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signal: Fix sending signals with siginfo
[cris-mirror.git] / include / linux / filter.h
blobbfef1e5734f8a8da5b06c3ad44d36bda7af3a06d
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/refcount.h>
11 #include <linux/compat.h>
12 #include <linux/skbuff.h>
13 #include <linux/linkage.h>
14 #include <linux/printk.h>
15 #include <linux/workqueue.h>
16 #include <linux/sched.h>
17 #include <linux/capability.h>
18 #include <linux/cryptohash.h>
19 #include <linux/set_memory.h>
20
21 #include <net/sch_generic.h>
22
23 #include <uapi/linux/filter.h>
24 #include <uapi/linux/bpf.h>
25
26 struct sk_buff;
27 struct sock;
28 struct seccomp_data;
29 struct bpf_prog_aux;
30
31 /* ArgX, context and stack frame pointer register positions. Note,
32 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
33 * calls in BPF_CALL instruction.
34 */
35 #define BPF_REG_ARG1 BPF_REG_1
36 #define BPF_REG_ARG2 BPF_REG_2
37 #define BPF_REG_ARG3 BPF_REG_3
38 #define BPF_REG_ARG4 BPF_REG_4
39 #define BPF_REG_ARG5 BPF_REG_5
40 #define BPF_REG_CTX BPF_REG_6
41 #define BPF_REG_FP BPF_REG_10
42
43 /* Additional register mappings for converted user programs. */
44 #define BPF_REG_A BPF_REG_0
45 #define BPF_REG_X BPF_REG_7
46 #define BPF_REG_TMP BPF_REG_8
47
48 /* Kernel hidden auxiliary/helper register for hardening step.
49 * Only used by eBPF JITs. It's nothing more than a temporary
50 * register that JITs use internally, only that here it's part
51 * of eBPF instructions that have been rewritten for blinding
52 * constants. See JIT pre-step in bpf_jit_blind_constants().
53 */
54 #define BPF_REG_AX MAX_BPF_REG
55 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1)
56
57 /* unused opcode to mark special call to bpf_tail_call() helper */
58 #define BPF_TAIL_CALL 0xf0
59
60 /* As per nm, we expose JITed images as text (code) section for
61 * kallsyms. That way, tools like perf can find it to match
62 * addresses.
63 */
64 #define BPF_SYM_ELF_TYPE 't'
65
66 /* BPF program can access up to 512 bytes of stack space. */
67 #define MAX_BPF_STACK 512
68
69 /* Helper macros for filter block array initializers. */
70
71 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
72
73 #define BPF_ALU64_REG(OP, DST, SRC) \
74 ((struct bpf_insn) { \
75 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
76 .dst_reg = DST, \
77 .src_reg = SRC, \
78 .off = 0, \
79 .imm = 0 })
80
81 #define BPF_ALU32_REG(OP, DST, SRC) \
82 ((struct bpf_insn) { \
83 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
84 .dst_reg = DST, \
85 .src_reg = SRC, \
86 .off = 0, \
87 .imm = 0 })
88
89 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
90
91 #define BPF_ALU64_IMM(OP, DST, IMM) \
92 ((struct bpf_insn) { \
93 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
94 .dst_reg = DST, \
95 .src_reg = 0, \
96 .off = 0, \
97 .imm = IMM })
98
99 #define BPF_ALU32_IMM(OP, DST, IMM) \
100 ((struct bpf_insn) { \
101 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
102 .dst_reg = DST, \
103 .src_reg = 0, \
104 .off = 0, \
105 .imm = IMM })
106
107 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
108
109 #define BPF_ENDIAN(TYPE, DST, LEN) \
110 ((struct bpf_insn) { \
111 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
112 .dst_reg = DST, \
113 .src_reg = 0, \
114 .off = 0, \
115 .imm = LEN })
116
117 /* Short form of mov, dst_reg = src_reg */
118
119 #define BPF_MOV64_REG(DST, SRC) \
120 ((struct bpf_insn) { \
121 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
122 .dst_reg = DST, \
123 .src_reg = SRC, \
124 .off = 0, \
125 .imm = 0 })
126
127 #define BPF_MOV32_REG(DST, SRC) \
128 ((struct bpf_insn) { \
129 .code = BPF_ALU | BPF_MOV | BPF_X, \
130 .dst_reg = DST, \
131 .src_reg = SRC, \
132 .off = 0, \
133 .imm = 0 })
134
135 /* Short form of mov, dst_reg = imm32 */
136
137 #define BPF_MOV64_IMM(DST, IMM) \
138 ((struct bpf_insn) { \
139 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
140 .dst_reg = DST, \
141 .src_reg = 0, \
142 .off = 0, \
143 .imm = IMM })
144
145 #define BPF_MOV32_IMM(DST, IMM) \
146 ((struct bpf_insn) { \
147 .code = BPF_ALU | BPF_MOV | BPF_K, \
148 .dst_reg = DST, \
149 .src_reg = 0, \
150 .off = 0, \
151 .imm = IMM })
152
153 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
154 #define BPF_LD_IMM64(DST, IMM) \
155 BPF_LD_IMM64_RAW(DST, 0, IMM)
156
157 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
158 ((struct bpf_insn) { \
159 .code = BPF_LD | BPF_DW | BPF_IMM, \
160 .dst_reg = DST, \
161 .src_reg = SRC, \
162 .off = 0, \
163 .imm = (__u32) (IMM) }), \
164 ((struct bpf_insn) { \
165 .code = 0, /* zero is reserved opcode */ \
166 .dst_reg = 0, \
167 .src_reg = 0, \
168 .off = 0, \
169 .imm = ((__u64) (IMM)) >> 32 })
170
171 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
172 #define BPF_LD_MAP_FD(DST, MAP_FD) \
173 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
174
175 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
176
177 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
178 ((struct bpf_insn) { \
179 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
180 .dst_reg = DST, \
181 .src_reg = SRC, \
182 .off = 0, \
183 .imm = IMM })
184
185 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
186 ((struct bpf_insn) { \
187 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
188 .dst_reg = DST, \
189 .src_reg = SRC, \
190 .off = 0, \
191 .imm = IMM })
192
193 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
194
195 #define BPF_LD_ABS(SIZE, IMM) \
196 ((struct bpf_insn) { \
197 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
198 .dst_reg = 0, \
199 .src_reg = 0, \
200 .off = 0, \
201 .imm = IMM })
202
203 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
204
205 #define BPF_LD_IND(SIZE, SRC, IMM) \
206 ((struct bpf_insn) { \
207 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
208 .dst_reg = 0, \
209 .src_reg = SRC, \
210 .off = 0, \
211 .imm = IMM })
212
213 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
214
215 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
216 ((struct bpf_insn) { \
217 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
218 .dst_reg = DST, \
219 .src_reg = SRC, \
220 .off = OFF, \
221 .imm = 0 })
222
223 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
224
225 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
226 ((struct bpf_insn) { \
227 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
228 .dst_reg = DST, \
229 .src_reg = SRC, \
230 .off = OFF, \
231 .imm = 0 })
232
233 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
234
235 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
236 ((struct bpf_insn) { \
237 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
238 .dst_reg = DST, \
239 .src_reg = SRC, \
240 .off = OFF, \
241 .imm = 0 })
242
243 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
244
245 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
246 ((struct bpf_insn) { \
247 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
248 .dst_reg = DST, \
249 .src_reg = 0, \
250 .off = OFF, \
251 .imm = IMM })
252
253 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
254
255 #define BPF_JMP_REG(OP, DST, SRC, OFF) \
256 ((struct bpf_insn) { \
257 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
258 .dst_reg = DST, \
259 .src_reg = SRC, \
260 .off = OFF, \
261 .imm = 0 })
262
263 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
264
265 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \
266 ((struct bpf_insn) { \
267 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
268 .dst_reg = DST, \
269 .src_reg = 0, \
270 .off = OFF, \
271 .imm = IMM })
272
273 /* Unconditional jumps, goto pc + off16 */
274
275 #define BPF_JMP_A(OFF) \
276 ((struct bpf_insn) { \
277 .code = BPF_JMP | BPF_JA, \
278 .dst_reg = 0, \
279 .src_reg = 0, \
280 .off = OFF, \
281 .imm = 0 })
282
283 /* Function call */
284
285 #define BPF_EMIT_CALL(FUNC) \
286 ((struct bpf_insn) { \
287 .code = BPF_JMP | BPF_CALL, \
288 .dst_reg = 0, \
289 .src_reg = 0, \
290 .off = 0, \
291 .imm = ((FUNC) - __bpf_call_base) })
292
293 /* Raw code statement block */
294
295 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
296 ((struct bpf_insn) { \
297 .code = CODE, \
298 .dst_reg = DST, \
299 .src_reg = SRC, \
300 .off = OFF, \
301 .imm = IMM })
302
303 /* Program exit */
304
305 #define BPF_EXIT_INSN() \
306 ((struct bpf_insn) { \
307 .code = BPF_JMP | BPF_EXIT, \
308 .dst_reg = 0, \
309 .src_reg = 0, \
310 .off = 0, \
311 .imm = 0 })
312
313 /* Internal classic blocks for direct assignment */
314
315 #define __BPF_STMT(CODE, K) \
316 ((struct sock_filter) BPF_STMT(CODE, K))
317
318 #define __BPF_JUMP(CODE, K, JT, JF) \
319 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
320
321 #define bytes_to_bpf_size(bytes) \
322 ({ \
323 int bpf_size = -EINVAL; \
324 \
325 if (bytes == sizeof(u8)) \
326 bpf_size = BPF_B; \
327 else if (bytes == sizeof(u16)) \
328 bpf_size = BPF_H; \
329 else if (bytes == sizeof(u32)) \
330 bpf_size = BPF_W; \
331 else if (bytes == sizeof(u64)) \
332 bpf_size = BPF_DW; \
333 \
334 bpf_size; \
335 })
336
337 #define bpf_size_to_bytes(bpf_size) \
338 ({ \
339 int bytes = -EINVAL; \
340 \
341 if (bpf_size == BPF_B) \
342 bytes = sizeof(u8); \
343 else if (bpf_size == BPF_H) \
344 bytes = sizeof(u16); \
345 else if (bpf_size == BPF_W) \
346 bytes = sizeof(u32); \
347 else if (bpf_size == BPF_DW) \
348 bytes = sizeof(u64); \
349 \
350 bytes; \
351 })
352
353 #define BPF_SIZEOF(type) \
354 ({ \
355 const int __size = bytes_to_bpf_size(sizeof(type)); \
356 BUILD_BUG_ON(__size < 0); \
357 __size; \
358 })
359
360 #define BPF_FIELD_SIZEOF(type, field) \
361 ({ \
362 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
363 BUILD_BUG_ON(__size < 0); \
364 __size; \
365 })
366
367 #define BPF_LDST_BYTES(insn) \
368 ({ \
369 const int __size = bpf_size_to_bytes(BPF_SIZE(insn->code)); \
370 WARN_ON(__size < 0); \
371 __size; \
372 })
373
374 #define __BPF_MAP_0(m, v, ...) v
375 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
376 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
377 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
378 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
379 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
380
381 #define __BPF_REG_0(...) __BPF_PAD(5)
382 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
383 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
384 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
385 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
386 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
387
388 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
389 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
390
391 #define __BPF_CAST(t, a) \
392 (__force t) \
393 (__force \
394 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \
395 (unsigned long)0, (t)0))) a
396 #define __BPF_V void
397 #define __BPF_N
398
399 #define __BPF_DECL_ARGS(t, a) t a
400 #define __BPF_DECL_REGS(t, a) u64 a
401
402 #define __BPF_PAD(n) \
403 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \
404 u64, __ur_3, u64, __ur_4, u64, __ur_5)
405
406 #define BPF_CALL_x(x, name, ...) \
407 static __always_inline \
408 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
409 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \
410 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \
411 { \
412 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
413 } \
414 static __always_inline \
415 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
416
417 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__)
418 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__)
419 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__)
420 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__)
421 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__)
422 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__)
423
424 #define bpf_ctx_range(TYPE, MEMBER) \
425 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
426 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \
427 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
428
429 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \
430 ({ \
431 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \
432 *(PTR_SIZE) = (SIZE); \
433 offsetof(TYPE, MEMBER); \
434 })
435
436 #ifdef CONFIG_COMPAT
437 /* A struct sock_filter is architecture independent. */
438 struct compat_sock_fprog {
439 u16 len;
440 compat_uptr_t filter; /* struct sock_filter * */
441 };
442 #endif
443
444 struct sock_fprog_kern {
445 u16 len;
446 struct sock_filter *filter;
447 };
448
449 struct bpf_binary_header {
450 unsigned int pages;
451 u8 image[];
452 };
453
454 struct bpf_prog {
455 u16 pages; /* Number of allocated pages */
456 kmemcheck_bitfield_begin(meta);
457 u16 jited:1, /* Is our filter JIT'ed? */
458 locked:1, /* Program image locked? */
459 gpl_compatible:1, /* Is filter GPL compatible? */
460 cb_access:1, /* Is control block accessed? */
461 dst_needed:1; /* Do we need dst entry? */
462 kmemcheck_bitfield_end(meta);
463 enum bpf_prog_type type; /* Type of BPF program */
464 u32 len; /* Number of filter blocks */
465 u32 jited_len; /* Size of jited insns in bytes */
466 u8 tag[BPF_TAG_SIZE];
467 struct bpf_prog_aux *aux; /* Auxiliary fields */
468 struct sock_fprog_kern *orig_prog; /* Original BPF program */
469 unsigned int (*bpf_func)(const void *ctx,
470 const struct bpf_insn *insn);
471 /* Instructions for interpreter */
472 union {
473 struct sock_filter insns[0];
474 struct bpf_insn insnsi[0];
475 };
476 };
477
478 struct sk_filter {
479 refcount_t refcnt;
480 struct rcu_head rcu;
481 struct bpf_prog *prog;
482 };
483
484 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
485
486 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
487
488 struct bpf_skb_data_end {
489 struct qdisc_skb_cb qdisc_cb;
490 void *data_end;
491 };
492
493 struct xdp_buff {
494 void *data;
495 void *data_end;
496 void *data_hard_start;
497 };
498
499 /* compute the linear packet data range [data, data_end) which
500 * will be accessed by cls_bpf, act_bpf and lwt programs
501 */
502 static inline void bpf_compute_data_end(struct sk_buff *skb)
503 {
504 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
505
506 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
507 cb->data_end = skb->data + skb_headlen(skb);
508 }
509
510 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
511 {
512 /* eBPF programs may read/write skb->cb[] area to transfer meta
513 * data between tail calls. Since this also needs to work with
514 * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
515 *
516 * In some socket filter cases, the cb unfortunately needs to be
517 * saved/restored so that protocol specific skb->cb[] data won't
518 * be lost. In any case, due to unpriviledged eBPF programs
519 * attached to sockets, we need to clear the bpf_skb_cb() area
520 * to not leak previous contents to user space.
521 */
522 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
523 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
524 FIELD_SIZEOF(struct qdisc_skb_cb, data));
525
526 return qdisc_skb_cb(skb)->data;
527 }
528
529 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
530 struct sk_buff *skb)
531 {
532 u8 *cb_data = bpf_skb_cb(skb);
533 u8 cb_saved[BPF_SKB_CB_LEN];
534 u32 res;
535
536 if (unlikely(prog->cb_access)) {
537 memcpy(cb_saved, cb_data, sizeof(cb_saved));
538 memset(cb_data, 0, sizeof(cb_saved));
539 }
540
541 res = BPF_PROG_RUN(prog, skb);
542
543 if (unlikely(prog->cb_access))
544 memcpy(cb_data, cb_saved, sizeof(cb_saved));
545
546 return res;
547 }
548
549 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
550 struct sk_buff *skb)
551 {
552 u8 *cb_data = bpf_skb_cb(skb);
553
554 if (unlikely(prog->cb_access))
555 memset(cb_data, 0, BPF_SKB_CB_LEN);
556
557 return BPF_PROG_RUN(prog, skb);
558 }
559
560 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
561 struct xdp_buff *xdp)
562 {
563 /* Caller needs to hold rcu_read_lock() (!), otherwise program
564 * can be released while still running, or map elements could be
565 * freed early while still having concurrent users. XDP fastpath
566 * already takes rcu_read_lock() when fetching the program, so
567 * it's not necessary here anymore.
568 */
569 return BPF_PROG_RUN(prog, xdp);
570 }
571
572 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
573 {
574 return prog->len * sizeof(struct bpf_insn);
575 }
576
577 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
578 {
579 return round_up(bpf_prog_insn_size(prog) +
580 sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
581 }
582
583 static inline unsigned int bpf_prog_size(unsigned int proglen)
584 {
585 return max(sizeof(struct bpf_prog),
586 offsetof(struct bpf_prog, insns[proglen]));
587 }
588
589 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
590 {
591 /* When classic BPF programs have been loaded and the arch
592 * does not have a classic BPF JIT (anymore), they have been
593 * converted via bpf_migrate_filter() to eBPF and thus always
594 * have an unspec program type.
595 */
596 return prog->type == BPF_PROG_TYPE_UNSPEC;
597 }
598
599 static inline bool
600 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default)
601 {
602 bool off_ok;
603 #ifdef __LITTLE_ENDIAN
604 off_ok = (off & (size_default - 1)) == 0;
605 #else
606 off_ok = (off & (size_default - 1)) + size == size_default;
607 #endif
608 return off_ok && size <= size_default && (size & (size - 1)) == 0;
609 }
610
611 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
612
613 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
614 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
615 {
616 fp->locked = 1;
617 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
618 }
619
620 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
621 {
622 if (fp->locked) {
623 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
624 /* In case set_memory_rw() fails, we want to be the first
625 * to crash here instead of some random place later on.
626 */
627 fp->locked = 0;
628 }
629 }
630
631 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
632 {
633 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
634 }
635
636 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
637 {
638 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
639 }
640 #else
641 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
642 {
643 }
644
645 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
646 {
647 }
648
649 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
650 {
651 }
652
653 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
654 {
655 }
656 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
657
658 static inline struct bpf_binary_header *
659 bpf_jit_binary_hdr(const struct bpf_prog *fp)
660 {
661 unsigned long real_start = (unsigned long)fp->bpf_func;
662 unsigned long addr = real_start & PAGE_MASK;
663
664 return (void *)addr;
665 }
666
667 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
668 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
669 {
670 return sk_filter_trim_cap(sk, skb, 1);
671 }
672
673 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
674 void bpf_prog_free(struct bpf_prog *fp);
675
676 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
677 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
678 gfp_t gfp_extra_flags);
679 void __bpf_prog_free(struct bpf_prog *fp);
680
681 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
682 {
683 bpf_prog_unlock_ro(fp);
684 __bpf_prog_free(fp);
685 }
686
687 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
688 unsigned int flen);
689
690 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
691 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
692 bpf_aux_classic_check_t trans, bool save_orig);
693 void bpf_prog_destroy(struct bpf_prog *fp);
694
695 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
696 int sk_attach_bpf(u32 ufd, struct sock *sk);
697 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
698 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
699 int sk_detach_filter(struct sock *sk);
700 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
701 unsigned int len);
702
703 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
704 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
705
706 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
707
708 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
709 void bpf_jit_compile(struct bpf_prog *prog);
710 bool bpf_helper_changes_pkt_data(void *func);
711
712 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
713 const struct bpf_insn *patch, u32 len);
714 void bpf_warn_invalid_xdp_action(u32 act);
715
716 #ifdef CONFIG_BPF_JIT
717 extern int bpf_jit_enable;
718 extern int bpf_jit_harden;
719 extern int bpf_jit_kallsyms;
720
721 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
722
723 struct bpf_binary_header *
724 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
725 unsigned int alignment,
726 bpf_jit_fill_hole_t bpf_fill_ill_insns);
727 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
728
729 void bpf_jit_free(struct bpf_prog *fp);
730
731 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
732 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
733
734 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
735 u32 pass, void *image)
736 {
737 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
738 proglen, pass, image, current->comm, task_pid_nr(current));
739
740 if (image)
741 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
742 16, 1, image, proglen, false);
743 }
744
745 static inline bool bpf_jit_is_ebpf(void)
746 {
747 # ifdef CONFIG_HAVE_EBPF_JIT
748 return true;
749 # else
750 return false;
751 # endif
752 }
753
754 static inline bool ebpf_jit_enabled(void)
755 {
756 return bpf_jit_enable && bpf_jit_is_ebpf();
757 }
758
759 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
760 {
761 return fp->jited && bpf_jit_is_ebpf();
762 }
763
764 static inline bool bpf_jit_blinding_enabled(void)
765 {
766 /* These are the prerequisites, should someone ever have the
767 * idea to call blinding outside of them, we make sure to
768 * bail out.
769 */
770 if (!bpf_jit_is_ebpf())
771 return false;
772 if (!bpf_jit_enable)
773 return false;
774 if (!bpf_jit_harden)
775 return false;
776 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
777 return false;
778
779 return true;
780 }
781
782 static inline bool bpf_jit_kallsyms_enabled(void)
783 {
784 /* There are a couple of corner cases where kallsyms should
785 * not be enabled f.e. on hardening.
786 */
787 if (bpf_jit_harden)
788 return false;
789 if (!bpf_jit_kallsyms)
790 return false;
791 if (bpf_jit_kallsyms == 1)
792 return true;
793
794 return false;
795 }
796
797 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
798 unsigned long *off, char *sym);
799 bool is_bpf_text_address(unsigned long addr);
800 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
801 char *sym);
802
803 static inline const char *
804 bpf_address_lookup(unsigned long addr, unsigned long *size,
805 unsigned long *off, char **modname, char *sym)
806 {
807 const char *ret = __bpf_address_lookup(addr, size, off, sym);
808
809 if (ret && modname)
810 *modname = NULL;
811 return ret;
812 }
813
814 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
815 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
816
817 #else /* CONFIG_BPF_JIT */
818
819 static inline bool ebpf_jit_enabled(void)
820 {
821 return false;
822 }
823
824 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
825 {
826 return false;
827 }
828
829 static inline void bpf_jit_free(struct bpf_prog *fp)
830 {
831 bpf_prog_unlock_free(fp);
832 }
833
834 static inline bool bpf_jit_kallsyms_enabled(void)
835 {
836 return false;
837 }
838
839 static inline const char *
840 __bpf_address_lookup(unsigned long addr, unsigned long *size,
841 unsigned long *off, char *sym)
842 {
843 return NULL;
844 }
845
846 static inline bool is_bpf_text_address(unsigned long addr)
847 {
848 return false;
849 }
850
851 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
852 char *type, char *sym)
853 {
854 return -ERANGE;
855 }
856
857 static inline const char *
858 bpf_address_lookup(unsigned long addr, unsigned long *size,
859 unsigned long *off, char **modname, char *sym)
860 {
861 return NULL;
862 }
863
864 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
865 {
866 }
867
868 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
869 {
870 }
871 #endif /* CONFIG_BPF_JIT */
872
873 #define BPF_ANC BIT(15)
874
875 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
876 {
877 switch (first->code) {
878 case BPF_RET | BPF_K:
879 case BPF_LD | BPF_W | BPF_LEN:
880 return false;
881
882 case BPF_LD | BPF_W | BPF_ABS:
883 case BPF_LD | BPF_H | BPF_ABS:
884 case BPF_LD | BPF_B | BPF_ABS:
885 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
886 return true;
887 return false;
888
889 default:
890 return true;
891 }
892 }
893
894 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
895 {
896 BUG_ON(ftest->code & BPF_ANC);
897
898 switch (ftest->code) {
899 case BPF_LD | BPF_W | BPF_ABS:
900 case BPF_LD | BPF_H | BPF_ABS:
901 case BPF_LD | BPF_B | BPF_ABS:
902 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
903 return BPF_ANC | SKF_AD_##CODE
904 switch (ftest->k) {
905 BPF_ANCILLARY(PROTOCOL);
906 BPF_ANCILLARY(PKTTYPE);
907 BPF_ANCILLARY(IFINDEX);
908 BPF_ANCILLARY(NLATTR);
909 BPF_ANCILLARY(NLATTR_NEST);
910 BPF_ANCILLARY(MARK);
911 BPF_ANCILLARY(QUEUE);
912 BPF_ANCILLARY(HATYPE);
913 BPF_ANCILLARY(RXHASH);
914 BPF_ANCILLARY(CPU);
915 BPF_ANCILLARY(ALU_XOR_X);
916 BPF_ANCILLARY(VLAN_TAG);
917 BPF_ANCILLARY(VLAN_TAG_PRESENT);
918 BPF_ANCILLARY(PAY_OFFSET);
919 BPF_ANCILLARY(RANDOM);
920 BPF_ANCILLARY(VLAN_TPID);
921 }
922 /* Fallthrough. */
923 default:
924 return ftest->code;
925 }
926 }
927
928 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
929 int k, unsigned int size);
930
931 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
932 unsigned int size, void *buffer)
933 {
934 if (k >= 0)
935 return skb_header_pointer(skb, k, size, buffer);
936
937 return bpf_internal_load_pointer_neg_helper(skb, k, size);
938 }
939
940 static inline int bpf_tell_extensions(void)
941 {
942 return SKF_AD_MAX;
943 }
944
945 struct bpf_sock_ops_kern {
946 struct sock *sk;
947 u32 op;
948 union {
949 u32 reply;
950 u32 replylong[4];
951 };
952 };
953
954 #endif /* __LINUX_FILTER_H__ */
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