CommandListener.cpp revision 78b524ec463da25d6512dc791112c1335efd497b 
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 <sys/mount.h>
19#include <sys/socket.h>
20#include <sys/stat.h>
21#include <sys/types.h>
22#include <netinet/in.h>
23#include <arpa/inet.h>
24#include <dirent.h>
25#include <errno.h>
26#include <fcntl.h>
27#include <fs_mgr.h>
28#include <stdio.h>
29#include <string.h>
30#include <stdint.h>
31#include <inttypes.h>
32#include <ctype.h>
33
34#define LOG_TAG "VoldCmdListener"
35
36#include <android-base/stringprintf.h>
37#include <cutils/fs.h>
38#include <cutils/log.h>
39
40#include <sysutils/SocketClient.h>
41#include <private/android_filesystem_config.h>
42
43#include "CommandListener.h"
44#include "VolumeManager.h"
45#include "VolumeBase.h"
46#include "ResponseCode.h"
47#include "Process.h"
48#include "Loop.h"
49#include "Devmapper.h"
50#include "MoveTask.h"
51#include "TrimTask.h"
52
53#define DUMP_ARGS 0
54
55CommandListener::CommandListener() :
56                 FrameworkListener("vold", true) {
57    registerCmd(new DumpCmd());
58    registerCmd(new VolumeCmd());
59    registerCmd(new AsecCmd());
60    registerCmd(new ObbCmd());
61    registerCmd(new StorageCmd());
62    registerCmd(new FstrimCmd());
63    registerCmd(new AppFuseCmd());
64}
65
66#if DUMP_ARGS
67void CommandListener::dumpArgs(int argc, char **argv, int argObscure) {
68    char buffer[4096];
69    char *p = buffer;
70
71    memset(buffer, 0, sizeof(buffer));
72    int i;
73    for (i = 0; i < argc; i++) {
74        unsigned int len = strlen(argv[i]) + 1; // Account for space
75        if (i == argObscure) {
76            len += 2; // Account for {}
77        }
78        if (((p - buffer) + len) < (sizeof(buffer)-1)) {
79            if (i == argObscure) {
80                *p++ = '{';
81                *p++ = '}';
82                *p++ = ' ';
83                continue;
84            }
85            strcpy(p, argv[i]);
86            p+= strlen(argv[i]);
87            if (i != (argc -1)) {
88                *p++ = ' ';
89            }
90        }
91    }
92    SLOGD("%s", buffer);
93}
94#else
95void CommandListener::dumpArgs(int /*argc*/, char ** /*argv*/, int /*argObscure*/) { }
96#endif
97
98int CommandListener::sendGenericOkFail(SocketClient *cli, int cond) {
99    if (!cond) {
100        return cli->sendMsg(ResponseCode::CommandOkay, "Command succeeded", false);
101    } else {
102        return cli->sendMsg(ResponseCode::OperationFailed, "Command failed", false);
103    }
104}
105
106CommandListener::DumpCmd::DumpCmd() :
107                 VoldCommand("dump") {
108}
109
110int CommandListener::DumpCmd::runCommand(SocketClient *cli,
111                                         int /*argc*/, char ** /*argv*/) {
112    cli->sendMsg(0, "Dumping loop status", false);
113    if (Loop::dumpState(cli)) {
114        cli->sendMsg(ResponseCode::CommandOkay, "Loop dump failed", true);
115    }
116    cli->sendMsg(0, "Dumping DM status", false);
117    if (Devmapper::dumpState(cli)) {
118        cli->sendMsg(ResponseCode::CommandOkay, "Devmapper dump failed", true);
119    }
120    cli->sendMsg(0, "Dumping mounted filesystems", false);
121    FILE *fp = fopen("/proc/mounts", "r");
122    if (fp) {
123        char line[1024];
124        while (fgets(line, sizeof(line), fp)) {
125            line[strlen(line)-1] = '\0';
126            cli->sendMsg(0, line, false);;
127        }
128        fclose(fp);
129    }
130
131    cli->sendMsg(ResponseCode::CommandOkay, "dump complete", false);
132    return 0;
133}
134
135CommandListener::VolumeCmd::VolumeCmd() :
136                 VoldCommand("volume") {
137}
138
139int CommandListener::VolumeCmd::runCommand(SocketClient *cli,
140                                           int argc, char **argv) {
141    dumpArgs(argc, argv, -1);
142
143    if (argc < 2) {
144        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
145        return 0;
146    }
147
148    VolumeManager *vm = VolumeManager::Instance();
149    std::lock_guard<std::mutex> lock(vm->getLock());
150
151    // TODO: tease out methods not directly related to volumes
152
153    std::string cmd(argv[1]);
154    if (cmd == "reset") {
155        return sendGenericOkFail(cli, vm->reset());
156
157    } else if (cmd == "shutdown") {
158        return sendGenericOkFail(cli, vm->shutdown());
159
160    } else if (cmd == "debug") {
161        return sendGenericOkFail(cli, vm->setDebug(true));
162
163    } else if (cmd == "partition" && argc > 3) {
164        // partition [diskId] [public|private|mixed] [ratio]
165        std::string id(argv[2]);
166        auto disk = vm->findDisk(id);
167        if (disk == nullptr) {
168            return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown disk", false);
169        }
170
171        std::string type(argv[3]);
172        if (type == "public") {
173            return sendGenericOkFail(cli, disk->partitionPublic());
174        } else if (type == "private") {
175            return sendGenericOkFail(cli, disk->partitionPrivate());
176        } else if (type == "mixed") {
177            if (argc < 4) {
178                return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
179            }
180            int frac = atoi(argv[4]);
181            return sendGenericOkFail(cli, disk->partitionMixed(frac));
182        } else {
183            return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
184        }
185
186    } else if (cmd == "mkdirs" && argc > 2) {
187        // mkdirs [path]
188        return sendGenericOkFail(cli, vm->mkdirs(argv[2]));
189
190    } else if (cmd == "user_added" && argc > 3) {
191        // user_added [user] [serial]
192        return sendGenericOkFail(cli, vm->onUserAdded(atoi(argv[2]), atoi(argv[3])));
193
194    } else if (cmd == "user_removed" && argc > 2) {
195        // user_removed [user]
196        return sendGenericOkFail(cli, vm->onUserRemoved(atoi(argv[2])));
197
198    } else if (cmd == "user_started" && argc > 2) {
199        // user_started [user]
200        return sendGenericOkFail(cli, vm->onUserStarted(atoi(argv[2])));
201
202    } else if (cmd == "user_stopped" && argc > 2) {
203        // user_stopped [user]
204        return sendGenericOkFail(cli, vm->onUserStopped(atoi(argv[2])));
205
206    } else if (cmd == "mount" && argc > 2) {
207        // mount [volId] [flags] [user]
208        std::string id(argv[2]);
209        auto vol = vm->findVolume(id);
210        if (vol == nullptr) {
211            return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
212        }
213
214        int mountFlags = (argc > 3) ? atoi(argv[3]) : 0;
215        userid_t mountUserId = (argc > 4) ? atoi(argv[4]) : -1;
216
217        vol->setMountFlags(mountFlags);
218        vol->setMountUserId(mountUserId);
219
220        int res = vol->mount();
221        if (mountFlags & android::vold::VolumeBase::MountFlags::kPrimary) {
222            vm->setPrimary(vol);
223        }
224        return sendGenericOkFail(cli, res);
225
226    } else if (cmd == "unmount" && argc > 2) {
227        // unmount [volId]
228        std::string id(argv[2]);
229        auto vol = vm->findVolume(id);
230        if (vol == nullptr) {
231            return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
232        }
233
234        return sendGenericOkFail(cli, vol->unmount());
235
236    } else if (cmd == "format" && argc > 3) {
237        // format [volId] [fsType|auto]
238        std::string id(argv[2]);
239        std::string fsType(argv[3]);
240        auto vol = vm->findVolume(id);
241        if (vol == nullptr) {
242            return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
243        }
244
245        return sendGenericOkFail(cli, vol->format(fsType));
246
247    } else if (cmd == "move_storage" && argc > 3) {
248        // move_storage [fromVolId] [toVolId]
249        auto fromVol = vm->findVolume(std::string(argv[2]));
250        auto toVol = vm->findVolume(std::string(argv[3]));
251        if (fromVol == nullptr || toVol == nullptr) {
252            return cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown volume", false);
253        }
254
255        (new android::vold::MoveTask(fromVol, toVol))->start();
256        return sendGenericOkFail(cli, 0);
257
258    } else if (cmd == "benchmark" && argc > 2) {
259        // benchmark [volId]
260        std::string id(argv[2]);
261        nsecs_t res = vm->benchmarkPrivate(id);
262        return cli->sendMsg(ResponseCode::CommandOkay,
263                android::base::StringPrintf("%" PRId64, res).c_str(), false);
264
265    } else if (cmd == "forget_partition" && argc > 2) {
266        // forget_partition [partGuid]
267        std::string partGuid(argv[2]);
268        return sendGenericOkFail(cli, vm->forgetPartition(partGuid));
269
270    } else if (cmd == "remount_uid" && argc > 3) {
271        // remount_uid [uid] [none|default|read|write]
272        uid_t uid = atoi(argv[2]);
273        std::string mode(argv[3]);
274        return sendGenericOkFail(cli, vm->remountUid(uid, mode));
275    }
276
277    return cli->sendMsg(ResponseCode::CommandSyntaxError, nullptr, false);
278}
279
280CommandListener::StorageCmd::StorageCmd() :
281                 VoldCommand("storage") {
282}
283
284int CommandListener::StorageCmd::runCommand(SocketClient *cli,
285                                                      int argc, char **argv) {
286    /* Guarantied to be initialized by vold's main() before the CommandListener is active */
287    extern struct fstab *fstab;
288
289    dumpArgs(argc, argv, -1);
290
291    if (argc < 2) {
292        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
293        return 0;
294    }
295
296    if (!strcmp(argv[1], "mountall")) {
297        if (argc != 2) {
298            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: mountall", false);
299            return 0;
300        }
301        fs_mgr_mount_all(fstab);
302        cli->sendMsg(ResponseCode::CommandOkay, "Mountall ran successfully", false);
303        return 0;
304    }
305    if (!strcmp(argv[1], "users")) {
306        DIR *dir;
307        struct dirent *de;
308
309        if (argc < 3) {
310            cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument: user <mountpoint>", false);
311            return 0;
312        }
313        if (!(dir = opendir("/proc"))) {
314            cli->sendMsg(ResponseCode::OperationFailed, "Failed to open /proc", true);
315            return 0;
316        }
317
318        while ((de = readdir(dir))) {
319            int pid = Process::getPid(de->d_name);
320
321            if (pid < 0) {
322                continue;
323            }
324
325            char processName[255];
326            Process::getProcessName(pid, processName, sizeof(processName));
327
328            if (Process::checkFileDescriptorSymLinks(pid, argv[2]) ||
329                Process::checkFileMaps(pid, argv[2]) ||
330                Process::checkSymLink(pid, argv[2], "cwd") ||
331                Process::checkSymLink(pid, argv[2], "root") ||
332                Process::checkSymLink(pid, argv[2], "exe")) {
333
334                char msg[1024];
335                snprintf(msg, sizeof(msg), "%d %s", pid, processName);
336                cli->sendMsg(ResponseCode::StorageUsersListResult, msg, false);
337            }
338        }
339        closedir(dir);
340        cli->sendMsg(ResponseCode::CommandOkay, "Storage user list complete", false);
341    } else {
342        cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown storage cmd", false);
343    }
344    return 0;
345}
346
347CommandListener::AsecCmd::AsecCmd() :
348                 VoldCommand("asec") {
349}
350
351void CommandListener::AsecCmd::listAsecsInDirectory(SocketClient *cli, const char *directory) {
352    DIR *d = opendir(directory);
353
354    if (!d) {
355        cli->sendMsg(ResponseCode::OperationFailed, "Failed to open asec dir", true);
356        return;
357    }
358
359    size_t dirent_len = offsetof(struct dirent, d_name) +
360            fpathconf(dirfd(d), _PC_NAME_MAX) + 1;
361
362    struct dirent *dent = (struct dirent *) malloc(dirent_len);
363    if (dent == NULL) {
364        cli->sendMsg(ResponseCode::OperationFailed, "Failed to allocate memory", true);
365        return;
366    }
367
368    struct dirent *result;
369
370    while (!readdir_r(d, dent, &result) && result != NULL) {
371        if (dent->d_name[0] == '.')
372            continue;
373        if (dent->d_type != DT_REG)
374            continue;
375        size_t name_len = strlen(dent->d_name);
376        if (name_len > 5 && name_len < 260 &&
377                !strcmp(&dent->d_name[name_len - 5], ".asec")) {
378            char id[255];
379            memset(id, 0, sizeof(id));
380            strlcpy(id, dent->d_name, name_len - 4);
381            cli->sendMsg(ResponseCode::AsecListResult, id, false);
382        }
383    }
384    closedir(d);
385
386    free(dent);
387}
388
389int CommandListener::AsecCmd::runCommand(SocketClient *cli,
390                                                      int argc, char **argv) {
391    if (argc < 2) {
392        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
393        return 0;
394    }
395
396    VolumeManager *vm = VolumeManager::Instance();
397    int rc = 0;
398
399    if (!strcmp(argv[1], "list")) {
400        dumpArgs(argc, argv, -1);
401
402        listAsecsInDirectory(cli, VolumeManager::SEC_ASECDIR_EXT);
403        listAsecsInDirectory(cli, VolumeManager::SEC_ASECDIR_INT);
404    } else if (!strcmp(argv[1], "create")) {
405        dumpArgs(argc, argv, 5);
406        if (argc != 8) {
407            cli->sendMsg(ResponseCode::CommandSyntaxError,
408                    "Usage: asec create <container-id> <size_mb> <fstype> <key> <ownerUid> "
409                    "<isExternal>", false);
410            return 0;
411        }
412
413        unsigned long numSectors = (atoi(argv[3]) * (1024 * 1024)) / 512;
414        const bool isExternal = (atoi(argv[7]) == 1);
415        rc = vm->createAsec(argv[2], numSectors, argv[4], argv[5], atoi(argv[6]), isExternal);
416    } else if (!strcmp(argv[1], "resize")) {
417        dumpArgs(argc, argv, -1);
418        if (argc != 5) {
419            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec resize <container-id> <size_mb> <key>", false);
420            return 0;
421        }
422        unsigned long numSectors = (atoi(argv[3]) * (1024 * 1024)) / 512;
423        rc = vm->resizeAsec(argv[2], numSectors, argv[4]);
424    } else if (!strcmp(argv[1], "finalize")) {
425        dumpArgs(argc, argv, -1);
426        if (argc != 3) {
427            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec finalize <container-id>", false);
428            return 0;
429        }
430        rc = vm->finalizeAsec(argv[2]);
431    } else if (!strcmp(argv[1], "fixperms")) {
432        dumpArgs(argc, argv, -1);
433        if  (argc != 5) {
434            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fixperms <container-id> <gid> <filename>", false);
435            return 0;
436        }
437
438        char *endptr;
439        gid_t gid = (gid_t) strtoul(argv[3], &endptr, 10);
440        if (*endptr != '\0') {
441            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fixperms <container-id> <gid> <filename>", false);
442            return 0;
443        }
444
445        rc = vm->fixupAsecPermissions(argv[2], gid, argv[4]);
446    } else if (!strcmp(argv[1], "destroy")) {
447        dumpArgs(argc, argv, -1);
448        if (argc < 3) {
449            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec destroy <container-id> [force]", false);
450            return 0;
451        }
452        bool force = false;
453        if (argc > 3 && !strcmp(argv[3], "force")) {
454            force = true;
455        }
456        rc = vm->destroyAsec(argv[2], force);
457    } else if (!strcmp(argv[1], "mount")) {
458        dumpArgs(argc, argv, 3);
459        if (argc != 6) {
460            cli->sendMsg(ResponseCode::CommandSyntaxError,
461                    "Usage: asec mount <namespace-id> <key> <ownerUid> <ro|rw>", false);
462            return 0;
463        }
464        bool readOnly = true;
465        if (!strcmp(argv[5], "rw")) {
466            readOnly = false;
467        }
468        rc = vm->mountAsec(argv[2], argv[3], atoi(argv[4]), readOnly);
469    } else if (!strcmp(argv[1], "unmount")) {
470        dumpArgs(argc, argv, -1);
471        if (argc < 3) {
472            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec unmount <container-id> [force]", false);
473            return 0;
474        }
475        bool force = false;
476        if (argc > 3 && !strcmp(argv[3], "force")) {
477            force = true;
478        }
479        rc = vm->unmountAsec(argv[2], force);
480    } else if (!strcmp(argv[1], "rename")) {
481        dumpArgs(argc, argv, -1);
482        if (argc != 4) {
483            cli->sendMsg(ResponseCode::CommandSyntaxError,
484                    "Usage: asec rename <old_id> <new_id>", false);
485            return 0;
486        }
487        rc = vm->renameAsec(argv[2], argv[3]);
488    } else if (!strcmp(argv[1], "path")) {
489        dumpArgs(argc, argv, -1);
490        if (argc != 3) {
491            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec path <container-id>", false);
492            return 0;
493        }
494        char path[255];
495
496        if (!(rc = vm->getAsecMountPath(argv[2], path, sizeof(path)))) {
497            cli->sendMsg(ResponseCode::AsecPathResult, path, false);
498            return 0;
499        }
500    } else if (!strcmp(argv[1], "fspath")) {
501        dumpArgs(argc, argv, -1);
502        if (argc != 3) {
503            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: asec fspath <container-id>", false);
504            return 0;
505        }
506        char path[255];
507
508        if (!(rc = vm->getAsecFilesystemPath(argv[2], path, sizeof(path)))) {
509            cli->sendMsg(ResponseCode::AsecPathResult, path, false);
510            return 0;
511        }
512    } else {
513        dumpArgs(argc, argv, -1);
514        cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown asec cmd", false);
515    }
516
517    if (!rc) {
518        cli->sendMsg(ResponseCode::CommandOkay, "asec operation succeeded", false);
519    } else {
520        rc = ResponseCode::convertFromErrno();
521        cli->sendMsg(rc, "asec operation failed", true);
522    }
523
524    return 0;
525}
526
527CommandListener::ObbCmd::ObbCmd() :
528                 VoldCommand("obb") {
529}
530
531int CommandListener::ObbCmd::runCommand(SocketClient *cli,
532                                                      int argc, char **argv) {
533    if (argc < 2) {
534        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
535        return 0;
536    }
537
538    VolumeManager *vm = VolumeManager::Instance();
539    int rc = 0;
540
541    if (!strcmp(argv[1], "list")) {
542        dumpArgs(argc, argv, -1);
543
544        rc = vm->listMountedObbs(cli);
545    } else if (!strcmp(argv[1], "mount")) {
546            dumpArgs(argc, argv, 3);
547            if (argc != 5) {
548                cli->sendMsg(ResponseCode::CommandSyntaxError,
549                        "Usage: obb mount <filename> <key> <ownerGid>", false);
550                return 0;
551            }
552            rc = vm->mountObb(argv[2], argv[3], atoi(argv[4]));
553    } else if (!strcmp(argv[1], "unmount")) {
554        dumpArgs(argc, argv, -1);
555        if (argc < 3) {
556            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: obb unmount <source file> [force]", false);
557            return 0;
558        }
559        bool force = false;
560        if (argc > 3 && !strcmp(argv[3], "force")) {
561            force = true;
562        }
563        rc = vm->unmountObb(argv[2], force);
564    } else if (!strcmp(argv[1], "path")) {
565        dumpArgs(argc, argv, -1);
566        if (argc != 3) {
567            cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: obb path <source file>", false);
568            return 0;
569        }
570        char path[255];
571
572        if (!(rc = vm->getObbMountPath(argv[2], path, sizeof(path)))) {
573            cli->sendMsg(ResponseCode::AsecPathResult, path, false);
574            return 0;
575        }
576    } else {
577        dumpArgs(argc, argv, -1);
578        cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown obb cmd", false);
579    }
580
581    if (!rc) {
582        cli->sendMsg(ResponseCode::CommandOkay, "obb operation succeeded", false);
583    } else {
584        rc = ResponseCode::convertFromErrno();
585        cli->sendMsg(rc, "obb operation failed", true);
586    }
587
588    return 0;
589}
590
591CommandListener::FstrimCmd::FstrimCmd() :
592                 VoldCommand("fstrim") {
593}
594int CommandListener::FstrimCmd::runCommand(SocketClient *cli,
595                                                      int argc, char **argv) {
596    if ((cli->getUid() != 0) && (cli->getUid() != AID_SYSTEM)) {
597        cli->sendMsg(ResponseCode::CommandNoPermission, "No permission to run fstrim commands", false);
598        return 0;
599    }
600
601    if (argc < 2) {
602        cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
603        return 0;
604    }
605
606    VolumeManager *vm = VolumeManager::Instance();
607    std::lock_guard<std::mutex> lock(vm->getLock());
608
609    int flags = 0;
610
611    std::string cmd(argv[1]);
612    if (cmd == "dotrim") {
613        flags = 0;
614    } else if (cmd == "dotrimbench") {
615        flags = android::vold::TrimTask::Flags::kBenchmarkAfter;
616    } else if (cmd == "dodtrim") {
617        flags = android::vold::TrimTask::Flags::kDeepTrim;
618    } else if (cmd == "dodtrimbench") {
619        flags = android::vold::TrimTask::Flags::kDeepTrim
620                | android::vold::TrimTask::Flags::kBenchmarkAfter;
621    }
622
623    (new android::vold::TrimTask(flags))->start();
624    return sendGenericOkFail(cli, 0);
625}
626
627static size_t kAppFuseMaxMountPointName = 32;
628
629static bool isValidAppFuseMountName(const std::string& name) {
630    if (name.size() > kAppFuseMaxMountPointName) {
631        return false;
632    }
633    for (size_t i = 0; i < name.size(); i++) {
634        if (!isalnum(name[i])) {
635            return false;
636        }
637    }
638    return true;
639}
640
641CommandListener::AppFuseCmd::AppFuseCmd() : VoldCommand("appfuse") {}
642
643int CommandListener::AppFuseCmd::runCommand(SocketClient *cli,
644                                            int argc,
645                                            char **argv) {
646    if (argc < 2) {
647        cli->sendMsg(
648            ResponseCode::CommandSyntaxError, "Missing argument", false);
649        return 0;
650    }
651
652    const std::string command(argv[1]);
653
654    if (command == "mount" && argc == 4) {
655        const uid_t uid = atoi(argv[2]);
656        const std::string name(argv[3]);
657
658        // Check mount point name.
659        if (!isValidAppFuseMountName(name)) {
660            return cli->sendMsg(
661                    ResponseCode::CommandParameterError,
662                    "Invalid mount point name.",
663                    false);
664        }
665
666        // Create directories.
667        char path[PATH_MAX];
668        {
669            snprintf(path, PATH_MAX, "/mnt/appfuse/%d_%s", uid, name.c_str());
670            umount2(path, UMOUNT_NOFOLLOW | MNT_DETACH);
671            const int result = android::vold::PrepareDir(path, 0700, 0, 0);
672            if (result != 0) {
673                return sendGenericOkFail(cli, result);
674            }
675        }
676
677        // Open device FD.
678        const int device_fd = open("/dev/fuse", O_RDWR);
679        if (device_fd < 0) {
680            sendGenericOkFail(cli, device_fd);
681            return 0;
682        }
683
684        // Mount.
685        {
686            char opts[256];
687            snprintf(
688                    opts,
689                    sizeof(opts),
690                    "fd=%i,"
691                    "rootmode=40000,"
692                    "default_permissions,"
693                    "user_id=%d,group_id=%d",
694                    device_fd,
695                    uid,
696                    uid);
697            // TODO: Make it bound mount in application namespace.
698            // TODO: Add context= option to opts.
699            const int result = mount(
700                    "/dev/fuse", path, "fuse",
701                    MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts);
702            if (result != 0) {
703                sendGenericOkFail(cli, 1);
704                return 0;
705            }
706        }
707
708        const int result = sendFd(cli, device_fd);
709        close(device_fd);
710        return result;
711    } else if (command == "unmount" && argc == 4) {
712        const uid_t uid = atoi(argv[2]);
713        const std::string name(argv[3]);
714
715        // Check mount point name.
716        if (!isValidAppFuseMountName(name)) {
717            return cli->sendMsg(
718                    ResponseCode::CommandParameterError,
719                    "Invalid mount point name.",
720                    false);
721        }
722
723        // Unmount directory.
724        char path[PATH_MAX];
725        snprintf(path, PATH_MAX, "/mnt/appfuse/%d_%s", uid, name.c_str());
726        umount2(path, UMOUNT_NOFOLLOW | MNT_DETACH);
727
728        return sendGenericOkFail(cli, /* success */ 0);
729    }
730
731    return cli->sendMsg(
732            ResponseCode::CommandSyntaxError,  "Unknown appfuse cmd", false);
733}
734
735int CommandListener::AppFuseCmd::sendFd(SocketClient *cli, int fd) {
736    struct iovec data;
737    char dataBuffer[128];
738    char controlBuffer[CMSG_SPACE(sizeof(int))];
739    struct msghdr message;
740
741    // Message.
742    memset(&message, 0, sizeof(struct msghdr));
743    message.msg_iov = &data;
744    message.msg_iovlen = 1;
745    message.msg_control = controlBuffer;
746    message.msg_controllen = CMSG_SPACE(sizeof(int));
747
748    // Data.
749    data.iov_base = dataBuffer;
750    data.iov_len = snprintf(dataBuffer,
751                            sizeof(dataBuffer),
752                            "200 %d AppFuse command succeeded",
753                            cli->getCmdNum()) + 1;
754
755    // Control.
756    struct cmsghdr* const controlMessage = CMSG_FIRSTHDR(&message);
757    memset(controlBuffer, 0, CMSG_SPACE(sizeof(int)));
758    controlMessage->cmsg_level = SOL_SOCKET;
759    controlMessage->cmsg_type = SCM_RIGHTS;
760    controlMessage->cmsg_len = CMSG_LEN(sizeof(int));
761    *((int *) CMSG_DATA(controlMessage)) = fd;
762
763    return TEMP_FAILURE_RETRY(sendmsg(cli->getSocket(), &message, 0));
764}
765