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	 ca7335948e
			
		
	
	
		ca7335948e
		
	
	
	
	
		
			
			Remove duplicated #include('s) in drivers/net/wan/x25_asy.c
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
		
	
			
		
			
				
	
	
		
			829 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			829 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *	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/lapb.h>
 | |
| #include <linux/init.h>
 | |
| #include <linux/rtnetlink.h>
 | |
| #include <linux/compat.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, 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 {
 | |
| 			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 = netdev_priv(dev);
 | |
| 	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;
 | |
| 			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 one completely decapsulated IP datagram to the IP layer. */
 | |
| 
 | |
| 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+1);
 | |
| 	if (skb == NULL) {
 | |
| 		printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n",
 | |
| 			sl->dev->name);
 | |
| 		dev->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);
 | |
| 		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, (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.
 | |
| 	 */
 | |
| 	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;
 | |
| 	/* 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 = 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)
 | |
| {
 | |
| 	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.
 | |
| 		 */
 | |
| 		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;
 | |
| 		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)) {
 | |
| 		printk(KERN_ERR "%s: xmit call when iface is down\n",
 | |
| 			dev->name);
 | |
| 		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)
 | |
| 			printk(KERN_ERR "x25_asy: 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)
 | |
| 			printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err);
 | |
| 	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) {
 | |
| 		printk(KERN_ERR "x25_asy: 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 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)
 | |
| {
 | |
| 	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);
 | |
| 		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);
 | |
| 		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) {
 | |
| 		printk(KERN_ERR "x25_asy: 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) {
 | |
| 		printk(KERN_ERR "x25_asy: 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 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;
 | |
| 	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 = netdev_priv(dev);
 | |
| 	int err;
 | |
| 
 | |
| 	spin_lock(&sl->lock);
 | |
| 	if (sl->tty)
 | |
| 		clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
 | |
| 
 | |
| 	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 = 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 = 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 = 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);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| #ifdef CONFIG_COMPAT
 | |
| static long x25_asy_compat_ioctl(struct tty_struct *tty, struct file *file,
 | |
| 			 unsigned int cmd,  unsigned long arg)
 | |
| {
 | |
| 	switch (cmd) {
 | |
| 	case SIOCGIFNAME:
 | |
| 	case SIOCSIFHWADDR:
 | |
| 		return x25_asy_ioctl(tty, file, cmd,
 | |
| 				     (unsigned long)compat_ptr(arg));
 | |
| 	}
 | |
| 
 | |
| 	return -ENOIOCTLCMD;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| static int x25_asy_open_dev(struct net_device *dev)
 | |
| {
 | |
| 	struct x25_asy *sl = netdev_priv(dev);
 | |
| 	if (sl->tty == NULL)
 | |
| 		return -ENODEV;
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static const struct net_device_ops x25_asy_netdev_ops = {
 | |
| 	.ndo_open	= x25_asy_open_dev,
 | |
| 	.ndo_stop	= x25_asy_close,
 | |
| 	.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->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;
 | |
| 
 | |
| 	/* 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,
 | |
| #ifdef CONFIG_COMPAT
 | |
| 	.compat_ioctl	= x25_asy_compat_ioctl,
 | |
| #endif
 | |
| 	.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 = 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);
 |