libbpf: implement bpf_prog_query_opts

Implement bpf_prog_query_opts as a more expendable version of
bpf_prog_query. Expose new prog_attach_flags and attach_btf_func_id as
well:

* prog_attach_flags is a per-program attach_type; relevant only for
  lsm cgroup program which might have different attach_flags
  per attach_btf_id
* attach_btf_func_id is a new field expose for prog_query which
  specifies real btf function id for lsm cgroup attachments

Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220628174314.1216643-10-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 31 insertions, 7 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 6d848b02c1e0..5eb0df90eb2b 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -795,24 +795,48 @@ int bpf_iter_create(int link_fd)
 	return libbpf_err_errno(fd);
 }
 
-int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
-		   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
+int bpf_prog_query_opts(int target_fd,
+			enum bpf_attach_type type,
+			struct bpf_prog_query_opts *opts)
 {
 	union bpf_attr attr;
 	int ret;
 
+	if (!OPTS_VALID(opts, bpf_prog_query_opts))
+		return libbpf_err(-EINVAL);
+
 	memset(&attr, 0, sizeof(attr));
+
 	attr.query.target_fd	= target_fd;
 	attr.query.attach_type	= type;
-	attr.query.query_flags	= query_flags;
-	attr.query.prog_cnt	= *prog_cnt;
-	attr.query.prog_ids	= ptr_to_u64(prog_ids);
+	attr.query.query_flags	= OPTS_GET(opts, query_flags, 0);
+	attr.query.prog_cnt	= OPTS_GET(opts, prog_cnt, 0);
+	attr.query.prog_ids	= ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
+	attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
 
 	ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
 
+	OPTS_SET(opts, attach_flags, attr.query.attach_flags);
+	OPTS_SET(opts, prog_cnt, attr.query.prog_cnt);
+
+	return libbpf_err_errno(ret);
+}
+
+int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
+		   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
+{
+	LIBBPF_OPTS(bpf_prog_query_opts, opts);
+	int ret;
+
+	opts.query_flags = query_flags;
+	opts.prog_ids = prog_ids;
+	opts.prog_cnt = *prog_cnt;
+
+	ret = bpf_prog_query_opts(target_fd, type, &opts);
+
 	if (attach_flags)
-		*attach_flags = attr.query.attach_flags;
-	*prog_cnt = attr.query.prog_cnt;
+		*attach_flags = opts.attach_flags;
+	*prog_cnt = opts.prog_cnt;
 
 	return libbpf_err_errno(ret);
 }