fix dreaded "Unknown error 4294967295"

[removed CC: webmastergnumonks.org]

Denis Vlasenko wrote:
> I have some troubles setting up firewall on AMD64
kernel
> with 32-bit userspace.
> 
> When I pointed KERNEL_DIR= to the build directory
> of currently running kernel, i saw
-DKERNEL_64_USERSPACE_32
> in gcc commands and resulting iptables was utterly
useless.
> It was throwing "Unknown error 4294967295" on
practically anything.
> 
> I rebuilt it, pointing KERNEL_DIR= to pristine,
unconfigured
> 2.6.18 source. Now it works most of the time.
> 
> However, on some commands it does not:
> 
> iptables -t nat -A OUTPUT --match connmark --mark 22 -j
RETURN
> iptables -t nat -A OUTPUT -j CONNMARK --set-mark 22
> 
> give the same error and in dmesg I see:
> 
> ip_tables: connmark match: invalid size 24 != 12
> ip_tables: CONNMARK target: invalid size 24 != 12
> ip_tables: connmark match: invalid size 24 != 12
> ip_tables: CONNMARK target: invalid size 24 != 12
> 
> Same happens on MARK target.

The latest -git kernel includes compatibility functions for
32 bit
userspace. You need to compile your iptables without the
KERNEL_64_USERSPACE_32 thing though (edit main Makefile).