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 <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <stdarg.h>
32 #include <limits.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 #include <pcap.h>
40
41 static char *program_name;
42
43 /* Forwards */
44 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
45 static void usage(void) __attribute__((noreturn));
46 static void error(const char *, ...);
47 static void warning(const char *, ...);
48 static char *copy_argv(char **);
49
50 static pcap_t *pd;
51
52 extern int optind;
53 extern int opterr;
54 extern char *optarg;
55
56 int
main(int argc,char ** argv)57 main(int argc, char **argv)
58 {
59 register int op;
60 register char *cp, *cmdbuf, *device;
61 long longarg;
62 char *p;
63 int timeout = 1000;
64 int immediate = 0;
65 int nonblock = 0;
66 bpf_u_int32 localnet, netmask;
67 struct bpf_program fcode;
68 char ebuf[PCAP_ERRBUF_SIZE];
69 int status;
70 int packet_count;
71
72 device = NULL;
73 if ((cp = strrchr(argv[0], '/')) != NULL)
74 program_name = cp + 1;
75 else
76 program_name = argv[0];
77
78 opterr = 0;
79 while ((op = getopt(argc, argv, "i:mnt:")) != -1) {
80 switch (op) {
81
82 case 'i':
83 device = optarg;
84 break;
85
86 case 'm':
87 immediate = 1;
88 break;
89
90 case 'n':
91 nonblock = 1;
92 break;
93
94 case 't':
95 longarg = strtol(optarg, &p, 10);
96 if (p == optarg || *p != '\0') {
97 error("Timeout value \"%s\" is not a number",
98 optarg);
99 /* NOTREACHED */
100 }
101 if (longarg < 0) {
102 error("Timeout value %ld is negative", longarg);
103 /* NOTREACHED */
104 }
105 if (longarg > INT_MAX) {
106 error("Timeout value %ld is too large (> %d)",
107 longarg, INT_MAX);
108 /* NOTREACHED */
109 }
110 timeout = (int)longarg;
111 break;
112
113 default:
114 usage();
115 /* NOTREACHED */
116 }
117 }
118
119 if (device == NULL) {
120 device = pcap_lookupdev(ebuf);
121 if (device == NULL)
122 error("%s", ebuf);
123 }
124 *ebuf = '\0';
125 pd = pcap_create(device, ebuf);
126 if (pd == NULL)
127 error("%s", ebuf);
128 status = pcap_set_snaplen(pd, 65535);
129 if (status != 0)
130 error("%s: pcap_set_snaplen failed: %s",
131 device, pcap_statustostr(status));
132 if (immediate) {
133 status = pcap_set_immediate_mode(pd, 1);
134 if (status != 0)
135 error("%s: pcap_set_immediate_mode failed: %s",
136 device, pcap_statustostr(status));
137 }
138 status = pcap_set_timeout(pd, timeout);
139 if (status != 0)
140 error("%s: pcap_set_timeout failed: %s",
141 device, pcap_statustostr(status));
142 status = pcap_activate(pd);
143 if (status < 0) {
144 /*
145 * pcap_activate() failed.
146 */
147 error("%s: %s\n(%s)", device,
148 pcap_statustostr(status), pcap_geterr(pd));
149 } else if (status > 0) {
150 /*
151 * pcap_activate() succeeded, but it's warning us
152 * of a problem it had.
153 */
154 warning("%s: %s\n(%s)", device,
155 pcap_statustostr(status), pcap_geterr(pd));
156 }
157 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
158 localnet = 0;
159 netmask = 0;
160 warning("%s", ebuf);
161 }
162 cmdbuf = copy_argv(&argv[optind]);
163
164 if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
165 error("%s", pcap_geterr(pd));
166
167 if (pcap_setfilter(pd, &fcode) < 0)
168 error("%s", pcap_geterr(pd));
169 if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
170 error("pcap_setnonblock failed: %s", ebuf);
171 printf("Listening on %s\n", device);
172 for (;;) {
173 packet_count = 0;
174 status = pcap_dispatch(pd, -1, countme,
175 (u_char *)&packet_count);
176 if (status < 0)
177 break;
178 if (status != 0) {
179 printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
180 status, packet_count);
181 }
182 }
183 if (status == -2) {
184 /*
185 * We got interrupted, so perhaps we didn't
186 * manage to finish a line we were printing.
187 * Print an extra newline, just in case.
188 */
189 putchar('\n');
190 }
191 (void)fflush(stdout);
192 if (status == -1) {
193 /*
194 * Error. Report it.
195 */
196 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
197 program_name, pcap_geterr(pd));
198 }
199 pcap_close(pd);
200 exit(status == -1 ? 1 : 0);
201 }
202
203 static void
countme(u_char * user,const struct pcap_pkthdr * h,const u_char * sp)204 countme(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
205 {
206 int *counterp = (int *)user;
207
208 (*counterp)++;
209 }
210
211 static void
usage(void)212 usage(void)
213 {
214 (void)fprintf(stderr, "Usage: %s [ -mn ] [ -i interface ] [ -t timeout] [expression]\n",
215 program_name);
216 exit(1);
217 }
218
219 /* VARARGS */
220 static void
error(const char * fmt,...)221 error(const char *fmt, ...)
222 {
223 va_list ap;
224
225 (void)fprintf(stderr, "%s: ", program_name);
226 va_start(ap, fmt);
227 (void)vfprintf(stderr, fmt, ap);
228 va_end(ap);
229 if (*fmt) {
230 fmt += strlen(fmt);
231 if (fmt[-1] != '\n')
232 (void)fputc('\n', stderr);
233 }
234 exit(1);
235 /* NOTREACHED */
236 }
237
238 /* VARARGS */
239 static void
warning(const char * fmt,...)240 warning(const char *fmt, ...)
241 {
242 va_list ap;
243
244 (void)fprintf(stderr, "%s: WARNING: ", program_name);
245 va_start(ap, fmt);
246 (void)vfprintf(stderr, fmt, ap);
247 va_end(ap);
248 if (*fmt) {
249 fmt += strlen(fmt);
250 if (fmt[-1] != '\n')
251 (void)fputc('\n', stderr);
252 }
253 }
254
255 /*
256 * Copy arg vector into a new buffer, concatenating arguments with spaces.
257 */
258 static char *
copy_argv(register char ** argv)259 copy_argv(register char **argv)
260 {
261 register char **p;
262 register u_int len = 0;
263 char *buf;
264 char *src, *dst;
265
266 p = argv;
267 if (*p == 0)
268 return 0;
269
270 while (*p)
271 len += strlen(*p++) + 1;
272
273 buf = (char *)malloc(len);
274 if (buf == NULL)
275 error("copy_argv: malloc");
276
277 p = argv;
278 dst = buf;
279 while ((src = *p++) != NULL) {
280 while ((*dst++ = *src++) != '\0')
281 ;
282 dst[-1] = ' ';
283 }
284 dst[-1] = '\0';
285
286 return buf;
287 }
288