- Adds creation of user chains via `-N <chainname>`
- Adds `-j RETURN` support for built-in chains, which triggers the
chain's underflow rule (usually the default policy).
- Adds tests for chain creation, default policies, and `-j RETURN' from
built-in chains.
This gets us closer to passing the iptables tests and opens up iptables
so it can be worked on by multiple people.
A few restrictions are enforced for security (i.e. we don't want to let
users write a bunch of iptables rules and then just not enforce them):
- Only the filter table is writable.
- Only ACCEPT rules with no matching criteria can be added.
Nayana Bidari
Kevin Krakauer
gVisor bot