001/* 002 * Copyright 2015-2020 the original author or authors 003 * 004 * This software is licensed under the Apache License, Version 2.0, 005 * the GNU Lesser General Public License version 2 or later ("LGPL") 006 * and the WTFPL. 007 * You may choose either license to govern your use of this software only 008 * upon the condition that you accept all of the terms of either 009 * the Apache License 2.0, the LGPL 2.1+ or the WTFPL. 010 */ 011package org.minidns.source; 012 013import org.minidns.DnsCache; 014import org.minidns.MiniDnsFuture; 015import org.minidns.MiniDnsFuture.InternalMiniDnsFuture; 016import org.minidns.dnsmessage.DnsMessage; 017import org.minidns.dnsqueryresult.DnsQueryResult; 018 019import java.io.IOException; 020import java.net.InetAddress; 021 022public abstract class AbstractDnsDataSource implements DnsDataSource { 023 024 @Override 025 public abstract DnsQueryResult query(DnsMessage message, InetAddress address, int port) throws IOException; 026 027 @Override 028 public MiniDnsFuture<DnsQueryResult, IOException> queryAsync(DnsMessage message, InetAddress address, int port, OnResponseCallback onResponseCallback) { 029 InternalMiniDnsFuture<DnsQueryResult, IOException> future = new InternalMiniDnsFuture<>(); 030 DnsQueryResult result; 031 try { 032 result = query(message, address, port); 033 } catch (IOException e) { 034 future.setException(e); 035 return future; 036 } 037 future.setResult(result); 038 return future; 039 } 040 041 protected int udpPayloadSize = 1024; 042 043 /** 044 * DNS timeout. 045 */ 046 protected int timeout = 5000; 047 048 @Override 049 public int getTimeout() { 050 return timeout; 051 } 052 053 @Override 054 public void setTimeout(int timeout) { 055 if (timeout <= 0) { 056 throw new IllegalArgumentException("Timeout must be greater than zero"); 057 } 058 this.timeout = timeout; 059 } 060 061 @Override 062 public int getUdpPayloadSize() { 063 return udpPayloadSize; 064 } 065 066 public void setUdpPayloadSize(int udpPayloadSize) { 067 if (udpPayloadSize <= 0) { 068 throw new IllegalArgumentException("UDP payload size must be greater than zero"); 069 } 070 this.udpPayloadSize = udpPayloadSize; 071 } 072 073 private DnsCache cache; 074 075 protected final void cacheResult(DnsMessage request, DnsQueryResult response) { 076 final DnsCache activeCache = cache; 077 if (activeCache == null) { 078 return; 079 } 080 activeCache.put(request, response); 081 } 082 083 public enum QueryMode { 084 /** 085 * Perform the query mode that is assumed "best" for that particular case. 086 */ 087 dontCare, 088 089 /** 090 * Try UDP first, and if the result is bigger than the maximum UDP payload size, or if something else goes wrong, fallback to TCP. 091 */ 092 udpTcp, 093 094 /** 095 * Always use only TCP when querying DNS servers. 096 */ 097 tcp, 098 } 099 100 private QueryMode queryMode = QueryMode.dontCare; 101 102 public void setQueryMode(QueryMode queryMode) { 103 if (queryMode == null) { 104 throw new IllegalArgumentException(); 105 } 106 this.queryMode = queryMode; 107 } 108 109 public QueryMode getQueryMode() { 110 return queryMode; 111 } 112 113}