incubator-nuttx/libs/libc/uuid/lib_uuid_create.c

107 lines
2.9 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 <errno.h>
#include <stdlib.h>
#include <uuid.h>
/****************************************************************************
* Private Functions
****************************************************************************/
static int uuid_getrandom(FAR void *buf, size_t size, int flags)
{
FAR char *tmp = buf;
while (size > 0)
{
ssize_t ret = getrandom(tmp, size, flags);
if (ret < 0)
{
if (get_errno() == EINTR)
{
continue;
}
return ret;
}
tmp += ret;
size -= ret;
}
return 0;
}
/****************************************************************************
* 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)
{
int ret;
ret = uuid_getrandom(u, sizeof(uuid_t), 0);
if (ret < 0)
{
ret = uuid_getrandom(u, sizeof(uuid_t), GRND_RANDOM);
}
if (ret < 0)
{
unsigned long *beg = (unsigned long *)u;
unsigned long *end = (unsigned long *)(u + 1);
while (beg < end)
{
*beg++ = rand();
}
}
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;
}
}