[lwip-users] Filtering ICMP packets in ping example

[Grzegorz Niemirowski]

Hello all.
While working with ping example from contrib I noticed strange effect: there 
was no timeout when an unreachable address was pinged and the while loop 
inside ping_recv was constantly executing  It turned out that it was because 
the device was constantly pinged from a PC to check if the TCP/IP stack is 
working. Therefore the socket was not receiving replies from pinged address 
but it was receiving echo requests from PC.
So here is my question: is it possible to filter out ICMP packets which are 
not from pinged address? Or I need to stop relaying on the SO_RCVTIMEO 
timeout associated with a socket and measure elapsed time with additional 
code?

Grzegorz Niemirowski
http://www.grzegorz.net/