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TOMOYO Linux Cross Reference
Linux/include/linux/filter.h

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

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