/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2021 Tintri by DDN, Inc. All rights reserved.
 */

/*
 * Shim to implement ksocket_sendmblk on top of ksocket_sendmsg
 */

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/cred.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <sys/ksocket.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/debug.h>
#include <sys/kmem.h>
#include <limits.h>
#include <unistd.h>
#include <errno.h>
#include <umem.h>

int
ksocket_sendmblk(ksocket_t ks, struct nmsghdr *msg, int flags,
    mblk_t **mpp, cred_t *cr)
{
        struct msghdr   tmsg;
        mblk_t          *m;
        iovec_t         *iov = NULL;
        size_t          iov_sz = 0;
        size_t          tlen, sent;
        int             i, nseg;
        int             rc;

        /*
         * Setup the IOV.  First, count the number of IOV segments
         * and get the total length.
         */
        nseg = 0;
        tlen = 0;
        m = *mpp;
        while (m != NULL) {
                nseg++;
                tlen += MBLKL(m);
                m = m->b_cont;
        }
        ASSERT(tlen > 0);
        if (tlen == 0) {
                rc = 0;
                goto out;
        }

        iov_sz = nseg * sizeof (iovec_t);
        iov = kmem_alloc(iov_sz, KM_SLEEP);

        /*
         * Build the iov list
         */
        i = 0;
        m = *mpp;
        while (m != NULL) {
                iov[i].iov_base = (void *) m->b_rptr;
                iov[i++].iov_len = MBLKL(m);
                m = m->b_cont;
        }
        ASSERT3S(i, ==, nseg);

        bzero(&tmsg, sizeof (tmsg));
        tmsg.msg_iov = iov;
        tmsg.msg_iovlen = nseg;
        while (tlen > 0) {
                sent = 0;
                rc = ksocket_sendmsg(ks, &tmsg, 0, &sent, CRED());
                if (rc != 0)
                        break;
                tlen -= sent;
        }

out:
        if (iov != NULL)
                kmem_free(iov, iov_sz);
        if (*mpp != NULL) {
                freemsg(*mpp);
                *mpp = NULL;
        }

        return (rc);
}