/* xsh_udpecho.c - xsh_udpecho */

#include 
#include 
#include 

extern  int     atoi(char *);

/*------------------------------------------------------------------------
 * xsh_udpecho - shell command that can send a message to a remote UDP
 *                      echo server and receive a reply
 *------------------------------------------------------------------------
 */
shellcmd xsh_udpecho(int nargs, char *args[])
{
        int     i;                      /* Index into buffer            */
        int     retval;                 /* Return value                 */
        char    msg[] = "Xinu testing UDP echo"; /* Message to send     */
        char    inbuf[1500];            /* Buffer for incoming reply    */
        int32   slot;                   /* UDP slot to use              */
        int32   msglen;                 /* Length of outgoing message   */
        uint32  remoteip;               /* Remote IP address to use     */
        uint16  remport= 7;             /* Remote port number to use    */
        uint16  locport = 52743;        /* Local port to use            */
        int32   retries = 3;            /* Number of retries            */
        int32   delay   = 500;          /* Reception delay in ms        */

        /* For argument '--help', emit help about the 'udpecho' command */

        if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
                printf("Use: %s  remote_ip [remote_port]\n\n", args[0]);
                printf("Description:\n");
                printf("\tBounce a message off a remote UDP echo server\n");
                printf("Options:\n");
                printf("\tremote_ip:\tIP address in dotted decimal\n");
                printf("\tremote_port:\tport number\n");
                printf("\t--help\t\tdisplay this help and exit\n");
                return 0;
        }

        /* Check for valid IP address argument */

        if ( (nargs < 2) || (nargs > 3) ) {
                fprintf(stderr, "%s: invalid number of argument(s)\n", args[0]);
                fprintf(stderr, "Try '%s --help' for more information\n",
                                args[0]);
                return 1;
        }

        if (dot2ip(args[1], &remoteip) == SYSERR) {
                fprintf(stderr, "%s: invalid IP address argument\n",
                        args[0]);
                return 1;
        }
        if (nargs == 3) {
                retval = atoi(args[2]);
                if ( (retval <= 0) || (retval > 64535) ) {
                        fprintf(stderr, "%s: invalid port argument\n",
                                args[0]);
                        return 1;
                }
                remport = (uint16) retval;
        }

        fprintf(stderr, "using remote port %d\n", remport);

        /* Register local UDP port */

        slot = udp_register(remoteip, remport, locport);
        if (slot == SYSERR) {
                fprintf(stderr, "%s: could not reserve UDP port %d\n",
                                args[0], locport);
                return 1;
        }

        /* Retry sending outgoing datagram and getting response */

        msglen = strnlen(msg, 1200);
        for (i=0; i