summaryrefslogtreecommitdiffstats
path: root/cmds/installd/installd.c
blob: 4dd83ae927f41929470fc4950f16ebb86ed4d078 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
/*
** Copyright 2008, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License"); 
** you may not use this file except in compliance with the License. 
** You may obtain a copy of the License at 
**
**     http://www.apache.org/licenses/LICENSE-2.0 
**
** Unless required by applicable law or agreed to in writing, software 
** distributed under the License is distributed on an "AS IS" BASIS, 
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
** See the License for the specific language governing permissions and 
** limitations under the License.
*/

#include <sys/capability.h>
#include <sys/prctl.h>
#include <selinux/android.h>
#include <selinux/avc.h>

#include "installd.h"


#define BUFFER_MAX    1024  /* input buffer for commands */
#define TOKEN_MAX     8     /* max number of arguments in buffer */
#define REPLY_MAX     256   /* largest reply allowed */

static int do_ping(char **arg __unused, char reply[REPLY_MAX] __unused)
{
    return 0;
}

static int do_install(char **arg, char reply[REPLY_MAX] __unused)
{
    return install(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]); /* pkgname, uid, gid, seinfo */
}

static int do_dexopt(char **arg, char reply[REPLY_MAX] __unused)
{
    /* apk_path, uid, is_public, pkgname, instruction_set, vm_safe_mode, should_relocate */
    return dexopt(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3], arg[4], atoi(arg[5]), 0);
}

static int do_mark_boot_complete(char **arg, char reply[REPLY_MAX] __unused)
{
    return mark_boot_complete(arg[0] /* instruction set */);
}

static int do_move_dex(char **arg, char reply[REPLY_MAX] __unused)
{
    return move_dex(arg[0], arg[1], arg[2]); /* src, dst, instruction_set */
}

static int do_rm_dex(char **arg, char reply[REPLY_MAX] __unused)
{
    return rm_dex(arg[0], arg[1]); /* pkgname, instruction_set */
}

static int do_remove(char **arg, char reply[REPLY_MAX] __unused)
{
    return uninstall(arg[0], atoi(arg[1])); /* pkgname, userid */
}

static int do_rename(char **arg, char reply[REPLY_MAX] __unused)
{
    return renamepkg(arg[0], arg[1]); /* oldpkgname, newpkgname */
}

static int do_fixuid(char **arg, char reply[REPLY_MAX] __unused)
{
    return fix_uid(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
}

static int do_free_cache(char **arg, char reply[REPLY_MAX] __unused) /* TODO int:free_size */
{
    return free_cache((int64_t)atoll(arg[0])); /* free_size */
}

static int do_rm_cache(char **arg, char reply[REPLY_MAX] __unused)
{
    return delete_cache(arg[0], atoi(arg[1])); /* pkgname, userid */
}

static int do_rm_code_cache(char **arg, char reply[REPLY_MAX] __unused)
{
    return delete_code_cache(arg[0], atoi(arg[1])); /* pkgname, userid */
}

static int do_get_size(char **arg, char reply[REPLY_MAX])
{
    int64_t codesize = 0;
    int64_t datasize = 0;
    int64_t cachesize = 0;
    int64_t asecsize = 0;
    int res = 0;

        /* pkgdir, userid, apkpath */
    res = get_size(arg[0], atoi(arg[1]), arg[2], arg[3], arg[4], arg[5],
            arg[6], &codesize, &datasize, &cachesize, &asecsize);

    /*
     * Each int64_t can take up 22 characters printed out. Make sure it
     * doesn't go over REPLY_MAX in the future.
     */
    snprintf(reply, REPLY_MAX, "%" PRId64 " %" PRId64 " %" PRId64 " %" PRId64,
            codesize, datasize, cachesize, asecsize);
    return res;
}

static int do_rm_user_data(char **arg, char reply[REPLY_MAX] __unused)
{
    return delete_user_data(arg[0], atoi(arg[1])); /* pkgname, userid */
}

static int do_mk_user_data(char **arg, char reply[REPLY_MAX] __unused)
{
    return make_user_data(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]);
                             /* pkgname, uid, userid, seinfo */
}

static int do_mk_user_config(char **arg, char reply[REPLY_MAX] __unused)
{
    return make_user_config(atoi(arg[0])); /* userid */
}

static int do_rm_user(char **arg, char reply[REPLY_MAX] __unused)
{
    return delete_user(atoi(arg[0])); /* userid */
}

static int do_movefiles(char **arg __unused, char reply[REPLY_MAX] __unused)
{
    return movefiles();
}

static int do_linklib(char **arg, char reply[REPLY_MAX] __unused)
{
    return linklib(arg[0], arg[1], atoi(arg[2]));
}

static int do_idmap(char **arg, char reply[REPLY_MAX] __unused)
{
    return idmap(arg[0], arg[1], atoi(arg[2]));
}

static int do_restorecon_data(char **arg, char reply[REPLY_MAX] __attribute__((unused)))
{
    return restorecon_data(arg[0], arg[1], atoi(arg[2]));
                             /* pkgName, seinfo, uid*/
}

static int do_patchoat(char **arg, char reply[REPLY_MAX] __unused) {
    /* apk_path, uid, is_public, pkgname, instruction_set, vm_safe_mode, should_relocate */
    return dexopt(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3], arg[4], 0, 1);
}

struct cmdinfo {
    const char *name;
    unsigned numargs;
    int (*func)(char **arg, char reply[REPLY_MAX]);
};

struct cmdinfo cmds[] = {
    { "ping",                 0, do_ping },
    { "install",              4, do_install },
    { "dexopt",               6, do_dexopt },
    { "markbootcomplete",     1, do_mark_boot_complete },
    { "movedex",              3, do_move_dex },
    { "rmdex",                2, do_rm_dex },
    { "remove",               2, do_remove },
    { "rename",               2, do_rename },
    { "fixuid",               3, do_fixuid },
    { "freecache",            1, do_free_cache },
    { "rmcache",              2, do_rm_cache },
    { "rmcodecache",          2, do_rm_code_cache },
    { "getsize",              7, do_get_size },
    { "rmuserdata",           2, do_rm_user_data },
    { "movefiles",            0, do_movefiles },
    { "linklib",              3, do_linklib },
    { "mkuserdata",           4, do_mk_user_data },
    { "mkuserconfig",         1, do_mk_user_config },
    { "rmuser",               1, do_rm_user },
    { "idmap",                3, do_idmap },
    { "restorecondata",       3, do_restorecon_data },
    { "patchoat",             5, do_patchoat },
};

static int readx(int s, void *_buf, int count)
{
    char *buf = _buf;
    int n = 0, r;
    if (count < 0) return -1;
    while (n < count) {
        r = read(s, buf + n, count - n);
        if (r < 0) {
            if (errno == EINTR) continue;
            ALOGE("read error: %s\n", strerror(errno));
            return -1;
        }
        if (r == 0) {
            ALOGE("eof\n");
            return -1; /* EOF */
        }
        n += r;
    }
    return 0;
}

static int writex(int s, const void *_buf, int count)
{
    const char *buf = _buf;
    int n = 0, r;
    if (count < 0) return -1;
    while (n < count) {
        r = write(s, buf + n, count - n);
        if (r < 0) {
            if (errno == EINTR) continue;
            ALOGE("write error: %s\n", strerror(errno));
            return -1;
        }
        n += r;
    }
    return 0;
}


/* Tokenize the command buffer, locate a matching command,
 * ensure that the required number of arguments are provided,
 * call the function(), return the result.
 */
static int execute(int s, char cmd[BUFFER_MAX])
{
    char reply[REPLY_MAX];
    char *arg[TOKEN_MAX+1];
    unsigned i;
    unsigned n = 0;
    unsigned short count;
    int ret = -1;

    // ALOGI("execute('%s')\n", cmd);

        /* default reply is "" */
    reply[0] = 0;

        /* n is number of args (not counting arg[0]) */
    arg[0] = cmd;
    while (*cmd) {
        if (isspace(*cmd)) {
            *cmd++ = 0;
            n++;
            arg[n] = cmd;
            if (n == TOKEN_MAX) {
                ALOGE("too many arguments\n");
                goto done;
            }
        }
        if (*cmd) {
          cmd++;
        }
    }

    for (i = 0; i < sizeof(cmds) / sizeof(cmds[0]); i++) {
        if (!strcmp(cmds[i].name,arg[0])) {
            if (n != cmds[i].numargs) {
                ALOGE("%s requires %d arguments (%d given)\n",
                     cmds[i].name, cmds[i].numargs, n);
            } else {
                ret = cmds[i].func(arg + 1, reply);
            }
            goto done;
        }
    }
    ALOGE("unsupported command '%s'\n", arg[0]);

done:
    if (reply[0]) {
        n = snprintf(cmd, BUFFER_MAX, "%d %s", ret, reply);
    } else {
        n = snprintf(cmd, BUFFER_MAX, "%d", ret);
    }
    if (n > BUFFER_MAX) n = BUFFER_MAX;
    count = n;

    // ALOGI("reply: '%s'\n", cmd);
    if (writex(s, &count, sizeof(count))) return -1;
    if (writex(s, cmd, count)) return -1;
    return 0;
}

/**
 * Initialize all the global variables that are used elsewhere. Returns 0 upon
 * success and -1 on error.
 */
void free_globals() {
    size_t i;

    for (i = 0; i < android_system_dirs.count; i++) {
        if (android_system_dirs.dirs[i].path != NULL) {
            free(android_system_dirs.dirs[i].path);
        }
    }

    free(android_system_dirs.dirs);
}

int initialize_globals() {
    // Get the android data directory.
    if (get_path_from_env(&android_data_dir, "ANDROID_DATA") < 0) {
        return -1;
    }

    // Get the android app directory.
    if (copy_and_append(&android_app_dir, &android_data_dir, APP_SUBDIR) < 0) {
        return -1;
    }

    // Get the android protected app directory.
    if (copy_and_append(&android_app_private_dir, &android_data_dir, PRIVATE_APP_SUBDIR) < 0) {
        return -1;
    }

    // Get the android app native library directory.
    if (copy_and_append(&android_app_lib_dir, &android_data_dir, APP_LIB_SUBDIR) < 0) {
        return -1;
    }

    // Get the sd-card ASEC mount point.
    if (get_path_from_env(&android_asec_dir, "ASEC_MOUNTPOINT") < 0) {
        return -1;
    }

    // Get the android media directory.
    if (copy_and_append(&android_media_dir, &android_data_dir, MEDIA_SUBDIR) < 0) {
        return -1;
    }

    // Take note of the system and vendor directories.
    android_system_dirs.count = 4;

    android_system_dirs.dirs = calloc(android_system_dirs.count, sizeof(dir_rec_t));
    if (android_system_dirs.dirs == NULL) {
        ALOGE("Couldn't allocate array for dirs; aborting\n");
        return -1;
    }

    dir_rec_t android_root_dir;
    if (get_path_from_env(&android_root_dir, "ANDROID_ROOT") < 0) {
        ALOGE("Missing ANDROID_ROOT; aborting\n");
        return -1;
    }

    android_system_dirs.dirs[0].path = build_string2(android_root_dir.path, APP_SUBDIR);
    android_system_dirs.dirs[0].len = strlen(android_system_dirs.dirs[0].path);

    android_system_dirs.dirs[1].path = build_string2(android_root_dir.path, PRIV_APP_SUBDIR);
    android_system_dirs.dirs[1].len = strlen(android_system_dirs.dirs[1].path);

    android_system_dirs.dirs[2].path = "/vendor/app/";
    android_system_dirs.dirs[2].len = strlen(android_system_dirs.dirs[2].path);

    android_system_dirs.dirs[3].path = "/oem/app/";
    android_system_dirs.dirs[3].len = strlen(android_system_dirs.dirs[3].path);

    return 0;
}

int initialize_directories() {
    int res = -1;

    // Read current filesystem layout version to handle upgrade paths
    char version_path[PATH_MAX];
    snprintf(version_path, PATH_MAX, "%s.layout_version", android_data_dir.path);

    int oldVersion;
    if (fs_read_atomic_int(version_path, &oldVersion) == -1) {
        oldVersion = 0;
    }
    int version = oldVersion;

    // /data/user
    char *user_data_dir = build_string2(android_data_dir.path, SECONDARY_USER_PREFIX);
    // /data/data
    char *legacy_data_dir = build_string2(android_data_dir.path, PRIMARY_USER_PREFIX);
    // /data/user/0
    char *primary_data_dir = build_string3(android_data_dir.path, SECONDARY_USER_PREFIX, "0");
    if (!user_data_dir || !legacy_data_dir || !primary_data_dir) {
        goto fail;
    }

    // Make the /data/user directory if necessary
    if (access(user_data_dir, R_OK) < 0) {
        if (mkdir(user_data_dir, 0711) < 0) {
            goto fail;
        }
        if (chown(user_data_dir, AID_SYSTEM, AID_SYSTEM) < 0) {
            goto fail;
        }
        if (chmod(user_data_dir, 0711) < 0) {
            goto fail;
        }
    }
    // Make the /data/user/0 symlink to /data/data if necessary
    if (access(primary_data_dir, R_OK) < 0) {
        if (symlink(legacy_data_dir, primary_data_dir)) {
            goto fail;
        }
    }

    if (version == 0) {
        // Introducing multi-user, so migrate /data/media contents into /data/media/0
        ALOGD("Upgrading /data/media for multi-user");

        // Ensure /data/media
        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
            goto fail;
        }

        // /data/media.tmp
        char media_tmp_dir[PATH_MAX];
        snprintf(media_tmp_dir, PATH_MAX, "%smedia.tmp", android_data_dir.path);

        // Only copy when upgrade not already in progress
        if (access(media_tmp_dir, F_OK) == -1) {
            if (rename(android_media_dir.path, media_tmp_dir) == -1) {
                ALOGE("Failed to move legacy media path: %s", strerror(errno));
                goto fail;
            }
        }

        // Create /data/media again
        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
            goto fail;
        }

        if (selinux_android_restorecon(android_media_dir.path, 0)) {
            goto fail;
        }

        // /data/media/0
        char owner_media_dir[PATH_MAX];
        snprintf(owner_media_dir, PATH_MAX, "%s0", android_media_dir.path);

        // Move any owner data into place
        if (access(media_tmp_dir, F_OK) == 0) {
            if (rename(media_tmp_dir, owner_media_dir) == -1) {
                ALOGE("Failed to move owner media path: %s", strerror(errno));
                goto fail;
            }
        }

        // Ensure media directories for any existing users
        DIR *dir;
        struct dirent *dirent;
        char user_media_dir[PATH_MAX];

        dir = opendir(user_data_dir);
        if (dir != NULL) {
            while ((dirent = readdir(dir))) {
                if (dirent->d_type == DT_DIR) {
                    const char *name = dirent->d_name;

                    // skip "." and ".."
                    if (name[0] == '.') {
                        if (name[1] == 0) continue;
                        if ((name[1] == '.') && (name[2] == 0)) continue;
                    }

                    // /data/media/<user_id>
                    snprintf(user_media_dir, PATH_MAX, "%s%s", android_media_dir.path, name);
                    if (fs_prepare_dir(user_media_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
                        goto fail;
                    }
                }
            }
            closedir(dir);
        }

        version = 1;
    }

    // /data/media/obb
    char media_obb_dir[PATH_MAX];
    snprintf(media_obb_dir, PATH_MAX, "%sobb", android_media_dir.path);

    if (version == 1) {
        // Introducing /data/media/obb for sharing OBB across users; migrate
        // any existing OBB files from owner.
        ALOGD("Upgrading to shared /data/media/obb");

        // /data/media/0/Android/obb
        char owner_obb_path[PATH_MAX];
        snprintf(owner_obb_path, PATH_MAX, "%s0/Android/obb", android_media_dir.path);

        // Only move if target doesn't already exist
        if (access(media_obb_dir, F_OK) != 0 && access(owner_obb_path, F_OK) == 0) {
            if (rename(owner_obb_path, media_obb_dir) == -1) {
                ALOGE("Failed to move OBB from owner: %s", strerror(errno));
                goto fail;
            }
        }

        version = 2;
    }

    if (ensure_media_user_dirs(0) == -1) {
        ALOGE("Failed to setup media for user 0");
        goto fail;
    }
    if (fs_prepare_dir(media_obb_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
        goto fail;
    }

    if (ensure_config_user_dirs(0) == -1) {
        ALOGE("Failed to setup misc for user 0");
        goto fail;
    }

    if (version == 2) {
        ALOGD("Upgrading to /data/misc/user directories");

        char misc_dir[PATH_MAX];
        snprintf(misc_dir, PATH_MAX, "%smisc", android_data_dir.path);

        char keychain_added_dir[PATH_MAX];
        snprintf(keychain_added_dir, PATH_MAX, "%s/keychain/cacerts-added", misc_dir);

        char keychain_removed_dir[PATH_MAX];
        snprintf(keychain_removed_dir, PATH_MAX, "%s/keychain/cacerts-removed", misc_dir);

        DIR *dir;
        struct dirent *dirent;
        dir = opendir(user_data_dir);
        if (dir != NULL) {
            while ((dirent = readdir(dir))) {
                const char *name = dirent->d_name;

                // skip "." and ".."
                if (name[0] == '.') {
                    if (name[1] == 0) continue;
                    if ((name[1] == '.') && (name[2] == 0)) continue;
                }

                uint32_t user_id = atoi(name);

                // /data/misc/user/<user_id>
                if (ensure_config_user_dirs(user_id) == -1) {
                    goto fail;
                }

                char misc_added_dir[PATH_MAX];
                snprintf(misc_added_dir, PATH_MAX, "%s/user/%s/cacerts-added", misc_dir, name);

                char misc_removed_dir[PATH_MAX];
                snprintf(misc_removed_dir, PATH_MAX, "%s/user/%s/cacerts-removed", misc_dir, name);

                uid_t uid = multiuser_get_uid(user_id, AID_SYSTEM);
                gid_t gid = uid;
                if (access(keychain_added_dir, F_OK) == 0) {
                    if (copy_dir_files(keychain_added_dir, misc_added_dir, uid, gid) != 0) {
                        ALOGE("Some files failed to copy");
                    }
                }
                if (access(keychain_removed_dir, F_OK) == 0) {
                    if (copy_dir_files(keychain_removed_dir, misc_removed_dir, uid, gid) != 0) {
                        ALOGE("Some files failed to copy");
                    }
                }
            }
            closedir(dir);

            if (access(keychain_added_dir, F_OK) == 0) {
                delete_dir_contents(keychain_added_dir, 1, 0);
            }
            if (access(keychain_removed_dir, F_OK) == 0) {
                delete_dir_contents(keychain_removed_dir, 1, 0);
            }
        }

        version = 3;
    }

    // Persist layout version if changed
    if (version != oldVersion) {
        if (fs_write_atomic_int(version_path, version) == -1) {
            ALOGE("Failed to save version to %s: %s", version_path, strerror(errno));
            goto fail;
        }
    }

    // Success!
    res = 0;

fail:
    free(user_data_dir);
    free(legacy_data_dir);
    free(primary_data_dir);
    return res;
}

static void drop_privileges() {
    if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
        ALOGE("prctl(PR_SET_KEEPCAPS) failed: %s\n", strerror(errno));
        exit(1);
    }

    if (setgid(AID_INSTALL) < 0) {
        ALOGE("setgid() can't drop privileges; exiting.\n");
        exit(1);
    }

    if (setuid(AID_INSTALL) < 0) {
        ALOGE("setuid() can't drop privileges; exiting.\n");
        exit(1);
    }

    struct __user_cap_header_struct capheader;
    struct __user_cap_data_struct capdata[2];
    memset(&capheader, 0, sizeof(capheader));
    memset(&capdata, 0, sizeof(capdata));
    capheader.version = _LINUX_CAPABILITY_VERSION_3;
    capheader.pid = 0;

    capdata[CAP_TO_INDEX(CAP_DAC_OVERRIDE)].permitted |= CAP_TO_MASK(CAP_DAC_OVERRIDE);
    capdata[CAP_TO_INDEX(CAP_CHOWN)].permitted        |= CAP_TO_MASK(CAP_CHOWN);
    capdata[CAP_TO_INDEX(CAP_SETUID)].permitted       |= CAP_TO_MASK(CAP_SETUID);
    capdata[CAP_TO_INDEX(CAP_SETGID)].permitted       |= CAP_TO_MASK(CAP_SETGID);
    capdata[CAP_TO_INDEX(CAP_FOWNER)].permitted       |= CAP_TO_MASK(CAP_FOWNER);

    capdata[0].effective = capdata[0].permitted;
    capdata[1].effective = capdata[1].permitted;
    capdata[0].inheritable = 0;
    capdata[1].inheritable = 0;

    if (capset(&capheader, &capdata[0]) < 0) {
        ALOGE("capset failed: %s\n", strerror(errno));
        exit(1);
    }
}

static int log_callback(int type, const char *fmt, ...) {
    va_list ap;
    int priority;

    switch (type) {
    case SELINUX_WARNING:
        priority = ANDROID_LOG_WARN;
        break;
    case SELINUX_INFO:
        priority = ANDROID_LOG_INFO;
        break;
    default:
        priority = ANDROID_LOG_ERROR;
        break;
    }
    va_start(ap, fmt);
    LOG_PRI_VA(priority, "SELinux", fmt, ap);
    va_end(ap);
    return 0;
}

int main(const int argc __unused, const char *argv[] __unused) {
    char buf[BUFFER_MAX];
    struct sockaddr addr;
    socklen_t alen;
    int lsocket, s;
    int selinux_enabled = (is_selinux_enabled() > 0);

    ALOGI("installd firing up\n");

    union selinux_callback cb;
    cb.func_log = log_callback;
    selinux_set_callback(SELINUX_CB_LOG, cb);

    if (initialize_globals() < 0) {
        ALOGE("Could not initialize globals; exiting.\n");
        exit(1);
    }

    if (initialize_directories() < 0) {
        ALOGE("Could not create directories; exiting.\n");
        exit(1);
    }

    if (selinux_enabled && selinux_status_open(true) < 0) {
        ALOGE("Could not open selinux status; exiting.\n");
        exit(1);
    }

    drop_privileges();

    lsocket = android_get_control_socket(SOCKET_PATH);
    if (lsocket < 0) {
        ALOGE("Failed to get socket from environment: %s\n", strerror(errno));
        exit(1);
    }
    if (listen(lsocket, 5)) {
        ALOGE("Listen on socket failed: %s\n", strerror(errno));
        exit(1);
    }
    fcntl(lsocket, F_SETFD, FD_CLOEXEC);

    for (;;) {
        alen = sizeof(addr);
        s = accept(lsocket, &addr, &alen);
        if (s < 0) {
            ALOGE("Accept failed: %s\n", strerror(errno));
            continue;
        }
        fcntl(s, F_SETFD, FD_CLOEXEC);

        ALOGI("new connection\n");
        for (;;) {
            unsigned short count;
            if (readx(s, &count, sizeof(count))) {
                ALOGE("failed to read size\n");
                break;
            }
            if ((count < 1) || (count >= BUFFER_MAX)) {
                ALOGE("invalid size %d\n", count);
                break;
            }
            if (readx(s, buf, count)) {
                ALOGE("failed to read command\n");
                break;
            }
            buf[count] = 0;
            if (selinux_enabled && selinux_status_updated() > 0) {
                selinux_android_seapp_context_reload();
            }
            if (execute(s, buf)) break;
        }
        ALOGI("closing connection\n");
        close(s);
    }

    return 0;
}