[PATCH nf 2/2 v4] bridge: set the pktinfo for IPv4/IPv6 traffic

[Alvaro Neira Ayuso <alvaroneay@gmail.com>]

This patch adds the missing bits to allow to match per meta l4proto from
the bridge. Example:

  nft add rule bridge filter input ether type {ip, ip6} meta l4proto udp counter

Signed-off-by: Alvaro Neira Ayuso <alvaroneay@gmail.com>
---
[changes in v4]
 * refactor the code in two functions nft_bridge_set_pktinfo_ipv*

 net/bridge/netfilter/nf_tables_bridge.c |   42 ++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/net/bridge/netfilter/nf_tables_bridge.c b/net/bridge/netfilter/nf_tables_bridge.c
index d468c19..32341fd 100644
--- a/net/bridge/netfilter/nf_tables_bridge.c
+++ b/net/bridge/netfilter/nf_tables_bridge.c
@@ -16,6 +16,8 @@
 #include <net/netfilter/nf_tables_bridge.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <net/netfilter/nf_tables_ipv4.h>
+#include <net/netfilter/nf_tables_ipv6.h>
 
 int nft_bridge_iphdr_validate(struct sk_buff *skb)
 {
@@ -62,6 +64,34 @@ int nft_bridge_ip6hdr_validate(struct sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate);
 
+static inline int nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
+					      const struct nf_hook_ops *ops,
+					      struct sk_buff *skb,
+					      const struct net_device *in,
+					      const struct net_device *out)
+{
+	if (!nft_bridge_iphdr_validate(skb))
+		nft_set_pktinfo(pkt, ops, skb, in, out);
+	else
+		nft_set_pktinfo_ipv4(pkt, ops, skb, in, out);
+
+	return 0;
+}
+
+static inline int nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
+					      const struct nf_hook_ops *ops,
+					      struct sk_buff *skb,
+					      const struct net_device *in,
+					      const struct net_device *out)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (nft_bridge_ip6hdr_validate(skb) &&
+	    nft_set_pktinfo_ipv6(pkt, ops, skb, in, out) == 0)
+		return 1;
+#endif
+	return 0;
+}
+
 static unsigned int
 nft_do_chain_bridge(const struct nf_hook_ops *ops,
 		    struct sk_buff *skb,
@@ -71,7 +101,17 @@ nft_do_chain_bridge(const struct nf_hook_ops *ops,
 {
 	struct nft_pktinfo pkt;
 
-	nft_set_pktinfo(&pkt, ops, skb, in, out);
+	switch (eth_hdr(skb)->h_proto) {
+	case htons(ETH_P_IP):
+		nft_bridge_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
+		break;
+	case htons(ETH_P_IPV6):
+		if (nft_bridge_set_pktinfo_ipv6(&pkt, ops, skb, in, out) > 0)
+			break;
+	default:
+		nft_set_pktinfo(&pkt, ops, skb, in, out);
+		break;
+	}
 
 	return nft_do_chain(&pkt, ops);
 }
-- 
1.7.10.4