libbpf: introduce bpf_map_lookup_elem_flags()

Introduce int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) helper to lookup array/hash/cgroup_local_storage elements with BPF_F_LOCK flag. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
mariux64 · Feb 1, 2019 · df5d22f · df5d22f
1 parent e44ac9a
commit df5d22f
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diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
@@ -368,6 +368,19 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value)
 	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
 }
 
+int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+	attr.flags = flags;
+
+	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
+}
+
 int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
 {
 	union bpf_attr attr;

diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
@@ -110,6 +110,8 @@ LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value,
 				   __u64 flags);
 
 LIBBPF_API int bpf_map_lookup_elem(int fd, const void *key, void *value);
+LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value,
+					 __u64 flags);
 LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
 					      void *value);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);

diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
@@ -130,4 +130,5 @@ LIBBPF_0.0.2 {
 		bpf_probe_helper;
 		bpf_probe_map_type;
 		bpf_probe_prog_type;
+		bpf_map_lookup_elem_flags;
 } LIBBPF_0.0.1;