net: dsa: Move skb_unshare() to dsa_switch_rcv()

All DSA tag receive functions need to unshare the skb before mangling it, move
this to the generic dsa_switch_rcv() function which will allow us to make the
tag receive function return their mangled skb without caring about freeing a
NULL skb.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/dsa.c

@@ -906,6 +906,10 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 		return 0;
 	}
 
+	skb = skb_unshare(skb, GFP_ATOMIC);
+	if (!skb)
+		return 0;
+
 	return dst->rcv(skb, dev, pt, orig_dev);
 }
 

net/dsa/tag_brcm.c

@@ -102,10 +102,6 @@ static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	ds = dst->cpu_switch;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (skb == NULL)
-		goto out;
-
 	if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
 		goto out_drop;
 
@@ -151,7 +147,6 @@ static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }
 

net/dsa/tag_dsa.c

@@ -77,10 +77,6 @@ static int dsa_rcv(struct sk_buff *skb, struct net_device *dev,
 	int source_device;
 	int source_port;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (skb == NULL)
-		goto out;
-
 	if (unlikely(!pskb_may_pull(skb, DSA_HLEN)))
 		goto out_drop;
 
@@ -175,7 +171,6 @@ static int dsa_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }
 

net/dsa/tag_edsa.c

@@ -90,10 +90,6 @@ static int edsa_rcv(struct sk_buff *skb, struct net_device *dev,
 	int source_device;
 	int source_port;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (skb == NULL)
-		goto out;
-
 	if (unlikely(!pskb_may_pull(skb, EDSA_HLEN)))
 		goto out_drop;
 
@@ -194,7 +190,6 @@ static int edsa_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }
 

net/dsa/tag_mtk.c

@@ -55,10 +55,6 @@ static int mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	int port;
 	__be16 *phdr, hdr;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (!skb)
-		goto out;
-
 	if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
 		goto out_drop;
 
@@ -105,7 +101,6 @@ static int mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }
 

net/dsa/tag_qca.c

@@ -75,10 +75,6 @@ static int qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	int port;
 	__be16 *phdr, hdr;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (!skb)
-		goto out;
-
 	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
 		goto out_drop;
 
@@ -126,7 +122,6 @@ static int qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }
 

net/dsa/tag_trailer.c

@@ -68,10 +68,6 @@ static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	ds = dst->cpu_switch;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (skb == NULL)
-		goto out;
-
 	if (skb_linearize(skb))
 		goto out_drop;
 
@@ -100,7 +96,6 @@ static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 
 out_drop:
 	kfree_skb(skb);
-out:
 	return 0;
 }