libnsl/nsl/t_snd.c

	t_snd.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#pragma ident   "%Z%%M% %I% %E% SMI"    /* SVr4.0 1.3.1.2 */

/*
 * t_snd.c and t_sndv.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 <rpc/trace.h>
#include <unistd.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_snd(int fd, char *buf, unsigned nbytes, int flags, int api_semantics)
{
    struct T_data_req datareq;
    struct strbuf ctlbuf, databuf;
    unsigned int bytes_sent, bytes_remaining, bytes_to_send;
    char *curptr;
    struct _ti_user *tiptr;
    int band;
    int retval, lookevent;
    int sv_errno;
    int doputmsg = 0;
    int32_t tsdu_limit;

    trace4(TR_t_snd, 0, fd, nbytes, flags);
    if ((tiptr = _t_checkfd(fd, 0, api_semantics)) == NULL) {
        sv_errno = errno;
        trace4(TR_t_snd, 1, fd, nbytes, flags);
        errno = sv_errno;
        return (-1);
    }
    sig_mutex_lock(&tiptr->ti_lock);

    if (tiptr->ti_servtype == T_CLTS) {
        t_errno = TNOTSUPPORT;
        sig_mutex_unlock(&tiptr->ti_lock);
        trace4(TR_t_snd, 1, fd, nbytes, flags);
        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_INREL)) {
            t_errno = TOUTSTATE;
            sig_mutex_unlock(&tiptr->ti_lock);
            trace4(TR_t_snd, 1, fd, nbytes, flags);
            return (-1);
        }
        /*
         * XXX
         * Is it OK to do this TBADFLAG check when XTI spec
         * is being extended with new and interesting flags
         * everyday ?
         */
        if ((flags & ~(TX_ALL_VALID_FLAGS)) != 0) {
            t_errno = TBADFLAG;
            sig_mutex_unlock(&tiptr->ti_lock);
            trace4(TR_t_snd, 1, fd, nbytes, flags);
            return (-1);
        }
        if (flags & T_EXPEDITED)
            tsdu_limit = tiptr->ti_etsdusize;
        else {
            /* normal data */
            tsdu_limit = tiptr->ti_tsdusize;
        }

        if ((tsdu_limit > 0) && /* limit meaningful and ... */
            (nbytes > (uint32_t)tsdu_limit)) {
            t_errno = TBADDATA;
            sig_mutex_unlock(&tiptr->ti_lock);
            trace4(TR_t_snd, 1, fd, nbytes, flags);
            return (-1);
        }

        /*
         * Check for incoming disconnect or orderly release
         * Did anyone say "performance" ? Didn't hear that.
         */
        lookevent = _t_look_locked(fd, tiptr, 0, api_semantics);
        if (lookevent < 0) {
            sv_errno = errno;
            sig_mutex_unlock(&tiptr->ti_lock);
            trace4(TR_t_snd, 1, fd, nbytes, flags);
            errno = sv_errno;
            return (-1);
        }
        /*
         * XNS 4 required the TLOOK error to be returned if there
         * is any incoming T_ORDREL. XNS 5 does not require an
         * error to be returned in such a case.
         */
        if (lookevent == T_DISCONNECT ||
            (api_semantics == TX_XTI_XNS4_API &&
            lookevent == T_ORDREL)) {
            t_errno = TLOOK;
            sig_mutex_unlock(&tiptr->ti_lock);
            trace4(TR_t_snd, 1, fd, nbytes, flags);
            return (-1);
        }
    }

    /* sending zero length data when not allowed */
    if (nbytes == 0 && !(tiptr->ti_prov_flag & (SENDZERO|OLD_SENDZERO))) {
        t_errno = TBADDATA;
        sig_mutex_unlock(&tiptr->ti_lock);
        trace4(TR_t_snd, 1, fd, nbytes, flags);
        return (-1);
    }

    doputmsg = (tiptr->ti_tsdusize != 0) || (flags & T_EXPEDITED);

    if (doputmsg) {
        /*
         * Initialize ctlbuf for use in sending/receiving control part
         * of the message.
         */
        ctlbuf.maxlen = (int)sizeof (struct T_data_req);
        ctlbuf.len = (int)sizeof (struct T_data_req);
        ctlbuf.buf = (char *)&datareq;

        band = TI_NORMAL; /* band 0 */
        if (flags & T_EXPEDITED) {
            datareq.PRIM_type = T_EXDATA_REQ;
            if (! (tiptr->ti_prov_flag & EXPINLINE))
                band = TI_EXPEDITED; /* band > 0 */
        } else
            datareq.PRIM_type = T_DATA_REQ;
    }

    bytes_remaining = nbytes;
    curptr = buf;

    /*
     * 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);
    do {
        bytes_to_send = bytes_remaining;
        if (doputmsg) {
            /*
             * transport provider supports TSDU concept
             * (unlike TCP) or it is expedited data.
             * In this case do the fragmentation
             */
            if (bytes_to_send > (unsigned int)tiptr->ti_maxpsz) {
                datareq.MORE_flag = 1;
                bytes_to_send = (unsigned int)tiptr->ti_maxpsz;
            } else {
                if (flags&T_MORE)
                    datareq.MORE_flag = 1;
                else
                    datareq.MORE_flag = 0;
            }
            databuf.maxlen = bytes_to_send;
            databuf.len = bytes_to_send;
            databuf.buf = curptr;
            retval = putpmsg(fd, &ctlbuf, &databuf, band, MSG_BAND);
            if (retval == 0)
                bytes_sent = bytes_to_send;
        } else {
            /*
             * transport provider does *not* support TSDU concept
             * (e.g. TCP) and it is not expedited data. A
             * perf. optimization is used. Note: the T_MORE
             * flag is ignored here even if set by the user.
             */
            retval = write(fd, curptr, bytes_to_send);
            if (retval >= 0) {
                /* Amount that was actually sent */
                bytes_sent = retval;
            }
        }

        if (retval < 0) {
            if (nbytes == bytes_remaining) {
                /*
                 * Error on *first* putmsg/write attempt.
                 * Return appropriate error
                 */
                if (errno == EAGAIN)
                    t_errno = TFLOW;
                else
                    t_errno = TSYSERR;
                sv_errno = errno;
                trace4(TR_t_snd, 1, fd, nbytes, flags);
                errno = sv_errno;
                return (-1); /* return error */
            } else {
                /*
                 * Not the first putmsg/write
                 * [ partial completion of t_snd() case.
                 *
                 * Error on putmsg/write attempt but
                 * some data was transmitted so don't
                 * return error. Don't attempt to
                 * send more (break from loop) but
                 * return OK.
                 */
                break;
            }
        }
        bytes_remaining = bytes_remaining - bytes_sent;
        curptr = curptr + bytes_sent;
    } while (bytes_remaining != 0);

    _T_TX_NEXTSTATE(T_SND, tiptr, "t_snd: invalid state event T_SND");
    sv_errno = errno;
    trace4(TR_t_snd, 1, fd, nbytes, flags);
    errno = sv_errno;
    return (nbytes - bytes_remaining);
}