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use crate::{
nlas::route::Nla,
traits::{Emitable, Parseable},
DecodeError, RouteHeader, RouteMessageBuffer,
};
use anyhow::Context;
use std::net::IpAddr;
#[derive(Debug, PartialEq, Eq, Clone, Default)]
#[non_exhaustive]
pub struct RouteMessage {
pub header: RouteHeader,
pub nlas: Vec<Nla>,
}
impl Emitable for RouteMessage {
fn buffer_len(&self) -> usize {
self.header.buffer_len() + self.nlas.as_slice().buffer_len()
}
fn emit(&self, buffer: &mut [u8]) {
self.header.emit(buffer);
self.nlas
.as_slice()
.emit(&mut buffer[self.header.buffer_len()..]);
}
}
impl<'a, T: AsRef<[u8]> + 'a> Parseable<RouteMessageBuffer<&'a T>>
for RouteMessage
{
fn parse(buf: &RouteMessageBuffer<&'a T>) -> Result<Self, DecodeError> {
Ok(RouteMessage {
header: RouteHeader::parse(buf)
.context("failed to parse route message header")?,
nlas: Vec::<Nla>::parse(buf)
.context("failed to parse route message NLAs")?,
})
}
}
impl<'a, T: AsRef<[u8]> + 'a> Parseable<RouteMessageBuffer<&'a T>>
for Vec<Nla>
{
fn parse(buf: &RouteMessageBuffer<&'a T>) -> Result<Self, DecodeError> {
let mut nlas = vec![];
for nla_buf in buf.nlas() {
nlas.push(Nla::parse(&nla_buf?)?);
}
Ok(nlas)
}
}
fn octets_to_addr(octets: &[u8]) -> Result<IpAddr, DecodeError> {
if octets.len() == 4 {
let mut ary: [u8; 4] = Default::default();
ary.copy_from_slice(octets);
Ok(IpAddr::from(ary))
} else if octets.len() == 16 {
let mut ary: [u8; 16] = Default::default();
ary.copy_from_slice(octets);
Ok(IpAddr::from(ary))
} else {
Err(DecodeError::from("Cannot decode IP address"))
}
}
impl RouteMessage {
pub fn input_interface(&self) -> Option<u32> {
self.nlas.iter().find_map(|nla| {
if let Nla::Iif(v) = nla {
Some(*v)
} else {
None
}
})
}
pub fn output_interface(&self) -> Option<u32> {
self.nlas.iter().find_map(|nla| {
if let Nla::Oif(v) = nla {
Some(*v)
} else {
None
}
})
}
pub fn source_prefix(&self) -> Option<(IpAddr, u8)> {
self.nlas.iter().find_map(|nla| {
if let Nla::Source(v) = nla {
octets_to_addr(v)
.ok()
.map(|addr| (addr, self.header.source_prefix_length))
} else {
None
}
})
}
pub fn destination_prefix(&self) -> Option<(IpAddr, u8)> {
self.nlas.iter().find_map(|nla| {
if let Nla::Destination(v) = nla {
octets_to_addr(v)
.ok()
.map(|addr| (addr, self.header.destination_prefix_length))
} else {
None
}
})
}
pub fn gateway(&self) -> Option<IpAddr> {
self.nlas.iter().find_map(|nla| {
if let Nla::Gateway(v) = nla {
octets_to_addr(v).ok()
} else {
None
}
})
}
}