/*	$NetBSD: socketvar.h,v 1.97.2.1 2007/08/15 13:51:01 skrll Exp $	*/

/*-
 * 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>

#if !defined(_KERNEL) || defined(LKM)
struct uio;
struct lwp;
struct uidinfo;
#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 */
	/* 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 */
	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_WANT		0x02		/* someone is waiting to lock */
#define	SB_WAIT		0x04		/* someone is waiting for data/space */
#define	SB_SEL		0x08		/* someone is selecting */
#define	SB_ASYNC	0x10		/* ASYNC I/O, need signals */
#define	SB_UPCALL	0x20		/* someone wants an upcall */
#define	SB_NOINTR	0x40		/* operations not interruptible */
    	/* XXXLUKEM: 0x80 left for FreeBSD's SB_AIO */
#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 socket {
	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 */
	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 */
	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);
	void *		so_upcallarg;	/* Arg for above */
	int		(*so_send) (struct socket *, struct mbuf *,
					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 */
};

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

/*
 * 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_ISDISCONNECTED	0x800	/* socket disconnected from peer */

#define	SS_NBIO			0x080	/* non-blocking ops */
#define	SS_ASYNC		0x100	/* async i/o notify */
#define	SS_ISCONFIRMING		0x200	/* deciding to accept connection req */
#define	SS_MORETOCOME		0x400	/*
					 * hint from sosend to lower layer;
					 * more data coming
					 */
#define	SS_ISAPIPE 		0x1000	/* socket is implementing a pipe */


/*
 * Macros for sockets and socket buffering.
 */

/*
 * Do we need to notify the other side when I/O is possible?
 */
#define	sb_notify(sb)	(((sb)->sb_flags & \
	(SB_WAIT | SB_SEL | SB_ASYNC | SB_UPCALL | SB_KNOTE)) != 0)

/*
 * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
 * This is problematical if the fields are unsigned, as the space might
 * still be negative (cc > hiwat or mbcnt > mbmax).  Should detect
 * overflow and return 0.
 */
#define	sbspace(sb) \
	(lmin((sb)->sb_hiwat - (sb)->sb_cc, (sb)->sb_mbmax - (sb)->sb_mbcnt))

/* do we have to send all at once on a socket? */
#define	sosendallatonce(so) \
	((so)->so_proto->pr_flags & PR_ATOMIC)

/* can we read something from so? */
#define	soreadable(so) \
	((so)->so_rcv.sb_cc >= (so)->so_rcv.sb_lowat || \
	    ((so)->so_state & SS_CANTRCVMORE) || \
	    (so)->so_qlen || (so)->so_error)

/* can we write something to so? */
#define	sowritable(so) \
	((sbspace(&(so)->so_snd) >= (so)->so_snd.sb_lowat && \
	    (((so)->so_state&SS_ISCONNECTED) || \
	      ((so)->so_proto->pr_flags&PR_CONNREQUIRED)==0)) || \
	 ((so)->so_state & SS_CANTSENDMORE) || \
	 (so)->so_error)

/* adjust counters in sb reflecting allocation of m */
#define	sballoc(sb, m)							\
do {									\
	(sb)->sb_cc += (m)->m_len;					\
	(sb)->sb_mbcnt += MSIZE;					\
	if ((m)->m_flags & M_EXT)					\
		(sb)->sb_mbcnt += (m)->m_ext.ext_size;			\
} while (/* CONSTCOND */ 0)

/* adjust counters in sb reflecting freeing of m */
#define	sbfree(sb, m)							\
do {									\
	(sb)->sb_cc -= (m)->m_len;					\
	(sb)->sb_mbcnt -= MSIZE;					\
	if ((m)->m_flags & M_EXT)					\
		(sb)->sb_mbcnt -= (m)->m_ext.ext_size;			\
} while (/* CONSTCOND */ 0)

/*
 * Set lock on sockbuf sb; sleep if lock is already held.
 * Unless SB_NOINTR is set on sockbuf, sleep is interruptible.
 * Returns error without lock if sleep is interrupted.
 */
#define	sblock(sb, wf)							\
	((sb)->sb_flags & SB_LOCK ?					\
	    (((wf) == M_WAITOK) ? sb_lock(sb) : EWOULDBLOCK) :		\
	    ((sb)->sb_flags |= SB_LOCK, 0))

/* release lock on sockbuf sb */
#define	sbunlock(sb)							\
do {									\
	(sb)->sb_flags &= ~SB_LOCK;					\
	if ((sb)->sb_flags & SB_WANT) {					\
		(sb)->sb_flags &= ~SB_WANT;				\
		wakeup((void *)&(sb)->sb_flags);			\
	}								\
} while (/* CONSTCOND */ 0)

#define	sorwakeup(so)							\
do {									\
	if (sb_notify(&(so)->so_rcv))					\
		sowakeup((so), &(so)->so_rcv, POLL_IN);				\
} while (/* CONSTCOND */ 0)

#define	sowwakeup(so)							\
do {									\
	if (sb_notify(&(so)->so_snd))					\
		sowakeup((so), &(so)->so_snd, POLL_OUT);		\
} while (/* CONSTCOND */ 0)

#ifdef _KERNEL
extern u_long		sb_max;
extern int		somaxkva;
extern int		sock_loan_thresh;

/* strings for sleep message: */
extern const char	netio[], netcon[], netcls[];

extern struct pool	socket_pool;

struct mbuf;
struct sockaddr;
struct lwp;
struct msghdr;
struct stat;
struct knote;

/*
 * File operations on sockets.
 */
int	soo_read(struct file *, off_t *, struct uio *, kauth_cred_t, int);
int	soo_write(struct file *, off_t *, struct uio *, kauth_cred_t, int);
int	soo_fcntl(struct file *, u_int cmd, void *, struct lwp *);
int	soo_ioctl(struct file *, u_long cmd, void *, struct lwp *);
int	soo_poll(struct file *, int, struct lwp *);
int	soo_kqfilter(struct file *, struct knote *);
int 	soo_close(struct file *, struct lwp *);
int	soo_stat(struct file *, struct stat *, struct lwp *);
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);
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_lock(struct sockbuf *);
int	sb_max_set(u_long);
void	soinit(void);
int	soabort(struct socket *);
int	soaccept(struct socket *, struct mbuf *);
int	sobind(struct socket *, struct mbuf *, struct lwp *);
void	socantrcvmore(struct socket *);
void	socantsendmore(struct socket *);
int	soclose(struct socket *);
int	soconnect(struct socket *, struct mbuf *, struct lwp *);
int	soconnect2(struct socket *, struct socket *);
int	socreate(int, struct socket **, int, int, struct lwp *);
int	sodisconnect(struct socket *);
void	sofree(struct socket *);
int	sogetopt(struct socket *, int, int, struct mbuf **);
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 socket *
	sonewconn(struct socket *, int);
void	soqinsque(struct socket *, struct socket *, int);
int	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 mbuf *, struct uio *,
	    struct mbuf *, struct mbuf *, int, struct lwp *);
int	sosetopt(struct socket *, int, int, struct mbuf *);
int	soshutdown(struct socket *, int);
void	sowakeup(struct socket *, struct sockbuf *, int);
int	sockargs(struct mbuf **, const void *, size_t, int);

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


int	do_sys_getsockname(struct lwp *, int, int, struct mbuf **);
int	do_sys_sendmsg(struct lwp *, int, struct msghdr *, int, register_t *);
int	do_sys_recvmsg(struct lwp *, int, struct msghdr *, struct mbuf **,
	    struct mbuf **, register_t *);

int	do_sys_bind(struct lwp *, int, struct mbuf *);
int	do_sys_connect(struct lwp *, int, struct mbuf *);
int	do_sys_accept(struct lwp *, int, struct mbuf **, register_t *);


#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))
#else
#define	SBLASTRECORDCHK(sb, where)	/* nothing */
#define	SBLASTMBUFCHK(sb, where)	/* nothing */
#endif /* SOCKBUF_DEBUG */

/* sosend loan */
vaddr_t	sokvaalloc(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

#endif /* _KERNEL */

#endif /* !_SYS_SOCKETVAR_H_ */