noq_proto/
shared.rs

1use std::{fmt, net::SocketAddr};
2
3use bytes::{Buf, BufMut, BytesMut};
4
5use crate::FourTuple;
6use crate::PathId;
7use crate::{Duration, Instant, MAX_CID_SIZE, ResetToken, coding::BufExt, packet::PartialDecode};
8
9/// Events sent from an Endpoint to a Connection
10#[derive(Debug)]
11pub struct ConnectionEvent(pub(crate) ConnectionEventInner);
12
13#[derive(Debug)]
14pub(crate) enum ConnectionEventInner {
15    /// A datagram has been received for the Connection
16    Datagram(DatagramConnectionEvent),
17    /// New connection identifiers have been issued for the Connection
18    NewIdentifiers(Vec<IssuedCid>, Instant, usize, Option<Duration>),
19}
20
21/// Variant of [`ConnectionEventInner`].
22#[derive(Debug)]
23pub(crate) struct DatagramConnectionEvent {
24    pub(crate) now: Instant,
25    pub(crate) network_path: FourTuple,
26    pub(crate) path_id: PathId,
27    pub(crate) ecn: Option<EcnCodepoint>,
28    pub(crate) first_decode: PartialDecode,
29    pub(crate) remaining: Option<BytesMut>,
30}
31
32/// Events sent from a Connection to an Endpoint
33#[derive(Debug)]
34pub struct EndpointEvent(pub(crate) EndpointEventInner);
35
36impl EndpointEvent {
37    /// Construct an event that indicating that a `Connection` will no longer emit events
38    ///
39    /// Useful for notifying an `Endpoint` that a `Connection` has been destroyed outside of the
40    /// usual state machine flow, e.g. when being dropped by the user.
41    pub fn drained() -> Self {
42        Self(EndpointEventInner::Drained)
43    }
44
45    /// Determine whether this is the last event a `Connection` will emit
46    ///
47    /// Useful for determining when connection-related event loop state can be freed.
48    pub fn is_drained(&self) -> bool {
49        self.0 == EndpointEventInner::Drained
50    }
51}
52
53#[derive(Clone, Debug, Eq, PartialEq)]
54pub(crate) enum EndpointEventInner {
55    /// The connection has been drained
56    Drained,
57    /// The connection has a new active reset token
58    ///
59    /// Whenever the connection switches to a new remote CID issued by the peer, it also
60    /// switches the matching reset token that can be used to abort this connection. This
61    /// event provides a new reset token for the active remote CID.
62    ResetToken(PathId, SocketAddr, ResetToken),
63    /// Retire the remotely issued reset token for a path, without replacing it with a new one
64    ///
65    /// This is like `ResetToken` above, but without replacing the `ResetToken` with a new
66    /// one. See `ConnectionIndex::connection_reset_tokens`.
67    RetireResetToken(PathId),
68    /// The connection needs connection identifiers
69    NeedIdentifiers(PathId, Instant, u64),
70    /// Retire a locally issued CID
71    ///
72    /// Stop routing connection ID for this sequence number to the connection
73    /// When `bool == true`, a new connection ID will be issued to peer
74    RetireConnectionId(Instant, PathId, u64, bool),
75}
76
77/// Protocol-level identifier for a connection.
78///
79/// Mainly useful for identifying this connection's packets on the wire with tools like Wireshark.
80#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
81#[cfg_attr(test, derive(test_strategy::Arbitrary))]
82pub struct ConnectionId {
83    /// length of CID
84    #[cfg_attr(test, strategy(1u8..=MAX_CID_SIZE as u8))]
85    len: u8,
86    /// CID in byte array
87    bytes: [u8; MAX_CID_SIZE],
88}
89
90impl ConnectionId {
91    /// Construct cid from byte array
92    pub fn new(bytes: &[u8]) -> Self {
93        debug_assert!(bytes.len() <= MAX_CID_SIZE);
94        let mut res = Self {
95            len: bytes.len() as u8,
96            bytes: [0; MAX_CID_SIZE],
97        };
98        res.bytes[..bytes.len()].copy_from_slice(bytes);
99        res
100    }
101
102    /// Constructs cid by reading `len` bytes from a `Buf`
103    ///
104    /// Callers need to assure that `buf.remaining() >= len`
105    pub fn from_buf(buf: &mut (impl Buf + ?Sized), len: usize) -> Self {
106        debug_assert!(len <= MAX_CID_SIZE);
107        let mut res = Self {
108            len: len as u8,
109            bytes: [0; MAX_CID_SIZE],
110        };
111        buf.copy_to_slice(&mut res[..len]);
112        res
113    }
114
115    pub(crate) fn len(&self) -> usize {
116        self.len as usize
117    }
118
119    /// Decode from long header format
120    pub(crate) fn decode_long(buf: &mut impl Buf) -> Option<Self> {
121        let len = buf.get::<u8>().ok()? as usize;
122        match len > MAX_CID_SIZE || buf.remaining() < len {
123            false => Some(Self::from_buf(buf, len)),
124            true => None,
125        }
126    }
127
128    /// Encode in long header format
129    pub(crate) fn encode_long(&self, buf: &mut impl BufMut) {
130        buf.put_u8(self.len() as u8);
131        buf.put_slice(self);
132    }
133}
134
135impl ::std::ops::Deref for ConnectionId {
136    type Target = [u8];
137    fn deref(&self) -> &[u8] {
138        &self.bytes[0..self.len as usize]
139    }
140}
141
142impl ::std::ops::DerefMut for ConnectionId {
143    fn deref_mut(&mut self) -> &mut [u8] {
144        &mut self.bytes[0..self.len as usize]
145    }
146}
147
148impl fmt::Debug for ConnectionId {
149    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
150        self.bytes[0..self.len as usize].fmt(f)
151    }
152}
153
154impl fmt::Display for ConnectionId {
155    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
156        for byte in self.iter() {
157            write!(f, "{byte:02x}")?;
158        }
159        Ok(())
160    }
161}
162
163/// Explicit congestion notification codepoint
164#[repr(u8)]
165#[derive(Debug, Copy, Clone, Eq, PartialEq)]
166pub enum EcnCodepoint {
167    /// The ECT(0) codepoint, indicating that an endpoint is ECN-capable
168    Ect0 = 0b10,
169    /// The ECT(1) codepoint, indicating that an endpoint is ECN-capable
170    Ect1 = 0b01,
171    /// The CE codepoint, signalling that congestion was experienced
172    Ce = 0b11,
173}
174
175impl EcnCodepoint {
176    /// Create new object from the given bits
177    pub fn from_bits(x: u8) -> Option<Self> {
178        use EcnCodepoint::*;
179        Some(match x & 0b11 {
180            0b10 => Ect0,
181            0b01 => Ect1,
182            0b11 => Ce,
183            _ => {
184                return None;
185            }
186        })
187    }
188
189    /// Returns whether the codepoint is a CE, signalling that congestion was experienced
190    pub fn is_ce(self) -> bool {
191        matches!(self, Self::Ce)
192    }
193}
194
195#[derive(Debug, Copy, Clone)]
196pub(crate) struct IssuedCid {
197    pub(crate) path_id: PathId,
198    pub(crate) sequence: u64,
199    pub(crate) id: ConnectionId,
200    pub(crate) reset_token: ResetToken,
201}
noq_proto/shared.rs

noq_proto/
shared.rs
