* [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.
* [client] Suppress ICE signaling and periodic offers in force-relay mode
When NB_FORCE_RELAY is enabled, skip WorkerICE creation entirely,
suppress ICE credentials in offer/answer messages, disable the
periodic ICE candidate monitor, and fix isConnectedOnAllWay to
only check relay status so the guard stops sending unnecessary offers.
* [client] Dynamically suppress ICE based on remote peer's offer credentials
Track whether the remote peer includes ICE credentials in its
offers/answers. When remote stops sending ICE credentials, skip
ICE listener dispatch, suppress ICE credentials in responses, and
exclude ICE from the guard connectivity check. When remote resumes
sending ICE credentials, re-enable all ICE behavior.
* [client] Fix nil SessionID panic and force ICE teardown on relay-only transition
Fix nil pointer dereference in signalOfferAnswer when SessionID is nil
(relay-only offers). Close stale ICE agent immediately when remote peer
stops sending ICE credentials to avoid traffic black-hole during the
ICE disconnect timeout.
* [client] Add relay-only fallback check when ICE is unavailable
Ensure the relay connection is supported with the peer when ICE is disabled to prevent connectivity issues.
* [client] Add tri-state connection status to guard for smarter ICE retry (#5828)
* [client] Add tri-state connection status to guard for smarter ICE retry
Refactor isConnectedOnAllWay to return a ConnStatus enum (Connected,
Disconnected, PartiallyConnected) instead of a boolean. When relay is
up but ICE is not (PartiallyConnected), limit ICE offers to 3 retries
with exponential backoff then fall back to hourly attempts, reducing
unnecessary signaling traffic. Fully disconnected peers continue to
retry aggressively. External events (relay/ICE disconnect, signal/relay
reconnect) reset retry state to give ICE a fresh chance.
* [client] Clarify guard ICE retry state and trace log trigger
Split iceRetryState.attempt into shouldRetry (pure predicate) and
enterHourlyMode (explicit state transition) so the caller in
reconnectLoopWithRetry reads top-to-bottom. Restore the original
trace-log behavior in isConnectedOnAllWay so it only logs on full
disconnection, not on the new PartiallyConnected state.
* [client] Extract pure evalConnStatus and add unit tests
Split isConnectedOnAllWay into a thin method that snapshots state and
a pure evalConnStatus helper that takes a connStatusInputs struct, so
the tri-state decision logic can be exercised without constructing
full Worker or Handshaker objects. Add table-driven tests covering
force-relay, ICE-unavailable and fully-available code paths, plus
unit tests for iceRetryState budget/hourly transitions and reset.
* [client] Improve grammar in logs and refactor ICE credential checks
