Merge #18877: Serve cfcheckpt requests

23083856a551ca13e8b142791c296ecb25cc4e7f [test] Add test for cfcheckpt (Jim Posen)
f9e00bb25ac4039056808affeb5ffa86a2c317fe [net processing] Message handling for getcfcheckpt. (Jim Posen)
9ccaaba11e94571fe984857494042ac292c17156 [init] Add -peerblockfilters option (Jim Posen)

Pull request description:

  Serve cfcheckpt messages if basic block filter index is enabled and `-peercfilters` is set.

  `NODE_COMPACT_FILTERS` is not signaled to peers, but functionality can be used for testing and serving pre-configured clients.

ACKs for top commit:
  jonatack:
    Code review re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f the only change since my review @ 967e2b1 is an update required for #16224 that was merged yesterday.
  fjahr:
    re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f
  jkczyz:
    re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f
  ariard:
    re-Code Review ACK 2308385
  clarkmoody:
    Tested ACK 23083856a
  MarcoFalke:
    re-ACK 23083856a5 🌳
  theStack:
    ACK https://github.com/bitcoin/bitcoin/commit/23083856a551ca13e8b142791c296ecb25cc4e7f

Tree-SHA512: 8c751bbd7d1c31a413096462ae025c3d2f3163c7016cbec472a5f5ec267f8dd19a2dfc4d749876d7409c1db546e6fdd16461c6863effcfa0d3e993edcfa92a08

1 files changed, 8 insertions, 0 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 221cab15f..010938a91 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -446,6 +446,7 @@ void SetupServerArgs(NodeContext& node)
     gArgs.AddArg("-onion=<ip:port>", "Use separate SOCKS5 proxy to reach peers via Tor hidden services, set -noonion to disable (default: -proxy)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     gArgs.AddArg("-onlynet=<net>", "Make outgoing connections only through network <net> (ipv4, ipv6 or onion). Incoming connections are not affected by this option. This option can be specified multiple times to allow multiple networks.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     gArgs.AddArg("-peerbloomfilters", strprintf("Support filtering of blocks and transaction with bloom filters (default: %u)", DEFAULT_PEERBLOOMFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
+    gArgs.AddArg("-peerblockfilters", strprintf("Serve compact block filters to peers per BIP 157 (default: %u)", DEFAULT_PEERBLOCKFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     gArgs.AddArg("-permitbaremultisig", strprintf("Relay non-P2SH multisig (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     gArgs.AddArg("-port=<port>", strprintf("Listen for connections on <port> (default: %u, testnet: %u, regtest: %u)", defaultChainParams->GetDefaultPort(), testnetChainParams->GetDefaultPort(), regtestChainParams->GetDefaultPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::CONNECTION);
     gArgs.AddArg("-proxy=<ip:port>", "Connect through SOCKS5 proxy, set -noproxy to disable (default: disabled)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
@@ -993,6 +994,13 @@ bool AppInitParameterInteraction()
         }
     }
 
+    // Basic filters are the only supported filters. The basic filters index must be enabled
+    // to serve compact filters
+    if (gArgs.GetBoolArg("-peerblockfilters", DEFAULT_PEERBLOCKFILTERS) &&
+        g_enabled_filter_types.count(BlockFilterType::BASIC) != 1) {
+        return InitError(_("Cannot set -peerblockfilters without -blockfilterindex."));
+    }
+
     // if using block pruning, then disallow txindex
     if (gArgs.GetArg("-prune", 0)) {
         if (gArgs.GetBoolArg("-txindex", DEFAULT_TXINDEX))