Files
alkhttp/src/websocket/upgrade.rs
T

551 lines
21 KiB
Rust

//! The WS upgrade route (`/alk/channels`, ADR-067) and the channels
//! session it establishes — the server producer half.
//!
//! Per `docs/architecture/websocket.md`: bearer auth on the upgrade
//! request (`401` without a resolvable token — the same
//! `resolve_from_token` path as any HTTP request), then upgrade →
//! WS↔byte-stream adapter → `Connection::from_bidi(ws_stream,
//! b"alk/channels")` → alkcall `ChannelsAdapter` (the channels accept
//! path). The `install_channel_zero` hook constructs channel 0's
//! `CallConnection` (the identity rides the channels-layer
//! `Connection`) and runs the shared `Dispatcher::run_loop_single_stream`.
use std::collections::HashMap;
use std::sync::atomic::{AtomicU64, Ordering};
use std::sync::Arc;
use alkcall::channels::adapter::ChannelsAdapter;
use alkcall::channels::policy::{ChannelLifecyclePolicy, NoCap};
use alkcall::core::auth::{AuthContext, Identity};
use alkcall::core::types::{Connection, ProtocolHandler};
use alkcall::registry::registration::OperationRegistry;
use axum::extract::ws::WebSocketUpgrade;
use axum::http::StatusCode;
use axum::response::{IntoResponse, Response};
use parking_lot::Mutex;
use super::byte_adapter::{
split_ws_to_bytes, WsPumps, INBOUND_WS_FRAME_CAP, INBOUND_WS_MESSAGE_CAP,
};
/// Registry of live WS session pump handles (WS-08). The upgrade
/// handler retains each session's [`WsPumps`] handle here for the
/// session's lifetime so a stuck session is evictable in-crate:
/// [`WsSessions::abort`] forces the pumps' tasks to end (the socket
/// halves close and the channels session unwinds). The handle for a
/// session is removed when the session task finishes (self-removing
/// guard), so the registry only holds live sessions. Assembly layers
/// share one instance via [`crate::server::state::RouterState`] (the
/// upgrade handler registers against it) or per-route request
/// extensions (an extension clone takes precedence).
///
/// Un-registered (default) — the upgrade runs fine and simply keeps no
/// eviction lever, matching the pre-WS-08 behavior.
#[derive(Clone, Default)]
pub struct WsSessions {
counter: Arc<AtomicU64>,
sessions: Arc<Mutex<HashMap<u64, Arc<WsPumps>>>>,
}
/// The upgrade handler's state slice: what it needs beyond the request
/// itself. Axum lifts it via `FromRef` from either full router state —
/// the adapter's [`crate::server::state::RouterState`] (carrying the
/// shared [`WsSessions`] instance) or a bare `Arc<OperationRegistry>`
/// (custom upgrade routes / integration tests get a handler-private
/// registry; eviction still works in-crate, just not shared).
#[derive(Clone)]
pub struct SessionState {
registry: Arc<OperationRegistry>,
sessions: Arc<WsSessions>,
}
impl SessionState {
/// From the plain registry state (custom upgrade routes /
/// integration tests): sessions default to a fresh [`WsSessions`]
/// private to the handler (eviction still functional in-crate but
/// not shared with the assembly layer).
pub(crate) fn from_registry(registry: &Arc<OperationRegistry>) -> Self {
Self {
registry: Arc::clone(registry),
sessions: Arc::new(WsSessions::new()),
}
}
/// From the adapter's router state: the shared [`WsSessions`]
/// instance the assembly layer can hold for eviction.
pub(crate) fn new(registry: Arc<OperationRegistry>, sessions: Arc<WsSessions>) -> Self {
Self { registry, sessions }
}
pub(crate) fn registry(&self) -> &Arc<OperationRegistry> {
&self.registry
}
pub(crate) fn sessions(&self) -> &Arc<WsSessions> {
&self.sessions
}
}
impl axum::extract::FromRef<SessionState> for Arc<OperationRegistry> {
fn from_ref(state: &SessionState) -> Self {
Arc::clone(&state.registry)
}
}
/// `FromRef` chain: a bare `Arc<OperationRegistry>` router state lifts
/// into the handler's [`SessionState`]; a full [`RouterState`] carries
/// the shared [`WsSessions`] instance and lifts through its own impl.
impl axum::extract::FromRef<Arc<OperationRegistry>> for SessionState {
fn from_ref(registry: &Arc<OperationRegistry>) -> Self {
SessionState::from_registry(registry)
}
}
impl WsSessions {
pub fn new() -> Self {
Self::default()
}
/// Abort every live session's pump tasks (forced teardown).
pub fn abort(&self) {
for (_, pumps) in self.sessions.lock().drain() {
pumps.abort();
}
}
/// Number of live sessions currently tracked.
pub fn len(&self) -> usize {
self.sessions.lock().len()
}
pub fn is_empty(&self) -> bool {
self.sessions.lock().is_empty()
}
fn insert(&self, pumps: Arc<WsPumps>) -> u64 {
let id = self.counter.fetch_add(1, Ordering::Relaxed);
self.sessions.lock().insert(id, pumps);
id
}
fn remove(&self, id: u64) {
self.sessions.lock().remove(&id);
}
}
/// The channels session for an upgraded socket: adapt → `Connection`
/// (identity attached) → `ChannelsAdapter::handle`. `policy` gates
/// data-channel opens (ADR-041). When `sessions` is `Some`, the
/// session's pump handle is registered for the session's lifetime —
/// the WS-08 eviction lever ([`WsSessions::abort`]).
pub async fn run_channels_session(
socket: axum::extract::ws::WebSocket,
registry: Arc<OperationRegistry>,
identity: Identity,
policy: Arc<dyn ChannelLifecyclePolicy>,
sessions: Option<WsSessions>,
) {
let (byte_stream, pumps) = split_ws_to_bytes(socket);
let pumps = Arc::new(pumps);
let _guard = sessions.map(|sessions| {
let id = sessions.insert(Arc::clone(&pumps));
SessionGuard { sessions, id }
});
let conn = Connection::from_bidi(byte_stream, b"alk/channels".to_vec(), None);
let _ = conn.set_identity(identity.clone());
let adapter = ChannelsAdapter::new(install_channel_zero(registry), policy);
let auth = AuthContext {
identity: Some(identity),
alpn: b"alk/channels".to_vec(),
remote_addr: None,
tls_client_fingerprint: None,
};
if let Err(e) = ProtocolHandler::handle(&adapter, conn, &auth).await {
tracing::warn!(error = %e, "channels session ended");
}
}
struct SessionGuard {
sessions: WsSessions,
id: u64,
}
impl Drop for SessionGuard {
fn drop(&mut self) {
self.sessions.remove(self.id);
}
}
/// The `install_channel_zero` hook: split channel 0's `BiStream` into
/// the shared writer + reader, construct the single-stream
/// `CallConnection`, and run the shared `Dispatcher`'s single-stream
/// loop (the alkcall `channels/client.rs` accept-side wiring pattern).
///
/// The dispatcher's token resolver is a no-op: the WS identity is
/// attached to the connection at upgrade time and
/// `Dispatcher::resolve_identity` falls back to it when the payload
/// carries no `auth_token` — the correct accept-side behavior (the
/// identity was established at upgrade time, not per-call).
fn install_channel_zero(
registry: Arc<OperationRegistry>,
) -> alkcall::channels::adapter::InstallChannelZero {
Arc::new(move |_manager, channel0_conn, auth| {
let registry = Arc::clone(&registry);
tokio::spawn(async move {
// The WS identity rides the upgrade request; propagate it to
// channel 0's `CallConnection` so the dispatcher's
// `resolve_identity` (and thus `AccessControl::check` on
// `services/list` and every operation) sees it. Without this
// the freshly constructed channel-0 `Connection` carries no
// identity and all ACL-restricted ops look unauthenticated.
if let Some(identity) = auth.identity.clone() {
let _ = channel0_conn.set_identity(identity);
}
let channel0_bidi = match channel0_conn.accept_bi().await {
Ok(s) => s,
Err(_) => return,
};
let (writer, reader) =
alkcall::protocol::connection::split_single_stream(channel0_bidi);
let call_connection = Arc::new(
alkcall::protocol::connection::CallConnection::new_single_stream(
channel0_conn,
Arc::clone(&writer),
),
);
let dispatcher = alkcall::protocol::dispatch::Dispatcher::new(
registry,
std::sync::Arc::new(NoopProvider),
);
dispatcher
.run_loop_single_stream(call_connection, reader, writer)
.await;
})
})
}
#[allow(dead_code)]
pub(crate) fn adapter_install_channel_zero(
registry: Arc<OperationRegistry>,
) -> alkcall::channels::adapter::InstallChannelZero {
install_channel_zero(registry)
}
struct NoopProvider;
impl alkcall::core::auth::IdentityProvider for NoopProvider {
fn resolve_from_fingerprint(&self, _: &str) -> Option<Identity> {
None
}
fn resolve_from_token(&self, _: &alkcall::core::auth::AuthToken) -> Option<Identity> {
None
}
}
/// Extension wrapper for the channels-policy injection point (SRV-10):
/// a deployment inserts `ChannelsPolicy(Arc<dyn ChannelLifecyclePolicy>)`
/// into the request extensions (a route layer on the WS route) to gate
/// data-channel opens per identity (ADR-041). Without the extension the
/// upgrade defaults to [`NoCap`] — the crate default for the built-in
/// surface (POC/trusted-peer semantics); assembly layers that build
/// their own upgrade route pass a stricter policy directly to
/// [`run_channels_session`].
#[derive(Clone)]
pub struct ChannelsPolicy(pub Arc<dyn ChannelLifecyclePolicy>);
/// The upgrade handler. Requires the resolved identity in request
/// extensions (stashed by [`ws_bearer_auth`]) — a WS session without
/// an identity cannot run `AccessControl::check`.
///
/// The channel lifecycle policy comes from the
/// [`ChannelsPolicy`] request extension when present, else `NoCap`.
/// The session pump handles are retained in the [`WsSessions`]
/// registry — the shared instance from the router state
/// (`RouterState::ws_sessions`) unless a request extension carries
/// one, so a stuck session stays evictable (WS-08).
pub async fn ws_upgrade_handler(
sessions: Option<axum::Extension<WsSessions>>,
axum::extract::State(state): axum::extract::State<SessionState>,
axum::Extension(identity): axum::Extension<Identity>,
policy: Option<axum::Extension<ChannelsPolicy>>,
ws_upgrade: WebSocketUpgrade,
) -> Response {
let sessions = Some(
sessions
.map(|axum::Extension(s)| s)
.unwrap_or_else(|| WsSessions::clone(state.sessions())),
);
let policy = policy
.map(|axum::Extension(p)| p.0)
.unwrap_or_else(|| Arc::new(NoCap));
let registry = Arc::clone(state.registry());
ws_upgrade
.max_frame_size(INBOUND_WS_FRAME_CAP)
.max_message_size(INBOUND_WS_MESSAGE_CAP)
.on_upgrade(move |socket| async move {
run_channels_session(socket, registry, identity, policy, sessions).await
})
}
/// Bearer-auth middleware for the WS upgrade route: resolves the token
/// via the shared [`crate::server::auth`] path and stashes the identity
/// for the upgrade handler. No token / unresolvable token → `401`
/// before the upgrade.
pub async fn ws_bearer_auth(
axum::extract::State(provider): axum::extract::State<
Arc<dyn alkcall::core::auth::IdentityProvider>,
>,
mut req: axum::http::Request<axum::body::Body>,
next: axum::middleware::Next,
) -> Response {
let identity = crate::server::auth::extract_bearer_identity(&req, provider.as_ref());
match identity {
Some(identity) => {
req.extensions_mut().insert(identity);
next.run(req).await
}
None => (StatusCode::UNAUTHORIZED, "401 Unauthorized").into_response(),
}
}
/// Test support: a minimal tokio-tungstenite WS client speaking raw
/// channels framing (`frame_channel0_chunk` / `ChunkAssembler` /
/// `FrameAssembler`). Gated behind the `test-support` feature so it
/// never ships in release builds; used by this crate's integration
/// tests and by downstream consumers testing their deployments.
#[cfg(any(test, feature = "test-support"))]
pub mod test_support {
use alkcall::protocol::wire::EventEnvelope;
use futures::StreamExt;
use tokio_tungstenite::tungstenite::client::IntoClientRequest;
use tokio_tungstenite::tungstenite::protocol::frame::coding::CloseCode;
/// Frame one `EventEnvelope` as a channel-0 chunk (8-byte chunk
/// header + 4-byte length prefix + JSON body) — the client-side
/// framing channel 0 uses over any transport.
pub fn frame_channel0_chunk(envelope: &EventEnvelope) -> Vec<u8> {
let body = serde_json::to_vec(envelope).unwrap();
let mut out = Vec::with_capacity(8 + 4 + body.len());
out.extend_from_slice(&0u32.to_be_bytes());
out.extend_from_slice(&((body.len() + 4) as u32).to_be_bytes());
out.extend_from_slice(&(body.len() as u32).to_be_bytes());
out.extend_from_slice(&body);
out
}
/// Accumulate WS binary messages into bytes and extract complete
/// chunks: (channel_id, payload).
#[derive(Default)]
pub struct ChunkAssembler {
buf: Vec<u8>,
}
impl ChunkAssembler {
pub fn new() -> Self {
Self::default()
}
pub fn push(&mut self, bytes: &[u8]) {
self.buf.extend_from_slice(bytes);
}
pub fn next_chunk(&mut self) -> Option<(u32, Vec<u8>)> {
if self.buf.len() < 8 {
return None;
}
let channel_id =
u32::from_be_bytes([self.buf[0], self.buf[1], self.buf[2], self.buf[3]]);
let len =
u32::from_be_bytes([self.buf[4], self.buf[5], self.buf[6], self.buf[7]]) as usize;
if self.buf.len() < 8 + len {
return None;
}
let payload = self.buf.drain(..8 + len).skip(8).collect();
Some((channel_id, payload))
}
}
/// Reassemble length-prefixed frames from the concatenated byte
/// stream of channel-0 chunk payloads. POC finding (OQ-01): one
/// call frame may arrive as multiple chunks (`write_frame`'s
/// prefix and body surface as separate mux payloads), so frame
/// parsing must run over the reassembled byte stream — never over
/// individual chunks.
#[derive(Default)]
pub struct FrameAssembler {
buf: Vec<u8>,
}
impl FrameAssembler {
pub fn new() -> Self {
Self::default()
}
pub fn push(&mut self, bytes: &[u8]) {
self.buf.extend_from_slice(bytes);
}
pub fn next_frame(&mut self) -> Option<EventEnvelope> {
if self.buf.len() < 4 {
return None;
}
let len =
u32::from_be_bytes([self.buf[0], self.buf[1], self.buf[2], self.buf[3]]) as usize;
if self.buf.len() < 4 + len {
return None;
}
let frame: Vec<u8> = self.buf.drain(..4 + len).collect();
serde_json::from_slice(&frame[4..]).ok()
}
}
/// Minimal WS client for tests: connect with/without a bearer
/// token, send/recv binary + text, await the close frame.
pub struct WsClient {
sink: futures::stream::SplitSink<
tokio_tungstenite::WebSocketStream<
tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
>,
tokio_tungstenite::tungstenite::Message,
>,
stream: futures::stream::SplitStream<
tokio_tungstenite::WebSocketStream<
tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
>,
>,
}
impl WsClient {
pub async fn connect_authorized(url: &str, token: &str) -> Result<Self, String> {
let mut request = url
.into_client_request()
.map_err(|e| format!("bad url: {e}"))?;
request.headers_mut().insert(
http::header::AUTHORIZATION,
http::HeaderValue::from_str(&format!("Bearer {token}"))
.map_err(|e| format!("bad token: {e}"))?,
);
let (stream, _resp): (
tokio_tungstenite::WebSocketStream<
tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
>,
_,
) = tokio_tungstenite::connect_async(request)
.await
.map_err(|e| format!("connect failed: {e}"))?;
Ok(Self::from_stream(stream))
}
/// Connect and return just the HTTP status (for negative tests).
pub async fn connect_status(url: &str, token: Option<&str>) -> Option<u16> {
let mut request = url.into_client_request().ok()?;
if let Some(t) = token {
request.headers_mut().insert(
http::header::AUTHORIZATION,
http::HeaderValue::from_str(&format!("Bearer {t}")).ok()?,
);
}
type WsStream = tokio_tungstenite::WebSocketStream<
tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
>;
type WsConnectResult = Result<
(
WsStream,
tokio_tungstenite::tungstenite::http::Response<Option<Vec<u8>>>,
),
tokio_tungstenite::tungstenite::Error,
>;
let result: WsConnectResult = tokio_tungstenite::connect_async(request).await;
match result {
Ok((stream, resp)) => {
drop(stream);
Some(resp.status().as_u16())
}
Err(tokio_tungstenite::tungstenite::Error::Http(resp)) => {
Some(resp.status().as_u16())
}
Err(_) => None,
}
}
fn from_stream(
stream: tokio_tungstenite::WebSocketStream<
tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
>,
) -> Self {
let (sink, stream) = stream.split();
Self { sink, stream }
}
pub async fn send_binary(&mut self, bytes: Vec<u8>) {
self.send_binary_piece(&bytes).await;
}
pub async fn send_binary_piece(&mut self, bytes: &[u8]) {
use futures::SinkExt;
self.sink
.send(tokio_tungstenite::tungstenite::Message::Binary(
bytes.to_vec().into(),
))
.await
.unwrap();
}
pub async fn send_text(&mut self, text: &str) {
use futures::SinkExt;
self.sink
.send(tokio_tungstenite::tungstenite::Message::Text(
text.to_string().into(),
))
.await
.unwrap();
}
/// Next binary message, or `None` on timeout/close/error.
pub async fn next_binary(&mut self, timeout: std::time::Duration) -> Option<Vec<u8>> {
use futures::StreamExt;
loop {
match tokio::time::timeout(timeout, self.stream.next()).await {
Err(_) => return None,
Ok(None) => return None,
Ok(Some(Err(_))) => return None,
Ok(Some(Ok(m))) => match m {
tokio_tungstenite::tungstenite::Message::Binary(b) => {
return Some(b.to_vec())
}
tokio_tungstenite::tungstenite::Message::Close(_) => return None,
_ => continue,
},
}
}
}
/// Await the close frame: `Some(Some(code))` close with code,
/// `Some(None)` stream ended without a close frame, `None`
/// timed out.
pub async fn next_close(&mut self, timeout: std::time::Duration) -> Option<Option<u16>> {
use futures::StreamExt;
match tokio::time::timeout(timeout, self.stream.next()).await {
Err(_) => None,
Ok(None) => Some(None),
Ok(Some(Ok(tokio_tungstenite::tungstenite::Message::Close(cf)))) => {
Some(cf.map(|f| match f.code {
CloseCode::Error => 1011,
other => other.into(),
}))
}
Ok(Some(Ok(_))) => Box::pin(self.next_close(timeout)).await,
Ok(Some(Err(_))) => Some(None),
}
}
pub async fn close(&mut self) {
use futures::SinkExt;
let _ = self.sink.close().await;
}
}
}