Android rom开发：固定设置wifi热点的ip、ssid及密码

Android9.0起，开启wifi热点的逻辑进行了调整，ip ssid 密码均为随机生成，为便于通过wifi热点进行无线通信传输，特将固定设置wifi热点的ip、ssid及密码的方法总结如下：

modified:   frameworks/base/services/core/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachine.java

private boolean configureIPv4(boolean enabled) {
    if (VDBG) Log.d(TAG, "configureIPv4(" + enabled + ")");

    // TODO: Replace this hard-coded information with dynamically selected
    // config passed down to us by a higher layer IP-coordinating element.
    String ipAsString = null;
    int prefixLen = 0;
    if (mInterfaceType == ConnectivityManager.TETHERING_USB) {
        ipAsString = USB_NEAR_IFACE_ADDR;
        prefixLen = USB_PREFIX_LENGTH;
    } else if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
        ipAsString = getRandomWifiIPv4Address();
        //ip固定设置为192.168.43.1
        ipAsString = "192.168.43.1";
        prefixLen = WIFI_HOST_IFACE_PREFIX_LENGTH;
    } else {
        // Nothing to do, BT does this elsewhere.
        return true;
    }

    final LinkAddress linkAddr;
    try {
        final InterfaceConfiguration ifcg = mNMService.getInterfaceConfig(mIfaceName);
        if (ifcg == null) {
            mLog.e("Received null interface config");
            return false;
        }

        InetAddress addr = NetworkUtils.numericToInetAddress(ipAsString);
        linkAddr = new LinkAddress(addr, prefixLen);
        ifcg.setLinkAddress(linkAddr);
        if (mInterfaceType == ConnectivityManager.TETHERING_WIFI) {
            // The WiFi stack has ownership of the interface up/down state.
            // It is unclear whether the Bluetooth or USB stacks will manage their own
            // state.
            ifcg.ignoreInterfaceUpDownStatus();
        } else {
            if (enabled) {
                ifcg.setInterfaceUp();
            } else {
                ifcg.setInterfaceDown();
            }
        }
        ifcg.clearFlag("running");
        mNMService.setInterfaceConfig(mIfaceName, ifcg);
    } catch (Exception e) {
        mLog.e("Error configuring interface " + e);
        return false;
    }

    // Directly-connected route.
    final RouteInfo route = new RouteInfo(linkAddr);
    if (enabled) {
        mLinkProperties.addLinkAddress(linkAddr);
        mLinkProperties.addRoute(route);
    } else {
        mLinkProperties.removeLinkAddress(linkAddr);
        mLinkProperties.removeRoute(route);
    }
    return true;
}

modified:   frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiApConfigStore.java

private WifiConfiguration getDefaultApConfiguration() {
    WifiConfiguration config = new WifiConfiguration();
    config.apBand = WifiConfiguration.AP_BAND_2GHZ;
    config.SSID = mContext.getResources().getString(
            R.string.wifi_tether_configure_ssid_default) + "_" + getRandomIntForDefaultSsid();
    config.allowedKeyManagement.set(KeyMgmt.WPA2_PSK);
    String randomUUID = UUID.randomUUID().toString();
    //first 12 chars from xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
    config.preSharedKey = randomUUID.substring(0, 8) + randomUUID.substring(9, 13);
    //默认AP的ssid和密码固定写死
    config.SSID = "AndroidAP_test";
    config.preSharedKey = "123456test";
    return config;
}

以上代码验证平台为Android9.0。