socketvar.h

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/*-
 * 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.
 * 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.
 *
 *      @(#)socketvar.h 8.3 (Berkeley) 2/19/95
 * $FreeBSD: src/sys/sys/socketvar.h,v 1.135 2004/10/18 22:19:43 rwatson Exp $
 */

#ifndef _SYS_SOCKETVAR_H_
#define _SYS_SOCKETVAR_H_

#include <sys/queue.h>                  /* for TAILQ macros */
#include <sys/select.h>                 /* for struct selinfo */


/*
 * Kernel structure per socket.
 * Contains send and receive buffer queues,
 * handle on protocol and pointer to protocol
 * private data and error information.
 */
typedef u_quad_t so_gen_t;

struct socket {
        short   so_type;                /* generic type, see socket.h */
        short   so_options;             /* from socket call, see socket.h */
        short   so_linger;              /* time to linger while closing */
        short   so_state;               /* internal state flags SS_*, below */
        void    *so_pcb;                /* protocol control block */
        struct  protosw *so_proto;      /* protocol handle */
/*
 * Variables for connection queuing.
 * 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 */
        TAILQ_HEAD(, socket) so_incomp; /* queue of partial unaccepted connections */
        TAILQ_HEAD(, socket) so_comp;   /* queue of complete unaccepted connections */
        TAILQ_ENTRY(socket) so_list;    /* list of unaccepted connections */
        short   so_qlen;                /* number of unaccepted connections */
        short   so_incqlen;             /* number of unaccepted incomplete
                                           connections */
        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 */
/*
 * Variables for socket buffering.
 */
        struct sockbuf {
                u_int   sb_cc;          /* actual chars in buffer */
                u_int   sb_hiwat;       /* max actual char count */
                u_int   sb_mbcnt;       /* chars of mbufs used */
                u_int   sb_mbmax;       /* max chars of mbufs to use */
                int     sb_lowat;       /* low water mark */
                struct  mbuf *sb_mb;    /* the mbuf chain */
                struct  selinfo sb_sel; /* process selecting read/write */
                short   sb_flags;       /* flags, see below */
                int     sb_timeo;       /* timeout for read/write */
                void    (*sb_wakeup)(struct socket *, void *);
                void    *sb_wakeuparg;  /* arg for above */
        } so_rcv, so_snd;
#define SB_MAX          (256L*1024L)    /* default for max chars in sockbuf */
#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_NOTIFY       (SB_WAIT|SB_SEL|SB_ASYNC)
#define SB_NOINTR       0x40            /* operations not interruptible */

        caddr_t so_tpcb;                /* Wisc. protocol control block XXX */
        void    (*so_upcall)(struct socket *, void *arg, int);
        void    *so_upcallarg;          /* Arg for above */
};

/*
 * Socket state bits.
 */
#define SS_NOFDREF              0x0001  /* no file table ref any more */
#define SS_ISCONNECTED          0x0002  /* socket connected to a peer */
#define SS_ISCONNECTING         0x0004  /* in process of connecting to peer */
#define SS_ISDISCONNECTING      0x0008  /* in process of disconnecting */
#define SS_CANTSENDMORE         0x0010  /* can't send more data to peer */
#define SS_CANTRCVMORE          0x0020  /* can't receive more data from peer */
#define SS_RCVATMARK            0x0040  /* at mark on input */

#define SS_PRIV                 0x0080  /* privileged for broadcast, raw... */
#define SS_NBIO                 0x0100  /* non-blocking ops */
#define SS_ASYNC                0x0200  /* async i/o notify */
#define SS_ISCONFIRMING         0x0400  /* deciding to accept connection req */

#define SS_INCOMP               0x0800  /* unaccepted, incomplete connection */
#define SS_COMP                 0x1000  /* unaccepted, complete connection */


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

/*
 * 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.  Should use "lmin" but it doesn't exist now.
 */
#define sbspace(sb) \
    ((long) imin((int)((sb)->sb_hiwat - (sb)->sb_cc), \
         (int)((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_comp.tqh_first || (so)->so_error)

/* can we write something to so? */
#define sowriteable(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) { \
        (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 */
#define sbfree(sb, m) { \
        (sb)->sb_cc -= (m)->m_len; \
        (sb)->sb_mbcnt -= MSIZE; \
        if ((m)->m_flags & M_EXT) \
                (sb)->sb_mbcnt -= (m)->m_ext.ext_size; \
}

/*
 * 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) { \
        (sb)->sb_flags &= ~SB_LOCK; \
        if ((sb)->sb_flags & SB_WANT) { \
                (sb)->sb_flags &= ~SB_WANT; \
                wakeup((caddr_t)&(sb)->sb_flags); \
        } \
}

#define sorwakeup(so)   { sowakeup((so), &(so)->so_rcv); \
                          if ((so)->so_upcall) \
                            (*((so)->so_upcall))((so), (so)->so_upcallarg, M_DONTWAIT); \
                        }

#define sowwakeup(so)   sowakeup((so), &(so)->so_snd)

#ifdef _KERNEL
extern u_long   sb_max;

/* to catch callers missing new second argument to sonewconn: */
#define sonewconn(head, connstatus)     sonewconn1((head), (connstatus))

struct filedesc;
struct mbuf;
struct sockaddr;
struct stat;

/*
 * From uipc_socket and friends
 */
int     sockargs(struct mbuf **mp, caddr_t buf, int buflen, int type);
void    sbappend(struct sockbuf *sb, struct mbuf *m);
int     sbappendaddr(struct sockbuf *sb, struct sockaddr *asa,
            struct mbuf *m0, struct mbuf *control);
int     sbappendcontrol(struct sockbuf *sb, struct mbuf *m0,
            struct mbuf *control);
void    sbappendrecord(struct sockbuf *sb, struct mbuf *m0);
void    sbcheck(struct sockbuf *sb);
void    sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n);
struct mbuf *
        sbcreatecontrol(caddr_t p, int size, int type, int level);
void    sbdrop(struct sockbuf *sb, int len);
void    sbdroprecord(struct sockbuf *sb);
void    sbflush(struct sockbuf *sb);
void    sbinsertoob(struct sockbuf *sb, struct mbuf *m0);
void    sbrelease(struct sockbuf *sb);
int     sbreserve(struct sockbuf *sb, u_long cc);
int     sbwait(struct sockbuf *sb);
int     sb_lock(struct sockbuf *sb);
int     soabort(struct socket *so);
int     soaccept(struct socket *so, struct mbuf *nam);
int     sobind(struct socket *so, struct mbuf *nam);
void    socantrcvmore(struct socket *so);
void    socantsendmore(struct socket *so);
int     soclose(struct socket *so);
int     soconnect(struct socket *so, struct mbuf *nam);
int     soconnect2(struct socket *so1, struct socket *so2);
int     socreate(int dom, struct socket **aso, int type, int proto,
            struct proc *p);
int     sodisconnect(struct socket *so);
void    sofree(struct socket *so);
int     sogetopt(struct socket *so, int level, int optname,
            struct mbuf **mp);
void    sohasoutofband(struct socket *so);
void    soisconnected(struct socket *so);
void    soisconnecting(struct socket *so);
void    soisdisconnected(struct socket *so);
void    soisdisconnecting(struct socket *so);
int     solisten(struct socket *so, int backlog);
struct socket *
        sodropablereq(struct socket *head);
struct socket *
        sonewconn1(struct socket *head, int connstatus);
int     soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
            struct mbuf **mp0, struct mbuf **controlp, int *flagsp);
int     soreserve(struct socket *so, u_long sndcc, u_long rcvcc);
void    sorflush(struct socket *so);
int     sosend(struct socket *so, struct mbuf *addr, struct uio *uio,
            struct mbuf *top, struct mbuf *control, int flags);
int     sosetopt(struct socket *so, int level, int optname,
            struct mbuf *m0);
int     soshutdown(struct socket *so, int how);
void    sowakeup(struct socket *so, struct sockbuf *sb);
#endif /* _KERNEL */

#endif /* !_SYS_SOCKETVAR_H_ */