usr/src/sys/sys/socketvar.h

/*
 * Copyright (c) 1982, 1986, 1990 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)socketvar.h 7.14 (Berkeley) %G%
 */

/*
 * 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 */
        short   so_linger;              /* time to linger while closing */
        short   so_state;               /* internal state flags SS_*, below */
        caddr_t so_pcb;                 /* protocol control block */
        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  socket *so_q0;          /* queue of partial connections */
        struct  socket *so_q;           /* queue of incoming connections */
        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 */
/*
 * Variables for socket buffering.
 */
        struct  sockbuf {
                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  proc *sb_sel;   /* process selecting read/write */
                short   sb_flags;       /* flags, see below */
                short   sb_timeo;       /* timeout for read/write */
        } so_rcv, so_snd;
#define SB_MAX          (64*1024)       /* 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_COLL         0x20            /* collision selecting */
#define SB_NOINTR       0x40            /* operations not interruptible */

        caddr_t so_tpcb;                /* Wisc. protocol control block XXX */
};

/*
 * 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_PRIV                 0x080   /* privileged for broadcast, raw... */
#define SS_NBIO                 0x100   /* non-blocking ops */
#define SS_ASYNC                0x200   /* async i/o notify */
#define SS_ISCONFIRMING         0x400   /* deciding to accept connection req */


/*
 * 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_qlen || (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) ((sb)->sb_flags & SB_LOCK ? sb_lock(sb) : \
                ((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)
#define sowwakeup(so)   sowakeup((so), &(so)->so_snd)

#ifdef KERNEL
u_long  sb_max;
/* to catch callers missing new second argument to sonewconn: */
#define sonewconn(head, connstatus)     sonewconn1((head), (connstatus))
struct  socket *sonewconn1();

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

/*
 * Operations on sockets.
 */
struct  file;
int     soo_read __P((                  /* read a socket into a uio structure */
                struct file *fp,
                struct uio *uio,
                struct ucred *cred));
int     soo_write __P((                 /* write socket from a uio structure */
                struct file *fp,
                struct uio *uio,
                struct ucred *cred));
int     soo_ioctl __P((                 /* do an ioctl operation on a socket */
                struct file *fp,
                int com,
                caddr_t data,
                struct proc *p));
int     soo_select __P((                /* do a select operation on a socket */
                struct file *fp,
                int which,
                struct proc *p));
int     soo_close __P((                 /* close socket */
                struct file *fp,
                struct proc *p));