WebRTC is holding sockets open

[anacrolix]

Running confluence with some implicit websocket trackers results in a slow leak of UDP sockets. Here's some relevant stack traces:

745 @ 0x44d476 0x45cf12 0x938e45 0x47d121
#	0x938e44	github.com/pion/ice/v2.(*candidateBase).recvLoop+0xc4	/root/go/pkg/mod/github.com/pion/ice/[email protected]/candidate_base.go:213

186 @ 0x44d476 0x4197ec 0x419258 0x9305c8 0x47d121
#	0x9305c7	github.com/pion/ice/v2.(*Agent).startOnConnectionStateChangeRoutine.func1+0x47	/root/go/pkg/mod/github.com/pion/ice/[email protected]/agent.go:413

186 @ 0x44d476 0x45cf12 0x52147e 0x47d121
#	0x52147d	context.propagateCancel.func1+0x9d	/root/src/go.master/src/context/context.go:279

186 @ 0x44d476 0x45cf12 0x92ecc5 0x47d121
#	0x92ecc4	github.com/pion/ice/v2.(*Agent).taskLoop+0x144	/root/go/pkg/mod/github.com/pion/ice/[email protected]/agent.go:223

186 @ 0x44d476 0x45cf12 0x93032d 0x47d121
#	0x93032c	github.com/pion/ice/v2.(*Agent).startOnConnectionStateChangeRoutine.func2+0xac	/root/go/pkg/mod/github.com/pion/ice/[email protected]/agent.go:422

164 @ 0x44d476 0x4465f3 0x477949 0x4dc6b2 0x4e2e05 0x4e2de9 0x573805 0x8fa482 0x90400e 0x903ff4 0x908ea7 0x47d121
#	0x477948	internal/poll.runtime_pollWait+0x88			/root/src/go.master/src/runtime/netpoll.go:233
#	0x4dc6b1	internal/poll.(*pollDesc).wait+0x31			/root/src/go.master/src/internal/poll/fd_poll_runtime.go:83
#	0x4e2e04	internal/poll.(*pollDesc).waitRead+0x144		/root/src/go.master/src/internal/poll/fd_poll_runtime.go:88
#	0x4e2de8	internal/poll.(*FD).RawRead+0x128			/root/src/go.master/src/internal/poll/fd_unix.go:766
#	0x573804	net.(*rawConn).Read+0x44				/root/src/go.master/src/net/rawconn.go:43
#	0x8fa481	golang.org/x/net/internal/socket.(*Conn).recvMsg+0x201	/root/go/pkg/mod/golang.org/x/[email protected]/internal/socket/rawconn_msg.go:29
#	0x90400d	golang.org/x/net/internal/socket.(*Conn).RecvMsg+0x1cd	/root/go/pkg/mod/golang.org/x/[email protected]/internal/socket/socket.go:247
#	0x903ff3	golang.org/x/net/ipv4.(*payloadHandler).ReadFrom+0x1b3	/root/go/pkg/mod/golang.org/x/[email protected]/ipv4/payload_cmsg.go:32
#	0x908ea6	github.com/pion/mdns.(*Conn).start+0x106		/root/go/pkg/mod/github.com/pion/[email protected]/conn.go:258

110 @ 0x44d476 0x45cf12 0x8b9bc8 0x94f405 0x8e92fa 0x47d121
#	0x8b9bc7	github.com/pion/transport/packetio.(*Buffer).Read+0x167		/root/go/pkg/mod/github.com/pion/[email protected]/packetio/buffer.go:266
#	0x94f404	github.com/pion/webrtc/v3/internal/mux.(*Endpoint).Read+0x24	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/internal/mux/endpoint.go:37
#	0x8e92f9	github.com/pion/srtp/v2.(*session).start.func1+0xb9		/root/go/pkg/mod/github.com/pion/srtp/[email protected]/session.go:134

56 @ 0x44d476 0x45cf12 0x930f2b 0x47d121
#	0x930f2a	github.com/pion/ice/v2.(*Agent).connectivityChecks+0x1aa	/root/go/pkg/mod/github.com/pion/ice/[email protected]/agent.go:539

55 @ 0x44d476 0x4197ec 0x419258 0x7c4cc6 0x47d121
#	0x7c4cc5	github.com/anacrolix/torrent/peer_protocol.handshakeWriter+0x65	/root/dev-gopath/src/github.com/anacrolix/torrent/peer_protocol/handshake.go:23

55 @ 0x44d476 0x4197ec 0x419258 0x7fcea5 0x7fce88 0x989d08 0x47d121
#	0x7fcea4	github.com/pion/sctp.(*Association).AcceptStream+0x44			/root/go/pkg/mod/github.com/pion/[email protected]/association.go:1307
#	0x7fce87	github.com/pion/datachannel.Accept+0x27					/root/go/pkg/mod/github.com/pion/[email protected]/datachannel.go:116
#	0x989d07	github.com/pion/webrtc/v3.(*SCTPTransport).acceptDataChannels+0x287	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/sctptransport.go:175

55 @ 0x44d476 0x4197ec 0x419258 0x8e9bec 0x977445 0x47d121
#	0x8e9beb	github.com/pion/srtp/v2.(*SessionSRTCP).AcceptStream+0x2b			/root/go/pkg/mod/github.com/pion/srtp/[email protected]/session_srtcp.go:92
#	0x977444	github.com/pion/webrtc/v3.(*PeerConnection).undeclaredMediaProcessor.func2+0xe4	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/peerconnection.go:1603

55 @ 0x44d476 0x4197ec 0x419258 0x8eabcc 0x9776b9 0x47d121
#	0x8eabcb	github.com/pion/srtp/v2.(*SessionSRTP).AcceptStream+0x2b			/root/go/pkg/mod/github.com/pion/srtp/[email protected]/session_srtp.go:94
#	0x9776b8	github.com/pion/webrtc/v3.(*PeerConnection).undeclaredMediaProcessor.func1+0xd8	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/peerconnection.go:1565

55 @ 0x44d476 0x45cf12 0x7dc4a6 0x47d121
#	0x7dc4a5	github.com/pion/sctp.(*Association).writeLoop+0x205	/root/go/pkg/mod/github.com/pion/[email protected]/association.go:558

55 @ 0x44d476 0x45cf12 0x8b7489 0x47d121
#	0x8b7488	github.com/pion/transport/connctx.(*connCtx).ReadContext.func1+0xc8	/root/go/pkg/mod/github.com/pion/[email protected]/connctx/connctx.go:78

55 @ 0x44d476 0x45cf12 0x8b9bc8 0x948973 0x94fe0b 0x47d121
#	0x8b9bc7	github.com/pion/transport/packetio.(*Buffer).Read+0x167		/root/go/pkg/mod/github.com/pion/[email protected]/packetio/buffer.go:266
#	0x948972	github.com/pion/ice/v2.(*Conn).Read+0x72			/root/go/pkg/mod/github.com/pion/ice/[email protected]/transport.go:73
#	0x94fe0a	github.com/pion/webrtc/v3/internal/mux.(*Mux).readLoop+0xca	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/internal/mux/mux.go:107

55 @ 0x44d476 0x45cf12 0x8b9bc8 0x94f405 0x8b71ce 0x8bfc0e 0x8c24c5 0x47d121
#	0x8b9bc7	github.com/pion/transport/packetio.(*Buffer).Read+0x167		/root/go/pkg/mod/github.com/pion/[email protected]/packetio/buffer.go:266
#	0x94f404	github.com/pion/webrtc/v3/internal/mux.(*Endpoint).Read+0x24	/root/go/pkg/mod/github.com/pion/webrtc/[email protected]/internal/mux/endpoint.go:37
#	0x8b71cd	github.com/pion/transport/connctx.(*connCtx).ReadContext+0x22d	/root/go/pkg/mod/github.com/pion/[email protected]/connctx/connctx.go:93
#	0x8bfc0d	github.com/pion/dtls/v2.(*Conn).readAndBuffer+0x10d		/root/go/pkg/mod/github.com/pion/dtls/[email protected]/conn.go:570
#	0x8c24c4	github.com/pion/dtls/v2.(*Conn).handshake.func3+0x104		/root/go/pkg/mod/github.com/pion/dtls/[email protected]/conn.go:852

55 @ 0x44d476 0x45cf12 0x8bdba5 0x7dba7e 0x47d121
#	0x8bdba4	github.com/pion/dtls/v2.(*Conn).Read+0x164		/root/go/pkg/mod/github.com/pion/dtls/[email protected]/conn.go:294
#	0x7dba7d	github.com/pion/sctp.(*Association).readLoop+0x15d	/root/go/pkg/mod/github.com/pion/[email protected]/association.go:509

55 @ 0x44d476 0x45cf12 0x8d42d2 0x8d313d 0x8c2ae5 0x47d121
#	0x8d42d1	github.com/pion/dtls/v2.(*handshakeFSM).finish+0x251	/root/go/pkg/mod/github.com/pion/dtls/[email protected]/handshaker.go:312
#	0x8d313c	github.com/pion/dtls/v2.(*handshakeFSM).Run+0x43c	/root/go/pkg/mod/github.com/pion/dtls/[email protected]/handshaker.go:179
#	0x8c2ae4	github.com/pion/dtls/v2.(*Conn).handshake.func2+0x84	/root/go/pkg/mod/github.com/pion/dtls/[email protected]/conn.go:833

55 @ 0x44d476 0x47927d 0x47925d 0x49146c 0x7f776b 0x7fd425 0x7fd37e 0x9f5dff 0xa0ac46 0x4bad7a 0x7c544d 0x7c541a 0x9ee448 0x9ed925 0x9ec925 0xa1d34a 0x47d121
#	0x47925c	sync.runtime_notifyListWait+0x11c					/root/src/go.master/src/runtime/sema.go:513
#	0x49146b	sync.(*Cond).Wait+0x8b							/root/src/go.master/src/sync/cond.go:56
#	0x7f776a	github.com/pion/sctp.(*Stream).ReadSCTP+0xaa				/root/go/pkg/mod/github.com/pion/[email protected]/stream.go:108
#	0x7fd424	github.com/pion/datachannel.(*DataChannel).ReadDataChannel+0x64		/root/go/pkg/mod/github.com/pion/[email protected]/datachannel.go:186
#	0x7fd37d	github.com/pion/datachannel.(*DataChannel).Read+0x1d			/root/go/pkg/mod/github.com/pion/[email protected]/datachannel.go:179
#	0x9f5dfe	github.com/anacrolix/torrent.connStatsReadWriter.Read+0x3e		/root/dev-gopath/src/github.com/anacrolix/torrent/conn_stats.go:114
#	0xa0ac45	github.com/anacrolix/torrent.(*rateLimitedReader).Read+0xe5		/root/dev-gopath/src/github.com/anacrolix/torrent/ratelimitreader.go:43
#	0x4bad79	io.ReadAtLeast+0x99							/root/src/go.master/src/io/io.go:331
#	0x7c544c	io.ReadFull+0x32c							/root/src/go.master/src/io/io.go:350
#	0x7c5419	github.com/anacrolix/torrent/peer_protocol.Handshake+0x2f9		/root/dev-gopath/src/github.com/anacrolix/torrent/peer_protocol/handshake.go:119
#	0x9ee447	github.com/anacrolix/torrent.(*Client).connBtHandshake+0x127		/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:894
#	0x9ed924	github.com/anacrolix/torrent.(*Client).initiateHandshakes+0x244		/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:808
#	0x9ec924	github.com/anacrolix/torrent.(*Client).initiateProtocolHandshakes+0x184	/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:708
#	0xa1d349	github.com/anacrolix/torrent.(*Torrent).onWebRtcConn+0x389		/root/dev-gopath/src/github.com/anacrolix/torrent/torrent.go:1577

39 @ 0x44d476 0x4465f3 0x477949 0x4dc6b2 0x4de365 0x4de352 0x55b3a9 0x57c6f8 0x57a431 0x57a5f0 0x938f29 0x47d121
#	0x477948	internal/poll.runtime_pollWait+0x88			/root/src/go.master/src/runtime/netpoll.go:233
#	0x4dc6b1	internal/poll.(*pollDesc).wait+0x31			/root/src/go.master/src/internal/poll/fd_poll_runtime.go:83
#	0x4de364	internal/poll.(*pollDesc).waitRead+0x1e4		/root/src/go.master/src/internal/poll/fd_poll_runtime.go:88
#	0x4de351	internal/poll.(*FD).ReadFromInet4+0x1d1			/root/src/go.master/src/internal/poll/fd_unix.go:250
#	0x55b3a8	net.(*netFD).readFromInet4+0x28				/root/src/go.master/src/net/fd_posix.go:66
#	0x57c6f7	net.(*UDPConn).readFrom+0x1b7				/root/src/go.master/src/net/udpsock_posix.go:52
#	0x57a430	net.(*UDPConn).readFromUDP+0x30				/root/src/go.master/src/net/udpsock.go:149
#	0x57a5ef	net.(*UDPConn).ReadFrom+0x4f				/root/src/go.master/src/net/udpsock.go:158
#	0x938f28	github.com/pion/ice/v2.(*candidateBase).recvLoop+0x1a8	/root/go/pkg/mod/github.com/pion/ice/[email protected]/candidate_base.go:222

36 @ 0x44d476 0x47927d 0x47925d 0x49146c 0x9ded73 0x9f5dff 0xa0ac46 0x4bad7a 0x9f721b 0x9f71eb 0x9eddd6 0x9ee7a5 0x9eb85c 0x47d121
#	0x47925c	sync.runtime_notifyListWait+0x11c				/root/src/go.master/src/runtime/sema.go:513
#	0x49146b	sync.(*Cond).Wait+0x8b						/root/src/go.master/src/sync/cond.go:56
#	0x9ded72	github.com/anacrolix/go-libutp.(*Conn).Read+0x92		/root/go/pkg/mod/github.com/anacrolix/[email protected]/conn.go:151
#	0x9f5dfe	github.com/anacrolix/torrent.connStatsReadWriter.Read+0x3e	/root/dev-gopath/src/github.com/anacrolix/torrent/conn_stats.go:114
#	0xa0ac45	github.com/anacrolix/torrent.(*rateLimitedReader).Read+0xe5	/root/dev-gopath/src/github.com/anacrolix/torrent/ratelimitreader.go:43
#	0x4bad79	io.ReadAtLeast+0x99						/root/src/go.master/src/io/io.go:331
#	0x9f721a	io.ReadFull+0x9a						/root/src/go.master/src/io/io.go:350
#	0x9f71ea	github.com/anacrolix/torrent.handleEncryption+0x6a		/root/dev-gopath/src/github.com/anacrolix/torrent/handshake.go:45
#	0x9eddd5	github.com/anacrolix/torrent.(*Client).receiveHandshakes+0x195	/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:854
#	0x9ee7a4	github.com/anacrolix/torrent.(*Client).runReceivedConn+0xc4	/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:914
#	0x9eb85b	github.com/anacrolix/torrent.(*Client).incomingConnection+0x21b	/root/dev-gopath/src/github.com/anacrolix/torrent/client.go:562

30 @ 0x44d476 0x4465f3 0x477949 0x4dc6b2 0x4de6c5 0x4de6b2 0x55b4c9 0x57c5c5 0x57a431 0x57a5f0 0x938f29 0x47d121
#	0x477948	internal/poll.runtime_pollWait+0x88			/root/src/go.master/src/runtime/netpoll.go:233
#	0x4dc6b1	internal/poll.(*pollDesc).wait+0x31			/root/src/go.master/src/internal/poll/fd_poll_runtime.go:83
#	0x4de6c4	internal/poll.(*pollDesc).waitRead+0x1e4		/root/src/go.master/src/internal/poll/fd_poll_runtime.go:88
#	0x4de6b1	internal/poll.(*FD).ReadFromInet6+0x1d1			/root/src/go.master/src/internal/poll/fd_unix.go:277
#	0x55b4c8	net.(*netFD).readFromInet6+0x28				/root/src/go.master/src/net/fd_posix.go:72
#	0x57c5c4	net.(*UDPConn).readFrom+0x84				/root/src/go.master/src/net/udpsock_posix.go:59
#	0x57a430	net.(*UDPConn).readFromUDP+0x30				/root/src/go.master/src/net/udpsock.go:149
#	0x57a5ef	net.(*UDPConn).ReadFrom+0x4f				/root/src/go.master/src/net/udpsock.go:158
#	0x938f28	github.com/pion/ice/v2.(*candidateBase).recvLoop+0x1a8	/root/go/pkg/mod/github.com/pion/ice/[email protected]/candidate_base.go:222

30 @ 0x44d476 0x45cf12 0x907e31 0x932545 0x47d121
#	0x907e30	github.com/pion/mdns.(*Conn).Query+0x390				/root/go/pkg/mod/github.com/pion/[email protected]/conn.go:139
#	0x932544	github.com/pion/ice/v2.(*Agent).resolveAndAddMulticastCandidate+0x64	/root/go/pkg/mod/github.com/pion/ice/[email protected]/agent.go:761

It may be related to #703, but I'm leaning away from that. I need to run an inuse_space check when this problem shows up.