framework: Introduce INetworkManagementService for communicating with netd

This is the framework-exposed interface for the (future) management of
all Android network management functions. Initial support is for providing
tethering.

Updated: Integrate feedback from review; clean up naming

Updated: Switch from add/remove/list to get/set for DNS forwarders
         - allows prioritization / ordering of DNS servers

Updated: Refactor NAT api

Updated: Refactor NAT api (last time sorry)

Signed-off-by: San Mehat <san@google.com>
diff --git a/services/java/com/android/server/NetworkManagementService.java b/services/java/com/android/server/NetworkManagementService.java
new file mode 100644
index 0000000..97fa0cc
--- /dev/null
+++ b/services/java/com/android/server/NetworkManagementService.java
@@ -0,0 +1,303 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import android.app.PendingIntent;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.res.Resources;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.INetworkManagementService;
+import android.os.Handler;
+import android.text.TextUtils;
+import android.util.Log;
+import java.util.ArrayList;
+
+import android.provider.Settings;
+import android.content.ContentResolver;
+import android.database.ContentObserver;
+
+import java.io.File;
+import java.io.FileReader;
+import java.lang.IllegalStateException;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+/**
+ * @hide
+ */
+class NetworkManagementService extends INetworkManagementService.Stub {
+
+    private static final String TAG = "NetworkManagmentService";
+
+    class NetdResponseCode {
+        public static final int InterfaceListResult       = 110;
+        public static final int TetherInterfaceListResult = 111;
+        public static final int TetherDnsFwdTgtListResult = 112;
+
+        public static final int TetherStatusResult        = 210;
+        public static final int IpFwdStatusResult         = 211;
+    }
+
+    /**
+     * Binder context for this service
+     */
+    private Context mContext;
+
+    /**
+     * connector object for communicating with netd
+     */
+    private NativeDaemonConnector mConnector;
+
+    /**
+     * Constructs a new NetworkManagementService instance
+     *
+     * @param context  Binder context for this service
+     */
+    private NetworkManagementService(Context context) {
+        mContext = context;
+
+        mConnector = new NativeDaemonConnector(
+                new NetdCallbackReceiver(), "netd", 10, "NetdConnector");
+        Thread thread = new Thread(mConnector, NativeDaemonConnector.class.getName());
+        thread.start();
+    }
+
+    //
+    // Netd Callback handling
+    //
+
+    class NetdCallbackReceiver implements INativeDaemonConnectorCallbacks {
+        public void onDaemonConnected() {
+            new Thread() {
+                public void run() {
+                    // XXX: Run some tests
+                }
+            }.start();
+        }
+        public boolean onEvent(int code, String raw, String[] cooked) {
+           return false;
+        }
+    }
+
+    //
+    // INetworkManagementService members
+    //
+
+    public String[] listInterfaces() throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        ArrayList<String> rsp = mConnector.doCommand("list_interfaces");
+
+        String[] rdata = new String[rsp.size()];
+        int idx = 0;
+
+        for (String line : rsp) {
+            String []tok = line.split(" ");
+            int code = Integer.parseInt(tok[0]);
+            if (code == NetdResponseCode.InterfaceListResult) {
+                if (tok.length !=2) {
+                    throw new IllegalStateException(
+                            String.format("Malformatted list entry '%s'", line));
+                }
+                rdata[idx++] = tok[1];
+            } else if (code == NativeDaemonConnector.ResponseCode.CommandOkay) {
+                return rdata;
+            } else {
+                throw new IllegalStateException(String.format("Unexpected response code %d", code));
+            }
+        }
+        throw new IllegalStateException("Got an empty response");
+    }
+
+    public void shutdown() {
+        if (mContext.checkCallingOrSelfPermission(
+                android.Manifest.permission.SHUTDOWN)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires SHUTDOWN permission");
+        }
+
+        Log.d(TAG, "Shutting down");
+    }
+
+    public boolean getIpForwardingEnabled() throws IllegalStateException{
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        ArrayList<String> rsp = mConnector.doCommand("ipfwd status");
+
+        for (String line : rsp) {
+            String []tok = line.split(" ");
+            int code = Integer.parseInt(tok[0]);
+            if (code == NetdResponseCode.IpFwdStatusResult) {
+                // 211 Forwarding <enabled/disabled>
+                if (tok.length !=2) {
+                    throw new IllegalStateException(
+                            String.format("Malformatted list entry '%s'", line));
+                }
+                if (tok[2].equals("enabled"))
+                    return true;
+                return false;
+            } else {
+                throw new IllegalStateException(String.format("Unexpected response code %d", code));
+            }
+        }
+        throw new IllegalStateException("Got an empty response");
+    }
+
+    public void setIpForwardingEnabled(boolean enable) throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand(String.format("ipfwd %sable", (enable ? "en" : "dis")));
+    }
+
+    public void startTethering(String dhcpRangeStart, String dhcpRangeEnd)
+             throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand(String.format("tether start %s %s", dhcpRangeStart, dhcpRangeEnd));
+    }
+
+    public void stopTethering() throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand("tether stop");
+    }
+
+    public boolean isTetheringStarted() throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        ArrayList<String> rsp = mConnector.doCommand("tether status");
+
+        for (String line : rsp) {
+            String []tok = line.split(" ");
+            int code = Integer.parseInt(tok[0]);
+            if (code == NetdResponseCode.TetherStatusResult) {
+                // XXX: Tethering services <started/stopped> <TBD>...
+                if (tok[2].equals("started"))
+                    return true;
+                return false;
+            } else {
+                throw new IllegalStateException(String.format("Unexpected response code %d", code));
+            }
+        }
+        throw new IllegalStateException("Got an empty response");
+    }
+
+    public void tetherInterface(String iface) throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand("tether interface add " + iface);
+    }
+
+    public void untetherInterface(String iface) {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand("tether interface remove " + iface);
+    }
+
+    public String[] listTetheredInterfaces() throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        ArrayList<String> rsp = mConnector.doCommand("tether interface list");
+
+        String[] rdata = new String[rsp.size()];
+        int idx = 0;
+
+        for (String line : rsp) {
+            String []tok = line.split(" ");
+            int code = Integer.parseInt(tok[0]);
+            if (code == NetdResponseCode.TetherInterfaceListResult) {
+                if (tok.length !=2) {
+                    throw new IllegalStateException(
+                            String.format("Malformatted list entry '%s'", line));
+                }
+                rdata[idx++] = tok[1];
+            } else if (code == NativeDaemonConnector.ResponseCode.CommandOkay) {
+                return rdata;
+            } else {
+                throw new IllegalStateException(String.format("Unexpected response code %d", code));
+            }
+        }
+        throw new IllegalStateException("Got an empty response");
+    }
+
+    public void setDnsForwarders(String[] dns) throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        try {
+            String cmd = "tether dns set ";
+            for (String s : dns) {
+                cmd += InetAddress.getByName(s).toString() + " ";
+            }
+            mConnector.doCommand(cmd);
+        } catch (UnknownHostException e) {
+            throw new IllegalStateException("Error resolving dns name", e);
+        }
+    }
+
+    public String[] getDnsForwarders() throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        ArrayList<String> rsp = mConnector.doCommand("tether dns list");
+
+        String[] rdata = new String[rsp.size()];
+        int idx = 0;
+
+        for (String line : rsp) {
+            String []tok = line.split(" ");
+            int code = Integer.parseInt(tok[0]);
+            if (code == NetdResponseCode.TetherDnsFwdTgtListResult) {
+                if (tok.length !=2) {
+                    throw new IllegalStateException(
+                            String.format("Malformatted list entry '%s'", line));
+                }
+                rdata[idx++] = tok[1];
+            } else if (code == NativeDaemonConnector.ResponseCode.CommandOkay) {
+                return rdata;
+            } else {
+                throw new IllegalStateException(String.format("Unexpected response code %d", code));
+            }
+        }
+        throw new IllegalStateException("Got an empty response");
+    }
+
+    public void enableNat(String internalInterface, String externalInterface)
+            throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand(
+                String.format("nat enable %s %s", internalInterface, externalInterface));
+    }
+
+    public void disableNat(String internalInterface, String externalInterface)
+            throws IllegalStateException {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.CHANGE_NETWORK_STATE, "NetworkManagementService");
+        mConnector.doCommand(
+                String.format("nat disable %s %s", internalInterface, externalInterface));
+    }
+}
+