Kernels higher than 2.6.10 don't support multiple --to arguments in
DNAT and SNAT targets. At present, the error is somewhat vague:
# iptables -t nat -A foo -j SNAT --to 1.2.3.4 --to 2.3.4.5
iptables: Invalid argument
But if we want current iptables to work with kernels <= 2.6.10, we
cannot simply disallow this in all cases.
So the below patch adds kernel version checking to iptables, and
utilizes it in [DS]NAT. Now, users will see a more informative error:
# iptables -t nat -A foo -j SNAT --to 1.2.3.4 --to 2.3.4.5
iptables v1.3.3: Multiple --to-source not supported
This generic infrastructure (shamelessly lifted from procps btw) may
come in handy in the future for other changes.
This fixes bugzilla #367. (Phil Oester)
4 files changed