am 4e4d59ee: Connect the DHCP UDP socket to the server.

* commit '4e4d59eeef86fa8560d35c00168869b0a066f962':
  Connect the DHCP UDP socket to the server.

core/java/android/net/DhcpResults.java

@@ -21,7 +21,6 @@ import android.os.Parcel;
 import android.text.TextUtils;
 import android.util.Log;
 
-import java.net.InetAddress;
 import java.net.Inet4Address;
 import java.util.Objects;
 
@@ -34,7 +33,7 @@ import java.util.Objects;
 public class DhcpResults extends StaticIpConfiguration {
     private static final String TAG = "DhcpResults";
 
-    public InetAddress serverAddress;
+    public Inet4Address serverAddress;
 
     /** Vendor specific information (from RFC 2132). */
     public String vendorInfo;
@@ -142,7 +141,7 @@ public class DhcpResults extends StaticIpConfiguration {
     private static void readFromParcel(DhcpResults dhcpResults, Parcel in) {
         StaticIpConfiguration.readFromParcel(dhcpResults, in);
         dhcpResults.leaseDuration = in.readInt();
-        dhcpResults.serverAddress = NetworkUtils.unparcelInetAddress(in);
+        dhcpResults.serverAddress = (Inet4Address) NetworkUtils.unparcelInetAddress(in);
         dhcpResults.vendorInfo = in.readString();
     }
 
@@ -183,8 +182,8 @@ public class DhcpResults extends StaticIpConfiguration {
 
     public boolean setServerAddress(String addrString) {
         try {
-            serverAddress = NetworkUtils.numericToInetAddress(addrString);
+            serverAddress = (Inet4Address) NetworkUtils.numericToInetAddress(addrString);
-        } catch (IllegalArgumentException e) {
+        } catch (IllegalArgumentException|ClassCastException e) {
             Log.e(TAG, "setServerAddress failed with addrString " + addrString);
             return true;
         }

services/net/java/android/net/dhcp/DhcpClient.java

@@ -299,6 +299,7 @@ public class DhcpClient extends BaseDhcpStateMachine {
             Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_REUSEADDR, 1);
             Os.setsockoptIfreq(mUdpSock, SOL_SOCKET, SO_BINDTODEVICE, mIfaceName);
             Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_BROADCAST, 1);
+            Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_RCVBUF, 0);
             Os.bind(mUdpSock, Inet4Address.ANY, DhcpPacket.DHCP_CLIENT);
             NetworkUtils.protectFromVpn(mUdpSock);
         } catch(SocketException|ErrnoException e) {
@@ -308,6 +309,16 @@ public class DhcpClient extends BaseDhcpStateMachine {
         return true;
     }
 
+    private boolean connectUdpSock(Inet4Address to) {
+        try {
+            Os.connect(mUdpSock, to, DhcpPacket.DHCP_SERVER);
+            return true;
+        } catch (SocketException|ErrnoException e) {
+            Log.e(TAG, "Error connecting UDP socket", e);
+            return false;
+        }
+    }
+
     private static void closeQuietly(FileDescriptor fd) {
         try {
             IoBridge.closeAndSignalBlockedThreads(fd);
@@ -325,7 +336,7 @@ public class DhcpClient extends BaseDhcpStateMachine {
         try {
             mNMService.setInterfaceConfig(mIfaceName, ifcg);
         } catch (RemoteException|IllegalStateException e) {
-            Log.e(TAG, "Error configuring IP address : " + e);
+            Log.e(TAG, "Error configuring IP address " + address + ": ", e);
             return false;
         }
         return true;
@@ -377,8 +388,10 @@ public class DhcpClient extends BaseDhcpStateMachine {
                 maybeLog("Broadcasting " + description);
                 Os.sendto(mPacketSock, buf.array(), 0, buf.limit(), 0, mInterfaceBroadcastAddr);
             } else {
-                maybeLog("Unicasting " + description + " to " + to.getHostAddress());
+                // It's safe to call getpeername here, because we only send unicast packets if we
-                Os.sendto(mUdpSock, buf, 0, to, DhcpPacket.DHCP_SERVER);
+                // have an IP address, and we connect the UDP socket in DhcpHaveAddressState#enter.
+                maybeLog("Unicasting " + description + " to " + Os.getpeername(mUdpSock));
+                Os.write(mUdpSock, buf);
             }
         } catch(ErrnoException|IOException e) {
             Log.e(TAG, "Can't send packet: ", e);
@@ -790,6 +803,7 @@ public class DhcpClient extends BaseDhcpStateMachine {
                     transitionTo(mDhcpBoundState);
                 }
             } else if (packet instanceof DhcpNakPacket) {
+                // TODO: Wait a while before returning into INIT state.
                 Log.d(TAG, "Received NAK, returning to INIT");
                 mOffer = null;
                 transitionTo(mDhcpInitState);
@@ -807,10 +821,8 @@ public class DhcpClient extends BaseDhcpStateMachine {
         @Override
         public void enter() {
             super.enter();
-            if (setIpAddress(mDhcpLease.ipAddress)) {
+            if (!setIpAddress(mDhcpLease.ipAddress) ||
-                maybeLog("Configured IP address " + mDhcpLease.ipAddress);
+                    !connectUdpSock((mDhcpLease.serverAddress))) {
-            } else {
-                Log.e(TAG, "Failed to configure IP address " + mDhcpLease.ipAddress);
                 notifyFailure();
                 // There's likely no point in going into DhcpInitState here, we'll probably just
                 // repeat the transaction, get the same IP address as before, and fail.