#include "def"
main(int argc, char *argv[])
{
   int                                     listenfd, connfd;
   socklen_t                       len;
   struct sockaddr_in6      servaddr, cliaddr;
   char                            buff[1024];
   time_t                          ticks;

   if (argc != 2) {                                     
        printf("usage %s <port>\n", argv[0]);           
        exit (-1);                                      
   } 

   listenfd = socket (AF_INET6,SOCK_STREAM,IPPROTO_SCTP);
   servaddr.sin6_family = AF_INET6;
   servaddr.sin6_addr   = in6addr_any;
   servaddr.sin6_port = htons(atoi(argv[1]));

   if (   bind( listenfd, (SA *) &servaddr, sizeof(servaddr) ) < 0 ){
      printf("error binding\n");
      exit(-1) ;
   }

   listen(listenfd,1);
   for ( ; ; ) {
      len = sizeof(cliaddr);
      connfd = accept(listenfd, (SA *) &cliaddr, &len);
      printf("connection from %s, port %d\n",
          inet_ntop(AF_INET6, &cliaddr.sin6_addr, buff, sizeof(buff)), 
          ntohs(cliaddr.sin6_port));
      len = sizeof(cliaddr);
      getsockname(connfd, (SA *) &cliaddr, &len);
      printf("my end: %s, port %d\n",
          inet_ntop(AF_INET6, &cliaddr.sin6_addr, buff, sizeof(buff)), 
          ntohs(cliaddr.sin6_port));

      len = sizeof(cliaddr);
      getpeername(connfd, (SA *) &cliaddr, &len);
      printf("peer end: from %s, port %d\n",
          inet_ntop(AF_INET6, &cliaddr.sin6_addr, buff, sizeof(buff)), 
          ntohs(cliaddr.sin6_port));

      ticks = time(NULL);
      snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
      write(connfd, buff, strlen(buff));
      printf("wrote the date as %s\n", buff);
      close(connfd);
   }
}