1 /* 2 * Copyright (C) 2015 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_UTILS_H 18 #define ANDROID_VOLD_UTILS_H 19 20 #include "KeyBuffer.h" 21 22 #include <android-base/macros.h> 23 #include <android-base/unique_fd.h> 24 #include <cutils/multiuser.h> 25 #include <selinux/selinux.h> 26 #include <utils/Errors.h> 27 28 #include <chrono> 29 #include <string> 30 #include <vector> 31 32 struct DIR; 33 34 namespace android { 35 namespace vold { 36 37 static const char* kPropFuse = "persist.sys.fuse"; 38 static const char* kVoldAppDataIsolationEnabled = "persist.sys.vold_app_data_isolation_enabled"; 39 static const char* kExternalStorageSdcardfs = "external_storage.sdcardfs.enabled"; 40 41 /* SELinux contexts used depending on the block device type */ 42 extern security_context_t sBlkidContext; 43 extern security_context_t sBlkidUntrustedContext; 44 extern security_context_t sFsckContext; 45 extern security_context_t sFsckUntrustedContext; 46 47 // TODO remove this with better solution, b/64143519 48 extern bool sSleepOnUnmount; 49 50 std::string GetFuseMountPathForUser(userid_t user_id, const std::string& relative_upper_path); 51 52 status_t CreateDeviceNode(const std::string& path, dev_t dev); 53 status_t DestroyDeviceNode(const std::string& path); 54 55 status_t AbortFuseConnections(); 56 57 int SetQuotaInherit(const std::string& path); 58 int SetQuotaProjectId(const std::string& path, long projectId); 59 /* 60 * Creates and sets up an application-specific path on external 61 * storage with the correct ACL and project ID (if needed). 62 * 63 * ONLY for use with app-specific data directories on external storage! 64 * (eg, /Android/data/com.foo, /Android/obb/com.foo, etc.) 65 */ 66 int PrepareAppDirFromRoot(const std::string& path, const std::string& root, int appUid, 67 bool fixupExisting); 68 69 /* fs_prepare_dir wrapper that creates with SELinux context */ 70 status_t PrepareDir(const std::string& path, mode_t mode, uid_t uid, gid_t gid, 71 unsigned int attrs = 0); 72 73 /* Really unmounts the path, killing active processes along the way */ 74 status_t ForceUnmount(const std::string& path); 75 76 /* Kills any processes using given path */ 77 status_t KillProcessesUsingPath(const std::string& path); 78 79 /* Kills any processes using given mount prifix */ 80 status_t KillProcessesWithMountPrefix(const std::string& path); 81 82 /* Creates bind mount from source to target */ 83 status_t BindMount(const std::string& source, const std::string& target); 84 85 /** Creates a symbolic link to target */ 86 status_t Symlink(const std::string& target, const std::string& linkpath); 87 88 /** Calls unlink(2) at linkpath */ 89 status_t Unlink(const std::string& linkpath); 90 91 /** Creates the given directory if it is not already available */ 92 status_t CreateDir(const std::string& dir, mode_t mode); 93 94 bool FindValue(const std::string& raw, const std::string& key, std::string* value); 95 96 /* Reads filesystem metadata from device at path */ 97 status_t ReadMetadata(const std::string& path, std::string* fsType, std::string* fsUuid, 98 std::string* fsLabel); 99 100 /* Reads filesystem metadata from untrusted device at path */ 101 status_t ReadMetadataUntrusted(const std::string& path, std::string* fsType, std::string* fsUuid, 102 std::string* fsLabel); 103 104 /* Returns either WEXITSTATUS() status, or a negative errno */ 105 status_t ForkExecvp(const std::vector<std::string>& args, std::vector<std::string>* output = nullptr, 106 security_context_t context = nullptr); 107 108 pid_t ForkExecvpAsync(const std::vector<std::string>& args); 109 110 /* Gets block device size in bytes */ 111 status_t GetBlockDevSize(int fd, uint64_t* size); 112 status_t GetBlockDevSize(const std::string& path, uint64_t* size); 113 /* Gets block device size in 512 byte sectors */ 114 status_t GetBlockDev512Sectors(const std::string& path, uint64_t* nr_sec); 115 116 status_t ReadRandomBytes(size_t bytes, std::string& out); 117 status_t ReadRandomBytes(size_t bytes, char* buffer); 118 status_t GenerateRandomUuid(std::string& out); 119 120 /* Converts hex string to raw bytes, ignoring [ :-] */ 121 status_t HexToStr(const std::string& hex, std::string& str); 122 /* Converts raw bytes to hex string */ 123 status_t StrToHex(const std::string& str, std::string& hex); 124 /* Converts raw key bytes to hex string */ 125 status_t StrToHex(const KeyBuffer& str, KeyBuffer& hex); 126 /* Normalize given hex string into consistent format */ 127 status_t NormalizeHex(const std::string& in, std::string& out); 128 129 uint64_t GetFreeBytes(const std::string& path); 130 uint64_t GetTreeBytes(const std::string& path); 131 132 bool IsFilesystemSupported(const std::string& fsType); 133 bool IsSdcardfsUsed(); 134 bool IsFuseDaemon(const pid_t pid); 135 136 /* Wipes contents of block device at given path */ 137 status_t WipeBlockDevice(const std::string& path); 138 139 std::string BuildKeyPath(const std::string& partGuid); 140 141 std::string BuildDataSystemLegacyPath(userid_t userid); 142 std::string BuildDataSystemCePath(userid_t userid); 143 std::string BuildDataSystemDePath(userid_t userid); 144 std::string BuildDataMiscLegacyPath(userid_t userid); 145 std::string BuildDataMiscCePath(userid_t userid); 146 std::string BuildDataMiscDePath(userid_t userid); 147 std::string BuildDataProfilesDePath(userid_t userid); 148 std::string BuildDataVendorCePath(userid_t userid); 149 std::string BuildDataVendorDePath(userid_t userid); 150 151 std::string BuildDataPath(const std::string& volumeUuid); 152 std::string BuildDataMediaCePath(const std::string& volumeUuid, userid_t userid); 153 std::string BuildDataUserCePath(const std::string& volumeUuid, userid_t userid); 154 std::string BuildDataUserDePath(const std::string& volumeUuid, userid_t userid); 155 156 dev_t GetDevice(const std::string& path); 157 158 status_t EnsureDirExists(const std::string& path, mode_t mode, uid_t uid, gid_t gid); 159 160 status_t RestoreconRecursive(const std::string& path); 161 162 // TODO: promote to android::base 163 bool Readlinkat(int dirfd, const std::string& path, std::string* result); 164 165 // Handles dynamic major assignment for virtio-block 166 bool IsVirtioBlkDevice(unsigned int major); 167 168 status_t UnmountTreeWithPrefix(const std::string& prefix); 169 status_t UnmountTree(const std::string& mountPoint); 170 171 status_t DeleteDirContentsAndDir(const std::string& pathname); 172 status_t DeleteDirContents(const std::string& pathname); 173 174 status_t WaitForFile(const char* filename, std::chrono::nanoseconds timeout); 175 176 bool FsyncDirectory(const std::string& dirname); 177 178 bool writeStringToFile(const std::string& payload, const std::string& filename); 179 180 void ConfigureMaxDirtyRatioForFuse(const std::string& fuse_mount, unsigned int max_ratio); 181 182 void ConfigureReadAheadForFuse(const std::string& fuse_mount, size_t read_ahead_kb); 183 184 status_t MountUserFuse(userid_t user_id, const std::string& absolute_lower_path, 185 const std::string& relative_upper_path, android::base::unique_fd* fuse_fd); 186 187 status_t UnmountUserFuse(userid_t userId, const std::string& absolute_lower_path, 188 const std::string& relative_upper_path); 189 190 status_t PrepareAndroidDirs(const std::string& volumeRoot); 191 } // namespace vold 192 } // namespace android 193 194 #endif 195