Linux kernel mirror (for testing)
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linux
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, attr->flags
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 BPF_MAP_TYPE_HASH,
115 BPF_MAP_TYPE_ARRAY,
116};
117
118enum bpf_prog_type {
119 BPF_PROG_TYPE_UNSPEC,
120 BPF_PROG_TYPE_SOCKET_FILTER,
121 BPF_PROG_TYPE_KPROBE,
122 BPF_PROG_TYPE_SCHED_CLS,
123 BPF_PROG_TYPE_SCHED_ACT,
124};
125
126#define BPF_PSEUDO_MAP_FD 1
127
128/* flags for BPF_MAP_UPDATE_ELEM command */
129#define BPF_ANY 0 /* create new element or update existing */
130#define BPF_NOEXIST 1 /* create new element if it didn't exist */
131#define BPF_EXIST 2 /* update existing element */
132
133union bpf_attr {
134 struct { /* anonymous struct used by BPF_MAP_CREATE command */
135 __u32 map_type; /* one of enum bpf_map_type */
136 __u32 key_size; /* size of key in bytes */
137 __u32 value_size; /* size of value in bytes */
138 __u32 max_entries; /* max number of entries in a map */
139 };
140
141 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
142 __u32 map_fd;
143 __aligned_u64 key;
144 union {
145 __aligned_u64 value;
146 __aligned_u64 next_key;
147 };
148 __u64 flags;
149 };
150
151 struct { /* anonymous struct used by BPF_PROG_LOAD command */
152 __u32 prog_type; /* one of enum bpf_prog_type */
153 __u32 insn_cnt;
154 __aligned_u64 insns;
155 __aligned_u64 license;
156 __u32 log_level; /* verbosity level of verifier */
157 __u32 log_size; /* size of user buffer */
158 __aligned_u64 log_buf; /* user supplied buffer */
159 __u32 kern_version; /* checked when prog_type=kprobe */
160 };
161} __attribute__((aligned(8)));
162
163/* integer value in 'imm' field of BPF_CALL instruction selects which helper
164 * function eBPF program intends to call
165 */
166enum bpf_func_id {
167 BPF_FUNC_unspec,
168 BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
169 BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
170 BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
171 BPF_FUNC_probe_read, /* int bpf_probe_read(void *dst, int size, void *src) */
172 BPF_FUNC_ktime_get_ns, /* u64 bpf_ktime_get_ns(void) */
173 BPF_FUNC_trace_printk, /* int bpf_trace_printk(const char *fmt, int fmt_size, ...) */
174 BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
175 BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */
176
177 /**
178 * skb_store_bytes(skb, offset, from, len, flags) - store bytes into packet
179 * @skb: pointer to skb
180 * @offset: offset within packet from skb->mac_header
181 * @from: pointer where to copy bytes from
182 * @len: number of bytes to store into packet
183 * @flags: bit 0 - if true, recompute skb->csum
184 * other bits - reserved
185 * Return: 0 on success
186 */
187 BPF_FUNC_skb_store_bytes,
188
189 /**
190 * l3_csum_replace(skb, offset, from, to, flags) - recompute IP checksum
191 * @skb: pointer to skb
192 * @offset: offset within packet where IP checksum is located
193 * @from: old value of header field
194 * @to: new value of header field
195 * @flags: bits 0-3 - size of header field
196 * other bits - reserved
197 * Return: 0 on success
198 */
199 BPF_FUNC_l3_csum_replace,
200
201 /**
202 * l4_csum_replace(skb, offset, from, to, flags) - recompute TCP/UDP checksum
203 * @skb: pointer to skb
204 * @offset: offset within packet where TCP/UDP checksum is located
205 * @from: old value of header field
206 * @to: new value of header field
207 * @flags: bits 0-3 - size of header field
208 * bit 4 - is pseudo header
209 * other bits - reserved
210 * Return: 0 on success
211 */
212 BPF_FUNC_l4_csum_replace,
213 __BPF_FUNC_MAX_ID,
214};
215
216/* user accessible mirror of in-kernel sk_buff.
217 * new fields can only be added to the end of this structure
218 */
219struct __sk_buff {
220 __u32 len;
221 __u32 pkt_type;
222 __u32 mark;
223 __u32 queue_mapping;
224 __u32 protocol;
225 __u32 vlan_present;
226 __u32 vlan_tci;
227 __u32 vlan_proto;
228 __u32 priority;
229};
230
231#endif /* _UAPI__LINUX_BPF_H__ */