1 /* 2 * Linux Socket Filter Data Structures 3 */ 4 #ifndef __LINUX_FILTER_H__ 5 #define __LINUX_FILTER_H__ 6 7 #include <stdarg.h> 8 9 #include <linux/atomic.h> 10 #include <linux/compat.h> 11 #include <linux/skbuff.h> 12 #include <linux/linkage.h> 13 #include <linux/printk.h> 14 #include <linux/workqueue.h> 15 #include <linux/sched.h> 16 #include <linux/capability.h> 17 18 #include <net/sch_generic.h> 19 20 #include <asm/cacheflush.h> 21 22 #include <uapi/linux/filter.h> 23 #include <uapi/linux/bpf.h> 24 25 struct sk_buff; 26 struct sock; 27 struct seccomp_data; 28 struct bpf_prog_aux; 29 30 /* ArgX, context and stack frame pointer register positions. Note, 31 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 32 * calls in BPF_CALL instruction. 33 */ 34 #define BPF_REG_ARG1 BPF_REG_1 35 #define BPF_REG_ARG2 BPF_REG_2 36 #define BPF_REG_ARG3 BPF_REG_3 37 #define BPF_REG_ARG4 BPF_REG_4 38 #define BPF_REG_ARG5 BPF_REG_5 39 #define BPF_REG_CTX BPF_REG_6 40 #define BPF_REG_FP BPF_REG_10 41 42 /* Additional register mappings for converted user programs. */ 43 #define BPF_REG_A BPF_REG_0 44 #define BPF_REG_X BPF_REG_7 45 #define BPF_REG_TMP BPF_REG_8 46 47 /* Kernel hidden auxiliary/helper register for hardening step. 48 * Only used by eBPF JITs. It's nothing more than a temporary 49 * register that JITs use internally, only that here it's part 50 * of eBPF instructions that have been rewritten for blinding 51 * constants. See JIT pre-step in bpf_jit_blind_constants(). 52 */ 53 #define BPF_REG_AX MAX_BPF_REG 54 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 55 56 /* BPF program can access up to 512 bytes of stack space. */ 57 #define MAX_BPF_STACK 512 58 59 /* Helper macros for filter block array initializers. */ 60 61 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 62 63 #define BPF_ALU64_REG(OP, DST, SRC) \ 64 ((struct bpf_insn) { \ 65 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 66 .dst_reg = DST, \ 67 .src_reg = SRC, \ 68 .off = 0, \ 69 .imm = 0 }) 70 71 #define BPF_ALU32_REG(OP, DST, SRC) \ 72 ((struct bpf_insn) { \ 73 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 74 .dst_reg = DST, \ 75 .src_reg = SRC, \ 76 .off = 0, \ 77 .imm = 0 }) 78 79 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 80 81 #define BPF_ALU64_IMM(OP, DST, IMM) \ 82 ((struct bpf_insn) { \ 83 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 84 .dst_reg = DST, \ 85 .src_reg = 0, \ 86 .off = 0, \ 87 .imm = IMM }) 88 89 #define BPF_ALU32_IMM(OP, DST, IMM) \ 90 ((struct bpf_insn) { \ 91 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 92 .dst_reg = DST, \ 93 .src_reg = 0, \ 94 .off = 0, \ 95 .imm = IMM }) 96 97 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 98 99 #define BPF_ENDIAN(TYPE, DST, LEN) \ 100 ((struct bpf_insn) { \ 101 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 102 .dst_reg = DST, \ 103 .src_reg = 0, \ 104 .off = 0, \ 105 .imm = LEN }) 106 107 /* Short form of mov, dst_reg = src_reg */ 108 109 #define BPF_MOV64_REG(DST, SRC) \ 110 ((struct bpf_insn) { \ 111 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 112 .dst_reg = DST, \ 113 .src_reg = SRC, \ 114 .off = 0, \ 115 .imm = 0 }) 116 117 #define BPF_MOV32_REG(DST, SRC) \ 118 ((struct bpf_insn) { \ 119 .code = BPF_ALU | BPF_MOV | BPF_X, \ 120 .dst_reg = DST, \ 121 .src_reg = SRC, \ 122 .off = 0, \ 123 .imm = 0 }) 124 125 /* Short form of mov, dst_reg = imm32 */ 126 127 #define BPF_MOV64_IMM(DST, IMM) \ 128 ((struct bpf_insn) { \ 129 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 130 .dst_reg = DST, \ 131 .src_reg = 0, \ 132 .off = 0, \ 133 .imm = IMM }) 134 135 #define BPF_MOV32_IMM(DST, IMM) \ 136 ((struct bpf_insn) { \ 137 .code = BPF_ALU | BPF_MOV | BPF_K, \ 138 .dst_reg = DST, \ 139 .src_reg = 0, \ 140 .off = 0, \ 141 .imm = IMM }) 142 143 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 144 #define BPF_LD_IMM64(DST, IMM) \ 145 BPF_LD_IMM64_RAW(DST, 0, IMM) 146 147 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 148 ((struct bpf_insn) { \ 149 .code = BPF_LD | BPF_DW | BPF_IMM, \ 150 .dst_reg = DST, \ 151 .src_reg = SRC, \ 152 .off = 0, \ 153 .imm = (__u32) (IMM) }), \ 154 ((struct bpf_insn) { \ 155 .code = 0, /* zero is reserved opcode */ \ 156 .dst_reg = 0, \ 157 .src_reg = 0, \ 158 .off = 0, \ 159 .imm = ((__u64) (IMM)) >> 32 }) 160 161 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 162 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 163 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 164 165 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 166 167 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 168 ((struct bpf_insn) { \ 169 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 170 .dst_reg = DST, \ 171 .src_reg = SRC, \ 172 .off = 0, \ 173 .imm = IMM }) 174 175 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 176 ((struct bpf_insn) { \ 177 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 178 .dst_reg = DST, \ 179 .src_reg = SRC, \ 180 .off = 0, \ 181 .imm = IMM }) 182 183 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 184 185 #define BPF_LD_ABS(SIZE, IMM) \ 186 ((struct bpf_insn) { \ 187 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 188 .dst_reg = 0, \ 189 .src_reg = 0, \ 190 .off = 0, \ 191 .imm = IMM }) 192 193 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 194 195 #define BPF_LD_IND(SIZE, SRC, IMM) \ 196 ((struct bpf_insn) { \ 197 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 198 .dst_reg = 0, \ 199 .src_reg = SRC, \ 200 .off = 0, \ 201 .imm = IMM }) 202 203 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 204 205 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 206 ((struct bpf_insn) { \ 207 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 208 .dst_reg = DST, \ 209 .src_reg = SRC, \ 210 .off = OFF, \ 211 .imm = 0 }) 212 213 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 214 215 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 216 ((struct bpf_insn) { \ 217 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 218 .dst_reg = DST, \ 219 .src_reg = SRC, \ 220 .off = OFF, \ 221 .imm = 0 }) 222 223 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 224 225 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 226 ((struct bpf_insn) { \ 227 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 228 .dst_reg = DST, \ 229 .src_reg = SRC, \ 230 .off = OFF, \ 231 .imm = 0 }) 232 233 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 234 235 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 236 ((struct bpf_insn) { \ 237 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 238 .dst_reg = DST, \ 239 .src_reg = 0, \ 240 .off = OFF, \ 241 .imm = IMM }) 242 243 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 244 245 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 246 ((struct bpf_insn) { \ 247 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 248 .dst_reg = DST, \ 249 .src_reg = SRC, \ 250 .off = OFF, \ 251 .imm = 0 }) 252 253 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 254 255 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 256 ((struct bpf_insn) { \ 257 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 258 .dst_reg = DST, \ 259 .src_reg = 0, \ 260 .off = OFF, \ 261 .imm = IMM }) 262 263 /* Function call */ 264 265 #define BPF_EMIT_CALL(FUNC) \ 266 ((struct bpf_insn) { \ 267 .code = BPF_JMP | BPF_CALL, \ 268 .dst_reg = 0, \ 269 .src_reg = 0, \ 270 .off = 0, \ 271 .imm = ((FUNC) - __bpf_call_base) }) 272 273 /* Raw code statement block */ 274 275 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 276 ((struct bpf_insn) { \ 277 .code = CODE, \ 278 .dst_reg = DST, \ 279 .src_reg = SRC, \ 280 .off = OFF, \ 281 .imm = IMM }) 282 283 /* Program exit */ 284 285 #define BPF_EXIT_INSN() \ 286 ((struct bpf_insn) { \ 287 .code = BPF_JMP | BPF_EXIT, \ 288 .dst_reg = 0, \ 289 .src_reg = 0, \ 290 .off = 0, \ 291 .imm = 0 }) 292 293 /* Internal classic blocks for direct assignment */ 294 295 #define __BPF_STMT(CODE, K) \ 296 ((struct sock_filter) BPF_STMT(CODE, K)) 297 298 #define __BPF_JUMP(CODE, K, JT, JF) \ 299 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 300 301 #define bytes_to_bpf_size(bytes) \ 302 ({ \ 303 int bpf_size = -EINVAL; \ 304 \ 305 if (bytes == sizeof(u8)) \ 306 bpf_size = BPF_B; \ 307 else if (bytes == sizeof(u16)) \ 308 bpf_size = BPF_H; \ 309 else if (bytes == sizeof(u32)) \ 310 bpf_size = BPF_W; \ 311 else if (bytes == sizeof(u64)) \ 312 bpf_size = BPF_DW; \ 313 \ 314 bpf_size; \ 315 }) 316 317 #define BPF_SIZEOF(type) \ 318 ({ \ 319 const int __size = bytes_to_bpf_size(sizeof(type)); \ 320 BUILD_BUG_ON(__size < 0); \ 321 __size; \ 322 }) 323 324 #define BPF_FIELD_SIZEOF(type, field) \ 325 ({ \ 326 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 327 BUILD_BUG_ON(__size < 0); \ 328 __size; \ 329 }) 330 331 #define __BPF_MAP_0(m, v, ...) v 332 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 333 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 334 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 335 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 336 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 337 338 #define __BPF_REG_0(...) __BPF_PAD(5) 339 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 340 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 341 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 342 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 343 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 344 345 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 346 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 347 348 #define __BPF_CAST(t, a) \ 349 (__force t) \ 350 (__force \ 351 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 352 (unsigned long)0, (t)0))) a 353 #define __BPF_V void 354 #define __BPF_N 355 356 #define __BPF_DECL_ARGS(t, a) t a 357 #define __BPF_DECL_REGS(t, a) u64 a 358 359 #define __BPF_PAD(n) \ 360 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 361 u64, __ur_3, u64, __ur_4, u64, __ur_5) 362 363 #define BPF_CALL_x(x, name, ...) \ 364 static __always_inline \ 365 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 366 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 367 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 368 { \ 369 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 370 } \ 371 static __always_inline \ 372 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 373 374 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 375 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 376 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 377 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 378 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 379 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 380 381 #ifdef CONFIG_COMPAT 382 /* A struct sock_filter is architecture independent. */ 383 struct compat_sock_fprog { 384 u16 len; 385 compat_uptr_t filter; /* struct sock_filter * */ 386 }; 387 #endif 388 389 struct sock_fprog_kern { 390 u16 len; 391 struct sock_filter *filter; 392 }; 393 394 struct bpf_binary_header { 395 unsigned int pages; 396 u8 image[]; 397 }; 398 399 struct bpf_prog { 400 u16 pages; /* Number of allocated pages */ 401 kmemcheck_bitfield_begin(meta); 402 u16 jited:1, /* Is our filter JIT'ed? */ 403 gpl_compatible:1, /* Is filter GPL compatible? */ 404 cb_access:1, /* Is control block accessed? */ 405 dst_needed:1; /* Do we need dst entry? */ 406 kmemcheck_bitfield_end(meta); 407 u32 len; /* Number of filter blocks */ 408 enum bpf_prog_type type; /* Type of BPF program */ 409 struct bpf_prog_aux *aux; /* Auxiliary fields */ 410 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 411 unsigned int (*bpf_func)(const struct sk_buff *skb, 412 const struct bpf_insn *filter); 413 /* Instructions for interpreter */ 414 union { 415 struct sock_filter insns[0]; 416 struct bpf_insn insnsi[0]; 417 }; 418 }; 419 420 struct sk_filter { 421 atomic_t refcnt; 422 struct rcu_head rcu; 423 struct bpf_prog *prog; 424 }; 425 426 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 427 428 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 429 430 struct bpf_skb_data_end { 431 struct qdisc_skb_cb qdisc_cb; 432 void *data_end; 433 }; 434 435 struct xdp_buff { 436 void *data; 437 void *data_end; 438 }; 439 440 /* compute the linear packet data range [data, data_end) which 441 * will be accessed by cls_bpf and act_bpf programs 442 */ 443 static inline void bpf_compute_data_end(struct sk_buff *skb) 444 { 445 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 446 447 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 448 cb->data_end = skb->data + skb_headlen(skb); 449 } 450 451 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 452 { 453 /* eBPF programs may read/write skb->cb[] area to transfer meta 454 * data between tail calls. Since this also needs to work with 455 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 456 * 457 * In some socket filter cases, the cb unfortunately needs to be 458 * saved/restored so that protocol specific skb->cb[] data won't 459 * be lost. In any case, due to unpriviledged eBPF programs 460 * attached to sockets, we need to clear the bpf_skb_cb() area 461 * to not leak previous contents to user space. 462 */ 463 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 464 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 465 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 466 467 return qdisc_skb_cb(skb)->data; 468 } 469 470 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 471 struct sk_buff *skb) 472 { 473 u8 *cb_data = bpf_skb_cb(skb); 474 u8 cb_saved[BPF_SKB_CB_LEN]; 475 u32 res; 476 477 if (unlikely(prog->cb_access)) { 478 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 479 memset(cb_data, 0, sizeof(cb_saved)); 480 } 481 482 res = BPF_PROG_RUN(prog, skb); 483 484 if (unlikely(prog->cb_access)) 485 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 486 487 return res; 488 } 489 490 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 491 struct sk_buff *skb) 492 { 493 u8 *cb_data = bpf_skb_cb(skb); 494 495 if (unlikely(prog->cb_access)) 496 memset(cb_data, 0, BPF_SKB_CB_LEN); 497 498 return BPF_PROG_RUN(prog, skb); 499 } 500 501 static inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 502 struct xdp_buff *xdp) 503 { 504 u32 ret; 505 506 rcu_read_lock(); 507 ret = BPF_PROG_RUN(prog, (void *)xdp); 508 rcu_read_unlock(); 509 510 return ret; 511 } 512 513 static inline unsigned int bpf_prog_size(unsigned int proglen) 514 { 515 return max(sizeof(struct bpf_prog), 516 offsetof(struct bpf_prog, insns[proglen])); 517 } 518 519 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 520 { 521 /* When classic BPF programs have been loaded and the arch 522 * does not have a classic BPF JIT (anymore), they have been 523 * converted via bpf_migrate_filter() to eBPF and thus always 524 * have an unspec program type. 525 */ 526 return prog->type == BPF_PROG_TYPE_UNSPEC; 527 } 528 529 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 530 531 #ifdef CONFIG_DEBUG_SET_MODULE_RONX 532 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 533 { 534 set_memory_ro((unsigned long)fp, fp->pages); 535 } 536 537 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 538 { 539 set_memory_rw((unsigned long)fp, fp->pages); 540 } 541 #else 542 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 543 { 544 } 545 546 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 547 { 548 } 549 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */ 550 551 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 552 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 553 { 554 return sk_filter_trim_cap(sk, skb, 1); 555 } 556 557 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 558 void bpf_prog_free(struct bpf_prog *fp); 559 560 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 561 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 562 gfp_t gfp_extra_flags); 563 void __bpf_prog_free(struct bpf_prog *fp); 564 565 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 566 { 567 bpf_prog_unlock_ro(fp); 568 __bpf_prog_free(fp); 569 } 570 571 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 572 unsigned int flen); 573 574 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 575 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 576 bpf_aux_classic_check_t trans, bool save_orig); 577 void bpf_prog_destroy(struct bpf_prog *fp); 578 579 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 580 int sk_attach_bpf(u32 ufd, struct sock *sk); 581 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 582 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 583 int sk_detach_filter(struct sock *sk); 584 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 585 unsigned int len); 586 587 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 588 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 589 590 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 591 592 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 593 bool bpf_helper_changes_skb_data(void *func); 594 595 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 596 const struct bpf_insn *patch, u32 len); 597 void bpf_warn_invalid_xdp_action(u32 act); 598 599 #ifdef CONFIG_BPF_JIT 600 extern int bpf_jit_enable; 601 extern int bpf_jit_harden; 602 603 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 604 605 struct bpf_binary_header * 606 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 607 unsigned int alignment, 608 bpf_jit_fill_hole_t bpf_fill_ill_insns); 609 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 610 611 void bpf_jit_compile(struct bpf_prog *fp); 612 void bpf_jit_free(struct bpf_prog *fp); 613 614 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 615 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 616 617 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 618 u32 pass, void *image) 619 { 620 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 621 proglen, pass, image, current->comm, task_pid_nr(current)); 622 623 if (image) 624 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 625 16, 1, image, proglen, false); 626 } 627 628 static inline bool bpf_jit_is_ebpf(void) 629 { 630 # ifdef CONFIG_HAVE_EBPF_JIT 631 return true; 632 # else 633 return false; 634 # endif 635 } 636 637 static inline bool bpf_jit_blinding_enabled(void) 638 { 639 /* These are the prerequisites, should someone ever have the 640 * idea to call blinding outside of them, we make sure to 641 * bail out. 642 */ 643 if (!bpf_jit_is_ebpf()) 644 return false; 645 if (!bpf_jit_enable) 646 return false; 647 if (!bpf_jit_harden) 648 return false; 649 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 650 return false; 651 652 return true; 653 } 654 #else 655 static inline void bpf_jit_compile(struct bpf_prog *fp) 656 { 657 } 658 659 static inline void bpf_jit_free(struct bpf_prog *fp) 660 { 661 bpf_prog_unlock_free(fp); 662 } 663 #endif /* CONFIG_BPF_JIT */ 664 665 #define BPF_ANC BIT(15) 666 667 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 668 { 669 switch (first->code) { 670 case BPF_RET | BPF_K: 671 case BPF_LD | BPF_W | BPF_LEN: 672 return false; 673 674 case BPF_LD | BPF_W | BPF_ABS: 675 case BPF_LD | BPF_H | BPF_ABS: 676 case BPF_LD | BPF_B | BPF_ABS: 677 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 678 return true; 679 return false; 680 681 default: 682 return true; 683 } 684 } 685 686 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 687 { 688 BUG_ON(ftest->code & BPF_ANC); 689 690 switch (ftest->code) { 691 case BPF_LD | BPF_W | BPF_ABS: 692 case BPF_LD | BPF_H | BPF_ABS: 693 case BPF_LD | BPF_B | BPF_ABS: 694 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 695 return BPF_ANC | SKF_AD_##CODE 696 switch (ftest->k) { 697 BPF_ANCILLARY(PROTOCOL); 698 BPF_ANCILLARY(PKTTYPE); 699 BPF_ANCILLARY(IFINDEX); 700 BPF_ANCILLARY(NLATTR); 701 BPF_ANCILLARY(NLATTR_NEST); 702 BPF_ANCILLARY(MARK); 703 BPF_ANCILLARY(QUEUE); 704 BPF_ANCILLARY(HATYPE); 705 BPF_ANCILLARY(RXHASH); 706 BPF_ANCILLARY(CPU); 707 BPF_ANCILLARY(ALU_XOR_X); 708 BPF_ANCILLARY(VLAN_TAG); 709 BPF_ANCILLARY(VLAN_TAG_PRESENT); 710 BPF_ANCILLARY(PAY_OFFSET); 711 BPF_ANCILLARY(RANDOM); 712 BPF_ANCILLARY(VLAN_TPID); 713 } 714 /* Fallthrough. */ 715 default: 716 return ftest->code; 717 } 718 } 719 720 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 721 int k, unsigned int size); 722 723 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 724 unsigned int size, void *buffer) 725 { 726 if (k >= 0) 727 return skb_header_pointer(skb, k, size, buffer); 728 729 return bpf_internal_load_pointer_neg_helper(skb, k, size); 730 } 731 732 static inline int bpf_tell_extensions(void) 733 { 734 return SKF_AD_MAX; 735 } 736 737 #endif /* __LINUX_FILTER_H__ */ 738