/*
 *	Chat -- a program for automatic session establishment (i.e. dial
 *		the phone and log in).
 *
 *	This software is in the public domain.
 *
 *	Please send all bug reports, requests for information, etc. to:
 *
 *		Karl Fox <karl@MorningStar.Com>
 *		Morning Star Technologies, Inc.
 *		1760 Zollinger Road
 *		Columbus, OH  43221
 *		(614)451-1883
 */

/*static char sccs_id[] = "@(#)chat.c	1.7";*/
static char rcsid[] = "$Id: chat.c,v 1.4 1993/11/09 04:57:19 paulus Exp $";

#include <fcntl.h>
#include <stdio.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <stdarg.h>
#include <syslog.h>
#include <termios.h>
#include <string.h>
#include <stdlib.h>

#define TERMIOS

#define	STR_LEN	1024

#ifndef SIGTYPE
#define SIGTYPE __sighandler_endif
#endif

/*************** Micro getopt() *********************************************/
#define	OPTION(c,v)	(_O&2&&**v?*(*v)++:!c||_O&4?0:(!(_O&1)&& \
				(--c,++v),_O=4,c&&**v=='-'&&v[0][1]?*++*v=='-'\
				&&!v[0][1]?(--c,++v,0):(_O=2,*(*v)++):0))
#define	OPTARG(c,v)	(_O&2?**v||(++v,--c)?(_O=1,--c,*v++): \
				(_O=4,(char*)0):(char*)0)
#define	OPTONLYARG(c,v)	(_O&2&&**v?(_O=1,--c,*v++):(char*)0)
#define	ARG(c,v)	(c?(--c,*v++):(char*)0)

static int _O = 0;		/* Internal state */
/*************** Micro getopt() *********************************************/

char *program_name;

#define	copyof(s)	((s) ? strcpy(malloc(strlen(s) + 1), s) : (s))

#ifndef LOCK_DIR
#define	LOCK_DIR	"/usr/spool/uucp"
#endif /* LOCK_DIR */

#define	MAX_ABORTS		50
#define	DEFAULT_CHAT_TIMEOUT	45

int verbose             = 0;
int quiet               = 0;
char *lock_file         = (char *)0;
int timeout             = DEFAULT_CHAT_TIMEOUT;
int have_tty_parameters = 0;
int n_aborts            = 0,
    abort_next          = 0,
    timeout_next        = 0;

struct termios saved_tty_parameters;

char *abort_string[MAX_ABORTS],
     *fail_reason = (char *)0,
     fail_buffer[50];

int main (int argc, char **argv);
void usage (void);
void logfv (const char *fmt, va_list pvar);
void logf (const char *fmt, ...);
void warn (const char *format, ...);
void fatal (const char *format, ...);
void sysfatal (const char *format, ...);
void unalarm (void);
void sigalrm (int signo);
void sigint (int signo);
void sigterm (int signo);
void sighup (int signo);
void init (void);
void set_tty_parameters (void);
void terminate (int status);
void lock (void);
void unlock (void);
char *clean (register char *s, int sending);
void chat_expect (register char *s);
char *character (char c);
int chat_send (register char *s);
int get_char (void);
int put_char (char c);
int put_string (register char *s);
int get_string (register char *string);
void delay (void);

/*
 *	chat [ -v ] [ -t timeout ] [ -l lock-file ] \
 *		[...[[expect[-say[-expect...]] say expect[-say[-expect]] ...]]]
 *
 *	Perform a UUCP-dialer-like chat script on stdin and stdout.
 */

int main (int argc, char **argv)
    {
    int option, n;
    char *arg;

    program_name = *argv;

    while (option = OPTION(argc, argv))
        {
        switch (option)
	    {
	case 'v':
	    ++verbose;
	    break;

	case 'l':
	    if (arg = OPTARG(argc, argv))
	        {
	        lock_file = copyof(arg);
	        }
	    else
	        {
	        usage();
	        }	    
	    break;

	case 't':
	    if (arg = OPTARG(argc, argv))
	        {
		timeout = atoi(arg);
	        }
	    else
	        {
		usage();
	        }
	    break;

	default:
	    usage();
	    break;
	    }
        }

    openlog("chat", LOG_PID | LOG_NDELAY, LOG_LOCAL2);

    if (verbose)
        {
	setlogmask(LOG_UPTO(LOG_INFO));
        }
    else
        {
	setlogmask(LOG_UPTO(LOG_WARNING));
        }

    init();
    
    while (arg = ARG(argc, argv))
	{
	chat_expect(arg);
	if (arg = ARG(argc, argv))
	    {
	    chat_send(arg);
	    }
	}

    terminate(0);
    return (0);
    }

/*
 *	We got an error parsing the command line.
 */

void usage (void)
    {
    fprintf(stderr,
	    "Usage: %s [ -v ] [ -l lock-file ] [ -t timeout ] chat-script\n",
	    program_name);
    exit(1);
    }

char line[256];
char *p;

void logfv (const char *fmt, va_list pvar)
    {
    char buf[256];

    vsprintf (buf, fmt, pvar);
    p = line + strlen(line);
    strcat (p, buf);

    if (buf[strlen(buf)-1] == '\n')
        {
	syslog (LOG_INFO, "%s", line);
	line[0] = 0;
        }
    }

void logf (const char *fmt, ...)
    {
    va_list pvar;

    va_start (pvar, fmt);
    logfv    (fmt, pvar);
    va_end   (pvar);
    }

/*
 *	Print a warning message.
 */

void warn (const char *format, ...)
    {
    va_list pvar;

    va_start (pvar, format);
    logf     ("%s: Warning: ", program_name);
    logfv    (format, pvar);
    logf     ("\n");
    va_end   (pvar);
    }

/*
 *	Print an error message and terminate.
 */

void fatal (const char *format, ...)
    {
    va_list pvar;

    va_start (pvar, format);
    logf     ("%s: ", program_name);
    logfv    (format, pvar);
    logf     ("\n");
    va_end   (pvar);

    unlock();
    terminate(1);
    }

/*
 *	Print an error message along with the system error message and
 *	terminate.
 */

void sysfatal (const char *format, ...)
    {
    char message[STR_LEN];
    va_list  pvar;

    sprintf  (message, "%s: ", program_name);
    va_start (pvar, format);
    vsprintf (message + strlen(message), format, pvar);
    va_end   (pvar);
    perror   (message);
    unlock();
    terminate(1);
    }

int alarmed = 0;

void sigint (int signo)
    {
    fatal("SIGINT");
    }

void sigterm (int signo)
    {
    fatal("SIGTERM");
    }

void sighup (int signo)
    {
    fatal("SIGHUP");
    }

void sigalrm (int signo)
    {
    int flags;

    alarm(1); alarmed = 1;	/* Reset alarm to avoid race window */
    signal(SIGALRM, sigalrm);	/* that can cause hanging in read() */

    flags = fcntl(0, F_GETFL, 0);
    if (flags == -1)
        {
	sysfatal ("Can't get file mode flags on stdin");
        }
    else
        {
	if (fcntl (0, F_SETFL, flags | O_NDELAY) == -1)
	    {
	    sysfatal ("Can't set file mode flags on stdin");
	    }
        }
    
    if (verbose)
	{
	logf ("alarm\n");
	}
    }

void unalarm (void)
    {
    int flags;

    flags = fcntl(0, F_GETFL, 0);

    if (flags == -1)
        {
	sysfatal ("Can't get file mode flags on stdin");
        }

    if (fcntl(0, F_SETFL, flags & ~O_NDELAY) == -1)
        {
	sysfatal ("Can't set file mode flags on stdin");
        }
    }

void init (void)
    {
    signal(SIGINT,  sigint);
    signal(SIGTERM, sigterm);
    signal(SIGHUP,  sighup);

    if (lock_file)
        {
	lock();
        }

    set_tty_parameters();
    signal(SIGALRM, sigalrm);
    alarm (0);
    alarmed = 0;
    }

void set_tty_parameters (void)
    {
    struct termios t;

    if (tcgetattr(0, &t) < 0)
        {
	sysfatal("Can't get terminal parameters");
        }

    saved_tty_parameters = t;
    have_tty_parameters = 1;

    t.c_iflag      = IGNBRK | ISTRIP | IGNPAR;
    t.c_oflag      = 0;
    t.c_lflag      = 0;
    t.c_cc[VERASE] = t.c_cc[VKILL] = 0;
    t.c_cc[VMIN]   = 1;
    t.c_cc[VTIME]  = 0;

    if (tcsetattr(0, TCSANOW, &t) < 0)
        {
	sysfatal("Can't set terminal parameters");
        }
    }

void terminate (int status)
    {
    if (have_tty_parameters)
	{
	if (tcsetattr(0, TCSANOW, &saved_tty_parameters) < 0)
	    {
	    perror ("Can't restore terminal parameters");
	    unlock();
	    status = 1;
	    }
	}
    exit (status);
    }

/*
 *	Create a lock file for the named lock device
 */

void lock (void)
    {
    char hdb_lock_buffer[12];
    int fd, pid;

    lock_file = strcat(strcat(strcpy(malloc(strlen(LOCK_DIR)
				       + 1 + strlen(lock_file) + 1),
				LOCK_DIR), "/"), lock_file);

    if ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0)
	{
	char *s = lock_file;

	lock_file = (char *)0;	/* Don't remove someone else's lock file! */
	sysfatal("Can't get lock file '%s'", s);
	}

    sprintf(hdb_lock_buffer, "%10d\n", getpid());
    write(fd, hdb_lock_buffer, 11);
    close(fd);
    }

/*
 *	Remove our lockfile
 */

void unlock (void)
    {
    if (lock_file)
	{
	unlink(lock_file);
	lock_file = (char *)0;
	}
    }

/*
 *	'Clean up' this string.
 */

char *clean (register char *s, int sending)
    {
    char temp[STR_LEN];
    register char *s1;
    int add_return = sending;

    for (s1 = temp; *s; ++s)
	 switch (*s)
	     {
	     case '\\':
		 switch (*++s)
		     {
		     case '\\':
		     case 'd':	if (sending)
				    *s1++ = '\\';

				*s1++ = *s;
				break;

		     case 'q':	quiet = ! quiet; break;
		     case 'r':	*s1++ = '\r'; break;
		     case 'n':	*s1++ = '\n'; break;
		     case 's':	*s1++ = ' '; break;

		     case 'c':	if (sending && s[1] == '\0')
				    add_return = 0;
				else
				    *s1++ = *s;

				break;

		     default:	*s1++ = *s;
		     }

		 break;

	     case '^':
		 *s1++ = (int)(*++s) & 0x1F;
		 break;

	     default:
		 *s1++ = *s;
	     }
    
    if (add_return)
	*s1++ = '\r';

    *s1 = '\0';
    return (copyof(temp));
    }

/*
 *
 */

void chat_expect (register char *s)
    {
    if (strcmp(s, "ABORT") == 0)
	{
	++abort_next;
	return;
	}

    if (strcmp(s, "TIMEOUT") == 0)
	{
	++timeout_next;
	return;
	}

    while (*s)
	{
	register char *hyphen;

	for (hyphen = s; *hyphen; ++hyphen)
	    if (*hyphen == '-')
		if (hyphen == s || hyphen[-1] != '\\')
		    break;
	
	if (*hyphen == '-')
	    {
	    *hyphen = '\0';

	    if (get_string(s))
		return;
	    else
		{
		s = hyphen + 1;

		for (hyphen = s; *hyphen; ++hyphen)
		    if (*hyphen == '-')
			if (hyphen == s || hyphen[-1] != '\\')
			    break;

		if (*hyphen == '-')
		    {
		    *hyphen = '\0';

		    chat_send(s);
		    s = hyphen + 1;
		    }
		else
		    {
		    chat_send(s);
		    return;
		    }
		}
	    }
	else
	    if (get_string(s))
		return;
	    else
		{
		if (fail_reason)
		    logf("Failed(%s)\n", fail_reason);
		else
		    logf("Failed\n");

		unlock();
		terminate(1);
		}
	}
    }

char *character (char c)
    {
    static char string[10];
    char *meta;

    meta = (c & 0x80) ? "M-" : "";
    c &= 0x7F;

    if (c < 32)
	sprintf(string, "%s^%c", meta, (int)c + '@');
    else
	if (c == 127)
	    sprintf(string, "%s^?", meta);
	else
	    sprintf(string, "%s%c", meta, c);

    return (string);
    }

/*
 *
 */

int chat_send (register char *s)
    {
    if (abort_next)
	{
	char *s1;

	abort_next = 0;

	if (n_aborts >= MAX_ABORTS)
	    fatal("Too many ABORT strings");

	s1 = clean(s, 0);

	if (strlen(s1) > strlen(s))
	    fatal("Illegal ABORT string ('%s')\n", s);

	if (strlen(s1) > sizeof fail_buffer - 1)
	    fatal("Too long ABORT string ('%s')\n", s);

	strcpy(s, s1);
	abort_string[n_aborts++] = s;

	if (verbose)
	    {
	    register char *s1 = s;

	    logf("abort on (");

	    for (s1 = s; *s1; ++s1)
		logf("%s", character(*s1));

	    logf(")\n");
	    }
	}
    else
	if (timeout_next)
	    {
	    timeout_next = 0;
	    timeout = atoi(s);

	    if (timeout <= 0)
		timeout = DEFAULT_CHAT_TIMEOUT;

	    if (verbose)
		{
		logf("timeout set to %d seconds\n", timeout);
		}
	    }
	else
	    if ( ! put_string(s))
		{
		logf("Failed\n");
		unlock();
		terminate(1);
		}
    }

int get_char (void)
    {
    int status;
    char c;

    status = read(0, &c, 1);

    switch (status)
	{
	case 1:
	    return ((int)c & 0x7F);

	default:
	    warn("read() on stdin returned %d", status);

	case -1:
	    if ((status = fcntl(0, F_GETFL, 0)) == -1)
		sysfatal("Can't get file mode flags on stdin");
	    else
		if (fcntl(0, F_SETFL, status & ~O_NDELAY) == -1)
		    sysfatal("Can't set file mode flags on stdin");

	    return (-1);
	}
    }

int put_char (char c)
    {
    int status;

    delay();

    status = write(1, &c, 1);

    switch (status)
	{
	case 1:
	    return (0);

	default:
	    warn("write() on stdout returned %d", status);

	case -1:
	    if ((status = fcntl(0, F_GETFL, 0)) == -1)
		sysfatal("Can't get file mode flags on stdin");
	    else
		if (fcntl(0, F_SETFL, status & ~O_NDELAY) == -1)
		    sysfatal("Can't set file mode flags on stdin");

	    return (-1);
	}
    }

int put_string (register char *s)
    {
    s = clean(s, 1);

    if (verbose)
	{
	logf("send (");

	if (quiet)
	    logf("??????");
	else
	    {
	    register char *s1 = s;

	    for (s1 = s; *s1; ++s1)
		logf("%s", character(*s1));
	    }

	logf(")\n");
	}

    alarm(timeout); alarmed = 0;

    for ( ; *s; ++s)
	{
	register char c = *s;

	if (c == '\\')
	    if ((c = *++s) == '\0')
		break;
	    else
		if (c == 'd')		/* \d -- Delay */
		    {
		    sleep(2);
		    continue;
		    }

	if (alarmed || put_char(*s) < 0)
	    {
	    extern int errno;

	    alarm(0); alarmed = 0;

	    if (verbose)
		{
		if (errno == EINTR || errno == EWOULDBLOCK)
		    logf(" -- write timed out\n");
		else
		    syslog(LOG_INFO, " -- write failed: %m");
		}

	    return (0);
	    }
	}

    alarm(0); alarmed = 0;
    return (1);
    }

/*
 *	'Wait for' this string to appear on this file descriptor.
 */

int get_string (register char *string)
    {
    char temp[STR_LEN];
    int c, printed = 0, len, minlen;
    register char *s = temp, *end = s + STR_LEN;

    fail_reason = (char *)0;
    string = clean(string, 0);
    len = strlen(string);
    minlen = (len > sizeof(fail_buffer)? len: sizeof(fail_buffer)) - 1;

    if (verbose)
	{
	register char *s1;

	logf("expect (");

	for (s1 = string; *s1; ++s1)
	    logf("%s", character(*s1));

	logf(")\n");
	}

    if (len > STR_LEN)
	{
	logf("expect string is too long\n");
	return;
	}

    if (len == 0)
	{
	if (verbose)
	    {
	    logf("got it\n");
	    }

	return (1);
	}

    alarm(timeout); alarmed = 0;

    while ( ! alarmed && (c = get_char()) >= 0)
	{
	int n, abort_len;

	if (verbose)
	    {
	    if (c == '\n')
		logf("\n");
	    else
		logf("%s", character(c));
	    }

	*s++ = c;

	if (s - temp >= len &&
	    c == string[len - 1] &&
	    strncmp(s - len, string, len) == 0)
	    {
	    if (verbose)
		{
		logf("got it\n");
		}

	    alarm(0); alarmed = 0;
	    return (1);
	    }

	for (n = 0; n < n_aborts; ++n)
	    if (s - temp >= (abort_len = strlen(abort_string[n])) &&
		strncmp(s - abort_len, abort_string[n], abort_len) == 0)
		{
		if (verbose)
		    {
		    logf(" -- failed\n");
		    }

		alarm(0); alarmed = 0;
		strcpy(fail_reason = fail_buffer, abort_string[n]);
		return (0);
		}

	if (s >= end)
	    {
	    strncpy(temp, s - minlen, minlen);
	    s = temp + minlen;
	    }

	if (alarmed && verbose)
	    warn("Alarm synchronization problem");
	}

    alarm(0);
    
    if (verbose && printed)
	{
	extern int errno;

	if (alarmed)
	    logf(" -- read timed out\n");
	else
	    syslog(LOG_INFO, " -- read failed: %m");
	}

    alarmed = 0;
    return (0);
    }
/*
 *	Delay an amount appropriate for between typed characters.
 */

void delay (void)
    {
    struct   timeval   tm_delay;
    fd_set   fd_read, fd_write, fd_except;
/*
 *  Make the delay for 100 usec
 */
    timerclear (&tm_delay);
    tm_delay.tv_usec = 100;

    FD_ZERO (&fd_read);
    FD_ZERO (&fd_write);
    FD_ZERO (&fd_except);
/*
 *  Simply wait for the time limit to expire.
 */
    (void) select (1,                   /* width                      */
		   &fd_read,            /* Pointer to the read list   */
		   &fd_write,           /* Pointer to the write list  */
		   &fd_except,          /* Pointer to the except list */
		   &tm_delay);          /* Time delay value           */
    }