[lwip-users] pbuf cycling bug question

[Ofer Epstein]

 

 

Hi,

 

I have come across a serious bug in lwip pbuf implementation. This bug cause the lwip thread to hang up

leaving the Ethernet device dead. It happens that a loop is created after a call to pbuf_queue to queue an already

existing pbuf and it is causing an endless loop in at least two functions, inet_chksum_pseudo and pbuf_queue.

 

Its cause is a fundamental logic problem in the LwIP network(TCP)-link interlayer communications.

The error appears when the packets, which have already been queued but not sent yet, are the

subject to be retransmitted by the TCP algorithm (implemented in slow timer handler).

 

I think this problem was raised before in this mailing list but I could not find a solution to it.

http://lists.gnu.org/archive/html/lwip-users/2007-02/msg00047.html

 

Can anyone please drop some light on this issue?

 

Thanks,

Ofer