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bpf: provide helper that indicates eBPF was migrated
[deliverable/linux.git] / include / linux / filter.h
1 /*
2 * Linux Socket Filter Data Structures
3 */
4 #ifndef __LINUX_FILTER_H__
5 #define __LINUX_FILTER_H__
6
7 #include <stdarg.h>
8
9 #include <linux/atomic.h>
10 #include <linux/compat.h>
11 #include <linux/skbuff.h>
12 #include <linux/linkage.h>
13 #include <linux/printk.h>
14 #include <linux/workqueue.h>
15
16 #include <asm/cacheflush.h>
17
18 #include <uapi/linux/filter.h>
19 #include <uapi/linux/bpf.h>
20
21 struct sk_buff;
22 struct sock;
23 struct seccomp_data;
24 struct bpf_prog_aux;
25
26 /* ArgX, context and stack frame pointer register positions. Note,
27 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
28 * calls in BPF_CALL instruction.
29 */
30 #define BPF_REG_ARG1 BPF_REG_1
31 #define BPF_REG_ARG2 BPF_REG_2
32 #define BPF_REG_ARG3 BPF_REG_3
33 #define BPF_REG_ARG4 BPF_REG_4
34 #define BPF_REG_ARG5 BPF_REG_5
35 #define BPF_REG_CTX BPF_REG_6
36 #define BPF_REG_FP BPF_REG_10
37
38 /* Additional register mappings for converted user programs. */
39 #define BPF_REG_A BPF_REG_0
40 #define BPF_REG_X BPF_REG_7
41 #define BPF_REG_TMP BPF_REG_8
42
43 /* BPF program can access up to 512 bytes of stack space. */
44 #define MAX_BPF_STACK 512
45
46 /* Helper macros for filter block array initializers. */
47
48 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
49
50 #define BPF_ALU64_REG(OP, DST, SRC) \
51 ((struct bpf_insn) { \
52 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
53 .dst_reg = DST, \
54 .src_reg = SRC, \
55 .off = 0, \
56 .imm = 0 })
57
58 #define BPF_ALU32_REG(OP, DST, SRC) \
59 ((struct bpf_insn) { \
60 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
61 .dst_reg = DST, \
62 .src_reg = SRC, \
63 .off = 0, \
64 .imm = 0 })
65
66 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
67
68 #define BPF_ALU64_IMM(OP, DST, IMM) \
69 ((struct bpf_insn) { \
70 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
71 .dst_reg = DST, \
72 .src_reg = 0, \
73 .off = 0, \
74 .imm = IMM })
75
76 #define BPF_ALU32_IMM(OP, DST, IMM) \
77 ((struct bpf_insn) { \
78 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
79 .dst_reg = DST, \
80 .src_reg = 0, \
81 .off = 0, \
82 .imm = IMM })
83
84 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
85
86 #define BPF_ENDIAN(TYPE, DST, LEN) \
87 ((struct bpf_insn) { \
88 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
89 .dst_reg = DST, \
90 .src_reg = 0, \
91 .off = 0, \
92 .imm = LEN })
93
94 /* Short form of mov, dst_reg = src_reg */
95
96 #define BPF_MOV64_REG(DST, SRC) \
97 ((struct bpf_insn) { \
98 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
99 .dst_reg = DST, \
100 .src_reg = SRC, \
101 .off = 0, \
102 .imm = 0 })
103
104 #define BPF_MOV32_REG(DST, SRC) \
105 ((struct bpf_insn) { \
106 .code = BPF_ALU | BPF_MOV | BPF_X, \
107 .dst_reg = DST, \
108 .src_reg = SRC, \
109 .off = 0, \
110 .imm = 0 })
111
112 /* Short form of mov, dst_reg = imm32 */
113
114 #define BPF_MOV64_IMM(DST, IMM) \
115 ((struct bpf_insn) { \
116 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
117 .dst_reg = DST, \
118 .src_reg = 0, \
119 .off = 0, \
120 .imm = IMM })
121
122 #define BPF_MOV32_IMM(DST, IMM) \
123 ((struct bpf_insn) { \
124 .code = BPF_ALU | BPF_MOV | BPF_K, \
125 .dst_reg = DST, \
126 .src_reg = 0, \
127 .off = 0, \
128 .imm = IMM })
129
130 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
131 #define BPF_LD_IMM64(DST, IMM) \
132 BPF_LD_IMM64_RAW(DST, 0, IMM)
133
134 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
135 ((struct bpf_insn) { \
136 .code = BPF_LD | BPF_DW | BPF_IMM, \
137 .dst_reg = DST, \
138 .src_reg = SRC, \
139 .off = 0, \
140 .imm = (__u32) (IMM) }), \
141 ((struct bpf_insn) { \
142 .code = 0, /* zero is reserved opcode */ \
143 .dst_reg = 0, \
144 .src_reg = 0, \
145 .off = 0, \
146 .imm = ((__u64) (IMM)) >> 32 })
147
148 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
149 #define BPF_LD_MAP_FD(DST, MAP_FD) \
150 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
151
152 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
153
154 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
155 ((struct bpf_insn) { \
156 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
157 .dst_reg = DST, \
158 .src_reg = SRC, \
159 .off = 0, \
160 .imm = IMM })
161
162 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
163 ((struct bpf_insn) { \
164 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
165 .dst_reg = DST, \
166 .src_reg = SRC, \
167 .off = 0, \
168 .imm = IMM })
169
170 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
171
172 #define BPF_LD_ABS(SIZE, IMM) \
173 ((struct bpf_insn) { \
174 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
175 .dst_reg = 0, \
176 .src_reg = 0, \
177 .off = 0, \
178 .imm = IMM })
179
180 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
181
182 #define BPF_LD_IND(SIZE, SRC, IMM) \
183 ((struct bpf_insn) { \
184 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
185 .dst_reg = 0, \
186 .src_reg = SRC, \
187 .off = 0, \
188 .imm = IMM })
189
190 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
191
192 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
193 ((struct bpf_insn) { \
194 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
195 .dst_reg = DST, \
196 .src_reg = SRC, \
197 .off = OFF, \
198 .imm = 0 })
199
200 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
201
202 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
203 ((struct bpf_insn) { \
204 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
205 .dst_reg = DST, \
206 .src_reg = SRC, \
207 .off = OFF, \
208 .imm = 0 })
209
210 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
211
212 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
213 ((struct bpf_insn) { \
214 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
215 .dst_reg = DST, \
216 .src_reg = SRC, \
217 .off = OFF, \
218 .imm = 0 })
219
220 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
221
222 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
223 ((struct bpf_insn) { \
224 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
225 .dst_reg = DST, \
226 .src_reg = 0, \
227 .off = OFF, \
228 .imm = IMM })
229
230 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
231
232 #define BPF_JMP_REG(OP, DST, SRC, OFF) \
233 ((struct bpf_insn) { \
234 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
235 .dst_reg = DST, \
236 .src_reg = SRC, \
237 .off = OFF, \
238 .imm = 0 })
239
240 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
241
242 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \
243 ((struct bpf_insn) { \
244 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
245 .dst_reg = DST, \
246 .src_reg = 0, \
247 .off = OFF, \
248 .imm = IMM })
249
250 /* Function call */
251
252 #define BPF_EMIT_CALL(FUNC) \
253 ((struct bpf_insn) { \
254 .code = BPF_JMP | BPF_CALL, \
255 .dst_reg = 0, \
256 .src_reg = 0, \
257 .off = 0, \
258 .imm = ((FUNC) - __bpf_call_base) })
259
260 /* Raw code statement block */
261
262 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
263 ((struct bpf_insn) { \
264 .code = CODE, \
265 .dst_reg = DST, \
266 .src_reg = SRC, \
267 .off = OFF, \
268 .imm = IMM })
269
270 /* Program exit */
271
272 #define BPF_EXIT_INSN() \
273 ((struct bpf_insn) { \
274 .code = BPF_JMP | BPF_EXIT, \
275 .dst_reg = 0, \
276 .src_reg = 0, \
277 .off = 0, \
278 .imm = 0 })
279
280 /* Internal classic blocks for direct assignment */
281
282 #define __BPF_STMT(CODE, K) \
283 ((struct sock_filter) BPF_STMT(CODE, K))
284
285 #define __BPF_JUMP(CODE, K, JT, JF) \
286 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
287
288 #define bytes_to_bpf_size(bytes) \
289 ({ \
290 int bpf_size = -EINVAL; \
291 \
292 if (bytes == sizeof(u8)) \
293 bpf_size = BPF_B; \
294 else if (bytes == sizeof(u16)) \
295 bpf_size = BPF_H; \
296 else if (bytes == sizeof(u32)) \
297 bpf_size = BPF_W; \
298 else if (bytes == sizeof(u64)) \
299 bpf_size = BPF_DW; \
300 \
301 bpf_size; \
302 })
303
304 /* Macro to invoke filter function. */
305 #define SK_RUN_FILTER(filter, ctx) \
306 (*filter->prog->bpf_func)(ctx, filter->prog->insnsi)
307
308 #ifdef CONFIG_COMPAT
309 /* A struct sock_filter is architecture independent. */
310 struct compat_sock_fprog {
311 u16 len;
312 compat_uptr_t filter; /* struct sock_filter * */
313 };
314 #endif
315
316 struct sock_fprog_kern {
317 u16 len;
318 struct sock_filter *filter;
319 };
320
321 struct bpf_binary_header {
322 unsigned int pages;
323 u8 image[];
324 };
325
326 struct bpf_prog {
327 u16 pages; /* Number of allocated pages */
328 bool jited; /* Is our filter JIT'ed? */
329 bool gpl_compatible; /* Is our filter GPL compatible? */
330 u32 len; /* Number of filter blocks */
331 enum bpf_prog_type type; /* Type of BPF program */
332 struct bpf_prog_aux *aux; /* Auxiliary fields */
333 struct sock_fprog_kern *orig_prog; /* Original BPF program */
334 unsigned int (*bpf_func)(const struct sk_buff *skb,
335 const struct bpf_insn *filter);
336 /* Instructions for interpreter */
337 union {
338 struct sock_filter insns[0];
339 struct bpf_insn insnsi[0];
340 };
341 };
342
343 struct sk_filter {
344 atomic_t refcnt;
345 struct rcu_head rcu;
346 struct bpf_prog *prog;
347 };
348
349 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
350
351 static inline unsigned int bpf_prog_size(unsigned int proglen)
352 {
353 return max(sizeof(struct bpf_prog),
354 offsetof(struct bpf_prog, insns[proglen]));
355 }
356
357 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
358 {
359 /* When classic BPF programs have been loaded and the arch
360 * does not have a classic BPF JIT (anymore), they have been
361 * converted via bpf_migrate_filter() to eBPF and thus always
362 * have an unspec program type.
363 */
364 return prog->type == BPF_PROG_TYPE_UNSPEC;
365 }
366
367 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
368
369 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
370 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
371 {
372 set_memory_ro((unsigned long)fp, fp->pages);
373 }
374
375 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
376 {
377 set_memory_rw((unsigned long)fp, fp->pages);
378 }
379 #else
380 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
381 {
382 }
383
384 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
385 {
386 }
387 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */
388
389 int sk_filter(struct sock *sk, struct sk_buff *skb);
390
391 int bpf_prog_select_runtime(struct bpf_prog *fp);
392 void bpf_prog_free(struct bpf_prog *fp);
393
394 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
395 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
396 gfp_t gfp_extra_flags);
397 void __bpf_prog_free(struct bpf_prog *fp);
398
399 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
400 {
401 bpf_prog_unlock_ro(fp);
402 __bpf_prog_free(fp);
403 }
404
405 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
406 unsigned int flen);
407
408 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
409 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
410 bpf_aux_classic_check_t trans);
411 void bpf_prog_destroy(struct bpf_prog *fp);
412
413 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
414 int sk_attach_bpf(u32 ufd, struct sock *sk);
415 int sk_detach_filter(struct sock *sk);
416 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
417 unsigned int len);
418
419 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
420 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
421
422 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
423 void bpf_int_jit_compile(struct bpf_prog *fp);
424 bool bpf_helper_changes_skb_data(void *func);
425
426 #ifdef CONFIG_BPF_JIT
427 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
428
429 struct bpf_binary_header *
430 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
431 unsigned int alignment,
432 bpf_jit_fill_hole_t bpf_fill_ill_insns);
433 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
434
435 void bpf_jit_compile(struct bpf_prog *fp);
436 void bpf_jit_free(struct bpf_prog *fp);
437
438 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
439 u32 pass, void *image)
440 {
441 pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
442 flen, proglen, pass, image);
443 if (image)
444 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
445 16, 1, image, proglen, false);
446 }
447 #else
448 static inline void bpf_jit_compile(struct bpf_prog *fp)
449 {
450 }
451
452 static inline void bpf_jit_free(struct bpf_prog *fp)
453 {
454 bpf_prog_unlock_free(fp);
455 }
456 #endif /* CONFIG_BPF_JIT */
457
458 #define BPF_ANC BIT(15)
459
460 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
461 {
462 BUG_ON(ftest->code & BPF_ANC);
463
464 switch (ftest->code) {
465 case BPF_LD | BPF_W | BPF_ABS:
466 case BPF_LD | BPF_H | BPF_ABS:
467 case BPF_LD | BPF_B | BPF_ABS:
468 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
469 return BPF_ANC | SKF_AD_##CODE
470 switch (ftest->k) {
471 BPF_ANCILLARY(PROTOCOL);
472 BPF_ANCILLARY(PKTTYPE);
473 BPF_ANCILLARY(IFINDEX);
474 BPF_ANCILLARY(NLATTR);
475 BPF_ANCILLARY(NLATTR_NEST);
476 BPF_ANCILLARY(MARK);
477 BPF_ANCILLARY(QUEUE);
478 BPF_ANCILLARY(HATYPE);
479 BPF_ANCILLARY(RXHASH);
480 BPF_ANCILLARY(CPU);
481 BPF_ANCILLARY(ALU_XOR_X);
482 BPF_ANCILLARY(VLAN_TAG);
483 BPF_ANCILLARY(VLAN_TAG_PRESENT);
484 BPF_ANCILLARY(PAY_OFFSET);
485 BPF_ANCILLARY(RANDOM);
486 BPF_ANCILLARY(VLAN_TPID);
487 }
488 /* Fallthrough. */
489 default:
490 return ftest->code;
491 }
492 }
493
494 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
495 int k, unsigned int size);
496
497 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
498 unsigned int size, void *buffer)
499 {
500 if (k >= 0)
501 return skb_header_pointer(skb, k, size, buffer);
502
503 return bpf_internal_load_pointer_neg_helper(skb, k, size);
504 }
505
506 static inline int bpf_tell_extensions(void)
507 {
508 return SKF_AD_MAX;
509 }
510
511 #endif /* __LINUX_FILTER_H__ */
Linux kernel - Deliverables
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