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 #include <boost/system/error_code.hpp>
  48
  49 #include "resolver.h"
  50 #include "log.h"
  51
  52 using ::boost::asio::ip::udp;
  53 using ::boost::asio::ip::tcp;
  54
  55 template<class Proto>
  56 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)
  57 {
  58   cLog.msg(Log::PRIO_ERROR) << "the resolver only supports udp and tcp";
  59 }
  60
  61 template<>
  62 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)
  63 {
  64   boost::this_thread::sleep(boost::posix_time::milliseconds(s * 1000));
  65   gResolver.resolveUdp(addr, port, onResolve, onError, r);
  66 }
  67
  68 template<>
  69 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)
  70 {
  71   boost::this_thread::sleep(boost::posix_time::milliseconds(s * 1000));
  72   gResolver.resolveTcp(addr, port, onResolve, onError, r);
  73 }
  74
  75
  76 template<class Proto>
  77 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)
  78 {
  79 }
  80
  81 template<class Proto>
  82 void ResolveHandler<Proto>::operator()(const boost::system::error_code& e, boost::asio::ip::basic_resolver_iterator<Proto> endpointIt)
  83 {
  84   if(boost::system::posix_error::success == e) {
  85     try {
  86       onResolve_(endpointIt);
  87     } catch(const std::runtime_error& e) {
  88       onError_(e);
  89     }
  90   } else {
  91     cLog.msg(Log::PRIO_ERROR) << "Error while resolving '" << addr_ << "' '" << port_ << "', retrying in 10 sec.";
  92     boost::thread(boost::bind(waitAndEnqueue<Proto>, 10, addr_, port_, onResolve_, onError_, resolv_addr_type_));
  93   }
  94 }
  95
  96 Resolver& gResolver = Resolver::instance();
  97
  98 Resolver& Resolver::instance()
  99 {
 100   static Resolver instance;
 101   return instance;
 102 }
 103
 104 Resolver::Resolver() : udp_resolver_(io_service_), tcp_resolver_(io_service_), thread_(NULL)
 105 {
 106 }
 107
 108 Resolver::~Resolver()
 109 {
 110   if(thread_) {
 111     delete thread_;
 112   }
 113 }
 114
 115 void Resolver::init()
 116 {
 117   if(!thread_) {
 118     thread_ = new boost::thread(boost::bind(&Resolver::run, this));
 119   }
 120 }
 121
 122 void Resolver::run()
 123 {
 124   cLog.msg(Log::PRIO_DEBUG) << "Resolver Thread started";
 125
 126   for(;;) {
 127     try {
 128       io_service_.run();
 129       io_service_.reset();
 130       boost::this_thread::sleep(boost::posix_time::milliseconds(250));
 131     } catch(const std::runtime_error& e) {
 132       cLog.msg(Log::PRIO_ERROR) << "resolver caught runtime error, restarting: " << e.what();
 133     } catch(const std::exception& e) {
 134       cLog.msg(Log::PRIO_ERROR) << "resolver caught exception, restarting: " << e.what();
 135     }
 136   }
 137 }
 138
 139
 140 void Resolver::resolveUdp(const std::string& addr, const std::string& port, UdpResolveCallback const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
 141 {
 142   cLog.msg(Log::PRIO_DEBUG) << "trying to resolv UDP: '" << addr << "' '" << port << "'";
 143
 144   boost::shared_ptr<udp::resolver::query> query;
 145   if(addr != "") {
 146     switch(r) {
 147     case IPV4_ONLY:
 148       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v4(), addr, port));
 149       break;
 150     case IPV6_ONLY:
 151       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v6(), addr, port));
 152       break;
 153     default:
 154       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(addr, port));
 155       break;
 156     }
 157   } else {
 158     switch(r) {
 159     case IPV4_ONLY:
 160       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v4(), port));
 161       break;
 162     case IPV6_ONLY:
 163       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(udp::v6(), port));
 164       break;
 165     default:
 166       query = boost::shared_ptr<udp::resolver::query>(new udp::resolver::query(port));
 167       break;
 168     }
 169   }
 170   UdpResolveHandler handler(addr, port, onResolve, onError, r);
 171   udp_resolver_.async_resolve(*query, handler);
 172 }
 173
 174 void Resolver::resolveTcp(const std::string& addr, const std::string& port, TcpResolveCallback const& onResolve, ErrorCallback const& onError, ResolvAddrType r)
 175 {
 176   cLog.msg(Log::PRIO_DEBUG) << "trying to resolv TCP: '" << addr << "' '" << port << "'";
 177
 178   boost::shared_ptr<tcp::resolver::query> query;
 179   if(addr != "") {
 180     switch(r) {
 181     case IPV4_ONLY:
 182       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v4(), addr, port));
 183       break;
 184     case IPV6_ONLY:
 185       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v6(), addr, port));
 186       break;
 187     default:
 188       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(addr, port));
 189       break;
 190     }
 191   } else {
 192     switch(r) {
 193     case IPV4_ONLY:
 194       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v4(), port));
 195       break;
 196     case IPV6_ONLY:
 197       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(tcp::v6(), port));
 198       break;
 199     default:
 200       query = boost::shared_ptr<tcp::resolver::query>(new tcp::resolver::query(port));
 201       break;
 202     }
 203   }
 204   TcpResolveHandler handler(addr, port, onResolve, onError, r);
 205   tcp_resolver_.async_resolve(*query, handler);
 206 }