include/linux/filter.h

   1 /*
   2  * Linux Socket Filter Data Structures
   3  */
   4 #ifndef __LINUX_FILTER_H__
   5 #define __LINUX_FILTER_H__
   6
   7 #include <stdarg.h>
   8
   9 #include <linux/atomic.h>
  10 #include <linux/refcount.h>
  11 #include <linux/compat.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/linkage.h>
  14 #include <linux/printk.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/sched.h>
  17 #include <linux/capability.h>
  18 #include <linux/cryptohash.h>
  19
  20 #include <net/sch_generic.h>
  21
  22 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
  23 #include <asm/set_memory.h>
  24 #endif
  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
  34 /* ArgX, context and stack frame pointer register positions. Note,
  35  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  36  * calls in BPF_CALL instruction.
  37  */
  38 #define BPF_REG_ARG1    BPF_REG_1
  39 #define BPF_REG_ARG2    BPF_REG_2
  40 #define BPF_REG_ARG3    BPF_REG_3
  41 #define BPF_REG_ARG4    BPF_REG_4
  42 #define BPF_REG_ARG5    BPF_REG_5
  43 #define BPF_REG_CTX     BPF_REG_6
  44 #define BPF_REG_FP      BPF_REG_10
  45
  46 /* Additional register mappings for converted user programs. */
  47 #define BPF_REG_A       BPF_REG_0
  48 #define BPF_REG_X       BPF_REG_7
  49 #define BPF_REG_TMP     BPF_REG_8
  50
  51 /* Kernel hidden auxiliary/helper register for hardening step.
  52  * Only used by eBPF JITs. It's nothing more than a temporary
  53  * register that JITs use internally, only that here it's part
  54  * of eBPF instructions that have been rewritten for blinding
  55  * constants. See JIT pre-step in bpf_jit_blind_constants().
  56  */
  57 #define BPF_REG_AX              MAX_BPF_REG
  58 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
  59
  60 /* unused opcode to mark special call to bpf_tail_call() helper */
  61 #define BPF_TAIL_CALL   0xf0
  62
  63 /* As per nm, we expose JITed images as text (code) section for
  64  * kallsyms. That way, tools like perf can find it to match
  65  * addresses.
  66  */
  67 #define BPF_SYM_ELF_TYPE        't'
  68
  69 /* BPF program can access up to 512 bytes of stack space. */
  70 #define MAX_BPF_STACK   512
  71
  72 /* Helper macros for filter block array initializers. */
  73
  74 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  75
  76 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  77         ((struct bpf_insn) {                                    \
  78                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  79                 .dst_reg = DST,                                 \
  80                 .src_reg = SRC,                                 \
  81                 .off   = 0,                                     \
  82                 .imm   = 0 })
  83
  84 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  85         ((struct bpf_insn) {                                    \
  86                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  87                 .dst_reg = DST,                                 \
  88                 .src_reg = SRC,                                 \
  89                 .off   = 0,                                     \
  90                 .imm   = 0 })
  91
  92 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  93
  94 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  95         ((struct bpf_insn) {                                    \
  96                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  97                 .dst_reg = DST,                                 \
  98                 .src_reg = 0,                                   \
  99                 .off   = 0,                                     \
 100                 .imm   = IMM })
 101
 102 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
 103         ((struct bpf_insn) {                                    \
 104                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
 105                 .dst_reg = DST,                                 \
 106                 .src_reg = 0,                                   \
 107                 .off   = 0,                                     \
 108                 .imm   = IMM })
 109
 110 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
 111
 112 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
 113         ((struct bpf_insn) {                                    \
 114                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 115                 .dst_reg = DST,                                 \
 116                 .src_reg = 0,                                   \
 117                 .off   = 0,                                     \
 118                 .imm   = LEN })
 119
 120 /* Short form of mov, dst_reg = src_reg */
 121
 122 #define BPF_MOV64_REG(DST, SRC)                                 \
 123         ((struct bpf_insn) {                                    \
 124                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 125                 .dst_reg = DST,                                 \
 126                 .src_reg = SRC,                                 \
 127                 .off   = 0,                                     \
 128                 .imm   = 0 })
 129
 130 #define BPF_MOV32_REG(DST, SRC)                                 \
 131         ((struct bpf_insn) {                                    \
 132                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 133                 .dst_reg = DST,                                 \
 134                 .src_reg = SRC,                                 \
 135                 .off   = 0,                                     \
 136                 .imm   = 0 })
 137
 138 /* Short form of mov, dst_reg = imm32 */
 139
 140 #define BPF_MOV64_IMM(DST, IMM)                                 \
 141         ((struct bpf_insn) {                                    \
 142                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 143                 .dst_reg = DST,                                 \
 144                 .src_reg = 0,                                   \
 145                 .off   = 0,                                     \
 146                 .imm   = IMM })
 147
 148 #define BPF_MOV32_IMM(DST, IMM)                                 \
 149         ((struct bpf_insn) {                                    \
 150                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 151                 .dst_reg = DST,                                 \
 152                 .src_reg = 0,                                   \
 153                 .off   = 0,                                     \
 154                 .imm   = IMM })
 155
 156 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 157 #define BPF_LD_IMM64(DST, IMM)                                  \
 158         BPF_LD_IMM64_RAW(DST, 0, IMM)
 159
 160 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 161         ((struct bpf_insn) {                                    \
 162                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 163                 .dst_reg = DST,                                 \
 164                 .src_reg = SRC,                                 \
 165                 .off   = 0,                                     \
 166                 .imm   = (__u32) (IMM) }),                      \
 167         ((struct bpf_insn) {                                    \
 168                 .code  = 0, /* zero is reserved opcode */       \
 169                 .dst_reg = 0,                                   \
 170                 .src_reg = 0,                                   \
 171                 .off   = 0,                                     \
 172                 .imm   = ((__u64) (IMM)) >> 32 })
 173
 174 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 175 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 176         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 177
 178 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 179
 180 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 181         ((struct bpf_insn) {                                    \
 182                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 183                 .dst_reg = DST,                                 \
 184                 .src_reg = SRC,                                 \
 185                 .off   = 0,                                     \
 186                 .imm   = IMM })
 187
 188 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 189         ((struct bpf_insn) {                                    \
 190                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 191                 .dst_reg = DST,                                 \
 192                 .src_reg = SRC,                                 \
 193                 .off   = 0,                                     \
 194                 .imm   = IMM })
 195
 196 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 197
 198 #define BPF_LD_ABS(SIZE, IMM)                                   \
 199         ((struct bpf_insn) {                                    \
 200                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 201                 .dst_reg = 0,                                   \
 202                 .src_reg = 0,                                   \
 203                 .off   = 0,                                     \
 204                 .imm   = IMM })
 205
 206 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 207
 208 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 209         ((struct bpf_insn) {                                    \
 210                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 211                 .dst_reg = 0,                                   \
 212                 .src_reg = SRC,                                 \
 213                 .off   = 0,                                     \
 214                 .imm   = IMM })
 215
 216 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 217
 218 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 219         ((struct bpf_insn) {                                    \
 220                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 221                 .dst_reg = DST,                                 \
 222                 .src_reg = SRC,                                 \
 223                 .off   = OFF,                                   \
 224                 .imm   = 0 })
 225
 226 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 227
 228 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 229         ((struct bpf_insn) {                                    \
 230                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 231                 .dst_reg = DST,                                 \
 232                 .src_reg = SRC,                                 \
 233                 .off   = OFF,                                   \
 234                 .imm   = 0 })
 235
 236 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 237
 238 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 239         ((struct bpf_insn) {                                    \
 240                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 241                 .dst_reg = DST,                                 \
 242                 .src_reg = SRC,                                 \
 243                 .off   = OFF,                                   \
 244                 .imm   = 0 })
 245
 246 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 247
 248 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 249         ((struct bpf_insn) {                                    \
 250                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 251                 .dst_reg = DST,                                 \
 252                 .src_reg = 0,                                   \
 253                 .off   = OFF,                                   \
 254                 .imm   = IMM })
 255
 256 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 257
 258 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 259         ((struct bpf_insn) {                                    \
 260                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 261                 .dst_reg = DST,                                 \
 262                 .src_reg = SRC,                                 \
 263                 .off   = OFF,                                   \
 264                 .imm   = 0 })
 265
 266 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 267
 268 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 269         ((struct bpf_insn) {                                    \
 270                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 271                 .dst_reg = DST,                                 \
 272                 .src_reg = 0,                                   \
 273                 .off   = OFF,                                   \
 274                 .imm   = IMM })
 275
 276 /* Unconditional jumps, goto pc + off16 */
 277
 278 #define BPF_JMP_A(OFF)                                          \
 279         ((struct bpf_insn) {                                    \
 280                 .code  = BPF_JMP | BPF_JA,                      \
 281                 .dst_reg = 0,                                   \
 282                 .src_reg = 0,                                   \
 283                 .off   = OFF,                                   \
 284                 .imm   = 0 })
 285
 286 /* Function call */
 287
 288 #define BPF_EMIT_CALL(FUNC)                                     \
 289         ((struct bpf_insn) {                                    \
 290                 .code  = BPF_JMP | BPF_CALL,                    \
 291                 .dst_reg = 0,                                   \
 292                 .src_reg = 0,                                   \
 293                 .off   = 0,                                     \
 294                 .imm   = ((FUNC) - __bpf_call_base) })
 295
 296 /* Raw code statement block */
 297
 298 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 299         ((struct bpf_insn) {                                    \
 300                 .code  = CODE,                                  \
 301                 .dst_reg = DST,                                 \
 302                 .src_reg = SRC,                                 \
 303                 .off   = OFF,                                   \
 304                 .imm   = IMM })
 305
 306 /* Program exit */
 307
 308 #define BPF_EXIT_INSN()                                         \
 309         ((struct bpf_insn) {                                    \
 310                 .code  = BPF_JMP | BPF_EXIT,                    \
 311                 .dst_reg = 0,                                   \
 312                 .src_reg = 0,                                   \
 313                 .off   = 0,                                     \
 314                 .imm   = 0 })
 315
 316 /* Internal classic blocks for direct assignment */
 317
 318 #define __BPF_STMT(CODE, K)                                     \
 319         ((struct sock_filter) BPF_STMT(CODE, K))
 320
 321 #define __BPF_JUMP(CODE, K, JT, JF)                             \
 322         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 323
 324 #define bytes_to_bpf_size(bytes)                                \
 325 ({                                                              \
 326         int bpf_size = -EINVAL;                                 \
 327                                                                 \
 328         if (bytes == sizeof(u8))                                \
 329                 bpf_size = BPF_B;                               \
 330         else if (bytes == sizeof(u16))                          \
 331                 bpf_size = BPF_H;                               \
 332         else if (bytes == sizeof(u32))                          \
 333                 bpf_size = BPF_W;                               \
 334         else if (bytes == sizeof(u64))                          \
 335                 bpf_size = BPF_DW;                              \
 336                                                                 \
 337         bpf_size;                                               \
 338 })
 339
 340 #define bpf_size_to_bytes(bpf_size)                             \
 341 ({                                                              \
 342         int bytes = -EINVAL;                                    \
 343                                                                 \
 344         if (bpf_size == BPF_B)                                  \
 345                 bytes = sizeof(u8);                             \
 346         else if (bpf_size == BPF_H)                             \
 347                 bytes = sizeof(u16);                            \
 348         else if (bpf_size == BPF_W)                             \
 349                 bytes = sizeof(u32);                            \
 350         else if (bpf_size == BPF_DW)                            \
 351                 bytes = sizeof(u64);                            \
 352                                                                 \
 353         bytes;                                                  \
 354 })
 355
 356 #define BPF_SIZEOF(type)                                        \
 357         ({                                                      \
 358                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 359                 BUILD_BUG_ON(__size < 0);                       \
 360                 __size;                                         \
 361         })
 362
 363 #define BPF_FIELD_SIZEOF(type, field)                           \
 364         ({                                                      \
 365                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 366                 BUILD_BUG_ON(__size < 0);                       \
 367                 __size;                                         \
 368         })
 369
 370 #define BPF_LDST_BYTES(insn)                                    \
 371         ({                                                      \
 372                 const int __size = bpf_size_to_bytes(BPF_SIZE(insn->code)); \
 373                 WARN_ON(__size < 0);                            \
 374                 __size;                                         \
 375         })
 376
 377 #define __BPF_MAP_0(m, v, ...) v
 378 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 379 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 380 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 381 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 382 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 383
 384 #define __BPF_REG_0(...) __BPF_PAD(5)
 385 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 386 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 387 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 388 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 389 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 390
 391 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 392 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 393
 394 #define __BPF_CAST(t, a)                                                       \
 395         (__force t)                                                            \
 396         (__force                                                               \
 397          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 398                                       (unsigned long)0, (t)0))) a
 399 #define __BPF_V void
 400 #define __BPF_N
 401
 402 #define __BPF_DECL_ARGS(t, a) t   a
 403 #define __BPF_DECL_REGS(t, a) u64 a
 404
 405 #define __BPF_PAD(n)                                                           \
 406         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 407                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 408
 409 #define BPF_CALL_x(x, name, ...)                                               \
 410         static __always_inline                                                 \
 411         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 412         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 413         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 414         {                                                                      \
 415                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 416         }                                                                      \
 417         static __always_inline                                                 \
 418         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 419
 420 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 421 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 422 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 423 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 424 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 425 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 426
 427 #define bpf_ctx_range(TYPE, MEMBER)                                             \
 428         offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
 429 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)                              \
 430         offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
 431
 432 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)                            \
 433         ({                                                                      \
 434                 BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE));             \
 435                 *(PTR_SIZE) = (SIZE);                                           \
 436                 offsetof(TYPE, MEMBER);                                         \
 437         })
 438
 439 #ifdef CONFIG_COMPAT
 440 /* A struct sock_filter is architecture independent. */
 441 struct compat_sock_fprog {
 442         u16             len;
 443         compat_uptr_t   filter; /* struct sock_filter * */
 444 };
 445 #endif
 446
 447 struct sock_fprog_kern {
 448         u16                     len;
 449         struct sock_filter      *filter;
 450 };
 451
 452 struct bpf_binary_header {
 453         unsigned int pages;
 454         u8 image[];
 455 };
 456
 457 struct bpf_prog {
 458         u16                     pages;          /* Number of allocated pages */
 459         kmemcheck_bitfield_begin(meta);
 460         u16                     jited:1,        /* Is our filter JIT'ed? */
 461                                 locked:1,       /* Program image locked? */
 462                                 gpl_compatible:1, /* Is filter GPL compatible? */
 463                                 cb_access:1,    /* Is control block accessed? */
 464                                 dst_needed:1;   /* Do we need dst entry? */
 465         kmemcheck_bitfield_end(meta);
 466         enum bpf_prog_type      type;           /* Type of BPF program */
 467         u32                     len;            /* Number of filter blocks */
 468         u32                     jited_len;      /* Size of jited insns in bytes */
 469         u8                      tag[BPF_TAG_SIZE];
 470         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 471         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 472         unsigned int            (*bpf_func)(const void *ctx,
 473                                             const struct bpf_insn *insn);
 474         /* Instructions for interpreter */
 475         union {
 476                 struct sock_filter      insns[0];
 477                 struct bpf_insn         insnsi[0];
 478         };
 479 };
 480
 481 struct sk_filter {
 482         refcount_t      refcnt;
 483         struct rcu_head rcu;
 484         struct bpf_prog *prog;
 485 };
 486
 487 #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
 488
 489 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 490
 491 struct bpf_skb_data_end {
 492         struct qdisc_skb_cb qdisc_cb;
 493         void *data_end;
 494 };
 495
 496 struct xdp_buff {
 497         void *data;
 498         void *data_end;
 499         void *data_hard_start;
 500 };
 501
 502 /* compute the linear packet data range [data, data_end) which
 503  * will be accessed by cls_bpf, act_bpf and lwt programs
 504  */
 505 static inline void bpf_compute_data_end(struct sk_buff *skb)
 506 {
 507         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 508
 509         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 510         cb->data_end = skb->data + skb_headlen(skb);
 511 }
 512
 513 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 514 {
 515         /* eBPF programs may read/write skb->cb[] area to transfer meta
 516          * data between tail calls. Since this also needs to work with
 517          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 518          *
 519          * In some socket filter cases, the cb unfortunately needs to be
 520          * saved/restored so that protocol specific skb->cb[] data won't
 521          * be lost. In any case, due to unpriviledged eBPF programs
 522          * attached to sockets, we need to clear the bpf_skb_cb() area
 523          * to not leak previous contents to user space.
 524          */
 525         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 526         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 527                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
 528
 529         return qdisc_skb_cb(skb)->data;
 530 }
 531
 532 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 533                                        struct sk_buff *skb)
 534 {
 535         u8 *cb_data = bpf_skb_cb(skb);
 536         u8 cb_saved[BPF_SKB_CB_LEN];
 537         u32 res;
 538
 539         if (unlikely(prog->cb_access)) {
 540                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 541                 memset(cb_data, 0, sizeof(cb_saved));
 542         }
 543
 544         res = BPF_PROG_RUN(prog, skb);
 545
 546         if (unlikely(prog->cb_access))
 547                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 548
 549         return res;
 550 }
 551
 552 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 553                                         struct sk_buff *skb)
 554 {
 555         u8 *cb_data = bpf_skb_cb(skb);
 556
 557         if (unlikely(prog->cb_access))
 558                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 559
 560         return BPF_PROG_RUN(prog, skb);
 561 }
 562
 563 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 564                                             struct xdp_buff *xdp)
 565 {
 566         /* Caller needs to hold rcu_read_lock() (!), otherwise program
 567          * can be released while still running, or map elements could be
 568          * freed early while still having concurrent users. XDP fastpath
 569          * already takes rcu_read_lock() when fetching the program, so
 570          * it's not necessary here anymore.
 571          */
 572         return BPF_PROG_RUN(prog, xdp);
 573 }
 574
 575 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 576 {
 577         return prog->len * sizeof(struct bpf_insn);
 578 }
 579
 580 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 581 {
 582         return round_up(bpf_prog_insn_size(prog) +
 583                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 584 }
 585
 586 static inline unsigned int bpf_prog_size(unsigned int proglen)
 587 {
 588         return max(sizeof(struct bpf_prog),
 589                    offsetof(struct bpf_prog, insns[proglen]));
 590 }
 591
 592 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 593 {
 594         /* When classic BPF programs have been loaded and the arch
 595          * does not have a classic BPF JIT (anymore), they have been
 596          * converted via bpf_migrate_filter() to eBPF and thus always
 597          * have an unspec program type.
 598          */
 599         return prog->type == BPF_PROG_TYPE_UNSPEC;
 600 }
 601
 602 static inline bool
 603 bpf_ctx_narrow_access_ok(u32 off, u32 size, const u32 size_default)
 604 {
 605         bool off_ok;
 606 #ifdef __LITTLE_ENDIAN
 607         off_ok = (off & (size_default - 1)) == 0;
 608 #else
 609         off_ok = (off & (size_default - 1)) + size == size_default;
 610 #endif
 611         return off_ok && size <= size_default && (size & (size - 1)) == 0;
 612 }
 613
 614 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 615
 616 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
 617 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 618 {
 619         fp->locked = 1;
 620         WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
 621 }
 622
 623 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 624 {
 625         if (fp->locked) {
 626                 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
 627                 /* In case set_memory_rw() fails, we want to be the first
 628                  * to crash here instead of some random place later on.
 629                  */
 630                 fp->locked = 0;
 631         }
 632 }
 633
 634 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 635 {
 636         WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
 637 }
 638
 639 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 640 {
 641         WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
 642 }
 643 #else
 644 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 645 {
 646 }
 647
 648 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 649 {
 650 }
 651
 652 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 653 {
 654 }
 655
 656 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 657 {
 658 }
 659 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 660
 661 static inline struct bpf_binary_header *
 662 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 663 {
 664         unsigned long real_start = (unsigned long)fp->bpf_func;
 665         unsigned long addr = real_start & PAGE_MASK;
 666
 667         return (void *)addr;
 668 }
 669
 670 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 671 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 672 {
 673         return sk_filter_trim_cap(sk, skb, 1);
 674 }
 675
 676 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 677 void bpf_prog_free(struct bpf_prog *fp);
 678
 679 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 680 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 681                                   gfp_t gfp_extra_flags);
 682 void __bpf_prog_free(struct bpf_prog *fp);
 683
 684 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 685 {
 686         bpf_prog_unlock_ro(fp);
 687         __bpf_prog_free(fp);
 688 }
 689
 690 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 691                                        unsigned int flen);
 692
 693 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 694 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 695                               bpf_aux_classic_check_t trans, bool save_orig);
 696 void bpf_prog_destroy(struct bpf_prog *fp);
 697
 698 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 699 int sk_attach_bpf(u32 ufd, struct sock *sk);
 700 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 701 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 702 int sk_detach_filter(struct sock *sk);
 703 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 704                   unsigned int len);
 705
 706 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 707 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 708
 709 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 710
 711 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 712 void bpf_jit_compile(struct bpf_prog *prog);
 713 bool bpf_helper_changes_pkt_data(void *func);
 714
 715 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 716                                        const struct bpf_insn *patch, u32 len);
 717 void bpf_warn_invalid_xdp_action(u32 act);
 718
 719 #ifdef CONFIG_BPF_JIT
 720 extern int bpf_jit_enable;
 721 extern int bpf_jit_harden;
 722 extern int bpf_jit_kallsyms;
 723
 724 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 725
 726 struct bpf_binary_header *
 727 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 728                      unsigned int alignment,
 729                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
 730 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 731
 732 void bpf_jit_free(struct bpf_prog *fp);
 733
 734 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 735 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 736
 737 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 738                                 u32 pass, void *image)
 739 {
 740         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 741                proglen, pass, image, current->comm, task_pid_nr(current));
 742
 743         if (image)
 744                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 745                                16, 1, image, proglen, false);
 746 }
 747
 748 static inline bool bpf_jit_is_ebpf(void)
 749 {
 750 # ifdef CONFIG_HAVE_EBPF_JIT
 751         return true;
 752 # else
 753         return false;
 754 # endif
 755 }
 756
 757 static inline bool ebpf_jit_enabled(void)
 758 {
 759         return bpf_jit_enable && bpf_jit_is_ebpf();
 760 }
 761
 762 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 763 {
 764         return fp->jited && bpf_jit_is_ebpf();
 765 }
 766
 767 static inline bool bpf_jit_blinding_enabled(void)
 768 {
 769         /* These are the prerequisites, should someone ever have the
 770          * idea to call blinding outside of them, we make sure to
 771          * bail out.
 772          */
 773         if (!bpf_jit_is_ebpf())
 774                 return false;
 775         if (!bpf_jit_enable)
 776                 return false;
 777         if (!bpf_jit_harden)
 778                 return false;
 779         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 780                 return false;
 781
 782         return true;
 783 }
 784
 785 static inline bool bpf_jit_kallsyms_enabled(void)
 786 {
 787         /* There are a couple of corner cases where kallsyms should
 788          * not be enabled f.e. on hardening.
 789          */
 790         if (bpf_jit_harden)
 791                 return false;
 792         if (!bpf_jit_kallsyms)
 793                 return false;
 794         if (bpf_jit_kallsyms == 1)
 795                 return true;
 796
 797         return false;
 798 }
 799
 800 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 801                                  unsigned long *off, char *sym);
 802 bool is_bpf_text_address(unsigned long addr);
 803 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 804                     char *sym);
 805
 806 static inline const char *
 807 bpf_address_lookup(unsigned long addr, unsigned long *size,
 808                    unsigned long *off, char **modname, char *sym)
 809 {
 810         const char *ret = __bpf_address_lookup(addr, size, off, sym);
 811
 812         if (ret && modname)
 813                 *modname = NULL;
 814         return ret;
 815 }
 816
 817 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 818 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
 819
 820 #else /* CONFIG_BPF_JIT */
 821
 822 static inline bool ebpf_jit_enabled(void)
 823 {
 824         return false;
 825 }
 826
 827 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 828 {
 829         return false;
 830 }
 831
 832 static inline void bpf_jit_free(struct bpf_prog *fp)
 833 {
 834         bpf_prog_unlock_free(fp);
 835 }
 836
 837 static inline bool bpf_jit_kallsyms_enabled(void)
 838 {
 839         return false;
 840 }
 841
 842 static inline const char *
 843 __bpf_address_lookup(unsigned long addr, unsigned long *size,
 844                      unsigned long *off, char *sym)
 845 {
 846         return NULL;
 847 }
 848
 849 static inline bool is_bpf_text_address(unsigned long addr)
 850 {
 851         return false;
 852 }
 853
 854 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
 855                                   char *type, char *sym)
 856 {
 857         return -ERANGE;
 858 }
 859
 860 static inline const char *
 861 bpf_address_lookup(unsigned long addr, unsigned long *size,
 862                    unsigned long *off, char **modname, char *sym)
 863 {
 864         return NULL;
 865 }
 866
 867 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 868 {
 869 }
 870
 871 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 872 {
 873 }
 874 #endif /* CONFIG_BPF_JIT */
 875
 876 #define BPF_ANC         BIT(15)
 877
 878 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
 879 {
 880         switch (first->code) {
 881         case BPF_RET | BPF_K:
 882         case BPF_LD | BPF_W | BPF_LEN:
 883                 return false;
 884
 885         case BPF_LD | BPF_W | BPF_ABS:
 886         case BPF_LD | BPF_H | BPF_ABS:
 887         case BPF_LD | BPF_B | BPF_ABS:
 888                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
 889                         return true;
 890                 return false;
 891
 892         default:
 893                 return true;
 894         }
 895 }
 896
 897 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 898 {
 899         BUG_ON(ftest->code & BPF_ANC);
 900
 901         switch (ftest->code) {
 902         case BPF_LD | BPF_W | BPF_ABS:
 903         case BPF_LD | BPF_H | BPF_ABS:
 904         case BPF_LD | BPF_B | BPF_ABS:
 905 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
 906                                 return BPF_ANC | SKF_AD_##CODE
 907                 switch (ftest->k) {
 908                 BPF_ANCILLARY(PROTOCOL);
 909                 BPF_ANCILLARY(PKTTYPE);
 910                 BPF_ANCILLARY(IFINDEX);
 911                 BPF_ANCILLARY(NLATTR);
 912                 BPF_ANCILLARY(NLATTR_NEST);
 913                 BPF_ANCILLARY(MARK);
 914                 BPF_ANCILLARY(QUEUE);
 915                 BPF_ANCILLARY(HATYPE);
 916                 BPF_ANCILLARY(RXHASH);
 917                 BPF_ANCILLARY(CPU);
 918                 BPF_ANCILLARY(ALU_XOR_X);
 919                 BPF_ANCILLARY(VLAN_TAG);
 920                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
 921                 BPF_ANCILLARY(PAY_OFFSET);
 922                 BPF_ANCILLARY(RANDOM);
 923                 BPF_ANCILLARY(VLAN_TPID);
 924                 }
 925                 /* Fallthrough. */
 926         default:
 927                 return ftest->code;
 928         }
 929 }
 930
 931 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 932                                            int k, unsigned int size);
 933
 934 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
 935                                      unsigned int size, void *buffer)
 936 {
 937         if (k >= 0)
 938                 return skb_header_pointer(skb, k, size, buffer);
 939
 940         return bpf_internal_load_pointer_neg_helper(skb, k, size);
 941 }
 942
 943 static inline int bpf_tell_extensions(void)
 944 {
 945         return SKF_AD_MAX;
 946 }
 947
 948 struct bpf_sock_ops_kern {
 949         struct  sock *sk;
 950         u32     op;
 951         union {
 952                 u32 reply;
 953                 u32 replylong[4];
 954         };
 955 };
 956
 957 #endif /* __LINUX_FILTER_H__ */