Commit Graph

8 Commits

Author SHA1 Message Date
Gleb Smirnoff
f08535f872 Restore a feature that was present in 5.x and 6.x, and was cleared in
7.x, 8.x and 9.x with pf(4) imports: pfsync(4) should suppress CARP
preemption, while it is running its bulk update.

However, reimplement the feature in more elegant manner, that is
partially inspired by newer OpenBSD:

- Rename term "suppression" to "demotion", to match with OpenBSD.
- Keep a global demotion factor, that can be raised by several
  conditions, for now these are:
  - interface goes down
  - carp(4) has problems with ip_output() or ip6_output()
  - pfsync performs bulk update
- Unlike in OpenBSD the demotion factor isn't a counter, but
  is actual value added to advskew. The adjustment values for
  particular error conditions are also configurable, and their
  defaults are maximum advskew value, so a single failure bumps
  demotion to maximum. This is for POLA compatibility, and should
  satisfy most users.
- Demotion factor is a writable sysctl, so user can do
  foot shooting, if he desires to.
2011-12-20 13:53:31 +00:00
Gleb Smirnoff
08b68b0e4c 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]
2011-12-16 12:16:56 +00:00
Will Andrews
9963e8a52c Unbreak LINT by moving all carp hooks to net/if.c / netinet/ip_carp.h, with
the appropriate ifdefs.

Reviewed by:	bz
Approved by:	ken (mentor)
2010-08-11 20:18:19 +00:00
Will Andrews
54bfbd5153 Allow carp(4) to be loaded as a kernel module. Follow precedent set by
bridge(4), lagg(4) etc. and make use of function pointers and
pf_proto_register() to hook carp into the network stack.

Currently, because of the uncertainty about whether the unload path is free
of race condition panics, unloads are disallowed by default.  Compiling with
CARPMOD_CAN_UNLOAD in CFLAGS removes this anti foot shooting measure.

This commit requires IP6PROTOSPACER, introduced in r211115.

Reviewed by:	bz, simon
Approved by:	ken (mentor)
MFC after:	2 weeks
2010-08-11 00:51:50 +00:00
Robert Watson
6bf65bcf3a Update stats in struct carpstats using two new macros: CARPSTATS_ADD()
and CARPSTATS_INC(), rather than directly manipulating the fields of
the structure.  This will make it easier to change the implementation
of these statistics, such as using per-CPU versions of the data
structure.

MFC after:	3 days
2009-04-12 14:19:37 +00:00
Warner Losh
850adc0cd7 Make sure that carp_header is 36 bytes long 2006-12-01 18:37:41 +00:00
Gleb Smirnoff
0fa0801895 o Introduce carp_multicast_cleanup(), which removes and frees
multicast addresses from carp interface. [1]
o Rewrite carpdetach(), so that it does the following things: [1]
  - Stops callouts.
  - Decrements carp_suppress_preempt, if needed.
  - Downs interface and sets CARP state to INIT.
  - Calls carp_multicast_cleanup().
  - Detaches softc from carp_if and if we are the last frees
    the carp_if.
o Use new carpdetach() in carp_clone_destroy().
o In carp_ifdetach() acquire the carp_if lock and cleanup all
  interfaces hanging on carp_if. [1]
o Make carp_ifdetach() static and use EVENT(9) to call it
  from if_detach(). [2]
o In carp_setrun() exit if the softc doesn't have a valid pointer
  to parent. [1]

Obtained from:	OpenBSD [1]
Submitted by:	Dan Lukes <dan obluda.cz> [2]
PR:		kern/82908 [2]
2006-03-21 14:29:48 +00:00
Gleb Smirnoff
a97719482d Add CARP (Common Address Redundancy Protocol), which allows multiple
hosts to share an IP address, providing high availability and load
balancing.

Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.

FreeBSD port done solely by Max Laier.

Patch by:	mlaier
Obtained from:	OpenBSD (mickey, mcbride)
2005-02-22 13:04:05 +00:00