scan for open tcp ports for js api

globals.cpp

@@ -21,5 +21,5 @@ const std::filesystem::path REPO_PATH = APP_DIR / "repositories.txt";
 
 // Holds the current package installation state
 int SPPLICE_INSTALL_STATE = 0; // 0 - idle; 1 - installing; 2 - installed
-// TCP communication port between Portal 2 and Spplice
-const int SPPLICE_NETCON_PORT = 22333;
+// TCP communication port between Portal 2 and Spplice (set during runtime)
+int SPPLICE_NETCON_PORT = -1;

globals.h

@@ -11,6 +11,6 @@ extern bool CACHE_ENABLE;
 extern const std::filesystem::path APP_DIR;
 extern const std::filesystem::path REPO_PATH;
 extern int SPPLICE_INSTALL_STATE;
-extern const int SPPLICE_NETCON_PORT;
+extern int SPPLICE_NETCON_PORT;
 
 #endif

tools/install.cpp

@@ -11,6 +11,7 @@
 
 #include "../globals.h" // Project globals
 #include "curl.h" // ToolsCURL
+#include "netcon.h" // ToolsNetCon
 #include "qt.h" // ToolsQT
 #include "js.h" // ToolsJS
 
@@ -201,8 +202,12 @@ bool startPortal2 (const std::vector<std::string> extraArgs) {
     args.push_back("-applaunch");
     args.push_back("620");
     args.push_back("-tempcontent");
-    args.push_back("-netconport");
-    args.push_back(std::to_string(SPPLICE_NETCON_PORT).c_str());
+
+    // If a valid port has been established, enable TCP console server
+    if (SPPLICE_NETCON_PORT != -1) {
+      args.push_back("-netconport");
+      args.push_back(std::to_string(SPPLICE_NETCON_PORT).c_str());
+    }
 
     // Append any additional package-specific arguments
     for (const std::string &arg : extraArgs) {
@@ -216,7 +221,9 @@ bool startPortal2 (const std::vector<std::string> extraArgs) {
     std::cerr << "Failed to call Steam binary from fork." << std::endl;
 
     // If the above failed, revert to using the Steam browser protocol
-    std::string command = "xdg-open steam://run/620//-tempcontent -netconport " + std::to_string(SPPLICE_NETCON_PORT);
+    std::string command = "xdg-open steam://run/620//-tempcontent";
+    if (SPPLICE_NETCON_PORT != -1) command += " -netconport " + std::to_string(SPPLICE_NETCON_PORT);
+
     for (const std::string &arg : extraArgs) {
       command += " " + arg;
     }
@@ -251,7 +258,10 @@ bool startPortal2 (const std::vector<std::string> extraArgs) {
   si.dwFlags = STARTF_USESHOWWINDOW;
   si.wShowWindow = SW_HIDE;  // Hide the window for the detached process
 
-  std::wstring args = L"-applaunch 620 -tempcontent -netconport " + std::to_wstring(SPPLICE_NETCON_PORT);
+  std::wstring args = L"-applaunch 620 -tempcontent";
+  if (SPPLICE_NETCON_PORT != -1) {
+    args += L" -netconport " + std::to_wstring(SPPLICE_NETCON_PORT);
+  }
 
   // Append any additional package-specific arguments
   for (const std::string &arg : extraArgs) {
@@ -499,6 +509,26 @@ std::pair<bool, std::wstring> ToolsInstall::installPackageFile (const std::files
   std::filesystem::create_directories(tmpPackageDirectory / "maps");
   std::filesystem::create_directories(tmpPackageDirectory / "maps" / "soundcache");
 
+  // Find the JS API entry point
+  const std::filesystem::path jsEntryPoint = tmpPackageDirectory / "main.js";
+  bool jsEntryPointExists = std::filesystem::exists(jsEntryPoint);
+
+  // Disable the TCP console server by default
+  SPPLICE_NETCON_PORT = -1;
+
+  // If the JS API is in use, enable the TCP console server
+  if (jsEntryPointExists) {
+    // Find an open TCP port
+    SPPLICE_NETCON_PORT = ToolsNetCon::findOpenPort(1024, 49151);
+    if (SPPLICE_NETCON_PORT == -1) {
+  #ifndef TARGET_WINDOWS
+      return std::pair<bool, std::string> (false, "Failed to find an open port for the JS API.");
+  #else
+      return std::pair<bool, std::wstring> (false, L"Failed to find an open port for the JS API.");
+  #endif
+    }
+  }
+
   // Start Portal 2
   if (!startPortal2(args)) {
     std::filesystem::remove_all(tmpPackageDirectory);
@@ -565,13 +595,11 @@ std::pair<bool, std::wstring> ToolsInstall::installPackageFile (const std::files
     std::filesystem::copy_file(soundcacheSourcePath, soundcacheDestPath);
   }
 
-  // Run the JavaScript entrypoint (if one exists) on a detached thread
-  const std::filesystem::path jsEntryPoint = tmpPackageDirectory / "main.js";
-  if (std::filesystem::exists(jsEntryPoint)) {
-    std::thread jsThread([jsEntryPoint]() {
+  // Run the JS API entrypoint (if one exists) on a detached thread
+  if (jsEntryPointExists) {
+    std::thread ([jsEntryPoint]() {
       ToolsJS::runFile(jsEntryPoint);
-    });
-    jsThread.detach();
+    }).detach();
   }
 
   // Report install success to the UI

tools/netcon.cpp

@@ -15,9 +15,10 @@
 // Definitions for this source file
 #include "netcon.h"
 
-// Counts the amount of open netcon sockets for setup and cleanup
-// I have absolutely no idea why you'd ever need more than one, but oh well...
+#ifdef TARGET_WINDOWS
+// Counts the amount of open netcon sockets for Winsock setup and cleanup
 int openSockets = 0;
+#endif
 
 // Closes the given socket
 void ToolsNetCon::disconnect (int sockfd)
@@ -33,6 +34,62 @@ void ToolsNetCon::disconnect (int sockfd)
 }
 #endif
 
+// Finds an open TCP port in the given range (inclusive)
+int ToolsNetCon::findOpenPort (const int start, const int end) {
+
+#ifdef TARGET_WINDOWS
+  // If no sockets are open, set up Winsock
+  if (++openSockets == 1) {
+    WSADATA wsaData;
+    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
+      std::cerr << "WSAStartup failed." << std::endl;
+      return -1;
+    }
+  }
+#endif
+
+  for (int port = start; port <= end; port ++) {
+
+    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
+    if (sockfd < 0) {
+      std::cerr << "Socket creation failed on port " << port << " when scanning for open ports." << std::endl;
+      break;
+    }
+
+    struct sockaddr_in addr;
+    memset(&addr, 0, sizeof(addr));
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = INADDR_ANY;
+    addr.sin_port = htons(port);
+
+    int result = bind(sockfd, (struct sockaddr*)&addr, sizeof(addr));
+    if (result == 0) {
+      // Successfully bound to the port, close the socket and return the port
+      ToolsNetCon::disconnect(sockfd);
+      return port;
+    }
+
+#ifdef TARGET_WINDOWS
+    // Increment openSockets to prevent Winsock from being cleaned up
+    openSockets ++;
+#endif
+
+    // Port is in use, try the next one
+    ToolsNetCon::disconnect(sockfd);
+
+  }
+
+#ifdef TARGET_WINDOWS
+  // Reset openSockets and clean up Winsock manually
+  openSockets --;
+  WSACleanup();
+#endif
+
+  // No open port found in the range
+  return -1;
+
+}
+
 // Attempts to connect to the game's TCP console on SPPLICE_NETCON_PORT
 int ToolsNetCon::attemptConnection () {
 
@@ -70,7 +127,7 @@ int ToolsNetCon::attemptConnection () {
 
 }
 
-// Sends a command to the TCP consoleserver on the given socket
+// Sends a command to the TCP console server on the given socket
 bool ToolsNetCon::sendCommand (int sockfd, std::string command) {
 
   // Commands are only processed upon line termination

tools/netcon.h

@@ -7,6 +7,7 @@ class ToolsNetCon {
   public:
     static int attemptConnection ();
     static void disconnect (int sockfd);
+    static int findOpenPort (const int start, const int end);
     static bool sendCommand (int sockfd, std::string command);
     static std::string readConsole (int sockfd, size_t size);
 };