[PATCH bpf-next] bpf: show in bpftool map overview whether btf is available

[Daniel Borkmann <daniel@iogearbox.net>]

For a quick overview in 'bpftool map' display 'btf' if it's
available for the dump for a specific map:

  # bpftool map list
  11: array  flags 0x0  btf
          key 4B  value 20B  max_entries 40  memlock 4096B

  # bpftool --json --pretty map list
  [{
          "id": 11,
          "type": "array",
          "flags": 0,
          "btf_available": true,
          "bytes_key": 4,
          "bytes_value": 20,
          "max_entries": 40,
          "bytes_memlock": 4096
      }
  ]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 tools/bpf/bpftool/map.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 9c81918..2cc4741 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -490,6 +490,8 @@ static int show_map_close_json(int fd, struct bpf_map_info *info)
 
 	jsonw_name(json_wtr, "flags");
 	jsonw_printf(json_wtr, "%d", info->map_flags);
+	jsonw_name(json_wtr, "btf_available");
+	jsonw_bool(json_wtr, info->btf_key_type_id && info->btf_value_type_id);
 
 	print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
 
@@ -535,6 +537,8 @@ static int show_map_close_plain(int fd, struct bpf_map_info *info)
 		printf("name %s  ", info->name);
 
 	printf("flags 0x%x", info->map_flags);
+	if (info->btf_key_type_id && info->btf_value_type_id)
+		printf("  btf");
 	print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 	printf("\n");
 	printf("\tkey %uB  value %uB  max_entries %u",
-- 
2.9.5