1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Linux Socket Filter Data Structures 4 */ 5 #ifndef __LINUX_FILTER_H__ 6 #define __LINUX_FILTER_H__ 7 8 #include <stdarg.h> 9 10 #include <linux/atomic.h> 11 #include <linux/refcount.h> 12 #include <linux/compat.h> 13 #include <linux/skbuff.h> 14 #include <linux/linkage.h> 15 #include <linux/printk.h> 16 #include <linux/workqueue.h> 17 #include <linux/sched.h> 18 #include <linux/capability.h> 19 #include <linux/cryptohash.h> 20 #include <linux/set_memory.h> 21 #include <linux/kallsyms.h> 22 23 #include <net/sch_generic.h> 24 25 #include <uapi/linux/filter.h> 26 #include <uapi/linux/bpf.h> 27 28 struct sk_buff; 29 struct sock; 30 struct seccomp_data; 31 struct bpf_prog_aux; 32 struct xdp_rxq_info; 33 struct xdp_buff; 34 35 /* ArgX, context and stack frame pointer register positions. Note, 36 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 37 * calls in BPF_CALL instruction. 38 */ 39 #define BPF_REG_ARG1 BPF_REG_1 40 #define BPF_REG_ARG2 BPF_REG_2 41 #define BPF_REG_ARG3 BPF_REG_3 42 #define BPF_REG_ARG4 BPF_REG_4 43 #define BPF_REG_ARG5 BPF_REG_5 44 #define BPF_REG_CTX BPF_REG_6 45 #define BPF_REG_FP BPF_REG_10 46 47 /* Additional register mappings for converted user programs. */ 48 #define BPF_REG_A BPF_REG_0 49 #define BPF_REG_X BPF_REG_7 50 #define BPF_REG_TMP BPF_REG_2 /* scratch reg */ 51 #define BPF_REG_D BPF_REG_8 /* data, callee-saved */ 52 #define BPF_REG_H BPF_REG_9 /* hlen, callee-saved */ 53 54 /* Kernel hidden auxiliary/helper register for hardening step. 55 * Only used by eBPF JITs. It's nothing more than a temporary 56 * register that JITs use internally, only that here it's part 57 * of eBPF instructions that have been rewritten for blinding 58 * constants. See JIT pre-step in bpf_jit_blind_constants(). 59 */ 60 #define BPF_REG_AX MAX_BPF_REG 61 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) 62 63 /* unused opcode to mark special call to bpf_tail_call() helper */ 64 #define BPF_TAIL_CALL 0xf0 65 66 /* unused opcode to mark call to interpreter with arguments */ 67 #define BPF_CALL_ARGS 0xe0 68 69 /* As per nm, we expose JITed images as text (code) section for 70 * kallsyms. That way, tools like perf can find it to match 71 * addresses. 72 */ 73 #define BPF_SYM_ELF_TYPE 't' 74 75 /* BPF program can access up to 512 bytes of stack space. */ 76 #define MAX_BPF_STACK 512 77 78 /* Helper macros for filter block array initializers. */ 79 80 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 81 82 #define BPF_ALU64_REG(OP, DST, SRC) \ 83 ((struct bpf_insn) { \ 84 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 85 .dst_reg = DST, \ 86 .src_reg = SRC, \ 87 .off = 0, \ 88 .imm = 0 }) 89 90 #define BPF_ALU32_REG(OP, DST, SRC) \ 91 ((struct bpf_insn) { \ 92 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 93 .dst_reg = DST, \ 94 .src_reg = SRC, \ 95 .off = 0, \ 96 .imm = 0 }) 97 98 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 99 100 #define BPF_ALU64_IMM(OP, DST, IMM) \ 101 ((struct bpf_insn) { \ 102 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 103 .dst_reg = DST, \ 104 .src_reg = 0, \ 105 .off = 0, \ 106 .imm = IMM }) 107 108 #define BPF_ALU32_IMM(OP, DST, IMM) \ 109 ((struct bpf_insn) { \ 110 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 111 .dst_reg = DST, \ 112 .src_reg = 0, \ 113 .off = 0, \ 114 .imm = IMM }) 115 116 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 117 118 #define BPF_ENDIAN(TYPE, DST, LEN) \ 119 ((struct bpf_insn) { \ 120 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 121 .dst_reg = DST, \ 122 .src_reg = 0, \ 123 .off = 0, \ 124 .imm = LEN }) 125 126 /* Short form of mov, dst_reg = src_reg */ 127 128 #define BPF_MOV64_REG(DST, SRC) \ 129 ((struct bpf_insn) { \ 130 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 131 .dst_reg = DST, \ 132 .src_reg = SRC, \ 133 .off = 0, \ 134 .imm = 0 }) 135 136 #define BPF_MOV32_REG(DST, SRC) \ 137 ((struct bpf_insn) { \ 138 .code = BPF_ALU | BPF_MOV | BPF_X, \ 139 .dst_reg = DST, \ 140 .src_reg = SRC, \ 141 .off = 0, \ 142 .imm = 0 }) 143 144 /* Short form of mov, dst_reg = imm32 */ 145 146 #define BPF_MOV64_IMM(DST, IMM) \ 147 ((struct bpf_insn) { \ 148 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 149 .dst_reg = DST, \ 150 .src_reg = 0, \ 151 .off = 0, \ 152 .imm = IMM }) 153 154 #define BPF_MOV32_IMM(DST, IMM) \ 155 ((struct bpf_insn) { \ 156 .code = BPF_ALU | BPF_MOV | BPF_K, \ 157 .dst_reg = DST, \ 158 .src_reg = 0, \ 159 .off = 0, \ 160 .imm = IMM }) 161 162 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 163 #define BPF_LD_IMM64(DST, IMM) \ 164 BPF_LD_IMM64_RAW(DST, 0, IMM) 165 166 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 167 ((struct bpf_insn) { \ 168 .code = BPF_LD | BPF_DW | BPF_IMM, \ 169 .dst_reg = DST, \ 170 .src_reg = SRC, \ 171 .off = 0, \ 172 .imm = (__u32) (IMM) }), \ 173 ((struct bpf_insn) { \ 174 .code = 0, /* zero is reserved opcode */ \ 175 .dst_reg = 0, \ 176 .src_reg = 0, \ 177 .off = 0, \ 178 .imm = ((__u64) (IMM)) >> 32 }) 179 180 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 181 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 182 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 183 184 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 185 186 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 187 ((struct bpf_insn) { \ 188 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 189 .dst_reg = DST, \ 190 .src_reg = SRC, \ 191 .off = 0, \ 192 .imm = IMM }) 193 194 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 195 ((struct bpf_insn) { \ 196 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 197 .dst_reg = DST, \ 198 .src_reg = SRC, \ 199 .off = 0, \ 200 .imm = IMM }) 201 202 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 203 204 #define BPF_LD_ABS(SIZE, IMM) \ 205 ((struct bpf_insn) { \ 206 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 207 .dst_reg = 0, \ 208 .src_reg = 0, \ 209 .off = 0, \ 210 .imm = IMM }) 211 212 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 213 214 #define BPF_LD_IND(SIZE, SRC, IMM) \ 215 ((struct bpf_insn) { \ 216 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 217 .dst_reg = 0, \ 218 .src_reg = SRC, \ 219 .off = 0, \ 220 .imm = IMM }) 221 222 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 223 224 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 225 ((struct bpf_insn) { \ 226 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 227 .dst_reg = DST, \ 228 .src_reg = SRC, \ 229 .off = OFF, \ 230 .imm = 0 }) 231 232 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 233 234 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 235 ((struct bpf_insn) { \ 236 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 237 .dst_reg = DST, \ 238 .src_reg = SRC, \ 239 .off = OFF, \ 240 .imm = 0 }) 241 242 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 243 244 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 245 ((struct bpf_insn) { \ 246 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 247 .dst_reg = DST, \ 248 .src_reg = SRC, \ 249 .off = OFF, \ 250 .imm = 0 }) 251 252 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 253 254 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 255 ((struct bpf_insn) { \ 256 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 257 .dst_reg = DST, \ 258 .src_reg = 0, \ 259 .off = OFF, \ 260 .imm = IMM }) 261 262 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 263 264 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 265 ((struct bpf_insn) { \ 266 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 267 .dst_reg = DST, \ 268 .src_reg = SRC, \ 269 .off = OFF, \ 270 .imm = 0 }) 271 272 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 273 274 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 275 ((struct bpf_insn) { \ 276 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 277 .dst_reg = DST, \ 278 .src_reg = 0, \ 279 .off = OFF, \ 280 .imm = IMM }) 281 282 /* Unconditional jumps, goto pc + off16 */ 283 284 #define BPF_JMP_A(OFF) \ 285 ((struct bpf_insn) { \ 286 .code = BPF_JMP | BPF_JA, \ 287 .dst_reg = 0, \ 288 .src_reg = 0, \ 289 .off = OFF, \ 290 .imm = 0 }) 291 292 /* Function call */ 293 294 #define BPF_EMIT_CALL(FUNC) \ 295 ((struct bpf_insn) { \ 296 .code = BPF_JMP | BPF_CALL, \ 297 .dst_reg = 0, \ 298 .src_reg = 0, \ 299 .off = 0, \ 300 .imm = ((FUNC) - __bpf_call_base) }) 301 302 /* Raw code statement block */ 303 304 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 305 ((struct bpf_insn) { \ 306 .code = CODE, \ 307 .dst_reg = DST, \ 308 .src_reg = SRC, \ 309 .off = OFF, \ 310 .imm = IMM }) 311 312 /* Program exit */ 313 314 #define BPF_EXIT_INSN() \ 315 ((struct bpf_insn) { \ 316 .code = BPF_JMP | BPF_EXIT, \ 317 .dst_reg = 0, \ 318 .src_reg = 0, \ 319 .off = 0, \ 320 .imm = 0 }) 321 322 /* Internal classic blocks for direct assignment */ 323 324 #define __BPF_STMT(CODE, K) \ 325 ((struct sock_filter) BPF_STMT(CODE, K)) 326 327 #define __BPF_JUMP(CODE, K, JT, JF) \ 328 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 329 330 #define bytes_to_bpf_size(bytes) \ 331 ({ \ 332 int bpf_size = -EINVAL; \ 333 \ 334 if (bytes == sizeof(u8)) \ 335 bpf_size = BPF_B; \ 336 else if (bytes == sizeof(u16)) \ 337 bpf_size = BPF_H; \ 338 else if (bytes == sizeof(u32)) \ 339 bpf_size = BPF_W; \ 340 else if (bytes == sizeof(u64)) \ 341 bpf_size = BPF_DW; \ 342 \ 343 bpf_size; \ 344 }) 345 346 #define bpf_size_to_bytes(bpf_size) \ 347 ({ \ 348 int bytes = -EINVAL; \ 349 \ 350 if (bpf_size == BPF_B) \ 351 bytes = sizeof(u8); \ 352 else if (bpf_size == BPF_H) \ 353 bytes = sizeof(u16); \ 354 else if (bpf_size == BPF_W) \ 355 bytes = sizeof(u32); \ 356 else if (bpf_size == BPF_DW) \ 357 bytes = sizeof(u64); \ 358 \ 359 bytes; \ 360 }) 361 362 #define BPF_SIZEOF(type) \ 363 ({ \ 364 const int __size = bytes_to_bpf_size(sizeof(type)); \ 365 BUILD_BUG_ON(__size < 0); \ 366 __size; \ 367 }) 368 369 #define BPF_FIELD_SIZEOF(type, field) \ 370 ({ \ 371 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ 372 BUILD_BUG_ON(__size < 0); \ 373 __size; \ 374 }) 375 376 #define BPF_LDST_BYTES(insn) \ 377 ({ \ 378 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \ 379 WARN_ON(__size < 0); \ 380 __size; \ 381 }) 382 383 #define __BPF_MAP_0(m, v, ...) v 384 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a) 385 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__) 386 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__) 387 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__) 388 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__) 389 390 #define __BPF_REG_0(...) __BPF_PAD(5) 391 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4) 392 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3) 393 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2) 394 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1) 395 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__) 396 397 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__) 398 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__) 399 400 #define __BPF_CAST(t, a) \ 401 (__force t) \ 402 (__force \ 403 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \ 404 (unsigned long)0, (t)0))) a 405 #define __BPF_V void 406 #define __BPF_N 407 408 #define __BPF_DECL_ARGS(t, a) t a 409 #define __BPF_DECL_REGS(t, a) u64 a 410 411 #define __BPF_PAD(n) \ 412 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \ 413 u64, __ur_3, u64, __ur_4, u64, __ur_5) 414 415 #define BPF_CALL_x(x, name, ...) \ 416 static __always_inline \ 417 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ 418 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ 419 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ 420 { \ 421 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ 422 } \ 423 static __always_inline \ 424 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) 425 426 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__) 427 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) 428 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__) 429 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__) 430 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__) 431 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__) 432 433 #define bpf_ctx_range(TYPE, MEMBER) \ 434 offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 435 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \ 436 offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1 437 438 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ 439 ({ \ 440 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \ 441 *(PTR_SIZE) = (SIZE); \ 442 offsetof(TYPE, MEMBER); \ 443 }) 444 445 #ifdef CONFIG_COMPAT 446 /* A struct sock_filter is architecture independent. */ 447 struct compat_sock_fprog { 448 u16 len; 449 compat_uptr_t filter; /* struct sock_filter * */ 450 }; 451 #endif 452 453 struct sock_fprog_kern { 454 u16 len; 455 struct sock_filter *filter; 456 }; 457 458 struct bpf_binary_header { 459 unsigned int pages; 460 u8 image[]; 461 }; 462 463 struct bpf_prog { 464 u16 pages; /* Number of allocated pages */ 465 u16 jited:1, /* Is our filter JIT'ed? */ 466 jit_requested:1,/* archs need to JIT the prog */ 467 locked:1, /* Program image locked? */ 468 gpl_compatible:1, /* Is filter GPL compatible? */ 469 cb_access:1, /* Is control block accessed? */ 470 dst_needed:1, /* Do we need dst entry? */ 471 blinded:1, /* Was blinded */ 472 is_func:1, /* program is a bpf function */ 473 kprobe_override:1, /* Do we override a kprobe? */ 474 has_callchain_buf:1; /* callchain buffer allocated? */ 475 enum bpf_prog_type type; /* Type of BPF program */ 476 enum bpf_attach_type expected_attach_type; /* For some prog types */ 477 u32 len; /* Number of filter blocks */ 478 u32 jited_len; /* Size of jited insns in bytes */ 479 u8 tag[BPF_TAG_SIZE]; 480 struct bpf_prog_aux *aux; /* Auxiliary fields */ 481 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 482 unsigned int (*bpf_func)(const void *ctx, 483 const struct bpf_insn *insn); 484 /* Instructions for interpreter */ 485 union { 486 struct sock_filter insns[0]; 487 struct bpf_insn insnsi[0]; 488 }; 489 }; 490 491 struct sk_filter { 492 refcount_t refcnt; 493 struct rcu_head rcu; 494 struct bpf_prog *prog; 495 }; 496 497 #define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi) 498 499 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN 500 501 struct bpf_skb_data_end { 502 struct qdisc_skb_cb qdisc_cb; 503 void *data_meta; 504 void *data_end; 505 }; 506 507 struct sk_msg_buff { 508 void *data; 509 void *data_end; 510 __u32 apply_bytes; 511 __u32 cork_bytes; 512 int sg_copybreak; 513 int sg_start; 514 int sg_curr; 515 int sg_end; 516 struct scatterlist sg_data[MAX_SKB_FRAGS]; 517 bool sg_copy[MAX_SKB_FRAGS]; 518 __u32 flags; 519 struct sock *sk_redir; 520 struct sk_buff *skb; 521 struct list_head list; 522 }; 523 524 /* Compute the linear packet data range [data, data_end) which 525 * will be accessed by various program types (cls_bpf, act_bpf, 526 * lwt, ...). Subsystems allowing direct data access must (!) 527 * ensure that cb[] area can be written to when BPF program is 528 * invoked (otherwise cb[] save/restore is necessary). 529 */ 530 static inline void bpf_compute_data_pointers(struct sk_buff *skb) 531 { 532 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; 533 534 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb)); 535 cb->data_meta = skb->data - skb_metadata_len(skb); 536 cb->data_end = skb->data + skb_headlen(skb); 537 } 538 539 static inline u8 *bpf_skb_cb(struct sk_buff *skb) 540 { 541 /* eBPF programs may read/write skb->cb[] area to transfer meta 542 * data between tail calls. Since this also needs to work with 543 * tc, that scratch memory is mapped to qdisc_skb_cb's data area. 544 * 545 * In some socket filter cases, the cb unfortunately needs to be 546 * saved/restored so that protocol specific skb->cb[] data won't 547 * be lost. In any case, due to unpriviledged eBPF programs 548 * attached to sockets, we need to clear the bpf_skb_cb() area 549 * to not leak previous contents to user space. 550 */ 551 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN); 552 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 553 FIELD_SIZEOF(struct qdisc_skb_cb, data)); 554 555 return qdisc_skb_cb(skb)->data; 556 } 557 558 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 559 struct sk_buff *skb) 560 { 561 u8 *cb_data = bpf_skb_cb(skb); 562 u8 cb_saved[BPF_SKB_CB_LEN]; 563 u32 res; 564 565 if (unlikely(prog->cb_access)) { 566 memcpy(cb_saved, cb_data, sizeof(cb_saved)); 567 memset(cb_data, 0, sizeof(cb_saved)); 568 } 569 570 res = BPF_PROG_RUN(prog, skb); 571 572 if (unlikely(prog->cb_access)) 573 memcpy(cb_data, cb_saved, sizeof(cb_saved)); 574 575 return res; 576 } 577 578 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 579 struct sk_buff *skb) 580 { 581 u8 *cb_data = bpf_skb_cb(skb); 582 583 if (unlikely(prog->cb_access)) 584 memset(cb_data, 0, BPF_SKB_CB_LEN); 585 586 return BPF_PROG_RUN(prog, skb); 587 } 588 589 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, 590 struct xdp_buff *xdp) 591 { 592 /* Caller needs to hold rcu_read_lock() (!), otherwise program 593 * can be released while still running, or map elements could be 594 * freed early while still having concurrent users. XDP fastpath 595 * already takes rcu_read_lock() when fetching the program, so 596 * it's not necessary here anymore. 597 */ 598 return BPF_PROG_RUN(prog, xdp); 599 } 600 601 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) 602 { 603 return prog->len * sizeof(struct bpf_insn); 604 } 605 606 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) 607 { 608 return round_up(bpf_prog_insn_size(prog) + 609 sizeof(__be64) + 1, SHA_MESSAGE_BYTES); 610 } 611 612 static inline unsigned int bpf_prog_size(unsigned int proglen) 613 { 614 return max(sizeof(struct bpf_prog), 615 offsetof(struct bpf_prog, insns[proglen])); 616 } 617 618 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 619 { 620 /* When classic BPF programs have been loaded and the arch 621 * does not have a classic BPF JIT (anymore), they have been 622 * converted via bpf_migrate_filter() to eBPF and thus always 623 * have an unspec program type. 624 */ 625 return prog->type == BPF_PROG_TYPE_UNSPEC; 626 } 627 628 static inline bool 629 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default) 630 { 631 bool off_ok; 632 #ifdef __LITTLE_ENDIAN 633 off_ok = (off & (size_default - 1)) == 0; 634 #else 635 off_ok = (off & (size_default - 1)) + size == size_default; 636 #endif 637 return off_ok && size <= size_default && (size & (size - 1)) == 0; 638 } 639 640 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 641 642 #ifdef CONFIG_ARCH_HAS_SET_MEMORY 643 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 644 { 645 fp->locked = 1; 646 WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages)); 647 } 648 649 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 650 { 651 if (fp->locked) { 652 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages)); 653 /* In case set_memory_rw() fails, we want to be the first 654 * to crash here instead of some random place later on. 655 */ 656 fp->locked = 0; 657 } 658 } 659 660 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 661 { 662 WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages)); 663 } 664 665 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 666 { 667 WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages)); 668 } 669 #else 670 static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 671 { 672 } 673 674 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 675 { 676 } 677 678 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) 679 { 680 } 681 682 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr) 683 { 684 } 685 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */ 686 687 static inline struct bpf_binary_header * 688 bpf_jit_binary_hdr(const struct bpf_prog *fp) 689 { 690 unsigned long real_start = (unsigned long)fp->bpf_func; 691 unsigned long addr = real_start & PAGE_MASK; 692 693 return (void *)addr; 694 } 695 696 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); 697 static inline int sk_filter(struct sock *sk, struct sk_buff *skb) 698 { 699 return sk_filter_trim_cap(sk, skb, 1); 700 } 701 702 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err); 703 void bpf_prog_free(struct bpf_prog *fp); 704 705 bool bpf_opcode_in_insntable(u8 code); 706 707 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 708 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 709 gfp_t gfp_extra_flags); 710 void __bpf_prog_free(struct bpf_prog *fp); 711 712 static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 713 { 714 bpf_prog_unlock_ro(fp); 715 __bpf_prog_free(fp); 716 } 717 718 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 719 unsigned int flen); 720 721 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 722 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 723 bpf_aux_classic_check_t trans, bool save_orig); 724 void bpf_prog_destroy(struct bpf_prog *fp); 725 726 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 727 int sk_attach_bpf(u32 ufd, struct sock *sk); 728 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); 729 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); 730 int sk_detach_filter(struct sock *sk); 731 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 732 unsigned int len); 733 734 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 735 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 736 737 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 738 #define __bpf_call_base_args \ 739 ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \ 740 __bpf_call_base) 741 742 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); 743 void bpf_jit_compile(struct bpf_prog *prog); 744 bool bpf_helper_changes_pkt_data(void *func); 745 746 static inline bool bpf_dump_raw_ok(void) 747 { 748 /* Reconstruction of call-sites is dependent on kallsyms, 749 * thus make dump the same restriction. 750 */ 751 return kallsyms_show_value() == 1; 752 } 753 754 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 755 const struct bpf_insn *patch, u32 len); 756 757 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the 758 * same cpu context. Further for best results no more than a single map 759 * for the do_redirect/do_flush pair should be used. This limitation is 760 * because we only track one map and force a flush when the map changes. 761 * This does not appear to be a real limitation for existing software. 762 */ 763 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, 764 struct xdp_buff *xdp, struct bpf_prog *prog); 765 int xdp_do_redirect(struct net_device *dev, 766 struct xdp_buff *xdp, 767 struct bpf_prog *prog); 768 void xdp_do_flush_map(void); 769 770 void bpf_warn_invalid_xdp_action(u32 act); 771 772 struct sock *do_sk_redirect_map(struct sk_buff *skb); 773 struct sock *do_msg_redirect_map(struct sk_msg_buff *md); 774 775 #ifdef CONFIG_BPF_JIT 776 extern int bpf_jit_enable; 777 extern int bpf_jit_harden; 778 extern int bpf_jit_kallsyms; 779 780 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 781 782 struct bpf_binary_header * 783 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 784 unsigned int alignment, 785 bpf_jit_fill_hole_t bpf_fill_ill_insns); 786 void bpf_jit_binary_free(struct bpf_binary_header *hdr); 787 788 void bpf_jit_free(struct bpf_prog *fp); 789 790 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp); 791 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other); 792 793 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 794 u32 pass, void *image) 795 { 796 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 797 proglen, pass, image, current->comm, task_pid_nr(current)); 798 799 if (image) 800 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 801 16, 1, image, proglen, false); 802 } 803 804 static inline bool bpf_jit_is_ebpf(void) 805 { 806 # ifdef CONFIG_HAVE_EBPF_JIT 807 return true; 808 # else 809 return false; 810 # endif 811 } 812 813 static inline bool ebpf_jit_enabled(void) 814 { 815 return bpf_jit_enable && bpf_jit_is_ebpf(); 816 } 817 818 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 819 { 820 return fp->jited && bpf_jit_is_ebpf(); 821 } 822 823 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) 824 { 825 /* These are the prerequisites, should someone ever have the 826 * idea to call blinding outside of them, we make sure to 827 * bail out. 828 */ 829 if (!bpf_jit_is_ebpf()) 830 return false; 831 if (!prog->jit_requested) 832 return false; 833 if (!bpf_jit_harden) 834 return false; 835 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) 836 return false; 837 838 return true; 839 } 840 841 static inline bool bpf_jit_kallsyms_enabled(void) 842 { 843 /* There are a couple of corner cases where kallsyms should 844 * not be enabled f.e. on hardening. 845 */ 846 if (bpf_jit_harden) 847 return false; 848 if (!bpf_jit_kallsyms) 849 return false; 850 if (bpf_jit_kallsyms == 1) 851 return true; 852 853 return false; 854 } 855 856 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 857 unsigned long *off, char *sym); 858 bool is_bpf_text_address(unsigned long addr); 859 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 860 char *sym); 861 862 static inline const char * 863 bpf_address_lookup(unsigned long addr, unsigned long *size, 864 unsigned long *off, char **modname, char *sym) 865 { 866 const char *ret = __bpf_address_lookup(addr, size, off, sym); 867 868 if (ret && modname) 869 *modname = NULL; 870 return ret; 871 } 872 873 void bpf_prog_kallsyms_add(struct bpf_prog *fp); 874 void bpf_prog_kallsyms_del(struct bpf_prog *fp); 875 876 #else /* CONFIG_BPF_JIT */ 877 878 static inline bool ebpf_jit_enabled(void) 879 { 880 return false; 881 } 882 883 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) 884 { 885 return false; 886 } 887 888 static inline void bpf_jit_free(struct bpf_prog *fp) 889 { 890 bpf_prog_unlock_free(fp); 891 } 892 893 static inline bool bpf_jit_kallsyms_enabled(void) 894 { 895 return false; 896 } 897 898 static inline const char * 899 __bpf_address_lookup(unsigned long addr, unsigned long *size, 900 unsigned long *off, char *sym) 901 { 902 return NULL; 903 } 904 905 static inline bool is_bpf_text_address(unsigned long addr) 906 { 907 return false; 908 } 909 910 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, 911 char *type, char *sym) 912 { 913 return -ERANGE; 914 } 915 916 static inline const char * 917 bpf_address_lookup(unsigned long addr, unsigned long *size, 918 unsigned long *off, char **modname, char *sym) 919 { 920 return NULL; 921 } 922 923 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) 924 { 925 } 926 927 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp) 928 { 929 } 930 #endif /* CONFIG_BPF_JIT */ 931 932 #define BPF_ANC BIT(15) 933 934 static inline bool bpf_needs_clear_a(const struct sock_filter *first) 935 { 936 switch (first->code) { 937 case BPF_RET | BPF_K: 938 case BPF_LD | BPF_W | BPF_LEN: 939 return false; 940 941 case BPF_LD | BPF_W | BPF_ABS: 942 case BPF_LD | BPF_H | BPF_ABS: 943 case BPF_LD | BPF_B | BPF_ABS: 944 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 945 return true; 946 return false; 947 948 default: 949 return true; 950 } 951 } 952 953 static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 954 { 955 BUG_ON(ftest->code & BPF_ANC); 956 957 switch (ftest->code) { 958 case BPF_LD | BPF_W | BPF_ABS: 959 case BPF_LD | BPF_H | BPF_ABS: 960 case BPF_LD | BPF_B | BPF_ABS: 961 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 962 return BPF_ANC | SKF_AD_##CODE 963 switch (ftest->k) { 964 BPF_ANCILLARY(PROTOCOL); 965 BPF_ANCILLARY(PKTTYPE); 966 BPF_ANCILLARY(IFINDEX); 967 BPF_ANCILLARY(NLATTR); 968 BPF_ANCILLARY(NLATTR_NEST); 969 BPF_ANCILLARY(MARK); 970 BPF_ANCILLARY(QUEUE); 971 BPF_ANCILLARY(HATYPE); 972 BPF_ANCILLARY(RXHASH); 973 BPF_ANCILLARY(CPU); 974 BPF_ANCILLARY(ALU_XOR_X); 975 BPF_ANCILLARY(VLAN_TAG); 976 BPF_ANCILLARY(VLAN_TAG_PRESENT); 977 BPF_ANCILLARY(PAY_OFFSET); 978 BPF_ANCILLARY(RANDOM); 979 BPF_ANCILLARY(VLAN_TPID); 980 } 981 /* Fallthrough. */ 982 default: 983 return ftest->code; 984 } 985 } 986 987 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 988 int k, unsigned int size); 989 990 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 991 unsigned int size, void *buffer) 992 { 993 if (k >= 0) 994 return skb_header_pointer(skb, k, size, buffer); 995 996 return bpf_internal_load_pointer_neg_helper(skb, k, size); 997 } 998 999 static inline int bpf_tell_extensions(void) 1000 { 1001 return SKF_AD_MAX; 1002 } 1003 1004 struct bpf_sock_addr_kern { 1005 struct sock *sk; 1006 struct sockaddr *uaddr; 1007 /* Temporary "register" to make indirect stores to nested structures 1008 * defined above. We need three registers to make such a store, but 1009 * only two (src and dst) are available at convert_ctx_access time 1010 */ 1011 u64 tmp_reg; 1012 }; 1013 1014 struct bpf_sock_ops_kern { 1015 struct sock *sk; 1016 u32 op; 1017 union { 1018 u32 args[4]; 1019 u32 reply; 1020 u32 replylong[4]; 1021 }; 1022 u32 is_fullsock; 1023 u64 temp; /* temp and everything after is not 1024 * initialized to 0 before calling 1025 * the BPF program. New fields that 1026 * should be initialized to 0 should 1027 * be inserted before temp. 1028 * temp is scratch storage used by 1029 * sock_ops_convert_ctx_access 1030 * as temporary storage of a register. 1031 */ 1032 }; 1033 1034 #endif /* __LINUX_FILTER_H__ */ 1035