The Tcpdump Group git mirrors - libpcap/blob - tests/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[] _U_ =
  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 /*
  29  * Tests how select() and poll() behave on the selectable file descriptor
  30  * for a pcap_t.
  31  *
  32  * This would be significantly different on Windows, as it'd test
  33  * how WaitForMultipleObjects() would work on the event handle for a
  34  * pcap_t.
  35  */
  36 #include <pcap.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <stdarg.h>
  41 #include <unistd.h>
  42 #include <errno.h>
  43 #include <sys/types.h>
  44 #include <sys/select.h>
  45 #include <poll.h>
  46
  47 char *program_name;
  48
  49 /* Forwards */
  50 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
  51 static void usage(void) __attribute__((noreturn));
  52 static void error(const char *, ...);
  53 static void warning(const char *, ...);
  54 static char *copy_argv(char **);
  55
  56 static pcap_t *pd;
  57
  58 int
  59 main(int argc, char **argv)
  60 {
  61         register int op;
  62         bpf_u_int32 localnet, netmask;
  63         register char *cp, *cmdbuf, *device;
  64         int doselect, dopoll, dotimeout, dononblock;
  65         struct bpf_program fcode;
  66         char ebuf[PCAP_ERRBUF_SIZE];
  67         int selectable_fd;
  68         int status;
  69         int packet_count;
  70
  71         device = NULL;
  72         doselect = 0;
  73         dopoll = 0;
  74         dotimeout = 0;
  75         dononblock = 0;
  76         if ((cp = strrchr(argv[0], '/')) != NULL)
  77                 program_name = cp + 1;
  78         else
  79                 program_name = argv[0];
  80
  81         opterr = 0;
  82         while ((op = getopt(argc, argv, "i:sptn")) != -1) {
  83                 switch (op) {
  84
  85                 case 'i':
  86                         device = optarg;
  87                         break;
  88
  89                 case 's':
  90                         doselect = 1;
  91                         break;
  92
  93                 case 'p':
  94                         dopoll = 1;
  95                         break;
  96
  97                 case 't':
  98                         dotimeout = 1;
  99                         break;
 100
 101                 case 'n':
 102                         dononblock = 1;
 103                         break;
 104
 105                 default:
 106                         usage();
 107                         /* NOTREACHED */
 108                 }
 109         }
 110
 111         if (doselect && dopoll) {
 112                 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
 113                 return 1;
 114         }
 115         if (dotimeout && !doselect && !dopoll) {
 116                 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
 117                 return 1;
 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_open_live(device, 65535, 0, 1000, ebuf);
 126         if (pd == NULL)
 127                 error("%s", ebuf);
 128         else if (*ebuf)
 129                 warning("%s", ebuf);
 130         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 131                 localnet = 0;
 132                 netmask = 0;
 133                 warning("%s", ebuf);
 134         }
 135         cmdbuf = copy_argv(&argv[optind]);
 136
 137         if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
 138                 error("%s", pcap_geterr(pd));
 139
 140         if (pcap_setfilter(pd, &fcode) < 0)
 141                 error("%s", pcap_geterr(pd));
 142         if (pcap_get_selectable_fd(pd) == -1)
 143                 error("pcap_get_selectable_fd() fails");
 144         if (dononblock) {
 145                 if (pcap_setnonblock(pd, 1, ebuf) == -1)
 146                         error("pcap_setnonblock failed: %s", ebuf);
 147         }
 148         selectable_fd = pcap_get_selectable_fd(pd);
 149         printf("Listening on %s\n", device);
 150         if (doselect) {
 151                 for (;;) {
 152                         fd_set setread, setexcept;
 153                         struct timeval seltimeout;
 154
 155                         FD_ZERO(&setread);
 156                         FD_SET(selectable_fd, &setread);
 157                         FD_ZERO(&setexcept);
 158                         FD_SET(selectable_fd, &setexcept);
 159                         if (dotimeout) {
 160                                 seltimeout.tv_sec = 0;
 161                                 seltimeout.tv_usec = 1000;
 162                                 status = select(selectable_fd + 1, &setread,
 163                                     NULL, &setexcept, &seltimeout);
 164                         } else {
 165                                 status = select(selectable_fd + 1, &setread,
 166                                     NULL, &setexcept, NULL);
 167                         }
 168                         if (status == -1) {
 169                                 printf("Select returns error (%s)\n",
 170                                     strerror(errno));
 171                         } else {
 172                                 if (status == 0)
 173                                         printf("Select timed out: ");
 174                                 else
 175                                         printf("Select returned a descriptor: ");
 176                                 if (FD_ISSET(selectable_fd, &setread))
 177                                         printf("readable, ");
 178                                 else
 179                                         printf("not readable, ");
 180                                 if (FD_ISSET(selectable_fd, &setexcept))
 181                                         printf("exceptional condition\n");
 182                                 else
 183                                         printf("no exceptional condition\n");
 184                                 packet_count = 0;
 185                                 status = pcap_dispatch(pd, -1, countme,
 186                                     (u_char *)&packet_count);
 187                                 if (status < 0)
 188                                         break;
 189                                 printf("%d packets seen, %d packets counted after select returns\n",
 190                                     status, packet_count);
 191                         }
 192                 }
 193         } else if (dopoll) {
 194                 for (;;) {
 195                         struct pollfd fd;
 196                         int polltimeout;
 197
 198                         fd.fd = selectable_fd;
 199                         fd.events = POLLIN;
 200                         if (dotimeout)
 201                                 polltimeout = 1;
 202                         else
 203                                 polltimeout = -1;
 204                         status = poll(&fd, 1, polltimeout);
 205                         if (status == -1) {
 206                                 printf("Poll returns error (%s)\n",
 207                                     strerror(errno));
 208                         } else {
 209                                 if (status == 0)
 210                                         printf("Poll timed out\n");
 211                                 else {
 212                                         printf("Poll returned a descriptor: ");
 213                                         if (fd.revents & POLLIN)
 214                                                 printf("readable, ");
 215                                         else
 216                                                 printf("not readable, ");
 217                                         if (fd.revents & POLLERR)
 218                                                 printf("exceptional condition, ");
 219                                         else
 220                                                 printf("no exceptional condition, ");
 221                                         if (fd.revents & POLLHUP)
 222                                                 printf("disconnect, ");
 223                                         else
 224                                                 printf("no disconnect, ");
 225                                         if (fd.revents & POLLNVAL)
 226                                                 printf("invalid\n");
 227                                         else
 228                                                 printf("not invalid\n");
 229                                 }
 230                                 packet_count = 0;
 231                                 status = pcap_dispatch(pd, -1, countme,
 232                                     (u_char *)&packet_count);
 233                                 if (status < 0)
 234                                         break;
 235                                 printf("%d packets seen, %d packets counted after poll returns\n",
 236                                     status, packet_count);
 237                         }
 238                 }
 239         } else {
 240                 for (;;) {
 241                         packet_count = 0;
 242                         status = pcap_dispatch(pd, -1, countme,
 243                             (u_char *)&packet_count);
 244                         if (status < 0)
 245                                 break;
 246                         printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
 247                             status, packet_count);
 248                 }
 249         }
 250         if (status == -2) {
 251                 /*
 252                  * We got interrupted, so perhaps we didn't
 253                  * manage to finish a line we were printing.
 254                  * Print an extra newline, just in case.
 255                  */
 256                 putchar('\n');
 257         }
 258         (void)fflush(stdout);
 259         if (status == -1) {
 260                 /*
 261                  * Error.  Report it.
 262                  */
 263                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 264                     program_name, pcap_geterr(pd));
 265         }
 266         pcap_close(pd);
 267         exit(status == -1 ? 1 : 0);
 268 }
 269
 270 static void
 271 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 272 {
 273         int *counterp = (int *)user;
 274
 275         (*counterp)++;
 276 }
 277
 278 static void
 279 usage(void)
 280 {
 281         (void)fprintf(stderr, "Usage: %s [ -sptn ] [ -i interface ] [expression]\n",
 282             program_name);
 283         exit(1);
 284 }
 285
 286 /* VARARGS */
 287 static void
 288 error(const char *fmt, ...)
 289 {
 290         va_list ap;
 291
 292         (void)fprintf(stderr, "%s: ", program_name);
 293         va_start(ap, fmt);
 294         (void)vfprintf(stderr, fmt, ap);
 295         va_end(ap);
 296         if (*fmt) {
 297                 fmt += strlen(fmt);
 298                 if (fmt[-1] != '\n')
 299                         (void)fputc('\n', stderr);
 300         }
 301         exit(1);
 302         /* NOTREACHED */
 303 }
 304
 305 /* VARARGS */
 306 static void
 307 warning(const char *fmt, ...)
 308 {
 309         va_list ap;
 310
 311         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 312         va_start(ap, fmt);
 313         (void)vfprintf(stderr, fmt, ap);
 314         va_end(ap);
 315         if (*fmt) {
 316                 fmt += strlen(fmt);
 317                 if (fmt[-1] != '\n')
 318                         (void)fputc('\n', stderr);
 319         }
 320 }
 321
 322 /*
 323  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 324  */
 325 static char *
 326 copy_argv(register char **argv)
 327 {
 328         register char **p;
 329         register u_int len = 0;
 330         char *buf;
 331         char *src, *dst;
 332
 333         p = argv;
 334         if (*p == 0)
 335                 return 0;
 336
 337         while (*p)
 338                 len += strlen(*p++) + 1;
 339
 340         buf = (char *)malloc(len);
 341         if (buf == NULL)
 342                 error("copy_argv: malloc");
 343
 344         p = argv;
 345         dst = buf;
 346         while ((src = *p++) != NULL) {
 347                 while ((*dst++ = *src++) != '\0')
 348                         ;
 349                 dst[-1] = ' ';
 350         }
 351         dst[-1] = '\0';
 352
 353         return buf;
 354 }