[World] Check if port in use to avoid double booting mistakes (#4740)

* Stuff

* Potentially fix aura crash

* Reload crash fix

* Revert "Reload crash fix"

This reverts commit 96e1e76306059fc2a624e0152eca4beaee49a0f8.

* Fix

* Update entity.cpp

* Update dbcore.cpp

* [World] Check if port in use to avoid double booting mistakes

* Revert "Stuff"

This reverts commit 2162c00eddfd13c7ff9fbe53cada1ea36373880c.

* Revert "Potentially fix aura crash"

This reverts commit 7c242723f40a0d013371c36e205a9917849ee862.

* Revert "Fix"

This reverts commit 8419e284d48bac823c861c480719eb3d3b8290a9.

* Revert "Update entity.cpp"

This reverts commit 8a1f4545a4e1c96a848866fb5b6185c66db09097.

* Revert "Update dbcore.cpp"

This reverts commit f0278d95910ccf9e1667eb0e1a0f2608aa7b6058.

common/ip_util.cpp

@@ -259,3 +259,76 @@ bool IpUtil::IsIPAddress(const std::string &ip_address)
 }
 
 
+#include <iostream>
+#ifdef _WIN32
+#include <winsock2.h>
+    #pragma comment(lib, "ws2_32.lib") // Link against Winsock library
+#else
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <unistd.h>
+#endif
+
+#include <iostream>
+#include <string>
+#ifdef _WIN32
+#include <winsock2.h>
+    #include <ws2tcpip.h>  // For inet_pton
+    #pragma comment(lib, "ws2_32.lib") // Link against Winsock library
+#else
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>  // For inet_pton
+#include <unistd.h>
+#endif
+
+bool IpUtil::IsPortInUse(const std::string& ip, int port) {
+	bool in_use = false;
+
+#ifdef _WIN32
+	WSADATA wsaData;
+    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
+        std::cerr << "WSAStartup failed\n";
+        return true; // Assume in use on failure
+    }
+#endif
+
+	int sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock < 0) {
+#ifdef _WIN32
+		WSACleanup();
+#endif
+		return true; // Assume in use on failure
+	}
+
+	sockaddr_in addr{};
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(port);
+
+	// Convert IP address from string to binary format
+	if (inet_pton(AF_INET, ip.c_str(), &addr.sin_addr) <= 0) {
+		std::cerr << "Invalid IP address format: " << ip << std::endl;
+#ifdef _WIN32
+		closesocket(sock);
+        WSACleanup();
+#else
+		close(sock);
+#endif
+		return true; // Assume in use on failure
+	}
+
+	if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
+		in_use = true; // Bind failed, port is in use
+	}
+
+#ifdef _WIN32
+	closesocket(sock);
+    WSACleanup();
+#else
+	close(sock);
+#endif
+
+	return in_use;
+}

common/ip_util.h

@@ -37,6 +37,7 @@ public:
 		int port
 	);
 	static bool IsIPAddress(const std::string &ip_address);
+	static bool IsPortInUse(const std::string& ip, int port);
 
 };
 

world/main.cpp

@@ -89,6 +89,7 @@
 #include "../common/events/player_event_logs.h"
 #include "../common/skill_caps.h"
 #include "../common/repositories/character_parcels_repository.h"
+#include "../common/ip_util.h"
 
 SkillCaps           skill_caps;
 ZoneStore           zone_store;
@@ -188,6 +189,16 @@ int main(int argc, char **argv)
 	launcher_list.LoadList();
 	zoneserver_list.Init();
 
+	if (IpUtil::IsPortInUse(Config->WorldIP, Config->WorldTCPPort)) {
+		LogError("World port [{}] already in use", Config->WorldTCPPort);
+		return 1;
+	}
+
+	if (IpUtil::IsPortInUse(Config->TelnetIP, Config->TelnetTCPPort)) {
+		LogError("Telnet port [{}] already in use", Config->TelnetTCPPort);
+		return 1;
+	}
+
 	std::unique_ptr<EQ::Net::ConsoleServer> console;
 	if (Config->TelnetEnabled) {
 		LogInfo("Console (TCP) listener started on [{}:{}]", Config->TelnetIP, Config->TelnetTCPPort);