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Altera_Forum's avatar
Altera_Forum
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14 years ago

Data send thru ethernet

Hello, I am trying to do a simple task: I will form an UDP packet in hardware, then I want to move it to Nios, add IP header and send to ethernet. I will split my problem into two parts: ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Ok I am moving forward. It is very easy to send udp data using udp_send() in InterNiche, it does everything You need, but I want to prepare UDP data in hardware, so I want to use ip_write only.

That is also pretty easy, but I face some problems:

I prepare the packet same as I would use in udp_send(), but it forms a packet without src/dest ip adresses and I don't know how to set them? The other parts (except adresses and payload) of the packets are OK.

Another problem that the payload is always 10 bytes, no matter if I set the payload length 26 and add required octets to the packet. Maybe someone also had such problems?

here (http://pastebin.com/d1a4qtjg) is the source code.

EDIT: SOLVED ->

Need to add src and dest ip addresses through ip struct: 


    own_address = ip_mymach(pkt->fhost);
    pip = (struct ip *)(pkt->nb_prot - sizeof(struct ip));
    pip->ip_src = own_address;
    pip->ip_dest = pkt->fhost;

----------------------------------------

Now moving towards to add DMA to move payload from hardware to pkt buffer.