[PATCH net v2 4/8] wireguard: queueing: make use of ip_tunnel_parse_protocol

[Jason A. Donenfeld]

Now that wg_examine_packet_protocol has been added for general
consumption as ip_tunnel_parse_protocol, it's possible to remove
wg_examine_packet_protocol and simply use the new
ip_tunnel_parse_protocol function directly.

Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
---
 drivers/net/wireguard/queueing.h | 19 ++-----------------
 drivers/net/wireguard/receive.c  |  2 +-
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h
index c58df439dbbe..dfb674e03076 100644
--- a/drivers/net/wireguard/queueing.h
+++ b/drivers/net/wireguard/queueing.h
@@ -11,6 +11,7 @@
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <net/ip_tunnels.h>
 
 struct wg_device;
 struct wg_peer;
@@ -65,25 +66,9 @@ struct packet_cb {
 #define PACKET_CB(skb) ((struct packet_cb *)((skb)->cb))
 #define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer)
 
-/* Returns either the correct skb->protocol value, or 0 if invalid. */
-static inline __be16 wg_examine_packet_protocol(struct sk_buff *skb)
-{
-       if (skb_network_header(skb) >= skb->head &&
-           (skb_network_header(skb) + sizeof(struct iphdr)) <=
-                   skb_tail_pointer(skb) &&
-           ip_hdr(skb)->version == 4)
-               return htons(ETH_P_IP);
-       if (skb_network_header(skb) >= skb->head &&
-           (skb_network_header(skb) + sizeof(struct ipv6hdr)) <=
-                   skb_tail_pointer(skb) &&
-           ipv6_hdr(skb)->version == 6)
-               return htons(ETH_P_IPV6);
-       return 0;
-}
-
 static inline bool wg_check_packet_protocol(struct sk_buff *skb)
 {
-       __be16 real_protocol = wg_examine_packet_protocol(skb);
+       __be16 real_protocol = ip_tunnel_parse_protocol(skb);
        return real_protocol && skb->protocol == real_protocol;
 }
 
diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c
index 9b2ab6fc91cd..2c9551ea6dc7 100644
--- a/drivers/net/wireguard/receive.c
+++ b/drivers/net/wireguard/receive.c
@@ -387,7 +387,7 @@ static void wg_packet_consume_data_done(struct wg_peer 
*peer,
         */
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->csum_level = ~0; /* All levels */
-       skb->protocol = wg_examine_packet_protocol(skb);
+       skb->protocol = ip_tunnel_parse_protocol(skb);
        if (skb->protocol == htons(ETH_P_IP)) {
                len = ntohs(ip_hdr(skb)->tot_len);
                if (unlikely(len < sizeof(struct iphdr)))
-- 
2.27.0