Core/Socket: Unix domain socket (AF_UNIX) support for Windows (#328)

Refactor UnixSocket.cpp with error handling

Updated UnixSocket.cpp to include error handling and platform-specific path definitions.

UnixSocketClient: Update socket path for cross-platform compatibility

UnixSocketServer: Update socket path for Windows and Unix platforms

Core: UnixSocket example code, socket path fixed

autotest/UnixSocket: path correction and unlink.

autotest/UnixSocket/UnixSocket.cpp

@@ -2,50 +2,63 @@
 
 using namespace Upp;
 
+String GetSocketPath()
+{
+	String temp;
+#ifdef PLATFORM_WIN32
+	temp = GetEnv("TEMP");
+#else
+	temp = GetTempPath();
+#endif
+	return AppendFileName(temp, "upp-unixsocket.socket");
+}
+
 CONSOLE_APP_MAIN
 {
-#ifdef PLATFORM_POSIX
-
 	StdLogSetup(LOG_COUT|LOG_FILE);
 
-	String path = Format("/tmp/upp-unixsocket-test-%d", getpid());
+	String path = GetSocketPath();
-	
-	Socket server, client;
-	
-	// Test server listen
-	if(!server.ListenFileSystem(path)) {
-		LOG("Server listen failed: " << server.GetErrorDesc());
-		Exit(1);
-	}
-	
-	// Test client connect
-	if(!client.ConnectFileSystem(path)) {
-		LOG("Client connect failed: " << client.GetErrorDesc());
-		Exit(1);
-	}
-	
-	// Test data exchange
-	String test_data = "Hello, world!";
-	client.Put(test_data + "\n");
-	
-	Socket accepted;
-	if(!accepted.Accept(server)) {
-		LOG("Accept failed: " << accepted.GetErrorDesc());
-		Exit(1);
-	}
-	
-	String received = accepted.GetLine();
-	DUMP(received);
-	
-	ASSERT(received == test_data);
-	
-	// Test peer PID (on supported platforms)
-	int pid = accepted.GetPeerPid();
-	DUMP(pid);
-	if(pid != -1)
-		ASSERT(pid == getpid()); // Should be our own process in this test
 
-	LOG("=========== OK");
+	try {
+		Socket server, client;
 
-#endif
+		DeleteFile(path); // "unlink" existing FS socket if possible
-}
+		
+		// Test server listen
+		if(!server.ListenFileSystem(path, 5, false)) {
+			throw Exc("Server listen failed: " << server.GetErrorDesc());
+		}
+		
+		// Test client connect
+		if(!client.ConnectFileSystem(path)) {
+			throw Exc("Client connect failed: " << client.GetErrorDesc());
+		}
+		
+		// Test data exchange
+		String test_data = "Hello, world!";
+		client.Put(test_data + "\n");
+		
+		Socket accepted;
+		if(!accepted.Accept(server)) {
+			throw Exc("Accept failed: " << accepted.GetErrorDesc());
+		}
+		
+		String received = accepted.GetLine();
+		DUMP(received);
+		
+		ASSERT(received == test_data);
+		
+		// Test peer PID (on supported platforms)
+		int pid = accepted.GetPeerPid();
+		DUMP(pid);
+		if(pid != -1)
+			ASSERT(pid == getpid()); // Should be our own process in this test
+
+		LOG("=========== OK");
+	}
+	catch(const Exc& e)
+	{
+		LOG(e);
+		SetExitCode(1);
+	}
+}

reference/UnixSocketClient/UnixSocketClient.cpp

@@ -3,26 +3,31 @@
 using namespace Upp;
 
 // Start reference/UnixSocketServer before starting this program
+String GetSocketPath()
+{
+	String temp;
+#ifdef PLATFORM_WIN32
+	temp = GetEnv("TEMP");
+#else
+	temp = GetTempPath();
+#endif
+	return AppendFileName(temp, "upp-unixsocket.socket");
+}
+
+String Request(const String r)
+{
+	Socket s;
+	if(!s.ConnectFileSystem(GetSocketPath())) {
+		Cout() << "Unable to connect to server!\n";
+		SetExitCode(1);
+		return String();
+	}
+	s.Put(r + '\n');
+	return s.GetLine();
+}
 
 CONSOLE_APP_MAIN
 {
-#ifdef PLATFORM_POSIX
-	auto Request = [](const String& r)
-	{
-		Socket s;
-		if(!s.ConnectFileSystem("/tmp/upp-unixsocket.sock")) {
-			Cout() << "Unable to connect to server!\n";
-			SetExitCode(1);
-			return String();
-		}
-		s.Put(r + '\n');
-		return s.GetLine();
-	};
-
 	Cout() << Request("time") << '\n';
 	Cout() << Request("33") << '\n';
-#else
-	Cout() << "This example requires a POSIX compliant operating system...\r\n"
-	SetExitCode(1);
-#endif
 }

reference/UnixSocketServer/UnixSocketServer.cpp

@@ -2,13 +2,23 @@
 
 using namespace Upp;
 
+String GetSocketPath()
+{
+	String temp;
+#ifdef PLATFORM_WIN32
+	temp = GetEnv("TEMP");
+#else
+	temp = GetTempPath();
+#endif
+	return AppendFileName(temp, "upp-unixsocket.socket");
+}
+
 CONSOLE_APP_MAIN
 {
-#ifdef PLATFORM_POSIX
-	const String& path = "/tmp/upp-unixsocket.sock";
-	
 	Socket server;
-	if(!server.ListenFileSystem(path, 5)) {
+	String path = GetSocketPath();
+	DeleteFile(path); // "unlink" existing file system socket
+	if(!server.ListenFileSystem(path, 5, false)) { // Reuse option is not available on Windows
 		Cout() << "Unable to initialize server socket!\n";
 		SetExitCode(1);
 		return;
@@ -26,8 +36,4 @@ CONSOLE_APP_MAIN
 			s.Put("\n");
 		}
 	}
-#else
-	Cout() << "This example requires a POSIX compliant operating system...\r\n"
-	SetExitCode(1);
-#endif
 }

uppsrc/Core/Inet.h

@@ -171,11 +171,10 @@ class Socket : NoCopy {
 
 	static int              GetErrorCode();
 	static void             Init();
-	
+
-#ifdef PLATFORM_POSIX // Unix domain socket support
+    // Unix domain socket support
     bool                    NixConnect(const String& path, bool abstract);
     bool                    NixListen(const String& path, int n, bool reuse, bool abstract);
-#endif
 
 	Socket(const Socket&);
 
@@ -217,13 +216,11 @@ public:
 	void            Close();
 	void            Shutdown();
 
-#ifdef PLATFORM_POSIX
 	int             GetPeerPid() const;
 	bool            ConnectFileSystem(const String& path);
 	bool            ConnectAbstract(const String& path);
 	bool            ListenFileSystem(const String& path, int listen_count = 5, bool reuse = true);
 	bool            ListenAbstract(const String& path, int listen_count = 5, bool reuse = true);
-#endif
 
 	void            NoDelay();
 	void            Linger(int msecs);

uppsrc/Core/Socket.cpp

@@ -3,7 +3,11 @@
 #ifdef PLATFORM_WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
+#ifdef AF_UNIX // Unix domain (AF_UNIX) socket support, Windows 10+
+#include <afunix.h>
 #endif
+#endif
+
 
 #ifdef PLATFORM_POSIX
 #include <arpa/inet.h>
@@ -984,40 +988,43 @@ void Socket::Clear()
 	Reset();
 }
 
-#ifdef PLATFORM_POSIX
+static socklen_t sSetUnixSockType(Socket& s, const String& path, sockaddr_un& addr,  bool abstract)
-
-static bool sSetUnixSockType(Socket& s, const String& path, sockaddr_un& addr, bool abstract)
 {
-	memset(&addr, 0, sizeof(addr));
+#ifdef AF_UNIX
-	addr.sun_family = AF_UNIX;
+    memset(&addr, 0, sizeof(addr));
-
+    addr.sun_family = AF_UNIX;
 #ifndef PLATFORM_LINUX
-	if(abstract) {
+    if(abstract) {
-		s.SetSockError("SetUnixSockType",
+        s.SetSockError("SetUnixSockType",
-						-1, "Abstract socket is not supported on this platform");
+                       -1, "Abstract socket is not supported on this platform");
-		return false;
+        return 0;
-	}
+    }
 #endif
+    const int len = path.GetLength();
 
-	if(abstract) {
+    if(abstract) {
-		addr.sun_path[0] = '\0';
+        if(len <= 0 || len > int(sizeof(addr.sun_path) - 1)) {
-		if(path.GetLength() > 0) {
+            s.SetSockError("SetUnixSockType", -1, "Abstract socket name too long");
-			ASSERT(path.GetLength() < sizeof(addr.sun_path) - 1);
+            return 0;
-			strncpy(addr.sun_path + 1, ~path, sizeof(addr.sun_path) - 2);
+        }
-			return true;
+        addr.sun_path[0] = '\0';
-		}
+        memcpy(addr.sun_path + 1, ~path, len);
-	}
+        return offsetof(sockaddr_un, sun_path) + 1 + len;
-	else {
+    }
-		if(path.GetLength() > 0) {
+    else {
-			ASSERT(path.GetLength() < sizeof(addr.sun_path));
+        if(len <= 0 || len >= int(sizeof(addr.sun_path))) {
-			strncpy(addr.sun_path, ~path, sizeof(addr.sun_path) - 1);
+            s.SetSockError("SetUnixSockType", -1, "Unix socket path too long");
-			addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
+            return 0;
-			return true;
+        }
-		}
+        memcpy(addr.sun_path, ~path, len);
-	}
+        addr.sun_path[len] = '\0';
-	s.SetSockError("SetUnixSockType",
+        return offsetof(sockaddr_un, sun_path) + len + 1;
-						-1, "Failed to set unix domain socket type");
+    }
-	return false;
+#else
+       s.SetSockError("SetUnixSockType",
+                      -1, "Unix domain socket is not supported on this platform");
+#endif
+    return 0;
 }
 
 int Socket::GetPeerPid() const
@@ -1048,21 +1055,27 @@ bool Socket::NixConnect(const String& path, bool abstract)
 	Init();
 	Reset();
 
+#ifdef AF_UNIX
 	if(!Open(AF_UNIX, SOCK_STREAM, 0))
 		return false;
 
 	struct sockaddr_un addr;
-	if(!sSetUnixSockType(*this, path, addr, abstract))
+	socklen_t addrlen = 0;
+	if((addrlen = sSetUnixSockType(*this, path, addr, abstract)) == 0)
 		return false;
 
-	if(connect(socket, (sockaddr *) &addr, sizeof(addr)) == 0 ||
+	if(connect(socket, (sockaddr *) &addr, addrlen) == 0 ||
-		GetErrorCode() == EINPROGRESS || GetErrorCode() == EWOULDBLOCK) {
+		findarg(GetErrorCode(), SOCKERR(EINPROGRESS), SOCKERR(EWOULDBLOCK)) >= 0) {
 			mode = Socket::CONNECT;
 			return true;
 	}
 
 	SetSockError("connect", -1, strerror(GetErrorCode()));
 	Close();
+#else
+    SetSockError("NixConnect",
+                 -1, "Unix domain socket is not supported on this platform");
+#endif
 	return false;
 }
 
@@ -1082,11 +1095,13 @@ bool Socket::NixListen(const String& path, int n, bool reuse, bool abstract)
 	Init();
 	Reset();
 
+#ifdef AF_UNIX
 	if(!Open(AF_UNIX, SOCK_STREAM, 0))
 		return false;
 
 	struct sockaddr_un addr;
-	if(!sSetUnixSockType(*this, path, addr, abstract))
+	socklen_t addrlen = 0;
+	if((addrlen = sSetUnixSockType(*this, path, addr, abstract)) == 0)
 		return false;
 	
 	if(reuse) {
@@ -1094,7 +1109,7 @@ bool Socket::NixListen(const String& path, int n, bool reuse, bool abstract)
 		setsockopt(socket, SOL_SOCKET, SO_REUSEADDR, (const char *) &optval, sizeof(optval));
 	}
 
-	if(bind(socket, (const sockaddr *) &addr, sizeof(addr))) {
+	if(bind(socket, (const sockaddr *) &addr, addrlen)) {
 		SetSockError(Format("bind(path=%s)", path));
 		return false;
 	}
@@ -1105,6 +1120,12 @@ bool Socket::NixListen(const String& path, int n, bool reuse, bool abstract)
 	}
 
 	return true;
+	
+#else
+   SetSockError("NixListen",
+                -1, "Unix domain socket is not supported on this platform");
+    return false;
+#endif
 }
 
 bool Socket::ListenFileSystem(const String& path, int listen_count, bool reuse)
@@ -1117,9 +1138,6 @@ bool Socket::ListenAbstract(const String& path, int listen_count, bool reuse)
 	return NixListen(path, listen_count, reuse, true);
 }
 
-#endif
-
-
 int SocketWaitEvent::Wait(int timeout)
 {
 	FD_ZERO(read);

uppsrc/Core/src.tpp/Socket_en-us.tpp

@@ -34,11 +34,10 @@ tring]_[* GetHostName]()&]
 [s4; &]
 [s5;:Socket`:`:GetPeerPid`(`)const: [@(0.0.255) int] [* GetPeerPid]() 
 [@(0.0.255) const]&]
-[s6; POSIX only&]
 [s2;%% Returns the process ID (pid) of the peer on success, `-1 on 
 failure. On non`-blocking mode, make sure that socket is actually 
 connected or accepted. This is only available on unix domain 
-(local) sockets.&]
+(local) sockets and will fail with return code `-1 on Windows.&]
 [s3; &]
 [s4; &]
 [s5;:Socket`:`:GetDone`(`)const: [@(0.0.255) int]_[* GetDone]()_[@(0.0.255) const]&]
@@ -120,8 +119,7 @@ pAddrInfo][@(0.0.255) `&]_[*@3 info])&]
 [s3;%% &]
 [s4; &]
 [s5;:Upp`:`:Socket`:`:ConnectFileSystem`(const String`&`): [@(0.0.255) bool] 
-[* ConnectFileSystem]([@(0.0.255) const] String[@(0.0.255) `&] [*@3 path])&]
+[* ConnectFileSystem]([@(0.0.255) const] String[@(0.0.255) `&] [@3 path])&]
-[s6;%% POSIX only&]
 [s2;%% Connects socket to a Unix domain server bound at the given 
 file system [%-*@3 path]. The path must exist on the file system. 
 Returns true if connection is successful (blocking mode) or connection 
@@ -138,8 +136,8 @@ and does not correspond to a file system path. Returns true if
 connection is successful (blocking mode) or connection is in 
 progress (non blocking mode). Abstract sockets exist only in 
 kernel memory and disappear when processes exit. On non`-Linux 
-POSIX systems, this function will fail and set the socket into 
+systems, this function will fail and set the socket into error 
-error state. &]
+state. &]
 [s3; &]
 [s4; &]
 [s5;:Socket`:`:WaitConnect`(`): [@(0.0.255) bool]_[* WaitConnect]()&]
@@ -169,15 +167,23 @@ for ipv6`=`=true.&]
 [s3;%% &]
 [s4; &]
 [s5;:Upp`:`:Socket`:`:ListenFileSystem`(const String`&`,int`,bool`): [@(0.0.255) bool] 
-[* ListenFileSystem]([@(0.0.255) const ]String[@(0.0.255) `&] [*@3 path], 
+[* ListenFileSystem(][*@(0.0.255) const ][* String][*@(0.0.255) `&][*  
-[@(0.0.255) int] [*@3 listen`_count] [@(0.0.255) `=] [@3 5], [@(0.0.255) bool] 
+][*@3 path][* , ][*@(0.0.255) int][*  ][*@3 listen`_count][*  ][*@(0.0.255) `=][*  
-[*@3 reuse] [@(0.0.255) `=] [@(0.0.255) true])&]
+][*@3 5][* , ][*@(0.0.255) bool][*  ][*@3 reuse][*  ][*@(0.0.255) `=][*  ][*@(0.0.255) true][* )]&]
-[s6; POSIX only&]
 [s2;%% Creates a Unix domain server socket bound to the given file 
 system [%-*@3 path]. [%-*@3 listen`_count] specifies the maximum 
 number of pending connections in the queue. [%-*@3 reuse] indicates 
 whether the socket should allow reuse of the address if it already 
-exists. returns true if the listen is successful.&]
+exists. returns true if the listen is successful. &]
+[s2;%% &]
+[s2;%% Notes:&]
+[s2;i150;O0;%%  [%-*@3 reuse] option is not supported on Windows and 
+if specified the listen will fail and set the socket into error 
+state. &]
+[s2;i150;O0;%% Client code is responsible for the socket [%-*@3 path]’s 
+lifetime. For filesystem`-based Unix domain sockets, the pathname 
+must be unlinked explicitly after shutdown, as it is not removed 
+automatically when the socket is closed.&]
 [s3; &]
 [s4; &]
 [s5;:Upp`:`:Socket`:`:ListenAbstract`(const String`&`,int`,bool`): [@(0.0.255) bool] 
@@ -191,8 +197,8 @@ not correspond to a file system path). [%-*@3 listen`_count] specifies
 the maximum number of pending connections. [%-*@3 reuse] indicates 
 whether the abstract socket name can be reused. Abstract sockets 
 exist only in kernel memory and disappear when processes exit. 
-On non`-Linux POSIX systems, this method will fail and set the 
+On non`-Linux systems, this method will fail and set the socket 
-socket into error state.&]
+into error state.&]
 [s3; &]
 [s4;%% &]
 [s5;:Socket`:`:Accept`(Socket`&`): [@(0.0.255) bool]_[* Accept]([_^topic`:`/`/Core`/src`/TcpSocket`$en`-us`#TcpSocket`:`:class^ S