Error configuring NAT with nftables

Error configuring NAT with nftables

[Pavel Volkov]

I've used nftables to perform filtering for a while and today I tried to 
configure it for NAT.

I took the example from nftables wiki [1]:
% nft add table nat
% nft add chain nat prerouting { type nat hook prerouting priority 0 \; }
% nft add chain nat postrouting { type nat hook postrouting priority 0 \; }

The first command completes fine, but the second gives me an error:
# nft add chain nat prerouting { type nat hook prerouting priority 0 \; }
<cmdline>:1:1-66: Error: Could not process rule: No such file or directory
add chain nat prerouting { type nat hook prerouting priority 0 ; }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Also tried this way:
# nft -f /etc/nftables/ipv4-nat 
/etc/nftables/ipv4-nat:3:1-2: Error: Could not process rule: No such file 
or directory
table nat {
^^
/etc/nftables/ipv4-nat:3:1-2: Error: Could not process rule: No such file 
or directory
table nat {
^^

I'm using nftables 0.3 with kernel 3.16.3. Can you help me with it?


[1] 
http://wiki.nftables.org/wiki-nftables/index.php/Performing_Network_Address_Translation_%28NAT%29

Re: Error configuring NAT with nftables

[Pablo Neira Ayuso]

On Tue, Sep 23, 2014 at 09:35:38PM +0400, Pavel Volkov wrote:
> I've used nftables to perform filtering for a while and today I
> tried to configure it for NAT.
> 
> I took the example from nftables wiki [1]:
> % nft add table nat
> % nft add chain nat prerouting { type nat hook prerouting priority 0 \; }
> % nft add chain nat postrouting { type nat hook postrouting priority 0 \; }
> 
> The first command completes fine, but the second gives me an error:
> # nft add chain nat prerouting { type nat hook prerouting priority 0 \; }
> <cmdline>:1:1-66: Error: Could not process rule: No such file or directory
> add chain nat prerouting { type nat hook prerouting priority 0 ; }
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> Also tried this way:
> # nft -f /etc/nftables/ipv4-nat /etc/nftables/ipv4-nat:3:1-2: Error:
> Could not process rule: No such file or directory
> table nat {
> ^^
> /etc/nftables/ipv4-nat:3:1-2: Error: Could not process rule: No such
> file or directory
> table nat {
> ^^
> 
> I'm using nftables 0.3 with kernel 3.16.3. Can you help me with it?

Does your .config contain:

CONFIG_NFT_CHAIN_NAT_IPV4=m

# lsmod | grep nft_chain_nat_ipv4
nft_chain_nat_ipv4     12684  2

Re: Error configuring NAT with nftables

[Pavel Volkov]

On Tuesday, September 23, 2014 10:31:31 PM MSK, Pablo Neira Ayuso wrote:
> Does your .config contain:
>
> CONFIG_NFT_CHAIN_NAT_IPV4=m
>
> # lsmod | grep nft_chain_nat_ipv4
> nft_chain_nat_ipv4     12684  2

You're right, this is what I missed. Thank you.
I hope the error messages will look more meaningful in the future :)