autocommit 2022-01-02 16:30:30 CET

src/client/mod.rs

@@ -0,0 +1,395 @@
+use crate::async_engine::{AsyncError, AsyncFd, SpawnedFuture};
+use crate::client::objects::Objects;
+use crate::ifs::wl_callback::WlCallback;
+use crate::ifs::wl_compositor::{WlCompositorError, WlCompositorObj};
+use crate::ifs::wl_display::{WlDisplay, WlDisplayError};
+use crate::ifs::wl_region::{WlRegion, WlRegionError};
+use crate::ifs::wl_registry::{WlRegistry, WlRegistryError};
+use crate::ifs::wl_shm::{WlShmError, WlShmObj};
+use crate::ifs::wl_shm_pool::{WlShmPool, WlShmPoolError};
+use crate::ifs::wl_subcompositor::WlSubcompositorObj;
+use crate::ifs::wl_surface::{WlSurface, WlSurfaceError};
+use crate::ifs::xdg_wm_base::XdgWmBaseObj;
+use crate::object::{Object, ObjectId, WL_DISPLAY_ID};
+use crate::state::State;
+use crate::utils::buffd::{BufFdError, WlFormatter, WlParser, WlParserError};
+use crate::utils::copyhashmap::CopyHashMap;
+use crate::utils::numcell::NumCell;
+use crate::utils::oneshot::{oneshot, OneshotTx};
+use crate::utils::queue::AsyncQueue;
+use ahash::AHashMap;
+use anyhow::anyhow;
+use std::cell::{Cell, RefMut};
+use std::fmt::{Debug, Display, Formatter};
+use std::future::Future;
+use std::rc::Rc;
+use thiserror::Error;
+use uapi::OwnedFd;
+
+mod objects;
+mod tasks;
+
+#[derive(Debug, Error)]
+pub enum ClientError {
+    #[error("An error occurred in the async engine")]
+    Async(#[from] AsyncError),
+    #[error("An error occurred reading from/writing to the client")]
+    Io(#[from] BufFdError),
+    #[error("An error occurred while processing a request")]
+    RequestError(#[source] Box<ClientError>),
+    #[error("Client tried to invoke a non-existent method")]
+    InvalidMethod,
+    #[error("Client tried to access non-existent object {0}")]
+    InvalidObject(ObjectId),
+    #[error("The message size is < 8")]
+    MessageSizeTooSmall,
+    #[error("The size of the message is not a multiple of 4")]
+    UnalignedMessage,
+    #[error("The outgoing buffer overflowed")]
+    OutBufferOverflow,
+    #[error("The requested client {0} does not exist")]
+    ClientDoesNotExist(ClientId),
+    #[error("There is no region with id {0}")]
+    RegionDoesNotExist(ObjectId),
+    #[error("Cannot parse the message")]
+    ParserError(#[source] Box<WlParserError>),
+    #[error("Server tried to allocate more than 0x1_00_00_00 ids")]
+    TooManyIds,
+    #[error("The server object id is out of bounds")]
+    ServerIdOutOfBounds,
+    #[error("The object id is unknown")]
+    UnknownId,
+    #[error("The id is already in use")]
+    IdAlreadyInUse,
+    #[error("The client object id is out of bounds")]
+    ClientIdOutOfBounds,
+    #[error("An error occurred in a `wl_display`")]
+    WlDisplayError(#[source] Box<WlDisplayError>),
+    #[error("An error occurred in a `wl_registry`")]
+    WlRegistryError(#[source] Box<WlRegistryError>),
+    #[error("Could not add object {0} to the client")]
+    AddObjectError(ObjectId, #[source] Box<ClientError>),
+    #[error("An error occurred in a `wl_surface`")]
+    WlSurfaceError(#[source] Box<WlSurfaceError>),
+    #[error("An error occurred in a `wl_compositor`")]
+    WlCompositorError(#[source] Box<WlCompositorError>),
+    #[error("An error occurred in a `wl_shm`")]
+    WlShmError(#[source] Box<WlShmError>),
+    #[error("An error occurred in a `wl_shm_pool`")]
+    WlShmPoolError(#[source] Box<WlShmPoolError>),
+    #[error("An error occurred in a `wl_region`")]
+    WlRegionError(#[source] Box<WlRegionError>),
+    #[error("Object {0} is not a display")]
+    NotADisplay(ObjectId),
+}
+
+efrom!(ClientError, ParserError, WlParserError);
+efrom!(ClientError, WlDisplayError, WlDisplayError);
+efrom!(ClientError, WlRegistryError, WlRegistryError);
+efrom!(ClientError, WlSurfaceError, WlSurfaceError);
+efrom!(ClientError, WlCompositorError, WlCompositorError);
+efrom!(ClientError, WlShmError, WlShmError);
+efrom!(ClientError, WlShmPoolError, WlShmPoolError);
+efrom!(ClientError, WlRegionError, WlRegionError);
+
+impl ClientError {
+    fn peer_closed(&self) -> bool {
+        match self {
+            ClientError::Io(BufFdError::Closed) => true,
+            _ => false,
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone, Hash, Ord, PartialOrd, Eq, PartialEq)]
+pub struct ClientId(u64);
+
+impl Display for ClientId {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        Display::fmt(&self.0, f)
+    }
+}
+
+pub struct Clients {
+    next_client_id: NumCell<u64>,
+    clients: CopyHashMap<ClientId, Rc<ClientHolder>>,
+    shutdown_clients: CopyHashMap<ClientId, Rc<ClientHolder>>,
+}
+
+impl Clients {
+    pub fn new() -> Self {
+        Self {
+            next_client_id: NumCell::new(1),
+            clients: CopyHashMap::new(),
+            shutdown_clients: CopyHashMap::new(),
+        }
+    }
+
+    pub fn id(&self) -> ClientId {
+        ClientId(self.next_client_id.fetch_add(1))
+    }
+
+    pub fn get(&self, id: ClientId) -> Result<Rc<Client>, ClientError> {
+        match self.clients.get(&id) {
+            Some(c) => Ok(c.data.clone()),
+            _ => Err(ClientError::ClientDoesNotExist(id)),
+        }
+    }
+
+    pub fn spawn(
+        &self,
+        id: ClientId,
+        global: &Rc<State>,
+        socket: OwnedFd,
+    ) -> Result<(), ClientError> {
+        let (send, recv) = oneshot();
+        let data = Rc::new(Client {
+            id,
+            state: global.clone(),
+            socket: global.eng.fd(&Rc::new(socket))?,
+            objects: Objects::new(),
+            events: AsyncQueue::new(),
+            shutdown: Cell::new(Some(send)),
+            shutdown_sent: Cell::new(false),
+        });
+        data.objects
+            .add_client_object(Rc::new(WlDisplay::new(&data)))
+            .expect("");
+        let client = Rc::new(ClientHolder {
+            _handler: global.eng.spawn(tasks::client(data.clone(), recv)),
+            data,
+        });
+        self.clients.set(client.data.id, client.clone());
+        log::info!("Client {} connected", id);
+        Ok(())
+    }
+
+    pub fn kill(&self, client: ClientId) {
+        log::info!("Removing client {}", client.0);
+        if self.clients.remove(&client).is_none() {
+            self.shutdown_clients.remove(&client);
+        }
+    }
+
+    pub fn shutdown(&self, client_id: ClientId) {
+        if let Some(client) = self.clients.remove(&client_id) {
+            log::info!("Shutting down client {}", client.data.id.0);
+            client.data.shutdown.replace(None).unwrap().send(());
+            client.data.events.push(WlEvent::Shutdown);
+            client.data.shutdown_sent.set(true);
+            self.shutdown_clients.set(client_id, client);
+        }
+    }
+
+    pub fn broadcast<B>(&self, mut f: B)
+    where
+        B: FnMut(&Rc<Client>),
+    {
+        let clients = self.clients.lock();
+        for client in clients.values() {
+            f(&client.data);
+        }
+    }
+}
+
+struct ClientHolder {
+    data: Rc<Client>,
+    _handler: SpawnedFuture<()>,
+}
+
+impl Drop for ClientHolder {
+    fn drop(&mut self) {
+        self.data.objects.destroy();
+    }
+}
+
+pub trait EventFormatter: Debug {
+    fn format(self: Box<Self>, fmt: &mut WlFormatter<'_>);
+    fn obj(&self) -> &dyn Object;
+}
+
+pub type DynEventFormatter = Box<dyn EventFormatter>;
+
+pub trait RequestParser<'a>: Debug + Sized {
+    fn parse(parser: &mut WlParser<'_, 'a>) -> Result<Self, WlParserError>;
+}
+
+enum WlEvent {
+    Flush,
+    Shutdown,
+    Event(Box<dyn EventFormatter>),
+}
+
+pub struct Client {
+    pub id: ClientId,
+    pub state: Rc<State>,
+    socket: AsyncFd,
+    objects: Objects,
+    events: AsyncQueue<WlEvent>,
+    shutdown: Cell<Option<OneshotTx<()>>>,
+    shutdown_sent: Cell<bool>,
+}
+
+const MAX_PENDING_EVENTS: usize = 100;
+
+impl Client {
+    pub fn invalid_request(&self, obj: &dyn Object, request: u32) {
+        log::error!(
+            "Client {} sent an invalid request {} on object {} of type {}",
+            self.id.0,
+            request,
+            obj.id(),
+            obj.interface().name(),
+        );
+        match self.display() {
+            Ok(d) => self.fatal_event(d.invalid_request(obj, request)),
+            Err(e) => {
+                log::error!(
+                    "Could not retrieve display of client {}: {:#}",
+                    self.id,
+                    anyhow!(e)
+                );
+                self.state.clients.kill(self.id);
+            }
+        }
+    }
+
+    pub fn display(&self) -> Result<Rc<WlDisplay>, ClientError> {
+        Ok(self.objects.get_obj(WL_DISPLAY_ID)?.into_display()?)
+    }
+
+    pub fn parse<'a, R: RequestParser<'a>>(
+        &self,
+        obj: &impl Object,
+        mut parser: WlParser<'_, 'a>,
+    ) -> Result<R, WlParserError> {
+        let res = R::parse(&mut parser)?;
+        parser.eof()?;
+        log::trace!(
+            "Client {} -> {}@{}.{:?}",
+            self.id,
+            obj.interface().name(),
+            obj.id(),
+            res
+        );
+        Ok(res)
+    }
+
+    pub fn fatal_event(&self, event: Box<dyn EventFormatter>) {
+        self.events.push(WlEvent::Event(event));
+        self.state.clients.shutdown(self.id);
+    }
+
+    pub fn event_locked(&self, event: Box<dyn EventFormatter>) -> bool {
+        self.events.push(WlEvent::Event(event));
+        self.events.size() > MAX_PENDING_EVENTS
+    }
+
+    pub async fn event(&self, event: Box<dyn EventFormatter>) -> Result<(), ClientError> {
+        self.event2(WlEvent::Event(event)).await
+    }
+
+    async fn event2(&self, event: WlEvent) -> Result<(), ClientError> {
+        self.events.push(event);
+        self.check_queue_size().await
+    }
+
+    pub async fn check_queue_size(&self) -> Result<(), ClientError> {
+        if self.events.size() > MAX_PENDING_EVENTS {
+            self.state.eng.yield_now().await;
+            if self.events.size() > MAX_PENDING_EVENTS {
+                log::error!("Client {} is too slow at fetching events", self.id.0);
+                self.state.clients.kill(self.id);
+                return Err(ClientError::OutBufferOverflow);
+            }
+        }
+        Ok(())
+    }
+
+    pub fn get_region(&self, id: ObjectId) -> Result<Rc<WlRegion>, ClientError> {
+        match self.objects.regions.get(&id) {
+            Some(r) => Ok(r),
+            _ => Err(ClientError::RegionDoesNotExist(id)),
+        }
+    }
+
+    fn simple_add_obj<T: Object>(&self, obj: &Rc<T>, client: bool) -> Result<(), ClientError> {
+        if client {
+            self.objects.add_client_object(obj.clone())
+        } else {
+            self.objects.add_server_object(obj.clone());
+            Ok(())
+        }
+    }
+
+    fn simple_remove_obj<'a>(
+        &'a self,
+        id: ObjectId,
+    ) -> impl Future<Output = Result<(), ClientError>> + 'a {
+        self.objects.remove_obj(self, id)
+    }
+
+    pub fn lock_registries(&self) -> RefMut<AHashMap<ObjectId, Rc<WlRegistry>>> {
+        self.objects.registries()
+    }
+}
+
+pub trait AddObj<T> {
+    type RemoveObj<'a>: Future<Output = Result<(), ClientError>> + 'a;
+
+    fn add_client_obj(&self, obj: &Rc<T>) -> Result<(), ClientError> {
+        self.add_obj(obj, true)
+    }
+
+    fn add_server_obj(&self, obj: &Rc<T>) {
+        self.add_obj(obj, false).expect("add_server_obj failed")
+    }
+
+    fn add_obj(&self, obj: &Rc<T>, client: bool) -> Result<(), ClientError>;
+
+    fn remove_obj<'a>(&'a self, obj: &'a T) -> Self::RemoveObj<'a>;
+}
+
+macro_rules! simple_add_obj {
+    ($ty:ty) => {
+        impl AddObj<$ty> for Client {
+            type RemoveObj<'a> = impl Future<Output = Result<(), ClientError>> + 'a;
+
+            fn add_obj(&self, obj: &Rc<$ty>, client: bool) -> Result<(), ClientError> {
+                self.simple_add_obj(obj, client)
+            }
+            fn remove_obj<'a>(&'a self, obj: &'a $ty) -> Self::RemoveObj<'a> {
+                self.simple_remove_obj(obj.id())
+            }
+        }
+    };
+}
+
+simple_add_obj!(WlCompositorObj);
+simple_add_obj!(WlCallback);
+simple_add_obj!(WlRegistry);
+simple_add_obj!(WlShmObj);
+simple_add_obj!(WlShmPool);
+simple_add_obj!(WlSubcompositorObj);
+simple_add_obj!(XdgWmBaseObj);
+
+macro_rules! dedicated_add_obj {
+    ($ty:ty, $field:ident) => {
+        impl AddObj<$ty> for Client {
+            type RemoveObj<'a> = impl Future<Output = Result<(), ClientError>> + 'a;
+
+            fn add_obj(&self, obj: &Rc<$ty>, client: bool) -> Result<(), ClientError> {
+                self.simple_add_obj(obj, client)?;
+                self.objects.$field.set(obj.id(), obj.clone());
+                Ok(())
+            }
+            fn remove_obj<'a>(&'a self, obj: &'a $ty) -> Self::RemoveObj<'a> {
+                self.objects.$field.remove(&obj.id());
+                self.simple_remove_obj(obj.id())
+            }
+        }
+    };
+}
+
+dedicated_add_obj!(WlRegion, regions);
+dedicated_add_obj!(WlSurface, surfaces);

src/client/objects.rs

@@ -0,0 +1,122 @@
+use crate::client::{Client, ClientError};
+use crate::ifs::wl_region::WlRegion;
+use crate::ifs::wl_registry::WlRegistry;
+use crate::ifs::wl_surface::WlSurface;
+use crate::object::{Object, ObjectId};
+use crate::utils::copyhashmap::CopyHashMap;
+use ahash::AHashMap;
+use std::cell::{RefCell, RefMut};
+use std::mem;
+use std::rc::Rc;
+
+pub struct Objects {
+    registry: CopyHashMap<ObjectId, Rc<dyn Object>>,
+    registries: CopyHashMap<ObjectId, Rc<WlRegistry>>,
+    pub surfaces: CopyHashMap<ObjectId, Rc<WlSurface>>,
+    pub regions: CopyHashMap<ObjectId, Rc<WlRegion>>,
+    ids: RefCell<Vec<usize>>,
+}
+
+pub const MIN_SERVER_ID: u32 = 0xff000000;
+const SEG_SIZE: usize = 8 * mem::size_of::<usize>();
+
+impl Objects {
+    pub fn new() -> Self {
+        Self {
+            registry: Default::default(),
+            registries: Default::default(),
+            surfaces: Default::default(),
+            regions: Default::default(),
+            ids: RefCell::new(vec![]),
+        }
+    }
+
+    pub fn destroy(&self) {
+        self.registry.clear();
+        self.registries.clear();
+        self.surfaces.clear();
+    }
+
+    fn id(&self, client_data: &Client) -> Result<ObjectId, ClientError> {
+        const MAX_ID_OFFSET: u32 = u32::MAX - MIN_SERVER_ID;
+        let offset = self.id_offset();
+        if offset > MAX_ID_OFFSET {
+            log::error!(
+                "Client {} caused the server to allocate more than 0x{:x} ids",
+                client_data.id,
+                MAX_ID_OFFSET + 1
+            );
+            return Err(ClientError::TooManyIds);
+        }
+        Ok(ObjectId::from_raw(MIN_SERVER_ID + offset))
+    }
+
+    pub fn get_obj(&self, id: ObjectId) -> Result<Rc<dyn Object>, ClientError> {
+        match self.registry.get(&id) {
+            Some(o) => Ok(o),
+            _ => Err(ClientError::UnknownId),
+        }
+    }
+
+    pub fn add_server_object(&self, obj: Rc<dyn Object>) {
+        let id = obj.id();
+        assert!(id.raw() >= MIN_SERVER_ID);
+        assert!(!self.registry.contains(&id));
+        self.registry.set(id, obj.clone());
+    }
+
+    pub fn add_client_object(&self, obj: Rc<dyn Object>) -> Result<(), ClientError> {
+        let id = obj.id();
+        let res = (|| {
+            if id.raw() == 0 || id.raw() >= MIN_SERVER_ID {
+                return Err(ClientError::ClientIdOutOfBounds);
+            }
+            if self.registry.contains(&id) {
+                return Err(ClientError::IdAlreadyInUse);
+            }
+            self.registry.set(id, obj.clone());
+            Ok(())
+        })();
+        if let Err(e) = res {
+            return Err(ClientError::AddObjectError(id, Box::new(e)));
+        }
+        Ok(())
+    }
+
+    pub async fn remove_obj(&self, client_data: &Client, id: ObjectId) -> Result<(), ClientError> {
+        if self.registry.remove(&id).is_none() {
+            return Err(ClientError::UnknownId);
+        }
+        if id.raw() >= MIN_SERVER_ID {
+            let offset = (id.raw() - MIN_SERVER_ID) as usize;
+            let pos = offset / SEG_SIZE;
+            let seg_offset = offset % SEG_SIZE;
+            let mut ids = self.ids.borrow_mut();
+            if ids.len() <= pos {
+                return Err(ClientError::ServerIdOutOfBounds);
+            }
+            ids[pos] |= 1 << seg_offset;
+        }
+        client_data
+            .event(client_data.display()?.delete_id(id))
+            .await?;
+        Ok(())
+    }
+
+    pub fn registries(&self) -> RefMut<AHashMap<ObjectId, Rc<WlRegistry>>> {
+        self.registries.lock()
+    }
+
+    fn id_offset(&self) -> u32 {
+        let mut ids = self.ids.borrow_mut();
+        for (pos, seg) in ids.iter_mut().enumerate() {
+            if *seg != 0 {
+                let offset = seg.trailing_zeros();
+                *seg &= !(1 << offset);
+                return (pos * SEG_SIZE) as u32 + offset;
+            }
+        }
+        ids.push(!1);
+        ((ids.len() - 1) * SEG_SIZE) as u32
+    }
+}

src/client/tasks.rs

@@ -0,0 +1,154 @@
+use crate::client::{Client, ClientError, WlEvent};
+use crate::object::ObjectId;
+use crate::utils::buffd::{BufFdIn, BufFdOut, WlFormatter, WlParser};
+use crate::utils::oneshot::OneshotRx;
+use crate::utils::vec_ext::VecExt;
+use anyhow::anyhow;
+use futures::{select, FutureExt};
+use std::mem;
+use std::rc::Rc;
+
+pub async fn client(data: Rc<Client>, shutdown: OneshotRx<()>) {
+    let mut recv = data.state.eng.spawn(receive(data.clone())).fuse();
+    let _send = data.state.eng.spawn(send(data.clone()));
+    select! {
+        _ = recv => { },
+        _ = shutdown.fuse() => { },
+    }
+    drop(recv);
+    if !data.shutdown_sent.get() {
+        data.events.push(WlEvent::Shutdown);
+    }
+    match data.state.eng.timeout(5000) {
+        Ok(timeout) => {
+            timeout.await;
+            log::error!("Could not shut down client {} within 5 seconds", data.id.0);
+        }
+        Err(e) => {
+            log::error!("Could not create a timeout: {:#}", e);
+        }
+    }
+    data.state.clients.kill(data.id);
+}
+
+async fn receive(data: Rc<Client>) {
+    let display = data.display().unwrap();
+    let recv = async {
+        let mut buf = BufFdIn::new(data.socket.clone());
+        let mut data_buf = Vec::<u32>::new();
+        loop {
+            let mut hdr = [0u32, 0];
+            buf.read_full(&mut hdr[..]).await?;
+            let obj_id = ObjectId::from_raw(hdr[0]);
+            let len = (hdr[1] >> 16) as usize;
+            let request = hdr[1] & 0xffff;
+            let obj = match data.objects.get_obj(obj_id) {
+                Ok(obj) => obj,
+                _ => {
+                    data.fatal_event(display.invalid_object(obj_id));
+                    return Err(ClientError::InvalidObject(obj_id));
+                }
+            };
+            // log::trace!("obj: {}, request: {}, len: {}", obj_id, request, len);
+            if request >= obj.num_requests() {
+                data.invalid_request(&*obj, request);
+                return Err(ClientError::InvalidMethod);
+            }
+            if len < 8 {
+                return Err(ClientError::MessageSizeTooSmall);
+            }
+            if len % 4 != 0 {
+                return Err(ClientError::UnalignedMessage);
+            }
+            let len = len / 4 - 2;
+            data_buf.clear();
+            data_buf.reserve(len);
+            let unused = data_buf.split_at_spare_mut_ext().1;
+            buf.read_full(&mut unused[..len]).await?;
+            unsafe {
+                data_buf.set_len(len);
+            }
+            // log::trace!("{:x?}", data_buf);
+            let parser = WlParser::new(&mut buf, &data_buf[..]);
+            if let Err(e) = obj.handle_request(request, parser).await {
+                return Err(ClientError::RequestError(Box::new(e)));
+            }
+            data.event2(WlEvent::Flush).await?;
+        }
+    };
+    let res: Result<(), ClientError> = recv.await;
+    if let Err(e) = res {
+        if e.peer_closed() {
+            log::info!("Client {} terminated the connection", data.id.0);
+            data.state.clients.kill(data.id);
+        } else {
+            let e = anyhow!(e);
+            log::error!(
+                "An error occurred while trying to handle a message from client {}: {:#}",
+                data.id.0,
+                e
+            );
+            if !data.shutdown_sent.get() {
+                data.fatal_event(display.implementation_error(format!("{:#}", e)));
+            }
+        }
+    }
+}
+
+async fn send(data: Rc<Client>) {
+    let send = async {
+        let mut buf = BufFdOut::new(data.socket.clone());
+        let mut flush_requested = false;
+        loop {
+            let mut event = data.events.pop().await;
+            loop {
+                match event {
+                    WlEvent::Flush => {
+                        flush_requested = true;
+                    }
+                    WlEvent::Shutdown => {
+                        buf.flush().await?;
+                        return Ok(());
+                    }
+                    WlEvent::Event(e) => {
+                        if log::log_enabled!(log::Level::Trace) {
+                            let obj = e.obj();
+                            log::trace!(
+                                "Client {} <= {}@{}.{:?}",
+                                data.id,
+                                obj.interface().name(),
+                                obj.id(),
+                                e
+                            );
+                        }
+                        e.format(&mut WlFormatter::new(&mut buf));
+                        if buf.needs_flush() {
+                            buf.flush().await?;
+                            flush_requested = false;
+                        }
+                    }
+                }
+                event = match data.events.try_pop() {
+                    Some(e) => e,
+                    _ => break,
+                };
+            }
+            if mem::take(&mut flush_requested) {
+                buf.flush().await?;
+            }
+        }
+    };
+    let res: Result<(), ClientError> = send.await;
+    if let Err(e) = res {
+        if e.peer_closed() {
+            log::info!("Client {} terminated the connection", data.id.0);
+        } else {
+            log::error!(
+                "An error occurred while sending data to client {}: {:#}",
+                data.id.0,
+                e
+            );
+        }
+    }
+    data.state.clients.kill(data.id);
+}