]> rtime.felk.cvut.cz Git - can-eth-gw.git/blobdiff - utils/cegw/cegw.c
Understand -h option
[can-eth-gw.git] / utils / cegw / cegw.c
index efbe2c775bcc4e1dd711d6535199a1fa1a4a14fc..e513aec4db211dffe50051aadb0e19905e12da29 100644 (file)
+/*
+ * Copyright: (c) 2012 Czech Technical University in Prague
+ *
+ * Authors:
+ *     Radek Matějka <radek.matejka@gmail.com>
+ *     Michal Sojka  <sojkam1@fel.cvut.cz>
+ *
+ * Funded by: Volkswagen Group Research
+ *
+ * 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 <netdb.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 "canethgw.h"
-
-/**
- * ToDo
- * [ ] refactor error messages
- * [ ] start/stop listening
- * [ ] remove routing job
- * [ ] recv netlink reponse
- * 
- */
+#include <limits.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/can/raw.h>
+#include <linux/can/canethgw.h>
 
-#define CEGW_CMD_ADD     1
-#define CEGW_CMD_LIST    2
-#define CEGW_CMD_FLUSH   4
-#define CEGW_CMD_LISTEN  8
-
-enum
-{
-       IF_UNDEF,
-       IF_CAN,
-       IF_ETH_UDP
-};
+unsigned int cegw_errno = 0;
 
-struct cegw_data
-{
-       int content;
-       int src_if, dst_if;
-       int can_ifidx;
-       struct in_addr eth_addr;
-       unsigned short eth_port;
-       struct in_addr eth_listen_addr;
-       unsigned short eth_listen_port;
+enum {
+       CEGW_ERR_UNKNOWN,
+       CEGW_ERR_COLON,
+       CEGW_ERR_GETADDRI,
+       CEGW_ERR_FLTALCK,
+       CEGW_ERR_FLTPARSE,
+       CEGW_ERR_LAST
 };
 
-struct cegw_nlmsg 
-{
-       struct nlmsghdr nh;
-       struct rtcanmsg rtcan;
-       char buf[600]; /* enough? */
+char *cegw_errlist[] = {
+       [CEGW_ERR_COLON   ] = "expected ':' (<hostname>:<port>)",
+       [CEGW_ERR_GETADDRI] = "getaddrinfo failed",
+       [CEGW_ERR_FLTALCK ] = "filter alloc failed",
+       [CEGW_ERR_FLTPARSE] = "filter parsing failed"
 };
 
-unsigned int cegw_errno = 0;
-
-enum 
-{
-       CEGW_ERR_UNKNOWN,
-       CEGW_ERR_IF_UNSPEC,
-       CEGW_ERR_IF_SAME,
-       CEGW_ERR_IF_TYPE
+static const char help_msg[] = "usage:\n"
+                              "        %s <can_if>[,filter]* <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 more udp recipients.\n"
+                              "        The can filter is specified in the same way as in candump utility.\n";
+
+const struct addrinfo hints = {
+       .ai_family = AF_INET,
+       .ai_socktype = SOCK_DGRAM
 };
 
-char* cegw_errlist[] =
+static void perr(char *s)
 {
-       [ CEGW_ERR_UNKNOWN ]   = "unknown error",
-       [ CEGW_ERR_IF_UNSPEC ] = "source or destination not specified",
-       [ CEGW_ERR_IF_SAME   ] = "source and destination have same interface type",
-       [ CEGW_ERR_IF_TYPE    ] = "unknown interface type"
-};
+       if (s) {
+               if (cegw_errno == 0 || cegw_errno >= CEGW_ERR_LAST) {
+                       fprintf(stderr, "error: %s\n", s);
 
-static void perr( char* s )
-{
-       if( s )
-       {
-               fprintf( stderr, "error: %s; %s\n", s,
-               cegw_errlist[ cegw_errno ] );
+               } else {
+                       fprintf(stderr, "error: %s, %s\n", s, cegw_errlist[cegw_errno]);
+               }
                return;
        }
 
-       fprintf( stderr, "error: %s\n", cegw_errlist[ cegw_errno ] );
+       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.
+ * readsockaddr - 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. Please note that
+ * the function modifies content of arg.
  *
- * @param[out] addr ip address
- * @param[out] port transport layer port
- * @return 0 on success
+ * @param[in]  arg   hostname:port string
+ * @param[out] addr  filled sockaddr_in structure
+ * @return 0 on success, -1 otherwise
  */
-int read_addr_port( char* in, struct in_addr* addr, unsigned short* port )
+int readsockaddr(char *arg, struct sockaddr_in *addr)
 {
-       char* delim = NULL;
-       char addrstr[16];
-       int addrlen;
-       
-       if( (delim = strchr( in, ':' )) == NULL )
-       {
-               fprintf( stderr, "error: ':'\n" );
-               return -1;
-       }
+       int ret;
+       char *delim;
+       struct addrinfo *res;
+
+       delim = strchr(arg, ':');
 
-       /* get address */
-       addrlen = delim - in;
-       memcpy( addrstr, in, addrlen );
-       addrstr[addrlen] = '\0';
-       if( inet_aton( addrstr, addr ) == 0 )
-       {
-               fprintf( stderr, "error: aton\n" );
+       if (delim == NULL) {
+               cegw_errno = CEGW_ERR_COLON;
                return -1;
        }
 
-       /* get port */
-       if( sscanf( delim, ":%hu", port ) != 1 ) /* todo: handle overflow */
-       {
-               fprintf( stderr, "error: port\n" );
+       *delim = '\0';
+       delim++;
+
+       ret = getaddrinfo(arg, delim, &hints, &res);
+       if (ret != 0) {
+               fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ret));
+               cegw_errno = CEGW_ERR_GETADDRI;
                return -1;
        }
 
+       memcpy(addr, res->ai_addr, sizeof(*addr));
+
+       freeaddrinfo(res);
        return 0;
 }
 
 /**
- * Reads @in for iftype (e.g. "can@" or "udp@").
- *
- * @param[in] in string to search in
- * @param[out] iftype iftype detected
- * @return pointer to @in after iftype on success, NULL otherwise
+ * readfilter - reads can filter definition from nptr
  */
-char* read_iftype( char* in, int* iftype )
+int readfilter(char *nptr, struct can_filter **filter, int *out_numfilter, can_err_mask_t *err_mask)
 {
-       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;
+       char *ptr;
+       int numfilter;
+       struct can_filter *rfilter;
+
+       numfilter = 0;
+       ptr = nptr;
+       while (ptr) {
+               numfilter++;
+               ptr++; /* hop behind the ',' */
+               ptr = strchr(ptr, ','); /* exit condition */
        }
-       
-       errno = CEGW_ERR_IF_TYPE;
-       return NULL;
-}
 
-int read_if( char* in, int* iftype, struct cegw_data* d )
-{
-       char* optstr = NULL;
-
-       if( (optstr = read_iftype( in, iftype )) == NULL )
-       {
+       rfilter = malloc(numfilter * sizeof(*rfilter));
+       if (!rfilter) {
+               cegw_errno = CEGW_ERR_FLTALCK;
                return -1;
        }
 
-       switch( *iftype )
-       {
-               case IF_CAN:
-                       d->can_ifidx = if_nametoindex( optstr );
-                       break;
-               case IF_ETH_UDP:
-                       read_addr_port( optstr, &d->eth_addr, &d->eth_port );
-                       break;
-               default:
+       numfilter = 0;
+       *err_mask = 0;
+
+       while (nptr) {
+
+               ptr = nptr+1; /* hop behind the ',' */
+               nptr = strchr(ptr, ','); /* update exit condition */
+
+               if (sscanf(ptr, "%x:%x",
+                                       &rfilter[numfilter].can_id,
+                                       &rfilter[numfilter].can_mask) == 2) {
+                       rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
+                       numfilter++;
+               } else if (sscanf(ptr, "%x~%x",
+                                       &rfilter[numfilter].can_id,
+                                       &rfilter[numfilter].can_mask) == 2) {
+                       rfilter[numfilter].can_id |= CAN_INV_FILTER;
+                       rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
+                       numfilter++;
+               } else if (sscanf(ptr, "#%x", err_mask) != 1) {
+                       cegw_errno = CEGW_ERR_FLTPARSE;
+                       free(rfilter);
                        return -1;
-                       break;
+               }
        }
 
+       *filter = rfilter;
+       *out_numfilter = numfilter;
        return 0;
 }
 
-inline static int cegw_add( struct cegw_nlmsg* req, struct cegw_data* d )
+int main(int argc, char *argv[])
 {
-       req->nh.nlmsg_type  = RTM_NEWROUTE;
-       if( (d->src_if == 0 || d->dst_if == 0) )
-       {
-               cegw_errno = CEGW_ERR_IF_UNSPEC;
-               return -cegw_errno;
+       int i;
+       int fd;
+       int tmpi;
+       int dstcnt;
+       char *nptr;
+       int numfilter = 0;
+       int udp_sock, can_sock;
+       can_err_mask_t err_mask = 0;
+       struct sockaddr_in udp_addr;
+       struct sockaddr_can can_addr;
+       struct sockaddr_in *dst = NULL;
+       struct cegw_ioctl *gwctl = NULL;
+       struct can_filter *filter = NULL;
+
+       if (argc == 1 || (argc == 2 && strcmp(argv[1], "-h") == 0)) {
+               printf(help_msg, argv[0], argv[0]);
+               return 0;
        }
 
-       if( d->src_if == d->dst_if )
-       {
-               cegw_errno = CEGW_ERR_IF_SAME;
-               return -cegw_errno;
+       if (argc < 4) {
+               perr("not enough arguments");
+               printf(help_msg, argv[0], argv[0]);
+               /* ToDo: print usage */
+               return 1;
        }
 
-       req->rtcan.gwtype = (d->src_if == IF_CAN) ? CGW_TYPE_CAN_ETH_UDP : CGW_TYPE_ETH_CAN_UDP;
-       addattr_l( &req->nh, sizeof(*req), CGW_CAN_IF, &d->can_ifidx, sizeof(d->can_ifidx) );
-       switch( req->rtcan.gwtype )
-       {
-               case CGW_TYPE_CAN_ETH_UDP:
-                       addattr_l( &req->nh, sizeof(*req), CGW_ETH_IP, &d->eth_addr, sizeof(d->eth_addr) );
-                       addattr_l( &req->nh, sizeof(*req), CGW_ETH_PORT, &d->eth_port, sizeof(d->eth_port) );
-                       break;
-               case CGW_TYPE_ETH_CAN_UDP:
-                       break;
-               default:
-                       break;
-       }
+       dstcnt = argc-3;
+       gwctl = (struct cegw_ioctl*)malloc(sizeof(*gwctl) + (dstcnt)*sizeof(struct sockaddr_in));
 
-       return 0;
-}
-
-inline static int cegw_listen( struct cegw_nlmsg* req, struct cegw_data* d )
-{
-       req->nh.nlmsg_type  = RTM_NEWROUTE;
-       req->rtcan.gwtype = CGW_TYPE_CONFIG;
-       addattr_l( &req->nh, sizeof(req), CGW_LISTEN_IP, &d->eth_listen_addr, sizeof(d->eth_listen_addr) );
-       addattr_l( &req->nh, sizeof(req), CGW_LISTEN_PORT, &d->eth_listen_port, sizeof(d->eth_listen_port) );
-       printf( "start listen: %x, %hu\n", d->eth_listen_addr, d->eth_listen_port );
-
-       return 0;
-}
-
-inline static int cegw_list( struct cegw_nlmsg* req, struct cegw_data* d )
-{
-       return 0;
-}
-
-inline static int cegw_flush( struct cegw_nlmsg* req, struct cegw_data* d )
-{
-       req->nh.nlmsg_type  = RTM_DELROUTE;
-       req->rtcan.gwtype = CGW_TYPE_CAN_ETH_UDP;
-       req->rtcan.flags = CEGW_FLUSH; 
-       return 0;
-}
+       for (i=1; i<argc; i++) {
+               switch (i) {
+                       case 1: /* can ifindex */
+                               nptr = strchr(argv[i], ',');
+                               if (nptr) {
+                                       *nptr = '\0';
+                               }
 
-int main( int argc, char* argv[] )
-{
-       int s;
-       int tmp = 0;
-       int cmd = 0;
-       char* optstr;
-       char opt;
-       struct sockaddr_nl nladdr;
-       int err = 0;
-       struct cegw_nlmsg req;
-       struct cegw_data d;
-       char rxbuf[256];
-       int rsize = 0;
-       struct nlmsghdr* nlh;
-       struct nlmsgerr* rte;
-
-       memset( &d, 0, sizeof(d) );
-
-       struct option long_opt[] =
-       {
-               { "add"   , 0, NULL, 'A' },
-               { "flush" , 0, NULL, 'F' },
-               { "list"  , 0, NULL, 'L' },
-               { "listen", 1, NULL, 'l' },
-               { 0, 0, 0, 0 }
-       };
-
-       while( 1 )
-       {
-               opt = getopt_long( argc, argv, "As:d:", long_opt, NULL );
-               if( opt == -1 )
-                       break;
-
-               switch( opt )
-               {
-                       case 'A':
-                               cmd |= CEGW_CMD_ADD;
-                               break;
-                       case 'F':
-                               cmd |= CEGW_CMD_FLUSH;
-                               break;
-                       case 'L':
-                               cmd |= CEGW_CMD_FLUSH;
-                               break;
-                       case 'l':
-                               cmd |= CEGW_CMD_LISTEN;
-                               if( (optstr = read_iftype( optarg, &tmp )) == NULL )
-                               {
-                                       perr( "listen" );
-                                       return -1;
-                               }       
-                               if( tmp != IF_ETH_UDP )
-                               {
-                                       fprintf( stderr, "error: -l bad input format\n" );
-                                       return -1;
-                               }       
-                               read_addr_port( optstr, &d.eth_listen_addr, &d.eth_listen_port ); /*chk*/
-                               break;
-                       case 's':
-                               if( read_if( optarg, &d.src_if, &d ) != 0 )
-                               {
-                                       fprintf( stderr, "error: bad input format\n" );
-                                       goto syntax_error;
-                                       break;
+                               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':
-                               if( read_if( optarg, &d.dst_if, &d ) != 0 )
-                               {
-                                       fprintf( stderr, "error: bad input format\n" );
-                                       goto syntax_error;
-                                       break;
+                       case 2: /* listen addr */
+                               if (readsockaddr(argv[i], &udp_addr) != 0) {
+                                       perr("reading listening address failed");
+                                       free(gwctl);
+                                       return 1;
                                }
                                break;
-                       case '?':
-                               fprintf( stderr, "error: unknown option\n" );
-                               return -1;
-                               break;
-                       default:
-                               fprintf( stderr, "error: unknown option\n" );
-                               return -1;
+                       default: /* udp destination */
+                               dst = &gwctl->udp_dst[i-3];
+                               if (readsockaddr(argv[i], dst) != 0) {
+                                       perr("reading udp destination failed");
+                                       free(gwctl);
+                                       return 1;
+                               }
                                break;
-               }                               
+               }
        }
 
-       /* 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;
-
-       switch( cmd )
-       {
-               case 0:
-                       fprintf( stderr, "error: command not specified\n" );
-                       break;
-               case CEGW_CMD_ADD:
-                       if( cegw_add( &req, &d ) != 0 )
-                       {
-                               perr( "add" );
-                               return -1;
-                       }
-                       break;
-               case CEGW_CMD_FLUSH:
-                       cegw_flush( &req, &d );
-                       break;
-               case CEGW_CMD_LIST:
-                       cegw_list( &req, &d );
-                       break;
-               case CEGW_CMD_LISTEN:
-                       cegw_listen( &req, &d );
-                       break;
-               default:
-                       fprintf( stderr, "error: command mismatch\n" );
-                       break;
+       /* prepare udp socket */
+       udp_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+       if (udp_sock == -1) {
+               perror("udp socket()");
+               free(gwctl);
+               return 1;
        }
 
-       /* 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(udp_sock, (struct sockaddr *)&udp_addr, sizeof(struct sockaddr_in)) != 0) {
+               perror("bind(udp)");
+               free(gwctl);
+               return 1;
        }
-       
-       /* recv */
-       rsize = recv( s, &rxbuf, sizeof(rxbuf), 0 );
-       if( rsize < 0 )
-       {
-               fprintf( stderr, "error: recv\n" );
-               return -1;
+
+       /* prepare can socket */
+       can_sock = socket(PF_CAN, SOCK_RAW, CAN_RAW);
+       if (can_sock == -1) {
+               perror("can socket()");
+               free(gwctl);
+               return 1;
        }
-       nlh = (struct nlmsghdr*)rxbuf;
-       if( nlh->nlmsg_type != NLMSG_ERROR )
-       {
-               fprintf( stderr, "error: unexpected netlink answer\n" );
-               return -1;
+
+       if (bind(can_sock, (struct sockaddr *)&can_addr, sizeof(struct sockaddr_can)) != 0) {
+               perror("bind(can)");
+               free(gwctl);
+               return 1;
+       }
+
+       /* can filter */
+       if (nptr && (readfilter(nptr, &filter, &numfilter, &err_mask) != 0)) {
+               perr("can filter");
+               free(gwctl);
+               return 1;
        }
-       rte = (struct nlmsgerr*)NLMSG_DATA( nlh );
-       err = rte->error;
-       if( err < 0 )
-               fprintf( stderr, "error: netlink; %s\n", strerror(abs(err)) );
-       
+
+       if (err_mask)
+               setsockopt(can_sock, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
+                               &err_mask, sizeof(err_mask));
+
+       if (numfilter)
+               setsockopt(can_sock, SOL_CAN_RAW, CAN_RAW_FILTER,
+                               filter, numfilter * sizeof(struct can_filter));
+       free(filter);
+
+       /* send it to kernel gateway */
+       fd = open("/dev/canethgw", O_RDONLY);
+       if (fd == -1) {
+               perror("/dev/canethgw");
+               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("ioctl");
+               free(gwctl);
+               return 1;
+       }
+       printf("gateway successfully set and running\n");
+       free(gwctl);
+
+       /* sleep until someone kills me */
+       pause();
+
        return 0;
-syntax_error:
-       return -1;
 }
-