netlink_packet_route/rtnl/route/
message.rs

1// SPDX-License-Identifier: MIT
2
3use crate::{
4    nlas::route::Nla,
5    traits::{Emitable, Parseable},
6    DecodeError,
7    RouteHeader,
8    RouteMessageBuffer,
9};
10use anyhow::Context;
11use std::net::IpAddr;
12
13#[derive(Debug, PartialEq, Eq, Clone, Default)]
14pub struct RouteMessage {
15    pub header: RouteHeader,
16    pub nlas: Vec<Nla>,
17}
18
19impl Emitable for RouteMessage {
20    fn buffer_len(&self) -> usize {
21        self.header.buffer_len() + self.nlas.as_slice().buffer_len()
22    }
23
24    fn emit(&self, buffer: &mut [u8]) {
25        self.header.emit(buffer);
26        self.nlas
27            .as_slice()
28            .emit(&mut buffer[self.header.buffer_len()..]);
29    }
30}
31
32impl<'a, T: AsRef<[u8]> + 'a> Parseable<RouteMessageBuffer<&'a T>> for RouteMessage {
33    fn parse(buf: &RouteMessageBuffer<&'a T>) -> Result<Self, DecodeError> {
34        Ok(RouteMessage {
35            header: RouteHeader::parse(buf).context("failed to parse route message header")?,
36            nlas: Vec::<Nla>::parse(buf).context("failed to parse route message NLAs")?,
37        })
38    }
39}
40
41impl<'a, T: AsRef<[u8]> + 'a> Parseable<RouteMessageBuffer<&'a T>> for Vec<Nla> {
42    fn parse(buf: &RouteMessageBuffer<&'a T>) -> Result<Self, DecodeError> {
43        let mut nlas = vec![];
44        for nla_buf in buf.nlas() {
45            nlas.push(Nla::parse(&nla_buf?)?);
46        }
47        Ok(nlas)
48    }
49}
50
51fn octets_to_addr(octets: &[u8]) -> Result<IpAddr, DecodeError> {
52    if octets.len() == 4 {
53        let mut ary: [u8; 4] = Default::default();
54        ary.copy_from_slice(octets);
55        Ok(IpAddr::from(ary))
56    } else if octets.len() == 16 {
57        let mut ary: [u8; 16] = Default::default();
58        ary.copy_from_slice(octets);
59        Ok(IpAddr::from(ary))
60    } else {
61        Err(DecodeError::from("Cannot decode IP address"))
62    }
63}
64
65impl RouteMessage {
66    /// Returns the input interface index, if present.
67    pub fn input_interface(&self) -> Option<u32> {
68        self.nlas.iter().find_map(|nla| {
69            if let Nla::Iif(v) = nla {
70                Some(*v)
71            } else {
72                None
73            }
74        })
75    }
76
77    /// Returns the output interface index, if present.
78    pub fn output_interface(&self) -> Option<u32> {
79        self.nlas.iter().find_map(|nla| {
80            if let Nla::Oif(v) = nla {
81                Some(*v)
82            } else {
83                None
84            }
85        })
86    }
87
88    /// Returns the source address prefix, if present.
89    pub fn source_prefix(&self) -> Option<(IpAddr, u8)> {
90        self.nlas.iter().find_map(|nla| {
91            if let Nla::Source(v) = nla {
92                octets_to_addr(v)
93                    .ok()
94                    .map(|addr| (addr, self.header.source_prefix_length))
95            } else {
96                None
97            }
98        })
99    }
100
101    /// Returns the destination subnet prefix, if present.
102    pub fn destination_prefix(&self) -> Option<(IpAddr, u8)> {
103        self.nlas.iter().find_map(|nla| {
104            if let Nla::Destination(v) = nla {
105                octets_to_addr(v)
106                    .ok()
107                    .map(|addr| (addr, self.header.destination_prefix_length))
108            } else {
109                None
110            }
111        })
112    }
113
114    /// Returns the gateway address, if present.
115    pub fn gateway(&self) -> Option<IpAddr> {
116        self.nlas.iter().find_map(|nla| {
117            if let Nla::Gateway(v) = nla {
118                octets_to_addr(v).ok()
119            } else {
120                None
121            }
122        })
123    }
124}
netlink_packet_route/rtnl/route/message.rs

netlink_packet_route/rtnl/route/
message.rs
