src/linux/device.c: Fix segfault when running without `--net'.
[tinc] / src / linux / device.c
index 0391f6a..4e9591c 100644 (file)
@@ -1,7 +1,7 @@
 /*
     device.c -- Interaction with Linux ethertap and tun/tap device
-    Copyright (C) 2001-2002 Ivo Timmermans <ivo@o2w.nl>,
-                  2001-2002 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
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: device.c,v 1.1.2.11 2002/09/09 21:25:23 guus Exp $
+    $Id$
 */
 
-#include "config.h"
-
-#include <stdio.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <net/if.h>
-#include <unistd.h>
-#include <syslog.h>
-#include <string.h>
-#include <sys/ioctl.h>
-
-#ifdef HAVE_TUNTAP
-#ifdef LINUX_IF_TUN_H
-#include LINUX_IF_TUN_H
-#else
+#include "system.h"
+
+#ifdef HAVE_LINUX_IF_TUN_H
 #include <linux/if_tun.h>
-#endif
-#define DEFAULT_DEVICE "/dev/misc/net/tun"
+#define DEFAULT_DEVICE "/dev/net/tun"
 #else
 #define DEFAULT_DEVICE "/dev/tap0"
 #endif
 
-#include <utils.h>
 #include "conf.h"
+#include "logger.h"
 #include "net.h"
-#include "subnet.h"
+#include "route.h"
+#include "utils.h"
+#include "xalloc.h"
 
-#include "system.h"
-
-#define DEVICE_TYPE_ETHERTAP 0
-#define DEVICE_TYPE_TUNTAP 1
+typedef enum device_type_t {
+       DEVICE_TYPE_ETHERTAP,
+       DEVICE_TYPE_TUN,
+       DEVICE_TYPE_TAP,
+} device_type_t;
 
 int device_fd = -1;
-int device_type;
-char *device;
-char *interface;
-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;
 
-extern subnet_t mymac;
-
-/*
-  open the local ethertap device
-*/
-int setup_device(void)
+bool setup_device(void)
 {
        struct ifreq ifr;
 
-       cp if(!get_config_string(lookup_config(config_tree, "Device"), &device))
-               device = DEFAULT_DEVICE;
+       cp();
+
+       if(!get_config_string(lookup_config(config_tree, "Device"), &device))
+               device = xstrdup(DEFAULT_DEVICE);
 
-       if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
-#ifdef HAVE_TUNTAP
-               interface = netname;
+       if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
+#ifdef HAVE_LINUX_IF_TUN_H
+               if (netname != NULL)
+                       iface = xstrdup(netname);
 #else
-               interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
+               iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
 #endif
-       cp device_fd = open(device, O_RDWR | O_NONBLOCK);
+       device_fd = open(device, O_RDWR | O_NONBLOCK);
 
        if(device_fd < 0) {
-               syslog(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
-               return -1;
+               logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
+               return false;
        }
-       cp
-               /* Set default MAC address for ethertap devices */
-               mymac.type = SUBNET_MAC;
-       mymac.net.mac.address.x[0] = 0xfe;
-       mymac.net.mac.address.x[1] = 0xfd;
-       mymac.net.mac.address.x[2] = 0x00;
-       mymac.net.mac.address.x[3] = 0x00;
-       mymac.net.mac.address.x[4] = 0x00;
-       mymac.net.mac.address.x[5] = 0x00;
-
-#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));
-       cp ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
-       if(interface)
-               strncpy(ifr.ifr_name, interface, IFNAMSIZ);
-       cp if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
-               device_info = _("Linux tun/tap device");
-               device_type = DEVICE_TYPE_TUNTAP;
+       if(routing_mode == RMODE_ROUTER) {
+               ifr.ifr_flags = IFF_TUN;
+               device_type = DEVICE_TYPE_TUN;
+               device_info = _("Linux tun/tap device (tun mode)");
+       } else {
+               ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+               device_type = DEVICE_TYPE_TAP;
+               device_info = _("Linux tun/tap device (tap mode)");
+       }
+
+       if(iface)
+               strncpy(ifr.ifr_name, iface, IFNAMSIZ);
+
+       if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
                strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
-               interface = ifrname;
-       } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
-               syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
-               device_type = DEVICE_TYPE_TUNTAP;
-               device_info = _("Linux tun/tap device");
+               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);
-               interface = ifrname;
+               if(iface) free(iface);
+               iface = xstrdup(ifrname);
        } else
 #endif
        {
+               if(routing_mode == RMODE_ROUTER)
+                       overwrite_mac = true;
                device_info = _("Linux ethertap device");
                device_type = DEVICE_TYPE_ETHERTAP;
-               interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
+               if(iface)
+                       free(iface);
+               iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
        }
 
-       syslog(LOG_INFO, _("%s is a %s"), device, device_info);
-       cp return 0;
+       logger(LOG_INFO, _("%s is a %s"), device, device_info);
+
+       return true;
 }
 
 void close_device(void)
 {
-       cp close(device_fd);
+       cp();
+       
+       close(device_fd);
+
+       free(device);
+       free(iface);
 }
 
-/*
-  read, encrypt and send data that is
-  available through the ethertap device
-*/
-int read_packet(vpn_packet_t * packet)
+bool read_packet(vpn_packet_t *packet)
 {
        int lenin;
-       cp if(device_type == DEVICE_TYPE_TUNTAP) {
-               lenin = read(device_fd, packet->data, MTU);
-
-               if(lenin <= 0) {
-                       syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
-                                  device_info, device, strerror(errno));
-                       return -1;
-               }
-
-               packet->len = lenin;
-       } else {                                        /* ethertap */
-
-               lenin = read(device_fd, packet->data - 2, MTU + 2);
-
-               if(lenin <= 0) {
-                       syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
-                                  device_info, device, strerror(errno));
-                       return -1;
-               }
-
-               packet->len = lenin - 2;
+       
+       cp();
+
+       switch(device_type) {
+               case DEVICE_TYPE_TUN:
+                       lenin = read(device_fd, packet->data + 10, MTU - 10);
+
+                       if(lenin <= 0) {
+                               logger(LOG_ERR, _("Error while reading from %s %s: %s"),
+                                          device_info, device, strerror(errno));
+                               return false;
+                       }
+
+                       packet->len = lenin + 10;
+                       break;
+               case DEVICE_TYPE_TAP:
+                       lenin = read(device_fd, packet->data, MTU);
+
+                       if(lenin <= 0) {
+                               logger(LOG_ERR, _("Error while reading from %s %s: %s"),
+                                          device_info, device, strerror(errno));
+                               return false;
+                       }
+
+                       packet->len = lenin;
+                       break;
+               case DEVICE_TYPE_ETHERTAP:
+                       lenin = read(device_fd, packet->data - 2, MTU + 2);
+
+                       if(lenin <= 0) {
+                               logger(LOG_ERR, _("Error while reading from %s %s: %s"),
+                                          device_info, device, strerror(errno));
+                               return false;
+                       }
+
+                       packet->len = lenin - 2;
+                       break;
        }
 
        device_total_in += packet->len;
 
-       if(debug_lvl >= DEBUG_TRAFFIC) {
-               syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
+       ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
                           device_info);
-       }
 
-       return 0;
-cp}
+       return true;
+}
 
-int write_packet(vpn_packet_t * packet)
+bool write_packet(vpn_packet_t *packet)
 {
-       cp if(debug_lvl >= DEBUG_TRAFFIC)
-               syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
+       cp();
+
+       ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
                           packet->len, device_info);
 
-       if(device_type == DEVICE_TYPE_TUNTAP) {
-               if(write(device_fd, packet->data, packet->len) < 0) {
-                       syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
-                                  strerror(errno));
-                       return -1;
-               }
-       } else {                                        /* ethertap */
-
-               *(short int *) (packet->data - 2) = packet->len;
-               if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
-                       syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
-                                  strerror(errno));
-                       return -1;
-               }
+       switch(device_type) {
+               case DEVICE_TYPE_TUN:
+                       packet->data[10] = packet->data[11] = 0;
+                       if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
+                               logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
+                                          strerror(errno));
+                               return false;
+                       }
+                       break;
+               case DEVICE_TYPE_TAP:
+                       if(write(device_fd, packet->data, packet->len) < 0) {
+                               logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
+                                          strerror(errno));
+                               return false;
+                       }
+                       break;
+               case DEVICE_TYPE_ETHERTAP:
+                       *(short int *)(packet->data - 2) = packet->len;
+
+                       if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
+                               logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
+                                          strerror(errno));
+                               return false;
+                       }
+                       break;
        }
 
        device_total_out += packet->len;
-       cp return 0;
+
+       return true;
 }
 
 void dump_device_stats(void)
 {
-       cp syslog(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
-       syslog(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
-       syslog(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
-cp}
+       cp();
+
+       logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
+       logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
+       logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
+}