tools lib bpf: Add flags to bpf_create_map()

Commit 6c905981743 ("bpf: pre-allocate hash map elements") introduces
map_flags to bpf_attr for BPF_MAP_CREATE command. Expose this new
parameter in libbpf.

By exposing it, users can access flags such as whether or not to
preallocate the map.

Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: http://lkml.kernel.org/r/20161209024620.31660-4-joe@ovn.org
[ Added clarifying comment made by Wang Nan ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 89e8e8e5b60e..d0afb26c2e0f 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -54,7 +54,7 @@ static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
 }
 
 int bpf_create_map(enum bpf_map_type map_type, int key_size,
-                   int value_size, int max_entries)
+                   int value_size, int max_entries, __u32 map_flags)
 {
         union bpf_attr attr;
 
@@ -64,6 +64,7 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size,
         attr.key_size = key_size;
         attr.value_size = value_size;
         attr.max_entries = max_entries;
+        attr.map_flags = map_flags;
 
         return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
 }