Hello Matthias,
in general I like the possibility to force the usage of the local DNS server by just redirecting all queries to it. This is way more elegant instead of blocking the requests to any nameservers by firewall rules, except the local unbound to force it's usage.
I reviewed your last patch and want to give you some thoughts - may the can help you:
Hi,
since restarting the *whole* firewall through '/etc/rc.d/init.d/firewall restart' as I did before is NOT an option, I'm thinking about another
simpler way - to do this.
As Michael wrote "There are plenty of temporary rules that are being created and which simply will get lost after restarting the firewall. Mainly this affects IPsec, but also QoS."
For me - and of course for everybody who uses IPSec or QoS - this is a showstopper. Saving the affected - temporary rules - is too complicated (for me). I'm trying to make this as simple as possible.
Yes, this is the reason, why reloading / restarting the whole firewall should be avoided if possible.
So I'm thinking about separating the DNS/NTP-commands and use them in a another init-file, apart from the firewall initscript. I just want to "go out of the way". ;-)
As I see it, IPSec and QoS (e.g) would not be affected and furthermore we would perhaps have the choice to control some other settings through this file. E.g., the settings from '/var/ipfire/optionsfw/settings' are processed in various control files, see: https://community.ipfire.org/t/forcing-all-dns-traffic-from-the-lan-to-the-f...
And perhaps that would give us the chance to tidy things up. Just a thought.
So what about using an 'optionsfw' initscript for the DNS/NTP rules?
This would be a possible solution, but ends in multiple files which are doing the same - dealing with firewall rules.
This is not very intuitive and hard to maintain.
This and *only* this file would be started through "Save and Restart' on 'optionsfw.cgi', using a new binary. As before, this would be 'optionsfwctrl(.c)', now just containing a call of '/etc/rc.d/init.d/optionsfw'. Controlling other settings could be added as needed. A complete firewall restart is NOT initiated.
In this init, the existence of the needed values is first checked, and only processed if they exist (e.g.): ... if [ -z "$DNS_FORCE_ON_GREEN" ] && [ "$DNS_FORCE_ON_GREEN" == "on" ]; then ...
The only affected chain is CUSTOMPREROUTING, so other functionalities/chains (IPSec, QoS) should not be affected.
Please do not use one of the CUSTOM firewall chains, they only should be used by the users to customize their systems.
I would suggest to use a new chain like "FORCEDREDIRECT" or similar before the CUSTOMPREROUTING chain.
This would have the advantage, that you safely can flush this chain and directly can insert you redirect rules for the network zones and desired the protocol. So you not need to check each time if the rule already exists.
This will speeds up the whole process and keeps the code clear.
Instead of writing an additional init script for adding the rules you directly can execute the iptables calls by your new optionsfw binary.
This allows you to easily call the binary from the CGI file and perform all required operations inside the single chain without touching anything else on the running firewall.
Best regards,
-Stefan
May I ask for your opinions? ;-)
Best, Matthias