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 #ifdef HAVE_SYS_SELECT_H
  45 #include <sys/select.h>
  46 #else
  47 #include <sys/time.h>   /* older UN*Xes */
  48 #endif
  49 #include <poll.h>
  50
  51 char *program_name;
  52
  53 /*
  54  * This was introduced by Clang:
  55  *
  56  *     http://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
  57  *
  58  * in some version (which version?); it has been picked up by GCC 5.0.
  59  */
  60 #ifndef __has_attribute
  61   /*
  62    * It's a macro, so you can check whether it's defined to check
  63    * whether it's supported.
  64    *
  65    * If it's not, define it to always return 0, so that we move on to
  66    * the fallback checks.
  67    */
  68   #define __has_attribute(x) 0
  69 #endif
  70
  71 #if __has_attribute(noreturn) \
  72     || (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 205)) \
  73     || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590)) \
  74     || (defined(__xlC__) && __xlC__ >= 0x0A01) \
  75     || (defined(__HP_aCC) && __HP_aCC >= 61000)
  76   /*
  77    * Compiler with support for it, or GCC 2.5 and later, or Solaris Studio 12
  78    * (Sun C 5.9) and later, or IBM XL C 10.1 and later (do any earlier
  79    * versions of XL C support this?), or HP aCC A.06.10 and later.
  80    */
  81   #define PCAP_NORETURN __attribute((noreturn))
  82 #elif defined( _MSC_VER )
  83   #define PCAP_NORETURN __declspec(noreturn)
  84 #else
  85   #define PCAP_NORETURN
  86 #endif
  87
  88 #if __has_attribute(__format__) \
  89     || (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 203)) \
  90     || (defined(__xlC__) && __xlC__ >= 0x0A01) \
  91     || (defined(__HP_aCC) && __HP_aCC >= 61000)
  92   /*
  93    * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1
  94    * and later (do any earlier versions of XL C support this?),
  95    * or HP aCC A.06.10 and later.
  96    */
  97   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
  98 #else
  99   #define PCAP_PRINTFLIKE(x,y)
 100 #endif
 101
 102 /* Forwards */
 103 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
 104 static void PCAP_NORETURN usage(void);
 105 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
 106 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
 107 static char *copy_argv(char **);
 108
 109 static pcap_t *pd;
 110
 111 int
 112 main(int argc, char **argv)
 113 {
 114         register int op;
 115         bpf_u_int32 localnet, netmask;
 116         register char *cp, *cmdbuf, *device;
 117         int doselect, dopoll, dotimeout, dononblock;
 118         struct bpf_program fcode;
 119         char ebuf[PCAP_ERRBUF_SIZE];
 120         int selectable_fd;
 121         int status;
 122         int packet_count;
 123
 124         device = NULL;
 125         doselect = 0;
 126         dopoll = 0;
 127         dotimeout = 0;
 128         dononblock = 0;
 129         if ((cp = strrchr(argv[0], '/')) != NULL)
 130                 program_name = cp + 1;
 131         else
 132                 program_name = argv[0];
 133
 134         opterr = 0;
 135         while ((op = getopt(argc, argv, "i:sptn")) != -1) {
 136                 switch (op) {
 137
 138                 case 'i':
 139                         device = optarg;
 140                         break;
 141
 142                 case 's':
 143                         doselect = 1;
 144                         break;
 145
 146                 case 'p':
 147                         dopoll = 1;
 148                         break;
 149
 150                 case 't':
 151                         dotimeout = 1;
 152                         break;
 153
 154                 case 'n':
 155                         dononblock = 1;
 156                         break;
 157
 158                 default:
 159                         usage();
 160                         /* NOTREACHED */
 161                 }
 162         }
 163
 164         if (doselect && dopoll) {
 165                 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
 166                 return 1;
 167         }
 168         if (dotimeout && !doselect && !dopoll) {
 169                 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
 170                 return 1;
 171         }
 172         if (device == NULL) {
 173                 device = pcap_lookupdev(ebuf);
 174                 if (device == NULL)
 175                         error("%s", ebuf);
 176         }
 177         *ebuf = '\0';
 178         pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
 179         if (pd == NULL)
 180                 error("%s", ebuf);
 181         else if (*ebuf)
 182                 warning("%s", ebuf);
 183         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 184                 localnet = 0;
 185                 netmask = 0;
 186                 warning("%s", ebuf);
 187         }
 188         cmdbuf = copy_argv(&argv[optind]);
 189
 190         if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
 191                 error("%s", pcap_geterr(pd));
 192
 193         if (pcap_setfilter(pd, &fcode) < 0)
 194                 error("%s", pcap_geterr(pd));
 195         if (pcap_get_selectable_fd(pd) == -1)
 196                 error("pcap_get_selectable_fd() fails");
 197         if (dononblock) {
 198                 if (pcap_setnonblock(pd, 1, ebuf) == -1)
 199                         error("pcap_setnonblock failed: %s", ebuf);
 200         }
 201         selectable_fd = pcap_get_selectable_fd(pd);
 202         printf("Listening on %s\n", device);
 203         if (doselect) {
 204                 for (;;) {
 205                         fd_set setread, setexcept;
 206                         struct timeval seltimeout;
 207
 208                         FD_ZERO(&setread);
 209                         FD_SET(selectable_fd, &setread);
 210                         FD_ZERO(&setexcept);
 211                         FD_SET(selectable_fd, &setexcept);
 212                         if (dotimeout) {
 213                                 seltimeout.tv_sec = 0;
 214                                 seltimeout.tv_usec = 1000;
 215                                 status = select(selectable_fd + 1, &setread,
 216                                     NULL, &setexcept, &seltimeout);
 217                         } else {
 218                                 status = select(selectable_fd + 1, &setread,
 219                                     NULL, &setexcept, NULL);
 220                         }
 221                         if (status == -1) {
 222                                 printf("Select returns error (%s)\n",
 223                                     strerror(errno));
 224                         } else {
 225                                 if (status == 0)
 226                                         printf("Select timed out: ");
 227                                 else
 228                                         printf("Select returned a descriptor: ");
 229                                 if (FD_ISSET(selectable_fd, &setread))
 230                                         printf("readable, ");
 231                                 else
 232                                         printf("not readable, ");
 233                                 if (FD_ISSET(selectable_fd, &setexcept))
 234                                         printf("exceptional condition\n");
 235                                 else
 236                                         printf("no exceptional condition\n");
 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 select returns\n",
 243                                     status, packet_count);
 244                         }
 245                 }
 246         } else if (dopoll) {
 247                 for (;;) {
 248                         struct pollfd fd;
 249                         int polltimeout;
 250
 251                         fd.fd = selectable_fd;
 252                         fd.events = POLLIN;
 253                         if (dotimeout)
 254                                 polltimeout = 1;
 255                         else
 256                                 polltimeout = -1;
 257                         status = poll(&fd, 1, polltimeout);
 258                         if (status == -1) {
 259                                 printf("Poll returns error (%s)\n",
 260                                     strerror(errno));
 261                         } else {
 262                                 if (status == 0)
 263                                         printf("Poll timed out\n");
 264                                 else {
 265                                         printf("Poll returned a descriptor: ");
 266                                         if (fd.revents & POLLIN)
 267                                                 printf("readable, ");
 268                                         else
 269                                                 printf("not readable, ");
 270                                         if (fd.revents & POLLERR)
 271                                                 printf("exceptional condition, ");
 272                                         else
 273                                                 printf("no exceptional condition, ");
 274                                         if (fd.revents & POLLHUP)
 275                                                 printf("disconnect, ");
 276                                         else
 277                                                 printf("no disconnect, ");
 278                                         if (fd.revents & POLLNVAL)
 279                                                 printf("invalid\n");
 280                                         else
 281                                                 printf("not invalid\n");
 282                                 }
 283                                 packet_count = 0;
 284                                 status = pcap_dispatch(pd, -1, countme,
 285                                     (u_char *)&packet_count);
 286                                 if (status < 0)
 287                                         break;
 288                                 printf("%d packets seen, %d packets counted after poll returns\n",
 289                                     status, packet_count);
 290                         }
 291                 }
 292         } else {
 293                 for (;;) {
 294                         packet_count = 0;
 295                         status = pcap_dispatch(pd, -1, countme,
 296                             (u_char *)&packet_count);
 297                         if (status < 0)
 298                                 break;
 299                         printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
 300                             status, packet_count);
 301                 }
 302         }
 303         if (status == -2) {
 304                 /*
 305                  * We got interrupted, so perhaps we didn't
 306                  * manage to finish a line we were printing.
 307                  * Print an extra newline, just in case.
 308                  */
 309                 putchar('\n');
 310         }
 311         (void)fflush(stdout);
 312         if (status == -1) {
 313                 /*
 314                  * Error.  Report it.
 315                  */
 316                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 317                     program_name, pcap_geterr(pd));
 318         }
 319         pcap_close(pd);
 320         exit(status == -1 ? 1 : 0);
 321 }
 322
 323 static void
 324 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 325 {
 326         int *counterp = (int *)user;
 327
 328         (*counterp)++;
 329 }
 330
 331 static void
 332 usage(void)
 333 {
 334         (void)fprintf(stderr, "Usage: %s [ -sptn ] [ -i interface ] [expression]\n",
 335             program_name);
 336         exit(1);
 337 }
 338
 339 /* VARARGS */
 340 static void
 341 error(const char *fmt, ...)
 342 {
 343         va_list ap;
 344
 345         (void)fprintf(stderr, "%s: ", program_name);
 346         va_start(ap, fmt);
 347         (void)vfprintf(stderr, fmt, ap);
 348         va_end(ap);
 349         if (*fmt) {
 350                 fmt += strlen(fmt);
 351                 if (fmt[-1] != '\n')
 352                         (void)fputc('\n', stderr);
 353         }
 354         exit(1);
 355         /* NOTREACHED */
 356 }
 357
 358 /* VARARGS */
 359 static void
 360 warning(const char *fmt, ...)
 361 {
 362         va_list ap;
 363
 364         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 365         va_start(ap, fmt);
 366         (void)vfprintf(stderr, fmt, ap);
 367         va_end(ap);
 368         if (*fmt) {
 369                 fmt += strlen(fmt);
 370                 if (fmt[-1] != '\n')
 371                         (void)fputc('\n', stderr);
 372         }
 373 }
 374
 375 /*
 376  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 377  */
 378 static char *
 379 copy_argv(register char **argv)
 380 {
 381         register char **p;
 382         register u_int len = 0;
 383         char *buf;
 384         char *src, *dst;
 385
 386         p = argv;
 387         if (*p == 0)
 388                 return 0;
 389
 390         while (*p)
 391                 len += strlen(*p++) + 1;
 392
 393         buf = (char *)malloc(len);
 394         if (buf == NULL)
 395                 error("copy_argv: malloc");
 396
 397         p = argv;
 398         dst = buf;
 399         while ((src = *p++) != NULL) {
 400                 while ((*dst++ = *src++) != '\0')
 401                         ;
 402                 dst[-1] = ' ';
 403         }
 404         dst[-1] = '\0';
 405
 406         return buf;
 407 }