2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001 Ivo Timmermans <itimmermans@bigfoot.com>,
4 2001 Guus Sliepen <guus@sliepen.warande.net>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 $Id: device.c,v 1.1.2.1 2001/10/12 15:16:03 guus Exp $
25 #include LINUX_IF_TUN_H
27 #include <linux/if_tun.h>
29 #define DEFAULT_DEVICE "/dev/misc/net/tun"
31 #define DEFAULT_DEVICE "/dev/tap0"
34 #define DEVICE_TYPE_ETHERTAP 0
35 #define DEVICE_TYPE_TUNTAP 1
42 int device_total_in = 0;
43 int device_total_out = 0;
46 open the local ethertap device
48 int setup_device(void)
53 if(!get_config_string(lookup_config(config_tree, "Device"), &device_fname)))
54 device_fname = DEFAULT_DEVICE;
57 if((device_fd = open(device_fname, O_RDWR | O_NONBLOCK)) < 0)
59 syslog(LOG_ERR, _("Could not open %s: %m"), device_fname);
63 device_fd = device_fd;
65 /* Set default MAC address for ethertap devices */
67 mymac.type = SUBNET_MAC;
68 mymac.net.mac.address.x[0] = 0xfe;
69 mymac.net.mac.address.x[1] = 0xfd;
70 mymac.net.mac.address.x[2] = 0x00;
71 mymac.net.mac.address.x[3] = 0x00;
72 mymac.net.mac.address.x[4] = 0x00;
73 mymac.net.mac.address.x[5] = 0x00;
76 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
78 memset(&ifr, 0, sizeof(ifr));
80 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
82 strncpy(ifr.ifr_name, netname, IFNAMSIZ);
84 if (!ioctl(device_fd, TUNSETIFF, (void *) &ifr))
86 device_info = _("Linux tun/tap device");
87 device_type = DEVICE_TYPE_TUNTAP;
90 if (!ioctl(device_fd, (('T'<< 8) | 202), (void *) &ifr))
92 syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device_fname);
93 device_type = TAP_TYPE_TUNTAP;
94 device_info = _("Linux tun/tap device");
99 device_info = _("Linux ethertap device");
100 device_type = TAP_TYPE_ETHERTAP;
103 syslog(LOG_INFO, _("%s is a %s"), device_fname, device_info);
109 read, encrypt and send data that is
110 available through the ethertap device
112 int read_packet(vpn_packet_t *packet)
116 if(device_type == DEVICE_TYPE_TUNTAP)
118 if((lenin = read(device_fd, packet->data, MTU)) <= 0)
120 syslog(LOG_ERR, _("Error while reading from %s %s: %m"), device_info, device_fname);
128 struct iovec vector[2] = {{packet->len, 2}, {packet->data, MTU}};
130 if((lenin = readv(device_fd, vector, 2)) <= 0)
132 syslog(LOG_ERR, _("Error while reading from %s %s: %m"), device_info, device_fname);
136 packet->len = lenin - 2;
140 device_total_in += packet->len;
142 if(debug_lvl >= DEBUG_TRAFFIC)
144 syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), device_info, packet.len);
151 int write_packet(vpn_packet_t *packet)
154 if(debug_lvl >= DEBUG_TRAFFIC)
155 syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
156 packet->len, device_info);
158 if(device_type == DEVICE_TYPE_TUNTAP)
160 if(write(device_fd, packet->data, packet->len) < 0)
162 syslog(LOG_ERR, _("Can't write to %s %s: %m"), device_info, packet.len);
168 struct iovec vector[2] = {{packet->len, 2}, {packet->data, MTU}};
170 if(writev(device_fd, vector, 2) < 0)
172 syslog(LOG_ERR, _("Can't write to %s %s: %m"), device_info, packet.len);
177 device_total_out += packet->len;