1 files changed, 36 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 648c20e19038..45809986dfe1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -7444,3 +7444,39 @@ void __put_netmem(netmem_ref netmem)
 		net_devmem_put_net_iov(netmem_to_net_iov(netmem));
 }
 EXPORT_SYMBOL(__put_netmem);
+
+struct vlan_type_depth __vlan_get_protocol_offset(const struct sk_buff *skb,
+						  __be16 type,
+						  int mac_offset)
+{
+	unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
+
+	/* if type 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 (vlan_depth) {
+		if (WARN_ON_ONCE(vlan_depth < VLAN_HLEN))
+			return (struct vlan_type_depth) { 0 };
+		vlan_depth -= VLAN_HLEN;
+	} else {
+		vlan_depth = ETH_HLEN;
+	}
+	do {
+		struct vlan_hdr vhdr, *vh;
+
+		vh = skb_header_pointer(skb, mac_offset + vlan_depth,
+					sizeof(vhdr), &vhdr);
+		if (unlikely(!vh || !--parse_depth))
+			return (struct vlan_type_depth) { 0 };
+
+		type = vh->h_vlan_encapsulated_proto;
+		vlan_depth += VLAN_HLEN;
+	} while (eth_type_vlan(type));
+
+	return (struct vlan_type_depth) {
+		.type = type,
+		.depth = vlan_depth
+	};
+}
+EXPORT_SYMBOL(__vlan_get_protocol_offset);