Re: [lwip-users] updated raw api UDP echo server example

[Juri Haberland]

Goldschmidt Simon wrote:
>> > One question remains: I use multicast and bind the pcb to a 
>> > multicast-address.
>> > So when sending, as src.ip the multicast addr is used. Any ideas to 
>> > solve that in a nice way?
>> 
>> Hmm, other than directly manipulating the pcb I would say:
>> use another pcb and do a second udp_bind() to your real IP 
>> address and use this pcb to send the outgoing packets...
> 
> I don't know if that works, as two pcbs would have to be bound
> to the same port. I think there's a todo for that kind of usage.

If I read the code (1.2.0) correctly, it is not tested in udp_bind(),
even though there is code to test it, but this is disabled via
#ifdef LWIP_UDP_TODO, which is not set anywhere. But even then the
mentioned code would allow binding to multicast and one(!) IP address,
but not to multicast and IP_ADDR_ANY.

So, iow the second call to udp_bind() should at least succeed, but if it
really works remains to be tested.

Dominik, your turn ;)

Cheers,
Juri