## Description
Internalize some libs. This reduces the amount ot public API tendermint is supporting. The moved libraries are mainly ones that are used within Tendermint-core.
This cleans up the `Router` code and adds a bunch of tests. These sorts of systems are a real pain to test, since they have a bunch of asynchronous goroutines living their own lives, so the test coverage is decent but not fantastic. Luckily we've been able to move all of the complex peer management and transport logic outside of the router, as synchronous components that are much easier to test, so the core router logic is fairly small and simple.
This also provides some initial test tooling in `p2p/p2ptest` that automatically sets up in-memory networks and channels for use in integration tests. It also includes channel-oriented test asserters in `p2p/p2ptest/require.go`, but these have primarily been written for router testing and should probably be adapted or extended for reactor testing.
This renames `PeerAddress` to `NodeAddress`, moves it and `NodeID` into a separate file `address.go`, adds tests for them, and fixes a bunch of bugs and inconsistencies.
This revises the new P2P `Transport` interface and does some preliminary code cleanups and simplifications.
The major change here is to add `Connection.Handshake()` for performing node handshakes (once the stream transport API is implemented, this can be done entirely independent of the transport). This moves most of the handshaking logic into the `Router`, such as prevention of head-of-line blocking, validation of peer's `NodeInfo`, controlling timeouts, and so on. This significantly simplifies transports, completely removes the need for internal goroutines, and shares common logic across all transports. This also allows varying the handshake `NodeInfo` across peers, e.g. to vary `ListenAddr`. Similarly, connection filtering is also moved into the switch/router so that it can be shared between transports.
Fixes#5981, which was caused by changes in Router behavior after the introduction of the peer manager, leading to a race condition that could halt the test.
This is a temporary measure, I'll start tightening up the new P2P core tomorrow and write "real" tests with better test infrastructure.
This patches over a test data race where the logger would try to read struct internals via `reflect` while these were concurrently modified (specifically `MemoryTransport.closeOnce`).
This test occasionally fails because the peer is already stopped. It is unclear to me exactly what this test is supposed to do, since calling `FlushStop()` will stop the peer, but the test asserts that the peer shouldn't have been stopped by `FlushStop()` since calling `Stop()` afterwards will error in that case.
The current PEX reactor will be removed in the new P2P stack anyway.
Fixes#5998. Sometimes the connection returns "use of closed network connection" instead, so for now we just accept any error. The switch is not long for this world anyway.
This changes the new prototype PEX reactor to resolve peer address URLs into IP/port PEX addresses itself. Branched off of #5974.
I've spent some time thinking about address handling in the P2P stack. We currently use `PeerAddress` URLs everywhere, except for two places: when dialing a peer, and when exchanging addresses via PEX. We had two options:
1. Resolve addresses to endpoints inside `PeerManager`. This would introduce a lot of added complexity: we would have to track connection statistics per endpoint, have goroutines that asynchronously resolve and refresh these endpoints, deal with resolve scheduling before dialing (which is trickier than it sounds since it involves multiple goroutines in the peer manager and router and messes with peer rating order), handle IP address visibility issues, and so on.
2. Resolve addresses to endpoints (IP/port) only where they're used: when dialing, and in PEX. Everywhere else we use URLs.
I went with 2, because this significantly simplifies the handling of hostname resolution, and because I really think the PEX reactor should migrate to exchanging URLs instead of IP/port numbers anyway -- this allows operators to use DNS names for validators (and can easily migrate them to new IPs and/or load balance requests), and also allows different protocols (e.g. QUIC and `MemoryTransport`). Happy to discuss this.
Sam Kleinman
Marko
Callum Waters
Aleksandr Bezobchuk
Ismail Khoffi
Anton Kaliaev
Erik Grinaker