+++ /dev/null
-/*
- *
- * Copyright 2016 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// This file is the implementation of a gRPC server using HTTP/2 which
-// uses the standard Go http2 Server implementation (via the
-// http.Handler interface), rather than speaking low-level HTTP/2
-// frames itself. It is the implementation of *grpc.Server.ServeHTTP.
-
-package transport
-
-import (
- "errors"
- "fmt"
- "io"
- "net"
- "net/http"
- "strings"
- "sync"
- "time"
-
- "github.com/golang/protobuf/proto"
- "golang.org/x/net/context"
- "golang.org/x/net/http2"
- "google.golang.org/grpc/codes"
- "google.golang.org/grpc/credentials"
- "google.golang.org/grpc/metadata"
- "google.golang.org/grpc/peer"
- "google.golang.org/grpc/status"
-)
-
-// NewServerHandlerTransport returns a ServerTransport handling gRPC
-// from inside an http.Handler. It requires that the http Server
-// supports HTTP/2.
-func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request) (ServerTransport, error) {
- if r.ProtoMajor != 2 {
- return nil, errors.New("gRPC requires HTTP/2")
- }
- if r.Method != "POST" {
- return nil, errors.New("invalid gRPC request method")
- }
- if !validContentType(r.Header.Get("Content-Type")) {
- return nil, errors.New("invalid gRPC request content-type")
- }
- if _, ok := w.(http.Flusher); !ok {
- return nil, errors.New("gRPC requires a ResponseWriter supporting http.Flusher")
- }
- if _, ok := w.(http.CloseNotifier); !ok {
- return nil, errors.New("gRPC requires a ResponseWriter supporting http.CloseNotifier")
- }
-
- st := &serverHandlerTransport{
- rw: w,
- req: r,
- closedCh: make(chan struct{}),
- writes: make(chan func()),
- }
-
- if v := r.Header.Get("grpc-timeout"); v != "" {
- to, err := decodeTimeout(v)
- if err != nil {
- return nil, streamErrorf(codes.Internal, "malformed time-out: %v", err)
- }
- st.timeoutSet = true
- st.timeout = to
- }
-
- var metakv []string
- if r.Host != "" {
- metakv = append(metakv, ":authority", r.Host)
- }
- for k, vv := range r.Header {
- k = strings.ToLower(k)
- if isReservedHeader(k) && !isWhitelistedPseudoHeader(k) {
- continue
- }
- for _, v := range vv {
- v, err := decodeMetadataHeader(k, v)
- if err != nil {
- return nil, streamErrorf(codes.InvalidArgument, "malformed binary metadata: %v", err)
- }
- metakv = append(metakv, k, v)
- }
- }
- st.headerMD = metadata.Pairs(metakv...)
-
- return st, nil
-}
-
-// serverHandlerTransport is an implementation of ServerTransport
-// which replies to exactly one gRPC request (exactly one HTTP request),
-// using the net/http.Handler interface. This http.Handler is guaranteed
-// at this point to be speaking over HTTP/2, so it's able to speak valid
-// gRPC.
-type serverHandlerTransport struct {
- rw http.ResponseWriter
- req *http.Request
- timeoutSet bool
- timeout time.Duration
- didCommonHeaders bool
-
- headerMD metadata.MD
-
- closeOnce sync.Once
- closedCh chan struct{} // closed on Close
-
- // writes is a channel of code to run serialized in the
- // ServeHTTP (HandleStreams) goroutine. The channel is closed
- // when WriteStatus is called.
- writes chan func()
-
- mu sync.Mutex
- // streamDone indicates whether WriteStatus has been called and writes channel
- // has been closed.
- streamDone bool
-}
-
-func (ht *serverHandlerTransport) Close() error {
- ht.closeOnce.Do(ht.closeCloseChanOnce)
- return nil
-}
-
-func (ht *serverHandlerTransport) closeCloseChanOnce() { close(ht.closedCh) }
-
-func (ht *serverHandlerTransport) RemoteAddr() net.Addr { return strAddr(ht.req.RemoteAddr) }
-
-// strAddr is a net.Addr backed by either a TCP "ip:port" string, or
-// the empty string if unknown.
-type strAddr string
-
-func (a strAddr) Network() string {
- if a != "" {
- // Per the documentation on net/http.Request.RemoteAddr, if this is
- // set, it's set to the IP:port of the peer (hence, TCP):
- // https://golang.org/pkg/net/http/#Request
- //
- // If we want to support Unix sockets later, we can
- // add our own grpc-specific convention within the
- // grpc codebase to set RemoteAddr to a different
- // format, or probably better: we can attach it to the
- // context and use that from serverHandlerTransport.RemoteAddr.
- return "tcp"
- }
- return ""
-}
-
-func (a strAddr) String() string { return string(a) }
-
-// do runs fn in the ServeHTTP goroutine.
-func (ht *serverHandlerTransport) do(fn func()) error {
- // Avoid a panic writing to closed channel. Imperfect but maybe good enough.
- select {
- case <-ht.closedCh:
- return ErrConnClosing
- default:
- select {
- case ht.writes <- fn:
- return nil
- case <-ht.closedCh:
- return ErrConnClosing
- }
- }
-}
-
-func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) error {
- ht.mu.Lock()
- if ht.streamDone {
- ht.mu.Unlock()
- return nil
- }
- ht.streamDone = true
- ht.mu.Unlock()
- err := ht.do(func() {
- ht.writeCommonHeaders(s)
-
- // And flush, in case no header or body has been sent yet.
- // This forces a separation of headers and trailers if this is the
- // first call (for example, in end2end tests's TestNoService).
- ht.rw.(http.Flusher).Flush()
-
- h := ht.rw.Header()
- h.Set("Grpc-Status", fmt.Sprintf("%d", st.Code()))
- if m := st.Message(); m != "" {
- h.Set("Grpc-Message", encodeGrpcMessage(m))
- }
-
- if p := st.Proto(); p != nil && len(p.Details) > 0 {
- stBytes, err := proto.Marshal(p)
- if err != nil {
- // TODO: return error instead, when callers are able to handle it.
- panic(err)
- }
-
- h.Set("Grpc-Status-Details-Bin", encodeBinHeader(stBytes))
- }
-
- if md := s.Trailer(); len(md) > 0 {
- for k, vv := range md {
- // Clients don't tolerate reading restricted headers after some non restricted ones were sent.
- if isReservedHeader(k) {
- continue
- }
- for _, v := range vv {
- // http2 ResponseWriter mechanism to send undeclared Trailers after
- // the headers have possibly been written.
- h.Add(http2.TrailerPrefix+k, encodeMetadataHeader(k, v))
- }
- }
- }
- })
- close(ht.writes)
- return err
-}
-
-// writeCommonHeaders sets common headers on the first write
-// call (Write, WriteHeader, or WriteStatus).
-func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
- if ht.didCommonHeaders {
- return
- }
- ht.didCommonHeaders = true
-
- h := ht.rw.Header()
- h["Date"] = nil // suppress Date to make tests happy; TODO: restore
- h.Set("Content-Type", "application/grpc")
-
- // Predeclare trailers we'll set later in WriteStatus (after the body).
- // This is a SHOULD in the HTTP RFC, and the way you add (known)
- // Trailers per the net/http.ResponseWriter contract.
- // See https://golang.org/pkg/net/http/#ResponseWriter
- // and https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
- h.Add("Trailer", "Grpc-Status")
- h.Add("Trailer", "Grpc-Message")
- h.Add("Trailer", "Grpc-Status-Details-Bin")
-
- if s.sendCompress != "" {
- h.Set("Grpc-Encoding", s.sendCompress)
- }
-}
-
-func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
- return ht.do(func() {
- ht.writeCommonHeaders(s)
- ht.rw.Write(hdr)
- ht.rw.Write(data)
- if !opts.Delay {
- ht.rw.(http.Flusher).Flush()
- }
- })
-}
-
-func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
- return ht.do(func() {
- ht.writeCommonHeaders(s)
- h := ht.rw.Header()
- for k, vv := range md {
- // Clients don't tolerate reading restricted headers after some non restricted ones were sent.
- if isReservedHeader(k) {
- continue
- }
- for _, v := range vv {
- v = encodeMetadataHeader(k, v)
- h.Add(k, v)
- }
- }
- ht.rw.WriteHeader(200)
- ht.rw.(http.Flusher).Flush()
- })
-}
-
-func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), traceCtx func(context.Context, string) context.Context) {
- // With this transport type there will be exactly 1 stream: this HTTP request.
-
- var ctx context.Context
- var cancel context.CancelFunc
- if ht.timeoutSet {
- ctx, cancel = context.WithTimeout(context.Background(), ht.timeout)
- } else {
- ctx, cancel = context.WithCancel(context.Background())
- }
-
- // requestOver is closed when either the request's context is done
- // or the status has been written via WriteStatus.
- requestOver := make(chan struct{})
-
- // clientGone receives a single value if peer is gone, either
- // because the underlying connection is dead or because the
- // peer sends an http2 RST_STREAM.
- clientGone := ht.rw.(http.CloseNotifier).CloseNotify()
- go func() {
- select {
- case <-requestOver:
- return
- case <-ht.closedCh:
- case <-clientGone:
- }
- cancel()
- }()
-
- req := ht.req
-
- s := &Stream{
- id: 0, // irrelevant
- requestRead: func(int) {},
- cancel: cancel,
- buf: newRecvBuffer(),
- st: ht,
- method: req.URL.Path,
- recvCompress: req.Header.Get("grpc-encoding"),
- }
- pr := &peer.Peer{
- Addr: ht.RemoteAddr(),
- }
- if req.TLS != nil {
- pr.AuthInfo = credentials.TLSInfo{State: *req.TLS}
- }
- ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
- ctx = peer.NewContext(ctx, pr)
- s.ctx = newContextWithStream(ctx, s)
- s.trReader = &transportReader{
- reader: &recvBufferReader{ctx: s.ctx, recv: s.buf},
- windowHandler: func(int) {},
- }
-
- // readerDone is closed when the Body.Read-ing goroutine exits.
- readerDone := make(chan struct{})
- go func() {
- defer close(readerDone)
-
- // TODO: minimize garbage, optimize recvBuffer code/ownership
- const readSize = 8196
- for buf := make([]byte, readSize); ; {
- n, err := req.Body.Read(buf)
- if n > 0 {
- s.buf.put(recvMsg{data: buf[:n:n]})
- buf = buf[n:]
- }
- if err != nil {
- s.buf.put(recvMsg{err: mapRecvMsgError(err)})
- return
- }
- if len(buf) == 0 {
- buf = make([]byte, readSize)
- }
- }
- }()
-
- // startStream is provided by the *grpc.Server's serveStreams.
- // It starts a goroutine serving s and exits immediately.
- // The goroutine that is started is the one that then calls
- // into ht, calling WriteHeader, Write, WriteStatus, Close, etc.
- startStream(s)
-
- ht.runStream()
- close(requestOver)
-
- // Wait for reading goroutine to finish.
- req.Body.Close()
- <-readerDone
-}
-
-func (ht *serverHandlerTransport) runStream() {
- for {
- select {
- case fn, ok := <-ht.writes:
- if !ok {
- return
- }
- fn()
- case <-ht.closedCh:
- return
- }
- }
-}
-
-func (ht *serverHandlerTransport) Drain() {
- panic("Drain() is not implemented")
-}
-
-// mapRecvMsgError returns the non-nil err into the appropriate
-// error value as expected by callers of *grpc.parser.recvMsg.
-// In particular, in can only be:
-// * io.EOF
-// * io.ErrUnexpectedEOF
-// * of type transport.ConnectionError
-// * of type transport.StreamError
-func mapRecvMsgError(err error) error {
- if err == io.EOF || err == io.ErrUnexpectedEOF {
- return err
- }
- if se, ok := err.(http2.StreamError); ok {
- if code, ok := http2ErrConvTab[se.Code]; ok {
- return StreamError{
- Code: code,
- Desc: se.Error(),
- }
- }
- }
- return connectionErrorf(true, err, err.Error())
-}
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