libnsl/nsl/t_snddis.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"    /* SVr4.0 1.4.3.1 */

#include "mt.h"
#include <errno.h>
#include <unistd.h>
#include <stropts.h>
#include <sys/stream.h>
#define _SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/timod.h>
#include <xti.h>
#include <signal.h>
#include <syslog.h>
#include "tx.h"

int
_tx_snddis(int fd, const struct t_call *call, int api_semantics)
{
    struct T_discon_req dreq;
    struct strbuf ctlbuf;
    struct strbuf databuf;
    struct _ti_user *tiptr;
    int sv_errno;
    int retval;

    if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
        return (-1);
    sig_mutex_lock(&tiptr->ti_lock);

    if (tiptr->ti_servtype == T_CLTS) {
        t_errno = TNOTSUPPORT;
        sig_mutex_unlock(&tiptr->ti_lock);
        return (-1);
    }

    if (_T_IS_XTI(api_semantics)) {
        /*
         * User level state verification only done for XTI
         * because doing for TLI may break existing applications
         * Note: This is documented in TLI man page but never
         * done.
         */
        if (!(tiptr->ti_state == T_DATAXFER ||
            tiptr->ti_state == T_OUTCON ||
            tiptr->ti_state == T_OUTREL ||
            tiptr->ti_state == T_INREL ||
            (tiptr->ti_state == T_INCON && tiptr->ti_ocnt > 0))) {
            t_errno = TOUTSTATE;
            sig_mutex_unlock(&tiptr->ti_lock);
            return (-1);
        }

        /*
         * Following check only done for XTI as it may be a risk
         * to existing buggy TLI applications.
         */
    }

    if (call != NULL && call->udata.len) {
        if ((tiptr->ti_ddatasize == T_INVALID /* -2 */) ||
            ((tiptr->ti_ddatasize != T_INFINITE /* -1*/) &&
            (call->udata.len >
                (uint32_t)tiptr->ti_ddatasize))) {
            /*
             * user data not valid with disconnect or it
             * exceeds the limits specified by the
             * transport provider
             */
            t_errno = TBADDATA;
            sig_mutex_unlock(&tiptr->ti_lock);
            return (-1);
        }
    }

    /*
     * If disconnect is done on a listener, the 'call' parameter
     * must be non-null
     */
    if ((tiptr->ti_state == T_INCON) &&
        (call == NULL)) {
        t_errno = TBADSEQ;
        sig_mutex_unlock(&tiptr->ti_lock);
        return (-1);
    }

    /*
     * look at look buffer to see if there is a discon there
     */

    if (_t_look_locked(fd, tiptr, 0, api_semantics) == T_DISCONNECT) {
        t_errno = TLOOK;
        sig_mutex_unlock(&tiptr->ti_lock);
        return (-1);
    }

    if ((tiptr->ti_lookcnt > 0) && (call == 0))
        _t_flush_lookevents(tiptr); /* flush but not on listener */

    do {
        retval = ioctl(fd, I_FLUSH, FLUSHW);
    } while (retval < 0 && errno == EINTR);
    if (retval < 0) {
        sv_errno = errno;
        t_errno = TSYSERR;
        sig_mutex_unlock(&tiptr->ti_lock);
        errno = sv_errno;
        return (-1);
    }

    ctlbuf.len = (int)sizeof (struct T_discon_req);
    ctlbuf.maxlen = (int)sizeof (struct T_discon_req);
    ctlbuf.buf = (char *)&dreq;

    dreq.PRIM_type = T_DISCON_REQ;
    dreq.SEQ_number = (call? call->sequence: -1);

    databuf.maxlen = (call? call->udata.len: 0);
    databuf.len = (call? call->udata.len: 0);
    databuf.buf = (call? call->udata.buf: NULL);

    /*
     * Calls to send data (write or putmsg) can potentially
     * block, for MT case, we drop the lock and enable signals here
     * and acquire it back
     */
    sig_mutex_unlock(&tiptr->ti_lock);
    if (putmsg(fd, &ctlbuf, (databuf.len? &databuf: NULL), 0) < 0) {
        t_errno = TSYSERR;
        return (-1);
    }
    sig_mutex_lock(&tiptr->ti_lock);

    if (_t_is_ok(fd, tiptr, T_DISCON_REQ) < 0) {
        sv_errno = errno;
        sig_mutex_unlock(&tiptr->ti_lock);
        errno = sv_errno;
        return (-1);
    }

    tiptr->ti_flags &= ~(MORE|EXPEDITED);

    if (tiptr->ti_ocnt <= 1) {
        if (tiptr->ti_state == T_INCON) {
            tiptr->ti_ocnt--;
            tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
        }
        _T_TX_NEXTSTATE(T_SNDDIS1, tiptr,
                "t_snddis: invalid state event T_SNDDIS1");
    } else {
        if (tiptr->ti_state == T_INCON) {
            tiptr->ti_ocnt--;
            tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
        }
        _T_TX_NEXTSTATE(T_SNDDIS2, tiptr,
                "t_snddis: invalid state event T_SNDDIS2");
    }

    sig_mutex_unlock(&tiptr->ti_lock);
    return (0);
}