1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

// Copyright 2023 litep2p developers
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Protocol-related defines.

use crate::{
    codec::ProtocolCodec,
    error::SubstreamError,
    substream::Substream,
    transport::Endpoint,
    types::{protocol::ProtocolName, SubstreamId},
    PeerId,
};

use multiaddr::Multiaddr;

use std::fmt::Debug;

pub(crate) use connection::Permit;
pub(crate) use protocol_set::{InnerTransportEvent, ProtocolCommand, ProtocolSet};

pub use transport_service::TransportService;

pub mod libp2p;
pub mod mdns;
pub mod notification;
pub mod request_response;

mod connection;
mod protocol_set;
mod transport_service;

/// Substream direction.
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub enum Direction {
    /// Substream was opened by the remote peer.
    Inbound,

    /// Substream was opened by the local peer.
    Outbound(SubstreamId),
}

/// Events emitted by one of the installed transports to protocol(s).
#[derive(Debug)]
pub enum TransportEvent {
    /// Connection established to `peer`.
    ConnectionEstablished {
        /// Peer ID.
        peer: PeerId,

        /// Endpoint.
        endpoint: Endpoint,
    },

    /// Connection closed to peer.
    ConnectionClosed {
        /// Peer ID.
        peer: PeerId,
    },

    /// Failed to dial peer.
    ///
    /// This is reported to that protocol which initiated the connection.
    DialFailure {
        /// Peer ID.
        peer: PeerId,

        /// Dialed address.
        address: Multiaddr,
    },

    /// Substream opened for `peer`.
    SubstreamOpened {
        /// Peer ID.
        peer: PeerId,

        /// Protocol name.
        ///
        /// One protocol handler may handle multiple sub-protocols (such as `/ipfs/identify/1.0.0`
        /// and `/ipfs/identify/push/1.0.0`) or it may have aliases which should be handled by
        /// the same protocol handler. When the substream is sent from transport to the protocol
        /// handler, the protocol name that was used to negotiate the substream is also sent so
        /// the protocol can handle the substream appropriately.
        protocol: ProtocolName,

        /// Fallback protocol.
        fallback: Option<ProtocolName>,

        /// Substream direction.
        ///
        /// Informs the protocol whether the substream is inbound (opened by the remote node)
        /// or outbound (opened by the local node). This allows the protocol to distinguish
        /// between the two types of substreams and execute correct code for the substream.
        ///
        /// Outbound substreams also contain the substream ID which allows the protocol to
        /// distinguish between different outbound substreams.
        direction: Direction,

        /// Substream.
        substream: Substream,
    },

    /// Failed to open substream.
    ///
    /// Substream open failures are reported only for outbound substreams.
    SubstreamOpenFailure {
        /// Substream ID.
        substream: SubstreamId,

        /// Error that occurred when the substream was being opened.
        error: SubstreamError,
    },
}

/// Trait defining the interface for a user protocol.
#[async_trait::async_trait]
pub trait UserProtocol: Send {
    /// Get user protocol name.
    fn protocol(&self) -> ProtocolName;

    /// Get user protocol codec.
    fn codec(&self) -> ProtocolCodec;

    /// Start the the user protocol event loop.
    async fn run(self: Box<Self>, service: TransportService) -> crate::Result<()>;
}