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 #define BPF_TAG_SIZE 8 61 62 /* Helper macros for filter block array initializers. */ 63 64 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 65 66 #define BPF_ALU64_REG(OP, DST, SRC) \ 67 ((struct bpf_insn) { \ 68 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 69 .dst_reg = DST, \ 70 .src_reg = SRC, \ 71 .off = 0, \ 72 .imm = 0 }) 73 74 #define BPF_ALU32_REG(OP, DST, SRC) \ 75 ((struct bpf_insn) { \ 76 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 77 .dst_reg = DST, \ 78 .src_reg = SRC, \ 79 .off = 0, \ 80 .imm = 0 }) 81 82 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 83 84 #define BPF_ALU64_IMM(OP, DST, IMM) \ 85 ((struct bpf_insn) { \ 86 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 87 .dst_reg = DST, \ 88 .src_reg = 0, \ 89 .off = 0, \ 90 .imm = IMM }) 91 92 #define BPF_ALU32_IMM(OP, DST, IMM) \ 93 ((struct bpf_insn) { \ 94 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 95 .dst_reg = DST, \ 96 .src_reg = 0, \ 97 .off = 0, \ 98 .imm = IMM }) 99 100 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 101 102 #define BPF_ENDIAN(TYPE, DST, LEN) \ 103 ((struct bpf_insn) { \ 104 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 105 .dst_reg = DST, \ 106 .src_reg = 0, \ 107 .off = 0, \ 108 .imm = LEN }) 109 110 /* Short form of mov, dst_reg = src_reg */ 111 112 #define BPF_MOV64_REG(DST, SRC) \ 113 ((struct bpf_insn) { \ 114 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 115 .dst_reg = DST, \ 116 .src_reg = SRC, \ 117 .off = 0, \ 118 .imm = 0 }) 119 120 #define BPF_MOV32_REG(DST, SRC) \ 121 ((struct bpf_insn) { \ 122 .code = BPF_ALU | BPF_MOV | BPF_X, \ 123 .dst_reg = DST, \ 124 .src_reg = SRC, \ 125 .off = 0, \ 126 .imm = 0 }) 127 128 /* Short form of mov, dst_reg = imm32 */ 129 130 #define BPF_MOV64_IMM(DST, IMM) \ 131 ((struct bpf_insn) { \ 132 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 133 .dst_reg = DST, \ 134 .src_reg = 0, \ 135 .off = 0, \ 136 .imm = IMM }) 137 138 #define BPF_MOV32_IMM(DST, IMM) \ 139 ((struct bpf_insn) { \ 140 .code = BPF_ALU | BPF_MOV | BPF_K, \ 141 .dst_reg = DST, \ 142 .src_reg = 0, \ 143 .off = 0, \ 144 .imm = IMM }) 145 146 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 147 #define BPF_LD_IMM64(DST, IMM) \ 148 BPF_LD_IMM64_RAW(DST, 0, IMM) 149 150 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 151 ((struct bpf_insn) { \ 152 .code = BPF_LD | BPF_DW | BPF_IMM, \ 153 .dst_reg = DST, \ 154 .src_reg = SRC, \ 155 .off = 0, \ 156 .imm = (__u32) (IMM) }), \ 157 ((struct bpf_insn) { \ 158 .code = 0, /* zero is reserved opcode */ \ 159 .dst_reg = 0, \ 160 .src_reg = 0, \ 161 .off = 0, \ 162 .imm = ((__u64) (IMM)) >> 32 }) 163 164 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 165 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 166 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 167 168 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 169 170 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 171 ((struct bpf_insn) { \ 172 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 173 .dst_reg = DST, \ 174 .src_reg = SRC, \ 175 .off = 0, \ 176 .imm = IMM }) 177 178 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 179 ((struct bpf_insn) { \ 180 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 181 .dst_reg = DST, \ 182 .src_reg = SRC, \ 183 .off = 0, \ 184 .imm = IMM }) 185 186 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 187 188 #define BPF_LD_ABS(SIZE, IMM) \ 189 ((struct bpf_insn) { \ 190 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 191 .dst_reg = 0, \ 192 .src_reg = 0, \ 193 .off = 0, \ 194 .imm = IMM }) 195 196 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 197 198 #define BPF_LD_IND(SIZE, SRC, IMM) \ 199 ((struct bpf_insn) { \ 200 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 201 .dst_reg = 0, \ 202 .src_reg = SRC, \ 203 .off = 0, \ 204 .imm = IMM }) 205 206 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 207 208 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 209 ((struct bpf_insn) { \ 210 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 211 .dst_reg = DST, \ 212 .src_reg = SRC, \ 213 .off = OFF, \ 214 .imm = 0 }) 215 216 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 217 218 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 219 ((struct bpf_insn) { \ 220 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 221 .dst_reg = DST, \ 222 .src_reg = SRC, \ 223 .off = OFF, \ 224 .imm = 0 }) 225 226 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 227 228 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 229 ((struct bpf_insn) { \ 230 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 231 .dst_reg = DST, \ 232 .src_reg = SRC, \ 233 .off = OFF, \ 234 .imm = 0 }) 235 236 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 237 238 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 239 ((struct bpf_insn) { \ 240 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 241 .dst_reg = DST, \ 242 .src_reg = 0, \ 243 .off = OFF, \ 244 .imm = IMM }) 245 246 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 247 248 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 249 ((struct bpf_insn) { \ 250 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 251 .dst_reg = DST, \ 252 .src_reg = SRC, \ 253 .off = OFF, \ 254 .imm = 0 }) 255 256 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 257 258 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 259 ((struct bpf_insn) { \ 260 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 261 .dst_reg = DST, \ 262 .src_reg = 0, \ 263 .off = OFF, \ 264 .imm = IMM }) 265 266 /* Function call */ 267 268 #define BPF_EMIT_CALL(FUNC) \ 269 ((struct bpf_insn) { \ 270 .code = BPF_JMP | BPF_CALL, \ 271 .dst_reg = 0, \ 272 .src_reg = 0, \ 273 .off = 0, \ 274 .imm = ((FUNC) - __bpf_call_base) }) 275 276 /* Raw code statement block */ 277 278 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 279 ((struct bpf_insn) { \ 280 .code = CODE, \ 281 .dst_reg = DST, \ 282 .src_reg = SRC, \ 283 .off = OFF, \ 284 .imm = IMM }) 285 286 /* Program exit */ 287 288 #define BPF_EXIT_INSN() \ 289 ((struct bpf_insn) { \ 290 .code = BPF_JMP | BPF_EXIT, \ 291 .dst_reg = 0, \ 292 .src_reg = 0, \ 293 .off = 0, \ 294 .imm = 0 }) 295 296 /* Internal classic blocks for direct assignment */ 297 298 #define __BPF_STMT(CODE, K) \ 299 ((struct sock_filter) BPF_STMT(CODE, K)) 300 301 #define __BPF_JUMP(CODE, K, JT, JF) \ 302 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 303 304 #define bytes_to_bpf_size(bytes) \ 305 ({ \ 306 int bpf_size = -EINVAL; \ 307 \ 308 if (bytes == sizeof(u8)) \ 309 bpf_size = BPF_B; \ 310 else if (bytes == sizeof(u16)) \ 311 bpf_size = BPF_H; \ 312 else if (bytes == sizeof(u32)) \ 313 bpf_size = BPF_W; \ 314 else if (bytes == sizeof(u64)) \ 315 bpf_size = BPF_DW; \ 316 \ 317 bpf_size; \ 318 }) 319 320 #define BPF_SIZEOF(type) \ 321 ({ \ 322 const int __size = bytes_to_bpf_size(sizeof(type)); \ 323 BUILD_BUG_ON(__size < 0); \ 324 __size; \ 325 }) 326 327 #define BPF_FIELD_SIZEOF(type, field) \ 328 ({ \ 329 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 330 BUILD_BUG_ON(__size < 0); \ 331 __size; \ 332 }) 333 334 #define __BPF_MAP_0(m, v, ...) v 335 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 336 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 337 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 338 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 339 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 340 341 #define __BPF_REG_0(...) __BPF_PAD(5) 342 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 343 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 344 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 345 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 346 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 347 348 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 349 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 350 351 #define __BPF_CAST(t, a) \ 352 (__force t) \ 353 (__force \ 354 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 355 (unsigned long)0, (t)0))) a 356 #define __BPF_V void 357 #define __BPF_N 358 359 #define __BPF_DECL_ARGS(t, a) t a 360 #define __BPF_DECL_REGS(t, a) u64 a 361 362 #define __BPF_PAD(n) \ 363 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 364 u64, __ur_3, u64, __ur_4, u64, __ur_5) 365 366 #define BPF_CALL_x(x, name, ...) \ 367 static __always_inline \ 368 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 369 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 370 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 371 { \ 372 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 373 } \ 374 static __always_inline \ 375 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 376 377 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 378 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 379 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 380 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 381 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 382 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 383 384 #ifdef CONFIG_COMPAT 385 /* A struct sock_filter is architecture independent. */ 386 struct compat_sock_fprog { 387 u16 len; 388 compat_uptr_t filter; /* struct sock_filter * */ 389 }; 390 #endif 391 392 struct sock_fprog_kern { 393 u16 len; 394 struct sock_filter *filter; 395 }; 396 397 struct bpf_binary_header { 398 unsigned int pages; 399 u8 image[]; 400 }; 401 402 struct bpf_prog { 403 u16 pages; /* Number of allocated pages */ 404 kmemcheck_bitfield_begin(meta); 405 u16 jited:1, /* Is our filter JIT'ed? */ 406 gpl_compatible:1, /* Is filter GPL compatible? */ 407 cb_access:1, /* Is control block accessed? */ 408 dst_needed:1, /* Do we need dst entry? */ 409 xdp_adjust_head:1; /* Adjusting pkt head? */ 410 kmemcheck_bitfield_end(meta); 411 enum bpf_prog_type type; /* Type of BPF program */ 412 u32 len; /* Number of filter blocks */ 413 u8 tag[BPF_TAG_SIZE]; 414 struct bpf_prog_aux *aux; /* Auxiliary fields */ 415 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 416 unsigned int (*bpf_func)(const void *ctx, 417 const struct bpf_insn *insn); 418 /* Instructions for interpreter */ 419 union { 420 struct sock_filter insns[0]; 421 struct bpf_insn insnsi[0]; 422 }; 423 }; 424 425 struct sk_filter { 426 atomic_t refcnt; 427 struct rcu_head rcu; 428 struct bpf_prog *prog; 429 }; 430 431 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 432 433 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 434 435 struct bpf_skb_data_end { 436 struct qdisc_skb_cb qdisc_cb; 437 void *data_end; 438 }; 439 440 struct xdp_buff { 441 void *data; 442 void *data_end; 443 void *data_hard_start; 444 }; 445 446 /* compute the linear packet data range [data, data_end) which 447 * will be accessed by cls_bpf, act_bpf and lwt programs 448 */ 449 static inline void bpf_compute_data_end(struct sk_buff *skb) 450 { 451 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 452 453 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 454 cb->data_end = skb->data + skb_headlen(skb); 455 } 456 457 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 458 { 459 /* eBPF programs may read/write skb->cb[] area to transfer meta 460 * data between tail calls. Since this also needs to work with 461 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 462 * 463 * In some socket filter cases, the cb unfortunately needs to be 464 * saved/restored so that protocol specific skb->cb[] data won't 465 * be lost. In any case, due to unpriviledged eBPF programs 466 * attached to sockets, we need to clear the bpf_skb_cb() area 467 * to not leak previous contents to user space. 468 */ 469 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 470 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 471 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 472 473 return qdisc_skb_cb(skb)->data; 474 } 475 476 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 477 struct sk_buff *skb) 478 { 479 u8 *cb_data = bpf_skb_cb(skb); 480 u8 cb_saved[BPF_SKB_CB_LEN]; 481 u32 res; 482 483 if (unlikely(prog->cb_access)) { 484 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 485 memset(cb_data, 0, sizeof(cb_saved)); 486 } 487 488 res = BPF_PROG_RUN(prog, skb); 489 490 if (unlikely(prog->cb_access)) 491 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 492 493 return res; 494 } 495 496 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 497 struct sk_buff *skb) 498 { 499 u8 *cb_data = bpf_skb_cb(skb); 500 501 if (unlikely(prog->cb_access)) 502 memset(cb_data, 0, BPF_SKB_CB_LEN); 503 504 return BPF_PROG_RUN(prog, skb); 505 } 506 507 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 508 struct xdp_buff *xdp) 509 { 510 /* Caller needs to hold rcu_read_lock() (!), otherwise program 511 * can be released while still running, or map elements could be 512 * freed early while still having concurrent users. XDP fastpath 513 * already takes rcu_read_lock() when fetching the program, so 514 * it's not necessary here anymore. 515 */ 516 return BPF_PROG_RUN(prog, xdp); 517 } 518 519 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 520 { 521 return prog->len * sizeof(struct bpf_insn); 522 } 523 524 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 525 { 526 return round_up(bpf_prog_insn_size(prog) + 527 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 528 } 529 530 static inline unsigned int bpf_prog_size(unsigned int proglen) 531 { 532 return max(sizeof(struct bpf_prog), 533 offsetof(struct bpf_prog, insns[proglen])); 534 } 535 536 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 537 { 538 /* When classic BPF programs have been loaded and the arch 539 * does not have a classic BPF JIT (anymore), they have been 540 * converted via bpf_migrate_filter() to eBPF and thus always 541 * have an unspec program type. 542 */ 543 return prog->type == BPF_PROG_TYPE_UNSPEC; 544 } 545 546 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 547 548 #ifdef CONFIG_DEBUG_SET_MODULE_RONX 549 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 550 { 551 set_memory_ro((unsigned long)fp, fp->pages); 552 } 553 554 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 555 { 556 set_memory_rw((unsigned long)fp, fp->pages); 557 } 558 #else 559 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 560 { 561 } 562 563 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 564 { 565 } 566 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */ 567 568 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 569 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 570 { 571 return sk_filter_trim_cap(sk, skb, 1); 572 } 573 574 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 575 void bpf_prog_free(struct bpf_prog *fp); 576 577 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 578 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 579 gfp_t gfp_extra_flags); 580 void __bpf_prog_free(struct bpf_prog *fp); 581 582 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 583 { 584 bpf_prog_unlock_ro(fp); 585 __bpf_prog_free(fp); 586 } 587 588 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 589 unsigned int flen); 590 591 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 592 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 593 bpf_aux_classic_check_t trans, bool save_orig); 594 void bpf_prog_destroy(struct bpf_prog *fp); 595 596 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 597 int sk_attach_bpf(u32 ufd, struct sock *sk); 598 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 599 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 600 int sk_detach_filter(struct sock *sk); 601 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 602 unsigned int len); 603 604 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 605 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 606 607 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 608 609 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 610 bool bpf_helper_changes_pkt_data(void *func); 611 612 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 613 const struct bpf_insn *patch, u32 len); 614 void bpf_warn_invalid_xdp_action(u32 act); 615 616 #ifdef CONFIG_BPF_JIT 617 extern int bpf_jit_enable; 618 extern int bpf_jit_harden; 619 620 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 621 622 struct bpf_binary_header * 623 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 624 unsigned int alignment, 625 bpf_jit_fill_hole_t bpf_fill_ill_insns); 626 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 627 628 void bpf_jit_compile(struct bpf_prog *fp); 629 void bpf_jit_free(struct bpf_prog *fp); 630 631 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 632 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 633 634 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 635 u32 pass, void *image) 636 { 637 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 638 proglen, pass, image, current->comm, task_pid_nr(current)); 639 640 if (image) 641 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 642 16, 1, image, proglen, false); 643 } 644 645 static inline bool bpf_jit_is_ebpf(void) 646 { 647 # ifdef CONFIG_HAVE_EBPF_JIT 648 return true; 649 # else 650 return false; 651 # endif 652 } 653 654 static inline bool bpf_jit_blinding_enabled(void) 655 { 656 /* These are the prerequisites, should someone ever have the 657 * idea to call blinding outside of them, we make sure to 658 * bail out. 659 */ 660 if (!bpf_jit_is_ebpf()) 661 return false; 662 if (!bpf_jit_enable) 663 return false; 664 if (!bpf_jit_harden) 665 return false; 666 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 667 return false; 668 669 return true; 670 } 671 #else 672 static inline void bpf_jit_compile(struct bpf_prog *fp) 673 { 674 } 675 676 static inline void bpf_jit_free(struct bpf_prog *fp) 677 { 678 bpf_prog_unlock_free(fp); 679 } 680 #endif /* CONFIG_BPF_JIT */ 681 682 #define BPF_ANC BIT(15) 683 684 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 685 { 686 switch (first->code) { 687 case BPF_RET | BPF_K: 688 case BPF_LD | BPF_W | BPF_LEN: 689 return false; 690 691 case BPF_LD | BPF_W | BPF_ABS: 692 case BPF_LD | BPF_H | BPF_ABS: 693 case BPF_LD | BPF_B | BPF_ABS: 694 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 695 return true; 696 return false; 697 698 default: 699 return true; 700 } 701 } 702 703 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 704 { 705 BUG_ON(ftest->code & BPF_ANC); 706 707 switch (ftest->code) { 708 case BPF_LD | BPF_W | BPF_ABS: 709 case BPF_LD | BPF_H | BPF_ABS: 710 case BPF_LD | BPF_B | BPF_ABS: 711 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 712 return BPF_ANC | SKF_AD_##CODE 713 switch (ftest->k) { 714 BPF_ANCILLARY(PROTOCOL); 715 BPF_ANCILLARY(PKTTYPE); 716 BPF_ANCILLARY(IFINDEX); 717 BPF_ANCILLARY(NLATTR); 718 BPF_ANCILLARY(NLATTR_NEST); 719 BPF_ANCILLARY(MARK); 720 BPF_ANCILLARY(QUEUE); 721 BPF_ANCILLARY(HATYPE); 722 BPF_ANCILLARY(RXHASH); 723 BPF_ANCILLARY(CPU); 724 BPF_ANCILLARY(ALU_XOR_X); 725 BPF_ANCILLARY(VLAN_TAG); 726 BPF_ANCILLARY(VLAN_TAG_PRESENT); 727 BPF_ANCILLARY(PAY_OFFSET); 728 BPF_ANCILLARY(RANDOM); 729 BPF_ANCILLARY(VLAN_TPID); 730 } 731 /* Fallthrough. */ 732 default: 733 return ftest->code; 734 } 735 } 736 737 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 738 int k, unsigned int size); 739 740 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 741 unsigned int size, void *buffer) 742 { 743 if (k >= 0) 744 return skb_header_pointer(skb, k, size, buffer); 745 746 return bpf_internal_load_pointer_neg_helper(skb, k, size); 747 } 748 749 static inline int bpf_tell_extensions(void) 750 { 751 return SKF_AD_MAX; 752 } 753 754 #endif /* __LINUX_FILTER_H__ */ 755