Files
NLnetLabs-domain/tests/net-client.rs
Leo BlöcherandGitHub 8f1df93ba1 Fix dropped responses when DNS stream encounters EOF (#568)
* Add regression test for immediate EOF on stream

* Fix dropped responses when DNS stream encounters EOF

The `stream::Transport` loop did not account for responses that had been
added to the reply channel prior to `reader_fut` returning. If a server
sent a response and immediately closed the stream afterwards, that
response was lost. I fixed the bug by adding an explicit check for any
remaining items from `reply_receiver` in the `reader_fut` select branch.

Additionally, the `Transport::error` function did not await the futures
returned by `ReplySender::send`. This meant the errors were never sent
and instead the channel closed without any message. I fixed that by
making `Transort::error` an async fn.

The PR additionally contains a regression test. Running it without the
fix fails, but with the fixes it passes. I did not use stelline for this
test as it requires a very specific order of IO events on the
connection.
2025-09-15 11:07:20 +02:00

212 lines
6.8 KiB
Rust

#![cfg(feature = "net")]
use domain::stelline::client::do_client_simple;
use domain::stelline::client::CurrStepValue;
use domain::stelline::connect::Connect;
use domain::stelline::connection::Connection;
use domain::stelline::dgram::Dgram;
use domain::stelline::parse_stelline::parse_file;
// use domain::net::client::clock::{Clock, FakeClock};
use domain::net::client::dgram;
use domain::net::client::dgram_stream;
use domain::net::client::multi_stream;
use domain::net::client::redundant;
use domain::net::client::request::{
GetResponse as _, RequestMessage, RequestMessageMulti,
};
use domain::net::client::stream;
use std::fs::File;
use std::net::{IpAddr, Ipv4Addr, SocketAddr};
use std::str::FromStr;
use std::sync::Arc;
use tokio::net::TcpStream;
const TEST_FILE: &str = "test-data/client/basic.rpl";
#[test]
fn dgram() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let conn = Dgram::new(stelline.clone(), step_value.clone());
let dgram = dgram::Connection::new(conn);
do_client_simple(&stelline, &step_value, dgram).await;
});
}
#[test]
fn single() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let conn = Connection::new(stelline.clone(), step_value.clone());
let (octstr, transport) =
stream::Connection::<_, RequestMessageMulti<Vec<u8>>>::new(conn);
tokio::spawn(async move {
transport.run().await;
});
do_client_simple(&stelline, &step_value, octstr).await;
});
}
#[test]
fn multi() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let multi_conn = Connect::new(stelline.clone(), step_value.clone());
let (ms, ms_tran) = multi_stream::Connection::new(multi_conn);
tokio::spawn(async move {
ms_tran.run().await;
println!("multi conn run terminated");
});
do_client_simple(&stelline, &step_value, ms).await;
});
}
#[test]
fn dgram_stream() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let conn = Dgram::new(stelline.clone(), step_value.clone());
let multi_conn = Connect::new(stelline.clone(), step_value.clone());
let (ds, tran) = dgram_stream::Connection::new(conn, multi_conn);
tokio::spawn(async move {
tran.run().await;
println!("dgram_stream conn run terminated");
});
do_client_simple(&stelline, &step_value, ds).await;
});
}
#[test]
fn redundant() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let multi_conn = Connect::new(stelline.clone(), step_value.clone());
let (ms, ms_tran) = multi_stream::Connection::new(multi_conn);
tokio::spawn(async move {
ms_tran.run().await;
println!("multi conn run terminated");
});
// Redundant add previous connection.
let (redun, transp) = redundant::Connection::new();
let run_fut = transp.run();
tokio::spawn(async move {
run_fut.await;
println!("redundant conn run terminated");
});
redun.add(Box::new(ms.clone())).await.unwrap();
do_client_simple(&stelline, &step_value, redun).await;
});
}
#[test]
#[ignore]
// Connect directly to the internet. Disabled by default.
fn tcp() {
tokio_test::block_on(async {
let file = File::open(TEST_FILE).unwrap();
let stelline = parse_file(file, TEST_FILE);
let step_value = Arc::new(CurrStepValue::new());
let server_addr =
SocketAddr::new(IpAddr::from_str("9.9.9.9").unwrap(), 53);
let tcp_conn = match TcpStream::connect(server_addr).await {
Ok(conn) => conn,
Err(err) => {
panic!(
"TCP Connection to {server_addr} failed: {err}, exiting"
);
}
};
let (tcp, transport) = stream::Connection::<
_,
RequestMessageMulti<Vec<u8>>,
>::new(tcp_conn);
tokio::spawn(async move {
transport.run().await;
println!("single TCP run terminated");
});
do_client_simple(&stelline, &step_value, tcp).await;
});
}
/// Regression test: Ensure responses are not lost when a stream closes.
#[test]
fn stream_immediate_eof() {
use domain::base::{iana::Rcode, MessageBuilder, Name, Rtype};
use domain::rdata::A;
use futures_util::FutureExt as _;
use tokio::io::{AsyncReadExt as _, AsyncWriteExt as _};
// Query and response for `a.b.c. IN A`
let domain_name: Name<Vec<u8>> = "a.b.c.".parse().unwrap();
let mut query = MessageBuilder::new_vec().question();
query.push((&domain_name, Rtype::A)).unwrap();
let mut response = MessageBuilder::new_stream_vec()
.start_answer(&query.as_message(), Rcode::NOERROR)
.unwrap();
response
.push((&domain_name, 3600, A::new(Ipv4Addr::LOCALHOST)))
.unwrap();
let response = response.finish().into_target();
let query = RequestMessage::new(query).unwrap();
tokio_test::block_on(async move {
let (client, mut server) = tokio::io::duplex(response.len());
tokio::spawn(async move {
// Read the entire query to avoid breaking the client's write half.
let len = server.read_u16().await.unwrap();
let _ = server.read_exact(&mut vec![0; len as usize]).await;
// Write the entire response in one shot. This is important so that
// we can be sure the client sees the response and EOF at the same time.
server
.write_all(&response)
.now_or_never()
.expect("write should not return pending")
.expect("client dead?");
drop(server);
});
let (conn, transport) = stream::Connection::<
_,
RequestMessageMulti<Vec<u8>>,
>::new(client);
tokio::spawn(async move {
transport.run().await;
println!("single stream run terminated");
});
let resp = conn.get_request(query).get_response().await;
let answer = resp.expect("request should yield a response");
assert!(answer.no_error());
});
}