mtp/host/src/pipe.rs

463 lines
15 KiB
Rust

use mtp_codec::{CommunicationType, CommunicationValue, DataType, DataValue, TypeMap};
use mtp_common::{CommunicationError, PipeError};
use mtp_transport::{PipeReader, PipeWriter, Policy, TransportEvent};
use std::collections::HashMap;
use std::sync::Arc;
use std::sync::Mutex as StdMutex;
use tokio::sync::{Mutex, mpsc};
/// The sender operations needed by the transport-independent pipe protocol.
pub trait PipeSender: Clone + Send + Sync + 'static {
type Writer: tokio::io::AsyncWrite + Send + Unpin + 'static;
fn send_pipe_message(
&self,
message: &CommunicationValue,
) -> impl std::future::Future<Output = Result<(), CommunicationError>> + Send;
fn open_pipe_stream(
&self,
pipe_id: u32,
description: &str,
) -> impl std::future::Future<Output = Result<PipeWriter<Self::Writer>, CommunicationError>> + Send;
}
/// The receiver operations needed by the transport-independent pipe protocol.
pub trait PipeReceiver<P>: Clone + Send + Sync + 'static
where
P: tokio::io::AsyncRead + Send + Unpin + 'static,
{
fn receive_pipe_event(
&self,
) -> impl std::future::Future<Output = Result<TransportEvent<P>, CommunicationError>> + Send;
}
impl PipeSender for mtp_transport::Sender {
type Writer = wtransport::SendStream;
async fn send_pipe_message(
&self,
message: &CommunicationValue,
) -> Result<(), CommunicationError> {
self.send(message).await
}
async fn open_pipe_stream(
&self,
pipe_id: u32,
description: &str,
) -> Result<PipeWriter<Self::Writer>, CommunicationError> {
self.open_pipe(pipe_id, description).await
}
}
impl PipeReceiver<wtransport::RecvStream> for mtp_transport::Receiver {
async fn receive_pipe_event(
&self,
) -> Result<TransportEvent<wtransport::RecvStream>, CommunicationError> {
self.receive_event().await
}
}
impl<C> PipeSender for mtp_transport::GenericSender<C>
where
C: mtp_transport::TransportConnection,
C::SendStream: tokio::io::AsyncWrite + Send + Unpin + 'static,
{
type Writer = C::SendStream;
async fn send_pipe_message(
&self,
message: &CommunicationValue,
) -> Result<(), CommunicationError> {
self.send(message).await
}
async fn open_pipe_stream(
&self,
pipe_id: u32,
description: &str,
) -> Result<PipeWriter<Self::Writer>, CommunicationError> {
self.open_pipe(pipe_id, description).await
}
}
impl<C> PipeReceiver<C::RecvStream> for mtp_transport::GenericReceiver<C>
where
C: mtp_transport::TransportConnection,
C::RecvStream: tokio::io::AsyncRead + Send + Unpin + 'static,
{
async fn receive_pipe_event(
&self,
) -> Result<TransportEvent<C::RecvStream>, CommunicationError> {
self.receive_event().await
}
}
pub struct PipeHandle<S: PipeSender, P = wtransport::RecvStream> {
pub(crate) pipe_id: u32,
pub(crate) description: String,
pub(crate) sender: S,
pub(crate) response_rx: tokio::sync::oneshot::Receiver<Result<bool, PipeError>>,
pub(crate) dispatcher: Arc<PipeDispatcher<P>>,
pub(crate) token: Arc<()>,
}
impl<S, P> PipeHandle<S, P>
where
S: PipeSender,
P: tokio::io::AsyncRead + Send + Unpin + 'static,
{
pub fn pipe_id(&self) -> u32 {
self.pipe_id
}
pub fn description(&self) -> &str {
&self.description
}
pub async fn wait(mut self) -> Result<Option<PipeWriter<S::Writer>>, PipeError> {
let response =
tokio::time::timeout(self.dispatcher.policy.read_timeout, &mut self.response_rx).await;
match response {
Ok(Ok(Ok(true))) => self
.sender
.open_pipe_stream(self.pipe_id, &self.description)
.await
.map(Some)
.map_err(PipeError::from),
Ok(Ok(Ok(false))) => Ok(None),
Ok(Ok(Err(error))) => {
expire_pending_creation(&self.dispatcher, self.pipe_id, &self.token);
Err(error)
}
Ok(Err(_)) => {
expire_pending_creation(&self.dispatcher, self.pipe_id, &self.token);
Err(PipeError::StreamClosed)
}
Err(_) => {
expire_pending_creation(&self.dispatcher, self.pipe_id, &self.token);
Err(PipeError::HandshakeTimeout)
}
}
}
}
impl<S, P> Drop for PipeHandle<S, P>
where
S: PipeSender,
{
fn drop(&mut self) {
expire_pending_creation(&self.dispatcher, self.pipe_id, &self.token);
}
}
pub struct PipeRequest<S, P> {
pub(crate) pipe_id: u32,
pub(crate) description: String,
pub(crate) sender: S,
pub(crate) dispatcher: Arc<PipeDispatcher<P>>,
}
impl<S, P> PipeRequest<S, P>
where
S: PipeSender,
P: tokio::io::AsyncRead + Send + Unpin + 'static,
{
pub fn id(&self) -> u32 {
self.pipe_id
}
pub fn description(&self) -> &str {
&self.description
}
pub async fn accept(self) -> Result<PipeReader<P>, PipeError> {
let (pipe_tx, pipe_rx) = tokio::sync::oneshot::channel();
self.dispatcher
.pending_pipes
.lock()
.await
.insert(self.pipe_id, pipe_tx);
let response = CommunicationValue::new_with_type_map(
CommunicationType::PipeResponse,
&self.dispatcher.type_map,
)
.with_id(self.pipe_id)
.add_typed_default(DataType::Accepted, DataValue::BoolTrue);
if let Err(error) = self.sender.send_pipe_message(&response).await {
self.dispatcher
.pending_pipes
.lock()
.await
.remove(&self.pipe_id);
return Err(PipeError::from(error));
}
match tokio::time::timeout(self.dispatcher.policy.read_timeout, pipe_rx).await {
Ok(Ok(reader)) => Ok(reader),
Ok(Err(_)) => {
self.dispatcher
.pending_pipes
.lock()
.await
.remove(&self.pipe_id);
Err(PipeError::StreamClosed)
}
Err(_) => {
self.dispatcher
.pending_pipes
.lock()
.await
.remove(&self.pipe_id);
Err(PipeError::HandshakeTimeout)
}
}
}
pub async fn deny(self) -> Result<(), PipeError> {
let response = CommunicationValue::new_with_type_map(
CommunicationType::PipeResponse,
&self.dispatcher.type_map,
)
.with_id(self.pipe_id)
.add_typed_default(DataType::Accepted, DataValue::BoolFalse);
self.sender
.send_pipe_message(&response)
.await
.map_err(PipeError::from)
}
}
pub(crate) struct PipeDispatcher<P> {
pub(crate) pending_creations: StdMutex<HashMap<u32, PendingCreation>>,
pub(crate) expired_creations: StdMutex<HashMap<u32, tokio::time::Instant>>,
pub(crate) pending_pipes: Mutex<HashMap<u32, tokio::sync::oneshot::Sender<PipeReader<P>>>>,
pub(crate) policy: Arc<Policy>,
pub(crate) type_map: TypeMap,
}
pub(crate) struct PendingCreation {
pub(crate) token: Arc<()>,
pub(crate) sender: tokio::sync::oneshot::Sender<Result<bool, PipeError>>,
}
pub(crate) struct PendingCreationGuard<P> {
dispatcher: Arc<PipeDispatcher<P>>,
pipe_id: u32,
token: Arc<()>,
armed: bool,
}
impl<P> PendingCreationGuard<P> {
pub(crate) fn new(dispatcher: Arc<PipeDispatcher<P>>, pipe_id: u32, token: Arc<()>) -> Self {
Self {
dispatcher,
pipe_id,
token,
armed: true,
}
}
pub(crate) fn disarm(&mut self) {
self.armed = false;
}
}
impl<P> Drop for PendingCreationGuard<P> {
fn drop(&mut self) {
if self.armed {
expire_pending_creation(&self.dispatcher, self.pipe_id, &self.token);
}
}
}
const EXPIRED_CREATION_TOMBSTONE_TTL: tokio::time::Duration = tokio::time::Duration::from_secs(60);
const MAX_EXPIRED_CREATION_TOMBSTONES: usize = 1024;
pub(crate) fn expire_pending_creation<P>(
dispatcher: &PipeDispatcher<P>,
pipe_id: u32,
token: &Arc<()>,
) {
let removed = dispatcher
.pending_creations
.lock()
.ok()
.and_then(|mut pending| {
if pending
.get(&pipe_id)
.is_some_and(|entry| Arc::ptr_eq(&entry.token, token))
{
pending.remove(&pipe_id);
Some(())
} else {
None
}
});
if removed.is_none() {
return;
}
let Ok(mut expired) = dispatcher.expired_creations.lock() else {
return;
};
let now = tokio::time::Instant::now();
expired.retain(|_, expires_at| *expires_at > now);
if expired.len() >= MAX_EXPIRED_CREATION_TOMBSTONES
&& let Some(oldest) = expired
.iter()
.min_by_key(|(_, expires_at)| **expires_at)
.map(|(id, _)| *id)
{
expired.remove(&oldest);
}
expired.insert(pipe_id, now + EXPIRED_CREATION_TOMBSTONE_TTL);
}
fn consume_expired_creation<P>(dispatcher: &PipeDispatcher<P>, pipe_id: u32) -> bool {
let Ok(mut expired) = dispatcher.expired_creations.lock() else {
return false;
};
let now = tokio::time::Instant::now();
expired.retain(|_, expires_at| *expires_at > now);
expired.remove(&pipe_id).is_some()
}
pub(crate) fn is_expired_creation<P>(dispatcher: &PipeDispatcher<P>, pipe_id: u32) -> bool {
let Ok(mut expired) = dispatcher.expired_creations.lock() else {
return true;
};
let now = tokio::time::Instant::now();
expired.retain(|_, expires_at| *expires_at > now);
expired.contains_key(&pipe_id)
}
pub(crate) fn fail_pending_creations<P>(
dispatcher: &PipeDispatcher<P>,
error: &CommunicationError,
) {
let pending = dispatcher
.pending_creations
.lock()
.ok()
.map(|mut pending| std::mem::take(&mut *pending));
if let Some(pending) = pending {
let error = PipeError::from(error.clone());
for (_, pending) in pending {
let _ = pending.sender.send(Err(error.clone()));
}
}
if let Ok(mut expired) = dispatcher.expired_creations.lock() {
expired.clear();
}
}
pub(crate) async fn fail_pending_pipes<P>(dispatcher: &PipeDispatcher<P>) {
dispatcher.pending_pipes.lock().await.clear();
}
pub(crate) async fn run_dispatcher<S, R, P>(
receiver: R,
sender: S,
app_tx: mpsc::Sender<Result<CommunicationValue, CommunicationError>>,
pipe_req_tx: mpsc::Sender<PipeRequest<S, P>>,
dispatcher: Arc<PipeDispatcher<P>>,
) where
S: PipeSender,
R: PipeReceiver<P>,
P: tokio::io::AsyncRead + Send + Unpin + 'static,
{
loop {
match receiver.receive_pipe_event().await {
Ok(TransportEvent::Message(message)) => {
if message.is_type(CommunicationType::PipeRequest) {
let Some(pipe_id) = message.id().filter(|id| *id != 0) else {
let error = CommunicationError::Other(
"PipeRequest frame must contain a non-zero id".into(),
);
if app_tx.send(Err(error)).await.is_err() {
break;
}
continue;
};
let request = PipeRequest {
pipe_id,
description: message
.get_str(DataType::Description)
.unwrap_or("")
.to_owned(),
sender: sender.clone(),
dispatcher: dispatcher.clone(),
};
let _ = pipe_req_tx.send(request).await;
continue;
}
if message.is_type(CommunicationType::PipeResponse) {
let Some(pipe_id) = message.id().filter(|id| *id != 0) else {
let error = CommunicationError::Other(
"PipeResponse frame must contain a non-zero id".into(),
);
if app_tx.send(Err(error)).await.is_err() {
break;
}
continue;
};
let pending = dispatcher
.pending_creations
.lock()
.ok()
.and_then(|mut pending| pending.remove(&pipe_id));
if let Some(entry) = pending {
let _ = entry
.sender
.send(Ok(message.get_bool(DataType::Accepted).unwrap_or(false)));
} else if consume_expired_creation(&dispatcher, pipe_id) {
tracing::debug!(pipe_id, "ignored late pipe creation response");
}
continue;
}
if !matches!(message.id(), Some(id) if id != 0)
&& message
.get_type_name()
.is_some_and(|name| name.ends_with("Response"))
{
let error = CommunicationError::Other(
"response frame must contain a non-zero id".into(),
);
if app_tx.send(Err(error)).await.is_err() {
break;
}
continue;
}
if app_tx.send(Ok(message)).await.is_err() {
break;
}
}
Ok(TransportEvent::Pipe(reader)) => {
let pipe_id = reader.pipe_id();
let mut pending = dispatcher.pending_pipes.lock().await;
if let Some(reply) = pending.remove(&pipe_id) {
let _ = reply.send(reader);
continue;
}
drop(pending);
let request = PipeRequest {
pipe_id,
description: reader.description().to_owned(),
sender: sender.clone(),
dispatcher: dispatcher.clone(),
};
let _ = pipe_req_tx.send(request).await;
}
Err(error) => {
fail_pending_creations(&dispatcher, &error);
fail_pending_pipes(&dispatcher).await;
if app_tx.send(Err(error)).await.is_err() {
break;
}
break;
}
}
}
}