001/**
002 *
003 * Copyright 2013-2018 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.util.dns;
018
019import java.net.InetAddress;
020import java.util.List;
021
022import org.jivesoftware.smack.util.StringUtils;
023
024import org.minidns.dnsname.DnsName;
025
026/**
027 * A DNS SRV RR.
028 *
029 * @see <a href="http://tools.ietf.org/html/rfc2782">RFC 2782: A DNS RR for specifying the location of services (DNS
030 * SRV)</a>
031 * @author Florian Schmaus
032 *
033 */
034public class SRVRecord extends HostAddress implements Comparable<SRVRecord> {
035
036    private int weight;
037    private int priority;
038
039    /**
040     * SRV Record constructor.
041     *
042     * @param fqdn Fully qualified domain name
043     * @param port The connection port
044     * @param priority Priority of the target host
045     * @param weight Relative weight for records with same priority
046     * @param inetAddresses list of addresses.
047     * @throws IllegalArgumentException fqdn is null or any other field is not in valid range (0-65535).
048     */
049    public SRVRecord(DnsName fqdn, int port, int priority, int weight, List<InetAddress> inetAddresses) {
050        super(fqdn, port, inetAddresses);
051        StringUtils.requireNotNullOrEmpty(fqdn, "The FQDN must not be null");
052        if (weight < 0 || weight > 65535)
053            throw new IllegalArgumentException(
054                    "DNS SRV records weight must be a 16-bit unsigned integer (i.e. between 0-65535. Weight was: "
055                            + weight);
056
057        if (priority < 0 || priority > 65535)
058            throw new IllegalArgumentException(
059                    "DNS SRV records priority must be a 16-bit unsigned integer (i.e. between 0-65535. Priority was: "
060                            + priority);
061
062        this.priority = priority;
063        this.weight = weight;
064
065    }
066
067    public int getPriority() {
068        return priority;
069    }
070
071    public int getWeight() {
072        return weight;
073    }
074
075    @Override
076    public int compareTo(SRVRecord other) {
077        // According to RFC2782,
078        // "[a] client MUST attempt to contact the target host with the lowest-numbered priority it can reach".
079        // This means that a SRV record with a higher priority is 'less' then one with a lower.
080        int res = other.priority - this.priority;
081        if (res == 0) {
082            res = this.weight - other.weight;
083        }
084        return res;
085    }
086
087    @Override
088    public String toString() {
089        return super.toString() + " prio:" + priority + ":w:" + weight;
090    }
091}