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NetlinkTracker.javaAPI DocAndroid 5.1 API14419Thu Mar 12 22:22:10 GMT 2015com.android.server.net

NetlinkTracker

public class NetlinkTracker extends BaseNetworkObserver
Keeps track of link configuration received from Netlink. Instances of this class are expected to be owned by subsystems such as Wi-Fi or Ethernet that manage one or more network interfaces. Each interface to be tracked needs its own {@code NetlinkTracker}. An instance of this class is constructed by passing in an interface name and a callback. The owner is then responsible for registering the tracker with NetworkManagementService. When the class receives update notifications from the NetworkManagementService notification threads, it applies the update to its local LinkProperties, and if something has changed, notifies its owner of the update via the callback. The owner can then call {@code getLinkProperties()} in order to find out what changed. If in the meantime the LinkProperties stored here have changed, this class will return the current LinkProperties. Because each change triggers an update callback after the change is made, the owner may get more callbacks than strictly necessary (some of which may be no-ops), but will not be out of sync once all callbacks have been processed. Threading model: - The owner of this class is expected to create it, register it, and call getLinkProperties or clearLinkProperties on its thread. - Most of the methods in the class are inherited from BaseNetworkObserver and are called by NetworkManagementService notification threads. - All accesses to mLinkProperties must be synchronized(this). All the other member variables are immutable once the object is constructed. This class currently tracks IPv4 and IPv6 addresses. In the future it will track routes and DNS servers.
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Fields Summary
private final String
TAG
private final String
mInterfaceName
private final Callback
mCallback
private final android.net.LinkProperties
mLinkProperties
private DnsServerRepository
mDnsServerRepository
private static final boolean
DBG
Constructors Summary
public NetlinkTracker(String iface, Callback callback)


         
        TAG = "NetlinkTracker/" + iface;
        mInterfaceName = iface;
        mCallback = callback;
        mLinkProperties = new LinkProperties();
        mLinkProperties.setInterfaceName(mInterfaceName);
        mDnsServerRepository = new DnsServerRepository();
Methods Summary
public voidaddressRemoved(java.lang.String iface, android.net.LinkAddress address)

        if (mInterfaceName.equals(iface)) {
            maybeLog("addressRemoved", iface, address);
            boolean changed;
            synchronized (this) {
                changed = mLinkProperties.removeLinkAddress(address);
            }
            if (changed) {
                mCallback.update();
            }
        }
public voidaddressUpdated(java.lang.String iface, android.net.LinkAddress address)

        if (mInterfaceName.equals(iface)) {
            maybeLog("addressUpdated", iface, address);
            boolean changed;
            synchronized (this) {
                changed = mLinkProperties.addLinkAddress(address);
            }
            if (changed) {
                mCallback.update();
            }
        }
public synchronized voidclearLinkProperties()

        // Clear the repository before clearing mLinkProperties. That way, if a clear() happens
        // while interfaceDnsServerInfo() is being called, we'll end up with no DNS servers in
        // mLinkProperties, as desired.
        mDnsServerRepository = new DnsServerRepository();
        mLinkProperties.clear();
        mLinkProperties.setInterfaceName(mInterfaceName);
public synchronized android.net.LinkPropertiesgetLinkProperties()
Returns a copy of this object's LinkProperties.

        return new LinkProperties(mLinkProperties);
public voidinterfaceDnsServerInfo(java.lang.String iface, long lifetime, java.lang.String[] addresses)

        if (mInterfaceName.equals(iface)) {
            maybeLog("interfaceDnsServerInfo", Arrays.toString(addresses));
            boolean changed = mDnsServerRepository.addServers(lifetime, addresses);
            if (changed) {
                synchronized (this) {
                    mDnsServerRepository.setDnsServersOn(mLinkProperties);
                }
                mCallback.update();
            }
        }
private voidmaybeLog(java.lang.String operation, java.lang.String iface, android.net.LinkAddress address)

        if (DBG) {
            Log.d(TAG, operation + ": " + address + " on " + iface +
                    " flags " + address.getFlags() + " scope " + address.getScope());
        }
private voidmaybeLog(java.lang.String operation, java.lang.Object o)

        if (DBG) {
            Log.d(TAG, operation + ": " + o.toString());
        }
public voidrouteRemoved(android.net.RouteInfo route)

        if (mInterfaceName.equals(route.getInterface())) {
            maybeLog("routeRemoved", route);
            boolean changed;
            synchronized (this) {
                changed = mLinkProperties.removeRoute(route);
            }
            if (changed) {
                mCallback.update();
            }
        }
public voidrouteUpdated(android.net.RouteInfo route)

        if (mInterfaceName.equals(route.getInterface())) {
            maybeLog("routeUpdated", route);
            boolean changed;
            synchronized (this) {
                changed = mLinkProperties.addRoute(route);
            }
            if (changed) {
                mCallback.update();
            }
        }