initial

5 files changed, 262 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..722a501
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+build/
+obj/
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..3c18490
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,39 @@
+CC              = clang
+CFLAGS          = -Wall
+LDFLAGS         =
+BUILDDIR        = build
+SOURCEDIR       = src
+OBJECTDIR       = obj
+
+OUTPUT          = program
+
+SRCS = $(wildcard $(SOURCEDIR)/*.c)
+OBJS = $(SRCS:.c=.o)
+OBJ  = $(OBJS:$(SOURCEDIR)/%=$(OBJECTDIR)/%)
+
+build: dir $(OBJ)
+	@echo LD $(OBJ)
+	@$(CC) $(CFLAGS) -o $(BUILDDIR)/$(OUTPUT) $(OBJ) $(LDFLAGS)
+
+debug: CFLAGS += -g -D _DEBUG
+debug: build;
+
+dir:
+	@mkdir -p $(OBJECTDIR)
+	@mkdir -p $(BUILDDIR)
+
+$(OBJECTDIR)/%.o: $(SOURCEDIR)/%.c
+	@echo CC $<
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+.PHONY: clean
+clean:	
+	@echo RM $(OBJ)
+	@echo RM $(BUILDDIR)/$(OUTPUT)
+	@rm -df  $(OBJ)
+	@rm -Rdf $(BUILDDIR) $(OBJECTDIR)
+
+all: clean build
+
+run: build
+	@$(BUILDDIR)/$(OUTPUT)
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..c4cc3a1
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,83 @@
+/*
+ * src/main.c
+ * (c) 2020 Jonas Gunz <himself@jonasgunz.de>
+ * License: 
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <unistd.h>
+
+#include "rcon.h"
+
+typedef struct program_params_s {
+	char* 	host;
+	char*	port;
+	char*	password;
+	char*	command;
+} program_params_t;
+
+program_params_t parse_args ( int argc, char* argv[] );
+
+int main( int argc, char* argv[] ) {
+	program_params_t args = parse_args( argc, argv );
+
+	int sock = -1;
+	int ret = 0;
+	struct addrinfo hints, *result, *iter;
+	char recvbuf [ RCON_RECV_PKGSIZE ];
+	char sendbuf [ RCON_SEND_PKGSIZE ];
+
+	memset ( &hints, 0, sizeof( struct addrinfo ) );
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+
+	ret = getaddrinfo ( args.host, args.port, &hints, &result );
+	if ( ret ) {
+		fprintf ( stderr, "getaddrinfo: %s\n", gai_strerror(ret) );
+		exit ( EXIT_FAILURE );
+	}
+
+	for ( iter = result; iter != NULL; iter = iter->ai_next ) {
+		sock = socket( result->ai_family, result->ai_socktype, result->ai_protocol );
+		if ( socket < 0 )
+			continue;
+
+		if ( connect ( sock, iter->ai_addr, iter->ai_addrlen ) != -1 )
+			break;
+
+		close (sock);
+	}
+
+	if ( ! iter ) {
+		fprintf ( stderr, "Connection failed.\n" );
+		exit ( EXIT_FAILURE );
+	}
+
+	fprintf ( stderr, "Connection successful.\n" );
+
+	rcon_packet_t pack = {0,1337,RCON_LOGIN,args.password, strlen(args.password)}, rcon_result;
+
+	ret = send ( sock, sendbuf, ret, 0 );
+
+	ret = recv ( sock, recvbuf, RCON_RECV_PKGSIZE, 0);
+	rcon_parse_packet ( &rcon_result, recvbuf, ret );
+
+	close (sock);
+
+	//printf("%s\n%s", sendbuf, recvbuf);
+
+	return 0;
+}
+
+program_params_t parse_args ( int argc, char* argv[] ) {
+	program_params_t ret = { "127.0.0.1", "25575", "1234", "list" };
+	return ret;
+}
diff --git a/src/rcon.c b/src/rcon.c
new file mode 100644
index 0000000..a302d12
--- /dev/null
+++ b/src/rcon.c
@@ -0,0 +1,97 @@
+/*
+ * src/rcon.c
+ * (c) 2020 Jonas Gunz <himself@jonasgunz.de>
+ * License: 
+*/
+
+/*
+ * Length 	int 	Length of remainder of packet
+ * Request ID 	int 	Client-generated ID
+ * Type 	int 	3 for login, 2 to run a command, 0 for a multi-packet response
+ * Payload 	byte[] 	ASCII text
+ * 2-byte pad 	byte^2 	Two null bytes
+ *
+ * sizeof int: 4B
+ * Little Endian
+ *
+ * LOGIN	3
+ * LOGINFAIL	-1
+ * COMMAND	2
+ * RESPONSE	0
+ */
+
+#include "rcon.h"
+
+static char* rcon_errors[] = {
+	"No Error.",
+	"Undefined Error.",
+	"Login Denied.",
+	"Buffer size incorrect.",
+	"Malformed packet recieved."
+};
+
+static int rcon_write_int ( char* _buffer, int _len, int32_t _data ) {
+	if ( _len < 4 )
+		return -1;
+
+	for (int i = 0; i < 4; i++)
+		_buffer[i] = (char)(_data >> (i*8));
+
+	return 4;
+}
+
+static int rcon_read_int ( char* _buffer, int _len, int32_t* _out ) {
+	if ( _len < 4 )
+		return -1;
+
+	*_out = 0;
+	for (int i = 0; i < 4; i++)
+		*_out |= (int32_t)((int32_t)_buffer[i] << (i*8));
+
+	return 4;
+}
+
+int rcon_parse_packet ( rcon_packet_t* _packet, char* _buffer, uint32_t _len ) {
+	if ( _len < 14 )
+		return -1;
+
+	int32_t bytecount = 0;
+	
+	bytecount += rcon_read_int ( _buffer + bytecount, _len - bytecount, &_packet->length );
+	bytecount += rcon_read_int ( _buffer + bytecount, _len - bytecount, &_packet->id );
+	bytecount += rcon_read_int ( _buffer + bytecount, _len - bytecount, &_packet->type );
+
+	int32_t payload_len = _len - bytecount - 2;
+	_packet->payload_len = payload_len;
+	_packet->payload = malloc(payload_len);
+	memcpy ( _packet->payload, _buffer + bytecount, payload_len );
+	bytecount += payload_len;
+
+	bytecount += 2; // padding
+	//TODO check validity
+	return bytecount;
+}
+
+int rcon_construct_packet ( char* _buffer, uint32_t _len, rcon_packet_t* _packet ) {
+	if ( _len < RCON_SEND_PKGSIZE )
+		return -1; // Payload does not fit.
+
+	int32_t bytecount = 0;
+	_packet->length = _packet->payload_len + 10;
+
+	bytecount += rcon_write_int ( _buffer + bytecount, _len - bytecount, _packet->length );
+	bytecount += rcon_write_int ( _buffer + bytecount, _len - bytecount, _packet->id );
+	bytecount += rcon_write_int ( _buffer + bytecount, _len - bytecount, _packet->type );
+
+	memcpy ( _buffer + bytecount, _packet->payload, _packet->payload_len );
+	bytecount += _packet->payload_len;
+
+	memcpy ( _buffer + bytecount, "\0\0", 2);
+	bytecount += 2;
+
+	return bytecount;
+}
+
+char* rcon_strerror ( int _errno ) {
+	return _errno > 4 ? rcon_errors[1] : rcon_errors[_errno];
+}
diff --git a/src/rcon.h b/src/rcon.h
new file mode 100644
index 0000000..474fcdd
--- /dev/null
+++ b/src/rcon.h
@@ -0,0 +1,41 @@
+/*
+ * src/rcon.h
+ * (c) 2020 Jonas Gunz <himself@jonasgunz.de>
+ * License: 
+*/
+
+/*
+ * Length 	int 	Length of remainder of packet
+ * Request ID 	int 	Client-generated ID
+ * Type 	int 	3 for login, 2 to run a command, 0 for a multi-packet response
+ * Payload 	byte[] 	ASCII text
+ * 2-byte pad 	byte^2 	Two null bytes
+ *
+ * sizeof int: 4B
+ * */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define RCON_LOGIN	3
+#define RCON_LOLGINFAIL	-1
+#define RCON_COMMAND	2
+#define RCON_RESPONSE	0
+
+#define RCON_RECV_PKGSIZE 4110
+#define RCON_SEND_PKGSIZE 1460
+
+typedef struct rcon_packet_s {
+	int32_t length;
+	int32_t id;
+	int32_t type;
+	char*	payload;
+	uint32_t payload_len;
+} rcon_packet_t;
+
+int rcon_parse_packet ( rcon_packet_t* _packet, char* _buffer, uint32_t _len );
+
+int rcon_construct_packet ( char* _buffer, uint32_t _len, rcon_packet_t* _packet );
+
+char* rcon_strerror ( int _errno );