org.xbill.DNS

Class ClientSubnetOption

java.lang.Object

org.xbill.DNS.EDNSOption

org.xbill.DNS.ClientSubnetOption

public class ClientSubnetOption
extends EDNSOption

The Client Subnet EDNS Option, defined in http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-00 ("Client subnet in DNS requests"). The option is used to convey information about the IP address of the originating client, so that an authoritative server can make decisions based on this address, rather than the address of the intermediate caching name server. The option is transmitted as part of an OPTRecord in the additional section of a DNS message, as defined by RFC 2671 (EDNS0). The wire format of the option contains a 2-byte length field (1 for IPv4, 2 for IPv6), a 1-byte source netmask, a 1-byte scope netmask, and an address truncated to the source netmask length (where the final octet is padded with bits set to 0)

Author:

Brian Wellington, Ming Zhou <mizhou@bnivideo.com>, Beaumaris Networks

See Also:

OPTRecord

Nested Class Summary

Nested classes/interfaces inherited from class org.xbill.DNS.EDNSOption

EDNSOption.Code

Constructor Summary

Constructors

Constructor and Description
ClientSubnetOption(int sourceNetmask, java.net.InetAddress address) Construct a Client Subnet option with scope netmask set to 0.
ClientSubnetOption(int sourceNetmask, int scopeNetmask, java.net.InetAddress address) Construct a Client Subnet option.

Method Summary

Methods

Modifier and Type	Method and Description
java.net.InetAddress	getAddress() Returns the IP address of the client.
int	getFamily() Returns the family of the network address.
int	getScopeNetmask() Returns the scope netmask.
int	getSourceNetmask() Returns the source netmask.

Methods inherited from class org.xbill.DNS.EDNSOption

equals, fromWire, getCode, hashCode, toString, toWire

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ClientSubnetOption

public ClientSubnetOption(int sourceNetmask,
                  int scopeNetmask,
                  java.net.InetAddress address)

Construct a Client Subnet option. Note that the number of significant bits in the address must not be greater than the supplied source netmask. There may also be issues related to Java's handling of mapped addresses

Parameters:

sourceNetmask - The length of the netmask pertaining to the query. In replies, it mirrors the same value as in the requests.

scopeNetmask - The length of the netmask pertaining to the reply. In requests, it MUST be set to 0. In responses, this may or may not match the source netmask.

address - The address of the client.

ClientSubnetOption

public ClientSubnetOption(int sourceNetmask,
                  java.net.InetAddress address)

Construct a Client Subnet option with scope netmask set to 0.

Parameters:

sourceNetmask - The length of the netmask pertaining to the query. In replies, it mirrors the same value as in the requests.

address - The address of the client.

See Also:

ClientSubnetOption

Method Detail

getFamily

public int getFamily()

Returns the family of the network address. This will be either IPv4 (1) or IPv6 (2).

getSourceNetmask

public int getSourceNetmask()

Returns the source netmask.

getScopeNetmask

public int getScopeNetmask()

Returns the scope netmask.

getAddress

public java.net.InetAddress getAddress()

Returns the IP address of the client.