src/lib/server_finder.cc

   1 /*
   2     Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <libcxml/cxml.h>
  21 #include "server_finder.h"
  22 #include "exceptions.h"
  23 #include "util.h"
  24 #include "config.h"
  25 #include "cross.h"
  26 #include "ui_signaller.h"
  27
  28 using std::string;
  29 using std::stringstream;
  30 using std::list;
  31 using std::vector;
  32 using boost::shared_ptr;
  33 using boost::scoped_array;
  34
  35 ServerFinder* ServerFinder::_instance = 0;
  36
  37 ServerFinder::ServerFinder ()
  38         : _disabled (false)
  39         , _broadcast_thread (0)
  40         , _listen_thread (0)
  41 {
  42         _broadcast_thread = new boost::thread (boost::bind (&ServerFinder::broadcast_thread, this));
  43         _listen_thread = new boost::thread (boost::bind (&ServerFinder::listen_thread, this));
  44 }
  45
  46 void
  47 ServerFinder::broadcast_thread ()
  48 {
  49         boost::system::error_code error;
  50         boost::asio::io_service io_service;
  51         boost::asio::ip::udp::socket socket (io_service);
  52         socket.open (boost::asio::ip::udp::v4(), error);
  53         if (error) {
  54                 throw NetworkError ("failed to set up broadcast socket");
  55         }
  56
  57         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
  58         socket.set_option (boost::asio::socket_base::broadcast (true));
  59
  60         string const data = DCPOMATIC_HELLO;
  61
  62         while (1) {
  63                 if (Config::instance()->use_any_servers ()) {
  64                         /* Broadcast to look for servers */
  65                         boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), Config::instance()->server_port_base() + 1);
  66                         socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
  67                 }
  68
  69                 /* Query our `definite' servers (if there are any) */
  70                 vector<string> servers = Config::instance()->servers ();
  71                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
  72                         try {
  73                                 boost::asio::ip::udp::resolver resolver (io_service);
  74                                 boost::asio::ip::udp::resolver::query query (*i);
  75                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
  76                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
  77                         } catch (...) {
  78
  79                         }
  80                 }
  81
  82                 dcpomatic_sleep (10);
  83         }
  84 }
  85
  86 void
  87 ServerFinder::listen_thread ()
  88 {
  89         while (1) {
  90                 shared_ptr<Socket> sock (new Socket (10));
  91
  92                 try {
  93                         sock->accept (Config::instance()->server_port_base() + 1);
  94                 } catch (std::exception& e) {
  95                         continue;
  96                 }
  97
  98                 uint32_t length = sock->read_uint32 ();
  99                 scoped_array<char> buffer (new char[length]);
 100                 sock->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 101
 102                 stringstream s (buffer.get());
 103                 shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 104                 xml->read_stream (s);
 105
 106                 boost::mutex::scoped_lock lm (_mutex);
 107
 108                 string const ip = sock->socket().remote_endpoint().address().to_string ();
 109                 list<ServerDescription>::const_iterator i = _servers.begin();
 110                 while (i != _servers.end() && i->host_name() != ip) {
 111                         ++i;
 112                 }
 113
 114                 if (i == _servers.end ()) {
 115                         ServerDescription sd (ip, xml->number_child<int> ("Threads"));
 116                         _servers.push_back (sd);
 117                         ui_signaller->emit (boost::bind (boost::ref (ServerFound), sd));
 118                 }
 119         }
 120 }
 121
 122 void
 123 ServerFinder::connect (boost::function<void (ServerDescription)> fn)
 124 {
 125         if (_disabled) {
 126                 return;
 127         }
 128
 129         boost::mutex::scoped_lock lm (_mutex);
 130
 131         /* Emit the current list of servers */
 132         for (list<ServerDescription>::iterator i = _servers.begin(); i != _servers.end(); ++i) {
 133                 fn (*i);
 134         }
 135
 136         ServerFound.connect (fn);
 137 }
 138
 139 ServerFinder*
 140 ServerFinder::instance ()
 141 {
 142         if (!_instance) {
 143                 _instance = new ServerFinder ();
 144         }
 145
 146         return _instance;
 147 }
 148
 149
 150