/* $Id: isdn_net.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
 *
 * Linux ISDN subsystem, network interfaces and related functions (linklevel).
 *
 * Copyright 1994-1998  by Fritz Elfert (fritz@isdn4linux.de)
 * Copyright 1995,96    by 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.
 *
 * Data Over Voice (DOV) support added - Guy Ellis 23-Mar-02 
 *                                       guy@traverse.com.au
 * Outgoing calls - looks for a 'V' in first char of dialed number
 * Incoming calls - checks first character of eaz as follows:
 *   Numeric - accept DATA only - original functionality
 *   'V'     - accept VOICE (DOV) only
 *   'B'     - accept BOTH DATA and DOV types
 *
 * Jan 2001: fix CISCO HDLC      Bjoern A. Zeeb <i4l@zabbadoz.net>
 *           for info on the protocol, see 
 *           http://i4l.zabbadoz.net/i4l/cisco-hdlc.txt
 */

#include <linux/isdn.h>
#include <linux/slab.h>
#include <net/arp.h>
#include <net/dst.h>
#include <net/pkt_sched.h>
#include <linux/inetdevice.h>
#include "isdn_common.h"
#include "isdn_net.h"
#ifdef CONFIG_ISDN_PPP
#include "isdn_ppp.h"
#endif
#ifdef CONFIG_ISDN_X25
#include <linux/concap.h>
#include "isdn_concap.h"
#endif


/*
 * Outline of new tbusy handling: 
 *
 * Old method, roughly spoken, consisted of setting tbusy when entering
 * isdn_net_start_xmit() and at several other locations and clearing
 * it from isdn_net_start_xmit() thread when sending was successful.
 *
 * With 2.3.x multithreaded network core, to prevent problems, tbusy should
 * only be set by the isdn_net_start_xmit() thread and only when a tx-busy
 * condition is detected. Other threads (in particular isdn_net_stat_callb())
 * are only allowed to clear tbusy.
 *
 * -HE
 */

/*
 * About SOFTNET:
 * Most of the changes were pretty obvious and basically done by HE already.
 *
 * One problem of the isdn net device code is that is uses struct net_device
 * for masters and slaves. However, only master interface are registered to 
 * the network layer, and therefore, it only makes sense to call netif_* 
 * functions on them.
 *
 * --KG
 */

/* 
 * Find out if the netdevice has been ifup-ed yet.
 * For slaves, look at the corresponding master.
 */
static __inline__ int isdn_net_device_started(isdn_net_dev *n)
{
	isdn_net_local *lp = n->local;
	struct net_device *dev;
	
	if (lp->master) 
		dev = lp->master;
	else
		dev = n->dev;
	return netif_running(dev);
}

/*
 * wake up the network -> net_device queue.
 * For slaves, wake the corresponding master interface.
 */
static __inline__ void isdn_net_device_wake_queue(isdn_net_local *lp)
{
	if (lp->master) 
		netif_wake_queue(lp->master);
	else
		netif_wake_queue(lp->netdev->dev);
}

/*
 * stop the network -> net_device queue.
 * For slaves, stop the corresponding master interface.
 */
static __inline__ void isdn_net_device_stop_queue(isdn_net_local *lp)
{
	if (lp->master)
		netif_stop_queue(lp->master);
	else
		netif_stop_queue(lp->netdev->dev);
}

/*
 * find out if the net_device which this lp belongs to (lp can be
 * master or slave) is busy. It's busy iff all (master and slave) 
 * queues are busy
 */
static __inline__ int isdn_net_device_busy(isdn_net_local *lp)
{
	isdn_net_local *nlp;
	isdn_net_dev *nd;
	unsigned long flags;

	if (!isdn_net_lp_busy(lp))
		return 0;

	if (lp->master)
		nd = ISDN_MASTER_PRIV(lp)->netdev;
	else
		nd = lp->netdev;
	
	spin_lock_irqsave(&nd->queue_lock, flags);
	nlp = lp->next;
	while (nlp != lp) {
		if (!isdn_net_lp_busy(nlp)) {
			spin_unlock_irqrestore(&nd->queue_lock, flags);
			return 0;
		}
		nlp = nlp->next;
	}
	spin_unlock_irqrestore(&nd->queue_lock, flags);
	return 1;
}

static __inline__ void isdn_net_inc_frame_cnt(isdn_net_local *lp)
{
	atomic_inc(&lp->frame_cnt);
	if (isdn_net_device_busy(lp))
		isdn_net_device_stop_queue(lp);
}

static __inline__ void isdn_net_dec_frame_cnt(isdn_net_local *lp)
{
	atomic_dec(&lp->frame_cnt);

	if (!(isdn_net_device_busy(lp))) {
		if (!skb_queue_empty(&lp->super_tx_queue)) {
			schedule_work(&lp->tqueue);
		} else {
			isdn_net_device_wake_queue(lp);
		}
       }                                                                      
}

static __inline__ void isdn_net_zero_frame_cnt(isdn_net_local *lp)
{
	atomic_set(&lp->frame_cnt, 0);
}

/* For 2.2.x we leave the transmitter busy timeout at 2 secs, just 
 * to be safe.
 * For 2.3.x we push it up to 20 secs, because call establishment
 * (in particular callback) may take such a long time, and we 
 * don't want confusing messages in the log. However, there is a slight
 * possibility that this large timeout will break other things like MPPP,
 * which might rely on the tx timeout. If so, we'll find out this way...
 */

#define ISDN_NET_TX_TIMEOUT (20*HZ) 

/* Prototypes */

static int isdn_net_force_dial_lp(isdn_net_local *);
static netdev_tx_t isdn_net_start_xmit(struct sk_buff *,
					     struct net_device *);

static void isdn_net_ciscohdlck_connected(isdn_net_local *lp);
static void isdn_net_ciscohdlck_disconnected(isdn_net_local *lp);

char *isdn_net_revision = "$Revision: 1.1.2.2 $";

 /*
  * Code for raw-networking over ISDN
  */

static void
isdn_net_unreachable(struct net_device *dev, struct sk_buff *skb, char *reason)
{
	if(skb) {

		u_short proto = ntohs(skb->protocol);

		printk(KERN_DEBUG "isdn_net: %s: %s, signalling dst_link_failure %s\n",
		       dev->name,
		       (reason != NULL) ? reason : "unknown",
		       (proto != ETH_P_IP) ? "Protocol != ETH_P_IP" : "");
		
		dst_link_failure(skb);
	}
	else {  /* dial not triggered by rawIP packet */
		printk(KERN_DEBUG "isdn_net: %s: %s\n",
			   dev->name,
			   (reason != NULL) ? reason : "reason unknown");
	}
}

static void
isdn_net_reset(struct net_device *dev)
{
#ifdef CONFIG_ISDN_X25
	struct concap_device_ops * dops =
		((isdn_net_local *) netdev_priv(dev))->dops;
	struct concap_proto * cprot =
		((isdn_net_local *) netdev_priv(dev))->netdev->cprot;
#endif
#ifdef CONFIG_ISDN_X25
	if( cprot && cprot -> pops && dops )
		cprot -> pops -> restart ( cprot, dev, dops );
#endif
}

/* Open/initialize the board. */
static int
isdn_net_open(struct net_device *dev)
{
	int i;
	struct net_device *p;
	struct in_device *in_dev;

	/* moved here from isdn_net_reset, because only the master has an
	   interface associated which is supposed to be started. BTW:
	   we need to call netif_start_queue, not netif_wake_queue here */
	netif_start_queue(dev);

	isdn_net_reset(dev);
	/* Fill in the MAC-level header (not needed, but for compatibility... */
	for (i = 0; i < ETH_ALEN - sizeof(u32); i++)
		dev->dev_addr[i] = 0xfc;
	if ((in_dev = dev->ip_ptr) != NULL) {
		/*
		 *      Any address will do - we take the first
		 */
		struct in_ifaddr *ifa = in_dev->ifa_list;
		if (ifa != NULL)
			memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
	}

	/* If this interface has slaves, start them also */
	p = MASTER_TO_SLAVE(dev);
	if (p) {
		while (p) {
			isdn_net_reset(p);
			p = MASTER_TO_SLAVE(p);
		}
	}
	isdn_lock_drivers();
	return 0;
}

/*
 * Assign an ISDN-channel to a net-interface
 */
static void
isdn_net_bind_channel(isdn_net_local * lp, int idx)
{
	lp->flags |= ISDN_NET_CONNECTED;
	lp->isdn_device = dev->drvmap[idx];
	lp->isdn_channel = dev->chanmap[idx];
	dev->rx_netdev[idx] = lp->netdev;
	dev->st_netdev[idx] = lp->netdev;
}

/*
 * unbind a net-interface (resets interface after an error)
 */
static void
isdn_net_unbind_channel(isdn_net_local * lp)
{
	skb_queue_purge(&lp->super_tx_queue);

	if (!lp->master) {	/* reset only master device */
		/* Moral equivalent of dev_purge_queues():
		   BEWARE! This chunk of code cannot be called from hardware
		   interrupt handler. I hope it is true. --ANK
		 */
		qdisc_reset_all_tx(lp->netdev->dev);
	}
	lp->dialstate = 0;
	dev->rx_netdev[isdn_dc2minor(lp->isdn_device, lp->isdn_channel)] = NULL;
	dev->st_netdev[isdn_dc2minor(lp->isdn_device, lp->isdn_channel)] = NULL;
	if (lp->isdn_device != -1 && lp->isdn_channel != -1)
		isdn_free_channel(lp->isdn_device, lp->isdn_channel,
				  ISDN_USAGE_NET);
	lp->flags &= ~ISDN_NET_CONNECTED;
	lp->isdn_device = -1;
	lp->isdn_channel = -1;
}

/*
 * Perform auto-hangup and cps-calculation for net-interfaces.
 *
 * auto-hangup:
 * Increment idle-counter (this counter is reset on any incoming or
 * outgoing packet), if counter exceeds configured limit either do a
 * hangup immediately or - if configured - wait until just before the next
 * charge-info.
 *
 * cps-calculation (needed for dynamic channel-bundling):
 * Since this function is called every second, simply reset the
 * byte-counter of the interface after copying it to the cps-variable.
 */
static unsigned long last_jiffies = -HZ;

void
isdn_net_autohup(void)
{
	isdn_net_dev *p = dev->netdev;
	int anymore;

	anymore = 0;
	while (p) {
		isdn_net_local *l = p->local;
		if (jiffies == last_jiffies)
			l->cps = l->transcount;
		else
			l->cps = (l->transcount * HZ) / (jiffies - last_jiffies);
		l->transcount = 0;
		if (dev->net_verbose > 3)
			printk(KERN_DEBUG "%s: %d bogocps\n", p->dev->name, l->cps);
		if ((l->flags & ISDN_NET_CONNECTED) && (!l->dialstate)) {
			anymore = 1;
			l->huptimer++;
			/*
			 * if there is some dialmode where timeout-hangup
			 * should _not_ be done, check for that here
			 */
			if ((l->onhtime) &&
			    (l->huptimer > l->onhtime))
			{
				if (l->hupflags & ISDN_MANCHARGE &&
				    l->hupflags & ISDN_CHARGEHUP) {
					while (time_after(jiffies, l->chargetime + l->chargeint))
						l->chargetime += l->chargeint;
					if (time_after(jiffies, l->chargetime + l->chargeint - 2 * HZ))
						if (l->outgoing || l->hupflags & ISDN_INHUP)
							isdn_net_hangup(p->dev);
				} else if (l->outgoing) {
					if (l->hupflags & ISDN_CHARGEHUP) {
						if (l->hupflags & ISDN_WAITCHARGE) {
							printk(KERN_DEBUG "isdn_net: Hupflags of %s are %X\n",
							       p->dev->name, l->hupflags);
							isdn_net_hangup(p->dev);
						} else if (time_after(jiffies, l->chargetime + l->chargeint)) {
							printk(KERN_DEBUG
							       "isdn_net: %s: chtime = %lu, chint = %d\n",
							       p->dev->name, l->chargetime, l->chargeint);
							isdn_net_hangup(p->dev);
						}
					} else
						isdn_net_hangup(p->dev);
				} else if (l->hupflags & ISDN_INHUP)
					isdn_net_hangup(p->dev);
			}

			if(dev->global_flags & ISDN_GLOBAL_STOPPED || (ISDN_NET_DIALMODE(*l) == ISDN_NET_DM_OFF)) {
				isdn_net_hangup(p->dev);
				break;
			}
		}
		p = (isdn_net_dev *) p->next;
	}
	last_jiffies = jiffies;
	isdn_timer_ctrl(ISDN_TIMER_NETHANGUP, anymore);
}

static void isdn_net_lp_disconnected(isdn_net_local *lp)
{
	isdn_net_rm_from_bundle(lp);
}

/*
 * Handle status-messages from ISDN-interfacecard.
 * This function is called from within the main-status-dispatcher
 * isdn_status_callback, which itself is called from the low-level driver.
 * Return: 1 = Event handled, 0 = not for us or unknown Event.
 */
int
isdn_net_stat_callback(int idx, isdn_ctrl *c)
{
	isdn_net_dev *p = dev->st_netdev[idx];
	int cmd = c->command;

	if (p) {
		isdn_net_local *lp = p->local;
#ifdef CONFIG_ISDN_X25
		struct concap_proto *cprot = lp->netdev->cprot;
		struct concap_proto_ops *pops = cprot ? cprot->pops : NULL;
#endif
		switch (cmd) {
			case ISDN_STAT_BSENT:
				/* A packet has successfully been sent out */
				if ((lp->flags & ISDN_NET_CONNECTED) &&
				    (!lp->dialstate)) {
					isdn_net_dec_frame_cnt(lp);
					lp->stats.tx_packets++;
					lp->stats.tx_bytes += c->parm.length;
				}
				return 1;
			case ISDN_STAT_DCONN:
				/* D-Channel is up */
				switch (lp->dialstate) {
					case 4:
					case 7:
					case 8:
						lp->dialstate++;
						return 1;
					case 12:
						lp->dialstate = 5;
						return 1;
				}
				break;
			case ISDN_STAT_DHUP:
				/* Either D-Channel-hangup or error during dialout */
#ifdef CONFIG_ISDN_X25
				/* If we are not connencted then dialing had
				   failed. If there are generic encap protocol
				   receiver routines signal the closure of
				   the link*/

				if( !(lp->flags & ISDN_NET_CONNECTED)
				    && pops && pops -> disconn_ind )
					pops -> disconn_ind(cprot);
#endif /* CONFIG_ISDN_X25 */
				if ((!lp->dialstate) && (lp->flags & ISDN_NET_CONNECTED)) {
					if (lp->p_encap == ISDN_NET_ENCAP_CISCOHDLCK)
						isdn_net_ciscohdlck_disconnected(lp);
#ifdef CONFIG_ISDN_PPP
					if (lp->p_encap == ISDN_NET_ENCAP_SYNCPPP)
						isdn_ppp_free(lp);
#endif
					isdn_net_lp_disconnected(lp);
					isdn_all_eaz(lp->isdn_device, lp->isdn_channel);
					printk(KERN_INFO "%s: remote hangup\n", p->dev->name);
					printk(KERN_INFO "%s: Chargesum is %d\n", p->dev->name,
					       lp->charge);
					isdn_net_unbind_channel(lp);
					return 1;
				}
				break;
#ifdef CONFIG_ISDN_X25
			case ISDN_STAT_BHUP:
				/* B-Channel-hangup */
				/* try if there are generic encap protocol
				   receiver routines and signal the closure of
				   the link */
				if( pops  &&  pops -> disconn_ind ){
						pops -> disconn_ind(cprot);
						return 1;
					}
				break;
#endif /* CONFIG_ISDN_X25 */
			case ISDN_STAT_BCONN:
				/* B-Channel is up */
				isdn_net_zero_frame_cnt(lp);
				switch (lp->dialstate) {
					case 5:
					case 6:
					case 7:
					case 8:
					case 9:
					case 10:
					case 12:
						if (lp->dialstate <= 6) {
							dev->usage[idx] |= ISDN_USAGE_OUTGOING;
							isdn_info_update();
						} else
							dev->rx_netdev[idx] = p;
						lp->dialstate = 0;
						isdn_timer_ctrl(ISDN_TIMER_NETHANGUP, 1);
						if (lp->p_encap == ISDN_NET_ENCAP_CISCOHDLCK)
							isdn_net_ciscohdlck_connected(lp);
						if (lp->p_encap != ISDN_NET_ENCAP_SYNCPPP) {
							if (lp->master) { /* is lp a slave? */
								isdn_net_dev *nd = ISDN_MASTER_PRIV(lp)->netdev;
								isdn_net_add_to_bundle(nd, lp);
							}
						}
						printk(KERN_INFO "isdn_net: %s connected\n", p->dev->name);
						/* If first Chargeinfo comes before B-Channel connect,
						 * we correct the timestamp here.
						 */
						lp->chargetime = jiffies;

						/* reset dial-timeout */
						lp->dialstarted = 0;
						lp->dialwait_timer = 0;

#ifdef CONFIG_ISDN_PPP
						if (lp->p_encap == ISDN_NET_ENCAP_SYNCPPP)
							isdn_ppp_wakeup_daemon(lp);
#endif
#ifdef CONFIG_ISDN_X25
						/* try if there are generic concap receiver routines */
						if( pops )
							if( pops->connect_ind)
								pops->connect_ind(cprot);
#endif /* CONFIG_ISDN_X25 */
						/* ppp needs to do negotiations first */
						if (lp->p_encap != ISDN_NET_ENCAP_SYNCPPP)
							isdn_net_device_wake_queue(lp);
						return 1;
				}
				break;
			case ISDN_STAT_NODCH:
				/* No D-Channel avail. */
				if (lp->dialstate == 4) {
					lp->dialstate--;
					return 1;
				}
				break;
			case ISDN_STAT_CINF:
				/* Charge-info from TelCo. Calculate interval between
				 * charge-infos and set timestamp for last info for
				 * usage by isdn_net_autohup()
				 */
				lp->charge++;
				if (lp->hupflags & ISDN_HAVECHARGE) {
					lp->hupflags &= ~ISDN_WAITCHARGE;
					lp->chargeint = jiffies - lp->chargetime - (2 * HZ);
				}
				if (lp->hupflags & ISDN_WAITCHARGE)
					lp->hupflags |= ISDN_HAVECHARGE;
				lp->chargetime = jiffies;
				printk(KERN_DEBUG "isdn_net: Got CINF chargetime of %s now %lu\n",
				       p->dev->name, lp->chargetime);
				return 1;
		}
	}
	return 0;
}

/*
 * Perform dialout for net-interfaces and timeout-handling for
 * D-Channel-up and B-Channel-up Messages.
 * This function is initially called from within isdn_net_start_xmit() or
 * or isdn_net_find_icall() after initializing the dialstate for an
 * interface. If further calls are needed, the function schedules itself
 * for a timer-callback via isdn_timer_function().
 * The dialstate is also affected by incoming status-messages from
 * the ISDN-Channel which are handled in isdn_net_stat_callback() above.
 */
void
isdn_net_dial(void)
{
	isdn_net_dev *p = dev->netdev;
	int anymore = 0;
	int i;
	isdn_ctrl cmd;
        u_char *phone_number;

	while (p) {
		isdn_net_local *lp = p->local;

#ifdef ISDN_DEBUG_NET_DIAL
		if (lp->dialstate)
			printk(KERN_DEBUG "%s: dialstate=%d\n", p->dev->name, lp->dialstate);
#endif
		switch (lp->dialstate) {
			case 0:
				/* Nothing to do for this interface */
				break;
			case 1:
				/* Initiate dialout. Set phone-number-pointer to first number
				 * of interface.
				 */
				lp->dial = lp->phone[1];
				if (!lp->dial) {
					printk(KERN_WARNING "%s: phone number deleted?\n",
					       p->dev->name);
					isdn_net_hangup(p->dev);
					break;
				}
				anymore = 1;

				if(lp->dialtimeout > 0)
					if(lp->dialstarted == 0 || time_after(jiffies, lp->dialstarted + lp->dialtimeout + lp->dialwait)) {
						lp->dialstarted = jiffies;
						lp->dialwait_timer = 0;
					}

				lp->dialstate++;
				/* Fall through */
			case 2:
				/* Prepare dialing. Clear EAZ, then set EAZ. */
				cmd.driver = lp->isdn_device;
				cmd.arg = lp->isdn_channel;
				cmd.command = ISDN_CMD_CLREAZ;
				isdn_command(&cmd);
				sprintf(cmd.parm.num, "%s", isdn_map_eaz2msn(lp->msn, cmd.driver));
				cmd.command = ISDN_CMD_SETEAZ;
				isdn_command(&cmd);
				lp->dialretry = 0;
				anymore = 1;
				lp->dialstate++;
				/* Fall through */
			case 3:
				/* Setup interface, dial current phone-number, switch to next number.
				 * If list of phone-numbers is exhausted, increment
				 * retry-counter.
				 */
				if(dev->global_flags & ISDN_GLOBAL_STOPPED || (ISDN_NET_DIALMODE(*lp) == ISDN_NET_DM_OFF)) {
					char *s;
					if (dev->global_flags & ISDN_GLOBAL_STOPPED)
						s = "dial suppressed: isdn system stopped";
					else
						s = "dial suppressed: dialmode `off'";
					isdn_net_unreachable(p->dev, NULL, s);
					isdn_net_hangup(p->dev);
					break;
				}
				cmd.driver = lp->isdn_device;
				cmd.command = ISDN_CMD_SETL2;
				cmd.arg = lp->isdn_channel + (lp->l2_proto << 8);
				isdn_command(&cmd);
				cmd.driver = lp->isdn_device;
				cmd.command = ISDN_CMD_SETL3;
				cmd.arg = lp->isdn_channel + (lp->l3_proto << 8);
				isdn_command(&cmd);
				cmd.driver = lp->isdn_device;
				cmd.arg = lp->isdn_channel;
				if (!lp->dial) {
					printk(KERN_WARNING "%s: phone number deleted?\n",
					       p->dev->name);
					isdn_net_hangup(p->dev);
					break;
				}
				if (!strncmp(lp->dial->num, "LEASED", strlen("LEASED"))) {
					lp->dialstate = 4;
					printk(KERN_INFO "%s: Open leased line ...\n", p->dev->name);
				} else {
					if(lp->dialtimeout > 0)
						if (time_after(jiffies, lp->dialstarted + lp->dialtimeout)) {
							lp->dialwait_timer = jiffies + lp->dialwait;
							lp->dialstarted = 0;
							isdn_net_unreachable(p->dev, NULL, "dial: timed out");
							isdn_net_hangup(p->dev);
							break;
						}

					cmd.driver = lp->isdn_device;
					cmd.command = ISDN_CMD_DIAL;
					cmd.parm.setup.si2 = 0;

                                        /* check for DOV */
                                        phone_number = lp->dial->num;
                                        if ((*phone_number == 'v') ||
					    (*phone_number == 'V')) { /* DOV call */
                                                cmd.parm.setup.si1 = 1;
                                        } else { /* DATA call */
                                                cmd.parm.setup.si1 = 7;
					}

					strcpy(cmd.parm.setup.phone, phone_number);
					/*
					 * Switch to next number or back to start if at end of list.
					 */
					if (!(lp->dial = (isdn_net_phone *) lp->dial->next)) {
						lp->dial = lp->phone[1];
						lp->dialretry++;

						if (lp->dialretry > lp->dialmax) {
							if (lp->dialtimeout == 0) {
								lp->dialwait_timer = jiffies + lp->dialwait;
								lp->dialstarted = 0;
								isdn_net_unreachable(p->dev, NULL, "dial: tried all numbers dialmax times");
							}
							isdn_net_hangup(p->dev);
							break;
						}
					}
					sprintf(cmd.parm.setup.eazmsn, "%s",
						isdn_map_eaz2msn(lp->msn, cmd.driver));
					i = isdn_dc2minor(lp->isdn_device, lp->isdn_channel);
					if (i >= 0) {
						strcpy(dev->num[i], cmd.parm.setup.phone);
						dev->usage[i] |= ISDN_USAGE_OUTGOING;
						isdn_info_update();
					}
					printk(KERN_INFO "%s: dialing %d %s... %s\n", p->dev->name,
					       lp->dialretry, cmd.parm.setup.phone,
					       (cmd.parm.setup.si1 == 1) ? "DOV" : "");
					lp->dtimer = 0;
#ifdef ISDN_DEBUG_NET_DIAL
					printk(KERN_DEBUG "dial: d=%d c=%d\n", lp->isdn_device,
					       lp->isdn_channel);
#endif
					isdn_command(&cmd);
				}
				lp->huptimer = 0;
				lp->outgoing = 1;
				if (lp->chargeint) {
					lp->hupflags |= ISDN_HAVECHARGE;
					lp->hupflags &= ~ISDN_WAITCHARGE;
				} else {
					lp->hupflags |= ISDN_WAITCHARGE;
					lp->hupflags &= ~ISDN_HAVECHARGE;
				}
				anymore = 1;
				lp->dialstate =
				    (lp->cbdelay &&
				     (lp->flags & ISDN_NET_CBOUT)) ? 12 : 4;
				break;
			case 4:
				/* Wait for D-Channel-connect.
				 * If timeout, switch back to state 3.
				 * Dialmax-handling moved to state 3.
				 */
				if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
					lp->dialstate = 3;
				anymore = 1;
				break;
			case 5:
				/* Got D-Channel-Connect, send B-Channel-request */
				cmd.driver = lp->isdn_device;
				cmd.arg = lp->isdn_channel;
				cmd.command = ISDN_CMD_ACCEPTB;
				anymore = 1;
				lp->dtimer = 0;
				lp->dialstate++;
				isdn_command(&cmd);
				break;
			case 6:
				/* Wait for B- or D-Channel-connect. If timeout,
				 * switch back to state 3.
				 */
#ifdef ISDN_DEBUG_NET_DIAL
				printk(KERN_DEBUG "dialtimer2: %d\n", lp->dtimer);
#endif
				if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
					lp->dialstate = 3;
				anymore = 1;
				break;
			case 7:
				/* Got incoming Call, setup L2 and L3 protocols,
				 * then wait for D-Channel-connect
				 */
#ifdef ISDN_DEBUG_NET_DIAL
				printk(KERN_DEBUG "dialtimer4: %d\n", lp->dtimer);
#endif
				cmd.driver = lp->isdn_device;
				cmd.command = ISDN_CMD_SETL2;
				cmd.arg = lp->isdn_channel + (lp->l2_proto << 8);
				isdn_command(&cmd);
				cmd.driver = lp->isdn_device;
				cmd.command = ISDN_CMD_SETL3;
				cmd.arg = lp->isdn_channel + (lp->l3_proto << 8);
				isdn_command(&cmd);
				if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT15)
					isdn_net_hangup(p->dev);
				else {
					anymore = 1;
					lp->dialstate++;
				}
				break;
			case 9:
				/* Got incoming D-Channel-Connect, send B-Channel-request */
				cmd.driver = lp->isdn_device;
				cmd.arg = lp->isdn_channel;
				cmd.command = ISDN_CMD_ACCEPTB;
				isdn_command(&cmd);
				anymore = 1;
				lp->dtimer = 0;
				lp->dialstate++;
				break;
			case 8:
			case 10:
				/*  Wait for B- or D-channel-connect */
#ifdef ISDN_DEBUG_NET_DIAL
				printk(KERN_DEBUG "dialtimer4: %d\n", lp->dtimer);
#endif
				if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
					isdn_net_hangup(p->dev);
				else
					anymore = 1;
				break;
			case 11:
				/* Callback Delay */
				if (lp->dtimer++ > lp->cbdelay)
					lp->dialstate = 1;
				anymore = 1;
				break;
			case 12:
				/* Remote does callback. Hangup after cbdelay, then wait for incoming
				 * call (in state 4).
				 */
				if (lp->dtimer++ > lp->cbdelay)
				{
					printk(KERN_INFO "%s: hangup waiting for callback ...\n", p->dev->name);
					lp->dtimer = 0;
					lp->dialstate = 4;
					cmd.driver = lp->isdn_device;
					cmd.command = ISDN_CMD_HANGUP;
					cmd.arg = lp->isdn_channel;
					isdn_command(&cmd);
					isdn_all_eaz(lp->isdn_device, lp->isdn_channel);
				}
				anymore = 1;
				break;
			default:
				printk(KERN_WARNING "isdn_net: Illegal dialstate %d for device %s\n",
				       lp->dialstate, p->dev->name);
		}
		p = (isdn_net_dev *) p->next;
	}
	isdn_timer_ctrl(ISDN_TIMER_NETDIAL, anymore);
}

/*
 * Perform hangup for a net-interface.
 */
void
isdn_net_hangup(struct net_device *d)
{
	isdn_net_local *lp = netdev_priv(d);
	isdn_ctrl cmd;
#ifdef CONFIG_ISDN_X25
	struct concap_proto *cprot = lp->netdev->cprot;
	struct concap_proto_ops *pops = cprot ? cprot->pops : NULL;
#endif

	if (lp->flags & ISDN_NET_CONNECTED) {
		if (lp->slave != NULL) {
			isdn_net_local *slp = ISDN_SLAVE_PRIV(lp);
			if (slp->flags & ISDN_NET_CONNECTED) {
				printk(KERN_INFO
					"isdn_net: hang up slave %s before %s\n",
					lp->slave->name, d->name);
				isdn_net_hangup(lp->slave);
			}
		}
		printk(KERN_INFO "isdn_net: local hangup %s\n", d->name);
#ifdef CONFIG_ISDN_PPP
		if (lp->p_encap == ISDN_NET_ENCAP_SYNCPPP)
			isdn_ppp_free(lp);
#endif
		isdn_net_lp_disconnected(lp);
#ifdef CONFIG_ISDN_X25
		/* try if there are generic encap protocol
		   receiver routines and signal the closure of
		   the link */
		if( pops && pops -> disconn_ind )
		  pops -> disconn_ind(cprot);
#endif /* CONFIG_ISDN_X25 */

		cmd.driver = lp->isdn_device;
		cmd.command = ISDN_CMD_HANGUP;
		cmd.arg = lp->isdn_channel;
		isdn_command(&cmd);
		printk(KERN_INFO "%s: Chargesum is %d\n", d->name, lp->charge);
		isdn_all_eaz(lp->isdn_device, lp->isdn_channel);
	}
	isdn_net_unbind_channel(lp);
}

typedef struct {
	__be16 source;
	__be16 dest;
} ip_ports;

static void
isdn_net_log_skb(struct sk_buff * skb, isdn_net_local * lp)
{
	/* hopefully, this was set correctly */
	const u_char *p = skb_network_header(skb);
	unsigned short proto = ntohs(skb->protocol);
	int data_ofs;
	ip_ports *ipp;
	char addinfo[100];

	addinfo[0] = '\0';
	/* This check stolen from 2.1.72 dev_queue_xmit_nit() */
	if (p < skb->data || skb->network_header >= skb->tail) {
		/* fall back to old isdn_net_log_packet method() */
		char * buf = skb->data;

		printk(KERN_DEBUG "isdn_net: protocol %04x is buggy, dev %s\n", skb->protocol, lp->netdev->dev->name);
		p = buf;
		proto = ETH_P_IP;
		switch (lp->p_encap) {
			case ISDN_NET_ENCAP_IPTYP:
				proto = ntohs(*(__be16 *)&buf[0]);
				p = &buf[2];
				break;
			case ISDN_NET_ENCAP_ETHER:
				proto = ntohs(*(__be16 *)&buf[12]);
				p = &buf[14];
				break;
			case ISDN_NET_ENCAP_CISCOHDLC:
				proto = ntohs(*(__be16 *)&buf[2]);
				p = &buf[4];
				break;
#ifdef CONFIG_ISDN_PPP
			case ISDN_NET_ENCAP_SYNCPPP:
				proto = ntohs(skb->protocol);
				p = &buf[IPPP_MAX_HEADER];
				break;
#endif
		}
	}
	data_ofs = ((p[0] & 15) * 4);
	switch (proto) {
		case ETH_P_IP:
			switch (p[9]) {
				case 1:
					strcpy(addinfo, " ICMP");
					break;
				case 2:
					strcpy(addinfo, " IGMP");
					break;
				case 4:
					strcpy(addinfo, " IPIP");
					break;
				case 6:
					ipp = (ip_ports *) (&p[data_ofs]);
					sprintf(addinfo, " TCP, port: %d -> %d", ntohs(ipp->source),
						ntohs(ipp->dest));
					break;
				case 8:
					strcpy(addinfo, " EGP");
					break;
				case 12:
					strcpy(addinfo, " PUP");
					break;
				case 17:
					ipp = (ip_ports *) (&p[data_ofs]);
					sprintf(addinfo, " UDP, port: %d -> %d", ntohs(ipp->source),
						ntohs(ipp->dest));
					break;
				case 22:
					strcpy(addinfo, " IDP");
					break;
			}
			printk(KERN_INFO "OPEN: %pI4 -> %pI4%s\n",
			       p + 12, p + 16, addinfo);
			break;
		case ETH_P_ARP:
			printk(KERN_INFO "OPEN: ARP %pI4 -> *.*.*.* ?%pI4\n",
			       p + 14, p + 24);
			break;
	}
}

/*
 * this function is used to send supervisory data, i.e. data which was
 * not received from the network layer, but e.g. frames from ipppd, CCP
 * reset frames etc.
 */
void isdn_net_write_super(isdn_net_local *lp, struct sk_buff *skb)
{
	if (in_irq()) {
		// we can't grab the lock from irq context, 
		// so we just queue the packet
		skb_queue_tail(&lp->super_tx_queue, skb);
		schedule_work(&lp->tqueue);
		return;
	}

	spin_lock_bh(&lp->xmit_lock);
	if (!isdn_net_lp_busy(lp)) {
		isdn_net_writebuf_skb(lp, skb);
	} else {
		skb_queue_tail(&lp->super_tx_queue, skb);
	}
	spin_unlock_bh(&lp->xmit_lock);
}

/*
 * called from tq_immediate
 */
static void isdn_net_softint(struct work_struct *work)
{
	isdn_net_local *lp = container_of(work, isdn_net_local, tqueue);
	struct sk_buff *skb;

	spin_lock_bh(&lp->xmit_lock);
	while (!isdn_net_lp_busy(lp)) {
		skb = skb_dequeue(&lp->super_tx_queue);
		if (!skb)
			break;
		isdn_net_writebuf_skb(lp, skb);                                
	}
	spin_unlock_bh(&lp->xmit_lock);
}

/* 
 * all frames sent from the (net) LL to a HL driver should go via this function
 * it's serialized by the caller holding the lp->xmit_lock spinlock
 */
void isdn_net_writebuf_skb(isdn_net_local *lp, struct sk_buff *skb)
{
	int ret;
	int len = skb->len;     /* save len */

	/* before obtaining the lock the caller should have checked that
	   the lp isn't busy */
	if (isdn_net_lp_busy(lp)) {
		printk("isdn BUG at %s:%d!\n", __FILE__, __LINE__);
		goto error;
	}

	if (!(lp->flags & ISDN_NET_CONNECTED)) {
		printk("isdn BUG at %s:%d!\n", __FILE__, __LINE__);
		goto error;
	}
	ret = isdn_writebuf_skb_stub(lp->isdn_device, lp->isdn_channel, 1, skb);
	if (ret != len) {
		/* we should never get here */
		printk(KERN_WARNING "%s: HL driver queue full\n", lp->netdev->dev->name);
		goto error;
	}
	
	lp->transcount += len;
	isdn_net_inc_frame_cnt(lp);
	return;

 error:
	dev_kfree_skb(skb);
	lp->stats.tx_errors++;

}


/*
 *  Helper function for isdn_net_start_xmit.
 *  When called, the connection is already established.
 *  Based on cps-calculation, check if device is overloaded.
 *  If so, and if a slave exists, trigger dialing for it.
 *  If any slave is online, deliver packets using a simple round robin
 *  scheme.
 *
 *  Return: 0 on success, !0 on failure.
 */

static int
isdn_net_xmit(struct net_device *ndev, struct sk_buff *skb)
{
	isdn_net_dev *nd;
	isdn_net_local *slp;
	isdn_net_local *lp = netdev_priv(ndev);
	int retv = NETDEV_TX_OK;

	if (((isdn_net_local *) netdev_priv(ndev))->master) {
		printk("isdn BUG at %s:%d!\n", __FILE__, __LINE__);
		dev_kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	/* For the other encaps the header has already been built */
#ifdef CONFIG_ISDN_PPP
	if (lp->p_encap == ISDN_NET_ENCAP_SYNCPPP) {
		return isdn_ppp_xmit(skb, ndev);
	}
#endif
	nd = ((isdn_net_local *) netdev_priv(ndev))->netdev;
	lp = isdn_net_get_locked_lp(nd);
	if (!lp) {
		printk(KERN_WARNING "%s: all channels busy - requeuing!\n", ndev->name);
		return NETDEV_TX_BUSY;
	}
	/* we have our lp locked from now on */

	/* Reset hangup-timeout */
	lp->huptimer = 0; // FIXME?
	isdn_net_writebuf_skb(lp, skb);
	spin_unlock_bh(&lp->xmit_lock);

	/* the following stuff is here for backwards compatibility.
	 * in future, start-up and hangup of slaves (based on current load)
	 * should move to userspace and get based on an overall cps
	 * calculation
	 */
	if (lp->cps > lp->triggercps) {
		if (lp->slave) {
			if (!lp->sqfull) {
				/* First time overload: set timestamp only */
				lp->sqfull = 1;
				lp->sqfull_stamp = jiffies;
			} else {
				/* subsequent overload: if slavedelay exceeded, start dialing */
				if (time_after(jiffies, lp->sqfull_stamp + lp->slavedelay)) {
					slp = ISDN_SLAVE_PRIV(lp);
					if (!(slp->flags & ISDN_NET_CONNECTED)) {
						isdn_net_force_dial_lp(ISDN_SLAVE_PRIV(lp));
					}
				}
			}
		}
	} else {
		if (lp->sqfull && time_after(jiffies, lp->sqfull_stamp + lp->slavedelay + (10 * HZ))) {
			lp->sqfull = 0;
		}
		/* this is a hack to allow auto-hangup for slaves on moderate loads */
		nd->queue = nd->local;
	}

	return retv;

}

static void
isdn_net_adjust_hdr(struct sk_buff *skb, struct net_device *dev)
{
	isdn_net_local *lp = netdev_priv(dev);
	if (!skb)
		return;
	if (lp->p_encap == ISDN_NET_ENCAP_ETHER) {
		const int pullsize = skb_network_offset(skb) - ETH_HLEN;
		if (pullsize > 0) {
			printk(KERN_DEBUG "isdn_net: Pull junk %d\n", pullsize);
			skb_pull(skb, pullsize);
		}
	}
}


static void isdn_net_tx_timeout(struct net_device * ndev)
{
	isdn_net_local *lp = netdev_priv(ndev);

	printk(KERN_WARNING "isdn_tx_timeout dev %s dialstate %d\n", ndev->name, lp->dialstate);
	if (!lp->dialstate){
		lp->stats.tx_errors++;
                /*
		 * There is a certain probability that this currently
		 * works at all because if we always wake up the interface,
		 * then upper layer will try to send the next packet
		 * immediately. And then, the old clean_up logic in the
		 * driver will hopefully continue to work as it used to do.
		 *
		 * This is rather primitive right know, we better should
		 * clean internal queues here, in particular for multilink and
		 * ppp, and reset HL driver's channel, too.   --HE
		 *
		 * actually, this may not matter at all, because ISDN hardware
		 * should not see transmitter hangs at all IMO
		 * changed KERN_DEBUG to KERN_WARNING to find out if this is 
		 * ever called   --KG
		 */
	}
	ndev->trans_start = jiffies;
	netif_wake_queue(ndev);
}

/*
 * Try sending a packet.
 * If this interface isn't connected to a ISDN-Channel, find a free channel,
 * and start dialing.
 */
static netdev_tx_t
isdn_net_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	isdn_net_local *lp = netdev_priv(ndev);
#ifdef CONFIG_ISDN_X25
	struct concap_proto * cprot = lp -> netdev -> cprot;
/* At this point hard_start_xmit() passes control to the encapsulation
   protocol (if present).
   For X.25 auto-dialing is completly bypassed because:
   - It does not conform with the semantics of a reliable datalink
     service as needed by X.25 PLP.
   - I don't want that the interface starts dialing when the network layer
     sends a message which requests to disconnect the lapb link (or if it
     sends any other message not resulting in data transmission).
   Instead, dialing will be initiated by the encapsulation protocol entity
   when a dl_establish request is received from the upper layer.
*/
	if (cprot && cprot -> pops) {
		int ret = cprot -> pops -> encap_and_xmit ( cprot , skb);

		if (ret)
			netif_stop_queue(ndev);
		return ret;
	} else
#endif
	/* auto-dialing xmit function */
	{
#ifdef ISDN_DEBUG_NET_DUMP
		u_char *buf;
#endif
		isdn_net_adjust_hdr(skb, ndev);
#ifdef ISDN_DEBUG_NET_DUMP
		buf = skb->data;
		isdn_dumppkt("S:", buf, skb->len, 40);
#endif

		if (!(lp->flags & ISDN_NET_CONNECTED)) {
			int chi;
			/* only do autodial if allowed by config */
			if (!(ISDN_NET_DIALMODE(*lp) == ISDN_NET_DM_AUTO)) {
				isdn_net_unreachable(ndev, skb, "dial rejected: interface not in dialmode `auto'");
				dev_kfree_skb(skb);
				return NETDEV_TX_OK;
			}
			if (lp->phone[1]) {
				ulong flags;

				if(lp->dialwait_timer <= 0)
					if(lp->dialstarted > 0 && lp->dialtimeout > 0 && time_before(jiffies, lp->dialstarted + lp->dialtimeout + lp->dialwait))
						lp->dialwait_timer = lp->dialstarted + lp->dialtimeout + lp->dialwait;

				if(lp->dialwait_timer > 0) {
					if(time_before(jiffies, lp->dialwait_timer)) {
						isdn_net_unreachable(ndev, skb, "dial rejected: retry-time not reached");
						dev_kfree_skb(skb);
						return NETDEV_TX_OK;
					} else
						lp->dialwait_timer = 0;
				}
				/* Grab a free ISDN-Channel */
				spin_lock_irqsave(&dev->lock, flags);
				if (((chi =
				     isdn_get_free_channel(
					 		ISDN_USAGE_NET,
							lp->l2_proto,
							lp->l3_proto,
							lp->pre_device,
						 	lp->pre_channel,
							lp->msn)
							) < 0) &&
					((chi =
				     isdn_get_free_channel(
					 		ISDN_USAGE_NET,
							lp->l2_proto,
							lp->l3_proto,
							lp->pre_device,
							lp->pre_channel^1,
							lp->msn)
							) < 0)) {
					spin_unlock_irqrestore(&dev->lock, flags);
					isdn_net_unreachable(ndev, skb,
							   "No channel");
					dev_kfree_skb(skb);
					return NETDEV_TX_OK;
				}
				/* Log packet, which triggered dialing */
				if (dev->net_verbose)
					isdn_net_log_skb(skb, lp);
				lp->dialstate = 1;
				/* Connect interface with channel */
				isdn_net_bind_channel(lp, chi);
#ifdef CONFIG_ISDN_PPP
				if (lp->p_encap == ISDN_NET_ENCAP_SYNCPPP) {
					/* no 'first_skb' handling for syncPPP */
					if (isdn_ppp_bind(lp) < 0) {
						dev_kfree_skb(skb);
						isdn_net_unbind_channel(lp);
						spin_unlock_irqrestore(&dev->lock, flags);
						return NETDEV_TX_OK;	/* STN (skb to nirvana) ;) */
					}
#ifdef CONFIG_IPPP_FILTER
					if (isdn_ppp_autodial_filter(skb, lp)) {
						isdn_ppp_free(lp);
						isdn_net_unbind_channel(lp);
						spin_unlock_irqrestore(&dev->lock, flags);
						isdn_net_unreachable(ndev, skb, "dial rejected: packet filtered");
						dev_kfree_skb(skb);
						return NETDEV_TX_OK;
					}
#endif
					spin_unlock_irqrestore(&dev->lock, flags);
					isdn_net_dial();	/* Initiate dialing */
					netif_stop_queue(ndev);
					return NETDEV_TX_BUSY;	/* let upper layer requeue skb packet */
				}
#endif
				/* Initiate dialing */
				spin_unlock_irqrestore(&dev->lock, flags);
				isdn_net_dial();
				isdn_net_device_stop_queue(lp);
				return NETDEV_TX_BUSY;
			} else {
				isdn_net_unreachable(ndev, skb,
						     "No phone number");
				dev_kfree_skb(skb);
				return NETDEV_TX_OK;
			}
		} else {
			/* Device is connected to an ISDN channel */ 
			ndev->trans_start = jiffies;
			if (!lp->dialstate) {
				/* ISDN connection is established, try sending */
				int ret;
				ret = (isdn_net_xmit(ndev, skb));
				if(ret) netif_stop_queue(ndev);
				return ret;
			} else
				netif_stop_queue(ndev);
		}
	}
	return NETDEV_TX_BUSY;
}

/*
 * Shutdown a net-interface.
 */
static int
isdn_net_close(struct net_device *dev)
{
	struct net_device *p;
#ifdef CONFIG_ISDN_X25
	struct concap_proto * cprot =
		((isdn_net_local *) netdev_priv(dev))->netdev->cprot;
	/* printk(KERN_DEBUG "isdn_net_close %s\n" , dev-> name ); */
#endif

#ifdef CONFIG_ISDN_X25
	if( cprot && cprot -> pops ) cprot -> pops -> close( cprot );
#endif
	netif_stop_queue(dev);
	p = MASTER_TO_SLAVE(dev);
	if (p) {
		/* If this interface has slaves, stop them also */
		while (p) {
#ifdef CONFIG_ISDN_X25
			cprot = ((isdn_net_local *) netdev_priv(p))
				-> netdev -> cprot;
			if( cprot && cprot -> pops )
				cprot -> pops -> close( cprot );
#endif
			isdn_net_hangup(p);
			p = MASTER_TO_SLAVE(p);
		}
	}
	isdn_net_hangup(dev);
	isdn_unlock_drivers();
	return 0;
}

/*
 * Get statistics
 */
static struct net_device_stats *
isdn_net_get_stats(struct net_device *dev)
{
	isdn_net_local *lp = netdev_priv(dev);
	return &lp->stats;
}

/*      This is simply a copy from std. eth.c EXCEPT we pull ETH_HLEN
 *      instead of dev->hard_header_len off. This is done because the
 *      lowlevel-driver has already pulled off its stuff when we get
 *      here and this routine only gets called with p_encap == ETHER.
 *      Determine the packet's protocol ID. The rule here is that we
 *      assume 802.3 if the type field is short enough to be a length.
 *      This is normal practice and works for any 'now in use' protocol.
 */

static __be16
isdn_net_type_trans(struct sk_buff *skb, struct net_device *dev)
{
	struct ethhdr *eth;
	unsigned char *rawp;

	skb_reset_mac_header(skb);
	skb_pull(skb, ETH_HLEN);
	eth = eth_hdr(skb);

	if (*eth->h_dest & 1) {
		if (memcmp(eth->h_dest, dev->broadcast, ETH_ALEN) == 0)
			skb->pkt_type = PACKET_BROADCAST;
		else
			skb->pkt_type = PACKET_MULTICAST;
	}
	/*
	 *      This ALLMULTI check should be redundant by 1.4
	 *      so don't forget to remove it.
	 */

	else if (dev->flags & (IFF_PROMISC /*| IFF_ALLMULTI*/)) {
		if (memcmp(eth->h_dest, dev->dev_addr, ETH_ALEN))
			skb->pkt_type = PACKET_OTHERHOST;
	}
	if (ntohs(eth->h_proto) >= 1536)
		return eth->h_proto;

	rawp = skb->data;

	/*
	 *      This is a magic hack to spot IPX packets. Older Novell breaks
	 *      the protocol design and runs IPX over 802.3 without an 802.2 LLC
	 *      layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
	 *      won't work for fault tolerant netware but does for the rest.
	 */
	if (*(unsigned short *) rawp == 0xFFFF)
		return htons(ETH_P_802_3);
	/*
	 *      Real 802.2 LLC
	 */
	return htons(ETH_P_802_2);
}


/* 
 * CISCO HDLC keepalive specific stuff
 */
static struct sk_buff*
isdn_net_ciscohdlck_alloc_skb(isdn_net_local *lp, int len)
{
	unsigned short hl = dev->drv[lp->isdn_device]->interface->hl_hdrlen;
	struct sk_buff *skb;

	skb = alloc_skb(hl + len, GFP_ATOMIC);
	if (skb)
		skb_reserve(skb, hl);
	else 
		printk("isdn out of mem at %s:%d!\n", __FILE__, __LINE__);
	return skb;
}

/* cisco hdlck device private ioctls */
static int
isdn_ciscohdlck_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	isdn_net_local *lp = netdev_priv(dev);
	unsigned long len = 0;
	unsigned long expires = 0;
	int tmp = 0;
	int period = lp->cisco_keepalive_period;
	s8 debserint = lp->cisco_debserint;
	int rc = 0;

	if (lp->p_encap != ISDN_NET_ENCAP_CISCOHDLCK)
		return -EINVAL;

	switch (cmd) {
		/* get/set keepalive period */
		case SIOCGKEEPPERIOD:
			len = (unsigned long)sizeof(lp->cisco_keepalive_period);
			if (copy_to_user(ifr->ifr_data,
				&lp->cisco_keepalive_period, len))
				rc = -EFAULT;
			break;
		case SIOCSKEEPPERIOD:
			tmp = lp->cisco_keepalive_period;
			len = (unsigned long)sizeof(lp->cisco_keepalive_period);
			if (copy_from_user(&period, ifr->ifr_data, len))
				rc = -EFAULT;
			if ((period > 0) && (period <= 32767))
				lp->cisco_keepalive_period = period;
			else
				rc = -EINVAL;
			if (!rc && (tmp != lp->cisco_keepalive_period)) {
				expires = (unsigned long)(jiffies +
					lp->cisco_keepalive_period * HZ);
				mod_timer(&lp->cisco_timer, expires);
				printk(KERN_INFO "%s: Keepalive period set "
					"to %d seconds.\n",
					dev->name, lp->cisco_keepalive_period);
			}
			break;

		/* get/set debugging */
		case SIOCGDEBSERINT:
			len = (unsigned long)sizeof(lp->cisco_debserint);
			if (copy_to_user(ifr->ifr_data,
				&lp->cisco_debserint, len))
				rc = -EFAULT;
			break;
		case SIOCSDEBSERINT:
			len = (unsigned long)sizeof(lp->cisco_debserint);
			if (copy_from_user(&debserint,
				ifr->ifr_data, len))
				rc = -EFAULT;
			if ((debserint >= 0) && (debserint <= 64))
				lp->cisco_debserint = debserint;
			else
				rc = -EINVAL;
			break;

		default:
			rc = -EINVAL;
			break;
	}
	return (rc);
}


static int isdn_net_ioctl(struct net_device *dev,
			  struct ifreq *ifr, int cmd)
{
	isdn_net_local *lp = netdev_priv(dev);

	switch (lp->p_encap) {
#ifdef CONFIG_ISDN_PPP
	case ISDN_NET_ENCAP_SYNCPPP:
		return isdn_ppp_dev_ioctl(dev, ifr, cmd);
#endif
	case ISDN_NET_ENCAP_CISCOHDLCK:
		return isdn_ciscohdlck_dev_ioctl(dev, ifr, cmd);
	default:
		return -EINVAL;
	}
}

/* called via cisco_timer.function */
static void
isdn_net_ciscohdlck_slarp_send_keepalive(unsigned long data)
{
	isdn_net_local *lp = (isdn_net_local *) data;
	struct sk_buff *skb;
	unsigned char *p;
	unsigned long last_cisco_myseq = lp->cisco_myseq;
	int myseq_diff = 0;

	if (!(lp->flags & ISDN_NET_CONNECTED) || lp->dialstate) {
		printk("isdn BUG at %s:%d!\n", __FILE__, __LINE__);
		return;
	}
	lp->cisco_myseq++;

	myseq_diff = (lp->cisco_myseq - lp->cisco_mineseen);
	if ((lp->cisco_line_state) && ((myseq_diff >= 3)||(myseq_diff <= -3))) {
		/* line up -> down */
		lp->cisco_line_state = 0;
		printk (KERN_WARNING
				"UPDOWN: Line protocol on Interface %s,"
				" changed state to down\n", lp->netdev->dev->name);
		/* should stop routing higher-level data across */
	} else if ((!lp->cisco_line_state) &&
		(myseq_diff >= 0) && (myseq_diff <= 2)) {
		/* line down -> up */
		lp->cisco_line_state = 1;
		printk (KERN_WARNING
				"UPDOWN: Line protocol on Interface %s,"
				" changed state to up\n", lp->netdev->dev->name);
		/* restart routing higher-level data across */
	}

	if (lp->cisco_debserint)
		printk (KERN_DEBUG "%s: HDLC "
			"myseq %lu, mineseen %lu%c, yourseen %lu, %s\n",
			lp->netdev->dev->name, last_cisco_myseq, lp->cisco_mineseen,
			((last_cisco_myseq == lp->cisco_mineseen) ? '*' : 040),
			lp->cisco_yourseq,
			((lp->cisco_line_state) ? "line up" : "line down"));

	skb = isdn_net_ciscohdlck_alloc_skb(lp, 4 + 14);
	if (!skb)
		return;

	p = skb_put(skb, 4 + 14);

	/* cisco header */
	*(u8 *)(p + 0) = CISCO_ADDR_UNICAST;
	*(u8 *)(p + 1) = CISCO_CTRL;
	*(__be16 *)(p + 2) = cpu_to_be16(CISCO_TYPE_SLARP);

	/* slarp keepalive */
	*(__be32 *)(p +  4) = cpu_to_be32(CISCO_SLARP_KEEPALIVE);
	*(__be32 *)(p +  8) = cpu_to_be32(lp->cisco_myseq);
	*(__be32 *)(p + 12) = cpu_to_be32(lp->cisco_yourseq);
	*(__be16 *)(p + 16) = cpu_to_be16(0xffff); // reliability, always 0xffff
	p += 18;

	isdn_net_write_super(lp, skb);

	lp->cisco_timer.expires = jiffies + lp->cisco_keepalive_period * HZ;
	
	add_timer(&lp->cisco_timer);
}

static void
isdn_net_ciscohdlck_slarp_send_request(isdn_net_local *lp)
{
	struct sk_buff *skb;
	unsigned char *p;

	skb = isdn_net_ciscohdlck_alloc_skb(lp, 4 + 14);
	if (!skb)
		return;

	p = skb_put(skb, 4 + 14);

	/* cisco header */
	*(u8 *)(p + 0) = CISCO_ADDR_UNICAST;
	*(u8 *)(p + 1) = CISCO_CTRL;
	*(__be16 *)(p + 2) = cpu_to_be16(CISCO_TYPE_SLARP);

	/* slarp request */
	*(__be32 *)(p +  4) = cpu_to_be32(CISCO_SLARP_REQUEST);
	*(__be32 *)(p +  8) = cpu_to_be32(0); // address
	*(__be32 *)(p + 12) = cpu_to_be32(0); // netmask
	*(__be16 *)(p + 16) = cpu_to_be16(0); // unused
	p += 18;

	isdn_net_write_super(lp, skb);
}

static void 
isdn_net_ciscohdlck_connected(isdn_net_local *lp)
{
	lp->cisco_myseq = 0;
	lp->cisco_mineseen = 0;
	lp->cisco_yourseq = 0;
	lp->cisco_keepalive_period = ISDN_TIMER_KEEPINT;
	lp->cisco_last_slarp_in = 0;
	lp->cisco_line_state = 0;
	lp->cisco_debserint = 0;

	/* send slarp request because interface/seq.no.s reset */
	isdn_net_ciscohdlck_slarp_send_request(lp);

	init_timer(&lp->cisco_timer);
	lp->cisco_timer.data = (unsigned long) lp;
	lp->cisco_timer.function = isdn_net_ciscohdlck_slarp_send_keepalive;
	lp->cisco_timer.expires = jiffies + lp->cisco_keepalive_period * HZ;
	add_timer(&lp->cisco_timer);
}

static void 
isdn_net_ciscohdlck_disconnected(isdn_net_local *lp)
{
	del_timer(&lp->cisco_timer);
}

static void
isdn_net_ciscohdlck_slarp_send_reply(isdn_net_local *lp)
{
	struct sk_buff *skb;
	unsigned char *p;
	struct in_device *in_dev = NULL;
	__be32 addr = 0;		/* local ipv4 address */
	__be32 mask = 0;		/* local netmask */

	if ((in_dev = lp->netdev->dev->ip_ptr) != NULL) {
		/* take primary(first) address of interface */
		struct in_ifaddr *ifa = in_dev->ifa_list;
		if (ifa != NULL) {
			addr = ifa->ifa_local;
			mask = ifa->ifa_mask;
		}
	}

	skb = isdn_net_ciscohdlck_alloc_skb(lp, 4 + 14);
	if (!skb)
		return;

	p = skb_put(skb, 4 + 14);

	/* cisco header */
	*(u8 *)(p + 0) = CISCO_ADDR_UNICAST;
	*(u8 *)(p + 1) = CISCO_CTRL;
	*(__be16 *)(p + 2) = cpu_to_be16(CISCO_TYPE_SLARP);

	/* slarp reply, send own ip/netmask; if values are nonsense remote
	 * should think we are unable to provide it with an address via SLARP */
	*(__be32 *)(p +  4) = cpu_to_be32(CISCO_SLARP_REPLY);
	*(__be32 *)(p +  8) = addr; // address
	*(__be32 *)(p + 12) = mask; // netmask
	*(__be16 *)(p + 16) = cpu_to_be16(0); // unused
	p += 18;

	isdn_net_write_super(lp, skb);
}

static void
isdn_net_ciscohdlck_slarp_in(isdn_net_local *lp, struct sk_buff *skb)
{
	unsigned char *p;
	int period;
	u32 code;
	u32 my_seq;
	u32 your_seq;
	__be32 local;
	__be32 *addr, *mask;

	if (skb->len < 14)
		return;

	p = skb->data;
	code = be32_to_cpup((__be32 *)p);
	p += 4;

	switch (code) {
	case CISCO_SLARP_REQUEST:
		lp->cisco_yourseq = 0;
		isdn_net_ciscohdlck_slarp_send_reply(lp);
		break;
	case CISCO_SLARP_REPLY:
		addr = (__be32 *)p;
		mask = (__be32 *)(p + 4);
		if (*mask != cpu_to_be32(0xfffffffc))
			goto slarp_reply_out;
		if ((*addr & cpu_to_be32(3)) == cpu_to_be32(0) ||
		    (*addr & cpu_to_be32(3)) == cpu_to_be32(3))
			goto slarp_reply_out;
		local = *addr ^ cpu_to_be32(3);
		printk(KERN_INFO "%s: got slarp reply: remote ip: %pI4, local ip: %pI4 mask: %pI4\n",
		       lp->netdev->dev->name, addr, &local, mask);
		break;
  slarp_reply_out:
		printk(KERN_INFO "%s: got invalid slarp reply (%pI4/%pI4) - ignored\n",
		       lp->netdev->dev->name, addr, mask);
		break;
	case CISCO_SLARP_KEEPALIVE:
		period = (int)((jiffies - lp->cisco_last_slarp_in
				+ HZ/2 - 1) / HZ);
		if (lp->cisco_debserint &&
				(period != lp->cisco_keepalive_period) &&
				lp->cisco_last_slarp_in) {
			printk(KERN_DEBUG "%s: Keepalive period mismatch - "
				"is %d but should be %d.\n",
				lp->netdev->dev->name, period,
				lp->cisco_keepalive_period);
		}
		lp->cisco_last_slarp_in = jiffies;
		my_seq = be32_to_cpup((__be32 *)(p + 0));
		your_seq = be32_to_cpup((__be32 *)(p + 4));
		p += 10;
		lp->cisco_yourseq = my_seq;
		lp->cisco_mineseen = your_seq;
		break;
	}
}

static void
isdn_net_ciscohdlck_receive(isdn_net_local *lp, struct sk_buff *skb)
{
	unsigned char *p;
 	u8 addr;
 	u8 ctrl;
 	u16 type;
	
	if (skb->len < 4)
		goto out_free;

	p = skb->data;
	addr = *(u8 *)(p + 0);
	ctrl = *(u8 *)(p + 1);
	type = be16_to_cpup((__be16 *)(p + 2));
	p += 4;
	skb_pull(skb, 4);
	
	if (addr != CISCO_ADDR_UNICAST && addr != CISCO_ADDR_BROADCAST) {
		printk(KERN_WARNING "%s: Unknown Cisco addr 0x%02x\n",
		       lp->netdev->dev->name, addr);
		goto out_free;
	}
	if (ctrl != CISCO_CTRL) {
		printk(KERN_WARNING "%s: Unknown Cisco ctrl 0x%02x\n",
		       lp->netdev->dev->name, ctrl);
		goto out_free;
	}

	switch (type) {
	case CISCO_TYPE_SLARP:
		isdn_net_ciscohdlck_slarp_in(lp, skb);
		goto out_free;
	case CISCO_TYPE_CDP:
		if (lp->cisco_debserint)
			printk(KERN_DEBUG "%s: Received CDP packet. use "
				"\"no cdp enable\" on cisco.\n",
				lp->netdev->dev->name);
		goto out_free;
	default:
		/* no special cisco protocol */
		skb->protocol = htons(type);
		netif_rx(skb);
		return;
	}

 out_free:
	kfree_skb(skb);
}

/*
 * Got a packet from ISDN-Channel.
 */
static void
isdn_net_receive(struct net_device *ndev, struct sk_buff *skb)
{
	isdn_net_local *lp = netdev_priv(ndev);
	isdn_net_local *olp = lp;	/* original 'lp' */
#ifdef CONFIG_ISDN_X25
	struct concap_proto *cprot = lp -> netdev -> cprot;
#endif
	lp->transcount += skb->len;

	lp->stats.rx_packets++;
	lp->stats.rx_bytes += skb->len;
	if (lp->master) {
		/* Bundling: If device is a slave-device, deliver to master, also
		 * handle master's statistics and hangup-timeout
		 */
		ndev = lp->master;
		lp = netdev_priv(ndev);
		lp->stats.rx_packets++;
		lp->stats.rx_bytes += skb->len;
	}
	skb->dev = ndev;
	skb->pkt_type = P…