120 lines
3.6 KiB
C
120 lines
3.6 KiB
C
/*
|
|
* Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
|
|
* Copyright (c) 2020-2021 Huawei Device Co., Ltd. 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.
|
|
*
|
|
* 3. Neither the name of the copyright holder nor the names of its contributors may be used
|
|
* to endorse or promote products derived from this software without specific prior written
|
|
* permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
|
|
*/
|
|
|
|
#include "los_random.h"
|
|
#include "fcntl.h"
|
|
#include "linux/kernel.h"
|
|
#include "fs/driver.h"
|
|
|
|
|
|
static unsigned long g_randomMax = 0x7FFFFFFF;
|
|
|
|
static long DoRand(unsigned long *value)
|
|
{
|
|
long quotient, remainder, t;
|
|
|
|
quotient = *value / 127773L;
|
|
remainder = *value % 127773L;
|
|
t = 16807L * remainder - 2836L * quotient;
|
|
if (t <= 0) {
|
|
t += 0x7fffffff;
|
|
}
|
|
return ((*value = t) % (g_randomMax + 1));
|
|
}
|
|
|
|
static unsigned long g_seed = 1;
|
|
|
|
int RanOpen(struct file *filep)
|
|
{
|
|
g_seed = (unsigned long)(LOS_CurrNanosec() & 0xffffffff);
|
|
return 0;
|
|
}
|
|
|
|
static int RanClose(struct file *filep)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int RanIoctl(struct file *filep, int cmd, unsigned long arg)
|
|
{
|
|
PRINT_ERR("random ioctl is not supported\n");
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
ssize_t RanRead(struct file *filep, char *buffer, size_t buflen)
|
|
{
|
|
ssize_t len = buflen;
|
|
char *buf = buffer;
|
|
unsigned int temp;
|
|
int ret;
|
|
|
|
if (len % sizeof(unsigned int)) {
|
|
PRINT_ERR("random size not aligned by 4 bytes\n");
|
|
return -EINVAL;
|
|
}
|
|
while (len > 0) {
|
|
temp = DoRand(&g_seed);
|
|
ret = LOS_CopyFromKernel((void *)buf, sizeof(unsigned int), (void *)&temp, sizeof(unsigned int));
|
|
if (ret) {
|
|
break;
|
|
}
|
|
len -= sizeof(unsigned int);
|
|
buf += sizeof(unsigned int);
|
|
}
|
|
return (buflen - len); /* return a successful len */
|
|
}
|
|
|
|
static ssize_t RanMap(struct file *filep, LosVmMapRegion *region)
|
|
{
|
|
PRINTK("%s %d, mmap is not support\n", __FUNCTION__, __LINE__);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations_vfs g_ranDevOps = {
|
|
RanOpen, /* open */
|
|
RanClose, /* close */
|
|
RanRead, /* read */
|
|
NULL, /* write */
|
|
NULL, /* seek */
|
|
RanIoctl, /* ioctl */
|
|
RanMap, /* mmap */
|
|
#ifndef CONFIG_DISABLE_POLL
|
|
NULL, /* poll */
|
|
#endif
|
|
NULL, /* unlink */
|
|
};
|
|
|
|
int DevRandomRegister(void)
|
|
{
|
|
return register_driver("/dev/random", &g_ranDevOps, 0666, 0); /* 0666: file mode */
|
|
}
|
|
|