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