cardigliano at ntop
May 12, 2012, 8:16 AM
Post #2 of 2
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Mike
the "displ" parameter (usually 0 or 14) contains the displacement of the ethernet header with respect to the ska->data pointer.
In a nutshell, when you have to access the packet data you should take into account "displ" when computing the offset.
Example:
u_int payload_offset = hdr->extended_hdr.parsed_pkt.offset.payload_offset - displ;
char *payload = &skb->data[payload_offset];
Regards
Alfredo
On May 11, 2012, at 4:50 PM, Mike Drangula wrote:
> Hi. I’m trying to write a PF_RING plugin and I need to understand the context and usage of the displ argument passed to pfring_plugin_filter_skb and pfring_plugin_handle_skb.
>
> I’ve been browsing the source and the real meaning of displ is not obvious.
>
> Thanks in advance for your help,
>
> Mike Drangula | Sr. Software Engineer
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