external/bsd/libpcap/dist/pcap-can-linux.c

   1 /*      $NetBSD: pcap-can-linux.c,v 1.3 2015/03/31 21:39:42 christos Exp $      */
   2
   3 /*
   4  * Copyright (c) 2009 Felix Obenhuber
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  * notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  * notice, this list of conditions and the following disclaimer in the
  15  * documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote
  17  * products derived from this software without specific prior written
  18  * permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * SocketCan sniffing API implementation for Linux platform
  33  * By Felix Obenhuber <felix@obenhuber.de>
  34  *
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __RCSID("$NetBSD: pcap-can-linux.c,v 1.3 2015/03/31 21:39:42 christos Exp $");
  39
  40 #ifdef HAVE_CONFIG_H
  41 #include "config.h"
  42 #endif
  43
  44 #include "pcap-int.h"
  45 #include "pcap-can-linux.h"
  46
  47 #ifdef NEED_STRERROR_H
  48 #include "strerror.h"
  49 #endif
  50
  51 #include <errno.h>
  52 #include <stdlib.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55 #include <string.h>
  56 #include <sys/ioctl.h>
  57 #include <sys/socket.h>
  58 #include <net/if.h>
  59 #include <arpa/inet.h>
  60
  61 #include <linux/can.h>
  62 #include <linux/can/raw.h>
  63
  64 /* not yet defined anywhere */
  65 #ifndef PF_CAN
  66 #define PF_CAN 29
  67 #endif
  68 #ifndef AF_CAN
  69 #define AF_CAN PF_CAN
  70 #endif
  71
  72 /* forward declaration */
  73 static int can_activate(pcap_t *);
  74 static int can_read_linux(pcap_t *, int , pcap_handler , u_char *);
  75 static int can_inject_linux(pcap_t *, const void *, size_t);
  76 static int can_setfilter_linux(pcap_t *, struct bpf_program *);
  77 static int can_setdirection_linux(pcap_t *, pcap_direction_t);
  78 static int can_stats_linux(pcap_t *, struct pcap_stat *);
  79
  80 /*
  81  * Private data for capturing on Linux CANbus devices.
  82  */
  83 struct pcap_can {
  84         int ifindex;            /* interface index of device we're bound to */
  85 };
  86
  87 int
  88 can_findalldevs(pcap_if_t **devlistp, char *errbuf)
  89 {
  90         /*
  91          * There are no platform-specific devices since each device
  92          * exists as a regular network interface.
  93          *
  94          * XXX - true?
  95          */
  96         return 0;
  97 }
  98
  99 pcap_t *
 100 can_create(const char *device, char *ebuf, int *is_ours)
 101 {
 102         const char *cp;
 103         char *cpend;
 104         long devnum;
 105         pcap_t* p;
 106
 107         /* Does this look like a CANbus device? */
 108         cp = strrchr(device, '/');
 109         if (cp == NULL)
 110                 cp = device;
 111         /* Does it begin with "can" or "vcan"? */
 112         if (strncmp(cp, "can", 3) == 0) {
 113                 /* Begins with "can" */
 114                 cp += 3;        /* skip past "can" */
 115         } else if (strncmp(cp, "vcan", 4) == 0) {
 116                 /* Begins with "vcan" */
 117                 cp += 4;
 118         } else {
 119                 /* Nope, doesn't begin with "can" or "vcan" */
 120                 *is_ours = 0;
 121                 return NULL;
 122         }
 123         /* Yes - is "can" or "vcan" followed by a number from 0? */
 124         devnum = strtol(cp, &cpend, 10);
 125         if (cpend == cp || *cpend != '\0') {
 126                 /* Not followed by a number. */
 127                 *is_ours = 0;
 128                 return NULL;
 129         }
 130         if (devnum < 0) {
 131                 /* Followed by a non-valid number. */
 132                 *is_ours = 0;
 133                 return NULL;
 134         }
 135
 136         /* OK, it's probably ours. */
 137         *is_ours = 1;
 138
 139         p = pcap_create_common(device, ebuf, sizeof (struct pcap_can));
 140         if (p == NULL)
 141                 return (NULL);
 142
 143         p->activate_op = can_activate;
 144         return (p);
 145 }
 146
 147
 148 static int
 149 can_activate(pcap_t* handle)
 150 {
 151         struct pcap_can *handlep = handle->priv;
 152         struct sockaddr_can addr;
 153         struct ifreq ifr;
 154
 155         /* Initialize some components of the pcap structure. */
 156         handle->bufsize = 24;
 157         handle->offset = 8;
 158         handle->linktype = DLT_CAN_SOCKETCAN;
 159         handle->read_op = can_read_linux;
 160         handle->inject_op = can_inject_linux;
 161         handle->setfilter_op = can_setfilter_linux;
 162         handle->setdirection_op = can_setdirection_linux;
 163         handle->set_datalink_op = NULL;
 164         handle->getnonblock_op = pcap_getnonblock_fd;
 165         handle->setnonblock_op = pcap_setnonblock_fd;
 166         handle->stats_op = can_stats_linux;
 167
 168         /* Create socket */
 169         handle->fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
 170         if (handle->fd < 0)
 171         {
 172                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
 173                         errno, strerror(errno));
 174                 return PCAP_ERROR;
 175         }
 176
 177         /* get interface index */
 178         memset(&ifr, 0, sizeof(ifr));
 179         strlcpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name));
 180         if (ioctl(handle->fd, SIOCGIFINDEX, &ifr) < 0)
 181         {
 182                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 183                                 "Unable to get interface index: %s",
 184                         pcap_strerror(errno));
 185                 pcap_cleanup_live_common(handle);
 186                 return PCAP_ERROR;
 187         }
 188         handlep->ifindex = ifr.ifr_ifindex;
 189
 190         /* allocate butter */
 191         handle->buffer = malloc(handle->bufsize);
 192         if (!handle->buffer)
 193         {
 194                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 195                         pcap_strerror(errno));
 196                 pcap_cleanup_live_common(handle);
 197                 return PCAP_ERROR;
 198         }
 199
 200         /* Bind to the socket */
 201         addr.can_family = AF_CAN;
 202         addr.can_ifindex = handlep->ifindex;
 203         if( bind( handle->fd, (struct sockaddr*)&addr, sizeof(addr) ) < 0  )
 204         {
 205                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
 206                         handlep->ifindex, errno, strerror(errno));
 207                 pcap_cleanup_live_common(handle);
 208                 return PCAP_ERROR;
 209         }
 210
 211         if (handle->opt.rfmon)
 212         {
 213                 /* Monitor mode doesn't apply to CAN devices. */
 214                 pcap_cleanup_live_common(handle);
 215                 return PCAP_ERROR_RFMON_NOTSUP;
 216         }
 217
 218         handle->selectable_fd = handle->fd;
 219         return 0;
 220
 221 }
 222
 223
 224 static int
 225 can_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 226 {
 227         struct msghdr msg;
 228         struct pcap_pkthdr pkth;
 229         struct iovec iv;
 230         struct can_frame* cf;
 231
 232         iv.iov_base = &handle->buffer[handle->offset];
 233         iv.iov_len = handle->snapshot;
 234
 235         memset(&msg, 0, sizeof(msg));
 236         msg.msg_iov = &iv;
 237         msg.msg_iovlen = 1;
 238         msg.msg_control = handle->buffer;
 239         msg.msg_controllen = handle->offset;
 240
 241         do
 242         {
 243                 pkth.caplen = recvmsg(handle->fd, &msg, 0);
 244                 if (handle->break_loop)
 245                 {
 246                         handle->break_loop = 0;
 247                         return -2;
 248                 }
 249         } while ((pkth.caplen == -1) && (errno == EINTR));
 250
 251         if (pkth.caplen == -1)
 252         {
 253                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
 254                         errno, strerror(errno));
 255                 return -1;
 256         }
 257
 258         /* adjust capture len according to frame len */
 259         cf = (struct can_frame*)&handle->buffer[8];
 260         pkth.caplen -= 8 - cf->can_dlc;
 261         pkth.len = pkth.caplen;
 262
 263         cf->can_id = htonl( cf->can_id );
 264
 265         if( -1 == gettimeofday(&pkth.ts, NULL) )
 266         {
 267                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get time of day %d:%s",
 268                         errno, strerror(errno));
 269                 return -1;
 270         }
 271
 272         callback(user, &pkth, &handle->buffer[8]);
 273
 274         return 1;
 275 }
 276
 277
 278 static int
 279 can_inject_linux(pcap_t *handle, const void *buf, size_t size)
 280 {
 281         /* not yet implemented */
 282         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 283                 "can devices");
 284         return (-1);
 285 }
 286
 287
 288 static int
 289 can_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 290 {
 291         /* not yet implemented */
 292         stats->ps_recv = 0;                      /* number of packets received */
 293         stats->ps_drop = 0;                      /* number of packets dropped */
 294         stats->ps_ifdrop = 0;            /* drops by interface -- only supported on some platforms */
 295         return 0;
 296 }
 297
 298
 299 static int
 300 can_setfilter_linux(pcap_t *p, struct bpf_program *fp)
 301 {
 302         /* not yet implemented */
 303         return 0;
 304 }
 305
 306
 307 static int
 308 can_setdirection_linux(pcap_t *p, pcap_direction_t d)
 309 {
 310         /* no support for PCAP_D_OUT */
 311         if (d == PCAP_D_OUT)
 312         {
 313                 snprintf(p->errbuf, sizeof(p->errbuf),
 314                         "Setting direction to PCAP_D_OUT is not supported on can");
 315                 return -1;
 316         }
 317
 318         p->direction = d;
 319
 320         return 0;
 321 }
 322
 323
 324 /* eof */