[NETD-BPF#15] Move BPF map definition and utils to frameworks/libs/net/

1. Move BPF map definition and utilities to a common place that easy to
be referenced from both mainline module and platform code.

2. Create cc_library_headers bpf_map_utils which includes BPF map
definition and utils.

Bug: 202086915
Test: m; flash; boot
Test: cd system/netd/ && atest
Test: cd packages/modules/Connectivity && atest
Test: m gpuservice_unittest libtimeinstate_test bpf_module_test
      CtsAppOpsTestCases libbpf_load_test VtsBootconfigTest
      vts_test_binary_bpf_module bpf_benchmark libbpf_load_test
      libbpf_android_test
Change-Id: I4d54b0d69029f593b8da3099d7ae16279692dabd
diff --git a/staticlibs/native/bpf_map_utils/BpfMapTest.cpp b/staticlibs/native/bpf_map_utils/BpfMapTest.cpp
new file mode 100644
index 0000000..d0737b0
--- /dev/null
+++ b/staticlibs/native/bpf_map_utils/BpfMapTest.cpp
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2018 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 <fstream>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <gtest/gtest.h>
+
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
+#include "bpf/BpfMap.h"
+#include "bpf/BpfUtils.h"
+
+using ::testing::Test;
+
+namespace android {
+namespace bpf {
+
+using base::Result;
+using base::unique_fd;
+
+constexpr uint32_t TEST_MAP_SIZE = 10;
+constexpr uint32_t TEST_KEY1 = 1;
+constexpr uint32_t TEST_VALUE1 = 10;
+constexpr const char PINNED_MAP_PATH[] = "/sys/fs/bpf/testMap";
+
+class BpfMapTest : public testing::Test {
+  protected:
+    BpfMapTest() {}
+
+    void SetUp() {
+        EXPECT_EQ(0, setrlimitForTest());
+        if (!access(PINNED_MAP_PATH, R_OK)) {
+            EXPECT_EQ(0, remove(PINNED_MAP_PATH));
+        }
+    }
+
+    void TearDown() {
+        if (!access(PINNED_MAP_PATH, R_OK)) {
+            EXPECT_EQ(0, remove(PINNED_MAP_PATH));
+        }
+    }
+
+    void checkMapInvalid(BpfMap<uint32_t, uint32_t>& map) {
+        EXPECT_FALSE(map.isValid());
+        EXPECT_EQ(-1, map.getMap().get());
+    }
+
+    void checkMapValid(BpfMap<uint32_t, uint32_t>& map) {
+        EXPECT_LE(0, map.getMap().get());
+        EXPECT_TRUE(map.isValid());
+    }
+
+    void writeToMapAndCheck(BpfMap<uint32_t, uint32_t>& map, uint32_t key, uint32_t value) {
+        ASSERT_RESULT_OK(map.writeValue(key, value, BPF_ANY));
+        uint32_t value_read;
+        ASSERT_EQ(0, findMapEntry(map.getMap(), &key, &value_read));
+        checkValueAndStatus(value, value_read);
+    }
+
+    void checkValueAndStatus(uint32_t refValue, Result<uint32_t> value) {
+        ASSERT_RESULT_OK(value);
+        ASSERT_EQ(refValue, value.value());
+    }
+
+    void populateMap(uint32_t total, BpfMap<uint32_t, uint32_t>& map) {
+        for (uint32_t key = 0; key < total; key++) {
+            uint32_t value = key * 10;
+            EXPECT_RESULT_OK(map.writeValue(key, value, BPF_ANY));
+        }
+    }
+
+    void expectMapEmpty(BpfMap<uint32_t, uint32_t>& map) {
+        Result<bool> isEmpty = map.isEmpty();
+        ASSERT_RESULT_OK(isEmpty);
+        ASSERT_TRUE(isEmpty.value());
+    }
+};
+
+TEST_F(BpfMapTest, constructor) {
+    BpfMap<uint32_t, uint32_t> testMap1;
+    checkMapInvalid(testMap1);
+
+    BpfMap<uint32_t, uint32_t> testMap2(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    checkMapValid(testMap2);
+}
+
+TEST_F(BpfMapTest, basicHelpers) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    uint32_t key = TEST_KEY1;
+    uint32_t value_write = TEST_VALUE1;
+    writeToMapAndCheck(testMap, key, value_write);
+    Result<uint32_t> value_read = testMap.readValue(key);
+    checkValueAndStatus(value_write, value_read);
+    Result<uint32_t> key_read = testMap.getFirstKey();
+    checkValueAndStatus(key, key_read);
+    ASSERT_RESULT_OK(testMap.deleteValue(key));
+    ASSERT_GT(0, findMapEntry(testMap.getMap(), &key, &value_read));
+    ASSERT_EQ(ENOENT, errno);
+}
+
+TEST_F(BpfMapTest, reset) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    uint32_t key = TEST_KEY1;
+    uint32_t value_write = TEST_VALUE1;
+    writeToMapAndCheck(testMap, key, value_write);
+
+    testMap.reset(-1);
+    checkMapInvalid(testMap);
+    ASSERT_GT(0, findMapEntry(testMap.getMap(), &key, &value_write));
+    ASSERT_EQ(EBADF, errno);
+}
+
+TEST_F(BpfMapTest, moveConstructor) {
+    BpfMap<uint32_t, uint32_t> testMap1(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    BpfMap<uint32_t, uint32_t> testMap2;
+    testMap2 = std::move(testMap1);
+    uint32_t key = TEST_KEY1;
+    checkMapInvalid(testMap1);
+    uint32_t value = TEST_VALUE1;
+    writeToMapAndCheck(testMap2, key, value);
+}
+
+TEST_F(BpfMapTest, SetUpMap) {
+    EXPECT_NE(0, access(PINNED_MAP_PATH, R_OK));
+    BpfMap<uint32_t, uint32_t> testMap1(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    ASSERT_EQ(0, bpfFdPin(testMap1.getMap(), PINNED_MAP_PATH));
+    EXPECT_EQ(0, access(PINNED_MAP_PATH, R_OK));
+    checkMapValid(testMap1);
+    BpfMap<uint32_t, uint32_t> testMap2;
+    EXPECT_RESULT_OK(testMap2.init(PINNED_MAP_PATH));
+    checkMapValid(testMap2);
+    uint32_t key = TEST_KEY1;
+    uint32_t value = TEST_VALUE1;
+    writeToMapAndCheck(testMap1, key, value);
+    Result<uint32_t> value_read = testMap2.readValue(key);
+    checkValueAndStatus(value, value_read);
+}
+
+TEST_F(BpfMapTest, iterate) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    populateMap(TEST_MAP_SIZE, testMap);
+    int totalCount = 0;
+    int totalSum = 0;
+    const auto iterateWithDeletion = [&totalCount, &totalSum](const uint32_t& key,
+                                                              BpfMap<uint32_t, uint32_t>& map) {
+        EXPECT_GE((uint32_t)TEST_MAP_SIZE, key);
+        totalCount++;
+        totalSum += key;
+        return map.deleteValue(key);
+    };
+    EXPECT_RESULT_OK(testMap.iterate(iterateWithDeletion));
+    EXPECT_EQ((int)TEST_MAP_SIZE, totalCount);
+    EXPECT_EQ(((1 + TEST_MAP_SIZE - 1) * (TEST_MAP_SIZE - 1)) / 2, (uint32_t)totalSum);
+    expectMapEmpty(testMap);
+}
+
+TEST_F(BpfMapTest, iterateWithValue) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    populateMap(TEST_MAP_SIZE, testMap);
+    int totalCount = 0;
+    int totalSum = 0;
+    const auto iterateWithDeletion = [&totalCount, &totalSum](const uint32_t& key,
+                                                              const uint32_t& value,
+                                                              BpfMap<uint32_t, uint32_t>& map) {
+        EXPECT_GE((uint32_t)TEST_MAP_SIZE, key);
+        EXPECT_EQ(value, key * 10);
+        totalCount++;
+        totalSum += value;
+        return map.deleteValue(key);
+    };
+    EXPECT_RESULT_OK(testMap.iterateWithValue(iterateWithDeletion));
+    EXPECT_EQ((int)TEST_MAP_SIZE, totalCount);
+    EXPECT_EQ(((1 + TEST_MAP_SIZE - 1) * (TEST_MAP_SIZE - 1)) * 5, (uint32_t)totalSum);
+    expectMapEmpty(testMap);
+}
+
+TEST_F(BpfMapTest, mapIsEmpty) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    expectMapEmpty(testMap);
+    uint32_t key = TEST_KEY1;
+    uint32_t value_write = TEST_VALUE1;
+    writeToMapAndCheck(testMap, key, value_write);
+    Result<bool> isEmpty = testMap.isEmpty();
+    ASSERT_RESULT_OK(isEmpty);
+    ASSERT_FALSE(isEmpty.value());
+    ASSERT_RESULT_OK(testMap.deleteValue(key));
+    ASSERT_GT(0, findMapEntry(testMap.getMap(), &key, &value_write));
+    ASSERT_EQ(ENOENT, errno);
+    expectMapEmpty(testMap);
+    int entriesSeen = 0;
+    EXPECT_RESULT_OK(testMap.iterate(
+            [&entriesSeen](const unsigned int&,
+                           const BpfMap<unsigned int, unsigned int>&) -> Result<void> {
+                entriesSeen++;
+                return {};
+            }));
+    EXPECT_EQ(0, entriesSeen);
+    EXPECT_RESULT_OK(testMap.iterateWithValue(
+            [&entriesSeen](const unsigned int&, const unsigned int&,
+                           const BpfMap<unsigned int, unsigned int>&) -> Result<void> {
+                entriesSeen++;
+                return {};
+            }));
+    EXPECT_EQ(0, entriesSeen);
+}
+
+TEST_F(BpfMapTest, mapClear) {
+    BpfMap<uint32_t, uint32_t> testMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, BPF_F_NO_PREALLOC);
+    populateMap(TEST_MAP_SIZE, testMap);
+    Result<bool> isEmpty = testMap.isEmpty();
+    ASSERT_RESULT_OK(isEmpty);
+    ASSERT_FALSE(*isEmpty);
+    ASSERT_RESULT_OK(testMap.clear());
+    expectMapEmpty(testMap);
+}
+
+}  // namespace bpf
+}  // namespace android