[rpc/net] Allow v2 p2p support in addconnection

This test-only RPC is required when a TestNode initiates
an outbound v2 p2p connection. Add a new arg `v2transport`
so that the node can attempt v2 connections.

src/net.cpp

@@ -1833,7 +1833,7 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
     RandAddEvent((uint32_t)id);
 }
 
-bool CConnman::AddConnection(const std::string& address, ConnectionType conn_type)
+bool CConnman::AddConnection(const std::string& address, ConnectionType conn_type, bool use_v2transport = false)
 {
     AssertLockNotHeld(m_unused_i2p_sessions_mutex);
     std::optional<int> max_connections;
@@ -1866,7 +1866,7 @@ bool CConnman::AddConnection(const std::string& address, ConnectionType conn_typ
     CSemaphoreGrant grant(*semOutbound, true);
     if (!grant) return false;
 
-    OpenNetworkConnection(CAddress(), false, std::move(grant), address.c_str(), conn_type, /*use_v2transport=*/false);
+    OpenNetworkConnection(CAddress(), false, std::move(grant), address.c_str(), conn_type, /*use_v2transport=*/use_v2transport);
     return true;
 }
 

src/net.h

@@ -1184,13 +1184,14 @@ public:
      * @param[in]   address     Address of node to try connecting to
      * @param[in]   conn_type   ConnectionType::OUTBOUND, ConnectionType::BLOCK_RELAY,
      *                          ConnectionType::ADDR_FETCH or ConnectionType::FEELER
+     * @param[in]   use_v2transport  Set to true if node attempts to connect using BIP 324 v2 transport protocol.
      * @return      bool        Returns false if there are no available
      *                          slots for this connection:
      *                          - conn_type not a supported ConnectionType
      *                          - Max total outbound connection capacity filled
      *                          - Max connection capacity for type is filled
      */
-    bool AddConnection(const std::string& address, ConnectionType conn_type) EXCLUSIVE_LOCKS_REQUIRED(!m_unused_i2p_sessions_mutex);
+    bool AddConnection(const std::string& address, ConnectionType conn_type, bool use_v2transport) EXCLUSIVE_LOCKS_REQUIRED(!m_unused_i2p_sessions_mutex);
 
     size_t GetNodeCount(ConnectionDirection) const;
     uint32_t GetMappedAS(const CNetAddr& addr) const;

src/rpc/client.cpp

@@ -302,6 +302,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "sendmsgtopeer", 0, "peer_id" },
     { "stop", 0, "wait" },
     { "addnode", 2, "v2transport" },
+    { "addconnection", 2, "v2transport" },
 };
 // clang-format on
 

src/rpc/net.cpp

@@ -370,6 +370,7 @@ static RPCHelpMan addconnection()
         {
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The IP address and port to attempt connecting to."},
             {"connection_type", RPCArg::Type::STR, RPCArg::Optional::NO, "Type of connection to open (\"outbound-full-relay\", \"block-relay-only\", \"addr-fetch\" or \"feeler\")."},
+            {"v2transport", RPCArg::Type::BOOL, RPCArg::Default{false}, "Attempt to connect using BIP324 v2 transport protocol"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -378,8 +379,8 @@ static RPCHelpMan addconnection()
                 { RPCResult::Type::STR, "connection_type", "Type of connection opened." },
             }},
         RPCExamples{
-            HelpExampleCli("addconnection", "\"192.168.0.6:8333\" \"outbound-full-relay\"")
+            HelpExampleCli("addconnection", "\"192.168.0.6:8333\" \"outbound-full-relay\" true")
-            + HelpExampleRpc("addconnection", "\"192.168.0.6:8333\" \"outbound-full-relay\"")
+            + HelpExampleRpc("addconnection", "\"192.168.0.6:8333\" \"outbound-full-relay\" true")
         },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
@@ -401,11 +402,16 @@ static RPCHelpMan addconnection()
     } else {
         throw JSONRPCError(RPC_INVALID_PARAMETER, self.ToString());
     }
+    bool use_v2transport = !request.params[2].isNull() && request.params[2].get_bool();
 
     NodeContext& node = EnsureAnyNodeContext(request.context);
     CConnman& connman = EnsureConnman(node);
 
-    const bool success = connman.AddConnection(address, conn_type);
+    if (use_v2transport && !(connman.GetLocalServices() & NODE_P2P_V2)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Error: Adding v2transport connections requires -v2transport init flag to be set.");
+    }
+
+    const bool success = connman.AddConnection(address, conn_type, use_v2transport);
     if (!success) {
         throw JSONRPCError(RPC_CLIENT_NODE_CAPACITY_REACHED, "Error: Already at capacity for specified connection type.");
     }