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