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 <unistd.h>
23 #include <ctype.h>
24
25 #include "mtdutils/mtdutils.h"
26 #include "mtdutils/mounts.h"
27 #include "roots.h"
28 #include "common.h"
29 #include "make_ext4fs.h"
30
31 static int num_volumes = 0;
32 static Volume* device_volumes = NULL;
33
34 extern struct selabel_handle *sehandle;
35
parse_options(char * options,Volume * volume)36 static int parse_options(char* options, Volume* volume) {
37 char* option;
38 while ((option = strtok(options, ","))) {
39 options = NULL;
40
41 if (strncmp(option, "length=", 7) == 0) {
42 volume->length = strtoll(option+7, NULL, 10);
43 } else {
44 LOGE("bad option \"%s\"\n", option);
45 return -1;
46 }
47 }
48 return 0;
49 }
50
load_volume_table()51 void load_volume_table() {
52 int alloc = 2;
53 device_volumes = (Volume*)malloc(alloc * sizeof(Volume));
54
55 // Insert an entry for /tmp, which is the ramdisk and is always mounted.
56 device_volumes[0].mount_point = "/tmp";
57 device_volumes[0].fs_type = "ramdisk";
58 device_volumes[0].device = NULL;
59 device_volumes[0].device2 = NULL;
60 device_volumes[0].length = 0;
61 num_volumes = 1;
62
63 FILE* fstab = fopen("/etc/recovery.fstab", "r");
64 if (fstab == NULL) {
65 LOGE("failed to open /etc/recovery.fstab (%s)\n", strerror(errno));
66 return;
67 }
68
69 char buffer[1024];
70 int i;
71 while (fgets(buffer, sizeof(buffer)-1, fstab)) {
72 for (i = 0; buffer[i] && isspace(buffer[i]); ++i);
73 if (buffer[i] == '\0' || buffer[i] == '#') continue;
74
75 char* original = strdup(buffer);
76
77 char* mount_point = strtok(buffer+i, " \t\n");
78 char* fs_type = strtok(NULL, " \t\n");
79 char* device = strtok(NULL, " \t\n");
80 // lines may optionally have a second device, to use if
81 // mounting the first one fails.
82 char* options = NULL;
83 char* device2 = strtok(NULL, " \t\n");
84 if (device2) {
85 if (device2[0] == '/') {
86 options = strtok(NULL, " \t\n");
87 } else {
88 options = device2;
89 device2 = NULL;
90 }
91 }
92
93 if (mount_point && fs_type && device) {
94 while (num_volumes >= alloc) {
95 alloc *= 2;
96 device_volumes = (Volume*)realloc(device_volumes, alloc*sizeof(Volume));
97 }
98 device_volumes[num_volumes].mount_point = strdup(mount_point);
99 device_volumes[num_volumes].fs_type = strdup(fs_type);
100 device_volumes[num_volumes].device = strdup(device);
101 device_volumes[num_volumes].device2 =
102 device2 ? strdup(device2) : NULL;
103
104 device_volumes[num_volumes].length = 0;
105 if (parse_options(options, device_volumes + num_volumes) != 0) {
106 LOGE("skipping malformed recovery.fstab line: %s\n", original);
107 } else {
108 ++num_volumes;
109 }
110 } else {
111 LOGE("skipping malformed recovery.fstab line: %s\n", original);
112 }
113 free(original);
114 }
115
116 fclose(fstab);
117
118 printf("recovery filesystem table\n");
119 printf("=========================\n");
120 for (i = 0; i < num_volumes; ++i) {
121 Volume* v = &device_volumes[i];
122 printf(" %d %s %s %s %s %lld\n", i, v->mount_point, v->fs_type,
123 v->device, v->device2, v->length);
124 }
125 printf("\n");
126 }
127
volume_for_path(const char * path)128 Volume* volume_for_path(const char* path) {
129 int i;
130 for (i = 0; i < num_volumes; ++i) {
131 Volume* v = device_volumes+i;
132 int len = strlen(v->mount_point);
133 if (strncmp(path, v->mount_point, len) == 0 &&
134 (path[len] == '\0' || path[len] == '/')) {
135 return v;
136 }
137 }
138 return NULL;
139 }
140
ensure_path_mounted(const char * path)141 int ensure_path_mounted(const char* path) {
142 Volume* v = volume_for_path(path);
143 if (v == NULL) {
144 LOGE("unknown volume for path [%s]\n", path);
145 return -1;
146 }
147 if (strcmp(v->fs_type, "ramdisk") == 0) {
148 // the ramdisk is always mounted.
149 return 0;
150 }
151
152 int result;
153 result = scan_mounted_volumes();
154 if (result < 0) {
155 LOGE("failed to scan mounted volumes\n");
156 return -1;
157 }
158
159 const MountedVolume* mv =
160 find_mounted_volume_by_mount_point(v->mount_point);
161 if (mv) {
162 // volume is already mounted
163 return 0;
164 }
165
166 mkdir(v->mount_point, 0755); // in case it doesn't already exist
167
168 if (strcmp(v->fs_type, "yaffs2") == 0) {
169 // mount an MTD partition as a YAFFS2 filesystem.
170 mtd_scan_partitions();
171 const MtdPartition* partition;
172 partition = mtd_find_partition_by_name(v->device);
173 if (partition == NULL) {
174 LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
175 v->device, v->mount_point);
176 return -1;
177 }
178 return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
179 } else if (strcmp(v->fs_type, "ext4") == 0 ||
180 strcmp(v->fs_type, "vfat") == 0) {
181 result = mount(v->device, v->mount_point, v->fs_type,
182 MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
183 if (result == 0) return 0;
184
185 if (v->device2) {
186 LOGW("failed to mount %s (%s); trying %s\n",
187 v->device, strerror(errno), v->device2);
188 result = mount(v->device2, v->mount_point, v->fs_type,
189 MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
190 if (result == 0) return 0;
191 }
192
193 LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
194 return -1;
195 }
196
197 LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
198 return -1;
199 }
200
ensure_path_unmounted(const char * path)201 int ensure_path_unmounted(const char* path) {
202 Volume* v = volume_for_path(path);
203 if (v == NULL) {
204 LOGE("unknown volume for path [%s]\n", path);
205 return -1;
206 }
207 if (strcmp(v->fs_type, "ramdisk") == 0) {
208 // the ramdisk is always mounted; you can't unmount it.
209 return -1;
210 }
211
212 int result;
213 result = scan_mounted_volumes();
214 if (result < 0) {
215 LOGE("failed to scan mounted volumes\n");
216 return -1;
217 }
218
219 const MountedVolume* mv =
220 find_mounted_volume_by_mount_point(v->mount_point);
221 if (mv == NULL) {
222 // volume is already unmounted
223 return 0;
224 }
225
226 return unmount_mounted_volume(mv);
227 }
228
format_volume(const char * volume)229 int format_volume(const char* volume) {
230 Volume* v = volume_for_path(volume);
231 if (v == NULL) {
232 LOGE("unknown volume \"%s\"\n", volume);
233 return -1;
234 }
235 if (strcmp(v->fs_type, "ramdisk") == 0) {
236 // you can't format the ramdisk.
237 LOGE("can't format_volume \"%s\"", volume);
238 return -1;
239 }
240 if (strcmp(v->mount_point, volume) != 0) {
241 LOGE("can't give path \"%s\" to format_volume\n", volume);
242 return -1;
243 }
244
245 if (ensure_path_unmounted(volume) != 0) {
246 LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
247 return -1;
248 }
249
250 if (strcmp(v->fs_type, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
251 mtd_scan_partitions();
252 const MtdPartition* partition = mtd_find_partition_by_name(v->device);
253 if (partition == NULL) {
254 LOGE("format_volume: no MTD partition \"%s\"\n", v->device);
255 return -1;
256 }
257
258 MtdWriteContext *write = mtd_write_partition(partition);
259 if (write == NULL) {
260 LOGW("format_volume: can't open MTD \"%s\"\n", v->device);
261 return -1;
262 } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
263 LOGW("format_volume: can't erase MTD \"%s\"\n", v->device);
264 mtd_write_close(write);
265 return -1;
266 } else if (mtd_write_close(write)) {
267 LOGW("format_volume: can't close MTD \"%s\"\n", v->device);
268 return -1;
269 }
270 return 0;
271 }
272
273 if (strcmp(v->fs_type, "ext4") == 0) {
274 int result = make_ext4fs(v->device, v->length, volume, sehandle);
275 if (result != 0) {
276 LOGE("format_volume: make_extf4fs failed on %s\n", v->device);
277 return -1;
278 }
279 return 0;
280 }
281
282 LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
283 return -1;
284 }
285