Move BpfUtils -- add libtcutils
This CL is copying the "generic" parts of BpfUtils to
frameworks/libs/net/common. "Generic" meaning the parts that will be
used by both TcUtils in frameworks/libs/net/common and netd.
Bug: 202086915
Bug: 157552970
Test: atest TetheringTests
Change-Id: I9e780fc22e30d046f44953a8cac7687cb6c721c7
diff --git a/staticlibs/native/tcutils/scopeguard.h b/staticlibs/native/tcutils/scopeguard.h
new file mode 100644
index 0000000..76bbb93
--- /dev/null
+++ b/staticlibs/native/tcutils/scopeguard.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+// -----------------------------------------------------------------------------
+// TODO: figure out a way to use libbase_ndk. This is currently not working
+// because of missing apex availability. For now, we can use a copy of
+// ScopeGuard which is very lean compared to unique_fd. This code has been
+// copied verbatim from:
+// https://cs.android.com/android/platform/superproject/+/master:system/libbase/include/android-base/scopeguard.h
+
+#pragma once
+
+#include <utility> // for std::move, std::forward
+
+namespace android {
+namespace base {
+
+// ScopeGuard ensures that the specified functor is executed no matter how the
+// current scope exits.
+template <typename F> class ScopeGuard {
+public:
+ ScopeGuard(F &&f) : f_(std::forward<F>(f)), active_(true) {}
+
+ ScopeGuard(ScopeGuard &&that) noexcept
+ : f_(std::move(that.f_)), active_(that.active_) {
+ that.active_ = false;
+ }
+
+ template <typename Functor>
+ ScopeGuard(ScopeGuard<Functor> &&that)
+ : f_(std::move(that.f_)), active_(that.active_) {
+ that.active_ = false;
+ }
+
+ ~ScopeGuard() {
+ if (active_)
+ f_();
+ }
+
+ ScopeGuard() = delete;
+ ScopeGuard(const ScopeGuard &) = delete;
+ void operator=(const ScopeGuard &) = delete;
+ void operator=(ScopeGuard &&that) = delete;
+
+ void Disable() { active_ = false; }
+
+ bool active() const { return active_; }
+
+private:
+ template <typename Functor> friend class ScopeGuard;
+
+ F f_;
+ bool active_;
+};
+
+template <typename F> ScopeGuard<F> make_scope_guard(F &&f) {
+ return ScopeGuard<F>(std::forward<F>(f));
+}
+
+} // namespace base
+} // namespace android