bpf: Sanitize the bpf_struct_ops tcp-cc name

The bpf_struct_ops tcp-cc name should be sanitized in order to
avoid problematic chars (e.g. whitespaces).

This patch reuses the bpf_obj_name_cpy() for accepting the same set
of characters in order to keep a consistent bpf programming experience.
A "size" param is added.  Also, the strlen is returned on success so
that the caller (like the bpf_tcp_ca here) can error out on empty name.
The existing callers of the bpf_obj_name_cpy() only need to change the
testing statement to "if (err < 0)".  For all these existing callers,
the err will be overwritten later, so no extra change is needed
for the new strlen return value.

v3:
  - reverse xmas tree style
v2:
  - Save the orig_src to avoid "end - size" (Andrii)

Fixes: 0baf26b0fc ("bpf: tcp: Support tcp_congestion_ops in bpf")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200314010209.1131542-1-kafai@fb.com
This commit is contained in:
Martin KaFai Lau 2020-03-13 18:02:09 -07:00 committed by Daniel Borkmann
parent 32ca98feab
commit 8e7ae2518f
3 changed files with 17 additions and 16 deletions

View file

@ -160,6 +160,7 @@ static inline void copy_map_value(struct bpf_map *map, void *dst, void *src)
}
void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
bool lock_src);
int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size);
struct bpf_offload_dev;
struct bpf_offloaded_map;