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
25static const char copyright[] _U_ =
26    "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
27The 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
55static char *program_name;
56
57/* Forwards */
58static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
59static void PCAP_NORETURN usage(void);
60static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
61static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
62static char *copy_argv(char **);
63
64static pcap_t *pd;
65
66int
67main(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, quiet;
73	const char *mechanism;
74	struct bpf_program fcode;
75	char ebuf[PCAP_ERRBUF_SIZE];
76	pcap_if_t *devlist;
77	int selectable_fd = -1;
78	const 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	quiet = 0;
89	if ((cp = strrchr(argv[0], '/')) != NULL)
90		program_name = cp + 1;
91	else
92		program_name = argv[0];
93
94	opterr = 0;
95	while ((op = getopt(argc, argv, "i:sptnq")) != -1) {
96		switch (op) {
97
98		case 'i':
99			device = optarg;
100			break;
101
102		case 's':
103			doselect = 1;
104			mechanism = "select() and pcap_dispatch()";
105			break;
106
107		case 'p':
108			dopoll = 1;
109			mechanism = "poll() and pcap_dispatch()";
110			break;
111
112		case 't':
113			dotimeout = 1;
114			break;
115
116		case 'n':
117			dononblock = 1;
118			break;
119
120		case 'q':
121			quiet = 1;
122			break;
123
124		default:
125			usage();
126			/* NOTREACHED */
127		}
128	}
129
130	if (doselect && dopoll) {
131		fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
132		return 1;
133	}
134	if (dotimeout && !doselect && !dopoll) {
135		fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
136		return 1;
137	}
138	if (device == NULL) {
139		if (pcap_findalldevs(&devlist, ebuf) == -1)
140			error("%s", ebuf);
141		if (devlist == NULL)
142			error("no interfaces available for capture");
143		device = strdup(devlist->name);
144		pcap_freealldevs(devlist);
145	}
146	*ebuf = '\0';
147	pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
148	if (pd == NULL)
149		error("%s", ebuf);
150	else if (*ebuf)
151		warning("%s", ebuf);
152	if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
153		localnet = 0;
154		netmask = 0;
155		warning("%s", ebuf);
156	}
157	cmdbuf = copy_argv(&argv[optind]);
158
159	if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
160		error("%s", pcap_geterr(pd));
161	if (pcap_setfilter(pd, &fcode) < 0)
162		error("%s", pcap_geterr(pd));
163
164	if (doselect || dopoll) {
165		/*
166		 * We need either an FD on which to do select()/poll()
167		 * or, if there isn't one, a timeout to use in select()/
168		 * poll().
169		 */
170		selectable_fd = pcap_get_selectable_fd(pd);
171		if (selectable_fd == -1) {
172			printf("Listening on %s, using %s, with a timeout\n",
173			    device, mechanism);
174			required_timeout = pcap_get_required_select_timeout(pd);
175			if (required_timeout == NULL)
176				error("select()/poll() isn't supported on %s, even with a timeout",
177				    device);
178
179			/*
180			 * As we won't be notified by select() or poll()
181			 * that a read can be done, we'll have to periodically
182			 * try reading from the device every time the required
183			 * timeout expires, and we don't want those attempts
184			 * to block if nothing has arrived in that interval,
185			 * so we want to force non-blocking mode.
186			 */
187			dononblock = 1;
188		} else {
189			printf("Listening on %s, using %s\n", device,
190			    mechanism);
191			required_timeout = NULL;
192		}
193	} else
194		printf("Listening on %s, using pcap_dispatch()\n", device);
195
196	if (dononblock) {
197		if (pcap_setnonblock(pd, 1, ebuf) == -1)
198			error("pcap_setnonblock failed: %s", ebuf);
199	}
200	if (doselect) {
201		for (;;) {
202			fd_set setread, setexcept;
203			struct timeval seltimeout;
204			struct timeval *timeoutp;
205
206			FD_ZERO(&setread);
207			if (selectable_fd != -1) {
208				FD_SET(selectable_fd, &setread);
209				FD_ZERO(&setexcept);
210				FD_SET(selectable_fd, &setexcept);
211			}
212			required_timeout = pcap_get_required_select_timeout(pd);
213			if (dotimeout) {
214				seltimeout.tv_sec = 0;
215				if (required_timeout != NULL &&
216				    required_timeout->tv_usec < 1000)
217					seltimeout.tv_usec = required_timeout->tv_usec;
218				else
219					seltimeout.tv_usec = 1000;
220				timeoutp = &seltimeout;
221			} else if (required_timeout != NULL) {
222				seltimeout = *required_timeout;
223				timeoutp = &seltimeout;
224			} else {
225				timeoutp = NULL;
226			}
227			status = select((selectable_fd == -1) ?
228			    0 : selectable_fd + 1, &setread, NULL, &setexcept,
229			    timeoutp);
230			if (status == -1) {
231				printf("Select returns error (%s)\n",
232				    strerror(errno));
233			} else {
234				if (!quiet) {
235					if (status == 0)
236						printf("Select timed out: ");
237					else{
238						printf("Select returned a descriptor: ");
239						if (FD_ISSET(selectable_fd, &setread))
240							printf("readable, ");
241						else
242							printf("not readable, ");
243						if (FD_ISSET(selectable_fd, &setexcept))
244							printf("exceptional condition\n");
245						else
246							printf("no exceptional condition\n");
247					}
248				}
249				packet_count = 0;
250				status = pcap_dispatch(pd, -1, countme,
251				    (u_char *)&packet_count);
252				if (status < 0)
253					break;
254				/*
255				 * Don't report this if we're using a
256				 * required timeout and we got no packets,
257				 * because that could be a very short timeout,
258				 * and we don't want to spam the user with
259				 * a ton of "no packets" reports.
260				 */
261				if (status != 0 || packet_count != 0 ||
262				    required_timeout != NULL) {
263					printf("%d packets seen, %d packets counted after select returns\n",
264					    status, packet_count);
265				}
266			}
267		}
268	} else if (dopoll) {
269		for (;;) {
270			struct pollfd fd;
271			int polltimeout;
272
273			fd.fd = selectable_fd;
274			fd.events = POLLIN;
275			required_timeout = pcap_get_required_select_timeout(pd);
276			if (dotimeout)
277				polltimeout = 1;
278			else if (required_timeout != NULL &&
279			    required_timeout->tv_usec >= 1000)
280				polltimeout = (int)(required_timeout->tv_usec/1000);
281			else
282				polltimeout = -1;
283			status = poll(&fd, (selectable_fd == -1) ? 0 : 1, polltimeout);
284			if (status == -1) {
285				printf("Poll returns error (%s)\n",
286				    strerror(errno));
287			} else {
288				if (!quiet) {
289					if (status == 0)
290						printf("Poll timed out\n");
291					else {
292						printf("Poll returned a descriptor: ");
293						if (fd.revents & POLLIN)
294							printf("readable, ");
295						else
296							printf("not readable, ");
297						if (fd.revents & POLLERR)
298							printf("exceptional condition, ");
299						else
300							printf("no exceptional condition, ");
301						if (fd.revents & POLLHUP)
302							printf("disconnect, ");
303						else
304							printf("no disconnect, ");
305						if (fd.revents & POLLNVAL)
306							printf("invalid\n");
307						else
308							printf("not invalid\n");
309					}
310				}
311				packet_count = 0;
312				status = pcap_dispatch(pd, -1, countme,
313				    (u_char *)&packet_count);
314				if (status < 0)
315					break;
316				/*
317				 * Don't report this if we're using a
318				 * required timeout and we got no packets,
319				 * because that could be a very short timeout,
320				 * and we don't want to spam the user with
321				 * a ton of "no packets" reports.
322				 */
323				if (status != 0 || packet_count != 0 ||
324				    required_timeout != NULL) {
325					printf("%d packets seen, %d packets counted after poll returns\n",
326					    status, packet_count);
327				}
328			}
329		}
330	} else {
331		for (;;) {
332			packet_count = 0;
333			status = pcap_dispatch(pd, -1, countme,
334			    (u_char *)&packet_count);
335			if (status < 0)
336				break;
337			printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
338			    status, packet_count);
339		}
340	}
341	if (status == -2) {
342		/*
343		 * We got interrupted, so perhaps we didn't
344		 * manage to finish a line we were printing.
345		 * Print an extra newline, just in case.
346		 */
347		putchar('\n');
348	}
349	(void)fflush(stdout);
350	if (status == -1) {
351		/*
352		 * Error.  Report it.
353		 */
354		(void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
355		    program_name, pcap_geterr(pd));
356	}
357	pcap_close(pd);
358	exit(status == -1 ? 1 : 0);
359}
360
361static void
362countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
363{
364	int *counterp = (int *)user;
365
366	(*counterp)++;
367}
368
369static void
370usage(void)
371{
372	(void)fprintf(stderr, "Usage: %s [ -sptnq ] [ -i interface ] [expression]\n",
373	    program_name);
374	exit(1);
375}
376
377/* VARARGS */
378static void
379error(const char *fmt, ...)
380{
381	va_list ap;
382
383	(void)fprintf(stderr, "%s: ", program_name);
384	va_start(ap, fmt);
385	(void)vfprintf(stderr, fmt, ap);
386	va_end(ap);
387	if (*fmt) {
388		fmt += strlen(fmt);
389		if (fmt[-1] != '\n')
390			(void)fputc('\n', stderr);
391	}
392	exit(1);
393	/* NOTREACHED */
394}
395
396/* VARARGS */
397static void
398warning(const char *fmt, ...)
399{
400	va_list ap;
401
402	(void)fprintf(stderr, "%s: WARNING: ", program_name);
403	va_start(ap, fmt);
404	(void)vfprintf(stderr, fmt, ap);
405	va_end(ap);
406	if (*fmt) {
407		fmt += strlen(fmt);
408		if (fmt[-1] != '\n')
409			(void)fputc('\n', stderr);
410	}
411}
412
413/*
414 * Copy arg vector into a new buffer, concatenating arguments with spaces.
415 */
416static char *
417copy_argv(register char **argv)
418{
419	register char **p;
420	register size_t len = 0;
421	char *buf;
422	char *src, *dst;
423
424	p = argv;
425	if (*p == 0)
426		return 0;
427
428	while (*p)
429		len += strlen(*p++) + 1;
430
431	buf = (char *)malloc(len);
432	if (buf == NULL)
433		error("copy_argv: malloc");
434
435	p = argv;
436	dst = buf;
437	while ((src = *p++) != NULL) {
438		while ((*dst++ = *src++) != '\0')
439			;
440		dst[-1] = ' ';
441	}
442	dst[-1] = '\0';
443
444	return buf;
445}
446