一、Android系统代码中实现设备名分配
1. \frameworks\base\services\core\java\com\android\server\ConnectivityService.java
建立连接时读取 "net.hostname" 属性值是否为空,如果为空则获取设备id,加上"android-"前缀并设置到属性:
protected ConnectivityService(Context context, INetworkManagementService netManager,
INetworkStatsService statsService, INetworkPolicyManager policyManager,
IpConnectivityLog logger) {
mHandlerThread = new HandlerThread("ConnectivityServiceThread");
mHandlerThread.start();
mHandler = new InternalHandler(mHandlerThread.getLooper());
mTrackerHandler = new NetworkStateTrackerHandler(mHandlerThread.getLooper());
// setup our unique device name
if (TextUtils.isEmpty(SystemProperties.get("net.hostname"))) {
String id = Settings.Secure.getString(context.getContentResolver(),
Settings.Secure.ANDROID_ID);
if (id != null && id.length() > 0) {
String name = new String("android-").concat(id);
SystemProperties.set("net.hostname", name);
}
}
......
}
2. \frameworks\base\services\net\java\android\net\dhcp\DhcpInformPacket.java
通过 addCommonClientTlvs() 接口获取设备ID并填入buffer:
/**
* Adds additional parameters to the INFORM packet.
*/
void finishPacket(ByteBuffer buffer) {
addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_INFORM);
addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
addCommonClientTlvs(buffer);
addTlv(buffer, DHCP_PARAMETER_LIST, mRequestedParams);
addTlvEnd(buffer);
}
调用到 \frameworks\base\services\net\java\android\net\dhcp\DhcpPacket.java 中获取 "net.hostname" 属性值,
添加到Tlv信息中(TLV是一种编码方式,由数据的类型Tag,数据的长度Length,数据的内容Value构成的一组数据报文)
protected void addCommonClientTlvs(ByteBuffer buf) {
addTlv(buf, DHCP_MAX_MESSAGE_SIZE, (short) MAX_LENGTH);
Option60 option60 = null;
if (mIface != null) {
option60 = OptionManager.getInstance().getOption60(mIface);
}
if (option60 != null && option60.getOptionSwitch() != 0
&& option60.getLogin() != null && option60.getPassword() != null){
byte[] dhcpPlusBuf = buildDhcpPlusMsg(option60.getLogin(),option60.getPassword());
addTlv(buf,DHCP_VENDOR_CLASS_ID,dhcpPlusBuf);
} else {
addTlv(buf, DHCP_VENDOR_CLASS_ID, getVendorId());
}
final String hn = getHostname();
if (!TextUtils.isEmpty(hn)) addTlv(buf, DHCP_HOST_NAME, hn);
}
getHostname() 实现:
private String getHostname() {
if (testOverrideHostname != null) return testOverrideHostname;
return SystemProperties.get("net.hostname");
}
addTlv() 实现:
/**
* Adds an optional parameter containing an array of bytes.
*/
protected static void addTlv(ByteBuffer buf, byte type, byte[] payload) {
if (payload != null) {
if (payload.length > MAX_OPTION_LEN) {
throw new IllegalArgumentException("DHCP option too long: "
+ payload.length + " vs. " + MAX_OPTION_LEN);
}
buf.put(type);
buf.put((byte) payload.length);
buf.put(payload);
}
}
编译及更新:
mmm frameworks/base/services/
adb push out/target/product/almond/system/framework/services.jar /system/framework/
adb push out/target/product/almond/system/framework/oat/arm64/services.odex /system/framework/oat/arm64/ (优化编译才有此目录)
二、通过build.prop文件配置设备名
1. 修改 /system/build.prop 最后添加,### 为自己设置的设备名:
net.hostname=###
2. 重启、重连wifi,从热点或路由器后台查看设备名即为修改后的名称。