use netlink_packet_core::{
NetlinkHeader, NetlinkMessage, NetlinkPayload, NLM_F_DUMP, NLM_F_REQUEST,
};
use netlink_packet_route::{
neighbour::{NeighbourAddress, NeighbourAttribute, NeighbourMessage},
AddressFamily, RouteNetlinkMessage,
};
use netlink_sys::{protocols::NETLINK_ROUTE, Socket, SocketAddr};
fn main() {
let mut socket = Socket::new(NETLINK_ROUTE).unwrap();
let _port_number = socket.bind_auto().unwrap().port_number();
socket.connect(&SocketAddr::new(0, 0)).unwrap();
let mut nl_hdr = NetlinkHeader::default();
nl_hdr.flags = NLM_F_DUMP | NLM_F_REQUEST;
let mut req = NetlinkMessage::new(
nl_hdr,
NetlinkPayload::from(RouteNetlinkMessage::GetNeighbour(
NeighbourMessage::default(),
)),
);
req.finalize();
let mut buf = vec![0; req.header.length as usize];
req.serialize(&mut buf[..]);
println!(">>> {req:?}");
socket.send(&buf[..], 0).unwrap();
let mut receive_buffer = vec![0; 4096];
let mut offset = 0;
'outer: loop {
let size = socket.recv(&mut &mut receive_buffer[..], 0).unwrap();
loop {
let bytes = &receive_buffer[offset..];
let msg: NetlinkMessage<RouteNetlinkMessage> =
NetlinkMessage::deserialize(bytes).unwrap();
match msg.payload {
NetlinkPayload::Done(_) => break 'outer,
NetlinkPayload::InnerMessage(
RouteNetlinkMessage::NewNeighbour(entry),
) => {
let address_family = entry.header.family;
if address_family == AddressFamily::Inet
|| address_family == AddressFamily::Inet6
{
print_entry(entry);
}
}
NetlinkPayload::Error(err) => {
eprintln!("Received a netlink error message: {err:?}");
return;
}
_ => {}
}
offset += msg.header.length as usize;
if offset == size || msg.header.length == 0 {
offset = 0;
break;
}
}
}
}
fn format_ip(addr: &NeighbourAddress) -> String {
if let NeighbourAddress::Inet(ip) = addr {
ip.to_string()
} else if let NeighbourAddress::Inet6(ip) = addr {
ip.to_string()
} else {
panic!("Invalid IP Address");
}
}
fn format_mac(buf: &[u8]) -> String {
if buf.len() == 6 {
format!(
"{:<02x}:{:<02x}:{:<02x}:{:<02x}:{:<02x}:{:<02x}",
buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]
)
} else {
"00:00:00:00:00:00".into()
}
}
fn print_entry(entry: NeighbourMessage) {
let state = entry.header.state;
if let (Some(dest), Some(lladdr)) = (
entry.attributes.iter().find_map(|nla| {
if let NeighbourAttribute::Destination(addr) = nla {
Some(format_ip(addr))
} else {
None
}
}),
entry.attributes.iter().find_map(|nla| {
if let NeighbourAttribute::LinkLocalAddress(addr) = nla {
Some(format_mac(addr))
} else {
None
}
}),
) {
println!("{dest:<30} {lladdr:<20} ({state})");
}
}