/*      $OpenBSD: hayes.c,v 1.13 2006/03/17 19:17:13 moritz Exp $       */
/*      $NetBSD: hayes.c,v 1.6 1997/02/11 09:24:17 mrg Exp $    */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 */

/*
 * Routines for calling up on a Hayes Modem
 * (based on the old VenTel driver).
 * The modem is expected to be strapped for "echo".
 * Also, the switches enabling the DTR and CD lines
 * must be set correctly.
 * NOTICE:
 * The easy way to hang up a modem is always simply to
 * clear the DTR signal. However, if the +++ sequence
 * (which switches the modem back to local mode) is sent
 * before modem is hung up, removal of the DTR signal
 * has no effect (except that it prevents the modem from
 * recognizing commands).
 * (by Helge Skrivervik, Calma Company, Sunnyvale, CA. 1984) 
 */
/*
 * TODO:
 * It is probably not a good idea to switch the modem
 * state between 'verbose' and terse (status messages).
 * This should be kicked out and we should use verbose 
 * mode only. This would make it consistent with normal
 * interactive use thru the command 'tip dialer'.
 */
#include "tip.h"

#include <termios.h>
#include <sys/ioctl.h>

#define min(a,b)        ((a < b) ? a : b)

static  int dialtimeout = 0;
static  jmp_buf timeoutbuf;

#define DUMBUFLEN       40
static char dumbuf[DUMBUFLEN];

#define DIALING         1
#define IDLE            2
#define CONNECTED       3
#define FAILED          4
static  int state = IDLE;

static void     sigALRM(int);
static char     gobble(char *);
static void     error_rep(char);
static void     goodbye(void);
static int      hay_sync(void);

int
hay_dialer(char *num, char *acu)
{
        char *cp;
        int connected = 0;
        char dummy;
        struct termios cntrl;
#ifdef ACULOG
        char line[80];
#endif
        if (hay_sync() == 0)            /* make sure we can talk to the modem */
                return(0);
        if (boolean(value(VERBOSE)))
                printf("\ndialing...");
        fflush(stdout);
        tcgetattr(FD, &cntrl);
        cntrl.c_cflag |= HUPCL;
        tcsetattr(FD, TCSANOW, &cntrl);
        tcflush(FD, TCIOFLUSH);
        write(FD, "ATv0\r", 5); /* tell modem to use short status codes */
        gobble("\r");
        gobble("\r");
        write(FD, "ATTD", 4);   /* send dial command */
        for (cp = num; *cp; cp++)
                if (*cp == '=')
                        *cp = ',';
        write(FD, num, strlen(num));
        state = DIALING;
        write(FD, "\r", 1);
        connected = 0;
        if (gobble("\r")) {
                if ((dummy = gobble("01234")) != '1')
                        error_rep(dummy);
                else
                        connected = 1;
        }
        if (connected)
                state = CONNECTED;
        else {
                state = FAILED;
                return (connected);     /* lets get out of here.. */
        }
        tcflush(FD, TCIOFLUSH);
#ifdef ACULOG
        if (dialtimeout) {
                (void)snprintf(line, sizeof line, "%ld second dial timeout",
                        number(value(DIALTIMEOUT)));
                logent(value(HOST), num, "hayes", line);
        }
#endif
        if (dialtimeout)
                hay_disconnect();       /* insurance */
        return (connected);
}

void
hay_disconnect(void)
{
        /* first hang up the modem*/
#ifdef DEBUG
        printf("\rdisconnecting modem....\n\r");
#endif
        ioctl(FD, TIOCCDTR, 0);
        sleep(1);
        ioctl(FD, TIOCSDTR, 0);
        goodbye();
}

void
hay_abort(void)
{
        write(FD, "\r", 1);     /* send anything to abort the call */
        hay_disconnect();
}

/*ARGSUSED*/
static void
sigALRM(int signo)
{
        printf("\07timeout waiting for reply\n\r");
        dialtimeout = 1;
        longjmp(timeoutbuf, 1);
}

static char
gobble(char *match)
{
        char c;
        sig_t f;
        size_t i;
        int status = 0;

        f = signal(SIGALRM, sigALRM);
        dialtimeout = 0;
#ifdef DEBUG
        printf("\ngobble: waiting for %s\n", match);
#endif
        do {
                if (setjmp(timeoutbuf)) {
                        signal(SIGALRM, f);
                        return (0);
                }
                alarm(number(value(DIALTIMEOUT)));
                read(FD, &c, 1);
                alarm(0);
                c &= 0177;
#ifdef DEBUG
                printf("%c 0x%x ", c, c);
#endif
                for (i = 0; i < strlen(match); i++)
                        if (c == match[i])
                                status = c;
        } while (status == 0);
        signal(SIGALRM, SIG_DFL);
#ifdef DEBUG
        printf("\n");
#endif
        return (status);
}

static void
error_rep(char c)
{
        printf("\n\r");
        switch (c) {

        case '0':
                printf("OK");
                break;

        case '1':
                printf("CONNECT");
                break;

        case '2':
                printf("RING");
                break;

        case '3':
                printf("NO CARRIER");
                break;

        case '4':
                printf("ERROR in input");
                break;

        case '5':
                printf("CONNECT 1200");
                break;

        default:
                printf("Unknown Modem error: %c (0x%x)", c, c);
        }
        printf("\n\r");
        return;
}

/*
 * set modem back to normal verbose status codes.
 */
static void
goodbye(void)
{
        int len;
        char c;

        tcflush(FD, TCIOFLUSH);
        if (hay_sync()) {
                sleep(1);
#ifndef DEBUG
                tcflush(FD, TCIOFLUSH);
#endif
                write(FD, "ATH0\r", 5);         /* insurance */
#ifndef DEBUG
                c = gobble("03");
                if (c != '0' && c != '3') {
                        printf("cannot hang up modem\n\r");
                        printf("please use 'tip dialer' to make sure the line is hung up\n\r");
                }
#endif
                sleep(1);
                ioctl(FD, FIONREAD, &len);
#ifdef DEBUG
                printf("goodbye1: len=%d -- ", len);
                rlen = read(FD, dumbuf, min(len, DUMBUFLEN));
                dumbuf[rlen] = '\0';
                printf("read (%d): %s\r\n", rlen, dumbuf);
#endif
                write(FD, "ATv1\r", 5);
                sleep(1);
#ifdef DEBUG
                ioctl(FD, FIONREAD, &len);
                printf("goodbye2: len=%d -- ", len);
                rlen = read(FD, dumbuf, min(len, DUMBUFLEN));
                dumbuf[rlen] = '\0';
                printf("read (%d): %s\r\n", rlen, dumbuf);
#endif
        }
        tcflush(FD, TCIOFLUSH);
        ioctl(FD, TIOCCDTR, 0);         /* clear DTR (insurance) */
        close(FD);
}

#define MAXRETRY        5

static int
hay_sync(void)
{
        int len, retry = 0;

        while (retry++ <= MAXRETRY) {
                write(FD, "AT\r", 3);
                sleep(1);
                ioctl(FD, FIONREAD, &len);
                if (len) {
                        len = read(FD, dumbuf, min(len, DUMBUFLEN));
                        if (strchr(dumbuf, '0') || 
                        (strchr(dumbuf, 'O') && strchr(dumbuf, 'K')))
                                return(1);
#ifdef DEBUG
                        dumbuf[len] = '\0';
                        printf("hay_sync: (\"%s\") %d\n\r", dumbuf, retry);
#endif
                }
                ioctl(FD, TIOCCDTR, 0);
                ioctl(FD, TIOCSDTR, 0);
        }
        printf("Cannot synchronize with hayes...\n\r");
        return(0);
}