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