0f7d4ee4e8 p2p: Use different inbound inv timer per network (Martin Zumsande)
94db966a3b net: use generic network key for addrcache (Martin Zumsande)
Pull request description:
Currently, `NextInvToInbounds` schedules each round of `inv` at the same time for all inbound peers. It's being done this way because with a separate timer per peer (like it's done for outbounds), an attacker could do multiple connections to learn about the time a transaction arrived. (#13298).
However, having a single timer for inbounds of all networks is also an obvious fingerprinting vector: Connecting to a suspected pair of privacy-network and clearnet addresses and observing the `inv` pattern makes it trivial to confirm or refute that they are the same node.
This PR changes it such that a separate timer is used for each network.
It uses the existing method from `getaddr` caching and generalizes it to be saved in a new field `m_network_key` in `CNode` which will be used for both `getaddr` caching and `inv` scheduling, and can also be used for any future anti-fingerprinting measures.
ACKs for top commit:
sipa:
utACK 0f7d4ee4e8
stratospher:
reACK 0f7d4ee.
naiyoma:
Tested ACK 0f7d4ee4e8
danielabrozzoni:
reACK 0f7d4ee4e8
Tree-SHA512: e197c3005b2522051db432948874320b74c23e01e66988ee1ee11917dac0923f58c1252fa47da24e68b08d7a355d8e5e0a3ccdfa6e4324cb901f21dfa880cd9c
a33bd767a3