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- /*
- * Copyright (C) 2012 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.
- */
- #define LOG_TAG "cutils"
- #include <cutils/fs.h>
- #include <cutils/log.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <unistd.h>
- #include <errno.h>
- #include <string.h>
- #include <limits.h>
- #define ALL_PERMS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
- #define BUF_SIZE 64
- int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid) {
- // Check if path needs to be created
- struct stat sb;
- if (TEMP_FAILURE_RETRY(lstat(path, &sb)) == -1) {
- if (errno == ENOENT) {
- goto create;
- } else {
- ALOGE("Failed to lstat(%s): %s", path, strerror(errno));
- return -1;
- }
- }
- // Exists, verify status
- if (!S_ISDIR(sb.st_mode)) {
- ALOGE("Not a directory: %s", path);
- return -1;
- }
- if (((sb.st_mode & ALL_PERMS) == mode) && (sb.st_uid == uid) && (sb.st_gid == gid)) {
- return 0;
- } else {
- goto fixup;
- }
- create:
- if (TEMP_FAILURE_RETRY(mkdir(path, mode)) == -1) {
- if (errno != EEXIST) {
- ALOGE("Failed to mkdir(%s): %s", path, strerror(errno));
- return -1;
- }
- }
- fixup:
- if (TEMP_FAILURE_RETRY(chmod(path, mode)) == -1) {
- ALOGE("Failed to chmod(%s, %d): %s", path, mode, strerror(errno));
- return -1;
- }
- if (TEMP_FAILURE_RETRY(chown(path, uid, gid)) == -1) {
- ALOGE("Failed to chown(%s, %d, %d): %s", path, uid, gid, strerror(errno));
- return -1;
- }
- return 0;
- }
- int fs_read_atomic_int(const char* path, int* out_value) {
- int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY));
- if (fd == -1) {
- ALOGE("Failed to read %s: %s", path, strerror(errno));
- return -1;
- }
- char buf[BUF_SIZE];
- if (TEMP_FAILURE_RETRY(read(fd, buf, BUF_SIZE)) == -1) {
- ALOGE("Failed to read %s: %s", path, strerror(errno));
- goto fail;
- }
- if (sscanf(buf, "%d", out_value) != 1) {
- ALOGE("Failed to parse %s: %s", path, strerror(errno));
- goto fail;
- }
- close(fd);
- return 0;
- fail:
- close(fd);
- *out_value = -1;
- return -1;
- }
- int fs_write_atomic_int(const char* path, int value) {
- char temp[PATH_MAX];
- if (snprintf(temp, PATH_MAX, "%s.XXXXXX", path) >= PATH_MAX) {
- ALOGE("Path too long");
- return -1;
- }
- int fd = TEMP_FAILURE_RETRY(mkstemp(temp));
- if (fd == -1) {
- ALOGE("Failed to open %s: %s", temp, strerror(errno));
- return -1;
- }
- char buf[BUF_SIZE];
- int len = snprintf(buf, BUF_SIZE, "%d", value) + 1;
- if (len > BUF_SIZE) {
- ALOGE("Value %d too large: %s", value, strerror(errno));
- goto fail;
- }
- if (TEMP_FAILURE_RETRY(write(fd, buf, len)) < len) {
- ALOGE("Failed to write %s: %s", temp, strerror(errno));
- goto fail;
- }
- if (close(fd) == -1) {
- ALOGE("Failed to close %s: %s", temp, strerror(errno));
- goto fail_closed;
- }
- if (rename(temp, path) == -1) {
- ALOGE("Failed to rename %s to %s: %s", temp, path, strerror(errno));
- goto fail_closed;
- }
- return 0;
- fail:
- close(fd);
- fail_closed:
- unlink(temp);
- return -1;
- }
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