android ethernet

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MARTINGANG

最新推荐文章于 2024-06-24 01:33:15 发布

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分类专栏： Android network

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Lamdoc船长的宝藏：http://blog.youkuaiyun.com/lamdoc/article/category/1164160

android ethernet unplug/plug enable/disable 管理

android ethernet 管理，可以分为两类：

1. 是网线插拔，unplug/plug。

unplug 时， eth0 可以up, 但是IP 必须为0，因为打开internel时，必须快速出现连不上页面，而不是延迟好几十秒，才出现连不上。

plug in之后，IP 能自动恢复。

2. 是Setting里EthernetConfiguration 的勾选项。enable/disable。

disable ethernet 时， eth0 必须是down的， enable之后，才up，然后能自动恢复IP。

3. 是static ip configuration

NETMASK

DNS

GATEWAY

4个IP选项，静态IP设置。

android ethernet 设计的几个模块

分类： Android ethernet 2012-06-08 17:18 218人阅读评论(0) 收藏举报

ethernet related files:

1. packages/app/Settings/:    //Setting中添加选项代码
packages/apps/Settings/src/com/android/settings/ethernet/EthernetSettings.java
packages/apps/Settings/src/com/android/settings/ethernet/EthernetEnabler.java
packages/apps/Settings/src/com/android/settings/ethernet/EthernetConfigDialog.java

2. frameworks/base/ :

SystemUI:   //状态栏（status_bar）显示部分代码
frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/policy/NetworkController.java
frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java    //现实statusbar

ConnectivityService:
frameworks/base/services/java/com/android/server/ConnectivityService.java   //这里是ethernet部分程序的起始点

jni:
frameworks/base/core/jni/android_net_ethernet.cpp //新加的一些jni

本来就有的ethernet：
frameworks/base/services/java/com/android/server/EthernetService.java
frameworks/base/services/java/com/android/server/NetworkManagementService.java
frameworks/base/core/java/android/net/NetworkStats.java

新添加的ethernet：
frameworks/base/ethernet/* // 这是主要ethernet部分，java api 代码。
frameworks/base/ethernet/java/android/net/ethernet/EthernetManager.java

调试android ethernet 的常用命令

分类： Android ethernet 2012-06-08 17:20 124人阅读评论(0) 收藏举报

1. netcfg

netcfg //查看ip情况

netcfg eth0 up dhcp //通过dhcp 自动获取ip和网关

2. ifconfig

ifconfig eth0 128.224.156.81 up

ifconfig eth0 128.224.156.81 netmask 255.255.255.0 up

3. gateway 配置

route add default gw 192.168.0.1 dev eth0

4. dns 配置

echo "nameserver 128.224.160.11" > resolv.conf

nameserver 128.224.160.11

setprop net.dns1 128.224.160.11

setprop net.dns2 147.11.100.30

4. mac adddr
ifconfig eth0 hw ether 00:11:22:33:44:55

android ethernet的2个辅助模块 libnetutils 和 dhcpcd

1. 一个是 system/core/libnetutils/* , 即libnetutils.so 库. 这里面有两个.c经常会调用到

ifc_utils.c

dhcp_utils.c

java会通过 JNI （CPP）再调用到 C代码

2. 第二个是 /external/dhcpcd/*, 生成/system/bin/dhcpcd.

这个是守护进程 dhcpcd_eth0 会用到的工具。

ConnectivityService 中调用 EthernetStateTracker 和 EthernetService

分类： Android ethernet 2012-06-09 16:14 342人阅读评论(2) 收藏举报

u最近在研究android 中的 ethernet 部分，主要集中在上层JAVA service 和java api。

整个 android 系统的mobile, wifi，wimax 和 bluetooth 都是通过ConnectivitySerivice 来提供服务的。
android本身不自带ethernet服务，需要新加 android-x86 里拿的ics-ethernet patch。

接下来分析 ConnectivityService 是怎么提供 ethernet 服务的。

1. 最开始，ConnectivityService 中会创建 EthernetStateTracker 和 EthernetService。
frameworks/base/services/java/com/android/server/ConnectivityService.java：

[java] view plain copy print ?

case ConnectivityManager.TYPE_ETHERNET:
//mNetTrackers[netType] = EthernetDataTracker.getInstance();
//mNetTrackers[netType].startMonitoring(context, mHandler);
if(DBG) log("Starting Ethernet Service.");
//创建 EthernetStateTracker
EthernetStateTracker est=new EthernetStateTracker(context, mHandler);
//创建EthernetService
EthernetService ethService=new EthernetService(context, est);
<PRE class=java name="code"> //向ServiceManager 中添加 ETHERNET_SERVICE 服务
ServiceManager.addService(Context.ETHERNET_SERVICE, ethService);
mNetTrackers[ConnectivityManager.TYPE_ETHERNET]= est; //赋值EthernetStateTracker.
//调用EthernetStateTracker 的startMonitoring
est.startMonitoring(context, mHandler);
break;</PRE>
<PRE></PRE>
a. mNetTrackers 定义：
<PRE class=java name="code"> /**
* Sometimes we want to refer to the individual network state
* trackers separately, and sometimes we just want to treat them
* abstractly.
*/
private NetworkStateTracker mNetTrackers[];
//网络状态跟踪，no_connected, connecting, connected ，三种状态
</PRE>
b. EthernetStateTracker.startMonitoring():
<PRE class=java name="code"> public void startMonitoring(Context context, Handler target) {
if (localLOGV) Slog.v(TAG,"start to monitor the ethernet devices");
if (mServiceStarted) { //获得systemService 中 ethernet_service的上下文
mEM = (EthernetManager)context.getSystemService(Context.ETHERNET_SERVICE);
mContext = context;
mCsHandler = target;
int state = mEM.getState();
if (state != mEM.ETHERNET_STATE_DISABLED) {
if (state == mEM.ETHERNET_STATE_UNKNOWN) {
// maybe this is the first time we run, so set it to enabled
mEM.setEnabled(mEM.getDeviceNameList() != null); //set mEM to enabled.
} else {
try {
//if it's not the first time we run, reset the interface.
resetInterface();
} catch (UnknownHostException e) {
Slog.e(TAG, "Wrong ethernet configuration");
}
}
}
}
}
</PRE>
2. 创建 EthernetStateTracker :
frameworks/base/ethernet/java/android/net/ethernet/EthernetStateTracker.java
<DIV id=codeText class=codeText><PRE class=java name="code"> public EthernetStateTracker(Context context, Handler target){
//创建 NetworkInfo，可以用来查看网络状况
mNetworkInfo = new NetworkInfo(ConnectivityManager.TYPE_ETHERNET, 0,"ETH","");
mLinkProperties = new LinkProperties(); //网络链接属性
if (localLOGV) Slog.v(TAG,"Starts...");
//EthernetNative 通过 JNI 调用到 libnetutil.so 中去了。
if (EthernetNative.initEthernetNative()!= 0){
Slog.e(TAG,"Can not init ethernet device layers");
return;
}
if (localLOGV) Slog.v(TAG,"Successed");
mServiceStarted = true;
//创建 DHCP 线程
HandlerThread dhcpThread = new HandlerThread("DHCP Handler Thread");
dhcpThread.start();
mDhcpTarget = new DhcpHandler(dhcpThread.getLooper(),this);
mMonitor = new EthernetMonitor(this); //创建 EthernetMonitor
mDhcpInfo = new DhcpInfoInternal(); //创建 DhcpInfoInternal，用来描述DHCP IP配置
mDhcpInfo1 = new DhcpInfo(); //创建DhcpInfo, 用来描述static ip 配置
}</PRE>
a. DhcpHandler():
这个类不知道干啥的。。
<PRE class=java name="code"> private class DhcpHandler extends Handler {
public DhcpHandler(Looper looper, Handler target) {
super(looper);
mTrackerTarget = target; //赋值mTrackerTarget.
}
</PRE>
b. EthernetMonitor(): 这个会单独介绍
c. DhcpInfoInternal(): 这个应该是DhcpInfo的新一代。
frameworks/base/core/java/android/net/DhcpInfoInternal.java
<PRE class=java name="code">/**
* A simple object for retrieving the results of a DHCP request.
* Replaces (internally) the IPv4-only DhcpInfo class.
* @hide
*/
public class DhcpInfoInternal {
private final static String TAG = "DhcpInfoInternal";
public String ipAddress;
public int prefixLength;
public String dns1;
public String dns2;
public String serverAddress;
public int leaseDuration;
private Collection<RouteInfo> mRoutes;
</PRE>
d. DhcpInfo 类内容明显和 DhcpInfoInternal 不同:
frameworks/base/core/java/android/net/DhcpInfo.java
<PRE class=java name="code">/**
* A simple object for retrieving the results of a DHCP request.
*/
public class DhcpInfo implements Parcelable {
public int ipAddress;
public int gateway;
public int netmask;
public int dns1;
public int dns2;
public int serverAddress;
public int leaseDuration;
</PRE>
</DIV>
3.
创建 EthernetService：
frameworks/base/services/java/com/android/server/EthernetService.java
<PRE class=java name="code"> public EthernetService(Context context, EthernetStateTracker Tracker){
mTracker = Tracker;
mContext = context;
isEnabled = getPersistedState();
if (localLOGV==true) Slog.i(TAG,"Ethernet dev enabled "+ isEnabled);
getDeviceNameList(); //从驱动获得设备表
setState(isEnabled); //设置 enabled 状态
Slog.d(TAG,"xxha: ---------------------- StartPolling()");
mTracker.StartPolling(); //开始监听驱动层的事件信号
}</PRE>
a. getDeviceNameList() :
<PRE class=java name="code"> /**
* get all the ethernet device names
* @return interface name list on success, {@code null} on failure
*/
public String[] getDeviceNameList() {
return (scanDevice() > 0) ? DevName : null; //扫描设备
}
</PRE>
<PRE class=java name="code"> private int scanDevice() {
int i, j;
if ((i = EthernetNative.getInterfaceCnt()) == 0)
return 0;
DevName = new String[i];
for (j = 0; j < i; j++) {
DevName[j] = EthernetNative.getInterfaceName(j); //获取设备名eth0,sit0
if (DevName[j] == null)
break;
if (localLOGV) Slog.v(TAG, "device " + j + " name " + DevName[j]);
}
return i;
}
</PRE>
b. mTracker.StartPolling()
<PRE class=java name="code"> public void StartPolling() {
mMonitor.startMonitoring(); //这个也会调到EthernetMonitor 中的 startMonitoring（）去。
}
</PRE>
<PRE></PRE>

EthernetMornitor 与 EthernetStateTracker

分类： Android ethernet 2012-06-11 15:14 173人阅读评论(0) 收藏举报

EthernetMornitor 这个类位于: frameworks/base/ethernet/java/android/net/ethernet/EthernetMonitor.java

它会监听底层ethernet 状态的 event.

1. EthernetMonitor ：

[java] view plain copy print ?

/**
* Listens for events from kernel, and passes them on
* to the {@link EtherentStateTracker} for handling. Runs in its own thread.
*
* @hide
*/
public class EthernetMonitor {
private static final String TAG = "EthernetMonitor";
private static final int CONNECTED = 1;
private static final int DISCONNECTED = 2;
private static final int PHYUP = 3;
private static final String connectedEvent = "CONNECTED";
private static final String disconnectedEvent = "DISCONNECTED";
private static final int ADD_ADDR = 20;
private static final int RM_ADDR = 21;
private static final int NEW_LINK = 16;
private static final int DEL_LINK = 17;
private static final boolean localLOGV = false;
private EthernetStateTracker mTracker;
//EthernetMonitor 是 EthernetStateTraker 的一个辅助
public EthernetMonitor(EthernetStateTracker tracker) {
mTracker = tracker;
}

/**
 * Listens for events from kernel, and passes them on
 * to the {@link EtherentStateTracker} for handling. Runs in its own thread.
 *
 * @hide
 */
public class EthernetMonitor {
    private static final String TAG = "EthernetMonitor";
    private static final int CONNECTED = 1;
    private static final int DISCONNECTED = 2;
    private static final int PHYUP = 3;
    private static final String connectedEvent = "CONNECTED";
    private static final String disconnectedEvent = "DISCONNECTED";
    private static final int ADD_ADDR = 20;
    private static final int RM_ADDR = 21;
    private static final int NEW_LINK = 16;
    private static final int DEL_LINK = 17;
    private static final boolean localLOGV = false;

    private EthernetStateTracker mTracker;

    //EthernetMonitor 是 EthernetStateTraker 的一个辅助
    public EthernetMonitor(EthernetStateTracker tracker) {
        mTracker = tracker;
    }

a. startMonitoring（）：会在 EthernetStateTracker.StartPolling（）中调用此函数。

[java] view plain copy print ?

public void startMonitoring() {
new MonitorThread().start(); //线程开始
}
class MonitorThread extends Thread {
public MonitorThread() {
super("EthMonitor");
}
public void run() {
//noinspection InfiniteLoopStatement
for (;;) { //不断的在监听 kernel event
int index;
int i;
int cmd;
String dev;
if (localLOGV) Slog.v(TAG, "go poll events");
String eventName = EthernetNative.waitForEvent(); //wait for event
if (eventName == null) {
continue;
}
if (localLOGV) Slog.v(TAG, "get event " + eventName);
/*
* Map event name into event enum
*/
i = 0;
while (i < eventName.length()) {
index = eventName.substring(i).indexOf(":");
if (index == -1)
break;
dev = eventName.substring(i, index);
i += index + 1;
index = eventName.substring(i).indexOf(":");
if (index == -1)
break;
cmd = Integer.parseInt(eventName.substring(i, i+index));
i += index + 1;
//dev 指eth0, cmd 是event参数。
if (localLOGV) Slog.v(TAG, "dev: " + dev + " ev " + cmd);
switch (cmd) {
case DEL_LINK: //断开连接
handleEvent(dev, DISCONNECTED);
break;
case ADD_ADDR: //添加IP address，即链接成功
handleEvent(dev, CONNECTED);
break;
case NEW_LINK: //phy up 状态
handleEvent(dev, PHYUP);
break;
}
}
}
}

    public void startMonitoring() {
        new MonitorThread().start(); //线程开始
    }

    class MonitorThread extends Thread {
        public MonitorThread() {
            super("EthMonitor");
        }

        public void run() {
            //noinspection InfiniteLoopStatement
            for (;;) {     //不断的在监听 kernel event
                int index;
                int i;
                int cmd;
                String dev;

                if (localLOGV) Slog.v(TAG, "go poll events");

                String eventName = EthernetNative.waitForEvent(); //wait for event

                if (eventName == null) {
                    continue;
                }

                if (localLOGV) Slog.v(TAG, "get event " + eventName);

                /*
                 * Map event name into event enum
                 */
                i = 0;
                while (i < eventName.length()) {
                    index = eventName.substring(i).indexOf(":");
                    if (index == -1)
                        break;
                    dev = eventName.substring(i, index);
                    i += index + 1;
                    index = eventName.substring(i).indexOf(":");
                    if (index == -1)
                        break;
                    cmd = Integer.parseInt(eventName.substring(i, i+index));
                    i += index + 1;
                    //dev 指eth0, cmd 是event参数。  
                    if (localLOGV) Slog.v(TAG, "dev: " + dev + " ev " + cmd);
                    switch (cmd) {
                        case DEL_LINK: //断开连接
                            handleEvent(dev, DISCONNECTED);
                            break;
                        case ADD_ADDR:  //添加IP address，即链接成功
                            handleEvent(dev, CONNECTED);
                            break;
                        case NEW_LINK:  //phy up 状态
                            handleEvent(dev, PHYUP);
                            break;
                    }
                }
            }
        }

b. handleEvent(String ifname,int event)：

[java] view plain copy print ?

/**
* Handle all supplicant events except STATE-CHANGE
* @param event the event type
* @param remainder the rest of the string following the
* event name and " — "
*/
void handleEvent(String ifname,int event) {
switch (event) {
case DISCONNECTED:
mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.DISCONNECTED);
break;
case CONNECTED:
mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.CONNECTED);
break;
case PHYUP:
mTracker.notifyPhyConnected(ifname);
break;
default:
mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.FAILED);
break;
}
}

        /**
         * Handle all supplicant events except STATE-CHANGE
         * @param event the event type
         * @param remainder the rest of the string following the
         * event name and " — "
         */
        void handleEvent(String ifname,int event) {
            switch (event) {
                case DISCONNECTED:
                    mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.DISCONNECTED);
                    break;
                case CONNECTED:
                    mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.CONNECTED);
                    break;
                case PHYUP:
                    mTracker.notifyPhyConnected(ifname);
                    break;
                default:
                    mTracker.notifyStateChange(ifname,NetworkInfo.DetailedState.FAILED);
                    break;
            }
        }

c. EthernetStateTraker.notifyStateChange():

[java] view plain copy print ?

public void notifyStateChange(String ifname,DetailedState state) {
if (localLOGV) Slog.i(TAG, "report new state " + state.toString() + " on dev " + ifname);
if (ifname.equals(mInterfaceName)) { //判断eth0名称是否正确
if (localLOGV) Slog.v(TAG, "update network state tracker");
synchronized(this) { //发送 Connected or Disconnected 消息
this.sendEmptyMessage(state.equals(DetailedState.CONNECTED)
? EVENT_HW_CONNECTED : EVENT_HW_DISCONNECTED);
}
}
}

    public void notifyStateChange(String ifname,DetailedState state) {
        if (localLOGV) Slog.i(TAG, "report new state " + state.toString() + " on dev " + ifname);
        if (ifname.equals(mInterfaceName)) { //判断eth0名称是否正确
            if (localLOGV) Slog.v(TAG, "update network state tracker");
            synchronized(this) { //发送 Connected or Disconnected 消息
                this.sendEmptyMessage(state.equals(DetailedState.CONNECTED)
                    ? EVENT_HW_CONNECTED : EVENT_HW_DISCONNECTED);
            }
        }
    }

d. EthernetStateTraker.notifyPhyConnected():

[java] view plain copy print ?

public void notifyPhyConnected(String ifname) {
if (localLOGV) Slog.v(TAG, "report interface is up for " + ifname);
synchronized(this) { //发送Phy connected 消息
this.sendEmptyMessage(EVENT_HW_PHYCONNECTED);
}
}

    public void notifyPhyConnected(String ifname) {
        if (localLOGV) Slog.v(TAG, "report interface is up for " + ifname);
        synchronized(this) { //发送Phy connected 消息
            this.sendEmptyMessage(EVENT_HW_PHYCONNECTED); 
        }
    }

2. 发送消息之后，EthernetStateTraker 会handleMessage():

[java] view plain copy print ?

public void handleMessage(Message msg) {
synchronized (this) {
switch (msg.what) {
case EVENT_INTERFACE_CONFIGURATION_SUCCEEDED: //连接成功
if (localLOGV) Slog.i(TAG, "received configured succeeded, stack=" + mStackConnected + " HW=" + mHWConnected);
mStackConnected = true;
if (mHWConnected)
setState(true, msg.what);
break;
case EVENT_INTERFACE_CONFIGURATION_FAILED: //链接失败
mStackConnected = false;
//start to retry ?
break;
case EVENT_HW_CONNECTED: //HW连接上了
if (localLOGV) Slog.i(TAG, "received HW connected, stack=" + mStackConnected + " HW=" + mHWConnected);
mHWConnected = true;
if (mStackConnected)
setState(true, msg.what);
break;
case EVENT_HW_DISCONNECTED: //hw断开
if (localLOGV) Slog.i(TAG, "received disconnected events, stack=" + mStackConnected + " HW=" + mHWConnected);
setState(false, msg.what);
break;
case EVENT_HW_PHYCONNECTED: //phy 连上
if (localLOGV) Slog.i(TAG, "interface up event, kick off connection request");
if (!mStartingDhcp) {
int state = mEM.getState();
if (state != mEM.ETHERNET_STATE_DISABLED) {
EthernetDevInfo info = mEM.getSavedConfig(); //获得以前已有的连接IP
if (info != null && mEM.isConfigured()) {
try {
configureInterface(info); //配置IP
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
Slog.e(TAG, "Cannot configure interface");
}
}
}
}
setState(true, msg.what);
break;
}
}
}

    public void handleMessage(Message msg) {

        synchronized (this) {
            switch (msg.what) {
            case EVENT_INTERFACE_CONFIGURATION_SUCCEEDED:  //连接成功
                if (localLOGV) Slog.i(TAG, "received configured succeeded, stack=" + mStackConnected + " HW=" + mHWConnected);
                mStackConnected = true;
                if (mHWConnected)
                    setState(true, msg.what);
                break;
            case EVENT_INTERFACE_CONFIGURATION_FAILED:  //链接失败
                mStackConnected = false;
                //start to retry ?
                break;
            case EVENT_HW_CONNECTED:  //HW连接上了
                if (localLOGV) Slog.i(TAG, "received HW connected, stack=" + mStackConnected + " HW=" + mHWConnected);
                mHWConnected = true;
                if (mStackConnected)
                    setState(true, msg.what);
                break;
            case EVENT_HW_DISCONNECTED: //hw断开
                if (localLOGV) Slog.i(TAG, "received disconnected events, stack=" + mStackConnected + " HW=" + mHWConnected);
                setState(false, msg.what);
                break;
            case EVENT_HW_PHYCONNECTED: //phy 连上
                if (localLOGV) Slog.i(TAG, "interface up event, kick off connection request");
                if (!mStartingDhcp) {
                    int state = mEM.getState();
                    if (state != mEM.ETHERNET_STATE_DISABLED) {
                        EthernetDevInfo info = mEM.getSavedConfig(); //获得以前已有的连接IP
                        if (info != null && mEM.isConfigured()) {
                            try {
                                configureInterface(info); //配置IP
                            } catch (UnknownHostException e) {
                                 // TODO Auto-generated catch block
                                 //e.printStackTrace();
                                 Slog.e(TAG, "Cannot configure interface");
                            }
                        }
                    }
                }

                setState(true, msg.what);
                break;
            }
        }
    }

3. setState（boolean state, int event）：

[java] view plain copy print ?

private void setState(boolean state, int event) {
if (mNetworkInfo.isConnected() != state) {
if (state) { //connected or disconnected.
mNetworkInfo.setDetailedState(DetailedState.CONNECTED, null, null);
} else {
mNetworkInfo.setDetailedState(DetailedState.DISCONNECTED, null, null);
stopInterface(true);
}
mNetworkInfo.setIsAvailable(state);
postNotification(event);
}
}

    private void setState(boolean state, int event) {
        if (mNetworkInfo.isConnected() != state) {
            if (state) { //connected or disconnected.
                mNetworkInfo.setDetailedState(DetailedState.CONNECTED, null, null);
            } else {
                mNetworkInfo.setDetailedState(DetailedState.DISCONNECTED, null, null);
                stopInterface(true);
            }
            mNetworkInfo.setIsAvailable(state);
            postNotification(event);
        }
    }

a. stopInterface():

[java] view plain copy print ?

/**
* Stop etherent interface
* @param suspend {@code false} disable the interface {@code true} only reset the connection without disable the interface
* @return true
*/
public boolean stopInterface(boolean suspend) {
if (mEM != null) {
EthernetDevInfo info = mEM.getSavedConfig();
if (info != null && mEM.isConfigured()) {
synchronized (mDhcpTarget) {
mInterfaceStopped = true;
if (localLOGV) Slog.i(TAG, "stop dhcp and interface");
// stop DhcpHandler Looper
mDhcpTarget.removeMessages(EVENT_DHCP_START);
String ifname = info.getIfName(); // eth0
if (!NetworkUtils.stopDhcp(ifname)) { //stop dhcpcd_eth0 service
if (localLOGV) Slog.w(TAG, "Could not stop DHCP");
}
//reset eth0, remove route and ip
NetworkUtils.resetConnections(ifname, NetworkUtils.RESET_ALL_ADDRESSES);
NetworkUtils.removeDefaultRoute(ifname);
mStartingDhcp = false;
if (!suspend) // if suspend = false, turn eth0 to down.
NetworkUtils.disableInterface(ifname);
mLinkProperties.clear();
}
}
}
return true;
}

    /**
     * Stop etherent interface
     * @param suspend {@code false} disable the interface {@code true} only reset the connection without disable the interface
     * @return true
     */
    public boolean stopInterface(boolean suspend) {
        if (mEM != null) {

            EthernetDevInfo info = mEM.getSavedConfig();
            if (info != null && mEM.isConfigured()) {
                synchronized (mDhcpTarget) {
                    mInterfaceStopped = true;
                    if (localLOGV) Slog.i(TAG, "stop dhcp and interface");

                    // stop DhcpHandler Looper
                    mDhcpTarget.removeMessages(EVENT_DHCP_START);
                    String ifname = info.getIfName(); // eth0

                    if (!NetworkUtils.stopDhcp(ifname)) { //stop dhcpcd_eth0 service
                        if (localLOGV) Slog.w(TAG, "Could not stop DHCP");
                    }

                    //reset eth0, remove route and ip
                    NetworkUtils.resetConnections(ifname, NetworkUtils.RESET_ALL_ADDRESSES);
                    NetworkUtils.removeDefaultRoute(ifname);
                    mStartingDhcp = false;

                    if (!suspend) // if suspend = false, turn eth0 to down.
                        NetworkUtils.disableInterface(ifname);

                    mLinkProperties.clear();
                }
            }
        }
        return true;
    }

b. postNotification(int event)，给ConnectivityService 发送 event state changed 消息.

[java] view plain copy print ?

private void postNotification(int event) {
Message msg = mCsHandler.obtainMessage(EVENT_STATE_CHANGED, new NetworkInfo(mNetworkInfo));
msg.sendToTarget();
}

    private void postNotification(int event) {
        Message msg = mCsHandler.obtainMessage(EVENT_STATE_CHANGED, new NetworkInfo(mNetworkInfo));
        msg.sendToTarget();
    }

4. configureInterface(EthernetDevInfo info), 配置 IP 函数：

[java] view plain copy print ?

private boolean configureInterface(EthernetDevInfo info) throws UnknownHostException {
mStackConnected = false;
mHWConnected = false;
mInterfaceStopped = false;
mStartingDhcp = true;
//DHCP 方式获得 IP
if (info.getConnectMode().equals(EthernetDevInfo.ETHERNET_CONN_MODE_DHCP)) {
if (localLOGV) Slog.i(TAG, "trigger dhcp for device " + info.getIfName());
sDnsPropNames = new String[] {
"dhcp." + mInterfaceName + ".dns1",
"dhcp." + mInterfaceName + ".dns2"
};
mDhcpTarget.sendEmptyMessage(EVENT_DHCP_START);
} else { //static IP 设置方式
int event;
sDnsPropNames = new String[] {
"net." + mInterfaceName + ".dns1",
"net." + mInterfaceName + ".dns2"
};
//从输入栏获取 ip, gateway, netmask, dns 值
mDhcpInfo1.ipAddress = lookupHost(info.getIpAddress());
mDhcpInfo1.gateway = lookupHost(info.getRouteAddr());
mDhcpInfo1.netmask = lookupHost(info.getNetMask());
mDhcpInfo1.dns1 = lookupHost(info.getDnsAddr());
mDhcpInfo1.dns2 = 0;
if (localLOGV) Slog.i(TAG, "set ip manually " + mDhcpInfo1.toString());
//配置之前擦除以前的route
NetworkUtils.removeDefaultRoute(info.getIfName());
//配置成功
if (NetworkUtils.configureInterface(info.getIfName(), mDhcpInfo1)) {
event = EVENT_INTERFACE_CONFIGURATION_SUCCEEDED;
SystemProperties.set("net.dns1", info.getDnsAddr());
SystemProperties.set("net." + info.getIfName() + ".dns1", info.getDnsAddr());
SystemProperties.set("net." + info.getIfName() + ".dns2", "0.0.0.0");
if (localLOGV)
Slog.v(TAG, "Static IP configuration succeeded");
} else { //配置失败
event = EVENT_INTERFACE_CONFIGURATION_FAILED;
if (localLOGV) Slog.w(TAG, "Static IP configuration failed");
}
this.sendEmptyMessage(event); //给EthernetStateTracker发送message
}
return true;
}
<PRE></PRE>5. resetInterface(), 这个和stopInterface 差不多：
<PRE class=java name="code"> /**
* reset ethernet interface
* @return true
* @throws UnknownHostException
*/
public boolean resetInterface() throws UnknownHostException{
/*
* This will guide us to enabled the enabled device
*/
if (mEM != null) {
EthernetDevInfo info = mEM.getSavedConfig();
if (info != null && mEM.isConfigured()) {
synchronized (this) {
mInterfaceName = info.getIfName();
if (localLOGV) Slog.i(TAG, "reset device " + mInterfaceName);
NetworkUtils.resetConnections(mInterfaceName, NetworkUtils.RESET_ALL_ADDRESSES);
// Stop DHCP
if (mDhcpTarget != null) {
mDhcpTarget.removeMessages(EVENT_DHCP_START);
}
if (!NetworkUtils.stopDhcp(mInterfaceName)) {
if (localLOGV) Slog.w(TAG, "Could not stop DHCP");
}
mLinkProperties.clear();
configureInterface(info); //比stopInterface 多了一步重新配置IP。
}
}
}
return true;
}
</PRE>
<PRE></PRE>
<PRE></PRE>
<PRE></PRE>
<PRE></PRE>

NetWorkUtils 和 android_net_NetUtils.cpp

分类： Android ethernet 2012-06-11 18:20 249人阅读评论(0) 收藏举报

EthernetStateTracker 中会，用到 NetWorkUtils 类中的一些函数，这些函数，会调用JNI：　android_net_NetUtils.cpp，　然后调到　ｌｉｂｎｅｔｕｔｉｌｓ　库中去。

如：

NetworkUtils.disableInterface(ifname);

NetworkUtils.runDhcp(mInterfaceName, mDhcpInfo)；

NetworkUtils.stopDhcp(mInterfaceName)；

NetworkUtils.resetConnections(mInterfaceName, NetworkUtils.RESET_ALL_ADDRESSES);

NetworkUtils.configureInterface(info.getIfName(), mDhcpInfo1)；

NetworkUtils.removeDefaultRoute(ifname);

等等。

１.　ＮｅｔｗｏｒｋＵｔｉｌｓ　类： frameworks/base/core/java/android/net/NetworkUtils.java

[java] view plain copy print ?

/**
* Native methods for managing network interfaces.
*
* {@hide}
*/
public class NetworkUtils {
private static final String TAG = "NetworkUtils";
/** Bring the named network interface up. */
public native static int enableInterface(String interfaceName);
/** Bring the named network interface down. */
public native static int disableInterface(String interfaceName);
/** Remove the default route for the named interface. */
public native static int removeDefaultRoute(String interfaceName);
/** Setting bit 0 indicates reseting of IPv4 addresses required */
public static final int RESET_IPV4_ADDRESSES = 0x01;
/** Setting bit 1 indicates reseting of IPv4 addresses required */
public static final int RESET_IPV6_ADDRESSES = 0x02;
/** Reset all addresses */
public static final int RESET_ALL_ADDRESSES = RESET_IPV4_ADDRESSES | RESET_IPV6_ADDRESSES;
/**
* Reset IPv6 or IPv4 sockets that are connected via the named interface.
*
* @param interfaceName is the interface to reset
* @param mask {@see #RESET_IPV4_ADDRESSES} and {@see #RESET_IPV6_ADDRESSES}
*/
public native static int resetConnections(String interfaceName, int mask);
/**
* Start the DHCP client daemon, in order to have it request addresses
* for the named interface, and then configure the interface with those
* addresses. This call blocks until it obtains a result (either success
* or failure) from the daemon.
* @param interfaceName the name of the interface to configure
* @param ipInfo if the request succeeds, this object is filled in with
* the IP address information.
* @return {@code true} for success, {@code false} for failure
*/
public native static boolean runDhcp(String interfaceName, DhcpInfoInternal ipInfo);
/**
* Initiate renewal on the Dhcp client daemon. This call blocks until it obtains
* a result (either success or failure) from the daemon.
* @param interfaceName the name of the interface to configure
* @param ipInfo if the request succeeds, this object is filled in with
* the IP address information.
* @return {@code true} for success, {@code false} for failure
*/
public native static boolean runDhcpRenew(String interfaceName, DhcpInfoInternal ipInfo);
/**
* Shut down the DHCP client daemon.
* @param interfaceName the name of the interface for which the daemon
* should be stopped
* @return {@code true} for success, {@code false} for failure
*/
public native static boolean stopDhcp(String interfaceName);
/**
* When static IP configuration has been specified, configure the network
* interface according to the values supplied.
* @param interfaceName the name of the interface to configure
* @param ipInfo the IP address, default gateway, and DNS server addresses
* with which to configure the interface.
* @return {@code true} for success, {@code false} for failure
*/
public static boolean configureInterface(String interfaceName, DhcpInfo ipInfo) {
return configureNative(interfaceName,
ipInfo.ipAddress,
ipInfo.netmask,
ipInfo.gateway,
ipInfo.dns1,
ipInfo.dns2);
}
private native static boolean configureNative(
String interfaceName, int ipAddress, int netmask, int gateway, int dns1, int dns2);

/**
 * Native methods for managing network interfaces.
 *
 * {@hide}
 */
public class NetworkUtils {

    private static final String TAG = "NetworkUtils";

    /** Bring the named network interface up. */
    public native static int enableInterface(String interfaceName);

    /** Bring the named network interface down. */
    public native static int disableInterface(String interfaceName);

    /** Remove the default route for the named interface. */
    public native static int removeDefaultRoute(String interfaceName);

    /** Setting bit 0 indicates reseting of IPv4 addresses required */
    public static final int RESET_IPV4_ADDRESSES = 0x01;

    /** Setting bit 1 indicates reseting of IPv4 addresses required */
    public static final int RESET_IPV6_ADDRESSES = 0x02;

    /** Reset all addresses */
    public static final int RESET_ALL_ADDRESSES = RESET_IPV4_ADDRESSES | RESET_IPV6_ADDRESSES;

    /**
     * Reset IPv6 or IPv4 sockets that are connected via the named interface.
     *
     * @param interfaceName is the interface to reset
     * @param mask {@see #RESET_IPV4_ADDRESSES} and {@see #RESET_IPV6_ADDRESSES}
     */
    public native static int resetConnections(String interfaceName, int mask);

    /**
     * Start the DHCP client daemon, in order to have it request addresses
     * for the named interface, and then configure the interface with those
     * addresses. This call blocks until it obtains a result (either success
     * or failure) from the daemon.
     * @param interfaceName the name of the interface to configure
     * @param ipInfo if the request succeeds, this object is filled in with
     * the IP address information.
     * @return {@code true} for success, {@code false} for failure
     */
    public native static boolean runDhcp(String interfaceName, DhcpInfoInternal ipInfo);


    /**
     * Initiate renewal on the Dhcp client daemon. This call blocks until it obtains
     * a result (either success or failure) from the daemon.
     * @param interfaceName the name of the interface to configure
     * @param ipInfo if the request succeeds, this object is filled in with
     * the IP address information.
     * @return {@code true} for success, {@code false} for failure
     */
    public native static boolean runDhcpRenew(String interfaceName, DhcpInfoInternal ipInfo);

    /**
     * Shut down the DHCP client daemon.
     * @param interfaceName the name of the interface for which the daemon
     * should be stopped
     * @return {@code true} for success, {@code false} for failure
     */
    public native static boolean stopDhcp(String interfaceName);
    /**
     * When static IP configuration has been specified, configure the network
     * interface according to the values supplied.
     * @param interfaceName the name of the interface to configure
     * @param ipInfo the IP address, default gateway, and DNS server addresses
     * with which to configure the interface.
     * @return {@code true} for success, {@code false} for failure
     */
    public static boolean configureInterface(String interfaceName, DhcpInfo ipInfo) {
        return configureNative(interfaceName,
            ipInfo.ipAddress,
            ipInfo.netmask,
            ipInfo.gateway,
            ipInfo.dns1,
            ipInfo.dns2);
    }

    private native static boolean configureNative(
        String interfaceName, int ipAddress, int netmask, int gateway, int dns1, int dns2);

２.　android_net_NetUtils.cpp　ＪＮＩ　中的函数映射关系。

[cpp] view plain copy print ?

/*
* JNI registration.
*/
static JNINativeMethod gNetworkUtilMethods[] = {
/* name, signature, funcPtr */
{ "enableInterface", "(Ljava/lang/String;)I", (void *)android_net_utils_enableInterface },
{ "disableInterface", "(Ljava/lang/String;)I", (void *)android_net_utils_disableInterface },
{ "resetConnections", "(Ljava/lang/String;I)I", (void *)android_net_utils_resetConnections },
{ "removeDefaultRoute", "(Ljava/lang/String;)I", (void *)android_net_utils_removeDefaultRoute },
{ "runDhcp", "(Ljava/lang/String;Landroid/net/DhcpInfoInternal;)Z", (void *)android_net_utils_runDhcp },
{ "runDhcpRenew", "(Ljava/lang/String;Landroid/net/DhcpInfoInternal;)Z", (void *)android_net_utils_runDhcpRenew },
{ "stopDhcp", "(Ljava/lang/String;)Z", (void *)android_net_utils_stopDhcp },
{ "releaseDhcpLease", "(Ljava/lang/String;)Z", (void *)android_net_utils_releaseDhcpLease },
{ "getDhcpError", "()Ljava/lang/String;", (void*) android_net_utils_getDhcpError },
{ "configureNative", "(Ljava/lang/String;IIIII)Z", (void *)android_net_utils_configureInterface },
};

/*
 * JNI registration.
 */
static JNINativeMethod gNetworkUtilMethods[] = {
    /* name, signature, funcPtr */

    { "enableInterface", "(Ljava/lang/String;)I",  (void *)android_net_utils_enableInterface },
    { "disableInterface", "(Ljava/lang/String;)I",  (void *)android_net_utils_disableInterface },
    { "resetConnections", "(Ljava/lang/String;I)I",  (void *)android_net_utils_resetConnections },
    { "removeDefaultRoute", "(Ljava/lang/String;)I",  (void *)android_net_utils_removeDefaultRoute },
    { "runDhcp", "(Ljava/lang/String;Landroid/net/DhcpInfoInternal;)Z",  (void *)android_net_utils_runDhcp },
    { "runDhcpRenew", "(Ljava/lang/String;Landroid/net/DhcpInfoInternal;)Z",  (void *)android_net_utils_runDhcpRenew },
    { "stopDhcp", "(Ljava/lang/String;)Z",  (void *)android_net_utils_stopDhcp },
    { "releaseDhcpLease", "(Ljava/lang/String;)Z",  (void *)android_net_utils_releaseDhcpLease },
    { "getDhcpError", "()Ljava/lang/String;", (void*) android_net_utils_getDhcpError },
    { "configureNative", "(Ljava/lang/String;IIIII)Z",  (void *)android_net_utils_configureInterface },
};

3. enableInterface(), diableInterface() , resetConnection():

[cpp] view plain copy print ?

static jint android_net_utils_enableInterface(JNIEnv* env, jobject clazz, jstring ifname)
{
int result;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
result = ::ifc_enable(nameStr); //这里就会调用到 libnetutils 中的 ifc_utils.c 去
env->ReleaseStringUTFChars(ifname, nameStr);
return (jint)result;
}
static jint android_net_utils_disableInterface(JNIEnv* env, jobject clazz, jstring ifname)
{
int result;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
result = ::ifc_disable(nameStr);
env->ReleaseStringUTFChars(ifname, nameStr);
return (jint)result;
}
static jint android_net_utils_resetConnections(JNIEnv* env, jobject clazz,
jstring ifname, jint mask)
{
int result;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
LOGD("android_net_utils_resetConnections in env=%p clazz=%p iface=%s mask=0x%x\n",
env, clazz, nameStr, mask);
result = ::ifc_reset_connections(nameStr, mask);
env->ReleaseStringUTFChars(ifname, nameStr);
return (jint)result;
}

static jint android_net_utils_enableInterface(JNIEnv* env, jobject clazz, jstring ifname)
{
    int result;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    result = ::ifc_enable(nameStr); //这里就会调用到 libnetutils 中的 ifc_utils.c 去
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jint)result;
}

static jint android_net_utils_disableInterface(JNIEnv* env, jobject clazz, jstring ifname)
{
    int result;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    result = ::ifc_disable(nameStr);
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jint)result;
}

static jint android_net_utils_resetConnections(JNIEnv* env, jobject clazz,
      jstring ifname, jint mask)
{
    int result;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);

    LOGD("android_net_utils_resetConnections in env=%p clazz=%p iface=%s mask=0x%x\n",
          env, clazz, nameStr, mask);

    result = ::ifc_reset_connections(nameStr, mask);
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jint)result;
}

4. runDhcp（）， stopDhcp():

[java] view plain copy print ?

static jboolean android_net_utils_runDhcpCommon(JNIEnv* env, jobject clazz, jstring ifname,
jobject info, bool renew)
{
int result;
char ipaddr[PROPERTY_VALUE_MAX];
uint32_t prefixLength;
char gateway[PROPERTY_VALUE_MAX];
char dns1[PROPERTY_VALUE_MAX];
char dns2[PROPERTY_VALUE_MAX];
char server[PROPERTY_VALUE_MAX];
uint32_t lease;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
if (nameStr == NULL) return (jboolean)false;
if (renew) {
result = ::dhcp_do_request_renew(nameStr, ipaddr, gateway, &prefixLength,
dns1, dns2, server, &lease);
} else {
result = ::dhcp_do_request(nameStr, ipaddr, gateway, &prefixLength,
dns1, dns2, server, &lease); //调用 dhcp_utils.c 中的函数，获取route
}
env->ReleaseStringUTFChars(ifname, nameStr);
if (result == 0) {
env->SetObjectField(info, dhcpInfoInternalFieldIds.ipaddress, env->NewStringUTF(ipaddr));
// set the gateway
jclass cls = env->FindClass("java/net/InetAddress");
jmethodID method = env->GetStaticMethodID(cls, "getByName",
"(Ljava/lang/String;)Ljava/net/InetAddress;");
jvalue args[1];
args[0].l = env->NewStringUTF(gateway);
jobject inetAddressObject = env->CallStaticObjectMethodA(cls, method, args);
if (!env->ExceptionOccurred()) {
cls = env->FindClass("android/net/RouteInfo");
method = env->GetMethodID(cls, "<init>", "(Ljava/net/InetAddress;)V");
args[0].l = inetAddressObject;
jobject routeInfoObject = env->NewObjectA(cls, method, args);
cls = env->FindClass("android/net/DhcpInfoInternal");
method = env->GetMethodID(cls, "addRoute", "(Landroid/net/RouteInfo;)V");
args[0].l = routeInfoObject;
env->CallVoidMethodA(info, method, args);
} else {
// if we have an exception (host not found perhaps), just don't add the route
env->ExceptionClear();
}
env->SetIntField(info, dhcpInfoInternalFieldIds.prefixLength, prefixLength);
env->SetObjectField(info, dhcpInfoInternalFieldIds.dns1, env->NewStringUTF(dns1));
env->SetObjectField(info, dhcpInfoInternalFieldIds.dns2, env->NewStringUTF(dns2));
env->SetObjectField(info, dhcpInfoInternalFieldIds.serverAddress,
env->NewStringUTF(server));
env->SetIntField(info, dhcpInfoInternalFieldIds.leaseDuration, lease);
}
return (jboolean)(result == 0);
}

static jboolean android_net_utils_runDhcpCommon(JNIEnv* env, jobject clazz, jstring ifname,
        jobject info, bool renew)
{
    int result;
    char  ipaddr[PROPERTY_VALUE_MAX];
    uint32_t prefixLength;
    char gateway[PROPERTY_VALUE_MAX];
    char    dns1[PROPERTY_VALUE_MAX];
    char    dns2[PROPERTY_VALUE_MAX];
    char  server[PROPERTY_VALUE_MAX];
    uint32_t lease;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    if (nameStr == NULL) return (jboolean)false;

    if (renew) {
        result = ::dhcp_do_request_renew(nameStr, ipaddr, gateway, &prefixLength,
                dns1, dns2, server, &lease);
    } else {
        result = ::dhcp_do_request(nameStr, ipaddr, gateway, &prefixLength,
                dns1, dns2, server, &lease); //调用 dhcp_utils.c 中的函数，获取route
    }

    env->ReleaseStringUTFChars(ifname, nameStr);
    if (result == 0) {
        env->SetObjectField(info, dhcpInfoInternalFieldIds.ipaddress, env->NewStringUTF(ipaddr));

        // set the gateway
        jclass cls = env->FindClass("java/net/InetAddress");
        jmethodID method = env->GetStaticMethodID(cls, "getByName",
                "(Ljava/lang/String;)Ljava/net/InetAddress;");
        jvalue args[1];
        args[0].l = env->NewStringUTF(gateway);
        jobject inetAddressObject = env->CallStaticObjectMethodA(cls, method, args);

        if (!env->ExceptionOccurred()) {
            cls = env->FindClass("android/net/RouteInfo");
            method = env->GetMethodID(cls, "<init>", "(Ljava/net/InetAddress;)V");
            args[0].l = inetAddressObject;
            jobject routeInfoObject = env->NewObjectA(cls, method, args);

            cls = env->FindClass("android/net/DhcpInfoInternal");
            method = env->GetMethodID(cls, "addRoute", "(Landroid/net/RouteInfo;)V");
            args[0].l = routeInfoObject;
            env->CallVoidMethodA(info, method, args);
        } else {
            // if we have an exception (host not found perhaps), just don't add the route
            env->ExceptionClear();
        }

        env->SetIntField(info, dhcpInfoInternalFieldIds.prefixLength, prefixLength);
        env->SetObjectField(info, dhcpInfoInternalFieldIds.dns1, env->NewStringUTF(dns1));
        env->SetObjectField(info, dhcpInfoInternalFieldIds.dns2, env->NewStringUTF(dns2));
        env->SetObjectField(info, dhcpInfoInternalFieldIds.serverAddress,
                env->NewStringUTF(server));
        env->SetIntField(info, dhcpInfoInternalFieldIds.leaseDuration, lease);
    }
    return (jboolean)(result == 0);
}

[cpp] view plain copy print ?

static jboolean android_net_utils_runDhcp(JNIEnv* env, jobject clazz, jstring ifname, jobject info)
{
return android_net_utils_runDhcpCommon(env, clazz, ifname, info, false);
}
static jboolean android_net_utils_runDhcpRenew(JNIEnv* env, jobject clazz, jstring ifname, jobject info)
{
return android_net_utils_runDhcpCommon(env, clazz, ifname, info, true);
}
static jboolean android_net_utils_stopDhcp(JNIEnv* env, jobject clazz, jstring ifname)
{
int result;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
result = ::dhcp_stop(nameStr); // 这个调用 libnetutils 中的 dhcp_utils.c
env->ReleaseStringUTFChars(ifname, nameStr);
return (jboolean)(result == 0);
}

static jboolean android_net_utils_runDhcp(JNIEnv* env, jobject clazz, jstring ifname, jobject info)
{
    return android_net_utils_runDhcpCommon(env, clazz, ifname, info, false);
}

static jboolean android_net_utils_runDhcpRenew(JNIEnv* env, jobject clazz, jstring ifname, jobject info)
{
    return android_net_utils_runDhcpCommon(env, clazz, ifname, info, true);
}


static jboolean android_net_utils_stopDhcp(JNIEnv* env, jobject clazz, jstring ifname)
{
    int result;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    result = ::dhcp_stop(nameStr); // 这个调用 libnetutils 中的 dhcp_utils.c 
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jboolean)(result == 0);
}

5. 新添加的2个函数： removeDefaultRoute（）和 configureInterface（）：

[cpp] view plain copy print ?

static jint android_net_utils_removeDefaultRoute(JNIEnv* env, jobject clazz, jstring ifname)
{
int result;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
result = ::ifc_remove_default_route(nameStr);
env->ReleaseStringUTFChars(ifname, nameStr);
return (jint)result;
}
static jboolean android_net_utils_configureInterface(JNIEnv* env,
jobject clazz,
jstring ifname,
jint ipaddr,
jint mask,
jint gateway,
jint dns1,
jint dns2)
{
int result;
uint32_t lease;
const char *nameStr = env->GetStringUTFChars(ifname, NULL);
result = ::ifc_configure(nameStr, ipaddr, mask, gateway, dns1, dns2);
env->ReleaseStringUTFChars(ifname, nameStr);
return (jboolean)(result == 0);
}

static jint android_net_utils_removeDefaultRoute(JNIEnv* env, jobject clazz, jstring ifname)
{
    int result;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    result = ::ifc_remove_default_route(nameStr);
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jint)result;
}

static jboolean android_net_utils_configureInterface(JNIEnv* env,
        jobject clazz,
        jstring ifname,
        jint ipaddr,
        jint mask,
        jint gateway,
        jint dns1,
        jint dns2)
{
    int result;
    uint32_t lease;

    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
    result = ::ifc_configure(nameStr, ipaddr, mask, gateway, dns1, dns2);
    env->ReleaseStringUTFChars(ifname, nameStr);
    return (jboolean)(result == 0);
}

6. libnetutils.so C 库导出来的函数名, 这里主要用到了 ifc_utils.c 和 dhcp_utils.c 中的一些函数：

[cpp] view plain copy print ?

extern "C" {
int ifc_enable(const char *ifname);
int ifc_disable(const char *ifname);
int ifc_reset_connections(const char *ifname, int reset_mask);
int ifc_remove_default_route(const char *ifname);
int ifc_configure(const char *ifname,
in_addr_t address,
in_addr_t prefixLength,
in_addr_t gateway,
in_addr_t dns1,
in_addr_t dns2);
int dhcp_do_request(const char *ifname,
const char *ipaddr,
const char *gateway,
uint32_t *prefixLength,
const char *dns1,
const char *dns2,
const char *server,
uint32_t *lease);
int dhcp_do_request_renew(const char *ifname,
const char *ipaddr,
const char *gateway,
uint32_t *prefixLength,
const char *dns1,
const char *dns2,
const char *server,
uint32_t *lease);
int dhcp_stop(const char *ifname);
int dhcp_release_lease(const char *ifname);
char *dhcp_get_errmsg();
}

dhcpcd守护进程分析

最近在调android ethernet功能，android本身不带 ethernet 功能，需要打patch。这个patch可以在setting里出来 ethernet configuration 选项。即添加了用户配置IP的功能。
我打上patch之后，点击选上DHCP功能，结果路由器一直不能自动分配IP。

经检测，命令行里运行 netcfg eth0 up dhcp 时，ethernet能被正常启动，DHCP能分配到IP。

但是Setting里选上时，dhcp却不能正常分配IP。这很费解，我先后查看了，
/system/core/libnetutils/*
/externel/dhcpcd/*
发现都没什么问题。

在Setting中点击turn on ethernet选项时，从log看到能调到

E/EthernetStateTracker( 185): DhcpHandler: DHCP request failed: Timed out waiting for dhcpcd to start
D/EthernetStateTracker( 185): DhcpHandler: DHCP request started

说明patch是好的能正常工作，能正常掉用dhcp，只是DHCP运行不成功。

然后我查了 getprop: 显示 init.svc.dhcpcd_eth0 = stop
正常应该是running的，这样DHCP 才能运行成功。

最后调试了两天，才搞明白，原来是 init.rc 中 dhcpcd_eth0 守护进程的问题：

改成：

on property:init.svc.dhcpcd_eth0=stopped
start dhcpcd_eth0
service dhcpcd_eth0 /system/bin/dhcpcd -ABKL -f /system/etc/dhcpcd/dhcpcd.conf -d eth0
class main
disabled
oneshot

这样就可以了。

这时init.svc.dhcpcd_eth0 就会是 running 了。这时再点击Setting -> ethernet configuration, DHCP就能正常分配IP了。

libnetutils 和dhcpcd 调用过程如下：

1. libnetutils 调用过程：

jni
=>runDhcp
=>android_net_utils_runDhcp
libs/netutils/dhcp_utils.c
=>dhcp_do_request
=>
static const char DAEMON_NAME[] = "dhcpcd";
static const char DAEMON_PROP_NAME[] = "init.svc.dhcpcd";
static const char DHCP_PROP_NAME_PREFIX[] = "dhcp";
const char *ctrl_prop = "ctl.start";
const char *desired_status = "running";
snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result",
DHCP_PROP_NAME_PREFIX,
interface);
property_set(result_prop_name, "");//设置dhcp.eth0.result="";等到成功完成dhcp之后,
property_set(ctrl_prop, DAEMON_NAME);//向名字为dhcpcd的service,发送"ctrl.start"启动命令字,该service在init.rc中
//init.rc中dhcpcd服务进程命令字
//service dhcpcd /system/bin/dhcpcd eth0
// disabled
// oneshot
wait_for_property(DAEMON_PROP_NAME, desired_status, 10);
//init.c=>init进程
//=>handle_property_set_fd因为是"ctrl.start"命令字,所以调用handle_control_message处理控制信息
//=>handle_control_message
//=>msg_start
//=>
// struct service *svc = service_find_by_name(name);
// service_start(svc);//启动svc,即执行：/system/bin/dhcpcd eth0
//=>service_start
//=>pid = fork();
// if(pid == 0)execve(svc->args[0], (char**) svc->args, (char**) ENV);子进程执行execve运行/system/bin/dhcpcd,参数为eth0
//=>否则父进程,即init进程将
//=>notify_service_state(svc->name, "running");设置该svc的状态prop
// snprintf(pname, sizeof(pname), "init.svc.%s", name);
// property_set(pname, state);//所以这样上面wait_for_property(DAEMON_PROP_NAME, desired_status, 10);也才能够正常pass[luther.gliethttp].
wait_for_property(result_prop_name, NULL, 15);//等待dhcp.eth0.result=非空

2. dhcpcd 调用过程：

system/extra/dhcpcd-4.0.0-beta9/dhcpcd.c
dhcpcd
=>main
# define SYSCONFDIR "/system/etc/dhcpcd"
#define PACKAGE "dhcpcd"
# define CONFIG SYSCONFDIR "/" PACKAGE ".conf"
# define LIBEXECDIR "/system/etc/dhcpcd"
# define SCRIPT LIBEXECDIR "/" PACKAGE "-run-hooks"
=>strlcpy(options->script, SCRIPT, sizeof(options->script));//默认的options->script="/system/etc/dhcpcd /dhcpcd-run-hooks"
=>f = fopen(cf ? cf : CONFIG, "r");//如果没有指定.conf文件,那么使用默认.conf文件
=>parse_config_line//解析"/system/etc/dhcpcd/dhcpcd.conf"默认配置文件
=>parse_option
=>如果在"/system/etc/dhcpcd/dhcpcd.conf"有"script"这个节
=>那么执行strlcpy(options->script, oarg, sizeof(options->script));直接拷贝
/*
{"script", required_argument, NULL, 'c'},
{"option", required_argument, NULL, 'o'},
"/system/etc/dhcpcd/dhcpcd.conf"中的部分内容如下：
...
option domain_name_servers, domain_name, domain_search, host_name
...
*/
=>dhcp_run
=>handle_dhcp_packet
=>handle_dhcp
=>bind_dhcp
reason = "TIMEOUT";reason = "BOUND";reason = "REBIND";reason = "RENEW";
system/extra/dhcpcd-4.0.0-beta9/configure.c
=> configure(iface, reason, state->new, state->old, &state->lease, options, 1);
//如果dhcp超时或者dhcp成功,都会调用exec_script来执行脚本,
//执行setprop dhcp.${interface}.result "failed"或者
//执行setprop dhcp.${interface}.result "ok"
=>exec_script(options, iface->name, reason, NULL, old);
=>然后configure_env通过环境变量将reason传递到脚本中
int exec_script(const struct options *options, const char *iface, const char *reason,
const struct dhcp_message *dhcpn, const struct dhcp_message *dhcpo)
=>pid = fork();
=>if(pid == 0)execve(options->script, argv, env);//子进程执行脚本,默认"/system/etc/dhcpcd/dhcpcd-run-hooks"
//dhcpcd-run-hooks脚本会根据level值,决定是否执行system/etc/dhcpcd/dhcpcd-hook/*目录下的相应文件
//我们的系统在该system/etc/dhcpcd/dhcpcd-hook/*目录下有如下3个文件
//95-configured
//20-dns.conf
//01-test
=>父进程返回while (waitpid(pid, &status, 0) == -1)等待子进程脚本执行完成
system/extra/dhcpcd-4.0.0-beta9/dhcpcd-hooks/20-dns.conf
system/extra/dhcpcd-4.0.0-beta9/dhcpcd-hooks/95-configured
...
setprop dhcp.${interface}.ipaddress "${new_ip_address}"
setprop dhcp.${interface}.result "ok"//设置属性为ok
setprop dhcp.${interface}.result "failed"

dhcpcd 工具

dhcpcd 源代码位于 external/dhcpcd/*

这个目录的源代码生成 /system/bin/dhcpcd 命令工具和一些信息文件。

0605/external/dhcpcd$ ls *
android.conf CleanSpec.mk configure.h dhcpcd.conf            dhcp.h     if-linux.c           logger.c                 NOTICE            ThirdPartyProject.prop
Android.mk    client.c      control.c    dhcpcd.conf.5          duid.c     if-linux-wireless.c logger.h                 platform-bsd.c
arp.c         client.h      control.h    dhcpcd.conf.5.in       duid.h     if-options.c         lpf.c                    platform.h
arp.h         common.c      defs.h       dhcpcd.h               eloop.c    if-options.h         Makefile                 platform-linux.c
bind.c        common.h      dhcp.c       dhcpcd-run-hooks       eloop.h    if-pref.c            Makefile.inc             README
bind.h        config.h      dhcpcd.8     dhcpcd-run-hooks.8     ifaddrs.c if-pref.h            MODULE_LICENSE_BSD_LIKE showlease.c
bpf.c         config.mk     dhcpcd.8.in dhcpcd-run-hooks.8.in ifaddrs.h ipv4ll.c             net.c                    signals.c
bpf-filter.h configure.c   dhcpcd.c     dhcpcd-run-hooks.in    if-bsd.c   ipv4ll.h             net.h                    signals.h

compat:
arc4random.c arc4random.h closefrom.c closefrom.h getline.c getline.h linkaddr.c strlcpy.c strlcpy.h

dhcpcd-hooks:
01-test 10-mtu       20-resolv.conf      30-hostname       50-ntp.conf 50-yp.conf         95-configured
02-dump 20-dns.conf 29-lookup-hostname 50-dhcpcd-compat 50-ypbind    90-NetworkManager Makefile

mk:
cc.mk depend.mk dist.mk files.mk man.mk os-BSD.mk os-Darwin.mk os-Linux.mk os.mk prog.mk scripts.mk sys.mk

这里代码比较多，暂不细究了。