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 /*
25  * This doesn't actually test libpcap itself; it tests whether
26  * valgrind properly handles the APIs libpcap uses.  If it doesn't,
27  * we end up getting patches submitted to "fix" references that
28  * valgrind claims are being made to uninitialized data, when, in
29  * fact, the OS isn't making any such references - or we get
30  * valgrind *not* detecting *actual* incorrect references.
31  *
32  * Both BPF and Linux socket filters aren't handled correctly
33  * by some versions of valgrind.  See valgrind bug 318203 for
34  * Linux:
35  *
36  *	https://bugs.kde.org/show_bug.cgi?id=318203
37  *
38  * and valgrind bug 312989 for macOS:
39  *
40  *	https://bugs.kde.org/show_bug.cgi?id=312989
41  *
42  * The fixes for both of those are checked into the official valgrind
43  * repository.
44  *
45  * The unofficial FreeBSD port has similar issues to the official macOS
46  * port, for similar reasons.
47  */
48 #ifndef lint
49 static const char copyright[] _U_ =
50     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
51 The Regents of the University of California.  All rights reserved.\n";
52 #endif
53 
54 #ifdef HAVE_CONFIG_H
55 #include <config.h>
56 #endif
57 
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <stdarg.h>
62 #include <limits.h>
63 #include <unistd.h>
64 #include <fcntl.h>
65 #include <errno.h>
66 #include <arpa/inet.h>
67 #include <sys/types.h>
68 #include <sys/stat.h>
69 
70 #include "pcap/funcattrs.h"
71 
72 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(_AIX) || defined(sun)
73 /* OS with BPF - use BPF */
74 #define USE_BPF
75 #elif defined(linux)
76 /* Linux - use socket filters */
77 #define USE_SOCKET_FILTERS
78 #else
79 #error "Unknown platform or platform that doesn't support Valgrind"
80 #endif
81 
82 #if defined(USE_BPF)
83 
84 #include <sys/ioctl.h>
85 #include <net/bpf.h>
86 
87 /*
88  * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
89  * native OS version, as we're going to be doing our own ioctls to
90  * make sure that, in the uninitialized-data tests, the filters aren't
91  * checked by libpcap before being handed to BPF.
92  */
93 #define PCAP_DONT_INCLUDE_PCAP_BPF_H
94 
95 #elif defined(USE_SOCKET_FILTERS)
96 
97 #include <sys/socket.h>
98 #include <linux/types.h>
99 #include <linux/filter.h>
100 
101 #endif
102 
103 /*
104  * Squelch a warning.
105  *
106  * We include system headers to be able to directly set the filter to
107  * a program with uninitialized content, to make sure what we're testing
108  * is Valgrind's checking of the system call to set the filter, and we
109  * also include <pcap.h> to open the device in the first place, and that
110  * means that we may get collisions between their definitions of
111  * BPF_STMT and BPF_JUMP - and do, in fact, get them on Linux (the
112  * definitions may be semantically the same, but that's not sufficient to
113  * avoid the warnings, as the preprocessor doesn't know that u_short is
114  * just unsigned short).
115  *
116  * So we undefine BPF_STMT and BPF_JUMP to avoid the warning.
117  */
118 #undef BPF_STMT
119 #undef BPF_JUMP
120 #include <pcap.h>
121 
122 static char *program_name;
123 
124 /* Forwards */
125 static void PCAP_NORETURN usage(void);
126 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
127 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
128 
129 /*
130  * On Windows, we need to open the file in binary mode, so that
131  * we get all the bytes specified by the size we get from "fstat()".
132  * On UNIX, that's not necessary.  O_BINARY is defined on Windows;
133  * we define it as 0 if it's not defined, so it does nothing.
134  */
135 #ifndef O_BINARY
136 #define O_BINARY	0
137 #endif
138 
139 static char *
140 read_infile(char *fname)
141 {
142 	register int i, fd, cc;
143 	register char *cp;
144 	struct stat buf;
145 
146 	fd = open(fname, O_RDONLY|O_BINARY);
147 	if (fd < 0)
148 		error("can't open %s: %s", fname, pcap_strerror(errno));
149 
150 	if (fstat(fd, &buf) < 0)
151 		error("can't stat %s: %s", fname, pcap_strerror(errno));
152 
153 	/*
154 	 * _read(), on Windows, has an unsigned int byte count and an
155 	 * int return value, so we can't handle a file bigger than
156 	 * INT_MAX - 1 bytes (and have no reason to do so; a filter *that*
157 	 * big will take forever to compile).  (The -1 is for the '\0' at
158 	 * the end of the string.)
159 	 */
160 	if (buf.st_size > INT_MAX - 1)
161 		error("%s is larger than %d bytes; that's too large", fname,
162 		    INT_MAX - 1);
163 	cp = malloc((u_int)buf.st_size + 1);
164 	if (cp == NULL)
165 		error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
166 			fname, pcap_strerror(errno));
167 	cc = (int)read(fd, cp, (u_int)buf.st_size);
168 	if (cc < 0)
169 		error("read %s: %s", fname, pcap_strerror(errno));
170 	if (cc != buf.st_size)
171 		error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
172 
173 	close(fd);
174 	/* replace "# comment" with spaces */
175 	for (i = 0; i < cc; i++) {
176 		if (cp[i] == '#')
177 			while (i < cc && cp[i] != '\n')
178 				cp[i++] = ' ';
179 	}
180 	cp[cc] = '\0';
181 	return (cp);
182 }
183 
184 /* VARARGS */
185 static void
186 error(const char *fmt, ...)
187 {
188 	va_list ap;
189 
190 	(void)fprintf(stderr, "%s: ", program_name);
191 	va_start(ap, fmt);
192 	(void)vfprintf(stderr, fmt, ap);
193 	va_end(ap);
194 	if (*fmt) {
195 		fmt += strlen(fmt);
196 		if (fmt[-1] != '\n')
197 			(void)fputc('\n', stderr);
198 	}
199 	exit(1);
200 	/* NOTREACHED */
201 }
202 
203 /* VARARGS */
204 static void
205 warning(const char *fmt, ...)
206 {
207 	va_list ap;
208 
209 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
210 	va_start(ap, fmt);
211 	(void)vfprintf(stderr, fmt, ap);
212 	va_end(ap);
213 	if (*fmt) {
214 		fmt += strlen(fmt);
215 		if (fmt[-1] != '\n')
216 			(void)fputc('\n', stderr);
217 	}
218 }
219 
220 /*
221  * Copy arg vector into a new buffer, concatenating arguments with spaces.
222  */
223 static char *
224 copy_argv(register char **argv)
225 {
226 	register char **p;
227 	register size_t len = 0;
228 	char *buf;
229 	char *src, *dst;
230 
231 	p = argv;
232 	if (*p == 0)
233 		return 0;
234 
235 	while (*p)
236 		len += strlen(*p++) + 1;
237 
238 	buf = (char *)malloc(len);
239 	if (buf == NULL)
240 		error("copy_argv: malloc");
241 
242 	p = argv;
243 	dst = buf;
244 	while ((src = *p++) != NULL) {
245 		while ((*dst++ = *src++) != '\0')
246 			;
247 		dst[-1] = ' ';
248 	}
249 	dst[-1] = '\0';
250 
251 	return buf;
252 }
253 
254 #define INSN_COUNT	17
255 
256 int
257 main(int argc, char **argv)
258 {
259 	char *cp, *device;
260 	int op;
261 	int dorfmon, useactivate;
262 	char ebuf[PCAP_ERRBUF_SIZE];
263 	char *infile;
264 	const char *cmdbuf;
265 	pcap_if_t *devlist;
266 	pcap_t *pd;
267 	int status = 0;
268 	int pcap_fd;
269 #if defined(USE_BPF)
270 	struct bpf_program bad_fcode;
271 	struct bpf_insn uninitialized[INSN_COUNT];
272 #elif defined(USE_SOCKET_FILTERS)
273 	struct sock_fprog bad_fcode;
274 	struct sock_filter uninitialized[INSN_COUNT];
275 #endif
276 	struct bpf_program fcode;
277 
278 	device = NULL;
279 	dorfmon = 0;
280 	useactivate = 0;
281 	infile = NULL;
282 
283 	if ((cp = strrchr(argv[0], '/')) != NULL)
284 		program_name = cp + 1;
285 	else
286 		program_name = argv[0];
287 
288 	opterr = 0;
289 	while ((op = getopt(argc, argv, "aF:i:I")) != -1) {
290 		switch (op) {
291 
292 		case 'a':
293 			useactivate = 1;
294 			break;
295 
296 		case 'F':
297 			infile = optarg;
298 			break;
299 
300 		case 'i':
301 			device = optarg;
302 			break;
303 
304 		case 'I':
305 			dorfmon = 1;
306 			useactivate = 1;	/* required for rfmon */
307 			break;
308 
309 		default:
310 			usage();
311 			/* NOTREACHED */
312 		}
313 	}
314 
315 	if (device == NULL) {
316 		/*
317 		 * No interface specified; get whatever pcap_lookupdev()
318 		 * finds.
319 		 */
320 		if (pcap_findalldevs(&devlist, ebuf) == -1)
321 			error("%s", ebuf);
322 		if (devlist == NULL)
323 			error("no interfaces available for capture");
324 		device = strdup(devlist->name);
325 		pcap_freealldevs(devlist);
326 	}
327 
328 	if (infile != NULL) {
329 		/*
330 		 * Filter specified with "-F" and a file containing
331 		 * a filter.
332 		 */
333 		cmdbuf = read_infile(infile);
334 	} else {
335 		if (optind < argc) {
336 			/*
337 			 * Filter specified with arguments on the
338 			 * command line.
339 			 */
340 			cmdbuf = copy_argv(&argv[optind+1]);
341 		} else {
342 			/*
343 			 * No filter specified; use an empty string, which
344 			 * compiles to an "accept all" filter.
345 			 */
346 			cmdbuf = "";
347 		}
348 	}
349 
350 	if (useactivate) {
351 		pd = pcap_create(device, ebuf);
352 		if (pd == NULL)
353 			error("%s: pcap_create() failed: %s", device, ebuf);
354 		status = pcap_set_snaplen(pd, 65535);
355 		if (status != 0)
356 			error("%s: pcap_set_snaplen failed: %s",
357 			    device, pcap_statustostr(status));
358 		status = pcap_set_promisc(pd, 1);
359 		if (status != 0)
360 			error("%s: pcap_set_promisc failed: %s",
361 			    device, pcap_statustostr(status));
362 		if (dorfmon) {
363 			status = pcap_set_rfmon(pd, 1);
364 			if (status != 0)
365 				error("%s: pcap_set_rfmon failed: %s",
366 				    device, pcap_statustostr(status));
367 		}
368 		status = pcap_set_timeout(pd, 1000);
369 		if (status != 0)
370 			error("%s: pcap_set_timeout failed: %s",
371 			    device, pcap_statustostr(status));
372 		status = pcap_activate(pd);
373 		if (status < 0) {
374 			/*
375 			 * pcap_activate() failed.
376 			 */
377 			error("%s: %s\n(%s)", device,
378 			    pcap_statustostr(status), pcap_geterr(pd));
379 		} else if (status > 0) {
380 			/*
381 			 * pcap_activate() succeeded, but it's warning us
382 			 * of a problem it had.
383 			 */
384 			warning("%s: %s\n(%s)", device,
385 			    pcap_statustostr(status), pcap_geterr(pd));
386 		}
387 	} else {
388 		*ebuf = '\0';
389 		pd = pcap_open_live(device, 65535, 1, 1000, ebuf);
390 		if (pd == NULL)
391 			error("%s", ebuf);
392 		else if (*ebuf)
393 			warning("%s", ebuf);
394 	}
395 
396 	pcap_fd = pcap_fileno(pd);
397 
398 	/*
399 	 * Try setting a filter with an uninitialized bpf_program
400 	 * structure.  This should cause valgrind to report a
401 	 * problem.
402 	 *
403 	 * We don't check for errors, because it could get an
404 	 * error due to a bad pointer or count.
405 	 */
406 #if defined(USE_BPF)
407 	ioctl(pcap_fd, BIOCSETF, &bad_fcode);
408 #elif defined(USE_SOCKET_FILTERS)
409 	setsockopt(pcap_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bad_fcode,
410 	    sizeof(bad_fcode));
411 #endif
412 
413 	/*
414 	 * Try setting a filter with an initialized bpf_program
415 	 * structure that points to an uninitialized program.
416 	 * That should also cause valgrind to report a problem.
417 	 *
418 	 * We don't check for errors, because it could get an
419 	 * error due to a bad pointer or count.
420 	 */
421 #if defined(USE_BPF)
422 	bad_fcode.bf_len = INSN_COUNT;
423 	bad_fcode.bf_insns = uninitialized;
424 	ioctl(pcap_fd, BIOCSETF, &bad_fcode);
425 #elif defined(USE_SOCKET_FILTERS)
426 	bad_fcode.len = INSN_COUNT;
427 	bad_fcode.filter = uninitialized;
428 	setsockopt(pcap_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bad_fcode,
429 	    sizeof(bad_fcode));
430 #endif
431 
432 	/*
433 	 * Now compile a filter and set the filter with that.
434 	 * That should *not* cause valgrind to report a
435 	 * problem.
436 	 */
437 	if (pcap_compile(pd, &fcode, cmdbuf, 1, 0) < 0)
438 		error("can't compile filter: %s", pcap_geterr(pd));
439 	if (pcap_setfilter(pd, &fcode) < 0)
440 		error("can't set filter: %s", pcap_geterr(pd));
441 
442 	pcap_close(pd);
443 	exit(status < 0 ? 1 : 0);
444 }
445 
446 static void
447 usage(void)
448 {
449 	(void)fprintf(stderr, "%s, with %s\n", program_name,
450 	    pcap_lib_version());
451 	(void)fprintf(stderr,
452 	    "Usage: %s [-aI] [ -F file ] [ -i interface ] [ expression ]\n",
453 	    program_name);
454 	exit(1);
455 }
456