Merge branch 'gro-out-of-core-files'

Eric Dumazet says:

====================
gro: get out of core files

Move GRO related content into net/core/gro.c
and include/net/gro.h.

This reduces GRO scope to where it is really needed,
and shrinks too big files (include/linux/netdevice.h
and net/core/dev.c)
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

···
 #include <linux/ip.h>
 #include <linux/crash_dump.h>
 #include <net/tcp.h>
+#include <net/gro.h>
 #include <net/ipv6.h>
 #include <net/ip6_checksum.h>
 #include <linux/prefetch.h>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

···
 #include <linux/if_bridge.h>
 #include <linux/rtc.h>
 #include <linux/bpf.h>
+#include <net/gro.h>
 #include <net/ip.h>
 #include <net/tcp.h>
 #include <net/udp.h>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

···
 #include <linux/skbuff.h>
 #include <linux/sctp.h>
 #include <net/gre.h>
+#include <net/gro.h>
 #include <net/ip6_checksum.h>
 #include <net/pkt_cls.h>
 #include <net/tcp.h>

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

···
 #include <net/ip6_checksum.h>
 #include <net/page_pool.h>
 #include <net/inet_ecn.h>
+#include <net/gro.h>
 #include <net/udp.h>
 #include <net/tcp.h>
 #include "en.h"

drivers/net/ethernet/qlogic/qede/qede_fp.c

···
 #include <linux/bpf_trace.h>
 #include <net/udp_tunnel.h>
 #include <linux/ip.h>
+#include <net/gro.h>
 #include <net/ipv6.h>
 #include <net/tcp.h>
 #include <linux/if_ether.h>

drivers/net/geneve.c

···
 #include <net/gro_cells.h>
 #include <net/rtnetlink.h>
 #include <net/geneve.h>
+#include <net/gro.h>
 #include <net/protocol.h>
 
 #define GENEVE_NETDEV_VER	"0.6"

drivers/net/vxlan.c

···
 #include <linux/ethtool.h>
 #include <net/arp.h>
 #include <net/ndisc.h>
+#include <net/gro.h>
 #include <net/ipv6_stubs.h>
 #include <net/ip.h>
 #include <net/icmp.h>

include/linux/netdevice.h

···
 	synchronize_net();
 }
 
-struct napi_gro_cb {
-	/* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
-	void	*frag0;
-
-	/* Length of frag0. */
-	unsigned int frag0_len;
-
-	/* This indicates where we are processing relative to skb->data. */
-	int	data_offset;
-
-	/* This is non-zero if the packet cannot be merged with the new skb. */
-	u16	flush;
-
-	/* Save the IP ID here and check when we get to the transport layer */
-	u16	flush_id;
-
-	/* Number of segments aggregated. */
-	u16	count;
-
-	/* Start offset for remote checksum offload */
-	u16	gro_remcsum_start;
-
-	/* jiffies when first packet was created/queued */
-	unsigned long age;
-
-	/* Used in ipv6_gro_receive() and foo-over-udp */
-	u16	proto;
-
-	/* This is non-zero if the packet may be of the same flow. */
-	u8	same_flow:1;
-
-	/* Used in tunnel GRO receive */
-	u8	encap_mark:1;
-
-	/* GRO checksum is valid */
-	u8	csum_valid:1;
-
-	/* Number of checksums via CHECKSUM_UNNECESSARY */
-	u8	csum_cnt:3;
-
-	/* Free the skb? */
-	u8	free:2;
-#define NAPI_GRO_FREE		  1
-#define NAPI_GRO_FREE_STOLEN_HEAD 2
-
-	/* Used in foo-over-udp, set in udp[46]_gro_receive */
-	u8	is_ipv6:1;
-
-	/* Used in GRE, set in fou/gue_gro_receive */
-	u8	is_fou:1;
-
-	/* Used to determine if flush_id can be ignored */
-	u8	is_atomic:1;
-
-	/* Number of gro_receive callbacks this packet already went through */
-	u8 recursion_counter:4;
-
-	/* GRO is done by frag_list pointer chaining. */
-	u8	is_flist:1;
-
-	/* used to support CHECKSUM_COMPLETE for tunneling protocols */
-	__wsum	csum;
-
-	/* used in skb_gro_receive() slow path */
-	struct sk_buff *last;
-};
-
-#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
-
-#define GRO_RECURSION_LIMIT 15
-static inline int gro_recursion_inc_test(struct sk_buff *skb)
-{
-	return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
-}
-
-typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
-static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
-					       struct list_head *head,
-					       struct sk_buff *skb)
-{
-	if (unlikely(gro_recursion_inc_test(skb))) {
-		NAPI_GRO_CB(skb)->flush |= 1;
-		return NULL;
-	}
-
-	return cb(head, skb);
-}
-
-typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
-					    struct sk_buff *);
-static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
-						  struct sock *sk,
-						  struct list_head *head,
-						  struct sk_buff *skb)
-{
-	if (unlikely(gro_recursion_inc_test(skb))) {
-		NAPI_GRO_CB(skb)->flush |= 1;
-		return NULL;
-	}
-
-	return cb(sk, head, skb);
-}
-
 struct packet_type {
 	__be16			type;	/* This is really htons(ether_type). */
 	bool			ignore_outgoing;
···
 struct net_device *dev_get_by_napi_id(unsigned int napi_id);
 int netdev_get_name(struct net *net, char *name, int ifindex);
 int dev_restart(struct net_device *dev);
-int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
-int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb);
 
-static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
-{
-	return NAPI_GRO_CB(skb)->data_offset;
-}
-
-static inline unsigned int skb_gro_len(const struct sk_buff *skb)
-{
-	return skb->len - NAPI_GRO_CB(skb)->data_offset;
-}
-
-static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
-{
-	NAPI_GRO_CB(skb)->data_offset += len;
-}
-
-static inline void *skb_gro_header_fast(struct sk_buff *skb,
-					unsigned int offset)
-{
-	return NAPI_GRO_CB(skb)->frag0 + offset;
-}
-
-static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
-{
-	return NAPI_GRO_CB(skb)->frag0_len < hlen;
-}
-
-static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
-{
-	NAPI_GRO_CB(skb)->frag0 = NULL;
-	NAPI_GRO_CB(skb)->frag0_len = 0;
-}
-
-static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
-					unsigned int offset)
-{
-	if (!pskb_may_pull(skb, hlen))
-		return NULL;
-
-	skb_gro_frag0_invalidate(skb);
-	return skb->data + offset;
-}
-
-static inline void *skb_gro_network_header(struct sk_buff *skb)
-{
-	return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
-	       skb_network_offset(skb);
-}
-
-static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
-					const void *start, unsigned int len)
-{
-	if (NAPI_GRO_CB(skb)->csum_valid)
-		NAPI_GRO_CB(skb)->csum = csum_sub(NAPI_GRO_CB(skb)->csum,
-						  csum_partial(start, len, 0));
-}
-
-/* GRO checksum functions. These are logical equivalents of the normal
- * checksum functions (in skbuff.h) except that they operate on the GRO
- * offsets and fields in sk_buff.
- */
-
-__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
-
-static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
-{
-	return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
-}
-
-static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
-						      bool zero_okay,
-						      __sum16 check)
-{
-	return ((skb->ip_summed != CHECKSUM_PARTIAL ||
-		skb_checksum_start_offset(skb) <
-		 skb_gro_offset(skb)) &&
-		!skb_at_gro_remcsum_start(skb) &&
-		NAPI_GRO_CB(skb)->csum_cnt == 0 &&
-		(!zero_okay || check));
-}
-
-static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
-							   __wsum psum)
-{
-	if (NAPI_GRO_CB(skb)->csum_valid &&
-	    !csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
-		return 0;
-
-	NAPI_GRO_CB(skb)->csum = psum;
-
-	return __skb_gro_checksum_complete(skb);
-}
-
-static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
-{
-	if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
-		/* Consume a checksum from CHECKSUM_UNNECESSARY */
-		NAPI_GRO_CB(skb)->csum_cnt--;
-	} else {
-		/* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
-		 * verified a new top level checksum or an encapsulated one
-		 * during GRO. This saves work if we fallback to normal path.
-		 */
-		__skb_incr_checksum_unnecessary(skb);
-	}
-}
-
-#define __skb_gro_checksum_validate(skb, proto, zero_okay, check,	\
-				    compute_pseudo)			\
-({									\
-	__sum16 __ret = 0;						\
-	if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))	\
-		__ret = __skb_gro_checksum_validate_complete(skb,	\
-				compute_pseudo(skb, proto));		\
-	if (!__ret)							\
-		skb_gro_incr_csum_unnecessary(skb);			\
-	__ret;								\
-})
-
-#define skb_gro_checksum_validate(skb, proto, compute_pseudo)		\
-	__skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
-
-#define skb_gro_checksum_validate_zero_check(skb, proto, check,		\
-					     compute_pseudo)		\
-	__skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
-
-#define skb_gro_checksum_simple_validate(skb)				\
-	__skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
-
-static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
-{
-	return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
-		!NAPI_GRO_CB(skb)->csum_valid);
-}
-
-static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
-					      __wsum pseudo)
-{
-	NAPI_GRO_CB(skb)->csum = ~pseudo;
-	NAPI_GRO_CB(skb)->csum_valid = 1;
-}
-
-#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo)	\
-do {									\
-	if (__skb_gro_checksum_convert_check(skb))			\
-		__skb_gro_checksum_convert(skb, 			\
-					   compute_pseudo(skb, proto));	\
-} while (0)
-
-struct gro_remcsum {
-	int offset;
-	__wsum delta;
-};
-
-static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
-{
-	grc->offset = 0;
-	grc->delta = 0;
-}
-
-static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
-					    unsigned int off, size_t hdrlen,
-					    int start, int offset,
-					    struct gro_remcsum *grc,
-					    bool nopartial)
-{
-	__wsum delta;
-	size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);
-
-	BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);
-
-	if (!nopartial) {
-		NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
-		return ptr;
-	}
-
-	ptr = skb_gro_header_fast(skb, off);
-	if (skb_gro_header_hard(skb, off + plen)) {
-		ptr = skb_gro_header_slow(skb, off + plen, off);
-		if (!ptr)
-			return NULL;
-	}
-
-	delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
-			       start, offset);
-
-	/* Adjust skb->csum since we changed the packet */
-	NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);
-
-	grc->offset = off + hdrlen + offset;
-	grc->delta = delta;
-
-	return ptr;
-}
-
-static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
-					   struct gro_remcsum *grc)
-{
-	void *ptr;
-	size_t plen = grc->offset + sizeof(u16);
-
-	if (!grc->delta)
-		return;
-
-	ptr = skb_gro_header_fast(skb, grc->offset);
-	if (skb_gro_header_hard(skb, grc->offset + sizeof(u16))) {
-		ptr = skb_gro_header_slow(skb, plen, grc->offset);
-		if (!ptr)
-			return;
-	}
-
-	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;
-}
-static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
-					       struct sk_buff *pp,
-					       int flush,
-					       struct gro_remcsum *grc)
-{
-	if (PTR_ERR(pp) != -EINPROGRESS) {
-		NAPI_GRO_CB(skb)->flush |= flush;
-		skb_gro_remcsum_cleanup(skb, grc);
-		skb->remcsum_offload = 0;
-	}
-}
-#else
-static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
-{
-	NAPI_GRO_CB(skb)->flush |= flush;
-}
-static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
-					       struct sk_buff *pp,
-					       int flush,
-					       struct gro_remcsum *grc)
-{
-	NAPI_GRO_CB(skb)->flush |= flush;
-	skb_gro_remcsum_cleanup(skb, grc);
-	skb->remcsum_offload = 0;
-}
-#endif
 
 static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 				  unsigned short type,
···
 int netif_rx_any_context(struct sk_buff *skb);
 int netif_receive_skb(struct sk_buff *skb);
 int netif_receive_skb_core(struct sk_buff *skb);
+void netif_receive_skb_list_internal(struct list_head *head);
 void netif_receive_skb_list(struct list_head *head);
 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb);
 void napi_gro_flush(struct napi_struct *napi, bool flush_old);

include/net/gro.h

···
 #define _NET_IPV6_GRO_H
 
 #include <linux/indirect_call_wrapper.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/skbuff.h>
+#include <net/udp.h>
 
-struct list_head;
-struct sk_buff;
+struct napi_gro_cb {
+	/* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
+	void	*frag0;
+
+	/* Length of frag0. */
+	unsigned int frag0_len;
+
+	/* This indicates where we are processing relative to skb->data. */
+	int	data_offset;
+
+	/* This is non-zero if the packet cannot be merged with the new skb. */
+	u16	flush;
+
+	/* Save the IP ID here and check when we get to the transport layer */
+	u16	flush_id;
+
+	/* Number of segments aggregated. */
+	u16	count;
+
+	/* Start offset for remote checksum offload */
+	u16	gro_remcsum_start;
+
+	/* jiffies when first packet was created/queued */
+	unsigned long age;
+
+	/* Used in ipv6_gro_receive() and foo-over-udp */
+	u16	proto;
+
+	/* This is non-zero if the packet may be of the same flow. */
+	u8	same_flow:1;
+
+	/* Used in tunnel GRO receive */
+	u8	encap_mark:1;
+
+	/* GRO checksum is valid */
+	u8	csum_valid:1;
+
+	/* Number of checksums via CHECKSUM_UNNECESSARY */
+	u8	csum_cnt:3;
+
+	/* Free the skb? */
+	u8	free:2;
+#define NAPI_GRO_FREE		  1
+#define NAPI_GRO_FREE_STOLEN_HEAD 2
+
+	/* Used in foo-over-udp, set in udp[46]_gro_receive */
+	u8	is_ipv6:1;
+
+	/* Used in GRE, set in fou/gue_gro_receive */
+	u8	is_fou:1;
+
+	/* Used to determine if flush_id can be ignored */
+	u8	is_atomic:1;
+
+	/* Number of gro_receive callbacks this packet already went through */
+	u8 recursion_counter:4;
+
+	/* GRO is done by frag_list pointer chaining. */
+	u8	is_flist:1;
+
+	/* used to support CHECKSUM_COMPLETE for tunneling protocols */
+	__wsum	csum;
+
+	/* used in skb_gro_receive() slow path */
+	struct sk_buff *last;
+};
+
+#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
+
+#define GRO_RECURSION_LIMIT 15
+static inline int gro_recursion_inc_test(struct sk_buff *skb)
+{
+	return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
+}
+
+typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
+static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
+					       struct list_head *head,
+					       struct sk_buff *skb)
+{
+	if (unlikely(gro_recursion_inc_test(skb))) {
+		NAPI_GRO_CB(skb)->flush |= 1;
+		return NULL;
+	}
+
+	return cb(head, skb);
+}
+
+typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
+					    struct sk_buff *);
+static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
+						  struct sock *sk,
+						  struct list_head *head,
+						  struct sk_buff *skb)
+{
+	if (unlikely(gro_recursion_inc_test(skb))) {
+		NAPI_GRO_CB(skb)->flush |= 1;
+		return NULL;
+	}
+
+	return cb(sk, head, skb);
+}
+
+static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
+{
+	return NAPI_GRO_CB(skb)->data_offset;
+}
+
+static inline unsigned int skb_gro_len(const struct sk_buff *skb)
+{
+	return skb->len - NAPI_GRO_CB(skb)->data_offset;
+}
+
+static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
+{
+	NAPI_GRO_CB(skb)->data_offset += len;
+}
+
+static inline void *skb_gro_header_fast(struct sk_buff *skb,
+					unsigned int offset)
+{
+	return NAPI_GRO_CB(skb)->frag0 + offset;
+}
+
+static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
+{
+	return NAPI_GRO_CB(skb)->frag0_len < hlen;
+}
+
+static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
+{
+	NAPI_GRO_CB(skb)->frag0 = NULL;
+	NAPI_GRO_CB(skb)->frag0_len = 0;
+}
+
+static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
+					unsigned int offset)
+{
+	if (!pskb_may_pull(skb, hlen))
+		return NULL;
+
+	skb_gro_frag0_invalidate(skb);
+	return skb->data + offset;
+}
+
+static inline void *skb_gro_network_header(struct sk_buff *skb)
+{
+	return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
+	       skb_network_offset(skb);
+}
+
+static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	const struct iphdr *iph = skb_gro_network_header(skb);
+
+	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
+				  skb_gro_len(skb), proto, 0);
+}
+
+static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
+					const void *start, unsigned int len)
+{
+	if (NAPI_GRO_CB(skb)->csum_valid)
+		NAPI_GRO_CB(skb)->csum = csum_sub(NAPI_GRO_CB(skb)->csum,
+						  csum_partial(start, len, 0));
+}
+
+/* GRO checksum functions. These are logical equivalents of the normal
+ * checksum functions (in skbuff.h) except that they operate on the GRO
+ * offsets and fields in sk_buff.
+ */
+
+__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
+
+static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
+{
+	return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
+}
+
+static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
+						      bool zero_okay,
+						      __sum16 check)
+{
+	return ((skb->ip_summed != CHECKSUM_PARTIAL ||
+		skb_checksum_start_offset(skb) <
+		 skb_gro_offset(skb)) &&
+		!skb_at_gro_remcsum_start(skb) &&
+		NAPI_GRO_CB(skb)->csum_cnt == 0 &&
+		(!zero_okay || check));
+}
+
+static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
+							   __wsum psum)
+{
+	if (NAPI_GRO_CB(skb)->csum_valid &&
+	    !csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
+		return 0;
+
+	NAPI_GRO_CB(skb)->csum = psum;
+
+	return __skb_gro_checksum_complete(skb);
+}
+
+static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
+{
+	if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
+		/* Consume a checksum from CHECKSUM_UNNECESSARY */
+		NAPI_GRO_CB(skb)->csum_cnt--;
+	} else {
+		/* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
+		 * verified a new top level checksum or an encapsulated one
+		 * during GRO. This saves work if we fallback to normal path.
+		 */
+		__skb_incr_checksum_unnecessary(skb);
+	}
+}
+
+#define __skb_gro_checksum_validate(skb, proto, zero_okay, check,	\
+				    compute_pseudo)			\
+({									\
+	__sum16 __ret = 0;						\
+	if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))	\
+		__ret = __skb_gro_checksum_validate_complete(skb,	\
+				compute_pseudo(skb, proto));		\
+	if (!__ret)							\
+		skb_gro_incr_csum_unnecessary(skb);			\
+	__ret;								\
+})
+
+#define skb_gro_checksum_validate(skb, proto, compute_pseudo)		\
+	__skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
+
+#define skb_gro_checksum_validate_zero_check(skb, proto, check,		\
+					     compute_pseudo)		\
+	__skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
+
+#define skb_gro_checksum_simple_validate(skb)				\
+	__skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
+
+static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
+{
+	return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
+		!NAPI_GRO_CB(skb)->csum_valid);
+}
+
+static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
+					      __wsum pseudo)
+{
+	NAPI_GRO_CB(skb)->csum = ~pseudo;
+	NAPI_GRO_CB(skb)->csum_valid = 1;
+}
+
+#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo)	\
+do {									\
+	if (__skb_gro_checksum_convert_check(skb))			\
+		__skb_gro_checksum_convert(skb, 			\
+					   compute_pseudo(skb, proto));	\
+} while (0)
+
+struct gro_remcsum {
+	int offset;
+	__wsum delta;
+};
+
+static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
+{
+	grc->offset = 0;
+	grc->delta = 0;
+}
+
+static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
+					    unsigned int off, size_t hdrlen,
+					    int start, int offset,
+					    struct gro_remcsum *grc,
+					    bool nopartial)
+{
+	__wsum delta;
+	size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);
+
+	BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);
+
+	if (!nopartial) {
+		NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
+		return ptr;
+	}
+
+	ptr = skb_gro_header_fast(skb, off);
+	if (skb_gro_header_hard(skb, off + plen)) {
+		ptr = skb_gro_header_slow(skb, off + plen, off);
+		if (!ptr)
+			return NULL;
+	}
+
+	delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
+			       start, offset);
+
+	/* Adjust skb->csum since we changed the packet */
+	NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);
+
+	grc->offset = off + hdrlen + offset;
+	grc->delta = delta;
+
+	return ptr;
+}
+
+static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
+					   struct gro_remcsum *grc)
+{
+	void *ptr;
+	size_t plen = grc->offset + sizeof(u16);
+
+	if (!grc->delta)
+		return;
+
+	ptr = skb_gro_header_fast(skb, grc->offset);
+	if (skb_gro_header_hard(skb, grc->offset + sizeof(u16))) {
+		ptr = skb_gro_header_slow(skb, plen, grc->offset);
+		if (!ptr)
+			return;
+	}
+
+	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;
+}
+static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
+					       struct sk_buff *pp,
+					       int flush,
+					       struct gro_remcsum *grc)
+{
+	if (PTR_ERR(pp) != -EINPROGRESS) {
+		NAPI_GRO_CB(skb)->flush |= flush;
+		skb_gro_remcsum_cleanup(skb, grc);
+		skb->remcsum_offload = 0;
+	}
+}
+#else
+static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
+{
+	NAPI_GRO_CB(skb)->flush |= flush;
+}
+static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
+					       struct sk_buff *pp,
+					       int flush,
+					       struct gro_remcsum *grc)
+{
+	NAPI_GRO_CB(skb)->flush |= flush;
+	skb_gro_remcsum_cleanup(skb, grc);
+	skb->remcsum_offload = 0;
+}
+#endif
 
 INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
 							   struct sk_buff *));
···
 							   struct sk_buff *));
 INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
 
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
+							   struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
+
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
+							   struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
+
 #define indirect_call_gro_receive_inet(cb, f2, f1, head, skb)	\
 ({								\
 	unlikely(gro_recursion_inc_test(skb)) ?			\
 		NAPI_GRO_CB(skb)->flush |= 1, NULL :		\
 		INDIRECT_CALL_INET(cb, f2, f1, head, skb);	\
 })
+
+struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
+				struct udphdr *uh, struct sock *sk);
+int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
+
+static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
+{
+	struct udphdr *uh;
+	unsigned int hlen, off;
+
+	off  = skb_gro_offset(skb);
+	hlen = off + sizeof(*uh);
+	uh   = skb_gro_header_fast(skb, off);
+	if (skb_gro_header_hard(skb, hlen))
+		uh = skb_gro_header_slow(skb, hlen, off);
+
+	return uh;
+}
+
+static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+
+	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
+					    skb_gro_len(skb), proto, 0));
+}
+
+int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
+
+/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
+static inline void gro_normal_list(struct napi_struct *napi)
+{
+	if (!napi->rx_count)
+		return;
+	netif_receive_skb_list_internal(&napi->rx_list);
+	INIT_LIST_HEAD(&napi->rx_list);
+	napi->rx_count = 0;
+}
+
+/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
+ * pass the whole batch up to the stack.
+ */
+static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
+{
+	list_add_tail(&skb->list, &napi->rx_list);
+	napi->rx_count += segs;
+	if (napi->rx_count >= gro_normal_batch)
+		gro_normal_list(napi);
+}
+
 
 #endif /* _NET_IPV6_GRO_H */

include/net/ip.h

···
 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 }
 
-static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
-{
-	const struct iphdr *iph = skb_gro_network_header(skb);
-
-	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
-				  skb_gro_len(skb), proto, 0);
-}
-
 /*
  *	Map a multicast IP onto multicast MAC for type ethernet.
  */

include/net/ip6_checksum.h

···
 					    skb->len, proto, 0));
 }
 
-static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
-{
-	const struct ipv6hdr *iph = skb_gro_network_header(skb);
-
-	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
-					    skb_gro_len(skb), proto, 0));
-}
-
 static __inline__ __sum16 tcp_v6_check(int len,
 				   const struct in6_addr *saddr,
 				   const struct in6_addr *daddr,

include/net/udp.h

···
 typedef struct sock *(*udp_lookup_t)(const struct sk_buff *skb, __be16 sport,
 				     __be16 dport);
 
-INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
-							   struct sk_buff *));
-INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
-INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
-							   struct sk_buff *));
-INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
 INDIRECT_CALLABLE_DECLARE(void udp_v6_early_demux(struct sk_buff *));
 INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *));
 
-struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
-				struct udphdr *uh, struct sock *sk);
-int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
-
 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 				  netdev_features_t features, bool is_ipv6);
-
-static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
-{
-	struct udphdr *uh;
-	unsigned int hlen, off;
-
-	off  = skb_gro_offset(skb);
-	hlen = off + sizeof(*uh);
-	uh   = skb_gro_header_fast(skb, off);
-	if (skb_gro_header_hard(skb, hlen))
-		uh = skb_gro_header_slow(skb, hlen, off);
-
-	return uh;
-}
 
 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 static inline int udp_lib_hash(struct sock *sk)

net/core/Makefile

···
 obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
 			neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
 			sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \
-			fib_notifier.o xdp.o flow_offload.o
+			fib_notifier.o xdp.o flow_offload.o gro.o
 
 obj-y += net-sysfs.o
 obj-$(CONFIG_PAGE_POOL) += page_pool.o

net/core/dev.c

···
 
 #include "net-sysfs.h"
 
-#define MAX_GRO_SKBS 8
-
-/* This should be increased if a protocol with a bigger head is added. */
-#define GRO_MAX_HEAD (MAX_HEADER + 128)
 
 static DEFINE_SPINLOCK(ptype_lock);
-static DEFINE_SPINLOCK(offload_lock);
 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 struct list_head ptype_all __read_mostly;	/* Taps */
-static struct list_head offload_base __read_mostly;
 
 static int netif_rx_internal(struct sk_buff *skb);
 static int call_netdevice_notifiers_info(unsigned long val,
···
 }
 EXPORT_SYMBOL(dev_remove_pack);
 
-
-/**
- *	dev_add_offload - register offload handlers
- *	@po: protocol offload declaration
- *
- *	Add protocol offload handlers to the networking stack. The passed
- *	&proto_offload is linked into kernel lists and may not be freed until
- *	it has been removed from the kernel lists.
- *
- *	This call does not sleep therefore it can not
- *	guarantee all CPU's that are in middle of receiving packets
- *	will see the new offload handlers (until the next received packet).
- */
-void dev_add_offload(struct packet_offload *po)
-{
-	struct packet_offload *elem;
-
-	spin_lock(&offload_lock);
-	list_for_each_entry(elem, &offload_base, list) {
-		if (po->priority < elem->priority)
-			break;
-	}
-	list_add_rcu(&po->list, elem->list.prev);
-	spin_unlock(&offload_lock);
-}
-EXPORT_SYMBOL(dev_add_offload);
-
-/**
- *	__dev_remove_offload	 - remove offload handler
- *	@po: packet offload declaration
- *
- *	Remove a protocol offload handler that was previously added to the
- *	kernel offload handlers by dev_add_offload(). The passed &offload_type
- *	is removed from the kernel lists and can be freed or reused once this
- *	function returns.
- *
- *      The packet type might still be in use by receivers
- *	and must not be freed until after all the CPU's have gone
- *	through a quiescent state.
- */
-static void __dev_remove_offload(struct packet_offload *po)
-{
-	struct list_head *head = &offload_base;
-	struct packet_offload *po1;
-
-	spin_lock(&offload_lock);
-
-	list_for_each_entry(po1, head, list) {
-		if (po == po1) {
-			list_del_rcu(&po->list);
-			goto out;
-		}
-	}
-
-	pr_warn("dev_remove_offload: %p not found\n", po);
-out:
-	spin_unlock(&offload_lock);
-}
-
-/**
- *	dev_remove_offload	 - remove packet offload handler
- *	@po: packet offload declaration
- *
- *	Remove a packet offload handler that was previously added to the kernel
- *	offload handlers by dev_add_offload(). The passed &offload_type is
- *	removed from the kernel lists and can be freed or reused once this
- *	function returns.
- *
- *	This call sleeps to guarantee that no CPU is looking at the packet
- *	type after return.
- */
-void dev_remove_offload(struct packet_offload *po)
-{
-	__dev_remove_offload(po);
-
-	synchronize_net();
-}
-EXPORT_SYMBOL(dev_remove_offload);
 
 /*******************************************************************************
  *
···
 	return __vlan_get_protocol(skb, type, depth);
 }
 
-/**
- *	skb_mac_gso_segment - mac layer segmentation handler.
- *	@skb: buffer to segment
- *	@features: features for the output path (see dev->features)
- */
-struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
-				    netdev_features_t features)
-{
-	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
-	struct packet_offload *ptype;
-	int vlan_depth = skb->mac_len;
-	__be16 type = skb_network_protocol(skb, &vlan_depth);
-
-	if (unlikely(!type))
-		return ERR_PTR(-EINVAL);
-
-	__skb_pull(skb, vlan_depth);
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(ptype, &offload_base, list) {
-		if (ptype->type == type && ptype->callbacks.gso_segment) {
-			segs = ptype->callbacks.gso_segment(skb, features);
-			break;
-		}
-	}
-	rcu_read_unlock();
-
-	__skb_push(skb, skb->data - skb_mac_header(skb));
-
-	return segs;
-}
-EXPORT_SYMBOL(skb_mac_gso_segment);
-
-
 /* openvswitch calls this on rx path, so we need a different check.
  */
 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
···
 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
 int dev_rx_weight __read_mostly = 64;
 int dev_tx_weight __read_mostly = 64;
-/* Maximum number of GRO_NORMAL skbs to batch up for list-RX */
-int gro_normal_batch __read_mostly = 8;
 
 /* Called with irq disabled */
 static inline void ____napi_schedule(struct softnet_data *sd,
···
 	return ret;
 }
 
-static void netif_receive_skb_list_internal(struct list_head *head)
+void netif_receive_skb_list_internal(struct list_head *head)
 {
 	struct sk_buff *skb, *next;
 	struct list_head sublist;
···
 
 	cpus_read_unlock();
 }
-
-/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
-static void gro_normal_list(struct napi_struct *napi)
-{
-	if (!napi->rx_count)
-		return;
-	netif_receive_skb_list_internal(&napi->rx_list);
-	INIT_LIST_HEAD(&napi->rx_list);
-	napi->rx_count = 0;
-}
-
-/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
- * pass the whole batch up to the stack.
- */
-static void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
-{
-	list_add_tail(&skb->list, &napi->rx_list);
-	napi->rx_count += segs;
-	if (napi->rx_count >= gro_normal_batch)
-		gro_normal_list(napi);
-}
-
-static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
-{
-	struct packet_offload *ptype;
-	__be16 type = skb->protocol;
-	struct list_head *head = &offload_base;
-	int err = -ENOENT;
-
-	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
-
-	if (NAPI_GRO_CB(skb)->count == 1) {
-		skb_shinfo(skb)->gso_size = 0;
-		goto out;
-	}
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(ptype, head, list) {
-		if (ptype->type != type || !ptype->callbacks.gro_complete)
-			continue;
-
-		err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
-					 ipv6_gro_complete, inet_gro_complete,
-					 skb, 0);
-		break;
-	}
-	rcu_read_unlock();
-
-	if (err) {
-		WARN_ON(&ptype->list == head);
-		kfree_skb(skb);
-		return;
-	}
-
-out:
-	gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count);
-}
-
-static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
-				   bool flush_old)
-{
-	struct list_head *head = &napi->gro_hash[index].list;
-	struct sk_buff *skb, *p;
-
-	list_for_each_entry_safe_reverse(skb, p, head, list) {
-		if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
-			return;
-		skb_list_del_init(skb);
-		napi_gro_complete(napi, skb);
-		napi->gro_hash[index].count--;
-	}
-
-	if (!napi->gro_hash[index].count)
-		__clear_bit(index, &napi->gro_bitmask);
-}
-
-/* napi->gro_hash[].list contains packets ordered by age.
- * youngest packets at the head of it.
- * Complete skbs in reverse order to reduce latencies.
- */
-void napi_gro_flush(struct napi_struct *napi, bool flush_old)
-{
-	unsigned long bitmask = napi->gro_bitmask;
-	unsigned int i, base = ~0U;
-
-	while ((i = ffs(bitmask)) != 0) {
-		bitmask >>= i;
-		base += i;
-		__napi_gro_flush_chain(napi, base, flush_old);
-	}
-}
-EXPORT_SYMBOL(napi_gro_flush);
-
-static void gro_list_prepare(const struct list_head *head,
-			     const struct sk_buff *skb)
-{
-	unsigned int maclen = skb->dev->hard_header_len;
-	u32 hash = skb_get_hash_raw(skb);
-	struct sk_buff *p;
-
-	list_for_each_entry(p, head, list) {
-		unsigned long diffs;
-
-		NAPI_GRO_CB(p)->flush = 0;
-
-		if (hash != skb_get_hash_raw(p)) {
-			NAPI_GRO_CB(p)->same_flow = 0;
-			continue;
-		}
-
-		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
-		diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
-		if (skb_vlan_tag_present(p))
-			diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb);
-		diffs |= skb_metadata_differs(p, skb);
-		if (maclen == ETH_HLEN)
-			diffs |= compare_ether_header(skb_mac_header(p),
-						      skb_mac_header(skb));
-		else if (!diffs)
-			diffs = memcmp(skb_mac_header(p),
-				       skb_mac_header(skb),
-				       maclen);
-
-		/* in most common scenarions 'slow_gro' is 0
-		 * otherwise we are already on some slower paths
-		 * either skip all the infrequent tests altogether or
-		 * avoid trying too hard to skip each of them individually
-		 */
-		if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) {
-#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
-			struct tc_skb_ext *skb_ext;
-			struct tc_skb_ext *p_ext;
-#endif
-
-			diffs |= p->sk != skb->sk;
-			diffs |= skb_metadata_dst_cmp(p, skb);
-			diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
-
-#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
-			skb_ext = skb_ext_find(skb, TC_SKB_EXT);
-			p_ext = skb_ext_find(p, TC_SKB_EXT);
-
-			diffs |= (!!p_ext) ^ (!!skb_ext);
-			if (!diffs && unlikely(skb_ext))
-				diffs |= p_ext->chain ^ skb_ext->chain;
-#endif
-		}
-
-		NAPI_GRO_CB(p)->same_flow = !diffs;
-	}
-}
-
-static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
-{
-	const struct skb_shared_info *pinfo = skb_shinfo(skb);
-	const skb_frag_t *frag0 = &pinfo->frags[0];
-
-	NAPI_GRO_CB(skb)->data_offset = 0;
-	NAPI_GRO_CB(skb)->frag0 = NULL;
-	NAPI_GRO_CB(skb)->frag0_len = 0;
-
-	if (!skb_headlen(skb) && pinfo->nr_frags &&
-	    !PageHighMem(skb_frag_page(frag0)) &&
-	    (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
-		NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
-		NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
-						    skb_frag_size(frag0),
-						    skb->end - skb->tail);
-	}
-}
-
-static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
-{
-	struct skb_shared_info *pinfo = skb_shinfo(skb);
-
-	BUG_ON(skb->end - skb->tail < grow);
-
-	memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
-
-	skb->data_len -= grow;
-	skb->tail += grow;
-
-	skb_frag_off_add(&pinfo->frags[0], grow);
-	skb_frag_size_sub(&pinfo->frags[0], grow);
-
-	if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
-		skb_frag_unref(skb, 0);
-		memmove(pinfo->frags, pinfo->frags + 1,
-			--pinfo->nr_frags * sizeof(pinfo->frags[0]));
-	}
-}
-
-static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head)
-{
-	struct sk_buff *oldest;
-
-	oldest = list_last_entry(head, struct sk_buff, list);
-
-	/* We are called with head length >= MAX_GRO_SKBS, so this is
-	 * impossible.
-	 */
-	if (WARN_ON_ONCE(!oldest))
-		return;
-
-	/* Do not adjust napi->gro_hash[].count, caller is adding a new
-	 * SKB to the chain.
-	 */
-	skb_list_del_init(oldest);
-	napi_gro_complete(napi, oldest);
-}
-
-static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
-{
-	u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
-	struct gro_list *gro_list = &napi->gro_hash[bucket];
-	struct list_head *head = &offload_base;
-	struct packet_offload *ptype;
-	__be16 type = skb->protocol;
-	struct sk_buff *pp = NULL;
-	enum gro_result ret;
-	int same_flow;
-	int grow;
-
-	if (netif_elide_gro(skb->dev))
-		goto normal;
-
-	gro_list_prepare(&gro_list->list, skb);
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(ptype, head, list) {
-		if (ptype->type != type || !ptype->callbacks.gro_receive)
-			continue;
-
-		skb_set_network_header(skb, skb_gro_offset(skb));
-		skb_reset_mac_len(skb);
-		NAPI_GRO_CB(skb)->same_flow = 0;
-		NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
-		NAPI_GRO_CB(skb)->free = 0;
-		NAPI_GRO_CB(skb)->encap_mark = 0;
-		NAPI_GRO_CB(skb)->recursion_counter = 0;
-		NAPI_GRO_CB(skb)->is_fou = 0;
-		NAPI_GRO_CB(skb)->is_atomic = 1;
-		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
-
-		/* Setup for GRO checksum validation */
-		switch (skb->ip_summed) {
-		case CHECKSUM_COMPLETE:
-			NAPI_GRO_CB(skb)->csum = skb->csum;
-			NAPI_GRO_CB(skb)->csum_valid = 1;
-			NAPI_GRO_CB(skb)->csum_cnt = 0;
-			break;
-		case CHECKSUM_UNNECESSARY:
-			NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
-			NAPI_GRO_CB(skb)->csum_valid = 0;
-			break;
-		default:
-			NAPI_GRO_CB(skb)->csum_cnt = 0;
-			NAPI_GRO_CB(skb)->csum_valid = 0;
-		}
-
-		pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
-					ipv6_gro_receive, inet_gro_receive,
-					&gro_list->list, skb);
-		break;
-	}
-	rcu_read_unlock();
-
-	if (&ptype->list == head)
-		goto normal;
-
-	if (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;
-
-	if (pp) {
-		skb_list_del_init(pp);
-		napi_gro_complete(napi, pp);
-		gro_list->count--;
-	}
-
-	if (same_flow)
-		goto ok;
-
-	if (NAPI_GRO_CB(skb)->flush)
-		goto normal;
-
-	if (unlikely(gro_list->count >= MAX_GRO_SKBS))
-		gro_flush_oldest(napi, &gro_list->list);
-	else
-		gro_list->count++;
-
-	NAPI_GRO_CB(skb)->count = 1;
-	NAPI_GRO_CB(skb)->age = jiffies;
-	NAPI_GRO_CB(skb)->last = skb;
-	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
-	list_add(&skb->list, &gro_list->list);
-	ret = GRO_HELD;
-
-pull:
-	grow = skb_gro_offset(skb) - skb_headlen(skb);
-	if (grow > 0)
-		gro_pull_from_frag0(skb, grow);
-ok:
-	if (gro_list->count) {
-		if (!test_bit(bucket, &napi->gro_bitmask))
-			__set_bit(bucket, &napi->gro_bitmask);
-	} else if (test_bit(bucket, &napi->gro_bitmask)) {
-		__clear_bit(bucket, &napi->gro_bitmask);
-	}
-
-	return ret;
-
-normal:
-	ret = GRO_NORMAL;
-	goto pull;
-}
-
-struct packet_offload *gro_find_receive_by_type(__be16 type)
-{
-	struct list_head *offload_head = &offload_base;
-	struct packet_offload *ptype;
-
-	list_for_each_entry_rcu(ptype, offload_head, list) {
-		if (ptype->type != type || !ptype->callbacks.gro_receive)
-			continue;
-		return ptype;
-	}
-	return NULL;
-}
-EXPORT_SYMBOL(gro_find_receive_by_type);
-
-struct packet_offload *gro_find_complete_by_type(__be16 type)
-{
-	struct list_head *offload_head = &offload_base;
-	struct packet_offload *ptype;
-
-	list_for_each_entry_rcu(ptype, offload_head, list) {
-		if (ptype->type != type || !ptype->callbacks.gro_complete)
-			continue;
-		return ptype;
-	}
-	return NULL;
-}
-EXPORT_SYMBOL(gro_find_complete_by_type);
-
-static gro_result_t napi_skb_finish(struct napi_struct *napi,
-				    struct sk_buff *skb,
-				    gro_result_t ret)
-{
-	switch (ret) {
-	case GRO_NORMAL:
-		gro_normal_one(napi, skb, 1);
-		break;
-
-	case GRO_MERGED_FREE:
-		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
-			napi_skb_free_stolen_head(skb);
-		else if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
-			__kfree_skb(skb);
-		else
-			__kfree_skb_defer(skb);
-		break;
-
-	case GRO_HELD:
-	case GRO_MERGED:
-	case GRO_CONSUMED:
-		break;
-	}
-
-	return ret;
-}
-
-gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
-{
-	gro_result_t ret;
-
-	skb_mark_napi_id(skb, napi);
-	trace_napi_gro_receive_entry(skb);
-
-	skb_gro_reset_offset(skb, 0);
-
-	ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
-	trace_napi_gro_receive_exit(ret);
-
-	return ret;
-}
-EXPORT_SYMBOL(napi_gro_receive);
-
-static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
-{
-	if (unlikely(skb->pfmemalloc)) {
-		consume_skb(skb);
-		return;
-	}
-	__skb_pull(skb, skb_headlen(skb));
-	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
-	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
-	__vlan_hwaccel_clear_tag(skb);
-	skb->dev = napi->dev;
-	skb->skb_iif = 0;
-
-	/* eth_type_trans() assumes pkt_type is PACKET_HOST */
-	skb->pkt_type = PACKET_HOST;
-
-	skb->encapsulation = 0;
-	skb_shinfo(skb)->gso_type = 0;
-	skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
-	if (unlikely(skb->slow_gro)) {
-		skb_orphan(skb);
-		skb_ext_reset(skb);
-		nf_reset_ct(skb);
-		skb->slow_gro = 0;
-	}
-
-	napi->skb = skb;
-}
-
-struct sk_buff *napi_get_frags(struct napi_struct *napi)
-{
-	struct sk_buff *skb = napi->skb;
-
-	if (!skb) {
-		skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
-		if (skb) {
-			napi->skb = skb;
-			skb_mark_napi_id(skb, napi);
-		}
-	}
-	return skb;
-}
-EXPORT_SYMBOL(napi_get_frags);
-
-static gro_result_t napi_frags_finish(struct napi_struct *napi,
-				      struct sk_buff *skb,
-				      gro_result_t ret)
-{
-	switch (ret) {
-	case GRO_NORMAL:
-	case GRO_HELD:
-		__skb_push(skb, ETH_HLEN);
-		skb->protocol = eth_type_trans(skb, skb->dev);
-		if (ret == GRO_NORMAL)
-			gro_normal_one(napi, skb, 1);
-		break;
-
-	case GRO_MERGED_FREE:
-		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
-			napi_skb_free_stolen_head(skb);
-		else
-			napi_reuse_skb(napi, skb);
-		break;
-
-	case GRO_MERGED:
-	case GRO_CONSUMED:
-		break;
-	}
-
-	return ret;
-}
-
-/* Upper GRO stack assumes network header starts at gro_offset=0
- * Drivers could call both napi_gro_frags() and napi_gro_receive()
- * We copy ethernet header into skb->data to have a common layout.
- */
-static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
-{
-	struct sk_buff *skb = napi->skb;
-	const struct ethhdr *eth;
-	unsigned int hlen = sizeof(*eth);
-
-	napi->skb = NULL;
-
-	skb_reset_mac_header(skb);
-	skb_gro_reset_offset(skb, hlen);
-
-	if (unlikely(skb_gro_header_hard(skb, hlen))) {
-		eth = skb_gro_header_slow(skb, hlen, 0);
-		if (unlikely(!eth)) {
-			net_warn_ratelimited("%s: dropping impossible skb from %s\n",
-					     __func__, napi->dev->name);
-			napi_reuse_skb(napi, skb);
-			return NULL;
-		}
-	} else {
-		eth = (const struct ethhdr *)skb->data;
-		gro_pull_from_frag0(skb, hlen);
-		NAPI_GRO_CB(skb)->frag0 += hlen;
-		NAPI_GRO_CB(skb)->frag0_len -= hlen;
-	}
-	__skb_pull(skb, hlen);
-
-	/*
-	 * This works because the only protocols we care about don't require
-	 * special handling.
-	 * We'll fix it up properly in napi_frags_finish()
-	 */
-	skb->protocol = eth->h_proto;
-
-	return skb;
-}
-
-gro_result_t napi_gro_frags(struct napi_struct *napi)
-{
-	gro_result_t ret;
-	struct sk_buff *skb = napi_frags_skb(napi);
-
-	trace_napi_gro_frags_entry(skb);
-
-	ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
-	trace_napi_gro_frags_exit(ret);
-
-	return ret;
-}
-EXPORT_SYMBOL(napi_gro_frags);
-
-/* Compute the checksum from gro_offset and return the folded value
- * after adding in any pseudo checksum.
- */
-__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
-{
-	__wsum wsum;
-	__sum16 sum;
-
-	wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
-
-	/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
-	sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
-	/* See comments in __skb_checksum_complete(). */
-	if (likely(!sum)) {
-		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
-		    !skb->csum_complete_sw)
-			netdev_rx_csum_fault(skb->dev, skb);
-	}
-
-	NAPI_GRO_CB(skb)->csum = wsum;
-	NAPI_GRO_CB(skb)->csum_valid = 1;
-
-	return sum;
-}
-EXPORT_SYMBOL(__skb_gro_checksum_complete);
 
 static void net_rps_send_ipi(struct softnet_data *remsd)
 {
···
 	INIT_LIST_HEAD(&ptype_all);
 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
 		INIT_LIST_HEAD(&ptype_base[i]);
-
-	INIT_LIST_HEAD(&offload_base);
 
 	if (register_pernet_subsys(&netdev_net_ops))
 		goto out;

net/core/gro.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <net/gro.h>
+#include <net/dst_metadata.h>
+#include <net/busy_poll.h>
+#include <trace/events/net.h>
+
+#define MAX_GRO_SKBS 8
+
+/* This should be increased if a protocol with a bigger head is added. */
+#define GRO_MAX_HEAD (MAX_HEADER + 128)
+
+static DEFINE_SPINLOCK(offload_lock);
+static struct list_head offload_base __read_mostly = LIST_HEAD_INIT(offload_base);
+/* Maximum number of GRO_NORMAL skbs to batch up for list-RX */
+int gro_normal_batch __read_mostly = 8;
+
+/**
+ *	dev_add_offload - register offload handlers
+ *	@po: protocol offload declaration
+ *
+ *	Add protocol offload handlers to the networking stack. The passed
+ *	&proto_offload is linked into kernel lists and may not be freed until
+ *	it has been removed from the kernel lists.
+ *
+ *	This call does not sleep therefore it can not
+ *	guarantee all CPU's that are in middle of receiving packets
+ *	will see the new offload handlers (until the next received packet).
+ */
+void dev_add_offload(struct packet_offload *po)
+{
+	struct packet_offload *elem;
+
+	spin_lock(&offload_lock);
+	list_for_each_entry(elem, &offload_base, list) {
+		if (po->priority < elem->priority)
+			break;
+	}
+	list_add_rcu(&po->list, elem->list.prev);
+	spin_unlock(&offload_lock);
+}
+EXPORT_SYMBOL(dev_add_offload);
+
+/**
+ *	__dev_remove_offload	 - remove offload handler
+ *	@po: packet offload declaration
+ *
+ *	Remove a protocol offload handler that was previously added to the
+ *	kernel offload handlers by dev_add_offload(). The passed &offload_type
+ *	is removed from the kernel lists and can be freed or reused once this
+ *	function returns.
+ *
+ *      The packet type might still be in use by receivers
+ *	and must not be freed until after all the CPU's have gone
+ *	through a quiescent state.
+ */
+static void __dev_remove_offload(struct packet_offload *po)
+{
+	struct list_head *head = &offload_base;
+	struct packet_offload *po1;
+
+	spin_lock(&offload_lock);
+
+	list_for_each_entry(po1, head, list) {
+		if (po == po1) {
+			list_del_rcu(&po->list);
+			goto out;
+		}
+	}
+
+	pr_warn("dev_remove_offload: %p not found\n", po);
+out:
+	spin_unlock(&offload_lock);
+}
+
+/**
+ *	dev_remove_offload	 - remove packet offload handler
+ *	@po: packet offload declaration
+ *
+ *	Remove a packet offload handler that was previously added to the kernel
+ *	offload handlers by dev_add_offload(). The passed &offload_type is
+ *	removed from the kernel lists and can be freed or reused once this
+ *	function returns.
+ *
+ *	This call sleeps to guarantee that no CPU is looking at the packet
+ *	type after return.
+ */
+void dev_remove_offload(struct packet_offload *po)
+{
+	__dev_remove_offload(po);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(dev_remove_offload);
+
+/**
+ *	skb_mac_gso_segment - mac layer segmentation handler.
+ *	@skb: buffer to segment
+ *	@features: features for the output path (see dev->features)
+ */
+struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
+				    netdev_features_t features)
+{
+	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
+	struct packet_offload *ptype;
+	int vlan_depth = skb->mac_len;
+	__be16 type = skb_network_protocol(skb, &vlan_depth);
+
+	if (unlikely(!type))
+		return ERR_PTR(-EINVAL);
+
+	__skb_pull(skb, vlan_depth);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, &offload_base, list) {
+		if (ptype->type == type && ptype->callbacks.gso_segment) {
+			segs = ptype->callbacks.gso_segment(skb, features);
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	__skb_push(skb, skb->data - skb_mac_header(skb));
+
+	return segs;
+}
+EXPORT_SYMBOL(skb_mac_gso_segment);
+
+int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
+{
+	struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb);
+	unsigned int offset = skb_gro_offset(skb);
+	unsigned int headlen = skb_headlen(skb);
+	unsigned int len = skb_gro_len(skb);
+	unsigned int delta_truesize;
+	unsigned int new_truesize;
+	struct sk_buff *lp;
+
+	if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush))
+		return -E2BIG;
+
+	lp = NAPI_GRO_CB(p)->last;
+	pinfo = skb_shinfo(lp);
+
+	if (headlen <= offset) {
+		skb_frag_t *frag;
+		skb_frag_t *frag2;
+		int i = skbinfo->nr_frags;
+		int nr_frags = pinfo->nr_frags + i;
+
+		if (nr_frags > MAX_SKB_FRAGS)
+			goto merge;
+
+		offset -= headlen;
+		pinfo->nr_frags = nr_frags;
+		skbinfo->nr_frags = 0;
+
+		frag = pinfo->frags + nr_frags;
+		frag2 = skbinfo->frags + i;
+		do {
+			*--frag = *--frag2;
+		} while (--i);
+
+		skb_frag_off_add(frag, offset);
+		skb_frag_size_sub(frag, offset);
+
+		/* all fragments truesize : remove (head size + sk_buff) */
+		new_truesize = SKB_TRUESIZE(skb_end_offset(skb));
+		delta_truesize = skb->truesize - new_truesize;
+
+		skb->truesize = new_truesize;
+		skb->len -= skb->data_len;
+		skb->data_len = 0;
+
+		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
+		goto done;
+	} else if (skb->head_frag) {
+		int nr_frags = pinfo->nr_frags;
+		skb_frag_t *frag = pinfo->frags + nr_frags;
+		struct page *page = virt_to_head_page(skb->head);
+		unsigned int first_size = headlen - offset;
+		unsigned int first_offset;
+
+		if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
+			goto merge;
+
+		first_offset = skb->data -
+			       (unsigned char *)page_address(page) +
+			       offset;
+
+		pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
+
+		__skb_frag_set_page(frag, page);
+		skb_frag_off_set(frag, first_offset);
+		skb_frag_size_set(frag, first_size);
+
+		memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
+		/* We dont need to clear skbinfo->nr_frags here */
+
+		new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
+		delta_truesize = skb->truesize - new_truesize;
+		skb->truesize = new_truesize;
+		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
+		goto done;
+	}
+
+merge:
+	/* sk owenrship - if any - completely transferred to the aggregated packet */
+	skb->destructor = NULL;
+	delta_truesize = skb->truesize;
+	if (offset > headlen) {
+		unsigned int eat = offset - headlen;
+
+		skb_frag_off_add(&skbinfo->frags[0], eat);
+		skb_frag_size_sub(&skbinfo->frags[0], eat);
+		skb->data_len -= eat;
+		skb->len -= eat;
+		offset = headlen;
+	}
+
+	__skb_pull(skb, offset);
+
+	if (NAPI_GRO_CB(p)->last == p)
+		skb_shinfo(p)->frag_list = skb;
+	else
+		NAPI_GRO_CB(p)->last->next = skb;
+	NAPI_GRO_CB(p)->last = skb;
+	__skb_header_release(skb);
+	lp = p;
+
+done:
+	NAPI_GRO_CB(p)->count++;
+	p->data_len += len;
+	p->truesize += delta_truesize;
+	p->len += len;
+	if (lp != p) {
+		lp->data_len += len;
+		lp->truesize += delta_truesize;
+		lp->len += len;
+	}
+	NAPI_GRO_CB(skb)->same_flow = 1;
+	return 0;
+}
+
+
+static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
+{
+	struct packet_offload *ptype;
+	__be16 type = skb->protocol;
+	struct list_head *head = &offload_base;
+	int err = -ENOENT;
+
+	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
+
+	if (NAPI_GRO_CB(skb)->count == 1) {
+		skb_shinfo(skb)->gso_size = 0;
+		goto out;
+	}
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_complete)
+			continue;
+
+		err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
+					 ipv6_gro_complete, inet_gro_complete,
+					 skb, 0);
+		break;
+	}
+	rcu_read_unlock();
+
+	if (err) {
+		WARN_ON(&ptype->list == head);
+		kfree_skb(skb);
+		return;
+	}
+
+out:
+	gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count);
+}
+
+static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
+				   bool flush_old)
+{
+	struct list_head *head = &napi->gro_hash[index].list;
+	struct sk_buff *skb, *p;
+
+	list_for_each_entry_safe_reverse(skb, p, head, list) {
+		if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
+			return;
+		skb_list_del_init(skb);
+		napi_gro_complete(napi, skb);
+		napi->gro_hash[index].count--;
+	}
+
+	if (!napi->gro_hash[index].count)
+		__clear_bit(index, &napi->gro_bitmask);
+}
+
+/* napi->gro_hash[].list contains packets ordered by age.
+ * youngest packets at the head of it.
+ * Complete skbs in reverse order to reduce latencies.
+ */
+void napi_gro_flush(struct napi_struct *napi, bool flush_old)
+{
+	unsigned long bitmask = napi->gro_bitmask;
+	unsigned int i, base = ~0U;
+
+	while ((i = ffs(bitmask)) != 0) {
+		bitmask >>= i;
+		base += i;
+		__napi_gro_flush_chain(napi, base, flush_old);
+	}
+}
+EXPORT_SYMBOL(napi_gro_flush);
+
+static void gro_list_prepare(const struct list_head *head,
+			     const struct sk_buff *skb)
+{
+	unsigned int maclen = skb->dev->hard_header_len;
+	u32 hash = skb_get_hash_raw(skb);
+	struct sk_buff *p;
+
+	list_for_each_entry(p, head, list) {
+		unsigned long diffs;
+
+		NAPI_GRO_CB(p)->flush = 0;
+
+		if (hash != skb_get_hash_raw(p)) {
+			NAPI_GRO_CB(p)->same_flow = 0;
+			continue;
+		}
+
+		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
+		diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
+		if (skb_vlan_tag_present(p))
+			diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb);
+		diffs |= skb_metadata_differs(p, skb);
+		if (maclen == ETH_HLEN)
+			diffs |= compare_ether_header(skb_mac_header(p),
+						      skb_mac_header(skb));
+		else if (!diffs)
+			diffs = memcmp(skb_mac_header(p),
+				       skb_mac_header(skb),
+				       maclen);
+
+		/* in most common scenarions 'slow_gro' is 0
+		 * otherwise we are already on some slower paths
+		 * either skip all the infrequent tests altogether or
+		 * avoid trying too hard to skip each of them individually
+		 */
+		if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) {
+#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+			struct tc_skb_ext *skb_ext;
+			struct tc_skb_ext *p_ext;
+#endif
+
+			diffs |= p->sk != skb->sk;
+			diffs |= skb_metadata_dst_cmp(p, skb);
+			diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
+
+#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+			skb_ext = skb_ext_find(skb, TC_SKB_EXT);
+			p_ext = skb_ext_find(p, TC_SKB_EXT);
+
+			diffs |= (!!p_ext) ^ (!!skb_ext);
+			if (!diffs && unlikely(skb_ext))
+				diffs |= p_ext->chain ^ skb_ext->chain;
+#endif
+		}
+
+		NAPI_GRO_CB(p)->same_flow = !diffs;
+	}
+}
+
+static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
+{
+	const struct skb_shared_info *pinfo = skb_shinfo(skb);
+	const skb_frag_t *frag0 = &pinfo->frags[0];
+
+	NAPI_GRO_CB(skb)->data_offset = 0;
+	NAPI_GRO_CB(skb)->frag0 = NULL;
+	NAPI_GRO_CB(skb)->frag0_len = 0;
+
+	if (!skb_headlen(skb) && pinfo->nr_frags &&
+	    !PageHighMem(skb_frag_page(frag0)) &&
+	    (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
+		NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
+		NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
+						    skb_frag_size(frag0),
+						    skb->end - skb->tail);
+	}
+}
+
+static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
+{
+	struct skb_shared_info *pinfo = skb_shinfo(skb);
+
+	BUG_ON(skb->end - skb->tail < grow);
+
+	memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
+
+	skb->data_len -= grow;
+	skb->tail += grow;
+
+	skb_frag_off_add(&pinfo->frags[0], grow);
+	skb_frag_size_sub(&pinfo->frags[0], grow);
+
+	if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
+		skb_frag_unref(skb, 0);
+		memmove(pinfo->frags, pinfo->frags + 1,
+			--pinfo->nr_frags * sizeof(pinfo->frags[0]));
+	}
+}
+
+static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head)
+{
+	struct sk_buff *oldest;
+
+	oldest = list_last_entry(head, struct sk_buff, list);
+
+	/* We are called with head length >= MAX_GRO_SKBS, so this is
+	 * impossible.
+	 */
+	if (WARN_ON_ONCE(!oldest))
+		return;
+
+	/* Do not adjust napi->gro_hash[].count, caller is adding a new
+	 * SKB to the chain.
+	 */
+	skb_list_del_init(oldest);
+	napi_gro_complete(napi, oldest);
+}
+
+static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
+{
+	u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
+	struct gro_list *gro_list = &napi->gro_hash[bucket];
+	struct list_head *head = &offload_base;
+	struct packet_offload *ptype;
+	__be16 type = skb->protocol;
+	struct sk_buff *pp = NULL;
+	enum gro_result ret;
+	int same_flow;
+	int grow;
+
+	if (netif_elide_gro(skb->dev))
+		goto normal;
+
+	gro_list_prepare(&gro_list->list, skb);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_receive)
+			continue;
+
+		skb_set_network_header(skb, skb_gro_offset(skb));
+		skb_reset_mac_len(skb);
+		NAPI_GRO_CB(skb)->same_flow = 0;
+		NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
+		NAPI_GRO_CB(skb)->free = 0;
+		NAPI_GRO_CB(skb)->encap_mark = 0;
+		NAPI_GRO_CB(skb)->recursion_counter = 0;
+		NAPI_GRO_CB(skb)->is_fou = 0;
+		NAPI_GRO_CB(skb)->is_atomic = 1;
+		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
+
+		/* Setup for GRO checksum validation */
+		switch (skb->ip_summed) {
+		case CHECKSUM_COMPLETE:
+			NAPI_GRO_CB(skb)->csum = skb->csum;
+			NAPI_GRO_CB(skb)->csum_valid = 1;
+			NAPI_GRO_CB(skb)->csum_cnt = 0;
+			break;
+		case CHECKSUM_UNNECESSARY:
+			NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
+			NAPI_GRO_CB(skb)->csum_valid = 0;
+			break;
+		default:
+			NAPI_GRO_CB(skb)->csum_cnt = 0;
+			NAPI_GRO_CB(skb)->csum_valid = 0;
+		}
+
+		pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
+					ipv6_gro_receive, inet_gro_receive,
+					&gro_list->list, skb);
+		break;
+	}
+	rcu_read_unlock();
+
+	if (&ptype->list == head)
+		goto normal;
+
+	if (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;
+
+	if (pp) {
+		skb_list_del_init(pp);
+		napi_gro_complete(napi, pp);
+		gro_list->count--;
+	}
+
+	if (same_flow)
+		goto ok;
+
+	if (NAPI_GRO_CB(skb)->flush)
+		goto normal;
+
+	if (unlikely(gro_list->count >= MAX_GRO_SKBS))
+		gro_flush_oldest(napi, &gro_list->list);
+	else
+		gro_list->count++;
+
+	NAPI_GRO_CB(skb)->count = 1;
+	NAPI_GRO_CB(skb)->age = jiffies;
+	NAPI_GRO_CB(skb)->last = skb;
+	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
+	list_add(&skb->list, &gro_list->list);
+	ret = GRO_HELD;
+
+pull:
+	grow = skb_gro_offset(skb) - skb_headlen(skb);
+	if (grow > 0)
+		gro_pull_from_frag0(skb, grow);
+ok:
+	if (gro_list->count) {
+		if (!test_bit(bucket, &napi->gro_bitmask))
+			__set_bit(bucket, &napi->gro_bitmask);
+	} else if (test_bit(bucket, &napi->gro_bitmask)) {
+		__clear_bit(bucket, &napi->gro_bitmask);
+	}
+
+	return ret;
+
+normal:
+	ret = GRO_NORMAL;
+	goto pull;
+}
+
+struct packet_offload *gro_find_receive_by_type(__be16 type)
+{
+	struct list_head *offload_head = &offload_base;
+	struct packet_offload *ptype;
+
+	list_for_each_entry_rcu(ptype, offload_head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_receive)
+			continue;
+		return ptype;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(gro_find_receive_by_type);
+
+struct packet_offload *gro_find_complete_by_type(__be16 type)
+{
+	struct list_head *offload_head = &offload_base;
+	struct packet_offload *ptype;
+
+	list_for_each_entry_rcu(ptype, offload_head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_complete)
+			continue;
+		return ptype;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(gro_find_complete_by_type);
+
+static gro_result_t napi_skb_finish(struct napi_struct *napi,
+				    struct sk_buff *skb,
+				    gro_result_t ret)
+{
+	switch (ret) {
+	case GRO_NORMAL:
+		gro_normal_one(napi, skb, 1);
+		break;
+
+	case GRO_MERGED_FREE:
+		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
+			napi_skb_free_stolen_head(skb);
+		else if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
+			__kfree_skb(skb);
+		else
+			__kfree_skb_defer(skb);
+		break;
+
+	case GRO_HELD:
+	case GRO_MERGED:
+	case GRO_CONSUMED:
+		break;
+	}
+
+	return ret;
+}
+
+gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
+{
+	gro_result_t ret;
+
+	skb_mark_napi_id(skb, napi);
+	trace_napi_gro_receive_entry(skb);
+
+	skb_gro_reset_offset(skb, 0);
+
+	ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
+	trace_napi_gro_receive_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(napi_gro_receive);
+
+static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
+{
+	if (unlikely(skb->pfmemalloc)) {
+		consume_skb(skb);
+		return;
+	}
+	__skb_pull(skb, skb_headlen(skb));
+	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
+	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
+	__vlan_hwaccel_clear_tag(skb);
+	skb->dev = napi->dev;
+	skb->skb_iif = 0;
+
+	/* eth_type_trans() assumes pkt_type is PACKET_HOST */
+	skb->pkt_type = PACKET_HOST;
+
+	skb->encapsulation = 0;
+	skb_shinfo(skb)->gso_type = 0;
+	skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
+	if (unlikely(skb->slow_gro)) {
+		skb_orphan(skb);
+		skb_ext_reset(skb);
+		nf_reset_ct(skb);
+		skb->slow_gro = 0;
+	}
+
+	napi->skb = skb;
+}
+
+struct sk_buff *napi_get_frags(struct napi_struct *napi)
+{
+	struct sk_buff *skb = napi->skb;
+
+	if (!skb) {
+		skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
+		if (skb) {
+			napi->skb = skb;
+			skb_mark_napi_id(skb, napi);
+		}
+	}
+	return skb;
+}
+EXPORT_SYMBOL(napi_get_frags);
+
+static gro_result_t napi_frags_finish(struct napi_struct *napi,
+				      struct sk_buff *skb,
+				      gro_result_t ret)
+{
+	switch (ret) {
+	case GRO_NORMAL:
+	case GRO_HELD:
+		__skb_push(skb, ETH_HLEN);
+		skb->protocol = eth_type_trans(skb, skb->dev);
+		if (ret == GRO_NORMAL)
+			gro_normal_one(napi, skb, 1);
+		break;
+
+	case GRO_MERGED_FREE:
+		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
+			napi_skb_free_stolen_head(skb);
+		else
+			napi_reuse_skb(napi, skb);
+		break;
+
+	case GRO_MERGED:
+	case GRO_CONSUMED:
+		break;
+	}
+
+	return ret;
+}
+
+/* Upper GRO stack assumes network header starts at gro_offset=0
+ * Drivers could call both napi_gro_frags() and napi_gro_receive()
+ * We copy ethernet header into skb->data to have a common layout.
+ */
+static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
+{
+	struct sk_buff *skb = napi->skb;
+	const struct ethhdr *eth;
+	unsigned int hlen = sizeof(*eth);
+
+	napi->skb = NULL;
+
+	skb_reset_mac_header(skb);
+	skb_gro_reset_offset(skb, hlen);
+
+	if (unlikely(skb_gro_header_hard(skb, hlen))) {
+		eth = skb_gro_header_slow(skb, hlen, 0);
+		if (unlikely(!eth)) {
+			net_warn_ratelimited("%s: dropping impossible skb from %s\n",
+					     __func__, napi->dev->name);
+			napi_reuse_skb(napi, skb);
+			return NULL;
+		}
+	} else {
+		eth = (const struct ethhdr *)skb->data;
+		gro_pull_from_frag0(skb, hlen);
+		NAPI_GRO_CB(skb)->frag0 += hlen;
+		NAPI_GRO_CB(skb)->frag0_len -= hlen;
+	}
+	__skb_pull(skb, hlen);
+
+	/*
+	 * This works because the only protocols we care about don't require
+	 * special handling.
+	 * We'll fix it up properly in napi_frags_finish()
+	 */
+	skb->protocol = eth->h_proto;
+
+	return skb;
+}
+
+gro_result_t napi_gro_frags(struct napi_struct *napi)
+{
+	gro_result_t ret;
+	struct sk_buff *skb = napi_frags_skb(napi);
+
+	trace_napi_gro_frags_entry(skb);
+
+	ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
+	trace_napi_gro_frags_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(napi_gro_frags);
+
+/* Compute the checksum from gro_offset and return the folded value
+ * after adding in any pseudo checksum.
+ */
+__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
+{
+	__wsum wsum;
+	__sum16 sum;
+
+	wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
+
+	/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
+	sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
+	/* See comments in __skb_checksum_complete(). */
+	if (likely(!sum)) {
+		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    !skb->csum_complete_sw)
+			netdev_rx_csum_fault(skb->dev, skb);
+	}
+
+	NAPI_GRO_CB(skb)->csum = wsum;
+	NAPI_GRO_CB(skb)->csum_valid = 1;
+
+	return sum;
+}
+EXPORT_SYMBOL(__skb_gro_checksum_complete);

net/core/skbuff.c

···
 }
 EXPORT_SYMBOL_GPL(skb_segment_list);
 
-int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
-{
-	if (unlikely(p->len + skb->len >= 65536))
-		return -E2BIG;
-
-	if (NAPI_GRO_CB(p)->last == p)
-		skb_shinfo(p)->frag_list = skb;
-	else
-		NAPI_GRO_CB(p)->last->next = skb;
-
-	skb_pull(skb, skb_gro_offset(skb));
-
-	NAPI_GRO_CB(p)->last = skb;
-	NAPI_GRO_CB(p)->count++;
-	p->data_len += skb->len;
-
-	/* sk owenrship - if any - completely transferred to the aggregated packet */
-	skb->destructor = NULL;
-	p->truesize += skb->truesize;
-	p->len += skb->len;
-
-	NAPI_GRO_CB(skb)->same_flow = 1;
-
-	return 0;
-}
-
 /**
  *	skb_segment - Perform protocol segmentation on skb.
  *	@head_skb: buffer to segment
···
 	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(skb_segment);
-
-int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
-{
-	struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb);
-	unsigned int offset = skb_gro_offset(skb);
-	unsigned int headlen = skb_headlen(skb);
-	unsigned int len = skb_gro_len(skb);
-	unsigned int delta_truesize;
-	unsigned int new_truesize;
-	struct sk_buff *lp;
-
-	if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush))
-		return -E2BIG;
-
-	lp = NAPI_GRO_CB(p)->last;
-	pinfo = skb_shinfo(lp);
-
-	if (headlen <= offset) {
-		skb_frag_t *frag;
-		skb_frag_t *frag2;
-		int i = skbinfo->nr_frags;
-		int nr_frags = pinfo->nr_frags + i;
-
-		if (nr_frags > MAX_SKB_FRAGS)
-			goto merge;
-
-		offset -= headlen;
-		pinfo->nr_frags = nr_frags;
-		skbinfo->nr_frags = 0;
-
-		frag = pinfo->frags + nr_frags;
-		frag2 = skbinfo->frags + i;
-		do {
-			*--frag = *--frag2;
-		} while (--i);
-
-		skb_frag_off_add(frag, offset);
-		skb_frag_size_sub(frag, offset);
-
-		/* all fragments truesize : remove (head size + sk_buff) */
-		new_truesize = SKB_TRUESIZE(skb_end_offset(skb));
-		delta_truesize = skb->truesize - new_truesize;
-
-		skb->truesize = new_truesize;
-		skb->len -= skb->data_len;
-		skb->data_len = 0;
-
-		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
-		goto done;
-	} else if (skb->head_frag) {
-		int nr_frags = pinfo->nr_frags;
-		skb_frag_t *frag = pinfo->frags + nr_frags;
-		struct page *page = virt_to_head_page(skb->head);
-		unsigned int first_size = headlen - offset;
-		unsigned int first_offset;
-
-		if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
-			goto merge;
-
-		first_offset = skb->data -
-			       (unsigned char *)page_address(page) +
-			       offset;
-
-		pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
-
-		__skb_frag_set_page(frag, page);
-		skb_frag_off_set(frag, first_offset);
-		skb_frag_size_set(frag, first_size);
-
-		memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
-		/* We dont need to clear skbinfo->nr_frags here */
-
-		new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
-		delta_truesize = skb->truesize - new_truesize;
-		skb->truesize = new_truesize;
-		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
-		goto done;
-	}
-
-merge:
-	/* sk owenrship - if any - completely transferred to the aggregated packet */
-	skb->destructor = NULL;
-	delta_truesize = skb->truesize;
-	if (offset > headlen) {
-		unsigned int eat = offset - headlen;
-
-		skb_frag_off_add(&skbinfo->frags[0], eat);
-		skb_frag_size_sub(&skbinfo->frags[0], eat);
-		skb->data_len -= eat;
-		skb->len -= eat;
-		offset = headlen;
-	}
-
-	__skb_pull(skb, offset);
-
-	if (NAPI_GRO_CB(p)->last == p)
-		skb_shinfo(p)->frag_list = skb;
-	else
-		NAPI_GRO_CB(p)->last->next = skb;
-	NAPI_GRO_CB(p)->last = skb;
-	__skb_header_release(skb);
-	lp = p;
-
-done:
-	NAPI_GRO_CB(p)->count++;
-	p->data_len += len;
-	p->truesize += delta_truesize;
-	p->len += len;
-	if (lp != p) {
-		lp->data_len += len;
-		lp->truesize += delta_truesize;
-		lp->len += len;
-	}
-	NAPI_GRO_CB(skb)->same_flow = 1;
-	return 0;
-}
 
 #ifdef CONFIG_SKB_EXTENSIONS
 #define SKB_EXT_ALIGN_VALUE	8

net/ipv4/af_inet.c

···
 #include <net/route.h>
 #include <net/ip_fib.h>
 #include <net/inet_connection_sock.h>
+#include <net/gro.h>
 #include <net/tcp.h>
 #include <net/udp.h>
 #include <net/udplite.h>

net/ipv4/esp4_offload.c

···
 #include <crypto/authenc.h>
 #include <linux/err.h>
 #include <linux/module.h>
+#include <net/gro.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
 #include <net/esp.h>

net/ipv4/fou.c

···
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <net/genetlink.h>
+#include <net/gro.h>
 #include <net/gue.h>
 #include <net/fou.h>
 #include <net/ip.h>

net/ipv4/gre_offload.c

···
 #include <linux/init.h>
 #include <net/protocol.h>
 #include <net/gre.h>
+#include <net/gro.h>
 
 static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
 				       netdev_features_t features)

net/ipv4/tcp_offload.c

···
 
 #include <linux/indirect_call_wrapper.h>
 #include <linux/skbuff.h>
+#include <net/gro.h>
 #include <net/tcp.h>
 #include <net/protocol.h>
 

net/ipv4/udp_offload.c

···
  */
 
 #include <linux/skbuff.h>
+#include <net/gro.h>
 #include <net/udp.h>
 #include <net/protocol.h>
 #include <net/inet_common.h>
···
 out:
 	return segs;
 }
+
+static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
+{
+	if (unlikely(p->len + skb->len >= 65536))
+		return -E2BIG;
+
+	if (NAPI_GRO_CB(p)->last == p)
+		skb_shinfo(p)->frag_list = skb;
+	else
+		NAPI_GRO_CB(p)->last->next = skb;
+
+	skb_pull(skb, skb_gro_offset(skb));
+
+	NAPI_GRO_CB(p)->last = skb;
+	NAPI_GRO_CB(p)->count++;
+	p->data_len += skb->len;
+
+	/* sk owenrship - if any - completely transferred to the aggregated packet */
+	skb->destructor = NULL;
+	p->truesize += skb->truesize;
+	p->len += skb->len;
+
+	NAPI_GRO_CB(skb)->same_flow = 1;
+
+	return 0;
+}
+
 
 #define UDP_GRO_CNT_MAX 64
 static struct sk_buff *udp_gro_receive_segment(struct list_head *head,

net/ipv6/esp6_offload.c

···
 #include <crypto/authenc.h>
 #include <linux/err.h>
 #include <linux/module.h>
+#include <net/gro.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
 #include <net/esp.h>

net/ipv6/tcpv6_offload.c

···
  */
 #include <linux/indirect_call_wrapper.h>
 #include <linux/skbuff.h>
+#include <net/gro.h>
 #include <net/protocol.h>
 #include <net/tcp.h>
 #include <net/ip6_checksum.h>

net/ipv6/udp_offload.c

···
 #include <net/udp.h>
 #include <net/ip6_checksum.h>
 #include "ip6_offload.h"
+#include <net/gro.h>
 
 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 					 netdev_features_t features)