[PATCH net-next 02/15] netfilter: flowtable: recognize IPv4/IPv6 in tunnel proto matching

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

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

Allow the flowtable to parse IPv4-in-IPv6 and IPv6-in-IPv4 tunnels by
accepting both IPPROTO_IPIP and IPPROTO_IPV6 as the inner protocol when
walking the outer header in nf_flow_ip4_tunnel_proto() and
nf_flow_ip6_tunnel_proto(). 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 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index c8c29a9a1684..42e8de696474 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -326,7 +326,7 @@ static bool nf_flow_ip4_tunnel_proto(struct nf_flowtable_ctx *ctx,
 	if (iph->ttl <= 1)
 		return false;
 
-	if (iph->protocol == IPPROTO_IPIP) {
+	if (iph->protocol == IPPROTO_IPIP || iph->protocol == IPPROTO_IPV6) {
 		ctx->tun.inner_proto = iph->protocol;
 		ctx->tun.hdr_size = size;
 		ctx->offset += ctx->tun.hdr_size;
@@ -351,7 +351,7 @@ static bool nf_flow_ip6_tunnel_proto(struct nf_flowtable_ctx *ctx,
 	if (ipv6_ext_hdr(ip6h->nexthdr))
 		return false;
 
-	if (ip6h->nexthdr == IPPROTO_IPV6) {
+	if (ip6h->nexthdr == IPPROTO_IPIP || ip6h->nexthdr == IPPROTO_IPV6) {
 		ctx->tun.inner_proto = ip6h->nexthdr;
 		ctx->tun.hdr_size = sizeof(*ip6h);
 		ctx->offset += ctx->tun.hdr_size;
-- 
2.47.3