netfilter: flowtable: add counter support

Add a new flag to turn on flowtable counters which are stored in the
conntrack entry.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_flow_table.h

@@ -63,6 +63,7 @@ struct nf_flowtable_type {
 
 enum nf_flowtable_flags {
 	NF_FLOWTABLE_HW_OFFLOAD		= 0x1,	/* NFT_FLOWTABLE_HW_OFFLOAD */
+	NF_FLOWTABLE_COUNTER		= 0x2,	/* NFT_FLOWTABLE_COUNTER */
 };
 
 struct nf_flowtable {

include/uapi/linux/netfilter/nf_tables.h

@@ -1557,10 +1557,13 @@ enum nft_object_attributes {
  * enum nft_flowtable_flags - nf_tables flowtable flags
  *
  * @NFT_FLOWTABLE_HW_OFFLOAD: flowtable hardware offload is enabled
+ * @NFT_FLOWTABLE_COUNTER: enable flow counters
  */
 enum nft_flowtable_flags {
 	NFT_FLOWTABLE_HW_OFFLOAD	= 0x1,
-	NFT_FLOWTABLE_MASK		= NFT_FLOWTABLE_HW_OFFLOAD
+	NFT_FLOWTABLE_COUNTER		= 0x2,
+	NFT_FLOWTABLE_MASK		= (NFT_FLOWTABLE_HW_OFFLOAD |
+					   NFT_FLOWTABLE_COUNTER)
 };
 
 /**

net/netfilter/nf_flow_table_ip.c

@@ -12,6 +12,7 @@
 #include <net/ip6_route.h>
 #include <net/neighbour.h>
 #include <net/netfilter/nf_flow_table.h>
+#include <net/netfilter/nf_conntrack_acct.h>
 /* For layer 4 checksum field offset. */
 #include <linux/tcp.h>
 #include <linux/udp.h>
@@ -286,6 +287,9 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	ip_decrease_ttl(iph);
 	skb->tstamp = 0;
 
+	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
+		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
+
 	if (unlikely(dst_xfrm(&rt->dst))) {
 		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
 		IPCB(skb)->iif = skb->dev->ifindex;
@@ -516,6 +520,9 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	ip6h->hop_limit--;
 	skb->tstamp = 0;
 
+	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
+		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
+
 	if (unlikely(dst_xfrm(&rt->dst))) {
 		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 		IP6CB(skb)->iif = skb->dev->ifindex;