net.i2p.router.transport.udp

Class MTU

java.lang.Object

net.i2p.router.transport.udp.MTU

public class MTU
extends Object

Get the MTU for the network interface of an address. Not available until Java 6 / Android API 9. Public only for command line test. Not for external use, not a public API.

Method Summary

Modifier and Type	Method and Description
static int	getMTU(InetAddress ia, boolean isSSU2) The MTU for the socket interface, if available.
static void	main(String[] args)
static int	rectify(boolean isIPv6, int mtu)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getMTU

public static int getMTU(InetAddress ia,
                         boolean isSSU2)

The MTU for the socket interface, if available. Not available for Java 5. Note that we don't return the value for the default interface if we can't find the address. Finding the default interface is hard, altough we could perhaps just look for the first non-loopback address. But the MTU of the default route probably isn't relevant. For SSU2 MTU, values lower than PeerState2.MIN_MTU may be returned, so the caller can determine if SSU2 should be supported.

Parameters:

ia - null ok

isSSU2 - if true, calculate SSU2 MTU

Returns:

0 if Java 5, or if not bound to an address; limited to range MIN_MTU to LARGE_MTU for SSU 1.

main

public static void main(String[] args)

rectify

public static int rectify(boolean isIPv6,
                          int mtu)

Returns:

min of PeerState.MIN_MTU, max of PeerState.LARGE_MTU, rectified so rv % 16 == 12 (IPv4) or rv % 16 == 0 (IPv6)