nftables compatibility (linux kernel 3.13 +)

[Jamin7777]

"Chain already exists" errors on newer kernels seem to cause connections to drop. A second reload of the ruleset applies it without errors (always).

A possible solution has been added to this thread by cbastos

https://sourceforge.net/p/fwbuilder/discussion/16372/thread/d06b6ae9/

Are there other incompatibilities with nftables?

[a-schild]

In the Uninett@be15f6e fork of fwbuilder they added a >=1.4.20 iptable version and then handle som especial cases for the undelying nftables

[carlxvier]

@Jamin7777
A possible solution has been added to this thread by cbastos

https://sourceforge.net/p/fwbuilder/discussion/16372/thread/d06b6ae9/

When I posted that possible fix at the Sourceforge I didn't knew about the fix applied to the reset iptables on this fork because of a possible deadlock condition.

I edited the old script that was giving the errors and set the loop like the one available here https://github.com/sirius/fwbuilder/blob/master/src/res/configlets/linux24/reset_iptables
and the chains got cleaned and erased.

[sirius]

@carlxvier Does the bug exist in current HEAD (sirius/fwbuilder@2dd4903)?

Does be15f6e and ecc886a fix the bug?