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