net: Fix vlan_get_protocol for stacked vlan
vlan_get_protocol() could not get network protocol if a skb has a 802.1ad
vlan tag or multiple vlans, which caused incorrect checksum calculation
in several drivers.
Fix vlan_get_protocol() to retrieve network protocol instead of incorrect
vlan protocol.
As the logic is the same as skb_network_protocol(), create a common helper
function __vlan_get_protocol() and call it from existing functions.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 171420e..c87a226 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2352,7 +2352,6 @@
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
{
- unsigned int vlan_depth = skb->mac_len;
__be16 type = skb->protocol;
/* Tunnel gso handlers can set protocol to ethernet. */
@@ -2366,35 +2365,7 @@
type = eth->h_proto;
}
- /* if skb->protocol is 802.1Q/AD then the header should already be
- * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
- * ETH_HLEN otherwise
- */
- if (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
- if (vlan_depth) {
- if (WARN_ON(vlan_depth < VLAN_HLEN))
- return 0;
- vlan_depth -= VLAN_HLEN;
- } else {
- vlan_depth = ETH_HLEN;
- }
- do {
- struct vlan_hdr *vh;
-
- if (unlikely(!pskb_may_pull(skb,
- vlan_depth + VLAN_HLEN)))
- return 0;
-
- vh = (struct vlan_hdr *)(skb->data + vlan_depth);
- type = vh->h_vlan_encapsulated_proto;
- vlan_depth += VLAN_HLEN;
- } while (type == htons(ETH_P_8021Q) ||
- type == htons(ETH_P_8021AD));
- }
-
- *depth = vlan_depth;
-
- return type;
+ return __vlan_get_protocol(skb, type, depth);
}
/**