include/net/xdp_sock.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /* AF_XDP internal functions
  * Copyright(c) 2018 Intel Corporation.
  */

 #ifndef _LINUX_XDP_SOCK_H
 #define _LINUX_XDP_SOCK_H

 #include <linux/workqueue.h>
 #include <linux/if_xdp.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <net/sock.h>

 struct net_device;
 struct xsk_queue;

 /* Masks for xdp_umem_page flags.
  * The low 12-bits of the addr will be 0 since this is the page address, so we
  * can use them for flags.
  */
 #define XSK_NEXT_PG_CONTIG_SHIFT 0
 #define XSK_NEXT_PG_CONTIG_MASK (1ULL << XSK_NEXT_PG_CONTIG_SHIFT)

 struct xdp_umem_page {
 	void *addr;
 	dma_addr_t dma;
 };

 struct xdp_umem_fq_reuse {
 	u32 nentries;
 	u32 length;
 	u64 handles[];
 };

 /* Flags for the umem flags field.
  *
  * The NEED_WAKEUP flag is 1 due to the reuse of the flags field for public
  * flags. See inlude/uapi/include/linux/if_xdp.h.
  */
 #define XDP_UMEM_USES_NEED_WAKEUP (1 << 1)

 struct xdp_umem {
 	struct xsk_queue *fq;
 	struct xsk_queue *cq;
 	struct xdp_umem_page *pages;
 	u64 chunk_mask;
 	u64 size;
 	u32 headroom;
 	u32 chunk_size_nohr;
 	struct user_struct *user;
 	unsigned long address;
 	refcount_t users;
 	struct work_struct work;
 	struct page **pgs;
 	u32 npgs;
 	u16 queue_id;
 	u8 need_wakeup;
 	u8 flags;
 	int id;
 	struct net_device *dev;
 	struct xdp_umem_fq_reuse *fq_reuse;
 	bool zc;
 	spinlock_t xsk_list_lock;
 	struct list_head xsk_list;
 };

 /* Nodes are linked in the struct xdp_sock map_list field, and used to
  * track which maps a certain socket reside in.
  */

 struct xsk_map {
 	struct bpf_map map;
 	struct list_head __percpu *flush_list;
 	spinlock_t lock; /* Synchronize map updates */
 	struct xdp_sock *xsk_map[];
 };

 struct xsk_map_node {
 	struct list_head node;
 	struct xsk_map *map;
 	struct xdp_sock **map_entry;
 };

 struct xdp_sock {
 	/* struct sock must be the first member of struct xdp_sock */
 	struct sock sk;
 	struct xsk_queue *rx;
 	struct net_device *dev;
 	struct xdp_umem *umem;
 	struct list_head flush_node;
 	u16 queue_id;
 	bool zc;
 	enum {
 		XSK_READY = 0,
 		XSK_BOUND,
 		XSK_UNBOUND,
 	} state;
 	/* Protects multiple processes in the control path */
 	struct mutex mutex;
 	struct xsk_queue *tx ____cacheline_aligned_in_smp;
 	struct list_head list;
 	/* Mutual exclusion of NAPI TX thread and sendmsg error paths
 	 * in the SKB destructor callback.
 	 */
 	spinlock_t tx_completion_lock;
 	/* Protects generic receive. */
 	spinlock_t rx_lock;
 	u64 rx_dropped;
 	struct list_head map_list;
 	/* Protects map_list */
 	spinlock_t map_list_lock;
 };

 struct xdp_buff;
 #ifdef CONFIG_XDP_SOCKETS
 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
 /* Used from netdev driver */
 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
 u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
 void xsk_umem_discard_addr(struct xdp_umem *umem);
 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
 bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc);
 void xsk_umem_consume_tx_done(struct xdp_umem *umem);
 struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
 struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
 					  struct xdp_umem_fq_reuse *newq);
 void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq);
 struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev, u16 queue_id);
 void xsk_set_rx_need_wakeup(struct xdp_umem *umem);
 void xsk_set_tx_need_wakeup(struct xdp_umem *umem);
 void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);

 void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
 			     struct xdp_sock **map_entry);
 int xsk_map_inc(struct xsk_map *map);
 void xsk_map_put(struct xsk_map *map);
 int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,
 		       struct xdp_sock *xs);
 void __xsk_map_flush(struct bpf_map *map);

 static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
 						     u32 key)
 {
 	struct xsk_map *m = container_of(map, struct xsk_map, map);
 	struct xdp_sock *xs;

 	if (key >= map->max_entries)
 		return NULL;

 	xs = READ_ONCE(m->xsk_map[key]);
 	return xs;
 }

 static inline u64 xsk_umem_extract_addr(u64 addr)
 {
 	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
 }

 static inline u64 xsk_umem_extract_offset(u64 addr)
 {
 	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
 }

 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
 {
 	return xsk_umem_extract_addr(addr) + xsk_umem_extract_offset(addr);
 }

 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
 {
 	unsigned long page_addr;

 	addr = xsk_umem_add_offset_to_addr(addr);
 	page_addr = (unsigned long)umem->pages[addr >> PAGE_SHIFT].addr;

 	return (char *)(page_addr & PAGE_MASK) + (addr & ~PAGE_MASK);
 }

 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
 {
 	addr = xsk_umem_add_offset_to_addr(addr);

 	return umem->pages[addr >> PAGE_SHIFT].dma + (addr & ~PAGE_MASK);
 }

 /* Reuse-queue aware version of FILL queue helpers */
 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
 {
 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

 	if (rq->length >= cnt)
 		return true;

 	return xsk_umem_has_addrs(umem, cnt - rq->length);
 }

 static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
 {
 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

 	if (!rq->length)
 		return xsk_umem_peek_addr(umem, addr);

 	*addr = rq->handles[rq->length - 1];
 	return addr;
 }

 static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
 {
 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

 	if (!rq->length)
 		xsk_umem_discard_addr(umem);
 	else
 		rq->length--;
 }

 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
 {
 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

 	rq->handles[rq->length++] = addr;
 }

 /* Handle the offset appropriately depending on aligned or unaligned mode.
  * For unaligned mode, we store the offset in the upper 16-bits of the address.
  * For aligned mode, we simply add the offset to the address.
  */
 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
 					 u64 offset)
 {
 	if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG)
 		return address + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
 	else
 		return address + offset;
 }
 #else
 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 {
 	return -ENOTSUPP;
 }

 static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
 {
 	return false;
 }

 static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
 {
 	return false;
 }

 static inline u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
 {
 	return NULL;
 }

 static inline void xsk_umem_discard_addr(struct xdp_umem *umem)
 {
 }

 static inline void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
 {
 }

 static inline bool xsk_umem_consume_tx(struct xdp_umem *umem,
 				       struct xdp_desc *desc)
 {
 	return false;
 }

 static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
 {
 }

 static inline struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
 {
 	return NULL;
 }

 static inline struct xdp_umem_fq_reuse *xsk_reuseq_swap(
 	struct xdp_umem *umem,
 	struct xdp_umem_fq_reuse *newq)
 {
 	return NULL;
 }
 static inline void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
 {
 }

 static inline struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
 						     u16 queue_id)
 {
 	return NULL;
 }

 static inline u64 xsk_umem_extract_addr(u64 addr)
 {
 	return 0;
 }

 static inline u64 xsk_umem_extract_offset(u64 addr)
 {
 	return 0;
 }

 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
 {
 	return 0;
 }

 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
 {
 	return NULL;
 }

 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
 {
 	return 0;
 }

 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
 {
 	return false;
 }

 static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
 {
 	return NULL;
 }

 static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
 {
 }

 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
 {
 }

 static inline void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
 {
 }

 static inline void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
 {
 }

 static inline void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
 {
 }

 static inline void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
 {
 }

 static inline bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
 {
 	return false;
 }

 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
 					 u64 offset)
 {
 	return 0;
 }

 static inline int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,
 				     struct xdp_sock *xs)
 {
 	return -EOPNOTSUPP;
 }

 static inline void __xsk_map_flush(struct bpf_map *map)
 {
 }

 static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
 						     u32 key)
 {
 	return NULL;
 }
 #endif /* CONFIG_XDP_SOCKETS */

 #endif /* _LINUX_XDP_SOCK_H */
	/* SPDX-License-Identifier: GPL-2.0 */
	/* AF_XDP internal functions
	* Copyright(c) 2018 Intel Corporation.
	*/

	#ifndef _LINUX_XDP_SOCK_H
	#define _LINUX_XDP_SOCK_H

	#include <linux/workqueue.h>
	#include <linux/if_xdp.h>
	#include <linux/mutex.h>
	#include <linux/spinlock.h>
	#include <linux/mm.h>
	#include <net/sock.h>

	struct net_device;
	struct xsk_queue;

	/* Masks for xdp_umem_page flags.
	* The low 12-bits of the addr will be 0 since this is the page address, so we
	* can use them for flags.
	*/
	#define XSK_NEXT_PG_CONTIG_SHIFT 0
	#define XSK_NEXT_PG_CONTIG_MASK (1ULL << XSK_NEXT_PG_CONTIG_SHIFT)

	struct xdp_umem_page {
	void *addr;
	dma_addr_t dma;
	};

	struct xdp_umem_fq_reuse {
	u32 nentries;
	u32 length;
	u64 handles[];
	};

	/* Flags for the umem flags field.
	*
	* The NEED_WAKEUP flag is 1 due to the reuse of the flags field for public
	* flags. See inlude/uapi/include/linux/if_xdp.h.
	*/
	#define XDP_UMEM_USES_NEED_WAKEUP (1 << 1)

	struct xdp_umem {
	struct xsk_queue *fq;
	struct xsk_queue *cq;
	struct xdp_umem_page *pages;
	u64 chunk_mask;
	u64 size;
	u32 headroom;
	u32 chunk_size_nohr;
	struct user_struct *user;
	unsigned long address;
	refcount_t users;
	struct work_struct work;
	struct page **pgs;
	u32 npgs;
	u16 queue_id;
	u8 need_wakeup;
	u8 flags;
	int id;
	struct net_device *dev;
	struct xdp_umem_fq_reuse *fq_reuse;
	bool zc;
	spinlock_t xsk_list_lock;
	struct list_head xsk_list;
	};

	/* Nodes are linked in the struct xdp_sock map_list field, and used to
	* track which maps a certain socket reside in.
	*/

	struct xsk_map {
	struct bpf_map map;
	struct list_head __percpu *flush_list;
	spinlock_t lock; /* Synchronize map updates */
	struct xdp_sock *xsk_map[];
	};

	struct xsk_map_node {
	struct list_head node;
	struct xsk_map *map;
	struct xdp_sock **map_entry;
	};

	struct xdp_sock {
	/* struct sock must be the first member of struct xdp_sock */
	struct sock sk;
	struct xsk_queue *rx;
	struct net_device *dev;
	struct xdp_umem *umem;
	struct list_head flush_node;
	u16 queue_id;
	bool zc;
	enum {
	XSK_READY = 0,
	XSK_BOUND,
	XSK_UNBOUND,
	} state;
	/* Protects multiple processes in the control path */
	struct mutex mutex;
	struct xsk_queue *tx ____cacheline_aligned_in_smp;
	struct list_head list;
	/* Mutual exclusion of NAPI TX thread and sendmsg error paths
	* in the SKB destructor callback.
	*/
	spinlock_t tx_completion_lock;
	/* Protects generic receive. */
	spinlock_t rx_lock;
	u64 rx_dropped;
	struct list_head map_list;
	/* Protects map_list */
	spinlock_t map_list_lock;
	};

	struct xdp_buff;
	#ifdef CONFIG_XDP_SOCKETS
	int xsk_generic_rcv(struct xdp_sock xs, struct xdp_buff xdp);
	bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
	/* Used from netdev driver */
	bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
	u64 xsk_umem_peek_addr(struct xdp_umem umem, u64 *addr);
	void xsk_umem_discard_addr(struct xdp_umem *umem);
	void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
	bool xsk_umem_consume_tx(struct xdp_umem umem, struct xdp_desc desc);
	void xsk_umem_consume_tx_done(struct xdp_umem *umem);
	struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
	struct xdp_umem_fq_reuse xsk_reuseq_swap(struct xdp_umem umem,
	struct xdp_umem_fq_reuse *newq);
	void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq);
	struct xdp_umem xdp_get_umem_from_qid(struct net_device dev, u16 queue_id);
	void xsk_set_rx_need_wakeup(struct xdp_umem *umem);
	void xsk_set_tx_need_wakeup(struct xdp_umem *umem);
	void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
	void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
	bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);

	void xsk_map_try_sock_delete(struct xsk_map map, struct xdp_sock xs,
	struct xdp_sock **map_entry);
	int xsk_map_inc(struct xsk_map *map);
	void xsk_map_put(struct xsk_map *map);
	int __xsk_map_redirect(struct bpf_map map, struct xdp_buff xdp,
	struct xdp_sock *xs);
	void __xsk_map_flush(struct bpf_map *map);

	static inline struct xdp_sock __xsk_map_lookup_elem(struct bpf_map map,
	u32 key)
	{
	struct xsk_map *m = container_of(map, struct xsk_map, map);
	struct xdp_sock *xs;

	if (key >= map->max_entries)
	return NULL;

	xs = READ_ONCE(m->xsk_map[key]);
	return xs;
	}

	static inline u64 xsk_umem_extract_addr(u64 addr)
	{
	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
	}

	static inline u64 xsk_umem_extract_offset(u64 addr)
	{
	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
	}

	static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
	{
	return xsk_umem_extract_addr(addr) + xsk_umem_extract_offset(addr);
	}

	static inline char xdp_umem_get_data(struct xdp_umem umem, u64 addr)
	{
	unsigned long page_addr;

	addr = xsk_umem_add_offset_to_addr(addr);
	page_addr = (unsigned long)umem->pages[addr >> PAGE_SHIFT].addr;

	return (char *)(page_addr & PAGE_MASK) + (addr & ~PAGE_MASK);
	}

	static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
	{
	addr = xsk_umem_add_offset_to_addr(addr);

	return umem->pages[addr >> PAGE_SHIFT].dma + (addr & ~PAGE_MASK);
	}

	/* Reuse-queue aware version of FILL queue helpers */
	static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
	{
	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

	if (rq->length >= cnt)
	return true;

	return xsk_umem_has_addrs(umem, cnt - rq->length);
	}

	static inline u64 xsk_umem_peek_addr_rq(struct xdp_umem umem, u64 *addr)
	{
	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

	if (!rq->length)
	return xsk_umem_peek_addr(umem, addr);

	*addr = rq->handles[rq->length - 1];
	return addr;
	}

	static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
	{
	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

	if (!rq->length)
	xsk_umem_discard_addr(umem);
	else
	rq->length--;
	}

	static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
	{
	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;

	rq->handles[rq->length++] = addr;
	}

	/* Handle the offset appropriately depending on aligned or unaligned mode.
	* For unaligned mode, we store the offset in the upper 16-bits of the address.
	* For aligned mode, we simply add the offset to the address.
	*/
	static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
	u64 offset)
	{
	if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG)
	return address + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
	else
	return address + offset;
	}
	#else
	static inline int xsk_generic_rcv(struct xdp_sock xs, struct xdp_buff xdp)
	{
	return -ENOTSUPP;
	}

	static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
	{
	return false;
	}

	static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
	{
	return false;
	}

	static inline u64 xsk_umem_peek_addr(struct xdp_umem umem, u64 *addr)
	{
	return NULL;
	}

	static inline void xsk_umem_discard_addr(struct xdp_umem *umem)
	{
	}

	static inline void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
	{
	}

	static inline bool xsk_umem_consume_tx(struct xdp_umem *umem,
	struct xdp_desc *desc)
	{
	return false;
	}

	static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
	{
	}

	static inline struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
	{
	return NULL;
	}

	static inline struct xdp_umem_fq_reuse *xsk_reuseq_swap(
	struct xdp_umem *umem,
	struct xdp_umem_fq_reuse *newq)
	{
	return NULL;
	}
	static inline void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
	{
	}

	static inline struct xdp_umem xdp_get_umem_from_qid(struct net_device dev,
	u16 queue_id)
	{
	return NULL;
	}

	static inline u64 xsk_umem_extract_addr(u64 addr)
	{
	return 0;
	}

	static inline u64 xsk_umem_extract_offset(u64 addr)
	{
	return 0;
	}

	static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
	{
	return 0;
	}

	static inline char xdp_umem_get_data(struct xdp_umem umem, u64 addr)
	{
	return NULL;
	}

	static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
	{
	return 0;
	}

	static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
	{
	return false;
	}

	static inline u64 xsk_umem_peek_addr_rq(struct xdp_umem umem, u64 *addr)
	{
	return NULL;
	}

	static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
	{
	}

	static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
	{
	}

	static inline void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
	{
	}

	static inline void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
	{
	}

	static inline void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
	{
	}

	static inline void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
	{
	}

	static inline bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
	{
	return false;
	}

	static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
	u64 offset)
	{
	return 0;
	}

	static inline int __xsk_map_redirect(struct bpf_map map, struct xdp_buff xdp,
	struct xdp_sock *xs)
	{
	return -EOPNOTSUPP;
	}

	static inline void __xsk_map_flush(struct bpf_map *map)
	{
	}

	static inline struct xdp_sock __xsk_map_lookup_elem(struct bpf_map map,
	u32 key)
	{
	return NULL;
	}
	#endif /* CONFIG_XDP_SOCKETS */

	#endif /* _LINUX_XDP_SOCK_H */