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 static 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
main(int argc,char ** argv)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 const char *mechanism;
74 struct bpf_program fcode;
75 char ebuf[PCAP_ERRBUF_SIZE];
76 pcap_if_t *devlist;
77 int selectable_fd;
78 struct timeval *required_timeout;
79 int status;
80 int packet_count;
81
82 device = NULL;
83 doselect = 0;
84 dopoll = 0;
85 mechanism = NULL;
86 dotimeout = 0;
87 dononblock = 0;
88 if ((cp = strrchr(argv[0], '/')) != NULL)
89 program_name = cp + 1;
90 else
91 program_name = argv[0];
92
93 opterr = 0;
94 while ((op = getopt(argc, argv, "i:sptn")) != -1) {
95 switch (op) {
96
97 case 'i':
98 device = optarg;
99 break;
100
101 case 's':
102 doselect = 1;
103 mechanism = "select() and pcap_dispatch()";
104 break;
105
106 case 'p':
107 dopoll = 1;
108 mechanism = "poll() and pcap_dispatch()";
109 break;
110
111 case 't':
112 dotimeout = 1;
113 break;
114
115 case 'n':
116 dononblock = 1;
117 break;
118
119 default:
120 usage();
121 /* NOTREACHED */
122 }
123 }
124
125 if (doselect && dopoll) {
126 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
127 return 1;
128 }
129 if (dotimeout && !doselect && !dopoll) {
130 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
131 return 1;
132 }
133 if (device == NULL) {
134 if (pcap_findalldevs(&devlist, ebuf) == -1)
135 error("%s", ebuf);
136 if (devlist == NULL)
137 error("no interfaces available for capture");
138 device = strdup(devlist->name);
139 pcap_freealldevs(devlist);
140 }
141 *ebuf = '\0';
142 pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
143 if (pd == NULL)
144 error("%s", ebuf);
145 else if (*ebuf)
146 warning("%s", ebuf);
147 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
148 localnet = 0;
149 netmask = 0;
150 warning("%s", ebuf);
151 }
152 cmdbuf = copy_argv(&argv[optind]);
153
154 if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
155 error("%s", pcap_geterr(pd));
156 if (pcap_setfilter(pd, &fcode) < 0)
157 error("%s", pcap_geterr(pd));
158
159 if (doselect || dopoll) {
160 /*
161 * We need either an FD on which to do select()/poll()
162 * or, if there isn't one, a timeout to use in select()/
163 * poll().
164 */
165 selectable_fd = pcap_get_selectable_fd(pd);
166 if (selectable_fd == -1) {
167 printf("Listening on %s, using %s, with a timeout\n",
168 device, mechanism);
169 required_timeout = pcap_get_required_select_timeout(pd);
170 if (required_timeout == NULL)
171 error("select()/poll() isn't supported on %s, even with a timeout",
172 device);
173
174 /*
175 * As we won't be notified by select() or poll()
176 * that a read can be done, we'll have to periodically
177 * try reading from the device every time the required
178 * timeout expires, and we don't want those attempts
179 * to block if nothing has arrived in that interval,
180 * so we want to force non-blocking mode.
181 */
182 dononblock = 1;
183 } else {
184 printf("Listening on %s, using %s\n", device,
185 mechanism);
186 required_timeout = NULL;
187 }
188 } else
189 printf("Listening on %s, using pcap_dispatch()\n", device);
190
191 if (dononblock) {
192 if (pcap_setnonblock(pd, 1, ebuf) == -1)
193 error("pcap_setnonblock failed: %s", ebuf);
194 }
195 if (doselect) {
196 for (;;) {
197 fd_set setread, setexcept;
198 struct timeval seltimeout;
199
200 FD_ZERO(&setread);
201 if (selectable_fd != -1) {
202 FD_SET(selectable_fd, &setread);
203 FD_ZERO(&setexcept);
204 FD_SET(selectable_fd, &setexcept);
205 }
206 if (dotimeout) {
207 seltimeout.tv_sec = 0;
208 if (required_timeout != NULL &&
209 required_timeout->tv_usec < 1000)
210 seltimeout.tv_usec = required_timeout->tv_usec;
211 else
212 seltimeout.tv_usec = 1000;
213 status = select(selectable_fd + 1, &setread,
214 NULL, &setexcept, &seltimeout);
215 } else if (required_timeout != NULL) {
216 seltimeout = *required_timeout;
217 status = select(selectable_fd + 1, &setread,
218 NULL, &setexcept, &seltimeout);
219 } else {
220 status = select((selectable_fd == -1) ?
221 0 : selectable_fd + 1, &setread,
222 NULL, &setexcept, NULL);
223 }
224 if (status == -1) {
225 printf("Select returns error (%s)\n",
226 strerror(errno));
227 } else {
228 if (selectable_fd == -1) {
229 if (status != 0)
230 printf("Select returned a descriptor\n");
231 } else {
232 if (status == 0)
233 printf("Select timed out: ");
234 else
235 printf("Select returned a descriptor: ");
236 if (FD_ISSET(selectable_fd, &setread))
237 printf("readable, ");
238 else
239 printf("not readable, ");
240 if (FD_ISSET(selectable_fd, &setexcept))
241 printf("exceptional condition\n");
242 else
243 printf("no exceptional condition\n");
244 }
245 packet_count = 0;
246 status = pcap_dispatch(pd, -1, countme,
247 (u_char *)&packet_count);
248 if (status < 0)
249 break;
250 /*
251 * Don't report this if we're using a
252 * required timeout and we got no packets,
253 * because that could be a very short timeout,
254 * and we don't want to spam the user with
255 * a ton of "no packets" reports.
256 */
257 if (status != 0 || packet_count != 0 ||
258 required_timeout != NULL) {
259 printf("%d packets seen, %d packets counted after select returns\n",
260 status, packet_count);
261 }
262 }
263 }
264 } else if (dopoll) {
265 for (;;) {
266 struct pollfd fd;
267 int polltimeout;
268
269 fd.fd = selectable_fd;
270 fd.events = POLLIN;
271 if (dotimeout)
272 polltimeout = 1;
273 else if (required_timeout != NULL &&
274 required_timeout->tv_usec >= 1000)
275 polltimeout = required_timeout->tv_usec/1000;
276 else
277 polltimeout = -1;
278 status = poll(&fd, (selectable_fd == -1) ? 0 : 1, polltimeout);
279 if (status == -1) {
280 printf("Poll returns error (%s)\n",
281 strerror(errno));
282 } else {
283 if (selectable_fd == -1) {
284 if (status != 0)
285 printf("Poll returned a descriptor\n");
286 } else {
287 if (status == 0)
288 printf("Poll timed out\n");
289 else {
290 printf("Poll returned a descriptor: ");
291 if (fd.revents & POLLIN)
292 printf("readable, ");
293 else
294 printf("not readable, ");
295 if (fd.revents & POLLERR)
296 printf("exceptional condition, ");
297 else
298 printf("no exceptional condition, ");
299 if (fd.revents & POLLHUP)
300 printf("disconnect, ");
301 else
302 printf("no disconnect, ");
303 if (fd.revents & POLLNVAL)
304 printf("invalid\n");
305 else
306 printf("not invalid\n");
307 }
308 }
309 packet_count = 0;
310 status = pcap_dispatch(pd, -1, countme,
311 (u_char *)&packet_count);
312 if (status < 0)
313 break;
314 /*
315 * Don't report this if we're using a
316 * required timeout and we got no packets,
317 * because that could be a very short timeout,
318 * and we don't want to spam the user with
319 * a ton of "no packets" reports.
320 */
321 if (status != 0 || packet_count != 0 ||
322 required_timeout != NULL) {
323 printf("%d packets seen, %d packets counted after poll returns\n",
324 status, packet_count);
325 }
326 }
327 }
328 } else {
329 for (;;) {
330 packet_count = 0;
331 status = pcap_dispatch(pd, -1, countme,
332 (u_char *)&packet_count);
333 if (status < 0)
334 break;
335 printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
336 status, packet_count);
337 }
338 }
339 if (status == -2) {
340 /*
341 * We got interrupted, so perhaps we didn't
342 * manage to finish a line we were printing.
343 * Print an extra newline, just in case.
344 */
345 putchar('\n');
346 }
347 (void)fflush(stdout);
348 if (status == -1) {
349 /*
350 * Error. Report it.
351 */
352 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
353 program_name, pcap_geterr(pd));
354 }
355 pcap_close(pd);
356 exit(status == -1 ? 1 : 0);
357 }
358
359 static void
countme(u_char * user,const struct pcap_pkthdr * h _U_,const u_char * sp _U_)360 countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
361 {
362 int *counterp = (int *)user;
363
364 (*counterp)++;
365 }
366
367 static void
usage(void)368 usage(void)
369 {
370 (void)fprintf(stderr, "Usage: %s [ -sptn ] [ -i interface ] [expression]\n",
371 program_name);
372 exit(1);
373 }
374
375 /* VARARGS */
376 static void
error(const char * fmt,...)377 error(const char *fmt, ...)
378 {
379 va_list ap;
380
381 (void)fprintf(stderr, "%s: ", program_name);
382 va_start(ap, fmt);
383 (void)vfprintf(stderr, fmt, ap);
384 va_end(ap);
385 if (*fmt) {
386 fmt += strlen(fmt);
387 if (fmt[-1] != '\n')
388 (void)fputc('\n', stderr);
389 }
390 exit(1);
391 /* NOTREACHED */
392 }
393
394 /* VARARGS */
395 static void
warning(const char * fmt,...)396 warning(const char *fmt, ...)
397 {
398 va_list ap;
399
400 (void)fprintf(stderr, "%s: WARNING: ", program_name);
401 va_start(ap, fmt);
402 (void)vfprintf(stderr, fmt, ap);
403 va_end(ap);
404 if (*fmt) {
405 fmt += strlen(fmt);
406 if (fmt[-1] != '\n')
407 (void)fputc('\n', stderr);
408 }
409 }
410
411 /*
412 * Copy arg vector into a new buffer, concatenating arguments with spaces.
413 */
414 static char *
copy_argv(register char ** argv)415 copy_argv(register char **argv)
416 {
417 register char **p;
418 register u_int len = 0;
419 char *buf;
420 char *src, *dst;
421
422 p = argv;
423 if (*p == 0)
424 return 0;
425
426 while (*p)
427 len += strlen(*p++) + 1;
428
429 buf = (char *)malloc(len);
430 if (buf == NULL)
431 error("copy_argv: malloc");
432
433 p = argv;
434 dst = buf;
435 while ((src = *p++) != NULL) {
436 while ((*dst++ = *src++) != '\0')
437 ;
438 dst[-1] = ' ';
439 }
440 dst[-1] = '\0';
441
442 return buf;
443 }
444