1 /*
2 * Copyright (C) 2008 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 <stdio.h>
18 #include <stdlib.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21 #include <errno.h>
22 #include <string.h>
23
24 #include <sys/mount.h>
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <sys/ioctl.h>
28
29 #include <linux/kdev_t.h>
30
31 #define LOG_TAG "Vold"
32
33 #include <cutils/log.h>
34
35 #include <sysutils/SocketClient.h>
36 #include "Loop.h"
37 #include "Asec.h"
38 #include "VoldUtil.h"
39 #include "sehandle.h"
40
dumpState(SocketClient * c)41 int Loop::dumpState(SocketClient *c) {
42 int i;
43 int fd;
44 char filename[256];
45
46 for (i = 0; i < LOOP_MAX; i++) {
47 struct loop_info64 li;
48 int rc;
49
50 sprintf(filename, "/dev/block/loop%d", i);
51
52 if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
53 if (errno != ENOENT) {
54 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
55 } else {
56 continue;
57 }
58 return -1;
59 }
60
61 rc = ioctl(fd, LOOP_GET_STATUS64, &li);
62 close(fd);
63 if (rc < 0 && errno == ENXIO) {
64 continue;
65 }
66
67 if (rc < 0) {
68 SLOGE("Unable to get loop status for %s (%s)", filename,
69 strerror(errno));
70 return -1;
71 }
72 char *tmp = NULL;
73 asprintf(&tmp, "%s %d %lld:%lld %llu %lld:%lld %lld 0x%x {%s} {%s}", filename, li.lo_number,
74 MAJOR(li.lo_device), MINOR(li.lo_device), li.lo_inode, MAJOR(li.lo_rdevice),
75 MINOR(li.lo_rdevice), li.lo_offset, li.lo_flags, li.lo_crypt_name,
76 li.lo_file_name);
77 c->sendMsg(0, tmp, false);
78 free(tmp);
79 }
80 return 0;
81 }
82
lookupActive(const char * id,char * buffer,size_t len)83 int Loop::lookupActive(const char *id, char *buffer, size_t len) {
84 int i;
85 int fd;
86 char filename[256];
87
88 memset(buffer, 0, len);
89
90 for (i = 0; i < LOOP_MAX; i++) {
91 struct loop_info64 li;
92 int rc;
93
94 sprintf(filename, "/dev/block/loop%d", i);
95
96 if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
97 if (errno != ENOENT) {
98 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
99 } else {
100 continue;
101 }
102 return -1;
103 }
104
105 rc = ioctl(fd, LOOP_GET_STATUS64, &li);
106 close(fd);
107 if (rc < 0 && errno == ENXIO) {
108 continue;
109 }
110
111 if (rc < 0) {
112 SLOGE("Unable to get loop status for %s (%s)", filename,
113 strerror(errno));
114 return -1;
115 }
116 if (!strncmp((const char*) li.lo_crypt_name, id, LO_NAME_SIZE)) {
117 break;
118 }
119 }
120
121 if (i == LOOP_MAX) {
122 errno = ENOENT;
123 return -1;
124 }
125 strlcpy(buffer, filename, len);
126 return 0;
127 }
128
create(const char * id,const char * loopFile,char * loopDeviceBuffer,size_t len)129 int Loop::create(const char *id, const char *loopFile, char *loopDeviceBuffer, size_t len) {
130 int i;
131 int fd;
132 char filename[256];
133
134 for (i = 0; i < LOOP_MAX; i++) {
135 struct loop_info64 li;
136 int rc;
137 char *secontext = NULL;
138
139 sprintf(filename, "/dev/block/loop%d", i);
140
141 /*
142 * The kernel starts us off with 8 loop nodes, but more
143 * are created on-demand if needed.
144 */
145 mode_t mode = 0660 | S_IFBLK;
146 unsigned int dev = (0xff & i) | ((i << 12) & 0xfff00000) | (7 << 8);
147
148 if (sehandle) {
149 rc = selabel_lookup(sehandle, &secontext, filename, S_IFBLK);
150 if (rc == 0)
151 setfscreatecon(secontext);
152 }
153
154 if (mknod(filename, mode, dev) < 0) {
155 if (errno != EEXIST) {
156 int sverrno = errno;
157 SLOGE("Error creating loop device node (%s)", strerror(errno));
158 if (secontext) {
159 freecon(secontext);
160 setfscreatecon(NULL);
161 }
162 errno = sverrno;
163 return -1;
164 }
165 }
166 if (secontext) {
167 freecon(secontext);
168 setfscreatecon(NULL);
169 }
170
171 if ((fd = open(filename, O_RDWR | O_CLOEXEC)) < 0) {
172 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
173 return -1;
174 }
175
176 rc = ioctl(fd, LOOP_GET_STATUS64, &li);
177 if (rc < 0 && errno == ENXIO)
178 break;
179
180 close(fd);
181
182 if (rc < 0) {
183 SLOGE("Unable to get loop status for %s (%s)", filename,
184 strerror(errno));
185 return -1;
186 }
187 }
188
189 if (i == LOOP_MAX) {
190 SLOGE("Exhausted all loop devices");
191 errno = ENOSPC;
192 return -1;
193 }
194
195 strlcpy(loopDeviceBuffer, filename, len);
196
197 int file_fd;
198
199 if ((file_fd = open(loopFile, O_RDWR | O_CLOEXEC)) < 0) {
200 SLOGE("Unable to open %s (%s)", loopFile, strerror(errno));
201 close(fd);
202 return -1;
203 }
204
205 if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) {
206 SLOGE("Error setting up loopback interface (%s)", strerror(errno));
207 close(file_fd);
208 close(fd);
209 return -1;
210 }
211
212 struct loop_info64 li;
213
214 memset(&li, 0, sizeof(li));
215 strlcpy((char*) li.lo_crypt_name, id, LO_NAME_SIZE);
216 strlcpy((char*) li.lo_file_name, loopFile, LO_NAME_SIZE);
217
218 if (ioctl(fd, LOOP_SET_STATUS64, &li) < 0) {
219 SLOGE("Error setting loopback status (%s)", strerror(errno));
220 close(file_fd);
221 close(fd);
222 return -1;
223 }
224
225 close(fd);
226 close(file_fd);
227
228 return 0;
229 }
230
destroyByDevice(const char * loopDevice)231 int Loop::destroyByDevice(const char *loopDevice) {
232 int device_fd;
233
234 device_fd = open(loopDevice, O_RDONLY | O_CLOEXEC);
235 if (device_fd < 0) {
236 SLOGE("Failed to open loop (%d)", errno);
237 return -1;
238 }
239
240 if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
241 SLOGE("Failed to destroy loop (%d)", errno);
242 close(device_fd);
243 return -1;
244 }
245
246 close(device_fd);
247 return 0;
248 }
249
destroyByFile(const char *)250 int Loop::destroyByFile(const char * /*loopFile*/) {
251 errno = ENOSYS;
252 return -1;
253 }
254
createImageFile(const char * file,unsigned int numSectors)255 int Loop::createImageFile(const char *file, unsigned int numSectors) {
256 int fd;
257
258 if ((fd = creat(file, 0600)) < 0) {
259 SLOGE("Error creating imagefile (%s)", strerror(errno));
260 return -1;
261 }
262
263 if (ftruncate(fd, numSectors * 512) < 0) {
264 SLOGE("Error truncating imagefile (%s)", strerror(errno));
265 close(fd);
266 return -1;
267 }
268 close(fd);
269 return 0;
270 }
271
resizeImageFile(const char * file,unsigned int numSectors)272 int Loop::resizeImageFile(const char *file, unsigned int numSectors) {
273 int fd;
274
275 if ((fd = open(file, O_RDWR | O_CLOEXEC)) < 0) {
276 SLOGE("Error opening imagefile (%s)", strerror(errno));
277 return -1;
278 }
279
280 SLOGD("Attempting to increase size of %s to %d sectors.", file, numSectors);
281
282 if (fallocate(fd, 0, 0, numSectors * 512)) {
283 if (errno == ENOSYS || errno == ENOTSUP) {
284 SLOGW("fallocate not found. Falling back to ftruncate.");
285 if (ftruncate(fd, numSectors * 512) < 0) {
286 SLOGE("Error truncating imagefile (%s)", strerror(errno));
287 close(fd);
288 return -1;
289 }
290 } else {
291 SLOGE("Error allocating space (%s)", strerror(errno));
292 close(fd);
293 return -1;
294 }
295 }
296 close(fd);
297 return 0;
298 }
299
lookupInfo(const char * loopDevice,struct asec_superblock * sb,unsigned long * nr_sec)300 int Loop::lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned long *nr_sec) {
301 int fd;
302 struct asec_superblock buffer;
303
304 if ((fd = open(loopDevice, O_RDONLY | O_CLOEXEC)) < 0) {
305 SLOGE("Failed to open loopdevice (%s)", strerror(errno));
306 destroyByDevice(loopDevice);
307 return -1;
308 }
309
310 get_blkdev_size(fd, nr_sec);
311 if (*nr_sec == 0) {
312 SLOGE("Failed to get loop size (%s)", strerror(errno));
313 destroyByDevice(loopDevice);
314 close(fd);
315 return -1;
316 }
317
318 /*
319 * Try to read superblock.
320 */
321 memset(&buffer, 0, sizeof(struct asec_superblock));
322 if (lseek(fd, ((*nr_sec - 1) * 512), SEEK_SET) < 0) {
323 SLOGE("lseek failed (%s)", strerror(errno));
324 close(fd);
325 destroyByDevice(loopDevice);
326 return -1;
327 }
328 if (read(fd, &buffer, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
329 SLOGE("superblock read failed (%s)", strerror(errno));
330 close(fd);
331 destroyByDevice(loopDevice);
332 return -1;
333 }
334 close(fd);
335
336 /*
337 * Superblock successfully read. Copy to caller's struct.
338 */
339 memcpy(sb, &buffer, sizeof(struct asec_superblock));
340 return 0;
341 }
342