Improve error handling

src/db/models.rs

@@ -81,15 +81,15 @@ impl Record {
     }
 }
 
-pub async fn insert_into_database(rr: RR) -> Result<(), DatabaseError> {
+pub async fn insert_into_database(rr: &RR) -> Result<(), DatabaseError> {
     let db_connection = &mut establish_connection();
     let record = Record {
         name: rr.name.join("."),
-        _type: rr._type.into(),
+        _type: rr._type.clone().into(),
-        class: rr.class.into(),
+        class: rr.class.clone().into(),
         ttl: rr.ttl,
         rdlength: rr.rdlength as i32,
-        rdata: rr.rdata,
+        rdata: rr.rdata.clone(),
     };
 
     Record::create(db_connection, record).map_err(|e| DatabaseError {
@@ -128,11 +128,17 @@ pub async fn get_from_database(question: &Question) -> Result<Vec<RR>, DatabaseE
 
 //TODO: cleanup models
 pub async fn delete_from_database(
-    name: Vec<String>,
+    name: &Vec<String>,
     _type: Option<Type>,
     class: Class,
     rdata: Option<Vec<u8>>,
 ) {
     let db_connection = &mut establish_connection();
-    let _ = Record::delete(db_connection, name.join("."), _type.map(|f| f.into()), class.into(), rdata);
+    let _ = Record::delete(
+        db_connection,
+        name.join("."),
+        _type.map(|f| f.into()),
+        class.into(),
+        rdata,
+    );
 }

src/errors.rs

@@ -1,8 +1,10 @@
 use core::fmt;
 
-#[derive(Debug)]
+use crate::structs::RCODE;
+
 pub struct DNSError {
     pub message: String,
+    pub rcode: RCODE
 }
 
 impl fmt::Display for DNSError {
@@ -25,7 +27,7 @@ impl fmt::Display for ParseError {
 
 #[derive(Debug)]
 pub struct DatabaseError {
-    pub message: String,
+    pub message: String
 }
 
 impl fmt::Display for DatabaseError {
@@ -67,3 +69,15 @@ where
         }
     }
 }
+
+impl<E> From<E> for DNSError
+where
+    E: Into<ParseError>,
+{
+    fn from(value: E) -> Self {
+        DNSError {
+            message: value.into().to_string(),
+            rcode: RCODE::FORMERR
+        }
+    }
+}

src/resolver.rs

@@ -6,7 +6,7 @@ use tokio::net::UdpSocket;
 
 use crate::authenticate::authenticate;
 use crate::db::models::{delete_from_database, get_from_database, insert_into_database};
-use crate::errors::ParseError;
+use crate::errors::{DNSError, ParseError};
 use crate::parser::FromBytes;
 use crate::reader::Reader;
 use crate::sig::Sig;
@@ -15,7 +15,7 @@ use crate::utils::vec_equal;
 
 const MAX_DATAGRAM_SIZE: usize = 4096;
 
-fn set_response_flags(flags: u16, rcode: RCODE) -> u16 {
+fn set_response_flags(flags: &u16, rcode: RCODE) -> u16 {
     (flags | 0b1_0000_1_0_0_0_000_0000 | rcode as u16) & 0b1_1111_1_0_1_0_111_1111
 }
 
@@ -23,46 +23,50 @@ fn get_opcode(flags: &u16) -> Result<Opcode, String> {
     Opcode::try_from((flags & 0b0111100000000000) >> 11)
 }
 
-async fn handle_query(message: Message) -> Message {
+async fn handle_query(message: &Message) -> Result<Message, DNSError> {
     let mut response = message.clone();
     response.header.arcount = 0; //TODO: fix this, handle unknown class values
 
-    for question in message.question {
+    for question in &message.question {
         let answers = get_from_database(&question).await;
 
         match answers {
             Ok(rrs) => {
-                response.header.flags = set_response_flags(response.header.flags, RCODE::NOERROR);
                 response.header.ancount = rrs.len() as u16;
-                response.answer = rrs
+                response.answer.extend(rrs)
             }
             Err(e) => {
-                response.header.flags = set_response_flags(response.header.flags, RCODE::NXDOMAIN);
+                return Err(DNSError {
-                eprintln!("{}", e);
+                    rcode: RCODE::NXDOMAIN,
+                    message: e.to_string(),
+                })
             }
         }
     }
 
-    response
+    Ok(response)
 }
 
-async fn handle_update(message: Message, bytes: &[u8]) -> Message {
+async fn handle_update(message: &Message, bytes: &[u8]) -> Result<Message, DNSError> {
-    let mut response = message.clone();
+    let response = message.clone();
-
     // Zone section (question) processing
     if (message.header.qdcount != 1)
         || !matches!(message.question[0].qtype, Type::Type(RRType::SOA))
     {
-        response.header.flags = set_response_flags(response.header.flags, RCODE::FORMERR);
+        return Err(DNSError {
-        return response;
+            message: "Qdcount not one".to_string(),
+            rcode: RCODE::FORMERR,
+        });
     }
 
     // Check Zone authority
     let zone = &message.question[0];
     let zlen = zone.qname.len();
     if !(zlen >= 2 && zone.qname[zlen - 1] == "gent" && zone.qname[zlen - 2] == "zeus") {
-        response.header.flags = set_response_flags(response.header.flags, RCODE::NOTAUTH);
+        return Err(DNSError {
-        return response;
+            message: "Invalid zone".to_string(),
+            rcode: RCODE::NOTAUTH,
+        });
     }
 
     // Check Prerequisite    TODO: implement this
@@ -70,15 +74,19 @@ async fn handle_update(message: Message, bytes: &[u8]) -> Message {
     //TODO: this code is ugly
     let last = message.additional.last();
     if last.is_some() && last.unwrap()._type == Type::Type(RRType::KEY) {
-        let sig = Sig::new(last.unwrap(), bytes);
+        let sig = Sig::new(last.unwrap(), bytes)?;
 
         if !authenticate(&sig, &zone.qname).await.is_ok_and(|x| x) {
-            response.header.flags = set_response_flags(response.header.flags, RCODE::NOTAUTH);
+            return Err(DNSError {
-            return response;
+                message: "Unable to verify authentication".to_string(),
+                rcode: RCODE::NOTAUTH,
+            });
         }
     } else {
-        response.header.flags = set_response_flags(response.header.flags, RCODE::NOTAUTH);
+        return Err(DNSError {
-        return response;
+            message: "No KEY record at the end of request found".to_string(),
+            rcode: RCODE::NOTAUTH,
+        });
     }
 
     // Update Section Prescan
@@ -87,8 +95,10 @@ async fn handle_update(message: Message, bytes: &[u8]) -> Message {
 
         // Check if rr has same zone
         if rlen < zlen || !(vec_equal(&zone.qname, &rr.name[rlen - zlen..])) {
-            response.header.flags = set_response_flags(response.header.flags, RCODE::NOTZONE);
+            return Err(DNSError {
-            return response;
+                message: "RR has different zone from Question".to_string(),
+                rcode: RCODE::NOTZONE,
+            });
         }
 
         if (rr.class == Class::Class(RRClass::ANY) && (rr.ttl != 0 || rr.rdlength != 0))
@@ -100,25 +110,33 @@ async fn handle_update(message: Message, bytes: &[u8]) -> Message {
             ]
             .contains(&rr.class)
         {
-            response.header.flags = set_response_flags(response.header.flags, RCODE::FORMERR);
+            return Err(DNSError {
-            return response;
+                message: "RR has invalid rr,ttl or class".to_string(),
+                rcode: RCODE::FORMERR,
+            });
         }
     }
 
-    for rr in message.authority {
+    for rr in &message.authority {
         if rr.class == zone.qclass {
-            let _ = insert_into_database(rr).await;
+            let _ = insert_into_database(&rr).await;
         } else if rr.class == Class::Class(RRClass::ANY) {
             if rr._type == Type::Type(RRType::ANY) {
                 if rr.name == zone.qname {
-                    response.header.flags =
+                    return Err(DNSError {
-                        set_response_flags(response.header.flags, RCODE::NOTIMP);
+                        message: "Not yet implemented".to_string(),
-                    return response;
+                        rcode: RCODE::NOTIMP,
+                    });
                 } else {
-                    delete_from_database(rr.name, None, Class::Class(RRClass::IN), None).await;
+                    delete_from_database(&rr.name, None, Class::Class(RRClass::IN), None).await;
                 }
             } else {
-                delete_from_database(rr.name, Some(rr._type), Class::Class(RRClass::IN), None)
+                delete_from_database(
+                    &rr.name,
+                    Some(rr._type.clone()),
+                    Class::Class(RRClass::IN),
+                    None,
+                )
                 .await;
             }
         } else if rr.class == Class::Class(RRClass::NONE) {
@@ -126,17 +144,16 @@ async fn handle_update(message: Message, bytes: &[u8]) -> Message {
                 continue;
             }
             delete_from_database(
-                rr.name,
+                &rr.name,
-                Some(rr._type),
+                Some(rr._type.clone()),
                 Class::Class(RRClass::IN),
-                Some(rr.rdata),
+                Some(rr.rdata.clone()),
             )
             .await;
         }
     }
 
-    response.header.flags = set_response_flags(response.header.flags, RCODE::NOERROR);
+    Ok(response)
-    response
 }
 
 fn handle_parse_error(bytes: &[u8], err: ParseError) -> Message {
@@ -155,7 +172,7 @@ fn handle_parse_error(bytes: &[u8], err: ParseError) -> Message {
     header.ancount = 0;
     header.nscount = 0;
     header.arcount = 0;
-    header.flags = set_response_flags(header.flags, RCODE::FORMERR);
+    header.flags = set_response_flags(&header.flags, RCODE::FORMERR);
 
     Message {
         header,
@@ -169,11 +186,26 @@ fn handle_parse_error(bytes: &[u8], err: ParseError) -> Message {
 async fn get_response(bytes: &[u8]) -> Message {
     let mut reader = Reader::new(bytes);
     match Message::from_bytes(&mut reader) {
-        Ok(message) => match get_opcode(&message.header.flags) {
+        Ok(mut message) => match get_opcode(&message.header.flags) {
-            Ok(opcode) => match opcode {
+            Ok(opcode) => {
-                Opcode::QUERY => handle_query(message).await,
+                let result = match opcode {
-                Opcode::UPDATE => handle_update(message, bytes).await,
+                    Opcode::QUERY => handle_query(&message).await,
-            },
+                    Opcode::UPDATE => handle_update(&message, bytes).await,
+                };
+
+                match result {
+                    Ok(mut response) => {
+                        response.header.flags =
+                            set_response_flags(&response.header.flags, RCODE::NOERROR);
+                        response
+                    }
+                    Err(e) => {
+                        eprintln!("{}", e.to_string());
+                        message.header.flags = set_response_flags(&message.header.flags, e.rcode);
+                        message
+                    }
+                }
+            }
             Err(_) => todo!(),
         },
         Err(err) => handle_parse_error(bytes, err),

src/sig.rs

@@ -1,6 +1,7 @@
 use base64::prelude::*;
 
 use crate::{
+    errors::ParseError,
     parser::FromBytes,
     reader::Reader,
     structs::{KeyRData, RR},
@@ -16,20 +17,20 @@ pub enum PublicKey {
 }
 
 impl Sig {
-    pub fn new(rr: &RR, datagram: &[u8]) -> Sig {
+    pub fn new(rr: &RR, datagram: &[u8]) -> Result<Sig, ParseError> {
         let mut request = datagram[0..datagram.len() - 11 - rr.rdlength as usize].to_vec();
         request[11] -= 1; // Decrease arcount
 
         let mut reader = Reader::new(&rr.rdata);
-        let key_rdata = KeyRData::from_bytes(&mut reader).unwrap();
+        let key_rdata = KeyRData::from_bytes(&mut reader)?;
 
         let mut raw_data = rr.rdata[0..rr.rdata.len() - key_rdata.signature.len()].to_vec();
         raw_data.extend(request);
 
-        Sig {
+        Ok(Sig {
             raw_data,
             key_rdata,
-        }
+        })
     }
 
     fn verify_ed25519(&self, key: String) -> bool {