1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
use crate::util_libc::{last_os_error, Weak};
use crate::{use_file, Error};
use core::mem;
type GetEntropyFn = unsafe extern "C" fn(*mut u8, libc::size_t) -> libc::c_int;
pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
static GETENTROPY: Weak = unsafe { Weak::new("getentropy\0") };
if let Some(fptr) = GETENTROPY.ptr() {
let func: GetEntropyFn = unsafe { mem::transmute(fptr) };
for chunk in dest.chunks_mut(256) {
let ret = unsafe { func(chunk.as_mut_ptr(), chunk.len()) };
if ret != 0 {
let err = last_os_error();
error!("getentropy syscall failed");
return Err(err);
}
}
Ok(())
} else {
use_file::getrandom_inner(dest)
}
}