+/*
+ * 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, ð_addr, ð_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, ð_addr, ð_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, ð_listen_addr, ð_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, ð_addr, sizeof(eth_addr) );
- addattr_l( &req.nh, sizeof(req), CGW_ETH_PORT, ð_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, ð_listen_addr, sizeof(eth_listen_addr) );
- addattr_l( &req.nh, sizeof(req), CGW_LISTEN_PORT, ð_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;
}
projects / can-eth-gw.git / blobdiff