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Add a vmtest that brings up two gokrazy nodes A and B behind two
One2OneNAT networks (so direct UDP works in both directions and any
slowness can't be blamed on NAT traversal), establishes a WireGuard
tunnel A → B with TSMP, then rotates B's disco key four times and
asserts that the data plane recovers in both directions after each
rotation. All pings are TSMP (the data-plane ping; disco pings would
not exercise the WireGuard tunnel itself).
The five pings:
1. A → B (initial; brings up the tunnel; 30s budget)
2. B → A after rotate (LocalAPI rotate-disco-key debug action)
3. A → B after rotate (LocalAPI)
4. B → A after restart (SIGKILL; gokrazy supervisor respawns)
5. A → B after restart (SIGKILL)
Each post-rotation ping gets a 15-second budget. Two unavoidable
multi-second waits dominate today:
- The rotate-then-a→b phase takes ~10s on main because of LazyWG.
After B's WantRunning bounce, B's wgengine resets its
sentActivityAt/recvActivityAt maps and trims A out of the
wireguard-go config as an "idle peer"; B only re-adds A on
inbound activity, by which point A's first few TSMP packets
have been silently dropped at B's tundev. The
bradfitz/rm_lazy_wg branch removes that trimming entirely
(verified locally: this phase drops to <100ms there).
- The restart phases take ~5s for wireguard-go's RekeyTimeout
handshake retry. After SIGKILL+respawn the first WG handshake
init from the restarted node sometimes goes into the void
(likely the brief peer-removed window in the receiver's
two-step maybeReconfigWireguardLocked reconfig during which
the peer is absent from wireguard-go), and wg-go's 5s+jitter
retransmit timer is the next opportunity to retry. That retry
succeeds and the staged TSMP packet flushes. Intrinsic to the
protocol's retransmit policy.
Once LazyWG is removed and the first-handshake-after-reconfig race
is fixed, the budget should drop to 5s.
Supporting changes:
ipn/ipnlocal: DebugRotateDiscoKey now toggles WantRunning off and
back on after rotating the disco key. magicsock.Conn.RotateDiscoKey
only resets local disco state; without also dropping wireguard-go
session keys, peers keep encrypting with their stale per-peer
session against us until their rekey timer fires (WireGuard has no
data-plane signaling to invalidate sessions). Bouncing WantRunning
runs the engine through Reconfig(empty) → authReconfig, which
drops every peer's WG session so the next packet either way
triggers a fresh handshake.
ipn/ipnlocal, ipn/localapi: add a debug-only "peer-disco-keys"
LocalAPI action ([LocalBackend.DebugPeerDiscoKeys]) that returns
a map[NodePublic]DiscoPublic from the current netmap. Tests reach
it via [local.Client.DebugResultJSON]. We do not surface disco
keys via [ipnstate.PeerStatus] because adding a non-comparable
[key.DiscoPublic] field there breaks reflect-based test helpers
(e.g. TestFilterFormatAndSortExitNodes' use of cmp.Diff), and
general LocalAPI clients have no need for disco keys. Since the
debug LocalAPI is gated behind the ts_omit_debug build tag, this
endpoint is automatically stripped from small binaries.
cmd/tta: add /restart-tailscaled handler (Linux-only, via /proc walk)
to drive the SIGKILL phase. On gokrazy the supervisor respawns
tailscaled within a second.
tstest/integration/testcontrol: add Server.AllOnline. When set,
every peer entry in MapResponses is marked Online=true. Several
disco-key handling fast paths in controlclient and wgengine
(removeUnwantedDiscoUpdates, removeUnwantedDiscoUpdatesFromFull
NetmapUpdate, the wgengine tsmpLearnedDisco fast path) only fire
for online peers; without this flag, tests exercising disco-key
rotation only hit the offline-peer code paths, which mask issues
and are several seconds slower in this scenario. Finer-grained
per-node online tracking can be added later.
tstest/natlab/vmtest: add Env.RotateDiscoKey,
Env.RestartTailscaled, Env.PeerDiscoKey, Node.Name, an
[AllOnline] EnvOption that plumbs through to
testcontrol.Server.AllOnline, and an exported
Env.Ping(from, to, type, timeout). Ping replaces the unexported
helper so callers can specify both a ping type (PingDisco for
warming peer state, PingTSMP for asserting end-to-end
connectivity) and a deadline. PeerDiscoKey returns its LocalAPI
error so callers inside tstest.WaitFor can retry transient
failures rather than fataling the test.
Updates #12639
Updates #13038
Change-Id: I3644f27fc30e52990ba25a3983498cc582ddb958
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>