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[] _U_ =
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 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <pcap.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <stdarg.h>
37 #include <unistd.h>
38 #include <fcntl.h>
39 #include <errno.h>
40 #include <arpa/inet.h>
41 #include <sys/types.h>
42 #include <sys/stat.h>
43
44 #ifndef HAVE___ATTRIBUTE__
45 #define __attribute__(x)
46 #endif
47
48 static char *program_name;
49
50 /* Forwards */
51 static void usage(void) __attribute__((noreturn));
52 static void error(const char *, ...)
53 __attribute__((noreturn, format (printf, 1, 2)));
54 static void warn(const char *, ...)
55 __attribute__((format (printf, 1, 2)));
56
57 extern int optind;
58 extern int opterr;
59 extern char *optarg;
60 #ifdef BDEBUG
61 int dflag;
62 #endif
63
64 /*
65 * On Windows, we need to open the file in binary mode, so that
66 * we get all the bytes specified by the size we get from "fstat()".
67 * On UNIX, that's not necessary. O_BINARY is defined on Windows;
68 * we define it as 0 if it's not defined, so it does nothing.
69 */
70 #ifndef O_BINARY
71 #define O_BINARY 0
72 #endif
73
74 static char *
read_infile(char * fname)75 read_infile(char *fname)
76 {
77 register int i, fd, cc;
78 register char *cp;
79 struct stat buf;
80
81 fd = open(fname, O_RDONLY|O_BINARY);
82 if (fd < 0)
83 error("can't open %s: %s", fname, pcap_strerror(errno));
84
85 if (fstat(fd, &buf) < 0)
86 error("can't stat %s: %s", fname, pcap_strerror(errno));
87
88 cp = malloc((u_int)buf.st_size + 1);
89 if (cp == NULL)
90 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
91 fname, pcap_strerror(errno));
92 cc = read(fd, cp, (u_int)buf.st_size);
93 if (cc < 0)
94 error("read %s: %s", fname, pcap_strerror(errno));
95 if (cc != buf.st_size)
96 error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
97
98 close(fd);
99 /* replace "# comment" with spaces */
100 for (i = 0; i < cc; i++) {
101 if (cp[i] == '#')
102 while (i < cc && cp[i] != '\n')
103 cp[i++] = ' ';
104 }
105 cp[cc] = '\0';
106 return (cp);
107 }
108
109 /* VARARGS */
110 static void
error(const char * fmt,...)111 error(const char *fmt, ...)
112 {
113 va_list ap;
114
115 (void)fprintf(stderr, "%s: ", program_name);
116 va_start(ap, fmt);
117 (void)vfprintf(stderr, fmt, ap);
118 va_end(ap);
119 if (*fmt) {
120 fmt += strlen(fmt);
121 if (fmt[-1] != '\n')
122 (void)fputc('\n', stderr);
123 }
124 exit(1);
125 /* NOTREACHED */
126 }
127
128 /* VARARGS */
129 static void
warn(const char * fmt,...)130 warn(const char *fmt, ...)
131 {
132 va_list ap;
133
134 (void)fprintf(stderr, "%s: WARNING: ", program_name);
135 va_start(ap, fmt);
136 (void)vfprintf(stderr, fmt, ap);
137 va_end(ap);
138 if (*fmt) {
139 fmt += strlen(fmt);
140 if (fmt[-1] != '\n')
141 (void)fputc('\n', stderr);
142 }
143 }
144
145 /*
146 * Copy arg vector into a new buffer, concatenating arguments with spaces.
147 */
148 static char *
copy_argv(register char ** argv)149 copy_argv(register char **argv)
150 {
151 register char **p;
152 register u_int len = 0;
153 char *buf;
154 char *src, *dst;
155
156 p = argv;
157 if (*p == 0)
158 return 0;
159
160 while (*p)
161 len += strlen(*p++) + 1;
162
163 buf = (char *)malloc(len);
164 if (buf == NULL)
165 error("copy_argv: malloc");
166
167 p = argv;
168 dst = buf;
169 while ((src = *p++) != NULL) {
170 while ((*dst++ = *src++) != '\0')
171 ;
172 dst[-1] = ' ';
173 }
174 dst[-1] = '\0';
175
176 return buf;
177 }
178
179 int
main(int argc,char ** argv)180 main(int argc, char **argv)
181 {
182 char *cp;
183 int op;
184 #ifndef BDEBUG
185 int dflag;
186 #endif
187 char *infile;
188 int Oflag;
189 long snaplen;
190 char *p;
191 int dlt;
192 bpf_u_int32 netmask = PCAP_NETMASK_UNKNOWN;
193 char *cmdbuf;
194 pcap_t *pd;
195 struct bpf_program fcode;
196
197 #ifdef WIN32
198 if(wsockinit() != 0) return 1;
199 #endif /* WIN32 */
200
201 #ifndef BDEBUG
202 dflag = 1;
203 #else
204 /* if optimizer debugging is enabled, output DOT graph
205 * `dflag=4' is equivalent to -dddd to follow -d/-dd/-ddd
206 * convention in tcpdump command line
207 */
208 dflag = 4;
209 #endif
210 infile = NULL;
211 Oflag = 1;
212 snaplen = 68;
213
214 if ((cp = strrchr(argv[0], '/')) != NULL)
215 program_name = cp + 1;
216 else
217 program_name = argv[0];
218
219 opterr = 0;
220 while ((op = getopt(argc, argv, "dF:m:Os:")) != -1) {
221 switch (op) {
222
223 case 'd':
224 ++dflag;
225 break;
226
227 case 'F':
228 infile = optarg;
229 break;
230
231 case 'O':
232 Oflag = 0;
233 break;
234
235 case 'm': {
236 in_addr_t addr;
237
238 addr = inet_addr(optarg);
239 if (addr == INADDR_NONE)
240 error("invalid netmask %s", optarg);
241 netmask = addr;
242 break;
243 }
244
245 case 's': {
246 char *end;
247
248 snaplen = strtol(optarg, &end, 0);
249 if (optarg == end || *end != '\0'
250 || snaplen < 0 || snaplen > 65535)
251 error("invalid snaplen %s", optarg);
252 else if (snaplen == 0)
253 snaplen = 65535;
254 break;
255 }
256
257 default:
258 usage();
259 /* NOTREACHED */
260 }
261 }
262
263 if (optind >= argc) {
264 usage();
265 /* NOTREACHED */
266 }
267
268 dlt = pcap_datalink_name_to_val(argv[optind]);
269 if (dlt < 0) {
270 dlt = (int)strtol(argv[optind], &p, 10);
271 if (p == argv[optind] || *p != '\0')
272 error("invalid data link type %s", argv[optind]);
273 }
274
275 if (infile)
276 cmdbuf = read_infile(infile);
277 else
278 cmdbuf = copy_argv(&argv[optind+1]);
279
280 pd = pcap_open_dead(dlt, snaplen);
281 if (pd == NULL)
282 error("Can't open fake pcap_t");
283
284 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
285 error("%s", pcap_geterr(pd));
286
287 if (!bpf_validate(fcode.bf_insns, fcode.bf_len))
288 warn("Filter doesn't pass validation");
289
290 #ifdef BDEBUG
291 // replace line feed with space
292 for (cp = cmdbuf; *cp != '\0'; ++cp) {
293 if (*cp == '\r' || *cp == '\n') {
294 *cp = ' ';
295 }
296 }
297 // only show machine code if BDEBUG defined, since dflag > 3
298 printf("machine codes for filter: %s\n", cmdbuf);
299 #endif
300
301 bpf_dump(&fcode, dflag);
302 pcap_close(pd);
303 exit(0);
304 }
305
306 static void
usage(void)307 usage(void)
308 {
309 (void)fprintf(stderr, "%s, with %s\n", program_name,
310 pcap_lib_version());
311 (void)fprintf(stderr,
312 "Usage: %s [-dO] [ -F file ] [ -m netmask] [ -s snaplen ] dlt [ expression ]\n",
313 program_name);
314 exit(1);
315 }
316