added fn for procesing queries

Author: joalopez1206

src/nameserver.rs

@@ -6,7 +6,7 @@ use tokio::net::UdpSocket;
 
 use crate::message::resource_record::ResourceRecord;
 use crate::message::DnsMessage;
-
+use crate::message::rcode::Rcode;
 
 /// Structure to represent a Name Server
 #[derive (Debug)]
@@ -35,26 +35,52 @@ impl NameServer {
             let socket_clone = self.shared_sock.clone();
             tokio::spawn(async move {
                 // Handle the request concurrently!!! Important
-                NameServer::handle_request(socket_clone, data, src).await;
+                self.handle_request(socket_clone, data, src).await;
             });
         }
     }
 
-    async fn handle_request(socket: Arc<Mutex<UdpSocket>>,
+    async fn handle_request(&self, socket: Arc<Mutex<UdpSocket>>,
         data: Vec<u8>,
         addr: std::net::SocketAddr) {
-            let message = DnsMessage::from_bytes(&data).unwrap();
-            // respondemos lo mismo por el momento
-            let response = message.to_bytes();
+            let mut message = DnsMessage::from_bytes(&data).expect("Error al parsear el mensaje");
+
+            let rrs_to_add = NameServer::search_query(&self.zone, &message);
 
+            if rrs_to_add.len() > 0 {
+                NameServer::add_rrs(&mut message, &rrs_to_add)
+            }
+            let response = message.to_bytes();
             // lock the socket and send the response
             let mut sock = socket.lock().await;
             if let Err(e) = sock.send_to(&response, addr).await {
                 eprintln!("Failed to send response to {}: {}", addr, e);
             } else {
                 println!("Sent response to {:?}", addr);
             }
-        }
+    }
+
+    fn add_rrs(msg :&mut DnsMessage, rrs: &Vec<ResourceRecord>) {
+        msg.set_answer(rrs.clone());
+        let mut header = msg.get_header();
+        header.set_aa(true);
+        header.set_rcode(Rcode::NOERROR);
+        header.set_qr(true);
+        header.set_ancount(rrs.len() as u16);
+        msg.set_header(header);
+    }
+
+    fn search_query(zone: &Vec<ResourceRecord>, msg: &DnsMessage) -> Vec<ResourceRecord> {
+        let qclass = msg.get_question().get_rclass();
+        let qtype = msg.get_question().get_rrtype();
+        let qname = msg.get_question().get_qname();
+        zone.iter()
+            .filter(|rr|
+                qclass == rr.get_rclass()
+                    && qtype == rr.get_rtype()
+                    && qname == rr.get_name())
+            .collect()
+    }
 }