candump.c

   1 /*
   2  *  $Id$
   3  */
   4
   5 /*
   6  * candump.c
   7  *
   8  * Copyright (c) 2002-2009 Volkswagen Group Electronic Research
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of Volkswagen nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * Alternatively, provided that this notice is retained in full, this
  24  * software may be distributed under the terms of the GNU General
  25  * Public License ("GPL") version 2, in which case the provisions of the
  26  * GPL apply INSTEAD OF those given above.
  27  *
  28  * The provided data structures and external interfaces from this code
  29  * are not restricted to be used by modules with a GPL compatible license.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  42  * DAMAGE.
  43  *
  44  * Send feedback to <linux-can@vger.kernel.org>
  45  *
  46  */
  47
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <unistd.h>
  51 #include <string.h>
  52 #include <signal.h>
  53 #include <ctype.h>
  54 #include <libgen.h>
  55 #include <time.h>
  56
  57 #include <sys/time.h>
  58 #include <sys/types.h>
  59 #include <sys/socket.h>
  60 #include <sys/ioctl.h>
  61 #include <sys/uio.h>
  62 #include <net/if.h>
  63
  64 #include <linux/can.h>
  65 #include <linux/can/raw.h>
  66
  67 #include "terminal.h"
  68 #include "lib.h"
  69
  70 #define MAXSOCK 16    /* max. number of CAN interfaces given on the cmdline */
  71 #define MAXIFNAMES 30 /* size of receive name index to omit ioctls */
  72 #define MAXCOL 6      /* number of different colors for colorized output */
  73 #define ANYDEV "any"  /* name of interface to receive from any CAN interface */
  74 #define ANL "\r\n"    /* newline in ASC mode */
  75
  76 #define SILENT_INI 42 /* detect user setting on commandline */
  77 #define SILENT_OFF 0  /* no silent mode */
  78 #define SILENT_ANI 1  /* silent mode with animation */
  79 #define SILENT_ON  2  /* silent mode (completely silent) */
  80
  81 #define BOLD    ATTBOLD
  82 #define RED     ATTBOLD FGRED
  83 #define GREEN   ATTBOLD FGGREEN
  84 #define YELLOW  ATTBOLD FGYELLOW
  85 #define BLUE    ATTBOLD FGBLUE
  86 #define MAGENTA ATTBOLD FGMAGENTA
  87 #define CYAN    ATTBOLD FGCYAN
  88
  89 const char col_on [MAXCOL][19] = {BLUE, RED, GREEN, BOLD, MAGENTA, CYAN};
  90 const char col_off [] = ATTRESET;
  91
  92 static char *cmdlinename[MAXSOCK];
  93 static __u32 dropcnt[MAXSOCK];
  94 static __u32 last_dropcnt[MAXSOCK];
  95 static char devname[MAXIFNAMES][IFNAMSIZ+1];
  96 static int  dindex[MAXIFNAMES];
  97 static int  max_devname_len; /* to prevent frazzled device name output */
  98
  99 #define MAXANI 4
 100 const char anichar[MAXANI] = {'|', '/', '-', '\\'};
 101
 102 extern int optind, opterr, optopt;
 103
 104 static volatile int running = 1;
 105
 106 void print_usage(char *prg)
 107 {
 108         fprintf(stderr, "\nUsage: %s [options] <CAN interface>+\n", prg);
 109         fprintf(stderr, "  (use CTRL-C to terminate %s)\n\n", prg);
 110         fprintf(stderr, "Options: -t <type>   (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)\n");
 111         fprintf(stderr, "         -c          (increment color mode level)\n");
 112         fprintf(stderr, "         -i          (binary output - may exceed 80 chars/line)\n");
 113         fprintf(stderr, "         -a          (enable additional ASCII output)\n");
 114         fprintf(stderr, "         -S          (swap byte order in printed CAN data[] - marked with '%c' )\n", SWAP_DELIMITER);
 115         fprintf(stderr, "         -s <level>  (silent mode - %d: off (default) %d: animation %d: silent)\n", SILENT_OFF, SILENT_ANI, SILENT_ON);
 116         fprintf(stderr, "         -b <can>    (bridge mode - send received frames to <can>)\n");
 117         fprintf(stderr, "         -B <can>    (bridge mode - like '-b' with disabled loopback)\n");
 118         fprintf(stderr, "         -u <usecs>  (delay bridge forwarding by <usecs> microseconds)\n");
 119         fprintf(stderr, "         -l          (log CAN-frames into file. Sets '-s %d' by default)\n", SILENT_ON);
 120         fprintf(stderr, "         -L          (use log file format on stdout)\n");
 121         fprintf(stderr, "         -n <count>  (terminate after receiption of <count> CAN frames)\n");
 122         fprintf(stderr, "         -r <size>   (set socket receive buffer to <size>)\n");
 123         fprintf(stderr, "         -d          (monitor dropped CAN frames)\n");
 124         fprintf(stderr, "         -e          (dump CAN error frames in human-readable format)\n");
 125         fprintf(stderr, "\n");
 126         fprintf(stderr, "Up to %d CAN interfaces with optional filter sets can be specified\n", MAXSOCK);
 127         fprintf(stderr, "on the commandline in the form: <ifname>[,filter]*\n");
 128         fprintf(stderr, "\nComma separated filters can be specified for each given CAN interface:\n");
 129         fprintf(stderr, " <can_id>:<can_mask> (matches when <received_can_id> & mask == can_id & mask)\n");
 130         fprintf(stderr, " <can_id>~<can_mask> (matches when <received_can_id> & mask != can_id & mask)\n");
 131         fprintf(stderr, " #<error_mask>       (set error frame filter, see include/linux/can/error.h)\n");
 132         fprintf(stderr, "\nCAN IDs, masks and data content are given and expected in hexadecimal values.\n");
 133         fprintf(stderr, "When can_id and can_mask are both 8 digits, they are assumed to be 29 bit EFF.\n");
 134         fprintf(stderr, "Without any given filter all data frames are received ('0:0' default filter).\n");
 135         fprintf(stderr, "\nUse interface name '%s' to receive from all CAN interfaces.\n", ANYDEV);
 136         fprintf(stderr, "\nExamples:\n");
 137         fprintf(stderr, "%s -c -c -ta can0,123:7FF,400:700,#000000FF can2,400~7F0 can3 can8\n", prg);
 138         fprintf(stderr, "%s -l any,0~0,#FFFFFFFF    (log only error frames but no(!) data frames)\n", prg);
 139         fprintf(stderr, "%s -l any,0:0,#FFFFFFFF    (log error frames and also all data frames)\n", prg);
 140         fprintf(stderr, "%s vcan2,92345678:DFFFFFFF (match only for extended CAN ID 12345678)\n", prg);
 141         fprintf(stderr, "%s vcan2,123:7FF (matches CAN ID 123 - including EFF and RTR frames)\n", prg);
 142         fprintf(stderr, "%s vcan2,123:C00007FF (matches CAN ID 123 - only SFF and non-RTR frames)\n", prg);
 143         fprintf(stderr, "\n");
 144 }
 145
 146 void sigterm(int signo)
 147 {
 148         running = 0;
 149 }
 150
 151 int idx2dindex(int ifidx, int socket) {
 152
 153         int i;
 154         struct ifreq ifr;
 155
 156         for (i=0; i < MAXIFNAMES; i++) {
 157                 if (dindex[i] == ifidx)
 158                         return i;
 159         }
 160
 161         /* create new interface index cache entry */
 162
 163         /* remove index cache zombies first */
 164         for (i=0; i < MAXIFNAMES; i++) {
 165                 if (dindex[i]) {
 166                         ifr.ifr_ifindex = dindex[i];
 167                         if (ioctl(socket, SIOCGIFNAME, &ifr) < 0)
 168                                 dindex[i] = 0;
 169                 }
 170         }
 171
 172         for (i=0; i < MAXIFNAMES; i++)
 173                 if (!dindex[i]) /* free entry */
 174                         break;
 175
 176         if (i == MAXIFNAMES) {
 177                 fprintf(stderr, "Interface index cache only supports %d interfaces.\n",
 178                        MAXIFNAMES);
 179                 exit(1);
 180         }
 181
 182         dindex[i] = ifidx;
 183
 184         ifr.ifr_ifindex = ifidx;
 185         if (ioctl(socket, SIOCGIFNAME, &ifr) < 0)
 186                 perror("SIOCGIFNAME");
 187
 188         if (max_devname_len < strlen(ifr.ifr_name))
 189                 max_devname_len = strlen(ifr.ifr_name);
 190
 191         strcpy(devname[i], ifr.ifr_name);
 192
 193 #ifdef DEBUG
 194         printf("new index %d (%s)\n", i, devname[i]);
 195 #endif
 196
 197         return i;
 198 }
 199
 200 int main(int argc, char **argv)
 201 {
 202         fd_set rdfs;
 203         int s[MAXSOCK];
 204         int bridge = 0;
 205         useconds_t bridge_delay = 0;
 206         unsigned char timestamp = 0;
 207         unsigned char dropmonitor = 0;
 208         unsigned char silent = SILENT_INI;
 209         unsigned char silentani = 0;
 210         unsigned char color = 0;
 211         unsigned char view = 0;
 212         unsigned char log = 0;
 213         unsigned char logfrmt = 0;
 214         int count = 0;
 215         int rcvbuf_size = 0;
 216         int opt, ret;
 217         int currmax, numfilter;
 218         char *ptr, *nptr;
 219         struct sockaddr_can addr;
 220         char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
 221         struct iovec iov;
 222         struct msghdr msg;
 223         struct cmsghdr *cmsg;
 224         struct can_filter *rfilter;
 225         can_err_mask_t err_mask;
 226         struct can_frame frame;
 227         int nbytes, i;
 228         struct ifreq ifr;
 229         struct timeval tv, last_tv;
 230         FILE *logfile = NULL;
 231
 232         signal(SIGTERM, sigterm);
 233         signal(SIGHUP, sigterm);
 234         signal(SIGINT, sigterm);
 235
 236         last_tv.tv_sec  = 0;
 237         last_tv.tv_usec = 0;
 238
 239         while ((opt = getopt(argc, argv, "t:ciaSs:b:B:u:ldLn:r:he?")) != -1) {
 240                 switch (opt) {
 241                 case 't':
 242                         timestamp = optarg[0];
 243                         if ((timestamp != 'a') && (timestamp != 'A') &&
 244                             (timestamp != 'd') && (timestamp != 'z')) {
 245                                 fprintf(stderr, "%s: unknown timestamp mode '%c' - ignored\n",
 246                                        basename(argv[0]), optarg[0]);
 247                                 timestamp = 0;
 248                         }
 249                         break;
 250
 251                 case 'c':
 252                         color++;
 253                         break;
 254
 255                 case 'i':
 256                         view |= CANLIB_VIEW_BINARY;
 257                         break;
 258
 259                 case 'a':
 260                         view |= CANLIB_VIEW_ASCII;
 261                         break;
 262
 263                 case 'S':
 264                         view |= CANLIB_VIEW_SWAP;
 265                         break;
 266
 267                 case 'e':
 268                         view |= CANLIB_VIEW_ERROR;
 269                         break;
 270
 271                 case 's':
 272                         silent = atoi(optarg);
 273                         if (silent > SILENT_ON) {
 274                                 print_usage(basename(argv[0]));
 275                                 exit(1);
 276                         }
 277                         break;
 278
 279                 case 'b':
 280                 case 'B':
 281                         if (strlen(optarg) >= IFNAMSIZ) {
 282                                 fprintf(stderr, "Name of CAN device '%s' is too long!\n\n", optarg);
 283                                 return 1;
 284                         } else {
 285                                 bridge = socket(PF_CAN, SOCK_RAW, CAN_RAW);
 286                                 if (bridge < 0) {
 287                                         perror("bridge socket");
 288                                         return 1;
 289                                 }
 290                                 addr.can_family = AF_CAN;
 291                                 strcpy(ifr.ifr_name, optarg);
 292                                 if (ioctl(bridge, SIOCGIFINDEX, &ifr) < 0)
 293                                         perror("SIOCGIFINDEX");
 294                                 addr.can_ifindex = ifr.ifr_ifindex;
 295
 296                                 if (!addr.can_ifindex) {
 297                                         perror("invalid bridge interface");
 298                                         return 1;
 299                                 }
 300
 301                                 /* disable default receive filter on this write-only RAW socket */
 302                                 setsockopt(bridge, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
 303
 304                                 if (opt == 'B') {
 305                                         const int loopback = 0;
 306
 307                                         setsockopt(bridge, SOL_CAN_RAW, CAN_RAW_LOOPBACK,
 308                                                    &loopback, sizeof(loopback));
 309                                 }
 310
 311                                 if (bind(bridge, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 312                                         perror("bridge bind");
 313                                         return 1;
 314                                 }
 315                         }
 316                         break;
 317
 318                 case 'u':
 319                         bridge_delay = (useconds_t)strtoul(optarg, (char **)NULL, 10);
 320                         break;
 321
 322                 case 'l':
 323                         log = 1;
 324                         break;
 325
 326                 case 'd':
 327                         dropmonitor = 1;
 328                         break;
 329
 330                 case 'L':
 331                         logfrmt = 1;
 332                         break;
 333
 334                 case 'n':
 335                         count = atoi(optarg);
 336                         if (count < 1) {
 337                                 print_usage(basename(argv[0]));
 338                                 exit(1);
 339                         }
 340                         break;
 341
 342                 case 'r':
 343                         rcvbuf_size = atoi(optarg);
 344                         if (rcvbuf_size < 1) {
 345                                 print_usage(basename(argv[0]));
 346                                 exit(1);
 347                         }
 348                         break;
 349
 350                 default:
 351                         print_usage(basename(argv[0]));
 352                         exit(1);
 353                         break;
 354                 }
 355         }
 356
 357         if (optind == argc) {
 358                 print_usage(basename(argv[0]));
 359                 exit(0);
 360         }
 361
 362         if (logfrmt && view) {
 363                 fprintf(stderr, "Log file format selected: Please disable ASCII/BINARY/SWAP options!\n");
 364                 exit(0);
 365         }
 366
 367         if (silent == SILENT_INI) {
 368                 if (log) {
 369                         fprintf(stderr, "Disabled standard output while logging.\n");
 370                         silent = SILENT_ON; /* disable output on stdout */
 371                 } else
 372                         silent = SILENT_OFF; /* default output */
 373         }
 374
 375         currmax = argc - optind; /* find real number of CAN devices */
 376
 377         if (currmax > MAXSOCK) {
 378                 fprintf(stderr, "More than %d CAN devices given on commandline!\n", MAXSOCK);
 379                 return 1;
 380         }
 381
 382         for (i=0; i < currmax; i++) {
 383
 384                 ptr = argv[optind+i];
 385                 nptr = strchr(ptr, ',');
 386
 387 #ifdef DEBUG
 388                 printf("open %d '%s'.\n", i, ptr);
 389 #endif
 390
 391                 s[i] = socket(PF_CAN, SOCK_RAW, CAN_RAW);
 392                 if (s[i] < 0) {
 393                         perror("socket");
 394                         return 1;
 395                 }
 396
 397                 cmdlinename[i] = ptr; /* save pointer to cmdline name of this socket */
 398
 399                 if (nptr)
 400                         nbytes = nptr - ptr;  /* interface name is up the first ',' */
 401                 else
 402                         nbytes = strlen(ptr); /* no ',' found => no filter definitions */
 403
 404                 if (nbytes >= IFNAMSIZ) {
 405                         fprintf(stderr, "name of CAN device '%s' is too long!\n", ptr);
 406                         return 1;
 407                 }
 408
 409                 if (nbytes > max_devname_len)
 410                         max_devname_len = nbytes; /* for nice printing */
 411
 412                 addr.can_family = AF_CAN;
 413
 414                 memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
 415                 strncpy(ifr.ifr_name, ptr, nbytes);
 416
 417 #ifdef DEBUG
 418                 printf("using interface name '%s'.\n", ifr.ifr_name);
 419 #endif
 420
 421                 if (strcmp(ANYDEV, ifr.ifr_name)) {
 422                         if (ioctl(s[i], SIOCGIFINDEX, &ifr) < 0) {
 423                                 perror("SIOCGIFINDEX");
 424                                 exit(1);
 425                         }
 426                         addr.can_ifindex = ifr.ifr_ifindex;
 427                 } else
 428                         addr.can_ifindex = 0; /* any can interface */
 429
 430                 if (nptr) {
 431
 432                         /* found a ',' after the interface name => check for filters */
 433
 434                         /* determine number of filters to alloc the filter space */
 435                         numfilter = 0;
 436                         ptr = nptr;
 437                         while (ptr) {
 438                                 numfilter++;
 439                                 ptr++; /* hop behind the ',' */
 440                                 ptr = strchr(ptr, ','); /* exit condition */
 441                         }
 442
 443                         rfilter = malloc(sizeof(struct can_filter) * numfilter);
 444                         if (!rfilter) {
 445                                 fprintf(stderr, "Failed to create filter space!\n");
 446                                 return 1;
 447                         }
 448
 449                         numfilter = 0;
 450                         err_mask = 0;
 451
 452                         while (nptr) {
 453
 454                                 ptr = nptr+1; /* hop behind the ',' */
 455                                 nptr = strchr(ptr, ','); /* update exit condition */
 456
 457                                 if (sscanf(ptr, "%x:%x",
 458                                            &rfilter[numfilter].can_id,
 459                                            &rfilter[numfilter].can_mask) == 2) {
 460                                         rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
 461                                         numfilter++;
 462                                 } else if (sscanf(ptr, "%x~%x",
 463                                                   &rfilter[numfilter].can_id,
 464                                                   &rfilter[numfilter].can_mask) == 2) {
 465                                         rfilter[numfilter].can_id |= CAN_INV_FILTER;
 466                                         rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG;
 467                                         numfilter++;
 468                                 } else if (sscanf(ptr, "#%x", &err_mask) != 1) {
 469                                         fprintf(stderr, "Error in filter option parsing: '%s'\n", ptr);
 470                                         return 1;
 471                                 }
 472                         }
 473
 474                         if (err_mask)
 475                                 setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
 476                                            &err_mask, sizeof(err_mask));
 477
 478                         if (numfilter)
 479                                 setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_FILTER,
 480                                            rfilter, numfilter * sizeof(struct can_filter));
 481
 482                         free(rfilter);
 483
 484                 } /* if (nptr) */
 485
 486                 if (rcvbuf_size) {
 487
 488                         int curr_rcvbuf_size;
 489                         socklen_t curr_rcvbuf_size_len = sizeof(curr_rcvbuf_size);
 490
 491                         /* try SO_RCVBUFFORCE first, if we run with CAP_NET_ADMIN */
 492                         if (setsockopt(s[i], SOL_SOCKET, SO_RCVBUFFORCE,
 493                                        &rcvbuf_size, sizeof(rcvbuf_size)) < 0) {
 494 #ifdef DEBUG
 495                                 printf("SO_RCVBUFFORCE failed so try SO_RCVBUF ...\n");
 496 #endif
 497                                 if (setsockopt(s[i], SOL_SOCKET, SO_RCVBUF,
 498                                                &rcvbuf_size, sizeof(rcvbuf_size)) < 0) {
 499                                         perror("setsockopt SO_RCVBUF");
 500                                         return 1;
 501                                 }
 502
 503                                 if (getsockopt(s[i], SOL_SOCKET, SO_RCVBUF,
 504                                                &curr_rcvbuf_size, &curr_rcvbuf_size_len) < 0) {
 505                                         perror("getsockopt SO_RCVBUF");
 506                                         return 1;
 507                                 }
 508
 509                                 /* Only print a warning the first time we detect the adjustment */
 510                                 /* n.b.: The wanted size is doubled in Linux in net/sore/sock.c */
 511                                 if (!i && curr_rcvbuf_size < rcvbuf_size*2)
 512                                         fprintf(stderr, "The socket receive buffer size was "
 513                                                 "adjusted due to /proc/sys/net/core/rmem_max.\n");
 514                         }
 515                 }
 516
 517                 if (timestamp || log || logfrmt) {
 518
 519                         const int timestamp_on = 1;
 520
 521                         if (setsockopt(s[i], SOL_SOCKET, SO_TIMESTAMP,
 522                                        &timestamp_on, sizeof(timestamp_on)) < 0) {
 523                                 perror("setsockopt SO_TIMESTAMP");
 524                                 return 1;
 525                         }
 526                 }
 527
 528                 if (dropmonitor) {
 529
 530                         const int dropmonitor_on = 1;
 531
 532                         if (setsockopt(s[i], SOL_SOCKET, SO_RXQ_OVFL,
 533                                        &dropmonitor_on, sizeof(dropmonitor_on)) < 0) {
 534                                 perror("setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
 535                                 return 1;
 536                         }
 537                 }
 538
 539                 if (bind(s[i], (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 540                         perror("bind");
 541                         return 1;
 542                 }
 543         }
 544
 545         if (log) {
 546                 time_t currtime;
 547                 struct tm now;
 548                 char fname[sizeof("candump-2006-11-20_202026.log")+1];
 549
 550                 if (time(&currtime) == (time_t)-1) {
 551                         perror("time");
 552                         return 1;
 553                 }
 554
 555                 localtime_r(&currtime, &now);
 556
 557                 sprintf(fname, "candump-%04d-%02d-%02d_%02d%02d%02d.log",
 558                         now.tm_year + 1900,
 559                         now.tm_mon + 1,
 560                         now.tm_mday,
 561                         now.tm_hour,
 562                         now.tm_min,
 563                         now.tm_sec);
 564
 565                 if (silent != SILENT_ON)
 566                         printf("\nWarning: console output active while logging!");
 567
 568                 fprintf(stderr, "\nEnabling Logfile '%s'\n\n", fname);
 569
 570                 logfile = fopen(fname, "w");
 571                 if (!logfile) {
 572                         perror("logfile");
 573                         return 1;
 574                 }
 575         }
 576
 577         /* these settings are static and can be held out of the hot path */
 578         iov.iov_base = &frame;
 579         msg.msg_name = &addr;
 580         msg.msg_iov = &iov;
 581         msg.msg_iovlen = 1;
 582         msg.msg_control = &ctrlmsg;
 583
 584         while (running) {
 585
 586                 FD_ZERO(&rdfs);
 587                 for (i=0; i<currmax; i++)
 588                         FD_SET(s[i], &rdfs);
 589
 590                 if ((ret = select(s[currmax-1]+1, &rdfs, NULL, NULL, NULL)) < 0) {
 591                         //perror("select");
 592                         running = 0;
 593                         continue;
 594                 }
 595
 596                 for (i=0; i<currmax; i++) {  /* check all CAN RAW sockets */
 597
 598                         if (FD_ISSET(s[i], &rdfs)) {
 599
 600                                 int idx;
 601
 602                                 /* these settings may be modified by recvmsg() */
 603                                 iov.iov_len = sizeof(frame);
 604                                 msg.msg_namelen = sizeof(addr);
 605                                 msg.msg_controllen = sizeof(ctrlmsg);
 606                                 msg.msg_flags = 0;
 607
 608                                 nbytes = recvmsg(s[i], &msg, 0);
 609                                 if (nbytes < 0) {
 610                                         perror("read");
 611                                         return 1;
 612                                 }
 613
 614                                 if (nbytes < sizeof(struct can_frame)) {
 615                                         fprintf(stderr, "read: incomplete CAN frame\n");
 616                                         return 1;
 617                                 }
 618
 619                                 if (count && (--count == 0))
 620                                         running = 0;
 621
 622                                 if (bridge) {
 623                                         if (bridge_delay)
 624                                                 usleep(bridge_delay);
 625
 626                                         nbytes = write(bridge, &frame, sizeof(struct can_frame));
 627                                         if (nbytes < 0) {
 628                                                 perror("bridge write");
 629                                                 return 1;
 630                                         } else if (nbytes < sizeof(struct can_frame)) {
 631                                                 fprintf(stderr,"bridge write: incomplete CAN frame\n");
 632                                                 return 1;
 633                                         }
 634                                 }
 635
 636                                 for (cmsg = CMSG_FIRSTHDR(&msg);
 637                                      cmsg && (cmsg->cmsg_level == SOL_SOCKET);
 638                                      cmsg = CMSG_NXTHDR(&msg,cmsg)) {
 639                                         if (cmsg->cmsg_type == SO_TIMESTAMP)
 640                                                 tv = *(struct timeval *)CMSG_DATA(cmsg);
 641                                         else if (cmsg->cmsg_type == SO_RXQ_OVFL)
 642                                                 dropcnt[i] = *(__u32 *)CMSG_DATA(cmsg);
 643                                 }
 644
 645                                 /* check for (unlikely) dropped frames on this specific socket */
 646                                 if (dropcnt[i] != last_dropcnt[i]) {
 647
 648                                         __u32 frames;
 649
 650                                         if (dropcnt[i] > last_dropcnt[i])
 651                                                 frames = dropcnt[i] - last_dropcnt[i];
 652                                         else
 653                                                 frames = 4294967295U - last_dropcnt[i] + dropcnt[i]; /* 4294967295U == UINT32_MAX */
 654
 655                                         if (silent != SILENT_ON)
 656                                                 printf("DROPCOUNT: dropped %d CAN frame%s on '%s' socket (total drops %d)\n",
 657                                                        frames, (frames > 1)?"s":"", cmdlinename[i], dropcnt[i]);
 658
 659                                         if (log)
 660                                                 fprintf(logfile, "DROPCOUNT: dropped %d CAN frame%s on '%s' socket (total drops %d)\n",
 661                                                         frames, (frames > 1)?"s":"", cmdlinename[i], dropcnt[i]);
 662
 663                                         last_dropcnt[i] = dropcnt[i];
 664                                 }
 665
 666                                 idx = idx2dindex(addr.can_ifindex, s[i]);
 667
 668                                 if (log) {
 669                                         /* log CAN frame with absolute timestamp & device */
 670                                         fprintf(logfile, "(%ld.%06ld) ", tv.tv_sec, tv.tv_usec);
 671                                         fprintf(logfile, "%*s ", max_devname_len, devname[idx]);
 672                                         /* without seperator as logfile use-case is parsing */
 673                                         fprint_canframe(logfile, &frame, "\n", 0);
 674                                 }
 675
 676                                 if (logfrmt) {
 677                                         /* print CAN frame in log file style to stdout */
 678                                         printf("(%ld.%06ld) ", tv.tv_sec, tv.tv_usec);
 679                                         printf("%*s ", max_devname_len, devname[idx]);
 680                                         fprint_canframe(stdout, &frame, "\n", 0);
 681                                         goto out_fflush; /* no other output to stdout */
 682                                 }
 683
 684                                 if (silent != SILENT_OFF){
 685                                         if (silent == SILENT_ANI) {
 686                                                 printf("%c\b", anichar[silentani%=MAXANI]);
 687                                                 silentani++;
 688                                         }
 689                                         goto out_fflush; /* no other output to stdout */
 690                                 }
 691
 692                                 printf(" %s", (color>2)?col_on[idx%MAXCOL]:"");
 693
 694                                 switch (timestamp) {
 695
 696                                 case 'a': /* absolute with timestamp */
 697                                         printf("(%ld.%06ld) ", tv.tv_sec, tv.tv_usec);
 698                                         break;
 699
 700                                 case 'A': /* absolute with date */
 701                                 {
 702                                         struct tm tm;
 703                                         char timestring[25];
 704
 705                                         tm = *localtime(&tv.tv_sec);
 706                                         strftime(timestring, 24, "%Y-%m-%d %H:%M:%S", &tm);
 707                                         printf("(%s.%06ld) ", timestring, tv.tv_usec);
 708                                 }
 709                                 break;
 710
 711                                 case 'd': /* delta */
 712                                 case 'z': /* starting with zero */
 713                                 {
 714                                         struct timeval diff;
 715
 716                                         if (last_tv.tv_sec == 0)   /* first init */
 717                                                 last_tv = tv;
 718                                         diff.tv_sec  = tv.tv_sec  - last_tv.tv_sec;
 719                                         diff.tv_usec = tv.tv_usec - last_tv.tv_usec;
 720                                         if (diff.tv_usec < 0)
 721                                                 diff.tv_sec--, diff.tv_usec += 1000000;
 722                                         if (diff.tv_sec < 0)
 723                                                 diff.tv_sec = diff.tv_usec = 0;
 724                                         printf("(%03ld.%06ld) ", diff.tv_sec, diff.tv_usec);
 725
 726                                         if (timestamp == 'd')
 727                                                 last_tv = tv; /* update for delta calculation */
 728                                 }
 729                                 break;
 730
 731                                 default: /* no timestamp output */
 732                                         break;
 733                                 }
 734
 735                                 printf(" %s", (color && (color<3))?col_on[idx%MAXCOL]:"");
 736                                 printf("%*s", max_devname_len, devname[idx]);
 737                                 printf("%s  ", (color==1)?col_off:"");
 738
 739                                 fprint_long_canframe(stdout, &frame, NULL, view);
 740
 741                                 printf("%s", (color>1)?col_off:"");
 742                                 printf("\n");
 743                         }
 744
 745                 out_fflush:
 746                         fflush(stdout);
 747                 }
 748         }
 749
 750         for (i=0; i<currmax; i++)
 751                 close(s[i]);
 752
 753         if (bridge)
 754                 close(bridge);
 755
 756         if (log)
 757                 fclose(logfile);
 758
 759         return 0;
 760 }