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 <stdlib.h>
18#include <string.h>
19#include <dirent.h>
20#include <errno.h>
21#include <fcntl.h>
22
23#include <sys/types.h>
24#include <sys/stat.h>
25#include <sys/types.h>
26#include <sys/mman.h>
27#include <sys/mount.h>
28
29#include <linux/kdev_t.h>
30
31#include <cutils/properties.h>
32
33#include <diskconfig/diskconfig.h>
34
35#define LOG_TAG "Vold"
36
37#include <cutils/log.h>
38
39#include "Volume.h"
40#include "VolumeManager.h"
41#include "ResponseCode.h"
42#include "Fat.h"
43#include "Process.h"
44
45extern "C" void dos_partition_dec(void const *pp, struct dos_partition *d);
46extern "C" void dos_partition_enc(void *pp, struct dos_partition *d);
47
48
49/*
50 * Secure directory - stuff that only root can see
51 */
52const char *Volume::SECDIR            = "/mnt/secure";
53
54/*
55 * Secure staging directory - where media is mounted for preparation
56 */
57const char *Volume::SEC_STGDIR        = "/mnt/secure/staging";
58
59/*
60 * Path to the directory on the media which contains publicly accessable
61 * asec imagefiles. This path will be obscured before the mount is
62 * exposed to non priviledged users.
63 */
64const char *Volume::SEC_STG_SECIMGDIR = "/mnt/secure/staging/.android_secure";
65
66/*
67 * Path to where *only* root can access asec imagefiles
68 */
69const char *Volume::SEC_ASECDIR       = "/mnt/secure/asec";
70
71/*
72 * Path to where secure containers are mounted
73 */
74const char *Volume::ASECDIR           = "/mnt/asec";
75
76static const char *stateToStr(int state) {
77    if (state == Volume::State_Init)
78        return "Initializing";
79    else if (state == Volume::State_NoMedia)
80        return "No-Media";
81    else if (state == Volume::State_Idle)
82        return "Idle-Unmounted";
83    else if (state == Volume::State_Pending)
84        return "Pending";
85    else if (state == Volume::State_Mounted)
86        return "Mounted";
87    else if (state == Volume::State_Unmounting)
88        return "Unmounting";
89    else if (state == Volume::State_Checking)
90        return "Checking";
91    else if (state == Volume::State_Formatting)
92        return "Formatting";
93    else if (state == Volume::State_Shared)
94        return "Shared-Unmounted";
95    else if (state == Volume::State_SharedMnt)
96        return "Shared-Mounted";
97    else
98        return "Unknown-Error";
99}
100
101Volume::Volume(VolumeManager *vm, const char *label, const char *mount_point) {
102    mVm = vm;
103    mDebug = false;
104    mLabel = strdup(label);
105    mMountpoint = strdup(mount_point);
106    mState = Volume::State_Init;
107    mCurrentlyMountedKdev = -1;
108}
109
110Volume::~Volume() {
111    free(mLabel);
112    free(mMountpoint);
113}
114
115void Volume::protectFromAutorunStupidity() {
116    char filename[255];
117
118    snprintf(filename, sizeof(filename), "%s/autorun.inf", SEC_STGDIR);
119    if (!access(filename, F_OK)) {
120        SLOGW("Volume contains an autorun.inf! - removing");
121        /*
122         * Ensure the filename is all lower-case so
123         * the process killer can find the inode.
124         * Probably being paranoid here but meh.
125         */
126        rename(filename, filename);
127        Process::killProcessesWithOpenFiles(filename, 2);
128        if (unlink(filename)) {
129            SLOGE("Failed to remove %s (%s)", filename, strerror(errno));
130        }
131    }
132}
133
134void Volume::setDebug(bool enable) {
135    mDebug = enable;
136}
137
138dev_t Volume::getDiskDevice() {
139    return MKDEV(0, 0);
140};
141
142void Volume::handleVolumeShared() {
143}
144
145void Volume::handleVolumeUnshared() {
146}
147
148int Volume::handleBlockEvent(NetlinkEvent *evt) {
149    errno = ENOSYS;
150    return -1;
151}
152
153void Volume::setState(int state) {
154    char msg[255];
155    int oldState = mState;
156
157    if (oldState == state) {
158        SLOGW("Duplicate state (%d)\n", state);
159        return;
160    }
161
162    mState = state;
163
164    SLOGD("Volume %s state changing %d (%s) -> %d (%s)", mLabel,
165         oldState, stateToStr(oldState), mState, stateToStr(mState));
166    snprintf(msg, sizeof(msg),
167             "Volume %s %s state changed from %d (%s) to %d (%s)", getLabel(),
168             getMountpoint(), oldState, stateToStr(oldState), mState,
169             stateToStr(mState));
170
171    mVm->getBroadcaster()->sendBroadcast(ResponseCode::VolumeStateChange,
172                                         msg, false);
173}
174
175int Volume::createDeviceNode(const char *path, int major, int minor) {
176    mode_t mode = 0660 | S_IFBLK;
177    dev_t dev = (major << 8) | minor;
178    if (mknod(path, mode, dev) < 0) {
179        if (errno != EEXIST) {
180            return -1;
181        }
182    }
183    return 0;
184}
185
186int Volume::formatVol() {
187
188    if (getState() == Volume::State_NoMedia) {
189        errno = ENODEV;
190        return -1;
191    } else if (getState() != Volume::State_Idle) {
192        errno = EBUSY;
193        return -1;
194    }
195
196    if (isMountpointMounted(getMountpoint())) {
197        SLOGW("Volume is idle but appears to be mounted - fixing");
198        setState(Volume::State_Mounted);
199        // mCurrentlyMountedKdev = XXX
200        errno = EBUSY;
201        return -1;
202    }
203
204    char devicePath[255];
205    dev_t diskNode = getDiskDevice();
206    dev_t partNode = MKDEV(MAJOR(diskNode), 1); // XXX: Hmmm
207
208    sprintf(devicePath, "/dev/block/vold/%d:%d",
209            MAJOR(diskNode), MINOR(diskNode));
210
211    if (mDebug) {
212        SLOGI("Formatting volume %s (%s)", getLabel(), devicePath);
213    }
214    setState(Volume::State_Formatting);
215
216    if (initializeMbr(devicePath)) {
217        SLOGE("Failed to initialize MBR (%s)", strerror(errno));
218        goto err;
219    }
220
221    sprintf(devicePath, "/dev/block/vold/%d:%d",
222            MAJOR(partNode), MINOR(partNode));
223
224    if (Fat::format(devicePath, 0)) {
225        SLOGE("Failed to format (%s)", strerror(errno));
226        goto err;
227    }
228
229    setState(Volume::State_Idle);
230    return 0;
231err:
232    return -1;
233}
234
235bool Volume::isMountpointMounted(const char *path) {
236    char device[256];
237    char mount_path[256];
238    char rest[256];
239    FILE *fp;
240    char line[1024];
241
242    if (!(fp = fopen("/proc/mounts", "r"))) {
243        SLOGE("Error opening /proc/mounts (%s)", strerror(errno));
244        return false;
245    }
246
247    while(fgets(line, sizeof(line), fp)) {
248        line[strlen(line)-1] = '\0';
249        sscanf(line, "%255s %255s %255s\n", device, mount_path, rest);
250        if (!strcmp(mount_path, path)) {
251            fclose(fp);
252            return true;
253        }
254
255    }
256
257    fclose(fp);
258    return false;
259}
260
261int Volume::mountVol() {
262    dev_t deviceNodes[4];
263    int n, i, rc = 0;
264    char errmsg[255];
265
266    if (getState() == Volume::State_NoMedia) {
267        snprintf(errmsg, sizeof(errmsg),
268                 "Volume %s %s mount failed - no media",
269                 getLabel(), getMountpoint());
270        mVm->getBroadcaster()->sendBroadcast(
271                                         ResponseCode::VolumeMountFailedNoMedia,
272                                         errmsg, false);
273        errno = ENODEV;
274        return -1;
275    } else if (getState() != Volume::State_Idle) {
276        errno = EBUSY;
277        return -1;
278    }
279
280    if (isMountpointMounted(getMountpoint())) {
281        SLOGW("Volume is idle but appears to be mounted - fixing");
282        setState(Volume::State_Mounted);
283        // mCurrentlyMountedKdev = XXX
284        return 0;
285    }
286
287    n = getDeviceNodes((dev_t *) &deviceNodes, 4);
288    if (!n) {
289        SLOGE("Failed to get device nodes (%s)\n", strerror(errno));
290        return -1;
291    }
292
293    for (i = 0; i < n; i++) {
294        char devicePath[255];
295
296        sprintf(devicePath, "/dev/block/vold/%d:%d", MAJOR(deviceNodes[i]),
297                MINOR(deviceNodes[i]));
298
299        SLOGI("%s being considered for volume %s\n", devicePath, getLabel());
300
301        errno = 0;
302        setState(Volume::State_Checking);
303
304        if (Fat::check(devicePath)) {
305            if (errno == ENODATA) {
306                SLOGW("%s does not contain a FAT filesystem\n", devicePath);
307                continue;
308            }
309            errno = EIO;
310            /* Badness - abort the mount */
311            SLOGE("%s failed FS checks (%s)", devicePath, strerror(errno));
312            setState(Volume::State_Idle);
313            return -1;
314        }
315
316        /*
317         * Mount the device on our internal staging mountpoint so we can
318         * muck with it before exposing it to non priviledged users.
319         */
320        errno = 0;
321        if (Fat::doMount(devicePath, "/mnt/secure/staging", false, false, 1000, 1015, 0702, true)) {
322            SLOGE("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno));
323            continue;
324        }
325
326        SLOGI("Device %s, target %s mounted @ /mnt/secure/staging", devicePath, getMountpoint());
327
328        protectFromAutorunStupidity();
329
330        if (createBindMounts()) {
331            SLOGE("Failed to create bindmounts (%s)", strerror(errno));
332            umount("/mnt/secure/staging");
333            setState(Volume::State_Idle);
334            return -1;
335        }
336
337        /*
338         * Now that the bindmount trickery is done, atomically move the
339         * whole subtree to expose it to non priviledged users.
340         */
341        if (doMoveMount("/mnt/secure/staging", getMountpoint(), false)) {
342            SLOGE("Failed to move mount (%s)", strerror(errno));
343            umount("/mnt/secure/staging");
344            setState(Volume::State_Idle);
345            return -1;
346        }
347        setState(Volume::State_Mounted);
348        mCurrentlyMountedKdev = deviceNodes[i];
349        return 0;
350    }
351
352    SLOGE("Volume %s found no suitable devices for mounting :(\n", getLabel());
353    setState(Volume::State_Idle);
354
355    return -1;
356}
357
358int Volume::createBindMounts() {
359    unsigned long flags;
360
361    /*
362     * Rename old /android_secure -> /.android_secure
363     */
364    if (!access("/mnt/secure/staging/android_secure", R_OK | X_OK) &&
365         access(SEC_STG_SECIMGDIR, R_OK | X_OK)) {
366        if (rename("/mnt/secure/staging/android_secure", SEC_STG_SECIMGDIR)) {
367            SLOGE("Failed to rename legacy asec dir (%s)", strerror(errno));
368        }
369    }
370
371    /*
372     * Ensure that /android_secure exists and is a directory
373     */
374    if (access(SEC_STG_SECIMGDIR, R_OK | X_OK)) {
375        if (errno == ENOENT) {
376            if (mkdir(SEC_STG_SECIMGDIR, 0777)) {
377                SLOGE("Failed to create %s (%s)", SEC_STG_SECIMGDIR, strerror(errno));
378                return -1;
379            }
380        } else {
381            SLOGE("Failed to access %s (%s)", SEC_STG_SECIMGDIR, strerror(errno));
382            return -1;
383        }
384    } else {
385        struct stat sbuf;
386
387        if (stat(SEC_STG_SECIMGDIR, &sbuf)) {
388            SLOGE("Failed to stat %s (%s)", SEC_STG_SECIMGDIR, strerror(errno));
389            return -1;
390        }
391        if (!S_ISDIR(sbuf.st_mode)) {
392            SLOGE("%s is not a directory", SEC_STG_SECIMGDIR);
393            errno = ENOTDIR;
394            return -1;
395        }
396    }
397
398    /*
399     * Bind mount /mnt/secure/staging/android_secure -> /mnt/secure/asec so we'll
400     * have a root only accessable mountpoint for it.
401     */
402    if (mount(SEC_STG_SECIMGDIR, SEC_ASECDIR, "", MS_BIND, NULL)) {
403        SLOGE("Failed to bind mount points %s -> %s (%s)",
404                SEC_STG_SECIMGDIR, SEC_ASECDIR, strerror(errno));
405        return -1;
406    }
407
408    /*
409     * Mount a read-only, zero-sized tmpfs  on <mountpoint>/android_secure to
410     * obscure the underlying directory from everybody - sneaky eh? ;)
411     */
412    if (mount("tmpfs", SEC_STG_SECIMGDIR, "tmpfs", MS_RDONLY, "size=0,mode=000,uid=0,gid=0")) {
413        SLOGE("Failed to obscure %s (%s)", SEC_STG_SECIMGDIR, strerror(errno));
414        umount("/mnt/asec_secure");
415        return -1;
416    }
417
418    return 0;
419}
420
421int Volume::doMoveMount(const char *src, const char *dst, bool force) {
422    unsigned int flags = MS_MOVE;
423    int retries = 5;
424
425    while(retries--) {
426        if (!mount(src, dst, "", flags, NULL)) {
427            if (mDebug) {
428                SLOGD("Moved mount %s -> %s sucessfully", src, dst);
429            }
430            return 0;
431        } else if (errno != EBUSY) {
432            SLOGE("Failed to move mount %s -> %s (%s)", src, dst, strerror(errno));
433            return -1;
434        }
435        int action = 0;
436
437        if (force) {
438            if (retries == 1) {
439                action = 2; // SIGKILL
440            } else if (retries == 2) {
441                action = 1; // SIGHUP
442            }
443        }
444        SLOGW("Failed to move %s -> %s (%s, retries %d, action %d)",
445                src, dst, strerror(errno), retries, action);
446        Process::killProcessesWithOpenFiles(src, action);
447        usleep(1000*250);
448    }
449
450    errno = EBUSY;
451    SLOGE("Giving up on move %s -> %s (%s)", src, dst, strerror(errno));
452    return -1;
453}
454
455int Volume::doUnmount(const char *path, bool force) {
456    int retries = 10;
457
458    if (mDebug) {
459        SLOGD("Unmounting {%s}, force = %d", path, force);
460    }
461
462    while (retries--) {
463        if (!umount(path) || errno == EINVAL || errno == ENOENT) {
464            SLOGI("%s sucessfully unmounted", path);
465            return 0;
466        }
467
468        int action = 0;
469
470        if (force) {
471            if (retries == 1) {
472                action = 2; // SIGKILL
473            } else if (retries == 2) {
474                action = 1; // SIGHUP
475            }
476        }
477
478        SLOGW("Failed to unmount %s (%s, retries %d, action %d)",
479                path, strerror(errno), retries, action);
480
481        Process::killProcessesWithOpenFiles(path, action);
482        usleep(1000*1000);
483    }
484    errno = EBUSY;
485    SLOGE("Giving up on unmount %s (%s)", path, strerror(errno));
486    return -1;
487}
488
489int Volume::unmountVol(bool force) {
490    int i, rc;
491
492    if (getState() != Volume::State_Mounted) {
493        SLOGE("Volume %s unmount request when not mounted", getLabel());
494        errno = EINVAL;
495        return -1;
496    }
497
498    setState(Volume::State_Unmounting);
499    usleep(1000 * 1000); // Give the framework some time to react
500
501    /*
502     * First move the mountpoint back to our internal staging point
503     * so nobody else can muck with it while we work.
504     */
505    if (doMoveMount(getMountpoint(), SEC_STGDIR, force)) {
506        SLOGE("Failed to move mount %s => %s (%s)", getMountpoint(), SEC_STGDIR, strerror(errno));
507        setState(Volume::State_Mounted);
508        return -1;
509    }
510
511    protectFromAutorunStupidity();
512
513    /*
514     * Unmount the tmpfs which was obscuring the asec image directory
515     * from non root users
516     */
517
518    if (doUnmount(Volume::SEC_STG_SECIMGDIR, force)) {
519        SLOGE("Failed to unmount tmpfs on %s (%s)", SEC_STG_SECIMGDIR, strerror(errno));
520        goto fail_republish;
521    }
522
523    /*
524     * Remove the bindmount we were using to keep a reference to
525     * the previously obscured directory.
526     */
527
528    if (doUnmount(Volume::SEC_ASECDIR, force)) {
529        SLOGE("Failed to remove bindmount on %s (%s)", SEC_ASECDIR, strerror(errno));
530        goto fail_remount_tmpfs;
531    }
532
533    /*
534     * Finally, unmount the actual block device from the staging dir
535     */
536    if (doUnmount(Volume::SEC_STGDIR, force)) {
537        SLOGE("Failed to unmount %s (%s)", SEC_STGDIR, strerror(errno));
538        goto fail_recreate_bindmount;
539    }
540
541    SLOGI("%s unmounted sucessfully", getMountpoint());
542
543    setState(Volume::State_Idle);
544    mCurrentlyMountedKdev = -1;
545    return 0;
546
547    /*
548     * Failure handling - try to restore everything back the way it was
549     */
550fail_recreate_bindmount:
551    if (mount(SEC_STG_SECIMGDIR, SEC_ASECDIR, "", MS_BIND, NULL)) {
552        SLOGE("Failed to restore bindmount after failure! - Storage will appear offline!");
553        goto out_nomedia;
554    }
555fail_remount_tmpfs:
556    if (mount("tmpfs", SEC_STG_SECIMGDIR, "tmpfs", MS_RDONLY, "size=0,mode=0,uid=0,gid=0")) {
557        SLOGE("Failed to restore tmpfs after failure! - Storage will appear offline!");
558        goto out_nomedia;
559    }
560fail_republish:
561    if (doMoveMount(SEC_STGDIR, getMountpoint(), force)) {
562        SLOGE("Failed to republish mount after failure! - Storage will appear offline!");
563        goto out_nomedia;
564    }
565
566    setState(Volume::State_Mounted);
567    return -1;
568
569out_nomedia:
570    setState(Volume::State_NoMedia);
571    return -1;
572}
573
574int Volume::initializeMbr(const char *deviceNode) {
575    struct disk_info dinfo;
576
577    memset(&dinfo, 0, sizeof(dinfo));
578
579    if (!(dinfo.part_lst = (struct part_info *) malloc(MAX_NUM_PARTS * sizeof(struct part_info)))) {
580        SLOGE("Failed to malloc prt_lst");
581        return -1;
582    }
583
584    memset(dinfo.part_lst, 0, MAX_NUM_PARTS * sizeof(struct part_info));
585    dinfo.device = strdup(deviceNode);
586    dinfo.scheme = PART_SCHEME_MBR;
587    dinfo.sect_size = 512;
588    dinfo.skip_lba = 2048;
589    dinfo.num_lba = 0;
590    dinfo.num_parts = 1;
591
592    struct part_info *pinfo = &dinfo.part_lst[0];
593
594    pinfo->name = strdup("android_sdcard");
595    pinfo->flags |= PART_ACTIVE_FLAG;
596    pinfo->type = PC_PART_TYPE_FAT32;
597    pinfo->len_kb = -1;
598
599    int rc = apply_disk_config(&dinfo, 0);
600
601    if (rc) {
602        SLOGE("Failed to apply disk configuration (%d)", rc);
603        goto out;
604    }
605
606 out:
607    free(pinfo->name);
608    free(dinfo.device);
609    free(dinfo.part_lst);
610
611    return rc;
612}
613