RE: [lwip-users] "the ARP layer is not protected againstconcurrent access"

[Goldschmidt Simon]

Hi,

> Sounds like a reasonable suggestion to me.  I'm slightly 
> concerned by you saying that the tcpip_input() function 
> wouldn't be needed anymore.
> Can you explain why?

That statement was only be true for 'new' drivers: they would call 
tcpip_input_w_arp() for IP packets and tcpip_arp_input() for ARP packets; 
tcpip_input() (without ARP) could only be used by old drivers. I wouldn't 
remove it, only not use it for new drivers (IF we want the two mechanisms to 
coexist; but I guess we have to in order to support ppp?).
The solution which Frédéric proposed is simpler, but sends ALL packets to the 
tcpip_thread. Filtering them before passing on seemed more performant to me.

> 
> > AS far as I know (but I'm not using it by now), that 
> wouldn't affect 
> > raw API programs running without an OS, since they don't 
> use messages, 
> > anyway. This would simply be a matter of assigning another input 
> > function for netifs (and maybe another input function, e.g. netif-
> > >arp_input()).
> 
> Any raw API users/experts care to comment on this aspect?  
> Would be nice if we could come up with a simple solution that 
> addressed this problem for all APIs.

That's definitively what I want, too. And I started using the raw API to test 
this, but I cannot guarantee to see everything that matters since I'm only 
beginning to use this.
So, comments are still welcome!

Simon.