From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Wenhua Zhao" <whzhao@gmail.com>
Subject: Re: attach additional value to skb
Date: Mon, 22 Oct 2007 14:18:44 -0700
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On 10/22/07, Yakov Lerner <iler.ml@gmail.com> wrote:
> 1. How can I attach my 32-bit value to the skb in the
> PRE_ROUTNIG hook such that FORWARD and POST_ROUTING
> hooks can later access this value from the skb ?
>
> Can I use sk_buff->cb for that ?
In IP layer cb is used by IP as structure inet_skb_param.  It is
written by ip_rcv_options() (in function ip_rcv_finish()) between
PRE_ROUTING and FORWARD/POST_ROUTING.

In my opinion, cb is only used when one exclusively owns the skb.

Regards,
Wenhua