CARP - immediate INIT-MASTER transition when preempt enabled , bug from openbsd38

[Damien Fleuriot]

Hello -net,



Just following up on these 2 PRs, respectively for 8.x and 9.0-BETA3:

8.x:	http://www.freebsd.org/cgi/query-pr.cgi?pr=161123
9.0b3:	http://www.freebsd.org/cgi/query-pr.cgi?pr=161483


There is a bug with CARP where a CARP interface will immediately
transition from INIT to MASTER if net.inet.carp.preempt=1 even if there
is a faster MASTER already present on the network.

This is a bug from OpenBSD 3.8 and lower's implementation of CARP, which
remains in 8.2 and 9.0 to this day.

>From OBSD 3.9's changelog:
http://www.openbsd.org/plus39.html
"In carp(4), fix a bug where lower prioritized hosts would invalidly
switch to MASTER for a short time at boot-up."



I have provided patches in both PRs for sys/netinet/ip_carp.c and would
like to ensure this gets looked at, and makes 9.0's release.

We have tested the patch in production on 8.2 and that solved our problem.


Is there anything I can do to help ?