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/compat.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/linkage.h>
  13 #include <linux/printk.h>
  14 #include <linux/workqueue.h>
  15 #include <linux/sched.h>
  16 #include <linux/capability.h>
  17 #include <linux/cryptohash.h>
  18
  19 #include <net/sch_generic.h>
  20
  21 #include <asm/cacheflush.h>
  22
  23 #include <uapi/linux/filter.h>
  24 #include <uapi/linux/bpf.h>
  25
  26 struct sk_buff;
  27 struct sock;
  28 struct seccomp_data;
  29 struct bpf_prog_aux;
  30
  31 /* ArgX, context and stack frame pointer register positions. Note,
  32  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  33  * calls in BPF_CALL instruction.
  34  */
  35 #define BPF_REG_ARG1    BPF_REG_1
  36 #define BPF_REG_ARG2    BPF_REG_2
  37 #define BPF_REG_ARG3    BPF_REG_3
  38 #define BPF_REG_ARG4    BPF_REG_4
  39 #define BPF_REG_ARG5    BPF_REG_5
  40 #define BPF_REG_CTX     BPF_REG_6
  41 #define BPF_REG_FP      BPF_REG_10
  42
  43 /* Additional register mappings for converted user programs. */
  44 #define BPF_REG_A       BPF_REG_0
  45 #define BPF_REG_X       BPF_REG_7
  46 #define BPF_REG_TMP     BPF_REG_8
  47
  48 /* Kernel hidden auxiliary/helper register for hardening step.
  49  * Only used by eBPF JITs. It's nothing more than a temporary
  50  * register that JITs use internally, only that here it's part
  51  * of eBPF instructions that have been rewritten for blinding
  52  * constants. See JIT pre-step in bpf_jit_blind_constants().
  53  */
  54 #define BPF_REG_AX              MAX_BPF_REG
  55 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
  56
  57 /* BPF program can access up to 512 bytes of stack space. */
  58 #define MAX_BPF_STACK   512
  59
  60 /* Helper macros for filter block array initializers. */
  61
  62 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  63
  64 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  65         ((struct bpf_insn) {                                    \
  66                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  67                 .dst_reg = DST,                                 \
  68                 .src_reg = SRC,                                 \
  69                 .off   = 0,                                     \
  70                 .imm   = 0 })
  71
  72 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  73         ((struct bpf_insn) {                                    \
  74                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  75                 .dst_reg = DST,                                 \
  76                 .src_reg = SRC,                                 \
  77                 .off   = 0,                                     \
  78                 .imm   = 0 })
  79
  80 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  81
  82 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  83         ((struct bpf_insn) {                                    \
  84                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  85                 .dst_reg = DST,                                 \
  86                 .src_reg = 0,                                   \
  87                 .off   = 0,                                     \
  88                 .imm   = IMM })
  89
  90 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  91         ((struct bpf_insn) {                                    \
  92                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  93                 .dst_reg = DST,                                 \
  94                 .src_reg = 0,                                   \
  95                 .off   = 0,                                     \
  96                 .imm   = IMM })
  97
  98 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
  99
 100 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
 101         ((struct bpf_insn) {                                    \
 102                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 103                 .dst_reg = DST,                                 \
 104                 .src_reg = 0,                                   \
 105                 .off   = 0,                                     \
 106                 .imm   = LEN })
 107
 108 /* Short form of mov, dst_reg = src_reg */
 109
 110 #define BPF_MOV64_REG(DST, SRC)                                 \
 111         ((struct bpf_insn) {                                    \
 112                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 113                 .dst_reg = DST,                                 \
 114                 .src_reg = SRC,                                 \
 115                 .off   = 0,                                     \
 116                 .imm   = 0 })
 117
 118 #define BPF_MOV32_REG(DST, SRC)                                 \
 119         ((struct bpf_insn) {                                    \
 120                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 121                 .dst_reg = DST,                                 \
 122                 .src_reg = SRC,                                 \
 123                 .off   = 0,                                     \
 124                 .imm   = 0 })
 125
 126 /* Short form of mov, dst_reg = imm32 */
 127
 128 #define BPF_MOV64_IMM(DST, IMM)                                 \
 129         ((struct bpf_insn) {                                    \
 130                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 131                 .dst_reg = DST,                                 \
 132                 .src_reg = 0,                                   \
 133                 .off   = 0,                                     \
 134                 .imm   = IMM })
 135
 136 #define BPF_MOV32_IMM(DST, IMM)                                 \
 137         ((struct bpf_insn) {                                    \
 138                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 139                 .dst_reg = DST,                                 \
 140                 .src_reg = 0,                                   \
 141                 .off   = 0,                                     \
 142                 .imm   = IMM })
 143
 144 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 145 #define BPF_LD_IMM64(DST, IMM)                                  \
 146         BPF_LD_IMM64_RAW(DST, 0, IMM)
 147
 148 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 149         ((struct bpf_insn) {                                    \
 150                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 151                 .dst_reg = DST,                                 \
 152                 .src_reg = SRC,                                 \
 153                 .off   = 0,                                     \
 154                 .imm   = (__u32) (IMM) }),                      \
 155         ((struct bpf_insn) {                                    \
 156                 .code  = 0, /* zero is reserved opcode */       \
 157                 .dst_reg = 0,                                   \
 158                 .src_reg = 0,                                   \
 159                 .off   = 0,                                     \
 160                 .imm   = ((__u64) (IMM)) >> 32 })
 161
 162 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 163 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 164         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 165
 166 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 167
 168 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 169         ((struct bpf_insn) {                                    \
 170                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 171                 .dst_reg = DST,                                 \
 172                 .src_reg = SRC,                                 \
 173                 .off   = 0,                                     \
 174                 .imm   = IMM })
 175
 176 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 177         ((struct bpf_insn) {                                    \
 178                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 179                 .dst_reg = DST,                                 \
 180                 .src_reg = SRC,                                 \
 181                 .off   = 0,                                     \
 182                 .imm   = IMM })
 183
 184 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 185
 186 #define BPF_LD_ABS(SIZE, IMM)                                   \
 187         ((struct bpf_insn) {                                    \
 188                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 189                 .dst_reg = 0,                                   \
 190                 .src_reg = 0,                                   \
 191                 .off   = 0,                                     \
 192                 .imm   = IMM })
 193
 194 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 195
 196 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 197         ((struct bpf_insn) {                                    \
 198                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 199                 .dst_reg = 0,                                   \
 200                 .src_reg = SRC,                                 \
 201                 .off   = 0,                                     \
 202                 .imm   = IMM })
 203
 204 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 205
 206 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 207         ((struct bpf_insn) {                                    \
 208                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 209                 .dst_reg = DST,                                 \
 210                 .src_reg = SRC,                                 \
 211                 .off   = OFF,                                   \
 212                 .imm   = 0 })
 213
 214 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 215
 216 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 217         ((struct bpf_insn) {                                    \
 218                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 219                 .dst_reg = DST,                                 \
 220                 .src_reg = SRC,                                 \
 221                 .off   = OFF,                                   \
 222                 .imm   = 0 })
 223
 224 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 225
 226 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 227         ((struct bpf_insn) {                                    \
 228                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 229                 .dst_reg = DST,                                 \
 230                 .src_reg = SRC,                                 \
 231                 .off   = OFF,                                   \
 232                 .imm   = 0 })
 233
 234 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 235
 236 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 237         ((struct bpf_insn) {                                    \
 238                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 239                 .dst_reg = DST,                                 \
 240                 .src_reg = 0,                                   \
 241                 .off   = OFF,                                   \
 242                 .imm   = IMM })
 243
 244 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 245
 246 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 247         ((struct bpf_insn) {                                    \
 248                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 249                 .dst_reg = DST,                                 \
 250                 .src_reg = SRC,                                 \
 251                 .off   = OFF,                                   \
 252                 .imm   = 0 })
 253
 254 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 255
 256 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 257         ((struct bpf_insn) {                                    \
 258                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 259                 .dst_reg = DST,                                 \
 260                 .src_reg = 0,                                   \
 261                 .off   = OFF,                                   \
 262                 .imm   = IMM })
 263
 264 /* Function call */
 265
 266 #define BPF_EMIT_CALL(FUNC)                                     \
 267         ((struct bpf_insn) {                                    \
 268                 .code  = BPF_JMP | BPF_CALL,                    \
 269                 .dst_reg = 0,                                   \
 270                 .src_reg = 0,                                   \
 271                 .off   = 0,                                     \
 272                 .imm   = ((FUNC) - __bpf_call_base) })
 273
 274 /* Raw code statement block */
 275
 276 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 277         ((struct bpf_insn) {                                    \
 278                 .code  = CODE,                                  \
 279                 .dst_reg = DST,                                 \
 280                 .src_reg = SRC,                                 \
 281                 .off   = OFF,                                   \
 282                 .imm   = IMM })
 283
 284 /* Program exit */
 285
 286 #define BPF_EXIT_INSN()                                         \
 287         ((struct bpf_insn) {                                    \
 288                 .code  = BPF_JMP | BPF_EXIT,                    \
 289                 .dst_reg = 0,                                   \
 290                 .src_reg = 0,                                   \
 291                 .off   = 0,                                     \
 292                 .imm   = 0 })
 293
 294 /* Internal classic blocks for direct assignment */
 295
 296 #define __BPF_STMT(CODE, K)                                     \
 297         ((struct sock_filter) BPF_STMT(CODE, K))
 298
 299 #define __BPF_JUMP(CODE, K, JT, JF)                             \
 300         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 301
 302 #define bytes_to_bpf_size(bytes)                                \
 303 ({                                                              \
 304         int bpf_size = -EINVAL;                                 \
 305                                                                 \
 306         if (bytes == sizeof(u8))                                \
 307                 bpf_size = BPF_B;                               \
 308         else if (bytes == sizeof(u16))                          \
 309                 bpf_size = BPF_H;                               \
 310         else if (bytes == sizeof(u32))                          \
 311                 bpf_size = BPF_W;                               \
 312         else if (bytes == sizeof(u64))                          \
 313                 bpf_size = BPF_DW;                              \
 314                                                                 \
 315         bpf_size;                                               \
 316 })
 317
 318 #define BPF_SIZEOF(type)                                        \
 319         ({                                                      \
 320                 const int __size = bytes_to_bpf_size(sizeof(type)); \
 321                 BUILD_BUG_ON(__size < 0);                       \
 322                 __size;                                         \
 323         })
 324
 325 #define BPF_FIELD_SIZEOF(type, field)                           \
 326         ({                                                      \
 327                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 328                 BUILD_BUG_ON(__size < 0);                       \
 329                 __size;                                         \
 330         })
 331
 332 #define __BPF_MAP_0(m, v, ...) v
 333 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 334 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 335 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 336 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 337 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 338
 339 #define __BPF_REG_0(...) __BPF_PAD(5)
 340 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 341 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 342 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 343 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 344 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 345
 346 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 347 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 348
 349 #define __BPF_CAST(t, a)                                                       \
 350         (__force t)                                                            \
 351         (__force                                                               \
 352          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 353                                       (unsigned long)0, (t)0))) a
 354 #define __BPF_V void
 355 #define __BPF_N
 356
 357 #define __BPF_DECL_ARGS(t, a) t   a
 358 #define __BPF_DECL_REGS(t, a) u64 a
 359
 360 #define __BPF_PAD(n)                                                           \
 361         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 362                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
 363
 364 #define BPF_CALL_x(x, name, ...)                                               \
 365         static __always_inline                                                 \
 366         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 367         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 368         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 369         {                                                                      \
 370                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 371         }                                                                      \
 372         static __always_inline                                                 \
 373         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 374
 375 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 376 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 377 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 378 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 379 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 380 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 381
 382 #ifdef CONFIG_COMPAT
 383 /* A struct sock_filter is architecture independent. */
 384 struct compat_sock_fprog {
 385         u16             len;
 386         compat_uptr_t   filter; /* struct sock_filter * */
 387 };
 388 #endif
 389
 390 struct sock_fprog_kern {
 391         u16                     len;
 392         struct sock_filter      *filter;
 393 };
 394
 395 struct bpf_binary_header {
 396         unsigned int pages;
 397         u8 image[];
 398 };
 399
 400 struct bpf_prog {
 401         u16                     pages;          /* Number of allocated pages */
 402         kmemcheck_bitfield_begin(meta);
 403         u16                     jited:1,        /* Is our filter JIT'ed? */
 404                                 gpl_compatible:1, /* Is filter GPL compatible? */
 405                                 cb_access:1,    /* Is control block accessed? */
 406                                 dst_needed:1,   /* Do we need dst entry? */
 407                                 xdp_adjust_head:1; /* Adjusting pkt head? */
 408         kmemcheck_bitfield_end(meta);
 409         enum bpf_prog_type      type;           /* Type of BPF program */
 410         u32                     len;            /* Number of filter blocks */
 411         u32                     digest[SHA_DIGEST_WORDS]; /* Program digest */
 412         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 413         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 414         unsigned int            (*bpf_func)(const void *ctx,
 415                                             const struct bpf_insn *insn);
 416         /* Instructions for interpreter */
 417         union {
 418                 struct sock_filter      insns[0];
 419                 struct bpf_insn         insnsi[0];
 420         };
 421 };
 422
 423 struct sk_filter {
 424         atomic_t        refcnt;
 425         struct rcu_head rcu;
 426         struct bpf_prog *prog;
 427 };
 428
 429 #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
 430
 431 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 432
 433 struct bpf_skb_data_end {
 434         struct qdisc_skb_cb qdisc_cb;
 435         void *data_end;
 436 };
 437
 438 struct xdp_buff {
 439         void *data;
 440         void *data_end;
 441         void *data_hard_start;
 442 };
 443
 444 /* compute the linear packet data range [data, data_end) which
 445  * will be accessed by cls_bpf, act_bpf and lwt programs
 446  */
 447 static inline void bpf_compute_data_end(struct sk_buff *skb)
 448 {
 449         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 450
 451         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 452         cb->data_end = skb->data + skb_headlen(skb);
 453 }
 454
 455 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 456 {
 457         /* eBPF programs may read/write skb->cb[] area to transfer meta
 458          * data between tail calls. Since this also needs to work with
 459          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 460          *
 461          * In some socket filter cases, the cb unfortunately needs to be
 462          * saved/restored so that protocol specific skb->cb[] data won't
 463          * be lost. In any case, due to unpriviledged eBPF programs
 464          * attached to sockets, we need to clear the bpf_skb_cb() area
 465          * to not leak previous contents to user space.
 466          */
 467         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 468         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 469                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
 470
 471         return qdisc_skb_cb(skb)->data;
 472 }
 473
 474 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 475                                        struct sk_buff *skb)
 476 {
 477         u8 *cb_data = bpf_skb_cb(skb);
 478         u8 cb_saved[BPF_SKB_CB_LEN];
 479         u32 res;
 480
 481         if (unlikely(prog->cb_access)) {
 482                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
 483                 memset(cb_data, 0, sizeof(cb_saved));
 484         }
 485
 486         res = BPF_PROG_RUN(prog, skb);
 487
 488         if (unlikely(prog->cb_access))
 489                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
 490
 491         return res;
 492 }
 493
 494 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 495                                         struct sk_buff *skb)
 496 {
 497         u8 *cb_data = bpf_skb_cb(skb);
 498
 499         if (unlikely(prog->cb_access))
 500                 memset(cb_data, 0, BPF_SKB_CB_LEN);
 501
 502         return BPF_PROG_RUN(prog, skb);
 503 }
 504
 505 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 506                                             struct xdp_buff *xdp)
 507 {
 508         /* Caller needs to hold rcu_read_lock() (!), otherwise program
 509          * can be released while still running, or map elements could be
 510          * freed early while still having concurrent users. XDP fastpath
 511          * already takes rcu_read_lock() when fetching the program, so
 512          * it's not necessary here anymore.
 513          */
 514         return BPF_PROG_RUN(prog, xdp);
 515 }
 516
 517 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 518 {
 519         return prog->len * sizeof(struct bpf_insn);
 520 }
 521
 522 static inline u32 bpf_prog_digest_scratch_size(const struct bpf_prog *prog)
 523 {
 524         return round_up(bpf_prog_insn_size(prog) +
 525                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 526 }
 527
 528 static inline unsigned int bpf_prog_size(unsigned int proglen)
 529 {
 530         return max(sizeof(struct bpf_prog),
 531                    offsetof(struct bpf_prog, insns[proglen]));
 532 }
 533
 534 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 535 {
 536         /* When classic BPF programs have been loaded and the arch
 537          * does not have a classic BPF JIT (anymore), they have been
 538          * converted via bpf_migrate_filter() to eBPF and thus always
 539          * have an unspec program type.
 540          */
 541         return prog->type == BPF_PROG_TYPE_UNSPEC;
 542 }
 543
 544 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 545
 546 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 547 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 548 {
 549         set_memory_ro((unsigned long)fp, fp->pages);
 550 }
 551
 552 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 553 {
 554         set_memory_rw((unsigned long)fp, fp->pages);
 555 }
 556 #else
 557 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 558 {
 559 }
 560
 561 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 562 {
 563 }
 564 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */
 565
 566 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 567 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 568 {
 569         return sk_filter_trim_cap(sk, skb, 1);
 570 }
 571
 572 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 573 void bpf_prog_free(struct bpf_prog *fp);
 574
 575 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 576 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 577                                   gfp_t gfp_extra_flags);
 578 void __bpf_prog_free(struct bpf_prog *fp);
 579
 580 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 581 {
 582         bpf_prog_unlock_ro(fp);
 583         __bpf_prog_free(fp);
 584 }
 585
 586 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 587                                        unsigned int flen);
 588
 589 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 590 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 591                               bpf_aux_classic_check_t trans, bool save_orig);
 592 void bpf_prog_destroy(struct bpf_prog *fp);
 593
 594 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 595 int sk_attach_bpf(u32 ufd, struct sock *sk);
 596 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 597 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 598 int sk_detach_filter(struct sock *sk);
 599 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 600                   unsigned int len);
 601
 602 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 603 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 604
 605 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 606
 607 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 608 bool bpf_helper_changes_pkt_data(void *func);
 609
 610 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 611                                        const struct bpf_insn *patch, u32 len);
 612 void bpf_warn_invalid_xdp_action(u32 act);
 613
 614 #ifdef CONFIG_BPF_JIT
 615 extern int bpf_jit_enable;
 616 extern int bpf_jit_harden;
 617
 618 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 619
 620 struct bpf_binary_header *
 621 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 622                      unsigned int alignment,
 623                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
 624 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 625
 626 void bpf_jit_compile(struct bpf_prog *fp);
 627 void bpf_jit_free(struct bpf_prog *fp);
 628
 629 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 630 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 631
 632 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 633                                 u32 pass, void *image)
 634 {
 635         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 636                proglen, pass, image, current->comm, task_pid_nr(current));
 637
 638         if (image)
 639                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 640                                16, 1, image, proglen, false);
 641 }
 642
 643 static inline bool bpf_jit_is_ebpf(void)
 644 {
 645 # ifdef CONFIG_HAVE_EBPF_JIT
 646         return true;
 647 # else
 648         return false;
 649 # endif
 650 }
 651
 652 static inline bool bpf_jit_blinding_enabled(void)
 653 {
 654         /* These are the prerequisites, should someone ever have the
 655          * idea to call blinding outside of them, we make sure to
 656          * bail out.
 657          */
 658         if (!bpf_jit_is_ebpf())
 659                 return false;
 660         if (!bpf_jit_enable)
 661                 return false;
 662         if (!bpf_jit_harden)
 663                 return false;
 664         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 665                 return false;
 666
 667         return true;
 668 }
 669 #else
 670 static inline void bpf_jit_compile(struct bpf_prog *fp)
 671 {
 672 }
 673
 674 static inline void bpf_jit_free(struct bpf_prog *fp)
 675 {
 676         bpf_prog_unlock_free(fp);
 677 }
 678 #endif /* CONFIG_BPF_JIT */
 679
 680 #define BPF_ANC         BIT(15)
 681
 682 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
 683 {
 684         switch (first->code) {
 685         case BPF_RET | BPF_K:
 686         case BPF_LD | BPF_W | BPF_LEN:
 687                 return false;
 688
 689         case BPF_LD | BPF_W | BPF_ABS:
 690         case BPF_LD | BPF_H | BPF_ABS:
 691         case BPF_LD | BPF_B | BPF_ABS:
 692                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
 693                         return true;
 694                 return false;
 695
 696         default:
 697                 return true;
 698         }
 699 }
 700
 701 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 702 {
 703         BUG_ON(ftest->code & BPF_ANC);
 704
 705         switch (ftest->code) {
 706         case BPF_LD | BPF_W | BPF_ABS:
 707         case BPF_LD | BPF_H | BPF_ABS:
 708         case BPF_LD | BPF_B | BPF_ABS:
 709 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
 710                                 return BPF_ANC | SKF_AD_##CODE
 711                 switch (ftest->k) {
 712                 BPF_ANCILLARY(PROTOCOL);
 713                 BPF_ANCILLARY(PKTTYPE);
 714                 BPF_ANCILLARY(IFINDEX);
 715                 BPF_ANCILLARY(NLATTR);
 716                 BPF_ANCILLARY(NLATTR_NEST);
 717                 BPF_ANCILLARY(MARK);
 718                 BPF_ANCILLARY(QUEUE);
 719                 BPF_ANCILLARY(HATYPE);
 720                 BPF_ANCILLARY(RXHASH);
 721                 BPF_ANCILLARY(CPU);
 722                 BPF_ANCILLARY(ALU_XOR_X);
 723                 BPF_ANCILLARY(VLAN_TAG);
 724                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
 725                 BPF_ANCILLARY(PAY_OFFSET);
 726                 BPF_ANCILLARY(RANDOM);
 727                 BPF_ANCILLARY(VLAN_TPID);
 728                 }
 729                 /* Fallthrough. */
 730         default:
 731                 return ftest->code;
 732         }
 733 }
 734
 735 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 736                                            int k, unsigned int size);
 737
 738 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
 739                                      unsigned int size, void *buffer)
 740 {
 741         if (k >= 0)
 742                 return skb_header_pointer(skb, k, size, buffer);
 743
 744         return bpf_internal_load_pointer_neg_helper(skb, k, size);
 745 }
 746
 747 static inline int bpf_tell_extensions(void)
 748 {
 749         return SKF_AD_MAX;
 750 }
 751
 752 #endif /* __LINUX_FILTER_H__ */