Working but not correct answering of A

.gitignore

@@ -1 +1,3 @@
 /target
+.env
+*.sqlite

Cargo.toml

@@ -8,4 +8,3 @@ edition = "2021"
 diesel = { version = "2.1.4", features = ["sqlite"] }
 dotenvy = "0.15"
 tokio = {version = "1.36.0", features = ["full"]}
-

diesel.toml

@@ -0,0 +1,9 @@
+# For documentation on how to configure this file,
+# see https://diesel.rs/guides/configuring-diesel-cli
+
+[print_schema]
+file = "src/schema.rs"
+custom_type_derives = ["diesel::query_builder::QueryId"]
+
+[migrations_directory]
+dir = "migrations"

src/main.rs

@@ -4,6 +4,8 @@ use parser::FromBytes;
 use structs::Message;
 use tokio::net::UdpSocket;
 
+use crate::structs::{Class, Type, RR};
+
 mod errors;
 mod parser;
 mod structs;
@@ -11,8 +13,24 @@ mod worker;
 
 const MAX_DATAGRAM_SIZE: usize = 40_96;
 
-async fn create_query(message: Message) {
+async fn create_query(message: Message) -> Message {
-    println!("{:?}", message);
+    let mut response = message.clone();
+    let ip = String::from("93.184.216.34");
+    let rr = RR {
+        name: vec![String::from("example"),String::from("org")],
+        _type: Type::A,
+        class: Class::IN,
+        ttl: 4096,
+        rdlength: ip.len() as u16,
+        rdata: ip,
+    };
+
+    response.header.flags |= 0b1000010110000000;
+    response.header.ancount = 1;
+    response.header.arcount = 0;
+    response.answer = Some(rr);
+
+    response
 }
 
 #[tokio::main]
@@ -22,13 +40,19 @@ async fn main() -> Result<(), Box<dyn Error>> {
     let socket = UdpSocket::bind(local_addr).await?;
 
     let mut data = vec![0u8; MAX_DATAGRAM_SIZE];
-    loop {
+    let (len,addr) = socket.recv_from(&mut data).await?;
-        let len = socket.recv(&mut data).await?;
     match Message::from_bytes(&data[..len]) {
         Ok(message) => {
-                tokio::spawn(async move { create_query(message).await });
+            tokio::spawn(async move {
+                let response = create_query(message).await;
+                println!("{:?}",response);
+                let vec = Message::to_bytes(&response);
+                let decoded = Message::from_bytes(vec.as_slice());
+                println!("{:?}",decoded);
+                let _ = socket.send_to(vec.as_slice(),addr).await;
+            });
         }
         Err(err) => println!("{}", err),
     };
-    }
+    loop {}
 }

src/parser.rs

@@ -1,8 +1,8 @@
-use std::mem::size_of;
+use std::{mem::size_of, vec};
 
 use crate::{
     errors::ParseError,
-    structs::{Class, Header, Message, Question, Type},
+    structs::{Class, Header, Message, Question, Type, RR},
 };
 
 type Result<T> = std::result::Result<T, ParseError>;
@@ -29,11 +29,13 @@ impl TryFrom<u16> for Class {
     }
 }
 
-// TODO: use Error instead of Option
 pub trait FromBytes {
     fn from_bytes(bytes: &[u8]) -> Result<Self>
     where
         Self: Sized;
+    fn to_bytes(s: &Self) -> Vec<u8>
+    where
+        Self: Sized;
 }
 
 impl FromBytes for Header {
@@ -54,9 +56,21 @@ impl FromBytes for Header {
             })
         }
     }
+
+    fn to_bytes(header: &Self) -> Vec<u8> {
+        let mut result: [u8; size_of::<Header>()] = [0; size_of::<Header>()];
+
+        result[0..2].copy_from_slice(&u16::to_be_bytes(header.id));
+        result[2..4].copy_from_slice(&u16::to_be_bytes(header.flags));
+        result[4..6].copy_from_slice(&u16::to_be_bytes(header.qdcount));
+        result[6..8].copy_from_slice(&u16::to_be_bytes(header.ancount));
+        result[8..10].copy_from_slice(&u16::to_be_bytes(header.nscount));
+        result[10..12].copy_from_slice(&u16::to_be_bytes(header.arcount));
+
+        result.to_vec()
+    }
 }
 
-//HACK: lots of unsafe unwrap
 impl FromBytes for Question {
     fn from_bytes(bytes: &[u8]) -> Result<Self> {
         // 16 for length octet +  zero length octet
@@ -107,6 +121,45 @@ impl FromBytes for Question {
             }
         }
     }
+
+    fn to_bytes(question: &Self) -> Vec<u8> {
+        let mut result: Vec<u8> = vec![];
+        for label in &question.qname {
+            result.push(label.len() as u8);
+            result.extend(label.as_bytes());
+        }
+        result.push(0);
+        result.extend(u16::to_be_bytes(question.qtype.to_owned() as u16));
+        result.extend(u16::to_be_bytes(question.qclass.to_owned() as u16));
+        result
+    }
+}
+
+impl FromBytes for RR {
+    fn from_bytes(bytes: &[u8]) -> Result<Self>
+    where
+        Self: Sized,
+    {
+        todo!()
+    }
+
+    fn to_bytes(rr: &Self) -> Vec<u8> {
+        let mut result = vec![];
+        for label in &rr.name {
+            result.push(label.len() as u8);
+            result.extend(label.as_bytes());
+        }
+        result.push(0);
+        result.extend(u16::to_be_bytes(rr._type.to_owned() as u16));
+        result.extend(u16::to_be_bytes(rr.class.to_owned() as u16));
+        result.extend(i32::to_be_bytes(rr.ttl.to_owned()));
+        result.extend(u16::to_be_bytes(4 as u16));
+        result.push(93);
+        result.push(184);
+        result.push(216);
+        result.push(34);
+        result
+    }
 }
 
 impl FromBytes for Message {
@@ -121,4 +174,20 @@ impl FromBytes for Message {
             additional: None,
         })
     }
+
+    fn to_bytes(message: &Self) -> Vec<u8> {
+        let mut result = vec![];
+        result.extend(Header::to_bytes(&message.header));
+        result.extend(Question::to_bytes(&message.question));
+        if message.answer.is_some() {
+            result.extend(RR::to_bytes(&message.answer.clone().unwrap()));
+        }
+        if message.authority.is_some() {
+            result.extend(RR::to_bytes(&message.authority.clone().unwrap()));
+        }
+        if message.additional.is_some() {
+            result.extend(RR::to_bytes(&message.additional.clone().unwrap()));
+        } 
+        result
+    }
 }

src/structs.rs

@@ -1,24 +1,23 @@
-
 #[repr(u16)]
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Type {
     A = 1,
 }
 
 #[repr(u16)]
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Class {
     IN = 1,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Question {
     pub qname: Vec<String>, // TODO: not padded
     pub qtype: Type,        // NOTE: should be QTYPE, right now not really needed
-    pub qclass: Class,
+    pub qclass: Class,      //NOTE: should be QCLASS, right now not really needed
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Header {
     pub id: u16,
     pub flags: u16, // |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   | ; 1 | 4 | 1 | 1 | 1 | 1 | 3 | 4
@@ -28,7 +27,7 @@ pub struct Header {
     pub arcount: u16,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Message {
     pub header: Header,
     pub question: Question,
@@ -37,14 +36,14 @@ pub struct Message {
     pub additional: Option<RR>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct RR {
-    name: String,
+    pub name: Vec<String>,
-    t: u16,
+    pub _type: Type,
-    class: u16,
+    pub class: Class,
-    ttl: u32,
+    pub ttl: i32,
-    rdlength: u16,
+    pub rdlength: u16,
-    rdata: String,
+    pub rdata: String,
 }
 
 #[derive(Debug)]