usr/src/sys/h/socketvar.h

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *      @(#)socketvar.h 7.1 (Berkeley) 6/4/86
 */

/*
 * 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 */
        short   so_q0len;               /* partials on so_q0 */
        struct  socket *so_q;           /* queue of incoming connections */
        short   so_qlen;                /* number of connections on so_q */
        short   so_qlimit;              /* max number queued connections */
/*
 * Variables for socket buffering.
 */
        struct  sockbuf {
                u_short sb_cc;          /* actual chars in buffer */
                u_short sb_hiwat;       /* max actual char count */
                u_short sb_mbcnt;       /* chars of mbufs used */
                u_short sb_mbmax;       /* max chars of mbufs to use */
                u_short sb_lowat;       /* low water mark (not used yet) */
                short   sb_timeo;       /* timeout (not used yet) */
                struct  mbuf *sb_mb;    /* the mbuf chain */
                struct  proc *sb_sel;   /* process selecting read/write */
                short   sb_flags;       /* flags, see below */
        } so_rcv, so_snd;
#define SB_MAX          65535           /* max chars in sockbuf */
#define SB_LOCK         0x01            /* lock on data queue (so_rcv only) */
#define SB_WANT         0x02            /* someone is waiting to lock */
#define SB_WAIT         0x04            /* someone is waiting for data/space */
#define SB_SEL          0x08            /* buffer is selected */
#define SB_COLL         0x10            /* collision selecting */
        short   so_timeo;               /* connection timeout */
        u_short so_error;               /* error affecting connection */
        u_short so_oobmark;             /* chars to oob mark */
        short   so_pgrp;                /* pgrp for signals */
};

/*
 * 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 */


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

/* how much space is there in a socket buffer (so->so_snd or so->so_rcv) */
#define sbspace(sb) \
    (MIN((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_state & SS_CANTRCVMORE) || \
        (so)->so_qlen || (so)->so_error)

/* can we write something to so? */
#define sowriteable(so) \
    (sbspace(&(so)->so_snd) > 0 && \
        (((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_off > MMAXOFF) \
                (sb)->sb_mbcnt += CLBYTES; \
}

/* 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_off > MMAXOFF) \
                (sb)->sb_mbcnt -= CLBYTES; \
}

/* set lock on sockbuf sb */
#define sblock(sb) { \
        while ((sb)->sb_flags & SB_LOCK) { \
                (sb)->sb_flags |= SB_WANT; \
                sleep((caddr_t)&(sb)->sb_flags, PZERO+1); \
        } \
        (sb)->sb_flags |= SB_LOCK; \
}

/* 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
struct  socket *sonewconn();
#endif