include/linux/filter.h

   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_8
  51
  52 /* Kernel hidden auxiliary/helper register for hardening step.
  53  * Only used by eBPF JITs. It's nothing more than a temporary
  54  * register that JITs use internally, only that here it's part
  55  * of eBPF instructions that have been rewritten for blinding
  56  * constants. See JIT pre-step in bpf_jit_blind_constants().
  57  */
  58 #define BPF_REG_AX              MAX_BPF_REG
  59 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
  60
  61 /* unused opcode to mark special call to bpf_tail_call() helper */
  62 #define BPF_TAIL_CALL   0xf0
  63
  64 /* unused opcode to mark call to interpreter with arguments */
  65 #define BPF_CALL_ARGS   0xe0
  66
  67 /* As per nm, we expose JITed images as text (code) section for
  68  * kallsyms. That way, tools like perf can find it to match
  69  * addresses.
  70  */
  71 #define BPF_SYM_ELF_TYPE        't'
  72
  73 /* BPF program can access up to 512 bytes of stack space. */
  74 #define MAX_BPF_STACK   512
  75
  76 /* Helper macros for filter block array initializers. */
  77
  78 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  79
  80 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  81         ((struct bpf_insn) {                                    \
  82                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  83                 .dst_reg = DST,                                 \
  84                 .src_reg = SRC,                                 \
  85                 .off   = 0,                                     \
  86                 .imm   = 0 })
  87
  88 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  89         ((struct bpf_insn) {                                    \
  90                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  91                 .dst_reg = DST,                                 \
  92                 .src_reg = SRC,                                 \
  93                 .off   = 0,                                     \
  94                 .imm   = 0 })
  95
  96 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  97
  98 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  99         ((struct bpf_insn) {                                    \
 100                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
 101                 .dst_reg = DST,                                 \
 102                 .src_reg = 0,                                   \
 103                 .off   = 0,                                     \
 104                 .imm   = IMM })
 105
 106 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
 107         ((struct bpf_insn) {                                    \
 108                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
 109                 .dst_reg = DST,                                 \
 110                 .src_reg = 0,                                   \
 111                 .off   = 0,                                     \
 112                 .imm   = IMM })
 113
 114 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
 115
 116 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
 117         ((struct bpf_insn) {                                    \
 118                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 119                 .dst_reg = DST,                                 \
 120                 .src_reg = 0,                                   \
 121                 .off   = 0,                                     \
 122                 .imm   = LEN })
 123
 124 /* Short form of mov, dst_reg = src_reg */
 125
 126 #define BPF_MOV64_REG(DST, SRC)                                 \
 127         ((struct bpf_insn) {                                    \
 128                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 129                 .dst_reg = DST,                                 \
 130                 .src_reg = SRC,                                 \
 131                 .off   = 0,                                     \
 132                 .imm   = 0 })
 133
 134 #define BPF_MOV32_REG(DST, SRC)                                 \
 135         ((struct bpf_insn) {                                    \
 136                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 137                 .dst_reg = DST,                                 \
 138                 .src_reg = SRC,                                 \
 139                 .off   = 0,                                     \
 140                 .imm   = 0 })
 141
 142 /* Short form of mov, dst_reg = imm32 */
 143
 144 #define BPF_MOV64_IMM(DST, IMM)                                 \
 145         ((struct bpf_insn) {                                    \
 146                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 147                 .dst_reg = DST,                                 \
 148                 .src_reg = 0,                                   \
 149                 .off   = 0,                                     \
 150                 .imm   = IMM })
 151
 152 #define BPF_MOV32_IMM(DST, IMM)                                 \
 153         ((struct bpf_insn) {                                    \
 154                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 155                 .dst_reg = DST,                                 \
 156                 .src_reg = 0,                                   \
 157                 .off   = 0,                                     \
 158                 .imm   = IMM })
 159
 160 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 161 #define BPF_LD_IMM64(DST, IMM)                                  \
 162         BPF_LD_IMM64_RAW(DST, 0, IMM)
 163
 164 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 165         ((struct bpf_insn) {                                    \
 166                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 167                 .dst_reg = DST,                                 \
 168                 .src_reg = SRC,                                 \
 169                 .off   = 0,                                     \
 170                 .imm   = (__u32) (IMM) }),                      \
 171         ((struct bpf_insn) {                                    \
 172                 .code  = 0, /* zero is reserved opcode */       \
 173                 .dst_reg = 0,                                   \
 174                 .src_reg = 0,                                   \
 175                 .off   = 0,                                     \
 176                 .imm   = ((__u64) (IMM)) >> 32 })
 177
 178 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 179 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 180         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 181
 182 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 183
 184 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 185         ((struct bpf_insn) {                                    \
 186                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 187                 .dst_reg = DST,                                 \
 188                 .src_reg = SRC,                                 \
 189                 .off   = 0,                                     \
 190                 .imm   = IMM })
 191
 192 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 193         ((struct bpf_insn) {                                    \
 194                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 195                 .dst_reg = DST,                                 \
 196                 .src_reg = SRC,                                 \
 197                 .off   = 0,                                     \
 198                 .imm   = IMM })
 199
 200 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 201
 202 #define BPF_LD_ABS(SIZE, IMM)                                   \
 203         ((struct bpf_insn) {                                    \
 204                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 205                 .dst_reg = 0,                                   \
 206                 .src_reg = 0,                                   \
 207                 .off   = 0,                                     \
 208                 .imm   = IMM })
 209
 210 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 211
 212 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 213         ((struct bpf_insn) {                                    \
 214                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 215                 .dst_reg = 0,                                   \
 216                 .src_reg = SRC,                                 \
 217                 .off   = 0,                                     \
 218                 .imm   = IMM })
 219
 220 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 221
 222 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 223         ((struct bpf_insn) {                                    \
 224                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 225                 .dst_reg = DST,                                 \
 226                 .src_reg = SRC,                                 \
 227                 .off   = OFF,                                   \
 228                 .imm   = 0 })
 229
 230 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 231
 232 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 233         ((struct bpf_insn) {                                    \
 234                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 235                 .dst_reg = DST,                                 \
 236                 .src_reg = SRC,                                 \
 237                 .off   = OFF,                                   \
 238                 .imm   = 0 })
 239
 240 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 241
 242 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 243         ((struct bpf_insn) {                                    \
 244                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 245                 .dst_reg = DST,                                 \
 246                 .src_reg = SRC,                                 \
 247                 .off   = OFF,                                   \
 248                 .imm   = 0 })
 249
 250 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 251
 252 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 253         ((struct bpf_insn) {                                    \
 254                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 255                 .dst_reg = DST,                                 \
 256                 .src_reg = 0,                                   \
 257                 .off   = OFF,                                   \
 258                 .imm   = IMM })
 259
 260 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 261
 262 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 263         ((struct bpf_insn) {                                    \
 264                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 265                 .dst_reg = DST,                                 \
 266                 .src_reg = SRC,                                 \
 267                 .off   = OFF,                                   \
 268                 .imm   = 0 })
 269
 270 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 271
 272 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 273         ((struct bpf_insn) {                                    \
 274                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 275                 .dst_reg = DST,                                 \
 276                 .src_reg = 0,                                   \
 277                 .off   = OFF,                                   \
 278                 .imm   = IMM })
 279
 280 /* Unconditional jumps, goto pc + off16 */
 281
 282 #define BPF_JMP_A(OFF)                                          \
 283         ((struct bpf_insn) {                                    \
 284                 .code  = BPF_JMP | BPF_JA,                      \
 285                 .dst_reg = 0,                                   \
 286                 .src_reg = 0,                                   \
 287                 .off   = OFF,                                   \
 288                 .imm   = 0 })
 289
 290 /* Function call */
 291
 292 #define BPF_EMIT_CALL(FUNC)                                     \
 293         ((struct bpf_insn) {                                    \
 294                 .code  = BPF_JMP | BPF_CALL,                    \
 295                 .dst_reg = 0,                                   \
 296                 .src_reg = 0,                                   \
 297                 .off   = 0,                                     \
 298                 .imm   = ((FUNC) - __bpf_call_base) })
 299
 300 /* Raw code statement block */
 301
 302 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 303         ((struct bpf_insn) {                                    \
 304                 .code  = CODE,                                  \
 305                 .dst_reg = DST,                                 \
 306                 .src_reg = SRC,                                 \
 307                 .off   = OFF,                                   \
 308                 .imm   = IMM })
 309
 310 /* Program exit */
 311
 312 #define BPF_EXIT_INSN()                                         \
 313         ((struct bpf_insn) {                                    \
 314                 .code  = BPF_JMP | BPF_EXIT,                    \
 315                 .dst_reg = 0,                                   \
 316                 .src_reg = 0,                                   \
 317                 .off   = 0,                                     \
 318                 .imm   = 0 })
 319
 320 /* Internal classic blocks for direct assignment */
 321
 322 #define __BPF_STMT(CODE, K)                                     \
 323         ((struct sock_filter) BPF_STMT(CODE, K))
 324
 325 #define __BPF_JUMP(CODE, K, JT, JF)                             \
 326         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 327
 328 #define bytes_to_bpf_size(bytes)                                \
 329 ({                                                              \
 330         int bpf_size = -EINVAL;                                 \
 331                                                                 \
 332         if (bytes == sizeof(u8))                                \
 333                 bpf_size = BPF_B;                               \
 334         else if (bytes == sizeof(u16))                          \
 335                 bpf_size = BPF_H;                               \
 336         else if (bytes == sizeof(u32))                          \
 337                 bpf_size = BPF_W;                               \
 338         else if (bytes == sizeof(u64))                          \
 339                 bpf_size = BPF_DW;                              \
 340                                                                 \
 341         bpf_size;                                               \
 342 })
 343
 344 #define bpf_size_to_bytes(bpf_size)                             \
 345 ({                                                              \
 346         int bytes = -EINVAL;                                    \
 347                                                                 \
 348         if (bpf_size == BPF_B)                                  \
 349                 bytes = sizeof(u8);                             \
 350         else if (bpf_size == BPF_H)                             \
 351                 bytes = sizeof(u16);                            \
 352         else if (bpf_size == BPF_W)                             \
 353                 bytes = sizeof(u32);                            \
 354         else if (bpf_size == BPF_DW)                            \
 355                 bytes = sizeof(u64);                            \
 356                                                                 \
 357         bytes;                                                  \
 358 })
 359
 360 #define BPF_SIZEOF(type)                                        \
 361         ({                                                      \
 362                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 363                 BUILD_BUG_ON(__size < 0);                       \
 364                 __size;                                         \
 365         })
 366
 367 #define BPF_FIELD_SIZEOF(type, field)                           \
 368         ({                                                      \
 369                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 370                 BUILD_BUG_ON(__size < 0);                       \
 371                 __size;                                         \
 372         })
 373
 374 #define BPF_LDST_BYTES(insn)                                    \
 375         ({                                                      \
 376                 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
 377                 WARN_ON(__size < 0);                            \
 378                 __size;                                         \
 379         })
 380
 381 #define __BPF_MAP_0(m, v, ...) v
 382 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 383 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 384 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 385 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 386 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 387
 388 #define __BPF_REG_0(...) __BPF_PAD(5)
 389 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 390 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 391 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 392 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 393 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 394
 395 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 396 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 397
 398 #define __BPF_CAST(t, a)                                                       \
 399         (__force t)                                                            \
 400         (__force                                                               \
 401          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 402                                       (unsigned long)0, (t)0))) a
 403 #define __BPF_V void
 404 #define __BPF_N
 405
 406 #define __BPF_DECL_ARGS(t, a) t   a
 407 #define __BPF_DECL_REGS(t, a) u64 a
 408
 409 #define __BPF_PAD(n)                                                           \
 410         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 411                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 412
 413 #define BPF_CALL_x(x, name, ...)                                               \
 414         static __always_inline                                                 \
 415         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 416         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 417         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 418         {                                                                      \
 419                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 420         }                                                                      \
 421         static __always_inline                                                 \
 422         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 423
 424 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 425 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 426 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 427 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 428 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 429 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 430
 431 #define bpf_ctx_range(TYPE, MEMBER)                                             \
 432         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 433 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)                              \
 434         offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
 435
 436 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)                            \
 437         ({                                                                      \
 438                 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE));             \
 439                 *(PTR_SIZE) = (SIZE);                                           \
 440                 offsetof(TYPE, MEMBER);                                         \
 441         })
 442
 443 #ifdef CONFIG_COMPAT
 444 /* A struct sock_filter is architecture independent. */
 445 struct compat_sock_fprog {
 446         u16             len;
 447         compat_uptr_t   filter; /* struct sock_filter * */
 448 };
 449 #endif
 450
 451 struct sock_fprog_kern {
 452         u16                     len;
 453         struct sock_filter      *filter;
 454 };
 455
 456 struct bpf_binary_header {
 457         unsigned int pages;
 458         u8 image[];
 459 };
 460
 461 struct bpf_prog {
 462         u16                     pages;          /* Number of allocated pages */
 463         u16                     jited:1,        /* Is our filter JIT'ed? */
 464                                 jit_requested:1,/* archs need to JIT the prog */
 465                                 locked:1,       /* Program image locked? */
 466                                 gpl_compatible:1, /* Is filter GPL compatible? */
 467                                 cb_access:1,    /* Is control block accessed? */
 468                                 dst_needed:1,   /* Do we need dst entry? */
 469                                 blinded:1,      /* Was blinded */
 470                                 is_func:1,      /* program is a bpf function */
 471                                 kprobe_override:1; /* Do we override a kprobe? */
 472         enum bpf_prog_type      type;           /* Type of BPF program */
 473         enum bpf_attach_type    expected_attach_type; /* For some prog types */
 474         u32                     len;            /* Number of filter blocks */
 475         u32                     jited_len;      /* Size of jited insns in bytes */
 476         u8                      tag[BPF_TAG_SIZE];
 477         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 478         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 479         unsigned int            (*bpf_func)(const void *ctx,
 480                                             const struct bpf_insn *insn);
 481         /* Instructions for interpreter */
 482         union {
 483                 struct sock_filter      insns[0];
 484                 struct bpf_insn         insnsi[0];
 485         };
 486 };
 487
 488 struct sk_filter {
 489         refcount_t      refcnt;
 490         struct rcu_head rcu;
 491         struct bpf_prog *prog;
 492 };
 493
 494 #define BPF_PROG_RUN(filter, ctx)  (*(filter)->bpf_func)(ctx, (filter)->insnsi)
 495
 496 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 497
 498 struct bpf_skb_data_end {
 499         struct qdisc_skb_cb qdisc_cb;
 500         void *data_meta;
 501         void *data_end;
 502 };
 503
 504 struct sk_msg_buff {
 505         void *data;
 506         void *data_end;
 507         __u32 apply_bytes;
 508         __u32 cork_bytes;
 509         int sg_copybreak;
 510         int sg_start;
 511         int sg_curr;
 512         int sg_end;
 513         struct scatterlist sg_data[MAX_SKB_FRAGS];
 514         bool sg_copy[MAX_SKB_FRAGS];
 515         __u32 key;
 516         __u32 flags;
 517         struct bpf_map *map;
 518         struct sk_buff *skb;
 519         struct list_head list;
 520 };
 521
 522 /* Compute the linear packet data range [data, data_end) which
 523  * will be accessed by various program types (cls_bpf, act_bpf,
 524  * lwt, ...). Subsystems allowing direct data access must (!)
 525  * ensure that cb[] area can be written to when BPF program is
 526  * invoked (otherwise cb[] save/restore is necessary).
 527  */
 528 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
 529 {
 530         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 531
 532         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 533         cb->data_meta = skb->data - skb_metadata_len(skb);
 534         cb->data_end  = skb->data + skb_headlen(skb);
 535 }
 536
 537 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 538 {
 539         /* eBPF programs may read/write skb->cb[] area to transfer meta
 540          * data between tail calls. Since this also needs to work with
 541          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 542          *
 543          * In some socket filter cases, the cb unfortunately needs to be
 544          * saved/restored so that protocol specific skb->cb[] data won't
 545          * be lost. In any case, due to unpriviledged eBPF programs
 546          * attached to sockets, we need to clear the bpf_skb_cb() area
 547          * to not leak previous contents to user space.
 548          */
 549         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 550         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 551                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
 552
 553         return qdisc_skb_cb(skb)->data;
 554 }
 555
 556 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 557                                        struct sk_buff *skb)
 558 {
 559         u8 *cb_data = bpf_skb_cb(skb);
 560         u8 cb_saved[BPF_SKB_CB_LEN];
 561         u32 res;
 562
 563         if (unlikely(prog->cb_access)) {
 564                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 565                 memset(cb_data, 0, sizeof(cb_saved));
 566         }
 567
 568         res = BPF_PROG_RUN(prog, skb);
 569
 570         if (unlikely(prog->cb_access))
 571                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 572
 573         return res;
 574 }
 575
 576 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 577                                         struct sk_buff *skb)
 578 {
 579         u8 *cb_data = bpf_skb_cb(skb);
 580
 581         if (unlikely(prog->cb_access))
 582                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 583
 584         return BPF_PROG_RUN(prog, skb);
 585 }
 586
 587 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 588                                             struct xdp_buff *xdp)
 589 {
 590         /* Caller needs to hold rcu_read_lock() (!), otherwise program
 591          * can be released while still running, or map elements could be
 592          * freed early while still having concurrent users. XDP fastpath
 593          * already takes rcu_read_lock() when fetching the program, so
 594          * it's not necessary here anymore.
 595          */
 596         return BPF_PROG_RUN(prog, xdp);
 597 }
 598
 599 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 600 {
 601         return prog->len * sizeof(struct bpf_insn);
 602 }
 603
 604 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 605 {
 606         return round_up(bpf_prog_insn_size(prog) +
 607                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 608 }
 609
 610 static inline unsigned int bpf_prog_size(unsigned int proglen)
 611 {
 612         return max(sizeof(struct bpf_prog),
 613                    offsetof(struct bpf_prog, insns[proglen]));
 614 }
 615
 616 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 617 {
 618         /* When classic BPF programs have been loaded and the arch
 619          * does not have a classic BPF JIT (anymore), they have been
 620          * converted via bpf_migrate_filter() to eBPF and thus always
 621          * have an unspec program type.
 622          */
 623         return prog->type == BPF_PROG_TYPE_UNSPEC;
 624 }
 625
 626 static inline bool
 627 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default)
 628 {
 629         bool off_ok;
 630 #ifdef __LITTLE_ENDIAN
 631         off_ok = (off & (size_default - 1)) == 0;
 632 #else
 633         off_ok = (off & (size_default - 1)) + size == size_default;
 634 #endif
 635         return off_ok && size <= size_default && (size & (size - 1)) == 0;
 636 }
 637
 638 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 639
 640 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
 641 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 642 {
 643         fp->locked = 1;
 644         WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
 645 }
 646
 647 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 648 {
 649         if (fp->locked) {
 650                 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
 651                 /* In case set_memory_rw() fails, we want to be the first
 652                  * to crash here instead of some random place later on.
 653                  */
 654                 fp->locked = 0;
 655         }
 656 }
 657
 658 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 659 {
 660         WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
 661 }
 662
 663 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 664 {
 665         WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
 666 }
 667 #else
 668 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 669 {
 670 }
 671
 672 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 673 {
 674 }
 675
 676 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 677 {
 678 }
 679
 680 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 681 {
 682 }
 683 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 684
 685 static inline struct bpf_binary_header *
 686 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 687 {
 688         unsigned long real_start = (unsigned long)fp->bpf_func;
 689         unsigned long addr = real_start & PAGE_MASK;
 690
 691         return (void *)addr;
 692 }
 693
 694 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 695 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 696 {
 697         return sk_filter_trim_cap(sk, skb, 1);
 698 }
 699
 700 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 701 void bpf_prog_free(struct bpf_prog *fp);
 702
 703 bool bpf_opcode_in_insntable(u8 code);
 704
 705 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 706 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 707                                   gfp_t gfp_extra_flags);
 708 void __bpf_prog_free(struct bpf_prog *fp);
 709
 710 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 711 {
 712         bpf_prog_unlock_ro(fp);
 713         __bpf_prog_free(fp);
 714 }
 715
 716 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 717                                        unsigned int flen);
 718
 719 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 720 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 721                               bpf_aux_classic_check_t trans, bool save_orig);
 722 void bpf_prog_destroy(struct bpf_prog *fp);
 723
 724 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 725 int sk_attach_bpf(u32 ufd, struct sock *sk);
 726 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 727 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 728 int sk_detach_filter(struct sock *sk);
 729 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 730                   unsigned int len);
 731
 732 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 733 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 734
 735 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 736 #define __bpf_call_base_args \
 737         ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
 738          __bpf_call_base)
 739
 740 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 741 void bpf_jit_compile(struct bpf_prog *prog);
 742 bool bpf_helper_changes_pkt_data(void *func);
 743
 744 static inline bool bpf_dump_raw_ok(void)
 745 {
 746         /* Reconstruction of call-sites is dependent on kallsyms,
 747          * thus make dump the same restriction.
 748          */
 749         return kallsyms_show_value() == 1;
 750 }
 751
 752 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 753                                        const struct bpf_insn *patch, u32 len);
 754
 755 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
 756  * same cpu context. Further for best results no more than a single map
 757  * for the do_redirect/do_flush pair should be used. This limitation is
 758  * because we only track one map and force a flush when the map changes.
 759  * This does not appear to be a real limitation for existing software.
 760  */
 761 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 762                             struct bpf_prog *prog);
 763 int xdp_do_redirect(struct net_device *dev,
 764                     struct xdp_buff *xdp,
 765                     struct bpf_prog *prog);
 766 void xdp_do_flush_map(void);
 767
 768 void bpf_warn_invalid_xdp_action(u32 act);
 769
 770 struct sock *do_sk_redirect_map(struct sk_buff *skb);
 771 struct sock *do_msg_redirect_map(struct sk_msg_buff *md);
 772
 773 #ifdef CONFIG_BPF_JIT
 774 extern int bpf_jit_enable;
 775 extern int bpf_jit_harden;
 776 extern int bpf_jit_kallsyms;
 777
 778 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 779
 780 struct bpf_binary_header *
 781 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 782                      unsigned int alignment,
 783                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
 784 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 785
 786 void bpf_jit_free(struct bpf_prog *fp);
 787
 788 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 789 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 790
 791 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 792                                 u32 pass, void *image)
 793 {
 794         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 795                proglen, pass, image, current->comm, task_pid_nr(current));
 796
 797         if (image)
 798                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 799                                16, 1, image, proglen, false);
 800 }
 801
 802 static inline bool bpf_jit_is_ebpf(void)
 803 {
 804 # ifdef CONFIG_HAVE_EBPF_JIT
 805         return true;
 806 # else
 807         return false;
 808 # endif
 809 }
 810
 811 static inline bool ebpf_jit_enabled(void)
 812 {
 813         return bpf_jit_enable && bpf_jit_is_ebpf();
 814 }
 815
 816 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 817 {
 818         return fp->jited && bpf_jit_is_ebpf();
 819 }
 820
 821 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
 822 {
 823         /* These are the prerequisites, should someone ever have the
 824          * idea to call blinding outside of them, we make sure to
 825          * bail out.
 826          */
 827         if (!bpf_jit_is_ebpf())
 828                 return false;
 829         if (!prog->jit_requested)
 830                 return false;
 831         if (!bpf_jit_harden)
 832                 return false;
 833         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 834                 return false;
 835
 836         return true;
 837 }
 838
 839 static inline bool bpf_jit_kallsyms_enabled(void)
 840 {
 841         /* There are a couple of corner cases where kallsyms should
 842          * not be enabled f.e. on hardening.
 843          */
 844         if (bpf_jit_harden)
 845                 return false;
 846         if (!bpf_jit_kallsyms)
 847                 return false;
 848         if (bpf_jit_kallsyms == 1)
 849                 return true;
 850
 851         return false;
 852 }
 853
 854 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 855                                  unsigned long *off, char *sym);
 856 bool is_bpf_text_address(unsigned long addr);
 857 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 858                     char *sym);
 859
 860 static inline const char *
 861 bpf_address_lookup(unsigned long addr, unsigned long *size,
 862                    unsigned long *off, char **modname, char *sym)
 863 {
 864         const char *ret = __bpf_address_lookup(addr, size, off, sym);
 865
 866         if (ret && modname)
 867                 *modname = NULL;
 868         return ret;
 869 }
 870
 871 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 872 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
 873
 874 #else /* CONFIG_BPF_JIT */
 875
 876 static inline bool ebpf_jit_enabled(void)
 877 {
 878         return false;
 879 }
 880
 881 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 882 {
 883         return false;
 884 }
 885
 886 static inline void bpf_jit_free(struct bpf_prog *fp)
 887 {
 888         bpf_prog_unlock_free(fp);
 889 }
 890
 891 static inline bool bpf_jit_kallsyms_enabled(void)
 892 {
 893         return false;
 894 }
 895
 896 static inline const char *
 897 __bpf_address_lookup(unsigned long addr, unsigned long *size,
 898                      unsigned long *off, char *sym)
 899 {
 900         return NULL;
 901 }
 902
 903 static inline bool is_bpf_text_address(unsigned long addr)
 904 {
 905         return false;
 906 }
 907
 908 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
 909                                   char *type, char *sym)
 910 {
 911         return -ERANGE;
 912 }
 913
 914 static inline const char *
 915 bpf_address_lookup(unsigned long addr, unsigned long *size,
 916                    unsigned long *off, char **modname, char *sym)
 917 {
 918         return NULL;
 919 }
 920
 921 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 922 {
 923 }
 924
 925 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 926 {
 927 }
 928 #endif /* CONFIG_BPF_JIT */
 929
 930 #define BPF_ANC         BIT(15)
 931
 932 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
 933 {
 934         switch (first->code) {
 935         case BPF_RET | BPF_K:
 936         case BPF_LD | BPF_W | BPF_LEN:
 937                 return false;
 938
 939         case BPF_LD | BPF_W | BPF_ABS:
 940         case BPF_LD | BPF_H | BPF_ABS:
 941         case BPF_LD | BPF_B | BPF_ABS:
 942                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
 943                         return true;
 944                 return false;
 945
 946         default:
 947                 return true;
 948         }
 949 }
 950
 951 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 952 {
 953         BUG_ON(ftest->code & BPF_ANC);
 954
 955         switch (ftest->code) {
 956         case BPF_LD | BPF_W | BPF_ABS:
 957         case BPF_LD | BPF_H | BPF_ABS:
 958         case BPF_LD | BPF_B | BPF_ABS:
 959 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
 960                                 return BPF_ANC | SKF_AD_##CODE
 961                 switch (ftest->k) {
 962                 BPF_ANCILLARY(PROTOCOL);
 963                 BPF_ANCILLARY(PKTTYPE);
 964                 BPF_ANCILLARY(IFINDEX);
 965                 BPF_ANCILLARY(NLATTR);
 966                 BPF_ANCILLARY(NLATTR_NEST);
 967                 BPF_ANCILLARY(MARK);
 968                 BPF_ANCILLARY(QUEUE);
 969                 BPF_ANCILLARY(HATYPE);
 970                 BPF_ANCILLARY(RXHASH);
 971                 BPF_ANCILLARY(CPU);
 972                 BPF_ANCILLARY(ALU_XOR_X);
 973                 BPF_ANCILLARY(VLAN_TAG);
 974                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
 975                 BPF_ANCILLARY(PAY_OFFSET);
 976                 BPF_ANCILLARY(RANDOM);
 977                 BPF_ANCILLARY(VLAN_TPID);
 978                 }
 979                 /* Fallthrough. */
 980         default:
 981                 return ftest->code;
 982         }
 983 }
 984
 985 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 986                                            int k, unsigned int size);
 987
 988 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
 989                                      unsigned int size, void *buffer)
 990 {
 991         if (k >= 0)
 992                 return skb_header_pointer(skb, k, size, buffer);
 993
 994         return bpf_internal_load_pointer_neg_helper(skb, k, size);
 995 }
 996
 997 static inline int bpf_tell_extensions(void)
 998 {
 999         return SKF_AD_MAX;
1000 }
1001
1002 struct bpf_sock_addr_kern {
1003         struct sock *sk;
1004         struct sockaddr *uaddr;
1005         /* Temporary "register" to make indirect stores to nested structures
1006          * defined above. We need three registers to make such a store, but
1007          * only two (src and dst) are available at convert_ctx_access time
1008          */
1009         u64 tmp_reg;
1010 };
1011
1012 struct bpf_sock_ops_kern {
1013         struct  sock *sk;
1014         u32     op;
1015         union {
1016                 u32 args[4];
1017                 u32 reply;
1018                 u32 replylong[4];
1019         };
1020         u32     is_fullsock;
1021         u64     temp;                   /* temp and everything after is not
1022                                          * initialized to 0 before calling
1023                                          * the BPF program. New fields that
1024                                          * should be initialized to 0 should
1025                                          * be inserted before temp.
1026                                          * temp is scratch storage used by
1027                                          * sock_ops_convert_ctx_access
1028                                          * as temporary storage of a register.
1029                                          */
1030 };
1031
1032 #endif /* __LINUX_FILTER_H__ */