1 /*
2  * Copyright (C) 2007 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 "recovery_utils/roots.h"
18 
19 #include <fcntl.h>
20 #include <stdint.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 #include <sys/wait.h>
26 #include <unistd.h>
27 
28 #include <iostream>
29 #include <string>
30 #include <vector>
31 
32 #include <android-base/logging.h>
33 #include <android-base/properties.h>
34 #include <android-base/stringprintf.h>
35 #include <android-base/unique_fd.h>
36 #include <cryptfs.h>
37 #include <ext4_utils/wipe.h>
38 #include <fs_mgr.h>
39 #include <fs_mgr/roots.h>
40 
41 #include "otautil/sysutil.h"
42 
43 using android::fs_mgr::Fstab;
44 using android::fs_mgr::FstabEntry;
45 using android::fs_mgr::ReadDefaultFstab;
46 
47 static Fstab fstab;
48 
49 constexpr const char* CACHE_ROOT = "/cache";
50 
load_volume_table()51 void load_volume_table() {
52   if (!ReadDefaultFstab(&fstab)) {
53     LOG(ERROR) << "Failed to read default fstab";
54     return;
55   }
56 
57   fstab.emplace_back(FstabEntry{
58       .blk_device = "ramdisk",
59       .mount_point = "/tmp",
60       .fs_type = "ramdisk",
61       .length = 0,
62   });
63 
64   std::cout << "recovery filesystem table" << std::endl << "=========================" << std::endl;
65   for (size_t i = 0; i < fstab.size(); ++i) {
66     const auto& entry = fstab[i];
67     std::cout << "  " << i << " " << entry.mount_point << " "
68               << " " << entry.fs_type << " " << entry.blk_device << " " << entry.length
69               << std::endl;
70   }
71   std::cout << std::endl;
72 }
73 
volume_for_mount_point(const std::string & mount_point)74 Volume* volume_for_mount_point(const std::string& mount_point) {
75   return android::fs_mgr::GetEntryForMountPoint(&fstab, mount_point);
76 }
77 
78 // Mount the volume specified by path at the given mount_point.
ensure_path_mounted_at(const std::string & path,const std::string & mount_point)79 int ensure_path_mounted_at(const std::string& path, const std::string& mount_point) {
80   return android::fs_mgr::EnsurePathMounted(&fstab, path, mount_point) ? 0 : -1;
81 }
82 
ensure_path_mounted(const std::string & path)83 int ensure_path_mounted(const std::string& path) {
84   // Mount at the default mount point.
85   return android::fs_mgr::EnsurePathMounted(&fstab, path) ? 0 : -1;
86 }
87 
ensure_path_unmounted(const std::string & path)88 int ensure_path_unmounted(const std::string& path) {
89   return android::fs_mgr::EnsurePathUnmounted(&fstab, path) ? 0 : -1;
90 }
91 
exec_cmd(const std::vector<std::string> & args)92 static int exec_cmd(const std::vector<std::string>& args) {
93   CHECK(!args.empty());
94   auto argv = StringVectorToNullTerminatedArray(args);
95 
96   pid_t child;
97   if ((child = fork()) == 0) {
98     execv(argv[0], argv.data());
99     _exit(EXIT_FAILURE);
100   }
101 
102   int status;
103   waitpid(child, &status, 0);
104   if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
105     LOG(ERROR) << args[0] << " failed with status " << WEXITSTATUS(status);
106   }
107   return WEXITSTATUS(status);
108 }
109 
get_file_size(int fd,uint64_t reserve_len)110 static int64_t get_file_size(int fd, uint64_t reserve_len) {
111   struct stat buf;
112   int ret = fstat(fd, &buf);
113   if (ret) return 0;
114 
115   int64_t computed_size;
116   if (S_ISREG(buf.st_mode)) {
117     computed_size = buf.st_size - reserve_len;
118   } else if (S_ISBLK(buf.st_mode)) {
119     uint64_t block_device_size = get_block_device_size(fd);
120     if (block_device_size < reserve_len ||
121         block_device_size > std::numeric_limits<int64_t>::max()) {
122       computed_size = 0;
123     } else {
124       computed_size = block_device_size - reserve_len;
125     }
126   } else {
127     computed_size = 0;
128   }
129 
130   return computed_size;
131 }
132 
format_volume(const std::string & volume,const std::string & directory)133 int format_volume(const std::string& volume, const std::string& directory) {
134   const FstabEntry* v = android::fs_mgr::GetEntryForPath(&fstab, volume);
135   if (v == nullptr) {
136     LOG(ERROR) << "unknown volume \"" << volume << "\"";
137     return -1;
138   }
139   if (v->fs_type == "ramdisk") {
140     LOG(ERROR) << "can't format_volume \"" << volume << "\"";
141     return -1;
142   }
143   if (v->mount_point != volume) {
144     LOG(ERROR) << "can't give path \"" << volume << "\" to format_volume";
145     return -1;
146   }
147   if (ensure_path_unmounted(volume) != 0) {
148     LOG(ERROR) << "format_volume: Failed to unmount \"" << v->mount_point << "\"";
149     return -1;
150   }
151   if (v->fs_type != "ext4" && v->fs_type != "f2fs") {
152     LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
153     return -1;
154   }
155 
156   bool needs_casefold = false;
157   bool needs_projid = false;
158 
159   if (volume == "/data") {
160     needs_casefold = android::base::GetBoolProperty("external_storage.casefold.enabled", false);
161     needs_projid = android::base::GetBoolProperty("external_storage.projid.enabled", false);
162   }
163 
164   // If there's a key_loc that looks like a path, it should be a block device for storing encryption
165   // metadata. Wipe it too.
166   if (!v->key_loc.empty() && v->key_loc[0] == '/') {
167     LOG(INFO) << "Wiping " << v->key_loc;
168     int fd = open(v->key_loc.c_str(), O_WRONLY | O_CREAT, 0644);
169     if (fd == -1) {
170       PLOG(ERROR) << "format_volume: Failed to open " << v->key_loc;
171       return -1;
172     }
173     wipe_block_device(fd, get_file_size(fd));
174     close(fd);
175   }
176 
177   int64_t length = 0;
178   if (v->length > 0) {
179     length = v->length;
180   } else if (v->length < 0 || v->key_loc == "footer") {
181     android::base::unique_fd fd(open(v->blk_device.c_str(), O_RDONLY));
182     if (fd == -1) {
183       PLOG(ERROR) << "format_volume: failed to open " << v->blk_device;
184       return -1;
185     }
186     length = get_file_size(fd.get(), v->length ? -v->length : CRYPT_FOOTER_OFFSET);
187     if (length <= 0) {
188       LOG(ERROR) << "get_file_size: invalid size " << length << " for " << v->blk_device;
189       return -1;
190     }
191   }
192 
193   if (v->fs_type == "ext4") {
194     static constexpr int kBlockSize = 4096;
195     std::vector<std::string> mke2fs_args = {
196       "/system/bin/mke2fs", "-F", "-t", "ext4", "-b", std::to_string(kBlockSize),
197     };
198 
199     // Project ID's require wider inodes. The Quotas themselves are enabled by tune2fs on boot.
200     if (needs_projid) {
201       mke2fs_args.push_back("-I");
202       mke2fs_args.push_back("512");
203     }
204 
205     if (v->fs_mgr_flags.ext_meta_csum) {
206       mke2fs_args.push_back("-O");
207       mke2fs_args.push_back("metadata_csum");
208       mke2fs_args.push_back("-O");
209       mke2fs_args.push_back("64bit");
210       mke2fs_args.push_back("-O");
211       mke2fs_args.push_back("extent");
212     }
213 
214     int raid_stride = v->logical_blk_size / kBlockSize;
215     int raid_stripe_width = v->erase_blk_size / kBlockSize;
216     // stride should be the max of 8KB and logical block size
217     if (v->logical_blk_size != 0 && v->logical_blk_size < 8192) {
218       raid_stride = 8192 / kBlockSize;
219     }
220     if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
221       mke2fs_args.push_back("-E");
222       mke2fs_args.push_back(
223           android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride, raid_stripe_width));
224     }
225     mke2fs_args.push_back(v->blk_device);
226     if (length != 0) {
227       mke2fs_args.push_back(std::to_string(length / kBlockSize));
228     }
229 
230     int result = exec_cmd(mke2fs_args);
231     if (result == 0 && !directory.empty()) {
232       std::vector<std::string> e2fsdroid_args = {
233         "/system/bin/e2fsdroid", "-e", "-f", directory, "-a", volume, v->blk_device,
234       };
235       result = exec_cmd(e2fsdroid_args);
236     }
237 
238     if (result != 0) {
239       PLOG(ERROR) << "format_volume: Failed to make ext4 on " << v->blk_device;
240       return -1;
241     }
242     return 0;
243   }
244 
245   // Has to be f2fs because we checked earlier.
246   static constexpr int kSectorSize = 4096;
247   std::vector<std::string> make_f2fs_cmd = {
248     "/system/bin/make_f2fs",
249     "-g",
250     "android",
251   };
252   if (needs_projid) {
253     make_f2fs_cmd.push_back("-O");
254     make_f2fs_cmd.push_back("project_quota,extra_attr");
255   }
256   if (needs_casefold) {
257     make_f2fs_cmd.push_back("-O");
258     make_f2fs_cmd.push_back("casefold");
259     make_f2fs_cmd.push_back("-C");
260     make_f2fs_cmd.push_back("utf8");
261   }
262   if (v->fs_mgr_flags.fs_compress) {
263     make_f2fs_cmd.push_back("-O");
264     make_f2fs_cmd.push_back("compression");
265     make_f2fs_cmd.push_back("-O");
266     make_f2fs_cmd.push_back("extra_attr");
267   }
268   make_f2fs_cmd.push_back(v->blk_device);
269   if (length >= kSectorSize) {
270     make_f2fs_cmd.push_back(std::to_string(length / kSectorSize));
271   }
272 
273   if (exec_cmd(make_f2fs_cmd) != 0) {
274     PLOG(ERROR) << "format_volume: Failed to make_f2fs on " << v->blk_device;
275     return -1;
276   }
277   if (!directory.empty()) {
278     std::vector<std::string> sload_f2fs_cmd = {
279       "/system/bin/sload_f2fs", "-f", directory, "-t", volume, v->blk_device,
280     };
281     if (exec_cmd(sload_f2fs_cmd) != 0) {
282       PLOG(ERROR) << "format_volume: Failed to sload_f2fs on " << v->blk_device;
283       return -1;
284     }
285   }
286   return 0;
287 }
288 
format_volume(const std::string & volume)289 int format_volume(const std::string& volume) {
290   return format_volume(volume, "");
291 }
292 
setup_install_mounts()293 int setup_install_mounts() {
294   if (fstab.empty()) {
295     LOG(ERROR) << "can't set up install mounts: no fstab loaded";
296     return -1;
297   }
298   for (const FstabEntry& entry : fstab) {
299     // We don't want to do anything with "/".
300     if (entry.mount_point == "/") {
301       continue;
302     }
303 
304     if (entry.mount_point == "/tmp" || entry.mount_point == "/cache") {
305       if (ensure_path_mounted(entry.mount_point) != 0) {
306         LOG(ERROR) << "Failed to mount " << entry.mount_point;
307         return -1;
308       }
309     } else {
310       if (ensure_path_unmounted(entry.mount_point) != 0) {
311         LOG(ERROR) << "Failed to unmount " << entry.mount_point;
312         return -1;
313       }
314     }
315   }
316   return 0;
317 }
318 
HasCache()319 bool HasCache() {
320   CHECK(!fstab.empty());
321   static bool has_cache = volume_for_mount_point(CACHE_ROOT) != nullptr;
322   return has_cache;
323 }
324