xref: /csrg-svn/sys/net/bpfdesc.h (revision 51426)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * 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	7.1 (Berkeley) 5/7/91
39  *
40  * @(#) $Header: bpfdesc.h,v 1.9 91/10/27 21:22:38 mccanne Exp $ (LBL)
41  */
42 
43 /*
44  * Descriptor associated with each open bpf file.
45  */
46 struct bpf_d {
47 	struct bpf_d	*bd_next;	/* Linked list of descriptors */
48 	/*
49 	 * Buffer slots: two mbuf clusters buffer the incoming packets.
50 	 *   The model has three slots.  Sbuf is always occupied.
51 	 *   sbuf (store) - Receive interrupt puts packets here.
52 	 *   hbuf (hold) - When sbuf is full, put cluster here and
53 	 *                 wakeup read (replace sbuf with fbuf).
54 	 *   fbuf (free) - When read is done, put cluster here.
55 	 * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
56 	 */
57 	caddr_t		bd_sbuf;	/* store slot */
58 	caddr_t		bd_hbuf;	/* hold slot */
59 	caddr_t		bd_fbuf;	/* free slot */
60 	int 		bd_slen;	/* current length of store buffer */
61 	int 		bd_hlen;	/* current length of hold buffer */
62 
63 	int		bd_bufsize;	/* absolute length of buffers */
64 
65 	struct bpf_if *	bd_bif;		/* interface descriptor */
66 	u_long		bd_rtout;	/* Read timeout in 'ticks' */
67 	struct bpf_insn *bd_filter; 	/* filter code */
68 	u_long		bd_rcount;	/* number of packets received */
69 	u_long		bd_dcount;	/* number of packets dropped */
70 	struct proc *	bd_selproc;	/* process that last selected us */
71 
72 	u_char		bd_promisc;	/* true if listening promiscuously */
73 	u_char		bd_state;	/* idle, waiting, or timed out */
74 	u_char		bd_selcoll;	/* true if selects collide */
75 	u_char		bd_immediate;	/* true to return on packet arrival */
76 #if BSD < 199103
77 	int		bd_timedout;
78 #endif
79 };
80 
81 /*
82  * Descriptor associated with each attached hardware interface.
83  */
84 struct bpf_if {
85 	struct bpf_if *bif_next;	/* list of all interfaces */
86 	struct bpf_d *bif_dlist;	/* descriptor list */
87 	struct bpf_if **bif_driverp;	/* pointer into softc */
88 	u_int bif_dlt;			/* link layer type */
89 	u_int bif_hdrlen;		/* length of header (with padding) */
90 	struct ifnet *bif_ifp;		/* correspoding interface */
91 };
92