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/* Hurdish implementation of getrandom
Copyright (C) 2016-2021 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>
extern char *trivfs_server_name __attribute__((weak));
/* 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 (&trivfs_server_name && trivfs_server_name
&& trivfs_server_name[0] == 'r'
&& trivfs_server_name[1] == 'a'
&& trivfs_server_name[2] == 'n'
&& trivfs_server_name[3] == 'd'
&& trivfs_server_name[4] == 'o'
&& trivfs_server_name[5] == 'm'
&& trivfs_server_name[6] == '\0')
/* We are random, don't try to read ourselves! */
return length;
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)
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