/*** IBMCOPYR ********************************************************/
/*                                                                   */
/* Component Name: TCPS                                              */
/*                                                                   */
/*                                                                   */
/* Copyright:    Licensed Materials - Property of IBM                */
/*                                                                   */
/*               "Restricted Materials of IBM"                       */
/*                                                                   */
/*               5647-A01                                            */
/*                                                                   */
/*               (C) Copyright IBM Corp. 1977, 1998                  */
/*                                                                   */
/*               US Government Users Restricted Rights -             */
/*               Use, duplication or disclosure restricted by        */
/*               GSA ADP Schedule Contract with IBM Corp.            */
/*                                                                   */
/* Status:       CSV2R6                                              */
/*                                                                   */
/*  SMP/E Distribution Name: EZAEC01X                                */
/*                                                                   */
/*** IBMCOPYR ********************************************************/

static char ibmcopyr[] =
   "TCPS     - Licensed Materials - Property of IBM. "
   "This module is \"Restricted Materials of IBM\" "
   "5647-A01 (C) Copyright IBM Corp. 1996. "
   "See IBM Copyright Instructions.";

#include <manifest.h>
#include <bsdtypes.h>
#include <socket.h>
#include <in.h>
#include <netdb.h>
#include <stdio.h>


/*
 * Server Main.
 */
main(argc, argv)
int argc;
char **argv;
{
    unsigned short port;       /* port server binds to                */
    char buf[12];              /* buffer for sending & receiving data */
    struct sockaddr_in client; /* client address information          */
    struct sockaddr_in server; /* server address information          */
    int s;                     /* socket for accepting connections    */
    int ns;                    /* socket connected to client          */
    int namelen;               /* length of client name               */

    /*
     * Check arguments. Should be only one: the port number to bind to.
     */

    if (argc != 2)
    {
        fprintf(stderr, "Usage: %s port\n", argv[0]);
        exit(1);
    }

    /*
     * First argument should be the port.
     */
    port = (unsigned short) atoi(argv[1]);

    /*
     * Get a socket for accepting connections.
     */
    if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        tcperror("Socket()");
        exit(2);
    }

    /*
     * Bind the socket to the server address.
     */
    server.sin_family = AF_INET;
    server.sin_port   = htons(port);
    server.sin_addr.s_addr = INADDR_ANY;

    if (bind(s, (struct sockaddr *)&server, sizeof(server)) < 0)
    {
        tcperror("Bind()");
        exit(3);
    }

    /*
     * Listen for connections. Specify the backlog as 1.
     */
    if (listen(s, 1) != 0)
    {
        tcperror("Listen()");
        exit(4);
    }

    /*
     * Accept a connection.
     */
    namelen = sizeof(client);
    if ((ns = accept(s, (struct sockaddr *)&client, &namelen)) == -1)
    {
        tcperror("Accept()");
        exit(5);
    }

    /*
     * Receive the message on the newly connected socket.
     */
    if (recv(ns, buf, sizeof(buf), 0) == -1)
    {
        tcperror("Recv()");
        exit(6);
    }

    /*
     * Send the message back to the client.
     */
    if (send(ns, buf, sizeof(buf), 0) < 0)
    {
        tcperror("Send()");
        exit(7);
    }

    close(ns);
    close(s);

    printf("Server ended successfully\n");
    exit(0);
}