源码环境：高通Android 13
这里特别说明，Android13中，ipconfig.txt配置文件目录有改变
以前：/data/misc/ethernet/ipconfig.txt
最新的有线网配置文件保存目录：
/data/misc/apexdata/com.android.tethering/misc/ethernet/ipconfig.txt
一、Android 版本影响
首先就是Android 11 与 12 的有线网络版本差距还是比较大的，源码目录也变了，之前目录frameworks/opt/net/ethernet/java/com/android/server/ethernet，现在改成了packages/modules/Connectivity/service-t/src/com/android/server/ethernet，所以如果之前只在11上面适配过，那么对于12来说，适配还是需要花费一点功夫，具体的差异在之后的部分会记录，但是12与13的有线网络差异就较小了，并且看起来，13的以太网接口以及逻辑比12来说更为完善。
二、配置以太网所需要的类
配置以太网所需要的java类大概有以下几个，其实这几个类从Android9开始就是以太网配置的主要java类了
（1）、frameworks/base/core/java/android/net/EthernetManager.java
EthernetManager.java此是上层管理以太网的类，我们常通过context.getSystemService(Context.ETHERNET_SERVICE)获得他的实例对象
（2）、packages/modules/Connectivity/framework/src/android/net/IpConfiguration.java
这个类主要就是用来配置IP状态的，包括动态和静态
(3)、packages/modules/Connectivity/framework/src/android/net/StaticIpConfiguration.java
这个类主要就是用来配置静态IP的，这个类之前也是在frameworks/base/core/java/android/net/路径下，12里面也移到了packages/modules/Connectivity/framework/src/android/net/下
三、有线以太网静态ip保存逻辑从源码逐步分析
1、packages/modules/Connectivity/framework-t/src/android/net/EthernetManager.java
public void setConfiguration(@NonNull String iface, @NonNull IpConfiguration config) {
try {
mService.setConfiguration(iface, config);//这里调用的是EthernetServiceImpl.java中的setConfiguration
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
}
}
2、packages/modules/Connectivity/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
/**
* Set Ethernet configuration
*/
@Override
public void setConfiguration(String iface, IpConfiguration config) {
throwIfEthernetNotStarted();
PermissionUtils.enforceNetworkStackPermission(mContext);
if (mTracker.isRestrictedInterface(iface)) {
PermissionUtils.enforceRestrictedNetworkPermission(mContext, TAG);
}
// TODO: this does not check proxy settings, gateways, etc.
// Fix this by making IpConfiguration a complete representation of static configuration.
mTracker.updateIpConfiguration(iface, new IpConfiguration(config));//这里更新保存
}
3、packages/modules/Connectivity/service-t/src/com/android/server/ethernet/EthernetTracker.java
EthernetTracker中主要做了以下两件事 ：
(1). 首先更新 ip config的，这个和静态ip相关；
(2). 根据iface，调用addInterface创建interface
void updateIpConfiguration(String iface, IpConfiguration ipConfiguration) {
if (DBG) {
Log.i(TAG, "updateIpConfiguration, iface: " + iface + ", cfg: " + ipConfiguration);
}
writeIpConfiguration(iface, ipConfiguration);
mHandler.post(() -> {
mFactory.updateInterface(iface, ipConfiguration, null, null);
broadcastInterfaceStateChange(iface);
});
}
private void writeIpConfiguration(@NonNull final String iface,
@NonNull final IpConfiguration ipConfig) {
mConfigStore.write(iface, ipConfig);//这里调用了EthernetConfigStore.java中的write
mIpConfigurations.put(iface, ipConfig);
}
4、packages/modules/Connectivity/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
private static final String CONFIG_FILE = "ipconfig.txt";
private static final String FILE_PATH = "/misc/ethernet/";
private static final String APEX_IP_CONFIG_FILE_PATH = ApexEnvironment.getApexEnvironment(
TETHERING_MODULE_NAME).getDeviceProtectedDataDir() + FILE_PATH;
public void write(String iface, IpConfiguration config) {
write(iface, config, APEX_IP_CONFIG_FILE_PATH + CONFIG_FILE);//注意：这里Android13调整了保存路径，全路径：/data/misc/apexdata/com.android.tethering/misc/ethernet/ipconfig.txt
//Android 10版本保存路径为：/data/misc/ethernet/ipconfig.txt
}
void write(String iface, IpConfiguration config, String filepath) {
boolean modified;
synchronized (mSync) {
if (config == null) {
modified = mIpConfigurations.remove(iface) != null;
} else {
IpConfiguration oldConfig = mIpConfigurations.put(iface, config);
modified = !config.equals(oldConfig);
}
if (modified) {
mStore.writeIpConfigurations(filepath, mIpConfigurations);//这里调用的是IpConfigStore.java
}
}
}
5、packages/modules/Connectivity/service-t/src/com/android/server/net/IpConfigStore.java
/**
* Write the IP configuration associated to the target networks to the destination path.
*/
public void writeIpConfigurations(String filePath,
ArrayMap<String, IpConfiguration> networks) {
mWriter.write(filePath, out -> {
out.writeInt(IPCONFIG_FILE_VERSION);
for (int i = 0; i < networks.size(); i++) {
writeConfig(out, networks.keyAt(i), networks.valueAt(i));
}
});
}
private static boolean writeConfig(DataOutputStream out, String configKey,
IpConfiguration config) throws IOException {
return writeConfig(out, configKey, config, IPCONFIG_FILE_VERSION);
}
//这里最终完成静态ip写到配置文件：/data/misc/apexdata/com.android.tethering/misc/ethernet/ipconfig.txt
public static boolean writeConfig(DataOutputStream out, String configKey,
IpConfiguration config, int version) throws IOException {
boolean written = false;
try {
switch (config.getIpAssignment()) {
case STATIC:
out.writeUTF(IP_ASSIGNMENT_KEY);
out.writeUTF(config.getIpAssignment().toString());
StaticIpConfiguration staticIpConfiguration = config.getStaticIpConfiguration();
if (staticIpConfiguration != null) {
if (staticIpConfiguration.getIpAddress() != null) {
LinkAddress ipAddress = staticIpConfiguration.getIpAddress();
out.writeUTF(LINK_ADDRESS_KEY);
out.writeUTF(ipAddress.getAddress().getHostAddress());
out.writeInt(ipAddress.getPrefixLength());
}
if (staticIpConfiguration.getGateway() != null) {
out.writeUTF(GATEWAY_KEY);
out.writeInt(0); // Default route.
out.writeInt(1); // Have a gateway.
out.writeUTF(staticIpConfiguration.getGateway().getHostAddress());
}
for (InetAddress inetAddr : staticIpConfiguration.getDnsServers()) {
out.writeUTF(DNS_KEY);
out.writeUTF(inetAddr.getHostAddress());
}
}
written = true;
break;
case DHCP:
out.writeUTF(IP_ASSIGNMENT_KEY);
out.writeUTF(config.getIpAssignment().toString());
written = true;
break;
case UNASSIGNED:
/* Ignore */
break;
default:
loge("Ignore invalid ip assignment while writing");
break;
}
switch (config.getProxySettings()) {
case STATIC:
ProxyInfo proxyProperties = config.getHttpProxy();
String exclusionList = ProxyUtils.exclusionListAsString(
proxyProperties.getExclusionList());
out.writeUTF(PROXY_SETTINGS_KEY);
out.writeUTF(config.getProxySettings().toString());
out.writeUTF(PROXY_HOST_KEY);
out.writeUTF(proxyProperties.getHost());
out.writeUTF(PROXY_PORT_KEY);
out.writeInt(proxyProperties.getPort());
if (exclusionList != null) {
out.writeUTF(EXCLUSION_LIST_KEY);
out.writeUTF(exclusionList);
}
written = true;
break;
case PAC:
ProxyInfo proxyPacProperties = config.getHttpProxy();
out.writeUTF(PROXY_SETTINGS_KEY);
out.writeUTF(config.getProxySettings().toString());
out.writeUTF(PROXY_PAC_FILE);
out.writeUTF(proxyPacProperties.getPacFileUrl().toString());
written = true;
break;
case NONE:
out.writeUTF(PROXY_SETTINGS_KEY);
out.writeUTF(config.getProxySettings().toString());
written = true;
break;
case UNASSIGNED:
/* Ignore */
break;
default:
loge("Ignore invalid proxy settings while writing");
break;
}
if (written) {
out.writeUTF(ID_KEY);
if (version < 3) {
out.writeInt(Integer.valueOf(configKey));
} else {
out.writeUTF(configKey);
}
}
} catch (NullPointerException e) {
loge("Failure in writing " + config + e);
}
out.writeUTF(EOS);
return written;
}
