Id:: pppc.c 3538 2011-08-10 16:34:10Z haraldkipp
PPP client sample.
This example demonstrates Nut/OS Point-To-Point protocol. Most likely it will not run without modification. See the '#define' entries below.
The application will dial the provider via a modem, using the specified chat script. When connected, it will establish a PPP session. Then DNS is used to query the IP address of an NTP server, from which it queries the current time. Finally the PPP session is terminated and the whole procedure is repeated every hour.
By default the application will use 2 serial ports. The first one is used for debugging output on stdout and the second UART will be connected to a modem.
Note, that PPP is not available for all target boards. If this is the case the program will use the local Ethernet network, where DHCP must be available.
/*
 * Copyright (C) 2011 by egnite GmbH
 * Copyright (C) 2003-2006 by egnite Software GmbH
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * For additional information see http://www.ethernut.de/
 */

#include <cfg/ahdlc.h>

#include <dev/board.h>
#include <dev/ahdlcavr.h>
#include <dev/ppp.h>
#include <dev/chat.h>

#include <sys/version.h>
#include <sys/timer.h>

#include <arpa/inet.h>
#include <netdb.h>
#include <net/if_var.h>
#include <net/route.h>

#include <pro/dhcp.h>
#include <pro/sntp.h>
#include <pro/rfctime.h>

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <io.h>
#include <fcntl.h>
#include <time.h>

/*
 * Conversational script with a modem.
 *
 * The Nut/OS modem chat utility works similar to the the UNIX chat
 * script. In general it consists of one or more expect-send pairs of
 * strings or optional keyword-parameter pairs. Keywords are
 *
 * - TIMEOUT to set the max. time in seconds to wait for expected string
 * - ABORT to specify up to 10 abort strings
 * - REPORT to specify up to 3 reported abort strings
 *
 * Adjust this script to the requirements of your modem equipment
 * and your GPRS provider.
 *
 * The following script had been tested with a Siemens GPRS modem
 * (S55 mobile phone), using a t-mobile pre-paid account.
 */
#define PPP_CHAT    /* Wait up to 20 seconds for any response. */ \
                    "TIMEOUT 20" \
                    /* Expect nothing at the beginning. */ \
                    " ''" \
                    /* Send simple AT command to check the modem. */ \
                    " AT OK" \
                    /* Define PDP context, expecting 'OK'. */ \
                    " AT+CGDCONT=1,\"IP\",\"internet.t-mobile\" OK" \
                    /* Dial and wait for 'CONNECT'. */ \
                    " ATD*99***1# CONNECT"

/*
 * PPP user and password.
 *
 * Often GPRS providers accept any login.
 */
#define PPP_USER    "me"
#define PPP_PASS    "secret"

/*
 * PPP device settings.
 */
#if defined(NUT_THREAD_AHDLCRXSTACK)
#define PPP_DEV         devAhdlc1   /* AHDLC driver */
#define PPP_DEV_NAME    "uart1"     /* Physical device name */
#define PPP_SPEED       115200      /* Baudrate */
#define PPP_RXTO        1000        /* Receive timeout (ms) */
#else
#warning "PPP is not supported on your target"
#endif

/*
 * Open serial debug port for standard output.
 */
static void DebugPortOpen(void)
{
    uint32_t baud = 115200;

    /* Register debug UART. */
    NutRegisterDevice(&DEV_CONSOLE, 0, 0);
    /* Open debug device for standard output. */
    freopen(DEV_CONSOLE_NAME, "w", stdout);
    /* Set baud rate. */
    _ioctl(_fileno(stdout), UART_SETSPEED, &baud);
}

/*
 * Initialize the protocol port.
 */
static void ProtocolPortInit(void)
{
#ifdef PPP_DEV
    /* Register PPP and UART device. */
    NutRegisterDevice(&PPP_DEV, 0, 0);
    NutRegisterDevice(&devPpp, 0, 0);
#else
    /* Use Ethernet. */
    NutRegisterDevice(&DEV_ETHER, 0, 0);
#endif
}

/*
 * Open the physical device.
 */
static int ProtocolPortOpen(void)
{
#ifdef PPP_DEV
    int pppcom;
    uint32_t lctl;

    /* Open PPP device. Specify physical device, user and password. */
    printf("Open PPP interface at " PPP_DEV_NAME "...");
    pppcom = _open("ppp:" PPP_DEV_NAME "/" PPP_USER "/" PPP_PASS, _O_RDWR | _O_BINARY);
    if (pppcom == -1) {
        puts("failed");
        return -1;
    }

    /*
     * Set PPP line speed.
     */
    lctl = PPP_SPEED;
    _ioctl(pppcom, UART_SETSPEED, &lctl);
    printf("%lu baud", lctl);

    /*
     * The PPP driver doesn't set any receive timeout, but
     * may require it.
     */
    lctl = PPP_RXTO;
    _ioctl(pppcom, UART_SETREADTIMEOUT, &lctl);
    printf(", %lu ms timeout\n", lctl);

    return pppcom;
#else
    /* Nothing to be done for Ethernet. */
    return 0;
#endif
}

/*
 * Establish a modem connection.
 */
static int ProtocolPortConnect(int pppcom)
{
#ifdef PPP_DEV
    int rc;

    /*
     * Connect using a chat script. We may also set any
     * required hardware handshake line at this stage.
     */
    printf("Connecting...");
    for (;;) {
        rc = NutChat(pppcom, PPP_CHAT);
        switch (rc) {
        case 0:
            puts("done");
            /* A short pause is required here to let the driver
               initialize the receiver thread. */
            NutSleep(100);
            break;
        case 1:
            puts("bad script");
            break;
        case 2:
            puts("I/O error");
            break;
        case 3:
            puts("no response");
            break;
        default:
            printf("aborted (%d)\n", rc);
            break;
        }
        if (rc != 3) {
            break;
        }
        NutSleep(1000);
    }
    return rc;
#else
    /* Nothing to be done for Ethernet. */
    return 0;
#endif
}

/*
 * Hang up.
 */
static void ProtocolPortClose(int pppcom)
{
#ifdef PPP_DEV
    /* Set the UART back to normal mode. */
    _ioctl(pppcom, HDLC_SETIFNET, NULL);
    /* Close the physical port. This may or may not hang up. Please
       check the modem's documentation. */
    _close(pppcom);
#endif
}

static int ProtocolPortConfigure(void)
{
#ifdef PPP_DEV
    PPPDCB *dcb;

    /*
     * We are connected, configure our PPP network interface.
     * This will initiate the PPP configuration negotiation
     * and authentication with the server.
     */
    printf("Configure network interface...");
    if (NutNetIfConfig("ppp", 0, 0, 0)) {
        puts("failed");
        return -1;
    }
    puts("done");

    /*
     * Set name server and default route. Actually the PPP interface
     * should do this, but the current release doesn't.
     */
    dcb = devPpp.dev_dcb;
    NutDnsConfig2(0, 0, dcb->dcb_ip_dns1, dcb->dcb_ip_dns2);
    NutIpRouteAdd(0, 0, dcb->dcb_remote_ip, &devPpp);

    /*
     * Display our IP settings.
     */
    printf("     Local IP: %s\n", inet_ntoa(dcb->dcb_local_ip));
    printf("    Remote IP: %s\n", inet_ntoa(dcb->dcb_remote_ip));
    printf("  Primary DNS: %s\n", inet_ntoa(dcb->dcb_ip_dns1));
    printf("Secondary DNS: %s\n", inet_ntoa(dcb->dcb_ip_dns2));
#else
    /* We use DHCP on Ethernet. */
    printf("Configure network interface...");
    if (NutDhcpIfConfig(DEV_ETHER_NAME, 0, 60000)) {
        puts("failed");
        return -1;
    }
    puts("done");
#endif

    return 0;
}

/*
 * Connect any NTP-Pool server to query the current time.
 */
static void QueryDateAndTime(void)
{
    uint32_t ip;
    time_t now;
    int i;

    /* First connect the DNS server to get the IP address. */
    printf("Is There Anybody Out There? ");
    ip = NutDnsGetHostByName((uint8_t *) "pool.ntp.org");
    if (ip == 0) {
        puts("No?");
    } else {
        /* We do have an IP, now try to connect it. */
        printf("Yes, found %s\n", inet_ntoa(ip));
        for (i = 0; i < 3; i++) {
            printf("What's the time? ");
            if (NutSNTPGetTime(&ip, &now) == 0) {
                /* We got a valid response, display the result. */
                printf("%s GMT\n", Rfc1123TimeString(gmtime(&now)));
                return;
            } else {
                /* It failed. May be the server is too busy. Try
                   again in 5 seconds. */
                puts("Sorry?");
                NutSleep(5000);
            }
        }
    }
    /* We give up after 3 trials. */
    puts("You missed the starting gun.");
}

/*
 * PPP client application entry.
 */
int main(void)
{
    int pppcom;

    /* Initialize a debug port for standard output and display a banner. */
    DebugPortOpen();
    printf("\n\nPPP Client Sample - Nut/OS %s\n", NutVersionString());

    /* Initialize the network interface. */
    ProtocolPortInit();
    /* This loop runs once per hour. */
    for (;;) {
        /* Open the network interface. */
        pppcom = ProtocolPortOpen();
        if (pppcom == -1) {
            /* If this fails, we are busted. */
            break;
        }
        /* Establish the modem connection. */
        if (ProtocolPortConnect(pppcom) == 0) {
            /* Configure the network interface. */
            if (ProtocolPortConfigure() == 0) {
                /* Talk to the Internet. */
                QueryDateAndTime();
            }
        }
        /* Hang up. */
        ProtocolPortClose(pppcom);

        /* Sleep 1 hour. */
        puts("I'll be back in 1 hour.");
        NutSleep(3600000);
    }
    /* Ouch... */
    puts("Good bye cruel world");

    return 0;
}