picotcp tftp support [was Adding IPv4 multicast support]

[Daniele Lacamera]

Hi Antony, hello all,

It's been a bit of slow-business here lately, due to the end of the
summer holidays.
We have put two people on the task since this week, we will keep you posted!

Thanks for bearing with us!

Greetings,

-- 
Daniele

On Thu, Sep 4, 2014 at 7:14 PM, Antony Pavlov <antonynpavlov at gmail.com> wrote:
> On Wed, 16 Jul 2014 08:48:18 +0200
> Daniele Lacamera <daniele.lacamera at tass.be> wrote:
>
>> On Wed, Jul 16, 2014 at 8:30 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
>> > Right now the network users register to a udp port and provide a handler
>> > which is called whenever a packet to this port is received. The
>> > prototype for this function is:
>> >
>> > struct net_connection *net_udp_new(IPaddr_t dest, uint16_t dport,
>> >                 rx_handler_f *handler, void *ctx);
>> >
>> > Then network users can send packets on this connection:
>> >
>> > int net_udp_send(struct net_connection *con, int len);
>> >
>> > The function returns after the packet has been sent.
>> >
>> > The network user has to keep the ball rolling by calling
>> >
>> > void net_poll(void);
>> >
>> > in a loop. This function will call into the network drivers receive
>> > function and dispatch the received packets. ARP packets are handled
>> > internally, the UDP packets are passed to the registered handlers.
>> >
>> > The handlers usually will send answers to received packets (so a tftp
>> > client will send an ack here or request the next packet).
>> >
>> > Usually the loop calling net_poll() also has some functionality to
>> > detect progress and will send the last packet again if it was lost.
>> >
>> > Hope that explains the networking model in barebox.
>> >
>>
>> Hi Sascha,
>>
>> Thanks a lot for this clarification. The mechanism you described is
>> the same as the native execution model of PicoTCP, and looking around
>> in the code it seems that looping around net_poll() was in fact the
>> way to go.
>>
>> to Antony: I will improve TFTP first, by allowing multiple sessions at
>> the same time. I will keep you posted on the progress.
>
> I see a barebox-related publication with nice pictures on the picotcp website  :)
>
>   http://www.picotcp.com/barebox-on-top-of-picotcp
>
> We are awaiting improved TFTP...
>
> --
> Best regards,
>   Antony Pavlov