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 #include "PrivateVolume.h"
18 #include "EmulatedVolume.h"
19 #include "Utils.h"
20 #include "VolumeManager.h"
21 #include "cryptfs.h"
22 #include "fs/Ext4.h"
23 #include "fs/F2fs.h"
24
25 #include <android-base/logging.h>
26 #include <android-base/stringprintf.h>
27 #include <cutils/fs.h>
28 #include <private/android_filesystem_config.h>
29
30 #include <fcntl.h>
31 #include <stdlib.h>
32 #include <sys/mount.h>
33 #include <sys/param.h>
34 #include <sys/stat.h>
35 #include <sys/sysmacros.h>
36 #include <sys/types.h>
37 #include <sys/wait.h>
38
39 using android::base::StringPrintf;
40
41 namespace android {
42 namespace vold {
43
44 static const unsigned int kMajorBlockMmc = 179;
45
PrivateVolume(dev_t device,const std::string & keyRaw)46 PrivateVolume::PrivateVolume(dev_t device, const std::string& keyRaw)
47 : VolumeBase(Type::kPrivate), mRawDevice(device), mKeyRaw(keyRaw) {
48 setId(StringPrintf("private:%u,%u", major(device), minor(device)));
49 mRawDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
50 }
51
~PrivateVolume()52 PrivateVolume::~PrivateVolume() {}
53
readMetadata()54 status_t PrivateVolume::readMetadata() {
55 status_t res = ReadMetadata(mDmDevPath, &mFsType, &mFsUuid, &mFsLabel);
56
57 auto listener = getListener();
58 if (listener) listener->onVolumeMetadataChanged(getId(), mFsType, mFsUuid, mFsLabel);
59
60 return res;
61 }
62
doCreate()63 status_t PrivateVolume::doCreate() {
64 if (CreateDeviceNode(mRawDevPath, mRawDevice)) {
65 return -EIO;
66 }
67 if (mKeyRaw.size() != cryptfs_get_keysize()) {
68 PLOG(ERROR) << getId() << " Raw keysize " << mKeyRaw.size()
69 << " does not match crypt keysize " << cryptfs_get_keysize();
70 return -EIO;
71 }
72
73 // Recover from stale vold by tearing down any old mappings
74 cryptfs_revert_ext_volume(getId().c_str());
75
76 // TODO: figure out better SELinux labels for private volumes
77
78 unsigned char* key = (unsigned char*)mKeyRaw.data();
79 char crypto_blkdev[MAXPATHLEN];
80 int res = cryptfs_setup_ext_volume(getId().c_str(), mRawDevPath.c_str(), key, crypto_blkdev);
81 mDmDevPath = crypto_blkdev;
82 if (res != 0) {
83 PLOG(ERROR) << getId() << " failed to setup cryptfs";
84 return -EIO;
85 }
86
87 return OK;
88 }
89
doDestroy()90 status_t PrivateVolume::doDestroy() {
91 if (cryptfs_revert_ext_volume(getId().c_str())) {
92 LOG(ERROR) << getId() << " failed to revert cryptfs";
93 }
94 return DestroyDeviceNode(mRawDevPath);
95 }
96
doMount()97 status_t PrivateVolume::doMount() {
98 if (readMetadata()) {
99 LOG(ERROR) << getId() << " failed to read metadata";
100 return -EIO;
101 }
102
103 mPath = StringPrintf("/mnt/expand/%s", mFsUuid.c_str());
104 setPath(mPath);
105
106 if (PrepareDir(mPath, 0700, AID_ROOT, AID_ROOT)) {
107 PLOG(ERROR) << getId() << " failed to create mount point " << mPath;
108 return -EIO;
109 }
110
111 if (mFsType == "ext4") {
112 int res = ext4::Check(mDmDevPath, mPath);
113 if (res == 0 || res == 1) {
114 LOG(DEBUG) << getId() << " passed filesystem check";
115 } else {
116 PLOG(ERROR) << getId() << " failed filesystem check";
117 return -EIO;
118 }
119
120 if (ext4::Mount(mDmDevPath, mPath, false, false, true)) {
121 PLOG(ERROR) << getId() << " failed to mount";
122 return -EIO;
123 }
124
125 } else if (mFsType == "f2fs") {
126 int res = f2fs::Check(mDmDevPath);
127 if (res == 0) {
128 LOG(DEBUG) << getId() << " passed filesystem check";
129 } else {
130 PLOG(ERROR) << getId() << " failed filesystem check";
131 return -EIO;
132 }
133
134 if (f2fs::Mount(mDmDevPath, mPath)) {
135 PLOG(ERROR) << getId() << " failed to mount";
136 return -EIO;
137 }
138
139 } else {
140 LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
141 return -EIO;
142 }
143
144 RestoreconRecursive(mPath);
145
146 // Verify that common directories are ready to roll
147 if (PrepareDir(mPath + "/app", 0771, AID_SYSTEM, AID_SYSTEM) ||
148 PrepareDir(mPath + "/user", 0711, AID_SYSTEM, AID_SYSTEM) ||
149 PrepareDir(mPath + "/user_de", 0711, AID_SYSTEM, AID_SYSTEM) ||
150 PrepareDir(mPath + "/media", 0770, AID_MEDIA_RW, AID_MEDIA_RW) ||
151 PrepareDir(mPath + "/media/0", 0770, AID_MEDIA_RW, AID_MEDIA_RW) ||
152 PrepareDir(mPath + "/local", 0751, AID_ROOT, AID_ROOT) ||
153 PrepareDir(mPath + "/local/tmp", 0771, AID_SHELL, AID_SHELL)) {
154 PLOG(ERROR) << getId() << " failed to prepare";
155 return -EIO;
156 }
157
158 // Create a new emulated volume stacked above us, it will automatically
159 // be destroyed during unmount
160 std::string mediaPath(mPath + "/media");
161 auto vol = std::shared_ptr<VolumeBase>(new EmulatedVolume(mediaPath, mRawDevice, mFsUuid));
162 addVolume(vol);
163 vol->create();
164
165 return OK;
166 }
167
doUnmount()168 status_t PrivateVolume::doUnmount() {
169 ForceUnmount(mPath);
170
171 if (TEMP_FAILURE_RETRY(rmdir(mPath.c_str()))) {
172 PLOG(ERROR) << getId() << " failed to rmdir mount point " << mPath;
173 }
174
175 return OK;
176 }
177
doFormat(const std::string & fsType)178 status_t PrivateVolume::doFormat(const std::string& fsType) {
179 std::string resolvedFsType = fsType;
180 if (fsType == "auto") {
181 // For now, assume that all MMC devices are flash-based SD cards, and
182 // give everyone else ext4 because sysfs rotational isn't reliable.
183 if ((major(mRawDevice) == kMajorBlockMmc) && f2fs::IsSupported()) {
184 resolvedFsType = "f2fs";
185 } else {
186 resolvedFsType = "ext4";
187 }
188 LOG(DEBUG) << "Resolved auto to " << resolvedFsType;
189 }
190
191 if (resolvedFsType == "ext4") {
192 // TODO: change reported mountpoint once we have better selinux support
193 if (ext4::Format(mDmDevPath, 0, "/data")) {
194 PLOG(ERROR) << getId() << " failed to format";
195 return -EIO;
196 }
197 } else if (resolvedFsType == "f2fs") {
198 if (f2fs::Format(mDmDevPath)) {
199 PLOG(ERROR) << getId() << " failed to format";
200 return -EIO;
201 }
202 } else {
203 LOG(ERROR) << getId() << " unsupported filesystem " << fsType;
204 return -EINVAL;
205 }
206
207 return OK;
208 }
209
210 } // namespace vold
211 } // namespace android
212