src/lib/server_finder.cc

   1 /*
   2     Copyright (C) 2013-2014 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 <libdcp/raw_convert.h>
  22 #include "server_finder.h"
  23 #include "exceptions.h"
  24 #include "util.h"
  25 #include "config.h"
  26 #include "cross.h"
  27 #include "ui_signaller.h"
  28
  29 using std::string;
  30 using std::stringstream;
  31 using std::list;
  32 using std::vector;
  33 using std::cout;
  34 using boost::shared_ptr;
  35 using boost::scoped_array;
  36 using libdcp::raw_convert;
  37
  38 ServerFinder* ServerFinder::_instance = 0;
  39
  40 ServerFinder::ServerFinder ()
  41         : _disabled (false)
  42         , _broadcast_thread (0)
  43         , _listen_thread (0)
  44 {
  45         _broadcast_thread = new boost::thread (boost::bind (&ServerFinder::broadcast_thread, this));
  46         _listen_thread = new boost::thread (boost::bind (&ServerFinder::listen_thread, this));
  47 }
  48
  49 void
  50 ServerFinder::broadcast_thread ()
  51 try
  52 {
  53         boost::system::error_code error;
  54         boost::asio::io_service io_service;
  55         boost::asio::ip::udp::socket socket (io_service);
  56         socket.open (boost::asio::ip::udp::v4(), error);
  57         if (error) {
  58                 throw NetworkError ("failed to set up broadcast socket");
  59         }
  60
  61         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
  62         socket.set_option (boost::asio::socket_base::broadcast (true));
  63
  64         string const data = DCPOMATIC_HELLO;
  65
  66         while (true) {
  67                 if (Config::instance()->use_any_servers ()) {
  68                         /* Broadcast to look for servers */
  69                         try {
  70                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), Config::instance()->server_port_base() + 1);
  71                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
  72                         } catch (...) {
  73
  74                         }
  75                 }
  76
  77                 /* Query our `definite' servers (if there are any) */
  78                 vector<string> servers = Config::instance()->servers ();
  79                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
  80                         if (server_found (*i)) {
  81                                 /* Don't bother asking a server that we already know about */
  82                                 continue;
  83                         }
  84                         try {
  85                                 boost::asio::ip::udp::resolver resolver (io_service);
  86                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (Config::instance()->server_port_base() + 1));
  87                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
  88                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
  89                         } catch (...) {
  90
  91                         }
  92                 }
  93
  94                 dcpomatic_sleep (10);
  95         }
  96 }
  97 catch (...)
  98 {
  99         store_current ();
 100 }
 101
 102 void
 103 ServerFinder::listen_thread ()
 104 try
 105 {
 106         while (true) {
 107                 shared_ptr<Socket> sock (new Socket (60));
 108
 109                 try {
 110                         sock->accept (Config::instance()->server_port_base() + 1);
 111                 } catch (std::exception& e) {
 112                         continue;
 113                 }
 114
 115                 uint32_t length = sock->read_uint32 ();
 116                 scoped_array<char> buffer (new char[length]);
 117                 sock->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 118
 119                 stringstream s (buffer.get());
 120                 shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 121                 xml->read_stream (s);
 122
 123                 string const ip = sock->socket().remote_endpoint().address().to_string ();
 124                 if (!server_found (ip)) {
 125                         ServerDescription sd (ip, xml->number_child<int> ("Threads"));
 126                         _servers.push_back (sd);
 127                         ui_signaller->emit (boost::bind (boost::ref (ServerFound), sd));
 128                 }
 129         }
 130 }
 131 catch (...)
 132 {
 133         store_current ();
 134 }
 135
 136 bool
 137 ServerFinder::server_found (string ip) const
 138 {
 139         boost::mutex::scoped_lock lm (_mutex);
 140         list<ServerDescription>::const_iterator i = _servers.begin();
 141         while (i != _servers.end() && i->host_name() != ip) {
 142                 ++i;
 143         }
 144
 145         return i != _servers.end ();
 146 }
 147
 148 void
 149 ServerFinder::connect (boost::function<void (ServerDescription)> fn)
 150 {
 151         if (_disabled) {
 152                 return;
 153         }
 154
 155         boost::mutex::scoped_lock lm (_mutex);
 156
 157         /* Emit the current list of servers */
 158         for (list<ServerDescription>::iterator i = _servers.begin(); i != _servers.end(); ++i) {
 159                 fn (*i);
 160         }
 161
 162         ServerFound.connect (fn);
 163 }
 164
 165 ServerFinder*
 166 ServerFinder::instance ()
 167 {
 168         if (!_instance) {
 169                 _instance = new ServerFinder ();
 170         }
 171
 172         return _instance;
 173 }
 174
 175
 176