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