Don't panic in Drop (#12)

lib/host.rs

@@ -107,7 +107,7 @@ impl Host {
             .map_err(|err| Error::VmnetFailed { source: err })?;
 
         // Now let the callback finish
-        self.callback_can_continue_tx.send(()).unwrap();
+        let _ = self.callback_can_continue_tx.send(());
 
         self.interface
             .finalize()

lib/proxy/host.rs

@@ -12,7 +12,9 @@ impl Proxy {
 
         // Snoop bootpd(8) replies from the host to
         // figure out the IP assigned to the VM
-        self.snoop(frame);
+        if frame.dst_addr() == self.vm_mac_address {
+            self.snoop(frame);
+        }
 
         self.vm
             .write(frame.as_ref())