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