DNStest.c File Reference

Performs a DNS-lookup to get the IP-address from www.dsignt.de. More...

#include <BoardSupport/inc/stdtypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <inttypes.h>
#include <time.h>
#include <string.h>
#include <Libs/NETlib/net.h>
#include <BoardSupport/inc/BoardSpecific.h>
#include <Common/Common.h>
#include <Common/uartio.h>
#include <Common/timer.h>
#include <Common/CPrintf.h>
#include <BoardSupport/config/netconfig.c>

Macros
#define	MAX_PING_DATA   100
#define	HOST_NAME   "www.dsignt.de"

Functions
uint32_t	resolve_name (char *hostname, int max_retry)
int	main (void)

Variables
char *	program_name = "DNS"

Detailed Description

                          _         _             _
                       __| |    ___(_) ____ _ __ | |_
                      / _` |   / __| |/ _` | '_ \| __|
                     | (_| | _ \__ \ | (_| | | | | |_
                      \__,_|(_) ___/_|\__, |_| |_|\__|
                     Signalprocessing |___/ Technology

Author

D.SignT GmbH & Co. KG, Claus Hermbusche

Date

2019-06-04

The main DNS resolution is performed by function resolve_name():

host_address = resolve_name ("www.dsignt.de", 6);

The returned IP-address may be used for informational purpose or for creating a socket:

tcp_socket = socket_open (inet_ntoa (host_address, buffer),
                          ANY_PORT,
                          5031,
                          DATATYPE_CHAR,
                          TCP_INIT_FUNC);

Note

The DNS-lookup is already included with socket_open() function. For the same result as described above you can simply call:

tcp_socket = socket_open ("www.dsignt.de",
                          ANY_PORT,
                          5031,
                          DATATYPE_CHAR,
                          TCP_INIT_FUNC);

Macro Definition Documentation

#define MAX_PING_DATA   100

#define HOST_NAME   "www.dsignt.de"

Examples:

DNSTest.c.

Function Documentation

uint32_t resolve_name	(	char *	hostname,
		int	max_retry
	)

Examples:

DNSTest.c.

{
    /***************************************************************************
     locals
    ***************************************************************************/
    uint32_t ret = UINT32_C(0);
    int32_t timeout;
    int i;

    for ( i = 0; i < max_retry ; i++ )
    {
        CPrintChar ('.', 1);

        /***********************************************************************
          configure timeout value to break the action if name resolution is not
          possible
        ***********************************************************************/
        timeout = 500000;

        /***********************************************************************
          resolve address:
        ***********************************************************************/
        ret = gethostbyname (hostname, &timeout);

        if ( ret ) // on success stop loop
        {
            break;
        }
    }

    return (ret);
}

int main

(

void

)

{
    /***************************************************************************
     locals
    ***************************************************************************/
    int main_loop = 1;                /* main loop switch, set to 0 to exit   */
    timeval stamp1, stamp2, delta;    /* used to determine startup time       */
    uint32_t host_address;
    char buffer[20];

    /***************************************************************************
      initialize application (e.g. timer clocks, PLL settings, EMIF etc.)
       (ref. \Common\Common.c)
    ***************************************************************************/
    AppInit (GET_CLOCK);

    /***************************************************************************
      select output device for CPrintf  (ref. \Common\cprintf.c)
      possible settings:
        CPRINTF_UART_OUTPUT                       -> output to UART
        CPRINTF_CCS_OUTPUT                        -> output to CCS
        CPRINTF_UART_OUTPUT | CPRINTF_CCS_OUTPUT  -> output to UART and CCS
    ***************************************************************************/
    CPrintf_select_output (CPRINTF_DEFAULT_OUTPUT);  /* default outputs       */

    /***************************************************************************
     print a start up message
    ***************************************************************************/
    START_UP_MESSAGE (BLANK_REV NETLIB_REV);

    /**************************************************************************/
    // CPrintfProgress (" Heap check ");
    // at least 0x2000 bytes required for this app
    /**************************************************************************/
    ASSERT_HEAP (initial_heap_size, 0x2000);
    // CPrintfProgressSuccess();

    /**************************************************************************/
     CPrintfProgress (" Setup system time ");
     // 1 milli seconds resolution
    /**************************************************************************/
    SetupSystemTime ( SYSTEM_TIMER_INT, SYSTEM_TIMER, RES_MSECONDS);
    CPrintfProgressSuccess();
    CPrintf ("   *** timer %d mapped to CPU int %d ***\r\n",
             SystemTimerDev, SYSTEM_TIMER_INT);

    /**************************************************************************/
     CPrintfProgress (" Enable interrupts ");
    /**************************************************************************/
    BoardEnableInterrupts();
    CPrintfProgressSuccess();

    /**************************************************************************/
     CPrintfProgress (" Start system timer ");
    /**************************************************************************/
    StartSystemTimer ();
    CPrintfProgressSuccess();
    CPrintf ("   *** timer %d running at %"PRId32" Hz ***\r\n", SystemTimerDev, RES_SECONDS/GetSystemTimerRes());

    /***************************************************************************
      measure network initialization time
    ***************************************************************************/
    stamp1 = GetTimeStamp();

    /**************************************************************************/
     CPrintfProgress (" Initialize network ");
    /**************************************************************************/
    InitializeNetwork ( MAX_PING_DATA); // MAX_PING_DATA bytes for ping
    CPrintfProgressSuccess();

    stamp2 = GetTimeStamp();

    tv_interval (&delta, &stamp1, &stamp2);
    CPuts (" network startup time [sec]: ");
    CPrintf (VT100_RED
             "%"PRId32".%03"PRId32"\r\n"
             VT100_DEFAULT,
              delta.tv_sec,
              delta.tv_usec/1000);


    /***************************************************************************
     wait for link and IP address
    ***************************************************************************/
    while ((_link == 0) || (get_ip_address (0) == UINT32_C(0)))
    {
        /***********************************************************************
         perform progress bar animation each 200 milli second
        ***********************************************************************/
        CPrintProgressBarText  ('.', 200000, 16,  " waiting for link");

        net_isq ();

        /***********************************************************************
         monitor link status
        ***********************************************************************/
        monitor_link_status (CPrintf);
    }

    CPrintf ("success\r\n try to resolve %s...\r\n", HOST_NAME);

    /***************************************************************************
      resolve DSignT's IP
    ***************************************************************************/
    host_address = resolve_name (HOST_NAME, 6);

    if ( host_address == 0L )
    {
        CPuts (" address can not be resolved\r\n");
    }
    else
    {
        CPrintf (" resolved IP-address for %s: %s\r\n",
                HOST_NAME,
                inet_ntoa (host_address, buffer));
    }

    /***************************************************************************
      main program loop: set main_loop to 0 to exit loop
    ***************************************************************************/
    while ( main_loop )
    {
        net_isq ();

        /***********************************************************************
         show that the program is running, perform symbol animation
        ***********************************************************************/
        CPrintAnimatedSymbol ( sym_animate, 200000, ANIMATE_SYMBOLS_COUNT);
    }

    /***************************************************************************
      exit program, shut down peripherals
    ***************************************************************************/
    return (0);
}

Variable Documentation

char* program_name = "DNS"