[Cake] [PATCH for-4.19 2/3] sch_cake: Use tc_skb_protocol() helper for getting packet protocol

[Toke Høiland-Jørgensen]

Commit bbd669a868bba591ffd38b7bc75a7b361bb54b04 upstream.

We shouldn't be using skb->protocol directly as that will miss cases with
hardware-accelerated VLAN tags. Use the helper instead to get the right
protocol number.

Reported-by: Kevin Darbyshire-Bryant <kevin at darbyshire-bryant.me.uk>
Signed-off-by: Toke Høiland-Jørgensen <toke at redhat.com>
---
 net/sched/sch_cake.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 640f00e9f665..de92b5d81ca6 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1512,7 +1512,7 @@ static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
 {
 	u8 dscp;
 
-	switch (skb->protocol) {
+	switch (tc_skb_protocol(skb)) {
 	case htons(ETH_P_IP):
 		dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
 		if (wash && dscp)