ibrcommon/ibrcommon/net/vsocket.cpp

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/*
 * vsocket.cpp
 *
 *  Created on: 14.12.2010
 *      Author: morgenro
 */

#include "ibrcommon/net/vsocket.h"
#include <ibrcommon/thread/MutexLock.h>
#include <ibrcommon/Logger.h>
#include <algorithm>

#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/tcp.h>
#include <sys/un.h>
#include <errno.h>
#include <sstream>
#include <string.h>
#include <fcntl.h>
#include <signal.h>
#include <arpa/inet.h>

namespace ibrcommon
{
        void vsocket::set_non_blocking(int fd, bool nonblock)
        {
                int opts;
                opts = fcntl(fd,F_GETFL);
                if (opts < 0) {
                        throw vsocket_exception("cannot set non-blocking");
                }

                if (nonblock)
                        opts |= O_NONBLOCK;
                else
                        opts &= ~(O_NONBLOCK);

                if (fcntl(fd,F_SETFL,opts) < 0) {
                        throw vsocket_exception("cannot set non-blocking");
                }
        }

        vsocket::vsocket()
         : _options(0), _interrupt(false), _listen_connections(0), _cb(NULL)
        {
                // create a pipe for interruption
                if (pipe(_interrupt_pipe) < 0)
                {
                        printf ("Error %d creating pipe\n", errno);
                        exit (-1);
                }

                // set the pipe to non-blocking
                vsocket::set_non_blocking(_interrupt_pipe[0]);
                vsocket::set_non_blocking(_interrupt_pipe[1]);
        }

        vsocket::~vsocket()
        {
                ibrcommon::LinkManager::getInstance().unregisterAllEvents(this);
        }

        int vsocket::bind(const vsocket::vbind &b)
        {
                _binds.push_back(b);
                vsocket::vbind &vb = _binds.back();

                try {
                        if (_options & VSOCKET_REUSEADDR) vb.set(VSOCKET_REUSEADDR);
                        if (_options & VSOCKET_BROADCAST) vb.set(VSOCKET_BROADCAST);
                        if (_options & VSOCKET_MULTICAST) vb.set(VSOCKET_MULTICAST);
                        if (_options & VSOCKET_MULTICAST_V6) vb.set(VSOCKET_MULTICAST_V6);

                        vb.bind();

                        if (_options & VSOCKET_LINGER) vb.set(VSOCKET_LINGER);
                        if (_options & VSOCKET_NODELAY) vb.set(VSOCKET_NODELAY);
                        if (_options & VSOCKET_NONBLOCKING) vb.set(VSOCKET_NONBLOCKING);

                        return vb._fd;
                } catch (const vsocket_exception&) {
                        _binds.pop_back();
                        throw;
                }
        }

        void vsocket::bind(const vinterface &iface, const int port, unsigned int socktype)
        {
                if (iface.empty()) { bind(port); return; }

                // remember the port for dynamic bind/unbind
                _portmap[iface] = port;
                _typemap[iface] = socktype;

                // watch at events on this interface
                ibrcommon::LinkManager::getInstance().registerInterfaceEvent(iface, this);

                // bind on all interfaces of "iface"!
                const std::list<vaddress> addrlist = iface.getAddresses();

                for (std::list<vaddress>::const_iterator iter = addrlist.begin(); iter != addrlist.end(); iter++)
                {
                        if (!iter->isBroadcast())
                        {
                                if (port == 0)
                                {
                                        vsocket::vbind vb(iface, (*iter), socktype);
                                        bind( vb );
                                }
                                else
                                {
                                        vsocket::vbind vb(iface, (*iter), port, socktype);
                                        bind( vb );
                                }
                        }
                }
        }

        void vsocket::unbind(const vinterface &iface, const int port)
        {
                // delete the watch at events on this interface
                ibrcommon::LinkManager::getInstance().unregisterInterfaceEvent(iface, this);

                // unbind all interfaces on interface "iface"!
                const std::list<vaddress> addrlist = iface.getAddresses();

                for (std::list<vaddress>::const_iterator iter = addrlist.begin(); iter != addrlist.end(); iter++)
                {
                        if (!iter->isBroadcast())
                        {
                                unbind( *iter, port );
                        }
                }
        }

        int vsocket::bind(const int port, unsigned int socktype)
        {
                vaddress addr;
                return bind( addr, port, socktype );
        }

        void vsocket::unbind(const int port)
        {
                vaddress addr;
                unbind( addr, port );
        }

        int vsocket::bind(const vaddress &address, const int port, unsigned int socktype)
        {
                vsocket::vbind vb(address, port, socktype);
                return bind( vb );
        }

        int vsocket::bind(const ibrcommon::File &file, unsigned int socktype)
        {
                vsocket::vbind vb(file, socktype);
                return bind( vb );
        }

        void vsocket::unbind(const vaddress &address, const int port)
        {
                for (std::list<vsocket::vbind>::iterator iter = _binds.begin(); iter != _binds.end(); iter++)
                {
                        vsocket::vbind &b = (*iter);
                        if ((b._vaddress == address) && (b._port == port))
                        {
                                _unbind_queue.push(b);
                        }
                }
        }

        void vsocket::unbind(const ibrcommon::File &file)
        {
                for (std::list<vsocket::vbind>::iterator iter = _binds.begin(); iter != _binds.end(); iter++)
                {
                        vsocket::vbind &b = (*iter);
                        if (b._file == file)
                        {
                                _unbind_queue.push(b);
                        }
                }
        }

        void vsocket::add(const int fd)
        {
                vsocket::vbind vb(fd);
                bind(vb);
        }

        void vsocket::listen(int connections)
        {
                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        bind.listen(connections);
                }

                _listen_connections = connections;
        }

        void vsocket::relisten()
        {
                if (_listen_connections > 0)
                        listen(_listen_connections);
        }

        void vsocket::set(const Option &o)
        {
                // set options
                _options |= o;

                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        bind.set(o);
                }
        }

        void vsocket::unset(const Option &o)
        {
                // unset options
                _options &= ~(o);

                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        bind.unset(o);
                }
        }

        void vsocket::close()
        {
                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        bind.close();
                        _binds.erase(iter++);
                }

                interrupt();
        }

        void vsocket::shutdown()
        {
                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        bind.shutdown();
                }

                interrupt();
        }

        int vsocket::fd()
        {
                if (_binds.empty()) return -1;
                return _binds.front()._fd;
        }

        void vsocket::eventNotify(const LinkManagerEvent &evt)
        {
                const ibrcommon::vinterface &iface = evt.getInterface();
                IBRCOMMON_LOGGER_DEBUG(5) << "update socket cause of event on interface " << iface.toString() << IBRCOMMON_LOGGER_ENDL;

                // check if the portmap for this interface is available
                if (_portmap.find(evt.getInterface()) == _portmap.end()) return;

                try {
                        switch (evt.getType())
                        {
                        case LinkManagerEvent::EVENT_ADDRESS_ADDED:
                        {
                                IBRCOMMON_LOGGER_DEBUG(10) << "dynamic address bind on: " << evt.getAddress().toString() << ":" << _portmap[iface] << IBRCOMMON_LOGGER_ENDL;
                                vsocket::vbind vb(iface, evt.getAddress(), _portmap[iface], _typemap[iface]);
                                bind( vb );
                                break;
                        }

                        case LinkManagerEvent::EVENT_ADDRESS_REMOVED:
                                IBRCOMMON_LOGGER_DEBUG(10) << "dynamic address unbind on: " << evt.getAddress().toString() << ":" << _portmap[iface] << IBRCOMMON_LOGGER_ENDL;
                                unbind(evt.getAddress(), _portmap[iface]);
                                break;

                        default:
                                break;
                        }
                } catch (const ibrcommon::Exception &ex) {
                        IBRCOMMON_LOGGER(warning) << "dynamic bind process failed: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                }

                // forward the event to the listen callback class
                if (_cb != NULL) _cb->eventNotify(evt);

                // refresh the select call
                refresh();
        }

        void vsocket::setEventCallback(ibrcommon::LinkManager::EventCallback *cb)
        {
                _cb = cb;
        }

        const std::list<int> vsocket::get(const ibrcommon::vinterface &iface, const ibrcommon::vaddress::Family f)
        {
                std::list<int> ret;

                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        if (bind._interface == iface)
                        {
                                if ((f == vaddress::VADDRESS_UNSPEC) || (f == bind._vaddress.getFamily())) ret.push_back(bind._fd);
                        }
                }

                return ret;
        }

        const std::list<int> vsocket::get(const ibrcommon::vaddress::Family f)
        {
                std::list<int> ret;

                ibrcommon::MutexLock l(_bind_lock);
                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                iter != _binds.end(); iter++)
                {
                        ibrcommon::vsocket::vbind &bind = (*iter);
                        if ((f == vaddress::VADDRESS_UNSPEC) || (f == bind._vaddress.getFamily())) ret.push_back(bind._fd);
                }

                return ret;
        }

        int vsocket::sendto(const void *buf, size_t n, const ibrcommon::vaddress &address, const unsigned int port)
        {
                try {
                        size_t ret = 0;
                        int flags = 0;

                        struct addrinfo hints, *ainfo;
                        memset(&hints, 0, sizeof hints);

                        hints.ai_socktype = SOCK_DGRAM;
                        ainfo = address.addrinfo(&hints, port);

                        ibrcommon::MutexLock l(_bind_lock);
                        for (std::list<ibrcommon::vsocket::vbind>::iterator iter = _binds.begin();
                                        iter != _binds.end(); iter++)
                        {
                                ibrcommon::vsocket::vbind &bind = (*iter);
                                if (bind._vaddress.getFamily() == address.getFamily())
                                {
                                        std::cout << "send to interface " << bind._interface.toString() << "; " << bind._vaddress.toString() << std::endl;
                                        ret = ::sendto(bind._fd, buf, n, flags, ainfo->ai_addr, ainfo->ai_addrlen);
                                }
                        }

                        freeaddrinfo(ainfo);

                        return ret;
                } catch (const vsocket_exception&) {
                        IBRCOMMON_LOGGER_DEBUG(5) << "can not send message to " << address.toString() << IBRCOMMON_LOGGER_ENDL;
                }

                return -1;
        }

        int recvfrom(int fd, char* data, size_t maxbuffer, std::string &address)
        {
                struct sockaddr_in clientAddress;
                socklen_t clientAddressLength = sizeof(clientAddress);

                // data waiting
                int ret = recvfrom(fd, data, maxbuffer, MSG_WAITALL, (struct sockaddr *) &clientAddress, &clientAddressLength);

                char str[INET_ADDRSTRLEN];
                inet_ntop(AF_INET, &(clientAddress.sin_addr), str, INET_ADDRSTRLEN);

                address = std::string(str);

                return ret;
        }

        void vsocket::refresh()
        {
                ::write(_interrupt_pipe[1], "i", 1);
        }

        void vsocket::interrupt()
        {
                _interrupt = true;
                ::write(_interrupt_pipe[1], "i", 1);
        }

        void vsocket::select(std::list<int> &fds, struct timeval *tv)
        {
                fd_set fds_read;

                int high_fd = 0;
                int fd_count = 0;

                // clear the fds list
                fds.clear();

                while (true)
                {
                        FD_ZERO(&fds_read);

                        // add the self-pipe-trick interrupt fd
                        FD_SET(_interrupt_pipe[0], &fds_read);
                        high_fd = _interrupt_pipe[0];

                        {
                                ibrcommon::MutexLock l(_bind_lock);
                                std::list<ibrcommon::vsocket::vbind> &socks = _binds;
                                for (std::list<ibrcommon::vsocket::vbind>::iterator iter = socks.begin();
                                                iter != socks.end(); iter++)
                                {
                                        ibrcommon::vsocket::vbind &bind = (*iter);

                                        FD_SET(bind._fd, &fds_read);
                                        if (high_fd < bind._fd) high_fd = bind._fd;

                                        fd_count++;
                                }
                        }

                        if (fd_count == 0)
                                throw vsocket_exception("select error");

                        int res = ::select(high_fd + 1, &fds_read, NULL, NULL, tv);

                        if (res < 0)
                                throw vsocket_exception("select error");

                        if (res == 0)
                                throw vsocket_timeout("select timeout");

                        if (FD_ISSET(_interrupt_pipe[0], &fds_read))
                        {
                                IBRCOMMON_LOGGER_DEBUG(25) << "unblocked by self-pipe-trick" << IBRCOMMON_LOGGER_ENDL;

                                // this was an interrupt with the self-pipe-trick
                                char buf[2];
                                ::read(_interrupt_pipe[0], buf, 2);

                                if (!_unbind_queue.empty())
                                {
                                        // unbind all removed sockets now
                                        ibrcommon::Queue<vsocket::vbind>::Locked lq = _unbind_queue.exclusive();

                                        vsocket::vbind &vb = lq.front();

                                        for (std::list<vsocket::vbind>::iterator iter = _binds.begin(); iter != _binds.end(); iter++)
                                        {
                                                vsocket::vbind &i = (*iter);
                                                if (i == vb)
                                                {
                                                        IBRCOMMON_LOGGER_DEBUG(25) << "socket closed" << IBRCOMMON_LOGGER_ENDL;
                                                        i.close();
                                                        _binds.erase(iter);
                                                        break;
                                                }
                                        }

                                        lq.pop();
                                }

                                // listen on all new binds
                                relisten();

                                // interrupt the method if requested
                                if (_interrupt)
                                {
                                        _interrupt = false;
                                        throw vsocket_interrupt("select interrupted");
                                }

                                // start over with the select call
                                continue;
                        }

                        ibrcommon::MutexLock l(_bind_lock);
                        std::list<ibrcommon::vsocket::vbind> &socks = _binds;
                        for (std::list<ibrcommon::vsocket::vbind>::iterator iter = socks.begin();
                                        iter != socks.end(); iter++)
                        {
                                ibrcommon::vsocket::vbind &bind = (*iter);

                                if (FD_ISSET(bind._fd, &fds_read))
                                {
                                        fds.push_back(bind._fd);
                                }
                        }

                        if (fds.size() > 0) return;
                }
        }

        vsocket::vbind::vbind(const int fd)
         : _type(BIND_CUSTOM), _vaddress(), _port(), _fd(fd)
        {
                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::vbind(const vaddress &address, unsigned int socktype)
         : _type(BIND_ADDRESS_NOPORT), _vaddress(address), _port(0), _fd(0)
        {
                _fd = socket(address.getFamily(), socktype, 0);

                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::vbind(const vaddress &address, const int port, unsigned int socktype)
         : _type(BIND_ADDRESS), _vaddress(address), _port(port), _fd(0)
        {
                _fd = socket(address.getFamily(), socktype, 0);

                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::vbind(const ibrcommon::vinterface &iface, const vaddress &address, unsigned int socktype)
         : _type(BIND_ADDRESS_NOPORT), _vaddress(address), _port(0), _interface(iface), _fd(0)
        {
                _fd = socket(address.getFamily(), socktype, 0);

                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::vbind(const ibrcommon::vinterface &iface, const vaddress &address, const int port, unsigned int socktype)
         : _type(BIND_ADDRESS), _vaddress(address), _port(port), _interface(iface), _fd(0)
        {
                _fd = socket(address.getFamily(), socktype, 0);

                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::vbind(const ibrcommon::File &file, unsigned int socktype)
         : _type(BIND_FILE), _port(0), _file(file), _fd(0)
        {
                _fd = socket(AF_UNIX, socktype, 0);

                // check for errors
                if (_fd < 0) try {
                        check_socket_error( _fd );
                } catch (...) {
                        close();
                        throw;
                }
        }

        vsocket::vbind::~vbind()
        {
        }

        void vsocket::vbind::bind()
        {
                int bind_ret = 0;

                switch (_type)
                {
                        case BIND_CUSTOM:
                        {
                                // custom fd, do nothing
                                break;
                        }

                        case BIND_ADDRESS_NOPORT:
                        {
                                struct addrinfo hints, *res;
                                memset(&hints, 0, sizeof hints);

                                hints.ai_family = _vaddress.getFamily();
                                hints.ai_socktype = SOCK_STREAM;
                                hints.ai_flags = AI_PASSIVE;

                                res = _vaddress.addrinfo(&hints);
                                bind_ret = ::bind(_fd, res->ai_addr, res->ai_addrlen);
                                freeaddrinfo(res);
                                break;
                        }

                        case BIND_ADDRESS:
                        {
                                struct addrinfo hints, *res;
                                memset(&hints, 0, sizeof hints);

                                hints.ai_family = _vaddress.getFamily();
                                hints.ai_socktype = SOCK_STREAM;
                                hints.ai_flags = AI_PASSIVE;

                                res = _vaddress.addrinfo(&hints, _port);
                                bind_ret = ::bind(_fd, res->ai_addr, res->ai_addrlen);
                                freeaddrinfo(res);
                                break;
                        }

                        case BIND_FILE:
                        {
                                // remove old sockets
                                unlink(_file.getPath().c_str());

                                struct sockaddr_un address;
                                size_t address_length;

                                address.sun_family = AF_UNIX;
                                strcpy(address.sun_path, _file.getPath().c_str());
                                address_length = sizeof(address.sun_family) + strlen(address.sun_path);

                                // bind to the socket
                                bind_ret = ::bind(_fd, (struct sockaddr *) &address, address_length);

                                break;
                        }
                }

                if ( bind_ret < 0) check_bind_error( bind_ret );
        }

        void vsocket::vbind::listen(int connections)
        {
                if(::listen(_fd, connections) != 0)
                {
                        throw ibrcommon::vsocket_exception("cannot listen to socket");
                }
        }

        void vsocket::vbind::set(const vsocket::Option &o)
        {
                switch (o)
                {
                        case VSOCKET_REUSEADDR:
                        {
                                int on = 1;
                                if (::setsockopt(_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
                                {
                                        throw vsocket_exception("setsockopt(SO_REUSEADDR) failed");
                                }
                                break;
                        }

                        case VSOCKET_LINGER:
                        {
                                int set = 1;
                                ::setsockopt(_fd, IPPROTO_TCP, TCP_NODELAY, (char *)&set, sizeof(set));
                                break;
                        }

                        case VSOCKET_NODELAY:
                        {
                                // set linger option to the socket
                                struct linger linger;

                                linger.l_onoff = 1;
                                linger.l_linger = 1;
                                ::setsockopt(_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
                                break;
                        }

                        case VSOCKET_BROADCAST:
                        {
                                int b = 1;
                                if ( ::setsockopt(_fd, SOL_SOCKET, SO_BROADCAST, (char*)&b, sizeof(b)) == -1 )
                                {
                                        throw vsocket_exception("cannot enable broadcasts");
                                }
                                break;
                        }

                        case VSOCKET_NONBLOCKING:
                        {
                                vsocket::set_non_blocking(_fd);
                                break;
                        }

                        case VSOCKET_MULTICAST:
                        {
                                int val = 1;
                                if ( ::setsockopt(_fd, IPPROTO_IP, IP_MULTICAST_LOOP, (const char *)&val, sizeof(val)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IP_MULTICAST_LOOP)");
                                }

                                u_char ttl = 255; // Multicast TTL
                                if ( ::setsockopt(_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IP_MULTICAST_TTL)");
                                }

//                              u_char ittl = 255; // IP TTL
//                              if ( ::setsockopt(_fd, IPPROTO_IP, IP_TTL, &ittl, sizeof(ittl)) < 0 )
//                              {
//                                      throw vsocket_exception("setsockopt(IP_TTL)");
//                              }
                                break;
                        }

                        case VSOCKET_MULTICAST_V6:
                        {
                                int val = 1;
                                if ( ::setsockopt(_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const char *)&val, sizeof(val)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IPV6_MULTICAST_LOOP)");
                                }

                                u_char ttl = 255; // Multicast TTL
                                if ( ::setsockopt(_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IPV6_MULTICAST_HOPS)");
                                }
                                

//                              u_char ittl = 255; // IP TTL
//                              if ( ::setsockopt(_fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &ittl, sizeof(ittl)) < 0 )
//                              {
//                                      throw vsocket_exception("setsockopt(IPV6_HOPLIMIT)");
//                              }
                                break;
                        }
                }
        }

        void vsocket::vbind::unset(const vsocket::Option &o)
        {
                switch (o)
                {
                        case VSOCKET_REUSEADDR:
                        {
                                int on = 0;
                                if (::setsockopt(_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
                                {
                                        throw vsocket_exception("setsockopt(SO_REUSEADDR) failed");
                                }
                                break;
                        }

                        case VSOCKET_LINGER:
                        {
                                int set = 0;
                                ::setsockopt(_fd, IPPROTO_TCP, TCP_NODELAY, (char *)&set, sizeof(set));
                                break;
                        }

                        case VSOCKET_NODELAY:
                        {
                                // set linger option to the socket
                                struct linger linger;

                                linger.l_onoff = 0;
                                linger.l_linger = 0;
                                ::setsockopt(_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
                                break;
                        }

                        case VSOCKET_BROADCAST:
                        {
                                int b = 0;
                                if ( ::setsockopt(_fd, SOL_SOCKET, SO_BROADCAST, (char*)&b, sizeof(b)) == -1 )
                                {
                                        throw vsocket_exception("cannot disable broadcasts");
                                }
                        }

                        case VSOCKET_NONBLOCKING:
                        {
                                vsocket::set_non_blocking(_fd);
                                break;
                        }

                        case VSOCKET_MULTICAST:
                        {
                                int val = 0;
                                if ( ::setsockopt(_fd, IPPROTO_IP, IP_MULTICAST_LOOP, (const char *)&val, sizeof(val)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IP_MULTICAST_LOOP)");
                                }
                        }

                        case VSOCKET_MULTICAST_V6:
                        {
                                int val = 0;
                                if ( ::setsockopt(_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const char *)&val, sizeof(val)) < 0 )
                                {
                                        throw vsocket_exception("setsockopt(IPV6_MULTICAST_LOOP)");
                                }
                        }
                }
        }

        void vsocket::vbind::close()
        {
                if (_fd == -1) return;
                ::close(_fd);
                _fd = -1;
        }

        void vsocket::vbind::shutdown()
        {
                ::shutdown(_fd, SHUT_RDWR);
        }

        bool vsocket::vbind::operator==(const vbind &obj) const
        {
                if (obj._type != _type) return false;
                if (obj._port != _port) return false;
                if (obj._vaddress != _vaddress) return false;
                if (obj._file.getPath() != _file.getPath()) return false;

                return true;
        }

        void vsocket::vbind::check_socket_error(const int err) const
        {
                switch (err)
                {
                case EACCES:
                        throw vsocket_exception("Permission  to create a socket of the specified type and/or protocol is denied.");

                case EAFNOSUPPORT:
                        throw vsocket_exception("The implementation does not support the specified address family.");

                case EINVAL:
                        throw vsocket_exception("Unknown protocol, or protocol family not available.");

                case EMFILE:
                        throw vsocket_exception("Process file table overflow.");

                case ENFILE:
                        throw vsocket_exception("The system limit on the total number of open files has been reached.");

                case ENOBUFS:
                case ENOMEM:
                        throw vsocket_exception("Insufficient memory is available. The socket cannot be created until sufficient resources are freed.");

                case EPROTONOSUPPORT:
                        throw vsocket_exception("The protocol type or the specified protocol is not supported within this domain.");

                default:
                        throw vsocket_exception("cannot create socket");
                }
        }

        void vsocket::vbind::check_bind_error(const int err) const
        {
                switch ( err )
                {
                case EBADF:
                        throw vsocket_exception("sockfd ist kein gueltiger Deskriptor.");

                // Die  folgenden  Fehlermeldungen  sind  spezifisch fr UNIX-Domnensockets (AF_UNIX)

                case EINVAL:
                        throw vsocket_exception("Die addr_len war  falsch  oder  der  Socket  gehrte  nicht  zur AF_UNIX Familie.");

                case EROFS:
                        throw vsocket_exception("Die Socket \"Inode\" sollte auf einem schreibgeschtzten Dateisystem residieren.");

                case EFAULT:
                        throw vsocket_exception("my_addr  weist  auf  eine  Adresse  auerhalb  des  erreichbaren Adressraumes zu.");

                case ENAMETOOLONG:
                        throw vsocket_exception("my_addr ist zu lang.");

                case ENOENT:
                        throw vsocket_exception("Die Datei existiert nicht.");

                case ENOMEM:
                        throw vsocket_exception("Nicht genug Kernelspeicher vorhanden.");

                case ENOTDIR:
                        throw vsocket_exception("Eine Komponente des Pfad-Prfixes ist kein Verzeichnis.");

                case EACCES:
                        throw vsocket_exception("Keine  berechtigung  um  eine  Komponente  des Pfad-prefixes zu durchsuchen.");

                case ELOOP:
                        throw vsocket_exception("my_addr enthlt eine Kreis-Referenz (zum  Beispiel  durch  einen symbolischen Link)");

                default:
                        throw vsocket_exception("cannot bind socket");
                }
        }
}