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/*
* 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.
*
* Sockettrace sniffing API implementation for Linux platform
* By Felix Obenhuber <felix@obenhuber.de>
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <libusb-1.0/libusb.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include "pcap-int.h"
#include "pcap-canusb-linux.h"
#define CANUSB_IFACE "canusb"
#define CANUSB_VID 0x0403
#define CANUSB_PID 0x8990
#define USE_THREAD 1
#if USE_THREAD == 0
#include <signal.h>
#endif
/* forward declaration */
static int canusb_activate(pcap_t *);
static int canusb_read_linux(pcap_t *, int , pcap_handler , u_char *);
static int canusb_inject_linux(pcap_t *, const void *, size_t);
static int canusb_setfilter_linux(pcap_t *, struct bpf_program *);
static int canusb_setdirection_linux(pcap_t *, pcap_direction_t);
static int canusb_stats_linux(pcap_t *, struct pcap_stat *);
struct CAN_Msg
{
uint32_t timestamp;
uint32_t id;
uint32_t length;
uint8_t data[8];
};
/*
* Private data for capturing on Linux CANbus USB devices.
*/
struct pcap_canusb {
libusb_context *ctx;
libusb_device_handle *dev;
pthread_t worker;
int rdpipe, wrpipe;
volatile int loop;
};
int canusb_findalldevs(pcap_if_t **alldevsp, char *err_str)
{
libusb_context *fdctx;
libusb_device** devs;
unsigned char sernum[65];
int cnt, i;
if (libusb_init(&fdctx) != 0) {
/*
* XXX - if this doesn't just mean "no USB file system mounted",
* perhaps we should report a real error rather than just
* saying "no CANUSB devices".
*/
return 0;
}
cnt = libusb_get_device_list(fdctx,&devs);
for(i=0;i<cnt;i++)
{
int ret;
/* Check if this device is interesting. */
struct libusb_device_descriptor desc;
libusb_device_handle *dh;
libusb_get_device_descriptor(devs[i],&desc);
if ((desc.idVendor != CANUSB_VID) || (desc.idProduct != CANUSB_PID))
continue; /* It is not, check next device */
/* It is! */
dh = NULL;
if ((ret = libusb_open(devs[i],&dh)) == 0)
{
char dev_name[30];
char dev_descr[50];
int n = libusb_get_string_descriptor_ascii(dh,desc.iSerialNumber,sernum,64);
sernum[n] = 0;
pcap_snprintf(dev_name, 30, CANUSB_IFACE"%s", sernum);
pcap_snprintf(dev_descr, 50, "CanUSB [%s]", sernum);
libusb_close(dh);
if (pcap_add_if(alldevsp, dev_name, 0, dev_descr, err_str) < 0)
{
libusb_free_device_list(devs,1);
libusb_exit(fdctx);
return -1;
}
}
}
libusb_free_device_list(devs,1);
libusb_exit(fdctx);
return 0;
}
static libusb_device_handle* canusb_opendevice(struct libusb_context *ctx, char* devserial)
{
libusb_device** devs;
unsigned char serial[65];
int cnt,i,n;
cnt = libusb_get_device_list(ctx,&devs);
for(i=0;i<cnt;i++)
{
/* Check if this device is interesting. */
struct libusb_device_descriptor desc;
libusb_device_handle *dh;
libusb_get_device_descriptor(devs[i],&desc);
if ((desc.idVendor != CANUSB_VID) || (desc.idProduct != CANUSB_PID))
continue;
/* Found one! */
dh = NULL;
if (libusb_open(devs[i],&dh) != 0) continue;
n = libusb_get_string_descriptor_ascii(dh,desc.iSerialNumber,serial,64);
serial[n] = 0;
if ((devserial) && (strcmp((char *)serial,devserial) != 0))
{
libusb_close(dh);
continue;
}
if ((libusb_kernel_driver_active(dh,0)) && (libusb_detach_kernel_driver(dh,0) != 0))
{
libusb_close(dh);
continue;
}
if (libusb_set_configuration(dh,1) != 0)
{
libusb_close(dh);
continue;
}
if (libusb_claim_interface(dh,0) != 0)
{
libusb_close(dh);
continue;
}
/* Fount it! */
libusb_free_device_list(devs,1);
return dh;
}
libusb_free_device_list(devs,1);
return NULL;
}
pcap_t *
canusb_create(const char *device, char *ebuf, int *is_ours)
{
const char *cp;
char *cpend;
long devnum;
pcap_t* p;
struct pcap_canusb *canusb;
/* Does this look like a DAG device? */
cp = strrchr(device, '/');
if (cp == NULL)
cp = device;
/* Does it begin with "canusb"? */
if (strncmp(cp, "canusb", 6) != 0) {
/* Nope, doesn't begin with "canusb" */
*is_ours = 0;
return NULL;
}
/* Yes - is "canusb" followed by a number? */
cp += 6;
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(ebuf, sizeof (struct pcap_canusb));
if (p == NULL)
return (NULL);
canusb = p->priv;
canusb->ctx = NULL;
canusb->dev = NULL;
canusb->rdpipe = -1;
canusb->wrpipe = -1;
p->activate_op = canusb_activate;
return (p);
}
static void* canusb_capture_thread(void *arg)
{
struct pcap_canusb *canusb = arg;
int i;
struct
{
uint8_t rxsz, txsz;
} status;
fcntl(canusb->wrpipe, F_SETFL, O_NONBLOCK);
while(canusb->loop)
{
int sz;
struct CAN_Msg msg;
libusb_interrupt_transfer(canusb->dev, 0x81, (unsigned char*)&status, sizeof(status), &sz, 100);
/* HACK!!!!! -> drop buffered data, read new one by reading twice. */
libusb_interrupt_transfer(canusb->dev, 0x81, (unsigned char*)&status, sizeof(status), &sz, 100);
for(i = 0; i<status.rxsz; i++)
{
libusb_bulk_transfer(canusb->dev, 0x85, (unsigned char*)&msg, sizeof(msg), &sz, 100);
if(write(canusb->wrpipe, &msg, sizeof(msg)) < 0)
fprintf(stderr,"write() error: %s\n", strerror(errno));
}
}
return NULL;
}
static int canusb_startcapture(struct pcap_canusb* this)
{
int pipefd[2];
if (pipe(pipefd) == -1)
return -1;
this->rdpipe = pipefd[0];
this->wrpipe = pipefd[1];
this->loop = 1;
pthread_create(&this->worker, NULL, canusb_capture_thread, this);
return this->rdpipe;
}
static void canusb_clearbufs(struct pcap_canusb* this)
{
unsigned char cmd[16];
int al;
cmd[0] = 1; /* Empty incoming buffer */
cmd[1] = 1; /* Empty outgoing buffer */
cmd[3] = 0; /* Not a write to serial number */
memset(&cmd[4],0,16-4);
libusb_interrupt_transfer(this->dev, 0x1,cmd,16,&al,100);
}
static void canusb_close(pcap_t* handle)
{
struct pcap_canusb *canusb = handle->priv;
canusb->loop = 0;
pthread_join(canusb->worker, NULL);
if (canusb->dev)
{
libusb_close(canusb->dev);
canusb->dev = NULL;
}
if (canusb->ctx)
{
libusb_exit(canusb->ctx);
canusb->ctx = NULL;
}
}
static int canusb_activate(pcap_t* handle)
{
struct pcap_canusb *canusb = handle->priv;
char *serial;
if (libusb_init(&canusb->ctx) != 0) {
/*
* XXX - what causes this to fail?
*/
pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "libusb_init() failed");
return PCAP_ERROR;
}
handle->read_op = canusb_read_linux;
handle->inject_op = canusb_inject_linux;
handle->setfilter_op = canusb_setfilter_linux;
handle->setdirection_op = canusb_setdirection_linux;
handle->getnonblock_op = pcap_getnonblock_fd;
handle->setnonblock_op = pcap_setnonblock_fd;
handle->stats_op = canusb_stats_linux;
handle->cleanup_op = canusb_close;
/* Initialize some components of the pcap structure. */
handle->bufsize = 32;
handle->offset = 8;
handle->linktype = DLT_CAN_SOCKETCAN;
handle->set_datalink_op = NULL;
serial = handle->opt.device + strlen(CANUSB_IFACE);
canusb->dev = canusb_opendevice(canusb->ctx, serial);
if (!canusb->dev)
{
libusb_exit(canusb->ctx);
pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't open USB Device");
return PCAP_ERROR;
}
canusb_clearbufs(canusb);
handle->fd = canusb_startcapture(canusb);
handle->selectable_fd = handle->fd;
return 0;
}
static int
canusb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
{
static struct timeval firstpacket = { -1, -1};
int i = 0;
struct CAN_Msg msg;
struct pcap_pkthdr pkth;
while(i < max_packets)
{
int n;
usleep(10 * 1000);
n = read(handle->fd, &msg, sizeof(msg));
if (n <= 0)
break;
pkth.caplen = pkth.len = n;
pkth.caplen -= 4;
pkth.caplen -= 8 - msg.length;
if ((firstpacket.tv_sec == -1) && (firstpacket.tv_usec == -1))
gettimeofday(&firstpacket, NULL);
pkth.ts.tv_usec = firstpacket.tv_usec + (msg.timestamp % 100) * 10000;
pkth.ts.tv_sec = firstpacket.tv_usec + (msg.timestamp / 100);
if (pkth.ts.tv_usec > 1000000)
{
pkth.ts.tv_usec -= 1000000;
pkth.ts.tv_sec++;
}
callback(user, &pkth, (void*)&msg.id);
i++;
}
return i;
}
static int
canusb_inject_linux(pcap_t *handle, const void *buf, size_t size)
{
/* not yet implemented */
pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on canusb devices");
return (-1);
}
static int
canusb_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
canusb_setfilter_linux(pcap_t *p, struct bpf_program *fp)
{
/* not yet implemented */
return 0;
}
static int
canusb_setdirection_linux(pcap_t *p, pcap_direction_t d)
{
/* no support for PCAP_D_OUT */
if (d == PCAP_D_OUT)
{
pcap_snprintf(p->errbuf, sizeof(p->errbuf),
"Setting direction to PCAP_D_OUT is not supported on this interface");
return -1;
}
p->direction = d;
return 0;
}
/* eof */