libp2p_dcutr/protocol/
outbound.rs

1// Copyright 2021 Protocol Labs.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a
4// copy of this software and associated documentation files (the "Software"),
5// to deal in the Software without restriction, including without limitation
6// the rights to use, copy, modify, merge, publish, distribute, sublicense,
7// and/or sell copies of the Software, and to permit persons to whom the
8// Software is furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
14// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
19// DEALINGS IN THE SOFTWARE.
20
21use std::io;
22
23use asynchronous_codec::Framed;
24use futures::prelude::*;
25use futures_timer::Delay;
26use libp2p_core::{multiaddr::Protocol, Multiaddr};
27use libp2p_swarm::Stream;
28use thiserror::Error;
29use web_time::Instant;
30
31use crate::{proto, PROTOCOL_NAME};
32
33pub(crate) async fn handshake(
34    stream: Stream,
35    candidates: Vec<Multiaddr>,
36) -> Result<Vec<Multiaddr>, Error> {
37    let mut stream = Framed::new(
38        stream,
39        quick_protobuf_codec::Codec::new(super::MAX_MESSAGE_SIZE_BYTES),
40    );
41
42    let msg = proto::HolePunch {
43        type_pb: proto::Type::CONNECT,
44        ObsAddrs: candidates.into_iter().map(|a| a.to_vec()).collect(),
45    };
46
47    stream.send(msg).await?;
48
49    let sent_time = Instant::now();
50
51    let proto::HolePunch { type_pb, ObsAddrs } = stream
52        .next()
53        .await
54        .ok_or(io::Error::from(io::ErrorKind::UnexpectedEof))??;
55
56    let rtt = sent_time.elapsed();
57
58    if !matches!(type_pb, proto::Type::CONNECT) {
59        return Err(Error::Protocol(ProtocolViolation::UnexpectedTypeSync));
60    }
61
62    if ObsAddrs.is_empty() {
63        return Err(Error::Protocol(ProtocolViolation::NoAddresses));
64    }
65
66    let obs_addrs = ObsAddrs
67        .into_iter()
68        .filter_map(|a| match Multiaddr::try_from(a.to_vec()) {
69            Ok(a) => Some(a),
70            Err(e) => {
71                tracing::debug!("Unable to parse multiaddr: {e}");
72                None
73            }
74        })
75        // Filter out relayed addresses.
76        .filter(|a| {
77            if a.iter().any(|p| p == Protocol::P2pCircuit) {
78                tracing::debug!(address=%a, "Dropping relayed address");
79                false
80            } else {
81                true
82            }
83        })
84        .collect();
85
86    let msg = proto::HolePunch {
87        type_pb: proto::Type::SYNC,
88        ObsAddrs: vec![],
89    };
90
91    stream.send(msg).await?;
92
93    Delay::new(rtt / 2).await;
94
95    Ok(obs_addrs)
96}
97
98#[derive(Debug, Error)]
99pub enum Error {
100    #[error("IO error")]
101    Io(#[from] io::Error),
102    #[error("Remote does not support the `{PROTOCOL_NAME}` protocol")]
103    Unsupported,
104    #[error("Protocol error")]
105    Protocol(#[from] ProtocolViolation),
106}
107
108impl From<quick_protobuf_codec::Error> for Error {
109    fn from(e: quick_protobuf_codec::Error) -> Self {
110        Error::Protocol(ProtocolViolation::Codec(e))
111    }
112}
113
114#[derive(Debug, Error)]
115pub enum ProtocolViolation {
116    #[error(transparent)]
117    Codec(#[from] quick_protobuf_codec::Error),
118    #[error("Expected 'status' field to be set.")]
119    MissingStatusField,
120    #[error("Expected 'reservation' field to be set.")]
121    MissingReservationField,
122    #[error("Expected at least one address in reservation.")]
123    NoAddresses,
124    #[error("Invalid expiration timestamp in reservation.")]
125    InvalidReservationExpiration,
126    #[error("Failed to parse response type field.")]
127    ParseTypeField,
128    #[error("Unexpected message type 'connect'")]
129    UnexpectedTypeConnect,
130    #[error("Unexpected message type 'sync'")]
131    UnexpectedTypeSync,
132    #[error("Failed to parse response type field.")]
133    ParseStatusField,
134}
libp2p_dcutr/protocol/outbound.rs

libp2p_dcutr/protocol/
outbound.rs
