Move functions useful for crypto test into their own file
More refactoring in advance of work on bug.
Bug: 36029169
Test: compiles.
Change-Id: Ic4cdd4761e4c2b11a3ddca5c3bbc4d5e42fac9d4
diff --git a/FileDeviceUtils.cpp b/FileDeviceUtils.cpp
new file mode 100644
index 0000000..bc9f4bd
--- /dev/null
+++ b/FileDeviceUtils.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2017 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 "FileDeviceUtils.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <linux/fs.h>
+#include <linux/fiemap.h>
+#include <mntent.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+
+namespace {
+
+std::unique_ptr<struct fiemap> alloc_fiemap(uint32_t extent_count);
+
+}
+
+namespace android {
+namespace vold {
+
+// Given a file path, look for the corresponding block device in /proc/mount
+std::string BlockDeviceForPath(const std::string &path)
+{
+ std::unique_ptr<FILE, int(*)(FILE*)> mnts(setmntent("/proc/mounts", "re"), endmntent);
+ if (!mnts) {
+ PLOG(ERROR) << "Unable to open /proc/mounts";
+ return "";
+ }
+ std::string result;
+ size_t best_length = 0;
+ struct mntent *mnt; // getmntent returns a thread local, so it's safe.
+ while ((mnt = getmntent(mnts.get())) != nullptr) {
+ auto l = strlen(mnt->mnt_dir);
+ if (l > best_length &&
+ path.size() > l &&
+ path[l] == '/' &&
+ path.compare(0, l, mnt->mnt_dir) == 0) {
+ result = mnt->mnt_fsname;
+ best_length = l;
+ }
+ }
+ if (result.empty()) {
+ LOG(ERROR) <<"Didn't find a mountpoint to match path " << path;
+ return "";
+ }
+ LOG(DEBUG) << "For path " << path << " block device is " << result;
+ return result;
+}
+
+std::unique_ptr<struct fiemap> PathFiemap(const std::string &path, uint32_t extent_count)
+{
+ android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(
+ path.c_str(), O_RDONLY | O_CLOEXEC, 0)));
+ if (fd == -1) {
+ if (errno == ENOENT) {
+ PLOG(DEBUG) << "Unable to open " << path;
+ } else {
+ PLOG(ERROR) << "Unable to open " << path;
+ }
+ return nullptr;
+ }
+ auto fiemap = alloc_fiemap(extent_count);
+ if (ioctl(fd.get(), FS_IOC_FIEMAP, fiemap.get()) != 0) {
+ PLOG(ERROR) << "Unable to FIEMAP " << path;
+ return nullptr;
+ }
+ auto mapped = fiemap->fm_mapped_extents;
+ if (mapped < 1 || mapped > extent_count) {
+ LOG(ERROR) << "Extent count not in bounds 1 <= " << mapped << " <= " << extent_count
+ << " in " << path;
+ return nullptr;
+ }
+ return fiemap;
+}
+
+} // namespace vold
+} // namespace android
+
+namespace {
+
+std::unique_ptr<struct fiemap> alloc_fiemap(uint32_t extent_count)
+{
+ size_t allocsize = offsetof(struct fiemap, fm_extents[extent_count]);
+ std::unique_ptr<struct fiemap> res(new (::operator new (allocsize)) struct fiemap);
+ memset(res.get(), 0, allocsize);
+ res->fm_start = 0;
+ res->fm_length = UINT64_MAX;
+ res->fm_flags = 0;
+ res->fm_extent_count = extent_count;
+ res->fm_mapped_extents = 0;
+ return res;
+}
+
+}