Copyright (c) 2013, 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.
/**
 * Copyright (c) 2013, 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.pacprocessor;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.os.Process;
import android.os.RemoteException;
import android.util.Log;

import com.android.net.IProxyService;

import java.net.MalformedURLException;
import java.net.URL;

public class PacService extends Service {
    private static final String TAG = "PacService";

    private PacNative mPacNative;
    private ProxyServiceStub mStub;

    @Override
    public void onCreate() {
        super.onCreate();
        if (mPacNative == null) {
            mPacNative = new PacNative();
            mStub = new ProxyServiceStub(mPacNative);
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mPacNative != null) {
            mPacNative.stopPacSupport();
            mPacNative = null;
            mStub = null;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        if (mPacNative == null) {
            mPacNative = new PacNative();
            mStub = new ProxyServiceStub(mPacNative);
        }
        return mStub;
    }

    private static class ProxyServiceStub extends IProxyService.Stub {
        private final PacNative mPacNative;

        public ProxyServiceStub(PacNative pacNative) {
            mPacNative = pacNative;
        }

        @Override
        public String resolvePacFile(String host, String url) throws RemoteException {
            try {
                if (host == null) {
                    throw new IllegalArgumentException("The host must not be null");
                }
                if (url == null) {
                    throw new IllegalArgumentException("The URL must not be null");
                }
                // Check for characters that could be used for an injection attack.
                new URL(url);
                for (char c : host.toCharArray()) {
                    if (!Character.isLetterOrDigit(c) && (c != '.') && (c != '-')) {
                        throw new IllegalArgumentException("Invalid host was passed");
                    }
                }
                return mPacNative.makeProxyRequest(url, host);
            } catch (MalformedURLException e) {
                throw new IllegalArgumentException("Invalid URL was passed");
            }
        }

        @Override
        public void setPacFile(String script) throws RemoteException {
            if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                Log.e(TAG, "Only system user is allowed to call setPacFile");
                throw new SecurityException();
            }
            mPacNative.setCurrentProxyScript(script);
        }

        @Override
        public void startPacSystem() throws RemoteException {
            if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                Log.e(TAG, "Only system user is allowed to call startPacSystem");
                throw new SecurityException();
            }
            mPacNative.startPacSupport();
        }

        @Override
        public void stopPacSystem() throws RemoteException {
            if (Binder.getCallingUid() != Process.SYSTEM_UID) {
                Log.e(TAG, "Only system user is allowed to call stopPacSystem");
                throw new SecurityException();
            }
            mPacNative.stopPacSupport();
        }
    }
}