net: rps: support 802.1Q

For the 802.1Q packets, if the NIC doesn't support hw-accel-vlan-rx, RPS
won't inspect the internal 4 tuples to generate skb->rxhash, so this kind
of traffic can't get any benefit from RPS.

This patch adds the support for 802.1Q to RPS.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ead0366ee1e4..be7ee506f17a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2529,6 +2529,7 @@ void __skb_get_rxhash(struct sk_buff *skb)
         int nhoff, hash = 0, poff;
         const struct ipv6hdr *ip6;
         const struct iphdr *ip;
+        const struct vlan_hdr *vlan;
         u8 ip_proto;
         u32 addr1, addr2;
         u16 proto;
@@ -2565,6 +2566,13 @@ again:
                 addr2 = (__force u32) ip6->daddr.s6_addr32[3];
                 nhoff += 40;
                 break;
+        case __constant_htons(ETH_P_8021Q):
+                if (!pskb_may_pull(skb, sizeof(*vlan) + nhoff))
+                        goto done;
+                vlan = (const struct vlan_hdr *) (skb->data + nhoff);
+                proto = vlan->h_vlan_encapsulated_proto;
+                nhoff += sizeof(*vlan);
+                goto again;
         default:
                 goto done;
         }