff)):
continue
case <-req.Context().Done():
return nil, 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, afterBodyWrite bool) (*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 {
// TODO: consider a req.Body.Close here? or audit that all caller paths do?
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. The "afterBodyWrite" means the
// bodyWrite process has started, which becomes true before
// the first Read.
if !afterBodyWrite {
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 {
return se.Code == ErrCodeRefusedStream
}
return false
}
func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
host, _, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
tconn, err := t.dialTLS()("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() func(string, string, *tls.Config) (net.Conn, error) {
if t.DialTLS != nil {
return t.DialTLS
}
return t.dialTLSDefault
}
func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) {
cn, err := tls.Dial(network, addr, cfg)
if err != nil {
return nil, err
}
if err := cn.Handshake(); err != nil {
return nil, err
}
if !cfg.InsecureSkipVerify {
if err := cn.VerifyHostname(cfg.ServerName); err != nil {
return nil, err
}
}
state := cn.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 cn, 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, false)
}
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: 1000, // "infinite", per spec. 1000 seems good enough.
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{}),
}
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{c, &cc.werr})
cc.br = bufio.NewReader(c)
cc.fr = NewFramer(cc.bw, cc.br)
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 {
return nil, cc.werr
}
go cc.readLoop()
return cc, nil
}
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 {
select {
case cs.resc <- resAndError{err: errClientConnGotGoAway}:
default:
}
}
}
}
// CanTakeNewRequest reports whether the connection can take a new request,
// meaning it has not been closed or received or sent a GOAWAY.
func (cc *ClientConn) CanTakeNewRequest() bool {
cc.mu.Lock()
defer cc.mu.Unlock()
return cc.canTakeNewRequestLocked()
}
// 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 {
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)+1) < int64(cc.maxConcurrentStreams)
}
st.canTakeNewRequest = cc.goAway == nil && !cc.closed && !cc.closing && maxConcurrentOkay &&
int64(cc.nextStreamID)+2*int64(cc.pendingRequests) < math.MaxInt32
st.freshConn = cc.nextStreamID == 1 && st.canTakeNewRequest
return
}
func (cc *ClientConn) canTakeNewRequestLocked() bool {
st := cc.idleStateLocked()
return st.canTakeNewRequest
}
// 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) closeIfIdle() {
cc.mu.Lock()
if len(cc.streams) > 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.tconn.Close()
}
var shutdownEnterWaitStateHook = func() {}
// Shutdown gracefully close 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 error, 1)
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
done <- cc.tconn.Close()
break
}
if cancelled {
break
}
cc.cond.Wait()
}
}()
shutdownEnterWaitStateHook()
select {
case err := <-done:
return err
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()
defer cc.mu.Unlock()
cc.wmu.Lock()
defer cc.wmu.Unlock()
if cc.closing {
// GOAWAY sent already
return nil
}
// Send a graceful shutdown frame to server
maxStreamID := cc.nextStreamID
if err := cc.fr.WriteGoAway(maxStreamID, ErrCodeNo, nil); err != nil {
return err
}
if err := cc.bw.Flush(); err != nil {
return err
}
// Prevent new requests
cc.closing = true
return nil
}
// Close closes the client connection immediately.
//
// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead.
func (cc *ClientConn) Close() error {
cc.mu.Lock()
defer cc.cond.Broadcast()
defer cc.mu.Unlock()
err := errors.New("http2: client connection force closed via ClientConn.Close")
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()
}
const maxAllocFrameSize = 512 << 10
// frameBuffer returns a scratch buffer suitable for writing DATA frames.
// They're capped at the min of the peer's max frame size or 512KB
// (kinda arbitrarily), but definitely capped so we don't allocate 4GB
// bufers.
func (cc *ClientConn) frameScratchBuffer() []byte {
cc.mu.Lock()
size := cc.maxFrameSize
if size > maxAllocFrameSize {
size = maxAllocFrameSize
}
for i, buf := range cc.freeBuf {
if len(buf) >= int(size) {
cc.freeBuf[i] = nil
cc.mu.Unlock()
return buf[:size]
}
}
cc.mu.Unlock()
return make([]byte, size)
}
func (cc *ClientConn) putFrameScratchBuffer(buf []byte) {
cc.mu.Lock()
defer cc.mu.Unlock()
const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
if len(cc.freeBuf) < maxBufs {
cc.freeBuf = append(cc.freeBuf, buf)
return
}
for i, old := range cc.freeBuf {
if old == nil {
cc.freeBuf[i] = buf
return
}
}
// forget about it.
}
// 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 "", &badStringError{"invalid Trailer key", 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] != "" && !strings.EqualFold(vv[0], "close") && !strings.EqualFold(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) RoundTrip(req *http.Request) (*http.Response, error) {
resp, _, err := cc.roundTrip(req)
return resp, err
}
func (cc *ClientConn) roundTrip(req *http.Request) (res *http.Response, gotErrAfterReqBodyWrite bool, err error) {
if err := checkConnHeaders(req); err != nil {
return nil, false, err
}
if cc.idleTimer != nil {
cc.idleTimer.Stop()
}
trailers, err := commaSeparatedTrailers(req)
if err != nil {
return nil, false, err
}
hasTrailers := trailers != ""
cc.mu.Lock()
if err := cc.awaitOpenSlotForRequest(req); err != nil {
cc.mu.Unlock()
return nil, false, err
}
body := req.Body
contentLen := actualContentLength(req)
hasBody := contentLen != 0
// 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" {
// Request gzip only, not deflate. Deflate is ambiguous and
// not as universally supported anyway.
// See: http://www.gzip.org/zlib/zlib_faq.html#faq38
//
// 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
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)
if err != nil {
cc.mu.Unlock()
return nil, false, 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
cc.wmu.Lock()
endStream := !hasBody && !hasTrailers
werr := cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs)
cc.wmu.Unlock()
traceWroteHeaders(cs.trace)
cc.mu.Unlock()
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
}
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
}
}
readLoopResCh := cs.resc
bodyWritten := false
ctx := req.Context()
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 re.err != nil {
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), re.err
}
res.Request = req
res.TLS = cc.tlsState
return res, false, nil
}
for {
select {
case re := <-readLoopResCh:
return handleReadLoopResponse(re)
case <-respHeaderTimer:
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), errTimeout
case <-ctx.Done():
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), ctx.Err()
case <-req.Cancel:
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), 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:
// 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
}
bodyWritten = true
if d := cc.responseHeaderTimeout(); d != 0 {
timer := time.NewTimer(d)
defer timer.Stop()
respHeaderTimer = timer.C
}
}
}
}
// awaitOpenSlotForRequest 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
for {
cc.lastActive = time.Now()
if cc.closed || !cc.canTakeNewRequestLocked() {
if waitingForConn != nil {
close(waitingForConn)
}
return errClientConnUnusable
}
if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) {
if waitingForConn != nil {
close(waitingForConn)
}
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
}
}
}
// 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)
}
}
// 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
}
// 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")
)
func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) {
cc := cs.cc
sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
buf := cc.frameScratchBuffer()
defer cc.putFrameScratchBuffer(buf)
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
cerr := bodyCloser.Close()
if err == nil {
err = cerr
}
}()
req := cs.req
hasTrailers := req.Trailer != nil
var sawEOF bool
for !sawEOF {
n, err := body.Read(buf)
if err == io.EOF {
sawEOF = true
err = nil
} else if err != nil {
cc.writeStreamReset(cs.ID, ErrCodeCancel, err)
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:
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
}
var trls []byte
if hasTrailers {
cc.mu.Lock()
trls, err = cc.encodeTrailers(req)
cc.mu.Unlock()
if err != nil {
cc.writeStreamReset(cs.ID, ErrCodeInternal, err)
cc.forgetStreamID(cs.ID)
return err
}
}
cc.mu.Lock()
maxFrameSize := int(cc.maxFrameSize)
cc.mu.Unlock()
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 {
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
cc.mu.Lock()
defer cc.mu.Unlock()
for {
if cc.closed {
return 0, errClientConnClosed
}
if cs.stopReqBody != nil {
return 0, cs.stopReqBody
}
if err := cs.checkResetOrDone(); err != nil {
return 0, err
}
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()
}
}
type badStringError struct {
what string
str string
}
func (e *badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) }
// requires cc.mu be held.
func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) {
cc.hbuf.Reset()
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) {
return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, 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 strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
// Host is :authority, already sent.
// Content-Length is automatic, set below.
continue
} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
strings.EqualFold(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 strings.EqualFold(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
}
}
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 = strings.ToLower(name)
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.mu be held.
func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) {
cc.hbuf.Reset()
hlSize := uint64(0)
for k, vv := range req.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 req.Trailer {
// Transfer-Encoding, etc.. have already been filtered at the
// start of RoundTrip
lowKey := strings.ToLower(k)
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 {
res *http.Response
err error
}
// 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{}),
}
cs.flow.add(int32(cc.initialWindowSize))
cs.flow.setConnFlow(&cc.flow)
cs.inflow.add(transportDefaultStreamFlow)
cs.inflow.setConnFlow(&cc.inflow)
cc.nextStreamID += 2
cc.streams[cs.ID] = cs
return cs
}
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)
}
close(cs.done)
// Wake up checkResetOrDone via clientStream.awaitFlowControl and
// wake up RoundTrip if there is a pending request.
cc.cond.Broadcast()
}
return cs
}
// clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
type clientConnReadLoop struct {
cc *ClientConn
closeWhenIdle bool
}
// 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
defer cc.tconn.Close()
defer cc.t.connPool().MarkDead(cc)
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
}
for _, cs := range cc.streams {
cs.bufPipe.CloseWithError(err) // no-op if already closed
select {
case cs.resc <- resAndError{err: err}:
default:
}
close(cs.done)
}
cc.closed = true
cc.cond.Broadcast()
cc.mu.Unlock()
}
func (rl *clientConnReadLoop) run() error {
cc := rl.cc
rl.closeWhenIdle = cc.t.disableKeepAlives() || cc.singleUse
gotReply := false // ever saw a HEADERS reply
gotSettings := false
for {
f, err := cc.fr.ReadFrame()
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 := cc.streamByID(se.StreamID, false); cs != nil {
cs.cc.writeStreamReset(cs.ID, se.Code, err)
cs.cc.forgetStreamID(cs.ID)
if se.Cause == nil {
se.Cause = cc.fr.errDetail
}
rl.endStreamError(cs, se)
}
continue
} else if err != nil {
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
}
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:
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
}
if rl.closeWhenIdle && gotReply && maybeIdle {
cc.closeIfIdle()
}
}
}
func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, false)
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.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.
cs.cc.writeStreamReset(f.StreamID, ErrCodeProtocol, err)
cc.forgetStreamID(cs.ID)
cs.resc <- resAndError{err: 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.resc <- resAndError{res: res}
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")
}
header := make(http.Header)
res := &http.Response{
Proto: "HTTP/2.0",
ProtoMajor: 2,
Header: header,
StatusCode: statusCode,
Status: status + " " + http.StatusText(statusCode),
}
for _, hf := range f.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 {
header[key] = append(header[key], hf.Value)
}
}
if statusCode >= 100 && statusCode <= 199 {
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)
if cs.on100 != nil {
cs.on100() // forces any write delay timer to fire
}
}
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 clen64, err := strconv.ParseInt(clens[0], 10, 64); err == nil {
res.ContentLength = clen64
} 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.
}
}
if streamEnded || isHead {
res.Body = noBody
return res, nil
}
cs.bufPipe = pipe{b: &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")
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. On Read, it reads from cs.body.
// On Close it sends RST_STREAM if EOF wasn't already seen.
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")
cc.writeStreamReset(cs.ID, ErrCodeProtocol, 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()
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 {
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)
}
}
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
serverSentStreamEnd := cs.bufPipe.Err() == io.EOF
unread := cs.bufPipe.Len()
if unread > 0 || !serverSentStreamEnd {
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.fr.WriteWindowUpdate(0, uint32(unread))
}
cc.bw.Flush()
cc.wmu.Unlock()
cc.mu.Unlock()
}
cs.bufPipe.BreakWithError(errClosedResponseBody)
cc.forgetStreamID(cs.ID)
return nil
}
func (rl *clientConnReadLoop) processData(f *DataFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, f.StreamEnded())
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.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.req.Method == "HEAD" && 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
}
// Return len(data) now if the stream is already closed,
// since data will never be read.
didReset := cs.didReset
if didReset {
refund += len(data)
}
if refund > 0 {
cc.inflow.add(int32(refund))
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 f.StreamEnded() {
rl.endStream(cs)
}
return nil
}
var errInvalidTrailers = errors.New("http2: invalid trailers")
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)
}
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)
select {
case cs.resc <- resAndError{err: err}:
default:
}
}
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)
}
cc.setGoAway(f)
return nil
}
func (rl *clientConnReadLoop) processSettings(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)
}
err := f.ForeachSetting(func(s Setting) error {
switch s.ID {
case SettingMaxFrameSize:
cc.maxFrameSize = s.Val
case SettingMaxConcurrentStreams:
cc.maxConcurrentStreams = s.Val
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
}
cc.wmu.Lock()
defer cc.wmu.Unlock()
cc.fr.WriteSettingsAck()
cc.bw.Flush()
return cc.werr
}
func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, false)
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.cc.streamByID(f.StreamID, true)
if cs == nil {
// TODO: return error if server tries to RST_STEAM 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
}
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()
}
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()
select {
case <-c:
return nil
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")
errPseudoTrailers = errors.New("http2: invalid pseudo header in trailers")
)
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 = ioutil.NopCloser(bytes.NewReader(nil))
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) 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 {
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 }
// 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 {
s.timer.Stop()
}
}
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 {
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()
}
}
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