54 lines
1.7 KiB
Rust
54 lines
1.7 KiB
Rust
// Copyright 2018 Developers of the Rand project.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Implementation for FreeBSD and NetBSD
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use crate::{util_libc::sys_fill_exact, Error};
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use core::ptr;
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fn kern_arnd(buf: &mut [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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pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
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// getrandom(2) was introduced in FreeBSD 12.0 and NetBSD 10.0
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#[cfg(target_os = "freebsd")]
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{
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use crate::util_libc::Weak;
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static GETRANDOM: Weak = unsafe { Weak::new("getrandom\0") };
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type GetRandomFn =
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unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::ssize_t;
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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 { func(buf.as_mut_ptr(), buf.len(), 0) });
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}
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}
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// Both FreeBSD and 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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