1/*
2** Copyright 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 <sys/capability.h>
18#include <linux/prctl.h>
19
20#include "installd.h"
21
22
23#define BUFFER_MAX    1024  /* input buffer for commands */
24#define TOKEN_MAX     8     /* max number of arguments in buffer */
25#define REPLY_MAX     256   /* largest reply allowed */
26
27static int do_ping(char **arg, char reply[REPLY_MAX])
28{
29    return 0;
30}
31
32static int do_install(char **arg, char reply[REPLY_MAX])
33{
34    return install(arg[0], atoi(arg[1]), atoi(arg[2]), arg[3]); /* pkgname, uid, gid, seinfo */
35}
36
37static int do_dexopt(char **arg, char reply[REPLY_MAX])
38{
39        /* apk_path, uid, is_public */
40    return dexopt(arg[0], atoi(arg[1]), atoi(arg[2]));
41}
42
43static int do_move_dex(char **arg, char reply[REPLY_MAX])
44{
45    return move_dex(arg[0], arg[1]); /* src, dst */
46}
47
48static int do_rm_dex(char **arg, char reply[REPLY_MAX])
49{
50    return rm_dex(arg[0]); /* pkgname */
51}
52
53static int do_remove(char **arg, char reply[REPLY_MAX])
54{
55    return uninstall(arg[0], atoi(arg[1])); /* pkgname, userid */
56}
57
58static int do_rename(char **arg, char reply[REPLY_MAX])
59{
60    return renamepkg(arg[0], arg[1]); /* oldpkgname, newpkgname */
61}
62
63static int do_fixuid(char **arg, char reply[REPLY_MAX])
64{
65    return fix_uid(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
66}
67
68static int do_free_cache(char **arg, char reply[REPLY_MAX]) /* TODO int:free_size */
69{
70    return free_cache((int64_t)atoll(arg[0])); /* free_size */
71}
72
73static int do_rm_cache(char **arg, char reply[REPLY_MAX])
74{
75    return delete_cache(arg[0], atoi(arg[1])); /* pkgname, userid */
76}
77
78static int do_get_size(char **arg, char reply[REPLY_MAX])
79{
80    int64_t codesize = 0;
81    int64_t datasize = 0;
82    int64_t cachesize = 0;
83    int64_t asecsize = 0;
84    int res = 0;
85
86        /* pkgdir, userid, apkpath */
87    res = get_size(arg[0], atoi(arg[1]), arg[2], arg[3], arg[4], arg[5],
88            &codesize, &datasize, &cachesize, &asecsize);
89
90    /*
91     * Each int64_t can take up 22 characters printed out. Make sure it
92     * doesn't go over REPLY_MAX in the future.
93     */
94    snprintf(reply, REPLY_MAX, "%" PRId64 " %" PRId64 " %" PRId64 " %" PRId64,
95            codesize, datasize, cachesize, asecsize);
96    return res;
97}
98
99static int do_rm_user_data(char **arg, char reply[REPLY_MAX])
100{
101    return delete_user_data(arg[0], atoi(arg[1])); /* pkgname, userid */
102}
103
104static int do_mk_user_data(char **arg, char reply[REPLY_MAX])
105{
106    return make_user_data(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, userid */
107}
108
109static int do_rm_user(char **arg, char reply[REPLY_MAX])
110{
111    return delete_user(atoi(arg[0])); /* userid */
112}
113
114static int do_movefiles(char **arg, char reply[REPLY_MAX])
115{
116    return movefiles();
117}
118
119static int do_linklib(char **arg, char reply[REPLY_MAX])
120{
121    return linklib(arg[0], arg[1], atoi(arg[2]));
122}
123
124struct cmdinfo {
125    const char *name;
126    unsigned numargs;
127    int (*func)(char **arg, char reply[REPLY_MAX]);
128};
129
130struct cmdinfo cmds[] = {
131    { "ping",                 0, do_ping },
132    { "install",              4, do_install },
133    { "dexopt",               3, do_dexopt },
134    { "movedex",              2, do_move_dex },
135    { "rmdex",                1, do_rm_dex },
136    { "remove",               2, do_remove },
137    { "rename",               2, do_rename },
138    { "fixuid",               3, do_fixuid },
139    { "freecache",            1, do_free_cache },
140    { "rmcache",              2, do_rm_cache },
141    { "getsize",              6, do_get_size },
142    { "rmuserdata",           2, do_rm_user_data },
143    { "movefiles",            0, do_movefiles },
144    { "linklib",              3, do_linklib },
145    { "mkuserdata",           3, do_mk_user_data },
146    { "rmuser",               1, do_rm_user },
147};
148
149static int readx(int s, void *_buf, int count)
150{
151    char *buf = _buf;
152    int n = 0, r;
153    if (count < 0) return -1;
154    while (n < count) {
155        r = read(s, buf + n, count - n);
156        if (r < 0) {
157            if (errno == EINTR) continue;
158            ALOGE("read error: %s\n", strerror(errno));
159            return -1;
160        }
161        if (r == 0) {
162            ALOGE("eof\n");
163            return -1; /* EOF */
164        }
165        n += r;
166    }
167    return 0;
168}
169
170static int writex(int s, const void *_buf, int count)
171{
172    const char *buf = _buf;
173    int n = 0, r;
174    if (count < 0) return -1;
175    while (n < count) {
176        r = write(s, buf + n, count - n);
177        if (r < 0) {
178            if (errno == EINTR) continue;
179            ALOGE("write error: %s\n", strerror(errno));
180            return -1;
181        }
182        n += r;
183    }
184    return 0;
185}
186
187
188/* Tokenize the command buffer, locate a matching command,
189 * ensure that the required number of arguments are provided,
190 * call the function(), return the result.
191 */
192static int execute(int s, char cmd[BUFFER_MAX])
193{
194    char reply[REPLY_MAX];
195    char *arg[TOKEN_MAX+1];
196    unsigned i;
197    unsigned n = 0;
198    unsigned short count;
199    int ret = -1;
200
201    // ALOGI("execute('%s')\n", cmd);
202
203        /* default reply is "" */
204    reply[0] = 0;
205
206        /* n is number of args (not counting arg[0]) */
207    arg[0] = cmd;
208    while (*cmd) {
209        if (isspace(*cmd)) {
210            *cmd++ = 0;
211            n++;
212            arg[n] = cmd;
213            if (n == TOKEN_MAX) {
214                ALOGE("too many arguments\n");
215                goto done;
216            }
217        }
218        cmd++;
219    }
220
221    for (i = 0; i < sizeof(cmds) / sizeof(cmds[0]); i++) {
222        if (!strcmp(cmds[i].name,arg[0])) {
223            if (n != cmds[i].numargs) {
224                ALOGE("%s requires %d arguments (%d given)\n",
225                     cmds[i].name, cmds[i].numargs, n);
226            } else {
227                ret = cmds[i].func(arg + 1, reply);
228            }
229            goto done;
230        }
231    }
232    ALOGE("unsupported command '%s'\n", arg[0]);
233
234done:
235    if (reply[0]) {
236        n = snprintf(cmd, BUFFER_MAX, "%d %s", ret, reply);
237    } else {
238        n = snprintf(cmd, BUFFER_MAX, "%d", ret);
239    }
240    if (n > BUFFER_MAX) n = BUFFER_MAX;
241    count = n;
242
243    // ALOGI("reply: '%s'\n", cmd);
244    if (writex(s, &count, sizeof(count))) return -1;
245    if (writex(s, cmd, count)) return -1;
246    return 0;
247}
248
249/**
250 * Initialize all the global variables that are used elsewhere. Returns 0 upon
251 * success and -1 on error.
252 */
253void free_globals() {
254    size_t i;
255
256    for (i = 0; i < android_system_dirs.count; i++) {
257        if (android_system_dirs.dirs[i].path != NULL) {
258            free(android_system_dirs.dirs[i].path);
259        }
260    }
261
262    free(android_system_dirs.dirs);
263}
264
265int initialize_globals() {
266    // Get the android data directory.
267    if (get_path_from_env(&android_data_dir, "ANDROID_DATA") < 0) {
268        return -1;
269    }
270
271    // Get the android app directory.
272    if (copy_and_append(&android_app_dir, &android_data_dir, APP_SUBDIR) < 0) {
273        return -1;
274    }
275
276    // Get the android protected app directory.
277    if (copy_and_append(&android_app_private_dir, &android_data_dir, PRIVATE_APP_SUBDIR) < 0) {
278        return -1;
279    }
280
281    // Get the android app native library directory.
282    if (copy_and_append(&android_app_lib_dir, &android_data_dir, APP_LIB_SUBDIR) < 0) {
283        return -1;
284    }
285
286    // Get the sd-card ASEC mount point.
287    if (get_path_from_env(&android_asec_dir, "ASEC_MOUNTPOINT") < 0) {
288        return -1;
289    }
290
291    // Get the android media directory.
292    if (copy_and_append(&android_media_dir, &android_data_dir, MEDIA_SUBDIR) < 0) {
293        return -1;
294    }
295
296    // Take note of the system and vendor directories.
297    android_system_dirs.count = 2;
298
299    android_system_dirs.dirs = calloc(android_system_dirs.count, sizeof(dir_rec_t));
300    if (android_system_dirs.dirs == NULL) {
301        ALOGE("Couldn't allocate array for dirs; aborting\n");
302        return -1;
303    }
304
305    // system
306    if (get_path_from_env(&android_system_dirs.dirs[0], "ANDROID_ROOT") < 0) {
307        free_globals();
308        return -1;
309    }
310
311    // append "app/" to dirs[0]
312    char *system_app_path = build_string2(android_system_dirs.dirs[0].path, APP_SUBDIR);
313    android_system_dirs.dirs[0].path = system_app_path;
314    android_system_dirs.dirs[0].len = strlen(system_app_path);
315
316    // vendor
317    // TODO replace this with an environment variable (doesn't exist yet)
318    android_system_dirs.dirs[1].path = "/vendor/app/";
319    android_system_dirs.dirs[1].len = strlen(android_system_dirs.dirs[1].path);
320
321    return 0;
322}
323
324int initialize_directories() {
325    int res = -1;
326
327    // Read current filesystem layout version to handle upgrade paths
328    char version_path[PATH_MAX];
329    snprintf(version_path, PATH_MAX, "%s.layout_version", android_data_dir.path);
330
331    int oldVersion;
332    if (fs_read_atomic_int(version_path, &oldVersion) == -1) {
333        oldVersion = 0;
334    }
335    int version = oldVersion;
336
337    // /data/user
338    char *user_data_dir = build_string2(android_data_dir.path, SECONDARY_USER_PREFIX);
339    // /data/data
340    char *legacy_data_dir = build_string2(android_data_dir.path, PRIMARY_USER_PREFIX);
341    // /data/user/0
342    char *primary_data_dir = build_string3(android_data_dir.path, SECONDARY_USER_PREFIX, "0");
343    if (!user_data_dir || !legacy_data_dir || !primary_data_dir) {
344        goto fail;
345    }
346
347    // Make the /data/user directory if necessary
348    if (access(user_data_dir, R_OK) < 0) {
349        if (mkdir(user_data_dir, 0711) < 0) {
350            goto fail;
351        }
352        if (chown(user_data_dir, AID_SYSTEM, AID_SYSTEM) < 0) {
353            goto fail;
354        }
355        if (chmod(user_data_dir, 0711) < 0) {
356            goto fail;
357        }
358    }
359    // Make the /data/user/0 symlink to /data/data if necessary
360    if (access(primary_data_dir, R_OK) < 0) {
361        if (symlink(legacy_data_dir, primary_data_dir)) {
362            goto fail;
363        }
364    }
365
366    if (version == 0) {
367        // Introducing multi-user, so migrate /data/media contents into /data/media/0
368        ALOGD("Upgrading /data/media for multi-user");
369
370        // Ensure /data/media
371        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
372            goto fail;
373        }
374
375        // /data/media.tmp
376        char media_tmp_dir[PATH_MAX];
377        snprintf(media_tmp_dir, PATH_MAX, "%smedia.tmp", android_data_dir.path);
378
379        // Only copy when upgrade not already in progress
380        if (access(media_tmp_dir, F_OK) == -1) {
381            if (rename(android_media_dir.path, media_tmp_dir) == -1) {
382                ALOGE("Failed to move legacy media path: %s", strerror(errno));
383                goto fail;
384            }
385        }
386
387        // Create /data/media again
388        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
389            goto fail;
390        }
391
392        // /data/media/0
393        char owner_media_dir[PATH_MAX];
394        snprintf(owner_media_dir, PATH_MAX, "%s0", android_media_dir.path);
395
396        // Move any owner data into place
397        if (access(media_tmp_dir, F_OK) == 0) {
398            if (rename(media_tmp_dir, owner_media_dir) == -1) {
399                ALOGE("Failed to move owner media path: %s", strerror(errno));
400                goto fail;
401            }
402        }
403
404        // Ensure media directories for any existing users
405        DIR *dir;
406        struct dirent *dirent;
407        char user_media_dir[PATH_MAX];
408
409        dir = opendir(user_data_dir);
410        if (dir != NULL) {
411            while ((dirent = readdir(dir))) {
412                if (dirent->d_type == DT_DIR) {
413                    const char *name = dirent->d_name;
414
415                    // skip "." and ".."
416                    if (name[0] == '.') {
417                        if (name[1] == 0) continue;
418                        if ((name[1] == '.') && (name[2] == 0)) continue;
419                    }
420
421                    // /data/media/<user_id>
422                    snprintf(user_media_dir, PATH_MAX, "%s%s", android_media_dir.path, name);
423                    if (fs_prepare_dir(user_media_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
424                        goto fail;
425                    }
426                }
427            }
428            closedir(dir);
429        }
430
431        version = 1;
432    }
433
434    // /data/media/obb
435    char media_obb_dir[PATH_MAX];
436    snprintf(media_obb_dir, PATH_MAX, "%sobb", android_media_dir.path);
437
438    if (version == 1) {
439        // Introducing /data/media/obb for sharing OBB across users; migrate
440        // any existing OBB files from owner.
441        ALOGD("Upgrading to shared /data/media/obb");
442
443        // /data/media/0/Android/obb
444        char owner_obb_path[PATH_MAX];
445        snprintf(owner_obb_path, PATH_MAX, "%s0/Android/obb", android_media_dir.path);
446
447        // Only move if target doesn't already exist
448        if (access(media_obb_dir, F_OK) != 0 && access(owner_obb_path, F_OK) == 0) {
449            if (rename(owner_obb_path, media_obb_dir) == -1) {
450                ALOGE("Failed to move OBB from owner: %s", strerror(errno));
451                goto fail;
452            }
453        }
454
455        version = 2;
456    }
457
458    if (ensure_media_user_dirs(0) == -1) {
459        ALOGE("Failed to setup media for user 0");
460        goto fail;
461    }
462    if (fs_prepare_dir(media_obb_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
463        goto fail;
464    }
465
466    // Persist layout version if changed
467    if (version != oldVersion) {
468        if (fs_write_atomic_int(version_path, version) == -1) {
469            ALOGE("Failed to save version to %s: %s", version_path, strerror(errno));
470            goto fail;
471        }
472    }
473
474    // Success!
475    res = 0;
476
477fail:
478    free(user_data_dir);
479    free(legacy_data_dir);
480    free(primary_data_dir);
481    return res;
482}
483
484static void drop_privileges() {
485    if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
486        ALOGE("prctl(PR_SET_KEEPCAPS) failed: %s\n", strerror(errno));
487        exit(1);
488    }
489
490    if (setgid(AID_INSTALL) < 0) {
491        ALOGE("setgid() can't drop privileges; exiting.\n");
492        exit(1);
493    }
494
495    if (setuid(AID_INSTALL) < 0) {
496        ALOGE("setuid() can't drop privileges; exiting.\n");
497        exit(1);
498    }
499
500    struct __user_cap_header_struct capheader;
501    struct __user_cap_data_struct capdata[2];
502    memset(&capheader, 0, sizeof(capheader));
503    memset(&capdata, 0, sizeof(capdata));
504    capheader.version = _LINUX_CAPABILITY_VERSION_3;
505    capheader.pid = 0;
506
507    capdata[CAP_TO_INDEX(CAP_DAC_OVERRIDE)].permitted |= CAP_TO_MASK(CAP_DAC_OVERRIDE);
508    capdata[CAP_TO_INDEX(CAP_CHOWN)].permitted        |= CAP_TO_MASK(CAP_CHOWN);
509    capdata[CAP_TO_INDEX(CAP_SETUID)].permitted       |= CAP_TO_MASK(CAP_SETUID);
510    capdata[CAP_TO_INDEX(CAP_SETGID)].permitted       |= CAP_TO_MASK(CAP_SETGID);
511
512    capdata[0].effective = capdata[0].permitted;
513    capdata[1].effective = capdata[1].permitted;
514    capdata[0].inheritable = 0;
515    capdata[1].inheritable = 0;
516
517    if (capset(&capheader, &capdata[0]) < 0) {
518        ALOGE("capset failed: %s\n", strerror(errno));
519        exit(1);
520    }
521}
522
523int main(const int argc, const char *argv[]) {
524    char buf[BUFFER_MAX];
525    struct sockaddr addr;
526    socklen_t alen;
527    int lsocket, s, count;
528
529    ALOGI("installd firing up\n");
530
531    if (initialize_globals() < 0) {
532        ALOGE("Could not initialize globals; exiting.\n");
533        exit(1);
534    }
535
536    if (initialize_directories() < 0) {
537        ALOGE("Could not create directories; exiting.\n");
538        exit(1);
539    }
540
541    drop_privileges();
542
543    lsocket = android_get_control_socket(SOCKET_PATH);
544    if (lsocket < 0) {
545        ALOGE("Failed to get socket from environment: %s\n", strerror(errno));
546        exit(1);
547    }
548    if (listen(lsocket, 5)) {
549        ALOGE("Listen on socket failed: %s\n", strerror(errno));
550        exit(1);
551    }
552    fcntl(lsocket, F_SETFD, FD_CLOEXEC);
553
554    for (;;) {
555        alen = sizeof(addr);
556        s = accept(lsocket, &addr, &alen);
557        if (s < 0) {
558            ALOGE("Accept failed: %s\n", strerror(errno));
559            continue;
560        }
561        fcntl(s, F_SETFD, FD_CLOEXEC);
562
563        ALOGI("new connection\n");
564        for (;;) {
565            unsigned short count;
566            if (readx(s, &count, sizeof(count))) {
567                ALOGE("failed to read size\n");
568                break;
569            }
570            if ((count < 1) || (count >= BUFFER_MAX)) {
571                ALOGE("invalid size %d\n", count);
572                break;
573            }
574            if (readx(s, buf, count)) {
575                ALOGE("failed to read command\n");
576                break;
577            }
578            buf[count] = 0;
579            if (execute(s, buf)) break;
580        }
581        ALOGI("closing connection\n");
582        close(s);
583    }
584
585    return 0;
586}
587