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
54 struct 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
59 struct 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
247 int bpf_parse_common(enum bpf_prog_type type, struct bpf_cfg_in *cfg,
248 const struct bpf_cfg_ops *ops, void *nl);
249
250 const char *bpf_prog_to_default_section(enum bpf_prog_type type);
251
252 int bpf_graft_map(const char *map_path, uint32_t *key, int argc, char **argv);
253 int bpf_trace_pipe(void);
254
255 void bpf_print_ops(FILE *f, struct rtattr *bpf_ops, __u16 len);
256
257 int 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
261 int bpf_prog_attach_fd(int prog_fd, int target_fd, enum bpf_attach_type type);
262 int bpf_prog_detach_fd(int target_fd, enum bpf_attach_type type);
263
264 int bpf_dump_prog_info(FILE *f, uint32_t id);
265
266 #ifdef HAVE_ELF
267 int bpf_send_map_fds(const char *path, const char *obj);
268 int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux,
269 unsigned int entries);
270 #else
bpf_send_map_fds(const char * path,const char * obj)271 static inline int bpf_send_map_fds(const char *path, const char *obj)
272 {
273 return 0;
274 }
275
bpf_recv_map_fds(const char * path,int * fds,struct bpf_map_aux * aux,unsigned int entries)276 static 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