summaryrefslogtreecommitdiffstats
path: root/include/bpf_api.h
blob: 82c47089f61492b3c66bc531de2e0b31cfd51da3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BPF_API__
#define __BPF_API__

/* Note:
 *
 * This file can be included into eBPF kernel programs. It contains
 * a couple of useful helper functions, map/section ABI (bpf_elf.h),
 * misc macros and some eBPF specific LLVM built-ins.
 */

#include <stdint.h>

#include <linux/pkt_cls.h>
#include <linux/bpf.h>
#include <linux/filter.h>

#include <asm/byteorder.h>

#include "bpf_elf.h"

/** libbpf pin type. */
enum libbpf_pin_type {
	LIBBPF_PIN_NONE,
	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
	LIBBPF_PIN_BY_NAME,
};

/** Type helper macros. */

#define __uint(name, val) int (*name)[val]
#define __type(name, val) typeof(val) *name
#define __array(name, val) typeof(val) *name[]

/** Misc macros. */

#ifndef __stringify
# define __stringify(X)		#X
#endif

#ifndef __maybe_unused
# define __maybe_unused		__attribute__((__unused__))
#endif

#ifndef offsetof
# define offsetof(TYPE, MEMBER)	__builtin_offsetof(TYPE, MEMBER)
#endif

#ifndef likely
# define likely(X)		__builtin_expect(!!(X), 1)
#endif

#ifndef unlikely
# define unlikely(X)		__builtin_expect(!!(X), 0)
#endif

#ifndef htons
# define htons(X)		__constant_htons((X))
#endif

#ifndef ntohs
# define ntohs(X)		__constant_ntohs((X))
#endif

#ifndef htonl
# define htonl(X)		__constant_htonl((X))
#endif

#ifndef ntohl
# define ntohl(X)		__constant_ntohl((X))
#endif

#ifndef __inline__
# define __inline__		__attribute__((always_inline))
#endif

/** Section helper macros. */

#ifndef __section
# define __section(NAME)						\
	__attribute__((section(NAME), used))
#endif

#ifndef __section_tail
# define __section_tail(ID, KEY)					\
	__section(__stringify(ID) "/" __stringify(KEY))
#endif

#ifndef __section_xdp_entry
# define __section_xdp_entry						\
	__section(ELF_SECTION_PROG)
#endif

#ifndef __section_cls_entry
# define __section_cls_entry						\
	__section(ELF_SECTION_CLASSIFIER)
#endif

#ifndef __section_act_entry
# define __section_act_entry						\
	__section(ELF_SECTION_ACTION)
#endif

#ifndef __section_lwt_entry
# define __section_lwt_entry						\
	__section(ELF_SECTION_PROG)
#endif

#ifndef __section_license
# define __section_license						\
	__section(ELF_SECTION_LICENSE)
#endif

#ifndef __section_maps
# define __section_maps							\
	__section(ELF_SECTION_MAPS)
#endif

/** Declaration helper macros. */

#ifndef BPF_LICENSE
# define BPF_LICENSE(NAME)						\
	char ____license[] __section_license = NAME
#endif

/** Classifier helper */

#ifndef BPF_H_DEFAULT
# define BPF_H_DEFAULT	-1
#endif

/** BPF helper functions for tc. Individual flags are in linux/bpf.h */

#ifndef __BPF_FUNC
# define __BPF_FUNC(NAME, ...)						\
	(* NAME)(__VA_ARGS__) __maybe_unused
#endif

#ifndef BPF_FUNC
# define BPF_FUNC(NAME, ...)						\
	__BPF_FUNC(NAME, __VA_ARGS__) = (void *) BPF_FUNC_##NAME
#endif

/* Map access/manipulation */
static void *BPF_FUNC(map_lookup_elem, void *map, const void *key);
static int BPF_FUNC(map_update_elem, void *map, const void *key,
		    const void *value, uint32_t flags);
static int BPF_FUNC(map_delete_elem, void *map, const void *key);

/* Time access */
static uint64_t BPF_FUNC(ktime_get_ns);

/* Debugging */

/* FIXME: __attribute__ ((format(printf, 1, 3))) not possible unless
 * llvm bug https://llvm.org/bugs/show_bug.cgi?id=26243 gets resolved.
 * It would require ____fmt to be made const, which generates a reloc
 * entry (non-map).
 */
static void BPF_FUNC(trace_printk, const char *fmt, int fmt_size, ...);

#ifndef printt
# define printt(fmt, ...)						\
	({								\
		char ____fmt[] = fmt;					\
		trace_printk(____fmt, sizeof(____fmt), ##__VA_ARGS__);	\
	})
#endif

/* Random numbers */
static uint32_t BPF_FUNC(get_prandom_u32);

/* Tail calls */
static void BPF_FUNC(tail_call, struct __sk_buff *skb, void *map,
		     uint32_t index);

/* System helpers */
static uint32_t BPF_FUNC(get_smp_processor_id);
static uint32_t BPF_FUNC(get_numa_node_id);

/* Packet misc meta data */
static uint32_t BPF_FUNC(get_cgroup_classid, struct __sk_buff *skb);
static int BPF_FUNC(skb_under_cgroup, void *map, uint32_t index);

static uint32_t BPF_FUNC(get_route_realm, struct __sk_buff *skb);
static uint32_t BPF_FUNC(get_hash_recalc, struct __sk_buff *skb);
static uint32_t BPF_FUNC(set_hash_invalid, struct __sk_buff *skb);

/* Packet redirection */
static int BPF_FUNC(redirect, int ifindex, uint32_t flags);
static int BPF_FUNC(clone_redirect, struct __sk_buff *skb, int ifindex,
		    uint32_t flags);

/* Packet manipulation */
static int BPF_FUNC(skb_load_bytes, struct __sk_buff *skb, uint32_t off,
		    void *to, uint32_t len);
static int BPF_FUNC(skb_store_bytes, struct __sk_buff *skb, uint32_t off,
		    const void *from, uint32_t len, uint32_t flags);

static int BPF_FUNC(l3_csum_replace, struct __sk_buff *skb, uint32_t off,
		    uint32_t from, uint32_t to, uint32_t flags);
static int BPF_FUNC(l4_csum_replace, struct __sk_buff *skb, uint32_t off,
		    uint32_t from, uint32_t to, uint32_t flags);
static int BPF_FUNC(csum_diff, const void *from, uint32_t from_size,
		    const void *to, uint32_t to_size, uint32_t seed);
static int BPF_FUNC(csum_update, struct __sk_buff *skb, uint32_t wsum);

static int BPF_FUNC(skb_change_type, struct __sk_buff *skb, uint32_t type);
static int BPF_FUNC(skb_change_proto, struct __sk_buff *skb, uint32_t proto,
		    uint32_t flags);
static int BPF_FUNC(skb_change_tail, struct __sk_buff *skb, uint32_t nlen,
		    uint32_t flags);

static int BPF_FUNC(skb_pull_data, struct __sk_buff *skb, uint32_t len);

/* Event notification */
static int __BPF_FUNC(skb_event_output, struct __sk_buff *skb, void *map,
		      uint64_t index, const void *data, uint32_t size) =
		      (void *) BPF_FUNC_perf_event_output;

/* Packet vlan encap/decap */
static int BPF_FUNC(skb_vlan_push, struct __sk_buff *skb, uint16_t proto,
		    uint16_t vlan_tci);
static int BPF_FUNC(skb_vlan_pop, struct __sk_buff *skb);

/* Packet tunnel encap/decap */
static int BPF_FUNC(skb_get_tunnel_key, struct __sk_buff *skb,
		    struct bpf_tunnel_key *to, uint32_t size, uint32_t flags);
static int BPF_FUNC(skb_set_tunnel_key, struct __sk_buff *skb,
		    const struct bpf_tunnel_key *from, uint32_t size,
		    uint32_t flags);

static int BPF_FUNC(skb_get_tunnel_opt, struct __sk_buff *skb,
		    void *to, uint32_t size);
static int BPF_FUNC(skb_set_tunnel_opt, struct __sk_buff *skb,
		    const void *from, uint32_t size);

/** LLVM built-ins, mem*() routines work for constant size */

#ifndef lock_xadd
# define lock_xadd(ptr, val)	((void) __sync_fetch_and_add(ptr, val))
#endif

#ifndef memset
# define memset(s, c, n)	__builtin_memset((s), (c), (n))
#endif

#ifndef memcpy
# define memcpy(d, s, n)	__builtin_memcpy((d), (s), (n))
#endif

#ifndef memmove
# define memmove(d, s, n)	__builtin_memmove((d), (s), (n))
#endif

/* FIXME: __builtin_memcmp() is not yet fully useable unless llvm bug
 * https://llvm.org/bugs/show_bug.cgi?id=26218 gets resolved. Also
 * this one would generate a reloc entry (non-map), otherwise.
 */
#if 0
#ifndef memcmp
# define memcmp(a, b, n)	__builtin_memcmp((a), (b), (n))
#endif
#endif

unsigned long long load_byte(void *skb, unsigned long long off)
	asm ("llvm.bpf.load.byte");

unsigned long long load_half(void *skb, unsigned long long off)
	asm ("llvm.bpf.load.half");

unsigned long long load_word(void *skb, unsigned long long off)
	asm ("llvm.bpf.load.word");

#endif /* __BPF_API__ */