Move libcutils source to C++.
Just the minimial changes to get this to actually build, because otherwise
we always bog down trying to rewrite everything (when the real answer
is usually "stop using libcutils, it's awful").
This doesn't move a handful of files: two are basically just BSD libc
source, a couple have outstanding code reviews, and one can be deleted
(but I'll do that in a separate change).
I'm also skipping the presubmit hooks because otherwise clang-format
wants to reformat everything. I'll follow up with that...
Bug: N/A
Test: builds
Change-Id: I06403f465b67c8e493bad466dd76b1151eed5993
diff --git a/libcutils/fs.cpp b/libcutils/fs.cpp
new file mode 100644
index 0000000..ef85acc
--- /dev/null
+++ b/libcutils/fs.cpp
@@ -0,0 +1,276 @@
+/*
+ * 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.
+ */
+
+#include <cutils/fs.h>
+
+#define LOG_TAG "cutils"
+
+/* These defines are only needed because prebuilt headers are out of date */
+#define __USE_XOPEN2K8 1
+#define _ATFILE_SOURCE 1
+#define _GNU_SOURCE 1
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <log/log.h>
+
+#define ALL_PERMS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
+#define BUF_SIZE 64
+
+static int fs_prepare_path_impl(const char* path, mode_t mode, uid_t uid, gid_t gid,
+ int allow_fixup, int prepare_as_dir) {
+ // TODO: fix the goto hell below.
+ int type_ok;
+ int owner_match;
+ int mode_match;
+
+ // Check if path needs to be created
+ struct stat sb;
+ int create_result = -1;
+ 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
+ type_ok = prepare_as_dir ? S_ISDIR(sb.st_mode) : S_ISREG(sb.st_mode);
+ if (!type_ok) {
+ ALOGE("Not a %s: %s", (prepare_as_dir ? "directory" : "regular file"), path);
+ return -1;
+ }
+
+ owner_match = ((sb.st_uid == uid) && (sb.st_gid == gid));
+ mode_match = ((sb.st_mode & ALL_PERMS) == mode);
+ if (owner_match && mode_match) {
+ return 0;
+ } else if (allow_fixup) {
+ goto fixup;
+ } else {
+ if (!owner_match) {
+ ALOGE("Expected path %s with owner %d:%d but found %d:%d",
+ path, uid, gid, sb.st_uid, sb.st_gid);
+ return -1;
+ } else {
+ ALOGW("Expected path %s with mode %o but found %o",
+ path, mode, (sb.st_mode & ALL_PERMS));
+ return 0;
+ }
+ }
+
+create:
+ create_result = prepare_as_dir
+ ? TEMP_FAILURE_RETRY(mkdir(path, mode))
+ : TEMP_FAILURE_RETRY(open(path, O_CREAT | O_CLOEXEC | O_NOFOLLOW | O_RDONLY, 0644));
+ if (create_result == -1) {
+ if (errno != EEXIST) {
+ ALOGE("Failed to %s(%s): %s",
+ (prepare_as_dir ? "mkdir" : "open"), path, strerror(errno));
+ return -1;
+ }
+ } else if (!prepare_as_dir) {
+ // For regular files we need to make sure we close the descriptor
+ if (close(create_result) == -1) {
+ ALOGW("Failed to close file after create %s: %s", path, strerror(errno));
+ }
+ }
+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_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid) {
+ return fs_prepare_path_impl(path, mode, uid, gid, /*allow_fixup*/ 1, /*prepare_as_dir*/ 1);
+}
+
+int fs_prepare_dir_strict(const char* path, mode_t mode, uid_t uid, gid_t gid) {
+ return fs_prepare_path_impl(path, mode, uid, gid, /*allow_fixup*/ 0, /*prepare_as_dir*/ 1);
+}
+
+int fs_prepare_file_strict(const char* path, mode_t mode, uid_t uid, gid_t gid) {
+ return fs_prepare_path_impl(path, mode, uid, gid, /*allow_fixup*/ 0, /*prepare_as_dir*/ 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;
+}
+
+#ifndef __APPLE__
+
+int fs_mkdirs(const char* path, mode_t mode) {
+ if (*path != '/') {
+ ALOGE("Relative paths are not allowed: %s", path);
+ return -EINVAL;
+ }
+
+ int fd = open("/", 0);
+ if (fd == -1) {
+ ALOGE("Failed to open(/): %s", strerror(errno));
+ return -errno;
+ }
+
+ struct stat sb;
+ int res = 0;
+ char* buf = strdup(path);
+ char* segment = buf + 1;
+ char* p = segment;
+ while (*p != '\0') {
+ if (*p == '/') {
+ *p = '\0';
+
+ if (!strcmp(segment, "..") || !strcmp(segment, ".") || !strcmp(segment, "")) {
+ ALOGE("Invalid path: %s", buf);
+ res = -EINVAL;
+ goto done_close;
+ }
+
+ if (fstatat(fd, segment, &sb, AT_SYMLINK_NOFOLLOW) != 0) {
+ if (errno == ENOENT) {
+ /* Nothing there yet; let's create it! */
+ if (mkdirat(fd, segment, mode) != 0) {
+ if (errno == EEXIST) {
+ /* We raced with someone; ignore */
+ } else {
+ ALOGE("Failed to mkdirat(%s): %s", buf, strerror(errno));
+ res = -errno;
+ goto done_close;
+ }
+ }
+ } else {
+ ALOGE("Failed to fstatat(%s): %s", buf, strerror(errno));
+ res = -errno;
+ goto done_close;
+ }
+ } else {
+ if (S_ISLNK(sb.st_mode)) {
+ ALOGE("Symbolic links are not allowed: %s", buf);
+ res = -ELOOP;
+ goto done_close;
+ }
+ if (!S_ISDIR(sb.st_mode)) {
+ ALOGE("Existing segment not a directory: %s", buf);
+ res = -ENOTDIR;
+ goto done_close;
+ }
+ }
+
+ /* Yay, segment is ready for us to step into */
+ int next_fd;
+ if ((next_fd = openat(fd, segment, O_NOFOLLOW | O_CLOEXEC)) == -1) {
+ ALOGE("Failed to openat(%s): %s", buf, strerror(errno));
+ res = -errno;
+ goto done_close;
+ }
+
+ close(fd);
+ fd = next_fd;
+
+ *p = '/';
+ segment = p + 1;
+ }
+ p++;
+ }
+
+done_close:
+ close(fd);
+ free(buf);
+ return res;
+}
+
+#endif