RE: [lwip-users] Re: TCP payload is doubled (Hans-Joerg)

[David Shmelzer]

Thanks Hans.
I was indeed calling tcp_recvd.
Problem was my TCP_WND == TCP_MSS.
I doubled TCP_WND and it now works.



-----Original Message-----
From: address@hidden
[mailto:address@hidden On Behalf Of HJ
Sent: Friday, October 16, 2009 5:08 PM
To: address@hidden
Subject: [lwip-users] Re: TCP payload is doubled (Hans-Joerg)


I guess my hint is not the solution of the problem, because you
mentioned, downgrading to 1.3.0 helped.
However I encountered exactly the same symptoms with the following flaw
in my application:
- I use the callback api
- According to rawapi.txt I should have called tcp_recvd for every
package but I missed to do it.
- When I called tcp_recvd, the problem disappeared (lwip version 1.2.0).

Despite this will not solve the problem, it will perhaps point in a
direction, if there is a bug in version 1.3.1.

Kind regards
Hans-Joerg



On Fri 16/10/09 18:00 , address@hidden wrote:

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> Today's Topics:
> 1. RE: TCP payload is doubled (David Shmelzer) 2. Re: 
> sys_arch_mbox_fetch (Fabian Koch) 3. SV: [lwip-users] TCP payload is 
> doubled (Jan Wester) 4. Re: sys_arch_mbox_fetch () 5. RE: TCP payload 
> is doubled (David Shmelzer)
> 
> ----------------------------------------------------------------------
> Message: 1
> Date: Thu, 15 Oct 2009 15:55:42 -0400
> From: "David Shmelzer" 
> Subject: RE: [lwip-users] TCP payload is doubled
> To: "Mailing list for lwIP users" 
> Message-ID:
> Content-Type: text/plain; charset="us-ascii"
> I did a wireshark capture and the window size from lwip keeps 
> decreasing by the packet length received by lwip for each transaction.

> When it finally decreases to less than the packet size my s/w hiccups 
> because it expects a full packet. So this problem exposed a flaw in my

> software. Is anyone else seeing teh window size decreasing?
> -----Original Message-----
> From: lwip-users-bounces+daves=
> [mailto:lwip-users-bounces+daves=] On Behalf Of Bill Auerbach
> Sent: Wednesday, October 14, 2009 8:13 AM
> To: 'Mailing list for lwIP users'
> Subject: RE: [lwip-users] TCP payload is doubled
> >Occasionally, the payload in my TCP return packet sent from lwip is
> 
> >more bytes than I'm expecting.
> >It looks like it may be concatenating two copies of the payload.
> Does this mean the data received by the application is bad or you're 
> just receiving more of it than you expected but it's all good?
> Bill
> _______________________________________________
> lwip-users mailing list
> http://lists.nongnu.org/mailman/listinfo/lwip-users
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> Message: 2
> Date: Fri, 16 Oct 2009 11:37:13 +0200
> From: Fabian Koch
> Subject: Re: [lwip-users] sys_arch_mbox_fetch
> To: Mailing list for lwIP users
> Message-ID:
> Content-Type: text/plain; charset="us-ascii"
> lwip-users-bounces+fabian.koch= wrote on 15.10.2009
> 16:30:58:
> > Your conservative approach is the right thing to do since
> basically,
> > what you are trying to do is not supported! Calling
> netconn_close()
> > while the connection waits in netconn_accept() means you are using
> one
> > netconn from two different threads, which is not supported.
> I have one Taks per netconn and I have an EventTask that relays 
> commands to these socket Tasks.
> When my main application tells all subsystems to shut down and free 
> their resources, the eventTask sends command_close to all socket 
> Tasks.
> This works good for all Tasks except the ones waiting in
> netconn_accept()
> because the tasks won't execute the close command.
> So I took the close command out of the socketTasks and close them 
> directly from the eventTask.
> So yes, I access one netconn from two different task - only in this 
> specific event.
> I'd be glad if you could give me any ideas on how to achieve this 
> behaviour in another way (and not setting recv_timeo and polling
> accept!)
> regards,
> Fabian
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> scrubbed...
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> achment.html------------------------------
> Message: 3
> Date: Fri, 16 Oct 2009 13:41:52 +0200
> From: "Jan Wester" 
> Subject: SV: [lwip-users] TCP payload is doubled
> To: "'Mailing list for lwIP users'" 
> Message-ID: 
> Content-Type: text/plain; charset="iso-8859-1"
> Hi
> I have the same problem
> Kieran mention about to set TCP_WND_UPDATE_THRESHOLD = 0. I have not 
> tested yet, will start to test next week Kieran wrote The window 
> advertisement code was re-worked in 1.3.1 to only send an explicit 
> update when the change in window is greater than 
> TCP_WND_UPDATE_THRESHOLD.  This defaults to (TCP_WND / 4). You could 
> define this to be zero to get the old behaviour, but the new behaviour

> should be much better.  I would be interested to know what the problem

> you encounter as a result of the less-frequent window updates is.  
> Note that any ACKs for data that get returned should have the 
> up-to-date window information in them
> - it is only the sending of explicit window update ACKs that is 
> restricted.
> /Jan
> -----Ursprungligt meddelande-----
> Fr
> [mailto:lwip-users-bounces+j.wester=] F
> Skickat: den 15 oktober 2009 21:56
> Till: Mailing list for lwIP users
> I did a wireshark capture and the window size from lwip keeps 
> decreasing by the packet length received by lwip for each transaction.

> When it finally decreases to less than the packet size my s/w hiccups 
> because it expects a full packet. So this problem exposed a flaw in my

> software. Is anyone else seeing teh window size decreasing?
> -----Original Message-----
> From: lwip-users-bounces+daves=
> [mailto:lwip-users-bounces+daves=] On Behalf Of Bill Auerbach
> Sent: Wednesday, October 14, 2009 8:13 AM
> To: 'Mailing list for lwIP users'
> Subject: RE: [lwip-users] TCP payload is doubled
> >Occasionally, the payload in my TCP return packet sent from lwip is
> 
> >more bytes than I'm expecting.
> >It looks like it may be concatenating two copies of the payload.
> Does this mean the data received by the application is bad or you're 
> just receiving more of it than you expected but it's all good?
> Bill
> _______________________________________________
> lwip-users mailing list
> http://lists.nongnu.org/mailman/listinfo/lwip-users
> ------------------------------
> Message: 4
> Date: Fri, 16 Oct 2009 13:45:59 +0200
> From: "" 
> Subject: Re: [lwip-users] sys_arch_mbox_fetch
> To: Mailing list for lwIP users
> Message-ID: 
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Fabian 
> Koch wrote:
> > I'd be glad if you could give me any ideas on how to achieve this 
> > behaviour in another way (and not setting recv_timeo and polling
> accept!)
> In such situations, I guess you'd normally use select to not let the
> 
> accept task block in accept. You can then either have select use a 
> timeout and check a flag (but that might be polling accept as you
> wrote)
> or use a (loopback) socket that is only used to send a shutdown
> flag:
> The accept thread then waits on the accept-socket and the 
> loopback-socket, it will get woken up when you send the shutdown flag 
> to the loopback-socket.
> Simon
> ------------------------------
> Message: 5
> Date: Fri, 16 Oct 2009 10:29:14 -0400
> From: "David Shmelzer" 
> Subject: RE: [lwip-users] TCP payload is doubled
> To: "Mailing list for lwIP users" 
> Message-ID:
> Content-Type: text/plain; charset="iso-8859-1"
> Thanks Jan. 
> I tried setting TCP_WND_UPDATE_THRESHOLD to 0 and I still get the same

> behaviour of decreasing window size.
> I then reverted to 1.3.0 and the window size stays constant as 
> expected.
> I would stay at 1.3.0 if I could but I need a fix that 1.3.1 has.
> Any help would be greatly appreciated.
> Thanks,
> Dave
> -----Original Message-----
> From: lwip-users-bounces+daves= [mailto:lwip-users-bounces+daves=]
> On Behalf Of Jan Wester
> Sent: Friday, October 16, 2009 7:42 AM
> To: 'Mailing list for lwIP users'
> Subject: SV: [lwip-users] TCP payload is doubled Hi I have the same 
> problem Kieran mention about to set TCP_WND_UPDATE_THRESHOLD = 0. I 
> have not tested yet, will start to test next week Kieran wrote The 
> window advertisement code was re-worked in 1.3.1 to only send an 
> explicit update when the change in window is greater than 
> TCP_WND_UPDATE_THRESHOLD.  This defaults to (TCP_WND / 4). You could 
> define this to be zero to get the old behaviour, but the new behaviour

> should be much better.  I would be interested to know what the problem

> you encounter as a result of the less-frequent window updates is.
> Note that any ACKs for data that get returned should have the 
> up-to-date window information in them
> - it is only the sending of explicit window update ACKs that is 
> restricted.
> /Jan
> -----Ursprungligt meddelande-----
> Fr
> [mailto:lwip-users-bounces+j.wester=] F
> Skickat: den 15 oktober 2009 21:56
> Till: Mailing list for lwIP users
> I did a wireshark capture and the window size from lwip keeps 
> decreasing by the packet length received by lwip for each transaction.
> When it finally decreases to less than the packet size my s/w hiccups 
> because it expects a full packet. So this problem exposed a flaw in my

> software. Is anyone else seeing teh window size decreasing?
> -----Original Message-----
> From: lwip-users-bounces+daves=
> [mailto:lwip-users-bounces+daves=] On Behalf Of Bill Auerbach
> Sent: Wednesday, October 14, 2009 8:13 AM
> To: 'Mailing list for lwIP users'
> Subject: RE: [lwip-users] TCP payload is doubled
> >Occasionally, the payload in my TCP return packet sent from lwip is
> 
> >more bytes than I'm expecting.
> >It looks like it may be concatenating two copies of the payload.
> Does this mean the data received by the application is bad or you're 
> just receiving more of it than you expected but it's all good?
> Bill
> _______________________________________________
> lwip-users mailing list
> http://lists.nongnu.org/mailman/listinfo/lwip-users
> _______________________________________________
> lwip-users mailing list
> http://lists.nongnu.org/mailman/listinfo/lwip-users
> ------------------------------
> _______________________________________________
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> http://lists.nongnu.org/mailman/listinfo/lwip-users
> End of lwip-users Digest, Vol 74, Issue 27
> ******************************************
> 
> 


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