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    ///
70    /// The fields are:
71    /// - The path ID for which the identifiers are needed.
72    /// - The time when the identifiers were needed, not used to generate the CIDs but sent
73    ///   back via the [`ConnectionEventInner::NewIdentifiers`] so the connection can track
74    ///   the lifetime of when it needs to be rotated.  should be rotated.
75    /// - The number of CIDs needed.
76    NeedIdentifiers(PathId, Instant, u64),
77    /// Retire a locally issued CID
78    ///
79    /// Stop routing connection ID for this sequence number to the connection
80    /// When `bool == true`, a new connection ID will be issued to peer
81    RetireConnectionId(Instant, PathId, u64, bool),
82}
83
84/// Protocol-level identifier for a connection.
85///
86/// Mainly useful for identifying this connection's packets on the wire with tools like Wireshark.
87#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
88#[cfg_attr(test, derive(test_strategy::Arbitrary))]
89pub struct ConnectionId {
90    /// length of CID
91    #[cfg_attr(test, strategy(1u8..=MAX_CID_SIZE as u8))]
92    len: u8,
93    /// CID in byte array
94    bytes: [u8; MAX_CID_SIZE],
95}
96
97impl ConnectionId {
98    /// Construct cid from byte array
99    pub fn new(bytes: &[u8]) -> Self {
100        debug_assert!(bytes.len() <= MAX_CID_SIZE);
101        let mut res = Self {
102            len: bytes.len() as u8,
103            bytes: [0; MAX_CID_SIZE],
104        };
105        res.bytes[..bytes.len()].copy_from_slice(bytes);
106        res
107    }
108
109    /// Constructs cid by reading `len` bytes from a `Buf`
110    ///
111    /// Callers need to assure that `buf.remaining() >= len`
112    pub fn from_buf(buf: &mut (impl Buf + ?Sized), len: usize) -> Self {
113        debug_assert!(len <= MAX_CID_SIZE);
114        let mut res = Self {
115            len: len as u8,
116            bytes: [0; MAX_CID_SIZE],
117        };
118        buf.copy_to_slice(&mut res[..len]);
119        res
120    }
121
122    pub(crate) fn len(&self) -> usize {
123        self.len as usize
124    }
125
126    /// Decode from long header format
127    pub(crate) fn decode_long(buf: &mut impl Buf) -> Option<Self> {
128        let len = buf.get::<u8>().ok()? as usize;
129        match len > MAX_CID_SIZE || buf.remaining() < len {
130            false => Some(Self::from_buf(buf, len)),
131            true => None,
132        }
133    }
134
135    /// Encode in long header format
136    pub(crate) fn encode_long(&self, buf: &mut impl BufMut) {
137        buf.put_u8(self.len() as u8);
138        buf.put_slice(self);
139    }
140}
141
142impl ::std::ops::Deref for ConnectionId {
143    type Target = [u8];
144    fn deref(&self) -> &[u8] {
145        &self.bytes[0..self.len as usize]
146    }
147}
148
149impl ::std::ops::DerefMut for ConnectionId {
150    fn deref_mut(&mut self) -> &mut [u8] {
151        &mut self.bytes[0..self.len as usize]
152    }
153}
154
155impl fmt::Debug for ConnectionId {
156    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
157        self.bytes[0..self.len as usize].fmt(f)
158    }
159}
160
161impl fmt::Display for ConnectionId {
162    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
163        for byte in self.iter() {
164            write!(f, "{byte:02x}")?;
165        }
166        Ok(())
167    }
168}
169
170/// Explicit congestion notification codepoint
171#[repr(u8)]
172#[derive(Debug, Copy, Clone, Eq, PartialEq)]
173pub enum EcnCodepoint {
174    /// The ECT(0) codepoint, indicating that an endpoint is ECN-capable
175    Ect0 = 0b10,
176    /// The ECT(1) codepoint, indicating that an endpoint is ECN-capable
177    Ect1 = 0b01,
178    /// The CE codepoint, signalling that congestion was experienced
179    Ce = 0b11,
180}
181
182impl EcnCodepoint {
183    /// Create new object from the given bits
184    pub fn from_bits(x: u8) -> Option<Self> {
185        use EcnCodepoint::*;
186        Some(match x & 0b11 {
187            0b10 => Ect0,
188            0b01 => Ect1,
189            0b11 => Ce,
190            _ => {
191                return None;
192            }
193        })
194    }
195
196    /// Returns whether the codepoint is a CE, signalling that congestion was experienced
197    pub fn is_ce(self) -> bool {
198        matches!(self, Self::Ce)
199    }
200}
201
202#[derive(Debug, Copy, Clone)]
203pub(crate) struct IssuedCid {
204    pub(crate) path_id: PathId,
205    pub(crate) sequence: u64,
206    pub(crate) id: ConnectionId,
207    pub(crate) reset_token: ResetToken,
208}
noq_proto/shared.rs

noq_proto/
shared.rs
