de913bbe65
Currently there are two iptables rules per port for each link: one to allow the parent to connect to the child's port, and another one to allow return traffic from the child back to the parent. The second rule shouldn't be needed because the "ctstate RELATED,ESTABLISHED" rule can already allow all established traffic. So this patch does the following: 1. Move the RELATED,ESTABLISHED rule to be _before_ the potential inter-container communication DROP rule so it will work for inter-container traffic as well. Since we're inserting, everything is reversed chronologically so it should be inserted _after_ we insert the DROP. This also has a small performance benefit because it will be processed earlier and it's generally one of the most commonly used rules. 2. Get rid of the unnecessary return traffic rule per link. 3. Also move the other "Accept all non-intercontainer outgoing packets" rule to earlier. This gives a small performance benefit since it's also a commonly used rule, and it makes sense to logically group it next to the ctstate rule. Docker-DCO-1.1-Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> (github: jpoimboe) Upstream-commit: 5c04f1bcc70e81fe3c93b1c246ce17a11304ad7f Component: engine