Re: [PATCH] Fix session helper "crashing too rapidly"

 On Sun, 18 Sep 2011 21:05:35 +0100, Andrew Beverley wrote:
> Hi,
>
> I have run into a problem using the session helper (ext_session_acl).
> In
> its current format, the session helper expects 2 parameters as a
> minimum. However, using the example at
> http://wiki.squid-cache.org/ConfigExamples/Portal/Splash only one is
> passed (the IP address).
>
> The second parameter expected is referred to as the user_key in the
> source code, which is then returned as a prefix in the reply. When
> user_key is missing, ext_session_acl segfaults. When it *is* there,
> its
> presence in the reply message breaks the protocol (according to
> http://www.squid-cache.org/Doc/config/external_acl_type/ the reply
> should begin with "OK" or "ERR").
>
> The attached patch completely removes the user_key variable. It Works
> For Me (TM), but I do not know the original intention for user_key.
> Is
> it needed?
>
> I would also like to see any STDERR messages from the helper logged
> to
> cache.log (for example, if the database cannot be created). What is
> the
> best way to achieve this? I couldn't work out a way to do it - they
> appear to be "lost" at the moment.
>
> Thanks,
>
> Andy

 The session helper in Squid-3 is concurrent. The user_key is the opaque
 channel-ID. (Probably should be renamed to match the protocol
 documentation).
 http://wiki.squid-cache.org/Features/AddonHelpers#Access_Control_.28ACL.29

 The correct way to fix this is to detect the segfault case add a stderr
 ERROR: message that the helper is concurrent and requires a config
 update.

 stderr should appear in cache.log whenever sent. Most of the lines so
 far appear to be debug messages, which depend on the -d option to
 display.

 Also....the .8 manual needs to mention the concurrency rather than just
 implying it in the example config. The helper version should get a bump
 to 1.1 as well.

 Amos
Received on Sun Sep 18 2011 - 22:49:19 MDT