nuttx/libs/libc/uuid/lib_uuid_create.c
Xiang Xiao 6c03a4e4d5 libc: Add uuid implemenation
specified by OpenGroup here:
https://pubs.opengroup.org/onlinepubs/009629399/toc.htm

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: I3bc585e7f4d41f6c2ea70e170276ab0d0399b088
2020-07-21 21:48:18 -07:00

71 lines
2.2 KiB
C

/****************************************************************************
* libs/libc/uuid/lib_uuid_create.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/random.h>
#include <stdlib.h>
#include <uuid.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* uuid_create_nil
*
* Description:
* Create an UUID.
*
* See also:
* http://www.opengroup.org/onlinepubs/009629399/uuid_create.htm
*
****************************************************************************/
void uuid_create(uuid_t *u, uint32_t *status)
{
#ifdef CONFIG_CRYPTO_RANDOM_POOL
getrandom(u, sizeof(uuid_t));
#else
unsigned long *beg = (unsigned long *)u;
unsigned long *end = (unsigned long *)(u + 1);
while (beg < end)
{
*beg++ = rand();
}
#endif
u->clock_seq_hi_and_reserved &= ~(1 << 6);
u->clock_seq_hi_and_reserved |= (1 << 7);
u->time_hi_and_version &= ~(1 << 12);
u->time_hi_and_version &= ~(1 << 13);
u->time_hi_and_version |= (1 << 14);
u->time_hi_and_version &= ~(1 << 15);
if (status)
{
*status = uuid_s_ok;
}
}