/* $Id: isdn_common.c,v 1.1.2.3 2004/02/10 01:07:13 keil Exp $
 *
 * Linux ISDN subsystem, common used functions (linklevel).
 *
 * Copyright 1994-1999  by Fritz Elfert (fritz@isdn4linux.de)
 * Copyright 1995,96    Thinking Objects Software GmbH Wuerzburg
 * Copyright 1995,96    by Michael Hipp (Michael.Hipp@student.uni-tuebingen.de)
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/isdn.h>
#include <linux/mutex.h>
#include "isdn_common.h"
#include "isdn_tty.h"
#include "isdn_net.h"
#include "isdn_ppp.h"
#ifdef CONFIG_ISDN_AUDIO
#include "isdn_audio.h"
#endif
#ifdef CONFIG_ISDN_DIVERSION_MODULE
#define CONFIG_ISDN_DIVERSION
#endif
#ifdef CONFIG_ISDN_DIVERSION
#include <linux/isdn_divertif.h>
#endif /* CONFIG_ISDN_DIVERSION */
#include "isdn_v110.h"

/* Debugflags */
#undef ISDN_DEBUG_STATCALLB

MODULE_DESCRIPTION("ISDN4Linux: link layer");
MODULE_AUTHOR("Fritz Elfert");
MODULE_LICENSE("GPL");

isdn_dev *dev;

static DEFINE_MUTEX(isdn_mutex);
static char *isdn_revision = "$Revision: 1.1.2.3 $";

extern char *isdn_net_revision;
#ifdef CONFIG_ISDN_PPP
extern char *isdn_ppp_revision;
#else
static char *isdn_ppp_revision = ": none $";
#endif
#ifdef CONFIG_ISDN_AUDIO
extern char *isdn_audio_revision;
#else
static char *isdn_audio_revision = ": none $";
#endif
extern char *isdn_v110_revision;

#ifdef CONFIG_ISDN_DIVERSION
static isdn_divert_if *divert_if; /* = NULL */
#endif /* CONFIG_ISDN_DIVERSION */


static int isdn_writebuf_stub(int, int, const u_char __user *, int);
static void set_global_features(void);
static int isdn_wildmat(char *s, char *p);
static int isdn_add_channels(isdn_driver_t *d, int drvidx, int n, int adding);

static inline void
isdn_lock_driver(isdn_driver_t *drv)
{
        try_module_get(drv->interface->owner);
        drv->locks++;
}

void
isdn_lock_drivers(void)
{
        int i;

        for (i = 0; i < ISDN_MAX_DRIVERS; i++) {
                if (!dev->drv[i])
                        continue;
                isdn_lock_driver(dev->drv[i]);
        }
}

static inline void
isdn_unlock_driver(isdn_driver_t *drv)
{
        if (drv->locks > 0) {
                drv->locks--;
                module_put(drv->interface->owner);
        }
}

void
isdn_unlock_drivers(void)
{
        int i;

        for (i = 0; i < ISDN_MAX_DRIVERS; i++) {
                if (!dev->drv[i])
                        continue;
                isdn_unlock_driver(dev->drv[i]);
        }
}

#if defined(ISDN_DEBUG_NET_DUMP) || defined(ISDN_DEBUG_MODEM_DUMP)
void
isdn_dumppkt(char *s, u_char *p, int len, int dumplen)
{
        int dumpc;

        printk(KERN_DEBUG "%s(%d) ", s, len);
        for (dumpc = 0; (dumpc < dumplen) && (len); len--, dumpc++)
                printk(" %02x", *p++);
        printk("\n");
}
#endif

/*
 * I picked the pattern-matching-functions from an old GNU-tar version (1.10)
 * It was originally written and put to PD by rs@mirror.TMC.COM (Rich Salz)
 */
static int
isdn_star(char *s, char *p)
{
        while (isdn_wildmat(s, p)) {
                if (*++s == '\0')
                        return (2);
        }
        return (0);
}

/*
 * Shell-type Pattern-matching for incoming caller-Ids
 * This function gets a string in s and checks, if it matches the pattern
 * given in p.
 *
 * Return:
 *   0 = match.
 *   1 = no match.
 *   2 = no match. Would eventually match, if s would be longer.
 *
 * Possible Patterns:
 *
 * '?'     matches one character
 * '*'     matches zero or more characters
 * [xyz]   matches the set of characters in brackets.
 * [^xyz]  matches any single character not in the set of characters
 */

static int
isdn_wildmat(char *s, char *p)
{
        register int last;
        register int matched;
        register int reverse;
        register int nostar = 1;

        if (!(*s) && !(*p))
                return (1);
        for (; *p; s++, p++)
                switch (*p) {
                case '\\':
                        /*
                         * Literal match with following character,
                         * fall through.
                         */
                        p++;
                default:
                        if (*s != *p)
                                return (*s == '\0') ? 2 : 1;
                                        continue;
                case '?':
                        /* Match anything. */
                        if (*s == '\0')
                                return (2);
                        continue;
                case '*':
                        nostar = 0;
                        /* Trailing star matches everything. */
                        return (*++p ? isdn_star(s, p) : 0);
                case '[':
                        /* [^....] means inverse character class. */
                        if ((reverse = (p[1] == '^')))
                                p++;
                        for (last = 0, matched = 0; *++p && (*p != ']'); last = *p)
                                /* This next line requires a good C compiler. */
                                if (*p == '-' ? *s <= *++p && *s >= last : *s == *p)
                                        matched = 1;
                        if (matched == reverse)
                                return (1);
                        continue;
                }
        return (*s == '\0') ? 0 : nostar;
}

int isdn_msncmp(const char *msn1, const char *msn2)
{
        char TmpMsn1[ISDN_MSNLEN];
        char TmpMsn2[ISDN_MSNLEN];
        char *p;

        for (p = TmpMsn1; *msn1 && *msn1 != ':';)  // Strip off a SPID
                *p++ = *msn1++;
        *p = '\0';

        for (p = TmpMsn2; *msn2 && *msn2 != ':';)  // Strip off a SPID
                *p++ = *msn2++;
        *p = '\0';

        return isdn_wildmat(TmpMsn1, TmpMsn2);
}

int
isdn_dc2minor(int di, int ch)
{
        int i;
        for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                if (dev->chanmap[i] == ch && dev->drvmap[i] == di)
                        return i;
        return -1;
}

static int isdn_timer_cnt1 = 0;
static int isdn_timer_cnt2 = 0;
static int isdn_timer_cnt3 = 0;

static void
isdn_timer_funct(struct timer_list *unused)
{
        int tf = dev->tflags;
        if (tf & ISDN_TIMER_FAST) {
                if (tf & ISDN_TIMER_MODEMREAD)
                        isdn_tty_readmodem();
                if (tf & ISDN_TIMER_MODEMPLUS)
                        isdn_tty_modem_escape();
                if (tf & ISDN_TIMER_MODEMXMIT)
                        isdn_tty_modem_xmit();
        }
        if (tf & ISDN_TIMER_SLOW) {
                if (++isdn_timer_cnt1 >= ISDN_TIMER_02SEC) {
                        isdn_timer_cnt1 = 0;
                        if (tf & ISDN_TIMER_NETDIAL)
                                isdn_net_dial();
                }
                if (++isdn_timer_cnt2 >= ISDN_TIMER_1SEC) {
                        isdn_timer_cnt2 = 0;
                        if (tf & ISDN_TIMER_NETHANGUP)
                                isdn_net_autohup();
                        if (++isdn_timer_cnt3 >= ISDN_TIMER_RINGING) {
                                isdn_timer_cnt3 = 0;
                                if (tf & ISDN_TIMER_MODEMRING)
                                        isdn_tty_modem_ring();
                        }
                        if (tf & ISDN_TIMER_CARRIER)
                                isdn_tty_carrier_timeout();
                }
        }
        if (tf)
                mod_timer(&dev->timer, jiffies + ISDN_TIMER_RES);
}

void
isdn_timer_ctrl(int tf, int onoff)
{
        unsigned long flags;
        int old_tflags;

        spin_lock_irqsave(&dev->timerlock, flags);
        if ((tf & ISDN_TIMER_SLOW) && (!(dev->tflags & ISDN_TIMER_SLOW))) {
                /* If the slow-timer wasn't activated until now */
                isdn_timer_cnt1 = 0;
                isdn_timer_cnt2 = 0;
        }
        old_tflags = dev->tflags;
        if (onoff)
                dev->tflags |= tf;
        else
                dev->tflags &= ~tf;
        if (dev->tflags && !old_tflags)
                mod_timer(&dev->timer, jiffies + ISDN_TIMER_RES);
        spin_unlock_irqrestore(&dev->timerlock, flags);
}

/*
 * Receive a packet from B-Channel. (Called from low-level-module)
 */
static void
isdn_receive_skb_callback(int di, int channel, struct sk_buff *skb)
{
        int i;

        if ((i = isdn_dc2minor(di, channel)) == -1) {
                dev_kfree_skb(skb);
                return;
        }
        /* Update statistics */
        dev->ibytes[i] += skb->len;

        /* First, try to deliver data to network-device */
        if (isdn_net_rcv_skb(i, skb))
                return;

        /* V.110 handling
         * makes sense for async streams only, so it is
         * called after possible net-device delivery.
         */
        if (dev->v110[i]) {
                atomic_inc(&dev->v110use[i]);
                skb = isdn_v110_decode(dev->v110[i], skb);
                atomic_dec(&dev->v110use[i]);
                if (!skb)
                        return;
        }

        /* No network-device found, deliver to tty or raw-channel */
        if (skb->len) {
                if (isdn_tty_rcv_skb(i, di, channel, skb))
                        return;
                wake_up_interruptible(&dev->drv[di]->rcv_waitq[channel]);
        } else
                dev_kfree_skb(skb);
}

/*
 * Intercept command from Linklevel to Lowlevel.
 * If layer 2 protocol is V.110 and this is not supported by current
 * lowlevel-driver, use driver's transparent mode and handle V.110 in
 * linklevel instead.
 */
int
isdn_command(isdn_ctrl *cmd)
{
        if (cmd->driver == -1) {
                printk(KERN_WARNING "isdn_command command(%x) driver -1\n", cmd->command);
                return (1);
        }
        if (!dev->drv[cmd->driver]) {
                printk(KERN_WARNING "isdn_command command(%x) dev->drv[%d] NULL\n",
                       cmd->command, cmd->driver);
                return (1);
        }
        if (!dev->drv[cmd->driver]->interface) {
                printk(KERN_WARNING "isdn_command command(%x) dev->drv[%d]->interface NULL\n",
                       cmd->command, cmd->driver);
                return (1);
        }
        if (cmd->command == ISDN_CMD_SETL2) {
                int idx = isdn_dc2minor(cmd->driver, cmd->arg & 255);
                unsigned long l2prot = (cmd->arg >> 8) & 255;
                unsigned long features = (dev->drv[cmd->driver]->interface->features
                                          >> ISDN_FEATURE_L2_SHIFT) &
                        ISDN_FEATURE_L2_MASK;
                unsigned long l2_feature = (1 << l2prot);

                switch (l2prot) {
                case ISDN_PROTO_L2_V11096:
                case ISDN_PROTO_L2_V11019:
                case ISDN_PROTO_L2_V11038:
                        /* If V.110 requested, but not supported by
                         * HL-driver, set emulator-flag and change
                         * Layer-2 to transparent
                         */
                        if (!(features & l2_feature)) {
                                dev->v110emu[idx] = l2prot;
                                cmd->arg = (cmd->arg & 255) |
                                        (ISDN_PROTO_L2_TRANS << 8);
                        } else
                                dev->v110emu[idx] = 0;
                }
        }
        return dev->drv[cmd->driver]->interface->command(cmd);
}

void
isdn_all_eaz(int di, int ch)
{
        isdn_ctrl cmd;

        if (di < 0)
                return;
        cmd.driver = di;
        cmd.arg = ch;
        cmd.command = ISDN_CMD_SETEAZ;
        cmd.parm.num[0] = '\0';
        isdn_command(&cmd);
}

/*
 * Begin of a CAPI like LL<->HL interface, currently used only for
 * supplementary service (CAPI 2.0 part III)
 */
#include <linux/isdn/capicmd.h>

static int
isdn_capi_rec_hl_msg(capi_msg *cm)
{
        switch (cm->Command) {
        case CAPI_FACILITY:
                /* in the moment only handled in tty */
                return (isdn_tty_capi_facility(cm));
        default:
                return (-1);
        }
}

static int
isdn_status_callback(isdn_ctrl *c)
{
        int di;
        u_long flags;
        int i;
        int r;
        int retval = 0;
        isdn_ctrl cmd;
        isdn_net_dev *p;

        di = c->driver;
        i = isdn_dc2minor(di, c->arg);
        switch (c->command) {
        case ISDN_STAT_BSENT:
                if (i < 0)
                        return -1;
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                if (isdn_net_stat_callback(i, c))
                        return 0;
                if (isdn_v110_stat_callback(i, c))
                        return 0;
                if (isdn_tty_stat_callback(i, c))
                        return 0;
                wake_up_interruptible(&dev->drv[di]->snd_waitq[c->arg]);
                break;
        case ISDN_STAT_STAVAIL:
                dev->drv[di]->stavail += c->arg;
                wake_up_interruptible(&dev->drv[di]->st_waitq);
                break;
        case ISDN_STAT_RUN:
                dev->drv[di]->flags |= DRV_FLAG_RUNNING;
                for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                        if (dev->drvmap[i] == di)
                                isdn_all_eaz(di, dev->chanmap[i]);
                set_global_features();
                break;
        case ISDN_STAT_STOP:
                dev->drv[di]->flags &= ~DRV_FLAG_RUNNING;
                break;
        case ISDN_STAT_ICALL:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "ICALL (net): %d %ld %s\n", di, c->arg, c->parm.num);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED) {
                        cmd.driver = di;
                        cmd.arg = c->arg;
                        cmd.command = ISDN_CMD_HANGUP;
                        isdn_command(&cmd);
                        return 0;
                }
                /* Try to find a network-interface which will accept incoming call */
                r = ((c->command == ISDN_STAT_ICALLW) ? 0 : isdn_net_find_icall(di, c->arg, i, &c->parm.setup));
                switch (r) {
                case 0:
                        /* No network-device replies.
                         * Try ttyI's.
                         * These return 0 on no match, 1 on match and
                         * 3 on eventually match, if CID is longer.
                         */
                        if (c->command == ISDN_STAT_ICALL)
                                if ((retval = isdn_tty_find_icall(di, c->arg, &c->parm.setup))) return (retval);
#ifdef CONFIG_ISDN_DIVERSION
                        if (divert_if)
                                if ((retval = divert_if->stat_callback(c)))
                                        return (retval); /* processed */
#endif /* CONFIG_ISDN_DIVERSION */
                        if ((!retval) && (dev->drv[di]->flags & DRV_FLAG_REJBUS)) {
                                /* No tty responding */
                                cmd.driver = di;
                                cmd.arg = c->arg;
                                cmd.command = ISDN_CMD_HANGUP;
                                isdn_command(&cmd);
                                retval = 2;
                        }
                        break;
                case 1:
                        /* Schedule connection-setup */
                        isdn_net_dial();
                        cmd.driver = di;
                        cmd.arg = c->arg;
                        cmd.command = ISDN_CMD_ACCEPTD;
                        for (p = dev->netdev; p; p = p->next)
                                if (p->local->isdn_channel == cmd.arg)
                                {
                                        strcpy(cmd.parm.setup.eazmsn, p->local->msn);
                                        isdn_command(&cmd);
                                        retval = 1;
                                        break;
                                }
                        break;

                case 2: /* For calling back, first reject incoming call ... */
                case 3: /* Interface found, but down, reject call actively  */
                        retval = 2;
                        printk(KERN_INFO "isdn: Rejecting Call\n");
                        cmd.driver = di;
                        cmd.arg = c->arg;
                        cmd.command = ISDN_CMD_HANGUP;
                        isdn_command(&cmd);
                        if (r == 3)
                                break;
                        /* Fall through */
                case 4:
                        /* ... then start callback. */
                        isdn_net_dial();
                        break;
                case 5:
                        /* Number would eventually match, if longer */
                        retval = 3;
                        break;
                }
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "ICALL: ret=%d\n", retval);
#endif
                return retval;
                break;
        case ISDN_STAT_CINF:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "CINF: %ld %s\n", c->arg, c->parm.num);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                if (strcmp(c->parm.num, "0"))
                        isdn_net_stat_callback(i, c);
                isdn_tty_stat_callback(i, c);
                break;
        case ISDN_STAT_CAUSE:
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "CAUSE: %ld %s\n", c->arg, c->parm.num);
#endif
                printk(KERN_INFO "isdn: %s,ch%ld cause: %s\n",
                       dev->drvid[di], c->arg, c->parm.num);
                isdn_tty_stat_callback(i, c);
#ifdef CONFIG_ISDN_DIVERSION
                if (divert_if)
                        divert_if->stat_callback(c);
#endif /* CONFIG_ISDN_DIVERSION */
                break;
        case ISDN_STAT_DISPLAY:
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "DISPLAY: %ld %s\n", c->arg, c->parm.display);
#endif
                isdn_tty_stat_callback(i, c);
#ifdef CONFIG_ISDN_DIVERSION
                if (divert_if)
                        divert_if->stat_callback(c);
#endif /* CONFIG_ISDN_DIVERSION */
                break;
        case ISDN_STAT_DCONN:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "DCONN: %ld\n", c->arg);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                /* Find any net-device, waiting for D-channel setup */
                if (isdn_net_stat_callback(i, c))
                        break;
                isdn_v110_stat_callback(i, c);
                /* Find any ttyI, waiting for D-channel setup */
                if (isdn_tty_stat_callback(i, c)) {
                        cmd.driver = di;
                        cmd.arg = c->arg;
                        cmd.command = ISDN_CMD_ACCEPTB;
                        isdn_command(&cmd);
                        break;
                }
                break;
        case ISDN_STAT_DHUP:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "DHUP: %ld\n", c->arg);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                dev->drv[di]->online &= ~(1 << (c->arg));
                isdn_info_update();
                /* Signal hangup to network-devices */
                if (isdn_net_stat_callback(i, c))
                        break;
                isdn_v110_stat_callback(i, c);
                if (isdn_tty_stat_callback(i, c))
                        break;
#ifdef CONFIG_ISDN_DIVERSION
                if (divert_if)
                        divert_if->stat_callback(c);
#endif /* CONFIG_ISDN_DIVERSION */
                break;
                break;
        case ISDN_STAT_BCONN:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "BCONN: %ld\n", c->arg);
#endif
                /* Signal B-channel-connect to network-devices */
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                dev->drv[di]->online |= (1 << (c->arg));
                isdn_info_update();
                if (isdn_net_stat_callback(i, c))
                        break;
                isdn_v110_stat_callback(i, c);
                if (isdn_tty_stat_callback(i, c))
                        break;
                break;
        case ISDN_STAT_BHUP:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "BHUP: %ld\n", c->arg);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                dev->drv[di]->online &= ~(1 << (c->arg));
                isdn_info_update();
#ifdef CONFIG_ISDN_X25
                /* Signal hangup to network-devices */
                if (isdn_net_stat_callback(i, c))
                        break;
#endif
                isdn_v110_stat_callback(i, c);
                if (isdn_tty_stat_callback(i, c))
                        break;
                break;
        case ISDN_STAT_NODCH:
                if (i < 0)
                        return -1;
#ifdef ISDN_DEBUG_STATCALLB
                printk(KERN_DEBUG "NODCH: %ld\n", c->arg);
#endif
                if (dev->global_flags & ISDN_GLOBAL_STOPPED)
                        return 0;
                if (isdn_net_stat_callback(i, c))
                        break;
                if (isdn_tty_stat_callback(i, c))
                        break;
                break;
        case ISDN_STAT_ADDCH:
                spin_lock_irqsave(&dev->lock, flags);
                if (isdn_add_channels(dev->drv[di], di, c->arg, 1)) {
                        spin_unlock_irqrestore(&dev->lock, flags);
                        return -1;
                }
                spin_unlock_irqrestore(&dev->lock, flags);
                isdn_info_update();
                break;
        case ISDN_STAT_DISCH:
                spin_lock_irqsave(&dev->lock, flags);
                for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                        if ((dev->drvmap[i] == di) &&
                            (dev->chanmap[i] == c->arg)) {
                                if (c->parm.num[0])
                                        dev->usage[i] &= ~ISDN_USAGE_DISABLED;
                                else
                                        if (USG_NONE(dev->usage[i])) {
                                                dev->usage[i] |= ISDN_USAGE_DISABLED;
                                        }
                                        else
                                                retval = -1;
                                break;
                        }
                spin_unlock_irqrestore(&dev->lock, flags);
                isdn_info_update();
                break;
        case ISDN_STAT_UNLOAD:
                while (dev->drv[di]->locks > 0) {
                        isdn_unlock_driver(dev->drv[di]);
                }
                spin_lock_irqsave(&dev->lock, flags);
                isdn_tty_stat_callback(i, c);
                for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                        if (dev->drvmap[i] == di) {
                                dev->drvmap[i] = -1;
                                dev->chanmap[i] = -1;
                                dev->usage[i] &= ~ISDN_USAGE_DISABLED;
                        }
                dev->drivers--;
                dev->channels -= dev->drv[di]->channels;
                kfree(dev->drv[di]->rcverr);
                kfree(dev->drv[di]->rcvcount);
                for (i = 0; i < dev->drv[di]->channels; i++)
                        skb_queue_purge(&dev->drv[di]->rpqueue[i]);
                kfree(dev->drv[di]->rpqueue);
                kfree(dev->drv[di]->rcv_waitq);
                kfree(dev->drv[di]);
                dev->drv[di] = NULL;
                dev->drvid[di][0] = '\0';
                isdn_info_update();
                set_global_features();
                spin_unlock_irqrestore(&dev->lock, flags);
                return 0;
        case ISDN_STAT_L1ERR:
                break;
        case CAPI_PUT_MESSAGE:
                return (isdn_capi_rec_hl_msg(&c->parm.cmsg));
#ifdef CONFIG_ISDN_TTY_FAX
        case ISDN_STAT_FAXIND:
                isdn_tty_stat_callback(i, c);
                break;
#endif
#ifdef CONFIG_ISDN_AUDIO
        case ISDN_STAT_AUDIO:
                isdn_tty_stat_callback(i, c);
                break;
#endif
#ifdef CONFIG_ISDN_DIVERSION
        case ISDN_STAT_PROT:
        case ISDN_STAT_REDIR:
                if (divert_if)
                        return (divert_if->stat_callback(c));
#endif /* CONFIG_ISDN_DIVERSION */
        default:
                return -1;
        }
        return 0;
}

/*
 * Get integer from char-pointer, set pointer to end of number
 */
int
isdn_getnum(char **p)
{
        int v = -1;

        while (*p[0] >= '0' && *p[0] <= '9')
                v = ((v < 0) ? 0 : (v * 10)) + (int) ((*p[0]++) - '0');
        return v;
}

#define DLE 0x10

/*
 * isdn_readbchan() tries to get data from the read-queue.
 * It MUST be called with interrupts off.
 *
 * Be aware that this is not an atomic operation when sleep != 0, even though
 * interrupts are turned off! Well, like that we are currently only called
 * on behalf of a read system call on raw device files (which are documented
 * to be dangerous and for debugging purpose only). The inode semaphore
 * takes care that this is not called for the same minor device number while
 * we are sleeping, but access is not serialized against simultaneous read()
 * from the corresponding ttyI device. Can other ugly events, like changes
 * of the mapping (di,ch)<->minor, happen during the sleep? --he
 */
int
isdn_readbchan(int di, int channel, u_char *buf, u_char *fp, int len, wait_queue_head_t *sleep)
{
        int count;
        int count_pull;
        int count_put;
        int dflag;
        struct sk_buff *skb;
        u_char *cp;

        if (!dev->drv[di])
                return 0;
        if (skb_queue_empty(&dev->drv[di]->rpqueue[channel])) {
                if (sleep)
                        wait_event_interruptible(*sleep,
                                !skb_queue_empty(&dev->drv[di]->rpqueue[channel]));
                else
                        return 0;
        }
        if (len > dev->drv[di]->rcvcount[channel])
                len = dev->drv[di]->rcvcount[channel];
        cp = buf;
        count = 0;
        while (len) {
                if (!(skb = skb_peek(&dev->drv[di]->rpqueue[channel])))
                        break;
#ifdef CONFIG_ISDN_AUDIO
                if (ISDN_AUDIO_SKB_LOCK(skb))
                        break;
                ISDN_AUDIO_SKB_LOCK(skb) = 1;
                if ((ISDN_AUDIO_SKB_DLECOUNT(skb)) || (dev->drv[di]->DLEflag & (1 << channel))) {
                        char *p = skb->data;
                        unsigned long DLEmask = (1 << channel);

                        dflag = 0;
                        count_pull = count_put = 0;
                        while ((count_pull < skb->len) && (len > 0)) {
                                len--;
                                if (dev->drv[di]->DLEflag & DLEmask) {
                                        *cp++ = DLE;
                                        dev->drv[di]->DLEflag &= ~DLEmask;
                                } else {
                                        *cp++ = *p;
                                        if (*p == DLE) {
                                                dev->drv[di]->DLEflag |= DLEmask;
                                                (ISDN_AUDIO_SKB_DLECOUNT(skb))--;
                                        }
                                        p++;
                                        count_pull++;
                                }
                                count_put++;
                        }
                        if (count_pull >= skb->len)
                                dflag = 1;
                } else {
#endif
                        /* No DLE's in buff, so simply copy it */
                        dflag = 1;
                        if ((count_pull = skb->len) > len) {
                                count_pull = len;
                                dflag = 0;
                        }
                        count_put = count_pull;
                        skb_copy_from_linear_data(skb, cp, count_put);
                        cp += count_put;
                        len -= count_put;
#ifdef CONFIG_ISDN_AUDIO
                }
#endif
                count += count_put;
                if (fp) {
                        memset(fp, 0, count_put);
                        fp += count_put;
                }
                if (dflag) {
                        /* We got all the data in this buff.
                         * Now we can dequeue it.
                         */
                        if (fp)
                                *(fp - 1) = 0xff;
#ifdef CONFIG_ISDN_AUDIO
                        ISDN_AUDIO_SKB_LOCK(skb) = 0;
#endif
                        skb = skb_dequeue(&dev->drv[di]->rpqueue[channel]);
                        dev_kfree_skb(skb);
                } else {
                        /* Not yet emptied this buff, so it
                         * must stay in the queue, for further calls
                         * but we pull off the data we got until now.
                         */
                        skb_pull(skb, count_pull);
#ifdef CONFIG_ISDN_AUDIO
                        ISDN_AUDIO_SKB_LOCK(skb) = 0;
#endif
                }
                dev->drv[di]->rcvcount[channel] -= count_put;
        }
        return count;
}

/*
 * isdn_readbchan_tty() tries to get data from the read-queue.
 * It MUST be called with interrupts off.
 *
 * Be aware that this is not an atomic operation when sleep != 0, even though
 * interrupts are turned off! Well, like that we are currently only called
 * on behalf of a read system call on raw device files (which are documented
 * to be dangerous and for debugging purpose only). The inode semaphore
 * takes care that this is not called for the same minor device number while
 * we are sleeping, but access is not serialized against simultaneous read()
 * from the corresponding ttyI device. Can other ugly events, like changes
 * of the mapping (di,ch)<->minor, happen during the sleep? --he
 */
int
isdn_readbchan_tty(int di, int channel, struct tty_port *port, int cisco_hack)
{
        int count;
        int count_pull;
        int count_put;
        int dflag;
        struct sk_buff *skb;
        char last = 0;
        int len;

        if (!dev->drv[di])
                return 0;
        if (skb_queue_empty(&dev->drv[di]->rpqueue[channel]))
                return 0;

        len = tty_buffer_request_room(port, dev->drv[di]->rcvcount[channel]);
        if (len == 0)
                return len;

        count = 0;
        while (len) {
                if (!(skb = skb_peek(&dev->drv[di]->rpqueue[channel])))
                        break;
#ifdef CONFIG_ISDN_AUDIO
                if (ISDN_AUDIO_SKB_LOCK(skb))
                        break;
                ISDN_AUDIO_SKB_LOCK(skb) = 1;
                if ((ISDN_AUDIO_SKB_DLECOUNT(skb)) || (dev->drv[di]->DLEflag & (1 << channel))) {
                        char *p = skb->data;
                        unsigned long DLEmask = (1 << channel);

                        dflag = 0;
                        count_pull = count_put = 0;
                        while ((count_pull < skb->len) && (len > 0)) {
                                /* push every character but the last to the tty buffer directly */
                                if (count_put)
                                        tty_insert_flip_char(port, last, TTY_NORMAL);
                                len--;
                                if (dev->drv[di]->DLEflag & DLEmask) {
                                        last = DLE;
                                        dev->drv[di]->DLEflag &= ~DLEmask;
                                } else {
                                        last = *p;
                                        if (last == DLE) {
                                                dev->drv[di]->DLEflag |= DLEmask;
                                                (ISDN_AUDIO_SKB_DLECOUNT(skb))--;
                                        }
                                        p++;
                                        count_pull++;
                                }
                                count_put++;
                        }
                        if (count_pull >= skb->len)
                                dflag = 1;
                } else {
#endif
                        /* No DLE's in buff, so simply copy it */
                        dflag = 1;
                        if ((count_pull = skb->len) > len) {
                                count_pull = len;
                                dflag = 0;
                        }
                        count_put = count_pull;
                        if (count_put > 1)
                                tty_insert_flip_string(port, skb->data, count_put - 1);
                        last = skb->data[count_put - 1];
                        len -= count_put;
#ifdef CONFIG_ISDN_AUDIO
                }
#endif
                count += count_put;
                if (dflag) {
                        /* We got all the data in this buff.
                         * Now we can dequeue it.
                         */
                        if (cisco_hack)
                                tty_insert_flip_char(port, last, 0xFF);
                        else
                                tty_insert_flip_char(port, last, TTY_NORMAL);
#ifdef CONFIG_ISDN_AUDIO
                        ISDN_AUDIO_SKB_LOCK(skb) = 0;
#endif
                        skb = skb_dequeue(&dev->drv[di]->rpqueue[channel]);
                        dev_kfree_skb(skb);
                } else {
                        tty_insert_flip_char(port, last, TTY_NORMAL);
                        /* Not yet emptied this buff, so it
                         * must stay in the queue, for further calls
                         * but we pull off the data we got until now.
                         */
                        skb_pull(skb, count_pull);
#ifdef CONFIG_ISDN_AUDIO
                        ISDN_AUDIO_SKB_LOCK(skb) = 0;
#endif
                }
                dev->drv[di]->rcvcount[channel] -= count_put;
        }
        return count;
}


static inline int
isdn_minor2drv(int minor)
{
        return (dev->drvmap[minor]);
}

static inline int
isdn_minor2chan(int minor)
{
        return (dev->chanmap[minor]);
}

static char *
isdn_statstr(void)
{
        static char istatbuf[2048];
        char *p;
        int i;

        sprintf(istatbuf, "idmap:\t");

        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                sprintf(p, "%s ", (dev->drvmap[i] < 0) ? "-" : dev->drvid[dev->drvmap[i]]);
                p = istatbuf + strlen(istatbuf);
        }
        sprintf(p, "\nchmap:\t");
        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                sprintf(p, "%d ", dev->chanmap[i]);
                p = istatbuf + strlen(istatbuf);
        }
        sprintf(p, "\ndrmap:\t");
        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                sprintf(p, "%d ", dev->drvmap[i]);
                p = istatbuf + strlen(istatbuf);
        }
        sprintf(p, "\nusage:\t");
        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                sprintf(p, "%d ", dev->usage[i]);
                p = istatbuf + strlen(istatbuf);
        }
        sprintf(p, "\nflags:\t");
        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_DRIVERS; i++) {
                if (dev->drv[i]) {
                        sprintf(p, "%ld ", dev->drv[i]->online);
                        p = istatbuf + strlen(istatbuf);
                } else {
                        sprintf(p, "? ");
                        p = istatbuf + strlen(istatbuf);
                }
        }
        sprintf(p, "\nphone:\t");
        p = istatbuf + strlen(istatbuf);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                sprintf(p, "%s ", dev->num[i]);
                p = istatbuf + strlen(istatbuf);
        }
        sprintf(p, "\n");
        return istatbuf;
}

/* Module interface-code */

void
isdn_info_update(void)
{
        infostruct *p = dev->infochain;

        while (p) {
                *(p->private) = 1;
                p = (infostruct *) p->next;
        }
        wake_up_interruptible(&(dev->info_waitq));
}

static ssize_t
isdn_read(struct file *file, char __user *buf, size_t count, loff_t *off)
{
        uint minor = iminor(file_inode(file));
        int len = 0;
        int drvidx;
        int chidx;
        int retval;
        char *p;

        mutex_lock(&isdn_mutex);
        if (minor == ISDN_MINOR_STATUS) {
                if (!file->private_data) {
                        if (file->f_flags & O_NONBLOCK) {
                                retval = -EAGAIN;
                                goto out;
                        }
                        wait_event_interruptible(dev->info_waitq,
                                                 file->private_data);
                }
                p = isdn_statstr();
                file->private_data = NULL;
                if ((len = strlen(p)) <= count) {
                        if (copy_to_user(buf, p, len)) {
                                retval = -EFAULT;
                                goto out;
                        }
                        *off += len;
                        retval = len;
                        goto out;
                }
                retval = 0;
                goto out;
        }
        if (!dev->drivers) {
                retval = -ENODEV;
                goto out;
        }
        if (minor <= ISDN_MINOR_BMAX) {
                printk(KERN_WARNING "isdn_read minor %d obsolete!\n", minor);
                drvidx = isdn_minor2drv(minor);
                if (drvidx < 0) {
                        retval = -ENODEV;
                        goto out;
                }
                if (!(dev->drv[drvidx]->flags & DRV_FLAG_RUNNING)) {
                        retval = -ENODEV;
                        goto out;
                }
                chidx = isdn_minor2chan(minor);
                if (!(p = kmalloc(count, GFP_KERNEL))) {
                        retval = -ENOMEM;
                        goto out;
                }
                len = isdn_readbchan(drvidx, chidx, p, NULL, count,
                                     &dev->drv[drvidx]->rcv_waitq[chidx]);
                *off += len;
                if (copy_to_user(buf, p, len))
                        len = -EFAULT;
                kfree(p);
                retval = len;
                goto out;
        }
        if (minor <= ISDN_MINOR_CTRLMAX) {
                drvidx = isdn_minor2drv(minor - ISDN_MINOR_CTRL);
                if (drvidx < 0) {
                        retval = -ENODEV;
                        goto out;
                }
                if (!dev->drv[drvidx]->stavail) {
                        if (file->f_flags & O_NONBLOCK) {
                                retval = -EAGAIN;
                                goto out;
                        }
                        wait_event_interruptible(dev->drv[drvidx]->st_waitq,
                                                 dev->drv[drvidx]->stavail);
                }
                if (dev->drv[drvidx]->interface->readstat) {
                        if (count > dev->drv[drvidx]->stavail)
                                count = dev->drv[drvidx]->stavail;
                        len = dev->drv[drvidx]->interface->readstat(buf, count,
                                                                    drvidx, isdn_minor2chan(minor - ISDN_MINOR_CTRL));
                        if (len < 0) {
                                retval = len;
                                goto out;
                        }
                } else {
                        len = 0;
                }
                if (len)
                        dev->drv[drvidx]->stavail -= len;
                else
                        dev->drv[drvidx]->stavail = 0;
                *off += len;
                retval = len;
                goto out;
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX) {
                retval = isdn_ppp_read(minor - ISDN_MINOR_PPP, file, buf, count);
                goto out;
        }
#endif
        retval = -ENODEV;
out:
        mutex_unlock(&isdn_mutex);
        return retval;
}

static ssize_t
isdn_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
{
        uint minor = iminor(file_inode(file));
        int drvidx;
        int chidx;
        int retval;

        if (minor == ISDN_MINOR_STATUS)
                return -EPERM;
        if (!dev->drivers)
                return -ENODEV;

        mutex_lock(&isdn_mutex);
        if (minor <= ISDN_MINOR_BMAX) {
                printk(KERN_WARNING "isdn_write minor %d obsolete!\n", minor);
                drvidx = isdn_minor2drv(minor);
                if (drvidx < 0) {
                        retval = -ENODEV;
                        goto out;
                }
                if (!(dev->drv[drvidx]->flags & DRV_FLAG_RUNNING)) {
                        retval = -ENODEV;
                        goto out;
                }
                chidx = isdn_minor2chan(minor);
                wait_event_interruptible(dev->drv[drvidx]->snd_waitq[chidx],
                        (retval = isdn_writebuf_stub(drvidx, chidx, buf, count)));
                goto out;
        }
        if (minor <= ISDN_MINOR_CTRLMAX) {
                drvidx = isdn_minor2drv(minor - ISDN_MINOR_CTRL);
                if (drvidx < 0) {
                        retval = -ENODEV;
                        goto out;
                }
                /*
                 * We want to use the isdnctrl device to load the firmware
                 *
                 if (!(dev->drv[drvidx]->flags & DRV_FLAG_RUNNING))
                 return -ENODEV;
                */
                if (dev->drv[drvidx]->interface->writecmd)
                        retval = dev->drv[drvidx]->interface->
                                writecmd(buf, count, drvidx,
                                         isdn_minor2chan(minor - ISDN_MINOR_CTRL));
                else
                        retval = count;
                goto out;
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX) {
                retval = isdn_ppp_write(minor - ISDN_MINOR_PPP, file, buf, count);
                goto out;
        }
#endif
        retval = -ENODEV;
out:
        mutex_unlock(&isdn_mutex);
        return retval;
}

static __poll_t
isdn_poll(struct file *file, poll_table *wait)
{
        __poll_t mask = 0;
        unsigned int minor = iminor(file_inode(file));
        int drvidx = isdn_minor2drv(minor - ISDN_MINOR_CTRL);

        mutex_lock(&isdn_mutex);
        if (minor == ISDN_MINOR_STATUS) {
                poll_wait(file, &(dev->info_waitq), wait);
                /* mask = EPOLLOUT | EPOLLWRNORM; */
                if (file->private_data) {
                        mask |= EPOLLIN | EPOLLRDNORM;
                }
                goto out;
        }
        if (minor >= ISDN_MINOR_CTRL && minor <= ISDN_MINOR_CTRLMAX) {
                if (drvidx < 0) {
                        /* driver deregistered while file open */
                        mask = EPOLLHUP;
                        goto out;
                }
                poll_wait(file, &(dev->drv[drvidx]->st_waitq), wait);
                mask = EPOLLOUT | EPOLLWRNORM;
                if (dev->drv[drvidx]->stavail) {
                        mask |= EPOLLIN | EPOLLRDNORM;
                }
                goto out;
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX) {
                mask = isdn_ppp_poll(file, wait);
                goto out;
        }
#endif
        mask = EPOLLERR;
out:
        mutex_unlock(&isdn_mutex);
        return mask;
}


static int
isdn_ioctl(struct file *file, uint cmd, ulong arg)
{
        uint minor = iminor(file_inode(file));
        isdn_ctrl c;
        int drvidx;
        int ret;
        int i;
        char __user *p;
        char *s;
        union iocpar {
                char name[10];
                char bname[22];
                isdn_ioctl_struct iocts;
                isdn_net_ioctl_phone phone;
                isdn_net_ioctl_cfg cfg;
        } iocpar;
        void __user *argp = (void __user *)arg;

#define name  iocpar.name
#define bname iocpar.bname
#define iocts iocpar.iocts
#define phone iocpar.phone
#define cfg   iocpar.cfg

        if (minor == ISDN_MINOR_STATUS) {
                switch (cmd) {
                case IIOCGETDVR:
                        return (TTY_DV +
                                (NET_DV << 8) +
                                (INF_DV << 16));
                case IIOCGETCPS:
                        if (arg) {
                                ulong __user *p = argp;
                                int i;
                                for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                                        put_user(dev->ibytes[i], p++);
                                        put_user(dev->obytes[i], p++);
                                }
                                return 0;
                        } else
                                return -EINVAL;
                        break;
                case IIOCNETGPN:
                        /* Get peer phone number of a connected
                         * isdn network interface */
                        if (arg) {
                                if (copy_from_user(&phone, argp, sizeof(phone)))
                                        return -EFAULT;
                                return isdn_net_getpeer(&phone, argp);
                        } else
                                return -EINVAL;
                default:
                        return -EINVAL;
                }
        }
        if (!dev->drivers)
                return -ENODEV;
        if (minor <= ISDN_MINOR_BMAX) {
                drvidx = isdn_minor2drv(minor);
                if (drvidx < 0)
                        return -ENODEV;
                if (!(dev->drv[drvidx]->flags & DRV_FLAG_RUNNING))
                        return -ENODEV;
                return 0;
        }
        if (minor <= ISDN_MINOR_CTRLMAX) {
/*
 * isdn net devices manage lots of configuration variables as linked lists.
 * Those lists must only be manipulated from user space. Some of the ioctl's
 * service routines access user space and are not atomic. Therefore, ioctl's
 * manipulating the lists and ioctl's sleeping while accessing the lists
 * are serialized by means of a semaphore.
 */
                switch (cmd) {
                case IIOCNETDWRSET:
                        printk(KERN_INFO "INFO: ISDN_DW_ABC_EXTENSION not enabled\n");
                        return (-EINVAL);
                case IIOCNETLCR:
                        printk(KERN_INFO "INFO: ISDN_ABC_LCR_SUPPORT not enabled\n");
                        return -ENODEV;
                case IIOCNETAIF:
                        /* Add a network-interface */
                        if (arg) {
                                if (copy_from_user(name, argp, sizeof(name)))
                                        return -EFAULT;
                                s = name;
                        } else {
                                s = NULL;
                        }
                        ret = mutex_lock_interruptible(&dev->mtx);
                        if (ret) return ret;
                        if ((s = isdn_net_new(s, NULL))) {
                                if (copy_to_user(argp, s, strlen(s) + 1)) {
                                        ret = -EFAULT;
                                } else {
                                        ret = 0;
                                }
                        } else
                                ret = -ENODEV;
                        mutex_unlock(&dev->mtx);
                        return ret;
                case IIOCNETASL:
                        /* Add a slave to a network-interface */
                        if (arg) {
                                if (copy_from_user(bname, argp, sizeof(bname) - 1))
                                        return -EFAULT;
                                bname[sizeof(bname)-1] = 0;
                        } else
                                return -EINVAL;
                        ret = mutex_lock_interruptible(&dev->mtx);
                        if (ret) return ret;
                        if ((s = isdn_net_newslave(bname))) {
                                if (copy_to_user(argp, s, strlen(s) + 1)) {
                                        ret = -EFAULT;
                                } else {
                                        ret = 0;
                                }
                        } else
                                ret = -ENODEV;
                        mutex_unlock(&dev->mtx);
                        return ret;
                case IIOCNETDIF:
                        /* Delete a network-interface */
                        if (arg) {
                                if (copy_from_user(name, argp, sizeof(name)))
                                        return -EFAULT;
                                ret = mutex_lock_interruptible(&dev->mtx);
                                if (ret) return ret;
                                ret = isdn_net_rm(name);
                                mutex_unlock(&dev->mtx);
                                return ret;
                        } else
                                return -EINVAL;
                case IIOCNETSCF:
                        /* Set configurable parameters of a network-interface */
                        if (arg) {
                                if (copy_from_user(&cfg, argp, sizeof(cfg)))
                                        return -EFAULT;
                                return isdn_net_setcfg(&cfg);
                        } else
                                return -EINVAL;
                case IIOCNETGCF:
                        /* Get configurable parameters of a network-interface */
                        if (arg) {
                                if (copy_from_user(&cfg, argp, sizeof(cfg)))
                                        return -EFAULT;
                                if (!(ret = isdn_net_getcfg(&cfg))) {
                                        if (copy_to_user(argp, &cfg, sizeof(cfg)))
                                                return -EFAULT;
                                }
                                return ret;
                        } else
                                return -EINVAL;
                case IIOCNETANM:
                        /* Add a phone-number to a network-interface */
                        if (arg) {
                                if (copy_from_user(&phone, argp, sizeof(phone)))
                                        return -EFAULT;
                                ret = mutex_lock_interruptible(&dev->mtx);
                                if (ret) return ret;
                                ret = isdn_net_addphone(&phone);
                                mutex_unlock(&dev->mtx);
                                return ret;
                        } else
                                return -EINVAL;
                case IIOCNETGNM:
                        /* Get list of phone-numbers of a network-interface */
                        if (arg) {
                                if (copy_from_user(&phone, argp, sizeof(phone)))
                                        return -EFAULT;
                                ret = mutex_lock_interruptible(&dev->mtx);
                                if (ret) return ret;
                                ret = isdn_net_getphones(&phone, argp);
                                mutex_unlock(&dev->mtx);
                                return ret;
                        } else
                                return -EINVAL;
                case IIOCNETDNM:
                        /* Delete a phone-number of a network-interface */
                        if (arg) {
                                if (copy_from_user(&phone, argp, sizeof(phone)))
                                        return -EFAULT;
                                ret = mutex_lock_interruptible(&dev->mtx);
                                if (ret) return ret;
                                ret = isdn_net_delphone(&phone);
                                mutex_unlock(&dev->mtx);
                                return ret;
                        } else
                                return -EINVAL;
                case IIOCNETDIL:
                        /* Force dialing of a network-interface */
                        if (arg) {
                                if (copy_from_user(name, argp, sizeof(name)))
                                        return -EFAULT;
                                return isdn_net_force_dial(name);
                        } else
                                return -EINVAL;
#ifdef CONFIG_ISDN_PPP
                case IIOCNETALN:
                        if (!arg)
                                return -EINVAL;
                        if (copy_from_user(name, argp, sizeof(name)))
                                return -EFAULT;
                        return isdn_ppp_dial_slave(name);
                case IIOCNETDLN:
                        if (!arg)
                                return -EINVAL;
                        if (copy_from_user(name, argp, sizeof(name)))
                                return -EFAULT;
                        return isdn_ppp_hangup_slave(name);
#endif
                case IIOCNETHUP:
                        /* Force hangup of a network-interface */
                        if (!arg)
                                return -EINVAL;
                        if (copy_from_user(name, argp, sizeof(name)))
                                return -EFAULT;
                        return isdn_net_force_hangup(name);
                        break;
                case IIOCSETVER:
                        dev->net_verbose = arg;
                        printk(KERN_INFO "isdn: Verbose-Level is %d\n", dev->net_verbose);
                        return 0;
                case IIOCSETGST:
                        if (arg)
                                dev->global_flags |= ISDN_GLOBAL_STOPPED;
                        else
                                dev->global_flags &= ~ISDN_GLOBAL_STOPPED;
                        printk(KERN_INFO "isdn: Global Mode %s\n",
                               (dev->global_flags & ISDN_GLOBAL_STOPPED) ? "stopped" : "running");
                        return 0;
                case IIOCSETBRJ:
                        drvidx = -1;
                        if (arg) {
                                int i;
                                char *p;
                                if (copy_from_user(&iocts, argp,
                                                   sizeof(isdn_ioctl_struct)))
                                        return -EFAULT;
                                iocts.drvid[sizeof(iocts.drvid) - 1] = 0;
                                if (strlen(iocts.drvid)) {
                                        if ((p = strchr(iocts.drvid, ',')))
                                                *p = 0;
                                        drvidx = -1;
                                        for (i = 0; i < ISDN_MAX_DRIVERS; i++)
                                                if (!(strcmp(dev->drvid[i], iocts.drvid))) {
                                                        drvidx = i;
                                                        break;
                                                }
                                }
                        }
                        if (drvidx == -1)
                                return -ENODEV;
                        if (iocts.arg)
                                dev->drv[drvidx]->flags |= DRV_FLAG_REJBUS;
                        else
                                dev->drv[drvidx]->flags &= ~DRV_FLAG_REJBUS;
                        return 0;
                case IIOCSIGPRF:
                        dev->profd = current;
                        return 0;
                        break;
                case IIOCGETPRF:
                        /* Get all Modem-Profiles */
                        if (arg) {
                                char __user *p = argp;
                                int i;

                                for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                                        if (copy_to_user(p, dev->mdm.info[i].emu.profile,
                                                         ISDN_MODEM_NUMREG))
                                                return -EFAULT;
                                        p += ISDN_MODEM_NUMREG;
                                        if (copy_to_user(p, dev->mdm.info[i].emu.pmsn, ISDN_MSNLEN))
                                                return -EFAULT;
                                        p += ISDN_MSNLEN;
                                        if (copy_to_user(p, dev->mdm.info[i].emu.plmsn, ISDN_LMSNLEN))
                                                return -EFAULT;
                                        p += ISDN_LMSNLEN;
                                }
                                return (ISDN_MODEM_NUMREG + ISDN_MSNLEN + ISDN_LMSNLEN) * ISDN_MAX_CHANNELS;
                        } else
                                return -EINVAL;
                        break;
                case IIOCSETPRF:
                        /* Set all Modem-Profiles */
                        if (arg) {
                                char __user *p = argp;
                                int i;

                                for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                                        if (copy_from_user(dev->mdm.info[i].emu.profile, p,
                                                           ISDN_MODEM_NUMREG))
                                                return -EFAULT;
                                        p += ISDN_MODEM_NUMREG;
                                        if (copy_from_user(dev->mdm.info[i].emu.plmsn, p, ISDN_LMSNLEN))
                                                return -EFAULT;
                                        p += ISDN_LMSNLEN;
                                        if (copy_from_user(dev->mdm.info[i].emu.pmsn, p, ISDN_MSNLEN))
                                                return -EFAULT;
                                        p += ISDN_MSNLEN;
                                }
                                return 0;
                        } else
                                return -EINVAL;
                        break;
                case IIOCSETMAP:
                case IIOCGETMAP:
                        /* Set/Get MSN->EAZ-Mapping for a driver */
                        if (arg) {

                                if (copy_from_user(&iocts, argp,
                                                   sizeof(isdn_ioctl_struct)))
                                        return -EFAULT;
                                iocts.drvid[sizeof(iocts.drvid) - 1] = 0;
                                if (strlen(iocts.drvid)) {
                                        drvidx = -1;
                                        for (i = 0; i < ISDN_MAX_DRIVERS; i++)
                                                if (!(strcmp(dev->drvid[i], iocts.drvid))) {
                                                        drvidx = i;
                                                        break;
                                                }
                                } else
                                        drvidx = 0;
                                if (drvidx == -1)
                                        return -ENODEV;
                                if (cmd == IIOCSETMAP) {
                                        int loop = 1;

                                        p = (char __user *) iocts.arg;
                                        i = 0;
                                        while (loop) {
                                                int j = 0;

                                                while (1) {
                                                        get_user(bname[j], p++);
                                                        switch (bname[j]) {
                                                        case '\0':
                                                                loop = 0;
                                                                /* Fall through */
                                                        case ',':
                                                                bname[j] = '\0';
                                                                strcpy(dev->drv[drvidx]->msn2eaz[i], bname);
                                                                j = ISDN_MSNLEN;
                                                                break;
                                                        default:
                                                                j++;
                                                        }
                                                        if (j >= ISDN_MSNLEN)
                                                                break;
                                                }
                                                if (++i > 9)
                                                        break;
                                        }
                                } else {
                                        p = (char __user *) iocts.arg;
                                        for (i = 0; i < 10; i++) {
                                                snprintf(bname, sizeof(bname), "%s%s",
                                                         strlen(dev->drv[drvidx]->msn2eaz[i]) ?
                                                         dev->drv[drvidx]->msn2eaz[i] : "_",
                                                         (i < 9) ? "," : "\0");
                                                if (copy_to_user(p, bname, strlen(bname) + 1))
                                                        return -EFAULT;
                                                p += strlen(bname);
                                        }
                                }
                                return 0;
                        } else
                                return -EINVAL;
                case IIOCDBGVAR:
                        return -EINVAL;
                default:
                        if ((cmd & IIOCDRVCTL) == IIOCDRVCTL)
                                cmd = ((cmd >> _IOC_NRSHIFT) & _IOC_NRMASK) & ISDN_DRVIOCTL_MASK;
                        else
                                return -EINVAL;
                        if (arg) {
                                int i;
                                char *p;
                                if (copy_from_user(&iocts, argp, sizeof(isdn_ioctl_struct)))
                                        return -EFAULT;
                                iocts.drvid[sizeof(iocts.drvid) - 1] = 0;
                                if (strlen(iocts.drvid)) {
                                        if ((p = strchr(iocts.drvid, ',')))
                                                *p = 0;
                                        drvidx = -1;
                                        for (i = 0; i < ISDN_MAX_DRIVERS; i++)
                                                if (!(strcmp(dev->drvid[i], iocts.drvid))) {
                                                        drvidx = i;
                                                        break;
                                                }
                                } else
                                        drvidx = 0;
                                if (drvidx == -1)
                                        return -ENODEV;
                                c.driver = drvidx;
                                c.command = ISDN_CMD_IOCTL;
                                c.arg = cmd;
                                memcpy(c.parm.num, &iocts.arg, sizeof(ulong));
                                ret = isdn_command(&c);
                                memcpy(&iocts.arg, c.parm.num, sizeof(ulong));
                                if (copy_to_user(argp, &iocts, sizeof(isdn_ioctl_struct)))
                                        return -EFAULT;
                                return ret;
                        } else
                                return -EINVAL;
                }
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX)
                return (isdn_ppp_ioctl(minor - ISDN_MINOR_PPP, file, cmd, arg));
#endif
        return -ENODEV;

#undef name
#undef bname
#undef iocts
#undef phone
#undef cfg
}

static long
isdn_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        int ret;

        mutex_lock(&isdn_mutex);
        ret = isdn_ioctl(file, cmd, arg);
        mutex_unlock(&isdn_mutex);

        return ret;
}

/*
 * Open the device code.
 */
static int
isdn_open(struct inode *ino, struct file *filep)
{
        uint minor = iminor(ino);
        int drvidx;
        int chidx;
        int retval = -ENODEV;

        mutex_lock(&isdn_mutex);
        if (minor == ISDN_MINOR_STATUS) {
                infostruct *p;

                if ((p = kmalloc(sizeof(infostruct), GFP_KERNEL))) {
                        p->next = (char *) dev->infochain;
                        p->private = (char *) &(filep->private_data);
                        dev->infochain = p;
                        /* At opening we allow a single update */
                        filep->private_data = (char *) 1;
                        retval = 0;
                        goto out;
                } else {
                        retval = -ENOMEM;
                        goto out;
                }
        }
        if (!dev->channels)
                goto out;
        if (minor <= ISDN_MINOR_BMAX) {
                printk(KERN_WARNING "isdn_open minor %d obsolete!\n", minor);
                drvidx = isdn_minor2drv(minor);
                if (drvidx < 0)
                        goto out;
                chidx = isdn_minor2chan(minor);
                if (!(dev->drv[drvidx]->flags & DRV_FLAG_RUNNING))
                        goto out;
                if (!(dev->drv[drvidx]->online & (1 << chidx)))
                        goto out;
                isdn_lock_drivers();
                retval = 0;
                goto out;
        }
        if (minor <= ISDN_MINOR_CTRLMAX) {
                drvidx = isdn_minor2drv(minor - ISDN_MINOR_CTRL);
                if (drvidx < 0)
                        goto out;
                isdn_lock_drivers();
                retval = 0;
                goto out;
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX) {
                retval = isdn_ppp_open(minor - ISDN_MINOR_PPP, filep);
                if (retval == 0)
                        isdn_lock_drivers();
                goto out;
        }
#endif
out:
        nonseekable_open(ino, filep);
        mutex_unlock(&isdn_mutex);
        return retval;
}

static int
isdn_close(struct inode *ino, struct file *filep)
{
        uint minor = iminor(ino);

        mutex_lock(&isdn_mutex);
        if (minor == ISDN_MINOR_STATUS) {
                infostruct *p = dev->infochain;
                infostruct *q = NULL;

                while (p) {
                        if (p->private == (char *) &(filep->private_data)) {
                                if (q)
                                        q->next = p->next;
                                else
                                        dev->infochain = (infostruct *) (p->next);
                                kfree(p);
                                goto out;
                        }
                        q = p;
                        p = (infostruct *) (p->next);
                }
                printk(KERN_WARNING "isdn: No private data while closing isdnctrl\n");
                goto out;
        }
        isdn_unlock_drivers();
        if (minor <= ISDN_MINOR_BMAX)
                goto out;
        if (minor <= ISDN_MINOR_CTRLMAX) {
                if (dev->profd == current)
                        dev->profd = NULL;
                goto out;
        }
#ifdef CONFIG_ISDN_PPP
        if (minor <= ISDN_MINOR_PPPMAX)
                isdn_ppp_release(minor - ISDN_MINOR_PPP, filep);
#endif

out:
        mutex_unlock(&isdn_mutex);
        return 0;
}

static const struct file_operations isdn_fops =
{
        .owner          = THIS_MODULE,
        .llseek         = no_llseek,
        .read           = isdn_read,
        .write          = isdn_write,
        .poll           = isdn_poll,
        .unlocked_ioctl = isdn_unlocked_ioctl,
        .open           = isdn_open,
        .release        = isdn_close,
};

char *
isdn_map_eaz2msn(char *msn, int di)
{
        isdn_driver_t *this = dev->drv[di];
        int i;

        if (strlen(msn) == 1) {
                i = msn[0] - '0';
                if ((i >= 0) && (i <= 9))
                        if (strlen(this->msn2eaz[i]))
                                return (this->msn2eaz[i]);
        }
        return (msn);
}

/*
 * Find an unused ISDN-channel, whose feature-flags match the
 * given L2- and L3-protocols.
 */
#define L2V (~(ISDN_FEATURE_L2_V11096 | ISDN_FEATURE_L2_V11019 | ISDN_FEATURE_L2_V11038))

/*
 * This function must be called with holding the dev->lock.
 */
int
isdn_get_free_channel(int usage, int l2_proto, int l3_proto, int pre_dev
                      , int pre_chan, char *msn)
{
        int i;
        ulong features;
        ulong vfeatures;

        features = ((1 << l2_proto) | (0x10000 << l3_proto));
        vfeatures = (((1 << l2_proto) | (0x10000 << l3_proto)) &
                     ~(ISDN_FEATURE_L2_V11096 | ISDN_FEATURE_L2_V11019 | ISDN_FEATURE_L2_V11038));
        /* If Layer-2 protocol is V.110, accept drivers with
         * transparent feature even if these don't support V.110
         * because we can emulate this in linklevel.
         */
        for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                if (USG_NONE(dev->usage[i]) &&
                    (dev->drvmap[i] != -1)) {
                        int d = dev->drvmap[i];
                        if ((dev->usage[i] & ISDN_USAGE_EXCLUSIVE) &&
                            ((pre_dev != d) || (pre_chan != dev->chanmap[i])))
                                continue;
                        if (!strcmp(isdn_map_eaz2msn(msn, d), "-"))
                                continue;
                        if (dev->usage[i] & ISDN_USAGE_DISABLED)
                                continue; /* usage not allowed */
                        if (dev->drv[d]->flags & DRV_FLAG_RUNNING) {
                                if (((dev->drv[d]->interface->features & features) == features) ||
                                    (((dev->drv[d]->interface->features & vfeatures) == vfeatures) &&
                                     (dev->drv[d]->interface->features & ISDN_FEATURE_L2_TRANS))) {
                                        if ((pre_dev < 0) || (pre_chan < 0)) {
                                                dev->usage[i] &= ISDN_USAGE_EXCLUSIVE;
                                                dev->usage[i] |= usage;
                                                isdn_info_update();
                                                return i;
                                        } else {
                                                if ((pre_dev == d) && (pre_chan == dev->chanmap[i])) {
                                                        dev->usage[i] &= ISDN_USAGE_EXCLUSIVE;
                                                        dev->usage[i] |= usage;
                                                        isdn_info_update();
                                                        return i;
                                                }
                                        }
                                }
                        }
                }
        return -1;
}

/*
 * Set state of ISDN-channel to 'unused'
 */
void
isdn_free_channel(int di, int ch, int usage)
{
        int i;

        if ((di < 0) || (ch < 0)) {
                printk(KERN_WARNING "%s: called with invalid drv(%d) or channel(%d)\n",
                       __func__, di, ch);
                return;
        }
        for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                if (((!usage) || ((dev->usage[i] & ISDN_USAGE_MASK) == usage)) &&
                    (dev->drvmap[i] == di) &&
                    (dev->chanmap[i] == ch)) {
                        dev->usage[i] &= (ISDN_USAGE_NONE | ISDN_USAGE_EXCLUSIVE);
                        strcpy(dev->num[i], "???");
                        dev->ibytes[i] = 0;
                        dev->obytes[i] = 0;
// 20.10.99 JIM, try to reinitialize v110 !
                        dev->v110emu[i] = 0;
                        atomic_set(&(dev->v110use[i]), 0);
                        isdn_v110_close(dev->v110[i]);
                        dev->v110[i] = NULL;
// 20.10.99 JIM, try to reinitialize v110 !
                        isdn_info_update();
                        if (dev->drv[di])
                                skb_queue_purge(&dev->drv[di]->rpqueue[ch]);
                }
}

/*
 * Cancel Exclusive-Flag for ISDN-channel
 */
void
isdn_unexclusive_channel(int di, int ch)
{
        int i;

        for (i = 0; i < ISDN_MAX_CHANNELS; i++)
                if ((dev->drvmap[i] == di) &&
                    (dev->chanmap[i] == ch)) {
                        dev->usage[i] &= ~ISDN_USAGE_EXCLUSIVE;
                        isdn_info_update();
                        return;
                }
}

/*
 *  writebuf replacement for SKB_ABLE drivers
 */
static int
isdn_writebuf_stub(int drvidx, int chan, const u_char __user *buf, int len)
{
        int ret;
        int hl = dev->drv[drvidx]->interface->hl_hdrlen;
        struct sk_buff *skb = alloc_skb(hl + len, GFP_ATOMIC);

        if (!skb)
                return -ENOMEM;
        skb_reserve(skb, hl);
        if (copy_from_user(skb_put(skb, len), buf, len)) {
                dev_kfree_skb(skb);
                return -EFAULT;
        }
        ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, 1, skb);
        if (ret <= 0)
                dev_kfree_skb(skb);
        if (ret > 0)
                dev->obytes[isdn_dc2minor(drvidx, chan)] += ret;
        return ret;
}

/*
 * Return: length of data on success, -ERRcode on failure.
 */
int
isdn_writebuf_skb_stub(int drvidx, int chan, int ack, struct sk_buff *skb)
{
        int ret;
        struct sk_buff *nskb = NULL;
        int v110_ret = skb->len;
        int idx = isdn_dc2minor(drvidx, chan);

        if (dev->v110[idx]) {
                atomic_inc(&dev->v110use[idx]);
                nskb = isdn_v110_encode(dev->v110[idx], skb);
                atomic_dec(&dev->v110use[idx]);
                if (!nskb)
                        return 0;
                v110_ret = *((int *)nskb->data);
                skb_pull(nskb, sizeof(int));
                if (!nskb->len) {
                        dev_kfree_skb(nskb);
                        return v110_ret;
                }
                /* V.110 must always be acknowledged */
                ack = 1;
                ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, ack, nskb);

        } else {
                int hl = dev->drv[drvidx]->interface->hl_hdrlen;

                if (skb_headroom(skb) < hl) {
                        /*
                         * This should only occur when new HL driver with
                         * increased hl_hdrlen was loaded after netdevice
                         * was created and connected to the new driver.
                         *
                         * The V.110 branch (re-allocates on its own) does
                         * not need this
                         */
                        struct sk_buff *skb_tmp;

                        skb_tmp = skb_realloc_headroom(skb, hl);
                        printk(KERN_DEBUG "isdn_writebuf_skb_stub: reallocating headroom%s\n", skb_tmp ? "" : " failed");
                        if (!skb_tmp) return -ENOMEM; /* 0 better? */
                        ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, ack, skb_tmp);
                        if (ret > 0) {
                                dev_kfree_skb(skb);
                        } else {
                                dev_kfree_skb(skb_tmp);
                        }
                } else {
                        ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, ack, skb);
                }
        }
        if (ret > 0) {
                dev->obytes[idx] += ret;
                if (dev->v110[idx]) {
                        atomic_inc(&dev->v110use[idx]);
                        dev->v110[idx]->skbuser++;
                        atomic_dec(&dev->v110use[idx]);
                        /* For V.110 return unencoded data length */
                        ret = v110_ret;
                        /* if the complete frame was send we free the skb;
                           if not upper function will requeue the skb */
                        if (ret == skb->len)
                                dev_kfree_skb(skb);
                }
        } else
                if (dev->v110[idx])
                        dev_kfree_skb(nskb);
        return ret;
}

static int
isdn_add_channels(isdn_driver_t *d, int drvidx, int n, int adding)
{
        int j, k, m;

        init_waitqueue_head(&d->st_waitq);
        if (d->flags & DRV_FLAG_RUNNING)
                return -1;
        if (n < 1) return 0;

        m = (adding) ? d->channels + n : n;

        if (dev->channels + n > ISDN_MAX_CHANNELS) {
                printk(KERN_WARNING "register_isdn: Max. %d channels supported\n",
                       ISDN_MAX_CHANNELS);
                return -1;
        }

        if ((adding) && (d->rcverr))
                kfree(d->rcverr);
        if (!(d->rcverr = kcalloc(m, sizeof(int), GFP_ATOMIC))) {
                printk(KERN_WARNING "register_isdn: Could not alloc rcverr\n");
                return -1;
        }

        if ((adding) && (d->rcvcount))
                kfree(d->rcvcount);
        if (!(d->rcvcount = kcalloc(m, sizeof(int), GFP_ATOMIC))) {
                printk(KERN_WARNING "register_isdn: Could not alloc rcvcount\n");
                if (!adding)
                        kfree(d->rcverr);
                return -1;
        }

        if ((adding) && (d->rpqueue)) {
                for (j = 0; j < d->channels; j++)
                        skb_queue_purge(&d->rpqueue[j]);
                kfree(d->rpqueue);
        }
        d->rpqueue = kmalloc_array(m, sizeof(struct sk_buff_head), GFP_ATOMIC);
        if (!d->rpqueue) {
                printk(KERN_WARNING "register_isdn: Could not alloc rpqueue\n");
                if (!adding) {
                        kfree(d->rcvcount);
                        kfree(d->rcverr);
                }
                return -1;
        }
        for (j = 0; j < m; j++) {
                skb_queue_head_init(&d->rpqueue[j]);
        }

        if ((adding) && (d->rcv_waitq))
                kfree(d->rcv_waitq);
        d->rcv_waitq = kmalloc(array3_size(sizeof(wait_queue_head_t), 2, m),
                               GFP_ATOMIC);
        if (!d->rcv_waitq) {
                printk(KERN_WARNING "register_isdn: Could not alloc rcv_waitq\n");
                if (!adding) {
                        kfree(d->rpqueue);
                        kfree(d->rcvcount);
                        kfree(d->rcverr);
                }
                return -1;
        }
        d->snd_waitq = d->rcv_waitq + m;
        for (j = 0; j < m; j++) {
                init_waitqueue_head(&d->rcv_waitq[j]);
                init_waitqueue_head(&d->snd_waitq[j]);
        }

        dev->channels += n;
        for (j = d->channels; j < m; j++)
                for (k = 0; k < ISDN_MAX_CHANNELS; k++)
                        if (dev->chanmap[k] < 0) {
                                dev->chanmap[k] = j;
                                dev->drvmap[k] = drvidx;
                                break;
                        }
        d->channels = m;
        return 0;
}

/*
 * Low-level-driver registration
 */

static void
set_global_features(void)
{
        int drvidx;

        dev->global_features = 0;
        for (drvidx = 0; drvidx < ISDN_MAX_DRIVERS; drvidx++) {
                if (!dev->drv[drvidx])
                        continue;
                if (dev->drv[drvidx]->interface)
                        dev->global_features |= dev->drv[drvidx]->interface->features;
        }
}

#ifdef CONFIG_ISDN_DIVERSION

static char *map_drvname(int di)
{
        if ((di < 0) || (di >= ISDN_MAX_DRIVERS))
                return (NULL);
        return (dev->drvid[di]); /* driver name */
} /* map_drvname */

static int map_namedrv(char *id)
{  int i;

        for (i = 0; i < ISDN_MAX_DRIVERS; i++)
        { if (!strcmp(dev->drvid[i], id))
                        return (i);
        }
        return (-1);
} /* map_namedrv */

int DIVERT_REG_NAME(isdn_divert_if *i_div)
{
        if (i_div->if_magic != DIVERT_IF_MAGIC)
                return (DIVERT_VER_ERR);
        switch (i_div->cmd)
        {
        case DIVERT_CMD_REL:
                if (divert_if != i_div)
                        return (DIVERT_REL_ERR);
                divert_if = NULL; /* free interface */
                return (DIVERT_NO_ERR);

        case DIVERT_CMD_REG:
                if (divert_if)
                        return (DIVERT_REG_ERR);
                i_div->ll_cmd = isdn_command; /* set command function */
                i_div->drv_to_name = map_drvname;
                i_div->name_to_drv = map_namedrv;
                divert_if = i_div; /* remember interface */
                return (DIVERT_NO_ERR);

        default:
                return (DIVERT_CMD_ERR);
        }
} /* DIVERT_REG_NAME */

EXPORT_SYMBOL(DIVERT_REG_NAME);

#endif /* CONFIG_ISDN_DIVERSION */


EXPORT_SYMBOL(register_isdn);
#ifdef CONFIG_ISDN_PPP
EXPORT_SYMBOL(isdn_ppp_register_compressor);
EXPORT_SYMBOL(isdn_ppp_unregister_compressor);
#endif

int
register_isdn(isdn_if *i)
{
        isdn_driver_t *d;
        int j;
        ulong flags;
        int drvidx;

        if (dev->drivers >= ISDN_MAX_DRIVERS) {
                printk(KERN_WARNING "register_isdn: Max. %d drivers supported\n",
                       ISDN_MAX_DRIVERS);
                return 0;
        }
        if (!i->writebuf_skb) {
                printk(KERN_WARNING "register_isdn: No write routine given.\n");
                return 0;
        }
        if (!(d = kzalloc(sizeof(isdn_driver_t), GFP_KERNEL))) {
                printk(KERN_WARNING "register_isdn: Could not alloc driver-struct\n");
                return 0;
        }

        d->maxbufsize = i->maxbufsize;
        d->pktcount = 0;
        d->stavail = 0;
        d->flags = DRV_FLAG_LOADED;
        d->online = 0;
        d->interface = i;
        d->channels = 0;
        spin_lock_irqsave(&dev->lock, flags);
        for (drvidx = 0; drvidx < ISDN_MAX_DRIVERS; drvidx++)
                if (!dev->drv[drvidx])
                        break;
        if (isdn_add_channels(d, drvidx, i->channels, 0)) {
                spin_unlock_irqrestore(&dev->lock, flags);
                kfree(d);
                return 0;
        }
        i->channels = drvidx;
        i->rcvcallb_skb = isdn_receive_skb_callback;
        i->statcallb = isdn_status_callback;
        if (!strlen(i->id))
                sprintf(i->id, "line%d", drvidx);
        for (j = 0; j < drvidx; j++)
                if (!strcmp(i->id, dev->drvid[j]))
                        sprintf(i->id, "line%d", drvidx);
        dev->drv[drvidx] = d;
        strcpy(dev->drvid[drvidx], i->id);
        isdn_info_update();
        dev->drivers++;
        set_global_features();
        spin_unlock_irqrestore(&dev->lock, flags);
        return 1;
}

/*
*****************************************************************************
* And now the modules code.
*****************************************************************************
*/

static char *
isdn_getrev(const char *revision)
{
        char *rev;
        char *p;

        if ((p = strchr(revision, ':'))) {
                rev = p + 2;
                p = strchr(rev, '$');
                *--p = 0;
        } else
                rev = "???";
        return rev;
}

/*
 * Allocate and initialize all data, register modem-devices
 */
static int __init isdn_init(void)
{
        int i;
        char tmprev[50];

        dev = vzalloc(sizeof(isdn_dev));
        if (!dev) {
                printk(KERN_WARNING "isdn: Could not allocate device-struct.\n");
                return -EIO;
        }
        timer_setup(&dev->timer, isdn_timer_funct, 0);
        spin_lock_init(&dev->lock);
        spin_lock_init(&dev->timerlock);
#ifdef MODULE
        dev->owner = THIS_MODULE;
#endif
        mutex_init(&dev->mtx);
        init_waitqueue_head(&dev->info_waitq);
        for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
                dev->drvmap[i] = -1;
                dev->chanmap[i] = -1;
                dev->m_idx[i] = -1;
                strcpy(dev->num[i], "???");
        }
        if (register_chrdev(ISDN_MAJOR, "isdn", &isdn_fops)) {
                printk(KERN_WARNING "isdn: Could not register control devices\n");
                vfree(dev);
                return -EIO;
        }
        if ((isdn_tty_modem_init()) < 0) {
                printk(KERN_WARNING "isdn: Could not register tty devices\n");
                vfree(dev);
                unregister_chrdev(ISDN_MAJOR, "isdn");
                return -EIO;
        }
#ifdef CONFIG_ISDN_PPP
        if (isdn_ppp_init() < 0) {
                printk(KERN_WARNING "isdn: Could not create PPP-device-structs\n");
                isdn_tty_exit();
                unregister_chrdev(ISDN_MAJOR, "isdn");
                vfree(dev);
                return -EIO;
        }
#endif                          /* CONFIG_ISDN_PPP */

        strcpy(tmprev, isdn_revision);
        printk(KERN_NOTICE "ISDN subsystem Rev: %s/", isdn_getrev(tmprev));
        strcpy(tmprev, isdn_net_revision);
        printk("%s/", isdn_getrev(tmprev));
        strcpy(tmprev, isdn_ppp_revision);
        printk("%s/", isdn_getrev(tmprev));
        strcpy(tmprev, isdn_audio_revision);
        printk("%s/", isdn_getrev(tmprev));
        strcpy(tmprev, isdn_v110_revision);
        printk("%s", isdn_getrev(tmprev));

#ifdef MODULE
        printk(" loaded\n");
#else
        printk("\n");
#endif
        isdn_info_update();
        return 0;
}

/*
 * Unload module
 */
static void __exit isdn_exit(void)
{
#ifdef CONFIG_ISDN_PPP
        isdn_ppp_cleanup();
#endif
        if (isdn_net_rmall() < 0) {
                printk(KERN_WARNING "isdn: net-device busy, remove cancelled\n");
                return;
        }
        isdn_tty_exit();
        unregister_chrdev(ISDN_MAJOR, "isdn");
        del_timer_sync(&dev->timer);
        /* call vfree with interrupts enabled, else it will hang */
        vfree(dev);
        printk(KERN_NOTICE "ISDN-subsystem unloaded\n");
}

module_init(isdn_init);
module_exit(isdn_exit);