diff --git a/http2/server.go b/http2/server.go index b16173c57..645c8da69 100644 --- a/http2/server.go +++ b/http2/server.go @@ -29,6 +29,7 @@ import ( "bufio" "bytes" "context" + "crypto/rand" "crypto/tls" "errors" "fmt" @@ -127,6 +128,16 @@ type Server struct { // If zero or negative, there is no timeout. IdleTimeout time.Duration + // ReadIdleTimeout is the timeout after which a health check using a ping + // frame will be carried out if no frame is received on the connection. + // If zero, no health check is performed. + ReadIdleTimeout time.Duration + + // PingTimeout is the timeout after which the connection will be closed + // if a response to a ping is not received. + // If zero, a default of 15 seconds is used. + PingTimeout time.Duration + // WriteByteTimeout is the timeout after which a connection will be // closed if no data can be written to it. The timeout begins when data is // available to write, and is extended whenever any bytes are written. @@ -644,9 +655,12 @@ type serverConn struct { inGoAway bool // we've started to or sent GOAWAY inFrameScheduleLoop bool // whether we're in the scheduleFrameWrite loop needToSendGoAway bool // we need to schedule a GOAWAY frame write + pingSent bool + sentPingData [8]byte goAwayCode ErrCode shutdownTimer timer // nil until used idleTimer timer // nil if unused + readIdleTimer timer // nil if unused // Owned by the writeFrameAsync goroutine: headerWriteBuf bytes.Buffer @@ -974,11 +988,17 @@ func (sc *serverConn) serve() { defer sc.idleTimer.Stop() } + if sc.srv.ReadIdleTimeout > 0 { + sc.readIdleTimer = sc.srv.afterFunc(sc.srv.ReadIdleTimeout, sc.onReadIdleTimer) + defer sc.readIdleTimer.Stop() + } + go sc.readFrames() // closed by defer sc.conn.Close above settingsTimer := sc.srv.afterFunc(firstSettingsTimeout, sc.onSettingsTimer) defer settingsTimer.Stop() + lastFrameTime := sc.srv.now() loopNum := 0 for { loopNum++ @@ -992,6 +1012,7 @@ func (sc *serverConn) serve() { case res := <-sc.wroteFrameCh: sc.wroteFrame(res) case res := <-sc.readFrameCh: + lastFrameTime = sc.srv.now() // Process any written frames before reading new frames from the client since a // written frame could have triggered a new stream to be started. if sc.writingFrameAsync { @@ -1023,6 +1044,8 @@ func (sc *serverConn) serve() { case idleTimerMsg: sc.vlogf("connection is idle") sc.goAway(ErrCodeNo) + case readIdleTimerMsg: + sc.handlePingTimer(lastFrameTime) case shutdownTimerMsg: sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr()) return @@ -1061,12 +1084,43 @@ func (sc *serverConn) serve() { } } +func (sc *serverConn) handlePingTimer(lastFrameReadTime time.Time) { + if sc.pingSent { + sc.vlogf("timeout waiting for PING response") + sc.conn.Close() + return + } + + pingAt := lastFrameReadTime.Add(sc.srv.ReadIdleTimeout) + now := sc.srv.now() + if pingAt.After(now) { + // We received frames since arming the ping timer. + // Reset it for the next possible timeout. + sc.readIdleTimer.Reset(pingAt.Sub(now)) + return + } + + sc.pingSent = true + // Ignore crypto/rand.Read errors: It generally can't fail, and worse case if it does + // is we send a PING frame containing 0s. + _, _ = rand.Read(sc.sentPingData[:]) + sc.writeFrame(FrameWriteRequest{ + write: &writePing{data: sc.sentPingData}, + }) + pingTimeout := sc.srv.PingTimeout + if pingTimeout <= 0 { + pingTimeout = 15 * time.Second + } + sc.readIdleTimer.Reset(pingTimeout) +} + type serverMessage int // Message values sent to serveMsgCh. var ( settingsTimerMsg = new(serverMessage) idleTimerMsg = new(serverMessage) + readIdleTimerMsg = new(serverMessage) shutdownTimerMsg = new(serverMessage) gracefulShutdownMsg = new(serverMessage) handlerDoneMsg = new(serverMessage) @@ -1074,6 +1128,7 @@ var ( func (sc *serverConn) onSettingsTimer() { sc.sendServeMsg(settingsTimerMsg) } func (sc *serverConn) onIdleTimer() { sc.sendServeMsg(idleTimerMsg) } +func (sc *serverConn) onReadIdleTimer() { sc.sendServeMsg(readIdleTimerMsg) } func (sc *serverConn) onShutdownTimer() { sc.sendServeMsg(shutdownTimerMsg) } func (sc *serverConn) sendServeMsg(msg interface{}) { @@ -1604,6 +1659,11 @@ func (sc *serverConn) processFrame(f Frame) error { func (sc *serverConn) processPing(f *PingFrame) error { sc.serveG.check() if f.IsAck() { + if sc.pingSent && sc.sentPingData == f.Data { + // This is a response to a PING we sent. + sc.pingSent = false + sc.readIdleTimer.Reset(sc.srv.ReadIdleTimeout) + } // 6.7 PING: " An endpoint MUST NOT respond to PING frames // containing this flag." return nil diff --git a/http2/server_test.go b/http2/server_test.go index ab53c2694..ec7ae043c 100644 --- a/http2/server_test.go +++ b/http2/server_test.go @@ -4706,3 +4706,46 @@ func TestServerWriteByteTimeout(t *testing.T) { st.advance(1 * time.Second) // timeout after failing to write any more bytes st.wantClosed() } + +func TestServerPingSent(t *testing.T) { + const readIdleTimeout = 15 * time.Second + st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) { + }, func(s *Server) { + s.ReadIdleTimeout = readIdleTimeout + }) + st.greet() + + st.wantIdle() + + st.advance(readIdleTimeout) + _ = readFrame[*PingFrame](t, st) + st.wantIdle() + + st.advance(14 * time.Second) + st.wantIdle() + st.advance(1 * time.Second) + st.wantClosed() +} + +func TestServerPingResponded(t *testing.T) { + const readIdleTimeout = 15 * time.Second + st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) { + }, func(s *Server) { + s.ReadIdleTimeout = readIdleTimeout + }) + st.greet() + + st.wantIdle() + + st.advance(readIdleTimeout) + pf := readFrame[*PingFrame](t, st) + st.wantIdle() + + st.advance(14 * time.Second) + st.wantIdle() + + st.writePing(true, pf.Data) + + st.advance(2 * time.Second) + st.wantIdle() +} diff --git a/http2/write.go b/http2/write.go index 33f61398a..6ff6bee7e 100644 --- a/http2/write.go +++ b/http2/write.go @@ -131,6 +131,16 @@ func (se StreamError) writeFrame(ctx writeContext) error { func (se StreamError) staysWithinBuffer(max int) bool { return frameHeaderLen+4 <= max } +type writePing struct { + data [8]byte +} + +func (w writePing) writeFrame(ctx writeContext) error { + return ctx.Framer().WritePing(false, w.data) +} + +func (w writePing) staysWithinBuffer(max int) bool { return frameHeaderLen+len(w.data) <= max } + type writePingAck struct{ pf *PingFrame } func (w writePingAck) writeFrame(ctx writeContext) error {