The Tcpdump Group git mirrors - libpcap/blob - selpolltest.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 <pcap.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdarg.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 char *program_name;
  40
  41 /* Forwards */
  42 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
  43 static void usage(void) __attribute__((noreturn));
  44 static void error(const char *, ...);
  45 static void warning(const char *, ...);
  46 static char *copy_argv(char **);
  47
  48 static pcap_t *pd;
  49
  50 extern int optind;
  51 extern int opterr;
  52 extern char *optarg;
  53
  54 int
  55 main(int argc, char **argv)
  56 {
  57         register int op;
  58         bpf_u_int32 localnet, netmask;
  59         register char *cp, *cmdbuf, *device;
  60         int doselect, dopoll, dotimeout, dononblock;
  61         struct bpf_program fcode;
  62         char ebuf[PCAP_ERRBUF_SIZE];
  63         int selectable_fd;
  64         int status;
  65         int packet_count;
  66
  67         device = NULL;
  68         doselect = 0;
  69         dopoll = 0;
  70         dotimeout = 0;
  71         dononblock = 0;
  72         if ((cp = strrchr(argv[0], '/')) != NULL)
  73                 program_name = cp + 1;
  74         else
  75                 program_name = argv[0];
  76
  77         opterr = 0;
  78         while ((op = getopt(argc, argv, "i:sptn")) != -1) {
  79                 switch (op) {
  80
  81                 case 'i':
  82                         device = optarg;
  83                         break;
  84
  85                 case 's':
  86                         doselect = 1;
  87                         break;
  88
  89                 case 'p':
  90                         dopoll = 1;
  91                         break;
  92
  93                 case 't':
  94                         dotimeout = 1;
  95                         break;
  96
  97                 case 'n':
  98                         dononblock = 1;
  99                         break;
 100
 101                 default:
 102                         usage();
 103                         /* NOTREACHED */
 104                 }
 105         }
 106
 107         if (doselect && dopoll) {
 108                 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
 109                 return 1;
 110         }
 111         if (dotimeout && !doselect && !dopoll) {
 112                 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
 113                 return 1;
 114         }
 115         if (device == NULL) {
 116                 device = pcap_lookupdev(ebuf);
 117                 if (device == NULL)
 118                         error("%s", ebuf);
 119         }
 120         *ebuf = '\0';
 121         pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
 122         if (pd == NULL)
 123                 error("%s", ebuf);
 124         else if (*ebuf)
 125                 warning("%s", ebuf);
 126         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 127                 localnet = 0;
 128                 netmask = 0;
 129                 warning("%s", ebuf);
 130         }
 131         cmdbuf = copy_argv(&argv[optind]);
 132
 133         if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
 134                 error("%s", pcap_geterr(pd));
 135
 136         if (pcap_setfilter(pd, &fcode) < 0)
 137                 error("%s", pcap_geterr(pd));
 138         if (pcap_get_selectable_fd(pd) == -1)
 139                 error("pcap_get_selectable_fd() fails");
 140         if (dononblock) {
 141                 if (pcap_setnonblock(pd, 1, ebuf) == -1)
 142                         error("pcap_setnonblock failed: %s", ebuf);
 143         }
 144         selectable_fd = pcap_get_selectable_fd(pd);
 145         printf("Listening on %s\n", device);
 146         if (doselect) {
 147                 for (;;) {
 148                         fd_set setread, setexcept;
 149                         struct timeval seltimeout;
 150
 151                         FD_ZERO(&setread);
 152                         FD_SET(selectable_fd, &setread);
 153                         FD_ZERO(&setexcept);
 154                         FD_SET(selectable_fd, &setexcept);
 155                         if (dotimeout) {
 156                                 seltimeout.tv_sec = 0;
 157                                 seltimeout.tv_usec = 1000;
 158                                 status = select(selectable_fd + 1, &setread,
 159                                     NULL, &setexcept, &seltimeout);
 160                         } else {
 161                                 status = select(selectable_fd + 1, &setread,
 162                                     NULL, &setexcept, NULL);
 163                         }
 164                         if (status == -1) {
 165                                 printf("Select returns error (%s)\n",
 166                                     strerror(errno));
 167                         } else {
 168                                 if (status == 0)
 169                                         printf("Select timed out: ");
 170                                 else
 171                                         printf("Select returned a descriptor: ");
 172                                 if (FD_ISSET(selectable_fd, &setread))
 173                                         printf("readable, ");
 174                                 else
 175                                         printf("not readable, ");
 176                                 if (FD_ISSET(selectable_fd, &setexcept))
 177                                         printf("exceptional condition\n");
 178                                 else
 179                                         printf("no exceptional condition\n");
 180                                 packet_count = 0;
 181                                 status = pcap_dispatch(pd, -1, countme,
 182                                     (u_char *)&packet_count);
 183                                 if (status < 0)
 184                                         break;
 185                                 printf("%d packets seen, %d packets counted after select returns\n",
 186                                     status, packet_count);
 187                         }
 188                 }
 189         } else if (dopoll) {
 190                 for (;;) {
 191                         struct pollfd fd;
 192                         int polltimeout;
 193
 194                         fd.fd = selectable_fd;
 195                         fd.events = POLLIN;
 196                         if (dotimeout)
 197                                 polltimeout = 1;
 198                         else
 199                                 polltimeout = -1;
 200                         status = poll(&fd, 1, polltimeout);
 201                         if (status == -1) {
 202                                 printf("Poll returns error (%s)\n",
 203                                     strerror(errno));
 204                         } else {
 205                                 if (status == 0)
 206                                         printf("Poll timed out\n");
 207                                 else {
 208                                         printf("Poll returned a descriptor: ");
 209                                         if (fd.revents & POLLIN)
 210                                                 printf("readable, ");
 211                                         else
 212                                                 printf("not readable, ");
 213                                         if (fd.revents & POLLERR)
 214                                                 printf("exceptional condition, ");
 215                                         else
 216                                                 printf("no exceptional condition, ");
 217                                         if (fd.revents & POLLHUP)
 218                                                 printf("disconnect, ");
 219                                         else
 220                                                 printf("no disconnect, ");
 221                                         if (fd.revents & POLLNVAL)
 222                                                 printf("invalid\n");
 223                                         else
 224                                                 printf("not invalid\n");
 225                                 }
 226                                 packet_count = 0;
 227                                 status = pcap_dispatch(pd, -1, countme,
 228                                     (u_char *)&packet_count);
 229                                 if (status < 0)
 230                                         break;
 231                                 printf("%d packets seen, %d packets counted after poll returns\n",
 232                                     status, packet_count);
 233                         }
 234                 }
 235         } else {
 236                 for (;;) {
 237                         packet_count = 0;
 238                         status = pcap_dispatch(pd, -1, countme,
 239                             (u_char *)&packet_count);
 240                         if (status < 0)
 241                                 break;
 242                         printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
 243                             status, packet_count);
 244                 }
 245         }
 246         if (status == -2) {
 247                 /*
 248                  * We got interrupted, so perhaps we didn't
 249                  * manage to finish a line we were printing.
 250                  * Print an extra newline, just in case.
 251                  */
 252                 putchar('\n');
 253         }
 254         (void)fflush(stdout);
 255         if (status == -1) {
 256                 /*
 257                  * Error.  Report it.
 258                  */
 259                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 260                     program_name, pcap_geterr(pd));
 261         }
 262         pcap_close(pd);
 263         exit(status == -1 ? 1 : 0);
 264 }
 265
 266 static void
 267 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 268 {
 269         int *counterp = (int *)user;
 270
 271         (*counterp)++;
 272 }
 273
 274 static void
 275 usage(void)
 276 {
 277         (void)fprintf(stderr, "Usage: %s [ -sptn ] [ -i interface ] [expression]\n",
 278             program_name);
 279         exit(1);
 280 }
 281
 282 /* VARARGS */
 283 static void
 284 error(const char *fmt, ...)
 285 {
 286         va_list ap;
 287
 288         (void)fprintf(stderr, "%s: ", program_name);
 289         va_start(ap, fmt);
 290         (void)vfprintf(stderr, fmt, ap);
 291         va_end(ap);
 292         if (*fmt) {
 293                 fmt += strlen(fmt);
 294                 if (fmt[-1] != '\n')
 295                         (void)fputc('\n', stderr);
 296         }
 297         exit(1);
 298         /* NOTREACHED */
 299 }
 300
 301 /* VARARGS */
 302 static void
 303 warning(const char *fmt, ...)
 304 {
 305         va_list ap;
 306
 307         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 308         va_start(ap, fmt);
 309         (void)vfprintf(stderr, fmt, ap);
 310         va_end(ap);
 311         if (*fmt) {
 312                 fmt += strlen(fmt);
 313                 if (fmt[-1] != '\n')
 314                         (void)fputc('\n', stderr);
 315         }
 316 }
 317
 318 /*
 319  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 320  */
 321 static char *
 322 copy_argv(register char **argv)
 323 {
 324         register char **p;
 325         register u_int len = 0;
 326         char *buf;
 327         char *src, *dst;
 328
 329         p = argv;
 330         if (*p == 0)
 331                 return 0;
 332
 333         while (*p)
 334                 len += strlen(*p++) + 1;
 335
 336         buf = (char *)malloc(len);
 337         if (buf == NULL)
 338                 error("copy_argv: malloc");
 339
 340         p = argv;
 341         dst = buf;
 342         while ((src = *p++) != NULL) {
 343                 while ((*dst++ = *src++) != '\0')
 344                         ;
 345                 dst[-1] = ' ';
 346         }
 347         dst[-1] = '\0';
 348
 349         return buf;
 350 }