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
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: releng/10.2/sys/net/bpf.c 282427 2015-05-04 19:33:51Z mav $");
39
40#include "opt_bpf.h"
41#include "opt_compat.h"
42#include "opt_netgraph.h"
43
44#include <sys/types.h>
45#include <sys/param.h>
46#include <sys/lock.h>
47#include <sys/rwlock.h>
48#include <sys/systm.h>
49#include <sys/conf.h>
50#include <sys/fcntl.h>
51#include <sys/jail.h>
52#include <sys/malloc.h>
53#include <sys/mbuf.h>
54#include <sys/time.h>
55#include <sys/priv.h>
56#include <sys/proc.h>
57#include <sys/signalvar.h>
58#include <sys/filio.h>
59#include <sys/sockio.h>
60#include <sys/ttycom.h>
61#include <sys/uio.h>
62
63#include <sys/event.h>
64#include <sys/file.h>
65#include <sys/poll.h>
66#include <sys/proc.h>
67
68#include <sys/socket.h>
69
70#include <net/if.h>
71#define	BPF_INTERNAL
72#include <net/bpf.h>
73#include <net/bpf_buffer.h>
74#ifdef BPF_JITTER
75#include <net/bpf_jitter.h>
76#endif
77#include <net/bpf_zerocopy.h>
78#include <net/bpfdesc.h>
79#include <net/vnet.h>
80
81#include <netinet/in.h>
82#include <netinet/if_ether.h>
83#include <sys/kernel.h>
84#include <sys/sysctl.h>
85
86#include <net80211/ieee80211_freebsd.h>
87
88#include <security/mac/mac_framework.h>
89
90MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
91
92#if defined(DEV_BPF) || defined(NETGRAPH_BPF)
93
94#define PRINET  26			/* interruptible */
95
96#define	SIZEOF_BPF_HDR(type)	\
97    (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen))
98
99#ifdef COMPAT_FREEBSD32
100#include <sys/mount.h>
101#include <compat/freebsd32/freebsd32.h>
102#define BPF_ALIGNMENT32 sizeof(int32_t)
103#define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
104
105#ifndef BURN_BRIDGES
106/*
107 * 32-bit version of structure prepended to each packet.  We use this header
108 * instead of the standard one for 32-bit streams.  We mark the a stream as
109 * 32-bit the first time we see a 32-bit compat ioctl request.
110 */
111struct bpf_hdr32 {
112	struct timeval32 bh_tstamp;	/* time stamp */
113	uint32_t	bh_caplen;	/* length of captured portion */
114	uint32_t	bh_datalen;	/* original length of packet */
115	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
116					   plus alignment padding) */
117};
118#endif
119
120struct bpf_program32 {
121	u_int bf_len;
122	uint32_t bf_insns;
123};
124
125struct bpf_dltlist32 {
126	u_int	bfl_len;
127	u_int	bfl_list;
128};
129
130#define	BIOCSETF32	_IOW('B', 103, struct bpf_program32)
131#define	BIOCSRTIMEOUT32	_IOW('B', 109, struct timeval32)
132#define	BIOCGRTIMEOUT32	_IOR('B', 110, struct timeval32)
133#define	BIOCGDLTLIST32	_IOWR('B', 121, struct bpf_dltlist32)
134#define	BIOCSETWF32	_IOW('B', 123, struct bpf_program32)
135#define	BIOCSETFNR32	_IOW('B', 130, struct bpf_program32)
136#endif
137
138/*
139 * bpf_iflist is a list of BPF interface structures, each corresponding to a
140 * specific DLT.  The same network interface might have several BPF interface
141 * structures registered by different layers in the stack (i.e., 802.11
142 * frames, ethernet frames, etc).
143 */
144static LIST_HEAD(, bpf_if)	bpf_iflist, bpf_freelist;
145static struct mtx	bpf_mtx;		/* bpf global lock */
146static int		bpf_bpfd_cnt;
147
148static void	bpf_attachd(struct bpf_d *, struct bpf_if *);
149static void	bpf_detachd(struct bpf_d *);
150static void	bpf_detachd_locked(struct bpf_d *);
151static void	bpf_freed(struct bpf_d *);
152static int	bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
153		    struct sockaddr *, int *, struct bpf_insn *);
154static int	bpf_setif(struct bpf_d *, struct ifreq *);
155static void	bpf_timed_out(void *);
156static __inline void
157		bpf_wakeup(struct bpf_d *);
158static void	catchpacket(struct bpf_d *, u_char *, u_int, u_int,
159		    void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
160		    struct bintime *);
161static void	reset_d(struct bpf_d *);
162static int	bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
163static int	bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
164static int	bpf_setdlt(struct bpf_d *, u_int);
165static void	filt_bpfdetach(struct knote *);
166static int	filt_bpfread(struct knote *, long);
167static void	bpf_drvinit(void *);
168static int	bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
169
170SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
171int bpf_maxinsns = BPF_MAXINSNS;
172SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
173    &bpf_maxinsns, 0, "Maximum bpf program instructions");
174static int bpf_zerocopy_enable = 0;
175SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
176    &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
177static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
178    bpf_stats_sysctl, "bpf statistics portal");
179
180static VNET_DEFINE(int, bpf_optimize_writers) = 0;
181#define	V_bpf_optimize_writers VNET(bpf_optimize_writers)
182SYSCTL_VNET_INT(_net_bpf, OID_AUTO, optimize_writers,
183    CTLFLAG_RW, &VNET_NAME(bpf_optimize_writers), 0,
184    "Do not send packets until BPF program is set");
185
186static	d_open_t	bpfopen;
187static	d_read_t	bpfread;
188static	d_write_t	bpfwrite;
189static	d_ioctl_t	bpfioctl;
190static	d_poll_t	bpfpoll;
191static	d_kqfilter_t	bpfkqfilter;
192
193static struct cdevsw bpf_cdevsw = {
194	.d_version =	D_VERSION,
195	.d_open =	bpfopen,
196	.d_read =	bpfread,
197	.d_write =	bpfwrite,
198	.d_ioctl =	bpfioctl,
199	.d_poll =	bpfpoll,
200	.d_name =	"bpf",
201	.d_kqfilter =	bpfkqfilter,
202};
203
204static struct filterops bpfread_filtops = {
205	.f_isfd = 1,
206	.f_detach = filt_bpfdetach,
207	.f_event = filt_bpfread,
208};
209
210eventhandler_tag	bpf_ifdetach_cookie = NULL;
211
212/*
213 * LOCKING MODEL USED BY BPF:
214 * Locks:
215 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal,
216 * some global counters and every bpf_if reference.
217 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters.
218 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields
219 *   used by bpf_mtap code.
220 *
221 * Lock order:
222 *
223 * Global lock, interface lock, descriptor lock
224 *
225 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2]
226 * working model. In many places (like bpf_detachd) we start with BPF descriptor
227 * (and we need to at least rlock it to get reliable interface pointer). This
228 * gives us potential LOR. As a result, we use global lock to protect from bpf_if
229 * change in every such place.
230 *
231 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and
232 * 3) descriptor main wlock.
233 * Reading bd_bif can be protected by any of these locks, typically global lock.
234 *
235 * Changing read/write BPF filter is protected by the same three locks,
236 * the same applies for reading.
237 *
238 * Sleeping in global lock is not allowed due to bpfdetach() using it.
239 */
240
241/*
242 * Wrapper functions for various buffering methods.  If the set of buffer
243 * modes expands, we will probably want to introduce a switch data structure
244 * similar to protosw, et.
245 */
246static void
247bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
248    u_int len)
249{
250
251	BPFD_LOCK_ASSERT(d);
252
253	switch (d->bd_bufmode) {
254	case BPF_BUFMODE_BUFFER:
255		return (bpf_buffer_append_bytes(d, buf, offset, src, len));
256
257	case BPF_BUFMODE_ZBUF:
258		d->bd_zcopy++;
259		return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
260
261	default:
262		panic("bpf_buf_append_bytes");
263	}
264}
265
266static void
267bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
268    u_int len)
269{
270
271	BPFD_LOCK_ASSERT(d);
272
273	switch (d->bd_bufmode) {
274	case BPF_BUFMODE_BUFFER:
275		return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
276
277	case BPF_BUFMODE_ZBUF:
278		d->bd_zcopy++;
279		return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
280
281	default:
282		panic("bpf_buf_append_mbuf");
283	}
284}
285
286/*
287 * This function gets called when the free buffer is re-assigned.
288 */
289static void
290bpf_buf_reclaimed(struct bpf_d *d)
291{
292
293	BPFD_LOCK_ASSERT(d);
294
295	switch (d->bd_bufmode) {
296	case BPF_BUFMODE_BUFFER:
297		return;
298
299	case BPF_BUFMODE_ZBUF:
300		bpf_zerocopy_buf_reclaimed(d);
301		return;
302
303	default:
304		panic("bpf_buf_reclaimed");
305	}
306}
307
308/*
309 * If the buffer mechanism has a way to decide that a held buffer can be made
310 * free, then it is exposed via the bpf_canfreebuf() interface.  (1) is
311 * returned if the buffer can be discarded, (0) is returned if it cannot.
312 */
313static int
314bpf_canfreebuf(struct bpf_d *d)
315{
316
317	BPFD_LOCK_ASSERT(d);
318
319	switch (d->bd_bufmode) {
320	case BPF_BUFMODE_ZBUF:
321		return (bpf_zerocopy_canfreebuf(d));
322	}
323	return (0);
324}
325
326/*
327 * Allow the buffer model to indicate that the current store buffer is
328 * immutable, regardless of the appearance of space.  Return (1) if the
329 * buffer is writable, and (0) if not.
330 */
331static int
332bpf_canwritebuf(struct bpf_d *d)
333{
334	BPFD_LOCK_ASSERT(d);
335
336	switch (d->bd_bufmode) {
337	case BPF_BUFMODE_ZBUF:
338		return (bpf_zerocopy_canwritebuf(d));
339	}
340	return (1);
341}
342
343/*
344 * Notify buffer model that an attempt to write to the store buffer has
345 * resulted in a dropped packet, in which case the buffer may be considered
346 * full.
347 */
348static void
349bpf_buffull(struct bpf_d *d)
350{
351
352	BPFD_LOCK_ASSERT(d);
353
354	switch (d->bd_bufmode) {
355	case BPF_BUFMODE_ZBUF:
356		bpf_zerocopy_buffull(d);
357		break;
358	}
359}
360
361/*
362 * Notify the buffer model that a buffer has moved into the hold position.
363 */
364void
365bpf_bufheld(struct bpf_d *d)
366{
367
368	BPFD_LOCK_ASSERT(d);
369
370	switch (d->bd_bufmode) {
371	case BPF_BUFMODE_ZBUF:
372		bpf_zerocopy_bufheld(d);
373		break;
374	}
375}
376
377static void
378bpf_free(struct bpf_d *d)
379{
380
381	switch (d->bd_bufmode) {
382	case BPF_BUFMODE_BUFFER:
383		return (bpf_buffer_free(d));
384
385	case BPF_BUFMODE_ZBUF:
386		return (bpf_zerocopy_free(d));
387
388	default:
389		panic("bpf_buf_free");
390	}
391}
392
393static int
394bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
395{
396
397	if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
398		return (EOPNOTSUPP);
399	return (bpf_buffer_uiomove(d, buf, len, uio));
400}
401
402static int
403bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
404{
405
406	if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
407		return (EOPNOTSUPP);
408	return (bpf_buffer_ioctl_sblen(d, i));
409}
410
411static int
412bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
413{
414
415	if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
416		return (EOPNOTSUPP);
417	return (bpf_zerocopy_ioctl_getzmax(td, d, i));
418}
419
420static int
421bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
422{
423
424	if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
425		return (EOPNOTSUPP);
426	return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
427}
428
429static int
430bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
431{
432
433	if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
434		return (EOPNOTSUPP);
435	return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
436}
437
438/*
439 * General BPF functions.
440 */
441static int
442bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
443    struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter)
444{
445	const struct ieee80211_bpf_params *p;
446	struct ether_header *eh;
447	struct mbuf *m;
448	int error;
449	int len;
450	int hlen;
451	int slen;
452
453	/*
454	 * Build a sockaddr based on the data link layer type.
455	 * We do this at this level because the ethernet header
456	 * is copied directly into the data field of the sockaddr.
457	 * In the case of SLIP, there is no header and the packet
458	 * is forwarded as is.
459	 * Also, we are careful to leave room at the front of the mbuf
460	 * for the link level header.
461	 */
462	switch (linktype) {
463
464	case DLT_SLIP:
465		sockp->sa_family = AF_INET;
466		hlen = 0;
467		break;
468
469	case DLT_EN10MB:
470		sockp->sa_family = AF_UNSPEC;
471		/* XXX Would MAXLINKHDR be better? */
472		hlen = ETHER_HDR_LEN;
473		break;
474
475	case DLT_FDDI:
476		sockp->sa_family = AF_IMPLINK;
477		hlen = 0;
478		break;
479
480	case DLT_RAW:
481		sockp->sa_family = AF_UNSPEC;
482		hlen = 0;
483		break;
484
485	case DLT_NULL:
486		/*
487		 * null interface types require a 4 byte pseudo header which
488		 * corresponds to the address family of the packet.
489		 */
490		sockp->sa_family = AF_UNSPEC;
491		hlen = 4;
492		break;
493
494	case DLT_ATM_RFC1483:
495		/*
496		 * en atm driver requires 4-byte atm pseudo header.
497		 * though it isn't standard, vpi:vci needs to be
498		 * specified anyway.
499		 */
500		sockp->sa_family = AF_UNSPEC;
501		hlen = 12;	/* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
502		break;
503
504	case DLT_PPP:
505		sockp->sa_family = AF_UNSPEC;
506		hlen = 4;	/* This should match PPP_HDRLEN */
507		break;
508
509	case DLT_IEEE802_11:		/* IEEE 802.11 wireless */
510		sockp->sa_family = AF_IEEE80211;
511		hlen = 0;
512		break;
513
514	case DLT_IEEE802_11_RADIO:	/* IEEE 802.11 wireless w/ phy params */
515		sockp->sa_family = AF_IEEE80211;
516		sockp->sa_len = 12;	/* XXX != 0 */
517		hlen = sizeof(struct ieee80211_bpf_params);
518		break;
519
520	default:
521		return (EIO);
522	}
523
524	len = uio->uio_resid;
525	if (len < hlen || len - hlen > ifp->if_mtu)
526		return (EMSGSIZE);
527
528	m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR);
529	if (m == NULL)
530		return (EIO);
531	m->m_pkthdr.len = m->m_len = len;
532	*mp = m;
533
534	error = uiomove(mtod(m, u_char *), len, uio);
535	if (error)
536		goto bad;
537
538	slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
539	if (slen == 0) {
540		error = EPERM;
541		goto bad;
542	}
543
544	/* Check for multicast destination */
545	switch (linktype) {
546	case DLT_EN10MB:
547		eh = mtod(m, struct ether_header *);
548		if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
549			if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
550			    ETHER_ADDR_LEN) == 0)
551				m->m_flags |= M_BCAST;
552			else
553				m->m_flags |= M_MCAST;
554		}
555		break;
556	}
557
558	/*
559	 * Make room for link header, and copy it to sockaddr
560	 */
561	if (hlen != 0) {
562		if (sockp->sa_family == AF_IEEE80211) {
563			/*
564			 * Collect true length from the parameter header
565			 * NB: sockp is known to be zero'd so if we do a
566			 *     short copy unspecified parameters will be
567			 *     zero.
568			 * NB: packet may not be aligned after stripping
569			 *     bpf params
570			 * XXX check ibp_vers
571			 */
572			p = mtod(m, const struct ieee80211_bpf_params *);
573			hlen = p->ibp_len;
574			if (hlen > sizeof(sockp->sa_data)) {
575				error = EINVAL;
576				goto bad;
577			}
578		}
579		bcopy(m->m_data, sockp->sa_data, hlen);
580	}
581	*hdrlen = hlen;
582
583	return (0);
584bad:
585	m_freem(m);
586	return (error);
587}
588
589/*
590 * Attach file to the bpf interface, i.e. make d listen on bp.
591 */
592static void
593bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
594{
595	int op_w;
596
597	BPF_LOCK_ASSERT();
598
599	/*
600	 * Save sysctl value to protect from sysctl change
601	 * between reads
602	 */
603	op_w = V_bpf_optimize_writers || d->bd_writer;
604
605	if (d->bd_bif != NULL)
606		bpf_detachd_locked(d);
607	/*
608	 * Point d at bp, and add d to the interface's list.
609	 * Since there are many applicaiotns using BPF for
610	 * sending raw packets only (dhcpd, cdpd are good examples)
611	 * we can delay adding d to the list of active listeners until
612	 * some filter is configured.
613	 */
614
615	BPFIF_WLOCK(bp);
616	BPFD_LOCK(d);
617
618	d->bd_bif = bp;
619
620	if (op_w != 0) {
621		/* Add to writers-only list */
622		LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next);
623		/*
624		 * We decrement bd_writer on every filter set operation.
625		 * First BIOCSETF is done by pcap_open_live() to set up
626		 * snap length. After that appliation usually sets its own filter
627		 */
628		d->bd_writer = 2;
629	} else
630		LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
631
632	BPFD_UNLOCK(d);
633	BPFIF_WUNLOCK(bp);
634
635	bpf_bpfd_cnt++;
636
637	CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list",
638	    __func__, d->bd_pid, d->bd_writer ? "writer" : "active");
639
640	if (op_w == 0)
641		EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
642}
643
644/*
645 * Add d to the list of active bp filters.
646 * Reuqires bpf_attachd() to be called before
647 */
648static void
649bpf_upgraded(struct bpf_d *d)
650{
651	struct bpf_if *bp;
652
653	BPF_LOCK_ASSERT();
654
655	bp = d->bd_bif;
656
657	/*
658	 * Filter can be set several times without specifying interface.
659	 * Mark d as reader and exit.
660	 */
661	if (bp == NULL) {
662		BPFD_LOCK(d);
663		d->bd_writer = 0;
664		BPFD_UNLOCK(d);
665		return;
666	}
667
668	BPFIF_WLOCK(bp);
669	BPFD_LOCK(d);
670
671	/* Remove from writers-only list */
672	LIST_REMOVE(d, bd_next);
673	LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
674	/* Mark d as reader */
675	d->bd_writer = 0;
676
677	BPFD_UNLOCK(d);
678	BPFIF_WUNLOCK(bp);
679
680	CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid);
681
682	EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
683}
684
685/*
686 * Detach a file from its interface.
687 */
688static void
689bpf_detachd(struct bpf_d *d)
690{
691	BPF_LOCK();
692	bpf_detachd_locked(d);
693	BPF_UNLOCK();
694}
695
696static void
697bpf_detachd_locked(struct bpf_d *d)
698{
699	int error;
700	struct bpf_if *bp;
701	struct ifnet *ifp;
702
703	CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid);
704
705	BPF_LOCK_ASSERT();
706
707	/* Check if descriptor is attached */
708	if ((bp = d->bd_bif) == NULL)
709		return;
710
711	BPFIF_WLOCK(bp);
712	BPFD_LOCK(d);
713
714	/* Save bd_writer value */
715	error = d->bd_writer;
716
717	/*
718	 * Remove d from the interface's descriptor list.
719	 */
720	LIST_REMOVE(d, bd_next);
721
722	ifp = bp->bif_ifp;
723	d->bd_bif = NULL;
724	BPFD_UNLOCK(d);
725	BPFIF_WUNLOCK(bp);
726
727	bpf_bpfd_cnt--;
728
729	/* Call event handler iff d is attached */
730	if (error == 0)
731		EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
732
733	/*
734	 * Check if this descriptor had requested promiscuous mode.
735	 * If so, turn it off.
736	 */
737	if (d->bd_promisc) {
738		d->bd_promisc = 0;
739		CURVNET_SET(ifp->if_vnet);
740		error = ifpromisc(ifp, 0);
741		CURVNET_RESTORE();
742		if (error != 0 && error != ENXIO) {
743			/*
744			 * ENXIO can happen if a pccard is unplugged
745			 * Something is really wrong if we were able to put
746			 * the driver into promiscuous mode, but can't
747			 * take it out.
748			 */
749			if_printf(bp->bif_ifp,
750				"bpf_detach: ifpromisc failed (%d)\n", error);
751		}
752	}
753}
754
755/*
756 * Close the descriptor by detaching it from its interface,
757 * deallocating its buffers, and marking it free.
758 */
759static void
760bpf_dtor(void *data)
761{
762	struct bpf_d *d = data;
763
764	BPFD_LOCK(d);
765	if (d->bd_state == BPF_WAITING)
766		callout_stop(&d->bd_callout);
767	d->bd_state = BPF_IDLE;
768	BPFD_UNLOCK(d);
769	funsetown(&d->bd_sigio);
770	bpf_detachd(d);
771#ifdef MAC
772	mac_bpfdesc_destroy(d);
773#endif /* MAC */
774	seldrain(&d->bd_sel);
775	knlist_destroy(&d->bd_sel.si_note);
776	callout_drain(&d->bd_callout);
777	bpf_freed(d);
778	free(d, M_BPF);
779}
780
781/*
782 * Open ethernet device.  Returns ENXIO for illegal minor device number,
783 * EBUSY if file is open by another process.
784 */
785/* ARGSUSED */
786static	int
787bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
788{
789	struct bpf_d *d;
790	int error, size;
791
792	d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
793	error = devfs_set_cdevpriv(d, bpf_dtor);
794	if (error != 0) {
795		free(d, M_BPF);
796		return (error);
797	}
798
799	/*
800	 * For historical reasons, perform a one-time initialization call to
801	 * the buffer routines, even though we're not yet committed to a
802	 * particular buffer method.
803	 */
804	bpf_buffer_init(d);
805	if ((flags & FREAD) == 0)
806		d->bd_writer = 2;
807	d->bd_hbuf_in_use = 0;
808	d->bd_bufmode = BPF_BUFMODE_BUFFER;
809	d->bd_sig = SIGIO;
810	d->bd_direction = BPF_D_INOUT;
811	BPF_PID_REFRESH(d, td);
812#ifdef MAC
813	mac_bpfdesc_init(d);
814	mac_bpfdesc_create(td->td_ucred, d);
815#endif
816	mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF);
817	callout_init_mtx(&d->bd_callout, &d->bd_lock, 0);
818	knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock);
819
820	/* Allocate default buffers */
821	size = d->bd_bufsize;
822	bpf_buffer_ioctl_sblen(d, &size);
823
824	return (0);
825}
826
827/*
828 *  bpfread - read next chunk of packets from buffers
829 */
830static	int
831bpfread(struct cdev *dev, struct uio *uio, int ioflag)
832{
833	struct bpf_d *d;
834	int error;
835	int non_block;
836	int timed_out;
837
838	error = devfs_get_cdevpriv((void **)&d);
839	if (error != 0)
840		return (error);
841
842	/*
843	 * Restrict application to use a buffer the same size as
844	 * as kernel buffers.
845	 */
846	if (uio->uio_resid != d->bd_bufsize)
847		return (EINVAL);
848
849	non_block = ((ioflag & O_NONBLOCK) != 0);
850
851	BPFD_LOCK(d);
852	BPF_PID_REFRESH_CUR(d);
853	if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
854		BPFD_UNLOCK(d);
855		return (EOPNOTSUPP);
856	}
857	if (d->bd_state == BPF_WAITING)
858		callout_stop(&d->bd_callout);
859	timed_out = (d->bd_state == BPF_TIMED_OUT);
860	d->bd_state = BPF_IDLE;
861	while (d->bd_hbuf_in_use) {
862		error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
863		    PRINET|PCATCH, "bd_hbuf", 0);
864		if (error != 0) {
865			BPFD_UNLOCK(d);
866			return (error);
867		}
868	}
869	/*
870	 * If the hold buffer is empty, then do a timed sleep, which
871	 * ends when the timeout expires or when enough packets
872	 * have arrived to fill the store buffer.
873	 */
874	while (d->bd_hbuf == NULL) {
875		if (d->bd_slen != 0) {
876			/*
877			 * A packet(s) either arrived since the previous
878			 * read or arrived while we were asleep.
879			 */
880			if (d->bd_immediate || non_block || timed_out) {
881				/*
882				 * Rotate the buffers and return what's here
883				 * if we are in immediate mode, non-blocking
884				 * flag is set, or this descriptor timed out.
885				 */
886				ROTATE_BUFFERS(d);
887				break;
888			}
889		}
890
891		/*
892		 * No data is available, check to see if the bpf device
893		 * is still pointed at a real interface.  If not, return
894		 * ENXIO so that the userland process knows to rebind
895		 * it before using it again.
896		 */
897		if (d->bd_bif == NULL) {
898			BPFD_UNLOCK(d);
899			return (ENXIO);
900		}
901
902		if (non_block) {
903			BPFD_UNLOCK(d);
904			return (EWOULDBLOCK);
905		}
906		error = msleep(d, &d->bd_lock, PRINET|PCATCH,
907		     "bpf", d->bd_rtout);
908		if (error == EINTR || error == ERESTART) {
909			BPFD_UNLOCK(d);
910			return (error);
911		}
912		if (error == EWOULDBLOCK) {
913			/*
914			 * On a timeout, return what's in the buffer,
915			 * which may be nothing.  If there is something
916			 * in the store buffer, we can rotate the buffers.
917			 */
918			if (d->bd_hbuf)
919				/*
920				 * We filled up the buffer in between
921				 * getting the timeout and arriving
922				 * here, so we don't need to rotate.
923				 */
924				break;
925
926			if (d->bd_slen == 0) {
927				BPFD_UNLOCK(d);
928				return (0);
929			}
930			ROTATE_BUFFERS(d);
931			break;
932		}
933	}
934	/*
935	 * At this point, we know we have something in the hold slot.
936	 */
937	d->bd_hbuf_in_use = 1;
938	BPFD_UNLOCK(d);
939
940	/*
941	 * Move data from hold buffer into user space.
942	 * We know the entire buffer is transferred since
943	 * we checked above that the read buffer is bpf_bufsize bytes.
944  	 *
945	 * We do not have to worry about simultaneous reads because
946	 * we waited for sole access to the hold buffer above.
947	 */
948	error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
949
950	BPFD_LOCK(d);
951	KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf"));
952	d->bd_fbuf = d->bd_hbuf;
953	d->bd_hbuf = NULL;
954	d->bd_hlen = 0;
955	bpf_buf_reclaimed(d);
956	d->bd_hbuf_in_use = 0;
957	wakeup(&d->bd_hbuf_in_use);
958	BPFD_UNLOCK(d);
959
960	return (error);
961}
962
963/*
964 * If there are processes sleeping on this descriptor, wake them up.
965 */
966static __inline void
967bpf_wakeup(struct bpf_d *d)
968{
969
970	BPFD_LOCK_ASSERT(d);
971	if (d->bd_state == BPF_WAITING) {
972		callout_stop(&d->bd_callout);
973		d->bd_state = BPF_IDLE;
974	}
975	wakeup(d);
976	if (d->bd_async && d->bd_sig && d->bd_sigio)
977		pgsigio(&d->bd_sigio, d->bd_sig, 0);
978
979	selwakeuppri(&d->bd_sel, PRINET);
980	KNOTE_LOCKED(&d->bd_sel.si_note, 0);
981}
982
983static void
984bpf_timed_out(void *arg)
985{
986	struct bpf_d *d = (struct bpf_d *)arg;
987
988	BPFD_LOCK_ASSERT(d);
989
990	if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
991		return;
992	if (d->bd_state == BPF_WAITING) {
993		d->bd_state = BPF_TIMED_OUT;
994		if (d->bd_slen != 0)
995			bpf_wakeup(d);
996	}
997}
998
999static int
1000bpf_ready(struct bpf_d *d)
1001{
1002
1003	BPFD_LOCK_ASSERT(d);
1004
1005	if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
1006		return (1);
1007	if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1008	    d->bd_slen != 0)
1009		return (1);
1010	return (0);
1011}
1012
1013static int
1014bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
1015{
1016	struct bpf_d *d;
1017	struct ifnet *ifp;
1018	struct mbuf *m, *mc;
1019	struct sockaddr dst;
1020	int error, hlen;
1021
1022	error = devfs_get_cdevpriv((void **)&d);
1023	if (error != 0)
1024		return (error);
1025
1026	BPF_PID_REFRESH_CUR(d);
1027	d->bd_wcount++;
1028	/* XXX: locking required */
1029	if (d->bd_bif == NULL) {
1030		d->bd_wdcount++;
1031		return (ENXIO);
1032	}
1033
1034	ifp = d->bd_bif->bif_ifp;
1035
1036	if ((ifp->if_flags & IFF_UP) == 0) {
1037		d->bd_wdcount++;
1038		return (ENETDOWN);
1039	}
1040
1041	if (uio->uio_resid == 0) {
1042		d->bd_wdcount++;
1043		return (0);
1044	}
1045
1046	bzero(&dst, sizeof(dst));
1047	m = NULL;
1048	hlen = 0;
1049	/* XXX: bpf_movein() can sleep */
1050	error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
1051	    &m, &dst, &hlen, d->bd_wfilter);
1052	if (error) {
1053		d->bd_wdcount++;
1054		return (error);
1055	}
1056	d->bd_wfcount++;
1057	if (d->bd_hdrcmplt)
1058		dst.sa_family = pseudo_AF_HDRCMPLT;
1059
1060	if (d->bd_feedback) {
1061		mc = m_dup(m, M_NOWAIT);
1062		if (mc != NULL)
1063			mc->m_pkthdr.rcvif = ifp;
1064		/* Set M_PROMISC for outgoing packets to be discarded. */
1065		if (d->bd_direction == BPF_D_INOUT)
1066			m->m_flags |= M_PROMISC;
1067	} else
1068		mc = NULL;
1069
1070	m->m_pkthdr.len -= hlen;
1071	m->m_len -= hlen;
1072	m->m_data += hlen;	/* XXX */
1073
1074	CURVNET_SET(ifp->if_vnet);
1075#ifdef MAC
1076	BPFD_LOCK(d);
1077	mac_bpfdesc_create_mbuf(d, m);
1078	if (mc != NULL)
1079		mac_bpfdesc_create_mbuf(d, mc);
1080	BPFD_UNLOCK(d);
1081#endif
1082
1083	error = (*ifp->if_output)(ifp, m, &dst, NULL);
1084	if (error)
1085		d->bd_wdcount++;
1086
1087	if (mc != NULL) {
1088		if (error == 0)
1089			(*ifp->if_input)(ifp, mc);
1090		else
1091			m_freem(mc);
1092	}
1093	CURVNET_RESTORE();
1094
1095	return (error);
1096}
1097
1098/*
1099 * Reset a descriptor by flushing its packet buffer and clearing the receive
1100 * and drop counts.  This is doable for kernel-only buffers, but with
1101 * zero-copy buffers, we can't write to (or rotate) buffers that are
1102 * currently owned by userspace.  It would be nice if we could encapsulate
1103 * this logic in the buffer code rather than here.
1104 */
1105static void
1106reset_d(struct bpf_d *d)
1107{
1108
1109	BPFD_LOCK_ASSERT(d);
1110
1111	while (d->bd_hbuf_in_use)
1112		mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET,
1113		    "bd_hbuf", 0);
1114	if ((d->bd_hbuf != NULL) &&
1115	    (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
1116		/* Free the hold buffer. */
1117		d->bd_fbuf = d->bd_hbuf;
1118		d->bd_hbuf = NULL;
1119		d->bd_hlen = 0;
1120		bpf_buf_reclaimed(d);
1121	}
1122	if (bpf_canwritebuf(d))
1123		d->bd_slen = 0;
1124	d->bd_rcount = 0;
1125	d->bd_dcount = 0;
1126	d->bd_fcount = 0;
1127	d->bd_wcount = 0;
1128	d->bd_wfcount = 0;
1129	d->bd_wdcount = 0;
1130	d->bd_zcopy = 0;
1131}
1132
1133/*
1134 *  FIONREAD		Check for read packet available.
1135 *  SIOCGIFADDR		Get interface address - convenient hook to driver.
1136 *  BIOCGBLEN		Get buffer len [for read()].
1137 *  BIOCSETF		Set read filter.
1138 *  BIOCSETFNR		Set read filter without resetting descriptor.
1139 *  BIOCSETWF		Set write filter.
1140 *  BIOCFLUSH		Flush read packet buffer.
1141 *  BIOCPROMISC		Put interface into promiscuous mode.
1142 *  BIOCGDLT		Get link layer type.
1143 *  BIOCGETIF		Get interface name.
1144 *  BIOCSETIF		Set interface.
1145 *  BIOCSRTIMEOUT	Set read timeout.
1146 *  BIOCGRTIMEOUT	Get read timeout.
1147 *  BIOCGSTATS		Get packet stats.
1148 *  BIOCIMMEDIATE	Set immediate mode.
1149 *  BIOCVERSION		Get filter language version.
1150 *  BIOCGHDRCMPLT	Get "header already complete" flag
1151 *  BIOCSHDRCMPLT	Set "header already complete" flag
1152 *  BIOCGDIRECTION	Get packet direction flag
1153 *  BIOCSDIRECTION	Set packet direction flag
1154 *  BIOCGTSTAMP		Get time stamp format and resolution.
1155 *  BIOCSTSTAMP		Set time stamp format and resolution.
1156 *  BIOCLOCK		Set "locked" flag
1157 *  BIOCFEEDBACK	Set packet feedback mode.
1158 *  BIOCSETZBUF		Set current zero-copy buffer locations.
1159 *  BIOCGETZMAX		Get maximum zero-copy buffer size.
1160 *  BIOCROTZBUF		Force rotation of zero-copy buffer
1161 *  BIOCSETBUFMODE	Set buffer mode.
1162 *  BIOCGETBUFMODE	Get current buffer mode.
1163 */
1164/* ARGSUSED */
1165static	int
1166bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1167    struct thread *td)
1168{
1169	struct bpf_d *d;
1170	int error;
1171
1172	error = devfs_get_cdevpriv((void **)&d);
1173	if (error != 0)
1174		return (error);
1175
1176	/*
1177	 * Refresh PID associated with this descriptor.
1178	 */
1179	BPFD_LOCK(d);
1180	BPF_PID_REFRESH(d, td);
1181	if (d->bd_state == BPF_WAITING)
1182		callout_stop(&d->bd_callout);
1183	d->bd_state = BPF_IDLE;
1184	BPFD_UNLOCK(d);
1185
1186	if (d->bd_locked == 1) {
1187		switch (cmd) {
1188		case BIOCGBLEN:
1189		case BIOCFLUSH:
1190		case BIOCGDLT:
1191		case BIOCGDLTLIST:
1192#ifdef COMPAT_FREEBSD32
1193		case BIOCGDLTLIST32:
1194#endif
1195		case BIOCGETIF:
1196		case BIOCGRTIMEOUT:
1197#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1198		case BIOCGRTIMEOUT32:
1199#endif
1200		case BIOCGSTATS:
1201		case BIOCVERSION:
1202		case BIOCGRSIG:
1203		case BIOCGHDRCMPLT:
1204		case BIOCSTSTAMP:
1205		case BIOCFEEDBACK:
1206		case FIONREAD:
1207		case BIOCLOCK:
1208		case BIOCSRTIMEOUT:
1209#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1210		case BIOCSRTIMEOUT32:
1211#endif
1212		case BIOCIMMEDIATE:
1213		case TIOCGPGRP:
1214		case BIOCROTZBUF:
1215			break;
1216		default:
1217			return (EPERM);
1218		}
1219	}
1220#ifdef COMPAT_FREEBSD32
1221	/*
1222	 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so
1223	 * that it will get 32-bit packet headers.
1224	 */
1225	switch (cmd) {
1226	case BIOCSETF32:
1227	case BIOCSETFNR32:
1228	case BIOCSETWF32:
1229	case BIOCGDLTLIST32:
1230	case BIOCGRTIMEOUT32:
1231	case BIOCSRTIMEOUT32:
1232		BPFD_LOCK(d);
1233		d->bd_compat32 = 1;
1234		BPFD_UNLOCK(d);
1235	}
1236#endif
1237
1238	CURVNET_SET(TD_TO_VNET(td));
1239	switch (cmd) {
1240
1241	default:
1242		error = EINVAL;
1243		break;
1244
1245	/*
1246	 * Check for read packet available.
1247	 */
1248	case FIONREAD:
1249		{
1250			int n;
1251
1252			BPFD_LOCK(d);
1253			n = d->bd_slen;
1254			while (d->bd_hbuf_in_use)
1255				mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
1256				    PRINET, "bd_hbuf", 0);
1257			if (d->bd_hbuf)
1258				n += d->bd_hlen;
1259			BPFD_UNLOCK(d);
1260
1261			*(int *)addr = n;
1262			break;
1263		}
1264
1265	case SIOCGIFADDR:
1266		{
1267			struct ifnet *ifp;
1268
1269			if (d->bd_bif == NULL)
1270				error = EINVAL;
1271			else {
1272				ifp = d->bd_bif->bif_ifp;
1273				error = (*ifp->if_ioctl)(ifp, cmd, addr);
1274			}
1275			break;
1276		}
1277
1278	/*
1279	 * Get buffer len [for read()].
1280	 */
1281	case BIOCGBLEN:
1282		BPFD_LOCK(d);
1283		*(u_int *)addr = d->bd_bufsize;
1284		BPFD_UNLOCK(d);
1285		break;
1286
1287	/*
1288	 * Set buffer length.
1289	 */
1290	case BIOCSBLEN:
1291		error = bpf_ioctl_sblen(d, (u_int *)addr);
1292		break;
1293
1294	/*
1295	 * Set link layer read filter.
1296	 */
1297	case BIOCSETF:
1298	case BIOCSETFNR:
1299	case BIOCSETWF:
1300#ifdef COMPAT_FREEBSD32
1301	case BIOCSETF32:
1302	case BIOCSETFNR32:
1303	case BIOCSETWF32:
1304#endif
1305		error = bpf_setf(d, (struct bpf_program *)addr, cmd);
1306		break;
1307
1308	/*
1309	 * Flush read packet buffer.
1310	 */
1311	case BIOCFLUSH:
1312		BPFD_LOCK(d);
1313		reset_d(d);
1314		BPFD_UNLOCK(d);
1315		break;
1316
1317	/*
1318	 * Put interface into promiscuous mode.
1319	 */
1320	case BIOCPROMISC:
1321		if (d->bd_bif == NULL) {
1322			/*
1323			 * No interface attached yet.
1324			 */
1325			error = EINVAL;
1326			break;
1327		}
1328		if (d->bd_promisc == 0) {
1329			error = ifpromisc(d->bd_bif->bif_ifp, 1);
1330			if (error == 0)
1331				d->bd_promisc = 1;
1332		}
1333		break;
1334
1335	/*
1336	 * Get current data link type.
1337	 */
1338	case BIOCGDLT:
1339		BPF_LOCK();
1340		if (d->bd_bif == NULL)
1341			error = EINVAL;
1342		else
1343			*(u_int *)addr = d->bd_bif->bif_dlt;
1344		BPF_UNLOCK();
1345		break;
1346
1347	/*
1348	 * Get a list of supported data link types.
1349	 */
1350#ifdef COMPAT_FREEBSD32
1351	case BIOCGDLTLIST32:
1352		{
1353			struct bpf_dltlist32 *list32;
1354			struct bpf_dltlist dltlist;
1355
1356			list32 = (struct bpf_dltlist32 *)addr;
1357			dltlist.bfl_len = list32->bfl_len;
1358			dltlist.bfl_list = PTRIN(list32->bfl_list);
1359			BPF_LOCK();
1360			if (d->bd_bif == NULL)
1361				error = EINVAL;
1362			else {
1363				error = bpf_getdltlist(d, &dltlist);
1364				if (error == 0)
1365					list32->bfl_len = dltlist.bfl_len;
1366			}
1367			BPF_UNLOCK();
1368			break;
1369		}
1370#endif
1371
1372	case BIOCGDLTLIST:
1373		BPF_LOCK();
1374		if (d->bd_bif == NULL)
1375			error = EINVAL;
1376		else
1377			error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
1378		BPF_UNLOCK();
1379		break;
1380
1381	/*
1382	 * Set data link type.
1383	 */
1384	case BIOCSDLT:
1385		BPF_LOCK();
1386		if (d->bd_bif == NULL)
1387			error = EINVAL;
1388		else
1389			error = bpf_setdlt(d, *(u_int *)addr);
1390		BPF_UNLOCK();
1391		break;
1392
1393	/*
1394	 * Get interface name.
1395	 */
1396	case BIOCGETIF:
1397		BPF_LOCK();
1398		if (d->bd_bif == NULL)
1399			error = EINVAL;
1400		else {
1401			struct ifnet *const ifp = d->bd_bif->bif_ifp;
1402			struct ifreq *const ifr = (struct ifreq *)addr;
1403
1404			strlcpy(ifr->ifr_name, ifp->if_xname,
1405			    sizeof(ifr->ifr_name));
1406		}
1407		BPF_UNLOCK();
1408		break;
1409
1410	/*
1411	 * Set interface.
1412	 */
1413	case BIOCSETIF:
1414		BPF_LOCK();
1415		error = bpf_setif(d, (struct ifreq *)addr);
1416		BPF_UNLOCK();
1417		break;
1418
1419	/*
1420	 * Set read timeout.
1421	 */
1422	case BIOCSRTIMEOUT:
1423#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1424	case BIOCSRTIMEOUT32:
1425#endif
1426		{
1427			struct timeval *tv = (struct timeval *)addr;
1428#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1429			struct timeval32 *tv32;
1430			struct timeval tv64;
1431
1432			if (cmd == BIOCSRTIMEOUT32) {
1433				tv32 = (struct timeval32 *)addr;
1434				tv = &tv64;
1435				tv->tv_sec = tv32->tv_sec;
1436				tv->tv_usec = tv32->tv_usec;
1437			} else
1438#endif
1439				tv = (struct timeval *)addr;
1440
1441			/*
1442			 * Subtract 1 tick from tvtohz() since this isn't
1443			 * a one-shot timer.
1444			 */
1445			if ((error = itimerfix(tv)) == 0)
1446				d->bd_rtout = tvtohz(tv) - 1;
1447			break;
1448		}
1449
1450	/*
1451	 * Get read timeout.
1452	 */
1453	case BIOCGRTIMEOUT:
1454#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1455	case BIOCGRTIMEOUT32:
1456#endif
1457		{
1458			struct timeval *tv;
1459#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1460			struct timeval32 *tv32;
1461			struct timeval tv64;
1462
1463			if (cmd == BIOCGRTIMEOUT32)
1464				tv = &tv64;
1465			else
1466#endif
1467				tv = (struct timeval *)addr;
1468
1469			tv->tv_sec = d->bd_rtout / hz;
1470			tv->tv_usec = (d->bd_rtout % hz) * tick;
1471#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1472			if (cmd == BIOCGRTIMEOUT32) {
1473				tv32 = (struct timeval32 *)addr;
1474				tv32->tv_sec = tv->tv_sec;
1475				tv32->tv_usec = tv->tv_usec;
1476			}
1477#endif
1478
1479			break;
1480		}
1481
1482	/*
1483	 * Get packet stats.
1484	 */
1485	case BIOCGSTATS:
1486		{
1487			struct bpf_stat *bs = (struct bpf_stat *)addr;
1488
1489			/* XXXCSJP overflow */
1490			bs->bs_recv = d->bd_rcount;
1491			bs->bs_drop = d->bd_dcount;
1492			break;
1493		}
1494
1495	/*
1496	 * Set immediate mode.
1497	 */
1498	case BIOCIMMEDIATE:
1499		BPFD_LOCK(d);
1500		d->bd_immediate = *(u_int *)addr;
1501		BPFD_UNLOCK(d);
1502		break;
1503
1504	case BIOCVERSION:
1505		{
1506			struct bpf_version *bv = (struct bpf_version *)addr;
1507
1508			bv->bv_major = BPF_MAJOR_VERSION;
1509			bv->bv_minor = BPF_MINOR_VERSION;
1510			break;
1511		}
1512
1513	/*
1514	 * Get "header already complete" flag
1515	 */
1516	case BIOCGHDRCMPLT:
1517		BPFD_LOCK(d);
1518		*(u_int *)addr = d->bd_hdrcmplt;
1519		BPFD_UNLOCK(d);
1520		break;
1521
1522	/*
1523	 * Set "header already complete" flag
1524	 */
1525	case BIOCSHDRCMPLT:
1526		BPFD_LOCK(d);
1527		d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
1528		BPFD_UNLOCK(d);
1529		break;
1530
1531	/*
1532	 * Get packet direction flag
1533	 */
1534	case BIOCGDIRECTION:
1535		BPFD_LOCK(d);
1536		*(u_int *)addr = d->bd_direction;
1537		BPFD_UNLOCK(d);
1538		break;
1539
1540	/*
1541	 * Set packet direction flag
1542	 */
1543	case BIOCSDIRECTION:
1544		{
1545			u_int	direction;
1546
1547			direction = *(u_int *)addr;
1548			switch (direction) {
1549			case BPF_D_IN:
1550			case BPF_D_INOUT:
1551			case BPF_D_OUT:
1552				BPFD_LOCK(d);
1553				d->bd_direction = direction;
1554				BPFD_UNLOCK(d);
1555				break;
1556			default:
1557				error = EINVAL;
1558			}
1559		}
1560		break;
1561
1562	/*
1563	 * Get packet timestamp format and resolution.
1564	 */
1565	case BIOCGTSTAMP:
1566		BPFD_LOCK(d);
1567		*(u_int *)addr = d->bd_tstamp;
1568		BPFD_UNLOCK(d);
1569		break;
1570
1571	/*
1572	 * Set packet timestamp format and resolution.
1573	 */
1574	case BIOCSTSTAMP:
1575		{
1576			u_int	func;
1577
1578			func = *(u_int *)addr;
1579			if (BPF_T_VALID(func))
1580				d->bd_tstamp = func;
1581			else
1582				error = EINVAL;
1583		}
1584		break;
1585
1586	case BIOCFEEDBACK:
1587		BPFD_LOCK(d);
1588		d->bd_feedback = *(u_int *)addr;
1589		BPFD_UNLOCK(d);
1590		break;
1591
1592	case BIOCLOCK:
1593		BPFD_LOCK(d);
1594		d->bd_locked = 1;
1595		BPFD_UNLOCK(d);
1596		break;
1597
1598	case FIONBIO:		/* Non-blocking I/O */
1599		break;
1600
1601	case FIOASYNC:		/* Send signal on receive packets */
1602		BPFD_LOCK(d);
1603		d->bd_async = *(int *)addr;
1604		BPFD_UNLOCK(d);
1605		break;
1606
1607	case FIOSETOWN:
1608		/*
1609		 * XXX: Add some sort of locking here?
1610		 * fsetown() can sleep.
1611		 */
1612		error = fsetown(*(int *)addr, &d->bd_sigio);
1613		break;
1614
1615	case FIOGETOWN:
1616		BPFD_LOCK(d);
1617		*(int *)addr = fgetown(&d->bd_sigio);
1618		BPFD_UNLOCK(d);
1619		break;
1620
1621	/* This is deprecated, FIOSETOWN should be used instead. */
1622	case TIOCSPGRP:
1623		error = fsetown(-(*(int *)addr), &d->bd_sigio);
1624		break;
1625
1626	/* This is deprecated, FIOGETOWN should be used instead. */
1627	case TIOCGPGRP:
1628		*(int *)addr = -fgetown(&d->bd_sigio);
1629		break;
1630
1631	case BIOCSRSIG:		/* Set receive signal */
1632		{
1633			u_int sig;
1634
1635			sig = *(u_int *)addr;
1636
1637			if (sig >= NSIG)
1638				error = EINVAL;
1639			else {
1640				BPFD_LOCK(d);
1641				d->bd_sig = sig;
1642				BPFD_UNLOCK(d);
1643			}
1644			break;
1645		}
1646	case BIOCGRSIG:
1647		BPFD_LOCK(d);
1648		*(u_int *)addr = d->bd_sig;
1649		BPFD_UNLOCK(d);
1650		break;
1651
1652	case BIOCGETBUFMODE:
1653		BPFD_LOCK(d);
1654		*(u_int *)addr = d->bd_bufmode;
1655		BPFD_UNLOCK(d);
1656		break;
1657
1658	case BIOCSETBUFMODE:
1659		/*
1660		 * Allow the buffering mode to be changed as long as we
1661		 * haven't yet committed to a particular mode.  Our
1662		 * definition of commitment, for now, is whether or not a
1663		 * buffer has been allocated or an interface attached, since
1664		 * that's the point where things get tricky.
1665		 */
1666		switch (*(u_int *)addr) {
1667		case BPF_BUFMODE_BUFFER:
1668			break;
1669
1670		case BPF_BUFMODE_ZBUF:
1671			if (bpf_zerocopy_enable)
1672				break;
1673			/* FALLSTHROUGH */
1674
1675		default:
1676			CURVNET_RESTORE();
1677			return (EINVAL);
1678		}
1679
1680		BPFD_LOCK(d);
1681		if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
1682		    d->bd_fbuf != NULL || d->bd_bif != NULL) {
1683			BPFD_UNLOCK(d);
1684			CURVNET_RESTORE();
1685			return (EBUSY);
1686		}
1687		d->bd_bufmode = *(u_int *)addr;
1688		BPFD_UNLOCK(d);
1689		break;
1690
1691	case BIOCGETZMAX:
1692		error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
1693		break;
1694
1695	case BIOCSETZBUF:
1696		error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
1697		break;
1698
1699	case BIOCROTZBUF:
1700		error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
1701		break;
1702	}
1703	CURVNET_RESTORE();
1704	return (error);
1705}
1706
1707/*
1708 * Set d's packet filter program to fp.  If this file already has a filter,
1709 * free it and replace it.  Returns EINVAL for bogus requests.
1710 *
1711 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls
1712 * since reading d->bd_bif can't be protected by d or interface lock due to
1713 * lock order.
1714 *
1715 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses
1716 * interface read lock to read all filers.
1717 *
1718 */
1719static int
1720bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1721{
1722#ifdef COMPAT_FREEBSD32
1723	struct bpf_program fp_swab;
1724	struct bpf_program32 *fp32;
1725#endif
1726	struct bpf_insn *fcode, *old;
1727#ifdef BPF_JITTER
1728	bpf_jit_filter *jfunc, *ofunc;
1729#endif
1730	size_t size;
1731	u_int flen;
1732	int need_upgrade;
1733
1734#ifdef COMPAT_FREEBSD32
1735	switch (cmd) {
1736	case BIOCSETF32:
1737	case BIOCSETWF32:
1738	case BIOCSETFNR32:
1739		fp32 = (struct bpf_program32 *)fp;
1740		fp_swab.bf_len = fp32->bf_len;
1741		fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
1742		fp = &fp_swab;
1743		switch (cmd) {
1744		case BIOCSETF32:
1745			cmd = BIOCSETF;
1746			break;
1747		case BIOCSETWF32:
1748			cmd = BIOCSETWF;
1749			break;
1750		}
1751		break;
1752	}
1753#endif
1754
1755	fcode = NULL;
1756#ifdef BPF_JITTER
1757	jfunc = ofunc = NULL;
1758#endif
1759	need_upgrade = 0;
1760
1761	/*
1762	 * Check new filter validness before acquiring any locks.
1763	 * Allocate memory for new filter, if needed.
1764	 */
1765	flen = fp->bf_len;
1766	if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0))
1767		return (EINVAL);
1768	size = flen * sizeof(*fp->bf_insns);
1769	if (size > 0) {
1770		/* We're setting up new filter.  Copy and check actual data. */
1771		fcode = malloc(size, M_BPF, M_WAITOK);
1772		if (copyin(fp->bf_insns, fcode, size) != 0 ||
1773		    !bpf_validate(fcode, flen)) {
1774			free(fcode, M_BPF);
1775			return (EINVAL);
1776		}
1777#ifdef BPF_JITTER
1778		/* Filter is copied inside fcode and is perfectly valid. */
1779		jfunc = bpf_jitter(fcode, flen);
1780#endif
1781	}
1782
1783	BPF_LOCK();
1784
1785	/*
1786	 * Set up new filter.
1787	 * Protect filter change by interface lock.
1788	 * Additionally, we are protected by global lock here.
1789	 */
1790	if (d->bd_bif != NULL)
1791		BPFIF_WLOCK(d->bd_bif);
1792	BPFD_LOCK(d);
1793	if (cmd == BIOCSETWF) {
1794		old = d->bd_wfilter;
1795		d->bd_wfilter = fcode;
1796	} else {
1797		old = d->bd_rfilter;
1798		d->bd_rfilter = fcode;
1799#ifdef BPF_JITTER
1800		ofunc = d->bd_bfilter;
1801		d->bd_bfilter = jfunc;
1802#endif
1803		if (cmd == BIOCSETF)
1804			reset_d(d);
1805
1806		if (fcode != NULL) {
1807			/*
1808			 * Do not require upgrade by first BIOCSETF
1809			 * (used to set snaplen) by pcap_open_live().
1810			 */
1811			if (d->bd_writer != 0 && --d->bd_writer == 0)
1812				need_upgrade = 1;
1813			CTR4(KTR_NET, "%s: filter function set by pid %d, "
1814			    "bd_writer counter %d, need_upgrade %d",
1815			    __func__, d->bd_pid, d->bd_writer, need_upgrade);
1816		}
1817	}
1818	BPFD_UNLOCK(d);
1819	if (d->bd_bif != NULL)
1820		BPFIF_WUNLOCK(d->bd_bif);
1821	if (old != NULL)
1822		free(old, M_BPF);
1823#ifdef BPF_JITTER
1824	if (ofunc != NULL)
1825		bpf_destroy_jit_filter(ofunc);
1826#endif
1827
1828	/* Move d to active readers list. */
1829	if (need_upgrade)
1830		bpf_upgraded(d);
1831
1832	BPF_UNLOCK();
1833	return (0);
1834}
1835
1836/*
1837 * Detach a file from its current interface (if attached at all) and attach
1838 * to the interface indicated by the name stored in ifr.
1839 * Return an errno or 0.
1840 */
1841static int
1842bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1843{
1844	struct bpf_if *bp;
1845	struct ifnet *theywant;
1846
1847	BPF_LOCK_ASSERT();
1848
1849	theywant = ifunit(ifr->ifr_name);
1850	if (theywant == NULL || theywant->if_bpf == NULL)
1851		return (ENXIO);
1852
1853	bp = theywant->if_bpf;
1854
1855	/* Check if interface is not being detached from BPF */
1856	BPFIF_RLOCK(bp);
1857	if (bp->flags & BPFIF_FLAG_DYING) {
1858		BPFIF_RUNLOCK(bp);
1859		return (ENXIO);
1860	}
1861	BPFIF_RUNLOCK(bp);
1862
1863	/*
1864	 * Behavior here depends on the buffering model.  If we're using
1865	 * kernel memory buffers, then we can allocate them here.  If we're
1866	 * using zero-copy, then the user process must have registered
1867	 * buffers by the time we get here.  If not, return an error.
1868	 */
1869	switch (d->bd_bufmode) {
1870	case BPF_BUFMODE_BUFFER:
1871	case BPF_BUFMODE_ZBUF:
1872		if (d->bd_sbuf == NULL)
1873			return (EINVAL);
1874		break;
1875
1876	default:
1877		panic("bpf_setif: bufmode %d", d->bd_bufmode);
1878	}
1879	if (bp != d->bd_bif)
1880		bpf_attachd(d, bp);
1881	BPFD_LOCK(d);
1882	reset_d(d);
1883	BPFD_UNLOCK(d);
1884	return (0);
1885}
1886
1887/*
1888 * Support for select() and poll() system calls
1889 *
1890 * Return true iff the specific operation will not block indefinitely.
1891 * Otherwise, return false but make a note that a selwakeup() must be done.
1892 */
1893static int
1894bpfpoll(struct cdev *dev, int events, struct thread *td)
1895{
1896	struct bpf_d *d;
1897	int revents;
1898
1899	if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
1900		return (events &
1901		    (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
1902
1903	/*
1904	 * Refresh PID associated with this descriptor.
1905	 */
1906	revents = events & (POLLOUT | POLLWRNORM);
1907	BPFD_LOCK(d);
1908	BPF_PID_REFRESH(d, td);
1909	if (events & (POLLIN | POLLRDNORM)) {
1910		if (bpf_ready(d))
1911			revents |= events & (POLLIN | POLLRDNORM);
1912		else {
1913			selrecord(td, &d->bd_sel);
1914			/* Start the read timeout if necessary. */
1915			if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1916				callout_reset(&d->bd_callout, d->bd_rtout,
1917				    bpf_timed_out, d);
1918				d->bd_state = BPF_WAITING;
1919			}
1920		}
1921	}
1922	BPFD_UNLOCK(d);
1923	return (revents);
1924}
1925
1926/*
1927 * Support for kevent() system call.  Register EVFILT_READ filters and
1928 * reject all others.
1929 */
1930int
1931bpfkqfilter(struct cdev *dev, struct knote *kn)
1932{
1933	struct bpf_d *d;
1934
1935	if (devfs_get_cdevpriv((void **)&d) != 0 ||
1936	    kn->kn_filter != EVFILT_READ)
1937		return (1);
1938
1939	/*
1940	 * Refresh PID associated with this descriptor.
1941	 */
1942	BPFD_LOCK(d);
1943	BPF_PID_REFRESH_CUR(d);
1944	kn->kn_fop = &bpfread_filtops;
1945	kn->kn_hook = d;
1946	knlist_add(&d->bd_sel.si_note, kn, 1);
1947	BPFD_UNLOCK(d);
1948
1949	return (0);
1950}
1951
1952static void
1953filt_bpfdetach(struct knote *kn)
1954{
1955	struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1956
1957	knlist_remove(&d->bd_sel.si_note, kn, 0);
1958}
1959
1960static int
1961filt_bpfread(struct knote *kn, long hint)
1962{
1963	struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1964	int ready;
1965
1966	BPFD_LOCK_ASSERT(d);
1967	ready = bpf_ready(d);
1968	if (ready) {
1969		kn->kn_data = d->bd_slen;
1970		while (d->bd_hbuf_in_use)
1971			mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
1972			    PRINET, "bd_hbuf", 0);
1973		if (d->bd_hbuf)
1974			kn->kn_data += d->bd_hlen;
1975	} else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1976		callout_reset(&d->bd_callout, d->bd_rtout,
1977		    bpf_timed_out, d);
1978		d->bd_state = BPF_WAITING;
1979	}
1980
1981	return (ready);
1982}
1983
1984#define	BPF_TSTAMP_NONE		0
1985#define	BPF_TSTAMP_FAST		1
1986#define	BPF_TSTAMP_NORMAL	2
1987#define	BPF_TSTAMP_EXTERN	3
1988
1989static int
1990bpf_ts_quality(int tstype)
1991{
1992
1993	if (tstype == BPF_T_NONE)
1994		return (BPF_TSTAMP_NONE);
1995	if ((tstype & BPF_T_FAST) != 0)
1996		return (BPF_TSTAMP_FAST);
1997
1998	return (BPF_TSTAMP_NORMAL);
1999}
2000
2001static int
2002bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m)
2003{
2004	struct m_tag *tag;
2005	int quality;
2006
2007	quality = bpf_ts_quality(tstype);
2008	if (quality == BPF_TSTAMP_NONE)
2009		return (quality);
2010
2011	if (m != NULL) {
2012		tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL);
2013		if (tag != NULL) {
2014			*bt = *(struct bintime *)(tag + 1);
2015			return (BPF_TSTAMP_EXTERN);
2016		}
2017	}
2018	if (quality == BPF_TSTAMP_NORMAL)
2019		binuptime(bt);
2020	else
2021		getbinuptime(bt);
2022
2023	return (quality);
2024}
2025
2026/*
2027 * Incoming linkage from device drivers.  Process the packet pkt, of length
2028 * pktlen, which is stored in a contiguous buffer.  The packet is parsed
2029 * by each process' filter, and if accepted, stashed into the corresponding
2030 * buffer.
2031 */
2032void
2033bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2034{
2035	struct bintime bt;
2036	struct bpf_d *d;
2037#ifdef BPF_JITTER
2038	bpf_jit_filter *bf;
2039#endif
2040	u_int slen;
2041	int gottime;
2042
2043	gottime = BPF_TSTAMP_NONE;
2044
2045	BPFIF_RLOCK(bp);
2046
2047	LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2048		/*
2049		 * We are not using any locks for d here because:
2050		 * 1) any filter change is protected by interface
2051		 * write lock
2052		 * 2) destroying/detaching d is protected by interface
2053		 * write lock, too
2054		 */
2055
2056		/* XXX: Do not protect counter for the sake of performance. */
2057		++d->bd_rcount;
2058		/*
2059		 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no
2060		 * way for the caller to indiciate to us whether this packet
2061		 * is inbound or outbound.  In the bpf_mtap() routines, we use
2062		 * the interface pointers on the mbuf to figure it out.
2063		 */
2064#ifdef BPF_JITTER
2065		bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2066		if (bf != NULL)
2067			slen = (*(bf->func))(pkt, pktlen, pktlen);
2068		else
2069#endif
2070		slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
2071		if (slen != 0) {
2072			/*
2073			 * Filter matches. Let's to acquire write lock.
2074			 */
2075			BPFD_LOCK(d);
2076
2077			d->bd_fcount++;
2078			if (gottime < bpf_ts_quality(d->bd_tstamp))
2079				gottime = bpf_gettime(&bt, d->bd_tstamp, NULL);
2080#ifdef MAC
2081			if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2082#endif
2083				catchpacket(d, pkt, pktlen, slen,
2084				    bpf_append_bytes, &bt);
2085			BPFD_UNLOCK(d);
2086		}
2087	}
2088	BPFIF_RUNLOCK(bp);
2089}
2090
2091#define	BPF_CHECK_DIRECTION(d, r, i)				\
2092	    (((d)->bd_direction == BPF_D_IN && (r) != (i)) ||	\
2093	    ((d)->bd_direction == BPF_D_OUT && (r) == (i)))
2094
2095/*
2096 * Incoming linkage from device drivers, when packet is in an mbuf chain.
2097 * Locking model is explained in bpf_tap().
2098 */
2099void
2100bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2101{
2102	struct bintime bt;
2103	struct bpf_d *d;
2104#ifdef BPF_JITTER
2105	bpf_jit_filter *bf;
2106#endif
2107	u_int pktlen, slen;
2108	int gottime;
2109
2110	/* Skip outgoing duplicate packets. */
2111	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2112		m->m_flags &= ~M_PROMISC;
2113		return;
2114	}
2115
2116	pktlen = m_length(m, NULL);
2117	gottime = BPF_TSTAMP_NONE;
2118
2119	BPFIF_RLOCK(bp);
2120
2121	LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2122		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2123			continue;
2124		++d->bd_rcount;
2125#ifdef BPF_JITTER
2126		bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2127		/* XXX We cannot handle multiple mbufs. */
2128		if (bf != NULL && m->m_next == NULL)
2129			slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
2130		else
2131#endif
2132		slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
2133		if (slen != 0) {
2134			BPFD_LOCK(d);
2135
2136			d->bd_fcount++;
2137			if (gottime < bpf_ts_quality(d->bd_tstamp))
2138				gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2139#ifdef MAC
2140			if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2141#endif
2142				catchpacket(d, (u_char *)m, pktlen, slen,
2143				    bpf_append_mbuf, &bt);
2144			BPFD_UNLOCK(d);
2145		}
2146	}
2147	BPFIF_RUNLOCK(bp);
2148}
2149
2150/*
2151 * Incoming linkage from device drivers, when packet is in
2152 * an mbuf chain and to be prepended by a contiguous header.
2153 */
2154void
2155bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
2156{
2157	struct bintime bt;
2158	struct mbuf mb;
2159	struct bpf_d *d;
2160	u_int pktlen, slen;
2161	int gottime;
2162
2163	/* Skip outgoing duplicate packets. */
2164	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2165		m->m_flags &= ~M_PROMISC;
2166		return;
2167	}
2168
2169	pktlen = m_length(m, NULL);
2170	/*
2171	 * Craft on-stack mbuf suitable for passing to bpf_filter.
2172	 * Note that we cut corners here; we only setup what's
2173	 * absolutely needed--this mbuf should never go anywhere else.
2174	 */
2175	mb.m_next = m;
2176	mb.m_data = data;
2177	mb.m_len = dlen;
2178	pktlen += dlen;
2179
2180	gottime = BPF_TSTAMP_NONE;
2181
2182	BPFIF_RLOCK(bp);
2183
2184	LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2185		if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2186			continue;
2187		++d->bd_rcount;
2188		slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
2189		if (slen != 0) {
2190			BPFD_LOCK(d);
2191
2192			d->bd_fcount++;
2193			if (gottime < bpf_ts_quality(d->bd_tstamp))
2194				gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2195#ifdef MAC
2196			if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2197#endif
2198				catchpacket(d, (u_char *)&mb, pktlen, slen,
2199				    bpf_append_mbuf, &bt);
2200			BPFD_UNLOCK(d);
2201		}
2202	}
2203	BPFIF_RUNLOCK(bp);
2204}
2205
2206#undef	BPF_CHECK_DIRECTION
2207
2208#undef	BPF_TSTAMP_NONE
2209#undef	BPF_TSTAMP_FAST
2210#undef	BPF_TSTAMP_NORMAL
2211#undef	BPF_TSTAMP_EXTERN
2212
2213static int
2214bpf_hdrlen(struct bpf_d *d)
2215{
2216	int hdrlen;
2217
2218	hdrlen = d->bd_bif->bif_hdrlen;
2219#ifndef BURN_BRIDGES
2220	if (d->bd_tstamp == BPF_T_NONE ||
2221	    BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME)
2222#ifdef COMPAT_FREEBSD32
2223		if (d->bd_compat32)
2224			hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32);
2225		else
2226#endif
2227			hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr);
2228	else
2229#endif
2230		hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr);
2231#ifdef COMPAT_FREEBSD32
2232	if (d->bd_compat32)
2233		hdrlen = BPF_WORDALIGN32(hdrlen);
2234	else
2235#endif
2236		hdrlen = BPF_WORDALIGN(hdrlen);
2237
2238	return (hdrlen - d->bd_bif->bif_hdrlen);
2239}
2240
2241static void
2242bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype)
2243{
2244	struct bintime bt2;
2245	struct timeval tsm;
2246	struct timespec tsn;
2247
2248	if ((tstype & BPF_T_MONOTONIC) == 0) {
2249		bt2 = *bt;
2250		bintime_add(&bt2, &boottimebin);
2251		bt = &bt2;
2252	}
2253	switch (BPF_T_FORMAT(tstype)) {
2254	case BPF_T_MICROTIME:
2255		bintime2timeval(bt, &tsm);
2256		ts->bt_sec = tsm.tv_sec;
2257		ts->bt_frac = tsm.tv_usec;
2258		break;
2259	case BPF_T_NANOTIME:
2260		bintime2timespec(bt, &tsn);
2261		ts->bt_sec = tsn.tv_sec;
2262		ts->bt_frac = tsn.tv_nsec;
2263		break;
2264	case BPF_T_BINTIME:
2265		ts->bt_sec = bt->sec;
2266		ts->bt_frac = bt->frac;
2267		break;
2268	}
2269}
2270
2271/*
2272 * Move the packet data from interface memory (pkt) into the
2273 * store buffer.  "cpfn" is the routine called to do the actual data
2274 * transfer.  bcopy is passed in to copy contiguous chunks, while
2275 * bpf_append_mbuf is passed in to copy mbuf chains.  In the latter case,
2276 * pkt is really an mbuf.
2277 */
2278static void
2279catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
2280    void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int),
2281    struct bintime *bt)
2282{
2283	struct bpf_xhdr hdr;
2284#ifndef BURN_BRIDGES
2285	struct bpf_hdr hdr_old;
2286#ifdef COMPAT_FREEBSD32
2287	struct bpf_hdr32 hdr32_old;
2288#endif
2289#endif
2290	int caplen, curlen, hdrlen, totlen;
2291	int do_wakeup = 0;
2292	int do_timestamp;
2293	int tstype;
2294
2295	BPFD_LOCK_ASSERT(d);
2296
2297	/*
2298	 * Detect whether user space has released a buffer back to us, and if
2299	 * so, move it from being a hold buffer to a free buffer.  This may
2300	 * not be the best place to do it (for example, we might only want to
2301	 * run this check if we need the space), but for now it's a reliable
2302	 * spot to do it.
2303	 */
2304	if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
2305		while (d->bd_hbuf_in_use)
2306			mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2307			    PRINET, "bd_hbuf", 0);
2308		d->bd_fbuf = d->bd_hbuf;
2309		d->bd_hbuf = NULL;
2310		d->bd_hlen = 0;
2311		bpf_buf_reclaimed(d);
2312	}
2313
2314	/*
2315	 * Figure out how many bytes to move.  If the packet is
2316	 * greater or equal to the snapshot length, transfer that
2317	 * much.  Otherwise, transfer the whole packet (unless
2318	 * we hit the buffer size limit).
2319	 */
2320	hdrlen = bpf_hdrlen(d);
2321	totlen = hdrlen + min(snaplen, pktlen);
2322	if (totlen > d->bd_bufsize)
2323		totlen = d->bd_bufsize;
2324
2325	/*
2326	 * Round up the end of the previous packet to the next longword.
2327	 *
2328	 * Drop the packet if there's no room and no hope of room
2329	 * If the packet would overflow the storage buffer or the storage
2330	 * buffer is considered immutable by the buffer model, try to rotate
2331	 * the buffer and wakeup pending processes.
2332	 */
2333#ifdef COMPAT_FREEBSD32
2334	if (d->bd_compat32)
2335		curlen = BPF_WORDALIGN32(d->bd_slen);
2336	else
2337#endif
2338		curlen = BPF_WORDALIGN(d->bd_slen);
2339	if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
2340		if (d->bd_fbuf == NULL) {
2341			/*
2342			 * There's no room in the store buffer, and no
2343			 * prospect of room, so drop the packet.  Notify the
2344			 * buffer model.
2345			 */
2346			bpf_buffull(d);
2347			++d->bd_dcount;
2348			return;
2349		}
2350		while (d->bd_hbuf_in_use)
2351			mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2352			    PRINET, "bd_hbuf", 0);
2353		ROTATE_BUFFERS(d);
2354		do_wakeup = 1;
2355		curlen = 0;
2356	} else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
2357		/*
2358		 * Immediate mode is set, or the read timeout has already
2359		 * expired during a select call.  A packet arrived, so the
2360		 * reader should be woken up.
2361		 */
2362		do_wakeup = 1;
2363	caplen = totlen - hdrlen;
2364	tstype = d->bd_tstamp;
2365	do_timestamp = tstype != BPF_T_NONE;
2366#ifndef BURN_BRIDGES
2367	if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) {
2368		struct bpf_ts ts;
2369		if (do_timestamp)
2370			bpf_bintime2ts(bt, &ts, tstype);
2371#ifdef COMPAT_FREEBSD32
2372		if (d->bd_compat32) {
2373			bzero(&hdr32_old, sizeof(hdr32_old));
2374			if (do_timestamp) {
2375				hdr32_old.bh_tstamp.tv_sec = ts.bt_sec;
2376				hdr32_old.bh_tstamp.tv_usec = ts.bt_frac;
2377			}
2378			hdr32_old.bh_datalen = pktlen;
2379			hdr32_old.bh_hdrlen = hdrlen;
2380			hdr32_old.bh_caplen = caplen;
2381			bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old,
2382			    sizeof(hdr32_old));
2383			goto copy;
2384		}
2385#endif
2386		bzero(&hdr_old, sizeof(hdr_old));
2387		if (do_timestamp) {
2388			hdr_old.bh_tstamp.tv_sec = ts.bt_sec;
2389			hdr_old.bh_tstamp.tv_usec = ts.bt_frac;
2390		}
2391		hdr_old.bh_datalen = pktlen;
2392		hdr_old.bh_hdrlen = hdrlen;
2393		hdr_old.bh_caplen = caplen;
2394		bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old,
2395		    sizeof(hdr_old));
2396		goto copy;
2397	}
2398#endif
2399
2400	/*
2401	 * Append the bpf header.  Note we append the actual header size, but
2402	 * move forward the length of the header plus padding.
2403	 */
2404	bzero(&hdr, sizeof(hdr));
2405	if (do_timestamp)
2406		bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype);
2407	hdr.bh_datalen = pktlen;
2408	hdr.bh_hdrlen = hdrlen;
2409	hdr.bh_caplen = caplen;
2410	bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
2411
2412	/*
2413	 * Copy the packet data into the store buffer and update its length.
2414	 */
2415#ifndef BURN_BRIDGES
2416copy:
2417#endif
2418	(*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen);
2419	d->bd_slen = curlen + totlen;
2420
2421	if (do_wakeup)
2422		bpf_wakeup(d);
2423}
2424
2425/*
2426 * Free buffers currently in use by a descriptor.
2427 * Called on close.
2428 */
2429static void
2430bpf_freed(struct bpf_d *d)
2431{
2432
2433	/*
2434	 * We don't need to lock out interrupts since this descriptor has
2435	 * been detached from its interface and it yet hasn't been marked
2436	 * free.
2437	 */
2438	bpf_free(d);
2439	if (d->bd_rfilter != NULL) {
2440		free((caddr_t)d->bd_rfilter, M_BPF);
2441#ifdef BPF_JITTER
2442		if (d->bd_bfilter != NULL)
2443			bpf_destroy_jit_filter(d->bd_bfilter);
2444#endif
2445	}
2446	if (d->bd_wfilter != NULL)
2447		free((caddr_t)d->bd_wfilter, M_BPF);
2448	mtx_destroy(&d->bd_lock);
2449}
2450
2451/*
2452 * Attach an interface to bpf.  dlt is the link layer type; hdrlen is the
2453 * fixed size of the link header (variable length headers not yet supported).
2454 */
2455void
2456bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2457{
2458
2459	bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2460}
2461
2462/*
2463 * Attach an interface to bpf.  ifp is a pointer to the structure
2464 * defining the interface to be attached, dlt is the link layer type,
2465 * and hdrlen is the fixed size of the link header (variable length
2466 * headers are not yet supporrted).
2467 */
2468void
2469bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2470{
2471	struct bpf_if *bp;
2472
2473	bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
2474	if (bp == NULL)
2475		panic("bpfattach");
2476
2477	LIST_INIT(&bp->bif_dlist);
2478	LIST_INIT(&bp->bif_wlist);
2479	bp->bif_ifp = ifp;
2480	bp->bif_dlt = dlt;
2481	rw_init(&bp->bif_lock, "bpf interface lock");
2482	KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
2483	*driverp = bp;
2484
2485	BPF_LOCK();
2486	LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
2487	BPF_UNLOCK();
2488
2489	bp->bif_hdrlen = hdrlen;
2490
2491	if (bootverbose)
2492		if_printf(ifp, "bpf attached\n");
2493}
2494
2495/*
2496 * Detach bpf from an interface. This involves detaching each descriptor
2497 * associated with the interface. Notify each descriptor as it's detached
2498 * so that any sleepers wake up and get ENXIO.
2499 */
2500void
2501bpfdetach(struct ifnet *ifp)
2502{
2503	struct bpf_if	*bp, *bp_temp;
2504	struct bpf_d	*d;
2505	int ndetached;
2506
2507	ndetached = 0;
2508
2509	BPF_LOCK();
2510	/* Find all bpf_if struct's which reference ifp and detach them. */
2511	LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) {
2512		if (ifp != bp->bif_ifp)
2513			continue;
2514
2515		LIST_REMOVE(bp, bif_next);
2516		/* Add to to-be-freed list */
2517		LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next);
2518
2519		ndetached++;
2520		/*
2521		 * Delay freeing bp till interface is detached
2522		 * and all routes through this interface are removed.
2523		 * Mark bp as detached to restrict new consumers.
2524		 */
2525		BPFIF_WLOCK(bp);
2526		bp->flags |= BPFIF_FLAG_DYING;
2527		BPFIF_WUNLOCK(bp);
2528
2529		CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p",
2530		    __func__, bp->bif_dlt, bp, ifp);
2531
2532		/* Free common descriptors */
2533		while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
2534			bpf_detachd_locked(d);
2535			BPFD_LOCK(d);
2536			bpf_wakeup(d);
2537			BPFD_UNLOCK(d);
2538		}
2539
2540		/* Free writer-only descriptors */
2541		while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) {
2542			bpf_detachd_locked(d);
2543			BPFD_LOCK(d);
2544			bpf_wakeup(d);
2545			BPFD_UNLOCK(d);
2546		}
2547	}
2548	BPF_UNLOCK();
2549
2550#ifdef INVARIANTS
2551	if (ndetached == 0)
2552		printf("bpfdetach: %s was not attached\n", ifp->if_xname);
2553#endif
2554}
2555
2556/*
2557 * Interface departure handler.
2558 * Note departure event does not guarantee interface is going down.
2559 * Interface renaming is currently done via departure/arrival event set.
2560 *
2561 * Departure handled is called after all routes pointing to
2562 * given interface are removed and interface is in down state
2563 * restricting any packets to be sent/received. We assume it is now safe
2564 * to free data allocated by BPF.
2565 */
2566static void
2567bpf_ifdetach(void *arg __unused, struct ifnet *ifp)
2568{
2569	struct bpf_if *bp, *bp_temp;
2570	int nmatched = 0;
2571
2572	BPF_LOCK();
2573	/*
2574	 * Find matching entries in free list.
2575	 * Nothing should be found if bpfdetach() was not called.
2576	 */
2577	LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) {
2578		if (ifp != bp->bif_ifp)
2579			continue;
2580
2581		CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p",
2582		    __func__, bp, ifp);
2583
2584		LIST_REMOVE(bp, bif_next);
2585
2586		rw_destroy(&bp->bif_lock);
2587		free(bp, M_BPF);
2588
2589		nmatched++;
2590	}
2591	BPF_UNLOCK();
2592
2593	/*
2594	 * Note that we cannot zero other pointers to
2595	 * custom DLTs possibly used by given interface.
2596	 */
2597	if (nmatched != 0)
2598		ifp->if_bpf = NULL;
2599}
2600
2601/*
2602 * Get a list of available data link type of the interface.
2603 */
2604static int
2605bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
2606{
2607	int n, error;
2608	struct ifnet *ifp;
2609	struct bpf_if *bp;
2610
2611	BPF_LOCK_ASSERT();
2612
2613	ifp = d->bd_bif->bif_ifp;
2614	n = 0;
2615	error = 0;
2616	LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2617		if (bp->bif_ifp != ifp)
2618			continue;
2619		if (bfl->bfl_list != NULL) {
2620			if (n >= bfl->bfl_len)
2621				return (ENOMEM);
2622			error = copyout(&bp->bif_dlt,
2623			    bfl->bfl_list + n, sizeof(u_int));
2624		}
2625		n++;
2626	}
2627	bfl->bfl_len = n;
2628	return (error);
2629}
2630
2631/*
2632 * Set the data link type of a BPF instance.
2633 */
2634static int
2635bpf_setdlt(struct bpf_d *d, u_int dlt)
2636{
2637	int error, opromisc;
2638	struct ifnet *ifp;
2639	struct bpf_if *bp;
2640
2641	BPF_LOCK_ASSERT();
2642
2643	if (d->bd_bif->bif_dlt == dlt)
2644		return (0);
2645	ifp = d->bd_bif->bif_ifp;
2646
2647	LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2648		if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
2649			break;
2650	}
2651
2652	if (bp != NULL) {
2653		opromisc = d->bd_promisc;
2654		bpf_attachd(d, bp);
2655		BPFD_LOCK(d);
2656		reset_d(d);
2657		BPFD_UNLOCK(d);
2658		if (opromisc) {
2659			error = ifpromisc(bp->bif_ifp, 1);
2660			if (error)
2661				if_printf(bp->bif_ifp,
2662					"bpf_setdlt: ifpromisc failed (%d)\n",
2663					error);
2664			else
2665				d->bd_promisc = 1;
2666		}
2667	}
2668	return (bp == NULL ? EINVAL : 0);
2669}
2670
2671static void
2672bpf_drvinit(void *unused)
2673{
2674	struct cdev *dev;
2675
2676	mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
2677	LIST_INIT(&bpf_iflist);
2678	LIST_INIT(&bpf_freelist);
2679
2680	dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
2681	/* For compatibility */
2682	make_dev_alias(dev, "bpf0");
2683
2684	/* Register interface departure handler */
2685	bpf_ifdetach_cookie = EVENTHANDLER_REGISTER(
2686		    ifnet_departure_event, bpf_ifdetach, NULL,
2687		    EVENTHANDLER_PRI_ANY);
2688}
2689
2690/*
2691 * Zero out the various packet counters associated with all of the bpf
2692 * descriptors.  At some point, we will probably want to get a bit more
2693 * granular and allow the user to specify descriptors to be zeroed.
2694 */
2695static void
2696bpf_zero_counters(void)
2697{
2698	struct bpf_if *bp;
2699	struct bpf_d *bd;
2700
2701	BPF_LOCK();
2702	LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2703		BPFIF_RLOCK(bp);
2704		LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2705			BPFD_LOCK(bd);
2706			bd->bd_rcount = 0;
2707			bd->bd_dcount = 0;
2708			bd->bd_fcount = 0;
2709			bd->bd_wcount = 0;
2710			bd->bd_wfcount = 0;
2711			bd->bd_zcopy = 0;
2712			BPFD_UNLOCK(bd);
2713		}
2714		BPFIF_RUNLOCK(bp);
2715	}
2716	BPF_UNLOCK();
2717}
2718
2719/*
2720 * Fill filter statistics
2721 */
2722static void
2723bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
2724{
2725
2726	bzero(d, sizeof(*d));
2727	BPFD_LOCK_ASSERT(bd);
2728	d->bd_structsize = sizeof(*d);
2729	/* XXX: reading should be protected by global lock */
2730	d->bd_immediate = bd->bd_immediate;
2731	d->bd_promisc = bd->bd_promisc;
2732	d->bd_hdrcmplt = bd->bd_hdrcmplt;
2733	d->bd_direction = bd->bd_direction;
2734	d->bd_feedback = bd->bd_feedback;
2735	d->bd_async = bd->bd_async;
2736	d->bd_rcount = bd->bd_rcount;
2737	d->bd_dcount = bd->bd_dcount;
2738	d->bd_fcount = bd->bd_fcount;
2739	d->bd_sig = bd->bd_sig;
2740	d->bd_slen = bd->bd_slen;
2741	d->bd_hlen = bd->bd_hlen;
2742	d->bd_bufsize = bd->bd_bufsize;
2743	d->bd_pid = bd->bd_pid;
2744	strlcpy(d->bd_ifname,
2745	    bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
2746	d->bd_locked = bd->bd_locked;
2747	d->bd_wcount = bd->bd_wcount;
2748	d->bd_wdcount = bd->bd_wdcount;
2749	d->bd_wfcount = bd->bd_wfcount;
2750	d->bd_zcopy = bd->bd_zcopy;
2751	d->bd_bufmode = bd->bd_bufmode;
2752}
2753
2754/*
2755 * Handle `netstat -B' stats request
2756 */
2757static int
2758bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
2759{
2760	static const struct xbpf_d zerostats;
2761	struct xbpf_d *xbdbuf, *xbd, tempstats;
2762	int index, error;
2763	struct bpf_if *bp;
2764	struct bpf_d *bd;
2765
2766	/*
2767	 * XXX This is not technically correct. It is possible for non
2768	 * privileged users to open bpf devices. It would make sense
2769	 * if the users who opened the devices were able to retrieve
2770	 * the statistics for them, too.
2771	 */
2772	error = priv_check(req->td, PRIV_NET_BPF);
2773	if (error)
2774		return (error);
2775	/*
2776	 * Check to see if the user is requesting that the counters be
2777	 * zeroed out.  Explicitly check that the supplied data is zeroed,
2778	 * as we aren't allowing the user to set the counters currently.
2779	 */
2780	if (req->newptr != NULL) {
2781		if (req->newlen != sizeof(tempstats))
2782			return (EINVAL);
2783		memset(&tempstats, 0, sizeof(tempstats));
2784		error = SYSCTL_IN(req, &tempstats, sizeof(tempstats));
2785		if (error)
2786			return (error);
2787		if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0)
2788			return (EINVAL);
2789		bpf_zero_counters();
2790		return (0);
2791	}
2792	if (req->oldptr == NULL)
2793		return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
2794	if (bpf_bpfd_cnt == 0)
2795		return (SYSCTL_OUT(req, 0, 0));
2796	xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
2797	BPF_LOCK();
2798	if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
2799		BPF_UNLOCK();
2800		free(xbdbuf, M_BPF);
2801		return (ENOMEM);
2802	}
2803	index = 0;
2804	LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2805		BPFIF_RLOCK(bp);
2806		/* Send writers-only first */
2807		LIST_FOREACH(bd, &bp->bif_wlist, bd_next) {
2808			xbd = &xbdbuf[index++];
2809			BPFD_LOCK(bd);
2810			bpfstats_fill_xbpf(xbd, bd);
2811			BPFD_UNLOCK(bd);
2812		}
2813		LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2814			xbd = &xbdbuf[index++];
2815			BPFD_LOCK(bd);
2816			bpfstats_fill_xbpf(xbd, bd);
2817			BPFD_UNLOCK(bd);
2818		}
2819		BPFIF_RUNLOCK(bp);
2820	}
2821	BPF_UNLOCK();
2822	error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
2823	free(xbdbuf, M_BPF);
2824	return (error);
2825}
2826
2827SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
2828
2829#else /* !DEV_BPF && !NETGRAPH_BPF */
2830/*
2831 * NOP stubs to allow bpf-using drivers to load and function.
2832 *
2833 * A 'better' implementation would allow the core bpf functionality
2834 * to be loaded at runtime.
2835 */
2836static struct bpf_if bp_null;
2837
2838void
2839bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2840{
2841}
2842
2843void
2844bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2845{
2846}
2847
2848void
2849bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
2850{
2851}
2852
2853void
2854bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2855{
2856
2857	bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2858}
2859
2860void
2861bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2862{
2863
2864	*driverp = &bp_null;
2865}
2866
2867void
2868bpfdetach(struct ifnet *ifp)
2869{
2870}
2871
2872u_int
2873bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
2874{
2875	return -1;	/* "no filter" behaviour */
2876}
2877
2878int
2879bpf_validate(const struct bpf_insn *f, int len)
2880{
2881	return 0;		/* false */
2882}
2883
2884#endif /* !DEV_BPF && !NETGRAPH_BPF */
2885