xref: /freebsd/sys/net/bpfdesc.h (revision 2357939bc239bd5334a169b62313806178dd8f30)
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  *      @(#)bpfdesc.h	8.1 (Berkeley) 6/10/93
35  *
36  * $FreeBSD$
37  */
38 
39 #ifndef _NET_BPFDESC_H_
40 #define _NET_BPFDESC_H_
41 
42 #include <sys/callout.h>
43 #include <sys/selinfo.h>
44 
45 /*
46  * Descriptor associated with each open bpf file.
47  */
48 struct bpf_d {
49 	struct bpf_d	*bd_next;	/* Linked list of descriptors */
50 	/*
51 	 * Buffer slots: two mbuf clusters buffer the incoming packets.
52 	 *   The model has three slots.  Sbuf is always occupied.
53 	 *   sbuf (store) - Receive interrupt puts packets here.
54 	 *   hbuf (hold) - When sbuf is full, put cluster here and
55 	 *                 wakeup read (replace sbuf with fbuf).
56 	 *   fbuf (free) - When read is done, put cluster here.
57 	 * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
58 	 */
59 	caddr_t		bd_sbuf;	/* store slot */
60 	caddr_t		bd_hbuf;	/* hold slot */
61 	caddr_t		bd_fbuf;	/* free slot */
62 	int 		bd_slen;	/* current length of store buffer */
63 	int 		bd_hlen;	/* current length of hold buffer */
64 
65 	int		bd_bufsize;	/* absolute length of buffers */
66 
67 	struct bpf_if *	bd_bif;		/* interface descriptor */
68 	u_long		bd_rtout;	/* Read timeout in 'ticks' */
69 	struct bpf_insn *bd_filter; 	/* filter code */
70 	u_long		bd_rcount;	/* number of packets received */
71 	u_long		bd_dcount;	/* number of packets dropped */
72 
73 	u_char		bd_promisc;	/* true if listening promiscuously */
74 	u_char		bd_state;	/* idle, waiting, or timed out */
75 	u_char		bd_immediate;	/* true to return on packet arrival */
76 	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
77 	int		bd_seesent;	/* true if bpf should see sent packets */
78 	int		bd_async;	/* non-zero if packet reception should generate signal */
79 	int		bd_sig;		/* signal to send upon packet reception */
80 	struct sigio *	bd_sigio;	/* information for async I/O */
81 #if BSD < 199103
82 	u_char		bd_selcoll;	/* true if selects collide */
83 	int		bd_timedout;
84 	struct thread *	bd_selthread;	/* process that last selected us */
85 #else
86 	u_char		bd_pad;		/* explicit alignment */
87 	struct selinfo	bd_sel;		/* bsd select info */
88 #endif
89 	struct mtx	bd_mtx;		/* mutex for this descriptor */
90 	struct callout	bd_callout;	/* for BPF timeouts with select */
91 	struct label	*bd_label;	/* MAC label for descriptor */
92 };
93 
94 /* Values for bd_state */
95 #define BPF_IDLE	0		/* no select in progress */
96 #define BPF_WAITING	1		/* waiting for read timeout in select */
97 #define BPF_TIMED_OUT	2		/* read timeout has expired in select */
98 
99 #define BPFD_LOCK(bd)		mtx_lock(&(bd)->bd_mtx)
100 #define BPFD_UNLOCK(bd)		mtx_unlock(&(bd)->bd_mtx)
101 #define BPFD_LOCK_ASSERT(bd)	do {				\
102 	mtx_assert(&(bd)->bd_mtx, MA_OWNED);			\
103 	NET_ASSERT_GIANT();					\
104 } while (0)
105 
106 /* Test whether a BPF is ready for read(). */
107 #define	bpf_ready(bd)						 \
108 	((bd)->bd_hlen != 0 ||					 \
109 	 (((bd)->bd_immediate || (bd)->bd_state == BPF_TIMED_OUT) && \
110 	  (bd)->bd_slen != 0))
111 
112 /*
113  * Descriptor associated with each attached hardware interface.
114  */
115 struct bpf_if {
116 	struct bpf_if *bif_next;	/* list of all interfaces */
117 	struct bpf_d *bif_dlist;	/* descriptor list */
118 	struct bpf_if **bif_driverp;	/* pointer into softc */
119 	u_int bif_dlt;			/* link layer type */
120 	u_int bif_hdrlen;		/* length of header (with padding) */
121 	struct ifnet *bif_ifp;		/* corresponding interface */
122 	struct mtx	bif_mtx;	/* mutex for interface */
123 };
124 
125 #define BPFIF_LOCK(bif)		mtx_lock(&(bif)->bif_mtx)
126 #define BPFIF_UNLOCK(bif)	mtx_unlock(&(bif)->bif_mtx)
127 
128 #endif
129