1 /*
2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
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 * packet filter subroutines for tcpdump
22 * Extraction/creation by Jeffrey Mogul, DECWRL
23 */
24
25 #include <config.h>
26
27 #include <sys/types.h>
28 #include <sys/time.h>
29 #include <sys/timeb.h>
30 #include <sys/socket.h>
31 #include <sys/file.h>
32 #include <sys/ioctl.h>
33 #include <net/pfilt.h>
34
35 struct mbuf;
36 struct rtentry;
37 #include <net/if.h>
38
39 #include <netinet/in.h>
40 #include <netinet/in_systm.h>
41 #include <netinet/ip.h>
42 #include <netinet/if_ether.h>
43 #include <netinet/ip_var.h>
44 #include <netinet/udp.h>
45 #include <netinet/udp_var.h>
46 #include <netinet/tcp.h>
47 #include <netinet/tcpip.h>
48
49 #include <errno.h>
50 #include <netdb.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55
56 /*
57 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
58 * native OS version, as we need various BPF ioctls from it.
59 */
60 #define PCAP_DONT_INCLUDE_PCAP_BPF_H
61 #include <net/bpf.h>
62
63 #include "pcap-int.h"
64
65 #ifdef HAVE_OS_PROTO_H
66 #include "os-proto.h"
67 #endif
68
69 /*
70 * FDDI packets are padded to make everything line up on a nice boundary.
71 */
72 #define PCAP_FDDIPAD 3
73
74 /*
75 * Private data for capturing on Ultrix and DEC OSF/1^WDigital UNIX^W^W
76 * Tru64 UNIX packetfilter devices.
77 */
78 struct pcap_pf {
79 int filtering_in_kernel; /* using kernel filter */
80 u_long TotPkts; /* can't overflow for 79 hrs on ether */
81 u_long TotAccepted; /* count accepted by filter */
82 u_long TotDrops; /* count of dropped packets */
83 long TotMissed; /* missed by i/f during this run */
84 long OrigMissed; /* missed by i/f before this run */
85 };
86
87 static int pcap_setfilter_pf(pcap_t *, struct bpf_program *);
88
89 /*
90 * BUFSPACE is the size in bytes of the packet read buffer. Most tcpdump
91 * applications aren't going to need more than 200 bytes of packet header
92 * and the read shouldn't return more packets than packetfilter's internal
93 * queue limit (bounded at 256).
94 */
95 #define BUFSPACE (200 * 256)
96
97 static int
pcap_read_pf(pcap_t * pc,int cnt,pcap_handler callback,u_char * user)98 pcap_read_pf(pcap_t *pc, int cnt, pcap_handler callback, u_char *user)
99 {
100 struct pcap_pf *pf = pc->priv;
101 register u_char *p, *bp;
102 register int cc, n, buflen, inc;
103 register struct enstamp *sp;
104 struct enstamp stamp;
105 register u_int pad;
106
107 again:
108 cc = pc->cc;
109 if (cc == 0) {
110 cc = read(pc->fd, (char *)pc->buffer + pc->offset, pc->bufsize);
111 if (cc < 0) {
112 if (errno == EWOULDBLOCK)
113 return (0);
114 if (errno == EINVAL &&
115 lseek(pc->fd, 0L, SEEK_CUR) + pc->bufsize < 0) {
116 /*
117 * Due to a kernel bug, after 2^31 bytes,
118 * the kernel file offset overflows and
119 * read fails with EINVAL. The lseek()
120 * to 0 will fix things.
121 */
122 (void)lseek(pc->fd, 0L, SEEK_SET);
123 goto again;
124 }
125 pcapint_fmt_errmsg_for_errno(pc->errbuf,
126 sizeof(pc->errbuf), errno, "pf read");
127 return (-1);
128 }
129 bp = (u_char *)pc->buffer + pc->offset;
130 } else
131 bp = pc->bp;
132 /*
133 * Loop through each packet.
134 *
135 * This assumes that a single buffer of packets will have
136 * <= INT_MAX packets, so the packet count doesn't overflow.
137 */
138 n = 0;
139 pad = pc->fddipad;
140 while (cc > 0) {
141 /*
142 * Has "pcap_breakloop()" been called?
143 * If so, return immediately - if we haven't read any
144 * packets, clear the flag and return -2 to indicate
145 * that we were told to break out of the loop, otherwise
146 * leave the flag set, so that the *next* call will break
147 * out of the loop without having read any packets, and
148 * return the number of packets we've processed so far.
149 */
150 if (pc->break_loop) {
151 if (n == 0) {
152 pc->break_loop = 0;
153 return (-2);
154 } else {
155 pc->cc = cc;
156 pc->bp = bp;
157 return (n);
158 }
159 }
160 if (cc < sizeof(*sp)) {
161 snprintf(pc->errbuf, sizeof(pc->errbuf),
162 "pf short read (%d)", cc);
163 return (-1);
164 }
165 if ((long)bp & 3) {
166 sp = &stamp;
167 memcpy((char *)sp, (char *)bp, sizeof(*sp));
168 } else
169 sp = (struct enstamp *)bp;
170 if (sp->ens_stamplen != sizeof(*sp)) {
171 snprintf(pc->errbuf, sizeof(pc->errbuf),
172 "pf short stamplen (%d)",
173 sp->ens_stamplen);
174 return (-1);
175 }
176
177 p = bp + sp->ens_stamplen;
178 buflen = sp->ens_count;
179 if (buflen > pc->snapshot)
180 buflen = pc->snapshot;
181
182 /* Calculate inc before possible pad update */
183 inc = ENALIGN(buflen + sp->ens_stamplen);
184 cc -= inc;
185 bp += inc;
186 pf->TotPkts++;
187 pf->TotDrops += sp->ens_dropped;
188 pf->TotMissed = sp->ens_ifoverflows;
189 if (pf->OrigMissed < 0)
190 pf->OrigMissed = pf->TotMissed;
191
192 /*
193 * Short-circuit evaluation: if using BPF filter
194 * in kernel, no need to do it now - we already know
195 * the packet passed the filter.
196 *
197 * Note: the filter code was generated assuming
198 * that pc->fddipad was the amount of padding
199 * before the header, as that's what's required
200 * in the kernel, so we run the filter before
201 * skipping that padding.
202 */
203 if (pf->filtering_in_kernel ||
204 pcapint_filter(pc->fcode.bf_insns, p, sp->ens_count, buflen)) {
205 struct pcap_pkthdr h;
206 pf->TotAccepted++;
207 h.ts = sp->ens_tstamp;
208 h.len = sp->ens_count - pad;
209 p += pad;
210 buflen -= pad;
211 h.caplen = buflen;
212 (*callback)(user, &h, p);
213 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
214 pc->cc = cc;
215 pc->bp = bp;
216 return (n);
217 }
218 }
219 }
220 pc->cc = 0;
221 return (n);
222 }
223
224 static int
pcap_inject_pf(pcap_t * p,const void * buf,int size)225 pcap_inject_pf(pcap_t *p, const void *buf, int size)
226 {
227 int ret;
228
229 ret = write(p->fd, buf, size);
230 if (ret == -1) {
231 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
232 errno, "send");
233 return (-1);
234 }
235 return (ret);
236 }
237
238 static int
pcap_stats_pf(pcap_t * p,struct pcap_stat * ps)239 pcap_stats_pf(pcap_t *p, struct pcap_stat *ps)
240 {
241 struct pcap_pf *pf = p->priv;
242
243 /*
244 * If packet filtering is being done in the kernel:
245 *
246 * "ps_recv" counts only packets that passed the filter.
247 * This does not include packets dropped because we
248 * ran out of buffer space. (XXX - perhaps it should,
249 * by adding "ps_drop" to "ps_recv", for compatibility
250 * with some other platforms. On the other hand, on
251 * some platforms "ps_recv" counts only packets that
252 * passed the filter, and on others it counts packets
253 * that didn't pass the filter....)
254 *
255 * "ps_drop" counts packets that passed the kernel filter
256 * (if any) but were dropped because the input queue was
257 * full.
258 *
259 * "ps_ifdrop" counts packets dropped by the network
260 * interface (regardless of whether they would have passed
261 * the input filter, of course).
262 *
263 * If packet filtering is not being done in the kernel:
264 *
265 * "ps_recv" counts only packets that passed the filter.
266 *
267 * "ps_drop" counts packets that were dropped because the
268 * input queue was full, regardless of whether they passed
269 * the userland filter.
270 *
271 * "ps_ifdrop" counts packets dropped by the network
272 * interface (regardless of whether they would have passed
273 * the input filter, of course).
274 *
275 * These statistics don't include packets not yet read from
276 * the kernel by libpcap, but they may include packets not
277 * yet read from libpcap by the application.
278 */
279 ps->ps_recv = pf->TotAccepted;
280 ps->ps_drop = pf->TotDrops;
281 ps->ps_ifdrop = pf->TotMissed - pf->OrigMissed;
282 return (0);
283 }
284
285 /*
286 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably
287 * don't get DLT_DOCSIS defined.
288 */
289 #ifndef DLT_DOCSIS
290 #define DLT_DOCSIS 143
291 #endif
292
293 static int
pcap_activate_pf(pcap_t * p)294 pcap_activate_pf(pcap_t *p)
295 {
296 struct pcap_pf *pf = p->priv;
297 short enmode;
298 int backlog = -1; /* request the most */
299 struct enfilter Filter;
300 struct endevp devparams;
301 int err;
302
303 /*
304 * Initially try a read/write open (to allow the inject
305 * method to work). If that fails due to permission
306 * issues, fall back to read-only. This allows a
307 * non-root user to be granted specific access to pcap
308 * capabilities via file permissions.
309 *
310 * XXX - we should have an API that has a flag that
311 * controls whether to open read-only or read-write,
312 * so that denial of permission to send (or inability
313 * to send, if sending packets isn't supported on
314 * the device in question) can be indicated at open
315 * time.
316 *
317 * XXX - we assume here that "pfopen()" does not, in fact, modify
318 * its argument, even though it takes a "char *" rather than a
319 * "const char *" as its first argument. That appears to be
320 * the case, at least on Digital UNIX 4.0.
321 *
322 * XXX - is there an error that means "no such device"? Is
323 * there one that means "that device doesn't support pf"?
324 */
325 p->fd = pfopen(p->opt.device, O_RDWR);
326 if (p->fd == -1 && errno == EACCES)
327 p->fd = pfopen(p->opt.device, O_RDONLY);
328 if (p->fd < 0) {
329 if (errno == EACCES) {
330 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
331 "pf open: %s: Permission denied\n"
332 "your system may not be properly configured; see the packetfilter(4) man page",
333 p->opt.device);
334 err = PCAP_ERROR_PERM_DENIED;
335 } else {
336 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
337 errno, "pf open: %s", p->opt.device);
338 err = PCAP_ERROR;
339 }
340 goto bad;
341 }
342
343 /*
344 * Turn a negative snapshot value (invalid), a snapshot value of
345 * 0 (unspecified), or a value bigger than the normal maximum
346 * value, into the maximum allowed value.
347 *
348 * If some application really *needs* a bigger snapshot
349 * length, we should just increase MAXIMUM_SNAPLEN.
350 */
351 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
352 p->snapshot = MAXIMUM_SNAPLEN;
353
354 pf->OrigMissed = -1;
355 enmode = ENTSTAMP|ENNONEXCL;
356 if (!p->opt.immediate)
357 enmode |= ENBATCH;
358 if (p->opt.promisc)
359 enmode |= ENPROMISC;
360 if (ioctl(p->fd, EIOCMBIS, (caddr_t)&enmode) < 0) {
361 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
362 errno, "EIOCMBIS");
363 err = PCAP_ERROR;
364 goto bad;
365 }
366 #ifdef ENCOPYALL
367 /* Try to set COPYALL mode so that we see packets to ourself */
368 enmode = ENCOPYALL;
369 (void)ioctl(p->fd, EIOCMBIS, (caddr_t)&enmode);/* OK if this fails */
370 #endif
371 /* set the backlog */
372 if (ioctl(p->fd, EIOCSETW, (caddr_t)&backlog) < 0) {
373 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
374 errno, "EIOCSETW");
375 err = PCAP_ERROR;
376 goto bad;
377 }
378 /* discover interface type */
379 if (ioctl(p->fd, EIOCDEVP, (caddr_t)&devparams) < 0) {
380 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
381 errno, "EIOCDEVP");
382 err = PCAP_ERROR;
383 goto bad;
384 }
385 /* HACK: to compile prior to Ultrix 4.2 */
386 #ifndef ENDT_FDDI
387 #define ENDT_FDDI 4
388 #endif
389 switch (devparams.end_dev_type) {
390
391 case ENDT_10MB:
392 p->linktype = DLT_EN10MB;
393 p->offset = 2;
394 /*
395 * This is (presumably) a real Ethernet capture; give it a
396 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
397 * that an application can let you choose it, in case you're
398 * capturing DOCSIS traffic that a Cisco Cable Modem
399 * Termination System is putting out onto an Ethernet (it
400 * doesn't put an Ethernet header onto the wire, it puts raw
401 * DOCSIS frames out on the wire inside the low-level
402 * Ethernet framing).
403 */
404 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
405 if (p->dlt_list == NULL) {
406 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
407 errno, "malloc");
408 err = PCAP_ERROR;
409 goto bad;
410 }
411 p->dlt_list[0] = DLT_EN10MB;
412 p->dlt_list[1] = DLT_DOCSIS;
413 p->dlt_count = 2;
414 break;
415
416 case ENDT_FDDI:
417 p->linktype = DLT_FDDI;
418 break;
419
420 #ifdef ENDT_SLIP
421 case ENDT_SLIP:
422 p->linktype = DLT_SLIP;
423 break;
424 #endif
425
426 #ifdef ENDT_PPP
427 case ENDT_PPP:
428 p->linktype = DLT_PPP;
429 break;
430 #endif
431
432 #ifdef ENDT_LOOPBACK
433 case ENDT_LOOPBACK:
434 /*
435 * It appears to use Ethernet framing, at least on
436 * Digital UNIX 4.0.
437 */
438 p->linktype = DLT_EN10MB;
439 p->offset = 2;
440 break;
441 #endif
442
443 #ifdef ENDT_TRN
444 case ENDT_TRN:
445 p->linktype = DLT_IEEE802;
446 break;
447 #endif
448
449 default:
450 /*
451 * XXX - what about ENDT_IEEE802? The pfilt.h header
452 * file calls this "IEEE 802 networks (non-Ethernet)",
453 * but that doesn't specify a specific link layer type;
454 * it could be 802.4, or 802.5 (except that 802.5 is
455 * ENDT_TRN), or 802.6, or 802.11, or.... That's why
456 * DLT_IEEE802 was hijacked to mean Token Ring in various
457 * BSDs, and why we went along with that hijacking.
458 *
459 * XXX - what about ENDT_HDLC and ENDT_NULL?
460 * Presumably, as ENDT_OTHER is just "Miscellaneous
461 * framing", there's not much we can do, as that
462 * doesn't specify a particular type of header.
463 */
464 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
465 "unknown data-link type %u", devparams.end_dev_type);
466 err = PCAP_ERROR;
467 goto bad;
468 }
469 /* set truncation */
470 if (p->linktype == DLT_FDDI) {
471 p->fddipad = PCAP_FDDIPAD;
472
473 /* packetfilter includes the padding in the snapshot */
474 p->snapshot += PCAP_FDDIPAD;
475 } else
476 p->fddipad = 0;
477 if (ioctl(p->fd, EIOCTRUNCATE, (caddr_t)&p->snapshot) < 0) {
478 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
479 errno, "EIOCTRUNCATE");
480 err = PCAP_ERROR;
481 goto bad;
482 }
483 /* accept all packets */
484 memset(&Filter, 0, sizeof(Filter));
485 Filter.enf_Priority = 37; /* anything > 2 */
486 Filter.enf_FilterLen = 0; /* means "always true" */
487 if (ioctl(p->fd, EIOCSETF, (caddr_t)&Filter) < 0) {
488 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
489 errno, "EIOCSETF");
490 err = PCAP_ERROR;
491 goto bad;
492 }
493
494 if (p->opt.timeout != 0) {
495 struct timeval timeout;
496 timeout.tv_sec = p->opt.timeout / 1000;
497 timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
498 if (ioctl(p->fd, EIOCSRTIMEOUT, (caddr_t)&timeout) < 0) {
499 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
500 errno, "EIOCSRTIMEOUT");
501 err = PCAP_ERROR;
502 goto bad;
503 }
504 }
505
506 p->bufsize = BUFSPACE;
507 p->buffer = malloc(p->bufsize + p->offset);
508 if (p->buffer == NULL) {
509 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
510 errno, "malloc");
511 err = PCAP_ERROR;
512 goto bad;
513 }
514
515 /*
516 * "select()" and "poll()" work on packetfilter devices.
517 */
518 p->selectable_fd = p->fd;
519
520 p->read_op = pcap_read_pf;
521 p->inject_op = pcap_inject_pf;
522 p->setfilter_op = pcap_setfilter_pf;
523 p->setdirection_op = NULL; /* Not implemented. */
524 p->set_datalink_op = NULL; /* can't change data link type */
525 p->getnonblock_op = pcapint_getnonblock_fd;
526 p->setnonblock_op = pcapint_setnonblock_fd;
527 p->stats_op = pcap_stats_pf;
528
529 return (0);
530 bad:
531 pcapint_cleanup_live_common(p);
532 return (err);
533 }
534
535 pcap_t *
pcapint_create_interface(const char * device _U_,char * ebuf)536 pcapint_create_interface(const char *device _U_, char *ebuf)
537 {
538 pcap_t *p;
539
540 p = PCAP_CREATE_COMMON(ebuf, struct pcap_pf);
541 if (p == NULL)
542 return (NULL);
543
544 p->activate_op = pcap_activate_pf;
545 return (p);
546 }
547
548 /*
549 * XXX - is there an error from pfopen() that means "no such device"?
550 * Is there one that means "that device doesn't support pf"?
551 */
552 static int
can_be_bound(const char * name _U_)553 can_be_bound(const char *name _U_)
554 {
555 return (1);
556 }
557
558 static int
get_if_flags(const char * name _U_,bpf_u_int32 * flags _U_,char * errbuf _U_)559 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
560 {
561 /*
562 * Nothing we can do other than mark loopback devices as "the
563 * connected/disconnected status doesn't apply".
564 *
565 * XXX - is there a way to find out whether an adapter has
566 * something plugged into it?
567 */
568 if (*flags & PCAP_IF_LOOPBACK) {
569 /*
570 * Loopback devices aren't wireless, and "connected"/
571 * "disconnected" doesn't apply to them.
572 */
573 *flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
574 return (0);
575 }
576 return (0);
577 }
578
579 int
pcapint_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)580 pcapint_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
581 {
582 return (pcapint_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
583 get_if_flags));
584 }
585
586 static int
pcap_setfilter_pf(pcap_t * p,struct bpf_program * fp)587 pcap_setfilter_pf(pcap_t *p, struct bpf_program *fp)
588 {
589 struct pcap_pf *pf = p->priv;
590 struct bpf_version bv;
591
592 /*
593 * See if BIOCVERSION works. If not, we assume the kernel doesn't
594 * support BPF-style filters (it's not documented in the bpf(7)
595 * or packetfilter(7) man pages, but the code used to fail if
596 * BIOCSETF worked but BIOCVERSION didn't, and I've seen it do
597 * kernel filtering in DU 4.0, so presumably BIOCVERSION works
598 * there, at least).
599 */
600 if (ioctl(p->fd, BIOCVERSION, (caddr_t)&bv) >= 0) {
601 /*
602 * OK, we have the version of the BPF interpreter;
603 * is it the same major version as us, and the same
604 * or better minor version?
605 */
606 if (bv.bv_major == BPF_MAJOR_VERSION &&
607 bv.bv_minor >= BPF_MINOR_VERSION) {
608 /*
609 * Yes. Try to install the filter.
610 */
611 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) {
612 pcapint_fmt_errmsg_for_errno(p->errbuf,
613 sizeof(p->errbuf), errno, "BIOCSETF");
614 return (-1);
615 }
616
617 /*
618 * OK, that succeeded. We're doing filtering in
619 * the kernel. (We assume we don't have a
620 * userland filter installed - that'd require
621 * a previous version check to have failed but
622 * this one to succeed.)
623 *
624 * XXX - this message should be supplied to the
625 * application as a warning of some sort,
626 * except that if it's a GUI application, it's
627 * not clear that it should be displayed in
628 * a window to annoy the user.
629 */
630 fprintf(stderr, "tcpdump: Using kernel BPF filter\n");
631 pf->filtering_in_kernel = 1;
632
633 /*
634 * Discard any previously-received packets,
635 * as they might have passed whatever filter
636 * was formerly in effect, but might not pass
637 * this filter (BIOCSETF discards packets buffered
638 * in the kernel, so you can lose packets in any
639 * case).
640 */
641 p->cc = 0;
642 return (0);
643 }
644
645 /*
646 * We can't use the kernel's BPF interpreter; don't give
647 * up, just log a message and be inefficient.
648 *
649 * XXX - this should really be supplied to the application
650 * as a warning of some sort.
651 */
652 fprintf(stderr,
653 "tcpdump: Requires BPF language %d.%d or higher; kernel is %d.%d\n",
654 BPF_MAJOR_VERSION, BPF_MINOR_VERSION,
655 bv.bv_major, bv.bv_minor);
656 }
657
658 /*
659 * We couldn't do filtering in the kernel; do it in userland.
660 */
661 if (pcapint_install_bpf_program(p, fp) < 0)
662 return (-1);
663
664 /*
665 * XXX - this message should be supplied by the application as
666 * a warning of some sort.
667 */
668 fprintf(stderr, "tcpdump: Filtering in user process\n");
669 pf->filtering_in_kernel = 0;
670 return (0);
671 }
672
673 /*
674 * Libpcap version string.
675 */
676 const char *
pcap_lib_version(void)677 pcap_lib_version(void)
678 {
679 return (PCAP_VERSION_STRING);
680 }
681