prns-core 0.3.4

Pure Reticulum engine and wire contract for Personal Reticulum
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

#[cfg(feature = "runtime-metrics")]
use crate::engine::AnnounceOrigin;
use crate::engine::{
    Directive, EngineReaction, EngineState, InstantMillis, PathRequestIdBytes, ReemitAnnounce,
};
use crate::interfaces::{AttachedInterfaces, InterfaceId, InterfaceKind};
use crate::routing::path_requests::write_path_request_wire_packet;
use crate::storage::StorageLayout;
use crate::wire::{DestinationHash, BROADCAST_MTU};

#[derive(Clone, Copy)]
pub(super) enum RelayAudience {
    Transports,
    OnlineTransports,
    BoundaryAndGateway,
    LocalClients,
}

pub(super) struct RelayPathRequest<'a> {
    pub(super) destination: DestinationHash,
    pub(super) id: &'a PathRequestIdBytes,
}

impl<S: StorageLayout> EngineState<S> {
    pub(super) fn relay_path_request(
        &mut self,
        request: RelayPathRequest<'_>,
        source: InterfaceId,
        interfaces: AttachedInterfaces<'_>,
        audience: RelayAudience,
        now: InstantMillis,
        sink: &mut impl FnMut(EngineReaction<'_>),
    ) {
        let mut buf = [0u8; BROADCAST_MTU];
        let transport_id = self
            .network_transport_enabled()
            .then(|| self.transport_id())
            .flatten();
        let Ok(wire_bytes) =
            write_path_request_wire_packet(request.destination, transport_id, request.id, &mut buf)
        else {
            return;
        };
        for descriptor in interfaces {
            let in_audience = match audience {
                RelayAudience::Transports | RelayAudience::OnlineTransports => true,
                RelayAudience::BoundaryAndGateway => matches!(
                    descriptor.mode,
                    crate::interfaces::InterfaceMode::Boundary
                        | crate::interfaces::InterfaceMode::Gateway
                ),
                RelayAudience::LocalClients => {
                    descriptor.id.kind() == Some(InterfaceKind::LocalClient)
                }
            };
            if in_audience && descriptor.id != source && descriptor.capabilities.allows_transmit() {
                if !matches!(audience, RelayAudience::LocalClients)
                    && self.egress_path_request_limits.should_egress_limit(
                        descriptor.id,
                        now,
                        descriptor.common.path_request_egress,
                    )
                {
                    continue;
                }
                match audience {
                    RelayAudience::OnlineTransports | RelayAudience::BoundaryAndGateway => {
                        let mut record_egress = || {
                            self.egress_path_request_limits
                                .record_egress(descriptor.id, now);
                        };
                        sink(EngineReaction::Directive(Directive::SendIfOnline {
                            target: descriptor.id,
                            bytes: &buf[..wire_bytes],
                            on_send: &mut record_egress,
                        }));
                    }
                    RelayAudience::Transports => {
                        self.egress_path_request_limits
                            .record_egress(descriptor.id, now);
                        sink(EngineReaction::Directive(Directive::Send {
                            target: descriptor.id,
                            bytes: &buf[..wire_bytes],
                        }));
                    }
                    RelayAudience::LocalClients => {
                        sink(EngineReaction::Directive(Directive::Send {
                            target: descriptor.id,
                            bytes: &buf[..wire_bytes],
                        }))
                    }
                }
            }
        }
    }

    pub(super) fn relay_announce_to_local_clients(
        &self,
        destination: DestinationHash,
        hops: u8,
        source: InterfaceId,
        interfaces: AttachedInterfaces<'_>,
        sink: &mut impl FnMut(EngineReaction<'_>),
    ) {
        let Some(via) = self.transport_id() else {
            return;
        };
        let Some(stored) = self.routing_table.stored_announce_for(&destination) else {
            return;
        };
        let mut buf = [0u8; BROADCAST_MTU];
        let relay = ReemitAnnounce {
            announce: stored.announce.clone(),
            emit_hops: hops,
            via,
            target: source,
            is_path_response: false,
        };
        let Ok(written) = relay.to_wire(&mut buf) else {
            return;
        };
        for descriptor in interfaces {
            if descriptor.id == source
                || descriptor.id.kind() != Some(InterfaceKind::LocalClient)
                || !descriptor.capabilities.allows_transmit()
            {
                continue;
            }
            sink(EngineReaction::Directive(Directive::SendAnnounce {
                target: descriptor.id,
                bytes: &buf[..written],
                hops,
                #[cfg(feature = "runtime-metrics")]
                origin: if source.kind() == Some(InterfaceKind::LocalClient) {
                    AnnounceOrigin::SharedClient
                } else {
                    AnnounceOrigin::Relay
                },
            }));
        }
    }
}