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 <net/sch_generic.h> 17 18#include <asm/cacheflush.h> 19 20#include <uapi/linux/filter.h> 21#include <uapi/linux/bpf.h> 22 23struct sk_buff; 24struct sock; 25struct seccomp_data; 26struct bpf_prog_aux; 27 28/* ArgX, context and stack frame pointer register positions. Note, 29 * Arg1, Arg2, Arg3, etc are used as argument mappings of function 30 * calls in BPF_CALL instruction. 31 */ 32#define BPF_REG_ARG1 BPF_REG_1 33#define BPF_REG_ARG2 BPF_REG_2 34#define BPF_REG_ARG3 BPF_REG_3 35#define BPF_REG_ARG4 BPF_REG_4 36#define BPF_REG_ARG5 BPF_REG_5 37#define BPF_REG_CTX BPF_REG_6 38#define BPF_REG_FP BPF_REG_10 39 40/* Additional register mappings for converted user programs. */ 41#define BPF_REG_A BPF_REG_0 42#define BPF_REG_X BPF_REG_7 43#define BPF_REG_TMP BPF_REG_8 44 45/* BPF program can access up to 512 bytes of stack space. */ 46#define MAX_BPF_STACK 512 47 48/* Helper macros for filter block array initializers. */ 49 50/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ 51 52#define BPF_ALU64_REG(OP, DST, SRC) \ 53 ((struct bpf_insn) { \ 54 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ 55 .dst_reg = DST, \ 56 .src_reg = SRC, \ 57 .off = 0, \ 58 .imm = 0 }) 59 60#define BPF_ALU32_REG(OP, DST, SRC) \ 61 ((struct bpf_insn) { \ 62 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ 63 .dst_reg = DST, \ 64 .src_reg = SRC, \ 65 .off = 0, \ 66 .imm = 0 }) 67 68/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ 69 70#define BPF_ALU64_IMM(OP, DST, IMM) \ 71 ((struct bpf_insn) { \ 72 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ 73 .dst_reg = DST, \ 74 .src_reg = 0, \ 75 .off = 0, \ 76 .imm = IMM }) 77 78#define BPF_ALU32_IMM(OP, DST, IMM) \ 79 ((struct bpf_insn) { \ 80 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ 81 .dst_reg = DST, \ 82 .src_reg = 0, \ 83 .off = 0, \ 84 .imm = IMM }) 85 86/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ 87 88#define BPF_ENDIAN(TYPE, DST, LEN) \ 89 ((struct bpf_insn) { \ 90 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ 91 .dst_reg = DST, \ 92 .src_reg = 0, \ 93 .off = 0, \ 94 .imm = LEN }) 95 96/* Short form of mov, dst_reg = src_reg */ 97 98#define BPF_MOV64_REG(DST, SRC) \ 99 ((struct bpf_insn) { \ 100 .code = BPF_ALU64 | BPF_MOV | BPF_X, \ 101 .dst_reg = DST, \ 102 .src_reg = SRC, \ 103 .off = 0, \ 104 .imm = 0 }) 105 106#define BPF_MOV32_REG(DST, SRC) \ 107 ((struct bpf_insn) { \ 108 .code = BPF_ALU | BPF_MOV | BPF_X, \ 109 .dst_reg = DST, \ 110 .src_reg = SRC, \ 111 .off = 0, \ 112 .imm = 0 }) 113 114/* Short form of mov, dst_reg = imm32 */ 115 116#define BPF_MOV64_IMM(DST, IMM) \ 117 ((struct bpf_insn) { \ 118 .code = BPF_ALU64 | BPF_MOV | BPF_K, \ 119 .dst_reg = DST, \ 120 .src_reg = 0, \ 121 .off = 0, \ 122 .imm = IMM }) 123 124#define BPF_MOV32_IMM(DST, IMM) \ 125 ((struct bpf_insn) { \ 126 .code = BPF_ALU | BPF_MOV | BPF_K, \ 127 .dst_reg = DST, \ 128 .src_reg = 0, \ 129 .off = 0, \ 130 .imm = IMM }) 131 132/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 133#define BPF_LD_IMM64(DST, IMM) \ 134 BPF_LD_IMM64_RAW(DST, 0, IMM) 135 136#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 137 ((struct bpf_insn) { \ 138 .code = BPF_LD | BPF_DW | BPF_IMM, \ 139 .dst_reg = DST, \ 140 .src_reg = SRC, \ 141 .off = 0, \ 142 .imm = (__u32) (IMM) }), \ 143 ((struct bpf_insn) { \ 144 .code = 0, /* zero is reserved opcode */ \ 145 .dst_reg = 0, \ 146 .src_reg = 0, \ 147 .off = 0, \ 148 .imm = ((__u64) (IMM)) >> 32 }) 149 150/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 151#define BPF_LD_MAP_FD(DST, MAP_FD) \ 152 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) 153 154/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ 155 156#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ 157 ((struct bpf_insn) { \ 158 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ 159 .dst_reg = DST, \ 160 .src_reg = SRC, \ 161 .off = 0, \ 162 .imm = IMM }) 163 164#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ 165 ((struct bpf_insn) { \ 166 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ 167 .dst_reg = DST, \ 168 .src_reg = SRC, \ 169 .off = 0, \ 170 .imm = IMM }) 171 172/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ 173 174#define BPF_LD_ABS(SIZE, IMM) \ 175 ((struct bpf_insn) { \ 176 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ 177 .dst_reg = 0, \ 178 .src_reg = 0, \ 179 .off = 0, \ 180 .imm = IMM }) 181 182/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ 183 184#define BPF_LD_IND(SIZE, SRC, IMM) \ 185 ((struct bpf_insn) { \ 186 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ 187 .dst_reg = 0, \ 188 .src_reg = SRC, \ 189 .off = 0, \ 190 .imm = IMM }) 191 192/* Memory load, dst_reg = *(uint *) (src_reg + off16) */ 193 194#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ 195 ((struct bpf_insn) { \ 196 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ 197 .dst_reg = DST, \ 198 .src_reg = SRC, \ 199 .off = OFF, \ 200 .imm = 0 }) 201 202/* Memory store, *(uint *) (dst_reg + off16) = src_reg */ 203 204#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ 205 ((struct bpf_insn) { \ 206 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ 207 .dst_reg = DST, \ 208 .src_reg = SRC, \ 209 .off = OFF, \ 210 .imm = 0 }) 211 212/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ 213 214#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ 215 ((struct bpf_insn) { \ 216 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ 217 .dst_reg = DST, \ 218 .src_reg = SRC, \ 219 .off = OFF, \ 220 .imm = 0 }) 221 222/* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 223 224#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 225 ((struct bpf_insn) { \ 226 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 227 .dst_reg = DST, \ 228 .src_reg = 0, \ 229 .off = OFF, \ 230 .imm = IMM }) 231 232/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 233 234#define BPF_JMP_REG(OP, DST, SRC, OFF) \ 235 ((struct bpf_insn) { \ 236 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 237 .dst_reg = DST, \ 238 .src_reg = SRC, \ 239 .off = OFF, \ 240 .imm = 0 }) 241 242/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 243 244#define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 245 ((struct bpf_insn) { \ 246 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 247 .dst_reg = DST, \ 248 .src_reg = 0, \ 249 .off = OFF, \ 250 .imm = IMM }) 251 252/* Function call */ 253 254#define BPF_EMIT_CALL(FUNC) \ 255 ((struct bpf_insn) { \ 256 .code = BPF_JMP | BPF_CALL, \ 257 .dst_reg = 0, \ 258 .src_reg = 0, \ 259 .off = 0, \ 260 .imm = ((FUNC) - __bpf_call_base) }) 261 262/* Raw code statement block */ 263 264#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 265 ((struct bpf_insn) { \ 266 .code = CODE, \ 267 .dst_reg = DST, \ 268 .src_reg = SRC, \ 269 .off = OFF, \ 270 .imm = IMM }) 271 272/* Program exit */ 273 274#define BPF_EXIT_INSN() \ 275 ((struct bpf_insn) { \ 276 .code = BPF_JMP | BPF_EXIT, \ 277 .dst_reg = 0, \ 278 .src_reg = 0, \ 279 .off = 0, \ 280 .imm = 0 }) 281 282/* Internal classic blocks for direct assignment */ 283 284#define __BPF_STMT(CODE, K) \ 285 ((struct sock_filter) BPF_STMT(CODE, K)) 286 287#define __BPF_JUMP(CODE, K, JT, JF) \ 288 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF)) 289 290#define bytes_to_bpf_size(bytes) \ 291({ \ 292 int bpf_size = -EINVAL; \ 293 \ 294 if (bytes == sizeof(u8)) \ 295 bpf_size = BPF_B; \ 296 else if (bytes == sizeof(u16)) \ 297 bpf_size = BPF_H; \ 298 else if (bytes == sizeof(u32)) \ 299 bpf_size = BPF_W; \ 300 else if (bytes == sizeof(u64)) \ 301 bpf_size = BPF_DW; \ 302 \ 303 bpf_size; \ 304}) 305 306#ifdef CONFIG_COMPAT 307/* A struct sock_filter is architecture independent. */ 308struct compat_sock_fprog { 309 u16 len; 310 compat_uptr_t filter; /* struct sock_filter * */ 311}; 312#endif 313 314struct sock_fprog_kern { 315 u16 len; 316 struct sock_filter *filter; 317}; 318 319struct bpf_binary_header { 320 unsigned int pages; 321 u8 image[]; 322}; 323 324struct bpf_prog { 325 u16 pages; /* Number of allocated pages */ 326 kmemcheck_bitfield_begin(meta); 327 u16 jited:1, /* Is our filter JIT'ed? */ 328 gpl_compatible:1, /* Is filter GPL compatible? */ 329 cb_access:1, /* Is control block accessed? */ 330 dst_needed:1; /* Do we need dst entry? */ 331 kmemcheck_bitfield_end(meta); 332 u32 len; /* Number of filter blocks */ 333 enum bpf_prog_type type; /* Type of BPF program */ 334 struct bpf_prog_aux *aux; /* Auxiliary fields */ 335 struct sock_fprog_kern *orig_prog; /* Original BPF program */ 336 unsigned int (*bpf_func)(const struct sk_buff *skb, 337 const struct bpf_insn *filter); 338 /* Instructions for interpreter */ 339 union { 340 struct sock_filter insns[0]; 341 struct bpf_insn insnsi[0]; 342 }; 343}; 344 345struct sk_filter { 346 atomic_t refcnt; 347 struct rcu_head rcu; 348 struct bpf_prog *prog; 349}; 350 351#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) 352 353static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, 354 struct sk_buff *skb) 355{ 356 u8 *cb_data = qdisc_skb_cb(skb)->data; 357 u8 saved_cb[QDISC_CB_PRIV_LEN]; 358 u32 res; 359 360 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != 361 QDISC_CB_PRIV_LEN); 362 363 if (unlikely(prog->cb_access)) { 364 memcpy(saved_cb, cb_data, sizeof(saved_cb)); 365 memset(cb_data, 0, sizeof(saved_cb)); 366 } 367 368 res = BPF_PROG_RUN(prog, skb); 369 370 if (unlikely(prog->cb_access)) 371 memcpy(cb_data, saved_cb, sizeof(saved_cb)); 372 373 return res; 374} 375 376static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog, 377 struct sk_buff *skb) 378{ 379 u8 *cb_data = qdisc_skb_cb(skb)->data; 380 381 if (unlikely(prog->cb_access)) 382 memset(cb_data, 0, QDISC_CB_PRIV_LEN); 383 return BPF_PROG_RUN(prog, skb); 384} 385 386static inline unsigned int bpf_prog_size(unsigned int proglen) 387{ 388 return max(sizeof(struct bpf_prog), 389 offsetof(struct bpf_prog, insns[proglen])); 390} 391 392static inline bool bpf_prog_was_classic(const struct bpf_prog *prog) 393{ 394 /* When classic BPF programs have been loaded and the arch 395 * does not have a classic BPF JIT (anymore), they have been 396 * converted via bpf_migrate_filter() to eBPF and thus always 397 * have an unspec program type. 398 */ 399 return prog->type == BPF_PROG_TYPE_UNSPEC; 400} 401 402#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) 403 404#ifdef CONFIG_DEBUG_SET_MODULE_RONX 405static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 406{ 407 set_memory_ro((unsigned long)fp, fp->pages); 408} 409 410static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 411{ 412 set_memory_rw((unsigned long)fp, fp->pages); 413} 414#else 415static inline void bpf_prog_lock_ro(struct bpf_prog *fp) 416{ 417} 418 419static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 420{ 421} 422#endif /* CONFIG_DEBUG_SET_MODULE_RONX */ 423 424int sk_filter(struct sock *sk, struct sk_buff *skb); 425 426int bpf_prog_select_runtime(struct bpf_prog *fp); 427void bpf_prog_free(struct bpf_prog *fp); 428 429struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); 430struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 431 gfp_t gfp_extra_flags); 432void __bpf_prog_free(struct bpf_prog *fp); 433 434static inline void bpf_prog_unlock_free(struct bpf_prog *fp) 435{ 436 bpf_prog_unlock_ro(fp); 437 __bpf_prog_free(fp); 438} 439 440typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter, 441 unsigned int flen); 442 443int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); 444int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, 445 bpf_aux_classic_check_t trans, bool save_orig); 446void bpf_prog_destroy(struct bpf_prog *fp); 447 448int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 449int __sk_attach_filter(struct sock_fprog *fprog, struct sock *sk, 450 bool locked); 451int sk_attach_bpf(u32 ufd, struct sock *sk); 452int sk_detach_filter(struct sock *sk); 453int __sk_detach_filter(struct sock *sk, bool locked); 454 455int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, 456 unsigned int len); 457 458bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); 459void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 460 461u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 462void bpf_int_jit_compile(struct bpf_prog *fp); 463bool bpf_helper_changes_skb_data(void *func); 464 465#ifdef CONFIG_BPF_JIT 466typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); 467 468struct bpf_binary_header * 469bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 470 unsigned int alignment, 471 bpf_jit_fill_hole_t bpf_fill_ill_insns); 472void bpf_jit_binary_free(struct bpf_binary_header *hdr); 473 474void bpf_jit_compile(struct bpf_prog *fp); 475void bpf_jit_free(struct bpf_prog *fp); 476 477static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, 478 u32 pass, void *image) 479{ 480 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen, 481 proglen, pass, image, current->comm, task_pid_nr(current)); 482 483 if (image) 484 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, 485 16, 1, image, proglen, false); 486} 487#else 488static inline void bpf_jit_compile(struct bpf_prog *fp) 489{ 490} 491 492static inline void bpf_jit_free(struct bpf_prog *fp) 493{ 494 bpf_prog_unlock_free(fp); 495} 496#endif /* CONFIG_BPF_JIT */ 497 498#define BPF_ANC BIT(15) 499 500static inline bool bpf_needs_clear_a(const struct sock_filter *first) 501{ 502 switch (first->code) { 503 case BPF_RET | BPF_K: 504 case BPF_LD | BPF_W | BPF_LEN: 505 return false; 506 507 case BPF_LD | BPF_W | BPF_ABS: 508 case BPF_LD | BPF_H | BPF_ABS: 509 case BPF_LD | BPF_B | BPF_ABS: 510 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X) 511 return true; 512 return false; 513 514 default: 515 return true; 516 } 517} 518 519static inline u16 bpf_anc_helper(const struct sock_filter *ftest) 520{ 521 BUG_ON(ftest->code & BPF_ANC); 522 523 switch (ftest->code) { 524 case BPF_LD | BPF_W | BPF_ABS: 525 case BPF_LD | BPF_H | BPF_ABS: 526 case BPF_LD | BPF_B | BPF_ABS: 527#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ 528 return BPF_ANC | SKF_AD_##CODE 529 switch (ftest->k) { 530 BPF_ANCILLARY(PROTOCOL); 531 BPF_ANCILLARY(PKTTYPE); 532 BPF_ANCILLARY(IFINDEX); 533 BPF_ANCILLARY(NLATTR); 534 BPF_ANCILLARY(NLATTR_NEST); 535 BPF_ANCILLARY(MARK); 536 BPF_ANCILLARY(QUEUE); 537 BPF_ANCILLARY(HATYPE); 538 BPF_ANCILLARY(RXHASH); 539 BPF_ANCILLARY(CPU); 540 BPF_ANCILLARY(ALU_XOR_X); 541 BPF_ANCILLARY(VLAN_TAG); 542 BPF_ANCILLARY(VLAN_TAG_PRESENT); 543 BPF_ANCILLARY(PAY_OFFSET); 544 BPF_ANCILLARY(RANDOM); 545 BPF_ANCILLARY(VLAN_TPID); 546 } 547 /* Fallthrough. */ 548 default: 549 return ftest->code; 550 } 551} 552 553void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, 554 int k, unsigned int size); 555 556static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 557 unsigned int size, void *buffer) 558{ 559 if (k >= 0) 560 return skb_header_pointer(skb, k, size, buffer); 561 562 return bpf_internal_load_pointer_neg_helper(skb, k, size); 563} 564 565static inline int bpf_tell_extensions(void) 566{ 567 return SKF_AD_MAX; 568} 569 570#endif /* __LINUX_FILTER_H__ */ 571