/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2017 RackTop Systems.
 */

#include <rpc/types.h>
#include <rpc/xdr.h>
#include <sys/types.h>
#include <sys/sdt.h>
#include <rpc/auth.h>
#include <rpc/rpc_rdma.h>

struct private {
        int     min_chunk;
        uint_t  flags;                  /* controls setting for rdma xdr */
        int     num_chunk;
        caddr_t inline_buf;             /* temporary buffer for xdr inlining */
        int     inline_len;             /* inline buffer length */
        uint_t  xp_reply_chunk_len;
        uint_t  xp_reply_chunk_len_alt;
};

/* ARGSUSED */
static bool_t
x_putint32_t(XDR *xdrs, int32_t *ip)
{
        xdrs->x_handy += BYTES_PER_XDR_UNIT;
        return (TRUE);
}

/* ARGSUSED */
static bool_t
x_putbytes(XDR *xdrs, char *bp, int len)
{
        struct private *xdrp = (struct private *)xdrs->x_private;

        /*
         * min_chunk = 0, means that the stream of bytes, to estimate size of,
         * contains no chunks to seperate out. See xdrrdma_putbytes()
         */
        if (len < xdrp->min_chunk || !(xdrp->flags & XDR_RDMA_CHUNK)) {
                xdrs->x_handy += len;
                return (TRUE);
        }
        /*
         * Chunk item. No impact on xdr size.
         */
        xdrp->num_chunk++;

        return (TRUE);
}

static uint_t
x_getpostn(XDR *xdrs)
{
        return (xdrs->x_handy);
}

/* ARGSUSED */
static bool_t
x_setpostn(XDR *xdrs, uint_t pos)
{
        /* This is not allowed */
        return (FALSE);
}

/* ARGSUSED */
static bool_t
x_control(XDR *xdrs, int request, void *info)
{
        int32_t *int32p;
        uint_t in_flags;
        rdma_chunkinfo_t *rcip = NULL;
        rdma_chunkinfo_lengths_t *rcilp = NULL;
        struct private *xdrp = (struct private *)xdrs->x_private;

        switch (request) {
        case XDR_RDMA_SET_FLAGS:
                /*
                 * Set the flags provided in the *info in xp_flags for rdma xdr
                 * stream control.
                 */
                int32p = (int32_t *)info;
                in_flags = (uint_t)(*int32p);

                xdrp->flags = in_flags;
                return (TRUE);

        case XDR_RDMA_GET_FLAGS:
                /*
                 * Get the flags provided in xp_flags return through *info
                 */
                int32p = (int32_t *)info;

                *int32p = (int32_t)xdrp->flags;
                return (TRUE);

        case XDR_RDMA_GET_CHUNK_LEN:
                rcilp = (rdma_chunkinfo_lengths_t *)info;
                rcilp->rcil_len = xdrp->xp_reply_chunk_len;
                rcilp->rcil_len_alt = xdrp->xp_reply_chunk_len_alt;

                return (TRUE);

        case XDR_RDMA_ADD_CHUNK:
                rcip = (rdma_chunkinfo_t *)info;

                switch (rcip->rci_type) {
                case RCI_WRITE_UIO_CHUNK:
                        xdrp->xp_reply_chunk_len_alt += rcip->rci_len;
                        break;

                case RCI_WRITE_ADDR_CHUNK:
                        xdrp->xp_reply_chunk_len_alt += rcip->rci_len;
                        break;

                case RCI_REPLY_CHUNK:
                        xdrp->xp_reply_chunk_len += rcip->rci_len;
                        break;
                }
                return (TRUE);

        default:
                return (FALSE);
        }
}

/* ARGSUSED */
static rpc_inline_t *
x_inline(XDR *xdrs, int len)
{
        struct private *xdrp = (struct private *)xdrs->x_private;

        if (len == 0) {
                return (NULL);
        }
        if (xdrs->x_op != XDR_ENCODE) {
                return (NULL);
        }
        if (len >= xdrp->min_chunk) {
                return (NULL);
        }
        if (len <= xdrp->inline_len) {
                /* inline_buf was already allocated, just reuse it */
                xdrs->x_handy += len;
                return ((rpc_inline_t *)xdrp->inline_buf);
        } else {
                /* Free the earlier space and allocate new area */
                if (xdrp->inline_buf)
                        mem_free(xdrp->inline_buf, xdrp->inline_len);
                if ((xdrp->inline_buf = (caddr_t)mem_alloc(len)) == NULL) {
                        xdrp->inline_len = 0;
                        return (NULL);
                }
                xdrp->inline_len = len;
                xdrs->x_handy += len;
                return ((rpc_inline_t *)xdrp->inline_buf);
        }
}

static int
harmless()
{
        /* Always return FALSE/NULL, as the case may be */
        return (0);
}

static void
x_destroy(XDR *xdrs)
{
        struct private *xdrp = (struct private *)xdrs->x_private;

        xdrs->x_handy = 0;
        if (xdrp) {
                if (xdrp->inline_buf)
                        mem_free(xdrp->inline_buf, xdrp->inline_len);
                mem_free(xdrp, sizeof (struct private));
                xdrs->x_private = NULL;
        }
        xdrs->x_base = 0;
}

static bool_t
xdrrdma_common(XDR *xdrs, int min_chunk)
{
        struct private *xdrp;

        xdrs->x_ops = xdrrdma_xops();
        xdrs->x_op = XDR_ENCODE;
        xdrs->x_handy = 0;
        xdrs->x_base = NULL;
        xdrs->x_private = kmem_zalloc(sizeof (struct private), KM_SLEEP);
        xdrp = (struct private *)xdrs->x_private;
        xdrp->min_chunk = min_chunk;
        xdrp->flags = 0;
        if (xdrp->min_chunk != 0)
                xdrp->flags |= XDR_RDMA_CHUNK;

        xdrp->xp_reply_chunk_len = 0;
        xdrp->xp_reply_chunk_len_alt = 0;

        return (TRUE);
}

unsigned int
xdrrdma_sizeof(xdrproc_t func, void *data, int min_chunk,
    uint_t *reply_size, uint_t *reply_size_alt)
{
        XDR x;
        struct xdr_ops ops;
        bool_t stat;
        struct private *xdrp;

        x.x_ops = &ops;
        (void) xdrrdma_common(&x, min_chunk);

        stat = func(&x, data);
        xdrp = (struct private *)x.x_private;
        if (xdrp) {
                if (reply_size != NULL)
                        *reply_size = xdrp->xp_reply_chunk_len;
                if (reply_size_alt != NULL)
                        *reply_size_alt = xdrp->xp_reply_chunk_len_alt;
                if (xdrp->inline_buf)
                        mem_free(xdrp->inline_buf, xdrp->inline_len);
                mem_free(xdrp, sizeof (struct private));
        }
        return (stat == TRUE ? (unsigned int)x.x_handy: 0);
}

unsigned int
xdrrdma_authsize(AUTH *auth, struct cred *cred, int min_chunk)
{
        XDR x;
        struct xdr_ops ops;
        bool_t stat;
        struct private *xdrp;

        x.x_ops = &ops;
        (void) xdrrdma_common(&x, min_chunk);

        stat = AUTH_MARSHALL(auth, &x, cred);
        xdrp = (struct private *)x.x_private;
        if (xdrp) {
                if (xdrp->inline_buf)
                        mem_free(xdrp->inline_buf, xdrp->inline_len);
                mem_free(xdrp, sizeof (struct private));
        }
        return (stat == TRUE ? (unsigned int)x.x_handy: 0);
}

struct xdr_ops *
xdrrdma_xops(void)
{
        static struct xdr_ops ops;

        /* to stop ANSI-C compiler from complaining */
        typedef  bool_t (* dummyfunc1)(XDR *, caddr_t, int);
#if defined(_LP64) || defined(_KERNEL)
        typedef  bool_t (* dummyfunc2)(XDR *, int32_t *);
#endif

        ops.x_putbytes = x_putbytes;
        ops.x_inline = x_inline;
        ops.x_getpostn = x_getpostn;
        ops.x_setpostn = x_setpostn;
        ops.x_destroy = x_destroy;
        ops.x_control = x_control;

#if defined(_LP64) || defined(_KERNEL)
        ops.x_getint32 = (dummyfunc2)harmless;
        ops.x_putint32 = x_putint32_t;
#endif

        /* the other harmless ones */
        ops.x_getbytes = (dummyfunc1)harmless;

        return (&ops);
}