#pragma	module	tcpip$tcp_server_qio			\
		"V5.4-00"

/*
 * © Copyright 1976, 2003 Hewlett-Packard Development Company, L.P.
 *
 * Confidential computer software.  Valid license  from  HP  and/or its
 * subsidiaries required for possession, use, or copying.
 *
 * Consistent with FAR 12.211 and 12.212, Commercial Computer Software,
 * Computer Software Documentation,  and  Technical Data for Commercial
 * Items  are  licensed to the U.S. Government under vendor's  standard
 * commercial license.
 *
 * Neither HP nor any of its subsidiaries shall be liable for technical
 * or editorial errors or omissions contained herein.   The information
 * in  this document is provided  "as is"  without warranty of any kind
 * and is subject  to  change  without  notice.   The warranties for HP
 * products are set forth in the express  limited  warranty  statements
 * accompanying such products.   Nothing herein should be construed  as
 * constituting an additional warranty.
 *
 * ++
 * FACILITY:
 *
 *    EXAMPLES
 *      
 * ABSTRACT:
 *
 *    This is an example of a TCP/IP IPv4 server using  OpenVMS
 *    QIO system services to handle network I/O operations.
 *
 *    Refer to 'Build, Configuration, and Run Instructions' for
 *    details on how to build, configure, and run this program.
 *
 * ENVIRONMENT:
 *
 *    OpenVMS Alpha/VAX V7.1
 *    TCP/IP Services V5.0 or higher
 *
 * AUTHOR:
 *
 *    TCPIP Development Group,  CREATION DATE: 23-May-1989
 *
 * --
 */

	/* Build, Configuration, and Run Instructions */

/*
 *  BUILD INSTRUCTIONS:
 *
 *    To build this example program use commands of the form,
 *
 *    using the "C" compiler:
 *
 *	$ cc/prefix=all TCPIP$TCP_SERVER_QIO.C
 *      $ link TCPIP$TCP_SERVER_QIO
 *
 *
 * CONFIGURATION INSTRUCTIONS:
 *
 *    No special configuration required.
 *
 *
 * RUN INSTRUCTIONS:
 *
 *    To run this example program:
 *
 *    1) Start this server program as shown below:
 *
 *	 $ run tcpip$tcp_server_qio
 *	 Waiting for a client connection on port: m
 *
 *    2) After the server program blocks, start the client program,
 *       entering the server host as shown below:
 *
 *	 $ run tcpip$tcp_client_qio
 *	 Enter remote host:
 *
 *	 Note: You can specify a server host by using either an IPv4
 *	       address in dotted-decimal notation (e.g. 16.20.10.56)
 *	       or a host domain name (e.g. serverhost.hp.com).
 *
 *    3) The server program then displays client connection information
 *       and client data as shown below:
 *
 *	 Accepted connection from host: a.b.c.d, port: n
 *	 Data sent: Hello, world!
 *
 *    You can enter "ctrl/z" at any user prompt to terminate program
 *    execution.
 *    
 */


/*
 * INCLUDE FILES:
 */

#include <descrip.h>		    /* define OpenVMS descriptors	    */

#include <efndef.h>		    /* define 'EFN$C_ENF' event flag	    */

#include <in.h>			    /* define internet related constants,   */
				    /* functions, and structures	    */
#include <inet.h>		    /* define network address info	    */
#include <iodef.h>		    /* define i/o function codes	    */

#include <netdb.h>		    /* define network database library info */

#include <ssdef.h>		    /* define system service status codes   */
#include <starlet.h>		    /* define system service calls	    */
#include <stdio.h>		    /* define standard i/o functions	    */
#include <stdlib.h>		    /* define standard library functions    */
#include <string.h>		    /* define string handling functions	    */
#include <stsdef.h>		    /* define condition value fields	    */

#include <tcpip$inetdef.h>	    /* define tcp/ip network constants,	    */
				    /* structures, and functions	    */


/*
 * NAMED CONSTANTS:
 */

#define	SERV_BACKLOG	1		/* server backlog		    */
#define	SERV_PORTNUM	12345		/* server port number		    */


/*
 * STRUCTURE DEFINITIONS:
 */

struct iosb
    {					/* i/o status block		    */
    unsigned short status;		/* i/o completion status	    */
    unsigned short bytcnt;		/* bytes transferred if read/write  */
    void *details;			/* address of buffer or parameter   */
    };

struct itemlst_2
    {					/* item-list 2 descriptor/element   */
    unsigned short length;		/* length			    */
    unsigned short type;		/* parameter type		    */
    void *address;			/* address of item list		    */
    };

struct itemlst_3
    {					/* item-list 3 descriptor/element   */
    unsigned short length;		/* length			    */
    unsigned short type;		/* parameter type		    */
    void *address;			/* address of item list		    */
    unsigned int *retlen;		/* address of returned length	    */
    };

struct sockchar
    {					/* socket characteristics buffer    */
    unsigned short prot;		/* protocol			    */
    unsigned char type;			/* type				    */
    unsigned char af;			/* address format		    */
    };


/*
 * FORWARD REFERENCES:
 */

int  main( void );			/* server main			    */

	/* Server Main */

/*
 * FUNCTIONAL DESCRIPTION:
 *
 *    This is the server's main-line code. It handles all the tasks of the
 *    server including: socket creation, accepting and/or rejecting client
 *    connections, writing client connection data,  and terminating client
 *    connections.
 *
 *    This example program implements a typical TCP IPv4 server using  QIO
 *    system services to handle network i/o operations as shown below:
 *
 *	1) To create a socket and set REUSEADDR option:
 *
 *	   sys$assign() and sys$qiow(IO$_SETMODE)
 *
 *	2) To bind internet address and port number to a socket:
 *
 *	   sys$qiow(IO$_SETMODE)
 *
 *	3) To accept a connection request:
 *
 *	   sys$qiow(IO$_ACCESS|IO$M_ACCEPT)
 *
 *	4) To transfer data:
 *
 *	   sys$qiow(IO$_WRITEVBLK)
 *
 *	5) To shutdown a socket:
 *
 *	   sys$qiow(IO$_DEACCESS|IO$M_SHUTDOWN)
 *
 *	6) To close and delete a socket:
 *
 *	   sys$qiow(IO$_DEACCESS) and sys$dassgn()
 *
 *    This function is invoked by the DCL "RUN" command (see below);  the
 *    function's  completion  status is interpreted by DCL and if needed,
 *    an error message is displayed.
 *
 * SYNOPSIS:
 *
 *    int main( void )
 *
 * FORMAL PARAMETERS:
 *
 *    ** None **
 *
 * IMPLICIT INPUTS:
 *
 *    ** None **
 *
 * IMPLICIT OUTPUTS:
 *
 *    ** None **
 *
 * FUNCTION VALUE:
 *
 *    completion status
 *
 * SIDE EFFECTS:
 *
 *    ** None **
 *
 */ 

int
main( void )
{
    int	one = 1;			/* reuseaddr option value	    */

    struct iosb iosb;			/* i/o status block		    */

    unsigned int status;		/* system service return status	    */

    unsigned short conn_channel;	/* connect inet device i/o channel  */
    unsigned short listen_channel;	/* listen inet device i/o channel   */

    struct sockchar listen_sockchar;	/* listen socket char buffer	    */

    unsigned int client_retlen;		/* returned length of client socket */
					/* address structure		    */
    struct sockaddr_in client_addr;	/* client socket address structure  */
    struct itemlst_3 client_itemlst;	/* client item-list 3 descriptor    */

    struct sockaddr_in serv_addr;	/* server socket address structure  */
    struct itemlst_2 serv_itemlst;	/* server item-list 2 descriptor    */

    struct itemlst_2 sockopt_itemlst;	/* sockopt item-list 2 descriptor   */
    struct itemlst_2 reuseaddr_itemlst;	/* reuseaddr item-list 2 element    */

    char buf[] = "Hello, world!";	/* server data buffer		    */
    int  buflen = sizeof( buf );	/* length of server data buffer	    */

    $DESCRIPTOR( inet_device,		/* string descriptor with logical   */
		 "TCPIP$DEVICE:" );	/* name of internet pseudodevice    */

    /*
     * init listen socket characteristics buffer
     */

    listen_sockchar.prot = TCPIP$C_TCP;
    listen_sockchar.type = TCPIP$C_STREAM;
    listen_sockchar.af   = TCPIP$C_AF_INET;

    /*
     * init reuseaddr's item-list element
     */

    reuseaddr_itemlst.length  = sizeof( one );
    reuseaddr_itemlst.type    = TCPIP$C_REUSEADDR;
    reuseaddr_itemlst.address = &one;

    /*
     * init sockopt's item-list descriptor
     */

    sockopt_itemlst.length  = sizeof( reuseaddr_itemlst );
    sockopt_itemlst.type    = TCPIP$C_SOCKOPT;
    sockopt_itemlst.address = &reuseaddr_itemlst;

    /*
     * init client's item-list descriptor
     */

    memset( &client_itemlst, 0, sizeof(client_itemlst) );
    client_itemlst.length  = sizeof( client_addr );
    client_itemlst.address = &client_addr;
    client_itemlst.retlen  = &client_retlen;

    /*
     * init client's socket address structure
     */

    memset( &client_addr, 0, sizeof(client_addr) );

    /*
     * init server's item-list descriptor
     */

    serv_itemlst.length  = sizeof( serv_addr );
    serv_itemlst.type	 = TCPIP$C_SOCK_NAME;
    serv_itemlst.address = &serv_addr;

    /*
     * init server's socket address structure
     */

    memset( &serv_addr, 0, sizeof(serv_addr) );
    serv_addr.sin_family      = TCPIP$C_AF_INET;
    serv_addr.sin_port	      = htons( SERV_PORTNUM );
    serv_addr.sin_addr.s_addr = TCPIP$C_INADDR_ANY;

    /*
     * assign device sockets
     */

    status = sys$assign( &inet_device,	    /* device name		    */
			 &listen_channel,   /* i/o channel		    */
			 0,		    /* access mode		    */
			 0		    /* not used			    */
		       );

    if ( (status & STS$M_SUCCESS) )
	status = sys$assign( &inet_device,  /* device name		    */
			     &conn_channel, /* i/o channel		    */
			     0,		    /* access mode		    */
			     0		    /* not used			    */
		       );

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to assign i/o channel(s) to TCPIP device\n" );
	exit( status );
	}

    /*
     * create a listen socket
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       listen_channel,	    /* i/o channel		    */
		       IO$_SETMODE,	    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       &listen_sockchar,    /* p1 - socket char buffer	    */
		       0,		    /* p2			    */
		       0,		    /* p3			    */
		       0,		    /* p4			    */
		       &sockopt_itemlst,    /* p5 - socket options	    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to create socket\n" );
	exit( status );
	}

    /*
     * bind server's internet address and port number to
     * listen socket; set socket as a passive socket
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       listen_channel,	    /* i/o channel		    */
		       IO$_SETMODE,	    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       0,		    /* p1			    */
		       0,		    /* p2			    */
		       &serv_itemlst,	    /* p3 - local socket name	    */
		       SERV_BACKLOG,	    /* p4 - connection backlog	    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to bind socket\n" );
	exit( status );
	}

    /*
     * accept a connection from a client
     */

    printf( "Waiting for a client connection on port: %d\n",
	    ntohs(serv_addr.sin_port)
	  );

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       listen_channel,	    /* i/o channel		    */
		       IO$_ACCESS|IO$M_ACCEPT,
					    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       0,		    /* p1			    */
		       0,		    /* p2			    */
		       &client_itemlst,	    /* p3 - remote socket name	    */
		       &conn_channel,	    /* p4 - i/o channel for new	    */
					    /*      connection		    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to accept client connection\n" );
	exit( status );
	}

    printf( "Accepted connection from host: %s, port: %d\n",
	    inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port)
	  );

    /*
     * connection established with a client;
     * now attempt to write on this connection
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       conn_channel,	    /* i/o channel		    */
		       IO$_WRITEVBLK,	    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       buf,		    /* p1 - buffer address	    */
		       buflen,		    /* p2 - buffer length	    */
		       0,		    /* p3			    */
		       0,		    /* p4			    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to write data to client connection\n" );
	exit( status );
	}

    printf( "Data sent: %s\n", buf );	    /* output server's data buffer  */

    /*
     * shutdown connection socket
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       conn_channel,	    /* i/o channel		    */
		       IO$_DEACCESS|IO$M_SHUTDOWN,
					    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       0,		    /* p1			    */
		       0,		    /* p2			    */
		       0,		    /* p3			    */
		       TCPIP$C_DSC_ALL,	    /* p4 - discard all packets	    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to shutdown client connection\n" );
	exit( status );
	}

    /*
     * close connection socket
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       conn_channel,	    /* i/o channel		    */
		       IO$_DEACCESS,	    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       0,		    /* p1			    */
		       0,		    /* p2			    */
		       0,		    /* p3			    */
		       0,		    /* p4			    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to close socket\n" );
	exit( status );
	}

    /*
     * close listen socket
     */

    status = sys$qiow( EFN$C_ENF,	    /* event flag		    */
		       listen_channel,	    /* i/o channel		    */
		       IO$_DEACCESS,	    /* i/o function code	    */
		       &iosb,		    /* i/o status block		    */
		       0,		    /* ast service routine	    */
		       0,		    /* ast parameter		    */
		       0,		    /* p1			    */
		       0,		    /* p2			    */
		       0,		    /* p3			    */
		       0,		    /* p4			    */
		       0,		    /* p5			    */
		       0		    /* p6			    */
		     );

    if ( status & STS$M_SUCCESS )
	status = iosb.status;

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to close socket\n" );
	exit( status );
	}

    /*
     * deassign all device sockets
     */

    status = sys$dassgn( conn_channel );

    if ( (status & STS$M_SUCCESS) )
	status = sys$dassgn( listen_channel );

    if ( !(status & STS$M_SUCCESS) )
	{
	printf( "Failed to deassign i/o channel(s) to TCPIP device\n" );
	exit( status );
	}

    exit( EXIT_SUCCESS );
}