场景

        需要开发一个服务器发现模块，等待客户端的探测报文。在Linux服务器下组播地址imr_interface可以不绑定

 mcast.imr_multiaddr.s_addr = inet_addr(“239.255.255.250”);
 mcast.imr_interface.s_addr = htonl(INADDR_ANY);

但是在windwos服务器下必须绑定一个指定的IP地址，否则无法收到任何的组播探测包

具体代码

//加入设备组，设备发现
DWORD WINAPI OnvifBeDiscovered(LPVOID p)
{
 struct soap UDPserverSoap;
 struct ip_mreq mcast;

 soap_init1(&UDPserverSoap, SOAP_IO_UDP | SOAP_XML_IGNORENS);
 soap_set_namespaces(&UDPserverSoap, namespaces);

 SOAP_SOCKET localSocket = soap_bind(&UDPserverSoap, NULL, 3702, 10);
 if (!soap_valid_socket(localSocket))
 {
  soap_print_fault(&UDPserverSoap, stderr);
  exit(1);
 }

 mcast.imr_multiaddr.s_addr = inet_addr(“239.255.255.250”);
 mcast.imr_interface.s_addr = inet_addr(“192.168.58.173”);
 //IP_ADD_MEMBERSHIP用于加入某个多播组，之后就可以向这个多播组发送数据或者从多播组接收数据
 if (setsockopt(UDPserverSoap.master, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&mcast, sizeof(mcast)) < 0)
 {
  printf(“setsockopt error! error code = %d,err string = %s\n”, errno, strerror(errno));
  return 0;
 }

 SOAP_SOCKET clientSocket = -1;
 while (1)
 {
  clientSocket = soap_accept(&UDPserverSoap);
  if (!soap_valid_socket(clientSocket))
  {
   soap_print_fault(&UDPserverSoap, stderr);
   exit(1);
  }

  if (soap_serve(&UDPserverSoap) != SOAP_OK)
  {
   soap_print_fault(&UDPserverSoap, stderr);
  }
  soap_destroy(&UDPserverSoap);
  soap_end(&UDPserverSoap);
 }
 soap_done(&UDPserverSoap);
}