All of lore.kernel.org
 help / color / mirror / Atom feed
From: Pablo Neira <pablo@eurodev.net>
To: Gervasio Bernal <gervasiobernal@speedy.com.ar>
Cc: netfilter-devel@lists.netfilter.org
Subject: Re: How to avoid fragmentation
Date: Tue, 25 Oct 2005 01:37:00 +0200	[thread overview]
Message-ID: <435D701C.1080501@eurodev.net> (raw)
In-Reply-To: <435D40ED.1080109@speedy.com.ar>

Gervasio Bernal wrote:
> I'm developing a new target extension and I need to add some extra data
> and headers in TCP/UDP packets. But I'm having a problem: fragmentation.
> In the header developed by me I add a new checksum field to verify the
> integrity of that header. This works fine while there is no
> fragmentation. If the packet is fragmented I can't recalculate that
> checksum.
> 
> Does someone know how to correct or avoid this? Or have experience with
> fragmentation?

Hm, still missing some information. You mean that you can't recalculate 
the checksum because the checksum part is missing, don't you? Use 
skb_header_pointer(...) to work with the headers, it's fragment-aware.

--
Pablo

  reply	other threads:[~2005-10-24 23:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-24 20:15 How to avoid fragmentation Gervasio Bernal
2005-10-24 23:37 ` Pablo Neira [this message]
     [not found]   ` <435D6030.8000509@speedy.com.ar>
2005-10-27 12:41     ` Pablo Neira

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=435D701C.1080501@eurodev.net \
    --to=pablo@eurodev.net \
    --cc=gervasiobernal@speedy.com.ar \
    --cc=netfilter-devel@lists.netfilter.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.