fastboot: Introduce network-connected devices storage
Bug: 267507577
Bug: 267505625
Test: tested file lock api works on linux/windows
Test: tested storage api works on linux/windows
Change-Id: I33dda819370900310ae7fc63cbf6b00ba22ad4e8
Signed-off-by: Dmitrii Merkurev <dimorinny@google.com>
diff --git a/fastboot/filesystem.cpp b/fastboot/filesystem.cpp
new file mode 100644
index 0000000..a58ba00
--- /dev/null
+++ b/fastboot/filesystem.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#ifdef _WIN32
+#include <android-base/utf8.h>
+#include <direct.h>
+#include <shlobj.h>
+#else
+#include <pwd.h>
+#endif
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include "filesystem.h"
+
+namespace {
+
+int LockFile(int fd) {
+#ifdef _WIN32
+ HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
+ OVERLAPPED overlapped = {};
+ const BOOL locked = LockFileEx(handle, LOCKFILE_EXCLUSIVE_LOCK, 0,
+ MAXDWORD, MAXDWORD, &overlapped);
+ return locked ? 0 : -1;
+#else
+ return flock(fd, LOCK_EX);
+#endif
+}
+
+}
+
+// inspired by adb implementation:
+// cs.android.com/android/platform/superproject/+/master:packages/modules/adb/adb_utils.cpp;l=275
+std::string GetHomeDirPath() {
+#ifdef _WIN32
+ WCHAR path[MAX_PATH];
+ const HRESULT hr = SHGetFolderPathW(NULL, CSIDL_PROFILE, NULL, 0, path);
+ if (FAILED(hr)) {
+ return {};
+ }
+ std::string home_str;
+ if (!android::base::WideToUTF8(path, &home_str)) {
+ return {};
+ }
+ return home_str;
+#else
+ if (const char* const home = getenv("HOME")) {
+ return home;
+ }
+
+ struct passwd pwent;
+ struct passwd* result;
+ int pwent_max = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (pwent_max == -1) {
+ pwent_max = 16384;
+ }
+ std::vector<char> buf(pwent_max);
+ int rc = getpwuid_r(getuid(), &pwent, buf.data(), buf.size(), &result);
+ if (rc == 0 && result) {
+ return result->pw_dir;
+ }
+#endif
+
+ return {};
+}
+
+bool FileExists(const std::string& path) {
+ return access(path.c_str(), F_OK) == 0;
+}
+
+bool EnsureDirectoryExists(const std::string& directory_path) {
+ const int result =
+#ifdef _WIN32
+ _mkdir(directory_path.c_str());
+#else
+ mkdir(directory_path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
+#endif
+
+ return result == 0 || errno == EEXIST;
+}
+
+FileLock::FileLock(const std::string& path) : fd_(open(path.c_str(), O_CREAT | O_WRONLY, 0644)) {
+ if (LockFile(fd_.get()) != 0) {
+ LOG(FATAL) << "Failed to acquire a lock on " << path;
+ }
+}
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