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jitsi/src/net/java/sip/communicator/util/NetworkUtils.java

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38 KiB

/*
* SIP Communicator, the OpenSource Java VoIP and Instant Messaging client.
*
* Distributable under LGPL license.
* See terms of license at gnu.org.
*/
package net.java.sip.communicator.util;
import java.net.*;
import java.util.*;
import net.java.sip.communicator.service.netaddr.event.*;
import net.java.sip.communicator.util.dns.*;
import org.xbill.DNS.*;
import java.text.*;
/**
* Utility methods and fields to use when working with network addresses.
*
* @author Emil Ivov
* @author Damian Minkov
* @author Vincent Lucas
* @author Alan Kelly
*/
public class NetworkUtils
{
/**
* The <tt>Logger</tt> used by the <tt>NetworkUtils</tt> class for logging
* output.
*/
private static final Logger logger = Logger.getLogger(NetworkUtils.class);
/**
* A string containing the "any" local address for IPv6.
*/
public static final String IN6_ADDR_ANY = "::0";
/**
* A string containing the "any" local address for IPv4.
*/
public static final String IN4_ADDR_ANY = "0.0.0.0";
/**
* A string containing the "any" local address.
*/
public static final String IN_ADDR_ANY = determineAnyAddress();
/**
* The length of IPv6 addresses.
*/
private final static int IN6_ADDR_SIZE = 16;
/**
* The size of the tokens in a <tt>String</tt> representation of IPv6
* addresses.
*/
private final static int IN6_ADDR_TOKEN_SIZE = 2;
/**
* The length of IPv4 addresses.
*/
private final static int IN4_ADDR_SIZE = 4;
/**
* The maximum int value that could correspond to a port number.
*/
public static final int MAX_PORT_NUMBER = 65535;
/**
* The minimum int value that could correspond to a port number bindable
* by the SIP Communicator.
*/
public static final int MIN_PORT_NUMBER = 1024;
/**
* The random port number generator that we use in getRandomPortNumer()
*/
private static Random portNumberGenerator = new Random();
/**
* The name of the system property that users may use to override the
* address of our backup DNS resolver.
*/
public static final String PNAME_BACKUP_RESOLVER
= "net.java.sip.communicator.util.dns.BACKUP_RESOLVER";
/**
* The name of the system property that users may use to override the port
* of our backup DNS resolver.
*/
public static final String PNAME_BACKUP_RESOLVER_PORT
= "net.java.sip.communicator.util.dns.BACKUP_RESOLVER_PORT";
/**
* The address of the backup resolver we would use by default.
*/
public static final String DEFAULT_BACKUP_RESOLVER
= "backup-resolver.jitsi.net";
/**
* The name of the system property that users may use to override the
* IP address of our backup DNS resolver.
*/
public static final String PNAME_BACKUP_RESOLVER_IP
= "util.dns.BACKUP_RESOLVER_IP";
/**
* The DNSjava resolver that we use with SRV and NAPTR queries in order to
* try and smooth the problem of DNS servers that silently drop them.
*/
private static Resolver parallelResolver = null;
/**
* Determines whether the address is the result of windows auto configuration.
* (i.e. One that is in the 169.254.0.0 network)
* @param add the address to inspect
* @return true if the address is autoconfigured by windows, false otherwise.
*/
public static boolean isWindowsAutoConfiguredIPv4Address(InetAddress add)
{
return (add.getAddress()[0] & 0xFF) == 169
&& (add.getAddress()[1] & 0xFF) == 254;
}
/**
* Determines whether the address is an IPv4 link local address. IPv4 link
* local addresses are those in the following networks:
*
* 10.0.0.0 to 10.255.255.255
* 172.16.0.0 to 172.31.255.255
* 192.168.0.0 to 192.168.255.255
*
* @param add the address to inspect
* @return true if add is a link local ipv4 address and false if not.
*/
public static boolean isLinkLocalIPv4Address(InetAddress add)
{
if (add instanceof Inet4Address)
{
byte address[] = add.getAddress();
if ( (address[0] & 0xFF) == 10)
return true;
if ( (address[0] & 0xFF) == 172
&& (address[1] & 0xFF) >= 16 && address[1] <= 31)
return true;
if ( (address[0] & 0xFF) == 192
&& (address[1] & 0xFF) == 168)
return true;
return false;
}
return false;
}
/**
* Returns a random local port number that user applications could bind to.
* (i.e. above 1024).
* @return a random int located between 1024 and 65 535.
*/
public static int getRandomPortNumber()
{
return getRandomPortNumber(MIN_PORT_NUMBER, MAX_PORT_NUMBER);
}
/**
* Returns a random local port number, greater than min and lower than max.
*
* @param min the minimum allowed value for the returned port number.
* @param max the maximum allowed value for the returned port number.
*
* @return a random int located between greater than min and lower than max.
*/
public static int getRandomPortNumber(int min, int max)
{
return portNumberGenerator.nextInt(max - min) + min;
}
/**
* Returns a random local port number, greater than min and lower than max.
* If the pair flag is set to true, then the returned port number is
* guaranteed to be pair. This is useful for protocols that require this
* such as RTP
*
* @param min the minimum allowed value for the returned port number.
* @param max the maximum allowed value for the returned port number.
* @param pair specifies whether the caller would like the returned port to
* be pair.
*
* @return a random int located between greater than min and lower than max.
*/
public static int getRandomPortNumber(int min, int max, boolean pair)
{
if(pair)
{
int delta = max - min;
delta /= 2;
int port = getRandomPortNumber(min, min + delta);
return port * 2;
}
else
{
return getRandomPortNumber(min, max);
}
}
/**
* Verifies whether <tt>address</tt> could be an IPv4 address string.
*
* @param address the String that we'd like to determine as an IPv4 address.
*
* @return true if the address contained by <tt>address</tt> is an IPv4
* address and false otherwise.
*/
public static boolean isIPv4Address(String address)
{
return strToIPv4(address) != null;
}
/**
* Verifies whether <tt>address</tt> could be an IPv6 address string.
*
* @param address the String that we'd like to determine as an IPv6 address.
*
* @return true if the address contained by <tt>address</tt> is an IPv6
* address and false otherwise.
*/
public static boolean isIPv6Address(String address)
{
return strToIPv6(address) != null;
}
/**
* Checks whether <tt>address</tt> is a valid IP address string.
*
* @param address the address that we'd like to check
* @return true if address is an IPv4 or IPv6 address and false otherwise.
*/
public static boolean isValidIPAddress(String address)
{
// empty string
if (address == null || address.length() == 0)
{
return false;
}
// look for IPv6 brackets and remove brackets for parsing
boolean ipv6Expected = false;
if (address.charAt(0) == '[')
{
// This is supposed to be an IPv6 literal
if (address.length() > 2
&& address.charAt(address.length() - 1) == ']')
{
// remove brackets from IPv6
address = address.substring(1, address.length() - 1);
ipv6Expected = true;
}
else
{
return false;
}
}
// look for IP addresses
if (Character.digit(address.charAt(0), 16) != -1
|| (address.charAt(0) == ':'))
{
byte[] addr = null;
// see if it is IPv4 address
addr = strToIPv4(address);
// if not, see if it is IPv6 address
if (addr == null)
{
addr = strToIPv6(address);
}
// if IPv4 is found when IPv6 is expected
else if (ipv6Expected)
{
// invalid address: IPv4 address surrounded with brackets!
return false;
}
// if an IPv4 or IPv6 address is found
if (addr != null)
{
// is an IP address
return true;
}
}
// no matches found
return false;
}
/**
* Creates a byte array containing the specified <tt>ipv4AddStr</tt>.
*
* @param ipv4AddrStr a <tt>String</tt> containing an IPv4 address.
*
* @return a byte array containing the four bytes of the address represented
* by ipv4AddrStr or <tt>null</tt> if <tt>ipv4AddrStr</tt> does not contain
* a valid IPv4 address string.
*/
public static byte[] strToIPv4(String ipv4AddrStr)
{
if (ipv4AddrStr.length() == 0)
return null;
byte[] address = new byte[IN4_ADDR_SIZE];
String[] tokens = ipv4AddrStr.split("\\.", -1);
long currentTkn;
try
{
switch(tokens.length)
{
case 1:
//If the address was specified as a single String we can
//directly copy it into the byte array.
currentTkn = Long.parseLong(tokens[0]);
if (currentTkn < 0 || currentTkn > 0xffffffffL)
return null;
address[0] = (byte) ((currentTkn >> 24) & 0xff);
address[1] = (byte) (((currentTkn & 0xffffff) >> 16) & 0xff);
address[2] = (byte) (((currentTkn & 0xffff) >> 8) & 0xff);
address[3] = (byte) (currentTkn & 0xff);
break;
case 2:
// If the address was passed in two parts (e.g. when dealing
// with a Class A address representation), we place the
// first one in the leftmost byte and the rest in the three
// remaining bytes of the address array.
currentTkn = Integer.parseInt(tokens[0]);
if (currentTkn < 0 || currentTkn > 0xff)
return null;
address[0] = (byte) (currentTkn & 0xff);
currentTkn = Integer.parseInt(tokens[1]);
if (currentTkn < 0 || currentTkn > 0xffffff)
return null;
address[1] = (byte) ((currentTkn >> 16) & 0xff);
address[2] = (byte) (((currentTkn & 0xffff) >> 8) &0xff);
address[3] = (byte) (currentTkn & 0xff);
break;
case 3:
// If the address was passed in three parts (e.g. when
// dealing with a Class B address representation), we place
// the first two parts in the two leftmost bytes and the
// rest in the two remaining bytes of the address array.
for (int i = 0; i < 2; i++)
{
currentTkn = Integer.parseInt(tokens[i]);
if (currentTkn < 0 || currentTkn > 0xff)
return null;
address[i] = (byte) (currentTkn & 0xff);
}
currentTkn = Integer.parseInt(tokens[2]);
if (currentTkn < 0 || currentTkn > 0xffff)
return null;
address[2] = (byte) ((currentTkn >> 8) & 0xff);
address[3] = (byte) (currentTkn & 0xff);
break;
case 4:
// And now for the most common - four part case. This time
// there's a byte for every part :). Yuppiee! :)
for (int i = 0; i < 4; i++)
{
currentTkn = Integer.parseInt(tokens[i]);
if (currentTkn < 0 || currentTkn > 0xff)
return null;
address[i] = (byte) (currentTkn & 0xff);
}
break;
default:
return null;
}
}
catch(NumberFormatException e)
{
return null;
}
return address;
}
/**
* Creates a byte array containing the specified <tt>ipv6AddStr</tt>.
*
* @param ipv6AddrStr a <tt>String</tt> containing an IPv6 address.
*
* @return a byte array containing the four bytes of the address represented
* by <tt>ipv6AddrStr</tt> or <tt>null</tt> if <tt>ipv6AddrStr</tt> does
* not contain a valid IPv6 address string.
*/
public static byte[] strToIPv6(String ipv6AddrStr)
{
// Bail out if the string is shorter than "::"
if (ipv6AddrStr.length() < 2)
return null;
int colonIndex;
char currentChar;
boolean sawtDigit;
int currentTkn;
char[] addrBuff = ipv6AddrStr.toCharArray();
byte[] dst = new byte[IN6_ADDR_SIZE];
int srcb_length = addrBuff.length;
int scopeID = ipv6AddrStr.indexOf ("%");
if (scopeID == srcb_length -1)
return null;
if (scopeID != -1)
srcb_length = scopeID;
colonIndex = -1;
int i = 0, j = 0;
// Starting : mean we need to have at least one more.
if (addrBuff[i] == ':')
if (addrBuff[++i] != ':')
return null;
int curtok = i;
sawtDigit = false;
currentTkn = 0;
while (i < srcb_length)
{
currentChar = addrBuff[i++];
int chval = Character.digit(currentChar, 16);
if (chval != -1)
{
currentTkn <<= 4;
currentTkn |= chval;
if (currentTkn > 0xffff)
return null;
sawtDigit = true;
continue;
}
if (currentChar == ':')
{
curtok = i;
if (!sawtDigit)
{
if (colonIndex != -1)
return null;
colonIndex = j;
continue;
}
else if (i == srcb_length)
{
return null;
}
if (j + IN6_ADDR_TOKEN_SIZE > IN6_ADDR_SIZE)
return null;
dst[j++] = (byte) ((currentTkn >> 8) & 0xff);
dst[j++] = (byte) (currentTkn & 0xff);
sawtDigit = false;
currentTkn = 0;
continue;
}
if (currentChar == '.' && ((j + IN4_ADDR_SIZE) <= IN6_ADDR_SIZE))
{
String ia4 = ipv6AddrStr.substring(curtok, srcb_length);
// check this IPv4 address has 3 dots, ie. A.B.C.D
int dot_count = 0, index=0;
while ((index = ia4.indexOf ('.', index)) != -1)
{
dot_count ++;
index ++;
}
if (dot_count != 3)
return null;
byte[] v4addr = strToIPv4(ia4);
if (v4addr == null)
return null;
for (int k = 0; k < IN4_ADDR_SIZE; k++)
{
dst[j++] = v4addr[k];
}
sawtDigit = false;
break; /* '\0' was seen by inet_pton4(). */
}
return null;
}
if (sawtDigit)
{
if (j + IN6_ADDR_TOKEN_SIZE > IN6_ADDR_SIZE)
return null;
dst[j++] = (byte) ((currentTkn >> 8) & 0xff);
dst[j++] = (byte) (currentTkn & 0xff);
}
if (colonIndex != -1)
{
int n = j - colonIndex;
if (j == IN6_ADDR_SIZE)
return null;
for (i = 1; i <= n; i++)
{
dst[IN6_ADDR_SIZE - i] = dst[colonIndex + n - i];
dst[colonIndex + n - i] = 0;
}
j = IN6_ADDR_SIZE;
}
if (j != IN6_ADDR_SIZE)
return null;
byte[] newdst = mappedIPv4ToRealIPv4(dst);
if (newdst != null)
{
return newdst;
}
else
{
return dst;
}
}
/**
* Returns array of hosts from the SRV record of the specified domain.
* The records are ordered against the SRV record priority
* @param domain the name of the domain we'd like to resolve (_proto._tcp
* included).
* @return an array of InetSocketAddress containing records returned by the DNS
* server - address and port .
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static InetSocketAddress[] getSRVRecords(String domain)
throws ParseException
{
Record[] records = null;
try
{
Lookup lookup = createLookup(domain, Type.SRV);
records = lookup.run();
}
catch (TextParseException tpe)
{
logger.error("Failed to parse domain=" + domain, tpe);
throw new ParseException(tpe.getMessage(), 0);
}
if (records == null)
{
return null;
}
String[][] pvhn = new String[records.length][4];
for (int i = 0; i < records.length; i++)
{
SRVRecord srvRecord = (SRVRecord) records[i];
pvhn[i][0] = "" + srvRecord.getPriority();
pvhn[i][1] = "" + srvRecord.getWeight();
pvhn[i][2] = "" + srvRecord.getPort();
pvhn[i][3] = srvRecord.getTarget().toString();
if (pvhn[i][3].endsWith("."))
{
pvhn[i][3] = pvhn[i][3].substring(0, pvhn[i][3].length() - 1);
}
}
/* sort the SRV RRs by RR value (lower is preferred) */
Arrays.sort(pvhn, new Comparator<String[]>()
{
public int compare(String array1[], String array2[])
{
return (Integer.parseInt( array1[0])
- Integer.parseInt( array2[0]));
}
});
/* put sorted host names in an array, get rid of any trailing '.' */
ArrayList<InetSocketAddress> sortedHostNames
= new ArrayList<InetSocketAddress>();
for (int i = 0; i < pvhn.length; i++)
{
InetSocketAddress address =
getARecord(pvhn[i][3], Integer.valueOf(pvhn[i][2]));
if(address != null)
sortedHostNames.add(address);
}
if (logger.isTraceEnabled())
{
logger.trace("DNS SRV query for domain " + domain + " returned:");
for (int i = 0; i < sortedHostNames.size(); i++)
{
if (logger.isTraceEnabled())
logger.trace(sortedHostNames.get(i));
}
}
return sortedHostNames.toArray(new InetSocketAddress[0]);
}
/**
* Returns an <tt>InetSocketAddress</tt> representing the first SRV
* record available for the specified domain or <tt>null</tt> if there are
* not SRV records for <tt>domain</tt>.
*
* @param domain the name of the domain we'd like to resolve.
* @param service the service that we are trying to get a record for.
* @param proto the protocol that we'd like <tt>service</tt> on.
*
* @return the first InetSocketAddress containing records returned by the
* DNS server - address and port .
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static InetSocketAddress getSRVRecord( String service,
String proto,
String domain)
throws ParseException
{
InetSocketAddress[] records = getSRVRecords("_" + service
+ "._" + proto
+ "." + domain);
if(records == null || records.length == 0)
return null;
return records[0];
}
/**
* Returns an <tt>InetSocketAddress</tt> representing the first SRV
* record available for the specified domain or <tt>null</tt> if there are
* not SRV records for <tt>domain</tt>.
*
* @param domain the name of the domain we'd like to resolve.
* @param service the service that we are trying to get a record for.
* @param proto the protocol that we'd like <tt>service</tt> on.
*
* @return the InetSocketAddress[] containing records returned by the
* DNS server - address and port .
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static InetSocketAddress[] getSRVRecords(String service,
String proto,
String domain)
throws ParseException
{
InetSocketAddress[] records = getSRVRecords("_" + service
+ "._" + proto
+ "." + domain);
if(records == null || records.length == 0)
return null;
return records;
}
/**
* Makes a NAPTR query and returns the result. The returned records are an
* array of [Order, Service(Transport) and Replacement
* (the srv to query for servers and ports)] this all for supplied
* <tt>domain</tt>.
*
* @param domain the name of the domain we'd like to resolve.
* @return an array with the values or null if no records found.
*
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static String[][] getNAPTRRecords(String domain)
throws ParseException
{
Record[] records = null;
try
{
Lookup lookup = createLookup(domain, Type.NAPTR);
records = lookup.run();
}
catch (TextParseException tpe)
{
logger.error("Failed to parse domain="+domain, tpe);
throw new ParseException(tpe.getMessage(), 0);
}
if (records == null)
{
return null;
}
String[][] recVals = new String[records.length][3];
for (int i = 0; i < records.length; i++)
{
NAPTRRecord r = (NAPTRRecord)records[i];
// todo - check here for broken records as missing transport
recVals[i][0] = "" + r.getOrder();
recVals[i][1] = getProtocolFromNAPTRRecords(r.getService());
String replacement = r.getReplacement().toString();
if (replacement.endsWith("."))
{
recVals[i][2] =
replacement.substring(0, replacement.length() - 1);
}
else
recVals[i][2] = replacement;
}
/* sort the SRV RRs by RR value (lower is preferred) */
Arrays.sort(recVals, new Comparator<String[]>()
{
public int compare(String array1[], String array2[])
{
return (Integer.parseInt( array1[0])
- Integer.parseInt( array2[0]));
}
});
return recVals;
}
/**
* Returns the mapping from rfc3263 between service and the protocols.
*
* @param service the service from NAPTR record.
* @return the protocol TCP, UDP or TLS.
*/
private static String getProtocolFromNAPTRRecords(String service)
{
if(service.equalsIgnoreCase("SIP+D2U"))
return "UDP";
else if(service.equalsIgnoreCase("SIP+D2T"))
return "TCP";
else if(service.equalsIgnoreCase("SIP+D2TS"))
return "TLS";
else
return null;
}
/**
* Creates an InetAddress from the specified <tt>hostAddress</tt>. The point
* of using the method rather than creating the address by yourself is that
* it would first check whether the specified <tt>hostAddress</tt> is indeed
* a valid ip address. It this is the case, the method would create the
* <tt>InetAddress</tt> using the <tt>InetAddress.getByAddress()</tt>
* method so that no DNS resolution is attempted by the JRE. Otherwise
* it would simply use <tt>InetAddress.getByName()</tt> so that we would an
* <tt>InetAddress</tt> instance even at the cost of a potential DNS
* resolution.
*
* @param hostAddress the <tt>String</tt> representation of the address
* that we would like to create an <tt>InetAddress</tt> instance for.
*
* @return an <tt>InetAddress</tt> instance corresponding to the specified
* <tt>hostAddress</tt>.
*
* @throws UnknownHostException if any of the <tt>InetAddress</tt> methods
* we are using throw an exception.
*/
public static InetAddress getInetAddress(String hostAddress)
throws UnknownHostException
{
//is null
if (hostAddress == null || hostAddress.length() == 0)
{
throw new UnknownHostException(
hostAddress + " is not a valid host address");
}
//transform IPv6 literals into normal addresses
if (hostAddress.charAt(0) == '[')
{
// This is supposed to be an IPv6 literal
if (hostAddress.length() > 2
&& hostAddress.charAt(hostAddress.length()-1) == ']')
{
hostAddress = hostAddress.substring(1, hostAddress.length() -1);
}
else
{
// This was supposed to be a IPv6 address, but it's not!
throw new UnknownHostException(hostAddress);
}
}
if (NetworkUtils.isValidIPAddress(hostAddress))
{
byte[] addr = null;
// attempt parse as IPv4 address
addr = strToIPv4(hostAddress);
// if not IPv4, parse as IPv6 address
if (addr == null)
{
addr = strToIPv6(hostAddress);
}
return InetAddress.getByAddress(hostAddress, addr);
}
else
{
return InetAddress.getByName(hostAddress);
}
}
/**
* Returns array of hosts from the A record of the specified domain.
* The records are ordered against the A record priority
* @param domain the name of the domain we'd like to resolve.
* @param port the port number of the returned <tt>InetSocketAddress</tt>
* @return an array of InetSocketAddress containing records returned by the
* DNS server - address and port .
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static InetSocketAddress getARecord(String domain, int port)
throws ParseException
{
Record[] records = null;
try
{
//note that we intentionally do not use our parallel resolver here.
//for starters we'd like to make sure that it works well enough
//with SRV and NAPTR queries. We may then also adopt it for As
//and AAAAs once it proves to be reliable (posted on: 2010-11-24)
Lookup lookup = createLookup(domain, Type.A);
records = lookup.run();
}
catch (TextParseException tpe)
{
logger.error("Failed to parse domain="+domain, tpe);
throw new ParseException(tpe.getMessage(), 0);
}
if (records != null && records.length > 0)
{
return new InetSocketAddress(
((ARecord)records[0]).getAddress(),
port);
}
else
{
//No A record found
return null;
}
}
/**
* Returns array of hosts from the AAAA record of the specified domain.
* The records are ordered against the AAAA record priority
* @param domain the name of the domain we'd like to resolve.
* @param port the port number of the returned <tt>InetSocketAddress</tt>
* @return an array of InetSocketAddress containing records returned by the
* DNS server - address and port .
* @throws ParseException if <tt>domain</tt> is not a valid domain name.
*/
public static InetSocketAddress getAAAARecord(String domain, int port)
throws ParseException
{
Record[] records = null;
try
{
//note that we intentionally do not use our parallel resolver here.
//for starters we'd like to make sure that it works well enough
//with SRV and NAPTR queries. We may then also adopt it for As
//and AAAAs once it proves to be reliable (posted on: 2010-11-24)
Lookup lookup = createLookup(domain, Type.AAAA);
records = lookup.run();
}
catch (TextParseException tpe)
{
logger.error("Failed to parse domain="+domain, tpe);
throw new ParseException(tpe.getMessage(), 0);
}
if (records != null && records.length > 0)
{
return new InetSocketAddress(
((AAAARecord)records[0]).getAddress(),
port);
}
else
{
//"No AAAA record found
return null;
}
}
/**
* Tries to determine if this host supports IPv6 addresses (i.e. has at
* least one IPv6 address) and returns IN6_ADDR_ANY or IN4_ADDR_ANY
* accordingly. This method is only used to initialize IN_ADDR_ANY so that
* it could be used when binding sockets. The reason we need it is because
* on mac (contrary to lin or win) binding a socket on 0.0.0.0 would make
* it deaf to IPv6 traffic. Binding on ::0 does the trick but that would
* fail on hosts that have no IPv6 support. Using the result of this method
* provides an easy way to bind sockets in cases where we simply want any
* IP packets coming on the port we are listening on (regardless of IP
* version).
*
* @return IN6_ADDR_ANY or IN4_ADDR_ANY if this host supports or not IPv6.
*/
private static String determineAnyAddress()
{
Enumeration<NetworkInterface> ifaces;
try
{
ifaces = NetworkInterface.getNetworkInterfaces();
}
catch (SocketException e)
{
if (logger.isDebugEnabled())
logger.debug("Couldn't retrieve local interfaces.", e);
return IN4_ADDR_ANY;
}
while(ifaces.hasMoreElements())
{
Enumeration<InetAddress> addrs
= ifaces.nextElement().getInetAddresses();
while (addrs.hasMoreElements())
{
if(addrs.nextElement() instanceof Inet6Address)
return IN6_ADDR_ANY;
}
}
return IN4_ADDR_ANY;
}
/**
* Determines whether <tt>port</tt> is a valid port number bindable by an
* application (i.e. an integer between 1024 and 65535).
*
* @param port the port number that we'd like verified.
*
* @return <tt>true</tt> if port is a valid and bindable port number and
* <tt>alse</tt> otherwise.
*/
public static boolean isValidPortNumber(int port)
{
return MIN_PORT_NUMBER < port && port < MAX_PORT_NUMBER;
}
/**
* Returns an IPv4 address matching the one mapped in the IPv6
* <tt>addr</tt>. Both input and returned value are in network order.
*
* @param addr a String representing an IPv4-Mapped address in textual
* format
*
* @return a byte array numerically representing the IPv4 address
*/
public static byte[] mappedIPv4ToRealIPv4(byte[] addr)
{
if (isMappedIPv4Addr(addr))
{
byte[] newAddr = new byte[IN4_ADDR_SIZE];
System.arraycopy(addr, 12, newAddr, 0, IN6_ADDR_SIZE);
return newAddr;
}
return null;
}
/**
* Utility method to check if the specified <tt>address</tt> is an IPv4
* mapped IPv6 address.
*
* @param address the address that we'd like to determine as an IPv4 mapped
* one or not.
*
* @return <tt>true</tt> if address is an IPv4 mapped IPv6 address and
* <tt>false</tt> otherwise.
*/
private static boolean isMappedIPv4Addr(byte[] address)
{
if (address.length < IN6_ADDR_SIZE)
{
return false;
}
if ((address[0] == 0x00) && (address[1] == 0x00)
&& (address[2] == 0x00) && (address[3] == 0x00)
&& (address[4] == 0x00) && (address[5] == 0x00)
&& (address[6] == 0x00) && (address[7] == 0x00)
&& (address[8] == 0x00) && (address[9] == 0x00)
&& (address[10] == (byte)0xff)
&& (address[11] == (byte)0xff))
{
return true;
}
return false;
}
/**
* Creates a new {@link Lookup} instance using our own {@link
* ParallelResolver}.
*
* @param domain the domain we will be resolving
* @param type the type of the record we will be trying to obtain.
*
* @return the newly created {@link Lookup} instance.
*
* @throws TextParseException if <tt>domain</tt> is not a valid domain name.
*/
private static Lookup createLookup(String domain, int type)
throws TextParseException
{
Lookup lookup = new Lookup(domain, type);
//initiate our global parallel resolver if this is our first ever
//DNS query.
if(parallelResolver == null)
{
try
{
String customRslvrAddr
= System.getProperty(PNAME_BACKUP_RESOLVER);
String rslvrAddrStr = DEFAULT_BACKUP_RESOLVER;
String customRslvrIP
= UtilActivator.getResources().getSettingsString(
PNAME_BACKUP_RESOLVER_IP);
if(! StringUtils.isNullOrEmpty( customRslvrAddr ))
rslvrAddrStr = customRslvrAddr;
InetAddress resolverAddress = getInetAddress(rslvrAddrStr);
if(resolverAddress == null)
{
/* name resolution failed for backup DNS resolver,
* try with the IP address of the default backup resolver
*/
resolverAddress = getInetAddress(customRslvrIP);
}
int rslvrPort = SimpleResolver.DEFAULT_PORT;
//just in case someone said sth else ... and we want no errs
try
{
rslvrPort = Integer.getInteger(
PNAME_BACKUP_RESOLVER_PORT);
}
catch(Throwable t)
{
logger.info("Ignoring invalid resolver port.");
}
InetSocketAddress resolverSockAddr
= new InetSocketAddress(resolverAddress, rslvrPort);
parallelResolver = new ParallelResolver(
new InetSocketAddress[]{resolverSockAddr});
// listens for network changes up/down so we can reset
// dns configuration
UtilActivator.getNetworkAddressManagerService()
.addNetworkConfigurationChangeListener(
new NetworkListener());
}
catch(Throwable t)
{
//We don't want to a problem with our parallel resolver to
//make our entire DNS resolution to fail so in case something
//goes wrong during initialization so we default to the
//dns java default resolver
logger.info("failed to initialize parallel resolver. we will "
+"be using dnsjava's default one instead");
if(logger.isDebugEnabled())
logger.debug("exception was: ", t);
parallelResolver = Lookup.getDefaultResolver();
}
}
// make sure we are not currently resetting the resolver
synchronized(parallelResolver)
{
lookup.setResolver( parallelResolver );
}
return lookup;
}
/**
* Listens when network is going from down to up and
* resets dns configuration.
*/
private static class NetworkListener
implements NetworkConfigurationChangeListener
{
/**
* Fired when a change has occurred in the
* computer network configuration.
*
* @param event the change event.
*/
public void configurationChanged(ChangeEvent event)
{
if(event.getType() == ChangeEvent.IFACE_UP)
{
reloadDnsResolverConfig();
}
}
}
/**
* Reloads dns server configuration in the resolver.
*/
public static void reloadDnsResolverConfig()
{
if(parallelResolver instanceof ParallelResolver)
{
synchronized(parallelResolver)
{
((ParallelResolver)parallelResolver).reset();
}
}
}
}