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 /* As per nm, we expose JITed images as text (code) section for 58 * kallsyms. That way, tools like perf can find it to match 59 * addresses. 60 */ 61 #define BPF_SYM_ELF_TYPE 't' 62 63 /* BPF program can access up to 512 bytes of stack space. */ 64 #define MAX_BPF_STACK 512 65 66 #define BPF_TAG_SIZE 8 67 68 /* Helper macros for filter block array initializers. */ 69 70 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 71 72 #define BPF_ALU64_REG(OP, DST, SRC) \ 73 ((struct bpf_insn) { \ 74 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 75 .dst_reg = DST, \ 76 .src_reg = SRC, \ 77 .off = 0, \ 78 .imm = 0 }) 79 80 #define BPF_ALU32_REG(OP, DST, SRC) \ 81 ((struct bpf_insn) { \ 82 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 83 .dst_reg = DST, \ 84 .src_reg = SRC, \ 85 .off = 0, \ 86 .imm = 0 }) 87 88 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 89 90 #define BPF_ALU64_IMM(OP, DST, IMM) \ 91 ((struct bpf_insn) { \ 92 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 93 .dst_reg = DST, \ 94 .src_reg = 0, \ 95 .off = 0, \ 96 .imm = IMM }) 97 98 #define BPF_ALU32_IMM(OP, DST, IMM) \ 99 ((struct bpf_insn) { \ 100 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 101 .dst_reg = DST, \ 102 .src_reg = 0, \ 103 .off = 0, \ 104 .imm = IMM }) 105 106 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 107 108 #define BPF_ENDIAN(TYPE, DST, LEN) \ 109 ((struct bpf_insn) { \ 110 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 111 .dst_reg = DST, \ 112 .src_reg = 0, \ 113 .off = 0, \ 114 .imm = LEN }) 115 116 /* Short form of mov, dst_reg = src_reg */ 117 118 #define BPF_MOV64_REG(DST, SRC) \ 119 ((struct bpf_insn) { \ 120 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 121 .dst_reg = DST, \ 122 .src_reg = SRC, \ 123 .off = 0, \ 124 .imm = 0 }) 125 126 #define BPF_MOV32_REG(DST, SRC) \ 127 ((struct bpf_insn) { \ 128 .code = BPF_ALU | BPF_MOV | BPF_X, \ 129 .dst_reg = DST, \ 130 .src_reg = SRC, \ 131 .off = 0, \ 132 .imm = 0 }) 133 134 /* Short form of mov, dst_reg = imm32 */ 135 136 #define BPF_MOV64_IMM(DST, IMM) \ 137 ((struct bpf_insn) { \ 138 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 139 .dst_reg = DST, \ 140 .src_reg = 0, \ 141 .off = 0, \ 142 .imm = IMM }) 143 144 #define BPF_MOV32_IMM(DST, IMM) \ 145 ((struct bpf_insn) { \ 146 .code = BPF_ALU | BPF_MOV | BPF_K, \ 147 .dst_reg = DST, \ 148 .src_reg = 0, \ 149 .off = 0, \ 150 .imm = IMM }) 151 152 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 153 #define BPF_LD_IMM64(DST, IMM) \ 154 BPF_LD_IMM64_RAW(DST, 0, IMM) 155 156 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 157 ((struct bpf_insn) { \ 158 .code = BPF_LD | BPF_DW | BPF_IMM, \ 159 .dst_reg = DST, \ 160 .src_reg = SRC, \ 161 .off = 0, \ 162 .imm = (__u32) (IMM) }), \ 163 ((struct bpf_insn) { \ 164 .code = 0, /* zero is reserved opcode */ \ 165 .dst_reg = 0, \ 166 .src_reg = 0, \ 167 .off = 0, \ 168 .imm = ((__u64) (IMM)) >> 32 }) 169 170 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 171 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 172 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 173 174 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 175 176 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 177 ((struct bpf_insn) { \ 178 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 179 .dst_reg = DST, \ 180 .src_reg = SRC, \ 181 .off = 0, \ 182 .imm = IMM }) 183 184 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 185 ((struct bpf_insn) { \ 186 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 187 .dst_reg = DST, \ 188 .src_reg = SRC, \ 189 .off = 0, \ 190 .imm = IMM }) 191 192 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 193 194 #define BPF_LD_ABS(SIZE, IMM) \ 195 ((struct bpf_insn) { \ 196 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 197 .dst_reg = 0, \ 198 .src_reg = 0, \ 199 .off = 0, \ 200 .imm = IMM }) 201 202 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 203 204 #define BPF_LD_IND(SIZE, SRC, IMM) \ 205 ((struct bpf_insn) { \ 206 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 207 .dst_reg = 0, \ 208 .src_reg = SRC, \ 209 .off = 0, \ 210 .imm = IMM }) 211 212 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 213 214 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 215 ((struct bpf_insn) { \ 216 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 217 .dst_reg = DST, \ 218 .src_reg = SRC, \ 219 .off = OFF, \ 220 .imm = 0 }) 221 222 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 223 224 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 225 ((struct bpf_insn) { \ 226 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 227 .dst_reg = DST, \ 228 .src_reg = SRC, \ 229 .off = OFF, \ 230 .imm = 0 }) 231 232 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 233 234 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 235 ((struct bpf_insn) { \ 236 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 237 .dst_reg = DST, \ 238 .src_reg = SRC, \ 239 .off = OFF, \ 240 .imm = 0 }) 241 242 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 243 244 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 245 ((struct bpf_insn) { \ 246 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 247 .dst_reg = DST, \ 248 .src_reg = 0, \ 249 .off = OFF, \ 250 .imm = IMM }) 251 252 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 253 254 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 255 ((struct bpf_insn) { \ 256 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 257 .dst_reg = DST, \ 258 .src_reg = SRC, \ 259 .off = OFF, \ 260 .imm = 0 }) 261 262 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 263 264 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 265 ((struct bpf_insn) { \ 266 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 267 .dst_reg = DST, \ 268 .src_reg = 0, \ 269 .off = OFF, \ 270 .imm = IMM }) 271 272 /* Function call */ 273 274 #define BPF_EMIT_CALL(FUNC) \ 275 ((struct bpf_insn) { \ 276 .code = BPF_JMP | BPF_CALL, \ 277 .dst_reg = 0, \ 278 .src_reg = 0, \ 279 .off = 0, \ 280 .imm = ((FUNC) - __bpf_call_base) }) 281 282 /* Raw code statement block */ 283 284 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 285 ((struct bpf_insn) { \ 286 .code = CODE, \ 287 .dst_reg = DST, \ 288 .src_reg = SRC, \ 289 .off = OFF, \ 290 .imm = IMM }) 291 292 /* Program exit */ 293 294 #define BPF_EXIT_INSN() \ 295 ((struct bpf_insn) { \ 296 .code = BPF_JMP | BPF_EXIT, \ 297 .dst_reg = 0, \ 298 .src_reg = 0, \ 299 .off = 0, \ 300 .imm = 0 }) 301 302 /* Internal classic blocks for direct assignment */ 303 304 #define __BPF_STMT(CODE, K) \ 305 ((struct sock_filter) BPF_STMT(CODE, K)) 306 307 #define __BPF_JUMP(CODE, K, JT, JF) \ 308 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 309 310 #define bytes_to_bpf_size(bytes) \ 311 ({ \ 312 int bpf_size = -EINVAL; \ 313 \ 314 if (bytes == sizeof(u8)) \ 315 bpf_size = BPF_B; \ 316 else if (bytes == sizeof(u16)) \ 317 bpf_size = BPF_H; \ 318 else if (bytes == sizeof(u32)) \ 319 bpf_size = BPF_W; \ 320 else if (bytes == sizeof(u64)) \ 321 bpf_size = BPF_DW; \ 322 \ 323 bpf_size; \ 324 }) 325 326 #define BPF_SIZEOF(type) \ 327 ({ \ 328 const int __size = bytes_to_bpf_size(sizeof(type)); \ 329 BUILD_BUG_ON(__size < 0); \ 330 __size; \ 331 }) 332 333 #define BPF_FIELD_SIZEOF(type, field) \ 334 ({ \ 335 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 336 BUILD_BUG_ON(__size < 0); \ 337 __size; \ 338 }) 339 340 #define __BPF_MAP_0(m, v, ...) v 341 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 342 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 343 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 344 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 345 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 346 347 #define __BPF_REG_0(...) __BPF_PAD(5) 348 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 349 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 350 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 351 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 352 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 353 354 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 355 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 356 357 #define __BPF_CAST(t, a) \ 358 (__force t) \ 359 (__force \ 360 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 361 (unsigned long)0, (t)0))) a 362 #define __BPF_V void 363 #define __BPF_N 364 365 #define __BPF_DECL_ARGS(t, a) t a 366 #define __BPF_DECL_REGS(t, a) u64 a 367 368 #define __BPF_PAD(n) \ 369 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 370 u64, __ur_3, u64, __ur_4, u64, __ur_5) 371 372 #define BPF_CALL_x(x, name, ...) \ 373 static __always_inline \ 374 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 375 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 376 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 377 { \ 378 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 379 } \ 380 static __always_inline \ 381 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 382 383 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 384 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 385 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 386 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 387 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 388 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 389 390 #ifdef CONFIG_COMPAT 391 /* A struct sock_filter is architecture independent. */ 392 struct compat_sock_fprog { 393 u16 len; 394 compat_uptr_t filter; /* struct sock_filter * */ 395 }; 396 #endif 397 398 struct sock_fprog_kern { 399 u16 len; 400 struct sock_filter *filter; 401 }; 402 403 struct bpf_binary_header { 404 unsigned int pages; 405 u8 image[]; 406 }; 407 408 struct bpf_prog { 409 u16 pages; /* Number of allocated pages */ 410 kmemcheck_bitfield_begin(meta); 411 u16 jited:1, /* Is our filter JIT'ed? */ 412 locked:1, /* Program image locked? */ 413 gpl_compatible:1, /* Is filter GPL compatible? */ 414 cb_access:1, /* Is control block accessed? */ 415 dst_needed:1, /* Do we need dst entry? */ 416 xdp_adjust_head:1; /* Adjusting pkt head? */ 417 kmemcheck_bitfield_end(meta); 418 enum bpf_prog_type type; /* Type of BPF program */ 419 u32 len; /* Number of filter blocks */ 420 u8 tag[BPF_TAG_SIZE]; 421 struct bpf_prog_aux *aux; /* Auxiliary fields */ 422 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 423 unsigned int (*bpf_func)(const void *ctx, 424 const struct bpf_insn *insn); 425 /* Instructions for interpreter */ 426 union { 427 struct sock_filter insns[0]; 428 struct bpf_insn insnsi[0]; 429 }; 430 }; 431 432 struct sk_filter { 433 atomic_t refcnt; 434 struct rcu_head rcu; 435 struct bpf_prog *prog; 436 }; 437 438 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 439 440 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 441 442 struct bpf_skb_data_end { 443 struct qdisc_skb_cb qdisc_cb; 444 void *data_end; 445 }; 446 447 struct xdp_buff { 448 void *data; 449 void *data_end; 450 void *data_hard_start; 451 }; 452 453 /* compute the linear packet data range [data, data_end) which 454 * will be accessed by cls_bpf, act_bpf and lwt programs 455 */ 456 static inline void bpf_compute_data_end(struct sk_buff *skb) 457 { 458 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 459 460 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 461 cb->data_end = skb->data + skb_headlen(skb); 462 } 463 464 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 465 { 466 /* eBPF programs may read/write skb->cb[] area to transfer meta 467 * data between tail calls. Since this also needs to work with 468 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 469 * 470 * In some socket filter cases, the cb unfortunately needs to be 471 * saved/restored so that protocol specific skb->cb[] data won't 472 * be lost. In any case, due to unpriviledged eBPF programs 473 * attached to sockets, we need to clear the bpf_skb_cb() area 474 * to not leak previous contents to user space. 475 */ 476 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 477 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 478 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 479 480 return qdisc_skb_cb(skb)->data; 481 } 482 483 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 484 struct sk_buff *skb) 485 { 486 u8 *cb_data = bpf_skb_cb(skb); 487 u8 cb_saved[BPF_SKB_CB_LEN]; 488 u32 res; 489 490 if (unlikely(prog->cb_access)) { 491 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 492 memset(cb_data, 0, sizeof(cb_saved)); 493 } 494 495 res = BPF_PROG_RUN(prog, skb); 496 497 if (unlikely(prog->cb_access)) 498 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 499 500 return res; 501 } 502 503 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 504 struct sk_buff *skb) 505 { 506 u8 *cb_data = bpf_skb_cb(skb); 507 508 if (unlikely(prog->cb_access)) 509 memset(cb_data, 0, BPF_SKB_CB_LEN); 510 511 return BPF_PROG_RUN(prog, skb); 512 } 513 514 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 515 struct xdp_buff *xdp) 516 { 517 /* Caller needs to hold rcu_read_lock() (!), otherwise program 518 * can be released while still running, or map elements could be 519 * freed early while still having concurrent users. XDP fastpath 520 * already takes rcu_read_lock() when fetching the program, so 521 * it's not necessary here anymore. 522 */ 523 return BPF_PROG_RUN(prog, xdp); 524 } 525 526 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 527 { 528 return prog->len * sizeof(struct bpf_insn); 529 } 530 531 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 532 { 533 return round_up(bpf_prog_insn_size(prog) + 534 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 535 } 536 537 static inline unsigned int bpf_prog_size(unsigned int proglen) 538 { 539 return max(sizeof(struct bpf_prog), 540 offsetof(struct bpf_prog, insns[proglen])); 541 } 542 543 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 544 { 545 /* When classic BPF programs have been loaded and the arch 546 * does not have a classic BPF JIT (anymore), they have been 547 * converted via bpf_migrate_filter() to eBPF and thus always 548 * have an unspec program type. 549 */ 550 return prog->type == BPF_PROG_TYPE_UNSPEC; 551 } 552 553 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 554 555 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 556 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 557 { 558 fp->locked = 1; 559 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 560 } 561 562 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 563 { 564 if (fp->locked) { 565 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 566 /* In case set_memory_rw() fails, we want to be the first 567 * to crash here instead of some random place later on. 568 */ 569 fp->locked = 0; 570 } 571 } 572 573 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 574 { 575 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 576 } 577 578 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 579 { 580 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 581 } 582 #else 583 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 584 { 585 } 586 587 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 588 { 589 } 590 591 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 592 { 593 } 594 595 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 596 { 597 } 598 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 599 600 static inline struct bpf_binary_header * 601 bpf_jit_binary_hdr(const struct bpf_prog *fp) 602 { 603 unsigned long real_start = (unsigned long)fp->bpf_func; 604 unsigned long addr = real_start & PAGE_MASK; 605 606 return (void *)addr; 607 } 608 609 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 610 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 611 { 612 return sk_filter_trim_cap(sk, skb, 1); 613 } 614 615 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 616 void bpf_prog_free(struct bpf_prog *fp); 617 618 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 619 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 620 gfp_t gfp_extra_flags); 621 void __bpf_prog_free(struct bpf_prog *fp); 622 623 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 624 { 625 bpf_prog_unlock_ro(fp); 626 __bpf_prog_free(fp); 627 } 628 629 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 630 unsigned int flen); 631 632 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 633 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 634 bpf_aux_classic_check_t trans, bool save_orig); 635 void bpf_prog_destroy(struct bpf_prog *fp); 636 637 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 638 int sk_attach_bpf(u32 ufd, struct sock *sk); 639 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 640 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 641 int sk_detach_filter(struct sock *sk); 642 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 643 unsigned int len); 644 645 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 646 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 647 648 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 649 650 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 651 void bpf_jit_compile(struct bpf_prog *prog); 652 bool bpf_helper_changes_pkt_data(void *func); 653 654 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 655 const struct bpf_insn *patch, u32 len); 656 void bpf_warn_invalid_xdp_action(u32 act); 657 658 #ifdef CONFIG_BPF_JIT 659 extern int bpf_jit_enable; 660 extern int bpf_jit_harden; 661 extern int bpf_jit_kallsyms; 662 663 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 664 665 struct bpf_binary_header * 666 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 667 unsigned int alignment, 668 bpf_jit_fill_hole_t bpf_fill_ill_insns); 669 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 670 671 void bpf_jit_free(struct bpf_prog *fp); 672 673 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 674 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 675 676 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 677 u32 pass, void *image) 678 { 679 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 680 proglen, pass, image, current->comm, task_pid_nr(current)); 681 682 if (image) 683 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 684 16, 1, image, proglen, false); 685 } 686 687 static inline bool bpf_jit_is_ebpf(void) 688 { 689 # ifdef CONFIG_HAVE_EBPF_JIT 690 return true; 691 # else 692 return false; 693 # endif 694 } 695 696 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 697 { 698 return fp->jited && bpf_jit_is_ebpf(); 699 } 700 701 static inline bool bpf_jit_blinding_enabled(void) 702 { 703 /* These are the prerequisites, should someone ever have the 704 * idea to call blinding outside of them, we make sure to 705 * bail out. 706 */ 707 if (!bpf_jit_is_ebpf()) 708 return false; 709 if (!bpf_jit_enable) 710 return false; 711 if (!bpf_jit_harden) 712 return false; 713 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 714 return false; 715 716 return true; 717 } 718 719 static inline bool bpf_jit_kallsyms_enabled(void) 720 { 721 /* There are a couple of corner cases where kallsyms should 722 * not be enabled f.e. on hardening. 723 */ 724 if (bpf_jit_harden) 725 return false; 726 if (!bpf_jit_kallsyms) 727 return false; 728 if (bpf_jit_kallsyms == 1) 729 return true; 730 731 return false; 732 } 733 734 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 735 unsigned long *off, char *sym); 736 bool is_bpf_text_address(unsigned long addr); 737 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 738 char *sym); 739 740 static inline const char * 741 bpf_address_lookup(unsigned long addr, unsigned long *size, 742 unsigned long *off, char **modname, char *sym) 743 { 744 const char *ret = __bpf_address_lookup(addr, size, off, sym); 745 746 if (ret && modname) 747 *modname = NULL; 748 return ret; 749 } 750 751 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 752 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 753 754 #else /* CONFIG_BPF_JIT */ 755 756 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 757 { 758 return false; 759 } 760 761 static inline void bpf_jit_free(struct bpf_prog *fp) 762 { 763 bpf_prog_unlock_free(fp); 764 } 765 766 static inline bool bpf_jit_kallsyms_enabled(void) 767 { 768 return false; 769 } 770 771 static inline const char * 772 __bpf_address_lookup(unsigned long addr, unsigned long *size, 773 unsigned long *off, char *sym) 774 { 775 return NULL; 776 } 777 778 static inline bool is_bpf_text_address(unsigned long addr) 779 { 780 return false; 781 } 782 783 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 784 char *type, char *sym) 785 { 786 return -ERANGE; 787 } 788 789 static inline const char * 790 bpf_address_lookup(unsigned long addr, unsigned long *size, 791 unsigned long *off, char **modname, char *sym) 792 { 793 return NULL; 794 } 795 796 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 797 { 798 } 799 800 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 801 { 802 } 803 #endif /* CONFIG_BPF_JIT */ 804 805 #define BPF_ANC BIT(15) 806 807 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 808 { 809 switch (first->code) { 810 case BPF_RET | BPF_K: 811 case BPF_LD | BPF_W | BPF_LEN: 812 return false; 813 814 case BPF_LD | BPF_W | BPF_ABS: 815 case BPF_LD | BPF_H | BPF_ABS: 816 case BPF_LD | BPF_B | BPF_ABS: 817 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 818 return true; 819 return false; 820 821 default: 822 return true; 823 } 824 } 825 826 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 827 { 828 BUG_ON(ftest->code & BPF_ANC); 829 830 switch (ftest->code) { 831 case BPF_LD | BPF_W | BPF_ABS: 832 case BPF_LD | BPF_H | BPF_ABS: 833 case BPF_LD | BPF_B | BPF_ABS: 834 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 835 return BPF_ANC | SKF_AD_##CODE 836 switch (ftest->k) { 837 BPF_ANCILLARY(PROTOCOL); 838 BPF_ANCILLARY(PKTTYPE); 839 BPF_ANCILLARY(IFINDEX); 840 BPF_ANCILLARY(NLATTR); 841 BPF_ANCILLARY(NLATTR_NEST); 842 BPF_ANCILLARY(MARK); 843 BPF_ANCILLARY(QUEUE); 844 BPF_ANCILLARY(HATYPE); 845 BPF_ANCILLARY(RXHASH); 846 BPF_ANCILLARY(CPU); 847 BPF_ANCILLARY(ALU_XOR_X); 848 BPF_ANCILLARY(VLAN_TAG); 849 BPF_ANCILLARY(VLAN_TAG_PRESENT); 850 BPF_ANCILLARY(PAY_OFFSET); 851 BPF_ANCILLARY(RANDOM); 852 BPF_ANCILLARY(VLAN_TPID); 853 } 854 /* Fallthrough. */ 855 default: 856 return ftest->code; 857 } 858 } 859 860 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 861 int k, unsigned int size); 862 863 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 864 unsigned int size, void *buffer) 865 { 866 if (k >= 0) 867 return skb_header_pointer(skb, k, size, buffer); 868 869 return bpf_internal_load_pointer_neg_helper(skb, k, size); 870 } 871 872 static inline int bpf_tell_extensions(void) 873 { 874 return SKF_AD_MAX; 875 } 876 877 #endif /* __LINUX_FILTER_H__ */ 878