| /* |
| * Copyright (C) 2012 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 android.net.wifi.p2p.nsd; |
| |
| import android.annotation.UnsupportedAppUsage; |
| import android.net.nsd.DnsSdTxtRecord; |
| import android.text.TextUtils; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Locale; |
| import java.util.Map; |
| |
| /** |
| * A class for storing Bonjour service information that is advertised |
| * over a Wi-Fi peer-to-peer setup. |
| * |
| * {@see android.net.wifi.p2p.WifiP2pManager#addLocalService} |
| * {@see android.net.wifi.p2p.WifiP2pManager#removeLocalService} |
| * {@see WifiP2pServiceInfo} |
| * {@see WifiP2pUpnpServiceInfo} |
| */ |
| public class WifiP2pDnsSdServiceInfo extends WifiP2pServiceInfo { |
| |
| /** |
| * Bonjour version 1. |
| * @hide |
| */ |
| public static final int VERSION_1 = 0x01; |
| |
| /** |
| * Pointer record. |
| * @hide |
| */ |
| public static final int DNS_TYPE_PTR = 12; |
| |
| /** |
| * Text record. |
| * @hide |
| */ |
| public static final int DNS_TYPE_TXT = 16; |
| |
| /** |
| * virtual memory packet. |
| * see E.3 of the Wi-Fi Direct technical specification for the detail.<br> |
| * Key: domain name Value: pointer address.<br> |
| */ |
| private final static Map<String, String> sVmPacket; |
| |
| static { |
| sVmPacket = new HashMap<String, String>(); |
| sVmPacket.put("_tcp.local.", "c00c"); |
| sVmPacket.put("local.", "c011"); |
| sVmPacket.put("_udp.local.", "c01c"); |
| } |
| |
| /** |
| * This constructor is only used in newInstance(). |
| * |
| * @param queryList |
| */ |
| private WifiP2pDnsSdServiceInfo(List<String> queryList) { |
| super(queryList); |
| } |
| |
| /** |
| * Create a Bonjour service information object. |
| * |
| * @param instanceName instance name.<br> |
| * e.g) "MyPrinter" |
| * @param serviceType service type.<br> |
| * e.g) "_ipp._tcp" |
| * @param txtMap TXT record with key/value pair in a map confirming to format defined at |
| * http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt |
| * @return Bonjour service information object |
| */ |
| public static WifiP2pDnsSdServiceInfo newInstance(String instanceName, |
| String serviceType, Map<String, String> txtMap) { |
| if (TextUtils.isEmpty(instanceName) || TextUtils.isEmpty(serviceType)) { |
| throw new IllegalArgumentException( |
| "instance name or service type cannot be empty"); |
| } |
| |
| DnsSdTxtRecord txtRecord = new DnsSdTxtRecord(); |
| if (txtMap != null) { |
| for (String key : txtMap.keySet()) { |
| txtRecord.set(key, txtMap.get(key)); |
| } |
| } |
| |
| ArrayList<String> queries = new ArrayList<String>(); |
| queries.add(createPtrServiceQuery(instanceName, serviceType)); |
| queries.add(createTxtServiceQuery(instanceName, serviceType, txtRecord)); |
| |
| return new WifiP2pDnsSdServiceInfo(queries); |
| } |
| |
| /** |
| * Create wpa_supplicant service query for PTR record. |
| * |
| * @param instanceName instance name.<br> |
| * e.g) "MyPrinter" |
| * @param serviceType service type.<br> |
| * e.g) "_ipp._tcp" |
| * @return wpa_supplicant service query. |
| */ |
| private static String createPtrServiceQuery(String instanceName, |
| String serviceType) { |
| |
| StringBuffer sb = new StringBuffer(); |
| sb.append("bonjour "); |
| sb.append(createRequest(serviceType + ".local.", DNS_TYPE_PTR, VERSION_1)); |
| sb.append(" "); |
| |
| byte[] data = instanceName.getBytes(); |
| sb.append(String.format(Locale.US, "%02x", data.length)); |
| sb.append(WifiP2pServiceInfo.bin2HexStr(data)); |
| // This is the start point of this response. |
| // Therefore, it indicates the request domain name. |
| sb.append("c027"); |
| return sb.toString(); |
| } |
| |
| /** |
| * Create wpa_supplicant service query for TXT record. |
| * |
| * @param instanceName instance name.<br> |
| * e.g) "MyPrinter" |
| * @param serviceType service type.<br> |
| * e.g) "_ipp._tcp" |
| * @param txtRecord TXT record.<br> |
| * @return wpa_supplicant service query. |
| */ |
| private static String createTxtServiceQuery(String instanceName, |
| String serviceType, |
| DnsSdTxtRecord txtRecord) { |
| |
| |
| StringBuffer sb = new StringBuffer(); |
| sb.append("bonjour "); |
| |
| sb.append(createRequest((instanceName + "." + serviceType + ".local."), |
| DNS_TYPE_TXT, VERSION_1)); |
| sb.append(" "); |
| byte[] rawData = txtRecord.getRawData(); |
| if (rawData.length == 0) { |
| sb.append("00"); |
| } else { |
| sb.append(bin2HexStr(rawData)); |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * Create bonjour service discovery request. |
| * |
| * @param dnsName dns name |
| * @param dnsType dns type |
| * @param version version number |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| static String createRequest(String dnsName, int dnsType, int version) { |
| StringBuffer sb = new StringBuffer(); |
| |
| /* |
| * The request format is as follows. |
| * ________________________________________________ |
| * | Encoded and Compressed dns name (variable) | |
| * ________________________________________________ |
| * | Type (2) | Version (1) | |
| */ |
| if (dnsType == WifiP2pDnsSdServiceInfo.DNS_TYPE_TXT) { |
| dnsName = dnsName.toLowerCase(Locale.ROOT); // TODO: is this right? |
| } |
| sb.append(compressDnsName(dnsName)); |
| sb.append(String.format(Locale.US, "%04x", dnsType)); |
| sb.append(String.format(Locale.US, "%02x", version)); |
| |
| return sb.toString(); |
| } |
| |
| /** |
| * Compress DNS data. |
| * |
| * see E.3 of the Wi-Fi Direct technical specification for the detail. |
| * |
| * @param dnsName dns name |
| * @return compressed dns name |
| */ |
| private static String compressDnsName(String dnsName) { |
| StringBuffer sb = new StringBuffer(); |
| |
| // The domain name is replaced with a pointer to a prior |
| // occurrence of the same name in virtual memory packet. |
| while (true) { |
| String data = sVmPacket.get(dnsName); |
| if (data != null) { |
| sb.append(data); |
| break; |
| } |
| int i = dnsName.indexOf('.'); |
| if (i == -1) { |
| if (dnsName.length() > 0) { |
| sb.append(String.format(Locale.US, "%02x", dnsName.length())); |
| sb.append(WifiP2pServiceInfo.bin2HexStr(dnsName.getBytes())); |
| } |
| // for a sequence of labels ending in a zero octet |
| sb.append("00"); |
| break; |
| } |
| |
| String name = dnsName.substring(0, i); |
| dnsName = dnsName.substring(i + 1); |
| sb.append(String.format(Locale.US, "%02x", name.length())); |
| sb.append(WifiP2pServiceInfo.bin2HexStr(name.getBytes())); |
| } |
| return sb.toString(); |
| } |
| } |