aboutsummaryrefslogtreecommitdiffstats
blob: eb299ad6b8d33fc52af0702c74920d1952ecd3a3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "roots.h"

#include <ctype.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include <algorithm>
#include <string>
#include <vector>

#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <cryptfs.h>
#include <ext4_utils/wipe.h>
#include <fs_mgr.h>

#include "mounts.h"

static struct fstab* fstab = nullptr;

extern struct selabel_handle* sehandle;

void load_volume_table() {
  fstab = fs_mgr_read_fstab_default();
  if (!fstab) {
    LOG(ERROR) << "Failed to read default fstab";
    return;
  }

  int ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
  if (ret == -1) {
    LOG(ERROR) << "Failed to add /tmp entry to fstab";
    fs_mgr_free_fstab(fstab);
    fstab = nullptr;
    return;
  }

  printf("recovery filesystem table\n");
  printf("=========================\n");
  for (int i = 0; i < fstab->num_entries; ++i) {
    const Volume* v = &fstab->recs[i];
    printf("  %d %s %s %s %lld\n", i, v->mount_point, v->fs_type, v->blk_device, v->length);
  }
  printf("\n");
}

Volume* volume_for_mount_point(const std::string& mount_point) {
  return fs_mgr_get_entry_for_mount_point(fstab, mount_point);
}

// Finds the volume specified by the given path. fs_mgr_get_entry_for_mount_point() does exact match
// only, so it attempts the prefixes recursively (e.g. "/cache/recovery/last_log",
// "/cache/recovery", "/cache", "/" for a given path of "/cache/recovery/last_log") and returns the
// first match or nullptr.
static Volume* volume_for_path(const char* path) {
  if (path == nullptr || path[0] == '\0') return nullptr;
  std::string str(path);
  while (true) {
    Volume* result = fs_mgr_get_entry_for_mount_point(fstab, str);
    if (result != nullptr || str == "/") {
      return result;
    }
    size_t slash = str.find_last_of('/');
    if (slash == std::string::npos) return nullptr;
    if (slash == 0) {
      str = "/";
    } else {
      str = str.substr(0, slash);
    }
  }
  return nullptr;
}

// Mount the volume specified by path at the given mount_point.
int ensure_path_mounted_at(const char* path, const char* mount_point) {
  Volume* v = volume_for_path(path);
  if (v == nullptr) {
    LOG(ERROR) << "unknown volume for path [" << path << "]";
    return -1;
  }
  if (strcmp(v->fs_type, "ramdisk") == 0) {
    // The ramdisk is always mounted.
    return 0;
  }

  if (!scan_mounted_volumes()) {
    LOG(ERROR) << "Failed to scan mounted volumes";
    return -1;
  }

  if (!mount_point) {
    mount_point = v->mount_point;
  }

  const MountedVolume* mv = find_mounted_volume_by_mount_point(mount_point);
  if (mv != nullptr) {
    // Volume is already mounted.
    return 0;
  }

  mkdir(mount_point, 0755);  // in case it doesn't already exist

  if (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "squashfs") == 0 ||
      strcmp(v->fs_type, "vfat") == 0) {
    int result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
    if (result == -1 && fs_mgr_is_formattable(v)) {
      PLOG(ERROR) << "Failed to mount " << mount_point << "; formatting";
      bool crypt_footer = fs_mgr_is_encryptable(v) && !strcmp(v->key_loc, "footer");
      if (fs_mgr_do_format(v, crypt_footer) == 0) {
        result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
      } else {
        PLOG(ERROR) << "Failed to format " << mount_point;
        return -1;
      }
    }

    if (result == -1) {
      PLOG(ERROR) << "Failed to mount " << mount_point;
      return -1;
    }
    return 0;
  }

  LOG(ERROR) << "unknown fs_type \"" << v->fs_type << "\" for " << mount_point;
  return -1;
}

int ensure_path_mounted(const char* path) {
  // Mount at the default mount point.
  return ensure_path_mounted_at(path, nullptr);
}

int ensure_path_unmounted(const char* path) {
  const Volume* v = volume_for_path(path);
  if (v == nullptr) {
    LOG(ERROR) << "unknown volume for path [" << path << "]";
    return -1;
  }
  if (strcmp(v->fs_type, "ramdisk") == 0) {
    // The ramdisk is always mounted; you can't unmount it.
    return -1;
  }

  if (!scan_mounted_volumes()) {
    LOG(ERROR) << "Failed to scan mounted volumes";
    return -1;
  }

  MountedVolume* mv = find_mounted_volume_by_mount_point(v->mount_point);
  if (mv == nullptr) {
    // Volume is already unmounted.
    return 0;
  }

  return unmount_mounted_volume(mv);
}

static int exec_cmd(const std::vector<std::string>& args) {
  CHECK_NE(static_cast<size_t>(0), args.size());

  std::vector<char*> argv(args.size());
  std::transform(args.cbegin(), args.cend(), argv.begin(),
                 [](const std::string& arg) { return const_cast<char*>(arg.c_str()); });
  argv.push_back(nullptr);

  pid_t child;
  if ((child = vfork()) == 0) {
    execv(argv[0], argv.data());
    _exit(EXIT_FAILURE);
  }

  int status;
  waitpid(child, &status, 0);
  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
    LOG(ERROR) << args[0] << " failed with status " << WEXITSTATUS(status);
  }
  return WEXITSTATUS(status);
}

static int64_t get_file_size(int fd, uint64_t reserve_len) {
  struct stat buf;
  int ret = fstat(fd, &buf);
  if (ret) return 0;

  int64_t computed_size;
  if (S_ISREG(buf.st_mode)) {
    computed_size = buf.st_size - reserve_len;
  } else if (S_ISBLK(buf.st_mode)) {
    uint64_t block_device_size = get_block_device_size(fd);
    if (block_device_size < reserve_len ||
        block_device_size > std::numeric_limits<int64_t>::max()) {
      computed_size = 0;
    } else {
      computed_size = block_device_size - reserve_len;
    }
  } else {
    computed_size = 0;
  }

  return computed_size;
}

int format_volume(const char* volume, const char* directory) {
  const Volume* v = volume_for_path(volume);
  if (v == nullptr) {
    LOG(ERROR) << "unknown volume \"" << volume << "\"";
    return -1;
  }
  if (strcmp(v->fs_type, "ramdisk") == 0) {
    LOG(ERROR) << "can't format_volume \"" << volume << "\"";
    return -1;
  }
  if (strcmp(v->mount_point, volume) != 0) {
    LOG(ERROR) << "can't give path \"" << volume << "\" to format_volume";
    return -1;
  }
  if (ensure_path_unmounted(volume) != 0) {
    LOG(ERROR) << "format_volume: Failed to unmount \"" << v->mount_point << "\"";
    return -1;
  }
  if (strcmp(v->fs_type, "ext4") != 0 && strcmp(v->fs_type, "f2fs") != 0) {
    LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
    return -1;
  }

  // If there's a key_loc that looks like a path, it should be a block device for storing encryption
  // metadata. Wipe it too.
  if (v->key_loc != nullptr && v->key_loc[0] == '/') {
    LOG(INFO) << "Wiping " << v->key_loc;
    int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
    if (fd == -1) {
      PLOG(ERROR) << "format_volume: Failed to open " << v->key_loc;
      return -1;
    }
    wipe_block_device(fd, get_file_size(fd));
    close(fd);
  }

  int64_t length = 0;
  if (v->length > 0) {
    length = v->length;
  } else if (v->length < 0 ||
             (v->key_loc != nullptr && strcmp(v->key_loc, "footer") == 0)) {
    android::base::unique_fd fd(open(v->blk_device, O_RDONLY));
    if (fd == -1) {
      PLOG(ERROR) << "format_volume: failed to open " << v->blk_device;
      return -1;
    }
    length =
        get_file_size(fd.get(), v->length ? -v->length : CRYPT_FOOTER_OFFSET);
    if (length <= 0) {
      LOG(ERROR) << "get_file_size: invalid size " << length << " for "
                 << v->blk_device;
      return -1;
    }
  }

  if (strcmp(v->fs_type, "ext4") == 0) {
    static constexpr int kBlockSize = 4096;
    std::vector<std::string> mke2fs_args = {
      "/sbin/mke2fs_static", "-F", "-t", "ext4", "-b", std::to_string(kBlockSize),
    };

    int raid_stride = v->logical_blk_size / kBlockSize;
    int raid_stripe_width = v->erase_blk_size / kBlockSize;
    // stride should be the max of 8KB and logical block size
    if (v->logical_blk_size != 0 && v->logical_blk_size < 8192) {
      raid_stride = 8192 / kBlockSize;
    }
    if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
      mke2fs_args.push_back("-E");
      mke2fs_args.push_back(
          android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride, raid_stripe_width));
    }
    mke2fs_args.push_back(v->blk_device);
    if (length != 0) {
      mke2fs_args.push_back(std::to_string(length / kBlockSize));
    }

    int result = exec_cmd(mke2fs_args);
    if (result == 0 && directory != nullptr) {
      std::vector<std::string> e2fsdroid_args = {
        "/sbin/e2fsdroid_static",
        "-e",
        "-f",
        directory,
        "-a",
        volume,
        v->blk_device,
      };
      result = exec_cmd(e2fsdroid_args);
    }

    if (result != 0) {
      PLOG(ERROR) << "format_volume: Failed to make ext4 on " << v->blk_device;
      return -1;
    }
    return 0;
  }

  // Has to be f2fs because we checked earlier.
  std::vector<std::string> f2fs_args = { "/sbin/mkfs.f2fs", "-d1", "-f",
                                         "-O", "encrypt", "-O", "quota",
                                         v->blk_device };
  if (length >= 512) {
    f2fs_args.push_back(std::to_string(length / 512));
  }

  int result = exec_cmd(f2fs_args);
  if (result != 0) {
    PLOG(ERROR) << "format_volume: Failed to make f2fs on " << v->blk_device;
    return -1;
  }
  return 0;
}

int format_volume(const char* volume) {
  return format_volume(volume, nullptr);
}

int setup_install_mounts() {
  if (fstab == nullptr) {
    LOG(ERROR) << "can't set up install mounts: no fstab loaded";
    return -1;
  }
  for (int i = 0; i < fstab->num_entries; ++i) {
    const Volume* v = fstab->recs + i;

    // We don't want to do anything with "/".
    if (strcmp(v->mount_point, "/") == 0) {
      continue;
    }

    if (strcmp(v->mount_point, "/tmp") == 0 || strcmp(v->mount_point, "/cache") == 0) {
      if (ensure_path_mounted(v->mount_point) != 0) {
        LOG(ERROR) << "Failed to mount " << v->mount_point;
        return -1;
      }
    } else {
      if (ensure_path_unmounted(v->mount_point) != 0) {
        LOG(ERROR) << "Failed to unmount " << v->mount_point;
        return -1;
      }
    }
  }
  return 0;
}