HEAD UP - IPv4 addresses now have flags

[Roy Marples <roy%marples.name@localhost>]

Hi List

This is a heads up about a recent kernel change to add flags to IPv4
addresses so they can be marked as tentative, duplicated and detached.
This mimics the equivalent IPv6 functionality.

Applications that listen for new addresses added and bind to them should
check that the address does not have the IN_IFF_TENTATIVE flag using the
SIOCGIFAFLAG_IN ioctl. An example of this can be found here:
http://cvsweb.netbsd.org/bsdweb.cgi/src/external/bsd/ntp/dist/ntpd/ntp_io.c.diff?r1=1.17&r2=1.18&only_with_tag=MAIN&f=u

Applications that don't may produce warnings that they cannot bind to
the address. They should still work as the kernel will re-announce the
address when the tentative flag is dropped.

Roy