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 <errno.h>
18#include <stdlib.h>
19#include <sys/mount.h>
20#include <sys/stat.h>
21#include <sys/types.h>
22#include <sys/wait.h>
23#include <unistd.h>
24#include <ctype.h>
25#include <fcntl.h>
26
27#include <fs_mgr.h>
28#include "mtdutils/mtdutils.h"
29#include "mtdutils/mounts.h"
30#include "roots.h"
31#include "common.h"
32#include "make_ext4fs.h"
33extern "C" {
34#include "wipe.h"
35#include "cryptfs.h"
36}
37
38static struct fstab *fstab = NULL;
39
40extern struct selabel_handle *sehandle;
41
42void load_volume_table()
43{
44    int i;
45    int ret;
46
47    fstab = fs_mgr_read_fstab("/etc/recovery.fstab");
48    if (!fstab) {
49        LOGE("failed to read /etc/recovery.fstab\n");
50        return;
51    }
52
53    ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
54    if (ret < 0 ) {
55        LOGE("failed to add /tmp entry to fstab\n");
56        fs_mgr_free_fstab(fstab);
57        fstab = NULL;
58        return;
59    }
60
61    printf("recovery filesystem table\n");
62    printf("=========================\n");
63    for (i = 0; i < fstab->num_entries; ++i) {
64        Volume* v = &fstab->recs[i];
65        printf("  %d %s %s %s %lld\n", i, v->mount_point, v->fs_type,
66               v->blk_device, v->length);
67    }
68    printf("\n");
69}
70
71Volume* volume_for_path(const char* path) {
72    return fs_mgr_get_entry_for_mount_point(fstab, path);
73}
74
75int ensure_path_mounted(const char* path) {
76    Volume* v = volume_for_path(path);
77    if (v == NULL) {
78        LOGE("unknown volume for path [%s]\n", path);
79        return -1;
80    }
81    if (strcmp(v->fs_type, "ramdisk") == 0) {
82        // the ramdisk is always mounted.
83        return 0;
84    }
85
86    int result;
87    result = scan_mounted_volumes();
88    if (result < 0) {
89        LOGE("failed to scan mounted volumes\n");
90        return -1;
91    }
92
93    const MountedVolume* mv =
94        find_mounted_volume_by_mount_point(v->mount_point);
95    if (mv) {
96        // volume is already mounted
97        return 0;
98    }
99
100    mkdir(v->mount_point, 0755);  // in case it doesn't already exist
101
102    if (strcmp(v->fs_type, "yaffs2") == 0) {
103        // mount an MTD partition as a YAFFS2 filesystem.
104        mtd_scan_partitions();
105        const MtdPartition* partition;
106        partition = mtd_find_partition_by_name(v->blk_device);
107        if (partition == NULL) {
108            LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
109                 v->blk_device, v->mount_point);
110            return -1;
111        }
112        return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
113    } else if (strcmp(v->fs_type, "ext4") == 0 ||
114               strcmp(v->fs_type, "vfat") == 0) {
115        result = mount(v->blk_device, v->mount_point, v->fs_type,
116                       MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
117        if (result == 0) return 0;
118
119        LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
120        return -1;
121    }
122
123    LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
124    return -1;
125}
126
127int ensure_path_unmounted(const char* path) {
128    Volume* v = volume_for_path(path);
129    if (v == NULL) {
130        LOGE("unknown volume for path [%s]\n", path);
131        return -1;
132    }
133    if (strcmp(v->fs_type, "ramdisk") == 0) {
134        // the ramdisk is always mounted; you can't unmount it.
135        return -1;
136    }
137
138    int result;
139    result = scan_mounted_volumes();
140    if (result < 0) {
141        LOGE("failed to scan mounted volumes\n");
142        return -1;
143    }
144
145    const MountedVolume* mv =
146        find_mounted_volume_by_mount_point(v->mount_point);
147    if (mv == NULL) {
148        // volume is already unmounted
149        return 0;
150    }
151
152    return unmount_mounted_volume(mv);
153}
154
155static int exec_cmd(const char* path, char* const argv[]) {
156    int status;
157    pid_t child;
158    if ((child = vfork()) == 0) {
159        execv(path, argv);
160        _exit(-1);
161    }
162    waitpid(child, &status, 0);
163    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
164        LOGE("%s failed with status %d\n", path, WEXITSTATUS(status));
165    }
166    return WEXITSTATUS(status);
167}
168
169int format_volume(const char* volume) {
170    Volume* v = volume_for_path(volume);
171    if (v == NULL) {
172        LOGE("unknown volume \"%s\"\n", volume);
173        return -1;
174    }
175    if (strcmp(v->fs_type, "ramdisk") == 0) {
176        // you can't format the ramdisk.
177        LOGE("can't format_volume \"%s\"", volume);
178        return -1;
179    }
180    if (strcmp(v->mount_point, volume) != 0) {
181        LOGE("can't give path \"%s\" to format_volume\n", volume);
182        return -1;
183    }
184
185    if (ensure_path_unmounted(volume) != 0) {
186        LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
187        return -1;
188    }
189
190    if (strcmp(v->fs_type, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
191        mtd_scan_partitions();
192        const MtdPartition* partition = mtd_find_partition_by_name(v->blk_device);
193        if (partition == NULL) {
194            LOGE("format_volume: no MTD partition \"%s\"\n", v->blk_device);
195            return -1;
196        }
197
198        MtdWriteContext *write = mtd_write_partition(partition);
199        if (write == NULL) {
200            LOGW("format_volume: can't open MTD \"%s\"\n", v->blk_device);
201            return -1;
202        } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
203            LOGW("format_volume: can't erase MTD \"%s\"\n", v->blk_device);
204            mtd_write_close(write);
205            return -1;
206        } else if (mtd_write_close(write)) {
207            LOGW("format_volume: can't close MTD \"%s\"\n", v->blk_device);
208            return -1;
209        }
210        return 0;
211    }
212
213    if (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "f2fs") == 0) {
214        // if there's a key_loc that looks like a path, it should be a
215        // block device for storing encryption metadata.  wipe it too.
216        if (v->key_loc != NULL && v->key_loc[0] == '/') {
217            LOGI("wiping %s\n", v->key_loc);
218            int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
219            if (fd < 0) {
220                LOGE("format_volume: failed to open %s\n", v->key_loc);
221                return -1;
222            }
223            wipe_block_device(fd, get_file_size(fd));
224            close(fd);
225        }
226
227        ssize_t length = 0;
228        if (v->length != 0) {
229            length = v->length;
230        } else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
231            length = -CRYPT_FOOTER_OFFSET;
232        }
233        int result;
234        if (strcmp(v->fs_type, "ext4") == 0) {
235            result = make_ext4fs(v->blk_device, length, volume, sehandle);
236        } else {   /* Has to be f2fs because we checked earlier. */
237            if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0 && length < 0) {
238                LOGE("format_volume: crypt footer + negative length (%zd) not supported on %s\n", length, v->fs_type);
239                return -1;
240            }
241            if (length < 0) {
242                LOGE("format_volume: negative length (%zd) not supported on %s\n", length, v->fs_type);
243                return -1;
244            }
245            char *num_sectors;
246            if (asprintf(&num_sectors, "%zd", length / 512) <= 0) {
247                LOGE("format_volume: failed to create %s command for %s\n", v->fs_type, v->blk_device);
248                return -1;
249            }
250            const char *f2fs_path = "/sbin/mkfs.f2fs";
251            const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, NULL};
252
253            result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
254            free(num_sectors);
255        }
256        if (result != 0) {
257            LOGE("format_volume: make %s failed on %s with %d(%s)\n", v->fs_type, v->blk_device, result, strerror(errno));
258            return -1;
259        }
260        return 0;
261    }
262
263    LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
264    return -1;
265}
266
267int setup_install_mounts() {
268    if (fstab == NULL) {
269        LOGE("can't set up install mounts: no fstab loaded\n");
270        return -1;
271    }
272    for (int i = 0; i < fstab->num_entries; ++i) {
273        Volume* v = fstab->recs + i;
274
275        if (strcmp(v->mount_point, "/tmp") == 0 ||
276            strcmp(v->mount_point, "/cache") == 0) {
277            if (ensure_path_mounted(v->mount_point) != 0) {
278                LOGE("failed to mount %s\n", v->mount_point);
279                return -1;
280            }
281
282        } else {
283            if (ensure_path_unmounted(v->mount_point) != 0) {
284                LOGE("failed to unmount %s\n", v->mount_point);
285                return -1;
286            }
287        }
288    }
289    return 0;
290}
291