1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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.
7 #ifndef _UAPI__LINUX_BPF_H__
8 #define _UAPI__LINUX_BPF_H__
10 #include <linux/types.h>
11 #include <linux/bpf_common.h>
13 /* Extended instruction set based on top of classic BPF */
15 /* instruction classes */
16 #define BPF_ALU64 0x07 /* alu mode in double word width */
19 #define BPF_DW 0x18 /* double word */
20 #define BPF_XADD 0xc0 /* exclusive add */
23 #define BPF_MOV 0xb0 /* mov reg to reg */
24 #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
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
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 */
39 /* Register numbers */
55 /* BPF has 10 general purpose 64-bit registers and stack frame. */
56 #define MAX_BPF_REG __MAX_BPF_REG
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 */
66 /* BPF syscall commands */
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
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
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, attr->flags
86 * returns zero or negative error
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
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
102 BPF_MAP_GET_NEXT_KEY,
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
119 BPF_PROG_TYPE_UNSPEC,
120 BPF_PROG_TYPE_SOCKET_FILTER,
123 /* flags for BPF_MAP_UPDATE_ELEM command */
124 #define BPF_ANY 0 /* create new element or update existing */
125 #define BPF_NOEXIST 1 /* create new element if it didn't exist */
126 #define BPF_EXIST 2 /* update existing element */
129 struct { /* anonymous struct used by BPF_MAP_CREATE command */
130 __u32 map_type; /* one of enum bpf_map_type */
131 __u32 key_size; /* size of key in bytes */
132 __u32 value_size; /* size of value in bytes */
133 __u32 max_entries; /* max number of entries in a map */
136 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
141 __aligned_u64 next_key;
146 struct { /* anonymous struct used by BPF_PROG_LOAD command */
147 __u32 prog_type; /* one of enum bpf_prog_type */
150 __aligned_u64 license;
151 __u32 log_level; /* verbosity level of verifier */
152 __u32 log_size; /* size of user buffer */
153 __aligned_u64 log_buf; /* user supplied buffer */
155 } __attribute__((aligned(8)));
157 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
158 * function eBPF program intends to call
162 BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
163 BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
164 BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
168 #endif /* _UAPI__LINUX_BPF_H__ */