Merge branch 'bpf_link-observability'

Andrii Nakryiko says:

====================
This patch series adds various observability APIs to bpf_link:
  - each bpf_link now gets ID, similar to bpf_map and bpf_prog, by which
    user-space can iterate over all existing bpf_links and create limited FD
    from ID;
  - allows to get extra object information with bpf_link general and
    type-specific information;
  - implements `bpf link show` command which lists all active bpf_links in the
    system;
  - implements `bpf link pin` allowing to pin bpf_link by ID or from other
    pinned path.

v2->v3:
  - improve spin locking around bpf_link ID (Alexei);
  - simplify bpf_link_info handling and fix compilation error on sh arch;
v1->v2:
  - simplified `bpftool link show` implementation (Quentin);
  - fixed formatting of bpftool-link.rst (Quentin);
  - fixed attach type printing logic (Quentin);
rfc->v1:
  - dropped read-only bpf_links (Alexei);
  - fixed bug in bpf_link_cleanup() not removing ID;
  - fixed bpftool link pinning search logic;
  - added bash-completion and man page.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 15 insertions, 33 deletions

diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
index 62c6a1d7cd18..1693c802bb20 100644
--- a/tools/bpf/bpftool/cgroup.c
+++ b/tools/bpf/bpftool/cgroup.c
@@ -31,42 +31,20 @@
 
 static unsigned int query_flags;
 
-static const char * const attach_type_strings[] = {
-	[BPF_CGROUP_INET_INGRESS] = "ingress",
-	[BPF_CGROUP_INET_EGRESS] = "egress",
-	[BPF_CGROUP_INET_SOCK_CREATE] = "sock_create",
-	[BPF_CGROUP_SOCK_OPS] = "sock_ops",
-	[BPF_CGROUP_DEVICE] = "device",
-	[BPF_CGROUP_INET4_BIND] = "bind4",
-	[BPF_CGROUP_INET6_BIND] = "bind6",
-	[BPF_CGROUP_INET4_CONNECT] = "connect4",
-	[BPF_CGROUP_INET6_CONNECT] = "connect6",
-	[BPF_CGROUP_INET4_POST_BIND] = "post_bind4",
-	[BPF_CGROUP_INET6_POST_BIND] = "post_bind6",
-	[BPF_CGROUP_UDP4_SENDMSG] = "sendmsg4",
-	[BPF_CGROUP_UDP6_SENDMSG] = "sendmsg6",
-	[BPF_CGROUP_SYSCTL] = "sysctl",
-	[BPF_CGROUP_UDP4_RECVMSG] = "recvmsg4",
-	[BPF_CGROUP_UDP6_RECVMSG] = "recvmsg6",
-	[BPF_CGROUP_GETSOCKOPT] = "getsockopt",
-	[BPF_CGROUP_SETSOCKOPT] = "setsockopt",
-	[__MAX_BPF_ATTACH_TYPE] = NULL,
-};
-
 static enum bpf_attach_type parse_attach_type(const char *str)
 {
 	enum bpf_attach_type type;
 
 	for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
-		if (attach_type_strings[type] &&
-		    is_prefix(str, attach_type_strings[type]))
+		if (attach_type_name[type] &&
+		    is_prefix(str, attach_type_name[type]))
 			return type;
 	}
 
 	return __MAX_BPF_ATTACH_TYPE;
 }
 
-static int show_bpf_prog(int id, const char *attach_type_str,
+static int show_bpf_prog(int id, enum bpf_attach_type attach_type,
 			 const char *attach_flags_str,
 			 int level)
 {
@@ -86,18 +64,22 @@ static int show_bpf_prog(int id, const char *attach_type_str,
 	if (json_output) {
 		jsonw_start_object(json_wtr);
 		jsonw_uint_field(json_wtr, "id", info.id);
-		jsonw_string_field(json_wtr, "attach_type",
-				   attach_type_str);
+		if (attach_type < ARRAY_SIZE(attach_type_name))
+			jsonw_string_field(json_wtr, "attach_type",
+					   attach_type_name[attach_type]);
+		else
+			jsonw_uint_field(json_wtr, "attach_type", attach_type);
 		jsonw_string_field(json_wtr, "attach_flags",
 				   attach_flags_str);
 		jsonw_string_field(json_wtr, "name", info.name);
 		jsonw_end_object(json_wtr);
 	} else {
-		printf("%s%-8u %-15s %-15s %-15s\n", level ? "    " : "",
-		       info.id,
-		       attach_type_str,
-		       attach_flags_str,
-		       info.name);
+		printf("%s%-8u ", level ? "    " : "", info.id);
+		if (attach_type < ARRAY_SIZE(attach_type_name))
+			printf("%-15s", attach_type_name[attach_type]);
+		else
+			printf("type %-10u", attach_type);
+		printf(" %-15s %-15s\n", attach_flags_str, info.name);
 	}
 
 	close(prog_fd);
@@ -171,7 +153,7 @@ static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
 	}
 
 	for (iter = 0; iter < prog_cnt; iter++)
-		show_bpf_prog(prog_ids[iter], attach_type_strings[type],
+		show_bpf_prog(prog_ids[iter], type,
 			      attach_flags_str, level);
 
 	return 0;