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 * Sockettrace 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 <libusb-1.0/libusb.h>
40
41 #include <stdlib.h>
42 #include <unistd.h>
43 #include <fcntl.h>
44 #include <errno.h>
45 #include <string.h>
46 #include <pthread.h>
47
48 #include "pcap-int.h"
49 #include "pcap-canusb-linux.h"
50
51 #define CANUSB_IFACE "canusb"
52
53 #define CANUSB_VID 0x0403
54 #define CANUSB_PID 0x8990
55
56 #define USE_THREAD 1
57
58 #if USE_THREAD == 0
59 #include <signal.h>
60 #endif
61
62
63 /* forward declaration */
64 static int canusb_activate(pcap_t *);
65 static int canusb_read_linux(pcap_t *, int , pcap_handler , u_char *);
66 static int canusb_inject_linux(pcap_t *, const void *, size_t);
67 static int canusb_setfilter_linux(pcap_t *, struct bpf_program *);
68 static int canusb_setdirection_linux(pcap_t *, pcap_direction_t);
69 static int canusb_stats_linux(pcap_t *, struct pcap_stat *);
70
71 struct CAN_Msg
72 {
73 uint32_t timestamp;
74 uint32_t id;
75 uint32_t length;
76 uint8_t data[8];
77 };
78
79 /*
80 * Private data for capturing on Linux CANbus USB devices.
81 */
82 struct pcap_canusb {
83 libusb_context *ctx;
84 libusb_device_handle *dev;
85 pthread_t worker;
86 int rdpipe, wrpipe;
87 volatile int loop;
88 };
89
canusb_findalldevs(pcap_if_t ** alldevsp,char * err_str)90 int canusb_findalldevs(pcap_if_t **alldevsp, char *err_str)
91 {
92 libusb_context *fdctx;
93 libusb_device** devs;
94 unsigned char sernum[65];
95 int cnt, i;
96
97 if (libusb_init(&fdctx) != 0) {
98 /*
99 * XXX - if this doesn't just mean "no USB file system mounted",
100 * perhaps we should report a real error rather than just
101 * saying "no CANUSB devices".
102 */
103 return 0;
104 }
105
106 cnt = libusb_get_device_list(fdctx,&devs);
107
108 for(i=0;i<cnt;i++)
109 {
110 int ret;
111 // Check if this device is interesting.
112 struct libusb_device_descriptor desc;
113 libusb_get_device_descriptor(devs[i],&desc);
114
115 if ((desc.idVendor != CANUSB_VID) || (desc.idProduct != CANUSB_PID))
116 continue; //It is not, check next device
117
118 //It is!
119 libusb_device_handle *dh = NULL;
120
121 if ((ret = libusb_open(devs[i],&dh)) == 0)
122 {
123 char dev_name[30];
124 char dev_descr[50];
125 int n = libusb_get_string_descriptor_ascii(dh,desc.iSerialNumber,sernum,64);
126 sernum[n] = 0;
127
128 snprintf(dev_name, 30, CANUSB_IFACE"%s", sernum);
129 snprintf(dev_descr, 50, "CanUSB [%s]", sernum);
130
131 libusb_close(dh);
132
133 if (pcap_add_if(alldevsp, dev_name, 0, dev_descr, err_str) < 0)
134 {
135 libusb_free_device_list(devs,1);
136 libusb_exit(fdctx);
137 return -1;
138 }
139 }
140 }
141
142 libusb_free_device_list(devs,1);
143 libusb_exit(fdctx);
144 return 0;
145 }
146
canusb_opendevice(struct libusb_context * ctx,char * devserial)147 static libusb_device_handle* canusb_opendevice(struct libusb_context *ctx, char* devserial)
148 {
149 libusb_device** devs;
150 unsigned char serial[65];
151 int cnt,i,n;
152
153 cnt = libusb_get_device_list(ctx,&devs);
154
155 for(i=0;i<cnt;i++)
156 {
157 // Check if this device is interesting.
158 struct libusb_device_descriptor desc;
159 libusb_get_device_descriptor(devs[i],&desc);
160
161 if ((desc.idVendor != CANUSB_VID) || (desc.idProduct != CANUSB_PID))
162 continue;
163
164 //Found one!
165 libusb_device_handle *dh = NULL;
166
167 if (libusb_open(devs[i],&dh) != 0) continue;
168
169 n = libusb_get_string_descriptor_ascii(dh,desc.iSerialNumber,serial,64);
170 serial[n] = 0;
171
172 if ((devserial) && (strcmp((char *)serial,devserial) != 0))
173 {
174 libusb_close(dh);
175 continue;
176 }
177
178 if ((libusb_kernel_driver_active(dh,0)) && (libusb_detach_kernel_driver(dh,0) != 0))
179 {
180 libusb_close(dh);
181 continue;
182 }
183
184 if (libusb_set_configuration(dh,1) != 0)
185 {
186 libusb_close(dh);
187 continue;
188 }
189
190 if (libusb_claim_interface(dh,0) != 0)
191 {
192 libusb_close(dh);
193 continue;
194 }
195
196 //Fount it!
197 libusb_free_device_list(devs,1);
198 return dh;
199 }
200
201 libusb_free_device_list(devs,1);
202 return NULL;
203 }
204
205
206 pcap_t *
canusb_create(const char * device,char * ebuf,int * is_ours)207 canusb_create(const char *device, char *ebuf, int *is_ours)
208 {
209 const char *cp;
210 char *cpend;
211 long devnum;
212 pcap_t* p;
213 struct pcap_canusb *canusb;
214
215 /* Does this look like a DAG device? */
216 cp = strrchr(device, '/');
217 if (cp == NULL)
218 cp = device;
219 /* Does it begin with "canusb"? */
220 if (strncmp(cp, "canusb", 6) != 0) {
221 /* Nope, doesn't begin with "canusb" */
222 *is_ours = 0;
223 return NULL;
224 }
225 /* Yes - is "canusb" followed by a number? */
226 cp += 6;
227 devnum = strtol(cp, &cpend, 10);
228 if (cpend == cp || *cpend != '\0') {
229 /* Not followed by a number. */
230 *is_ours = 0;
231 return NULL;
232 }
233 if (devnum < 0) {
234 /* Followed by a non-valid number. */
235 *is_ours = 0;
236 return NULL;
237 }
238
239 /* OK, it's probably ours. */
240 *is_ours = 1;
241
242 p = pcap_create_common(device, ebuf, sizeof (struct pcap_canusb));
243 if (p == NULL)
244 return (NULL);
245
246 canusb = p->priv;
247 canusb->ctx = NULL;
248 canusb->dev = NULL;
249 canusb->rdpipe = -1;
250 canusb->wrpipe = -1;
251
252 p->activate_op = canusb_activate;
253
254 return (p);
255 }
256
257
canusb_capture_thread(void * arg)258 static void* canusb_capture_thread(void *arg)
259 {
260 struct pcap_canusb *canusb = arg;
261 int i;
262 struct
263 {
264 uint8_t rxsz, txsz;
265 } status;
266
267 fcntl(canusb->wrpipe, F_SETFL, O_NONBLOCK);
268
269 while(canusb->loop)
270 {
271 int sz;
272 struct CAN_Msg msg;
273
274 libusb_interrupt_transfer(canusb->dev, 0x81, (unsigned char*)&status, sizeof(status), &sz, 100);
275 //HACK!!!!! -> drop buffered data, read new one by reading twice.
276 libusb_interrupt_transfer(canusb->dev, 0x81, (unsigned char*)&status, sizeof(status), &sz, 100);
277
278 for(i = 0; i<status.rxsz; i++)
279 {
280 libusb_bulk_transfer(canusb->dev, 0x85, (unsigned char*)&msg, sizeof(msg), &sz, 100);
281 if(write(canusb->wrpipe, &msg, sizeof(msg)) < 0)
282 fprintf(stderr,"write() error: %s\n", strerror(errno));
283 }
284
285 }
286
287 return NULL;
288 }
289
canusb_startcapture(struct pcap_canusb * this)290 static int canusb_startcapture(struct pcap_canusb* this)
291 {
292 int pipefd[2];
293
294 if (pipe(pipefd) == -1)
295 return -1;
296
297 this->rdpipe = pipefd[0];
298 this->wrpipe = pipefd[1];
299
300 this->loop = 1;
301 pthread_create(&this->worker, NULL, canusb_capture_thread, this);
302
303 return this->rdpipe;
304 }
305
canusb_clearbufs(struct pcap_canusb * this)306 static void canusb_clearbufs(struct pcap_canusb* this)
307 {
308 unsigned char cmd[16];
309 int al;
310
311 cmd[0] = 1; //Empty incoming buffer
312 cmd[1] = 1; //Empty outgoing buffer
313 cmd[3] = 0; //Not a write to serial number
314 memset(&cmd[4],0,16-4);
315
316 libusb_interrupt_transfer(this->dev, 0x1,cmd,16,&al,100);
317 }
318
319
canusb_close(pcap_t * handle)320 static void canusb_close(pcap_t* handle)
321 {
322 struct pcap_canusb *canusb = handle->priv;
323
324 canusb->loop = 0;
325 pthread_join(canusb->worker, NULL);
326
327 if (canusb->dev)
328 {
329 libusb_close(canusb->dev);
330 canusb->dev = NULL;
331 }
332 if (canusb->ctx)
333 {
334 libusb_exit(canusb->ctx);
335 canusb->ctx = NULL;
336 }
337 }
338
339
340
canusb_activate(pcap_t * handle)341 static int canusb_activate(pcap_t* handle)
342 {
343 struct pcap_canusb *canusb = handle->priv;
344 char *serial;
345
346 if (libusb_init(&canusb->ctx) != 0) {
347 /*
348 * XXX - what causes this to fail?
349 */
350 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "libusb_init() failed");
351 return PCAP_ERROR;
352 }
353
354 handle->read_op = canusb_read_linux;
355
356 handle->inject_op = canusb_inject_linux;
357 handle->setfilter_op = canusb_setfilter_linux;
358 handle->setdirection_op = canusb_setdirection_linux;
359 handle->getnonblock_op = pcap_getnonblock_fd;
360 handle->setnonblock_op = pcap_setnonblock_fd;
361 handle->stats_op = canusb_stats_linux;
362 handle->cleanup_op = canusb_close;
363
364 /* Initialize some components of the pcap structure. */
365 handle->bufsize = 32;
366 handle->offset = 8;
367 handle->linktype = DLT_CAN_SOCKETCAN;
368 handle->set_datalink_op = NULL;
369
370 serial = handle->opt.source + strlen(CANUSB_IFACE);
371
372 canusb->dev = canusb_opendevice(canusb->ctx, serial);
373 if (!canusb->dev)
374 {
375 libusb_exit(canusb->ctx);
376 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't open USB Device");
377 return PCAP_ERROR;
378 }
379
380 canusb_clearbufs(canusb);
381
382 handle->fd = canusb_startcapture(canusb);
383 handle->selectable_fd = handle->fd;
384
385 return 0;
386 }
387
388
389
390
391 static int
canusb_read_linux(pcap_t * handle,int max_packets,pcap_handler callback,u_char * user)392 canusb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
393 {
394 static struct timeval firstpacket = { -1, -1};
395 int i = 0;
396 struct CAN_Msg msg;
397 struct pcap_pkthdr pkth;
398
399 while(i < max_packets)
400 {
401 int n;
402 usleep(10 * 1000);
403 n = read(handle->fd, &msg, sizeof(msg));
404 if (n <= 0)
405 break;
406 pkth.caplen = pkth.len = n;
407 pkth.caplen -= 4;
408 pkth.caplen -= 8 - msg.length;
409
410 if ((firstpacket.tv_sec == -1) && (firstpacket.tv_usec == -1))
411 gettimeofday(&firstpacket, NULL);
412
413 pkth.ts.tv_usec = firstpacket.tv_usec + (msg.timestamp % 100) * 10000;
414 pkth.ts.tv_sec = firstpacket.tv_usec + (msg.timestamp / 100);
415 if (pkth.ts.tv_usec > 1000000)
416 {
417 pkth.ts.tv_usec -= 1000000;
418 pkth.ts.tv_sec++;
419 }
420
421 callback(user, &pkth, (void*)&msg.id);
422 i++;
423 }
424
425 return i;
426 }
427
428
429 static int
canusb_inject_linux(pcap_t * handle,const void * buf,size_t size)430 canusb_inject_linux(pcap_t *handle, const void *buf, size_t size)
431 {
432 /* not yet implemented */
433 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on canusb devices");
434 return (-1);
435 }
436
437
438 static int
canusb_stats_linux(pcap_t * handle,struct pcap_stat * stats)439 canusb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
440 {
441 /* not yet implemented */
442 stats->ps_recv = 0; /* number of packets received */
443 stats->ps_drop = 0; /* number of packets dropped */
444 stats->ps_ifdrop = 0; /* drops by interface -- only supported on some platforms */
445 return 0;
446 }
447
448
449 static int
canusb_setfilter_linux(pcap_t * p,struct bpf_program * fp)450 canusb_setfilter_linux(pcap_t *p, struct bpf_program *fp)
451 {
452 /* not yet implemented */
453 return 0;
454 }
455
456
457 static int
canusb_setdirection_linux(pcap_t * p,pcap_direction_t d)458 canusb_setdirection_linux(pcap_t *p, pcap_direction_t d)
459 {
460 /* no support for PCAP_D_OUT */
461 if (d == PCAP_D_OUT)
462 {
463 snprintf(p->errbuf, sizeof(p->errbuf),
464 "Setting direction to PCAP_D_OUT is not supported on this interface");
465 return -1;
466 }
467
468 p->direction = d;
469
470 return 0;
471 }
472
473
474 /* eof */
475