A major overhaul of the CARP implementation. The ip_carp.c was started

from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.

The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.

ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.

To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]

The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.

Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!

PR:		kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by:	bz
Submitted by:	bz [1]

1 files changed, 11 insertions, 0 deletions

diff --git a/UPDATING b/UPDATING
index 44f902d..575a037 100644
--- a/UPDATING
+++ b/UPDATING
@@ -22,6 +22,17 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 10.x IS SLOW:
 	machines to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)
 
+20111215:
+	The carp(4) facility has been changed significantly. Configuration
+	of the CARP protocol via ifconfig(8) has changed, as well as format
+	of CARP events submitted to devd(8) has changed. See manual pages
+	for more information. The arpbalance feature of carp(4) is currently
+	not supported anymore.
+
+	Size of struct in_aliasreq, struct in6_aliasreq has changed. User
+	utilities using SIOCAIFADDR, SIOCAIFADDR_IN6, e.g. ifconfig(8),
+	need to be recompiled.
+
 20111122:
 	The acpi_wmi(4) status device /dev/wmistat has been renamed to
 	/dev/wmistat0.