1 files changed, 264 insertions, 0 deletions
diff --git a/pcap-can-linux.c b/pcap-can-linux.c
new file mode 100644
index 0000000..fb8e232
--- /dev/null
+++ b/pcap-can-linux.c
@@ -0,0 +1,264 @@
+/*
+ * 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 *);
+
+pcap_t *
+can_create(const char *device, char *ebuf)
+{
+	pcap_t* p;
+
+	p = pcap_create_common(device, ebuf);
+	if (p == NULL)
+		return (NULL);
+
+	p->activate_op = can_activate;
+	return (p);
+}
+
+
+static int
+can_activate(pcap_t* handle)
+{
+	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;
+	}
+	handle->md.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 = handle->md.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",
+			handle->md.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;
+	}
+
+	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 */