47 lines
1.3 KiB
Rust
47 lines
1.3 KiB
Rust
//! Implementation for NetBSD
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use crate::{
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util_libc::{sys_fill_exact, Weak},
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Error,
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};
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use core::{mem::MaybeUninit, ptr};
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fn kern_arnd(buf: &mut [MaybeUninit<u8>]) -> libc::ssize_t {
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static MIB: [libc::c_int; 2] = [libc::CTL_KERN, libc::KERN_ARND];
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let mut len = buf.len();
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let ret = unsafe {
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libc::sysctl(
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MIB.as_ptr(),
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MIB.len() as libc::c_uint,
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buf.as_mut_ptr() as *mut _,
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&mut len,
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ptr::null(),
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0,
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)
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};
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if ret == -1 {
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-1
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} else {
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len as libc::ssize_t
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}
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}
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type GetRandomFn = unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::ssize_t;
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pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
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// getrandom(2) was introduced in NetBSD 10.0
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static GETRANDOM: Weak = unsafe { Weak::new("getrandom\0") };
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if let Some(fptr) = GETRANDOM.ptr() {
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let func: GetRandomFn = unsafe { core::mem::transmute(fptr) };
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return sys_fill_exact(dest, |buf| unsafe {
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func(buf.as_mut_ptr() as *mut u8, buf.len(), 0)
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});
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}
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// NetBSD will only return up to 256 bytes at a time, and
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// older NetBSD kernels will fail on longer buffers.
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for chunk in dest.chunks_mut(256) {
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sys_fill_exact(chunk, kern_arnd)?
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}
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Ok(())
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}
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