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 #include "varattrs.h"
  23
  24 #ifndef lint
  25 static const char copyright[] _U_ =
  26     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  27 The Regents of the University of California.  All rights reserved.\n";
  28 #endif
  29
  30 /*
  31  * Tests how select() and poll() behave on the selectable file descriptor
  32  * for a pcap_t.
  33  *
  34  * This would be significantly different on Windows, as it'd test
  35  * how WaitForMultipleObjects() would work on the event handle for a
  36  * pcap_t.
  37  */
  38 #include <pcap.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <stdarg.h>
  43 #include <unistd.h>
  44 #include <errno.h>
  45 #include <sys/types.h>
  46 #ifdef HAVE_SYS_SELECT_H
  47 #include <sys/select.h>
  48 #else
  49 #include <sys/time.h>   /* older UN*Xes */
  50 #endif
  51 #include <poll.h>
  52
  53 #include "pcap/funcattrs.h"
  54
  55 char *program_name;
  56
  57 /* Forwards */
  58 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
  59 static void PCAP_NORETURN usage(void);
  60 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
  61 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
  62 static char *copy_argv(char **);
  63
  64 static pcap_t *pd;
  65
  66 int
  67 main(int argc, char **argv)
  68 {
  69         register int op;
  70         bpf_u_int32 localnet, netmask;
  71         register char *cp, *cmdbuf, *device;
  72         int doselect, dopoll, dotimeout, dononblock;
  73         struct bpf_program fcode;
  74         char ebuf[PCAP_ERRBUF_SIZE];
  75         pcap_if_t *devlist;
  76         int selectable_fd;
  77         int status;
  78         int packet_count;
  79
  80         device = NULL;
  81         doselect = 0;
  82         dopoll = 0;
  83         dotimeout = 0;
  84         dononblock = 0;
  85         if ((cp = strrchr(argv[0], '/')) != NULL)
  86                 program_name = cp + 1;
  87         else
  88                 program_name = argv[0];
  89
  90         opterr = 0;
  91         while ((op = getopt(argc, argv, "i:sptn")) != -1) {
  92                 switch (op) {
  93
  94                 case 'i':
  95                         device = optarg;
  96                         break;
  97
  98                 case 's':
  99                         doselect = 1;
 100                         break;
 101
 102                 case 'p':
 103                         dopoll = 1;
 104                         break;
 105
 106                 case 't':
 107                         dotimeout = 1;
 108                         break;
 109
 110                 case 'n':
 111                         dononblock = 1;
 112                         break;
 113
 114                 default:
 115                         usage();
 116                         /* NOTREACHED */
 117                 }
 118         }
 119
 120         if (doselect && dopoll) {
 121                 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
 122                 return 1;
 123         }
 124         if (dotimeout && !doselect && !dopoll) {
 125                 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
 126                 return 1;
 127         }
 128         if (device == NULL) {
 129                 if (pcap_findalldevs(&devlist, ebuf) == -1)
 130                         error("%s", ebuf);
 131                 if (devlist == NULL)
 132                         error("no interfaces available for capture");
 133                 device = strdup(devlist->name);
 134                 pcap_freealldevs(devlist);
 135         }
 136         *ebuf = '\0';
 137         pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
 138         if (pd == NULL)
 139                 error("%s", ebuf);
 140         else if (*ebuf)
 141                 warning("%s", ebuf);
 142         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 143                 localnet = 0;
 144                 netmask = 0;
 145                 warning("%s", ebuf);
 146         }
 147         cmdbuf = copy_argv(&argv[optind]);
 148
 149         if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
 150                 error("%s", pcap_geterr(pd));
 151
 152         if (pcap_setfilter(pd, &fcode) < 0)
 153                 error("%s", pcap_geterr(pd));
 154         if (pcap_get_selectable_fd(pd) == -1)
 155                 error("pcap_get_selectable_fd() fails");
 156         if (dononblock) {
 157                 if (pcap_setnonblock(pd, 1, ebuf) == -1)
 158                         error("pcap_setnonblock failed: %s", ebuf);
 159         }
 160         selectable_fd = pcap_get_selectable_fd(pd);
 161         printf("Listening on %s\n", device);
 162         if (doselect) {
 163                 for (;;) {
 164                         fd_set setread, setexcept;
 165                         struct timeval seltimeout;
 166
 167                         FD_ZERO(&setread);
 168                         FD_SET(selectable_fd, &setread);
 169                         FD_ZERO(&setexcept);
 170                         FD_SET(selectable_fd, &setexcept);
 171                         if (dotimeout) {
 172                                 seltimeout.tv_sec = 0;
 173                                 seltimeout.tv_usec = 1000;
 174                                 status = select(selectable_fd + 1, &setread,
 175                                     NULL, &setexcept, &seltimeout);
 176                         } else {
 177                                 status = select(selectable_fd + 1, &setread,
 178                                     NULL, &setexcept, NULL);
 179                         }
 180                         if (status == -1) {
 181                                 printf("Select returns error (%s)\n",
 182                                     strerror(errno));
 183                         } else {
 184                                 if (status == 0)
 185                                         printf("Select timed out: ");
 186                                 else
 187                                         printf("Select returned a descriptor: ");
 188                                 if (FD_ISSET(selectable_fd, &setread))
 189                                         printf("readable, ");
 190                                 else
 191                                         printf("not readable, ");
 192                                 if (FD_ISSET(selectable_fd, &setexcept))
 193                                         printf("exceptional condition\n");
 194                                 else
 195                                         printf("no exceptional condition\n");
 196                                 packet_count = 0;
 197                                 status = pcap_dispatch(pd, -1, countme,
 198                                     (u_char *)&packet_count);
 199                                 if (status < 0)
 200                                         break;
 201                                 printf("%d packets seen, %d packets counted after select returns\n",
 202                                     status, packet_count);
 203                         }
 204                 }
 205         } else if (dopoll) {
 206                 for (;;) {
 207                         struct pollfd fd;
 208                         int polltimeout;
 209
 210                         fd.fd = selectable_fd;
 211                         fd.events = POLLIN;
 212                         if (dotimeout)
 213                                 polltimeout = 1;
 214                         else
 215                                 polltimeout = -1;
 216                         status = poll(&fd, 1, polltimeout);
 217                         if (status == -1) {
 218                                 printf("Poll returns error (%s)\n",
 219                                     strerror(errno));
 220                         } else {
 221                                 if (status == 0)
 222                                         printf("Poll timed out\n");
 223                                 else {
 224                                         printf("Poll returned a descriptor: ");
 225                                         if (fd.revents & POLLIN)
 226                                                 printf("readable, ");
 227                                         else
 228                                                 printf("not readable, ");
 229                                         if (fd.revents & POLLERR)
 230                                                 printf("exceptional condition, ");
 231                                         else
 232                                                 printf("no exceptional condition, ");
 233                                         if (fd.revents & POLLHUP)
 234                                                 printf("disconnect, ");
 235                                         else
 236                                                 printf("no disconnect, ");
 237                                         if (fd.revents & POLLNVAL)
 238                                                 printf("invalid\n");
 239                                         else
 240                                                 printf("not invalid\n");
 241                                 }
 242                                 packet_count = 0;
 243                                 status = pcap_dispatch(pd, -1, countme,
 244                                     (u_char *)&packet_count);
 245                                 if (status < 0)
 246                                         break;
 247                                 printf("%d packets seen, %d packets counted after poll returns\n",
 248                                     status, packet_count);
 249                         }
 250                 }
 251         } else {
 252                 for (;;) {
 253                         packet_count = 0;
 254                         status = pcap_dispatch(pd, -1, countme,
 255                             (u_char *)&packet_count);
 256                         if (status < 0)
 257                                 break;
 258                         printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
 259                             status, packet_count);
 260                 }
 261         }
 262         if (status == -2) {
 263                 /*
 264                  * We got interrupted, so perhaps we didn't
 265                  * manage to finish a line we were printing.
 266                  * Print an extra newline, just in case.
 267                  */
 268                 putchar('\n');
 269         }
 270         (void)fflush(stdout);
 271         if (status == -1) {
 272                 /*
 273                  * Error.  Report it.
 274                  */
 275                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 276                     program_name, pcap_geterr(pd));
 277         }
 278         pcap_close(pd);
 279         exit(status == -1 ? 1 : 0);
 280 }
 281
 282 static void
 283 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 284 {
 285         int *counterp = (int *)user;
 286
 287         (*counterp)++;
 288 }
 289
 290 static void
 291 usage(void)
 292 {
 293         (void)fprintf(stderr, "Usage: %s [ -sptn ] [ -i interface ] [expression]\n",
 294             program_name);
 295         exit(1);
 296 }
 297
 298 /* VARARGS */
 299 static void
 300 error(const char *fmt, ...)
 301 {
 302         va_list ap;
 303
 304         (void)fprintf(stderr, "%s: ", program_name);
 305         va_start(ap, fmt);
 306         (void)vfprintf(stderr, fmt, ap);
 307         va_end(ap);
 308         if (*fmt) {
 309                 fmt += strlen(fmt);
 310                 if (fmt[-1] != '\n')
 311                         (void)fputc('\n', stderr);
 312         }
 313         exit(1);
 314         /* NOTREACHED */
 315 }
 316
 317 /* VARARGS */
 318 static void
 319 warning(const char *fmt, ...)
 320 {
 321         va_list ap;
 322
 323         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 324         va_start(ap, fmt);
 325         (void)vfprintf(stderr, fmt, ap);
 326         va_end(ap);
 327         if (*fmt) {
 328                 fmt += strlen(fmt);
 329                 if (fmt[-1] != '\n')
 330                         (void)fputc('\n', stderr);
 331         }
 332 }
 333
 334 /*
 335  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 336  */
 337 static char *
 338 copy_argv(register char **argv)
 339 {
 340         register char **p;
 341         register u_int len = 0;
 342         char *buf;
 343         char *src, *dst;
 344
 345         p = argv;
 346         if (*p == 0)
 347                 return 0;
 348
 349         while (*p)
 350                 len += strlen(*p++) + 1;
 351
 352         buf = (char *)malloc(len);
 353         if (buf == NULL)
 354                 error("copy_argv: malloc");
 355
 356         p = argv;
 357         dst = buf;
 358         while ((src = *p++) != NULL) {
 359                 while ((*dst++ = *src++) != '\0')
 360                         ;
 361                 dst[-1] = ' ';
 362         }
 363         dst[-1] = '\0';
 364
 365         return buf;
 366 }