1 /*
2  * Copyright (C) 2014 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 
17 package android.net;
18 
19 import static android.os.UserHandle.PER_USER_RANGE;
20 
21 import android.os.Parcel;
22 import android.os.Parcelable;
23 
24 import java.util.Collection;
25 
26 /**
27  * An inclusive range of UIDs.
28  *
29  * @hide
30  */
31 public final class UidRange implements Parcelable {
32     public final int start;
33     public final int stop;
34 
UidRange(int startUid, int stopUid)35     public UidRange(int startUid, int stopUid) {
36         if (startUid < 0) throw new IllegalArgumentException("Invalid start UID.");
37         if (stopUid < 0) throw new IllegalArgumentException("Invalid stop UID.");
38         if (startUid > stopUid) throw new IllegalArgumentException("Invalid UID range.");
39         start = startUid;
40         stop  = stopUid;
41     }
42 
createForUser(int userId)43     public static UidRange createForUser(int userId) {
44         return new UidRange(userId * PER_USER_RANGE, (userId + 1) * PER_USER_RANGE - 1);
45     }
46 
47     /** Returns the smallest user Id which is contained in this UidRange */
getStartUser()48     public int getStartUser() {
49         return start / PER_USER_RANGE;
50     }
51 
52     /** Returns the largest user Id which is contained in this UidRange */
getEndUser()53     public int getEndUser() {
54         return stop / PER_USER_RANGE;
55     }
56 
contains(int uid)57     public boolean contains(int uid) {
58         return start <= uid && uid <= stop;
59     }
60 
61     /**
62      * Returns the count of UIDs in this range.
63      */
count()64     public int count() {
65         return 1 + stop - start;
66     }
67 
68     /**
69      * @return {@code true} if this range contains every UID contained by the {@param other} range.
70      */
containsRange(UidRange other)71     public boolean containsRange(UidRange other) {
72         return start <= other.start && other.stop <= stop;
73     }
74 
75     @Override
hashCode()76     public int hashCode() {
77         int result = 17;
78         result = 31 * result + start;
79         result = 31 * result + stop;
80         return result;
81     }
82 
83     @Override
equals(Object o)84     public boolean equals(Object o) {
85         if (this == o) {
86             return true;
87         }
88         if (o instanceof UidRange) {
89             UidRange other = (UidRange) o;
90             return start == other.start && stop == other.stop;
91         }
92         return false;
93     }
94 
95     @Override
toString()96     public String toString() {
97         return start + "-" + stop;
98     }
99 
100     // Implement the Parcelable interface
101     // TODO: Consider making this class no longer parcelable, since all users are likely in the
102     // system server.
103     @Override
describeContents()104     public int describeContents() {
105         return 0;
106     }
107 
108     @Override
writeToParcel(Parcel dest, int flags)109     public void writeToParcel(Parcel dest, int flags) {
110         dest.writeInt(start);
111         dest.writeInt(stop);
112     }
113 
114     public static final @android.annotation.NonNull Creator<UidRange> CREATOR =
115         new Creator<UidRange>() {
116             @Override
117             public UidRange createFromParcel(Parcel in) {
118                 int start = in.readInt();
119                 int stop = in.readInt();
120 
121                 return new UidRange(start, stop);
122             }
123             @Override
124             public UidRange[] newArray(int size) {
125                 return new UidRange[size];
126             }
127     };
128 
129     /**
130      * Returns whether any of the UidRange in the collection contains the specified uid
131      *
132      * @param ranges The collection of UidRange to check
133      * @param uid the uid in question
134      * @return {@code true} if the uid is contained within the ranges, {@code false} otherwise
135      *
136      * @see UidRange#contains(int)
137      */
containsUid(Collection<UidRange> ranges, int uid)138     public static boolean containsUid(Collection<UidRange> ranges, int uid) {
139         if (ranges == null) return false;
140         for (UidRange range : ranges) {
141             if (range.contains(uid)) {
142                 return true;
143             }
144         }
145         return false;
146     }
147 }
148