CD Actual 3/CD ACTUAL 3.iso/linux/system/ringd-0.000/ringd-0/ringd/ringd.c

C/C++ Source or Header | 1995-02-02 | 4.4 KB | 255 lines

/*    ringd.c by Adam Dace <[e-mail]>
    Enjoy... */

#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include "config.h"

int tty_open(void);
int modem_reset(void);
int get_rings(int);
void shut_down(int);

int fd_modem, rings=0;
char buf[32];
time_t timer1;

int main(void)
{
        int got_rings;
        pid_t pid;

    if ((pid = fork()) < 0)
    {
        perror("Couldn't fork() daemon process");
        return(-1);
    }
    else
        if (pid != 0)
            exit(0);

    /* From here on out, it's daemon all the way... */

    setsid();
    chdir("/");
    umask(0);
    close(STDIN_FILENO);
    close(STDOUT_FILENO);
    close(STDERR_FILENO);

    if (signal(SIGTERM, shut_down) == SIG_ERR)
    {
        syslog(LOG_ERR,strerror(errno));
        shut_down(-1);
    }

    openlog("ringd", LOG_PID, LOG_DAEMON);
    syslog(LOG_NOTICE, "ringd 0.8 monitoring modem");

    while (1)
    {
        got_rings = 0;

        while (tty_open() < 0)
        {
            close (fd_modem);
            sleep (RECYCLE_TIME);
        }

        if (modem_reset() < 0)
            shut_down(-1);

        while (!got_rings)
        {
            timer1 = 0;
            time(&timer1);

            if (get_rings(3) < 0)
            {
                rings=1;
                continue;
            }
            else
                rings=0;

            if (get_rings(2) < 0)
            {
                rings=1;
                continue;
            }
            else
                rings=0;

            got_rings=1;
        }

        if (close(fd_modem) < 0)
        {
            syslog(LOG_ERR,strerror(errno));
            shut_down(-1);
        }

        sleep(2);

        if ((pid=fork()) < 0)    /* Be a man and fork, he says... */
        {            /* What utter crap and pain. */
            syslog(LOG_ERR,strerror(errno));
            shut_down(-1);
        }
        else
            if (pid == 0)
                    execl(PROGRAM,PROGRAM,ARG,NULL);
            else
                wait(NULL);

        sleep(2);
    }
}


int tty_open(void) /* Opens the modem, and sets terminal attributes. */
{
    struct termios term;

    if ((fd_modem = open("/dev/modem", O_RDWR | O_NOCTTY)) < 0)
    {
        syslog(LOG_ERR,strerror(errno));
        shut_down(-1);
    }

    if (isatty(fd_modem) == 0)
    {
        syslog(LOG_ERR,strerror(errno));
        shut_down(-1);
    }

    if (flock(fd_modem,LOCK_EX) < 0)
    {
        syslog(LOG_ERR,strerror(errno));
        shut_down(-1);
    }

    /* This right here is such a hack, even I have a hard time believing
     * it.  I stole these values from kermit and stty -a.  I tried a
     * number of other combinations, which didn't work, some help here
     * would be greatly appreciated. */

    term.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
    term.c_iflag = IGNBRK | IGNPAR;
    term.c_lflag = 0;
    term.c_oflag = 0;

    if (cfsetispeed(&term,BPS_RATE) < 0)
        return(-1);
    if (cfsetospeed(&term,BPS_RATE) < 0)
        return(-1);

    if (tcsetattr(fd_modem, TCSANOW, &term) < 0)
        return(-1);

    return(0);
}

int modem_reset(void) /* Resets the modem, and checks for additional rings. */
{
        char command[]=RESET_STR;         /* Modem reset. */
    int number;

        if (write(fd_modem, &command, 4) < 0)
    {
                syslog(LOG_ERR,strerror(errno));
                shut_down(-1);
    }

        sleep(RING_TIME);

        number=read(fd_modem, &buf, 32);
    buf[number]='\0';

        if (strstr(buf, OK) == NULL)
    {
                syslog(LOG_ERR,strerror(errno));
                shut_down(-1);
    }

        if (strstr(buf, RING) != NULL )
                return (1);

    return (0);
}

int get_rings(int rings_wanted) /* Waits for a number of specified rings. */
{
    int counter=0, done=0;
    time_t time1=0, time2=0;
    fd_set myset;

    FD_ZERO(&myset);

    while (!done)  /* BTW, read() is slightly broken, so select() we go */
    {
        FD_SET(fd_modem, &myset);
        select(2,&myset,NULL,&myset,NULL);

        counter = read(fd_modem, &buf, 256);
        buf[counter]='\0';

        if ((counter > 0) && (strstr(buf, RING) != NULL))
        {
                    time(&time1);

            if ((time2 == 0) && ((abs(difftime(timer1, time1)) < TOTAL_TIME)))
            {
                rings++;
                time2 = time1;
            }
            else
            {
                if (((abs(difftime(time1, time2))) < RING_TIME) &&
                    ((abs(difftime(timer1, time2))) < TOTAL_TIME))
                {
                    rings++;
                    time2 = time1;
                }
                else
                    return(-1);
            }
        }

        if (rings == rings_wanted)
        {
            if (modem_reset() == 0)
                done=1;
            else
                return(-1);
        }
    }

    return(0);
}

void shut_down(int status)    /* Shut down somewhat gracefully. */
{
    if (status != SIGTERM)
        syslog(LOG_NOTICE,"internal error occured, shutting down");
    else
        syslog(LOG_NOTICE,"SIGTERM recieved, shutting down");

    closelog();
    flock(fd_modem,LOCK_UN);
    close(fd_modem);
    exit(status);
}