1/*
2 * Copyright (C) 2016 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 com.android.server.wifi.hotspot2;
18
19import android.text.TextUtils;
20
21/**
22 * Unique key for identifying APs that will contain the same ANQP information.
23 *
24 * APs in the same ESS (SSID or HESSID) with the same ANQP domain ID will have the same ANQP
25 * information. Thus, those APs will be keyed by the ESS identifier (SSID or HESSID) and the
26 * ANQP domain ID.
27 *
28 * APs without ANQP domain ID set will assumed to have unique ANQP information. Thus, those
29 * APs will be keyed by SSID and BSSID.
30 */
31public class ANQPNetworkKey {
32    private final String mSSID;
33    private final long mBSSID;
34    private final long mHESSID;
35    private final int mAnqpDomainID;
36
37    public ANQPNetworkKey(String ssid, long bssid, long hessid, int anqpDomainID) {
38        mSSID = ssid;
39        mBSSID = bssid;
40        mHESSID = hessid;
41        mAnqpDomainID = anqpDomainID;
42    }
43
44    /**
45     * Build an ANQP network key suitable for the granularity of the key space as follows:
46     *
47     * HESSID   domainID    Key content       Rationale
48     * -------- ----------- -----------       --------------------
49     * n/a      zero        SSID/BSSID        Domain ID indicates unique AP info
50     * not set  set         SSID/domainID     Standard definition of an ESS
51     * set      set         HESSID/domainID   The ESS is defined by the HESSID
52     *
53     * @param ssid The SSID of the AP
54     * @param bssid The BSSID of the AP
55     * @param hessid The HESSID of the AP
56     * @param anqpDomainId The ANQP Domain ID of the AP
57     * @return {@link ANQPNetworkKey}
58     */
59    public static ANQPNetworkKey buildKey(String ssid, long bssid, long hessid, int anqpDomainId) {
60        if (anqpDomainId == 0) {
61            return new ANQPNetworkKey(ssid, bssid, 0, 0);
62        } else if (hessid != 0L) {
63            return new ANQPNetworkKey(null, 0, hessid, anqpDomainId);
64        }
65        return new ANQPNetworkKey(ssid, 0, 0, anqpDomainId);
66    }
67
68    @Override
69    public int hashCode() {
70        if (mHESSID != 0) {
71            return (int) (((mHESSID >>> 32) * 31 + mHESSID) * 31 + mAnqpDomainID);
72        } else if (mBSSID != 0) {
73            return (int) ((mSSID.hashCode() * 31 + (mBSSID >>> 32)) * 31 + mBSSID);
74        } else {
75            return mSSID.hashCode() * 31 + mAnqpDomainID;
76        }
77    }
78
79    @Override
80    public boolean equals(Object thatObject) {
81        if (thatObject == this) {
82            return true;
83        }
84        if (!(thatObject instanceof ANQPNetworkKey)) {
85            return false;
86        }
87        ANQPNetworkKey that = (ANQPNetworkKey) thatObject;
88        return TextUtils.equals(that.mSSID, mSSID)
89                && that.mBSSID == mBSSID
90                && that.mHESSID == mHESSID
91                && that.mAnqpDomainID == mAnqpDomainID;
92    }
93
94    @Override
95    public String toString() {
96        if (mHESSID != 0L) {
97            return Utils.macToString(mHESSID) + ":" + mAnqpDomainID;
98        } else if (mBSSID != 0L) {
99            return Utils.macToString(mBSSID)
100                    + ":<" + Utils.toUnicodeEscapedString(mSSID) + ">";
101        } else {
102            return "<" + Utils.toUnicodeEscapedString(mSSID) + ">:" + mAnqpDomainID;
103        }
104    }
105}
106