1 /* $NetBSD: filtertest.c,v 1.3 2015/03/31 21:39:43 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 #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 <sys/cdefs.h>
31 __RCSID("$NetBSD: filtertest.c,v 1.3 2015/03/31 21:39:43 christos Exp $");
32
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36
37 #include <pcap.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <stdarg.h>
42 #include <unistd.h>
43 #include <fcntl.h>
44 #include <errno.h>
45 #include <arpa/inet.h>
46 #include <sys/types.h>
47 #include <sys/stat.h>
48
49 #ifndef HAVE___ATTRIBUTE__
50 #define __attribute__(x)
51 #endif
52
53 static char *program_name;
54
55 /* Forwards */
56 static void usage(void) __attribute__((noreturn));
57 static void error(const char *, ...)
58 __attribute__((noreturn, format (printf, 1, 2)));
59 static void warn(const char *, ...)
60 __attribute__((format (printf, 1, 2)));
61
62 extern int optind;
63 extern int opterr;
64 extern char *optarg;
65 #ifdef BDEBUG
66 int dflag;
67 #endif
68
69 /*
70 * On Windows, we need to open the file in binary mode, so that
71 * we get all the bytes specified by the size we get from "fstat()".
72 * On UNIX, that's not necessary. O_BINARY is defined on Windows;
73 * we define it as 0 if it's not defined, so it does nothing.
74 */
75 #ifndef O_BINARY
76 #define O_BINARY 0
77 #endif
78
79 static char *
read_infile(char * fname)80 read_infile(char *fname)
81 {
82 register int i, fd, cc;
83 register char *cp;
84 struct stat buf;
85
86 fd = open(fname, O_RDONLY|O_BINARY);
87 if (fd < 0)
88 error("can't open %s: %s", fname, pcap_strerror(errno));
89
90 if (fstat(fd, &buf) < 0)
91 error("can't stat %s: %s", fname, pcap_strerror(errno));
92
93 cp = malloc((u_int)buf.st_size + 1);
94 if (cp == NULL)
95 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
96 fname, pcap_strerror(errno));
97 cc = read(fd, cp, (u_int)buf.st_size);
98 if (cc < 0)
99 error("read %s: %s", fname, pcap_strerror(errno));
100 if (cc != buf.st_size)
101 error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
102
103 close(fd);
104 /* replace "# comment" with spaces */
105 for (i = 0; i < cc; i++) {
106 if (cp[i] == '#')
107 while (i < cc && cp[i] != '\n')
108 cp[i++] = ' ';
109 }
110 cp[cc] = '\0';
111 return (cp);
112 }
113
114 /* VARARGS */
115 static void
error(const char * fmt,...)116 error(const char *fmt, ...)
117 {
118 va_list ap;
119
120 (void)fprintf(stderr, "%s: ", program_name);
121 va_start(ap, fmt);
122 (void)vfprintf(stderr, fmt, ap);
123 va_end(ap);
124 if (*fmt) {
125 fmt += strlen(fmt);
126 if (fmt[-1] != '\n')
127 (void)fputc('\n', stderr);
128 }
129 exit(1);
130 /* NOTREACHED */
131 }
132
133 /* VARARGS */
134 static void
warn(const char * fmt,...)135 warn(const char *fmt, ...)
136 {
137 va_list ap;
138
139 (void)fprintf(stderr, "%s: WARNING: ", program_name);
140 va_start(ap, fmt);
141 (void)vfprintf(stderr, fmt, ap);
142 va_end(ap);
143 if (*fmt) {
144 fmt += strlen(fmt);
145 if (fmt[-1] != '\n')
146 (void)fputc('\n', stderr);
147 }
148 }
149
150 /*
151 * Copy arg vector into a new buffer, concatenating arguments with spaces.
152 */
153 static char *
copy_argv(register char ** argv)154 copy_argv(register char **argv)
155 {
156 register char **p;
157 register u_int len = 0;
158 char *buf;
159 char *src, *dst;
160
161 p = argv;
162 if (*p == 0)
163 return 0;
164
165 while (*p)
166 len += strlen(*p++) + 1;
167
168 buf = (char *)malloc(len);
169 if (buf == NULL)
170 error("copy_argv: malloc");
171
172 p = argv;
173 dst = buf;
174 while ((src = *p++) != NULL) {
175 while ((*dst++ = *src++) != '\0')
176 ;
177 dst[-1] = ' ';
178 }
179 dst[-1] = '\0';
180
181 return buf;
182 }
183
184 int
main(int argc,char ** argv)185 main(int argc, char **argv)
186 {
187 char *cp;
188 int op;
189 #ifndef BDEBUG
190 int dflag;
191 #endif
192 char *infile;
193 int Oflag;
194 long snaplen;
195 char *p;
196 int dlt;
197 bpf_u_int32 netmask = PCAP_NETMASK_UNKNOWN;
198 char *cmdbuf;
199 pcap_t *pd;
200 struct bpf_program fcode;
201
202 #ifdef WIN32
203 if(wsockinit() != 0) return 1;
204 #endif /* WIN32 */
205
206 #ifndef BDEBUG
207 dflag = 1;
208 #else
209 /* if optimizer debugging is enabled, output DOT graph
210 * `dflag=4' is equivalent to -dddd to follow -d/-dd/-ddd
211 * convention in tcpdump command line
212 */
213 dflag = 4;
214 #endif
215 infile = NULL;
216 Oflag = 1;
217 snaplen = 68;
218
219 if ((cp = strrchr(argv[0], '/')) != NULL)
220 program_name = cp + 1;
221 else
222 program_name = argv[0];
223
224 opterr = 0;
225 while ((op = getopt(argc, argv, "dF:m:Os:")) != -1) {
226 switch (op) {
227
228 case 'd':
229 ++dflag;
230 break;
231
232 case 'F':
233 infile = optarg;
234 break;
235
236 case 'O':
237 Oflag = 0;
238 break;
239
240 case 'm': {
241 in_addr_t addr;
242
243 addr = inet_addr(optarg);
244 if (addr == INADDR_NONE)
245 error("invalid netmask %s", optarg);
246 netmask = addr;
247 break;
248 }
249
250 case 's': {
251 char *end;
252
253 snaplen = strtol(optarg, &end, 0);
254 if (optarg == end || *end != '\0'
255 || snaplen < 0 || snaplen > 65535)
256 error("invalid snaplen %s", optarg);
257 else if (snaplen == 0)
258 snaplen = 65535;
259 break;
260 }
261
262 default:
263 usage();
264 /* NOTREACHED */
265 }
266 }
267
268 if (optind >= argc) {
269 usage();
270 /* NOTREACHED */
271 }
272
273 dlt = pcap_datalink_name_to_val(argv[optind]);
274 if (dlt < 0) {
275 dlt = (int)strtol(argv[optind], &p, 10);
276 if (p == argv[optind] || *p != '\0')
277 error("invalid data link type %s", argv[optind]);
278 }
279
280 if (infile)
281 cmdbuf = read_infile(infile);
282 else
283 cmdbuf = copy_argv(&argv[optind+1]);
284
285 pd = pcap_open_dead(dlt, snaplen);
286 if (pd == NULL)
287 error("Can't open fake pcap_t");
288
289 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
290 error("%s", pcap_geterr(pd));
291
292 if (!bpf_validate(fcode.bf_insns, fcode.bf_len))
293 warn("Filter doesn't pass validation");
294
295 #ifdef BDEBUG
296 // replace line feed with space
297 for (cp = cmdbuf; *cp != '\0'; ++cp) {
298 if (*cp == '\r' || *cp == '\n') {
299 *cp = ' ';
300 }
301 }
302 // only show machine code if BDEBUG defined, since dflag > 3
303 printf("machine codes for filter: %s\n", cmdbuf);
304 #endif
305
306 bpf_dump(&fcode, dflag);
307 pcap_close(pd);
308 exit(0);
309 }
310
311 static void
usage(void)312 usage(void)
313 {
314 (void)fprintf(stderr, "%s, with %s\n", program_name,
315 pcap_lib_version());
316 (void)fprintf(stderr,
317 "Usage: %s [-dO] [ -F file ] [ -m netmask] [ -s snaplen ] dlt [ expression ]\n",
318 program_name);
319 exit(1);
320 }
321