dyns 0.4.0

DNS discovery and resolver support for DHTTP applications
Documentation 
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

use dhttp_identity::certificate::CertificateChainKey;
use dquic::qbase::net::addr::EndpointAddr as DquicEndpointAddr;

use crate::core::parser::record::endpoint::EndpointAddr as DnsEndpointAddr;

type TaggedEndpoint<T> = (T, DquicEndpointAddr);
type EndpointGroup<T> = (CertificateChainKey, Vec<TaggedEndpoint<T>>);

pub(crate) fn selected_endpoint_addrs(
    records: impl IntoIterator<Item = DnsEndpointAddr>,
) -> Vec<DquicEndpointAddr> {
    selected_endpoint_records(records.into_iter().map(|record| ((), record)))
        .into_iter()
        .map(|((), endpoint)| endpoint)
        .collect()
}

pub(crate) fn selected_endpoint_records<T>(
    records: impl IntoIterator<Item = (T, DnsEndpointAddr)>,
) -> Vec<(T, DquicEndpointAddr)> {
    let mut groups: Vec<EndpointGroup<T>> = Vec::new();

    for (tag, record) in records {
        let chain_key = record.certificate_chain_key();
        let Ok(endpoint) = DquicEndpointAddr::try_from(record) else {
            continue;
        };

        if let Some((_key, endpoints)) = groups.iter_mut().find(|(key, _)| *key == chain_key) {
            endpoints.push((tag, endpoint));
        } else {
            groups.push((chain_key, vec![(tag, endpoint)]));
        }
    }

    groups.sort_by_key(|(chain_key, _)| {
        let primary_rank = match chain_key.kind() {
            dhttp_identity::certificate::CertificateChainKind::Primary => 0,
            dhttp_identity::certificate::CertificateChainKind::Secondary => 1,
        };
        (primary_rank, chain_key.sequence().get())
    });

    groups
        .into_iter()
        .next()
        .map(|(_, endpoints)| endpoints)
        .unwrap_or_default()
}

#[cfg(test)]
mod tests {
    use dhttp_identity::certificate::CertificateSequence;

    use crate::core::parser::record::endpoint::EndpointAddr;

    fn direct(addr: &str, main: bool, sequence: u32) -> EndpointAddr {
        let mut endpoint = match addr.parse().unwrap() {
            std::net::SocketAddr::V4(addr) => EndpointAddr::direct_v4(addr),
            std::net::SocketAddr::V6(addr) => EndpointAddr::direct_v6(addr),
        };
        endpoint.set_main(main);
        endpoint.set_sequence(CertificateSequence::try_from(sequence).unwrap());
        endpoint
    }

    #[test]
    fn selected_endpoint_addrs_prefers_primary_chain_key_group() {
        let secondary = direct("192.0.2.20:4433", false, 0);
        let primary_a = direct("192.0.2.10:4433", true, 2);
        let primary_b = direct("192.0.2.11:4433", true, 2);

        let selected = super::selected_endpoint_addrs([secondary, primary_a, primary_b]);

        assert_eq!(selected.len(), 2);
        assert_eq!(
            selected[0],
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.10:4433".parse().unwrap())
        );
        assert_eq!(
            selected[1],
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.11:4433".parse().unwrap())
        );
    }

    #[test]
    fn selected_endpoint_addrs_uses_one_secondary_chain_key_group_when_no_primary_exists() {
        let secondary_a = direct("192.0.2.20:4433", false, 5);
        let secondary_b = direct("192.0.2.21:4433", false, 5);
        let other_secondary = direct("192.0.2.30:4433", false, 6);

        let selected = super::selected_endpoint_addrs([secondary_a, secondary_b, other_secondary]);

        assert_eq!(selected.len(), 2);
        assert_eq!(
            selected[0],
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.20:4433".parse().unwrap())
        );
        assert_eq!(
            selected[1],
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.21:4433".parse().unwrap())
        );
    }

    #[test]
    fn selected_endpoint_addrs_treats_missing_sequence_as_zero() {
        let mut first = direct("192.0.2.40:4433", true, 0);
        first.set_clustered(false);
        let second = direct("192.0.2.41:4433", true, 0);

        let selected = super::selected_endpoint_addrs([first, second]);

        assert_eq!(selected.len(), 2);
    }

    #[test]
    fn selected_endpoint_records_uses_one_chain_key_across_sources() {
        let selected = super::selected_endpoint_records([
            ("wifi", direct("192.0.2.50:4433", true, 3)),
            ("ethernet", direct("192.0.2.51:4433", true, 4)),
            ("wifi", direct("192.0.2.52:4433", true, 3)),
        ]);

        assert_eq!(selected.len(), 2);
        assert_eq!(selected[0].0, "wifi");
        assert_eq!(
            selected[0].1,
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.50:4433".parse().unwrap())
        );
        assert_eq!(selected[1].0, "wifi");
        assert_eq!(
            selected[1].1,
            dquic::qbase::net::addr::EndpointAddr::direct("192.0.2.52:4433".parse().unwrap())
        );
    }
}