/* 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,
  };
  
  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,
  };
  
  #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 */
  
  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 */
  	};
  
  	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_MAX_ID,
  };
  
  /* 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;
  };
  
  struct bpf_tunnel_key {
  	__u32 tunnel_id;
  	__u32 remote_ipv4;
  };
  
  #endif /* _UAPI__LINUX_BPF_H__ */