1/*
2 *
3 * Copyright 2014 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19package transport
20
21import (
22 "context"
23 "fmt"
24 "io"
25 "math"
26 "net"
27 "net/http"
28 "path/filepath"
29 "strconv"
30 "strings"
31 "sync"
32 "sync/atomic"
33 "time"
34
35 "golang.org/x/net/http2"
36 "golang.org/x/net/http2/hpack"
37 "google.golang.org/grpc/codes"
38 "google.golang.org/grpc/credentials"
39 "google.golang.org/grpc/internal"
40 "google.golang.org/grpc/internal/channelz"
41 icredentials "google.golang.org/grpc/internal/credentials"
42 "google.golang.org/grpc/internal/grpclog"
43 "google.golang.org/grpc/internal/grpcsync"
44 "google.golang.org/grpc/internal/grpcutil"
45 imetadata "google.golang.org/grpc/internal/metadata"
46 "google.golang.org/grpc/internal/proxyattributes"
47 istatus "google.golang.org/grpc/internal/status"
48 isyscall "google.golang.org/grpc/internal/syscall"
49 "google.golang.org/grpc/internal/transport/networktype"
50 "google.golang.org/grpc/keepalive"
51 "google.golang.org/grpc/mem"
52 "google.golang.org/grpc/metadata"
53 "google.golang.org/grpc/peer"
54 "google.golang.org/grpc/resolver"
55 "google.golang.org/grpc/stats"
56 "google.golang.org/grpc/status"
57)
58
59// clientConnectionCounter counts the number of connections a client has
60// initiated (equal to the number of http2Clients created). Must be accessed
61// atomically.
62var clientConnectionCounter uint64
63
64var goAwayLoopyWriterTimeout = 5 * time.Second
65
66var metadataFromOutgoingContextRaw = internal.FromOutgoingContextRaw.(func(context.Context) (metadata.MD, [][]string, bool))
67
68// http2Client implements the ClientTransport interface with HTTP2.
69type http2Client struct {
70 lastRead int64 // Keep this field 64-bit aligned. Accessed atomically.
71 ctx context.Context
72 cancel context.CancelFunc
73 ctxDone <-chan struct{} // Cache the ctx.Done() chan.
74 userAgent string
75 // address contains the resolver returned address for this transport.
76 // If the `ServerName` field is set, it takes precedence over `CallHdr.Host`
77 // passed to `NewStream`, when determining the :authority header.
78 address resolver.Address
79 md metadata.MD
80 conn net.Conn // underlying communication channel
81 loopy *loopyWriter
82 remoteAddr net.Addr
83 localAddr net.Addr
84 authInfo credentials.AuthInfo // auth info about the connection
85
86 readerDone chan struct{} // sync point to enable testing.
87 writerDone chan struct{} // sync point to enable testing.
88 // goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor)
89 // that the server sent GoAway on this transport.
90 goAway chan struct{}
91 keepaliveDone chan struct{} // Closed when the keepalive goroutine exits.
92 framer *framer
93 // controlBuf delivers all the control related tasks (e.g., window
94 // updates, reset streams, and various settings) to the controller.
95 // Do not access controlBuf with mu held.
96 controlBuf *controlBuffer
97 fc *trInFlow
98 // The scheme used: https if TLS is on, http otherwise.
99 scheme string
100
101 isSecure bool
102
103 perRPCCreds []credentials.PerRPCCredentials
104
105 kp keepalive.ClientParameters
106 keepaliveEnabled bool
107
108 statsHandlers []stats.Handler
109
110 initialWindowSize int32
111
112 // configured by peer through SETTINGS_MAX_HEADER_LIST_SIZE
113 maxSendHeaderListSize *uint32
114
115 bdpEst *bdpEstimator
116
117 maxConcurrentStreams uint32
118 streamQuota int64
119 streamsQuotaAvailable chan struct{}
120 waitingStreams uint32
121 registeredCompressors string
122
123 // Do not access controlBuf with mu held.
124 mu sync.Mutex // guard the following variables
125 nextID uint32
126 state transportState
127 activeStreams map[uint32]*ClientStream
128 // prevGoAway ID records the Last-Stream-ID in the previous GOAway frame.
129 prevGoAwayID uint32
130 // goAwayReason records the http2.ErrCode and debug data received with the
131 // GoAway frame.
132 goAwayReason GoAwayReason
133 // goAwayDebugMessage contains a detailed human readable string about a
134 // GoAway frame, useful for error messages.
135 goAwayDebugMessage string
136 // A condition variable used to signal when the keepalive goroutine should
137 // go dormant. The condition for dormancy is based on the number of active
138 // streams and the `PermitWithoutStream` keepalive client parameter. And
139 // since the number of active streams is guarded by the above mutex, we use
140 // the same for this condition variable as well.
141 kpDormancyCond *sync.Cond
142 // A boolean to track whether the keepalive goroutine is dormant or not.
143 // This is checked before attempting to signal the above condition
144 // variable.
145 kpDormant bool
146
147 channelz *channelz.Socket
148
149 onClose func(GoAwayReason)
150
151 bufferPool mem.BufferPool
152
153 connectionID uint64
154 logger *grpclog.PrefixLogger
155}
156
157func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, grpcUA string) (net.Conn, error) {
158 address := addr.Addr
159 networkType, ok := networktype.Get(addr)
160 if fn != nil {
161 // Special handling for unix scheme with custom dialer. Back in the day,
162 // we did not have a unix resolver and therefore targets with a unix
163 // scheme would end up using the passthrough resolver. So, user's used a
164 // custom dialer in this case and expected the original dial target to
165 // be passed to the custom dialer. Now, we have a unix resolver. But if
166 // a custom dialer is specified, we want to retain the old behavior in
167 // terms of the address being passed to the custom dialer.
168 if networkType == "unix" && !strings.HasPrefix(address, "\x00") {
169 // Supported unix targets are either "unix://absolute-path" or
170 // "unix:relative-path".
171 if filepath.IsAbs(address) {
172 return fn(ctx, "unix://"+address)
173 }
174 return fn(ctx, "unix:"+address)
175 }
176 return fn(ctx, address)
177 }
178 if !ok {
179 networkType, address = parseDialTarget(address)
180 }
181 if opts, present := proxyattributes.Get(addr); present {
182 return proxyDial(ctx, addr, grpcUA, opts)
183 }
184 return internal.NetDialerWithTCPKeepalive().DialContext(ctx, networkType, address)
185}
186
187func isTemporary(err error) bool {
188 switch err := err.(type) {
189 case interface {
190 Temporary() bool
191 }:
192 return err.Temporary()
193 case interface {
194 Timeout() bool
195 }:
196 // Timeouts may be resolved upon retry, and are thus treated as
197 // temporary.
198 return err.Timeout()
199 }
200 return true
201}
202
203// NewHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
204// and starts to receive messages on it. Non-nil error returns if construction
205// fails.
206func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (_ ClientTransport, err error) {
207 scheme := "http"
208 ctx, cancel := context.WithCancel(ctx)
209 defer func() {
210 if err != nil {
211 cancel()
212 }
213 }()
214
215 // gRPC, resolver, balancer etc. can specify arbitrary data in the
216 // Attributes field of resolver.Address, which is shoved into connectCtx
217 // and passed to the dialer and credential handshaker. This makes it possible for
218 // address specific arbitrary data to reach custom dialers and credential handshakers.
219 connectCtx = icredentials.NewClientHandshakeInfoContext(connectCtx, credentials.ClientHandshakeInfo{Attributes: addr.Attributes})
220
221 conn, err := dial(connectCtx, opts.Dialer, addr, opts.UserAgent)
222 if err != nil {
223 if opts.FailOnNonTempDialError {
224 return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
225 }
226 return nil, connectionErrorf(true, err, "transport: Error while dialing: %v", err)
227 }
228
229 // Any further errors will close the underlying connection
230 defer func(conn net.Conn) {
231 if err != nil {
232 conn.Close()
233 }
234 }(conn)
235
236 // The following defer and goroutine monitor the connectCtx for cancellation
237 // and deadline. On context expiration, the connection is hard closed and
238 // this function will naturally fail as a result. Otherwise, the defer
239 // waits for the goroutine to exit to prevent the context from being
240 // monitored (and to prevent the connection from ever being closed) after
241 // returning from this function.
242 ctxMonitorDone := grpcsync.NewEvent()
243 newClientCtx, newClientDone := context.WithCancel(connectCtx)
244 defer func() {
245 newClientDone() // Awaken the goroutine below if connectCtx hasn't expired.
246 <-ctxMonitorDone.Done() // Wait for the goroutine below to exit.
247 }()
248 go func(conn net.Conn) {
249 defer ctxMonitorDone.Fire() // Signal this goroutine has exited.
250 <-newClientCtx.Done() // Block until connectCtx expires or the defer above executes.
251 if err := connectCtx.Err(); err != nil {
252 // connectCtx expired before exiting the function. Hard close the connection.
253 if logger.V(logLevel) {
254 logger.Infof("Aborting due to connect deadline expiring: %v", err)
255 }
256 conn.Close()
257 }
258 }(conn)
259
260 kp := opts.KeepaliveParams
261 // Validate keepalive parameters.
262 if kp.Time == 0 {
263 kp.Time = defaultClientKeepaliveTime
264 }
265 if kp.Timeout == 0 {
266 kp.Timeout = defaultClientKeepaliveTimeout
267 }
268 keepaliveEnabled := false
269 if kp.Time != infinity {
270 if err = isyscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
271 return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
272 }
273 keepaliveEnabled = true
274 }
275 var (
276 isSecure bool
277 authInfo credentials.AuthInfo
278 )
279 transportCreds := opts.TransportCredentials
280 perRPCCreds := opts.PerRPCCredentials
281
282 if b := opts.CredsBundle; b != nil {
283 if t := b.TransportCredentials(); t != nil {
284 transportCreds = t
285 }
286 if t := b.PerRPCCredentials(); t != nil {
287 perRPCCreds = append(perRPCCreds, t)
288 }
289 }
290 if transportCreds != nil {
291 conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.ServerName, conn)
292 if err != nil {
293 return nil, connectionErrorf(isTemporary(err), err, "transport: authentication handshake failed: %v", err)
294 }
295 for _, cd := range perRPCCreds {
296 if cd.RequireTransportSecurity() {
297 if ci, ok := authInfo.(interface {
298 GetCommonAuthInfo() credentials.CommonAuthInfo
299 }); ok {
300 secLevel := ci.GetCommonAuthInfo().SecurityLevel
301 if secLevel != credentials.InvalidSecurityLevel && secLevel < credentials.PrivacyAndIntegrity {
302 return nil, connectionErrorf(true, nil, "transport: cannot send secure credentials on an insecure connection")
303 }
304 }
305 }
306 }
307 isSecure = true
308 if transportCreds.Info().SecurityProtocol == "tls" {
309 scheme = "https"
310 }
311 }
312 dynamicWindow := true
313 icwz := int32(initialWindowSize)
314 if opts.InitialConnWindowSize >= defaultWindowSize {
315 icwz = opts.InitialConnWindowSize
316 dynamicWindow = false
317 }
318 writeBufSize := opts.WriteBufferSize
319 readBufSize := opts.ReadBufferSize
320 maxHeaderListSize := defaultClientMaxHeaderListSize
321 if opts.MaxHeaderListSize != nil {
322 maxHeaderListSize = *opts.MaxHeaderListSize
323 }
324
325 t := &http2Client{
326 ctx: ctx,
327 ctxDone: ctx.Done(), // Cache Done chan.
328 cancel: cancel,
329 userAgent: opts.UserAgent,
330 registeredCompressors: grpcutil.RegisteredCompressors(),
331 address: addr,
332 conn: conn,
333 remoteAddr: conn.RemoteAddr(),
334 localAddr: conn.LocalAddr(),
335 authInfo: authInfo,
336 readerDone: make(chan struct{}),
337 writerDone: make(chan struct{}),
338 goAway: make(chan struct{}),
339 keepaliveDone: make(chan struct{}),
340 framer: newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize),
341 fc: &trInFlow{limit: uint32(icwz)},
342 scheme: scheme,
343 activeStreams: make(map[uint32]*ClientStream),
344 isSecure: isSecure,
345 perRPCCreds: perRPCCreds,
346 kp: kp,
347 statsHandlers: opts.StatsHandlers,
348 initialWindowSize: initialWindowSize,
349 nextID: 1,
350 maxConcurrentStreams: defaultMaxStreamsClient,
351 streamQuota: defaultMaxStreamsClient,
352 streamsQuotaAvailable: make(chan struct{}, 1),
353 keepaliveEnabled: keepaliveEnabled,
354 bufferPool: opts.BufferPool,
355 onClose: onClose,
356 }
357 var czSecurity credentials.ChannelzSecurityValue
358 if au, ok := authInfo.(credentials.ChannelzSecurityInfo); ok {
359 czSecurity = au.GetSecurityValue()
360 }
361 t.channelz = channelz.RegisterSocket(
362 &channelz.Socket{
363 SocketType: channelz.SocketTypeNormal,
364 Parent: opts.ChannelzParent,
365 SocketMetrics: channelz.SocketMetrics{},
366 EphemeralMetrics: t.socketMetrics,
367 LocalAddr: t.localAddr,
368 RemoteAddr: t.remoteAddr,
369 SocketOptions: channelz.GetSocketOption(t.conn),
370 Security: czSecurity,
371 })
372 t.logger = prefixLoggerForClientTransport(t)
373 // Add peer information to the http2client context.
374 t.ctx = peer.NewContext(t.ctx, t.getPeer())
375
376 if md, ok := addr.Metadata.(*metadata.MD); ok {
377 t.md = *md
378 } else if md := imetadata.Get(addr); md != nil {
379 t.md = md
380 }
381 t.controlBuf = newControlBuffer(t.ctxDone)
382 if opts.InitialWindowSize >= defaultWindowSize {
383 t.initialWindowSize = opts.InitialWindowSize
384 dynamicWindow = false
385 }
386 if dynamicWindow {
387 t.bdpEst = &bdpEstimator{
388 bdp: initialWindowSize,
389 updateFlowControl: t.updateFlowControl,
390 }
391 }
392 for _, sh := range t.statsHandlers {
393 t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
394 RemoteAddr: t.remoteAddr,
395 LocalAddr: t.localAddr,
396 })
397 connBegin := &stats.ConnBegin{
398 Client: true,
399 }
400 sh.HandleConn(t.ctx, connBegin)
401 }
402 if t.keepaliveEnabled {
403 t.kpDormancyCond = sync.NewCond(&t.mu)
404 go t.keepalive()
405 }
406
407 // Start the reader goroutine for incoming messages. Each transport has a
408 // dedicated goroutine which reads HTTP2 frames from the network. Then it
409 // dispatches the frame to the corresponding stream entity. When the
410 // server preface is received, readerErrCh is closed. If an error occurs
411 // first, an error is pushed to the channel. This must be checked before
412 // returning from this function.
413 readerErrCh := make(chan error, 1)
414 go t.reader(readerErrCh)
415 defer func() {
416 if err != nil {
417 // writerDone should be closed since the loopy goroutine
418 // wouldn't have started in the case this function returns an error.
419 close(t.writerDone)
420 t.Close(err)
421 }
422 }()
423
424 // Send connection preface to server.
425 n, err := t.conn.Write(clientPreface)
426 if err != nil {
427 err = connectionErrorf(true, err, "transport: failed to write client preface: %v", err)
428 return nil, err
429 }
430 if n != len(clientPreface) {
431 err = connectionErrorf(true, nil, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
432 return nil, err
433 }
434 var ss []http2.Setting
435
436 if t.initialWindowSize != defaultWindowSize {
437 ss = append(ss, http2.Setting{
438 ID: http2.SettingInitialWindowSize,
439 Val: uint32(t.initialWindowSize),
440 })
441 }
442 if opts.MaxHeaderListSize != nil {
443 ss = append(ss, http2.Setting{
444 ID: http2.SettingMaxHeaderListSize,
445 Val: *opts.MaxHeaderListSize,
446 })
447 }
448 err = t.framer.fr.WriteSettings(ss...)
449 if err != nil {
450 err = connectionErrorf(true, err, "transport: failed to write initial settings frame: %v", err)
451 return nil, err
452 }
453 // Adjust the connection flow control window if needed.
454 if delta := uint32(icwz - defaultWindowSize); delta > 0 {
455 if err := t.framer.fr.WriteWindowUpdate(0, delta); err != nil {
456 err = connectionErrorf(true, err, "transport: failed to write window update: %v", err)
457 return nil, err
458 }
459 }
460
461 t.connectionID = atomic.AddUint64(&clientConnectionCounter, 1)
462
463 if err := t.framer.writer.Flush(); err != nil {
464 return nil, err
465 }
466 // Block until the server preface is received successfully or an error occurs.
467 if err = <-readerErrCh; err != nil {
468 return nil, err
469 }
470 go func() {
471 t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger, t.outgoingGoAwayHandler, t.bufferPool)
472 if err := t.loopy.run(); !isIOError(err) {
473 // Immediately close the connection, as the loopy writer returns
474 // when there are no more active streams and we were draining (the
475 // server sent a GOAWAY). For I/O errors, the reader will hit it
476 // after draining any remaining incoming data.
477 t.conn.Close()
478 }
479 close(t.writerDone)
480 }()
481 return t, nil
482}
483
484func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *ClientStream {
485 // TODO(zhaoq): Handle uint32 overflow of Stream.id.
486 s := &ClientStream{
487 Stream: &Stream{
488 method: callHdr.Method,
489 sendCompress: callHdr.SendCompress,
490 buf: newRecvBuffer(),
491 contentSubtype: callHdr.ContentSubtype,
492 },
493 ct: t,
494 done: make(chan struct{}),
495 headerChan: make(chan struct{}),
496 doneFunc: callHdr.DoneFunc,
497 }
498 s.wq = newWriteQuota(defaultWriteQuota, s.done)
499 s.requestRead = func(n int) {
500 t.adjustWindow(s, uint32(n))
501 }
502 // The client side stream context should have exactly the same life cycle with the user provided context.
503 // That means, s.ctx should be read-only. And s.ctx is done iff ctx is done.
504 // So we use the original context here instead of creating a copy.
505 s.ctx = ctx
506 s.trReader = &transportReader{
507 reader: &recvBufferReader{
508 ctx: s.ctx,
509 ctxDone: s.ctx.Done(),
510 recv: s.buf,
511 closeStream: func(err error) {
512 s.Close(err)
513 },
514 },
515 windowHandler: func(n int) {
516 t.updateWindow(s, uint32(n))
517 },
518 }
519 return s
520}
521
522func (t *http2Client) getPeer() *peer.Peer {
523 return &peer.Peer{
524 Addr: t.remoteAddr,
525 AuthInfo: t.authInfo, // Can be nil
526 LocalAddr: t.localAddr,
527 }
528}
529
530// OutgoingGoAwayHandler writes a GOAWAY to the connection. Always returns (false, err) as we want the GoAway
531// to be the last frame loopy writes to the transport.
532func (t *http2Client) outgoingGoAwayHandler(g *goAway) (bool, error) {
533 t.mu.Lock()
534 maxStreamID := t.nextID - 2
535 t.mu.Unlock()
536 if err := t.framer.fr.WriteGoAway(maxStreamID, http2.ErrCodeNo, g.debugData); err != nil {
537 return false, err
538 }
539 return false, g.closeConn
540}
541
542func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr) ([]hpack.HeaderField, error) {
543 aud := t.createAudience(callHdr)
544 ri := credentials.RequestInfo{
545 Method: callHdr.Method,
546 AuthInfo: t.authInfo,
547 }
548 ctxWithRequestInfo := icredentials.NewRequestInfoContext(ctx, ri)
549 authData, err := t.getTrAuthData(ctxWithRequestInfo, aud)
550 if err != nil {
551 return nil, err
552 }
553 callAuthData, err := t.getCallAuthData(ctxWithRequestInfo, aud, callHdr)
554 if err != nil {
555 return nil, err
556 }
557 // TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
558 // first and create a slice of that exact size.
559 // Make the slice of certain predictable size to reduce allocations made by append.
560 hfLen := 7 // :method, :scheme, :path, :authority, content-type, user-agent, te
561 hfLen += len(authData) + len(callAuthData)
562 headerFields := make([]hpack.HeaderField, 0, hfLen)
563 headerFields = append(headerFields, hpack.HeaderField{Name: ":method", Value: "POST"})
564 headerFields = append(headerFields, hpack.HeaderField{Name: ":scheme", Value: t.scheme})
565 headerFields = append(headerFields, hpack.HeaderField{Name: ":path", Value: callHdr.Method})
566 headerFields = append(headerFields, hpack.HeaderField{Name: ":authority", Value: callHdr.Host})
567 headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: grpcutil.ContentType(callHdr.ContentSubtype)})
568 headerFields = append(headerFields, hpack.HeaderField{Name: "user-agent", Value: t.userAgent})
569 headerFields = append(headerFields, hpack.HeaderField{Name: "te", Value: "trailers"})
570 if callHdr.PreviousAttempts > 0 {
571 headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-previous-rpc-attempts", Value: strconv.Itoa(callHdr.PreviousAttempts)})
572 }
573
574 registeredCompressors := t.registeredCompressors
575 if callHdr.SendCompress != "" {
576 headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress})
577 // Include the outgoing compressor name when compressor is not registered
578 // via encoding.RegisterCompressor. This is possible when client uses
579 // WithCompressor dial option.
580 if !grpcutil.IsCompressorNameRegistered(callHdr.SendCompress) {
581 if registeredCompressors != "" {
582 registeredCompressors += ","
583 }
584 registeredCompressors += callHdr.SendCompress
585 }
586 }
587
588 if registeredCompressors != "" {
589 headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-accept-encoding", Value: registeredCompressors})
590 }
591 if dl, ok := ctx.Deadline(); ok {
592 // Send out timeout regardless its value. The server can detect timeout context by itself.
593 // TODO(mmukhi): Perhaps this field should be updated when actually writing out to the wire.
594 timeout := time.Until(dl)
595 headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-timeout", Value: grpcutil.EncodeDuration(timeout)})
596 }
597 for k, v := range authData {
598 headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
599 }
600 for k, v := range callAuthData {
601 headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
602 }
603
604 if md, added, ok := metadataFromOutgoingContextRaw(ctx); ok {
605 var k string
606 for k, vv := range md {
607 // HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
608 if isReservedHeader(k) {
609 continue
610 }
611 for _, v := range vv {
612 headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
613 }
614 }
615 for _, vv := range added {
616 for i, v := range vv {
617 if i%2 == 0 {
618 k = strings.ToLower(v)
619 continue
620 }
621 // HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
622 if isReservedHeader(k) {
623 continue
624 }
625 headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
626 }
627 }
628 }
629 for k, vv := range t.md {
630 if isReservedHeader(k) {
631 continue
632 }
633 for _, v := range vv {
634 headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
635 }
636 }
637 return headerFields, nil
638}
639
640func (t *http2Client) createAudience(callHdr *CallHdr) string {
641 // Create an audience string only if needed.
642 if len(t.perRPCCreds) == 0 && callHdr.Creds == nil {
643 return ""
644 }
645 // Construct URI required to get auth request metadata.
646 // Omit port if it is the default one.
647 host := strings.TrimSuffix(callHdr.Host, ":443")
648 pos := strings.LastIndex(callHdr.Method, "/")
649 if pos == -1 {
650 pos = len(callHdr.Method)
651 }
652 return "https://" + host + callHdr.Method[:pos]
653}
654
655func (t *http2Client) getTrAuthData(ctx context.Context, audience string) (map[string]string, error) {
656 if len(t.perRPCCreds) == 0 {
657 return nil, nil
658 }
659 authData := map[string]string{}
660 for _, c := range t.perRPCCreds {
661 data, err := c.GetRequestMetadata(ctx, audience)
662 if err != nil {
663 if st, ok := status.FromError(err); ok {
664 // Restrict the code to the list allowed by gRFC A54.
665 if istatus.IsRestrictedControlPlaneCode(st) {
666 err = status.Errorf(codes.Internal, "transport: received per-RPC creds error with illegal status: %v", err)
667 }
668 return nil, err
669 }
670
671 return nil, status.Errorf(codes.Unauthenticated, "transport: per-RPC creds failed due to error: %v", err)
672 }
673 for k, v := range data {
674 // Capital header names are illegal in HTTP/2.
675 k = strings.ToLower(k)
676 authData[k] = v
677 }
678 }
679 return authData, nil
680}
681
682func (t *http2Client) getCallAuthData(ctx context.Context, audience string, callHdr *CallHdr) (map[string]string, error) {
683 var callAuthData map[string]string
684 // Check if credentials.PerRPCCredentials were provided via call options.
685 // Note: if these credentials are provided both via dial options and call
686 // options, then both sets of credentials will be applied.
687 if callCreds := callHdr.Creds; callCreds != nil {
688 if callCreds.RequireTransportSecurity() {
689 ri, _ := credentials.RequestInfoFromContext(ctx)
690 if !t.isSecure || credentials.CheckSecurityLevel(ri.AuthInfo, credentials.PrivacyAndIntegrity) != nil {
691 return nil, status.Error(codes.Unauthenticated, "transport: cannot send secure credentials on an insecure connection")
692 }
693 }
694 data, err := callCreds.GetRequestMetadata(ctx, audience)
695 if err != nil {
696 if st, ok := status.FromError(err); ok {
697 // Restrict the code to the list allowed by gRFC A54.
698 if istatus.IsRestrictedControlPlaneCode(st) {
699 err = status.Errorf(codes.Internal, "transport: received per-RPC creds error with illegal status: %v", err)
700 }
701 return nil, err
702 }
703 return nil, status.Errorf(codes.Internal, "transport: per-RPC creds failed due to error: %v", err)
704 }
705 callAuthData = make(map[string]string, len(data))
706 for k, v := range data {
707 // Capital header names are illegal in HTTP/2
708 k = strings.ToLower(k)
709 callAuthData[k] = v
710 }
711 }
712 return callAuthData, nil
713}
714
715// NewStreamError wraps an error and reports additional information. Typically
716// NewStream errors result in transparent retry, as they mean nothing went onto
717// the wire. However, there are two notable exceptions:
718//
719// 1. If the stream headers violate the max header list size allowed by the
720// server. It's possible this could succeed on another transport, even if
721// it's unlikely, but do not transparently retry.
722// 2. If the credentials errored when requesting their headers. In this case,
723// it's possible a retry can fix the problem, but indefinitely transparently
724// retrying is not appropriate as it is likely the credentials, if they can
725// eventually succeed, would need I/O to do so.
726type NewStreamError struct {
727 Err error
728
729 AllowTransparentRetry bool
730}
731
732func (e NewStreamError) Error() string {
733 return e.Err.Error()
734}
735
736// NewStream creates a stream and registers it into the transport as "active"
737// streams. All non-nil errors returned will be *NewStreamError.
738func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*ClientStream, error) {
739 ctx = peer.NewContext(ctx, t.getPeer())
740
741 // ServerName field of the resolver returned address takes precedence over
742 // Host field of CallHdr to determine the :authority header. This is because,
743 // the ServerName field takes precedence for server authentication during
744 // TLS handshake, and the :authority header should match the value used
745 // for server authentication.
746 if t.address.ServerName != "" {
747 newCallHdr := *callHdr
748 newCallHdr.Host = t.address.ServerName
749 callHdr = &newCallHdr
750 }
751
752 headerFields, err := t.createHeaderFields(ctx, callHdr)
753 if err != nil {
754 return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
755 }
756 s := t.newStream(ctx, callHdr)
757 cleanup := func(err error) {
758 if s.swapState(streamDone) == streamDone {
759 // If it was already done, return.
760 return
761 }
762 // The stream was unprocessed by the server.
763 s.unprocessed.Store(true)
764 s.write(recvMsg{err: err})
765 close(s.done)
766 // If headerChan isn't closed, then close it.
767 if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
768 close(s.headerChan)
769 }
770 }
771 hdr := &headerFrame{
772 hf: headerFields,
773 endStream: false,
774 initStream: func(uint32) error {
775 t.mu.Lock()
776 // TODO: handle transport closure in loopy instead and remove this
777 // initStream is never called when transport is draining.
778 if t.state == closing {
779 t.mu.Unlock()
780 cleanup(ErrConnClosing)
781 return ErrConnClosing
782 }
783 if channelz.IsOn() {
784 t.channelz.SocketMetrics.StreamsStarted.Add(1)
785 t.channelz.SocketMetrics.LastLocalStreamCreatedTimestamp.Store(time.Now().UnixNano())
786 }
787 // If the keepalive goroutine has gone dormant, wake it up.
788 if t.kpDormant {
789 t.kpDormancyCond.Signal()
790 }
791 t.mu.Unlock()
792 return nil
793 },
794 onOrphaned: cleanup,
795 wq: s.wq,
796 }
797 firstTry := true
798 var ch chan struct{}
799 transportDrainRequired := false
800 checkForStreamQuota := func() bool {
801 if t.streamQuota <= 0 { // Can go negative if server decreases it.
802 if firstTry {
803 t.waitingStreams++
804 }
805 ch = t.streamsQuotaAvailable
806 return false
807 }
808 if !firstTry {
809 t.waitingStreams--
810 }
811 t.streamQuota--
812
813 t.mu.Lock()
814 if t.state == draining || t.activeStreams == nil { // Can be niled from Close().
815 t.mu.Unlock()
816 return false // Don't create a stream if the transport is already closed.
817 }
818
819 hdr.streamID = t.nextID
820 t.nextID += 2
821 // Drain client transport if nextID > MaxStreamID which signals gRPC that
822 // the connection is closed and a new one must be created for subsequent RPCs.
823 transportDrainRequired = t.nextID > MaxStreamID
824
825 s.id = hdr.streamID
826 s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
827 t.activeStreams[s.id] = s
828 t.mu.Unlock()
829
830 if t.streamQuota > 0 && t.waitingStreams > 0 {
831 select {
832 case t.streamsQuotaAvailable <- struct{}{}:
833 default:
834 }
835 }
836 return true
837 }
838 var hdrListSizeErr error
839 checkForHeaderListSize := func() bool {
840 if t.maxSendHeaderListSize == nil {
841 return true
842 }
843 var sz int64
844 for _, f := range hdr.hf {
845 if sz += int64(f.Size()); sz > int64(*t.maxSendHeaderListSize) {
846 hdrListSizeErr = status.Errorf(codes.Internal, "header list size to send violates the maximum size (%d bytes) set by server", *t.maxSendHeaderListSize)
847 return false
848 }
849 }
850 return true
851 }
852 for {
853 success, err := t.controlBuf.executeAndPut(func() bool {
854 return checkForHeaderListSize() && checkForStreamQuota()
855 }, hdr)
856 if err != nil {
857 // Connection closed.
858 return nil, &NewStreamError{Err: err, AllowTransparentRetry: true}
859 }
860 if success {
861 break
862 }
863 if hdrListSizeErr != nil {
864 return nil, &NewStreamError{Err: hdrListSizeErr}
865 }
866 firstTry = false
867 select {
868 case <-ch:
869 case <-ctx.Done():
870 return nil, &NewStreamError{Err: ContextErr(ctx.Err())}
871 case <-t.goAway:
872 return nil, &NewStreamError{Err: errStreamDrain, AllowTransparentRetry: true}
873 case <-t.ctx.Done():
874 return nil, &NewStreamError{Err: ErrConnClosing, AllowTransparentRetry: true}
875 }
876 }
877 if len(t.statsHandlers) != 0 {
878 header, ok := metadata.FromOutgoingContext(ctx)
879 if ok {
880 header.Set("user-agent", t.userAgent)
881 } else {
882 header = metadata.Pairs("user-agent", t.userAgent)
883 }
884 for _, sh := range t.statsHandlers {
885 // Note: The header fields are compressed with hpack after this call returns.
886 // No WireLength field is set here.
887 // Note: Creating a new stats object to prevent pollution.
888 outHeader := &stats.OutHeader{
889 Client: true,
890 FullMethod: callHdr.Method,
891 RemoteAddr: t.remoteAddr,
892 LocalAddr: t.localAddr,
893 Compression: callHdr.SendCompress,
894 Header: header,
895 }
896 sh.HandleRPC(s.ctx, outHeader)
897 }
898 }
899 if transportDrainRequired {
900 if t.logger.V(logLevel) {
901 t.logger.Infof("Draining transport: t.nextID > MaxStreamID")
902 }
903 t.GracefulClose()
904 }
905 return s, nil
906}
907
908func (t *http2Client) closeStream(s *ClientStream, err error, rst bool, rstCode http2.ErrCode, st *status.Status, mdata map[string][]string, eosReceived bool) {
909 // Set stream status to done.
910 if s.swapState(streamDone) == streamDone {
911 // If it was already done, return. If multiple closeStream calls
912 // happen simultaneously, wait for the first to finish.
913 <-s.done
914 return
915 }
916 // status and trailers can be updated here without any synchronization because the stream goroutine will
917 // only read it after it sees an io.EOF error from read or write and we'll write those errors
918 // only after updating this.
919 s.status = st
920 if len(mdata) > 0 {
921 s.trailer = mdata
922 }
923 if err != nil {
924 // This will unblock reads eventually.
925 s.write(recvMsg{err: err})
926 }
927 // If headerChan isn't closed, then close it.
928 if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
929 s.noHeaders = true
930 close(s.headerChan)
931 }
932 cleanup := &cleanupStream{
933 streamID: s.id,
934 onWrite: func() {
935 t.mu.Lock()
936 if t.activeStreams != nil {
937 delete(t.activeStreams, s.id)
938 }
939 t.mu.Unlock()
940 if channelz.IsOn() {
941 if eosReceived {
942 t.channelz.SocketMetrics.StreamsSucceeded.Add(1)
943 } else {
944 t.channelz.SocketMetrics.StreamsFailed.Add(1)
945 }
946 }
947 },
948 rst: rst,
949 rstCode: rstCode,
950 }
951 addBackStreamQuota := func() bool {
952 t.streamQuota++
953 if t.streamQuota > 0 && t.waitingStreams > 0 {
954 select {
955 case t.streamsQuotaAvailable <- struct{}{}:
956 default:
957 }
958 }
959 return true
960 }
961 t.controlBuf.executeAndPut(addBackStreamQuota, cleanup)
962 // This will unblock write.
963 close(s.done)
964 if s.doneFunc != nil {
965 s.doneFunc()
966 }
967}
968
969// Close kicks off the shutdown process of the transport. This should be called
970// only once on a transport. Once it is called, the transport should not be
971// accessed anymore.
972func (t *http2Client) Close(err error) {
973 t.conn.SetWriteDeadline(time.Now().Add(time.Second * 10))
974 t.mu.Lock()
975 // Make sure we only close once.
976 if t.state == closing {
977 t.mu.Unlock()
978 return
979 }
980 if t.logger.V(logLevel) {
981 t.logger.Infof("Closing: %v", err)
982 }
983 // Call t.onClose ASAP to prevent the client from attempting to create new
984 // streams.
985 if t.state != draining {
986 t.onClose(GoAwayInvalid)
987 }
988 t.state = closing
989 streams := t.activeStreams
990 t.activeStreams = nil
991 if t.kpDormant {
992 // If the keepalive goroutine is blocked on this condition variable, we
993 // should unblock it so that the goroutine eventually exits.
994 t.kpDormancyCond.Signal()
995 }
996 // Append info about previous goaways if there were any, since this may be important
997 // for understanding the root cause for this connection to be closed.
998 goAwayDebugMessage := t.goAwayDebugMessage
999 t.mu.Unlock()
1000
1001 // Per HTTP/2 spec, a GOAWAY frame must be sent before closing the
1002 // connection. See https://httpwg.org/specs/rfc7540.html#GOAWAY. It
1003 // also waits for loopyWriter to be closed with a timer to avoid the
1004 // long blocking in case the connection is blackholed, i.e. TCP is
1005 // just stuck.
1006 t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte("client transport shutdown"), closeConn: err})
1007 timer := time.NewTimer(goAwayLoopyWriterTimeout)
1008 defer timer.Stop()
1009 select {
1010 case <-t.writerDone: // success
1011 case <-timer.C:
1012 t.logger.Infof("Failed to write a GOAWAY frame as part of connection close after %s. Giving up and closing the transport.", goAwayLoopyWriterTimeout)
1013 }
1014 t.cancel()
1015 t.conn.Close()
1016 // Waits for the reader and keepalive goroutines to exit before returning to
1017 // ensure all resources are cleaned up before Close can return.
1018 <-t.readerDone
1019 if t.keepaliveEnabled {
1020 <-t.keepaliveDone
1021 }
1022 channelz.RemoveEntry(t.channelz.ID)
1023 var st *status.Status
1024 if len(goAwayDebugMessage) > 0 {
1025 st = status.Newf(codes.Unavailable, "closing transport due to: %v, received prior goaway: %v", err, goAwayDebugMessage)
1026 err = st.Err()
1027 } else {
1028 st = status.New(codes.Unavailable, err.Error())
1029 }
1030
1031 // Notify all active streams.
1032 for _, s := range streams {
1033 t.closeStream(s, err, false, http2.ErrCodeNo, st, nil, false)
1034 }
1035 for _, sh := range t.statsHandlers {
1036 connEnd := &stats.ConnEnd{
1037 Client: true,
1038 }
1039 sh.HandleConn(t.ctx, connEnd)
1040 }
1041}
1042
1043// GracefulClose sets the state to draining, which prevents new streams from
1044// being created and causes the transport to be closed when the last active
1045// stream is closed. If there are no active streams, the transport is closed
1046// immediately. This does nothing if the transport is already draining or
1047// closing.
1048func (t *http2Client) GracefulClose() {
1049 t.mu.Lock()
1050 // Make sure we move to draining only from active.
1051 if t.state == draining || t.state == closing {
1052 t.mu.Unlock()
1053 return
1054 }
1055 if t.logger.V(logLevel) {
1056 t.logger.Infof("GracefulClose called")
1057 }
1058 t.onClose(GoAwayInvalid)
1059 t.state = draining
1060 active := len(t.activeStreams)
1061 t.mu.Unlock()
1062 if active == 0 {
1063 t.Close(connectionErrorf(true, nil, "no active streams left to process while draining"))
1064 return
1065 }
1066 t.controlBuf.put(&incomingGoAway{})
1067}
1068
1069// Write formats the data into HTTP2 data frame(s) and sends it out. The caller
1070// should proceed only if Write returns nil.
1071func (t *http2Client) write(s *ClientStream, hdr []byte, data mem.BufferSlice, opts *WriteOptions) error {
1072 reader := data.Reader()
1073
1074 if opts.Last {
1075 // If it's the last message, update stream state.
1076 if !s.compareAndSwapState(streamActive, streamWriteDone) {
1077 _ = reader.Close()
1078 return errStreamDone
1079 }
1080 } else if s.getState() != streamActive {
1081 _ = reader.Close()
1082 return errStreamDone
1083 }
1084 df := &dataFrame{
1085 streamID: s.id,
1086 endStream: opts.Last,
1087 h: hdr,
1088 reader: reader,
1089 }
1090 if hdr != nil || df.reader.Remaining() != 0 { // If it's not an empty data frame, check quota.
1091 if err := s.wq.get(int32(len(hdr) + df.reader.Remaining())); err != nil {
1092 _ = reader.Close()
1093 return err
1094 }
1095 }
1096 if err := t.controlBuf.put(df); err != nil {
1097 _ = reader.Close()
1098 return err
1099 }
1100 t.incrMsgSent()
1101 return nil
1102}
1103
1104func (t *http2Client) getStream(f http2.Frame) *ClientStream {
1105 t.mu.Lock()
1106 s := t.activeStreams[f.Header().StreamID]
1107 t.mu.Unlock()
1108 return s
1109}
1110
1111// adjustWindow sends out extra window update over the initial window size
1112// of stream if the application is requesting data larger in size than
1113// the window.
1114func (t *http2Client) adjustWindow(s *ClientStream, n uint32) {
1115 if w := s.fc.maybeAdjust(n); w > 0 {
1116 t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
1117 }
1118}
1119
1120// updateWindow adjusts the inbound quota for the stream.
1121// Window updates will be sent out when the cumulative quota
1122// exceeds the corresponding threshold.
1123func (t *http2Client) updateWindow(s *ClientStream, n uint32) {
1124 if w := s.fc.onRead(n); w > 0 {
1125 t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
1126 }
1127}
1128
1129// updateFlowControl updates the incoming flow control windows
1130// for the transport and the stream based on the current bdp
1131// estimation.
1132func (t *http2Client) updateFlowControl(n uint32) {
1133 updateIWS := func() bool {
1134 t.initialWindowSize = int32(n)
1135 t.mu.Lock()
1136 for _, s := range t.activeStreams {
1137 s.fc.newLimit(n)
1138 }
1139 t.mu.Unlock()
1140 return true
1141 }
1142 t.controlBuf.executeAndPut(updateIWS, &outgoingWindowUpdate{streamID: 0, increment: t.fc.newLimit(n)})
1143 t.controlBuf.put(&outgoingSettings{
1144 ss: []http2.Setting{
1145 {
1146 ID: http2.SettingInitialWindowSize,
1147 Val: n,
1148 },
1149 },
1150 })
1151}
1152
1153func (t *http2Client) handleData(f *http2.DataFrame) {
1154 size := f.Header().Length
1155 var sendBDPPing bool
1156 if t.bdpEst != nil {
1157 sendBDPPing = t.bdpEst.add(size)
1158 }
1159 // Decouple connection's flow control from application's read.
1160 // An update on connection's flow control should not depend on
1161 // whether user application has read the data or not. Such a
1162 // restriction is already imposed on the stream's flow control,
1163 // and therefore the sender will be blocked anyways.
1164 // Decoupling the connection flow control will prevent other
1165 // active(fast) streams from starving in presence of slow or
1166 // inactive streams.
1167 //
1168 if w := t.fc.onData(size); w > 0 {
1169 t.controlBuf.put(&outgoingWindowUpdate{
1170 streamID: 0,
1171 increment: w,
1172 })
1173 }
1174 if sendBDPPing {
1175 // Avoid excessive ping detection (e.g. in an L7 proxy)
1176 // by sending a window update prior to the BDP ping.
1177
1178 if w := t.fc.reset(); w > 0 {
1179 t.controlBuf.put(&outgoingWindowUpdate{
1180 streamID: 0,
1181 increment: w,
1182 })
1183 }
1184
1185 t.controlBuf.put(bdpPing)
1186 }
1187 // Select the right stream to dispatch.
1188 s := t.getStream(f)
1189 if s == nil {
1190 return
1191 }
1192 if size > 0 {
1193 if err := s.fc.onData(size); err != nil {
1194 t.closeStream(s, io.EOF, true, http2.ErrCodeFlowControl, status.New(codes.Internal, err.Error()), nil, false)
1195 return
1196 }
1197 if f.Header().Flags.Has(http2.FlagDataPadded) {
1198 if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
1199 t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
1200 }
1201 }
1202 // TODO(bradfitz, zhaoq): A copy is required here because there is no
1203 // guarantee f.Data() is consumed before the arrival of next frame.
1204 // Can this copy be eliminated?
1205 if len(f.Data()) > 0 {
1206 pool := t.bufferPool
1207 if pool == nil {
1208 // Note that this is only supposed to be nil in tests. Otherwise, stream is
1209 // always initialized with a BufferPool.
1210 pool = mem.DefaultBufferPool()
1211 }
1212 s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
1213 }
1214 }
1215 // The server has closed the stream without sending trailers. Record that
1216 // the read direction is closed, and set the status appropriately.
1217 if f.StreamEnded() {
1218 t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.New(codes.Internal, "server closed the stream without sending trailers"), nil, true)
1219 }
1220}
1221
1222func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
1223 s := t.getStream(f)
1224 if s == nil {
1225 return
1226 }
1227 if f.ErrCode == http2.ErrCodeRefusedStream {
1228 // The stream was unprocessed by the server.
1229 s.unprocessed.Store(true)
1230 }
1231 statusCode, ok := http2ErrConvTab[f.ErrCode]
1232 if !ok {
1233 if t.logger.V(logLevel) {
1234 t.logger.Infof("Received a RST_STREAM frame with code %q, but found no mapped gRPC status", f.ErrCode)
1235 }
1236 statusCode = codes.Unknown
1237 }
1238 if statusCode == codes.Canceled {
1239 if d, ok := s.ctx.Deadline(); ok && !d.After(time.Now()) {
1240 // Our deadline was already exceeded, and that was likely the cause
1241 // of this cancellation. Alter the status code accordingly.
1242 statusCode = codes.DeadlineExceeded
1243 }
1244 }
1245 t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode), nil, false)
1246}
1247
1248func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
1249 if f.IsAck() {
1250 return
1251 }
1252 var maxStreams *uint32
1253 var ss []http2.Setting
1254 var updateFuncs []func()
1255 f.ForeachSetting(func(s http2.Setting) error {
1256 switch s.ID {
1257 case http2.SettingMaxConcurrentStreams:
1258 maxStreams = new(uint32)
1259 *maxStreams = s.Val
1260 case http2.SettingMaxHeaderListSize:
1261 updateFuncs = append(updateFuncs, func() {
1262 t.maxSendHeaderListSize = new(uint32)
1263 *t.maxSendHeaderListSize = s.Val
1264 })
1265 default:
1266 ss = append(ss, s)
1267 }
1268 return nil
1269 })
1270 if isFirst && maxStreams == nil {
1271 maxStreams = new(uint32)
1272 *maxStreams = math.MaxUint32
1273 }
1274 sf := &incomingSettings{
1275 ss: ss,
1276 }
1277 if maxStreams != nil {
1278 updateStreamQuota := func() {
1279 delta := int64(*maxStreams) - int64(t.maxConcurrentStreams)
1280 t.maxConcurrentStreams = *maxStreams
1281 t.streamQuota += delta
1282 if delta > 0 && t.waitingStreams > 0 {
1283 close(t.streamsQuotaAvailable) // wake all of them up.
1284 t.streamsQuotaAvailable = make(chan struct{}, 1)
1285 }
1286 }
1287 updateFuncs = append(updateFuncs, updateStreamQuota)
1288 }
1289 t.controlBuf.executeAndPut(func() bool {
1290 for _, f := range updateFuncs {
1291 f()
1292 }
1293 return true
1294 }, sf)
1295}
1296
1297func (t *http2Client) handlePing(f *http2.PingFrame) {
1298 if f.IsAck() {
1299 // Maybe it's a BDP ping.
1300 if t.bdpEst != nil {
1301 t.bdpEst.calculate(f.Data)
1302 }
1303 return
1304 }
1305 pingAck := &ping{ack: true}
1306 copy(pingAck.data[:], f.Data[:])
1307 t.controlBuf.put(pingAck)
1308}
1309
1310func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) error {
1311 t.mu.Lock()
1312 if t.state == closing {
1313 t.mu.Unlock()
1314 return nil
1315 }
1316 if f.ErrCode == http2.ErrCodeEnhanceYourCalm && string(f.DebugData()) == "too_many_pings" {
1317 // When a client receives a GOAWAY with error code ENHANCE_YOUR_CALM and debug
1318 // data equal to ASCII "too_many_pings", it should log the occurrence at a log level that is
1319 // enabled by default and double the configure KEEPALIVE_TIME used for new connections
1320 // on that channel.
1321 logger.Errorf("Client received GoAway with error code ENHANCE_YOUR_CALM and debug data equal to ASCII \"too_many_pings\".")
1322 }
1323 id := f.LastStreamID
1324 if id > 0 && id%2 == 0 {
1325 t.mu.Unlock()
1326 return connectionErrorf(true, nil, "received goaway with non-zero even-numbered stream id: %v", id)
1327 }
1328 // A client can receive multiple GoAways from the server (see
1329 // https://github.com/grpc/grpc-go/issues/1387). The idea is that the first
1330 // GoAway will be sent with an ID of MaxInt32 and the second GoAway will be
1331 // sent after an RTT delay with the ID of the last stream the server will
1332 // process.
1333 //
1334 // Therefore, when we get the first GoAway we don't necessarily close any
1335 // streams. While in case of second GoAway we close all streams created after
1336 // the GoAwayId. This way streams that were in-flight while the GoAway from
1337 // server was being sent don't get killed.
1338 select {
1339 case <-t.goAway: // t.goAway has been closed (i.e.,multiple GoAways).
1340 // If there are multiple GoAways the first one should always have an ID greater than the following ones.
1341 if id > t.prevGoAwayID {
1342 t.mu.Unlock()
1343 return connectionErrorf(true, nil, "received goaway with stream id: %v, which exceeds stream id of previous goaway: %v", id, t.prevGoAwayID)
1344 }
1345 default:
1346 t.setGoAwayReason(f)
1347 close(t.goAway)
1348 defer t.controlBuf.put(&incomingGoAway{}) // Defer as t.mu is currently held.
1349 // Notify the clientconn about the GOAWAY before we set the state to
1350 // draining, to allow the client to stop attempting to create streams
1351 // before disallowing new streams on this connection.
1352 if t.state != draining {
1353 t.onClose(t.goAwayReason)
1354 t.state = draining
1355 }
1356 }
1357 // All streams with IDs greater than the GoAwayId
1358 // and smaller than the previous GoAway ID should be killed.
1359 upperLimit := t.prevGoAwayID
1360 if upperLimit == 0 { // This is the first GoAway Frame.
1361 upperLimit = math.MaxUint32 // Kill all streams after the GoAway ID.
1362 }
1363
1364 t.prevGoAwayID = id
1365 if len(t.activeStreams) == 0 {
1366 t.mu.Unlock()
1367 return connectionErrorf(true, nil, "received goaway and there are no active streams")
1368 }
1369
1370 streamsToClose := make([]*ClientStream, 0)
1371 for streamID, stream := range t.activeStreams {
1372 if streamID > id && streamID <= upperLimit {
1373 // The stream was unprocessed by the server.
1374 stream.unprocessed.Store(true)
1375 streamsToClose = append(streamsToClose, stream)
1376 }
1377 }
1378 t.mu.Unlock()
1379 // Called outside t.mu because closeStream can take controlBuf's mu, which
1380 // could induce deadlock and is not allowed.
1381 for _, stream := range streamsToClose {
1382 t.closeStream(stream, errStreamDrain, false, http2.ErrCodeNo, statusGoAway, nil, false)
1383 }
1384 return nil
1385}
1386
1387// setGoAwayReason sets the value of t.goAwayReason based
1388// on the GoAway frame received.
1389// It expects a lock on transport's mutex to be held by
1390// the caller.
1391func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
1392 t.goAwayReason = GoAwayNoReason
1393 switch f.ErrCode {
1394 case http2.ErrCodeEnhanceYourCalm:
1395 if string(f.DebugData()) == "too_many_pings" {
1396 t.goAwayReason = GoAwayTooManyPings
1397 }
1398 }
1399 if len(f.DebugData()) == 0 {
1400 t.goAwayDebugMessage = fmt.Sprintf("code: %s", f.ErrCode)
1401 } else {
1402 t.goAwayDebugMessage = fmt.Sprintf("code: %s, debug data: %q", f.ErrCode, string(f.DebugData()))
1403 }
1404}
1405
1406func (t *http2Client) GetGoAwayReason() (GoAwayReason, string) {
1407 t.mu.Lock()
1408 defer t.mu.Unlock()
1409 return t.goAwayReason, t.goAwayDebugMessage
1410}
1411
1412func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) {
1413 t.controlBuf.put(&incomingWindowUpdate{
1414 streamID: f.Header().StreamID,
1415 increment: f.Increment,
1416 })
1417}
1418
1419// operateHeaders takes action on the decoded headers.
1420func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
1421 s := t.getStream(frame)
1422 if s == nil {
1423 return
1424 }
1425 endStream := frame.StreamEnded()
1426 s.bytesReceived.Store(true)
1427 initialHeader := atomic.LoadUint32(&s.headerChanClosed) == 0
1428
1429 if !initialHeader && !endStream {
1430 // As specified by gRPC over HTTP2, a HEADERS frame (and associated CONTINUATION frames) can only appear at the start or end of a stream. Therefore, second HEADERS frame must have EOS bit set.
1431 st := status.New(codes.Internal, "a HEADERS frame cannot appear in the middle of a stream")
1432 t.closeStream(s, st.Err(), true, http2.ErrCodeProtocol, st, nil, false)
1433 return
1434 }
1435
1436 // frame.Truncated is set to true when framer detects that the current header
1437 // list size hits MaxHeaderListSize limit.
1438 if frame.Truncated {
1439 se := status.New(codes.Internal, "peer header list size exceeded limit")
1440 t.closeStream(s, se.Err(), true, http2.ErrCodeFrameSize, se, nil, endStream)
1441 return
1442 }
1443
1444 var (
1445 // If a gRPC Response-Headers has already been received, then it means
1446 // that the peer is speaking gRPC and we are in gRPC mode.
1447 isGRPC = !initialHeader
1448 mdata = make(map[string][]string)
1449 contentTypeErr = "malformed header: missing HTTP content-type"
1450 grpcMessage string
1451 recvCompress string
1452 httpStatusCode *int
1453 httpStatusErr string
1454 rawStatusCode = codes.Unknown
1455 // headerError is set if an error is encountered while parsing the headers
1456 headerError string
1457 )
1458
1459 if initialHeader {
1460 httpStatusErr = "malformed header: missing HTTP status"
1461 }
1462
1463 for _, hf := range frame.Fields {
1464 switch hf.Name {
1465 case "content-type":
1466 if _, validContentType := grpcutil.ContentSubtype(hf.Value); !validContentType {
1467 contentTypeErr = fmt.Sprintf("transport: received unexpected content-type %q", hf.Value)
1468 break
1469 }
1470 contentTypeErr = ""
1471 mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
1472 isGRPC = true
1473 case "grpc-encoding":
1474 recvCompress = hf.Value
1475 case "grpc-status":
1476 code, err := strconv.ParseInt(hf.Value, 10, 32)
1477 if err != nil {
1478 se := status.New(codes.Internal, fmt.Sprintf("transport: malformed grpc-status: %v", err))
1479 t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
1480 return
1481 }
1482 rawStatusCode = codes.Code(uint32(code))
1483 case "grpc-message":
1484 grpcMessage = decodeGrpcMessage(hf.Value)
1485 case ":status":
1486 if hf.Value == "200" {
1487 httpStatusErr = ""
1488 statusCode := 200
1489 httpStatusCode = &statusCode
1490 break
1491 }
1492
1493 c, err := strconv.ParseInt(hf.Value, 10, 32)
1494 if err != nil {
1495 se := status.New(codes.Internal, fmt.Sprintf("transport: malformed http-status: %v", err))
1496 t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
1497 return
1498 }
1499 statusCode := int(c)
1500 httpStatusCode = &statusCode
1501
1502 httpStatusErr = fmt.Sprintf(
1503 "unexpected HTTP status code received from server: %d (%s)",
1504 statusCode,
1505 http.StatusText(statusCode),
1506 )
1507 default:
1508 if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
1509 break
1510 }
1511 v, err := decodeMetadataHeader(hf.Name, hf.Value)
1512 if err != nil {
1513 headerError = fmt.Sprintf("transport: malformed %s: %v", hf.Name, err)
1514 logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
1515 break
1516 }
1517 mdata[hf.Name] = append(mdata[hf.Name], v)
1518 }
1519 }
1520
1521 if !isGRPC || httpStatusErr != "" {
1522 var code = codes.Internal // when header does not include HTTP status, return INTERNAL
1523
1524 if httpStatusCode != nil {
1525 var ok bool
1526 code, ok = HTTPStatusConvTab[*httpStatusCode]
1527 if !ok {
1528 code = codes.Unknown
1529 }
1530 }
1531 var errs []string
1532 if httpStatusErr != "" {
1533 errs = append(errs, httpStatusErr)
1534 }
1535 if contentTypeErr != "" {
1536 errs = append(errs, contentTypeErr)
1537 }
1538 // Verify the HTTP response is a 200.
1539 se := status.New(code, strings.Join(errs, "; "))
1540 t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
1541 return
1542 }
1543
1544 if headerError != "" {
1545 se := status.New(codes.Internal, headerError)
1546 t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
1547 return
1548 }
1549
1550 // For headers, set them in s.header and close headerChan. For trailers or
1551 // trailers-only, closeStream will set the trailers and close headerChan as
1552 // needed.
1553 if !endStream {
1554 // If headerChan hasn't been closed yet (expected, given we checked it
1555 // above, but something else could have potentially closed the whole
1556 // stream).
1557 if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
1558 s.headerValid = true
1559 // These values can be set without any synchronization because
1560 // stream goroutine will read it only after seeing a closed
1561 // headerChan which we'll close after setting this.
1562 s.recvCompress = recvCompress
1563 if len(mdata) > 0 {
1564 s.header = mdata
1565 }
1566 close(s.headerChan)
1567 }
1568 }
1569
1570 for _, sh := range t.statsHandlers {
1571 if !endStream {
1572 inHeader := &stats.InHeader{
1573 Client: true,
1574 WireLength: int(frame.Header().Length),
1575 Header: metadata.MD(mdata).Copy(),
1576 Compression: s.recvCompress,
1577 }
1578 sh.HandleRPC(s.ctx, inHeader)
1579 } else {
1580 inTrailer := &stats.InTrailer{
1581 Client: true,
1582 WireLength: int(frame.Header().Length),
1583 Trailer: metadata.MD(mdata).Copy(),
1584 }
1585 sh.HandleRPC(s.ctx, inTrailer)
1586 }
1587 }
1588
1589 if !endStream {
1590 return
1591 }
1592
1593 status := istatus.NewWithProto(rawStatusCode, grpcMessage, mdata[grpcStatusDetailsBinHeader])
1594
1595 // If client received END_STREAM from server while stream was still active,
1596 // send RST_STREAM.
1597 rstStream := s.getState() == streamActive
1598 t.closeStream(s, io.EOF, rstStream, http2.ErrCodeNo, status, mdata, true)
1599}
1600
1601// readServerPreface reads and handles the initial settings frame from the
1602// server.
1603func (t *http2Client) readServerPreface() error {
1604 frame, err := t.framer.fr.ReadFrame()
1605 if err != nil {
1606 return connectionErrorf(true, err, "error reading server preface: %v", err)
1607 }
1608 sf, ok := frame.(*http2.SettingsFrame)
1609 if !ok {
1610 return connectionErrorf(true, nil, "initial http2 frame from server is not a settings frame: %T", frame)
1611 }
1612 t.handleSettings(sf, true)
1613 return nil
1614}
1615
1616// reader verifies the server preface and reads all subsequent data from
1617// network connection. If the server preface is not read successfully, an
1618// error is pushed to errCh; otherwise errCh is closed with no error.
1619func (t *http2Client) reader(errCh chan<- error) {
1620 var errClose error
1621 defer func() {
1622 close(t.readerDone)
1623 if errClose != nil {
1624 t.Close(errClose)
1625 }
1626 }()
1627
1628 if err := t.readServerPreface(); err != nil {
1629 errCh <- err
1630 return
1631 }
1632 close(errCh)
1633 if t.keepaliveEnabled {
1634 atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
1635 }
1636
1637 // loop to keep reading incoming messages on this transport.
1638 for {
1639 t.controlBuf.throttle()
1640 frame, err := t.framer.fr.ReadFrame()
1641 if t.keepaliveEnabled {
1642 atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
1643 }
1644 if err != nil {
1645 // Abort an active stream if the http2.Framer returns a
1646 // http2.StreamError. This can happen only if the server's response
1647 // is malformed http2.
1648 if se, ok := err.(http2.StreamError); ok {
1649 t.mu.Lock()
1650 s := t.activeStreams[se.StreamID]
1651 t.mu.Unlock()
1652 if s != nil {
1653 // use error detail to provide better err message
1654 code := http2ErrConvTab[se.Code]
1655 errorDetail := t.framer.fr.ErrorDetail()
1656 var msg string
1657 if errorDetail != nil {
1658 msg = errorDetail.Error()
1659 } else {
1660 msg = "received invalid frame"
1661 }
1662 t.closeStream(s, status.Error(code, msg), true, http2.ErrCodeProtocol, status.New(code, msg), nil, false)
1663 }
1664 continue
1665 }
1666 // Transport error.
1667 errClose = connectionErrorf(true, err, "error reading from server: %v", err)
1668 return
1669 }
1670 switch frame := frame.(type) {
1671 case *http2.MetaHeadersFrame:
1672 t.operateHeaders(frame)
1673 case *http2.DataFrame:
1674 t.handleData(frame)
1675 case *http2.RSTStreamFrame:
1676 t.handleRSTStream(frame)
1677 case *http2.SettingsFrame:
1678 t.handleSettings(frame, false)
1679 case *http2.PingFrame:
1680 t.handlePing(frame)
1681 case *http2.GoAwayFrame:
1682 errClose = t.handleGoAway(frame)
1683 case *http2.WindowUpdateFrame:
1684 t.handleWindowUpdate(frame)
1685 default:
1686 if logger.V(logLevel) {
1687 logger.Errorf("transport: http2Client.reader got unhandled frame type %v.", frame)
1688 }
1689 }
1690 }
1691}
1692
1693// keepalive running in a separate goroutine makes sure the connection is alive by sending pings.
1694func (t *http2Client) keepalive() {
1695 var err error
1696 defer func() {
1697 close(t.keepaliveDone)
1698 if err != nil {
1699 t.Close(err)
1700 }
1701 }()
1702 p := &ping{data: [8]byte{}}
1703 // True iff a ping has been sent, and no data has been received since then.
1704 outstandingPing := false
1705 // Amount of time remaining before which we should receive an ACK for the
1706 // last sent ping.
1707 timeoutLeft := time.Duration(0)
1708 // Records the last value of t.lastRead before we go block on the timer.
1709 // This is required to check for read activity since then.
1710 prevNano := time.Now().UnixNano()
1711 timer := time.NewTimer(t.kp.Time)
1712 for {
1713 select {
1714 case <-timer.C:
1715 lastRead := atomic.LoadInt64(&t.lastRead)
1716 if lastRead > prevNano {
1717 // There has been read activity since the last time we were here.
1718 outstandingPing = false
1719 // Next timer should fire at kp.Time seconds from lastRead time.
1720 timer.Reset(time.Duration(lastRead) + t.kp.Time - time.Duration(time.Now().UnixNano()))
1721 prevNano = lastRead
1722 continue
1723 }
1724 if outstandingPing && timeoutLeft <= 0 {
1725 err = connectionErrorf(true, nil, "keepalive ping failed to receive ACK within timeout")
1726 return
1727 }
1728 t.mu.Lock()
1729 if t.state == closing {
1730 // If the transport is closing, we should exit from the
1731 // keepalive goroutine here. If not, we could have a race
1732 // between the call to Signal() from Close() and the call to
1733 // Wait() here, whereby the keepalive goroutine ends up
1734 // blocking on the condition variable which will never be
1735 // signalled again.
1736 t.mu.Unlock()
1737 return
1738 }
1739 if len(t.activeStreams) < 1 && !t.kp.PermitWithoutStream {
1740 // If a ping was sent out previously (because there were active
1741 // streams at that point) which wasn't acked and its timeout
1742 // hadn't fired, but we got here and are about to go dormant,
1743 // we should make sure that we unconditionally send a ping once
1744 // we awaken.
1745 outstandingPing = false
1746 t.kpDormant = true
1747 t.kpDormancyCond.Wait()
1748 }
1749 t.kpDormant = false
1750 t.mu.Unlock()
1751
1752 // We get here either because we were dormant and a new stream was
1753 // created which unblocked the Wait() call, or because the
1754 // keepalive timer expired. In both cases, we need to send a ping.
1755 if !outstandingPing {
1756 if channelz.IsOn() {
1757 t.channelz.SocketMetrics.KeepAlivesSent.Add(1)
1758 }
1759 t.controlBuf.put(p)
1760 timeoutLeft = t.kp.Timeout
1761 outstandingPing = true
1762 }
1763 // The amount of time to sleep here is the minimum of kp.Time and
1764 // timeoutLeft. This will ensure that we wait only for kp.Time
1765 // before sending out the next ping (for cases where the ping is
1766 // acked).
1767 sleepDuration := min(t.kp.Time, timeoutLeft)
1768 timeoutLeft -= sleepDuration
1769 timer.Reset(sleepDuration)
1770 case <-t.ctx.Done():
1771 if !timer.Stop() {
1772 <-timer.C
1773 }
1774 return
1775 }
1776 }
1777}
1778
1779func (t *http2Client) Error() <-chan struct{} {
1780 return t.ctx.Done()
1781}
1782
1783func (t *http2Client) GoAway() <-chan struct{} {
1784 return t.goAway
1785}
1786
1787func (t *http2Client) socketMetrics() *channelz.EphemeralSocketMetrics {
1788 return &channelz.EphemeralSocketMetrics{
1789 LocalFlowControlWindow: int64(t.fc.getSize()),
1790 RemoteFlowControlWindow: t.getOutFlowWindow(),
1791 }
1792}
1793
1794func (t *http2Client) RemoteAddr() net.Addr { return t.remoteAddr }
1795
1796func (t *http2Client) incrMsgSent() {
1797 if channelz.IsOn() {
1798 t.channelz.SocketMetrics.MessagesSent.Add(1)
1799 t.channelz.SocketMetrics.LastMessageSentTimestamp.Store(time.Now().UnixNano())
1800 }
1801}
1802
1803func (t *http2Client) incrMsgRecv() {
1804 if channelz.IsOn() {
1805 t.channelz.SocketMetrics.MessagesReceived.Add(1)
1806 t.channelz.SocketMetrics.LastMessageReceivedTimestamp.Store(time.Now().UnixNano())
1807 }
1808}
1809
1810func (t *http2Client) getOutFlowWindow() int64 {
1811 resp := make(chan uint32, 1)
1812 timer := time.NewTimer(time.Second)
1813 defer timer.Stop()
1814 t.controlBuf.put(&outFlowControlSizeRequest{resp})
1815 select {
1816 case sz := <-resp:
1817 return int64(sz)
1818 case <-t.ctxDone:
1819 return -1
1820 case <-timer.C:
1821 return -2
1822 }
1823}
1824
1825func (t *http2Client) stateForTesting() transportState {
1826 t.mu.Lock()
1827 defer t.mu.Unlock()
1828 return t.state
1829}