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 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdarg.h>
34 #include <limits.h>
35 #ifdef _WIN32
36   #include "getopt.h"
37 #else
38   #include <unistd.h>
39 #endif
40 #include <errno.h>
41 #ifndef _WIN32
42   #include <signal.h>
43 #endif
44 #include <sys/types.h>
45 
46 #include <pcap.h>
47 
48 #include "pcap/funcattrs.h"
49 
50 #ifdef _WIN32
51   #include "portability.h"
52 #endif
53 
54 static char *program_name;
55 
56 /* Forwards */
57 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
58 static void PCAP_NORETURN usage(void);
59 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
60 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
61 static char *copy_argv(char **);
62 
63 static pcap_t *pd;
64 #ifndef _WIN32
65 static int breaksigint = 0;
66 #endif
67 
68 #ifndef _WIN32
69 static void
sigint_handler(int signum _U_)70 sigint_handler(int signum _U_)
71 {
72 	if (breaksigint)
73 		pcap_breakloop(pd);
74 }
75 #endif
76 
77 #ifdef _WIN32
78 /*
79  * We don't have UN*X-style signals, so we don't have anything to test.
80  */
81 #define B_OPTION	""
82 #define R_OPTION	""
83 #define S_OPTION	""
84 #else
85 /*
86  * We do have UN*X-style signals (we assume that "not Windows" means "UN*X").
87  */
88 #define B_OPTION	"b"
89 #define R_OPTION	"r"
90 #define S_OPTION	"s"
91 #endif
92 
93 #define COMMAND_OPTIONS	B_OPTION "i:mn" R_OPTION S_OPTION "t:"
94 #define USAGE_OPTIONS	"-" B_OPTION "mn" R_OPTION S_OPTION
95 
96 int
main(int argc,char ** argv)97 main(int argc, char **argv)
98 {
99 	register int op;
100 	register char *cp, *cmdbuf, *device;
101 	long longarg;
102 	char *p;
103 	int timeout = 1000;
104 	int immediate = 0;
105 	int nonblock = 0;
106 #ifndef _WIN32
107 	int sigrestart = 0;
108 	int catchsigint = 0;
109 #endif
110 	pcap_if_t *devlist;
111 	bpf_u_int32 localnet, netmask;
112 	struct bpf_program fcode;
113 	char ebuf[PCAP_ERRBUF_SIZE];
114 	int status;
115 	int packet_count;
116 
117 	device = NULL;
118 	if ((cp = strrchr(argv[0], '/')) != NULL)
119 		program_name = cp + 1;
120 	else
121 		program_name = argv[0];
122 
123 	opterr = 0;
124 	while ((op = getopt(argc, argv, COMMAND_OPTIONS)) != -1) {
125 		switch (op) {
126 
127 #ifndef _WIN32
128 		case 'b':
129 			breaksigint = 1;
130 			break;
131 #endif
132 
133 		case 'i':
134 			device = optarg;
135 			break;
136 
137 		case 'm':
138 			immediate = 1;
139 			break;
140 
141 		case 'n':
142 			nonblock = 1;
143 			break;
144 
145 #ifndef _WIN32
146 		case 'r':
147 			sigrestart = 1;
148 			break;
149 
150 		case 's':
151 			catchsigint = 1;
152 			break;
153 #endif
154 
155 		case 't':
156 			longarg = strtol(optarg, &p, 10);
157 			if (p == optarg || *p != '\0') {
158 				error("Timeout value \"%s\" is not a number",
159 				    optarg);
160 				/* NOTREACHED */
161 			}
162 			if (longarg < 0) {
163 				error("Timeout value %ld is negative", longarg);
164 				/* NOTREACHED */
165 			}
166 			if (longarg > INT_MAX) {
167 				error("Timeout value %ld is too large (> %d)",
168 				    longarg, INT_MAX);
169 				/* NOTREACHED */
170 			}
171 			timeout = (int)longarg;
172 			break;
173 
174 		default:
175 			usage();
176 			/* NOTREACHED */
177 		}
178 	}
179 
180 	if (device == NULL) {
181 		if (pcap_findalldevs(&devlist, ebuf) == -1)
182 			error("%s", ebuf);
183 		if (devlist == NULL)
184 			error("no interfaces available for capture");
185 		device = strdup(devlist->name);
186 		pcap_freealldevs(devlist);
187 	}
188 	*ebuf = '\0';
189 
190 #ifndef _WIN32
191 	/*
192 	 * If we were told to catch SIGINT, do so.
193 	 */
194 	if (catchsigint) {
195 		struct sigaction action;
196 
197 		action.sa_handler = sigint_handler;
198 		sigemptyset(&action.sa_mask);
199 
200 		/*
201 		 * Should SIGINT interrupt, or restart, system calls?
202 		 */
203 		action.sa_flags = sigrestart ? SA_RESTART : 0;
204 
205 		if (sigaction(SIGINT, &action, NULL) == -1)
206 			error("Can't catch SIGINT: %s\n",
207 			    strerror(errno));
208 	}
209 #endif
210 
211 	pd = pcap_create(device, ebuf);
212 	if (pd == NULL)
213 		error("%s", ebuf);
214 	status = pcap_set_snaplen(pd, 65535);
215 	if (status != 0)
216 		error("%s: pcap_set_snaplen failed: %s",
217 			    device, pcap_statustostr(status));
218 	if (immediate) {
219 		status = pcap_set_immediate_mode(pd, 1);
220 		if (status != 0)
221 			error("%s: pcap_set_immediate_mode failed: %s",
222 			    device, pcap_statustostr(status));
223 	}
224 	status = pcap_set_timeout(pd, timeout);
225 	if (status != 0)
226 		error("%s: pcap_set_timeout failed: %s",
227 		    device, pcap_statustostr(status));
228 	status = pcap_activate(pd);
229 	if (status < 0) {
230 		/*
231 		 * pcap_activate() failed.
232 		 */
233 		error("%s: %s\n(%s)", device,
234 		    pcap_statustostr(status), pcap_geterr(pd));
235 	} else if (status > 0) {
236 		/*
237 		 * pcap_activate() succeeded, but it's warning us
238 		 * of a problem it had.
239 		 */
240 		warning("%s: %s\n(%s)", device,
241 		    pcap_statustostr(status), pcap_geterr(pd));
242 	}
243 	if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
244 		localnet = 0;
245 		netmask = 0;
246 		warning("%s", ebuf);
247 	}
248 	cmdbuf = copy_argv(&argv[optind]);
249 
250 	if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
251 		error("%s", pcap_geterr(pd));
252 
253 	if (pcap_setfilter(pd, &fcode) < 0)
254 		error("%s", pcap_geterr(pd));
255 	if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
256 		error("pcap_setnonblock failed: %s", ebuf);
257 	printf("Listening on %s\n", device);
258 	for (;;) {
259 		packet_count = 0;
260 		status = pcap_dispatch(pd, -1, countme,
261 		    (u_char *)&packet_count);
262 		if (status < 0)
263 			break;
264 		if (status != 0) {
265 			printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
266 			    status, packet_count);
267 			struct pcap_stat ps;
268 			pcap_stats(pd, &ps);
269 			printf("%d ps_recv, %d ps_drop, %d ps_ifdrop\n",
270 			    ps.ps_recv, ps.ps_drop, ps.ps_ifdrop);
271 		}
272 	}
273 	if (status == -2) {
274 		/*
275 		 * We got interrupted, so perhaps we didn't
276 		 * manage to finish a line we were printing.
277 		 * Print an extra newline, just in case.
278 		 */
279 		putchar('\n');
280 		printf("Broken out of loop from SIGINT handler\n");
281 	}
282 	(void)fflush(stdout);
283 	if (status == -1) {
284 		/*
285 		 * Error.  Report it.
286 		 */
287 		(void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
288 		    program_name, pcap_geterr(pd));
289 	}
290 	pcap_close(pd);
291 	pcap_freecode(&fcode);
292 	free(cmdbuf);
293 	exit(status == -1 ? 1 : 0);
294 }
295 
296 static void
countme(u_char * user,const struct pcap_pkthdr * h _U_,const u_char * sp _U_)297 countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
298 {
299 	int *counterp = (int *)user;
300 
301 	(*counterp)++;
302 }
303 
304 static void
usage(void)305 usage(void)
306 {
307 	(void)fprintf(stderr, "Usage: %s [ " USAGE_OPTIONS " ] [ -i interface ] [ -t timeout] [expression]\n",
308 	    program_name);
309 	exit(1);
310 }
311 
312 /* VARARGS */
313 static void
error(const char * fmt,...)314 error(const char *fmt, ...)
315 {
316 	va_list ap;
317 
318 	(void)fprintf(stderr, "%s: ", program_name);
319 	va_start(ap, fmt);
320 	(void)vfprintf(stderr, fmt, ap);
321 	va_end(ap);
322 	if (*fmt) {
323 		fmt += strlen(fmt);
324 		if (fmt[-1] != '\n')
325 			(void)fputc('\n', stderr);
326 	}
327 	exit(1);
328 	/* NOTREACHED */
329 }
330 
331 /* VARARGS */
332 static void
warning(const char * fmt,...)333 warning(const char *fmt, ...)
334 {
335 	va_list ap;
336 
337 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
338 	va_start(ap, fmt);
339 	(void)vfprintf(stderr, fmt, ap);
340 	va_end(ap);
341 	if (*fmt) {
342 		fmt += strlen(fmt);
343 		if (fmt[-1] != '\n')
344 			(void)fputc('\n', stderr);
345 	}
346 }
347 
348 /*
349  * Copy arg vector into a new buffer, concatenating arguments with spaces.
350  */
351 static char *
copy_argv(register char ** argv)352 copy_argv(register char **argv)
353 {
354 	register char **p;
355 	register size_t len = 0;
356 	char *buf;
357 	char *src, *dst;
358 
359 	p = argv;
360 	if (*p == 0)
361 		return 0;
362 
363 	while (*p)
364 		len += strlen(*p++) + 1;
365 
366 	buf = (char *)malloc(len);
367 	if (buf == NULL)
368 		error("copy_argv: malloc");
369 
370 	p = argv;
371 	dst = buf;
372 	while ((src = *p++) != NULL) {
373 		while ((*dst++ = *src++) != '\0')
374 			;
375 		dst[-1] = ' ';
376 	}
377 	dst[-1] = '\0';
378 
379 	return buf;
380 }
381