ruleset: add prerouting chain includes

[brada4]

Add missing includes around prerouting chain
Used by eg transparent proxies.
Spotted by @reinerotto
Add another missing in raw_prerouting

[em-may]

I could really use this for increasing the TTL of SSDP packets. Currently I'm using ruleset-post, but that's not ideal. If this could get merged in and updated in the repo that'd be great.

[brada4]

You can add includes in /etc/nftables.d/ with +/-1 priority, that is saved over sysupgrade. There is even example in that directory

[em-may]

I already have some in /usr/share/nftables.d/{ruleset-pre,table-pre,chain-pre/forward,ruleset-post}/, but as far as I can tell I can't add anything in /usr/share/nftables.d/chain-post/prerouting since there are no includes for that chain, thus this PR, right? So for the prerouting rules I need, I end up putting them in /usr/share/nftables.d/ruleset-post like

add rule inet fw4 prerouting <rule>

If I'm missing something, please lmk, thanks!

[brada4]

Too abstract to say yes or no.

[brada4]

something like

chain abcd {
 type filter ; hook prerouting priority raw + 1;
 //ttl hl set
}

those includes are inside table inet fw4{}, ie dont need table definition.