X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-eth-gw.git/blobdiff_plain/a5d61b569fe49e2ca9f8f38f0af5a0b147f2b806..5f30138c72a8c4893b03b63664e3b6b1ba82e8df:/utils/cegw/cegw.c

diff --git a/utils/cegw/cegw.c b/utils/cegw/cegw.c
index 275d659..4787f55 100644
--- a/utils/cegw/cegw.c
+++ b/utils/cegw/cegw.c
@@ -1,281 +1,241 @@
+/*
+ * Copyright: (c) 2012 Czech Technical University in Prague
+ *
+ * Authors:
+ *	Radek Matějka <radek.matejka@gmail.com>
+ *	Michal Sojka  <sojkam1@fel.cvut.cz>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+
 #include <stdio.h>
 #include <stdlib.h>
-#include <libgen.h>
 #include <string.h>
-#include <getopt.h>
-#include <errno.h>
 #include <sys/socket.h>
 #include <net/if.h>
-#include <libnetlink.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
 #include <arpa/inet.h>
 #include <linux/can.h>
-#include <linux/types.h>
+#include <limits.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
 #include "canethgw.h"
 
-/**
- * ToDo
- * [ ] refactor error messages
- * [ ] start/stop listening
- * [ ] remove routing job
- * [ ] recv netlink reponse
- * 
- */
+unsigned int cegw_errno = 0;
 
-#define CMD_STOP_LISTEN    1
-#define CMD_START_LISTEN   2
-#define CMD_ADD_RULE       4
+enum
+{
+	CEGW_ERR_UNKNOWN,
+	CEGW_ERR_COLON,
+	CEGW_ERR_UNEXLEN,
+	CEGW_ERR_ATON,
+	CEGW_ERR_PORT
+};
 
-enum {
-	IF_UNDEF,
-	IF_CAN,
-	IF_ETH_UDP
+char* cegw_errlist[] =
+{
+	[CEGW_ERR_UNKNOWN] = "",
+	[CEGW_ERR_COLON  ] = "expected ':' (<ip>:<port>)",
+	[CEGW_ERR_UNEXLEN] = "unexpected ip address length, please use dot notation"
+		             " (eg. 127.0.0.1)",
+	[CEGW_ERR_ATON   ] = "ip address mismatch",
+	[CEGW_ERR_PORT   ] = "port number"
 };
 
+static const char help_msg[] = "usage:\n"
+			       "	%s <can_if> <udp_listen_addr>:<port> <udp_dest_addr>:<port>\n"
+			       "		[list of additional udp recipients <addr:port>]\n"
+			       "example:\n"
+			       "	%s can0 192.168.0.1:10501 192.168.0.4:980 192.168.0.7:1160\n\n"
+			       "	Executing this command will set the gateway so that it will\n"
+			       "	listen for udp messages on 192.168.0.1:10501 and send them\n"
+			       "	to can0. Simultaneously, it will send all messages from can0\n"
+			       "	to 192.168.0.4:980 and 192.168.0.7:1160 via udp. The message is\n"
+			       "	therefore cloned. Notice that there can be any number\n"
+			       "	of udp recipients.\n";
+
+static void perr(char* s)
+{
+	if (s) {
+		if (cegw_errno == 0) {
+			fprintf(stderr, "error: %s\n", s);
+
+		} else {
+			fprintf(stderr, "error: %s, %s\n", s, cegw_errlist[cegw_errno]);
+		}
+		return;
+	}
+
+	fprintf(stderr, "error: %s\n", cegw_errlist[cegw_errno]);
+}
 
 /**
- * parses @in for eth address, valid input is 
- * e.g. udp@127.0.0.1:10502 or can@vcan0
+ * read_addrport - parses @in for eth address.
+ * Valid input is e.g. 127.0.0.1:10502. If parsing fails
+ * the cause is stored in cegw_errno.
  *
+ * @param[in]  in   string to search in
  * @param[out] addr ip address
  * @param[out] port transport layer port
- * @return 0 on success
+ * @return 0 on success, -1 otherwise
  */
-int read_addr_port( char* in, struct in_addr* addr, unsigned short* port )
+int read_addrport(char* in, struct in_addr* addr, unsigned short* port)
 {
 	char* delim = NULL;
-	char addrstr[16];
+	const int addrstr_len = 16;
+	char addrstr[addrstr_len];
 	int addrlen;
-	
-	if( (delim = strchr( in, ':' )) == NULL )
-	{
-		fprintf( stderr, "error: ':'\n" );
+
+	if ((delim = strchr(in, ':')) == NULL) {
+		cegw_errno = CEGW_ERR_COLON;
 		return -1;
 	}
 
 	/* get address */
 	addrlen = delim - in;
-	memcpy( addrstr, in, addrlen );
+	if (addrlen > addrstr_len) {
+		cegw_errno = CEGW_ERR_UNEXLEN;
+		return -1;
+	}
+
+	memcpy(addrstr, in, addrlen);
 	addrstr[addrlen] = '\0';
-	if( inet_aton( addrstr, addr ) == 0 )
-	{
-		fprintf( stderr, "error: aton\n" );
+	if (inet_aton(addrstr, addr) == 0) {
+		cegw_errno = CEGW_ERR_ATON;
 		return -1;
 	}
 
 	/* get port */
-	if( sscanf( delim, ":%hu", port ) != 1 ) /* todo: handle overflow */
-	{
-		fprintf( stderr, "error: port\n" );
+	/* ToDo: handle overflow */
+	if (sscanf(delim, ":%hu", port) != 1) {
+		cegw_errno = CEGW_ERR_PORT;
 		return -1;
 	}
 
 	return 0;
 }
 
-char* read_iftype( char* in, int* iftype )
+int main(int argc, char* argv[])
 {
-	char* ret = in+4;
-	
-	if( strncmp( "udp@", optarg, 4 ) == 0 )
-	{
-		*iftype = IF_ETH_UDP;
-		return ret;
-	}
-	else if( strncmp( "tcp@", optarg, 4 ) == 0 )
-	{
-		return NULL;
-	}
-	else if( strncmp( "can@", optarg, 4 ) == 0 )
+	int i;
+	int fd;
+	int tmpi;
+	int dstcnt;
+	unsigned short port;
+	int udp_sock, can_sock;
+	struct sockaddr_in udp_addr;
+	struct sockaddr_can can_addr;
+	struct sockaddr_in* dst = NULL;
+	struct cegw_ioctl* gwctl = NULL;
+
+	if (argc == 1)
 	{
-		*iftype = IF_CAN;
-		return ret;
+		printf(help_msg, argv[0], argv[0]);
+		return 0;
 	}
-	
-	return NULL;
-}
 
-int main( int argc, char* argv[] )
-{
-	int s;
-	int src_if = 0, dst_if = 0;
-	int can_ifidx = 0;
-	int tmp = 0;
-	int cmd = 0;
-	struct in_addr eth_addr;
-	unsigned short eth_port;
-	struct in_addr eth_listen_addr;
-	unsigned short eth_listen_port;
-	char* optstr;
-	char opt;
-	struct sockaddr_nl nladdr;
-	int err = 0;
-
-	struct option long_opt[] =
-	{
-		{ "start-listen", 1, NULL, 'l' },
-		{ "stop-listen" , 1, NULL, 'k' },
-		{ 0, 0, 0, 0 }
-	};
-	
-	struct {
-		struct nlmsghdr nh;
-		struct rtcanmsg rtcan;
-		char buf[600]; /* enough? */
-	} req;
-	
-	while( 1 )
-	{
-		opt = getopt_long( argc, argv, "As:d:", long_opt, NULL );
-		if( opt == -1 )
-			break;
+	if (argc < 4) {
+		perr("not enought arguments");
+		printf(help_msg, argv[0], argv[0]);
+		/* ToDo: print usage */
+		return -1;
+	}
 
-		switch( opt )
-		{
-			case 's':
-				cmd |= CMD_ADD_RULE;
-				if( (optstr = read_iftype( optarg, &src_if )) == NULL )
-				{
-					fprintf( stderr, "error: bad input format\n" );
-					goto syntax_error;
-					break;
-				}
-				
-				switch( src_if )
-				{
-					case IF_CAN:
-						can_ifidx = if_nametoindex( optstr );
-						break;
-					case IF_ETH_UDP:
-						read_addr_port( optstr, &eth_addr, &eth_port );
-						break;
-					default:
-						fprintf( stderr, "error: unrecognized interface" );
-						goto syntax_error;
-						break;
+	dstcnt = argc-3;
+	gwctl = (struct cegw_ioctl*)malloc(sizeof(*gwctl) + (dstcnt)*sizeof(struct sockaddr_in));
+
+	for (i=1; i<argc; i++) {
+		switch (i) {
+			case 1: /* can ifindex */
+				can_addr.can_family = AF_CAN;
+				tmpi = if_nametoindex(argv[i]);
+				if (tmpi == 0) {
+					perr("given can interface not found");
+					free(gwctl);
+					return -1;
 				}
+				can_addr.can_ifindex = tmpi;
 				break;
-			case 'd':
-				cmd |= CMD_ADD_RULE;
-				if( (optstr = read_iftype( optarg, &dst_if )) == NULL )
-				{
-					fprintf( stderr, "error: bad input format\n" );
-					goto syntax_error;
-					break;
-				}
-				
-				switch( dst_if )
-				{
-					case IF_CAN:
-						can_ifidx = if_nametoindex( optstr ); /*chk*/
-						break;
-					case IF_ETH_UDP:
-						read_addr_port( optstr, &eth_addr, &eth_port ); /*chk*/
-						break;
-					default:
-						fprintf( stderr, "error: unrecognized interface" );
-						break;
+			case 2: /* listen addr */
+				udp_addr.sin_family = AF_INET;
+				if (read_addrport(argv[i], &udp_addr.sin_addr, &port) != 0) {
+					perr("listening address mismatch");
+					free(gwctl);
+					return -1;
 				}
+				udp_addr.sin_port = htons(port);
 				break;
-			case 'l':
-				cmd |= CMD_START_LISTEN;
-				if( (optstr = read_iftype( optarg, &tmp )) == NULL )
-				{
-					fprintf( stderr, "error: -l bad input format\n" );
-					goto syntax_error;
-					break;
+			default: /* udp destination */
+				dst = &gwctl->udp_dst[i-3];
+				dst->sin_family = AF_INET;
+				if (read_addrport(argv[i], &dst->sin_addr, &port) != 0) {
+					perr("udp destination mismatch");
+					free(gwctl);
+					return -1;
 				}
-				
-				if( tmp != IF_ETH_UDP )
-				{
-					fprintf( stderr, "error: -l bad input format\n" );
-					goto syntax_error;
-					break;
-				}
-					
-				read_addr_port( optstr, &eth_listen_addr, &eth_listen_port ); /*chk*/
-			case 'k':
-				cmd |= CMD_STOP_LISTEN;
-				break;
-			case '?':
+				dst->sin_port = htons(port);
 				break;
-			default:
-				fprintf( stderr, "error: unknown option\n" );
-			break;
-		}				
+		}
 	}
 
-	/* 2. do check on arguments */
-	if( cmd & CMD_ADD_RULE )
-	{
-		if( (src_if == 0 || dst_if == 0) || (src_if == dst_if) )
-		{
-			fprintf( stderr, "error: source or destination not specified\n" );
-			return -1;
-		}
-	
-		if( src_if == dst_if )
-		{
-			fprintf( stderr, "error: source and destination same interface type\n" );
-		}
+	/* prepare udp socket */
+	udp_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (udp_sock == -1) {
+		fprintf(stderr, "error: udp socket(..) failed\n");
+		free(gwctl);
+		return -1;
 	}
-	
-	/* 3. prepare netlink message */
-	req.nh.nlmsg_len   = NLMSG_LENGTH( sizeof(struct rtcanmsg) );
-	req.nh.nlmsg_type  = RTM_NEWROUTE;
-	req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
-	req.nh.nlmsg_seq   = 0;
-	req.nh.nlmsg_pid   = 0; /* ? */
-	
-	req.rtcan.can_family = AF_CAN;
-	req.rtcan.flags = 0;
 
-	if( cmd & CMD_ADD_RULE )
-	{
-		req.rtcan.gwtype = (src_if == IF_CAN) ? CGW_TYPE_CAN_ETH_UDP : CGW_TYPE_ETH_CAN_UDP;
-		addattr_l( &req.nh, sizeof(req), CGW_CAN_IF, &can_ifidx, sizeof(can_ifidx) );
-		switch( req.rtcan.gwtype )
-		{
-			case CGW_TYPE_CAN_ETH_UDP:
-				addattr_l( &req.nh, sizeof(req), CGW_ETH_IP, &eth_addr, sizeof(eth_addr) );
-				addattr_l( &req.nh, sizeof(req), CGW_ETH_PORT, &eth_port, sizeof(eth_port) );
-				break;
-			case CGW_TYPE_ETH_CAN_UDP:
-				break;
-			default:
-				break;
-		}
+	if (bind(udp_sock, (struct sockaddr *)&udp_addr, sizeof(struct sockaddr_in)) != 0) {
+		fprintf(stderr, "error: udp bind(..) failed\n");
+		free(gwctl);
+		return -1;
 	}
-	
-	if( cmd & CMD_START_LISTEN )
-	{
-		req.rtcan.gwtype = CGW_TYPE_CONFIG;
-		addattr_l( &req.nh, sizeof(req), CGW_LISTEN_IP, &eth_listen_addr, sizeof(eth_listen_addr) );
-		addattr_l( &req.nh, sizeof(req), CGW_LISTEN_PORT, &eth_listen_port, sizeof(eth_listen_port) );
-		printf( "start listen: %x, %hu\n", eth_listen_addr, eth_listen_port );
+
+	/* prepare can socket */
+	can_sock = socket(PF_CAN, SOCK_RAW, CAN_RAW);
+	if (can_sock == -1) {
+		fprintf(stderr, "error: can socket(..) failed\n");
+		free(gwctl);
+		return -1;
 	}
-	
-	/* 4. send over netlink socket */
-	s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); /* chck */
-	
-	memset(&nladdr, 0, sizeof(nladdr));
-	nladdr.nl_family = AF_NETLINK;
-	nladdr.nl_pid    = 0;
-	nladdr.nl_groups = 0;
 
-	err = sendto( s, &req, req.nh.nlmsg_len, 0, 
-	              (struct sockaddr*)&nladdr, sizeof(nladdr));
-	if (err < 0)
-	{
-		perror( "netlink sendto" );
-		return err;
+	if (bind(can_sock, (struct sockaddr *)&can_addr, sizeof(struct sockaddr_can)) != 0) {
+		fprintf(stderr, "error: can bind(..) failed\n");
+		free(gwctl);
+		return -1;
+	}
+
+	/* send it to kernel gateway */
+	fd = open("/dev/cegw", O_RDONLY);
+	if (fd == -1) {
+		fprintf(stderr, "error: could not open device file\n");
+		free(gwctl);
+		return -1;
+	}
+
+	gwctl->can_sock = can_sock;
+	gwctl->udp_sock = udp_sock;
+	gwctl->udp_dstcnt = dstcnt;
+	gwctl->udp_addrlen = sizeof(struct sockaddr_in);
+
+	if (ioctl(fd, CEGW_IOCTL_START, gwctl) != 0) {
+		perror(NULL);
+		free(gwctl);
+		return -1;
+	}
+	printf("gateway successfully set and running\n");
+	free(gwctl);
+
+	/* sleep until someone kills me */
+	while (1) {
+		sleep(UINT_MAX);
 	}
-	
-	/* ack? */
-	
+
 	return 0;
-syntax_error:
-	return -1;
 }