The guard refused to start an AmneziaWG endpoint whose detour chain reached a
WireGuard one, and refused silently: not an error, just started=false, after
which every dial failed with "WireGuard is not ready yet". A selector hook went
further and suspended an already-working node the moment its group switched to a
WireGuard member.
It existed because AmneziaWG inside WireGuard hung the kernel on Android. We do
not ship Android, upstream dropped the guard once the cause was gone, and the
cure landed here yesterday — the ClientBind reserved-gate plus the submodule pin
that carries its twin. So the tree held both the cure and the prohibition on
using it, and the configuration simply did not come up while looking like a node
that "just does not work".
Also takes the two fixes that belong with it. ClientBind.conn was read on a
lock-free fast path and written under a mutex; upstream found that race with the
same end-to-end test we wrote yesterday, so we had taken one half of a pair
again. And the outer WireGuard UDP socket forced DF, unlike direct, hysteria and
tuic — with encapsulation the datagram regularly exceeds the path MTU and the
kernel drops it instead of fragmenting, a symptom indistinguishable from the bug
we spent yesterday on.
The race needed its own test: the existing e2e run did not flag it under -race
even at -count=15. Eight goroutines over both connect branches reproduce it
deterministically, naming the lock-free read and the guarded write.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
omarandClaude Opus 5