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

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Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 #include <linux/if_vlan.h>
 23 
 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 struct xdp_rxq_info;
 34 struct xdp_buff;
 35 
 36 /* ArgX, context and stack frame pointer register positions. Note,
 37  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
 38  * calls in BPF_CALL instruction.
 39  */
 40 #define BPF_REG_ARG1    BPF_REG_1
 41 #define BPF_REG_ARG2    BPF_REG_2
 42 #define BPF_REG_ARG3    BPF_REG_3
 43 #define BPF_REG_ARG4    BPF_REG_4
 44 #define BPF_REG_ARG5    BPF_REG_5
 45 #define BPF_REG_CTX     BPF_REG_6
 46 #define BPF_REG_FP      BPF_REG_10
 47 
 48 /* Additional register mappings for converted user programs. */
 49 #define BPF_REG_A       BPF_REG_0
 50 #define BPF_REG_X       BPF_REG_7
 51 #define BPF_REG_TMP     BPF_REG_2       /* scratch reg */
 52 #define BPF_REG_D       BPF_REG_8       /* data, callee-saved */
 53 #define BPF_REG_H       BPF_REG_9       /* hlen, callee-saved */
 54 
 55 /* Kernel hidden auxiliary/helper register for hardening step.
 56  * Only used by eBPF JITs. It's nothing more than a temporary
 57  * register that JITs use internally, only that here it's part
 58  * of eBPF instructions that have been rewritten for blinding
 59  * constants. See JIT pre-step in bpf_jit_blind_constants().
 60  */
 61 #define BPF_REG_AX              MAX_BPF_REG
 62 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
 63 
 64 /* unused opcode to mark special call to bpf_tail_call() helper */
 65 #define BPF_TAIL_CALL   0xf0
 66 
 67 /* unused opcode to mark call to interpreter with arguments */
 68 #define BPF_CALL_ARGS   0xe0
 69 
 70 /* As per nm, we expose JITed images as text (code) section for
 71  * kallsyms. That way, tools like perf can find it to match
 72  * addresses.
 73  */
 74 #define BPF_SYM_ELF_TYPE        't'
 75 
 76 /* BPF program can access up to 512 bytes of stack space. */
 77 #define MAX_BPF_STACK   512
 78 
 79 /* Helper macros for filter block array initializers. */
 80 
 81 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
 82 
 83 #define BPF_ALU64_REG(OP, DST, SRC)                             \
 84         ((struct bpf_insn) {                                    \
 85                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
 86                 .dst_reg = DST,                                 \
 87                 .src_reg = SRC,                                 \
 88                 .off   = 0,                                     \
 89                 .imm   = 0 })
 90 
 91 #define BPF_ALU32_REG(OP, DST, SRC)                             \
 92         ((struct bpf_insn) {                                    \
 93                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
 94                 .dst_reg = DST,                                 \
 95                 .src_reg = SRC,                                 \
 96                 .off   = 0,                                     \
 97                 .imm   = 0 })
 98 
 99 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
100 
101 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
102         ((struct bpf_insn) {                                    \
103                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
104                 .dst_reg = DST,                                 \
105                 .src_reg = 0,                                   \
106                 .off   = 0,                                     \
107                 .imm   = IMM })
108 
109 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
110         ((struct bpf_insn) {                                    \
111                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
112                 .dst_reg = DST,                                 \
113                 .src_reg = 0,                                   \
114                 .off   = 0,                                     \
115                 .imm   = IMM })
116 
117 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
118 
119 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
120         ((struct bpf_insn) {                                    \
121                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
122                 .dst_reg = DST,                                 \
123                 .src_reg = 0,                                   \
124                 .off   = 0,                                     \
125                 .imm   = LEN })
126 
127 /* Short form of mov, dst_reg = src_reg */
128 
129 #define BPF_MOV64_REG(DST, SRC)                                 \
130         ((struct bpf_insn) {                                    \
131                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
132                 .dst_reg = DST,                                 \
133                 .src_reg = SRC,                                 \
134                 .off   = 0,                                     \
135                 .imm   = 0 })
136 
137 #define BPF_MOV32_REG(DST, SRC)                                 \
138         ((struct bpf_insn) {                                    \
139                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
140                 .dst_reg = DST,                                 \
141                 .src_reg = SRC,                                 \
142                 .off   = 0,                                     \
143                 .imm   = 0 })
144 
145 /* Short form of mov, dst_reg = imm32 */
146 
147 #define BPF_MOV64_IMM(DST, IMM)                                 \
148         ((struct bpf_insn) {                                    \
149                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
150                 .dst_reg = DST,                                 \
151                 .src_reg = 0,                                   \
152                 .off   = 0,                                     \
153                 .imm   = IMM })
154 
155 #define BPF_MOV32_IMM(DST, IMM)                                 \
156         ((struct bpf_insn) {                                    \
157                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
158                 .dst_reg = DST,                                 \
159                 .src_reg = 0,                                   \
160                 .off   = 0,                                     \
161                 .imm   = IMM })
162 
163 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
164 #define BPF_LD_IMM64(DST, IMM)                                  \
165         BPF_LD_IMM64_RAW(DST, 0, IMM)
166 
167 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
168         ((struct bpf_insn) {                                    \
169                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
170                 .dst_reg = DST,                                 \
171                 .src_reg = SRC,                                 \
172                 .off   = 0,                                     \
173                 .imm   = (__u32) (IMM) }),                      \
174         ((struct bpf_insn) {                                    \
175                 .code  = 0, /* zero is reserved opcode */       \
176                 .dst_reg = 0,                                   \
177                 .src_reg = 0,                                   \
178                 .off   = 0,                                     \
179                 .imm   = ((__u64) (IMM)) >> 32 })
180 
181 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
182 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
183         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
184 
185 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
186 
187 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
188         ((struct bpf_insn) {                                    \
189                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
190                 .dst_reg = DST,                                 \
191                 .src_reg = SRC,                                 \
192                 .off   = 0,                                     \
193                 .imm   = IMM })
194 
195 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
196         ((struct bpf_insn) {                                    \
197                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
198                 .dst_reg = DST,                                 \
199                 .src_reg = SRC,                                 \
200                 .off   = 0,                                     \
201                 .imm   = IMM })
202 
203 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
204 
205 #define BPF_LD_ABS(SIZE, IMM)                                   \
206         ((struct bpf_insn) {                                    \
207                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
208                 .dst_reg = 0,                                   \
209                 .src_reg = 0,                                   \
210                 .off   = 0,                                     \
211                 .imm   = IMM })
212 
213 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
214 
215 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
216         ((struct bpf_insn) {                                    \
217                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
218                 .dst_reg = 0,                                   \
219                 .src_reg = SRC,                                 \
220                 .off   = 0,                                     \
221                 .imm   = IMM })
222 
223 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
224 
225 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
226         ((struct bpf_insn) {                                    \
227                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
228                 .dst_reg = DST,                                 \
229                 .src_reg = SRC,                                 \
230                 .off   = OFF,                                   \
231                 .imm   = 0 })
232 
233 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
234 
235 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
236         ((struct bpf_insn) {                                    \
237                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
238                 .dst_reg = DST,                                 \
239                 .src_reg = SRC,                                 \
240                 .off   = OFF,                                   \
241                 .imm   = 0 })
242 
243 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
244 
245 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
246         ((struct bpf_insn) {                                    \
247                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
248                 .dst_reg = DST,                                 \
249                 .src_reg = SRC,                                 \
250                 .off   = OFF,                                   \
251                 .imm   = 0 })
252 
253 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
254 
255 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
256         ((struct bpf_insn) {                                    \
257                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
258                 .dst_reg = DST,                                 \
259                 .src_reg = 0,                                   \
260                 .off   = OFF,                                   \
261                 .imm   = IMM })
262 
263 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
264 
265 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
266         ((struct bpf_insn) {                                    \
267                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
268                 .dst_reg = DST,                                 \
269                 .src_reg = SRC,                                 \
270                 .off   = OFF,                                   \
271                 .imm   = 0 })
272 
273 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
274 
275 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
276         ((struct bpf_insn) {                                    \
277                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
278                 .dst_reg = DST,                                 \
279                 .src_reg = 0,                                   \
280                 .off   = OFF,                                   \
281                 .imm   = IMM })
282 
283 /* Unconditional jumps, goto pc + off16 */
284 
285 #define BPF_JMP_A(OFF)                                          \
286         ((struct bpf_insn) {                                    \
287                 .code  = BPF_JMP | BPF_JA,                      \
288                 .dst_reg = 0,                                   \
289                 .src_reg = 0,                                   \
290                 .off   = OFF,                                   \
291                 .imm   = 0 })
292 
293 /* Relative call */
294 
295 #define BPF_CALL_REL(TGT)                                       \
296         ((struct bpf_insn) {                                    \
297                 .code  = BPF_JMP | BPF_CALL,                    \
298                 .dst_reg = 0,                                   \
299                 .src_reg = BPF_PSEUDO_CALL,                     \
300                 .off   = 0,                                     \
301                 .imm   = TGT })
302 
303 /* Function call */
304 
305 #define BPF_CAST_CALL(x)                                        \
306                 ((u64 (*)(u64, u64, u64, u64, u64))(x))
307 
308 #define BPF_EMIT_CALL(FUNC)                                     \
309         ((struct bpf_insn) {                                    \
310                 .code  = BPF_JMP | BPF_CALL,                    \
311                 .dst_reg = 0,                                   \
312                 .src_reg = 0,                                   \
313                 .off   = 0,                                     \
314                 .imm   = ((FUNC) - __bpf_call_base) })
315 
316 /* Raw code statement block */
317 
318 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
319         ((struct bpf_insn) {                                    \
320                 .code  = CODE,                                  \
321                 .dst_reg = DST,                                 \
322                 .src_reg = SRC,                                 \
323                 .off   = OFF,                                   \
324                 .imm   = IMM })
325 
326 /* Program exit */
327 
328 #define BPF_EXIT_INSN()                                         \
329         ((struct bpf_insn) {                                    \
330                 .code  = BPF_JMP | BPF_EXIT,                    \
331                 .dst_reg = 0,                                   \
332                 .src_reg = 0,                                   \
333                 .off   = 0,                                     \
334                 .imm   = 0 })
335 
336 /* Internal classic blocks for direct assignment */
337 
338 #define __BPF_STMT(CODE, K)                                     \
339         ((struct sock_filter) BPF_STMT(CODE, K))
340 
341 #define __BPF_JUMP(CODE, K, JT, JF)                             \
342         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
343 
344 #define bytes_to_bpf_size(bytes)                                \
345 ({                                                              \
346         int bpf_size = -EINVAL;                                 \
347                                                                 \
348         if (bytes == sizeof(u8))                                \
349                 bpf_size = BPF_B;                               \
350         else if (bytes == sizeof(u16))                          \
351                 bpf_size = BPF_H;                               \
352         else if (bytes == sizeof(u32))                          \
353                 bpf_size = BPF_W;                               \
354         else if (bytes == sizeof(u64))                          \
355                 bpf_size = BPF_DW;                              \
356                                                                 \
357         bpf_size;                                               \
358 })
359 
360 #define bpf_size_to_bytes(bpf_size)                             \
361 ({                                                              \
362         int bytes = -EINVAL;                                    \
363                                                                 \
364         if (bpf_size == BPF_B)                                  \
365                 bytes = sizeof(u8);                             \
366         else if (bpf_size == BPF_H)                             \
367                 bytes = sizeof(u16);                            \
368         else if (bpf_size == BPF_W)                             \
369                 bytes = sizeof(u32);                            \
370         else if (bpf_size == BPF_DW)                            \
371                 bytes = sizeof(u64);                            \
372                                                                 \
373         bytes;                                                  \
374 })
375 
376 #define BPF_SIZEOF(type)                                        \
377         ({                                                      \
378                 const int __size = bytes_to_bpf_size(sizeof(type)); \
379                 BUILD_BUG_ON(__size < 0);                       \
380                 __size;                                         \
381         })
382 
383 #define BPF_FIELD_SIZEOF(type, field)                           \
384         ({                                                      \
385                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
386                 BUILD_BUG_ON(__size < 0);                       \
387                 __size;                                         \
388         })
389 
390 #define BPF_LDST_BYTES(insn)                                    \
391         ({                                                      \
392                 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
393                 WARN_ON(__size < 0);                            \
394                 __size;                                         \
395         })
396 
397 #define __BPF_MAP_0(m, v, ...) v
398 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
399 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
400 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
401 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
402 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
403 
404 #define __BPF_REG_0(...) __BPF_PAD(5)
405 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
406 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
407 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
408 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
409 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
410 
411 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
412 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
413 
414 #define __BPF_CAST(t, a)                                                       \
415         (__force t)                                                            \
416         (__force                                                               \
417          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
418                                       (unsigned long)0, (t)0))) a
419 #define __BPF_V void
420 #define __BPF_N
421 
422 #define __BPF_DECL_ARGS(t, a) t   a
423 #define __BPF_DECL_REGS(t, a) u64 a
424 
425 #define __BPF_PAD(n)                                                           \
426         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
427                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
428 
429 #define BPF_CALL_x(x, name, ...)                                               \
430         static __always_inline                                                 \
431         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
432         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
433         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
434         {                                                                      \
435                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
436         }                                                                      \
437         static __always_inline                                                 \
438         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
439 
440 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
441 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
442 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
443 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
444 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
445 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
446 
447 #define bpf_ctx_range(TYPE, MEMBER)                                             \
448         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
449 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)                              \
450         offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
451 
452 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)                            \
453         ({                                                                      \
454                 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE));             \
455                 *(PTR_SIZE) = (SIZE);                                           \
456                 offsetof(TYPE, MEMBER);                                         \
457         })
458 
459 #ifdef CONFIG_COMPAT
460 /* A struct sock_filter is architecture independent. */
461 struct compat_sock_fprog {
462         u16             len;
463         compat_uptr_t   filter; /* struct sock_filter * */
464 };
465 #endif
466 
467 struct sock_fprog_kern {
468         u16                     len;
469         struct sock_filter      *filter;
470 };
471 
472 struct bpf_binary_header {
473         u32 pages;
474         /* Some arches need word alignment for their instructions */
475         u8 image[] __aligned(4);
476 };
477 
478 struct bpf_prog {
479         u16                     pages;          /* Number of allocated pages */
480         u16                     jited:1,        /* Is our filter JIT'ed? */
481                                 jit_requested:1,/* archs need to JIT the prog */
482                                 undo_set_mem:1, /* Passed set_memory_ro() checkpoint */
483                                 gpl_compatible:1, /* Is filter GPL compatible? */
484                                 cb_access:1,    /* Is control block accessed? */
485                                 dst_needed:1,   /* Do we need dst entry? */
486                                 blinded:1,      /* Was blinded */
487                                 is_func:1,      /* program is a bpf function */
488                                 kprobe_override:1, /* Do we override a kprobe? */
489                                 has_callchain_buf:1; /* callchain buffer allocated? */
490         enum bpf_prog_type      type;           /* Type of BPF program */
491         enum bpf_attach_type    expected_attach_type; /* For some prog types */
492         u32                     len;            /* Number of filter blocks */
493         u32                     jited_len;      /* Size of jited insns in bytes */
494         u8                      tag[BPF_TAG_SIZE];
495         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
496         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
497         unsigned int            (*bpf_func)(const void *ctx,
498                                             const struct bpf_insn *insn);
499         /* Instructions for interpreter */
500         union {
501                 struct sock_filter      insns[0];
502                 struct bpf_insn         insnsi[0];
503         };
504 };
505 
506 struct sk_filter {
507         refcount_t      refcnt;
508         struct rcu_head rcu;
509         struct bpf_prog *prog;
510 };
511 
512 #define BPF_PROG_RUN(filter, ctx)  (*(filter)->bpf_func)(ctx, (filter)->insnsi)
513 
514 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
515 
516 struct bpf_skb_data_end {
517         struct qdisc_skb_cb qdisc_cb;
518         void *data_meta;
519         void *data_end;
520 };
521 
522 struct sk_msg_buff {
523         void *data;
524         void *data_end;
525         __u32 apply_bytes;
526         __u32 cork_bytes;
527         int sg_copybreak;
528         int sg_start;
529         int sg_curr;
530         int sg_end;
531         struct scatterlist sg_data[MAX_SKB_FRAGS];
532         bool sg_copy[MAX_SKB_FRAGS];
533         __u32 flags;
534         struct sock *sk_redir;
535         struct sock *sk;
536         struct sk_buff *skb;
537         struct list_head list;
538 };
539 
540 /* Compute the linear packet data range [data, data_end) which
541  * will be accessed by various program types (cls_bpf, act_bpf,
542  * lwt, ...). Subsystems allowing direct data access must (!)
543  * ensure that cb[] area can be written to when BPF program is
544  * invoked (otherwise cb[] save/restore is necessary).
545  */
546 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
547 {
548         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
549 
550         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
551         cb->data_meta = skb->data - skb_metadata_len(skb);
552         cb->data_end  = skb->data + skb_headlen(skb);
553 }
554 
555 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
556 {
557         /* eBPF programs may read/write skb->cb[] area to transfer meta
558          * data between tail calls. Since this also needs to work with
559          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
560          *
561          * In some socket filter cases, the cb unfortunately needs to be
562          * saved/restored so that protocol specific skb->cb[] data won't
563          * be lost. In any case, due to unpriviledged eBPF programs
564          * attached to sockets, we need to clear the bpf_skb_cb() area
565          * to not leak previous contents to user space.
566          */
567         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
568         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
569                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
570 
571         return qdisc_skb_cb(skb)->data;
572 }
573 
574 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
575                                        struct sk_buff *skb)
576 {
577         u8 *cb_data = bpf_skb_cb(skb);
578         u8 cb_saved[BPF_SKB_CB_LEN];
579         u32 res;
580 
581         if (unlikely(prog->cb_access)) {
582                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
583                 memset(cb_data, 0, sizeof(cb_saved));
584         }
585 
586         res = BPF_PROG_RUN(prog, skb);
587 
588         if (unlikely(prog->cb_access))
589                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
590 
591         return res;
592 }
593 
594 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
595                                         struct sk_buff *skb)
596 {
597         u8 *cb_data = bpf_skb_cb(skb);
598 
599         if (unlikely(prog->cb_access))
600                 memset(cb_data, 0, BPF_SKB_CB_LEN);
601 
602         return BPF_PROG_RUN(prog, skb);
603 }
604 
605 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
606                                             struct xdp_buff *xdp)
607 {
608         /* Caller needs to hold rcu_read_lock() (!), otherwise program
609          * can be released while still running, or map elements could be
610          * freed early while still having concurrent users. XDP fastpath
611          * already takes rcu_read_lock() when fetching the program, so
612          * it's not necessary here anymore.
613          */
614         return BPF_PROG_RUN(prog, xdp);
615 }
616 
617 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
618 {
619         return prog->len * sizeof(struct bpf_insn);
620 }
621 
622 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
623 {
624         return round_up(bpf_prog_insn_size(prog) +
625                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
626 }
627 
628 static inline unsigned int bpf_prog_size(unsigned int proglen)
629 {
630         return max(sizeof(struct bpf_prog),
631                    offsetof(struct bpf_prog, insns[proglen]));
632 }
633 
634 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
635 {
636         /* When classic BPF programs have been loaded and the arch
637          * does not have a classic BPF JIT (anymore), they have been
638          * converted via bpf_migrate_filter() to eBPF and thus always
639          * have an unspec program type.
640          */
641         return prog->type == BPF_PROG_TYPE_UNSPEC;
642 }
643 
644 static inline u32 bpf_ctx_off_adjust_machine(u32 size)
645 {
646         const u32 size_machine = sizeof(unsigned long);
647 
648         if (size > size_machine && size % size_machine == 0)
649                 size = size_machine;
650 
651         return size;
652 }
653 
654 static inline bool bpf_ctx_narrow_align_ok(u32 off, u32 size_access,
655                                            u32 size_default)
656 {
657         size_default = bpf_ctx_off_adjust_machine(size_default);
658         size_access  = bpf_ctx_off_adjust_machine(size_access);
659 
660 #ifdef __LITTLE_ENDIAN
661         return (off & (size_default - 1)) == 0;
662 #else
663         return (off & (size_default - 1)) + size_access == size_default;
664 #endif
665 }
666 
667 static inline bool
668 bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
669 {
670         return bpf_ctx_narrow_align_ok(off, size, size_default) &&
671                size <= size_default && (size & (size - 1)) == 0;
672 }
673 
674 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
675 
676 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
677 {
678         fp->undo_set_mem = 1;
679         set_memory_ro((unsigned long)fp, fp->pages);
680 }
681 
682 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
683 {
684         if (fp->undo_set_mem)
685                 set_memory_rw((unsigned long)fp, fp->pages);
686 }
687 
688 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
689 {
690         set_memory_ro((unsigned long)hdr, hdr->pages);
691 }
692 
693 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
694 {
695         set_memory_rw((unsigned long)hdr, hdr->pages);
696 }
697 
698 static inline struct bpf_binary_header *
699 bpf_jit_binary_hdr(const struct bpf_prog *fp)
700 {
701         unsigned long real_start = (unsigned long)fp->bpf_func;
702         unsigned long addr = real_start & PAGE_MASK;
703 
704         return (void *)addr;
705 }
706 
707 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
708 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
709 {
710         return sk_filter_trim_cap(sk, skb, 1);
711 }
712 
713 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
714 void bpf_prog_free(struct bpf_prog *fp);
715 
716 bool bpf_opcode_in_insntable(u8 code);
717 
718 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
719 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
720                                   gfp_t gfp_extra_flags);
721 void __bpf_prog_free(struct bpf_prog *fp);
722 
723 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
724 {
725         bpf_prog_unlock_ro(fp);
726         __bpf_prog_free(fp);
727 }
728 
729 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
730                                        unsigned int flen);
731 
732 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
733 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
734                               bpf_aux_classic_check_t trans, bool save_orig);
735 void bpf_prog_destroy(struct bpf_prog *fp);
736 
737 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
738 int sk_attach_bpf(u32 ufd, struct sock *sk);
739 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
740 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
741 int sk_detach_filter(struct sock *sk);
742 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
743                   unsigned int len);
744 
745 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
746 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
747 
748 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
749 #define __bpf_call_base_args \
750         ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
751          __bpf_call_base)
752 
753 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
754 void bpf_jit_compile(struct bpf_prog *prog);
755 bool bpf_helper_changes_pkt_data(void *func);
756 
757 static inline bool bpf_dump_raw_ok(void)
758 {
759         /* Reconstruction of call-sites is dependent on kallsyms,
760          * thus make dump the same restriction.
761          */
762         return kallsyms_show_value() == 1;
763 }
764 
765 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
766                                        const struct bpf_insn *patch, u32 len);
767 
768 static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
769                                  unsigned int pktlen)
770 {
771         unsigned int len;
772 
773         if (unlikely(!(fwd->flags & IFF_UP)))
774                 return -ENETDOWN;
775 
776         len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN;
777         if (pktlen > len)
778                 return -EMSGSIZE;
779 
780         return 0;
781 }
782 
783 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
784  * same cpu context. Further for best results no more than a single map
785  * for the do_redirect/do_flush pair should be used. This limitation is
786  * because we only track one map and force a flush when the map changes.
787  * This does not appear to be a real limitation for existing software.
788  */
789 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
790                             struct xdp_buff *xdp, struct bpf_prog *prog);
791 int xdp_do_redirect(struct net_device *dev,
792                     struct xdp_buff *xdp,
793                     struct bpf_prog *prog);
794 void xdp_do_flush_map(void);
795 
796 void bpf_warn_invalid_xdp_action(u32 act);
797 
798 struct sock *do_sk_redirect_map(struct sk_buff *skb);
799 struct sock *do_msg_redirect_map(struct sk_msg_buff *md);
800 
801 #ifdef CONFIG_BPF_JIT
802 extern int bpf_jit_enable;
803 extern int bpf_jit_harden;
804 extern int bpf_jit_kallsyms;
805 
806 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
807 
808 struct bpf_binary_header *
809 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
810                      unsigned int alignment,
811                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
812 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
813 
814 void bpf_jit_free(struct bpf_prog *fp);
815 
816 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
817 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
818 
819 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
820                                 u32 pass, void *image)
821 {
822         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
823                proglen, pass, image, current->comm, task_pid_nr(current));
824 
825         if (image)
826                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
827                                16, 1, image, proglen, false);
828 }
829 
830 static inline bool bpf_jit_is_ebpf(void)
831 {
832 # ifdef CONFIG_HAVE_EBPF_JIT
833         return true;
834 # else
835         return false;
836 # endif
837 }
838 
839 static inline bool ebpf_jit_enabled(void)
840 {
841         return bpf_jit_enable && bpf_jit_is_ebpf();
842 }
843 
844 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
845 {
846         return fp->jited && bpf_jit_is_ebpf();
847 }
848 
849 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
850 {
851         /* These are the prerequisites, should someone ever have the
852          * idea to call blinding outside of them, we make sure to
853          * bail out.
854          */
855         if (!bpf_jit_is_ebpf())
856                 return false;
857         if (!prog->jit_requested)
858                 return false;
859         if (!bpf_jit_harden)
860                 return false;
861         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
862                 return false;
863 
864         return true;
865 }
866 
867 static inline bool bpf_jit_kallsyms_enabled(void)
868 {
869         /* There are a couple of corner cases where kallsyms should
870          * not be enabled f.e. on hardening.
871          */
872         if (bpf_jit_harden)
873                 return false;
874         if (!bpf_jit_kallsyms)
875                 return false;
876         if (bpf_jit_kallsyms == 1)
877                 return true;
878 
879         return false;
880 }
881 
882 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
883                                  unsigned long *off, char *sym);
884 bool is_bpf_text_address(unsigned long addr);
885 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
886                     char *sym);
887 
888 static inline const char *
889 bpf_address_lookup(unsigned long addr, unsigned long *size,
890                    unsigned long *off, char **modname, char *sym)
891 {
892         const char *ret = __bpf_address_lookup(addr, size, off, sym);
893 
894         if (ret && modname)
895                 *modname = NULL;
896         return ret;
897 }
898 
899 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
900 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
901 
902 #else /* CONFIG_BPF_JIT */
903 
904 static inline bool ebpf_jit_enabled(void)
905 {
906         return false;
907 }
908 
909 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
910 {
911         return false;
912 }
913 
914 static inline void bpf_jit_free(struct bpf_prog *fp)
915 {
916         bpf_prog_unlock_free(fp);
917 }
918 
919 static inline bool bpf_jit_kallsyms_enabled(void)
920 {
921         return false;
922 }
923 
924 static inline const char *
925 __bpf_address_lookup(unsigned long addr, unsigned long *size,
926                      unsigned long *off, char *sym)
927 {
928         return NULL;
929 }
930 
931 static inline bool is_bpf_text_address(unsigned long addr)
932 {
933         return false;
934 }
935 
936 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
937                                   char *type, char *sym)
938 {
939         return -ERANGE;
940 }
941 
942 static inline const char *
943 bpf_address_lookup(unsigned long addr, unsigned long *size,
944                    unsigned long *off, char **modname, char *sym)
945 {
946         return NULL;
947 }
948 
949 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
950 {
951 }
952 
953 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
954 {
955 }
956 #endif /* CONFIG_BPF_JIT */
957 
958 void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp);
959 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
960 
961 #define BPF_ANC         BIT(15)
962 
963 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
964 {
965         switch (first->code) {
966         case BPF_RET | BPF_K:
967         case BPF_LD | BPF_W | BPF_LEN:
968                 return false;
969 
970         case BPF_LD | BPF_W | BPF_ABS:
971         case BPF_LD | BPF_H | BPF_ABS:
972         case BPF_LD | BPF_B | BPF_ABS:
973                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
974                         return true;
975                 return false;
976 
977         default:
978                 return true;
979         }
980 }
981 
982 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
983 {
984         BUG_ON(ftest->code & BPF_ANC);
985 
986         switch (ftest->code) {
987         case BPF_LD | BPF_W | BPF_ABS:
988         case BPF_LD | BPF_H | BPF_ABS:
989         case BPF_LD | BPF_B | BPF_ABS:
990 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
991                                 return BPF_ANC | SKF_AD_##CODE
992                 switch (ftest->k) {
993                 BPF_ANCILLARY(PROTOCOL);
994                 BPF_ANCILLARY(PKTTYPE);
995                 BPF_ANCILLARY(IFINDEX);
996                 BPF_ANCILLARY(NLATTR);
997                 BPF_ANCILLARY(NLATTR_NEST);
998                 BPF_ANCILLARY(MARK);
999                 BPF_ANCILLARY(QUEUE);
1000                 BPF_ANCILLARY(HATYPE);
1001                 BPF_ANCILLARY(RXHASH);
1002                 BPF_ANCILLARY(CPU);
1003                 BPF_ANCILLARY(ALU_XOR_X);
1004                 BPF_ANCILLARY(VLAN_TAG);
1005                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
1006                 BPF_ANCILLARY(PAY_OFFSET);
1007                 BPF_ANCILLARY(RANDOM);
1008                 BPF_ANCILLARY(VLAN_TPID);
1009                 }
1010                 /* Fallthrough. */
1011         default:
1012                 return ftest->code;
1013         }
1014 }
1015 
1016 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
1017                                            int k, unsigned int size);
1018 
1019 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
1020                                      unsigned int size, void *buffer)
1021 {
1022         if (k >= 0)
1023                 return skb_header_pointer(skb, k, size, buffer);
1024 
1025         return bpf_internal_load_pointer_neg_helper(skb, k, size);
1026 }
1027 
1028 static inline int bpf_tell_extensions(void)
1029 {
1030         return SKF_AD_MAX;
1031 }
1032 
1033 struct bpf_sock_addr_kern {
1034         struct sock *sk;
1035         struct sockaddr *uaddr;
1036         /* Temporary "register" to make indirect stores to nested structures
1037          * defined above. We need three registers to make such a store, but
1038          * only two (src and dst) are available at convert_ctx_access time
1039          */
1040         u64 tmp_reg;
1041         void *t_ctx;    /* Attach type specific context. */
1042 };
1043 
1044 struct bpf_sock_ops_kern {
1045         struct  sock *sk;
1046         u32     op;
1047         union {
1048                 u32 args[4];
1049                 u32 reply;
1050                 u32 replylong[4];
1051         };
1052         u32     is_fullsock;
1053         u64     temp;                   /* temp and everything after is not
1054                                          * initialized to 0 before calling
1055                                          * the BPF program. New fields that
1056                                          * should be initialized to 0 should
1057                                          * be inserted before temp.
1058                                          * temp is scratch storage used by
1059                                          * sock_ops_convert_ctx_access
1060                                          * as temporary storage of a register.
1061                                          */
1062 };
1063 
1064 #endif /* __LINUX_FILTER_H__ */
1065 

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