bpfdesc.h revision 127541 
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *      @(#)bpfdesc.h	8.1 (Berkeley) 6/10/93
39 *
40 * $FreeBSD: head/sys/net/bpfdesc.h 127541 2004-03-29 00:33:39Z rwatson $
41 */
42
43#ifndef _NET_BPFDESC_H_
44#define _NET_BPFDESC_H_
45
46#include <sys/callout.h>
47#include <sys/selinfo.h>
48
49/*
50 * Descriptor associated with each open bpf file.
51 */
52struct bpf_d {
53	struct bpf_d	*bd_next;	/* Linked list of descriptors */
54	/*
55	 * Buffer slots: two mbuf clusters buffer the incoming packets.
56	 *   The model has three slots.  Sbuf is always occupied.
57	 *   sbuf (store) - Receive interrupt puts packets here.
58	 *   hbuf (hold) - When sbuf is full, put cluster here and
59	 *                 wakeup read (replace sbuf with fbuf).
60	 *   fbuf (free) - When read is done, put cluster here.
61	 * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
62	 */
63	caddr_t		bd_sbuf;	/* store slot */
64	caddr_t		bd_hbuf;	/* hold slot */
65	caddr_t		bd_fbuf;	/* free slot */
66	int 		bd_slen;	/* current length of store buffer */
67	int 		bd_hlen;	/* current length of hold buffer */
68
69	int		bd_bufsize;	/* absolute length of buffers */
70
71	struct bpf_if *	bd_bif;		/* interface descriptor */
72	u_long		bd_rtout;	/* Read timeout in 'ticks' */
73	struct bpf_insn *bd_filter; 	/* filter code */
74	u_long		bd_rcount;	/* number of packets received */
75	u_long		bd_dcount;	/* number of packets dropped */
76
77	u_char		bd_promisc;	/* true if listening promiscuously */
78	u_char		bd_state;	/* idle, waiting, or timed out */
79	u_char		bd_immediate;	/* true to return on packet arrival */
80	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
81	int		bd_seesent;	/* true if bpf should see sent packets */
82	int		bd_async;	/* non-zero if packet reception should generate signal */
83	int		bd_sig;		/* signal to send upon packet reception */
84	struct sigio *	bd_sigio;	/* information for async I/O */
85#if BSD < 199103
86	u_char		bd_selcoll;	/* true if selects collide */
87	int		bd_timedout;
88	struct thread *	bd_selthread;	/* process that last selected us */
89#else
90	u_char		bd_pad;		/* explicit alignment */
91	struct selinfo	bd_sel;		/* bsd select info */
92#endif
93	struct mtx	bd_mtx;		/* mutex for this descriptor */
94	struct callout	bd_callout;	/* for BPF timeouts with select */
95	struct label	*bd_label;	/* MAC label for descriptor */
96};
97
98/* Values for bd_state */
99#define BPF_IDLE	0		/* no select in progress */
100#define BPF_WAITING	1		/* waiting for read timeout in select */
101#define BPF_TIMED_OUT	2		/* read timeout has expired in select */
102
103#define BPFD_LOCK(bd)		mtx_lock(&(bd)->bd_mtx)
104#define BPFD_UNLOCK(bd)		mtx_unlock(&(bd)->bd_mtx)
105#define BPFD_LOCK_ASSERT(bd)	do {				\
106	mtx_assert(&(bd)->bd_mtx, MA_OWNED);			\
107	NET_ASSERT_GIANT();					\
108} while (0)
109
110/* Test whether a BPF is ready for read(). */
111#define	bpf_ready(bd)						 \
112	((bd)->bd_hlen != 0 ||					 \
113	 (((bd)->bd_immediate || (bd)->bd_state == BPF_TIMED_OUT) && \
114	  (bd)->bd_slen != 0))
115
116/*
117 * Descriptor associated with each attached hardware interface.
118 */
119struct bpf_if {
120	struct bpf_if *bif_next;	/* list of all interfaces */
121	struct bpf_d *bif_dlist;	/* descriptor list */
122	struct bpf_if **bif_driverp;	/* pointer into softc */
123	u_int bif_dlt;			/* link layer type */
124	u_int bif_hdrlen;		/* length of header (with padding) */
125	struct ifnet *bif_ifp;		/* corresponding interface */
126	struct mtx	bif_mtx;	/* mutex for interface */
127};
128
129#define BPFIF_LOCK(bif)		mtx_lock(&(bif)->bif_mtx)
130#define BPFIF_UNLOCK(bif)	mtx_unlock(&(bif)->bif_mtx)
131
132#endif
133