[Openswan Users] ERROR: netlink response for Add SA comp.3f10 at xxx.xxx.xxx.xxx included errno 22: Invalid argument - clarifications

[Alex Crow]

On 02/03/11 10:01, Alex Crow wrote:
> Hi,
>
> I have a very strange issue. I have had openswan running absolutely fine
> for a few years on an old machine in my office to connect to a network
> at a colo. Just recently, to save power, I decided to build a
> virtualised firewall/router box, running on KVM on a fully up-to-date
> Ubuntu Maverick server box. The guest is Lucid (10.04.2 LTS), with
> kernel 2.6.32-25-server. OpenSWAN version is 2.6.23+dfsg-1ubuntu1.
>
> What is odd is that the virtualised OpenSWAN fails to connect any
> connection with "compress=yes" with the following errors:
>
> Mar  1 21:34:29 firewall pluto[1418]: "colo-alex" #14: ERROR: netlink
> response for Add SA comp.3f10 at xxx.xxx.xxx.xxx included errno 22: Invalid
> argument
> Mar  1 21:34:29 firewall pluto[1418]: | add_sa ipcomp failed
>
> Connection def:
>
> conn colo-alex
>           # Left security gateway, subnet behind it, next hop toward right.
>           leftid=@ipsecdr.integrafin.co.uk
>           left=xxx.xxx.xxx.xxx
>           leftsubnet=192.168.pp.0/24
>           leftnexthop=xxx.xxx.xxx.xxy
>           leftrsasigkey=<hidden>
>           # Right security gateway, subnet behind it, next hop toward left.
>           rightid=@ipsec.alex.net
>           right=yyy.yyy.yyy.yyy
>           rightsubnet=192.168.qq.0/24
>           rightrsasigkey=<hidden>
>           rightnexthop=yyy.yyy.yyy.yyy.yyz
>           # To authorize this connection, but not actually start it, at
> startup,
>           # uncomment this.
>           auto=start
>           compress=yes
>           esp=3des-md5
>
> I have the ipcomp and xfrm modules loaded OK:
> root at firewall:~# lsmod | grep ipcomp
> ipcomp                  2212  0
> ipcomp6                 2214  0
> xfrm_ipcomp             5148  2 ipcomp,ipcomp6
> xfrm6_tunnel            7935  1 ipcomp6
> root at firewall:~# lsmod | grep xfrm
> xfrm_user              21932  2
> xfrm4_mode_beet         2131  0
> xfrm4_tunnel            1979  0
> tunnel4                 2909  1 xfrm4_tunnel
> xfrm4_mode_tunnel       2000  24
> xfrm4_mode_transport     1511  0
> xfrm6_mode_transport     1575  0
> xfrm6_mode_ro           1380  0
> xfrm6_mode_beet         2082  0
> xfrm6_mode_tunnel       1904  0
> xfrm_ipcomp             5148  2 ipcomp,ipcomp6
> xfrm6_tunnel            7935  1 ipcomp6
> tunnel6                 2712  1 xfrm6_tunnel
>
> I have another connection between a remote server in another country,
> same guest OS, kernel, OpenSWAN version, which does not have this issue
> with compressed connections (unless they are talking to my virtual
> gateway). The only difference is that the VM host is Lucid instead of
> Maverick. The server at the "opposite" end of both of these connections
> (a "real" box) has a 2.6.18 kernel and runs OpenSWAN 2.4.7.
>
> This same offshore remote server also shows the same errors (they show
> at both ends) for the connection to my virtual machine. If I change to
> compress=no the error does not show up.
>
> Has anyone come across this problem before?
>
> Thanks
>
> Alex
>
>
>
>

Just realised this reads confusingly:

To summarise:

Offshore VM (same kernel/OpenSWAN as my home office) VM connects fine to 
the colo with compress=yes. Only difference to my home office setup is 
the host OS version/kernel.

Home office VM fails to connect to the colo when compress=yes.

Home office VM fails to connect to the offshore VM when compress=yes.

I have checked the sysctl.conf on all boxes and all relevant options are 
the same (or default).

All the gateways have a shorewall firewall set up. I have checked 
everything in the shorewall configs and no messages are being logged 
about rejected or dropped packets on the problematic gateways.

I can provide further info if required, but things like an ipsec barf I 
would have to sanitise to remove public IPs and keys.

If anyone can help it would be most appreciated.

Thanks

Alex

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