RK3576 双以太网

Android 12 对比 14 在多以太网差异

Android 14 确实在框架层面更好地处理了多个以太网接口的并行工作，尤其是在 Automotive OS 的推动下，对多网卡的支持成为了核心需求。

项目	Android 12	Android 14
🌐 多以太网接口支持	⚠️ 初步支持，仅 eth0 稳定；eth1 需定制	✅ 原生支持多接口，eth0/eth1 并行
⚙️ 接口识别机制	仅支持 `config_ethernet_iface_regex`	✅ 支持 `config_ethernet_interfaces` 精确控制
🔌 接口注册机制	默认只注册第一个接口	✅ 每个接口都通过 `NetworkOffer` 注册
📶 NetworkAgent 支持	仅 eth0 被注册为 NetworkAgent	✅ eth0 和 eth1 均注册为独立 NetworkAgent
📊 网络能力判定	固定能力集合，优先级不可控	✅ 可配置能力（如 NOT_METERED）以调整优先级
📈 网络优先级控制	❌ 固定优先级顺序	✅ 可通过 `persist.net.preferred.transports.order` 配置
🔄 Failover 自动切换	❌ 无法自动切换	✅ 支持网络断线自动切换
🔐 路由稳定性与多网支持	❌ 多接口路由易冲突	✅ netd 添加低优先级 rule 避免路由丢失
🧠 常驻连接策略	❌ 无机制	✅ 支持 `ethernet_always_requested` 设置
🛠️ 设置可控性	仅可通过修改源码实现	✅ 可通过 adb settings 和 SystemProperties 控制
🚗 Automotive 多域网络支持	❌ 无现成支持	✅ 与 Automotive 框架集成，支持域分离（如 IVI/TCU）
💡 Overlay 灵活性	配置点少，需改 framework	✅ 支持多个 config_xxx，便于产品差异化

android 14 源码

rk3576_android_14/packages/modules/Connectivity/service-t/src/com/android/server/ethernet

.
├── EthernetCallback.java
├── EthernetConfigStore.java
├── EthernetNetworkAgent.java
├── EthernetNetworkFactory.java
├── EthernetServiceImpl.java
├── EthernetService.java
└── EthernetTracker.java

补丁实现原理

Kernel：eth1 接口由驱动层创建，如 USB 网卡或 MAC1 启用；
EthernetTracker：系统监测到 eth1 接口上线，触发注册流程；
EthernetNetworkFactory：通过 registerNetworkOffer() 注册 eth1 网络能力；
ConnectivityService：接受 NetworkAgent 注册，构建 NetworkAgentInfo 实例；
NetworkAgentInfo：表示 eth1 成为系统中的一个活跃网络；
NetworkRanker：系统根据你配置的优先级（如 Ethernet > WiFi）决定 eth1 是否为默认；
RouteController (netd)：添加路由规则，防止 eth1 的网关丢失或路由冲突。

eth0 与 eth1 并存时的系统路由选择流程图


flowchart TD
    A[eth0 接口上线] --> B[EthernetTracker 注册 eth0]
    C[eth1 接口上线] --> D[EthernetTracker 注册 eth1]

    B --> E[EthernetNetworkFactory 注册 eth0 NetworkOffer]
    D --> F[EthernetNetworkFactory 注册 eth1 NetworkOffer（降权）]

    E --> G[ConnectivityService 注册 eth0 NetworkAgent]
    F --> H[ConnectivityService 注册 eth1 NetworkAgent]

    G --> I[NetworkCapabilities: eth0\nNOT_METERED, INTERNET]
    H --> J[NetworkCapabilities: eth1\nMETERED, INTERNET]

    I --> K[NetworkRanker 获取优先级]
    J --> K

    K --> L{优先级比较}
    L -- eth0 优先 --> M[eth0 设置为默认网络]
    L -- eth1 优先 --> N[eth1 设置为默认网络]

    M --> O[netd 设置默认路由 via eth0]
    N --> P[netd 设置默认路由 via eth1]

    G --> Q[netd 添加 eth0 直连路由]
    H --> R[netd 添加 eth1 直连路由]

eth0 一般具有更高优先级，因为它带有 NOT_METERED，系统认为它是免费/主链路；
eth1 被补丁刻意降级（去掉 NOT_METERED），系统会优先选择 eth0 为默认；
即便如此，eth1 仍注册为 NetworkAgent，可用于 failover、或特定请求；
netd 会为两个接口都添加 addDirectlyConnectedRule，避免路由冲突或丢失。

EthernetNetworkFactory.java

在注册 NetworkOffer 时，如果接口名是 eth1，就降权处理, 让系统识别 eth1 是次要网络，不抢占默认路由；但又注册为可用网络

        private void registerNetworkOffer() {
            // If mNetworkOfferCallback is already set, it should be reused to update the existing
            // offer.
            if (mNetworkOfferCallback == null) {
                mNetworkOfferCallback = new EthernetNetworkOfferCallback();
            }

            //lixiaogang add start
            if(name != null && name.equals("eth1")) {
                //mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
                mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED);
                //mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN);
                Log.d(TAG, "hcq mCapabilities: " + mCapabilities);
            }
            //lixiaogang add end

            mNetworkProvider.registerNetworkOffer(getNetworkScore(),
                    new NetworkCapabilities(mCapabilities), cmd -> mHandler.post(cmd),
                    mNetworkOfferCallback);
        }

ConnectivityService.java

强制注册并激活以太网 eth1 的连接请求

    private void handleConfigureAlwaysOnNetworks() {
        handleAlwaysOnNetworkRequest(mDefaultMobileDataRequest,
                ConnectivitySettingsManager.MOBILE_DATA_ALWAYS_ON, true /* defaultValue */);
        //modify defaultValue to true by lixiaogang
        handleAlwaysOnNetworkRequest(mDefaultWifiRequest,
                ConnectivitySettingsManager.WIFI_ALWAYS_REQUESTED, true /* defaultValue */);
        final boolean vehicleAlwaysRequested = mResources.get().getBoolean(
                R.bool.config_vehicleInternalNetworkAlwaysRequested);
        handleAlwaysOnNetworkRequest(mDefaultVehicleRequest, vehicleAlwaysRequested);

        //lixiaogang add start
        handleAlwaysOnNetworkRequest(mDefaultEthernetRequest,
                ConnectivitySettingsManager.ETHERNET_ALWAYS_REQUESTED, true /* defaultValue */);

        handleAlwaysOnNetworkRequest(mDefaultEthernetRequest,
                ConnectivitySettingsManager.BLUETOOTH_ALWAYS_REQUESTED, true /* defaultValue */);
        //lixiaogang add end
    }

    // 意图：避免系统主动断开 eth 网络连接（尤其是 eth1）
    private void teardownUnneededNetwork(NetworkAgentInfo nai) {
        if (nai.numRequestNetworkRequests() != 0) {
            for (int i = 0; i < nai.numNetworkRequests(); i++) {
                NetworkRequest nr = nai.requestAt(i);
                // Ignore listening and track default requests.
                if (!nr.isRequest()) continue;
                loge("Dead network still had at least " + nr);
                break;
            }
        }
        // delete by lixiaogang start
        // nai.disconnect();
        // delete by lixiaogang end
    }

RouteController.cpp

注册一条低优先级 IP rule，用于查找主路由表中直连网关地址，避免多个接口存在时路由冲突。

constexpr int32_t RULE_PRIORITY_DIRECTLY_CONNECTED                = 9999;


int RouteController::Init(unsigned localNetId) {
    if (int ret = flushRules()) {
        return ret;
    }
    if (int ret = addLegacyRouteRules()) {
        return ret;
    }
    if (int ret = addLocalNetworkRules(localNetId)) {
        return ret;
    }
    //lixiaogang add start
    if (int ret = addDirectlyConnectedRule()) {
       return ret;
    }
    //lixiaogang add end
    if (int ret = addUnreachableRule()) {
        return ret;
    }
    // Don't complain if we can't add the dummy network, since not all devices support it.
    configureDummyNetwork();

    updateTableNamesFile();
    return 0;
}

编译验证

修改packages/modules/Connectivity/service-t/src/com/android/server/ethernet/下文件

rk3576_android_14$ mmm packages/modules/Connectivity/

rk3576_android_14$ adb push out/soong/.intermediates/packages/modules/Connectivity/Tethering/apex/com.android.tethering/android_common_cfi_com.android.tethering_image/com.android.tethering.apex /data/local/tmp/

rk3576_android_14$ adb shell pm install --apex /data/local/tmp/com.android.tethering.apex
Success. Reboot device to apply staged session

rk3576_android_14$ adb reboot

双以太网-内外网共存修改

packages/modules/Connectivity/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java

public class EthernetNetworkFactory {

        void onIpLayerStarted(@NonNull final LinkProperties linkProperties) {

            mLinkProperties = linkProperties;

            //lixiaogang add start
            if ("eth1".equals(name)) {
                addInterfaceToLocalNetwork("eth1", linkProperties);
            }
            //lixiaogang add end
        }

        /**
         * 添加为内网
         * Add interface to local network
         */
        void addInterfaceToLocalNetwork(String iface, LinkProperties linkProperties) {
            try {
                Log.i(TAG, "*****************addInterfaceToLocalNetwork: " + iface);
                if (mNetd == null) {
                    Log.e(TAG, "INetd service not available");
                    return;
                }
                mNetd.networkAddInterface(INetd.LOCAL_NET_ID, iface);
                NetdUtils.addRoutesToLocalNetwork(mNetd, iface, linkProperties.getRoutes());
            } catch (Exception e) {
                Log.e(TAG, "Failed to add iface " + iface + " to local network: " + e);
            }
        }

        private void registerNetworkOffer() {
            //lixiaogang add start
            if(name != null && name.equals("eth1")) {
                // 移除访问互联网的能力
                mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
                //mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED);
                //mCapabilities.removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN);
                Log.d(TAG, "**********eth1 mCapabilities: " + mCapabilities);
            }
            //lixiaogang add end

            mNetworkProvider.registerNetworkOffer(getNetworkScore(),
                    new NetworkCapabilities(mCapabilities), cmd -> mHandler.post(cmd),
                    mNetworkOfferCallback);
        }

}

android 14