Multipath: assign fresh dcids to paths still waiting for one - #519
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aswanthk777 wants to merge 1 commit into
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Multipath: assign fresh dcids to paths still waiting for one#519aswanthk777 wants to merge 1 commit into
aswanthk777 wants to merge 1 commit into
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A client typically calls add_path() from the connection-established callback, which fires before the peer's post-handshake NEW_CONNECTION_ID flight has been processed. Such a path gets dcid_seq=None, and the NEW_CONNECTION_ID handler only re-assigned dcids to paths whose dcid was retired — a path waiting for its FIRST dcid was never revisited. Since select_send_path skips dcid-less paths for probing, the path could never send its PATH_CHALLENGE, never validated, and never carried traffic. Fix: when NEW_CONNECTION_ID frames arrive, also assign unused dcids to any path with dcid_seq=None. (cherry picked from commit b7c5114d20ebf9b9ab74cc5f9befd688c5aadd94)
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A client typically calls add_path() from the connection-established
callback, which fires before the peer's post-handshake NEW_CONNECTION_ID
flight has been processed. Such a path gets dcid_seq=None, and the
NEW_CONNECTION_ID handler only re-assigned dcids to paths whose dcid was
retired — a path waiting for its FIRST dcid was never revisited. Since
select_send_path skips dcid-less paths for probing, the path could never
send its PATH_CHALLENGE, never validated, and never carried traffic.
Fix: when NEW_CONNECTION_ID frames arrive, also assign unused dcids to
any path with dcid_seq=None.
Found while building a multipath datagram tunnel on TQUIC: a path added from
on_conn_establishedstayed silent forever (no PATH_CHALLENGE ever sent, 0% of traffic) because the callback fires before the peer's NEW_CONNECTION_ID flight is processed. With this fix the path validates as soon as the first NCID arrives.🤖 Generated with Claude Code
https://claude.ai/code/session_01LqZK49rKWmBNsihzCrsbgD