/*      $OpenBSD: xdr.c,v 1.17 2022/12/27 17:10:06 jmc Exp $ */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 *   COPYRIGHT HOLDER 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.
 */

/*
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

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

/*
 * constants specific to the xdr "protocol"
 */
#define XDR_FALSE       ((long) 0)
#define XDR_TRUE        ((long) 1)
#define LASTUNSIGNED    ((u_int) 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;
        (*proc)(&x, objp);
}
DEF_WEAK(xdr_free);

/*
 * XDR nothing
 */
bool_t
xdr_void(void)
        /* XDR *xdrs; */
        /* caddr_t addr; */
{

        return (TRUE);
}
DEF_WEAK(xdr_void);


/*
 * XDR integers
 */
bool_t
xdr_int(XDR *xdrs, int *ip)
{
        long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (long) *ip;
                return (XDR_PUTLONG(xdrs, &l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, &l)) {
                        return (FALSE);
                }
                *ip = (int) l;
                return (TRUE);

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

/*
 * XDR unsigned integers
 */
bool_t
xdr_u_int(XDR *xdrs, u_int *up)
{
        u_long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (u_long) *up;
                return (XDR_PUTLONG(xdrs, (long *)&l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, (long *)&l)) {
                        return (FALSE);
                }
                *up = (u_int) l;
                return (TRUE);

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


/*
 * XDR long integers
 * same as xdr_u_long - open coded to save a proc call!
 */
bool_t
xdr_long(XDR *xdrs, long int *lp)
{
        switch (xdrs->x_op) {
        case XDR_ENCODE:
                return (XDR_PUTLONG(xdrs, lp));
        case XDR_DECODE:
                return (XDR_GETLONG(xdrs, lp));
        case XDR_FREE:
                return (TRUE);
        }

        return (FALSE);
}
DEF_WEAK(xdr_long);

/*
 * XDR unsigned long integers
 * same as xdr_long - open coded to save a proc call!
 */
bool_t
xdr_u_long(XDR *xdrs, u_long *ulp)
{
        switch (xdrs->x_op) {
        case XDR_ENCODE:
                return (XDR_PUTLONG(xdrs, (long *)ulp));
        case XDR_DECODE:
                return (XDR_GETLONG(xdrs, (long *)ulp));
        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}
DEF_WEAK(xdr_u_long);


/*
 * XDR 32-bit integers
 * same as xdr_u_int32_t - open coded to save a proc call!
 */
bool_t
xdr_int32_t(XDR *xdrs, int32_t *int32_p)
{
        long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (long) *int32_p;
                return (XDR_PUTLONG(xdrs, &l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, &l)) {
                        return (FALSE);
                }
                *int32_p = (int32_t) l;
                return (TRUE);

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

/*
 * XDR unsigned 32-bit integers
 * same as xdr_int32_t - open coded to save a proc call!
 */
bool_t
xdr_u_int32_t(XDR *xdrs, u_int32_t *u_int32_p)
{
        u_long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (u_long) *u_int32_p;
                return (XDR_PUTLONG(xdrs, (long *)&l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, (long *)&l)) {
                        return (FALSE);
                }
                *u_int32_p = (u_int32_t) l;
                return (TRUE);

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}
DEF_WEAK(xdr_u_int32_t);


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

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (long) *sp;
                return (XDR_PUTLONG(xdrs, &l));

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

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

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

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (u_long) *usp;
                return (XDR_PUTLONG(xdrs, (long *)&l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, (long *)&l)) {
                        return (FALSE);
                }
                *usp = (u_short) l;
                return (TRUE);

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


/*
 * XDR 16-bit integers
 */
bool_t
xdr_int16_t(XDR *xdrs, int16_t *int16_p)
{
        long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (long) *int16_p;
                return (XDR_PUTLONG(xdrs, &l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, &l)) {
                        return (FALSE);
                }
                *int16_p = (int16_t) l;
                return (TRUE);

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

/*
 * XDR unsigned 16-bit integers
 */
bool_t
xdr_u_int16_t(XDR *xdrs, u_int16_t *u_int16_p)
{
        u_long l;

        switch (xdrs->x_op) {

        case XDR_ENCODE:
                l = (u_long) *u_int16_p;
                return (XDR_PUTLONG(xdrs, (long *)&l));

        case XDR_DECODE:
                if (!XDR_GETLONG(xdrs, (long *)&l)) {
                        return (FALSE);
                }
                *u_int16_p = (u_int16_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 = i;
        return (TRUE);
}

/*
 * XDR an unsigned char
 */
bool_t
xdr_u_char(XDR *xdrs, u_char *cp)
{
        u_int u;

        u = (*cp);
        if (!xdr_u_int(xdrs, &u)) {
                return (FALSE);
        }
        *cp = u;
        return (TRUE);
}

/*
 * XDR booleans
 */
bool_t
xdr_bool(XDR *xdrs, int32_t *bp)
{
        long lb;

        switch (xdrs->x_op) {

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

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

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

/*
 * XDR enumerations
 */
bool_t
xdr_enum(XDR *xdrs, int32_t *ep)
{
        enum sizecheck { SIZEVAL };     /* used to find the size of an enum */

        /*
         * enums are treated as ints
         */
        if (sizeof (enum sizecheck) == sizeof (long)) {
                return (xdr_long(xdrs, (long *)ep));
        } else if (sizeof (enum sizecheck) == sizeof (int)) {
                return (xdr_int(xdrs, (int *)ep));
        } else if (sizeof (enum sizecheck) == sizeof (short)) {
                return (xdr_short(xdrs, (short *)ep));
        } else {
                return (FALSE);
        }
}
DEF_WEAK(xdr_enum);

/*
 * 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.
 */
bool_t
xdr_opaque(XDR *xdrs, caddr_t cp, u_int cnt)
{
        u_int rndup;
        static int 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);
}
DEF_WEAK(xdr_opaque);

/*
 * XDR counted bytes
 * *cpp is a pointer to the bytes, *sizep is the count.
 * If *cpp is NULL maxsize bytes are allocated
 */
bool_t
xdr_bytes(XDR *xdrs, char **cpp, u_int *sizep, u_int maxsize)
{
        char *sp = *cpp;  /* sp is the actual string pointer */
        u_int 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);
                }
                if (sp == NULL)
                        return (FALSE);
                /* fall into ... */

        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);
}
DEF_WEAK(xdr_bytes);

/*
 * 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 discriminated 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,
    int32_t *dscmp,             /* enum to decide which arm to work on */
    char *unp,                  /* the union itself */
    struct xdr_discrim *choices,        /* [value, xdr proc] for each arm */
    xdrproc_t dfault)           /* default xdr routine */
{
        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; choices++) {
                if (choices->value == dscm)
                        return ((*(choices->proc))(xdrs, unp));
        }

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


/*
 * 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, u_int maxsize)
{
        char *sp = *cpp;  /* sp is the actual string pointer */
        u_int size;
        u_int 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 */
                }
                /* fall through... */
        case XDR_ENCODE:
                size = strlen(sp);
                break;
        default:
                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)
                        *cpp = sp = (char *)mem_alloc(nodesize);
                if (sp == NULL)
                        return (FALSE);
                sp[size] = 0;
                /* fall into ... */

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

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

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

bool_t
xdr_int64_t(XDR *xdrs, int64_t *llp)
{
        u_long ul[2];

        switch (xdrs->x_op) {
        case XDR_ENCODE:
                ul[0] = (u_long)((u_int64_t)*llp >> 32) & 0xffffffff;
                ul[1] = (u_long)((u_int64_t)*llp) & 0xffffffff;
                if (XDR_PUTLONG(xdrs, (long *)&ul[0]) == FALSE)
                        return (FALSE);
                return (XDR_PUTLONG(xdrs, (long *)&ul[1]));
        case XDR_DECODE:
                if (XDR_GETLONG(xdrs, (long *)&ul[0]) == FALSE)
                        return (FALSE);
                if (XDR_GETLONG(xdrs, (long *)&ul[1]) == FALSE)
                        return (FALSE);
                *llp = (int64_t)
                    (((u_int64_t)ul[0] << 32) | ((u_int64_t)ul[1]));
                return (TRUE);
        case XDR_FREE:
                return (TRUE);
        }
        /* NOTREACHED */
        return (FALSE);
}

bool_t
xdr_u_int64_t(XDR *xdrs, u_int64_t *ullp)
{
        u_long ul[2];

        switch (xdrs->x_op) {
        case XDR_ENCODE:
                ul[0] = (u_long)(*ullp >> 32) & 0xffffffff;
                ul[1] = (u_long)(*ullp) & 0xffffffff;
                if (XDR_PUTLONG(xdrs, (long *)&ul[0]) == FALSE)
                        return (FALSE);
                return (XDR_PUTLONG(xdrs, (long *)&ul[1]));
        case XDR_DECODE:
                if (XDR_GETLONG(xdrs, (long *)&ul[0]) == FALSE)
                        return (FALSE);
                if (XDR_GETLONG(xdrs, (long *)&ul[1]) == FALSE)
                        return (FALSE);
                *ullp = (u_int64_t)
                    (((u_int64_t)ul[0] << 32) | ((u_int64_t)ul[1]));
                return (TRUE);
        case XDR_FREE:
                return (TRUE);
        }
        /* NOTREACHED */
        return (FALSE);
}