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      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 "installd.h"
     18 
     19 #define CACHE_NOISY(x) //x
     20 
     21 int create_pkg_path_in_dir(char path[PKG_PATH_MAX],
     22                                 const dir_rec_t* dir,
     23                                 const char* pkgname,
     24                                 const char* postfix)
     25 {
     26      const size_t postfix_len = strlen(postfix);
     27 
     28      const size_t pkgname_len = strlen(pkgname);
     29      if (pkgname_len > PKG_NAME_MAX) {
     30          return -1;
     31      }
     32 
     33      if (is_valid_package_name(pkgname) < 0) {
     34          return -1;
     35      }
     36 
     37      if ((pkgname_len + dir->len + postfix_len) >= PKG_PATH_MAX) {
     38          return -1;
     39      }
     40 
     41      char *dst = path;
     42      size_t dst_size = PKG_PATH_MAX;
     43 
     44      if (append_and_increment(&dst, dir->path, &dst_size) < 0
     45              || append_and_increment(&dst, pkgname, &dst_size) < 0
     46              || append_and_increment(&dst, postfix, &dst_size) < 0) {
     47          ALOGE("Error building APK path");
     48          return -1;
     49      }
     50 
     51      return 0;
     52 }
     53 
     54 /**
     55  * Create the package path name for a given package name with a postfix for
     56  * a certain persona. Returns 0 on success, and -1 on failure.
     57  */
     58 int create_pkg_path(char path[PKG_PATH_MAX],
     59                     const char *pkgname,
     60                     const char *postfix,
     61                     uid_t persona)
     62 {
     63     size_t uid_len;
     64     char* persona_prefix;
     65     if (persona == 0) {
     66         persona_prefix = PRIMARY_USER_PREFIX;
     67         uid_len = 0;
     68     } else {
     69         persona_prefix = SECONDARY_USER_PREFIX;
     70         uid_len = snprintf(NULL, 0, "%d", persona);
     71     }
     72 
     73     const size_t prefix_len = android_data_dir.len + strlen(persona_prefix) + uid_len + 1 /*slash*/;
     74     char prefix[prefix_len + 1];
     75 
     76     char *dst = prefix;
     77     size_t dst_size = sizeof(prefix);
     78 
     79     if (append_and_increment(&dst, android_data_dir.path, &dst_size) < 0
     80             || append_and_increment(&dst, persona_prefix, &dst_size) < 0) {
     81         ALOGE("Error building prefix for APK path");
     82         return -1;
     83     }
     84 
     85     if (persona != 0) {
     86         int ret = snprintf(dst, dst_size, "%d/", persona);
     87         if (ret < 0 || (size_t) ret != uid_len + 1) {
     88             ALOGW("Error appending UID to APK path");
     89             return -1;
     90         }
     91     }
     92 
     93     dir_rec_t dir;
     94     dir.path = prefix;
     95     dir.len = prefix_len;
     96 
     97     return create_pkg_path_in_dir(path, &dir, pkgname, postfix);
     98 }
     99 
    100 /**
    101  * Create the path name for user data for a certain persona.
    102  * Returns 0 on success, and -1 on failure.
    103  */
    104 int create_persona_path(char path[PKG_PATH_MAX],
    105                     uid_t persona)
    106 {
    107     size_t uid_len;
    108     char* persona_prefix;
    109     if (persona == 0) {
    110         persona_prefix = PRIMARY_USER_PREFIX;
    111         uid_len = 0;
    112     } else {
    113         persona_prefix = SECONDARY_USER_PREFIX;
    114         uid_len = snprintf(NULL, 0, "%d/", persona);
    115     }
    116 
    117     char *dst = path;
    118     size_t dst_size = PKG_PATH_MAX;
    119 
    120     if (append_and_increment(&dst, android_data_dir.path, &dst_size) < 0
    121             || append_and_increment(&dst, persona_prefix, &dst_size) < 0) {
    122         ALOGE("Error building prefix for user path");
    123         return -1;
    124     }
    125 
    126     if (persona != 0) {
    127         if (dst_size < uid_len + 1) {
    128             ALOGE("Error building user path");
    129             return -1;
    130         }
    131         int ret = snprintf(dst, dst_size, "%d/", persona);
    132         if (ret < 0 || (size_t) ret != uid_len) {
    133             ALOGE("Error appending persona id to path");
    134             return -1;
    135         }
    136     }
    137     return 0;
    138 }
    139 
    140 /**
    141  * Create the path name for media for a certain persona.
    142  * Returns 0 on success, and -1 on failure.
    143  */
    144 int create_persona_media_path(char path[PATH_MAX], userid_t userid) {
    145     if (snprintf(path, PATH_MAX, "%s%d", android_media_dir.path, userid) > PATH_MAX) {
    146         return -1;
    147     }
    148     return 0;
    149 }
    150 
    151 int create_move_path(char path[PKG_PATH_MAX],
    152     const char* pkgname,
    153     const char* leaf,
    154     uid_t persona)
    155 {
    156     if ((android_data_dir.len + strlen(PRIMARY_USER_PREFIX) + strlen(pkgname) + strlen(leaf) + 1)
    157             >= PKG_PATH_MAX) {
    158         return -1;
    159     }
    160 
    161     sprintf(path, "%s%s%s/%s", android_data_dir.path, PRIMARY_USER_PREFIX, pkgname, leaf);
    162     return 0;
    163 }
    164 
    165 /**
    166  * Checks whether the package name is valid. Returns -1 on error and
    167  * 0 on success.
    168  */
    169 int is_valid_package_name(const char* pkgname) {
    170     const char *x = pkgname;
    171     int alpha = -1;
    172 
    173     while (*x) {
    174         if (isalnum(*x) || (*x == '_')) {
    175                 /* alphanumeric or underscore are fine */
    176         } else if (*x == '.') {
    177             if ((x == pkgname) || (x[1] == '.') || (x[1] == 0)) {
    178                     /* periods must not be first, last, or doubled */
    179                 ALOGE("invalid package name '%s'\n", pkgname);
    180                 return -1;
    181             }
    182         } else if (*x == '-') {
    183             /* Suffix -X is fine to let versioning of packages.
    184                But whatever follows should be alphanumeric.*/
    185             alpha = 1;
    186         } else {
    187                 /* anything not A-Z, a-z, 0-9, _, or . is invalid */
    188             ALOGE("invalid package name '%s'\n", pkgname);
    189             return -1;
    190         }
    191 
    192         x++;
    193     }
    194 
    195     if (alpha == 1) {
    196         // Skip current character
    197         x++;
    198         while (*x) {
    199             if (!isalnum(*x)) {
    200                 ALOGE("invalid package name '%s' should include only numbers after -\n", pkgname);
    201                 return -1;
    202             }
    203             x++;
    204         }
    205     }
    206 
    207     return 0;
    208 }
    209 
    210 static int _delete_dir_contents(DIR *d, const char *ignore)
    211 {
    212     int result = 0;
    213     struct dirent *de;
    214     int dfd;
    215 
    216     dfd = dirfd(d);
    217 
    218     if (dfd < 0) return -1;
    219 
    220     while ((de = readdir(d))) {
    221         const char *name = de->d_name;
    222 
    223             /* skip the ignore name if provided */
    224         if (ignore && !strcmp(name, ignore)) continue;
    225 
    226         if (de->d_type == DT_DIR) {
    227             int r, subfd;
    228             DIR *subdir;
    229 
    230                 /* always skip "." and ".." */
    231             if (name[0] == '.') {
    232                 if (name[1] == 0) continue;
    233                 if ((name[1] == '.') && (name[2] == 0)) continue;
    234             }
    235 
    236             subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
    237             if (subfd < 0) {
    238                 ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
    239                 result = -1;
    240                 continue;
    241             }
    242             subdir = fdopendir(subfd);
    243             if (subdir == NULL) {
    244                 ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
    245                 close(subfd);
    246                 result = -1;
    247                 continue;
    248             }
    249             if (_delete_dir_contents(subdir, 0)) {
    250                 result = -1;
    251             }
    252             closedir(subdir);
    253             if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
    254                 ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
    255                 result = -1;
    256             }
    257         } else {
    258             if (unlinkat(dfd, name, 0) < 0) {
    259                 ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
    260                 result = -1;
    261             }
    262         }
    263     }
    264 
    265     return result;
    266 }
    267 
    268 int delete_dir_contents(const char *pathname,
    269                         int also_delete_dir,
    270                         const char *ignore)
    271 {
    272     int res = 0;
    273     DIR *d;
    274 
    275     d = opendir(pathname);
    276     if (d == NULL) {
    277         ALOGE("Couldn't opendir %s: %s\n", pathname, strerror(errno));
    278         return -errno;
    279     }
    280     res = _delete_dir_contents(d, ignore);
    281     closedir(d);
    282     if (also_delete_dir) {
    283         if (rmdir(pathname)) {
    284             ALOGE("Couldn't rmdir %s: %s\n", pathname, strerror(errno));
    285             res = -1;
    286         }
    287     }
    288     return res;
    289 }
    290 
    291 int delete_dir_contents_fd(int dfd, const char *name)
    292 {
    293     int fd, res;
    294     DIR *d;
    295 
    296     fd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
    297     if (fd < 0) {
    298         ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
    299         return -1;
    300     }
    301     d = fdopendir(fd);
    302     if (d == NULL) {
    303         ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
    304         close(fd);
    305         return -1;
    306     }
    307     res = _delete_dir_contents(d, 0);
    308     closedir(d);
    309     return res;
    310 }
    311 
    312 int lookup_media_dir(char basepath[PATH_MAX], const char *dir)
    313 {
    314     DIR *d;
    315     struct dirent *de;
    316     struct stat s;
    317     char* dirpos = basepath + strlen(basepath);
    318 
    319     if ((*(dirpos-1)) != '/') {
    320         *dirpos = '/';
    321         dirpos++;
    322     }
    323 
    324     CACHE_NOISY(ALOGI("Looking up %s in %s\n", dir, basepath));
    325     // Verify the path won't extend beyond our buffer, to avoid
    326     // repeated checking later.
    327     if ((dirpos-basepath+strlen(dir)) >= (PATH_MAX-1)) {
    328         ALOGW("Path exceeds limit: %s%s", basepath, dir);
    329         return -1;
    330     }
    331 
    332     // First, can we find this directory with the case that is given?
    333     strcpy(dirpos, dir);
    334     if (stat(basepath, &s) >= 0) {
    335         CACHE_NOISY(ALOGI("Found direct: %s\n", basepath));
    336         return 0;
    337     }
    338 
    339     // Not found with that case...  search through all entries to find
    340     // one that matches regardless of case.
    341     *dirpos = 0;
    342 
    343     d = opendir(basepath);
    344     if (d == NULL) {
    345         return -1;
    346     }
    347 
    348     while ((de = readdir(d))) {
    349         if (strcasecmp(de->d_name, dir) == 0) {
    350             strcpy(dirpos, de->d_name);
    351             closedir(d);
    352             CACHE_NOISY(ALOGI("Found search: %s\n", basepath));
    353             return 0;
    354         }
    355     }
    356 
    357     ALOGW("Couldn't find %s in %s", dir, basepath);
    358     closedir(d);
    359     return -1;
    360 }
    361 
    362 int64_t data_disk_free()
    363 {
    364     struct statfs sfs;
    365     if (statfs(android_data_dir.path, &sfs) == 0) {
    366         return sfs.f_bavail * sfs.f_bsize;
    367     } else {
    368         ALOGE("Couldn't statfs %s: %s\n", android_data_dir.path, strerror(errno));
    369         return -1;
    370     }
    371 }
    372 
    373 cache_t* start_cache_collection()
    374 {
    375     cache_t* cache = (cache_t*)calloc(1, sizeof(cache_t));
    376     return cache;
    377 }
    378 
    379 #define CACHE_BLOCK_SIZE (512*1024)
    380 
    381 static void* _cache_malloc(cache_t* cache, size_t len)
    382 {
    383     len = (len+3)&~3;
    384     if (len > (CACHE_BLOCK_SIZE/2)) {
    385         // It doesn't make sense to try to put this allocation into one
    386         // of our blocks, because it is so big.  Instead, make a new dedicated
    387         // block for it.
    388         int8_t* res = (int8_t*)malloc(len+sizeof(void*));
    389         if (res == NULL) {
    390             return NULL;
    391         }
    392         CACHE_NOISY(ALOGI("Allocated large cache mem block: %p size %d", res, len));
    393         // Link it into our list of blocks, not disrupting the current one.
    394         if (cache->memBlocks == NULL) {
    395             *(void**)res = NULL;
    396             cache->memBlocks = res;
    397         } else {
    398             *(void**)res = *(void**)cache->memBlocks;
    399             *(void**)cache->memBlocks = res;
    400         }
    401         return res + sizeof(void*);
    402     }
    403     int8_t* res = cache->curMemBlockAvail;
    404     int8_t* nextPos = res + len;
    405     if (cache->memBlocks == NULL || nextPos > cache->curMemBlockEnd) {
    406         int8_t* newBlock = malloc(CACHE_BLOCK_SIZE);
    407         if (newBlock == NULL) {
    408             return NULL;
    409         }
    410         CACHE_NOISY(ALOGI("Allocated new cache mem block: %p", newBlock));
    411         *(void**)newBlock = cache->memBlocks;
    412         cache->memBlocks = newBlock;
    413         res = cache->curMemBlockAvail = newBlock + sizeof(void*);
    414         cache->curMemBlockEnd = newBlock + CACHE_BLOCK_SIZE;
    415         nextPos = res + len;
    416     }
    417     CACHE_NOISY(ALOGI("cache_malloc: ret %p size %d, block=%p, nextPos=%p",
    418             res, len, cache->memBlocks, nextPos));
    419     cache->curMemBlockAvail = nextPos;
    420     return res;
    421 }
    422 
    423 static void* _cache_realloc(cache_t* cache, void* cur, size_t origLen, size_t len)
    424 {
    425     // This isn't really a realloc, but it is good enough for our purposes here.
    426     void* alloc = _cache_malloc(cache, len);
    427     if (alloc != NULL && cur != NULL) {
    428         memcpy(alloc, cur, origLen < len ? origLen : len);
    429     }
    430     return alloc;
    431 }
    432 
    433 static void _inc_num_cache_collected(cache_t* cache)
    434 {
    435     cache->numCollected++;
    436     if ((cache->numCollected%20000) == 0) {
    437         ALOGI("Collected cache so far: %d directories, %d files",
    438             cache->numDirs, cache->numFiles);
    439     }
    440 }
    441 
    442 static cache_dir_t* _add_cache_dir_t(cache_t* cache, cache_dir_t* parent, const char *name)
    443 {
    444     size_t nameLen = strlen(name);
    445     cache_dir_t* dir = (cache_dir_t*)_cache_malloc(cache, sizeof(cache_dir_t)+nameLen+1);
    446     if (dir != NULL) {
    447         dir->parent = parent;
    448         dir->childCount = 0;
    449         dir->hiddenCount = 0;
    450         dir->deleted = 0;
    451         strcpy(dir->name, name);
    452         if (cache->numDirs >= cache->availDirs) {
    453             size_t newAvail = cache->availDirs < 1000 ? 1000 : cache->availDirs*2;
    454             cache_dir_t** newDirs = (cache_dir_t**)_cache_realloc(cache, cache->dirs,
    455                     cache->availDirs*sizeof(cache_dir_t*), newAvail*sizeof(cache_dir_t*));
    456             if (newDirs == NULL) {
    457                 ALOGE("Failure growing cache dirs array for %s\n", name);
    458                 return NULL;
    459             }
    460             cache->availDirs = newAvail;
    461             cache->dirs = newDirs;
    462         }
    463         cache->dirs[cache->numDirs] = dir;
    464         cache->numDirs++;
    465         if (parent != NULL) {
    466             parent->childCount++;
    467         }
    468         _inc_num_cache_collected(cache);
    469     } else {
    470         ALOGE("Failure allocating cache_dir_t for %s\n", name);
    471     }
    472     return dir;
    473 }
    474 
    475 static cache_file_t* _add_cache_file_t(cache_t* cache, cache_dir_t* dir, time_t modTime,
    476         const char *name)
    477 {
    478     size_t nameLen = strlen(name);
    479     cache_file_t* file = (cache_file_t*)_cache_malloc(cache, sizeof(cache_file_t)+nameLen+1);
    480     if (file != NULL) {
    481         file->dir = dir;
    482         file->modTime = modTime;
    483         strcpy(file->name, name);
    484         if (cache->numFiles >= cache->availFiles) {
    485             size_t newAvail = cache->availFiles < 1000 ? 1000 : cache->availFiles*2;
    486             cache_file_t** newFiles = (cache_file_t**)_cache_realloc(cache, cache->files,
    487                     cache->availFiles*sizeof(cache_file_t*), newAvail*sizeof(cache_file_t*));
    488             if (newFiles == NULL) {
    489                 ALOGE("Failure growing cache file array for %s\n", name);
    490                 return NULL;
    491             }
    492             cache->availFiles = newAvail;
    493             cache->files = newFiles;
    494         }
    495         CACHE_NOISY(ALOGI("Setting file %p at position %d in array %p", file,
    496                 cache->numFiles, cache->files));
    497         cache->files[cache->numFiles] = file;
    498         cache->numFiles++;
    499         dir->childCount++;
    500         _inc_num_cache_collected(cache);
    501     } else {
    502         ALOGE("Failure allocating cache_file_t for %s\n", name);
    503     }
    504     return file;
    505 }
    506 
    507 static int _add_cache_files(cache_t *cache, cache_dir_t *parentDir, const char *dirName,
    508         DIR* dir, char *pathBase, char *pathPos, size_t pathAvailLen)
    509 {
    510     struct dirent *de;
    511     cache_dir_t* cacheDir = NULL;
    512     int dfd;
    513 
    514     CACHE_NOISY(ALOGI("_add_cache_files: parent=%p dirName=%s dir=%p pathBase=%s",
    515             parentDir, dirName, dir, pathBase));
    516 
    517     dfd = dirfd(dir);
    518 
    519     if (dfd < 0) return 0;
    520 
    521     // Sub-directories always get added to the data structure, so if they
    522     // are empty we will know about them to delete them later.
    523     cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
    524 
    525     while ((de = readdir(dir))) {
    526         const char *name = de->d_name;
    527 
    528         if (de->d_type == DT_DIR) {
    529             int subfd;
    530             DIR *subdir;
    531 
    532                 /* always skip "." and ".." */
    533             if (name[0] == '.') {
    534                 if (name[1] == 0) continue;
    535                 if ((name[1] == '.') && (name[2] == 0)) continue;
    536             }
    537 
    538             subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
    539             if (subfd < 0) {
    540                 ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
    541                 continue;
    542             }
    543             subdir = fdopendir(subfd);
    544             if (subdir == NULL) {
    545                 ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
    546                 close(subfd);
    547                 continue;
    548             }
    549             if (cacheDir == NULL) {
    550                 cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
    551             }
    552             if (cacheDir != NULL) {
    553                 // Update pathBase for the new path...  this may change dirName
    554                 // if that is also pointing to the path, but we are done with it
    555                 // now.
    556                 size_t finallen = snprintf(pathPos, pathAvailLen, "/%s", name);
    557                 CACHE_NOISY(ALOGI("Collecting dir %s\n", pathBase));
    558                 if (finallen < pathAvailLen) {
    559                     _add_cache_files(cache, cacheDir, name, subdir, pathBase,
    560                             pathPos+finallen, pathAvailLen-finallen);
    561                 } else {
    562                     // Whoops, the final path is too long!  We'll just delete
    563                     // this directory.
    564                     ALOGW("Cache dir %s truncated in path %s; deleting dir\n",
    565                             name, pathBase);
    566                     _delete_dir_contents(subdir, NULL);
    567                     if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
    568                         ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
    569                     }
    570                 }
    571             }
    572             closedir(subdir);
    573         } else if (de->d_type == DT_REG) {
    574             // Skip files that start with '.'; they will be deleted if
    575             // their entire directory is deleted.  This allows for metadata
    576             // like ".nomedia" to remain in the directory until the entire
    577             // directory is deleted.
    578             if (cacheDir == NULL) {
    579                 cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
    580             }
    581             if (name[0] == '.') {
    582                 cacheDir->hiddenCount++;
    583                 continue;
    584             }
    585             if (cacheDir != NULL) {
    586                 // Build final full path for file...  this may change dirName
    587                 // if that is also pointing to the path, but we are done with it
    588                 // now.
    589                 size_t finallen = snprintf(pathPos, pathAvailLen, "/%s", name);
    590                 CACHE_NOISY(ALOGI("Collecting file %s\n", pathBase));
    591                 if (finallen < pathAvailLen) {
    592                     struct stat s;
    593                     if (stat(pathBase, &s) >= 0) {
    594                         _add_cache_file_t(cache, cacheDir, s.st_mtime, name);
    595                     } else {
    596                         ALOGW("Unable to stat cache file %s; deleting\n", pathBase);
    597                         if (unlink(pathBase) < 0) {
    598                             ALOGE("Couldn't unlink %s: %s\n", pathBase, strerror(errno));
    599                         }
    600                     }
    601                 } else {
    602                     // Whoops, the final path is too long!  We'll just delete
    603                     // this file.
    604                     ALOGW("Cache file %s truncated in path %s; deleting\n",
    605                             name, pathBase);
    606                     if (unlinkat(dfd, name, 0) < 0) {
    607                         *pathPos = 0;
    608                         ALOGE("Couldn't unlinkat %s in %s: %s\n", name, pathBase,
    609                                 strerror(errno));
    610                     }
    611                 }
    612             }
    613         } else {
    614             cacheDir->hiddenCount++;
    615         }
    616     }
    617     return 0;
    618 }
    619 
    620 void add_cache_files(cache_t* cache, const char *basepath, const char *cachedir)
    621 {
    622     DIR *d;
    623     struct dirent *de;
    624     char dirname[PATH_MAX];
    625 
    626     CACHE_NOISY(ALOGI("add_cache_files: base=%s cachedir=%s\n", basepath, cachedir));
    627 
    628     d = opendir(basepath);
    629     if (d == NULL) {
    630         return;
    631     }
    632 
    633     while ((de = readdir(d))) {
    634         if (de->d_type == DT_DIR) {
    635             DIR* subdir;
    636             const char *name = de->d_name;
    637             char* pathpos;
    638 
    639                 /* always skip "." and ".." */
    640             if (name[0] == '.') {
    641                 if (name[1] == 0) continue;
    642                 if ((name[1] == '.') && (name[2] == 0)) continue;
    643             }
    644 
    645             strcpy(dirname, basepath);
    646             pathpos = dirname + strlen(dirname);
    647             if ((*(pathpos-1)) != '/') {
    648                 *pathpos = '/';
    649                 pathpos++;
    650                 *pathpos = 0;
    651             }
    652             if (cachedir != NULL) {
    653                 snprintf(pathpos, sizeof(dirname)-(pathpos-dirname), "%s/%s", name, cachedir);
    654             } else {
    655                 snprintf(pathpos, sizeof(dirname)-(pathpos-dirname), "%s", name);
    656             }
    657             CACHE_NOISY(ALOGI("Adding cache files from dir: %s\n", dirname));
    658             subdir = opendir(dirname);
    659             if (subdir != NULL) {
    660                 size_t dirnameLen = strlen(dirname);
    661                 _add_cache_files(cache, NULL, dirname, subdir, dirname, dirname+dirnameLen,
    662                         PATH_MAX - dirnameLen);
    663                 closedir(subdir);
    664             }
    665         }
    666     }
    667 
    668     closedir(d);
    669 }
    670 
    671 static char *create_dir_path(char path[PATH_MAX], cache_dir_t* dir)
    672 {
    673     char *pos = path;
    674     if (dir->parent != NULL) {
    675         pos = create_dir_path(path, dir->parent);
    676     }
    677     // Note that we don't need to worry about going beyond the buffer,
    678     // since when we were constructing the cache entries our maximum
    679     // buffer size for full paths was PATH_MAX.
    680     strcpy(pos, dir->name);
    681     pos += strlen(pos);
    682     *pos = '/';
    683     pos++;
    684     *pos = 0;
    685     return pos;
    686 }
    687 
    688 static void delete_cache_dir(char path[PATH_MAX], cache_dir_t* dir)
    689 {
    690     if (dir->parent != NULL) {
    691         create_dir_path(path, dir);
    692         ALOGI("DEL DIR %s\n", path);
    693         if (dir->hiddenCount <= 0) {
    694             if (rmdir(path)) {
    695                 ALOGE("Couldn't rmdir %s: %s\n", path, strerror(errno));
    696                 return;
    697             }
    698         } else {
    699             // The directory contains hidden files so we need to delete
    700             // them along with the directory itself.
    701             if (delete_dir_contents(path, 1, NULL)) {
    702                 return;
    703             }
    704         }
    705         dir->parent->childCount--;
    706         dir->deleted = 1;
    707         if (dir->parent->childCount <= 0) {
    708             delete_cache_dir(path, dir->parent);
    709         }
    710     } else if (dir->hiddenCount > 0) {
    711         // This is a root directory, but it has hidden files.  Get rid of
    712         // all of those files, but not the directory itself.
    713         create_dir_path(path, dir);
    714         ALOGI("DEL CONTENTS %s\n", path);
    715         delete_dir_contents(path, 0, NULL);
    716     }
    717 }
    718 
    719 static int cache_modtime_sort(const void *lhsP, const void *rhsP)
    720 {
    721     const cache_file_t *lhs = *(const cache_file_t**)lhsP;
    722     const cache_file_t *rhs = *(const cache_file_t**)rhsP;
    723     return lhs->modTime < rhs->modTime ? -1 : (lhs->modTime > rhs->modTime ? 1 : 0);
    724 }
    725 
    726 void clear_cache_files(cache_t* cache, int64_t free_size)
    727 {
    728     size_t i;
    729     int skip = 0;
    730     char path[PATH_MAX];
    731 
    732     ALOGI("Collected cache files: %d directories, %d files",
    733         cache->numDirs, cache->numFiles);
    734 
    735     CACHE_NOISY(ALOGI("Sorting files..."));
    736     qsort(cache->files, cache->numFiles, sizeof(cache_file_t*),
    737             cache_modtime_sort);
    738 
    739     CACHE_NOISY(ALOGI("Cleaning empty directories..."));
    740     for (i=cache->numDirs; i>0; i--) {
    741         cache_dir_t* dir = cache->dirs[i-1];
    742         if (dir->childCount <= 0 && !dir->deleted) {
    743             delete_cache_dir(path, dir);
    744         }
    745     }
    746 
    747     CACHE_NOISY(ALOGI("Trimming files..."));
    748     for (i=0; i<cache->numFiles; i++) {
    749         skip++;
    750         if (skip > 10) {
    751             if (data_disk_free() > free_size) {
    752                 return;
    753             }
    754             skip = 0;
    755         }
    756         cache_file_t* file = cache->files[i];
    757         strcpy(create_dir_path(path, file->dir), file->name);
    758         ALOGI("DEL (mod %d) %s\n", (int)file->modTime, path);
    759         if (unlink(path) < 0) {
    760             ALOGE("Couldn't unlink %s: %s\n", path, strerror(errno));
    761         }
    762         file->dir->childCount--;
    763         if (file->dir->childCount <= 0) {
    764             delete_cache_dir(path, file->dir);
    765         }
    766     }
    767 }
    768 
    769 void finish_cache_collection(cache_t* cache)
    770 {
    771     size_t i;
    772 
    773     CACHE_NOISY(ALOGI("clear_cache_files: %d dirs, %d files\n", cache->numDirs, cache->numFiles));
    774     CACHE_NOISY(
    775         for (i=0; i<cache->numDirs; i++) {
    776             cache_dir_t* dir = cache->dirs[i];
    777             ALOGI("dir #%d: %p %s parent=%p\n", i, dir, dir->name, dir->parent);
    778         })
    779     CACHE_NOISY(
    780         for (i=0; i<cache->numFiles; i++) {
    781             cache_file_t* file = cache->files[i];
    782             ALOGI("file #%d: %p %s time=%d dir=%p\n", i, file, file->name,
    783                     (int)file->modTime, file->dir);
    784         })
    785     void* block = cache->memBlocks;
    786     while (block != NULL) {
    787         void* nextBlock = *(void**)block;
    788         CACHE_NOISY(ALOGI("Freeing cache mem block: %p", block));
    789         free(block);
    790         block = nextBlock;
    791     }
    792     free(cache);
    793 }
    794 
    795 /**
    796  * Checks whether a path points to a system app (.apk file). Returns 0
    797  * if it is a system app or -1 if it is not.
    798  */
    799 int validate_system_app_path(const char* path) {
    800     size_t i;
    801 
    802     for (i = 0; i < android_system_dirs.count; i++) {
    803         const size_t dir_len = android_system_dirs.dirs[i].len;
    804         if (!strncmp(path, android_system_dirs.dirs[i].path, dir_len)) {
    805             if (path[dir_len] == '.' || strchr(path + dir_len, '/') != NULL) {
    806                 ALOGE("invalid system apk path '%s' (trickery)\n", path);
    807                 return -1;
    808             }
    809             return 0;
    810         }
    811     }
    812 
    813     return -1;
    814 }
    815 
    816 /**
    817  * Get the contents of a environment variable that contains a path. Caller
    818  * owns the string that is inserted into the directory record. Returns
    819  * 0 on success and -1 on error.
    820  */
    821 int get_path_from_env(dir_rec_t* rec, const char* var) {
    822     const char* path = getenv(var);
    823     int ret = get_path_from_string(rec, path);
    824     if (ret < 0) {
    825         ALOGW("Problem finding value for environment variable %s\n", var);
    826     }
    827     return ret;
    828 }
    829 
    830 /**
    831  * Puts the string into the record as a directory. Appends '/' to the end
    832  * of all paths. Caller owns the string that is inserted into the directory
    833  * record. A null value will result in an error.
    834  *
    835  * Returns 0 on success and -1 on error.
    836  */
    837 int get_path_from_string(dir_rec_t* rec, const char* path) {
    838     if (path == NULL) {
    839         return -1;
    840     } else {
    841         const size_t path_len = strlen(path);
    842         if (path_len <= 0) {
    843             return -1;
    844         }
    845 
    846         // Make sure path is absolute.
    847         if (path[0] != '/') {
    848             return -1;
    849         }
    850 
    851         if (path[path_len - 1] == '/') {
    852             // Path ends with a forward slash. Make our own copy.
    853 
    854             rec->path = strdup(path);
    855             if (rec->path == NULL) {
    856                 return -1;
    857             }
    858 
    859             rec->len = path_len;
    860         } else {
    861             // Path does not end with a slash. Generate a new string.
    862             char *dst;
    863 
    864             // Add space for slash and terminating null.
    865             size_t dst_size = path_len + 2;
    866 
    867             rec->path = malloc(dst_size);
    868             if (rec->path == NULL) {
    869                 return -1;
    870             }
    871 
    872             dst = rec->path;
    873 
    874             if (append_and_increment(&dst, path, &dst_size) < 0
    875                     || append_and_increment(&dst, "/", &dst_size)) {
    876                 ALOGE("Error canonicalizing path");
    877                 return -1;
    878             }
    879 
    880             rec->len = dst - rec->path;
    881         }
    882     }
    883     return 0;
    884 }
    885 
    886 int copy_and_append(dir_rec_t* dst, const dir_rec_t* src, const char* suffix) {
    887     dst->len = src->len + strlen(suffix);
    888     const size_t dstSize = dst->len + 1;
    889     dst->path = (char*) malloc(dstSize);
    890 
    891     if (dst->path == NULL
    892             || snprintf(dst->path, dstSize, "%s%s", src->path, suffix)
    893                     != (ssize_t) dst->len) {
    894         ALOGE("Could not allocate memory to hold appended path; aborting\n");
    895         return -1;
    896     }
    897 
    898     return 0;
    899 }
    900 
    901 /**
    902  * Check whether path points to a valid path for an APK file. An ASEC
    903  * directory is allowed to have one level of subdirectory names. Returns -1
    904  * when an invalid path is encountered and 0 when a valid path is encountered.
    905  */
    906 int validate_apk_path(const char *path)
    907 {
    908     int allowsubdir = 0;
    909     char *subdir = NULL;
    910     size_t dir_len;
    911     size_t path_len;
    912 
    913     if (!strncmp(path, android_app_dir.path, android_app_dir.len)) {
    914         dir_len = android_app_dir.len;
    915     } else if (!strncmp(path, android_app_private_dir.path, android_app_private_dir.len)) {
    916         dir_len = android_app_private_dir.len;
    917     } else if (!strncmp(path, android_asec_dir.path, android_asec_dir.len)) {
    918         dir_len = android_asec_dir.len;
    919         allowsubdir = 1;
    920     } else {
    921         ALOGE("invalid apk path '%s' (bad prefix)\n", path);
    922         return -1;
    923     }
    924 
    925     path_len = strlen(path);
    926 
    927     /*
    928      * Only allow the path to have a subdirectory if it's been marked as being allowed.
    929      */
    930     if ((subdir = strchr(path + dir_len, '/')) != NULL) {
    931         ++subdir;
    932         if (!allowsubdir
    933                 || (path_len > (size_t) (subdir - path) && (strchr(subdir, '/') != NULL))) {
    934             ALOGE("invalid apk path '%s' (subdir?)\n", path);
    935             return -1;
    936         }
    937     }
    938 
    939     /*
    940      *  Directories can't have a period directly after the directory markers
    941      *  to prevent ".."
    942      */
    943     if (path[dir_len] == '.'
    944             || (subdir != NULL && ((*subdir == '.') || (strchr(subdir, '/') != NULL)))) {
    945         ALOGE("invalid apk path '%s' (trickery)\n", path);
    946         return -1;
    947     }
    948 
    949     return 0;
    950 }
    951 
    952 int append_and_increment(char** dst, const char* src, size_t* dst_size) {
    953     ssize_t ret = strlcpy(*dst, src, *dst_size);
    954     if (ret < 0 || (size_t) ret >= *dst_size) {
    955         return -1;
    956     }
    957     *dst += ret;
    958     *dst_size -= ret;
    959     return 0;
    960 }
    961 
    962 char *build_string2(char *s1, char *s2) {
    963     if (s1 == NULL || s2 == NULL) return NULL;
    964 
    965     int len_s1 = strlen(s1);
    966     int len_s2 = strlen(s2);
    967     int len = len_s1 + len_s2 + 1;
    968     char *result = malloc(len);
    969     if (result == NULL) return NULL;
    970 
    971     strcpy(result, s1);
    972     strcpy(result + len_s1, s2);
    973 
    974     return result;
    975 }
    976 
    977 char *build_string3(char *s1, char *s2, char *s3) {
    978     if (s1 == NULL || s2 == NULL || s3 == NULL) return NULL;
    979 
    980     int len_s1 = strlen(s1);
    981     int len_s2 = strlen(s2);
    982     int len_s3 = strlen(s3);
    983     int len = len_s1 + len_s2 + len_s3 + 1;
    984     char *result = malloc(len);
    985     if (result == NULL) return NULL;
    986 
    987     strcpy(result, s1);
    988     strcpy(result + len_s1, s2);
    989     strcpy(result + len_s1 + len_s2, s3);
    990 
    991     return result;
    992 }
    993 
    994 /* Ensure that /data/media directories are prepared for given user. */
    995 int ensure_media_user_dirs(userid_t userid) {
    996     char media_user_path[PATH_MAX];
    997     char path[PATH_MAX];
    998 
    999     // Ensure /data/media/<userid> exists
   1000     create_persona_media_path(media_user_path, userid);
   1001     if (fs_prepare_dir(media_user_path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
   1002         return -1;
   1003     }
   1004 
   1005     return 0;
   1006 }
   1007