xref: /freebsd-10.3-release/sys/net/bpfdesc.h

/*
 * Copyright (c) 1990, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from the Stanford/CMU enet packet filter,
 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
 * Berkeley Laboratory.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)bpfdesc.h	8.1 (Berkeley) 6/10/93
 *
 * $FreeBSD: head/sys/net/bpfdesc.h 127541 2004-03-29 00:33:39Z rwatson $
 */

#ifndef _NET_BPFDESC_H_
#define _NET_BPFDESC_H_

#include <sys/callout.h>
#include <sys/selinfo.h>

/*
 * Descriptor associated with each open bpf file.
 */
struct bpf_d {
	struct bpf_d	*bd_next;	/* Linked list of descriptors */
	/*
	 * Buffer slots: two mbuf clusters buffer the incoming packets.
	 *   The model has three slots.  Sbuf is always occupied.
	 *   sbuf (store) - Receive interrupt puts packets here.
	 *   hbuf (hold) - When sbuf is full, put cluster here and
	 *                 wakeup read (replace sbuf with fbuf).
	 *   fbuf (free) - When read is done, put cluster here.
	 * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
	 */
	caddr_t		bd_sbuf;	/* store slot */
	caddr_t		bd_hbuf;	/* hold slot */
	caddr_t		bd_fbuf;	/* free slot */
	int 		bd_slen;	/* current length of store buffer */
	int 		bd_hlen;	/* current length of hold buffer */

	int		bd_bufsize;	/* absolute length of buffers */

	struct bpf_if *	bd_bif;		/* interface descriptor */
	u_long		bd_rtout;	/* Read timeout in 'ticks' */
	struct bpf_insn *bd_filter; 	/* filter code */
	u_long		bd_rcount;	/* number of packets received */
	u_long		bd_dcount;	/* number of packets dropped */

	u_char		bd_promisc;	/* true if listening promiscuously */
	u_char		bd_state;	/* idle, waiting, or timed out */
	u_char		bd_immediate;	/* true to return on packet arrival */
	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
	int		bd_seesent;	/* true if bpf should see sent packets */
	int		bd_async;	/* non-zero if packet reception should generate signal */
	int		bd_sig;		/* signal to send upon packet reception */
	struct sigio *	bd_sigio;	/* information for async I/O */
#if BSD < 199103
	u_char		bd_selcoll;	/* true if selects collide */
	int		bd_timedout;
	struct thread *	bd_selthread;	/* process that last selected us */
#else
	u_char		bd_pad;		/* explicit alignment */
	struct selinfo	bd_sel;		/* bsd select info */
#endif
	struct mtx	bd_mtx;		/* mutex for this descriptor */
	struct callout	bd_callout;	/* for BPF timeouts with select */
	struct label	*bd_label;	/* MAC label for descriptor */
};

/* Values for bd_state */
#define BPF_IDLE	0		/* no select in progress */
#define BPF_WAITING	1		/* waiting for read timeout in select */
#define BPF_TIMED_OUT	2		/* read timeout has expired in select */

#define BPFD_LOCK(bd)		mtx_lock(&(bd)->bd_mtx)
#define BPFD_UNLOCK(bd)		mtx_unlock(&(bd)->bd_mtx)
#define BPFD_LOCK_ASSERT(bd)	do {				\
	mtx_assert(&(bd)->bd_mtx, MA_OWNED);			\
	NET_ASSERT_GIANT();					\
} while (0)

/* Test whether a BPF is ready for read(). */
#define	bpf_ready(bd)						 \
	((bd)->bd_hlen != 0 ||					 \
	 (((bd)->bd_immediate || (bd)->bd_state == BPF_TIMED_OUT) && \
	  (bd)->bd_slen != 0))

/*
 * Descriptor associated with each attached hardware interface.
 */
struct bpf_if {
	struct bpf_if *bif_next;	/* list of all interfaces */
	struct bpf_d *bif_dlist;	/* descriptor list */
	struct bpf_if **bif_driverp;	/* pointer into softc */
	u_int bif_dlt;			/* link layer type */
	u_int bif_hdrlen;		/* length of header (with padding) */
	struct ifnet *bif_ifp;		/* corresponding interface */
	struct mtx	bif_mtx;	/* mutex for interface */
};

#define BPFIF_LOCK(bif)		mtx_lock(&(bif)->bif_mtx)
#define BPFIF_UNLOCK(bif)	mtx_unlock(&(bif)->bif_mtx)

#endif