Move kernel GTP support from ggsn/ to lib/

This way, the IP address / route handling between TUN devices and kernel
GTP can be shared, which will provide not only a unified codebase but
also a more consistent behavior.

This also paves the road for to use kernel GTP from sgsnemu in the future.

Related: OS#3214
Change-Id: Ic53a971136edd0d8871fbd6746d7b0090ce3a188

9 files changed, 151 insertions, 148 deletions

diff --git a/ggsn/Makefile.am b/ggsn/Makefile.am
index 6b2232f..eca385f 100644
--- a/ggsn/Makefile.am
+++ b/ggsn/Makefile.am
@@ -12,8 +12,4 @@ osmo_ggsn_LDADD += $(LIBGTPNL_LIBS)
 endif
 
 osmo_ggsn_DEPENDENCIES = ../gtp/libgtp.la ../lib/libmisc.a
-osmo_ggsn_SOURCES = ggsn_vty.c ggsn.c ggsn.h gtp-kernel.h icmpv6.c icmpv6.h checksum.c checksum.h
-
-if ENABLE_GTP_KERNEL
-osmo_ggsn_SOURCES += gtp-kernel.c
-endif
+osmo_ggsn_SOURCES = ggsn_vty.c ggsn.c ggsn.h icmpv6.c icmpv6.h checksum.c checksum.h
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index 85a2211..4636c04 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -63,9 +63,9 @@
 #include "../lib/ippool.h"
 #include "../lib/syserr.h"
 #include "../lib/in46_addr.h"
+#include "../lib/gtp-kernel.h"
 #include "../gtp/pdp.h"
 #include "../gtp/gtp.h"
-#include "gtp-kernel.h"
 #include "icmpv6.h"
 #include "ggsn.h"
 
@@ -125,13 +125,14 @@ int apn_stop(struct apn_ctx *apn, bool force)
 			LOGPAPN( LOGL_INFO, apn, "Running %s\n", apn->tun.cfg.ipdown_script);
 			tun_runscript(apn->tun.tun, apn->tun.cfg.ipdown_script);
 		}
-		/* release tun device */
-		LOGPAPN(LOGL_INFO, apn, "Closing TUN device %s\n", apn->tun.tun->devname);
-		osmo_fd_unregister(&apn->tun.fd);
+		if (apn->cfg.gtpu_mode == APN_GTPU_MODE_TUN) {
+			/* release tun device */
+			LOGPAPN(LOGL_INFO, apn, "Closing TUN device %s\n", apn->tun.tun->devname);
+			osmo_fd_unregister(&apn->tun.fd);
+		}
 		tun_free(apn->tun.tun);
 		apn->tun.tun = NULL;
 	}
-	gtp_kernel_stop(apn->tun.cfg.dev_name);
 
 	if (apn->v4.pool) {
 		LOGPAPN(LOGL_INFO, apn, "Releasing IPv4 pool\n");
@@ -195,6 +196,7 @@ int apn_start(struct apn_ctx *apn)
 	struct in46_prefix ipv6_tun_linklocal_ip;
 	struct in46_prefix *blacklist;
 	int blacklist_size;
+	struct gsn_t *gsn = apn->ggsn->gsn;
 	int rc;
 
 	if (apn->started)
@@ -204,7 +206,7 @@ int apn_start(struct apn_ctx *apn)
 	switch (apn->cfg.gtpu_mode) {
 	case APN_GTPU_MODE_TUN:
 		LOGPAPN(LOGL_INFO, apn, "Opening TUN device %s\n", apn->tun.cfg.dev_name);
-		if (tun_new(&apn->tun.tun, apn->tun.cfg.dev_name)) {
+		if (tun_new(&apn->tun.tun, apn->tun.cfg.dev_name, false, -1, -1)) {
 			LOGPAPN(LOGL_ERROR, apn, "Failed to configure tun device\n");
 			return -1;
 		}
@@ -216,66 +218,6 @@ int apn_start(struct apn_ctx *apn)
 
 		/* Set TUN library callback */
 		tun_set_cb_ind(apn->tun.tun, cb_tun_ind);
-
-		if (apn->v4.cfg.ifconfig_prefix.addr.len) {
-			LOGPAPN(LOGL_INFO, apn, "Setting tun IP address %s\n",
-				in46p_ntoa(&apn->v4.cfg.ifconfig_prefix));
-			if (tun_addaddr(apn->tun.tun, &apn->v4.cfg.ifconfig_prefix.addr, NULL,
-					apn->v4.cfg.ifconfig_prefix.prefixlen)) {
-				LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv4 address %s: %s\n",
-					in46p_ntoa(&apn->v4.cfg.ifconfig_prefix), strerror(errno));
-				apn_stop(apn, false);
-				return -1;
-			}
-		}
-
-		if (apn->v6.cfg.ifconfig_prefix.addr.len) {
-			LOGPAPN(LOGL_INFO, apn, "Setting tun IPv6 address %s\n",
-				in46p_ntoa(&apn->v6.cfg.ifconfig_prefix));
-			if (tun_addaddr(apn->tun.tun, &apn->v6.cfg.ifconfig_prefix.addr, NULL,
-					apn->v6.cfg.ifconfig_prefix.prefixlen)) {
-				LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv6 address %s: %s. "
-					"Ensure you have ipv6 support and not used the disable_ipv6 sysctl?\n",
-					in46p_ntoa(&apn->v6.cfg.ifconfig_prefix), strerror(errno));
-				apn_stop(apn, false);
-				return -1;
-			}
-		}
-
-		if (apn->v6.cfg.ll_prefix.addr.len) {
-			LOGPAPN(LOGL_INFO, apn, "Setting tun IPv6 link-local address %s\n",
-				in46p_ntoa(&apn->v6.cfg.ll_prefix));
-			if (tun_addaddr(apn->tun.tun, &apn->v6.cfg.ll_prefix.addr, NULL,
-					apn->v6.cfg.ll_prefix.prefixlen)) {
-				LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv6 link-local address %s: %s. "
-					"Ensure you have ipv6 support and not used the disable_ipv6 sysctl?\n",
-					in46p_ntoa(&apn->v6.cfg.ll_prefix), strerror(errno));
-				apn_stop(apn, false);
-				return -1;
-			}
-			apn->v6_lladdr = apn->v6.cfg.ll_prefix.addr.v6;
-		}
-
-		if (apn->tun.cfg.ipup_script) {
-			LOGPAPN(LOGL_INFO, apn, "Running ip-up script %s\n",
-				apn->tun.cfg.ipup_script);
-			tun_runscript(apn->tun.tun, apn->tun.cfg.ipup_script);
-		}
-
-		if (apn->cfg.apn_type_mask & (APN_TYPE_IPv6|APN_TYPE_IPv4v6) &&
-		    apn->v6.cfg.ll_prefix.addr.len == 0) {
-			rc = tun_ip_local_get(apn->tun.tun, &ipv6_tun_linklocal_ip, 1, IP_TYPE_IPv6_LINK);
-			if (rc < 1) {
-				LOGPAPN(LOGL_ERROR, apn, "Cannot obtain IPv6 link-local address of interface: %s\n",
-					rc ? strerror(errno) : "tun interface has no link-local IP assigned");
-				apn_stop(apn, false);
-				return -1;
-			}
-			apn->v6_lladdr = ipv6_tun_linklocal_ip.addr.v6;
-		}
-
-		/* set back-pointer from TUN device to APN */
-		apn->tun.tun->priv = apn;
 		break;
 	case APN_GTPU_MODE_KERNEL_GTP:
 		LOGPAPN(LOGL_INFO, apn, "Opening Kernel GTP device %s\n", apn->tun.cfg.dev_name);
@@ -284,7 +226,7 @@ int apn_start(struct apn_ctx *apn)
 			apn_stop(apn, false);
 			return -1;
 		}
-		if (apn->ggsn->gsn == NULL) {
+		if (gsn == NULL) {
 			/* skip bringing up the APN now if the GSN is not initialized yet.
 			 * This happens during initial load of the config file, as the
 			 * "no shutdown" in the ggsn node only happens after the "apn" nodes
@@ -293,8 +235,8 @@ int apn_start(struct apn_ctx *apn)
 			return 0;
 		}
 		/* use GTP kernel module for data packet encapsulation */
-		if (gtp_kernel_init(apn->ggsn->gsn, apn->tun.cfg.dev_name,
-				    &apn->v4.cfg.ifconfig_prefix, apn->tun.cfg.ipup_script) < 0) {
+		if (tun_new(&apn->tun.tun, apn->tun.cfg.dev_name, true, gsn->fd0, gsn->fd1u)) {
+			LOGPAPN(LOGL_ERROR, apn, "Failed to configure Kernel GTP device\n");
 			return -1;
 		}
 		break;
@@ -303,6 +245,68 @@ int apn_start(struct apn_ctx *apn)
 		return -1;
 	}
 
+	/* common initialization below */
+
+	/* set back-pointer from TUN device to APN */
+	apn->tun.tun->priv = apn;
+
+	if (apn->v4.cfg.ifconfig_prefix.addr.len) {
+		LOGPAPN(LOGL_INFO, apn, "Setting tun IP address %s\n",
+			in46p_ntoa(&apn->v4.cfg.ifconfig_prefix));
+		if (tun_addaddr(apn->tun.tun, &apn->v4.cfg.ifconfig_prefix.addr, NULL,
+				apn->v4.cfg.ifconfig_prefix.prefixlen)) {
+			LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv4 address %s: %s\n",
+				in46p_ntoa(&apn->v4.cfg.ifconfig_prefix), strerror(errno));
+			apn_stop(apn, false);
+			return -1;
+		}
+	}
+
+	if (apn->v6.cfg.ifconfig_prefix.addr.len) {
+		LOGPAPN(LOGL_INFO, apn, "Setting tun IPv6 address %s\n",
+			in46p_ntoa(&apn->v6.cfg.ifconfig_prefix));
+		if (tun_addaddr(apn->tun.tun, &apn->v6.cfg.ifconfig_prefix.addr, NULL,
+				apn->v6.cfg.ifconfig_prefix.prefixlen)) {
+			LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv6 address %s: %s. "
+				"Ensure you have ipv6 support and not used the disable_ipv6 sysctl?\n",
+				in46p_ntoa(&apn->v6.cfg.ifconfig_prefix), strerror(errno));
+			apn_stop(apn, false);
+			return -1;
+		}
+	}
+
+	if (apn->v6.cfg.ll_prefix.addr.len) {
+		LOGPAPN(LOGL_INFO, apn, "Setting tun IPv6 link-local address %s\n",
+			in46p_ntoa(&apn->v6.cfg.ll_prefix));
+		if (tun_addaddr(apn->tun.tun, &apn->v6.cfg.ll_prefix.addr, NULL,
+				apn->v6.cfg.ll_prefix.prefixlen)) {
+			LOGPAPN(LOGL_ERROR, apn, "Failed to set tun IPv6 link-local address %s: %s. "
+				"Ensure you have ipv6 support and not used the disable_ipv6 sysctl?\n",
+				in46p_ntoa(&apn->v6.cfg.ll_prefix), strerror(errno));
+			apn_stop(apn, false);
+			return -1;
+		}
+		apn->v6_lladdr = apn->v6.cfg.ll_prefix.addr.v6;
+	}
+
+	if (apn->tun.cfg.ipup_script) {
+		LOGPAPN(LOGL_INFO, apn, "Running ip-up script %s\n",
+			apn->tun.cfg.ipup_script);
+		tun_runscript(apn->tun.tun, apn->tun.cfg.ipup_script);
+	}
+
+	if (apn->cfg.apn_type_mask & (APN_TYPE_IPv6|APN_TYPE_IPv4v6) &&
+	    apn->v6.cfg.ll_prefix.addr.len == 0) {
+		rc = tun_ip_local_get(apn->tun.tun, &ipv6_tun_linklocal_ip, 1, IP_TYPE_IPv6_LINK);
+		if (rc < 1) {
+			LOGPAPN(LOGL_ERROR, apn, "Cannot obtain IPv6 link-local address of interface: %s\n",
+				rc ? strerror(errno) : "tun interface has no link-local IP assigned");
+			apn_stop(apn, false);
+			return -1;
+		}
+		apn->v6_lladdr = ipv6_tun_linklocal_ip.addr.v6;
+	}
+
 	/* Create IPv4 pool */
 	if (apn->v4.cfg.dynamic_prefix.addr.len) {
 		LOGPAPN(LOGL_INFO, apn, "Creating IPv4 pool %s\n",
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 55348ad..b6e7aba 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,7 +1,12 @@
 noinst_LIBRARIES = libmisc.a
 
-noinst_HEADERS = gnugetopt.h ippool.h lookup.h syserr.h tun.h in46_addr.h netdev.h
+noinst_HEADERS = gnugetopt.h ippool.h lookup.h syserr.h tun.h in46_addr.h netdev.h gtp-kernel.h
 
 AM_CFLAGS = -O2 -fno-builtin -Wall -DSBINDIR='"$(sbindir)"' -ggdb $(LIBOSMOCORE_CFLAGS)
 
 libmisc_a_SOURCES = getopt1.c getopt.c ippool.c lookup.c tun.c debug.c in46_addr.c netdev.c
+
+if ENABLE_GTP_KERNEL
+AM_CFLAGS += -DGTP_KERNEL $(LIBGTPNL_CFLAGS)
+libmisc_a_SOURCES += gtp-kernel.c
+endif
diff --git a/ggsn/gtp-kernel.c b/lib/gtp-kernel.c
index 4564d9a..48811bc 100644
--- a/ggsn/gtp-kernel.c
+++ b/lib/gtp-kernel.c
@@ -77,56 +77,20 @@ static int gtp_kernel_init_once(void)
 	return 0;
 }
 
-int gtp_kernel_init(struct gsn_t *gsn, const char *devname, struct in46_prefix *prefix, const char *ipup)
+int gtp_kernel_create(int dest_ns, const char *devname, int fd0, int fd1u)
 {
-	struct in_addr net;
-	const char *net_arg;
-
-	if (!gtp_nl.nl)
-		gtp_kernel_init_once();
-
-	if (prefix->addr.len != 4) {
-		LOGP(DGGSN, LOGL_ERROR, "we only support IPv4 in this path :/");
+	if (gtp_kernel_init_once() < 0)
 		return -1;
-	}
-	net = prefix->addr.v4;
-
-	if (gtp_dev_create(-1, devname, gsn->fd0, gsn->fd1u) < 0) {
-		LOGP(DGGSN, LOGL_ERROR, "cannot create GTP tunnel device: %s\n",
-			strerror(errno));
-		return -1;
-	}
-
-	net_arg = in46p_ntoa(prefix);
 
-	DEBUGP(DGGSN, "Setting route to reach %s via %s\n", net_arg, devname);
-
-	if (gtp_dev_config(devname, &net, prefix->prefixlen) < 0) {
-		LOGP(DGGSN, LOGL_ERROR, "Cannot add route to reach network %s\n", net_arg);
-	}
+	return gtp_dev_create(dest_ns, devname, fd0, fd1u);
+}
 
-	/* launch script if it is set to bring up the route to reach
-	 * the MS, eg. ip ro add 10.0.0.0/8 dev gtp0. Better add this
-	 * using native rtnetlink interface given that we know the
-	 * MS network mask, later.
-	 */
-	if (ipup) {
-		char cmd[1024];
-		int err;
-
-		/* eg. /home/ggsn/ipup gtp0 10.0.0.0/8 */
-		snprintf(cmd, sizeof(cmd), "%s %s %s", ipup, devname, net_arg);
-		cmd[sizeof(cmd)-1] = '\0';
-
-		err = system(cmd);
-		if (err < 0) {
-			LOGP(DGGSN, LOGL_ERROR, "Failed to launch script `%s'\n", ipup);
-			return -1;
-		}
-	}
-	LOGP(DGGSN, LOGL_NOTICE, "GTP kernel configured\n");
+int gtp_kernel_create_sgsn(int dest_ns, const char *devname, int fd0, int fd1u)
+{
+	if (gtp_kernel_init_once() < 0)
+		return -1;
 
-	return 0;
+	return gtp_dev_create_sgsn(dest_ns, devname, fd0, fd1u);
 }
 
 void gtp_kernel_stop(const char *devname)
diff --git a/ggsn/gtp-kernel.h b/lib/gtp-kernel.h
index e2da55a..464352c 100644
--- a/ggsn/gtp-kernel.h
+++ b/lib/gtp-kernel.h
@@ -7,18 +7,20 @@ extern int debug;
 extern char *ipup;
 
 #ifdef GTP_KERNEL
-int gtp_kernel_init(struct gsn_t *gsn, const char *devname, struct in46_prefix *prefix, const char *ipup);
+int gtp_kernel_create(int dest_ns, const char *devname, int fd0, int fd1u);
+int gtp_kernel_create_sgsn(int dest_ns, const char *devname, int fd0, int fd1u);
 void gtp_kernel_stop(const char *devname);
 
 int gtp_kernel_tunnel_add(struct pdp_t *pdp, const char *devname);
 int gtp_kernel_tunnel_del(struct pdp_t *pdp, const char *devname);
 
 #else
-static inline int gtp_kernel_init(struct gsn_t *gsn, const char *devname, struct in46_prefix *prefix, const char *ipup)
+static inline int gtp_kernel_create(int dest_ns, const char *devname, int fd0, int fd1u)
 {
 	SYS_ERR(DGGSN, LOGL_ERROR, 0, "ggsn compiled without GTP kernel support!\n");
 	return -1;
 }
+#define gtp_kernel_create_sgsn gtp_kernel_create
 
 static inline void gtp_kernel_stop(const char *devname) {}
 
diff --git a/lib/tun.c b/lib/tun.c
index 6498945..fa4c37d 100644
--- a/lib/tun.c
+++ b/lib/tun.c
@@ -19,6 +19,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -57,6 +58,7 @@
 
 #include "tun.h"
 #include "syserr.h"
+#include "gtp-kernel.h"
 
 static int tun_setaddr4(struct tun_t *this, struct in_addr *addr,
 			struct in_addr *dstaddr, struct in_addr *netmask)
@@ -147,7 +149,7 @@ int tun_addaddr(struct tun_t *this, struct in46_addr *addr, struct in46_addr *ds
 	}
 }
 
-int tun_new(struct tun_t **tun, const char *dev_name)
+int tun_new(struct tun_t **tun, const char *dev_name, bool use_kernel, int fd0, int fd1u)
 {
 
 #if defined(__linux__)
@@ -170,31 +172,50 @@ int tun_new(struct tun_t **tun, const char *dev_name)
 	(*tun)->routes = 0;
 
 #if defined(__linux__)
-	/* Open the actual tun device */
-	if (((*tun)->fd = open("/dev/net/tun", O_RDWR)) < 0) {
-		SYS_ERR(DTUN, LOGL_ERROR, errno, "open() failed");
-		goto err_free;
-	}
-
-	/* Set device flags. For some weird reason this is also the method
-	   used to obtain the network interface name */
-	memset(&ifr, 0, sizeof(ifr));
-	if (dev_name)
-		strcpy(ifr.ifr_name, dev_name);
-	ifr.ifr_flags = IFF_TUN | IFF_NO_PI;	/* Tun device, no packet info */
-	if (ioctl((*tun)->fd, TUNSETIFF, (void *)&ifr) < 0) {
-		SYS_ERR(DTUN, LOGL_ERROR, errno, "ioctl() failed");
-		goto err_close;
+	if (!use_kernel) {
+		/* Open the actual tun device */
+		if (((*tun)->fd = open("/dev/net/tun", O_RDWR)) < 0) {
+			SYS_ERR(DTUN, LOGL_ERROR, errno, "open() failed");
+			goto err_free;
+		}
+
+		/* Set device flags. For some weird reason this is also the method
+		   used to obtain the network interface name */
+		memset(&ifr, 0, sizeof(ifr));
+		if (dev_name)
+			strcpy(ifr.ifr_name, dev_name);
+		ifr.ifr_flags = IFF_TUN | IFF_NO_PI;	/* Tun device, no packet info */
+		if (ioctl((*tun)->fd, TUNSETIFF, (void *)&ifr) < 0) {
+			SYS_ERR(DTUN, LOGL_ERROR, errno, "ioctl() failed");
+			goto err_close;
+		}
+
+		strncpy((*tun)->devname, ifr.ifr_name, IFNAMSIZ);
+		(*tun)->devname[IFNAMSIZ - 1] = 0;
+
+		ioctl((*tun)->fd, TUNSETNOCSUM, 1);	/* Disable checksums */
+		return 0;
+	} else {
+		strncpy((*tun)->devname, dev_name, IFNAMSIZ);
+		(*tun)->devname[IFNAMSIZ - 1] = 0;
+		(*tun)->fd = -1;
+
+		if (gtp_kernel_create(-1, dev_name, fd0, fd1u) < 0) {
+			LOGP(DTUN, LOGL_ERROR, "cannot create GTP tunnel device: %s\n",
+				strerror(errno));
+			return -1;
+		}
+		LOGP(DTUN, LOGL_NOTICE, "GTP kernel configured\n");
+		return 0;
 	}
 
-	strncpy((*tun)->devname, ifr.ifr_name, IFNAMSIZ);
-	(*tun)->devname[IFNAMSIZ - 1] = 0;
-
-	ioctl((*tun)->fd, TUNSETNOCSUM, 1);	/* Disable checksums */
-	return 0;
-
 #elif defined(__FreeBSD__) || defined (__APPLE__)
 
+	if (use_kernel) {
+		LOGP(DTUN, LOGL_ERROR, "No kernel GTP-U support in FreeBSD!\n");
+		return -1;
+	}
+
 	/* Find suitable device */
 	for (devnum = 0; devnum < 255; devnum++) {	/* TODO 255 */
 		snprintf(devname, sizeof(devname), "/dev/tun%d", devnum);
@@ -249,10 +270,14 @@ int tun_free(struct tun_t *tun)
 		netdev_delroute(&tun->dstaddr, &tun->addr, &tun->netmask);
 	}
 
-	if (close(tun->fd)) {
-		SYS_ERR(DTUN, LOGL_ERROR, errno, "close() failed");
+	if (tun->fd >= 0) {
+		if (close(tun->fd)) {
+			SYS_ERR(DTUN, LOGL_ERROR, errno, "close() failed");
+		}
 	}
 
+	gtp_kernel_stop(tun->devname);
+
 	/* TODO: For solaris we need to unlink streams */
 
 	free(tun);
diff --git a/lib/tun.h b/lib/tun.h
index e41ee69..6bf141f 100644
--- a/lib/tun.h
+++ b/lib/tun.h
@@ -13,6 +13,7 @@
 #ifndef _TUN_H
 #define _TUN_H
 
+#include <stdbool.h>
 #include <net/if.h>
 
 #include "../lib/in46_addr.h"
@@ -41,7 +42,7 @@ struct tun_t {
 	void *priv;
 };
 
-extern int tun_new(struct tun_t **tun, const char *dev_name);
+extern int tun_new(struct tun_t **tun, const char *dev_name, bool use_kernel, int fd0, int fd1u);
 extern int tun_free(struct tun_t *tun);
 extern int tun_decaps(struct tun_t *this);
 extern int tun_encaps(struct tun_t *tun, void *pack, unsigned len);
diff --git a/sgsnemu/Makefile.am b/sgsnemu/Makefile.am
index 4d02eca..9f10cd2 100644
--- a/sgsnemu/Makefile.am
+++ b/sgsnemu/Makefile.am
@@ -5,5 +5,11 @@ AM_LDFLAGS = @EXEC_LDFLAGS@
 AM_CFLAGS = -O2 -D_GNU_SOURCE -fno-builtin -Wall -DSBINDIR='"$(sbindir)"' -ggdb $(LIBOSMOCORE_CFLAGS)
 
 sgsnemu_LDADD = @EXEC_LDADD@ -lgtp -L../gtp ../lib/libmisc.a $(LIBOSMOCORE_LIBS)
+
+if ENABLE_GTP_KERNEL
+AM_CFLAGS += -DGTP_KERNEL $(LIBGTPNL_CFLAGS)
+sgsnemu_LDADD += $(LIBGTPNL_LIBS)
+endif
+
 sgsnemu_DEPENDENCIES = ../gtp/libgtp.la ../lib/libmisc.a
 sgsnemu_SOURCES = sgsnemu.c cmdline.c cmdline.h
diff --git a/sgsnemu/sgsnemu.c b/sgsnemu/sgsnemu.c
index 92abc70..1e61a09 100644
--- a/sgsnemu/sgsnemu.c
+++ b/sgsnemu/sgsnemu.c
@@ -1571,7 +1571,7 @@ int main(int argc, char **argv)
 	if (options.createif) {
 		printf("Setting up interface\n");
 		/* Create a tunnel interface */
-		if (tun_new((struct tun_t **)&tun, options.tun_dev_name)) {
+		if (tun_new((struct tun_t **)&tun, options.tun_dev_name, false, -1, -1)) {
 			SYS_ERR(DSGSN, LOGL_ERROR, 0,
 				"Failed to create tun");
 			exit(1);