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