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_recovery.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/message_loops/message_loop.h>
24
25 #include "update_engine/common/utils.h"
26 #include "update_engine/utils_android.h"
27
28 using std::string;
29
30 #ifndef _UE_SIDELOAD
31 #error "BootControlRecovery should only be used for update_engine_sideload."
32 #endif
33
34 // When called from update_engine_sideload, we don't attempt to dynamically load
35 // the right boot_control HAL, instead we use the only HAL statically linked in
36 // via the PRODUCT_STATIC_BOOT_CONTROL_HAL make variable and access the module
37 // struct directly.
38 extern const hw_module_t HAL_MODULE_INFO_SYM;
39
40 namespace chromeos_update_engine {
41
42 namespace boot_control {
43
44 // Factory defined in boot_control.h.
CreateBootControl()45 std::unique_ptr<BootControlInterface> CreateBootControl() {
46 std::unique_ptr<BootControlRecovery> boot_control(new BootControlRecovery());
47 if (!boot_control->Init()) {
48 return nullptr;
49 }
50 return std::move(boot_control);
51 }
52
53 } // namespace boot_control
54
Init()55 bool BootControlRecovery::Init() {
56 const hw_module_t* hw_module;
57 int ret;
58
59 // For update_engine_sideload, we simulate the hw_get_module() by accessing it
60 // from the current process directly.
61 hw_module = &HAL_MODULE_INFO_SYM;
62 ret = 0;
63 if (!hw_module ||
64 strcmp(BOOT_CONTROL_HARDWARE_MODULE_ID, hw_module->id) != 0) {
65 ret = -EINVAL;
66 }
67 if (ret != 0) {
68 LOG(ERROR) << "Error loading boot_control HAL implementation.";
69 return false;
70 }
71
72 module_ = reinterpret_cast<boot_control_module_t*>(
73 const_cast<hw_module_t*>(hw_module));
74 module_->init(module_);
75
76 LOG(INFO) << "Loaded boot_control HAL "
77 << "'" << hw_module->name << "' "
78 << "version " << (hw_module->module_api_version >> 8) << "."
79 << (hw_module->module_api_version & 0xff) << " "
80 << "authored by '" << hw_module->author << "'.";
81 return true;
82 }
83
GetNumSlots() const84 unsigned int BootControlRecovery::GetNumSlots() const {
85 return module_->getNumberSlots(module_);
86 }
87
GetCurrentSlot() const88 BootControlInterface::Slot BootControlRecovery::GetCurrentSlot() const {
89 return module_->getCurrentSlot(module_);
90 }
91
GetPartitionDevice(const string & partition_name,Slot slot,string * device) const92 bool BootControlRecovery::GetPartitionDevice(const string& partition_name,
93 Slot slot,
94 string* device) const {
95 // We can't use fs_mgr to look up |partition_name| because fstab
96 // doesn't list every slot partition (it uses the slotselect option
97 // to mask the suffix).
98 //
99 // We can however assume that there's an entry for the /misc mount
100 // point and use that to get the device file for the misc
101 // partition. This helps us locate the disk that |partition_name|
102 // resides on. From there we'll assume that a by-name scheme is used
103 // so we can just replace the trailing "misc" by the given
104 // |partition_name| and suffix corresponding to |slot|, e.g.
105 //
106 // /dev/block/platform/soc.0/7824900.sdhci/by-name/misc ->
107 // /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a
108 //
109 // If needed, it's possible to relax the by-name assumption in the
110 // future by trawling /sys/block looking for the appropriate sibling
111 // of misc and then finding an entry in /dev matching the sysfs
112 // entry.
113
114 base::FilePath misc_device;
115 if (!utils::DeviceForMountPoint("/misc", &misc_device))
116 return false;
117
118 if (!utils::IsSymlink(misc_device.value().c_str())) {
119 LOG(ERROR) << "Device file " << misc_device.value() << " for /misc "
120 << "is not a symlink.";
121 return false;
122 }
123
124 const char* suffix = module_->getSuffix(module_, slot);
125 if (suffix == nullptr) {
126 LOG(ERROR) << "boot_control impl returned no suffix for slot "
127 << SlotName(slot);
128 return false;
129 }
130
131 base::FilePath path = misc_device.DirName().Append(partition_name + suffix);
132 if (!base::PathExists(path)) {
133 LOG(ERROR) << "Device file " << path.value() << " does not exist.";
134 return false;
135 }
136
137 *device = path.value();
138 return true;
139 }
140
IsSlotBootable(Slot slot) const141 bool BootControlRecovery::IsSlotBootable(Slot slot) const {
142 int ret = module_->isSlotBootable(module_, slot);
143 if (ret < 0) {
144 LOG(ERROR) << "Unable to determine if slot " << SlotName(slot)
145 << " is bootable: " << strerror(-ret);
146 return false;
147 }
148 return ret == 1;
149 }
150
MarkSlotUnbootable(Slot slot)151 bool BootControlRecovery::MarkSlotUnbootable(Slot slot) {
152 int ret = module_->setSlotAsUnbootable(module_, slot);
153 if (ret < 0) {
154 LOG(ERROR) << "Unable to mark slot " << SlotName(slot)
155 << " as bootable: " << strerror(-ret);
156 return false;
157 }
158 return ret == 0;
159 }
160
SetActiveBootSlot(Slot slot)161 bool BootControlRecovery::SetActiveBootSlot(Slot slot) {
162 int ret = module_->setActiveBootSlot(module_, slot);
163 if (ret < 0) {
164 LOG(ERROR) << "Unable to set the active slot to slot " << SlotName(slot)
165 << ": " << strerror(-ret);
166 }
167 return ret == 0;
168 }
169
MarkBootSuccessfulAsync(base::Callback<void (bool)> callback)170 bool BootControlRecovery::MarkBootSuccessfulAsync(
171 base::Callback<void(bool)> callback) {
172 int ret = module_->markBootSuccessful(module_);
173 if (ret < 0) {
174 LOG(ERROR) << "Unable to mark boot successful: " << strerror(-ret);
175 }
176 return brillo::MessageLoop::current()->PostTask(
177 FROM_HERE, base::Bind(callback, ret == 0)) !=
178 brillo::MessageLoop::kTaskIdNull;
179 }
180
181 } // namespace chromeos_update_engine
182