diff --git a/src/gtp-rtnl.c b/src/gtp-rtnl.c
index a48fa1c..72a2870 100644
--- a/src/gtp-rtnl.c
+++ b/src/gtp-rtnl.c
@@ -15,33 +15,24 @@
 
 #include "internal.h"
 
-int gtp_dev_create(const char *ifname)
+static struct nlmsghdr *
+gtp_put_nlmsg(char *buf, uint16_t type, uint16_t nl_flags, uint32_t seq)
+{
+	struct nlmsghdr *nlh;
+
+	nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type	= type;
+	nlh->nlmsg_flags = NLM_F_REQUEST | nl_flags;
+	nlh->nlmsg_seq = seq;
+
+	return nlh;
+}
+
+static int gtp_dev_talk(struct nlmsghdr *nlh, uint32_t seq)
 {
 	struct mnl_socket *nl;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
-	struct nlmsghdr *nlh;
-	struct ifinfomsg *ifm;
 	int ret;
-	unsigned int seq, portid;
-	struct nlattr *nest, *nest2;
-
-	nlh = mnl_nlmsg_put_header(buf);
-	nlh->nlmsg_type	= RTM_NEWLINK;
-	nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK;
-	nlh->nlmsg_seq = seq = time(NULL);
-	ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm));
-	ifm->ifi_family = AF_INET;
-	ifm->ifi_change |= IFF_UP;
-	ifm->ifi_flags |= IFF_UP;
-
-	mnl_attr_put_u32(nlh, IFLA_LINK, if_nametoindex(ifname));
-	nest = mnl_attr_nest_start(nlh, IFLA_LINKINFO);
-	mnl_attr_put_str(nlh, IFLA_INFO_KIND, "gtp");
-	nest2 = mnl_attr_nest_start(nlh, IFLA_INFO_DATA);
-	mnl_attr_put_u32(nlh, IFLA_GTP_LOCAL_ADDR_IPV4, 0);
-	mnl_attr_put_u32(nlh, IFLA_GTP_HASHSIZE, 131072);
-	mnl_attr_nest_end(nlh, nest2);
-	mnl_attr_nest_end(nlh, nest);
 
 	nl = mnl_socket_open(NETLINK_ROUTE);
 	if (nl == NULL) {
@@ -53,7 +44,6 @@
 		perror("mnl_socket_bind");
 		goto err;
 	}
-	portid = mnl_socket_get_portid(nl);
 
 	mnl_nlmsg_fprintf(stdout, nlh, nlh->nlmsg_len,
 			  sizeof(struct ifinfomsg));
@@ -69,7 +59,7 @@
 		goto err;
 	}
 
-	ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
+	ret = mnl_cb_run(buf, ret, seq, mnl_socket_get_portid(nl), NULL, NULL);
 	if (ret == -1){
 		perror("callback");
 		goto err;
@@ -81,4 +71,30 @@
 	mnl_socket_close(nl);
 	return -1;
 }
+
+int gtp_dev_create(const char *ifname)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct ifinfomsg *ifm;
+	unsigned int seq = time(NULL);
+	struct nlattr *nest, *nest2;
+
+	nlh = gtp_put_nlmsg(buf, RTM_NEWLINK, NLM_F_CREATE | NLM_F_ACK, seq);
+	ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm));
+	ifm->ifi_family = AF_INET;
+	ifm->ifi_change |= IFF_UP;
+	ifm->ifi_flags |= IFF_UP;
+
+	mnl_attr_put_u32(nlh, IFLA_LINK, if_nametoindex(ifname));
+	nest = mnl_attr_nest_start(nlh, IFLA_LINKINFO);
+	mnl_attr_put_str(nlh, IFLA_INFO_KIND, "gtp");
+	nest2 = mnl_attr_nest_start(nlh, IFLA_INFO_DATA);
+	mnl_attr_put_u32(nlh, IFLA_GTP_LOCAL_ADDR_IPV4, 0);
+	mnl_attr_put_u32(nlh, IFLA_GTP_HASHSIZE, 131072);
+	mnl_attr_nest_end(nlh, nest2);
+	mnl_attr_nest_end(nlh, nest);
+
+	return gtp_dev_talk(nlh, seq);
+}
 EXPORT_SYMBOL(gtp_dev_create);