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 /* Helper macros for filter block array initializers. */ 61 62 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 63 64 #define BPF_ALU64_REG(OP, DST, SRC) \ 65 ((struct bpf_insn) { \ 66 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 67 .dst_reg = DST, \ 68 .src_reg = SRC, \ 69 .off = 0, \ 70 .imm = 0 }) 71 72 #define BPF_ALU32_REG(OP, DST, SRC) \ 73 ((struct bpf_insn) { \ 74 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 75 .dst_reg = DST, \ 76 .src_reg = SRC, \ 77 .off = 0, \ 78 .imm = 0 }) 79 80 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 81 82 #define BPF_ALU64_IMM(OP, DST, IMM) \ 83 ((struct bpf_insn) { \ 84 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 85 .dst_reg = DST, \ 86 .src_reg = 0, \ 87 .off = 0, \ 88 .imm = IMM }) 89 90 #define BPF_ALU32_IMM(OP, DST, IMM) \ 91 ((struct bpf_insn) { \ 92 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 93 .dst_reg = DST, \ 94 .src_reg = 0, \ 95 .off = 0, \ 96 .imm = IMM }) 97 98 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 99 100 #define BPF_ENDIAN(TYPE, DST, LEN) \ 101 ((struct bpf_insn) { \ 102 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 103 .dst_reg = DST, \ 104 .src_reg = 0, \ 105 .off = 0, \ 106 .imm = LEN }) 107 108 /* Short form of mov, dst_reg = src_reg */ 109 110 #define BPF_MOV64_REG(DST, SRC) \ 111 ((struct bpf_insn) { \ 112 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 113 .dst_reg = DST, \ 114 .src_reg = SRC, \ 115 .off = 0, \ 116 .imm = 0 }) 117 118 #define BPF_MOV32_REG(DST, SRC) \ 119 ((struct bpf_insn) { \ 120 .code = BPF_ALU | BPF_MOV | BPF_X, \ 121 .dst_reg = DST, \ 122 .src_reg = SRC, \ 123 .off = 0, \ 124 .imm = 0 }) 125 126 /* Short form of mov, dst_reg = imm32 */ 127 128 #define BPF_MOV64_IMM(DST, IMM) \ 129 ((struct bpf_insn) { \ 130 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 131 .dst_reg = DST, \ 132 .src_reg = 0, \ 133 .off = 0, \ 134 .imm = IMM }) 135 136 #define BPF_MOV32_IMM(DST, IMM) \ 137 ((struct bpf_insn) { \ 138 .code = BPF_ALU | BPF_MOV | BPF_K, \ 139 .dst_reg = DST, \ 140 .src_reg = 0, \ 141 .off = 0, \ 142 .imm = IMM }) 143 144 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 145 #define BPF_LD_IMM64(DST, IMM) \ 146 BPF_LD_IMM64_RAW(DST, 0, IMM) 147 148 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 149 ((struct bpf_insn) { \ 150 .code = BPF_LD | BPF_DW | BPF_IMM, \ 151 .dst_reg = DST, \ 152 .src_reg = SRC, \ 153 .off = 0, \ 154 .imm = (__u32) (IMM) }), \ 155 ((struct bpf_insn) { \ 156 .code = 0, /* zero is reserved opcode */ \ 157 .dst_reg = 0, \ 158 .src_reg = 0, \ 159 .off = 0, \ 160 .imm = ((__u64) (IMM)) >> 32 }) 161 162 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 163 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 164 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 165 166 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 167 168 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 169 ((struct bpf_insn) { \ 170 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 171 .dst_reg = DST, \ 172 .src_reg = SRC, \ 173 .off = 0, \ 174 .imm = IMM }) 175 176 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 177 ((struct bpf_insn) { \ 178 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 179 .dst_reg = DST, \ 180 .src_reg = SRC, \ 181 .off = 0, \ 182 .imm = IMM }) 183 184 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 185 186 #define BPF_LD_ABS(SIZE, IMM) \ 187 ((struct bpf_insn) { \ 188 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 189 .dst_reg = 0, \ 190 .src_reg = 0, \ 191 .off = 0, \ 192 .imm = IMM }) 193 194 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 195 196 #define BPF_LD_IND(SIZE, SRC, IMM) \ 197 ((struct bpf_insn) { \ 198 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 199 .dst_reg = 0, \ 200 .src_reg = SRC, \ 201 .off = 0, \ 202 .imm = IMM }) 203 204 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 205 206 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 207 ((struct bpf_insn) { \ 208 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 209 .dst_reg = DST, \ 210 .src_reg = SRC, \ 211 .off = OFF, \ 212 .imm = 0 }) 213 214 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 215 216 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 217 ((struct bpf_insn) { \ 218 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 219 .dst_reg = DST, \ 220 .src_reg = SRC, \ 221 .off = OFF, \ 222 .imm = 0 }) 223 224 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 225 226 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 227 ((struct bpf_insn) { \ 228 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 229 .dst_reg = DST, \ 230 .src_reg = SRC, \ 231 .off = OFF, \ 232 .imm = 0 }) 233 234 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 235 236 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 237 ((struct bpf_insn) { \ 238 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 239 .dst_reg = DST, \ 240 .src_reg = 0, \ 241 .off = OFF, \ 242 .imm = IMM }) 243 244 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 245 246 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 247 ((struct bpf_insn) { \ 248 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 249 .dst_reg = DST, \ 250 .src_reg = SRC, \ 251 .off = OFF, \ 252 .imm = 0 }) 253 254 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 255 256 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 257 ((struct bpf_insn) { \ 258 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 259 .dst_reg = DST, \ 260 .src_reg = 0, \ 261 .off = OFF, \ 262 .imm = IMM }) 263 264 /* Function call */ 265 266 #define BPF_EMIT_CALL(FUNC) \ 267 ((struct bpf_insn) { \ 268 .code = BPF_JMP | BPF_CALL, \ 269 .dst_reg = 0, \ 270 .src_reg = 0, \ 271 .off = 0, \ 272 .imm = ((FUNC) - __bpf_call_base) }) 273 274 /* Raw code statement block */ 275 276 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 277 ((struct bpf_insn) { \ 278 .code = CODE, \ 279 .dst_reg = DST, \ 280 .src_reg = SRC, \ 281 .off = OFF, \ 282 .imm = IMM }) 283 284 /* Program exit */ 285 286 #define BPF_EXIT_INSN() \ 287 ((struct bpf_insn) { \ 288 .code = BPF_JMP | BPF_EXIT, \ 289 .dst_reg = 0, \ 290 .src_reg = 0, \ 291 .off = 0, \ 292 .imm = 0 }) 293 294 /* Internal classic blocks for direct assignment */ 295 296 #define __BPF_STMT(CODE, K) \ 297 ((struct sock_filter) BPF_STMT(CODE, K)) 298 299 #define __BPF_JUMP(CODE, K, JT, JF) \ 300 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 301 302 #define bytes_to_bpf_size(bytes) \ 303 ({ \ 304 int bpf_size = -EINVAL; \ 305 \ 306 if (bytes == sizeof(u8)) \ 307 bpf_size = BPF_B; \ 308 else if (bytes == sizeof(u16)) \ 309 bpf_size = BPF_H; \ 310 else if (bytes == sizeof(u32)) \ 311 bpf_size = BPF_W; \ 312 else if (bytes == sizeof(u64)) \ 313 bpf_size = BPF_DW; \ 314 \ 315 bpf_size; \ 316 }) 317 318 #define BPF_SIZEOF(type) \ 319 ({ \ 320 const int __size = bytes_to_bpf_size(sizeof(type)); \ 321 BUILD_BUG_ON(__size < 0); \ 322 __size; \ 323 }) 324 325 #define BPF_FIELD_SIZEOF(type, field) \ 326 ({ \ 327 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 328 BUILD_BUG_ON(__size < 0); \ 329 __size; \ 330 }) 331 332 #define __BPF_MAP_0(m, v, ...) v 333 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 334 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 335 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 336 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 337 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 338 339 #define __BPF_REG_0(...) __BPF_PAD(5) 340 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 341 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 342 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 343 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 344 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 345 346 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 347 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 348 349 #define __BPF_CAST(t, a) \ 350 (__force t) \ 351 (__force \ 352 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 353 (unsigned long)0, (t)0))) a 354 #define __BPF_V void 355 #define __BPF_N 356 357 #define __BPF_DECL_ARGS(t, a) t a 358 #define __BPF_DECL_REGS(t, a) u64 a 359 360 #define __BPF_PAD(n) \ 361 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 362 u64, __ur_3, u64, __ur_4, u64, __ur_5) 363 364 #define BPF_CALL_x(x, name, ...) \ 365 static __always_inline \ 366 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 367 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 368 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 369 { \ 370 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 371 } \ 372 static __always_inline \ 373 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 374 375 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 376 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 377 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 378 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 379 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 380 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 381 382 #ifdef CONFIG_COMPAT 383 /* A struct sock_filter is architecture independent. */ 384 struct compat_sock_fprog { 385 u16 len; 386 compat_uptr_t filter; /* struct sock_filter * */ 387 }; 388 #endif 389 390 struct sock_fprog_kern { 391 u16 len; 392 struct sock_filter *filter; 393 }; 394 395 struct bpf_binary_header { 396 unsigned int pages; 397 u8 image[]; 398 }; 399 400 struct bpf_prog { 401 u16 pages; /* Number of allocated pages */ 402 kmemcheck_bitfield_begin(meta); 403 u16 jited:1, /* Is our filter JIT'ed? */ 404 gpl_compatible:1, /* Is filter GPL compatible? */ 405 cb_access:1, /* Is control block accessed? */ 406 dst_needed:1, /* Do we need dst entry? */ 407 xdp_adjust_head:1; /* Adjusting pkt head? */ 408 kmemcheck_bitfield_end(meta); 409 enum bpf_prog_type type; /* Type of BPF program */ 410 u32 len; /* Number of filter blocks */ 411 u32 digest[SHA_DIGEST_WORDS]; /* Program digest */ 412 struct bpf_prog_aux *aux; /* Auxiliary fields */ 413 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 414 unsigned int (*bpf_func)(const void *ctx, 415 const struct bpf_insn *insn); 416 /* Instructions for interpreter */ 417 union { 418 struct sock_filter insns[0]; 419 struct bpf_insn insnsi[0]; 420 }; 421 }; 422 423 struct sk_filter { 424 atomic_t refcnt; 425 struct rcu_head rcu; 426 struct bpf_prog *prog; 427 }; 428 429 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 430 431 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 432 433 struct bpf_skb_data_end { 434 struct qdisc_skb_cb qdisc_cb; 435 void *data_end; 436 }; 437 438 struct xdp_buff { 439 void *data; 440 void *data_end; 441 void *data_hard_start; 442 }; 443 444 /* compute the linear packet data range [data, data_end) which 445 * will be accessed by cls_bpf, act_bpf and lwt programs 446 */ 447 static inline void bpf_compute_data_end(struct sk_buff *skb) 448 { 449 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 450 451 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 452 cb->data_end = skb->data + skb_headlen(skb); 453 } 454 455 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 456 { 457 /* eBPF programs may read/write skb->cb[] area to transfer meta 458 * data between tail calls. Since this also needs to work with 459 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 460 * 461 * In some socket filter cases, the cb unfortunately needs to be 462 * saved/restored so that protocol specific skb->cb[] data won't 463 * be lost. In any case, due to unpriviledged eBPF programs 464 * attached to sockets, we need to clear the bpf_skb_cb() area 465 * to not leak previous contents to user space. 466 */ 467 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 468 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 469 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 470 471 return qdisc_skb_cb(skb)->data; 472 } 473 474 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 475 struct sk_buff *skb) 476 { 477 u8 *cb_data = bpf_skb_cb(skb); 478 u8 cb_saved[BPF_SKB_CB_LEN]; 479 u32 res; 480 481 if (unlikely(prog->cb_access)) { 482 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 483 memset(cb_data, 0, sizeof(cb_saved)); 484 } 485 486 res = BPF_PROG_RUN(prog, skb); 487 488 if (unlikely(prog->cb_access)) 489 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 490 491 return res; 492 } 493 494 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 495 struct sk_buff *skb) 496 { 497 u8 *cb_data = bpf_skb_cb(skb); 498 499 if (unlikely(prog->cb_access)) 500 memset(cb_data, 0, BPF_SKB_CB_LEN); 501 502 return BPF_PROG_RUN(prog, skb); 503 } 504 505 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 506 struct xdp_buff *xdp) 507 { 508 /* Caller needs to hold rcu_read_lock() (!), otherwise program 509 * can be released while still running, or map elements could be 510 * freed early while still having concurrent users. XDP fastpath 511 * already takes rcu_read_lock() when fetching the program, so 512 * it's not necessary here anymore. 513 */ 514 return BPF_PROG_RUN(prog, xdp); 515 } 516 517 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 518 { 519 return prog->len * sizeof(struct bpf_insn); 520 } 521 522 static inline u32 bpf_prog_digest_scratch_size(const struct bpf_prog *prog) 523 { 524 return round_up(bpf_prog_insn_size(prog) + 525 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 526 } 527 528 static inline unsigned int bpf_prog_size(unsigned int proglen) 529 { 530 return max(sizeof(struct bpf_prog), 531 offsetof(struct bpf_prog, insns[proglen])); 532 } 533 534 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 535 { 536 /* When classic BPF programs have been loaded and the arch 537 * does not have a classic BPF JIT (anymore), they have been 538 * converted via bpf_migrate_filter() to eBPF and thus always 539 * have an unspec program type. 540 */ 541 return prog->type == BPF_PROG_TYPE_UNSPEC; 542 } 543 544 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 545 546 #ifdef CONFIG_DEBUG_SET_MODULE_RONX 547 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 548 { 549 set_memory_ro((unsigned long)fp, fp->pages); 550 } 551 552 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 553 { 554 set_memory_rw((unsigned long)fp, fp->pages); 555 } 556 #else 557 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 558 { 559 } 560 561 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 562 { 563 } 564 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */ 565 566 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 567 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 568 { 569 return sk_filter_trim_cap(sk, skb, 1); 570 } 571 572 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 573 void bpf_prog_free(struct bpf_prog *fp); 574 575 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 576 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 577 gfp_t gfp_extra_flags); 578 void __bpf_prog_free(struct bpf_prog *fp); 579 580 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 581 { 582 bpf_prog_unlock_ro(fp); 583 __bpf_prog_free(fp); 584 } 585 586 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 587 unsigned int flen); 588 589 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 590 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 591 bpf_aux_classic_check_t trans, bool save_orig); 592 void bpf_prog_destroy(struct bpf_prog *fp); 593 594 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 595 int sk_attach_bpf(u32 ufd, struct sock *sk); 596 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 597 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 598 int sk_detach_filter(struct sock *sk); 599 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 600 unsigned int len); 601 602 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 603 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 604 605 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 606 607 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 608 bool bpf_helper_changes_pkt_data(void *func); 609 610 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 611 const struct bpf_insn *patch, u32 len); 612 void bpf_warn_invalid_xdp_action(u32 act); 613 614 #ifdef CONFIG_BPF_JIT 615 extern int bpf_jit_enable; 616 extern int bpf_jit_harden; 617 618 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 619 620 struct bpf_binary_header * 621 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 622 unsigned int alignment, 623 bpf_jit_fill_hole_t bpf_fill_ill_insns); 624 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 625 626 void bpf_jit_compile(struct bpf_prog *fp); 627 void bpf_jit_free(struct bpf_prog *fp); 628 629 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 630 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 631 632 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 633 u32 pass, void *image) 634 { 635 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 636 proglen, pass, image, current->comm, task_pid_nr(current)); 637 638 if (image) 639 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 640 16, 1, image, proglen, false); 641 } 642 643 static inline bool bpf_jit_is_ebpf(void) 644 { 645 # ifdef CONFIG_HAVE_EBPF_JIT 646 return true; 647 # else 648 return false; 649 # endif 650 } 651 652 static inline bool bpf_jit_blinding_enabled(void) 653 { 654 /* These are the prerequisites, should someone ever have the 655 * idea to call blinding outside of them, we make sure to 656 * bail out. 657 */ 658 if (!bpf_jit_is_ebpf()) 659 return false; 660 if (!bpf_jit_enable) 661 return false; 662 if (!bpf_jit_harden) 663 return false; 664 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 665 return false; 666 667 return true; 668 } 669 #else 670 static inline void bpf_jit_compile(struct bpf_prog *fp) 671 { 672 } 673 674 static inline void bpf_jit_free(struct bpf_prog *fp) 675 { 676 bpf_prog_unlock_free(fp); 677 } 678 #endif /* CONFIG_BPF_JIT */ 679 680 #define BPF_ANC BIT(15) 681 682 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 683 { 684 switch (first->code) { 685 case BPF_RET | BPF_K: 686 case BPF_LD | BPF_W | BPF_LEN: 687 return false; 688 689 case BPF_LD | BPF_W | BPF_ABS: 690 case BPF_LD | BPF_H | BPF_ABS: 691 case BPF_LD | BPF_B | BPF_ABS: 692 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 693 return true; 694 return false; 695 696 default: 697 return true; 698 } 699 } 700 701 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 702 { 703 BUG_ON(ftest->code & BPF_ANC); 704 705 switch (ftest->code) { 706 case BPF_LD | BPF_W | BPF_ABS: 707 case BPF_LD | BPF_H | BPF_ABS: 708 case BPF_LD | BPF_B | BPF_ABS: 709 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 710 return BPF_ANC | SKF_AD_##CODE 711 switch (ftest->k) { 712 BPF_ANCILLARY(PROTOCOL); 713 BPF_ANCILLARY(PKTTYPE); 714 BPF_ANCILLARY(IFINDEX); 715 BPF_ANCILLARY(NLATTR); 716 BPF_ANCILLARY(NLATTR_NEST); 717 BPF_ANCILLARY(MARK); 718 BPF_ANCILLARY(QUEUE); 719 BPF_ANCILLARY(HATYPE); 720 BPF_ANCILLARY(RXHASH); 721 BPF_ANCILLARY(CPU); 722 BPF_ANCILLARY(ALU_XOR_X); 723 BPF_ANCILLARY(VLAN_TAG); 724 BPF_ANCILLARY(VLAN_TAG_PRESENT); 725 BPF_ANCILLARY(PAY_OFFSET); 726 BPF_ANCILLARY(RANDOM); 727 BPF_ANCILLARY(VLAN_TPID); 728 } 729 /* Fallthrough. */ 730 default: 731 return ftest->code; 732 } 733 } 734 735 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 736 int k, unsigned int size); 737 738 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 739 unsigned int size, void *buffer) 740 { 741 if (k >= 0) 742 return skb_header_pointer(skb, k, size, buffer); 743 744 return bpf_internal_load_pointer_neg_helper(skb, k, size); 745 } 746 747 static inline int bpf_tell_extensions(void) 748 { 749 return SKF_AD_MAX; 750 } 751 752 #endif /* __LINUX_FILTER_H__ */ 753