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。