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1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_VOLD_VOLUME_MANAGER_H
18 #define ANDROID_VOLD_VOLUME_MANAGER_H
19 
20 #include <fnmatch.h>
21 #include <pthread.h>
22 #include <stdlib.h>
23 
24 #include <list>
25 #include <mutex>
26 #include <set>
27 #include <string>
28 #include <unordered_map>
29 #include <unordered_set>
30 
31 #include <android-base/unique_fd.h>
32 #include <cutils/multiuser.h>
33 #include <sysutils/NetlinkEvent.h>
34 #include <utils/List.h>
35 #include <utils/Timers.h>
36 
37 #include "android/os/IVoldListener.h"
38 
39 #include "model/Disk.h"
40 #include "model/VolumeBase.h"
41 
42 class VolumeManager {
43   private:
44     static VolumeManager* sInstance;
45 
46     bool mDebug;
47 
48   public:
49     virtual ~VolumeManager();
50 
51     // TODO: pipe all requests through VM to avoid exposing this lock
getLock()52     std::mutex& getLock() { return mLock; }
getCryptLock()53     std::mutex& getCryptLock() { return mCryptLock; }
54 
setListener(android::sp<android::os::IVoldListener> listener)55     void setListener(android::sp<android::os::IVoldListener> listener) { mListener = listener; }
getListener()56     android::sp<android::os::IVoldListener> getListener() const { return mListener; }
57 
58     int start();
59 
60     void handleBlockEvent(NetlinkEvent* evt);
61 
62     class DiskSource {
63       public:
DiskSource(const std::string & sysPattern,const std::string & nickname,int flags)64         DiskSource(const std::string& sysPattern, const std::string& nickname, int flags)
65             : mSysPattern(sysPattern), mNickname(nickname), mFlags(flags) {}
66 
matches(const std::string & sysPath)67         bool matches(const std::string& sysPath) {
68             return !fnmatch(mSysPattern.c_str(), sysPath.c_str(), 0);
69         }
70 
getNickname()71         const std::string& getNickname() const { return mNickname; }
getFlags()72         int getFlags() const { return mFlags; }
73 
74       private:
75         std::string mSysPattern;
76         std::string mNickname;
77         int mFlags;
78     };
79 
80     void addDiskSource(const std::shared_ptr<DiskSource>& diskSource);
81 
82     std::shared_ptr<android::vold::Disk> findDisk(const std::string& id);
83     std::shared_ptr<android::vold::VolumeBase> findVolume(const std::string& id);
84 
85     template <typename Fn>
findVolumeWithFilter(Fn fn)86     std::shared_ptr<android::vold::VolumeBase> findVolumeWithFilter(Fn fn) {
87         for (const auto& vol : mInternalEmulatedVolumes) {
88             if (fn(*vol)) {
89                 return vol;
90             }
91         }
92         for (const auto& disk : mDisks) {
93             for (const auto& vol : disk->getVolumes()) {
94                 if (fn(*vol)) {
95                     return vol;
96                 }
97             }
98         }
99 
100         return nullptr;
101     }
102 
103     void listVolumes(android::vold::VolumeBase::Type type, std::list<std::string>& list) const;
104 
getStartedUsers()105     const std::set<userid_t>& getStartedUsers() const { return mStartedUsers; }
106 
107     userid_t getSharedStorageUser(userid_t userId);
108 
109     bool forgetPartition(const std::string& partGuid, const std::string& fsUuid);
110 
111     int onUserAdded(userid_t userId, int userSerialNumber, userid_t cloneParentUserId);
112     int onUserRemoved(userid_t userId);
113     int onUserStarted(userid_t userId);
114     int onUserStopped(userid_t userId);
115 
116     void createPendingDisksIfNeeded();
117     int onSecureKeyguardStateChanged(bool isShowing);
118 
remountUid(uid_t uid,int32_t remountMode)119     int remountUid(uid_t uid, int32_t remountMode) { return 0; }
120     int handleAppStorageDirs(int uid, int pid,
121             bool doUnmount, const std::vector<std::string>& packageNames);
122 
123     /* Aborts all FUSE filesystems, in case the FUSE daemon is no longer up. */
124     int abortFuse();
125     /* Reset all internal state, typically during framework boot */
126     int reset();
127     /* Prepare for device shutdown, safely unmounting all devices */
128     int shutdown();
129     /* Unmount all volumes, usually for encryption */
130     int unmountAll();
131 
132     int updateVirtualDisk();
133     int setDebug(bool enable);
134 
135     bool forkAndRemountStorage(int uid, int pid, bool doUnmount,
136         const std::vector<std::string>& packageNames);
137 
138     static VolumeManager* Instance();
139 
140     /*
141      * Creates a directory 'path' for an application, automatically creating
142      * directories along the given path if they don't exist yet.
143      *
144      * Example:
145      *   path = /storage/emulated/0/Android/data/com.foo/files/
146      *
147      * This function will first match the first part of the path with the volume
148      * root of any known volumes; in this case, "/storage/emulated/0" matches
149      * with the volume root of the emulated volume for user 0.
150      *
151      * The subseqent part of the path must start with one of the well-known
152      * Android/ data directories, /Android/data, /Android/obb or
153      * /Android/media.
154      *
155      * The final part of the path is application specific. This function will
156      * create all directories, including the application-specific ones, and
157      * set the UID of all app-specific directories below the well-known data
158      * directories to the 'appUid' argument. In the given example, the UID
159      * of /storage/emulated/0/Android/data/com.foo and
160      * /storage/emulated/0/Android/data/com.foo/files would be set to 'appUid'.
161      *
162      * The UID/GID of the parent directories will be set according to the
163      * requirements of the underlying filesystem and are of no concern to the
164      * caller.
165      *
166      * If fixupExistingOnly is set, we make sure to fixup any existing dirs and
167      * files in the passed in path, but only if that path exists; if it doesn't
168      * exist, this function doesn't create them.
169      *
170      * If skipIfDirExists is set, we will not fix any existing dirs, we will
171      * only create app dirs if it doesn't exist.
172      *
173      * Validates that given paths are absolute and that they contain no relative
174      * "." or ".." paths or symlinks.  Last path segment is treated as filename
175      * and ignored, unless the path ends with "/".  Also ensures that path
176      * belongs to a volume managed by vold.
177      */
178     int setupAppDir(const std::string& path, int32_t appUid, bool fixupExistingOnly = false,
179             bool skipIfDirExists = false);
180 
181     /**
182      * Fixes up an existing application directory, as if it was created with
183      * setupAppDir() above. This includes fixing up the UID/GID, permissions and
184      * project IDs of the contained files and directories.
185      */
186     int fixupAppDir(const std::string& path, int32_t appUid);
187 
188     // Called before zygote starts to ensure dir exists so zygote can bind mount them.
189     int ensureAppDirsCreated(const std::vector<std::string>& paths, int32_t appUid);
190 
191     int createObb(const std::string& path, int32_t ownerGid, std::string* outVolId);
192     int destroyObb(const std::string& volId);
193 
194     int createStubVolume(const std::string& sourcePath, const std::string& mountPath,
195                          const std::string& fsType, const std::string& fsUuid,
196                          const std::string& fsLabel, int32_t flags, std::string* outVolId);
197     int destroyStubVolume(const std::string& volId);
198 
199     int mountAppFuse(uid_t uid, int mountId, android::base::unique_fd* device_fd);
200     int unmountAppFuse(uid_t uid, int mountId);
201     int openAppFuseFile(uid_t uid, int mountId, int fileId, int flags);
202 
203   private:
204     VolumeManager();
205     void readInitialState();
206 
207     int linkPrimary(userid_t userId);
208 
209     void createEmulatedVolumesForUser(userid_t userId);
210     void destroyEmulatedVolumesForUser(userid_t userId);
211 
212     void handleDiskAdded(const std::shared_ptr<android::vold::Disk>& disk);
213     void handleDiskChanged(dev_t device);
214     void handleDiskRemoved(dev_t device);
215 
216     bool updateFuseMountedProperty();
217 
218     std::mutex mLock;
219     std::mutex mCryptLock;
220 
221     android::sp<android::os::IVoldListener> mListener;
222 
223     std::list<std::shared_ptr<DiskSource>> mDiskSources;
224     std::list<std::shared_ptr<android::vold::Disk>> mDisks;
225     std::list<std::shared_ptr<android::vold::Disk>> mPendingDisks;
226     std::list<std::shared_ptr<android::vold::VolumeBase>> mObbVolumes;
227     std::list<std::shared_ptr<android::vold::VolumeBase>> mInternalEmulatedVolumes;
228 
229     std::unordered_map<userid_t, int> mAddedUsers;
230     // Map of users to a user with which they can share storage (eg clone profiles)
231     std::unordered_map<userid_t, userid_t> mSharedStorageUser;
232     // This needs to be a regular set because we care about the ordering here;
233     // user 0 should always go first, because it is responsible for sdcardfs.
234     std::set<userid_t> mStartedUsers;
235 
236     std::string mVirtualDiskPath;
237     std::shared_ptr<android::vold::Disk> mVirtualDisk;
238     std::shared_ptr<android::vold::VolumeBase> mPrimary;
239 
240     int mNextObbId;
241     int mNextStubId;
242     bool mSecureKeyguardShowing;
243 };
244 
245 namespace android {
246 namespace vold {
247 android::status_t GetStorageSize(int64_t* storageSize);
248 }
249 }  // namespace android
250 
251 #endif
252