ant_quic/
shared.rs

1use std::{fmt, net::SocketAddr};
2
3use bytes::{Buf, BufMut, BytesMut};
4
5use crate::{Instant, MAX_CID_SIZE, ResetToken, coding::BufExt, packet::PartialDecode};
6
7/// Events sent from an Endpoint to a Connection
8#[derive(Debug)]
9pub struct ConnectionEvent(pub(crate) ConnectionEventInner);
10
11#[derive(Debug)]
12pub(crate) enum ConnectionEventInner {
13    /// A datagram has been received for the Connection
14    Datagram(DatagramConnectionEvent),
15    /// New connection identifiers have been issued for the Connection
16    NewIdentifiers(Vec<IssuedCid>, Instant),
17}
18
19/// Variant of [`ConnectionEventInner`].
20#[derive(Debug)]
21pub(crate) struct DatagramConnectionEvent {
22    pub(crate) now: Instant,
23    pub(crate) remote: SocketAddr,
24    pub(crate) ecn: Option<EcnCodepoint>,
25    pub(crate) first_decode: PartialDecode,
26    pub(crate) remaining: Option<BytesMut>,
27}
28
29/// Events sent from a Connection to an Endpoint
30#[derive(Debug)]
31pub struct EndpointEvent(pub(crate) EndpointEventInner);
32
33impl EndpointEvent {
34    /// Construct an event that indicating that a `Connection` will no longer emit events
35    ///
36    /// Useful for notifying an `Endpoint` that a `Connection` has been destroyed outside of the
37    /// usual state machine flow, e.g. when being dropped by the user.
38    pub fn drained() -> Self {
39        Self(EndpointEventInner::Drained)
40    }
41
42    /// Determine whether this is the last event a `Connection` will emit
43    ///
44    /// Useful for determining when connection-related event loop state can be freed.
45    pub fn is_drained(&self) -> bool {
46        self.0 == EndpointEventInner::Drained
47    }
48}
49
50#[derive(Clone, Debug, Eq, PartialEq)]
51pub(crate) enum EndpointEventInner {
52    /// The connection has been drained
53    Drained,
54    /// The reset token and/or address eligible for generating resets has been updated
55    ResetToken(SocketAddr, ResetToken),
56    /// The connection needs connection identifiers
57    NeedIdentifiers(Instant, u64),
58    /// Stop routing connection ID for this sequence number to the connection
59    /// When `bool == true`, a new connection ID will be issued to peer
60    RetireConnectionId(Instant, u64, bool),
61    /// Request to relay a PunchMeNow frame to a target peer
62    RelayPunchMeNow([u8; 32], crate::frame::PunchMeNow),
63    /// Request to send an AddAddress frame to the peer
64    SendAddressFrame(crate::frame::AddAddress),
65    /// NAT traversal candidate validation succeeded
66    NatCandidateValidated { address: SocketAddr, challenge: u64 },
67}
68
69/// Protocol-level identifier for a connection.
70///
71/// Mainly useful for identifying this connection's packets on the wire with tools like Wireshark.
72#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
73pub struct ConnectionId {
74    /// length of CID
75    len: u8,
76    /// CID in byte array
77    bytes: [u8; MAX_CID_SIZE],
78}
79
80impl ConnectionId {
81    /// Construct cid from byte array
82    pub fn new(bytes: &[u8]) -> Self {
83        debug_assert!(bytes.len() <= MAX_CID_SIZE);
84        let mut res = Self {
85            len: bytes.len() as u8,
86            bytes: [0; MAX_CID_SIZE],
87        };
88        res.bytes[..bytes.len()].copy_from_slice(bytes);
89        res
90    }
91
92    /// Constructs cid by reading `len` bytes from a `Buf`
93    ///
94    /// Callers need to assure that `buf.remaining() >= len`
95    pub fn from_buf(buf: &mut (impl Buf + ?Sized), len: usize) -> Self {
96        debug_assert!(len <= MAX_CID_SIZE);
97        let mut res = Self {
98            len: len as u8,
99            bytes: [0; MAX_CID_SIZE],
100        };
101        buf.copy_to_slice(&mut res[..len]);
102        res
103    }
104
105    /// Decode from long header format
106    pub(crate) fn decode_long(buf: &mut impl Buf) -> Option<Self> {
107        let len = buf.get::<u8>().ok()? as usize;
108        match len > MAX_CID_SIZE || buf.remaining() < len {
109            false => Some(Self::from_buf(buf, len)),
110            true => None,
111        }
112    }
113
114    /// Encode in long header format
115    pub(crate) fn encode_long(&self, buf: &mut impl BufMut) {
116        buf.put_u8(self.len() as u8);
117        buf.put_slice(self);
118    }
119}
120
121impl ::std::ops::Deref for ConnectionId {
122    type Target = [u8];
123    fn deref(&self) -> &[u8] {
124        &self.bytes[0..self.len as usize]
125    }
126}
127
128impl ::std::ops::DerefMut for ConnectionId {
129    fn deref_mut(&mut self) -> &mut [u8] {
130        &mut self.bytes[0..self.len as usize]
131    }
132}
133
134impl fmt::Debug for ConnectionId {
135    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
136        self.bytes[0..self.len as usize].fmt(f)
137    }
138}
139
140impl fmt::Display for ConnectionId {
141    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
142        for byte in self.iter() {
143            write!(f, "{byte:02x}")?;
144        }
145        Ok(())
146    }
147}
148
149/// Explicit congestion notification codepoint
150#[repr(u8)]
151#[derive(Debug, Copy, Clone, Eq, PartialEq)]
152pub enum EcnCodepoint {
153    /// The ECT(0) codepoint, indicating that an endpoint is ECN-capable
154    Ect0 = 0b10,
155    /// The ECT(1) codepoint, indicating that an endpoint is ECN-capable
156    Ect1 = 0b01,
157    /// The CE codepoint, signalling that congestion was experienced
158    Ce = 0b11,
159}
160
161impl EcnCodepoint {
162    /// Create new object from the given bits
163    pub fn from_bits(x: u8) -> Option<Self> {
164        use EcnCodepoint::*;
165        Some(match x & 0b11 {
166            0b10 => Ect0,
167            0b01 => Ect1,
168            0b11 => Ce,
169            _ => {
170                return None;
171            }
172        })
173    }
174
175    /// Returns whether the codepoint is a CE, signalling that congestion was experienced
176    pub fn is_ce(self) -> bool {
177        matches!(self, Self::Ce)
178    }
179}
180
181#[derive(Debug, Copy, Clone)]
182pub(crate) struct IssuedCid {
183    pub(crate) sequence: u64,
184    pub(crate) id: ConnectionId,
185    pub(crate) reset_token: ResetToken,
186}
ant_quic/shared.rs

ant_quic/
shared.rs
