/*
 * 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) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * xdr.c, generic XDR routines implementation.
 * These are the "generic" xdr routines used to serialize and de-serialize
 * most common data items.  See xdr.h for more info on the interface to
 * xdr.
 */

#include <sys/param.h>
#include <sys/cmn_err.h>
#include <sys/types.h>
#include <sys/systm.h>

#include <rpc/types.h>
#include <rpc/xdr.h>
#include <sys/isa_defs.h>

#pragma weak xdr_int32_t = xdr_int
#pragma weak xdr_uint32_t = xdr_u_int
#pragma weak xdr_int64_t = xdr_longlong_t
#pragma weak xdr_uint64_t = xdr_u_longlong_t

#if !defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
#error "Exactly one of _BIG_ENDIAN or _LITTLE_ENDIAN must be defined"
#elif defined(_BIG_ENDIAN) && defined(_LITTLE_ENDIAN)
#error "Only one of _BIG_ENDIAN or _LITTLE_ENDIAN may be defined"
#endif

/*
 * constants specific to the xdr "protocol"
 */
#define XDR_FALSE       ((int32_t)0)
#define XDR_TRUE        ((int32_t)1)
#define LASTUNSIGNED    ((uint_t)0-1)

/*
 * for unit alignment
 */
static char xdr_zero[BYTES_PER_XDR_UNIT] = { 0, 0, 0, 0 };

/*
 * Free a data structure using XDR
 * Not a filter, but a convenient utility nonetheless
 */
void
xdr_free(xdrproc_t proc, char *objp)
{
        XDR x;

        x.x_op = XDR_FREE;
        (void) (*proc)(&x, objp);
}

/*
 * XDR nothing
 */
bool_t
xdr_void(void)
{
        return (TRUE);
}

/*
 * XDR integers
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_int
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
bool_t
xdr_int(XDR *xdrs, int *ip)
{
        if (xdrs->x_op == XDR_ENCODE)
                return (XDR_PUTINT32(xdrs, ip));

        if (xdrs->x_op == XDR_DECODE)
                return (XDR_GETINT32(xdrs, ip));

        if (xdrs->x_op == XDR_FREE)
                return (TRUE);

        return (FALSE);
}

/*
 * XDR unsigned integers
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_u_int
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
bool_t
xdr_u_int(XDR *xdrs, uint_t *up)
{
        if (xdrs->x_op == XDR_ENCODE)
                return (XDR_PUTINT32(xdrs, (int32_t *)up));

        if (xdrs->x_op == XDR_DECODE)
                return (XDR_GETINT32(xdrs, (int32_t *)up));

        if (xdrs->x_op == XDR_FREE)
                return (TRUE);

        return (FALSE);
}


#if defined(_ILP32)
/*
 * xdr_long and xdr_u_long for binary compatability on ILP32 kernels.
 *
 * No prototypes since new code should not be using these interfaces.
 */
bool_t
xdr_long(XDR *xdrs, long *ip)
{
        return (xdr_int(xdrs, (int *)ip));
}

bool_t
xdr_u_long(XDR *xdrs, unsigned long *up)
{
        return (xdr_u_int(xdrs, (uint_t *)up));
}
#endif /* _ILP32 */


/*
 * XDR long long integers
 */
bool_t
xdr_longlong_t(XDR *xdrs, longlong_t *hp)
{
        if (xdrs->x_op == XDR_ENCODE) {
#if defined(_LITTLE_ENDIAN)
                if (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
                    BYTES_PER_XDR_UNIT)) == TRUE) {
                        return (XDR_PUTINT32(xdrs, (int32_t *)hp));
                }
#elif defined(_BIG_ENDIAN)
                if (XDR_PUTINT32(xdrs, (int32_t *)hp) == TRUE) {
                        return (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
                            BYTES_PER_XDR_UNIT)));
                }
#endif
                return (FALSE);

        }
        if (xdrs->x_op == XDR_DECODE) {
#if defined(_LITTLE_ENDIAN)
                if (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
                    BYTES_PER_XDR_UNIT)) == TRUE) {
                        return (XDR_GETINT32(xdrs, (int32_t *)hp));
                }
#elif defined(_BIG_ENDIAN)
                if (XDR_GETINT32(xdrs, (int32_t *)hp) == TRUE) {
                        return (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
                            BYTES_PER_XDR_UNIT)));
                }
#endif
                return (FALSE);
        }
        return (TRUE);
}

/*
 * XDR unsigned long long integers
 */
bool_t
xdr_u_longlong_t(XDR *xdrs, u_longlong_t *hp)
{

        if (xdrs->x_op == XDR_ENCODE) {
#if defined(_LITTLE_ENDIAN)
                if (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
                    BYTES_PER_XDR_UNIT)) == TRUE) {
                        return (XDR_PUTINT32(xdrs, (int32_t *)hp));
                }
#elif defined(_BIG_ENDIAN)
                if (XDR_PUTINT32(xdrs, (int32_t *)hp) == TRUE) {
                        return (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
                            BYTES_PER_XDR_UNIT)));
                }
#endif
                return (FALSE);

        }
        if (xdrs->x_op == XDR_DECODE) {
#if defined(_LITTLE_ENDIAN)
                if (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
                    BYTES_PER_XDR_UNIT)) == TRUE) {
                        return (XDR_GETINT32(xdrs, (int32_t *)hp));
                }
#elif defined(_BIG_ENDIAN)
                if (XDR_GETINT32(xdrs, (int32_t *)hp) == TRUE) {
                        return (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
                            BYTES_PER_XDR_UNIT)));
                }
#endif
                return (FALSE);
        }
        return (TRUE);
}

/*
 * XDR short integers
 */
bool_t
xdr_short(XDR *xdrs, short *sp)
{
        int32_t l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (int32_t)*sp;
                return (XDR_PUTINT32(xdrs, &l));

        case XDR_DECODE:
                if (!XDR_GETINT32(xdrs, &l))
                        return (FALSE);
                *sp = (short)l;
                return (TRUE);

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}

/*
 * XDR unsigned short integers
 */
bool_t
xdr_u_short(XDR *xdrs, ushort_t *usp)
{
        uint32_t l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (uint32_t)*usp;
                return (XDR_PUTINT32(xdrs, (int32_t *)&l));

        case XDR_DECODE:
                if (!XDR_GETINT32(xdrs, (int32_t *)&l)) {
                        return (FALSE);
                }
                *usp = (ushort_t)l;
                return (TRUE);

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}


/*
 * XDR a char
 */
bool_t
xdr_char(XDR *xdrs, char *cp)
{
        int i;

        i = (*cp);
        if (!xdr_int(xdrs, &i)) {
                return (FALSE);
        }
        *cp = (char)i;
        return (TRUE);
}

/*
 * XDR an unsigned char
 */
bool_t
xdr_u_char(XDR *xdrs, uchar_t *cp)
{
        int i;

        switch (xdrs->x_op) {
        case XDR_ENCODE:
                i = (*cp);
                return (XDR_PUTINT32(xdrs, &i));
        case XDR_DECODE:
                if (!XDR_GETINT32(xdrs, &i))
                        return (FALSE);
                *cp = (uchar_t)i;
                return (TRUE);
        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}

/*
 * XDR booleans
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_bool
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
bool_t
xdr_bool(XDR *xdrs, bool_t *bp)
{
        int32_t i32b;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                i32b = *bp ? XDR_TRUE : XDR_FALSE;
                return (XDR_PUTINT32(xdrs, &i32b));

        case XDR_DECODE:
                if (!XDR_GETINT32(xdrs, &i32b)) {
                        return (FALSE);
                }
                *bp = (i32b == XDR_FALSE) ? FALSE : TRUE;
                return (TRUE);

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}

/*
 * XDR enumerations
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_enum
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
#ifndef lint
enum sizecheck { SIZEVAL } sizecheckvar;        /* used to find the size of */
                                                /* an enum */
#endif
bool_t
xdr_enum(XDR *xdrs, enum_t *ep)
{
#ifndef lint
        /*
         * enums are treated as ints
         */
        if (sizeof (sizecheckvar) == sizeof (int32_t)) {
                return (xdr_int(xdrs, (int32_t *)ep));
        } else if (sizeof (sizecheckvar) == sizeof (short)) {
                return (xdr_short(xdrs, (short *)ep));
        } else {
                return (FALSE);
        }
#else
        (void) (xdr_short(xdrs, (short *)ep));
        return (xdr_int(xdrs, (int32_t *)ep));
#endif
}

/*
 * XDR opaque data
 * Allows the specification of a fixed size sequence of opaque bytes.
 * cp points to the opaque object and cnt gives the byte length.
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_opaque
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
bool_t
xdr_opaque(XDR *xdrs, caddr_t cp, const uint_t cnt)
{
        uint_t rndup;
        static char crud[BYTES_PER_XDR_UNIT];

        /*
         * if no data we are done
         */
        if (cnt == 0)
                return (TRUE);

        /*
         * round byte count to full xdr units
         */
        rndup = cnt % BYTES_PER_XDR_UNIT;
        if (rndup != 0)
                rndup = BYTES_PER_XDR_UNIT - rndup;

        if (xdrs->x_op == XDR_DECODE) {
                if (!XDR_GETBYTES(xdrs, cp, cnt)) {
                        return (FALSE);
                }
                if (rndup == 0)
                        return (TRUE);
                return (XDR_GETBYTES(xdrs, (caddr_t)crud, rndup));
        }

        if (xdrs->x_op == XDR_ENCODE) {
                if (!XDR_PUTBYTES(xdrs, cp, cnt)) {
                        return (FALSE);
                }
                if (rndup == 0)
                        return (TRUE);
                return (XDR_PUTBYTES(xdrs, xdr_zero, rndup));
        }

        if (xdrs->x_op == XDR_FREE)
                return (TRUE);

        return (FALSE);
}

/*
 * XDR counted bytes
 * *cpp is a pointer to the bytes, *sizep is the count.
 * If *cpp is NULL maxsize bytes are allocated
 *
 * PSARC 2003/523 Contract Private Interface
 * xdr_bytes
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2003-523@sun.com
 */
bool_t
xdr_bytes(XDR *xdrs, char **cpp, uint_t *sizep, const uint_t maxsize)
{
        char *sp = *cpp;  /* sp is the actual string pointer */
        uint_t nodesize;

        /*
         * first deal with the length since xdr bytes are counted
         */
        if (!xdr_u_int(xdrs, sizep)) {
                return (FALSE);
        }
        nodesize = *sizep;
        if ((nodesize > maxsize) && (xdrs->x_op != XDR_FREE)) {
                return (FALSE);
        }

        /*
         * now deal with the actual bytes
         */
        switch (xdrs->x_op) {
        case XDR_DECODE:
                if (nodesize == 0)
                        return (TRUE);
                if (sp == NULL)
                        *cpp = sp = (char *)mem_alloc(nodesize);
                /* FALLTHROUGH */

        case XDR_ENCODE:
                return (xdr_opaque(xdrs, sp, nodesize));

        case XDR_FREE:
                if (sp != NULL) {
                        mem_free(sp, nodesize);
                        *cpp = NULL;
                }
                return (TRUE);
        }
        return (FALSE);
}

/*
 * Implemented here due to commonality of the object.
 */
bool_t
xdr_netobj(XDR *xdrs, struct netobj *np)
{
        return (xdr_bytes(xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ));
}

/*
 * XDR a descriminated union
 * Support routine for discriminated unions.
 * You create an array of xdrdiscrim structures, terminated with
 * an entry with a null procedure pointer.  The routine gets
 * the discriminant value and then searches the array of xdrdiscrims
 * looking for that value.  It calls the procedure given in the xdrdiscrim
 * to handle the discriminant.  If there is no specific routine a default
 * routine may be called.
 * If there is no specific or default routine an error is returned.
 */
bool_t
xdr_union(XDR *xdrs, enum_t *dscmp, char *unp,
        const struct xdr_discrim *choices, const xdrproc_t dfault)
{
        enum_t dscm;

        /*
         * we deal with the discriminator;  it's an enum
         */
        if (!xdr_enum(xdrs, dscmp)) {
                return (FALSE);
        }
        dscm = *dscmp;

        /*
         * search choices for a value that matches the discriminator.
         * if we find one, execute the xdr routine for that value.
         */
        for (; choices->proc != NULL_xdrproc_t; choices++) {
                if (choices->value == dscm)
                        return ((*(choices->proc))(xdrs, unp, LASTUNSIGNED));
        }

        /*
         * no match - execute the default xdr routine if there is one
         */
        return ((dfault == NULL_xdrproc_t) ? FALSE :
            (*dfault)(xdrs, unp, LASTUNSIGNED));
}


/*
 * Non-portable xdr primitives.
 * Care should be taken when moving these routines to new architectures.
 */


/*
 * XDR null terminated ASCII strings
 * xdr_string deals with "C strings" - arrays of bytes that are
 * terminated by a NULL character.  The parameter cpp references a
 * pointer to storage; If the pointer is null, then the necessary
 * storage is allocated.  The last parameter is the max allowed length
 * of the string as specified by a protocol.
 */
bool_t
xdr_string(XDR *xdrs, char **cpp, const uint_t maxsize)
{
        char *sp = *cpp;  /* sp is the actual string pointer */
        uint_t size;
        uint_t nodesize;

        /*
         * first deal with the length since xdr strings are counted-strings
         */
        switch (xdrs->x_op) {
        case XDR_FREE:
                if (sp == NULL)
                        return (TRUE);  /* already free */
                /* FALLTHROUGH */
        case XDR_ENCODE:
                size = (sp != NULL) ? (uint_t)strlen(sp) : 0;
                break;
        case XDR_DECODE:
                break;
        }
        if (!xdr_u_int(xdrs, &size)) {
                return (FALSE);
        }
        if (size > maxsize) {
                return (FALSE);
        }
        nodesize = size + 1;

        /*
         * now deal with the actual bytes
         */
        switch (xdrs->x_op) {
        case XDR_DECODE:
                if (nodesize == 0)
                        return (TRUE);
                if (sp == NULL)
                        sp = (char *)mem_alloc(nodesize);
                sp[size] = 0;
                if (!xdr_opaque(xdrs, sp, size)) {
                        /*
                         * free up memory if allocated here
                         */
                        if (*cpp == NULL) {
                                mem_free(sp, nodesize);
                        }
                        return (FALSE);
                }
                if (strlen(sp) != size) {
                        if (*cpp == NULL) {
                                mem_free(sp, nodesize);
                        }
                        return (FALSE);
                }
                *cpp = sp;
                return (TRUE);

        case XDR_ENCODE:
                return (xdr_opaque(xdrs, sp, size));

        case XDR_FREE:
                mem_free(sp, nodesize);
                *cpp = NULL;
                return (TRUE);
        }
        return (FALSE);
}

/*
 * xdr_vector():
 *
 * XDR a fixed length array. Unlike variable-length arrays, the storage
 * of fixed length arrays is static and unfreeable.
 * > basep: base of the array
 * > size: size of the array
 * > elemsize: size of each element
 * > xdr_elem: routine to XDR each element
 */
bool_t
xdr_vector(XDR *xdrs, char *basep, const uint_t nelem,
        const uint_t elemsize, const xdrproc_t xdr_elem)
{
        uint_t i;
        char *elptr;

        elptr = basep;
        for (i = 0; i < nelem; i++) {
                if (!(*xdr_elem)(xdrs, elptr, LASTUNSIGNED))
                        return (FALSE);
                elptr += elemsize;
        }
        return (TRUE);
}

/*
 * Wrapper for xdr_string that can be called directly from
 * routines like clnt_call
 */
bool_t
xdr_wrapstring(XDR *xdrs, char **cpp)
{
        if (xdr_string(xdrs, cpp, LASTUNSIGNED))
                return (TRUE);
        return (FALSE);
}