Hi Adolph,
On 29/02/2024 11:37, Adolf Belka wrote:
Hi Nick,
On 28/02/2024 15:39, Nick Howitt wrote:
Hi,
I posted this to the forums but this may be a better place for discussion.
I am a new user of IPFire had have just transitioned from ClearOS which is going end of life this year and I believe some of the firewalling could be a lot easier. Full disclosure - I used to be a basic maintainer of ClearOS (and sole maintainer for about 20 months) and I have good understanding of iptables.
Welcome to the IPFire dev mailing list. You will be most welcome to utilise your coding skills to support the IPFire project. There are lots of bugs in the IPFire Bugzilla that would benefit from additional resources becoming available.
I don't have much in the way of coding skills. I can script in bash. I was able to maintain some php in ClearOS but could never originate a new app and I have not used any IDE for code generation or debugging, I am afraid.
I have found the firewall complicated to use as it is trying to do everything in one screen and I can only really get it to work with my knowledge of iptables and using the help screens. It is not something any family member could easily take over if I ever pass on.
I have to say that my experience was different from yourself. I have no experience with iptables, I am just a hobbyist in terms of coding etc.
I just read through the wiki pages on the firewall and then entered the info I needed into the firewall rule page and so far all of the rules I have created have worked as expected.
When forwarding an alias, there is no mention anywhere of probably needing an outbound SNAT rule or hairpin rule and the Firewall screen specifically blocks you from creating a hairpin rule.
Many domestic routers have a very simple Port Forwarding menu. At its simplest, it has a destination (LAN) IP, protocol and port/port range which applies to the external interface. ClearOS also allows you to switch ports, so, for example incoming tcp:2222 can be switched to tcp:22. There is no mention of NAT, of source ports (which are irrelevant) or interfaces. It would greatly help unknowledgeable users to have a simple port forwarding menu something like that, with maybe a source IP field as well.
Trying to understand what is meant by the simplification description in words and its impact on the existing approach can be difficult.
Surely this screen is simpler:
But it does not allow for port redirection or enable you to specify a source IP which seems to be quite important for SIP users.
If there is a Port Forwarding menu, what about when users need to create pinholes between the zones, which is not a Port Forward rule. How would that be dealt with in this menu or would there have to be another separate menu for that?
I have no problem with multiple menus, each with a different purpose
What happens with the Incoming and Outgoing Firewall firewall Rule generation? Is that another menu or how is that dealt with. Having different menus for each type of rule generation sounds to me like it is getting more complicated rather than simpler.
I have no problem with multiple menus, each with a different purpose, but each simplified menu should create all the rules it needs, so a port forward creates Forward and DNAT rules and, arguably a hairpin rule. If you are forwarding, so using an alias, the screen used for that creates the alias, Forward, DNAT, SNAT (back to the external IP) and the hairpin rule all from one screen. Currently you have to configure 3 firewall rules (including the hairpin) and one alias. I am saying one screen to do it all would be simpler.
An approach could be for you to create a patch set for the simplification that you are considering. That would enable you to show what is being proposed and the potential impact for existing users that are familiar with the current approach.
I am not really a coder and haven't a clue how to design a screen or any real idea how the whole system links together.
It would also give you the opportunity to familiarise yourself with the IPFire patch submission process.
I have a /29 block of static IP’s, Really using one of them should need a screen little more complicated than a Port Forwarding screen, but should also allow you to specify which of your external IPs to use. Then it should set up the Alias for you and do the port forwarding with the option of any protocol. At the same time it should set up an SNAT rule so outbound traffic is seen to originate from your designated external IP rather than the default interface IP, and a hairpin rule should be set up so the external IP can be accessed from the LAN (it is only needed for the LAN that the target device is on and not the other LANs).
As you have in ClearOS, you could then have a separate menu to open the incoming firewall e.g. for OpenVPN.
The incoming rules for OpenVPN are automatically created if OpenVPN is used. If you create an OpenVPN RW connection then it can be used without needing any additional rules defined. If you want to limit the access of the RW to certain machines on the green network then additional rules would have to be created dependent on the requirements.
You have missed the point. I was using OpenVPN as a specific example, but I meant for any service running in IPFire which you wanted to expose to the internet, e.g Nginx, HAProxy, a public time server etc. In iptables terms, the difference between the INPUT chain and the FORWARD chain. I would separate them out into different screens.
I like the Service groups concept but, at the same time, it could be made largely redundant. If the use of “-m multiport” is made use of for all port based rules, including a single port, then the destination port selector in the Protocol section could be opened up to allow up to 15 ports to be specified, like you can in the Services section. Then I think service groups are only relevant for when you have more than 1 protocol that you want to apply the rule to.
Yes the service groups are when you want to apply a rule to a collection of ports. Examples could be having a rule that allows both http and https access to a web server, allowing both udp and tcp traffic to a qbitorrent server etc.
What would be the benefit for the users of changing the Service Groups option on the Firewall Groups menu to using a drop down box on the Firewall Rule page.
No that is not what I meant. If the "-m multiport" option is always used when generating port based rules, then the validation on the Destination Port box can be opened up to allow things like "80,443,9881:9884,9981:9984". Currently it will only accept a single port or port range. This would remove the need for Service Groups if it is for a single protocol avoiding having to use another menu, which could be for advanced usage only. So no moving of the dropdown, but changing the validation on the Destination Port box and changing the resulting firewall rules generated to use the multiport module always. If you use service Groups, the multiport module gets used anyway.
If it just does the same thing but in a different location then I would suggest leaving it as it is as users will already be familiar with where to go for that function.
You can leave Service Groups. Advanced users will appreciate them, but less advanced users will get more power and not be pushed into having to configure a separate menu as well.
Regards,
Adolf
I would also need to think about it more, but it may be good if Static Routes also created their own hairpin firewall rule.
Regards,
Nick
