// ************************************************************************** /** @namespace Dim @brief Namespace to host some global Dim helper functions */ // ************************************************************************** #include "Dim.h" /* #include #include #include #include */ #include #include using namespace std; // -------------------------------------------------------------------------- // //! Tries to determine the local IP address with which we will connect //! to the DIM dns. //! //! The local IP address is necessary because in some circumstances //! Dim needs the IP address of the connecting machine (DIM_HOST_NODE) //! for the clients to correctly connect to them. So what we would //! need is the IP address over which the machine is reachable from //! the client. Unfortunately, we have no access to the client //! connection, hence, we have to find the best guess of an address //! which is not our own machine and hope it is routed over the //! standard ethernet interface over which other clients will connect. //! //! To not send random packages over the network we use a local //! IP address. To make sure it is something which leaves the network //! card and is not just our machine, we can use a broadcast address. //! Consequently, the deafult has been chosen to be "192.168.0.255" //! //! @param dns //! Address of the Dim-dns //! //! @returns //! The IP Address through which the connection to the DNS will //! take place. //! //! @todo //! Implement a --host command line option (just in case) //! string Dim::GetLocalIp(const string &dns) { using namespace boost::asio; using namespace boost::asio::ip; cout << "Trying to resolve local IP address..." << endl; boost::system::error_code ec; boost::asio::io_service io_service; udp::socket socket(io_service); udp::resolver resolver(io_service); udp::resolver::query query(dns, "0"); udp::resolver::iterator iterator = resolver.resolve(query, ec); if (ec) { //cout << "WARNING - Failure in name-resolution of '" << dns << ":0': "; cout << "WARNING - Could not resolve local ip address: "; cout << ec.message() << " (" << ec << ")" << endl; return dns; } for (; iterator != udp::resolver::iterator(); ++iterator) { udp::endpoint endpoint = *iterator; socket.connect(endpoint, ec); if (ec) { cout << "WARNING - Could not resolve local ip address: "; cout << ec.message() << " (" << ec << ")" << endl; continue; } const string addr = socket.local_endpoint().address().to_v4().to_string(); return addr; } return "localhost"; /* struct addrinfo hints, *servinfo, *p; memset(&hints, 0, sizeof hints); hints.ai_family = AF_INET; //AF_UNSPEC; // use AF_INET6 to force IPv6 hints.ai_socktype = SOCK_STREAM; int rv; if ((rv = getaddrinfo(dns.c_str(), NULL, &hints, &servinfo)) != 0) { cout << "WARNING - getaddrinfo: " << gai_strerror(rv) << endl; return dns; } // loop through all the results and connect to the first we can for (p=servinfo; p; p=p->ai_next) { const int sock = socket(AF_INET, SOCK_DGRAM, 0); if (sock==-1) continue; if (connect(sock, p->ai_addr, p->ai_addrlen)==-1) { cout << "WARNING - connect: " << strerror(errno) << endl; close(sock); continue; } sockaddr_in name; socklen_t namelen = sizeof(name); if (getsockname(sock, (sockaddr*)&name, &namelen)==-1) { cout << "WARNING - getsockname: " << strerror(errno) << endl; close(sock); continue; } char buffer[16]; if (!inet_ntop(AF_INET, &name.sin_addr, buffer, 16)) { cout << "WARNING - inet_ntop: " << strerror(errno) << endl; close(sock); continue; } close(sock); freeaddrinfo(servinfo); // all done with this structure cout << "DIM_HOST_NODE=" << buffer << endl; return buffer; } freeaddrinfo(servinfo); // all done with this structure return dns; */ } // -------------------------------------------------------------------------- // //! Set the environment variable DIM_DNS_NODE to the given string and //! DIM_HOST_NODE to the IP-address through which this machine connects //! to the dns. //! //! @param dns //! Address of the Dim-dns //! void Dim::Setup(const std::string &dns, const std::string &host, const uint16_t &port) { if (dns.empty()) { setenv("DIM_DNS_NODE", "...", 1); //unsetenv("DIM_DNS_NODE"); //unsetenv("DIM_HOST_NODE"); return; } const string loc = host.empty() ? Dim::GetLocalIp(dns.c_str()) : host; setenv("DIM_DNS_NODE", dns.c_str(), 1); setenv("DIM_HOST_NODE", loc.c_str(), 1); if (port>0) setenv("DIM_DNS_PORT", to_string(port).c_str(), 1); cout << "Setting DIM_DNS_NODE =" << dns; if (port>0) cout << ':' << port; cout << "\nSetting DIM_HOST_NODE=" << loc << endl; } extern "C" { const char *GetLocalIp() { static string rc; rc = Dim::GetLocalIp(); cout << "Setting DIM_HOST_NODE=" << rc << endl; return rc.c_str(); } }