1 /*
2  * Copyright (C) 2019 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 "install/wipe_data.h"
18 
19 #include <string.h>
20 
21 #include <functional>
22 #include <vector>
23 
24 #include <android-base/file.h>
25 #include <android-base/logging.h>
26 #include <android-base/stringprintf.h>
27 
28 #include "bootloader_message/bootloader_message.h"
29 #include "install/snapshot_utils.h"
30 #include "recovery_ui/ui.h"
31 #include "recovery_utils/logging.h"
32 #include "recovery_utils/roots.h"
33 
34 constexpr const char* CACHE_ROOT = "/cache";
35 constexpr const char* DATA_ROOT = "/data";
36 constexpr const char* METADATA_ROOT = "/metadata";
37 
EraseVolume(const char * volume,RecoveryUI * ui,std::string_view new_fstype)38 static bool EraseVolume(const char* volume, RecoveryUI* ui, std::string_view new_fstype) {
39   LOG(INFO) << "Erasing volume " << volume << " with new filesystem type " << new_fstype;
40   bool is_cache = (strcmp(volume, CACHE_ROOT) == 0);
41 
42   std::vector<saved_log_file> log_files;
43   if (is_cache) {
44     // If we're reformatting /cache, we load any past logs (i.e. "/cache/recovery/last_*") and the
45     // current log ("/cache/recovery/log") into memory, so we can restore them after the reformat.
46     log_files = ReadLogFilesToMemory();
47   }
48 
49   ui->Print("Formatting %s...\n", volume);
50 
51   ensure_path_unmounted(volume);
52 
53   int result = format_volume(volume, "", new_fstype);
54 
55   if (is_cache) {
56     RestoreLogFilesAfterFormat(log_files);
57   }
58 
59   return (result == 0);
60 }
61 
WipeCache(RecoveryUI * ui,const std::function<bool ()> & confirm_func,std::string_view new_fstype)62 bool WipeCache(RecoveryUI* ui, const std::function<bool()>& confirm_func,
63                std::string_view new_fstype) {
64   bool has_cache = volume_for_mount_point("/cache") != nullptr;
65   if (!has_cache) {
66     ui->Print("No /cache partition found.\n");
67     return false;
68   }
69 
70   if (confirm_func && !confirm_func()) {
71     return false;
72   }
73 
74   ui->Print("\n-- Wiping cache...\n");
75   ui->SetBackground(RecoveryUI::ERASING);
76   ui->SetProgressType(RecoveryUI::INDETERMINATE);
77 
78   bool success = EraseVolume("/cache", ui, new_fstype);
79   ui->Print("Cache wipe %s.\n", success ? "complete" : "failed");
80   return success;
81 }
82 
WipeData(Device * device,bool keep_memtag_mode,std::string_view data_fstype)83 bool WipeData(Device* device, bool keep_memtag_mode, std::string_view data_fstype) {
84   RecoveryUI* ui = device->GetUI();
85   ui->Print("\n-- Wiping data %.*s...\n", static_cast<int>(data_fstype.size()), data_fstype.data());
86   ui->SetBackground(RecoveryUI::ERASING);
87   ui->SetProgressType(RecoveryUI::INDETERMINATE);
88 
89   if (!FinishPendingSnapshotMerges(device)) {
90     ui->Print("Unable to check update status or complete merge, cannot wipe partitions.\n");
91     return false;
92   }
93 
94   bool success = device->PreWipeData();
95   if (success) {
96     success &= EraseVolume(DATA_ROOT, ui, data_fstype);
97     bool has_cache = volume_for_mount_point("/cache") != nullptr;
98     if (has_cache) {
99       success &= EraseVolume(CACHE_ROOT, ui, data_fstype);
100     }
101     if (volume_for_mount_point(METADATA_ROOT) != nullptr) {
102       success &= EraseVolume(METADATA_ROOT, ui, data_fstype);
103     }
104   }
105   if (keep_memtag_mode) {
106     ui->Print("NOT resetting memtag message as per request...\n");
107   } else {
108     ui->Print("Resetting memtag message...\n");
109     std::string err;
110     if (!WriteMiscMemtagMessage({}, &err)) {
111       ui->Print("Failed to reset memtag message: %s\n", err.c_str());
112       success = false;
113     }
114   }
115   if (success) {
116     success &= device->PostWipeData();
117   }
118   ui->Print("Data wipe %s.\n", success ? "complete" : "failed");
119   return success;
120 }
121