Delete state, Reject & Block rules work perfectly fine
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But wouldnt it be great if the script actually took all states with either DST or SRC and killed every last one of them when you pressed apply when you change the rule?
I think thats what we actually want to happen when doing so.
Everyone knows deleting/changing rules doesn't kill existing states. Not a bug.
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It doesn't do that. That would be a new feature request, not a bug.
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i don't think i would want it to kill related states when creating a new rule …. this "feature' has saved me a couple of times when i did something stupid. (not locking myself out when i made a typo)
anyhow, i prefer to clear the states myself
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Summary is my guess is this is something specific to ICMP and as long as any related ICMP state still exists, it'll continue to let "new States" to be created.
Its not just ICMP, HTTPS which I have tested with the long youtube film that ran for over 2hrs 20mins despite various rules was also affected. As its WAN states that need to be deleted the recent change to unbound/ DNS resolver ie the change to the DNS service also means lots of WAN states kept open which means lots of firewall rules wont be updated. I've got over 2000 wan states open to various name servers since I started this thread all of a sudden and my CPU load has gone up to just under 50% load which will further prevent any rule changes from working properly unless I reset all states.
Everyone knows deleting/changing rules doesn't kill existing states. Not a bug.
I didnt and I dont see any mention of deleting states in numerous online blogs detailing how to do XYZ, nor is it in the pfsense book and I dont see it mentioned often in the forums either. So whether "everyone" knows is a matter of opinion.
With ISA server we used to just restart the service which had the same effect of deleting the states, but if anything the Apply Changes button in the pfsense gui is a little misleading imo.
I will say that in the Reset States webpage in the gui, there is some text which says it may be neccessary to reset the states so if anything that text could also be reiterated on the rules webpage for safety sake although not my preferred option which is below.
i don't think i would want it to kill related states when creating a new rule …. this "feature' has saved me a couple of times when i did something stupid. (not locking myself out when i made a typo)
anyhow, i prefer to clear the states myself
A new rule perhaps, but if you change an existing rule or even simply disable/enable an existing rule what then? Jump through some more hoops just to get the change to work, not everyone gets to charge by the hour.
And what if you have hundreds or thousands of states to delete one by one, it could be a never ending process because as you delete one state another could pop up from another device when a network and various devices have all been compromised with malware, ergo you never get to delete ALL the states so the new rules can never take effect.
So this leads you to one course of action, resetting all states in one go, which then renders the argument for a new rule perhaps mute point.
I've done similar but with multiple windows programs that check for the existence of each other, if one is not running, one of the running apps fires it up, if its been deleted it restores it, so not only can you not stop the various apps from running you cant even delete them, a similar technique is used with malware & viruses which you may or may not have had the pleasure of trying to fix for customers.
Besides there is also the point of inconsistent behaviour, why does deleting outward bound states not work, but deleting inbound states does work?
Inconsistent behaviour and misleading wording is the undoing of any good system.
But wouldnt it be great if the script actually took all states with either DST or SRC and killed every last one of them when you pressed apply when you change the rule?
I think thats what we actually want to happen when doing so.
It doesn't do that. That would be a new feature request, not a bug.
How about this for a feature request. Two or three buttons that pop up when a rule change has occurred which can be:
1. Apply Changes - No State changes
2. Apply Changes - reset only affected states
3. Apply Changes - reset all states.I would suggest it would be easiest and quickest to do buttons 1 & 3 for now because the code already exists in the existing Apply Changes button and the same for Reset Button in Diagnostics:Show States, Reset States tab so I doubt it would be too time consuming or difficult to merge the code together.
At least this way the gui becomes a reminder for breaking old habits and improves the experience for novice users who want to use pfsense in anger. I know CLI's have their fans, but Apple havent got to where they are to day by ignoring the gui experience.
I still havent got to the bottom of where this problem stems from though, as its been confirmed in OPNsense we still dont know if this is restricted to freebsd or a package used by freebsd which means other firewalls in other OS which use the package have this "backdoor" weakness, but might explain why the NSA were recommending opensource firewalls a while back if they have had their grubby mits over some code in advance.
Edit.
One other thought, is if the rules are only reset when the inward bound wan state is deleted, what if you are using an OPTx for an additional internet connection?
Do deleting the states not work for those interfaces as this appears to be the case currently when deleting outward bound states on OPTx interfaces. This could potentially be a bigger headache still unless all states are reset after every rule change. -
Summary is my guess is this is something specific to ICMP and as long as any related ICMP state still exists, it'll continue to let "new States" to be created.
Its not just ICMP, HTTPS which I have tested with the long youtube film that ran for over 2hrs 20mins despite various rules was also affected. As its WAN states that need to be deleted the recent change to unbound/ DNS resolver ie the change to the DNS service also means lots of WAN states kept open which means lots of firewall rules wont be updated. I've got over 2000 wan states open to various name servers since I started this thread all of a sudden and my CPU load has gone up to just under 50% load which will further prevent any rule changes from working properly unless I reset all states.
The original discussion was about how the block rule was not taking effect and allowing new ICMP states. Now that the discussion is changing into "how to kill existing states for a block rule", the topic has changed.
I think they already have a script for this and use it for scheduled rules. Maybe we just need a "kill all states" button under the edit window screen, allowing you to kill existing states for the current rule.
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Its simple. When changing one specific rule, all states for that rule should be killed. On all interfaces.
Only way the integrity of the firewall is kept.
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I didnt and I dont see any mention of deleting states in numerous online blogs detailing how to do XYZ, nor is it in the pfsense book and I dont see it mentioned often in the forums either. So whether "everyone" knows is a matter of opinion.
https://doc.pfsense.org/index.php/Firewall_Rule_Troubleshooting#Dangling_States
"Did you clear your states?" is asked like 5000 times a week here.
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Thats really nice if you run a production scenario and altering 1 rule blows the connection to the rest….
Including one self in a remote datacenter....! :-[
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Exactly why states should not be automatically cleared.
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I still havent got to the bottom of where this problem stems from though
what problem?
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They should….for that specific rule and not the entire state tale ;)
Exactly why states should not be automatically cleared.
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Submit a feature request. It's not a bug.
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I didnt and I dont see any mention of deleting states in numerous online blogs detailing how to do XYZ, nor is it in the pfsense book and I dont see it mentioned often in the forums either. So whether "everyone" knows is a matter of opinion.
https://doc.pfsense.org/index.php/Firewall_Rule_Troubleshooting#Dangling_States
"Did you clear your states?" is asked like 5000 times a week here.
That appears to be the only reference, besides do you know how many references there are to the phrase "Dangling State" in the forums?
Answer is here. http://bfy.tw/6mC
The quick answer is 0 (thats zero) reference to Dangling States in the forums and its certainly not mentioned in many many online how to's in websites & blogs. Thats alot of pfsense firewalls and others out there which can easily be compromised when combined with other methods to gain control of systems & networks.
Its also interesting there is only one link to this page which is here,
https://doc.pfsense.org/index.php/Special:WhatLinksHere/Firewall_Rule_TroubleshootingQuite why you feel the need to exaggerate the fact its refered to 5000 times, I can only go and consult the handbook here: http://pastebin.com/irj4Fyd5
It seems to me the significance of a Dangling State is not recognised or being played down.
The first mention of it captured by the Wayback Machine was on Sun May 17 2009
http://web.archive.org/web/20090501000000*/https://doc.pfsense.org/index.php/Firewall_Rule_TroubleshootingIt seems this problem exists in all versions of pfsense going back to 1.x which explains alot regarding how many times I have been hacked since I started using pfsense 1.2
I think they already have a script for this and use it for scheduled rules. Maybe we just need a "kill all states" button under the edit window screen, allowing you to kill existing states for the current rule.
Heres a test scenario you can do where the scheduled rules dont work which is probably best explained now as a "dangling state" as mentioned by Derelict, but is where the Inward bound wan states are not killed off.
Create your normal rules, in my example I have a Pass everything out rule.
FIrewall:Schedules webpage, Create a schedule that will take place in the future. For now I used 1st June (today), and set the time window for 15mins so if the time was 7am, the schedule would be 07:15 to 07:30.
Firewall:Rules web page select the right interface if you have more than Wan & Lan, and just above your Pass everything out rule create a new rule which Blocks everything out, scroll to the bottom of the edit rule webpage & click the Schedule button and select your time schedule from the drop down.
Save and apply changes.Now go watch a long free youtube video that will run for a few hours.
By now it should be getting closer to 07:15 the time at which the Block Everything rule will kick in.Find out what the ip address is from the interface with the Pass Everything and find out what IP address the youtube stream is coming from, once you have that go to the Diagnostic:States window and look up the youtube IP address, you should see two entries for both directions and they should both say Established : Established, if you have the traffic graphs for the interfaces on your dashboard you should also see the youtube traffic coming In on the Wan and Out on the interface where the device playing the youtube video is playing.
At 07:15am you will see in Firewall:Rules the Block Everything rule has become active as the icon in the Schedule column goes from a greyed out icon to a bold coloured icon indicating its gone from disabled to active. Likewise you can also visit the Firewall:Schedules webpage and see a clock icon next to the 07:15am to 07:30 time span. If you visit the Status: System Log: Firewall webpage, select Firewall tab and then Normal tab and filter on the interface by typing in Lan or whatever your interface is called before clicking the Filter button, any newly established traffic going out will be blocked by your now inforce Block Everything rule, whilst the already established youtube stream carries on unhindered.
You can verify the youtube stream is still active by continuing to watch the film or visit the Diagnostics: States webpage and look up the IP address of the youtube server streaming the film to you that you previously found and see the two states are still present, they maybe in a different location in the list but as long as they both have Established : Established in the state column then the "Dangling State" is letting the traffic through as it will for any malware or virus that is currently in your system and has established a connection with the outside world.
Exactly why states should not be automatically cleared.
Submit a feature request. It's not a bug.
IMO "Dangling States" are a bug as it makes it easy for bad actors & bad programs to get in and out of your system. Another way to look at this is, by asking this question, when is a firewall not a firewall? When it cant clear states down according the rules and/or by the schedules set up.
The fact its mentioned in the docs does not legitimise the problem, it simply acknowledges the problem exists.
The question is, can the dangling states be fixed?
However considering this goes back to pfsense 1.x I can no longer consider pfsense a firewall due to this Dangling State bug, so how many users have been duped and forked out money for something that it isnt?
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Still not a bug. Maybe it could best be described as a limitation. A well-known one at that. You should probably move on to that free firewall that's better than pfSense.
Yes, it would be nice if schedule triggers cleared states for just that rule. Submit a feature request.
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See:
https://forum.pfsense.org/index.php?topic=93336.23
intuitively I would call this behaviour a bug.
I may cite you, Derelict:
" Re: Firewall: Scheduling block game console
« Reply #4 on: May 04, 2015, 02:49:18 am »And all your ssh and other persistent sessions go with it. Yuck."
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They work fine. Like everywhere else, when you set a rule it doesn't affect existing states and they have to be cleared either organically or by force.
Feature request.
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Thats cool man!
Schedule rules doesnt really work if they are actually beeing used :D
Mikrotik here I come :D
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Mikrotik here I come :D
I thought you switched to OPNsense recently…
P.S. Schedule rules do work just fine - the allow ones. (I for one certainly do not want to kill everyone's working connections just because I have been playing with some rules. If desired, I can do that manually once I am done with the work. Not e.g. 30 times in an hour...)
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What you want is pretty irrelevant.
What should happen when running a schedule is another thing and it doesnt work.
Its like captive portal. When the time is up, youre done. No matter what you are doing…
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Still not a bug. Maybe it could best be described as a limitation. A well-known one at that. You should probably move on to that free firewall that's better than pfSense.
Yes, it would be nice if schedule triggers cleared states for just that rule. Submit a feature request.
As this dangling state issue appears in the first instances of pfsense [edit]
it would appear to be an issue with the package bundled with FreeBSD called Packet FIlter which might also be known as the Berkeley Packet Filterhttps://en.wikipedia.org/wiki/Berkeley_Packet_Filter They are two different packages [edit]https://www.freebsd.org/cgi/man.cgi?query=pf&sektion=4&apropos=0&manpath=FreeBSD+10.1-RELEASE
So it would appear at this stage that any stateful firewall on xyzBSD both opensource or commercial has the bug unless specific measures have been taken to address the problem (which I have yet to see advertised in my searches), but the source of the problem still has not been identified [edit]
as it could implicate the Libpcap libraries IF Packet Filter is the same thing as the Berkeley Packet Filter.[edit]WRT to PF ported to other OS's the closest comparison could be considered NetFilter in Linux but is considered more complicated due to it working on sets of rules that work in chains unlike the top down match listing of PF, and Linux has a comparable problem called Dangling Sockets.
The situation is further not helped as Chemlud points out pfctl is broken in this thread
https://forum.pfsense.org/index.php?topic=93336.msg518298#msg518298No problem to me, as long as the -k worked properly, in the pre-2.2 era. But now I have to kill all states to make it really work. Dunno why. Always the states with
re1 tcp routerIP(localIP) -> remoteIP ESTABLISHED…
in the states tab survive the -k procedure.
That's not fair. :-(
Update: selective killing of states with option -k is broken, leaves a lot of states in place, as pointed out above. No way around kicking off all users by killing all their states.
Maybe identify the version where pfctl works at killing selective states would be a work around assuming bugs in the corresponding PF are not too compromising.
I thought you switched to OPNsense recently…
P.S. Schedule rules do work just fine - the allow ones. (I for one certainly do not want to kill everyone's working connections just because I have been playing with some rules. If desired, I can do that manually once I am done with the work. Not e.g. 30 times in an hour...)
It wouldnt make any difference as this problem goes back to early versions of xyzBSD including pfsense 1.x as mentioned above.
Whilst you may not want to kill off one or more peoples active connections, would you say the same if it were some malware/virus/botnet established connection?
I have to say, I'm shocked at the widespread acceptance and such long running measured in years of the Dangling States or Dangling Sockets issue/bugs, no wonder bad actors find it so easy to compromise systems.
I'm beginning to wonder if there is any firewall out there that is capable of performing as requested.
Likewise with what I have discovered above, we cant even expect ESF to fix the problems as its core xyzBSD code unless one or more in ESF also code at the OS/package level? Are there any ESF employees who can code the affected packages?
