[PATCH net-next 04/15] netfilter: flowtable: populate tunnel tuple regardless of inner protocol

[Pablo Neira Ayuso <pablo@netfilter.org>]

From: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>

Store the outer tunnel addresses and inner protocol in the flow tuple
unconditionally in nf_flow_tuple_encap(), instead of only when the
tunnel is IP-in-IP or IPv6-in-IPv6. Bail out early when the inner
protocol is neither IPPROTO_IPIP nor IPPROTO_IPV6.
This makes the tuple usable for cross-family tunnels such as
IPv4-over-IPv6 and SIT, where the inner protocol differs from the
outer address family.
This is a preliminary patch to support IPv4 over IPv6 and SIT tunnel
flowtable offload.
Please note IPv4 over IPv6 and SIT tunnel flowtable offloading is not
enabled yet.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_flow_table_ip.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index cd636b4cf74b..a53393f8eda0 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -189,22 +189,22 @@ static void nf_flow_tuple_encap(struct nf_flowtable_ctx *ctx,
 		break;
 	}
 
+	if (ctx->tun.inner_proto != IPPROTO_IPIP &&
+	    ctx->tun.inner_proto != IPPROTO_IPV6)
+		return;
+
 	switch (ctx->ether_type) {
 	case htons(ETH_P_IP):
 		iph = (struct iphdr *)(skb_network_header(skb) + offset);
-		if (ctx->tun.inner_proto == IPPROTO_IPIP) {
-			tuple->tun.dst_v4.s_addr = iph->daddr;
-			tuple->tun.src_v4.s_addr = iph->saddr;
-			tuple->tun.inner_proto = IPPROTO_IPIP;
-		}
+		tuple->tun.dst_v4.s_addr = iph->daddr;
+		tuple->tun.src_v4.s_addr = iph->saddr;
+		tuple->tun.inner_proto = ctx->tun.inner_proto;
 		break;
 	case htons(ETH_P_IPV6):
 		ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
-		if (ctx->tun.inner_proto == IPPROTO_IPV6) {
-			tuple->tun.dst_v6 = ip6h->daddr;
-			tuple->tun.src_v6 = ip6h->saddr;
-			tuple->tun.inner_proto = IPPROTO_IPV6;
-		}
+		tuple->tun.dst_v6 = ip6h->daddr;
+		tuple->tun.src_v6 = ip6h->saddr;
+		tuple->tun.inner_proto = ctx->tun.inner_proto;
 		break;
 	default:
 		break;
-- 
2.47.3