contrib/tcpdump/tcpdump.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Support for splitting captures into multiple files with a maximum
  22  * file size:
  23  *
  24  * Copyright (c) 2001
  25  *      Seth Webster <swebster@sst.ll.mit.edu>
  26  */
  27
  28 #ifndef lint
  29 static const char copyright[] =
  30     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  31 The Regents of the University of California.  All rights reserved.\n";
  32 static const char rcsid[] =
  33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.173 2001/12/22 22:12:23 guy Exp $ (LBL)";
  34 #endif
  35
  36 /* $FreeBSD$ */
  37
  38 /*
  39  * tcpdump - monitor tcp/ip traffic on an ethernet.
  40  *
  41  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  42  * Mercilessly hacked and occasionally improved since then via the
  43  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 #include "config.h"
  48 #endif
  49
  50 #include <sys/types.h>
  51 #include <sys/time.h>
  52
  53 #include <netinet/in.h>
  54
  55 #include <pcap.h>
  56 #include <signal.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60 #include <unistd.h>
  61 #include <ctype.h>
  62
  63
  64 #include "interface.h"
  65 #include "addrtoname.h"
  66 #include "machdep.h"
  67 #include "setsignal.h"
  68 #include "gmt2local.h"
  69
  70 int aflag;                      /* translate network and broadcast addresses */
  71 int dflag;                      /* print filter code */
  72 int eflag;                      /* print ethernet header */
  73 int fflag;                      /* don't translate "foreign" IP address */
  74 int Lflag;                      /* list available data link types and exit */
  75 int nflag;                      /* leave addresses as numbers */
  76 int Nflag;                      /* remove domains from printed host names */
  77 int Oflag = 1;                  /* run filter code optimizer */
  78 int pflag;                      /* don't go promiscuous */
  79 int qflag;                      /* quick (shorter) output */
  80 int Rflag = 1;                  /* print sequence # field in AH/ESP*/
  81 int sflag = 0;                  /* use the libsmi to translate OIDs */
  82 int Sflag;                      /* print raw TCP sequence numbers */
  83 int tflag = 1;                  /* print packet arrival time */
  84 int uflag = 0;                  /* Print undecoded NFS handles */
  85 int vflag;                      /* verbose */
  86 int xflag;                      /* print packet in hex */
  87 int Xflag;                      /* print packet in ascii as well as hex */
  88 off_t Cflag = 0;                /* rotate dump files after this many bytes */
  89 int dlt = -1;                   /* if != -1, ask libpcap for the DLT it names */
  90
  91 const char *dlt_name = NULL;
  92
  93 char *espsecret = NULL;         /* ESP secret key */
  94
  95 int packettype;
  96
  97 int infodelay;
  98 int infoprint;
  99
 100 char *program_name;
 101
 102 int32_t thiszone;               /* seconds offset from gmt to local time */
 103
 104 /* Forwards */
 105 static RETSIGTYPE cleanup(int);
 106 static void usage(void) __attribute__((noreturn));
 107 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 108
 109 static void dump_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 110
 111 #ifdef SIGINFO
 112 RETSIGTYPE requestinfo(int);
 113 #endif
 114
 115 /* Length of saved portion of packet. */
 116 int snaplen = DEFAULT_SNAPLEN;
 117
 118 struct printer {
 119         pcap_handler f;
 120         int type;
 121 };
 122
 123 static struct printer printers[] = {
 124         { arcnet_if_print,      DLT_ARCNET },
 125         { ether_if_print,       DLT_EN10MB },
 126         { token_if_print,       DLT_IEEE802 },
 127 #ifdef DLT_LANE8023
 128         { lane_if_print,        DLT_LANE8023 },
 129 #endif
 130 #ifdef DLT_CIP
 131         { cip_if_print,         DLT_CIP },
 132 #endif
 133 #ifdef DLT_ATM_CLIP
 134         { cip_if_print,         DLT_ATM_CLIP },
 135 #endif
 136         { sl_if_print,          DLT_SLIP },
 137         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 138         { ppp_if_print,         DLT_PPP },
 139         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 140         { fddi_if_print,        DLT_FDDI },
 141         { null_if_print,        DLT_NULL },
 142 #ifdef DLT_LOOP
 143         { null_if_print,        DLT_LOOP },
 144 #endif
 145         { raw_if_print,         DLT_RAW },
 146         { atm_if_print,         DLT_ATM_RFC1483 },
 147 #ifdef DLT_C_HDLC
 148         { chdlc_if_print,       DLT_C_HDLC },
 149 #endif
 150 #ifdef DLT_HDLC
 151         { chdlc_if_print,       DLT_HDLC },
 152 #endif
 153 #ifdef DLT_PPP_SERIAL
 154         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 155 #endif
 156 #ifdef DLT_PPP_ETHER
 157         { pppoe_if_print,       DLT_PPP_ETHER },
 158 #endif
 159 #ifdef DLT_LINUX_SLL
 160         { sll_if_print,         DLT_LINUX_SLL },
 161 #endif
 162 #ifdef DLT_IEEE802_11
 163         { ieee802_11_if_print,  DLT_IEEE802_11},
 164 #endif
 165 #ifdef DLT_LTALK
 166         { ltalk_if_print,       DLT_LTALK },
 167 #endif
 168         { NULL,                 0 },
 169 };
 170
 171 static pcap_handler
 172 lookup_printer(int type)
 173 {
 174         struct printer *p;
 175
 176         for (p = printers; p->f; ++p)
 177                 if (type == p->type)
 178                         return p->f;
 179
 180         error("unknown data link type %d", type);
 181         /* NOTREACHED */
 182 }
 183
 184 static pcap_t *pd;
 185
 186 extern int optind;
 187 extern int opterr;
 188 extern char *optarg;
 189
 190 struct dump_info {
 191         char    *WFileName;
 192         pcap_t  *pd;
 193         pcap_dumper_t *p;
 194 };
 195
 196 struct dlt_choice {
 197         const char*     name;
 198         int             dlt;
 199 };
 200
 201 #define DLT_CHOICE(code) { #code, code }
 202 #define DLT_CHOICE_SENTINEL { NULL, 0 }
 203
 204 struct dlt_choice dlt_choices[] = {
 205         DLT_CHOICE(DLT_ARCNET),
 206         DLT_CHOICE(DLT_EN10MB),
 207         DLT_CHOICE(DLT_IEEE802),
 208 #ifdef DLT_LANE8023
 209         DLT_CHOICE(DLT_LANE8023),
 210 #endif
 211 #ifdef DLT_CIP
 212         DLT_CHOICE(DLT_CIP),
 213 #endif
 214 #ifdef DLT_ATM_CLIP
 215         DLT_CHOICE(DLT_ATM_CLIP),
 216 #endif
 217         DLT_CHOICE(DLT_SLIP),
 218         DLT_CHOICE(DLT_SLIP_BSDOS),
 219         DLT_CHOICE(DLT_PPP),
 220         DLT_CHOICE(DLT_PPP_BSDOS),
 221         DLT_CHOICE(DLT_FDDI),
 222         DLT_CHOICE(DLT_NULL),
 223 #ifdef DLT_LOOP
 224         DLT_CHOICE(DLT_LOOP),
 225 #endif
 226         DLT_CHOICE(DLT_RAW),
 227         DLT_CHOICE(DLT_ATM_RFC1483),
 228 #ifdef DLT_C_HDLC
 229         DLT_CHOICE(DLT_C_HDLC),
 230 #endif
 231 #ifdef DLT_HDLC
 232         DLT_CHOICE(DLT_HDLC),
 233 #endif
 234 #ifdef DLT_PPP_SERIAL
 235         DLT_CHOICE(DLT_PPP_SERIAL),
 236 #endif
 237 #ifdef DLT_PPP_ETHER
 238         DLT_CHOICE(DLT_PPP_ETHER),
 239 #endif
 240 #ifdef DLT_LINUX_SLL
 241         DLT_CHOICE(DLT_LINUX_SLL),
 242 #endif
 243 #ifdef DLT_IEEE802_11
 244         DLT_CHOICE(DLT_IEEE802_11),
 245 #endif
 246 #ifdef DLT_LTALK
 247         DLT_CHOICE(DLT_LTALK),
 248 #endif
 249 #ifdef DLT_PFLOG
 250         DLT_CHOICE(DLT_PFLOG),
 251 #endif
 252         DLT_CHOICE_SENTINEL
 253 };
 254
 255 static void
 256 show_dlts_and_exit(pcap_t *pd)
 257 {
 258         int i, n_dlts;
 259         int *dlts = 0;
 260         n_dlts = pcap_list_datalinks(pd, &dlts);
 261         if (n_dlts < 0)
 262                 error("%s", pcap_geterr(pd));
 263         else if (n_dlts == 0 || !dlts)
 264                 error("No data link types.");
 265
 266         (void) fprintf(stderr, "Data link types (use option -y):\n");
 267
 268         while (--n_dlts >= 0) {
 269                 for (i = 0; dlt_choices[i].name; i++) {
 270                         if (dlt_choices[i].dlt != dlts[n_dlts]) {
 271                                 continue;
 272                         }
 273                         (void) fprintf(stderr, "  %s\n",
 274                                    dlt_choices[i].name + sizeof("DLT_") - 1);
 275                         break;
 276                 }
 277                 if (!dlt_choices[i].name)
 278                         fprintf(stderr, "  %d (not supported)\n", dlts[n_dlts]);
 279         }
 280         free(dlts);
 281         exit(0);
 282 }
 283
 284 int
 285 main(int argc, char **argv)
 286 {
 287         register int cnt, op, i;
 288         bpf_u_int32 localnet, netmask;
 289         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 290         pcap_handler printer;
 291         struct bpf_program fcode;
 292         RETSIGTYPE (*oldhandler)(int);
 293         struct dump_info dumpinfo;
 294         u_char *pcap_userdata;
 295         char ebuf[PCAP_ERRBUF_SIZE];
 296
 297         cnt = -1;
 298         device = NULL;
 299         infile = NULL;
 300         RFileName = NULL;
 301         WFileName = NULL;
 302         if ((cp = strrchr(argv[0], '/')) != NULL)
 303                 program_name = cp + 1;
 304         else
 305                 program_name = argv[0];
 306
 307         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 308                 error("%s", ebuf);
 309
 310 #ifdef LIBSMI
 311         smiInit("tcpdump");
 312 #endif
 313
 314         opterr = 0;
 315         while (
 316             (op = getopt(argc, argv, "ac:C:deE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 317                 switch (op) {
 318
 319                 case 'a':
 320                         ++aflag;
 321                         break;
 322
 323                 case 'c':
 324                         cnt = atoi(optarg);
 325                         if (cnt <= 0)
 326                                 error("invalid packet count %s", optarg);
 327                         break;
 328
 329                 case 'C':
 330                         Cflag = atoi(optarg) * 1000000;
 331                         if (Cflag < 0)
 332                                 error("invalid file size %s", optarg);
 333                         break;
 334
 335                 case 'd':
 336                         ++dflag;
 337                         break;
 338
 339                 case 'L':
 340                         Lflag++;
 341                         break;
 342
 343                 case 'e':
 344                         ++eflag;
 345                         break;
 346
 347                 case 'E':
 348 #ifndef HAVE_LIBCRYPTO
 349                         warning("crypto code not compiled in");
 350 #endif
 351                         espsecret = optarg;
 352                         break;
 353
 354                 case 'f':
 355                         ++fflag;
 356                         break;
 357
 358                 case 'F':
 359                         infile = optarg;
 360                         break;
 361
 362                 case 'i':
 363                         device = optarg;
 364                         break;
 365
 366                 case 'l':
 367 #ifdef HAVE_SETLINEBUF
 368                         setlinebuf(stdout);
 369 #else
 370                         setvbuf(stdout, NULL, _IOLBF, 0);
 371 #endif
 372                         break;
 373
 374                 case 'n':
 375                         ++nflag;
 376                         break;
 377
 378                 case 'N':
 379                         ++Nflag;
 380                         break;
 381
 382                 case 'm':
 383 #ifdef LIBSMI
 384                         if (smiLoadModule(optarg) == 0) {
 385                                 error("could not load MIB module %s", optarg);
 386                         }
 387                         sflag = 1;
 388 #else
 389                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 390                                       program_name, optarg);
 391                         (void)fprintf(stderr, "(no libsmi support)\n");
 392 #endif
 393
 394                 case 'O':
 395                         Oflag = 0;
 396                         break;
 397
 398                 case 'p':
 399                         ++pflag;
 400                         break;
 401
 402                 case 'q':
 403                         ++qflag;
 404                         break;
 405
 406                 case 'r':
 407                         RFileName = optarg;
 408                         break;
 409
 410                 case 'R':
 411                         Rflag = 0;
 412                         break;
 413
 414                 case 's': {
 415                         char *end;
 416
 417                         snaplen = strtol(optarg, &end, 0);
 418                         if (optarg == end || *end != '\0'
 419                             || snaplen < 0 || snaplen > 65535)
 420                                 error("invalid snaplen %s", optarg);
 421                         else if (snaplen == 0)
 422                                 snaplen = 65535;
 423                         break;
 424                 }
 425
 426                 case 'S':
 427                         ++Sflag;
 428                         break;
 429
 430                 case 't':
 431                         --tflag;
 432                         break;
 433
 434                 case 'T':
 435                         if (strcasecmp(optarg, "vat") == 0)
 436                                 packettype = PT_VAT;
 437                         else if (strcasecmp(optarg, "wb") == 0)
 438                                 packettype = PT_WB;
 439                         else if (strcasecmp(optarg, "rpc") == 0)
 440                                 packettype = PT_RPC;
 441                         else if (strcasecmp(optarg, "rtp") == 0)
 442                                 packettype = PT_RTP;
 443                         else if (strcasecmp(optarg, "rtcp") == 0)
 444                                 packettype = PT_RTCP;
 445                         else if (strcasecmp(optarg, "snmp") == 0)
 446                                 packettype = PT_SNMP;
 447                         else if (strcasecmp(optarg, "cnfp") == 0)
 448                                 packettype = PT_CNFP;
 449                         else
 450                                 error("unknown packet type `%s'", optarg);
 451                         break;
 452
 453                 case 'u':
 454                         ++uflag;
 455                         break;
 456
 457                 case 'v':
 458                         ++vflag;
 459                         break;
 460
 461                 case 'w':
 462                         WFileName = optarg;
 463                         break;
 464
 465                 case 'x':
 466                         ++xflag;
 467                         break;
 468
 469                 case 'X':
 470                         ++xflag;
 471                         ++Xflag;
 472                         break;
 473
 474                 case 'y':
 475                         for (i = 0; dlt_choices[i].name; i++) {
 476                                 if (!strcasecmp(dlt_choices[i].name +
 477                                                     sizeof("DLT_") - 1,
 478                                                 optarg)) {
 479                                         dlt = dlt_choices[i].dlt;
 480                                         dlt_name = dlt_choices[i].name;
 481                                         break;
 482                                 }
 483                         }
 484                         if (dlt < 0) {
 485                                 error("invalid data link type %s", optarg);
 486                         }
 487                         break;
 488
 489 #ifdef YYDEBUG
 490                 case 'Y':
 491                         {
 492                         /* Undocumented flag */
 493                         extern int yydebug;
 494                         yydebug = 1;
 495                         }
 496                         break;
 497 #endif
 498                 default:
 499                         usage();
 500                         /* NOTREACHED */
 501                 }
 502
 503         if (aflag && nflag)
 504                 error("-a and -n options are incompatible");
 505
 506         if (tflag > 0)
 507                 thiszone = gmt2local(0);
 508
 509         if (RFileName != NULL) {
 510                 /*
 511                  * We don't need network access, so set it back to the user id.
 512                  * Also, this prevents the user from reading anyone's
 513                  * trace file.
 514                  */
 515                 setuid(getuid());
 516
 517                 pd = pcap_open_offline(RFileName, ebuf);
 518                 if (pd == NULL)
 519                         error("%s", ebuf);
 520                 localnet = 0;
 521                 netmask = 0;
 522                 if (fflag != 0)
 523                         error("-f and -r options are incompatible");
 524         } else {
 525                 if (device == NULL) {
 526                         device = pcap_lookupdev(ebuf);
 527                         if (device == NULL)
 528                                 error("%s", ebuf);
 529                 }
 530                 *ebuf = '\0';
 531                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 532                 if (pd == NULL)
 533                         error("%s", ebuf);
 534                 else if (*ebuf)
 535                         warning("%s", ebuf);
 536                 if (Lflag) {
 537                         show_dlts_and_exit(pd);
 538                 }
 539                 if (dlt >= 0) {
 540                         if (pcap_set_datalink(pd, dlt) < 0)
 541                                 error("%s", pcap_geterr(pd));
 542                         (void)fprintf(stderr, "%s: data link type %s\n",
 543                                       program_name, dlt_name);
 544                         (void)fflush(stderr);
 545                 }
 546                 i = pcap_snapshot(pd);
 547                 if (snaplen < i) {
 548                         warning("snaplen raised from %d to %d", snaplen, i);
 549                         snaplen = i;
 550                 }
 551                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 552                         localnet = 0;
 553                         netmask = 0;
 554                         warning("%s", ebuf);
 555                 }
 556                 /*
 557                  * Let user own process after socket has been opened.
 558                  */
 559                 setuid(getuid());
 560         }
 561         if (infile)
 562                 cmdbuf = read_infile(infile);
 563         else
 564                 cmdbuf = copy_argv(&argv[optind]);
 565
 566         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 567                 error("%s", pcap_geterr(pd));
 568         if (dflag) {
 569                 bpf_dump(&fcode, dflag);
 570                 exit(0);
 571         }
 572         init_addrtoname(localnet, netmask);
 573
 574         (void)setsignal(SIGTERM, cleanup);
 575         (void)setsignal(SIGINT, cleanup);
 576         /* Cooperate with nohup(1) */
 577         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 578                 (void)setsignal(SIGHUP, oldhandler);
 579
 580         if (pcap_setfilter(pd, &fcode) < 0)
 581                 error("%s", pcap_geterr(pd));
 582         if (WFileName) {
 583                 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
 584                 if (p == NULL)
 585                         error("%s", pcap_geterr(pd));
 586                 if (Cflag != 0) {
 587                         printer = dump_and_trunc;
 588                         dumpinfo.WFileName = WFileName;
 589                         dumpinfo.pd = pd;
 590                         dumpinfo.p = p;
 591                         pcap_userdata = (u_char *)&dumpinfo;
 592                 } else {
 593                         printer = pcap_dump;
 594                         pcap_userdata = (u_char *)p;
 595                 }
 596         } else {
 597                 printer = lookup_printer(pcap_datalink(pd));
 598                 pcap_userdata = 0;
 599 #ifdef SIGINFO
 600                 (void)setsignal(SIGINFO, requestinfo);
 601 #endif
 602         }
 603         if (RFileName == NULL) {
 604                 (void)fprintf(stderr, "%s: listening on %s\n",
 605                     program_name, device);
 606                 (void)fflush(stderr);
 607         }
 608         if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {
 609                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 610                     program_name, pcap_geterr(pd));
 611                 exit(1);
 612         }
 613         if (RFileName == NULL)
 614                 info(1);
 615         pcap_close(pd);
 616         exit(0);
 617 }
 618
 619 /* make a clean exit on interrupts */
 620 static RETSIGTYPE
 621 cleanup(int signo)
 622 {
 623
 624         /* Can't print the summary if reading from a savefile */
 625         if (pd != NULL && pcap_file(pd) == NULL) {
 626                 (void)fflush(stdout);
 627                 putc('\n', stderr);
 628                 info(1);
 629         }
 630         exit(0);
 631 }
 632
 633 void
 634 info(register int verbose)
 635 {
 636         struct pcap_stat stat;
 637
 638         if (pcap_stats(pd, &stat) < 0) {
 639                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
 640                 return;
 641         }
 642         if (!verbose)
 643                 fprintf(stderr, "%s: ", program_name);
 644         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
 645         if (!verbose)
 646                 fputs(", ", stderr);
 647         else
 648                 putc('\n', stderr);
 649         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
 650         infoprint = 0;
 651 }
 652
 653 static void
 654 reverse(char *s)
 655 {
 656         int i, j, c;
 657
 658         for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
 659                 c = s[i];
 660                 s[i] = s[j];
 661                 s[j] = c;
 662         }
 663 }
 664
 665
 666 static void
 667 swebitoa(unsigned int n, char *s)
 668 {
 669         unsigned int i;
 670
 671         i = 0;
 672         do {
 673                 s[i++] = n % 10 + '0';
 674         } while ((n /= 10) > 0);
 675
 676         s[i] = '\0';
 677         reverse(s);
 678 }
 679
 680 static void
 681 dump_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 682 {
 683         struct dump_info *info;
 684         static uint cnt = 2;
 685         char *name;
 686
 687         info = (struct dump_info *)user;
 688
 689         /*
 690          * XXX - this won't prevent capture files from getting
 691          * larger than Cflag - the last packet written to the
 692          * file could put it over Cflag.
 693          */
 694         if (ftell((FILE *)info->p) > Cflag) {
 695                 name = (char *) malloc(strlen(info->WFileName) + 4);
 696                 if (name == NULL)
 697                         error("dump_and_trunc: malloc");
 698                 strcpy(name, info->WFileName);
 699                 swebitoa(cnt, name + strlen(info->WFileName));
 700                 cnt++;
 701                 pcap_dump_close(info->p);
 702                 info->p = pcap_dump_open(info->pd, name);
 703                 free(name);
 704                 if (info->p == NULL)
 705                         error("%s", pcap_geterr(pd));
 706         }
 707
 708         pcap_dump((u_char *)info->p, h, sp);
 709 }
 710
 711 /* Like default_print() but data need not be aligned */
 712 void
 713 default_print_unaligned(register const u_char *cp, register u_int length)
 714 {
 715         register u_int i, s;
 716         register int nshorts;
 717
 718         if (Xflag) {
 719                 ascii_print(cp, length);
 720                 return;
 721         }
 722         nshorts = (u_int) length / sizeof(u_short);
 723         i = 0;
 724         while (--nshorts >= 0) {
 725                 if ((i++ % 8) == 0)
 726                         (void)printf("\n\t\t\t");
 727                 s = *cp++;
 728                 (void)printf(" %02x%02x", s, *cp++);
 729         }
 730         if (length & 1) {
 731                 if ((i % 8) == 0)
 732                         (void)printf("\n\t\t\t");
 733                 (void)printf(" %02x", *cp);
 734         }
 735 }
 736
 737 /*
 738  * By default, print the packet out in hex.
 739  */
 740 void
 741 default_print(register const u_char *bp, register u_int length)
 742 {
 743         default_print_unaligned(bp, length);
 744 }
 745
 746 #ifdef SIGINFO
 747 RETSIGTYPE requestinfo(int signo)
 748 {
 749         if (infodelay)
 750                 ++infoprint;
 751         else
 752                 info(0);
 753 }
 754 #endif
 755
 756 static void
 757 usage(void)
 758 {
 759         extern char version[];
 760         extern char pcap_version[];
 761
 762         (void)fprintf(stderr, "%s version %s\n", program_name, version);
 763         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
 764         (void)fprintf(stderr,
 765 "Usage: %s [-adeflLnNOpqRStuvxX] [ -c count ] [ -C file_size ]\n", program_name);
 766         (void)fprintf(stderr,
 767 "\t\t[ -F file ] [ -i interface ] [ -r file ] [ -s snaplen ]\n");
 768         (void)fprintf(stderr,
 769 "\t\t[ -T type ] [ -w file ] [ -E algo:secret ] [ -y datalinktype ]\n");
 770         (void)fprintf(stderr,
 771 "\t\t[ expression ]\n");
 772         exit(1);
 773 }