/* Copyright (c) 2007, 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 "libtorrent/socket.hpp" #include "libtorrent/enum_net.hpp" #include "libtorrent/broadcast_socket.hpp" #include "libtorrent/assert.hpp" namespace libtorrent { bool is_local(address const& a) { if (a.is_v6()) return a.to_v6().is_link_local(); address_v4 a4 = a.to_v4(); unsigned long ip = a4.to_ulong(); return ((ip & 0xff000000) == 0x0a000000 || (ip & 0xfff00000) == 0xac100000 || (ip & 0xffff0000) == 0xc0a80000); } bool is_loopback(address const& addr) { if (addr.is_v4()) return addr.to_v4() == address_v4::loopback(); else return addr.to_v6() == address_v6::loopback(); } bool is_multicast(address const& addr) { if (addr.is_v4()) return addr.to_v4().is_multicast(); else return addr.to_v6().is_multicast(); } bool is_any(address const& addr) { if (addr.is_v4()) return addr.to_v4() == address_v4::any(); else return addr.to_v6() == address_v6::any(); } address guess_local_address(asio::io_service& ios) { // make a best guess of the interface we're using and its IP asio::error_code ec; std::vector const& interfaces = enum_net_interfaces(ios, ec); address ret = address_v4::any(); for (std::vector::const_iterator i = interfaces.begin() , end(interfaces.end()); i != end; ++i) { address const& a = i->interface_address; if (is_loopback(a) || is_multicast(a) || is_any(a)) continue; // prefer a v4 address, but return a v6 if // there are no v4 if (a.is_v4()) return a; if (ret != address_v4::any()) ret = a; } return ret; } broadcast_socket::broadcast_socket(asio::io_service& ios , udp::endpoint const& multicast_endpoint , receive_handler_t const& handler , bool loopback) : m_multicast_endpoint(multicast_endpoint) , m_on_receive(handler) { TORRENT_ASSERT(is_multicast(m_multicast_endpoint.address())); using namespace asio::ip::multicast; asio::error_code ec; std::vector interfaces = enum_net_interfaces(ios, ec); for (std::vector::const_iterator i = interfaces.begin() , end(interfaces.end()); i != end; ++i) { // only broadcast to IPv4 addresses that are not local if (!is_local(i->interface_address)) continue; // only multicast on compatible networks if (i->interface_address.is_v4() != multicast_endpoint.address().is_v4()) continue; // ignore any loopback interface if (is_loopback(i->interface_address)) continue; boost::shared_ptr s(new datagram_socket(ios)); if (i->interface_address.is_v4()) { s->open(udp::v4(), ec); if (ec) continue; s->set_option(datagram_socket::reuse_address(true), ec); if (ec) continue; s->bind(udp::endpoint(address_v4::any(), multicast_endpoint.port()), ec); if (ec) continue; s->set_option(join_group(multicast_endpoint.address()), ec); if (ec) continue; s->set_option(outbound_interface(i->interface_address.to_v4()), ec); if (ec) continue; } else { s->open(udp::v6(), ec); if (ec) continue; s->set_option(datagram_socket::reuse_address(true), ec); if (ec) continue; s->bind(udp::endpoint(address_v6::any(), multicast_endpoint.port()), ec); if (ec) continue; s->set_option(join_group(multicast_endpoint.address()), ec); if (ec) continue; // s->set_option(outbound_interface(i->interface_address.to_v6()), ec); // if (ec) continue; } s->set_option(hops(255), ec); if (ec) continue; s->set_option(enable_loopback(loopback), ec); if (ec) continue; m_sockets.push_back(socket_entry(s)); socket_entry& se = m_sockets.back(); s->async_receive_from(asio::buffer(se.buffer, sizeof(se.buffer)) , se.remote, bind(&broadcast_socket::on_receive, this, &se, _1, _2)); #ifndef NDEBUG // std::cerr << "broadcast socket [ if: " << i->to_v4().to_string() // << " group: " << multicast_endpoint.address() << " ]" << std::endl; #endif } } void broadcast_socket::send(char const* buffer, int size, asio::error_code& ec) { for (std::list::iterator i = m_sockets.begin() , end(m_sockets.end()); i != end; ++i) { if (!i->socket) continue; asio::error_code e; i->socket->send_to(asio::buffer(buffer, size), m_multicast_endpoint, 0, e); #ifndef NDEBUG // std::cerr << " sending on " << i->socket->local_endpoint().address().to_string() << std::endl; #endif if (e) { i->socket->close(e); i->socket.reset(); } } } void broadcast_socket::on_receive(socket_entry* s, asio::error_code const& ec , std::size_t bytes_transferred) { if (ec || bytes_transferred == 0 || !m_on_receive) return; m_on_receive(s->remote, s->buffer, bytes_transferred); if (!s->socket) return; s->socket->async_receive_from(asio::buffer(s->buffer, sizeof(s->buffer)) , s->remote, bind(&broadcast_socket::on_receive, this, s, _1, _2)); } void broadcast_socket::close() { m_on_receive.clear(); for (std::list::iterator i = m_sockets.begin() , end(m_sockets.end()); i != end; ++i) { if (!i->socket) continue; i->socket->close(); } } }