/*      $NetBSD: ventel.c,v 1.17 2020/07/22 01:24:40 msaitoh Exp $      */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  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 University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)ventel.c    8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: ventel.c,v 1.17 2020/07/22 01:24:40 msaitoh Exp $");
#endif /* not lint */

/*
 * Routines for calling up on a Ventel Modem
 * The Ventel is expected to be strapped for local echo (just like uucp)
 */
#include "tip.h"

#define MAXRETRY        5

static  int timeout = 0;
static  jmp_buf timeoutbuf;

static  void    echo(const char *);
static  int     gobble(char, char *);
static  void    sigALRM(int);
static  int     vensync(int);

/*
 * some sleep calls have been replaced by usleep(DELAYUS)
 * because some ventel modems require two <cr>s in less than
 * a second in order to 'wake up'
 */
#define DELAYUS         100000          /* delay in microseconds */

int
/*ARGSUSED*/
ven_dialer(char *num, char *acu __unused)
{
        char *cp;
        int connected = 0;
        char *msg, line[80];
        struct termios  cntrl;

        /*
         * Get in synch with a couple of carriage returns
         */
        if (!vensync(FD)) {
                (void)printf("can't synchronize with ventel\n");
                return (0);
        }
        if (boolean(value(VERBOSE)))
                (void)printf("\ndialing...");
        (void)fflush(stdout);
        (void)tcgetattr(FD, &cntrl);
        cntrl.c_cflag |= HUPCL;
        (void)tcsetattr(FD, TCSANOW, &cntrl);
        echo("#k$\r$\n$D$I$A$L$:$ ");
        for (cp = num; *cp; cp++) {
                (void)usleep(DELAYUS);
                (void)write(FD, cp, 1);
        }
        (void)usleep(DELAYUS);
        (void)write(FD, "\r", 1);
        (void)gobble('\n', line);
        if (gobble('\n', line))
                connected = gobble('!', line);
        (void)tcflush(FD, TCIOFLUSH);
        if (timeout)
                ven_disconnect();       /* insurance */
        if (connected || timeout || !boolean(value(VERBOSE)))
                return (connected);
        /* call failed, parse response for user */
        cp = strchr(line, '\r');
        if (cp)
                *cp = '\0';
        for (cp = line; (cp = strchr(cp, ' ')) != NULL; cp++)
                if (cp[1] == ' ')
                        break;
        if (cp) {
                while (*cp == ' ')
                        cp++;
                msg = cp;
                while (*cp) {
                        if (isupper((unsigned char)*cp))
                                *cp = tolower((unsigned char)*cp);
                        cp++;
                }
                (void)printf("%s...", msg);
        }
        return (connected);
}

void
ven_disconnect(void)
{

        (void)close(FD);
}

void
ven_abort(void)
{

        (void)write(FD, "\03", 1);
        (void)close(FD);
}

static void
echo(const char *s)
{
        char c;

        while ((c = *s++) != 0) switch (c) {

        case '$':
                (void)read(FD, &c, 1);
                s++;
                break;

        case '#':
                c = *s++;
                (void)write(FD, &c, 1);
                break;

        default:
                (void)write(FD, &c, 1);
                (void)read(FD, &c, 1);
        }
}

static void
/*ARGSUSED*/
sigALRM(int dummy __unused)
{

        (void)printf("\07timeout waiting for reply\n");
        timeout = 1;
        longjmp(timeoutbuf, 1);
}

static int
gobble(char match, char response[])
{
        char * volatile cp;
        sig_t f;
        char c;

        cp = response;
        f = signal(SIGALRM, sigALRM);
        timeout = 0;
        do {
                if (setjmp(timeoutbuf)) {
                        (void)signal(SIGALRM, f);
                        *cp = '\0';
                        return (0);
                }
                (void)alarm((unsigned)number(value(DIALTIMEOUT)));
                (void)read(FD, cp, 1);
                (void)alarm(0);
                c = (*cp++ &= 0177);
#ifdef notdef
                if (boolean(value(VERBOSE)))
                        (void)putchar(c);
#endif
        } while (c != '\n' && c != match);
        (void)signal(SIGALRM, SIG_DFL);
        *cp = '\0';
        return (c == match);
}

#define min(a,b)        ((a)>(b)?(b):(a))
/*
 * This convoluted piece of code attempts to get
 * the ventel in sync.  If you don't have FIONREAD
 * there are gory ways to simulate this.
 */
static int
vensync(int fd)
{
        int already = 0, nread;
        char buf[60];

        /*
         * Toggle DTR to force anyone off that might have left
         * the modem connected, and insure a consistent state
         * to start from.
         *
         * If you don't have the ioctl calls to diddle directly
         * with DTR, you can always try setting the baud rate to 0.
         */
        (void)ioctl(FD, TIOCCDTR, 0);
        (void)sleep(1);
        (void)ioctl(FD, TIOCSDTR, 0);
        while (already < MAXRETRY) {
                /*
                 * After resetting the modem, send it two \r's to
                 * autobaud on. Make sure to delay between them
                 * so the modem can frame the incoming characters.
                 */
                (void)write(fd, "\r", 1);
                (void)usleep(DELAYUS);
                (void)write(fd, "\r", 1);
                (void)sleep(2);
                if (ioctl(fd, FIONREAD, &nread) < 0) {
                        perror("tip: ioctl");
                        continue;
                }
                while (nread > 0) {
                        (void)read(fd, buf, min(nread, sizeof buf));
                        if ((buf[min(nread, sizeof buf) - 1] & 0177) == '$')
                                return (1);
                        nread -= min(nread, 60);
                }
                (void)sleep(1);
                already++;
        }
        return (0);
}