2 * Linux Socket Filter Data Structures
4 #ifndef __LINUX_FILTER_H__
5 #define __LINUX_FILTER_H__
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>
19 #include <net/sch_generic.h>
21 #include <asm/cacheflush.h>
23 #include <uapi/linux/filter.h>
24 #include <uapi/linux/bpf.h>
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.
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
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
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().
54 #define BPF_REG_AX MAX_BPF_REG
55 #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1)
57 /* BPF program can access up to 512 bytes of stack space. */
58 #define MAX_BPF_STACK 512
60 /* Helper macros for filter block array initializers. */
62 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
64 #define BPF_ALU64_REG(OP, DST, SRC) \
65 ((struct bpf_insn) { \
66 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
72 #define BPF_ALU32_REG(OP, DST, SRC) \
73 ((struct bpf_insn) { \
74 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
80 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
82 #define BPF_ALU64_IMM(OP, DST, IMM) \
83 ((struct bpf_insn) { \
84 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
90 #define BPF_ALU32_IMM(OP, DST, IMM) \
91 ((struct bpf_insn) { \
92 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
98 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
100 #define BPF_ENDIAN(TYPE, DST, LEN) \
101 ((struct bpf_insn) { \
102 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
108 /* Short form of mov, dst_reg = src_reg */
110 #define BPF_MOV64_REG(DST, SRC) \
111 ((struct bpf_insn) { \
112 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
118 #define BPF_MOV32_REG(DST, SRC) \
119 ((struct bpf_insn) { \
120 .code = BPF_ALU | BPF_MOV | BPF_X, \
126 /* Short form of mov, dst_reg = imm32 */
128 #define BPF_MOV64_IMM(DST, IMM) \
129 ((struct bpf_insn) { \
130 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
136 #define BPF_MOV32_IMM(DST, IMM) \
137 ((struct bpf_insn) { \
138 .code = BPF_ALU | BPF_MOV | BPF_K, \
144 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
145 #define BPF_LD_IMM64(DST, IMM) \
146 BPF_LD_IMM64_RAW(DST, 0, IMM)
148 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
149 ((struct bpf_insn) { \
150 .code = BPF_LD | BPF_DW | BPF_IMM, \
154 .imm = (__u32) (IMM) }), \
155 ((struct bpf_insn) { \
156 .code = 0, /* zero is reserved opcode */ \
160 .imm = ((__u64) (IMM)) >> 32 })
162 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
163 #define BPF_LD_MAP_FD(DST, MAP_FD) \
164 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
166 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
168 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
169 ((struct bpf_insn) { \
170 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
176 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
177 ((struct bpf_insn) { \
178 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
184 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
186 #define BPF_LD_ABS(SIZE, IMM) \
187 ((struct bpf_insn) { \
188 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
194 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
196 #define BPF_LD_IND(SIZE, SRC, IMM) \
197 ((struct bpf_insn) { \
198 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
204 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
206 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
207 ((struct bpf_insn) { \
208 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
214 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
216 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
217 ((struct bpf_insn) { \
218 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
224 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
226 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
227 ((struct bpf_insn) { \
228 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
234 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
236 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
237 ((struct bpf_insn) { \
238 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
244 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
246 #define BPF_JMP_REG(OP, DST, SRC, OFF) \
247 ((struct bpf_insn) { \
248 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
254 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
256 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \
257 ((struct bpf_insn) { \
258 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
266 #define BPF_EMIT_CALL(FUNC) \
267 ((struct bpf_insn) { \
268 .code = BPF_JMP | BPF_CALL, \
272 .imm = ((FUNC) - __bpf_call_base) })
274 /* Raw code statement block */
276 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
277 ((struct bpf_insn) { \
286 #define BPF_EXIT_INSN() \
287 ((struct bpf_insn) { \
288 .code = BPF_JMP | BPF_EXIT, \
294 /* Internal classic blocks for direct assignment */
296 #define __BPF_STMT(CODE, K) \
297 ((struct sock_filter) BPF_STMT(CODE, K))
299 #define __BPF_JUMP(CODE, K, JT, JF) \
300 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
302 #define bytes_to_bpf_size(bytes) \
304 int bpf_size = -EINVAL; \
306 if (bytes == sizeof(u8)) \
308 else if (bytes == sizeof(u16)) \
310 else if (bytes == sizeof(u32)) \
312 else if (bytes == sizeof(u64)) \
318 #define BPF_SIZEOF(type) \
320 const int __size = bytes_to_bpf_size(sizeof(type)); \
321 BUILD_BUG_ON(__size < 0); \
325 #define BPF_FIELD_SIZEOF(type, field) \
327 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
328 BUILD_BUG_ON(__size < 0); \
332 #define __BPF_MAP_0(m, v, ...) v
333 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
334 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
335 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
336 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
337 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
339 #define __BPF_REG_0(...) __BPF_PAD(5)
340 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
341 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
342 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
343 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
344 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
346 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
347 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
349 #define __BPF_CAST(t, a) \
352 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \
353 (unsigned long)0, (t)0))) a
357 #define __BPF_DECL_ARGS(t, a) t a
358 #define __BPF_DECL_REGS(t, a) u64 a
360 #define __BPF_PAD(n) \
361 __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \
362 u64, __ur_3, u64, __ur_4, u64, __ur_5)
364 #define BPF_CALL_x(x, name, ...) \
365 static __always_inline \
366 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
367 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \
368 u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \
370 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
372 static __always_inline \
373 u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
375 #define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__)
376 #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__)
377 #define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__)
378 #define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__)
379 #define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__)
380 #define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__)
383 /* A struct sock_filter is architecture independent. */
384 struct compat_sock_fprog {
386 compat_uptr_t filter; /* struct sock_filter * */
390 struct sock_fprog_kern {
392 struct sock_filter *filter;
395 struct bpf_binary_header {
401 u16 pages; /* Number of allocated pages */
402 kmemcheck_bitfield_begin(meta);
403 u16 jited:1, /* Is our filter JIT'ed? */
404 gpl_compatible:1, /* Is filter GPL compatible? */
405 cb_access:1, /* Is control block accessed? */
406 dst_needed:1, /* Do we need dst entry? */
407 xdp_adjust_head:1; /* Adjusting pkt head? */
408 kmemcheck_bitfield_end(meta);
409 enum bpf_prog_type type; /* Type of BPF program */
410 u32 len; /* Number of filter blocks */
411 u32 digest[SHA_DIGEST_WORDS]; /* Program digest */
412 struct bpf_prog_aux *aux; /* Auxiliary fields */
413 struct sock_fprog_kern *orig_prog; /* Original BPF program */
414 unsigned int (*bpf_func)(const void *ctx,
415 const struct bpf_insn *insn);
416 /* Instructions for interpreter */
418 struct sock_filter insns[0];
419 struct bpf_insn insnsi[0];
426 struct bpf_prog *prog;
429 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
431 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
433 struct bpf_skb_data_end {
434 struct qdisc_skb_cb qdisc_cb;
441 void *data_hard_start;
444 /* compute the linear packet data range [data, data_end) which
445 * will be accessed by cls_bpf, act_bpf and lwt programs
447 static inline void bpf_compute_data_end(struct sk_buff *skb)
449 struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
451 BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
452 cb->data_end = skb->data + skb_headlen(skb);
455 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
457 /* eBPF programs may read/write skb->cb[] area to transfer meta
458 * data between tail calls. Since this also needs to work with
459 * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
461 * In some socket filter cases, the cb unfortunately needs to be
462 * saved/restored so that protocol specific skb->cb[] data won't
463 * be lost. In any case, due to unpriviledged eBPF programs
464 * attached to sockets, we need to clear the bpf_skb_cb() area
465 * to not leak previous contents to user space.
467 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
468 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
469 FIELD_SIZEOF(struct qdisc_skb_cb, data));
471 return qdisc_skb_cb(skb)->data;
474 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
477 u8 *cb_data = bpf_skb_cb(skb);
478 u8 cb_saved[BPF_SKB_CB_LEN];
481 if (unlikely(prog->cb_access)) {
482 memcpy(cb_saved, cb_data, sizeof(cb_saved));
483 memset(cb_data, 0, sizeof(cb_saved));
486 res = BPF_PROG_RUN(prog, skb);
488 if (unlikely(prog->cb_access))
489 memcpy(cb_data, cb_saved, sizeof(cb_saved));
494 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
497 u8 *cb_data = bpf_skb_cb(skb);
499 if (unlikely(prog->cb_access))
500 memset(cb_data, 0, BPF_SKB_CB_LEN);
502 return BPF_PROG_RUN(prog, skb);
505 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
506 struct xdp_buff *xdp)
508 /* Caller needs to hold rcu_read_lock() (!), otherwise program
509 * can be released while still running, or map elements could be
510 * freed early while still having concurrent users. XDP fastpath
511 * already takes rcu_read_lock() when fetching the program, so
512 * it's not necessary here anymore.
514 return BPF_PROG_RUN(prog, xdp);
517 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
519 return prog->len * sizeof(struct bpf_insn);
522 static inline u32 bpf_prog_digest_scratch_size(const struct bpf_prog *prog)
524 return round_up(bpf_prog_insn_size(prog) +
525 sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
528 static inline unsigned int bpf_prog_size(unsigned int proglen)
530 return max(sizeof(struct bpf_prog),
531 offsetof(struct bpf_prog, insns[proglen]));
534 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
536 /* When classic BPF programs have been loaded and the arch
537 * does not have a classic BPF JIT (anymore), they have been
538 * converted via bpf_migrate_filter() to eBPF and thus always
539 * have an unspec program type.
541 return prog->type == BPF_PROG_TYPE_UNSPEC;
544 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
546 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
547 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
549 set_memory_ro((unsigned long)fp, fp->pages);
552 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
554 set_memory_rw((unsigned long)fp, fp->pages);
557 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
561 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
564 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */
566 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
567 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
569 return sk_filter_trim_cap(sk, skb, 1);
572 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
573 void bpf_prog_free(struct bpf_prog *fp);
575 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
576 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
577 gfp_t gfp_extra_flags);
578 void __bpf_prog_free(struct bpf_prog *fp);
580 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
582 bpf_prog_unlock_ro(fp);
586 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
589 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
590 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
591 bpf_aux_classic_check_t trans, bool save_orig);
592 void bpf_prog_destroy(struct bpf_prog *fp);
594 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
595 int sk_attach_bpf(u32 ufd, struct sock *sk);
596 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
597 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
598 int sk_detach_filter(struct sock *sk);
599 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
602 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
603 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
605 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
607 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
608 bool bpf_helper_changes_pkt_data(void *func);
610 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
611 const struct bpf_insn *patch, u32 len);
612 void bpf_warn_invalid_xdp_action(u32 act);
613 void bpf_warn_invalid_xdp_buffer(void);
615 #ifdef CONFIG_BPF_JIT
616 extern int bpf_jit_enable;
617 extern int bpf_jit_harden;
619 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
621 struct bpf_binary_header *
622 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
623 unsigned int alignment,
624 bpf_jit_fill_hole_t bpf_fill_ill_insns);
625 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
627 void bpf_jit_compile(struct bpf_prog *fp);
628 void bpf_jit_free(struct bpf_prog *fp);
630 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
631 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
633 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
634 u32 pass, void *image)
636 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
637 proglen, pass, image, current->comm, task_pid_nr(current));
640 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
641 16, 1, image, proglen, false);
644 static inline bool bpf_jit_is_ebpf(void)
646 # ifdef CONFIG_HAVE_EBPF_JIT
653 static inline bool bpf_jit_blinding_enabled(void)
655 /* These are the prerequisites, should someone ever have the
656 * idea to call blinding outside of them, we make sure to
659 if (!bpf_jit_is_ebpf())
665 if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
671 static inline void bpf_jit_compile(struct bpf_prog *fp)
675 static inline void bpf_jit_free(struct bpf_prog *fp)
677 bpf_prog_unlock_free(fp);
679 #endif /* CONFIG_BPF_JIT */
681 #define BPF_ANC BIT(15)
683 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
685 switch (first->code) {
686 case BPF_RET | BPF_K:
687 case BPF_LD | BPF_W | BPF_LEN:
690 case BPF_LD | BPF_W | BPF_ABS:
691 case BPF_LD | BPF_H | BPF_ABS:
692 case BPF_LD | BPF_B | BPF_ABS:
693 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
702 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
704 BUG_ON(ftest->code & BPF_ANC);
706 switch (ftest->code) {
707 case BPF_LD | BPF_W | BPF_ABS:
708 case BPF_LD | BPF_H | BPF_ABS:
709 case BPF_LD | BPF_B | BPF_ABS:
710 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
711 return BPF_ANC | SKF_AD_##CODE
713 BPF_ANCILLARY(PROTOCOL);
714 BPF_ANCILLARY(PKTTYPE);
715 BPF_ANCILLARY(IFINDEX);
716 BPF_ANCILLARY(NLATTR);
717 BPF_ANCILLARY(NLATTR_NEST);
719 BPF_ANCILLARY(QUEUE);
720 BPF_ANCILLARY(HATYPE);
721 BPF_ANCILLARY(RXHASH);
723 BPF_ANCILLARY(ALU_XOR_X);
724 BPF_ANCILLARY(VLAN_TAG);
725 BPF_ANCILLARY(VLAN_TAG_PRESENT);
726 BPF_ANCILLARY(PAY_OFFSET);
727 BPF_ANCILLARY(RANDOM);
728 BPF_ANCILLARY(VLAN_TPID);
736 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
737 int k, unsigned int size);
739 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
740 unsigned int size, void *buffer)
743 return skb_header_pointer(skb, k, size, buffer);
745 return bpf_internal_load_pointer_neg_helper(skb, k, size);
748 static inline int bpf_tell_extensions(void)
753 #endif /* __LINUX_FILTER_H__ */