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