Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 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 | |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 17 | #define LOG_TAG "cutils" |
| 18 | |
Jeff Sharkey | 44d6342 | 2013-09-12 09:44:48 -0700 | [diff] [blame] | 19 | /* These defines are only needed because prebuilt headers are out of date */ |
| 20 | #define __USE_XOPEN2K8 1 |
| 21 | #define _ATFILE_SOURCE 1 |
| 22 | #define _GNU_SOURCE 1 |
| 23 | |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 24 | #include <cutils/fs.h> |
| 25 | #include <cutils/log.h> |
| 26 | |
| 27 | #include <sys/types.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <fcntl.h> |
| 30 | #include <unistd.h> |
| 31 | #include <errno.h> |
| 32 | #include <string.h> |
| 33 | #include <limits.h> |
Nick Kralevich | 69ce489 | 2012-10-15 15:51:33 -0700 | [diff] [blame] | 34 | #include <stdlib.h> |
Jeff Sharkey | 44d6342 | 2013-09-12 09:44:48 -0700 | [diff] [blame] | 35 | #include <dirent.h> |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 36 | |
| 37 | #define ALL_PERMS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) |
| 38 | #define BUF_SIZE 64 |
| 39 | |
Jeff Sharkey | cf94fe1 | 2016-01-12 12:42:32 -0700 | [diff] [blame] | 40 | static int fs_prepare_dir_impl(const char* path, mode_t mode, uid_t uid, gid_t gid, |
| 41 | int allow_fixup) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 42 | // Check if path needs to be created |
| 43 | struct stat sb; |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 44 | if (TEMP_FAILURE_RETRY(lstat(path, &sb)) == -1) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 45 | if (errno == ENOENT) { |
| 46 | goto create; |
| 47 | } else { |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 48 | ALOGE("Failed to lstat(%s): %s", path, strerror(errno)); |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 49 | return -1; |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | // Exists, verify status |
| 54 | if (!S_ISDIR(sb.st_mode)) { |
| 55 | ALOGE("Not a directory: %s", path); |
| 56 | return -1; |
| 57 | } |
Jeff Sharkey | 8146403 | 2016-01-14 11:53:42 -0700 | [diff] [blame] | 58 | int owner_match = ((sb.st_uid == uid) && (sb.st_gid == gid)); |
| 59 | int mode_match = ((sb.st_mode & ALL_PERMS) == mode); |
| 60 | if (owner_match && mode_match) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 61 | return 0; |
Jeff Sharkey | cf94fe1 | 2016-01-12 12:42:32 -0700 | [diff] [blame] | 62 | } else if (allow_fixup) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 63 | goto fixup; |
Jeff Sharkey | cf94fe1 | 2016-01-12 12:42:32 -0700 | [diff] [blame] | 64 | } else { |
Jeff Sharkey | 8146403 | 2016-01-14 11:53:42 -0700 | [diff] [blame] | 65 | if (!owner_match) { |
| 66 | ALOGE("Expected path %s with owner %d:%d but found %d:%d", |
| 67 | path, uid, gid, sb.st_uid, sb.st_gid); |
| 68 | return -1; |
| 69 | } else { |
| 70 | ALOGW("Expected path %s with mode %o but found %o", |
| 71 | path, mode, (sb.st_mode & ALL_PERMS)); |
| 72 | return 0; |
| 73 | } |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 74 | } |
| 75 | |
| 76 | create: |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 77 | if (TEMP_FAILURE_RETRY(mkdir(path, mode)) == -1) { |
Jeff Sharkey | 489609b | 2012-09-25 11:10:16 -0700 | [diff] [blame] | 78 | if (errno != EEXIST) { |
| 79 | ALOGE("Failed to mkdir(%s): %s", path, strerror(errno)); |
| 80 | return -1; |
| 81 | } |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | fixup: |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 85 | if (TEMP_FAILURE_RETRY(chmod(path, mode)) == -1) { |
| 86 | ALOGE("Failed to chmod(%s, %d): %s", path, mode, strerror(errno)); |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 87 | return -1; |
| 88 | } |
Jeff Sharkey | ddb1733 | 2012-09-13 14:47:23 -0700 | [diff] [blame] | 89 | if (TEMP_FAILURE_RETRY(chown(path, uid, gid)) == -1) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 90 | ALOGE("Failed to chown(%s, %d, %d): %s", path, uid, gid, strerror(errno)); |
| 91 | return -1; |
| 92 | } |
| 93 | |
| 94 | return 0; |
| 95 | } |
| 96 | |
Jeff Sharkey | cf94fe1 | 2016-01-12 12:42:32 -0700 | [diff] [blame] | 97 | int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid) { |
| 98 | return fs_prepare_dir_impl(path, mode, uid, gid, 1); |
| 99 | } |
| 100 | |
| 101 | int fs_prepare_dir_strict(const char* path, mode_t mode, uid_t uid, gid_t gid) { |
| 102 | return fs_prepare_dir_impl(path, mode, uid, gid, 0); |
| 103 | } |
| 104 | |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 105 | int fs_read_atomic_int(const char* path, int* out_value) { |
Jeff Sharkey | 6de7026 | 2012-09-13 15:11:42 -0700 | [diff] [blame] | 106 | int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY)); |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 107 | if (fd == -1) { |
| 108 | ALOGE("Failed to read %s: %s", path, strerror(errno)); |
| 109 | return -1; |
| 110 | } |
| 111 | |
| 112 | char buf[BUF_SIZE]; |
Jeff Sharkey | 6de7026 | 2012-09-13 15:11:42 -0700 | [diff] [blame] | 113 | if (TEMP_FAILURE_RETRY(read(fd, buf, BUF_SIZE)) == -1) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 114 | ALOGE("Failed to read %s: %s", path, strerror(errno)); |
| 115 | goto fail; |
| 116 | } |
| 117 | if (sscanf(buf, "%d", out_value) != 1) { |
| 118 | ALOGE("Failed to parse %s: %s", path, strerror(errno)); |
| 119 | goto fail; |
| 120 | } |
| 121 | close(fd); |
| 122 | return 0; |
| 123 | |
| 124 | fail: |
| 125 | close(fd); |
| 126 | *out_value = -1; |
| 127 | return -1; |
| 128 | } |
| 129 | |
| 130 | int fs_write_atomic_int(const char* path, int value) { |
| 131 | char temp[PATH_MAX]; |
| 132 | if (snprintf(temp, PATH_MAX, "%s.XXXXXX", path) >= PATH_MAX) { |
| 133 | ALOGE("Path too long"); |
| 134 | return -1; |
| 135 | } |
| 136 | |
Jeff Sharkey | 6de7026 | 2012-09-13 15:11:42 -0700 | [diff] [blame] | 137 | int fd = TEMP_FAILURE_RETRY(mkstemp(temp)); |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 138 | if (fd == -1) { |
| 139 | ALOGE("Failed to open %s: %s", temp, strerror(errno)); |
| 140 | return -1; |
| 141 | } |
| 142 | |
| 143 | char buf[BUF_SIZE]; |
| 144 | int len = snprintf(buf, BUF_SIZE, "%d", value) + 1; |
| 145 | if (len > BUF_SIZE) { |
| 146 | ALOGE("Value %d too large: %s", value, strerror(errno)); |
| 147 | goto fail; |
| 148 | } |
Jeff Sharkey | 6de7026 | 2012-09-13 15:11:42 -0700 | [diff] [blame] | 149 | if (TEMP_FAILURE_RETRY(write(fd, buf, len)) < len) { |
Jeff Sharkey | 9685194 | 2012-08-27 15:03:37 -0700 | [diff] [blame] | 150 | ALOGE("Failed to write %s: %s", temp, strerror(errno)); |
| 151 | goto fail; |
| 152 | } |
| 153 | if (close(fd) == -1) { |
| 154 | ALOGE("Failed to close %s: %s", temp, strerror(errno)); |
| 155 | goto fail_closed; |
| 156 | } |
| 157 | |
| 158 | if (rename(temp, path) == -1) { |
| 159 | ALOGE("Failed to rename %s to %s: %s", temp, path, strerror(errno)); |
| 160 | goto fail_closed; |
| 161 | } |
| 162 | |
| 163 | return 0; |
| 164 | |
| 165 | fail: |
| 166 | close(fd); |
| 167 | fail_closed: |
| 168 | unlink(temp); |
| 169 | return -1; |
| 170 | } |
Jeff Sharkey | 44d6342 | 2013-09-12 09:44:48 -0700 | [diff] [blame] | 171 | |
Jeff Sharkey | 0ee7d8c | 2013-09-20 17:58:54 -0700 | [diff] [blame] | 172 | #ifndef __APPLE__ |
| 173 | |
Jeff Sharkey | 44d6342 | 2013-09-12 09:44:48 -0700 | [diff] [blame] | 174 | int fs_mkdirs(const char* path, mode_t mode) { |
| 175 | int res = 0; |
| 176 | int fd = 0; |
| 177 | struct stat sb; |
| 178 | char* buf = strdup(path); |
| 179 | |
| 180 | if (*buf != '/') { |
| 181 | ALOGE("Relative paths are not allowed: %s", buf); |
| 182 | res = -EINVAL; |
| 183 | goto done; |
| 184 | } |
| 185 | |
| 186 | if ((fd = open("/", 0)) == -1) { |
| 187 | ALOGE("Failed to open(/): %s", strerror(errno)); |
| 188 | res = -errno; |
| 189 | goto done; |
| 190 | } |
| 191 | |
| 192 | char* segment = buf + 1; |
| 193 | char* p = segment; |
| 194 | while (*p != '\0') { |
| 195 | if (*p == '/') { |
| 196 | *p = '\0'; |
| 197 | |
| 198 | if (!strcmp(segment, "..") || !strcmp(segment, ".") || !strcmp(segment, "")) { |
| 199 | ALOGE("Invalid path: %s", buf); |
| 200 | res = -EINVAL; |
| 201 | goto done_close; |
| 202 | } |
| 203 | |
| 204 | if (fstatat(fd, segment, &sb, AT_SYMLINK_NOFOLLOW) != 0) { |
| 205 | if (errno == ENOENT) { |
| 206 | /* Nothing there yet; let's create it! */ |
| 207 | if (mkdirat(fd, segment, mode) != 0) { |
| 208 | if (errno == EEXIST) { |
| 209 | /* We raced with someone; ignore */ |
| 210 | } else { |
| 211 | ALOGE("Failed to mkdirat(%s): %s", buf, strerror(errno)); |
| 212 | res = -errno; |
| 213 | goto done_close; |
| 214 | } |
| 215 | } |
| 216 | } else { |
| 217 | ALOGE("Failed to fstatat(%s): %s", buf, strerror(errno)); |
| 218 | res = -errno; |
| 219 | goto done_close; |
| 220 | } |
| 221 | } else { |
| 222 | if (S_ISLNK(sb.st_mode)) { |
| 223 | ALOGE("Symbolic links are not allowed: %s", buf); |
| 224 | res = -ELOOP; |
| 225 | goto done_close; |
| 226 | } |
| 227 | if (!S_ISDIR(sb.st_mode)) { |
| 228 | ALOGE("Existing segment not a directory: %s", buf); |
| 229 | res = -ENOTDIR; |
| 230 | goto done_close; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | /* Yay, segment is ready for us to step into */ |
| 235 | int next_fd; |
Nick Kralevich | 30a86eb | 2014-06-16 15:32:49 -0700 | [diff] [blame] | 236 | if ((next_fd = openat(fd, segment, O_NOFOLLOW | O_CLOEXEC)) == -1) { |
Jeff Sharkey | 44d6342 | 2013-09-12 09:44:48 -0700 | [diff] [blame] | 237 | ALOGE("Failed to openat(%s): %s", buf, strerror(errno)); |
| 238 | res = -errno; |
| 239 | goto done_close; |
| 240 | } |
| 241 | |
| 242 | close(fd); |
| 243 | fd = next_fd; |
| 244 | |
| 245 | *p = '/'; |
| 246 | segment = p + 1; |
| 247 | } |
| 248 | p++; |
| 249 | } |
| 250 | |
| 251 | done_close: |
| 252 | close(fd); |
| 253 | done: |
| 254 | free(buf); |
| 255 | return res; |
| 256 | } |
Jeff Sharkey | 0ee7d8c | 2013-09-20 17:58:54 -0700 | [diff] [blame] | 257 | |
| 258 | #endif |