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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Encoding and decoding packets off the wire.
use neqo_common::{hex, hex_with_len, Decoder};
use neqo_crypto::random;
use std::borrow::Borrow;
use std::cmp::max;
use std::convert::AsRef;
pub const MAX_CONNECTION_ID_LEN: usize = 20;
#[derive(Clone, Default, Eq, Hash, PartialEq)]
pub struct ConnectionId {
pub(crate) cid: Vec<u8>,
}
impl ConnectionId {
pub fn generate(len: usize) -> Self {
assert!(matches!(len, 0..=MAX_CONNECTION_ID_LEN));
Self { cid: random(len) }
}
// Apply a wee bit of greasing here in picking a length between 8 and 20 bytes long.
pub fn generate_initial() -> Self {
let v = random(1);
// Bias selection toward picking 8 (>50% of the time).
let len: usize = max(8, 5 + (v[0] & (v[0] >> 4))).into();
Self::generate(len)
}
pub fn as_cid_ref(&self) -> ConnectionIdRef {
ConnectionIdRef::from(&self.cid[..])
}
}
impl AsRef<[u8]> for ConnectionId {
fn as_ref(&self) -> &[u8] {
self.borrow()
}
}
impl Borrow<[u8]> for ConnectionId {
fn borrow(&self) -> &[u8] {
&self.cid
}
}
impl From<&[u8]> for ConnectionId {
fn from(buf: &[u8]) -> Self {
Self {
cid: Vec::from(buf),
}
}
}
impl<'a> From<&ConnectionIdRef<'a>> for ConnectionId {
fn from(cidref: &ConnectionIdRef<'a>) -> Self {
Self {
cid: Vec::from(cidref.cid),
}
}
}
impl std::ops::Deref for ConnectionId {
type Target = [u8];
fn deref(&self) -> &Self::Target {
&self.cid
}
}
impl ::std::fmt::Debug for ConnectionId {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(f, "CID {}", hex_with_len(&self.cid))
}
}
impl ::std::fmt::Display for ConnectionId {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(f, "{}", hex(&self.cid))
}
}
impl<'a> PartialEq<ConnectionIdRef<'a>> for ConnectionId {
fn eq(&self, other: &ConnectionIdRef<'a>) -> bool {
&self.cid[..] == other.cid
}
}
#[derive(Hash, Eq, PartialEq)]
pub struct ConnectionIdRef<'a> {
cid: &'a [u8],
}
impl<'a> ::std::fmt::Debug for ConnectionIdRef<'a> {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(f, "CID {}", hex_with_len(&self.cid))
}
}
impl<'a> ::std::fmt::Display for ConnectionIdRef<'a> {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(f, "{}", hex(&self.cid))
}
}
impl<'a> From<&'a [u8]> for ConnectionIdRef<'a> {
fn from(cid: &'a [u8]) -> Self {
Self { cid }
}
}
impl<'a> std::ops::Deref for ConnectionIdRef<'a> {
type Target = [u8];
fn deref(&self) -> &Self::Target {
&self.cid
}
}
impl<'a> PartialEq<ConnectionId> for ConnectionIdRef<'a> {
fn eq(&self, other: &ConnectionId) -> bool {
self.cid == &other.cid[..]
}
}
pub trait ConnectionIdDecoder {
fn decode_cid<'a>(&self, dec: &mut Decoder<'a>) -> Option<ConnectionIdRef<'a>>;
}
pub trait ConnectionIdManager: ConnectionIdDecoder {
fn generate_cid(&mut self) -> ConnectionId;
fn as_decoder(&self) -> &dyn ConnectionIdDecoder;
}
#[cfg(test)]
mod tests {
use super::*;
use test_fixture::fixture_init;
#[test]
fn generate_initial_cid() {
fixture_init();
for _ in 0..100 {
let cid = ConnectionId::generate_initial();
if !matches!(cid.len(), 8..=MAX_CONNECTION_ID_LEN) {
panic!("connection ID {:?}", cid);
}
}
}
}
|
