netdev - Re: ipsec and netfilter

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Date:	Thu, 19 Feb 2009 20:57:25 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Joe Pruett <joey@...an.q7.com>
Cc:	netdev@...r.kernel.org
Subject: Re: ipsec and netfilter

Joe Pruett <joey@...an.q7.com> wrote:
>
> why aren't esp/ah packets run through netfilter again after 
> decryption/decapsulation?  in tunnel mode, packets do get sent in again, 
> but that is only because ip-ip does that, not the ipsec code.

They do go through netfilter again after decap in transport mode:

int xfrm4_transport_finish(struct sk_buff *skb, int async)
{
	struct iphdr *iph = ip_hdr(skb);

	iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;

#ifndef CONFIG_NETFILTER
	if (!async)
		return -iph->protocol;
#endif

	__skb_push(skb, skb->data - skb_network_header(skb));
	iph->tot_len = htons(skb->len);
	ip_send_check(iph);

	NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
		xfrm4_rcv_encap_finish);
	return 0;
}

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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