linux/include/linux/filter.h
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   1/*
   2 * Linux Socket Filter Data Structures
   3 */
   4#ifndef __LINUX_FILTER_H__
   5#define __LINUX_FILTER_H__
   6
   7#include <stdarg.h>
   8
   9#include <linux/atomic.h>
  10#include <linux/refcount.h>
  11#include <linux/compat.h>
  12#include <linux/skbuff.h>
  13#include <linux/linkage.h>
  14#include <linux/printk.h>
  15#include <linux/workqueue.h>
  16#include <linux/sched.h>
  17#include <linux/capability.h>
  18#include <linux/cryptohash.h>
  19
  20#include <net/sch_generic.h>
  21
  22#ifdef CONFIG_ARCH_HAS_SET_MEMORY
  23#include <asm/set_memory.h>
  24#endif
  25
  26#include <uapi/linux/filter.h>
  27#include <uapi/linux/bpf.h>
  28
  29struct sk_buff;
  30struct sock;
  31struct seccomp_data;
  32struct bpf_prog_aux;
  33
  34/* ArgX, context and stack frame pointer register positions. Note,
  35 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  36 * calls in BPF_CALL instruction.
  37 */
  38#define BPF_REG_ARG1    BPF_REG_1
  39#define BPF_REG_ARG2    BPF_REG_2
  40#define BPF_REG_ARG3    BPF_REG_3
  41#define BPF_REG_ARG4    BPF_REG_4
  42#define BPF_REG_ARG5    BPF_REG_5
  43#define BPF_REG_CTX     BPF_REG_6
  44#define BPF_REG_FP      BPF_REG_10
  45
  46/* Additional register mappings for converted user programs. */
  47#define BPF_REG_A       BPF_REG_0
  48#define BPF_REG_X       BPF_REG_7
  49#define BPF_REG_TMP     BPF_REG_8
  50
  51/* Kernel hidden auxiliary/helper register for hardening step.
  52 * Only used by eBPF JITs. It's nothing more than a temporary
  53 * register that JITs use internally, only that here it's part
  54 * of eBPF instructions that have been rewritten for blinding
  55 * constants. See JIT pre-step in bpf_jit_blind_constants().
  56 */
  57#define BPF_REG_AX              MAX_BPF_REG
  58#define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
  59
  60/* As per nm, we expose JITed images as text (code) section for
  61 * kallsyms. That way, tools like perf can find it to match
  62 * addresses.
  63 */
  64#define BPF_SYM_ELF_TYPE        't'
  65
  66/* BPF program can access up to 512 bytes of stack space. */
  67#define MAX_BPF_STACK   512
  68
  69#define BPF_TAG_SIZE    8
  70
  71/* Helper macros for filter block array initializers. */
  72
  73/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  74
  75#define BPF_ALU64_REG(OP, DST, SRC)                             \
  76        ((struct bpf_insn) {                                    \
  77                .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  78                .dst_reg = DST,                                 \
  79                .src_reg = SRC,                                 \
  80                .off   = 0,                                     \
  81                .imm   = 0 })
  82
  83#define BPF_ALU32_REG(OP, DST, SRC)                             \
  84        ((struct bpf_insn) {                                    \
  85                .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  86                .dst_reg = DST,                                 \
  87                .src_reg = SRC,                                 \
  88                .off   = 0,                                     \
  89                .imm   = 0 })
  90
  91/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  92
  93#define BPF_ALU64_IMM(OP, DST, IMM)                             \
  94        ((struct bpf_insn) {                                    \
  95                .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  96                .dst_reg = DST,                                 \
  97                .src_reg = 0,                                   \
  98                .off   = 0,                                     \
  99                .imm   = IMM })
 100
 101#define BPF_ALU32_IMM(OP, DST, IMM)                             \
 102        ((struct bpf_insn) {                                    \
 103                .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
 104                .dst_reg = DST,                                 \
 105                .src_reg = 0,                                   \
 106                .off   = 0,                                     \
 107                .imm   = IMM })
 108
 109/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
 110
 111#define BPF_ENDIAN(TYPE, DST, LEN)                              \
 112        ((struct bpf_insn) {                                    \
 113                .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
 114                .dst_reg = DST,                                 \
 115                .src_reg = 0,                                   \
 116                .off   = 0,                                     \
 117                .imm   = LEN })
 118
 119/* Short form of mov, dst_reg = src_reg */
 120
 121#define BPF_MOV64_REG(DST, SRC)                                 \
 122        ((struct bpf_insn) {                                    \
 123                .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
 124                .dst_reg = DST,                                 \
 125                .src_reg = SRC,                                 \
 126                .off   = 0,                                     \
 127                .imm   = 0 })
 128
 129#define BPF_MOV32_REG(DST, SRC)                                 \
 130        ((struct bpf_insn) {                                    \
 131                .code  = BPF_ALU | BPF_MOV | BPF_X,             \
 132                .dst_reg = DST,                                 \
 133                .src_reg = SRC,                                 \
 134                .off   = 0,                                     \
 135                .imm   = 0 })
 136
 137/* Short form of mov, dst_reg = imm32 */
 138
 139#define BPF_MOV64_IMM(DST, IMM)                                 \
 140        ((struct bpf_insn) {                                    \
 141                .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 142                .dst_reg = DST,                                 \
 143                .src_reg = 0,                                   \
 144                .off   = 0,                                     \
 145                .imm   = IMM })
 146
 147#define BPF_MOV32_IMM(DST, IMM)                                 \
 148        ((struct bpf_insn) {                                    \
 149                .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 150                .dst_reg = DST,                                 \
 151                .src_reg = 0,                                   \
 152                .off   = 0,                                     \
 153                .imm   = IMM })
 154
 155/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 156#define BPF_LD_IMM64(DST, IMM)                                  \
 157        BPF_LD_IMM64_RAW(DST, 0, IMM)
 158
 159#define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 160        ((struct bpf_insn) {                                    \
 161                .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 162                .dst_reg = DST,                                 \
 163                .src_reg = SRC,                                 \
 164                .off   = 0,                                     \
 165                .imm   = (__u32) (IMM) }),                      \
 166        ((struct bpf_insn) {                                    \
 167                .code  = 0, /* zero is reserved opcode */       \
 168                .dst_reg = 0,                                   \
 169                .src_reg = 0,                                   \
 170                .off   = 0,                                     \
 171                .imm   = ((__u64) (IMM)) >> 32 })
 172
 173/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 174#define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 175        BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 176
 177/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 178
 179#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 180        ((struct bpf_insn) {                                    \
 181                .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 182                .dst_reg = DST,                                 \
 183                .src_reg = SRC,                                 \
 184                .off   = 0,                                     \
 185                .imm   = IMM })
 186
 187#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 188        ((struct bpf_insn) {                                    \
 189                .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 190                .dst_reg = DST,                                 \
 191                .src_reg = SRC,                                 \
 192                .off   = 0,                                     \
 193                .imm   = IMM })
 194
 195/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 196
 197#define BPF_LD_ABS(SIZE, IMM)                                   \
 198        ((struct bpf_insn) {                                    \
 199                .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 200                .dst_reg = 0,                                   \
 201                .src_reg = 0,                                   \
 202                .off   = 0,                                     \
 203                .imm   = IMM })
 204
 205/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 206
 207#define BPF_LD_IND(SIZE, SRC, IMM)                              \
 208        ((struct bpf_insn) {                                    \
 209                .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 210                .dst_reg = 0,                                   \
 211                .src_reg = SRC,                                 \
 212                .off   = 0,                                     \
 213                .imm   = IMM })
 214
 215/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 216
 217#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 218        ((struct bpf_insn) {                                    \
 219                .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 220                .dst_reg = DST,                                 \
 221                .src_reg = SRC,                                 \
 222                .off   = OFF,                                   \
 223                .imm   = 0 })
 224
 225/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 226
 227#define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 228        ((struct bpf_insn) {                                    \
 229                .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 230                .dst_reg = DST,                                 \
 231                .src_reg = SRC,                                 \
 232                .off   = OFF,                                   \
 233                .imm   = 0 })
 234
 235/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 236
 237#define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 238        ((struct bpf_insn) {                                    \
 239                .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 240                .dst_reg = DST,                                 \
 241                .src_reg = SRC,                                 \
 242                .off   = OFF,                                   \
 243                .imm   = 0 })
 244
 245/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 246
 247#define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 248        ((struct bpf_insn) {                                    \
 249                .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 250                .dst_reg = DST,                                 \
 251                .src_reg = 0,                                   \
 252                .off   = OFF,                                   \
 253                .imm   = IMM })
 254
 255/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 256
 257#define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 258        ((struct bpf_insn) {                                    \
 259                .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 260                .dst_reg = DST,                                 \
 261                .src_reg = SRC,                                 \
 262                .off   = OFF,                                   \
 263                .imm   = 0 })
 264
 265/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 266
 267#define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 268        ((struct bpf_insn) {                                    \
 269                .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 270                .dst_reg = DST,                                 \
 271                .src_reg = 0,                                   \
 272                .off   = OFF,                                   \
 273                .imm   = IMM })
 274
 275/* Unconditional jumps, goto pc + off16 */
 276
 277#define BPF_JMP_A(OFF)                                          \
 278        ((struct bpf_insn) {                                    \
 279                .code  = BPF_JMP | BPF_JA,                      \
 280                .dst_reg = 0,                                   \
 281                .src_reg = 0,                                   \
 282                .off   = OFF,                                   \
 283                .imm   = 0 })
 284
 285/* Function call */
 286
 287#define BPF_EMIT_CALL(FUNC)                                     \
 288        ((struct bpf_insn) {                                    \
 289                .code  = BPF_JMP | BPF_CALL,                    \
 290                .dst_reg = 0,                                   \
 291                .src_reg = 0,                                   \
 292                .off   = 0,                                     \
 293                .imm   = ((FUNC) - __bpf_call_base) })
 294
 295/* Raw code statement block */
 296
 297#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 298        ((struct bpf_insn) {                                    \
 299                .code  = CODE,                                  \
 300                .dst_reg = DST,                                 \
 301                .src_reg = SRC,                                 \
 302                .off   = OFF,                                   \
 303                .imm   = IMM })
 304
 305/* Program exit */
 306
 307#define BPF_EXIT_INSN()                                         \
 308        ((struct bpf_insn) {                                    \
 309                .code  = BPF_JMP | BPF_EXIT,                    \
 310                .dst_reg = 0,                                   \
 311                .src_reg = 0,                                   \
 312                .off   = 0,                                     \
 313                .imm   = 0 })
 314
 315/* Internal classic blocks for direct assignment */
 316
 317#define __BPF_STMT(CODE, K)                                     \
 318        ((struct sock_filter) BPF_STMT(CODE, K))
 319
 320#define __BPF_JUMP(CODE, K, JT, JF)                             \
 321        ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
 322
 323#define bytes_to_bpf_size(bytes)                                \
 324({                                                              \
 325        int bpf_size = -EINVAL;                                 \
 326                                                                \
 327        if (bytes == sizeof(u8))                                \
 328                bpf_size = BPF_B;                               \
 329        else if (bytes == sizeof(u16))                          \
 330                bpf_size = BPF_H;                               \
 331        else if (bytes == sizeof(u32))                          \
 332                bpf_size = BPF_W;                               \
 333        else if (bytes == sizeof(u64))                          \
 334                bpf_size = BPF_DW;                              \
 335                                                                \
 336        bpf_size;                                               \
 337})
 338
 339#define BPF_SIZEOF(type)                                        \
 340        ({                                                      \
 341                const int __size = bytes_to_bpf_size(sizeof(type)); \
 342                BUILD_BUG_ON(__size < 0);                       \
 343                __size;                                         \
 344        })
 345
 346#define BPF_FIELD_SIZEOF(type, field)                           \
 347        ({                                                      \
 348                const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
 349                BUILD_BUG_ON(__size < 0);                       \
 350                __size;                                         \
 351        })
 352
 353#define __BPF_MAP_0(m, v, ...) v
 354#define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
 355#define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
 356#define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
 357#define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
 358#define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
 359
 360#define __BPF_REG_0(...) __BPF_PAD(5)
 361#define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
 362#define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
 363#define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
 364#define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
 365#define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
 366
 367#define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
 368#define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
 369
 370#define __BPF_CAST(t, a)                                                       \
 371        (__force t)                                                            \
 372        (__force                                                               \
 373         typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
 374                                      (unsigned long)0, (t)0))) a
 375#define __BPF_V void
 376#define __BPF_N
 377
 378#define __BPF_DECL_ARGS(t, a) t   a
 379#define __BPF_DECL_REGS(t, a) u64 a
 380
 381#define __BPF_PAD(n)                                                           \
 382        __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
 383                  u64, __ur_3, u64, __ur_4, u64, __ur_5)
 384
 385#define BPF_CALL_x(x, name, ...)                                               \
 386        static __always_inline                                                 \
 387        u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
 388        u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
 389        u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
 390        {                                                                      \
 391                return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
 392        }                                                                      \
 393        static __always_inline                                                 \
 394        u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
 395
 396#define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
 397#define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
 398#define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
 399#define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
 400#define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
 401#define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
 402
 403#ifdef CONFIG_COMPAT
 404/* A struct sock_filter is architecture independent. */
 405struct compat_sock_fprog {
 406        u16             len;
 407        compat_uptr_t   filter; /* struct sock_filter * */
 408};
 409#endif
 410
 411struct sock_fprog_kern {
 412        u16                     len;
 413        struct sock_filter      *filter;
 414};
 415
 416struct bpf_binary_header {
 417        unsigned int pages;
 418        u8 image[];
 419};
 420
 421struct bpf_prog {
 422        u16                     pages;          /* Number of allocated pages */
 423        kmemcheck_bitfield_begin(meta);
 424        u16                     jited:1,        /* Is our filter JIT'ed? */
 425                                locked:1,       /* Program image locked? */
 426                                gpl_compatible:1, /* Is filter GPL compatible? */
 427                                cb_access:1,    /* Is control block accessed? */
 428                                dst_needed:1;   /* Do we need dst entry? */
 429        kmemcheck_bitfield_end(meta);
 430        enum bpf_prog_type      type;           /* Type of BPF program */
 431        u32                     len;            /* Number of filter blocks */
 432        u8                      tag[BPF_TAG_SIZE];
 433        struct bpf_prog_aux     *aux;           /* Auxiliary fields */
 434        struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
 435        unsigned int            (*bpf_func)(const void *ctx,
 436                                            const struct bpf_insn *insn);
 437        /* Instructions for interpreter */
 438        union {
 439                struct sock_filter      insns[0];
 440                struct bpf_insn         insnsi[0];
 441        };
 442};
 443
 444struct sk_filter {
 445        refcount_t      refcnt;
 446        struct rcu_head rcu;
 447        struct bpf_prog *prog;
 448};
 449
 450#define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
 451
 452#define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 453
 454struct bpf_skb_data_end {
 455        struct qdisc_skb_cb qdisc_cb;
 456        void *data_end;
 457};
 458
 459struct xdp_buff {
 460        void *data;
 461        void *data_end;
 462        void *data_hard_start;
 463};
 464
 465/* compute the linear packet data range [data, data_end) which
 466 * will be accessed by cls_bpf, act_bpf and lwt programs
 467 */
 468static inline void bpf_compute_data_end(struct sk_buff *skb)
 469{
 470        struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
 471
 472        BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
 473        cb->data_end = skb->data + skb_headlen(skb);
 474}
 475
 476static inline u8 *bpf_skb_cb(struct sk_buff *skb)
 477{
 478        /* eBPF programs may read/write skb->cb[] area to transfer meta
 479         * data between tail calls. Since this also needs to work with
 480         * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
 481         *
 482         * In some socket filter cases, the cb unfortunately needs to be
 483         * saved/restored so that protocol specific skb->cb[] data won't
 484         * be lost. In any case, due to unpriviledged eBPF programs
 485         * attached to sockets, we need to clear the bpf_skb_cb() area
 486         * to not leak previous contents to user space.
 487         */
 488        BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
 489        BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
 490                     FIELD_SIZEOF(struct qdisc_skb_cb, data));
 491
 492        return qdisc_skb_cb(skb)->data;
 493}
 494
 495static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 496                                       struct sk_buff *skb)
 497{
 498        u8 *cb_data = bpf_skb_cb(skb);
 499        u8 cb_saved[BPF_SKB_CB_LEN];
 500        u32 res;
 501
 502        if (unlikely(prog->cb_access)) {
 503                memcpy(cb_saved, cb_data, sizeof(cb_saved));
 504                memset(cb_data, 0, sizeof(cb_saved));
 505        }
 506
 507        res = BPF_PROG_RUN(prog, skb);
 508
 509        if (unlikely(prog->cb_access))
 510                memcpy(cb_data, cb_saved, sizeof(cb_saved));
 511
 512        return res;
 513}
 514
 515static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
 516                                        struct sk_buff *skb)
 517{
 518        u8 *cb_data = bpf_skb_cb(skb);
 519
 520        if (unlikely(prog->cb_access))
 521                memset(cb_data, 0, BPF_SKB_CB_LEN);
 522
 523        return BPF_PROG_RUN(prog, skb);
 524}
 525
 526static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
 527                                            struct xdp_buff *xdp)
 528{
 529        /* Caller needs to hold rcu_read_lock() (!), otherwise program
 530         * can be released while still running, or map elements could be
 531         * freed early while still having concurrent users. XDP fastpath
 532         * already takes rcu_read_lock() when fetching the program, so
 533         * it's not necessary here anymore.
 534         */
 535        return BPF_PROG_RUN(prog, xdp);
 536}
 537
 538static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
 539{
 540        return prog->len * sizeof(struct bpf_insn);
 541}
 542
 543static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
 544{
 545        return round_up(bpf_prog_insn_size(prog) +
 546                        sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
 547}
 548
 549static inline unsigned int bpf_prog_size(unsigned int proglen)
 550{
 551        return max(sizeof(struct bpf_prog),
 552                   offsetof(struct bpf_prog, insns[proglen]));
 553}
 554
 555static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
 556{
 557        /* When classic BPF programs have been loaded and the arch
 558         * does not have a classic BPF JIT (anymore), they have been
 559         * converted via bpf_migrate_filter() to eBPF and thus always
 560         * have an unspec program type.
 561         */
 562        return prog->type == BPF_PROG_TYPE_UNSPEC;
 563}
 564
 565#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
 566
 567#ifdef CONFIG_ARCH_HAS_SET_MEMORY
 568static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 569{
 570        fp->locked = 1;
 571        WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
 572}
 573
 574static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 575{
 576        if (fp->locked) {
 577                WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
 578                /* In case set_memory_rw() fails, we want to be the first
 579                 * to crash here instead of some random place later on.
 580                 */
 581                fp->locked = 0;
 582        }
 583}
 584
 585static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 586{
 587        WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
 588}
 589
 590static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 591{
 592        WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
 593}
 594#else
 595static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
 596{
 597}
 598
 599static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 600{
 601}
 602
 603static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 604{
 605}
 606
 607static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
 608{
 609}
 610#endif /* CONFIG_ARCH_HAS_SET_MEMORY */
 611
 612static inline struct bpf_binary_header *
 613bpf_jit_binary_hdr(const struct bpf_prog *fp)
 614{
 615        unsigned long real_start = (unsigned long)fp->bpf_func;
 616        unsigned long addr = real_start & PAGE_MASK;
 617
 618        return (void *)addr;
 619}
 620
 621int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
 622static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 623{
 624        return sk_filter_trim_cap(sk, skb, 1);
 625}
 626
 627struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
 628void bpf_prog_free(struct bpf_prog *fp);
 629
 630struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 631struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 632                                  gfp_t gfp_extra_flags);
 633void __bpf_prog_free(struct bpf_prog *fp);
 634
 635static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
 636{
 637        bpf_prog_unlock_ro(fp);
 638        __bpf_prog_free(fp);
 639}
 640
 641typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
 642                                       unsigned int flen);
 643
 644int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
 645int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
 646                              bpf_aux_classic_check_t trans, bool save_orig);
 647void bpf_prog_destroy(struct bpf_prog *fp);
 648
 649int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 650int sk_attach_bpf(u32 ufd, struct sock *sk);
 651int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
 652int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
 653int sk_detach_filter(struct sock *sk);
 654int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
 655                  unsigned int len);
 656
 657bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
 658void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
 659
 660u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 661
 662struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 663void bpf_jit_compile(struct bpf_prog *prog);
 664bool bpf_helper_changes_pkt_data(void *func);
 665
 666struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 667                                       const struct bpf_insn *patch, u32 len);
 668void bpf_warn_invalid_xdp_action(u32 act);
 669
 670#ifdef CONFIG_BPF_JIT
 671extern int bpf_jit_enable;
 672extern int bpf_jit_harden;
 673extern int bpf_jit_kallsyms;
 674
 675typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
 676
 677struct bpf_binary_header *
 678bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 679                     unsigned int alignment,
 680                     bpf_jit_fill_hole_t bpf_fill_ill_insns);
 681void bpf_jit_binary_free(struct bpf_binary_header *hdr);
 682
 683void bpf_jit_free(struct bpf_prog *fp);
 684
 685struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 686void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 687
 688static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
 689                                u32 pass, void *image)
 690{
 691        pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
 692               proglen, pass, image, current->comm, task_pid_nr(current));
 693
 694        if (image)
 695                print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
 696                               16, 1, image, proglen, false);
 697}
 698
 699static inline bool bpf_jit_is_ebpf(void)
 700{
 701# ifdef CONFIG_HAVE_EBPF_JIT
 702        return true;
 703# else
 704        return false;
 705# endif
 706}
 707
 708static inline bool ebpf_jit_enabled(void)
 709{
 710        return bpf_jit_enable && bpf_jit_is_ebpf();
 711}
 712
 713static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 714{
 715        return fp->jited && bpf_jit_is_ebpf();
 716}
 717
 718static inline bool bpf_jit_blinding_enabled(void)
 719{
 720        /* These are the prerequisites, should someone ever have the
 721         * idea to call blinding outside of them, we make sure to
 722         * bail out.
 723         */
 724        if (!bpf_jit_is_ebpf())
 725                return false;
 726        if (!bpf_jit_enable)
 727                return false;
 728        if (!bpf_jit_harden)
 729                return false;
 730        if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
 731                return false;
 732
 733        return true;
 734}
 735
 736static inline bool bpf_jit_kallsyms_enabled(void)
 737{
 738        /* There are a couple of corner cases where kallsyms should
 739         * not be enabled f.e. on hardening.
 740         */
 741        if (bpf_jit_harden)
 742                return false;
 743        if (!bpf_jit_kallsyms)
 744                return false;
 745        if (bpf_jit_kallsyms == 1)
 746                return true;
 747
 748        return false;
 749}
 750
 751const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 752                                 unsigned long *off, char *sym);
 753bool is_bpf_text_address(unsigned long addr);
 754int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 755                    char *sym);
 756
 757static inline const char *
 758bpf_address_lookup(unsigned long addr, unsigned long *size,
 759                   unsigned long *off, char **modname, char *sym)
 760{
 761        const char *ret = __bpf_address_lookup(addr, size, off, sym);
 762
 763        if (ret && modname)
 764                *modname = NULL;
 765        return ret;
 766}
 767
 768void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 769void bpf_prog_kallsyms_del(struct bpf_prog *fp);
 770
 771#else /* CONFIG_BPF_JIT */
 772
 773static inline bool ebpf_jit_enabled(void)
 774{
 775        return false;
 776}
 777
 778static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
 779{
 780        return false;
 781}
 782
 783static inline void bpf_jit_free(struct bpf_prog *fp)
 784{
 785        bpf_prog_unlock_free(fp);
 786}
 787
 788static inline bool bpf_jit_kallsyms_enabled(void)
 789{
 790        return false;
 791}
 792
 793static inline const char *
 794__bpf_address_lookup(unsigned long addr, unsigned long *size,
 795                     unsigned long *off, char *sym)
 796{
 797        return NULL;
 798}
 799
 800static inline bool is_bpf_text_address(unsigned long addr)
 801{
 802        return false;
 803}
 804
 805static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
 806                                  char *type, char *sym)
 807{
 808        return -ERANGE;
 809}
 810
 811static inline const char *
 812bpf_address_lookup(unsigned long addr, unsigned long *size,
 813                   unsigned long *off, char **modname, char *sym)
 814{
 815        return NULL;
 816}
 817
 818static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 819{
 820}
 821
 822static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 823{
 824}
 825#endif /* CONFIG_BPF_JIT */
 826
 827#define BPF_ANC         BIT(15)
 828
 829static inline bool bpf_needs_clear_a(const struct sock_filter *first)
 830{
 831        switch (first->code) {
 832        case BPF_RET | BPF_K:
 833        case BPF_LD | BPF_W | BPF_LEN:
 834                return false;
 835
 836        case BPF_LD | BPF_W | BPF_ABS:
 837        case BPF_LD | BPF_H | BPF_ABS:
 838        case BPF_LD | BPF_B | BPF_ABS:
 839                if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
 840                        return true;
 841                return false;
 842
 843        default:
 844                return true;
 845        }
 846}
 847
 848static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 849{
 850        BUG_ON(ftest->code & BPF_ANC);
 851
 852        switch (ftest->code) {
 853        case BPF_LD | BPF_W | BPF_ABS:
 854        case BPF_LD | BPF_H | BPF_ABS:
 855        case BPF_LD | BPF_B | BPF_ABS:
 856#define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
 857                                return BPF_ANC | SKF_AD_##CODE
 858                switch (ftest->k) {
 859                BPF_ANCILLARY(PROTOCOL);
 860                BPF_ANCILLARY(PKTTYPE);
 861                BPF_ANCILLARY(IFINDEX);
 862                BPF_ANCILLARY(NLATTR);
 863                BPF_ANCILLARY(NLATTR_NEST);
 864                BPF_ANCILLARY(MARK);
 865                BPF_ANCILLARY(QUEUE);
 866                BPF_ANCILLARY(HATYPE);
 867                BPF_ANCILLARY(RXHASH);
 868                BPF_ANCILLARY(CPU);
 869                BPF_ANCILLARY(ALU_XOR_X);
 870                BPF_ANCILLARY(VLAN_TAG);
 871                BPF_ANCILLARY(VLAN_TAG_PRESENT);
 872                BPF_ANCILLARY(PAY_OFFSET);
 873                BPF_ANCILLARY(RANDOM);
 874                BPF_ANCILLARY(VLAN_TPID);
 875                }
 876                /* Fallthrough. */
 877        default:
 878                return ftest->code;
 879        }
 880}
 881
 882void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 883                                           int k, unsigned int size);
 884
 885static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
 886                                     unsigned int size, void *buffer)
 887{
 888        if (k >= 0)
 889                return skb_header_pointer(skb, k, size, buffer);
 890
 891        return bpf_internal_load_pointer_neg_helper(skb, k, size);
 892}
 893
 894static inline int bpf_tell_extensions(void)
 895{
 896        return SKF_AD_MAX;
 897}
 898
 899#endif /* __LINUX_FILTER_H__ */
 900