Oops, uncomment struct field

- Remove "ginstall" as "install" replacement on macOS
- Remove "-D" flag from "install" parameters

.travis.yml

@@ -1,20 +0,0 @@
-language: c
-sudo: false
-dist: trusty
-cache:
-  ccache: true
-compiler:
-- gcc
-- clang
-env:
-  global:
-  - EXTRAFLAGS='-v'
-  - PREFIX="${HOME}"
-install:
-- 'true'
-script:
-- make
-- ./mcrcon -h
-- ./mcrcon -v
-- make install
-- make uninstall

CHANGELOG.md

@@ -1,11 +1,15 @@
 #### Version history:
 
+###### 0.7.3
+ - Add support to Valve style rcon authentication
+ - Change maximum packet size to correct value (4096 -> 4106)
+ 
 ###### 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
  - Suppress compiler warning (strncpy)
- - fix erroneous string length in packet building function
+ - Fix erroneous string length in packet building function
  - Fix typo in ANSI escape sequence for LCYAN
  - Make stdout and stderr unbuffered
 

INSTALL.md

@@ -1,11 +1,11 @@
 Building and installing
-------------------------
+-----------------------
 
 Only dependency is C library and POSIX getopt support. 
 
 Compiling with GCC or CLANG:
 
-    cc -std=gnu99 -Wpedantic -Wall -Wextra -Os -s -o mcrcon mcrcon.c
+    cc -std=gnu99 -Wpedantic -Wall -Wextra -O2 -o mcrcon mcrcon.c
     
 Note: on Windows remember to link with winsock by adding `-lws2_32` to your compiler command line.
 

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2012-2021, Tiiffi <tiiffi at gmail>
+Copyright (c) 2012-2024, Tiiffi <tiiffi at gmail>
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -18,4 +18,3 @@ freely, subject to the following restrictions:
 
   3. This notice may not be removed or altered from any source
   distribution.
-  

Makefile

@@ -4,7 +4,7 @@
 #   make
 #
 # Windows cross compile:
-#   i686-w64-mingw32-gcc -std=gnu99 -Wall -Wextra -Wpedantic -Os -s -o mcrcon.exe mcrcon.c -lws2_32
+#   x86_64-w64-mingw32-gcc -std=gnu99 -Wall -Wextra -Wpedantic -O2 -fstack-protector-all -o mcrcon.exe mcrcon.c -lws2_32
 
 EXENAME = mcrcon
 PREFIX ?= /usr/local
@@ -14,8 +14,8 @@ LINKER =
 RM = rm -v -f
 
 CC = gcc
-CFLAGS = -std=gnu99 -Wall -Wextra -Wpedantic -Os -s
+CFLAGS = -std=gnu99 -Wall -Wextra -Wpedantic -O2
-EXTRAFLAGS ?= -fstack-protector-strong
+EXTRAFLAGS ?= -fstack-protector-all
 
 ifeq ($(OS), Windows_NT)
 	LINKER = -lws2_32
@@ -23,11 +23,6 @@ ifeq ($(OS), Windows_NT)
 	RM = cmd /C del /F
 endif
 
-ifeq ($(shell uname), Darwin)
-	INSTALL = ginstall
-	CFLAGS = -std=gnu99 -Wall -Wextra -Wpedantic -Os
-endif
-
 .PHONY: all
 all: $(EXENAME)
 
@@ -37,8 +32,8 @@ $(EXENAME): mcrcon.c
 ifneq ($(OS), Windows_NT)
 .PHONY: install
 install:
-	$(INSTALL) -vD $(EXENAME) $(DESTDIR)$(PREFIX)/bin/$(EXENAME)
+	$(INSTALL) -v $(EXENAME) $(DESTDIR)$(PREFIX)/bin/$(EXENAME)
-	$(INSTALL) -vD -m 0644 mcrcon.1 $(DESTDIR)$(PREFIX)/share/man/man1/mcrcon.1
+	$(INSTALL) -v -m 0644 mcrcon.1 $(DESTDIR)$(PREFIX)/share/man/man1/mcrcon.1
 	@echo "\nmcrcon installed. Run 'make uninstall' if you want to uninstall.\n"
 
 .PHONY: uninstall

README.md

@@ -4,30 +4,36 @@ mcrcon is console based Minecraft [rcon](https://developer.valvesoftware.com/wik
 
 ---
 
-### Installing:
+### Installing
 
-##### via packet manager:
+##### Binary releases
-See https://pkgs.org/download/mcrcon for available packages in various Linux distros (note that available packages might be outdated).
 
-- Gentoo Linux: https://packages.gentoo.org/packages/games-util/mcrcon
+Pre-built binaries are provided for Linux and Windows: https://github.com/Tiiffi/mcrcon/releases/latest
-- Arch Linux: https://aur.archlinux.org/packages/mcrcon/
 
-##### building from sources:
+##### Via package manager
+See https://pkgs.org/download/mcrcon and https://repology.org/project/mcrcon/packages for available packages in various Linux distros (note that some packages might be outdated).
+
+- Fedora: https://packages.fedoraproject.org/pkgs/mcrcon/mcrcon/
+- Gentoo: https://packages.gentoo.org/packages/games-util/mcrcon
+- Arch: https://aur.archlinux.org/packages/mcrcon/
+- NixOS: https://search.nixos.org/packages?show=mcrcon
+- Snapcraft: https://snapcraft.io/mcrcon-nsg
+- Scoop: https://scoop.sh/#/apps?q=mcrcon
+
+##### Building from sources
 ```sh
 git clone https://github.com/Tiiffi/mcrcon.git
 cd mcrcon
 make
+
+# install is optional
 sudo make install
 ```
 Check [INSTALL.md](INSTALL.md) for more details.
 
-Precompiled binaries (if provided)*: https://github.com/Tiiffi/mcrcon/releases/latest
-
-<sub>*At the moment binaries are provided for Linux and Windows.</sub>
-
 ---
 
-### Usage:
+### Usage
 mcrcon [OPTIONS] [COMMANDS]
 
 Sends rcon commands to Minecraft server.
@@ -56,15 +62,18 @@ MCRCON_PASS
 - Command-line options will override environment variables
 - Rcon commands with spaces must be enclosed in quotes
 
-Example:
+###### Example:
-> Send three commands ("say", "save-all", "stop") and wait five seconds between the commands.
+Send three commands ("say", "save-all", "stop") and wait five seconds between the commands:
 
-  ```mcrcon -H my.minecraft.server -p password -w 5 "say Server is restarting!" save-all stop```
+```sh
+mcrcon -H my.minecraft.server -p password -w 5 "say Server is restarting!" save-all stop
+```
 
 ---
 
-##### Enable rcon on server
+##### How to enable rcon on a Minecraft Server 
-Remember to enable rcon by adding following lines to [```server.properties```](https://minecraft.gamepedia.com/Server.properties) file.
+
+Enable rcon by adding following lines to [```server.properties```](https://minecraft.gamepedia.com/Server.properties) configuration file.
 ```
 enable-rcon=true
 rcon.port=25575
@@ -73,19 +82,25 @@ rcon.password=your_rcon_pasword
 
 ---
 
-##### Contact:
+### Contact
 
 * WWW:            https://github.com/Tiiffi/mcrcon/
 * MAIL:           tiiffi+mcrcon at gmail
-* BUG REPORTS:    https://github.com/Tiiffi/mcrcon/issues/
+* ISSUES:         https://github.com/Tiiffi/mcrcon/issues/
+
+When reporting issues, please provide the following information:
+
+- Version of mcrcon: Please specify the precise version number
+- Game: Indicate the specific game server you're using (e.g., Minecraft, Valve Source Engine game, ARK, ...)
+- Server version: Provide the exact version of the game server
+- Mods and Extensions: List all mods and extensions used, including their versions
+- Issue Description: Clearly describe the problem you're encountering and the expected behavior.
+- Steps to reproduce
+
+If you're tech-savvy, consider providing a packet capture file (PCAP). Remember to use a fake password.
 
 ---
 
 ### License
 
 This project is licensed under the zlib License - see the [LICENSE](LICENSE) file for details.
-
----
-
-<sub>Master:</sub> ![Master build](https://api.travis-ci.org/Tiiffi/mcrcon.svg?branch=master)
-<sub>Develop:</sub> ![Develop build](https://api.travis-ci.org/Tiiffi/mcrcon.svg?branch=develop)

create_shortcut.bat

@@ -0,0 +1,31 @@
+@echo off
+@cls
+
+@set /p host="Enter host (default: "127.0.0.1"): "
+@if "%host%"=="" set host=127.0.0.1
+
+@set /p port="Enter port (default: 25575): "
+@if "%port%"=="" set port=25575
+
+@set /p passwd="Enter password: "
+@if "%passwd%"=="" set passwd=
+
+set name=connect_%host%-%port%
+
+@set /p name="Enter shortcut name (default: "%name%.bat"): "
+@if "%name%"=="" set name=connect_%host%-%port%
+
+set command=@mcrcon.exe -t -H %host% -P %port% -p %passwd%
+
+@echo %command% >> %name%.bat
+@echo.
+@echo Command: "%command%"
+@echo.
+@echo Shortcut "%name%.bat" created!
+@echo.
+
+@set "host="
+@set "port="
+@set "passwd="
+
+@pause

launch.bat

@@ -0,0 +1,29 @@
+@echo off
+@cls
+
+@if not exist mcrcon.exe (
+  @echo ERROR: Cannot find "mcrcon.exe". Bailing out!
+  @echo.
+  @pause
+  @exit
+)
+
+@set /p host="Enter host (default: 127.0.0.1): "
+@if "%host%"=="" set host=127.0.0.1
+
+@set /p port="Enter port (default: 25575): "
+@if "%port%"=="" set port=25575
+
+@set /p passwd="Enter password: "
+@if "%passwd%"=="" set passwd=
+
+@echo.
+mcrcon.exe -t -H %host% -P %port% -p %passwd%
+@echo.
+
+@set "host="
+@set "port="
+@set "passwd="
+
+@pause
+

mcrcon.1

@@ -1,7 +1,7 @@
 .\" Process this file with
 .\" groff -man -Tascii mcrcon.1
 .\"
-.TH MCRCON 1 "October 2021" "Version 0.7.2"
+.TH MCRCON 1 "November 2024" "Version 0.7.3"
 .SH NAME 
 mcrcon \- send rcon commands to a Minecraft server
 .SH SYNOPSIS

mcrcon.c

@@ -47,7 +47,7 @@
     #include <netdb.h>
 #endif
 
-#define VERSION "0.7.2"
+#define VERSION "0.7.3"
 #define IN_NAME "mcrcon"
 #define VER_STR IN_NAME" "VERSION" (built: "__DATE__" "__TIME__")"
 
@@ -57,17 +57,46 @@
 #define RCON_AUTH_RESPONSE      2
 #define RCON_PID                0xBADC0DE
 
-#define DATA_BUFFSIZE 4096
+/* NOTE: This is confusing. What is the real max packet size?
+ *       Are null bytes included? Are both null bytes included?
+ *       Perhaps payload end indicator is uin16_t with zero value?
+ */
+#define DATA_BUFFSIZE   4098 // 2 bytes extra over 4096
+#define MAX_PACKET_SIZE 4106
+#define MIN_PACKET_SIZE 10
 
-// rcon packet structure
+// rcon packet structure,
+// NOTE(Tiiffi): Alignment problem!
 typedef struct _rc_packet {
-    int size;
+    int32_t size;
-    int id;
+    int32_t id;
-    int cmd;
+    int32_t cmd;
     char data[DATA_BUFFSIZE];
     // ignoring string2 for now
 } rc_packet;
+// __attribute__((packed))
 
+/* TODO(Tiiffi):
+ *
+ *  Correct packet structure is propably something like this:
+ *
+ *  +---------------------------+
+ *  | Size (4 bytes, int)       |  Total packet size (excluding this field)
+ *  +---------------------------+
+ *  | ID (4 bytes, int)         |
+ *  +---------------------------+
+ *  | Type (4 bytes, int)       |
+ *  +---------------------------+
+ *  | Payload (variable length) |  Command or response string (up to 4096 bytes)
+ *  | (null-terminated string)  |
+ *  +---------------------------+
+ *  | Null Terminator (2 bytes, |  16-bit integer set to zero (0x0000)
+ *  | 16-bit int)               |  Could be also interpreted as two null bytes
+ *  +---------------------------+
+ *
+ *  Maximum size 4110 including size field, 4106 excluding size field.
+ *  Take care with the aligment!
+ */
 
 // ===================================
 //  FUNCTION DEFINITIONS              
@@ -209,7 +238,7 @@ int main(int argc, char *argv[])
 
 	if (pass == NULL) {
 		puts("You must give password (-p password).\nTry 'mcrcon -h' or 'man mcrcon' for help.");
-		return 0;
+		exit(EXIT_FAILURE);
 	}
 
 	if(optind == argc && terminal_mode == 0)
@@ -400,7 +429,7 @@ int net_send_packet(int sd, rc_packet *packet)
 	int bytesleft;	// bytes left to send 
 	int ret = -1;
 
-	bytesleft = len = packet->size + sizeof(int);
+	bytesleft = len = packet->size + sizeof(int32_t);
 
 	while (total < len) {
 		ret = send(sd, (char *) packet + total, bytesleft, 0);
@@ -414,12 +443,12 @@ int net_send_packet(int sd, rc_packet *packet)
 
 rc_packet *net_recv_packet(int sd)
 {
-	int psize;
+	int32_t psize;
 	static rc_packet packet = {0, 0, 0, { 0x00 }};
 
 	// packet.size = packet.id = packet.cmd = 0;
 
-	int ret = recv(sd, (char *) &psize, sizeof(int), 0);
+	int ret = recv(sd, (char *) &psize, sizeof(psize), 0);
 
 	if (ret == 0) {
 		fprintf(stderr, "Connection lost.\n");
@@ -427,17 +456,18 @@ rc_packet *net_recv_packet(int sd)
 		return NULL;
 	}
 
-	if (ret != sizeof(int)) {
+	if (ret != sizeof(psize)) {
 		fprintf(stderr, "Error: recv() failed. Invalid packet size (%d).\n", ret);
 		global_connection_alive = 0;
 		return NULL;
 	}
 
 	// NOTE(Tiiffi): This should fail if size is out of spec!
-	if (psize < 10 || psize > DATA_BUFFSIZE) {
+	if (psize < MIN_PACKET_SIZE || psize > MAX_PACKET_SIZE) {
-		fprintf(stderr, "Warning: invalid packet size (%d). Must over 10 and less than %d.\n", psize, DATA_BUFFSIZE);
+		fprintf(stderr, "Warning: invalid packet size (%d). Must over 10 and less than %d.\n", psize, MAX_PACKET_SIZE);
 
-		if(psize > DATA_BUFFSIZE  || psize < 0) psize = DATA_BUFFSIZE;
+		// WARNING(Tiiffi): This is probably not the way to go. Probably should just fail and exit.
+		if(psize > MAX_PACKET_SIZE || psize < 0) psize = MAX_PACKET_SIZE;
 		net_clean_incoming(sd, psize);
 
 		return NULL;
@@ -447,8 +477,8 @@ rc_packet *net_recv_packet(int sd)
 
 	int received = 0;
 	while (received < psize) {
-		ret = recv(sd, (char *) &packet + sizeof(int) + received, psize - received, 0);
+		ret = recv(sd, (char *) &packet + sizeof(int32_t) + received, psize - received, 0);
-		if (ret == 0) { /* connection closed before completing receving */
+		if (ret == 0) {
 			fprintf(stderr, "Connection lost.\n");
 			global_connection_alive = 0;
 			return NULL;
@@ -568,6 +598,11 @@ rc_packet *packet_build(int id, int cmd, char *s1)
 {
 	static rc_packet packet = {0, 0, 0, { 0x00 }};
 
+	// NOTE(Tiiffi): Issue report states that outgoing payload has max size of 1460 bytes:
+	//				 https://github.com/Tiiffi/mcrcon/issues/45#issuecomment-1000940814
+	//				 https://mctools.readthedocs.io/en/master/rcon.html
+	//				 Have to do some testing to confirm!
+
 	// size + id + cmd + s1 + s2 NULL terminator
 	int len = strlen(s1);
 	if (len >= DATA_BUFFSIZE) {
@@ -575,7 +610,7 @@ rc_packet *packet_build(int id, int cmd, char *s1)
 		return NULL;
 	}
 
-	packet.size = sizeof(int) * 2 + len + 2;
+	packet.size = sizeof packet.size * 2 + len + 2;
 	packet.id = id;
 	packet.cmd = cmd;
 	strncpy(packet.data, s1, DATA_BUFFSIZE - 1);
@@ -595,10 +630,18 @@ int rcon_auth(int sock, char *passwd)
 	if (!ret)
 		return 0; // send failed
 
+receive:
 	packet = net_recv_packet(sock);
 	if (packet == NULL)
 		return 0;
 
+	/* Valve rcon sends empty "RCON_RESPONSEVALUE" packet before real auth response
+	 * so we have to check packet type and try again if necessary.
+	 */
+	if (packet->cmd != RCON_AUTH_RESPONSE) {
+		goto receive;
+	}
+
 	// return 1 if authentication OK
 	return packet->id == -1 ? 0 : 1;
 }
@@ -653,7 +696,7 @@ int run_commands(int argc, char *argv[])
 int run_terminal_mode(int sock)
 {
 	int ret = 0;
-	char command[DATA_BUFFSIZE] = {0x00};
+	char command[DATA_BUFFSIZE] = {0};
 
 	puts("Logged in.\nType 'Q' or press Ctrl-D / Ctrl-C to disconnect.");