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 20 #include <net/sch_generic.h> 21 22 #include <asm/cacheflush.h> 23 24 #include <uapi/linux/filter.h> 25 #include <uapi/linux/bpf.h> 26 27 struct sk_buff; 28 struct sock; 29 struct seccomp_data; 30 struct bpf_prog_aux; 31 32 /* ArgX, context and stack frame pointer register positions. Note, 33 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 34 * calls in BPF_CALL instruction. 35 */ 36 #define BPF_REG_ARG1 BPF_REG_1 37 #define BPF_REG_ARG2 BPF_REG_2 38 #define BPF_REG_ARG3 BPF_REG_3 39 #define BPF_REG_ARG4 BPF_REG_4 40 #define BPF_REG_ARG5 BPF_REG_5 41 #define BPF_REG_CTX BPF_REG_6 42 #define BPF_REG_FP BPF_REG_10 43 44 /* Additional register mappings for converted user programs. */ 45 #define BPF_REG_A BPF_REG_0 46 #define BPF_REG_X BPF_REG_7 47 #define BPF_REG_TMP BPF_REG_8 48 49 /* Kernel hidden auxiliary/helper register for hardening step. 50 * Only used by eBPF JITs. It's nothing more than a temporary 51 * register that JITs use internally, only that here it's part 52 * of eBPF instructions that have been rewritten for blinding 53 * constants. See JIT pre-step in bpf_jit_blind_constants(). 54 */ 55 #define BPF_REG_AX MAX_BPF_REG 56 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 57 58 /* As per nm, we expose JITed images as text (code) section for 59 * kallsyms. That way, tools like perf can find it to match 60 * addresses. 61 */ 62 #define BPF_SYM_ELF_TYPE 't' 63 64 /* BPF program can access up to 512 bytes of stack space. */ 65 #define MAX_BPF_STACK 512 66 67 #define BPF_TAG_SIZE 8 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 /* Function call */ 274 275 #define BPF_EMIT_CALL(FUNC) \ 276 ((struct bpf_insn) { \ 277 .code = BPF_JMP | BPF_CALL, \ 278 .dst_reg = 0, \ 279 .src_reg = 0, \ 280 .off = 0, \ 281 .imm = ((FUNC) - __bpf_call_base) }) 282 283 /* Raw code statement block */ 284 285 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 286 ((struct bpf_insn) { \ 287 .code = CODE, \ 288 .dst_reg = DST, \ 289 .src_reg = SRC, \ 290 .off = OFF, \ 291 .imm = IMM }) 292 293 /* Program exit */ 294 295 #define BPF_EXIT_INSN() \ 296 ((struct bpf_insn) { \ 297 .code = BPF_JMP | BPF_EXIT, \ 298 .dst_reg = 0, \ 299 .src_reg = 0, \ 300 .off = 0, \ 301 .imm = 0 }) 302 303 /* Internal classic blocks for direct assignment */ 304 305 #define __BPF_STMT(CODE, K) \ 306 ((struct sock_filter) BPF_STMT(CODE, K)) 307 308 #define __BPF_JUMP(CODE, K, JT, JF) \ 309 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 310 311 #define bytes_to_bpf_size(bytes) \ 312 ({ \ 313 int bpf_size = -EINVAL; \ 314 \ 315 if (bytes == sizeof(u8)) \ 316 bpf_size = BPF_B; \ 317 else if (bytes == sizeof(u16)) \ 318 bpf_size = BPF_H; \ 319 else if (bytes == sizeof(u32)) \ 320 bpf_size = BPF_W; \ 321 else if (bytes == sizeof(u64)) \ 322 bpf_size = BPF_DW; \ 323 \ 324 bpf_size; \ 325 }) 326 327 #define BPF_SIZEOF(type) \ 328 ({ \ 329 const int __size = bytes_to_bpf_size(sizeof(type)); \ 330 BUILD_BUG_ON(__size < 0); \ 331 __size; \ 332 }) 333 334 #define BPF_FIELD_SIZEOF(type, field) \ 335 ({ \ 336 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 337 BUILD_BUG_ON(__size < 0); \ 338 __size; \ 339 }) 340 341 #define __BPF_MAP_0(m, v, ...) v 342 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 343 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 344 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 345 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 346 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 347 348 #define __BPF_REG_0(...) __BPF_PAD(5) 349 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 350 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 351 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 352 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 353 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 354 355 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 356 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 357 358 #define __BPF_CAST(t, a) \ 359 (__force t) \ 360 (__force \ 361 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 362 (unsigned long)0, (t)0))) a 363 #define __BPF_V void 364 #define __BPF_N 365 366 #define __BPF_DECL_ARGS(t, a) t a 367 #define __BPF_DECL_REGS(t, a) u64 a 368 369 #define __BPF_PAD(n) \ 370 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 371 u64, __ur_3, u64, __ur_4, u64, __ur_5) 372 373 #define BPF_CALL_x(x, name, ...) \ 374 static __always_inline \ 375 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 376 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 377 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 378 { \ 379 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 380 } \ 381 static __always_inline \ 382 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 383 384 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 385 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 386 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 387 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 388 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 389 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 390 391 #ifdef CONFIG_COMPAT 392 /* A struct sock_filter is architecture independent. */ 393 struct compat_sock_fprog { 394 u16 len; 395 compat_uptr_t filter; /* struct sock_filter * */ 396 }; 397 #endif 398 399 struct sock_fprog_kern { 400 u16 len; 401 struct sock_filter *filter; 402 }; 403 404 struct bpf_binary_header { 405 unsigned int pages; 406 u8 image[]; 407 }; 408 409 struct bpf_prog { 410 u16 pages; /* Number of allocated pages */ 411 kmemcheck_bitfield_begin(meta); 412 u16 jited:1, /* Is our filter JIT'ed? */ 413 locked:1, /* Program image locked? */ 414 gpl_compatible:1, /* Is filter GPL compatible? */ 415 cb_access:1, /* Is control block accessed? */ 416 dst_needed:1; /* Do we need dst entry? */ 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 refcount_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 ebpf_jit_enabled(void) 697 { 698 return bpf_jit_enable && bpf_jit_is_ebpf(); 699 } 700 701 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 702 { 703 return fp->jited && bpf_jit_is_ebpf(); 704 } 705 706 static inline bool bpf_jit_blinding_enabled(void) 707 { 708 /* These are the prerequisites, should someone ever have the 709 * idea to call blinding outside of them, we make sure to 710 * bail out. 711 */ 712 if (!bpf_jit_is_ebpf()) 713 return false; 714 if (!bpf_jit_enable) 715 return false; 716 if (!bpf_jit_harden) 717 return false; 718 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 719 return false; 720 721 return true; 722 } 723 724 static inline bool bpf_jit_kallsyms_enabled(void) 725 { 726 /* There are a couple of corner cases where kallsyms should 727 * not be enabled f.e. on hardening. 728 */ 729 if (bpf_jit_harden) 730 return false; 731 if (!bpf_jit_kallsyms) 732 return false; 733 if (bpf_jit_kallsyms == 1) 734 return true; 735 736 return false; 737 } 738 739 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 740 unsigned long *off, char *sym); 741 bool is_bpf_text_address(unsigned long addr); 742 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 743 char *sym); 744 745 static inline const char * 746 bpf_address_lookup(unsigned long addr, unsigned long *size, 747 unsigned long *off, char **modname, char *sym) 748 { 749 const char *ret = __bpf_address_lookup(addr, size, off, sym); 750 751 if (ret && modname) 752 *modname = NULL; 753 return ret; 754 } 755 756 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 757 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 758 759 #else /* CONFIG_BPF_JIT */ 760 761 static inline bool ebpf_jit_enabled(void) 762 { 763 return false; 764 } 765 766 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 767 { 768 return false; 769 } 770 771 static inline void bpf_jit_free(struct bpf_prog *fp) 772 { 773 bpf_prog_unlock_free(fp); 774 } 775 776 static inline bool bpf_jit_kallsyms_enabled(void) 777 { 778 return false; 779 } 780 781 static inline const char * 782 __bpf_address_lookup(unsigned long addr, unsigned long *size, 783 unsigned long *off, char *sym) 784 { 785 return NULL; 786 } 787 788 static inline bool is_bpf_text_address(unsigned long addr) 789 { 790 return false; 791 } 792 793 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 794 char *type, char *sym) 795 { 796 return -ERANGE; 797 } 798 799 static inline const char * 800 bpf_address_lookup(unsigned long addr, unsigned long *size, 801 unsigned long *off, char **modname, char *sym) 802 { 803 return NULL; 804 } 805 806 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 807 { 808 } 809 810 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 811 { 812 } 813 #endif /* CONFIG_BPF_JIT */ 814 815 #define BPF_ANC BIT(15) 816 817 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 818 { 819 switch (first->code) { 820 case BPF_RET | BPF_K: 821 case BPF_LD | BPF_W | BPF_LEN: 822 return false; 823 824 case BPF_LD | BPF_W | BPF_ABS: 825 case BPF_LD | BPF_H | BPF_ABS: 826 case BPF_LD | BPF_B | BPF_ABS: 827 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 828 return true; 829 return false; 830 831 default: 832 return true; 833 } 834 } 835 836 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 837 { 838 BUG_ON(ftest->code & BPF_ANC); 839 840 switch (ftest->code) { 841 case BPF_LD | BPF_W | BPF_ABS: 842 case BPF_LD | BPF_H | BPF_ABS: 843 case BPF_LD | BPF_B | BPF_ABS: 844 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 845 return BPF_ANC | SKF_AD_##CODE 846 switch (ftest->k) { 847 BPF_ANCILLARY(PROTOCOL); 848 BPF_ANCILLARY(PKTTYPE); 849 BPF_ANCILLARY(IFINDEX); 850 BPF_ANCILLARY(NLATTR); 851 BPF_ANCILLARY(NLATTR_NEST); 852 BPF_ANCILLARY(MARK); 853 BPF_ANCILLARY(QUEUE); 854 BPF_ANCILLARY(HATYPE); 855 BPF_ANCILLARY(RXHASH); 856 BPF_ANCILLARY(CPU); 857 BPF_ANCILLARY(ALU_XOR_X); 858 BPF_ANCILLARY(VLAN_TAG); 859 BPF_ANCILLARY(VLAN_TAG_PRESENT); 860 BPF_ANCILLARY(PAY_OFFSET); 861 BPF_ANCILLARY(RANDOM); 862 BPF_ANCILLARY(VLAN_TPID); 863 } 864 /* Fallthrough. */ 865 default: 866 return ftest->code; 867 } 868 } 869 870 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 871 int k, unsigned int size); 872 873 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 874 unsigned int size, void *buffer) 875 { 876 if (k >= 0) 877 return skb_header_pointer(skb, k, size, buffer); 878 879 return bpf_internal_load_pointer_neg_helper(skb, k, size); 880 } 881 882 static inline int bpf_tell_extensions(void) 883 { 884 return SKF_AD_MAX; 885 } 886 887 #endif /* __LINUX_FILTER_H__ */ 888