freebsd-dev/lib/libstand/uuid_from_string.c

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/*-
* Copyright (c) 2015 M. Warner Losh
* 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.
*
* $FreeBSD$
*/
/*
* Note: some comments taken from lib/libc/uuid/uuid_from_string.c
* Copyright (c) 2002 Marcel Moolenaar
* Copyright (c) 2002 Hiten Mahesh Pandya
*/
#include <stand.h>
#include <uuid.h>
static int
hex2int(int ch)
{
if (ch >= '0' && ch <= '9')
return ch - '0';
if (ch >= 'a' && ch <= 'f')
return 10 + ch - 'a';
if (ch >= 'A' && ch <= 'F')
return 10 + ch - 'A';
return 16;
}
static uint32_t
fromhex(const char *s, int len, int *ok)
{
uint32_t v;
int i, h;
if (!*ok)
return 0;
v = 0;
for (i = 0; i < 8; i++) {
h = hex2int(s[i]);
if (h == 16) {
*ok = 0;
return v;
}
v = (v << 4) | h;
}
return v;
}
/*
* 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.
*
* 01234567-89ab-cdef-0123-456789abcdef
* 000000000011111111112222222222333333
* 012345678901234567890123456789012345
* - - - -
* hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
*
*/
void
uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
{
int ok = 1;
int n;
if (s == NULL || *s == '\0') {
uuid_create_nil(u, status);
return;
}
if (status != NULL)
*status = uuid_s_invalid_string_uuid;
if (strlen(s) != 36)
return;
/* Only support new format, check for all the right dashes */
if (s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-')
return;
/* native byte order */
u->time_low = fromhex(s , 8, &ok);
u->time_mid = fromhex(s + 9, 4, &ok);
u->time_hi_and_version = fromhex(s + 14, 4, &ok);
/* Big endian, but presented as a whole number so decode as such */
u->clock_seq_hi_and_reserved = fromhex(s + 19, 2, &ok);
u->clock_seq_low = fromhex(s + 21, 2, &ok);
u->node[0] = fromhex(s + 24, 2, &ok);
u->node[1] = fromhex(s + 26, 2, &ok);
u->node[2] = fromhex(s + 28, 2, &ok);
u->node[3] = fromhex(s + 30, 2, &ok);
u->node[4] = fromhex(s + 32, 2, &ok);
u->node[5] = fromhex(s + 34, 2, &ok);
if (!ok)
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;
}
}