1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Linux Socket Filter Data Structures 4 */ 5 #ifndef __LINUX_FILTER_H__ 6 #define __LINUX_FILTER_H__ 7 8 #include <stdarg.h> 9 10 #include <linux/atomic.h> 11 #include <linux/refcount.h> 12 #include <linux/compat.h> 13 #include <linux/skbuff.h> 14 #include <linux/linkage.h> 15 #include <linux/printk.h> 16 #include <linux/workqueue.h> 17 #include <linux/sched.h> 18 #include <linux/capability.h> 19 #include <linux/cryptohash.h> 20 #include <linux/set_memory.h> 21 #include <linux/kallsyms.h> 22 23 #include <net/xdp.h> 24 #include <net/sch_generic.h> 25 26 #include <uapi/linux/filter.h> 27 #include <uapi/linux/bpf.h> 28 29 struct sk_buff; 30 struct sock; 31 struct seccomp_data; 32 struct bpf_prog_aux; 33 34 /* ArgX, context and stack frame pointer register positions. Note, 35 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 36 * calls in BPF_CALL instruction. 37 */ 38 #define BPF_REG_ARG1 BPF_REG_1 39 #define BPF_REG_ARG2 BPF_REG_2 40 #define BPF_REG_ARG3 BPF_REG_3 41 #define BPF_REG_ARG4 BPF_REG_4 42 #define BPF_REG_ARG5 BPF_REG_5 43 #define BPF_REG_CTX BPF_REG_6 44 #define BPF_REG_FP BPF_REG_10 45 46 /* Additional register mappings for converted user programs. */ 47 #define BPF_REG_A BPF_REG_0 48 #define BPF_REG_X BPF_REG_7 49 #define BPF_REG_TMP BPF_REG_8 50 51 /* Kernel hidden auxiliary/helper register for hardening step. 52 * Only used by eBPF JITs. It's nothing more than a temporary 53 * register that JITs use internally, only that here it's part 54 * of eBPF instructions that have been rewritten for blinding 55 * constants. See JIT pre-step in bpf_jit_blind_constants(). 56 */ 57 #define BPF_REG_AX MAX_BPF_REG 58 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 59 60 /* unused opcode to mark special call to bpf_tail_call() helper */ 61 #define BPF_TAIL_CALL 0xf0 62 63 /* unused opcode to mark call to interpreter with arguments */ 64 #define BPF_CALL_ARGS 0xe0 65 66 /* As per nm, we expose JITed images as text (code) section for 67 * kallsyms. That way, tools like perf can find it to match 68 * addresses. 69 */ 70 #define BPF_SYM_ELF_TYPE 't' 71 72 /* BPF program can access up to 512 bytes of stack space. */ 73 #define MAX_BPF_STACK 512 74 75 /* Helper macros for filter block array initializers. */ 76 77 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 78 79 #define BPF_ALU64_REG(OP, DST, SRC) \ 80 ((struct bpf_insn) { \ 81 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 82 .dst_reg = DST, \ 83 .src_reg = SRC, \ 84 .off = 0, \ 85 .imm = 0 }) 86 87 #define BPF_ALU32_REG(OP, DST, SRC) \ 88 ((struct bpf_insn) { \ 89 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 90 .dst_reg = DST, \ 91 .src_reg = SRC, \ 92 .off = 0, \ 93 .imm = 0 }) 94 95 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 96 97 #define BPF_ALU64_IMM(OP, DST, IMM) \ 98 ((struct bpf_insn) { \ 99 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 100 .dst_reg = DST, \ 101 .src_reg = 0, \ 102 .off = 0, \ 103 .imm = IMM }) 104 105 #define BPF_ALU32_IMM(OP, DST, IMM) \ 106 ((struct bpf_insn) { \ 107 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 108 .dst_reg = DST, \ 109 .src_reg = 0, \ 110 .off = 0, \ 111 .imm = IMM }) 112 113 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 114 115 #define BPF_ENDIAN(TYPE, DST, LEN) \ 116 ((struct bpf_insn) { \ 117 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 118 .dst_reg = DST, \ 119 .src_reg = 0, \ 120 .off = 0, \ 121 .imm = LEN }) 122 123 /* Short form of mov, dst_reg = src_reg */ 124 125 #define BPF_MOV64_REG(DST, SRC) \ 126 ((struct bpf_insn) { \ 127 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 128 .dst_reg = DST, \ 129 .src_reg = SRC, \ 130 .off = 0, \ 131 .imm = 0 }) 132 133 #define BPF_MOV32_REG(DST, SRC) \ 134 ((struct bpf_insn) { \ 135 .code = BPF_ALU | BPF_MOV | BPF_X, \ 136 .dst_reg = DST, \ 137 .src_reg = SRC, \ 138 .off = 0, \ 139 .imm = 0 }) 140 141 /* Short form of mov, dst_reg = imm32 */ 142 143 #define BPF_MOV64_IMM(DST, IMM) \ 144 ((struct bpf_insn) { \ 145 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 146 .dst_reg = DST, \ 147 .src_reg = 0, \ 148 .off = 0, \ 149 .imm = IMM }) 150 151 #define BPF_MOV32_IMM(DST, IMM) \ 152 ((struct bpf_insn) { \ 153 .code = BPF_ALU | BPF_MOV | BPF_K, \ 154 .dst_reg = DST, \ 155 .src_reg = 0, \ 156 .off = 0, \ 157 .imm = IMM }) 158 159 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 160 #define BPF_LD_IMM64(DST, IMM) \ 161 BPF_LD_IMM64_RAW(DST, 0, IMM) 162 163 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 164 ((struct bpf_insn) { \ 165 .code = BPF_LD | BPF_DW | BPF_IMM, \ 166 .dst_reg = DST, \ 167 .src_reg = SRC, \ 168 .off = 0, \ 169 .imm = (__u32) (IMM) }), \ 170 ((struct bpf_insn) { \ 171 .code = 0, /* zero is reserved opcode */ \ 172 .dst_reg = 0, \ 173 .src_reg = 0, \ 174 .off = 0, \ 175 .imm = ((__u64) (IMM)) >> 32 }) 176 177 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 178 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 179 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 180 181 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 182 183 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 184 ((struct bpf_insn) { \ 185 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 186 .dst_reg = DST, \ 187 .src_reg = SRC, \ 188 .off = 0, \ 189 .imm = IMM }) 190 191 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 192 ((struct bpf_insn) { \ 193 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 194 .dst_reg = DST, \ 195 .src_reg = SRC, \ 196 .off = 0, \ 197 .imm = IMM }) 198 199 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 200 201 #define BPF_LD_ABS(SIZE, IMM) \ 202 ((struct bpf_insn) { \ 203 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 204 .dst_reg = 0, \ 205 .src_reg = 0, \ 206 .off = 0, \ 207 .imm = IMM }) 208 209 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 210 211 #define BPF_LD_IND(SIZE, SRC, IMM) \ 212 ((struct bpf_insn) { \ 213 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 214 .dst_reg = 0, \ 215 .src_reg = SRC, \ 216 .off = 0, \ 217 .imm = IMM }) 218 219 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 220 221 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 222 ((struct bpf_insn) { \ 223 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 224 .dst_reg = DST, \ 225 .src_reg = SRC, \ 226 .off = OFF, \ 227 .imm = 0 }) 228 229 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 230 231 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 232 ((struct bpf_insn) { \ 233 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 234 .dst_reg = DST, \ 235 .src_reg = SRC, \ 236 .off = OFF, \ 237 .imm = 0 }) 238 239 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 240 241 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 242 ((struct bpf_insn) { \ 243 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 244 .dst_reg = DST, \ 245 .src_reg = SRC, \ 246 .off = OFF, \ 247 .imm = 0 }) 248 249 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 250 251 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 252 ((struct bpf_insn) { \ 253 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 254 .dst_reg = DST, \ 255 .src_reg = 0, \ 256 .off = OFF, \ 257 .imm = IMM }) 258 259 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 260 261 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 262 ((struct bpf_insn) { \ 263 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 264 .dst_reg = DST, \ 265 .src_reg = SRC, \ 266 .off = OFF, \ 267 .imm = 0 }) 268 269 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 270 271 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 272 ((struct bpf_insn) { \ 273 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 274 .dst_reg = DST, \ 275 .src_reg = 0, \ 276 .off = OFF, \ 277 .imm = IMM }) 278 279 /* Unconditional jumps, goto pc + off16 */ 280 281 #define BPF_JMP_A(OFF) \ 282 ((struct bpf_insn) { \ 283 .code = BPF_JMP | BPF_JA, \ 284 .dst_reg = 0, \ 285 .src_reg = 0, \ 286 .off = OFF, \ 287 .imm = 0 }) 288 289 /* Function call */ 290 291 #define BPF_EMIT_CALL(FUNC) \ 292 ((struct bpf_insn) { \ 293 .code = BPF_JMP | BPF_CALL, \ 294 .dst_reg = 0, \ 295 .src_reg = 0, \ 296 .off = 0, \ 297 .imm = ((FUNC) - __bpf_call_base) }) 298 299 /* Raw code statement block */ 300 301 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 302 ((struct bpf_insn) { \ 303 .code = CODE, \ 304 .dst_reg = DST, \ 305 .src_reg = SRC, \ 306 .off = OFF, \ 307 .imm = IMM }) 308 309 /* Program exit */ 310 311 #define BPF_EXIT_INSN() \ 312 ((struct bpf_insn) { \ 313 .code = BPF_JMP | BPF_EXIT, \ 314 .dst_reg = 0, \ 315 .src_reg = 0, \ 316 .off = 0, \ 317 .imm = 0 }) 318 319 /* Internal classic blocks for direct assignment */ 320 321 #define __BPF_STMT(CODE, K) \ 322 ((struct sock_filter) BPF_STMT(CODE, K)) 323 324 #define __BPF_JUMP(CODE, K, JT, JF) \ 325 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 326 327 #define bytes_to_bpf_size(bytes) \ 328 ({ \ 329 int bpf_size = -EINVAL; \ 330 \ 331 if (bytes == sizeof(u8)) \ 332 bpf_size = BPF_B; \ 333 else if (bytes == sizeof(u16)) \ 334 bpf_size = BPF_H; \ 335 else if (bytes == sizeof(u32)) \ 336 bpf_size = BPF_W; \ 337 else if (bytes == sizeof(u64)) \ 338 bpf_size = BPF_DW; \ 339 \ 340 bpf_size; \ 341 }) 342 343 #define bpf_size_to_bytes(bpf_size) \ 344 ({ \ 345 int bytes = -EINVAL; \ 346 \ 347 if (bpf_size == BPF_B) \ 348 bytes = sizeof(u8); \ 349 else if (bpf_size == BPF_H) \ 350 bytes = sizeof(u16); \ 351 else if (bpf_size == BPF_W) \ 352 bytes = sizeof(u32); \ 353 else if (bpf_size == BPF_DW) \ 354 bytes = sizeof(u64); \ 355 \ 356 bytes; \ 357 }) 358 359 #define BPF_SIZEOF(type) \ 360 ({ \ 361 const int __size = bytes_to_bpf_size(sizeof(type)); \ 362 BUILD_BUG_ON(__size < 0); \ 363 __size; \ 364 }) 365 366 #define BPF_FIELD_SIZEOF(type, field) \ 367 ({ \ 368 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 369 BUILD_BUG_ON(__size < 0); \ 370 __size; \ 371 }) 372 373 #define BPF_LDST_BYTES(insn) \ 374 ({ \ 375 const int __size = bpf_size_to_bytes(BPF_SIZE(insn->code)); \ 376 WARN_ON(__size < 0); \ 377 __size; \ 378 }) 379 380 #define __BPF_MAP_0(m, v, ...) v 381 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 382 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 383 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 384 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 385 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 386 387 #define __BPF_REG_0(...) __BPF_PAD(5) 388 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 389 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 390 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 391 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 392 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 393 394 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 395 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 396 397 #define __BPF_CAST(t, a) \ 398 (__force t) \ 399 (__force \ 400 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 401 (unsigned long)0, (t)0))) a 402 #define __BPF_V void 403 #define __BPF_N 404 405 #define __BPF_DECL_ARGS(t, a) t a 406 #define __BPF_DECL_REGS(t, a) u64 a 407 408 #define __BPF_PAD(n) \ 409 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 410 u64, __ur_3, u64, __ur_4, u64, __ur_5) 411 412 #define BPF_CALL_x(x, name, ...) \ 413 static __always_inline \ 414 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 415 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 416 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 417 { \ 418 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 419 } \ 420 static __always_inline \ 421 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 422 423 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 424 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 425 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 426 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 427 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 428 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 429 430 #define bpf_ctx_range(TYPE, MEMBER) \ 431 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 432 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \ 433 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1 434 435 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ 436 ({ \ 437 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \ 438 *(PTR_SIZE) = (SIZE); \ 439 offsetof(TYPE, MEMBER); \ 440 }) 441 442 #ifdef CONFIG_COMPAT 443 /* A struct sock_filter is architecture independent. */ 444 struct compat_sock_fprog { 445 u16 len; 446 compat_uptr_t filter; /* struct sock_filter * */ 447 }; 448 #endif 449 450 struct sock_fprog_kern { 451 u16 len; 452 struct sock_filter *filter; 453 }; 454 455 struct bpf_binary_header { 456 unsigned int pages; 457 u8 image[]; 458 }; 459 460 struct bpf_prog { 461 u16 pages; /* Number of allocated pages */ 462 u16 jited:1, /* Is our filter JIT'ed? */ 463 jit_requested:1,/* archs need to JIT the prog */ 464 locked:1, /* Program image locked? */ 465 gpl_compatible:1, /* Is filter GPL compatible? */ 466 cb_access:1, /* Is control block accessed? */ 467 dst_needed:1, /* Do we need dst entry? */ 468 blinded:1, /* Was blinded */ 469 is_func:1, /* program is a bpf function */ 470 kprobe_override:1; /* Do we override a kprobe? */ 471 enum bpf_prog_type type; /* Type of BPF program */ 472 u32 len; /* Number of filter blocks */ 473 u32 jited_len; /* Size of jited insns in bytes */ 474 u8 tag[BPF_TAG_SIZE]; 475 struct bpf_prog_aux *aux; /* Auxiliary fields */ 476 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 477 unsigned int (*bpf_func)(const void *ctx, 478 const struct bpf_insn *insn); 479 /* Instructions for interpreter */ 480 union { 481 struct sock_filter insns[0]; 482 struct bpf_insn insnsi[0]; 483 }; 484 }; 485 486 struct sk_filter { 487 refcount_t refcnt; 488 struct rcu_head rcu; 489 struct bpf_prog *prog; 490 }; 491 492 #define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi) 493 494 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 495 496 struct bpf_skb_data_end { 497 struct qdisc_skb_cb qdisc_cb; 498 void *data_meta; 499 void *data_end; 500 }; 501 502 struct xdp_buff { 503 void *data; 504 void *data_end; 505 void *data_meta; 506 void *data_hard_start; 507 struct xdp_rxq_info *rxq; 508 }; 509 510 /* Compute the linear packet data range [data, data_end) which 511 * will be accessed by various program types (cls_bpf, act_bpf, 512 * lwt, ...). Subsystems allowing direct data access must (!) 513 * ensure that cb[] area can be written to when BPF program is 514 * invoked (otherwise cb[] save/restore is necessary). 515 */ 516 static inline void bpf_compute_data_pointers(struct sk_buff *skb) 517 { 518 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 519 520 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 521 cb->data_meta = skb->data - skb_metadata_len(skb); 522 cb->data_end = skb->data + skb_headlen(skb); 523 } 524 525 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 526 { 527 /* eBPF programs may read/write skb->cb[] area to transfer meta 528 * data between tail calls. Since this also needs to work with 529 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 530 * 531 * In some socket filter cases, the cb unfortunately needs to be 532 * saved/restored so that protocol specific skb->cb[] data won't 533 * be lost. In any case, due to unpriviledged eBPF programs 534 * attached to sockets, we need to clear the bpf_skb_cb() area 535 * to not leak previous contents to user space. 536 */ 537 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 538 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 539 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 540 541 return qdisc_skb_cb(skb)->data; 542 } 543 544 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 545 struct sk_buff *skb) 546 { 547 u8 *cb_data = bpf_skb_cb(skb); 548 u8 cb_saved[BPF_SKB_CB_LEN]; 549 u32 res; 550 551 if (unlikely(prog->cb_access)) { 552 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 553 memset(cb_data, 0, sizeof(cb_saved)); 554 } 555 556 res = BPF_PROG_RUN(prog, skb); 557 558 if (unlikely(prog->cb_access)) 559 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 560 561 return res; 562 } 563 564 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 565 struct sk_buff *skb) 566 { 567 u8 *cb_data = bpf_skb_cb(skb); 568 569 if (unlikely(prog->cb_access)) 570 memset(cb_data, 0, BPF_SKB_CB_LEN); 571 572 return BPF_PROG_RUN(prog, skb); 573 } 574 575 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 576 struct xdp_buff *xdp) 577 { 578 /* Caller needs to hold rcu_read_lock() (!), otherwise program 579 * can be released while still running, or map elements could be 580 * freed early while still having concurrent users. XDP fastpath 581 * already takes rcu_read_lock() when fetching the program, so 582 * it's not necessary here anymore. 583 */ 584 return BPF_PROG_RUN(prog, xdp); 585 } 586 587 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 588 { 589 return prog->len * sizeof(struct bpf_insn); 590 } 591 592 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 593 { 594 return round_up(bpf_prog_insn_size(prog) + 595 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 596 } 597 598 static inline unsigned int bpf_prog_size(unsigned int proglen) 599 { 600 return max(sizeof(struct bpf_prog), 601 offsetof(struct bpf_prog, insns[proglen])); 602 } 603 604 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 605 { 606 /* When classic BPF programs have been loaded and the arch 607 * does not have a classic BPF JIT (anymore), they have been 608 * converted via bpf_migrate_filter() to eBPF and thus always 609 * have an unspec program type. 610 */ 611 return prog->type == BPF_PROG_TYPE_UNSPEC; 612 } 613 614 static inline bool 615 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default) 616 { 617 bool off_ok; 618 #ifdef __LITTLE_ENDIAN 619 off_ok = (off & (size_default - 1)) == 0; 620 #else 621 off_ok = (off & (size_default - 1)) + size == size_default; 622 #endif 623 return off_ok && size <= size_default && (size & (size - 1)) == 0; 624 } 625 626 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 627 628 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 629 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 630 { 631 fp->locked = 1; 632 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 633 } 634 635 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 636 { 637 if (fp->locked) { 638 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 639 /* In case set_memory_rw() fails, we want to be the first 640 * to crash here instead of some random place later on. 641 */ 642 fp->locked = 0; 643 } 644 } 645 646 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 647 { 648 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 649 } 650 651 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 652 { 653 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 654 } 655 #else 656 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 657 { 658 } 659 660 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 661 { 662 } 663 664 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 665 { 666 } 667 668 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 669 { 670 } 671 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 672 673 static inline struct bpf_binary_header * 674 bpf_jit_binary_hdr(const struct bpf_prog *fp) 675 { 676 unsigned long real_start = (unsigned long)fp->bpf_func; 677 unsigned long addr = real_start & PAGE_MASK; 678 679 return (void *)addr; 680 } 681 682 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 683 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 684 { 685 return sk_filter_trim_cap(sk, skb, 1); 686 } 687 688 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 689 void bpf_prog_free(struct bpf_prog *fp); 690 691 bool bpf_opcode_in_insntable(u8 code); 692 693 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 694 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 695 gfp_t gfp_extra_flags); 696 void __bpf_prog_free(struct bpf_prog *fp); 697 698 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 699 { 700 bpf_prog_unlock_ro(fp); 701 __bpf_prog_free(fp); 702 } 703 704 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 705 unsigned int flen); 706 707 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 708 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 709 bpf_aux_classic_check_t trans, bool save_orig); 710 void bpf_prog_destroy(struct bpf_prog *fp); 711 712 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 713 int sk_attach_bpf(u32 ufd, struct sock *sk); 714 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 715 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 716 int sk_detach_filter(struct sock *sk); 717 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 718 unsigned int len); 719 720 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 721 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 722 723 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 724 #define __bpf_call_base_args \ 725 ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \ 726 __bpf_call_base) 727 728 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 729 void bpf_jit_compile(struct bpf_prog *prog); 730 bool bpf_helper_changes_pkt_data(void *func); 731 732 static inline bool bpf_dump_raw_ok(void) 733 { 734 /* Reconstruction of call-sites is dependent on kallsyms, 735 * thus make dump the same restriction. 736 */ 737 return kallsyms_show_value() == 1; 738 } 739 740 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 741 const struct bpf_insn *patch, u32 len); 742 743 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the 744 * same cpu context. Further for best results no more than a single map 745 * for the do_redirect/do_flush pair should be used. This limitation is 746 * because we only track one map and force a flush when the map changes. 747 * This does not appear to be a real limitation for existing software. 748 */ 749 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, 750 struct bpf_prog *prog); 751 int xdp_do_redirect(struct net_device *dev, 752 struct xdp_buff *xdp, 753 struct bpf_prog *prog); 754 void xdp_do_flush_map(void); 755 756 /* Drivers not supporting XDP metadata can use this helper, which 757 * rejects any room expansion for metadata as a result. 758 */ 759 static __always_inline void 760 xdp_set_data_meta_invalid(struct xdp_buff *xdp) 761 { 762 xdp->data_meta = xdp->data + 1; 763 } 764 765 static __always_inline bool 766 xdp_data_meta_unsupported(const struct xdp_buff *xdp) 767 { 768 return unlikely(xdp->data_meta > xdp->data); 769 } 770 771 void bpf_warn_invalid_xdp_action(u32 act); 772 773 struct sock *do_sk_redirect_map(struct sk_buff *skb); 774 775 #ifdef CONFIG_BPF_JIT 776 extern int bpf_jit_enable; 777 extern int bpf_jit_harden; 778 extern int bpf_jit_kallsyms; 779 780 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 781 782 struct bpf_binary_header * 783 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 784 unsigned int alignment, 785 bpf_jit_fill_hole_t bpf_fill_ill_insns); 786 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 787 788 void bpf_jit_free(struct bpf_prog *fp); 789 790 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 791 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 792 793 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 794 u32 pass, void *image) 795 { 796 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 797 proglen, pass, image, current->comm, task_pid_nr(current)); 798 799 if (image) 800 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 801 16, 1, image, proglen, false); 802 } 803 804 static inline bool bpf_jit_is_ebpf(void) 805 { 806 # ifdef CONFIG_HAVE_EBPF_JIT 807 return true; 808 # else 809 return false; 810 # endif 811 } 812 813 static inline bool ebpf_jit_enabled(void) 814 { 815 return bpf_jit_enable && bpf_jit_is_ebpf(); 816 } 817 818 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 819 { 820 return fp->jited && bpf_jit_is_ebpf(); 821 } 822 823 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) 824 { 825 /* These are the prerequisites, should someone ever have the 826 * idea to call blinding outside of them, we make sure to 827 * bail out. 828 */ 829 if (!bpf_jit_is_ebpf()) 830 return false; 831 if (!prog->jit_requested) 832 return false; 833 if (!bpf_jit_harden) 834 return false; 835 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 836 return false; 837 838 return true; 839 } 840 841 static inline bool bpf_jit_kallsyms_enabled(void) 842 { 843 /* There are a couple of corner cases where kallsyms should 844 * not be enabled f.e. on hardening. 845 */ 846 if (bpf_jit_harden) 847 return false; 848 if (!bpf_jit_kallsyms) 849 return false; 850 if (bpf_jit_kallsyms == 1) 851 return true; 852 853 return false; 854 } 855 856 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 857 unsigned long *off, char *sym); 858 bool is_bpf_text_address(unsigned long addr); 859 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 860 char *sym); 861 862 static inline const char * 863 bpf_address_lookup(unsigned long addr, unsigned long *size, 864 unsigned long *off, char **modname, char *sym) 865 { 866 const char *ret = __bpf_address_lookup(addr, size, off, sym); 867 868 if (ret && modname) 869 *modname = NULL; 870 return ret; 871 } 872 873 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 874 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 875 876 #else /* CONFIG_BPF_JIT */ 877 878 static inline bool ebpf_jit_enabled(void) 879 { 880 return false; 881 } 882 883 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 884 { 885 return false; 886 } 887 888 static inline void bpf_jit_free(struct bpf_prog *fp) 889 { 890 bpf_prog_unlock_free(fp); 891 } 892 893 static inline bool bpf_jit_kallsyms_enabled(void) 894 { 895 return false; 896 } 897 898 static inline const char * 899 __bpf_address_lookup(unsigned long addr, unsigned long *size, 900 unsigned long *off, char *sym) 901 { 902 return NULL; 903 } 904 905 static inline bool is_bpf_text_address(unsigned long addr) 906 { 907 return false; 908 } 909 910 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 911 char *type, char *sym) 912 { 913 return -ERANGE; 914 } 915 916 static inline const char * 917 bpf_address_lookup(unsigned long addr, unsigned long *size, 918 unsigned long *off, char **modname, char *sym) 919 { 920 return NULL; 921 } 922 923 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 924 { 925 } 926 927 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 928 { 929 } 930 #endif /* CONFIG_BPF_JIT */ 931 932 #define BPF_ANC BIT(15) 933 934 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 935 { 936 switch (first->code) { 937 case BPF_RET | BPF_K: 938 case BPF_LD | BPF_W | BPF_LEN: 939 return false; 940 941 case BPF_LD | BPF_W | BPF_ABS: 942 case BPF_LD | BPF_H | BPF_ABS: 943 case BPF_LD | BPF_B | BPF_ABS: 944 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 945 return true; 946 return false; 947 948 default: 949 return true; 950 } 951 } 952 953 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 954 { 955 BUG_ON(ftest->code & BPF_ANC); 956 957 switch (ftest->code) { 958 case BPF_LD | BPF_W | BPF_ABS: 959 case BPF_LD | BPF_H | BPF_ABS: 960 case BPF_LD | BPF_B | BPF_ABS: 961 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 962 return BPF_ANC | SKF_AD_##CODE 963 switch (ftest->k) { 964 BPF_ANCILLARY(PROTOCOL); 965 BPF_ANCILLARY(PKTTYPE); 966 BPF_ANCILLARY(IFINDEX); 967 BPF_ANCILLARY(NLATTR); 968 BPF_ANCILLARY(NLATTR_NEST); 969 BPF_ANCILLARY(MARK); 970 BPF_ANCILLARY(QUEUE); 971 BPF_ANCILLARY(HATYPE); 972 BPF_ANCILLARY(RXHASH); 973 BPF_ANCILLARY(CPU); 974 BPF_ANCILLARY(ALU_XOR_X); 975 BPF_ANCILLARY(VLAN_TAG); 976 BPF_ANCILLARY(VLAN_TAG_PRESENT); 977 BPF_ANCILLARY(PAY_OFFSET); 978 BPF_ANCILLARY(RANDOM); 979 BPF_ANCILLARY(VLAN_TPID); 980 } 981 /* Fallthrough. */ 982 default: 983 return ftest->code; 984 } 985 } 986 987 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 988 int k, unsigned int size); 989 990 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 991 unsigned int size, void *buffer) 992 { 993 if (k >= 0) 994 return skb_header_pointer(skb, k, size, buffer); 995 996 return bpf_internal_load_pointer_neg_helper(skb, k, size); 997 } 998 999 static inline int bpf_tell_extensions(void) 1000 { 1001 return SKF_AD_MAX; 1002 } 1003 1004 struct bpf_sock_ops_kern { 1005 struct sock *sk; 1006 u32 op; 1007 union { 1008 u32 args[4]; 1009 u32 reply; 1010 u32 replylong[4]; 1011 }; 1012 u32 is_fullsock; 1013 u64 temp; /* temp and everything after is not 1014 * initialized to 0 before calling 1015 * the BPF program. New fields that 1016 * should be initialized to 0 should 1017 * be inserted before temp. 1018 * temp is scratch storage used by 1019 * sock_ops_convert_ctx_access 1020 * as temporary storage of a register. 1021 */ 1022 }; 1023 1024 #endif /* __LINUX_FILTER_H__ */ 1025