source: trunk/gsdl/packages/yaz/odr/ber_int.c@ 1343

/*
 * Copyright (c) 1995-2000, Index Data
 * See the file LICENSE for details.
 * Sebastian Hammer, Adam Dickmeiss
 *
 * $Log$
 * Revision 1.1  2000/08/03 03:11:13  johnmcp
 * Added the YAZ toolkit source to the packages directory (for z39.50 stuff)
 *
 * Revision 1.18  2000/02/29 13:44:55  adam
 * Check for config.h (currently not generated).
 *
 * Revision 1.17  2000/02/28 11:20:06  adam
 * Using autoconf. New definitions: YAZ_BEGIN_CDECL/YAZ_END_CDECL.
 *
 * Revision 1.16  2000/01/31 13:15:21  adam
 * Removed uses of assert(3). Cleanup of ODR. CCL parser update so
 * that some characters are not surrounded by spaces in resulting term.
 * ILL-code updates.
 *
 * Revision 1.15  1999/11/30 13:47:11  adam
 * Improved installation. Moved header files to include/yaz.
 *
 * Revision 1.14  1999/05/26 07:49:35  adam
 * C++ compilation.
 *
 * Revision 1.13  1999/01/08 11:23:22  adam
 * Added const modifier to some of the BER/ODR encoding routines.
 *
 * Revision 1.12  1996/07/06 19:58:33  quinn
 * System headerfiles gathered in yconfig
 *
 * Revision 1.11  1995/09/29  17:12:16  quinn
 * Smallish
 *
 * Revision 1.10  1995/09/29  17:01:50  quinn
 * More Windows work
 *
 * Revision 1.9  1995/09/28  10:12:39  quinn
 * Windows-support changes
 *
 * Revision 1.8  1995/09/27  15:02:55  quinn
 * Modified function heads & prototypes.
 *
 * Revision 1.7  1995/05/16  08:50:44  quinn
 * License, documentation, and memory fixes
 *
 * Revision 1.6  1995/04/18  08:15:14  quinn
 * Added dynamic memory allocation on encoding (whew). Code is now somewhat
 * neater. We'll make the same change for decoding one day.
 *
 * Revision 1.5  1995/03/27  15:01:44  quinn
 * Added include of sys/types to further portability
 *
 * Revision 1.4  1995/03/08  12:12:07  quinn
 * Added better error checking.
 *
 * Revision 1.3  1995/02/09  15:51:46  quinn
 * Works better now.
 *
 * Revision 1.2  1995/02/07  17:52:58  quinn
 * A damn mess, but now things work, I think.
 *
 * Revision 1.1  1995/02/02  16:21:52  quinn
 * First kick.
 *
 */
#if HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#ifdef WIN32
#include <winsock.h>
#else
#include <arpa/inet.h>
#endif

#include <yaz/odr.h>

static int ber_encinteger(ODR o, int val);
static int ber_decinteger(const unsigned char *buf, int *val);

int ber_integer(ODR o, int *val)
{
    int res;

    switch (o->direction)
    {
        case ODR_DECODE:
            if ((res = ber_decinteger(o->bp, val)) <= 0)
            {
                o->error = OPROTO;
                return 0;
            }
            o->bp += res;
            return 1;
        case ODR_ENCODE:
            if ((res = ber_encinteger(o, *val)) < 0)
                return 0;
            return 1;
        case ODR_PRINT: return 1;
        default: o->error = OOTHER;  return 0;
    }
}

/*
 * Returns: number of bytes written or -1 for error (out of bounds).
 */
int ber_encinteger(ODR o, int val)
{
    int lenpos;
    int a, len;
    union { int i; unsigned char c[sizeof(int)]; } tmp;

    lenpos = odr_tell(o);
    if (odr_putc(o, 0) < 0)  /* dummy */
        return -1;
    tmp.i = htonl(val);   /* ensure that that we're big-endian */
    for (a = 0; a < (int) sizeof(int) - 1; a++)  /* skip superfluous octets */
        if (!((tmp.c[a] == 0 && !(tmp.c[a+1] & 0X80)) ||
            (tmp.c[a] == 0XFF && (tmp.c[a+1] & 0X80))))
            break;
    len = sizeof(int) - a;
    if (odr_write(o, (unsigned char*) tmp.c + a, len) < 0)
        return -1;
    odr_seek(o, ODR_S_SET, lenpos);
    if (ber_enclen(o, len, 1, 1) != 1)
        return -1;
    odr_seek(o, ODR_S_END, 0);
#ifdef ODR_DEBUG
    fprintf(stderr, "[val=%d]", val);
#endif
    return 0;
}

/*
 * Returns: Number of bytes read or 0 if no match, -1 if error.
 */
int ber_decinteger(const unsigned char *buf, int *val)
{
    const unsigned char *b = buf;
    unsigned char fill;
    int res, len, remains;
    union { int i; unsigned char c[sizeof(int)]; } tmp;

    if ((res = ber_declen(b, &len)) < 0)
        return -1;
    if (len > (int) sizeof(int))    /* let's be reasonable, here */
        return -1;
    b+= res;

    remains = sizeof(int) - len;
    memcpy(tmp.c + remains, b, len);
    if (*b & 0X80)
        fill = 0XFF;
    else
        fill = 0X00;
    memset(tmp.c, fill, remains);
    *val = ntohl(tmp.i);

    b += len;
#ifdef ODR_DEBUG
    fprintf(stderr, "[val=%d]", *val);
#endif
    return b - buf;
}