vendor/google.golang.org/grpc/transport/http_util.go

   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
  19 package transport
  20
  21 import (
  22         "bufio"
  23         "bytes"
  24         "encoding/base64"
  25         "fmt"
  26         "io"
  27         "net"
  28         "net/http"
  29         "strconv"
  30         "strings"
  31         "sync/atomic"
  32         "time"
  33
  34         "github.com/golang/protobuf/proto"
  35         "golang.org/x/net/http2"
  36         "golang.org/x/net/http2/hpack"
  37         spb "google.golang.org/genproto/googleapis/rpc/status"
  38         "google.golang.org/grpc/codes"
  39         "google.golang.org/grpc/status"
  40 )
  41
  42 const (
  43         // http2MaxFrameLen specifies the max length of a HTTP2 frame.
  44         http2MaxFrameLen = 16384 // 16KB frame
  45         // http://http2.github.io/http2-spec/#SettingValues
  46         http2InitHeaderTableSize = 4096
  47         // http2IOBufSize specifies the buffer size for sending frames.
  48         http2IOBufSize = 32 * 1024
  49 )
  50
  51 var (
  52         clientPreface   = []byte(http2.ClientPreface)
  53         http2ErrConvTab = map[http2.ErrCode]codes.Code{
  54                 http2.ErrCodeNo:                 codes.Internal,
  55                 http2.ErrCodeProtocol:           codes.Internal,
  56                 http2.ErrCodeInternal:           codes.Internal,
  57                 http2.ErrCodeFlowControl:        codes.ResourceExhausted,
  58                 http2.ErrCodeSettingsTimeout:    codes.Internal,
  59                 http2.ErrCodeStreamClosed:       codes.Internal,
  60                 http2.ErrCodeFrameSize:          codes.Internal,
  61                 http2.ErrCodeRefusedStream:      codes.Unavailable,
  62                 http2.ErrCodeCancel:             codes.Canceled,
  63                 http2.ErrCodeCompression:        codes.Internal,
  64                 http2.ErrCodeConnect:            codes.Internal,
  65                 http2.ErrCodeEnhanceYourCalm:    codes.ResourceExhausted,
  66                 http2.ErrCodeInadequateSecurity: codes.PermissionDenied,
  67                 http2.ErrCodeHTTP11Required:     codes.FailedPrecondition,
  68         }
  69         statusCodeConvTab = map[codes.Code]http2.ErrCode{
  70                 codes.Internal:          http2.ErrCodeInternal,
  71                 codes.Canceled:          http2.ErrCodeCancel,
  72                 codes.Unavailable:       http2.ErrCodeRefusedStream,
  73                 codes.ResourceExhausted: http2.ErrCodeEnhanceYourCalm,
  74                 codes.PermissionDenied:  http2.ErrCodeInadequateSecurity,
  75         }
  76         httpStatusConvTab = map[int]codes.Code{
  77                 // 400 Bad Request - INTERNAL.
  78                 http.StatusBadRequest: codes.Internal,
  79                 // 401 Unauthorized  - UNAUTHENTICATED.
  80                 http.StatusUnauthorized: codes.Unauthenticated,
  81                 // 403 Forbidden - PERMISSION_DENIED.
  82                 http.StatusForbidden: codes.PermissionDenied,
  83                 // 404 Not Found - UNIMPLEMENTED.
  84                 http.StatusNotFound: codes.Unimplemented,
  85                 // 429 Too Many Requests - UNAVAILABLE.
  86                 http.StatusTooManyRequests: codes.Unavailable,
  87                 // 502 Bad Gateway - UNAVAILABLE.
  88                 http.StatusBadGateway: codes.Unavailable,
  89                 // 503 Service Unavailable - UNAVAILABLE.
  90                 http.StatusServiceUnavailable: codes.Unavailable,
  91                 // 504 Gateway timeout - UNAVAILABLE.
  92                 http.StatusGatewayTimeout: codes.Unavailable,
  93         }
  94 )
  95
  96 // Records the states during HPACK decoding. Must be reset once the
  97 // decoding of the entire headers are finished.
  98 type decodeState struct {
  99         encoding string
 100         // statusGen caches the stream status received from the trailer the server
 101         // sent.  Client side only.  Do not access directly.  After all trailers are
 102         // parsed, use the status method to retrieve the status.
 103         statusGen *status.Status
 104         // rawStatusCode and rawStatusMsg are set from the raw trailer fields and are not
 105         // intended for direct access outside of parsing.
 106         rawStatusCode *int
 107         rawStatusMsg  string
 108         httpStatus    *int
 109         // Server side only fields.
 110         timeoutSet bool
 111         timeout    time.Duration
 112         method     string
 113         // key-value metadata map from the peer.
 114         mdata map[string][]string
 115 }
 116
 117 // isReservedHeader checks whether hdr belongs to HTTP2 headers
 118 // reserved by gRPC protocol. Any other headers are classified as the
 119 // user-specified metadata.
 120 func isReservedHeader(hdr string) bool {
 121         if hdr != "" && hdr[0] == ':' {
 122                 return true
 123         }
 124         switch hdr {
 125         case "content-type",
 126                 "grpc-message-type",
 127                 "grpc-encoding",
 128                 "grpc-message",
 129                 "grpc-status",
 130                 "grpc-timeout",
 131                 "grpc-status-details-bin",
 132                 "te":
 133                 return true
 134         default:
 135                 return false
 136         }
 137 }
 138
 139 // isWhitelistedPseudoHeader checks whether hdr belongs to HTTP2 pseudoheaders
 140 // that should be propagated into metadata visible to users.
 141 func isWhitelistedPseudoHeader(hdr string) bool {
 142         switch hdr {
 143         case ":authority":
 144                 return true
 145         default:
 146                 return false
 147         }
 148 }
 149
 150 func validContentType(t string) bool {
 151         e := "application/grpc"
 152         if !strings.HasPrefix(t, e) {
 153                 return false
 154         }
 155         // Support variations on the content-type
 156         // (e.g. "application/grpc+blah", "application/grpc;blah").
 157         if len(t) > len(e) && t[len(e)] != '+' && t[len(e)] != ';' {
 158                 return false
 159         }
 160         return true
 161 }
 162
 163 func (d *decodeState) status() *status.Status {
 164         if d.statusGen == nil {
 165                 // No status-details were provided; generate status using code/msg.
 166                 d.statusGen = status.New(codes.Code(int32(*(d.rawStatusCode))), d.rawStatusMsg)
 167         }
 168         return d.statusGen
 169 }
 170
 171 const binHdrSuffix = "-bin"
 172
 173 func encodeBinHeader(v []byte) string {
 174         return base64.RawStdEncoding.EncodeToString(v)
 175 }
 176
 177 func decodeBinHeader(v string) ([]byte, error) {
 178         if len(v)%4 == 0 {
 179                 // Input was padded, or padding was not necessary.
 180                 return base64.StdEncoding.DecodeString(v)
 181         }
 182         return base64.RawStdEncoding.DecodeString(v)
 183 }
 184
 185 func encodeMetadataHeader(k, v string) string {
 186         if strings.HasSuffix(k, binHdrSuffix) {
 187                 return encodeBinHeader(([]byte)(v))
 188         }
 189         return v
 190 }
 191
 192 func decodeMetadataHeader(k, v string) (string, error) {
 193         if strings.HasSuffix(k, binHdrSuffix) {
 194                 b, err := decodeBinHeader(v)
 195                 return string(b), err
 196         }
 197         return v, nil
 198 }
 199
 200 func (d *decodeState) decodeResponseHeader(frame *http2.MetaHeadersFrame) error {
 201         for _, hf := range frame.Fields {
 202                 if err := d.processHeaderField(hf); err != nil {
 203                         return err
 204                 }
 205         }
 206
 207         // If grpc status exists, no need to check further.
 208         if d.rawStatusCode != nil || d.statusGen != nil {
 209                 return nil
 210         }
 211
 212         // If grpc status doesn't exist and http status doesn't exist,
 213         // then it's a malformed header.
 214         if d.httpStatus == nil {
 215                 return streamErrorf(codes.Internal, "malformed header: doesn't contain status(gRPC or HTTP)")
 216         }
 217
 218         if *(d.httpStatus) != http.StatusOK {
 219                 code, ok := httpStatusConvTab[*(d.httpStatus)]
 220                 if !ok {
 221                         code = codes.Unknown
 222                 }
 223                 return streamErrorf(code, http.StatusText(*(d.httpStatus)))
 224         }
 225
 226         // gRPC status doesn't exist and http status is OK.
 227         // Set rawStatusCode to be unknown and return nil error.
 228         // So that, if the stream has ended this Unknown status
 229         // will be propogated to the user.
 230         // Otherwise, it will be ignored. In which case, status from
 231         // a later trailer, that has StreamEnded flag set, is propogated.
 232         code := int(codes.Unknown)
 233         d.rawStatusCode = &code
 234         return nil
 235
 236 }
 237
 238 func (d *decodeState) processHeaderField(f hpack.HeaderField) error {
 239         switch f.Name {
 240         case "content-type":
 241                 if !validContentType(f.Value) {
 242                         return streamErrorf(codes.FailedPrecondition, "transport: received the unexpected content-type %q", f.Value)
 243                 }
 244         case "grpc-encoding":
 245                 d.encoding = f.Value
 246         case "grpc-status":
 247                 code, err := strconv.Atoi(f.Value)
 248                 if err != nil {
 249                         return streamErrorf(codes.Internal, "transport: malformed grpc-status: %v", err)
 250                 }
 251                 d.rawStatusCode = &code
 252         case "grpc-message":
 253                 d.rawStatusMsg = decodeGrpcMessage(f.Value)
 254         case "grpc-status-details-bin":
 255                 v, err := decodeBinHeader(f.Value)
 256                 if err != nil {
 257                         return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
 258                 }
 259                 s := &spb.Status{}
 260                 if err := proto.Unmarshal(v, s); err != nil {
 261                         return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
 262                 }
 263                 d.statusGen = status.FromProto(s)
 264         case "grpc-timeout":
 265                 d.timeoutSet = true
 266                 var err error
 267                 if d.timeout, err = decodeTimeout(f.Value); err != nil {
 268                         return streamErrorf(codes.Internal, "transport: malformed time-out: %v", err)
 269                 }
 270         case ":path":
 271                 d.method = f.Value
 272         case ":status":
 273                 code, err := strconv.Atoi(f.Value)
 274                 if err != nil {
 275                         return streamErrorf(codes.Internal, "transport: malformed http-status: %v", err)
 276                 }
 277                 d.httpStatus = &code
 278         default:
 279                 if !isReservedHeader(f.Name) || isWhitelistedPseudoHeader(f.Name) {
 280                         if d.mdata == nil {
 281                                 d.mdata = make(map[string][]string)
 282                         }
 283                         v, err := decodeMetadataHeader(f.Name, f.Value)
 284                         if err != nil {
 285                                 errorf("Failed to decode metadata header (%q, %q): %v", f.Name, f.Value, err)
 286                                 return nil
 287                         }
 288                         d.mdata[f.Name] = append(d.mdata[f.Name], v)
 289                 }
 290         }
 291         return nil
 292 }
 293
 294 type timeoutUnit uint8
 295
 296 const (
 297         hour        timeoutUnit = 'H'
 298         minute      timeoutUnit = 'M'
 299         second      timeoutUnit = 'S'
 300         millisecond timeoutUnit = 'm'
 301         microsecond timeoutUnit = 'u'
 302         nanosecond  timeoutUnit = 'n'
 303 )
 304
 305 func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) {
 306         switch u {
 307         case hour:
 308                 return time.Hour, true
 309         case minute:
 310                 return time.Minute, true
 311         case second:
 312                 return time.Second, true
 313         case millisecond:
 314                 return time.Millisecond, true
 315         case microsecond:
 316                 return time.Microsecond, true
 317         case nanosecond:
 318                 return time.Nanosecond, true
 319         default:
 320         }
 321         return
 322 }
 323
 324 const maxTimeoutValue int64 = 100000000 - 1
 325
 326 // div does integer division and round-up the result. Note that this is
 327 // equivalent to (d+r-1)/r but has less chance to overflow.
 328 func div(d, r time.Duration) int64 {
 329         if m := d % r; m > 0 {
 330                 return int64(d/r + 1)
 331         }
 332         return int64(d / r)
 333 }
 334
 335 // TODO(zhaoq): It is the simplistic and not bandwidth efficient. Improve it.
 336 func encodeTimeout(t time.Duration) string {
 337         if t <= 0 {
 338                 return "0n"
 339         }
 340         if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
 341                 return strconv.FormatInt(d, 10) + "n"
 342         }
 343         if d := div(t, time.Microsecond); d <= maxTimeoutValue {
 344                 return strconv.FormatInt(d, 10) + "u"
 345         }
 346         if d := div(t, time.Millisecond); d <= maxTimeoutValue {
 347                 return strconv.FormatInt(d, 10) + "m"
 348         }
 349         if d := div(t, time.Second); d <= maxTimeoutValue {
 350                 return strconv.FormatInt(d, 10) + "S"
 351         }
 352         if d := div(t, time.Minute); d <= maxTimeoutValue {
 353                 return strconv.FormatInt(d, 10) + "M"
 354         }
 355         // Note that maxTimeoutValue * time.Hour > MaxInt64.
 356         return strconv.FormatInt(div(t, time.Hour), 10) + "H"
 357 }
 358
 359 func decodeTimeout(s string) (time.Duration, error) {
 360         size := len(s)
 361         if size < 2 {
 362                 return 0, fmt.Errorf("transport: timeout string is too short: %q", s)
 363         }
 364         unit := timeoutUnit(s[size-1])
 365         d, ok := timeoutUnitToDuration(unit)
 366         if !ok {
 367                 return 0, fmt.Errorf("transport: timeout unit is not recognized: %q", s)
 368         }
 369         t, err := strconv.ParseInt(s[:size-1], 10, 64)
 370         if err != nil {
 371                 return 0, err
 372         }
 373         return d * time.Duration(t), nil
 374 }
 375
 376 const (
 377         spaceByte   = ' '
 378         tildaByte   = '~'
 379         percentByte = '%'
 380 )
 381
 382 // encodeGrpcMessage is used to encode status code in header field
 383 // "grpc-message".
 384 // It checks to see if each individual byte in msg is an
 385 // allowable byte, and then either percent encoding or passing it through.
 386 // When percent encoding, the byte is converted into hexadecimal notation
 387 // with a '%' prepended.
 388 func encodeGrpcMessage(msg string) string {
 389         if msg == "" {
 390                 return ""
 391         }
 392         lenMsg := len(msg)
 393         for i := 0; i < lenMsg; i++ {
 394                 c := msg[i]
 395                 if !(c >= spaceByte && c < tildaByte && c != percentByte) {
 396                         return encodeGrpcMessageUnchecked(msg)
 397                 }
 398         }
 399         return msg
 400 }
 401
 402 func encodeGrpcMessageUnchecked(msg string) string {
 403         var buf bytes.Buffer
 404         lenMsg := len(msg)
 405         for i := 0; i < lenMsg; i++ {
 406                 c := msg[i]
 407                 if c >= spaceByte && c < tildaByte && c != percentByte {
 408                         buf.WriteByte(c)
 409                 } else {
 410                         buf.WriteString(fmt.Sprintf("%%%02X", c))
 411                 }
 412         }
 413         return buf.String()
 414 }
 415
 416 // decodeGrpcMessage decodes the msg encoded by encodeGrpcMessage.
 417 func decodeGrpcMessage(msg string) string {
 418         if msg == "" {
 419                 return ""
 420         }
 421         lenMsg := len(msg)
 422         for i := 0; i < lenMsg; i++ {
 423                 if msg[i] == percentByte && i+2 < lenMsg {
 424                         return decodeGrpcMessageUnchecked(msg)
 425                 }
 426         }
 427         return msg
 428 }
 429
 430 func decodeGrpcMessageUnchecked(msg string) string {
 431         var buf bytes.Buffer
 432         lenMsg := len(msg)
 433         for i := 0; i < lenMsg; i++ {
 434                 c := msg[i]
 435                 if c == percentByte && i+2 < lenMsg {
 436                         parsed, err := strconv.ParseUint(msg[i+1:i+3], 16, 8)
 437                         if err != nil {
 438                                 buf.WriteByte(c)
 439                         } else {
 440                                 buf.WriteByte(byte(parsed))
 441                                 i += 2
 442                         }
 443                 } else {
 444                         buf.WriteByte(c)
 445                 }
 446         }
 447         return buf.String()
 448 }
 449
 450 type framer struct {
 451         numWriters int32
 452         reader     io.Reader
 453         writer     *bufio.Writer
 454         fr         *http2.Framer
 455 }
 456
 457 func newFramer(conn net.Conn) *framer {
 458         f := &framer{
 459                 reader: bufio.NewReaderSize(conn, http2IOBufSize),
 460                 writer: bufio.NewWriterSize(conn, http2IOBufSize),
 461         }
 462         f.fr = http2.NewFramer(f.writer, f.reader)
 463         // Opt-in to Frame reuse API on framer to reduce garbage.
 464         // Frames aren't safe to read from after a subsequent call to ReadFrame.
 465         f.fr.SetReuseFrames()
 466         f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
 467         return f
 468 }
 469
 470 func (f *framer) adjustNumWriters(i int32) int32 {
 471         return atomic.AddInt32(&f.numWriters, i)
 472 }
 473
 474 // The following writeXXX functions can only be called when the caller gets
 475 // unblocked from writableChan channel (i.e., owns the privilege to write).
 476
 477 func (f *framer) writeContinuation(forceFlush bool, streamID uint32, endHeaders bool, headerBlockFragment []byte) error {
 478         if err := f.fr.WriteContinuation(streamID, endHeaders, headerBlockFragment); err != nil {
 479                 return err
 480         }
 481         if forceFlush {
 482                 return f.writer.Flush()
 483         }
 484         return nil
 485 }
 486
 487 func (f *framer) writeData(forceFlush bool, streamID uint32, endStream bool, data []byte) error {
 488         if err := f.fr.WriteData(streamID, endStream, data); err != nil {
 489                 return err
 490         }
 491         if forceFlush {
 492                 return f.writer.Flush()
 493         }
 494         return nil
 495 }
 496
 497 func (f *framer) writeGoAway(forceFlush bool, maxStreamID uint32, code http2.ErrCode, debugData []byte) error {
 498         if err := f.fr.WriteGoAway(maxStreamID, code, debugData); err != nil {
 499                 return err
 500         }
 501         if forceFlush {
 502                 return f.writer.Flush()
 503         }
 504         return nil
 505 }
 506
 507 func (f *framer) writeHeaders(forceFlush bool, p http2.HeadersFrameParam) error {
 508         if err := f.fr.WriteHeaders(p); err != nil {
 509                 return err
 510         }
 511         if forceFlush {
 512                 return f.writer.Flush()
 513         }
 514         return nil
 515 }
 516
 517 func (f *framer) writePing(forceFlush, ack bool, data [8]byte) error {
 518         if err := f.fr.WritePing(ack, data); err != nil {
 519                 return err
 520         }
 521         if forceFlush {
 522                 return f.writer.Flush()
 523         }
 524         return nil
 525 }
 526
 527 func (f *framer) writePriority(forceFlush bool, streamID uint32, p http2.PriorityParam) error {
 528         if err := f.fr.WritePriority(streamID, p); err != nil {
 529                 return err
 530         }
 531         if forceFlush {
 532                 return f.writer.Flush()
 533         }
 534         return nil
 535 }
 536
 537 func (f *framer) writePushPromise(forceFlush bool, p http2.PushPromiseParam) error {
 538         if err := f.fr.WritePushPromise(p); err != nil {
 539                 return err
 540         }
 541         if forceFlush {
 542                 return f.writer.Flush()
 543         }
 544         return nil
 545 }
 546
 547 func (f *framer) writeRSTStream(forceFlush bool, streamID uint32, code http2.ErrCode) error {
 548         if err := f.fr.WriteRSTStream(streamID, code); err != nil {
 549                 return err
 550         }
 551         if forceFlush {
 552                 return f.writer.Flush()
 553         }
 554         return nil
 555 }
 556
 557 func (f *framer) writeSettings(forceFlush bool, settings ...http2.Setting) error {
 558         if err := f.fr.WriteSettings(settings...); err != nil {
 559                 return err
 560         }
 561         if forceFlush {
 562                 return f.writer.Flush()
 563         }
 564         return nil
 565 }
 566
 567 func (f *framer) writeSettingsAck(forceFlush bool) error {
 568         if err := f.fr.WriteSettingsAck(); err != nil {
 569                 return err
 570         }
 571         if forceFlush {
 572                 return f.writer.Flush()
 573         }
 574         return nil
 575 }
 576
 577 func (f *framer) writeWindowUpdate(forceFlush bool, streamID, incr uint32) error {
 578         if err := f.fr.WriteWindowUpdate(streamID, incr); err != nil {
 579                 return err
 580         }
 581         if forceFlush {
 582                 return f.writer.Flush()
 583         }
 584         return nil
 585 }
 586
 587 func (f *framer) flushWrite() error {
 588         return f.writer.Flush()
 589 }
 590
 591 func (f *framer) readFrame() (http2.Frame, error) {
 592         return f.fr.ReadFrame()
 593 }
 594
 595 func (f *framer) errorDetail() error {
 596         return f.fr.ErrorDetail()
 597 }