tinc/src/bsd/device.c

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/*
device.c -- Interaction BSD tun/tap device
Copyright (C) 2001-2005 Ivo Timmermans,
2001-2006 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
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 1398 2004-11-01 15:18:53Z guus $
*/
#include "system.h"
#include "conf.h"
#include "logger.h"
#include "net.h"
#include "route.h"
#include "utils.h"
#define DEFAULT_DEVICE "/dev/tun0"
typedef enum device_type {
DEVICE_TYPE_TUN,
DEVICE_TYPE_TUNIFHEAD,
DEVICE_TYPE_TAP,
} device_type_t;
int device_fd = -1;
char *device;
char *iface;
char *device_info;
static int device_total_in = 0;
static int device_total_out = 0;
#ifdef HAVE_OPENBSD
static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
#else
static device_type_t device_type = DEVICE_TYPE_TUN;
#endif
bool setup_device(void) {
char *type;
cp();
if(!get_config_string(lookup_config(config_tree, "Device"), &device))
device = DEFAULT_DEVICE;
if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0) {
logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
return false;
}
if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
if(!strcasecmp(type, "tun"))
/* use default */;
else if(!strcasecmp(type, "tunnohead"))
device_type = DEVICE_TYPE_TUN;
else if(!strcasecmp(type, "tunifhead"))
device_type = DEVICE_TYPE_TUNIFHEAD;
else if(!strcasecmp(type, "tap"))
device_type = DEVICE_TYPE_TAP;
else {
logger(LOG_ERR, _("Unknown device type %s!"), type);
return false;
}
} else {
if(strstr(device, "tap"))
device_type = DEVICE_TYPE_TAP;
}
switch(device_type) {
default:
device_type = DEVICE_TYPE_TUN;
case DEVICE_TYPE_TUN:
#ifdef TUNSIFHEAD
{
const int zero = 0;
if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
return false;
}
}
#endif
#if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
{
const int mode = IFF_BROADCAST | IFF_MULTICAST;
ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
}
#endif
device_info = _("Generic BSD tun device");
break;
case DEVICE_TYPE_TUNIFHEAD:
#ifdef TUNSIFHEAD
{
const int one = 1;
if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
return false;
}
}
#endif
#if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
{
const int mode = IFF_BROADCAST | IFF_MULTICAST;
ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
}
#endif
device_info = _("Generic BSD tun device");
break;
case DEVICE_TYPE_TAP:
if(routing_mode == RMODE_ROUTER)
overwrite_mac = true;
device_info = _("Generic BSD tap device");
break;
}
logger(LOG_INFO, _("%s is a %s"), device, device_info);
return true;
}
void close_device(void) {
cp();
close(device_fd);
}
bool read_packet(vpn_packet_t *packet) {
int lenin;
cp();
switch(device_type) {
case DEVICE_TYPE_TUN:
if((lenin = read(device_fd, packet->data + 14, MTU - 14)) <= 0) {
logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
switch(packet->data[14] >> 4) {
case 4:
packet->data[12] = 0x08;
packet->data[13] = 0x00;
break;
case 6:
packet->data[12] = 0x86;
packet->data[13] = 0xDD;
break;
default:
ifdebug(TRAFFIC) logger(LOG_ERR,
_ ("Unknown IP version %d while reading packet from %s %s"),
packet->data[14] >> 4, device_info, device);
return false;
}
packet->len = lenin + 14;
break;
case DEVICE_TYPE_TUNIFHEAD: {
u_int32_t type;
struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
if((lenin = readv(device_fd, vector, 2)) <= 0) {
logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
switch (ntohl(type)) {
case AF_INET:
packet->data[12] = 0x08;
packet->data[13] = 0x00;
break;
case AF_INET6:
packet->data[12] = 0x86;
packet->data[13] = 0xDD;
break;
default:
ifdebug(TRAFFIC) logger(LOG_ERR,
_ ("Unknown address family %x while reading packet from %s %s"),
ntohl(type), device_info, device);
return false;
}
packet->len = lenin + 10;
break;
}
case DEVICE_TYPE_TAP:
if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
packet->len = lenin;
break;
default:
return false;
}
device_total_in += packet->len;
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
packet->len, device_info);
return true;
}
bool write_packet(vpn_packet_t *packet)
{
cp();
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
packet->len, device_info);
switch(device_type) {
case DEVICE_TYPE_TUN:
if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
break;
case DEVICE_TYPE_TUNIFHEAD: {
u_int32_t type;
struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
int af;
af = (packet->data[12] << 8) + packet->data[13];
switch (af) {
case 0x0800:
type = htonl(AF_INET);
break;
case 0x86DD:
type = htonl(AF_INET6);
break;
default:
ifdebug(TRAFFIC) logger(LOG_ERR,
_("Unknown address family %x while writing packet to %s %s"),
af, device_info, device);
return false;
}
if(writev(device_fd, vector, 2) < 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, _("Error while writing to %s %s: %s"), device_info,
device, strerror(errno));
return false;
}
break;
default:
return false;
}
device_total_out += packet->len;
return true;
}
void dump_device_stats(void)
{
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);
}