src/resolver.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 methods 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) 2007-2014 Markus Grüneis, Othmar Gsenger, Erwin Nindl,
  15  *                          Christian Pointner <satp@wirdorange.org>
  16  *
  17  *  This file is part of Anytun.
  18  *
  19  *  Anytun is free software: you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation, either version 3 of the License, or
  22  *  any later version.
  23  *
  24  *  Anytun is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with Anytun.  If not, see <http://www.gnu.org/licenses/>.
  31  *
  32  *  In addition, as a special exception, the copyright holders give
  33  *  permission to link the code of portions of this program with the
  34  *  OpenSSL library under certain conditions as described in each
  35  *  individual source file, and distribute linked combinations
  36  *  including the two.
  37  *  You must obey the GNU General Public License in all respects
  38  *  for all of the code used other than OpenSSL.  If you modify
  39  *  file(s) with this exception, you may extend this exception to your
  40  *  version of the file(s), but you are not obligated to do so.  If you
  41  *  do not wish to do so, delete this exception statement from your
  42  *  version.  If you delete this exception statement from all source
  43  *  files in the program, then also delete it here.
  44  */
  45
  46 #include <boost/bind.hpp>
  47 #define BOOST_SYSTEM_ENABLE_DEPRECATED
  48 #include <boost/system/error_code.hpp>
  49
  50 #include "resolver.h"
  51 #include "log.h"
  52
  53 using ::boost::asio::ip::udp;
  54 using ::boost::asio::ip::tcp;
  55
  56 template<class Proto>
  57 void waitAndEnqueue(uint32_t s, const std::string& addr, const std::string& port, boost::function<void(boost::asio::ip::basic_resolver_iterator<Proto>)> const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
  58 {
  59   cLog.msg(Log::PRIO_ERROR) << "the resolver only supports udp and tcp";
  60 }
  61
  62 template<>
  63 void waitAndEnqueue(uint32_t s, const std::string& addr, const std::string& port, boost::function<void(boost::asio::ip::basic_resolver_iterator<udp>)> const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
  64 {
  65   boost::this_thread::sleep(boost::posix_time::milliseconds(s * 1000));
  66   gResolver.resolveUdp(addr, port, onResolve, onError, r);
  67 }
  68
  69 template<>
  70 void waitAndEnqueue(uint32_t s, const std::string& addr, const std::string& port, boost::function<void(boost::asio::ip::basic_resolver_iterator<tcp>)> const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
  71 {
  72   boost::this_thread::sleep(boost::posix_time::milliseconds(s * 1000));
  73   gResolver.resolveTcp(addr, port, onResolve, onError, r);
  74 }
  75
  76
  77 template<class Proto>
  78 ResolveHandler<Proto>::ResolveHandler(const std::string& addr, const std::string& port, boost::function<void(boost::asio::ip::basic_resolver_iterator<Proto>)> const& onResolve, ErrorCallback const& onError, ResolvAddrType r) : addr_(addr), port_(port), onResolve_(onResolve), onError_(onError), resolv_addr_type_(r)
  79 {
  80 }
  81
  82 template<class Proto>
  83 void ResolveHandler<Proto>::operator()(const boost::system::error_code& e, boost::asio::ip::basic_resolver_iterator<Proto> endpointIt)
  84 {
  85   if(boost::system::posix_error::success == e) {
  86     try {
  87       onResolve_(endpointIt);
  88     } catch(const std::runtime_error& e) {
  89       onError_(e);
  90     }
  91   } else {
  92     cLog.msg(Log::PRIO_ERROR) << "Error while resolving '" << addr_ << "' '" << port_ << "', retrying in 10 sec.";
  93     boost::thread(boost::bind(waitAndEnqueue<Proto>, 10, addr_, port_, onResolve_, onError_, resolv_addr_type_));
  94   }
  95 }
  96
  97 Resolver& gResolver = Resolver::instance();
  98
  99 Resolver& Resolver::instance()
 100 {
 101   static Resolver instance;
 102   return instance;
 103 }
 104
 105 Resolver::Resolver() : udp_resolver_(io_service_), tcp_resolver_(io_service_), thread_(NULL)
 106 {
 107 }
 108
 109 Resolver::~Resolver()
 110 {
 111   if(thread_) {
 112     delete thread_;
 113   }
 114 }
 115
 116 void Resolver::init()
 117 {
 118   if(!thread_) {
 119     thread_ = new boost::thread(boost::bind(&Resolver::run, this));
 120   }
 121 }
 122
 123 void Resolver::run()
 124 {
 125   cLog.msg(Log::PRIO_DEBUG) << "Resolver Thread started";
 126
 127   for(;;) {
 128     try {
 129       io_service_.run();
 130       io_service_.reset();
 131       boost::this_thread::sleep(boost::posix_time::milliseconds(250));
 132     } catch(const std::runtime_error& e) {
 133       cLog.msg(Log::PRIO_ERROR) << "resolver caught runtime error, restarting: " << e.what();
 134     } catch(const std::exception& e) {
 135       cLog.msg(Log::PRIO_ERROR) << "resolver caught exception, restarting: " << e.what();
 136     }
 137   }
 138 }
 139
 140
 141 void Resolver::resolveUdp(const std::string& addr, const std::string& port, UdpResolveCallback const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
 142 {
 143   cLog.msg(Log::PRIO_DEBUG) << "trying to resolv UDP: '" << addr << "' '" << port << "'";
 144
 145   boost::shared_ptr<udp::resolver::query> query;
 146   if(addr != "") {
 147     switch(r) {
 148     case IPV4_ONLY:
 149       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v4(), addr, port));
 150       break;
 151     case IPV6_ONLY:
 152       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v6(), addr, port));
 153       break;
 154     default:
 155       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(addr, port));
 156       break;
 157     }
 158   } else {
 159     switch(r) {
 160     case IPV4_ONLY:
 161       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v4(), port));
 162       break;
 163     case IPV6_ONLY:
 164       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v6(), port));
 165       break;
 166     default:
 167       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(port));
 168       break;
 169     }
 170   }
 171   UdpResolveHandler handler(addr, port, onResolve, onError, r);
 172   udp_resolver_.async_resolve(*query, handler);
 173 }
 174
 175 void Resolver::resolveTcp(const std::string& addr, const std::string& port, TcpResolveCallback const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
 176 {
 177   cLog.msg(Log::PRIO_DEBUG) << "trying to resolv TCP: '" << addr << "' '" << port << "'";
 178
 179   boost::shared_ptr<tcp::resolver::query> query;
 180   if(addr != "") {
 181     switch(r) {
 182     case IPV4_ONLY:
 183       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v4(), addr, port));
 184       break;
 185     case IPV6_ONLY:
 186       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v6(), addr, port));
 187       break;
 188     default:
 189       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(addr, port));
 190       break;
 191     }
 192   } else {
 193     switch(r) {
 194     case IPV4_ONLY:
 195       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v4(), port));
 196       break;
 197     case IPV6_ONLY:
 198       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v6(), port));
 199       break;
 200     default:
 201       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(port));
 202       break;
 203     }
 204   }
 205   TcpResolveHandler handler(addr, port, onResolve, onError, r);
 206   tcp_resolver_.async_resolve(*query, handler);
 207 }