feat: added linting

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "rust-analyzer.check.command": "clippy"
+}

src/config.rs

@@ -2,6 +2,7 @@ use anyhow::{Result, ensure};
 use serde::Deserialize;
 
 #[derive(Deserialize)]
+#[allow(clippy::upper_case_acronyms)]
 pub enum EntryType {
     A,
     AAAA,
@@ -61,7 +62,7 @@ pub fn load() -> Result<ConfigData> {
     };
 
     for entry in &mut file_config.entries {
-        let address_parts: Vec<&str> = entry.address.split(".").collect();
+        let address_parts: Vec<&str> = entry.address.split('.').collect();
         ensure!(address_parts.len() == 4, "Invalid IP address");
         entry.address_bytes = [
             address_parts[0].parse()?,

src/dns/answer.rs

@@ -17,7 +17,7 @@ pub struct Answer {
 }
 
 impl Answer {
-    pub fn parse(datagram: &mut Cursor<&[u8]>) -> Result<Answer> {
+    pub fn parse(datagram: &mut Cursor<&[u8]>) -> Result<Self> {
         let domain = parse_domain(datagram)?;
 
         let record_type = datagram.read_u16()?;
@@ -27,7 +27,7 @@ impl Answer {
 
         let data = datagram.read_bytes(data_length)?;
 
-        Ok(Answer {
+        Ok(Self {
             domain,
             record_type,
             class,
@@ -42,7 +42,7 @@ impl Answer {
         result.extend(self.record_type.to_be_bytes());
         result.extend(self.class.to_be_bytes());
         result.extend(self.ttl.to_be_bytes());
-        result.extend((self.data.len() as u16).to_be_bytes());
+        result.extend(u16::try_from(self.data.len())?.to_be_bytes());
         result.extend_from_slice(&self.data);
 
         Ok(result)

src/dns/domainname.rs

@@ -57,7 +57,7 @@ pub fn domain_to_bytes(domain: &str) -> Result<Vec<u8>> {
         return Ok(result);
     }
 
-    for part in domain.split(".") {
+    for part in domain.split('.') {
         if part.len() > 63 {
             bail!("domain label too long");
         }
@@ -65,7 +65,7 @@ pub fn domain_to_bytes(domain: &str) -> Result<Vec<u8>> {
             bail!("empty domain label");
         }
 
-        result.push(part.len() as u8);
+        result.push(u8::try_from(part.len())?);
         result.extend_from_slice(part.as_bytes());
     }
     result.push(0);

src/dns/header.rs

@@ -5,6 +5,7 @@ use anyhow::Result;
 use crate::ext::CursorExt;
 
 #[derive(Debug, Clone)]
+#[allow(clippy::struct_excessive_bools)]
 pub struct Header {
     pub transaction_id: u16,
     pub query_response: bool,
@@ -23,7 +24,7 @@ pub struct Header {
 }
 
 impl Header {
-    pub fn parse(cursor: &mut Cursor<&[u8]>) -> Result<Header> {
+    pub fn parse(cursor: &mut Cursor<&[u8]>) -> Result<Self> {
         let transaction_id = cursor.read_u16()?;
         let flags1 = cursor.read_u8()?;
         let flags2 = cursor.read_u8()?;
@@ -32,7 +33,7 @@ impl Header {
         let number_of_authority_resource_records = cursor.read_u16()?;
         let number_of_additional_resource_records = cursor.read_u16()?;
 
-        let datagram = Header {
+        let datagram = Self {
             transaction_id,
             query_response: flags1 & (1 << 7) > 0,
             op_code: (flags1 >> 3) & 0x0F,
@@ -52,7 +53,7 @@ impl Header {
         Ok(datagram)
     }
 
-    pub fn to_bytes(&self) -> Result<Vec<u8>> {
+    pub fn to_bytes(&self) -> Vec<u8> {
         let mut buffer = [0u8; 12];
         let transaction_id = self.transaction_id.to_be_bytes();
         let number_of_questions = self.number_of_questions.to_be_bytes();
@@ -96,6 +97,6 @@ impl Header {
         buffer[10] = number_of_additional_resource_records[0];
         buffer[11] = number_of_additional_resource_records[1];
 
-        Ok(buffer.into())
+        buffer.into()
     }
 }

src/dns/message.rs

@@ -12,11 +12,11 @@ pub struct Message {
 }
 
 impl Message {
-    pub fn parse(datagram: &mut Cursor<&[u8]>) -> Result<Message> {
+    pub fn parse(datagram: &mut Cursor<&[u8]>) -> Result<Self> {
         let header = Header::parse(datagram)?;
 
-        let mut message = Message {
+        let mut message = Self {
-            header: header,
+            header,
             questions: vec![],
             answers: vec![],
         };
@@ -35,7 +35,7 @@ impl Message {
 
     pub fn to_bytes(&self) -> Result<Vec<u8>> {
         let mut result: Vec<u8> = vec![];
-        result.extend(self.header.to_bytes()?);
+        result.extend(self.header.to_bytes());
         for question in &self.questions {
             result.extend(question.to_bytes()?);
         }
@@ -45,8 +45,8 @@ impl Message {
         Ok(result)
     }
 
-    pub fn prepare_response(&self) -> Message {
+    pub fn prepare_response(&self) -> Self {
-        Message {
+        Self {
             header: Header {
                 transaction_id: self.header.transaction_id,
                 query_response: true,

src/dns/mod.rs

@@ -14,6 +14,7 @@ pub use question::*;
 
 #[cfg(test)]
 mod tests {
+    #![allow(clippy::unwrap_used)]
     use std::io::Cursor;
 
     use super::*;

src/dns/question.rs

@@ -10,21 +10,21 @@ use crate::{
 #[derive(Debug, Clone)]
 pub struct Question {
     pub domain: String,
-    pub question_type: u16,
+    pub qtype: u16,
-    pub question_class: u16,
+    pub class: u16,
 }
 
 impl Question {
-    pub fn parse(cursor: &mut Cursor<&[u8]>) -> Result<Question> {
+    pub fn parse(cursor: &mut Cursor<&[u8]>) -> Result<Self> {
         let domain = parse_domain(cursor)?;
 
         let question_type = cursor.read_u16()?;
         let question_class = cursor.read_u16()?;
 
-        let question = Question {
+        let question = Self {
             domain,
-            question_type,
+            qtype: question_type,
-            question_class,
+            class: question_class,
         };
 
         Ok(question)
@@ -32,8 +32,8 @@ impl Question {
 
     pub fn to_bytes(&self) -> Result<Vec<u8>> {
         let mut result = domain_to_bytes(&self.domain)?;
-        result.extend(self.question_type.to_be_bytes());
+        result.extend(self.qtype.to_be_bytes());
-        result.extend(self.question_class.to_be_bytes());
+        result.extend(self.class.to_be_bytes());
         Ok(result)
     }
 }

src/main.rs

@@ -1,3 +1,9 @@
+#![warn(clippy::pedantic)]
+#![warn(clippy::nursery)]
+#![warn(clippy::unwrap_used)]
+#![warn(clippy::todo)]
+#![warn(clippy::panic)]
+
 mod config;
 mod dns;
 mod ext;
@@ -11,7 +17,10 @@ use dotenv::dotenv;
 use tokio::net::UdpSocket;
 use tracing::{Instrument, Level};
 
-use crate::{config::ConfigData, dns::*};
+use crate::{
+    config::ConfigData,
+    dns::{Answer, CLASS_IN, Message, Question, RECORD_TYPE_A, RESPONSE_CODE_NXDOMAIN},
+};
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -61,17 +70,17 @@ async fn handle_datagram(
 
         let mut response = message.prepare_response();
         for question in message.questions {
-            if question.question_class != CLASS_IN {
+            if question.class != CLASS_IN {
                 tracing::error!(
                     "only IN class records are supported yet, requested: {}",
-                    question.question_class
+                    question.class
                 );
                 return Ok(());
             }
 
-            match question.question_type {
+            match question.qtype {
                 RECORD_TYPE_A => {
-                    handle_type_a_question(&config, &question, &mut response);
+                    handle_type_a_question(config, &question, &mut response);
                 }
                 qt => {
                     tracing::error!("unsupported question type, requested: {qt}");