package_directory/
non_meta_subdir.rs

1// Copyright 2021 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
5use crate::root_dir::RootDir;
6use anyhow::anyhow;
7use fidl::endpoints::ServerEnd;
8use fidl_fuchsia_io as fio;
9use log::error;
10use std::sync::Arc;
11use vfs::common::send_on_open_with_error;
12use vfs::directory::entry::EntryInfo;
13use vfs::directory::immutable::connection::ImmutableConnection;
14use vfs::directory::traversal_position::TraversalPosition;
15use vfs::execution_scope::ExecutionScope;
16use vfs::{ObjectRequestRef, ToObjectRequest as _, immutable_attributes};
17
18pub(crate) struct NonMetaSubdir<S: crate::NonMetaStorage> {
19    root_dir: Arc<RootDir<S>>,
20    // The object relative path expression of the subdir relative to the package root with a
21    // trailing slash appended.
22    path: String,
23}
24
25impl<S: crate::NonMetaStorage> NonMetaSubdir<S> {
26    pub(crate) fn new(root_dir: Arc<RootDir<S>>, path: String) -> Arc<Self> {
27        Arc::new(NonMetaSubdir { root_dir, path })
28    }
29}
30
31impl<S: crate::NonMetaStorage> vfs::directory::entry::GetEntryInfo for NonMetaSubdir<S> {
32    fn entry_info(&self) -> EntryInfo {
33        EntryInfo::new(fio::INO_UNKNOWN, fio::DirentType::Directory)
34    }
35}
36
37impl<S: crate::NonMetaStorage> vfs::node::Node for NonMetaSubdir<S> {
38    async fn get_attributes(
39        &self,
40        requested_attributes: fio::NodeAttributesQuery,
41    ) -> Result<fio::NodeAttributes2, zx::Status> {
42        Ok(immutable_attributes!(
43            requested_attributes,
44            Immutable {
45                protocols: fio::NodeProtocolKinds::DIRECTORY,
46                abilities: crate::DIRECTORY_ABILITIES,
47                id: 1,
48            }
49        ))
50    }
51}
52
53impl<S: crate::NonMetaStorage> vfs::directory::entry_container::Directory for NonMetaSubdir<S> {
54    fn deprecated_open(
55        self: Arc<Self>,
56        scope: ExecutionScope,
57        flags: fio::OpenFlags,
58        path: vfs::Path,
59        server_end: ServerEnd<fio::NodeMarker>,
60    ) {
61        let flags = flags & !fio::OpenFlags::POSIX_WRITABLE;
62        let describe = flags.contains(fio::OpenFlags::DESCRIBE);
63        // Disallow creating a writable connection to this node or any children. We also disallow
64        // file flags which do not apply. Note that the latter is not required for Open3, as we
65        // require writable rights for the latter flags already.
66        if flags.intersects(fio::OpenFlags::RIGHT_WRITABLE | fio::OpenFlags::TRUNCATE) {
67            let () = send_on_open_with_error(describe, server_end, zx::Status::NOT_SUPPORTED);
68            return;
69        }
70        // The VFS should disallow file creation since we cannot serve a mutable connection.
71        assert!(!flags.intersects(fio::OpenFlags::CREATE | fio::OpenFlags::CREATE_IF_ABSENT));
72
73        // Handle case where the request is for this directory itself (e.g. ".").
74        if path.is_empty() {
75            flags.to_object_request(server_end).handle(|object_request| {
76                // NOTE: Some older CTF tests still rely on being able to use the APPEND flag in
77                // some cases, so we cannot check this flag above. Appending is still not possible.
78                // As we plan to remove this method entirely, we can just leave this for now.
79                if flags.intersects(fio::OpenFlags::APPEND) {
80                    return Err(zx::Status::NOT_SUPPORTED);
81                }
82
83                object_request
84                    .take()
85                    .create_connection_sync::<ImmutableConnection<_>, _>(scope, self, flags);
86                Ok(())
87            });
88            return;
89        }
90
91        // `path` is relative, and may include a trailing slash.
92        let file_path = format!(
93            "{}{}",
94            self.path,
95            path.as_ref().strip_suffix('/').unwrap_or_else(|| path.as_ref())
96        );
97
98        if let Some(blob) = self.root_dir.non_meta_files.get(&file_path) {
99            let () = self
100                .root_dir
101                .non_meta_storage
102                .deprecated_open(blob, flags, scope, server_end)
103                .unwrap_or_else(|e| {
104                    error!("Error forwarding content blob open to blobfs: {:#}", anyhow!(e))
105                });
106            return;
107        }
108
109        if let Some(subdir) = self.root_dir.get_non_meta_subdir(file_path + "/") {
110            let () = subdir.deprecated_open(scope, flags, vfs::Path::dot(), server_end);
111            return;
112        }
113
114        let () = send_on_open_with_error(describe, server_end, zx::Status::NOT_FOUND);
115    }
116
117    fn open(
118        self: Arc<Self>,
119        scope: ExecutionScope,
120        path: vfs::Path,
121        flags: fio::Flags,
122        object_request: ObjectRequestRef<'_>,
123    ) -> Result<(), zx::Status> {
124        if !flags.difference(crate::ALLOWED_FLAGS).is_empty() {
125            return Err(zx::Status::NOT_SUPPORTED);
126        }
127
128        // Handle case where the request is for this directory itself (e.g. ".").
129        if path.is_empty() {
130            // `ImmutableConnection` checks that only directory flags are specified.
131            object_request
132                .take()
133                .create_connection_sync::<ImmutableConnection<_>, _>(scope, self, flags);
134            return Ok(());
135        }
136
137        // `path` is relative, and may include a trailing slash.
138        let file_path = format!(
139            "{}{}",
140            self.path,
141            path.as_ref().strip_suffix('/').unwrap_or_else(|| path.as_ref())
142        );
143
144        if let Some(blob) = self.root_dir.non_meta_files.get(&file_path) {
145            if path.is_dir() {
146                return Err(zx::Status::NOT_DIR);
147            }
148            return self.root_dir.non_meta_storage.open(blob, flags, scope, object_request);
149        }
150
151        if let Some(subdir) = self.root_dir.get_non_meta_subdir(file_path + "/") {
152            return subdir.open(scope, vfs::Path::dot(), flags, object_request);
153        }
154
155        Err(zx::Status::NOT_FOUND)
156    }
157
158    async fn read_dirents<'a>(
159        &'a self,
160        pos: &'a TraversalPosition,
161        sink: Box<dyn vfs::directory::dirents_sink::Sink + 'static>,
162    ) -> Result<
163        (TraversalPosition, Box<dyn vfs::directory::dirents_sink::Sealed + 'static>),
164        zx::Status,
165    > {
166        vfs::directory::read_dirents::read_dirents(
167            &crate::get_dir_children(
168                self.root_dir.non_meta_files.keys().map(|s| s.as_str()),
169                &self.path,
170            ),
171            pos,
172            sink,
173        )
174    }
175
176    fn register_watcher(
177        self: Arc<Self>,
178        _: ExecutionScope,
179        _: fio::WatchMask,
180        _: vfs::directory::entry_container::DirectoryWatcher,
181    ) -> Result<(), zx::Status> {
182        Err(zx::Status::NOT_SUPPORTED)
183    }
184
185    // `register_watcher` is unsupported so no need to do anything here.
186    fn unregister_watcher(self: Arc<Self>, _: usize) {}
187}
188
189#[cfg(test)]
190mod tests {
191    use super::*;
192    use assert_matches::assert_matches;
193    use fuchsia_fs::directory::{DirEntry, DirentKind};
194    use fuchsia_pkg_testing::PackageBuilder;
195    use fuchsia_pkg_testing::blobfs::Fake as FakeBlobfs;
196    use futures::prelude::*;
197
198    struct TestEnv {
199        _blobfs_fake: FakeBlobfs,
200    }
201
202    impl TestEnv {
203        async fn new() -> (Self, fio::DirectoryProxy) {
204            let pkg = PackageBuilder::new("pkg")
205                .add_resource_at("dir0/dir1/file", "bloblob".as_bytes())
206                .build()
207                .await
208                .unwrap();
209            let (metafar_blob, content_blobs) = pkg.contents();
210            let (blobfs_fake, blobfs_client) = FakeBlobfs::new();
211            blobfs_fake.add_blob(metafar_blob.merkle, metafar_blob.contents);
212            for (hash, bytes) in content_blobs {
213                blobfs_fake.add_blob(hash, bytes);
214            }
215            let root_dir = RootDir::new(blobfs_client, metafar_blob.merkle).await.unwrap();
216            let sub_dir = NonMetaSubdir::new(root_dir, "dir0/".to_string());
217            (Self { _blobfs_fake: blobfs_fake }, vfs::directory::serve_read_only(sub_dir))
218        }
219    }
220
221    /// Ensure connections to a [`NonMetaSubdir`] cannot be created as mutable (i.e. with
222    /// [`fio::PERM_WRITABLE`]) This ensures that the VFS will disallow any attempts to create a new
223    /// file/directory, modify the attributes of any nodes, or open any files as writable.
224    #[fuchsia_async::run_singlethreaded(test)]
225    async fn non_meta_subdir_cannot_be_served_as_mutable() {
226        let pkg = PackageBuilder::new("pkg")
227            .add_resource_at("dir0/dir1/file", "bloblob".as_bytes())
228            .build()
229            .await
230            .unwrap();
231        let (metafar_blob, content_blobs) = pkg.contents();
232        let (blobfs_fake, blobfs_client) = FakeBlobfs::new();
233        blobfs_fake.add_blob(metafar_blob.merkle, metafar_blob.contents);
234        for (hash, bytes) in content_blobs {
235            blobfs_fake.add_blob(hash, bytes);
236        }
237        let root_dir = RootDir::new(blobfs_client, metafar_blob.merkle).await.unwrap();
238        let sub_dir = NonMetaSubdir::new(root_dir, "dir0/".to_string());
239        let proxy = vfs::directory::serve(sub_dir, fio::PERM_WRITABLE);
240        assert_matches!(
241            proxy.take_event_stream().try_next().await,
242            Err(fidl::Error::ClientChannelClosed { status: zx::Status::NOT_SUPPORTED, .. })
243        );
244    }
245
246    #[fuchsia_async::run_singlethreaded(test)]
247    async fn non_meta_subdir_readdir() {
248        let (_env, sub_dir) = TestEnv::new().await;
249        assert_eq!(
250            fuchsia_fs::directory::readdir_inclusive(&sub_dir).await.unwrap(),
251            vec![
252                DirEntry { name: ".".to_string(), kind: DirentKind::Directory },
253                DirEntry { name: "dir1".to_string(), kind: DirentKind::Directory }
254            ]
255        );
256    }
257
258    #[fuchsia_async::run_singlethreaded(test)]
259    async fn non_meta_subdir_get_attributes() {
260        let (_env, sub_dir) = TestEnv::new().await;
261        let (mutable_attributes, immutable_attributes) =
262            sub_dir.get_attributes(fio::NodeAttributesQuery::all()).await.unwrap().unwrap();
263        assert_eq!(
264            fio::NodeAttributes2 { mutable_attributes, immutable_attributes },
265            immutable_attributes!(
266                fio::NodeAttributesQuery::all(),
267                Immutable {
268                    protocols: fio::NodeProtocolKinds::DIRECTORY,
269                    abilities: crate::DIRECTORY_ABILITIES,
270                    id: 1,
271                }
272            )
273        );
274    }
275
276    #[fuchsia_async::run_singlethreaded(test)]
277    async fn non_meta_subdir_watch_not_supported() {
278        let (_env, sub_dir) = TestEnv::new().await;
279        let (_client, server) = fidl::endpoints::create_endpoints();
280        let status =
281            zx::Status::from_raw(sub_dir.watch(fio::WatchMask::empty(), 0, server).await.unwrap());
282        assert_eq!(status, zx::Status::NOT_SUPPORTED);
283    }
284
285    #[fuchsia_async::run_singlethreaded(test)]
286    async fn non_meta_subdir_open_directory() {
287        let (_env, sub_dir) = TestEnv::new().await;
288        for path in ["dir1", "dir1/"] {
289            let proxy = fuchsia_fs::directory::open_directory(&sub_dir, path, fio::PERM_READABLE)
290                .await
291                .unwrap();
292            assert_eq!(
293                fuchsia_fs::directory::readdir(&proxy).await.unwrap(),
294                vec![DirEntry { name: "file".to_string(), kind: DirentKind::File }]
295            );
296        }
297    }
298
299    #[fuchsia_async::run_singlethreaded(test)]
300    async fn non_meta_subdir_open_file() {
301        let (_env, sub_dir) = TestEnv::new().await;
302        let proxy = fuchsia_fs::directory::open_file(&sub_dir, "dir1/file", fio::PERM_READABLE)
303            .await
304            .unwrap();
305        assert_eq!(fuchsia_fs::file::read(&proxy).await.unwrap(), b"bloblob".to_vec())
306    }
307
308    #[fuchsia_async::run_singlethreaded(test)]
309    async fn non_meta_subdir_deprecated_open_directory() {
310        let (_env, sub_dir) = TestEnv::new().await;
311        for path in ["dir1", "dir1/"] {
312            let (proxy, server_end) = fidl::endpoints::create_proxy::<fio::DirectoryMarker>();
313            sub_dir
314                .deprecated_open(
315                    fio::OpenFlags::RIGHT_READABLE,
316                    Default::default(),
317                    path,
318                    server_end.into_channel().into(),
319                )
320                .unwrap();
321            assert_eq!(
322                fuchsia_fs::directory::readdir(&proxy).await.unwrap(),
323                vec![DirEntry { name: "file".to_string(), kind: DirentKind::File }]
324            );
325        }
326    }
327
328    #[fuchsia_async::run_singlethreaded(test)]
329    async fn non_meta_subdir_deprecated_open_file() {
330        let (_env, sub_dir) = TestEnv::new().await;
331        let (proxy, server_end) = fidl::endpoints::create_proxy::<fio::FileMarker>();
332        sub_dir
333            .deprecated_open(
334                fio::OpenFlags::RIGHT_READABLE,
335                Default::default(),
336                "dir1/file",
337                server_end.into_channel().into(),
338            )
339            .unwrap();
340        assert_eq!(fuchsia_fs::file::read(&proxy).await.unwrap(), b"bloblob".to_vec());
341    }
342}
package_directory/non_meta_subdir.rs

package_directory/
non_meta_subdir.rs
