aboutsummaryrefslogtreecommitdiffstats
path: root/roots.cpp
blob: 3c51c35b886425c5659af3348fbcb9409113d45a (plain)
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
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
/*
 * 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 <errno.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>
#include <dirent.h>

#include <fs_mgr.h>
#include "mtdutils/mtdutils.h"
#include "mtdutils/mounts.h"
#include "roots.h"
#include "common.h"
#include "make_ext4fs.h"
extern "C" {
#include "wipe.h"
#include "cryptfs.h"
}

#include "voldclient.h"
#include <blkid/blkid.h>

static struct fstab *fstab = NULL;

extern struct selabel_handle *sehandle;

static int mkdir_p(const char* path, mode_t mode)
{
    char dir[PATH_MAX];
    char* p;
    strcpy(dir, path);
    for (p = strchr(&dir[1], '/'); p != NULL; p = strchr(p+1, '/')) {
        *p = '\0';
        if (mkdir(dir, mode) != 0 && errno != EEXIST) {
            return -1;
        }
        *p = '/';
    }
    if (mkdir(dir, mode) != 0 && errno != EEXIST) {
        return -1;
    }
    return 0;
}

static void write_fstab_entry(Volume *v, FILE *file)
{
    if (NULL != v && strcmp(v->fs_type, "mtd") != 0 && strcmp(v->fs_type, "emmc") != 0
                  && strcmp(v->fs_type, "bml") != 0 && !fs_mgr_is_voldmanaged(v)
                  && strncmp(v->blk_device, "/", 1) == 0
                  && strncmp(v->mount_point, "/", 1) == 0) {

        fprintf(file, "%s ", v->blk_device);
        fprintf(file, "%s ", v->mount_point);
        fprintf(file, "%s ", v->fs_type);
        fprintf(file, "%s 0 0\n", v->fs_options == NULL ? "defaults" : v->fs_options);
    }
}

int get_num_volumes() {
    return fstab->num_entries;
}

Volume* get_device_volumes() {
    return fstab->recs;
}

void load_volume_table()
{
    int i;
    int ret;

    fstab = fs_mgr_read_fstab("/etc/recovery.fstab");
    if (!fstab) {
        LOGE("failed to read /etc/recovery.fstab\n");
        return;
    }

    ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
    if (ret < 0 ) {
        LOGE("failed to add /tmp entry to fstab\n");
        fs_mgr_free_fstab(fstab);
        fstab = NULL;
        return;
    }

    // Create a boring /etc/fstab so tools like Busybox work
    FILE *file = fopen("/etc/fstab", "w");
    if (file == NULL) {
        LOGW("Unable to create /etc/fstab!\n");
        return;
    }

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

        write_fstab_entry(v, file);
    }

    fclose(file);

    printf("\n");
}

bool volume_is_mountable(Volume *v)
{
    return (fs_mgr_is_voldmanaged(v) ||
            !strcmp(v->fs_type, "yaffs2") ||
            !strcmp(v->fs_type, "ext4") ||
            !strcmp(v->fs_type, "f2fs") ||
            !strcmp(v->fs_type, "vfat"));
}

bool volume_is_readonly(Volume *v)
{
    return (v->flags & MS_RDONLY);
}

bool volume_is_verity(Volume *v)
{
    return fs_mgr_is_verified(v);
}

Volume* volume_for_path(const char* path) {
    Volume *rec = fs_mgr_get_entry_for_mount_point(fstab, path);

    if (rec == NULL)
        return rec;

    if (strcmp(rec->fs_type, "ext4") == 0 || strcmp(rec->fs_type, "f2fs") == 0 ||
            strcmp(rec->fs_type, "vfat") == 0) {
        char *detected_fs_type = blkid_get_tag_value(NULL, "TYPE", rec->blk_device);

        if (detected_fs_type == NULL)
            return rec;

        Volume *fetched_rec = rec;
        while (rec != NULL && strcmp(rec->fs_type, detected_fs_type) != 0)
            rec = fs_mgr_get_entry_for_mount_point_after(rec, fstab, path);

        if (rec == NULL)
            return fetched_rec;
    }

    return rec;
}

Volume* volume_for_label(const char* label) {
    int i;
    for (i = 0; i < get_num_volumes(); i++) {
        Volume* v = get_device_volumes() + i;
        if (v->label && !strcmp(v->label, label)) {
            return v;
        }
    }
    return NULL;
}

// Mount the volume specified by path at the given mount_point.
int ensure_path_mounted_at(const char* path, const char* mount_point, bool force_rw) {
    Volume* v = volume_for_path(path);
    if (v == NULL) {
        LOGE("unknown volume for path [%s]\n", path);
        return -1;
    }
    if (strcmp(v->fs_type, "ramdisk") == 0) {
        // the ramdisk is always mounted.
        return 0;
    }

    int result;
    result = scan_mounted_volumes();
    if (result < 0) {
        LOGE("failed to scan mounted volumes\n");
        return -1;
    }

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

    if (!fs_mgr_is_voldmanaged(v)) {
        const MountedVolume* mv =
            find_mounted_volume_by_mount_point(mount_point);
        if (mv) {
            // volume is already mounted
            return 0;
        }
    }

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

    if (strcmp(v->fs_type, "yaffs2") == 0) {
        // mount an MTD partition as a YAFFS2 filesystem.
        mtd_scan_partitions();
        const MtdPartition* partition;
        partition = mtd_find_partition_by_name(v->blk_device);
        if (partition == NULL) {
            LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
                 v->blk_device, mount_point);
            return -1;
        }
        return mtd_mount_partition(partition, mount_point, v->fs_type, 0);
    } else if (strcmp(v->fs_type, "ext4") == 0 ||
               strcmp(v->fs_type, "squashfs") == 0 ||
               strcmp(v->fs_type, "vfat") == 0) {
        unsigned long mntflags = v->flags;
        if (!force_rw) {
            if ((v->flags & MS_RDONLY) || fs_mgr_is_verified(v)) {
                mntflags |= MS_RDONLY;
            }
        }
        result = mount(v->blk_device, mount_point, v->fs_type,
                       mntflags, v->fs_options);
        if (result == 0) return 0;

        LOGE("failed to mount %s (%s)\n", mount_point, strerror(errno));
        return -1;
    }

    LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, mount_point);
    return -1;
}

int ensure_volume_mounted(Volume* v, bool force_rw) {
    if (v == NULL) {
        LOGE("cannot mount unknown volume\n");
        return -1;
    }
    return ensure_path_mounted_at(v->mount_point, nullptr, force_rw);
}

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

int ensure_path_unmounted(const char* path, bool detach /* = false */) {
    Volume* v;
    if (memcmp(path, "/storage/", 9) == 0) {
        char label[PATH_MAX];
        const char* p = path+9;
        const char* q = strchr(p, '/');
        memset(label, 0, sizeof(label));
        if (q) {
            memcpy(label, p, q-p);
        }
        else {
            strcpy(label, p);
        }
        v = volume_for_label(label);
    }
    else {
        v = volume_for_path(path);
    }
    if (v == NULL) {
        LOGE("unknown volume for path [%s]\n", path);
        return -1;
    }
    return ensure_volume_unmounted(v, detach);
}

int ensure_volume_unmounted(Volume* v, bool detach /* = false */) {
    if (v == NULL) {
        LOGE("cannot unmount unknown volume\n");
        return -1;
    }
    if (strcmp(v->fs_type, "ramdisk") == 0) {
        // the ramdisk is always mounted; you can't unmount it.
        return -1;
    }

    int result;
    result = scan_mounted_volumes();
    if (result < 0) {
        LOGE("failed to scan mounted volumes\n");
        return -1;
    }

    const MountedVolume* mv =
        find_mounted_volume_by_mount_point(v->mount_point);
    if (mv == NULL) {
        // volume is already unmounted
        return 0;
    }

    if (detach) {
        result = unmount_mounted_volume_detach(mv);
    }
    else {
        result = unmount_mounted_volume(mv);
    }

    return result;
}

static int exec_cmd(const char* path, char* const argv[]) {
    int status;
    pid_t child;
    if ((child = vfork()) == 0) {
        execv(path, argv);
        _exit(-1);
    }
    waitpid(child, &status, 0);
    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
        LOGE("%s failed with status %d\n", path, WEXITSTATUS(status));
    }
    return WEXITSTATUS(status);
}

static int rmtree_except(const char* path, const char* except)
{
    char pathbuf[PATH_MAX];
    int rc = 0;
    DIR* dp = opendir(path);
    if (dp == NULL) {
        return -1;
    }
    struct dirent* de;
    while ((de = readdir(dp)) != NULL) {
        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
            continue;
        if (except && !strcmp(de->d_name, except))
            continue;
        struct stat st;
        snprintf(pathbuf, sizeof(pathbuf), "%s/%s", path, de->d_name);
        rc = lstat(pathbuf, &st);
        if (rc != 0) {
            LOGE("Failed to stat %s\n", pathbuf);
            break;
        }
        if (S_ISDIR(st.st_mode)) {
            rc = rmtree_except(pathbuf, NULL);
            if (rc != 0)
                break;
            rc = rmdir(pathbuf);
        }
        else {
            rc = unlink(pathbuf);
        }
        if (rc != 0) {
            LOGI("Failed to remove %s: %s\n", pathbuf, strerror(errno));
            break;
        }
    }
    closedir(dp);
    return rc;
}

int format_volume(const char* volume, bool force) {
    if (strcmp(volume, "media") == 0) {
        if (!vdc->isEmulatedStorage()) {
            return 0;
        }
        if (ensure_path_mounted("/data") != 0) {
            LOGE("format_volume failed to mount /data\n");
            return -1;
        }
        int rc = 0;
        rc = rmtree_except("/data/media", NULL);
        ensure_path_unmounted("/data");
        return rc;
    }

    Volume* v = volume_for_path(volume);
    if (v == NULL) {
        LOGE("unknown volume \"%s\"\n", volume);
        return -1;
    }
    if (strcmp(v->fs_type, "ramdisk") == 0) {
        // you can't format the ramdisk.
        LOGE("can't format_volume \"%s\"", volume);
        return -1;
    }
    if (strcmp(v->mount_point, volume) != 0) {
        LOGE("can't give path \"%s\" to format_volume\n", volume);
        return -1;
    }

    if (!force && strcmp(volume, "/data") == 0 && vdc->isEmulatedStorage()) {
        if (ensure_path_mounted("/data") == 0) {
            // Preserve .layout_version to avoid "nesting bug"
            LOGI("Preserving layout version\n");
            unsigned char layout_buf[256];
            ssize_t layout_buflen = -1;
            int fd;
            fd = open("/data/.layout_version", O_RDONLY);
            if (fd != -1) {
                layout_buflen = read(fd, layout_buf, sizeof(layout_buf));
                close(fd);
            }

            int rc = rmtree_except("/data", "media");

            // Restore .layout_version
            if (layout_buflen > 0) {
                LOGI("Restoring layout version\n");
                fd = open("/data/.layout_version", O_WRONLY | O_CREAT | O_EXCL, 0600);
                if (fd != -1) {
                    write(fd, layout_buf, layout_buflen);
                    close(fd);
                }
            }

            ensure_path_unmounted(volume);

            return rc;
        }
        LOGE("format_volume failed to mount /data, formatting instead\n");
    }

    if (ensure_path_unmounted(volume) != 0) {
        LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
        return -1;
    }

    if (fs_mgr_is_voldmanaged(v)) {
        LOGE("can't format vold volume \"%s\"", volume);
        return -1;
    }

    if (strcmp(v->fs_type, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
        mtd_scan_partitions();
        const MtdPartition* partition = mtd_find_partition_by_name(v->blk_device);
        if (partition == NULL) {
            LOGE("format_volume: no MTD partition \"%s\"\n", v->blk_device);
            return -1;
        }

        MtdWriteContext *write = mtd_write_partition(partition);
        if (write == NULL) {
            LOGW("format_volume: can't open MTD \"%s\"\n", v->blk_device);
            return -1;
        } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
            LOGW("format_volume: can't erase MTD \"%s\"\n", v->blk_device);
            mtd_write_close(write);
            return -1;
        } else if (mtd_write_close(write)) {
            LOGW("format_volume: can't close MTD \"%s\"\n", v->blk_device);
            return -1;
        }
        return 0;
    }

    if (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "f2fs") == 0) {
        // 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 != NULL && v->key_loc[0] == '/') {
            LOGI("wiping %s\n", v->key_loc);
            int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
            if (fd < 0) {
                LOGE("format_volume: failed to open %s\n", v->key_loc);
                return -1;
            }
            wipe_block_device(fd, get_file_size(fd));
            close(fd);
        }

        ssize_t length = 0;
        if (v->length != 0) {
            length = v->length;
        } else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
            length = -CRYPT_FOOTER_OFFSET;
        }
        int result;
        if (strcmp(v->fs_type, "ext4") == 0) {
            result = make_ext4fs(v->blk_device, length, volume, sehandle);
        } else {   /* Has to be f2fs because we checked earlier. */
            char bytes_reserved[20], num_sectors[20];
            const char* f2fs_argv[6] = {"mkfs.f2fs", "-t1"};
            if (length < 0) {
                snprintf(bytes_reserved, sizeof(bytes_reserved), "%zd", -length);
                f2fs_argv[2] = "-r";
                f2fs_argv[3] = bytes_reserved;
                f2fs_argv[4] = v->blk_device;
                f2fs_argv[5] = NULL;
            } else {
                /* num_sectors can be zero which mean whole device space */
                snprintf(num_sectors, sizeof(num_sectors), "%zd", length / 512);
                f2fs_argv[2] = v->blk_device;
                f2fs_argv[3] = num_sectors;
                f2fs_argv[4] = NULL;
            }
            const char *f2fs_path = "/sbin/mkfs.f2fs";

            result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
        }
        if (result != 0) {
            LOGE("format_volume: make %s failed on %s with %d(%s)\n", v->fs_type, v->blk_device, result, strerror(errno));
            return -1;
        }
        return 0;
    }

    LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
    return -1;
}

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

        if (strcmp(v->mount_point, "/tmp") == 0 ||
            strcmp(v->mount_point, "/cache") == 0) {
            if (ensure_path_mounted(v->mount_point) != 0) {
                LOGE("failed to mount %s\n", v->mount_point);
                return -1;
            }

        } else {
            // datamedia and anything managed by vold must be unmounted
            // with the detach flag to ensure that FUSE works.
            bool detach = false;
            if (vdc->isEmulatedStorage() && strcmp(v->mount_point, "/data") == 0) {
                detach = true;
            }
            if (ensure_volume_unmounted(v, detach) != 0) {
                LOGE("failed to unmount %s\n", v->mount_point);
                return -1;
            }
        }
    }
    return 0;
}