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 "update_engine/boot_control_android.h"
18
19 #include <base/bind.h>
20 #include <base/files/file_util.h>
21 #include <base/logging.h>
22 #include <base/strings/string_util.h>
23 #include <brillo/make_unique_ptr.h>
24 #include <brillo/message_loops/message_loop.h>
25 #include <cutils/properties.h>
26 #include <fs_mgr.h>
27
28 #include "update_engine/common/utils.h"
29
30 using std::string;
31
32 namespace {
33
34 // Open the appropriate fstab file and fallback to /fstab.device if
35 // that's what's being used.
OpenFSTab()36 static struct fstab* OpenFSTab() {
37 char propbuf[PROPERTY_VALUE_MAX];
38 struct fstab* fstab;
39
40 property_get("ro.hardware", propbuf, "");
41 string fstab_name = string("/fstab.") + propbuf;
42 fstab = fs_mgr_read_fstab(fstab_name.c_str());
43 if (fstab != nullptr)
44 return fstab;
45
46 fstab = fs_mgr_read_fstab("/fstab.device");
47 return fstab;
48 }
49
50 } // namespace
51
52
53 namespace chromeos_update_engine {
54
55 namespace boot_control {
56
57 // Factory defined in boot_control.h.
CreateBootControl()58 std::unique_ptr<BootControlInterface> CreateBootControl() {
59 std::unique_ptr<BootControlAndroid> boot_control(new BootControlAndroid());
60 if (!boot_control->Init()) {
61 return nullptr;
62 }
63 return brillo::make_unique_ptr(boot_control.release());
64 }
65
66 } // namespace boot_control
67
Init()68 bool BootControlAndroid::Init() {
69 const hw_module_t* hw_module;
70 int ret;
71
72 ret = hw_get_module(BOOT_CONTROL_HARDWARE_MODULE_ID, &hw_module);
73 if (ret != 0) {
74 LOG(ERROR) << "Error loading boot_control HAL implementation.";
75 return false;
76 }
77
78 module_ = reinterpret_cast<boot_control_module_t*>(const_cast<hw_module_t*>(hw_module));
79 module_->init(module_);
80
81 LOG(INFO) << "Loaded boot_control HAL "
82 << "'" << hw_module->name << "' "
83 << "version " << (hw_module->module_api_version>>8) << "."
84 << (hw_module->module_api_version&0xff) << " "
85 << "authored by '" << hw_module->author << "'.";
86 return true;
87 }
88
GetNumSlots() const89 unsigned int BootControlAndroid::GetNumSlots() const {
90 return module_->getNumberSlots(module_);
91 }
92
GetCurrentSlot() const93 BootControlInterface::Slot BootControlAndroid::GetCurrentSlot() const {
94 return module_->getCurrentSlot(module_);
95 }
96
GetPartitionDevice(const string & partition_name,Slot slot,string * device) const97 bool BootControlAndroid::GetPartitionDevice(const string& partition_name,
98 Slot slot,
99 string* device) const {
100 struct fstab* fstab;
101 struct fstab_rec* record;
102
103 // We can't use fs_mgr to look up |partition_name| because fstab
104 // doesn't list every slot partition (it uses the slotselect option
105 // to mask the suffix).
106 //
107 // We can however assume that there's an entry for the /misc mount
108 // point and use that to get the device file for the misc
109 // partition. This helps us locate the disk that |partition_name|
110 // resides on. From there we'll assume that a by-name scheme is used
111 // so we can just replace the trailing "misc" by the given
112 // |partition_name| and suffix corresponding to |slot|, e.g.
113 //
114 // /dev/block/platform/soc.0/7824900.sdhci/by-name/misc ->
115 // /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a
116 //
117 // If needed, it's possible to relax the by-name assumption in the
118 // future by trawling /sys/block looking for the appropriate sibling
119 // of misc and then finding an entry in /dev matching the sysfs
120 // entry.
121
122 fstab = OpenFSTab();
123 if (fstab == nullptr) {
124 LOG(ERROR) << "Error opening fstab file.";
125 return false;
126 }
127 record = fs_mgr_get_entry_for_mount_point(fstab, "/misc");
128 if (record == nullptr) {
129 LOG(ERROR) << "Error finding /misc entry in fstab file.";
130 fs_mgr_free_fstab(fstab);
131 return false;
132 }
133
134 base::FilePath misc_device = base::FilePath(record->blk_device);
135 fs_mgr_free_fstab(fstab);
136
137 if (!utils::IsSymlink(misc_device.value().c_str())) {
138 LOG(ERROR) << "Device file " << misc_device.value() << " for /misc "
139 << "is not a symlink.";
140 return false;
141 }
142
143 const char* suffix = module_->getSuffix(module_, slot);
144 if (suffix == nullptr) {
145 LOG(ERROR) << "boot_control impl returned no suffix for slot "
146 << SlotName(slot);
147 return false;
148 }
149
150 base::FilePath path = misc_device.DirName().Append(partition_name + suffix);
151 if (!base::PathExists(path)) {
152 LOG(ERROR) << "Device file " << path.value() << " does not exist.";
153 return false;
154 }
155
156 *device = path.value();
157 return true;
158 }
159
IsSlotBootable(Slot slot) const160 bool BootControlAndroid::IsSlotBootable(Slot slot) const {
161 int ret = module_->isSlotBootable(module_, slot);
162 if (ret < 0) {
163 LOG(ERROR) << "Unable to determine if slot " << SlotName(slot)
164 << " is bootable: " << strerror(-ret);
165 return false;
166 }
167 return ret == 1;
168 }
169
MarkSlotUnbootable(Slot slot)170 bool BootControlAndroid::MarkSlotUnbootable(Slot slot) {
171 int ret = module_->setSlotAsUnbootable(module_, slot);
172 if (ret < 0) {
173 LOG(ERROR) << "Unable to mark slot " << SlotName(slot)
174 << " as bootable: " << strerror(-ret);
175 return false;
176 }
177 return ret == 0;
178 }
179
SetActiveBootSlot(Slot slot)180 bool BootControlAndroid::SetActiveBootSlot(Slot slot) {
181 int ret = module_->setActiveBootSlot(module_, slot);
182 if (ret < 0) {
183 LOG(ERROR) << "Unable to set the active slot to slot " << SlotName(slot)
184 << ": " << strerror(-ret);
185 }
186 return ret == 0;
187 }
188
MarkBootSuccessfulAsync(base::Callback<void (bool)> callback)189 bool BootControlAndroid::MarkBootSuccessfulAsync(
190 base::Callback<void(bool)> callback) {
191 int ret = module_->markBootSuccessful(module_);
192 if (ret < 0) {
193 LOG(ERROR) << "Unable to mark boot successful: " << strerror(-ret);
194 }
195 return brillo::MessageLoop::current()->PostTask(
196 FROM_HERE, base::Bind(callback, ret == 0)) !=
197 brillo::MessageLoop::kTaskIdNull;
198 }
199
200 } // namespace chromeos_update_engine
201