    /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
    /*
     * This file is part of the LibreOffice project.
     *
     * This Source Code Form is subject to the terms of the Mozilla Public
     * License, v. 2.0. If a copy of the MPL was not distributed with this
     * file, You can obtain one at http://mozilla.org/MPL/2.0/.
     */

    #include <errno.h>
    #include <stdlib.h>
    #include <string.h>
    #include <algorithm>
    #include <vector>
    #include <iostream>

    #include <rtl/strbuf.hxx>
    #include <config_features.h>
    #include <sal/log.hxx>

    #include "DiscoveryService.hxx"

    #ifdef _WIN32
      // LO vs WinAPI conflict
      #undef WB_LEFT
      #undef WB_RIGHT

      #include <winsock2.h>
      #include <ws2tcpip.h>

      #include "WINNetworkService.hxx"
      typedef int socklen_t;
    #else
      #include <unistd.h>
      #include <sys/types.h>
      #include <sys/socket.h>
      #include <netinet/in.h>
      #include <arpa/inet.h>
    #endif

    #ifdef MACOSX
      #include <osl/conditn.hxx>
      #include <premac.h>
      #import <CoreFoundation/CoreFoundation.h>
      #include <postmac.h>
      #import "OSXNetworkService.hxx"
    #endif

    #if HAVE_FEATURE_AVAHI
      #include "AvahiNetworkService.hxx"
    #endif

    using namespace osl;
    using namespace sd;

    DiscoveryService::DiscoveryService()
        : mSocket(-1)
        , zService(nullptr)
    {
    }

    DiscoveryService::~DiscoveryService()
    {
        if (mSocket != -1)
        {
    #ifdef _WIN32
            closesocket( mSocket );
    #else
            close( mSocket );
    #endif
        }

         if (zService)
             zService->clear();
    }

    void DiscoveryService::setupSockets()
    {

    #ifdef MACOSX
        // Bonjour for OSX
        zService = new OSXNetworkService();
    #endif

    #if HAVE_FEATURE_AVAHI
        // Avahi for Linux
        char hostname[1024];
        hostname[1023] = '\0';
        gethostname(hostname, 1023);

        zService = new AvahiNetworkService(hostname);
    #endif

    #ifdef _WIN32
        zService = new WINNetworkService();
    #endif

        if (zService)
            zService->setup();

        // Old implementation for backward compatibility matter
        mSocket = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
        if (mSocket == -1)
        {
            SAL_WARN("sd", "DiscoveryService: socket failed: " << errno);
            return; // would be better to throw, but unsure if caller handles that
        }

        sockaddr_in aAddr;
        memset(&aAddr, 0, sizeof(aAddr));
        aAddr.sin_family = AF_INET;
        aAddr.sin_addr.s_addr = htonl(INADDR_ANY);
        aAddr.sin_port = htons( PORT_DISCOVERY );

        int rc = bind( mSocket, reinterpret_cast<sockaddr*>(&aAddr), sizeof(sockaddr_in) );

        if (rc)
        {
            SAL_WARN("sd", "DiscoveryService: bind failed: " << errno);
            return; // would be better to throw, but unsure if caller handles that
        }

        struct ip_mreq multicastRequest;

    // the Win32 SDK 8.1 deprecates inet_addr()
    #if defined(_WIN32)
        IN_ADDR addr;
        INT ret = InetPtonW(AF_INET, L"239.0.0.1", & addr);
        if (1 == ret)
        {
            multicastRequest.imr_multiaddr.s_addr = addr.S_un.S_addr;
        }
    #else
        multicastRequest.imr_multiaddr.s_addr = inet_addr( "239.0.0.1" );
    #endif
        multicastRequest.imr_interface.s_addr = htonl(INADDR_ANY);

        rc = setsockopt( mSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP,
        #ifdef _WIN32
            reinterpret_cast<const char*>(&multicastRequest),
        #else
            &multicastRequest,
        #endif
            sizeof(multicastRequest));

        if (rc)
        {
            SAL_WARN("sd", "DiscoveryService: setsockopt failed: " << errno);
            return; // would be better to throw, but unsure if caller handles that
        }
    }

    void SAL_CALL DiscoveryService::run()
    {
        osl::Thread::setName("DiscoveryService");

        setupSockets();

        // Kept for backward compatibility
        char aBuffer[BUFFER_SIZE];
        while ( true )
        {
            memset( aBuffer, 0, sizeof(char) * BUFFER_SIZE );
            sockaddr_in aAddr;
            socklen_t aLen = sizeof( aAddr );
            if(recvfrom( mSocket, aBuffer, BUFFER_SIZE, 0, reinterpret_cast<sockaddr*>(&aAddr), &aLen ) > 0)
            {
                OString aString( aBuffer, strlen( "LOREMOTE_SEARCH" ) );
                if ( aString == "LOREMOTE_SEARCH" )
                {
                    OStringBuffer aStringBuffer("LOREMOTE_ADVERTISE\n");
                    aStringBuffer.append( OUStringToOString(
                                                  osl::SocketAddr::getLocalHostname(), RTL_TEXTENCODING_UTF8 ) )
                        .append( "\n\n" );
                    if ( sendto( mSocket, aStringBuffer.getStr(),
                                 aStringBuffer.getLength(), 0, reinterpret_cast<sockaddr*>(&aAddr),
                                 sizeof(aAddr) ) <= 0 )
                    {
                        // Write error or closed socket -- we are done.
                        return;
                    }
                }
            }
            else
            {
                // Read error or closed socket -- we are done.
                return;
            }
        }
    }

    DiscoveryService *sd::DiscoveryService::spService = nullptr;

    void DiscoveryService::setup()
    {
      if (spService)
        return;

      spService = new DiscoveryService();
      spService->create();
    }

    /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

↑ V668 There is no sense in testing the 'zService' pointer against null, as the memory was allocated using the 'new' operator. The exception will be generated in the case of memory allocation error.