xref: /freebsd/crypto/krb5/src/lib/rpc/xdr.c (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)

/* @(#)xdr.c	2.1 88/07/29 4.0 RPCSRC */
/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * All rights reserved.
 *
 * 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.
 */
#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)xdr.c 1.35 87/08/12";
#endif

/*
 * 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 <string.h>

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

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

#ifdef USE_VALGRIND
#include <valgrind/memcheck.h>
#else
#define VALGRIND_CHECK_DEFINED(LVALUE)		((void)0)
#define VALGRIND_CHECK_READABLE(PTR,SIZE)	((void)0)
#endif

/*
 * 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, void *objp)
{
	XDR x;

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

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

	return (TRUE);
}

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

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*ip);
		if (*ip > 0x7fffffffL || *ip < -0x7fffffffL - 1L)
			return (FALSE);

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

	case XDR_DECODE:
		if (!XDR_GETLONG(xdrs, &l))
			return (FALSE);

		if (l > INT_MAX || l < INT_MIN)
			return (FALSE);

		*ip = (int) l;

	case XDR_FREE:
		return (TRUE);
	}
	/*NOTREACHED*/
	return(FALSE);
}

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

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*up);
		if (*up > 0xffffffffUL)
			return (FALSE);

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

	case XDR_DECODE:
		if (!XDR_GETLONG(xdrs, (long *) &l))
			return (FALSE);

		if ((uint32_t)l > UINT_MAX)
			return (FALSE);

		*up = (u_int) l;
		return (TRUE);

	case XDR_FREE:
		return (TRUE);
	}
	/*NOTREACHED*/
	return(FALSE);
}

/*
 * XDR long integers
 */
bool_t
xdr_long(XDR *xdrs, long *lp)
{

	switch (xdrs->x_op) {
	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*lp);
		if (*lp > 0x7fffffffL || *lp < -0x7fffffffL - 1L)
			return (FALSE);

		return (XDR_PUTLONG(xdrs, lp));

	case XDR_DECODE:
		return (XDR_GETLONG(xdrs, lp));

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

/*
 * XDR unsigned long integers
 */
bool_t
xdr_u_long(XDR *xdrs, u_long *ulp)
{

	switch (xdrs->x_op) {
	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*ulp);
		if (*ulp > 0xffffffffUL)
			return (FALSE);

		return (XDR_PUTLONG(xdrs, (long *) ulp));

	case XDR_DECODE:
		return (XDR_GETLONG(xdrs, (long *) ulp));

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

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

	switch (xdrs->x_op) {

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

	case XDR_DECODE:
		if (!XDR_GETLONG(xdrs, &l)) {
			return (FALSE);
		}
		if (l > SHRT_MAX || l < SHRT_MIN)
			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, u_short *usp)
{
	u_long l;

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*usp);
		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);
}


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

	switch (xdrs->x_op) {
	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*cp);
		break;
	default:
		break;
	}
	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;

	switch (xdrs->x_op) {
	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*cp);
		break;
	default:
		break;
	}
	u = (*cp);
	if (!xdr_u_int(xdrs, &u)) {
		return (FALSE);
	}
	*cp = u;
	return (TRUE);
}

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

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*bp);
		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(XDR *xdrs, enum_t *ep)
{
#ifndef lint
	enum sizecheck { SIZEVAL };	/* used to find the size of an enum */

	/*
	 * enums are treated as ints
	 */
	switch (xdrs->x_op) {
	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*ep);
		break;
	default:
		break;
	}
	if (sizeof (enum sizecheck) == sizeof (long)) {
		return (xdr_long(xdrs, (long *)(void *)ep));
	} else if (sizeof (enum sizecheck) == sizeof (int)) {
		return (xdr_int(xdrs, (int *)(void *)ep));
	} else if (sizeof (enum sizecheck) == sizeof (short)) {
		return (xdr_short(xdrs, (short *)(void *)ep));
	} else {
		return (FALSE);
	}
#else
	(void) (xdr_short(xdrs, (short *)(void *)ep));
	return (xdr_long(xdrs, (long *)(void *)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(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) (void *)crud, rndup));
	}

	if (xdrs->x_op == XDR_ENCODE) {
		VALGRIND_CHECK_READABLE((volatile void *)cp, cnt);
		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(
	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) {
			(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(XDR *xdrs, struct netobj *np)
{

	return (xdr_bytes(xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ));
}

bool_t
xdr_int32(XDR *xdrs, int32_t *ip)
{
	long l;

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*ip);
		l = *ip;
		return (xdr_long(xdrs, &l));

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

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

bool_t
xdr_u_int32(XDR *xdrs, uint32_t *up)
{
	u_long ul;

	switch (xdrs->x_op) {

	case XDR_ENCODE:
		VALGRIND_CHECK_DEFINED(*up);
		ul = *up;
		return (xdr_u_long(xdrs, &ul));

	case XDR_DECODE:
		if (!xdr_u_long(xdrs, &ul)) {
			return (FALSE);
		}
		*up = ul;
		return (TRUE);

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

/*
 * 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,
	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 */
	)
{
	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, 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;
	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)
			*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(XDR *xdrs, char **cpp)
{
	if (xdr_string(xdrs, cpp, LASTUNSIGNED)) {
		return (TRUE);
	}
	return (FALSE);
}