feat(python): outbound raw TCP/UDP sockets + complete the Pyodide FS hooks#142
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Back Python's socket module with host sockets (outbound TCP connect/send/recv, UDP sendto/recvfrom), governed by the network policy + DNS egress guard like the HTTP bridge: - python.rs: SocketConnect/Send/Recv/Close + UdpCreate/Sendto/Recvfrom RPC methods, port/socketId wire fields, and Socket*/Udp* response payloads - execution.rs: handle_python_socket_rpc_request opens host TcpStream/UdpSocket per process (require_network_access + filter_dns_safe_ip_addrs), short read timeout so a recv RPC never stalls the shared event loop - state.rs: per-process PythonHostSocket registry - runner: socket bridge methods + a socket.socket shim that polls recv/recvfrom to emulate blocking semantics Listeners (bind/listen/accept) are out of scope — outbound only. Test: python_runtime_supports_raw_tcp_and_udp_sockets drives TCP + UDP echo servers through Python's stdlib socket module. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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This was referenced Jun 28, 2026
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FS hooks: symlink, readlink, lstat, and setattr->host (chmod/chown/utimes) — every Emscripten node_op/stream_op. lstat lets pre-existing host symlinks be detected as link nodes; setattr is host-first; chmod/utimes mirror to the host shadow only when the entry already exists there (never creating empty stubs); chown applies uid/gid independently (keeps the unchanged side). Socket hardening: per-process registry bounded by the VM max_sockets limit, read+write timeouts so recv/send can't wedge the shared loop (recv uses a short host poll + a capped guest-side backoff), connect/sendto routed through the loopback-connect gate (blocks DNS-rebind to sidecar-local ports), and host errors mapped to the right OSError/errno. Tests: python_runtime_supports_raw_tcp_and_udp_sockets, python_runtime_supports_symlink_readlink_and_metadata (now also covers a host-preexisting symlink); full python_suite green. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Two related pieces that finish out the guest-Python runtime, combined into one PR (two commits).
1. Raw TCP + UDP sockets
Backs Python's stdlib
socketmodule with host sockets — same synchronous-bridge + network-policy model as the HTTP/DNS bridge.connect/send/sendall/recv/close) and UDP (sendto/recvfrom/close),settimeout/setblocking.require_network_access+ the DNS egress guard (resolve-once-and-pin, restricted ranges refused).recvRPC never stalls the shared event loop (the Python shim re-polls to emulate blocking).bind/listen/accept) are out of scope — outbound only.2. Complete the Emscripten FS hooks
Closes the remaining gaps so the custom FS backend implements every node_op/stream_op the FS layer dispatches (verified against MEMFS's
ops_table).symlink(was anENOSYSstub) andreadlink(was missing, no link-node) now work.setattrnow propagateschmod/chown/utimesto the host VFS (was in-isolate only).Tests
python_runtime_supports_raw_tcp_and_udp_sockets— TCP + UDP echo servers through stdlibsocket.python_runtime_supports_symlink_readlink_and_metadata—os.symlink/readlink/path.islink/chmod(host cross-checked)/utime.python_suitestays green.Supersedes #140 and #141 (closed in favor of this combined PR).
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