From 6aafeef03b9d9ecf255f3a80ed85ee070260e1ae Mon Sep 17 00:00:00 2001
From: Jiri Pirko
Date: Wed, 6 Nov 2013 17:52:20 +0100
Subject: 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:
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)
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
Acked-by: Julian Anastasov
Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
---
net/netfilter/ipvs/ip_vs_core.c | 55 +--------------------------------------
net/netfilter/ipvs/ip_vs_pe_sip.c | 8 +-----
2 files changed, 2 insertions(+), 61 deletions(-)
(limited to 'net/netfilter')
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 34fda62f40f6..4f26ee46b51f 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -1139,12 +1139,6 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af)
ip_vs_fill_iph_skb(af, skb, &iph);
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
- if (!iph.fragoffs && skb_nfct_reasm(skb)) {
- struct sk_buff *reasm = skb_nfct_reasm(skb);
- /* Save fw mark for coming frags */
- reasm->ipvs_property = 1;
- reasm->mark = skb->mark;
- }
if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
int related;
int verdict = ip_vs_out_icmp_v6(skb, &related,
@@ -1614,12 +1608,6 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
- if (!iph.fragoffs && skb_nfct_reasm(skb)) {
- struct sk_buff *reasm = skb_nfct_reasm(skb);
- /* Save fw mark for coming frags. */
- reasm->ipvs_property = 1;
- reasm->mark = skb->mark;
- }
if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
int related;
int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum,
@@ -1671,9 +1659,8 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
/* sorry, all this trouble for a no-hit :) */
IP_VS_DBG_PKT(12, af, pp, skb, 0,
"ip_vs_in: packet continues traversal as normal");
- if (iph.fragoffs && !skb_nfct_reasm(skb)) {
+ if (iph.fragoffs) {
/* Fragment that couldn't be mapped to a conn entry
- * and don't have any pointer to a reasm skb
* is missing module nf_defrag_ipv6
*/
IP_VS_DBG_RL("Unhandled frag, load nf_defrag_ipv6\n");
@@ -1755,38 +1742,6 @@ ip_vs_local_request4(const struct nf_hook_ops *ops, struct sk_buff *skb,
#ifdef CONFIG_IP_VS_IPV6
-/*
- * AF_INET6 fragment handling
- * Copy info from first fragment, to the rest of them.
- */
-static unsigned int
-ip_vs_preroute_frag6(const struct nf_hook_ops *ops, struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- struct sk_buff *reasm = skb_nfct_reasm(skb);
- struct net *net;
-
- /* Skip if not a "replay" from nf_ct_frag6_output or first fragment.
- * ipvs_property is set when checking first fragment
- * in ip_vs_in() and ip_vs_out().
- */
- if (reasm)
- IP_VS_DBG(2, "Fragment recv prop:%d\n", reasm->ipvs_property);
- if (!reasm || !reasm->ipvs_property)
- return NF_ACCEPT;
-
- net = skb_net(skb);
- if (!net_ipvs(net)->enable)
- return NF_ACCEPT;
-
- /* Copy stored fw mark, saved in ip_vs_{in,out} */
- skb->mark = reasm->mark;
-
- return NF_ACCEPT;
-}
-
/*
* AF_INET6 handler in NF_INET_LOCAL_IN chain
* Schedule and forward packets from remote clients
@@ -1924,14 +1879,6 @@ static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
.priority = 100,
},
#ifdef CONFIG_IP_VS_IPV6
- /* After mangle & nat fetch 2:nd fragment and following */
- {
- .hook = ip_vs_preroute_frag6,
- .owner = THIS_MODULE,
- .pf = NFPROTO_IPV6,
- .hooknum = NF_INET_PRE_ROUTING,
- .priority = NF_IP6_PRI_NAT_DST + 1,
- },
/* After packet filtering, change source only for VS/NAT */
{
.hook = ip_vs_reply6,
diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
index 9ef22bdce9f1..bed5f7042529 100644
--- a/net/netfilter/ipvs/ip_vs_pe_sip.c
+++ b/net/netfilter/ipvs/ip_vs_pe_sip.c
@@ -65,7 +65,6 @@ static int get_callid(const char *dptr, unsigned int dataoff,
static int
ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
{
- struct sk_buff *reasm = skb_nfct_reasm(skb);
struct ip_vs_iphdr iph;
unsigned int dataoff, datalen, matchoff, matchlen;
const char *dptr;
@@ -79,15 +78,10 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
/* todo: IPv6 fragments:
* I think this only should be done for the first fragment. /HS
*/
- if (reasm) {
- skb = reasm;
- dataoff = iph.thoff_reasm + sizeof(struct udphdr);
- } else
- dataoff = iph.len + sizeof(struct udphdr);
+ dataoff = iph.len + sizeof(struct udphdr);
if (dataoff >= skb->len)
return -EINVAL;
- /* todo: Check if this will mess-up the reasm skb !!! /HS */
retc = skb_linearize(skb);
if (retc < 0)
return retc;
--
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