/*      $NetBSD: courier.c,v 1.17 2006/12/14 17:09:43 christos Exp $    */

/*
 * Copyright (c) 1986, 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[] = "@(#)courier.c   8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: courier.c,v 1.17 2006/12/14 17:09:43 christos Exp $");
#endif /* not lint */

/*
 * Routines for calling up on a Courier modem.
 * Derived from Hayes driver.
 */
#include "tip.h"

#define MAXRETRY        5

static  int timeout = 0;
static  int connected = 0;
static  jmp_buf timeoutbuf;

static  int     cour_connect(void);
static  void    cour_nap(void);
static  void    cour_napx(int);
static  int     cour_swallow(const char *);
static  int     coursync(void);
#ifdef DEBUG
static  void    cour_verbose_read(void);
#endif
static  void    cour_write(int, const char *, int);
static  void    sigALRM(int);

int
cour_dialer(char *num, char *acu)
{
        char *cp;
        struct termios cntrl;

        if (boolean(value(VERBOSE)))
                (void)printf("Using \"%s\"\n", acu);

        (void)tcgetattr(FD, &cntrl);
        cntrl.c_cflag |= HUPCL;
        (void)tcsetattr(FD, TCSAFLUSH, &cntrl);
        /*
         * Get in synch.
         */
        if (!coursync()) {
badsynch:
                (void)printf("can't synchronize with courier\n");
                return (0);
        }
        cour_write(FD, "AT E0\r", 6);   /* turn off echoing */
        (void)sleep(1);
#ifdef DEBUG
        if (boolean(value(VERBOSE)))
                cour_verbose_read();
#endif
        (void)tcflush(FD, TCIOFLUSH);
        cour_write(FD, "AT C1 E0 H0 Q0 X6 V1\r", 21);
        if (!cour_swallow("\r\nOK\r\n"))
                goto badsynch;
        (void)fflush(stdout);
        cour_write(FD, "AT D", 4);
        for (cp = num; *cp; cp++)
                if (*cp == '=')
                        *cp = ',';
        cour_write(FD, num, (int)strlen(num));
        cour_write(FD, "\r", 1);
        connected = cour_connect();
        if (timeout)
                cour_disconnect();
        return (connected);
}

void
cour_disconnect(void)
{

        /* first hang up the modem*/
        (void)ioctl(FD, TIOCCDTR, 0);
        (void)sleep(1);
        (void)ioctl(FD, TIOCSDTR, 0);
        (void)coursync();                               /* reset */
        (void)close(FD);
}

void
cour_abort(void)
{

        cour_write(FD, "\r", 1);        /* send anything to abort the call */
        cour_disconnect();
}

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

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

static int
cour_swallow(const char * volatile match)
{
        sig_t f;
        char c;

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

struct baud_msg {
        const char *msg;
        unsigned int baud;
} baud_msg[] = {
        { "",           B300 },
        { " 1200",      B1200 },
        { " 2400",      B2400 },
        { " 9600",      B9600 },
        { " 9600/ARQ",  B9600 },
        { 0,            0 }
};

static int
cour_connect(void)
{
        char c;
        int volatile nc;
        int volatile nl;
        int n;
        char dialer_buf[64];
        struct baud_msg *bm;
        sig_t f;

        if (cour_swallow("\r\n") == 0)
                return (0);
        f = signal(SIGALRM, sigALRM);
again:
        (void)memset(dialer_buf, 0, sizeof(dialer_buf));
        timeout = 0;
        for (nc = 0, nl = sizeof(dialer_buf) - 1 ; nl > 0 ; nc++, nl--) {
                if (setjmp(timeoutbuf))
                        break;
                (void)alarm((unsigned)number(value(DIALTIMEOUT)));
                n = read(FD, &c, 1);
                (void)alarm(0);
                if (n <= 0)
                        break;
                c &= 0x7f;
                if (c == '\r') {
                        if (cour_swallow("\n") == 0)
                                break;
                        if (!dialer_buf[0])
                                goto again;
                        if (strcmp(dialer_buf, "RINGING") == 0 &&
                            boolean(value(VERBOSE))) {
#ifdef DEBUG
                                (void)printf("%s\r\n", dialer_buf);
#endif
                                goto again;
                        }
                        if (strncmp(dialer_buf, "CONNECT",
                                    sizeof("CONNECT")-1) != 0)
                                break;
                        for (bm = baud_msg ; bm->msg ; bm++)
                                if (strcmp(bm->msg,
                                    dialer_buf+sizeof("CONNECT")-1) == 0) {
                                        struct termios  cntrl;

                                        (void)tcgetattr(FD, &cntrl);
                                        (void)cfsetospeed(&cntrl, bm->baud);
                                        (void)cfsetispeed(&cntrl, bm->baud);
                                        (void)tcsetattr(FD, TCSAFLUSH, &cntrl);
                                        (void)signal(SIGALRM, f);
#ifdef DEBUG
                                        if (boolean(value(VERBOSE)))
                                                (void)printf("%s\r\n", dialer_buf);
#endif
                                        return (1);
                                }
                        break;
                }
                dialer_buf[nc] = c;
#ifdef notdef
                if (boolean(value(VERBOSE)))
                        (void)putchar(c);
#endif
        }
        (void)printf("%s\r\n", dialer_buf);
        (void)signal(SIGALRM, f);
        return (0);
}

/*
 * This convoluted piece of code attempts to get
 * the courier in sync.
 */
static int
coursync(void)
{
        int already = 0;
        int len;
        char buf[40];

        while (already++ < MAXRETRY) {
                (void)tcflush(FD, TCIOFLUSH);
                cour_write(FD, "\rAT Z\r", 6);  /* reset modem */
                (void)memset(buf, 0, sizeof(buf));
                (void)sleep(1);
                (void)ioctl(FD, FIONREAD, &len);
                if (len) {
                        len = read(FD, buf, sizeof(buf));
#ifdef DEBUG
                        buf[len] = '\0';
                        (void)printf("coursync: (\"%s\")\n\r", buf);
#endif
                        if (strchr(buf, '0') ||
                           (strchr(buf, 'O') && strchr(buf, 'K')))
                                return(1);
                }
                /*
                 * If not strapped for DTR control,
                 * try to get command mode.
                 */
                (void)sleep(1);
                cour_write(FD, "+++", 3);
                (void)sleep(1);
                /*
                 * Toggle DTR to force anyone off that might have left
                 * the modem connected.
                 */
                (void)ioctl(FD, TIOCCDTR, 0);
                (void)sleep(1);
                (void)ioctl(FD, TIOCSDTR, 0);
        }
        cour_write(FD, "\rAT Z\r", 6);
        return (0);
}

static void
cour_write(int fd, const char *cp, int n)
{

#ifdef notdef
        if (boolean(value(VERBOSE)))
                (void)write(1, cp, n);
#endif
        (void)tcdrain(fd);
        cour_nap();
        for ( ; n-- ; cp++) {
                (void)write(fd, cp, 1);
                (void)tcdrain(fd);
                cour_nap();
        }
}

#ifdef DEBUG
static void
cour_verbose_read(void)
{
        int n = 0;
        char buf[BUFSIZ];

        if (ioctl(FD, FIONREAD, &n) < 0)
                return;
        if (n <= 0)
                return;
        if (read(FD, buf, n) != n)
                return;
        (void)write(1, buf, n);
}
#endif

#define setsa(sa, a) \
        sa.sa_handler = a; (void)sigemptyset(&sa.sa_mask); sa.sa_flags = 0

static int napms = 50; /* Give the courier 50 milliseconds between characters */

static int ringring;

void
cour_nap(void)
{

        struct itimerval itv, oitv;
        struct itimerval *itp = &itv;
        struct sigaction sa, osa;
        sigset_t sm, osm;

        timerclear(&itp->it_interval);
        timerclear(&itp->it_value);
        if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
                return;

        (void)sigemptyset(&sm);
        (void)sigaddset(&sm, SIGALRM);
        (void)sigprocmask(SIG_BLOCK, &sm, &osm);

        itp->it_value.tv_sec = napms/1000;
        itp->it_value.tv_usec = ((napms%1000)*1000);

        setsa(sa, cour_napx);
        (void)sigaction(SIGALRM, &sa, &osa);

        (void)setitimer(ITIMER_REAL, itp, NULL);

        sm = osm;
        (void)sigdelset(&sm, SIGALRM);

        for (ringring = 0; !ringring; )
                (void)sigsuspend(&sm);

        (void)sigaction(SIGALRM, &osa, NULL);
        (void)setitimer(ITIMER_REAL, &oitv, NULL);
        (void)sigprocmask(SIG_SETMASK, &osm, NULL);
}

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

        ringring = 1;
}