net: Prepare gro for packet consuming gro callbacks

The upcomming IPsec ESP gro callbacks will consume the skb,
so prepare for that.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/linux/netdevice.h

@@ -352,6 +352,7 @@ enum gro_result {
 	GRO_HELD,
 	GRO_NORMAL,
 	GRO_DROP,
+	GRO_CONSUMED,
 };
 typedef enum gro_result gro_result_t;
 
@@ -2661,10 +2662,18 @@ static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
 	remcsum_unadjust((__sum16 *)ptr, grc->delta);
 }
 
+#ifdef CONFIG_XFRM_OFFLOAD
+static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff **pp, int flush)
+{
+	if (PTR_ERR(pp) != -EINPROGRESS)
+		NAPI_GRO_CB(skb)->flush |= flush;
+}
+#else
 static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff **pp, int flush)
 {
 	NAPI_GRO_CB(skb)->flush |= flush;
 }
+#endif
 
 static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 				  unsigned short type,

net/core/dev.c

@@ -4505,6 +4505,11 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
 	if (&ptype->list == head)
 		goto normal;
 
+	if (IS_ERR(pp) && PTR_ERR(pp) == -EINPROGRESS) {
+		ret = GRO_CONSUMED;
+		goto ok;
+	}
+
 	same_flow = NAPI_GRO_CB(skb)->same_flow;
 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
 
@@ -4609,6 +4614,7 @@ static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
 
 	case GRO_HELD:
 	case GRO_MERGED:
+	case GRO_CONSUMED:
 		break;
 	}
 
@@ -4680,6 +4686,7 @@ static gro_result_t napi_frags_finish(struct napi_struct *napi,
 		break;
 
 	case GRO_MERGED:
+	case GRO_CONSUMED:
 		break;
 	}
 

net/xfrm/Kconfig

@@ -5,6 +5,10 @@ config XFRM
        bool
        depends on NET
 
+config XFRM_OFFLOAD
+       bool
+       depends on XFRM
+
 config XFRM_ALGO
 	tristate
 	select XFRM