net: advertise NODE_P2P_V2 if CLI arg -v2transport is on

Co-authored-by: Dhruv Mehta <856960+dhruv@users.noreply.github.com>

src/init.cpp

@@ -498,6 +498,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-i2psam=<ip:port>", "I2P SAM proxy to reach I2P peers and accept I2P connections (default: none)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-i2pacceptincoming", strprintf("Whether to accept inbound I2P connections (default: %i). Ignored if -i2psam is not set. Listening for inbound I2P connections is done through the SAM proxy, not by binding to a local address and port.", DEFAULT_I2P_ACCEPT_INCOMING), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-onlynet=<net>", "Make automatic outbound connections only to network <net> (" + Join(GetNetworkNames(), ", ") + "). Inbound and manual connections are not affected by this option. It can be specified multiple times to allow multiple networks.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
+    argsman.AddArg("-v2transport", strprintf("Support v2 transport (default: %u)", DEFAULT_V2_TRANSPORT), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-peerbloomfilters", strprintf("Support filtering of blocks and transaction with bloom filters (default: %u)", DEFAULT_PEERBLOOMFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-peerblockfilters", strprintf("Serve compact block filters to peers per BIP 157 (default: %u)", DEFAULT_PEERBLOCKFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-txreconciliation", strprintf("Enable transaction reconciliations per BIP 330 (default: %d)", DEFAULT_TXRECONCILIATION_ENABLE), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CONNECTION);
@@ -893,6 +894,11 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         }
     }
 
+    // Signal NODE_P2P_V2 if BIP324 v2 transport is enabled.
+    if (args.GetBoolArg("-v2transport", DEFAULT_V2_TRANSPORT)) {
+        nLocalServices = ServiceFlags(nLocalServices | NODE_P2P_V2);
+    }
+
     // Signal NODE_COMPACT_FILTERS if peerblockfilters and basic filters index are both enabled.
     if (args.GetBoolArg("-peerblockfilters", DEFAULT_PEERBLOCKFILTERS)) {
         if (g_enabled_filter_types.count(BlockFilterType::BASIC) != 1) {

src/net.h

@@ -94,6 +94,8 @@ static constexpr bool DEFAULT_FIXEDSEEDS{true};
 static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000;
 static const size_t DEFAULT_MAXSENDBUFFER    = 1 * 1000;
 
+static constexpr bool DEFAULT_V2_TRANSPORT{false};
+
 typedef int64_t NodeId;
 
 struct AddedNodeInfo

src/protocol.cpp

@@ -199,6 +199,7 @@ static std::string serviceFlagToStr(size_t bit)
     case NODE_WITNESS:         return "WITNESS";
     case NODE_COMPACT_FILTERS: return "COMPACT_FILTERS";
     case NODE_NETWORK_LIMITED: return "NETWORK_LIMITED";
+    case NODE_P2P_V2:          return "P2P_V2";
     // Not using default, so we get warned when a case is missing
     }
 

src/protocol.h

@@ -291,6 +291,9 @@ enum ServiceFlags : uint64_t {
     // See BIP159 for details on how this is implemented.
     NODE_NETWORK_LIMITED = (1 << 10),
 
+    // NODE_P2P_V2 means the node supports BIP324 transport
+    NODE_P2P_V2 = (1 << 11),
+
     // Bits 24-31 are reserved for temporary experiments. Just pick a bit that
     // isn't getting used, or one not being used much, and notify the
     // bitcoin-development mailing list. Remember that service bits are just

src/test/util/net.h

@@ -65,6 +65,7 @@ constexpr ServiceFlags ALL_SERVICE_FLAGS[]{
     NODE_WITNESS,
     NODE_COMPACT_FILTERS,
     NODE_NETWORK_LIMITED,
+    NODE_P2P_V2,
 };
 
 constexpr NetPermissionFlags ALL_NET_PERMISSION_FLAGS[]{

test/functional/test_framework/messages.py

@@ -52,6 +52,7 @@
 NODE_WITNESS = (1 << 3)
 NODE_COMPACT_FILTERS = (1 << 6)
 NODE_NETWORK_LIMITED = (1 << 10)
+NODE_P2P_V2 = (1 << 11)
 
 MSG_TX = 1
 MSG_BLOCK = 2