/*      $OpenBSD: uuid_from_string.c,v 1.3 2021/08/30 20:41:33 krw Exp $        */
/*      $NetBSD: uuid_from_string.c,v 1.1 2004/09/13 21:44:54 thorpej Exp $     */

/*
 * Copyright (c) 2002 Marcel Moolenaar
 * Copyright (c) 2002 Hiten Mahesh Pandya
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/lib/libc/uuid/uuid_from_string.c,v 1.2 2003/08/08 19:18:43 marcel Exp $
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <uuid.h>

/*
 * uuid_from_string() - convert a string representation of an UUID into
 *                      a binary representation.
 * See also:
 *      http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
 *
 * NOTE: The sequence field is in big-endian, while the time fields are in
 *       native byte order.
 */
void
uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
{
        int n;

        /* Short-circuit 2 special cases: NULL pointer and empty string. */
        if (s == NULL || *s == '\0') {
                uuid_create_nil(u, status);
                return;
        }

        /* Assume the worst. */
        if (status != NULL)
                *status = uuid_s_invalid_string_uuid;

        /* The UUID string representation has a fixed length. */
        if (strlen(s) != UUID_STR_LEN)
                return;

        /*
         * We only work with "new" UUIDs. New UUIDs have the form:
         *      01234567-89ab-cdef-0123-456789abcdef
         * The so called "old" UUIDs, which we don't support, have the form:
         *      0123456789ab.cd.ef.01.23.45.67.89.ab
         */
        for (n = 0; n < UUID_STR_LEN; n++) {
                switch (n) {
                case 8:
                case 13:
                case 18:
                case 23:
                        if (s[n] != '-')
                                return;
                        break;
                default:
                        if (!isxdigit((unsigned char)(s[n])))
                                return;
                        break;
                }
        }

        n = sscanf(s,
            "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
            &u->time_low, &u->time_mid, &u->time_hi_and_version,
            &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
            &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);

        /* Make sure we have all conversions. */
        if (n != 11)
                return;

        /* We have a successful scan. Check semantics... */
        n = u->clock_seq_hi_and_reserved;
        if ((n & 0x80) != 0x00 &&                       /* variant 0? */
            (n & 0xc0) != 0x80 &&                       /* variant 1? */
            (n & 0xe0) != 0xc0) {                       /* variant 2? */
                if (status != NULL)
                        *status = uuid_s_bad_version;
        } else {
                if (status != NULL)
                        *status = uuid_s_ok;
        }
}