src/lsd.cpp

   1 /*
   2
   3 Copyright (c) 2007, Arvid Norberg
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without
   7 modification, are permitted provided that the following conditions
   8 are met:
   9
  10     * Redistributions of source code must retain the above copyright
  11       notice, this list of conditions and the following disclaimer.
  12     * Redistributions in binary form must reproduce the above copyright
  13       notice, this list of conditions and the following disclaimer in
  14       the documentation and/or other materials provided with the distribution.
  15     * Neither the name of the author nor the names of its
  16       contributors may be used to endorse or promote products derived
  17       from this software without specific prior written permission.
  18
  19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  23 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29 POSSIBILITY OF SUCH DAMAGE.
  30
  31 */
  32
  33 #include "libtorrent/pch.hpp"
  34
  35 #include "libtorrent/lsd.hpp"
  36 #include "libtorrent/io.hpp"
  37 #include "libtorrent/http_tracker_connection.hpp"
  38 #include "libtorrent/buffer.hpp"
  39 #include "libtorrent/http_parser.hpp"
  40
  41 #include <boost/bind.hpp>
  42 #include <boost/ref.hpp>
  43 #if BOOST_VERSION < 103500
  44 #include <asio/ip/host_name.hpp>
  45 #include <asio/ip/multicast.hpp>
  46 #else
  47 #include <boost/asio/ip/host_name.hpp>
  48 #include <boost/asio/ip/multicast.hpp>
  49 #endif
  50 #include <boost/thread/mutex.hpp>
  51 #include <cstdlib>
  52 #include <boost/config.hpp>
  53
  54 using boost::bind;
  55 using namespace libtorrent;
  56
  57 namespace libtorrent
  58 {
  59         // defined in broadcast_socket.cpp
  60         address guess_local_address(io_service&);
  61 }
  62
  63 lsd::lsd(io_service& ios, address const& listen_interface
  64         , peer_callback_t const& cb)
  65         : m_callback(cb)
  66         , m_retry_count(1)
  67         , m_socket(ios, udp::endpoint(address_v4::from_string("239.192.152.143"), 6771)
  68                 , bind(&lsd::on_announce, self(), _1, _2, _3))
  69         , m_broadcast_timer(ios)
  70         , m_disabled(false)
  71 {
  72 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
  73         m_log.open("lsd.log", std::ios::in | std::ios::out | std::ios::trunc);
  74 #endif
  75 }
  76
  77 lsd::~lsd() {}
  78
  79 void lsd::announce(sha1_hash const& ih, int listen_port)
  80 {
  81         if (m_disabled) return;
  82
  83         std::stringstream btsearch;
  84         btsearch << "BT-SEARCH * HTTP/1.1\r\n"
  85                 "Host: 239.192.152.143:6771\r\n"
  86                 "Port: " << listen_port << "\r\n"
  87                 "Infohash: " << ih << "\r\n"
  88                 "\r\n\r\n";
  89         std::string const& msg = btsearch.str();
  90
  91         m_retry_count = 1;
  92         error_code ec;
  93         m_socket.send(msg.c_str(), int(msg.size()), ec);
  94         if (ec)
  95         {
  96                 m_disabled = true;
  97                 return;
  98         }
  99
 100 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 101         m_log << time_now_string()
 102                 << " ==> announce: ih: " << ih << " port: " << listen_port << std::endl;
 103 #endif
 104
 105         m_broadcast_timer.expires_from_now(milliseconds(250 * m_retry_count), ec);
 106         m_broadcast_timer.async_wait(bind(&lsd::resend_announce, self(), _1, msg));
 107 }
 108
 109 void lsd::resend_announce(error_code const& e, std::string msg)
 110 {
 111         if (e) return;
 112
 113         error_code ec;
 114         m_socket.send(msg.c_str(), int(msg.size()), ec);
 115
 116         ++m_retry_count;
 117         if (m_retry_count >= 5)
 118                 return;
 119
 120         m_broadcast_timer.expires_from_now(milliseconds(250 * m_retry_count), ec);
 121         m_broadcast_timer.async_wait(bind(&lsd::resend_announce, self(), _1, msg));
 122 }
 123
 124 void lsd::on_announce(udp::endpoint const& from, char* buffer
 125         , std::size_t bytes_transferred)
 126 {
 127         using namespace libtorrent::detail;
 128
 129         http_parser p;
 130
 131         bool error = false;
 132         p.incoming(buffer::const_interval(buffer, buffer + bytes_transferred)
 133                 , error);
 134
 135         if (!p.header_finished() || error)
 136         {
 137 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 138         m_log << time_now_string()
 139                 << " <== announce: incomplete HTTP message\n";
 140 #endif
 141                 return;
 142         }
 143
 144         if (p.method() != "bt-search")
 145         {
 146 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 147         m_log << time_now_string()
 148                 << " <== announce: invalid HTTP method: " << p.method() << std::endl;
 149 #endif
 150                 return;
 151         }
 152
 153         std::string const& port_str = p.header("port");
 154         if (port_str.empty())
 155         {
 156 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 157         m_log << time_now_string()
 158                 << " <== announce: invalid BT-SEARCH, missing port" << std::endl;
 159 #endif
 160                 return;
 161         }
 162
 163         std::string const& ih_str = p.header("infohash");
 164         if (ih_str.empty())
 165         {
 166 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 167         m_log << time_now_string()
 168                 << " <== announce: invalid BT-SEARCH, missing infohash" << std::endl;
 169 #endif
 170                 return;
 171         }
 172
 173         sha1_hash ih(0);
 174         std::istringstream ih_sstr(ih_str);
 175         ih_sstr >> ih;
 176         int port = atoi(port_str.c_str());
 177
 178         if (!ih.is_all_zeros() && port != 0)
 179         {
 180 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 181                 m_log << time_now_string()
 182                         << " *** incoming local announce " << from.address()
 183                         << ":" << port << " ih: " << ih << std::endl;
 184 #endif
 185                 // we got an announce, pass it on through the callback
 186 #ifndef BOOST_NO_EXCEPTIONS
 187                 try {
 188 #endif
 189                         m_callback(tcp::endpoint(from.address(), port), ih);
 190 #ifndef BOOST_NO_EXCEPTIONS
 191                 }
 192                 catch (std::exception&) {}
 193 #endif
 194         }
 195 }
 196
 197 void lsd::close()
 198 {
 199         m_socket.close();
 200         error_code ec;
 201         m_broadcast_timer.cancel(ec);
 202         m_disabled = true;
 203         m_callback.clear();
 204 }
 205