Prevent channel_id collisions - #3337
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If the first DB write of a channel fails, we want to abort the channel immediately, otherwise our state may be unusable. If for some reason we already have a channel (for example because of a partial restore from a DB backup), we want to avoid overwriting this state as well.
We add a global, concurrent map that keeps track of every temporary and final `channel_id` being used. We always add to this map before creating channel actors or transitioning to a final `channel_id` (and thus before storing channel data in the DB). We only remove from that map when a channel actor dies: no other channel can be associated with the corresponding temporary or final `channel_id` since the channel was created after registering the IDs.
pm47
approved these changes
Jul 28, 2026
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If the first DB write of a channel fails, we want to abort the channel immediately, otherwise our state may be unusable. If for some reason we already have a channel (for example because of a partial restore from a DB backup), we want to avoid overwriting this state as well. This is implemented in the first commit of this PR.
In the second commit, we prevent
channel_idcollisions across peers: while highly unlikely (since they depend on the actual funding transaction for single-funding and the random revocation basepoint for dual-funding), they would trigger a force-close. We thus add a global, concurrentchannel_idmap, which can be reused in the future for accounting.