On Mon, 2007-03-12 at 07:34 -0500, jamal wrote:
> The point brought up on v6 extensions needs to be addressed. I thought
> about it a little - and it is valid as well for ipv4 options; they will
> be processed twice.
> To build up on what Patrick said, I noticed a bit still available in the
> bag right after skb->nf_trace that i could use to signal
> "options/extensions already processed".
> If people think think this is a sane use of that very lonely bit, I will
> post patches.
And the patch included demonstrates the thought (I thought i had sent it
to the list on monday; seems only to Yoshfuji). Note, blah is not a
proper name, just an emphasis.
cheers,
jama
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d39f53e..78ac7d0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -288,7 +288,8 @@ struct sk_buff {
__u8 pkt_type:3,
fclone:2,
ipvs_property:1,
- nf_trace:1;
+ nf_trace:1,
+ blah:1;
__be16 protocol;
void (*destructor)(struct sk_buff *skb);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6bfc8c8..da7788f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -437,6 +437,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
new->tc_verd = old->tc_verd;
#endif
#endif
+ new->blah = old->blah;
skb_copy_secmark(new, old);
}
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 6563139..6e1e4b0 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -348,9 +348,10 @@ static int ip_rcv_finish(struct sk_buff *skb)
}
#endif
- if (iph->ihl > 5 && ip_rcv_options(skb))
+ if (iph->ihl > 5 || (!skb->blah && ip_rcv_options(skb)))
goto drop;
+ skb->blah = 1;
rt = (struct rtable*)skb->dst;
if (rt->rt_type == RTN_MULTICAST)
IP_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS);
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 0c377a6..1271668 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -50,20 +50,25 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
-#ifdef CONFIG_NETFILTER
+ if (async)
+ return xfrm4_rcv_encap_finish(skb);
+
__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;
-#else
- if (async)
- return xfrm4_rcv_encap_finish(skb);
+ dst_release(skb->dst);
+ skb->dst = NULL;
+ {
+ /* make some packet-sock user (eg tcpdump) happy */
+ const unsigned char *old_mac;
+ old_mac = skb_mac_header(skb);
+ skb_set_mac_header(skb, -skb->mac_len);
+ memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+ }
- return -iph->protocol;
-#endif
+ netif_rx(skb);
+ return 0;
}
/* If it's a keepalive packet, then just eat it.
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 178aebc..2a573e7 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -158,6 +158,9 @@ static int ip6_input_finish(struct sk_buff *skb)
u8 hash;
struct inet6_dev *idev;
+ if (skb->blah)
+ goto ext_parse_done;
+
/*
* Parse extension headers
*/
@@ -215,6 +218,9 @@ resubmit:
kfree_skb(skb);
}
rcu_read_unlock();
+
+ skb->blah = 1;
+ext_parse_done:
return 0;
discard:
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index e2c3efd..c741fba 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -33,19 +33,24 @@ int xfrm6_transport_finish(struct sk_buff *skb, int async)
skb_network_header(skb)[IP6CB(skb)->nhoff] =
XFRM_MODE_SKB_CB(skb)->protocol;
-#ifdef CONFIG_NETFILTER
+ if (async)
+ return ip6_rcv_finish(skb);
+
ipv6_hdr(skb)->payload_len = htons(skb->len);
__skb_push(skb, skb->data - skb_network_header(skb));
- NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
- ip6_rcv_finish);
- return -1;
-#else
- if (async)
- return ip6_rcv_finish(skb);
+ dst_release(skb->dst);
+ skb->dst = NULL;
+ {
+ /* make some packet-sock user (eg tcpdump) happy */
+ const unsigned char *old_mac;
+ old_mac = skb_mac_header(skb);
+ skb_set_mac_header(skb, -skb->mac_len);
+ memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+ }
- return 1;
-#endif
+ netif_rx(skb);
+ return 0;
}
int xfrm6_rcv(struct sk_buff *skb)
