[PATCH 07/10] bpf tools: Support BPF_OBJ_PIN and BPF_OBJ_GET

[Wang Nan <wangnan0@huawei.com>]

Commit b2197755b2633e164a439682fb05a9b5ea48f706 ("bpf: add support for
persistent maps/progs") introduces two new operations to both map and
program. This patch makes libbpf support it.

Signed-off-by: Wang Nan <wangnan0@hauwei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
---
 tools/lib/bpf/bpf.c | 21 +++++++++++++++++++++
 tools/lib/bpf/bpf.h |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 89c9d0b..5f174c6 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -129,3 +129,24 @@ int bpf_map_get_next_key(int fd, void *key, void *next_key)
 
 	return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
 }
+
+int bpf_pin_object(int fd, const char *pathname)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.pathname = ptr_to_u64((void *)pathname);
+	attr.bpf_fd = fd;
+
+	return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
+}
+
+int bpf_get_pinned_object(const char *pathname)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.pathname = ptr_to_u64((void *)pathname);
+
+	return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 3d22048..c9f1a1c 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -27,4 +27,7 @@ int bpf_map_update_elem(int fd, void *key, void *value,
 int bpf_map_lookup_elem(int fd, void *key, void *value);
 int bpf_map_delete_elem(int fd, void *key);
 int bpf_map_get_next_key(int fd, void *key, void *next_key);
+
+int bpf_pin_object(int fd, const char *pathname);
+int bpf_get_pinned_object(const char *pathname);
 #endif
-- 
1.8.3.4