gro: Change all receive functions to return GRO result codes

This will allow drivers to adjust their receive path dynamically
based on whether GRO is being applied successfully.

Currently all in-tree callers ignore the return values of these
functions and do not need to be changed.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 42 insertions, 45 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 71a4870c09a9..153f6b9e722c 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -120,10 +120,12 @@ extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 			     u16 vlan_tci, int polling);
 extern int vlan_hwaccel_do_receive(struct sk_buff *skb);
-extern int vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
-			    unsigned int vlan_tci, struct sk_buff *skb);
-extern int vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
-			  unsigned int vlan_tci);
+extern gro_result_t
+vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
+		 unsigned int vlan_tci, struct sk_buff *skb);
+extern gro_result_t
+vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
+	       unsigned int vlan_tci);
 
 #else
 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
@@ -150,17 +152,18 @@ static inline int vlan_hwaccel_do_receive(struct sk_buff *skb)
 	return 0;
 }
 
-static inline int vlan_gro_receive(struct napi_struct *napi,
-				   struct vlan_group *grp,
-				   unsigned int vlan_tci, struct sk_buff *skb)
+static inline gro_result_t
+vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
+		 unsigned int vlan_tci, struct sk_buff *skb)
 {
-	return NET_RX_DROP;
+	return GRO_DROP;
 }
 
-static inline int vlan_gro_frags(struct napi_struct *napi,
-				 struct vlan_group *grp, unsigned int vlan_tci)
+static inline gro_result_t
+vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
+	       unsigned int vlan_tci)
 {
-	return NET_RX_DROP;
+	return GRO_DROP;
 }
 #endif
 
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 6e777efe149e..193b637889f9 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1483,17 +1483,17 @@ extern int		netif_receive_skb(struct sk_buff *skb);
 extern void		napi_gro_flush(struct napi_struct *napi);
 extern gro_result_t	dev_gro_receive(struct napi_struct *napi,
 					struct sk_buff *skb);
-extern int		napi_skb_finish(gro_result_t ret, struct sk_buff *skb);
-extern int		napi_gro_receive(struct napi_struct *napi,
+extern gro_result_t	napi_skb_finish(gro_result_t ret, struct sk_buff *skb);
+extern gro_result_t	napi_gro_receive(struct napi_struct *napi,
 					 struct sk_buff *skb);
 extern void		napi_reuse_skb(struct napi_struct *napi,
 				       struct sk_buff *skb);
 extern struct sk_buff *	napi_get_frags(struct napi_struct *napi);
-extern int		napi_frags_finish(struct napi_struct *napi,
+extern gro_result_t	napi_frags_finish(struct napi_struct *napi,
 					  struct sk_buff *skb,
 					  gro_result_t ret);
 extern struct sk_buff *	napi_frags_skb(struct napi_struct *napi);
-extern int		napi_gro_frags(struct napi_struct *napi);
+extern gro_result_t	napi_gro_frags(struct napi_struct *napi);
 
 static inline void napi_free_frags(struct napi_struct *napi)
 {
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 47a80d65c3b7..8d5ca2ac4f8d 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -102,11 +102,12 @@ drop:
 	return GRO_DROP;
 }
 
-int vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
-		     unsigned int vlan_tci, struct sk_buff *skb)
+gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
+			      unsigned int vlan_tci, struct sk_buff *skb)
 {
 	if (netpoll_rx_on(skb))
-		return vlan_hwaccel_receive_skb(skb, grp, vlan_tci);
+		return vlan_hwaccel_receive_skb(skb, grp, vlan_tci)
+			? GRO_DROP : GRO_NORMAL;
 
 	skb_gro_reset_offset(skb);
 
@@ -114,17 +115,18 @@ int vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 }
 EXPORT_SYMBOL(vlan_gro_receive);
 
-int vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
-		   unsigned int vlan_tci)
+gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
+			    unsigned int vlan_tci)
 {
 	struct sk_buff *skb = napi_frags_skb(napi);
 
 	if (!skb)
-		return NET_RX_DROP;
+		return GRO_DROP;
 
 	if (netpoll_rx_on(skb)) {
 		skb->protocol = eth_type_trans(skb, skb->dev);
-		return vlan_hwaccel_receive_skb(skb, grp, vlan_tci);
+		return vlan_hwaccel_receive_skb(skb, grp, vlan_tci)
+			? GRO_DROP : GRO_NORMAL;
 	}
 
 	return napi_frags_finish(napi, skb,
diff --git a/net/core/dev.c b/net/core/dev.c
index 1dc13744684c..631cc40da197 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2586,18 +2586,15 @@ __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
 	return dev_gro_receive(napi, skb);
 }
 
-int napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
+gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
 {
-	int err = NET_RX_SUCCESS;
-
 	switch (ret) {
 	case GRO_NORMAL:
-		return netif_receive_skb(skb);
+		if (netif_receive_skb(skb))
+			ret = GRO_DROP;
+		break;
 
 	case GRO_DROP:
-		err = NET_RX_DROP;
-		/* fall through */
-
 	case GRO_MERGED_FREE:
 		kfree_skb(skb);
 		break;
@@ -2607,7 +2604,7 @@ int napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
 		break;
 	}
 
-	return err;
+	return ret;
 }
 EXPORT_SYMBOL(napi_skb_finish);
 
@@ -2627,7 +2624,7 @@ void skb_gro_reset_offset(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(skb_gro_reset_offset);
 
-int napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
+gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
 {
 	skb_gro_reset_offset(skb);
 
@@ -2657,26 +2654,21 @@ struct sk_buff *napi_get_frags(struct napi_struct *napi)
 }
 EXPORT_SYMBOL(napi_get_frags);
 
-int napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
-		      gro_result_t ret)
+gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
+			       gro_result_t ret)
 {
-	int err = NET_RX_SUCCESS;
-
 	switch (ret) {
 	case GRO_NORMAL:
 	case GRO_HELD:
 		skb->protocol = eth_type_trans(skb, napi->dev);
 
-		if (ret == GRO_NORMAL)
-			return netif_receive_skb(skb);
-
-		skb_gro_pull(skb, -ETH_HLEN);
+		if (ret == GRO_HELD)
+			skb_gro_pull(skb, -ETH_HLEN);
+		else if (netif_receive_skb(skb))
+			ret = GRO_DROP;
 		break;
 
 	case GRO_DROP:
-		err = NET_RX_DROP;
-		/* fall through */
-
 	case GRO_MERGED_FREE:
 		napi_reuse_skb(napi, skb);
 		break;
@@ -2685,7 +2677,7 @@ int napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
 		break;
 	}
 
-	return err;
+	return ret;
 }
 EXPORT_SYMBOL(napi_frags_finish);
 
@@ -2726,12 +2718,12 @@ out:
 }
 EXPORT_SYMBOL(napi_frags_skb);
 
-int napi_gro_frags(struct napi_struct *napi)
+gro_result_t napi_gro_frags(struct napi_struct *napi)
 {
 	struct sk_buff *skb = napi_frags_skb(napi);
 
 	if (!skb)
-		return NET_RX_DROP;
+		return GRO_DROP;
 
 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
 }