Check if conn is closed before writing to it.

AUTHORS.txt

@@ -38,6 +38,7 @@ Meelap Shah <[email protected]>
 Michael MacDonald <[email protected]>
 Michael MacDonald <[email protected]>
 Mikhail Bragin <[email protected]>
+Miroslav Šedivý <[email protected]>
 Nevio Vesic <[email protected]>
 Ori Bernstein <[email protected]>
 Robert Eperjesi <[email protected]>

agent_udpmux_test.go

@@ -83,6 +83,14 @@ func TestMuxAgent(t *testing.T) {
  require.NoError(t, conn.Close())
  require.NoError(t, muxedConn.Close())
  require.NoError(t, udpMux.Close())
+
+ // expect error when reading from closed mux
+ _, err = muxedConn.Read(data)
+ require.Error(t, err)
+
+ // expect error when writing to closed mux
+ _, err = muxedConn.Write(data)
+ require.Error(t, err)
  })
  }
 }

candidate_base.go

@@ -308,6 +308,10 @@ func (c *candidateBase) close() error {
 func (c *candidateBase) writeTo(raw []byte, dst Candidate) (int, error) {
  n, err := c.conn.WriteTo(raw, dst.addr())
  if err != nil {
+ // If the connection is closed, we should return the error
+ if errors.Is(err, io.ErrClosedPipe) {
+ return n, err
+ }
  c.agent().log.Infof("%s: %v", errSendPacket, err)
  return n, nil
  }

candidate_test.go

@@ -1,10 +1,13 @@
 package ice
 
 import (
+ "net"
  "testing"
  "time"
 
+ "github.com/pion/logging"
  "github.com/stretchr/testify/assert"
+ "github.com/stretchr/testify/require"
 )
 
 func TestCandidatePriority(t *testing.T) {
@@ -337,3 +340,43 @@ func TestCandidateMarshal(t *testing.T) {
  assert.Equal(t, test.marshaled, actualCandidate.Marshal())
  }
 }
+
+func TestCandidateWriteTo(t *testing.T) {
+ listener, err := net.ListenTCP("tcp", &net.TCPAddr{
+ IP: net.IP{127, 0, 0, 1},
+ Port: 0,
+ })
+ require.NoError(t, err, "error creating test tcp listener")
+
+ conn, err := net.DialTCP("tcp", nil, listener.Addr().(*net.TCPAddr))
+ require.NoError(t, err, "error dialing test tcp conn")
+
+ loggerFactory := logging.NewDefaultLoggerFactory()
+ packetConn := newTCPPacketConn(tcpPacketParams{
+ ReadBuffer: 2048,
+ Logger: loggerFactory.NewLogger("tcp-packet-conn"),
+ })
+
+ err = packetConn.AddConn(conn, nil)
+ require.NoError(t, err, "error adding test tcp conn to packet conn")
+
+ c1 := &candidateBase{
+ conn: packetConn,
+ currAgent: &Agent{
+ log: loggerFactory.NewLogger("agent"),
+ },
+ }
+
+ c2 := &candidateBase{
+ resolvedAddr: listener.Addr(),
+ }
+
+ _, err = c1.writeTo([]byte("test"), c2)
+ assert.NoError(t, err, "writing to open conn")
+
+ err = packetConn.Close()
+ require.NoError(t, err, "error closing test tcp conn")
+
+ _, err = c1.writeTo([]byte("test"), c2)
+ assert.Error(t, err, "writing to closed conn")
+}