src/linux/device.c: Fix segfault when running without `--net'.

[tinc] / src / linux / device.c

diff --git a/src/linux/device.c b/src/linux/device.c
index 0461278..4e9591c 100644 (file)
--- a/src/linux/device.c
+++ b/src/linux/device.c
@@ -1,7 +1,7 @@
 /*
     device.c -- Interaction with Linux ethertap and tun/tap device
-    Copyright (C) 2001-2003 Ivo Timmermans <ivo@o2w.nl>,
-                  2001-2003 Guus Sliepen <guus@sliepen.eu.org>
+    Copyright (C) 2001-2005 Ivo Timmermans,
+                  2001-2009 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -17,17 +17,13 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: device.c,v 1.1.2.21 2003/08/28 21:05:11 guus Exp $
+    $Id$
 */
 
 #include "system.h"
 
-#ifdef HAVE_TUNTAP
-#ifdef LINUX_IF_TUN_H
-#include LINUX_IF_TUN_H
-#else
+#ifdef HAVE_LINUX_IF_TUN_H
 #include <linux/if_tun.h>
-#endif
 #define DEFAULT_DEVICE "/dev/net/tun"
 #else
 #define DEFAULT_DEVICE "/dev/tap0"
@@ -38,6 +34,7 @@
 #include "net.h"
 #include "route.h"
 #include "utils.h"
+#include "xalloc.h"
 
 typedef enum device_type_t {
        DEVICE_TYPE_ETHERTAP,
@@ -46,14 +43,14 @@ typedef enum device_type_t {
 } device_type_t;
 
 int device_fd = -1;
-device_type_t device_type;
-char *device;
-char *iface;
-char ifrname[IFNAMSIZ];
-char *device_info;
+static device_type_t device_type;
+char *device = NULL;
+char *iface = NULL;
+static char ifrname[IFNAMSIZ];
+static char *device_info;
 
-int device_total_in = 0;
-int device_total_out = 0;
+static int device_total_in = 0;
+static int device_total_out = 0;
 
 bool setup_device(void)
 {
@@ -62,13 +59,14 @@ bool setup_device(void)
        cp();
 
        if(!get_config_string(lookup_config(config_tree, "Device"), &device))
-               device = DEFAULT_DEVICE;
+               device = xstrdup(DEFAULT_DEVICE);
 
        if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
-#ifdef HAVE_TUNTAP
-               iface = netname;
+#ifdef HAVE_LINUX_IF_TUN_H
+               if (netname != NULL)
+                       iface = xstrdup(netname);
 #else
-               iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
+               iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
 #endif
        device_fd = open(device, O_RDWR | O_NONBLOCK);
 
@@ -77,7 +75,7 @@ bool setup_device(void)
                return false;
        }
 
-#ifdef HAVE_TUNTAP
+#ifdef HAVE_LINUX_IF_TUN_H
        /* Ok now check if this is an old ethertap or a new tun/tap thingie */
 
        memset(&ifr, 0, sizeof(ifr));
@@ -96,11 +94,13 @@ bool setup_device(void)
 
        if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
                strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
-               iface = ifrname;
+               if(iface) free(iface);
+               iface = xstrdup(ifrname);
        } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
                logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
                strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
-               iface = ifrname;
+               if(iface) free(iface);
+               iface = xstrdup(ifrname);
        } else
 #endif
        {
@@ -108,7 +108,9 @@ bool setup_device(void)
                        overwrite_mac = true;
                device_info = _("Linux ethertap device");
                device_type = DEVICE_TYPE_ETHERTAP;
-               iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
+               if(iface)
+                       free(iface);
+               iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
        }
 
        logger(LOG_INFO, _("%s is a %s"), device, device_info);
@@ -121,6 +123,9 @@ void close_device(void)
        cp();
        
        close(device_fd);
+
+       free(device);
+       free(iface);
 }
 
 bool read_packet(vpn_packet_t *packet)