/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * Kernel TLI-like function to allow a trasnport endpoint to initiate a
 * connection to another transport endpoint.  This function will wait for
 * an ack and a T_CONN_CON before returning.
 *
 * Returns:
 *      0 on success, and if rcvcall is non-NULL it shall be
 *      filled with the connection confirm data.
 *      Otherwise a positive error code.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/user.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/errno.h>
#include <sys/stream.h>
#include <sys/ioctl.h>
#include <sys/stropts.h>
#include <sys/tihdr.h>
#include <sys/timod.h>
#include <sys/tiuser.h>
#include <sys/t_kuser.h>
#include <sys/strsubr.h>
#include <sys/sysmacros.h>
#include <sys/strsun.h>


int
t_kconnect(TIUSER *tiptr, struct t_call *sndcall, struct t_call *rcvcall)
{
        int                     len;
        int                     msgsz;
        size_t                  hdrsz;
        struct T_conn_req       *creq;
        union T_primitives      *pptr;
        mblk_t                  *nbp;
        file_t                  *fp;
        mblk_t                  *bp;
        int                     error;
        int                     flag;

        error = 0;

        fp = tiptr->fp;
        msgsz = (int)TCONNREQSZ;
        /*
         * Usually connect()s are performed with the credential of the caller;
         * in this particular case we specifically use the credential of
         * the opener as this call is typically done in the context of a user
         * process but on behalf of the kernel, e.g., a client connection
         * to a server which is later shared by different users.
         * At open time, we make sure to set fp->f_cred to kcred if such is
         * the case.
         *
         * Note: if the receiver uses SCM_UCRED/getpeerucred the pid will
         * appear as -1.
         */
        while (!(bp = allocb_cred(msgsz + sndcall->addr.len + sndcall->opt.len,
            fp->f_cred, NOPID))) {
                if (strwaitbuf(msgsz + sndcall->addr.len + sndcall->opt.len,
                    BPRI_LO))
                        return (ENOSR);
        }

        /* LINTED pointer alignment */
        creq = (struct T_conn_req *)bp->b_wptr;
        creq->PRIM_type = T_CONN_REQ;
        creq->DEST_length = (t_scalar_t)sndcall->addr.len;
        creq->OPT_length = (t_scalar_t)sndcall->opt.len;

        if (sndcall->addr.len) {
                bcopy(sndcall->addr.buf, (bp->b_wptr+msgsz), sndcall->addr.len);
                creq->DEST_offset = (t_scalar_t)msgsz;
                msgsz += sndcall->addr.len;
        } else
                creq->DEST_offset = (t_scalar_t)0;

        if (sndcall->opt.len) {
                bcopy(sndcall->opt.buf, (bp->b_wptr+msgsz), sndcall->opt.len);
                creq->OPT_offset = (t_scalar_t)msgsz;
                msgsz += sndcall->opt.len;
        } else
                creq->OPT_offset = (t_scalar_t)0;

        bp->b_datap->db_type = M_PROTO;
        bp->b_wptr += msgsz;

        /*
         * copy the users data, if any.
         */
        if (sndcall->udata.len) {
                /*
                 * if CO then we would allocate a data block and
                 * put the users connect data into it.
                 */
                KTLILOG(1,
                    "Attempt to send connectionless data on T_CONN_REQ\n", 0);
                freemsg(bp);
                return (EPROTO);
        }

        flag = fp->f_flag;

        /*
         * send it
         */
        if ((error = tli_send(tiptr, bp, flag)) != 0)
                return (error);

        /*
         * wait for acknowledgment
         */
        if ((error = get_ok_ack(tiptr, T_CONN_REQ, flag)) != 0)
                return (error);

        bp = NULL;
        /*
         * wait for CONfirm
         */
        if ((error = tli_recv(tiptr, &bp, flag)) != 0)
                return (error);

        if (bp->b_datap->db_type != M_PROTO) {
                freemsg(bp);
                return (EPROTO);
        }

        /* LINTED pointer alignment */
        pptr = (union T_primitives *)bp->b_rptr;
        switch (pptr->type) {
        case T_CONN_CON:
                hdrsz = MBLKL(bp);

                /*
                 * check everything for consistency
                 */
                if (hdrsz < TCONNCONSZ ||
                    hdrsz < (pptr->conn_con.OPT_length +
                    pptr->conn_con.OPT_offset) ||
                    hdrsz < (pptr->conn_con.RES_length +
                    pptr->conn_con.RES_offset)) {
                        error = EPROTO;
                        freemsg(bp);
                        break;
                }

                if (rcvcall != NULL) {
                        /*
                         * okay, so now we copy them
                         */
                        len = MIN(pptr->conn_con.RES_length,
                            rcvcall->addr.maxlen);
                        bcopy(bp->b_rptr + pptr->conn_con.RES_offset,
                            rcvcall->addr.buf, len);
                        rcvcall->addr.len = len;

                        len = MIN(pptr->conn_con.OPT_length,
                            rcvcall->opt.maxlen);
                        bcopy(bp->b_rptr + pptr->conn_con.OPT_offset,
                            rcvcall->opt.buf, len);
                        rcvcall->opt.len = len;

                        if (bp->b_cont) {
                                nbp = bp;
                                bp = bp->b_cont;
                                msgsz = (int)MBLKL(bp);
                                len = MIN(msgsz, rcvcall->udata.maxlen);
                                bcopy(bp->b_rptr, rcvcall->udata.buf, len);
                                rcvcall->udata.len = len;
                                freemsg(nbp);
                        }
                } else {
                        freemsg(bp);
                }
                break;

        case T_DISCON_IND:
                /*
                 * TCP puts the errno here, i.e.
                 * ETIMEDOUT, ECONNREFUSED
                 */
                error = pptr->discon_ind.DISCON_reason;
                freemsg(bp);
                break;

        default:
                error = EPROTO;
                freemsg(bp);
                break;
        }
        return (error);
}