Added `--p2p-external-port` command line parameter

docs/COMMAND_LINE.MD

@@ -25,6 +25,7 @@
 --rpc-login          Specify username[:password] required for Monero RPC server
 --socks5             Specify IP:port of a SOCKS5 proxy to use for outgoing connections
 --no-dns             disable DNS queries, use only IP addresses to connect to peers (seed node DNS will be unavailable too)
+--p2p-external-port  port number that your router uses for mapping to your local p2p port. Use it if you are behind a NAT and still want to accept incoming connections
 ```
 
 ### Example command line

src/main.cpp

@@ -50,6 +50,7 @@ void p2pool_usage()
 		"--rpc-login          Specify username[:password] required for Monero RPC server\n"
 		"--socks5             Specify IP:port of a SOCKS5 proxy to use for outgoing connections\n"
 		"--no-dns             disable DNS queries, use only IP addresses to connect to peers (seed node DNS will be unavailable too)\n"
+		"--p2p-external-port  port number that your router uses for mapping to your local p2p port. Use it if you are behind a NAT and still want to accept incoming connections\n"
 		"--help               Show this help message\n\n"
 		"Example command line:\n\n"
 		"%s --host 127.0.0.1 --rpc-port 18081 --zmq-port 18083 --wallet YOUR_WALLET_ADDRESS --stratum 0.0.0.0:%d --p2p 0.0.0.0:%d\n\n",

src/p2p_server.cpp

@@ -933,6 +933,12 @@ void P2PServer::show_peers()
 	LOGINFO(0, "Total: " << n << " peers");
 }
 
+int P2PServer::listen_port() const
+{
+	const Params& params = m_pool->params();
+	return params.m_p2pExternalPort ? params.m_p2pExternalPort : m_listenPort;
+}
+
 int P2PServer::deserialize_block(const uint8_t* buf, uint32_t size)
 {
 	int result;

src/p2p_server.h

@@ -138,6 +138,8 @@ public:
 	void show_peers_async();
 	size_t peer_list_size() const { MutexLock lock(m_peerListLock); return m_peerList.size(); }
 
+	int listen_port() const override;
+
 	uint32_t max_outgoing_peers() const { return m_maxOutgoingPeers; }
 	uint32_t max_incoming_peers() const { return m_maxIncomingPeers; }
 

src/params.cpp

@@ -35,12 +35,12 @@ Params::Params(int argc, char* argv[])
 		}
 
 		if ((strcmp(argv[i], "--rpc-port") == 0) && (i + 1 < argc)) {
-			m_rpcPort = strtoul(argv[++i], nullptr, 10);
+			m_rpcPort = std::min(std::max(strtoul(argv[++i], nullptr, 10), 1UL), 65535UL);
 			ok = true;
 		}
 
 		if ((strcmp(argv[i], "--zmq-port") == 0) && (i + 1 < argc)) {
-			m_zmqPort = strtoul(argv[++i], nullptr, 10);
+			m_zmqPort = std::min(std::max(strtoul(argv[++i], nullptr, 10), 1UL), 65535UL);
 			ok = true;
 		}
 
@@ -146,6 +146,11 @@ Params::Params(int argc, char* argv[])
 			ok = true;
 		}
 
+		if ((strcmp(argv[i], "--p2p-external-port") == 0) && (i + 1 < argc)) {
+			m_p2pExternalPort = std::min(std::max(strtoul(argv[++i], nullptr, 10), 1UL), 65535UL);
+			ok = true;
+		}
+
 		if (!ok) {
 			fprintf(stderr, "Unknown command line parameter %s\n\n", argv[i]);
 			p2pool_usage();

src/params.h

@@ -52,6 +52,7 @@ struct Params
 	std::string m_rpcLogin;
 	std::string m_socks5Proxy;
 	bool m_dns = true;
+	uint32_t m_p2pExternalPort = 0;
 };
 
 } // namespace p2pool

src/tcp_server.h

@@ -42,7 +42,7 @@ public:
 
 	uv_loop_t* get_loop() { return &m_loop; }
 
-	int listen_port() const { return m_listenPort; }
+	virtual int listen_port() const { return m_listenPort; }
 
 	bool connect_to_peer(bool is_v6, const raw_ip& ip, int port);
 	virtual void on_connect_failed(bool /*is_v6*/, const raw_ip& /*ip*/, int /*port*/) {}