JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2009 Felix Obenhuber |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. The name of the author may not be used to endorse or promote |
| 15 | * products derived from this software without specific prior written |
| 16 | * permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | * SocketCan sniffing API implementation for Linux platform |
| 31 | * By Felix Obenhuber <felix@obenhuber.de> |
| 32 | * |
| 33 | */ |
| 34 | |
| 35 | #ifdef HAVE_CONFIG_H |
| 36 | #include "config.h" |
| 37 | #endif |
| 38 | |
| 39 | #include "pcap-int.h" |
| 40 | #include "pcap-can-linux.h" |
| 41 | |
| 42 | #ifdef NEED_STRERROR_H |
| 43 | #include "strerror.h" |
| 44 | #endif |
| 45 | |
| 46 | #include <errno.h> |
| 47 | #include <stdlib.h> |
| 48 | #include <unistd.h> |
| 49 | #include <fcntl.h> |
| 50 | #include <string.h> |
| 51 | #include <sys/ioctl.h> |
| 52 | #include <sys/socket.h> |
| 53 | #include <net/if.h> |
| 54 | #include <arpa/inet.h> |
| 55 | |
| 56 | #include <linux/can.h> |
| 57 | #include <linux/can/raw.h> |
| 58 | |
| 59 | /* not yet defined anywhere */ |
| 60 | #ifndef PF_CAN |
| 61 | #define PF_CAN 29 |
| 62 | #endif |
| 63 | #ifndef AF_CAN |
| 64 | #define AF_CAN PF_CAN |
| 65 | #endif |
| 66 | |
| 67 | /* forward declaration */ |
| 68 | static int can_activate(pcap_t *); |
| 69 | static int can_read_linux(pcap_t *, int , pcap_handler , u_char *); |
| 70 | static int can_inject_linux(pcap_t *, const void *, size_t); |
| 71 | static int can_setfilter_linux(pcap_t *, struct bpf_program *); |
| 72 | static int can_setdirection_linux(pcap_t *, pcap_direction_t); |
| 73 | static int can_stats_linux(pcap_t *, struct pcap_stat *); |
| 74 | |
| 75 | /* |
| 76 | * Private data for capturing on Linux CANbus devices. |
| 77 | */ |
| 78 | struct pcap_can { |
| 79 | int ifindex; /* interface index of device we're bound to */ |
| 80 | }; |
| 81 | |
| 82 | int |
| 83 | can_findalldevs(pcap_if_t **devlistp, char *errbuf) |
| 84 | { |
| 85 | /* |
| 86 | * There are no platform-specific devices since each device |
| 87 | * exists as a regular network interface. |
| 88 | * |
| 89 | * XXX - true? |
| 90 | */ |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | pcap_t * |
| 95 | can_create(const char *device, char *ebuf, int *is_ours) |
| 96 | { |
| 97 | const char *cp; |
| 98 | char *cpend; |
| 99 | long devnum; |
| 100 | pcap_t* p; |
| 101 | |
| 102 | /* Does this look like a CANbus device? */ |
| 103 | cp = strrchr(device, '/'); |
| 104 | if (cp == NULL) |
| 105 | cp = device; |
| 106 | /* Does it begin with "can" or "vcan"? */ |
| 107 | if (strncmp(cp, "can", 3) == 0) { |
| 108 | /* Begins with "can" */ |
| 109 | cp += 3; /* skip past "can" */ |
| 110 | } else if (strncmp(cp, "vcan", 4) == 0) { |
| 111 | /* Begins with "vcan" */ |
| 112 | cp += 4; |
| 113 | } else { |
| 114 | /* Nope, doesn't begin with "can" or "vcan" */ |
| 115 | *is_ours = 0; |
| 116 | return NULL; |
| 117 | } |
| 118 | /* Yes - is "can" or "vcan" followed by a number from 0? */ |
| 119 | devnum = strtol(cp, &cpend, 10); |
| 120 | if (cpend == cp || *cpend != '\0') { |
| 121 | /* Not followed by a number. */ |
| 122 | *is_ours = 0; |
| 123 | return NULL; |
| 124 | } |
| 125 | if (devnum < 0) { |
| 126 | /* Followed by a non-valid number. */ |
| 127 | *is_ours = 0; |
| 128 | return NULL; |
| 129 | } |
| 130 | |
| 131 | /* OK, it's probably ours. */ |
| 132 | *is_ours = 1; |
| 133 | |
| 134 | p = pcap_create_common(device, ebuf, sizeof (struct pcap_can)); |
| 135 | if (p == NULL) |
| 136 | return (NULL); |
| 137 | |
| 138 | p->activate_op = can_activate; |
| 139 | return (p); |
| 140 | } |
| 141 | |
| 142 | |
| 143 | static int |
| 144 | can_activate(pcap_t* handle) |
| 145 | { |
| 146 | struct pcap_can *handlep = handle->priv; |
| 147 | struct sockaddr_can addr; |
| 148 | struct ifreq ifr; |
| 149 | |
| 150 | /* Initialize some components of the pcap structure. */ |
| 151 | handle->bufsize = 24; |
| 152 | handle->offset = 8; |
| 153 | handle->linktype = DLT_CAN_SOCKETCAN; |
| 154 | handle->read_op = can_read_linux; |
| 155 | handle->inject_op = can_inject_linux; |
| 156 | handle->setfilter_op = can_setfilter_linux; |
| 157 | handle->setdirection_op = can_setdirection_linux; |
| 158 | handle->set_datalink_op = NULL; |
| 159 | handle->getnonblock_op = pcap_getnonblock_fd; |
| 160 | handle->setnonblock_op = pcap_setnonblock_fd; |
| 161 | handle->stats_op = can_stats_linux; |
| 162 | |
| 163 | /* Create socket */ |
| 164 | handle->fd = socket(PF_CAN, SOCK_RAW, CAN_RAW); |
| 165 | if (handle->fd < 0) |
| 166 | { |
| 167 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s", |
| 168 | errno, strerror(errno)); |
| 169 | return PCAP_ERROR; |
| 170 | } |
| 171 | |
| 172 | /* get interface index */ |
| 173 | memset(&ifr, 0, sizeof(ifr)); |
| 174 | strncpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name)); |
| 175 | if (ioctl(handle->fd, SIOCGIFINDEX, &ifr) < 0) |
| 176 | { |
| 177 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
| 178 | "Unable to get interface index: %s", |
| 179 | pcap_strerror(errno)); |
| 180 | pcap_cleanup_live_common(handle); |
| 181 | return PCAP_ERROR; |
| 182 | } |
| 183 | handlep->ifindex = ifr.ifr_ifindex; |
| 184 | |
| 185 | /* allocate butter */ |
| 186 | handle->buffer = malloc(handle->bufsize); |
| 187 | if (!handle->buffer) |
| 188 | { |
| 189 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", |
| 190 | pcap_strerror(errno)); |
| 191 | pcap_cleanup_live_common(handle); |
| 192 | return PCAP_ERROR; |
| 193 | } |
| 194 | |
| 195 | /* Bind to the socket */ |
| 196 | addr.can_family = AF_CAN; |
| 197 | addr.can_ifindex = handlep->ifindex; |
| 198 | if( bind( handle->fd, (struct sockaddr*)&addr, sizeof(addr) ) < 0 ) |
| 199 | { |
| 200 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s", |
| 201 | handlep->ifindex, errno, strerror(errno)); |
| 202 | pcap_cleanup_live_common(handle); |
| 203 | return PCAP_ERROR; |
| 204 | } |
| 205 | |
| 206 | if (handle->opt.rfmon) |
| 207 | { |
| 208 | /* Monitor mode doesn't apply to CAN devices. */ |
| 209 | pcap_cleanup_live_common(handle); |
| 210 | return PCAP_ERROR_RFMON_NOTSUP; |
| 211 | } |
| 212 | |
| 213 | handle->selectable_fd = handle->fd; |
| 214 | return 0; |
| 215 | |
| 216 | } |
| 217 | |
| 218 | |
| 219 | static int |
| 220 | can_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) |
| 221 | { |
| 222 | struct msghdr msg; |
| 223 | struct pcap_pkthdr pkth; |
| 224 | struct iovec iv; |
| 225 | struct can_frame* cf; |
| 226 | |
| 227 | iv.iov_base = &handle->buffer[handle->offset]; |
| 228 | iv.iov_len = handle->snapshot; |
| 229 | |
| 230 | memset(&msg, 0, sizeof(msg)); |
| 231 | msg.msg_iov = &iv; |
| 232 | msg.msg_iovlen = 1; |
| 233 | msg.msg_control = handle->buffer; |
| 234 | msg.msg_controllen = handle->offset; |
| 235 | |
| 236 | do |
| 237 | { |
| 238 | pkth.caplen = recvmsg(handle->fd, &msg, 0); |
| 239 | if (handle->break_loop) |
| 240 | { |
| 241 | handle->break_loop = 0; |
| 242 | return -2; |
| 243 | } |
| 244 | } while ((pkth.caplen == -1) && (errno == EINTR)); |
| 245 | |
| 246 | if (pkth.caplen < 0) |
| 247 | { |
| 248 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s", |
| 249 | errno, strerror(errno)); |
| 250 | return -1; |
| 251 | } |
| 252 | |
| 253 | /* adjust capture len according to frame len */ |
| 254 | cf = (struct can_frame*)&handle->buffer[8]; |
| 255 | pkth.caplen -= 8 - cf->can_dlc; |
| 256 | pkth.len = pkth.caplen; |
| 257 | |
| 258 | cf->can_id = htonl( cf->can_id ); |
| 259 | |
| 260 | if( -1 == gettimeofday(&pkth.ts, NULL) ) |
| 261 | { |
| 262 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get time of day %d:%s", |
| 263 | errno, strerror(errno)); |
| 264 | return -1; |
| 265 | } |
| 266 | |
| 267 | callback(user, &pkth, &handle->buffer[8]); |
| 268 | |
| 269 | return 1; |
| 270 | } |
| 271 | |
| 272 | |
| 273 | static int |
| 274 | can_inject_linux(pcap_t *handle, const void *buf, size_t size) |
| 275 | { |
| 276 | /* not yet implemented */ |
| 277 | snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " |
| 278 | "can devices"); |
| 279 | return (-1); |
| 280 | } |
| 281 | |
| 282 | |
| 283 | static int |
| 284 | can_stats_linux(pcap_t *handle, struct pcap_stat *stats) |
| 285 | { |
| 286 | /* not yet implemented */ |
| 287 | stats->ps_recv = 0; /* number of packets received */ |
| 288 | stats->ps_drop = 0; /* number of packets dropped */ |
| 289 | stats->ps_ifdrop = 0; /* drops by interface -- only supported on some platforms */ |
| 290 | return 0; |
| 291 | } |
| 292 | |
| 293 | |
| 294 | static int |
| 295 | can_setfilter_linux(pcap_t *p, struct bpf_program *fp) |
| 296 | { |
| 297 | /* not yet implemented */ |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | |
| 302 | static int |
| 303 | can_setdirection_linux(pcap_t *p, pcap_direction_t d) |
| 304 | { |
| 305 | /* no support for PCAP_D_OUT */ |
| 306 | if (d == PCAP_D_OUT) |
| 307 | { |
| 308 | snprintf(p->errbuf, sizeof(p->errbuf), |
| 309 | "Setting direction to PCAP_D_OUT is not supported on can"); |
| 310 | return -1; |
| 311 | } |
| 312 | |
| 313 | p->direction = d; |
| 314 | |
| 315 | return 0; |
| 316 | } |
| 317 | |
| 318 | |
| 319 | /* eof */ |