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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

use crate::ProtocolId;
use p2p::{
    builder::MetaBuilder,
    service::{BlockingFlag, ProtocolHandle, ProtocolMeta},
    traits::ServiceProtocol,
};
use tokio_util::codec::length_delimited;

/// All supported protocols
///
/// The underlying network of CKB is flexible and complex. The flexibility lies in that it can support any number of protocols.
/// Therefore, it is also relatively complex. Now, CKB has a bunch of protocols open by default,
/// but not all protocols have to be open. In other words, if you want to interact with ckb nodes at the p2p layer,
/// you only need to implement a few core protocols.
///
/// Core protocol: identify/discovery/sync/relay
#[derive(Clone, Debug)]
pub enum SupportProtocols {
    /// Ping: as a health check for ping/pong
    Ping,
    /// Discovery: used to communicate with any node with any known node address,
    /// to build a robust network topology as much as possible.
    Discovery,
    /// Identify: the first protocol opened when the nodes are interconnected,
    /// used to obtain the features, versions, and observation addresses supported by the other node.
    ///
    /// [RFC](https://github.com/nervosnetwork/rfcs/blob/master/rfcs/0012-node-discovery/0012-node-discovery.md)
    Identify,
    /// Feeler: used to detect whether the address is valid.
    ///
    /// [RFC](https://github.com/nervosnetwork/rfcs/blob/v2020.01.15/rfcs/0007-scoring-system-and-network-security/0007-scoring-system-and-network-security.md#feeler-connection)
    /// [Eclipse Attacks on Bitcoin's Peer-to-Peer Network](https://cryptographylab.bitbucket.io/slides/Eclipse%20Attacks%20on%20Bitcoin%27s%20Peer-to-Peer%20Network.pdf)
    Feeler,
    /// Disconnect message: used to give the remote node a debug message when the node decides to disconnect.
    /// This message must be as quick as possible, otherwise the message may not be sent. So, use a separate protocol to support it.
    DisconnectMessage,
    /// Sync: ckb's main communication protocol for synchronize all blocks.
    ///
    /// [RFC](https://github.com/nervosnetwork/rfcs/blob/master/rfcs/0004-ckb-block-sync/0004-ckb-block-sync.md)
    Sync,
    /// Relay: ckb's main communication protocol for synchronizing latest transactions and blocks.
    ///
    /// [RFC](https://github.com/nervosnetwork/rfcs/blob/master/rfcs/0004-ckb-block-sync/0004-ckb-block-sync.md#new-block-announcement)
    Relay,
    /// Time: A protocol used for node pairing that warns if there is a large gap between the local time and the remote node.
    Time,
    /// Alert: A protocol reserved by the Nervos Foundation to publish network-wide announcements.
    /// Any information sent from the protocol is verified by multi-signature
    Alert,
}

impl SupportProtocols {
    /// Protocol id
    pub fn protocol_id(&self) -> ProtocolId {
        match self {
            SupportProtocols::Ping => 0,
            SupportProtocols::Discovery => 1,
            SupportProtocols::Identify => 2,
            SupportProtocols::Feeler => 3,
            SupportProtocols::DisconnectMessage => 4,
            SupportProtocols::Sync => 100,
            SupportProtocols::Relay => 101,
            SupportProtocols::Time => 102,
            SupportProtocols::Alert => 110,
        }
        .into()
    }

    /// Protocol name
    pub fn name(&self) -> String {
        match self {
            SupportProtocols::Ping => "/ckb/ping",
            SupportProtocols::Discovery => "/ckb/discovery",
            SupportProtocols::Identify => "/ckb/identify",
            SupportProtocols::Feeler => "/ckb/flr",
            SupportProtocols::DisconnectMessage => "/ckb/disconnectmsg",
            SupportProtocols::Sync => "/ckb/syn",
            SupportProtocols::Relay => "/ckb/rel",
            SupportProtocols::Time => "/ckb/tim",
            SupportProtocols::Alert => "/ckb/alt",
        }
        .to_owned()
    }

    /// Support versions
    pub fn support_versions(&self) -> Vec<String> {
        // we didn't invoke MetaBuilder#support_versions fn for these protocols (Ping/Discovery/Identify/Feeler/DisconnectMessage)
        // in previous code, so the default 0.0.1 value is used ( https://github.com/nervosnetwork/tentacle/blob/master/src/builder.rs#L312 )
        // have to keep 0.0.1 for compatibility...
        match self {
            SupportProtocols::Ping => vec!["0.0.1".to_owned()],
            SupportProtocols::Discovery => vec!["0.0.1".to_owned()],
            SupportProtocols::Identify => vec!["0.0.1".to_owned()],
            SupportProtocols::Feeler => vec!["0.0.1".to_owned()],
            SupportProtocols::DisconnectMessage => vec!["0.0.1".to_owned()],
            SupportProtocols::Sync => vec!["1".to_owned()],
            SupportProtocols::Relay => vec!["1".to_owned()],
            SupportProtocols::Time => vec!["1".to_owned()],
            SupportProtocols::Alert => vec!["1".to_owned()],
        }
    }

    /// Protocol message max length
    pub fn max_frame_length(&self) -> usize {
        match self {
            SupportProtocols::Ping => 1024,              // 1   KB
            SupportProtocols::Discovery => 512 * 1024,   // 512 KB
            SupportProtocols::Identify => 2 * 1024,      // 2   KB
            SupportProtocols::Feeler => 1024,            // 1   KB
            SupportProtocols::DisconnectMessage => 1024, // 1   KB
            SupportProtocols::Sync => 2 * 1024 * 1024,   // 2   MB
            SupportProtocols::Relay => 4 * 1024 * 1024,  // 4   MB
            SupportProtocols::Time => 1024,              // 1   KB
            SupportProtocols::Alert => 128 * 1024,       // 128 KB
        }
    }

    /// Blocking flag
    pub fn flag(&self) -> BlockingFlag {
        match self {
            SupportProtocols::Ping
            | SupportProtocols::Discovery
            | SupportProtocols::Identify
            | SupportProtocols::Feeler
            | SupportProtocols::DisconnectMessage
            | SupportProtocols::Time
            | SupportProtocols::Alert => {
                let mut no_blocking_flag = BlockingFlag::default();
                no_blocking_flag.disable_all();
                no_blocking_flag
            }
            SupportProtocols::Sync | SupportProtocols::Relay => {
                let mut blocking_recv_flag = BlockingFlag::default();
                blocking_recv_flag.disable_connected();
                blocking_recv_flag.disable_disconnected();
                blocking_recv_flag.disable_notify();
                blocking_recv_flag
            }
        }
    }

    /// Builder with service handle
    // a helper fn to build `ProtocolMeta`
    pub fn build_meta_with_service_handle<
        SH: FnOnce() -> ProtocolHandle<Box<dyn ServiceProtocol + Send + 'static + Unpin>>,
    >(
        self,
        service_handle: SH,
    ) -> ProtocolMeta {
        let meta_builder: MetaBuilder = self.into();
        meta_builder.service_handle(service_handle).build()
    }
}

impl Into<MetaBuilder> for SupportProtocols {
    fn into(self) -> MetaBuilder {
        let max_frame_length = self.max_frame_length();
        MetaBuilder::default()
            .id(self.protocol_id())
            .support_versions(self.support_versions())
            .flag(self.flag())
            .name(move |_| self.name())
            .codec(move || {
                Box::new(
                    length_delimited::Builder::new()
                        .max_frame_length(max_frame_length)
                        .new_codec(),
                )
            })
    }
}