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_SIZEOF(type)                                        \
 341         ({                                                      \
 342                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 343                 BUILD_BUG_ON(__size < 0);                       \
 344                 __size;                                         \
 345         })
 346
 347 #define BPF_FIELD_SIZEOF(type, field)                           \
 348         ({                                                      \
 349                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 350                 BUILD_BUG_ON(__size < 0);                       \
 351                 __size;                                         \
 352         })
 353
 354 #define __BPF_MAP_0(m, v, ...) v
 355 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 356 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 357 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 358 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 359 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 360
 361 #define __BPF_REG_0(...) __BPF_PAD(5)
 362 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 363 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 364 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 365 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 366 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 367
 368 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 369 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 370
 371 #define __BPF_CAST(t, a)                                                       \
 372         (__force t)                                                            \
 373         (__force                                                               \
 374          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 375                                       (unsigned long)0, (t)0))) a
 376 #define __BPF_V void
 377 #define __BPF_N
 378
 379 #define __BPF_DECL_ARGS(t, a) t   a
 380 #define __BPF_DECL_REGS(t, a) u64 a
 381
 382 #define __BPF_PAD(n)                                                           \
 383         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 384                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 385
 386 #define BPF_CALL_x(x, name, ...)                                               \
 387         static __always_inline                                                 \
 388         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 389         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 390         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 391         {                                                                      \
 392                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 393         }                                                                      \
 394         static __always_inline                                                 \
 395         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 396
 397 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 398 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 399 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 400 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 401 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 402 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 403
 404 #ifdef CONFIG_COMPAT
 405 /* A struct sock_filter is architecture independent. */
 406 struct compat_sock_fprog {
 407         u16             len;
 408         compat_uptr_t   filter; /* struct sock_filter * */
 409 };
 410 #endif
 411
 412 struct sock_fprog_kern {
 413         u16                     len;
 414         struct sock_filter      *filter;
 415 };
 416
 417 struct bpf_binary_header {
 418         unsigned int pages;
 419         u8 image[];
 420 };
 421
 422 struct bpf_prog {
 423         u16                     pages;          /* Number of allocated pages */
 424         kmemcheck_bitfield_begin(meta);
 425         u16                     jited:1,        /* Is our filter JIT'ed? */
 426                                 locked:1,       /* Program image locked? */
 427                                 gpl_compatible:1, /* Is filter GPL compatible? */
 428                                 cb_access:1,    /* Is control block accessed? */
 429                                 dst_needed:1;   /* Do we need dst entry? */
 430         kmemcheck_bitfield_end(meta);
 431         enum bpf_prog_type      type;           /* Type of BPF program */
 432         u32                     len;            /* Number of filter blocks */
 433         u32                     jited_len;      /* Size of jited insns in bytes */
 434         u8                      tag[BPF_TAG_SIZE];
 435         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 436         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 437         unsigned int            (*bpf_func)(const void *ctx,
 438                                             const struct bpf_insn *insn);
 439         /* Instructions for interpreter */
 440         union {
 441                 struct sock_filter      insns[0];
 442                 struct bpf_insn         insnsi[0];
 443         };
 444 };
 445
 446 struct sk_filter {
 447         refcount_t      refcnt;
 448         struct rcu_head rcu;
 449         struct bpf_prog *prog;
 450 };
 451
 452 #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
 453
 454 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 455
 456 struct bpf_skb_data_end {
 457         struct qdisc_skb_cb qdisc_cb;
 458         void *data_end;
 459 };
 460
 461 struct xdp_buff {
 462         void *data;
 463         void *data_end;
 464         void *data_hard_start;
 465 };
 466
 467 /* compute the linear packet data range [data, data_end) which
 468  * will be accessed by cls_bpf, act_bpf and lwt programs
 469  */
 470 static inline void bpf_compute_data_end(struct sk_buff *skb)
 471 {
 472         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 473
 474         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 475         cb->data_end = skb->data + skb_headlen(skb);
 476 }
 477
 478 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 479 {
 480         /* eBPF programs may read/write skb->cb[] area to transfer meta
 481          * data between tail calls. Since this also needs to work with
 482          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 483          *
 484          * In some socket filter cases, the cb unfortunately needs to be
 485          * saved/restored so that protocol specific skb->cb[] data won't
 486          * be lost. In any case, due to unpriviledged eBPF programs
 487          * attached to sockets, we need to clear the bpf_skb_cb() area
 488          * to not leak previous contents to user space.
 489          */
 490         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 491         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 492                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
 493
 494         return qdisc_skb_cb(skb)->data;
 495 }
 496
 497 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 498                                        struct sk_buff *skb)
 499 {
 500         u8 *cb_data = bpf_skb_cb(skb);
 501         u8 cb_saved[BPF_SKB_CB_LEN];
 502         u32 res;
 503
 504         if (unlikely(prog->cb_access)) {
 505                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 506                 memset(cb_data, 0, sizeof(cb_saved));
 507         }
 508
 509         res = BPF_PROG_RUN(prog, skb);
 510
 511         if (unlikely(prog->cb_access))
 512                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 513
 514         return res;
 515 }
 516
 517 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 518                                         struct sk_buff *skb)
 519 {
 520         u8 *cb_data = bpf_skb_cb(skb);
 521
 522         if (unlikely(prog->cb_access))
 523                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 524
 525         return BPF_PROG_RUN(prog, skb);
 526 }
 527
 528 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 529                                             struct xdp_buff *xdp)
 530 {
 531         /* Caller needs to hold rcu_read_lock() (!), otherwise program
 532          * can be released while still running, or map elements could be
 533          * freed early while still having concurrent users. XDP fastpath
 534          * already takes rcu_read_lock() when fetching the program, so
 535          * it's not necessary here anymore.
 536          */
 537         return BPF_PROG_RUN(prog, xdp);
 538 }
 539
 540 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 541 {
 542         return prog->len * sizeof(struct bpf_insn);
 543 }
 544
 545 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 546 {
 547         return round_up(bpf_prog_insn_size(prog) +
 548                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 549 }
 550
 551 static inline unsigned int bpf_prog_size(unsigned int proglen)
 552 {
 553         return max(sizeof(struct bpf_prog),
 554                    offsetof(struct bpf_prog, insns[proglen]));
 555 }
 556
 557 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 558 {
 559         /* When classic BPF programs have been loaded and the arch
 560          * does not have a classic BPF JIT (anymore), they have been
 561          * converted via bpf_migrate_filter() to eBPF and thus always
 562          * have an unspec program type.
 563          */
 564         return prog->type == BPF_PROG_TYPE_UNSPEC;
 565 }
 566
 567 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 568
 569 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
 570 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 571 {
 572         fp->locked = 1;
 573         WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
 574 }
 575
 576 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 577 {
 578         if (fp->locked) {
 579                 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
 580                 /* In case set_memory_rw() fails, we want to be the first
 581                  * to crash here instead of some random place later on.
 582                  */
 583                 fp->locked = 0;
 584         }
 585 }
 586
 587 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 588 {
 589         WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
 590 }
 591
 592 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 593 {
 594         WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
 595 }
 596 #else
 597 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 598 {
 599 }
 600
 601 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 602 {
 603 }
 604
 605 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 606 {
 607 }
 608
 609 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 610 {
 611 }
 612 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 613
 614 static inline struct bpf_binary_header *
 615 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 616 {
 617         unsigned long real_start = (unsigned long)fp->bpf_func;
 618         unsigned long addr = real_start & PAGE_MASK;
 619
 620         return (void *)addr;
 621 }
 622
 623 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 624 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 625 {
 626         return sk_filter_trim_cap(sk, skb, 1);
 627 }
 628
 629 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 630 void bpf_prog_free(struct bpf_prog *fp);
 631
 632 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 633 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 634                                   gfp_t gfp_extra_flags);
 635 void __bpf_prog_free(struct bpf_prog *fp);
 636
 637 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 638 {
 639         bpf_prog_unlock_ro(fp);
 640         __bpf_prog_free(fp);
 641 }
 642
 643 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 644                                        unsigned int flen);
 645
 646 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 647 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 648                               bpf_aux_classic_check_t trans, bool save_orig);
 649 void bpf_prog_destroy(struct bpf_prog *fp);
 650
 651 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 652 int sk_attach_bpf(u32 ufd, struct sock *sk);
 653 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 654 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 655 int sk_detach_filter(struct sock *sk);
 656 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 657                   unsigned int len);
 658
 659 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 660 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 661
 662 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 663
 664 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 665 void bpf_jit_compile(struct bpf_prog *prog);
 666 bool bpf_helper_changes_pkt_data(void *func);
 667
 668 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 669                                        const struct bpf_insn *patch, u32 len);
 670 void bpf_warn_invalid_xdp_action(u32 act);
 671
 672 #ifdef CONFIG_BPF_JIT
 673 extern int bpf_jit_enable;
 674 extern int bpf_jit_harden;
 675 extern int bpf_jit_kallsyms;
 676
 677 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 678
 679 struct bpf_binary_header *
 680 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 681                      unsigned int alignment,
 682                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
 683 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 684
 685 void bpf_jit_free(struct bpf_prog *fp);
 686
 687 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 688 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 689
 690 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 691                                 u32 pass, void *image)
 692 {
 693         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 694                proglen, pass, image, current->comm, task_pid_nr(current));
 695
 696         if (image)
 697                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 698                                16, 1, image, proglen, false);
 699 }
 700
 701 static inline bool bpf_jit_is_ebpf(void)
 702 {
 703 # ifdef CONFIG_HAVE_EBPF_JIT
 704         return true;
 705 # else
 706         return false;
 707 # endif
 708 }
 709
 710 static inline bool ebpf_jit_enabled(void)
 711 {
 712         return bpf_jit_enable && bpf_jit_is_ebpf();
 713 }
 714
 715 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 716 {
 717         return fp->jited && bpf_jit_is_ebpf();
 718 }
 719
 720 static inline bool bpf_jit_blinding_enabled(void)
 721 {
 722         /* These are the prerequisites, should someone ever have the
 723          * idea to call blinding outside of them, we make sure to
 724          * bail out.
 725          */
 726         if (!bpf_jit_is_ebpf())
 727                 return false;
 728         if (!bpf_jit_enable)
 729                 return false;
 730         if (!bpf_jit_harden)
 731                 return false;
 732         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 733                 return false;
 734
 735         return true;
 736 }
 737
 738 static inline bool bpf_jit_kallsyms_enabled(void)
 739 {
 740         /* There are a couple of corner cases where kallsyms should
 741          * not be enabled f.e. on hardening.
 742          */
 743         if (bpf_jit_harden)
 744                 return false;
 745         if (!bpf_jit_kallsyms)
 746                 return false;
 747         if (bpf_jit_kallsyms == 1)
 748                 return true;
 749
 750         return false;
 751 }
 752
 753 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 754                                  unsigned long *off, char *sym);
 755 bool is_bpf_text_address(unsigned long addr);
 756 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 757                     char *sym);
 758
 759 static inline const char *
 760 bpf_address_lookup(unsigned long addr, unsigned long *size,
 761                    unsigned long *off, char **modname, char *sym)
 762 {
 763         const char *ret = __bpf_address_lookup(addr, size, off, sym);
 764
 765         if (ret && modname)
 766                 *modname = NULL;
 767         return ret;
 768 }
 769
 770 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 771 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
 772
 773 #else /* CONFIG_BPF_JIT */
 774
 775 static inline bool ebpf_jit_enabled(void)
 776 {
 777         return false;
 778 }
 779
 780 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 781 {
 782         return false;
 783 }
 784
 785 static inline void bpf_jit_free(struct bpf_prog *fp)
 786 {
 787         bpf_prog_unlock_free(fp);
 788 }
 789
 790 static inline bool bpf_jit_kallsyms_enabled(void)
 791 {
 792         return false;
 793 }
 794
 795 static inline const char *
 796 __bpf_address_lookup(unsigned long addr, unsigned long *size,
 797                      unsigned long *off, char *sym)
 798 {
 799         return NULL;
 800 }
 801
 802 static inline bool is_bpf_text_address(unsigned long addr)
 803 {
 804         return false;
 805 }
 806
 807 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
 808                                   char *type, char *sym)
 809 {
 810         return -ERANGE;
 811 }
 812
 813 static inline const char *
 814 bpf_address_lookup(unsigned long addr, unsigned long *size,
 815                    unsigned long *off, char **modname, char *sym)
 816 {
 817         return NULL;
 818 }
 819
 820 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 821 {
 822 }
 823
 824 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 825 {
 826 }
 827 #endif /* CONFIG_BPF_JIT */
 828
 829 #define BPF_ANC         BIT(15)
 830
 831 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
 832 {
 833         switch (first->code) {
 834         case BPF_RET | BPF_K:
 835         case BPF_LD | BPF_W | BPF_LEN:
 836                 return false;
 837
 838         case BPF_LD | BPF_W | BPF_ABS:
 839         case BPF_LD | BPF_H | BPF_ABS:
 840         case BPF_LD | BPF_B | BPF_ABS:
 841                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
 842                         return true;
 843                 return false;
 844
 845         default:
 846                 return true;
 847         }
 848 }
 849
 850 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 851 {
 852         BUG_ON(ftest->code & BPF_ANC);
 853
 854         switch (ftest->code) {
 855         case BPF_LD | BPF_W | BPF_ABS:
 856         case BPF_LD | BPF_H | BPF_ABS:
 857         case BPF_LD | BPF_B | BPF_ABS:
 858 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
 859                                 return BPF_ANC | SKF_AD_##CODE
 860                 switch (ftest->k) {
 861                 BPF_ANCILLARY(PROTOCOL);
 862                 BPF_ANCILLARY(PKTTYPE);
 863                 BPF_ANCILLARY(IFINDEX);
 864                 BPF_ANCILLARY(NLATTR);
 865                 BPF_ANCILLARY(NLATTR_NEST);
 866                 BPF_ANCILLARY(MARK);
 867                 BPF_ANCILLARY(QUEUE);
 868                 BPF_ANCILLARY(HATYPE);
 869                 BPF_ANCILLARY(RXHASH);
 870                 BPF_ANCILLARY(CPU);
 871                 BPF_ANCILLARY(ALU_XOR_X);
 872                 BPF_ANCILLARY(VLAN_TAG);
 873                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
 874                 BPF_ANCILLARY(PAY_OFFSET);
 875                 BPF_ANCILLARY(RANDOM);
 876                 BPF_ANCILLARY(VLAN_TPID);
 877                 }
 878                 /* Fallthrough. */
 879         default:
 880                 return ftest->code;
 881         }
 882 }
 883
 884 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 885                                            int k, unsigned int size);
 886
 887 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
 888                                      unsigned int size, void *buffer)
 889 {
 890         if (k >= 0)
 891                 return skb_header_pointer(skb, k, size, buffer);
 892
 893         return bpf_internal_load_pointer_neg_helper(skb, k, size);
 894 }
 895
 896 static inline int bpf_tell_extensions(void)
 897 {
 898         return SKF_AD_MAX;
 899 }
 900
 901 #endif /* __LINUX_FILTER_H__ */