]> rtime.felk.cvut.cz Git - can-eth-gw.git/blobdiff - utils/cegw/cegw.c
cegw cleanup and refactor, new test t7
[can-eth-gw.git] / utils / cegw / cegw.c
index 275d6592ff91864c9707ce0acf1787efa68b6c29..c0cb885313d6c8d6d7ffc098db923147f405bd9b 100644 (file)
 #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 <sys/types.h>
+#include <sys/stat.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_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_ATON   ] = "ip address mismatch",
+       [CEGW_ERR_PORT   ] = "port number"
 };
 
+static const char help_msg[] = "usage:\n\
+       %s <can_if> <udp_listen_addr>:<port> N x (<udp_dest_addr>:<port>)\n\
+example:\n\
+       %s can0 192.168.0.1:10501 192.168.0.4:980 192.168.0.7:1160\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. udp@127.0.0.1:10502 or can@vcan0.
  *
+ * @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];
        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 );
+       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 )
-       {
-               *iftype = IF_CAN;
-               return ret;
+       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 < 3) {
+               perr("not enought arguments");
+               printf(help_msg, argv[0], argv[0]);
+               /* ToDo: print usage */
+               return -1;
        }
-       
-       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;
-
-               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;
-                               }
-                               
-                               if( tmp != IF_ETH_UDP )
-                               {
-                                       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;
                                }
-                                       
-                               read_addr_port( optstr, &eth_listen_addr, &eth_listen_port ); /*chk*/
-                       case 'k':
-                               cmd |= CMD_STOP_LISTEN;
+                               dst->sin_port = htons(port);
                                break;
-                       case '?':
-                               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;
        }
-       
-       /* ack? */
-       
+
+       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 sucessfully set-up and running\n");
+       free(gwctl);
+
+       /* sleep until someone kills me */
+       while (1) {
+               sleep(UINT_MAX);
+       }
+
        return 0;
-syntax_error:
-       return -1;
 }