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File: [cvs.NetBSD.org] / src / sys / sys / socketvar.h (download)

Revision 1.164, Sat Oct 23 01:28:33 2021 UTC (2 months, 4 weeks ago) by thorpej
Branch: MAIN
CVS Tags: HEAD
Changes since 1.163: +12 -1 lines

Add support for the EVFILT_EMPTY filter, which is activated when the
write buffer associated with the file descriptor is empty.  This is
currently implemented only for sockets, and is intended primarily to
provide visibility to applications that all previously written data
has been acknowledged by the TCP layer on the receiver.  Compatible
with the same filter in FreeBSD.

/*	$NetBSD: socketvar.h,v 1.164 2021/10/23 01:28:33 thorpej Exp $	*/

/*-
 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*-
 * Copyright (c) 1982, 1986, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 *
 *	@(#)socketvar.h	8.3 (Berkeley) 2/19/95
 */

#ifndef _SYS_SOCKETVAR_H_
#define	_SYS_SOCKETVAR_H_

#include <sys/select.h>
#include <sys/selinfo.h>		/* for struct selinfo */
#include <sys/queue.h>
#include <sys/mutex.h>
#include <sys/condvar.h>

#if !defined(_KERNEL)
struct uio;
struct lwp;
struct uidinfo;
#else
#include <sys/uidinfo.h>
#endif

TAILQ_HEAD(soqhead, socket);

/*
 * Variables for socket buffering.
 */
struct sockbuf {
	struct selinfo sb_sel;		/* process selecting read/write */
	struct mowner *sb_mowner;	/* who owns data for this sockbuf */
	struct socket *sb_so;		/* back pointer to socket */
	kcondvar_t sb_cv;		/* notifier */
	/* When re-zeroing this struct, we zero from sb_startzero to the end */
#define	sb_startzero	sb_cc
	u_long	sb_cc;			/* actual chars in buffer */
	u_long	sb_hiwat;		/* max actual char count */
	u_long	sb_mbcnt;		/* chars of mbufs used */
	u_long	sb_mbmax;		/* max chars of mbufs to use */
	u_long	sb_lowat;		/* low water mark */
	struct mbuf *sb_mb;		/* the mbuf chain */
	struct mbuf *sb_mbtail;		/* the last mbuf in the chain */
	struct mbuf *sb_lastrecord;	/* first mbuf of last record in
					   socket buffer */
	int	sb_flags;		/* flags, see below */
	int	sb_timeo;		/* timeout for read/write */
	u_long	sb_overflowed;		/* # of drops due to full buffer */
};

#ifndef SB_MAX
#define	SB_MAX		(256*1024)	/* default for max chars in sockbuf */
#endif

#define	SB_LOCK		0x01		/* lock on data queue */
#define	SB_NOTIFY	0x04		/* someone is waiting for data/space */
#define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
#define	SB_UPCALL	0x20		/* someone wants an upcall */
#define	SB_NOINTR	0x40		/* operations not interruptible */
#define	SB_KNOTE	0x100		/* kernel note attached */
#define	SB_AUTOSIZE	0x800		/* automatically size socket buffer */

/*
 * Kernel structure per socket.
 * Contains send and receive buffer queues,
 * handle on protocol and pointer to protocol
 * private data and error information.
 */
struct so_accf {
	struct accept_filter	*so_accept_filter;
	void	*so_accept_filter_arg;	/* saved filter args */
	char	*so_accept_filter_str;	/* saved user args */
};

struct sockaddr;

struct socket {
	kmutex_t * volatile so_lock;	/* pointer to lock on structure */
	kcondvar_t	so_cv;		/* notifier */
	short		so_type;	/* generic type, see socket.h */
	short		so_options;	/* from socket call, see socket.h */
	u_short		so_linger;	/* time to linger while closing */
	short		so_state;	/* internal state flags SS_*, below */
	int		so_unused;	/* used to be so_nbio */
	void		*so_pcb;	/* protocol control block */
	const struct protosw *so_proto;	/* protocol handle */
/*
 * Variables for connection queueing.
 * Socket where accepts occur is so_head in all subsidiary sockets.
 * If so_head is 0, socket is not related to an accept.
 * For head socket so_q0 queues partially completed connections,
 * while so_q is a queue of connections ready to be accepted.
 * If a connection is aborted and it has so_head set, then
 * it has to be pulled out of either so_q0 or so_q.
 * We allow connections to queue up based on current queue lengths
 * and limit on number of queued connections for this socket.
 */
	struct socket	*so_head;	/* back pointer to accept socket */
	struct soqhead	*so_onq;	/* queue (q or q0) that we're on */
	struct soqhead	so_q0;		/* queue of partial connections */
	struct soqhead	so_q;		/* queue of incoming connections */
	TAILQ_ENTRY(socket) so_qe;	/* our queue entry (q or q0) */
	short		so_q0len;	/* partials on so_q0 */
	short		so_qlen;	/* number of connections on so_q */
	short		so_qlimit;	/* max number queued connections */
	short		so_timeo;	/* connection timeout */
	u_short		so_error;	/* error affecting connection */
	u_short		so_rerror;	/* error affecting receiving */
	u_short		so_aborting;	/* references from soabort() */
	pid_t		so_pgid;	/* pgid for signals */
	u_long		so_oobmark;	/* chars to oob mark */
	struct sockbuf	so_snd;		/* send buffer */
	struct sockbuf	so_rcv;		/* receive buffer */

	void		*so_internal;	/* Space for svr4 stream data */
	void		(*so_upcall) (struct socket *, void *, int, int);
	void *		so_upcallarg;	/* Arg for above */
	int		(*so_send) (struct socket *, struct sockaddr *,
					struct uio *, struct mbuf *,
					struct mbuf *, int, struct lwp *);
	int		(*so_receive) (struct socket *,
					struct mbuf **,
					struct uio *, struct mbuf **,
					struct mbuf **, int *);
	struct mowner	*so_mowner;	/* who owns mbufs for this socket */
	struct uidinfo	*so_uidinfo;	/* who opened the socket */
	gid_t		so_egid;	/* creator effective gid */
	pid_t		so_cpid;	/* creator pid */
	struct so_accf	*so_accf;
	kauth_cred_t	so_cred;	/* socket credentials */
};

/*
 * Socket state bits.
 */
#define	SS_NOFDREF		0x001	/* no file table ref any more */
#define	SS_ISCONNECTED		0x002	/* socket connected to a peer */
#define	SS_ISCONNECTING		0x004	/* in process of connecting to peer */
#define	SS_ISDISCONNECTING	0x008	/* in process of disconnecting */
#define	SS_CANTSENDMORE		0x010	/* can't send more data to peer */
#define	SS_CANTRCVMORE		0x020	/* can't receive more data from peer */
#define	SS_RCVATMARK		0x040	/* at mark on input */
#define	SS_ISABORTING		0x080	/* aborting fd references - close() */
#define	SS_RESTARTSYS		0x100	/* restart blocked system calls */
#define	SS_POLLRDBAND		0x200	/* poll should return POLLRDBAND */
#define	SS_MORETOCOME		0x400	/*
					 * hint from sosend to lower layer;
					 * more data coming
					 */
#define	SS_ISDISCONNECTED	0x800	/* socket disconnected from peer */
#define	SS_ISAPIPE 		0x1000	/* socket is implementing a pipe */
#define	SS_NBIO			0x2000	/* socket is in non blocking I/O */

#ifdef _KERNEL

struct accept_filter {
	char	accf_name[16];
	void	(*accf_callback)
		(struct socket *, void *, int, int);
	void *	(*accf_create)
		(struct socket *, char *);
	void	(*accf_destroy)
		(struct socket *);
	LIST_ENTRY(accept_filter) accf_next;
	u_int	accf_refcnt;
};

struct sockopt {
	int		sopt_level;		/* option level */
	int		sopt_name;		/* option name */
	size_t		sopt_size;		/* data length */
	size_t		sopt_retsize;		/* returned data length */
	void *		sopt_data;		/* data pointer */
	uint8_t		sopt_buf[sizeof(int)];	/* internal storage */
};

#define	SB_EMPTY_FIXUP(sb)						\
do {									\
	KASSERT(solocked((sb)->sb_so));					\
	if ((sb)->sb_mb == NULL) {					\
		(sb)->sb_mbtail = NULL;					\
		(sb)->sb_lastrecord = NULL;				\
	}								\
} while (/*CONSTCOND*/0)

extern u_long		sb_max;
extern int		somaxkva;
extern int		sock_loan_thresh;
extern kmutex_t		*softnet_lock;

struct mbuf;
struct lwp;
struct msghdr;
struct stat;
struct knote;
struct sockaddr_big;
enum uio_seg;

/* 0x400 is SO_OTIMESTAMP */
#define SOOPT_TIMESTAMP(o)     ((o) & (SO_TIMESTAMP | 0x400))

/*
 * File operations on sockets.
 */
int	soo_read(file_t *, off_t *, struct uio *, kauth_cred_t, int);
int	soo_write(file_t *, off_t *, struct uio *, kauth_cred_t, int);
int	soo_fcntl(file_t *, u_int cmd, void *);
int	soo_ioctl(file_t *, u_long cmd, void *);
int	soo_poll(file_t *, int);
int	soo_kqfilter(file_t *, struct knote *);
int 	soo_close(file_t *);
int	soo_stat(file_t *, struct stat *);
void	soo_restart(file_t *);
void	sbappend(struct sockbuf *, struct mbuf *);
void	sbappendstream(struct sockbuf *, struct mbuf *);
int	sbappendaddr(struct sockbuf *, const struct sockaddr *, struct mbuf *,
	    struct mbuf *);
int	sbappendaddrchain(struct sockbuf *, const struct sockaddr *,
	     struct mbuf *, int);
int	sbappendcontrol(struct sockbuf *, struct mbuf *, struct mbuf *);
void	sbappendrecord(struct sockbuf *, struct mbuf *);
void	sbcheck(struct sockbuf *);
void	sbcompress(struct sockbuf *, struct mbuf *, struct mbuf *);
struct mbuf *
	sbcreatecontrol(void *, int, int, int);
struct mbuf *
	sbcreatecontrol1(void **, int, int, int, int);
struct mbuf **
	sbsavetimestamp(int, struct mbuf **);
void	sbdrop(struct sockbuf *, int);
void	sbdroprecord(struct sockbuf *);
void	sbflush(struct sockbuf *);
void	sbinsertoob(struct sockbuf *, struct mbuf *);
void	sbrelease(struct sockbuf *, struct socket *);
int	sbreserve(struct sockbuf *, u_long, struct socket *);
int	sbwait(struct sockbuf *);
int	sb_max_set(u_long);
void	soinit(void);
void	soinit1(void);
void	soinit2(void);
int	soabort(struct socket *);
int	soaccept(struct socket *, struct sockaddr *);
int	sofamily(const struct socket *);
int	sobind(struct socket *, struct sockaddr *, struct lwp *);
void	socantrcvmore(struct socket *);
void	socantsendmore(struct socket *);
void	soroverflow(struct socket *);
int	soclose(struct socket *);
int	soconnect(struct socket *, struct sockaddr *, struct lwp *);
int	soconnect2(struct socket *, struct socket *);
int	socreate(int, struct socket **, int, int, struct lwp *,
		 struct socket *);
int	fsocreate(int, struct socket **, int, int, int *);
int	sodisconnect(struct socket *);
void	sofree(struct socket *);
int	sogetopt(struct socket *, struct sockopt *);
void	sohasoutofband(struct socket *);
void	soisconnected(struct socket *);
void	soisconnecting(struct socket *);
void	soisdisconnected(struct socket *);
void	soisdisconnecting(struct socket *);
int	solisten(struct socket *, int, struct lwp *);
struct socket *
	sonewconn(struct socket *, bool);
void	soqinsque(struct socket *, struct socket *, int);
bool	soqremque(struct socket *, int);
int	soreceive(struct socket *, struct mbuf **, struct uio *,
	    struct mbuf **, struct mbuf **, int *);
int	soreserve(struct socket *, u_long, u_long);
void	sorflush(struct socket *);
int	sosend(struct socket *, struct sockaddr *, struct uio *,
	    struct mbuf *, struct mbuf *, int, struct lwp *);
int	sosetopt(struct socket *, struct sockopt *);
int	so_setsockopt(struct lwp *, struct socket *, int, int, const void *, size_t);
int	soshutdown(struct socket *, int);
void	sorestart(struct socket *);
void	sowakeup(struct socket *, struct sockbuf *, int);
int	sockargs(struct mbuf **, const void *, size_t, enum uio_seg, int);
int	sopoll(struct socket *, int);
struct	socket *soget(bool);
void	soput(struct socket *);
bool	solocked(const struct socket *);
bool	solocked2(const struct socket *, const struct socket *);
int	sblock(struct sockbuf *, int);
void	sbunlock(struct sockbuf *);
int	sowait(struct socket *, bool, int);
void	solockretry(struct socket *, kmutex_t *);
void	sosetlock(struct socket *);
void	solockreset(struct socket *, kmutex_t *);

void	sockopt_init(struct sockopt *, int, int, size_t);
void	sockopt_destroy(struct sockopt *);
int	sockopt_set(struct sockopt *, const void *, size_t);
int	sockopt_setint(struct sockopt *, int);
int	sockopt_get(const struct sockopt *, void *, size_t);
int	sockopt_getint(const struct sockopt *, int *);
int	sockopt_setmbuf(struct sockopt *, struct mbuf *);
struct mbuf *sockopt_getmbuf(const struct sockopt *);

int	copyout_sockname(struct sockaddr *, unsigned int *, int, struct mbuf *);
int	copyout_sockname_sb(struct sockaddr *, unsigned int *,
    int , struct sockaddr_big *);
int	copyout_msg_control(struct lwp *, struct msghdr *, struct mbuf *);
void	free_control_mbuf(struct lwp *, struct mbuf *, struct mbuf *);

int	do_sys_getpeername(int, struct sockaddr *);
int	do_sys_getsockname(int, struct sockaddr *);

int	do_sys_sendmsg(struct lwp *, int, struct msghdr *, int, register_t *);
int	do_sys_sendmsg_so(struct lwp *, int, struct socket *, file_t *,
	    struct msghdr *, int, register_t *);

int	do_sys_recvmsg(struct lwp *, int, struct msghdr *,
	    struct mbuf **, struct mbuf **, register_t *);
int	do_sys_recvmsg_so(struct lwp *, int, struct socket *,
	    struct msghdr *mp, struct mbuf **, struct mbuf **, register_t *);

int	do_sys_bind(struct lwp *, int, struct sockaddr *);
int	do_sys_connect(struct lwp *, int, struct sockaddr *);
int	do_sys_accept(struct lwp *, int, struct sockaddr *, register_t *,
	    const sigset_t *, int, int);

int	do_sys_peeloff(struct socket *, void *);
/*
 * Inline functions for sockets and socket buffering.
 */

#include <sys/protosw.h>
#include <sys/mbuf.h>

/*
 * Do we need to notify the other side when I/O is possible?
 */
static __inline int
sb_notify(struct sockbuf *sb)
{

	KASSERT(solocked(sb->sb_so));

	return sb->sb_flags & (SB_NOTIFY | SB_ASYNC | SB_UPCALL | SB_KNOTE);
}

/*
 * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
 * Since the fields are unsigned, detect overflow and return 0.
 */
static __inline u_long
sbspace(const struct sockbuf *sb)
{

	KASSERT(solocked(sb->sb_so));
	if (sb->sb_hiwat <= sb->sb_cc || sb->sb_mbmax <= sb->sb_mbcnt)
		return 0;
	return lmin(sb->sb_hiwat - sb->sb_cc, sb->sb_mbmax - sb->sb_mbcnt);
}

static __inline u_long
sbspace_oob(const struct sockbuf *sb)
{
	u_long hiwat = sb->sb_hiwat;

	if (hiwat < ULONG_MAX - 1024)
		hiwat += 1024;

	KASSERT(solocked(sb->sb_so));

	if (hiwat <= sb->sb_cc || sb->sb_mbmax <= sb->sb_mbcnt)
		return 0;
	return lmin(hiwat - sb->sb_cc, sb->sb_mbmax - sb->sb_mbcnt);
}

/*
 * How much socket buffer space has been used?
 */
static __inline u_long
sbused(const struct sockbuf *sb)
{

	KASSERT(solocked(sb->sb_so));
	return sb->sb_cc;
}

/* do we have to send all at once on a socket? */
static __inline int
sosendallatonce(const struct socket *so)
{

	return so->so_proto->pr_flags & PR_ATOMIC;
}

/* can we read something from so? */
static __inline int
soreadable(const struct socket *so)
{

	KASSERT(solocked(so));

	return so->so_rcv.sb_cc >= so->so_rcv.sb_lowat ||
	    (so->so_state & SS_CANTRCVMORE) != 0 ||
	    so->so_qlen != 0 || so->so_error != 0 || so->so_rerror != 0;
}

/* can we write something to so? */
static __inline int
sowritable(const struct socket *so)
{

	KASSERT(solocked(so));

	return (sbspace(&so->so_snd) >= so->so_snd.sb_lowat &&
	    ((so->so_state & SS_ISCONNECTED) != 0 ||
	    (so->so_proto->pr_flags & PR_CONNREQUIRED) == 0)) ||
	    (so->so_state & SS_CANTSENDMORE) != 0 ||
	    so->so_error != 0;
}

/* adjust counters in sb reflecting allocation of m */
static __inline void
sballoc(struct sockbuf *sb, struct mbuf *m)
{

	KASSERT(solocked(sb->sb_so));

	sb->sb_cc += m->m_len;
	sb->sb_mbcnt += MSIZE;
	if (m->m_flags & M_EXT)
		sb->sb_mbcnt += m->m_ext.ext_size;
}

/* adjust counters in sb reflecting freeing of m */
static __inline void
sbfree(struct sockbuf *sb, struct mbuf *m)
{

	KASSERT(solocked(sb->sb_so));

	sb->sb_cc -= m->m_len;
	sb->sb_mbcnt -= MSIZE;
	if (m->m_flags & M_EXT)
		sb->sb_mbcnt -= m->m_ext.ext_size;
}

static __inline void
sorwakeup(struct socket *so)
{

	KASSERT(solocked(so));

	if (sb_notify(&so->so_rcv))
		sowakeup(so, &so->so_rcv, POLL_IN);
}

static __inline void
sowwakeup(struct socket *so)
{

	KASSERT(solocked(so));

	if (sb_notify(&so->so_snd))
		sowakeup(so, &so->so_snd, POLL_OUT);
}

static __inline void
solock(struct socket *so)
{
	kmutex_t *lock;

	lock = so->so_lock;
	mutex_enter(lock);
	if (__predict_false(lock != so->so_lock))
		solockretry(so, lock);
}
	
static __inline void
sounlock(struct socket *so)
{

	mutex_exit(so->so_lock);
}

#ifdef SOCKBUF_DEBUG
/*
 * SBLASTRECORDCHK: check sb->sb_lastrecord is maintained correctly.
 * SBLASTMBUFCHK: check sb->sb_mbtail is maintained correctly.
 *
 * => panic if the socket buffer is inconsistent.
 * => 'where' is used for a panic message.
 */
void	sblastrecordchk(struct sockbuf *, const char *);
#define	SBLASTRECORDCHK(sb, where)	sblastrecordchk((sb), (where))

void	sblastmbufchk(struct sockbuf *, const char *);
#define	SBLASTMBUFCHK(sb, where)	sblastmbufchk((sb), (where))
#define	SBCHECK(sb)			sbcheck(sb)
#else
#define	SBLASTRECORDCHK(sb, where)	/* nothing */
#define	SBLASTMBUFCHK(sb, where)	/* nothing */
#define	SBCHECK(sb)			/* nothing */
#endif /* SOCKBUF_DEBUG */

/* sosend loan */
vaddr_t	sokvaalloc(vaddr_t, vsize_t, struct socket *);
void	sokvafree(vaddr_t, vsize_t);
void	soloanfree(struct mbuf *, void *, size_t, void *);

/*
 * Values for socket-buffer-append priority argument to sbappendaddrchain().
 * The following flags are reserved for future implementation:
 *
 *  SB_PRIO_NONE:  honour normal socket-buffer limits.
 *
 *  SB_PRIO_ONESHOT_OVERFLOW:  if the socket has any space,
 *	deliver the entire chain. Intended for large requests
 *      that should be delivered in their entirety, or not at all.
 *
 * SB_PRIO_OVERDRAFT:  allow a small (2*MLEN) overflow, over and
 *	aboce normal socket limits. Intended messages indicating
 *      buffer overflow in earlier normal/lower-priority messages .
 *
 * SB_PRIO_BESTEFFORT: Ignore  limits entirely.  Intended only for
 * 	kernel-generated messages to specially-marked scokets which
 *	require "reliable" delivery, nd where the source socket/protocol
 *	message generator enforce some hard limit (but possibly well
 *	above kern.sbmax). It is entirely up to the in-kernel source to
 *	avoid complete mbuf exhaustion or DoS scenarios.
 */
#define SB_PRIO_NONE 	 	0
#define SB_PRIO_ONESHOT_OVERFLOW 1
#define SB_PRIO_OVERDRAFT	2
#define SB_PRIO_BESTEFFORT	3

/*
 * Accept filter functions (duh).
 */
int	accept_filt_getopt(struct socket *, struct sockopt *);
int	accept_filt_setopt(struct socket *, const struct sockopt *);
int	accept_filt_clear(struct socket *);
int	accept_filt_add(struct accept_filter *);
int	accept_filt_del(struct accept_filter *);
struct	accept_filter *accept_filt_get(char *);
#ifdef ACCEPT_FILTER_MOD
#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet_accf);
#endif
void	accept_filter_init(void);
#endif
#ifdef DDB
int sofindproc(struct socket *so, int all, void (*pr)(const char *, ...));
void socket_print(const char *modif, void (*pr)(const char *, ...));
#endif

#endif /* _KERNEL */

#endif /* !_SYS_SOCKETVAR_H_ */