feat: add get address with label filter

Signed-off-by: Shuoran Liu <[email protected]>

examples/get_address.rs

@@ -2,16 +2,30 @@
 
 use futures::stream::TryStreamExt;
 use rtnetlink::{new_connection, Error, Handle};
+use std::env;
 
 #[tokio::main]
 async fn main() -> Result<(), ()> {
+    let args: Vec<String> = env::args().collect();
+    if args.len() != 2 {
+        return Ok(());
+    }
+
+    let link_name = &args[1];
+
     let (connection, handle, _) = new_connection().unwrap();
     tokio::spawn(connection);
 
     let link = "lo".to_string();
     println!("dumping address for link \"{link}\"");
 
-    if let Err(e) = dump_addresses(handle, link).await {
+    if let Err(e) = dump_addresses(handle.clone(), link).await {
+        eprintln!("{e}");
+    }
+
+    let label = format!("{link_name}:vip");
+    println!("\ndumping address with label \"{label}\"");
+    if let Err(e) = dump_addresses_with_label(handle, &label).await {
         eprintln!("{e}");
     }
 
@@ -35,3 +49,16 @@ async fn dump_addresses(handle: Handle, link: String) -> Result<(), Error> {
         Ok(())
     }
 }
+
+async fn dump_addresses_with_label(
+    handle: Handle,
+    label: &str,
+) -> Result<(), Error> {
+    let mut addrs = handle.address().get().set_label_filter(label).execute();
+
+    while let Some(msg) = addrs.try_next().await? {
+        println!("{msg:?}");
+    }
+
+    Ok(())
+}

src/addr/get.rs

@@ -71,6 +71,11 @@ impl AddressGetRequest {
         self.filter_builder.address = Some(address);
         self
     }
+
+    pub fn set_label_filter(mut self, label: &str) -> Self {
+        self.filter_builder.label = Some(label.to_string());
+        self
+    }
 }
 
 // The reason for having filters, is that we cannot retrieve addresses
@@ -84,6 +89,7 @@ struct AddressFilterBuilder {
     index: Option<u32>,
     address: Option<IpAddr>,
     prefix_len: Option<u8>,
+    label: Option<String>,
 }
 
 impl AddressFilterBuilder {
@@ -127,6 +133,18 @@ impl AddressFilterBuilder {
                 }
                 return false;
             }
+
+            if let Some(ref label) = self.label {
+                for nla in msg.nlas.iter() {
+                    if let Label(l) = nla {
+                        if label == l {
+                            return true;
+                        }
+                    }
+                }
+                return false;
+            }
+
             true
         }
     }