[PATCH bpf-next 2/2] libbpf: support new uapi for map element bpf iterator

[Yonghong Song <yhs@fb.com>]

Previous commit adjusted kernel uapi for map
element bpf iterator. This patch adjusted libbpf API
due to uapi change.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/bpf.c    | 4 +++-
 tools/lib/bpf/bpf.h    | 5 +++--
 tools/lib/bpf/libbpf.c | 7 +++++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index eab14c97c15d..c75a84398d51 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -598,7 +598,9 @@ int bpf_link_create(int prog_fd, int target_fd,
 	attr.link_create.prog_fd = prog_fd;
 	attr.link_create.target_fd = target_fd;
 	attr.link_create.attach_type = attach_type;
-	attr.link_create.flags = OPTS_GET(opts, flags, 0);
+	attr.link_create.iter_info =
+		ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
+	attr.link_create.iter_info_len = OPTS_GET(opts, iter_info_len, 0);
 
 	return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
 }
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 28855fd5b5f4..c9895f191305 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -170,9 +170,10 @@ LIBBPF_API int bpf_prog_detach2(int prog_fd, int attachable_fd,
 
 struct bpf_link_create_opts {
 	size_t sz; /* size of this struct for forward/backward compatibility */
-	__u32 flags;
+	union bpf_iter_link_info *iter_info;
+	__u32 iter_info_len;
 };
-#define bpf_link_create_opts__last_field flags
+#define bpf_link_create_opts__last_field iter_info_len
 
 LIBBPF_API int bpf_link_create(int prog_fd, int target_fd,
 			       enum bpf_attach_type attach_type,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7be04e45d29c..dc8fabf9d30d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8298,6 +8298,7 @@ bpf_program__attach_iter(struct bpf_program *prog,
 			 const struct bpf_iter_attach_opts *opts)
 {
 	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
+	union bpf_iter_link_info linfo;
 	char errmsg[STRERR_BUFSIZE];
 	struct bpf_link *link;
 	int prog_fd, link_fd;
@@ -8307,8 +8308,10 @@ bpf_program__attach_iter(struct bpf_program *prog,
 		return ERR_PTR(-EINVAL);
 
 	if (OPTS_HAS(opts, map_fd)) {
-		target_fd = opts->map_fd;
-		link_create_opts.flags = BPF_ITER_LINK_MAP_FD;
+		memset(&linfo, 0, sizeof(linfo));
+		linfo.map.map_fd = opts->map_fd;
+		link_create_opts.iter_info = &linfo;
+		link_create_opts.iter_info_len = sizeof(linfo);
 	}
 
 	prog_fd = bpf_program__fd(prog);
-- 
2.24.1