netfilter: bridge: query conntrack about skb dnat
ask conntrack instead of storing ipv4 address in nf_bridge_info->data.
Ths avoids the need to use ->data during NF_PRE_ROUTING.
Only two functions that need ->data remain.
These will be addressed in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index b260a97..261fcd5 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -37,17 +37,16 @@
#include <net/route.h>
#include <net/netfilter/br_netfilter.h>
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
#include <asm/uaccess.h>
#include "br_private.h"
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
-#define skb_origaddr(skb) (((struct bridge_skb_cb *) \
- (skb->nf_bridge->data))->daddr.ipv4)
-#define store_orig_dstaddr(skb) (skb_origaddr(skb) = ip_hdr(skb)->daddr)
-#define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr)
-
#ifdef CONFIG_SYSCTL
static struct ctl_table_header *brnf_sysctl_header;
static int brnf_call_iptables __read_mostly = 1;
@@ -322,6 +321,22 @@
return 0;
}
+static bool dnat_took_place(const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || nf_ct_is_untracked(ct))
+ return false;
+
+ return test_bit(IPS_DST_NAT_BIT, &ct->status);
+#else
+ return false;
+#endif
+}
+
/* This requires some explaining. If DNAT has taken place,
* we will need to fix up the destination Ethernet address.
*
@@ -625,7 +640,7 @@
return NF_DROP;
if (!setup_pre_routing(skb))
return NF_DROP;
- store_orig_dstaddr(skb);
+
skb->protocol = htons(ETH_P_IP);
NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,