[lwip-devel] lwip socket for ICMP messages

[Vinay Purohit]

Hello,

I have a question about using sockets in LWIP for dealing with ICMP
messages.

We want an OS task to send ICMP ECHO REQUEST messages using a socket (which
can be dedicated for ICMP if required) and then receive the corresponding
ICMP ECHO REPLY message back on that same socket. We would like to use a
combination of select() and recvfrom() to retrieve ICMP response messages.
Is it possible with LWIP for an OS task to initiate and receive specific
ICMP messages? If so, what type of a socket (what arguments to
lwip_socket()) would one need to open?

How does the LWIP stack know that ICMP messages it receives should be passed
on to an OS task as opposed to being processed internally given that ICMP
does not have the notion of a port number as is found in UDP/TCP?

Thank you,
Vinay Purohit
Lucent Technologies
908 582 7770