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      1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
      2  *
      3  * This program is free software; you can redistribute it and/or
      4  * modify it under the terms of version 2 of the GNU General Public
      5  * License as published by the Free Software Foundation.
      6  */
      7 #ifndef _UAPI__LINUX_BPF_H__
      8 #define _UAPI__LINUX_BPF_H__
      9 
     10 #include <linux/types.h>
     11 #include <linux/bpf_common.h>
     12 
     13 /* Extended instruction set based on top of classic BPF */
     14 
     15 /* instruction classes */
     16 #define BPF_ALU64	0x07	/* alu mode in double word width */
     17 
     18 /* ld/ldx fields */
     19 #define BPF_DW		0x18	/* double word */
     20 #define BPF_XADD	0xc0	/* exclusive add */
     21 
     22 /* alu/jmp fields */
     23 #define BPF_MOV		0xb0	/* mov reg to reg */
     24 #define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */
     25 
     26 /* change endianness of a register */
     27 #define BPF_END		0xd0	/* flags for endianness conversion: */
     28 #define BPF_TO_LE	0x00	/* convert to little-endian */
     29 #define BPF_TO_BE	0x08	/* convert to big-endian */
     30 #define BPF_FROM_LE	BPF_TO_LE
     31 #define BPF_FROM_BE	BPF_TO_BE
     32 
     33 #define BPF_JNE		0x50	/* jump != */
     34 #define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
     35 #define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
     36 #define BPF_CALL	0x80	/* function call */
     37 #define BPF_EXIT	0x90	/* function return */
     38 
     39 /* Register numbers */
     40 enum {
     41 	BPF_REG_0 = 0,
     42 	BPF_REG_1,
     43 	BPF_REG_2,
     44 	BPF_REG_3,
     45 	BPF_REG_4,
     46 	BPF_REG_5,
     47 	BPF_REG_6,
     48 	BPF_REG_7,
     49 	BPF_REG_8,
     50 	BPF_REG_9,
     51 	BPF_REG_10,
     52 	__MAX_BPF_REG,
     53 };
     54 
     55 /* BPF has 10 general purpose 64-bit registers and stack frame. */
     56 #define MAX_BPF_REG	__MAX_BPF_REG
     57 
     58 struct bpf_insn {
     59 	__u8	code;		/* opcode */
     60 	__u8	dst_reg:4;	/* dest register */
     61 	__u8	src_reg:4;	/* source register */
     62 	__s16	off;		/* signed offset */
     63 	__s32	imm;		/* signed immediate constant */
     64 };
     65 
     66 /* BPF syscall commands */
     67 enum bpf_cmd {
     68 	/* create a map with given type and attributes
     69 	 * fd = bpf(BPF_MAP_CREATE, union bpf_attr *, u32 size)
     70 	 * returns fd or negative error
     71 	 * map is deleted when fd is closed
     72 	 */
     73 	BPF_MAP_CREATE,
     74 
     75 	/* lookup key in a given map
     76 	 * err = bpf(BPF_MAP_LOOKUP_ELEM, union bpf_attr *attr, u32 size)
     77 	 * Using attr->map_fd, attr->key, attr->value
     78 	 * returns zero and stores found elem into value
     79 	 * or negative error
     80 	 */
     81 	BPF_MAP_LOOKUP_ELEM,
     82 
     83 	/* create or update key/value pair in a given map
     84 	 * err = bpf(BPF_MAP_UPDATE_ELEM, union bpf_attr *attr, u32 size)
     85 	 * Using attr->map_fd, attr->key, attr->value
     86 	 * returns zero or negative error
     87 	 */
     88 	BPF_MAP_UPDATE_ELEM,
     89 
     90 	/* find and delete elem by key in a given map
     91 	 * err = bpf(BPF_MAP_DELETE_ELEM, union bpf_attr *attr, u32 size)
     92 	 * Using attr->map_fd, attr->key
     93 	 * returns zero or negative error
     94 	 */
     95 	BPF_MAP_DELETE_ELEM,
     96 
     97 	/* lookup key in a given map and return next key
     98 	 * err = bpf(BPF_MAP_GET_NEXT_KEY, union bpf_attr *attr, u32 size)
     99 	 * Using attr->map_fd, attr->key, attr->next_key
    100 	 * returns zero and stores next key or negative error
    101 	 */
    102 	BPF_MAP_GET_NEXT_KEY,
    103 
    104 	/* verify and load eBPF program
    105 	 * prog_fd = bpf(BPF_PROG_LOAD, union bpf_attr *attr, u32 size)
    106 	 * Using attr->prog_type, attr->insns, attr->license
    107 	 * returns fd or negative error
    108 	 */
    109 	BPF_PROG_LOAD,
    110 };
    111 
    112 enum bpf_map_type {
    113 	BPF_MAP_TYPE_UNSPEC,
    114 };
    115 
    116 enum bpf_prog_type {
    117 	BPF_PROG_TYPE_UNSPEC,
    118 };
    119 
    120 union bpf_attr {
    121 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
    122 		__u32	map_type;	/* one of enum bpf_map_type */
    123 		__u32	key_size;	/* size of key in bytes */
    124 		__u32	value_size;	/* size of value in bytes */
    125 		__u32	max_entries;	/* max number of entries in a map */
    126 	};
    127 
    128 	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
    129 		__u32		map_fd;
    130 		__aligned_u64	key;
    131 		union {
    132 			__aligned_u64 value;
    133 			__aligned_u64 next_key;
    134 		};
    135 	};
    136 
    137 	struct { /* anonymous struct used by BPF_PROG_LOAD command */
    138 		__u32		prog_type;	/* one of enum bpf_prog_type */
    139 		__u32		insn_cnt;
    140 		__aligned_u64	insns;
    141 		__aligned_u64	license;
    142 		__u32		log_level;	/* verbosity level of verifier */
    143 		__u32		log_size;	/* size of user buffer */
    144 		__aligned_u64	log_buf;	/* user supplied buffer */
    145 	};
    146 } __attribute__((aligned(8)));
    147 
    148 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
    149  * function eBPF program intends to call
    150  */
    151 enum bpf_func_id {
    152 	BPF_FUNC_unspec,
    153 	__BPF_FUNC_MAX_ID,
    154 };
    155 
    156 #endif /* _UAPI__LINUX_BPF_H__ */
    157