/*
 * Copyright (c) 2000-2001 Boris Popov
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Boris Popov.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: smb_trantcp.c,v 1.39 2005/03/02 01:27:44 lindak Exp $
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/autoconf.h>
#include <sys/sysmacros.h>
#include <sys/sunddi.h>
#include <sys/kmem.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/poll.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/stropts.h>
#include <sys/cmn_err.h>
#include <sys/tihdr.h>
#include <sys/tiuser.h>
#include <sys/t_kuser.h>
#include <sys/priv.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include <netsmb/smb_osdep.h>
#include <netsmb/mchain.h>
#include <netsmb/netbios.h>

#include <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>
#include <netsmb/smb_tran.h>
#include <netsmb/smb_trantcp.h>

static int  nb_disconnect(struct nbpcb *nbp);


/*
 * Get mblks into *mpp until the data length is at least mlen.
 * Note that *mpp may already contain a fragment.
 *
 * If we ever have to wait more than 15 sec. to read a message,
 * return ETIME.  (Caller will declare the VD dead.)
 */
static int
nb_getmsg_mlen(struct nbpcb *nbp, mblk_t **mpp, size_t mlen)
{
        mblk_t *im, *tm;
        union T_primitives      *pptr;
        size_t dlen;
        int events, fmode, timo, waitflg;
        int error = 0;

        /* We should be the only reader. */
        ASSERT(nbp->nbp_flags & NBF_RECVLOCK);
        /* nbp->nbp_tiptr checked by caller */

        /*
         * Get the first message (fragment) if
         * we don't already have a left-over.
         */
        dlen = msgdsize(*mpp); /* *mpp==null is OK */
        while (dlen < mlen) {

                /*
                 * I think we still want this to return ETIME
                 * if nothing arrives for SMB_NBTIMO (15) sec.
                 * so we can report "server not responding".
                 * We _could_ just block here now that our
                 * IOD is just a reader.
                 */
#if 1
                /* Wait with timeout... */
                events = 0;
                waitflg = READWAIT;
                timo = SEC_TO_TICK(SMB_NBTIMO);
                error = t_kspoll(nbp->nbp_tiptr, timo, waitflg, &events);
                if (!error && !events)
                        error = ETIME;
                if (error)
                        break;
                /* file mode for recv is: */
                fmode = FNDELAY; /* non-blocking */
#else
                fmode = 0; /* normal (blocking) */
#endif

                /* Get some more... */
                tm = NULL;
                error = tli_recv(nbp->nbp_tiptr, &tm, fmode);
                if (error == EAGAIN)
                        continue;
                if (error)
                        break;

                /*
                 * Normally get M_DATA messages here,
                 * but have to check for other types.
                 */
                switch (tm->b_datap->db_type) {
                case M_DATA:
                        break;
                case M_PROTO:
                case M_PCPROTO:
                        /*LINTED*/
                        pptr = (union T_primitives *)tm->b_rptr;
                        switch (pptr->type) {
                        case T_DATA_IND:
                                /* remove 1st mblk, keep the rest. */
                                im = tm->b_cont;
                                tm->b_cont = NULL;
                                freeb(tm);
                                tm = im;
                                break;
                        case T_DISCON_IND:
                                /* Peer disconnected. */
                                NBDEBUG("T_DISCON_IND: reason=%d",
                                    (int)pptr->discon_ind.DISCON_reason);
                                goto discon;
                        case T_ORDREL_IND:
                                /* Peer disconnecting. */
                                NBDEBUG("T_ORDREL_IND");
                                goto discon;
                        case T_OK_ACK:
                                switch (pptr->ok_ack.CORRECT_prim) {
                                case T_DISCON_REQ:
                                        NBDEBUG("T_OK_ACK/T_DISCON_REQ");
                                        goto discon;
                                default:
                                        NBDEBUG("T_OK_ACK/prim=%d",
                                            (int)pptr->ok_ack.CORRECT_prim);
                                        goto discon;
                                }
                        default:
                                NBDEBUG("M_PROTO/type=%d", (int)pptr->type);
                                goto discon;
                        }
                        break; /* M_PROTO, M_PCPROTO */

                default:
                        NBDEBUG("unexpected msg type=%d",
                            tm->b_datap->db_type);
                        /*FALLTHROUGH*/
discon:
                        /*
                         * The connection is no longer usable.
                         * Drop this message and disconnect.
                         *
                         * Note: nb_disconnect only does t_snddis
                         * on the first call, but does important
                         * cleanup and state change on any call.
                         */
                        freemsg(tm);
                        (void) nb_disconnect(nbp);
                        return (ENOTCONN);
                }

                /*
                 * If we have a data message, append it to
                 * the previous chunk(s) and update dlen
                 */
                if (!tm)
                        continue;
                if (*mpp == NULL) {
                        *mpp = tm;
                } else {
                        /* Append */
                        for (im = *mpp; im->b_cont; im = im->b_cont)
                                ;
                        im->b_cont = tm;
                }
                dlen += msgdsize(tm);
        }

        return (error);
}

/*
 * Send a T_DISCON_REQ (disconnect)
 */
static int
nb_snddis(struct nbpcb *nbp)
{
        TIUSER *tiptr = nbp->nbp_tiptr;
        cred_t *cr = nbp->nbp_cred;
        mblk_t *mp;
        struct T_discon_req *dreq;
        int error, mlen;

        ASSERT(MUTEX_HELD(&nbp->nbp_lock));

        if (tiptr == NULL)
                return (EBADF);

        mlen = sizeof (struct T_discon_req);
        if (!(mp = allocb_cred_wait(mlen, STR_NOSIG, &error, cr, NOPID)))
                return (error);

        mp->b_datap->db_type = M_PROTO;
        /*LINTED*/
        dreq = (struct T_discon_req *)mp->b_wptr;
        dreq->PRIM_type = T_DISCON_REQ;
        dreq->SEQ_number = -1;
        mp->b_wptr += sizeof (struct T_discon_req);

        error = tli_send(tiptr, mp, tiptr->fp->f_flag);
        /*
         * There is an OK/ACK response expected, which is
         * either handled by our receiver thread, or just
         * discarded if we're closing this endpoint.
         */

        return (error);
}

/*
 * Stuff the NetBIOS header into space already prepended.
 */
static void
nb_sethdr(mblk_t *m, uint8_t type, uint32_t len)
{
        uint32_t *p;

        len &= 0x1FFFF;
        len |= (type << 24);

        /*LINTED*/
        p = (uint32_t *)m->b_rptr;
        *p = htonl(len);
}

/*
 * Wait for up to 15 sec. for the next packet.
 * Often return ETIME and do nothing else.
 * When a packet header is available, check
 * the header and get the length, but don't
 * consume it.  No side effects here except
 * for the pullupmsg call.
 */
static int
nbssn_peekhdr(struct nbpcb *nbp, size_t *lenp,  uint8_t *rpcodep)
{
        uint32_t len, *hdr;
        int error;

        /*
         * Get the first message (fragment) if
         * we don't already have a left-over.
         */
        error = nb_getmsg_mlen(nbp, &nbp->nbp_frag, sizeof (len));
        if (error)
                return (error);

        if (!pullupmsg(nbp->nbp_frag, sizeof (len)))
                return (ENOSR);

        /*
         * Check the NetBIOS header.
         * (NOT consumed here)
         */
        /*LINTED*/
        hdr = (uint32_t *)nbp->nbp_frag->b_rptr;

        len = ntohl(*hdr);
        if ((len >> 16) & 0xFE) {
                NBDEBUG("bad nb header received 0x%x (MBZ flag set)\n", len);
                return (EPIPE);
        }
        *rpcodep = (len >> 24) & 0xFF;
        switch (*rpcodep) {
        case NB_SSN_MESSAGE:
        case NB_SSN_REQUEST:
        case NB_SSN_POSRESP:
        case NB_SSN_NEGRESP:
        case NB_SSN_RTGRESP:
        case NB_SSN_KEEPALIVE:
                break;
        default:
                NBDEBUG("bad nb header received 0x%x (bogus type)\n", len);
                return (EPIPE);
        }
        len &= 0x1ffff;
        if (len > NB_MAXPKTLEN) {
                NBDEBUG("packet too long (%d)\n", len);
                return (EFBIG);
        }
        *lenp = len;
        return (0);
}

/*
 * Receive a NetBIOS message.  This may block to wait for the entire
 * message to arrive.  The caller knows there is (or should be) a
 * message to be read.  When we receive and drop a keepalive or
 * zero-length message, return EAGAIN so the caller knows that
 * something was received.  This avoids false triggering of the
 * "server not responding" state machine.
 *
 * Calls to this are serialized at a higher level.
 */
static int
nbssn_recv(struct nbpcb *nbp, mblk_t **mpp, int *lenp,
    uint8_t *rpcodep)
{
        mblk_t *m0;
        uint8_t rpcode;
        int error;
        size_t rlen, len;

        /* We should be the only reader. */
        ASSERT(nbp->nbp_flags & NBF_RECVLOCK);

        if (nbp->nbp_tiptr == NULL)
                return (EBADF);
        if (mpp) {
                if (*mpp) {
                        NBDEBUG("*mpp not 0 - leak?");
                }
                *mpp = NULL;
        }
        m0 = NULL;

        /*
         * Get the NetBIOS header (not consumed yet)
         */
        error = nbssn_peekhdr(nbp, &len, &rpcode);
        if (error) {
                if (error != ETIME)
                        NBDEBUG("peekhdr, error=%d\n", error);
                return (error);
        }
        NBDEBUG("Have pkt, type=0x%x len=0x%x\n",
            (int)rpcode, (int)len);

        /*
         * Block here waiting for the whole packet to arrive.
         * If we get a timeout, return without side effects.
         * The data length we wait for here includes both the
         * NetBIOS header and the payload.
         */
        error = nb_getmsg_mlen(nbp, &nbp->nbp_frag, len + 4);
        if (error) {
                NBDEBUG("getmsg(body), error=%d\n", error);
                return (error);
        }

        /*
         * We now have an entire NetBIOS message.
         * Trim off the NetBIOS header and consume it.
         * Note: _peekhdr has done pullupmsg for us,
         * so we know it's safe to advance b_rptr.
         */
        m0 = nbp->nbp_frag;
        m0->b_rptr += 4;

        /*
         * There may be more data after the message
         * we're about to return, in which case we
         * split it and leave the remainder.
         */
        rlen = msgdsize(m0);
        ASSERT(rlen >= len);
        nbp->nbp_frag = NULL;
        if (rlen > len)
                nbp->nbp_frag = m_split(m0, len, 1);

        if (nbp->nbp_state != NBST_SESSION) {
                /*
                 * No session is established.
                 * Return whatever packet we got.
                 */
                goto out;
        }

        /*
         * A session is established; the only packets
         * we should see are session message and
         * keep-alive packets.  Drop anything else.
         */
        switch (rpcode) {

        case NB_SSN_KEEPALIVE:
                /*
                 * It's a keepalive.  Discard any data in it
                 * (there's not supposed to be any, but that
                 * doesn't mean some server won't send some)
                 */
                if (len)
                        NBDEBUG("Keepalive with data %d\n", (int)len);
                error = EAGAIN;
                break;

        case NB_SSN_MESSAGE:
                /*
                 * Session message.  Does it have any data?
                 */
                if (len == 0) {
                        /*
                         * No data - treat as keepalive (drop).
                         */
                        error = EAGAIN;
                        break;
                }
                /*
                 * Yes, has data.  Return it.
                 */
                error = 0;
                break;

        default:
                /*
                 * Drop anything else.
                 */
                NBDEBUG("non-session packet %x\n", rpcode);
                error = EAGAIN;
                break;
        }

out:
        if (error) {
                if (m0)
                        m_freem(m0);
                return (error);
        }
        if (mpp)
                *mpp = m0;
        else
                m_freem(m0);
        *lenp = (int)len;
        *rpcodep = rpcode;
        return (0);
}

/*
 * SMB transport interface
 *
 * This is called only by the thread creating this endpoint,
 * so we're single-threaded here.
 */
static int
smb_nbst_create(struct smb_vc *vcp, cred_t *cr)
{
        TIUSER *tiptr = NULL;
        struct nbpcb *nbp = NULL;
        dev_t dev;
        int rc;
        ushort_t fmode;

        switch (vcp->vc_srvaddr.sa.sa_family) {
        case AF_INET:
                dev = nsmb_dev_tcp;
                break;
        case AF_INET6:
                dev = nsmb_dev_tcp6;
                break;
        default:
                return (EAFNOSUPPORT);
        }

        fmode = FREAD|FWRITE;
        rc = t_kopen(NULL, dev, fmode, &tiptr, cr);
        if (rc != 0) {
                cmn_err(CE_NOTE, "t_kopen failed, rc=%d", rc);
                return (rc);
        }
        ASSERT(tiptr != NULL);

        nbp = kmem_zalloc(sizeof (struct nbpcb), KM_SLEEP);

        nbp->nbp_timo.tv_sec = SMB_NBTIMO;
        nbp->nbp_state = NBST_IDLE;
        nbp->nbp_vc = vcp;
        nbp->nbp_tiptr = tiptr;
        nbp->nbp_fmode = fmode;
        nbp->nbp_cred = cr;
        crhold(cr);
        mutex_init(&nbp->nbp_lock, NULL, MUTEX_DRIVER, NULL);

        vcp->vc_tdata = nbp;

        return (0);
}

/*
 * destroy a transport endpoint
 *
 * This is called only by the thread with the last reference
 * to this endpoint, so we're single-threaded here.
 */
static int
smb_nbst_done(struct smb_vc *vcp)
{
        struct nbpcb *nbp = vcp->vc_tdata;

        if (nbp == NULL)
                return (ENOTCONN);
        vcp->vc_tdata = NULL;

        /*
         * Don't really need to disconnect here,
         * because the close following will do it.
         * But it's harmless.
         */
        if (nbp->nbp_flags & NBF_CONNECTED)
                (void) nb_disconnect(nbp);
        if (nbp->nbp_tiptr)
                (void) t_kclose(nbp->nbp_tiptr, 0);
        if (nbp->nbp_laddr)
                smb_free_sockaddr((struct sockaddr *)nbp->nbp_laddr);
        if (nbp->nbp_paddr)
                smb_free_sockaddr((struct sockaddr *)nbp->nbp_paddr);
        if (nbp->nbp_cred)
                crfree(nbp->nbp_cred);
        mutex_destroy(&nbp->nbp_lock);
        kmem_free(nbp, sizeof (*nbp));
        return (0);
}

static int
smb_nbst_bind(struct smb_vc *vcp, struct sockaddr *sap)
{
        struct nbpcb *nbp = vcp->vc_tdata;
        TIUSER *tiptr = nbp->nbp_tiptr;
        int err;

        /* Only default bind supported. */
        if (sap != NULL)
                return (ENOTSUP);

        err = t_kbind(tiptr, NULL, NULL);

        return (err);
}

static int
smb_nbst_unbind(struct smb_vc *vcp)
{
        struct nbpcb *nbp = vcp->vc_tdata;
        TIUSER *tiptr = nbp->nbp_tiptr;
        int err;

        err = t_kunbind(tiptr);

        return (err);
}

static int
smb_nbst_connect(struct smb_vc *vcp, struct sockaddr *sap)
{
        struct t_call   call;
        struct nbpcb    *nbp = vcp->vc_tdata;
        TIUSER          *tiptr = nbp->nbp_tiptr;
        int alen, err;

        /* Need the address length */
        switch (sap->sa_family) {
        case AF_INET:
                alen = sizeof (struct sockaddr_in);
                break;
        case AF_INET6:
                alen = sizeof (struct sockaddr_in6);
                break;
        default:
                return (EAFNOSUPPORT);
        }

        /* sockaddr goes in the "addr" netbuf */
        bzero(&call, sizeof (call));
        call.addr.buf = (char *)sap;
        call.addr.len = alen;
        call.addr.maxlen = alen;

        err = t_kconnect(tiptr, &call, NULL);
        if (err != 0)
                return (err);

        mutex_enter(&nbp->nbp_lock);

        nbp->nbp_flags |= NBF_CONNECTED;
        nbp->nbp_state = NBST_SESSION;

        mutex_exit(&nbp->nbp_lock);

        return (0);
}

static int
smb_nbst_disconnect(struct smb_vc *vcp)
{
        struct nbpcb *nbp = vcp->vc_tdata;

        if (nbp == NULL)
                return (ENOTCONN);

        return (nb_disconnect(nbp));
}

static int
nb_disconnect(struct nbpcb *nbp)
{
        int err = 0;

        mutex_enter(&nbp->nbp_lock);

        if ((nbp->nbp_flags & NBF_CONNECTED) != 0) {
                nbp->nbp_flags &= ~NBF_CONNECTED;
                err = nb_snddis(nbp);
        }

        mutex_exit(&nbp->nbp_lock);
        return (err);
}

/*
 * Add the NetBIOS session header and send.
 *
 * Calls to this are serialized at a higher level.
 */
static int
nbssn_send(struct nbpcb *nbp, mblk_t *m)
{
        ptrdiff_t diff;
        uint32_t mlen;
        int error;

        /* We should be the only sender. */
        ASSERT(nbp->nbp_flags & NBF_SENDLOCK);

        if (nbp->nbp_tiptr == NULL) {
                error = EBADF;
                goto errout;
        }

        /*
         * Get the message length, which
         * does NOT include the NetBIOS header
         */
        mlen = msgdsize(m);

        /*
         * Normally, mb_init() will have left space
         * for us to prepend the NetBIOS header in
         * the data block of the first mblk.
         * However, we have to check in case other
         * code did not leave this space, or if the
         * message is from dupmsg (db_ref > 1)
         *
         * If don't find room in the first data block,
         * we have to allocb a new message and link it
         * on the front of the chain.  We try not to
         * do this becuase it's less efficient.  Also,
         * some network drivers will apparently send
         * each mblk in the chain as separate frames.
         * (That's arguably a driver bug.)
         *
         * Not bothering with allocb_cred_wait below
         * because the message we're prepending to
         * should already have a db_credp.
         */

        diff = MBLKHEAD(m);
        if (diff == 4 && DB_REF(m) == 1) {
                /* We can use the first dblk. */
                m->b_rptr -= 4;
        } else {
                /* Link a new mblk on the head. */
                mblk_t *m0;

                /* M_PREPEND */
                m0 = allocb_wait(4, BPRI_LO, STR_NOSIG, &error);
                if (m0 == NULL)
                        goto errout;

                m0->b_wptr += 4;
                m0->b_cont = m;
                m = m0;
        }

        nb_sethdr(m, NB_SSN_MESSAGE, mlen);
        error = tli_send(nbp->nbp_tiptr, m, 0);
        return (error);

errout:
        if (m != NULL)
                m_freem(m);
        return (error);
}

/*
 * Always consume the message.
 * (On error too!)
 */
static int
smb_nbst_send(struct smb_vc *vcp, mblk_t *m)
{
        struct nbpcb *nbp = vcp->vc_tdata;
        int err;

        mutex_enter(&nbp->nbp_lock);
        if ((nbp->nbp_flags & NBF_CONNECTED) == 0) {
                err = ENOTCONN;
                goto out;
        }
        if (nbp->nbp_flags & NBF_SENDLOCK) {
                NBDEBUG("multiple smb_nbst_send!\n");
                err = EWOULDBLOCK;
                goto out;
        }
        nbp->nbp_flags |= NBF_SENDLOCK;
        mutex_exit(&nbp->nbp_lock);

        err = nbssn_send(nbp, m);
        m = NULL; /* nbssn_send always consumes this */

        mutex_enter(&nbp->nbp_lock);
        nbp->nbp_flags &= ~NBF_SENDLOCK;
        if (nbp->nbp_flags & NBF_LOCKWAIT) {
                nbp->nbp_flags &= ~NBF_LOCKWAIT;
                cv_broadcast(&nbp->nbp_cv);
        }
out:
        mutex_exit(&nbp->nbp_lock);
        if (m != NULL)
                m_freem(m);
        return (err);
}

static int
smb_nbst_recv(struct smb_vc *vcp, mblk_t **mpp)
{
        struct nbpcb *nbp = vcp->vc_tdata;
        uint8_t rpcode;
        int err, rplen;

        mutex_enter(&nbp->nbp_lock);
        if ((nbp->nbp_flags & NBF_CONNECTED) == 0) {
                err = ENOTCONN;
                goto out;
        }
        if (nbp->nbp_flags & NBF_RECVLOCK) {
                NBDEBUG("multiple smb_nbst_recv!\n");
                err = EWOULDBLOCK;
                goto out;
        }
        nbp->nbp_flags |= NBF_RECVLOCK;
        mutex_exit(&nbp->nbp_lock);

        err = nbssn_recv(nbp, mpp, &rplen, &rpcode);

        mutex_enter(&nbp->nbp_lock);
        nbp->nbp_flags &= ~NBF_RECVLOCK;
        if (nbp->nbp_flags & NBF_LOCKWAIT) {
                nbp->nbp_flags &= ~NBF_LOCKWAIT;
                cv_broadcast(&nbp->nbp_cv);
        }
out:
        mutex_exit(&nbp->nbp_lock);
        return (err);
}

/*
 * Wait for up to "ticks" clock ticks for input on vcp.
 * Returns zero if input is available, otherwise ETIME
 * indicating time expired, or other error codes.
 */
/*ARGSUSED*/
static int
smb_nbst_poll(struct smb_vc *vcp, int ticks)
{
        return (ENOTSUP);
}

/*ARGSUSED*/
static int
smb_nbst_getparam(struct smb_vc *vcp, int param, void *data)
{
        return (EINVAL);
}

static int
smb_nbst_setparam(struct smb_vc *vcp, int param, void *data)
{
        struct t_optmgmt oreq, ores;
        struct {
                struct T_opthdr oh;
                int ival;
        } opts;
        struct nbpcb *nbp = vcp->vc_tdata;
        int level, name, err;

        switch (param) {
        case SMBTP_TCP_NODELAY:
                level = IPPROTO_TCP;
                name = TCP_NODELAY;
                break;

        case SMBTP_TCP_CON_TMO: /* int mSec */
                level = IPPROTO_TCP;
                name = TCP_CONN_ABORT_THRESHOLD;
                break;

        case SMBTP_KEEPALIVE:   // SO_KEEPALIVE
        case SMBTP_SNDBUF:      // SO_SNDBUF
        case SMBTP_RCVBUF:      // SO_RCVBUF
        case SMBTP_RCVTIMEO:    // SO_RCVTIMEO
                level = SOL_SOCKET;
                name = param;
                break;

        default:
                return (EINVAL);
        }

        /* opt header */
        opts.oh.len = sizeof (opts);
        opts.oh.level = level;
        opts.oh.name = name;
        opts.oh.status = 0;
        opts.ival = *(int *)data;

        oreq.flags = T_NEGOTIATE;
        oreq.opt.buf = (void *)&opts;
        oreq.opt.len = sizeof (opts);
        oreq.opt.maxlen = oreq.opt.len;

        ores.flags = 0;
        ores.opt.buf = NULL;
        ores.opt.len = 0;
        ores.opt.maxlen = 0;

        err = t_koptmgmt(nbp->nbp_tiptr, &oreq, &ores);
        if (err != 0) {
                cmn_err(CE_NOTE, "t_opgmgnt, err = %d", err);
                return (EPROTO);
        }

        if ((ores.flags & T_SUCCESS) == 0) {
                cmn_err(CE_NOTE, "smb_nbst_setparam: "
                    "flags 0x%x, status 0x%x",
                    (int)ores.flags, (int)opts.oh.status);
                return (EPROTO);
        }

        return (0);
}

/*
 * Check for fatal errors
 */
/*ARGSUSED*/
static int
smb_nbst_fatal(struct smb_vc *vcp, int error)
{
        switch (error) {
        case ENOTCONN:
        case ENETRESET:
        case ECONNABORTED:
        case EPIPE:
                return (1);
        }
        return (0);
}


struct smb_tran_desc smb_tran_nbtcp_desc = {
        SMBT_NBTCP,
        smb_nbst_create,
        smb_nbst_done,
        smb_nbst_bind,
        smb_nbst_unbind,
        smb_nbst_connect,
        smb_nbst_disconnect,
        smb_nbst_send,
        smb_nbst_recv,
        smb_nbst_poll,
        smb_nbst_getparam,
        smb_nbst_setparam,
        smb_nbst_fatal,
        {NULL, NULL}
};