+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *     Things to sort out:
- *
- *     o       tbusy handling
- *     o       allow users to set the parameters
- *     o       sync/async switching ?
- *
- *     Note: This does _not_ implement CCITT X.25 asynchronous framing
- *     recommendations. Its primarily for testing purposes. If you wanted
- *     to do CCITT then in theory all you need is to nick the HDLC async
- *     checksum routines from ppp.c
- *      Changes:
- *
- *     2000-10-29      Henner Eisen    lapb_data_indication() return status.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
-
-#include <linux/uaccess.h>
-#include <linux/bitops.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/interrupt.h>
-#include <linux/in.h>
-#include <linux/tty.h>
-#include <linux/errno.h>
-#include <linux/netdevice.h>
-#include <linux/etherdevice.h>
-#include <linux/skbuff.h>
-#include <linux/if_arp.h>
-#include <linux/lapb.h>
-#include <linux/init.h>
-#include <linux/rtnetlink.h>
-#include <linux/slab.h>
-#include <net/x25device.h>
-#include "x25_asy.h"
-
-static struct net_device **x25_asy_devs;
-static int x25_asy_maxdev = SL_NRUNIT;
-
-module_param(x25_asy_maxdev, int, 0);
-MODULE_LICENSE("GPL");
-
-static int x25_asy_esc(unsigned char *p, unsigned char *d, int len);
-static void x25_asy_unesc(struct x25_asy *sl, unsigned char c);
-static void x25_asy_setup(struct net_device *dev);
-
-/* Find a free X.25 channel, and link in this `tty' line. */
-static struct x25_asy *x25_asy_alloc(void)
-{
-       struct net_device *dev = NULL;
-       struct x25_asy *sl;
-       int i;
-
-       if (x25_asy_devs == NULL)
-               return NULL;    /* Master array missing ! */
-
-       for (i = 0; i < x25_asy_maxdev; i++) {
-               dev = x25_asy_devs[i];
-
-               /* Not allocated ? */
-               if (dev == NULL)
-                       break;
-
-               sl = netdev_priv(dev);
-               /* Not in use ? */
-               if (!test_and_set_bit(SLF_INUSE, &sl->flags))
-                       return sl;
-       }
-
-
-       /* Sorry, too many, all slots in use */
-       if (i >= x25_asy_maxdev)
-               return NULL;
-
-       /* If no channels are available, allocate one */
-       if (!dev) {
-               char name[IFNAMSIZ];
-               sprintf(name, "x25asy%d", i);
-
-               dev = alloc_netdev(sizeof(struct x25_asy), name,
-                                  NET_NAME_UNKNOWN, x25_asy_setup);
-               if (!dev)
-                       return NULL;
-
-               /* Initialize channel control data */
-               sl = netdev_priv(dev);
-               dev->base_addr    = i;
-
-               /* register device so that it can be ifconfig'ed       */
-               if (register_netdev(dev) == 0) {
-                       /* (Re-)Set the INUSE bit.   Very Important! */
-                       set_bit(SLF_INUSE, &sl->flags);
-                       x25_asy_devs[i] = dev;
-                       return sl;
-               } else {
-                       pr_warn("%s(): register_netdev() failure\n", __func__);
-                       free_netdev(dev);
-               }
-       }
-       return NULL;
-}
-
-
-/* Free an X.25 channel. */
-static void x25_asy_free(struct x25_asy *sl)
-{
-       /* Free all X.25 frame buffers. */
-       kfree(sl->rbuff);
-       sl->rbuff = NULL;
-       kfree(sl->xbuff);
-       sl->xbuff = NULL;
-
-       if (!test_and_clear_bit(SLF_INUSE, &sl->flags))
-               netdev_err(sl->dev, "x25_asy_free for already free unit\n");
-}
-
-static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-       unsigned char *xbuff, *rbuff;
-       int len;
-
-       len = 2 * newmtu;
-       xbuff = kmalloc(len + 4, GFP_ATOMIC);
-       rbuff = kmalloc(len + 4, GFP_ATOMIC);
-
-       if (xbuff == NULL || rbuff == NULL) {
-               kfree(xbuff);
-               kfree(rbuff);
-               return -ENOMEM;
-       }
-
-       spin_lock_bh(&sl->lock);
-       xbuff    = xchg(&sl->xbuff, xbuff);
-       if (sl->xleft)  {
-               if (sl->xleft <= len)  {
-                       memcpy(sl->xbuff, sl->xhead, sl->xleft);
-               } else  {
-                       sl->xleft = 0;
-                       dev->stats.tx_dropped++;
-               }
-       }
-       sl->xhead = sl->xbuff;
-
-       rbuff    = xchg(&sl->rbuff, rbuff);
-       if (sl->rcount)  {
-               if (sl->rcount <= len) {
-                       memcpy(sl->rbuff, rbuff, sl->rcount);
-               } else  {
-                       sl->rcount = 0;
-                       dev->stats.rx_over_errors++;
-                       set_bit(SLF_ERROR, &sl->flags);
-               }
-       }
-
-       dev->mtu    = newmtu;
-       sl->buffsize = len;
-
-       spin_unlock_bh(&sl->lock);
-
-       kfree(xbuff);
-       kfree(rbuff);
-       return 0;
-}
-
-
-/* Set the "sending" flag.  This must be atomic, hence the ASM. */
-
-static inline void x25_asy_lock(struct x25_asy *sl)
-{
-       netif_stop_queue(sl->dev);
-}
-
-
-/* Clear the "sending" flag.  This must be atomic, hence the ASM. */
-
-static inline void x25_asy_unlock(struct x25_asy *sl)
-{
-       netif_wake_queue(sl->dev);
-}
-
-/* Send an LAPB frame to the LAPB module to process. */
-
-static void x25_asy_bump(struct x25_asy *sl)
-{
-       struct net_device *dev = sl->dev;
-       struct sk_buff *skb;
-       int count;
-       int err;
-
-       count = sl->rcount;
-       dev->stats.rx_bytes += count;
-
-       skb = dev_alloc_skb(count);
-       if (skb == NULL) {
-               netdev_warn(sl->dev, "memory squeeze, dropping packet\n");
-               dev->stats.rx_dropped++;
-               return;
-       }
-       skb_put_data(skb, sl->rbuff, count);
-       err = lapb_data_received(sl->dev, skb);
-       if (err != LAPB_OK) {
-               kfree_skb(skb);
-               printk(KERN_DEBUG "x25_asy: data received err - %d\n", err);
-       } else {
-               dev->stats.rx_packets++;
-       }
-}
-
-/* Encapsulate one IP datagram and stuff into a TTY queue. */
-static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len)
-{
-       unsigned char *p;
-       int actual, count, mtu = sl->dev->mtu;
-
-       if (len > mtu) {
-               /* Sigh, shouldn't occur BUT ... */
-               len = mtu;
-               printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n",
-                                       sl->dev->name);
-               sl->dev->stats.tx_dropped++;
-               x25_asy_unlock(sl);
-               return;
-       }
-
-       p = icp;
-       count = x25_asy_esc(p, sl->xbuff, len);
-
-       /* Order of next two lines is *very* important.
-        * When we are sending a little amount of data,
-        * the transfer may be completed inside driver.write()
-        * routine, because it's running with interrupts enabled.
-        * In this case we *never* got WRITE_WAKEUP event,
-        * if we did not request it before write operation.
-        *       14 Oct 1994  Dmitry Gorodchanin.
-        */
-       set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
-       actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
-       sl->xleft = count - actual;
-       sl->xhead = sl->xbuff + actual;
-}
-
-/*
- * Called by the driver when there's room for more data.  If we have
- * more packets to send, we send them here.
- */
-static void x25_asy_write_wakeup(struct tty_struct *tty)
-{
-       int actual;
-       struct x25_asy *sl = tty->disc_data;
-
-       /* First make sure we're connected. */
-       if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
-               return;
-
-       if (sl->xleft <= 0) {
-               /* Now serial buffer is almost free & we can start
-                * transmission of another packet */
-               sl->dev->stats.tx_packets++;
-               clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
-               x25_asy_unlock(sl);
-               return;
-       }
-
-       actual = tty->ops->write(tty, sl->xhead, sl->xleft);
-       sl->xleft -= actual;
-       sl->xhead += actual;
-}
-
-static void x25_asy_timeout(struct net_device *dev, unsigned int txqueue)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-
-       spin_lock(&sl->lock);
-       if (netif_queue_stopped(dev)) {
-               /* May be we must check transmitter timeout here ?
-                *      14 Oct 1994 Dmitry Gorodchanin.
-                */
-               netdev_warn(dev, "transmit timed out, %s?\n",
-                           (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
-                           "bad line quality" : "driver error");
-               sl->xleft = 0;
-               clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
-               x25_asy_unlock(sl);
-       }
-       spin_unlock(&sl->lock);
-}
-
-/* Encapsulate an IP datagram and kick it into a TTY queue. */
-
-static netdev_tx_t x25_asy_xmit(struct sk_buff *skb,
-                                     struct net_device *dev)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-       int err;
-
-       if (!netif_running(sl->dev)) {
-               netdev_err(dev, "xmit call when iface is down\n");
-               kfree_skb(skb);
-               return NETDEV_TX_OK;
-       }
-
-       /* There should be a pseudo header of 1 byte added by upper layers.
-        * Check to make sure it is there before reading it.
-        */
-       if (skb->len < 1) {
-               kfree_skb(skb);
-               return NETDEV_TX_OK;
-       }
-
-       switch (skb->data[0]) {
-       case X25_IFACE_DATA:
-               break;
-       case X25_IFACE_CONNECT: /* Connection request .. do nothing */
-               err = lapb_connect_request(dev);
-               if (err != LAPB_OK)
-                       netdev_err(dev, "lapb_connect_request error: %d\n",
-                                  err);
-               kfree_skb(skb);
-               return NETDEV_TX_OK;
-       case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */
-               err = lapb_disconnect_request(dev);
-               if (err != LAPB_OK)
-                       netdev_err(dev, "lapb_disconnect_request error: %d\n",
-                                  err);
-               fallthrough;
-       default:
-               kfree_skb(skb);
-               return NETDEV_TX_OK;
-       }
-       skb_pull(skb, 1);       /* Remove control byte */
-       /*
-        * If we are busy already- too bad.  We ought to be able
-        * to queue things at this point, to allow for a little
-        * frame buffer.  Oh well...
-        * -----------------------------------------------------
-        * I hate queues in X.25 driver. May be it's efficient,
-        * but for me latency is more important. ;)
-        * So, no queues !
-        *        14 Oct 1994  Dmitry Gorodchanin.
-        */
-
-       err = lapb_data_request(dev, skb);
-       if (err != LAPB_OK) {
-               netdev_err(dev, "lapb_data_request error: %d\n", err);
-               kfree_skb(skb);
-               return NETDEV_TX_OK;
-       }
-       return NETDEV_TX_OK;
-}
-
-
-/*
- *     LAPB interface boilerplate
- */
-
-/*
- *     Called when I frame data arrive. We add a pseudo header for upper
- *     layers and pass it to upper layers.
- */
-
-static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
-{
-       if (skb_cow(skb, 1)) {
-               kfree_skb(skb);
-               return NET_RX_DROP;
-       }
-       skb_push(skb, 1);
-       skb->data[0] = X25_IFACE_DATA;
-
-       skb->protocol = x25_type_trans(skb, dev);
-
-       return netif_rx(skb);
-}
-
-/*
- *     Data has emerged from the LAPB protocol machine. We don't handle
- *     busy cases too well. Its tricky to see how to do this nicely -
- *     perhaps lapb should allow us to bounce this ?
- */
-
-static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-
-       spin_lock(&sl->lock);
-       if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
-               spin_unlock(&sl->lock);
-               netdev_err(dev, "tbusy drop\n");
-               kfree_skb(skb);
-               return;
-       }
-       /* We were not busy, so we are now... :-) */
-       if (skb != NULL) {
-               x25_asy_lock(sl);
-               dev->stats.tx_bytes += skb->len;
-               x25_asy_encaps(sl, skb->data, skb->len);
-               dev_kfree_skb(skb);
-       }
-       spin_unlock(&sl->lock);
-}
-
-/*
- *     LAPB connection establish/down information.
- */
-
-static void x25_asy_connected(struct net_device *dev, int reason)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-       struct sk_buff *skb;
-       unsigned char *ptr;
-
-       skb = dev_alloc_skb(1);
-       if (skb == NULL) {
-               netdev_err(dev, "out of memory\n");
-               return;
-       }
-
-       ptr  = skb_put(skb, 1);
-       *ptr = X25_IFACE_CONNECT;
-
-       skb->protocol = x25_type_trans(skb, sl->dev);
-       netif_rx(skb);
-}
-
-static void x25_asy_disconnected(struct net_device *dev, int reason)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-       struct sk_buff *skb;
-       unsigned char *ptr;
-
-       skb = dev_alloc_skb(1);
-       if (skb == NULL) {
-               netdev_err(dev, "out of memory\n");
-               return;
-       }
-
-       ptr  = skb_put(skb, 1);
-       *ptr = X25_IFACE_DISCONNECT;
-
-       skb->protocol = x25_type_trans(skb, sl->dev);
-       netif_rx(skb);
-}
-
-static const struct lapb_register_struct x25_asy_callbacks = {
-       .connect_confirmation = x25_asy_connected,
-       .connect_indication = x25_asy_connected,
-       .disconnect_confirmation = x25_asy_disconnected,
-       .disconnect_indication = x25_asy_disconnected,
-       .data_indication = x25_asy_data_indication,
-       .data_transmit = x25_asy_data_transmit,
-};
-
-
-/* Open the low-level part of the X.25 channel. Easy! */
-static int x25_asy_open(struct net_device *dev)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-       unsigned long len;
-
-       if (sl->tty == NULL)
-               return -ENODEV;
-
-       /*
-        * Allocate the X.25 frame buffers:
-        *
-        * rbuff        Receive buffer.
-        * xbuff        Transmit buffer.
-        */
-
-       len = dev->mtu * 2;
-
-       sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
-       if (sl->rbuff == NULL)
-               goto norbuff;
-       sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
-       if (sl->xbuff == NULL)
-               goto noxbuff;
-
-       sl->buffsize = len;
-       sl->rcount   = 0;
-       sl->xleft    = 0;
-       sl->flags   &= (1 << SLF_INUSE);      /* Clear ESCAPE & ERROR flags */
-
-       return 0;
-
-       /* Cleanup */
-       kfree(sl->xbuff);
-       sl->xbuff = NULL;
-noxbuff:
-       kfree(sl->rbuff);
-       sl->rbuff = NULL;
-norbuff:
-       return -ENOMEM;
-}
-
-
-/* Close the low-level part of the X.25 channel. Easy! */
-static int x25_asy_close(struct net_device *dev)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-
-       spin_lock(&sl->lock);
-       if (sl->tty)
-               clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
-
-       sl->rcount = 0;
-       sl->xleft  = 0;
-       spin_unlock(&sl->lock);
-       return 0;
-}
-
-/*
- * Handle the 'receiver data ready' interrupt.
- * This function is called by the 'tty_io' module in the kernel when
- * a block of X.25 data has been received, which can now be decapsulated
- * and sent on to some IP layer for further processing.
- */
-
-static void x25_asy_receive_buf(struct tty_struct *tty,
-                               const unsigned char *cp, char *fp, int count)
-{
-       struct x25_asy *sl = tty->disc_data;
-
-       if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
-               return;
-
-
-       /* Read the characters out of the buffer */
-       while (count--) {
-               if (fp && *fp++) {
-                       if (!test_and_set_bit(SLF_ERROR, &sl->flags))
-                               sl->dev->stats.rx_errors++;
-                       cp++;
-                       continue;
-               }
-               x25_asy_unesc(sl, *cp++);
-       }
-}
-
-/*
- * Open the high-level part of the X.25 channel.
- * This function is called by the TTY module when the
- * X.25 line discipline is called for.  Because we are
- * sure the tty line exists, we only have to link it to
- * a free X.25 channel...
- */
-
-static int x25_asy_open_tty(struct tty_struct *tty)
-{
-       struct x25_asy *sl;
-       int err;
-
-       if (tty->ops->write == NULL)
-               return -EOPNOTSUPP;
-
-       /* OK.  Find a free X.25 channel to use. */
-       sl = x25_asy_alloc();
-       if (sl == NULL)
-               return -ENFILE;
-
-       sl->tty = tty;
-       tty->disc_data = sl;
-       tty->receive_room = 65536;
-       tty_driver_flush_buffer(tty);
-       tty_ldisc_flush(tty);
-
-       /* Restore default settings */
-       sl->dev->type = ARPHRD_X25;
-
-       /* Perform the low-level X.25 async init */
-       err = x25_asy_open(sl->dev);
-       if (err) {
-               x25_asy_free(sl);
-               return err;
-       }
-       /* Done.  We have linked the TTY line to a channel. */
-       return 0;
-}
-
-
-/*
- * Close down an X.25 channel.
- * This means flushing out any pending queues, and then restoring the
- * TTY line discipline to what it was before it got hooked to X.25
- * (which usually is TTY again).
- */
-static void x25_asy_close_tty(struct tty_struct *tty)
-{
-       struct x25_asy *sl = tty->disc_data;
-
-       /* First make sure we're connected. */
-       if (!sl || sl->magic != X25_ASY_MAGIC)
-               return;
-
-       rtnl_lock();
-       if (sl->dev->flags & IFF_UP)
-               dev_close(sl->dev);
-       rtnl_unlock();
-
-       tty->disc_data = NULL;
-       sl->tty = NULL;
-       x25_asy_free(sl);
-}
-
- /************************************************************************
-  *                    STANDARD X.25 ENCAPSULATION                      *
-  ************************************************************************/
-
-static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
-{
-       unsigned char *ptr = d;
-       unsigned char c;
-
-       /*
-        * Send an initial END character to flush out any
-        * data that may have accumulated in the receiver
-        * due to line noise.
-        */
-
-       *ptr++ = X25_END;       /* Send 10111110 bit seq */
-
-       /*
-        * For each byte in the packet, send the appropriate
-        * character sequence, according to the X.25 protocol.
-        */
-
-       while (len-- > 0) {
-               switch (c = *s++) {
-               case X25_END:
-                       *ptr++ = X25_ESC;
-                       *ptr++ = X25_ESCAPE(X25_END);
-                       break;
-               case X25_ESC:
-                       *ptr++ = X25_ESC;
-                       *ptr++ = X25_ESCAPE(X25_ESC);
-                       break;
-               default:
-                       *ptr++ = c;
-                       break;
-               }
-       }
-       *ptr++ = X25_END;
-       return ptr - d;
-}
-
-static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
-{
-
-       switch (s) {
-       case X25_END:
-               if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
-                   sl->rcount >= 2)
-                       x25_asy_bump(sl);
-               clear_bit(SLF_ESCAPE, &sl->flags);
-               sl->rcount = 0;
-               return;
-       case X25_ESC:
-               set_bit(SLF_ESCAPE, &sl->flags);
-               return;
-       case X25_ESCAPE(X25_ESC):
-       case X25_ESCAPE(X25_END):
-               if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
-                       s = X25_UNESCAPE(s);
-               break;
-       }
-       if (!test_bit(SLF_ERROR, &sl->flags)) {
-               if (sl->rcount < sl->buffsize) {
-                       sl->rbuff[sl->rcount++] = s;
-                       return;
-               }
-               sl->dev->stats.rx_over_errors++;
-               set_bit(SLF_ERROR, &sl->flags);
-       }
-}
-
-
-/* Perform I/O control on an active X.25 channel. */
-static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
-                        unsigned int cmd,  unsigned long arg)
-{
-       struct x25_asy *sl = tty->disc_data;
-
-       /* First make sure we're connected. */
-       if (!sl || sl->magic != X25_ASY_MAGIC)
-               return -EINVAL;
-
-       switch (cmd) {
-       case SIOCGIFNAME:
-               if (copy_to_user((void __user *)arg, sl->dev->name,
-                                       strlen(sl->dev->name) + 1))
-                       return -EFAULT;
-               return 0;
-       case SIOCSIFHWADDR:
-               return -EINVAL;
-       default:
-               return tty_mode_ioctl(tty, file, cmd, arg);
-       }
-}
-
-static int x25_asy_open_dev(struct net_device *dev)
-{
-       int err;
-       struct x25_asy *sl = netdev_priv(dev);
-       if (sl->tty == NULL)
-               return -ENODEV;
-
-       err = lapb_register(dev, &x25_asy_callbacks);
-       if (err != LAPB_OK)
-               return -ENOMEM;
-
-       netif_start_queue(dev);
-
-       return 0;
-}
-
-static int x25_asy_close_dev(struct net_device *dev)
-{
-       int err;
-
-       netif_stop_queue(dev);
-
-       err = lapb_unregister(dev);
-       if (err != LAPB_OK)
-               pr_err("%s: lapb_unregister error: %d\n",
-                      __func__, err);
-
-       x25_asy_close(dev);
-
-       return 0;
-}
-
-static const struct net_device_ops x25_asy_netdev_ops = {
-       .ndo_open       = x25_asy_open_dev,
-       .ndo_stop       = x25_asy_close_dev,
-       .ndo_start_xmit = x25_asy_xmit,
-       .ndo_tx_timeout = x25_asy_timeout,
-       .ndo_change_mtu = x25_asy_change_mtu,
-};
-
-/* Initialise the X.25 driver.  Called by the device init code */
-static void x25_asy_setup(struct net_device *dev)
-{
-       struct x25_asy *sl = netdev_priv(dev);
-
-       sl->magic  = X25_ASY_MAGIC;
-       sl->dev    = dev;
-       spin_lock_init(&sl->lock);
-       set_bit(SLF_INUSE, &sl->flags);
-
-       /*
-        *      Finish setting up the DEVICE info.
-        */
-
-       dev->mtu                = SL_MTU;
-       dev->min_mtu            = 0;
-       dev->max_mtu            = 65534;
-       dev->netdev_ops         = &x25_asy_netdev_ops;
-       dev->watchdog_timeo     = HZ*20;
-       dev->hard_header_len    = 0;
-       dev->addr_len           = 0;
-       dev->type               = ARPHRD_X25;
-       dev->tx_queue_len       = 10;
-
-       /* When transmitting data:
-        * first this driver removes a pseudo header of 1 byte,
-        * then the lapb module prepends an LAPB header of at most 3 bytes.
-        */
-       dev->needed_headroom    = 3 - 1;
-
-       /* New-style flags. */
-       dev->flags              = IFF_NOARP;
-}
-
-static struct tty_ldisc_ops x25_ldisc = {
-       .owner          = THIS_MODULE,
-       .magic          = TTY_LDISC_MAGIC,
-       .name           = "X.25",
-       .open           = x25_asy_open_tty,
-       .close          = x25_asy_close_tty,
-       .ioctl          = x25_asy_ioctl,
-       .receive_buf    = x25_asy_receive_buf,
-       .write_wakeup   = x25_asy_write_wakeup,
-};
-
-static int __init init_x25_asy(void)
-{
-       if (x25_asy_maxdev < 4)
-               x25_asy_maxdev = 4; /* Sanity */
-
-       pr_info("X.25 async: version 0.00 ALPHA (dynamic channels, max=%d)\n",
-               x25_asy_maxdev);
-
-       x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *),
-                               GFP_KERNEL);
-       if (!x25_asy_devs)
-               return -ENOMEM;
-
-       return tty_register_ldisc(N_X25, &x25_ldisc);
-}
-
-
-static void __exit exit_x25_asy(void)
-{
-       struct net_device *dev;
-       int i;
-
-       for (i = 0; i < x25_asy_maxdev; i++) {
-               dev = x25_asy_devs[i];
-               if (dev) {
-                       struct x25_asy *sl = netdev_priv(dev);
-
-                       spin_lock_bh(&sl->lock);
-                       if (sl->tty)
-                               tty_hangup(sl->tty);
-
-                       spin_unlock_bh(&sl->lock);
-                       /*
-                        * VSV = if dev->start==0, then device
-                        * unregistered while close proc.
-                        */
-                       unregister_netdev(dev);
-                       free_netdev(dev);
-               }
-       }
-
-       kfree(x25_asy_devs);
-       tty_unregister_ldisc(N_X25);
-}
-
-module_init(init_x25_asy);
-module_exit(exit_x25_asy);