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/*
* Copyright (C) 2007 Martin Willi
* Hochschule fuer Technik Rapperswil
* Copyright (C) 2002 Jeff Dike
*
* Based on the "tunctl" utility from Jeff Dike.
*
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <linux/if_tun.h>
#include <debug.h>
#include "iface.h"
typedef struct private_iface_t private_iface_t;
struct private_iface_t {
/** public interface */
iface_t public;
/** device name in guest (eth0) */
char *guestif;
/** device name at host (tap0) */
char *hostif;
/** bridge this interface is attached to */
bridge_t *bridge;
/** mconsole for guest */
mconsole_t *mconsole;
};
/**
* bring an interface up or down
*/
bool iface_control(char *name, bool up)
{
int s;
bool good = FALSE;
struct ifreq ifr;
memset(&ifr, 0, sizeof(struct ifreq));
strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
s = socket(AF_INET, SOCK_DGRAM, 0);
if (!s)
{
return FALSE;
}
if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0)
{
if (up)
{
ifr.ifr_flags |= IFF_UP;
}
else
{
ifr.ifr_flags &= ~IFF_UP;
}
if (ioctl(s, SIOCSIFFLAGS, &ifr) == 0)
{
good = TRUE;
}
}
close(s);
return good;
}
/**
* Implementation of iface_t.get_guestif.
*/
static char* get_guestif(private_iface_t *this)
{
return this->guestif;
}
/**
* Implementation of iface_t.get_hostif.
*/
static char* get_hostif(private_iface_t *this)
{
return this->hostif;
}
/**
* Implementation of iface_t.set_bridge.
*/
static void set_bridge(private_iface_t *this, bridge_t *bridge)
{
this->bridge = bridge;
}
/**
* destroy the tap device
*/
static bool destroy_tap(private_iface_t *this)
{
struct ifreq ifr;
int tap;
if (!iface_control(this->hostif, FALSE))
{
DBG1("bringing iface down failed: %m");
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strncpy(ifr.ifr_name, this->hostif, sizeof(ifr.ifr_name) - 1);
tap = open(TAP_DEVICE, O_RDWR);
if (tap < 0)
{
DBG1("unable to open tap device %s: %m", TAP_DEVICE);
return FALSE;
}
if (ioctl(tap, TUNSETIFF, &ifr) < 0 ||
ioctl(tap, TUNSETPERSIST, 0) < 0)
{
DBG1("removing %s failed: %m", this->hostif);
close(tap);
return FALSE;
}
close(tap);
return TRUE;
}
/**
* create the tap device
*/
static char* create_tap(private_iface_t *this, char *guest)
{
struct ifreq ifr;
int tap;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s-%s", guest, this->guestif);
tap = open(TAP_DEVICE, O_RDWR);
if (tap < 0)
{
DBG1("unable to open tap device %s: %m", TAP_DEVICE);
return NULL;
}
if (ioctl(tap, TUNSETIFF, &ifr) < 0 ||
ioctl(tap, TUNSETPERSIST, 1) < 0 ||
ioctl(tap, TUNSETOWNER, 0))
{
DBG1("creating new tap device failed: %m");
close(tap);
return NULL;
}
close(tap);
return strdup(ifr.ifr_name);
}
/**
* Implementation of iface_t.destroy.
*/
static void destroy(private_iface_t *this)
{
if (this->bridge)
{
this->bridge->disconnect_iface(this->bridge, &this->public);
}
this->mconsole->del_iface(this->mconsole, this->guestif);
destroy_tap(this);
free(this->guestif);
free(this->hostif);
free(this);
}
/**
* create the iface instance
*/
iface_t *iface_create(char *guest, char *guestif, mconsole_t *mconsole)
{
private_iface_t *this = malloc_thing(private_iface_t);
this->public.get_hostif = (char*(*)(iface_t*))get_hostif;
this->public.get_guestif = (char*(*)(iface_t*))get_guestif;
this->public.set_bridge = (void(*)(iface_t*, bridge_t*))set_bridge;
this->public.destroy = (void*)destroy;
this->mconsole = mconsole;
this->guestif = strdup(guestif);
this->hostif = create_tap(this, guest);
this->bridge = NULL;
if (this->hostif == NULL)
{
destroy_tap(this);
free(this->guestif);
free(this);
return NULL;
}
if (!iface_control(this->hostif, TRUE))
{
DBG1("bringing iface '%s' up failed: %m", this->hostif);
}
if (!this->mconsole->add_iface(this->mconsole, this->guestif, this->hostif))
{
DBG1("creating interface '%s' in guest failed", this->guestif);
destroy_tap(this);
free(this->guestif);
free(this->hostif);
free(this);
return NULL;
}
return &this->public;
}
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