[lwip-users] TCP/UDP socket writing with RAW API and NO_SYS==1

[mcondarelli]

Hi,
where can I find some examples on how to manage correct inter-process 
communications for RAW sockets?

My use case is I need to create and bind a bunch of sockets (both TCP & UDP) to 
implement some custom services.

Services fall in the following categories:

I have several tasks producing output (printouts or something akin); this 
output should be redirected to sockets. If and when a client connects to the 
socket the output is sent to it, otherwise it is silently dropped on the floor.

One task is a full fledged server listening on TCP ( I plan to use connection 
API for this).

Production (from several independent tasks!) of UDP-514 messages to log 
off-board using the standard linux syslog facilities. This would need to 
connect, not bind, of course.

Maybe incorporate http-raw from the contrib directory.

I have been able to implement a simple "echo" application because it is 
initiated by the net, but I do not know is how to have other, independent, 
tasks to initiate action.

What baffles me is the "[..] there is one main thread running the lwIP core
(also known as the "tcpip_thread"). The raw API may only be used from
this thread!" part.

How can I initiate communications from another thread?
What is the RightWay to wake the "tcpip_thread" and have it perform its job?

I am obviously missing some piece of information.
Can someone point me in the right direction, please?

Best Regards
Mauro