ZeroTierOne/zerotier-network-hypervisor/src/util/mod.rs
Erik Hollensbe c5b9036b9e
rustfmt tree
Signed-off-by: Erik Hollensbe <git@hollensbe.org>
2022-04-18 14:22:57 -07:00

100 lines
3 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*
* (c)2021 ZeroTier, Inc.
* https://www.zerotier.com/
*/
pub mod buffer;
pub(crate) mod gate;
pub(crate) mod pool;
pub use zerotier_core_crypto::hex;
pub use zerotier_core_crypto::varint;
pub(crate) const ZEROES: [u8; 64] = [0_u8; 64];
/// Obtain a reference to a sub-array within an existing array.
#[inline(always)]
pub(crate) fn array_range<T, const A: usize, const START: usize, const LEN: usize>(a: &[T; A]) -> &[T; LEN] {
assert!((START + LEN) <= A);
unsafe { &*a.as_ptr().add(START).cast::<[T; LEN]>() }
}
/// Obtain a reference to a sub-array within an existing array.
#[inline(always)]
pub(crate) fn array_range_mut<T, const A: usize, const START: usize, const LEN: usize>(a: &mut [T; A]) -> &mut [T; LEN] {
assert!((START + LEN) <= A);
unsafe { &mut *a.as_mut_ptr().add(START).cast::<[T; LEN]>() }
}
/// Cast a u64 to a byte array.
#[inline(always)]
pub(crate) fn u64_as_bytes(i: &u64) -> &[u8; 8] {
unsafe { &*(i as *const u64).cast() }
}
lazy_static! {
static ref HIGHWAYHASHER_KEY: [u64; 4] = [zerotier_core_crypto::random::next_u64_secure(), zerotier_core_crypto::random::next_u64_secure(), zerotier_core_crypto::random::next_u64_secure(), zerotier_core_crypto::random::next_u64_secure()];
}
/// Get an instance of HighwayHasher initialized with a secret per-process random salt.
/// The random salt is generated at process start and so will differ for each invocation of whatever process this is inside.
#[inline(always)]
pub(crate) fn highwayhasher() -> highway::HighwayHasher {
highway::HighwayHasher::new(highway::Key(HIGHWAYHASHER_KEY.clone()))
}
/// Non-cryptographic 64-bit bit mixer for things like local hashing.
#[inline(always)]
pub(crate) fn hash64_noncrypt(mut x: u64) -> u64 {
x ^= x.wrapping_shr(30);
x = x.wrapping_mul(0xbf58476d1ce4e5b9);
x ^= x.wrapping_shr(27);
x = x.wrapping_mul(0x94d049bb133111eb);
x ^ x.wrapping_shr(31)
}
/// A hasher for maps that just returns u64 values as-is.
/// Used with things like ZeroTier addresses and network IDs that are already randomly distributed.
#[derive(Copy, Clone)]
pub(crate) struct U64NoOpHasher(u64);
impl U64NoOpHasher {
#[inline(always)]
pub fn new() -> Self {
Self(0)
}
}
impl std::hash::Hasher for U64NoOpHasher {
#[inline(always)]
fn finish(&self) -> u64 {
self.0
}
#[inline(always)]
fn write(&mut self, _: &[u8]) {
panic!("U64NoOpHasher should only be used with u64 and i64 types");
}
#[inline(always)]
fn write_u64(&mut self, i: u64) {
self.0 += i;
}
#[inline(always)]
fn write_i64(&mut self, i: i64) {
self.0 += i as u64;
}
}
impl std::hash::BuildHasher for U64NoOpHasher {
type Hasher = Self;
#[inline(always)]
fn build_hasher(&self) -> Self::Hasher {
Self(0)
}
}