1 /* $NetBSD: capturetest.c,v 1.2 2014/11/19 19:33:31 christos Exp $ */
2
3 /*
4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that: (1) source code distributions
9 * retain the above copyright notice and this paragraph in its entirety, (2)
10 * distributions including binary code include the above copyright notice and
11 * this paragraph in its entirety in the documentation or other materials
12 * provided with the distribution, and (3) all advertising materials mentioning
13 * features or use of this software display the following acknowledgement:
14 * ``This product includes software developed by the University of California,
15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16 * the University nor the names of its contributors may be used to endorse
17 * or promote products derived from this software without specific prior
18 * written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 */
23
24 #include <sys/cdefs.h>
25 __RCSID("$NetBSD: capturetest.c,v 1.2 2014/11/19 19:33:31 christos Exp $");
26
27 #ifndef lint
28 static const char copyright[] =
29 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
30 The Regents of the University of California. All rights reserved.\n";
31 #endif
32
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <stdarg.h>
37 #include <limits.h>
38 #include <unistd.h>
39 #include <errno.h>
40 #include <sys/types.h>
41 #include <sys/select.h>
42 #include <poll.h>
43
44 #include <pcap.h>
45
46 static char *program_name;
47
48 /* Forwards */
49 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
50 static void usage(void) __attribute__((noreturn));
51 static void error(const char *, ...);
52 static void warning(const char *, ...);
53 static char *copy_argv(char **);
54
55 static pcap_t *pd;
56
57 extern int optind;
58 extern int opterr;
59 extern char *optarg;
60
61 int
main(int argc,char ** argv)62 main(int argc, char **argv)
63 {
64 register int op;
65 register char *cp, *cmdbuf, *device;
66 long longarg;
67 char *p;
68 int timeout = 1000;
69 int immediate = 0;
70 int nonblock = 0;
71 bpf_u_int32 localnet, netmask;
72 struct bpf_program fcode;
73 char ebuf[PCAP_ERRBUF_SIZE];
74 int status;
75 int packet_count;
76
77 device = NULL;
78 if ((cp = strrchr(argv[0], '/')) != NULL)
79 program_name = cp + 1;
80 else
81 program_name = argv[0];
82
83 opterr = 0;
84 while ((op = getopt(argc, argv, "i:mnt:")) != -1) {
85 switch (op) {
86
87 case 'i':
88 device = optarg;
89 break;
90
91 case 'm':
92 immediate = 1;
93 break;
94
95 case 'n':
96 nonblock = 1;
97 break;
98
99 case 't':
100 longarg = strtol(optarg, &p, 10);
101 if (p == optarg || *p != '\0') {
102 error("Timeout value \"%s\" is not a number",
103 optarg);
104 /* NOTREACHED */
105 }
106 if (longarg < 0) {
107 error("Timeout value %ld is negative", longarg);
108 /* NOTREACHED */
109 }
110 if (longarg > INT_MAX) {
111 error("Timeout value %ld is too large (> %d)",
112 longarg, INT_MAX);
113 /* NOTREACHED */
114 }
115 timeout = (int)longarg;
116 break;
117
118 default:
119 usage();
120 /* NOTREACHED */
121 }
122 }
123
124 if (device == NULL) {
125 device = pcap_lookupdev(ebuf);
126 if (device == NULL)
127 error("%s", ebuf);
128 }
129 *ebuf = '\0';
130 pd = pcap_create(device, ebuf);
131 if (pd == NULL)
132 error("%s", ebuf);
133 status = pcap_set_snaplen(pd, 65535);
134 if (status != 0)
135 error("%s: pcap_set_snaplen failed: %s",
136 device, pcap_statustostr(status));
137 if (immediate) {
138 status = pcap_set_immediate_mode(pd, 1);
139 if (status != 0)
140 error("%s: pcap_set_immediate_mode failed: %s",
141 device, pcap_statustostr(status));
142 }
143 status = pcap_set_timeout(pd, timeout);
144 if (status != 0)
145 error("%s: pcap_set_timeout failed: %s",
146 device, pcap_statustostr(status));
147 status = pcap_activate(pd);
148 if (status < 0) {
149 /*
150 * pcap_activate() failed.
151 */
152 error("%s: %s\n(%s)", device,
153 pcap_statustostr(status), pcap_geterr(pd));
154 } else if (status > 0) {
155 /*
156 * pcap_activate() succeeded, but it's warning us
157 * of a problem it had.
158 */
159 warning("%s: %s\n(%s)", device,
160 pcap_statustostr(status), pcap_geterr(pd));
161 }
162 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
163 localnet = 0;
164 netmask = 0;
165 warning("%s", ebuf);
166 }
167 cmdbuf = copy_argv(&argv[optind]);
168
169 if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
170 error("%s", pcap_geterr(pd));
171
172 if (pcap_setfilter(pd, &fcode) < 0)
173 error("%s", pcap_geterr(pd));
174 if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
175 error("pcap_setnonblock failed: %s", ebuf);
176 printf("Listening on %s\n", device);
177 for (;;) {
178 packet_count = 0;
179 status = pcap_dispatch(pd, -1, countme,
180 (u_char *)&packet_count);
181 if (status < 0)
182 break;
183 if (status != 0) {
184 printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
185 status, packet_count);
186 }
187 }
188 if (status == -2) {
189 /*
190 * We got interrupted, so perhaps we didn't
191 * manage to finish a line we were printing.
192 * Print an extra newline, just in case.
193 */
194 putchar('\n');
195 }
196 (void)fflush(stdout);
197 if (status == -1) {
198 /*
199 * Error. Report it.
200 */
201 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
202 program_name, pcap_geterr(pd));
203 }
204 pcap_close(pd);
205 exit(status == -1 ? 1 : 0);
206 }
207
208 static void
countme(u_char * user,const struct pcap_pkthdr * h,const u_char * sp)209 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
210 {
211 int *counterp = (int *)user;
212
213 (*counterp)++;
214 }
215
216 static void
usage(void)217 usage(void)
218 {
219 (void)fprintf(stderr, "Usage: %s [ -mn ] [ -i interface ] [ -t timeout] [expression]\n",
220 program_name);
221 exit(1);
222 }
223
224 /* VARARGS */
225 static void
error(const char * fmt,...)226 error(const char *fmt, ...)
227 {
228 va_list ap;
229
230 (void)fprintf(stderr, "%s: ", program_name);
231 va_start(ap, fmt);
232 (void)vfprintf(stderr, fmt, ap);
233 va_end(ap);
234 if (*fmt) {
235 fmt += strlen(fmt);
236 if (fmt[-1] != '\n')
237 (void)fputc('\n', stderr);
238 }
239 exit(1);
240 /* NOTREACHED */
241 }
242
243 /* VARARGS */
244 static void
warning(const char * fmt,...)245 warning(const char *fmt, ...)
246 {
247 va_list ap;
248
249 (void)fprintf(stderr, "%s: WARNING: ", program_name);
250 va_start(ap, fmt);
251 (void)vfprintf(stderr, fmt, ap);
252 va_end(ap);
253 if (*fmt) {
254 fmt += strlen(fmt);
255 if (fmt[-1] != '\n')
256 (void)fputc('\n', stderr);
257 }
258 }
259
260 /*
261 * Copy arg vector into a new buffer, concatenating arguments with spaces.
262 */
263 static char *
copy_argv(register char ** argv)264 copy_argv(register char **argv)
265 {
266 register char **p;
267 register u_int len = 0;
268 char *buf;
269 char *src, *dst;
270
271 p = argv;
272 if (*p == 0)
273 return 0;
274
275 while (*p)
276 len += strlen(*p++) + 1;
277
278 buf = (char *)malloc(len);
279 if (buf == NULL)
280 error("copy_argv: malloc");
281
282 p = argv;
283 dst = buf;
284 while ((src = *p++) != NULL) {
285 while ((*dst++ = *src++) != '\0')
286 ;
287 dst[-1] = ' ';
288 }
289 dst[-1] = '\0';
290
291 return buf;
292 }
293