* [relay] Signal relay disconnects through the conn context
AddCloseListener deduplicated listeners by comparing
reflect.ValueOf(callback).Pointer(). For a method value that pointer is
the address of the compiler-generated wrapper, not an identity bound to
the receiver, so every peer's w.onRelayClientDisconnected compared equal.
All peers on the home relay register under the same connectionURL key, so
only the first registration survived and the rest were silently dropped.
On a relay disconnect those peers were never notified: statusRelay stayed
connected and the reconnect guard never fired. The relayed net.Conn itself
was closed by closeAllConns, so nothing leaked, but the peer state machine
did not learn about it. Foreign relays had the same defect scoped to the
peers sharing that server.
Rather than fixing the deduplication, drop the peer-level listener registry
entirely. A relayed Conn now exposes Context(), cancelled when the
connection is torn down, with a cancellation cause naming the reason. This
is the same shape quic-go uses for its Conn and Stream types, and it
removes the whole class of problems around listener identity, lifetime and
deregistration: the signal belongs to the resource instead of a side table.
WorkerRelay watches that context in a goroutine whose lifetime matches the
connection. A watcher that wakes up for a superseded connection compares
the conn pointer against the current one and returns without touching the
state machine, so a fast relay reconnect cannot have a stale watcher tear
down the connection that replaced it.
Client.SetOnDisconnectListener stays: it is server-level and drives the
reconnect guard and foreign relay eviction, unrelated to peers.
handleRelayReady also checks the conn context, closing the race where the
relay dies between OpenConn and the readiness handoff and the peer would
otherwise build a WireGuard endpoint over a dead connection.
TestNotifierDoubleAdd covered the removed mechanism and is gone.
TestForeignAutoClose asserted nothing (both branches logged); it now waits
for the relay to leave the client map and fails if it does not.
* [relay] Fix build: return the concrete conn from Client.OpenConn
OpenConn now returns *Conn, but it still went through connContainer.netConn(),
which widens to net.Conn. The helper had one caller and only existed to produce
the interface value the signature no longer wants, so return container.conn
directly and drop it.
* [relay] Assert the local-close cancellation cause explicitly
The local-close test only rejected ErrServerDisconnected, so it would also
have passed for ErrPeerDisconnected or a bare context.Canceled. closeConn
cancels with net.ErrClosed, so assert that.
* [client] Ignore relay disconnects from superseded connections
The relayed conn watcher compared the conn pointer under relayLock, released
it, and only then tore the connection down. A new offer could install its
replacement in that window, so a watcher that validated the old pointer went
on to close the proxy of the connection that had already replaced it and
report the peer as disconnected while it was up.
Move the decision to where the teardown happens. Conn records which relayed
connection the current proxy was built from, and onRelayDisconnected takes the
connection the signal belongs to and drops it under conn.mu when it is no
longer the current one. Check and effect are now in the same critical section,
so the verdict cannot go stale before it is acted on.
This also covers the proxy read loops, whose disconnect listener took no
argument and had the same defect: it now names the connection it belongs to.
The WG timeout path keeps passing nil, since it deliberately tears down
whatever is current.
* [client] Bind the relayed conn reference to the proxy swap
relayedConnRef was set at the top of the readiness path, but wgProxyRelay only
changes at the end, in setRelayedProxy. The two failure returns in between —
newProxy and ConfigureWGEndpoint — left the reference pointing at a connection
that never became active while the old proxy was still installed. A disconnect
of that old, live relay would then be dismissed as belonging to a superseded
connection and never cleaned up.
Set the reference in setRelayedProxy, next to the proxy it belongs to. Both
success paths go through it and neither failure path does, so no failure branch
has to remember to roll anything back.
Read the relay instance URL and IP atomically to prevent reconnects from mixing values from different connections. Extend existing connection and offer/answer logs with relay URLs and IPs to help trace mismatched advertisements.
Losing the last network only flipped the availability state: the dead management, signal and relay sockets stayed silently connected until their own timeouts, so the client kept reporting Connected with no network at all.
Introduce client/netevents with a Manager that ties the availability state, the connection sweeper and the status recorder together, and move the netstate and netsweep packages under it (netsweep renamed to sweep). SetNetworkAvailable(false) now also sweeps the registered connections so their owners redial and the listener reaches the NoNetwork state.
The Android and iOS bindings own a Manager instance and inject it through the constructors; consumers hold the concrete *Manager whose nil zero value reports always-online and never sweeps, with interfaces kept only as parameter contracts. The relay guard settle wait moved into the Manager as WaitSettled, removing the netevents import from the relay package.
On network changes the client restarted the whole engine. That is heavy-handed and slow: it tears down working state to recover from a transition the engine could handle itself. This replaces the restart with proper network event handling.
Suspend the retry loops while no network is available. Instead of burning through backoff intervals against an unreachable network, the reconnection loops park until the OS reports a usable network again.
Reconnect immediately on a network switch. When the OS hands us a new network, connections bound to the old one are swept and re-dialed right away, rather than waiting for a timeout to notice they are dead.
* [relay] evict foreign client cache on disconnect
When a foreign relay's TCP connection drops, the manager's
onServerDisconnected handler only triggered reconnect logic for the
home server; the disconnected foreign entry stayed in the relayClients
cache. Subsequent OpenConn calls reused the closed client until the
60-second cleanup tick evicted it, breaking peer connectivity through
that relay for up to a minute.
Evict the foreign entry from the cache on disconnect so the next
OpenConn dials a fresh client.
Also:
- Make the reconnect backoff cap configurable via WithMaxBackoffInterval
ManagerOption; the previous hard-coded 60s constant forced
TestAutoReconnect to sleep ~61s. Test now polls Ready() and finishes
in ~2s.
- Add NB_HOME_RELAY_SERVERS env var that overrides the relay URL list
received from management, so a peer can be pinned to a specific home
relay (used by the netbird-conn-lab Edge 4 reproducer).
* [client] treat empty NB_HOME_RELAY_SERVERS as unset
Returning (urls=[], ok=true) when the env var contained only separators or
whitespace caused callers to wipe the mgmt-provided relay list, leaving the
peer with no relays. Treat a parsed-empty result the same as an unset env.
Zoltan Papp