diff --git a/tools/gtpnl.c b/tools/gtpnl.c
new file mode 100644
index 0000000..6b2f1e2
--- /dev/null
+++ b/tools/gtpnl.c
@@ -0,0 +1,13 @@
+#include <stdint.h>
+#include <libmnl/libmnl.h>
+#include <linux/gtp_nl.h>
+
+void gtp_build_payload(struct nlmsghdr *nlh, uint64_t tid, uint32_t ifidx,
+		       uint32_t sgsn_addr, uint32_t ms_addr, uint32_t version)
+{
+	mnl_attr_put_u32(nlh, GTPA_VERSION, version);
+	mnl_attr_put_u32(nlh, GTPA_LINK, ifidx);
+	mnl_attr_put_u32(nlh, GTPA_SGSN_ADDRESS, sgsn_addr);
+	mnl_attr_put_u32(nlh, GTPA_MS_ADDRESS, ms_addr);
+	mnl_attr_put_u64(nlh, GTPA_TID, tid);
+}