Merge bitcoin/bitcoin#22387: Rate limit the processing of rumoured addresses

a4bcd687c934d47aa3922334e97e579caf5f8124 Improve tests using statistics (John Newbery)
f424d601e1b6870e20bc60f5ccba36d2e210377b Add logging and addr rate limiting statistics (Pieter Wuille)
b4ece8a1cda69cc268d39d21bba59c51fa2fb9ed Functional tests for addr rate limiting (Pieter Wuille)
5648138f5949013331c017c740646e2f4013bc24 Randomize the order of addr processing (Pieter Wuille)
0d64b8f709b4655d8702f810d4876cd8d96ded82 Rate limit the processing of incoming addr messages (Pieter Wuille)

Pull request description:

  The rate at which IP addresses are rumoured (through ADDR and ADDRV2 messages) on the network seems to vary from 0 for some non-participating nodes, to 0.005-0.025 addr/s for recent Bitcoin Core nodes. However, the current codebase will happily accept and process an effectively unbounded rate from attackers. There are measures to limit the influence attackers can have on the addrman database (bucket restrictions based on source IPs), but still - there is no need to permit them to feed us addresses at a rate that's orders of magnitude larger than what is common on the network today, especially as it will cause us to spam our peers too.

  This PR implements a [token bucket](https://en.wikipedia.org/wiki/Token_bucket) based rate limiter, allowing an average of 0.1 addr/s per connection, with bursts up to 1000 addresses at once. Whitelisted peers as well as responses to GETADDR requests are exempt from the limit. New connections start with 1 token, so as to not interfere with the common practice of peers' self-announcement.

ACKs for top commit:
  laanwj:
    ACK a4bcd687c934d47aa3922334e97e579caf5f8124
  vasild:
    ACK a4bcd687c934d47aa3922334e97e579caf5f8124
  jnewbery:
    ACK a4bcd687c934d47aa3922334e97e579caf5f8124
  jonatack:
    ACK a4bcd687c934d47aa3922334e97e579caf5f8124

Tree-SHA512: b757de76ad78a53035b622944c4213b29b3b55d3d98bf23585afa84bfba10808299d858649f92269a16abfa75eb4366ea047eae3216f7e2f6d3c455782a16bea

1 files changed, 2 insertions, 0 deletions

diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 3013c76825..083ba31b71 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -242,6 +242,8 @@ static RPCHelpMan getpeerinfo()
                 heights.push_back(height);
             }
             obj.pushKV("inflight", heights);
+            obj.pushKV("addr_processed", statestats.m_addr_processed);
+            obj.pushKV("addr_rate_limited", statestats.m_addr_rate_limited);
         }
         UniValue permissions(UniValue::VARR);
         for (const auto& permission : NetPermissions::ToStrings(stats.m_permissionFlags)) {