[SOLVED ]Squid 0.4.44_25 / assertion failed: http.cc:1533: "!Comm::MonitorsRead(serverConnection->fd)

[CaliPilot]

Well this was a real challenge but finally we solved it. We asked Netgate Support (Enterprise) for assistance and those guys were pretty responsive but in the end, we were on our own to make this thing work. They checked our setup, found no issues and told us to wait for the next update of Squid.

We've installed a new box with PFsense and made almost everything from scratch, except for the users and certificates (which was on it's own a *itch to complete) which we restored from the old box.

And a few minutes were were back on, oh heck, we had the same crashes, was pretty close to start working is a butcher or gardener.

The logs were full with errors like... Tons of it...

1591073788.173 0 10.41.49.28 NONE/409 4015 CONNECT init.itunes.apple.com:443 - HIER_NONE/- text/html
1591073788.173 0 10.41.49.28 NONE/000 0 NONE error:transaction-end-before-headers - HIER_NONE/- -
1591073788.188 0 10.41.49.28 NONE/200 0 CONNECT 104.125.6.88:443 - HIER_NONE/- -
1591073788.188 0 10.41.49.28 NONE/409 4015 CONNECT init.itunes.apple.com:443 - HIER_NONE/- text/html
1591073788.188 0 10.41.49.28 NONE/000 0 NONE error:transaction-end-before-headers - HIER_NONE/- -

We stopped HTTPS/SSL Intercetion and I was pretty close to forget it but it kept my up all night and I started digging in the mud. After looking for the "NONE/409"-errors I found in the Netgate Docs the remarks about DNS which lead us to rest and in the end we got this baby, more or less, pretty smooth up and running.

This is not fixing the existing Bug in Squid but changes the environment that it won't escalate to a way where Squid is crashing.

We had 3 issues:

1. DNS

2. DNS Resolver

3. Squid: ACL regexp errors & missing options

4. DNS (the most important thing)

We used Google DNS (8.8.8.8/8.8.4.4) and 2 other ones from OpenDNS before as our main Namesevers. We changed them to the ones from our ISP. If you have a lot of traffic to CDN-Providers this is key.

We have also 2 DNS-Servers within in our AD, we switched off DNS-Cache via the Registry, disabled all DNS-caching via GPO on the clients. The "do not cache" policy doesn't work well Win2k8R2 so we created a script and delete them via the scheduler every 5 minutes.

Both AD-DNS use now DNS-Resolver as forwarder. Make sure that DNS-Resolver and the AD-DNS-Servers are always sync and respond with the same IP-Addresses on Queries. Verify that your client has DNS-caching disabled and is resolving the same IP as your PFSense & AD-DNS.

2. DNS Resolver:

Make sure that DNS-Resolver is working and utilized by your internal DNS-Servers. Since CDNs are changing IP-Adresses almost every few minutes we set the "Minimum TT" to 43200, this value is maybe to high but we made a pretty good experience with it so far. Enable "DNS Query Forwarding" so your upstream DNS-Servers are used.

3. Squid

We used "Splice Whitelist, Bump otherwise" as MITM-Mode and had a bunch of domains listed in ACL/Whitelist area in the style like ".whatsapp.com". This almost never worked and when I took a look in the whitelist.acl-file it was empty. It was not really empty but all the lines starting with the . were not visible in vi. After we changes the domains to (^|.)whatsapp.com$ it looked like the files was much better working.

---

We are now in "Custom Mode" with the following config (added to Custom Options SSL/MITM):

acl DiscoverSNIHost at_step SslBump1
acl step1 at_step SslBump1

acl noSSLInterception ssl::server_name_regex (^|.)apple.com$
acl noSSLInterception ssl::server_name_regex (^|.)cdn-apple.com$
acl noSSLInterception ssl::server_name_regex (^|.)icloud.com$
acl noSSLInterception ssl::server_name_regex (^|.)icloud-content.com$
acl noSSLInterception ssl::server_name_regex (^|.)itunes.com$
acl noSSLInterception ssl::server_name_regex (^|.)mzstatic.com$
...
acl noSSLip dst xxx.123.xxx.96/32
acl noSSLip dst 149.xxx.xxx.0/22
acl noSSLip dst xxx.xxx.172.0/22
...
ssl_bump peek step1
ssl_bump splice noSSLInterception
ssl_bump splice noSSLip
ssl_bump peek DiscoverSNIHost
ssl_bump bump all

---

And in Custom Options (before auth)

client_persistent_connections off

Also add 127.0.0.1 to "use alternate DNS Servers for the Proxy Server". DNS-Resolver should respond on 127.0.01

Enable "Resolve DNS IPv4 first".

---

After those changes Squid is working almost as usual, the SSL-Errors are gone and our business gets no longer interrupted. Even the Apple-App store, Gotomeeting, Teams and Adobe-CC are working without flaws. Awesome.

It might not be the perfect setup but we are still do testing and improve the settings.

Chris

[CaliPilot]

Also:

if you are using SquidGuard, disable "Clean Advertising" when you PFsense-GUI is running on HTTPS. Squidguard is replacing advertisings with a pixel which is loaded from the PFsense box like "http://[IP of your box]/sgerror.php...

This breaks HTTPS and if your WEBif is running on a non-standard port nginx is reporting errors in your system log.

Chris

[viktor_g]

@CaliPilot said in [SOLVED ]Squid 0.4.44_25 / assertion failed: http.cc:1533: "!Comm::MonitorsRead(serverConnection->fd):

Squid

We used "Splice Whitelist, Bump otherwise" as MITM-Mode and had a bunch of domains listed in ACL/Whitelist area in the style like ".whatsapp.com". This almost never worked and when I took a look in the whitelist.acl-file it was empty. It was not really empty but all the lines starting with the . were not visible in vi. After we changes the domains to (^|.)whatsapp.com$ it looked like the files was much better working.

Thanks for the info, redmine issue created: https://redmine.pfsense.org/issues/10654

[viktor_g]

@CaliPilot said in [SOLVED ]Squid 0.4.44_25 / assertion failed: http.cc:1533: "!Comm::MonitorsRead(serverConnection->fd):

We used "Splice Whitelist, Bump otherwise" as MITM-Mode and had a bunch of domains listed in ACL/Whitelist area in the style like ".whatsapp.com". This almost never worked and when I took a look in the whitelist.acl-file it was empty. It was not really empty but all the lines starting with the . were not visible in vi. After we changes the domains to (^|.)whatsapp.com$ it looked like the files was much better working.

Fixed in the latest Squid pkg
Please update

[aGeekhere]

@CaliPilot
Not sure if you have already read through this but here it is
https://forum.netgate.com/topic/100342/guide-to-filtering-web-content-http-and-https-with-pfsense-2-3

to prevent these issue you need to use the following
WPAD (or manual set)
Transparent Proxy to catch http traffic the WPAD misses
SSL Man In the Middle Filtering SPLICE ALL catch https traffic the WPAD misses

[CaliPilot]

@aGeekhere Sorry for the late response. I have my setup now running for weeks without WPAD or anything like that and i have no issues. The key was to have solid DNS settings on PFsense, Windows DNS and on our clients and now it works like charm. Sometimes we see SSL-Errors on sites running on Akamai (or other CDNs) but only for a few minutes.

Chris

[mdalacu]

I have the same problem and it is driving me nuts. Every day when office hours begins, squid crashes with this error. On 2.4.4p3 suid was rock solid...:/
The only thing i could do from UI is to delete the cache and then squid starts, otherwise it will not start from services.
I have no DNS issues.

2020-07-31 08:46:56 [45559] loading dbfile /var/db/squidGuard/Misc/domains.db
2020-07-31 08:46:56 [45559] logfile not allowed in acl other than default
2020/07/31 09:02:56 kid1| assertion failed: http.cc:1533: "!Comm::MonitorsRead(serverConnection->fd)"
2020/07/31 09:02:56 kid1| Starting Squid Cache version 4.10 for amd64-portbld-freebsd11.3...
2020/07/31 09:02:56 kid1| Service Name: squid
2020-07-31 09:02:56 [53246] (squidGuard): can't write to logfile /var/log/squidGuard/squidGuard.log
2020-07-31 09:02:56 [53246] New setting: logdir: /var/squidGuard/log
2020-07-31 09:02:56 [53246] New setting: dbhome: /var/db/squidGuard
2020-07-31 09:02:56 [53246] init domainlist /var/db/squidGuard/blk_blacklists_ads/domains
2020-07-31 09:02:56 [53246] loading dbfile /var/db/squidGuard/blk_blacklists_ads/domains.db
2020-07-31 09:02:56 [53246] init urllist /var/db/squidGuard/blk_blacklists_ads/urls

Jul 31 09:02:56 	kernel 		pid 43401 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:02:57 	kernel 		pid 52412 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:02:58 	kernel 		pid 55101 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:02:59 	kernel 		pid 58638 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:03:00 	kernel 		pid 61188 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:03:01 	kernel 		pid 63750 (squid), jid 0, uid 100: exited on signal 6
Jul 31 09:03:17 	Squid_Alarm 	68674 	Squid has exited. Reconfiguring filter.
Jul 31 09:03:17 	Squid_Alarm 	68975 	Attempting restart...
Jul 31 09:03:20 	Squid_Alarm 	71372 	Reconfiguring filter...
Jul 31 09:03:20 	check_reload_status 		Reloading filter
Jul 31 09:03:22 	php-fpm 	28232 	/rc.filter_configure_sync: [squid] Installed but not started. Not installing 'nat' rules.
Jul 31 09:03:22 	php-fpm 	28232 	/rc.filter_configure_sync: [squid] Installed but not started. Not installing 'pfearly' rules.
Jul 31 09:03:22 	php-fpm 	28232 	/rc.filter_configure_sync: [squid] Installed but not started. Not installing 'filter' rules. 

Help please..

[vijay7]

@madalacu were you able to resolve this, I am started getting this issue, became a nightmare for me, please help

[mdalacu]

@vijay7 Try to update the squid package to the latest version and see...
For me the problem remains but squid threads are able to restart in the latest version.. so it is working...

[vijay7]

Tried that already, no difference, atleast twice a day squid service is stopping.

[tobyswe]

Hello all

This is absolutely NOT a solved problem. Someone should change this. I have several netgate devices with SQUID and SQUIDGARD installed. All of them has this problem. The SQUID service along with the SQUIDGARD service stops several times a day. I have been using SQUID /SQUIDGARD since 2015 . This problem started in 2019 after an upgrade. With the latest upgrade of Pfsense firmware and SQUID /SQUIDGARD it has become terrible. I have to manually start the services several times a day. For us using pfsense without SQUID is not an option and my staff is really questioning why we continue with netgate. The above solutions was not a solution for us. Its still the same.
The error message in SQUID logs
assertion failed: http.cc:1533: "!Comm::MonitorsRead(serverConnection->fd):
Does anyone has any idea of this. I would hate for the first time in a very long time to be forced to go to other routers.

/Toby

[mdalacu]

Again last week was terrible for me..same problem...i was gessing sites and blindly blacklisted them trying to solve this problem...it's a never ending storry.
Very very annoying and time consuming!

[viktor_g]

Can you test it on the latest 2.5 snapshot?

[vijay7]

Finally, i have moved to standalone squid proxy, and I am not getting any issues in standalone, but we have another machine running pfsense and squid, same in my case as well, our company is asking about this issue, don't know why everyday morning 9 AM squid will be down, I had to put someone in a day to continuously monitor because even the watchdog is not able to start this.

[viberua]

My Squid also start crashing.
In Friday 13 :) evening Squid and SquidGuard services stopped working.
When i tried to run it from services - webpages was opening, but after few seconds Squid services stopped again.
I have rebooted server, but no luck - after few seconds Squid stop working and pages don't load.
Then i disabled MITM and Squid falling is stopped.
We are using 2.4.5-RELEASE-p1 of Pfsense and 0.4.44_35 Squid with 1.16.18_9 SquidGuard.
Where/which logs i should check for find what cause this crashing?

[tobyswe]

Now this morning the problem is really bad. Several times SQUID is stopping. We did not have any other choice then reinstalling our old Fortigate and pay the licenses for the proxy. Anyone heard of a solution of this issue ?
Someone mentioned to test a 2.5 snapshot. Maybe a bit risky in a production environment

[viberua]

Today enabled MITM mode. After 2 hours Squid is stop working. Which logs check?

[aGeekhere]

Is this issue fixed yet?

[viktor_g]

watch https://redmine.pfsense.org/issues/10608

[viberua]

This post is deleted!