Merge #6295

6295: Implement FIFO on Windows using Named Pipes r=def- a=Robyt3

Reimplement the Linux FIFO file server and client controls on Windows by using Named Pipes.

The DDNet server/client acts as a named pipe server and receives messages.
Messages can be posted to the named pipe server by connecting to it as a client.
The named pipe client can for instance be controlled from the command line with PowerShell.

The PowerShell script `scripts/send_named_pipe.ps1` is added for this purpose.
For example the PowerShell command `./send_named_pipe.ps1 "testpipe" "echo a"` sends the command `echo a` to the pipe named `testpipe`.
Multiple commands can be sent at the same time by separating them with semicolons or newlines.

## Checklist

- [X] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test (especially base/) or added coverage to integration test
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: Robert Müller <robytemueller@gmail.com>

scripts/send_named_pipe.ps1

@@ -0,0 +1,33 @@
+# This PowerShell script connects to a Named Pipe server,
+# sends one message and then disconnects again.
+# The first argument is the name of the pipe.
+# The second argument is the message to send.
+if ($args.length -lt 2) {
+	Write-Output "Usage: ./send_named_pipe.ps1 <pipename> <message> [message] ... [message]"
+	return
+}
+
+$Wrapper = [pscustomobject]@{
+	Pipe = new-object System.IO.Pipes.NamedPipeClientStream(
+		".",
+		$args[0],
+		[System.IO.Pipes.PipeDirection]::InOut,
+		[System.IO.Pipes.PipeOptions]::None,
+		[System.Security.Principal.TokenImpersonationLevel]::Impersonation
+	)
+	Reader = $null
+	Writer = $null
+}
+$Wrapper.Pipe.Connect(5000)
+if (!$?) {
+	return
+}
+$Wrapper.Reader = New-Object System.IO.StreamReader($Wrapper.Pipe)
+$Wrapper.Writer = New-Object System.IO.StreamWriter($Wrapper.Pipe)
+$Wrapper.Writer.AutoFlush = $true
+for ($i = 1; $i -lt $args.length; $i++) {
+	$Wrapper.Writer.WriteLine($args[$i])
+}
+# We need to wait because the lines will not be written if we close the pipe immediately
+Start-Sleep -Seconds 1.5
+$Wrapper.Pipe.Close()

src/base/system.cpp

@@ -1437,7 +1437,7 @@ static int priv_net_close_all_sockets(NETSOCKET sock)
 }
 
 #if defined(CONF_FAMILY_WINDOWS)
-static char *windows_format_system_message(unsigned long error)
+char *windows_format_system_message(unsigned long error)
 {
 	WCHAR *wide_message;
 	const DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_MAX_WIDTH_MASK;

src/base/system.h

@@ -1147,6 +1147,20 @@ void net_unix_set_addr(UNIXSOCKETADDR *addr, const char *path);
  */
 void net_unix_close(UNIXSOCKET sock);
 
+#elif defined(CONF_FAMILY_WINDOWS)
+
+/**
+ * Formats a Windows error code as a human-readable string.
+ *
+ * @param error The Windows error code.
+ *
+ * @return A new string representing the error code.
+ *
+ * @remark Guarantees that result will contain zero-termination.
+ * @remark The result must be freed after it has been used.
+ */
+char *windows_format_system_message(unsigned long error);
+
 #endif
 
 /**

src/engine/client/client.cpp

@@ -3078,9 +3078,7 @@ void CClient::Run()
 	// process pending commands
 	m_pConsole->StoreCommands(false);
 
-#if defined(CONF_FAMILY_UNIX)
 	m_Fifo.Init(m_pConsole, g_Config.m_ClInputFifo, CFGFLAG_CLIENT);
-#endif
 
 	InitChecksum();
 	m_pConsole->InitChecksum(ChecksumData());
@@ -3341,9 +3339,7 @@ void CClient::Run()
 				break;
 		}
 
-#if defined(CONF_FAMILY_UNIX)
 		m_Fifo.Update();
-#endif
 
 		// beNice
 		auto Now = time_get_nanoseconds();
@@ -3395,9 +3391,7 @@ void CClient::Run()
 		m_GlobalTime = (time_get() - m_GlobalStartTime) / (float)time_freq();
 	}
 
-#if defined(CONF_FAMILY_UNIX)
 	m_Fifo.Shutdown();
-#endif
 
 	GameClient()->OnShutdown();
 	Disconnect();

src/engine/client/client.h

@@ -281,9 +281,7 @@ class CClient : public IClient, public CDemoPlayer::IListener
 
 	std::vector<SWarning> m_vWarnings;
 
-#if defined(CONF_FAMILY_UNIX)
 	CFifo m_Fifo;
-#endif
 
 	IOHANDLE m_BenchmarkFile;
 	int64_t m_BenchmarkStopTime;

src/engine/server/server.cpp

@@ -2598,9 +2598,7 @@ int CServer::Run()
 
 	m_Econ.Init(Config(), Console(), &m_ServerBan);
 
-#if defined(CONF_FAMILY_UNIX)
 	m_Fifo.Init(Console(), Config()->m_SvInputFifo, CFGFLAG_SERVER);
-#endif
 
 	char aBuf[256];
 	str_format(aBuf, sizeof(aBuf), "server name is '%s'", Config()->m_SvName);
@@ -2798,9 +2796,7 @@ int CServer::Run()
 
 				UpdateClientRconCommands();
 
-#if defined(CONF_FAMILY_UNIX)
 				m_Fifo.Update();
-#endif
 			}
 
 			// master server stuff
@@ -2879,9 +2875,7 @@ int CServer::Run()
 
 	m_Econ.Shutdown();
 
-#if defined(CONF_FAMILY_UNIX)
 	m_Fifo.Shutdown();
-#endif
 
 	GameServer()->OnShutdown();
 	m_pMap->Unload();

src/engine/server/server.h

@@ -221,9 +221,7 @@ public:
 	CSnapIDPool m_IDPool;
 	CNetServer m_NetServer;
 	CEcon m_Econ;
-#if defined(CONF_FAMILY_UNIX)
 	CFifo m_Fifo;
-#endif
 	CServerBan m_ServerBan;
 
 	IEngineMap *m_pMap;

src/engine/shared/config_variables.h

@@ -356,7 +356,7 @@ MACRO_CONFIG_INT(SvVotePause, sv_vote_pause, 1, 0, 1, CFGFLAG_SERVER, "Allow vot
 MACRO_CONFIG_INT(SvVotePauseTime, sv_vote_pause_time, 10, 0, 360, CFGFLAG_SERVER, "The time (in seconds) players have to wait in pause when paused by vote")
 MACRO_CONFIG_INT(SvTuneReset, sv_tune_reset, 1, 0, 1, CFGFLAG_SERVER, "Whether tuning is reset after each map change or not")
 MACRO_CONFIG_STR(SvResetFile, sv_reset_file, 128, "reset.cfg", CFGFLAG_SERVER, "File to execute on map change or reload to set the default server settings")
-MACRO_CONFIG_STR(SvInputFifo, sv_input_fifo, 128, "", CFGFLAG_SERVER, "Fifo file to use as input for server console")
+MACRO_CONFIG_STR(SvInputFifo, sv_input_fifo, 128, "", CFGFLAG_SERVER, "Fifo file (non-Windows) or Named Pipe (Windows) to use as input for server console")
 MACRO_CONFIG_INT(SvDDRaceTuneReset, sv_ddrace_tune_reset, 1, 0, 1, CFGFLAG_SERVER, "Whether DDRace tuning (sv_hit, sv_endless_drag and sv_old_laser) is reset after each map change or not")
 MACRO_CONFIG_INT(SvNamelessScore, sv_nameless_score, 1, 0, 1, CFGFLAG_SERVER, "Whether nameless tee has a score or not")
 MACRO_CONFIG_INT(SvTimeInBroadcastInterval, sv_time_in_broadcast_interval, 1, 0, 60, CFGFLAG_SERVER, "How often to update the broadcast time")
@@ -412,7 +412,7 @@ MACRO_CONFIG_INT(ClConfirmQuitTime, cl_confirm_quit_time, 20, -1, 1440, CFGFLAG_
 MACRO_CONFIG_STR(ClTimeoutCode, cl_timeout_code, 64, "", CFGFLAG_SAVE | CFGFLAG_CLIENT, "Timeout code to use")
 MACRO_CONFIG_STR(ClDummyTimeoutCode, cl_dummy_timeout_code, 64, "", CFGFLAG_SAVE | CFGFLAG_CLIENT, "Dummy Timeout code to use")
 MACRO_CONFIG_STR(ClTimeoutSeed, cl_timeout_seed, 64, "", CFGFLAG_SAVE | CFGFLAG_CLIENT, "Timeout seed")
-MACRO_CONFIG_STR(ClInputFifo, cl_input_fifo, 128, "", CFGFLAG_SAVE | CFGFLAG_CLIENT, "Fifo file to use as input for client console")
+MACRO_CONFIG_STR(ClInputFifo, cl_input_fifo, 128, "", CFGFLAG_SAVE | CFGFLAG_CLIENT, "Fifo file (non-Windows) or Named Pipe (Windows) to use as input for client console")
 MACRO_CONFIG_INT(ClConfigVersion, cl_config_version, 0, 0, 0, CFGFLAG_CLIENT | CFGFLAG_SAVE, "The config version. Helps newer clients fix bugs with older configs.")
 
 // demo editor

src/engine/shared/fifo.cpp

@@ -3,8 +3,6 @@
 #include <base/system.h>
 #if defined(CONF_FAMILY_UNIX)
 
-#include <engine/shared/config.h>
-
 #include <cstdlib>
 #include <fcntl.h>
 #include <sys/stat.h>
@@ -36,8 +34,8 @@ void CFifo::Init(IConsole *pConsole, char *pFifoFile, int Flag)
 
 		if(!S_ISFIFO(Attribute.st_mode))
 		{
-			dbg_msg("fifo", "can't remove file '%s', quitting", m_aFilename);
-			exit(2);
+			dbg_msg("fifo", "can't remove file '%s'", m_aFilename);
+			return;
 		}
 	}
 
@@ -48,11 +46,11 @@ void CFifo::Init(IConsole *pConsole, char *pFifoFile, int Flag)
 
 void CFifo::Shutdown()
 {
-	if(m_File >= 0)
-	{
-		close(m_File);
-		fs_remove(m_aFilename);
-	}
+	if(m_File < 0)
+		return;
+
+	close(m_File);
+	fs_remove(m_aFilename);
 }
 
 void CFifo::Update()
@@ -78,4 +76,127 @@ void CFifo::Update()
 	if(pCur < aBuf + Length) // missed the last line
 		m_pConsole->ExecuteLineFlag(pCur, m_Flag, -1);
 }
+
+#elif defined(CONF_FAMILY_WINDOWS)
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+void CFifo::Init(IConsole *pConsole, char *pFifoFile, int Flag)
+{
+	m_pConsole = pConsole;
+	if(pFifoFile[0] == '\0')
+	{
+		m_pPipe = INVALID_HANDLE_VALUE;
+		return;
+	}
+
+	str_copy(m_aFilename, "\\\\.\\pipe\\");
+	str_append(m_aFilename, pFifoFile, sizeof(m_aFilename));
+	m_Flag = Flag;
+
+	const int WLen = MultiByteToWideChar(CP_UTF8, 0, m_aFilename, -1, NULL, 0);
+	dbg_assert(WLen > 0, "MultiByteToWideChar failure");
+	wchar_t *pWide = static_cast<wchar_t *>(malloc(WLen * sizeof(*pWide)));
+	dbg_assert(MultiByteToWideChar(CP_UTF8, 0, m_aFilename, -1, pWide, WLen) == WLen, "MultiByteToWideChar failure");
+	m_pPipe = CreateNamedPipeW(pWide,
+		PIPE_ACCESS_DUPLEX,
+		PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_NOWAIT | PIPE_REJECT_REMOTE_CLIENTS,
+		PIPE_UNLIMITED_INSTANCES,
+		8192,
+		8192,
+		NMPWAIT_USE_DEFAULT_WAIT,
+		NULL);
+	free(pWide);
+	if(m_pPipe == INVALID_HANDLE_VALUE)
+	{
+		const DWORD LastError = GetLastError();
+		char *pErrorMsg = windows_format_system_message(LastError);
+		dbg_msg("fifo", "failed to create named pipe '%s' (%ld %s)", m_aFilename, LastError, pErrorMsg);
+		free(pErrorMsg);
+	}
+	else
+		dbg_msg("fifo", "created named pipe '%s'", m_aFilename);
+}
+
+void CFifo::Shutdown()
+{
+	if(m_pPipe == INVALID_HANDLE_VALUE)
+		return;
+
+	DisconnectNamedPipe(m_pPipe);
+	CloseHandle(m_pPipe);
+	m_pPipe = INVALID_HANDLE_VALUE;
+}
+
+void CFifo::Update()
+{
+	if(m_pPipe == INVALID_HANDLE_VALUE)
+		return;
+
+	if(!ConnectNamedPipe(m_pPipe, NULL))
+	{
+		const DWORD LastError = GetLastError();
+		if(LastError == ERROR_PIPE_LISTENING) // waiting for clients to connect
+			return;
+		if(LastError == ERROR_NO_DATA) // pipe was disconnected from the other end, also disconnect it from this end
+		{
+			// disconnect the previous client so we can connect to a new one
+			DisconnectNamedPipe(m_pPipe);
+			return;
+		}
+		if(LastError != ERROR_PIPE_CONNECTED) // pipe already connected, not an error
+		{
+			char *pErrorMsg = windows_format_system_message(LastError);
+			dbg_msg("fifo", "failed to connect named pipe '%s' (%ld %s)", m_aFilename, LastError, pErrorMsg);
+			free(pErrorMsg);
+			return;
+		}
+	}
+
+	while(true) // read all messages from the pipe
+	{
+		DWORD BytesAvailable;
+		if(!PeekNamedPipe(m_pPipe, NULL, 0, NULL, &BytesAvailable, NULL))
+		{
+			const DWORD LastError = GetLastError();
+			if(LastError != ERROR_BAD_PIPE) // pipe not connected, not an error
+			{
+				char *pErrorMsg = windows_format_system_message(LastError);
+				dbg_msg("fifo", "failed to peek at pipe '%s' (%ld %s)", m_aFilename, LastError, pErrorMsg);
+				free(pErrorMsg);
+			}
+			return;
+		}
+		if(BytesAvailable == 0) // pipe connected but no data available
+			return;
+
+		char *pBuf = static_cast<char *>(malloc(BytesAvailable + 1));
+		DWORD Length;
+		if(!ReadFile(m_pPipe, pBuf, BytesAvailable, &Length, NULL))
+		{
+			const DWORD LastError = GetLastError();
+			char *pErrorMsg = windows_format_system_message(LastError);
+			dbg_msg("fifo", "failed to read from pipe '%s' (%ld %s)", m_aFilename, LastError, pErrorMsg);
+			free(pErrorMsg);
+			free(pBuf);
+			return;
+		}
+		pBuf[Length] = '\0';
+
+		char *pCur = pBuf;
+		for(DWORD i = 0; i < Length; ++i)
+		{
+			if(pBuf[i] != '\n')
+				continue;
+			pBuf[i] = '\0';
+			m_pConsole->ExecuteLineFlag(pCur, m_Flag, -1);
+			pCur = pBuf + i + 1;
+		}
+		if(pCur < pBuf + Length) // missed the last line
+			m_pConsole->ExecuteLineFlag(pCur, m_Flag, -1);
+
+		free(pBuf);
+	}
+}
 #endif

src/engine/shared/fifo.h

@@ -3,14 +3,16 @@
 
 #include <engine/console.h>
 
-#if defined(CONF_FAMILY_UNIX)
-
 class CFifo
 {
 	IConsole *m_pConsole;
 	char m_aFilename[IO_MAX_PATH_LENGTH];
 	int m_Flag;
+#if defined(CONF_FAMILY_UNIX)
 	int m_File;
+#elif defined(CONF_FAMILY_WINDOWS)
+	void *m_pPipe;
+#endif
 
 public:
 	void Init(IConsole *pConsole, char *pFifoFile, int Flag);
@@ -19,5 +21,3 @@ public:
 };
 
 #endif
-
-#endif