1 /*
2  * Copyright (C) 2017 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 "ObbVolume.h"
18 #include "Devmapper.h"
19 #include "Loop.h"
20 #include "Utils.h"
21 #include "VoldUtil.h"
22 #include "fs/Vfat.h"
23 
24 #include <android-base/logging.h>
25 #include <android-base/stringprintf.h>
26 #include <cutils/fs.h>
27 #include <private/android_filesystem_config.h>
28 
29 #include <fcntl.h>
30 #include <stdlib.h>
31 #include <sys/mount.h>
32 #include <sys/stat.h>
33 #include <sys/sysmacros.h>
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 
37 using android::base::StringPrintf;
38 
39 namespace android {
40 namespace vold {
41 
42 ObbVolume::ObbVolume(int id, const std::string& sourcePath, const std::string& sourceKey,
43                      gid_t ownerGid)
44     : VolumeBase(Type::kObb) {
45     setId(StringPrintf("obb:%d", id));
46     mSourcePath = sourcePath;
47     mSourceKey = sourceKey;
48     mOwnerGid = ownerGid;
49 }
50 
51 ObbVolume::~ObbVolume() {}
52 
53 status_t ObbVolume::doCreate() {
54     if (Loop::create(mSourcePath, mLoopPath)) {
55         PLOG(ERROR) << getId() << " failed to create loop";
56         return -1;
57     }
58 
59     if (!mSourceKey.empty()) {
60         uint64_t nr_sec = 0;
61         if (GetBlockDev512Sectors(mLoopPath, &nr_sec) != OK) {
62             PLOG(ERROR) << getId() << " failed to get loop size";
63             return -1;
64         }
65 
66         char tmp[PATH_MAX];
67         if (Devmapper::create(getId().c_str(), mLoopPath.c_str(), mSourceKey.c_str(), nr_sec, tmp,
68                               PATH_MAX)) {
69             PLOG(ERROR) << getId() << " failed to create dm";
70             return -1;
71         }
72         mDmPath = tmp;
73         mMountPath = mDmPath;
74     } else {
75         mMountPath = mLoopPath;
76     }
77     return OK;
78 }
79 
80 status_t ObbVolume::doDestroy() {
81     if (!mDmPath.empty() && Devmapper::destroy(getId().c_str())) {
82         PLOG(WARNING) << getId() << " failed to destroy dm";
83     }
84     if (!mLoopPath.empty() && Loop::destroyByDevice(mLoopPath.c_str())) {
85         PLOG(WARNING) << getId() << " failed to destroy loop";
86     }
87     mDmPath.clear();
88     mLoopPath.clear();
89     return OK;
90 }
91 
92 status_t ObbVolume::doMount() {
93     auto path = StringPrintf("/mnt/obb/%s", getId().c_str());
94     setPath(path);
95 
96     if (fs_prepare_dir(path.c_str(), 0700, AID_ROOT, AID_ROOT)) {
97         PLOG(ERROR) << getId() << " failed to create mount point";
98         return -1;
99     }
100     // clang-format off
101     if (android::vold::vfat::Mount(mMountPath, path, true, false, true,
102                                    0, mOwnerGid, 0227, false)) {
103         // clang-format on
104         PLOG(ERROR) << getId() << " failed to mount";
105         return -1;
106     }
107     return OK;
108 }
109 
110 status_t ObbVolume::doUnmount() {
111     auto path = getPath();
112 
113     KillProcessesUsingPath(path);
114     ForceUnmount(path);
115     rmdir(path.c_str());
116 
117     return OK;
118 }
119 
120 }  // namespace vold
121 }  // namespace android
122