netfilter: flowtable: add encap_proto to flow_offload_tunnel

Add encap_proto (AF_INET or AF_INET6) to struct flow_offload_tunnel
to allow its use as part of the hash table key during flowtable entry
lookup.
This is a preliminary change to support IPv4 over IPv6 tunneling via
the flowtable infrastructure for software acceleration.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netdevice.h

@@ -911,6 +911,7 @@ struct net_device_path {
 			};
 
 			u8	inner_proto;
+			u8	encap_proto;
 		} tun;
 		struct {
 			enum {

include/net/netfilter/nf_flow_table.h

@@ -118,6 +118,7 @@ struct flow_offload_tunnel {
 	};
 
 	u8	inner_proto;
+	u8	encap_proto;
 };
 
 struct flow_offload_tuple {

net/ipv4/ipip.c

@@ -379,6 +379,7 @@ static int ipip_fill_forward_path(struct net_device_path_ctx *ctx,
 	path->tun.src_v4.s_addr = tiph->saddr;
 	path->tun.dst_v4.s_addr = tiph->daddr;
 	path->tun.inner_proto = IPPROTO_IPIP;
+	path->tun.encap_proto = AF_INET;
 	path->tun.dst = &rt->dst;
 	path->dev = ctx->dev;
 

net/ipv6/ip6_tunnel.c

@@ -1868,6 +1868,7 @@ static int ip6_tnl_fill_forward_path(struct net_device_path_ctx *ctx,
 		path->tun.src_v6 = fl6.saddr;
 		path->tun.dst_v6 = fl6.daddr;
 		path->tun.inner_proto = IPPROTO_IPV6;
+		path->tun.encap_proto = AF_INET6;
 		path->tun.dst = dst;
 		path->dev = ctx->dev;
 		ctx->dev = dst->dev;

net/netfilter/nf_flow_table_ip.c

@@ -199,12 +199,14 @@ static void nf_flow_tuple_encap(struct nf_flowtable_ctx *ctx,
 		tuple->tun.dst_v4.s_addr = iph->daddr;
 		tuple->tun.src_v4.s_addr = iph->saddr;
 		tuple->tun.inner_proto = ctx->tun.inner_proto;
+		tuple->tun.encap_proto = AF_INET;
 		break;
 	case htons(ETH_P_IPV6):
 		ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
 		tuple->tun.dst_v6 = ip6h->daddr;
 		tuple->tun.src_v6 = ip6h->saddr;
 		tuple->tun.inner_proto = ctx->tun.inner_proto;
+		tuple->tun.encap_proto = AF_INET6;
 		break;
 	default:
 		break;

net/netfilter/nf_flow_table_path.c

@@ -138,6 +138,7 @@ static int nft_dev_path_info(struct net_device_path_stack *stack,
 				info->tun.dst_v6 = path->tun.dst_v6;
 				info->tun.inner_proto = path->tun.inner_proto;
 				info->tun_dst = path->tun.dst;
+				info->tun.encap_proto = path->tun.encap_proto;
 				info->num_tuns++;
 			} else {
 				if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX)
@@ -249,6 +250,7 @@ static int nft_dev_forward_path(const struct nft_pktinfo *pkt,
 		route->tuple[!dir].in.tun.src_v6 = info.tun.dst_v6;
 		route->tuple[!dir].in.tun.dst_v6 = info.tun.src_v6;
 		route->tuple[!dir].in.tun.inner_proto = info.tun.inner_proto;
+		route->tuple[!dir].in.tun.encap_proto = info.tun.encap_proto;
 		route->tuple[!dir].in.num_tuns = info.num_tuns;
 		dst_release(route->tuple[dir].dst);
 		route->tuple[dir].dst = info.tun_dst;