| 1 | /*************************************************************************** |
| 2 | * Copyright (C) 2006 by Gerd v. Egidy * |
| 3 | * gve@intra2net.com * |
| 4 | * * |
| 5 | * This library is free software; you can redistribute it and/or modify * |
| 6 | * it under the terms of the GNU Lesser General Public License version * |
| 7 | * 2.1 as published by the Free Software Foundation. * |
| 8 | * * |
| 9 | * This library 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 Lesser General Public License for more details. * |
| 13 | * * |
| 14 | * You should have received a copy of the GNU Lesser General Public * |
| 15 | * License along with this program; if not, write to the * |
| 16 | * Free Software Foundation, Inc., * |
| 17 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * |
| 18 | ***************************************************************************/ |
| 19 | |
| 20 | #include <string> |
| 21 | #include <sstream> |
| 22 | #include <iostream> |
| 23 | #include <stdexcept> |
| 24 | |
| 25 | #include <netinet/in.h> |
| 26 | |
| 27 | #include "connection.hxx" |
| 28 | |
| 29 | namespace libt2n |
| 30 | { |
| 31 | |
| 32 | connection::~connection() |
| 33 | { |
| 34 | // Run close() manually since it's a virtual function |
| 35 | // and we are in the destructor. |
| 36 | if (!is_closed()) |
| 37 | { |
| 38 | closed=true; |
| 39 | do_callbacks(connection_closed); |
| 40 | } |
| 41 | |
| 42 | do_callbacks(connection_deleted); |
| 43 | } |
| 44 | |
| 45 | void connection::close() |
| 46 | { |
| 47 | if (!is_closed()) |
| 48 | { |
| 49 | closed=true; |
| 50 | do_callbacks(connection_closed); |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | /// get the number of bytes being available as next complete packet |
| 55 | connection::packet_size_indicator connection::bytes_available() |
| 56 | { |
| 57 | // no size information -> no packet |
| 58 | if (buffer.size() < sizeof(packet_size_indicator)) |
| 59 | return 0; |
| 60 | |
| 61 | packet_size_indicator psize=ntohl(*((packet_size_indicator*)(buffer.data()))); |
| 62 | |
| 63 | // enough data for one packet in buffer? |
| 64 | if (buffer.size() < sizeof(packet_size_indicator)+psize) |
| 65 | return 0; |
| 66 | |
| 67 | // ok, full packet there |
| 68 | return psize; |
| 69 | } |
| 70 | |
| 71 | /** @brief read a complete data packet from the buffer. The packet is removed from the |
| 72 | connection buffer. |
| 73 | @param[out] data the data package |
| 74 | @retval true if packet found |
| 75 | */ |
| 76 | bool connection::get_packet(std::string& data) |
| 77 | { |
| 78 | packet_size_indicator psize; |
| 79 | |
| 80 | if ((psize=bytes_available())) |
| 81 | { |
| 82 | data.assign(buffer,sizeof(packet_size_indicator),psize); |
| 83 | buffer.erase(0,sizeof(packet_size_indicator)+psize); |
| 84 | return true; |
| 85 | } |
| 86 | else |
| 87 | return false; |
| 88 | } |
| 89 | |
| 90 | /** @brief get (maybe incomplete) data of the next packet from the buffer. Does not remove the data |
| 91 | from the connection buffer. |
| 92 | @param[out] data the data package |
| 93 | @retval full size of the packet when it will be complete |
| 94 | */ |
| 95 | unsigned int connection::peek_packet(std::string& data) |
| 96 | { |
| 97 | // no size information -> no packet |
| 98 | if (buffer.size() < sizeof(packet_size_indicator)) |
| 99 | return 0; |
| 100 | |
| 101 | packet_size_indicator psize=ntohl(*((packet_size_indicator*)(buffer.data()))); |
| 102 | |
| 103 | // not the full data available? |
| 104 | packet_size_indicator currsize=psize; |
| 105 | if (buffer.size() < currsize+sizeof(packet_size_indicator)) |
| 106 | currsize=buffer.size()-sizeof(packet_size_indicator); |
| 107 | |
| 108 | data.assign(buffer,sizeof(packet_size_indicator),currsize); |
| 109 | |
| 110 | return psize; |
| 111 | } |
| 112 | |
| 113 | /// remove all data from buffer that is not a complete packet |
| 114 | void connection::remove_incomplete_packets() |
| 115 | { |
| 116 | std::string::size_type p=0; |
| 117 | std::string::size_type end=buffer.size(); |
| 118 | |
| 119 | while (p < end) |
| 120 | { |
| 121 | // not enough space for size information -> no packet |
| 122 | if (p+sizeof(packet_size_indicator) > end) |
| 123 | break; |
| 124 | |
| 125 | packet_size_indicator psize=ntohl(*((packet_size_indicator*)(buffer.data()+p))); |
| 126 | |
| 127 | if (p+sizeof(packet_size_indicator)+psize > end) |
| 128 | { |
| 129 | // incomplete packet |
| 130 | break; |
| 131 | } |
| 132 | else |
| 133 | { |
| 134 | // move p to where the next packet will start |
| 135 | p+=sizeof(packet_size_indicator)+psize; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | if (p < end) |
| 140 | { |
| 141 | // incomplete packets there, remove them |
| 142 | buffer.erase(p); |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | /// send a blob to the peer |
| 147 | void connection::write(const std::string& data) |
| 148 | { |
| 149 | // prepend packet size to data |
| 150 | packet_size_indicator psize=htonl(data.size()); |
| 151 | std::string send_data(data); |
| 152 | send_data.insert(0,(char*)&psize,sizeof(packet_size_indicator)); |
| 153 | |
| 154 | real_write(send_data); |
| 155 | } |
| 156 | |
| 157 | /** @brief add a callback |
| 158 | |
| 159 | @param event event the function will be called at |
| 160 | @param func functor (see boost function) that will be called |
| 161 | |
| 162 | @note use boost::bind to bind to member functions and parameters like this: |
| 163 | 17 is a fixed parameter that is always added to the call |
| 164 | c.add_callback(connection_closed,bind(&my_class::func_to_call_back, boost::ref(*this), 17)); |
| 165 | */ |
| 166 | void connection::add_callback(callback_event_type event, const boost::function<void ()>& func) |
| 167 | { |
| 168 | callbacks[event].push_back(func); |
| 169 | } |
| 170 | |
| 171 | /** @brief an event has occured, execute the callbacks that are registered for this event |
| 172 | |
| 173 | @param event event type that has occured |
| 174 | */ |
| 175 | void connection::do_callbacks(callback_event_type event) |
| 176 | { |
| 177 | std::list<boost::function<void ()> >::iterator i,ie=callbacks[event].end(); |
| 178 | for (i=callbacks[event].begin(); i != ie; i++) |
| 179 | (*i)(); |
| 180 | } |
| 181 | |
| 182 | /** @brief get the callbacks in place for one event |
| 183 | |
| 184 | @param event event the callbacks should be registered for |
| 185 | @return std::list of functors (boost::function) with the callbacks |
| 186 | |
| 187 | @note if you want to get the callbacks for all events, loop from 0 to __events_end |
| 188 | */ |
| 189 | std::list<boost::function<void ()> > connection::get_callback_list(callback_event_type event) |
| 190 | { |
| 191 | return callbacks[event]; |
| 192 | } |
| 193 | |
| 194 | /** @brief reopen a already closed connection, removes incomplete packets from the buffer |
| 195 | |
| 196 | @note Only call when the connection is closed. |
| 197 | |
| 198 | @note Justs cares about the data of connection, reconnecting has to be |
| 199 | done in a derived class. |
| 200 | */ |
| 201 | void connection::reopen() |
| 202 | { |
| 203 | if (!is_closed()) |
| 204 | throw std::logic_error("connection::reopen() called with connection still open"); |
| 205 | |
| 206 | closed=false; |
| 207 | |
| 208 | // incomplete buffer data is worthless with a new connection |
| 209 | remove_incomplete_packets(); |
| 210 | |
| 211 | do_callbacks(new_connection); |
| 212 | } |
| 213 | |
| 214 | } |