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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 int create_pkg_path(char path[PKG_PATH_MAX],
     20                     const char *prefix,
     21                     const char *pkgname,
     22                     const char *postfix)
     23 {
     24     int len;
     25     const char *x;
     26 
     27     len = strlen(pkgname);
     28     if (len > PKG_NAME_MAX) {
     29         return -1;
     30     }
     31     if ((len + strlen(prefix) + strlen(postfix)) >= PKG_PATH_MAX) {
     32         return -1;
     33     }
     34 
     35     x = pkgname;
     36     int alpha = -1;
     37     while (*x) {
     38         if (isalnum(*x) || (*x == '_')) {
     39                 /* alphanumeric or underscore are fine */
     40         } else if (*x == '.') {
     41             if ((x == pkgname) || (x[1] == '.') || (x[1] == 0)) {
     42                     /* periods must not be first, last, or doubled */
     43                 LOGE("invalid package name '%s'\n", pkgname);
     44                 return -1;
     45             }
     46         } else if (*x == '-') {
     47             /* Suffix -X is fine to let versioning of packages.
     48                But whatever follows should be alphanumeric.*/
     49             alpha = 1;
     50         }else {
     51                 /* anything not A-Z, a-z, 0-9, _, or . is invalid */
     52             LOGE("invalid package name '%s'\n", pkgname);
     53             return -1;
     54         }
     55         x++;
     56     }
     57     if (alpha == 1) {
     58         // Skip current character
     59         x++;
     60         while (*x) {
     61             if (!isalnum(*x)) {
     62                 LOGE("invalid package name '%s' should include only numbers after -\n", pkgname);
     63                 return -1;
     64             }
     65             x++;
     66         }
     67     }
     68 
     69     sprintf(path, "%s%s%s", prefix, pkgname, postfix);
     70     return 0;
     71 }
     72 
     73 static int _delete_dir_contents(DIR *d, const char *ignore)
     74 {
     75     int result = 0;
     76     struct dirent *de;
     77     int dfd;
     78 
     79     dfd = dirfd(d);
     80 
     81     if (dfd < 0) return -1;
     82 
     83     while ((de = readdir(d))) {
     84         const char *name = de->d_name;
     85 
     86             /* skip the ignore name if provided */
     87         if (ignore && !strcmp(name, ignore)) continue;
     88 
     89         if (de->d_type == DT_DIR) {
     90             int r, subfd;
     91             DIR *subdir;
     92 
     93                 /* always skip "." and ".." */
     94             if (name[0] == '.') {
     95                 if (name[1] == 0) continue;
     96                 if ((name[1] == '.') && (name[2] == 0)) continue;
     97             }
     98 
     99             subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
    100             if (subfd < 0) {
    101                 result = -1;
    102                 continue;
    103             }
    104             subdir = fdopendir(subfd);
    105             if (subdir == NULL) {
    106                 close(subfd);
    107                 result = -1;
    108                 continue;
    109             }
    110             if (_delete_dir_contents(subdir, 0)) {
    111                 result = -1;
    112             }
    113             closedir(subdir);
    114             if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
    115                 result = -1;
    116             }
    117         } else {
    118             if (unlinkat(dfd, name, 0) < 0) {
    119                 result = -1;
    120             }
    121         }
    122     }
    123 
    124     return result;
    125 }
    126 
    127 int delete_dir_contents(const char *pathname,
    128                         int also_delete_dir,
    129                         const char *ignore)
    130 {
    131     int res = 0;
    132     DIR *d;
    133 
    134     d = opendir(pathname);
    135     if (d == NULL) {
    136         return -errno;
    137     }
    138     res = _delete_dir_contents(d, ignore);
    139     closedir(d);
    140     if (also_delete_dir) {
    141         if (rmdir(pathname)) {
    142             res = -1;
    143         }
    144     }
    145     return res;
    146 }
    147 
    148 int delete_dir_contents_fd(int dfd, const char *name)
    149 {
    150     int fd, res;
    151     DIR *d;
    152 
    153     fd = openat(dfd, name, O_RDONLY | O_DIRECTORY);
    154     if (fd < 0) {
    155         return -1;
    156     }
    157     d = fdopendir(fd);
    158     if (d == NULL) {
    159         close(fd);
    160         return -1;
    161     }
    162     res = _delete_dir_contents(d, 0);
    163     closedir(d);
    164     return res;
    165 }
    166