# \[PATCH v2 bpf-next 01/11\] libbpf: expose btf\_type\_by\_id() internally

- From: Andrii Nakryiko \<andrii@kernel.org\>
- Date: 2021-03-13 19:36:45 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/03/7762534
- Thread: https://ratatoskr.run/bpf/2021/03/7762535/t.md

```text
btf_type_by_id() is internal-only convenience API returning non-const pointer
to struct btf_type. Expose it outside of btf.c for re-use.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/btf.c             | 2 +-
 tools/lib/bpf/libbpf_internal.h | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 3aa58f2ac183..e0b0a78b04fe 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -435,7 +435,7 @@ const struct btf *btf__base_btf(const struct btf *btf)
 }
 
 /* internal helper returning non-const pointer to a type */
-static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)
+struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)
 {
 	if (type_id == 0)
 		return &btf_void;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 343f6eb05637..d09860e435c8 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -107,6 +107,11 @@ static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size)
 	return realloc(ptr, total);
 }
 
+struct btf;
+struct btf_type;
+
+struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id);
+
 void *btf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz,
 		  size_t cur_cnt, size_t max_cnt, size_t add_cnt);
 int btf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt);
-- 
2.24.1

```