net: change CreateNodeFromAcceptedSocket() to take Sock

Change `CConnman::CreateNodeFromAcceptedSocket()` to take a `Sock`
argument instead of `SOCKET`.

This makes the method mockable and also a little bit shorter as some
`CloseSocket()` calls are removed (the socket will be closed
automatically by the `Sock` destructor on early return).

src/net.cpp

@@ -1120,10 +1120,10 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
     NetPermissionFlags permissionFlags = NetPermissionFlags::None;
     hListenSocket.AddSocketPermissionFlags(permissionFlags);
 
-    CreateNodeFromAcceptedSocket(sock->Release(), permissionFlags, addr_bind, addr);
+    CreateNodeFromAcceptedSocket(std::move(sock), permissionFlags, addr_bind, addr);
 }
 
-void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
+void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                                             NetPermissionFlags permissionFlags,
                                             const CAddress& addr_bind,
                                             const CAddress& addr)
@@ -1149,27 +1149,24 @@ void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
 
     if (!fNetworkActive) {
         LogPrint(BCLog::NET, "connection from %s dropped: not accepting new connections\n", addr.ToString());
-        CloseSocket(hSocket);
         return;
     }
 
-    if (!IsSelectableSocket(hSocket))
+    if (!IsSelectableSocket(sock->Get()))
     {
         LogPrintf("connection from %s dropped: non-selectable socket\n", addr.ToString());
-        CloseSocket(hSocket);
         return;
     }
 
     // According to the internet TCP_NODELAY is not carried into accepted sockets
     // on all platforms.  Set it again here just to be sure.
-    SetSocketNoDelay(hSocket);
+    SetSocketNoDelay(sock->Get());
 
     // Don't accept connections from banned peers.
     bool banned = m_banman && m_banman->IsBanned(addr);
     if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::NoBan) && banned)
     {
         LogPrint(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToString());
-        CloseSocket(hSocket);
         return;
     }
 
@@ -1178,7 +1175,6 @@ void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
     if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::NoBan) && nInbound + 1 >= nMaxInbound && discouraged)
     {
         LogPrint(BCLog::NET, "connection from %s dropped (discouraged)\n", addr.ToString());
-        CloseSocket(hSocket);
         return;
     }
 
@@ -1187,7 +1183,6 @@ void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
         if (!AttemptToEvictConnection()) {
             // No connection to evict, disconnect the new connection
             LogPrint(BCLog::NET, "failed to find an eviction candidate - connection dropped (full)\n");
-            CloseSocket(hSocket);
             return;
         }
     }
@@ -1201,7 +1196,7 @@ void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
     }
 
     const bool inbound_onion = std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();
-    CNode* pnode = new CNode(id, nodeServices, hSocket, addr, CalculateKeyedNetGroup(addr), nonce, addr_bind, "", ConnectionType::INBOUND, inbound_onion);
+    CNode* pnode = new CNode(id, nodeServices, sock->Release(), addr, CalculateKeyedNetGroup(addr), nonce, addr_bind, "", ConnectionType::INBOUND, inbound_onion);
     pnode->AddRef();
     pnode->m_permissionFlags = permissionFlags;
     pnode->m_prefer_evict = discouraged;
@@ -2329,7 +2324,7 @@ void CConnman::ThreadI2PAcceptIncoming()
             continue;
         }
 
-        CreateNodeFromAcceptedSocket(conn.sock->Release(), NetPermissionFlags::None,
+        CreateNodeFromAcceptedSocket(std::move(conn.sock), NetPermissionFlags::None,
                                      CAddress{conn.me, NODE_NONE}, CAddress{conn.peer, NODE_NONE});
     }
 }

src/net.h

@@ -974,12 +974,12 @@ private:
     /**
      * Create a `CNode` object from a socket that has just been accepted and add the node to
      * the `m_nodes` member.
-     * @param[in] hSocket Connected socket to communicate with the peer.
+     * @param[in] sock Connected socket to communicate with the peer.
      * @param[in] permissionFlags The peer's permissions.
      * @param[in] addr_bind The address and port at our side of the connection.
      * @param[in] addr The address and port at the peer's side of the connection.
      */
-    void CreateNodeFromAcceptedSocket(SOCKET hSocket,
+    void CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                                       NetPermissionFlags permissionFlags,
                                       const CAddress& addr_bind,
                                       const CAddress& addr);