Enable input/output buffering and fflush only explicitly

As suggested in old pull request: #39

BUILDING.md

@@ -1,18 +1,13 @@
 Building and installing
 -----------------------
 
-### Prerequisites
+#### Requirements & dependencies:
-
 - GCC compatible compiler
-- make
+- POSIX getopt support from **<unistd.h>**
-- POSIX.1 support
-   * getopt()
-   * strcasecmp()
-   * tcflush()
 
 ---
 
-### Compiling
+#### Compiling
 
     cc -std=gnu99 -Wpedantic -Wall -Wextra -Wno-gnu-zero-variadic-macro-arguments -O2 -o mcrcon mcrcon.c
     

CHANGELOG.md

@@ -1,12 +1,8 @@
 #### Version history:
 
-###### 0.8.0
+###### 0.7.3
- - 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 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()
@@ -15,7 +11,7 @@
 ###### 0.7.2
  - Quit gracefully when Ctrl-D or Ctrl+C is pressed
  - Remove "exit" and "quit" as quitting commands
-    * These are actual rcon commands on some servers
+    * these are actual rcon commands on some servers
  - Suppress compiler warning (strncpy)
  - Fix erroneous string length in packet building function
  - Fix typo in ANSI escape sequence for LCYAN

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-strong -D_FORTIFY_SOURCE=2 -fPIE -pie -Wl,-z,relro -Wl,-z,now -fno-common
+EXTRAFLAGS ?= -fstack-protector-all
 
 ifeq ($(OS), Windows_NT)
 	LINKER = -lws2_32

mcrcon.1

@@ -1,7 +1,7 @@
 .\" Process this file with
 .\" groff -man -Tascii mcrcon.1
 .\"
-.TH MCRCON 1 "December 2024" "Version 0.8.0"
+.TH MCRCON 1 "November 2024" "Version 0.7.3"
 .SH NAME 
 mcrcon \- send rcon commands to a Minecraft server
 .SH SYNOPSIS

mcrcon.c

@@ -31,20 +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"
+#define VERSION "0.7.3"
 #define IN_NAME "mcrcon"
 #define VER_STR IN_NAME" "VERSION" (built: "__DATE__" "__TIME__")"
 
@@ -59,8 +56,6 @@
 #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
@@ -109,16 +104,11 @@ static int  flag_disable_colors = 0;
 static int  flag_wait_seconds = 0;
 static int  global_connection_alive = 1;
 static bool global_valve_protocol = false;
-static bool global_minecraft_newline_fix = false;
 static int  global_rsock;
 
 #ifdef _WIN32
   // 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)
@@ -126,15 +116,6 @@ 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
@@ -144,9 +125,13 @@ 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;
@@ -234,16 +219,6 @@ 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
@@ -410,9 +385,6 @@ 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;
@@ -505,66 +477,52 @@ 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);
+		for (int i = 0; data[i] != 0; ++i) {
+			putchar(data[i]);
+		}
 		return;
 	}
 
-    // Newline fix for Minecraft
+	int i;
-    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;
+	// colors enabled so try to handle the bukkit colors for terminal
-    bool colors_detected = false;
-
-    for (i = 0; data[i] != 0; ++i)
-    {
-        if (data[i] == 0x0A) {
-            print_color(default_color);
-        }
-        else if(data[i] == 0xc2 && data[i + 1] == 0xa7) {
-            // Disable new line fixes if Bukkit colors are detected
-            colors_detected = true;
-            i += 2;
 	if (flag_disable_colors == 0) {
+		for (i = 0; data[i] != 0; ++i) {
+			if (data[i] == 0x0A) print_color(default_color);
+			else if(data[i] == 0xc2 && data[i + 1] == 0xa7) {
+				i += 2;
 				print_color(data[i]);
-            }
 				continue;
 			}
-
-        // Add missing newlines
-        if (colors_detected == false && global_minecraft_newline_fix && data[i] == '/') {
-            slash ? putchar('\n') : (slash = true);
-        }
-
 			putchar(data[i]);
 		}
 		print_color(default_color); // cancel coloring
-
+	}
-    // print newline if string has no newline
+	// strip colors
-    if (data[i - 1] != '\n') {
+	else {
-        putchar('\n');
+		for (i = 0; data[i] != 0; ++i) {
+			if (data[i] == 0xc2 && data[i + 1] == 0xa7) {
+				i += 2;
+				continue;
+			}	
+			putchar(data[i]);
+		}
 	}
 
+	// print newline if string has no newline
+	if (data[i - 1] != 10 && data[i - 1] != 13) {
+		putchar('\n');
+	}
 	fflush(stdout);
 }
 
@@ -620,11 +578,10 @@ bool rcon_auth(int sock, char *passwd)
 	return packet->id == -1 ? false : true;
 }
 
+// TODO: Create function that sends two packets in one send() call
+//       This is important so multipacket guard packet is sent right after real packet
 int rcon_command(int sock, char *command)
 {
-    if (global_valve_protocol == false && strcasecmp(command, "help") == 0)
-        global_minecraft_newline_fix = true;
-
 	rc_packet *packet = packet_build(RCON_PID, RCON_EXEC_COMMAND, command);
 	if (packet == NULL) {
 		log_error("Error: packet build() failed!\n");
@@ -654,10 +611,10 @@ int rcon_command(int sock, char *command)
 	FD_ZERO(&read_fds);
 	FD_SET(sock, &read_fds);
 
-    // Set 5 second timeout
+	// Set 1.5 second timeout in case there is no response for multipacket guard
 	struct timeval timeout = {0};
-    timeout.tv_sec = 5;
+	timeout.tv_sec = 1;
-    timeout.tv_usec = 0;
+	timeout.tv_usec = 500000;
 
 	int incoming = 0;
 
@@ -676,7 +633,7 @@ int rcon_command(int sock, char *command)
 
 		if (packet->id == 0xBADA55) break;
 
-        if (flag_silent_mode == false) {
+		if (!flag_silent_mode) {
 			if (packet->size > 10)
 			packet_print(packet);
 		}
@@ -686,7 +643,6 @@ int rcon_command(int sock, char *command)
 			log_error("Error: select() failed!\n");
 			return 0;
 		}
-
 		incoming = (result > 0 && FD_ISSET(sock, &read_fds));
 	}
 	while(incoming);
@@ -722,7 +678,7 @@ int run_terminal_mode(int sock)
 {
 	char command[MAX_COMMAND_LENGTH] = {0};
 
-    puts("Logged in. Press Ctrl-D or Ctrl-C to disconnect.");
+	puts("Logged in.\nType 'Q' or press Ctrl-D / Ctrl-C to disconnect.");
 
 	while (global_connection_alive) {
 		putchar('>');
@@ -731,6 +687,8 @@ 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;
@@ -740,80 +698,22 @@ int run_terminal_mode(int sock)
 		/* Special case for "stop" command to prevent server-side bug.
 		 * https://bugs.mojang.com/browse/MC-154617
 		 * 
-         * NOTE: Not sure if this still a problem?!
+		 * NOTE: This is hacky workaround which should be handled better to
+		 *       ensure compatibility with other servers using source RCON.
+		 * NOTE: strcasecmp() is POSIX function.
 		 */
-        if (global_valve_protocol == false && strcasecmp(command, "stop") == 0) {
+		if (strcasecmp(command, "stop") == 0) {
-            // Timeout to before checking if connection was closed
+			break;
-            #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));
@@ -825,7 +725,14 @@ int get_line(char *buffer, int bsize)
 
 	// remove unwanted characters from the buffer
 	buffer[strcspn(buffer, "\r\n")] = '\0';
+
 	int len = strlen(buffer);
 
+	// clean input buffer if needed 
+	if (len == bsize - 1) {
+		int ch;
+		while ((ch = getchar()) != '\n' && ch != EOF);
+	}
+
 	return len;
 }