IPV6 Simple Server Program

/**************************************************************************/
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>

#define SERVER_PORT     3005
#define BUFFER_LENGTH    250
#define FALSE              0

void main()
{
                int sd=-1, sdconn=-1;
                int rc, on=1, rcdsize=BUFFER_LENGTH;
                char buffer[BUFFER_LENGTH];
                struct sockaddr_in6 serveraddr, clientaddr;
                int addrlen=sizeof(clientaddr);
                char str[INET6_ADDRSTRLEN];

                do
                {
                                if ((sd = socket(AF_INET6, SOCK_STREAM, 0)) < 0)
                                {
                                                perror("socket() failed");
                                                break;
                                }

                                if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR,
                                                                                (char *)&on,sizeof(on)) < 0)
                                {
                                                perror("setsockopt(SO_REUSEADDR) failed");
                                                break;
                                }

                                memset(&serveraddr, 0, sizeof(serveraddr));
                                serveraddr.sin6_family = AF_INET6;
                                serveraddr.sin6_port   = htons(SERVER_PORT);

                                serveraddr.sin6_addr   = in6addr_any;
  if (bind(sd,
                                                                                (struct sockaddr *)&serveraddr,
                                                                                sizeof(serveraddr)) < 0)
                                {
                                                perror("bind() failed");
                                                break;
                                }

                                if (listen(sd, 128) < 0)
                                {
                                                perror("listen() failed");
                                                break;
                                }

                                printf("Ready for client connect().\n");

                                addrlen=sizeof(clientaddr);
                                if ((sdconn = accept(sd, (struct sockaddr *)&clientaddr, &addrlen)) < 0)
                                {
                                                perror("accept() failed");
                                                break;
                                }
                                else
                                {
                                                //getpeername(sdconn, (struct sockaddr *)&clientaddr, &addrlen);
                                                if(inet_ntop(AF_INET6, &clientaddr.sin6_addr, str, sizeof(str))) {
                                                                printf("Client address is %s\n", str);
                                                                printf("Client IP Family [%d]\n", clientaddr.sin6_family);
                                                                printf("Client port is %d\n", ntohs(clientaddr.sin6_port));
                                                }
                                }

                                /********************************************************************/
                                /* In this example we know that the client will send 250 bytes of   */
                                /* data over.  Knowing this, we can use the SO_RCVLOWAT socket      */
                                /* option and specify that we don't want our recv() to wake up      */
                                /* until all 250 bytes of data have arrived.                        */
                                /********************************************************************/
                                if (setsockopt(sdconn, SOL_SOCKET, SO_RCVLOWAT,
                                                                                (char *)&rcdsize,sizeof(rcdsize)) < 0)
                                {
                                                perror("setsockopt(SO_RCVLOWAT) failed");
                                                break;
  }

                                rc = recv(sdconn, buffer, sizeof(buffer), 0);
                                if (rc < 0)
                                {
                                                perror("recv() failed");
                                                break;
                                }

                                printf("%d bytes of data were received\n", rc);
                                if (rc == 0 ||
                                                                rc < sizeof(buffer))
                                {
                                                printf("The client closed the connection before all of the\n");
                                                printf("data was sent\n");
                                                break;
                                }

                                rc = send(sdconn, buffer, sizeof(buffer), 0);
                                if (rc < 0)
                                {
                                                perror("send() failed");
                                                break;
                                }

                } while (FALSE);

                if (sd != -1)
                                close(sd);
                if (sdconn != -1)
                                close(sdconn);
}