From:   Josef Miegl <josef@miegl.cz>
Cc:     Josef Miegl <josef@miegl.cz>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] net: geneve: accept every ethertype
Date:   Sun, 26 Feb 2023 22:25:14 +0100
Message-Id: <20230226212514.40875-1-josef@miegl.cz>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
To:     unlisted-recipients:; (no To-header on input)
Precedence: bulk

This patch removes a restriction that prohibited receiving ethertypes
other than IPv4,IPv6 and Ethernet.

With IFLA_GENEVE_INNER_PROTO_INHERIT flag set, GENEVE interface can now
receive ethertypes such as MPLS.

Signed-off-by: Josef Miegl <josef@miegl.cz>
---
 drivers/net/geneve.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 89ff7f8e8c7e..ea48027db580 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -353,7 +353,6 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	struct genevehdr *geneveh;
 	struct geneve_dev *geneve;
 	struct geneve_sock *gs;
-	__be16 inner_proto;
 	int opts_len;
 
 	/* Need UDP and Geneve header to be present */
@@ -365,13 +364,6 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(geneveh->ver != GENEVE_VER))
 		goto drop;
 
-	inner_proto = geneveh->proto_type;
-
-	if (unlikely((inner_proto != htons(ETH_P_TEB) &&
-		      inner_proto != htons(ETH_P_IP) &&
-		      inner_proto != htons(ETH_P_IPV6))))
-		goto drop;
-
 	gs = rcu_dereference_sk_user_data(sk);
 	if (!gs)
 		goto drop;
@@ -381,13 +373,13 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 
 	if (unlikely((!geneve->cfg.inner_proto_inherit &&
-		      inner_proto != htons(ETH_P_TEB)))) {
+		      geneveh->proto_type != htons(ETH_P_TEB)))) {
 		geneve->dev->stats.rx_dropped++;
 		goto drop;
 	}
 
 	opts_len = geneveh->opt_len * 4;
-	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len, inner_proto,
+	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len, geneveh->proto_type,
 				 !net_eq(geneve->net, dev_net(geneve->dev)))) {
 		geneve->dev->stats.rx_dropped++;
 		goto drop;
-- 
2.37.1