flex_dns/rdata/
mx.rs

1use crate::{Buffer, DnsMessage, DnsMessageError, MutBuffer};
2use crate::name::DnsName;
3use crate::parse::Parse;
4use crate::rdata::{RData, RDataParse};
5use crate::write::WriteBytes;
6
7/// # Mail exchange
8/// This record is used to specify the mail exchange for a domain name.
9#[derive(Copy, Clone, Debug, PartialEq)]
10pub struct Mx<'a> {
11    /// The preference of this mail exchange
12    pub preference: u16,
13    /// The domain name of the mail exchange
14    pub exchange: DnsName<'a>,
15}
16
17impl<'a> RDataParse<'a> for Mx<'a> {
18    #[inline]
19    fn parse(rdata: &RData<'a>, i: &mut usize) -> Result<Self, DnsMessageError> {
20        let preference = u16::parse(rdata.buffer, i)?;
21        let exchange = DnsName::parse(rdata.buffer, i)?;
22
23        Ok(Self {
24            preference,
25            exchange,
26        })
27    }
28}
29
30impl<'a> WriteBytes for Mx<'a> {
31    #[inline]
32    fn write<
33        const PTR_STORAGE: usize,
34        const DNS_SECTION: usize,
35        B: MutBuffer + Buffer,
36    >(&self, message: &mut DnsMessage<PTR_STORAGE, DNS_SECTION, B>) -> Result<usize, DnsMessageError> {
37        let mut bytes = 0;
38
39        bytes += self.preference.write(message)?;
40        bytes += self.exchange.write(message)?;
41
42        Ok(bytes)
43    }
44}
45
46#[cfg(test)]
47mod test {
48    use crate::rdata::testutils::parse_write_test;
49
50    use super::*;
51
52    parse_write_test!(
53        7,
54        [
55            0x00, 0x0e, // preference
56            0x03, b'w', b'w', b'w', 0x00, // exchange
57        ],
58        Mx {
59            preference: 14,
60            exchange: unsafe { DnsName::new_unchecked(b"\x03www\x00") },
61        },
62    );
63}
flex_dns/rdata/mx.rs

flex_dns/rdata/
mx.rs
