/*****************************************************************************
* sdla_ppp.c	WANPIPE(tm) Multiprotocol WAN Link Driver. PPP module.
*
* Author: 	Jaspreet Singh 	<jaspreet@sangoma.com>
*
* Copyright:	(c) 1995-1997 Sangoma Technologies Inc.
*
*		This program is free software; you can redistribute it and/or
*		modify it under the terms of the GNU General Public License
*		as published by the Free Software Foundation; either version
*		2 of the License, or (at your option) any later version.
* ============================================================================
* Nov 27, 1997	Jaspreet Singh	o Added protection against enabling of irqs 
*				  while they have been disabled.
* Nov 24, 1997  Jaspreet Singh  o Fixed another RACE condition caused by
*                                 disabling and enabling of irqs.
*                               o Added new counters for stats on disable/enable*                                 IRQs.
* Nov 10, 1997	Jaspreet Singh	o Initialized 'skb->mac.raw' to 'skb->data'
*				  before every netif_rx().
*				o Free up the device structure in del_if().
* Nov 07, 1997	Jaspreet Singh	o Changed the delay to zero for Line tracing
*				  command.
* Oct 20, 1997 	Jaspreet Singh	o Added hooks in for Router UP time.
* Oct 16, 1997	Jaspreet Singh  o The critical flag is used to maintain flow
*				  control by avoiding RACE conditions.  The 
*				  cli() and restore_flags() are taken out.
*				  A new structure, "ppp_private_area", is added 
*				  to provide Driver Statistics.   
* Jul 21, 1997 	Jaspreet Singh	o Protected calls to sdla_peek() by adding 
*				  save_flags(), cli() and restore_flags().
* Jul 07, 1997	Jaspreet Singh  o Added configurable TTL for UDP packets
*				o Added ability to discard mulitcast and
*				  broacast source addressed packets.
* Jun 27, 1997 	Jaspreet Singh	o Added FT1 monitor capabilities
*				  New case (0x25) statement in if_send routine.
*				  Added a global variable rCount to keep track
*				  of FT1 status enabled on the board.
* May 22, 1997	Jaspreet Singh	o Added change in the PPP_SET_CONFIG command for
*				508 card to reflect changes in the new 
*				ppp508.sfm for supporting:continous transmission
*				of Configure-Request packets without receiving a
*				reply 				
*				OR-ed 0x300 to conf_flags 
*			        o Changed connect_tmout from 900 to 0
* May 21, 1997	Jaspreet Singh  o Fixed UDP Management for multiple boards
* Apr 25, 1997  Farhan Thawar    o added UDP Management stuff
* Mar 11, 1997  Farhan Thawar   Version 3.1.1
*                                o fixed (+1) bug in rx_intr()
*                                o changed if_send() to return 0 if
*                                  wandev.critical() is true
*                                o free socket buffer in if_send() if
*                                  returning 0 
* Jan 15, 1997	Gene Kozin	Version 3.1.0
*				 o implemented exec() entry point
* Jan 06, 1997	Gene Kozin	Initial version.
*****************************************************************************/

#if	!defined(__KERNEL__) || !defined(MODULE)
#error	This code MUST be compiled as a kernel module!
#endif

#include <linux/kernel.h>	/* printk(), and other useful stuff */
#include <linux/stddef.h>	/* offsetof(), etc. */
#include <linux/errno.h>	/* return codes */
#include <linux/string.h>	/* inline memset(), etc. */
#include <linux/malloc.h>	/* kmalloc(), kfree() */
#include <linux/wanrouter.h>	/* WAN router definitions */
#include <linux/wanpipe.h>	/* WANPIPE common user API definitions */
#include <linux/if_arp.h>	/* ARPHRD_* defines */
#include <linux/init.h>		/* __initfunc et al. */
#include <asm/byteorder.h>	/* htons(), etc. */
#include <asm/uaccess.h>

#define	_GNUC_
#include <linux/sdla_ppp.h>	/* PPP firmware API definitions */

/****** Defines & Macros ****************************************************/

#ifdef	_DEBUG_
#define	STATIC
#else
#define	STATIC		static
#endif

#define	PPP_DFLT_MTU	1500		/* default MTU */
#define	PPP_MAX_MTU	4000		/* maximum MTU */
#define PPP_HDR_LEN	1

#define	CONNECT_TIMEOUT	(90*HZ)		/* link connection timeout */
#define	HOLD_DOWN_TIME	(30*HZ)		/* link hold down time */

/* For handle_IPXWAN() */
#define CVHexToAscii(b) (((unsigned char)(b) > (unsigned char)9) ? ((unsigned char)'A' + ((unsigned char)(b) - (unsigned char)10)) : ((unsigned char)'0' + (unsigned char)(b)))
 
/******Data Structures*****************************************************/

/* This structure is placed in the private data area of the device structure.
 * The card structure used to occupy the private area but now the following 
 * structure will incorporate the card structure along with PPP specific data
 */
  
typedef struct ppp_private_area
{
	sdla_t* card;	
	unsigned long router_start_time;	/*router start time in sec */
	unsigned long tick_counter;		/*used for 5 second counter*/
	unsigned mc;				/*multicast support on or off*/
	/* PPP specific statistics */
	unsigned long if_send_entry;
	unsigned long if_send_skb_null;
	unsigned long if_send_broadcast;
	unsigned long if_send_multicast;
	unsigned long if_send_critical_ISR;
	unsigned long if_send_critical_non_ISR;
	unsigned long if_send_busy;
	unsigned long if_send_busy_timeout;
	unsigned long if_send_DRVSTATS_request;
	unsigned long if_send_PTPIPE_request;
	unsigned long if_send_wan_disconnected;
	unsigned long if_send_adptr_bfrs_full;
	unsigned long if_send_protocol_error;
	unsigned long if_send_tx_int_enabled;
	unsigned long if_send_bfr_passed_to_adptr;
	
	unsigned long rx_intr_no_socket;
	unsigned long rx_intr_DRVSTATS_request;
	unsigned long rx_intr_PTPIPE_request;
	unsigned long rx_intr_bfr_not_passed_to_stack;
	unsigned long rx_intr_bfr_passed_to_stack;

	unsigned long UDP_PTPIPE_mgmt_kmalloc_err;
	unsigned long UDP_PTPIPE_mgmt_adptr_type_err;
	unsigned long UDP_PTPIPE_mgmt_direction_err;
	unsigned long UDP_PTPIPE_mgmt_adptr_cmnd_timeout;
	unsigned long UDP_PTPIPE_mgmt_adptr_cmnd_OK;
	unsigned long UDP_PTPIPE_mgmt_passed_to_adptr;
	unsigned long UDP_PTPIPE_mgmt_passed_to_stack;
	unsigned long UDP_PTPIPE_mgmt_no_socket;	
	
	unsigned long UDP_DRVSTATS_mgmt_kmalloc_err;
	unsigned long UDP_DRVSTATS_mgmt_adptr_type_err;
	unsigned long UDP_DRVSTATS_mgmt_direction_err;
	unsigned long UDP_DRVSTATS_mgmt_adptr_cmnd_timeout;
	unsigned long UDP_DRVSTATS_mgmt_adptr_cmnd_OK;
	unsigned long UDP_DRVSTATS_mgmt_passed_to_adptr;
	unsigned long UDP_DRVSTATS_mgmt_passed_to_stack;
	unsigned long UDP_DRVSTATS_mgmt_no_socket;	

	unsigned long router_up_time; 

}ppp_private_area_t;

/* variable for keeping track of enabling/disabling FT1 monitor status */
static int rCount = 0;

extern void disable_irq(unsigned int);
extern void enable_irq(unsigned int);

/****** Function Prototypes *************************************************/

/* WAN link driver entry points. These are called by the WAN router module. */
static int update (wan_device_t* wandev);
static int new_if (wan_device_t* wandev, struct device* dev,
	wanif_conf_t* conf);
static int del_if (wan_device_t* wandev, struct device* dev);

/* WANPIPE-specific entry points */
static int wpp_exec (struct sdla* card, void* u_cmd, void* u_data);

/* Network device interface */
static int if_init   (struct device* dev);
static int if_open   (struct device* dev);
static int if_close  (struct device* dev);
static int if_header (struct sk_buff* skb, struct device* dev,
	unsigned short type, void* daddr, void* saddr, unsigned len);
static int if_rebuild_hdr (struct sk_buff* skb);
static int if_send (struct sk_buff* skb, struct device* dev);
static struct enet_statistics* if_stats (struct device* dev);


/* PPP firmware interface functions */
static int ppp_read_version (sdla_t* card, char* str);
static int ppp_configure (sdla_t* card, void* data);
static int ppp_set_intr_mode (sdla_t* card, unsigned mode);
static int ppp_comm_enable (sdla_t* card);
static int ppp_comm_disable (sdla_t* card);
static int ppp_get_err_stats (sdla_t* card);
static int ppp_send (sdla_t* card, void* data, unsigned len, unsigned proto);
static int ppp_error (sdla_t *card, int err, ppp_mbox_t* mb);

/* Interrupt handlers */
STATIC void wpp_isr (sdla_t* card);
static void rx_intr (sdla_t* card);
static void tx_intr (sdla_t* card);

/* Background polling routines */
static void wpp_poll (sdla_t* card);
static void poll_active (sdla_t* card);
static void poll_connecting (sdla_t* card);
static void poll_disconnected (sdla_t* card);

/* Miscellaneous functions */
static int config502 (sdla_t* card);
static int config508 (sdla_t* card);
static void show_disc_cause (sdla_t* card, unsigned cause);
static unsigned char bps_to_speed_code (unsigned long bps);
static int reply_udp( unsigned char *data, unsigned int mbox_len );
static int process_udp_mgmt_pkt(char udp_pkt_src, sdla_t* card, struct sk_buff *skb, struct device* dev, ppp_private_area_t* ppp_priv_area);
static int process_udp_driver_call(char udp_pkt_src, sdla_t* card, struct sk_buff *skb, struct device* dev, ppp_private_area_t* ppp_priv_area); 
static void init_ppp_tx_rx_buff( sdla_t* card );
static int intr_test( sdla_t* card );
static int udp_pkt_type( struct sk_buff *skb , sdla_t* card);
static void init_ppp_priv_struct( ppp_private_area_t* ppp_priv_area);
static void init_global_statistics( sdla_t* card );

static int  Intr_test_counter;
static char TracingEnabled;
static unsigned long curr_trace_addr;
static unsigned long start_trace_addr;
static unsigned short available_buffer_space;

/* IPX functions */
static void switch_net_numbers(unsigned char *sendpacket, unsigned long network_number, unsigned char incoming);
static int handle_IPXWAN(unsigned char *sendpacket, char *devname, unsigned char enable_IPX, unsigned long network_number, unsigned short proto);
/****** Public Functions ****************************************************/

/*============================================================================
 * PPP protocol initialization routine.
 *
 * This routine is called by the main WANPIPE module during setup.  At this
 * point adapter is completely initialized and firmware is running.
 *  o read firmware version (to make sure it's alive)
 *  o configure adapter
 *  o initialize protocol-specific fields of the adapter data space.
 *
 * Return:	0	o.k.
 *		< 0	failure.
 */
int wpp_init (sdla_t* card, wandev_conf_t* conf)
{
	union
	{
		char str[80];
	} u;

	/* Verify configuration ID */
	if (conf->config_id != WANCONFIG_PPP) {
		
		printk(KERN_INFO "%s: invalid configuration ID %u!\n",
			card->devname, conf->config_id);
		return -EINVAL;

	}

	/* Initialize protocol-specific fields */
	switch (card->hw.fwid) {

		case SFID_PPP502:
			card->mbox =(void*)(card->hw.dpmbase + PPP502_MB_OFFS);
			card->flags=(void*)(card->hw.dpmbase + PPP502_FLG_OFFS);
			break;

		case SFID_PPP508:
			card->mbox =(void*)(card->hw.dpmbase + PPP508_MB_OFFS);
			card->flags=(void*)(card->hw.dpmbase + PPP508_FLG_OFFS);
			break;

		default:
			return -EINVAL;

	}

	/* Read firmware version.  Note that when adapter initializes, it
	 * clears the mailbox, so it may appear that the first command was
	 * executed successfully when in fact it was merely erased. To work
	 * around this, we execute the first command twice.
	 */
	if (ppp_read_version(card, NULL) || ppp_read_version(card, u.str))
		return -EIO;
	
	printk(KERN_INFO "%s: running PPP firmware v%s\n",card->devname, u.str); 
	/* Adjust configuration and set defaults */
	card->wandev.mtu = (conf->mtu) ?
		min(conf->mtu, PPP_MAX_MTU) : PPP_DFLT_MTU;

	card->wandev.bps	= conf->bps;
	card->wandev.interface	= conf->interface;
	card->wandev.clocking	= conf->clocking;
	card->wandev.station	= conf->station;
	card->isr		= &wpp_isr;
	card->poll		= &wpp_poll;
	card->exec		= &wpp_exec;
	card->wandev.update	= &update;
	card->wandev.new_if	= &new_if;
	card->wandev.del_if	= &del_if;
	card->wandev.state	= WAN_DISCONNECTED;
        card->wandev.udp_port   = conf->udp_port;
	card->wandev.ttl	= conf->ttl;
	card->irq_dis_if_send_count = 0;
        card->irq_dis_poll_count = 0;
        TracingEnabled          = 0;

	card->wandev.enable_IPX = conf->enable_IPX;
	if (conf->network_number)
		card->wandev.network_number = conf->network_number;
	else
		card->wandev.network_number = 0xDEADBEEF;

	/* initialize global statistics */
	init_global_statistics( card );

	return 0;
}

/******* WAN Device Driver Entry Points *************************************/

/*============================================================================
 * Update device status & statistics.
 */
static int update(wan_device_t * wandev)
{
	sdla_t *card;

	/* sanity checks */
	if ((wandev == NULL) || (wandev->private == NULL))
		return -EFAULT
		    ;
	if (wandev->state == WAN_UNCONFIGURED)
		return -ENODEV
		    ;
	if (test_and_set_bit(0, (void *) &wandev->critical))
		return -EAGAIN
		    ;
	card = wandev->private;

	ppp_get_err_stats(card);
	wandev->critical = 0;
	return 0;
}

/*============================================================================
 * Create new logical channel.
 * This routine is called by the router when ROUTER_IFNEW IOCTL is being
 * handled.
 * o parse media- and hardware-specific configuration
 * o make sure that a new channel can be created
 * o allocate resources, if necessary
 * o prepare network device structure for registaration.
 *
 * Return:	0	o.k.
 *		< 0	failure (channel will not be created)
 */
static int new_if (wan_device_t* wandev, struct device* dev, wanif_conf_t* conf)
{
	sdla_t* card = wandev->private;
	ppp_private_area_t* ppp_priv_area;

	if (wandev->ndev)
		return -EEXIST;
	
	if ((conf->name[0] == '\0') || (strlen(conf->name) > WAN_IFNAME_SZ)) {

		printk(KERN_INFO "%s: invalid interface name!\n",
			card->devname);
		return -EINVAL;

	}

	/* allocate and initialize private data */
	ppp_priv_area = kmalloc(sizeof(ppp_private_area_t), GFP_KERNEL);
	
	if( ppp_priv_area == NULL )
		return	-ENOMEM;
	
	memset(ppp_priv_area, 0, sizeof(ppp_private_area_t));
	
	ppp_priv_area->card = card; 
	
	/* initialize data */
	strcpy(card->u.p.if_name, conf->name);

	/* initialize data in ppp_private_area structure */
	
	init_ppp_priv_struct( ppp_priv_area );

	ppp_priv_area->mc = conf->mc;

	/* prepare network device data space for registration */
	dev->name = card->u.p.if_name;
	dev->init = &if_init;
	dev->priv = ppp_priv_area;
	return 0;
}

/*============================================================================
 * Delete logical channel.
 */
static int del_if (wan_device_t* wandev, struct device* dev)
{
	if (dev->priv) {

                kfree(dev->priv);
                dev->priv = NULL;
        }

	return 0;
}

/****** WANPIPE-specific entry points ***************************************/

/*============================================================================
 * Execute adapter interface command.
 */
static int wpp_exec(struct sdla *card, void *u_cmd, void *u_data)
{
	ppp_mbox_t *mbox = card->mbox;
	int len;

	if (copy_from_user((void *) &mbox->cmd, u_cmd, sizeof(ppp_cmd_t)))
		return -EFAULT;
	len = mbox->cmd.length;
	if (len) {
		if (copy_from_user((void *) &mbox->data, u_data, len))
			return -EFAULT;
	}
	/* execute command */
	if (!sdla_exec(mbox))
		return -EIO;

	/* return result */
	if (copy_to_user(u_cmd, (void *) &mbox->cmd, sizeof(ppp_cmd_t)))
		return -EFAULT;
	len = mbox->cmd.length;
	if (len && u_data && copy_to_user(u_data, (void *) &mbox->data, len))
		return -EFAULT;
	return 0;
}

/****** Network Device Interface ********************************************/

/*============================================================================
 * Initialize Linux network interface.
 *
 * This routine is called only once for each interface, during Linux network
 * interface registration.  Returning anything but zero will fail interface
 * registration.
 */
static int if_init (struct device* dev)
{
	ppp_private_area_t* ppp_priv_area = dev->priv;
	sdla_t* card = ppp_priv_area->card;
	wan_device_t* wandev = &card->wandev;
	int i;

	/* Initialize device driver entry points */
	dev->open		= &if_open;
	dev->stop		= &if_close;
	dev->hard_header	= &if_header;
	dev->rebuild_header	= &if_rebuild_hdr;
	dev->hard_start_xmit	= &if_send;
	dev->get_stats		= &if_stats;


	/* Initialize media-specific parameters */
	dev->family		= AF_INET;	/* address family */
	dev->type		= ARPHRD_PPP;	/* ARP h/w type */
	dev->mtu		= wandev->mtu;
	dev->hard_header_len	= PPP_HDR_LEN;	/* media header length */

	/* Initialize hardware parameters (just for reference) */
	dev->irq		= wandev->irq;
	dev->dma		= wandev->dma;
	dev->base_addr		= wandev->ioport;
	dev->mem_start		= wandev->maddr;
	dev->mem_end		= wandev->maddr + wandev->msize - 1;

        /* Set transmit buffer queue length */
        dev->tx_queue_len = 100;
   
	/* Initialize socket buffers */
	dev_init_buffers(dev);

	return 0;
}

/*============================================================================
 * Open network interface.
 * o enable communications and interrupts.
 * o prevent module from unloading by incrementing use count
 *
 * Return 0 if O.k. or errno.
 */
static int if_open (struct device* dev)
{
	ppp_private_area_t* ppp_priv_area = dev->priv;
	sdla_t* card = ppp_priv_area->card;
	ppp_flags_t* flags = card->flags;
	struct timeval tv;
	int err = 0;

	if (dev->start)
		return -EBUSY;		/* only one open is allowed */
	
	if (test_and_set_bit(0, (void*)&card->wandev.critical))
		return -EAGAIN;
	
	if ((card->hw.fwid == SFID_PPP502) ? config502(card) : config508(card)){

		err = -EIO;
		card->wandev.critical = 0;
		return err;

	}

	Intr_test_counter = 0;
	err = intr_test( card );

	if( (err) || (Intr_test_counter != (MAX_INTR_TEST_COUNTER + 1))) {

		printk(KERN_INFO "%s: Interrupt Test Failed, Counter: %i\n", 
			card->devname, Intr_test_counter);
		err = -EIO;
		card->wandev.critical = 0;
		return err;

	}
	
	printk(KERN_INFO "%s: Interrupt Test Passed, Counter: %i\n", 
		card->devname, Intr_test_counter);
	
	/* Initialize Rx/Tx buffer control fields */
	init_ppp_tx_rx_buff( card );

	if (ppp_set_intr_mode(card, 0x03)) {
	
		err = -EIO;
		card->wandev.critical = 0;
		return err;

	}

	flags->imask &= ~0x02;

	if (ppp_comm_enable(card)) {

		err = -EIO;
		card->wandev.critical = 0;
		return err;

	}
	
	wanpipe_set_state(card, WAN_CONNECTING);
	wanpipe_open(card);
	dev->mtu = min(dev->mtu, card->wandev.mtu);
	dev->interrupt = 0;
	dev->tbusy = 0;
	dev->start = 1;
	do_gettimeofday( &tv );
	ppp_priv_area->router_start_time = tv.tv_sec;
	card->wandev.critical = 0;
	return err;
}

/*============================================================================
 * Close network interface.
 * o if this is the last open, then disable communications and interrupts.
 * o reset flags.
 */
static int if_close (struct device* dev)
{
	ppp_private_area_t* ppp_priv_area = dev->priv;
	sdla_t* card = ppp_priv_area->card;

	if (test_and_set_bit(0, (void*)&card->wandev.critical))
		return -EAGAIN;
	
	dev->start = 0;
	wanpipe_close(card);
	wanpipe_set_state(card, WAN_DISCONNECTED);
	ppp_set_intr_mode(card, 0);
	ppp_comm_disable(card);
	card->wandev.critical = 0;
	return 0;
}

/*============================================================================
 * Build media header.
 *
 * The trick here is to put packet type (Ethertype) into 'protocol' field of
 * the socket buffer, so that we don't forget it.  If packet type is not
 * supported, set skb->protocol to 0 and discard packet later.
 *
 * Return:	media header length.
 */
static int if_header (struct sk_buff* skb, struct device* dev,
	unsigned short type, void* daddr, void* saddr, unsigned len)
{
	switch (type)
	{
		case ETH_P_IP:
	
		case ETH_P_IPX:
			skb->protocol = type;
			break;

		default:
			skb->protocol = 0;
	}

	return PPP_HDR_LEN;
}

/*============================================================================
 * Re-build media header.
 *
 * Return:	1	physical address resolved.
 *		0	physical address not resolved
 */
static int if_rebuild_hdr (struct sk_buff* skb)
{
	ppp_private_area_t* ppp_priv_area = skb->dev->priv;
	sdla_t* card = ppp_priv_area->card;

	printk(KERN_INFO "%s: rebuild_header() called for interface %s!\n",
		card->devname, dev->name);
	return 1;
}

/*============================================================================
 * Send a packet on a network interface.
 * o set tbusy flag (marks start of the transmission) to block a timer-based
 *   transmit from overlapping.
 * o check link state. If link is not up, then drop the packet.
 * o execute adapter send command.
 * o free socket buffer
 *
 * Return:	0	complete (socket buffer must be freed)
 *		non-0	packet may be re-transmitted (tbusy must be set)
 *
 * Notes:
 * 1. This routine is called either by the protocol stack or by the "net
 *    bottom half" (with interrupts enabled).
 * 2. Setting tbusy flag will inhibit further transmit requests from the
 *    protocol stack and can be used for flow control with protocol layer.
 */
static int if_send (struct sk_buff* skb, struct device* dev)
{
	ppp_private_area_t* ppp_priv_area = dev->priv;
	sdla_t* card = ppp_priv_area->card;
	unsigned char *sendpacket;
	unsigned long check_braddr, check_mcaddr;
	unsigned long host_cpu_flags;
	ppp_flags_t* flags = card->flags;
	int retry = 0;
	int err, udp_type;

	++ppp_priv_area->if_send_entry;

	if (skb == NULL) {

		/* If we get here, some higher layer thinks we've missed an
		 * tx-done interrupt.
		 */
		printk(KERN_INFO "%s: interface %s got kicked!\n",
			card->devname, dev->name);
		
		++ppp_priv_area->if_send_skb_null;
		
		dev_tint(dev);
		return 0;

	}

	if (dev->tbusy) {

		/* If our device stays busy for at least 5 seconds then we will
		 * kick start the device by making dev->tbusy = 0.  We expect 
		 * that our device never stays busy more than 5 seconds. So this
		 * is only used as a last resort. 
		 */
              
		++ppp_priv_area->if_send_busy;
        	++card->wandev.stats.collisions;

		if ((jiffies - ppp_priv_area->tick_counter) < (5*HZ)) {
			return 1;
		}

		printk (KERN_INFO "%s: Transmit times out\n",card->devname);
	
		++ppp_priv_area->if_send_busy_timeout;

		/* unbusy the card (because only one interface per card)*/
		dev->tbusy = 0;
	}	
	sendpacket = skb->data;
#ifdef CONFIG_SANGOMA_MANAGER
	if(sangoma_ppp_manager(skb,card))
	{
		dev_kfree_skb(skb);
		return 0;
	}
#endif
	disable_irq(card->hw.irq);
	++card->irq_dis_if_send_count;

    	if (test_and_set_bit(0, (void*)&card->wandev.critical)) 
    	{
    		if (card->wandev.critical == CRITICAL_IN_ISR) 
    		{	
			/* If the critical flag is set due to an Interrupt
			 * then set enable transmit interrupt flag to enable
			 * transmit interrupt. (delay interrupt)
			 */
			card->wandev.enable_tx_int = 1;
	   		dev->tbusy = 1;
			
			/* set the counter to see if we get the interrupt in
			 * 5 seconds. 
			 */
			ppp_priv_area->tick_counter = jiffies;
	   		++ppp_priv_area->if_send_critical_ISR;
			
			save_flags(host_cpu_flags);
                        cli();
                        if ((!(--card->irq_dis_if_send_count)) &&
                                        (!card->irq_dis_poll_count))
                                enable_irq(card->hw.irq);
                        restore_flags(host_cpu_flags);

			return 1;

		}

    		dev_kfree_skb(skb);
		++ppp_priv_area->if_send_critical_non_ISR;
		
		save_flags(host_cpu_flags);
                cli();
                if ((!(--card->irq_dis_if_send_count)) &&
                                         (!card->irq_dis_poll_count))
                        enable_irq(card->hw.irq);
                restore_flags(host_cpu_flags);
	
		return 0;
	}


	if (card->wandev.state != WAN_CONNECTED) {

		++ppp_priv_area->if_send_wan_disconnected;
        	++card->wandev.stats.tx_dropped;

     	} else if (!skb->protocol) {
		++ppp_priv_area->if_send_protocol_error;
        	++card->wandev.stats.tx_errors;

	} else {

		/*If it's IPX change the network numbers to 0 if they're ours.*/
		if( skb->protocol == ETH_P_IPX ) {
			if(card->wandev.enable_IPX) {
				switch_net_numbers( skb->data, 
					card->wandev.network_number, 0);
			} else {
				++card->wandev.stats.tx_dropped;
				goto tx_done;
			}
		}

		if (ppp_send(card, skb->data, skb->len, skb->protocol)) {

			retry = 1;
			dev->tbusy = 1;
			++ppp_priv_area->if_send_adptr_bfrs_full;
			++ppp_priv_area->if_send_tx_int_enabled;
			ppp_priv_area->tick_counter = jiffies;
			++card->wandev.stats.tx_errors;
			flags->imask |= 0x02;	/* unmask Tx interrupts */

		} else {
			++ppp_priv_area->if_send_bfr_passed_to_adptr;
			++card->wandev.stats.tx_packets;
		}
    	}
	
tx_done:	
	if (!retry){
		dev_kfree_skb(skb);
	}

	card->wandev.critical = 0;
	
	save_flags(host_cpu_flags);
        cli();
        if ((!(--card->irq_dis_if_send_count)) && (!card->irq_dis_poll_count))
                enable_irq(card->hw.irq);
        restore_flags(host_cpu_flags);
	
	return retry;
}

/*
   If incoming is 0 (outgoing)- if the net numbers is ours make it 0
   if incoming is 1 - if the net number is 0 make it ours 

*/
static void switch_net_numbers(unsigned char *sendpacket, unsigned long network_number, unsigned char incoming)
{
	unsigned long pnetwork_number;

	pnetwork_number = (unsigned long)((sendpacket[6] << 24) + 
			  (sendpacket[7] << 16) + (sendpacket[8] << 8) + 
			  sendpacket[9]);

	if (!incoming) 
	{
		/* If the destination network number is ours, make it 0 */
		if( pnetwork_number == network_number) 
		{
			sendpacket[6] = sendpacket[7] = sendpacket[8] = 
					 sendpacket[9] = 0x00;
		}
	} 
	else
	{
		/* If the incoming network is 0, make it ours */
		if( pnetwork_number == 0) 
		{
			sendpacket[6] = (unsigned char)(network_number >> 24);
			sendpacket[7] = (unsigned char)((network_number & 
					 0x00FF0000) >> 16);
			sendpacket[8] = (unsigned char)((network_number & 
					 0x0000FF00) >> 8);
			sendpacket[9] = (unsigned char)(network_number & 
					 0x000000FF);
		}
	}


	pnetwork_number = (unsigned long)((sendpacket[18] << 24) + 
			  (sendpacket[19] << 16) + (sendpacket[20] << 8) + 
			  sendpacket[21]);

	if( !incoming ) 
	{
		/* If the source network is ours, make it 0 */
		if( pnetwork_number == network_number) 
		{
			sendpacket[18] = sendpacket[19] = sendpacket[20] = 
					 sendpacket[21] = 0x00;
		}
	} 
	else
	{
		/* If the source network is 0, make it ours */
		if( pnetwork_number == 0 ) 
		{
			sendpacket[18] = (unsigned char)(network_number >> 24);
			sendpacket[19] = (unsigned char)((network_number & 
					 0x00FF0000) >> 16);
			sendpacket[20] = (unsigned char)((network_number & 
					 0x0000FF00) >> 8);
			sendpacket[21] = (unsigned char)(network_number & 
					 0x000000FF);
		}
	}
} /* switch_net_numbers */

/*============================================================================
 * Get ethernet-style interface statistics.
 * Return a pointer to struct enet_statistics.
 */
static struct net_device_stats* if_stats (struct device* dev)
{
	ppp_private_area_t* ppp_priv_area = dev->priv;
	sdla_t* card = ppp_priv_area->card;

	return &card->wandev.stats;
}

/****** PPP Firmware Interface Functions ************************************/

/*============================================================================
 * Read firmware code version.
 *	Put code version as ASCII string in str. 
 */
static int ppp_read_version (sdla_t* card, char* str)
{
	ppp_mbox_t* mb = card->mbox;
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	mb->cmd.command = PPP_READ_CODE_VERSION;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;

	if (err != CMD_OK)
 
		ppp_error(card, err, mb);

	else if (str) {

		int len = mb->cmd.length;

		memcpy(str, mb->data, len);
		str[len] = '\0';

	}

	return err;
}

/*============================================================================
 * Configure PPP firmware.
 */
static int ppp_configure (sdla_t* card, void* data)
{
	ppp_mbox_t* mb = card->mbox;
	int data_len = (card->hw.fwid == SFID_PPP502) ?
		sizeof(ppp502_conf_t) : sizeof(ppp508_conf_t);
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	memcpy(mb->data, data, data_len);
	mb->cmd.length  = data_len;
	mb->cmd.command = PPP_SET_CONFIG;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
	
	if (err != CMD_OK) 
		ppp_error(card, err, mb);
	
	return err;
}

/*============================================================================
 * Set interrupt mode.
 */
static int ppp_set_intr_mode (sdla_t* card, unsigned mode)
{
	ppp_mbox_t* mb = card->mbox;
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	mb->data[0] = mode;
	
	switch (card->hw.fwid)
	{
		case SFID_PPP502:
			mb->cmd.length  = 1;
			break;

		case SFID_PPP508:
		
		default:
			mb->data[1] = card->hw.irq;
			mb->cmd.length = 2;
	}
	
	mb->cmd.command = PPP_SET_INTR_FLAGS;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
	
	if (err != CMD_OK) 
		ppp_error(card, err, mb);
	
	return err;
}

/*============================================================================
 * Enable communications.
 */
static int ppp_comm_enable (sdla_t* card)
{
	ppp_mbox_t* mb = card->mbox;
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	mb->cmd.command = PPP_COMM_ENABLE;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
	
	if (err != CMD_OK) 
		ppp_error(card, err, mb);
	
	return err;
}

/*============================================================================
 * Disable communications.
 */
static int ppp_comm_disable (sdla_t* card)
{
	ppp_mbox_t* mb = card->mbox;
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	mb->cmd.command = PPP_COMM_DISABLE;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
	
	if (err != CMD_OK) 
		ppp_error(card, err, mb);
	
	return err;
}

/*============================================================================
 * Get communications error statistics.
 */
static int ppp_get_err_stats (sdla_t* card)
{
	ppp_mbox_t* mb = card->mbox;
	int err;

	memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
	mb->cmd.command = PPP_READ_ERROR_STATS;
	err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
	
	if (err == CMD_OK) 
	{	
		ppp_err_stats_t* stats = (void*)mb->data;
		card->wandev.stats.rx_over_errors    = stats->rx_overrun;
		card->wandev.stats.rx_crc_errors     = stats->rx_bad_crc;
		card->wandev.stats.rx_missed_errors  = stats->rx_abort;
		card->wandev.stats.rx_length_errors  = stats->rx_lost;
		card->wandev.stats.tx_aborted_errors = stats->tx_abort;
	
	} else 
		ppp_error(card, err, mb);
	
	return err;
}

/*============================================================================
 * Send packet.
 *	Return:	0 - o.k.
 *		1 - no transmit buffers available
 */
 
static int ppp_send (sdla_t* card, void* data, unsigned len, unsigned proto)
{
	ppp_buf_ctl_t* txbuf = card->u.p.txbuf;
	unsigned long addr;

	if (txbuf->flag)
                return 1;
	
	if (card->hw.fwid == SFID_PPP502)
		addr = (txbuf->buf.o_p[1] << 8) + txbuf->buf.o_p[0]; 
	else 
		addr = txbuf->buf.ptr;

	
	sdla_poke(&card->hw, addr, data, len);

	txbuf->length = len;		/* frame length */
	
	if (proto == ETH_P_IPX)
		txbuf->proto = 0x01;	/* protocol ID */
	
	txbuf->flag = 1;		/* start transmission */

	/* Update transmit buffer control fields */
	card->u.p.txbuf = ++txbuf;

	if ((void*)txbuf > card->u.p.txbuf_last)
		card->u.p.txbuf = card->u.p.txbuf_base;

	return 0;
}

/****** Firmware Error Handler **********************************************/

/*============================================================================
 * Firmware error handler.
 *	This routine is called whenever firmware command returns non-zero
 *	return code.
 *
 * Return zero if previous command has to be cancelled.
 */
 
static int ppp_error (sdla_t *card, int err, ppp_mbox_t* mb)
{
	unsigned cmd = mb->cmd.command;

	switch (err) 
	{
		case CMD_TIMEOUT:
			printk(KERN_ERR "%s: command 0x%02X timed out!\n",
				card->devname, cmd);
			break;

		default:
			printk(KERN_INFO "%s: command 0x%02X returned 0x%02X!\n"
				, card->devname, cmd, err);
	}

	return 0;
}

/****** Interrupt Handlers **************************************************/

/*============================================================================
 * PPP interrupt service routine.
 */
STATIC void wpp_isr (sdla_t* card)
{
	ppp_flags_t* flags = card->flags;
	char *ptr = &flags->iflag;
	unsigned long host_cpu_flags;
	struct device* dev = card->wandev.dev;
	int i;
	
	card->in_isr = 1;
	
	++card->statistics.isr_entry;

	if (set_bit(0, (void*)&card->wandev.critical)) {
        	
		++card->statistics.isr_already_critical;
		printk (KERN_INFO "%s: Critical while in ISR!\n",card->devname);
		card->in_isr = 0;
		return;
	
	}

	/* For all interrupts set the critical flag to CRITICAL_IN_ISR. 
	 * If the if_send routine is called with this flag set it will set 
	 * the enable transmit flag to 1. (for a delayed interrupt) 
	 */
	card->wandev.critical = CRITICAL_IN_ISR;

	card->buff_int_mode_unbusy = 0;

	switch (flags->iflag) {

		case 0x01:	/* receive interrupt */
			++card->statistics.isr_rx;
			rx_intr(card);
			break;

		case 0x02:	/* transmit interrupt */
			++card->statistics.isr_tx;
			flags->imask &= ~0x02;
			dev->tbusy = 0;		
			card->buff_int_mode_unbusy = 1;
			break;

		case 0x08:
			++Intr_test_counter;
			++card->statistics.isr_intr_test;
			break;

		default:	/* unexpected interrupt */
			++card->statistics.isr_spurious;
			printk(KERN_INFO "%s: spurious interrupt 0x%02X!\n", 
				card->devname, flags->iflag);
			printk(KERN_INFO "%s: ID Bytes = ",card->devname);
	 		for(i = 0; i < 8; i ++)
				printk(KERN_INFO "0x%02X ", *(ptr + 0x28 + i));
			printk(KERN_INFO "\n");	
	}
	
	/* The critical flag is set to CRITICAL_INTR_HANDLED to let the
	 * if_send call know that the interrupt is handled so that 
	 * transmit interrupts are not enabled again.
	 */ 

	card->wandev.critical = CRITICAL_INTR_HANDLED;

	/* If the enable transmit interrupt flag is set then enable transmit 
	 * interrupt on the board. This only goes through if if_send is called 
	 * and the critical flag is set due to an Interrupt. 
	 */
	if(card->wandev.enable_tx_int) {

		flags->imask |= 0x02;
		card->wandev.enable_tx_int = 0;
		++card->statistics.isr_enable_tx_int;
	
	}
	save_flags(host_cpu_flags);
	cli();
	card->in_isr = 0;
	flags->iflag = 0;
	card->wandev.critical = 0;
	restore_flags(host_cpu_flags);

	if(card->buff_int_mode_unbusy)	
		mark_bh(NET_BH);
	
}

/*============================================================================
 * Receive interrupt handler.
 */
static void rx_intr (sdla_t* card)
{
	ppp_buf_ctl_t* rxbuf = card->rxmb;
	struct device* dev = card->wandev.dev;
	ppp_private_area_t* ppp_priv_area;
	struct sk_buff* skb;
	unsigned len;
	void* buf;
	int i, err;
        ppp_flags_t* flags = card->flags;
        char *ptr = &flags->iflag;
	int udp_type;
	

	if (rxbuf->flag != 0x01) {
	

		printk(KERN_INFO 
			"%s: corrupted Rx buffer @ 0x%X, flag = 0x%02X!\n", 
			card->devname, (unsigned)rxbuf, rxbuf->flag);
	
		printk(KERN_INFO "%s: ID Bytes = ",card->devname);
	 	
		for(i = 0; i < 8; i ++)
			printk(KERN_INFO "0x%02X ", *(ptr + 0x28 + i));
		printk(KERN_INFO "\n");	
		
		++card->statistics.rx_intr_corrupt_rx_bfr;
		return;

	}
	

	if (dev && dev->start) {
	
		len  = rxbuf->length;
		ppp_priv_area = dev->priv;

		/* Allocate socket buffer */
		skb = dev_alloc_skb(len);

		if (skb != NULL) {
		
			/* Copy data to the socket buffer */
			if (card->hw.fwid == SFID_PPP502) {
		
				unsigned addr = (rxbuf->buf.o_p[1] << 8) + 
						rxbuf->buf.o_p[0]; 
				buf = skb_put(skb, len);
				sdla_peek(&card->hw, addr, buf, len);

			} else {
		
				unsigned addr = rxbuf->buf.ptr;

				if ((addr + len) > card->u.p.rx_top + 1) {
			
					unsigned tmp = card->u.p.rx_top - addr 
							+ 1;
					buf = skb_put(skb, tmp);
					sdla_peek(&card->hw, addr, buf, tmp);
					addr = card->u.p.rx_base;
					len -= tmp;

				}
		
				buf = skb_put(skb, len);
				sdla_peek(&card->hw, addr, buf, len);
			}

			/* Decapsulate packet */
        		switch (rxbuf->proto) {
	
				case 0x00:
					skb->protocol = htons(ETH_P_IP);
					break;

				case 0x01:
					skb->protocol = htons(ETH_P_IPX);
					break;
			}
#ifdef CONFIG_SANGOMA_MANAGER
			udp_type = udp_pkt_type( skb, card );

			if (udp_type == UDP_DRVSTATS_TYPE){ 
				++ppp_priv_area->rx_intr_DRVSTATS_request; 
				process_udp_driver_call(
					UDP_PKT_FRM_NETWORK, card, skb,
					dev, ppp_priv_area);
                                 dev_kfree_skb(skb);

			} else if (udp_type == UDP_PTPIPE_TYPE){
				++ppp_priv_area->rx_intr_PTPIPE_request;
				err = process_udp_mgmt_pkt(
					UDP_PKT_FRM_NETWORK, card, 
					skb, dev, ppp_priv_area);
				dev_kfree_skb(skb);
			} else
#endif
				if (handle_IPXWAN(skb->data,card->devname, card->wandev.enable_IPX, card->wandev.network_number, skb->protocol)) {
				
				if( card->wandev.enable_IPX) {
					ppp_send(card, skb->data, skb->len, ETH_P_IPX);
                        		dev_kfree_skb(skb);

				} else {
					++card->wandev.stats.rx_dropped;
				}
			} else {
				/* Pass it up the protocol stack */
	    			skb->dev = dev;
				skb->mac.raw  = skb->data;
	    			netif_rx(skb);
			    	++card->wandev.stats.rx_packets;
		    		++ppp_priv_area->rx_intr_bfr_passed_to_stack;	
			}

		} else {
		
			printk(KERN_INFO "%s: no socket buffers available!\n",
				card->devname);
			++card->wandev.stats.rx_dropped;
			++ppp_priv_area->rx_intr_no_socket;

		}

	} else
		++card->statistics.rx_intr_dev_not_started;

	/* Release buffer element and calculate a pointer to the next one */
	rxbuf->flag = (card->hw.fwid == SFID_PPP502) ? 0xFF : 0x00;
	card->rxmb = ++rxbuf;
	
	if ((void*)rxbuf > card->u.p.rxbuf_last)
		card->rxmb = card->u.p.rxbuf_base;
}

/*============================================================================
 * Transmit interrupt handler.
 */
static void tx_intr (sdla_t* card)
{
	struct device* dev = card->wandev.dev;

	if (!dev || !dev->start) 
	{
		++card->statistics.tx_intr_dev_not_started;
        	return;
     	}

	dev->tbusy = 0;
	dev_tint(dev);
}

static int handle_IPXWAN(unsigned char *sendpacket, char *devname, unsigned char enable_IPX, unsigned long network_number, unsigned short proto)
{
	int i;

	if( proto == htons(ETH_P_IPX) ) 
	{
		/* It's an IPX packet */
		if(!enable_IPX) 
		{
			//Return 1 so we don't pass it up the stack.
			return 1;
		}
	}
	else
	{
		/* It's not IPX so pass it up the stack. */
		return 0;
	}

	if( sendpacket[16] == 0x90 &&
	    sendpacket[17] == 0x04)
	{
		/* It's IPXWAN */

		if( sendpacket[2] == 0x02 &&
		    sendpacket[34] == 0x00)
		{
			/* It's a timer request packet */
			printk(KERN_INFO "%s: Received IPXWAN Timer Request packet\n",devname);

			/* Go through the routing options and answer no to every */
			/* option except Unnumbered RIP/SAP */
			for(i = 41; sendpacket[i] == 0x00; i += 5)
			{
				/* 0x02 is the option for Unnumbered RIP/SAP */
				if( sendpacket[i + 4] != 0x02)
				{
					sendpacket[i + 1] = 0;
				}
			}

			/* Skip over the extended Node ID option */
			if( sendpacket[i] == 0x04 )
			{
				i += 8;
			}

			/* We also want to turn off all header compression opt. */
			for(; sendpacket[i] == 0x80 ;)
			{
				sendpacket[i + 1] = 0;
				i += (sendpacket[i + 2] << 8) + (sendpacket[i + 3]) + 4;
			}

			/* Set the packet type to timer response */
			sendpacket[34] = 0x01;

			printk(KERN_INFO "%s: Sending IPXWAN Timer Response\n",devname);
		}
		else if( sendpacket[34] == 0x02 )
		{
			/* This is an information request packet */
			printk(KERN_INFO "%s: Received IPXWAN Information Request packet\n",devname);

			/* Set the packet type to information response */
			sendpacket[34] = 0x03;

			/* Set the router name */
			sendpacket[51] = 'P';
			sendpacket[52] = 'T';
			sendpacket[53] = 'P';
			sendpacket[54] = 'I';
			sendpacket[55] = 'P';
			sendpacket[56] = 'E';
			sendpacket[57] = '-';
			sendpacket[58] = CVHexToAscii(network_number >> 28);
			sendpacket[59] = CVHexToAscii((network_number & 0x0F000000)>> 24);
			sendpacket[60] = CVHexToAscii((network_number & 0x00F00000)>> 20);
			sendpacket[61] = CVHexToAscii((network_number & 0x000F0000)>> 16);
			sendpacket[62] = CVHexToAscii((network_number & 0x0000F000)>> 12);
			sendpacket[63] = CVHexToAscii((network_number & 0x00000F00)>> 8);
			sendpacket[64] = CVHexToAscii((network_number & 0x000000F0)>> 4);
			sendpacket[65] = CVHexToAscii(network_number & 0x0000000F);
			for(i = 66; i < 99; i+= 1)
			{
				sendpacket[i] = 0;
			}

			printk(KERN_INFO "%s: Sending IPXWAN Information Response packet\n",devname);
		}
		else
		{
			printk(KERN_INFO "%s: Unknown IPXWAN packet!\n",devname);
			return 0;
		}

		/* Set the WNodeID to our network address */
		sendpacket[35] = (unsigned char)(network_number >> 24);
		sendpacket[36] = (unsigned char)((network_number & 0x00FF0000) >> 16);
		sendpacket[37] = (unsigned char)((network_number & 0x0000FF00) >> 8);
		sendpacket[38] = (unsigned char)(network_number & 0x000000FF);

		return 1;
	} else {
		/* If we get here's its an IPX-data packet, so it'll get passed up the stack. */

		/* switch the network numbers */
		switch_net_numbers(sendpacket, network_number, 1);	
		return 0;
	}
}

/****** Background Polling Routines  ****************************************/

/*============================================================================
 * Main polling routine.
 * This routine is repeatedly called by the WANPIPE 'thread' to allow for
 * time-dependent housekeeping work.
 *
 * Notes:
 * 1. This routine may be called on interrupt context with all interrupts
 *    enabled. Beware!
 */
static void wpp_poll (sdla_t* card)
{
	struct device* dev = card->wandev.dev;
	ppp_flags_t* adptr_flags = card->flags;
	unsigned long host_cpu_flags;

	++card->statistics.poll_entry;

	/* The wpp_poll is called continously by the WANPIPE thread to allow
	 * for line state housekeeping. However if we are in a connected state
	 * then we do not need to go through all the checks everytime. When in
	 * connected state execute wpp_poll once every second.
	 */

	if (card->wandev.state == WAN_CONNECTED)
	{ 	
		if ((jiffies - card->state_tick) < HZ )
         		return;
	}

 	disable_irq(card->hw.irq);
  	++card->irq_dis_poll_count; 

	if (set_bit(0, (void *)&card->wandev.critical)) 
	{
		++card->statistics.poll_already_critical;
		printk(KERN_INFO "%s: critical inside wpp_poll\n", 
			card->devname);
		save_flags(host_cpu_flags);
                cli();
                if ((!card->irq_dis_if_send_count) &&
                                (!(--card->irq_dis_poll_count)))
                        enable_irq(card->hw.irq);
                restore_flags(host_cpu_flags);

		return;
	}

   	++card->statistics.poll_processed;
    	
    	if (dev && dev->tbusy && !(adptr_flags->imask & 0x02)) 
    	{	
		++card->statistics.poll_tbusy_bad_status;
		printk(KERN_INFO "%s: Wpp_Poll: tbusy = 0x01, imask = 0x%02X\n"
			, card->devname, adptr_flags->imask);
    	}

	switch(card->wandev.state)
	{
		case WAN_CONNECTED:
			card->state_tick = jiffies;
			poll_active(card);
			break;

		case WAN_CONNECTING:
			poll_connecting(card);
			break;

		case WAN_DISCONNECTED:
			poll_disconnected(card);
			break;

		default:
			printk(KERN_INFO "%s: Unknown Poll State 0x%02X\n", 
				card->devname, card->wandev.state);
			break;
	}

	card->wandev.critical = 0;
 	
	save_flags(host_cpu_flags);
        cli();
        if ((!card->irq_dis_if_send_count) && (!(--card->irq_dis_poll_count)))
                enable_irq(card->hw.irq);
        restore_flags(host_cpu_flags);

}

/*============================================================================
 * Monitor active link phase.
 */
static void poll_active (sdla_t* card)
{
	ppp_flags_t* flags = card->flags;

	/* We check the lcp_state to see if we are in DISCONNECTED state.
	 * We are considered to be connected for lcp states 0x06, 0x07, 0x08
	 * and 0x09.
	 */
	if ((flags->lcp_state <= 0x05) || (flags->disc_cause & 0x03)) {

		wanpipe_set_state(card, WAN_DISCONNECTED);
		show_disc_cause(card, flags->disc_cause);
	
	}
}

/*============================================================================
 * Monitor link establishment phase.
 * o if connection timed out, disconnect the link.
 */
static void poll_connecting (sdla_t* card)
{
	ppp_flags_t* flags = card->flags;
	
	if (flags->lcp_state == 0x09) 
	{
		wanpipe_set_state(card, WAN_CONNECTED);
	}
	else if (flags->disc_cause & 0x03)
	{	
		wanpipe_set_state(card, WAN_DISCONNECTED);
		show_disc_cause(card, flags->disc_cause);
	}
}

/*============================================================================
 * Monitor physical link disconnected phase.
 *  o if interface is up and the hold-down timeout has expired, then retry
 *    connection.
 */
static void poll_disconnected (sdla_t* card)
{
	struct device* dev = card->wandev.dev;

	if (dev && dev->start &&
	    ((jiffies - card->state_tick) > HOLD_DOWN_TIME)) 
	{	
		wanpipe_set_state(card, WAN_CONNECTING);	
		if(ppp_comm_enable(card) == CMD_OK)
			init_ppp_tx_rx_buff( card );
	}
}

/****** Miscellaneous Functions *********************************************/

/*============================================================================
 * Configure S502 adapter.
 */
static int config502 (sdla_t* card)
{
	ppp502_conf_t cfg;

	/* Prepare PPP configuration structure */
	memset(&cfg, 0, sizeof(ppp502_conf_t));

	if (card->wandev.clocking)
		cfg.line_speed = bps_to_speed_code(card->wandev.bps);
		
	cfg.txbuf_num		= 4;
	cfg.mtu_local		= card->wandev.mtu;
	cfg.mtu_remote		= card->wandev.mtu;
	cfg.restart_tmr		= 30;
	cfg.auth_rsrt_tmr	= 30;
	cfg.auth_wait_tmr	= 300;
	cfg.mdm_fail_tmr	= 5;
	cfg.dtr_drop_tmr	= 1;
	cfg.connect_tmout	= 0;	/* changed it from 900 */
	cfg.conf_retry		= 10;
	cfg.term_retry		= 2;
	cfg.fail_retry		= 5;
	cfg.auth_retry		= 10;
	cfg.ip_options		= 0x80;
	cfg.ipx_options		= 0xA0;
        cfg.conf_flags         |= 0x0E;
/*
	cfg.ip_local		= dev->pa_addr;
	cfg.ip_remote		= dev->pa_dstaddr;
*/
	return ppp_configure(card, &cfg);
}

/*============================================================================
 * Configure S508 adapter.
 */
static int config508 (sdla_t* card)
{
	ppp508_conf_t cfg;

	/* Prepare PPP configuration structure */
	memset(&cfg, 0, sizeof(ppp508_conf_t));

	if (card->wandev.clocking)
		cfg.line_speed = card->wandev.bps;

	if (card->wandev.interface == WANOPT_RS232)
		cfg.conf_flags |= 0x0020;

        cfg.conf_flags 	|= 0x300; /*send Configure-Request packets forever*/
	cfg.txbuf_percent	= 60;	/* % of Tx bufs */
	cfg.mtu_local		= card->wandev.mtu;
	cfg.mtu_remote		= card->wandev.mtu;
	cfg.restart_tmr		= 30;
	cfg.auth_rsrt_tmr	= 30;
	cfg.auth_wait_tmr	= 300;
	cfg.mdm_fail_tmr	= 100;
	cfg.dtr_drop_tmr	= 1;
	cfg.connect_tmout	= 0; 	/* changed it from 900 */
	cfg.conf_retry		= 10;
	cfg.term_retry		= 2;
	cfg.fail_retry		= 5;
	cfg.auth_retry		= 10;
	cfg.ip_options		= 0x80;
	cfg.ipx_options		= 0xA0;
/*
	cfg.ip_local		= dev->pa_addr;
	cfg.ip_remote		= dev->pa_dstaddr;
*/
	return ppp_configure(card, &cfg);
}

/*============================================================================
 * Show disconnection cause.
 */
static void show_disc_cause (sdla_t* card, unsigned cause)
{
	if (cause & 0x0002) 
		printk(KERN_INFO "%s: link terminated by peer\n", 
			card->devname);

	else if (cause & 0x0004) 
		printk(KERN_INFO "%s: link terminated by user\n", 
			card->devname);

	else if (cause & 0x0008) 
		printk(KERN_INFO "%s: authentication failed\n", card->devname);
	
	else if (cause & 0x0010)
		printk(KERN_INFO 
			"%s: authentication protocol negotiation failed\n", 
			card->devname);

	else if (cause & 0x0020) 
		printk(KERN_INFO
		"%s: peer's request for authentication rejected\n",
		card->devname);

	else if (cause & 0x0040) 
		printk(KERN_INFO "%s: MRU option rejected by peer\n", 
		card->devname);

	else if (cause & 0x0080) 
		printk(KERN_INFO "%s: peer's MRU was too small\n", 
		card->devname);

	else if (cause & 0x0100) 
		printk(KERN_INFO "%s: failed to negotiate peer's LCP options\n",
		card->devname);

	else if (cause & 0x0200) 
		printk(KERN_INFO "%s: failed to negotiate peer's IPCP options\n"
		, card->devname);

	else if (cause & 0x0400) 
		printk(KERN_INFO 
			"%s: failed to negotiate peer's IPXCP options\n",
			card->devname);
}

/*============================================================================
 * Convert line speed in bps to a number used by S502 code.
 */
static unsigned char bps_to_speed_code (unsigned long bps)
{
	unsigned char	number;

	if (bps <= 1200)        
		number = 0x01;
	else if (bps <= 2400)   
		number = 0x02;
	else if (bps <= 4800)   
		number = 0x03;
	else if (bps <= 9600)   
		number = 0x04;
	else if (bps <= 19200)  
		number = 0x05;
	else if (bps <= 38400)  
		number = 0x06;
	else if (bps <= 45000)  
		number = 0x07;
	else if (bps <= 56000)  
		number = 0x08;
	else if (bps <= 64000)  
		number = 0x09;
	else if (bps <= 74000)  
		number = 0x0A;
	else if (bps <= 112000) 	
		number = 0x0B;
	else if (bps <= 128000) 
		number = 0x0C;
	else 
		number = 0x0D;

	return number;
}

/*=============================================================================
 * Initial the ppp_private_area structure.
 */

static void init_ppp_priv_struct( ppp_private_area_t* ppp_priv_area )
{
	ppp_priv_area->if_send_entry 			= 0;
	ppp_priv_area->if_send_skb_null 		= 0;
	ppp_priv_area->if_send_broadcast 		= 0;
	ppp_priv_area->if_send_multicast 		= 0;
	ppp_priv_area->if_send_critical_ISR 		= 0;
	ppp_priv_area->if_send_critical_non_ISR 	= 0;
	ppp_priv_area->if_send_busy 			= 0;
	ppp_priv_area->if_send_busy_timeout 		= 0;
	ppp_priv_area->if_send_DRVSTATS_request		= 0;
	ppp_priv_area->if_send_PTPIPE_request 		= 0;
	ppp_priv_area->if_send_wan_disconnected 	= 0;
	ppp_priv_area->if_send_adptr_bfrs_full 		= 0;
	ppp_priv_area->if_send_bfr_passed_to_adptr 	= 0;
	
	ppp_priv_area->rx_intr_no_socket 		= 0;
	ppp_priv_area->rx_intr_DRVSTATS_request 	= 0;
	ppp_priv_area->rx_intr_PTPIPE_request 		= 0;
	ppp_priv_area->rx_intr_bfr_not_passed_to_stack 	= 0;
	ppp_priv_area->rx_intr_bfr_passed_to_stack 	= 0;

	ppp_priv_area->UDP_PTPIPE_mgmt_kmalloc_err 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_adptr_type_err 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_direction_err 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_adptr_cmnd_timeout	= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_adptr_cmnd_OK 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_passed_to_adptr 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_passed_to_stack 		= 0;
	ppp_priv_area->UDP_PTPIPE_mgmt_no_socket 		= 0; 	

	ppp_priv_area->UDP_DRVSTATS_mgmt_kmalloc_err 		= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_adptr_type_err 	= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_direction_err 		= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_adptr_cmnd_timeout	= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_adptr_cmnd_OK 		= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_passed_to_adptr 	= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_passed_to_stack 	= 0;
	ppp_priv_area->UDP_DRVSTATS_mgmt_no_socket 		= 0; 	
}

/*============================================================================
 * Initialize Global Statistics
 */
static void init_global_statistics( sdla_t* card )
{
	card->statistics.isr_entry 		= 0;
	card->statistics.isr_already_critical 	= 0;
	card->statistics.isr_tx 		= 0;
	card->statistics.isr_rx 		= 0;
	card->statistics.isr_intr_test		= 0;
	card->statistics.isr_spurious 		= 0;
	card->statistics.isr_enable_tx_int 	= 0;
	card->statistics.rx_intr_corrupt_rx_bfr = 0;
	card->statistics.rx_intr_dev_not_started= 0;
	card->statistics.tx_intr_dev_not_started= 0;
	card->statistics.poll_entry		= 0;
	card->statistics.poll_already_critical 	= 0;
	card->statistics.poll_processed 	= 0;
	card->statistics.poll_tbusy_bad_status 	= 0;

}

/*============================================================================
 * Initialize Receive and Transmit Buffers.
 */
static void init_ppp_tx_rx_buff( sdla_t* card )
{

	if (card->hw.fwid == SFID_PPP502) 
	{	
		ppp502_buf_info_t* info =
			(void*)(card->hw.dpmbase + PPP502_BUF_OFFS);

		card->u.p.txbuf_base = 
			(void*)(card->hw.dpmbase + info->txb_offs);

		card->u.p.txbuf_last = (ppp_buf_ctl_t*)card->u.p.txbuf_base +
			(info->txb_num - 1);

		card->u.p.rxbuf_base = 
			(void*)(card->hw.dpmbase + info->rxb_offs);

		card->u.p.rxbuf_last = (ppp_buf_ctl_t*)card->u.p.rxbuf_base +
			(info->rxb_num - 1);
	}
	else
	{	
		ppp508_buf_info_t* info =
			(void*)(card->hw.dpmbase + PPP508_BUF_OFFS);

		card->u.p.txbuf_base = (void*)(card->hw.dpmbase +
			(info->txb_ptr - PPP508_MB_VECT));

		card->u.p.txbuf_last = (ppp_buf_ctl_t*)card->u.p.txbuf_base +
			(info->txb_num - 1);

		card->u.p.rxbuf_base = (void*)(card->hw.dpmbase +
			(info->rxb_ptr - PPP508_MB_VECT));

		card->u.p.rxbuf_last = (ppp_buf_ctl_t*)card->u.p.rxbuf_base +
			(info->rxb_num - 1);

		card->u.p.rx_base = info->rxb_base;
		card->u.p.rx_top  = info->rxb_end;
	}

	card->u.p.txbuf = card->u.p.txbuf_base;
	card->rxmb = card->u.p.rxbuf_base;

}

/*=============================================================================
 * Perform the Interrupt Test by running the READ_CODE_VERSION command MAX_INTR
 * _TEST_COUNTER times.
 */
static int intr_test( sdla_t* card )
{
	ppp_mbox_t* mb = card->mbox;
	int err,i;

	/* The critical flag is unset because during intialization (if_open) 
	 * we want the interrupts to be enabled so that when the wpp_isr is
	 * called it does not exit due to critical flag set.
	 */ 
	 
	card->wandev.critical = 0;

	err = ppp_set_intr_mode( card, 0x08 );
	
	if ( err == CMD_OK ) 
	{ 	
		for (i=0; i<MAX_INTR_TEST_COUNTER; i++) 
		{	
			/* Run command READ_CODE_VERSION */
			memset(&mb->cmd, 0, sizeof(ppp_cmd_t));
			mb->cmd.length  = 0;
			mb->cmd.command = 0x10;
			err = sdla_exec(mb) ? mb->cmd.result : CMD_TIMEOUT;
			
			if (err != CMD_OK) 
				ppp_error(card, err, mb);
		}
	}
	else return err;

	err = ppp_set_intr_mode( card, 0 );
	if (err != CMD_OK) 
		return err;

	card->wandev.critical = 1;
	return 0;
}

/****** End *****************************************************************/