1 files changed, 450 insertions, 0 deletions

diff --git a/include/net/gro.h b/include/net/gro.h
new file mode 100644
index 000000000..a4fab7062
--- /dev/null
+++ b/include/net/gro.h
@@ -0,0 +1,450 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _NET_IPV6_GRO_H
+#define _NET_IPV6_GRO_H
+
+#include <linux/indirect_call_wrapper.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/ip6_checksum.h>
+#include <linux/skbuff.h>
+#include <net/udp.h>
+
+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;
+
+	/* Used in ipv6_gro_receive() and foo-over-udp */
+	u16	proto;
+
+	/* jiffies when first packet was created/queued */
+	unsigned long age;
+
+/* Used in napi_gro_cb::free */
+#define NAPI_GRO_FREE             1
+#define NAPI_GRO_FREE_STOLEN_HEAD 2
+	/* portion of the cb set to zero at every gro iteration */
+	struct_group(zeroed,
+
+		/* Start offset for remote checksum offload */
+		u16	gro_remcsum_start;
+
+		/* 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;
+
+		/* 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_header(struct sk_buff *skb,
+					unsigned int hlen, unsigned int offset)
+{
+	void *ptr;
+
+	ptr = skb_gro_header_fast(skb, offset);
+	if (skb_gro_header_hard(skb, hlen))
+		ptr = skb_gro_header_slow(skb, hlen, offset);
+	return ptr;
+}
+
+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 = wsum_negate(csum_partial(start, len,
+						wsum_negate(NAPI_GRO_CB(skb)->csum)));
+}
+
+/* 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(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(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 *));
+INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
+							   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(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 >= READ_ONCE(gro_normal_batch))
+		gro_normal_list(napi);
+}
+
+
+#endif /* _NET_IPV6_GRO_H */