libnsl/rpc/xdr.c

	xdr.c revision 61961e0f20c7637a3846bb39786bb9dffa91dfb9
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * 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 <stdlib.h>
#include <sys/types.h>
#include <sys/isa_defs.h>
#include <syslog.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <inttypes.h>
#include <sys/sysmacros.h>
#include <assert.h>

#pragma weak xdr_int64_t = xdr_hyper
#pragma weak xdr_uint64_t = xdr_u_hyper
#pragma weak xdr_int32_t = xdr_int
#pragma weak xdr_uint32_t = xdr_u_int
#pragma weak xdr_int16_t = xdr_short
#pragma weak xdr_uint16_t = xdr_u_short
#pragma weak xdr_int8_t = xdr_char
#pragma weak xdr_uint8_t = xdr_u_char

/*
 * The following routine was part of a workaround for an rpcgen
 * that was fixed, this routine should be removed sometime.
 */
#pragma weak xdr_ulonglong_t = xdr_u_longlong_t

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

/* fragment size to use when doing an xdr_string() */
#define FRAGMENT    65536

/*
 * for unit alignment
 */
static const char xdr_zero[BYTES_PER_XDR_UNIT]  = { 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);
}

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

/*
 * xdr_time_t  sends time_t value over the wire.
 * Due to RPC Protocol limitation, it can only send
 * up to 32-bit integer quantity over the wire.
 *
 */
bool_t
xdr_time_t(XDR *xdrs, time_t *tp)
{
    int32_t i;

    switch (xdrs->x_op) {
    case XDR_ENCODE:
    /*
     * Check for the time overflow, when encoding it.
     * Don't want to send OTW the time value too large to
     * handle by the protocol.
     */
#if defined(_LP64)
    if (*tp > INT32_MAX)
        *tp = INT32_MAX;
    else if (*tp < INT32_MIN)
        *tp = INT32_MIN;
#endif
        i =  (int32_t)*tp;
        return (XDR_PUTINT32(xdrs, &i));

    case XDR_DECODE:
        if (!XDR_GETINT32(xdrs, &i))
            return (FALSE);
        *tp = (time_t)i;
        return (TRUE);

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

/*
 * XDR integers
 */
bool_t
xdr_int(XDR *xdrs, int *ip)
{
    switch (xdrs->x_op) {
    case XDR_ENCODE:
        return (XDR_PUTINT32(xdrs, ip));
    case XDR_DECODE:
        return (XDR_GETINT32(xdrs, ip));
    case XDR_FREE:
        return (TRUE);
    }
    return (FALSE);
}

/*
 * XDR unsigned integers
 */
bool_t
xdr_u_int(XDR *xdrs, uint_t *up)
{
    switch (xdrs->x_op) {
    case XDR_ENCODE:
        return (XDR_PUTINT32(xdrs, (int *)up));
    case XDR_DECODE:
        return (XDR_GETINT32(xdrs, (int *)up));
    case XDR_FREE:
        return (TRUE);
    }
    return (FALSE);
}

/*
 * The definition of xdr_long()/xdr_u_long() is kept for backward
 * compatibitlity.
 * XDR long integers, same as xdr_u_long
 */
bool_t
xdr_long(XDR *xdrs, long *lp)
{
    int32_t i;

    switch (xdrs->x_op) {
    case XDR_ENCODE:
#if defined(_LP64)
        if ((*lp > INT32_MAX) || (*lp < INT32_MIN))
            return (FALSE);
#endif
        i = (int32_t)*lp;
        return (XDR_PUTINT32(xdrs, &i));
    case XDR_DECODE:
        if (!XDR_GETINT32(xdrs, &i))
            return (FALSE);
        *lp = (long)i;
        return (TRUE);
    case XDR_FREE:
        return (TRUE);
    }
    return (FALSE);
}

/*
 * XDR unsigned long integers
 * same as xdr_long
 */
bool_t
xdr_u_long(XDR *xdrs, ulong_t *ulp)
{
    uint32_t ui;

    switch (xdrs->x_op) {
    case XDR_ENCODE:
#if defined(_LP64)
        if (*ulp > UINT32_MAX)
            return (FALSE);
#endif
        ui = (uint32_t)*ulp;
        return (XDR_PUTINT32(xdrs, (int32_t *)&ui));
    case XDR_DECODE:
        if (!XDR_GETINT32(xdrs, (int32_t *)&ui))
            return (FALSE);
        *ulp = (ulong_t)ui;
        return (TRUE);
    case XDR_FREE:
        return (TRUE);
    }
    return (FALSE);
}

/*
 * 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)
{
    uint_t i;

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

/*
 * 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
 */
bool_t
xdr_bool(XDR *xdrs, bool_t *bp)
{
    int i;

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

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

    /*
     * enums are treated as ints
     */
    /* CONSTCOND */
    assert(sizeof (enum sizecheck) == sizeof (int32_t));
    return (xdr_int(xdrs, (int *)ep));
}

/*
 * 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, const uint_t cnt)
{
    uint_t rndup;
    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 ((int)rndup > 0)
        rndup = BYTES_PER_XDR_UNIT - rndup;

    switch (xdrs->x_op) {
    case XDR_DECODE:
        if (!XDR_GETBYTES(xdrs, cp, cnt))
            return (FALSE);
        if (rndup == 0)
            return (TRUE);
        return (XDR_GETBYTES(xdrs, crud, rndup));
    case XDR_ENCODE:
        if (!XDR_PUTBYTES(xdrs, cp, cnt))
            return (FALSE);
        if (rndup == 0)
            return (TRUE);
        return (XDR_PUTBYTES(xdrs, (caddr_t)&xdr_zero[0], rndup));
    case 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
 */

static const char xdr_err[] = "xdr_%s: out of memory";

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
     * We decided not to use MACRO XDR_U_INT here, because the
     * advantages here will be miniscule compared to xdr_bytes.
     * This saved us 100 bytes in the library size.
     */
    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 = malloc(nodesize);
        if (sp == NULL) {
            (void) syslog(LOG_ERR, xdr_err, (const char *)"bytes");
            return (FALSE);
        }
        /*FALLTHROUGH*/
    case XDR_ENCODE:
        return (xdr_opaque(xdrs, sp, nodesize));
    case XDR_FREE:
        if (sp != NULL) {
            free(sp);
            *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 *newsp, *sp = *cpp;  /* sp is the actual string pointer */
    uint_t size, block;
    uint64_t bytesread;

    /*
     * 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;
    }
    /*
     * We decided not to use MACRO XDR_U_INT here, because the
     * advantages here will be miniscule compared to xdr_string.
     * This saved us 100 bytes in the library size.
     */
    if (!xdr_u_int(xdrs, &size))
        return (FALSE);
    if (size > maxsize)
        return (FALSE);

    /*
     * now deal with the actual bytes
     */
    switch (xdrs->x_op) {
    case XDR_DECODE:
        /* if buffer is already given, call xdr_opaque() directly */
        if (sp != NULL) {
            if (!xdr_opaque(xdrs, sp, size))
                return (FALSE);
            sp[size] = 0;
            return (TRUE);
        }

        /*
         * We have to allocate a buffer of size 'size'. To avoid
         * malloc()ing one huge chunk, we'll read the bytes in max
         * FRAGMENT size blocks and keep realloc()ing. 'block' is
         * the number of bytes to read in each xdr_opaque() and
         * 'bytesread' is what we have already read. sp is NULL
         * when we are in the loop for the first time.
         */
        bytesread = 0;
        do {
            block = MIN(size - bytesread, FRAGMENT);
            /*
             * allocate enough for 'bytesread + block' bytes and
             * one extra for the terminating NULL.
             */
            newsp = realloc(sp, bytesread + block + 1);
            if (newsp == NULL) {
                if (sp != NULL)
                    free(sp);
                return (FALSE);
            }
            sp = newsp;
            if (!xdr_opaque(xdrs, &sp[bytesread], block)) {
                free(sp);
                return (FALSE);
            }
            bytesread += block;
        } while (bytesread < size);

        sp[bytesread] = 0; /* terminate the string with a NULL */
        *cpp = sp;
        return (TRUE);
    case XDR_ENCODE:
        return (xdr_opaque(xdrs, sp, size));
    case XDR_FREE:
        free(sp);
        *cpp = NULL;
        return (TRUE);
    }
    return (FALSE);
}

bool_t
xdr_hyper(XDR *xdrs, longlong_t *hp)
{
    if (xdrs->x_op == XDR_ENCODE) {
#if defined(_LONG_LONG_HTOL)
        if (XDR_PUTINT32(xdrs, (int *)hp) == TRUE)
            /* LINTED pointer cast */
            return (XDR_PUTINT32(xdrs, (int *)((char *)hp +
                BYTES_PER_XDR_UNIT)));
#else
        /* LINTED pointer cast */
        if (XDR_PUTINT32(xdrs, (int *)((char *)hp +
                BYTES_PER_XDR_UNIT)) == TRUE)
            return (XDR_PUTINT32(xdrs, (int32_t *)hp));
#endif
        return (FALSE);
    }

    if (xdrs->x_op == XDR_DECODE) {
#if defined(_LONG_LONG_HTOL)
        if (XDR_GETINT32(xdrs, (int *)hp) == FALSE ||
            /* LINTED pointer cast */
            (XDR_GETINT32(xdrs, (int *)((char *)hp +
                BYTES_PER_XDR_UNIT)) == FALSE))
            return (FALSE);
#else
        /* LINTED pointer cast */
        if ((XDR_GETINT32(xdrs, (int *)((char *)hp +
                BYTES_PER_XDR_UNIT)) == FALSE) ||
                (XDR_GETINT32(xdrs, (int *)hp) == FALSE))
            return (FALSE);
#endif
        return (TRUE);
    }
    return (TRUE);
}

bool_t
xdr_u_hyper(XDR *xdrs, u_longlong_t *hp)
{
    return (xdr_hyper(xdrs, (longlong_t *)hp));
}

bool_t
xdr_longlong_t(XDR *xdrs, longlong_t *hp)
{
    return (xdr_hyper(xdrs, hp));
}

bool_t
xdr_u_longlong_t(XDR *xdrs, u_longlong_t *hp)
{
    return (xdr_hyper(xdrs, (longlong_t *)hp));
}

/*
 * 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));
}