✨ feat: Return version number for dummy domains version, ver

and v

Author: Stenstromen

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "rustyalias"
-version = "1.5.3"
+version = "1.6.0"
 edition = "2021"
 readme = "README.md"
 rust-version = "1.79.0"
@@ -10,4 +10,5 @@ description = "Wildcard DNS for any IP Address"
 
 [dependencies]
 log = "0.4"
-env_logger = "0.11"
+env_logger = "0.11"
+toml = "0.8"

Cargo.toml

@@ -1,5 +1,7 @@
 use std::env;
+use std::fs;
 use std::net::Ipv4Addr;
+use toml::Value;
 
 #[derive(Clone)]
 pub struct Config {
@@ -12,10 +14,24 @@ pub struct Config {
     pub retry: u32,
     pub expire: u32,
     pub minimum: u32,
+    pub version: String,
 }
 
 impl Config {
     pub fn from_env() -> Self {
+        let version = fs::read_to_string("Cargo.toml")
+            .ok()
+            .and_then(|content| {
+                content.parse::<Value>().ok().and_then(|value| {
+                    value
+                        .get("package")
+                        .and_then(|pkg| pkg.get("version"))
+                        .and_then(|ver| ver.as_str())
+                        .map(String::from)
+                })
+            })
+            .unwrap_or_else(|| "unknown".to_string());
+
         Self {
             glue_name: env::var("GLUE_NAME").unwrap_or_else(|_| "ns.example.com".to_string()),
             glue_ip: env::var("GLUE_IP")
@@ -45,6 +61,7 @@ impl Config {
                 .unwrap_or_else(|_| "3600".to_string())
                 .parse()
                 .expect("Invalid MINIMUM"),
+            version,
         }
     }
 }

src/config.rs

@@ -1,5 +1,5 @@
 use super::ip_parser::interpret_ip;
-use super::response::{build_response, build_soa_response, SoaParams};
+use super::response::{build_response, build_soa_response, build_txt_response, SoaParams};
 use crate::config::Config;
 use log::{debug, info};
 use std::io::Result as IoResult;
@@ -23,6 +23,14 @@ pub fn handle_query(
             );
             let response = build_response(query, Some((&config.glue_name, config.glue_ip)), None);
             socket.send_to(&response, src)?;
+        } else if domain.eq_ignore_ascii_case("version")
+            || domain.eq_ignore_ascii_case("ver")
+            || domain.eq_ignore_ascii_case("v")
+        {
+            info!("Client [{}] requested version TXT record", src);
+            let nameandversion = format!("RustyAlias v{}", config.version);
+            let response = build_txt_response(query, &nameandversion);
+            socket.send_to(&response, src)?;
         } else if let Some(ip) = interpret_ip(&domain) {
             info!("Client [{}] resolved [{}] to [{:?}]", src, domain, ip);
             let response = build_response(query, None, Some(ip));
@@ -112,6 +120,9 @@ pub fn handle_query_internal(query: &[u8], src: SocketAddr, config: &Config) ->
                 src, domain, config.glue_ip
             );
             build_response(query, Some((&config.glue_name, config.glue_ip)), None)
+        } else if domain.eq_ignore_ascii_case("version") || domain.eq_ignore_ascii_case("ver") {
+            info!("Client [{}] requested version TXT record", src);
+            build_txt_response(query, &config.version)
         } else if let Some(ip) = interpret_ip(&domain) {
             info!("Client [{}] resolved [{}] to [{:?}]", src, domain, ip);
             build_response(query, None, Some(ip))

src/dns/query.rs

@@ -124,3 +124,31 @@ pub fn encode_domain_name(name: &str) -> Vec<u8> {
     encoded.push(0); // End of the domain name
     encoded
 }
+
+pub fn build_txt_response(query: &[u8], txt_data: &str) -> Vec<u8> {
+    let mut response: Vec<u8> = Vec::with_capacity(512);
+    response.extend(&query[0..2]); // ID
+    response.extend(&[0x81, 0x80]); // Flags: response, authoritative
+    response.extend(&query[4..6]); // QDCOUNT
+    response.extend(&[0x00, 0x01]); // ANCOUNT
+    response.extend(&[0x00, 0x00]); // NSCOUNT
+    response.extend(&[0x00, 0x00]); // ARCOUNT
+
+    let question_end = 12 + query[12..].iter().position(|&x| x == 0).unwrap() + 5;
+    response.extend(&query[12..question_end]); // Original question
+
+    // TXT Record
+    response.extend(&[0xC0, 0x0C]); // Pointer to the domain name
+    response.extend(&[0x00, 0x10]); // Type TXT
+    response.extend(&[0x00, 0x01]); // Class IN
+    response.extend(&[0x00, 0x00, 0x00, 0x3C]); // TTL: 60 seconds
+
+    // TXT data format: <length><string>
+    let txt_bytes = txt_data.as_bytes();
+    response.extend(&(txt_bytes.len() as u16 + 1).to_be_bytes()); // RDLENGTH
+    response.push(txt_bytes.len() as u8); // Length of the string
+    response.extend(txt_bytes); // The actual string
+
+    debug!("Built TXT response: {:?}", response);
+    response
+}