#![allow(dead_code)]
use hickory_proto::{
op::{Message, ResponseCode, header::MessageType, op_code::OpCode, query::Query},
rr::{Name, RData, record_type::RecordType},
};
use std::{net::IpAddr, str::FromStr};
pub fn build_dns_query(domain: &str, query_type: RecordType, used_by_tcp: bool) -> Result<Vec<u8>, String> {
let name = Name::from_str(domain).map_err(|e| e.to_string())?;
let query = Query::query(name, query_type);
let mut msg = Message::new();
msg.add_query(query)
.set_id(rand::random::<u16>())
.set_op_code(OpCode::Query)
.set_message_type(MessageType::Query)
.set_recursion_desired(true);
let mut msg_buf = msg.to_vec().map_err(|e| e.to_string())?;
if used_by_tcp {
let mut buf = (msg_buf.len() as u16).to_be_bytes().to_vec();
buf.append(&mut msg_buf);
Ok(buf)
} else {
Ok(msg_buf)
}
}
pub fn extract_ipaddr_from_dns_message(message: &Message) -> Result<IpAddr, String> {
if message.response_code() != ResponseCode::NoError {
return Err(format!("{:?}", message.response_code()));
}
let mut cname = None;
for answer in message.answers() {
match answer.data() {
RData::A(addr) => {
return Ok(IpAddr::V4((*addr).into()));
}
RData::AAAA(addr) => {
return Ok(IpAddr::V6((*addr).into()));
}
RData::CNAME(name) => {
cname = Some(name.to_utf8());
}
_ => {}
}
}
if let Some(cname) = cname {
return Err(cname);
}
Err(format!("{:?}", message.answers()))
}
pub fn extract_domain_from_dns_message(message: &Message) -> Result<String, String> {
let query = message.queries().first().ok_or("DnsRequest no query body")?;
let name = query.name().to_string();
Ok(name)
}
pub fn parse_data_to_dns_message(data: &[u8], used_by_tcp: bool) -> Result<Message, String> {
if used_by_tcp {
if data.len() < 2 {
return Err("invalid dns data".into());
}
let len = u16::from_be_bytes([data[0], data[1]]) as usize;
let data = data.get(2..len + 2).ok_or("invalid dns data")?;
return parse_data_to_dns_message(data, false);
}
let message = Message::from_vec(data).map_err(|e| e.to_string())?;
Ok(message)
}