New integration scenario verifying the early-gate silent-drop behavior
of the inbound max_peers admission check at sustained scale, using the
existing 5-node mesh topology with one node's node.limits.max_peers
lowered to 1. This forces 2 of the cap'd node's 3 configured peers
into a sustained denied state, and asserts via tcpdump that no Msg2
responses go back to those denied peers across a 60s capture window.
A background load-driver restarts the denied peer containers every 15s
to reset their auto-reconnect exponential backoff (5s base / 300s cap),
producing fresh Msg1 bursts each cycle. Without this loop the gate
fires ~3-4 times per denied peer in a 60s window; with restarts the
observed rate is 15 per denied peer (~30 total firings), high enough
that any Msg2 leakage would be caught with strong statistical
confidence.
Local run on this branch: cap'd node-c converged to peer_count=1 with
node-b admitted; nodes d and e sustained-retried as denied; tcpdump
captured 30 inbound Msg1 (len 84) packets from the denied pair and 0
outbound Msg2 (len 104) packets, with final peer_count unchanged.
Files:
testing/static/scripts/admission-cap-test.sh — new test script with
inject-config subcommand (sets node.limits.max_peers) and a
3-phase test driver (converge, capture-with-load, per-peer assert)
testing/ci-local.sh — register admission-cap as a new suite category
(ADMISSION_SUITES), wire run_admission_cap function, add to
run_suite dispatch, list_suites, and the default integration sweep
Together with the existing unit-level coverage in src/node/tests/unit.rs
(handle_msg1_silent_drops_at_cap_for_new_peer with mock-transport Msg2
discriminator, and handle_msg1_admits_existing_peer_at_cap as the
bypass regression guard), the gate's silent-drop behavior is now
verified both at single-firing wire-observable resolution and at
sustained multi-firing cross-process scale.
