[PATCH bpf-next 7/8] bpftool: Support link show for netns-attached links

[Jakub Sitnicki <jakub@cloudflare.com>]

Make `bpf link show` aware of new link type, that is links attached to
netns. When listing netns-attached links, display netns inode number as its
identifier and link attach type.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 tools/bpf/bpftool/link.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index 670a561dc31b..83a17d62c4c3 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -17,6 +17,7 @@ static const char * const link_type_name[] = {
 	[BPF_LINK_TYPE_TRACING]			= "tracing",
 	[BPF_LINK_TYPE_CGROUP]			= "cgroup",
 	[BPF_LINK_TYPE_ITER]			= "iter",
+	[BPF_LINK_TYPE_NETNS]			= "netns",
 };
 
 static int link_parse_fd(int *argc, char ***argv)
@@ -122,6 +123,16 @@ static int show_link_close_json(int fd, struct bpf_link_info *info)
 			jsonw_uint_field(json_wtr, "attach_type",
 					 info->cgroup.attach_type);
 		break;
+	case BPF_LINK_TYPE_NETNS:
+		jsonw_uint_field(json_wtr, "netns_ino",
+				 info->netns.netns_ino);
+		if (info->netns.attach_type < ARRAY_SIZE(attach_type_name))
+			jsonw_string_field(json_wtr, "attach_type",
+				attach_type_name[info->netns.attach_type]);
+		else
+			jsonw_uint_field(json_wtr, "attach_type",
+					 info->netns.attach_type);
+		break;
 	default:
 		break;
 	}
@@ -190,6 +201,14 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info)
 		else
 			printf("attach_type %u  ", info->cgroup.attach_type);
 		break;
+	case BPF_LINK_TYPE_NETNS:
+		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
+		if (info->netns.attach_type < ARRAY_SIZE(attach_type_name))
+			printf("attach_type %s  ",
+			       attach_type_name[info->netns.attach_type]);
+		else
+			printf("attach_type %u  ", info->netns.attach_type);
+		break;
 	default:
 		break;
 	}
-- 
2.25.4