[NETFILTER]: Call POST_ROUTING hook before fragmentation
Call POST_ROUTING hook before fragmentation to get rid of the okfn use
in ip_refrag and save the useless fragmentation/defragmentation step
when NAT is used.
The patch introduces one user-visible change, the POSTROUTING chain
in the mangle table gets entire packets, not fragments, which should
simplify use of the MARK and CLASSIFY targets for queueing as a nice
side-effect.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index f7e7fd7..7bb5804 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -317,7 +317,6 @@
IP_DEFRAG_CALL_RA_CHAIN,
IP_DEFRAG_CONNTRACK_IN,
IP_DEFRAG_CONNTRACK_OUT,
- IP_DEFRAG_NAT_OUT,
IP_DEFRAG_VS_IN,
IP_DEFRAG_VS_OUT,
IP_DEFRAG_VS_FWD
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 2a830de..71da318 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -202,13 +202,11 @@
static inline int ip_finish_output(struct sk_buff *skb)
{
- struct net_device *dev = skb->dst->dev;
-
- skb->dev = dev;
- skb->protocol = htons(ETH_P_IP);
-
- return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev,
- ip_finish_output2);
+ if (skb->len > dst_mtu(skb->dst) &&
+ !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size))
+ return ip_fragment(skb, ip_finish_output2);
+ else
+ return ip_finish_output2(skb);
}
int ip_mc_output(struct sk_buff *skb)
@@ -265,21 +263,21 @@
newskb->dev, ip_dev_loopback_xmit);
}
- if (skb->len > dst_mtu(&rt->u.dst))
- return ip_fragment(skb, ip_finish_output);
- else
- return ip_finish_output(skb);
+ return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev,
+ ip_finish_output);
}
int ip_output(struct sk_buff *skb)
{
+ struct net_device *dev = skb->dst->dev;
+
IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
- if (skb->len > dst_mtu(skb->dst) &&
- !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size))
- return ip_fragment(skb, ip_finish_output);
- else
- return ip_finish_output(skb);
+ skb->dev = dev;
+ skb->protocol = htons(ETH_P_IP);
+
+ return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev,
+ ip_finish_output);
}
int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
diff --git a/net/ipv4/netfilter/ip_conntrack_standalone.c b/net/ipv4/netfilter/ip_conntrack_standalone.c
index a88bcc5..7ba9778 100644
--- a/net/ipv4/netfilter/ip_conntrack_standalone.c
+++ b/net/ipv4/netfilter/ip_conntrack_standalone.c
@@ -451,30 +451,6 @@
return NF_ACCEPT;
}
-static unsigned int ip_refrag(unsigned int hooknum,
- struct sk_buff **pskb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- struct rtable *rt = (struct rtable *)(*pskb)->dst;
-
- /* We've seen it coming out the other side: confirm */
- if (ip_confirm(hooknum, pskb, in, out, okfn) != NF_ACCEPT)
- return NF_DROP;
-
- /* Local packets are never produced too large for their
- interface. We degfragment them at LOCAL_OUT, however,
- so we have to refragment them here. */
- if ((*pskb)->len > dst_mtu(&rt->u.dst) &&
- !skb_shinfo(*pskb)->tso_size) {
- /* No hook can be after us, so this should be OK. */
- ip_fragment(*pskb, okfn);
- return NF_STOLEN;
- }
- return NF_ACCEPT;
-}
-
static unsigned int ip_conntrack_local(unsigned int hooknum,
struct sk_buff **pskb,
const struct net_device *in,
@@ -544,7 +520,7 @@
/* Refragmenter; last chance. */
static struct nf_hook_ops ip_conntrack_out_ops = {
- .hook = ip_refrag,
+ .hook = ip_confirm,
.owner = THIS_MODULE,
.pf = PF_INET,
.hooknum = NF_IP_POST_ROUTING,
diff --git a/net/ipv4/netfilter/ip_nat_standalone.c b/net/ipv4/netfilter/ip_nat_standalone.c
index 30cd4e1..f04111f 100644
--- a/net/ipv4/netfilter/ip_nat_standalone.c
+++ b/net/ipv4/netfilter/ip_nat_standalone.c
@@ -190,23 +190,6 @@
|| (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
return NF_ACCEPT;
- /* We can hit fragment here; forwarded packets get
- defragmented by connection tracking coming in, then
- fragmented (grr) by the forward code.
-
- In future: If we have nfct != NULL, AND we have NAT
- initialized, AND there is no helper, then we can do full
- NAPT on the head, and IP-address-only NAT on the rest.
-
- I'm starting to have nightmares about fragments. */
-
- if ((*pskb)->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
- *pskb = ip_ct_gather_frags(*pskb, IP_DEFRAG_NAT_OUT);
-
- if (!*pskb)
- return NF_STOLEN;
- }
-
return ip_nat_fn(hooknum, pskb, in, out, okfn);
}
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 385867e..1d36e8e 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -180,30 +180,6 @@
return NF_ACCEPT;
}
-static unsigned int ipv4_refrag(unsigned int hooknum,
- struct sk_buff **pskb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- struct rtable *rt = (struct rtable *)(*pskb)->dst;
-
- /* We've seen it coming out the other side: confirm */
- if (ipv4_confirm(hooknum, pskb, in, out, okfn) != NF_ACCEPT)
- return NF_DROP;
-
- /* Local packets are never produced too large for their
- interface. We degfragment them at LOCAL_OUT, however,
- so we have to refragment them here. */
- if ((*pskb)->len > dst_mtu(&rt->u.dst) &&
- !skb_shinfo(*pskb)->tso_size) {
- /* No hook can be after us, so this should be OK. */
- ip_fragment(*pskb, okfn);
- return NF_STOLEN;
- }
- return NF_ACCEPT;
-}
-
static unsigned int ipv4_conntrack_in(unsigned int hooknum,
struct sk_buff **pskb,
const struct net_device *in,
@@ -283,7 +259,7 @@
/* Refragmenter; last chance. */
static struct nf_hook_ops ipv4_conntrack_out_ops = {
- .hook = ipv4_refrag,
+ .hook = ipv4_confirm,
.owner = THIS_MODULE,
.pf = PF_INET,
.hooknum = NF_IP_POST_ROUTING,
