+/*
+ device.c -- Interaction with Linux ethertap and tun/tap device
+ Copyright (C) 2001-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
+ 2001-2002 Guus Sliepen <guus@sliepen.warande.net>
+
+ 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ $Id: device.c,v 1.2 2002/04/09 15:32:14 zarq Exp $
+*/
+
+#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 <linux/if_tun.h>
+ #endif
+ #define DEFAULT_DEVICE "/dev/misc/net/tun"
+#else
+ #define DEFAULT_DEVICE "/dev/tap0"
+#endif
+
+#include <utils.h>
+#include "conf.h"
+#include "net.h"
+#include "subnet.h"
+
+#include "system.h"
+
+#define DEVICE_TYPE_ETHERTAP 0
+#define DEVICE_TYPE_TUNTAP 1
+
+int device_fd = -1;
+int device_type;
+char *device;
+char *interface;
+char ifrname[IFNAMSIZ];
+char *device_info;
+
+int device_total_in = 0;
+int device_total_out = 0;
+
+extern subnet_t mymac;
+
+/*
+ open the local ethertap device
+*/
+int setup_device(void)
+{
+ struct ifreq ifr;
+
+cp
+ if(!get_config_string(lookup_config(config_tree, "Device"), &device))
+ device = DEFAULT_DEVICE;
+
+ if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
+#ifdef HAVE_TUNTAP
+ interface = netname;
+#else
+ interface = rindex(device, '/')?rindex(device, '/')+1:device;
+#endif
+cp
+ if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0)
+ {
+ syslog(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
+ return -1;
+ }
+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
+ /* 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;
+ 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");
+ strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
+ interface = ifrname;
+ }
+ else
+#endif
+ {
+ device_info = _("Linux ethertap device");
+ device_type = DEVICE_TYPE_ETHERTAP;
+ interface = rindex(device, '/')?rindex(device, '/')+1:device;
+ }
+
+ syslog(LOG_INFO, _("%s is a %s"), device, device_info);
+cp
+ return 0;
+}
+
+void close_device(void)
+{
+cp
+ close(device_fd);
+}
+
+/*
+ read, encrypt and send data that is
+ available through the ethertap device
+*/
+int read_packet(vpn_packet_t *packet)
+{
+ int lenin;
+cp
+ if(device_type == DEVICE_TYPE_TUNTAP)
+ {
+ if((lenin = read(device_fd, packet->data, MTU)) <= 0)
+ {
+ syslog(LOG_ERR, _("Error while reading from %s %s: %s"), device_info, device, strerror(errno));
+ return -1;
+ }
+
+ packet->len = lenin;
+ }
+ else /* ethertap */
+ {
+ if((lenin = read(device_fd, packet->data - 2, MTU + 2)) <= 0)
+ {
+ syslog(LOG_ERR, _("Error while reading from %s %s: %s"), device_info, device, strerror(errno));
+ return -1;
+ }
+
+ packet->len = lenin - 2;
+ }
+
+ device_total_in += packet->len;
+
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ {
+ syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len, device_info);
+ }
+
+ return 0;
+cp
+}
+
+int write_packet(vpn_packet_t *packet)
+{
+cp
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ syslog(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;
+ }
+ }
+
+ device_total_out += packet->len;
+cp
+ return 0;
+}
+
+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
+}