bpftool: Use libbpf_bpf_attach_type_str

This change switches bpftool over to using the recently introduced
libbpf_bpf_attach_type_str function instead of maintaining its own
string representation for the bpf_attach_type enum.

Note that contrary to other enum types, the variant names that bpftool
maps bpf_attach_type to do not adhere a simple to follow rule. With
bpf_prog_type, for example, the textual representation can easily be
inferred by stripping the BPF_PROG_TYPE_ prefix and lowercasing the
remaining string. bpf_attach_type violates this rule for various
variants.
We decided to fix up this deficiency with this change, meaning that
bpftool uses the same textual representations as libbpf. Supporting
tests, completion scripts, and man pages have been adjusted accordingly.
However, we did add support for accepting (the now undocumented)
original attach type names when they are provided by users.

For the test (test_bpftool_synctypes.py), I have removed the enum
representation checks, because we no longer mirror the various enum
variant names in bpftool source code. For the man page, help text, and
completion script checks we are now using enum definitions from
uapi/linux/bpf.h as the source of truth directly.

Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-10-deso@posteo.net

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index e4fdaa0740b3..6c311f47147e 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -243,6 +243,20 @@ int print_all_levels(__maybe_unused enum libbpf_print_level level,
 size_t hash_fn_for_key_as_id(const void *key, void *ctx);
 bool equal_fn_for_key_as_id(const void *k1, const void *k2, void *ctx);
 
+/* bpf_attach_type_input_str - convert the provided attach type value into a
+ * textual representation that we accept for input purposes.
+ *
+ * This function is similar in nature to libbpf_bpf_attach_type_str, but
+ * recognizes some attach type names that have been used by the program in the
+ * past and which do not follow the string inference scheme that libbpf uses.
+ * These textual representations should only be used for user input.
+ *
+ * @t: The attach type
+ * Returns a pointer to a static string identifying the attach type. NULL is
+ * returned for unknown bpf_attach_type values.
+ */
+const char *bpf_attach_type_input_str(enum bpf_attach_type t);
+
 static inline void *u32_as_hash_field(__u32 x)
 {
 	return (void *)(uintptr_t)x;