datapath: geneve: Handle vlan tag

The compat vlan code ignores vlan tag for inner packet
on egress path. Following patch fixes this by inserting the
tag for inner packet before tunnel encapsulation.

Signed-off-by: Pravin B Shelar <[email protected]>
Acked-by: Joe Stringer <[email protected]>

datapath/linux/compat/geneve.c

@@ -738,6 +738,23 @@ static void geneve_build_header(struct genevehdr *geneveh,
 	memcpy(geneveh->options, options, options_len);
 }
 
+static int push_vlan_tag(struct sk_buff *skb)
+{
+	if (skb_vlan_tag_present(skb)) {
+		__be16 vlan_proto = skb->vlan_proto;
+		int err;
+
+		err = __vlan_insert_tag(skb, skb->vlan_proto,
+					skb_vlan_tag_get(skb));
+
+		if (unlikely(err))
+			return err;
+		skb->vlan_tci = 0;
+		skb->protocol = vlan_proto;
+	}
+	return 0;
+}
+
 static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 			    __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
 			    u32 flags, bool xnet)
@@ -750,11 +767,17 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 	skb_scrub_packet(skb, xnet);
 
 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
-			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr);
+			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
+			+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
+
 	err = skb_cow_head(skb, min_headroom);
 	if (unlikely(err))
 		goto free_rt;
 
+	err = push_vlan_tag(skb);
+	if (unlikely(err))
+		goto free_rt;
+
 	err = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (err)
 		goto free_rt;
@@ -783,11 +806,17 @@ static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 	skb_scrub_packet(skb, xnet);
 
 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len
-			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct ipv6hdr);
+			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct ipv6hdr)
+			+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
+
 	err = skb_cow_head(skb, min_headroom);
 	if (unlikely(err))
 		goto free_dst;
 
+	err = push_vlan_tag(skb);
+	if (unlikely(err))
+		goto free_dst;
+
 	err = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (err)
 		goto free_dst;