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/*
* Copyright (C) 2006 BATMAN contributors:
* Marek Lindner
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include <unistd.h> /* close() */
#include <fcntl.h> /* open(), O_RDWR */
#include <errno.h>
#include <sys/ioctl.h>
#include <netinet/ip.h> /* iph */
#include <linux/if_tun.h> /* TUNSETPERSIST, ... */
#include <linux/if.h> /* ifr_if, ifr_tun */
#include <sys/socket.h>
#include <stdio.h>
#include "../os.h"
#include "../batman.h"
/* Probe for tun interface availability */
int8_t probe_tun(uint8_t print_to_stderr) {
int32_t fd;
if ( ( fd = open( "/dev/net/tun", O_RDWR ) ) < 0 ) {
if (print_to_stderr)
fprintf( stderr, "Error - could not open '/dev/net/tun' ! Is the tun kernel module loaded ?\n" );
else
debug_output( 0, "Error - could not open '/dev/net/tun' ! Is the tun kernel module loaded ?\n" );
return 0;
}
close( fd );
return 1;
}
int8_t del_dev_tun( int32_t fd ) {
if ( ioctl( fd, TUNSETPERSIST, 0 ) < 0 ) {
debug_output( 0, "Error - can't delete tun device: %s\n", strerror(errno) );
return -1;
}
close( fd );
return 1;
}
int8_t add_dev_tun( struct batman_if *batman_if, uint32_t tun_addr, char *tun_dev, size_t tun_dev_size, int32_t *fd, int32_t *ifi ) {
int32_t tmp_fd, sock_opts;
struct ifreq ifr_tun, ifr_if;
struct sockaddr_in addr;
/* set up tunnel device */
memset( &ifr_tun, 0, sizeof(ifr_tun) );
memset( &ifr_if, 0, sizeof(ifr_if) );
ifr_tun.ifr_flags = IFF_TUN | IFF_NO_PI;
strncpy( ifr_tun.ifr_name, "gate%d", IFNAMSIZ );
if ( ( *fd = open( "/dev/net/tun", O_RDWR ) ) < 0 ) {
debug_output( 0, "Error - can't create tun device (/dev/net/tun): %s\n", strerror(errno) );
return -1;
}
if ( ( ioctl( *fd, TUNSETIFF, (void *)&ifr_tun ) ) < 0 ) {
debug_output( 0, "Error - can't create tun device (TUNSETIFF): %s\n", strerror(errno) );
close(*fd);
return -1;
}
if ( ioctl( *fd, TUNSETPERSIST, 1 ) < 0 ) {
debug_output( 0, "Error - can't create tun device (TUNSETPERSIST): %s\n", strerror(errno) );
close(*fd);
return -1;
}
tmp_fd = socket( AF_INET, SOCK_DGRAM, 0 );
if ( tmp_fd < 0 ) {
debug_output( 0, "Error - can't create tun device (udp socket): %s\n", strerror(errno) );
del_dev_tun( *fd );
return -1;
}
/* set ip of this end point of tunnel */
memset( &addr, 0, sizeof(addr) );
addr.sin_addr.s_addr = tun_addr;
addr.sin_family = AF_INET;
memcpy( &ifr_tun.ifr_addr, &addr, sizeof(struct sockaddr) );
if ( ioctl( tmp_fd, SIOCSIFADDR, &ifr_tun) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCSIFADDR): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
if ( ioctl( tmp_fd, SIOCGIFINDEX, &ifr_tun ) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCGIFINDEX): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
*ifi = ifr_tun.ifr_ifindex;
if ( ioctl( tmp_fd, SIOCGIFFLAGS, &ifr_tun) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCGIFFLAGS): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
ifr_tun.ifr_flags |= IFF_UP;
ifr_tun.ifr_flags |= IFF_RUNNING;
if ( ioctl( tmp_fd, SIOCSIFFLAGS, &ifr_tun) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCSIFFLAGS): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
/* get MTU from real interface */
strncpy( ifr_if.ifr_name, batman_if->dev, IFNAMSIZ - 1 );
if ( ioctl( tmp_fd, SIOCGIFMTU, &ifr_if ) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCGIFMTU): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
/* set MTU of tun interface: real MTU - 29 */
if ( ifr_if.ifr_mtu < 100 ) {
debug_output( 0, "Warning - MTU smaller than 100 -> can't reduce MTU anymore\n" );
} else {
ifr_tun.ifr_mtu = ifr_if.ifr_mtu - 29;
if ( ioctl( tmp_fd, SIOCSIFMTU, &ifr_tun ) < 0 ) {
debug_output( 0, "Error - can't create tun device (SIOCSIFMTU): %s\n", strerror(errno) );
del_dev_tun( *fd );
close( tmp_fd );
return -1;
}
}
/* make tun socket non blocking */
sock_opts = fcntl( *fd, F_GETFL, 0 );
fcntl( *fd, F_SETFL, sock_opts | O_NONBLOCK );
strncpy( tun_dev, ifr_tun.ifr_name, tun_dev_size - 1 );
close( tmp_fd );
return 1;
}
int8_t set_tun_addr( int32_t fd, uint32_t tun_addr, char *tun_dev ) {
struct sockaddr_in addr;
struct ifreq ifr_tun;
memset( &ifr_tun, 0, sizeof(ifr_tun) );
memset( &addr, 0, sizeof(addr) );
addr.sin_addr.s_addr = tun_addr;
addr.sin_family = AF_INET;
memcpy( &ifr_tun.ifr_addr, &addr, sizeof(struct sockaddr) );
strncpy( ifr_tun.ifr_name, tun_dev, IFNAMSIZ - 1 );
if ( ioctl( fd, SIOCSIFADDR, &ifr_tun) < 0 ) {
debug_output( 0, "Error - can't set tun address (SIOCSIFADDR): %s\n", strerror(errno) );
return -1;
}
return 1;
}
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