/*
   * Linux Socket Filter Data Structures
   */

  #ifndef __LINUX_FILTER_H__
  #define __LINUX_FILTER_H__

  #include <stdarg.h>

  #include <linux/atomic.h>

  #include <linux/compat.h>

  #include <linux/skbuff.h>

  #include <linux/linkage.h>
  #include <linux/printk.h>

  #include <linux/workqueue.h>

  #include <linux/sched.h>

  #include <net/sch_generic.h>

  #include <asm/cacheflush.h>

  
  #include <uapi/linux/filter.h>

  #include <uapi/linux/bpf.h>

  
  struct sk_buff;
  struct sock;
  struct seccomp_data;

  struct bpf_prog_aux;

  /* ArgX, context and stack frame pointer register positions. Note,
   * Arg1, Arg2, Arg3, etc are used as argument mappings of function
   * calls in BPF_CALL instruction.
   */
  #define BPF_REG_ARG1	BPF_REG_1
  #define BPF_REG_ARG2	BPF_REG_2
  #define BPF_REG_ARG3	BPF_REG_3
  #define BPF_REG_ARG4	BPF_REG_4
  #define BPF_REG_ARG5	BPF_REG_5
  #define BPF_REG_CTX	BPF_REG_6
  #define BPF_REG_FP	BPF_REG_10
  
  /* Additional register mappings for converted user programs. */
  #define BPF_REG_A	BPF_REG_0
  #define BPF_REG_X	BPF_REG_7
  #define BPF_REG_TMP	BPF_REG_8

  
  /* BPF program can access up to 512 bytes of stack space. */
  #define MAX_BPF_STACK	512

  /* Helper macros for filter block array initializers. */

  /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */

  #define BPF_ALU64_REG(OP, DST, SRC)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = 0 })

  #define BPF_ALU32_REG(OP, DST, SRC)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = 0 })

  /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */

  #define BPF_ALU64_IMM(OP, DST, IMM)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = IMM })

  #define BPF_ALU32_IMM(OP, DST, IMM)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = IMM })
  
  /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */

  #define BPF_ENDIAN(TYPE, DST, LEN)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),	\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = LEN })

  /* Short form of mov, dst_reg = src_reg */

  #define BPF_MOV64_REG(DST, SRC)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = 0 })

  #define BPF_MOV32_REG(DST, SRC)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_MOV | BPF_X,		\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = 0 })

  /* Short form of mov, dst_reg = imm32 */

  #define BPF_MOV64_IMM(DST, IMM)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = IMM })

  #define BPF_MOV32_IMM(DST, IMM)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_MOV | BPF_K,		\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = IMM })

  /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  #define BPF_LD_IMM64(DST, IMM)					\
  	BPF_LD_IMM64_RAW(DST, 0, IMM)
  
  #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = 0,					\
  		.imm   = (__u32) (IMM) }),			\
  	((struct bpf_insn) {					\
  		.code  = 0, /* zero is reserved opcode */	\
  		.dst_reg = 0,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = ((__u64) (IMM)) >> 32 })

  /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
  #define BPF_LD_MAP_FD(DST, MAP_FD)				\
  	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)

  /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */

  #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)			\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),	\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = IMM })

  #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)			\

  	((struct bpf_insn) {					\

  		.code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),	\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\
  		.imm   = IMM })

  /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */

  #define BPF_LD_ABS(SIZE, IMM)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\

  		.dst_reg = 0,					\
  		.src_reg = 0,					\

  		.off   = 0,					\

  		.imm   = IMM })

  /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */

  #define BPF_LD_IND(SIZE, SRC, IMM)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,	\

  		.dst_reg = 0,					\
  		.src_reg = SRC,					\

  		.off   = 0,					\

  		.imm   = IMM })

  /* Memory load, dst_reg = *(uint *) (src_reg + off16) */

  #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\

  	((struct bpf_insn) {					\

  		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = OFF,					\
  		.imm   = 0 })

  /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
  
  #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\

  	((struct bpf_insn) {					\

  		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = OFF,					\
  		.imm   = 0 })

  /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
  
  #define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\
  	((struct bpf_insn) {					\
  		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,	\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = OFF,					\
  		.imm   = 0 })

  /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
  
  #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */

  #define BPF_JMP_REG(OP, DST, SRC, OFF)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = OFF,					\
  		.imm   = 0 })

  /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */

  #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\

  	((struct bpf_insn) {					\

  		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\

  		.dst_reg = DST,					\
  		.src_reg = 0,					\

  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Function call */
  
  #define BPF_EMIT_CALL(FUNC)					\

  	((struct bpf_insn) {					\

  		.code  = BPF_JMP | BPF_CALL,			\

  		.dst_reg = 0,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = ((FUNC) - __bpf_call_base) })
  
  /* Raw code statement block */

  #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\

  	((struct bpf_insn) {					\

  		.code  = CODE,					\

  		.dst_reg = DST,					\
  		.src_reg = SRC,					\

  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Program exit */
  
  #define BPF_EXIT_INSN()						\

  	((struct bpf_insn) {					\

  		.code  = BPF_JMP | BPF_EXIT,			\

  		.dst_reg = 0,					\
  		.src_reg = 0,					\

  		.off   = 0,					\
  		.imm   = 0 })

  /* Internal classic blocks for direct assignment */
  
  #define __BPF_STMT(CODE, K)					\
  	((struct sock_filter) BPF_STMT(CODE, K))
  
  #define __BPF_JUMP(CODE, K, JT, JF)				\
  	((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))

  #define bytes_to_bpf_size(bytes)				\
  ({								\
  	int bpf_size = -EINVAL;					\
  								\
  	if (bytes == sizeof(u8))				\
  		bpf_size = BPF_B;				\
  	else if (bytes == sizeof(u16))				\
  		bpf_size = BPF_H;				\
  	else if (bytes == sizeof(u32))				\
  		bpf_size = BPF_W;				\
  	else if (bytes == sizeof(u64))				\
  		bpf_size = BPF_DW;				\
  								\
  	bpf_size;						\
  })

  #ifdef CONFIG_COMPAT
  /* A struct sock_filter is architecture independent. */

  struct compat_sock_fprog {
  	u16		len;

  	compat_uptr_t	filter;	/* struct sock_filter * */

  };
  #endif

  struct sock_fprog_kern {
  	u16			len;
  	struct sock_filter	*filter;
  };

  struct bpf_binary_header {
  	unsigned int pages;
  	u8 image[];
  };

  struct bpf_prog {

  	u16			pages;		/* Number of allocated pages */

  	kmemcheck_bitfield_begin(meta);
  	u16			jited:1,	/* Is our filter JIT'ed? */

  				gpl_compatible:1, /* Is filter GPL compatible? */

  				cb_access:1,	/* Is control block accessed? */

  				dst_needed:1;	/* Do we need dst entry? */

  	kmemcheck_bitfield_end(meta);

  	u32			len;		/* Number of filter blocks */

  	enum bpf_prog_type	type;		/* Type of BPF program */

  	struct bpf_prog_aux	*aux;		/* Auxiliary fields */

  	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */

  	unsigned int		(*bpf_func)(const struct sk_buff *skb,

  					    const struct bpf_insn *filter);

  	/* Instructions for interpreter */

  	union {

  		struct sock_filter	insns[0];

  		struct bpf_insn		insnsi[0];

  	};

  };

  struct sk_filter {
  	atomic_t	refcnt;
  	struct rcu_head	rcu;
  	struct bpf_prog	*prog;
  };
  
  #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)

  static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
  				       struct sk_buff *skb)
  {
  	u8 *cb_data = qdisc_skb_cb(skb)->data;
  	u8 saved_cb[QDISC_CB_PRIV_LEN];
  	u32 res;
  
  	BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
  		     QDISC_CB_PRIV_LEN);
  
  	if (unlikely(prog->cb_access)) {
  		memcpy(saved_cb, cb_data, sizeof(saved_cb));
  		memset(cb_data, 0, sizeof(saved_cb));
  	}
  
  	res = BPF_PROG_RUN(prog, skb);
  
  	if (unlikely(prog->cb_access))
  		memcpy(cb_data, saved_cb, sizeof(saved_cb));
  
  	return res;
  }
  
  static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
  					struct sk_buff *skb)
  {
  	u8 *cb_data = qdisc_skb_cb(skb)->data;
  
  	if (unlikely(prog->cb_access))
  		memset(cb_data, 0, QDISC_CB_PRIV_LEN);
  	return BPF_PROG_RUN(prog, skb);
  }

  static inline unsigned int bpf_prog_size(unsigned int proglen)

  {

  	return max(sizeof(struct bpf_prog),
  		   offsetof(struct bpf_prog, insns[proglen]));

  }

  static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
  {
  	/* When classic BPF programs have been loaded and the arch
  	 * does not have a classic BPF JIT (anymore), they have been
  	 * converted via bpf_migrate_filter() to eBPF and thus always
  	 * have an unspec program type.
  	 */
  	return prog->type == BPF_PROG_TYPE_UNSPEC;
  }

  #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))

  #ifdef CONFIG_DEBUG_SET_MODULE_RONX
  static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
  {
  	set_memory_ro((unsigned long)fp, fp->pages);
  }
  
  static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
  {
  	set_memory_rw((unsigned long)fp, fp->pages);
  }
  #else
  static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
  {
  }
  
  static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
  {
  }
  #endif /* CONFIG_DEBUG_SET_MODULE_RONX */

  int sk_filter(struct sock *sk, struct sk_buff *skb);

  int bpf_prog_select_runtime(struct bpf_prog *fp);

  void bpf_prog_free(struct bpf_prog *fp);

  struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
  struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
  				  gfp_t gfp_extra_flags);
  void __bpf_prog_free(struct bpf_prog *fp);
  
  static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
  {
  	bpf_prog_unlock_ro(fp);
  	__bpf_prog_free(fp);
  }

  typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
  				       unsigned int flen);

  int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);

  int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,

  			      bpf_aux_classic_check_t trans, bool save_orig);

  void bpf_prog_destroy(struct bpf_prog *fp);

  int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);

  int sk_attach_bpf(u32 ufd, struct sock *sk);

  int sk_detach_filter(struct sock *sk);

  int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
  		  unsigned int len);

  bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);

  void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);

  u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

  void bpf_int_jit_compile(struct bpf_prog *fp);

  bool bpf_helper_changes_skb_data(void *func);

  #ifdef CONFIG_BPF_JIT
  typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
  
  struct bpf_binary_header *
  bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
  		     unsigned int alignment,
  		     bpf_jit_fill_hole_t bpf_fill_ill_insns);
  void bpf_jit_binary_free(struct bpf_binary_header *hdr);
  
  void bpf_jit_compile(struct bpf_prog *fp);
  void bpf_jit_free(struct bpf_prog *fp);
  
  static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
  				u32 pass, void *image)
  {

  	pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d
  ", flen,
  	       proglen, pass, image, current->comm, task_pid_nr(current));

  	if (image)
  		print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
  			       16, 1, image, proglen, false);
  }
  #else
  static inline void bpf_jit_compile(struct bpf_prog *fp)
  {
  }
  
  static inline void bpf_jit_free(struct bpf_prog *fp)
  {
  	bpf_prog_unlock_free(fp);
  }
  #endif /* CONFIG_BPF_JIT */

  #define BPF_ANC		BIT(15)

  static inline bool bpf_needs_clear_a(const struct sock_filter *first)
  {
  	switch (first->code) {
  	case BPF_RET | BPF_K:
  	case BPF_LD | BPF_W | BPF_LEN:
  		return false;
  
  	case BPF_LD | BPF_W | BPF_ABS:
  	case BPF_LD | BPF_H | BPF_ABS:
  	case BPF_LD | BPF_B | BPF_ABS:
  		if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
  			return true;
  		return false;
  
  	default:
  		return true;
  	}
  }

  static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
  {
  	BUG_ON(ftest->code & BPF_ANC);
  
  	switch (ftest->code) {
  	case BPF_LD | BPF_W | BPF_ABS:
  	case BPF_LD | BPF_H | BPF_ABS:
  	case BPF_LD | BPF_B | BPF_ABS:
  #define BPF_ANCILLARY(CODE)	case SKF_AD_OFF + SKF_AD_##CODE:	\
  				return BPF_ANC | SKF_AD_##CODE
  		switch (ftest->k) {
  		BPF_ANCILLARY(PROTOCOL);
  		BPF_ANCILLARY(PKTTYPE);
  		BPF_ANCILLARY(IFINDEX);
  		BPF_ANCILLARY(NLATTR);
  		BPF_ANCILLARY(NLATTR_NEST);
  		BPF_ANCILLARY(MARK);
  		BPF_ANCILLARY(QUEUE);
  		BPF_ANCILLARY(HATYPE);
  		BPF_ANCILLARY(RXHASH);
  		BPF_ANCILLARY(CPU);
  		BPF_ANCILLARY(ALU_XOR_X);
  		BPF_ANCILLARY(VLAN_TAG);
  		BPF_ANCILLARY(VLAN_TAG_PRESENT);
  		BPF_ANCILLARY(PAY_OFFSET);
  		BPF_ANCILLARY(RANDOM);

  		BPF_ANCILLARY(VLAN_TPID);

  		}
  		/* Fallthrough. */
  	default:
  		return ftest->code;
  	}
  }

  void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
  					   int k, unsigned int size);
  
  static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
  				     unsigned int size, void *buffer)
  {
  	if (k >= 0)
  		return skb_header_pointer(skb, k, size, buffer);
  
  	return bpf_internal_load_pointer_neg_helper(skb, k, size);
  }

  static inline int bpf_tell_extensions(void)
  {

  	return SKF_AD_MAX;

  }

  #endif /* __LINUX_FILTER_H__ */