diff options
Diffstat (limited to 'resolver/src/server.rs')
| -rw-r--r-- | resolver/src/server.rs | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/resolver/src/server.rs b/resolver/src/server.rs deleted file mode 100644 index 764b7a2..0000000 --- a/resolver/src/server.rs +++ /dev/null @@ -1,121 +0,0 @@ -use std::net::IpAddr; -use async_recursion::async_recursion; -use packet::{PacketType, Packet, Result, PacketQuestion, PacketBuffer, ResultCode}; -use tokio::net::UdpSocket; - -use crate::config::Config; - - -async fn lookup(qname: &str, qtype: PacketType, server: (IpAddr, u16)) -> Result<Packet> { - let socket = UdpSocket::bind("0.0.0.0:43210").await?; - - let mut packet = Packet::new(); - - packet.header.id = 6666; - packet.header.questions = 1; - packet.header.recursion_desired = true; - packet - .questions - .push(PacketQuestion::new(qname.to_string(), qtype)); - - let mut req_buffer = PacketBuffer::new(); - packet.write(&mut req_buffer)?; - socket.send_to(&req_buffer.buf[0..req_buffer.pos], server).await?; - - let mut res_buffer = PacketBuffer::new(); - socket.recv_from(&mut res_buffer.buf).await?; - - Packet::from_buffer(&mut res_buffer) -} - -#[async_recursion] -async fn recursive_lookup(qname: &str, qtype: PacketType, config: &Config) -> Result<Packet> { - - let mut ns = *config.get_fallback_ns(); - - loop { - println!("attempting lookup of {qtype:?} {qname} with ns {ns}"); - - let ns_copy = ns; - - let server = (ns_copy, 53); - let response = lookup(qname, qtype, server).await?; - - if !response.answers.is_empty() && response.header.rescode == ResultCode::NOERROR { - return Ok(response); - } - - if response.header.rescode == ResultCode::NXDOMAIN { - return Ok(response); - } - - if let Some(new_ns) = response.get_resolved_ns(qname) { - ns = new_ns; - - continue; - } - - let new_ns_name = match response.get_unresolved_ns(qname) { - Some(x) => x, - None => return Ok(response), - }; - - let recursive_response = recursive_lookup(new_ns_name, PacketType::A, config).await?; - - if let Some(new_ns) = recursive_response.get_random_a() { - ns = new_ns; - } else { - return Ok(response); - } - } -} - -pub async fn handle_query(socket: &UdpSocket, config: &Config) -> Result<()> { - let mut req_buffer = PacketBuffer::new(); - - let (_, src) = socket.recv_from(&mut req_buffer.buf).await?; - - let mut request = Packet::from_buffer(&mut req_buffer)?; - - let mut packet = Packet::new(); - packet.header.id = request.header.id; - packet.header.recursion_desired = true; - packet.header.recursion_available = true; - packet.header.response = true; - - if let Some(question) = request.questions.pop() { - println!("Received query: {question:?}"); - - if let Ok(result) = recursive_lookup(&question.name, question.qtype, config).await { - packet.questions.push(question.clone()); - packet.header.rescode = result.header.rescode; - - for rec in result.answers { - println!("Answer: {rec:?}"); - packet.answers.push(rec); - } - for rec in result.authorities { - println!("Authority: {rec:?}"); - packet.authorities.push(rec); - } - for rec in result.resources { - println!("Resource: {rec:?}"); - packet.resources.push(rec); - } - } else { - packet.header.rescode = ResultCode::SERVFAIL; - } - } else { - packet.header.rescode = ResultCode::FORMERR; - } - - let mut res_buffer = PacketBuffer::new(); - packet.write(&mut res_buffer)?; - - let len = res_buffer.pos(); - let data = res_buffer.get_range(0, len)?; - - socket.send_to(data, src).await?; - - Ok(()) -}
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