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/refcount.h> 11 #include <linux/compat.h> 12 #include <linux/skbuff.h> 13 #include <linux/linkage.h> 14 #include <linux/printk.h> 15 #include <linux/workqueue.h> 16 #include <linux/sched.h> 17 #include <linux/capability.h> 18 #include <linux/cryptohash.h> 19 #include <linux/set_memory.h> 20 21 #include <net/sch_generic.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 /* unused opcode to mark special call to bpf_tail_call() helper */ 58 #define BPF_TAIL_CALL 0xf0 59 60 /* As per nm, we expose JITed images as text (code) section for 61 * kallsyms. That way, tools like perf can find it to match 62 * addresses. 63 */ 64 #define BPF_SYM_ELF_TYPE 't' 65 66 /* BPF program can access up to 512 bytes of stack space. */ 67 #define MAX_BPF_STACK 512 68 69 /* Helper macros for filter block array initializers. */ 70 71 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 72 73 #define BPF_ALU64_REG(OP, DST, SRC) \ 74 ((struct bpf_insn) { \ 75 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 76 .dst_reg = DST, \ 77 .src_reg = SRC, \ 78 .off = 0, \ 79 .imm = 0 }) 80 81 #define BPF_ALU32_REG(OP, DST, SRC) \ 82 ((struct bpf_insn) { \ 83 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 84 .dst_reg = DST, \ 85 .src_reg = SRC, \ 86 .off = 0, \ 87 .imm = 0 }) 88 89 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 90 91 #define BPF_ALU64_IMM(OP, DST, IMM) \ 92 ((struct bpf_insn) { \ 93 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 94 .dst_reg = DST, \ 95 .src_reg = 0, \ 96 .off = 0, \ 97 .imm = IMM }) 98 99 #define BPF_ALU32_IMM(OP, DST, IMM) \ 100 ((struct bpf_insn) { \ 101 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 102 .dst_reg = DST, \ 103 .src_reg = 0, \ 104 .off = 0, \ 105 .imm = IMM }) 106 107 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 108 109 #define BPF_ENDIAN(TYPE, DST, LEN) \ 110 ((struct bpf_insn) { \ 111 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 112 .dst_reg = DST, \ 113 .src_reg = 0, \ 114 .off = 0, \ 115 .imm = LEN }) 116 117 /* Short form of mov, dst_reg = src_reg */ 118 119 #define BPF_MOV64_REG(DST, SRC) \ 120 ((struct bpf_insn) { \ 121 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 122 .dst_reg = DST, \ 123 .src_reg = SRC, \ 124 .off = 0, \ 125 .imm = 0 }) 126 127 #define BPF_MOV32_REG(DST, SRC) \ 128 ((struct bpf_insn) { \ 129 .code = BPF_ALU | BPF_MOV | BPF_X, \ 130 .dst_reg = DST, \ 131 .src_reg = SRC, \ 132 .off = 0, \ 133 .imm = 0 }) 134 135 /* Short form of mov, dst_reg = imm32 */ 136 137 #define BPF_MOV64_IMM(DST, IMM) \ 138 ((struct bpf_insn) { \ 139 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 140 .dst_reg = DST, \ 141 .src_reg = 0, \ 142 .off = 0, \ 143 .imm = IMM }) 144 145 #define BPF_MOV32_IMM(DST, IMM) \ 146 ((struct bpf_insn) { \ 147 .code = BPF_ALU | BPF_MOV | BPF_K, \ 148 .dst_reg = DST, \ 149 .src_reg = 0, \ 150 .off = 0, \ 151 .imm = IMM }) 152 153 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 154 #define BPF_LD_IMM64(DST, IMM) \ 155 BPF_LD_IMM64_RAW(DST, 0, IMM) 156 157 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 158 ((struct bpf_insn) { \ 159 .code = BPF_LD | BPF_DW | BPF_IMM, \ 160 .dst_reg = DST, \ 161 .src_reg = SRC, \ 162 .off = 0, \ 163 .imm = (__u32) (IMM) }), \ 164 ((struct bpf_insn) { \ 165 .code = 0, /* zero is reserved opcode */ \ 166 .dst_reg = 0, \ 167 .src_reg = 0, \ 168 .off = 0, \ 169 .imm = ((__u64) (IMM)) >> 32 }) 170 171 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 172 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 173 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 174 175 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 176 177 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 178 ((struct bpf_insn) { \ 179 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 180 .dst_reg = DST, \ 181 .src_reg = SRC, \ 182 .off = 0, \ 183 .imm = IMM }) 184 185 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 186 ((struct bpf_insn) { \ 187 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 188 .dst_reg = DST, \ 189 .src_reg = SRC, \ 190 .off = 0, \ 191 .imm = IMM }) 192 193 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 194 195 #define BPF_LD_ABS(SIZE, IMM) \ 196 ((struct bpf_insn) { \ 197 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 198 .dst_reg = 0, \ 199 .src_reg = 0, \ 200 .off = 0, \ 201 .imm = IMM }) 202 203 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 204 205 #define BPF_LD_IND(SIZE, SRC, IMM) \ 206 ((struct bpf_insn) { \ 207 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 208 .dst_reg = 0, \ 209 .src_reg = SRC, \ 210 .off = 0, \ 211 .imm = IMM }) 212 213 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 214 215 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 216 ((struct bpf_insn) { \ 217 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 218 .dst_reg = DST, \ 219 .src_reg = SRC, \ 220 .off = OFF, \ 221 .imm = 0 }) 222 223 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 224 225 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 226 ((struct bpf_insn) { \ 227 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 228 .dst_reg = DST, \ 229 .src_reg = SRC, \ 230 .off = OFF, \ 231 .imm = 0 }) 232 233 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 234 235 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 236 ((struct bpf_insn) { \ 237 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 238 .dst_reg = DST, \ 239 .src_reg = SRC, \ 240 .off = OFF, \ 241 .imm = 0 }) 242 243 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 244 245 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 246 ((struct bpf_insn) { \ 247 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 248 .dst_reg = DST, \ 249 .src_reg = 0, \ 250 .off = OFF, \ 251 .imm = IMM }) 252 253 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 254 255 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 256 ((struct bpf_insn) { \ 257 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 258 .dst_reg = DST, \ 259 .src_reg = SRC, \ 260 .off = OFF, \ 261 .imm = 0 }) 262 263 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 264 265 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 266 ((struct bpf_insn) { \ 267 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 268 .dst_reg = DST, \ 269 .src_reg = 0, \ 270 .off = OFF, \ 271 .imm = IMM }) 272 273 /* Unconditional jumps, goto pc + off16 */ 274 275 #define BPF_JMP_A(OFF) \ 276 ((struct bpf_insn) { \ 277 .code = BPF_JMP | BPF_JA, \ 278 .dst_reg = 0, \ 279 .src_reg = 0, \ 280 .off = OFF, \ 281 .imm = 0 }) 282 283 /* Function call */ 284 285 #define BPF_EMIT_CALL(FUNC) \ 286 ((struct bpf_insn) { \ 287 .code = BPF_JMP | BPF_CALL, \ 288 .dst_reg = 0, \ 289 .src_reg = 0, \ 290 .off = 0, \ 291 .imm = ((FUNC) - __bpf_call_base) }) 292 293 /* Raw code statement block */ 294 295 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 296 ((struct bpf_insn) { \ 297 .code = CODE, \ 298 .dst_reg = DST, \ 299 .src_reg = SRC, \ 300 .off = OFF, \ 301 .imm = IMM }) 302 303 /* Program exit */ 304 305 #define BPF_EXIT_INSN() \ 306 ((struct bpf_insn) { \ 307 .code = BPF_JMP | BPF_EXIT, \ 308 .dst_reg = 0, \ 309 .src_reg = 0, \ 310 .off = 0, \ 311 .imm = 0 }) 312 313 /* Internal classic blocks for direct assignment */ 314 315 #define __BPF_STMT(CODE, K) \ 316 ((struct sock_filter) BPF_STMT(CODE, K)) 317 318 #define __BPF_JUMP(CODE, K, JT, JF) \ 319 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 320 321 #define bytes_to_bpf_size(bytes) \ 322 ({ \ 323 int bpf_size = -EINVAL; \ 324 \ 325 if (bytes == sizeof(u8)) \ 326 bpf_size = BPF_B; \ 327 else if (bytes == sizeof(u16)) \ 328 bpf_size = BPF_H; \ 329 else if (bytes == sizeof(u32)) \ 330 bpf_size = BPF_W; \ 331 else if (bytes == sizeof(u64)) \ 332 bpf_size = BPF_DW; \ 333 \ 334 bpf_size; \ 335 }) 336 337 #define bpf_size_to_bytes(bpf_size) \ 338 ({ \ 339 int bytes = -EINVAL; \ 340 \ 341 if (bpf_size == BPF_B) \ 342 bytes = sizeof(u8); \ 343 else if (bpf_size == BPF_H) \ 344 bytes = sizeof(u16); \ 345 else if (bpf_size == BPF_W) \ 346 bytes = sizeof(u32); \ 347 else if (bpf_size == BPF_DW) \ 348 bytes = sizeof(u64); \ 349 \ 350 bytes; \ 351 }) 352 353 #define BPF_SIZEOF(type) \ 354 ({ \ 355 const int __size = bytes_to_bpf_size(sizeof(type)); \ 356 BUILD_BUG_ON(__size < 0); \ 357 __size; \ 358 }) 359 360 #define BPF_FIELD_SIZEOF(type, field) \ 361 ({ \ 362 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 363 BUILD_BUG_ON(__size < 0); \ 364 __size; \ 365 }) 366 367 #define BPF_LDST_BYTES(insn) \ 368 ({ \ 369 const int __size = bpf_size_to_bytes(BPF_SIZE(insn->code)); \ 370 WARN_ON(__size < 0); \ 371 __size; \ 372 }) 373 374 #define __BPF_MAP_0(m, v, ...) v 375 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 376 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 377 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 378 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 379 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 380 381 #define __BPF_REG_0(...) __BPF_PAD(5) 382 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 383 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 384 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 385 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 386 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 387 388 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 389 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 390 391 #define __BPF_CAST(t, a) \ 392 (__force t) \ 393 (__force \ 394 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 395 (unsigned long)0, (t)0))) a 396 #define __BPF_V void 397 #define __BPF_N 398 399 #define __BPF_DECL_ARGS(t, a) t a 400 #define __BPF_DECL_REGS(t, a) u64 a 401 402 #define __BPF_PAD(n) \ 403 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 404 u64, __ur_3, u64, __ur_4, u64, __ur_5) 405 406 #define BPF_CALL_x(x, name, ...) \ 407 static __always_inline \ 408 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 409 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 410 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 411 { \ 412 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 413 } \ 414 static __always_inline \ 415 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 416 417 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 418 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 419 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 420 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 421 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 422 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 423 424 #define bpf_ctx_range(TYPE, MEMBER) \ 425 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 426 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \ 427 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1 428 429 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ 430 ({ \ 431 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \ 432 *(PTR_SIZE) = (SIZE); \ 433 offsetof(TYPE, MEMBER); \ 434 }) 435 436 #ifdef CONFIG_COMPAT 437 /* A struct sock_filter is architecture independent. */ 438 struct compat_sock_fprog { 439 u16 len; 440 compat_uptr_t filter; /* struct sock_filter * */ 441 }; 442 #endif 443 444 struct sock_fprog_kern { 445 u16 len; 446 struct sock_filter *filter; 447 }; 448 449 struct bpf_binary_header { 450 unsigned int pages; 451 u8 image[]; 452 }; 453 454 struct bpf_prog { 455 u16 pages; /* Number of allocated pages */ 456 kmemcheck_bitfield_begin(meta); 457 u16 jited:1, /* Is our filter JIT'ed? */ 458 locked:1, /* Program image locked? */ 459 gpl_compatible:1, /* Is filter GPL compatible? */ 460 cb_access:1, /* Is control block accessed? */ 461 dst_needed:1; /* Do we need dst entry? */ 462 kmemcheck_bitfield_end(meta); 463 enum bpf_prog_type type; /* Type of BPF program */ 464 u32 len; /* Number of filter blocks */ 465 u32 jited_len; /* Size of jited insns in bytes */ 466 u8 tag[BPF_TAG_SIZE]; 467 struct bpf_prog_aux *aux; /* Auxiliary fields */ 468 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 469 unsigned int (*bpf_func)(const void *ctx, 470 const struct bpf_insn *insn); 471 /* Instructions for interpreter */ 472 union { 473 struct sock_filter insns[0]; 474 struct bpf_insn insnsi[0]; 475 }; 476 }; 477 478 struct sk_filter { 479 refcount_t refcnt; 480 struct rcu_head rcu; 481 struct bpf_prog *prog; 482 }; 483 484 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 485 486 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 487 488 struct bpf_skb_data_end { 489 struct qdisc_skb_cb qdisc_cb; 490 void *data_end; 491 }; 492 493 struct xdp_buff { 494 void *data; 495 void *data_end; 496 void *data_hard_start; 497 }; 498 499 /* compute the linear packet data range [data, data_end) which 500 * will be accessed by cls_bpf, act_bpf and lwt programs 501 */ 502 static inline void bpf_compute_data_end(struct sk_buff *skb) 503 { 504 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 505 506 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 507 cb->data_end = skb->data + skb_headlen(skb); 508 } 509 510 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 511 { 512 /* eBPF programs may read/write skb->cb[] area to transfer meta 513 * data between tail calls. Since this also needs to work with 514 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 515 * 516 * In some socket filter cases, the cb unfortunately needs to be 517 * saved/restored so that protocol specific skb->cb[] data won't 518 * be lost. In any case, due to unpriviledged eBPF programs 519 * attached to sockets, we need to clear the bpf_skb_cb() area 520 * to not leak previous contents to user space. 521 */ 522 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 523 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 524 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 525 526 return qdisc_skb_cb(skb)->data; 527 } 528 529 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 530 struct sk_buff *skb) 531 { 532 u8 *cb_data = bpf_skb_cb(skb); 533 u8 cb_saved[BPF_SKB_CB_LEN]; 534 u32 res; 535 536 if (unlikely(prog->cb_access)) { 537 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 538 memset(cb_data, 0, sizeof(cb_saved)); 539 } 540 541 res = BPF_PROG_RUN(prog, skb); 542 543 if (unlikely(prog->cb_access)) 544 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 545 546 return res; 547 } 548 549 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 550 struct sk_buff *skb) 551 { 552 u8 *cb_data = bpf_skb_cb(skb); 553 554 if (unlikely(prog->cb_access)) 555 memset(cb_data, 0, BPF_SKB_CB_LEN); 556 557 return BPF_PROG_RUN(prog, skb); 558 } 559 560 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 561 struct xdp_buff *xdp) 562 { 563 /* Caller needs to hold rcu_read_lock() (!), otherwise program 564 * can be released while still running, or map elements could be 565 * freed early while still having concurrent users. XDP fastpath 566 * already takes rcu_read_lock() when fetching the program, so 567 * it's not necessary here anymore. 568 */ 569 return BPF_PROG_RUN(prog, xdp); 570 } 571 572 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 573 { 574 return prog->len * sizeof(struct bpf_insn); 575 } 576 577 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 578 { 579 return round_up(bpf_prog_insn_size(prog) + 580 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 581 } 582 583 static inline unsigned int bpf_prog_size(unsigned int proglen) 584 { 585 return max(sizeof(struct bpf_prog), 586 offsetof(struct bpf_prog, insns[proglen])); 587 } 588 589 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 590 { 591 /* When classic BPF programs have been loaded and the arch 592 * does not have a classic BPF JIT (anymore), they have been 593 * converted via bpf_migrate_filter() to eBPF and thus always 594 * have an unspec program type. 595 */ 596 return prog->type == BPF_PROG_TYPE_UNSPEC; 597 } 598 599 static inline bool 600 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default) 601 { 602 bool off_ok; 603 #ifdef __LITTLE_ENDIAN 604 off_ok = (off & (size_default - 1)) == 0; 605 #else 606 off_ok = (off & (size_default - 1)) + size == size_default; 607 #endif 608 return off_ok && size <= size_default && (size & (size - 1)) == 0; 609 } 610 611 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 612 613 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 614 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 615 { 616 fp->locked = 1; 617 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 618 } 619 620 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 621 { 622 if (fp->locked) { 623 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 624 /* In case set_memory_rw() fails, we want to be the first 625 * to crash here instead of some random place later on. 626 */ 627 fp->locked = 0; 628 } 629 } 630 631 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 632 { 633 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 634 } 635 636 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 637 { 638 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 639 } 640 #else 641 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 642 { 643 } 644 645 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 646 { 647 } 648 649 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 650 { 651 } 652 653 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 654 { 655 } 656 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 657 658 static inline struct bpf_binary_header * 659 bpf_jit_binary_hdr(const struct bpf_prog *fp) 660 { 661 unsigned long real_start = (unsigned long)fp->bpf_func; 662 unsigned long addr = real_start & PAGE_MASK; 663 664 return (void *)addr; 665 } 666 667 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 668 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 669 { 670 return sk_filter_trim_cap(sk, skb, 1); 671 } 672 673 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 674 void bpf_prog_free(struct bpf_prog *fp); 675 676 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 677 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 678 gfp_t gfp_extra_flags); 679 void __bpf_prog_free(struct bpf_prog *fp); 680 681 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 682 { 683 bpf_prog_unlock_ro(fp); 684 __bpf_prog_free(fp); 685 } 686 687 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 688 unsigned int flen); 689 690 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 691 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 692 bpf_aux_classic_check_t trans, bool save_orig); 693 void bpf_prog_destroy(struct bpf_prog *fp); 694 695 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 696 int sk_attach_bpf(u32 ufd, struct sock *sk); 697 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 698 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 699 int sk_detach_filter(struct sock *sk); 700 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 701 unsigned int len); 702 703 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 704 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 705 706 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 707 708 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 709 void bpf_jit_compile(struct bpf_prog *prog); 710 bool bpf_helper_changes_pkt_data(void *func); 711 712 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 713 const struct bpf_insn *patch, u32 len); 714 715 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the 716 * same cpu context. Further for best results no more than a single map 717 * for the do_redirect/do_flush pair should be used. This limitation is 718 * because we only track one map and force a flush when the map changes. 719 * This does not appear to be a real limitation for existing software. 720 */ 721 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb); 722 int xdp_do_redirect(struct net_device *dev, 723 struct xdp_buff *xdp, 724 struct bpf_prog *prog); 725 void xdp_do_flush_map(void); 726 727 void bpf_warn_invalid_xdp_action(u32 act); 728 void bpf_warn_invalid_xdp_redirect(u32 ifindex); 729 730 #ifdef CONFIG_BPF_JIT 731 extern int bpf_jit_enable; 732 extern int bpf_jit_harden; 733 extern int bpf_jit_kallsyms; 734 735 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 736 737 struct bpf_binary_header * 738 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 739 unsigned int alignment, 740 bpf_jit_fill_hole_t bpf_fill_ill_insns); 741 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 742 743 void bpf_jit_free(struct bpf_prog *fp); 744 745 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 746 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 747 748 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 749 u32 pass, void *image) 750 { 751 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 752 proglen, pass, image, current->comm, task_pid_nr(current)); 753 754 if (image) 755 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 756 16, 1, image, proglen, false); 757 } 758 759 static inline bool bpf_jit_is_ebpf(void) 760 { 761 # ifdef CONFIG_HAVE_EBPF_JIT 762 return true; 763 # else 764 return false; 765 # endif 766 } 767 768 static inline bool ebpf_jit_enabled(void) 769 { 770 return bpf_jit_enable && bpf_jit_is_ebpf(); 771 } 772 773 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 774 { 775 return fp->jited && bpf_jit_is_ebpf(); 776 } 777 778 static inline bool bpf_jit_blinding_enabled(void) 779 { 780 /* These are the prerequisites, should someone ever have the 781 * idea to call blinding outside of them, we make sure to 782 * bail out. 783 */ 784 if (!bpf_jit_is_ebpf()) 785 return false; 786 if (!bpf_jit_enable) 787 return false; 788 if (!bpf_jit_harden) 789 return false; 790 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 791 return false; 792 793 return true; 794 } 795 796 static inline bool bpf_jit_kallsyms_enabled(void) 797 { 798 /* There are a couple of corner cases where kallsyms should 799 * not be enabled f.e. on hardening. 800 */ 801 if (bpf_jit_harden) 802 return false; 803 if (!bpf_jit_kallsyms) 804 return false; 805 if (bpf_jit_kallsyms == 1) 806 return true; 807 808 return false; 809 } 810 811 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 812 unsigned long *off, char *sym); 813 bool is_bpf_text_address(unsigned long addr); 814 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 815 char *sym); 816 817 static inline const char * 818 bpf_address_lookup(unsigned long addr, unsigned long *size, 819 unsigned long *off, char **modname, char *sym) 820 { 821 const char *ret = __bpf_address_lookup(addr, size, off, sym); 822 823 if (ret && modname) 824 *modname = NULL; 825 return ret; 826 } 827 828 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 829 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 830 831 #else /* CONFIG_BPF_JIT */ 832 833 static inline bool ebpf_jit_enabled(void) 834 { 835 return false; 836 } 837 838 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 839 { 840 return false; 841 } 842 843 static inline void bpf_jit_free(struct bpf_prog *fp) 844 { 845 bpf_prog_unlock_free(fp); 846 } 847 848 static inline bool bpf_jit_kallsyms_enabled(void) 849 { 850 return false; 851 } 852 853 static inline const char * 854 __bpf_address_lookup(unsigned long addr, unsigned long *size, 855 unsigned long *off, char *sym) 856 { 857 return NULL; 858 } 859 860 static inline bool is_bpf_text_address(unsigned long addr) 861 { 862 return false; 863 } 864 865 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 866 char *type, char *sym) 867 { 868 return -ERANGE; 869 } 870 871 static inline const char * 872 bpf_address_lookup(unsigned long addr, unsigned long *size, 873 unsigned long *off, char **modname, char *sym) 874 { 875 return NULL; 876 } 877 878 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 879 { 880 } 881 882 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 883 { 884 } 885 #endif /* CONFIG_BPF_JIT */ 886 887 #define BPF_ANC BIT(15) 888 889 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 890 { 891 switch (first->code) { 892 case BPF_RET | BPF_K: 893 case BPF_LD | BPF_W | BPF_LEN: 894 return false; 895 896 case BPF_LD | BPF_W | BPF_ABS: 897 case BPF_LD | BPF_H | BPF_ABS: 898 case BPF_LD | BPF_B | BPF_ABS: 899 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 900 return true; 901 return false; 902 903 default: 904 return true; 905 } 906 } 907 908 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 909 { 910 BUG_ON(ftest->code & BPF_ANC); 911 912 switch (ftest->code) { 913 case BPF_LD | BPF_W | BPF_ABS: 914 case BPF_LD | BPF_H | BPF_ABS: 915 case BPF_LD | BPF_B | BPF_ABS: 916 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 917 return BPF_ANC | SKF_AD_##CODE 918 switch (ftest->k) { 919 BPF_ANCILLARY(PROTOCOL); 920 BPF_ANCILLARY(PKTTYPE); 921 BPF_ANCILLARY(IFINDEX); 922 BPF_ANCILLARY(NLATTR); 923 BPF_ANCILLARY(NLATTR_NEST); 924 BPF_ANCILLARY(MARK); 925 BPF_ANCILLARY(QUEUE); 926 BPF_ANCILLARY(HATYPE); 927 BPF_ANCILLARY(RXHASH); 928 BPF_ANCILLARY(CPU); 929 BPF_ANCILLARY(ALU_XOR_X); 930 BPF_ANCILLARY(VLAN_TAG); 931 BPF_ANCILLARY(VLAN_TAG_PRESENT); 932 BPF_ANCILLARY(PAY_OFFSET); 933 BPF_ANCILLARY(RANDOM); 934 BPF_ANCILLARY(VLAN_TPID); 935 } 936 /* Fallthrough. */ 937 default: 938 return ftest->code; 939 } 940 } 941 942 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 943 int k, unsigned int size); 944 945 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 946 unsigned int size, void *buffer) 947 { 948 if (k >= 0) 949 return skb_header_pointer(skb, k, size, buffer); 950 951 return bpf_internal_load_pointer_neg_helper(skb, k, size); 952 } 953 954 static inline int bpf_tell_extensions(void) 955 { 956 return SKF_AD_MAX; 957 } 958 959 struct bpf_sock_ops_kern { 960 struct sock *sk; 961 u32 op; 962 union { 963 u32 reply; 964 u32 replylong[4]; 965 }; 966 }; 967 968 #endif /* __LINUX_FILTER_H__ */ 969