1 /*
2  * Copyright (C) 2018 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 "fastboot/Fastboot.h"
18 
19 #include <android-base/file.h>
20 #include <android-base/logging.h>
21 #include <android-base/strings.h>
22 #include <android-base/unique_fd.h>
23 #include <dlfcn.h>
24 
25 #include <map>
26 #include <string>
27 #include <unordered_map>
28 #include <vector>
29 
30 // FS headers
31 #include <ext4_utils/wipe.h>
32 #include <fs_mgr.h>
33 #include <fs_mgr/roots.h>
34 
35 // Nugget headers
36 #include <app_nugget.h>
37 #include <nos/NuggetClient.h>
38 #include <nos/debug.h>
39 
40 namespace android {
41 namespace hardware {
42 namespace fastboot {
43 namespace V1_1 {
44 namespace implementation {
45 
46 constexpr const char* BRIGHTNESS_FILE = "/sys/class/backlight/panel0-backlight/brightness";
47 constexpr int DISPLAY_BRIGHTNESS_DIM_THRESHOLD = 20;
48 
49 using  OEMCommandHandler = std::function<Result(const std::vector<std::string>&)>;
50 
getPartitionType(const::android::hardware::hidl_string &,getPartitionType_cb _hidl_cb)51 Return<void> Fastboot::getPartitionType(const ::android::hardware::hidl_string& /* partitionName */,
52                                   getPartitionType_cb _hidl_cb) {
53     // For bluecross devices, all partitions need to return raw.
54     _hidl_cb(FileSystemType::RAW, { Status::SUCCESS, "" });
55     return Void();
56 }
57 
getVariant(getVariant_cb _hidl_cb)58 Return<void> Fastboot::getVariant(getVariant_cb _hidl_cb) {
59     _hidl_cb("MSM USF", {Status::SUCCESS, "" });
60     return Void();
61 }
62 
getOffModeChargeState(getOffModeChargeState_cb _hidl_cb)63 Return<void> Fastboot::getOffModeChargeState(getOffModeChargeState_cb _hidl_cb) {
64     constexpr const char* kDevinfoPath = "/dev/block/by-name/devinfo";
65     constexpr int kDevInfoOffModeChargeOffset = 15;
66 
67     uint8_t off_mode_charge_status = 0;
68     android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(kDevinfoPath,
69                                                         O_RDONLY | O_BINARY)));
70     if (!android::base::ReadFullyAtOffset(fd, &off_mode_charge_status, 1 /* byte count */,
71                                           kDevInfoOffModeChargeOffset)) {
72         _hidl_cb(false,
73                  { Status::FAILURE_UNKNOWN, "Unable to read off-mode-charge state" });
74     } else {
75         _hidl_cb(off_mode_charge_status != 0, { Status::SUCCESS, "" });
76     }
77 
78     return Void();
79 }
80 
getBatteryVoltageFlashingThreshold(getBatteryVoltageFlashingThreshold_cb _hidl_cb)81 Return<void> Fastboot::getBatteryVoltageFlashingThreshold(
82         getBatteryVoltageFlashingThreshold_cb _hidl_cb) {
83     constexpr int kMinVoltageForFlashing = 3500;
84     _hidl_cb(kMinVoltageForFlashing, { Status::SUCCESS, "" });
85     return Void();
86 }
87 
SetBrightnessLevel(const std::vector<std::string> & args)88 Result SetBrightnessLevel(const std::vector<std::string>& args) {
89     if (!args.size()) {
90         return { Status::INVALID_ARGUMENT, "Brightness level unspecified" };
91     }
92 
93     auto level = std::stoi(args[0]);
94 
95     if (level < 0 || level > 100)  {
96         return { Status::INVALID_ARGUMENT, "Brighness level must be between 0 and 100" };
97     }
98 
99     // Avoid screen being dimmed too much.
100     if (level < DISPLAY_BRIGHTNESS_DIM_THRESHOLD) {
101         level = DISPLAY_BRIGHTNESS_DIM_THRESHOLD;
102     }
103 
104     if (android::base::WriteStringToFile(std::to_string(level), BRIGHTNESS_FILE)) {
105             return { Status::SUCCESS, "" };
106     }
107 
108     return { Status::FAILURE_UNKNOWN, "Unable to set display brightness" };
109 }
110 
doOemCommand(const::android::hardware::hidl_string & oemCmdArgs,doOemCommand_cb _hidl_cb)111 Return<void> Fastboot::doOemCommand(const ::android::hardware::hidl_string& oemCmdArgs,
112                           doOemCommand_cb _hidl_cb) {
113     const std::unordered_map<std::string, OEMCommandHandler> kOEMCmdMap = {
114         {FB_OEM_SET_BRIGHTNESS, SetBrightnessLevel},
115     };
116 
117     auto args = android::base::Split(oemCmdArgs, " ");
118     if (args.size() < 2) {
119         _hidl_cb({ Status::INVALID_ARGUMENT, "Invalid OEM command" });
120         return Void();
121     }
122 
123     // args[0] will be "oem", args[1] will be the command name
124     auto cmd_handler = kOEMCmdMap.find(args[1]);
125     if (cmd_handler != kOEMCmdMap.end()) {
126         _hidl_cb(cmd_handler->second(std::vector<std::string>(args.begin() + 2, args.end())));
127     } else {
128         _hidl_cb({ Status::FAILURE_UNKNOWN, "Unknown OEM command" });
129     }
130 
131     return Void();
132 }
133 
134 static android::fs_mgr::Fstab fstab;
135 enum WipeVolumeStatus {
136     WIPE_OK = 0,
137     VOL_FSTAB,
138     VOL_UNKNOWN,
139     VOL_MOUNTED,
140     VOL_BLK_DEV_OPEN,
141     WIPE_ERROR_MAX = 0xffffffff,
142 };
143 std::map<enum WipeVolumeStatus, std::string> wipe_vol_ret_msg{
144         {WIPE_OK, ""},
145         {VOL_FSTAB, "Unknown FS table"},
146         {VOL_UNKNOWN, "Unknown volume"},
147         {VOL_MOUNTED, "Fail to unmount volume"},
148         {VOL_BLK_DEV_OPEN, "Fail to open block device"},
149         {WIPE_ERROR_MAX, "Unknown wipe error"}};
150 
wipe_volume(const std::string & volume)151 enum WipeVolumeStatus wipe_volume(const std::string &volume) {
152     if (!android::fs_mgr::ReadDefaultFstab(&fstab)) {
153         return VOL_FSTAB;
154     }
155     const fs_mgr::FstabEntry *v = android::fs_mgr::GetEntryForPath(&fstab, volume);
156     if (v == nullptr) {
157         return VOL_UNKNOWN;
158     }
159     if (android::fs_mgr::EnsurePathUnmounted(&fstab, volume) != true) {
160         return VOL_MOUNTED;
161     }
162 
163     int fd = open(v->blk_device.c_str(), O_WRONLY | O_CREAT, 0644);
164     if (fd == -1) {
165         return VOL_BLK_DEV_OPEN;
166     }
167     wipe_block_device(fd, get_block_device_size(fd));
168     close(fd);
169 
170     return WIPE_OK;
171 }
172 
173 // Attempt to reuse a WipeKeys function that might be found in the recovery
174 // library in order to clear any digital car keys on the secure element.
WipeDigitalCarKeys(void)175 bool WipeDigitalCarKeys(void) {
176     static constexpr const char *kDefaultLibRecoveryUIExt = "librecovery_ui_ext.so";
177     void *librecovery_ui_ext = dlopen(kDefaultLibRecoveryUIExt, RTLD_NOW);
178     if (librecovery_ui_ext == nullptr) {
179         // Dynamic library not found. Returning true since this likely
180         // means target does not support DCK.
181         return true;
182     }
183 
184     bool *(*WipeKeysFunc)(void *const);
185     reinterpret_cast<void *&>(WipeKeysFunc) = dlsym(librecovery_ui_ext, "WipeKeys");
186     if (WipeKeysFunc == nullptr) {
187         // No WipeKeys implementation found. Returning true since this likely
188         // means target does not support DCK.
189         return true;
190     }
191 
192     return (*WipeKeysFunc)(nullptr);
193 }
194 
doOemSpecificErase(V1_1::IFastboot::doOemSpecificErase_cb _hidl_cb)195 Return<void> Fastboot::doOemSpecificErase(V1_1::IFastboot::doOemSpecificErase_cb _hidl_cb) {
196     // Erase metadata partition along with userdata partition.
197     // Keep erasing Titan M even if failing on this case.
198     auto wipe_status = wipe_volume("/metadata");
199 
200     bool dck_wipe_success = WipeDigitalCarKeys();
201 
202     // Connect to Titan M
203     ::nos::NuggetClient client;
204     client.Open();
205     if (!client.IsOpen()) {
206         _hidl_cb({ Status::FAILURE_UNKNOWN, "open Titan M fail" });
207         return Void();
208     }
209 
210     // Tell Titan M to wipe user data
211     const uint32_t magicValue = htole32(ERASE_CONFIRMATION);
212     std::vector<uint8_t> magic(sizeof(magicValue));
213     memcpy(magic.data(), &magicValue, sizeof(magicValue));
214     const uint8_t retry_count = 5;
215     uint32_t nugget_status;
216     for (uint8_t i = 0; i < retry_count; i++) {
217         nugget_status = client.CallApp(APP_ID_NUGGET, NUGGET_PARAM_NUKE_FROM_ORBIT, magic, nullptr);
218         if (nugget_status == APP_SUCCESS && wipe_status == WIPE_OK && dck_wipe_success) {
219             _hidl_cb({Status::SUCCESS, wipe_vol_ret_msg[wipe_status]});
220             return Void();
221         }
222     }
223 
224     // Return exactly what happened
225     if (nugget_status != APP_SUCCESS && wipe_status != WIPE_OK && !dck_wipe_success) {
226         _hidl_cb({Status::FAILURE_UNKNOWN, "Fail on wiping metadata, Titan M user data, and DCK"});
227     } else if (nugget_status != APP_SUCCESS && wipe_status != WIPE_OK) {
228         _hidl_cb({Status::FAILURE_UNKNOWN, "Fail on wiping metadata and Titan M user data"});
229     } else if (nugget_status != APP_SUCCESS && !dck_wipe_success) {
230         _hidl_cb({Status::FAILURE_UNKNOWN, "Titan M user data and DCK wipe failed"});
231     } else if (nugget_status != APP_SUCCESS) {
232         _hidl_cb({Status::FAILURE_UNKNOWN, "Titan M user data wipe failed"});
233     } else if (wipe_status != WIPE_OK && !dck_wipe_success) {
234         _hidl_cb({Status::FAILURE_UNKNOWN, "Fail on wiping metadata and DCK"});
235     } else if (!dck_wipe_success) {
236         _hidl_cb({Status::FAILURE_UNKNOWN, "DCK wipe failed"});
237     } else {
238         if (wipe_vol_ret_msg.find(wipe_status) != wipe_vol_ret_msg.end())
239             _hidl_cb({Status::FAILURE_UNKNOWN, wipe_vol_ret_msg[wipe_status]});
240         else  // Should not reach here, but handle it anyway
241             _hidl_cb({Status::FAILURE_UNKNOWN, "Unknown failure"});
242     }
243 
244     return Void();
245 }
246 
Fastboot()247 Fastboot::Fastboot() {}
248 
249 // Methods from ::android::hidl::base::V1_0::IBase follow.
250 
HIDL_FETCH_IFastboot(const char *)251 extern "C" IFastboot* HIDL_FETCH_IFastboot(const char* /* name */) {
252     return new Fastboot();
253 }
254 
255 }  // namespace implementation
256 }  // namespace V1_1
257 }  // namespace fastboot
258 }  // namespace hardware
259 }  // namespace android
260