vfs/directory/mutable/
connection.rs

1// Copyright 2019 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Connection to a directory that can be modified by the client though a FIDL connection.
6
7use crate::common::{
8    decode_extended_attribute_value, encode_extended_attribute_value, extended_attributes_sender,
9    io1_to_io2_attrs,
10};
11use crate::directory::connection::{BaseConnection, ConnectionState};
12use crate::directory::entry_container::MutableDirectory;
13use crate::execution_scope::ExecutionScope;
14use crate::name::validate_name;
15use crate::node::OpenNode;
16use crate::object_request::ConnectionCreator;
17use crate::path::Path;
18use crate::request_handler::{RequestHandler, RequestListener};
19use crate::token_registry::{TokenInterface, TokenRegistry, Tokenizable};
20use crate::{ObjectRequestRef, ProtocolsExt};
21
22use anyhow::Error;
23use fidl::endpoints::ServerEnd;
24use fidl::Handle;
25use fidl_fuchsia_io as fio;
26use std::ops::ControlFlow;
27use std::pin::Pin;
28use std::sync::Arc;
29use storage_trace::{self as trace, TraceFutureExt};
30use zx_status::Status;
31
32pub struct MutableConnection<DirectoryType: MutableDirectory> {
33    base: BaseConnection<DirectoryType>,
34}
35
36impl<DirectoryType: MutableDirectory> MutableConnection<DirectoryType> {
37    /// Creates a new connection to serve the mutable directory. The directory will be served from a
38    /// new async `Task`, not from the current `Task`. Errors in constructing the connection are not
39    /// guaranteed to be returned, they may be sent directly to the client end of the connection.
40    /// This method should be called from within an `ObjectRequest` handler to ensure that errors
41    /// are sent to the client end of the connection.
42    pub async fn create(
43        scope: ExecutionScope,
44        directory: Arc<DirectoryType>,
45        protocols: impl ProtocolsExt,
46        object_request: ObjectRequestRef<'_>,
47    ) -> Result<(), Status> {
48        // Ensure we close the directory if we fail to prepare the connection.
49        let directory = OpenNode::new(directory);
50
51        let connection = MutableConnection {
52            base: BaseConnection::new(scope.clone(), directory, protocols.to_directory_options()?),
53        };
54
55        if let Ok(requests) = object_request.take().into_request_stream(&connection.base).await {
56            scope.spawn(RequestListener::new(requests, Tokenizable::new(connection)));
57        }
58        Ok(())
59    }
60
61    async fn handle_request(
62        this: Pin<&mut Tokenizable<Self>>,
63        request: fio::DirectoryRequest,
64    ) -> Result<ConnectionState, Error> {
65        match request {
66            fio::DirectoryRequest::Unlink { name, options, responder } => {
67                let result = this.handle_unlink(name, options).await;
68                responder.send(result.map_err(Status::into_raw))?;
69            }
70            fio::DirectoryRequest::GetToken { responder } => {
71                let (status, token) = match Self::handle_get_token(this.into_ref()) {
72                    Ok(token) => (Status::OK, Some(token)),
73                    Err(status) => (status, None),
74                };
75                responder.send(status.into_raw(), token)?;
76            }
77            fio::DirectoryRequest::Rename { src, dst_parent_token, dst, responder } => {
78                let result = this.handle_rename(src, Handle::from(dst_parent_token), dst).await;
79                responder.send(result.map_err(Status::into_raw))?;
80            }
81            fio::DirectoryRequest::SetAttr { flags, attributes, responder } => {
82                let status = match this
83                    .handle_update_attributes(io1_to_io2_attrs(flags, attributes))
84                    .await
85                {
86                    Ok(()) => Status::OK,
87                    Err(status) => status,
88                };
89                responder.send(status.into_raw())?;
90            }
91            fio::DirectoryRequest::Sync { responder } => {
92                responder.send(this.base.directory.sync().await.map_err(Status::into_raw))?;
93            }
94            fio::DirectoryRequest::CreateSymlink {
95                responder, name, target, connection, ..
96            } => {
97                if !this.base.options.rights.contains(fio::Operations::MODIFY_DIRECTORY) {
98                    responder.send(Err(Status::ACCESS_DENIED.into_raw()))?;
99                } else if validate_name(&name).is_err() {
100                    responder.send(Err(Status::INVALID_ARGS.into_raw()))?;
101                } else {
102                    responder.send(
103                        this.base
104                            .directory
105                            .create_symlink(name, target, connection)
106                            .await
107                            .map_err(Status::into_raw),
108                    )?;
109                }
110            }
111            fio::DirectoryRequest::ListExtendedAttributes { iterator, control_handle: _ } => {
112                this.handle_list_extended_attribute(iterator)
113                    .trace(trace::trace_future_args!(
114                        c"storage",
115                        c"Directory::ListExtendedAttributes"
116                    ))
117                    .await;
118            }
119            fio::DirectoryRequest::GetExtendedAttribute { name, responder } => {
120                async move {
121                    let res =
122                        this.handle_get_extended_attribute(name).await.map_err(Status::into_raw);
123                    responder.send(res)
124                }
125                .trace(trace::trace_future_args!(c"storage", c"Directory::GetExtendedAttribute"))
126                .await?;
127            }
128            fio::DirectoryRequest::SetExtendedAttribute { name, value, mode, responder } => {
129                async move {
130                    let res = this
131                        .handle_set_extended_attribute(name, value, mode)
132                        .await
133                        .map_err(Status::into_raw);
134                    responder.send(res)
135                }
136                .trace(trace::trace_future_args!(c"storage", c"Directory::SetExtendedAttribute"))
137                .await?;
138            }
139            fio::DirectoryRequest::RemoveExtendedAttribute { name, responder } => {
140                async move {
141                    let res =
142                        this.handle_remove_extended_attribute(name).await.map_err(Status::into_raw);
143                    responder.send(res)
144                }
145                .trace(trace::trace_future_args!(c"storage", c"Directory::RemoveExtendedAttribute"))
146                .await?;
147            }
148            fio::DirectoryRequest::UpdateAttributes { payload, responder } => {
149                async move {
150                    responder.send(
151                        this.handle_update_attributes(payload).await.map_err(Status::into_raw),
152                    )
153                }
154                .trace(trace::trace_future_args!(c"storage", c"Directory::UpdateAttributes"))
155                .await?;
156            }
157            request => {
158                return this.as_mut().base.handle_request(request).await;
159            }
160        }
161        Ok(ConnectionState::Alive)
162    }
163
164    async fn handle_update_attributes(
165        &self,
166        attributes: fio::MutableNodeAttributes,
167    ) -> Result<(), Status> {
168        if !self.base.options.rights.contains(fio::Operations::UPDATE_ATTRIBUTES) {
169            return Err(Status::BAD_HANDLE);
170        }
171        // TODO(jfsulliv): Consider always permitting attributes to be deferrable. The risk with
172        // this is that filesystems would require a background flush of dirty attributes to disk.
173        self.base.directory.update_attributes(attributes).await
174    }
175
176    async fn handle_unlink(&self, name: String, options: fio::UnlinkOptions) -> Result<(), Status> {
177        if !self.base.options.rights.contains(fio::Rights::MODIFY_DIRECTORY) {
178            return Err(Status::BAD_HANDLE);
179        }
180
181        if name.is_empty() || name.contains('/') || name == "." || name == ".." {
182            return Err(Status::INVALID_ARGS);
183        }
184
185        self.base
186            .directory
187            .clone()
188            .unlink(
189                &name,
190                options
191                    .flags
192                    .map(|f| f.contains(fio::UnlinkFlags::MUST_BE_DIRECTORY))
193                    .unwrap_or(false),
194            )
195            .await
196    }
197
198    fn handle_get_token(this: Pin<&Tokenizable<Self>>) -> Result<Handle, Status> {
199        // GetToken exists to support linking, so we must make sure the connection has the
200        // permission to modify the directory.
201        if !this.base.options.rights.contains(fio::Rights::MODIFY_DIRECTORY) {
202            return Err(Status::BAD_HANDLE);
203        }
204        Ok(TokenRegistry::get_token(this)?)
205    }
206
207    async fn handle_rename(
208        &self,
209        src: String,
210        dst_parent_token: Handle,
211        dst: String,
212    ) -> Result<(), Status> {
213        if !self.base.options.rights.contains(fio::Rights::MODIFY_DIRECTORY) {
214            return Err(Status::BAD_HANDLE);
215        }
216
217        let src = Path::validate_and_split(src)?;
218        let dst = Path::validate_and_split(dst)?;
219
220        if !src.is_single_component() || !dst.is_single_component() {
221            return Err(Status::INVALID_ARGS);
222        }
223
224        let dst_parent = match self.base.scope.token_registry().get_owner(dst_parent_token)? {
225            None => return Err(Status::NOT_FOUND),
226            Some(entry) => entry,
227        };
228
229        dst_parent.clone().rename(self.base.directory.clone(), src, dst).await
230    }
231
232    async fn handle_list_extended_attribute(
233        &self,
234        iterator: ServerEnd<fio::ExtendedAttributeIteratorMarker>,
235    ) {
236        let attributes = match self.base.directory.list_extended_attributes().await {
237            Ok(attributes) => attributes,
238            Err(status) => {
239                log::error!(status:?; "list extended attributes failed");
240                iterator
241                    .close_with_epitaph(status)
242                    .unwrap_or_else(|error| log::error!(error:?; "failed to send epitaph"));
243                return;
244            }
245        };
246        self.base.scope.spawn(extended_attributes_sender(iterator, attributes));
247    }
248
249    async fn handle_get_extended_attribute(
250        &self,
251        name: Vec<u8>,
252    ) -> Result<fio::ExtendedAttributeValue, Status> {
253        let value = self.base.directory.get_extended_attribute(name).await?;
254        encode_extended_attribute_value(value)
255    }
256
257    async fn handle_set_extended_attribute(
258        &self,
259        name: Vec<u8>,
260        value: fio::ExtendedAttributeValue,
261        mode: fio::SetExtendedAttributeMode,
262    ) -> Result<(), Status> {
263        if name.contains(&0) {
264            return Err(Status::INVALID_ARGS);
265        }
266        let val = decode_extended_attribute_value(value)?;
267        self.base.directory.set_extended_attribute(name, val, mode).await
268    }
269
270    async fn handle_remove_extended_attribute(&self, name: Vec<u8>) -> Result<(), Status> {
271        self.base.directory.remove_extended_attribute(name).await
272    }
273}
274
275impl<DirectoryType: MutableDirectory> ConnectionCreator<DirectoryType>
276    for MutableConnection<DirectoryType>
277{
278    async fn create<'a>(
279        scope: ExecutionScope,
280        node: Arc<DirectoryType>,
281        protocols: impl ProtocolsExt,
282        object_request: ObjectRequestRef<'a>,
283    ) -> Result<(), Status> {
284        Self::create(scope, node, protocols, object_request).await
285    }
286}
287
288impl<DirectoryType: MutableDirectory> RequestHandler
289    for Tokenizable<MutableConnection<DirectoryType>>
290{
291    type Request = Result<fio::DirectoryRequest, fidl::Error>;
292
293    async fn handle_request(self: Pin<&mut Self>, request: Self::Request) -> ControlFlow<()> {
294        let _guard = self.base.scope.active_guard();
295        match request {
296            Ok(request) => {
297                match MutableConnection::<DirectoryType>::handle_request(self, request).await {
298                    Ok(ConnectionState::Alive) => ControlFlow::Continue(()),
299                    Ok(ConnectionState::Closed) | Err(_) => ControlFlow::Break(()),
300                }
301            }
302            Err(_) => ControlFlow::Break(()),
303        }
304    }
305}
306
307impl<DirectoryType: MutableDirectory> TokenInterface for MutableConnection<DirectoryType> {
308    fn get_node(&self) -> Arc<dyn MutableDirectory> {
309        self.base.directory.clone()
310    }
311
312    fn token_registry(&self) -> &TokenRegistry {
313        self.base.scope.token_registry()
314    }
315}
316
317#[cfg(test)]
318mod tests {
319    use super::*;
320    use crate::directory::dirents_sink;
321    use crate::directory::entry::{EntryInfo, GetEntryInfo};
322    use crate::directory::entry_container::{Directory, DirectoryWatcher};
323    use crate::directory::traversal_position::TraversalPosition;
324    use crate::node::Node;
325    use crate::ToObjectRequest;
326    use futures::future::BoxFuture;
327    use std::any::Any;
328    use std::future::ready;
329    use std::sync::{Mutex, Weak};
330
331    #[derive(Debug, PartialEq)]
332    enum MutableDirectoryAction {
333        Link { id: u32, path: String },
334        Unlink { id: u32, name: String },
335        Rename { id: u32, src_name: String, dst_dir: u32, dst_name: String },
336        UpdateAttributes { id: u32, attributes: fio::MutableNodeAttributes },
337        Sync,
338        Close,
339    }
340
341    #[derive(Debug)]
342    struct MockDirectory {
343        id: u32,
344        fs: Arc<MockFilesystem>,
345    }
346
347    impl MockDirectory {
348        pub fn new(id: u32, fs: Arc<MockFilesystem>) -> Arc<Self> {
349            Arc::new(MockDirectory { id, fs })
350        }
351    }
352
353    impl PartialEq for MockDirectory {
354        fn eq(&self, other: &Self) -> bool {
355            self.id == other.id
356        }
357    }
358
359    impl GetEntryInfo for MockDirectory {
360        fn entry_info(&self) -> EntryInfo {
361            EntryInfo::new(0, fio::DirentType::Directory)
362        }
363    }
364
365    impl Node for MockDirectory {
366        async fn get_attributes(
367            &self,
368            _query: fio::NodeAttributesQuery,
369        ) -> Result<fio::NodeAttributes2, Status> {
370            unimplemented!("Not implemented");
371        }
372
373        fn close(self: Arc<Self>) {
374            let _ = self.fs.handle_event(MutableDirectoryAction::Close);
375        }
376    }
377
378    impl Directory for MockDirectory {
379        fn open(
380            self: Arc<Self>,
381            _scope: ExecutionScope,
382            _flags: fio::OpenFlags,
383            _path: Path,
384            _server_end: ServerEnd<fio::NodeMarker>,
385        ) {
386            unimplemented!("Not implemented!");
387        }
388
389        fn open3(
390            self: Arc<Self>,
391            _scope: ExecutionScope,
392            _path: Path,
393            _flags: fio::Flags,
394            _object_request: ObjectRequestRef<'_>,
395        ) -> Result<(), Status> {
396            unimplemented!("Not implemented!");
397        }
398
399        async fn read_dirents<'a>(
400            &'a self,
401            _pos: &'a TraversalPosition,
402            _sink: Box<dyn dirents_sink::Sink>,
403        ) -> Result<(TraversalPosition, Box<dyn dirents_sink::Sealed>), Status> {
404            unimplemented!("Not implemented");
405        }
406
407        fn register_watcher(
408            self: Arc<Self>,
409            _scope: ExecutionScope,
410            _mask: fio::WatchMask,
411            _watcher: DirectoryWatcher,
412        ) -> Result<(), Status> {
413            unimplemented!("Not implemented");
414        }
415
416        fn unregister_watcher(self: Arc<Self>, _key: usize) {
417            unimplemented!("Not implemented");
418        }
419    }
420
421    impl MutableDirectory for MockDirectory {
422        fn link<'a>(
423            self: Arc<Self>,
424            path: String,
425            _source_dir: Arc<dyn Any + Send + Sync>,
426            _source_name: &'a str,
427        ) -> BoxFuture<'a, Result<(), Status>> {
428            let result = self.fs.handle_event(MutableDirectoryAction::Link { id: self.id, path });
429            Box::pin(ready(result))
430        }
431
432        async fn unlink(
433            self: Arc<Self>,
434            name: &str,
435            _must_be_directory: bool,
436        ) -> Result<(), Status> {
437            self.fs.handle_event(MutableDirectoryAction::Unlink {
438                id: self.id,
439                name: name.to_string(),
440            })
441        }
442
443        async fn update_attributes(
444            &self,
445            attributes: fio::MutableNodeAttributes,
446        ) -> Result<(), Status> {
447            self.fs
448                .handle_event(MutableDirectoryAction::UpdateAttributes { id: self.id, attributes })
449        }
450
451        async fn sync(&self) -> Result<(), Status> {
452            self.fs.handle_event(MutableDirectoryAction::Sync)
453        }
454
455        fn rename(
456            self: Arc<Self>,
457            src_dir: Arc<dyn MutableDirectory>,
458            src_name: Path,
459            dst_name: Path,
460        ) -> BoxFuture<'static, Result<(), Status>> {
461            let src_dir = src_dir.into_any().downcast::<MockDirectory>().unwrap();
462            let result = self.fs.handle_event(MutableDirectoryAction::Rename {
463                id: src_dir.id,
464                src_name: src_name.into_string(),
465                dst_dir: self.id,
466                dst_name: dst_name.into_string(),
467            });
468            Box::pin(ready(result))
469        }
470    }
471
472    struct Events(Mutex<Vec<MutableDirectoryAction>>);
473
474    impl Events {
475        fn new() -> Arc<Self> {
476            Arc::new(Events(Mutex::new(vec![])))
477        }
478    }
479
480    struct MockFilesystem {
481        cur_id: Mutex<u32>,
482        scope: ExecutionScope,
483        events: Weak<Events>,
484    }
485
486    impl MockFilesystem {
487        pub fn new(events: &Arc<Events>) -> Self {
488            let scope = ExecutionScope::new();
489            MockFilesystem { cur_id: Mutex::new(0), scope, events: Arc::downgrade(events) }
490        }
491
492        pub fn handle_event(&self, event: MutableDirectoryAction) -> Result<(), Status> {
493            self.events.upgrade().map(|x| x.0.lock().unwrap().push(event));
494            Ok(())
495        }
496
497        pub fn make_connection(
498            self: &Arc<Self>,
499            flags: fio::OpenFlags,
500        ) -> (Arc<MockDirectory>, fio::DirectoryProxy) {
501            let mut cur_id = self.cur_id.lock().unwrap();
502            let dir = MockDirectory::new(*cur_id, self.clone());
503            *cur_id += 1;
504            let (proxy, server_end) = fidl::endpoints::create_proxy::<fio::DirectoryMarker>();
505            flags.to_object_request(server_end).create_connection_sync::<MutableConnection<_>, _>(
506                self.scope.clone(),
507                dir.clone(),
508                flags,
509            );
510            (dir, proxy)
511        }
512    }
513
514    impl std::fmt::Debug for MockFilesystem {
515        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
516            f.debug_struct("MockFilesystem").field("cur_id", &self.cur_id).finish()
517        }
518    }
519
520    #[fuchsia::test]
521    async fn test_rename() {
522        use fidl::Event;
523
524        let events = Events::new();
525        let fs = Arc::new(MockFilesystem::new(&events));
526
527        let (_dir, proxy) = fs
528            .clone()
529            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
530        let (dir2, proxy2) = fs
531            .clone()
532            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
533
534        let (status, token) = proxy2.get_token().await.unwrap();
535        assert_eq!(Status::from_raw(status), Status::OK);
536
537        let status = proxy.rename("src", Event::from(token.unwrap()), "dest").await.unwrap();
538        assert!(status.is_ok());
539
540        let events = events.0.lock().unwrap();
541        assert_eq!(
542            *events,
543            vec![MutableDirectoryAction::Rename {
544                id: 0,
545                src_name: "src".to_owned(),
546                dst_dir: dir2.id,
547                dst_name: "dest".to_owned(),
548            },]
549        );
550    }
551
552    #[fuchsia::test]
553    async fn test_update_attributes() {
554        let events = Events::new();
555        let fs = Arc::new(MockFilesystem::new(&events));
556        let (_dir, proxy) = fs
557            .clone()
558            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
559        let attributes = fio::MutableNodeAttributes {
560            creation_time: Some(30),
561            modification_time: Some(100),
562            mode: Some(200),
563            ..Default::default()
564        };
565        proxy
566            .update_attributes(&attributes)
567            .await
568            .expect("FIDL call failed")
569            .map_err(Status::from_raw)
570            .expect("update attributes failed");
571
572        let events = events.0.lock().unwrap();
573        assert_eq!(*events, vec![MutableDirectoryAction::UpdateAttributes { id: 0, attributes }]);
574    }
575
576    #[fuchsia::test]
577    async fn test_link() {
578        let events = Events::new();
579        let fs = Arc::new(MockFilesystem::new(&events));
580        let (_dir, proxy) = fs
581            .clone()
582            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
583        let (_dir2, proxy2) = fs
584            .clone()
585            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
586
587        let (status, token) = proxy2.get_token().await.unwrap();
588        assert_eq!(Status::from_raw(status), Status::OK);
589
590        let status = proxy.link("src", token.unwrap(), "dest").await.unwrap();
591        assert_eq!(Status::from_raw(status), Status::OK);
592        let events = events.0.lock().unwrap();
593        assert_eq!(*events, vec![MutableDirectoryAction::Link { id: 1, path: "dest".to_owned() },]);
594    }
595
596    #[fuchsia::test]
597    async fn test_unlink() {
598        let events = Events::new();
599        let fs = Arc::new(MockFilesystem::new(&events));
600        let (_dir, proxy) = fs
601            .clone()
602            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
603        proxy
604            .unlink("test", &fio::UnlinkOptions::default())
605            .await
606            .expect("fidl call failed")
607            .expect("unlink failed");
608        let events = events.0.lock().unwrap();
609        assert_eq!(
610            *events,
611            vec![MutableDirectoryAction::Unlink { id: 0, name: "test".to_string() },]
612        );
613    }
614
615    #[fuchsia::test]
616    async fn test_sync() {
617        let events = Events::new();
618        let fs = Arc::new(MockFilesystem::new(&events));
619        let (_dir, proxy) = fs
620            .clone()
621            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
622        let () = proxy.sync().await.unwrap().map_err(Status::from_raw).unwrap();
623        let events = events.0.lock().unwrap();
624        assert_eq!(*events, vec![MutableDirectoryAction::Sync]);
625    }
626
627    #[fuchsia::test]
628    async fn test_close() {
629        let events = Events::new();
630        let fs = Arc::new(MockFilesystem::new(&events));
631        let (_dir, proxy) = fs
632            .clone()
633            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
634        let () = proxy.close().await.unwrap().map_err(Status::from_raw).unwrap();
635        let events = events.0.lock().unwrap();
636        assert_eq!(*events, vec![MutableDirectoryAction::Close]);
637    }
638
639    #[fuchsia::test]
640    async fn test_implicit_close() {
641        let events = Events::new();
642        let fs = Arc::new(MockFilesystem::new(&events));
643        let (_dir, _proxy) = fs
644            .clone()
645            .make_connection(fio::OpenFlags::RIGHT_READABLE | fio::OpenFlags::RIGHT_WRITABLE);
646
647        fs.scope.shutdown();
648        fs.scope.wait().await;
649
650        let events = events.0.lock().unwrap();
651        assert_eq!(*events, vec![MutableDirectoryAction::Close]);
652    }
653}