feat(webrtc): run aiortc RTCPeerConnection over UdpMux (attach_muxed_connection) - #1448
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@seetadev @acul71 Rebased on latest main. This PR runs a full aiortc |
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…_attr Dialer v1 ICE-credential fields on the aioice Connection and the listener's inbound _validate_peer_identity replacement now assert the slot exists before writing, matching the pattern introduced in libp2p#1448. Refs libp2p#1437
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…_attr Dialer v1 ICE-credential fields on the aioice Connection and the listener's inbound _validate_peer_identity replacement now assert the slot exists before writing, matching the pattern introduced in libp2p#1448. Refs libp2p#1437
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…_attr Dialer v1 ICE-credential fields on the aioice Connection and the listener's inbound _validate_peer_identity replacement now assert the slot exists before writing, matching the pattern introduced in libp2p#1448. Refs libp2p#1437
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tox commands_pre installed no extras, so aiortc was absent in CI and every test under tests/core/transport/webrtc was skipped on GitHub. aiortc 1.15 is pure Python and its native deps (av, pylibsrtp) ship manylinux/win wheels, so no system packages are needed. Refs libp2p#1437
…oles The listener's inbound completion was a stub: after ICE it logged and returned, so no inbound connection ever reached the handler. dial() was broken too - get_remote_fingerprint read attributes aiortc does not have. - listener: own a trio nursery (system task, like TCP), hop asyncio->trio without blocking the loop, run Noise XX as *initiator* (spec: server initiates, dialer responds), then hand the authenticated connection to the handler; bound in-flight unauthenticated inbounds. - transport.dial(): Noise responder; verify authenticated peer ID against /p2p/ after the handshake. - noise: role-ordered prologue (dialer fingerprint, then server); PatternXX.handshake_outbound(remote_peer=None) skips only the ID equality check; DataChannelReadWriter.read(n) honours n (the Noise packet reader asks for the 2-byte prefix alone). - helpers: get_remote_fingerprint reads pc.sctp.transport._ssl peer cert; noise send waits for data channel 0 to open. - tests: transport-level dial->listen->stream echo loopback, wrong /p2p/ rejection, e2e Noise role test, buffered read test, fingerprint test. Refs libp2p#1437
- Frame Noise handshake bytes as uvarint-prefixed webrtc.pb.Message stream frames on channel 0 (spec 'Multiplexing'; what go/js do) instead of raw bytes - required for interop; py<->py was symmetric so tests did not notice. - Listener: guard the handler call - the nursery lives in a trio system task, so an escaping exception aborted the whole trio run. - dial(): bound the Noise phase (responder's first step is a read) with handshake_timeout; close the PC on every failure path, not just the two explicit mismatches; do not pass config.ice_servers (previously no STUN servers were used; the default Google STUN added ~5s to offline dials). - Tests: framing round-trip/chunking/FIN/malformed, handler-exception regression. Refs libp2p#1437
…string Review follow-up: the module docstring still described the prologue as local_fp || remote_fp; it is dialer_fp || server_fp (spec role order), matching build_noise_prologue. Also bound the dialer's wait_for_connected with config.handshake_timeout like the listener does. Refs libp2p#1437
…connection) aiortc has no injection point for an external ICE connection, so a listener that demuxes on one UDP port could not use RTCPeerConnection on top of UdpMux. Add attach_muxed_connection(pc, mux, conn): swaps the gatherer/transport aioice.Connection for the mux-backed one, rebinds the DTLS _recv/_send that RTCIceTransport captured at construction, and keeps the mux tables in sync on ICE state changes. UdpMux fixes found while validating that path with a real peer: - mark _local_candidates_start so aiortc's gather() from setLocalDescription is a no-op (it bound extra sockets and appended their candidates to the answer); - STUN responses/indications carry no USERNAME - route them by address, and learn peer addresses from inbound checks and outbound sends; - unregister(ufrag) also drops the addresses learned for that protocol; - STUN-shaped-but-malformed datagrams go straight to the connection's data path (StunProtocol only catches ValueError, so struct.error escaped). Test: mux-backed server PC vs plain aiortc client PC on loopback - answer advertises only the shared port, ICE/DTLS/SCTP connect, data flows both ways, tables empty after close. webrtc extra now aiortc>=1.15. Refs libp2p#1437
… mux test - _learn_addr: latest connection wins for a reused (ip, port) (pion behaviour) so a redial from the same socket reaches its new connection; cap learned addresses per protocol (unauthenticated STUN with a live ufrag from many source ports must not grow the table without bound). - test_pc_over_mux: bind the mux on 0.0.0.0 and advertise a real host address - a 127.0.0.1-bound socket cannot reply to a LAN-bound peer socket on Windows (WinError 1231), which Linux's weak-host model hid. Refs libp2p#1437
A hung close() after a primary failure would outlive asyncio.wait_for and be killed by pytest-timeout, reported as an xdist 'worker crashed' that hides the real error (seen on Windows CI). Refs libp2p#1437
…ection) pc.close() deadlocks on Windows CPython 3.12/3.13: DTLS queues its close_notify datagram, transport.close() runs with that write in flight and defers connection_lost to the write callback, but _ProactorDatagramTransport._loop_writing early-returns on _conn_lost - the deferred connection_lost is never delivered and aioice's StunProtocol.close() awaits its closed-future forever (confirmed via task/transport dumps on CI: closing=True, write_fut finished, closed.done=False). close_peer_connection(pc) bounds close() and, on timeout, abort()s the lingering aioice transports - _force_close delivers connection_lost unconditionally - then lets close() finish. Used in the PC-over-mux test; production call sites switch in the listener PR. Refs libp2p#1437
Writing a wrong - or upgraded-away - private/mangled attribute name is a silent no-op: setattr creates a new attribute the library never reads and the failure only surfaces far downstream (the SDP-fingerprint invariant test, an ICE that binds extra sockets). Assert hasattr at the write so it fails at the line that caused it, and so an aiortc/aioice upgrade that renames or drops a slot breaks loudly at construction. Applied to the DTLS cert pin (_RTCPeerConnection__certificates, ca8331f), the attach_muxed_connection injection points, and add_ice_connection's aioice fields. Refs libp2p#1437
…Windows Windows surfaces an ICMP port-unreachable for a datagram we sent (a keepalive to a peer that just closed) as WSAECONNRESET on the shared socket's next recv, and the proactor loop does not re-arm reading after error_received - the mux went deaf for every other peer (seen in CI as '[WinError 10054]' followed by the next dial's ICE timing out). Disable that behaviour with SIO_UDP_CONNRESET on the mux socket; no-op elsewhere. Refs libp2p#1437
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…_attr Dialer v1 ICE-credential fields on the aioice Connection and the listener's inbound _validate_peer_identity replacement now assert the slot exists before writing, matching the pattern introduced in libp2p#1448. Refs libp2p#1437
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…1449) Lands the full WebRTC-Direct stack for #1437: - CI webrtc extra, inbound wiring + spec Noise roles, UdpMux bridge - STUN-dispatch v1 listener + v1 dialer (spec path default) - HTTP POST /sdp harness opt-in via enable_sdp_http_harness - Review follow-ups: rate limit, ice_servers=[], actpass + DTLS server role, 0.0.0.0 concrete advertising, README note Supersedes #1446, #1447, #1448. Refs #1437
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What
Second step for #1437: lets a full aiortc
RTCPeerConnection(DTLS + SCTP) run over aUdpMux-backed ICE connection, so a listener can demux concurrent inbound dials on one UDP port.attach_muxed_connection(pc, mux, conn)(_aiortc_helpers.py): call aftercreateDataChannel, before anyset*Description. SwapsiceGatherer._connection/iceTransport._connectionfor the mux-backedaioice.Connectionand rebindsiceTransport._recv/_send(aiortc captures those at construction — without this DTLS keeps talking to the orphaned connection). Registers/unregisters the peer address on ICE state changes.UdpMuxfixes surfaced by driving it with a real peer:add_ice_connectionalso sets_local_candidates_start, so aiortc'sgather()(issued fromsetLocalDescription) is a no-op instead of binding extra sockets and appending their candidates to the answer.USERNAME— they were dropped. Now routed by address; addresses are learned from inbound checks and from outbound sends (pion-style), so DTLS racing ahead of our ICEcompletedstill routes.unregister(ufrag)drops the learned addresses for that protocol.StunProtocol.datagram_receivedonly catchesValueError, sostruct.errorescaped the loop callback).webrtcextra:aiortc>=1.15,<2.0(what this was validated against; 1.15 also fixed the credential-forwarding bug from spike: aiortc ICE mux / STUN USERNAME exposure for webrtc-direct v2 listener #1352).Tests
test_udp_mux.py: mux-backed server PC vs plain aiortc client PC on loopback — answer advertises only the shared port + our creds +a=setup:passive, ICE/DTLS/SCTP connect, data flows both ways, mux tables empty after close. Plus addr-learning / unregister / malformed-STUN cases.tests/core/transport/webrtc: 187 passed; mypy/pyrefly clean.Stacked on #1447 → #1446.
Refs #1437