support DHCPRELEASE

2 files changed, 43 insertions, 0 deletions

diff --git a/src/lease.rs b/src/lease.rs
index 779ec31..0369a72 100644
--- a/src/lease.rs
+++ b/src/lease.rs
@@ -28,6 +28,7 @@ pub trait LeaseManager {
     fn leases(&self) -> Box<dyn Iterator<Item = Lease>>;
     fn request(&mut self, address: Ipv4Addr, client_id: &[u8]) -> bool;
     fn lease_time(&self) -> Duration;
+    fn release(&mut self, client_id: &[u8]) -> Box<dyn Iterator<Item = Ipv4Addr>>;
 
     fn all_addresses(&self) -> Vec<Ipv4Addr> {
         let range = self.range();
@@ -169,4 +170,20 @@ impl LeaseManager for LeaseDummyManager {
     fn lease_time(&self) -> Duration {
         Duration::from_secs(300)
     }
+
+    fn release(&mut self, client_id: &[u8]) -> Box<dyn Iterator<Item = Ipv4Addr>> {
+        let mut released = Vec::new();
+
+        self.leases
+            .clone()
+            .into_iter()
+            .enumerate()
+            .filter(|(_, lease)| lease.client_id == client_id)
+            .for_each(|(i, lease)| {
+                self.leases.remove(i);
+                released.push(lease.address);
+            });
+
+        Box::new(released.into_iter())
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index 4d58082..ac2f8ff 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -225,6 +225,32 @@ fn handle_request(
                         }
                     }
                 }
+                MessageType::Release => {
+                    let client_id = match opts
+                        .get(OptionCode::ClientIdentifier)
+                        .ok_or(anyhow!("no client id"))?
+                    {
+                        DhcpOption::ClientIdentifier(id) => id,
+                        _ => bail!("expected ClientIdentifier"),
+                    };
+
+                    let mut lease_mgr = lease_mgr.lock().unwrap();
+                    let released: Vec<String> = lease_mgr
+                        .release(client_id)
+                        .map(|addr| addr.to_string())
+                        .collect();
+
+                    let released_pretty = released.join(", ");
+
+                    let cid = client_id
+                        .iter()
+                        .map(|octet| format!("{:x}", octet))
+                        .reduce(|acc, octet| acc + &octet)
+                        .ok_or(anyhow!("zero-length client id"))?;
+
+                    println!("releasing {} for client ID {}", released_pretty, cid);
+                    Ok(())
+                }
                 _ => Err(anyhow!("invalid message type {:?}", msg_type,)),
             }
         }