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 gpl_compatible:1, /* Is filter GPL compatible? */ 413 cb_access:1, /* Is control block accessed? */ 414 dst_needed:1, /* Do we need dst entry? */ 415 xdp_adjust_head:1; /* Adjusting pkt head? */ 416 kmemcheck_bitfield_end(meta); 417 enum bpf_prog_type type; /* Type of BPF program */ 418 u32 len; /* Number of filter blocks */ 419 u8 tag[BPF_TAG_SIZE]; 420 struct bpf_prog_aux *aux; /* Auxiliary fields */ 421 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 422 unsigned int (*bpf_func)(const void *ctx, 423 const struct bpf_insn *insn); 424 /* Instructions for interpreter */ 425 union { 426 struct sock_filter insns[0]; 427 struct bpf_insn insnsi[0]; 428 }; 429 }; 430 431 struct sk_filter { 432 atomic_t refcnt; 433 struct rcu_head rcu; 434 struct bpf_prog *prog; 435 }; 436 437 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 438 439 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 440 441 struct bpf_skb_data_end { 442 struct qdisc_skb_cb qdisc_cb; 443 void *data_end; 444 }; 445 446 struct xdp_buff { 447 void *data; 448 void *data_end; 449 void *data_hard_start; 450 }; 451 452 /* compute the linear packet data range [data, data_end) which 453 * will be accessed by cls_bpf, act_bpf and lwt programs 454 */ 455 static inline void bpf_compute_data_end(struct sk_buff *skb) 456 { 457 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 458 459 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 460 cb->data_end = skb->data + skb_headlen(skb); 461 } 462 463 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 464 { 465 /* eBPF programs may read/write skb->cb[] area to transfer meta 466 * data between tail calls. Since this also needs to work with 467 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 468 * 469 * In some socket filter cases, the cb unfortunately needs to be 470 * saved/restored so that protocol specific skb->cb[] data won't 471 * be lost. In any case, due to unpriviledged eBPF programs 472 * attached to sockets, we need to clear the bpf_skb_cb() area 473 * to not leak previous contents to user space. 474 */ 475 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 476 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 477 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 478 479 return qdisc_skb_cb(skb)->data; 480 } 481 482 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 483 struct sk_buff *skb) 484 { 485 u8 *cb_data = bpf_skb_cb(skb); 486 u8 cb_saved[BPF_SKB_CB_LEN]; 487 u32 res; 488 489 if (unlikely(prog->cb_access)) { 490 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 491 memset(cb_data, 0, sizeof(cb_saved)); 492 } 493 494 res = BPF_PROG_RUN(prog, skb); 495 496 if (unlikely(prog->cb_access)) 497 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 498 499 return res; 500 } 501 502 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 503 struct sk_buff *skb) 504 { 505 u8 *cb_data = bpf_skb_cb(skb); 506 507 if (unlikely(prog->cb_access)) 508 memset(cb_data, 0, BPF_SKB_CB_LEN); 509 510 return BPF_PROG_RUN(prog, skb); 511 } 512 513 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 514 struct xdp_buff *xdp) 515 { 516 /* Caller needs to hold rcu_read_lock() (!), otherwise program 517 * can be released while still running, or map elements could be 518 * freed early while still having concurrent users. XDP fastpath 519 * already takes rcu_read_lock() when fetching the program, so 520 * it's not necessary here anymore. 521 */ 522 return BPF_PROG_RUN(prog, xdp); 523 } 524 525 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 526 { 527 return prog->len * sizeof(struct bpf_insn); 528 } 529 530 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 531 { 532 return round_up(bpf_prog_insn_size(prog) + 533 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 534 } 535 536 static inline unsigned int bpf_prog_size(unsigned int proglen) 537 { 538 return max(sizeof(struct bpf_prog), 539 offsetof(struct bpf_prog, insns[proglen])); 540 } 541 542 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 543 { 544 /* When classic BPF programs have been loaded and the arch 545 * does not have a classic BPF JIT (anymore), they have been 546 * converted via bpf_migrate_filter() to eBPF and thus always 547 * have an unspec program type. 548 */ 549 return prog->type == BPF_PROG_TYPE_UNSPEC; 550 } 551 552 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 553 554 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 555 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 556 { 557 set_memory_ro((unsigned long)fp, fp->pages); 558 } 559 560 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 561 { 562 set_memory_rw((unsigned long)fp, fp->pages); 563 } 564 565 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 566 { 567 set_memory_ro((unsigned long)hdr, hdr->pages); 568 } 569 570 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 571 { 572 set_memory_rw((unsigned long)hdr, hdr->pages); 573 } 574 #else 575 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 576 { 577 } 578 579 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 580 { 581 } 582 583 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 584 { 585 } 586 587 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 588 { 589 } 590 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 591 592 static inline struct bpf_binary_header * 593 bpf_jit_binary_hdr(const struct bpf_prog *fp) 594 { 595 unsigned long real_start = (unsigned long)fp->bpf_func; 596 unsigned long addr = real_start & PAGE_MASK; 597 598 return (void *)addr; 599 } 600 601 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 602 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 603 { 604 return sk_filter_trim_cap(sk, skb, 1); 605 } 606 607 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 608 void bpf_prog_free(struct bpf_prog *fp); 609 610 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 611 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 612 gfp_t gfp_extra_flags); 613 void __bpf_prog_free(struct bpf_prog *fp); 614 615 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 616 { 617 bpf_prog_unlock_ro(fp); 618 __bpf_prog_free(fp); 619 } 620 621 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 622 unsigned int flen); 623 624 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 625 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 626 bpf_aux_classic_check_t trans, bool save_orig); 627 void bpf_prog_destroy(struct bpf_prog *fp); 628 629 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 630 int sk_attach_bpf(u32 ufd, struct sock *sk); 631 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 632 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 633 int sk_detach_filter(struct sock *sk); 634 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 635 unsigned int len); 636 637 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 638 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 639 640 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 641 642 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 643 void bpf_jit_compile(struct bpf_prog *prog); 644 bool bpf_helper_changes_pkt_data(void *func); 645 646 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 647 const struct bpf_insn *patch, u32 len); 648 void bpf_warn_invalid_xdp_action(u32 act); 649 650 #ifdef CONFIG_BPF_JIT 651 extern int bpf_jit_enable; 652 extern int bpf_jit_harden; 653 extern int bpf_jit_kallsyms; 654 655 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 656 657 struct bpf_binary_header * 658 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 659 unsigned int alignment, 660 bpf_jit_fill_hole_t bpf_fill_ill_insns); 661 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 662 663 void bpf_jit_free(struct bpf_prog *fp); 664 665 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 666 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 667 668 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 669 u32 pass, void *image) 670 { 671 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 672 proglen, pass, image, current->comm, task_pid_nr(current)); 673 674 if (image) 675 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 676 16, 1, image, proglen, false); 677 } 678 679 static inline bool bpf_jit_is_ebpf(void) 680 { 681 # ifdef CONFIG_HAVE_EBPF_JIT 682 return true; 683 # else 684 return false; 685 # endif 686 } 687 688 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 689 { 690 return fp->jited && bpf_jit_is_ebpf(); 691 } 692 693 static inline bool bpf_jit_blinding_enabled(void) 694 { 695 /* These are the prerequisites, should someone ever have the 696 * idea to call blinding outside of them, we make sure to 697 * bail out. 698 */ 699 if (!bpf_jit_is_ebpf()) 700 return false; 701 if (!bpf_jit_enable) 702 return false; 703 if (!bpf_jit_harden) 704 return false; 705 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 706 return false; 707 708 return true; 709 } 710 711 static inline bool bpf_jit_kallsyms_enabled(void) 712 { 713 /* There are a couple of corner cases where kallsyms should 714 * not be enabled f.e. on hardening. 715 */ 716 if (bpf_jit_harden) 717 return false; 718 if (!bpf_jit_kallsyms) 719 return false; 720 if (bpf_jit_kallsyms == 1) 721 return true; 722 723 return false; 724 } 725 726 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 727 unsigned long *off, char *sym); 728 bool is_bpf_text_address(unsigned long addr); 729 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 730 char *sym); 731 732 static inline const char * 733 bpf_address_lookup(unsigned long addr, unsigned long *size, 734 unsigned long *off, char **modname, char *sym) 735 { 736 const char *ret = __bpf_address_lookup(addr, size, off, sym); 737 738 if (ret && modname) 739 *modname = NULL; 740 return ret; 741 } 742 743 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 744 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 745 746 #else /* CONFIG_BPF_JIT */ 747 748 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 749 { 750 return false; 751 } 752 753 static inline void bpf_jit_free(struct bpf_prog *fp) 754 { 755 bpf_prog_unlock_free(fp); 756 } 757 758 static inline bool bpf_jit_kallsyms_enabled(void) 759 { 760 return false; 761 } 762 763 static inline const char * 764 __bpf_address_lookup(unsigned long addr, unsigned long *size, 765 unsigned long *off, char *sym) 766 { 767 return NULL; 768 } 769 770 static inline bool is_bpf_text_address(unsigned long addr) 771 { 772 return false; 773 } 774 775 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 776 char *type, char *sym) 777 { 778 return -ERANGE; 779 } 780 781 static inline const char * 782 bpf_address_lookup(unsigned long addr, unsigned long *size, 783 unsigned long *off, char **modname, char *sym) 784 { 785 return NULL; 786 } 787 788 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 789 { 790 } 791 792 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 793 { 794 } 795 #endif /* CONFIG_BPF_JIT */ 796 797 #define BPF_ANC BIT(15) 798 799 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 800 { 801 switch (first->code) { 802 case BPF_RET | BPF_K: 803 case BPF_LD | BPF_W | BPF_LEN: 804 return false; 805 806 case BPF_LD | BPF_W | BPF_ABS: 807 case BPF_LD | BPF_H | BPF_ABS: 808 case BPF_LD | BPF_B | BPF_ABS: 809 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 810 return true; 811 return false; 812 813 default: 814 return true; 815 } 816 } 817 818 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 819 { 820 BUG_ON(ftest->code & BPF_ANC); 821 822 switch (ftest->code) { 823 case BPF_LD | BPF_W | BPF_ABS: 824 case BPF_LD | BPF_H | BPF_ABS: 825 case BPF_LD | BPF_B | BPF_ABS: 826 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 827 return BPF_ANC | SKF_AD_##CODE 828 switch (ftest->k) { 829 BPF_ANCILLARY(PROTOCOL); 830 BPF_ANCILLARY(PKTTYPE); 831 BPF_ANCILLARY(IFINDEX); 832 BPF_ANCILLARY(NLATTR); 833 BPF_ANCILLARY(NLATTR_NEST); 834 BPF_ANCILLARY(MARK); 835 BPF_ANCILLARY(QUEUE); 836 BPF_ANCILLARY(HATYPE); 837 BPF_ANCILLARY(RXHASH); 838 BPF_ANCILLARY(CPU); 839 BPF_ANCILLARY(ALU_XOR_X); 840 BPF_ANCILLARY(VLAN_TAG); 841 BPF_ANCILLARY(VLAN_TAG_PRESENT); 842 BPF_ANCILLARY(PAY_OFFSET); 843 BPF_ANCILLARY(RANDOM); 844 BPF_ANCILLARY(VLAN_TPID); 845 } 846 /* Fallthrough. */ 847 default: 848 return ftest->code; 849 } 850 } 851 852 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 853 int k, unsigned int size); 854 855 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 856 unsigned int size, void *buffer) 857 { 858 if (k >= 0) 859 return skb_header_pointer(skb, k, size, buffer); 860 861 return bpf_internal_load_pointer_neg_helper(skb, k, size); 862 } 863 864 static inline int bpf_tell_extensions(void) 865 { 866 return SKF_AD_MAX; 867 } 868 869 #endif /* __LINUX_FILTER_H__ */ 870