New 502 Bad Gateway

luckman212 · Oct 13, 2017, 3:47 PM

Clicked on the link to read the latest post and got this…

joke? Lol. Happy Friday!

jimp · Oct 13, 2017, 3:55 PM

So far, I have not had a crash since I removed that section. Been 21 hours, and still running strong. Looks like jimp found the issue. Now the question is what does it effect and why is it in there.

If it works good on ZFS and not UFS, this also makes some sense, as the error didn't show up on 2.4.0 till it was updated to BSD 11.1 from 11.0. So something must have changed in the file system workings, and UFS doesn't like the file locking now that pfBlockerNG uses.

That's possible. It looks like it's trying to keep some stats about what was hit, but it's using a plain text file to do it. IMO that should be an sqlite database and not a plain text CSV file but not having looked at the rest of the related code I'm not sure what changing that would entail, or if anything absolutely relies on that being plain text. I've been told that bbcan is aware though and he's looking into it. That could also explain 502/php issues people have had in the past with the pfblocker widget.

BreeOge · Oct 13, 2017, 3:58 PM

I have a PM going with BBcan, I pointed him to our findings a few min ago..

I am just glad we seem to be narrowing this down.

luckman212 · Oct 13, 2017, 3:59 PM

Following this loosely, but I really appreciate your guys' diligence on tracking this down. Happy hunting

john_galt · Oct 13, 2017, 8:11 PM

I just reinstalled with 2.4.0-R. Went with ZFS this time. Restored config and reset pfBlockerNG.
I also set the tunable kern.ipc.soacceptqueue back to it's original value of 128. Have fingers
crossed.

I might add that reinstalling and restoring from a config file was one of the least painful things
I've done in a while. Well done pfSense team!!

Doug

ha11oga11o · Oct 14, 2017, 10:48 AM

Hello all,

i do have err 502 Bad Gateway also and i filtered log at mine unit with relevant data. It might be usefull

https://pastebin.com/et5HvbpT

Also, mine unit need 2-3 reboots in row to be able to access GUI. At same instance when i reboot it i refresh GUI page and it loads forever.

Kind regards.

BreeOge · Oct 14, 2017, 3:49 PM

@ha11oga11o:

Hello all,

i do have err 502 Bad Gateway also and i filtered log at mine unit with relevant data. It might be usefull

https://pastebin.com/et5HvbpT

Also, mine unit need 2-3 reboots in row to be able to access GUI. At same instance when i reboot it i refresh GUI page and it loads forever.

Kind regards.

you can SSH in and hit Ctrl-Z and then run /bin/tcsh this will give you a shell back.

Then you can run reboot from the console/SSH.

Currently you have 3 choices

1. Remove PFblocker till BBcan177 can get the effected coded fixed. He is working on it, so I wouldn't expect it will be that long.
2. Reinstall with the ZFS file system.
3. Keep rebooting till update comes out.

Also you can remove the affected code reported in this thread, it is a temp fix, and will affect the widget reporting. But it does allow it to run without issues.

BreeOge · Oct 14, 2017, 3:52 PM

I want to give a big thank you to all the pfSense Team that helped with this issue, and BBcan177. Me and everyone are very thankful for the time and effort you put in to help us figure out this issue.

john_galt · Oct 14, 2017, 5:56 PM

Here Here!

musicwizard · Oct 15, 2017, 11:07 AM

I have the same problem.

I run Pfblocker and Snort.

i did remove the code and it seemed to work, but after like 20 min or so i got the same problem again. So im looking to do a complete reinstall and put back a backup i made before i went to 2.4.0.

when i use the old kernel on 2.4.0 all is fine.

jimp · Oct 15, 2017, 1:32 PM

@Music:

I have the same problem.

I run Pfblocker and Snort.

i did remove the code and it seemed to work, but after like 20 min or so i got the same problem again. So im looking to do a complete reinstall and put back a backup i made before i went to 2.4.0.

when i use the old kernel on 2.4.0 all is fine.

Did you gather the information requested in https://forum.pfsense.org/index.php?topic=137103.msg753994#msg753994 when it was stopped? You may have been hitting a different issue entirely.

musicwizard · Oct 15, 2017, 1:48 PM

@jimp:

@Music:

I have the same problem.

I run Pfblocker and Snort.

i did remove the code and it seemed to work, but after like 20 min or so i got the same problem again. So im looking to do a complete reinstall and put back a backup i made before i went to 2.4.0.

when i use the old kernel on 2.4.0 all is fine.

Did you gather the information requested in https://forum.pfsense.org/index.php?topic=137103.msg753994#msg753994 when it was stopped? You may have been hitting a different issue entirely.

Funny thing is i did have the information in a txt file was still copying some information out of putty. And my cat stept on the power connector of my computer which is lying on the floor. so i lost that file. :(

So i just did a clean install and used the recover config and installed it on ZFS now. Only have pfblocker running atm and no problems yet.

belt9 · Oct 16, 2017, 4:13 AM

@BreeOge:

Currently you have 3 choices

1. Remove PFblocker till BBcan177 can get the effected coded fixed. He is working on it, so I wouldn't expect it will be that long.
2. Reinstall with the ZFS file system.
3. Keep rebooting till update comes out.

Just checking in as my system was unreachable and it looks like this is the culprit, I just updated to 2.4.0-RELEASE form a month old snapshot last night.

I'm not sure about #2 helping you, as I've got a ZFS raidz2 install and this still happened to me. I've disabled DNSBL until a fix comes out, BBCan177 is top notch. I'm sure the fix will be available shortly if it's at all feasible.

musicwizard · Oct 16, 2017, 4:47 AM

well since i have a clean reinstall if 2.4.0 with zfs and im running both Pfblocker and snort i haven't had a " lockup" of the webgui etc.

Uptime 15 Hours 14 Minutes 49 Seconds

Al tho i did get a few Updates from BBcan :) because im using the test/beta version.

It goes seem that 2.4.0 using more Cpu tho.

TheNarc · Oct 16, 2017, 3:00 PM

With respect to the workaround that involves editing /usr/local/www/pfblockerng/www/index.php, I am not a PHP programmer, so I may be speaking out of turn, but I noticed that in the relevant code section two locks are acquired and never released:


        if (!empty($pfb_query)) {
	// Increment DNSBL Alias Counter
	$dnsbl_info = '/var/db/pfblockerng/dnsbl_info';
	if (($handle = @fopen("{$dnsbl_info}", 'r')) !== FALSE) {
		flock($handle, LOCK_EX);
		$pfb_output = @fopen("{$dnsbl_info}.bk", 'w');
		flock($pfb_output, LOCK_EX);

		// Find line with corresponding DNSBL Aliasname
		while (($line = @fgetcsv($handle)) !== FALSE) {
			if ($line[0] == $pfb_query) {
				$line[3] += 1;
			}
			@fputcsv($pfb_output, $line);
		}

		@fclose($pfb_output);
		@fclose($handle);
		@rename("{$dnsbl_info}.bk", "{$dnsbl_info}");
	}
}

Referring to the PHP documentation for the flock function, apparently this used to be okay because the locks were implicitly released when the file handles were closed, but that is no longer so starting from version 5.3.2: https://secure.php.net/manual/en/function.flock.php

That said, I don't know if the update from 2.3.4 to 2.4.0 happened to jump from a pre-5.3.2 version of PHP to a post-5.3.2 version. But regardless, I assume that explicitly releasing locks couldn't hurt anything. Also, the return value of one of the two fopen calls is checked but the other is not. I'm going to try the following modification on my system, which is still UFS, and will report back:


if (!empty($pfb_query)) {
	// Increment DNSBL Alias Counter
	$dnsbl_info = '/var/db/pfblockerng/dnsbl_info';
	if (($handle = @fopen("{$dnsbl_info}", 'r')) !== FALSE) {
		if(flock($handle, LOCK_EX)) {
         if (($pfb_output = @fopen("{$dnsbl_info}.bk", 'w')) !== FALSE) {
            if(flock($pfb_output, LOCK_EX)) {
               // Find line with corresponding DNSBL Aliasname
               while (($line = @fgetcsv($handle)) !== FALSE) {
                  if ($line[0] == $pfb_query) {
                     $line[3] += 1;
                  }
                  @fputcsv($pfb_output, $line);
               }
               flock($pfb_output, LOCK_UN);
            }
            @fclose($pfb_output);
         }
         flock($handle, LOCK_UN);
        }
	@fclose($handle);
	@rename("{$dnsbl_info}.bk", "{$dnsbl_info}");
	}
}

And sorry for the lousy formatting; I tried pasting several times and couldn't manage to get the indentation non-wonky.

TheNarc · Oct 16, 2017, 4:29 PM

It looks like pfSense has been using PHP 5.3.2 since around version 2.1 (the change log for 2.1 https://doc.pfsense.org/index.php/2.1_New_Features_and_Changes just says "PHP to 5.3.x"). So technically as far back as then all locks acquired with PHP's flock should have been manually released. Nevertheless, maybe some other change in 2.4.0 resulted in the lack of these explicit releases causing trouble where they had not before. I have two pfSense machines running 2.4.0 with pfBlockerNG and my modification now so I'll just see how they fare.

strigona · Oct 16, 2017, 4:45 PM

@TheNarc:

It looks like pfSense has been using PHP 5.3.2 since around version 2.1 (the change log for 2.1 https://doc.pfsense.org/index.php/2.1_New_Features_and_Changes just says "PHP to 5.3.x"). So technically as far back as then all locks acquired with PHP's flock should have been manually released. Nevertheless, maybe some other change in 2.4.0 resulted in the lack of these explicit releases causing trouble where they had not before. I have two pfSense machines running 2.4.0 with pfBlockerNG and my modification now so I'll just see how they fare.

You are correct. I just ran 'php -v' on my 2.3.4 system:

PHP 5.6.31 (cli) (built: Jul 14 2017 19:45:37)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies
    with Xdebug v2.5.0, Copyright (c) 2002-2016, by Derick Rethans
    with Suhosin v0.9.38, Copyright (c) 2007-2015, by SektionEins GmbH

BreeOge · Oct 16, 2017, 7:12 PM

BBcan177 is currently working on an update to move this to a sqlite database, and get it off the text file. So this should never be an issue in the future.

All the effected code does is keep the updates for the desktop widget. Omitting the code does not break pfBlockerNG it only affects the widget reporting.

Steve_B · Oct 17, 2017, 10:12 PM

I pushed some experimental changes today that are designed to help track down the issue of gateway timeouts occurring when the IPSec dashboard widget is displayed. Those changes will be in the next 2.4 snapshot (probably early Oct 18th)

I would appreciate any feedback Better/worse/no change . .

Thanks

Xentrk · Oct 18, 2017, 6:06 AM

I also get the 502 Bad Gateway error when trying to access the pfSense Web GUI. I can logon a SSH session. But it hangs after entering my password. I noticed it about 24 hours after upgrade to 2.4. I use pfBlockerNG. Thanks for the information in this thread. I will continue to monitor for updates to the issue.