[PATCH v2 0/4] IPVS full NAT support + netfilter 'ipvs' match support

From: Hannes Eder
Date: Tue Sep 29 2009 - 09:12:18 EST


The following series implements full NAT support for IPVS. The
approach is via a minimal change to IPVS (make friends with
nf_conntrack) and adding a netfilter matcher, kernel- and user-space
part, i.e. xt_ipvs and libxt_ipvs.

Example usage:

% ipvsadm -A -t 192.168.100.30:80 -s rr
% ipvsadm -a -t 192.168.100.30:80 -r 192.168.10.20:80 -m
# ...

# Source NAT for VIP 192.168.100.30:80
% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 \
> --vport 80 -j SNAT --to-source 192.168.10.10

or SNAT-ing only a specific real server:

% iptables -t nat -A POSTROUTING --dst 192.168.11.20 \
> -m ipvs --vaddr 192.168.100.30/32 -j SNAT --to-source 192.168.10.10


First of all, thanks for all the feedback. This is the changelog for v2:

- Make ip_vs_ftp work again. Setup nf_conntrack expectations for
related data connections (based on Julian's patch see
http://www.ssi.bg/~ja/nfct/) and let nf_conntrack/nf_nat do the
packet mangling and the TCP sequence adjusting.

This change rises the question how to deal with ip_vs_sync? Does it
work together with conntrackd? Wild idea: what about getting rid of
ip_vs_sync and piggy packing all on nf_conntrack and use conntrackd?

Any comments on this?

- xt_ipvs: add new rule '--vportctl port' to match the VIP port of the
controlling connection, e.g. port 21 for FTP. Can be used to match
a related data connection for FTP:

# SNAT FTP control connection
% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 \
> --vport 21 -j SNAT --to-source 192.168.10.10

# SNAT FTP passive data connection
% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 \
> --vportctl 21 -j SNAT --to-source 192.168.10.10

- xt_ipvs: use 'par->family' instead of 'skb->protocol'

- xt_ipvs: add ipvs_mt_check and restrict to NFPROTO_IPV4 and NFPROTO_IPV6

- Call nf_conntrack_alter_reply(), so helper lookup is performed based
on the changed tuple.

Changes to the linux kernel (rebased to next-20090925):

Hannes Eder (3):
netfilter: xt_ipvs (netfilter matcher for IPVS)
IPVS: make friends with nf_conntrack
IPVS: make FTP work with full NAT support


include/linux/netfilter/xt_ipvs.h | 25 +++++
include/net/ip_vs.h | 2
net/netfilter/Kconfig | 9 ++
net/netfilter/Makefile | 1
net/netfilter/ipvs/Kconfig | 4 -
net/netfilter/ipvs/ip_vs_app.c | 43 ---------
net/netfilter/ipvs/ip_vs_core.c | 37 -------
net/netfilter/ipvs/ip_vs_ftp.c | 178 ++++++++++++++++++++++++++++++++---
net/netfilter/ipvs/ip_vs_proto.c | 1
net/netfilter/ipvs/ip_vs_xmit.c | 30 ++++++
net/netfilter/xt_ipvs.c | 187 +++++++++++++++++++++++++++++++++++++
11 files changed, 418 insertions(+), 99 deletions(-)
create mode 100644 include/linux/netfilter/xt_ipvs.h
create mode 100644 net/netfilter/xt_ipvs.c


Changes to iptables (relative to 1.4.5):

Hannes Eder (1):
libxt_ipvs: user-space lib for netfilter matcher xt_ipvs

configure.ac | 11 +
extensions/libxt_ipvs.c | 365 +++++++++++++++++++++++++++++++++++++
extensions/libxt_ipvs.man | 24 ++
include/linux/netfilter/xt_ipvs.h | 25 +++
4 files changed, 422 insertions(+), 3 deletions(-)
create mode 100644 extensions/libxt_ipvs.c
create mode 100644 extensions/libxt_ipvs.man
create mode 100644 include/linux/netfilter/xt_ipvs.h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/