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
+34 -6
View File
@@ -49,6 +49,10 @@ pub struct PeerActor {
dispatcher: Option<MessageDispatcher<PeerMessage>>,
dispatcher_receiver: Option<Receiver<PeerMessage>>,
queued_messages: Vec<PeerMessage>,
own_username: String,
/// True when we initiated this connection (no stream supplied at
/// construction), so we must send a `PeerInit` once connected.
outbound: bool,
}
impl PeerActor {
@@ -58,7 +62,9 @@ impl PeerActor {
stream: Option<TcpStream>,
reader: Option<MessageReader>,
client_channel: Sender<ClientOperation>,
own_username: String,
) -> Self {
let outbound = stream.is_none();
let connection_state = if stream.is_some() {
ConnectionState::Connected
} else {
@@ -75,6 +81,8 @@ impl PeerActor {
dispatcher: None,
dispatcher_receiver: None,
queued_messages: Vec::new(),
own_username,
outbound,
}
}
@@ -529,8 +537,12 @@ impl PeerActor {
}
fn on_connection_established(&mut self) {
let (username, token) = match self.peer.read_safe() {
Ok(peer) => (peer.username.clone(), peer.token),
let (username, connection_type, token) = match self.peer.read_safe() {
Ok(peer) => (
peer.username.clone(),
peer.connection_type.clone(),
peer.token,
),
Err(e) => {
error!(
"[peer_actor] on_connection_established peer lock: {}",
@@ -544,11 +556,19 @@ impl PeerActor {
return;
};
if let Some(token) = token {
let handshake_msg = MessageFactory::build_watch_user(token);
if let Err(e) = stream.write_all(&handshake_msg.get_data()) {
// Connections we initiated must announce themselves with a PeerInit
// (peer code 1); inbound peers already sent us theirs, so we stay
// silent for them. `get_buffer` prepends the length prefix the peer's
// MessageReader expects.
if self.outbound {
let init = MessageFactory::build_peer_init_message(
&self.own_username,
connection_type,
token.unwrap_or(0),
);
if let Err(e) = stream.write_all(&init.get_buffer()) {
error!(
"[peer:{}] Failed to send watch user handshake: {}",
"[peer:{}] Failed to send PeerInit handshake: {}",
username, e
);
self.disconnect_with_error(e);
@@ -563,6 +583,14 @@ impl PeerActor {
self.handle_message(msg);
}
// Tell the client the control connection is live so any downloads
// queued for this peer can now be requested over a handshaken stream.
if self.outbound {
let _ = self
.client_channel
.send(ClientOperation::PeerConnected(username));
}
if let Some(ref handle) = self.self_handle {
handle.send(PeerMessage::ProcessRead).ok();
}
+11 -2
View File
@@ -15,6 +15,7 @@ pub struct PeerRegistry {
peers: Arc<Mutex<HashMap<String, ActorHandle<PeerMessage>>>>,
actor_system: Arc<ActorSystem>,
client_channel: Sender<ClientOperation>,
own_username: String,
}
impl PeerRegistry {
@@ -22,11 +23,13 @@ impl PeerRegistry {
pub fn new(
actor_system: Arc<ActorSystem>,
client_channel: Sender<ClientOperation>,
own_username: String,
) -> Self {
Self {
peers: Arc::new(Mutex::new(HashMap::new())),
actor_system,
client_channel,
own_username,
}
}
@@ -38,8 +41,13 @@ impl PeerRegistry {
) -> Result<ActorHandle<PeerMessage>, String> {
let username = peer.username.clone();
let actor =
PeerActor::new(peer, stream, reader, self.client_channel.clone());
let actor = PeerActor::new(
peer,
stream,
reader,
self.client_channel.clone(),
self.own_username.clone(),
);
let handle =
self.actor_system.spawn_with_handle(actor, |actor, handle| {
@@ -157,6 +165,7 @@ impl Clone for PeerRegistry {
peers: self.peers.clone(),
actor_system: self.actor_system.clone(),
client_channel: self.client_channel.clone(),
own_username: self.own_username.clone(),
}
}
}
+101 -11
View File
@@ -97,6 +97,7 @@ pub enum ClientOperation {
},
SetServerSender(Sender<ServerMessage>),
PrivateMessageReceived(UserMessage),
PeerConnected(String),
}
pub struct ClientContext {
pub peer_registry: Option<PeerRegistry>,
@@ -254,6 +255,26 @@ fn test_client_pause_and_resume_download() {
));
}
#[test]
fn download_without_a_connection_resolves_failed() {
// A client that never connected has no server handle and no peer registry,
// so it cannot open a connection to the peer: the download must resolve to
// Failed rather than hang Queued forever.
let client = Client::new("test-user", "test-password");
let (_download, receiver) = client
.download(
"song.mp3".to_string(),
"peer".to_string(),
100,
"test".to_string(),
)
.expect("download() should return a handle");
assert!(matches!(
receiver.recv_timeout(Duration::from_secs(1)),
Ok(DownloadStatus::Failed)
));
}
#[test]
fn test_client_removes_only_queued_downloads() {
let client = Client::new("test-user", "test-password");
@@ -375,8 +396,11 @@ impl Client {
let mut ctx = self.context.write_safe()?;
ctx.sender = Some(sender.clone());
let peer_registry =
PeerRegistry::new(ctx.actor_system.clone(), sender.clone());
let peer_registry = PeerRegistry::new(
ctx.actor_system.clone(),
sender.clone(),
self.username.clone(),
);
ctx.peer_registry = Some(peer_registry);
let listen_sender = sender.clone();
@@ -461,6 +485,23 @@ impl Client {
Ok(())
}
/// Ask the server for a peer's address and open a direct control
/// connection to it. Downloads queued for that peer are sent automatically
/// once the connection is established.
///
/// # Errors
/// Returns [`SoulseekRs::NotConnected`] if the client is not connected.
pub fn connect_peer(&self, username: &str) -> Result<()> {
let handle = self
.server_handle
.as_ref()
.ok_or(SoulseekRs::NotConnected)?;
handle
.send(ServerMessage::GetPeerAddress(username.to_string()))
.map_err(|_| SoulseekRs::NotConnected)?;
Ok(())
}
/// Remove and return all private messages received since the last call.
#[must_use]
pub fn take_private_messages(&self) -> Vec<UserMessage> {
@@ -684,18 +725,29 @@ impl Client {
let mut context = self.context.write_safe()?;
context.add_download(download.clone());
let download_initiated =
if let Some(ref registry) = context.peer_registry {
registry
.queue_upload(&username, download.filename.clone())
.is_ok()
} else {
false
};
// If we already have a control connection to this peer, queue the
// upload immediately. Otherwise open one directly (server GetPeerAddress
// → outbound PeerInit → PeerConnected → the queued upload is flushed).
let peer_registered = context
.peer_registry
.as_ref()
.is_some_and(|r| r.contains(&username));
let queued_now = peer_registered
&& context.peer_registry.as_ref().is_some_and(|r| {
r.queue_upload(&username, download.filename.clone()).is_ok()
});
drop(context);
if !download_initiated {
let failed = if peer_registered {
!queued_now
} else {
// No existing connection: initiate one. Only a genuinely
// unconnected client (no server handle) fails outright here.
self.connect_peer(&username).is_err()
};
if failed {
let _ = download.sender.send(DownloadStatus::Failed);
self.context
.write_safe()?
@@ -1187,6 +1239,44 @@ impl Client {
e
),
},
ClientOperation::PeerConnected(username) => {
// An outbound control connection just handshook.
// Flush any downloads that were queued for this
// peer while we were still connecting. Collect
// under a read guard, then act without it held.
let (registry, files): (
Option<PeerRegistry>,
Vec<String>,
) = match client_context.read_safe() {
Ok(ctx) => (
ctx.peer_registry.clone(),
ctx.get_downloads()
.iter()
.filter(|d| {
d.username == username
&& matches!(
d.status,
DownloadStatus::Queued
)
})
.map(|d| d.filename.clone())
.collect(),
),
Err(e) => {
error!(
"[client] PeerConnected read: {}",
e
);
continue;
}
};
if let Some(registry) = registry {
for filename in files {
let _ = registry
.queue_upload(&username, filename);
}
}
}
}
}
Err(e) => {
@@ -142,7 +142,6 @@ impl MessageFactory {
.clone()
}
#[allow(dead_code)]
#[must_use]
pub fn build_peer_init_message(
own_username: &str,
@@ -184,6 +183,22 @@ fn test_build_login_message() {
assert_eq!(expect, message.get_data());
}
#[test]
fn test_build_peer_init_message() {
use crate::peer::ConnectionType;
let message =
MessageFactory::build_peer_init_message("bob", ConnectionType::P, 7);
// [1][len=3]"bob"[len=1]"P"[token=7] — no length prefix in get_data()
let expect: Vec<u8> = [
1, // PeerInit code (int8)
3, 0, 0, 0, 98, 111, 98, // username "bob"
1, 0, 0, 0, 80, // connection type "P"
7, 0, 0, 0, // token
]
.to_vec();
assert_eq!(expect, message.get_data());
}
#[test]
fn test_build_message_user() {
let message = MessageFactory::build_message_user("bob", "hi");
+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);
}