diff --git a/tests/native/utilities/firewall.cpp b/tests/native/utilities/firewall.cpp
new file mode 100644
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--- /dev/null
+++ b/tests/native/utilities/firewall.cpp
@@ -0,0 +1,118 @@
+/*
+ * 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.
+ *
+ */
+
+#include "firewall.h"
+
+#include <android-base/result.h>
+#include <gtest/gtest.h>
+
+Firewall::Firewall() {
+    std::lock_guard guard(mMutex);
+    auto result = mConfigurationMap.init(CONFIGURATION_MAP_PATH);
+    EXPECT_RESULT_OK(result) << "init mConfigurationMap failed";
+
+    result = mUidOwnerMap.init(UID_OWNER_MAP_PATH);
+    EXPECT_RESULT_OK(result) << "init mUidOwnerMap failed";
+}
+
+Firewall* Firewall::getInstance() {
+    static Firewall instance;
+    return &instance;
+}
+
+Result<void> Firewall::toggleStandbyMatch(bool enable) {
+    std::lock_guard guard(mMutex);
+    uint32_t key = UID_RULES_CONFIGURATION_KEY;
+    auto oldConfiguration = mConfigurationMap.readValue(key);
+    if (!oldConfiguration.ok()) {
+        return Errorf("Cannot read the old configuration: {}", oldConfiguration.error().message());
+    }
+
+    BpfConfig newConfiguration = enable ? (oldConfiguration.value() | STANDBY_MATCH)
+                                        : (oldConfiguration.value() & (~STANDBY_MATCH));
+    auto res = mConfigurationMap.writeValue(key, newConfiguration, BPF_EXIST);
+    if (!res.ok()) return Errorf("Failed to toggle STANDBY_MATCH: {}", res.error().message());
+
+    return {};
+}
+
+Result<void> Firewall::addRule(uint32_t uid, UidOwnerMatchType match, uint32_t iif) {
+    // iif should be non-zero if and only if match == MATCH_IIF
+    if (match == IIF_MATCH && iif == 0) {
+        return Errorf("Interface match {} must have nonzero interface index", match);
+    } else if (match != IIF_MATCH && iif != 0) {
+        return Errorf("Non-interface match {} must have zero interface index", match);
+    }
+
+    std::lock_guard guard(mMutex);
+    auto oldMatch = mUidOwnerMap.readValue(uid);
+    if (oldMatch.ok()) {
+        UidOwnerValue newMatch = {
+                .iif = iif ? iif : oldMatch.value().iif,
+                .rule = static_cast<uint8_t>(oldMatch.value().rule | match),
+        };
+        auto res = mUidOwnerMap.writeValue(uid, newMatch, BPF_ANY);
+        if (!res.ok()) return Errorf("Failed to update rule: {}", res.error().message());
+    } else {
+        UidOwnerValue newMatch = {
+                .iif = iif,
+                .rule = static_cast<uint8_t>(match),
+        };
+        auto res = mUidOwnerMap.writeValue(uid, newMatch, BPF_ANY);
+        if (!res.ok()) return Errorf("Failed to add rule: {}", res.error().message());
+    }
+    return {};
+}
+
+Result<void> Firewall::removeRule(uint32_t uid, UidOwnerMatchType match) {
+    std::lock_guard guard(mMutex);
+    auto oldMatch = mUidOwnerMap.readValue(uid);
+    if (!oldMatch.ok()) return Errorf("uid: %u does not exist in map", uid);
+
+    UidOwnerValue newMatch = {
+            .iif = (match == IIF_MATCH) ? 0 : oldMatch.value().iif,
+            .rule = static_cast<uint8_t>(oldMatch.value().rule & ~match),
+    };
+    if (newMatch.rule == 0) {
+        auto res = mUidOwnerMap.deleteValue(uid);
+        if (!res.ok()) return Errorf("Failed to remove rule: {}", res.error().message());
+    } else {
+        auto res = mUidOwnerMap.writeValue(uid, newMatch, BPF_ANY);
+        if (!res.ok()) return Errorf("Failed to update rule: {}", res.error().message());
+    }
+    return {};
+}
+
+Result<void> Firewall::addUidInterfaceRules(const std::string& ifName,
+                                            const std::vector<int32_t>& uids) {
+    unsigned int iif = if_nametoindex(ifName.c_str());
+    if (!iif) return Errorf("Failed to get interface index: {}", ifName);
+
+    for (auto uid : uids) {
+        auto res = addRule(uid, IIF_MATCH, iif);
+        if (!res.ok()) return res;
+    }
+    return {};
+}
+
+Result<void> Firewall::removeUidInterfaceRules(const std::vector<int32_t>& uids) {
+    for (auto uid : uids) {
+        auto res = removeRule(uid, IIF_MATCH);
+        if (!res.ok()) return res;
+    }
+    return {};
+}