Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next.
Basically, more incremental updates for br_netfilter from Florian
Westphal, small nf_tables updates (including one fix for rb-tree
locking) and small two-liner to add extra validation for the REJECT6
target.

More specifically, they are:

1) Use the conntrack status flags from br_netfilter to know that DNAT is
   happening. Patch for Florian Westphal.

2) nf_bridge->physoutdev == NULL already indicates that the traffic is
   bridged, so let's get rid of the BRNF_BRIDGED flag. Also from Florian.

3) Another patch to prepare voidization of seq_printf/seq_puts/seq_putc,
   from Joe Perches.

4) Consolidation of nf_tables_newtable() error path.

5) Kill nf_bridge_pad used by br_netfilter from ip_fragment(),
   from Florian Westphal.

6) Access rb-tree root node inside the lock and remove unnecessary
   locking from the get path (we already hold nfnl_lock there), from
   Patrick McHardy.

7) You cannot use a NFT_SET_ELEM_INTERVAL_END when the set doesn't
   support interval, also from Patrick.

8) Enforce IP6T_F_PROTO from ip6t_REJECT to make sure the core is
   actually restricting matches to TCP.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 9 deletions

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index b260a97275db..f3884a1b942f 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;
@@ -154,6 +153,18 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
         return nf_bridge;
 }
 
+static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __cpu_to_be16(ETH_P_8021Q):
+                return VLAN_HLEN;
+        case __cpu_to_be16(ETH_P_PPP_SES):
+                return PPPOE_SES_HLEN;
+        default:
+                return 0;
+        }
+}
+
 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
 {
         unsigned int len = nf_bridge_encap_header_len(skb);
@@ -322,6 +333,22 @@ free_skb:
         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 +652,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
                 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,
@@ -721,8 +748,6 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
         if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
                 return NF_DROP;
 
-        /* The physdev module checks on this */
-        nf_bridge->mask |= BRNF_BRIDGED;
         nf_bridge->physoutdev = skb->dev;
         if (pf == NFPROTO_IPV4)
                 skb->protocol = htons(ETH_P_IP);
@@ -842,7 +867,12 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
         struct net_device *realoutdev = bridge_parent(skb->dev);
         u_int8_t pf;
 
-        if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
+        /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in
+         * on a bridge, but was delivered locally and is now being routed:
+         *
+         * POST_ROUTING was already invoked from the ip stack.
+         */
+        if (!nf_bridge || !nf_bridge->physoutdev)
                 return NF_ACCEPT;
 
         if (!realoutdev)