add new_route example

examples/new_route.rs

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: MIT
+
+use std::net::{Ipv4Addr};
+use netlink_packet_core::{
+    NetlinkHeader, NetlinkMessage, NetlinkPayload, NLM_F_ACK, NLM_F_CREATE,
+    NLM_F_EXCL, NLM_F_REQUEST,
+};
+use netlink_packet_route::{
+    constants::{AF_INET}, route, RtnlMessage, RouteHeader, RouteMessage, RouteFlags,
+    RT_TABLE_MAIN, RTPROT_BOOT, RT_SCOPE_UNIVERSE, RTN_UNICAST,
+};
+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 route_msg_hdr = RouteHeader::default();
+    route_msg_hdr.address_family = AF_INET as u8;
+    route_msg_hdr.table = RT_TABLE_MAIN;
+    route_msg_hdr.scope = RT_SCOPE_UNIVERSE;
+    route_msg_hdr.protocol = RTPROT_BOOT;
+    route_msg_hdr.kind = RTN_UNICAST;
+    route_msg_hdr.source_prefix_length = 0;
+    route_msg_hdr.destination_prefix_length = 32;
+    route_msg_hdr.flags = RouteFlags::RTNH_F_ONLINK;
+
+    let mut route_msg = RouteMessage::default();
+    route_msg.header = route_msg_hdr;
+    route_msg.nlas = vec![
+        // lo
+        route::Nla::Oif(1),
+        route::Nla::Gateway(
+            "169.254.1.1".parse::<Ipv4Addr>().unwrap().octets().to_vec()),
+        route::Nla::Destination(
+            "1.1.1.1".parse::<Ipv4Addr>().unwrap().octets().to_vec()),
+    ];
+    let mut nl_hdr = NetlinkHeader::default();
+    nl_hdr.flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL | NLM_F_ACK;
+
+    let mut msg = NetlinkMessage::new(
+        nl_hdr,
+        NetlinkPayload::from(RtnlMessage::NewRoute(route_msg)),
+    );
+
+    msg.finalize();
+    let mut buf = vec![0; msg.header.length as usize];
+
+    msg.serialize(&mut buf[..msg.buffer_len()]);
+
+    println!(">>> {msg:?}");
+
+    socket
+        .send(&buf, 0)
+        .expect("failed to send netlink message");
+
+    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..];
+            // Parse the message
+            let rx_packet: NetlinkMessage<RtnlMessage> =
+                NetlinkMessage::deserialize(bytes).unwrap();
+
+            match rx_packet.payload {
+                NetlinkPayload::Error(err) => {
+                    match err.code {
+                        None => {
+                            println!("Done!");
+                            break 'outer;
+                        }
+                        Some(_) => {
+                            eprintln!("Received a netlink error message: {err:?}");
+                            return;
+                        }
+                    }
+                }
+                _ => {}
+            }
+
+            offset += rx_packet.header.length as usize;
+            if offset == size || rx_packet.header.length == 0 {
+                offset = 0;
+                break;
+            }
+        }
+    }
+}