eth: check snap satelliteness, delegate drop to eth #22235
Merged
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In the current code, a peer is allowed to join both on the
eth
andsnap
protocols. Although both protocol handlers enforces thatsnap-requires-eth
, this is done with a timeout mechanism after the peer was added to all internal structs. Since we allowed a peer to (maliciously) connect with onlysnap
, we needed the snap handler to clean out the peer on disconnect, similar to howeth
does when peer is dropped. This resulted in double-cleanups during normal disconnects since both protocols tries to racily clean.This PR solves the issue by adding doing eth/snap registration in two phases. Snap is registered as a protocol extension in the peerset and eth consumes (or blocks until it can) this registration. Only then will eth proceed. All submodule (downloader, syncer, fetcher) registrations and removals are done on the main
eth
pathways.