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 <stdio.h>
20 #include <string.h>
21 #include <sys/stat.h>
22 
23 #include <functional>
24 #include <vector>
25 
26 #include <android-base/file.h>
27 #include <android-base/logging.h>
28 #include <android-base/stringprintf.h>
29 
30 #include "install/snapshot_utils.h"
31 #include "otautil/dirutil.h"
32 #include "recovery_ui/ui.h"
33 #include "recovery_utils/logging.h"
34 #include "recovery_utils/roots.h"
35 
36 constexpr const char* CACHE_ROOT = "/cache";
37 constexpr const char* DATA_ROOT = "/data";
38 constexpr const char* METADATA_ROOT = "/metadata";
39 
EraseVolume(const char * volume,RecoveryUI * ui,bool convert_fbe)40 static bool EraseVolume(const char* volume, RecoveryUI* ui, bool convert_fbe) {
41   bool is_cache = (strcmp(volume, CACHE_ROOT) == 0);
42   bool is_data = (strcmp(volume, DATA_ROOT) == 0);
43 
44   ui->SetBackground(RecoveryUI::ERASING);
45   ui->SetProgressType(RecoveryUI::INDETERMINATE);
46 
47   std::vector<saved_log_file> log_files;
48   if (is_cache) {
49     // If we're reformatting /cache, we load any past logs (i.e. "/cache/recovery/last_*") and the
50     // current log ("/cache/recovery/log") into memory, so we can restore them after the reformat.
51     log_files = ReadLogFilesToMemory();
52   }
53 
54   ui->Print("Formatting %s...\n", volume);
55 
56   ensure_path_unmounted(volume);
57 
58   int result;
59   if (is_data && convert_fbe) {
60     constexpr const char* CONVERT_FBE_DIR = "/tmp/convert_fbe";
61     constexpr const char* CONVERT_FBE_FILE = "/tmp/convert_fbe/convert_fbe";
62     // Create convert_fbe breadcrumb file to signal init to convert to file based encryption, not
63     // full disk encryption.
64     if (mkdir(CONVERT_FBE_DIR, 0700) != 0) {
65       PLOG(ERROR) << "Failed to mkdir " << CONVERT_FBE_DIR;
66       return false;
67     }
68     FILE* f = fopen(CONVERT_FBE_FILE, "wbe");
69     if (!f) {
70       PLOG(ERROR) << "Failed to convert to file encryption";
71       return false;
72     }
73     fclose(f);
74     result = format_volume(volume, CONVERT_FBE_DIR);
75     remove(CONVERT_FBE_FILE);
76     rmdir(CONVERT_FBE_DIR);
77   } else {
78     result = format_volume(volume);
79   }
80 
81   if (is_cache) {
82     RestoreLogFilesAfterFormat(log_files);
83   }
84 
85   return (result == 0);
86 }
87 
WipeCache(RecoveryUI * ui,const std::function<bool ()> & confirm_func)88 bool WipeCache(RecoveryUI* ui, const std::function<bool()>& confirm_func) {
89   bool has_cache = volume_for_mount_point("/cache") != nullptr;
90   if (!has_cache) {
91     ui->Print("No /cache partition found.\n");
92     return false;
93   }
94 
95   if (confirm_func && !confirm_func()) {
96     return false;
97   }
98 
99   ui->Print("\n-- Wiping cache...\n");
100   bool success = EraseVolume("/cache", ui, false);
101   ui->Print("Cache wipe %s.\n", success ? "complete" : "failed");
102   return success;
103 }
104 
WipeData(Device * device,bool convert_fbe)105 bool WipeData(Device* device, bool convert_fbe) {
106   RecoveryUI* ui = device->GetUI();
107   ui->Print("\n-- Wiping data...\n");
108 
109   if (!FinishPendingSnapshotMerges(device)) {
110     ui->Print("Unable to check update status or complete merge, cannot wipe partitions.\n");
111     return false;
112   }
113 
114   bool success = device->PreWipeData();
115   if (success) {
116     success &= EraseVolume(DATA_ROOT, ui, convert_fbe);
117     bool has_cache = volume_for_mount_point("/cache") != nullptr;
118     if (has_cache) {
119       success &= EraseVolume(CACHE_ROOT, ui, false);
120     }
121     if (volume_for_mount_point(METADATA_ROOT) != nullptr) {
122       success &= EraseVolume(METADATA_ROOT, ui, false);
123     }
124   }
125   if (success) {
126     success &= device->PostWipeData();
127   }
128   ui->Print("Data wipe %s.\n", success ? "complete" : "failed");
129   return success;
130 }
131