The Tcpdump Group git mirrors - libpcap/blob - pcap-canusb-linux.c

   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
  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
 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 *
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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 */