func main() {
flag.Usage = usage
flag.Parse()
if flag.NArg() != 1 {
usage()
}
log.SetFlags(0)
host := flag.Arg(0)
app := &h2i{
host: host,
peerSetting: make(map[http2.SettingID]uint32),
}
app.henc = hpack.NewEncoder(&app.hbuf)
if err := app.Main(); err != nil {
if app.term != nil {
app.logf("%v\n", err)
} else {
fmt.Fprintf(os.Stderr, "%v\n", err)
}
os.Exit(1)
}
fmt.Fprintf(os.Stdout, "\n")
}
// newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is
// returned if something goes wrong.
func newHTTP2Server(conn net.Conn, maxStreams uint32, authInfo credentials.AuthInfo) (_ ServerTransport, err error) {
framer := newFramer(conn)
// Send initial settings as connection preface to client.
var settings []http2.Setting
// TODO(zhaoq): Have a better way to signal "no limit" because 0 is
// permitted in the HTTP2 spec.
if maxStreams == 0 {
maxStreams = math.MaxUint32
} else {
settings = append(settings, http2.Setting{http2.SettingMaxConcurrentStreams, maxStreams})
}
if initialWindowSize != defaultWindowSize {
settings = append(settings, http2.Setting{http2.SettingInitialWindowSize, uint32(initialWindowSize)})
}
if err := framer.writeSettings(true, settings...); err != nil {
return nil, ConnectionErrorf("transport: %v", err)
}
// Adjust the connection flow control window if needed.
if delta := uint32(initialConnWindowSize - defaultWindowSize); delta > 0 {
if err := framer.writeWindowUpdate(true, 0, delta); err != nil {
return nil, ConnectionErrorf("transport: %v", err)
}
}
var buf bytes.Buffer
t := &http2Server{
conn: conn,
authInfo: authInfo,
framer: framer,
hBuf: &buf,
hEnc: hpack.NewEncoder(&buf),
maxStreams: maxStreams,
controlBuf: newRecvBuffer(),
fc: &inFlow{limit: initialConnWindowSize},
sendQuotaPool: newQuotaPool(defaultWindowSize),
state: reachable,
writableChan: make(chan int, 1),
shutdownChan: make(chan struct{}),
activeStreams: make(map[uint32]*Stream),
streamSendQuota: defaultWindowSize,
}
go t.controller()
t.writableChan <- 0
return t, nil
}
// newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
// and starts to receive messages on it. Non-nil error returns if construction
// fails.
func newHTTP2Client(addr string, opts *ConnectOptions) (_ ClientTransport, err error) {
if opts.Dialer == nil {
// Set the default Dialer.
opts.Dialer = func(addr string, timeout time.Duration) (net.Conn, error) {
return net.DialTimeout("tcp", addr, timeout)
}
}
scheme := "http"
startT := time.Now()
timeout := opts.Timeout
conn, connErr := opts.Dialer(addr, timeout)
if connErr != nil {
return nil, ConnectionErrorf("transport: %v", connErr)
}
var authInfo credentials.AuthInfo
for _, c := range opts.AuthOptions {
if ccreds, ok := c.(credentials.TransportAuthenticator); ok {
scheme = "https"
// TODO(zhaoq): Now the first TransportAuthenticator is used if there are
// multiple ones provided. Revisit this if it is not appropriate. Probably
// place the ClientTransport construction into a separate function to make
// things clear.
if timeout > 0 {
timeout -= time.Since(startT)
}
conn, authInfo, connErr = ccreds.ClientHandshake(addr, conn, timeout)
break
}
}
if connErr != nil {
return nil, ConnectionErrorf("transport: %v", connErr)
}
defer func() {
if err != nil {
conn.Close()
}
}()
// Send connection preface to server.
n, err := conn.Write(clientPreface)
if err != nil {
return nil, ConnectionErrorf("transport: %v", err)
}
if n != len(clientPreface) {
return nil, ConnectionErrorf("transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
}
framer := newFramer(conn)
if initialWindowSize != defaultWindowSize {
err = framer.writeSettings(true, http2.Setting{http2.SettingInitialWindowSize, uint32(initialWindowSize)})
} else {
err = framer.writeSettings(true)
}
if err != nil {
return nil, ConnectionErrorf("transport: %v", err)
}
// Adjust the connection flow control window if needed.
if delta := uint32(initialConnWindowSize - defaultWindowSize); delta > 0 {
if err := framer.writeWindowUpdate(true, 0, delta); err != nil {
return nil, ConnectionErrorf("transport: %v", err)
}
}
ua := primaryUA
if opts.UserAgent != "" {
ua = opts.UserAgent + " " + ua
}
var buf bytes.Buffer
t := &http2Client{
target: addr,
userAgent: ua,
conn: conn,
authInfo: authInfo,
// The client initiated stream id is odd starting from 1.
nextID: 1,
writableChan: make(chan int, 1),
shutdownChan: make(chan struct{}),
errorChan: make(chan struct{}),
framer: framer,
hBuf: &buf,
hEnc: hpack.NewEncoder(&buf),
controlBuf: newRecvBuffer(),
fc: &inFlow{limit: initialConnWindowSize},
sendQuotaPool: newQuotaPool(defaultWindowSize),
scheme: scheme,
state: reachable,
activeStreams: make(map[uint32]*Stream),
authCreds: opts.AuthOptions,
maxStreams: math.MaxInt32,
streamSendQuota: defaultWindowSize,
}
go t.controller()
t.writableChan <- 0
// Start the reader goroutine for incoming message. The threading model
// on receiving is that each transport has a dedicated goroutine which
// reads HTTP2 frame from network. Then it dispatches the frame to the
// corresponding stream entity.
go t.reader()
return t, nil
}
func (t *Transport) newClientConn(host, port, key string) (*clientConn, error) {
cfg := &tls.Config{
ServerName: host,
NextProtos: []string{NextProtoTLS},
InsecureSkipVerify: t.InsecureTLSDial,
}
tconn, err := tls.Dial("tcp", net.JoinHostPort(host, port), cfg)
if err != nil {
return nil, err
}
if err := tconn.Handshake(); err != nil {
return nil, err
}
if !t.InsecureTLSDial {
if err := tconn.VerifyHostname(cfg.ServerName); err != nil {
return nil, err
}
}
state := tconn.ConnectionState()
if p := state.NegotiatedProtocol; p != NextProtoTLS {
// TODO(bradfitz): fall back to Fallback
return nil, fmt.Errorf("bad protocol: %v", p)
}
if !state.NegotiatedProtocolIsMutual {
return nil, errors.New("could not negotiate protocol mutually")
}
if _, err := tconn.Write(clientPreface); err != nil {
return nil, err
}
cc := &clientConn{
t: t,
tconn: tconn,
connKey: []string{key}, // TODO: cert's validated hostnames too
tlsState: &state,
readerDone: make(chan struct{}),
nextStreamID: 1,
maxFrameSize: 16 << 10, // spec default
initialWindowSize: 65535, // spec default
maxConcurrentStreams: 1000, // "infinite", per spec. 1000 seems good enough.
streams: make(map[uint32]*clientStream),
}
cc.bw = bufio.NewWriter(stickyErrWriter{tconn, &cc.werr})
cc.br = bufio.NewReader(tconn)
cc.fr = NewFramer(cc.bw, cc.br)
cc.henc = hpack.NewEncoder(&cc.hbuf)
cc.fr.WriteSettings()
// TODO: re-send more conn-level flow control tokens when server uses all these.
cc.fr.WriteWindowUpdate(0, 1<<30) // um, 0x7fffffff doesn't work to Google? it hangs?
cc.bw.Flush()
if cc.werr != nil {
return nil, cc.werr
}
// Read the obligatory SETTINGS frame
f, err := cc.fr.ReadFrame()
if err != nil {
return nil, err
}
sf, ok := f.(*SettingsFrame)
if !ok {
return nil, fmt.Errorf("expected settings frame, got: %T", f)
}
cc.fr.WriteSettingsAck()
cc.bw.Flush()
sf.ForeachSetting(func(s Setting) error {
switch s.ID {
case SettingMaxFrameSize:
cc.maxFrameSize = s.Val
case SettingMaxConcurrentStreams:
cc.maxConcurrentStreams = s.Val
case SettingInitialWindowSize:
cc.initialWindowSize = s.Val
default:
// TODO(bradfitz): handle more
log.Printf("Unhandled Setting: %v", s)
}
return nil
})
// TODO: figure out henc size
cc.hdec = hpack.NewDecoder(initialHeaderTableSize, cc.onNewHeaderField)
go cc.readLoop()
return cc, nil
}