[Libwebsockets] v1.7.1

Andrejs Hanins andrejs.hanins at ubnt.com
Wed Feb 24 19:30:47 CET 2016



On 02/24/2016 07:22 PM, Andrejs Hanins wrote:
>
> On 02/24/2016 06:33 PM, Andy Green wrote:
>>
>> On 02/24/2016 11:08 PM, Andrejs Hanins wrote:
>>
>>
>>> Hmm, now I'm thinking again. When lws_close_free_wsi is called with
>>> reason=LWS_CLOSE_STATUS_NOSTATUS_CONTEXT_DESTROY, early jump to label
>>> just_kill_connection is made _before_ state value is copied into
>>> state_pre_close. So the check for wsi->state_pre_close == LWSS_HTTP
>>> is true just because default value of state_pre_close is zero. It is
>>> not a non-upgraded connection as written in the commit comment.
>>>
>>> Even more strange is that when I tried to move state_pre_close
>>> initialization to be done before jumping to just_kill_connection and
>>> removing those two new lines which check for LWSS_HTTP, then lws
>>> library crashes in various places.
>>>
>>> Andy, what do you think about it?
>> Can you give me a way to reproduce it with the test apps +/- a hack?
> Ok, so for the missing CLOSE callback on context destroy it is pretty easy - just add usleep(1000);
> after lws_service(context, 500); in test-client.c code. Then run test-client and immediately terminate it
> after connection with server is established - there will be no CLOSED callback without latest fixes.
>
> As for the crash - I can't reproduce it yet with test-client and test-server.
The crash was due to my changes. I allowed CLOSED callback to be called when
state_pre_close == LWSS_SHUTDOWN which doesn't account transient modes which
doesn't have user space data, so it crashed while I was accessing zero pointer, so no need
to worry.

So the only questions remains - is it normal that state_pre_close is not initialized to state
value if reason is LWS_CLOSE_STATUS_NOSTATUS_CONTEXT_DESTROY.
>
>> -Andy




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