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/set_memory.h>
  20 #include <linux/kallsyms.h>
  21 #include <linux/if_vlan.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/sockptr.h>
  24 #include <crypto/sha1.h>
  25 #include <linux/u64_stats_sync.h>
  26
  27 #include <net/sch_generic.h>
  28
  29 #include <asm/byteorder.h>
  30 #include <uapi/linux/filter.h>
  31 #include <uapi/linux/bpf.h>
  32
  33 struct sk_buff;
  34 struct sock;
  35 struct seccomp_data;
  36 struct bpf_prog_aux;
  37 struct xdp_rxq_info;
  38 struct xdp_buff;
  39 struct sock_reuseport;
  40 struct ctl_table;
  41 struct ctl_table_header;
  42
  43 /* ArgX, context and stack frame pointer register positions. Note,
  44  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  45  * calls in BPF_CALL instruction.
  46  */
  47 #define BPF_REG_ARG1    BPF_REG_1
  48 #define BPF_REG_ARG2    BPF_REG_2
  49 #define BPF_REG_ARG3    BPF_REG_3
  50 #define BPF_REG_ARG4    BPF_REG_4
  51 #define BPF_REG_ARG5    BPF_REG_5
  52 #define BPF_REG_CTX     BPF_REG_6
  53 #define BPF_REG_FP      BPF_REG_10
  54
  55 /* Additional register mappings for converted user programs. */
  56 #define BPF_REG_A       BPF_REG_0
  57 #define BPF_REG_X       BPF_REG_7
  58 #define BPF_REG_TMP     BPF_REG_2       /* scratch reg */
  59 #define BPF_REG_D       BPF_REG_8       /* data, callee-saved */
  60 #define BPF_REG_H       BPF_REG_9       /* hlen, callee-saved */
  61
  62 /* Kernel hidden auxiliary/helper register. */
  63 #define BPF_REG_AX              MAX_BPF_REG
  64 #define MAX_BPF_EXT_REG         (MAX_BPF_REG + 1)
  65 #define MAX_BPF_JIT_REG         MAX_BPF_EXT_REG
  66
  67 /* unused opcode to mark special call to bpf_tail_call() helper */
  68 #define BPF_TAIL_CALL   0xf0
  69
  70 /* unused opcode to mark special load instruction. Same as BPF_ABS */
  71 #define BPF_PROBE_MEM   0x20
  72
  73 /* unused opcode to mark call to interpreter with arguments */
  74 #define BPF_CALL_ARGS   0xe0
  75
  76 /* As per nm, we expose JITed images as text (code) section for
  77  * kallsyms. That way, tools like perf can find it to match
  78  * addresses.
  79  */
  80 #define BPF_SYM_ELF_TYPE        't'
  81
  82 /* BPF program can access up to 512 bytes of stack space. */
  83 #define MAX_BPF_STACK   512
  84
  85 /* Helper macros for filter block array initializers. */
  86
  87 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  88
  89 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  90         ((struct bpf_insn) {                                    \
  91                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  92                 .dst_reg = DST,                                 \
  93                 .src_reg = SRC,                                 \
  94                 .off   = 0,                                     \
  95                 .imm   = 0 })
  96
  97 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  98         ((struct bpf_insn) {                                    \
  99                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
 100                 .dst_reg = DST,                                 \
 101                 .src_reg = SRC,                                 \
 102                 .off   = 0,                                     \
 103                 .imm   = 0 })
 104
 105 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
 106
 107 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
 108         ((struct bpf_insn) {                                    \
 109                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
 110                 .dst_reg = DST,                                 \
 111                 .src_reg = 0,                                   \
 112                 .off   = 0,                                     \
 113                 .imm   = IMM })
 114
 115 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
 116         ((struct bpf_insn) {                                    \
 117                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
 118                 .dst_reg = DST,                                 \
 119                 .src_reg = 0,                                   \
 120                 .off   = 0,                                     \
 121                 .imm   = IMM })
 122
 123 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
 124
 125 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
 126         ((struct bpf_insn) {                                    \
 127                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 128                 .dst_reg = DST,                                 \
 129                 .src_reg = 0,                                   \
 130                 .off   = 0,                                     \
 131                 .imm   = LEN })
 132
 133 /* Short form of mov, dst_reg = src_reg */
 134
 135 #define BPF_MOV64_REG(DST, SRC)                                 \
 136         ((struct bpf_insn) {                                    \
 137                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 138                 .dst_reg = DST,                                 \
 139                 .src_reg = SRC,                                 \
 140                 .off   = 0,                                     \
 141                 .imm   = 0 })
 142
 143 #define BPF_MOV32_REG(DST, SRC)                                 \
 144         ((struct bpf_insn) {                                    \
 145                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 146                 .dst_reg = DST,                                 \
 147                 .src_reg = SRC,                                 \
 148                 .off   = 0,                                     \
 149                 .imm   = 0 })
 150
 151 /* Short form of mov, dst_reg = imm32 */
 152
 153 #define BPF_MOV64_IMM(DST, IMM)                                 \
 154         ((struct bpf_insn) {                                    \
 155                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 156                 .dst_reg = DST,                                 \
 157                 .src_reg = 0,                                   \
 158                 .off   = 0,                                     \
 159                 .imm   = IMM })
 160
 161 #define BPF_MOV32_IMM(DST, IMM)                                 \
 162         ((struct bpf_insn) {                                    \
 163                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 164                 .dst_reg = DST,                                 \
 165                 .src_reg = 0,                                   \
 166                 .off   = 0,                                     \
 167                 .imm   = IMM })
 168
 169 /* Special form of mov32, used for doing explicit zero extension on dst. */
 170 #define BPF_ZEXT_REG(DST)                                       \
 171         ((struct bpf_insn) {                                    \
 172                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 173                 .dst_reg = DST,                                 \
 174                 .src_reg = DST,                                 \
 175                 .off   = 0,                                     \
 176                 .imm   = 1 })
 177
 178 static inline bool insn_is_zext(const struct bpf_insn *insn)
 179 {
 180         return insn->code == (BPF_ALU | BPF_MOV | BPF_X) && insn->imm == 1;
 181 }
 182
 183 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 184 #define BPF_LD_IMM64(DST, IMM)                                  \
 185         BPF_LD_IMM64_RAW(DST, 0, IMM)
 186
 187 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 188         ((struct bpf_insn) {                                    \
 189                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 190                 .dst_reg = DST,                                 \
 191                 .src_reg = SRC,                                 \
 192                 .off   = 0,                                     \
 193                 .imm   = (__u32) (IMM) }),                      \
 194         ((struct bpf_insn) {                                    \
 195                 .code  = 0, /* zero is reserved opcode */       \
 196                 .dst_reg = 0,                                   \
 197                 .src_reg = 0,                                   \
 198                 .off   = 0,                                     \
 199                 .imm   = ((__u64) (IMM)) >> 32 })
 200
 201 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 202 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 203         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 204
 205 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 206
 207 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 208         ((struct bpf_insn) {                                    \
 209                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 210                 .dst_reg = DST,                                 \
 211                 .src_reg = SRC,                                 \
 212                 .off   = 0,                                     \
 213                 .imm   = IMM })
 214
 215 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 216         ((struct bpf_insn) {                                    \
 217                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 218                 .dst_reg = DST,                                 \
 219                 .src_reg = SRC,                                 \
 220                 .off   = 0,                                     \
 221                 .imm   = IMM })
 222
 223 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 224
 225 #define BPF_LD_ABS(SIZE, IMM)                                   \
 226         ((struct bpf_insn) {                                    \
 227                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 228                 .dst_reg = 0,                                   \
 229                 .src_reg = 0,                                   \
 230                 .off   = 0,                                     \
 231                 .imm   = IMM })
 232
 233 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 234
 235 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 236         ((struct bpf_insn) {                                    \
 237                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 238                 .dst_reg = 0,                                   \
 239                 .src_reg = SRC,                                 \
 240                 .off   = 0,                                     \
 241                 .imm   = IMM })
 242
 243 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 244
 245 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 246         ((struct bpf_insn) {                                    \
 247                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 248                 .dst_reg = DST,                                 \
 249                 .src_reg = SRC,                                 \
 250                 .off   = OFF,                                   \
 251                 .imm   = 0 })
 252
 253 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 254
 255 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 256         ((struct bpf_insn) {                                    \
 257                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 258                 .dst_reg = DST,                                 \
 259                 .src_reg = SRC,                                 \
 260                 .off   = OFF,                                   \
 261                 .imm   = 0 })
 262
 263
 264 /*
 265  * Atomic operations:
 266  *
 267  *   BPF_ADD                  *(uint *) (dst_reg + off16) += src_reg
 268  *   BPF_AND                  *(uint *) (dst_reg + off16) &= src_reg
 269  *   BPF_OR                   *(uint *) (dst_reg + off16) |= src_reg
 270  *   BPF_XOR                  *(uint *) (dst_reg + off16) ^= src_reg
 271  *   BPF_ADD | BPF_FETCH      src_reg = atomic_fetch_add(dst_reg + off16, src_reg);
 272  *   BPF_AND | BPF_FETCH      src_reg = atomic_fetch_and(dst_reg + off16, src_reg);
 273  *   BPF_OR | BPF_FETCH       src_reg = atomic_fetch_or(dst_reg + off16, src_reg);
 274  *   BPF_XOR | BPF_FETCH      src_reg = atomic_fetch_xor(dst_reg + off16, src_reg);
 275  *   BPF_XCHG                 src_reg = atomic_xchg(dst_reg + off16, src_reg)
 276  *   BPF_CMPXCHG              r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg)
 277  */
 278
 279 #define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF)                  \
 280         ((struct bpf_insn) {                                    \
 281                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC, \
 282                 .dst_reg = DST,                                 \
 283                 .src_reg = SRC,                                 \
 284                 .off   = OFF,                                   \
 285                 .imm   = OP })
 286
 287 /* Legacy alias */
 288 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF)
 289
 290 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 291
 292 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 293         ((struct bpf_insn) {                                    \
 294                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 295                 .dst_reg = DST,                                 \
 296                 .src_reg = 0,                                   \
 297                 .off   = OFF,                                   \
 298                 .imm   = IMM })
 299
 300 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 301
 302 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 303         ((struct bpf_insn) {                                    \
 304                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 305                 .dst_reg = DST,                                 \
 306                 .src_reg = SRC,                                 \
 307                 .off   = OFF,                                   \
 308                 .imm   = 0 })
 309
 310 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 311
 312 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 313         ((struct bpf_insn) {                                    \
 314                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 315                 .dst_reg = DST,                                 \
 316                 .src_reg = 0,                                   \
 317                 .off   = OFF,                                   \
 318                 .imm   = IMM })
 319
 320 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
 321
 322 #define BPF_JMP32_REG(OP, DST, SRC, OFF)                        \
 323         ((struct bpf_insn) {                                    \
 324                 .code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,        \
 325                 .dst_reg = DST,                                 \
 326                 .src_reg = SRC,                                 \
 327                 .off   = OFF,                                   \
 328                 .imm   = 0 })
 329
 330 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
 331
 332 #define BPF_JMP32_IMM(OP, DST, IMM, OFF)                        \
 333         ((struct bpf_insn) {                                    \
 334                 .code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,        \
 335                 .dst_reg = DST,                                 \
 336                 .src_reg = 0,                                   \
 337                 .off   = OFF,                                   \
 338                 .imm   = IMM })
 339
 340 /* Unconditional jumps, goto pc + off16 */
 341
 342 #define BPF_JMP_A(OFF)                                          \
 343         ((struct bpf_insn) {                                    \
 344                 .code  = BPF_JMP | BPF_JA,                      \
 345                 .dst_reg = 0,                                   \
 346                 .src_reg = 0,                                   \
 347                 .off   = OFF,                                   \
 348                 .imm   = 0 })
 349
 350 /* Relative call */
 351
 352 #define BPF_CALL_REL(TGT)                                       \
 353         ((struct bpf_insn) {                                    \
 354                 .code  = BPF_JMP | BPF_CALL,                    \
 355                 .dst_reg = 0,                                   \
 356                 .src_reg = BPF_PSEUDO_CALL,                     \
 357                 .off   = 0,                                     \
 358                 .imm   = TGT })
 359
 360 /* Function call */
 361
 362 #define BPF_CAST_CALL(x)                                        \
 363                 ((u64 (*)(u64, u64, u64, u64, u64))(x))
 364
 365 #define BPF_EMIT_CALL(FUNC)                                     \
 366         ((struct bpf_insn) {                                    \
 367                 .code  = BPF_JMP | BPF_CALL,                    \
 368                 .dst_reg = 0,                                   \
 369                 .src_reg = 0,                                   \
 370                 .off   = 0,                                     \
 371                 .imm   = ((FUNC) - __bpf_call_base) })
 372
 373 /* Raw code statement block */
 374
 375 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 376         ((struct bpf_insn) {                                    \
 377                 .code  = CODE,                                  \
 378                 .dst_reg = DST,                                 \
 379                 .src_reg = SRC,                                 \
 380                 .off   = OFF,                                   \
 381                 .imm   = IMM })
 382
 383 /* Program exit */
 384
 385 #define BPF_EXIT_INSN()                                         \
 386         ((struct bpf_insn) {                                    \
 387                 .code  = BPF_JMP | BPF_EXIT,                    \
 388                 .dst_reg = 0,                                   \
 389                 .src_reg = 0,                                   \
 390                 .off   = 0,                                     \
 391                 .imm   = 0 })
 392
 393 /* Internal classic blocks for direct assignment */
 394
 395 #define __BPF_STMT(CODE, K)                                     \
 396         ((struct sock_filter) BPF_STMT(CODE, K))
 397
 398 #define __BPF_JUMP(CODE, K, JT, JF)                             \
 399         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 400
 401 #define bytes_to_bpf_size(bytes)                                \
 402 ({                                                              \
 403         int bpf_size = -EINVAL;                                 \
 404                                                                 \
 405         if (bytes == sizeof(u8))                                \
 406                 bpf_size = BPF_B;                               \
 407         else if (bytes == sizeof(u16))                          \
 408                 bpf_size = BPF_H;                               \
 409         else if (bytes == sizeof(u32))                          \
 410                 bpf_size = BPF_W;                               \
 411         else if (bytes == sizeof(u64))                          \
 412                 bpf_size = BPF_DW;                              \
 413                                                                 \
 414         bpf_size;                                               \
 415 })
 416
 417 #define bpf_size_to_bytes(bpf_size)                             \
 418 ({                                                              \
 419         int bytes = -EINVAL;                                    \
 420                                                                 \
 421         if (bpf_size == BPF_B)                                  \
 422                 bytes = sizeof(u8);                             \
 423         else if (bpf_size == BPF_H)                             \
 424                 bytes = sizeof(u16);                            \
 425         else if (bpf_size == BPF_W)                             \
 426                 bytes = sizeof(u32);                            \
 427         else if (bpf_size == BPF_DW)                            \
 428                 bytes = sizeof(u64);                            \
 429                                                                 \
 430         bytes;                                                  \
 431 })
 432
 433 #define BPF_SIZEOF(type)                                        \
 434         ({                                                      \
 435                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 436                 BUILD_BUG_ON(__size < 0);                       \
 437                 __size;                                         \
 438         })
 439
 440 #define BPF_FIELD_SIZEOF(type, field)                           \
 441         ({                                                      \
 442                 const int __size = bytes_to_bpf_size(sizeof_field(type, field)); \
 443                 BUILD_BUG_ON(__size < 0);                       \
 444                 __size;                                         \
 445         })
 446
 447 #define BPF_LDST_BYTES(insn)                                    \
 448         ({                                                      \
 449                 const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
 450                 WARN_ON(__size < 0);                            \
 451                 __size;                                         \
 452         })
 453
 454 #define __BPF_MAP_0(m, v, ...) v
 455 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 456 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 457 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 458 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 459 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 460
 461 #define __BPF_REG_0(...) __BPF_PAD(5)
 462 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 463 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 464 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 465 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 466 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 467
 468 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 469 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 470
 471 #define __BPF_CAST(t, a)                                                       \
 472         (__force t)                                                            \
 473         (__force                                                               \
 474          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 475                                       (unsigned long)0, (t)0))) a
 476 #define __BPF_V void
 477 #define __BPF_N
 478
 479 #define __BPF_DECL_ARGS(t, a) t   a
 480 #define __BPF_DECL_REGS(t, a) u64 a
 481
 482 #define __BPF_PAD(n)                                                           \
 483         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 484                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 485
 486 #define BPF_CALL_x(x, name, ...)                                               \
 487         static __always_inline                                                 \
 488         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 489         typedef u64 (*btf_##name)(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
 490         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 491         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 492         {                                                                      \
 493                 return ((btf_##name)____##name)(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 494         }                                                                      \
 495         static __always_inline                                                 \
 496         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 497
 498 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 499 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 500 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 501 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 502 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 503 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 504
 505 #define bpf_ctx_range(TYPE, MEMBER)                                             \
 506         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 507 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)                              \
 508         offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
 509 #if BITS_PER_LONG == 64
 510 # define bpf_ctx_range_ptr(TYPE, MEMBER)                                        \
 511         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 512 #else
 513 # define bpf_ctx_range_ptr(TYPE, MEMBER)                                        \
 514         offsetof(TYPE, MEMBER) ... offsetof(TYPE, MEMBER) + 8 - 1
 515 #endif /* BITS_PER_LONG == 64 */
 516
 517 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)                            \
 518         ({                                                                      \
 519                 BUILD_BUG_ON(sizeof_field(TYPE, MEMBER) != (SIZE));             \
 520                 *(PTR_SIZE) = (SIZE);                                           \
 521                 offsetof(TYPE, MEMBER);                                         \
 522         })
 523
 524 /* A struct sock_filter is architecture independent. */
 525 struct compat_sock_fprog {
 526         u16             len;
 527         compat_uptr_t   filter; /* struct sock_filter * */
 528 };
 529
 530 struct sock_fprog_kern {
 531         u16                     len;
 532         struct sock_filter      *filter;
 533 };
 534
 535 /* Some arches need doubleword alignment for their instructions and/or data */
 536 #define BPF_IMAGE_ALIGNMENT 8
 537
 538 struct bpf_binary_header {
 539         u32 pages;
 540         u8 image[] __aligned(BPF_IMAGE_ALIGNMENT);
 541 };
 542
 543 struct bpf_prog_stats {
 544         u64 cnt;
 545         u64 nsecs;
 546         u64 misses;
 547         struct u64_stats_sync syncp;
 548 } __aligned(2 * sizeof(u64));
 549
 550 struct bpf_prog {
 551         u16                     pages;          /* Number of allocated pages */
 552         u16                     jited:1,        /* Is our filter JIT'ed? */
 553                                 jit_requested:1,/* archs need to JIT the prog */
 554                                 gpl_compatible:1, /* Is filter GPL compatible? */
 555                                 cb_access:1,    /* Is control block accessed? */
 556                                 dst_needed:1,   /* Do we need dst entry? */
 557                                 blinded:1,      /* Was blinded */
 558                                 is_func:1,      /* program is a bpf function */
 559                                 kprobe_override:1, /* Do we override a kprobe? */
 560                                 has_callchain_buf:1, /* callchain buffer allocated? */
 561                                 enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */
 562                                 call_get_stack:1; /* Do we call bpf_get_stack() or bpf_get_stackid() */
 563         enum bpf_prog_type      type;           /* Type of BPF program */
 564         enum bpf_attach_type    expected_attach_type; /* For some prog types */
 565         u32                     len;            /* Number of filter blocks */
 566         u32                     jited_len;      /* Size of jited insns in bytes */
 567         u8                      tag[BPF_TAG_SIZE];
 568         struct bpf_prog_stats __percpu *stats;
 569         int __percpu            *active;
 570         unsigned int            (*bpf_func)(const void *ctx,
 571                                             const struct bpf_insn *insn);
 572         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 573         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 574         /* Instructions for interpreter */
 575         struct sock_filter      insns[0];
 576         struct bpf_insn         insnsi[];
 577 };
 578
 579 struct sk_filter {
 580         refcount_t      refcnt;
 581         struct rcu_head rcu;
 582         struct bpf_prog *prog;
 583 };
 584
 585 DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 586
 587 #define __BPF_PROG_RUN(prog, ctx, dfunc)        ({                      \
 588         u32 __ret;                                                      \
 589         cant_migrate();                                                 \
 590         if (static_branch_unlikely(&bpf_stats_enabled_key)) {           \
 591                 struct bpf_prog_stats *__stats;                         \
 592                 u64 __start = sched_clock();                            \
 593                 __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func);   \
 594                 __stats = this_cpu_ptr(prog->stats);                    \
 595                 u64_stats_update_begin(&__stats->syncp);                \
 596                 __stats->cnt++;                                         \
 597                 __stats->nsecs += sched_clock() - __start;              \
 598                 u64_stats_update_end(&__stats->syncp);                  \
 599         } else {                                                        \
 600                 __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func);   \
 601         }                                                               \
 602         __ret; })
 603
 604 #define BPF_PROG_RUN(prog, ctx)                                         \
 605         __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func)
 606
 607 /*
 608  * Use in preemptible and therefore migratable context to make sure that
 609  * the execution of the BPF program runs on one CPU.
 610  *
 611  * This uses migrate_disable/enable() explicitly to document that the
 612  * invocation of a BPF program does not require reentrancy protection
 613  * against a BPF program which is invoked from a preempting task.
 614  *
 615  * For non RT enabled kernels migrate_disable/enable() maps to
 616  * preempt_disable/enable(), i.e. it disables also preemption.
 617  */
 618 static inline u32 bpf_prog_run_pin_on_cpu(const struct bpf_prog *prog,
 619                                           const void *ctx)
 620 {
 621         u32 ret;
 622
 623         migrate_disable();
 624         ret = __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func);
 625         migrate_enable();
 626         return ret;
 627 }
 628
 629 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 630
 631 struct bpf_skb_data_end {
 632         struct qdisc_skb_cb qdisc_cb;
 633         void *data_meta;
 634         void *data_end;
 635 };
 636
 637 struct bpf_nh_params {
 638         u32 nh_family;
 639         union {
 640                 u32 ipv4_nh;
 641                 struct in6_addr ipv6_nh;
 642         };
 643 };
 644
 645 struct bpf_redirect_info {
 646         u32 flags;
 647         u32 tgt_index;
 648         void *tgt_value;
 649         struct bpf_map *map;
 650         u32 map_id;
 651         enum bpf_map_type map_type;
 652         u32 kern_flags;
 653         struct bpf_nh_params nh;
 654 };
 655
 656 DECLARE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info);
 657
 658 /* flags for bpf_redirect_info kern_flags */
 659 #define BPF_RI_F_RF_NO_DIRECT   BIT(0)  /* no napi_direct on return_frame */
 660
 661 /* Compute the linear packet data range [data, data_end) which
 662  * will be accessed by various program types (cls_bpf, act_bpf,
 663  * lwt, ...). Subsystems allowing direct data access must (!)
 664  * ensure that cb[] area can be written to when BPF program is
 665  * invoked (otherwise cb[] save/restore is necessary).
 666  */
 667 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
 668 {
 669         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 670
 671         BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));
 672         cb->data_meta = skb->data - skb_metadata_len(skb);
 673         cb->data_end  = skb->data + skb_headlen(skb);
 674 }
 675
 676 /* Similar to bpf_compute_data_pointers(), except that save orginal
 677  * data in cb->data and cb->meta_data for restore.
 678  */
 679 static inline void bpf_compute_and_save_data_end(
 680         struct sk_buff *skb, void **saved_data_end)
 681 {
 682         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 683
 684         *saved_data_end = cb->data_end;
 685         cb->data_end  = skb->data + skb_headlen(skb);
 686 }
 687
 688 /* Restore data saved by bpf_compute_data_pointers(). */
 689 static inline void bpf_restore_data_end(
 690         struct sk_buff *skb, void *saved_data_end)
 691 {
 692         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 693
 694         cb->data_end = saved_data_end;
 695 }
 696
 697 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 698 {
 699         /* eBPF programs may read/write skb->cb[] area to transfer meta
 700          * data between tail calls. Since this also needs to work with
 701          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 702          *
 703          * In some socket filter cases, the cb unfortunately needs to be
 704          * saved/restored so that protocol specific skb->cb[] data won't
 705          * be lost. In any case, due to unpriviledged eBPF programs
 706          * attached to sockets, we need to clear the bpf_skb_cb() area
 707          * to not leak previous contents to user space.
 708          */
 709         BUILD_BUG_ON(sizeof_field(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 710         BUILD_BUG_ON(sizeof_field(struct __sk_buff, cb) !=
 711                      sizeof_field(struct qdisc_skb_cb, data));
 712
 713         return qdisc_skb_cb(skb)->data;
 714 }
 715
 716 /* Must be invoked with migration disabled */
 717 static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
 718                                          struct sk_buff *skb)
 719 {
 720         u8 *cb_data = bpf_skb_cb(skb);
 721         u8 cb_saved[BPF_SKB_CB_LEN];
 722         u32 res;
 723
 724         if (unlikely(prog->cb_access)) {
 725                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 726                 memset(cb_data, 0, sizeof(cb_saved));
 727         }
 728
 729         res = BPF_PROG_RUN(prog, skb);
 730
 731         if (unlikely(prog->cb_access))
 732                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 733
 734         return res;
 735 }
 736
 737 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 738                                        struct sk_buff *skb)
 739 {
 740         u32 res;
 741
 742         migrate_disable();
 743         res = __bpf_prog_run_save_cb(prog, skb);
 744         migrate_enable();
 745         return res;
 746 }
 747
 748 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 749                                         struct sk_buff *skb)
 750 {
 751         u8 *cb_data = bpf_skb_cb(skb);
 752         u32 res;
 753
 754         if (unlikely(prog->cb_access))
 755                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 756
 757         res = bpf_prog_run_pin_on_cpu(prog, skb);
 758         return res;
 759 }
 760
 761 DECLARE_BPF_DISPATCHER(xdp)
 762
 763 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 764                                             struct xdp_buff *xdp)
 765 {
 766         /* Driver XDP hooks are invoked within a single NAPI poll cycle and thus
 767          * under local_bh_disable(), which provides the needed RCU protection
 768          * for accessing map entries.
 769          */
 770         return __BPF_PROG_RUN(prog, xdp, BPF_DISPATCHER_FUNC(xdp));
 771 }
 772
 773 void bpf_prog_change_xdp(struct bpf_prog *prev_prog, struct bpf_prog *prog);
 774
 775 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 776 {
 777         return prog->len * sizeof(struct bpf_insn);
 778 }
 779
 780 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 781 {
 782         return round_up(bpf_prog_insn_size(prog) +
 783                         sizeof(__be64) + 1, SHA1_BLOCK_SIZE);
 784 }
 785
 786 static inline unsigned int bpf_prog_size(unsigned int proglen)
 787 {
 788         return max(sizeof(struct bpf_prog),
 789                    offsetof(struct bpf_prog, insns[proglen]));
 790 }
 791
 792 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 793 {
 794         /* When classic BPF programs have been loaded and the arch
 795          * does not have a classic BPF JIT (anymore), they have been
 796          * converted via bpf_migrate_filter() to eBPF and thus always
 797          * have an unspec program type.
 798          */
 799         return prog->type == BPF_PROG_TYPE_UNSPEC;
 800 }
 801
 802 static inline u32 bpf_ctx_off_adjust_machine(u32 size)
 803 {
 804         const u32 size_machine = sizeof(unsigned long);
 805
 806         if (size > size_machine && size % size_machine == 0)
 807                 size = size_machine;
 808
 809         return size;
 810 }
 811
 812 static inline bool
 813 bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
 814 {
 815         return size <= size_default && (size & (size - 1)) == 0;
 816 }
 817
 818 static inline u8
 819 bpf_ctx_narrow_access_offset(u32 off, u32 size, u32 size_default)
 820 {
 821         u8 access_off = off & (size_default - 1);
 822
 823 #ifdef __LITTLE_ENDIAN
 824         return access_off;
 825 #else
 826         return size_default - (access_off + size);
 827 #endif
 828 }
 829
 830 #define bpf_ctx_wide_access_ok(off, size, type, field)                  \
 831         (size == sizeof(__u64) &&                                       \
 832         off >= offsetof(type, field) &&                                 \
 833         off + sizeof(__u64) <= offsetofend(type, field) &&              \
 834         off % sizeof(__u64) == 0)
 835
 836 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 837
 838 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 839 {
 840 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
 841         if (!fp->jited) {
 842                 set_vm_flush_reset_perms(fp);
 843                 set_memory_ro((unsigned long)fp, fp->pages);
 844         }
 845 #endif
 846 }
 847
 848 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 849 {
 850         set_vm_flush_reset_perms(hdr);
 851         set_memory_ro((unsigned long)hdr, hdr->pages);
 852         set_memory_x((unsigned long)hdr, hdr->pages);
 853 }
 854
 855 static inline struct bpf_binary_header *
 856 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 857 {
 858         unsigned long real_start = (unsigned long)fp->bpf_func;
 859         unsigned long addr = real_start & PAGE_MASK;
 860
 861         return (void *)addr;
 862 }
 863
 864 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 865 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 866 {
 867         return sk_filter_trim_cap(sk, skb, 1);
 868 }
 869
 870 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 871 void bpf_prog_free(struct bpf_prog *fp);
 872
 873 bool bpf_opcode_in_insntable(u8 code);
 874
 875 void bpf_prog_free_linfo(struct bpf_prog *prog);
 876 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 877                                const u32 *insn_to_jit_off);
 878 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);
 879 void bpf_prog_jit_attempt_done(struct bpf_prog *prog);
 880
 881 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 882 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags);
 883 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 884                                   gfp_t gfp_extra_flags);
 885 void __bpf_prog_free(struct bpf_prog *fp);
 886
 887 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 888 {
 889         __bpf_prog_free(fp);
 890 }
 891
 892 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 893                                        unsigned int flen);
 894
 895 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 896 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 897                               bpf_aux_classic_check_t trans, bool save_orig);
 898 void bpf_prog_destroy(struct bpf_prog *fp);
 899
 900 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 901 int sk_attach_bpf(u32 ufd, struct sock *sk);
 902 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 903 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 904 void sk_reuseport_prog_free(struct bpf_prog *prog);
 905 int sk_detach_filter(struct sock *sk);
 906 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 907                   unsigned int len);
 908
 909 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 910 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 911
 912 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 913 #define __bpf_call_base_args \
 914         ((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
 915          (void *)__bpf_call_base)
 916
 917 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 918 void bpf_jit_compile(struct bpf_prog *prog);
 919 bool bpf_jit_needs_zext(void);
 920 bool bpf_jit_supports_kfunc_call(void);
 921 bool bpf_helper_changes_pkt_data(void *func);
 922
 923 static inline bool bpf_dump_raw_ok(const struct cred *cred)
 924 {
 925         /* Reconstruction of call-sites is dependent on kallsyms,
 926          * thus make dump the same restriction.
 927          */
 928         return kallsyms_show_value(cred);
 929 }
 930
 931 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 932                                        const struct bpf_insn *patch, u32 len);
 933 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt);
 934
 935 void bpf_clear_redirect_map(struct bpf_map *map);
 936
 937 static inline bool xdp_return_frame_no_direct(void)
 938 {
 939         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 940
 941         return ri->kern_flags & BPF_RI_F_RF_NO_DIRECT;
 942 }
 943
 944 static inline void xdp_set_return_frame_no_direct(void)
 945 {
 946         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 947
 948         ri->kern_flags |= BPF_RI_F_RF_NO_DIRECT;
 949 }
 950
 951 static inline void xdp_clear_return_frame_no_direct(void)
 952 {
 953         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 954
 955         ri->kern_flags &= ~BPF_RI_F_RF_NO_DIRECT;
 956 }
 957
 958 static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
 959                                  unsigned int pktlen)
 960 {
 961         unsigned int len;
 962
 963         if (unlikely(!(fwd->flags & IFF_UP)))
 964                 return -ENETDOWN;
 965
 966         len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN;
 967         if (pktlen > len)
 968                 return -EMSGSIZE;
 969
 970         return 0;
 971 }
 972
 973 /* The pair of xdp_do_redirect and xdp_do_flush MUST be called in the
 974  * same cpu context. Further for best results no more than a single map
 975  * for the do_redirect/do_flush pair should be used. This limitation is
 976  * because we only track one map and force a flush when the map changes.
 977  * This does not appear to be a real limitation for existing software.
 978  */
 979 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 980                             struct xdp_buff *xdp, struct bpf_prog *prog);
 981 int xdp_do_redirect(struct net_device *dev,
 982                     struct xdp_buff *xdp,
 983                     struct bpf_prog *prog);
 984 void xdp_do_flush(void);
 985
 986 /* The xdp_do_flush_map() helper has been renamed to drop the _map suffix, as
 987  * it is no longer only flushing maps. Keep this define for compatibility
 988  * until all drivers are updated - do not use xdp_do_flush_map() in new code!
 989  */
 990 #define xdp_do_flush_map xdp_do_flush
 991
 992 void bpf_warn_invalid_xdp_action(u32 act);
 993
 994 #ifdef CONFIG_INET
 995 struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
 996                                   struct bpf_prog *prog, struct sk_buff *skb,
 997                                   struct sock *migrating_sk,
 998                                   u32 hash);
 999 #else
1000 static inline struct sock *
1001 bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
1002                      struct bpf_prog *prog, struct sk_buff *skb,
1003                      struct sock *migrating_sk,
1004                      u32 hash)
1005 {
1006         return NULL;
1007 }
1008 #endif
1009
1010 #ifdef CONFIG_BPF_JIT
1011 extern int bpf_jit_enable;
1012 extern int bpf_jit_harden;
1013 extern int bpf_jit_kallsyms;
1014 extern long bpf_jit_limit;
1015
1016 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
1017
1018 struct bpf_binary_header *
1019 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1020                      unsigned int alignment,
1021                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
1022 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
1023 u64 bpf_jit_alloc_exec_limit(void);
1024 void *bpf_jit_alloc_exec(unsigned long size);
1025 void bpf_jit_free_exec(void *addr);
1026 void bpf_jit_free(struct bpf_prog *fp);
1027
1028 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
1029                                 struct bpf_jit_poke_descriptor *poke);
1030
1031 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1032                           const struct bpf_insn *insn, bool extra_pass,
1033                           u64 *func_addr, bool *func_addr_fixed);
1034
1035 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
1036 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
1037
1038 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
1039                                 u32 pass, void *image)
1040 {
1041         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
1042                proglen, pass, image, current->comm, task_pid_nr(current));
1043
1044         if (image)
1045                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
1046                                16, 1, image, proglen, false);
1047 }
1048
1049 static inline bool bpf_jit_is_ebpf(void)
1050 {
1051 # ifdef CONFIG_HAVE_EBPF_JIT
1052         return true;
1053 # else
1054         return false;
1055 # endif
1056 }
1057
1058 static inline bool ebpf_jit_enabled(void)
1059 {
1060         return bpf_jit_enable && bpf_jit_is_ebpf();
1061 }
1062
1063 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
1064 {
1065         return fp->jited && bpf_jit_is_ebpf();
1066 }
1067
1068 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
1069 {
1070         /* These are the prerequisites, should someone ever have the
1071          * idea to call blinding outside of them, we make sure to
1072          * bail out.
1073          */
1074         if (!bpf_jit_is_ebpf())
1075                 return false;
1076         if (!prog->jit_requested)
1077                 return false;
1078         if (!bpf_jit_harden)
1079                 return false;
1080         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
1081                 return false;
1082
1083         return true;
1084 }
1085
1086 static inline bool bpf_jit_kallsyms_enabled(void)
1087 {
1088         /* There are a couple of corner cases where kallsyms should
1089          * not be enabled f.e. on hardening.
1090          */
1091         if (bpf_jit_harden)
1092                 return false;
1093         if (!bpf_jit_kallsyms)
1094                 return false;
1095         if (bpf_jit_kallsyms == 1)
1096                 return true;
1097
1098         return false;
1099 }
1100
1101 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
1102                                  unsigned long *off, char *sym);
1103 bool is_bpf_text_address(unsigned long addr);
1104 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
1105                     char *sym);
1106
1107 static inline const char *
1108 bpf_address_lookup(unsigned long addr, unsigned long *size,
1109                    unsigned long *off, char **modname, char *sym)
1110 {
1111         const char *ret = __bpf_address_lookup(addr, size, off, sym);
1112
1113         if (ret && modname)
1114                 *modname = NULL;
1115         return ret;
1116 }
1117
1118 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
1119 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
1120
1121 #else /* CONFIG_BPF_JIT */
1122
1123 static inline bool ebpf_jit_enabled(void)
1124 {
1125         return false;
1126 }
1127
1128 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
1129 {
1130         return false;
1131 }
1132
1133 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
1134 {
1135         return false;
1136 }
1137
1138 static inline int
1139 bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
1140                             struct bpf_jit_poke_descriptor *poke)
1141 {
1142         return -ENOTSUPP;
1143 }
1144
1145 static inline void bpf_jit_free(struct bpf_prog *fp)
1146 {
1147         bpf_prog_unlock_free(fp);
1148 }
1149
1150 static inline bool bpf_jit_kallsyms_enabled(void)
1151 {
1152         return false;
1153 }
1154
1155 static inline const char *
1156 __bpf_address_lookup(unsigned long addr, unsigned long *size,
1157                      unsigned long *off, char *sym)
1158 {
1159         return NULL;
1160 }
1161
1162 static inline bool is_bpf_text_address(unsigned long addr)
1163 {
1164         return false;
1165 }
1166
1167 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
1168                                   char *type, char *sym)
1169 {
1170         return -ERANGE;
1171 }
1172
1173 static inline const char *
1174 bpf_address_lookup(unsigned long addr, unsigned long *size,
1175                    unsigned long *off, char **modname, char *sym)
1176 {
1177         return NULL;
1178 }
1179
1180 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
1181 {
1182 }
1183
1184 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
1185 {
1186 }
1187
1188 #endif /* CONFIG_BPF_JIT */
1189
1190 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
1191
1192 #define BPF_ANC         BIT(15)
1193
1194 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
1195 {
1196         switch (first->code) {
1197         case BPF_RET | BPF_K:
1198         case BPF_LD | BPF_W | BPF_LEN:
1199                 return false;
1200
1201         case BPF_LD | BPF_W | BPF_ABS:
1202         case BPF_LD | BPF_H | BPF_ABS:
1203         case BPF_LD | BPF_B | BPF_ABS:
1204                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
1205                         return true;
1206                 return false;
1207
1208         default:
1209                 return true;
1210         }
1211 }
1212
1213 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
1214 {
1215         BUG_ON(ftest->code & BPF_ANC);
1216
1217         switch (ftest->code) {
1218         case BPF_LD | BPF_W | BPF_ABS:
1219         case BPF_LD | BPF_H | BPF_ABS:
1220         case BPF_LD | BPF_B | BPF_ABS:
1221 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
1222                                 return BPF_ANC | SKF_AD_##CODE
1223                 switch (ftest->k) {
1224                 BPF_ANCILLARY(PROTOCOL);
1225                 BPF_ANCILLARY(PKTTYPE);
1226                 BPF_ANCILLARY(IFINDEX);
1227                 BPF_ANCILLARY(NLATTR);
1228                 BPF_ANCILLARY(NLATTR_NEST);
1229                 BPF_ANCILLARY(MARK);
1230                 BPF_ANCILLARY(QUEUE);
1231                 BPF_ANCILLARY(HATYPE);
1232                 BPF_ANCILLARY(RXHASH);
1233                 BPF_ANCILLARY(CPU);
1234                 BPF_ANCILLARY(ALU_XOR_X);
1235                 BPF_ANCILLARY(VLAN_TAG);
1236                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
1237                 BPF_ANCILLARY(PAY_OFFSET);
1238                 BPF_ANCILLARY(RANDOM);
1239                 BPF_ANCILLARY(VLAN_TPID);
1240                 }
1241                 fallthrough;
1242         default:
1243                 return ftest->code;
1244         }
1245 }
1246
1247 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
1248                                            int k, unsigned int size);
1249
1250 static inline int bpf_tell_extensions(void)
1251 {
1252         return SKF_AD_MAX;
1253 }
1254
1255 struct bpf_sock_addr_kern {
1256         struct sock *sk;
1257         struct sockaddr *uaddr;
1258         /* Temporary "register" to make indirect stores to nested structures
1259          * defined above. We need three registers to make such a store, but
1260          * only two (src and dst) are available at convert_ctx_access time
1261          */
1262         u64 tmp_reg;
1263         void *t_ctx;    /* Attach type specific context. */
1264 };
1265
1266 struct bpf_sock_ops_kern {
1267         struct  sock *sk;
1268         union {
1269                 u32 args[4];
1270                 u32 reply;
1271                 u32 replylong[4];
1272         };
1273         struct sk_buff  *syn_skb;
1274         struct sk_buff  *skb;
1275         void    *skb_data_end;
1276         u8      op;
1277         u8      is_fullsock;
1278         u8      remaining_opt_len;
1279         u64     temp;                   /* temp and everything after is not
1280                                          * initialized to 0 before calling
1281                                          * the BPF program. New fields that
1282                                          * should be initialized to 0 should
1283                                          * be inserted before temp.
1284                                          * temp is scratch storage used by
1285                                          * sock_ops_convert_ctx_access
1286                                          * as temporary storage of a register.
1287                                          */
1288 };
1289
1290 struct bpf_sysctl_kern {
1291         struct ctl_table_header *head;
1292         struct ctl_table *table;
1293         void *cur_val;
1294         size_t cur_len;
1295         void *new_val;
1296         size_t new_len;
1297         int new_updated;
1298         int write;
1299         loff_t *ppos;
1300         /* Temporary "register" for indirect stores to ppos. */
1301         u64 tmp_reg;
1302 };
1303
1304 #define BPF_SOCKOPT_KERN_BUF_SIZE       32
1305 struct bpf_sockopt_buf {
1306         u8              data[BPF_SOCKOPT_KERN_BUF_SIZE];
1307 };
1308
1309 struct bpf_sockopt_kern {
1310         struct sock     *sk;
1311         u8              *optval;
1312         u8              *optval_end;
1313         s32             level;
1314         s32             optname;
1315         s32             optlen;
1316         s32             retval;
1317 };
1318
1319 int copy_bpf_fprog_from_user(struct sock_fprog *dst, sockptr_t src, int len);
1320
1321 struct bpf_sk_lookup_kern {
1322         u16             family;
1323         u16             protocol;
1324         __be16          sport;
1325         u16             dport;
1326         struct {
1327                 __be32 saddr;
1328                 __be32 daddr;
1329         } v4;
1330         struct {
1331                 const struct in6_addr *saddr;
1332                 const struct in6_addr *daddr;
1333         } v6;
1334         struct sock     *selected_sk;
1335         bool            no_reuseport;
1336 };
1337
1338 extern struct static_key_false bpf_sk_lookup_enabled;
1339
1340 /* Runners for BPF_SK_LOOKUP programs to invoke on socket lookup.
1341  *
1342  * Allowed return values for a BPF SK_LOOKUP program are SK_PASS and
1343  * SK_DROP. Their meaning is as follows:
1344  *
1345  *  SK_PASS && ctx.selected_sk != NULL: use selected_sk as lookup result
1346  *  SK_PASS && ctx.selected_sk == NULL: continue to htable-based socket lookup
1347  *  SK_DROP                           : terminate lookup with -ECONNREFUSED
1348  *
1349  * This macro aggregates return values and selected sockets from
1350  * multiple BPF programs according to following rules in order:
1351  *
1352  *  1. If any program returned SK_PASS and a non-NULL ctx.selected_sk,
1353  *     macro result is SK_PASS and last ctx.selected_sk is used.
1354  *  2. If any program returned SK_DROP return value,
1355  *     macro result is SK_DROP.
1356  *  3. Otherwise result is SK_PASS and ctx.selected_sk is NULL.
1357  *
1358  * Caller must ensure that the prog array is non-NULL, and that the
1359  * array as well as the programs it contains remain valid.
1360  */
1361 #define BPF_PROG_SK_LOOKUP_RUN_ARRAY(array, ctx, func)                  \
1362         ({                                                              \
1363                 struct bpf_sk_lookup_kern *_ctx = &(ctx);               \
1364                 struct bpf_prog_array_item *_item;                      \
1365                 struct sock *_selected_sk = NULL;                       \
1366                 bool _no_reuseport = false;                             \
1367                 struct bpf_prog *_prog;                                 \
1368                 bool _all_pass = true;                                  \
1369                 u32 _ret;                                               \
1370                                                                         \
1371                 migrate_disable();                                      \
1372                 _item = &(array)->items[0];                             \
1373                 while ((_prog = READ_ONCE(_item->prog))) {              \
1374                         /* restore most recent selection */             \
1375                         _ctx->selected_sk = _selected_sk;               \
1376                         _ctx->no_reuseport = _no_reuseport;             \
1377                                                                         \
1378                         _ret = func(_prog, _ctx);                       \
1379                         if (_ret == SK_PASS && _ctx->selected_sk) {     \
1380                                 /* remember last non-NULL socket */     \
1381                                 _selected_sk = _ctx->selected_sk;       \
1382                                 _no_reuseport = _ctx->no_reuseport;     \
1383                         } else if (_ret == SK_DROP && _all_pass) {      \
1384                                 _all_pass = false;                      \
1385                         }                                               \
1386                         _item++;                                        \
1387                 }                                                       \
1388                 _ctx->selected_sk = _selected_sk;                       \
1389                 _ctx->no_reuseport = _no_reuseport;                     \
1390                 migrate_enable();                                       \
1391                 _all_pass || _selected_sk ? SK_PASS : SK_DROP;          \
1392          })
1393
1394 static inline bool bpf_sk_lookup_run_v4(struct net *net, int protocol,
1395                                         const __be32 saddr, const __be16 sport,
1396                                         const __be32 daddr, const u16 dport,
1397                                         struct sock **psk)
1398 {
1399         struct bpf_prog_array *run_array;
1400         struct sock *selected_sk = NULL;
1401         bool no_reuseport = false;
1402
1403         rcu_read_lock();
1404         run_array = rcu_dereference(net->bpf.run_array[NETNS_BPF_SK_LOOKUP]);
1405         if (run_array) {
1406                 struct bpf_sk_lookup_kern ctx = {
1407                         .family         = AF_INET,
1408                         .protocol       = protocol,
1409                         .v4.saddr       = saddr,
1410                         .v4.daddr       = daddr,
1411                         .sport          = sport,
1412                         .dport          = dport,
1413                 };
1414                 u32 act;
1415
1416                 act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, BPF_PROG_RUN);
1417                 if (act == SK_PASS) {
1418                         selected_sk = ctx.selected_sk;
1419                         no_reuseport = ctx.no_reuseport;
1420                 } else {
1421                         selected_sk = ERR_PTR(-ECONNREFUSED);
1422                 }
1423         }
1424         rcu_read_unlock();
1425         *psk = selected_sk;
1426         return no_reuseport;
1427 }
1428
1429 #if IS_ENABLED(CONFIG_IPV6)
1430 static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol,
1431                                         const struct in6_addr *saddr,
1432                                         const __be16 sport,
1433                                         const struct in6_addr *daddr,
1434                                         const u16 dport,
1435                                         struct sock **psk)
1436 {
1437         struct bpf_prog_array *run_array;
1438         struct sock *selected_sk = NULL;
1439         bool no_reuseport = false;
1440
1441         rcu_read_lock();
1442         run_array = rcu_dereference(net->bpf.run_array[NETNS_BPF_SK_LOOKUP]);
1443         if (run_array) {
1444                 struct bpf_sk_lookup_kern ctx = {
1445                         .family         = AF_INET6,
1446                         .protocol       = protocol,
1447                         .v6.saddr       = saddr,
1448                         .v6.daddr       = daddr,
1449                         .sport          = sport,
1450                         .dport          = dport,
1451                 };
1452                 u32 act;
1453
1454                 act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, BPF_PROG_RUN);
1455                 if (act == SK_PASS) {
1456                         selected_sk = ctx.selected_sk;
1457                         no_reuseport = ctx.no_reuseport;
1458                 } else {
1459                         selected_sk = ERR_PTR(-ECONNREFUSED);
1460                 }
1461         }
1462         rcu_read_unlock();
1463         *psk = selected_sk;
1464         return no_reuseport;
1465 }
1466 #endif /* IS_ENABLED(CONFIG_IPV6) */
1467
1468 static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex,
1469                                                   u64 flags, const u64 flag_mask,
1470                                                   void *lookup_elem(struct bpf_map *map, u32 key))
1471 {
1472         struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
1473         const u64 action_mask = XDP_ABORTED | XDP_DROP | XDP_PASS | XDP_TX;
1474
1475         /* Lower bits of the flags are used as return code on lookup failure */
1476         if (unlikely(flags & ~(action_mask | flag_mask)))
1477                 return XDP_ABORTED;
1478
1479         ri->tgt_value = lookup_elem(map, ifindex);
1480         if (unlikely(!ri->tgt_value) && !(flags & BPF_F_BROADCAST)) {
1481                 /* If the lookup fails we want to clear out the state in the
1482                  * redirect_info struct completely, so that if an eBPF program
1483                  * performs multiple lookups, the last one always takes
1484                  * precedence.
1485                  */
1486                 ri->map_id = INT_MAX; /* Valid map id idr range: [1,INT_MAX[ */
1487                 ri->map_type = BPF_MAP_TYPE_UNSPEC;
1488                 return flags & action_mask;
1489         }
1490
1491         ri->tgt_index = ifindex;
1492         ri->map_id = map->id;
1493         ri->map_type = map->map_type;
1494
1495         if (flags & BPF_F_BROADCAST) {
1496                 WRITE_ONCE(ri->map, map);
1497                 ri->flags = flags;
1498         } else {
1499                 WRITE_ONCE(ri->map, NULL);
1500                 ri->flags = 0;
1501         }
1502
1503         return XDP_REDIRECT;
1504 }
1505
1506 #endif /* __LINUX_FILTER_H__ */