From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicole <nicole@cats-muvva.net>
Subject: Connection Tracking
Date: Mon, 03 Sep 2012 17:35:56 +0100
Message-ID: <5044DC6C.1070806@cats-muvva.net>
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Hello everyone,

I would be grateful for some advice. Am writing a target using xtables.
This target saves and restores a field in the IPv{4,6} header to/from
the connection mark.

I have read Jan Engelhardt's booklet (3 July 2012), but remain unclear
on how to ensure that connection tracking is turned on.

My difficulty arises in the following code snippet:

        const struct nf_conn *ct;
        ct = nf_ct_get(skb, &ctinfo);
        if (ct == NULL) {
                return false;
        }
	/* use ct-> */

ct is always false and therefore I cannot do the save and restore.

Any suggestions?

Many thanks

Nicole