/*
*
* Copyright 2014 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package transport
import (
"io"
"math"
"net"
"strings"
"sync"
"sync/atomic"
"time"
"golang.org/x/net/context"
"golang.org/x/net/http2"
"golang.org/x/net/http2/hpack"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/internal/channelz"
"google.golang.org/grpc/keepalive"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/peer"
"google.golang.org/grpc/stats"
"google.golang.org/grpc/status"
)
// http2Client implements the ClientTransport interface with HTTP2.
type http2Client struct {
ctx context.Context
cancel context.CancelFunc
ctxDone <-chan struct{} // Cache the ctx.Done() chan.
userAgent string
md interface{}
conn net.Conn // underlying communication channel
loopy *loopyWriter
remoteAddr net.Addr
localAddr net.Addr
authInfo credentials.AuthInfo // auth info about the connection
readerDone chan struct{} // sync point to enable testing.
writerDone chan struct{} // sync point to enable testing.
// goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor)
// that the server sent GoAway on this transport.
goAway chan struct{}
// awakenKeepalive is used to wake up keepalive when after it has gone dormant.
awakenKeepalive chan struct{}
framer *framer
// controlBuf delivers all the control related tasks (e.g., window
// updates, reset streams, and various settings) to the controller.
controlBuf *controlBuffer
fc *trInFlow
// The scheme used: https if TLS is on, http otherwise.
scheme string
isSecure bool
creds []credentials.PerRPCCredentials
// Boolean to keep track of reading activity on transport.
// 1 is true and 0 is false.
activity uint32 // Accessed atomically.
kp keepalive.ClientParameters
keepaliveEnabled bool
statsHandler stats.Handler
initialWindowSize int32
bdpEst *bdpEstimator
// onSuccess is a callback that client transport calls upon
// receiving server preface to signal that a succefull HTTP2
// connection was established.
onSuccess func()
maxConcurrentStreams uint32
streamQuota int64
streamsQuotaAvailable chan struct{}
waitingStreams uint32
nextID uint32
mu sync.Mutex // guard the following variables
state transportState
activeStreams map[uint32]*Stream
// prevGoAway ID records the Last-Stream-ID in the previous GOAway frame.
prevGoAwayID uint32
// goAwayReason records the http2.ErrCode and debug data received with the
// GoAway frame.
goAwayReason GoAwayReason
// Fields below are for channelz metric collection.
channelzID int64 // channelz unique identification number
czmu sync.RWMutex
kpCount int64
// The number of streams that have started, including already finished ones.
streamsStarted int64
// The number of streams that have ended successfully by receiving EoS bit set
// frame from server.
streamsSucceeded int64
streamsFailed int64
lastStreamCreated time.Time
msgSent int64
msgRecv int64
lastMsgSent time.Time
lastMsgRecv time.Time
}
func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) {
if fn != nil {
return fn(ctx, addr)
}
return dialContext(ctx, "tcp", addr)
}
func isTemporary(err error) bool {
switch err := err.(type) {
case interface {
Temporary() bool
}:
return err.Temporary()
case interface {
Timeout() bool
}:
// Timeouts may be resolved upon retry, and are thus treated as
// temporary.
return err.Timeout()
}
return true
}
// newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
// and starts to receive messages on it. Non-nil error returns if construction
// fails.
func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts ConnectOptions, onSuccess func()) (_ ClientTransport, err error) {
scheme := "http"
ctx, cancel := context.WithCancel(ctx)
defer func() {
if err != nil {
cancel()
}
}()
conn, err := dial(connectCtx, opts.Dialer, addr.Addr)
if err != nil {
if opts.FailOnNonTempDialError {
return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
}
return nil, connectionErrorf(true, err, "transport: Error while dialing %v", err)
}
// Any further errors will close the underlying connection
defer func(conn net.Conn) {
if err != nil {
conn.Close()
}
}(conn)
var (
isSecure bool
authInfo credentials.AuthInfo
)
if creds := opts.TransportCredentials; creds != nil {
scheme = "https"
conn, authInfo, err = creds.ClientHandshake(connectCtx, addr.Authority, conn)
if err != nil {
return nil, connectionErrorf(isTemporary(err), err, "transport: authentication handshake failed: %v", err)
}
isSecure = true
}
kp := opts.KeepaliveParams
// Validate keepalive parameters.
if kp.Time == 0 {
kp.Time = defaultClientKeepaliveTime
}
if kp.Timeout == 0 {
kp.Timeout = defaultClientKeepaliveTimeout
}
dynamicWindow := true
icwz := int32(initialWindowSize)
if opts.InitialConnWindowSize >= defaultWindowSize {
icwz = opts.InitialConnWindowSize
dynamicWindow = false
}
writeBufSize := defaultWriteBufSize
if opts.WriteBufferSize > 0 {
writeBufSize = opts.WriteBufferSize
}
readBufSize := defaultReadBufSize
if opts.ReadBufferSize > 0 {
readBufSize = opts.ReadBufferSize
}
t := &http2Client{
ctx: ctx,
ctxDone: ctx.Done(), // Cache Done chan.
cancel: cancel,
userAgent: opts.UserAgent,
md: addr.Metadata,
conn: conn,
remoteAddr: conn.RemoteAddr(),
localAddr: conn.LocalAddr(),
authInfo: authInfo,
readerDone: make(chan struct{}),
writerDone: make(chan struct{}),
goAway: make(chan struct{}),
awakenKeepalive: make(chan struct{}, 1),
framer: newFramer(conn, writeBufSize, readBufSize),
fc: &trInFlow{limit: uint32(icwz)},
scheme: scheme,
activeStreams: make(map[uint32]*Stream),
isSecure: isSecure,
creds: opts.PerRPCCredentials,
kp: kp,
statsHandler: opts.StatsHandler,
initialWindowSize: initialWindowSize,
onSuccess: onSuccess,
nextID: 1,
maxConcurrentStreams: defaultMaxStreamsClient,
streamQuota: defaultMaxStreamsClient,
streamsQuotaAvailable: make(chan struct{}, 1),
}
t.controlBuf = newControlBuffer(t.ctxDone)
if opts.InitialWindowSize >= defaultWindowSize {
t.initialWindowSize = opts.InitialWindowSize
dynamicWindow = false
}
if dynamicWindow {
t.bdpEst = &bdpEstimator{
bdp: initialWindowSize,
updateFlowControl: t.updateFlowControl,
}
}
// Make sure awakenKeepalive can't be written upon.
// keepalive routine will make it writable, if need be.
t.awakenKeepalive <- struct{}{}
if t.statsHandler != nil {
t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{
RemoteAddr: t.remoteAddr,
LocalAddr: t.localAddr,
})
connBegin := &stats.ConnBegin{
Client: true,
}
t.statsHandler.HandleConn(t.ctx, connBegin)
}
if channelz.IsOn() {
t.channelzID = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, "")
}
if t.kp.Time != infinity {
t.keepaliveEnabled = true
go t.keepalive()
}
// Start the reader goroutine for incoming message. Each transport has
// a dedicated goroutine which reads HTTP2 frame from network. Then it
// dispatches the frame to the corresponding stream entity.
go t.reader()
// Send connection preface to server.
n, err := t.conn.Write(clientPreface)
if err != nil {
t.Close()
return nil, connectionErrorf(true, err, "transport: failed to write client preface: %v", err)
}
if n != len(clientPreface) {
t.Close()
return nil, connectionErrorf(true, err, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
}
if t.initialWindowSize != defaultWindowSize {
err = t.framer.fr.WriteSettings(http2.Setting{
ID: http2.SettingInitialWindowSize,
Val: uint32(t.initialWindowSize),
})
} else {
err = t.framer.fr.WriteSettings()
}
if err != nil {
t.Close()
return nil, connectionErrorf(true, err, "transport: failed to write initial settings frame: %v", err)
}
// Adjust the connection flow control window if needed.
if delta := uint32(icwz - defaultWindowSize); delta > 0 {
if err := t.framer.fr.WriteWindowUpdate(0, delta); err != nil {
t.Close()
return nil, connectionErrorf(true, err, "transport: failed to write window update: %v", err)
}
}
t.framer.writer.Flush()
go func() {
t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst)
err := t.loopy.run()
if err != nil {
errorf("transport: loopyWriter.run returning. Err: %v", err)
}
// If it's a connection error, let reader goroutine handle it
// since there might be data in the buffers.
if _, ok := err.(net.Error); !ok {
t.conn.Close()
}
close(t.writerDone)
}()
return t, nil
}
func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
// TODO(zhaoq): Handle uint32 overflow of Stream.id.
s := &Stream{
done: make(chan struct{}),
method: callHdr.Method,
sendCompress: callHdr.SendCompress,
buf: newRecvBuffer(),
headerChan: make(chan struct{}),
contentSubtype: callHdr.ContentSubtype,
}
s.wq = newWriteQuota(defaultWriteQuota, s.done)
s.requestRead = func(n int) {
t.adjustWindow(s, uint32(n))
}
// The client side stream context should have exactly the same life cycle with the user provided context.
// That means, s.ctx should be read-only. And s.ctx is done iff ctx is done.
// So we use the original context here instead of creating a copy.
s.ctx = ctx
s.trReader = &transportReader{
reader: &recvBufferReader{
ctx: s.ctx,
ctxDone: s.ctx.Done(),
recv: s.buf,
},
windowHandler: func(n int) {
t.updateWindow(s, uint32(n))
},
}
return s
}
func (t *http2Client) getPeer() *peer.Peer {
pr := &peer.Peer{
Addr: t.remoteAddr,
}
// Attach Auth info if there is any.
if t.authInfo != nil {
pr.AuthInfo = t.authInfo
}
return pr
}
func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr) ([]hpack.HeaderField, error) {
aud := t.createAudience(callHdr)
authData, err := t.getTrAuthData(ctx, aud)
if err != nil {
return nil, err
}
callAuthData, err := t.getCallAuthData(ctx, aud, callHdr)
if err != nil {
return nil, err
}
// TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
// first and create a slice of that exact size.
// Make the slice of certain predictable size to reduce allocations made by append.
hfLen := 7 // :method, :scheme, :path, :authority, content-type, user-agent, te
hfLen += len(authData) + len(callAuthData)
headerFields := make([]hpack.HeaderField, 0, hfLen)
headerFields = append(headerFields, hpack.HeaderField{Name: ":method", Value: "POST"})
headerFields = append(headerFields, hpack.HeaderField{Name: ":scheme", Value: t.scheme})
headerFields = append(headerFields, hpack.HeaderField{Name: ":path", Value: callHdr.Method})
headerFields = append(headerFields, hpack.HeaderField{Name: ":authority", Value: callHdr.Host})
headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: contentType(callHdr.ContentSubtype)})
headerFields = append(headerFields, hpack.HeaderField{Name: "user-agent", Value: t.userAgent})
headerFields = append(headerFields, hpack.HeaderField{Name: "te", Value: "trailers"})
if callHdr.SendCompress != "" {
headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress})
}
if dl, ok := ctx.Deadline(); ok {
// Send out timeout regardless its value. The server can detect timeout context by itself.
// TODO(mmukhi): Perhaps this field should be updated when actually writing out to the wire.
timeout := dl.Sub(time.Now())
headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-timeout", Value: encodeTimeout(timeout)})
}
for k, v := range authData {
headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
}
for k, v := range callAuthData {
headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
}
if b := stats.OutgoingTags(ctx); b != nil {
headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-tags-bin", Value: encodeBinHeader(b)})
}
if b := stats.OutgoingTrace(ctx); b != nil {
headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-trace-bin", Value: encodeBinHeader(b)})
}
if md, added, ok := metadata.FromOutgoingContextRaw(ctx); ok {
var k string
for _, vv := range added {
for i, v := range vv {
if i%2 == 0 {
k = v
continue
}
// HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
if isReservedHeader(k) {
continue
}
headerFields = append(headerFields, hpack.HeaderField{Name: strings.ToLower(k), Value: encodeMetadataHeader(k, v)})
}
}
for k, vv := range md {
// HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
if isReservedHeader(k) {
continue
}
for _, v := range vv {
headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
}
}
}
if md, ok := t.md.(*metadata.MD); ok {
for k, vv := range *md {
if isReservedHeader(k) {
continue
}
for _, v := range vv {
headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
}
}
}
return headerFields, nil
}
func (t *http2Client) createAudience(callHdr *CallHdr) string {
// Create an audience string only if needed.
if len(t.creds) == 0 && callHdr.Creds == nil {
return ""
}
// Construct URI required to get auth request metadata.
// Omit port if it is the default one.
host := strings.TrimSuffix(callHdr.Host, ":443")
pos := strings.LastIndex(callHdr.Method, "/")
if pos == -1 {
pos = len(callHdr.Method)
}
return "https://" + host + callHdr.Method[:pos]
}
func (t *http2Client) getTrAuthData(ctx context.Context, audience string) (map[string]string, error) {
authData := map[string]string{}
for _, c := range t.creds {
data, err := c.GetRequestMetadata(ctx, audience)
if err != nil {
if _, ok := status.FromError(err); ok {
return nil, err
}
return nil, streamErrorf(codes.Unauthenticated, "transport: %v", err)
}
for k, v := range data {
// Capital header names are illegal in HTTP/2.
k = strings.ToLower(k)
authData[k] = v
}
}
return authData, nil
}
func (t *http2Client) getCallAuthData(ctx context.Context, audience string, callHdr *CallHdr) (map[string]string, error) {
callAuthData := map[string]string{}
// Check if credentials.PerRPCCredentials were provided via call options.
// Note: if these credentials are provided both via dial options and call
// options, then both sets of credentials will be applied.
if callCreds := callHdr.Creds; callCreds != nil {
if !t.isSecure && callCreds.RequireTransportSecurity() {
return nil, streamErrorf(codes.Unauthenticated, "transport: cannot send secure credentials on an insecure connection")
}
data, err := callCreds.GetRequestMetadata(ctx, audience)
if err != nil {
return nil, streamErrorf(codes.Internal, "transport: %v", err)
}
for k, v := range data {
// Capital header names are illegal in HTTP/2
k = strings.ToLower(k)
callAuthData[k] = v
}
}
return callAuthData, nil
}
// NewStream creates a stream and registers it into the transport as "active"
// streams.
func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) {
ctx = peer.NewContext(ctx, t.getPeer())
headerFields, err := t.createHeaderFields(ctx, callHdr)
if err != nil {
return nil, err
}
s := t.newStream(ctx, callHdr)
cleanup := func(err error) {
if s.swapState(streamDone) == streamDone {
// If it was already done, return.
return
}
// The stream was unprocessed by the server.
atomic.StoreUint32(&s.unprocessed, 1)
s.write(recvMsg{err: err})
close(s.done)
// If headerChan isn't closed, then close it.
if atomic.SwapUint32(&s.headerDone, 1) == 0 {
close(s.headerChan)
}
}
hdr := &headerFrame{
hf: headerFields,
endStream: false,
initStream: func(id uint32) (bool, error) {
t.mu.Lock()
if state := t.state; state != reachable {
t.mu.Unlock()
// Do a quick cleanup.
err := error(errStreamDrain)
if state == closing {
err = ErrConnClosing
}
cleanup(err)
return false, err
}
t.activeStreams[id] = s
if channelz.IsOn() {
t.czmu.Lock()
t.streamsStarted++
t.lastStreamCreated = time.Now()
t.czmu.Unlock()
}
var sendPing bool
// If the number of active streams change from 0 to 1, then check if keepalive
// has gone dormant. If so, wake it up.
if len(t.activeStreams) == 1 && t.keepaliveEnabled {
select {
case t.awakenKeepalive <- struct{}{}:
sendPing = true
// Fill the awakenKeepalive channel again as this channel must be
// kept non-writable except at the point that the keepalive()
// goroutine is waiting either to be awaken or shutdown.
t.awakenKeepalive <- struct{}{}
default:
}
}
t.mu.Unlock()
return sendPing, nil
},
onOrphaned: cleanup,
wq: s.wq,
}
firstTry := true
var ch chan struct{}
checkForStreamQuota := func(it interface{}) bool {
if t.streamQuota <= 0 { // Can go negative if server decreases it.
if firstTry {
t.waitingStreams++
}
ch = t.streamsQuotaAvailable
return false
}
if !firstTry {
t.waitingStreams--
}
t.streamQuota--
h := it.(*headerFrame)
h.streamID = t.nextID
t.nextID += 2
s.id = h.streamID
s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
if t.streamQuota > 0 && t.waitingStreams > 0 {
select {
case t.streamsQuotaAvailable <- struct{}{}:
default:
}
}
return true
}
for {
success, err := t.controlBuf.executeAndPut(checkForStreamQuota, hdr)
if err != nil {
return nil, err
}
if success {
break
}
firstTry = false
select {
case <-ch:
case <-s.ctx.Done():
return nil, ContextErr(s.ctx.Err())
case <-t.goAway:
return nil, errStreamDrain
case <-t.ctx.Done():
return nil, ErrConnClosing
}
}
if t.statsHandler != nil {
outHeader := &stats.OutHeader{
Client: true,
FullMethod: callHdr.Method,
RemoteAddr: t.remoteAddr,
LocalAddr: t.localAddr,
Compression: callHdr.SendCompress,
}
t.statsHandler.HandleRPC(s.ctx, outHeader)
}
return s, nil
}
// CloseStream clears the footprint of a stream when the stream is not needed any more.
// This must not be executed in reader's goroutine.
func (t *http2Client) CloseStream(s *Stream, err error) {
var (
rst bool
rstCode http2.ErrCode
)
if err != nil {
rst = true
rstCode = http2.ErrCodeCancel
}
t.closeStream(s, err, rst, rstCode, nil, nil, false)
}
func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.ErrCode, st *status.Status, mdata map[string][]string, eosReceived bool) {
// Set stream status to done.
if s.swapState(streamDone) == streamDone {
// If it was already done, return.
return
}
// status and trailers can be updated here without any synchronization because the stream goroutine will
// only read it after it sees an io.EOF error from read or write and we'll write those errors
// only after updating this.
s.status = st
if len(mdata) > 0 {
s.trailer = mdata
}
if err != nil {
// This will unblock reads eventually.
s.write(recvMsg{err: err})
}
// This will unblock write.
close(s.done)
// If headerChan isn't closed, then close it.
if atomic.SwapUint32(&s.headerDone, 1) == 0 {
close(s.headerChan)
}
cleanup := &cleanupStream{
streamID: s.id,
onWrite: func() {
t.mu.Lock()
if t.activeStreams != nil {
delete(t.activeStreams, s.id)
}
t.mu.Unlock()
if channelz.IsOn() {
t.czmu.Lock()
if eosReceived {
t.streamsSucceeded++
} else {
t.streamsFailed++
}
t.czmu.Unlock()
}
},
rst: rst,
rstCode: rstCode,
}
addBackStreamQuota := func(interface{}) bool {
t.streamQuota++
if t.streamQuota > 0 && t.waitingStreams > 0 {
select {
case t.streamsQuotaAvailable <- struct{}{}:
default:
}
}
return true
}
t.controlBuf.executeAndPut(addBackStreamQuota, cleanup)
}
// Close kicks off the shutdown process of the transport. This should be called
// only once on a transport. Once it is called, the transport should not be
// accessed any more.
func (t *http2Client) Close() error {
t.mu.Lock()
// Make sure we only Close once.
if t.state == closing {
t.mu.Unlock()
return nil
}
t.state = closing
streams := t.activeStreams
t.activeStreams = nil
t.mu.Unlock()
t.controlBuf.finish()
t.cancel()
err := t.conn.Close()
if channelz.IsOn() {
channelz.RemoveEntry(t.channelzID)
}
// Notify all active streams.
for _, s := range streams {
t.closeStream(s, ErrConnClosing, false, http2.ErrCodeNo, nil, nil, false)
}
if t.statsHandler != nil {
connEnd := &stats.ConnEnd{
Client: true,
}
t.statsHandler.HandleConn(t.ctx, connEnd)
}
return err
}
// GracefulClose sets the state to draining, which prevents new streams from
// being created and causes the transport to be closed when the last active
// stream is closed. If there are no active streams, the transport is closed
// immediately. This does nothing if the transport is already draining or
// closing.
func (t *http2Client) GracefulClose() error {
t.mu.Lock()
// Make sure we move to draining only from active.
if t.state == draining || t.state == closing {
t.mu.Unlock()
return nil
}
t.state = draining
active := len(t.activeStreams)
t.mu.Unlock()
if active == 0 {
return t.Close()
}
t.controlBuf.put(&incomingGoAway{})
return nil
}
// Write formats the data into HTTP2 data frame(s) and sends it out. The caller
// should proceed only if Write returns nil.
func (t *http2Client) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
if opts.Last {
// If it's the last message, update stream state.
if !s.compareAndSwapState(streamActive, streamWriteDone) {
return errStreamDone
}
} else if s.getState() != streamActive {
return errStreamDone
}
df := &dataFrame{
streamID: s.id,
endStream: opts.Last,
}
if hdr != nil || data != nil { // If it's not an empty data frame.
// Add some data to grpc message header so that we can equally
// distribute bytes across frames.
emptyLen := http2MaxFrameLen - len(hdr)
if emptyLen > len(data) {
emptyLen = len(data)
}
hdr = append(hdr, data[:emptyLen]...)
data = data[emptyLen:]
df.h, df.d = hdr, data
// TODO(mmukhi): The above logic in this if can be moved to loopyWriter's data handler.
if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
return err
}
}
return t.controlBuf.put(df)
}
func (t *http2Client) getStream(f http2.Frame) (*Stream, bool) {
t.mu.Lock()
defer t.mu.Unlock()
s, ok := t.activeStreams[f.Header().StreamID]
return s, ok
}
// adjustWindow sends out extra window update over the initial window size
// of stream if the application is requesting data larger in size than
// the window.
func (t *http2Client) adjustWindow(s *Stream, n uint32) {
if w := s.fc.maybeAdjust(n); w > 0 {
t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
}
}
// updateWindow adjusts the inbound quota for the stream.
// Window updates will be sent out when the cumulative quota
// exceeds the corresponding threshold.
func (t *http2Client) updateWindow(s *Stream, n uint32) {
if w := s.fc.onRead(n); w > 0 {
t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
}
}
// updateFlowControl updates the incoming flow control windows
// for the transport and the stream based on the current bdp
// estimation.
func (t *http2Client) updateFlowControl(n uint32) {
t.mu.Lock()
for _, s := range t.activeStreams {
s.fc.newLimit(n)
}
t.mu.Unlock()
updateIWS := func(interface{}) bool {
t.initialWindowSize = int32(n)
return true
}
t.controlBuf.executeAndPut(updateIWS, &outgoingWindowUpdate{streamID: 0, increment: t.fc.newLimit(n)})
t.controlBuf.put(&outgoingSettings{
ss: []http2.Setting{
{
ID: http2.SettingInitialWindowSize,
Val: n,
},
},
})
}
func (t *http2Client) handleData(f *http2.DataFrame) {
size := f.Header().Length
var sendBDPPing bool
if t.bdpEst != nil {
sendBDPPing = t.bdpEst.add(size)
}
// Decouple connection's flow control from application's read.
// An update on connection's flow control should not depend on
// whether user application has read the data or not. Such a
// restriction is already imposed on the stream's flow control,
// and therefore the sender will be blocked anyways.
// Decoupling the connection flow control will prevent other
// active(fast) streams from starving in presence of slow or
// inactive streams.
//
if w := t.fc.onData(size); w > 0 {
t.controlBuf.put(&outgoingWindowUpdate{
streamID: 0,
increment: w,
})
}
if sendBDPPing {
// Avoid excessive ping detection (e.g. in an L7 proxy)
// by sending a window update prior to the BDP ping.
if w := t.fc.reset(); w > 0 {
t.controlBuf.put(&outgoingWindowUpdate{
streamID: 0,
increment: w,
})
}
t.controlBuf.put(bdpPing)
}
// Select the right stream to dispatch.
s, ok := t.getStream(f)
if !ok {
return
}
if size > 0 {
if err := s.fc.onData(size); err != nil {
t.closeStream(s, io.EOF, true, http2.ErrCodeFlowControl, status.New(codes.Internal, err.Error()), nil, false)
return
}
if f.Header().Flags.Has(http2.FlagDataPadded) {
if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
}
}
// TODO(bradfitz, zhaoq): A copy is required here because there is no
// guarantee f.Data() is consumed before the arrival of next frame.
// Can this copy be eliminated?
if len(f.Data()) > 0 {
data := make([]byte, len(f.Data()))
copy(data, f.Data())
s.write(recvMsg{data: data})
}
}
// The server has closed the stream without sending trailers. Record that
// the read direction is closed, and set the status appropriately.
if f.FrameHeader.Flags.Has(http2.FlagDataEndStream) {
t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.New(codes.Internal, "server closed the stream without sending trailers"), nil, true)
}
}
func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
s, ok := t.getStream(f)
if !ok {
return
}
if f.ErrCode == http2.ErrCodeRefusedStream {
// The stream was unprocessed by the server.
atomic.StoreUint32(&s.unprocessed, 1)
}
statusCode, ok := http2ErrConvTab[f.ErrCode]
if !ok {
warningf("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error %v", f.ErrCode)
statusCode = codes.Unknown
}
t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode), nil, false)
}
func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
if f.IsAck() {
return
}
var maxStreams *uint32
var ss []http2.Setting
f.ForeachSetting(func(s http2.Setting) error {
if s.ID == http2.SettingMaxConcurrentStreams {
maxStreams = new(uint32)
*maxStreams = s.Val
return nil
}
ss = append(ss, s)
return nil
})
if isFirst && maxStreams == nil {
maxStreams = new(uint32)
*maxStreams = math.MaxUint32
}
sf := &incomingSettings{
ss: ss,
}
if maxStreams == nil {
t.controlBuf.put(sf)
return
}
updateStreamQuota := func(interface{}) bool {
delta := int64(*maxStreams) - int64(t.maxConcurrentStreams)
t.maxConcurrentStreams = *maxStreams
t.streamQuota += delta
if delta > 0 && t.waitingStreams > 0 {
close(t.streamsQuotaAvailable) // wake all of them up.
t.streamsQuotaAvailable = make(chan struct{}, 1)
}
return true
}
t.controlBuf.executeAndPut(updateStreamQuota, sf)
}
func (t *http2Client) handlePing(f *http2.PingFrame) {
if f.IsAck() {
// Maybe it's a BDP ping.
if t.bdpEst != nil {
t.bdpEst.calculate(f.Data)
}
return
}
pingAck := &ping{ack: true}
copy(pingAck.data[:], f.Data[:])
t.controlBuf.put(pingAck)
}
func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
t.mu.Lock()
if t.state == closing {
t.mu.Unlock()
return
}
if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
infof("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
}
id := f.LastStreamID
if id > 0 && id%2 != 1 {
t.mu.Unlock()
t.Close()
return
}
// A client can receive multiple GoAways from the server (see
// https://github.com/grpc/grpc-go/issues/1387). The idea is that the first
// GoAway will be sent with an ID of MaxInt32 and the second GoAway will be
// sent after an RTT delay with the ID of the last stream the server will
// process.
//
// Therefore, when we get the first GoAway we don't necessarily close any
// streams. While in case of second GoAway we close all streams created after
// the GoAwayId. This way streams that were in-flight while the GoAway from
// server was being sent don't get killed.
select {
case <-t.goAway: // t.goAway has been closed (i.e.,multiple GoAways).
// If there are multiple GoAways the first one should always have an ID greater than the following ones.
if id > t.prevGoAwayID {
t.mu.Unlock()
t.Close()
return
}
default:
t.setGoAwayReason(f)
close(t.goAway)
t.state = draining
t.controlBuf.put(&incomingGoAway{})
}
// All streams with IDs greater than the GoAwayId
// and smaller than the previous GoAway ID should be killed.
upperLimit := t.prevGoAwayID
if upperLimit == 0 { // This is the first GoAway Frame.
upperLimit = math.MaxUint32 // Kill all streams after the GoAway ID.
}
for streamID, stream := range t.activeStreams {
if streamID > id && streamID <= upperLimit {
// The stream was unprocessed by the server.
atomic.StoreUint32(&stream.unprocessed, 1)
t.closeStream(stream, errStreamDrain, false, http2.ErrCodeNo, statusGoAway, nil, false)
}
}
t.prevGoAwayID = id
active := len(t.activeStreams)
t.mu.Unlock()
if active == 0 {
t.Close()
}
}
// setGoAwayReason sets the value of t.goAwayReason based
// on the GoAway frame received.
// It expects a lock on transport's mutext to be held by
// the caller.
func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
t.goAwayReason = GoAwayNoReason
switch f.ErrCode {
case http2.ErrCodeEnhanceYourCalm:
if string(f.DebugData()) == "too_many_pings" {
t.goAwayReason = GoAwayTooManyPings
}
}
}
func (t *http2Client) GetGoAwayReason() GoAwayReason {
t.mu.Lock()
defer t.mu.Unlock()
return t.goAwayReason
}
func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) {
t.controlBuf.put(&incomingWindowUpdate{
streamID: f.Header().StreamID,
increment: f.Increment,
})
}
// operateHeaders takes action on the decoded headers.
func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
s, ok := t.getStream(frame)
if !ok {
return
}
atomic.StoreUint32(&s.bytesReceived, 1)
var state decodeState
if err := state.decodeResponseHeader(frame); err != nil {
t.closeStream(s, err, true, http2.ErrCodeProtocol, nil, nil, false)
// Something wrong. Stops reading even when there is remaining.
return
}
endStream := frame.StreamEnded()
var isHeader bool
defer func() {
if t.statsHandler != nil {
if isHeader {
inHeader := &stats.InHeader{
Client: true,
WireLength: int(frame.Header().Length),
}
t.statsHandler.HandleRPC(s.ctx, inHeader)
} else {
inTrailer := &stats.InTrailer{
Client: true,
WireLength: int(frame.Header().Length),
}
t.statsHandler.HandleRPC(s.ctx, inTrailer)
}
}
}()
// If headers haven't been received yet.
if atomic.SwapUint32(&s.headerDone, 1) == 0 {
if !endStream {
// Headers frame is not actually a trailers-only frame.
isHeader = true
// These values can be set without any synchronization because
// stream goroutine will read it only after seeing a closed
// headerChan which we'll close after setting this.
s.recvCompress = state.encoding
if len(state.mdata) > 0 {
s.header = state.mdata
}
}
close(s.headerChan)
}
if !endStream {
return
}
t.closeStream(s, io.EOF, false, http2.ErrCodeNo, state.status(), state.mdata, true)
}
// reader runs as a separate goroutine in charge of reading data from network
// connection.
//
// TODO(zhaoq): currently one reader per transport. Investigate whether this is
// optimal.
// TODO(zhaoq): Check the validity of the incoming frame sequence.
func (t *http2Client) reader() {
defer close(t.readerDone)
// Check the validity of server preface.
frame, err := t.framer.fr.ReadFrame()
if err != nil {
t.Close()
return
}
if t.keepaliveEnabled {
atomic.CompareAndSwapUint32(&t.activity, 0, 1)
}
sf, ok := frame.(*http2.SettingsFrame)
if !ok {
t.Close()
return
}
t.onSuccess()
t.handleSettings(sf, true)
// loop to keep reading incoming messages on this transport.
for {
frame, err := t.framer.fr.ReadFrame()
if t.keepaliveEnabled {
atomic.CompareAndSwapUint32(&t.activity, 0, 1)
}
if err != nil {
// Abort an active stream if the http2.Framer returns a
// http2.StreamError. This can happen only if the server's response
// is malformed http2.
if se, ok := err.(http2.StreamError); ok {
t.mu.Lock()
s := t.activeStreams[se.StreamID]
t.mu.Unlock()
if s != nil {
// use error detail to provide better err message
t.closeStream(s, streamErrorf(http2ErrConvTab[se.Code], "%v", t.framer.fr.ErrorDetail()), true, http2.ErrCodeProtocol, nil, nil, false)
}
continue
} else {
// Transport error.
t.Close()
return
}
}
switch frame := frame.(type) {
case *http2.MetaHeadersFrame:
t.operateHeaders(frame)
case *http2.DataFrame:
t.handleData(frame)
case *http2.RSTStreamFrame:
t.handleRSTStream(frame)
case *http2.SettingsFrame:
t.handleSettings(frame, false)
case *http2.PingFrame:
t.handlePing(frame)
case *http2.GoAwayFrame:
t.handleGoAway(frame)
case *http2.WindowUpdateFrame:
t.handleWindowUpdate(frame)
default:
errorf("transport: http2Client.reader got unhandled frame type %v.", frame)
}
}
}
// keepalive running in a separate goroutune makes sure the connection is alive by sending pings.
func (t *http2Client) keepalive() {
p := &ping{data: [8]byte{}}
timer := time.NewTimer(t.kp.Time)
for {
select {
case <-timer.C:
if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
timer.Reset(t.kp.Time)
continue
}
// Check if keepalive should go dormant.
t.mu.Lock()
if len(t.activeStreams) < 1 && !t.kp.PermitWithoutStream {
// Make awakenKeepalive writable.
<-t.awakenKeepalive
t.mu.Unlock()
select {
case <-t.awakenKeepalive:
// If the control gets here a ping has been sent
// need to reset the timer with keepalive.Timeout.
case <-t.ctx.Done():
return
}
} else {
t.mu.Unlock()
if channelz.IsOn() {
t.czmu.Lock()
t.kpCount++
t.czmu.Unlock()
}
// Send ping.
t.controlBuf.put(p)
}
// By the time control gets here a ping has been sent one way or the other.
timer.Reset(t.kp.Timeout)
select {
case <-timer.C:
if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
timer.Reset(t.kp.Time)
continue
}
t.Close()
return
case <-t.ctx.Done():
if !timer.Stop() {
<-timer.C
}
return
}
case <-t.ctx.Done():
if !timer.Stop() {
<-timer.C
}
return
}
}
}
func (t *http2Client) Error() <-chan struct{} {
return t.ctx.Done()
}
func (t *http2Client) GoAway() <-chan struct{} {
return t.goAway
}
func (t *http2Client) ChannelzMetric() *channelz.SocketInternalMetric {
t.czmu.RLock()
s := channelz.SocketInternalMetric{
StreamsStarted: t.streamsStarted,
StreamsSucceeded: t.streamsSucceeded,
StreamsFailed: t.streamsFailed,
MessagesSent: t.msgSent,
MessagesReceived: t.msgRecv,
KeepAlivesSent: t.kpCount,
LastLocalStreamCreatedTimestamp: t.lastStreamCreated,
LastMessageSentTimestamp: t.lastMsgSent,
LastMessageReceivedTimestamp: t.lastMsgRecv,
LocalFlowControlWindow: int64(t.fc.getSize()),
//socket options
LocalAddr: t.localAddr,
RemoteAddr: t.remoteAddr,
// Security
// RemoteName :
}
t.czmu.RUnlock()
s.RemoteFlowControlWindow = t.getOutFlowWindow()
return &s
}
func (t *http2Client) IncrMsgSent() {
t.czmu.Lock()
t.msgSent++
t.lastMsgSent = time.Now()
t.czmu.Unlock()
}
func (t *http2Client) IncrMsgRecv() {
t.czmu.Lock()
t.msgRecv++
t.lastMsgRecv = time.Now()
t.czmu.Unlock()
}
func (t *http2Client) getOutFlowWindow() int64 {
resp := make(chan uint32, 1)
timer := time.NewTimer(time.Second)
defer timer.Stop()
t.controlBuf.put(&outFlowControlSizeRequest{resp})
select {
case sz := <-resp:
return int64(sz)
case <-t.ctxDone:
return -1
case <-timer.C:
return -2
}
}