/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
 */


#include "mt.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 <assert.h>
#include <syslog.h>
#include "tx.h"


/*
 * 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.
 */
int
_tx_sndv(int fd, const struct t_iovec *tiov, unsigned int tiovcount,
    int flags, int api_semantics)
{
        struct T_data_req datareq;
        struct strbuf ctlbuf, databuf;
        unsigned int bytes_sent, bytes_remaining, bytes_to_send, nbytes;
        char *curptr;
        struct iovec iov[T_IOV_MAX];
        int iovcount;
        char *dataptr = NULL;
        int first_time;
        struct _ti_user *tiptr;
        int band;
        int retval, lookevent;
        int sv_errno;
        int doputmsg = 0;
        int32_t tsdu_limit;

        assert(api_semantics == TX_XTI_XNS5_API);
        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 (tiovcount == 0 || tiovcount > T_IOV_MAX) {
                t_errno = TBADDATA;
                sig_mutex_unlock(&tiptr->ti_lock);
                return (-1);
        }

        if (!(tiptr->ti_state == T_DATAXFER ||
            tiptr->ti_state == T_INREL)) {
                t_errno = TOUTSTATE;
                sig_mutex_unlock(&tiptr->ti_lock);
                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);
                return (-1);
        }
        if (flags & T_EXPEDITED)
                tsdu_limit = tiptr->ti_etsdusize;
        else {
                /* normal data */
                tsdu_limit = tiptr->ti_tsdusize;
        }

        /*
         * nbytes is the sum of the bytecounts in the tiov vector
         * A value larger than INT_MAX is truncated to INT_MAX by
         * _t_bytecount_upto_intmax()
         */
        nbytes = _t_bytecount_upto_intmax(tiov, tiovcount);

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

        /*
         * Check for incoming disconnect only. XNS Issue 5 makes it optional
         * to check for incoming orderly release
         */
        lookevent = _t_look_locked(fd, tiptr, 0, api_semantics);
        if (lookevent < 0) {
                sv_errno = errno;
                sig_mutex_unlock(&tiptr->ti_lock);
                errno = sv_errno;
                return (-1);
        }
        if (lookevent == T_DISCONNECT) {
                t_errno = TLOOK;
                sig_mutex_unlock(&tiptr->ti_lock);
                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);
                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;
                /*
                 * Allocate a databuffer into which we will gather the
                 * input vector data, and make a call to putmsg(). We
                 * do this since we don't have the equivalent of a putmsgv()
                 */
                if (nbytes != 0) {
                        if ((dataptr = malloc((size_t)nbytes)) == NULL) {
                                sv_errno = errno;
                                sig_mutex_unlock(&tiptr->ti_lock);
                                errno = sv_errno;
                                t_errno = TSYSERR;
                                return (-1); /* error */
                        }
                        /*
                         * Gather the input buffers, into the single linear
                         * buffer allocated above, while taking care to see
                         * that no more than INT_MAX bytes will be copied.
                         */
                        _t_gather(dataptr, tiov, tiovcount);
                        curptr = dataptr; /* Initialize for subsequent use */
                } else {
                        dataptr = NULL;
                        curptr = NULL;
                }
        }

        bytes_remaining = nbytes;
        /*
         * 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);
        first_time = 1;
        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;
                                curptr = curptr + bytes_sent;
                        }
                } 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.
                         */
                        /*
                         * The first time, setup the tiovec for doing a writev
                         * call. We assume that T_IOV_MAX <= IOV_MAX.
                         * Since writev may return a partial count, we need
                         * the loop. After the first time, we just adjust
                         * the iov vector to not include the already
                         * written bytes.
                         */
                        if (first_time) {
                                first_time = 0;
                                _t_copy_tiov_to_iov(tiov, tiovcount, iov,
                                    &iovcount);
                        } else {
                                /*
                                 * bytes_sent - value set below in the previous
                                 * iteration of the loop is used now.
                                 */
                                _t_adjust_iov(bytes_sent, iov, &iovcount);
                        }
                        retval = (int)writev(fd, iov, iovcount);
                        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;
                                if (dataptr)
                                        free(dataptr);
                                return (-1); /* return error */
                        }
                        /*
                         * 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;
        } while (bytes_remaining != 0);

        if (dataptr != NULL)
                free(dataptr);
        _T_TX_NEXTSTATE(T_SND, tiptr, "t_snd: invalid state event T_SND");
        return (nbytes - bytes_remaining);
}