1/*
2 * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1990, 1991, 1993
30 *	The Regents of the University of California.  All rights reserved.
31 *
32 * This code is derived from the Stanford/CMU enet packet filter,
33 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
34 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
35 * Berkeley Laboratory.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in the
44 *    documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 *    must display the following acknowledgement:
47 *	This product includes software developed by the University of
48 *	California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 *    may be used to endorse or promote products derived from this software
51 *    without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 *      @(#)bpf.h	8.1 (Berkeley) 6/10/93
66 *	@(#)bpf.h	1.34 (LBL)     6/16/96
67 *
68 * $FreeBSD: src/sys/net/bpf.h,v 1.21.2.3 2001/08/01 00:23:13 fenner Exp $
69 */
70/*
71 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
72 * support for mandatory and extensible security protections.  This notice
73 * is included in support of clause 2.2 (b) of the Apple Public License,
74 * Version 2.0.
75 */
76
77#ifndef _NET_BPF_H_
78#define _NET_BPF_H_
79#include <sys/param.h>
80#include <sys/appleapiopts.h>
81#include <sys/types.h>
82#include <sys/time.h>
83#include <sys/cdefs.h>
84
85#ifdef KERNEL
86#include <sys/kernel_types.h>
87#endif
88
89/* BSD style release date */
90#define	BPF_RELEASE 199606
91
92typedef	int32_t	  bpf_int32;
93typedef	u_int32_t bpf_u_int32;
94
95/*
96 * Alignment macros.  BPF_WORDALIGN rounds up to the next
97 * even multiple of BPF_ALIGNMENT.
98 */
99#define BPF_ALIGNMENT sizeof(int32_t)
100#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
101
102#define BPF_MAXINSNS 512
103#define BPF_MAXBUFSIZE 0x80000
104#define BPF_MINBUFSIZE 32
105
106/*
107 *  Structure for BIOCSETF.
108 */
109struct bpf_program {
110	u_int bf_len;
111	struct bpf_insn *bf_insns;
112};
113
114#ifdef KERNEL_PRIVATE
115/* LP64 version of bpf_program.  all pointers
116 * grow when we're dealing with a 64-bit process.
117 * WARNING - keep in sync with bpf_program
118 */
119struct bpf_program64 {
120	u_int		bf_len;
121	user64_addr_t	bf_insns __attribute__((aligned(8)));
122};
123
124struct bpf_program32 {
125	u_int		bf_len;
126	user32_addr_t	bf_insns;
127};
128#endif /* KERNEL_PRIVATE */
129
130/*
131 * Struct returned by BIOCGSTATS.
132 */
133struct bpf_stat {
134	u_int bs_recv;		/* number of packets received */
135	u_int bs_drop;		/* number of packets dropped */
136};
137
138/*
139 * Struct return by BIOCVERSION.  This represents the version number of
140 * the filter language described by the instruction encodings below.
141 * bpf understands a program iff kernel_major == filter_major &&
142 * kernel_minor >= filter_minor, that is, if the value returned by the
143 * running kernel has the same major number and a minor number equal
144 * equal to or less than the filter being downloaded.  Otherwise, the
145 * results are undefined, meaning an error may be returned or packets
146 * may be accepted haphazardly.
147 * It has nothing to do with the source code version.
148 */
149struct bpf_version {
150	u_short bv_major;
151	u_short bv_minor;
152};
153#if defined(__LP64__)
154#define __need_struct_timeval32
155#include <sys/_structs.h>
156#define BPF_TIMEVAL timeval32
157#else
158#define BPF_TIMEVAL timeval
159#endif /* __LP64__ */
160/* Current version number of filter architecture. */
161#define BPF_MAJOR_VERSION 1
162#define BPF_MINOR_VERSION 1
163
164#define	BIOCGBLEN	_IOR('B',102, u_int)
165#define	BIOCSBLEN	_IOWR('B',102, u_int)
166#define	BIOCSETF	_IOW('B',103, struct bpf_program)
167#ifdef KERNEL_PRIVATE
168#define	BIOCSETF64	_IOW('B',103, struct bpf_program64)
169#define	BIOCSETF32	_IOW('B',103, struct bpf_program32)
170#endif /* KERNEL_PRIVATE */
171#define	BIOCFLUSH	_IO('B',104)
172#define BIOCPROMISC	_IO('B',105)
173#define	BIOCGDLT	_IOR('B',106, u_int)
174#define BIOCGETIF	_IOR('B',107, struct ifreq)
175#define BIOCSETIF	_IOW('B',108, struct ifreq)
176#define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
177#ifdef KERNEL_PRIVATE
178#define BIOCSRTIMEOUT64	_IOW('B',109, struct user64_timeval)
179#define BIOCSRTIMEOUT32	_IOW('B',109, struct user32_timeval)
180#endif /* KERNEL_PRIVATE */
181#define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
182#ifdef KERNEL_PRIVATE
183#define BIOCGRTIMEOUT64	_IOR('B',110, struct user64_timeval)
184#define BIOCGRTIMEOUT32	_IOR('B',110, struct user32_timeval)
185#endif /* KERNEL_PRIVATE */
186#define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
187#define BIOCIMMEDIATE	_IOW('B',112, u_int)
188#define BIOCVERSION	_IOR('B',113, struct bpf_version)
189#define BIOCGRSIG	_IOR('B',114, u_int)
190#define BIOCSRSIG	_IOW('B',115, u_int)
191#define BIOCGHDRCMPLT	_IOR('B',116, u_int)
192#define BIOCSHDRCMPLT	_IOW('B',117, u_int)
193#define BIOCGSEESENT	_IOR('B',118, u_int)
194#define BIOCSSEESENT	_IOW('B',119, u_int)
195#define BIOCSDLT        _IOW('B',120, u_int)
196#define BIOCGDLTLIST    _IOWR('B',121, struct bpf_dltlist)
197#ifdef PRIVATE
198#define	BIOCGETTC	_IOR('B', 122, int)
199#define	BIOCSETTC	_IOW('B', 123, int)
200#define	BIOCSEXTHDR	_IOW('B', 124, u_int)
201#endif /* PRIVATE */
202
203/*
204 * Structure prepended to each packet.
205 */
206struct bpf_hdr {
207	struct BPF_TIMEVAL bh_tstamp;	/* time stamp */
208	bpf_u_int32	bh_caplen;	/* length of captured portion */
209	bpf_u_int32	bh_datalen;	/* original length of packet */
210	u_short		bh_hdrlen;	/* length of bpf header (this struct
211					   plus alignment padding) */
212};
213#ifdef KERNEL
214/*
215 * Because the structure above is not a multiple of 4 bytes, some compilers
216 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
217 * Only the kernel needs to know about it; applications use bh_hdrlen.
218 */
219#define	SIZEOF_BPF_HDR	(sizeof(struct bpf_hdr) <= 20 ? 18 : \
220    sizeof(struct bpf_hdr))
221#endif
222#ifdef PRIVATE
223/*
224 * This structure must be a multiple of 4 bytes.
225 * It includes padding and spare fields that we can use later if desired.
226 */
227struct bpf_hdr_ext {
228	struct BPF_TIMEVAL bh_tstamp;	/* time stamp */
229	bpf_u_int32	bh_caplen;	/* length of captured portion */
230	bpf_u_int32	bh_datalen;	/* original length of packet */
231	u_short		bh_hdrlen;	/* length of bpf header */
232	u_short		bh_flags;
233#define BPF_HDR_EXT_FLAGS_DIR_IN	0x0000
234#define BPF_HDR_EXT_FLAGS_DIR_OUT	0x0001
235#define	BPF_HDR_EXT_FLAGS_TCP		0x0002
236	pid_t		bh_pid;		/* process PID */
237	char		bh_comm[MAXCOMLEN+1]; /* process command */
238	u_char		_bh_pad2[3];
239	bpf_u_int32	bh_svc;		/* service class */
240	bpf_u_int32	bh_flowhash;	/* kernel reserved; 0 in userland */
241};
242#endif /* PRIVATE */
243
244/*
245 * Data-link level type codes.
246 */
247#define DLT_NULL	0	/* no link-layer encapsulation */
248#define DLT_EN10MB	1	/* Ethernet (10Mb) */
249#define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
250#define DLT_AX25	3	/* Amateur Radio AX.25 */
251#define DLT_PRONET	4	/* Proteon ProNET Token Ring */
252#define DLT_CHAOS	5	/* Chaos */
253#define DLT_IEEE802	6	/* IEEE 802 Networks */
254#define DLT_ARCNET	7	/* ARCNET */
255#define DLT_SLIP	8	/* Serial Line IP */
256#define DLT_PPP		9	/* Point-to-point Protocol */
257#define DLT_FDDI	10	/* FDDI */
258#define DLT_ATM_RFC1483	11	/* LLC/SNAP encapsulated atm */
259#define DLT_RAW		12	/* raw IP */
260
261/*
262 * These are values from BSD/OS's "bpf.h".
263 * These are not the same as the values from the traditional libpcap
264 * "bpf.h"; however, these values shouldn't be generated by any
265 * OS other than BSD/OS, so the correct values to use here are the
266 * BSD/OS values.
267 *
268 * Platforms that have already assigned these values to other
269 * DLT_ codes, however, should give these codes the values
270 * from that platform, so that programs that use these codes will
271 * continue to compile - even though they won't correctly read
272 * files of these types.
273 */
274#define DLT_SLIP_BSDOS	15	/* BSD/OS Serial Line IP */
275#define DLT_PPP_BSDOS	16	/* BSD/OS Point-to-point Protocol */
276
277#define	DLT_PFSYNC	18	/* Packet filter state syncing */
278#define DLT_ATM_CLIP	19	/* Linux Classical-IP over ATM */
279
280/*
281 * This value is defined by NetBSD; other platforms should refrain from
282 * using it for other purposes, so that NetBSD savefiles with a link
283 * type of 50 can be read as this type on all platforms.
284 */
285#define DLT_PPP_SERIAL	50	/* PPP over serial with HDLC encapsulation */
286
287/*
288 * This value was defined by libpcap 0.5; platforms that have defined
289 * it with a different value should define it here with that value -
290 * a link type of 104 in a save file will be mapped to DLT_C_HDLC,
291 * whatever value that happens to be, so programs will correctly
292 * handle files with that link type regardless of the value of
293 * DLT_C_HDLC.
294 *
295 * The name DLT_C_HDLC was used by BSD/OS; we use that name for source
296 * compatibility with programs written for BSD/OS.
297 *
298 * libpcap 0.5 defined it as DLT_CHDLC; we define DLT_CHDLC as well,
299 * for source compatibility with programs written for libpcap 0.5.
300 */
301#define DLT_C_HDLC	104	/* Cisco HDLC */
302#define DLT_CHDLC	DLT_C_HDLC
303
304/*
305 * Reserved for future use.
306 * Do not pick other numerical value for these unless you have also
307 * picked up the tcpdump.org top-of-CVS-tree version of "savefile.c",
308 * which will arrange that capture files for these DLT_ types have
309 * the same "network" value on all platforms, regardless of what
310 * value is chosen for their DLT_ type (thus allowing captures made
311 * on one platform to be read on other platforms, even if the two
312 * platforms don't use the same numerical values for all DLT_ types).
313 */
314#define DLT_IEEE802_11	105	/* IEEE 802.11 wireless */
315
316/*
317 * Values between 106 and 107 are used in capture file headers as
318 * link-layer types corresponding to DLT_ types that might differ
319 * between platforms; don't use those values for new DLT_ new types.
320 */
321
322/*
323 * OpenBSD DLT_LOOP, for loopback devices; it's like DLT_NULL, except
324 * that the AF_ type in the link-layer header is in network byte order.
325 *
326 * OpenBSD defines it as 12, but that collides with DLT_RAW, so we
327 * define it as 108 here.  If OpenBSD picks up this file, it should
328 * define DLT_LOOP as 12 in its version, as per the comment above -
329 * and should not use 108 for any purpose.
330 */
331#define DLT_LOOP	108
332
333/*
334 * Values between 109 and 112 are used in capture file headers as
335 * link-layer types corresponding to DLT_ types that might differ
336 * between platforms; don't use those values for new DLT_ new types.
337 */
338
339/*
340 * This is for Linux cooked sockets.
341 */
342#define DLT_LINUX_SLL	113
343
344/*
345 * For use in capture-file headers as a link-layer type corresponding
346 * to OpenBSD PF (Packet Filter) log.
347 */
348#define	DLT_PFLOG	117
349
350/*
351 * BSD header for 802.11 plus a number of bits of link-layer information
352 * including radio information.
353 */
354#ifndef DLT_IEEE802_11_RADIO
355#define DLT_IEEE802_11_RADIO	127
356#endif
357
358/*
359 * Apple IP-over-IEEE 1394, as per a request from Dieter Siegmund
360 * <dieter@apple.com>.  The header that's presented is an Ethernet-like
361 * header:
362 *
363 *	#define FIREWIRE_EUI64_LEN	8
364 *	struct firewire_header {
365 *		u_char  firewire_dhost[FIREWIRE_EUI64_LEN];
366 *		u_char  firewire_shost[FIREWIRE_EUI64_LEN];
367 *		u_short firewire_type;
368 *	};
369 *
370 * with "firewire_type" being an Ethernet type value, rather than,
371 * for example, raw GASP frames being handed up.
372 */
373#define DLT_APPLE_IP_OVER_IEEE1394	138
374
375/*
376 * For future use with 802.11 captures - defined by AbsoluteValue
377 * Systems to store a number of bits of link-layer information
378 * including radio information:
379 *
380 *	http://www.shaftnet.org/~pizza/software/capturefrm.txt
381 *
382 * but it might be used by some non-AVS drivers now or in the
383 * future.
384 */
385#define DLT_IEEE802_11_RADIO_AVS 163	/* 802.11 plus AVS radio header */
386
387
388/*
389 * The instruction encodings.
390 */
391/* instruction classes */
392#define BPF_CLASS(code) ((code) & 0x07)
393#define		BPF_LD		0x00
394#define		BPF_LDX		0x01
395#define		BPF_ST		0x02
396#define		BPF_STX		0x03
397#define		BPF_ALU		0x04
398#define		BPF_JMP		0x05
399#define		BPF_RET		0x06
400#define		BPF_MISC	0x07
401
402/* ld/ldx fields */
403#define BPF_SIZE(code)	((code) & 0x18)
404#define		BPF_W		0x00
405#define		BPF_H		0x08
406#define		BPF_B		0x10
407#define BPF_MODE(code)	((code) & 0xe0)
408#define		BPF_IMM 	0x00
409#define		BPF_ABS		0x20
410#define		BPF_IND		0x40
411#define		BPF_MEM		0x60
412#define		BPF_LEN		0x80
413#define		BPF_MSH		0xa0
414
415/* alu/jmp fields */
416#define BPF_OP(code)	((code) & 0xf0)
417#define		BPF_ADD		0x00
418#define		BPF_SUB		0x10
419#define		BPF_MUL		0x20
420#define		BPF_DIV		0x30
421#define		BPF_OR		0x40
422#define		BPF_AND		0x50
423#define		BPF_LSH		0x60
424#define		BPF_RSH		0x70
425#define		BPF_NEG		0x80
426#define		BPF_JA		0x00
427#define		BPF_JEQ		0x10
428#define		BPF_JGT		0x20
429#define		BPF_JGE		0x30
430#define		BPF_JSET	0x40
431#define BPF_SRC(code)	((code) & 0x08)
432#define		BPF_K		0x00
433#define		BPF_X		0x08
434
435/* ret - BPF_K and BPF_X also apply */
436#define BPF_RVAL(code)	((code) & 0x18)
437#define		BPF_A		0x10
438
439/* misc */
440#define BPF_MISCOP(code) ((code) & 0xf8)
441#define		BPF_TAX		0x00
442#define		BPF_TXA		0x80
443
444/*
445 * The instruction data structure.
446 */
447struct bpf_insn {
448	u_short		code;
449	u_char		jt;
450	u_char		jf;
451	bpf_u_int32	k;
452};
453
454/*
455 * Macros for insn array initializers.
456 */
457#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
458#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
459
460#pragma pack(4)
461
462/*
463 * Structure to retrieve available DLTs for the interface.
464 */
465struct bpf_dltlist {
466	u_int32_t		bfl_len;	/* number of bfd_list array */
467	union {
468		u_int32_t	*bflu_list;	/* array of DLTs */
469		u_int64_t	bflu_pad;
470	} bfl_u;
471};
472#define bfl_list bfl_u.bflu_list
473
474#pragma pack()
475
476#ifdef KERNEL_PRIVATE
477/* Forward declerations */
478struct ifnet;
479struct mbuf;
480
481extern int	bpf_validate(const struct bpf_insn *, int);
482extern void	bpfdetach(struct ifnet *);
483extern void	bpfilterattach(int);
484extern u_int	bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
485#endif /* KERNEL_PRIVATE */
486
487#ifdef KERNEL
488#ifndef BPF_TAP_MODE_T
489#define BPF_TAP_MODE_T
490/*!
491	@enum BPF tap mode
492	@abstract Constants defining interface families.
493	@constant BPF_MODE_DISABLED Disable bpf.
494	@constant BPF_MODE_INPUT Enable input only.
495	@constant BPF_MODE_OUTPUT Enable output only.
496	@constant BPF_MODE_INPUT_OUTPUT Enable input and output.
497*/
498
499enum {
500	BPF_MODE_DISABLED	= 0,
501	BPF_MODE_INPUT		= 1,
502	BPF_MODE_OUTPUT		= 2,
503	BPF_MODE_INPUT_OUTPUT	= 3
504};
505/*!
506	@typedef bpf_tap_mode
507	@abstract Mode for tapping. BPF_MODE_DISABLED/BPF_MODE_INPUT_OUTPUT etc.
508*/
509typedef u_int32_t bpf_tap_mode;
510#endif /* !BPF_TAP_MODE_T */
511
512/*!
513	@typedef bpf_send_func
514	@discussion bpf_send_func is called when a bpf file descriptor is
515		used to send a raw packet on the interface. The mbuf and data
516		link type are specified. The callback is responsible for
517		releasing the mbuf whether or not it returns an error.
518	@param interface The interface the packet is being sent on.
519	@param dlt The data link type the bpf device is attached to.
520	@param packet The packet to be sent.
521 */
522typedef errno_t (*bpf_send_func)(ifnet_t interface, u_int32_t data_link_type,
523								 mbuf_t packet);
524
525/*!
526	@typedef bpf_tap_func
527	@discussion bpf_tap_func is called when the tap state of the
528		interface changes. This happens when a bpf device attaches to an
529		interface or detaches from an interface. The tap mode will join
530		together (bit or) the modes of all bpf devices using that
531		interface for that dlt. If you return an error from this
532		function, the bpf device attach attempt that triggered the tap
533		will fail. If this function was called bacuse the tap state was
534		decreasing (tap in or out is stopping), the error will be
535		ignored.
536	@param interface The interface being tapped.
537	@param dlt The data link type being tapped.
538	@param direction The direction of the tap.
539 */
540typedef errno_t (*bpf_tap_func)(ifnet_t interface, u_int32_t data_link_type,
541								bpf_tap_mode direction);
542
543/*!
544	@function bpfattach
545	@discussion Registers an interface with BPF. This allows bpf devices
546		to attach to your interface to capture packets. Your interface
547		will be unregistered automatically when your interface is
548		detached.
549	@param interface The interface to register with BPF.
550	@param data_link_type The data link type of the interface. See the
551		DLT_* defines in bpf.h.
552	@param header_length The length, in bytes, of the data link header.
553 */
554extern void  bpfattach(ifnet_t interface, u_int data_link_type,
555    u_int header_length);
556
557/*!
558	@function bpf_attach
559	@discussion Registers an interface with BPF. This allows bpf devices
560		to attach to your interface to capture and transmit packets.
561		Your interface will be unregistered automatically when your
562		interface is detached. You may register multiple times with
563		different data link types. An 802.11 interface would use this to
564		allow clients to pick whether they want just an ethernet style
565		frame or the 802.11 wireless headers as well. The first dlt you
566		register will be considered the default. Any bpf device attaches
567		that do not specify a data link type will use the default.
568	@param interface The interface to register with BPF.
569	@param data_link_type The data link type of the interface. See the
570		DLT_* defines in bpf.h.
571	@param header_length The length, in bytes, of the data link header.
572 */
573extern errno_t  bpf_attach(ifnet_t interface, u_int32_t data_link_type,
574    u_int32_t header_length, bpf_send_func send, bpf_tap_func tap);
575
576/*!
577	@function bpf_tap_in
578	@discussion Call this function when your interface receives a
579		packet. This function will check if any bpf devices need a
580		a copy of the packet.
581	@param interface The interface the packet was received on.
582	@param dlt The data link type of the packet.
583	@param packet The packet received.
584	@param header An optional pointer to a header that will be prepended.
585	@param headerlen If the header was specified, the length of the header.
586 */
587extern void bpf_tap_in(ifnet_t interface, u_int32_t dlt, mbuf_t packet,
588    void *header, size_t header_len);
589
590/*!
591	@function bpf_tap_out
592	@discussion Call this function when your interface trasmits a
593		packet. This function will check if any bpf devices need a
594		a copy of the packet.
595	@param interface The interface the packet was or will be transmitted on.
596	@param dlt The data link type of the packet.
597	@param packet The packet received.
598	@param header An optional pointer to a header that will be prepended.
599	@param headerlen If the header was specified, the length of the header.
600 */
601extern void bpf_tap_out(ifnet_t interface, u_int32_t dlt, mbuf_t packet,
602    void *header, size_t header_len);
603
604#endif /* KERNEL */
605
606/*
607 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
608 */
609#define BPF_MEMWORDS 16
610
611#endif /* _NET_BPF_H_ */
612