/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "mt.h"
#include <stdlib.h>
#include <string.h>
#include <errno.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_rcvdis(int fd, struct t_discon *discon, int api_semantics)
{
        struct strbuf ctlbuf;
        struct strbuf databuf;
        int retval;
        union T_primitives *pptr;
        struct _ti_user *tiptr;
        int sv_errno;
        int flg = 0;
        int didalloc, didralloc;
        int use_lookbufs = 0;

        if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL)
                return (-1);

        /*
         * Acquire per thread lock.
         * Note: Lock is held across most of this routine
         * including the blocking getmsg() call. This is fine
         * because it is first verfied that an event is pending
         */
        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
                 */
                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);
                }
        }
        /*
         * Handle likely scenario as special case:
         * Is there a discon in look buffer as the first
         * event in the lookbuffer, is so just get it.
         */
        if ((tiptr->ti_lookcnt > 0) &&
            /* LINTED pointer cast */
            (*((t_scalar_t *)tiptr->ti_lookbufs.tl_lookcbuf) == T_DISCON_IND)) {
                /*
                 * The T_DISCON_IND is already in the look buffer
                 */
                ctlbuf.len = tiptr->ti_lookbufs.tl_lookclen;
                ctlbuf.buf = tiptr->ti_lookbufs.tl_lookcbuf;
                /* Note: ctlbuf.maxlen not used in this case */

                databuf.len = tiptr->ti_lookbufs.tl_lookdlen;
                databuf.buf = tiptr->ti_lookbufs.tl_lookdbuf;
                /* Note databuf.maxlen not used in this case */

                use_lookbufs = 1;

        } else {

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

                if (retval != T_DISCONNECT) {
                        t_errno = TNODIS;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        return (-1);
                }

                /*
                 * get disconnect off read queue.
                 * use ctl and rcv buffers
                 *
                 * Acquire ctlbuf for use in sending/receiving control part
                 * of the message.
                 */
                if (_t_acquire_ctlbuf(tiptr, &ctlbuf, &didalloc) < 0) {
                        sv_errno = errno;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        errno = sv_errno;
                        return (-1);
                }

                /*
                 * Acquire databuf for use in sending/receiving data part
                 */
                if (_t_acquire_databuf(tiptr, &databuf, &didralloc) < 0) {
                        sv_errno = errno;
                        if (didalloc)
                                free(ctlbuf.buf);
                        else
                                tiptr->ti_ctlbuf = ctlbuf.buf;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        errno = sv_errno;
                        return (-1);
                }

                /*
                 * Since we already verified that a disconnect event
                 * is present, we assume that this getmsg() cannot
                 * block indefinitely
                 */
                do {
                        retval = getmsg(fd, &ctlbuf, &databuf, &flg);
                } while (retval < 0 && errno == EINTR);

                if (retval  < 0) {
                        t_errno = TSYSERR;
                        goto err_out;
                }
                if (databuf.len == -1) databuf.len = 0;

                /*
                 * did I get entire message?
                 */
                if (retval > 0) {
                        t_errno = TSYSERR;
                        errno = EIO;
                        goto err_out;
                }
        }


        /* LINTED pointer cast */
        pptr = (union T_primitives *)ctlbuf.buf;

        if ((ctlbuf.len < (int)sizeof (struct T_discon_ind)) ||
            (pptr->type != T_DISCON_IND)) {
                t_errno = TSYSERR;
                errno = EPROTO;
                goto err_out;
        }

        /*
         * clear more and expedited flags
         */
        tiptr->ti_flags &= ~(MORE | EXPEDITED);

        if (tiptr->ti_ocnt <= 0) {
                _T_TX_NEXTSTATE(T_RCVDIS1, tiptr,
                                "t_rcvdis: invalid state event T_RCVDIS1");
        } else {
                if (tiptr->ti_ocnt == 1) {
                        _T_TX_NEXTSTATE(T_RCVDIS2, tiptr,
                                "t_rcvdis: invalid state event T_RCVDIS2");
                } else {
                        _T_TX_NEXTSTATE(T_RCVDIS3, tiptr,
                                "t_rcvdis: invalid state event T_RCVDIS3");
                }
                tiptr->ti_ocnt--;
                tiptr->ti_flags &= ~TX_TQFULL_NOTIFIED;
        }

        if (discon != NULL) {
                if (_T_IS_TLI(api_semantics) || discon->udata.maxlen > 0) {
                        if (databuf.len > (int)discon->udata.maxlen) {
                                t_errno = TBUFOVFLW;
                                goto err_out;
                        }
                        (void) memcpy(discon->udata.buf, databuf.buf,
                            (size_t)databuf.len);
                        discon->udata.len = databuf.len;
                }
                discon->reason = pptr->discon_ind.DISCON_reason;
                discon->sequence = pptr->discon_ind.SEQ_number;
        }
        if (use_lookbufs)
                _t_free_looklist_head(tiptr);
        else {
                if (didalloc)
                        free(ctlbuf.buf);
                else
                        tiptr->ti_ctlbuf = ctlbuf.buf;
                if (didralloc)
                        free(databuf.buf);
                else
                        tiptr->ti_rcvbuf = databuf.buf;
        }
        sig_mutex_unlock(&tiptr->ti_lock);
        return (0);

err_out:
        sv_errno = errno;

        if (use_lookbufs)
                _t_free_looklist_head(tiptr);
        else {
                if (didalloc)
                        free(ctlbuf.buf);
                else
                        tiptr->ti_ctlbuf = ctlbuf.buf;
                if (didralloc)
                        free(databuf.buf);
                else
                        tiptr->ti_rcvbuf = databuf.buf;
        }
        sig_mutex_unlock(&tiptr->ti_lock);
        errno = sv_errno;
        return (-1);
}