| /* |
| * Copyright (c) 2009 Felix Obenhuber |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote |
| * products derived from this software without specific prior written |
| * permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * SocketCan sniffing API implementation for Linux platform |
| * By Felix Obenhuber <felix@obenhuber.de> |
| * |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include "pcap-int.h" |
| #include "pcap-can-linux.h" |
| |
| #ifdef NEED_STRERROR_H |
| #include "strerror.h" |
| #endif |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <sys/ioctl.h> |
| #include <sys/socket.h> |
| #include <net/if.h> |
| #include <arpa/inet.h> |
| |
| #include <linux/can.h> |
| #include <linux/can/raw.h> |
| |
| /* not yet defined anywhere */ |
| #ifndef PF_CAN |
| #define PF_CAN 29 |
| #endif |
| #ifndef AF_CAN |
| #define AF_CAN PF_CAN |
| #endif |
| |
| /* forward declaration */ |
| static int can_activate(pcap_t *); |
| static int can_read_linux(pcap_t *, int , pcap_handler , u_char *); |
| static int can_inject_linux(pcap_t *, const void *, size_t); |
| static int can_setfilter_linux(pcap_t *, struct bpf_program *); |
| static int can_setdirection_linux(pcap_t *, pcap_direction_t); |
| static int can_stats_linux(pcap_t *, struct pcap_stat *); |
| |
| /* |
| * Private data for capturing on Linux CANbus devices. |
| */ |
| struct pcap_can { |
| int ifindex; /* interface index of device we're bound to */ |
| }; |
| |
| int |
| can_findalldevs(pcap_if_t **devlistp, char *errbuf) |
| { |
| /* |
| * There are no platform-specific devices since each device |
| * exists as a regular network interface. |
| * |
| * XXX - true? |
| */ |
| return 0; |
| } |
| |
| pcap_t * |
| can_create(const char *device, char *ebuf, int *is_ours) |
| { |
| const char *cp; |
| char *cpend; |
| long devnum; |
| pcap_t* p; |
| |
| /* Does this look like a CANbus device? */ |
| cp = strrchr(device, '/'); |
| if (cp == NULL) |
| cp = device; |
| /* Does it begin with "can" or "vcan"? */ |
| if (strncmp(cp, "can", 3) == 0) { |
| /* Begins with "can" */ |
| cp += 3; /* skip past "can" */ |
| } else if (strncmp(cp, "vcan", 4) == 0) { |
| /* Begins with "vcan" */ |
| cp += 4; |
| } else { |
| /* Nope, doesn't begin with "can" or "vcan" */ |
| *is_ours = 0; |
| return NULL; |
| } |
| /* Yes - is "can" or "vcan" followed by a number from 0? */ |
| devnum = strtol(cp, &cpend, 10); |
| if (cpend == cp || *cpend != '\0') { |
| /* Not followed by a number. */ |
| *is_ours = 0; |
| return NULL; |
| } |
| if (devnum < 0) { |
| /* Followed by a non-valid number. */ |
| *is_ours = 0; |
| return NULL; |
| } |
| |
| /* OK, it's probably ours. */ |
| *is_ours = 1; |
| |
| p = pcap_create_common(device, ebuf, sizeof (struct pcap_can)); |
| if (p == NULL) |
| return (NULL); |
| |
| p->activate_op = can_activate; |
| return (p); |
| } |
| |
| |
| static int |
| can_activate(pcap_t* handle) |
| { |
| struct pcap_can *handlep = handle->priv; |
| struct sockaddr_can addr; |
| struct ifreq ifr; |
| |
| /* Initialize some components of the pcap structure. */ |
| handle->bufsize = 24; |
| handle->offset = 8; |
| handle->linktype = DLT_CAN_SOCKETCAN; |
| handle->read_op = can_read_linux; |
| handle->inject_op = can_inject_linux; |
| handle->setfilter_op = can_setfilter_linux; |
| handle->setdirection_op = can_setdirection_linux; |
| handle->set_datalink_op = NULL; |
| handle->getnonblock_op = pcap_getnonblock_fd; |
| handle->setnonblock_op = pcap_setnonblock_fd; |
| handle->stats_op = can_stats_linux; |
| |
| /* Create socket */ |
| handle->fd = socket(PF_CAN, SOCK_RAW, CAN_RAW); |
| if (handle->fd < 0) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s", |
| errno, strerror(errno)); |
| return PCAP_ERROR; |
| } |
| |
| /* get interface index */ |
| memset(&ifr, 0, sizeof(ifr)); |
| strncpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name)); |
| if (ioctl(handle->fd, SIOCGIFINDEX, &ifr) < 0) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, |
| "Unable to get interface index: %s", |
| pcap_strerror(errno)); |
| pcap_cleanup_live_common(handle); |
| return PCAP_ERROR; |
| } |
| handlep->ifindex = ifr.ifr_ifindex; |
| |
| /* allocate butter */ |
| handle->buffer = malloc(handle->bufsize); |
| if (!handle->buffer) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", |
| pcap_strerror(errno)); |
| pcap_cleanup_live_common(handle); |
| return PCAP_ERROR; |
| } |
| |
| /* Bind to the socket */ |
| addr.can_family = AF_CAN; |
| addr.can_ifindex = handlep->ifindex; |
| if( bind( handle->fd, (struct sockaddr*)&addr, sizeof(addr) ) < 0 ) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s", |
| handlep->ifindex, errno, strerror(errno)); |
| pcap_cleanup_live_common(handle); |
| return PCAP_ERROR; |
| } |
| |
| if (handle->opt.rfmon) |
| { |
| /* Monitor mode doesn't apply to CAN devices. */ |
| pcap_cleanup_live_common(handle); |
| return PCAP_ERROR_RFMON_NOTSUP; |
| } |
| |
| handle->selectable_fd = handle->fd; |
| return 0; |
| |
| } |
| |
| |
| static int |
| can_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) |
| { |
| struct msghdr msg; |
| struct pcap_pkthdr pkth; |
| struct iovec iv; |
| struct can_frame* cf; |
| |
| iv.iov_base = &handle->buffer[handle->offset]; |
| iv.iov_len = handle->snapshot; |
| |
| memset(&msg, 0, sizeof(msg)); |
| msg.msg_iov = &iv; |
| msg.msg_iovlen = 1; |
| msg.msg_control = handle->buffer; |
| msg.msg_controllen = handle->offset; |
| |
| do |
| { |
| pkth.caplen = recvmsg(handle->fd, &msg, 0); |
| if (handle->break_loop) |
| { |
| handle->break_loop = 0; |
| return -2; |
| } |
| } while ((pkth.caplen == -1) && (errno == EINTR)); |
| |
| if (pkth.caplen < 0) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s", |
| errno, strerror(errno)); |
| return -1; |
| } |
| |
| /* adjust capture len according to frame len */ |
| cf = (struct can_frame*)&handle->buffer[8]; |
| pkth.caplen -= 8 - cf->can_dlc; |
| pkth.len = pkth.caplen; |
| |
| cf->can_id = htonl( cf->can_id ); |
| |
| if( -1 == gettimeofday(&pkth.ts, NULL) ) |
| { |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get time of day %d:%s", |
| errno, strerror(errno)); |
| return -1; |
| } |
| |
| callback(user, &pkth, &handle->buffer[8]); |
| |
| return 1; |
| } |
| |
| |
| static int |
| can_inject_linux(pcap_t *handle, const void *buf, size_t size) |
| { |
| /* not yet implemented */ |
| snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " |
| "can devices"); |
| return (-1); |
| } |
| |
| |
| static int |
| can_stats_linux(pcap_t *handle, struct pcap_stat *stats) |
| { |
| /* not yet implemented */ |
| stats->ps_recv = 0; /* number of packets received */ |
| stats->ps_drop = 0; /* number of packets dropped */ |
| stats->ps_ifdrop = 0; /* drops by interface -- only supported on some platforms */ |
| return 0; |
| } |
| |
| |
| static int |
| can_setfilter_linux(pcap_t *p, struct bpf_program *fp) |
| { |
| /* not yet implemented */ |
| return 0; |
| } |
| |
| |
| static int |
| can_setdirection_linux(pcap_t *p, pcap_direction_t d) |
| { |
| /* no support for PCAP_D_OUT */ |
| if (d == PCAP_D_OUT) |
| { |
| snprintf(p->errbuf, sizeof(p->errbuf), |
| "Setting direction to PCAP_D_OUT is not supported on can"); |
| return -1; |
| } |
| |
| p->direction = d; |
| |
| return 0; |
| } |
| |
| |
| /* eof */ |