Artyom Pavlov
22 lines
769 B
Rust
22 lines
769 B
Rust
use crate::Error;
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use core::{cmp::min, mem::MaybeUninit, num::NonZeroU32};
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extern "C" {
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fn sys_read_entropy(buffer: *mut u8, length: usize, flags: u32) -> isize;
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}
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pub fn getrandom_inner(mut dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
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while !dest.is_empty() {
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let res = unsafe { sys_read_entropy(dest.as_mut_ptr() as *mut u8, dest.len(), 0) };
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if res < 0 {
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// SAFETY: all Hermit error codes use i32 under the hood:
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// https://github.com/hermitcore/libhermit-rs/blob/master/src/errno.rs
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let code = unsafe { NonZeroU32::new_unchecked((-res) as u32) };
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return Err(code.into());
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}
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let len = min(res as usize, dest.len());
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dest = &mut dest[len..];
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}
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Ok(())
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}
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