feat: direct peer connections — download() connects to unconnected peers

Implement the DIRECT connection-initiation mode so a download can target a
peer the client is not already connected to:

- Fix the outbound peer handshake. on_connection_established sent
  build_watch_user() (a server WatchUser message, wrongly framed with
  get_data()) for outbound connections; it now sends a proper length-prefixed
  PeerInit (peer code 1) with our own username. own_username is plumbed in
  via PeerRegistry -> PeerActor; inbound peers (outbound=false) are unchanged.
- download() now auto-connects: if there is no control connection to the peer
  it sends GetPeerAddress and defers the QueueUpload until the outbound stream
  handshakes, signalled by a new ClientOperation::PeerConnected. A never-
  connected client still resolves the download to Failed (unit test).
- Add Client::connect_peer(username) to open/pre-warm a control connection.

Verified end to end against soulfind: a_file_downloads_from_a_peer_via_direct_connection
logs a mock peer into the server, advertises its port via SetWaitPort, and the
client resolves the address, dials it, and downloads the file — bytes match.
The F-serve leg is shared with the passive-download mock.
This commit is contained in:
michel
2026-07-19 17:12:17 +02:00
parent 06cd638736
commit e4093b1ea8
5 changed files with 387 additions and 29 deletions
+225 -9
View File
@@ -26,6 +26,7 @@ use std::sync::mpsc::Sender;
use std::time::{Duration, Instant};
use soulseek_rs::message::Message;
use soulseek_rs::message::server::MessageFactory;
use soulseek_rs::{Client, ClientSettings, DownloadStatus, PeerAddress};
/// A Soulseek server to test against: either a child soulfind process we
@@ -449,21 +450,36 @@ fn run_mock_uploader(cfg: &MockUpload) -> std::io::Result<()> {
}
}
// 5. F (file) connection. PeerInit(F) and the 4-byte transfer token go in a
// single write so the token lands in the listener's read buffer, where
// the download is looked up by token.
let mut f = connect_retry(&cfg.listen_addr, Duration::from_secs(5))?;
// 5. Open the F (file) connection to the downloader's listener and stream.
serve_file_over_f(
&cfg.listen_addr,
&cfg.peer_username,
cfg.token,
&cfg.content,
)
}
/// Open an F (file transfer) connection to `downloader_addr` and stream
/// `content`. PeerInit(F) and the 4-byte transfer token are written together so
/// the token lands in the listener's read buffer, where the download is looked
/// up by token; the downloader then sends an 8-byte START_DOWNLOAD offset before
/// we send the bytes.
fn serve_file_over_f(
downloader_addr: &str,
username: &str,
token: u32,
content: &[u8],
) -> std::io::Result<()> {
let mut f = connect_retry(downloader_addr, Duration::from_secs(5))?;
f.set_read_timeout(Some(Duration::from_secs(10)))?;
let mut init = peer_init_bytes(&cfg.peer_username, "F", cfg.token);
init.extend_from_slice(&cfg.token.to_le_bytes());
let mut init = peer_init_bytes(username, "F", token);
init.extend_from_slice(&token.to_le_bytes());
f.write_all(&init)?;
f.flush()?;
// 6. The downloader replies with an 8-byte START_DOWNLOAD offset, then we
// stream the file bytes.
let mut start = [0u8; 8];
f.read_exact(&mut start)?;
f.write_all(&cfg.content)?;
f.write_all(content)?;
f.flush()?;
// Keep the connection open briefly so the reader drains everything.
@@ -567,3 +583,203 @@ fn a_file_downloads_from_a_peer_over_p_and_f_connections() {
let _ = std::fs::remove_dir_all(&download_dir);
}
// ---------------------------------------------------------------------------
// Direct-connection download: the client initiates the peer connection.
//
// Here the mock is a server-registered peer. It logs in to soulfind and
// advertises a listen port (SetWaitPort), so when our client asks the server
// for the peer's address (GetPeerAddress) and dials it directly, the mock
// accepts that inbound P connection and then serves the file. This exercises
// the outbound PeerInit handshake and the auto-connecting download() path.
// ---------------------------------------------------------------------------
struct MockDirectUpload {
server_addr: String,
username: String,
password: String,
listen_port: u16,
downloader_listen_addr: String,
downloader_username: String,
filename: String,
content: Vec<u8>,
token: u32,
ready: Sender<()>,
}
fn run_mock_direct_peer(cfg: &MockDirectUpload) -> std::io::Result<()> {
// 1. Log in to the server so it knows this user is online.
let mut srv = connect_retry(&cfg.server_addr, Duration::from_secs(5))?;
srv.set_read_timeout(Some(Duration::from_secs(10)))?;
srv.write_all(
&MessageFactory::build_login_message(&cfg.username, &cfg.password)
.get_buffer(),
)?;
srv.flush()?;
loop {
let msg = read_framed(&mut srv)?;
if msg.get_message_code() == 1 {
break; // login response
}
}
// 2. Bind the peer listener, then advertise its port so the server can hand
// our address to the downloader. Bind all interfaces: soulfind reports
// the host's LAN address (not 127.0.0.1), and the downloader dials that.
let listener = std::net::TcpListener::bind(("0.0.0.0", cfg.listen_port))?;
srv.write_all(
&MessageFactory::build_set_wait_port_message(cfg.listen_port)
.get_buffer(),
)?;
srv.flush()?;
let _ = cfg.ready.send(());
// 3. Accept the downloader's inbound P (control) connection and validate its
// PeerInit (peer code 1, int8 code so the fields start at offset 5). The
// accept is bounded so a misrouted connection fails the test instead of
// hanging it.
listener.set_nonblocking(true)?;
let accept_deadline = Instant::now() + Duration::from_secs(15);
let (mut p, _addr) = loop {
match listener.accept() {
Ok(pair) => break pair,
Err(ref e) if e.kind() == std::io::ErrorKind::WouldBlock => {
if Instant::now() >= accept_deadline {
return Err(std::io::Error::new(
std::io::ErrorKind::TimedOut,
"no inbound P connection from the downloader",
));
}
std::thread::sleep(Duration::from_millis(50));
}
Err(e) => return Err(e),
}
};
p.set_nonblocking(false)?;
p.set_read_timeout(Some(Duration::from_secs(10)))?;
let mut init = read_framed(&mut p)?;
assert_eq!(init.get_message_code(), 1, "expected inbound PeerInit");
init.set_pointer(5);
assert_eq!(init.read_string(), cfg.downloader_username, "PeerInit user");
assert_eq!(init.read_string(), "P", "PeerInit connection type");
// 4. Negotiate the transfer exactly as in the passive path.
loop {
let mut msg = read_framed(&mut p)?;
if msg.get_message_code() == 43 {
msg.set_pointer(8);
let _requested = msg.read_string();
break;
}
}
let mut tr = Message::new();
tr.write_int32(40)
.write_int32(1)
.write_int32(cfg.token)
.write_string(&cfg.filename)
.write_int64(cfg.content.len() as u64);
p.write_all(&tr.get_buffer())?;
p.flush()?;
loop {
let msg = read_framed(&mut p)?;
if msg.get_message_code() == 41 {
break; // TransferResponse
}
}
// 5. Stream the bytes over an F connection to the downloader's listener.
// `srv` stays in scope so the peer remains online for the whole transfer.
serve_file_over_f(
&cfg.downloader_listen_addr,
&cfg.username,
cfg.token,
&cfg.content,
)
}
#[test]
fn a_file_downloads_from_a_peer_via_direct_connection() {
let server = server_or_skip!();
// Downloader with a listener enabled (needed for the F leg).
let client_port = free_port().expect("free client listen port");
let mut client = Client::with_settings(server.listening_settings(
"e2e_direct_dl",
"pw",
client_port,
));
client.connect().expect("connect");
assert!(client.login().expect("login"));
let mock_port = free_port().expect("free mock listen port");
let filename = "direct_song.mp3";
let content: Vec<u8> = (0..2000u32).map(|i| (i % 251) as u8).collect();
let size = content.len() as u64;
let token = 515_151_u32;
let download_dir = unique_download_dir();
let (ready_tx, ready_rx) = std::sync::mpsc::channel();
let cfg = MockDirectUpload {
server_addr: format!("{}:{}", server.host, server.port),
username: "e2e_directpeer".to_string(),
password: "pw".to_string(),
listen_port: mock_port,
downloader_listen_addr: format!("127.0.0.1:{client_port}"),
downloader_username: "e2e_direct_dl".to_string(),
filename: filename.to_string(),
content: content.clone(),
token,
ready: ready_tx,
};
let uploader = std::thread::spawn(move || {
if let Err(e) = run_mock_direct_peer(&cfg) {
eprintln!("[mock direct peer] {e}");
}
});
ready_rx
.recv_timeout(Duration::from_secs(10))
.expect("mock direct peer ready");
// Let the server finish processing SetWaitPort before we resolve the address.
std::thread::sleep(Duration::from_millis(1000));
// Target the plain username so download() takes the direct-connect path.
let (_download, status_rx) = client
.download(
filename.to_string(),
"e2e_directpeer".to_string(),
size,
download_dir.display().to_string(),
)
.expect("start download");
let mut completed = false;
let deadline = Instant::now() + Duration::from_secs(20);
while Instant::now() < deadline {
match status_rx.recv_timeout(Duration::from_millis(500)) {
Ok(DownloadStatus::Completed) => {
completed = true;
break;
}
Ok(DownloadStatus::Failed | DownloadStatus::TimedOut) => break,
_ => {}
}
if client
.get_all_downloads()
.iter()
.any(|d| matches!(d.status, DownloadStatus::Completed))
{
completed = true;
break;
}
}
let _ = uploader.join();
assert!(completed, "the direct download should reach Completed");
let written = std::fs::read(download_dir.join(filename))
.expect("downloaded file should exist");
assert_eq!(written, content, "downloaded bytes should match the source");
let _ = std::fs::remove_dir_all(&download_dir);
}