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 #include <linux/if_vlan.h>
  23 #include <linux/vmalloc.h>
  24
  25 #include <net/sch_generic.h>
  26
  27 #include <uapi/linux/filter.h>
  28 #include <uapi/linux/bpf.h>
  29
  30 struct sk_buff;
  31 struct sock;
  32 struct seccomp_data;
  33 struct bpf_prog_aux;
  34 struct xdp_rxq_info;
  35 struct xdp_buff;
  36 struct sock_reuseport;
  37 struct ctl_table;
  38 struct ctl_table_header;
  39
  40 /* ArgX, context and stack frame pointer register positions. Note,
  41  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  42  * calls in BPF_CALL instruction.
  43  */
  44 #define BPF_REG_ARG1    BPF_REG_1
  45 #define BPF_REG_ARG2    BPF_REG_2
  46 #define BPF_REG_ARG3    BPF_REG_3
  47 #define BPF_REG_ARG4    BPF_REG_4
  48 #define BPF_REG_ARG5    BPF_REG_5
  49 #define BPF_REG_CTX     BPF_REG_6
  50 #define BPF_REG_FP      BPF_REG_10
  51
  52 /* Additional register mappings for converted user programs. */
  53 #define BPF_REG_A       BPF_REG_0
  54 #define BPF_REG_X       BPF_REG_7
  55 #define BPF_REG_TMP     BPF_REG_2       /* scratch reg */
  56 #define BPF_REG_D       BPF_REG_8       /* data, callee-saved */
  57 #define BPF_REG_H       BPF_REG_9       /* hlen, callee-saved */
  58
  59 /* Kernel hidden auxiliary/helper register. */
  60 #define BPF_REG_AX              MAX_BPF_REG
  61 #define MAX_BPF_EXT_REG         (MAX_BPF_REG + 1)
  62 #define MAX_BPF_JIT_REG         MAX_BPF_EXT_REG
  63
  64 /* unused opcode to mark special call to bpf_tail_call() helper */
  65 #define BPF_TAIL_CALL   0xf0
  66
  67 /* unused opcode to mark call to interpreter with arguments */
  68 #define BPF_CALL_ARGS   0xe0
  69
  70 /* As per nm, we expose JITed images as text (code) section for
  71  * kallsyms. That way, tools like perf can find it to match
  72  * addresses.
  73  */
  74 #define BPF_SYM_ELF_TYPE        't'
  75
  76 /* BPF program can access up to 512 bytes of stack space. */
  77 #define MAX_BPF_STACK   512
  78
  79 /* Helper macros for filter block array initializers. */
  80
  81 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  82
  83 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  84         ((struct bpf_insn) {                                    \
  85                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  86                 .dst_reg = DST,                                 \
  87                 .src_reg = SRC,                                 \
  88                 .off   = 0,                                     \
  89                 .imm   = 0 })
  90
  91 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  92         ((struct bpf_insn) {                                    \
  93                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  94                 .dst_reg = DST,                                 \
  95                 .src_reg = SRC,                                 \
  96                 .off   = 0,                                     \
  97                 .imm   = 0 })
  98
  99 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
 100
 101 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
 102         ((struct bpf_insn) {                                    \
 103                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
 104                 .dst_reg = DST,                                 \
 105                 .src_reg = 0,                                   \
 106                 .off   = 0,                                     \
 107                 .imm   = IMM })
 108
 109 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
 110         ((struct bpf_insn) {                                    \
 111                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
 112                 .dst_reg = DST,                                 \
 113                 .src_reg = 0,                                   \
 114                 .off   = 0,                                     \
 115                 .imm   = IMM })
 116
 117 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
 118
 119 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
 120         ((struct bpf_insn) {                                    \
 121                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 122                 .dst_reg = DST,                                 \
 123                 .src_reg = 0,                                   \
 124                 .off   = 0,                                     \
 125                 .imm   = LEN })
 126
 127 /* Short form of mov, dst_reg = src_reg */
 128
 129 #define BPF_MOV64_REG(DST, SRC)                                 \
 130         ((struct bpf_insn) {                                    \
 131                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 132                 .dst_reg = DST,                                 \
 133                 .src_reg = SRC,                                 \
 134                 .off   = 0,                                     \
 135                 .imm   = 0 })
 136
 137 #define BPF_MOV32_REG(DST, SRC)                                 \
 138         ((struct bpf_insn) {                                    \
 139                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 140                 .dst_reg = DST,                                 \
 141                 .src_reg = SRC,                                 \
 142                 .off   = 0,                                     \
 143                 .imm   = 0 })
 144
 145 /* Short form of mov, dst_reg = imm32 */
 146
 147 #define BPF_MOV64_IMM(DST, IMM)                                 \
 148         ((struct bpf_insn) {                                    \
 149                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 150                 .dst_reg = DST,                                 \
 151                 .src_reg = 0,                                   \
 152                 .off   = 0,                                     \
 153                 .imm   = IMM })
 154
 155 #define BPF_MOV32_IMM(DST, IMM)                                 \
 156         ((struct bpf_insn) {                                    \
 157                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 158                 .dst_reg = DST,                                 \
 159                 .src_reg = 0,                                   \
 160                 .off   = 0,                                     \
 161                 .imm   = IMM })
 162
 163 /* Special form of mov32, used for doing explicit zero extension on dst. */
 164 #define BPF_ZEXT_REG(DST)                                       \
 165         ((struct bpf_insn) {                                    \
 166                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 167                 .dst_reg = DST,                                 \
 168                 .src_reg = DST,                                 \
 169                 .off   = 0,                                     \
 170                 .imm   = 1 })
 171
 172 static inline bool insn_is_zext(const struct bpf_insn *insn)
 173 {
 174         return insn->code == (BPF_ALU | BPF_MOV | BPF_X) && insn->imm == 1;
 175 }
 176
 177 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 178 #define BPF_LD_IMM64(DST, IMM)                                  \
 179         BPF_LD_IMM64_RAW(DST, 0, IMM)
 180
 181 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 182         ((struct bpf_insn) {                                    \
 183                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 184                 .dst_reg = DST,                                 \
 185                 .src_reg = SRC,                                 \
 186                 .off   = 0,                                     \
 187                 .imm   = (__u32) (IMM) }),                      \
 188         ((struct bpf_insn) {                                    \
 189                 .code  = 0, /* zero is reserved opcode */       \
 190                 .dst_reg = 0,                                   \
 191                 .src_reg = 0,                                   \
 192                 .off   = 0,                                     \
 193                 .imm   = ((__u64) (IMM)) >> 32 })
 194
 195 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 196 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 197         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 198
 199 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 200
 201 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 202         ((struct bpf_insn) {                                    \
 203                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 204                 .dst_reg = DST,                                 \
 205                 .src_reg = SRC,                                 \
 206                 .off   = 0,                                     \
 207                 .imm   = IMM })
 208
 209 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 210         ((struct bpf_insn) {                                    \
 211                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 212                 .dst_reg = DST,                                 \
 213                 .src_reg = SRC,                                 \
 214                 .off   = 0,                                     \
 215                 .imm   = IMM })
 216
 217 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 218
 219 #define BPF_LD_ABS(SIZE, IMM)                                   \
 220         ((struct bpf_insn) {                                    \
 221                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 222                 .dst_reg = 0,                                   \
 223                 .src_reg = 0,                                   \
 224                 .off   = 0,                                     \
 225                 .imm   = IMM })
 226
 227 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 228
 229 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 230         ((struct bpf_insn) {                                    \
 231                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 232                 .dst_reg = 0,                                   \
 233                 .src_reg = SRC,                                 \
 234                 .off   = 0,                                     \
 235                 .imm   = IMM })
 236
 237 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 238
 239 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 240         ((struct bpf_insn) {                                    \
 241                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 242                 .dst_reg = DST,                                 \
 243                 .src_reg = SRC,                                 \
 244                 .off   = OFF,                                   \
 245                 .imm   = 0 })
 246
 247 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 248
 249 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 250         ((struct bpf_insn) {                                    \
 251                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 252                 .dst_reg = DST,                                 \
 253                 .src_reg = SRC,                                 \
 254                 .off   = OFF,                                   \
 255                 .imm   = 0 })
 256
 257 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 258
 259 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 260         ((struct bpf_insn) {                                    \
 261                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 262                 .dst_reg = DST,                                 \
 263                 .src_reg = SRC,                                 \
 264                 .off   = OFF,                                   \
 265                 .imm   = 0 })
 266
 267 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 268
 269 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 270         ((struct bpf_insn) {                                    \
 271                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 272                 .dst_reg = DST,                                 \
 273                 .src_reg = 0,                                   \
 274                 .off   = OFF,                                   \
 275                 .imm   = IMM })
 276
 277 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 278
 279 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 280         ((struct bpf_insn) {                                    \
 281                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 282                 .dst_reg = DST,                                 \
 283                 .src_reg = SRC,                                 \
 284                 .off   = OFF,                                   \
 285                 .imm   = 0 })
 286
 287 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 288
 289 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 290         ((struct bpf_insn) {                                    \
 291                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 292                 .dst_reg = DST,                                 \
 293                 .src_reg = 0,                                   \
 294                 .off   = OFF,                                   \
 295                 .imm   = IMM })
 296
 297 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
 298
 299 #define BPF_JMP32_REG(OP, DST, SRC, OFF)                        \
 300         ((struct bpf_insn) {                                    \
 301                 .code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,        \
 302                 .dst_reg = DST,                                 \
 303                 .src_reg = SRC,                                 \
 304                 .off   = OFF,                                   \
 305                 .imm   = 0 })
 306
 307 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
 308
 309 #define BPF_JMP32_IMM(OP, DST, IMM, OFF)                        \
 310         ((struct bpf_insn) {                                    \
 311                 .code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,        \
 312                 .dst_reg = DST,                                 \
 313                 .src_reg = 0,                                   \
 314                 .off   = OFF,                                   \
 315                 .imm   = IMM })
 316
 317 /* Unconditional jumps, goto pc + off16 */
 318
 319 #define BPF_JMP_A(OFF)                                          \
 320         ((struct bpf_insn) {                                    \
 321                 .code  = BPF_JMP | BPF_JA,                      \
 322                 .dst_reg = 0,                                   \
 323                 .src_reg = 0,                                   \
 324                 .off   = OFF,                                   \
 325                 .imm   = 0 })
 326
 327 /* Relative call */
 328
 329 #define BPF_CALL_REL(TGT)                                       \
 330         ((struct bpf_insn) {                                    \
 331                 .code  = BPF_JMP | BPF_CALL,                    \
 332                 .dst_reg = 0,                                   \
 333                 .src_reg = BPF_PSEUDO_CALL,                     \
 334                 .off   = 0,                                     \
 335                 .imm   = TGT })
 336
 337 /* Function call */
 338
 339 #define BPF_CAST_CALL(x)                                        \
 340                 ((u64 (*)(u64, u64, u64, u64, u64))(x))
 341
 342 #define BPF_EMIT_CALL(FUNC)                                     \
 343         ((struct bpf_insn) {                                    \
 344                 .code  = BPF_JMP | BPF_CALL,                    \
 345                 .dst_reg = 0,                                   \
 346                 .src_reg = 0,                                   \
 347                 .off   = 0,                                     \
 348                 .imm   = ((FUNC) - __bpf_call_base) })
 349
 350 /* Raw code statement block */
 351
 352 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 353         ((struct bpf_insn) {                                    \
 354                 .code  = CODE,                                  \
 355                 .dst_reg = DST,                                 \
 356                 .src_reg = SRC,                                 \
 357                 .off   = OFF,                                   \
 358                 .imm   = IMM })
 359
 360 /* Program exit */
 361
 362 #define BPF_EXIT_INSN()                                         \
 363         ((struct bpf_insn) {                                    \
 364                 .code  = BPF_JMP | BPF_EXIT,                    \
 365                 .dst_reg = 0,                                   \
 366                 .src_reg = 0,                                   \
 367                 .off   = 0,                                     \
 368                 .imm   = 0 })
 369
 370 /* Internal classic blocks for direct assignment */
 371
 372 #define __BPF_STMT(CODE, K)                                     \
 373         ((struct sock_filter) BPF_STMT(CODE, K))
 374
 375 #define __BPF_JUMP(CODE, K, JT, JF)                             \
 376         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 377
 378 #define bytes_to_bpf_size(bytes)                                \
 379 ({                                                              \
 380         int bpf_size = -EINVAL;                                 \
 381                                                                 \
 382         if (bytes == sizeof(u8))                                \
 383                 bpf_size = BPF_B;                               \
 384         else if (bytes == sizeof(u16))                          \
 385                 bpf_size = BPF_H;                               \
 386         else if (bytes == sizeof(u32))                          \
 387                 bpf_size = BPF_W;                               \
 388         else if (bytes == sizeof(u64))                          \
 389                 bpf_size = BPF_DW;                              \
 390                                                                 \
 391         bpf_size;                                               \
 392 })
 393
 394 #define bpf_size_to_bytes(bpf_size)                             \
 395 ({                                                              \
 396         int bytes = -EINVAL;                                    \
 397                                                                 \
 398         if (bpf_size == BPF_B)                                  \
 399                 bytes = sizeof(u8);                             \
 400         else if (bpf_size == BPF_H)                             \
 401                 bytes = sizeof(u16);                            \
 402         else if (bpf_size == BPF_W)                             \
 403                 bytes = sizeof(u32);                            \
 404         else if (bpf_size == BPF_DW)                            \
 405                 bytes = sizeof(u64);                            \
 406                                                                 \
 407         bytes;                                                  \
 408 })
 409
 410 #define BPF_SIZEOF(type)                                        \
 411         ({                                                      \
 412                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 413                 BUILD_BUG_ON(__size < 0);                       \
 414                 __size;                                         \
 415         })
 416
 417 #define BPF_FIELD_SIZEOF(type, field)                           \
 418         ({                                                      \
 419                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 420                 BUILD_BUG_ON(__size < 0);                       \
 421                 __size;                                         \
 422         })
 423
 424 #define BPF_LDST_BYTES(insn)                                    \
 425         ({                                                      \
 426                 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
 427                 WARN_ON(__size < 0);                            \
 428                 __size;                                         \
 429         })
 430
 431 #define __BPF_MAP_0(m, v, ...) v
 432 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 433 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 434 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 435 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 436 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 437
 438 #define __BPF_REG_0(...) __BPF_PAD(5)
 439 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 440 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 441 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 442 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 443 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 444
 445 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 446 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 447
 448 #define __BPF_CAST(t, a)                                                       \
 449         (__force t)                                                            \
 450         (__force                                                               \
 451          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 452                                       (unsigned long)0, (t)0))) a
 453 #define __BPF_V void
 454 #define __BPF_N
 455
 456 #define __BPF_DECL_ARGS(t, a) t   a
 457 #define __BPF_DECL_REGS(t, a) u64 a
 458
 459 #define __BPF_PAD(n)                                                           \
 460         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 461                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 462
 463 #define BPF_CALL_x(x, name, ...)                                               \
 464         static __always_inline                                                 \
 465         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 466         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 467         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 468         {                                                                      \
 469                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 470         }                                                                      \
 471         static __always_inline                                                 \
 472         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 473
 474 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 475 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 476 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 477 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 478 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 479 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 480
 481 #define bpf_ctx_range(TYPE, MEMBER)                                             \
 482         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 483 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)                              \
 484         offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
 485 #if BITS_PER_LONG == 64
 486 # define bpf_ctx_range_ptr(TYPE, MEMBER)                                        \
 487         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 488 #else
 489 # define bpf_ctx_range_ptr(TYPE, MEMBER)                                        \
 490         offsetof(TYPE, MEMBER) ... offsetof(TYPE, MEMBER) + 8 - 1
 491 #endif /* BITS_PER_LONG == 64 */
 492
 493 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)                            \
 494         ({                                                                      \
 495                 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE));             \
 496                 *(PTR_SIZE) = (SIZE);                                           \
 497                 offsetof(TYPE, MEMBER);                                         \
 498         })
 499
 500 #ifdef CONFIG_COMPAT
 501 /* A struct sock_filter is architecture independent. */
 502 struct compat_sock_fprog {
 503         u16             len;
 504         compat_uptr_t   filter; /* struct sock_filter * */
 505 };
 506 #endif
 507
 508 struct sock_fprog_kern {
 509         u16                     len;
 510         struct sock_filter      *filter;
 511 };
 512
 513 struct bpf_binary_header {
 514         u32 pages;
 515         /* Some arches need word alignment for their instructions */
 516         u8 image[] __aligned(4);
 517 };
 518
 519 struct bpf_prog {
 520         u16                     pages;          /* Number of allocated pages */
 521         u16                     jited:1,        /* Is our filter JIT'ed? */
 522                                 jit_requested:1,/* archs need to JIT the prog */
 523                                 gpl_compatible:1, /* Is filter GPL compatible? */
 524                                 cb_access:1,    /* Is control block accessed? */
 525                                 dst_needed:1,   /* Do we need dst entry? */
 526                                 blinded:1,      /* Was blinded */
 527                                 is_func:1,      /* program is a bpf function */
 528                                 kprobe_override:1, /* Do we override a kprobe? */
 529                                 has_callchain_buf:1, /* callchain buffer allocated? */
 530                                 enforce_expected_attach_type:1; /* Enforce expected_attach_type checking at attach time */
 531         enum bpf_prog_type      type;           /* Type of BPF program */
 532         enum bpf_attach_type    expected_attach_type; /* For some prog types */
 533         u32                     len;            /* Number of filter blocks */
 534         u32                     jited_len;      /* Size of jited insns in bytes */
 535         u8                      tag[BPF_TAG_SIZE];
 536         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 537         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 538         unsigned int            (*bpf_func)(const void *ctx,
 539                                             const struct bpf_insn *insn);
 540         /* Instructions for interpreter */
 541         union {
 542                 struct sock_filter      insns[0];
 543                 struct bpf_insn         insnsi[0];
 544         };
 545 };
 546
 547 struct sk_filter {
 548         refcount_t      refcnt;
 549         struct rcu_head rcu;
 550         struct bpf_prog *prog;
 551 };
 552
 553 DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 554
 555 #define BPF_PROG_RUN(prog, ctx) ({                              \
 556         u32 ret;                                                \
 557         cant_sleep();                                           \
 558         if (static_branch_unlikely(&bpf_stats_enabled_key)) {   \
 559                 struct bpf_prog_stats *stats;                   \
 560                 u64 start = sched_clock();                      \
 561                 ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi); \
 562                 stats = this_cpu_ptr(prog->aux->stats);         \
 563                 u64_stats_update_begin(&stats->syncp);          \
 564                 stats->cnt++;                                   \
 565                 stats->nsecs += sched_clock() - start;          \
 566                 u64_stats_update_end(&stats->syncp);            \
 567         } else {                                                \
 568                 ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi); \
 569         }                                                       \
 570         ret; })
 571
 572 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 573
 574 struct bpf_skb_data_end {
 575         struct qdisc_skb_cb qdisc_cb;
 576         void *data_meta;
 577         void *data_end;
 578 };
 579
 580 struct bpf_redirect_info {
 581         u32 flags;
 582         u32 tgt_index;
 583         void *tgt_value;
 584         struct bpf_map *map;
 585         struct bpf_map *map_to_flush;
 586         u32 kern_flags;
 587 };
 588
 589 DECLARE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info);
 590
 591 /* flags for bpf_redirect_info kern_flags */
 592 #define BPF_RI_F_RF_NO_DIRECT   BIT(0)  /* no napi_direct on return_frame */
 593
 594 /* Compute the linear packet data range [data, data_end) which
 595  * will be accessed by various program types (cls_bpf, act_bpf,
 596  * lwt, ...). Subsystems allowing direct data access must (!)
 597  * ensure that cb[] area can be written to when BPF program is
 598  * invoked (otherwise cb[] save/restore is necessary).
 599  */
 600 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
 601 {
 602         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 603
 604         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 605         cb->data_meta = skb->data - skb_metadata_len(skb);
 606         cb->data_end  = skb->data + skb_headlen(skb);
 607 }
 608
 609 /* Similar to bpf_compute_data_pointers(), except that save orginal
 610  * data in cb->data and cb->meta_data for restore.
 611  */
 612 static inline void bpf_compute_and_save_data_end(
 613         struct sk_buff *skb, void **saved_data_end)
 614 {
 615         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 616
 617         *saved_data_end = cb->data_end;
 618         cb->data_end  = skb->data + skb_headlen(skb);
 619 }
 620
 621 /* Restore data saved by bpf_compute_data_pointers(). */
 622 static inline void bpf_restore_data_end(
 623         struct sk_buff *skb, void *saved_data_end)
 624 {
 625         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 626
 627         cb->data_end = saved_data_end;
 628 }
 629
 630 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 631 {
 632         /* eBPF programs may read/write skb->cb[] area to transfer meta
 633          * data between tail calls. Since this also needs to work with
 634          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 635          *
 636          * In some socket filter cases, the cb unfortunately needs to be
 637          * saved/restored so that protocol specific skb->cb[] data won't
 638          * be lost. In any case, due to unpriviledged eBPF programs
 639          * attached to sockets, we need to clear the bpf_skb_cb() area
 640          * to not leak previous contents to user space.
 641          */
 642         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 643         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 644                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
 645
 646         return qdisc_skb_cb(skb)->data;
 647 }
 648
 649 static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
 650                                          struct sk_buff *skb)
 651 {
 652         u8 *cb_data = bpf_skb_cb(skb);
 653         u8 cb_saved[BPF_SKB_CB_LEN];
 654         u32 res;
 655
 656         if (unlikely(prog->cb_access)) {
 657                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 658                 memset(cb_data, 0, sizeof(cb_saved));
 659         }
 660
 661         res = BPF_PROG_RUN(prog, skb);
 662
 663         if (unlikely(prog->cb_access))
 664                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 665
 666         return res;
 667 }
 668
 669 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 670                                        struct sk_buff *skb)
 671 {
 672         u32 res;
 673
 674         preempt_disable();
 675         res = __bpf_prog_run_save_cb(prog, skb);
 676         preempt_enable();
 677         return res;
 678 }
 679
 680 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 681                                         struct sk_buff *skb)
 682 {
 683         u8 *cb_data = bpf_skb_cb(skb);
 684         u32 res;
 685
 686         if (unlikely(prog->cb_access))
 687                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 688
 689         preempt_disable();
 690         res = BPF_PROG_RUN(prog, skb);
 691         preempt_enable();
 692         return res;
 693 }
 694
 695 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 696                                             struct xdp_buff *xdp)
 697 {
 698         /* Caller needs to hold rcu_read_lock() (!), otherwise program
 699          * can be released while still running, or map elements could be
 700          * freed early while still having concurrent users. XDP fastpath
 701          * already takes rcu_read_lock() when fetching the program, so
 702          * it's not necessary here anymore.
 703          */
 704         return BPF_PROG_RUN(prog, xdp);
 705 }
 706
 707 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 708 {
 709         return prog->len * sizeof(struct bpf_insn);
 710 }
 711
 712 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 713 {
 714         return round_up(bpf_prog_insn_size(prog) +
 715                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 716 }
 717
 718 static inline unsigned int bpf_prog_size(unsigned int proglen)
 719 {
 720         return max(sizeof(struct bpf_prog),
 721                    offsetof(struct bpf_prog, insns[proglen]));
 722 }
 723
 724 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 725 {
 726         /* When classic BPF programs have been loaded and the arch
 727          * does not have a classic BPF JIT (anymore), they have been
 728          * converted via bpf_migrate_filter() to eBPF and thus always
 729          * have an unspec program type.
 730          */
 731         return prog->type == BPF_PROG_TYPE_UNSPEC;
 732 }
 733
 734 static inline u32 bpf_ctx_off_adjust_machine(u32 size)
 735 {
 736         const u32 size_machine = sizeof(unsigned long);
 737
 738         if (size > size_machine && size % size_machine == 0)
 739                 size = size_machine;
 740
 741         return size;
 742 }
 743
 744 static inline bool
 745 bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
 746 {
 747         return size <= size_default && (size & (size - 1)) == 0;
 748 }
 749
 750 #define bpf_ctx_wide_access_ok(off, size, type, field)                  \
 751         (size == sizeof(__u64) &&                                       \
 752         off >= offsetof(type, field) &&                                 \
 753         off + sizeof(__u64) <= offsetofend(type, field) &&              \
 754         off % sizeof(__u64) == 0)
 755
 756 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 757
 758 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 759 {
 760         set_vm_flush_reset_perms(fp);
 761         set_memory_ro((unsigned long)fp, fp->pages);
 762 }
 763
 764 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 765 {
 766         set_vm_flush_reset_perms(hdr);
 767         set_memory_ro((unsigned long)hdr, hdr->pages);
 768         set_memory_x((unsigned long)hdr, hdr->pages);
 769 }
 770
 771 static inline struct bpf_binary_header *
 772 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 773 {
 774         unsigned long real_start = (unsigned long)fp->bpf_func;
 775         unsigned long addr = real_start & PAGE_MASK;
 776
 777         return (void *)addr;
 778 }
 779
 780 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 781 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 782 {
 783         return sk_filter_trim_cap(sk, skb, 1);
 784 }
 785
 786 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 787 void bpf_prog_free(struct bpf_prog *fp);
 788
 789 bool bpf_opcode_in_insntable(u8 code);
 790
 791 void bpf_prog_free_linfo(struct bpf_prog *prog);
 792 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 793                                const u32 *insn_to_jit_off);
 794 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);
 795 void bpf_prog_free_jited_linfo(struct bpf_prog *prog);
 796 void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog);
 797
 798 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 799 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags);
 800 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 801                                   gfp_t gfp_extra_flags);
 802 void __bpf_prog_free(struct bpf_prog *fp);
 803
 804 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 805 {
 806         __bpf_prog_free(fp);
 807 }
 808
 809 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 810                                        unsigned int flen);
 811
 812 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 813 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 814                               bpf_aux_classic_check_t trans, bool save_orig);
 815 void bpf_prog_destroy(struct bpf_prog *fp);
 816
 817 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 818 int sk_attach_bpf(u32 ufd, struct sock *sk);
 819 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 820 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 821 void sk_reuseport_prog_free(struct bpf_prog *prog);
 822 int sk_detach_filter(struct sock *sk);
 823 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 824                   unsigned int len);
 825
 826 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 827 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 828
 829 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 830 #define __bpf_call_base_args \
 831         ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
 832          __bpf_call_base)
 833
 834 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 835 void bpf_jit_compile(struct bpf_prog *prog);
 836 bool bpf_jit_needs_zext(void);
 837 bool bpf_helper_changes_pkt_data(void *func);
 838
 839 static inline bool bpf_dump_raw_ok(void)
 840 {
 841         /* Reconstruction of call-sites is dependent on kallsyms,
 842          * thus make dump the same restriction.
 843          */
 844         return kallsyms_show_value() == 1;
 845 }
 846
 847 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 848                                        const struct bpf_insn *patch, u32 len);
 849 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt);
 850
 851 void bpf_clear_redirect_map(struct bpf_map *map);
 852
 853 static inline bool xdp_return_frame_no_direct(void)
 854 {
 855         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 856
 857         return ri->kern_flags & BPF_RI_F_RF_NO_DIRECT;
 858 }
 859
 860 static inline void xdp_set_return_frame_no_direct(void)
 861 {
 862         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 863
 864         ri->kern_flags |= BPF_RI_F_RF_NO_DIRECT;
 865 }
 866
 867 static inline void xdp_clear_return_frame_no_direct(void)
 868 {
 869         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 870
 871         ri->kern_flags &= ~BPF_RI_F_RF_NO_DIRECT;
 872 }
 873
 874 static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
 875                                  unsigned int pktlen)
 876 {
 877         unsigned int len;
 878
 879         if (unlikely(!(fwd->flags & IFF_UP)))
 880                 return -ENETDOWN;
 881
 882         len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN;
 883         if (pktlen > len)
 884                 return -EMSGSIZE;
 885
 886         return 0;
 887 }
 888
 889 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
 890  * same cpu context. Further for best results no more than a single map
 891  * for the do_redirect/do_flush pair should be used. This limitation is
 892  * because we only track one map and force a flush when the map changes.
 893  * This does not appear to be a real limitation for existing software.
 894  */
 895 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 896                             struct xdp_buff *xdp, struct bpf_prog *prog);
 897 int xdp_do_redirect(struct net_device *dev,
 898                     struct xdp_buff *xdp,
 899                     struct bpf_prog *prog);
 900 void xdp_do_flush_map(void);
 901
 902 void bpf_warn_invalid_xdp_action(u32 act);
 903
 904 #ifdef CONFIG_INET
 905 struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
 906                                   struct bpf_prog *prog, struct sk_buff *skb,
 907                                   u32 hash);
 908 #else
 909 static inline struct sock *
 910 bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
 911                      struct bpf_prog *prog, struct sk_buff *skb,
 912                      u32 hash)
 913 {
 914         return NULL;
 915 }
 916 #endif
 917
 918 #ifdef CONFIG_BPF_JIT
 919 extern int bpf_jit_enable;
 920 extern int bpf_jit_harden;
 921 extern int bpf_jit_kallsyms;
 922 extern long bpf_jit_limit;
 923
 924 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 925
 926 struct bpf_binary_header *
 927 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 928                      unsigned int alignment,
 929                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
 930 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 931 u64 bpf_jit_alloc_exec_limit(void);
 932 void *bpf_jit_alloc_exec(unsigned long size);
 933 void bpf_jit_free_exec(void *addr);
 934 void bpf_jit_free(struct bpf_prog *fp);
 935
 936 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
 937                           const struct bpf_insn *insn, bool extra_pass,
 938                           u64 *func_addr, bool *func_addr_fixed);
 939
 940 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 941 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 942
 943 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 944                                 u32 pass, void *image)
 945 {
 946         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 947                proglen, pass, image, current->comm, task_pid_nr(current));
 948
 949         if (image)
 950                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 951                                16, 1, image, proglen, false);
 952 }
 953
 954 static inline bool bpf_jit_is_ebpf(void)
 955 {
 956 # ifdef CONFIG_HAVE_EBPF_JIT
 957         return true;
 958 # else
 959         return false;
 960 # endif
 961 }
 962
 963 static inline bool ebpf_jit_enabled(void)
 964 {
 965         return bpf_jit_enable && bpf_jit_is_ebpf();
 966 }
 967
 968 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 969 {
 970         return fp->jited && bpf_jit_is_ebpf();
 971 }
 972
 973 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
 974 {
 975         /* These are the prerequisites, should someone ever have the
 976          * idea to call blinding outside of them, we make sure to
 977          * bail out.
 978          */
 979         if (!bpf_jit_is_ebpf())
 980                 return false;
 981         if (!prog->jit_requested)
 982                 return false;
 983         if (!bpf_jit_harden)
 984                 return false;
 985         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 986                 return false;
 987
 988         return true;
 989 }
 990
 991 static inline bool bpf_jit_kallsyms_enabled(void)
 992 {
 993         /* There are a couple of corner cases where kallsyms should
 994          * not be enabled f.e. on hardening.
 995          */
 996         if (bpf_jit_harden)
 997                 return false;
 998         if (!bpf_jit_kallsyms)
 999                 return false;
1000         if (bpf_jit_kallsyms == 1)
1001                 return true;
1002
1003         return false;
1004 }
1005
1006 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
1007                                  unsigned long *off, char *sym);
1008 bool is_bpf_text_address(unsigned long addr);
1009 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
1010                     char *sym);
1011
1012 static inline const char *
1013 bpf_address_lookup(unsigned long addr, unsigned long *size,
1014                    unsigned long *off, char **modname, char *sym)
1015 {
1016         const char *ret = __bpf_address_lookup(addr, size, off, sym);
1017
1018         if (ret && modname)
1019                 *modname = NULL;
1020         return ret;
1021 }
1022
1023 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
1024 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
1025 void bpf_get_prog_name(const struct bpf_prog *prog, char *sym);
1026
1027 #else /* CONFIG_BPF_JIT */
1028
1029 static inline bool ebpf_jit_enabled(void)
1030 {
1031         return false;
1032 }
1033
1034 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
1035 {
1036         return false;
1037 }
1038
1039 static inline void bpf_jit_free(struct bpf_prog *fp)
1040 {
1041         bpf_prog_unlock_free(fp);
1042 }
1043
1044 static inline bool bpf_jit_kallsyms_enabled(void)
1045 {
1046         return false;
1047 }
1048
1049 static inline const char *
1050 __bpf_address_lookup(unsigned long addr, unsigned long *size,
1051                      unsigned long *off, char *sym)
1052 {
1053         return NULL;
1054 }
1055
1056 static inline bool is_bpf_text_address(unsigned long addr)
1057 {
1058         return false;
1059 }
1060
1061 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
1062                                   char *type, char *sym)
1063 {
1064         return -ERANGE;
1065 }
1066
1067 static inline const char *
1068 bpf_address_lookup(unsigned long addr, unsigned long *size,
1069                    unsigned long *off, char **modname, char *sym)
1070 {
1071         return NULL;
1072 }
1073
1074 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
1075 {
1076 }
1077
1078 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
1079 {
1080 }
1081
1082 static inline void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
1083 {
1084         sym[0] = '\0';
1085 }
1086
1087 #endif /* CONFIG_BPF_JIT */
1088
1089 void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp);
1090 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
1091
1092 #define BPF_ANC         BIT(15)
1093
1094 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
1095 {
1096         switch (first->code) {
1097         case BPF_RET | BPF_K:
1098         case BPF_LD | BPF_W | BPF_LEN:
1099                 return false;
1100
1101         case BPF_LD | BPF_W | BPF_ABS:
1102         case BPF_LD | BPF_H | BPF_ABS:
1103         case BPF_LD | BPF_B | BPF_ABS:
1104                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
1105                         return true;
1106                 return false;
1107
1108         default:
1109                 return true;
1110         }
1111 }
1112
1113 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
1114 {
1115         BUG_ON(ftest->code & BPF_ANC);
1116
1117         switch (ftest->code) {
1118         case BPF_LD | BPF_W | BPF_ABS:
1119         case BPF_LD | BPF_H | BPF_ABS:
1120         case BPF_LD | BPF_B | BPF_ABS:
1121 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
1122                                 return BPF_ANC | SKF_AD_##CODE
1123                 switch (ftest->k) {
1124                 BPF_ANCILLARY(PROTOCOL);
1125                 BPF_ANCILLARY(PKTTYPE);
1126                 BPF_ANCILLARY(IFINDEX);
1127                 BPF_ANCILLARY(NLATTR);
1128                 BPF_ANCILLARY(NLATTR_NEST);
1129                 BPF_ANCILLARY(MARK);
1130                 BPF_ANCILLARY(QUEUE);
1131                 BPF_ANCILLARY(HATYPE);
1132                 BPF_ANCILLARY(RXHASH);
1133                 BPF_ANCILLARY(CPU);
1134                 BPF_ANCILLARY(ALU_XOR_X);
1135                 BPF_ANCILLARY(VLAN_TAG);
1136                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
1137                 BPF_ANCILLARY(PAY_OFFSET);
1138                 BPF_ANCILLARY(RANDOM);
1139                 BPF_ANCILLARY(VLAN_TPID);
1140                 }
1141                 /* Fallthrough. */
1142         default:
1143                 return ftest->code;
1144         }
1145 }
1146
1147 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
1148                                            int k, unsigned int size);
1149
1150 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
1151                                      unsigned int size, void *buffer)
1152 {
1153         if (k >= 0)
1154                 return skb_header_pointer(skb, k, size, buffer);
1155
1156         return bpf_internal_load_pointer_neg_helper(skb, k, size);
1157 }
1158
1159 static inline int bpf_tell_extensions(void)
1160 {
1161         return SKF_AD_MAX;
1162 }
1163
1164 struct bpf_sock_addr_kern {
1165         struct sock *sk;
1166         struct sockaddr *uaddr;
1167         /* Temporary "register" to make indirect stores to nested structures
1168          * defined above. We need three registers to make such a store, but
1169          * only two (src and dst) are available at convert_ctx_access time
1170          */
1171         u64 tmp_reg;
1172         void *t_ctx;    /* Attach type specific context. */
1173 };
1174
1175 struct bpf_sock_ops_kern {
1176         struct  sock *sk;
1177         u32     op;
1178         union {
1179                 u32 args[4];
1180                 u32 reply;
1181                 u32 replylong[4];
1182         };
1183         u32     is_fullsock;
1184         u64     temp;                   /* temp and everything after is not
1185                                          * initialized to 0 before calling
1186                                          * the BPF program. New fields that
1187                                          * should be initialized to 0 should
1188                                          * be inserted before temp.
1189                                          * temp is scratch storage used by
1190                                          * sock_ops_convert_ctx_access
1191                                          * as temporary storage of a register.
1192                                          */
1193 };
1194
1195 struct bpf_sysctl_kern {
1196         struct ctl_table_header *head;
1197         struct ctl_table *table;
1198         void *cur_val;
1199         size_t cur_len;
1200         void *new_val;
1201         size_t new_len;
1202         int new_updated;
1203         int write;
1204         loff_t *ppos;
1205         /* Temporary "register" for indirect stores to ppos. */
1206         u64 tmp_reg;
1207 };
1208
1209 struct bpf_sockopt_kern {
1210         struct sock     *sk;
1211         u8              *optval;
1212         u8              *optval_end;
1213         s32             level;
1214         s32             optname;
1215         s32             optlen;
1216         s32             retval;
1217 };
1218
1219 #endif /* __LINUX_FILTER_H__ */