quinn_proto/
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}
62
63/// Protocol-level identifier for a connection.
64///
65/// Mainly useful for identifying this connection's packets on the wire with tools like Wireshark.
66#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
67pub struct ConnectionId {
68    /// length of CID
69    len: u8,
70    /// CID in byte array
71    bytes: [u8; MAX_CID_SIZE],
72}
73
74impl ConnectionId {
75    /// Construct cid from byte array
76    pub fn new(bytes: &[u8]) -> Self {
77        debug_assert!(bytes.len() <= MAX_CID_SIZE);
78        let mut res = Self {
79            len: bytes.len() as u8,
80            bytes: [0; MAX_CID_SIZE],
81        };
82        res.bytes[..bytes.len()].copy_from_slice(bytes);
83        res
84    }
85
86    /// Constructs cid by reading `len` bytes from a `Buf`
87    ///
88    /// Callers need to assure that `buf.remaining() >= len`
89    pub fn from_buf(buf: &mut (impl Buf + ?Sized), len: usize) -> Self {
90        debug_assert!(len <= MAX_CID_SIZE);
91        let mut res = Self {
92            len: len as u8,
93            bytes: [0; MAX_CID_SIZE],
94        };
95        buf.copy_to_slice(&mut res[..len]);
96        res
97    }
98
99    /// Decode from long header format
100    pub(crate) fn decode_long(buf: &mut impl Buf) -> Option<Self> {
101        let len = buf.get::<u8>().ok()? as usize;
102        match len > MAX_CID_SIZE || buf.remaining() < len {
103            false => Some(Self::from_buf(buf, len)),
104            true => None,
105        }
106    }
107
108    /// Encode in long header format
109    pub(crate) fn encode_long(&self, buf: &mut impl BufMut) {
110        buf.put_u8(self.len() as u8);
111        buf.put_slice(self);
112    }
113}
114
115impl ::std::ops::Deref for ConnectionId {
116    type Target = [u8];
117    fn deref(&self) -> &[u8] {
118        &self.bytes[0..self.len as usize]
119    }
120}
121
122impl ::std::ops::DerefMut for ConnectionId {
123    fn deref_mut(&mut self) -> &mut [u8] {
124        &mut self.bytes[0..self.len as usize]
125    }
126}
127
128impl fmt::Debug for ConnectionId {
129    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
130        self.bytes[0..self.len as usize].fmt(f)
131    }
132}
133
134impl fmt::Display for ConnectionId {
135    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
136        for byte in self.iter() {
137            write!(f, "{byte:02x}")?;
138        }
139        Ok(())
140    }
141}
142
143/// Explicit congestion notification codepoint
144#[repr(u8)]
145#[derive(Debug, Copy, Clone, Eq, PartialEq)]
146pub enum EcnCodepoint {
147    /// The ECT(0) codepoint, indicating that an endpoint is ECN-capable
148    Ect0 = 0b10,
149    /// The ECT(1) codepoint, indicating that an endpoint is ECN-capable
150    Ect1 = 0b01,
151    /// The CE codepoint, signalling that congestion was experienced
152    Ce = 0b11,
153}
154
155impl EcnCodepoint {
156    /// Create new object from the given bits
157    pub fn from_bits(x: u8) -> Option<Self> {
158        use EcnCodepoint::*;
159        Some(match x & 0b11 {
160            0b10 => Ect0,
161            0b01 => Ect1,
162            0b11 => Ce,
163            _ => {
164                return None;
165            }
166        })
167    }
168
169    /// Returns whether the codepoint is a CE, signalling that congestion was experienced
170    pub fn is_ce(self) -> bool {
171        matches!(self, Self::Ce)
172    }
173}
174
175#[derive(Debug, Copy, Clone)]
176pub(crate) struct IssuedCid {
177    pub(crate) sequence: u64,
178    pub(crate) id: ConnectionId,
179    pub(crate) reset_token: ResetToken,
180}
quinn_proto/shared.rs

quinn_proto/
shared.rs
