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/sch_generic.h> 24 25 #include <uapi/linux/filter.h> 26 #include <uapi/linux/bpf.h> 27 28 struct sk_buff; 29 struct sock; 30 struct seccomp_data; 31 struct bpf_prog_aux; 32 struct xdp_rxq_info; 33 struct xdp_buff; 34 35 /* ArgX, context and stack frame pointer register positions. Note, 36 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 37 * calls in BPF_CALL instruction. 38 */ 39 #define BPF_REG_ARG1 BPF_REG_1 40 #define BPF_REG_ARG2 BPF_REG_2 41 #define BPF_REG_ARG3 BPF_REG_3 42 #define BPF_REG_ARG4 BPF_REG_4 43 #define BPF_REG_ARG5 BPF_REG_5 44 #define BPF_REG_CTX BPF_REG_6 45 #define BPF_REG_FP BPF_REG_10 46 47 /* Additional register mappings for converted user programs. */ 48 #define BPF_REG_A BPF_REG_0 49 #define BPF_REG_X BPF_REG_7 50 #define BPF_REG_TMP BPF_REG_8 51 52 /* Kernel hidden auxiliary/helper register for hardening step. 53 * Only used by eBPF JITs. It's nothing more than a temporary 54 * register that JITs use internally, only that here it's part 55 * of eBPF instructions that have been rewritten for blinding 56 * constants. See JIT pre-step in bpf_jit_blind_constants(). 57 */ 58 #define BPF_REG_AX MAX_BPF_REG 59 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 60 61 /* unused opcode to mark special call to bpf_tail_call() helper */ 62 #define BPF_TAIL_CALL 0xf0 63 64 /* unused opcode to mark call to interpreter with arguments */ 65 #define BPF_CALL_ARGS 0xe0 66 67 /* As per nm, we expose JITed images as text (code) section for 68 * kallsyms. That way, tools like perf can find it to match 69 * addresses. 70 */ 71 #define BPF_SYM_ELF_TYPE 't' 72 73 /* BPF program can access up to 512 bytes of stack space. */ 74 #define MAX_BPF_STACK 512 75 76 /* Helper macros for filter block array initializers. */ 77 78 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 79 80 #define BPF_ALU64_REG(OP, DST, SRC) \ 81 ((struct bpf_insn) { \ 82 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 83 .dst_reg = DST, \ 84 .src_reg = SRC, \ 85 .off = 0, \ 86 .imm = 0 }) 87 88 #define BPF_ALU32_REG(OP, DST, SRC) \ 89 ((struct bpf_insn) { \ 90 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 91 .dst_reg = DST, \ 92 .src_reg = SRC, \ 93 .off = 0, \ 94 .imm = 0 }) 95 96 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 97 98 #define BPF_ALU64_IMM(OP, DST, IMM) \ 99 ((struct bpf_insn) { \ 100 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 101 .dst_reg = DST, \ 102 .src_reg = 0, \ 103 .off = 0, \ 104 .imm = IMM }) 105 106 #define BPF_ALU32_IMM(OP, DST, IMM) \ 107 ((struct bpf_insn) { \ 108 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 109 .dst_reg = DST, \ 110 .src_reg = 0, \ 111 .off = 0, \ 112 .imm = IMM }) 113 114 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 115 116 #define BPF_ENDIAN(TYPE, DST, LEN) \ 117 ((struct bpf_insn) { \ 118 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 119 .dst_reg = DST, \ 120 .src_reg = 0, \ 121 .off = 0, \ 122 .imm = LEN }) 123 124 /* Short form of mov, dst_reg = src_reg */ 125 126 #define BPF_MOV64_REG(DST, SRC) \ 127 ((struct bpf_insn) { \ 128 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 129 .dst_reg = DST, \ 130 .src_reg = SRC, \ 131 .off = 0, \ 132 .imm = 0 }) 133 134 #define BPF_MOV32_REG(DST, SRC) \ 135 ((struct bpf_insn) { \ 136 .code = BPF_ALU | BPF_MOV | BPF_X, \ 137 .dst_reg = DST, \ 138 .src_reg = SRC, \ 139 .off = 0, \ 140 .imm = 0 }) 141 142 /* Short form of mov, dst_reg = imm32 */ 143 144 #define BPF_MOV64_IMM(DST, IMM) \ 145 ((struct bpf_insn) { \ 146 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 147 .dst_reg = DST, \ 148 .src_reg = 0, \ 149 .off = 0, \ 150 .imm = IMM }) 151 152 #define BPF_MOV32_IMM(DST, IMM) \ 153 ((struct bpf_insn) { \ 154 .code = BPF_ALU | BPF_MOV | BPF_K, \ 155 .dst_reg = DST, \ 156 .src_reg = 0, \ 157 .off = 0, \ 158 .imm = IMM }) 159 160 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 161 #define BPF_LD_IMM64(DST, IMM) \ 162 BPF_LD_IMM64_RAW(DST, 0, IMM) 163 164 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 165 ((struct bpf_insn) { \ 166 .code = BPF_LD | BPF_DW | BPF_IMM, \ 167 .dst_reg = DST, \ 168 .src_reg = SRC, \ 169 .off = 0, \ 170 .imm = (__u32) (IMM) }), \ 171 ((struct bpf_insn) { \ 172 .code = 0, /* zero is reserved opcode */ \ 173 .dst_reg = 0, \ 174 .src_reg = 0, \ 175 .off = 0, \ 176 .imm = ((__u64) (IMM)) >> 32 }) 177 178 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 179 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 180 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 181 182 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 183 184 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 185 ((struct bpf_insn) { \ 186 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 187 .dst_reg = DST, \ 188 .src_reg = SRC, \ 189 .off = 0, \ 190 .imm = IMM }) 191 192 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 193 ((struct bpf_insn) { \ 194 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 195 .dst_reg = DST, \ 196 .src_reg = SRC, \ 197 .off = 0, \ 198 .imm = IMM }) 199 200 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 201 202 #define BPF_LD_ABS(SIZE, IMM) \ 203 ((struct bpf_insn) { \ 204 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 205 .dst_reg = 0, \ 206 .src_reg = 0, \ 207 .off = 0, \ 208 .imm = IMM }) 209 210 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 211 212 #define BPF_LD_IND(SIZE, SRC, IMM) \ 213 ((struct bpf_insn) { \ 214 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 215 .dst_reg = 0, \ 216 .src_reg = SRC, \ 217 .off = 0, \ 218 .imm = IMM }) 219 220 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 221 222 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 223 ((struct bpf_insn) { \ 224 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 225 .dst_reg = DST, \ 226 .src_reg = SRC, \ 227 .off = OFF, \ 228 .imm = 0 }) 229 230 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 231 232 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 233 ((struct bpf_insn) { \ 234 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 235 .dst_reg = DST, \ 236 .src_reg = SRC, \ 237 .off = OFF, \ 238 .imm = 0 }) 239 240 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 241 242 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 243 ((struct bpf_insn) { \ 244 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 245 .dst_reg = DST, \ 246 .src_reg = SRC, \ 247 .off = OFF, \ 248 .imm = 0 }) 249 250 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 251 252 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 253 ((struct bpf_insn) { \ 254 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 255 .dst_reg = DST, \ 256 .src_reg = 0, \ 257 .off = OFF, \ 258 .imm = IMM }) 259 260 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 261 262 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 263 ((struct bpf_insn) { \ 264 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 265 .dst_reg = DST, \ 266 .src_reg = SRC, \ 267 .off = OFF, \ 268 .imm = 0 }) 269 270 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 271 272 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 273 ((struct bpf_insn) { \ 274 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 275 .dst_reg = DST, \ 276 .src_reg = 0, \ 277 .off = OFF, \ 278 .imm = IMM }) 279 280 /* Unconditional jumps, goto pc + off16 */ 281 282 #define BPF_JMP_A(OFF) \ 283 ((struct bpf_insn) { \ 284 .code = BPF_JMP | BPF_JA, \ 285 .dst_reg = 0, \ 286 .src_reg = 0, \ 287 .off = OFF, \ 288 .imm = 0 }) 289 290 /* Function call */ 291 292 #define BPF_EMIT_CALL(FUNC) \ 293 ((struct bpf_insn) { \ 294 .code = BPF_JMP | BPF_CALL, \ 295 .dst_reg = 0, \ 296 .src_reg = 0, \ 297 .off = 0, \ 298 .imm = ((FUNC) - __bpf_call_base) }) 299 300 /* Raw code statement block */ 301 302 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 303 ((struct bpf_insn) { \ 304 .code = CODE, \ 305 .dst_reg = DST, \ 306 .src_reg = SRC, \ 307 .off = OFF, \ 308 .imm = IMM }) 309 310 /* Program exit */ 311 312 #define BPF_EXIT_INSN() \ 313 ((struct bpf_insn) { \ 314 .code = BPF_JMP | BPF_EXIT, \ 315 .dst_reg = 0, \ 316 .src_reg = 0, \ 317 .off = 0, \ 318 .imm = 0 }) 319 320 /* Internal classic blocks for direct assignment */ 321 322 #define __BPF_STMT(CODE, K) \ 323 ((struct sock_filter) BPF_STMT(CODE, K)) 324 325 #define __BPF_JUMP(CODE, K, JT, JF) \ 326 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 327 328 #define bytes_to_bpf_size(bytes) \ 329 ({ \ 330 int bpf_size = -EINVAL; \ 331 \ 332 if (bytes == sizeof(u8)) \ 333 bpf_size = BPF_B; \ 334 else if (bytes == sizeof(u16)) \ 335 bpf_size = BPF_H; \ 336 else if (bytes == sizeof(u32)) \ 337 bpf_size = BPF_W; \ 338 else if (bytes == sizeof(u64)) \ 339 bpf_size = BPF_DW; \ 340 \ 341 bpf_size; \ 342 }) 343 344 #define bpf_size_to_bytes(bpf_size) \ 345 ({ \ 346 int bytes = -EINVAL; \ 347 \ 348 if (bpf_size == BPF_B) \ 349 bytes = sizeof(u8); \ 350 else if (bpf_size == BPF_H) \ 351 bytes = sizeof(u16); \ 352 else if (bpf_size == BPF_W) \ 353 bytes = sizeof(u32); \ 354 else if (bpf_size == BPF_DW) \ 355 bytes = sizeof(u64); \ 356 \ 357 bytes; \ 358 }) 359 360 #define BPF_SIZEOF(type) \ 361 ({ \ 362 const int __size = bytes_to_bpf_size(sizeof(type)); \ 363 BUILD_BUG_ON(__size < 0); \ 364 __size; \ 365 }) 366 367 #define BPF_FIELD_SIZEOF(type, field) \ 368 ({ \ 369 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 370 BUILD_BUG_ON(__size < 0); \ 371 __size; \ 372 }) 373 374 #define BPF_LDST_BYTES(insn) \ 375 ({ \ 376 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \ 377 WARN_ON(__size < 0); \ 378 __size; \ 379 }) 380 381 #define __BPF_MAP_0(m, v, ...) v 382 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 383 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 384 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 385 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 386 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 387 388 #define __BPF_REG_0(...) __BPF_PAD(5) 389 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 390 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 391 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 392 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 393 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 394 395 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 396 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 397 398 #define __BPF_CAST(t, a) \ 399 (__force t) \ 400 (__force \ 401 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 402 (unsigned long)0, (t)0))) a 403 #define __BPF_V void 404 #define __BPF_N 405 406 #define __BPF_DECL_ARGS(t, a) t a 407 #define __BPF_DECL_REGS(t, a) u64 a 408 409 #define __BPF_PAD(n) \ 410 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 411 u64, __ur_3, u64, __ur_4, u64, __ur_5) 412 413 #define BPF_CALL_x(x, name, ...) \ 414 static __always_inline \ 415 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 416 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 417 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 418 { \ 419 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 420 } \ 421 static __always_inline \ 422 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 423 424 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 425 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 426 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 427 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 428 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 429 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 430 431 #define bpf_ctx_range(TYPE, MEMBER) \ 432 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 433 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \ 434 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1 435 436 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ 437 ({ \ 438 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \ 439 *(PTR_SIZE) = (SIZE); \ 440 offsetof(TYPE, MEMBER); \ 441 }) 442 443 #ifdef CONFIG_COMPAT 444 /* A struct sock_filter is architecture independent. */ 445 struct compat_sock_fprog { 446 u16 len; 447 compat_uptr_t filter; /* struct sock_filter * */ 448 }; 449 #endif 450 451 struct sock_fprog_kern { 452 u16 len; 453 struct sock_filter *filter; 454 }; 455 456 struct bpf_binary_header { 457 unsigned int pages; 458 u8 image[]; 459 }; 460 461 struct bpf_prog { 462 u16 pages; /* Number of allocated pages */ 463 u16 jited:1, /* Is our filter JIT'ed? */ 464 jit_requested:1,/* archs need to JIT the prog */ 465 locked:1, /* Program image locked? */ 466 gpl_compatible:1, /* Is filter GPL compatible? */ 467 cb_access:1, /* Is control block accessed? */ 468 dst_needed:1, /* Do we need dst entry? */ 469 blinded:1, /* Was blinded */ 470 is_func:1, /* program is a bpf function */ 471 kprobe_override:1; /* Do we override a kprobe? */ 472 enum bpf_prog_type type; /* Type of BPF program */ 473 enum bpf_attach_type expected_attach_type; /* For some prog types */ 474 u32 len; /* Number of filter blocks */ 475 u32 jited_len; /* Size of jited insns in bytes */ 476 u8 tag[BPF_TAG_SIZE]; 477 struct bpf_prog_aux *aux; /* Auxiliary fields */ 478 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 479 unsigned int (*bpf_func)(const void *ctx, 480 const struct bpf_insn *insn); 481 /* Instructions for interpreter */ 482 union { 483 struct sock_filter insns[0]; 484 struct bpf_insn insnsi[0]; 485 }; 486 }; 487 488 struct sk_filter { 489 refcount_t refcnt; 490 struct rcu_head rcu; 491 struct bpf_prog *prog; 492 }; 493 494 #define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi) 495 496 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 497 498 struct bpf_skb_data_end { 499 struct qdisc_skb_cb qdisc_cb; 500 void *data_meta; 501 void *data_end; 502 }; 503 504 struct sk_msg_buff { 505 void *data; 506 void *data_end; 507 __u32 apply_bytes; 508 __u32 cork_bytes; 509 int sg_copybreak; 510 int sg_start; 511 int sg_curr; 512 int sg_end; 513 struct scatterlist sg_data[MAX_SKB_FRAGS]; 514 bool sg_copy[MAX_SKB_FRAGS]; 515 __u32 key; 516 __u32 flags; 517 struct bpf_map *map; 518 struct sk_buff *skb; 519 struct list_head list; 520 }; 521 522 /* Compute the linear packet data range [data, data_end) which 523 * will be accessed by various program types (cls_bpf, act_bpf, 524 * lwt, ...). Subsystems allowing direct data access must (!) 525 * ensure that cb[] area can be written to when BPF program is 526 * invoked (otherwise cb[] save/restore is necessary). 527 */ 528 static inline void bpf_compute_data_pointers(struct sk_buff *skb) 529 { 530 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 531 532 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 533 cb->data_meta = skb->data - skb_metadata_len(skb); 534 cb->data_end = skb->data + skb_headlen(skb); 535 } 536 537 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 538 { 539 /* eBPF programs may read/write skb->cb[] area to transfer meta 540 * data between tail calls. Since this also needs to work with 541 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 542 * 543 * In some socket filter cases, the cb unfortunately needs to be 544 * saved/restored so that protocol specific skb->cb[] data won't 545 * be lost. In any case, due to unpriviledged eBPF programs 546 * attached to sockets, we need to clear the bpf_skb_cb() area 547 * to not leak previous contents to user space. 548 */ 549 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 550 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 551 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 552 553 return qdisc_skb_cb(skb)->data; 554 } 555 556 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 557 struct sk_buff *skb) 558 { 559 u8 *cb_data = bpf_skb_cb(skb); 560 u8 cb_saved[BPF_SKB_CB_LEN]; 561 u32 res; 562 563 if (unlikely(prog->cb_access)) { 564 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 565 memset(cb_data, 0, sizeof(cb_saved)); 566 } 567 568 res = BPF_PROG_RUN(prog, skb); 569 570 if (unlikely(prog->cb_access)) 571 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 572 573 return res; 574 } 575 576 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 577 struct sk_buff *skb) 578 { 579 u8 *cb_data = bpf_skb_cb(skb); 580 581 if (unlikely(prog->cb_access)) 582 memset(cb_data, 0, BPF_SKB_CB_LEN); 583 584 return BPF_PROG_RUN(prog, skb); 585 } 586 587 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 588 struct xdp_buff *xdp) 589 { 590 /* Caller needs to hold rcu_read_lock() (!), otherwise program 591 * can be released while still running, or map elements could be 592 * freed early while still having concurrent users. XDP fastpath 593 * already takes rcu_read_lock() when fetching the program, so 594 * it's not necessary here anymore. 595 */ 596 return BPF_PROG_RUN(prog, xdp); 597 } 598 599 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 600 { 601 return prog->len * sizeof(struct bpf_insn); 602 } 603 604 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 605 { 606 return round_up(bpf_prog_insn_size(prog) + 607 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 608 } 609 610 static inline unsigned int bpf_prog_size(unsigned int proglen) 611 { 612 return max(sizeof(struct bpf_prog), 613 offsetof(struct bpf_prog, insns[proglen])); 614 } 615 616 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 617 { 618 /* When classic BPF programs have been loaded and the arch 619 * does not have a classic BPF JIT (anymore), they have been 620 * converted via bpf_migrate_filter() to eBPF and thus always 621 * have an unspec program type. 622 */ 623 return prog->type == BPF_PROG_TYPE_UNSPEC; 624 } 625 626 static inline bool 627 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default) 628 { 629 bool off_ok; 630 #ifdef __LITTLE_ENDIAN 631 off_ok = (off & (size_default - 1)) == 0; 632 #else 633 off_ok = (off & (size_default - 1)) + size == size_default; 634 #endif 635 return off_ok && size <= size_default && (size & (size - 1)) == 0; 636 } 637 638 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 639 640 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 641 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 642 { 643 fp->locked = 1; 644 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 645 } 646 647 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 648 { 649 if (fp->locked) { 650 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 651 /* In case set_memory_rw() fails, we want to be the first 652 * to crash here instead of some random place later on. 653 */ 654 fp->locked = 0; 655 } 656 } 657 658 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 659 { 660 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 661 } 662 663 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 664 { 665 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 666 } 667 #else 668 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 669 { 670 } 671 672 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 673 { 674 } 675 676 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 677 { 678 } 679 680 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 681 { 682 } 683 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 684 685 static inline struct bpf_binary_header * 686 bpf_jit_binary_hdr(const struct bpf_prog *fp) 687 { 688 unsigned long real_start = (unsigned long)fp->bpf_func; 689 unsigned long addr = real_start & PAGE_MASK; 690 691 return (void *)addr; 692 } 693 694 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 695 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 696 { 697 return sk_filter_trim_cap(sk, skb, 1); 698 } 699 700 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 701 void bpf_prog_free(struct bpf_prog *fp); 702 703 bool bpf_opcode_in_insntable(u8 code); 704 705 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 706 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 707 gfp_t gfp_extra_flags); 708 void __bpf_prog_free(struct bpf_prog *fp); 709 710 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 711 { 712 bpf_prog_unlock_ro(fp); 713 __bpf_prog_free(fp); 714 } 715 716 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 717 unsigned int flen); 718 719 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 720 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 721 bpf_aux_classic_check_t trans, bool save_orig); 722 void bpf_prog_destroy(struct bpf_prog *fp); 723 724 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 725 int sk_attach_bpf(u32 ufd, struct sock *sk); 726 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 727 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 728 int sk_detach_filter(struct sock *sk); 729 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 730 unsigned int len); 731 732 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 733 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 734 735 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 736 #define __bpf_call_base_args \ 737 ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \ 738 __bpf_call_base) 739 740 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 741 void bpf_jit_compile(struct bpf_prog *prog); 742 bool bpf_helper_changes_pkt_data(void *func); 743 744 static inline bool bpf_dump_raw_ok(void) 745 { 746 /* Reconstruction of call-sites is dependent on kallsyms, 747 * thus make dump the same restriction. 748 */ 749 return kallsyms_show_value() == 1; 750 } 751 752 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 753 const struct bpf_insn *patch, u32 len); 754 755 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the 756 * same cpu context. Further for best results no more than a single map 757 * for the do_redirect/do_flush pair should be used. This limitation is 758 * because we only track one map and force a flush when the map changes. 759 * This does not appear to be a real limitation for existing software. 760 */ 761 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, 762 struct bpf_prog *prog); 763 int xdp_do_redirect(struct net_device *dev, 764 struct xdp_buff *xdp, 765 struct bpf_prog *prog); 766 void xdp_do_flush_map(void); 767 768 void bpf_warn_invalid_xdp_action(u32 act); 769 770 struct sock *do_sk_redirect_map(struct sk_buff *skb); 771 struct sock *do_msg_redirect_map(struct sk_msg_buff *md); 772 773 #ifdef CONFIG_BPF_JIT 774 extern int bpf_jit_enable; 775 extern int bpf_jit_harden; 776 extern int bpf_jit_kallsyms; 777 778 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 779 780 struct bpf_binary_header * 781 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 782 unsigned int alignment, 783 bpf_jit_fill_hole_t bpf_fill_ill_insns); 784 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 785 786 void bpf_jit_free(struct bpf_prog *fp); 787 788 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 789 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 790 791 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 792 u32 pass, void *image) 793 { 794 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 795 proglen, pass, image, current->comm, task_pid_nr(current)); 796 797 if (image) 798 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 799 16, 1, image, proglen, false); 800 } 801 802 static inline bool bpf_jit_is_ebpf(void) 803 { 804 # ifdef CONFIG_HAVE_EBPF_JIT 805 return true; 806 # else 807 return false; 808 # endif 809 } 810 811 static inline bool ebpf_jit_enabled(void) 812 { 813 return bpf_jit_enable && bpf_jit_is_ebpf(); 814 } 815 816 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 817 { 818 return fp->jited && bpf_jit_is_ebpf(); 819 } 820 821 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) 822 { 823 /* These are the prerequisites, should someone ever have the 824 * idea to call blinding outside of them, we make sure to 825 * bail out. 826 */ 827 if (!bpf_jit_is_ebpf()) 828 return false; 829 if (!prog->jit_requested) 830 return false; 831 if (!bpf_jit_harden) 832 return false; 833 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 834 return false; 835 836 return true; 837 } 838 839 static inline bool bpf_jit_kallsyms_enabled(void) 840 { 841 /* There are a couple of corner cases where kallsyms should 842 * not be enabled f.e. on hardening. 843 */ 844 if (bpf_jit_harden) 845 return false; 846 if (!bpf_jit_kallsyms) 847 return false; 848 if (bpf_jit_kallsyms == 1) 849 return true; 850 851 return false; 852 } 853 854 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 855 unsigned long *off, char *sym); 856 bool is_bpf_text_address(unsigned long addr); 857 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 858 char *sym); 859 860 static inline const char * 861 bpf_address_lookup(unsigned long addr, unsigned long *size, 862 unsigned long *off, char **modname, char *sym) 863 { 864 const char *ret = __bpf_address_lookup(addr, size, off, sym); 865 866 if (ret && modname) 867 *modname = NULL; 868 return ret; 869 } 870 871 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 872 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 873 874 #else /* CONFIG_BPF_JIT */ 875 876 static inline bool ebpf_jit_enabled(void) 877 { 878 return false; 879 } 880 881 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 882 { 883 return false; 884 } 885 886 static inline void bpf_jit_free(struct bpf_prog *fp) 887 { 888 bpf_prog_unlock_free(fp); 889 } 890 891 static inline bool bpf_jit_kallsyms_enabled(void) 892 { 893 return false; 894 } 895 896 static inline const char * 897 __bpf_address_lookup(unsigned long addr, unsigned long *size, 898 unsigned long *off, char *sym) 899 { 900 return NULL; 901 } 902 903 static inline bool is_bpf_text_address(unsigned long addr) 904 { 905 return false; 906 } 907 908 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 909 char *type, char *sym) 910 { 911 return -ERANGE; 912 } 913 914 static inline const char * 915 bpf_address_lookup(unsigned long addr, unsigned long *size, 916 unsigned long *off, char **modname, char *sym) 917 { 918 return NULL; 919 } 920 921 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 922 { 923 } 924 925 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 926 { 927 } 928 #endif /* CONFIG_BPF_JIT */ 929 930 #define BPF_ANC BIT(15) 931 932 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 933 { 934 switch (first->code) { 935 case BPF_RET | BPF_K: 936 case BPF_LD | BPF_W | BPF_LEN: 937 return false; 938 939 case BPF_LD | BPF_W | BPF_ABS: 940 case BPF_LD | BPF_H | BPF_ABS: 941 case BPF_LD | BPF_B | BPF_ABS: 942 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 943 return true; 944 return false; 945 946 default: 947 return true; 948 } 949 } 950 951 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 952 { 953 BUG_ON(ftest->code & BPF_ANC); 954 955 switch (ftest->code) { 956 case BPF_LD | BPF_W | BPF_ABS: 957 case BPF_LD | BPF_H | BPF_ABS: 958 case BPF_LD | BPF_B | BPF_ABS: 959 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 960 return BPF_ANC | SKF_AD_##CODE 961 switch (ftest->k) { 962 BPF_ANCILLARY(PROTOCOL); 963 BPF_ANCILLARY(PKTTYPE); 964 BPF_ANCILLARY(IFINDEX); 965 BPF_ANCILLARY(NLATTR); 966 BPF_ANCILLARY(NLATTR_NEST); 967 BPF_ANCILLARY(MARK); 968 BPF_ANCILLARY(QUEUE); 969 BPF_ANCILLARY(HATYPE); 970 BPF_ANCILLARY(RXHASH); 971 BPF_ANCILLARY(CPU); 972 BPF_ANCILLARY(ALU_XOR_X); 973 BPF_ANCILLARY(VLAN_TAG); 974 BPF_ANCILLARY(VLAN_TAG_PRESENT); 975 BPF_ANCILLARY(PAY_OFFSET); 976 BPF_ANCILLARY(RANDOM); 977 BPF_ANCILLARY(VLAN_TPID); 978 } 979 /* Fallthrough. */ 980 default: 981 return ftest->code; 982 } 983 } 984 985 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 986 int k, unsigned int size); 987 988 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 989 unsigned int size, void *buffer) 990 { 991 if (k >= 0) 992 return skb_header_pointer(skb, k, size, buffer); 993 994 return bpf_internal_load_pointer_neg_helper(skb, k, size); 995 } 996 997 static inline int bpf_tell_extensions(void) 998 { 999 return SKF_AD_MAX; 1000 } 1001 1002 struct bpf_sock_addr_kern { 1003 struct sock *sk; 1004 struct sockaddr *uaddr; 1005 /* Temporary "register" to make indirect stores to nested structures 1006 * defined above. We need three registers to make such a store, but 1007 * only two (src and dst) are available at convert_ctx_access time 1008 */ 1009 u64 tmp_reg; 1010 }; 1011 1012 struct bpf_sock_ops_kern { 1013 struct sock *sk; 1014 u32 op; 1015 union { 1016 u32 args[4]; 1017 u32 reply; 1018 u32 replylong[4]; 1019 }; 1020 u32 is_fullsock; 1021 u64 temp; /* temp and everything after is not 1022 * initialized to 0 before calling 1023 * the BPF program. New fields that 1024 * should be initialized to 0 should 1025 * be inserted before temp. 1026 * temp is scratch storage used by 1027 * sock_ops_convert_ctx_access 1028 * as temporary storage of a register. 1029 */ 1030 }; 1031 1032 #endif /* __LINUX_FILTER_H__ */ 1033