support renewal without explicit address request

2 files changed, 92 insertions, 26 deletions

diff --git a/src/lease.rs b/src/lease.rs
index 2c5c152..969b3f0 100644
--- a/src/lease.rs
+++ b/src/lease.rs
@@ -29,6 +29,11 @@ impl Lease {
     pub fn expired(&self) -> bool {
         SystemTime::now().duration_since(self.expires).is_ok()
     }
+
+    pub fn renew(&mut self, lease_time: Duration) {
+        self.expires = SystemTime::now() + lease_time;
+        self.lease_time = lease_time;
+    }
 }
 
 pub trait LeaseManager {
@@ -37,6 +42,7 @@ pub trait LeaseManager {
     fn lease_time(&self) -> Duration;
     fn leases(&self) -> Box<dyn Iterator<Item = Lease>>;
     fn request(&mut self, address: Ipv4Addr, client_id: &[u8]) -> Result<bool>;
+    fn renew(&mut self, client_id: &[u8]) -> Result<Option<Ipv4Addr>>;
     fn release(&mut self, client_id: &[u8]) -> Result<Box<dyn Iterator<Item = Ipv4Addr>>>;
 
     fn all_addresses(&self) -> Vec<Ipv4Addr> {
@@ -184,6 +190,21 @@ impl LeaseManager for LeaseDummyManager {
         }
     }
 
+    fn renew(&mut self, client_id: &[u8]) -> Result<Option<Ipv4Addr>> {
+        let lease_time = self.lease_time();
+        let mut address = None;
+
+        self.leases
+            .iter_mut()
+            .filter(|lease| lease.client_id == client_id)
+            .for_each(|lease| {
+                address = Some(lease.address);
+                lease.renew(lease_time);
+            });
+
+        Ok(address)
+    }
+
     fn release(&mut self, client_id: &[u8]) -> Result<Box<dyn Iterator<Item = Ipv4Addr>>> {
         let mut released = Vec::new();
 
@@ -278,10 +299,10 @@ impl LeaseManager for LeaseFileManager {
     }
 
     fn request(&mut self, address: Ipv4Addr, client_id: &[u8]) -> Result<bool> {
-        let range = self.range();
-
         self.garbage_collect()?;
 
+        let range = self.range();
+
         if self.is_unavailable(address, client_id)
             || !Ipv4AddrRange::new(range.0, range.1).any(|addr| addr == address)
         {
@@ -305,6 +326,24 @@ impl LeaseManager for LeaseFileManager {
         }
     }
 
+    fn renew(&mut self, client_id: &[u8]) -> Result<Option<Ipv4Addr>> {
+        self.garbage_collect()?;
+
+        let lease_time = self.lease_time();
+        let mut address = None;
+
+        self.leases
+            .iter_mut()
+            .filter(|lease| lease.client_id == client_id)
+            .for_each(|lease| {
+                address = Some(lease.address);
+                lease.renew(lease_time);
+            });
+
+        self.save()?;
+        Ok(address)
+    }
+
     fn release(&mut self, client_id: &[u8]) -> Result<Box<dyn Iterator<Item = Ipv4Addr>>> {
         self.garbage_collect()?;
 
diff --git a/src/main.rs b/src/main.rs
index 9b16ce6..9f5e669 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -182,15 +182,23 @@ fn handle_request<T: LeaseManager>(
                         _ => unreachable!(),
                     };
 
-                    let requested_addr = match opts
-                        .get(OptionCode::RequestedIpAddress)
-                        .ok_or(Error::NoAddrRequested)?
-                    {
-                        DhcpOption::RequestedIpAddress(addr) => addr,
-                        _ => unreachable!(),
-                    };
-
-                    if !lease_mgr.request(*requested_addr, client_id)? {
+                    let mut renew = false;
+                    let requested_addr =
+                        match opts.get(OptionCode::RequestedIpAddress).map(|v| match v {
+                            DhcpOption::RequestedIpAddress(addr) => addr,
+                            _ => unreachable!(),
+                        }) {
+                            Some(addr) => *addr,
+                            None => match lease_mgr.renew(client_id)? {
+                                Some(addr) => {
+                                    renew = true;
+                                    addr
+                                }
+                                None => return Err(Error::NoAddrRequested),
+                            },
+                        };
+
+                    if !lease_mgr.request(requested_addr, client_id)? {
                         let own_addr = local_ip(link)?;
 
                         let mut resp = Message::default();
@@ -198,7 +206,7 @@ fn handle_request<T: LeaseManager>(
                             .set_flags(Flags::default().set_broadcast())
                             .set_opcode(Opcode::BootReply)
                             .set_xid(xid)
-                            .set_yiaddr(*requested_addr)
+                            .set_yiaddr(requested_addr)
                             .set_siaddr(own_addr)
                             .set_chaddr(msg.chaddr())
                             .opts_mut();
@@ -213,12 +221,21 @@ fn handle_request<T: LeaseManager>(
                         if n != resp_buf.len() {
                             Err(Error::PartialResponse)
                         } else {
-                            println!(
-                                "not ackknowledging {} for client ID {} on {}",
-                                requested_addr,
-                                format_client_id(client_id)?,
-                                link
-                            );
+                            if renew {
+                                println!(
+                                    "not renewing {} for client ID {} on {}",
+                                    requested_addr,
+                                    format_client_id(client_id)?,
+                                    link
+                                );
+                            } else {
+                                println!(
+                                    "not ackknowledging {} for client ID {} on {}",
+                                    requested_addr,
+                                    format_client_id(client_id)?,
+                                    link
+                                );
+                            }
 
                             Ok(())
                         }
@@ -231,7 +248,7 @@ fn handle_request<T: LeaseManager>(
                             .set_flags(Flags::default().set_broadcast())
                             .set_opcode(Opcode::BootReply)
                             .set_xid(xid)
-                            .set_yiaddr(*requested_addr)
+                            .set_yiaddr(requested_addr)
                             .set_siaddr(own_addr)
                             .set_chaddr(msg.chaddr())
                             .opts_mut();
@@ -250,13 +267,23 @@ fn handle_request<T: LeaseManager>(
                         if n != resp_buf.len() {
                             Err(Error::PartialResponse)
                         } else {
-                            println!(
-                                "ackknowledging {} for client ID {} for {:?} on {}",
-                                requested_addr,
-                                format_client_id(client_id)?,
-                                lease_time,
-                                link
-                            );
+                            if renew {
+                                println!(
+                                    "renewing {} for client ID {} for {:?} on {}",
+                                    requested_addr,
+                                    format_client_id(client_id)?,
+                                    lease_time,
+                                    link
+                                );
+                            } else {
+                                println!(
+                                    "ackknowledging {} for client ID {} for {:?} on {}",
+                                    requested_addr,
+                                    format_client_id(client_id)?,
+                                    lease_time,
+                                    link
+                                );
+                            }
 
                             Ok(())
                         }