The Tcpdump Group git mirrors - libpcap/blob - tests/capturetest.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
  22 #ifndef lint
  23 static const char copyright[] =
  24     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  25 The Regents of the University of California.  All rights reserved.\n";
  26 #endif
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <stdarg.h>
  32 #include <limits.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include <sys/types.h>
  36 #include <sys/select.h>
  37 #include <poll.h>
  38
  39 #include <pcap.h>
  40
  41 static char *program_name;
  42
  43 /* Forwards */
  44 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
  45 static void usage(void) __attribute__((noreturn));
  46 static void error(const char *, ...);
  47 static void warning(const char *, ...);
  48 static char *copy_argv(char **);
  49
  50 static pcap_t *pd;
  51
  52 extern int optind;
  53 extern int opterr;
  54 extern char *optarg;
  55
  56 int
  57 main(int argc, char **argv)
  58 {
  59         register int op;
  60         register char *cp, *cmdbuf, *device;
  61         long longarg;
  62         char *p;
  63         int timeout = 1000;
  64         int immediate = 0;
  65         int nonblock = 0;
  66         bpf_u_int32 localnet, netmask;
  67         struct bpf_program fcode;
  68         char ebuf[PCAP_ERRBUF_SIZE];
  69         int status;
  70         int packet_count;
  71
  72         device = NULL;
  73         if ((cp = strrchr(argv[0], '/')) != NULL)
  74                 program_name = cp + 1;
  75         else
  76                 program_name = argv[0];
  77
  78         opterr = 0;
  79         while ((op = getopt(argc, argv, "i:mnt:")) != -1) {
  80                 switch (op) {
  81
  82                 case 'i':
  83                         device = optarg;
  84                         break;
  85
  86                 case 'm':
  87                         immediate = 1;
  88                         break;
  89
  90                 case 'n':
  91                         nonblock = 1;
  92                         break;
  93
  94                 case 't':
  95                         longarg = strtol(optarg, &p, 10);
  96                         if (p == optarg || *p != '\0') {
  97                                 error("Timeout value \"%s\" is not a number",
  98                                     optarg);
  99                                 /* NOTREACHED */
 100                         }
 101                         if (longarg < 0) {
 102                                 error("Timeout value %ld is negative", longarg);
 103                                 /* NOTREACHED */
 104                         }
 105                         if (longarg > INT_MAX) {
 106                                 error("Timeout value %ld is too large (> %d)",
 107                                     longarg, INT_MAX);
 108                                 /* NOTREACHED */
 109                         }
 110                         timeout = (int)longarg;
 111                         break;
 112
 113                 default:
 114                         usage();
 115                         /* NOTREACHED */
 116                 }
 117         }
 118
 119         if (device == NULL) {
 120                 device = pcap_lookupdev(ebuf);
 121                 if (device == NULL)
 122                         error("%s", ebuf);
 123         }
 124         *ebuf = '\0';
 125         pd = pcap_create(device, ebuf);
 126         if (pd == NULL)
 127                 error("%s", ebuf);
 128         status = pcap_set_snaplen(pd, 65535);
 129         if (status != 0)
 130                 error("%s: pcap_set_snaplen failed: %s",
 131                             device, pcap_statustostr(status));
 132         if (immediate) {
 133                 status = pcap_set_immediate_mode(pd, 1);
 134                 if (status != 0)
 135                         error("%s: pcap_set_immediate_mode failed: %s",
 136                             device, pcap_statustostr(status));
 137         }
 138         status = pcap_set_timeout(pd, timeout);
 139         if (status != 0)
 140                 error("%s: pcap_set_timeout failed: %s",
 141                     device, pcap_statustostr(status));
 142         status = pcap_activate(pd);
 143         if (status < 0) {
 144                 /*
 145                  * pcap_activate() failed.
 146                  */
 147                 error("%s: %s\n(%s)", device,
 148                     pcap_statustostr(status), pcap_geterr(pd));
 149         } else if (status > 0) {
 150                 /*
 151                  * pcap_activate() succeeded, but it's warning us
 152                  * of a problem it had.
 153                  */
 154                 warning("%s: %s\n(%s)", device,
 155                     pcap_statustostr(status), pcap_geterr(pd));
 156         }
 157         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 158                 localnet = 0;
 159                 netmask = 0;
 160                 warning("%s", ebuf);
 161         }
 162         cmdbuf = copy_argv(&argv[optind]);
 163
 164         if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
 165                 error("%s", pcap_geterr(pd));
 166
 167         if (pcap_setfilter(pd, &fcode) < 0)
 168                 error("%s", pcap_geterr(pd));
 169         if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
 170                 error("pcap_setnonblock failed: %s", ebuf);
 171         printf("Listening on %s\n", device);
 172         for (;;) {
 173                 packet_count = 0;
 174                 status = pcap_dispatch(pd, -1, countme,
 175                     (u_char *)&packet_count);
 176                 if (status < 0)
 177                         break;
 178                 if (status != 0) {
 179                         printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
 180                             status, packet_count);
 181                 }
 182         }
 183         if (status == -2) {
 184                 /*
 185                  * We got interrupted, so perhaps we didn't
 186                  * manage to finish a line we were printing.
 187                  * Print an extra newline, just in case.
 188                  */
 189                 putchar('\n');
 190         }
 191         (void)fflush(stdout);
 192         if (status == -1) {
 193                 /*
 194                  * Error.  Report it.
 195                  */
 196                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 197                     program_name, pcap_geterr(pd));
 198         }
 199         pcap_close(pd);
 200         exit(status == -1 ? 1 : 0);
 201 }
 202
 203 static void
 204 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 205 {
 206         int *counterp = (int *)user;
 207
 208         (*counterp)++;
 209 }
 210
 211 static void
 212 usage(void)
 213 {
 214         (void)fprintf(stderr, "Usage: %s [ -mn ] [ -i interface ] [ -t timeout] [expression]\n",
 215             program_name);
 216         exit(1);
 217 }
 218
 219 /* VARARGS */
 220 static void
 221 error(const char *fmt, ...)
 222 {
 223         va_list ap;
 224
 225         (void)fprintf(stderr, "%s: ", program_name);
 226         va_start(ap, fmt);
 227         (void)vfprintf(stderr, fmt, ap);
 228         va_end(ap);
 229         if (*fmt) {
 230                 fmt += strlen(fmt);
 231                 if (fmt[-1] != '\n')
 232                         (void)fputc('\n', stderr);
 233         }
 234         exit(1);
 235         /* NOTREACHED */
 236 }
 237
 238 /* VARARGS */
 239 static void
 240 warning(const char *fmt, ...)
 241 {
 242         va_list ap;
 243
 244         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 245         va_start(ap, fmt);
 246         (void)vfprintf(stderr, fmt, ap);
 247         va_end(ap);
 248         if (*fmt) {
 249                 fmt += strlen(fmt);
 250                 if (fmt[-1] != '\n')
 251                         (void)fputc('\n', stderr);
 252         }
 253 }
 254
 255 /*
 256  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 257  */
 258 static char *
 259 copy_argv(register char **argv)
 260 {
 261         register char **p;
 262         register u_int len = 0;
 263         char *buf;
 264         char *src, *dst;
 265
 266         p = argv;
 267         if (*p == 0)
 268                 return 0;
 269
 270         while (*p)
 271                 len += strlen(*p++) + 1;
 272
 273         buf = (char *)malloc(len);
 274         if (buf == NULL)
 275                 error("copy_argv: malloc");
 276
 277         p = argv;
 278         dst = buf;
 279         while ((src = *p++) != NULL) {
 280                 while ((*dst++ = *src++) != '\0')
 281                         ;
 282                 dst[-1] = ' ';
 283         }
 284         dst[-1] = '\0';
 285
 286         return buf;
 287 }