/*
 * 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.
 */

/*
 * t_rcvudata.c and t_rcvvudata.c are very similar and contain common code.
 * Any changes to either of them should be reviewed to see whether they
 * are applicable to the other file.
 */
#include "mt.h"
#include <string.h>
#include <stdlib.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 <syslog.h>
#include "tx.h"


int
_tx_rcvudata(
        int fd,
        struct t_unitdata *unitdata,
        int *flags,
        int api_semantics
)
{
        struct strbuf ctlbuf;
        int retval;
        union T_primitives *pptr;
        struct _ti_user *tiptr;
        int sv_errno;
        int didalloc;
        int flg = 0;

        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
                 */
                if (tiptr->ti_state != T_IDLE) {
                        t_errno = TOUTSTATE;
                        sig_mutex_unlock(&tiptr->ti_lock);
                        return (-1);
                }
        }


        /*
         * check if there is something in look buffer
         */
        if (tiptr->ti_lookcnt > 0) {
                sig_mutex_unlock(&tiptr->ti_lock);
                t_errno = TLOOK;
                return (-1);
        }

        /*
         * 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);
        }

        *flags = 0;

        /*
         * This is a call that may block indefinitely so we drop the
         * lock and allow signals in MT case here and reacquire it.
         * Error case should roll back state changes done above
         * (happens to be no state change here)
         */
        sig_mutex_unlock(&tiptr->ti_lock);
        if ((retval = getmsg(fd, &ctlbuf, (struct strbuf *)&unitdata->udata,
                                &flg)) < 0) {
                if (errno == EAGAIN)
                        t_errno = TNODATA;
                else
                        t_errno = TSYSERR;
                sv_errno = errno;
                sig_mutex_lock(&tiptr->ti_lock);
                errno = sv_errno;
                goto err_out;
        }
        sig_mutex_lock(&tiptr->ti_lock);

        if (((struct strbuf *)&unitdata->udata)->len == -1)
                unitdata->udata.len = 0;

        /*
         * is there control piece with data?
         */
        if (ctlbuf.len > 0) {
                if (ctlbuf.len < (int)sizeof (t_scalar_t)) {
                        unitdata->udata.len = 0;
                        t_errno = TSYSERR;
                        errno = EPROTO;
                        goto err_out;
                }

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

                switch (pptr->type) {

                case T_UNITDATA_IND:
                        if ((ctlbuf.len <
                            (int)sizeof (struct T_unitdata_ind)) ||
                            (pptr->unitdata_ind.OPT_length &&
                            (ctlbuf.len < (int)(pptr->unitdata_ind.OPT_length
                            + pptr->unitdata_ind.OPT_offset)))) {
                                t_errno = TSYSERR;
                                unitdata->udata.len = 0;
                                errno = EPROTO;
                                goto err_out;
                        }

                        if (_T_IS_TLI(api_semantics) ||
                            unitdata->addr.maxlen > 0) {
                                if (TLEN_GT_NLEN(pptr->unitdata_ind.SRC_length,
                                    unitdata->addr.maxlen)) {
                                        t_errno = TBUFOVFLW;
                                        unitdata->udata.len = 0;
                                        goto err_out;
                                }
                                (void) memcpy(unitdata->addr.buf,
                                    ctlbuf.buf + pptr->unitdata_ind.SRC_offset,
                                    (size_t)pptr->unitdata_ind.SRC_length);
                                unitdata->addr.len =
                                    pptr->unitdata_ind.SRC_length;
                        }
                        if (_T_IS_TLI(api_semantics) ||
                            unitdata->opt.maxlen > 0) {
                                if (TLEN_GT_NLEN(pptr->unitdata_ind.OPT_length,
                                    unitdata->opt.maxlen)) {
                                        t_errno = TBUFOVFLW;
                                        unitdata->udata.len = 0;
                                        goto err_out;
                                }
                                (void) memcpy(unitdata->opt.buf, ctlbuf.buf +
                                    pptr->unitdata_ind.OPT_offset,
                                    (size_t)pptr->unitdata_ind.OPT_length);
                                unitdata->opt.len =
                                        pptr->unitdata_ind.OPT_length;
                        }
                        if (retval & MOREDATA)
                                *flags |= T_MORE;
                        /*
                         * No state changes happens on T_RCVUDATA
                         * event (NOOP). We do it only to log errors.
                         */
                        _T_TX_NEXTSTATE(T_RCVUDATA, tiptr,
                            "t_rcvudata: invalid state event T_RCVUDATA");

                        if (didalloc)
                                free(ctlbuf.buf);
                        else
                                tiptr->ti_ctlbuf = ctlbuf.buf;

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

                case T_UDERROR_IND:
                        if (_t_register_lookevent(tiptr, 0, 0, ctlbuf.buf,
                                ctlbuf.len) < 0) {
                                t_errno = TSYSERR;
                                errno = ENOMEM;
                                goto err_out;
                        }
                        unitdata->udata.len = 0;
                        t_errno = TLOOK;
                        goto err_out;

                default:
                        break;
                }

                t_errno = TSYSERR;
                errno = EPROTO;
                goto err_out;

        } else {                /* else part of "if (ctlbuf.len > 0)" */
                unitdata->addr.len = 0;
                unitdata->opt.len = 0;
                /*
                 * only data in message no control piece
                 */
                if (retval & MOREDATA)
                        *flags = T_MORE;
                /*
                 * No state transition occurs on
                 * event T_RCVUDATA. We do it only to
                 * log errors.
                 */
                _T_TX_NEXTSTATE(T_RCVUDATA, tiptr,
                    "t_rcvudata: invalid state event T_RCVUDATA");
                if (didalloc)
                        free(ctlbuf.buf);
                else
                        tiptr->ti_ctlbuf = ctlbuf.buf;
                sig_mutex_unlock(&tiptr->ti_lock);
                return (0);
        }
        /* NOTREACHED */
err_out:
        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);
}