packet: only copy bloom filter into beacon when available#162
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The bloom filter is recomputed in the gateway main loop while beacons are built in the radio slot ISR. Copying mid-recompute puts a partial bloom on the air, and a joined node that fails the membership test on such a beacon leaves with MARI_PEER_LOST_BLOOM. Gate the copy on availability so a beacon is not populated from a filter that is mid-recompute. AI-assisted: Claude Opus 4.8
This was referenced Jun 17, 2026
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Problem
The gateway recomputes its bloom filter in the main loop, but beacons are
built in the radio slot ISR. When a beacon is built while a recompute is in
flight, it copies a half-rebuilt filter onto the air. A joined node that fails
the membership test on such a beacon concludes it has been evicted and leaves
with
MARI_PEER_LOST_BLOOM.Under a join storm this is frequent: the gateway sets the filter dirty and
recomputes after every join, so the recompute window is open much of the time,
and a single bad beacon can drop already-joined nodes. They rejoin, trigger
another recompute, and the network bounces instead of settling.
This regressed when the bloom became a mandatory beacon field in
8d20a54,which dropped the prior
mr_bloom_gateway_is_available()guard around the copy.Change
Restore the guard: only copy the filter into the beacon when it is available,
so a beacon is never populated from a filter that is mid-recompute.
Validation
On the testbed, the reason-6 (
MARI_PEER_LOST_BLOOM) disconnects observedduring network formation no longer occur.
Known limitation / follow-up
When the filter is unavailable the copy is skipped, which leaves the beacon's
bloom_filterfield zeroed, and the node side has no empty-filter guard yet.A node-side "treat an all-zero filter as no-info, skip the check" guard (or
gateway-side double-buffering) is a planned follow-up to close that remaining
window fully.