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/* -*- c++ -*- */
/*
* Copyright 2013 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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 3, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "tuntap_pdu_impl.h"
#include <gnuradio/io_signature.h>
#include <gnuradio/blocks/pdu.h>
#include <boost/format.hpp>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#if (defined(linux) || defined(__linux) || defined(__linux__))
#include <sys/ioctl.h>
#include <arpa/inet.h>
#include <linux/if.h>
#endif
namespace gr {
namespace blocks {
tuntap_pdu::sptr
tuntap_pdu::make(std::string dev, int MTU, bool istunflag)
{
#if (defined(linux) || defined(__linux) || defined(__linux__))
return gnuradio::get_initial_sptr(new tuntap_pdu_impl(dev, MTU, istunflag));
#else
throw std::runtime_error("tuntap_pdu not implemented on this platform");
#endif
}
#if (defined(linux) || defined(__linux) || defined(__linux__))
tuntap_pdu_impl::tuntap_pdu_impl(std::string dev, int MTU, bool istunflag)
: block("tuntap_pdu",
io_signature::make (0, 0, 0),
io_signature::make (0, 0, 0)),
stream_pdu_base(MTU),
d_dev(dev),
d_istunflag(istunflag)
{
// make the tuntap
char dev_cstr[1024];
memset(dev_cstr, 0x00, 1024);
strncpy(dev_cstr, dev.c_str(), std::min(sizeof(dev_cstr), dev.size()));
bool istun = d_istunflag;
if(istun){
d_fd = tun_alloc(dev_cstr, (IFF_TUN | IFF_NO_PI));
} else {
d_fd = tun_alloc(dev_cstr, (IFF_TAP | IFF_NO_PI));
}
if (d_fd <= 0)
throw std::runtime_error("gr::tuntap_pdu::make: tun_alloc failed (are you running as root?)");
int err = set_mtu(dev_cstr, MTU);
if(err < 0)
std::cerr << boost::format(
"gr::tuntap_pdu: failed to set MTU to %d.\n"
"You should use ifconfig to set the MTU. E.g.,\n"
" $ sudo ifconfig %s mtu %d\n"
) % MTU % dev % MTU << std::endl;
std::cout << boost::format(
"Allocated virtual ethernet interface: %s\n"
"You must now use ifconfig to set its IP address. E.g.,\n"
" $ sudo ifconfig %s 192.168.200.1\n"
"Be sure to use a different address in the same subnet for each machine.\n"
) % dev % dev << std::endl;
// set up output message port
message_port_register_out(PDU_PORT_ID);
start_rxthread(this, PDU_PORT_ID);
// set up input message port
message_port_register_in(PDU_PORT_ID);
set_msg_handler(PDU_PORT_ID, boost::bind(&tuntap_pdu_impl::send, this, _1));
}
int
tuntap_pdu_impl::tun_alloc(char *dev, int flags)
{
struct ifreq ifr;
int fd, err;
const char *clonedev = "/dev/net/tun";
/* Arguments taken by the function:
*
* char *dev: the name of an interface (or '\0'). MUST have enough
* space to hold the interface name if '\0' is passed
* int flags: interface flags (eg, IFF_TUN etc.)
*/
/* open the clone device */
if ((fd = open(clonedev, O_RDWR)) < 0)
return fd;
/* preparation of the struct ifr, of type "struct ifreq" */
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = flags; /* IFF_TUN or IFF_TAP, plus maybe IFF_NO_PI */
/* if a device name was specified, put it in the structure; otherwise,
* the kernel will try to allocate the "next" device of the
* specified type
*/
if (*dev)
strncpy(ifr.ifr_name, dev, IFNAMSIZ - 1);
/* try to create the device */
if ((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0) {
close(fd);
return err;
}
/* if the operation was successful, write back the name of the
* interface to the variable "dev", so the caller can know
* it. Note that the caller MUST reserve space in *dev (see calling
* code below)
*/
strcpy(dev, ifr.ifr_name);
/* this is the special file descriptor that the caller will use to talk
* with the virtual interface
*/
return fd;
}
int
tuntap_pdu_impl::set_mtu(const char *dev, int MTU)
{
struct ifreq ifr;
int sfd, err;
/* MTU must be set by passing a socket fd to ioctl;
* create an arbitrary socket for this purpose
*/
if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
return sfd;
/* preparation of the struct ifr, of type "struct ifreq" */
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
ifr.ifr_addr.sa_family = AF_INET; /* address family */
ifr.ifr_mtu = MTU;
/* try to set MTU */
if ((err = ioctl(sfd, SIOCSIFMTU, (void *) &ifr)) < 0)
return err;
return MTU;
}
#endif
} /* namespace blocks */
}/* namespace gr */
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