Re: [dpdk-dev] Packet crafting....

[sabu kurian <sabu2kurian@gmail.com>]

Thank you very much Richardson for your valuable reply. But is there
another way of doing it using the rte_pktmbuf_append / rte_pktmbuf_prepend ?
Can you please tell me on how to do that ?

Regards


On Fri, Mar 14, 2014 at 3:27 PM, Richardson, Bruce <
bruce.richardson@intel.com> wrote:

> > Hello friends,
> >
> > As of now... I know on how to create an ipv4 header using the 'struct
> > ipv4_hdr'.
> > My requirement is to craft a packet and sent it via 'rte_eth_tx_burst'.
> > I know that there should be an 'ether_hdr' created before, the packet
> could
> > be sent.
> > Could someone help me on how to set the address fields and type in
> > 'ether_hdr' and how to put the ipv4 header as the payload for ether_hdr.
> >
>
> You probably want to do something like this to craft a full packet. First
> allocate an mbuf, then get it's data pointer as a ether_hdr structure, then
> an ip_hdr beyond that and then any L4 headers, e.g. udp, beyond that. For
> example, assuming mempool variable p:
>
>     struct rte_mbuf *buf = rte_pktmbuf_alloc(p);
>     struct ether_hdr *ehdr = rte_pktmbuf_mtod(buf, struct ether_hdr *);
> /* set ether_hdr fields here e.g. */
>     ehdr->ether_type = rte_bswap16(ETHER_TYPE_IPv4);
>     struct ipv4_hdr *iphdr = (struct ipv4_hdr *)(&ehdr[1]);
> /* set ipv4 header fields here */
>     struct udp_hdr *uhdr = (struct udp_hdr *)(&iphdr[1]);
> /* set udp header fields here, e.g. */
>     uhdr->src_port = rte_bswap16(0x5000);
>