diff options
Diffstat (limited to 'gr-blocks/lib/tuntap_pdu_impl.cc')
| -rw-r--r-- | gr-blocks/lib/tuntap_pdu_impl.cc | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/gr-blocks/lib/tuntap_pdu_impl.cc b/gr-blocks/lib/tuntap_pdu_impl.cc new file mode 100644 index 0000000000..1970a92b69 --- /dev/null +++ b/gr-blocks/lib/tuntap_pdu_impl.cc @@ -0,0 +1,139 @@ +/* -*- 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 <gr_io_signature.h> +#include <gr_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) + { +#if (defined(linux) || defined(__linux) || defined(__linux__)) + return gnuradio::get_initial_sptr(new tuntap_pdu_impl(dev, MTU)); +#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) + : gr_block("tuntap_pdu", + gr_make_io_signature (0, 0, 0), + gr_make_io_signature (0, 0, 0)), + stream_pdu_base(MTU), + d_dev(dev) + { + // 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())); + + d_fd = tun_alloc(dev_cstr); + if (d_fd <= 0) + throw std::runtime_error("gr::tuntap_pdu::make: tun_alloc failed (are you running as root?)"); + + 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); + + /* 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; + } +#endif + + } /* namespace blocks */ +}/* namespace gr */ |