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