| /* |
| * 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. |
| */ |
| |
| #include <linux/module.h> |
| |
| #include <asm/system.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/x25.h> |
| #include <linux/lapb.h> |
| #include <linux/init.h> |
| #include "x25_asy.h" |
| |
| #include <net/x25device.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 = dev->priv; |
| /* 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, x25_asy_setup); |
| if (!dev) |
| return NULL; |
| |
| /* Initialize channel control data */ |
| sl = dev->priv; |
| 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 { |
| printk(KERN_WARNING "x25_asy_alloc() - register_netdev() failure.\n"); |
| 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)) |
| printk(KERN_ERR "%s: x25_asy_free for already free unit.\n", |
| sl->dev->name); |
| } |
| |
| static int x25_asy_change_mtu(struct net_device *dev, int newmtu) |
| { |
| struct x25_asy *sl = dev->priv; |
| unsigned char *xbuff, *rbuff; |
| int len = 2 * newmtu; |
| |
| xbuff = kmalloc(len + 4, GFP_ATOMIC); |
| rbuff = kmalloc(len + 4, GFP_ATOMIC); |
| |
| if (xbuff == NULL || rbuff == NULL) { |
| printk(KERN_WARNING "%s: unable to grow X.25 buffers, MTU change cancelled.\n", |
| dev->name); |
| 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; |
| sl->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; |
| sl->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 one completely decapsulated IP datagram to the IP layer. */ |
| |
| static void x25_asy_bump(struct x25_asy *sl) |
| { |
| struct sk_buff *skb; |
| int count; |
| int err; |
| |
| count = sl->rcount; |
| sl->stats.rx_bytes += count; |
| |
| skb = dev_alloc_skb(count+1); |
| if (skb == NULL) { |
| printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", |
| sl->dev->name); |
| sl->stats.rx_dropped++; |
| return; |
| } |
| skb_push(skb, 1); /* LAPB internal control */ |
| memcpy(skb_put(skb, count), sl->rbuff, count); |
| skb->protocol = x25_type_trans(skb, sl->dev); |
| err = lapb_data_received(skb->dev, skb); |
| if (err != LAPB_OK) { |
| kfree_skb(skb); |
| printk(KERN_DEBUG "x25_asy: data received err - %d\n", err); |
| } else { |
| netif_rx(skb); |
| sl->dev->last_rx = jiffies; |
| sl->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->stats.tx_dropped++; |
| x25_asy_unlock(sl); |
| return; |
| } |
| |
| p = icp; |
| count = x25_asy_esc(p, (unsigned char *) 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. |
| */ |
| sl->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); |
| actual = sl->tty->ops->write(sl->tty, sl->xbuff, count); |
| sl->xleft = count - actual; |
| sl->xhead = sl->xbuff + actual; |
| /* VSV */ |
| clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ |
| } |
| |
| /* |
| * 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 = (struct x25_asy *) 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->stats.tx_packets++; |
| tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| 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) |
| { |
| struct x25_asy *sl = dev->priv; |
| |
| spin_lock(&sl->lock); |
| if (netif_queue_stopped(dev)) { |
| /* May be we must check transmitter timeout here ? |
| * 14 Oct 1994 Dmitry Gorodchanin. |
| */ |
| printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, |
| (tty_chars_in_buffer(sl->tty) || sl->xleft) ? |
| "bad line quality" : "driver error"); |
| sl->xleft = 0; |
| sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| x25_asy_unlock(sl); |
| } |
| spin_unlock(&sl->lock); |
| } |
| |
| /* Encapsulate an IP datagram and kick it into a TTY queue. */ |
| |
| static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct x25_asy *sl = dev->priv; |
| int err; |
| |
| if (!netif_running(sl->dev)) { |
| printk(KERN_ERR "%s: xmit call when iface is down\n", |
| dev->name); |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| switch (skb->data[0]) { |
| case 0x00: |
| break; |
| case 0x01: /* Connection request .. do nothing */ |
| err = lapb_connect_request(dev); |
| if (err != LAPB_OK) |
| printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err); |
| kfree_skb(skb); |
| return 0; |
| case 0x02: /* Disconnect request .. do nothing - hang up ?? */ |
| err = lapb_disconnect_request(dev); |
| if (err != LAPB_OK) |
| printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err); |
| default: |
| kfree_skb(skb); |
| return 0; |
| } |
| 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) { |
| printk(KERN_ERR "x25_asy: lapb_data_request error - %d\n", err); |
| kfree_skb(skb); |
| return 0; |
| } |
| return 0; |
| } |
| |
| |
| /* |
| * LAPB interface boilerplate |
| */ |
| |
| /* |
| * Called when I frame data arrives. We did the work above - throw it |
| * at the net layer. |
| */ |
| |
| static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) |
| { |
| skb->dev->last_rx = jiffies; |
| 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 = dev->priv; |
| |
| spin_lock(&sl->lock); |
| if (netif_queue_stopped(sl->dev) || sl->tty == NULL) { |
| spin_unlock(&sl->lock); |
| printk(KERN_ERR "x25_asy: tbusy drop\n"); |
| kfree_skb(skb); |
| return; |
| } |
| /* We were not busy, so we are now... :-) */ |
| if (skb != NULL) { |
| x25_asy_lock(sl); |
| sl->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 = dev->priv; |
| struct sk_buff *skb; |
| unsigned char *ptr; |
| |
| skb = dev_alloc_skb(1); |
| if (skb == NULL) { |
| printk(KERN_ERR "x25_asy: out of memory\n"); |
| return; |
| } |
| |
| ptr = skb_put(skb, 1); |
| *ptr = 0x01; |
| |
| skb->protocol = x25_type_trans(skb, sl->dev); |
| netif_rx(skb); |
| sl->dev->last_rx = jiffies; |
| } |
| |
| static void x25_asy_disconnected(struct net_device *dev, int reason) |
| { |
| struct x25_asy *sl = dev->priv; |
| struct sk_buff *skb; |
| unsigned char *ptr; |
| |
| skb = dev_alloc_skb(1); |
| if (skb == NULL) { |
| printk(KERN_ERR "x25_asy: out of memory\n"); |
| return; |
| } |
| |
| ptr = skb_put(skb, 1); |
| *ptr = 0x02; |
| |
| skb->protocol = x25_type_trans(skb, sl->dev); |
| netif_rx(skb); |
| sl->dev->last_rx = jiffies; |
| } |
| |
| static 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 = dev->priv; |
| unsigned long len; |
| int err; |
| |
| 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 */ |
| |
| netif_start_queue(dev); |
| |
| /* |
| * Now attach LAPB |
| */ |
| err = lapb_register(dev, &x25_asy_callbacks); |
| if (err == LAPB_OK) |
| return 0; |
| |
| /* Cleanup */ |
| kfree(sl->xbuff); |
| noxbuff: |
| kfree(sl->rbuff); |
| 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 = dev->priv; |
| int err; |
| |
| spin_lock(&sl->lock); |
| if (sl->tty) |
| sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| |
| netif_stop_queue(dev); |
| sl->rcount = 0; |
| sl->xleft = 0; |
| err = lapb_unregister(dev); |
| if (err != LAPB_OK) |
| printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n", |
| err); |
| 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 = (struct x25_asy *) 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->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 = (struct x25_asy *) tty->disc_data; |
| int err; |
| |
| if (tty->ops->write == NULL) |
| return -EOPNOTSUPP; |
| |
| /* First make sure we're not already connected. */ |
| if (sl && sl->magic == X25_ASY_MAGIC) |
| return -EEXIST; |
| |
| /* 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) |
| return err; |
| /* Done. We have linked the TTY line to a channel. */ |
| return sl->dev->base_addr; |
| } |
| |
| |
| /* |
| * 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 = (struct x25_asy *) tty->disc_data; |
| |
| /* First make sure we're connected. */ |
| if (!sl || sl->magic != X25_ASY_MAGIC) |
| return; |
| |
| if (sl->dev->flags & IFF_UP) |
| dev_close(sl->dev); |
| |
| tty->disc_data = NULL; |
| sl->tty = NULL; |
| x25_asy_free(sl); |
| } |
| |
| |
| static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) |
| { |
| struct x25_asy *sl = dev->priv; |
| return &sl->stats; |
| } |
| |
| |
| /************************************************************************ |
| * STANDARD X.25 ENCAPSULATION * |
| ************************************************************************/ |
| |
| 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->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 = (struct x25_asy *) 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) |
| { |
| struct x25_asy *sl = dev->priv; |
| if (sl->tty == NULL) |
| return -ENODEV; |
| return 0; |
| } |
| |
| /* Initialise the X.25 driver. Called by the device init code */ |
| static void x25_asy_setup(struct net_device *dev) |
| { |
| struct x25_asy *sl = dev->priv; |
| |
| 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->hard_start_xmit = x25_asy_xmit; |
| dev->tx_timeout = x25_asy_timeout; |
| dev->watchdog_timeo = HZ*20; |
| dev->open = x25_asy_open_dev; |
| dev->stop = x25_asy_close; |
| dev->get_stats = x25_asy_get_stats; |
| dev->change_mtu = x25_asy_change_mtu; |
| dev->hard_header_len = 0; |
| dev->addr_len = 0; |
| dev->type = ARPHRD_X25; |
| dev->tx_queue_len = 10; |
| |
| /* New-style flags. */ |
| dev->flags = IFF_NOARP; |
| } |
| |
| static struct tty_ldisc 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 */ |
| |
| printk(KERN_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) { |
| printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " |
| "array! Uaargh! (-> No X.25 available)\n"); |
| 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 = dev->priv; |
| |
| 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); |