/* Copyright (c) 2003, Arvid Norberg All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include "zlib.h" #ifdef _MSC_VER #pragma warning(push, 1) #endif #include #ifdef _MSC_VER #pragma warning(pop) #endif #include "libtorrent/tracker_manager.hpp" #include "libtorrent/http_tracker_connection.hpp" #include "libtorrent/entry.hpp" #include "libtorrent/bencode.hpp" #include "libtorrent/torrent.hpp" #include "libtorrent/io.hpp" using namespace libtorrent; using boost::bind; namespace { enum { minimum_tracker_response_length = 3, http_buffer_size = 2048 }; enum { FTEXT = 0x01, FHCRC = 0x02, FEXTRA = 0x04, FNAME = 0x08, FCOMMENT = 0x10, FRESERVED = 0xe0, GZIP_MAGIC0 = 0x1f, GZIP_MAGIC1 = 0x8b }; } using namespace boost::posix_time; namespace libtorrent { http_parser::http_parser() : m_recv_pos(0) , m_status_code(-1) , m_content_length(-1) , m_content_encoding(plain) , m_state(read_status) , m_recv_buffer(0, 0) , m_body_start_pos(0) , m_finished(false) {} boost::tuple http_parser::incoming(buffer::const_interval recv_buffer) { m_recv_buffer = recv_buffer; boost::tuple ret(0, 0); char const* pos = recv_buffer.begin + m_recv_pos; if (m_state == read_status) { assert(!m_finished); char const* newline = std::find(pos, recv_buffer.end, '\n'); // if we don't have a full line yet, wait. if (newline == recv_buffer.end) return ret; if (newline == pos) throw std::runtime_error("unexpected newline in HTTP response"); std::istringstream line(std::string(pos, newline - 1)); ++newline; int incoming = (int)std::distance(pos, newline); m_recv_pos += incoming; boost::get<1>(ret) += incoming; pos = newline; line >> m_protocol; if (m_protocol.substr(0, 5) != "HTTP/") { throw std::runtime_error("unknown protocol in HTTP response: " + m_protocol); } line >> m_status_code; std::getline(line, m_server_message); m_state = read_header; } if (m_state == read_header) { assert(!m_finished); char const* newline = std::find(pos, recv_buffer.end, '\n'); std::string line; while (newline != recv_buffer.end && m_state == read_header) { if (newline == pos) throw std::runtime_error("unexpected newline in HTTP response"); line.assign(pos, newline - 1); m_recv_pos += newline - pos; boost::get<1>(ret) += newline - pos; pos = newline; std::string::size_type separator = line.find(": "); if (separator == std::string::npos) { ++pos; ++m_recv_pos; boost::get<1>(ret) += 1; m_state = read_body; m_body_start_pos = m_recv_pos; break; } std::string name = line.substr(0, separator); std::string value = line.substr(separator + 2, std::string::npos); m_header.insert(std::make_pair(name, value)); if (name == "Content-Length") { try { m_content_length = boost::lexical_cast(value); } catch(boost::bad_lexical_cast&) {} } else if (name == "Content-Encoding") { if (value == "gzip" || value == "x-gzip") { m_content_encoding = gzip; } else { std::string error_str = "unknown content encoding in response: \""; error_str += value; error_str += "\""; throw std::runtime_error(error_str); } } // TODO: make sure we don't step outside of the buffer ++pos; ++m_recv_pos; assert(m_recv_pos <= (int)recv_buffer.left()); newline = std::find(pos, recv_buffer.end, '\n'); } } if (m_state == read_body) { int incoming = recv_buffer.end - pos; if (m_recv_pos - m_body_start_pos + incoming > m_content_length && m_content_length >= 0) incoming = m_content_length - m_recv_pos + m_body_start_pos; assert(incoming >= 0); m_recv_pos += incoming; boost::get<0>(ret) += incoming; if (m_content_length >= 0 && m_recv_pos - m_body_start_pos >= m_content_length) { m_finished = true; } } return ret; } buffer::const_interval http_parser::get_body() { char const* body_begin = m_recv_buffer.begin + m_body_start_pos; char const* body_end = m_recv_buffer.begin + m_recv_pos; m_recv_pos = 0; m_body_start_pos = 0; m_status_code = -1; m_content_length = -1; m_finished = false; m_state = read_status; m_header.clear(); return buffer::const_interval(body_begin, body_end); } http_tracker_connection::http_tracker_connection( demuxer& d , tracker_manager& man , tracker_request const& req , std::string const& hostname , unsigned short port , std::string request , boost::weak_ptr c , session_settings const& stn , std::string const& auth) : tracker_connection(man, req, d, c) , m_man(man) , m_state(read_status) , m_content_encoding(plain) , m_content_length(0) , m_name_lookup(d) , m_port(port) , m_recv_pos(0) , m_buffer(http_buffer_size) , m_settings(stn) , m_password(auth) , m_code(0) , m_timed_out(false) { const std::string* connect_to_host; bool using_proxy = false; m_send_buffer.assign("GET "); // should we use the proxy? if (!m_settings.proxy_ip.empty()) { connect_to_host = &m_settings.proxy_ip; using_proxy = true; m_send_buffer += "http://"; m_send_buffer += hostname; if (port != 80) { m_send_buffer += ":"; m_send_buffer += boost::lexical_cast(port); } m_port = m_settings.proxy_port != 0 ? m_settings.proxy_port : 80 ; } else { connect_to_host = &hostname; } if (tracker_req().kind == tracker_request::scrape_request) { // find and replace "announce" with "scrape" // in request std::size_t pos = request.find("announce"); if (pos == std::string::npos) throw std::runtime_error("scrape is not available on url: '" + tracker_req().url +"'"); request.replace(pos, 8, "scrape"); } m_send_buffer += request; // if request-string already contains // some parameters, append an ampersand instead // of a question mark if (request.find('?') != std::string::npos) m_send_buffer += "&"; else m_send_buffer += "?"; m_send_buffer += "info_hash="; m_send_buffer += escape_string( reinterpret_cast(req.info_hash.begin()), 20); if (tracker_req().kind == tracker_request::announce_request) { m_send_buffer += "&peer_id="; m_send_buffer += escape_string( reinterpret_cast(req.pid.begin()), 20); m_send_buffer += "&port="; m_send_buffer += boost::lexical_cast(req.listen_port); m_send_buffer += "&uploaded="; m_send_buffer += boost::lexical_cast(req.uploaded); m_send_buffer += "&downloaded="; m_send_buffer += boost::lexical_cast(req.downloaded); m_send_buffer += "&left="; m_send_buffer += boost::lexical_cast(req.left); if (req.web_downloaded > 0) { m_send_buffer += "&http_downloaded="; m_send_buffer += boost::lexical_cast(req.web_downloaded); } if (req.event != tracker_request::none) { const char* event_string[] = {"completed", "started", "stopped"}; m_send_buffer += "&event="; m_send_buffer += event_string[req.event - 1]; } m_send_buffer += "&key="; std::stringstream key_string; key_string << std::hex << req.key; m_send_buffer += key_string.str(); m_send_buffer += "&compact=1"; m_send_buffer += "&numwant="; m_send_buffer += boost::lexical_cast( std::min(req.num_want, 999)); // extension that tells the tracker that // we don't need any peer_id's in the response m_send_buffer += "&no_peer_id=1"; } m_send_buffer += " HTTP/1.0\r\nAccept-Encoding: gzip\r\n" "User-Agent: "; m_send_buffer += m_settings.user_agent; m_send_buffer += "\r\n" "Host: "; m_send_buffer += hostname; if (port != 80) { m_send_buffer += ':'; m_send_buffer += boost::lexical_cast(port); } if (using_proxy && !m_settings.proxy_login.empty()) { m_send_buffer += "\r\nProxy-Authorization: Basic "; m_send_buffer += base64encode(m_settings.proxy_login + ":" + m_settings.proxy_password); } if (auth != "") { m_send_buffer += "\r\nAuthorization: Basic "; m_send_buffer += base64encode(auth); } m_send_buffer += "\r\n\r\n"; #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) { requester().debug_log("==> TRACKER_REQUEST [ str: " + m_send_buffer + " ]"); std::stringstream info_hash_str; info_hash_str << req.info_hash; requester().debug_log("info_hash: " + boost::lexical_cast(req.info_hash)); requester().debug_log("name lookup: " + *connect_to_host); } #endif tcp::resolver::query q(*connect_to_host , boost::lexical_cast(m_port)); m_name_lookup.async_resolve(q , boost::bind(&http_tracker_connection::name_lookup, self(), _1, _2)); set_timeout(m_settings.tracker_completion_timeout , m_settings.tracker_receive_timeout); } void http_tracker_connection::on_timeout() { m_timed_out = true; m_socket.reset(); m_name_lookup.cancel(); fail_timeout(); } void http_tracker_connection::name_lookup(asio::error_code const& error , tcp::resolver::iterator i) try { #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("tracker name lookup handler called"); #endif if (error == asio::error::operation_aborted) return; if (m_timed_out) return; if (error || i == tcp::resolver::iterator()) { fail(-1, error.message().c_str()); return; } #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("tracker name lookup successful"); #endif restart_read_timeout(); m_socket.reset(new stream_socket(m_name_lookup.io_service())); if (has_requester()) requester().m_tracker_address = *i; m_socket->async_connect(*i, bind(&http_tracker_connection::connected, self(), _1)); } catch (std::exception& e) { assert(false); fail(-1, e.what()); }; void http_tracker_connection::connected(asio::error_code const& error) try { if (error == asio::error::operation_aborted) return; if (m_timed_out) return; if (error) { fail(-1, error.message().c_str()); return; } #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("tracker connection successful"); #endif restart_read_timeout(); async_write(*m_socket, asio::buffer(m_send_buffer.c_str() , m_send_buffer.size()), bind(&http_tracker_connection::sent , self(), _1)); } catch (std::exception& e) { assert(false); fail(-1, e.what()); } void http_tracker_connection::sent(asio::error_code const& error) try { if (error == asio::error::operation_aborted) return; if (m_timed_out) return; if (error) { fail(-1, error.message().c_str()); return; } #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("tracker send data completed"); #endif restart_read_timeout(); assert(m_buffer.size() - m_recv_pos > 0); m_socket->async_read_some(asio::buffer(&m_buffer[m_recv_pos] , m_buffer.size() - m_recv_pos), bind(&http_tracker_connection::receive , self(), _1, _2)); } catch (std::exception& e) { assert(false); fail(-1, e.what()); }; // msvc 7.1 seems to require this semi-colon void http_tracker_connection::receive(asio::error_code const& error , std::size_t bytes_transferred) try { if (error == asio::error::operation_aborted) return; if (m_timed_out) return; if (error) { if (error == asio::error::eof) { on_response(); close(); return; } fail(-1, error.message().c_str()); return; } restart_read_timeout(); assert(bytes_transferred > 0); #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("tracker connection reading " + boost::lexical_cast(bytes_transferred)); #endif m_recv_pos += bytes_transferred; // if the receive buffer is full, expand it with http_buffer_size if ((int)m_buffer.size() == m_recv_pos) { if ((int)m_buffer.size() >= m_settings.tracker_maximum_response_length) { fail(200, "too large tracker response"); return; } assert(http_buffer_size > 0); if ((int)m_buffer.size() + http_buffer_size > m_settings.tracker_maximum_response_length) m_buffer.resize(m_settings.tracker_maximum_response_length); else m_buffer.resize(m_buffer.size() + http_buffer_size); } if (m_state == read_status) { std::vector::iterator end = m_buffer.begin()+m_recv_pos; std::vector::iterator newline = std::find(m_buffer.begin(), end, '\n'); // if we don't have a full line yet, wait. if (newline != end) { #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log(std::string(m_buffer.begin(), newline)); #endif std::istringstream line(std::string(m_buffer.begin(), newline)); ++newline; m_recv_pos -= (int)std::distance(m_buffer.begin(), newline); m_buffer.erase(m_buffer.begin(), newline); std::string protocol; line >> m_server_protocol; if (m_server_protocol.substr(0, 5) != "HTTP/") { std::string error_msg = "unknown protocol in response: " + m_server_protocol; fail(-1, error_msg.c_str()); return; } line >> m_code; std::getline(line, m_server_message); m_state = read_header; } } if (m_state == read_header) { std::vector::iterator end = m_buffer.begin() + m_recv_pos; std::vector::iterator newline = std::find(m_buffer.begin(), end, '\n'); std::string line; while (newline != end && m_state == read_header) { line.assign(m_buffer.begin(), newline); #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log(line); #endif if (line.substr(0, 16) == "Content-Length: ") { try { m_content_length = boost::lexical_cast( line.substr(16, line.length() - 17)); } catch(boost::bad_lexical_cast&) { fail(-1, "invalid content-length in tracker response"); return; } if (m_content_length > m_settings.tracker_maximum_response_length) { fail(-1, "content-length is greater than maximum response length"); return; } if (m_content_length < minimum_tracker_response_length && m_code == 200) { fail(-1, "content-length is smaller than minimum response length"); return; } } else if (line.substr(0, 18) == "Content-Encoding: ") { if (line.substr(18, 4) == "gzip" || line.substr(18, 6) == "x-gzip") { m_content_encoding = gzip; } else { std::string error_str = "unknown content encoding in response: \""; error_str += line.substr(18, line.length() - 18 - 2); error_str += "\""; fail(-1, error_str.c_str()); return; } } else if (line.substr(0, 10) == "Location: ") { m_location.assign(line.begin() + 10, line.end()); } else if (line.substr(0, 7) == "Server: ") { m_server.assign(line.begin() + 7, line.end()); } else if (line.size() < 3) { m_state = read_body; #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("end of http header"); #endif if (m_code >= 300 && m_code < 400) { if (m_location.empty()) { std::string error_str = "got redirection response ("; error_str += boost::lexical_cast(m_code); error_str += ") without 'Location' header"; fail(-1, error_str.c_str()); return; } #if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING) if (has_requester()) requester().debug_log("Redirecting to \"" + m_location + "\""); #endif tracker_request req = tracker_req(); std::string::size_type i = m_location.find('?'); if (i == std::string::npos) req.url = m_location; else req.url.assign(m_location.begin(), m_location.begin() + i); m_man.queue_request(m_socket->io_service(), req , m_password, m_requester); close(); return; } } ++newline; assert(m_recv_pos <= (int)m_buffer.size()); m_recv_pos -= (int)std::distance(m_buffer.begin(), newline); m_buffer.erase(m_buffer.begin(), newline); assert(m_recv_pos <= (int)m_buffer.size()); end = m_buffer.begin() + m_recv_pos; newline = std::find(m_buffer.begin(), end, '\n'); } } if (m_state == read_body) { if (m_recv_pos == m_content_length) { on_response(); close(); return; } } else if (m_recv_pos > m_content_length && m_content_length > 0) { fail(-1, "invalid tracker response (body > content_length)"); return; } assert(m_buffer.size() - m_recv_pos > 0); m_socket->async_read_some(asio::buffer(&m_buffer[m_recv_pos] , m_buffer.size() - m_recv_pos), bind(&http_tracker_connection::receive , self(), _1, _2)); } catch (std::exception& e) { assert(false); fail(-1, e.what()); }; void http_tracker_connection::on_response() { // GZIP if (m_content_encoding == gzip) { boost::shared_ptr r = m_requester.lock(); if (!r) { close(); return; } if (inflate_gzip(m_buffer, tracker_request(), r.get(), m_settings.tracker_maximum_response_length)) { close(); return; } } // handle tracker response try { entry e = bdecode(m_buffer.begin(), m_buffer.end()); parse(e); } catch (std::exception& e) { std::string error_str(e.what()); error_str += ": "; error_str.append(m_buffer.begin(), m_buffer.end()); fail(m_code, error_str.c_str()); } #ifndef NDEBUG catch (...) { assert(false); } #endif } peer_entry http_tracker_connection::extract_peer_info(const entry& info) { peer_entry ret; // extract peer id (if any) entry const* i = info.find_key("peer id"); if (i != 0) { if (i->string().length() != 20) throw std::runtime_error("invalid response from tracker"); std::copy(i->string().begin(), i->string().end(), ret.pid.begin()); } else { // if there's no peer_id, just initialize it to a bunch of zeroes std::fill_n(ret.pid.begin(), 20, 0); } // extract ip i = info.find_key("ip"); if (i == 0) throw std::runtime_error("invalid response from tracker"); ret.ip = i->string(); // extract port i = info.find_key("port"); if (i == 0) throw std::runtime_error("invalid response from tracker"); ret.port = (unsigned short)i->integer(); return ret; } void http_tracker_connection::parse(entry const& e) { if (!has_requester()) return; try { // parse the response try { entry const& failure = e["failure reason"]; fail(m_code, failure.string().c_str()); return; } catch (type_error const&) {} try { entry const& warning = e["warning message"]; if (has_requester()) requester().tracker_warning(warning.string()); } catch(type_error const&) {} std::vector peer_list; if (tracker_req().kind == tracker_request::scrape_request) { std::string ih; std::copy(tracker_req().info_hash.begin(), tracker_req().info_hash.end() , std::back_inserter(ih)); entry scrape_data = e["files"][ih]; int complete = scrape_data["complete"].integer(); int incomplete = scrape_data["incomplete"].integer(); requester().tracker_response(tracker_request(), peer_list, 0, complete , incomplete); return; } int interval = (int)e["interval"].integer(); if (e["peers"].type() == entry::string_t) { std::string const& peers = e["peers"].string(); for (std::string::const_iterator i = peers.begin(); i != peers.end();) { if (std::distance(i, peers.end()) < 6) break; peer_entry p; p.pid.clear(); std::stringstream ip_str; ip_str << (int)detail::read_uint8(i) << "."; ip_str << (int)detail::read_uint8(i) << "."; ip_str << (int)detail::read_uint8(i) << "."; ip_str << (int)detail::read_uint8(i); p.ip = ip_str.str(); p.port = detail::read_uint16(i); peer_list.push_back(p); } } else { entry::list_type const& l = e["peers"].list(); for(entry::list_type::const_iterator i = l.begin(); i != l.end(); ++i) { peer_entry p = extract_peer_info(*i); peer_list.push_back(p); } } // look for optional scrape info int complete = -1; int incomplete = -1; try { complete = e["complete"].integer(); } catch(type_error&) {} try { incomplete = e["incomplete"].integer(); } catch(type_error&) {} requester().tracker_response(tracker_request(), peer_list, interval, complete , incomplete); } catch(type_error& e) { requester().tracker_request_error(tracker_request(), m_code, e.what()); } catch(std::runtime_error& e) { requester().tracker_request_error(tracker_request(), m_code, e.what()); } } }