src/bsd/tunDevice.cpp

   1 /*
   2  *  anytun
   3  *
   4  *  The secure anycast tunneling protocol (satp) defines a protocol used
   5  *  for communication between any combination of unicast and anycast
   6  *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
   7  *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
   8  *  ethernet, ip, arp ...). satp directly includes cryptography and
   9  *  message authentication based on the methodes used by SRTP.  It is
  10  *  intended to deliver a generic, scaleable and secure solution for
  11  *  tunneling and relaying of packets of any protocol.
  12  *
  13  *
  14  *  Copyright (C) 2007 anytun.org <satp@wirdorange.org>
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2
  18  *  as published by the Free Software Foundation.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program (see the file COPYING included with this
  27  *  distribution); if not, write to the Free Software Foundation, Inc.,
  28  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  29  */
  30
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <errno.h>
  34 #include <sys/socket.h>
  35 #include <net/if.h>
  36 #include <net/if_tun.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/types.h>
  39 #include <sys/uio.h>
  40 #include <netinet/in_systm.h>
  41 #include <netinet/in.h>
  42 #include <netinet/ip.h>
  43
  44 #include <sstream>
  45
  46 #include "tunDevice.h"
  47 #include "threadUtils.hpp"
  48 #define DEVICE_FILE_MAX 255
  49
  50 #include <iostream>
  51
  52 TunDevice::TunDevice(const char* dev_name, const char* dev_type, const char* ifcfg_lp, const char* ifcfg_rnmp) : conf_(dev_name, dev_type, ifcfg_lp, ifcfg_rnmp)
  53 {
  54   std::string device_file = "/dev/";
  55   bool dynamic = true;
  56   if(dev_name) {
  57     device_file.append(dev_name);
  58     dynamic = false;
  59   }
  60   else if(conf_.type_ == TYPE_TUN) {
  61     device_file.append("tun");
  62     actual_name_ = "tun";
  63   }
  64   else if(conf_.type_ == TYPE_TAP) {
  65     device_file.append("tap");
  66     actual_name_ = "tap";
  67   }
  68   else
  69     throw std::runtime_error("unable to recognize type of device (tun or tap)");
  70
  71   u_int32_t dev_id=0;
  72   if(dynamic) {
  73     for(; dev_id <= DEVICE_FILE_MAX; ++dev_id) {
  74       std::ostringstream ds;
  75       ds << device_file;
  76       ds << dev_id;
  77       fd_ = ::open(ds.str().c_str(), O_RDWR);
  78       if(fd_ >= 0)
  79         break;
  80     }
  81   }
  82   else
  83     fd_ = ::open(device_file.c_str(), O_RDWR);
  84
  85   if(fd_ < 0) {
  86     std::string msg;
  87     if(dynamic)
  88       msg = "can't open device file dynamically: no unused node left";
  89     else {
  90       msg = "can't open device file (";
  91       msg.append(device_file);
  92       msg.append("): ");
  93       msg.append(strerror(errno));
  94     }
  95     throw std::runtime_error(msg);
  96   }
  97
  98   if(dynamic) {
  99     std::stringstream s;
 100     s << actual_name_;
 101     s << dev_id;
 102     actual_name_ = s.str();
 103   }
 104   else
 105     actual_name_ = dev_name;
 106
 107   init_post();
 108
 109   if(ifcfg_lp && ifcfg_rnmp)
 110     do_ifconfig();
 111 }
 112
 113 TunDevice::~TunDevice()
 114 {
 115   if(fd_ > 0)
 116     ::close(fd_);
 117 }
 118
 119 #if defined(__GNUC__) && defined(__OpenBSD__)
 120
 121 void TunDevice::init_post()
 122 {
 123   with_type_ = true;
 124   if(conf_.type_ == TYPE_TAP)
 125     with_type_ = false;
 126
 127   struct tuninfo ti;
 128
 129   if (ioctl(fd_, TUNGIFINFO, &ti) < 0)
 130     throw std::runtime_error("can't enable multicast for interface");
 131
 132   ti.flags |= IFF_MULTICAST;
 133
 134   if (ioctl(fd_, TUNSIFINFO, &ti) < 0)
 135     throw std::runtime_error("can't enable multicast for interface");
 136 }
 137
 138 #elif defined(__GNUC__) && defined(__FreeBSD__)
 139
 140 void TunDevice::init_post()
 141 {
 142   with_type_ = true;
 143   if(conf_.type_ == TYPE_TAP)
 144     with_type_ = false;
 145
 146   int arg = 0;
 147   ioctl(fd_, TUNSLMODE, &arg);
 148   arg = 1;
 149   ioctl(fd_, TUNSIFHEAD, &arg);
 150 }
 151
 152 #elif defined(__GNUC__) && defined(__NetBSD__)
 153
 154 void TunDevice::init_post()
 155 {
 156   with_type_ = false;
 157
 158   int arg = IFF_POINTOPOINT|IFF_MULTICAST;
 159   ioctl(fd_, TUNSIFMODE, &arg);
 160   arg = 0;
 161   ioctl(fd_, TUNSLMODE, &arg);
 162 }
 163
 164 #else
 165  #error Target not supported
 166 #endif
 167
 168 int TunDevice::fix_return(int ret, size_t type_length)
 169 {
 170   if(ret < 0)
 171     return ret;
 172
 173   return (static_cast<size_t>(ret) > type_length ? (ret - type_length) : 0);
 174 }
 175
 176 short TunDevice::read(u_int8_t* buf, u_int32_t len)
 177 {
 178   if(fd_ < 0)
 179     return -1;
 180
 181   if(with_type_) {
 182     struct iovec iov[2];
 183     u_int32_t type;
 184
 185     iov[0].iov_base = &type;
 186     iov[0].iov_len = sizeof(type);
 187     iov[1].iov_base = buf;
 188     iov[1].iov_len = len;
 189     return(fix_return(::readv(fd_, iov, 2), sizeof(type)));
 190   }
 191   else
 192     return(::read(fd_, buf, len));
 193 }
 194
 195 int TunDevice::write(u_int8_t* buf, u_int32_t len)
 196 {
 197   if(fd_ < 0)
 198     return -1;
 199
 200   if(with_type_) {
 201     struct iovec iov[2];
 202     u_int32_t type;
 203     struct ip *hdr = reinterpret_cast<struct ip*>(buf);
 204
 205     type = 0;
 206     if(hdr->ip_v == 4)
 207       type = htonl(AF_INET);
 208     else
 209       type = htonl(AF_INET6);
 210
 211     iov[0].iov_base = &type;
 212     iov[0].iov_len = sizeof(type);
 213     iov[1].iov_base = buf;
 214     iov[1].iov_len = len;
 215     return(fix_return(::writev(fd_, iov, 2), sizeof(type)));
 216   }
 217   else
 218     return(::write(fd_, buf, len));
 219 }
 220
 221 const char* TunDevice::getActualName()
 222 {
 223   return actual_name_.c_str();
 224 }
 225
 226 device_type_t TunDevice::getType()
 227 {
 228   return conf_.type_;
 229 }
 230
 231 const char* TunDevice::getTypeString()
 232 {
 233   if(fd_ < 0)
 234     return NULL;
 235
 236   switch(conf_.type_)
 237   {
 238   case TYPE_UNDEF: return "undef"; break;
 239   case TYPE_TUN: return "tun"; break;
 240   case TYPE_TAP: return "tap"; break;
 241   }
 242   return NULL;
 243 }
 244
 245 void TunDevice::do_ifconfig()
 246 {
 247 //   std::string command("/sbin/ifconfig ");
 248 //   command.append(actual_name_);
 249 //   command.append(" ");
 250 //   command.append(conf_.local_.toString());
 251 //   command.append(" ");
 252
 253 //   if(conf_.type_ == TYPE_TUN)
 254 //     command.append("pointopoint ");
 255 //   else
 256 //     command.append("netmask ");
 257
 258 //   command.append(conf_.remote_netmask_.toString());
 259 //   command.append(" mtu 1400");
 260
 261 //   system(command.c_str());
 262 }