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 */
40enum {
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
58struct 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 */
67enum 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
112enum bpf_map_type {
113	BPF_MAP_TYPE_UNSPEC,
114};
115
116enum bpf_prog_type {
117	BPF_PROG_TYPE_UNSPEC,
118};
119
120union 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 */
151enum bpf_func_id {
152	BPF_FUNC_unspec,
153	__BPF_FUNC_MAX_ID,
154};
155
156#endif /* _UAPI__LINUX_BPF_H__ */
157