turn/proto/
reqtrans.rs

1#[cfg(test)]
2mod reqtrans_test;
3
4use std::fmt;
5
6use stun::attributes::*;
7use stun::checks::*;
8use stun::message::*;
9
10use super::*;
11
12/// `RequestedTransport` represents `REQUESTED-TRANSPORT` attribute.
13///
14/// This attribute is used by the client to request a specific transport
15/// protocol for the allocated transport address. RFC 5766 only allows the use of
16/// codepoint 17 (User Datagram protocol).
17///
18/// [RFC 5766 Section 14.7](https://www.rfc-editor.org/rfc/rfc5766#section-14.7).
19#[derive(Default, Debug, PartialEq, Eq)]
20pub struct RequestedTransport {
21    pub protocol: Protocol,
22}
23
24impl fmt::Display for RequestedTransport {
25    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
26        write!(f, "protocol: {}", self.protocol)
27    }
28}
29
30const REQUESTED_TRANSPORT_SIZE: usize = 4;
31
32impl Setter for RequestedTransport {
33    /// Adds `REQUESTED-TRANSPORT` to message.
34    fn add_to(&self, m: &mut Message) -> Result<(), stun::Error> {
35        let mut v = vec![0; REQUESTED_TRANSPORT_SIZE];
36        v[0] = self.protocol.0;
37        // b[1:4] is RFFU = 0.
38        // The RFFU field MUST be set to zero on transmission and MUST be
39        // ignored on reception. It is reserved for future uses.
40        m.add(ATTR_REQUESTED_TRANSPORT, &v);
41        Ok(())
42    }
43}
44
45impl Getter for RequestedTransport {
46    /// Decodes `REQUESTED-TRANSPORT` from message.
47    fn get_from(&mut self, m: &Message) -> Result<(), stun::Error> {
48        let v = m.get(ATTR_REQUESTED_TRANSPORT)?;
49
50        check_size(ATTR_REQUESTED_TRANSPORT, v.len(), REQUESTED_TRANSPORT_SIZE)?;
51        self.protocol = Protocol(v[0]);
52        Ok(())
53    }
54}