Implement platform specific input buffer flushing

CHANGELOG.md

@@ -2,10 +2,11 @@
 
 ###### 0.8.0
  - Implement support for multipacket responses
- - Add support to Valve style rcon authentication
+ - Add support for Valve style rcon authentication
+ - Add experimental UTF-8 support for Windows
  - Change maximum packet size to correct value (4096 -> 4106)
- - Attempt to add missing newlines in Minecraft servers
-    * Currently implemented only for the 'help' command
+ - Attempt to add missing newlines in bugged Minecraft servers
+    * Implemented for responses to the 'help' command and unknown commands
  - Print auth failed message to stderr instead of stdout
  - Fail immediately if received packet size is out of spec
  - Return proper exit code from run_terminal_mode()

Makefile

@@ -15,7 +15,7 @@ RM = rm -v -f
 
 CC ?= gcc
 CFLAGS = -std=gnu99 -Wall -Wextra -Wpedantic -Wno-gnu-zero-variadic-macro-arguments -O2
-EXTRAFLAGS ?= -fstack-protector-all
+EXTRAFLAGS ?= -fstack-protector-strong -D_FORTIFY_SOURCE=2 -fPIE -pie -Wl,-z,relro -Wl,-z,now -fno-common
 
 ifeq ($(OS), Windows_NT)
 	LINKER = -lws2_32

mcrcon.c

@@ -31,14 +31,17 @@
 #include <errno.h>
 #include <unistd.h>
 
-
 #ifdef _WIN32
 	#include <winsock2.h>
 	#include <windows.h>
 	#include <ws2tcpip.h>
+	#include <fcntl.h>
+	#include <wchar.h>
 #else
 	#include <sys/socket.h>
+	#include <sys/select.h>
 	#include <netdb.h>
+	#include <termios.h>
 #endif
 
 #define VERSION "0.8.0"
@@ -56,6 +59,8 @@
 #define MAX_PACKET_SIZE		4106 // id (4) + cmd (4) + DATA_BUFFSIZE
 #define MIN_PACKET_SIZE		10   // id (4) + cmd (4) + two empty strings (2)
 
+#define MAX_WAIT_TIME 600
+
 #define log_error(fmt, ...) fprintf(stderr, fmt,  ##__VA_ARGS__);
 
 // rcon packet structure
@@ -108,8 +113,12 @@ static bool global_minecraft_newline_fix = false;
 static int  global_rsock;
 
 #ifdef _WIN32
-  // console coloring on windows
-  HANDLE console_handle;
+// console coloring on windows
+HANDLE console_handle;
+
+// console code pages
+UINT old_output_codepage;
+UINT old_input_codepage;
 #endif
 
 // safety stuff (windows is still misbehaving)
@@ -117,6 +126,15 @@ void exit_proc(void)
 {
 	if (global_rsock != -1)
 		net_close(global_rsock);
+
+	#ifdef _WIN32
+	// Restore previous code pages
+	SetConsoleOutputCP(old_output_codepage);
+	SetConsoleCP(old_input_codepage);
+
+	// Set back to binary mode
+	_setmode(_fileno(stdin), _O_BINARY);
+	#endif
 }
 
 // TODO: check exact windows and linux behaviour
@@ -126,13 +144,9 @@ void sighandler(int sig)
 		putchar('\n');
 
 	global_connection_alive = 0;
-	#ifndef _WIN32
 	exit(EXIT_SUCCESS);
-	#endif
 }
 
-#define MAX_WAIT_TIME 600
-
 unsigned int mcrcon_parse_seconds(char *str)
 {
 	char *end;
@@ -220,6 +234,16 @@ int main(int argc, char *argv[])
 	console_handle = GetStdHandle(STD_OUTPUT_HANDLE);
 	if (console_handle == INVALID_HANDLE_VALUE)
 		console_handle = NULL;
+
+	// Set the output and input code pages to utf-8
+	old_output_codepage = GetConsoleOutputCP();
+	old_input_codepage = GetConsoleCP();
+
+	SetConsoleOutputCP(CP_UTF8);
+	SetConsoleCP(CP_UTF8);
+
+	// Set the file translation mode to UTF16
+	_setmode(_fileno(stdin), _O_U16TEXT);
 	#endif
 
 	// open socket
@@ -386,6 +410,9 @@ bool net_send_packet(int sd, rc_packet *packet)
 	return true;
 }
 
+
+// TODO: Fix the wonky behaviour when server quit/exit/stop/close
+//       command is issued. Client should close gracefully without errors.
 rc_packet *net_recv_packet(int sd)
 {
 	int32_t psize;
@@ -478,20 +505,32 @@ void print_color(int color)
 void packet_print(rc_packet *packet)
 {
 	uint8_t *data = packet->data;
+	int i;
 
 	if (flag_raw_output == 1) {
 		fputs((char *) data, stdout);
 		return;
 	}
 
-	int i;
+	// Newline fix for Minecraft
+	if (global_valve_protocol == false) {
+		const char test[] = "Unknown or incomplete command, see below for error";
+		size_t test_size = sizeof test - 1;
+		if (strncmp((char *) data, test, test_size) == 0) {
+			fwrite(data, test_size, 1, stdout);
+			putchar('\n');
+			data = &data[test_size];
+		}
+	}
+
 	int default_color = 0;
 
 	#ifdef _WIN32
 	CONSOLE_SCREEN_BUFFER_INFO console_info;
 	if (GetConsoleScreenBufferInfo(console_handle, &console_info) != 0) {
 		default_color = console_info.wAttributes + 0x30;
-		} else default_color = 0x37;
+	}
+	else default_color = 0x37;
 	#endif
 
 	bool slash = false;
@@ -512,6 +551,7 @@ void packet_print(rc_packet *packet)
 			continue;
 		}
 
+		// Add missing newlines
 		if (colors_detected == false && global_minecraft_newline_fix && data[i] == '/') {
 			slash ? putchar('\n') : (slash = true);
 		}
@@ -563,7 +603,7 @@ bool rcon_auth(int sock, char *passwd)
 		return 0; // send failed
 	}
 
-receive:
+	receive:
 	packet = net_recv_packet(sock);
 	if (packet == NULL)
 		return 0;
@@ -682,7 +722,7 @@ int run_terminal_mode(int sock)
 {
 	char command[MAX_COMMAND_LENGTH] = {0};
 
-	puts("Logged in.\nType 'Q' or press Ctrl-D / Ctrl-C to disconnect.");
+	puts("Logged in. Press Ctrl-D or Ctrl-C to disconnect.");
 
 	while (global_connection_alive) {
 		putchar('>');
@@ -691,8 +731,6 @@ int run_terminal_mode(int sock)
 		int len = get_line(command, MAX_COMMAND_LENGTH);
 		if (len < 1) continue;
 
-		if (strcasecmp(command, "Q") == 0) break;
-
 		if (len > 0 && global_connection_alive) {
 			if (!rcon_command(sock, command)) {
 				return EXIT_FAILURE;
@@ -702,22 +740,80 @@ int run_terminal_mode(int sock)
 		/* Special case for "stop" command to prevent server-side bug.
 		 * https://bugs.mojang.com/browse/MC-154617
 		 *
-		 * NOTE: This is hacky workaround which should be handled better to
-		 *       ensure compatibility with other servers using source RCON.
-		 * NOTE: strcasecmp() is POSIX function.
+		 * NOTE: Not sure if this still a problem?!
 		 */
-		if (strcasecmp(command, "stop") == 0) {
-			break;
+		if (global_valve_protocol == false && strcasecmp(command, "stop") == 0) {
+			// Timeout to before checking if connection was closed
+			#ifdef _WIN32
+			Sleep(2 * 1000);
+			#else
+			sleep(2);
+			#endif
+
+			char tmp[1];
+			#ifdef _WIN32
+			// TODO: More Windows side testing!
+			int result = recv(sock, tmp, sizeof(tmp), MSG_PEEK | 0);
+			#else
+			int result = recv(sock, tmp, sizeof(tmp), MSG_PEEK | MSG_DONTWAIT);
+			#endif
+			if (result == 0) {
+				break; // Connection closed
+			}
+			// TODO: Check for return values and errors!
 		}
 	}
 
 	return EXIT_SUCCESS;
 }
 
+#ifdef _WIN32
+char *utf8_getline(char *buf, int size, FILE *stream)
+{
+	// Widechar fgets
+	wchar_t in[MAX_COMMAND_LENGTH] = {0};
+
+	wchar_t *result = fgetws(in, MAX_COMMAND_LENGTH, stream);
+	if (result == NULL) {
+		return NULL;
+	}
+
+	// Calculates UTF-8 buffer size
+	int required_size = WideCharToMultiByte(CP_UTF8, 0, in, -1, NULL, 0, NULL, NULL);
+	if (size < required_size) {
+		// TODO: Proper error handling & reporting
+		return NULL;
+	}
+
+	if (WideCharToMultiByte(CP_UTF8, 0, in, -1, buf, size, NULL, NULL) == 0) {
+		// TODO: Proper error handling & reporting
+		return NULL;
+	}
+
+	return buf;
+}
+#endif
+
+void flush_input(void)
+{
+	#ifdef _WIN32
+	FlushConsoleInputBuffer(console_handle);
+	#else
+	tcflush(STDIN_FILENO, TCIFLUSH);
+	#endif
+}
+
 // gets line from stdin and deals with rubbish left in the input buffer
 int get_line(char *buffer, int bsize)
 {
+	#ifdef _WIN32
+	char *ret = utf8_getline(buffer, bsize, stdin);
+	#else
 	char *ret = fgets(buffer, bsize, stdin);
+	#endif
+
+	flush_input();
+
 	if (ret == NULL) {
 		if (ferror(stdin)) {
 			log_error("Error %d: %s\n", errno, strerror(errno));
@@ -729,14 +825,17 @@ int get_line(char *buffer, int bsize)
 
 	// remove unwanted characters from the buffer
 	buffer[strcspn(buffer, "\r\n")] = '\0';
-
 	int len = strlen(buffer);
 
+#if 0
 	// clean input buffer if needed
+	#ifndef _WIN32
 	if (len == bsize - 1) {
 		int ch;
 		while ((ch = getchar()) != '\n' && ch != EOF);
 	}
+	#endif
+#endif
 
 	return len;
 }