NetworkPolicyManager.java revision 8fc27e8b87bd1def854a03d84009143b315d4176 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.net;
18
19import static android.content.pm.PackageManager.GET_SIGNATURES;
20import static android.net.NetworkPolicy.CYCLE_NONE;
21import static android.text.format.Time.MONTH_DAY;
22
23import android.content.Context;
24import android.content.Intent;
25import android.content.pm.PackageManager;
26import android.content.pm.PackageManager.NameNotFoundException;
27import android.content.pm.Signature;
28import android.os.RemoteException;
29import android.text.format.Time;
30
31import com.google.android.collect.Sets;
32
33import java.io.PrintWriter;
34import java.util.HashSet;
35
36/**
37 * Manager for creating and modifying network policy rules.
38 *
39 * {@hide}
40 */
41public class NetworkPolicyManager {
42
43    /** No specific network policy, use system default. */
44    public static final int POLICY_NONE = 0x0;
45    /** Reject network usage on metered networks when application in background. */
46    public static final int POLICY_REJECT_METERED_BACKGROUND = 0x1;
47
48    /** All network traffic should be allowed. */
49    public static final int RULE_ALLOW_ALL = 0x0;
50    /** Reject traffic on metered networks. */
51    public static final int RULE_REJECT_METERED = 0x1;
52
53    private static final boolean ALLOW_PLATFORM_APP_POLICY = true;
54
55    /**
56     * {@link Intent} extra that indicates which {@link NetworkTemplate} rule it
57     * applies to.
58     */
59    public static final String EXTRA_NETWORK_TEMPLATE = "android.net.NETWORK_TEMPLATE";
60
61    private INetworkPolicyManager mService;
62
63    public NetworkPolicyManager(INetworkPolicyManager service) {
64        if (service == null) {
65            throw new IllegalArgumentException("missing INetworkPolicyManager");
66        }
67        mService = service;
68    }
69
70    public static NetworkPolicyManager from(Context context) {
71        return (NetworkPolicyManager) context.getSystemService(Context.NETWORK_POLICY_SERVICE);
72    }
73
74    /**
75     * Set policy flags for specific application.
76     *
77     * @param policy {@link #POLICY_NONE} or combination of flags like
78     *            {@link #POLICY_REJECT_METERED_BACKGROUND}.
79     */
80    public void setAppPolicy(int appId, int policy) {
81        try {
82            mService.setAppPolicy(appId, policy);
83        } catch (RemoteException e) {
84        }
85    }
86
87    public int getAppPolicy(int appId) {
88        try {
89            return mService.getAppPolicy(appId);
90        } catch (RemoteException e) {
91            return POLICY_NONE;
92        }
93    }
94
95    public void registerListener(INetworkPolicyListener listener) {
96        try {
97            mService.registerListener(listener);
98        } catch (RemoteException e) {
99        }
100    }
101
102    public void unregisterListener(INetworkPolicyListener listener) {
103        try {
104            mService.unregisterListener(listener);
105        } catch (RemoteException e) {
106        }
107    }
108
109    public void setNetworkPolicies(NetworkPolicy[] policies) {
110        try {
111            mService.setNetworkPolicies(policies);
112        } catch (RemoteException e) {
113        }
114    }
115
116    public NetworkPolicy[] getNetworkPolicies() {
117        try {
118            return mService.getNetworkPolicies();
119        } catch (RemoteException e) {
120            return null;
121        }
122    }
123
124    public void setRestrictBackground(boolean restrictBackground) {
125        try {
126            mService.setRestrictBackground(restrictBackground);
127        } catch (RemoteException e) {
128        }
129    }
130
131    public boolean getRestrictBackground() {
132        try {
133            return mService.getRestrictBackground();
134        } catch (RemoteException e) {
135            return false;
136        }
137    }
138
139    /**
140     * Compute the last cycle boundary for the given {@link NetworkPolicy}. For
141     * example, if cycle day is 20th, and today is June 15th, it will return May
142     * 20th. When cycle day doesn't exist in current month, it snaps to the 1st
143     * of following month.
144     *
145     * @hide
146     */
147    public static long computeLastCycleBoundary(long currentTime, NetworkPolicy policy) {
148        if (policy.cycleDay == CYCLE_NONE) {
149            throw new IllegalArgumentException("Unable to compute boundary without cycleDay");
150        }
151
152        final Time now = new Time(policy.cycleTimezone);
153        now.set(currentTime);
154
155        // first, find cycle boundary for current month
156        final Time cycle = new Time(now);
157        cycle.hour = cycle.minute = cycle.second = 0;
158        snapToCycleDay(cycle, policy.cycleDay);
159
160        if (Time.compare(cycle, now) >= 0) {
161            // cycle boundary is beyond now, use last cycle boundary; start by
162            // pushing ourselves squarely into last month.
163            final Time lastMonth = new Time(now);
164            lastMonth.hour = lastMonth.minute = lastMonth.second = 0;
165            lastMonth.monthDay = 1;
166            lastMonth.month -= 1;
167            lastMonth.normalize(true);
168
169            cycle.set(lastMonth);
170            snapToCycleDay(cycle, policy.cycleDay);
171        }
172
173        return cycle.toMillis(true);
174    }
175
176    /** {@hide} */
177    public static long computeNextCycleBoundary(long currentTime, NetworkPolicy policy) {
178        if (policy.cycleDay == CYCLE_NONE) {
179            throw new IllegalArgumentException("Unable to compute boundary without cycleDay");
180        }
181
182        final Time now = new Time(policy.cycleTimezone);
183        now.set(currentTime);
184
185        // first, find cycle boundary for current month
186        final Time cycle = new Time(now);
187        cycle.hour = cycle.minute = cycle.second = 0;
188        snapToCycleDay(cycle, policy.cycleDay);
189
190        if (Time.compare(cycle, now) <= 0) {
191            // cycle boundary is before now, use next cycle boundary; start by
192            // pushing ourselves squarely into next month.
193            final Time nextMonth = new Time(now);
194            nextMonth.hour = nextMonth.minute = nextMonth.second = 0;
195            nextMonth.monthDay = 1;
196            nextMonth.month += 1;
197            nextMonth.normalize(true);
198
199            cycle.set(nextMonth);
200            snapToCycleDay(cycle, policy.cycleDay);
201        }
202
203        return cycle.toMillis(true);
204    }
205
206    /**
207     * Snap to the cycle day for the current month given; when cycle day doesn't
208     * exist, it snaps to last second of current month.
209     *
210     * @hide
211     */
212    public static void snapToCycleDay(Time time, int cycleDay) {
213        if (cycleDay > time.getActualMaximum(MONTH_DAY)) {
214            // cycle day isn't valid this month; snap to last second of month
215            time.month += 1;
216            time.monthDay = 1;
217            time.second = -1;
218        } else {
219            time.monthDay = cycleDay;
220        }
221        time.normalize(true);
222    }
223
224    /**
225     * Check if given UID can have a {@link #setUidPolicy(int, int)} defined,
226     * usually to protect critical system services.
227     */
228    @Deprecated
229    public static boolean isUidValidForPolicy(Context context, int uid) {
230        // first, quick-reject non-applications
231        if (uid < android.os.Process.FIRST_APPLICATION_UID
232                || uid > android.os.Process.LAST_APPLICATION_UID) {
233            return false;
234        }
235
236        if (!ALLOW_PLATFORM_APP_POLICY) {
237            final PackageManager pm = context.getPackageManager();
238            final HashSet<Signature> systemSignature;
239            try {
240                systemSignature = Sets.newHashSet(
241                        pm.getPackageInfo("android", GET_SIGNATURES).signatures);
242            } catch (NameNotFoundException e) {
243                throw new RuntimeException("problem finding system signature", e);
244            }
245
246            try {
247                // reject apps signed with platform cert
248                for (String packageName : pm.getPackagesForUid(uid)) {
249                    final HashSet<Signature> packageSignature = Sets.newHashSet(
250                            pm.getPackageInfo(packageName, GET_SIGNATURES).signatures);
251                    if (packageSignature.containsAll(systemSignature)) {
252                        return false;
253                    }
254                }
255            } catch (NameNotFoundException e) {
256            }
257        }
258
259        // nothing found above; we can apply policy to UID
260        return true;
261    }
262
263    /** {@hide} */
264    public static void dumpPolicy(PrintWriter fout, int policy) {
265        fout.write("[");
266        if ((policy & POLICY_REJECT_METERED_BACKGROUND) != 0) {
267            fout.write("REJECT_METERED_BACKGROUND");
268        }
269        fout.write("]");
270    }
271
272    /** {@hide} */
273    public static void dumpRules(PrintWriter fout, int rules) {
274        fout.write("[");
275        if ((rules & RULE_REJECT_METERED) != 0) {
276            fout.write("REJECT_METERED");
277        }
278        fout.write("]");
279    }
280
281}
282