fix: send/recv now uses MSG_NOSIGNAL, improved server logging, changed disconnect logic from heartbeat

Author: Jaskowicz1

include/rconpp/server.h

@@ -29,6 +29,8 @@ struct connected_client {
 
 	bool authenticated{false};
 
+	bool force_disconnect{false};
+
 	time_t last_heartbeat{0};
 };
 

include/rconpp/utilities.h

@@ -16,6 +16,10 @@ constexpr int MIN_PACKET_LENGTH = 14;
 constexpr int MAX_RETRIES_TO_RECEIVE_INFO = 500;
 constexpr int HEARTBEAT_TIME = 30;
 
+#ifndef MSG_NOSIGNAL
+#define MSG_NOSIGNAL 0
+#endif
+
 
 enum data_type {
 	/**
@@ -62,6 +66,12 @@ struct response {
 	bool server_responded{false};
 };
 
+enum error_type {
+	DISCONNECTED = 0,
+	BAD_FD = 1,
+	SHUTTING_DOWN = 2,
+};
+
 /**
  * @brief Form a valid RCON packet.
  *
@@ -92,9 +102,9 @@ RCONPP_EXPORT int bit32_to_int(const std::vector<char>& buffer);
 RCONPP_EXPORT int type_to_int(const std::vector<char>& buffer);
 
 /**
- * @brief Reports the recent socket error.
+ * @brief Converts the last error into error_type and reports it.
  */
-RCONPP_EXPORT void report_error();
+RCONPP_EXPORT error_type report_get_last_error();
 
 /**
  * @brief Reads the first 4 bytes of a packet to get the packet size (not to be mistaken with length).

src/rconpp/client.cpp

@@ -34,9 +34,9 @@ rconpp::response rconpp::rcon_client::send_data_sync(const std::string_view data
 
 	packet formed_packet = form_packet(data, id, type);
 
-	if (send(sock, formed_packet.data.data(), formed_packet.length, 0) < 0) {
+	if (send(sock, formed_packet.data.data(), formed_packet.length, MSG_NOSIGNAL) < 0) {
 		on_log("Sending failed!");
-		report_error();
+		report_get_last_error();
 		return { "", false };
 	}
 
@@ -69,7 +69,7 @@ bool rconpp::rcon_client::connect_to_server() {
 	if (sock == -1) {
 #endif
 		on_log("Failed to open socket.");
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
@@ -104,7 +104,7 @@ bool rconpp::rcon_client::connect_to_server() {
 	int status = connect(sock, (struct sockaddr*)&server, sizeof(server));
 
 	if (status == -1) {
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
@@ -178,7 +178,7 @@ rconpp::packet rconpp::rcon_client::read_packet() {
 	 * Receiving by the length of the packet will give us 4 extra bytes, so, we do by size here.
 	 * This is because read_packet_size() reads the first 4 bytes and discards them.
 	 */
-	recv(sock, buffer.data(), temp_packet.size, 0);
+	recv(sock, buffer.data(), temp_packet.size, MSG_NOSIGNAL);
 
 	temp_packet.data = buffer;
 

src/rconpp/server.cpp

@@ -55,7 +55,7 @@ bool rconpp::rcon_server::startup_server() {
 	if (sock == -1) {
 #endif
 		on_log("Failed to open socket.");
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
@@ -73,14 +73,14 @@ bool rconpp::rcon_server::startup_server() {
 	int status = bind(sock, reinterpret_cast<const sockaddr*>(&server), sizeof(server));
 
 	if (status == -1) {
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
 	status = listen(sock, SOMAXCONN);
 
 	if (status == -1) {
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
@@ -119,7 +119,7 @@ void rconpp::rcon_server::disconnect_client(const int client_socket, const bool
 }
 
 void rconpp::rcon_server::read_packet(connected_client& client) {
-	const int packet_size = read_packet_size(static_cast<int>(client.socket));
+	const int packet_size = read_packet_size(client.socket);
 
 	// Silently ignore packet size.
 	if (packet_size < MIN_PACKET_SIZE) {
@@ -129,9 +129,9 @@ void rconpp::rcon_server::read_packet(connected_client& client) {
 	std::vector<char> buffer{};
 	buffer.resize(packet_size);
 
-	if (recv(client.socket, buffer.data(), packet_size, 0) == -1) {
+	if (recv(client.socket, buffer.data(), packet_size, MSG_NOSIGNAL) == -1) {
 		on_log("Failed to get a packet from client.");
-		report_error();
+		report_get_last_error();
 		return;
 	}
 
@@ -149,8 +149,10 @@ void rconpp::rcon_server::read_packet(connected_client& client) {
 		if (packet_data == password) {
 			packet_to_send = form_packet("", id, SERVERDATA_AUTH_RESPONSE);
 			client.authenticated = true;
+			on_log("Client [" + std::string(inet_ntoa(client.sock_info.sin_addr)) + ":" + std::to_string(ntohs(client.sock_info.sin_port)) + "] has authenticated successfully!");
 		} else {
 			packet_to_send = form_packet("", -1, SERVERDATA_AUTH_RESPONSE);
+			on_log("Client [" + std::string(inet_ntoa(client.sock_info.sin_addr)) + ":" + std::to_string(ntohs(client.sock_info.sin_port)) + "] failed authentication!");
 		}
 	} else {
 		if (type != SERVERDATA_EXECCOMMAND) {
@@ -184,9 +186,9 @@ void rconpp::rcon_server::read_packet(connected_client& client) {
 
 	on_log("Sending packet (of size: " + std::to_string(packet_to_send.length) + ") to client [" + std::string(inet_ntoa(client.sock_info.sin_addr)) + ":" + std::to_string(ntohs(client.sock_info.sin_port)) + "]");
 
-	if (send(client.socket, packet_to_send.data.data(), packet_to_send.length, 0) < 0) {
+	if (send(client.socket, packet_to_send.data.data(), packet_to_send.length, MSG_NOSIGNAL) < 0) {
 		on_log("Sending failed!");
-		report_error();
+		report_get_last_error();
 		return;
 	}
 }
@@ -195,9 +197,9 @@ bool rconpp::rcon_server::send_heartbeat(connected_client& client) {
 	on_log("Sending heartbeat to client [" + std::string(inet_ntoa(client.sock_info.sin_addr)) + ":" + std::to_string(ntohs(client.sock_info.sin_port)) + "]");
 
 	packet packet_to_send = form_packet("", -1, SERVERDATA_RESPONSE_VALUE);
-	if (send(client.socket, packet_to_send.data.data(), packet_to_send.length, 0) < 0) {
+	if (send(client.socket, packet_to_send.data.data(), packet_to_send.length, MSG_NOSIGNAL) < 0) {
 		on_log("Failed to send a heartbeat to client [" + std::string(inet_ntoa(client.sock_info.sin_addr)) + ":" + std::to_string(ntohs(client.sock_info.sin_port)) + "]");
-		report_error();
+		report_get_last_error();
 		return false;
 	}
 
@@ -238,11 +240,11 @@ void rconpp::rcon_server::start(bool return_after) {
 
 			if (client_socket == -1) {
 				on_log("client with socket: \"" + std::to_string(client_socket) + "\" failed to connect.");
-				report_error();
+				report_get_last_error();
 				continue;
 			}
 
-			on_log("Client [" + std::string(inet_ntoa(client_info.sin_addr)) + ":" + std::to_string(ntohs(client_info.sin_port)) + "] has connected to the server.");
+			on_log("Client [" + std::string(inet_ntoa(client_info.sin_addr)) + ":" + std::to_string(ntohs(client_info.sin_port)) + "] has connected to the server, asking for authentication.");
 
 			connected_client client{};
 
@@ -260,12 +262,16 @@ void rconpp::rcon_server::start(bool return_after) {
 						if (client.last_heartbeat == 0 || current_time - client.last_heartbeat >= HEARTBEAT_TIME)
 						{
 							if (!send_heartbeat(client)) {
-								disconnect_client(client.socket);
-								return;
+								client.force_disconnect = true;
 							}
 						}
 					}
 
+					if (client.force_disconnect) {
+						disconnect_client(client.socket);
+						return;
+					}
+
 					// No need to let the server keep running this causing 100% usage on a thread, we can wait a bit between requests.
 					std::this_thread::sleep_for(std::chrono::milliseconds(100));
 				}

src/rconpp/utilities.cpp

@@ -38,12 +38,41 @@ int rconpp::type_to_int(const std::vector<char>& buffer) {
 	return static_cast<int>(buffer[4] | buffer[5] << 8 | buffer[6] << 16 | buffer[7] << 24);
 }
 
-void rconpp::report_error() {
+rconpp::error_type rconpp::report_get_last_error() {
+	error_type current_error;
+
+	int last_error{-1};
+
 #ifdef _WIN32
-	std::cout << "Error code: " << WSAGetLastError() << "\n";
+	last_error = WSAGetLastError();
 #else
-	std::cout << "Error code: " << errno << "\n";
+	last_error = errno;
+#endif;
+
+	std::cout << "Error code: " << last_error << "\n";
+
+#ifdef _WIN32
+	switch (last_error) {
+		default:
+		case WSAECONNRESET:
+			current_error = DISCONNECTED;
+			break;
+		case WSAEINTR:
+			current_error = SHUTTING_DOWN;
+			break;
+	}
+#else
+	switch (last_error) {
+		default:
+		case 32:
+		case 104:
+			current_error = DISCONNECTED;
+			break;
+		case:
+	}
 #endif
+
+	return current_error;
 }
 
 int rconpp::read_packet_size(int socket) {
@@ -54,8 +83,8 @@ int rconpp::read_packet_size(int socket) {
 	 * RCON gives the packet SIZE in the first four (4) bytes of each packet.
 	 * We simply just want to read that and then return it.
 	 */
-	if (recv(socket, buffer.data(), 4, 0) == -1) {
-		report_error();
+	if (recv(socket, buffer.data(), 4, MSG_NOSIGNAL) == -1) {
+		report_get_last_error();
 		return -1;
 	}