lib/librpc/rpc/xdr.c

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)xdr.c 1.35 87/08/12";*/
/*static char *sccsid = "from: @(#)xdr.c        2.1 88/07/29 4.0 RPCSRC";*/
static char *rcsid = "$Id: xdr.c,v 1.3 1993/08/26 00:53:46 jtc Exp $";
#endif

/*
 * xdr.c, Generic XDR routines implementation.
 *
 * Copyright (C) 1986, Sun Microsystems, Inc.
 *
 * 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 <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(proc, objp)
        xdrproc_t proc;
        char *objp;
{
        XDR x;

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

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

        return (TRUE);
}

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

#ifdef lint
        (void) (xdr_short(xdrs, (short *)ip));
        return (xdr_long(xdrs, (long *)ip));
#else
        if (sizeof (int) == sizeof (long)) {
                return (xdr_long(xdrs, (long *)ip));
        } else {
                return (xdr_short(xdrs, (short *)ip));
        }
#endif
}

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

#ifdef lint
        (void) (xdr_short(xdrs, (short *)up));
        return (xdr_u_long(xdrs, (u_long *)up));
#else
        if (sizeof (u_int) == sizeof (u_long)) {
                return (xdr_u_long(xdrs, (u_long *)up));
        } else {
                return (xdr_short(xdrs, (short *)up));
        }
#endif
}

/*
 * XDR long integers
 * same as xdr_u_long - open coded to save a proc call!
 */
bool_t
xdr_long(xdrs, lp)
        register XDR *xdrs;
        long *lp;
{

        if (xdrs->x_op == XDR_ENCODE)
                return (XDR_PUTLONG(xdrs, lp));

        if (xdrs->x_op == XDR_DECODE)
                return (XDR_GETLONG(xdrs, lp));

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

        return (FALSE);
}

/*
 * XDR unsigned long integers
 * same as xdr_long - open coded to save a proc call!
 */
bool_t
xdr_u_long(xdrs, ulp)
        register XDR *xdrs;
        u_long *ulp;
{

        if (xdrs->x_op == XDR_DECODE)
                return (XDR_GETLONG(xdrs, (long *)ulp));
        if (xdrs->x_op == XDR_ENCODE)
                return (XDR_PUTLONG(xdrs, (long *)ulp));
        if (xdrs->x_op == XDR_FREE)
                return (TRUE);
        return (FALSE);
}

/*
 * XDR short integers
 */
bool_t
xdr_short(xdrs, sp)
        register XDR *xdrs;
        short *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);
}

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

        switch (xdrs->x_op) {

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

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

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


/*
 * XDR a char
 */
bool_t
xdr_char(xdrs, cp)
        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(xdrs, cp)
        XDR *xdrs;
        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(xdrs, bp)
        register XDR *xdrs;
        bool_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);
}

/*
 * XDR enumerations
 */
bool_t
xdr_enum(xdrs, ep)
        XDR *xdrs;
        enum_t *ep;
{
#ifndef lint
        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 (short)) {
                return (xdr_short(xdrs, (short *)ep));
        } else {
                return (FALSE);
        }
#else
        (void) (xdr_short(xdrs, (short *)ep));
        return (xdr_long(xdrs, (long *)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.
 */
bool_t
xdr_opaque(xdrs, cp, cnt)
        register XDR *xdrs;
        caddr_t cp;
        register u_int cnt;
{
        register u_int rndup;
        static 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, 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
 */
bool_t
xdr_bytes(xdrs, cpp, sizep, maxsize)
        register XDR *xdrs;
        char **cpp;
        register u_int *sizep;
        u_int maxsize;
{
        register char *sp = *cpp;  /* sp is the actual string pointer */
        register 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) {
                        (void) fprintf(stderr, "xdr_bytes: out of memory\n");
                        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);
}

/*
 * Implemented here due to commonality of the object.
 */
bool_t
xdr_netobj(xdrs, np)
        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(xdrs, dscmp, unp, choices, dfault)
        register XDR *xdrs;
        enum_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 */
{
        register 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(xdrs, cpp, maxsize)
        register XDR *xdrs;
        char **cpp;
        u_int maxsize;
{
        register 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;
        }
        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) {
                        (void) fprintf(stderr, "xdr_string: out of memory\n");
                        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);
}

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