github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/net/http2/transport.go (about) 1 // Copyright 2015 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Transport code. 6 7 package http2 8 9 import ( 10 "bufio" 11 "bytes" 12 "compress/gzip" 13 "crypto/tls" 14 "errors" 15 "fmt" 16 "io" 17 "io/ioutil" 18 "log" 19 "net" 20 "net/http" 21 "sort" 22 "strconv" 23 "strings" 24 "sync" 25 26 "golang.org/x/net/http2/hpack" 27 ) 28 29 const ( 30 // transportDefaultConnFlow is how many connection-level flow control 31 // tokens we give the server at start-up, past the default 64k. 32 transportDefaultConnFlow = 1 << 30 33 34 // transportDefaultStreamFlow is how many stream-level flow 35 // control tokens we announce to the peer, and how many bytes 36 // we buffer per stream. 37 transportDefaultStreamFlow = 4 << 20 38 39 // transportDefaultStreamMinRefresh is the minimum number of bytes we'll send 40 // a stream-level WINDOW_UPDATE for at a time. 41 transportDefaultStreamMinRefresh = 4 << 10 42 43 defaultUserAgent = "Go-http-client/2.0" 44 ) 45 46 // Transport is an HTTP/2 Transport. 47 // 48 // A Transport internally caches connections to servers. It is safe 49 // for concurrent use by multiple goroutines. 50 type Transport struct { 51 // DialTLS specifies an optional dial function for creating 52 // TLS connections for requests. 53 // 54 // If DialTLS is nil, tls.Dial is used. 55 // 56 // If the returned net.Conn has a ConnectionState method like tls.Conn, 57 // it will be used to set http.Response.TLS. 58 DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error) 59 60 // TLSClientConfig specifies the TLS configuration to use with 61 // tls.Client. If nil, the default configuration is used. 62 TLSClientConfig *tls.Config 63 64 // ConnPool optionally specifies an alternate connection pool to use. 65 // If nil, the default is used. 66 ConnPool ClientConnPool 67 68 // DisableCompression, if true, prevents the Transport from 69 // requesting compression with an "Accept-Encoding: gzip" 70 // request header when the Request contains no existing 71 // Accept-Encoding value. If the Transport requests gzip on 72 // its own and gets a gzipped response, it's transparently 73 // decoded in the Response.Body. However, if the user 74 // explicitly requested gzip it is not automatically 75 // uncompressed. 76 DisableCompression bool 77 78 connPoolOnce sync.Once 79 connPoolOrDef ClientConnPool // non-nil version of ConnPool 80 } 81 82 func (t *Transport) disableCompression() bool { 83 if t.DisableCompression { 84 return true 85 } 86 // TODO: also disable if this transport is somehow linked to an http1 Transport 87 // and it's configured there? 88 return false 89 } 90 91 var errTransportVersion = errors.New("http2: ConfigureTransport is only supported starting at Go 1.6") 92 93 // ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2. 94 // It requires Go 1.6 or later and returns an error if the net/http package is too old 95 // or if t1 has already been HTTP/2-enabled. 96 func ConfigureTransport(t1 *http.Transport) error { 97 return configureTransport(t1) // in configure_transport.go (go1.6) or go15.go 98 } 99 100 func (t *Transport) connPool() ClientConnPool { 101 t.connPoolOnce.Do(t.initConnPool) 102 return t.connPoolOrDef 103 } 104 105 func (t *Transport) initConnPool() { 106 if t.ConnPool != nil { 107 t.connPoolOrDef = t.ConnPool 108 } else { 109 t.connPoolOrDef = &clientConnPool{t: t} 110 } 111 } 112 113 // ClientConn is the state of a single HTTP/2 client connection to an 114 // HTTP/2 server. 115 type ClientConn struct { 116 t *Transport 117 tconn net.Conn // usually *tls.Conn, except specialized impls 118 tlsState *tls.ConnectionState // nil only for specialized impls 119 120 // readLoop goroutine fields: 121 readerDone chan struct{} // closed on error 122 readerErr error // set before readerDone is closed 123 124 mu sync.Mutex // guards following 125 cond *sync.Cond // hold mu; broadcast on flow/closed changes 126 flow flow // our conn-level flow control quota (cs.flow is per stream) 127 inflow flow // peer's conn-level flow control 128 closed bool 129 goAway *GoAwayFrame // if non-nil, the GoAwayFrame we received 130 streams map[uint32]*clientStream // client-initiated 131 nextStreamID uint32 132 bw *bufio.Writer 133 br *bufio.Reader 134 fr *Framer 135 // Settings from peer: 136 maxFrameSize uint32 137 maxConcurrentStreams uint32 138 initialWindowSize uint32 139 hbuf bytes.Buffer // HPACK encoder writes into this 140 henc *hpack.Encoder 141 freeBuf [][]byte 142 143 wmu sync.Mutex // held while writing; acquire AFTER wmu if holding both 144 werr error // first write error that has occurred 145 } 146 147 // clientStream is the state for a single HTTP/2 stream. One of these 148 // is created for each Transport.RoundTrip call. 149 type clientStream struct { 150 cc *ClientConn 151 req *http.Request 152 ID uint32 153 resc chan resAndError 154 bufPipe pipe // buffered pipe with the flow-controlled response payload 155 requestedGzip bool 156 157 flow flow // guarded by cc.mu 158 inflow flow // guarded by cc.mu 159 bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read 160 readErr error // sticky read error; owned by transportResponseBody.Read 161 stopReqBody bool // stop writing req body; guarded by cc.mu 162 163 peerReset chan struct{} // closed on peer reset 164 resetErr error // populated before peerReset is closed 165 166 done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu 167 168 // owned by clientConnReadLoop: 169 headersDone bool // got HEADERS w/ END_HEADERS 170 trailersDone bool // got second HEADERS frame w/ END_HEADERS 171 172 trailer http.Header // accumulated trailers 173 resTrailer http.Header // client's Response.Trailer 174 } 175 176 // awaitRequestCancel runs in its own goroutine and waits for the user 177 // to either cancel a RoundTrip request (using the provided 178 // Request.Cancel channel), or for the request to be done (any way it 179 // might be removed from the cc.streams map: peer reset, successful 180 // completion, TCP connection breakage, etc) 181 func (cs *clientStream) awaitRequestCancel(cancel <-chan struct{}) { 182 if cancel == nil { 183 return 184 } 185 select { 186 case <-cancel: 187 cs.bufPipe.CloseWithError(errRequestCanceled) 188 cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) 189 case <-cs.done: 190 } 191 } 192 193 // checkReset reports any error sent in a RST_STREAM frame by the 194 // server. 195 func (cs *clientStream) checkReset() error { 196 select { 197 case <-cs.peerReset: 198 return cs.resetErr 199 default: 200 return nil 201 } 202 } 203 204 func (cs *clientStream) abortRequestBodyWrite() { 205 cc := cs.cc 206 cc.mu.Lock() 207 cs.stopReqBody = true 208 cc.cond.Broadcast() 209 cc.mu.Unlock() 210 } 211 212 type stickyErrWriter struct { 213 w io.Writer 214 err *error 215 } 216 217 func (sew stickyErrWriter) Write(p []byte) (n int, err error) { 218 if *sew.err != nil { 219 return 0, *sew.err 220 } 221 n, err = sew.w.Write(p) 222 *sew.err = err 223 return 224 } 225 226 var ErrNoCachedConn = errors.New("http2: no cached connection was available") 227 228 // RoundTripOpt are options for the Transport.RoundTripOpt method. 229 type RoundTripOpt struct { 230 // OnlyCachedConn controls whether RoundTripOpt may 231 // create a new TCP connection. If set true and 232 // no cached connection is available, RoundTripOpt 233 // will return ErrNoCachedConn. 234 OnlyCachedConn bool 235 } 236 237 func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) { 238 return t.RoundTripOpt(req, RoundTripOpt{}) 239 } 240 241 // authorityAddr returns a given authority (a host/IP, or host:port / ip:port) 242 // and returns a host:port. The port 443 is added if needed. 243 func authorityAddr(authority string) (addr string) { 244 if _, _, err := net.SplitHostPort(authority); err == nil { 245 return authority 246 } 247 return net.JoinHostPort(authority, "443") 248 } 249 250 // RoundTripOpt is like RoundTrip, but takes options. 251 func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) { 252 if req.URL.Scheme != "https" { 253 return nil, errors.New("http2: unsupported scheme") 254 } 255 256 addr := authorityAddr(req.URL.Host) 257 for { 258 cc, err := t.connPool().GetClientConn(req, addr) 259 if err != nil { 260 t.vlogf("failed to get client conn: %v", err) 261 return nil, err 262 } 263 res, err := cc.RoundTrip(req) 264 if shouldRetryRequest(req, err) { 265 continue 266 } 267 if err != nil { 268 t.vlogf("RoundTrip failure: %v", err) 269 return nil, err 270 } 271 return res, nil 272 } 273 } 274 275 // CloseIdleConnections closes any connections which were previously 276 // connected from previous requests but are now sitting idle. 277 // It does not interrupt any connections currently in use. 278 func (t *Transport) CloseIdleConnections() { 279 if cp, ok := t.connPool().(*clientConnPool); ok { 280 cp.closeIdleConnections() 281 } 282 } 283 284 var ( 285 errClientConnClosed = errors.New("http2: client conn is closed") 286 errClientConnUnusable = errors.New("http2: client conn not usable") 287 ) 288 289 func shouldRetryRequest(req *http.Request, err error) bool { 290 // TODO: retry GET requests (no bodies) more aggressively, if shutdown 291 // before response. 292 return err == errClientConnUnusable 293 } 294 295 func (t *Transport) dialClientConn(addr string) (*ClientConn, error) { 296 host, _, err := net.SplitHostPort(addr) 297 if err != nil { 298 return nil, err 299 } 300 tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host)) 301 if err != nil { 302 return nil, err 303 } 304 return t.NewClientConn(tconn) 305 } 306 307 func (t *Transport) newTLSConfig(host string) *tls.Config { 308 cfg := new(tls.Config) 309 if t.TLSClientConfig != nil { 310 *cfg = *t.TLSClientConfig 311 } 312 cfg.NextProtos = []string{NextProtoTLS} // TODO: don't override if already in list 313 cfg.ServerName = host 314 return cfg 315 } 316 317 func (t *Transport) dialTLS() func(string, string, *tls.Config) (net.Conn, error) { 318 if t.DialTLS != nil { 319 return t.DialTLS 320 } 321 return t.dialTLSDefault 322 } 323 324 func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) { 325 cn, err := tls.Dial(network, addr, cfg) 326 if err != nil { 327 return nil, err 328 } 329 if err := cn.Handshake(); err != nil { 330 return nil, err 331 } 332 if !cfg.InsecureSkipVerify { 333 if err := cn.VerifyHostname(cfg.ServerName); err != nil { 334 return nil, err 335 } 336 } 337 state := cn.ConnectionState() 338 if p := state.NegotiatedProtocol; p != NextProtoTLS { 339 return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS) 340 } 341 if !state.NegotiatedProtocolIsMutual { 342 return nil, errors.New("http2: could not negotiate protocol mutually") 343 } 344 return cn, nil 345 } 346 347 func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) { 348 if VerboseLogs { 349 t.vlogf("creating client conn to %v", c.RemoteAddr()) 350 } 351 if _, err := c.Write(clientPreface); err != nil { 352 t.vlogf("client preface write error: %v", err) 353 return nil, err 354 } 355 356 cc := &ClientConn{ 357 t: t, 358 tconn: c, 359 readerDone: make(chan struct{}), 360 nextStreamID: 1, 361 maxFrameSize: 16 << 10, // spec default 362 initialWindowSize: 65535, // spec default 363 maxConcurrentStreams: 1000, // "infinite", per spec. 1000 seems good enough. 364 streams: make(map[uint32]*clientStream), 365 } 366 cc.cond = sync.NewCond(&cc.mu) 367 cc.flow.add(int32(initialWindowSize)) 368 369 // TODO: adjust this writer size to account for frame size + 370 // MTU + crypto/tls record padding. 371 cc.bw = bufio.NewWriter(stickyErrWriter{c, &cc.werr}) 372 cc.br = bufio.NewReader(c) 373 cc.fr = NewFramer(cc.bw, cc.br) 374 cc.henc = hpack.NewEncoder(&cc.hbuf) 375 376 type connectionStater interface { 377 ConnectionState() tls.ConnectionState 378 } 379 if cs, ok := c.(connectionStater); ok { 380 state := cs.ConnectionState() 381 cc.tlsState = &state 382 } 383 384 cc.fr.WriteSettings( 385 Setting{ID: SettingEnablePush, Val: 0}, 386 Setting{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow}, 387 ) 388 cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow) 389 cc.inflow.add(transportDefaultConnFlow + initialWindowSize) 390 cc.bw.Flush() 391 if cc.werr != nil { 392 return nil, cc.werr 393 } 394 395 // Read the obligatory SETTINGS frame 396 f, err := cc.fr.ReadFrame() 397 if err != nil { 398 return nil, err 399 } 400 sf, ok := f.(*SettingsFrame) 401 if !ok { 402 return nil, fmt.Errorf("expected settings frame, got: %T", f) 403 } 404 cc.fr.WriteSettingsAck() 405 cc.bw.Flush() 406 407 sf.ForeachSetting(func(s Setting) error { 408 switch s.ID { 409 case SettingMaxFrameSize: 410 cc.maxFrameSize = s.Val 411 case SettingMaxConcurrentStreams: 412 cc.maxConcurrentStreams = s.Val 413 case SettingInitialWindowSize: 414 cc.initialWindowSize = s.Val 415 default: 416 // TODO(bradfitz): handle more 417 t.vlogf("Unhandled Setting: %v", s) 418 } 419 return nil 420 }) 421 422 go cc.readLoop() 423 return cc, nil 424 } 425 426 func (cc *ClientConn) setGoAway(f *GoAwayFrame) { 427 cc.mu.Lock() 428 defer cc.mu.Unlock() 429 cc.goAway = f 430 } 431 432 func (cc *ClientConn) CanTakeNewRequest() bool { 433 cc.mu.Lock() 434 defer cc.mu.Unlock() 435 return cc.canTakeNewRequestLocked() 436 } 437 438 func (cc *ClientConn) canTakeNewRequestLocked() bool { 439 return cc.goAway == nil && 440 int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams) && 441 cc.nextStreamID < 2147483647 442 } 443 444 func (cc *ClientConn) closeIfIdle() { 445 cc.mu.Lock() 446 if len(cc.streams) > 0 { 447 cc.mu.Unlock() 448 return 449 } 450 cc.closed = true 451 // TODO: do clients send GOAWAY too? maybe? Just Close: 452 cc.mu.Unlock() 453 454 cc.tconn.Close() 455 } 456 457 const maxAllocFrameSize = 512 << 10 458 459 // frameBuffer returns a scratch buffer suitable for writing DATA frames. 460 // They're capped at the min of the peer's max frame size or 512KB 461 // (kinda arbitrarily), but definitely capped so we don't allocate 4GB 462 // bufers. 463 func (cc *ClientConn) frameScratchBuffer() []byte { 464 cc.mu.Lock() 465 size := cc.maxFrameSize 466 if size > maxAllocFrameSize { 467 size = maxAllocFrameSize 468 } 469 for i, buf := range cc.freeBuf { 470 if len(buf) >= int(size) { 471 cc.freeBuf[i] = nil 472 cc.mu.Unlock() 473 return buf[:size] 474 } 475 } 476 cc.mu.Unlock() 477 return make([]byte, size) 478 } 479 480 func (cc *ClientConn) putFrameScratchBuffer(buf []byte) { 481 cc.mu.Lock() 482 defer cc.mu.Unlock() 483 const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate. 484 if len(cc.freeBuf) < maxBufs { 485 cc.freeBuf = append(cc.freeBuf, buf) 486 return 487 } 488 for i, old := range cc.freeBuf { 489 if old == nil { 490 cc.freeBuf[i] = buf 491 return 492 } 493 } 494 // forget about it. 495 } 496 497 // errRequestCanceled is a copy of net/http's errRequestCanceled because it's not 498 // exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests. 499 var errRequestCanceled = errors.New("net/http: request canceled") 500 501 func commaSeparatedTrailers(req *http.Request) (string, error) { 502 keys := make([]string, 0, len(req.Trailer)) 503 for k := range req.Trailer { 504 k = http.CanonicalHeaderKey(k) 505 switch k { 506 case "Transfer-Encoding", "Trailer", "Content-Length": 507 return "", &badStringError{"invalid Trailer key", k} 508 } 509 keys = append(keys, k) 510 } 511 if len(keys) > 0 { 512 sort.Strings(keys) 513 // TODO: could do better allocation-wise here, but trailers are rare, 514 // so being lazy for now. 515 return strings.Join(keys, ","), nil 516 } 517 return "", nil 518 } 519 520 func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) { 521 trailers, err := commaSeparatedTrailers(req) 522 if err != nil { 523 return nil, err 524 } 525 hasTrailers := trailers != "" 526 527 cc.mu.Lock() 528 if cc.closed || !cc.canTakeNewRequestLocked() { 529 cc.mu.Unlock() 530 return nil, errClientConnUnusable 531 } 532 533 cs := cc.newStream() 534 cs.req = req 535 hasBody := req.Body != nil 536 537 // TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere? 538 if !cc.t.disableCompression() && 539 req.Header.Get("Accept-Encoding") == "" && 540 req.Header.Get("Range") == "" && 541 req.Method != "HEAD" { 542 // Request gzip only, not deflate. Deflate is ambiguous and 543 // not as universally supported anyway. 544 // See: http://www.gzip.org/zlib/zlib_faq.html#faq38 545 // 546 // Note that we don't request this for HEAD requests, 547 // due to a bug in nginx: 548 // http://trac.nginx.org/nginx/ticket/358 549 // https://golang.org/issue/5522 550 // 551 // We don't request gzip if the request is for a range, since 552 // auto-decoding a portion of a gzipped document will just fail 553 // anyway. See https://golang.org/issue/8923 554 cs.requestedGzip = true 555 } 556 557 // we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is 558 // sent by writeRequestBody below, along with any Trailers, 559 // again in form HEADERS{1}, CONTINUATION{0,}) 560 hdrs := cc.encodeHeaders(req, cs.requestedGzip, trailers) 561 cc.wmu.Lock() 562 endStream := !hasBody && !hasTrailers 563 werr := cc.writeHeaders(cs.ID, endStream, hdrs) 564 cc.wmu.Unlock() 565 cc.mu.Unlock() 566 567 if werr != nil { 568 if hasBody { 569 req.Body.Close() // per RoundTripper contract 570 } 571 cc.forgetStreamID(cs.ID) 572 // Don't bother sending a RST_STREAM (our write already failed; 573 // no need to keep writing) 574 return nil, werr 575 } 576 577 var bodyCopyErrc chan error // result of body copy 578 if hasBody { 579 bodyCopyErrc = make(chan error, 1) 580 go func() { 581 bodyCopyErrc <- cs.writeRequestBody(req.Body) 582 }() 583 } 584 585 readLoopResCh := cs.resc 586 requestCanceledCh := requestCancel(req) 587 requestCanceled := false 588 for { 589 select { 590 case re := <-readLoopResCh: 591 res := re.res 592 if re.err != nil || res.StatusCode > 299 { 593 // On error or status code 3xx, 4xx, 5xx, etc abort any 594 // ongoing write, assuming that the server doesn't care 595 // about our request body. If the server replied with 1xx or 596 // 2xx, however, then assume the server DOES potentially 597 // want our body (e.g. full-duplex streaming: 598 // golang.org/issue/13444). If it turns out the server 599 // doesn't, they'll RST_STREAM us soon enough. This is a 600 // heuristic to avoid adding knobs to Transport. Hopefully 601 // we can keep it. 602 cs.abortRequestBodyWrite() 603 } 604 if re.err != nil { 605 cc.forgetStreamID(cs.ID) 606 return nil, re.err 607 } 608 res.Request = req 609 res.TLS = cc.tlsState 610 return res, nil 611 case <-requestCanceledCh: 612 cc.forgetStreamID(cs.ID) 613 cs.abortRequestBodyWrite() 614 if !hasBody { 615 cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) 616 return nil, errRequestCanceled 617 } 618 // If we have a body, wait for the body write to be 619 // finished before sending the RST_STREAM frame. 620 requestCanceled = true 621 requestCanceledCh = nil // to prevent spins 622 readLoopResCh = nil // ignore responses at this point 623 case <-cs.peerReset: 624 if requestCanceled { 625 // They hung up on us first. No need to write a RST_STREAM. 626 // But prioritize the request canceled error value, since 627 // it's likely related. (same spirit as http1 code) 628 return nil, errRequestCanceled 629 } 630 // processResetStream already removed the 631 // stream from the streams map; no need for 632 // forgetStreamID. 633 return nil, cs.resetErr 634 case err := <-bodyCopyErrc: 635 if requestCanceled { 636 cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) 637 return nil, errRequestCanceled 638 } 639 if err != nil { 640 return nil, err 641 } 642 } 643 } 644 } 645 646 // requires cc.wmu be held 647 func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, hdrs []byte) error { 648 first := true // first frame written (HEADERS is first, then CONTINUATION) 649 frameSize := int(cc.maxFrameSize) 650 for len(hdrs) > 0 && cc.werr == nil { 651 chunk := hdrs 652 if len(chunk) > frameSize { 653 chunk = chunk[:frameSize] 654 } 655 hdrs = hdrs[len(chunk):] 656 endHeaders := len(hdrs) == 0 657 if first { 658 cc.fr.WriteHeaders(HeadersFrameParam{ 659 StreamID: streamID, 660 BlockFragment: chunk, 661 EndStream: endStream, 662 EndHeaders: endHeaders, 663 }) 664 first = false 665 } else { 666 cc.fr.WriteContinuation(streamID, endHeaders, chunk) 667 } 668 } 669 // TODO(bradfitz): this Flush could potentially block (as 670 // could the WriteHeaders call(s) above), which means they 671 // wouldn't respond to Request.Cancel being readable. That's 672 // rare, but this should probably be in a goroutine. 673 cc.bw.Flush() 674 return cc.werr 675 } 676 677 // errAbortReqBodyWrite is an internal error value. 678 // It doesn't escape to callers. 679 var errAbortReqBodyWrite = errors.New("http2: aborting request body write") 680 681 func (cs *clientStream) writeRequestBody(body io.ReadCloser) (err error) { 682 cc := cs.cc 683 sentEnd := false // whether we sent the final DATA frame w/ END_STREAM 684 buf := cc.frameScratchBuffer() 685 defer cc.putFrameScratchBuffer(buf) 686 687 defer func() { 688 // TODO: write h12Compare test showing whether 689 // Request.Body is closed by the Transport, 690 // and in multiple cases: server replies <=299 and >299 691 // while still writing request body 692 cerr := body.Close() 693 if err == nil { 694 err = cerr 695 } 696 }() 697 698 req := cs.req 699 hasTrailers := req.Trailer != nil 700 701 var sawEOF bool 702 for !sawEOF { 703 n, err := body.Read(buf) 704 if err == io.EOF { 705 sawEOF = true 706 err = nil 707 } else if err != nil { 708 return err 709 } 710 711 remain := buf[:n] 712 for len(remain) > 0 && err == nil { 713 var allowed int32 714 allowed, err = cs.awaitFlowControl(len(remain)) 715 if err != nil { 716 return err 717 } 718 cc.wmu.Lock() 719 data := remain[:allowed] 720 remain = remain[allowed:] 721 sentEnd = sawEOF && len(remain) == 0 && !hasTrailers 722 err = cc.fr.WriteData(cs.ID, sentEnd, data) 723 if err == nil { 724 // TODO(bradfitz): this flush is for latency, not bandwidth. 725 // Most requests won't need this. Make this opt-in or opt-out? 726 // Use some heuristic on the body type? Nagel-like timers? 727 // Based on 'n'? Only last chunk of this for loop, unless flow control 728 // tokens are low? For now, always: 729 err = cc.bw.Flush() 730 } 731 cc.wmu.Unlock() 732 } 733 if err != nil { 734 return err 735 } 736 } 737 738 cc.wmu.Lock() 739 if !sentEnd { 740 var trls []byte 741 if hasTrailers { 742 cc.mu.Lock() 743 trls = cc.encodeTrailers(req) 744 cc.mu.Unlock() 745 } 746 747 // Avoid forgetting to send an END_STREAM if the encoded 748 // trailers are 0 bytes. Both results produce and END_STREAM. 749 if len(trls) > 0 { 750 err = cc.writeHeaders(cs.ID, true, trls) 751 } else { 752 err = cc.fr.WriteData(cs.ID, true, nil) 753 } 754 } 755 if ferr := cc.bw.Flush(); ferr != nil && err == nil { 756 err = ferr 757 } 758 cc.wmu.Unlock() 759 760 return err 761 } 762 763 // awaitFlowControl waits for [1, min(maxBytes, cc.cs.maxFrameSize)] flow 764 // control tokens from the server. 765 // It returns either the non-zero number of tokens taken or an error 766 // if the stream is dead. 767 func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) { 768 cc := cs.cc 769 cc.mu.Lock() 770 defer cc.mu.Unlock() 771 for { 772 if cc.closed { 773 return 0, errClientConnClosed 774 } 775 if cs.stopReqBody { 776 return 0, errAbortReqBodyWrite 777 } 778 if err := cs.checkReset(); err != nil { 779 return 0, err 780 } 781 if a := cs.flow.available(); a > 0 { 782 take := a 783 if int(take) > maxBytes { 784 785 take = int32(maxBytes) // can't truncate int; take is int32 786 } 787 if take > int32(cc.maxFrameSize) { 788 take = int32(cc.maxFrameSize) 789 } 790 cs.flow.take(take) 791 return take, nil 792 } 793 cc.cond.Wait() 794 } 795 } 796 797 type badStringError struct { 798 what string 799 str string 800 } 801 802 func (e *badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) } 803 804 // requires cc.mu be held. 805 func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string) []byte { 806 cc.hbuf.Reset() 807 808 // TODO(bradfitz): figure out :authority-vs-Host stuff between http2 and Go 809 host := req.Host 810 if host == "" { 811 host = req.URL.Host 812 } 813 814 // 8.1.2.3 Request Pseudo-Header Fields 815 // The :path pseudo-header field includes the path and query parts of the 816 // target URI (the path-absolute production and optionally a '?' character 817 // followed by the query production (see Sections 3.3 and 3.4 of 818 // [RFC3986]). 819 cc.writeHeader(":authority", host) // probably not right for all sites 820 cc.writeHeader(":method", req.Method) 821 if req.Method != "CONNECT" { 822 cc.writeHeader(":path", req.URL.RequestURI()) 823 cc.writeHeader(":scheme", "https") 824 } 825 if trailers != "" { 826 cc.writeHeader("trailer", trailers) 827 } 828 829 var didUA bool 830 for k, vv := range req.Header { 831 lowKey := strings.ToLower(k) 832 if lowKey == "host" { 833 continue 834 } 835 if lowKey == "user-agent" { 836 // Match Go's http1 behavior: at most one 837 // User-Agent. If set to nil or empty string, 838 // then omit it. Otherwise if not mentioned, 839 // include the default (below). 840 didUA = true 841 if len(vv) < 1 { 842 continue 843 } 844 vv = vv[:1] 845 if vv[0] == "" { 846 continue 847 } 848 } 849 for _, v := range vv { 850 cc.writeHeader(lowKey, v) 851 } 852 } 853 if addGzipHeader { 854 cc.writeHeader("accept-encoding", "gzip") 855 } 856 if !didUA { 857 cc.writeHeader("user-agent", defaultUserAgent) 858 } 859 return cc.hbuf.Bytes() 860 } 861 862 // requires cc.mu be held. 863 func (cc *ClientConn) encodeTrailers(req *http.Request) []byte { 864 cc.hbuf.Reset() 865 for k, vv := range req.Trailer { 866 // Transfer-Encoding, etc.. have already been filter at the 867 // start of RoundTrip 868 lowKey := strings.ToLower(k) 869 for _, v := range vv { 870 cc.writeHeader(lowKey, v) 871 } 872 } 873 return cc.hbuf.Bytes() 874 } 875 876 func (cc *ClientConn) writeHeader(name, value string) { 877 cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value}) 878 } 879 880 type resAndError struct { 881 res *http.Response 882 err error 883 } 884 885 // requires cc.mu be held. 886 func (cc *ClientConn) newStream() *clientStream { 887 cs := &clientStream{ 888 cc: cc, 889 ID: cc.nextStreamID, 890 resc: make(chan resAndError, 1), 891 peerReset: make(chan struct{}), 892 done: make(chan struct{}), 893 } 894 cs.flow.add(int32(cc.initialWindowSize)) 895 cs.flow.setConnFlow(&cc.flow) 896 cs.inflow.add(transportDefaultStreamFlow) 897 cs.inflow.setConnFlow(&cc.inflow) 898 cc.nextStreamID += 2 899 cc.streams[cs.ID] = cs 900 return cs 901 } 902 903 func (cc *ClientConn) forgetStreamID(id uint32) { 904 cc.streamByID(id, true) 905 } 906 907 func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream { 908 cc.mu.Lock() 909 defer cc.mu.Unlock() 910 cs := cc.streams[id] 911 if andRemove && cs != nil { 912 delete(cc.streams, id) 913 close(cs.done) 914 } 915 return cs 916 } 917 918 // clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop. 919 type clientConnReadLoop struct { 920 cc *ClientConn 921 activeRes map[uint32]*clientStream // keyed by streamID 922 923 hdec *hpack.Decoder 924 925 // Fields reset on each HEADERS: 926 nextRes *http.Response 927 sawRegHeader bool // saw non-pseudo header 928 reqMalformed error // non-nil once known to be malformed 929 } 930 931 // readLoop runs in its own goroutine and reads and dispatches frames. 932 func (cc *ClientConn) readLoop() { 933 rl := &clientConnReadLoop{ 934 cc: cc, 935 activeRes: make(map[uint32]*clientStream), 936 } 937 // TODO: figure out henc size 938 rl.hdec = hpack.NewDecoder(initialHeaderTableSize, rl.onNewHeaderField) 939 940 defer rl.cleanup() 941 cc.readerErr = rl.run() 942 if ce, ok := cc.readerErr.(ConnectionError); ok { 943 cc.wmu.Lock() 944 cc.fr.WriteGoAway(0, ErrCode(ce), nil) 945 cc.wmu.Unlock() 946 } 947 } 948 949 func (rl *clientConnReadLoop) cleanup() { 950 cc := rl.cc 951 defer cc.tconn.Close() 952 defer cc.t.connPool().MarkDead(cc) 953 defer close(cc.readerDone) 954 955 // Close any response bodies if the server closes prematurely. 956 // TODO: also do this if we've written the headers but not 957 // gotten a response yet. 958 err := cc.readerErr 959 if err == io.EOF { 960 err = io.ErrUnexpectedEOF 961 } 962 cc.mu.Lock() 963 for _, cs := range rl.activeRes { 964 cs.bufPipe.CloseWithError(err) 965 } 966 for _, cs := range cc.streams { 967 select { 968 case cs.resc <- resAndError{err: err}: 969 default: 970 } 971 close(cs.done) 972 } 973 cc.closed = true 974 cc.cond.Broadcast() 975 cc.mu.Unlock() 976 } 977 978 func (rl *clientConnReadLoop) run() error { 979 cc := rl.cc 980 for { 981 f, err := cc.fr.ReadFrame() 982 if err != nil { 983 cc.vlogf("Transport readFrame error: (%T) %v", err, err) 984 } 985 if se, ok := err.(StreamError); ok { 986 // TODO: deal with stream errors from the framer. 987 return se 988 } else if err != nil { 989 return err 990 } 991 cc.vlogf("Transport received %v: %#v", f.Header(), f) 992 993 switch f := f.(type) { 994 case *HeadersFrame: 995 err = rl.processHeaders(f) 996 case *ContinuationFrame: 997 err = rl.processContinuation(f) 998 case *DataFrame: 999 err = rl.processData(f) 1000 case *GoAwayFrame: 1001 err = rl.processGoAway(f) 1002 case *RSTStreamFrame: 1003 err = rl.processResetStream(f) 1004 case *SettingsFrame: 1005 err = rl.processSettings(f) 1006 case *PushPromiseFrame: 1007 err = rl.processPushPromise(f) 1008 case *WindowUpdateFrame: 1009 err = rl.processWindowUpdate(f) 1010 case *PingFrame: 1011 err = rl.processPing(f) 1012 default: 1013 cc.logf("Transport: unhandled response frame type %T", f) 1014 } 1015 if err != nil { 1016 return err 1017 } 1018 } 1019 } 1020 1021 func (rl *clientConnReadLoop) processHeaders(f *HeadersFrame) error { 1022 rl.sawRegHeader = false 1023 rl.reqMalformed = nil 1024 rl.nextRes = &http.Response{ 1025 Proto: "HTTP/2.0", 1026 ProtoMajor: 2, 1027 Header: make(http.Header), 1028 } 1029 return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded()) 1030 } 1031 1032 func (rl *clientConnReadLoop) processContinuation(f *ContinuationFrame) error { 1033 return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded()) 1034 } 1035 1036 func (rl *clientConnReadLoop) processHeaderBlockFragment(frag []byte, streamID uint32, headersEnded, streamEnded bool) error { 1037 cc := rl.cc 1038 cs := cc.streamByID(streamID, streamEnded) 1039 if cs == nil { 1040 // We'd get here if we canceled a request while the 1041 // server was mid-way through replying with its 1042 // headers. (The case of a CONTINUATION arriving 1043 // without HEADERS would be rejected earlier by the 1044 // Framer). So if this was just something we canceled, 1045 // ignore it. 1046 return nil 1047 } 1048 if cs.headersDone { 1049 rl.hdec.SetEmitFunc(cs.onNewTrailerField) 1050 } else { 1051 rl.hdec.SetEmitFunc(rl.onNewHeaderField) 1052 } 1053 _, err := rl.hdec.Write(frag) 1054 if err != nil { 1055 return ConnectionError(ErrCodeCompression) 1056 } 1057 if err := rl.hdec.Close(); err != nil { 1058 return ConnectionError(ErrCodeCompression) 1059 } 1060 if !headersEnded { 1061 return nil 1062 } 1063 1064 if !cs.headersDone { 1065 cs.headersDone = true 1066 } else { 1067 // We're dealing with trailers. (and specifically the 1068 // final frame of headers) 1069 if cs.trailersDone { 1070 // Too many HEADERS frames for this stream. 1071 return ConnectionError(ErrCodeProtocol) 1072 } 1073 cs.trailersDone = true 1074 if !streamEnded { 1075 // We expect that any header block fragment 1076 // frame for trailers with END_HEADERS also 1077 // has END_STREAM. 1078 return ConnectionError(ErrCodeProtocol) 1079 } 1080 rl.endStream(cs) 1081 return nil 1082 } 1083 1084 if rl.reqMalformed != nil { 1085 cs.resc <- resAndError{err: rl.reqMalformed} 1086 rl.cc.writeStreamReset(cs.ID, ErrCodeProtocol, rl.reqMalformed) 1087 return nil 1088 } 1089 1090 res := rl.nextRes 1091 1092 if !streamEnded || cs.req.Method == "HEAD" { 1093 res.ContentLength = -1 1094 if clens := res.Header["Content-Length"]; len(clens) == 1 { 1095 if clen64, err := strconv.ParseInt(clens[0], 10, 64); err == nil { 1096 res.ContentLength = clen64 1097 } else { 1098 // TODO: care? unlike http/1, it won't mess up our framing, so it's 1099 // more safe smuggling-wise to ignore. 1100 } 1101 } else if len(clens) > 1 { 1102 // TODO: care? unlike http/1, it won't mess up our framing, so it's 1103 // more safe smuggling-wise to ignore. 1104 } 1105 } 1106 1107 if streamEnded { 1108 res.Body = noBody 1109 } else { 1110 buf := new(bytes.Buffer) // TODO(bradfitz): recycle this garbage 1111 cs.bufPipe = pipe{b: buf} 1112 cs.bytesRemain = res.ContentLength 1113 res.Body = transportResponseBody{cs} 1114 go cs.awaitRequestCancel(requestCancel(cs.req)) 1115 1116 if cs.requestedGzip && res.Header.Get("Content-Encoding") == "gzip" { 1117 res.Header.Del("Content-Encoding") 1118 res.Header.Del("Content-Length") 1119 res.ContentLength = -1 1120 res.Body = &gzipReader{body: res.Body} 1121 } 1122 } 1123 1124 cs.resTrailer = res.Trailer 1125 rl.activeRes[cs.ID] = cs 1126 cs.resc <- resAndError{res: res} 1127 rl.nextRes = nil // unused now; will be reset next HEADERS frame 1128 return nil 1129 } 1130 1131 // transportResponseBody is the concrete type of Transport.RoundTrip's 1132 // Response.Body. It is an io.ReadCloser. On Read, it reads from cs.body. 1133 // On Close it sends RST_STREAM if EOF wasn't already seen. 1134 type transportResponseBody struct { 1135 cs *clientStream 1136 } 1137 1138 func (b transportResponseBody) Read(p []byte) (n int, err error) { 1139 cs := b.cs 1140 cc := cs.cc 1141 1142 if cs.readErr != nil { 1143 return 0, cs.readErr 1144 } 1145 n, err = b.cs.bufPipe.Read(p) 1146 if cs.bytesRemain != -1 { 1147 if int64(n) > cs.bytesRemain { 1148 n = int(cs.bytesRemain) 1149 if err == nil { 1150 err = errors.New("net/http: server replied with more than declared Content-Length; truncated") 1151 cc.writeStreamReset(cs.ID, ErrCodeProtocol, err) 1152 } 1153 cs.readErr = err 1154 return int(cs.bytesRemain), err 1155 } 1156 cs.bytesRemain -= int64(n) 1157 if err == io.EOF && cs.bytesRemain > 0 { 1158 err = io.ErrUnexpectedEOF 1159 cs.readErr = err 1160 return n, err 1161 } 1162 } 1163 if n == 0 { 1164 // No flow control tokens to send back. 1165 return 1166 } 1167 1168 cc.mu.Lock() 1169 defer cc.mu.Unlock() 1170 1171 var connAdd, streamAdd int32 1172 // Check the conn-level first, before the stream-level. 1173 if v := cc.inflow.available(); v < transportDefaultConnFlow/2 { 1174 connAdd = transportDefaultConnFlow - v 1175 cc.inflow.add(connAdd) 1176 } 1177 if err == nil { // No need to refresh if the stream is over or failed. 1178 if v := cs.inflow.available(); v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh { 1179 streamAdd = transportDefaultStreamFlow - v 1180 cs.inflow.add(streamAdd) 1181 } 1182 } 1183 if connAdd != 0 || streamAdd != 0 { 1184 cc.wmu.Lock() 1185 defer cc.wmu.Unlock() 1186 if connAdd != 0 { 1187 cc.fr.WriteWindowUpdate(0, mustUint31(connAdd)) 1188 } 1189 if streamAdd != 0 { 1190 cc.fr.WriteWindowUpdate(cs.ID, mustUint31(streamAdd)) 1191 } 1192 cc.bw.Flush() 1193 } 1194 return 1195 } 1196 1197 var errClosedResponseBody = errors.New("http2: response body closed") 1198 1199 func (b transportResponseBody) Close() error { 1200 cs := b.cs 1201 if cs.bufPipe.Err() != io.EOF { 1202 // TODO: write test for this 1203 cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil) 1204 } 1205 cs.bufPipe.BreakWithError(errClosedResponseBody) 1206 return nil 1207 } 1208 1209 func (rl *clientConnReadLoop) processData(f *DataFrame) error { 1210 cc := rl.cc 1211 cs := cc.streamByID(f.StreamID, f.StreamEnded()) 1212 if cs == nil { 1213 return nil 1214 } 1215 data := f.Data() 1216 if VerboseLogs { 1217 rl.cc.logf("DATA: %q", data) 1218 } 1219 1220 // Check connection-level flow control. 1221 cc.mu.Lock() 1222 if cs.inflow.available() >= int32(len(data)) { 1223 cs.inflow.take(int32(len(data))) 1224 } else { 1225 cc.mu.Unlock() 1226 return ConnectionError(ErrCodeFlowControl) 1227 } 1228 cc.mu.Unlock() 1229 1230 if _, err := cs.bufPipe.Write(data); err != nil { 1231 return err 1232 } 1233 1234 if f.StreamEnded() { 1235 rl.endStream(cs) 1236 } 1237 return nil 1238 } 1239 1240 func (rl *clientConnReadLoop) endStream(cs *clientStream) { 1241 // TODO: check that any declared content-length matches, like 1242 // server.go's (*stream).endStream method. 1243 cs.bufPipe.closeWithErrorAndCode(io.EOF, cs.copyTrailers) 1244 delete(rl.activeRes, cs.ID) 1245 } 1246 1247 func (cs *clientStream) copyTrailers() { 1248 for k, vv := range cs.trailer { 1249 cs.resTrailer[k] = vv 1250 } 1251 } 1252 1253 func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error { 1254 cc := rl.cc 1255 cc.t.connPool().MarkDead(cc) 1256 if f.ErrCode != 0 { 1257 // TODO: deal with GOAWAY more. particularly the error code 1258 cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode) 1259 } 1260 cc.setGoAway(f) 1261 return nil 1262 } 1263 1264 func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error { 1265 cc := rl.cc 1266 cc.mu.Lock() 1267 defer cc.mu.Unlock() 1268 return f.ForeachSetting(func(s Setting) error { 1269 switch s.ID { 1270 case SettingMaxFrameSize: 1271 cc.maxFrameSize = s.Val 1272 case SettingMaxConcurrentStreams: 1273 cc.maxConcurrentStreams = s.Val 1274 case SettingInitialWindowSize: 1275 // TODO: error if this is too large. 1276 1277 // TODO: adjust flow control of still-open 1278 // frames by the difference of the old initial 1279 // window size and this one. 1280 cc.initialWindowSize = s.Val 1281 default: 1282 // TODO(bradfitz): handle more settings? 1283 cc.vlogf("Unhandled Setting: %v", s) 1284 } 1285 return nil 1286 }) 1287 } 1288 1289 func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error { 1290 cc := rl.cc 1291 cs := cc.streamByID(f.StreamID, false) 1292 if f.StreamID != 0 && cs == nil { 1293 return nil 1294 } 1295 1296 cc.mu.Lock() 1297 defer cc.mu.Unlock() 1298 1299 fl := &cc.flow 1300 if cs != nil { 1301 fl = &cs.flow 1302 } 1303 if !fl.add(int32(f.Increment)) { 1304 return ConnectionError(ErrCodeFlowControl) 1305 } 1306 cc.cond.Broadcast() 1307 return nil 1308 } 1309 1310 func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error { 1311 cs := rl.cc.streamByID(f.StreamID, true) 1312 if cs == nil { 1313 // TODO: return error if server tries to RST_STEAM an idle stream 1314 return nil 1315 } 1316 select { 1317 case <-cs.peerReset: 1318 // Already reset. 1319 // This is the only goroutine 1320 // which closes this, so there 1321 // isn't a race. 1322 default: 1323 err := StreamError{cs.ID, f.ErrCode} 1324 cs.resetErr = err 1325 close(cs.peerReset) 1326 cs.bufPipe.CloseWithError(err) 1327 cs.cc.cond.Broadcast() // wake up checkReset via clientStream.awaitFlowControl 1328 } 1329 delete(rl.activeRes, cs.ID) 1330 return nil 1331 } 1332 1333 func (rl *clientConnReadLoop) processPing(f *PingFrame) error { 1334 if f.IsAck() { 1335 // 6.7 PING: " An endpoint MUST NOT respond to PING frames 1336 // containing this flag." 1337 return nil 1338 } 1339 cc := rl.cc 1340 cc.wmu.Lock() 1341 defer cc.wmu.Unlock() 1342 if err := cc.fr.WritePing(true, f.Data); err != nil { 1343 return err 1344 } 1345 return cc.bw.Flush() 1346 } 1347 1348 func (rl *clientConnReadLoop) processPushPromise(f *PushPromiseFrame) error { 1349 // We told the peer we don't want them. 1350 // Spec says: 1351 // "PUSH_PROMISE MUST NOT be sent if the SETTINGS_ENABLE_PUSH 1352 // setting of the peer endpoint is set to 0. An endpoint that 1353 // has set this setting and has received acknowledgement MUST 1354 // treat the receipt of a PUSH_PROMISE frame as a connection 1355 // error (Section 5.4.1) of type PROTOCOL_ERROR." 1356 return ConnectionError(ErrCodeProtocol) 1357 } 1358 1359 func (cc *ClientConn) writeStreamReset(streamID uint32, code ErrCode, err error) { 1360 // TODO: do something with err? send it as a debug frame to the peer? 1361 // But that's only in GOAWAY. Invent a new frame type? Is there one already? 1362 cc.wmu.Lock() 1363 cc.fr.WriteRSTStream(streamID, code) 1364 cc.bw.Flush() 1365 cc.wmu.Unlock() 1366 } 1367 1368 // onNewHeaderField runs on the readLoop goroutine whenever a new 1369 // hpack header field is decoded. 1370 func (rl *clientConnReadLoop) onNewHeaderField(f hpack.HeaderField) { 1371 cc := rl.cc 1372 if VerboseLogs { 1373 cc.logf("Header field: %+v", f) 1374 } 1375 // TODO: enforce max header list size like server. 1376 isPseudo := strings.HasPrefix(f.Name, ":") 1377 if isPseudo { 1378 if rl.sawRegHeader { 1379 rl.reqMalformed = errors.New("http2: invalid pseudo header after regular header") 1380 return 1381 } 1382 switch f.Name { 1383 case ":status": 1384 code, err := strconv.Atoi(f.Value) 1385 if err != nil { 1386 rl.reqMalformed = errors.New("http2: invalid :status") 1387 return 1388 } 1389 rl.nextRes.Status = f.Value + " " + http.StatusText(code) 1390 rl.nextRes.StatusCode = code 1391 default: 1392 // "Endpoints MUST NOT generate pseudo-header 1393 // fields other than those defined in this 1394 // document." 1395 rl.reqMalformed = fmt.Errorf("http2: unknown response pseudo header %q", f.Name) 1396 } 1397 } else { 1398 rl.sawRegHeader = true 1399 key := http.CanonicalHeaderKey(f.Name) 1400 if key == "Trailer" { 1401 t := rl.nextRes.Trailer 1402 if t == nil { 1403 t = make(http.Header) 1404 rl.nextRes.Trailer = t 1405 } 1406 foreachHeaderElement(f.Value, func(v string) { 1407 t[http.CanonicalHeaderKey(v)] = nil 1408 }) 1409 } else { 1410 rl.nextRes.Header.Add(key, f.Value) 1411 } 1412 } 1413 } 1414 1415 func (cs *clientStream) onNewTrailerField(f hpack.HeaderField) { 1416 isPseudo := strings.HasPrefix(f.Name, ":") 1417 if isPseudo { 1418 // TODO: Bogus. report an error later when we close their body. 1419 // drop for now. 1420 return 1421 } 1422 key := http.CanonicalHeaderKey(f.Name) 1423 if _, ok := cs.resTrailer[key]; ok { 1424 if cs.trailer == nil { 1425 cs.trailer = make(http.Header) 1426 } 1427 const tooBig = 1000 // TODO: arbitrary; use max header list size limits 1428 if cur := cs.trailer[key]; len(cur) < tooBig { 1429 cs.trailer[key] = append(cur, f.Value) 1430 } 1431 } 1432 } 1433 1434 func (cc *ClientConn) logf(format string, args ...interface{}) { 1435 cc.t.logf(format, args...) 1436 } 1437 1438 func (cc *ClientConn) vlogf(format string, args ...interface{}) { 1439 cc.t.vlogf(format, args...) 1440 } 1441 1442 func (t *Transport) vlogf(format string, args ...interface{}) { 1443 if VerboseLogs { 1444 t.logf(format, args...) 1445 } 1446 } 1447 1448 func (t *Transport) logf(format string, args ...interface{}) { 1449 log.Printf(format, args...) 1450 } 1451 1452 var noBody io.ReadCloser = ioutil.NopCloser(bytes.NewReader(nil)) 1453 1454 func strSliceContains(ss []string, s string) bool { 1455 for _, v := range ss { 1456 if v == s { 1457 return true 1458 } 1459 } 1460 return false 1461 } 1462 1463 type erringRoundTripper struct{ err error } 1464 1465 func (rt erringRoundTripper) RoundTrip(*http.Request) (*http.Response, error) { return nil, rt.err } 1466 1467 // gzipReader wraps a response body so it can lazily 1468 // call gzip.NewReader on the first call to Read 1469 type gzipReader struct { 1470 body io.ReadCloser // underlying Response.Body 1471 zr io.Reader // lazily-initialized gzip reader 1472 } 1473 1474 func (gz *gzipReader) Read(p []byte) (n int, err error) { 1475 if gz.zr == nil { 1476 gz.zr, err = gzip.NewReader(gz.body) 1477 if err != nil { 1478 return 0, err 1479 } 1480 } 1481 return gz.zr.Read(p) 1482 } 1483 1484 func (gz *gzipReader) Close() error { 1485 return gz.body.Close() 1486 }