first commit

src/node_setup.rs

@@ -0,0 +1,84 @@
+use tokio_tun::{Tun, TunBuilder};
+use std::{
+    sync::Arc,
+    net::Ipv4Addr,
+    error::Error,
+};
+use rtnetlink::Handle;
+use futures::stream::TryStreamExt;
+
+pub const TUN_NAME: &str = "tun0";
+pub const TUN_ROUTE_DEST: Ipv4Addr = Ipv4Addr::new(10, 0, 0, 0);
+pub const TUN_ROUTE_PREFIX: u8 = 24;
+
+// Create a TUN interface
+pub fn create_tun_interface(int_addr: Ipv4Addr) -> Result<Arc<Tun>, Box<dyn Error>> {
+    let tun = TunBuilder::new()
+        .name(TUN_NAME)
+        .tap(false)
+        .mtu(1420)
+        .packet_info(false)
+        .address(int_addr)
+        .broadcast(Ipv4Addr::new(255, 255, 255, 0))
+        .up()
+        .try_build()?;
+
+    Ok(Arc::new(tun))
+}
+
+// Add a route to the TUN interface
+pub async fn add_route(handle: Handle) -> Result<(), Box<dyn Error>> {
+    let mut link_request = handle
+        .link()
+        .get()
+        .match_name(String::from(TUN_NAME))
+        .execute();
+
+    let link_idx = if let Some(link) = link_request.try_next().await? {
+        link.header.index
+    } else {
+        eprintln!("link not found");
+        panic!("link not found");
+    };
+
+    let route = handle.route();
+    route
+        .add()
+        .v4()
+        .destination_prefix(TUN_ROUTE_DEST, TUN_ROUTE_PREFIX)
+        .output_interface(link_idx)
+        .execute()
+        .await?;
+
+    Ok(())
+}
+
+pub async fn setup_node(tun_addr: Ipv4Addr) -> Result<Arc<Tun>, Box<dyn Error>> {
+    match create_tun_interface(tun_addr) {
+        Ok(tun) => {
+            println!("Interface '{}' ({}) created", TUN_NAME, tun_addr);
+            match rtnetlink::new_connection() {
+                Ok((conn, handle, _)) => {
+                    tokio::spawn(conn);
+                    match add_route(handle.clone()).await {
+                        Ok(_) => {
+                            println!("Static route created");
+                        },
+                        Err(e) => {
+                            panic!("Error adding route: {}", e);
+                        }
+                    }
+                },
+                Err(e) => {
+                    panic!("Error creating new handle: {}", e);
+                }
+            }
+
+            
+            Ok(tun)
+        }, 
+        Err(e) => {
+            panic!("Error creating TUN: {}", e);
+        }
+    }
+}