1/*
2 * bpf_util.h	BPF common code
3 *
4 *		This program is free software; you can distribute it and/or
5 *		modify it under the terms of the GNU General Public License
6 *		as published by the Free Software Foundation; either version
7 *		2 of the License, or (at your option) any later version.
8 *
9 * Authors:	Daniel Borkmann <daniel@iogearbox.net>
10 *		Jiri Pirko <jiri@resnulli.us>
11 */
12
13#ifndef __BPF_UTIL__
14#define __BPF_UTIL__
15
16#include <linux/bpf.h>
17#include <linux/filter.h>
18#include <linux/magic.h>
19#include <linux/elf-em.h>
20#include <linux/if_alg.h>
21
22#include "utils.h"
23#include "bpf_scm.h"
24
25#define BPF_ENV_UDS	"TC_BPF_UDS"
26#define BPF_ENV_MNT	"TC_BPF_MNT"
27
28#ifndef BPF_MAX_LOG
29# define BPF_MAX_LOG	4096
30#endif
31
32#define BPF_DIR_GLOBALS	"globals"
33
34#ifndef BPF_FS_MAGIC
35# define BPF_FS_MAGIC	0xcafe4a11
36#endif
37
38#define BPF_DIR_MNT	"/sys/fs/bpf"
39
40#ifndef TRACEFS_MAGIC
41# define TRACEFS_MAGIC	0x74726163
42#endif
43
44#define TRACE_DIR_MNT	"/sys/kernel/tracing"
45
46#ifndef AF_ALG
47# define AF_ALG		38
48#endif
49
50#ifndef EM_BPF
51# define EM_BPF		247
52#endif
53
54struct bpf_cfg_ops {
55	void (*cbpf_cb)(void *nl, const struct sock_filter *ops, int ops_len);
56	void (*ebpf_cb)(void *nl, int fd, const char *annotation);
57};
58
59struct bpf_cfg_in {
60	const char *object;
61	const char *section;
62	const char *uds;
63	int argc;
64	char **argv;
65	struct sock_filter *ops;
66};
67
68/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
69
70#define BPF_ALU64_REG(OP, DST, SRC)				\
71	((struct bpf_insn) {					\
72		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
73		.dst_reg = DST,					\
74		.src_reg = SRC,					\
75		.off   = 0,					\
76		.imm   = 0 })
77
78#define BPF_ALU32_REG(OP, DST, SRC)				\
79	((struct bpf_insn) {					\
80		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
81		.dst_reg = DST,					\
82		.src_reg = SRC,					\
83		.off   = 0,					\
84		.imm   = 0 })
85
86/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
87
88#define BPF_ALU64_IMM(OP, DST, IMM)				\
89	((struct bpf_insn) {					\
90		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
91		.dst_reg = DST,					\
92		.src_reg = 0,					\
93		.off   = 0,					\
94		.imm   = IMM })
95
96#define BPF_ALU32_IMM(OP, DST, IMM)				\
97	((struct bpf_insn) {					\
98		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
99		.dst_reg = DST,					\
100		.src_reg = 0,					\
101		.off   = 0,					\
102		.imm   = IMM })
103
104/* Short form of mov, dst_reg = src_reg */
105
106#define BPF_MOV64_REG(DST, SRC)					\
107	((struct bpf_insn) {					\
108		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
109		.dst_reg = DST,					\
110		.src_reg = SRC,					\
111		.off   = 0,					\
112		.imm   = 0 })
113
114#define BPF_MOV32_REG(DST, SRC)					\
115	((struct bpf_insn) {					\
116		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
117		.dst_reg = DST,					\
118		.src_reg = SRC,					\
119		.off   = 0,					\
120		.imm   = 0 })
121
122/* Short form of mov, dst_reg = imm32 */
123
124#define BPF_MOV64_IMM(DST, IMM)					\
125	((struct bpf_insn) {					\
126		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
127		.dst_reg = DST,					\
128		.src_reg = 0,					\
129		.off   = 0,					\
130		.imm   = IMM })
131
132#define BPF_MOV32_IMM(DST, IMM)					\
133	((struct bpf_insn) {					\
134		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
135		.dst_reg = DST,					\
136		.src_reg = 0,					\
137		.off   = 0,					\
138		.imm   = IMM })
139
140/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
141#define BPF_LD_IMM64(DST, IMM)					\
142	BPF_LD_IMM64_RAW(DST, 0, IMM)
143
144#define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
145	((struct bpf_insn) {					\
146		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
147		.dst_reg = DST,					\
148		.src_reg = SRC,					\
149		.off   = 0,					\
150		.imm   = (__u32) (IMM) }),			\
151	((struct bpf_insn) {					\
152		.code  = 0, /* zero is reserved opcode */	\
153		.dst_reg = 0,					\
154		.src_reg = 0,					\
155		.off   = 0,					\
156		.imm   = ((__u64) (IMM)) >> 32 })
157
158#ifndef BPF_PSEUDO_MAP_FD
159# define BPF_PSEUDO_MAP_FD	1
160#endif
161
162/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
163#define BPF_LD_MAP_FD(DST, MAP_FD)				\
164	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
165
166
167/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
168
169#define BPF_LD_ABS(SIZE, IMM)					\
170	((struct bpf_insn) {					\
171		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
172		.dst_reg = 0,					\
173		.src_reg = 0,					\
174		.off   = 0,					\
175		.imm   = IMM })
176
177/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
178
179#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
180	((struct bpf_insn) {					\
181		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
182		.dst_reg = DST,					\
183		.src_reg = SRC,					\
184		.off   = OFF,					\
185		.imm   = 0 })
186
187/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
188
189#define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
190	((struct bpf_insn) {					\
191		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
192		.dst_reg = DST,					\
193		.src_reg = SRC,					\
194		.off   = OFF,					\
195		.imm   = 0 })
196
197/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
198
199#define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
200	((struct bpf_insn) {					\
201		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
202		.dst_reg = DST,					\
203		.src_reg = 0,					\
204		.off   = OFF,					\
205		.imm   = IMM })
206
207/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
208
209#define BPF_JMP_REG(OP, DST, SRC, OFF)				\
210	((struct bpf_insn) {					\
211		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
212		.dst_reg = DST,					\
213		.src_reg = SRC,					\
214		.off   = OFF,					\
215		.imm   = 0 })
216
217/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
218
219#define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
220	((struct bpf_insn) {					\
221		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
222		.dst_reg = DST,					\
223		.src_reg = 0,					\
224		.off   = OFF,					\
225		.imm   = IMM })
226
227/* Raw code statement block */
228
229#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
230	((struct bpf_insn) {					\
231		.code  = CODE,					\
232		.dst_reg = DST,					\
233		.src_reg = SRC,					\
234		.off   = OFF,					\
235		.imm   = IMM })
236
237/* Program exit */
238
239#define BPF_EXIT_INSN()						\
240	((struct bpf_insn) {					\
241		.code  = BPF_JMP | BPF_EXIT,			\
242		.dst_reg = 0,					\
243		.src_reg = 0,					\
244		.off   = 0,					\
245		.imm   = 0 })
246
247int bpf_parse_common(enum bpf_prog_type type, struct bpf_cfg_in *cfg,
248		     const struct bpf_cfg_ops *ops, void *nl);
249
250const char *bpf_prog_to_default_section(enum bpf_prog_type type);
251
252int bpf_graft_map(const char *map_path, uint32_t *key, int argc, char **argv);
253int bpf_trace_pipe(void);
254
255void bpf_print_ops(FILE *f, struct rtattr *bpf_ops, __u16 len);
256
257int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns,
258		  size_t size_insns, const char *license, char *log,
259		  size_t size_log);
260
261int bpf_prog_attach_fd(int prog_fd, int target_fd, enum bpf_attach_type type);
262int bpf_prog_detach_fd(int target_fd, enum bpf_attach_type type);
263
264int bpf_dump_prog_info(FILE *f, uint32_t id);
265
266#ifdef HAVE_ELF
267int bpf_send_map_fds(const char *path, const char *obj);
268int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux,
269		     unsigned int entries);
270#else
271static inline int bpf_send_map_fds(const char *path, const char *obj)
272{
273	return 0;
274}
275
276static inline int bpf_recv_map_fds(const char *path, int *fds,
277				   struct bpf_map_aux *aux,
278				   unsigned int entries)
279{
280	return -1;
281}
282#endif /* HAVE_ELF */
283#endif /* __BPF_UTIL__ */
284