tokio_quiche/http3/driver/
datagram.rs

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26
27use super::InboundFrame;
28use crate::buf_factory::BufFactory;
29use crate::buf_factory::PooledDgram;
30use crate::quic::QuicheConnection;
31use quiche::h3::NameValue;
32use quiche::h3::{
33    self,
34};
35
36/// Extracts the DATAGRAM flow ID proxied over the given `stream_id`,
37/// or `None` if this is not a proxy request.
38pub(crate) fn extract_flow_id(
39    stream_id: u64, headers: &[h3::Header],
40) -> Option<u64> {
41    let mut method = None;
42    let mut datagram_flow_id: Option<u64> = None;
43    let mut protocol = None;
44
45    for header in headers {
46        match header.name() {
47            b":method" => method = Some(header.value()),
48            b":protocol" => protocol = Some(header.value()),
49            b"datagram-flow-id" =>
50                datagram_flow_id = std::str::from_utf8(header.value())
51                    .ok()
52                    .and_then(|v| v.parse().ok()),
53            _ => {},
54        };
55
56        // We have all of the information needed to get a flow_id or
57        // quarter_stream_id
58        if method.is_some() && (datagram_flow_id.is_some() || protocol.is_some())
59        {
60            break;
61        }
62    }
63
64    // draft-ietf-masque-connect-udp-03 CONNECT-UDP
65    if method == Some(b"CONNECT-UDP") && datagram_flow_id.is_some() {
66        datagram_flow_id
67    // RFC 9298 CONNECT-UDP
68    } else if method == Some(b"CONNECT") && protocol.is_some() {
69        // we use the quarter_stream_id for RFC 9297
70        // https://www.rfc-editor.org/rfc/rfc9297.html#name-http-3-datagrams
71        Some(stream_id / 4)
72    } else {
73        None
74    }
75}
76
77/// Sends an HTTP/3 datagram over the QUIC connection with the given `flow_id`.
78pub(crate) fn send_h3_dgram(
79    conn: &mut QuicheConnection, flow_id: u64, mut dgram: PooledDgram,
80) -> quiche::Result<()> {
81    let mut prefix = [0u8; 8];
82    let mut buf = octets::OctetsMut::with_slice(&mut prefix);
83    let flow_id = buf.put_varint(flow_id)?;
84
85    if dgram.add_prefix(flow_id) {
86        conn.dgram_send(&dgram)
87    } else {
88        let mut inner = dgram.into_inner().into_vec();
89        inner.splice(..0, flow_id.iter().copied());
90        conn.dgram_send_vec(inner)
91    }
92}
93
94/// Reads the next HTTP/3 datagram from the QUIC connection.
95///
96/// [`quiche::Error::Done`] is returned if there is no datagram to read.
97pub(crate) fn receive_h3_dgram(
98    conn: &mut QuicheConnection,
99) -> quiche::Result<(u64, InboundFrame)> {
100    let dgram = conn.dgram_recv_vec()?;
101    let mut buf = octets::Octets::with_slice(&dgram);
102    let flow_id = buf.get_varint()?;
103    let advance = buf.off();
104    let datagram =
105        InboundFrame::Datagram(BufFactory::dgram_from_slice(&dgram[advance..]));
106
107    Ok((flow_id, datagram))
108}
tokio_quiche/http3/driver/datagram.rs

tokio_quiche/http3/driver/
datagram.rs
