simple_dns/dns/rdata/
a.rs

1use crate::{bytes_buffer::BytesBuffer, dns::WireFormat};
2use std::net::Ipv4Addr;
3
4use super::RR;
5
6/// Represents a Resource Address (IPv4)
7#[derive(Debug, PartialEq, Eq, Hash, Clone)]
8pub struct A {
9    /// a 32 bit ip address
10    pub address: u32,
11}
12
13impl RR for A {
14    const TYPE_CODE: u16 = 1;
15}
16
17impl<'a> WireFormat<'a> for A {
18    const MINIMUM_LEN: usize = 4;
19
20    fn parse(data: &mut BytesBuffer<'a>) -> crate::Result<Self>
21    where
22        Self: Sized,
23    {
24        data.get_u32().map(|address| Self { address })
25    }
26
27    fn write_to<T: std::io::Write>(&self, out: &mut T) -> crate::Result<()> {
28        out.write_all(&self.address.to_be_bytes())
29            .map_err(crate::SimpleDnsError::from)
30    }
31}
32
33impl A {
34    /// Transforms the inner data into its owned type
35    pub fn into_owned(self) -> Self {
36        self
37    }
38}
39
40impl From<Ipv4Addr> for A {
41    fn from(addr: Ipv4Addr) -> Self {
42        Self {
43            address: addr.into(),
44        }
45    }
46}
47
48#[cfg(test)]
49mod tests {
50    use crate::{rdata::RData, ResourceRecord};
51
52    use super::*;
53
54    #[test]
55    fn parse_and_write_a() {
56        let a = A {
57            address: 2130706433,
58        };
59
60        let mut bytes = Vec::new();
61        assert!(a.write_to(&mut bytes).is_ok());
62
63        let a = A::parse(&mut BytesBuffer::new(&bytes));
64        assert!(a.is_ok());
65        let a = a.unwrap();
66
67        assert_eq!(2130706433, a.address);
68        assert_eq!(bytes.len(), a.len());
69    }
70
71    #[test]
72    fn parse_sample() -> Result<(), Box<dyn std::error::Error>> {
73        let sample_a = std::fs::read("samples/zonefile/A.sample.A")?;
74        let sample_ip: u32 = "26.3.0.103".parse::<Ipv4Addr>()?.into();
75
76        let sample_a_rdata = match ResourceRecord::parse(&mut BytesBuffer::new(&sample_a))?.rdata {
77            RData::A(a) => a,
78            _ => unreachable!(),
79        };
80
81        assert_eq!(sample_a_rdata.address, sample_ip);
82        Ok(())
83    }
84}