bpfdesc.h

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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. 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.
 */

#ifndef _NET_BPFDESC_H_
#define _NET_BPFDESC_H_

#include <sys/callout.h>
#include <sys/selinfo.h>
#include <sys/ck.h>
#include <sys/conf.h>
#include <sys/counter.h>
#include <sys/epoch.h>
#include <net/if.h>

/*
 * Descriptor associated with each open bpf file.
 */
struct zbuf;
struct bpf_d {
	CK_LIST_ENTRY(bpf_d) bd_next;	/* Linked list of descriptors */
	/*
	 * Buffer slots: two memory buffers store 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 buffer here and
	 *                 wakeup read (replace sbuf with fbuf).
	 *   fbuf (free) - When read is done, put buffer 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_hbuf_in_use;	/* don't rotate buffers */
	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_rfilter; 	/* read filter code */
	struct bpf_insn *bd_wfilter;	/* write filter code */
	void		*bd_bfilter;	/* binary filter code */
	counter_u64_t	bd_rcount;	/* number of packets received */
	counter_u64_t	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 */
	u_char		bd_writer;	/* non-zero if d is writer-only */
	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
	int		bd_direction;	/* select packet direction */
	int		bd_tstamp;	/* select time stamping function */
	int		bd_feedback;	/* true to feed back sent packets */
	int		bd_async;	/* non-zero if packet reception should generate signal */
	int		bd_sig;		/* signal to send upon packet reception */
	int		bd_pcp;		/* VLAN pcp tag */
	struct sigio *	bd_sigio;	/* information for async I/O */
	struct selinfo	bd_sel;		/* bsd select info */
	struct mtx	bd_lock;	/* per-descriptor lock */
	struct callout	bd_callout;	/* for BPF timeouts with select */
	struct label	*bd_label;	/* MAC label for descriptor */
	counter_u64_t	bd_fcount;	/* number of packets which matched filter */
	pid_t		bd_pid;		/* PID which created descriptor */
	int		bd_locked;	/* true if descriptor is locked */
	u_int		bd_bufmode;	/* Current buffer mode. */
	counter_u64_t	bd_wcount;	/* number of packets written */
	counter_u64_t	bd_wfcount;	/* number of packets that matched write filter */
	counter_u64_t	bd_wdcount;	/* number of packets dropped during a write */
	counter_u64_t	bd_zcopy;	/* number of zero copy operations */
	u_char		bd_compat32;	/* 32-bit stream on LP64 system */

	volatile u_int	bd_refcnt;
	struct epoch_context epoch_ctx;
};

/* 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_lock)
#define BPFD_UNLOCK(bd)		mtx_unlock(&(bd)->bd_lock)
#define BPFD_LOCK_ASSERT(bd)	mtx_assert(&(bd)->bd_lock, MA_OWNED)

#define BPF_PID_REFRESH(bd, td)	(bd)->bd_pid = (td)->td_proc->p_pid
#define BPF_PID_REFRESH_CUR(bd)	(bd)->bd_pid = curthread->td_proc->p_pid

/*
 * External representation of the bpf descriptor
 */
struct xbpf_d {
	u_int		bd_structsize;	/* Size of this structure. */
	u_char		bd_promisc;
	u_char		bd_immediate;
	u_char		__bd_pad[6];
	int		bd_hdrcmplt;
	int		bd_direction;
	int		bd_feedback;
	int		bd_async;
	u_int64_t	bd_rcount;
	u_int64_t	bd_dcount;
	u_int64_t	bd_fcount;
	int		bd_sig;
	int		bd_slen;
	int		bd_hlen;
	int		bd_bufsize;
	pid_t		bd_pid;
	char		bd_ifname[IFNAMSIZ];
	int		bd_locked;
	u_int64_t	bd_wcount;
	u_int64_t	bd_wfcount;
	u_int64_t	bd_wdcount;
	u_int64_t	bd_zcopy;
	int		bd_bufmode;
	/*
	 * Allocate 4 64 bit unsigned integers for future expansion so we do
	 * not have to worry about breaking the ABI.
	 */
	u_int64_t	bd_spare[4];
};

#define BPFIF_FLAG_DYING	1	/* Reject new bpf consumers */

#endif