/*      $OpenBSD: chat.c,v 1.39 2024/11/04 11:12:52 deraadt Exp $       */

/*
 *      Chat -- a program for automatic session establishment (i.e. dial
 *              the phone and log in).
 *
 * Standard termination codes:
 *  0 - successful completion of the script
 *  1 - invalid argument, expect string too large, etc.
 *  2 - error on an I/O operation or fatal error condition.
 *  3 - timeout waiting for a simple string.
 *  4 - the first string declared as "ABORT"
 *  5 - the second string declared as "ABORT"
 *  6 - ... and so on for successive ABORT strings.
 *
 *      This software is in the public domain.
 *
 * -----------------
 *      added -T and -U option and \T and \U substitution to pass a phone
 *      number into chat script. Two are needed for some ISDN TA applications.
 *      Keith Dart <kdart@cisco.com>
 *      
 *
 *      Added SAY keyword to send output to stderr.
 *      This allows to turn ECHO OFF and to output specific, user selected,
 *      text to give progress messages. This best works when stderr
 *      exists (i.e.: pppd in nodetach mode).
 *
 *      Added HANGUP directives to allow for us to be called
 *      back. When HANGUP is set to NO, chat will not hangup at HUP signal.
 *      We rely on timeouts in that case.
 *
 *      Added CLR_ABORT to clear previously set ABORT string. This has been
 *      dictated by the HANGUP above as "NO CARRIER" (for example) must be
 *      an ABORT condition until we know the other host is going to close
 *      the connection for call back. As soon as we have completed the
 *      first stage of the call back sequence, "NO CARRIER" is a valid, non
 *      fatal string. As soon as we got called back (probably get "CONNECT"),
 *      we should re-arm the ABORT "NO CARRIER". Hence the CLR_ABORT command.
 *      Note that CLR_ABORT packs the abort_strings[] array so that we do not
 *      have unused entries not being reclaimed.
 *
 *      In the same vein as above, added CLR_REPORT keyword.
 *
 *      Allow for comments. Line starting with '#' are comments and are
 *      ignored. If a '#' is to be expected as the first character, the 
 *      expect string must be quoted.
 *
 *
 *              Francis Demierre <Francis@SwissMail.Com>
 *              Thu May 15 17:15:40 MET DST 1997
 *
 *
 *      Added -r "report file" switch & REPORT keyword.
 *              Robert Geer <bgeer@xmission.com>
 *
 *      Added -s "use stderr" and -S "don't use syslog" switches.
 *              June 18, 1997
 *              Karl O. Pinc <kop@meme.com>
 *
 *
 *      Added -e "echo" switch & ECHO keyword
 *              Dick Streefland <dicks@tasking.nl>
 *
 *
 *      Considerable updates and modifications by
 *              Al Longyear <longyear@pobox.com>
 *              Paul Mackerras <paulus@cs.anu.edu.au>
 *
 *
 *      The original author is:
 *
 *              Karl Fox <karl@MorningStar.Com>
 *              Morning Star Technologies, Inc.
 *              1760 Zollinger Road
 *              Columbus, OH  43221
 *              (614)451-1883
 *
 *
 */

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

#ifndef TERMIO
#undef  TERMIOS
#define TERMIOS
#endif

#ifdef TERMIO
#include <termio.h>
#endif
#ifdef TERMIOS
#include <termios.h>
#endif

#define STR_LEN 1024

#ifndef SIGTYPE
#define SIGTYPE void
#endif

#ifndef O_NONBLOCK
#define O_NONBLOCK      O_NDELAY
#endif

#ifdef SUNOS
extern int sys_nerr;
extern char *sys_errlist[];
#define memmove(to, from, n)    bcopy(from, to, n)
#define strerror(n)             ((unsigned)(n) < sys_nerr? sys_errlist[(n)] :\
                                 "unknown error")
#endif

#define MAX_ABORTS              50
#define MAX_REPORTS             50
#define DEFAULT_CHAT_TIMEOUT    45

int echo          = 0;
int verbose       = 0;
int to_log        = 1;
int to_stderr     = 0;
int Verbose       = 0;
int quiet         = 0;
int report        = 0;
int exit_code     = 0;
FILE* report_fp   = (FILE *) 0;
char *report_file = (char *) 0;
char *chat_file   = (char *) 0;
char *phone_num   = (char *) 0;
char *phone_num2  = (char *) 0;
int timeout       = DEFAULT_CHAT_TIMEOUT;

int have_tty_parameters = 0;

extern char *__progname;

#ifdef TERMIO
#define term_parms struct termio
#define get_term_param(param) ioctl(0, TCGETA, param)
#define set_term_param(param) ioctl(0, TCSETA, param)
struct termio saved_tty_parameters;
#endif

#ifdef TERMIOS
#define term_parms struct termios
#define get_term_param(param) tcgetattr(0, param)
#define set_term_param(param) tcsetattr(0, TCSANOW, param)
struct termios saved_tty_parameters;
#endif

char *abort_string[MAX_ABORTS], *fail_reason = NULL,
        fail_buffer[50];
int n_aborts = 0, abort_next = 0, timeout_next = 0, echo_next = 0;
int clear_abort_next = 0;

char *report_string[MAX_REPORTS] ;
char  report_buffer[50] ;
int n_reports = 0, report_next = 0, report_gathering = 0 ; 
int clear_report_next = 0;

int say_next = 0, hup_next = 0;

void usage(void);
void logmsg(const char *fmt, ...);
void fatal(int code, const char *fmt, ...);
SIGTYPE sigalrm(int signo);
SIGTYPE sigint(int signo);
SIGTYPE sigterm(int signo);
SIGTYPE sighup(int signo);
void unalarm(void);
void init(void);
void set_tty_parameters(void);
void echo_stderr(int);
void break_sequence(void);
void terminate(int status);
void do_file(char *chat_file);
int  get_string(char *string);
int  put_string(char *s);
int  write_char(int c);
int  put_char(int c);
int  get_char(void);
void chat_send(char *s);
char *character(int c);
void chat_expect(char *s);
char *clean(char *s, int sending);
void break_sequence(void);
void terminate(int status);
void pack_array(char **array, int end);
char *expect_strtok(char *, char *);
int vfmtmsg(char *, int, const char *, va_list);        /* vsnprintf++ */

int main(int, char *[]);

/*
 * chat [ -v ] [-T number] [-U number] [ -t timeout ] [ -f chat-file ] \
 * [ -r report-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)
{
    const char *errstr;
    int option;

    tzset();

    while ((option = getopt(argc, argv, "esSvVt:r:f:T:U:")) != -1) {
        switch (option) {
        case 'e':
            echo = 1;
            break;

        case 'v':
            verbose = 1;
            break;

        case 'V':
            Verbose = 1;
            break;

        case 's':
            to_stderr = 1;
            break;

        case 'S':
            to_log = 0;
            break;

        case 'f':
            if ((chat_file = strdup(optarg)) == NULL)
                fatal(2, "memory error!");
            break;

        case 't':
            timeout = strtonum(optarg, 0, 10000, &errstr);
            if (errstr)
                fatal(2, "-t %s: %s\n", optarg, errstr);
            break;

        case 'r':
            if (report_fp != NULL)
                fclose (report_fp);
            if ((report_file = strdup(optarg)) == NULL)
                fatal(2, "memory error!");
            report_fp   = fopen (report_file, "a");
            if (report_fp != NULL) {
                if (verbose)
                    fprintf (report_fp, "Opening \"%s\"...\n",
                             report_file);
                report = 1;
            }
            break;

        case 'T':
            if ((phone_num = strdup(optarg)) == NULL)
                fatal(2, "memory error!");
            break;

        case 'U':
            phone_num2 = strdup(optarg);
            if ((phone_num2 = strdup(optarg)) == NULL)
                fatal(2, "memory error!");
            break;

        case ':':
            fprintf(stderr, "Option -%c requires an argument\n",
                optopt);

        default:
            usage();
            break;
        }
    }
    argc -= optind;
    argv += optind;
/*
 * Default the report file to the stderr location
 */
    if (report_fp == NULL)
        report_fp = stderr;

    if (to_log) {
#ifdef ultrix
        openlog("chat", LOG_PID);
#else
        openlog("chat", LOG_PID | LOG_NDELAY, LOG_LOCAL2);

        if (verbose)
            setlogmask(LOG_UPTO(LOG_INFO));
        else
            setlogmask(LOG_UPTO(LOG_WARNING));
#endif
    }

    init();
    
    if (chat_file != NULL) {
        if (argc > 0)
            usage();
        else
            do_file (chat_file);
    } else {
        while (argc-- > 0) {
            chat_expect(*argv++);

            if (argc-- > 0) {
                chat_send(*argv++);
            }
        }
    }

    terminate(0);
    return 0;
}

/*
 *  Process a chat script when read from a file.
 */

void
do_file(char *chat_file)
{
    int linect, sendflg;
    char *sp, *arg, quote;
    char buf [STR_LEN];
    FILE *cfp;

    cfp = fopen (chat_file, "r");
    if (cfp == NULL)
        fatal(1, "%s -- open failed: %m", chat_file);

    linect = 0;
    sendflg = 0;

    while (fgets(buf, STR_LEN, cfp) != NULL) {
        buf[strcspn(buf, "\n")] = '\0';

        linect++;
        sp = buf;

        /* lines starting with '#' are comments. If a real '#'
           is to be expected, it should be quoted .... */
        if ( *sp == '#' )
            continue;

        while (*sp != '\0') {
            if (*sp == ' ' || *sp == '\t') {
                ++sp;
                continue;
            }

            if (*sp == '"' || *sp == '\'') {
                quote = *sp++;
                arg = sp;
                while (*sp != quote) {
                    if (*sp == '\0')
                        fatal(1, "unterminated quote (line %d)", linect);

                    if (*sp++ == '\\') {
                        if (*sp != '\0')
                            ++sp;
                    }
                }
            }
            else {
                arg = sp;
                while (*sp != '\0' && *sp != ' ' && *sp != '\t')
                    ++sp;
            }

            if (*sp != '\0')
                *sp++ = '\0';

            if (sendflg)
                chat_send (arg);
            else
                chat_expect (arg);
            sendflg = !sendflg;
        }
    }
    fclose (cfp);
}

/*
 *      We got an error parsing the command line.
 */
void usage(void)
{
    fprintf(stderr, "\
usage: %s [-eSsVv] [-f chat_file] [-r report_file] [-T phone_number]\n\
            [-t timeout] [-U phone_number_2] script\n",
     __progname);
    exit(1);
}

char line[1024];

/*
 * Send a message to syslog and/or stderr.
 */
void logmsg(const char *fmt, ...)
{
    va_list args;

    va_start(args, fmt);
    vfmtmsg(line, sizeof(line), fmt, args);
    va_end(args);
    if (to_log)
        syslog(LOG_INFO, "%s", line);
    if (to_stderr)
        fprintf(stderr, "%s\n", line);
}

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

void fatal(int code, const char *fmt, ...)
{
    va_list args;

    va_start(args, fmt);
    vfmtmsg(line, sizeof(line), fmt, args);
    va_end(args);
    if (to_log)
        syslog(LOG_ERR, "%s", line);
    if (to_stderr)
        fprintf(stderr, "%s\n", line);
    terminate(code);
}

int alarmed = 0;

SIGTYPE sigalrm(int signo)
{
    int flags;

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

    if ((flags = fcntl(0, F_GETFL)) == -1)
        fatal(2, "Can't get file mode flags on stdin: %m");

    if (fcntl(0, F_SETFL, flags | O_NONBLOCK) == -1)
        fatal(2, "Can't set file mode flags on stdin: %m");

    if (verbose)
        logmsg("alarm");
}

void unalarm(void)
{
    int flags;

    if ((flags = fcntl(0, F_GETFL)) == -1)
        fatal(2, "Can't get file mode flags on stdin: %m");

    if (fcntl(0, F_SETFL, flags & ~O_NONBLOCK) == -1)
        fatal(2, "Can't set file mode flags on stdin: %m");
}

SIGTYPE sigint(int signo)
{
    fatal(2, "SIGINT");
}

SIGTYPE sigterm(int signo)
{
    fatal(2, "SIGTERM");
}

SIGTYPE sighup(int signo)
{
    fatal(2, "SIGHUP");
}

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

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

void set_tty_parameters(void)
{
#if defined(get_term_param)
    term_parms t;

    if (get_term_param (&t) < 0)
        fatal(2, "Can't get terminal parameters: %m");

    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 (set_term_param (&t) < 0)
        fatal(2, "Can't set terminal parameters: %m");
#endif
}

void break_sequence(void)
{
#ifdef TERMIOS
    tcsendbreak (0, 0);
#endif
}

void terminate(int status)
{
    echo_stderr(-1);
    if (report_file != (char *) 0 && report_fp != (FILE *) NULL) {
/*
 * Allow the last of the report string to be gathered before we terminate.
 */
        if (report_gathering) {
            int c, rep_len;

            rep_len = strlen(report_buffer);
            while (rep_len + 1 <= sizeof(report_buffer)) {
                alarm(1);
                c = get_char();
                alarm(0);
                if (c < 0 || iscntrl(c))
                    break;
                report_buffer[rep_len] = c;
                ++rep_len;
            }
            report_buffer[rep_len] = 0;
            fprintf (report_fp, "chat:  %s\n", report_buffer);
        }
        if (verbose)
            fprintf (report_fp, "Closing \"%s\".\n", report_file);
        fclose (report_fp);
        report_fp = (FILE *) NULL;
    }

#if defined(get_term_param)
    if (have_tty_parameters) {
        if (set_term_param (&saved_tty_parameters) < 0)
            fatal(2, "Can't restore terminal parameters: %m");
    }
#endif

    exit(status);
}

/*
 *      'Clean up' this string.
 */
char *clean(char *s, int sending)
{
    char *ret, *t, cur_chr;
    int new_length;
    char *s1, *phchar;
    int add_return = sending;
#define isoctal(chr) (((chr) >= '0') && ((chr) <= '7'))

    /* Overestimate new length: */
    new_length = 0;
    for (t = s; *t; t++)
        if (*t == '^' && *(t+1) != '\0') {
            t++;
            new_length++;
        } else if (*t != '\\') {
            new_length++;
        } else {
            t++;
            switch (*t) {
            case 'c':
            case 'b':
            case 'r':
            case 'n':
            case 's':
            case 't':
                new_length++;
                break;
            case 'K':
            case 'p':
            case 'd':
            case '\0':
            case '\\':
            case 'N':
                new_length += 2;
                break;
            case 'T':
                new_length += sending && phone_num ? strlen(phone_num) : 2;
                break;
            case 'U':
                new_length += sending && phone_num2 ? strlen(phone_num2) : 2;
                break;
            default:
                if (isoctal(*t)) {
                    t++;
                    if (isoctal(*t)) {
                        t++;
                        if (isoctal(*t)) 
                            t++;
                    }
                }
                t--;
                new_length += 2;        /* Could become \\ */
            }
            if (*t == '\0')
                break;
        }

    new_length += 3;    /* \r and two nuls */

    ret = malloc(new_length);
    if (ret == NULL)
            fatal(2, "cannot allocate memory");

    s1 = ret;
    while (*s) {
        cur_chr = *s++;
        if (cur_chr == '^') {
            cur_chr = *s++;
            if (cur_chr == '\0') {
                *s1++ = '^';
                break;
            }
            cur_chr &= 0x1F;
            if (cur_chr != 0) {
                *s1++ = cur_chr;
            }
            continue;
        }

        if (cur_chr != '\\') {
            *s1++ = cur_chr;
            continue;
        }

        cur_chr = *s++;
        if (cur_chr == '\0') {
            if (sending) {
                *s1++ = '\\';
                *s1++ = '\\';
            }
            break;
        }

        switch (cur_chr) {
        case 'b':
            *s1++ = '\b';
            break;

        case 'c':
            if (sending && *s == '\0')
                add_return = 0;
            else
                *s1++ = cur_chr;
            break;

        case '\\':
        case 'K':
        case 'p':
        case 'd':
            if (sending)
                *s1++ = '\\';

            *s1++ = cur_chr;
            break;

        case 'T':
            if (sending && phone_num) {
                for ( phchar = phone_num; *phchar != '\0'; phchar++) 
                    *s1++ = *phchar;
            }
            else {
                *s1++ = '\\';
                *s1++ = 'T';
            }
            break;

        case 'U':
            if (sending && phone_num2) {
                for ( phchar = phone_num2; *phchar != '\0'; phchar++) 
                    *s1++ = *phchar;
            }
            else {
                *s1++ = '\\';
                *s1++ = 'U';
            }
            break;

        case 'q':
            quiet = 1;
            break;

        case 'r':
            *s1++ = '\r';
            break;

        case 'n':
            *s1++ = '\n';
            break;

        case 's':
            *s1++ = ' ';
            break;

        case 't':
            *s1++ = '\t';
            break;

        case 'N':
            if (sending) {
                *s1++ = '\\';
                *s1++ = '\0';
            }
            else
                *s1++ = 'N';
            break;
            
        default:
            if (isoctal (cur_chr)) {
                cur_chr &= 0x07;
                if (isoctal (*s)) {
                    cur_chr <<= 3;
                    cur_chr |= *s++ - '0';
                    if (isoctal (*s)) {
                        cur_chr <<= 3;
                        cur_chr |= *s++ - '0';
                    }
                }

                if (cur_chr != 0 || sending) {
                    if (sending && (cur_chr == '\\' || cur_chr == 0))
                        *s1++ = '\\';
                    *s1++ = cur_chr;
                }
                break;
            }

            if (sending)
                *s1++ = '\\';
            *s1++ = cur_chr;
            break;
        }
    }

    if (add_return)
        *s1++ = '\r';

    *s1++ = '\0'; /* guarantee closure */
    *s1++ = '\0'; /* terminate the string */

#ifdef DEBUG
    fprintf(stderr, "clean(): guessed %d and used %d\n", new_length, s1-ret);
#endif
    if (new_length < s1 - ret)
        logmsg("clean(): new_length too short! %d < %d: \"%s\" -> \"%s\"", 
               new_length, s1 - ret, s, ret);

    return ret;
}

/*
 * A modified version of 'strtok'. This version skips \ sequences.
 */

char *expect_strtok (char *s, char *term)
{
    static  char *str   = "";
    int     escape_flag = 0;
    char   *result;

/*
 * If a string was specified then do initial processing.
 */
    if (s)
        str = s;

/*
 * If this is the escape flag then reset it and ignore the character.
 */
    if (*str)
        result = str;
    else
        result = (char *) 0;

    while (*str) {
        if (escape_flag) {
            escape_flag = 0;
            ++str;
            continue;
        }

        if (*str == '\\') {
            ++str;
            escape_flag = 1;
            continue;
        }

/*
 * If this is not in the termination string, continue.
 */
        if (strchr (term, *str) == (char *) 0) {
            ++str;
            continue;
        }

/*
 * This is the terminator. Mark the end of the string and stop.
 */
        *str++ = '\0';
        break;
    }
    return (result);
}

/*
 * Process the expect string
 */

void chat_expect (char *s)
{
    char *expect;
    char *reply;

    if (strcmp(s, "HANGUP") == 0) {
        ++hup_next;
        return;
    }
 
    if (strcmp(s, "ABORT") == 0) {
        ++abort_next;
        return;
    }

    if (strcmp(s, "CLR_ABORT") == 0) {
        ++clear_abort_next;
        return;
    }

    if (strcmp(s, "REPORT") == 0) {
        ++report_next;
        return;
    }

    if (strcmp(s, "CLR_REPORT") == 0) {
        ++clear_report_next;
        return;
    }

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

    if (strcmp(s, "ECHO") == 0) {
        ++echo_next;
        return;
    }

    if (strcmp(s, "SAY") == 0) {
        ++say_next;
        return;
    }

/*
 * Fetch the expect and reply string.
 */
    for (;;) {
        expect = expect_strtok (s, "-");
        s      = (char *) 0;

        if (expect == (char *) 0)
            return;

        reply = expect_strtok (s, "-");

/*
 * Handle the expect string. If successful then exit.
 */
        if (get_string (expect))
            return;

/*
 * If there is a sub-reply string then send it. Otherwise any condition
 * is terminal.
 */
        if (reply == (char *) 0 || exit_code != 3)
            break;

        chat_send (reply);
    }

/*
 * The expectation did not occur. This is terminal.
 */
    if (fail_reason)
        logmsg("Failed (%s)", fail_reason);
    else
        logmsg("Failed");
    terminate(exit_code);
}

/*
 * Translate the input character to the appropriate string for printing
 * the data.
 */

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

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

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

    return (string);
}

/*
 *  process the reply string
 */
void chat_send (char *s)
{
    const char *errstr;

    if (say_next) {
        say_next = 0;
        s = clean(s,0);
        write(STDERR_FILENO, s, strlen(s));
        free(s);
        return;
    }

    if (hup_next) {
        hup_next = 0;
        if (strcmp(s, "OFF") == 0)
           signal(SIGHUP, SIG_IGN);
        else
           signal(SIGHUP, sighup);
        return;
    }

    if (echo_next) {
        echo_next = 0;
        echo = (strcmp(s, "ON") == 0);
        return;
    }

    if (abort_next) {
        char *s1;
        
        abort_next = 0;
        
        if (n_aborts >= MAX_ABORTS)
            fatal(2, "Too many ABORT strings");
        
        s1 = clean(s, 0);
        
        if (strlen(s1) > strlen(s)
            || strlen(s1) + 1 > sizeof(fail_buffer))
            fatal(1, "Illegal or too-long ABORT string ('%v')", s);

        abort_string[n_aborts++] = s1;

        if (verbose)
            logmsg("abort on (%v)", s);
        return;
    }

    if (clear_abort_next) {
        char *s1;
        int   i;
        int   old_max;
        int   pack = 0;
        
        clear_abort_next = 0;
        
        s1 = clean(s, 0);
        
        if (strlen(s1) > strlen(s)
            || strlen(s1) + 1 > sizeof(fail_buffer))
            fatal(1, "Illegal or too-long CLR_ABORT string ('%v')", s);

        old_max = n_aborts;
        for (i=0; i < n_aborts; i++) {
            if ( strcmp(s1,abort_string[i]) == 0 ) {
                free(abort_string[i]);
                abort_string[i] = NULL;
                pack++;
                n_aborts--;
                if (verbose)
                    logmsg("clear abort on (%v)", s);
            }
        }
        free(s1);
        if (pack)
            pack_array(abort_string,old_max);
        return;
    }

    if (report_next) {
        char *s1;
        
        report_next = 0;
        if (n_reports >= MAX_REPORTS)
            fatal(2, "Too many REPORT strings");
        
        s1 = clean(s, 0);
        
        if (strlen(s1) > strlen(s) || strlen(s1) > sizeof fail_buffer - 1)
            fatal(1, "Illegal or too-long REPORT string ('%v')", s);
        
        report_string[n_reports++] = s1;
        
        if (verbose)
            logmsg("report (%v)", s);
        return;
    }

    if (clear_report_next) {
        char *s1;
        int   i;
        int   old_max;
        int   pack = 0;
        
        clear_report_next = 0;
        
        s1 = clean(s, 0);
        
        if (strlen(s1) > strlen(s) || strlen(s1) > sizeof fail_buffer - 1)
            fatal(1, "Illegal or too-long REPORT string ('%v')", s);

        old_max = n_reports;
        for (i=0; i < n_reports; i++) {
            if ( strcmp(s1,report_string[i]) == 0 ) {
                free(report_string[i]);
                report_string[i] = NULL;
                pack++;
                n_reports--;
                if (verbose)
                    logmsg("clear report (%v)", s);
            }
        }
        free(s1);
        if (pack)
            pack_array(report_string,old_max);
        
        return;
    }

    if (timeout_next) {
        timeout_next = 0;
        timeout = strtonum(s, -1, 10000, &errstr);
        if (errstr) {
            logmsg("invalid timeout %s: %s\n", s, errstr);
            timeout = -1;
        } 
        if (timeout <= 0)
            timeout = DEFAULT_CHAT_TIMEOUT;

        if (verbose)
            logmsg("timeout set to %d seconds", timeout);

        return;
    }

    if (strcmp(s, "EOT") == 0)
        s = "^D\\c";
    else if (strcmp(s, "BREAK") == 0)
        s = "\\K\\c";

    if (!put_string(s))
        fatal(1, "Failed");
}

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

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

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

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

    case -1:
        if ((status = fcntl(0, F_GETFL)) == -1)
            fatal(2, "Can't get file mode flags on stdin: %m");

        if (fcntl(0, F_SETFL, status & ~O_NONBLOCK) == -1)
            fatal(2, "Can't set file mode flags on stdin: %m");
        
        return (-1);
    }
}

int put_char(int c)
{
    int status;
    char ch = c;

    usleep(10000);              /* inter-character typing delay (?) */

    status = write(STDOUT_FILENO, &ch, 1);

    switch (status) {
    case 1:
        return (0);
        
    default:
        logmsg("warning: write() on stdout returned %d", status);
        
    case -1:
        if ((status = fcntl(0, F_GETFL)) == -1)
            fatal(2, "Can't get file mode flags on stdin, %m");

        if (fcntl(0, F_SETFL, status & ~O_NONBLOCK) == -1)
            fatal(2, "Can't set file mode flags on stdin: %m");
        
        return (-1);
    }
}

int write_char (int c)
{
    if (alarmed || put_char(c) < 0) {
        alarm(0);
        alarmed = 0;

        if (verbose) {
            if (errno == EINTR || errno == EWOULDBLOCK)
                logmsg(" -- write timed out");
            else
                logmsg(" -- write failed: %m");
        }
        return (0);
    }
    return (1);
}

int put_string (char *s)
{
    quiet = 0;
    s = clean(s, 1);

    if (verbose) {
        if (quiet)
            logmsg("send (hidden)");
        else
            logmsg("send (%v)", s);
    }

    alarm(timeout); alarmed = 0;

    while (*s) {
        char c = *s++;

        if (c != '\\') {
            if (!write_char (c))
                return 0;
            continue;
        }

        c = *s++;
        switch (c) {
        case 'd':
            sleep(1);
            break;

        case 'K':
            break_sequence();
            break;

        case 'p':
            usleep(10000);      /* 1/100th of a second (arg is microseconds) */
            break;

        default:
            if (!write_char (c))
                return 0;
            break;
        }
    }

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

/*
 *      Echo a character to stderr.
 *      When called with -1, a '\n' character is generated when
 *      the cursor is not at the beginning of a line.
 */
void echo_stderr(int n)
{
    static int need_lf;
    char *s;

    switch (n) {
    case '\r':          /* ignore '\r' */
        break;
    case -1:
        if (need_lf == 0)
            break;
        /* fall through */
    case '\n':
        write(STDERR_FILENO, "\n", 1);
        need_lf = 0;
        break;
    default:
        s = character(n);
        write(STDERR_FILENO, s, strlen(s));
        need_lf = 1;
        break;
    }
}

/*
 *      'Wait for' this string to appear on this file descriptor.
 */
int get_string(char *string)
{
    char temp[STR_LEN];
    int c, printed = 0, len, minlen;
    char *s = temp, *end = s + STR_LEN;
    char *logged = temp;

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

    if (verbose)
        logmsg("expect (%v)", string);

    if (len > STR_LEN) {
        logmsg("expect string is too long");
        exit_code = 1;
        return 0;
    }

    if (len == 0) {
        if (verbose)
            logmsg("got it");
        return (1);
    }

    alarm(timeout);
    alarmed = 0;

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

        if (echo)
            echo_stderr(c);
        if (verbose && c == '\n') {
            if (s == logged)
                logmsg("");     /* blank line */
            else
                logmsg("%0.*v", s - logged, logged);
            logged = s + 1;
        }

        *s++ = c;

        if (verbose && s >= logged + 80) {
            logmsg("%0.*v", s - logged, logged);
            logged = s;
        }

        if (Verbose) {
           if (c == '\n')
               fputc( '\n', stderr );
           else if (c != '\r')
               fprintf( stderr, "%s", character(c) );
        }

        if (!report_gathering) {
            for (n = 0; n < n_reports; ++n) {
                if ((report_string[n] != (char*) NULL) &&
                    s - temp >= (report_len = strlen(report_string[n])) &&
                    strncmp(s - report_len, report_string[n], report_len) == 0) {
                    time_t time_now   = time (NULL);
                    struct tm* tm_now = localtime (&time_now);

                    strftime (report_buffer, 20, "%b %d %H:%M:%S ", tm_now);
                    strlcat (report_buffer, report_string[n], sizeof(report_buffer));

                    report_string[n] = (char *) NULL;
                    report_gathering = 1;
                    break;
                }
            }
        }
        else {
            if (!iscntrl (c)) {
                int rep_len = strlen (report_buffer);
                report_buffer[rep_len]     = c;
                report_buffer[rep_len + 1] = '\0';
            }
            else {
                report_gathering = 0;
                fprintf (report_fp, "chat:  %s\n", report_buffer);
            }
        }

        if (s - temp >= len &&
            c == string[len - 1] &&
            strncmp(s - len, string, len) == 0) {
            if (verbose) {
                if (s > logged)
                    logmsg("%0.*v", s - logged, logged);
                logmsg(" -- 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) {
                    if (s > logged)
                        logmsg("%0.*v", s - logged, logged);
                    logmsg(" -- failed");
                }

                alarm(0);
                alarmed = 0;
                exit_code = n + 4;
                strlcpy(fail_buffer, abort_string[n], sizeof fail_buffer);
                fail_reason = fail_buffer;
                return (0);
            }
        }

        if (s >= end) {
            if (logged < s - minlen) {
                logmsg("%0.*v", s - logged, logged);
                logged = s;
            }
            s -= minlen;
            memmove(temp, s, minlen);
            logged = temp + (logged - s);
            s = temp + minlen;
        }

        if (alarmed && verbose)
            logmsg("warning: alarm synchronization problem");
    }

    alarm(0);
    
    if (verbose && printed) {
        if (alarmed)
            logmsg(" -- read timed out");
        else
            logmsg(" -- read failed: %m");
    }

    exit_code = 3;
    alarmed   = 0;
    return (0);
}

void
pack_array (char **array, int end)
{
    int i, j;

    for (i = 0; i < end; i++) {
        if (array[i] == NULL) {
            for (j = i+1; j < end; ++j)
                if (array[j] != NULL)
                    array[i++] = array[j];
            for (; i < end; ++i)
                array[i] = NULL;
            break;
        }
    }
}

/*
 * vfmtmsg - format a message into a buffer.  Like vsnprintf except we
 * also specify the length of the output buffer, and we handle the
 * %m (error message) format.
 * Doesn't do floating-point formats.
 * Returns the number of chars put into buf.
 */
#define OUTCHAR(c)      (buflen > 0? (--buflen, *buf++ = (c)): 0)

int
vfmtmsg(char *buf, int buflen, const char *fmt, va_list args)
{
    int c, i, n;
    int width, prec, fillch;
    int base, len, neg, quoted;
    unsigned long val = 0;
    char *str, *buf0;
    const char *f;
    unsigned char *p;
    char num[32];
    static char hexchars[] = "0123456789abcdef";

    buf0 = buf;
    --buflen;
    while (buflen > 0) {
        for (f = fmt; *f != '%' && *f != 0; ++f)
            ;
        if (f > fmt) {
            len = f - fmt;
            if (len > buflen)
                len = buflen;
            memcpy(buf, fmt, len);
            buf += len;
            buflen -= len;
            fmt = f;
        }
        if (*fmt == 0)
            break;
        c = *++fmt;
        width = prec = 0;
        fillch = ' ';
        if (c == '0') {
            fillch = '0';
            c = *++fmt;
        }
        if (c == '*') {
            width = va_arg(args, int);
            c = *++fmt;
        } else {
            while (isdigit(c)) {
                width = width * 10 + c - '0';
                c = *++fmt;
            }
        }
        if (c == '.') {
            c = *++fmt;
            if (c == '*') {
                prec = va_arg(args, int);
                c = *++fmt;
            } else {
                while (isdigit(c)) {
                    prec = prec * 10 + c - '0';
                    c = *++fmt;
                }
            }
        }
        str = 0;
        base = 0;
        neg = 0;
        ++fmt;
        switch (c) {
        case 'd':
            i = va_arg(args, int);
            if (i < 0) {
                neg = 1;
                val = -i;
            } else
                val = i;
            base = 10;
            break;
        case 'o':
            val = va_arg(args, unsigned int);
            base = 8;
            break;
        case 'x':
            val = va_arg(args, unsigned int);
            base = 16;
            break;
        case 'p':
            val = (unsigned long) va_arg(args, void *);
            base = 16;
            neg = 2;
            break;
        case 's':
            str = va_arg(args, char *);
            break;
        case 'c':
            num[0] = va_arg(args, int);
            num[1] = 0;
            str = num;
            break;
        case 'm':
            str = strerror(errno);
            break;
        case 'v':               /* "visible" string */
        case 'q':               /* quoted string */
            quoted = c == 'q';
            p = va_arg(args, unsigned char *);
            if (fillch == '0' && prec > 0) {
                n = prec;
            } else {
                n = strlen((char *)p);
                if (prec > 0 && prec < n)
                    n = prec;
            }
            while (n > 0 && buflen > 0) {
                c = *p++;
                --n;
                if (!quoted && c >= 0x80) {
                    OUTCHAR('M');
                    OUTCHAR('-');
                    c -= 0x80;
                }
                if (quoted && (c == '"' || c == '\\'))
                    OUTCHAR('\\');
                if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
                    if (quoted) {
                        OUTCHAR('\\');
                        switch (c) {
                        case '\t':      OUTCHAR('t');   break;
                        case '\n':      OUTCHAR('n');   break;
                        case '\b':      OUTCHAR('b');   break;
                        case '\f':      OUTCHAR('f');   break;
                        default:
                            OUTCHAR('x');
                            OUTCHAR(hexchars[c >> 4]);
                            OUTCHAR(hexchars[c & 0xf]);
                        }
                    } else {
                        if (c == '\t')
                            OUTCHAR(c);
                        else {
                            OUTCHAR('^');
                            OUTCHAR(c ^ 0x40);
                        }
                    }
                } else
                    OUTCHAR(c);
            }
            continue;
        default:
            *buf++ = '%';
            if (c != '%')
                --fmt;          /* so %z outputs %z etc. */
            --buflen;
            continue;
        }
        if (base != 0) {
            str = num + sizeof(num);
            *--str = 0;
            while (str > num + neg) {
                *--str = hexchars[val % base];
                val = val / base;
                if (--prec <= 0 && val == 0)
                    break;
            }
            switch (neg) {
            case 1:
                *--str = '-';
                break;
            case 2:
                *--str = 'x';
                *--str = '0';
                break;
            }
            len = num + sizeof(num) - 1 - str;
        } else {
            len = strlen(str);
            if (prec > 0 && len > prec)
                len = prec;
        }
        if (width > 0) {
            if (width > buflen)
                width = buflen;
            if ((n = width - len) > 0) {
                buflen -= n;
                for (; n > 0; --n)
                    *buf++ = fillch;
            }
        }
        if (len > buflen)
            len = buflen;
        memcpy(buf, str, len);
        buf += len;
        buflen -= len;
    }
    *buf = 0;
    return buf - buf0;
}