1#ifndef __BPF_API__
2#define __BPF_API__
3
4/* Note:
5 *
6 * This file can be included into eBPF kernel programs. It contains
7 * a couple of useful helper functions, map/section ABI (bpf_elf.h),
8 * misc macros and some eBPF specific LLVM built-ins.
9 */
10
11#include <stdint.h>
12
13#include <linux/pkt_cls.h>
14#include <linux/bpf.h>
15#include <linux/filter.h>
16
17#include <asm/byteorder.h>
18
19#include "bpf_elf.h"
20
21/** Misc macros. */
22
23#ifndef __stringify
24# define __stringify(X)		#X
25#endif
26
27#ifndef __maybe_unused
28# define __maybe_unused		__attribute__((__unused__))
29#endif
30
31#ifndef offsetof
32# define offsetof(TYPE, MEMBER)	__builtin_offsetof(TYPE, MEMBER)
33#endif
34
35#ifndef likely
36# define likely(X)		__builtin_expect(!!(X), 1)
37#endif
38
39#ifndef unlikely
40# define unlikely(X)		__builtin_expect(!!(X), 0)
41#endif
42
43#ifndef htons
44# define htons(X)		__constant_htons((X))
45#endif
46
47#ifndef ntohs
48# define ntohs(X)		__constant_ntohs((X))
49#endif
50
51#ifndef htonl
52# define htonl(X)		__constant_htonl((X))
53#endif
54
55#ifndef ntohl
56# define ntohl(X)		__constant_ntohl((X))
57#endif
58
59/** Section helper macros. */
60
61#ifndef __section
62# define __section(NAME)						\
63	__attribute__((section(NAME), used))
64#endif
65
66#ifndef __section_tail
67# define __section_tail(ID, KEY)					\
68	__section(__stringify(ID) "/" __stringify(KEY))
69#endif
70
71#ifndef __section_cls_entry
72# define __section_cls_entry						\
73	__section(ELF_SECTION_CLASSIFIER)
74#endif
75
76#ifndef __section_act_entry
77# define __section_act_entry						\
78	__section(ELF_SECTION_ACTION)
79#endif
80
81#ifndef __section_license
82# define __section_license						\
83	__section(ELF_SECTION_LICENSE)
84#endif
85
86#ifndef __section_maps
87# define __section_maps							\
88	__section(ELF_SECTION_MAPS)
89#endif
90
91/** Declaration helper macros. */
92
93#ifndef BPF_LICENSE
94# define BPF_LICENSE(NAME)						\
95	char ____license[] __section_license = NAME
96#endif
97
98#ifndef __BPF_MAP
99# define __BPF_MAP(NAME, TYPE, ID, SIZE_KEY, SIZE_VALUE, PIN, MAX_ELEM)	\
100	struct bpf_elf_map __section_maps NAME = {			\
101		.type		= (TYPE),				\
102		.id		= (ID),					\
103		.size_key	= (SIZE_KEY),				\
104		.size_value	= (SIZE_VALUE),				\
105		.pinning	= (PIN),				\
106		.max_elem	= (MAX_ELEM),				\
107	}
108#endif
109
110#ifndef BPF_HASH
111# define BPF_HASH(NAME, ID, SIZE_KEY, SIZE_VALUE, PIN, MAX_ELEM)	\
112	__BPF_MAP(NAME, BPF_MAP_TYPE_HASH, ID, SIZE_KEY, SIZE_VALUE,	\
113		  PIN, MAX_ELEM)
114#endif
115
116#ifndef BPF_ARRAY
117# define BPF_ARRAY(NAME, ID, SIZE_VALUE, PIN, MAX_ELEM)			\
118	__BPF_MAP(NAME, BPF_MAP_TYPE_ARRAY, ID, sizeof(uint32_t), 	\
119		  SIZE_VALUE, PIN, MAX_ELEM)
120#endif
121
122#ifndef BPF_ARRAY2
123# define BPF_ARRAY2(NAME, ID, PIN, MAX_ELEM)				\
124	BPF_ARRAY(NAME, ID, sizeof(uint16_t), PIN, MAX_ELEM)
125#endif
126
127#ifndef BPF_ARRAY4
128# define BPF_ARRAY4(NAME, ID, PIN, MAX_ELEM)				\
129	BPF_ARRAY(NAME, ID, sizeof(uint32_t), PIN, MAX_ELEM)
130#endif
131
132#ifndef BPF_ARRAY8
133# define BPF_ARRAY8(NAME, ID, PIN, MAX_ELEM)				\
134	BPF_ARRAY(NAME, ID, sizeof(uint64_t), PIN, MAX_ELEM)
135#endif
136
137#ifndef BPF_PROG_ARRAY
138# define BPF_PROG_ARRAY(NAME, ID, PIN, MAX_ELEM)			\
139	__BPF_MAP(NAME, BPF_MAP_TYPE_PROG_ARRAY, ID, sizeof(uint32_t),	\
140		  sizeof(uint32_t), PIN, MAX_ELEM)
141#endif
142
143/** Classifier helper */
144
145#ifndef BPF_H_DEFAULT
146# define BPF_H_DEFAULT	-1
147#endif
148
149/** BPF helper functions for tc. */
150
151#ifndef BPF_FUNC
152# define BPF_FUNC(NAME, ...)						\
153	(* NAME)(__VA_ARGS__) __maybe_unused = (void *) BPF_FUNC_##NAME
154#endif
155
156/* Map access/manipulation */
157static void *BPF_FUNC(map_lookup_elem, void *map, const void *key);
158static int BPF_FUNC(map_update_elem, void *map, const void *key,
159		    const void *value, uint32_t flags);
160static int BPF_FUNC(map_delete_elem, void *map, const void *key);
161
162/* Time access */
163static uint64_t BPF_FUNC(ktime_get_ns);
164
165/* Debugging */
166static void BPF_FUNC(trace_printk, const char *fmt, int fmt_size, ...);
167
168/* Random numbers */
169static uint32_t BPF_FUNC(get_prandom_u32);
170
171/* Tail calls */
172static void BPF_FUNC(tail_call, struct __sk_buff *skb, void *map,
173		     uint32_t index);
174
175/* System helpers */
176static uint32_t BPF_FUNC(get_smp_processor_id);
177
178/* Packet misc meta data */
179static uint32_t BPF_FUNC(get_cgroup_classid, struct __sk_buff *skb);
180static uint32_t BPF_FUNC(get_route_realm, struct __sk_buff *skb);
181
182/* Packet redirection */
183static int BPF_FUNC(redirect, int ifindex, uint32_t flags);
184static int BPF_FUNC(clone_redirect, struct __sk_buff *skb, int ifindex,
185		    uint32_t flags);
186
187/* Packet manipulation */
188#define BPF_PSEUDO_HDR			0x10
189#define BPF_HAS_PSEUDO_HDR(flags)	((flags) & BPF_PSEUDO_HDR)
190#define BPF_HDR_FIELD_SIZE(flags)	((flags) & 0x0f)
191
192static int BPF_FUNC(skb_store_bytes, struct __sk_buff *skb, uint32_t off,
193		    void *from, uint32_t len, uint32_t flags);
194static int BPF_FUNC(l3_csum_replace, struct __sk_buff *skb, uint32_t off,
195		    uint32_t from, uint32_t to, uint32_t flags);
196static int BPF_FUNC(l4_csum_replace, struct __sk_buff *skb, uint32_t off,
197		    uint32_t from, uint32_t to, uint32_t flags);
198
199/* Packet vlan encap/decap */
200static int BPF_FUNC(skb_vlan_push, struct __sk_buff *skb, uint16_t proto,
201		    uint16_t vlan_tci);
202static int BPF_FUNC(skb_vlan_pop, struct __sk_buff *skb);
203
204/* Packet tunnel encap/decap */
205static int BPF_FUNC(skb_get_tunnel_key, struct __sk_buff *skb,
206		    struct bpf_tunnel_key *to, uint32_t size, uint32_t flags);
207static int BPF_FUNC(skb_set_tunnel_key, struct __sk_buff *skb,
208		    struct bpf_tunnel_key *from, uint32_t size, uint32_t flags);
209
210/** LLVM built-ins */
211
212#ifndef lock_xadd
213# define lock_xadd(ptr, val)	((void) __sync_fetch_and_add(ptr, val))
214#endif
215
216unsigned long long load_byte(void *skb, unsigned long long off)
217	asm ("llvm.bpf.load.byte");
218
219unsigned long long load_half(void *skb, unsigned long long off)
220	asm ("llvm.bpf.load.half");
221
222unsigned long long load_word(void *skb, unsigned long long off)
223	asm ("llvm.bpf.load.word");
224
225#endif /* __BPF_API__ */
226