/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved. The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/signal.h>
#include <sys/systm.h>
#include <sys/termio.h>
#include <sys/ttold.h>
#include <sys/stropts.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/tty.h>
#include <sys/kmem.h>
#include <sys/errno.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/esunddi.h>

/*
 * The default (sane) set of termios values, unless
 * otherwise set by the user.
 */
static struct termios default_termios = {
        BRKINT|ICRNL|IXON|IMAXBEL,              /* c_iflag */
        OPOST|ONLCR|TAB3,                       /* c_oflag */
        B9600|CS8|CREAD,                        /* c_cflag */
        ISIG|ICANON|IEXTEN|ECHO|ECHOK|ECHOE|ECHOKE|ECHOCTL, /* c_lflag */
        {
                CINTR,
                CQUIT,
                CERASE,
                CKILL,
                CEOF,
                CEOL,
                CEOL2,
                CNSWTCH,
                CSTART,
                CSTOP,
                CSUSP,
                CDSUSP,
                CRPRNT,
                CFLUSH,
                CWERASE,
                CLNEXT,
                CSTATUS,
                CERASE2
        }
};


static int termioval(char **, uint_t *, char *);

void
ttycommon_close(tty_common_t *tc)
{
        mutex_enter(&tc->t_excl);
        tc->t_flags &= ~TS_XCLUDE;
        tc->t_readq = NULL;
        tc->t_writeq = NULL;
        if (tc->t_iocpending != NULL) {
                mblk_t *mp;

                mp = tc->t_iocpending;
                tc->t_iocpending = NULL;
                mutex_exit(&tc->t_excl);
                /*
                 * We were holding an "ioctl" response pending the
                 * availability of an "mblk" to hold data to be passed up;
                 * another "ioctl" came through, which means that "ioctl"
                 * must have timed out or been aborted.
                 */
                freemsg(mp);
        } else
                mutex_exit(&tc->t_excl);
}

/*
 * A "line discipline" module's queue is full.
 * Check whether IMAXBEL is set; if so, output a ^G, otherwise send an M_FLUSH
 * upstream flushing all the read queues.
 */
void
ttycommon_qfull(tty_common_t *tc, queue_t *q)
{
        mblk_t *mp;

        if (tc->t_iflag & IMAXBEL) {
                if (canput(WR(q))) {
                        if ((mp = allocb(1, BPRI_HI)) != NULL) {
                                *mp->b_wptr++ = CTRL('g');
                                (void) putq(WR(q), mp);
                        }
                }
        } else {
                flushq(q, FLUSHDATA);
                (void) putnextctl1(q, M_FLUSH, FLUSHR);
        }
}

/*
 * Process an "ioctl" message sent down to us, and return a reply message,
 * even if we don't understand the "ioctl".  Our client may want to use
 * that reply message for its own purposes if we don't understand it but
 * they do, and may want to modify it if we both understand it but they
 * understand it better than we do.
 * If the "ioctl" reply requires additional data to be passed up to the
 * caller, and we cannot allocate an mblk to hold the data, we return the
 * amount of data to be sent, so that our caller can do a "bufcall" and try
 * again later; otherwise, we return 0.
 */
size_t
ttycommon_ioctl(tty_common_t *tc, queue_t *q, mblk_t *mp, int *errorp)
{
        struct iocblk *iocp;
        size_t ioctlrespsize;
        mblk_t *tmp;

        *errorp = 0;    /* no error detected yet */

        iocp = (struct iocblk *)mp->b_rptr;

        if (iocp->ioc_count == TRANSPARENT) {
                *errorp = -1;   /* we don't understand it, maybe they do */
                return (0);
        }

        switch (iocp->ioc_cmd) {

        case TCSETSF:
                /*
                 * Flush the driver's queue, and send an M_FLUSH upstream
                 * to flush everybody above us.
                 */
                flushq(RD(q), FLUSHDATA);
                (void) putnextctl1(RD(q), M_FLUSH, FLUSHR);
                /* FALLTHROUGH */

        case TCSETSW:
        case TCSETS: {
                struct termios *cb;

                if (miocpullup(mp, sizeof (struct termios)) != 0) {
                        *errorp = -1;
                        break;
                }

                /*
                 * The only information we look at are the iflag word,
                 * the cflag word, and the start and stop characters.
                 */
                cb = (struct termios *)mp->b_cont->b_rptr;
                mutex_enter(&tc->t_excl);
                tc->t_iflag = cb->c_iflag;
                tc->t_cflag = cb->c_cflag;
                tc->t_stopc = cb->c_cc[VSTOP];
                tc->t_startc = cb->c_cc[VSTART];
                mutex_exit(&tc->t_excl);
                break;
        }

        case TCSETAF:
                /*
                 * Flush the driver's queue, and send an M_FLUSH upstream
                 * to flush everybody above us.
                 */
                flushq(RD(q), FLUSHDATA);
                (void) putnextctl1(RD(q), M_FLUSH, FLUSHR);
                /* FALLTHROUGH */

        case TCSETAW:
        case TCSETA: {
                struct termio *cb;

                if (miocpullup(mp, sizeof (struct termio)) != 0) {
                        *errorp = -1;
                        break;
                }

                /*
                 * The only information we look at are the iflag word
                 * and the cflag word.  Don't touch the unset portions.
                 */
                cb = (struct termio *)mp->b_cont->b_rptr;
                mutex_enter(&tc->t_excl);
                tc->t_iflag = (tc->t_iflag & 0xffff0000 | cb->c_iflag);
                tc->t_cflag = (tc->t_cflag & 0xffff0000 | cb->c_cflag);
                mutex_exit(&tc->t_excl);
                break;
        }

        case TIOCSWINSZ: {
                struct winsize *ws;

                if (miocpullup(mp, sizeof (struct winsize)) != 0) {
                        *errorp = -1;
                        break;
                }

                /*
                 * If the window size changed, send a SIGWINCH.
                 */
                ws = (struct winsize *)mp->b_cont->b_rptr;
                mutex_enter(&tc->t_excl);
                if (bcmp(&tc->t_size, ws, sizeof (struct winsize)) != 0) {
                        tc->t_size = *ws;
                        mutex_exit(&tc->t_excl);
                        (void) putnextctl1(RD(q), M_PCSIG, SIGWINCH);
                } else
                        mutex_exit(&tc->t_excl);
                break;
        }

        /*
         * Prevent more opens.
         */
        case TIOCEXCL:
                mutex_enter(&tc->t_excl);
                tc->t_flags |= TS_XCLUDE;
                mutex_exit(&tc->t_excl);
                break;

        /*
         * Permit more opens.
         */
        case TIOCNXCL:
                mutex_enter(&tc->t_excl);
                tc->t_flags &= ~TS_XCLUDE;
                mutex_exit(&tc->t_excl);
                break;

        /*
         * Set or clear the "soft carrier" flag.
         */
        case TIOCSSOFTCAR:
                if (miocpullup(mp, sizeof (int)) != 0) {
                        *errorp = -1;
                        break;
                }

                mutex_enter(&tc->t_excl);
                if (*(int *)mp->b_cont->b_rptr)
                        tc->t_flags |= TS_SOFTCAR;
                else
                        tc->t_flags &= ~TS_SOFTCAR;
                mutex_exit(&tc->t_excl);
                break;

        /*
         * The permission checking has already been done at the stream
         * head, since it has to be done in the context of the process
         * doing the call.
         */
        case TIOCSTI: {
                mblk_t *bp;

                if (miocpullup(mp, sizeof (char)) != 0) {
                        *errorp = -1;
                        break;
                }

                /*
                 * Simulate typing of a character at the terminal.
                 */
                if ((bp = allocb(1, BPRI_MED)) != NULL) {
                        if (!canput(tc->t_readq->q_next))
                                freemsg(bp);
                        else {
                                *bp->b_wptr++ = *mp->b_cont->b_rptr;
                                putnext(tc->t_readq, bp);
                        }
                }
                break;
        }
        }

        /*
         * Turn the ioctl message into an ioctl ACK message.
         */
        iocp->ioc_count = 0;    /* no data returned unless we say so */
        mp->b_datap->db_type = M_IOCACK;

        switch (iocp->ioc_cmd) {

        case TCSETSF:
        case TCSETSW:
        case TCSETS:
        case TCSETAF:
        case TCSETAW:
        case TCSETA:
        case TIOCSWINSZ:
        case TIOCEXCL:
        case TIOCNXCL:
        case TIOCSSOFTCAR:
        case TIOCSTI:
                /*
                 * We've done all the important work on these already;
                 * just reply with an ACK.
                 */
                break;

        case TCGETS: {
                struct termios *cb;
                mblk_t *datap;

                if ((datap = allocb(sizeof (struct termios),
                    BPRI_HI)) == NULL) {
                        ioctlrespsize = sizeof (struct termios);
                        goto allocfailure;
                }
                cb = (struct termios *)datap->b_wptr;
                /*
                 * The only information we supply is the cflag word.
                 * Our copy of the iflag word is just that, a copy.
                 */
                bzero(cb, sizeof (struct termios));
                cb->c_cflag = tc->t_cflag;
                datap->b_wptr += sizeof (struct termios);
                iocp->ioc_count = sizeof (struct termios);
                if (mp->b_cont != NULL)
                        freemsg(mp->b_cont);
                mp->b_cont = datap;
                break;
        }

        case TCGETA: {
                struct termio *cb;
                mblk_t *datap;

                if ((datap = allocb(sizeof (struct termio), BPRI_HI)) == NULL) {
                        ioctlrespsize = sizeof (struct termio);
                        goto allocfailure;
                }

                cb = (struct termio *)datap->b_wptr;
                /*
                 * The only information we supply is the cflag word.
                 * Our copy of the iflag word is just that, a copy.
                 */
                bzero(cb, sizeof (struct termio));
                cb->c_cflag = tc->t_cflag;
                datap->b_wptr += sizeof (struct termio);
                iocp->ioc_count = sizeof (struct termio);
                if (mp->b_cont != NULL)
                        freemsg(mp->b_cont);
                mp->b_cont = datap;
                break;
        }

        /*
         * Get the "soft carrier" flag.
         */
        case TIOCGSOFTCAR: {
                mblk_t *datap;

                if ((datap = allocb(sizeof (int), BPRI_HI)) == NULL) {
                        ioctlrespsize = sizeof (int);
                        goto allocfailure;
                }
                if (tc->t_flags & TS_SOFTCAR)
                        *(int *)datap->b_wptr = 1;
                else
                        *(int *)datap->b_wptr = 0;
                datap->b_wptr += sizeof (int);
                iocp->ioc_count = sizeof (int);
                if (mp->b_cont != NULL)
                        freemsg(mp->b_cont);
                mp->b_cont = datap;
                break;
        }

        case TIOCGWINSZ: {
                mblk_t *datap;

                if ((datap = allocb(sizeof (struct winsize),
                    BPRI_HI)) == NULL) {
                        ioctlrespsize = sizeof (struct winsize);
                        goto allocfailure;
                }
                /*
                 * Return the current size.
                 */
                *(struct winsize *)datap->b_wptr = tc->t_size;
                datap->b_wptr += sizeof (struct winsize);
                iocp->ioc_count = sizeof (struct winsize);
                if (mp->b_cont != NULL)
                        freemsg(mp->b_cont);
                mp->b_cont = datap;
                break;
        }

        default:
                *errorp = -1;   /* we don't understand it, maybe they do */
                break;
        }
        return (0);

allocfailure:

        mutex_enter(&tc->t_excl);
        tmp = tc->t_iocpending;
        tc->t_iocpending = mp;  /* hold this ioctl */
        mutex_exit(&tc->t_excl);
        /*
         * We needed to allocate something to handle this "ioctl", but
         * couldn't; save this "ioctl" and arrange to get called back when
         * it's more likely that we can get what we need.
         * If there's already one being saved, throw it out, since it
         * must have timed out.
         */
        if (tmp != NULL)
                freemsg(tmp);
        return (ioctlrespsize);
}

#define NFIELDS 22      /* 18 control characters + 4 sets of modes */

/*
 * Init routine run from main at boot time.
 * Creates a property in the "options" node that is
 * the default set of termios modes upon driver open.
 * If the property already existed, then it was
 * defined in the options.conf file.  In this case we
 * need to convert this string (stty -g style) to an
 * actual termios structure and store the new property
 * value.
 */

void
ttyinit()
{
        dev_info_t *dip;
        struct termios new_termios;
        struct termios *tp;
        char *property = "ttymodes";
        char **modesp, *cp;
        int i;
        uint_t val;
        uint_t len;


        /*
         * If the termios defaults were NOT set up by the
         * user via the options.conf file, create it using the
         * "sane" set of termios modes.
         * Note that if the property had been created via the
         * options.conf file, it would have been created as
         * a string property.  Since we would like to store
         * a structure (termios) in this property, we need
         * to change the property type to byte array.
         */
        if (ddi_prop_lookup_string_array(DDI_DEV_T_ANY, ddi_root_node(), 0,
            property, (char ***)&modesp, &len) != DDI_PROP_SUCCESS) {

                if ((dip = ddi_find_devinfo("options", -1, 0)) == NULL) {
                        cmn_err(CE_PANIC,
                            "ttyinit: Can't find options node!\n");
                }
                /*
                 * Create the property.
                 */
                if (ddi_prop_update_byte_array(DDI_DEV_T_NONE, dip,
                    property, (uchar_t *)&default_termios,
                    sizeof (struct termios)) != DDI_PROP_SUCCESS) {
                        cmn_err(CE_PANIC, "ttyinit: can't create %s property\n",
                            property);
                }
                return;
        }

        /*
         * This property was already set in the options.conf
         * file.  We must convert it from a "stty -g" string
         * to an actual termios structure.
         */
        bzero(&new_termios, sizeof (struct termios));
        tp = &new_termios;
        cp = *modesp;
        for (i = 0; i < NFIELDS; i++) {
                /*
                 * Check for bad field/string.
                 */
                if (termioval(&cp, &val, *modesp+strlen(*modesp)) == -1) {
                        cmn_err(CE_WARN,
                            "ttyinit: property '%s' %s\n", property,
                            "set incorrectly, using sane value");
                        tp = &default_termios;
                        break;
                }
                switch (i) {
                case 0:
                        new_termios.c_iflag = (tcflag_t)val;
                        break;
                case 1:
                        new_termios.c_oflag = (tcflag_t)val;
                        break;
                case 2:
                        new_termios.c_cflag = (tcflag_t)val;
                        break;
                case 3:
                        new_termios.c_lflag = (tcflag_t)val;
                        break;
                default:
                        new_termios.c_cc[i - 4] = (cc_t)val;
                }
        }
        if ((dip = ddi_find_devinfo("options", -1, 0)) == NULL) {
                cmn_err(CE_PANIC, "ttyinit: Can't find options node!\n");
        }

        /*
         * We need to create ttymode property as a byte array
         * since it will be interpreted as a termios struct.
         * The property was created as a string by default.
         * So remove the old property and add the new one -
         * otherwise we end up with two ttymodes properties.
         */
        if (e_ddi_prop_remove(DDI_DEV_T_NONE, dip, property)
            != DDI_PROP_SUCCESS) {
                cmn_err(CE_WARN, "ttyinit: cannot remove '%s' property\n",
                    property);
        }
        /*
         * Store the new defaults.  Since, this property was
         * autoconfig'ed, we must use e_ddi_prop_update_byte_array().
         */
        if (e_ddi_prop_update_byte_array(DDI_DEV_T_NONE, dip, property,
            (uchar_t *)tp, sizeof (struct termios)) != DDI_PROP_SUCCESS) {
                cmn_err(CE_PANIC, "ttyinit: cannot modify '%s' property\n",
                    property);
        }
        ddi_prop_free(modesp);
}

/*
 * Convert hex string representation of termios field
 * to a uint_t.  Increments string pointer to the next
 * field, and assigns value. Returns -1 if no more fields
 * or an error.
 */

static int
termioval(char **sp, uint_t *valp, char *ep)
{
        char *s = *sp;
        uint_t digit;

        if (s == 0)
                return (-1);
        *valp = 0;
        while (s < ep) {
                if (*s >= '0' && *s <= '9')
                        digit = *s++ - '0';
                else if (*s >= 'a' && *s <= 'f')
                        digit = *s++ - 'a' + 10;
                else if (*s >= 'A' && *s <= 'F')
                        digit = *s++ - 'A' + 10;
                else if (*s == ':' || *s == '\0')
                        break;
                else
                        return (-1);
                *valp = (*valp * 16) + digit;
        }
        /*
         * Null string or empty field.
         */
        if (s == *sp)
                return (-1);

        if (s < ep && *s == ':')
                s++;

        *sp = s;
        return (0);
}