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