[NETD-BPF#1] Move libnetdutils to frameworks/libs/net/...

libnetdutils is referenced by netd.c and TrafficController.cpp, which
are going to be mainlined. Therefore, move libnetdutils to a common
place where both mainline module and platform code (Netd) can refer to.

Bug: 202086915
Test: build; flash; cd system/netd; atest
Ignore-AOSP-First: the netd change(same topic) would not automerge from
aosp.
No-Typo-Check: Clean code move with no other changes.
BYPASS_INCLUSIVE_LANGUAGE_REASON=Clean code move with no other changes.
Change-Id: I645bfe35f6543149c9a9f894cd4158d27a481abe

staticlibs/netd/libnetdutils/FdTest.cpp

@@ -0,0 +1,147 @@
+/*
+ * 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 <cstdint>
+
+#include <gtest/gtest.h>
+
+#include "netdutils/MockSyscalls.h"
+#include "netdutils/Status.h"
+#include "netdutils/Syscalls.h"
+
+using testing::Mock;
+using testing::Return;
+using testing::StrictMock;
+
+namespace android {
+namespace netdutils {
+namespace {
+
+// Force implicit conversion from UniqueFd -> Fd
+inline Fd toFd(const UniqueFd& fd) {
+    return fd;
+}
+
+}  // namespace
+
+TEST(Fd, smoke) {
+    // Expect the following lines to compile
+    Fd fd1(1);
+    Fd fd2(fd1);
+    Fd fd3 = fd2;
+    const Fd fd4(8);
+    const Fd fd5(fd4);
+    const Fd fd6 = fd5;
+    EXPECT_TRUE(isWellFormed(fd3));
+    EXPECT_TRUE(isWellFormed(fd6));
+
+    // Corner case
+    Fd zero(0);
+    EXPECT_TRUE(isWellFormed(zero));
+
+    // Invalid file descriptors
+    Fd bad(-1);
+    Fd weird(-9);
+    EXPECT_FALSE(isWellFormed(bad));
+    EXPECT_FALSE(isWellFormed(weird));
+
+    // Default constructor
+    EXPECT_EQ(Fd(-1), Fd());
+    std::stringstream ss;
+    ss << fd3 << " " << fd6 << " " << bad << " " << weird;
+    EXPECT_EQ("Fd[1] Fd[8] Fd[-1] Fd[-9]", ss.str());
+}
+
+class UniqueFdTest : public testing::Test {
+  protected:
+    StrictMock<ScopedMockSyscalls> mSyscalls;
+};
+
+TEST_F(UniqueFdTest, operatorOstream) {
+    UniqueFd u(97);
+    EXPECT_CALL(mSyscalls, close(toFd(u))).WillOnce(Return(status::ok));
+    std::stringstream ss;
+    ss << u;
+    EXPECT_EQ("UniqueFd[Fd[97]]", ss.str());
+    u.reset();
+}
+
+TEST_F(UniqueFdTest, destructor) {
+    {
+        UniqueFd u(98);
+        EXPECT_CALL(mSyscalls, close(toFd(u))).WillOnce(Return(status::ok));
+    }
+    // Expectation above should be upon leaving nested scope
+    Mock::VerifyAndClearExpectations(&mSyscalls);
+}
+
+TEST_F(UniqueFdTest, reset) {
+    UniqueFd u(99);
+    EXPECT_CALL(mSyscalls, close(toFd(u))).WillOnce(Return(status::ok));
+    u.reset();
+
+    // Expectation above should be upon reset
+    Mock::VerifyAndClearExpectations(&mSyscalls);
+}
+
+TEST_F(UniqueFdTest, moveConstructor) {
+    constexpr Fd kFd(101);
+    UniqueFd u1(kFd);
+    {
+        UniqueFd u2(std::move(u1));
+        // NOLINTNEXTLINE bugprone-use-after-move
+        EXPECT_FALSE(isWellFormed(u1));
+        EXPECT_TRUE(isWellFormed(u2));
+        EXPECT_CALL(mSyscalls, close(kFd)).WillOnce(Return(status::ok));
+    }
+    // Expectation above should be upon leaving nested scope
+    Mock::VerifyAndClearExpectations(&mSyscalls);
+}
+
+TEST_F(UniqueFdTest, moveAssignment) {
+    constexpr Fd kFd(102);
+    UniqueFd u1(kFd);
+    {
+        UniqueFd u2 = std::move(u1);
+        // NOLINTNEXTLINE bugprone-use-after-move
+        EXPECT_FALSE(isWellFormed(u1));
+        EXPECT_TRUE(isWellFormed(u2));
+        UniqueFd u3;
+        u3 = std::move(u2);
+        // NOLINTNEXTLINE bugprone-use-after-move
+        EXPECT_FALSE(isWellFormed(u2));
+        EXPECT_TRUE(isWellFormed(u3));
+        EXPECT_CALL(mSyscalls, close(kFd)).WillOnce(Return(status::ok));
+    }
+    // Expectation above should be upon leaving nested scope
+    Mock::VerifyAndClearExpectations(&mSyscalls);
+}
+
+TEST_F(UniqueFdTest, constConstructor) {
+    constexpr Fd kFd(103);
+    const UniqueFd u(kFd);
+    EXPECT_CALL(mSyscalls, close(toFd(u))).WillOnce(Return(status::ok));
+}
+
+TEST_F(UniqueFdTest, closeFailure) {
+    constexpr Fd kFd(103);
+    UniqueFd u(kFd);
+    EXPECT_CALL(mSyscalls, close(toFd(u))).WillOnce(Return(statusFromErrno(EINTR, "test")));
+    EXPECT_DEBUG_DEATH(u.reset(), "");
+}
+
+}  // namespace netdutils
+}  // namespace android