2 * Copyright (c) 2009 Felix Obenhuber
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
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30 * SocketCan sniffing API implementation for Linux platform
31 * By Felix Obenhuber <felix@obenhuber.de>
40 #include "pcap-can-linux.h"
42 #ifdef NEED_STRERROR_H
51 #include <sys/ioctl.h>
52 #include <sys/socket.h>
54 #include <arpa/inet.h>
56 #include <linux/can.h>
57 #include <linux/can/raw.h>
59 /* not yet defined anywhere */
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 *);
76 can_create(const char *device, char *ebuf)
80 p = pcap_create_common(device, ebuf);
84 p->activate_op = can_activate;
90 can_activate(pcap_t* handle)
92 struct sockaddr_can addr;
95 /* Initialize some components of the pcap structure. */
98 handle->linktype = DLT_CAN_SOCKETCAN;
99 handle->read_op = can_read_linux;
100 handle->inject_op = can_inject_linux;
101 handle->setfilter_op = can_setfilter_linux;
102 handle->setdirection_op = can_setdirection_linux;
103 handle->set_datalink_op = NULL;
104 handle->getnonblock_op = pcap_getnonblock_fd;
105 handle->setnonblock_op = pcap_setnonblock_fd;
106 handle->stats_op = can_stats_linux;
109 handle->fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
112 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
113 errno, strerror(errno));
117 /* get interface index */
118 memset(&ifr, 0, sizeof(ifr));
119 strncpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name));
120 if (ioctl(handle->fd, SIOCGIFINDEX, &ifr) < 0)
122 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
123 "Unable to get interface index: %s",
124 pcap_strerror(errno));
125 pcap_cleanup_live_common(handle);
128 handle->md.ifindex = ifr.ifr_ifindex;
130 /* allocate butter */
131 handle->buffer = malloc(handle->bufsize);
134 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
135 pcap_strerror(errno));
136 pcap_cleanup_live_common(handle);
140 /* Bind to the socket */
141 addr.can_family = AF_CAN;
142 addr.can_ifindex = handle->md.ifindex;
143 if( bind( handle->fd, (struct sockaddr*)&addr, sizeof(addr) ) < 0 )
145 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
146 handle->md.ifindex, errno, strerror(errno));
147 pcap_cleanup_live_common(handle);
151 if (handle->opt.rfmon)
153 /* Monitor mode doesn't apply to CAN devices. */
154 pcap_cleanup_live_common(handle);
158 handle->selectable_fd = handle->fd;
165 can_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
168 struct pcap_pkthdr pkth;
170 struct can_frame* cf;
172 iv.iov_base = &handle->buffer[handle->offset];
173 iv.iov_len = handle->snapshot;
175 memset(&msg, 0, sizeof(msg));
178 msg.msg_control = handle->buffer;
179 msg.msg_controllen = handle->offset;
183 pkth.caplen = recvmsg(handle->fd, &msg, 0);
184 if (handle->break_loop)
186 handle->break_loop = 0;
189 } while ((pkth.caplen == -1) && (errno == EINTR));
193 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
194 errno, strerror(errno));
198 /* adjust capture len according to frame len */
199 cf = (struct can_frame*)&handle->buffer[8];
200 pkth.caplen -= 8 - cf->can_dlc;
201 pkth.len = pkth.caplen;
203 cf->can_id = htonl( cf->can_id );
205 if( -1 == gettimeofday(&pkth.ts, NULL) )
207 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get time of day %d:%s",
208 errno, strerror(errno));
212 callback(user, &pkth, &handle->buffer[8]);
219 can_inject_linux(pcap_t *handle, const void *buf, size_t size)
221 /* not yet implemented */
222 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
229 can_stats_linux(pcap_t *handle, struct pcap_stat *stats)
231 /* not yet implemented */
232 stats->ps_recv = 0; /* number of packets received */
233 stats->ps_drop = 0; /* number of packets dropped */
234 stats->ps_ifdrop = 0; /* drops by interface -- only supported on some platforms */
240 can_setfilter_linux(pcap_t *p, struct bpf_program *fp)
242 /* not yet implemented */
248 can_setdirection_linux(pcap_t *p, pcap_direction_t d)
250 /* no support for PCAP_D_OUT */
253 snprintf(p->errbuf, sizeof(p->errbuf),
254 "Setting direction to PCAP_D_OUT is not supported on can");