netfilter: push reasm skb through instead of original frag skbs
Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:
<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT
and on HOSTB you do:
ping6 HOSTA -s2000 (MTU is 1500)
Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>
As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.
Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index cd7275f..5679d92 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -109,7 +109,6 @@
struct ip_vs_iphdr {
__u32 len; /* IPv4 simply where L4 starts
IPv6 where L4 Transport Header starts */
- __u32 thoff_reasm; /* Transport Header Offset in nfct_reasm skb */
__u16 fragoffs; /* IPv6 fragment offset, 0 if first frag (or not frag)*/
__s16 protocol;
__s32 flags;
@@ -117,34 +116,12 @@
union nf_inet_addr daddr;
};
-/* Dependency to module: nf_defrag_ipv6 */
-#if defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
-static inline struct sk_buff *skb_nfct_reasm(const struct sk_buff *skb)
-{
- return skb->nfct_reasm;
-}
-static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
- int len, void *buffer,
- const struct ip_vs_iphdr *ipvsh)
-{
- if (unlikely(ipvsh->fragoffs && skb_nfct_reasm(skb)))
- return skb_header_pointer(skb_nfct_reasm(skb),
- ipvsh->thoff_reasm, len, buffer);
-
- return skb_header_pointer(skb, offset, len, buffer);
-}
-#else
-static inline struct sk_buff *skb_nfct_reasm(const struct sk_buff *skb)
-{
- return NULL;
-}
static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
int len, void *buffer,
const struct ip_vs_iphdr *ipvsh)
{
return skb_header_pointer(skb, offset, len, buffer);
}
-#endif
static inline void
ip_vs_fill_ip4hdr(const void *nh, struct ip_vs_iphdr *iphdr)
@@ -171,19 +148,12 @@
(struct ipv6hdr *)skb_network_header(skb);
iphdr->saddr.in6 = iph->saddr;
iphdr->daddr.in6 = iph->daddr;
- /* ipv6_find_hdr() updates len, flags, thoff_reasm */
- iphdr->thoff_reasm = 0;
+ /* ipv6_find_hdr() updates len, flags */
iphdr->len = 0;
iphdr->flags = 0;
iphdr->protocol = ipv6_find_hdr(skb, &iphdr->len, -1,
&iphdr->fragoffs,
&iphdr->flags);
- /* get proto from re-assembled packet and it's offset */
- if (skb_nfct_reasm(skb))
- iphdr->protocol = ipv6_find_hdr(skb_nfct_reasm(skb),
- &iphdr->thoff_reasm,
- -1, NULL, NULL);
-
} else
#endif
{