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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / include / linux / filter.h
blob276932d759750dea5d0865308f589fcb7c61b191
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Linux Socket Filter Data Structures
4 */
5 #ifndef __LINUX_FILTER_H__
6 #define __LINUX_FILTER_H__
7
8 #include <stdarg.h>
9
10 #include <linux/atomic.h>
11 #include <linux/refcount.h>
12 #include <linux/compat.h>
13 #include <linux/skbuff.h>
14 #include <linux/linkage.h>
15 #include <linux/printk.h>
16 #include <linux/workqueue.h>
17 #include <linux/sched.h>
18 #include <linux/capability.h>
19 #include <linux/cryptohash.h>
20 #include <linux/set_memory.h>
21 #include <linux/kallsyms.h>
22
23 #include <net/xdp.h>
24 #include <net/sch_generic.h>
25
26 #include <uapi/linux/filter.h>
27 #include <uapi/linux/bpf.h>
28
29 struct sk_buff;
30 struct sock;
31 struct seccomp_data;
32 struct bpf_prog_aux;
33
34 /* ArgX, context and stack frame pointer register positions. Note,
35 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
36 * calls in BPF_CALL instruction.
37 */
38 #define BPF_REG_ARG1 BPF_REG_1
39 #define BPF_REG_ARG2 BPF_REG_2
40 #define BPF_REG_ARG3 BPF_REG_3
41 #define BPF_REG_ARG4 BPF_REG_4
42 #define BPF_REG_ARG5 BPF_REG_5
43 #define BPF_REG_CTX BPF_REG_6
44 #define BPF_REG_FP BPF_REG_10
45
46 /* Additional register mappings for converted user programs. */
47 #define BPF_REG_A BPF_REG_0
48 #define BPF_REG_X BPF_REG_7
49 #define BPF_REG_TMP BPF_REG_8
50
51 /* Kernel hidden auxiliary/helper register for hardening step.
52 * Only used by eBPF JITs. It's nothing more than a temporary
53 * register that JITs use internally, only that here it's part
54 * of eBPF instructions that have been rewritten for blinding
55 * constants. See JIT pre-step in bpf_jit_blind_constants().
56 */
57 #define BPF_REG_AX MAX_BPF_REG
58 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1)
59
60 /* unused opcode to mark special call to bpf_tail_call() helper */
61 #define BPF_TAIL_CALL 0xf0
62
63 /* unused opcode to mark call to interpreter with arguments */
64 #define BPF_CALL_ARGS 0xe0
65
66 /* As per nm, we expose JITed images as text (code) section for
67 * kallsyms. That way, tools like perf can find it to match
68 * addresses.
69 */
70 #define BPF_SYM_ELF_TYPE 't'
71
72 /* BPF program can access up to 512 bytes of stack space. */
73 #define MAX_BPF_STACK 512
74
75 /* Helper macros for filter block array initializers. */
76
77 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
78
79 #define BPF_ALU64_REG(OP, DST, SRC) \
80 ((struct bpf_insn) { \
81 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
82 .dst_reg = DST, \
83 .src_reg = SRC, \
84 .off = 0, \
85 .imm = 0 })
86
87 #define BPF_ALU32_REG(OP, DST, SRC) \
88 ((struct bpf_insn) { \
89 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
90 .dst_reg = DST, \
91 .src_reg = SRC, \
92 .off = 0, \
93 .imm = 0 })
94
95 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
96
97 #define BPF_ALU64_IMM(OP, DST, IMM) \
98 ((struct bpf_insn) { \
99 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
100 .dst_reg = DST, \
101 .src_reg = 0, \
102 .off = 0, \
103 .imm = IMM })
104
105 #define BPF_ALU32_IMM(OP, DST, IMM) \
106 ((struct bpf_insn) { \
107 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
108 .dst_reg = DST, \
109 .src_reg = 0, \
110 .off = 0, \
111 .imm = IMM })
112
113 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
114
115 #define BPF_ENDIAN(TYPE, DST, LEN) \
116 ((struct bpf_insn) { \
117 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
118 .dst_reg = DST, \
119 .src_reg = 0, \
120 .off = 0, \
121 .imm = LEN })
122
123 /* Short form of mov, dst_reg = src_reg */
124
125 #define BPF_MOV64_REG(DST, SRC) \
126 ((struct bpf_insn) { \
127 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
128 .dst_reg = DST, \
129 .src_reg = SRC, \
130 .off = 0, \
131 .imm = 0 })
132
133 #define BPF_MOV32_REG(DST, SRC) \
134 ((struct bpf_insn) { \
135 .code = BPF_ALU | BPF_MOV | BPF_X, \
136 .dst_reg = DST, \
137 .src_reg = SRC, \
138 .off = 0, \
139 .imm = 0 })
140
141 /* Short form of mov, dst_reg = imm32 */
142
143 #define BPF_MOV64_IMM(DST, IMM) \
144 ((struct bpf_insn) { \
145 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
146 .dst_reg = DST, \
147 .src_reg = 0, \
148 .off = 0, \
149 .imm = IMM })
150
151 #define BPF_MOV32_IMM(DST, IMM) \
152 ((struct bpf_insn) { \
153 .code = BPF_ALU | BPF_MOV | BPF_K, \
154 .dst_reg = DST, \
155 .src_reg = 0, \
156 .off = 0, \
157 .imm = IMM })
158
159 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
160 #define BPF_LD_IMM64(DST, IMM) \
161 BPF_LD_IMM64_RAW(DST, 0, IMM)
162
163 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
164 ((struct bpf_insn) { \
165 .code = BPF_LD | BPF_DW | BPF_IMM, \
166 .dst_reg = DST, \
167 .src_reg = SRC, \
168 .off = 0, \
169 .imm = (__u32) (IMM) }), \
170 ((struct bpf_insn) { \
171 .code = 0, /* zero is reserved opcode */ \
172 .dst_reg = 0, \
173 .src_reg = 0, \
174 .off = 0, \
175 .imm = ((__u64) (IMM)) >> 32 })
176
177 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
178 #define BPF_LD_MAP_FD(DST, MAP_FD) \
179 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
180
181 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
182
183 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
184 ((struct bpf_insn) { \
185 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
186 .dst_reg = DST, \
187 .src_reg = SRC, \
188 .off = 0, \
189 .imm = IMM })
190
191 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
192 ((struct bpf_insn) { \
193 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
194 .dst_reg = DST, \
195 .src_reg = SRC, \
196 .off = 0, \
197 .imm = IMM })
198
199 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
200
201 #define BPF_LD_ABS(SIZE, IMM) \
202 ((struct bpf_insn) { \
203 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
204 .dst_reg = 0, \
205 .src_reg = 0, \
206 .off = 0, \
207 .imm = IMM })
208
209 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
210
211 #define BPF_LD_IND(SIZE, SRC, IMM) \
212 ((struct bpf_insn) { \
213 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
214 .dst_reg = 0, \
215 .src_reg = SRC, \
216 .off = 0, \
217 .imm = IMM })
218
219 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
220
221 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
222 ((struct bpf_insn) { \
223 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
224 .dst_reg = DST, \
225 .src_reg = SRC, \
226 .off = OFF, \
227 .imm = 0 })
228
229 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
230
231 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
232 ((struct bpf_insn) { \
233 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
234 .dst_reg = DST, \
235 .src_reg = SRC, \
236 .off = OFF, \
237 .imm = 0 })
238
239 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
240
241 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
242 ((struct bpf_insn) { \
243 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
244 .dst_reg = DST, \
245 .src_reg = SRC, \
246 .off = OFF, \
247 .imm = 0 })
248
249 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
250
251 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
252 ((struct bpf_insn) { \
253 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
254 .dst_reg = DST, \
255 .src_reg = 0, \
256 .off = OFF, \
257 .imm = IMM })
258
259 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
260
261 #define BPF_JMP_REG(OP, DST, SRC, OFF) \
262 ((struct bpf_insn) { \
263 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
264 .dst_reg = DST, \
265 .src_reg = SRC, \
266 .off = OFF, \
267 .imm = 0 })
268
269 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
270
271 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \
272 ((struct bpf_insn) { \
273 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
274 .dst_reg = DST, \
275 .src_reg = 0, \
276 .off = OFF, \
277 .imm = IMM })
278
279 /* Unconditional jumps, goto pc + off16 */
280
281 #define BPF_JMP_A(OFF) \
282 ((struct bpf_insn) { \
283 .code = BPF_JMP | BPF_JA, \
284 .dst_reg = 0, \
285 .src_reg = 0, \
286 .off = OFF, \
287 .imm = 0 })
288
289 /* Function call */
290
291 #define BPF_EMIT_CALL(FUNC) \
292 ((struct bpf_insn) { \
293 .code = BPF_JMP | BPF_CALL, \
294 .dst_reg = 0, \
295 .src_reg = 0, \
296 .off = 0, \
297 .imm = ((FUNC) - __bpf_call_base) })
298
299 /* Raw code statement block */
300
301 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
302 ((struct bpf_insn) { \
303 .code = CODE, \
304 .dst_reg = DST, \
305 .src_reg = SRC, \
306 .off = OFF, \
307 .imm = IMM })
308
309 /* Program exit */
310
311 #define BPF_EXIT_INSN() \
312 ((struct bpf_insn) { \
313 .code = BPF_JMP | BPF_EXIT, \
314 .dst_reg = 0, \
315 .src_reg = 0, \
316 .off = 0, \
317 .imm = 0 })
318
319 /* Internal classic blocks for direct assignment */
320
321 #define __BPF_STMT(CODE, K) \
322 ((struct sock_filter) BPF_STMT(CODE, K))
323
324 #define __BPF_JUMP(CODE, K, JT, JF) \
325 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
326
327 #define bytes_to_bpf_size(bytes) \
328 ({ \
329 int bpf_size = -EINVAL; \
330 \
331 if (bytes == sizeof(u8)) \
332 bpf_size = BPF_B; \
333 else if (bytes == sizeof(u16)) \
334 bpf_size = BPF_H; \
335 else if (bytes == sizeof(u32)) \
336 bpf_size = BPF_W; \
337 else if (bytes == sizeof(u64)) \
338 bpf_size = BPF_DW; \
339 \
340 bpf_size; \
341 })
342
343 #define bpf_size_to_bytes(bpf_size) \
344 ({ \
345 int bytes = -EINVAL; \
346 \
347 if (bpf_size == BPF_B) \
348 bytes = sizeof(u8); \
349 else if (bpf_size == BPF_H) \
350 bytes = sizeof(u16); \
351 else if (bpf_size == BPF_W) \
352 bytes = sizeof(u32); \
353 else if (bpf_size == BPF_DW) \
354 bytes = sizeof(u64); \
355 \
356 bytes; \
357 })
358
359 #define BPF_SIZEOF(type) \
360 ({ \
361 const int __size = bytes_to_bpf_size(sizeof(type)); \
362 BUILD_BUG_ON(__size < 0); \
363 __size; \
364 })
365
366 #define BPF_FIELD_SIZEOF(type, field) \
367 ({ \
368 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
369 BUILD_BUG_ON(__size < 0); \
370 __size; \
371 })
372
373 #define BPF_LDST_BYTES(insn) \
374 ({ \
375 const int __size = bpf_size_to_bytes(BPF_SIZE(insn->code)); \
376 WARN_ON(__size < 0); \
377 __size; \
378 })
379
380 #define __BPF_MAP_0(m, v, ...) v
381 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
382 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
383 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
384 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
385 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
386
387 #define __BPF_REG_0(...) __BPF_PAD(5)
388 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
389 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
390 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
391 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
392 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
393
394 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
395 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
396
397 #define __BPF_CAST(t, a) \
398 (__force t) \
399 (__force \
400 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \
401 (unsigned long)0, (t)0))) a
402 #define __BPF_V void
403 #define __BPF_N
404
405 #define __BPF_DECL_ARGS(t, a) t a
406 #define __BPF_DECL_REGS(t, a) u64 a
407
408 #define __BPF_PAD(n) \
409 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \
410 u64, __ur_3, u64, __ur_4, u64, __ur_5)
411
412 #define BPF_CALL_x(x, name, ...) \
413 static __always_inline \
414 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
415 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \
416 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \
417 { \
418 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
419 } \
420 static __always_inline \
421 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
422
423 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__)
424 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__)
425 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__)
426 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__)
427 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__)
428 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__)
429
430 #define bpf_ctx_range(TYPE, MEMBER) \
431 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
432 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \
433 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
434
435 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \
436 ({ \
437 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \
438 *(PTR_SIZE) = (SIZE); \
439 offsetof(TYPE, MEMBER); \
440 })
441
442 #ifdef CONFIG_COMPAT
443 /* A struct sock_filter is architecture independent. */
444 struct compat_sock_fprog {
445 u16 len;
446 compat_uptr_t filter; /* struct sock_filter * */
447 };
448 #endif
449
450 struct sock_fprog_kern {
451 u16 len;
452 struct sock_filter *filter;
453 };
454
455 struct bpf_binary_header {
456 unsigned int pages;
457 u8 image[];
458 };
459
460 struct bpf_prog {
461 u16 pages; /* Number of allocated pages */
462 u16 jited:1, /* Is our filter JIT'ed? */
463 jit_requested:1,/* archs need to JIT the prog */
464 locked:1, /* Program image locked? */
465 gpl_compatible:1, /* Is filter GPL compatible? */
466 cb_access:1, /* Is control block accessed? */
467 dst_needed:1, /* Do we need dst entry? */
468 blinded:1, /* Was blinded */
469 is_func:1, /* program is a bpf function */
470 kprobe_override:1; /* Do we override a kprobe? */
471 enum bpf_prog_type type; /* Type of BPF program */
472 u32 len; /* Number of filter blocks */
473 u32 jited_len; /* Size of jited insns in bytes */
474 u8 tag[BPF_TAG_SIZE];
475 struct bpf_prog_aux *aux; /* Auxiliary fields */
476 struct sock_fprog_kern *orig_prog; /* Original BPF program */
477 unsigned int (*bpf_func)(const void *ctx,
478 const struct bpf_insn *insn);
479 /* Instructions for interpreter */
480 union {
481 struct sock_filter insns[0];
482 struct bpf_insn insnsi[0];
483 };
484 };
485
486 struct sk_filter {
487 refcount_t refcnt;
488 struct rcu_head rcu;
489 struct bpf_prog *prog;
490 };
491
492 #define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi)
493
494 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
495
496 struct bpf_skb_data_end {
497 struct qdisc_skb_cb qdisc_cb;
498 void *data_meta;
499 void *data_end;
500 };
501
502 struct xdp_buff {
503 void *data;
504 void *data_end;
505 void *data_meta;
506 void *data_hard_start;
507 struct xdp_rxq_info *rxq;
508 };
509
510 /* Compute the linear packet data range [data, data_end) which
511 * will be accessed by various program types (cls_bpf, act_bpf,
512 * lwt, ...). Subsystems allowing direct data access must (!)
513 * ensure that cb[] area can be written to when BPF program is
514 * invoked (otherwise cb[] save/restore is necessary).
515 */
516 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
517 {
518 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
519
520 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
521 cb->data_meta = skb->data - skb_metadata_len(skb);
522 cb->data_end = skb->data + skb_headlen(skb);
523 }
524
525 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
526 {
527 /* eBPF programs may read/write skb->cb[] area to transfer meta
528 * data between tail calls. Since this also needs to work with
529 * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
530 *
531 * In some socket filter cases, the cb unfortunately needs to be
532 * saved/restored so that protocol specific skb->cb[] data won't
533 * be lost. In any case, due to unpriviledged eBPF programs
534 * attached to sockets, we need to clear the bpf_skb_cb() area
535 * to not leak previous contents to user space.
536 */
537 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
538 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
539 FIELD_SIZEOF(struct qdisc_skb_cb, data));
540
541 return qdisc_skb_cb(skb)->data;
542 }
543
544 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
545 struct sk_buff *skb)
546 {
547 u8 *cb_data = bpf_skb_cb(skb);
548 u8 cb_saved[BPF_SKB_CB_LEN];
549 u32 res;
550
551 if (unlikely(prog->cb_access)) {
552 memcpy(cb_saved, cb_data, sizeof(cb_saved));
553 memset(cb_data, 0, sizeof(cb_saved));
554 }
555
556 res = BPF_PROG_RUN(prog, skb);
557
558 if (unlikely(prog->cb_access))
559 memcpy(cb_data, cb_saved, sizeof(cb_saved));
560
561 return res;
562 }
563
564 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
565 struct sk_buff *skb)
566 {
567 u8 *cb_data = bpf_skb_cb(skb);
568
569 if (unlikely(prog->cb_access))
570 memset(cb_data, 0, BPF_SKB_CB_LEN);
571
572 return BPF_PROG_RUN(prog, skb);
573 }
574
575 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
576 struct xdp_buff *xdp)
577 {
578 /* Caller needs to hold rcu_read_lock() (!), otherwise program
579 * can be released while still running, or map elements could be
580 * freed early while still having concurrent users. XDP fastpath
581 * already takes rcu_read_lock() when fetching the program, so
582 * it's not necessary here anymore.
583 */
584 return BPF_PROG_RUN(prog, xdp);
585 }
586
587 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
588 {
589 return prog->len * sizeof(struct bpf_insn);
590 }
591
592 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
593 {
594 return round_up(bpf_prog_insn_size(prog) +
595 sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
596 }
597
598 static inline unsigned int bpf_prog_size(unsigned int proglen)
599 {
600 return max(sizeof(struct bpf_prog),
601 offsetof(struct bpf_prog, insns[proglen]));
602 }
603
604 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
605 {
606 /* When classic BPF programs have been loaded and the arch
607 * does not have a classic BPF JIT (anymore), they have been
608 * converted via bpf_migrate_filter() to eBPF and thus always
609 * have an unspec program type.
610 */
611 return prog->type == BPF_PROG_TYPE_UNSPEC;
612 }
613
614 static inline bool
615 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default)
616 {
617 bool off_ok;
618 #ifdef __LITTLE_ENDIAN
619 off_ok = (off & (size_default - 1)) == 0;
620 #else
621 off_ok = (off & (size_default - 1)) + size == size_default;
622 #endif
623 return off_ok && size <= size_default && (size & (size - 1)) == 0;
624 }
625
626 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
627
628 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
629 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
630 {
631 fp->locked = 1;
632 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
633 }
634
635 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
636 {
637 if (fp->locked) {
638 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
639 /* In case set_memory_rw() fails, we want to be the first
640 * to crash here instead of some random place later on.
641 */
642 fp->locked = 0;
643 }
644 }
645
646 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
647 {
648 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
649 }
650
651 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
652 {
653 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
654 }
655 #else
656 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
657 {
658 }
659
660 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
661 {
662 }
663
664 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
665 {
666 }
667
668 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
669 {
670 }
671 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
672
673 static inline struct bpf_binary_header *
674 bpf_jit_binary_hdr(const struct bpf_prog *fp)
675 {
676 unsigned long real_start = (unsigned long)fp->bpf_func;
677 unsigned long addr = real_start & PAGE_MASK;
678
679 return (void *)addr;
680 }
681
682 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
683 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
684 {
685 return sk_filter_trim_cap(sk, skb, 1);
686 }
687
688 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
689 void bpf_prog_free(struct bpf_prog *fp);
690
691 bool bpf_opcode_in_insntable(u8 code);
692
693 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
694 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
695 gfp_t gfp_extra_flags);
696 void __bpf_prog_free(struct bpf_prog *fp);
697
698 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
699 {
700 bpf_prog_unlock_ro(fp);
701 __bpf_prog_free(fp);
702 }
703
704 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
705 unsigned int flen);
706
707 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
708 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
709 bpf_aux_classic_check_t trans, bool save_orig);
710 void bpf_prog_destroy(struct bpf_prog *fp);
711
712 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
713 int sk_attach_bpf(u32 ufd, struct sock *sk);
714 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
715 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
716 int sk_detach_filter(struct sock *sk);
717 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
718 unsigned int len);
719
720 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
721 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
722
723 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
724 #define __bpf_call_base_args \
725 ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
726 __bpf_call_base)
727
728 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
729 void bpf_jit_compile(struct bpf_prog *prog);
730 bool bpf_helper_changes_pkt_data(void *func);
731
732 static inline bool bpf_dump_raw_ok(void)
733 {
734 /* Reconstruction of call-sites is dependent on kallsyms,
735 * thus make dump the same restriction.
736 */
737 return kallsyms_show_value() == 1;
738 }
739
740 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
741 const struct bpf_insn *patch, u32 len);
742
743 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
744 * same cpu context. Further for best results no more than a single map
745 * for the do_redirect/do_flush pair should be used. This limitation is
746 * because we only track one map and force a flush when the map changes.
747 * This does not appear to be a real limitation for existing software.
748 */
749 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
750 struct bpf_prog *prog);
751 int xdp_do_redirect(struct net_device *dev,
752 struct xdp_buff *xdp,
753 struct bpf_prog *prog);
754 void xdp_do_flush_map(void);
755
756 /* Drivers not supporting XDP metadata can use this helper, which
757 * rejects any room expansion for metadata as a result.
758 */
759 static __always_inline void
760 xdp_set_data_meta_invalid(struct xdp_buff *xdp)
761 {
762 xdp->data_meta = xdp->data + 1;
763 }
764
765 static __always_inline bool
766 xdp_data_meta_unsupported(const struct xdp_buff *xdp)
767 {
768 return unlikely(xdp->data_meta > xdp->data);
769 }
770
771 void bpf_warn_invalid_xdp_action(u32 act);
772
773 struct sock *do_sk_redirect_map(struct sk_buff *skb);
774
775 #ifdef CONFIG_BPF_JIT
776 extern int bpf_jit_enable;
777 extern int bpf_jit_harden;
778 extern int bpf_jit_kallsyms;
779
780 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
781
782 struct bpf_binary_header *
783 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
784 unsigned int alignment,
785 bpf_jit_fill_hole_t bpf_fill_ill_insns);
786 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
787
788 void bpf_jit_free(struct bpf_prog *fp);
789
790 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
791 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
792
793 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
794 u32 pass, void *image)
795 {
796 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
797 proglen, pass, image, current->comm, task_pid_nr(current));
798
799 if (image)
800 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
801 16, 1, image, proglen, false);
802 }
803
804 static inline bool bpf_jit_is_ebpf(void)
805 {
806 # ifdef CONFIG_HAVE_EBPF_JIT
807 return true;
808 # else
809 return false;
810 # endif
811 }
812
813 static inline bool ebpf_jit_enabled(void)
814 {
815 return bpf_jit_enable && bpf_jit_is_ebpf();
816 }
817
818 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
819 {
820 return fp->jited && bpf_jit_is_ebpf();
821 }
822
823 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
824 {
825 /* These are the prerequisites, should someone ever have the
826 * idea to call blinding outside of them, we make sure to
827 * bail out.
828 */
829 if (!bpf_jit_is_ebpf())
830 return false;
831 if (!prog->jit_requested)
832 return false;
833 if (!bpf_jit_harden)
834 return false;
835 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
836 return false;
837
838 return true;
839 }
840
841 static inline bool bpf_jit_kallsyms_enabled(void)
842 {
843 /* There are a couple of corner cases where kallsyms should
844 * not be enabled f.e. on hardening.
845 */
846 if (bpf_jit_harden)
847 return false;
848 if (!bpf_jit_kallsyms)
849 return false;
850 if (bpf_jit_kallsyms == 1)
851 return true;
852
853 return false;
854 }
855
856 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
857 unsigned long *off, char *sym);
858 bool is_bpf_text_address(unsigned long addr);
859 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
860 char *sym);
861
862 static inline const char *
863 bpf_address_lookup(unsigned long addr, unsigned long *size,
864 unsigned long *off, char **modname, char *sym)
865 {
866 const char *ret = __bpf_address_lookup(addr, size, off, sym);
867
868 if (ret && modname)
869 *modname = NULL;
870 return ret;
871 }
872
873 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
874 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
875
876 #else /* CONFIG_BPF_JIT */
877
878 static inline bool ebpf_jit_enabled(void)
879 {
880 return false;
881 }
882
883 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
884 {
885 return false;
886 }
887
888 static inline void bpf_jit_free(struct bpf_prog *fp)
889 {
890 bpf_prog_unlock_free(fp);
891 }
892
893 static inline bool bpf_jit_kallsyms_enabled(void)
894 {
895 return false;
896 }
897
898 static inline const char *
899 __bpf_address_lookup(unsigned long addr, unsigned long *size,
900 unsigned long *off, char *sym)
901 {
902 return NULL;
903 }
904
905 static inline bool is_bpf_text_address(unsigned long addr)
906 {
907 return false;
908 }
909
910 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
911 char *type, char *sym)
912 {
913 return -ERANGE;
914 }
915
916 static inline const char *
917 bpf_address_lookup(unsigned long addr, unsigned long *size,
918 unsigned long *off, char **modname, char *sym)
919 {
920 return NULL;
921 }
922
923 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
924 {
925 }
926
927 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
928 {
929 }
930 #endif /* CONFIG_BPF_JIT */
931
932 #define BPF_ANC BIT(15)
933
934 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
935 {
936 switch (first->code) {
937 case BPF_RET | BPF_K:
938 case BPF_LD | BPF_W | BPF_LEN:
939 return false;
940
941 case BPF_LD | BPF_W | BPF_ABS:
942 case BPF_LD | BPF_H | BPF_ABS:
943 case BPF_LD | BPF_B | BPF_ABS:
944 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
945 return true;
946 return false;
947
948 default:
949 return true;
950 }
951 }
952
953 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
954 {
955 BUG_ON(ftest->code & BPF_ANC);
956
957 switch (ftest->code) {
958 case BPF_LD | BPF_W | BPF_ABS:
959 case BPF_LD | BPF_H | BPF_ABS:
960 case BPF_LD | BPF_B | BPF_ABS:
961 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
962 return BPF_ANC | SKF_AD_##CODE
963 switch (ftest->k) {
964 BPF_ANCILLARY(PROTOCOL);
965 BPF_ANCILLARY(PKTTYPE);
966 BPF_ANCILLARY(IFINDEX);
967 BPF_ANCILLARY(NLATTR);
968 BPF_ANCILLARY(NLATTR_NEST);
969 BPF_ANCILLARY(MARK);
970 BPF_ANCILLARY(QUEUE);
971 BPF_ANCILLARY(HATYPE);
972 BPF_ANCILLARY(RXHASH);
973 BPF_ANCILLARY(CPU);
974 BPF_ANCILLARY(ALU_XOR_X);
975 BPF_ANCILLARY(VLAN_TAG);
976 BPF_ANCILLARY(VLAN_TAG_PRESENT);
977 BPF_ANCILLARY(PAY_OFFSET);
978 BPF_ANCILLARY(RANDOM);
979 BPF_ANCILLARY(VLAN_TPID);
980 }
981 /* Fallthrough. */
982 default:
983 return ftest->code;
984 }
985 }
986
987 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
988 int k, unsigned int size);
989
990 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
991 unsigned int size, void *buffer)
992 {
993 if (k >= 0)
994 return skb_header_pointer(skb, k, size, buffer);
995
996 return bpf_internal_load_pointer_neg_helper(skb, k, size);
997 }
998
999 static inline int bpf_tell_extensions(void)
1000 {
1001 return SKF_AD_MAX;
1002 }
1003
1004 struct bpf_sock_ops_kern {
1005 struct sock *sk;
1006 u32 op;
1007 union {
1008 u32 args[4];
1009 u32 reply;
1010 u32 replylong[4];
1011 };
1012 u32 is_fullsock;
1013 u64 temp; /* temp and everything after is not
1014 * initialized to 0 before calling
1015 * the BPF program. New fields that
1016 * should be initialized to 0 should
1017 * be inserted before temp.
1018 * temp is scratch storage used by
1019 * sock_ops_convert_ctx_access
1020 * as temporary storage of a register.
1021 */
1022 };
1023
1024 #endif /* __LINUX_FILTER_H__ */
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