glibc/sysdeps/mach/hurd/getrandom.c

51 lines
1.6 KiB
C

/* Hurdish implementation of getrandom
Copyright (C) 2016-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sys/random.h>
#include <fcntl.h>
#include <unistd.h>
#include <not-cancel.h>
/* Write up to LENGTH bytes of randomness starting at BUFFER.
Return the number of bytes written, or -1 on error. */
ssize_t
__getrandom (void *buffer, size_t length, unsigned int flags)
{
const char *random_source = "/dev/urandom";
int open_flags = O_RDONLY | O_CLOEXEC;
size_t amount_read;
int fd;
if (flags & GRND_RANDOM)
random_source = "/dev/random";
if (flags & GRND_NONBLOCK)
open_flags |= O_NONBLOCK;
fd = __open_nocancel(random_source, open_flags);
if (fd == -1)
return -1;
amount_read = __read_nocancel(fd, buffer, length);
__close_nocancel_nostatus(fd);
return amount_read;
}
libc_hidden_def (__getrandom)
weak_alias (__getrandom, getrandom)