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 <pthread.h>
21 #include <fnmatch.h>
22 #include <stdlib.h>
23 
24 #ifdef __cplusplus
25 
26 #include <list>
27 #include <mutex>
28 #include <string>
29 #include <unordered_map>
30 #include <unordered_set>
31 
32 #include <cutils/multiuser.h>
33 #include <utils/List.h>
34 #include <utils/Timers.h>
35 #include <sysutils/SocketListener.h>
36 #include <sysutils/NetlinkEvent.h>
37 
38 #include "Disk.h"
39 #include "VolumeBase.h"
40 
41 /* The length of an MD5 hash when encoded into ASCII hex characters */
42 #define MD5_ASCII_LENGTH_PLUS_NULL ((MD5_DIGEST_LENGTH*2)+1)
43 
44 typedef enum { ASEC, OBB } container_type_t;
45 
46 class ContainerData {
47 public:
ContainerData(char * _id,container_type_t _type)48     ContainerData(char* _id, container_type_t _type)
49             : id(_id)
50             , type(_type)
51     {}
52 
~ContainerData()53     ~ContainerData() {
54         if (id != NULL) {
55             free(id);
56             id = NULL;
57         }
58     }
59 
60     char *id;
61     container_type_t type;
62 };
63 
64 typedef android::List<ContainerData*> AsecIdCollection;
65 
66 class VolumeManager {
67 public:
68     static const char *SEC_ASECDIR_EXT;
69     static const char *SEC_ASECDIR_INT;
70     static const char *ASECDIR;
71     static const char *LOOPDIR;
72 
73 private:
74     static VolumeManager *sInstance;
75 
76     SocketListener        *mBroadcaster;
77 
78     AsecIdCollection      *mActiveContainers;
79     bool                   mDebug;
80 
81     // for adjusting /proc/sys/vm/dirty_ratio when UMS is active
82     int                    mUmsSharingCount;
83     int                    mSavedDirtyRatio;
84     int                    mUmsDirtyRatio;
85 
86 public:
87     virtual ~VolumeManager();
88 
89     // TODO: pipe all requests through VM to avoid exposing this lock
getLock()90     std::mutex& getLock() { return mLock; }
91 
92     int start();
93     int stop();
94 
95     void handleBlockEvent(NetlinkEvent *evt);
96 
97     class DiskSource {
98     public:
DiskSource(const std::string & sysPattern,const std::string & nickname,int flags)99         DiskSource(const std::string& sysPattern, const std::string& nickname, int flags) :
100                 mSysPattern(sysPattern), mNickname(nickname), mFlags(flags) {
101         }
102 
matches(const std::string & sysPath)103         bool matches(const std::string& sysPath) {
104             return !fnmatch(mSysPattern.c_str(), sysPath.c_str(), 0);
105         }
106 
getNickname()107         const std::string& getNickname() { return mNickname; }
getFlags()108         int getFlags() { return mFlags; }
109 
110     private:
111         std::string mSysPattern;
112         std::string mNickname;
113         int mFlags;
114     };
115 
116     void addDiskSource(const std::shared_ptr<DiskSource>& diskSource);
117 
118     std::shared_ptr<android::vold::Disk> findDisk(const std::string& id);
119     std::shared_ptr<android::vold::VolumeBase> findVolume(const std::string& id);
120 
121     void listVolumes(android::vold::VolumeBase::Type type, std::list<std::string>& list);
122 
123     nsecs_t benchmarkPrivate(const std::string& id);
124 
125     int forgetPartition(const std::string& partGuid);
126 
127     int onUserAdded(userid_t userId, int userSerialNumber);
128     int onUserRemoved(userid_t userId);
129     int onUserStarted(userid_t userId);
130     int onUserStopped(userid_t userId);
131 
132     int setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol);
133 
134     int remountUid(uid_t uid, const std::string& mode);
135 
136     /* Reset all internal state, typically during framework boot */
137     int reset();
138     /* Prepare for device shutdown, safely unmounting all devices */
139     int shutdown();
140     /* Unmount all volumes, usually for encryption */
141     int unmountAll();
142 
143     /* ASEC */
144     int findAsec(const char *id, char *asecPath = NULL, size_t asecPathLen = 0,
145             const char **directory = NULL) const;
146     int createAsec(const char *id, unsigned numSectors, const char *fstype,
147                    const char *key, const int ownerUid, bool isExternal);
148     int resizeAsec(const char *id, unsigned numSectors, const char *key);
149     int finalizeAsec(const char *id);
150 
151     /**
152      * Fixes ASEC permissions on a filesystem that has owners and permissions.
153      * This currently means EXT4-based ASEC containers.
154      *
155      * There is a single file that can be marked as "private" and will not have
156      * world-readable permission. The group for that file will be set to the gid
157      * supplied.
158      *
159      * Returns 0 on success.
160      */
161     int fixupAsecPermissions(const char *id, gid_t gid, const char* privateFilename);
162     int destroyAsec(const char *id, bool force);
163     int mountAsec(const char *id, const char *key, int ownerUid, bool readOnly);
164     int unmountAsec(const char *id, bool force);
165     int renameAsec(const char *id1, const char *id2);
166     int getAsecMountPath(const char *id, char *buffer, int maxlen);
167     int getAsecFilesystemPath(const char *id, char *buffer, int maxlen);
168 
169     /* Loopback images */
170     int listMountedObbs(SocketClient* cli);
171     int mountObb(const char *fileName, const char *key, int ownerUid);
172     int unmountObb(const char *fileName, bool force);
173     int getObbMountPath(const char *id, char *buffer, int maxlen);
174 
175     /* Shared between ASEC and Loopback images */
176     int unmountLoopImage(const char *containerId, const char *loopId,
177             const char *fileName, const char *mountPoint, bool force);
178 
179     int setDebug(bool enable);
180 
setBroadcaster(SocketListener * sl)181     void setBroadcaster(SocketListener *sl) { mBroadcaster = sl; }
getBroadcaster()182     SocketListener *getBroadcaster() { return mBroadcaster; }
183 
184     static VolumeManager *Instance();
185 
186     static char *asecHash(const char *id, char *buffer, size_t len);
187 
188     /*
189      * Ensure that all directories along given path exist, creating parent
190      * directories as needed.  Validates that given path is absolute and that
191      * it contains no relative "." or ".." paths or symlinks.  Last path segment
192      * is treated as filename and ignored, unless the path ends with "/".  Also
193      * ensures that path belongs to a volume managed by vold.
194      */
195     int mkdirs(char* path);
196 
197 private:
198     VolumeManager();
199     void readInitialState();
200     bool isMountpointMounted(const char *mp);
201     bool isAsecInDirectory(const char *dir, const char *asec) const;
202     bool isLegalAsecId(const char *id) const;
203 
204     int linkPrimary(userid_t userId);
205 
206     std::mutex mLock;
207 
208     std::list<std::shared_ptr<DiskSource>> mDiskSources;
209     std::list<std::shared_ptr<android::vold::Disk>> mDisks;
210 
211     std::unordered_map<userid_t, int> mAddedUsers;
212     std::unordered_set<userid_t> mStartedUsers;
213 
214     std::shared_ptr<android::vold::VolumeBase> mInternalEmulated;
215     std::shared_ptr<android::vold::VolumeBase> mPrimary;
216 };
217 
218 extern "C" {
219 #endif /* __cplusplus */
220 #define UNMOUNT_NOT_MOUNTED_ERR -2
221     int vold_unmountAll(void);
222 #ifdef __cplusplus
223 }
224 #endif
225 
226 #endif
227