FreeBSD/Linux Kernel Cross Reference
sys/net/bpf.c
1 /*-
2 * Copyright (c) 1990, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from the Stanford/CMU enet packet filter,
6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
8 * Berkeley Laboratory.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)bpf.c 8.4 (Berkeley) 1/9/95
35 *
36 * $FreeBSD: src/sys/net/bpf.c,v 1.133.2.10 2005/09/26 13:12:01 andre Exp $
37 */
38
39 #include "opt_bpf.h"
40 #include "opt_mac.h"
41 #include "opt_netgraph.h"
42
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/conf.h>
47 #include <sys/mac.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/time.h>
51 #include <sys/proc.h>
52 #include <sys/signalvar.h>
53 #include <sys/filio.h>
54 #include <sys/sockio.h>
55 #include <sys/ttycom.h>
56 #include <sys/filedesc.h>
57
58 #include <sys/event.h>
59 #include <sys/file.h>
60 #include <sys/poll.h>
61 #include <sys/proc.h>
62
63 #include <sys/socket.h>
64 #include <sys/vnode.h>
65
66 #include <net/if.h>
67 #include <net/bpf.h>
68 #include <net/bpfdesc.h>
69
70 #include <netinet/in.h>
71 #include <netinet/if_ether.h>
72 #include <sys/kernel.h>
73 #include <sys/sysctl.h>
74
75 static MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
76
77 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
78
79 #define PRINET 26 /* interruptible */
80
81 /*
82 * The default read buffer size is patchable.
83 */
84 static int bpf_bufsize = 4096;
85 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
86 &bpf_bufsize, 0, "");
87 static int bpf_maxbufsize = BPF_MAXBUFSIZE;
88 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
89 &bpf_maxbufsize, 0, "");
90
91 /*
92 * bpf_iflist is a list of BPF interface structures, each corresponding to a
93 * specific DLT. The same network interface might have several BPF interface
94 * structures registered by different layers in the stack (i.e., 802.11
95 * frames, ethernet frames, etc).
96 */
97 static LIST_HEAD(, bpf_if) bpf_iflist;
98 static struct mtx bpf_mtx; /* bpf global lock */
99
100 static int bpf_allocbufs(struct bpf_d *);
101 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
102 static void bpf_detachd(struct bpf_d *d);
103 static void bpf_freed(struct bpf_d *);
104 static void bpf_mcopy(const void *, void *, size_t);
105 static int bpf_movein(struct uio *, int,
106 struct mbuf **, struct sockaddr *, int *);
107 static int bpf_setif(struct bpf_d *, struct ifreq *);
108 static void bpf_timed_out(void *);
109 static __inline void
110 bpf_wakeup(struct bpf_d *);
111 static void catchpacket(struct bpf_d *, u_char *, u_int,
112 u_int, void (*)(const void *, void *, size_t));
113 static void reset_d(struct bpf_d *);
114 static int bpf_setf(struct bpf_d *, struct bpf_program *);
115 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
116 static int bpf_setdlt(struct bpf_d *, u_int);
117 static void filt_bpfdetach(struct knote *);
118 static int filt_bpfread(struct knote *, long);
119
120 static d_open_t bpfopen;
121 static d_close_t bpfclose;
122 static d_read_t bpfread;
123 static d_write_t bpfwrite;
124 static d_ioctl_t bpfioctl;
125 static d_poll_t bpfpoll;
126 static d_kqfilter_t bpfkqfilter;
127
128 static struct cdevsw bpf_cdevsw = {
129 .d_version = D_VERSION,
130 .d_flags = D_NEEDGIANT,
131 .d_open = bpfopen,
132 .d_close = bpfclose,
133 .d_read = bpfread,
134 .d_write = bpfwrite,
135 .d_ioctl = bpfioctl,
136 .d_poll = bpfpoll,
137 .d_name = "bpf",
138 .d_kqfilter = bpfkqfilter,
139 };
140
141 static struct filterops bpfread_filtops =
142 { 1, NULL, filt_bpfdetach, filt_bpfread };
143
144 static int
145 bpf_movein(uio, linktype, mp, sockp, datlen)
146 struct uio *uio;
147 int linktype, *datlen;
148 struct mbuf **mp;
149 struct sockaddr *sockp;
150 {
151 struct mbuf *m;
152 int error;
153 int len;
154 int hlen;
155
156 /*
157 * Build a sockaddr based on the data link layer type.
158 * We do this at this level because the ethernet header
159 * is copied directly into the data field of the sockaddr.
160 * In the case of SLIP, there is no header and the packet
161 * is forwarded as is.
162 * Also, we are careful to leave room at the front of the mbuf
163 * for the link level header.
164 */
165 switch (linktype) {
166
167 case DLT_SLIP:
168 sockp->sa_family = AF_INET;
169 hlen = 0;
170 break;
171
172 case DLT_EN10MB:
173 sockp->sa_family = AF_UNSPEC;
174 /* XXX Would MAXLINKHDR be better? */
175 hlen = ETHER_HDR_LEN;
176 break;
177
178 case DLT_FDDI:
179 sockp->sa_family = AF_IMPLINK;
180 hlen = 0;
181 break;
182
183 case DLT_RAW:
184 case DLT_NULL:
185 sockp->sa_family = AF_UNSPEC;
186 hlen = 0;
187 break;
188
189 case DLT_ATM_RFC1483:
190 /*
191 * en atm driver requires 4-byte atm pseudo header.
192 * though it isn't standard, vpi:vci needs to be
193 * specified anyway.
194 */
195 sockp->sa_family = AF_UNSPEC;
196 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
197 break;
198
199 case DLT_PPP:
200 sockp->sa_family = AF_UNSPEC;
201 hlen = 4; /* This should match PPP_HDRLEN */
202 break;
203
204 default:
205 return (EIO);
206 }
207
208 len = uio->uio_resid;
209 *datlen = len - hlen;
210 if ((unsigned)len > MCLBYTES)
211 return (EIO);
212
213 if (len > MHLEN) {
214 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR);
215 } else {
216 MGETHDR(m, M_TRYWAIT, MT_DATA);
217 }
218 if (m == NULL)
219 return (ENOBUFS);
220 m->m_pkthdr.len = m->m_len = len;
221 m->m_pkthdr.rcvif = NULL;
222 *mp = m;
223
224 /*
225 * Make room for link header.
226 */
227 if (hlen != 0) {
228 m->m_pkthdr.len -= hlen;
229 m->m_len -= hlen;
230 #if BSD >= 199103
231 m->m_data += hlen; /* XXX */
232 #else
233 m->m_off += hlen;
234 #endif
235 error = uiomove(sockp->sa_data, hlen, uio);
236 if (error)
237 goto bad;
238 }
239 error = uiomove(mtod(m, void *), len - hlen, uio);
240 if (!error)
241 return (0);
242 bad:
243 m_freem(m);
244 return (error);
245 }
246
247 /*
248 * Attach file to the bpf interface, i.e. make d listen on bp.
249 */
250 static void
251 bpf_attachd(d, bp)
252 struct bpf_d *d;
253 struct bpf_if *bp;
254 {
255 /*
256 * Point d at bp, and add d to the interface's list of listeners.
257 * Finally, point the driver's bpf cookie at the interface so
258 * it will divert packets to bpf.
259 */
260 BPFIF_LOCK(bp);
261 d->bd_bif = bp;
262 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
263
264 *bp->bif_driverp = bp;
265 BPFIF_UNLOCK(bp);
266 }
267
268 /*
269 * Detach a file from its interface.
270 */
271 static void
272 bpf_detachd(d)
273 struct bpf_d *d;
274 {
275 int error;
276 struct bpf_if *bp;
277 struct ifnet *ifp;
278
279 bp = d->bd_bif;
280 BPFIF_LOCK(bp);
281 BPFD_LOCK(d);
282 ifp = d->bd_bif->bif_ifp;
283
284 /*
285 * Remove d from the interface's descriptor list.
286 */
287 LIST_REMOVE(d, bd_next);
288
289 /*
290 * Let the driver know that there are no more listeners.
291 */
292 if (LIST_EMPTY(&bp->bif_dlist))
293 *bp->bif_driverp = NULL;
294
295 d->bd_bif = NULL;
296 BPFD_UNLOCK(d);
297 BPFIF_UNLOCK(bp);
298
299 /*
300 * Check if this descriptor had requested promiscuous mode.
301 * If so, turn it off.
302 */
303 if (d->bd_promisc) {
304 d->bd_promisc = 0;
305 error = ifpromisc(ifp, 0);
306 if (error != 0 && error != ENXIO) {
307 /*
308 * ENXIO can happen if a pccard is unplugged
309 * Something is really wrong if we were able to put
310 * the driver into promiscuous mode, but can't
311 * take it out.
312 */
313 if_printf(bp->bif_ifp,
314 "bpf_detach: ifpromisc failed (%d)\n", error);
315 }
316 }
317 }
318
319 /*
320 * Open ethernet device. Returns ENXIO for illegal minor device number,
321 * EBUSY if file is open by another process.
322 */
323 /* ARGSUSED */
324 static int
325 bpfopen(dev, flags, fmt, td)
326 struct cdev *dev;
327 int flags;
328 int fmt;
329 struct thread *td;
330 {
331 struct bpf_d *d;
332
333 mtx_lock(&bpf_mtx);
334 d = dev->si_drv1;
335 /*
336 * Each minor can be opened by only one process. If the requested
337 * minor is in use, return EBUSY.
338 */
339 if (d != NULL) {
340 mtx_unlock(&bpf_mtx);
341 return (EBUSY);
342 }
343 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */
344 mtx_unlock(&bpf_mtx);
345
346 if ((dev->si_flags & SI_NAMED) == 0)
347 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600,
348 "bpf%d", dev2unit(dev));
349 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
350 dev->si_drv1 = d;
351 d->bd_bufsize = bpf_bufsize;
352 d->bd_sig = SIGIO;
353 d->bd_seesent = 1;
354 #ifdef MAC
355 mac_init_bpfdesc(d);
356 mac_create_bpfdesc(td->td_ucred, d);
357 #endif
358 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF);
359 callout_init(&d->bd_callout, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
360 knlist_init(&d->bd_sel.si_note, &d->bd_mtx);
361
362 return (0);
363 }
364
365 /*
366 * Close the descriptor by detaching it from its interface,
367 * deallocating its buffers, and marking it free.
368 */
369 /* ARGSUSED */
370 static int
371 bpfclose(dev, flags, fmt, td)
372 struct cdev *dev;
373 int flags;
374 int fmt;
375 struct thread *td;
376 {
377 struct bpf_d *d = dev->si_drv1;
378
379 BPFD_LOCK(d);
380 if (d->bd_state == BPF_WAITING)
381 callout_stop(&d->bd_callout);
382 d->bd_state = BPF_IDLE;
383 BPFD_UNLOCK(d);
384 funsetown(&d->bd_sigio);
385 mtx_lock(&bpf_mtx);
386 if (d->bd_bif)
387 bpf_detachd(d);
388 mtx_unlock(&bpf_mtx);
389 selwakeuppri(&d->bd_sel, PRINET);
390 #ifdef MAC
391 mac_destroy_bpfdesc(d);
392 #endif /* MAC */
393 knlist_destroy(&d->bd_sel.si_note);
394 bpf_freed(d);
395 dev->si_drv1 = NULL;
396 free(d, M_BPF);
397
398 return (0);
399 }
400
401
402 /*
403 * Rotate the packet buffers in descriptor d. Move the store buffer
404 * into the hold slot, and the free buffer into the store slot.
405 * Zero the length of the new store buffer.
406 */
407 #define ROTATE_BUFFERS(d) \
408 (d)->bd_hbuf = (d)->bd_sbuf; \
409 (d)->bd_hlen = (d)->bd_slen; \
410 (d)->bd_sbuf = (d)->bd_fbuf; \
411 (d)->bd_slen = 0; \
412 (d)->bd_fbuf = NULL;
413 /*
414 * bpfread - read next chunk of packets from buffers
415 */
416 static int
417 bpfread(dev, uio, ioflag)
418 struct cdev *dev;
419 struct uio *uio;
420 int ioflag;
421 {
422 struct bpf_d *d = dev->si_drv1;
423 int timed_out;
424 int error;
425
426 /*
427 * Restrict application to use a buffer the same size as
428 * as kernel buffers.
429 */
430 if (uio->uio_resid != d->bd_bufsize)
431 return (EINVAL);
432
433 BPFD_LOCK(d);
434 if (d->bd_state == BPF_WAITING)
435 callout_stop(&d->bd_callout);
436 timed_out = (d->bd_state == BPF_TIMED_OUT);
437 d->bd_state = BPF_IDLE;
438 /*
439 * If the hold buffer is empty, then do a timed sleep, which
440 * ends when the timeout expires or when enough packets
441 * have arrived to fill the store buffer.
442 */
443 while (d->bd_hbuf == NULL) {
444 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
445 /*
446 * A packet(s) either arrived since the previous
447 * read or arrived while we were asleep.
448 * Rotate the buffers and return what's here.
449 */
450 ROTATE_BUFFERS(d);
451 break;
452 }
453
454 /*
455 * No data is available, check to see if the bpf device
456 * is still pointed at a real interface. If not, return
457 * ENXIO so that the userland process knows to rebind
458 * it before using it again.
459 */
460 if (d->bd_bif == NULL) {
461 BPFD_UNLOCK(d);
462 return (ENXIO);
463 }
464
465 if (ioflag & IO_NDELAY) {
466 BPFD_UNLOCK(d);
467 return (EWOULDBLOCK);
468 }
469 error = msleep(d, &d->bd_mtx, PRINET|PCATCH,
470 "bpf", d->bd_rtout);
471 if (error == EINTR || error == ERESTART) {
472 BPFD_UNLOCK(d);
473 return (error);
474 }
475 if (error == EWOULDBLOCK) {
476 /*
477 * On a timeout, return what's in the buffer,
478 * which may be nothing. If there is something
479 * in the store buffer, we can rotate the buffers.
480 */
481 if (d->bd_hbuf)
482 /*
483 * We filled up the buffer in between
484 * getting the timeout and arriving
485 * here, so we don't need to rotate.
486 */
487 break;
488
489 if (d->bd_slen == 0) {
490 BPFD_UNLOCK(d);
491 return (0);
492 }
493 ROTATE_BUFFERS(d);
494 break;
495 }
496 }
497 /*
498 * At this point, we know we have something in the hold slot.
499 */
500 BPFD_UNLOCK(d);
501
502 /*
503 * Move data from hold buffer into user space.
504 * We know the entire buffer is transferred since
505 * we checked above that the read buffer is bpf_bufsize bytes.
506 */
507 error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
508
509 BPFD_LOCK(d);
510 d->bd_fbuf = d->bd_hbuf;
511 d->bd_hbuf = NULL;
512 d->bd_hlen = 0;
513 BPFD_UNLOCK(d);
514
515 return (error);
516 }
517
518
519 /*
520 * If there are processes sleeping on this descriptor, wake them up.
521 */
522 static __inline void
523 bpf_wakeup(d)
524 struct bpf_d *d;
525 {
526 if (d->bd_state == BPF_WAITING) {
527 callout_stop(&d->bd_callout);
528 d->bd_state = BPF_IDLE;
529 }
530 wakeup(d);
531 if (d->bd_async && d->bd_sig && d->bd_sigio)
532 pgsigio(&d->bd_sigio, d->bd_sig, 0);
533
534 selwakeuppri(&d->bd_sel, PRINET);
535 KNOTE_LOCKED(&d->bd_sel.si_note, 0);
536 }
537
538 static void
539 bpf_timed_out(arg)
540 void *arg;
541 {
542 struct bpf_d *d = (struct bpf_d *)arg;
543
544 BPFD_LOCK(d);
545 if (d->bd_state == BPF_WAITING) {
546 d->bd_state = BPF_TIMED_OUT;
547 if (d->bd_slen != 0)
548 bpf_wakeup(d);
549 }
550 BPFD_UNLOCK(d);
551 }
552
553 static int
554 bpfwrite(dev, uio, ioflag)
555 struct cdev *dev;
556 struct uio *uio;
557 int ioflag;
558 {
559 struct bpf_d *d = dev->si_drv1;
560 struct ifnet *ifp;
561 struct mbuf *m;
562 int error;
563 struct sockaddr dst;
564 int datlen;
565
566 if (d->bd_bif == NULL)
567 return (ENXIO);
568
569 ifp = d->bd_bif->bif_ifp;
570
571 if (uio->uio_resid == 0)
572 return (0);
573
574 bzero(&dst, sizeof(dst));
575 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
576 if (error)
577 return (error);
578
579 if (datlen > ifp->if_mtu) {
580 m_freem(m);
581 return (EMSGSIZE);
582 }
583
584 if (d->bd_hdrcmplt)
585 dst.sa_family = pseudo_AF_HDRCMPLT;
586
587 #ifdef MAC
588 BPFD_LOCK(d);
589 mac_create_mbuf_from_bpfdesc(d, m);
590 BPFD_UNLOCK(d);
591 #endif
592 NET_LOCK_GIANT();
593 error = (*ifp->if_output)(ifp, m, &dst, NULL);
594 NET_UNLOCK_GIANT();
595 /*
596 * The driver frees the mbuf.
597 */
598 return (error);
599 }
600
601 /*
602 * Reset a descriptor by flushing its packet buffer and clearing the
603 * receive and drop counts.
604 */
605 static void
606 reset_d(d)
607 struct bpf_d *d;
608 {
609
610 mtx_assert(&d->bd_mtx, MA_OWNED);
611 if (d->bd_hbuf) {
612 /* Free the hold buffer. */
613 d->bd_fbuf = d->bd_hbuf;
614 d->bd_hbuf = NULL;
615 }
616 d->bd_slen = 0;
617 d->bd_hlen = 0;
618 d->bd_rcount = 0;
619 d->bd_dcount = 0;
620 }
621
622 /*
623 * FIONREAD Check for read packet available.
624 * SIOCGIFADDR Get interface address - convenient hook to driver.
625 * BIOCGBLEN Get buffer len [for read()].
626 * BIOCSETF Set ethernet read filter.
627 * BIOCFLUSH Flush read packet buffer.
628 * BIOCPROMISC Put interface into promiscuous mode.
629 * BIOCGDLT Get link layer type.
630 * BIOCGETIF Get interface name.
631 * BIOCSETIF Set interface.
632 * BIOCSRTIMEOUT Set read timeout.
633 * BIOCGRTIMEOUT Get read timeout.
634 * BIOCGSTATS Get packet stats.
635 * BIOCIMMEDIATE Set immediate mode.
636 * BIOCVERSION Get filter language version.
637 * BIOCGHDRCMPLT Get "header already complete" flag
638 * BIOCSHDRCMPLT Set "header already complete" flag
639 * BIOCGSEESENT Get "see packets sent" flag
640 * BIOCSSEESENT Set "see packets sent" flag
641 */
642 /* ARGSUSED */
643 static int
644 bpfioctl(dev, cmd, addr, flags, td)
645 struct cdev *dev;
646 u_long cmd;
647 caddr_t addr;
648 int flags;
649 struct thread *td;
650 {
651 struct bpf_d *d = dev->si_drv1;
652 int error = 0;
653
654 BPFD_LOCK(d);
655 if (d->bd_state == BPF_WAITING)
656 callout_stop(&d->bd_callout);
657 d->bd_state = BPF_IDLE;
658 BPFD_UNLOCK(d);
659
660 switch (cmd) {
661
662 default:
663 error = EINVAL;
664 break;
665
666 /*
667 * Check for read packet available.
668 */
669 case FIONREAD:
670 {
671 int n;
672
673 BPFD_LOCK(d);
674 n = d->bd_slen;
675 if (d->bd_hbuf)
676 n += d->bd_hlen;
677 BPFD_UNLOCK(d);
678
679 *(int *)addr = n;
680 break;
681 }
682
683 case SIOCGIFADDR:
684 {
685 struct ifnet *ifp;
686
687 if (d->bd_bif == NULL)
688 error = EINVAL;
689 else {
690 ifp = d->bd_bif->bif_ifp;
691 error = (*ifp->if_ioctl)(ifp, cmd, addr);
692 }
693 break;
694 }
695
696 /*
697 * Get buffer len [for read()].
698 */
699 case BIOCGBLEN:
700 *(u_int *)addr = d->bd_bufsize;
701 break;
702
703 /*
704 * Set buffer length.
705 */
706 case BIOCSBLEN:
707 if (d->bd_bif != NULL)
708 error = EINVAL;
709 else {
710 u_int size = *(u_int *)addr;
711
712 if (size > bpf_maxbufsize)
713 *(u_int *)addr = size = bpf_maxbufsize;
714 else if (size < BPF_MINBUFSIZE)
715 *(u_int *)addr = size = BPF_MINBUFSIZE;
716 d->bd_bufsize = size;
717 }
718 break;
719
720 /*
721 * Set link layer read filter.
722 */
723 case BIOCSETF:
724 error = bpf_setf(d, (struct bpf_program *)addr);
725 break;
726
727 /*
728 * Flush read packet buffer.
729 */
730 case BIOCFLUSH:
731 BPFD_LOCK(d);
732 reset_d(d);
733 BPFD_UNLOCK(d);
734 break;
735
736 /*
737 * Put interface into promiscuous mode.
738 */
739 case BIOCPROMISC:
740 if (d->bd_bif == NULL) {
741 /*
742 * No interface attached yet.
743 */
744 error = EINVAL;
745 break;
746 }
747 if (d->bd_promisc == 0) {
748 mtx_lock(&Giant);
749 error = ifpromisc(d->bd_bif->bif_ifp, 1);
750 mtx_unlock(&Giant);
751 if (error == 0)
752 d->bd_promisc = 1;
753 }
754 break;
755
756 /*
757 * Get current data link type.
758 */
759 case BIOCGDLT:
760 if (d->bd_bif == NULL)
761 error = EINVAL;
762 else
763 *(u_int *)addr = d->bd_bif->bif_dlt;
764 break;
765
766 /*
767 * Get a list of supported data link types.
768 */
769 case BIOCGDLTLIST:
770 if (d->bd_bif == NULL)
771 error = EINVAL;
772 else
773 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
774 break;
775
776 /*
777 * Set data link type.
778 */
779 case BIOCSDLT:
780 if (d->bd_bif == NULL)
781 error = EINVAL;
782 else
783 error = bpf_setdlt(d, *(u_int *)addr);
784 break;
785
786 /*
787 * Get interface name.
788 */
789 case BIOCGETIF:
790 if (d->bd_bif == NULL)
791 error = EINVAL;
792 else {
793 struct ifnet *const ifp = d->bd_bif->bif_ifp;
794 struct ifreq *const ifr = (struct ifreq *)addr;
795
796 strlcpy(ifr->ifr_name, ifp->if_xname,
797 sizeof(ifr->ifr_name));
798 }
799 break;
800
801 /*
802 * Set interface.
803 */
804 case BIOCSETIF:
805 error = bpf_setif(d, (struct ifreq *)addr);
806 break;
807
808 /*
809 * Set read timeout.
810 */
811 case BIOCSRTIMEOUT:
812 {
813 struct timeval *tv = (struct timeval *)addr;
814
815 /*
816 * Subtract 1 tick from tvtohz() since this isn't
817 * a one-shot timer.
818 */
819 if ((error = itimerfix(tv)) == 0)
820 d->bd_rtout = tvtohz(tv) - 1;
821 break;
822 }
823
824 /*
825 * Get read timeout.
826 */
827 case BIOCGRTIMEOUT:
828 {
829 struct timeval *tv = (struct timeval *)addr;
830
831 tv->tv_sec = d->bd_rtout / hz;
832 tv->tv_usec = (d->bd_rtout % hz) * tick;
833 break;
834 }
835
836 /*
837 * Get packet stats.
838 */
839 case BIOCGSTATS:
840 {
841 struct bpf_stat *bs = (struct bpf_stat *)addr;
842
843 bs->bs_recv = d->bd_rcount;
844 bs->bs_drop = d->bd_dcount;
845 break;
846 }
847
848 /*
849 * Set immediate mode.
850 */
851 case BIOCIMMEDIATE:
852 d->bd_immediate = *(u_int *)addr;
853 break;
854
855 case BIOCVERSION:
856 {
857 struct bpf_version *bv = (struct bpf_version *)addr;
858
859 bv->bv_major = BPF_MAJOR_VERSION;
860 bv->bv_minor = BPF_MINOR_VERSION;
861 break;
862 }
863
864 /*
865 * Get "header already complete" flag
866 */
867 case BIOCGHDRCMPLT:
868 *(u_int *)addr = d->bd_hdrcmplt;
869 break;
870
871 /*
872 * Set "header already complete" flag
873 */
874 case BIOCSHDRCMPLT:
875 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
876 break;
877
878 /*
879 * Get "see sent packets" flag
880 */
881 case BIOCGSEESENT:
882 *(u_int *)addr = d->bd_seesent;
883 break;
884
885 /*
886 * Set "see sent packets" flag
887 */
888 case BIOCSSEESENT:
889 d->bd_seesent = *(u_int *)addr;
890 break;
891
892 case FIONBIO: /* Non-blocking I/O */
893 break;
894
895 case FIOASYNC: /* Send signal on receive packets */
896 d->bd_async = *(int *)addr;
897 break;
898
899 case FIOSETOWN:
900 error = fsetown(*(int *)addr, &d->bd_sigio);
901 break;
902
903 case FIOGETOWN:
904 *(int *)addr = fgetown(&d->bd_sigio);
905 break;
906
907 /* This is deprecated, FIOSETOWN should be used instead. */
908 case TIOCSPGRP:
909 error = fsetown(-(*(int *)addr), &d->bd_sigio);
910 break;
911
912 /* This is deprecated, FIOGETOWN should be used instead. */
913 case TIOCGPGRP:
914 *(int *)addr = -fgetown(&d->bd_sigio);
915 break;
916
917 case BIOCSRSIG: /* Set receive signal */
918 {
919 u_int sig;
920
921 sig = *(u_int *)addr;
922
923 if (sig >= NSIG)
924 error = EINVAL;
925 else
926 d->bd_sig = sig;
927 break;
928 }
929 case BIOCGRSIG:
930 *(u_int *)addr = d->bd_sig;
931 break;
932 }
933 return (error);
934 }
935
936 /*
937 * Set d's packet filter program to fp. If this file already has a filter,
938 * free it and replace it. Returns EINVAL for bogus requests.
939 */
940 static int
941 bpf_setf(d, fp)
942 struct bpf_d *d;
943 struct bpf_program *fp;
944 {
945 struct bpf_insn *fcode, *old;
946 u_int flen, size;
947
948 if (fp->bf_insns == NULL) {
949 if (fp->bf_len != 0)
950 return (EINVAL);
951 BPFD_LOCK(d);
952 old = d->bd_filter;
953 d->bd_filter = NULL;
954 reset_d(d);
955 BPFD_UNLOCK(d);
956 if (old != NULL)
957 free((caddr_t)old, M_BPF);
958 return (0);
959 }
960 flen = fp->bf_len;
961 if (flen > BPF_MAXINSNS)
962 return (EINVAL);
963
964 size = flen * sizeof(*fp->bf_insns);
965 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK);
966 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
967 bpf_validate(fcode, (int)flen)) {
968 BPFD_LOCK(d);
969 old = d->bd_filter;
970 d->bd_filter = fcode;
971 reset_d(d);
972 BPFD_UNLOCK(d);
973 if (old != NULL)
974 free((caddr_t)old, M_BPF);
975
976 return (0);
977 }
978 free((caddr_t)fcode, M_BPF);
979 return (EINVAL);
980 }
981
982 /*
983 * Detach a file from its current interface (if attached at all) and attach
984 * to the interface indicated by the name stored in ifr.
985 * Return an errno or 0.
986 */
987 static int
988 bpf_setif(d, ifr)
989 struct bpf_d *d;
990 struct ifreq *ifr;
991 {
992 struct bpf_if *bp;
993 int error;
994 struct ifnet *theywant;
995
996 theywant = ifunit(ifr->ifr_name);
997 if (theywant == NULL)
998 return ENXIO;
999
1000 /*
1001 * Look through attached interfaces for the named one.
1002 */
1003 mtx_lock(&bpf_mtx);
1004 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
1005 struct ifnet *ifp = bp->bif_ifp;
1006
1007 if (ifp == NULL || ifp != theywant)
1008 continue;
1009 /* skip additional entry */
1010 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf)
1011 continue;
1012
1013 mtx_unlock(&bpf_mtx);
1014 /*
1015 * We found the requested interface.
1016 * If it's not up, return an error.
1017 * Allocate the packet buffers if we need to.
1018 * If we're already attached to requested interface,
1019 * just flush the buffer.
1020 */
1021 if ((ifp->if_flags & IFF_UP) == 0)
1022 return (ENETDOWN);
1023
1024 if (d->bd_sbuf == NULL) {
1025 error = bpf_allocbufs(d);
1026 if (error != 0)
1027 return (error);
1028 }
1029 if (bp != d->bd_bif) {
1030 if (d->bd_bif)
1031 /*
1032 * Detach if attached to something else.
1033 */
1034 bpf_detachd(d);
1035
1036 bpf_attachd(d, bp);
1037 }
1038 BPFD_LOCK(d);
1039 reset_d(d);
1040 BPFD_UNLOCK(d);
1041 return (0);
1042 }
1043 mtx_unlock(&bpf_mtx);
1044 /* Not found. */
1045 return (ENXIO);
1046 }
1047
1048 /*
1049 * Support for select() and poll() system calls
1050 *
1051 * Return true iff the specific operation will not block indefinitely.
1052 * Otherwise, return false but make a note that a selwakeup() must be done.
1053 */
1054 static int
1055 bpfpoll(dev, events, td)
1056 struct cdev *dev;
1057 int events;
1058 struct thread *td;
1059 {
1060 struct bpf_d *d;
1061 int revents;
1062
1063 d = dev->si_drv1;
1064 if (d->bd_bif == NULL)
1065 return (ENXIO);
1066
1067 revents = events & (POLLOUT | POLLWRNORM);
1068 BPFD_LOCK(d);
1069 if (events & (POLLIN | POLLRDNORM)) {
1070 if (bpf_ready(d))
1071 revents |= events & (POLLIN | POLLRDNORM);
1072 else {
1073 selrecord(td, &d->bd_sel);
1074 /* Start the read timeout if necessary. */
1075 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1076 callout_reset(&d->bd_callout, d->bd_rtout,
1077 bpf_timed_out, d);
1078 d->bd_state = BPF_WAITING;
1079 }
1080 }
1081 }
1082 BPFD_UNLOCK(d);
1083 return (revents);
1084 }
1085
1086 /*
1087 * Support for kevent() system call. Register EVFILT_READ filters and
1088 * reject all others.
1089 */
1090 int
1091 bpfkqfilter(dev, kn)
1092 struct cdev *dev;
1093 struct knote *kn;
1094 {
1095 struct bpf_d *d = (struct bpf_d *)dev->si_drv1;
1096
1097 if (kn->kn_filter != EVFILT_READ)
1098 return (1);
1099
1100 kn->kn_fop = &bpfread_filtops;
1101 kn->kn_hook = d;
1102 knlist_add(&d->bd_sel.si_note, kn, 0);
1103
1104 return (0);
1105 }
1106
1107 static void
1108 filt_bpfdetach(kn)
1109 struct knote *kn;
1110 {
1111 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1112
1113 knlist_remove(&d->bd_sel.si_note, kn, 0);
1114 }
1115
1116 static int
1117 filt_bpfread(kn, hint)
1118 struct knote *kn;
1119 long hint;
1120 {
1121 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1122 int ready;
1123
1124 BPFD_LOCK_ASSERT(d);
1125 ready = bpf_ready(d);
1126 if (ready) {
1127 kn->kn_data = d->bd_slen;
1128 if (d->bd_hbuf)
1129 kn->kn_data += d->bd_hlen;
1130 }
1131 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1132 callout_reset(&d->bd_callout, d->bd_rtout,
1133 bpf_timed_out, d);
1134 d->bd_state = BPF_WAITING;
1135 }
1136
1137 return (ready);
1138 }
1139
1140 /*
1141 * Incoming linkage from device drivers. Process the packet pkt, of length
1142 * pktlen, which is stored in a contiguous buffer. The packet is parsed
1143 * by each process' filter, and if accepted, stashed into the corresponding
1144 * buffer.
1145 */
1146 void
1147 bpf_tap(bp, pkt, pktlen)
1148 struct bpf_if *bp;
1149 u_char *pkt;
1150 u_int pktlen;
1151 {
1152 struct bpf_d *d;
1153 u_int slen;
1154
1155 /*
1156 * Lockless read to avoid cost of locking the interface if there are
1157 * no descriptors attached.
1158 */
1159 if (LIST_EMPTY(&bp->bif_dlist))
1160 return;
1161
1162 BPFIF_LOCK(bp);
1163 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1164 BPFD_LOCK(d);
1165 ++d->bd_rcount;
1166 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
1167 if (slen != 0) {
1168 #ifdef MAC
1169 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
1170 #endif
1171 catchpacket(d, pkt, pktlen, slen, bcopy);
1172 }
1173 BPFD_UNLOCK(d);
1174 }
1175 BPFIF_UNLOCK(bp);
1176 }
1177
1178 /*
1179 * Copy data from an mbuf chain into a buffer. This code is derived
1180 * from m_copydata in sys/uipc_mbuf.c.
1181 */
1182 static void
1183 bpf_mcopy(src_arg, dst_arg, len)
1184 const void *src_arg;
1185 void *dst_arg;
1186 size_t len;
1187 {
1188 const struct mbuf *m;
1189 u_int count;
1190 u_char *dst;
1191
1192 m = src_arg;
1193 dst = dst_arg;
1194 while (len > 0) {
1195 if (m == NULL)
1196 panic("bpf_mcopy");
1197 count = min(m->m_len, len);
1198 bcopy(mtod(m, void *), dst, count);
1199 m = m->m_next;
1200 dst += count;
1201 len -= count;
1202 }
1203 }
1204
1205 /*
1206 * Incoming linkage from device drivers, when packet is in an mbuf chain.
1207 */
1208 void
1209 bpf_mtap(bp, m)
1210 struct bpf_if *bp;
1211 struct mbuf *m;
1212 {
1213 struct bpf_d *d;
1214 u_int pktlen, slen;
1215
1216 /*
1217 * Lockless read to avoid cost of locking the interface if there are
1218 * no descriptors attached.
1219 */
1220 if (LIST_EMPTY(&bp->bif_dlist))
1221 return;
1222
1223 pktlen = m_length(m, NULL);
1224
1225 BPFIF_LOCK(bp);
1226 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1227 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1228 continue;
1229 BPFD_LOCK(d);
1230 ++d->bd_rcount;
1231 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
1232 if (slen != 0)
1233 #ifdef MAC
1234 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
1235 #endif
1236 catchpacket(d, (u_char *)m, pktlen, slen,
1237 bpf_mcopy);
1238 BPFD_UNLOCK(d);
1239 }
1240 BPFIF_UNLOCK(bp);
1241 }
1242
1243 /*
1244 * Incoming linkage from device drivers, when packet is in
1245 * an mbuf chain and to be prepended by a contiguous header.
1246 */
1247 void
1248 bpf_mtap2(bp, data, dlen, m)
1249 struct bpf_if *bp;
1250 void *data;
1251 u_int dlen;
1252 struct mbuf *m;
1253 {
1254 struct mbuf mb;
1255 struct bpf_d *d;
1256 u_int pktlen, slen;
1257
1258 /*
1259 * Lockless read to avoid cost of locking the interface if there are
1260 * no descriptors attached.
1261 */
1262 if (LIST_EMPTY(&bp->bif_dlist))
1263 return;
1264
1265 pktlen = m_length(m, NULL);
1266 /*
1267 * Craft on-stack mbuf suitable for passing to bpf_filter.
1268 * Note that we cut corners here; we only setup what's
1269 * absolutely needed--this mbuf should never go anywhere else.
1270 */
1271 mb.m_next = m;
1272 mb.m_data = data;
1273 mb.m_len = dlen;
1274 pktlen += dlen;
1275
1276 BPFIF_LOCK(bp);
1277 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1278 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1279 continue;
1280 BPFD_LOCK(d);
1281 ++d->bd_rcount;
1282 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0);
1283 if (slen != 0)
1284 #ifdef MAC
1285 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
1286 #endif
1287 catchpacket(d, (u_char *)&mb, pktlen, slen,
1288 bpf_mcopy);
1289 BPFD_UNLOCK(d);
1290 }
1291 BPFIF_UNLOCK(bp);
1292 }
1293
1294 /*
1295 * Move the packet data from interface memory (pkt) into the
1296 * store buffer. "cpfn" is the routine called to do the actual data
1297 * transfer. bcopy is passed in to copy contiguous chunks, while
1298 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1299 * pkt is really an mbuf.
1300 */
1301 static void
1302 catchpacket(d, pkt, pktlen, snaplen, cpfn)
1303 struct bpf_d *d;
1304 u_char *pkt;
1305 u_int pktlen, snaplen;
1306 void (*cpfn)(const void *, void *, size_t);
1307 {
1308 struct bpf_hdr *hp;
1309 int totlen, curlen;
1310 int hdrlen = d->bd_bif->bif_hdrlen;
1311 int do_wakeup = 0;
1312
1313 /*
1314 * Figure out how many bytes to move. If the packet is
1315 * greater or equal to the snapshot length, transfer that
1316 * much. Otherwise, transfer the whole packet (unless
1317 * we hit the buffer size limit).
1318 */
1319 totlen = hdrlen + min(snaplen, pktlen);
1320 if (totlen > d->bd_bufsize)
1321 totlen = d->bd_bufsize;
1322
1323 /*
1324 * Round up the end of the previous packet to the next longword.
1325 */
1326 curlen = BPF_WORDALIGN(d->bd_slen);
1327 if (curlen + totlen > d->bd_bufsize) {
1328 /*
1329 * This packet will overflow the storage buffer.
1330 * Rotate the buffers if we can, then wakeup any
1331 * pending reads.
1332 */
1333 if (d->bd_fbuf == NULL) {
1334 /*
1335 * We haven't completed the previous read yet,
1336 * so drop the packet.
1337 */
1338 ++d->bd_dcount;
1339 return;
1340 }
1341 ROTATE_BUFFERS(d);
1342 do_wakeup = 1;
1343 curlen = 0;
1344 }
1345 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
1346 /*
1347 * Immediate mode is set, or the read timeout has
1348 * already expired during a select call. A packet
1349 * arrived, so the reader should be woken up.
1350 */
1351 do_wakeup = 1;
1352
1353 /*
1354 * Append the bpf header.
1355 */
1356 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1357 microtime(&hp->bh_tstamp);
1358 hp->bh_datalen = pktlen;
1359 hp->bh_hdrlen = hdrlen;
1360 /*
1361 * Copy the packet data into the store buffer and update its length.
1362 */
1363 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1364 d->bd_slen = curlen + totlen;
1365
1366 if (do_wakeup)
1367 bpf_wakeup(d);
1368 }
1369
1370 /*
1371 * Initialize all nonzero fields of a descriptor.
1372 */
1373 static int
1374 bpf_allocbufs(d)
1375 struct bpf_d *d;
1376 {
1377 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1378 if (d->bd_fbuf == NULL)
1379 return (ENOBUFS);
1380
1381 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1382 if (d->bd_sbuf == NULL) {
1383 free(d->bd_fbuf, M_BPF);
1384 return (ENOBUFS);
1385 }
1386 d->bd_slen = 0;
1387 d->bd_hlen = 0;
1388 return (0);
1389 }
1390
1391 /*
1392 * Free buffers currently in use by a descriptor.
1393 * Called on close.
1394 */
1395 static void
1396 bpf_freed(d)
1397 struct bpf_d *d;
1398 {
1399 /*
1400 * We don't need to lock out interrupts since this descriptor has
1401 * been detached from its interface and it yet hasn't been marked
1402 * free.
1403 */
1404 if (d->bd_sbuf != NULL) {
1405 free(d->bd_sbuf, M_BPF);
1406 if (d->bd_hbuf != NULL)
1407 free(d->bd_hbuf, M_BPF);
1408 if (d->bd_fbuf != NULL)
1409 free(d->bd_fbuf, M_BPF);
1410 }
1411 if (d->bd_filter)
1412 free((caddr_t)d->bd_filter, M_BPF);
1413 mtx_destroy(&d->bd_mtx);
1414 }
1415
1416 /*
1417 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the
1418 * fixed size of the link header (variable length headers not yet supported).
1419 */
1420 void
1421 bpfattach(ifp, dlt, hdrlen)
1422 struct ifnet *ifp;
1423 u_int dlt, hdrlen;
1424 {
1425
1426 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
1427 }
1428
1429 /*
1430 * Attach an interface to bpf. ifp is a pointer to the structure
1431 * defining the interface to be attached, dlt is the link layer type,
1432 * and hdrlen is the fixed size of the link header (variable length
1433 * headers are not yet supporrted).
1434 */
1435 void
1436 bpfattach2(ifp, dlt, hdrlen, driverp)
1437 struct ifnet *ifp;
1438 u_int dlt, hdrlen;
1439 struct bpf_if **driverp;
1440 {
1441 struct bpf_if *bp;
1442 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
1443 if (bp == NULL)
1444 panic("bpfattach");
1445
1446 LIST_INIT(&bp->bif_dlist);
1447 bp->bif_driverp = driverp;
1448 bp->bif_ifp = ifp;
1449 bp->bif_dlt = dlt;
1450 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF);
1451
1452 mtx_lock(&bpf_mtx);
1453 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
1454 mtx_unlock(&bpf_mtx);
1455
1456 *bp->bif_driverp = NULL;
1457
1458 /*
1459 * Compute the length of the bpf header. This is not necessarily
1460 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1461 * that the network layer header begins on a longword boundary (for
1462 * performance reasons and to alleviate alignment restrictions).
1463 */
1464 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1465
1466 if (bootverbose)
1467 if_printf(ifp, "bpf attached\n");
1468 }
1469
1470 /*
1471 * Detach bpf from an interface. This involves detaching each descriptor
1472 * associated with the interface, and leaving bd_bif NULL. Notify each
1473 * descriptor as it's detached so that any sleepers wake up and get
1474 * ENXIO.
1475 */
1476 void
1477 bpfdetach(ifp)
1478 struct ifnet *ifp;
1479 {
1480 struct bpf_if *bp;
1481 struct bpf_d *d;
1482
1483 /* Locate BPF interface information */
1484 mtx_lock(&bpf_mtx);
1485 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
1486 if (ifp == bp->bif_ifp)
1487 break;
1488 }
1489
1490 /* Interface wasn't attached */
1491 if ((bp == NULL) || (bp->bif_ifp == NULL)) {
1492 mtx_unlock(&bpf_mtx);
1493 printf("bpfdetach: %s was not attached\n", ifp->if_xname);
1494 return;
1495 }
1496
1497 LIST_REMOVE(bp, bif_next);
1498 mtx_unlock(&bpf_mtx);
1499
1500 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
1501 bpf_detachd(d);
1502 BPFD_LOCK(d);
1503 bpf_wakeup(d);
1504 BPFD_UNLOCK(d);
1505 }
1506
1507 mtx_destroy(&bp->bif_mtx);
1508 free(bp, M_BPF);
1509 }
1510
1511 /*
1512 * Get a list of available data link type of the interface.
1513 */
1514 static int
1515 bpf_getdltlist(d, bfl)
1516 struct bpf_d *d;
1517 struct bpf_dltlist *bfl;
1518 {
1519 int n, error;
1520 struct ifnet *ifp;
1521 struct bpf_if *bp;
1522
1523 ifp = d->bd_bif->bif_ifp;
1524 n = 0;
1525 error = 0;
1526 mtx_lock(&bpf_mtx);
1527 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
1528 if (bp->bif_ifp != ifp)
1529 continue;
1530 if (bfl->bfl_list != NULL) {
1531 if (n >= bfl->bfl_len) {
1532 mtx_unlock(&bpf_mtx);
1533 return (ENOMEM);
1534 }
1535 error = copyout(&bp->bif_dlt,
1536 bfl->bfl_list + n, sizeof(u_int));
1537 }
1538 n++;
1539 }
1540 mtx_unlock(&bpf_mtx);
1541 bfl->bfl_len = n;
1542 return (error);
1543 }
1544
1545 /*
1546 * Set the data link type of a BPF instance.
1547 */
1548 static int
1549 bpf_setdlt(d, dlt)
1550 struct bpf_d *d;
1551 u_int dlt;
1552 {
1553 int error, opromisc;
1554 struct ifnet *ifp;
1555 struct bpf_if *bp;
1556
1557 if (d->bd_bif->bif_dlt == dlt)
1558 return (0);
1559 ifp = d->bd_bif->bif_ifp;
1560 mtx_lock(&bpf_mtx);
1561 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
1562 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1563 break;
1564 }
1565 mtx_unlock(&bpf_mtx);
1566 if (bp != NULL) {
1567 opromisc = d->bd_promisc;
1568 bpf_detachd(d);
1569 bpf_attachd(d, bp);
1570 BPFD_LOCK(d);
1571 reset_d(d);
1572 BPFD_UNLOCK(d);
1573 if (opromisc) {
1574 error = ifpromisc(bp->bif_ifp, 1);
1575 if (error)
1576 if_printf(bp->bif_ifp,
1577 "bpf_setdlt: ifpromisc failed (%d)\n",
1578 error);
1579 else
1580 d->bd_promisc = 1;
1581 }
1582 }
1583 return (bp == NULL ? EINVAL : 0);
1584 }
1585
1586 static void bpf_drvinit(void *unused);
1587
1588 static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev);
1589
1590 static void
1591 bpf_clone(arg, name, namelen, dev)
1592 void *arg;
1593 char *name;
1594 int namelen;
1595 struct cdev **dev;
1596 {
1597 int u;
1598
1599 if (*dev != NULL)
1600 return;
1601 if (dev_stdclone(name, NULL, "bpf", &u) != 1)
1602 return;
1603 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
1604 "bpf%d", u);
1605 (*dev)->si_flags |= SI_CHEAPCLONE;
1606 return;
1607 }
1608
1609 static void
1610 bpf_drvinit(unused)
1611 void *unused;
1612 {
1613
1614 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
1615 LIST_INIT(&bpf_iflist);
1616 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000);
1617 }
1618
1619 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL)
1620
1621 #else /* !DEV_BPF && !NETGRAPH_BPF */
1622 /*
1623 * NOP stubs to allow bpf-using drivers to load and function.
1624 *
1625 * A 'better' implementation would allow the core bpf functionality
1626 * to be loaded at runtime.
1627 */
1628
1629 void
1630 bpf_tap(bp, pkt, pktlen)
1631 struct bpf_if *bp;
1632 u_char *pkt;
1633 u_int pktlen;
1634 {
1635 }
1636
1637 void
1638 bpf_mtap(bp, m)
1639 struct bpf_if *bp;
1640 struct mbuf *m;
1641 {
1642 }
1643
1644 void
1645 bpf_mtap2(bp, d, l, m)
1646 struct bpf_if *bp;
1647 void *d;
1648 u_int l;
1649 struct mbuf *m;
1650 {
1651 }
1652
1653 void
1654 bpfattach(ifp, dlt, hdrlen)
1655 struct ifnet *ifp;
1656 u_int dlt, hdrlen;
1657 {
1658 }
1659
1660 void
1661 bpfattach2(ifp, dlt, hdrlen, driverp)
1662 struct ifnet *ifp;
1663 u_int dlt, hdrlen;
1664 struct bpf_if **driverp;
1665 {
1666 }
1667
1668 void
1669 bpfdetach(ifp)
1670 struct ifnet *ifp;
1671 {
1672 }
1673
1674 u_int
1675 bpf_filter(pc, p, wirelen, buflen)
1676 const struct bpf_insn *pc;
1677 u_char *p;
1678 u_int wirelen;
1679 u_int buflen;
1680 {
1681 return -1; /* "no filter" behaviour */
1682 }
1683
1684 int
1685 bpf_validate(f, len)
1686 const struct bpf_insn *f;
1687 int len;
1688 {
1689 return 0; /* false */
1690 }
1691
1692 #endif /* !DEV_BPF && !NETGRAPH_BPF */
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