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