include/uapi/linux/bpf.h - kernel/msm-4.19 - Gitiles

 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
 #ifndef _UAPI__LINUX_BPF_H__
 #define _UAPI__LINUX_BPF_H__

 #include <linux/types.h>
 #include <linux/bpf_common.h>

 /* Extended instruction set based on top of classic BPF */

 /* instruction classes */
 #define BPF_ALU64	0x07	/* alu mode in double word width */

 /* ld/ldx fields */
 #define BPF_DW		0x18	/* double word */
 #define BPF_XADD	0xc0	/* exclusive add */

 /* alu/jmp fields */
 #define BPF_MOV		0xb0	/* mov reg to reg */
 #define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */

 /* change endianness of a register */
 #define BPF_END		0xd0	/* flags for endianness conversion: */
 #define BPF_TO_LE	0x00	/* convert to little-endian */
 #define BPF_TO_BE	0x08	/* convert to big-endian */
 #define BPF_FROM_LE	BPF_TO_LE
 #define BPF_FROM_BE	BPF_TO_BE

 #define BPF_JNE		0x50	/* jump != */
 #define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
 #define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
 #define BPF_CALL	0x80	/* function call */
 #define BPF_EXIT	0x90	/* function return */

 /* Register numbers */
 enum {
 	BPF_REG_0 = 0,
 	BPF_REG_1,
 	BPF_REG_2,
 	BPF_REG_3,
 	BPF_REG_4,
 	BPF_REG_5,
 	BPF_REG_6,
 	BPF_REG_7,
 	BPF_REG_8,
 	BPF_REG_9,
 	BPF_REG_10,
 	__MAX_BPF_REG,
 };

 /* BPF has 10 general purpose 64-bit registers and stack frame. */
 #define MAX_BPF_REG	__MAX_BPF_REG

 struct bpf_insn {
 	__u8	code;		/* opcode */
 	__u8	dst_reg:4;	/* dest register */
 	__u8	src_reg:4;	/* source register */
 	__s16	off;		/* signed offset */
 	__s32	imm;		/* signed immediate constant */
 };

 /* BPF syscall commands, see bpf(2) man-page for details. */
 enum bpf_cmd {
 	BPF_MAP_CREATE,
 	BPF_MAP_LOOKUP_ELEM,
 	BPF_MAP_UPDATE_ELEM,
 	BPF_MAP_DELETE_ELEM,
 	BPF_MAP_GET_NEXT_KEY,
 	BPF_PROG_LOAD,
 	BPF_OBJ_PIN,
 	BPF_OBJ_GET,
 };

 enum bpf_map_type {
 	BPF_MAP_TYPE_UNSPEC,
 	BPF_MAP_TYPE_HASH,
 	BPF_MAP_TYPE_ARRAY,
 	BPF_MAP_TYPE_PROG_ARRAY,
 	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
 	BPF_MAP_TYPE_PERCPU_HASH,
 	BPF_MAP_TYPE_PERCPU_ARRAY,
 	BPF_MAP_TYPE_STACK_TRACE,
 	BPF_MAP_TYPE_CGROUP_ARRAY,
 };

 enum bpf_prog_type {
 	BPF_PROG_TYPE_UNSPEC,
 	BPF_PROG_TYPE_SOCKET_FILTER,
 	BPF_PROG_TYPE_KPROBE,
 	BPF_PROG_TYPE_SCHED_CLS,
 	BPF_PROG_TYPE_SCHED_ACT,
 	BPF_PROG_TYPE_TRACEPOINT,
 	BPF_PROG_TYPE_XDP,
 };

 #define BPF_PSEUDO_MAP_FD	1

 /* flags for BPF_MAP_UPDATE_ELEM command */
 #define BPF_ANY		0 /* create new element or update existing */
 #define BPF_NOEXIST	1 /* create new element if it didn't exist */
 #define BPF_EXIST	2 /* update existing element */

 #define BPF_F_NO_PREALLOC	(1U << 0)

 union bpf_attr {
 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
 		__u32	map_type;	/* one of enum bpf_map_type */
 		__u32	key_size;	/* size of key in bytes */
 		__u32	value_size;	/* size of value in bytes */
 		__u32	max_entries;	/* max number of entries in a map */
 		__u32	map_flags;	/* prealloc or not */
 	};

 	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
 		__u32		map_fd;
 		__aligned_u64	key;
 		union {
 			__aligned_u64 value;
 			__aligned_u64 next_key;
 		};
 		__u64		flags;
 	};

 	struct { /* anonymous struct used by BPF_PROG_LOAD command */
 		__u32		prog_type;	/* one of enum bpf_prog_type */
 		__u32		insn_cnt;
 		__aligned_u64	insns;
 		__aligned_u64	license;
 		__u32		log_level;	/* verbosity level of verifier */
 		__u32		log_size;	/* size of user buffer */
 		__aligned_u64	log_buf;	/* user supplied buffer */
 		__u32		kern_version;	/* checked when prog_type=kprobe */
 	};

 	struct { /* anonymous struct used by BPF_OBJ_* commands */
 		__aligned_u64	pathname;
 		__u32		bpf_fd;
 	};
 } __attribute__((aligned(8)));

 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
  */
 enum bpf_func_id {
 	BPF_FUNC_unspec,
 	BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
 	BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
 	BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
 	BPF_FUNC_probe_read,      /* int bpf_probe_read(void *dst, int size, void *src) */
 	BPF_FUNC_ktime_get_ns,    /* u64 bpf_ktime_get_ns(void) */
 	BPF_FUNC_trace_printk,    /* int bpf_trace_printk(const char *fmt, int fmt_size, ...) */
 	BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
 	BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */

 	/**
 	 * skb_store_bytes(skb, offset, from, len, flags) - store bytes into packet
 	 * @skb: pointer to skb
 	 * @offset: offset within packet from skb->mac_header
 	 * @from: pointer where to copy bytes from
 	 * @len: number of bytes to store into packet
 	 * @flags: bit 0 - if true, recompute skb->csum
 	 *         other bits - reserved
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_skb_store_bytes,

 	/**
 	 * l3_csum_replace(skb, offset, from, to, flags) - recompute IP checksum
 	 * @skb: pointer to skb
 	 * @offset: offset within packet where IP checksum is located
 	 * @from: old value of header field
 	 * @to: new value of header field
 	 * @flags: bits 0-3 - size of header field
 	 *         other bits - reserved
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_l3_csum_replace,

 	/**
 	 * l4_csum_replace(skb, offset, from, to, flags) - recompute TCP/UDP checksum
 	 * @skb: pointer to skb
 	 * @offset: offset within packet where TCP/UDP checksum is located
 	 * @from: old value of header field
 	 * @to: new value of header field
 	 * @flags: bits 0-3 - size of header field
 	 *         bit 4 - is pseudo header
 	 *         other bits - reserved
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_l4_csum_replace,

 	/**
 	 * bpf_tail_call(ctx, prog_array_map, index) - jump into another BPF program
 	 * @ctx: context pointer passed to next program
 	 * @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
 	 * @index: index inside array that selects specific program to run
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_tail_call,

 	/**
 	 * bpf_clone_redirect(skb, ifindex, flags) - redirect to another netdev
 	 * @skb: pointer to skb
 	 * @ifindex: ifindex of the net device
 	 * @flags: bit 0 - if set, redirect to ingress instead of egress
 	 *         other bits - reserved
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_clone_redirect,

 	/**
 	 * u64 bpf_get_current_pid_tgid(void)
 	 * Return: current->tgid << 32 | current->pid
 	 */
 	BPF_FUNC_get_current_pid_tgid,

 	/**
 	 * u64 bpf_get_current_uid_gid(void)
 	 * Return: current_gid << 32 | current_uid
 	 */
 	BPF_FUNC_get_current_uid_gid,

 	/**
 	 * bpf_get_current_comm(char *buf, int size_of_buf)
 	 * stores current->comm into buf
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_get_current_comm,

 	/**
 	 * bpf_get_cgroup_classid(skb) - retrieve a proc's classid
 	 * @skb: pointer to skb
 	 * Return: classid if != 0
 	 */
 	BPF_FUNC_get_cgroup_classid,
 	BPF_FUNC_skb_vlan_push, /* bpf_skb_vlan_push(skb, vlan_proto, vlan_tci) */
 	BPF_FUNC_skb_vlan_pop,  /* bpf_skb_vlan_pop(skb) */

 	/**
 	 * bpf_skb_[gs]et_tunnel_key(skb, key, size, flags)
 	 * retrieve or populate tunnel metadata
 	 * @skb: pointer to skb
 	 * @key: pointer to 'struct bpf_tunnel_key'
 	 * @size: size of 'struct bpf_tunnel_key'
 	 * @flags: room for future extensions
 	 * Retrun: 0 on success
 	 */
 	BPF_FUNC_skb_get_tunnel_key,
 	BPF_FUNC_skb_set_tunnel_key,
 	BPF_FUNC_perf_event_read,	/* u64 bpf_perf_event_read(&map, index) */
 	/**
 	 * bpf_redirect(ifindex, flags) - redirect to another netdev
 	 * @ifindex: ifindex of the net device
 	 * @flags: bit 0 - if set, redirect to ingress instead of egress
 	 *         other bits - reserved
 	 * Return: TC_ACT_REDIRECT
 	 */
 	BPF_FUNC_redirect,

 	/**
 	 * bpf_get_route_realm(skb) - retrieve a dst's tclassid
 	 * @skb: pointer to skb
 	 * Return: realm if != 0
 	 */
 	BPF_FUNC_get_route_realm,

 	/**
 	 * bpf_perf_event_output(ctx, map, index, data, size) - output perf raw sample
 	 * @ctx: struct pt_regs*
 	 * @map: pointer to perf_event_array map
 	 * @index: index of event in the map
 	 * @data: data on stack to be output as raw data
 	 * @size: size of data
 	 * Return: 0 on success
 	 */
 	BPF_FUNC_perf_event_output,
 	BPF_FUNC_skb_load_bytes,

 	/**
 	 * bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
 	 * @ctx: struct pt_regs*
 	 * @map: pointer to stack_trace map
 	 * @flags: bits 0-7 - numer of stack frames to skip
 	 *         bit 8 - collect user stack instead of kernel
 	 *         bit 9 - compare stacks by hash only
 	 *         bit 10 - if two different stacks hash into the same stackid
 	 *                  discard old
 	 *         other bits - reserved
 	 * Return: >= 0 stackid on success or negative error
 	 */
 	BPF_FUNC_get_stackid,

 	/**
 	 * bpf_csum_diff(from, from_size, to, to_size, seed) - calculate csum diff
 	 * @from: raw from buffer
 	 * @from_size: length of from buffer
 	 * @to: raw to buffer
 	 * @to_size: length of to buffer
 	 * @seed: optional seed
 	 * Return: csum result
 	 */
 	BPF_FUNC_csum_diff,

 	/**
 	 * bpf_skb_[gs]et_tunnel_opt(skb, opt, size)
 	 * retrieve or populate tunnel options metadata
 	 * @skb: pointer to skb
 	 * @opt: pointer to raw tunnel option data
 	 * @size: size of @opt
 	 * Return: 0 on success for set, option size for get
 	 */
 	BPF_FUNC_skb_get_tunnel_opt,
 	BPF_FUNC_skb_set_tunnel_opt,

 	/**
 	 * bpf_skb_change_proto(skb, proto, flags)
 	 * Change protocol of the skb. Currently supported is
 	 * v4 -> v6, v6 -> v4 transitions. The helper will also
 	 * resize the skb. eBPF program is expected to fill the
 	 * new headers via skb_store_bytes and lX_csum_replace.
 	 * @skb: pointer to skb
 	 * @proto: new skb->protocol type
 	 * @flags: reserved
 	 * Return: 0 on success or negative error
 	 */
 	BPF_FUNC_skb_change_proto,

 	/**
 	 * bpf_skb_change_type(skb, type)
 	 * Change packet type of skb.
 	 * @skb: pointer to skb
 	 * @type: new skb->pkt_type type
 	 * Return: 0 on success or negative error
 	 */
 	BPF_FUNC_skb_change_type,

 	/**
 	 * bpf_skb_under_cgroup(skb, map, index) - Check cgroup2 membership of skb
 	 * @skb: pointer to skb
 	 * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
 	 * @index: index of the cgroup in the bpf_map
 	 * Return:
 	 *   == 0 skb failed the cgroup2 descendant test
 	 *   == 1 skb succeeded the cgroup2 descendant test
 	 *    < 0 error
 	 */
 	BPF_FUNC_skb_under_cgroup,

 	/**
 	 * bpf_get_hash_recalc(skb)
 	 * Retrieve and possibly recalculate skb->hash.
 	 * @skb: pointer to skb
 	 * Return: hash
 	 */
 	BPF_FUNC_get_hash_recalc,

 	/**
 	 * u64 bpf_get_current_task(void)
 	 * Returns current task_struct
 	 * Return: current
 	 */
 	BPF_FUNC_get_current_task,

 	/**
 	 * bpf_probe_write_user(void *dst, void *src, int len)
 	 * safely attempt to write to a location
 	 * @dst: destination address in userspace
 	 * @src: source address on stack
 	 * @len: number of bytes to copy
 	 * Return: 0 on success or negative error
 	 */
 	BPF_FUNC_probe_write_user,

 	__BPF_FUNC_MAX_ID,
 };

 /* All flags used by eBPF helper functions, placed here. */

 /* BPF_FUNC_skb_store_bytes flags. */
 #define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
 #define BPF_F_INVALIDATE_HASH		(1ULL << 1)

 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
  * First 4 bits are for passing the header field size.
  */
 #define BPF_F_HDR_FIELD_MASK		0xfULL

 /* BPF_FUNC_l4_csum_replace flags. */
 #define BPF_F_PSEUDO_HDR		(1ULL << 4)
 #define BPF_F_MARK_MANGLED_0		(1ULL << 5)

 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
 #define BPF_F_INGRESS			(1ULL << 0)

 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
 #define BPF_F_TUNINFO_IPV6		(1ULL << 0)

 /* BPF_FUNC_get_stackid flags. */
 #define BPF_F_SKIP_FIELD_MASK		0xffULL
 #define BPF_F_USER_STACK		(1ULL << 8)
 #define BPF_F_FAST_STACK_CMP		(1ULL << 9)
 #define BPF_F_REUSE_STACKID		(1ULL << 10)

 /* BPF_FUNC_skb_set_tunnel_key flags. */
 #define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
 #define BPF_F_DONT_FRAGMENT		(1ULL << 2)

 /* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
 #define BPF_F_INDEX_MASK		0xffffffffULL
 #define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
 /* BPF_FUNC_perf_event_output for sk_buff input context. */
 #define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)

 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
 struct __sk_buff {
 	__u32 len;
 	__u32 pkt_type;
 	__u32 mark;
 	__u32 queue_mapping;
 	__u32 protocol;
 	__u32 vlan_present;
 	__u32 vlan_tci;
 	__u32 vlan_proto;
 	__u32 priority;
 	__u32 ingress_ifindex;
 	__u32 ifindex;
 	__u32 tc_index;
 	__u32 cb[5];
 	__u32 hash;
 	__u32 tc_classid;
 	__u32 data;
 	__u32 data_end;
 };

 struct bpf_tunnel_key {
 	__u32 tunnel_id;
 	union {
 		__u32 remote_ipv4;
 		__u32 remote_ipv6[4];
 	};
 	__u8 tunnel_tos;
 	__u8 tunnel_ttl;
 	__u16 tunnel_ext;
 	__u32 tunnel_label;
 };

 /* User return codes for XDP prog type.
  * A valid XDP program must return one of these defined values. All other
  * return codes are reserved for future use. Unknown return codes will result
  * in packet drop.
  */
 enum xdp_action {
 	XDP_ABORTED = 0,
 	XDP_DROP,
 	XDP_PASS,
 	XDP_TX,
 };

 /* user accessible metadata for XDP packet hook
  * new fields must be added to the end of this structure
  */
 struct xdp_md {
 	__u32 data;
 	__u32 data_end;
 };

 #endif /* _UAPI__LINUX_BPF_H__ */
	/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of version 2 of the GNU General Public
	* License as published by the Free Software Foundation.
	*/
	#ifndef _UAPI__LINUX_BPF_H__
	#define _UAPI__LINUX_BPF_H__

	#include <linux/types.h>
	#include <linux/bpf_common.h>

	/* Extended instruction set based on top of classic BPF */

	/* instruction classes */
	#define BPF_ALU64 0x07 /* alu mode in double word width */

	/* ld/ldx fields */
	#define BPF_DW 0x18 /* double word */
	#define BPF_XADD 0xc0 /* exclusive add */

	/* alu/jmp fields */
	#define BPF_MOV 0xb0 /* mov reg to reg */
	#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */

	/* change endianness of a register */
	#define BPF_END 0xd0 /* flags for endianness conversion: */
	#define BPF_TO_LE 0x00 /* convert to little-endian */
	#define BPF_TO_BE 0x08 /* convert to big-endian */
	#define BPF_FROM_LE BPF_TO_LE
	#define BPF_FROM_BE BPF_TO_BE

	#define BPF_JNE 0x50 /* jump != */
	#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
	#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
	#define BPF_CALL 0x80 /* function call */
	#define BPF_EXIT 0x90 /* function return */

	/* Register numbers */
	enum {
	BPF_REG_0 = 0,
	BPF_REG_1,
	BPF_REG_2,
	BPF_REG_3,
	BPF_REG_4,
	BPF_REG_5,
	BPF_REG_6,
	BPF_REG_7,
	BPF_REG_8,
	BPF_REG_9,
	BPF_REG_10,
	__MAX_BPF_REG,
	};

	/* BPF has 10 general purpose 64-bit registers and stack frame. */
	#define MAX_BPF_REG __MAX_BPF_REG

	struct bpf_insn {
	__u8 code; /* opcode */
	__u8 dst_reg:4; /* dest register */
	__u8 src_reg:4; /* source register */
	__s16 off; /* signed offset */
	__s32 imm; /* signed immediate constant */
	};

	/* BPF syscall commands, see bpf(2) man-page for details. */
	enum bpf_cmd {
	BPF_MAP_CREATE,
	BPF_MAP_LOOKUP_ELEM,
	BPF_MAP_UPDATE_ELEM,
	BPF_MAP_DELETE_ELEM,
	BPF_MAP_GET_NEXT_KEY,
	BPF_PROG_LOAD,
	BPF_OBJ_PIN,
	BPF_OBJ_GET,
	};

	enum bpf_map_type {
	BPF_MAP_TYPE_UNSPEC,
	BPF_MAP_TYPE_HASH,
	BPF_MAP_TYPE_ARRAY,
	BPF_MAP_TYPE_PROG_ARRAY,
	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
	BPF_MAP_TYPE_PERCPU_HASH,
	BPF_MAP_TYPE_PERCPU_ARRAY,
	BPF_MAP_TYPE_STACK_TRACE,
	BPF_MAP_TYPE_CGROUP_ARRAY,
	};

	enum bpf_prog_type {
	BPF_PROG_TYPE_UNSPEC,
	BPF_PROG_TYPE_SOCKET_FILTER,
	BPF_PROG_TYPE_KPROBE,
	BPF_PROG_TYPE_SCHED_CLS,
	BPF_PROG_TYPE_SCHED_ACT,
	BPF_PROG_TYPE_TRACEPOINT,
	BPF_PROG_TYPE_XDP,
	};

	#define BPF_PSEUDO_MAP_FD 1

	/* flags for BPF_MAP_UPDATE_ELEM command */
	#define BPF_ANY 0 /* create new element or update existing */
	#define BPF_NOEXIST 1 /* create new element if it didn't exist */
	#define BPF_EXIST 2 /* update existing element */

	#define BPF_F_NO_PREALLOC (1U << 0)

	union bpf_attr {
	struct { /* anonymous struct used by BPF_MAP_CREATE command */
	__u32 map_type; /* one of enum bpf_map_type */
	__u32 key_size; /* size of key in bytes */
	__u32 value_size; /* size of value in bytes */
	__u32 max_entries; /* max number of entries in a map */
	__u32 map_flags; /* prealloc or not */
	};

	struct { /* anonymous struct used by BPF_MAP__ELEM commands /
	__u32 map_fd;
	__aligned_u64 key;
	union {
	__aligned_u64 value;
	__aligned_u64 next_key;
	};
	__u64 flags;
	};

	struct { /* anonymous struct used by BPF_PROG_LOAD command */
	__u32 prog_type; /* one of enum bpf_prog_type */
	__u32 insn_cnt;
	__aligned_u64 insns;
	__aligned_u64 license;
	__u32 log_level; /* verbosity level of verifier */
	__u32 log_size; /* size of user buffer */
	__aligned_u64 log_buf; /* user supplied buffer */
	__u32 kern_version; /* checked when prog_type=kprobe */
	};

	struct { /* anonymous struct used by BPF_OBJ_* commands */
	__aligned_u64 pathname;
	__u32 bpf_fd;
	};
	} __attribute__((aligned(8)));

	/* integer value in 'imm' field of BPF_CALL instruction selects which helper
	* function eBPF program intends to call
	*/
	enum bpf_func_id {
	BPF_FUNC_unspec,
	BPF_FUNC_map_lookup_elem, /* void map_lookup_elem(&map, &key) /
	BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
	BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
	BPF_FUNC_probe_read, /* int bpf_probe_read(void dst, int size, void src) */
	BPF_FUNC_ktime_get_ns, /* u64 bpf_ktime_get_ns(void) */
	BPF_FUNC_trace_printk, /* int bpf_trace_printk(const char fmt, int fmt_size, ...) /
	BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
	BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */

	/**
	* skb_store_bytes(skb, offset, from, len, flags) - store bytes into packet
	* @skb: pointer to skb
	* @offset: offset within packet from skb->mac_header
	* @from: pointer where to copy bytes from
	* @len: number of bytes to store into packet
	* @flags: bit 0 - if true, recompute skb->csum
	* other bits - reserved
	* Return: 0 on success
	*/
	BPF_FUNC_skb_store_bytes,

	/**
	* l3_csum_replace(skb, offset, from, to, flags) - recompute IP checksum
	* @skb: pointer to skb
	* @offset: offset within packet where IP checksum is located
	* @from: old value of header field
	* @to: new value of header field
	* @flags: bits 0-3 - size of header field
	* other bits - reserved
	* Return: 0 on success
	*/
	BPF_FUNC_l3_csum_replace,

	/**
	* l4_csum_replace(skb, offset, from, to, flags) - recompute TCP/UDP checksum
	* @skb: pointer to skb
	* @offset: offset within packet where TCP/UDP checksum is located
	* @from: old value of header field
	* @to: new value of header field
	* @flags: bits 0-3 - size of header field
	* bit 4 - is pseudo header
	* other bits - reserved
	* Return: 0 on success
	*/
	BPF_FUNC_l4_csum_replace,

	/**
	* bpf_tail_call(ctx, prog_array_map, index) - jump into another BPF program
	* @ctx: context pointer passed to next program
	* @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
	* @index: index inside array that selects specific program to run
	* Return: 0 on success
	*/
	BPF_FUNC_tail_call,

	/**
	* bpf_clone_redirect(skb, ifindex, flags) - redirect to another netdev
	* @skb: pointer to skb
	* @ifindex: ifindex of the net device
	* @flags: bit 0 - if set, redirect to ingress instead of egress
	* other bits - reserved
	* Return: 0 on success
	*/
	BPF_FUNC_clone_redirect,

	/**
	* u64 bpf_get_current_pid_tgid(void)
	* Return: current->tgid << 32 \| current->pid
	*/
	BPF_FUNC_get_current_pid_tgid,

	/**
	* u64 bpf_get_current_uid_gid(void)
	* Return: current_gid << 32 \| current_uid
	*/
	BPF_FUNC_get_current_uid_gid,

	/**
	* bpf_get_current_comm(char *buf, int size_of_buf)
	* stores current->comm into buf
	* Return: 0 on success
	*/
	BPF_FUNC_get_current_comm,

	/**
	* bpf_get_cgroup_classid(skb) - retrieve a proc's classid
	* @skb: pointer to skb
	* Return: classid if != 0
	*/
	BPF_FUNC_get_cgroup_classid,
	BPF_FUNC_skb_vlan_push, /* bpf_skb_vlan_push(skb, vlan_proto, vlan_tci) */
	BPF_FUNC_skb_vlan_pop, /* bpf_skb_vlan_pop(skb) */

	/**
	* bpf_skb_[gs]et_tunnel_key(skb, key, size, flags)
	* retrieve or populate tunnel metadata
	* @skb: pointer to skb
	* @key: pointer to 'struct bpf_tunnel_key'
	* @size: size of 'struct bpf_tunnel_key'
	* @flags: room for future extensions
	* Retrun: 0 on success
	*/
	BPF_FUNC_skb_get_tunnel_key,
	BPF_FUNC_skb_set_tunnel_key,
	BPF_FUNC_perf_event_read, /* u64 bpf_perf_event_read(&map, index) */
	/**
	* bpf_redirect(ifindex, flags) - redirect to another netdev
	* @ifindex: ifindex of the net device
	* @flags: bit 0 - if set, redirect to ingress instead of egress
	* other bits - reserved
	* Return: TC_ACT_REDIRECT
	*/
	BPF_FUNC_redirect,

	/**
	* bpf_get_route_realm(skb) - retrieve a dst's tclassid
	* @skb: pointer to skb
	* Return: realm if != 0
	*/
	BPF_FUNC_get_route_realm,

	/**
	* bpf_perf_event_output(ctx, map, index, data, size) - output perf raw sample
	* @ctx: struct pt_regs*
	* @map: pointer to perf_event_array map
	* @index: index of event in the map
	* @data: data on stack to be output as raw data
	* @size: size of data
	* Return: 0 on success
	*/
	BPF_FUNC_perf_event_output,
	BPF_FUNC_skb_load_bytes,

	/**
	* bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
	* @ctx: struct pt_regs*
	* @map: pointer to stack_trace map
	* @flags: bits 0-7 - numer of stack frames to skip
	* bit 8 - collect user stack instead of kernel
	* bit 9 - compare stacks by hash only
	* bit 10 - if two different stacks hash into the same stackid
	* discard old
	* other bits - reserved
	* Return: >= 0 stackid on success or negative error
	*/
	BPF_FUNC_get_stackid,

	/**
	* bpf_csum_diff(from, from_size, to, to_size, seed) - calculate csum diff
	* @from: raw from buffer
	* @from_size: length of from buffer
	* @to: raw to buffer
	* @to_size: length of to buffer
	* @seed: optional seed
	* Return: csum result
	*/
	BPF_FUNC_csum_diff,

	/**
	* bpf_skb_[gs]et_tunnel_opt(skb, opt, size)
	* retrieve or populate tunnel options metadata
	* @skb: pointer to skb
	* @opt: pointer to raw tunnel option data
	* @size: size of @opt
	* Return: 0 on success for set, option size for get
	*/
	BPF_FUNC_skb_get_tunnel_opt,
	BPF_FUNC_skb_set_tunnel_opt,

	/**
	* bpf_skb_change_proto(skb, proto, flags)
	* Change protocol of the skb. Currently supported is
	* v4 -> v6, v6 -> v4 transitions. The helper will also
	* resize the skb. eBPF program is expected to fill the
	* new headers via skb_store_bytes and lX_csum_replace.
	* @skb: pointer to skb
	* @proto: new skb->protocol type
	* @flags: reserved
	* Return: 0 on success or negative error
	*/
	BPF_FUNC_skb_change_proto,

	/**
	* bpf_skb_change_type(skb, type)
	* Change packet type of skb.
	* @skb: pointer to skb
	* @type: new skb->pkt_type type
	* Return: 0 on success or negative error
	*/
	BPF_FUNC_skb_change_type,

	/**
	* bpf_skb_under_cgroup(skb, map, index) - Check cgroup2 membership of skb
	* @skb: pointer to skb
	* @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
	* @index: index of the cgroup in the bpf_map
	* Return:
	* == 0 skb failed the cgroup2 descendant test
	* == 1 skb succeeded the cgroup2 descendant test
	* < 0 error
	*/
	BPF_FUNC_skb_under_cgroup,

	/**
	* bpf_get_hash_recalc(skb)
	* Retrieve and possibly recalculate skb->hash.
	* @skb: pointer to skb
	* Return: hash
	*/
	BPF_FUNC_get_hash_recalc,

	/**
	* u64 bpf_get_current_task(void)
	* Returns current task_struct
	* Return: current
	*/
	BPF_FUNC_get_current_task,

	/**
	* bpf_probe_write_user(void dst, void src, int len)
	* safely attempt to write to a location
	* @dst: destination address in userspace
	* @src: source address on stack
	* @len: number of bytes to copy
	* Return: 0 on success or negative error
	*/
	BPF_FUNC_probe_write_user,

	__BPF_FUNC_MAX_ID,
	};

	/* All flags used by eBPF helper functions, placed here. */

	/* BPF_FUNC_skb_store_bytes flags. */
	#define BPF_F_RECOMPUTE_CSUM (1ULL << 0)
	#define BPF_F_INVALIDATE_HASH (1ULL << 1)

	/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
	* First 4 bits are for passing the header field size.
	*/
	#define BPF_F_HDR_FIELD_MASK 0xfULL

	/* BPF_FUNC_l4_csum_replace flags. */
	#define BPF_F_PSEUDO_HDR (1ULL << 4)
	#define BPF_F_MARK_MANGLED_0 (1ULL << 5)

	/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
	#define BPF_F_INGRESS (1ULL << 0)

	/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
	#define BPF_F_TUNINFO_IPV6 (1ULL << 0)

	/* BPF_FUNC_get_stackid flags. */
	#define BPF_F_SKIP_FIELD_MASK 0xffULL
	#define BPF_F_USER_STACK (1ULL << 8)
	#define BPF_F_FAST_STACK_CMP (1ULL << 9)
	#define BPF_F_REUSE_STACKID (1ULL << 10)

	/* BPF_FUNC_skb_set_tunnel_key flags. */
	#define BPF_F_ZERO_CSUM_TX (1ULL << 1)
	#define BPF_F_DONT_FRAGMENT (1ULL << 2)

	/* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
	#define BPF_F_INDEX_MASK 0xffffffffULL
	#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
	/* BPF_FUNC_perf_event_output for sk_buff input context. */
	#define BPF_F_CTXLEN_MASK (0xfffffULL << 32)

	/* user accessible mirror of in-kernel sk_buff.
	* new fields can only be added to the end of this structure
	*/
	struct __sk_buff {
	__u32 len;
	__u32 pkt_type;
	__u32 mark;
	__u32 queue_mapping;
	__u32 protocol;
	__u32 vlan_present;
	__u32 vlan_tci;
	__u32 vlan_proto;
	__u32 priority;
	__u32 ingress_ifindex;
	__u32 ifindex;
	__u32 tc_index;
	__u32 cb[5];
	__u32 hash;
	__u32 tc_classid;
	__u32 data;
	__u32 data_end;
	};

	struct bpf_tunnel_key {
	__u32 tunnel_id;
	union {
	__u32 remote_ipv4;
	__u32 remote_ipv6[4];
	};
	__u8 tunnel_tos;
	__u8 tunnel_ttl;
	__u16 tunnel_ext;
	__u32 tunnel_label;
	};

	/* User return codes for XDP prog type.
	* A valid XDP program must return one of these defined values. All other
	* return codes are reserved for future use. Unknown return codes will result
	* in packet drop.
	*/
	enum xdp_action {
	XDP_ABORTED = 0,
	XDP_DROP,
	XDP_PASS,
	XDP_TX,
	};

	/* user accessible metadata for XDP packet hook
	* new fields must be added to the end of this structure
	*/
	struct xdp_md {
	__u32 data;
	__u32 data_end;
	};

	#endif /* _UAPI__LINUX_BPF_H__ */