text: /*****************************************************************************
  * sdla_chdlc.c	WANPIPE(tm) Multiprotocol WAN Link Driver. Cisco HDLC module.
  *
  * Authors: 	Nenad Corbic <ncorbic@sangoma.com>
  *		Gideon Hack  
  *
  * Copyright:	(c) 1995-2001 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.
  * ============================================================================
  * Feb 28, 2001  Nenad Corbic	Updated if_tx_timeout() routine for 
  * 				2.4.X kernels.
  * Jan 25, 2001  Nenad Corbic	Added a TTY Sync serial driver over the
  * 				HDLC streaming protocol
  * 				Added a TTY Async serial driver over the
  * 				Async protocol.
  * Dec 15, 2000  Nenad Corbic    Updated for 2.4.X Kernel support
  * Nov 13, 2000  Nenad Corbic    Added true interface type encoding option.
  * 				Tcpdump doesn't support CHDLC inteface
  * 				types, to fix this "true type" option will set
  * 				the interface type to RAW IP mode.
  * Nov 07, 2000  Nenad Corbic	Added security features for UDP debugging:
  *                               Deny all and specify allowed requests.
  * Jun 20, 2000  Nenad Corbic	Fixed the API IP ERROR bug. Caused by the 
  *                               latest update.
  * May 09, 2000	Nenad Corbic	Option to bring down an interface
  *                               upon disconnect.
  * Mar 23, 2000  Nenad Corbic	Improved task queue, bh handling.
  * Mar 16, 2000	Nenad Corbic	Fixed the SLARP Dynamic IP addressing.
  * Mar 06, 2000  Nenad Corbic	Bug Fix: corrupted mbox recovery.
  * Feb 10, 2000  Gideon Hack     Added ASYNC support.
  * Feb 09, 2000  Nenad Corbic    Fixed two shutdown bugs in update() and
  *                               if_stats() functions.
  * Jan 24, 2000  Nenad Corbic    Fixed a startup wanpipe state racing,  
  *                               condition between if_open and isr. 
  * Jan 10, 2000  Nenad Corbic    Added new socket API support.
  * Dev 15, 1999  Nenad Corbic    Fixed up header files for 2.0.X kernels
  * Nov 20, 1999  Nenad Corbic 	Fixed zero length API bug.
  * Sep 30, 1999  Nenad Corbic    Fixed dynamic IP and route setup.
  * Sep 23, 1999  Nenad Corbic    Added SMP support, fixed tracing 
  * Sep 13, 1999  Nenad Corbic	Split up Port 0 and 1 into separate devices.
  * Jun 02, 1999  Gideon Hack     Added support for the S514 adapter.
  * Oct 30, 1998	Jaspreet Singh	Added Support for CHDLC API (HDLC STREAMING).
  * Oct 28, 1998	Jaspreet Singh	Added Support for Dual Port CHDLC.
  * Aug 07, 1998	David Fong	Initial version.
  *****************************************************************************/
  
  #include <linux/module.h>
  #include <linux/version.h>
  #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/slab.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 */
  
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
   #include <asm/uaccess.h>
   #include <linux/inetdevice.h>
   #include <linux/netdevice.h>
  #else 				
   #include <asm/segment.h>
   #include <net/route.h>          /* Adding new route entries : 2.0.X kernels */
  #endif
  
  #include <linux/in.h>		/* sockaddr_in */
  #include <linux/inet.h>	
  #include <linux/if.h>
  #include <asm/byteorder.h>	/* htons(), etc. */
  #include <linux/sdlapci.h>
  #include <asm/io.h>
  
  #include <linux/sdla_chdlc.h>		/* CHDLC firmware API definitions */
  #include <linux/sdla_asy.h>           	/* CHDLC (async) API definitions */
  
  #include <linux/if_wanpipe_common.h>    /* Socket Driver common area */
  #include <linux/if_wanpipe.h>		
  
  /* TTY Includes */
  #include <linux/tty.h>
  #include <linux/tty_flip.h>
  #include <linux/serial.h>
  
  
  /****** Defines & Macros ****************************************************/
  
  /* reasons for enabling the timer interrupt on the adapter */
  #define TMR_INT_ENABLED_UDP   		0x01
  #define TMR_INT_ENABLED_UPDATE		0x02
  #define TMR_INT_ENABLED_CONFIG		0x10
  
  #define MAX_IP_ERRORS	10
  
  #define TTY_CHDLC_MAX_MTU	2000
  #define	CHDLC_DFLT_DATA_LEN	1500		/* default MTU */
  #define CHDLC_HDR_LEN		1
  
  #define CHDLC_API 0x01
  
  #define PORT(x)   (x == 0 ? "PRIMARY" : "SECONDARY" )
  #define MAX_BH_BUFF	10
  
  //#define PRINT_DEBUG
  #ifdef PRINT_DEBUG
  #define dbg_printk(format, a...) printk(format, ## a)
  #else
  #define dbg_printk(format, a...)
  #endif  
  
  /******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 CHDLC specific data
   */
  
  typedef struct chdlc_private_area
  {
  	wanpipe_common_t common;
  	sdla_t		*card;
  	int 		TracingEnabled;		/* For enabling Tracing */
  	unsigned long 	curr_trace_addr;	/* Used for Tracing */
  	unsigned long 	start_trace_addr;
  	unsigned long 	end_trace_addr;
  	unsigned long 	base_addr_trace_buffer;
  	unsigned long 	end_addr_trace_buffer;
  	unsigned short 	number_trace_elements;
  	unsigned  	available_buffer_space;
  	unsigned long 	router_start_time;
  	unsigned char 	route_status;
  	unsigned char 	route_removed;
  	unsigned long 	tick_counter;		/* For 5s timeout counter */
  	unsigned long 	router_up_time;
          u32             IP_address;		/* IP addressing */
          u32             IP_netmask;
  	u32		ip_local;
  	u32		ip_remote;
  	u32 		ip_local_tmp;
  	u32		ip_remote_tmp;
  	u8		ip_error;
  	u8		config_chdlc;
  	u8 		config_chdlc_timeout;
  	unsigned char  mc;			/* Mulitcast support on/off */
  	unsigned short udp_pkt_lgth;		/* udp packet processing */
  	char udp_pkt_src;
  	char udp_pkt_data[MAX_LGTH_UDP_MGNT_PKT];
  	unsigned short timer_int_enabled;
  	char update_comms_stats;		/* updating comms stats */
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	bh_data_t *bh_head;	  	  /* Circular buffer for chdlc_bh */
  	unsigned long  tq_working;
  	volatile int  bh_write;
  	volatile int  bh_read;
  	atomic_t  bh_buff_used;
  #endif
  	
  	unsigned char interface_down;
  
  	/* Polling task queue. Each interface
           * has its own task queue, which is used
           * to defer events from the interrupt */
  	struct tq_struct poll_task;
  	struct timer_list poll_delay_timer;
  
  	u8 gateway;
  	u8 true_if_encoding;
  	//FIXME: add driver stats as per frame relay!
  
  } chdlc_private_area_t;
  
  /* Route Status options */
  #define NO_ROUTE	0x00
  #define ADD_ROUTE	0x01
  #define ROUTE_ADDED	0x02
  #define REMOVE_ROUTE	0x03
  
  
  /* variable for keeping track of enabling/disabling FT1 monitor status */
  static int rCount = 0;
  
  /* variable for tracking how many interfaces to open for WANPIPE on the
     two ports */
  
  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, netdevice_t* dev,
  	wanif_conf_t* conf);
  
  /* Network device interface */
  static int if_init   (netdevice_t* dev);
  static int if_open   (netdevice_t* dev);
  static int if_close  (netdevice_t* dev);
  static int if_header (struct sk_buff* skb, netdevice_t* dev,
  	unsigned short type, void* daddr, void* saddr, unsigned len);
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
    static int if_rebuild_hdr (struct sk_buff *skb);
    static struct net_device_stats* if_stats (netdevice_t* dev);
  
  #else
    static int if_rebuild_hdr (void* hdr, netdevice_t* dev, unsigned long raddr,
          struct sk_buff* skb);
    static struct enet_statistics* if_stats (netdevice_t* dev);
  #endif
    
  static int if_send (struct sk_buff* skb, netdevice_t* dev);
  
  /* CHDLC Firmware interface functions */
  static int chdlc_configure 	(sdla_t* card, void* data);
  static int chdlc_comm_enable 	(sdla_t* card);
  static int chdlc_read_version 	(sdla_t* card, char* str);
  static int chdlc_set_intr_mode 	(sdla_t* card, unsigned mode);
  static int chdlc_send (sdla_t* card, void* data, unsigned len);
  static int chdlc_read_comm_err_stats (sdla_t* card);
  static int chdlc_read_op_stats (sdla_t* card);
  static int chdlc_error (sdla_t *card, int err, CHDLC_MAILBOX_STRUCT *mb);
  
  
  static int chdlc_disable_comm_shutdown (sdla_t *card);
  #ifdef LINUX_2_4
    static void if_tx_timeout (netdevice_t *dev);
  #endif
  
  /* Miscellaneous CHDLC Functions */
  static int set_chdlc_config (sdla_t* card);
  static void init_chdlc_tx_rx_buff( sdla_t* card);
  static int process_chdlc_exception(sdla_t *card);
  static int process_global_exception(sdla_t *card);
  static int update_comms_stats(sdla_t* card,
          chdlc_private_area_t* chdlc_priv_area);
  static int configure_ip (sdla_t* card);
  static int unconfigure_ip (sdla_t* card);
  static void process_route(sdla_t *card);
  static void port_set_state (sdla_t *card, int);
  static int config_chdlc (sdla_t *card);
  static void disable_comm (sdla_t *card);
  
  static void trigger_chdlc_poll (netdevice_t *);
  static void chdlc_poll (netdevice_t *);
  static void chdlc_poll_delay (unsigned long dev_ptr);
  
  
  /* Miscellaneous asynchronous interface Functions */
  static int set_asy_config (sdla_t* card);
  static int asy_comm_enable (sdla_t* card);
  
  /* Interrupt handlers */
  static void wpc_isr (sdla_t* card);
  static void rx_intr (sdla_t* card);
  static void timer_intr(sdla_t *);
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
    /* Bottom half handlers */
    static void chdlc_bh (netdevice_t *);
    static int chdlc_bh_cleanup (netdevice_t *);
    static int bh_enqueue (netdevice_t *, struct sk_buff *);
  #endif
  
  /* Miscellaneous functions */
  static int chk_bcast_mcast_addr(sdla_t* card, netdevice_t* dev,
  				struct sk_buff *skb);
  static int reply_udp( unsigned char *data, unsigned int mbox_len );
  static int intr_test( sdla_t* card);
  static int udp_pkt_type( struct sk_buff *skb , sdla_t* card);
  static int store_udp_mgmt_pkt(char udp_pkt_src, sdla_t* card,
                                  struct sk_buff *skb, netdevice_t* dev,
                                  chdlc_private_area_t* chdlc_priv_area);
  static int process_udp_mgmt_pkt(sdla_t* card, netdevice_t* dev,  
  				chdlc_private_area_t* chdlc_priv_area);
  static unsigned short calc_checksum (char *, int);
  static void s508_lock (sdla_t *card, unsigned long *smp_flags);
  static void s508_unlock (sdla_t *card, unsigned long *smp_flags);
  
  
  static int  Intr_test_counter;
  
  /* TTY Global Definitions */
  
  #if defined(LINUX_2_4) || defined(LINUX_2_1)
  
  #define NR_PORTS 4
  #define WAN_TTY_MAJOR 226
  #define WAN_TTY_MINOR 0
  
  #define WAN_CARD(port) (tty_card_map[port])
  #define MIN_PORT 0
  #define MAX_PORT NR_PORTS-1 
  
  #define CRC_LENGTH 2
  
  static int wanpipe_tty_init(sdla_t *card);
  static void wanpipe_tty_receive(sdla_t *, unsigned, unsigned int);
  static void wanpipe_tty_trigger_poll(sdla_t *card);
  
  static struct tty_driver serial_driver, callout_driver;
  static int serial_refcount=1;
  static int tty_init_cnt=0;
  
  static struct serial_state rs_table[NR_PORTS];
  static struct tty_struct *serial_table[NR_PORTS];
  static struct termios *serial_termios[NR_PORTS];
  static struct termios *serial_termios_locked[NR_PORTS];
  
  static char tty_driver_mode=WANOPT_TTY_SYNC;
  
  static char *opt_decode[] = {"NONE","CRTSCTS","XONXOFF-RX",
  	  	             "CRTSCTS XONXOFF-RX","XONXOFF-TX",
  		             "CRTSCTS XONXOFF-TX","CRTSCTS XONXOFF"};
  static char *p_decode[] = {"NONE","ODD","EVEN"};
  
  static void* tty_card_map[NR_PORTS] = {NULL,NULL,NULL,NULL};
  
  #endif
  
  
  /****** Public Functions ****************************************************/
  
  /*============================================================================
   * Cisco HDLC 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 wpc_init (sdla_t* card, wandev_conf_t* conf)
  {
  	unsigned char port_num;
  	int err;
  	unsigned long max_permitted_baud = 0;
  	SHARED_MEMORY_INFO_STRUCT *flags;
  
  	union
  		{
  		char str[80];
  		} u;
  	volatile CHDLC_MAILBOX_STRUCT* mb;
  	CHDLC_MAILBOX_STRUCT* mb1;
  	unsigned long timeout;
  
  	/* Verify configuration ID */
  	if (conf->config_id != WANCONFIG_CHDLC) {
  		printk(KERN_INFO "%s: invalid configuration ID %u!\n",
  				  card->devname, conf->config_id);
  		return -EINVAL;
  	}
  
  	/* Find out which Port to use */
  	if ((conf->comm_port == WANOPT_PRI) || (conf->comm_port == WANOPT_SEC)){
  		if (card->next){
  
  			if (conf->comm_port != card->next->u.c.comm_port){
  				card->u.c.comm_port = conf->comm_port;
  			}else{
  				printk(KERN_INFO "%s: ERROR - %s port used!\n",
          		        	card->wandev.name, PORT(conf->comm_port));
  				return -EINVAL;
  			}
  		}else{
  			card->u.c.comm_port = conf->comm_port;
  		}
  	}else{
  		printk(KERN_INFO "%s: ERROR - Invalid Port Selected!\n",
                  			card->wandev.name);
  		return -EINVAL;
  	}
  	
  
  	/* Initialize protocol-specific fields */
  	if(card->hw.type != SDLA_S514){
  
  		if (card->u.c.comm_port == WANOPT_PRI){	
  			card->mbox  = (void *) card->hw.dpmbase;
  		}else{
  			card->mbox  = (void *) card->hw.dpmbase + 
  				SEC_BASE_ADDR_MB_STRUCT - PRI_BASE_ADDR_MB_STRUCT;
  		}	
  	}else{ 
  		/* for a S514 adapter, set a pointer to the actual mailbox in the */
  		/* allocated virtual memory area */
  		if (card->u.c.comm_port == WANOPT_PRI){
  			card->mbox = (void *) card->hw.dpmbase + PRI_BASE_ADDR_MB_STRUCT;
  		}else{
  			card->mbox = (void *) card->hw.dpmbase + SEC_BASE_ADDR_MB_STRUCT;
  		}	
  	}
  
  	mb = mb1 = card->mbox;
  
  	if (!card->configured){
  
  		/* The board will place an 'I' in the return code to indicate that it is
  	   	ready to accept commands.  We expect this to be completed in less
             	than 1 second. */
  
  		timeout = jiffies;
  		while (mb->return_code != 'I')	/* Wait 1s for board to initialize */
  			if ((jiffies - timeout) > 1*HZ) break;
  
  		if (mb->return_code != 'I') {
  			printk(KERN_INFO
  				"%s: Initialization not completed by adapter\n",
  				card->devname);
  			printk(KERN_INFO "Please contact Sangoma representative.\n");
  			return -EIO;
  		}
  	}
  
  	/* 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 (chdlc_read_version(card, u.str))
  		return -EIO;
  
  	printk(KERN_INFO "%s: Running Cisco HDLC firmware v%s\n",
  		card->devname, u.str); 
  
  	card->isr			= &wpc_isr;
  	card->poll			= NULL;
  	card->exec			= NULL;
  	card->wandev.update		= &update;
   	card->wandev.new_if		= &new_if;
  	card->wandev.del_if		= NULL;
  	card->wandev.udp_port   	= conf->udp_port;
  	card->disable_comm		= &disable_comm;
  	card->wandev.new_if_cnt = 0;
  
  	/* reset the number of times the 'update()' proc has been called */
  	card->u.c.update_call_count = 0;
  	
  	card->wandev.ttl = conf->ttl;
  	card->wandev.interface = conf->interface; 
  
  	if ((card->u.c.comm_port == WANOPT_SEC && conf->interface == WANOPT_V35)&&
  	    card->hw.type != SDLA_S514){
  		printk(KERN_INFO "%s: ERROR - V35 Interface not supported on S508 %s port \n",
  			card->devname, PORT(card->u.c.comm_port));
  		return -EIO;
  	}
  
  	card->wandev.clocking = conf->clocking;
  
  	port_num = card->u.c.comm_port;
  
  	/* in API mode, we can configure for "receive only" buffering */
  	if(card->hw.type == SDLA_S514) {
  		card->u.c.receive_only = conf->receive_only;
  		if(conf->receive_only) {
  			printk(KERN_INFO
  				"%s: Configured for 'receive only' mode\n",
                                  card->devname);
  		}
  	}
  
  	/* Setup Port Bps */
  
  	if(card->wandev.clocking) {
  		if((port_num == WANOPT_PRI) || card->u.c.receive_only) {
  			/* For Primary Port 0 */
                 		max_permitted_baud =
  				(card->hw.type == SDLA_S514) ?
  				PRI_MAX_BAUD_RATE_S514 : 
  				PRI_MAX_BAUD_RATE_S508;
  
  		}else if(port_num == WANOPT_SEC) {
  			/* For Secondary Port 1 */
                          max_permitted_baud =
                                 (card->hw.type == SDLA_S514) ?
                                  SEC_MAX_BAUD_RATE_S514 :
                                  SEC_MAX_BAUD_RATE_S508;
                          }
    
  			if(conf->bps > max_permitted_baud) {
  				conf->bps = max_permitted_baud;
  				printk(KERN_INFO "%s: Baud too high!\n",
  					card->wandev.name);
   				printk(KERN_INFO "%s: Baud rate set to %lu bps\n", 
  					card->wandev.name, max_permitted_baud);
  			}
  			card->wandev.bps = conf->bps;
  	}else{
          	card->wandev.bps = 0;
    	}
  
  	/* Setup the Port MTU */
  	if((port_num == WANOPT_PRI) || card->u.c.receive_only) {
  
  		/* For Primary Port 0 */
  		card->wandev.mtu =
  			(conf->mtu >= MIN_LGTH_CHDLC_DATA_CFG) ?
  			min_t(unsigned int, conf->mtu, PRI_MAX_NO_DATA_BYTES_IN_FRAME) :
  			CHDLC_DFLT_DATA_LEN;
  	} else if(port_num == WANOPT_SEC) { 
  		/* For Secondary Port 1 */
  		card->wandev.mtu =
  			(conf->mtu >= MIN_LGTH_CHDLC_DATA_CFG) ?
  			min_t(unsigned int, conf->mtu, SEC_MAX_NO_DATA_BYTES_IN_FRAME) :
  			CHDLC_DFLT_DATA_LEN;
  	}
  
  	/* Set up the interrupt status area */
  	/* Read the CHDLC Configuration and obtain: 
  	 *	Ptr to shared memory infor struct
           * Use this pointer to calculate the value of card->u.c.flags !
   	 */
  	mb1->buffer_length = 0;
  	mb1->command = READ_CHDLC_CONFIGURATION;
  	err = sdla_exec(mb1) ? mb1->return_code : CMD_TIMEOUT;
  	if(err != COMMAND_OK) {
                  if(card->hw.type != SDLA_S514)
                  	enable_irq(card->hw.irq);
  
  		chdlc_error(card, err, mb1);
  		return -EIO;
  	}
  
  	if(card->hw.type == SDLA_S514){
                 	card->u.c.flags = (void *)(card->hw.dpmbase +
                 		(((CHDLC_CONFIGURATION_STRUCT *)mb1->data)->
  			ptr_shared_mem_info_struct));
          }else{
                  card->u.c.flags = (void *)(card->hw.dpmbase +
                          (((CHDLC_CONFIGURATION_STRUCT *)mb1->data)->
  			ptr_shared_mem_info_struct % SDLA_WINDOWSIZE));
  	}
  
  	flags = card->u.c.flags;
  	
  	/* This is for the ports link state */
  	card->wandev.state = WAN_DUALPORT;
  	card->u.c.state = WAN_DISCONNECTED;
  
  
  	if (!card->wandev.piggyback){	
  		int err;
  
  		/* Perform interrupt testing */
  		err = intr_test(card);
  
  		if(err || (Intr_test_counter < MAX_INTR_TEST_COUNTER)) { 
  			printk(KERN_INFO "%s: Interrupt test failed (%i)\n",
  					card->devname, Intr_test_counter);
  			printk(KERN_INFO "%s: Please choose another interrupt\n",
  					card->devname);
  			return -EIO;
  		}
  		
  		printk(KERN_INFO "%s: Interrupt test passed (%i)\n", 
  				card->devname, Intr_test_counter);
  		card->configured = 1;
  	}
  
  	if ((card->tty_opt=conf->tty) == WANOPT_YES){
  #if defined(LINUX_2_4) || defined(LINUX_2_1)	
  		int err;
  		card->tty_minor = conf->tty_minor;
  
  		/* On ASYNC connections internal clocking 
  		 * is mandatory */
  		if ((card->u.c.async_mode = conf->tty_mode)){
  			card->wandev.clocking = 1;
  		}
  		err=wanpipe_tty_init(card);
  		if (err){
  			return err;
  		}
  #else
  		printk(KERN_INFO "%s: Error: TTY driver is not supported on 2.0.X kernels!\n",
  				card->devname);	
  		return -EINVAL;  
  #endif
  	}else{
  	
  
  		if (chdlc_set_intr_mode(card, APP_INT_ON_TIMER)){
  			printk (KERN_INFO "%s: 
  				Failed to set interrupt triggers!\n",
  				card->devname);
  			return -EIO;	
          	}
  	
  		/* Mask the Timer interrupt */
  		flags->interrupt_info_struct.interrupt_permission &= 
  			~APP_INT_ON_TIMER;
  	}
  
  	/* If we are using CHDLC in backup mode, this flag will
  	 * indicate not to look for IP addresses in config_chdlc()*/
  	card->u.c.backup = conf->backup;
  	
  	printk(KERN_INFO "\n");
  
  	return 0;
  }
  
  /******* WAN Device Driver Entry Points *************************************/
  
  /*============================================================================
   * Update device status & statistics
   * This procedure is called when updating the PROC file system and returns
   * various communications statistics. These statistics are accumulated from 3 
   * different locations:
   * 	1) The 'if_stats' recorded for the device.
   * 	2) Communication error statistics on the adapter.
   *      3) CHDLC operational statistics on the adapter.
   * The board level statistics are read during a timer interrupt. Note that we 
   * read the error and operational statistics during consecitive timer ticks so
   * as to minimize the time that we are inside the interrupt handler.
   *
   */
  static int update (wan_device_t* wandev)
  {
  	sdla_t* card = wandev->private;
   	netdevice_t* dev;
          volatile chdlc_private_area_t* chdlc_priv_area;
          SHARED_MEMORY_INFO_STRUCT *flags;
  	unsigned long timeout;
  
  	/* sanity checks */
  	if((wandev == NULL) || (wandev->private == NULL))
  		return -EFAULT;
  	
  	if(wandev->state == WAN_UNCONFIGURED)
  		return -ENODEV;
  
  	/* more sanity checks */
          if(!card->u.c.flags)
                  return -ENODEV;
  
  	if(test_bit(PERI_CRIT, (void*)&card->wandev.critical))
                  return -EAGAIN;
  
  	if((dev=card->wandev.dev) == NULL)
  		return -ENODEV;
  
  	if((chdlc_priv_area=dev->priv) == NULL)
  		return -ENODEV;
  
        	flags = card->u.c.flags;
         	if(chdlc_priv_area->update_comms_stats){
  		return -EAGAIN;
  	}
  			
  	/* we will need 2 timer interrupts to complete the */
  	/* reading of the statistics */
  	chdlc_priv_area->update_comms_stats = 2;
         	flags->interrupt_info_struct.interrupt_permission |= APP_INT_ON_TIMER;
  	chdlc_priv_area->timer_int_enabled = TMR_INT_ENABLED_UPDATE;
    
  	/* wait a maximum of 1 second for the statistics to be updated */ 
          timeout = jiffies;
          for(;;) {
  		if(chdlc_priv_area->update_comms_stats == 0)
  			break;
                  if ((jiffies - timeout) > (1 * HZ)){
      			chdlc_priv_area->update_comms_stats = 0;
   			chdlc_priv_area->timer_int_enabled &=
  				~TMR_INT_ENABLED_UPDATE; 
   			return -EAGAIN;
  		}
          }
  
  	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, netdevice_t* dev, wanif_conf_t* conf)
  {
  	sdla_t* card = wandev->private;
  	chdlc_private_area_t* chdlc_priv_area;
  
  
  	printk(KERN_INFO "%s: Configuring Interface: %s\n",
  			card->devname, conf->name);
   
  	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 */
  	chdlc_priv_area = kmalloc(sizeof(chdlc_private_area_t), GFP_KERNEL);
  	
  	if(chdlc_priv_area == NULL) 
  		return -ENOMEM;
  
  	memset(chdlc_priv_area, 0, sizeof(chdlc_private_area_t));
  
  	chdlc_priv_area->card = card; 
  	chdlc_priv_area->common.sk = NULL;
  	chdlc_priv_area->common.func = NULL;	
  
  	/* initialize data */
  	strcpy(card->u.c.if_name, conf->name);
  
  	if(card->wandev.new_if_cnt > 0) {
                  kfree(chdlc_priv_area);
  		return -EEXIST;
  	}
  
  	card->wandev.new_if_cnt++;
  
  	chdlc_priv_area->TracingEnabled = 0;
  	chdlc_priv_area->route_status = NO_ROUTE;
  	chdlc_priv_area->route_removed = 0;
  
  	card->u.c.async_mode = conf->async_mode;
  	
  	/* setup for asynchronous mode */
  	if(conf->async_mode) {
  		printk(KERN_INFO "%s: Configuring for asynchronous mode\n",
  			wandev->name);
  
  		if(card->u.c.comm_port == WANOPT_PRI) {
  			printk(KERN_INFO
  				"%s:Asynchronous mode on secondary port only\n",
  					wandev->name);
  			kfree(chdlc_priv_area);
  			return -EINVAL;
  		}
  
  	       	if(strcmp(conf->usedby, "WANPIPE") == 0) {
  			printk(KERN_INFO
                                  "%s: Running in WANIPE Async Mode\n",                                        			wandev->name);
  			card->u.c.usedby = WANPIPE;
  		}else{
  			card->u.c.usedby = API;
  		}
  
  		if(!card->wandev.clocking) {
  			printk(KERN_INFO
  				"%s: Asynch. clocking must be 'Internal'\n",
  				wandev->name);
  			kfree(chdlc_priv_area);
  			return -EINVAL;
  		}
  
  		if((card->wandev.bps < MIN_ASY_BAUD_RATE) ||
  			(card->wandev.bps > MAX_ASY_BAUD_RATE)) {
  			printk(KERN_INFO "%s: Selected baud rate is invalid.\n",
  				wandev->name);
  			printk(KERN_INFO "Must be between %u and %u bps.\n",
  				MIN_ASY_BAUD_RATE, MAX_ASY_BAUD_RATE);
  			kfree(chdlc_priv_area);
  			return -EINVAL;
  		}
  
  		card->u.c.api_options = 0;
                  if (conf->asy_data_trans == WANOPT_YES) {
                          card->u.c.api_options |= ASY_RX_DATA_TRANSPARENT;
                  }
  		
  		card->u.c.protocol_options = 0;
  		if (conf->rts_hs_for_receive == WANOPT_YES) {
  			card->u.c.protocol_options |= ASY_RTS_HS_FOR_RX;
  	        }
                  if (conf->xon_xoff_hs_for_receive == WANOPT_YES) {
                          card->u.c.protocol_options |= ASY_XON_XOFF_HS_FOR_RX;
                  }
                  if (conf->xon_xoff_hs_for_transmit == WANOPT_YES) {
                          card->u.c.protocol_options |= ASY_XON_XOFF_HS_FOR_TX;
                  }
                  if (conf->dcd_hs_for_transmit == WANOPT_YES) {
                          card->u.c.protocol_options |= ASY_DCD_HS_FOR_TX;
                  }
                  if (conf->cts_hs_for_transmit == WANOPT_YES) {
                          card->u.c.protocol_options |= ASY_CTS_HS_FOR_TX;
                  }
  
  		card->u.c.tx_bits_per_char = conf->tx_bits_per_char;
                  card->u.c.rx_bits_per_char = conf->rx_bits_per_char;
                  card->u.c.stop_bits = conf->stop_bits;
  		card->u.c.parity = conf->parity;
  		card->u.c.break_timer = conf->break_timer;
  		card->u.c.inter_char_timer = conf->inter_char_timer;
  		card->u.c.rx_complete_length = conf->rx_complete_length;
  		card->u.c.xon_char = conf->xon_char;
  
  	} else {	/* setup for synchronous mode */
  
  		card->u.c.protocol_options = 0;
  		if (conf->ignore_dcd == WANOPT_YES){
  			card->u.c.protocol_options |= IGNORE_DCD_FOR_LINK_STAT;
  		}
  		if (conf->ignore_cts == WANOPT_YES){
  			card->u.c.protocol_options |= IGNORE_CTS_FOR_LINK_STAT;
  		}
  
  		if (conf->ignore_keepalive == WANOPT_YES) {
  			card->u.c.protocol_options |=
  				IGNORE_KPALV_FOR_LINK_STAT;
  			card->u.c.kpalv_tx  = MIN_Tx_KPALV_TIMER; 
  			card->u.c.kpalv_rx  = MIN_Rx_KPALV_TIMER; 
  			card->u.c.kpalv_err = MIN_KPALV_ERR_TOL; 
  
  		} else {   /* Do not ignore keepalives */
  			card->u.c.kpalv_tx =
  				((conf->keepalive_tx_tmr - MIN_Tx_KPALV_TIMER)
  				>= 0) ?
  	   			min_t(unsigned int, conf->keepalive_tx_tmr,MAX_Tx_KPALV_TIMER) :
  				DEFAULT_Tx_KPALV_TIMER;
  
  			card->u.c.kpalv_rx =
  		   		((conf->keepalive_rx_tmr - MIN_Rx_KPALV_TIMER)
  				>= 0) ?
  	   			min_t(unsigned int, conf->keepalive_rx_tmr,MAX_Rx_KPALV_TIMER) :
  				DEFAULT_Rx_KPALV_TIMER;
  
  			card->u.c.kpalv_err =
  		   		((conf->keepalive_err_margin-MIN_KPALV_ERR_TOL)
  				>= 0) ?
  	   			min_t(unsigned int, conf->keepalive_err_margin,
  				MAX_KPALV_ERR_TOL) : 
  	   			DEFAULT_KPALV_ERR_TOL;
  		}
  
  		/* Setup slarp timer to control delay between slarps */
  		card->u.c.slarp_timer = 
  			((conf->slarp_timer - MIN_SLARP_REQ_TIMER) >= 0) ?
  			min_t(unsigned int, conf->slarp_timer, MAX_SLARP_REQ_TIMER) :
  			DEFAULT_SLARP_REQ_TIMER;
  
  #ifdef LINUX_2_0
  		if (card->u.c.slarp_timer){
  			printk(KERN_INFO 
  				"%s: Error: Dynamic IP support not available for 2.0.X kernels\n",
  					card->devname);
  			printk(KERN_INFO "%s:        Defaulting to Static IP addressing\n",
  						card->devname);
  		}
  		card->u.c.slarp_timer=0;
  #endif	
  
  
  		if (conf->hdlc_streaming == WANOPT_YES) {
  			printk(KERN_INFO "%s: Enabling HDLC STREAMING Mode\n",
  				wandev->name);
  			card->u.c.protocol_options = HDLC_STREAMING_MODE;
  		}
  
  		if ((chdlc_priv_area->true_if_encoding = conf->true_if_encoding) == WANOPT_YES){
  			printk(KERN_INFO 
  				"%s: Enabling, true interface type encoding.\n",
  				card->devname);
  		}
  		
          	/* Setup wanpipe as a router (WANPIPE) or as an API */
  		if( strcmp(conf->usedby, "WANPIPE") == 0) {
  
  			printk(KERN_INFO "%s: Running in WANPIPE mode!\n",
  				wandev->name);
  			card->u.c.usedby = WANPIPE;
  
  			/* Option to bring down the interface when 
          		 * the link goes down */
  			if (conf->if_down){
  				set_bit(DYN_OPT_ON,&chdlc_priv_area->interface_down);
  				printk(KERN_INFO 
  				 "%s: Dynamic interface configuration enabled\n",
  				   card->devname);
  			} 
  
  		} else if( strcmp(conf->usedby, "API") == 0) {
  #if defined(LINUX_2_1) || defined(LINUX_2_4) 
  			card->u.c.usedby = API;
  			printk(KERN_INFO "%s: Running in API mode !\n",
  				wandev->name);
  #else
  			printk(KERN_INFO "%s: API Mode is not supported for kernels lower than 2.2.X!\n",
  				wandev->name);
  			printk(KERN_INFO "%s: Please upgrade to a 2.2.X kernel fro the API support\n",
  				wandev->name);
  	                kfree(chdlc_priv_area);
  			return -EINVAL;
  #endif
  		}
  	}
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	/* Tells us that if this interface is a
           * gateway or not */
  	if ((chdlc_priv_area->gateway = conf->gateway) == WANOPT_YES){
  		printk(KERN_INFO "%s: Interface %s is set as a gateway.\n",
  			card->devname,card->u.c.if_name);
  	}
  #endif
  
  	/* Get Multicast Information */
  	chdlc_priv_area->mc = conf->mc;
  
  	/* prepare network device data space for registration */
  #ifdef LINUX_2_4
  	strcpy(dev->name,card->u.c.if_name);
  #else
  	dev->name = (char *)kmalloc(strlen(card->u.c.if_name) + 2, GFP_KERNEL); 
  	sprintf(dev->name, "%s", card->u.c.if_name);
  #endif
  
  	dev->init = &if_init;
  	dev->priv = chdlc_priv_area;
  
  	/* Initialize the polling task routine */
  #ifndef LINUX_2_4
  	chdlc_priv_area->poll_task.next = NULL;
  #endif
  	chdlc_priv_area->poll_task.sync=0;
  	chdlc_priv_area->poll_task.routine = (void*)(void*)chdlc_poll;
  	chdlc_priv_area->poll_task.data = dev;
  
  	/* Initialize the polling delay timer */
  	init_timer(&chdlc_priv_area->poll_delay_timer);
  	chdlc_priv_area->poll_delay_timer.data = (unsigned long)dev;
  	chdlc_priv_area->poll_delay_timer.function = chdlc_poll_delay;
  	
  	printk(KERN_INFO "\n");
  
  	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 (netdevice_t* dev)
  	{
  	chdlc_private_area_t* chdlc_priv_area = dev->priv;
  	sdla_t* card = chdlc_priv_area->card;
  	wan_device_t* wandev = &card->wandev;
  #ifdef LINUX_2_0
  	int i;
  #endif
  
  	/* 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;
  #ifdef LINUX_2_4
  	dev->tx_timeout		= &if_tx_timeout;
  	dev->watchdog_timeo	= TX_TIMEOUT;
  #endif
  
  	
  	/* Initialize media-specific parameters */
  	dev->flags		|= IFF_POINTOPOINT;
  	dev->flags		|= IFF_NOARP;
  
  	/* Enable Mulitcasting if user selected */
  	if (chdlc_priv_area->mc == WANOPT_YES){
  		dev->flags 	|= IFF_MULTICAST;
  	}
  	
  #ifdef LINUX_2_0
  	dev->family		= AF_INET;
  #endif	
  
  	if (chdlc_priv_area->true_if_encoding){
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  		dev->type	= ARPHRD_HDLC; /* This breaks the tcpdump */
  #else
  		dev->type	= ARPHRD_PPP;
  #endif
  	}else{
  		dev->type	= ARPHRD_PPP;
  	}
  	
  	dev->mtu		= card->wandev.mtu;
  	/* for API usage, add the API header size to the requested MTU size */
  	if(card->u.c.usedby == API) {
  		dev->mtu += sizeof(api_tx_hdr_t);
  	}
   
  	dev->hard_header_len	= CHDLC_HDR_LEN;
  
  	/* Initialize hardware parameters */
  	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 
  	 * If too low packets will not be retransmitted 
           * by stack.
  	 */
          dev->tx_queue_len = 100;
     
  	/* Initialize socket buffers */
  #if !defined(LINUX_2_1) && !defined(LINUX_2_4)
          for (i = 0; i < DEV_NUMBUFFS; ++i)
                  skb_queue_head_init(&dev->buffs[i]);
  #endif
  	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 (netdevice_t* dev)
  {
  	chdlc_private_area_t* chdlc_priv_area = dev->priv;
  	sdla_t* card = chdlc_priv_area->card;
  	struct timeval tv;
  	int err = 0;
  
  	/* Only one open per interface is allowed */
  
  	if (is_dev_running(dev))
  		return -EBUSY;
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	/* Initialize the task queue */
  	chdlc_priv_area->tq_working=0;
  
  #ifndef LINUX_2_4
  	chdlc_priv_area->common.wanpipe_task.next = NULL;
  #endif
  	chdlc_priv_area->common.wanpipe_task.sync = 0;
  	chdlc_priv_area->common.wanpipe_task.routine = (void *)(void *)chdlc_bh;
  	chdlc_priv_area->common.wanpipe_task.data = dev;
  
  	/* Allocate and initialize BH circular buffer */
  	/* Add 1 to MAX_BH_BUFF so we don't have test with (MAX_BH_BUFF-1) */
  	chdlc_priv_area->bh_head = kmalloc((sizeof(bh_data_t)*(MAX_BH_BUFF+1)),GFP_ATOMIC);
  	memset(chdlc_priv_area->bh_head,0,(sizeof(bh_data_t)*(MAX_BH_BUFF+1)));
  	atomic_set(&chdlc_priv_area->bh_buff_used, 0);
  #endif
   
  	do_gettimeofday(&tv);
  	chdlc_priv_area->router_start_time = tv.tv_sec;
  
  #ifdef LINUX_2_4
  	netif_start_queue(dev);
  #else
  	dev->interrupt = 0;
  	dev->tbusy = 0;
  	dev->start = 1;
  #endif
  
  	wanpipe_open(card);
  
  	/* TTY is configured during wanpipe_set_termios
  	 * call, not here */
  	if (card->tty_opt)
  		return err;
  	
  	set_bit(0,&chdlc_priv_area->config_chdlc);
  	chdlc_priv_area->config_chdlc_timeout=jiffies;
  	del_timer(&chdlc_priv_area->poll_delay_timer);
  
  	/* Start the CHDLC configuration after 1sec delay.
  	 * This will give the interface initilization time
  	 * to finish its configuration */
  	chdlc_priv_area->poll_delay_timer.expires=jiffies+HZ;
  	add_timer(&chdlc_priv_area->poll_delay_timer);
  	return err;
  }
  
  /*============================================================================
   * Close network interface.
   * o if this is the last close, then disable communications and interrupts.
   * o reset flags.
   */
  static int if_close (netdevice_t* dev)
  {
  	chdlc_private_area_t* chdlc_priv_area = dev->priv;
  	sdla_t* card = chdlc_priv_area->card;
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  
  	if (chdlc_priv_area->bh_head){
  		int i;
  		struct sk_buff *skb;
  	
  		for (i=0; i<(MAX_BH_BUFF+1); i++){
  			skb = ((bh_data_t *)&chdlc_priv_area->bh_head[i])->skb;
  			if (skb != NULL){
                  		wan_dev_kfree_skb(skb, FREE_READ);
  			}
  		}
  		kfree(chdlc_priv_area->bh_head);
  		chdlc_priv_area->bh_head=NULL;
  	}
  #endif
  
  	stop_net_queue(dev);
  #ifndef LINUX_2_4
  	dev->start=0;
  #endif
  	wanpipe_close(card);
  	del_timer(&chdlc_priv_area->poll_delay_timer);
  	return 0;
  }
  
  static void disable_comm (sdla_t *card)
  {
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  	
  	if (card->u.c.comm_enabled){
  		chdlc_disable_comm_shutdown (card);
  	}else{
  		flags->interrupt_info_struct.interrupt_permission = 0;	
  	}
  
  #if defined(LINUX_2_4) || defined(LINUX_2_1)	
  	if (!tty_init_cnt)
  		return;
  
  	if (card->tty_opt){
  		struct serial_state * state;
  		if (!(--tty_init_cnt)){
  			int e1,e2;
  			*serial_driver.refcount=0;
  			
  			if ((e1 = tty_unregister_driver(&serial_driver)))
  				printk("SERIAL: failed to unregister serial driver (%d)\n",
  				       e1);
  			if ((e2 = tty_unregister_driver(&callout_driver)))
  				printk("SERIAL: failed to unregister callout driver (%d)\n", 
  				       e2);
  			printk(KERN_INFO "%s: Unregistering TTY Driver, Major %i\n",
  					card->devname,WAN_TTY_MAJOR);
  		}
  		card->tty=NULL;
  		tty_card_map[card->tty_minor]=NULL;
  		state = &rs_table[card->tty_minor];
  		memset(state,0,sizeof(state));
  	}
  #endif
  	return;
  }
  
  
  /*============================================================================
   * 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, netdevice_t* dev,
  	unsigned short type, void* daddr, void* saddr, unsigned len)
  {
  	skb->protocol = htons(type);
  
  	return CHDLC_HDR_LEN;
  }
  
  
  #ifdef LINUX_2_4
  /*============================================================================
   * Handle transmit timeout event from netif watchdog
   */
  static void if_tx_timeout (netdevice_t *dev)
  {
      	chdlc_private_area_t* chan = dev->priv;
  	sdla_t *card = chan->card;
  	
  	/* 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.
  	 */
  
  	++card->wandev.stats.collisions;
  
  	printk (KERN_INFO "%s: Transmit timed out on %s\n", card->devname,dev->name);
  	netif_wake_queue (dev);
  }
  #endif
  
  
  
  /*============================================================================
   * Re-build media header.
   *
   * Return:	1	physical address resolved.
   *		0	physical address not resolved
   */
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  static int if_rebuild_hdr (struct sk_buff *skb)
  {
  	return 1;
  }
  #else
  static int if_rebuild_hdr (void* hdr, netdevice_t* dev, unsigned long raddr,
                             struct sk_buff* skb)
  {
          return 1;
  }
  #endif
  
  /*============================================================================
   * 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, netdevice_t* dev)
  {
  	chdlc_private_area_t *chdlc_priv_area = dev->priv;
  	sdla_t *card = chdlc_priv_area->card;
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  	INTERRUPT_INFORMATION_STRUCT *chdlc_int = &flags->interrupt_info_struct;
  	int udp_type = 0;
  	unsigned long smp_flags;
  	int err=0;
  
  #ifdef LINUX_2_4
  	netif_stop_queue(dev);
  #endif
  	
  	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);
  
  		wake_net_dev(dev);
  		return 0;
  	}
  
  #ifndef LINUX_2_4
  	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. 
  		 */
                  ++card->wandev.stats.collisions;
  		if((jiffies - chdlc_priv_area->tick_counter) < (5 * HZ)) {
  			return 1;
  		}
  
  		printk (KERN_INFO "%s: Transmit timeout !\n",
  			card->devname);
  
  		/* unbusy the interface */
  		clear_bit(0,&dev->tbusy);
  	}
  #endif
  
     	if (ntohs(skb->protocol) != htons(PVC_PROT)){
  
  		/* check the udp packet type */
  		
  		udp_type = udp_pkt_type(skb, card);
  
  		if (udp_type == UDP_CPIPE_TYPE){
                          if(store_udp_mgmt_pkt(UDP_PKT_FRM_STACK, card, skb, dev,
                                  chdlc_priv_area)){
  	                	chdlc_int->interrupt_permission |=
  					APP_INT_ON_TIMER;
  			}
  			start_net_queue(dev);
  			return 0;
  		}
  
  		/* check to see if the source IP address is a broadcast or */
  		/* multicast IP address */
                  if(chk_bcast_mcast_addr(card, dev, skb)){
  			++card->wandev.stats.tx_dropped;
  			wan_dev_kfree_skb(skb,FREE_WRITE);
  			start_net_queue(dev);
  			return 0;
  		}
          }
  
  	/* Lock the 508 Card: SMP is supported */
        	if(card->hw.type != SDLA_S514){
  		s508_lock(card,&smp_flags);
  	} 
  
      	if(test_and_set_bit(SEND_CRIT, (void*)&card->wandev.critical)) {
  	
  		printk(KERN_INFO "%s: Critical in if_send: %lx\n",
  					card->wandev.name,card->wandev.critical);
                  ++card->wandev.stats.tx_dropped;
  		start_net_queue(dev);
  		goto if_send_exit_crit;
  	}
  
  	if(card->u.c.state != WAN_CONNECTED){
         		++card->wandev.stats.tx_dropped;
  		start_net_queue(dev);
  		
  	}else if(!skb->protocol){
          	++card->wandev.stats.tx_errors;
  		start_net_queue(dev);
  		
  	}else {
  		void* data = skb->data;
  		unsigned len = skb->len;
  		unsigned char attr;
  
  		/* If it's an API packet pull off the API
  		 * header. Also check that the packet size
  		 * is larger than the API header
  	         */
  		if (card->u.c.usedby == API){
  			api_tx_hdr_t* api_tx_hdr;
  
  			/* discard the frame if we are configured for */
  			/* 'receive only' mode or if there is no data */
  			if (card->u.c.receive_only ||
  				(len <= sizeof(api_tx_hdr_t))) {
  				
  				++card->wandev.stats.tx_dropped;
  				start_net_queue(dev);
  				goto if_send_exit_crit;
  			}
  				
  			api_tx_hdr = (api_tx_hdr_t *)data;
  			attr = api_tx_hdr->attr;
  			data += sizeof(api_tx_hdr_t);
  			len -= sizeof(api_tx_hdr_t);
  		}
  
  		if(chdlc_send(card, data, len)) {
  			stop_net_queue(dev);
  		}else{
  			++card->wandev.stats.tx_packets;
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
                          card->wandev.stats.tx_bytes += len;
  #endif
  			
  			start_net_queue(dev);
  			
  #ifdef LINUX_2_4
  		 	dev->trans_start = jiffies;
  #endif
  		}	
  	}
  
  if_send_exit_crit:
  	
  	if (!(err=is_queue_stopped(dev))) {
  		wan_dev_kfree_skb(skb, FREE_WRITE);
  	}else{
  		chdlc_priv_area->tick_counter = jiffies;
  		chdlc_int->interrupt_permission |= APP_INT_ON_TX_FRAME;
  	}
  
  	clear_bit(SEND_CRIT, (void*)&card->wandev.critical);
  	if(card->hw.type != SDLA_S514){
  		s508_unlock(card,&smp_flags);
  	}
  	
  	return err;
  }
  
  
  /*============================================================================
   * Check to see if the packet to be transmitted contains a broadcast or
   * multicast source IP address.
   */
  
  static int chk_bcast_mcast_addr(sdla_t *card, netdevice_t* dev,
  				struct sk_buff *skb)
  {
  	u32 src_ip_addr;
          u32 broadcast_ip_addr = 0;
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
          struct in_device *in_dev;
  #endif
          /* read the IP source address from the outgoing packet */
          src_ip_addr = *(u32 *)(skb->data + 12);
  
  	/* read the IP broadcast address for the device */
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
          in_dev = dev->ip_ptr;
          if(in_dev != NULL) {
                  struct in_ifaddr *ifa= in_dev->ifa_list;
                  if(ifa != NULL)
                          broadcast_ip_addr = ifa->ifa_broadcast;
                  else
                          return 0;
          }
  #else
          broadcast_ip_addr = dev->pa_brdaddr;
  #endif
   
          /* check if the IP Source Address is a Broadcast address */
          if((dev->flags & IFF_BROADCAST) && (src_ip_addr == broadcast_ip_addr)) {
                  printk(KERN_INFO "%s: Broadcast Source Address silently discarded\n",
  				card->devname);
                  return 1;
          } 
  
          /* check if the IP Source Address is a Multicast address */
          if((ntohl(src_ip_addr) >= 0xE0000001) &&
  		(ntohl(src_ip_addr) <= 0xFFFFFFFE)) {
                  printk(KERN_INFO "%s: Multicast Source Address silently discarded\n",
  				card->devname);
                  return 1;
          }
  
          return 0;
  }
  
  
  /*============================================================================
   * Reply to UDP Management system.
   * Return length of reply.
   */
  static int reply_udp( unsigned char *data, unsigned int mbox_len )
  {
  
  	unsigned short len, udp_length, temp, ip_length;
  	unsigned long ip_temp;
  	int even_bound = 0;
    	chdlc_udp_pkt_t *c_udp_pkt = (chdlc_udp_pkt_t *)data;
  	 
  	/* Set length of packet */
  	len = sizeof(ip_pkt_t)+ 
  	      sizeof(udp_pkt_t)+
  	      sizeof(wp_mgmt_t)+
  	      sizeof(cblock_t)+
  	      sizeof(trace_info_t)+ 
  	      mbox_len;
  
  	/* fill in UDP reply */
  	c_udp_pkt->wp_mgmt.request_reply = UDPMGMT_REPLY;
     
  	/* fill in UDP length */
  	udp_length = sizeof(udp_pkt_t)+ 
  		     sizeof(wp_mgmt_t)+
  		     sizeof(cblock_t)+
  	             sizeof(trace_info_t)+
  		     mbox_len; 
  
   	/* put it on an even boundary */
  	if ( udp_length & 0x0001 ) {
  		udp_length += 1;
  		len += 1;
  		even_bound = 1;
  	}  
  
  	temp = (udp_length<<8)|(udp_length>>8);
  	c_udp_pkt->udp_pkt.udp_length = temp;
  		 
  	/* swap UDP ports */
  	temp = c_udp_pkt->udp_pkt.udp_src_port;
  	c_udp_pkt->udp_pkt.udp_src_port = 
  			c_udp_pkt->udp_pkt.udp_dst_port; 
  	c_udp_pkt->udp_pkt.udp_dst_port = temp;
  
  	/* add UDP pseudo header */
  	temp = 0x1100;
  	*((unsigned short *)(c_udp_pkt->data+mbox_len+even_bound)) = temp;	
  	temp = (udp_length<<8)|(udp_length>>8);
  	*((unsigned short *)(c_udp_pkt->data+mbox_len+even_bound+2)) = temp;
  
  		 
  	/* calculate UDP checksum */
  	c_udp_pkt->udp_pkt.udp_checksum = 0;
  	c_udp_pkt->udp_pkt.udp_checksum = calc_checksum(&data[UDP_OFFSET],udp_length+UDP_OFFSET);
  
  	/* fill in IP length */
  	ip_length = len;
  	temp = (ip_length<<8)|(ip_length>>8);
  	c_udp_pkt->ip_pkt.total_length = temp;
    
  	/* swap IP addresses */
  	ip_temp = c_udp_pkt->ip_pkt.ip_src_address;
  	c_udp_pkt->ip_pkt.ip_src_address = c_udp_pkt->ip_pkt.ip_dst_address;
  	c_udp_pkt->ip_pkt.ip_dst_address = ip_temp;
  
  	/* fill in IP checksum */
  	c_udp_pkt->ip_pkt.hdr_checksum = 0;
  	c_udp_pkt->ip_pkt.hdr_checksum = calc_checksum(data,sizeof(ip_pkt_t));
  
  	return len;
  
  } /* reply_udp */
  
  unsigned short calc_checksum (char *data, int len)
  {
  	unsigned short temp; 
  	unsigned long sum=0;
  	int i;
  
  	for( i = 0; i <len; i+=2 ) {
  		memcpy(&temp,&data[i],2);
  		sum += (unsigned long)temp;
  	}
  
  	while (sum >> 16 ) {
  		sum = (sum & 0xffffUL) + (sum >> 16);
  	}
  
  	temp = (unsigned short)sum;
  	temp = ~temp;
  
  	if( temp == 0 ) 
  		temp = 0xffff;
  
  	return temp;	
  }
  
  
  /*============================================================================
   * Get ethernet-style interface statistics.
   * Return a pointer to struct enet_statistics.
   */
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  static struct net_device_stats* if_stats (netdevice_t* dev)
  {
  	sdla_t *my_card;
  	chdlc_private_area_t* chdlc_priv_area;
  
  	if ((chdlc_priv_area=dev->priv) == NULL)
  		return NULL;
  
  	my_card = chdlc_priv_area->card;
  	return &my_card->wandev.stats; 
  }
  #else
  static struct enet_statistics* if_stats (netdevice_t* dev)
  {
          sdla_t *my_card;
          chdlc_private_area_t* chdlc_priv_area = dev->priv;
  
  	if ((chdlc_priv_area=dev->priv) == NULL)
  		return NULL;
  
          my_card = chdlc_priv_area->card;
          return &my_card->wandev.stats;
  }
  #endif
  
  /****** Cisco HDLC Firmware Interface Functions *******************************/
  
  /*============================================================================
   * Read firmware code version.
   *	Put code version as ASCII string in str. 
   */
  static int chdlc_read_version (sdla_t* card, char* str)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	int len;
  	char err;
  	mb->buffer_length = 0;
  	mb->command = READ_CHDLC_CODE_VERSION;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  
  	if(err != COMMAND_OK) {
  		chdlc_error(card,err,mb);
  	}
  	else if (str) {  /* is not null */
  		len = mb->buffer_length;
  		memcpy(str, mb->data, len);
  		str[len] = '\0';
  	}
  	return (err);
  }
  
  /*-----------------------------------------------------------------------------
   *  Configure CHDLC firmware.
   */
  static int chdlc_configure (sdla_t* card, void* data)
  {
  	int err;
  	CHDLC_MAILBOX_STRUCT *mailbox = card->mbox;
  	int data_length = sizeof(CHDLC_CONFIGURATION_STRUCT);
  	
  	mailbox->buffer_length = data_length;  
  	memcpy(mailbox->data, data, data_length);
  	mailbox->command = SET_CHDLC_CONFIGURATION;
  	err = sdla_exec(mailbox) ? mailbox->return_code : CMD_TIMEOUT;
  	
  	if (err != COMMAND_OK) chdlc_error (card, err, mailbox);
                             
  	return err;
  }
  
  
  /*============================================================================
   * Set interrupt mode -- HDLC Version.
   */
  
  static int chdlc_set_intr_mode (sdla_t* card, unsigned mode)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	CHDLC_INT_TRIGGERS_STRUCT* int_data =
  		 (CHDLC_INT_TRIGGERS_STRUCT *)mb->data;
  	int err;
  
  	int_data->CHDLC_interrupt_triggers 	= mode;
  	int_data->IRQ				= card->hw.irq;
  	int_data->interrupt_timer               = 1;
     
  	mb->buffer_length = sizeof(CHDLC_INT_TRIGGERS_STRUCT);
  	mb->command = SET_CHDLC_INTERRUPT_TRIGGERS;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	if (err != COMMAND_OK)
  		chdlc_error (card, err, mb);
  	return err;
  }
  
  
  /*===========================================================
   * chdlc_disable_comm_shutdown
   *
   * Shutdown() disables the communications. We must
   * have a sparate functions, because we must not
   * call chdlc_error() hander since the private
   * area has already been replaced */
  
  static int chdlc_disable_comm_shutdown (sdla_t *card)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	CHDLC_INT_TRIGGERS_STRUCT* int_data =
  		 (CHDLC_INT_TRIGGERS_STRUCT *)mb->data;
  	int err;
  
  	/* Disable Interrutps */
  	int_data->CHDLC_interrupt_triggers 	= 0;
  	int_data->IRQ				= card->hw.irq;
  	int_data->interrupt_timer               = 1;
     
  	mb->buffer_length = sizeof(CHDLC_INT_TRIGGERS_STRUCT);
  	mb->command = SET_CHDLC_INTERRUPT_TRIGGERS;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  
  	/* Disable Communications */
  
  	if (card->u.c.async_mode) {
  		mb->command = DISABLE_ASY_COMMUNICATIONS;
  	}else{
  		mb->command = DISABLE_CHDLC_COMMUNICATIONS;
  	}
  	
  	mb->buffer_length = 0;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	
  	card->u.c.comm_enabled = 0;
  	
  	return 0;
  }
  
  /*============================================================================
   * Enable communications.
   */
  
  static int chdlc_comm_enable (sdla_t* card)
  {
  	int err;
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  
  	mb->buffer_length = 0;
  	mb->command = ENABLE_CHDLC_COMMUNICATIONS;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	if (err != COMMAND_OK)
  		chdlc_error(card, err, mb);
  	else
  		card->u.c.comm_enabled = 1;
  	
  	return err;
  }
  
  /*============================================================================
   * Read communication error statistics.
   */
  static int chdlc_read_comm_err_stats (sdla_t* card)
  {
          int err;
          CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  
          mb->buffer_length = 0;
          mb->command = READ_COMMS_ERROR_STATS;
          err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
          if (err != COMMAND_OK)
                  chdlc_error(card,err,mb);
          return err;
  }
  
  
  /*============================================================================
   * Read CHDLC operational statistics.
   */
  static int chdlc_read_op_stats (sdla_t* card)
  {
          int err;
          CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  
          mb->buffer_length = 0;
          mb->command = READ_CHDLC_OPERATIONAL_STATS;
          err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
          if (err != COMMAND_OK)
                  chdlc_error(card,err,mb);
          return err;
  }
  
  
  /*============================================================================
   * Update communications error and general packet statistics.
   */
  static int update_comms_stats(sdla_t* card,
  	chdlc_private_area_t* chdlc_priv_area)
  {
          CHDLC_MAILBOX_STRUCT* mb = card->mbox;
    	COMMS_ERROR_STATS_STRUCT* err_stats;
          CHDLC_OPERATIONAL_STATS_STRUCT *op_stats;
  
  	/* on the first timer interrupt, read the comms error statistics */
  	if(chdlc_priv_area->update_comms_stats == 2) {
  		if(chdlc_read_comm_err_stats(card))
  			return 1;
  		err_stats = (COMMS_ERROR_STATS_STRUCT *)mb->data;
  		card->wandev.stats.rx_over_errors = 
  				err_stats->Rx_overrun_err_count;
  		card->wandev.stats.rx_crc_errors = 
  				err_stats->CRC_err_count;
  		card->wandev.stats.rx_frame_errors = 
  				err_stats->Rx_abort_count;
  		card->wandev.stats.rx_fifo_errors = 
  				err_stats->Rx_dis_pri_bfrs_full_count; 
  		card->wandev.stats.rx_missed_errors =
  				card->wandev.stats.rx_fifo_errors;
  		card->wandev.stats.tx_aborted_errors =
  				err_stats->sec_Tx_abort_count;
  	}
  
          /* on the second timer interrupt, read the operational statistics */
  	else {
          	if(chdlc_read_op_stats(card))
                  	return 1;
  		op_stats = (CHDLC_OPERATIONAL_STATS_STRUCT *)mb->data;
  		card->wandev.stats.rx_length_errors =
  			(op_stats->Rx_Data_discard_short_count +
  			op_stats->Rx_Data_discard_long_count);
  	}
  
  	return 0;
  }
  
  /*============================================================================
   * Send packet.
   *	Return:	0 - o.k.
   *		1 - no transmit buffers available
   */
  static int chdlc_send (sdla_t* card, void* data, unsigned len)
  {
  	CHDLC_DATA_TX_STATUS_EL_STRUCT *txbuf = card->u.c.txbuf;
  
  	if (txbuf->opp_flag)
  		return 1;
  	
  	sdla_poke(&card->hw, txbuf->ptr_data_bfr, data, len);
  
  	txbuf->frame_length = len;
  	txbuf->opp_flag = 1;		/* start transmission */
  	
  	/* Update transmit buffer control fields */
  	card->u.c.txbuf = ++txbuf;
  	
  	if ((void*)txbuf > card->u.c.txbuf_last)
  		card->u.c.txbuf = card->u.c.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 chdlc_error (sdla_t *card, int err, CHDLC_MAILBOX_STRUCT *mb)
  {
  	unsigned cmd = mb->command;
  
  	switch (err) {
  
  	case CMD_TIMEOUT:
  		printk(KERN_INFO "%s: command 0x%02X timed out!\n",
  			card->devname, cmd);
  		break;
  
  	case S514_BOTH_PORTS_SAME_CLK_MODE:
  		if(cmd == SET_CHDLC_CONFIGURATION) {
  			printk(KERN_INFO
  			 "%s: Configure both ports for the same clock source\n",
  				card->devname);
  			break;
  		}
  
  	default:
  		printk(KERN_INFO "%s: command 0x%02X returned 0x%02X!\n",
  			card->devname, cmd, err);
  	}
  
  	return 0;
  }
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  /********** Bottom Half Handlers ********************************************/
  
  /* NOTE: There is no API, BH support for Kernels lower than 2.2.X.
   *       DO NOT INSERT ANY CODE HERE, NOTICE THE 
   *       PREPROCESSOR STATEMENT ABOVE, UNLESS YOU KNOW WHAT YOU ARE
   *       DOING */
  
  static void chdlc_bh (netdevice_t * dev)
  {
  	chdlc_private_area_t* chan = dev->priv;
  	sdla_t *card = chan->card;
  	struct sk_buff *skb;
  
  	if (atomic_read(&chan->bh_buff_used) == 0){
  		clear_bit(0, &chan->tq_working);
  		return;
  	}
  
  	while (atomic_read(&chan->bh_buff_used)){
  
  		skb  = ((bh_data_t *)&chan->bh_head[chan->bh_read])->skb;
  
  		if (skb != NULL){
  
  			if (chan->common.sk == NULL || chan->common.func == NULL){
  				++card->wandev.stats.rx_dropped;
  				wan_dev_kfree_skb(skb, FREE_READ);
  				chdlc_bh_cleanup(dev);
  				continue;
  			}
  
  			if (chan->common.func(skb,dev,chan->common.sk) != 0){
  				/* Sock full cannot send, queue us for another
                                   * try */
  				atomic_set(&chan->common.receive_block,1);
  				return;
  			}else{
  				chdlc_bh_cleanup(dev);
  			}
  		}else{
  			chdlc_bh_cleanup(dev);
  		}
  	}	
  	clear_bit(0, &chan->tq_working);
  
  	return;
  }
  
  static int chdlc_bh_cleanup (netdevice_t *dev)
  {
  	chdlc_private_area_t* chan = dev->priv;
  
  	((bh_data_t *)&chan->bh_head[chan->bh_read])->skb = NULL;
  
  	if (chan->bh_read == MAX_BH_BUFF){
  		chan->bh_read=0;
  	}else{
  		++chan->bh_read;	
  	}
  
  	atomic_dec(&chan->bh_buff_used);
  	return 0;
  }
  
  
  
  static int bh_enqueue (netdevice_t *dev, struct sk_buff *skb)
  {
  	/* Check for full */
  	chdlc_private_area_t* chan = dev->priv;
  	sdla_t *card = chan->card;
  
  	if (atomic_read(&chan->bh_buff_used) == (MAX_BH_BUFF+1)){
  		++card->wandev.stats.rx_dropped;
  		wan_dev_kfree_skb(skb, FREE_READ);
  		return 1; 
  	}
  
  	((bh_data_t *)&chan->bh_head[chan->bh_write])->skb = skb;
  
  	if (chan->bh_write == MAX_BH_BUFF){
  		chan->bh_write=0;
  	}else{
  		++chan->bh_write;
  	}
  
  	atomic_inc(&chan->bh_buff_used);
  
  	return 0;
  }
  
  /* END OF API BH Support */
  
  #endif
  
  /****** Interrupt Handlers **************************************************/
  
  /*============================================================================
   * Cisco HDLC interrupt service routine.
   */
  static void wpc_isr (sdla_t* card)
  {
  	netdevice_t* dev;
  	SHARED_MEMORY_INFO_STRUCT* flags = NULL;
  	int i;
  	sdla_t *my_card;
  
  
  	/* Check for which port the interrupt has been generated
  	 * Since Secondary Port is piggybacking on the Primary
           * the check must be done here. 
  	 */
  
  	flags = card->u.c.flags;
  	if (!flags->interrupt_info_struct.interrupt_type){
  		/* Check for a second port (piggybacking) */
  		if ((my_card = card->next)){
  			flags = my_card->u.c.flags;
  			if (flags->interrupt_info_struct.interrupt_type){
  				card = my_card;
  				card->isr(card);
  				return;
  			}
  		}
  	}
  
  	flags = card->u.c.flags;
  	card->in_isr = 1;
  	dev = card->wandev.dev;
  	
  	/* If we get an interrupt with no network device, stop the interrupts
  	 * and issue an error */
  	if (!card->tty_opt && !dev && 
  	    flags->interrupt_info_struct.interrupt_type != 
  	    	COMMAND_COMPLETE_APP_INT_PEND){
  
  		goto isr_done;
  	}
  	
  	/* if critical due to peripheral operations
  	 * ie. update() or getstats() then reset the interrupt and
  	 * wait for the board to retrigger.
  	 */
  	if(test_bit(PERI_CRIT, (void*)&card->wandev.critical)) {
  		printk(KERN_INFO "ISR CRIT TO PERI\n");
  		goto isr_done;
  	}
  
  	/* On a 508 Card, if critical due to if_send 
           * Major Error !!! */
  	if(card->hw.type != SDLA_S514) {
  		if(test_bit(SEND_CRIT, (void*)&card->wandev.critical)) {
  			printk(KERN_INFO "%s: Critical while in ISR: %lx\n",
  				card->devname, card->wandev.critical);
  			card->in_isr = 0;
  			flags->interrupt_info_struct.interrupt_type = 0;
  			return;
  		}
  	}
  
  	switch(flags->interrupt_info_struct.interrupt_type) {
  
  	case RX_APP_INT_PEND:	/* 0x01: receive interrupt */
  		rx_intr(card);
  		break;
  
  	case TX_APP_INT_PEND:	/* 0x02: transmit interrupt */
  		flags->interrupt_info_struct.interrupt_permission &=
  			 ~APP_INT_ON_TX_FRAME;
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  
  		if (card->tty_opt){
  			wanpipe_tty_trigger_poll(card);
  			break;
  		}
  
  		if (dev && is_queue_stopped(dev)){
  			if (card->u.c.usedby == API){
  				start_net_queue(dev);
  				wakeup_sk_bh(dev);
  			}else{
  				wake_net_dev(dev);
  			}
  		}
  #else
  		wake_net_dev(dev);
  #endif
  		break;
  
  	case COMMAND_COMPLETE_APP_INT_PEND:/* 0x04: cmd cplt */
  		++ Intr_test_counter;
  		break;
  
  	case CHDLC_EXCEP_COND_APP_INT_PEND:	/* 0x20 */
  		process_chdlc_exception(card);
  		break;
  
  	case GLOBAL_EXCEP_COND_APP_INT_PEND:
  		process_global_exception(card);
  		break;
  
  	case TIMER_APP_INT_PEND:
  		timer_intr(card);
  		break;
  
  	default:
  		printk(KERN_INFO "%s: spurious interrupt 0x%02X!\n", 
  			card->devname,
  			flags->interrupt_info_struct.interrupt_type);
  		printk(KERN_INFO "Code name: ");
  		for(i = 0; i < 4; i ++)
  			printk(KERN_INFO "%c",
  				flags->global_info_struct.codename[i]); 
  		printk(KERN_INFO "\nCode version: ");
  	 	for(i = 0; i < 4; i ++)
  			printk(KERN_INFO "%c", 
  				flags->global_info_struct.codeversion[i]); 
  		printk(KERN_INFO "\n");	
  		break;
  	}
  
  isr_done:
  
  	card->in_isr = 0;
  	flags->interrupt_info_struct.interrupt_type = 0;
  	return;
  }
  
  /*============================================================================
   * Receive interrupt handler.
   */
  static void rx_intr (sdla_t* card)
  {
  	netdevice_t *dev;
  	chdlc_private_area_t *chdlc_priv_area;
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  	CHDLC_DATA_RX_STATUS_EL_STRUCT *rxbuf = card->u.c.rxmb;
  	struct sk_buff *skb;
  	unsigned len;
  	unsigned addr = rxbuf->ptr_data_bfr;
  	void *buf;
  	int i,udp_type;
  
  	if (rxbuf->opp_flag != 0x01) {
  		printk(KERN_INFO 
  			"%s: corrupted Rx buffer @ 0x%X, flag = 0x%02X!\n", 
  			card->devname, (unsigned)rxbuf, rxbuf->opp_flag);
                  printk(KERN_INFO "Code name: ");
                  for(i = 0; i < 4; i ++)
                          printk(KERN_INFO "%c",
                                  flags->global_info_struct.codename[i]);
                  printk(KERN_INFO "\nCode version: ");
                  for(i = 0; i < 4; i ++)
                          printk(KERN_INFO "%c",
                                  flags->global_info_struct.codeversion[i]);
                  printk(KERN_INFO "\n");
  
  
  		/* Bug Fix: Mar 6 2000
                   * If we get a corrupted mailbox, it measn that driver 
                   * is out of sync with the firmware. There is no recovery.
                   * If we don't turn off all interrupts for this card
                   * the machine will crash. 
                   */
  		printk(KERN_INFO "%s: Critical router failure ...!!!\n", card->devname);
  		printk(KERN_INFO "Please contact Sangoma Technologies !\n");
  		chdlc_set_intr_mode(card,0);	
  		return;
  	}
  
  	len  = rxbuf->frame_length;
  
  #if defined(LINUX_2_4) || defined(LINUX_2_1)	
  	if (card->tty_opt){
  
  		if (rxbuf->error_flag){	
  			goto rx_exit;
  		}
  
  		if (len <= CRC_LENGTH){
  			goto rx_exit;
  		}
  		
  		if (!card->u.c.async_mode){
  			len -= CRC_LENGTH;
  		}
  
  		wanpipe_tty_receive(card,addr,len);
  		goto rx_exit;
  	}
  #endif
  
  	dev = card->wandev.dev;
  
  	if (!dev){
  		goto rx_exit;
  	}
  
  	if (!is_dev_running(dev))
  		goto rx_exit;
  
  	chdlc_priv_area = dev->priv;
  
  	
  	/* Allocate socket buffer */
  	skb = dev_alloc_skb(len);
  
  	if (skb == NULL) {
  		printk(KERN_INFO "%s: no socket buffers available!\n",
  					card->devname);
  		++card->wandev.stats.rx_dropped;
  		goto rx_exit;
  	}
  
  	/* Copy data to the socket buffer */
  	if((addr + len) > card->u.c.rx_top + 1) {
  		unsigned tmp = card->u.c.rx_top - addr + 1;
  		buf = skb_put(skb, tmp);
  		sdla_peek(&card->hw, addr, buf, tmp);
  		addr = card->u.c.rx_base;
  		len -= tmp;
  	}
  		
  	buf = skb_put(skb, len);
  	sdla_peek(&card->hw, addr, buf, len);
  
  	skb->protocol = htons(ETH_P_IP);
  
  	card->wandev.stats.rx_packets ++;
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	card->wandev.stats.rx_bytes += skb->len;
  #endif
  	udp_type = udp_pkt_type( skb, card );
  
  	if(udp_type == UDP_CPIPE_TYPE) {
  		if(store_udp_mgmt_pkt(UDP_PKT_FRM_NETWORK,
     				      card, skb, dev, chdlc_priv_area)) {
       		        flags->interrupt_info_struct.
  						interrupt_permission |= 
  							APP_INT_ON_TIMER; 
  		}
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	} else if(card->u.c.usedby == API) {
  
  		api_rx_hdr_t* api_rx_hdr;
         		skb_push(skb, sizeof(api_rx_hdr_t));
                  api_rx_hdr = (api_rx_hdr_t*)&skb->data[0x00];
  		api_rx_hdr->error_flag = rxbuf->error_flag;
       		api_rx_hdr->time_stamp = rxbuf->time_stamp;
  
                  skb->protocol = htons(PVC_PROT);
       		skb->mac.raw  = skb->data;
  		skb->dev      = dev;
                 	skb->pkt_type = WAN_PACKET_DATA;
  
  		bh_enqueue(dev, skb);
  
  		if (!test_and_set_bit(0,&chdlc_priv_area->tq_working)){
  			wanpipe_queue_tq(&chdlc_priv_area->common.wanpipe_task);
  		        wanpipe_mark_bh();
  		}
  #endif
  	}else{
                 	/* Pass it up the protocol stack */
  	
                  skb->dev = dev;
                  skb->mac.raw  = skb->data;
                  netif_rx(skb);
  	}
  
  rx_exit:
  	/* Release buffer element and calculate a pointer to the next one */
  	rxbuf->opp_flag = 0x00;
  	card->u.c.rxmb = ++ rxbuf;
  	if((void*)rxbuf > card->u.c.rxbuf_last){
  		card->u.c.rxmb = card->u.c.rxbuf_base;
  	}
  }
  
  /*============================================================================
   * Timer interrupt handler.
   * The timer interrupt is used for two purposes:
   *    1) Processing udp calls from 'cpipemon'.
   *    2) Reading board-level statistics for updating the proc file system.
   */
  void timer_intr(sdla_t *card)
  {
          netdevice_t* dev;
          chdlc_private_area_t* chdlc_priv_area = NULL;
          SHARED_MEMORY_INFO_STRUCT* flags = NULL;
  
          if ((dev = card->wandev.dev)==NULL){
  		flags = card->u.c.flags;
                  flags->interrupt_info_struct.interrupt_permission &=
                          ~APP_INT_ON_TIMER;
  		return;
  	}
  	
          chdlc_priv_area = dev->priv;
  
  	if (chdlc_priv_area->timer_int_enabled & TMR_INT_ENABLED_CONFIG) {
  		if (!config_chdlc(card)){
  			chdlc_priv_area->timer_int_enabled &= ~TMR_INT_ENABLED_CONFIG;
  		}
  	}
  
  	/* process a udp call if pending */
         	if(chdlc_priv_area->timer_int_enabled & TMR_INT_ENABLED_UDP) {
                 	process_udp_mgmt_pkt(card, dev,
                         chdlc_priv_area);
  		chdlc_priv_area->timer_int_enabled &= ~TMR_INT_ENABLED_UDP;
          }
  
  	/* read the communications statistics if required */
  	if(chdlc_priv_area->timer_int_enabled & TMR_INT_ENABLED_UPDATE) {
  		update_comms_stats(card, chdlc_priv_area);
                  if(!(-- chdlc_priv_area->update_comms_stats)) {
  			chdlc_priv_area->timer_int_enabled &= 
  				~TMR_INT_ENABLED_UPDATE;
  		}
          }
  
  	/* only disable the timer interrupt if there are no udp or statistic */
  	/* updates pending */
          if(!chdlc_priv_area->timer_int_enabled) {
                  flags = card->u.c.flags;
                  flags->interrupt_info_struct.interrupt_permission &=
                          ~APP_INT_ON_TIMER;
          }
  }
  
  /*------------------------------------------------------------------------------
    Miscellaneous Functions
  	- set_chdlc_config() used to set configuration options on the board
  ------------------------------------------------------------------------------*/
  
  static int set_chdlc_config(sdla_t* card)
  {
  	CHDLC_CONFIGURATION_STRUCT cfg;
  
  	memset(&cfg, 0, sizeof(CHDLC_CONFIGURATION_STRUCT));
  
  	if(card->wandev.clocking){
  		cfg.baud_rate = card->wandev.bps;
  	}
  		
  	cfg.line_config_options = (card->wandev.interface == WANOPT_RS232) ?
  		INTERFACE_LEVEL_RS232 : INTERFACE_LEVEL_V35;
  
  	cfg.modem_config_options	= 0;
  	cfg.modem_status_timer		= 100;
  
  	cfg.CHDLC_protocol_options	= card->u.c.protocol_options;
  
  	if (card->tty_opt){
  		cfg.CHDLC_API_options	= DISCARD_RX_ERROR_FRAMES;
  	}
  	
  	cfg.percent_data_buffer_for_Tx  = (card->u.c.receive_only) ? 0 : 50;
  	cfg.CHDLC_statistics_options	= (CHDLC_TX_DATA_BYTE_COUNT_STAT |
  		CHDLC_RX_DATA_BYTE_COUNT_STAT);
  	
  	if (card->tty_opt){
  		card->wandev.mtu = TTY_CHDLC_MAX_MTU;
  	}
  	cfg.max_CHDLC_data_field_length	= card->wandev.mtu;
  	cfg.transmit_keepalive_timer	= card->u.c.kpalv_tx;
  	cfg.receive_keepalive_timer	= card->u.c.kpalv_rx;
  	cfg.keepalive_error_tolerance	= card->u.c.kpalv_err;
  	cfg.SLARP_request_timer		= card->u.c.slarp_timer;
  
  	if (cfg.SLARP_request_timer) {
  		cfg.IP_address		= 0;
  		cfg.IP_netmask		= 0;
  		
  	}else if (card->wandev.dev){
  		netdevice_t * dev = card->wandev.dev;
  		chdlc_private_area_t *chdlc_priv_area = dev->priv;
  		
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
                  struct in_device *in_dev = dev->ip_ptr;
  
  		if(in_dev != NULL) {
  			struct in_ifaddr *ifa = in_dev->ifa_list;
  
  			if (ifa != NULL ) {
  				cfg.IP_address	= ntohl(ifa->ifa_local);
  				cfg.IP_netmask	= ntohl(ifa->ifa_mask); 
  				chdlc_priv_area->IP_address = ntohl(ifa->ifa_local);
  				chdlc_priv_area->IP_netmask = ntohl(ifa->ifa_mask); 
  			}
  		}
  #else
                  cfg.IP_address          = ntohl(dev->pa_addr);
                  cfg.IP_netmask          = ntohl(dev->pa_mask);
  		chdlc_priv_area->IP_address = ntohl(dev->pa_addr);
  		chdlc_priv_area->IP_netmask = ntohl(dev->pa_mask);
  #endif
  
  	}
  	
  	return chdlc_configure(card, &cfg);
  }
  
  
  /*-----------------------------------------------------------------------------
     set_asy_config() used to set asynchronous configuration options on the board
  ------------------------------------------------------------------------------*/
  
  static int set_asy_config(sdla_t* card)
  {
  
          ASY_CONFIGURATION_STRUCT cfg;
   	CHDLC_MAILBOX_STRUCT *mailbox = card->mbox;
  	int err;
  
  	memset(&cfg, 0, sizeof(ASY_CONFIGURATION_STRUCT));
  
  	if(card->wandev.clocking)
  		cfg.baud_rate = card->wandev.bps;
  
  	cfg.line_config_options = (card->wandev.interface == WANOPT_RS232) ?
  		INTERFACE_LEVEL_RS232 : INTERFACE_LEVEL_V35;
  
  	cfg.modem_config_options	= 0;
  	cfg.asy_API_options 		= card->u.c.api_options;
  	cfg.asy_protocol_options	= card->u.c.protocol_options;
  	cfg.Tx_bits_per_char		= card->u.c.tx_bits_per_char;
  	cfg.Rx_bits_per_char		= card->u.c.rx_bits_per_char;
  	cfg.stop_bits			= card->u.c.stop_bits;
  	cfg.parity			= card->u.c.parity;
  	cfg.break_timer			= card->u.c.break_timer;
  	cfg.asy_Rx_inter_char_timer	= card->u.c.inter_char_timer; 
  	cfg.asy_Rx_complete_length	= card->u.c.rx_complete_length; 
  	cfg.XON_char			= card->u.c.xon_char;
  	cfg.XOFF_char			= card->u.c.xoff_char;
  	cfg.asy_statistics_options	= (CHDLC_TX_DATA_BYTE_COUNT_STAT |
  		CHDLC_RX_DATA_BYTE_COUNT_STAT);
  
  	mailbox->buffer_length = sizeof(ASY_CONFIGURATION_STRUCT);
  	memcpy(mailbox->data, &cfg, mailbox->buffer_length);
  	mailbox->command = SET_ASY_CONFIGURATION;
  	err = sdla_exec(mailbox) ? mailbox->return_code : CMD_TIMEOUT;
  	if (err != COMMAND_OK) 
  		chdlc_error (card, err, mailbox);
  	return err;
  }
  
  /*============================================================================
   * Enable asynchronous communications.
   */
  
  static int asy_comm_enable (sdla_t* card)
  {
  
  	int err;
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  
  	mb->buffer_length = 0;
  	mb->command = ENABLE_ASY_COMMUNICATIONS;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	if (err != COMMAND_OK && card->wandev.dev)
  		chdlc_error(card, err, mb);
  	
  	if (!err)
  		card->u.c.comm_enabled = 1;
  
  	return err;
  }
  
  /*============================================================================
   * Process global exception condition
   */
  static int process_global_exception(sdla_t *card)
  {
  	CHDLC_MAILBOX_STRUCT* mbox = card->mbox;
  	int err;
  
  	mbox->buffer_length = 0;
  	mbox->command = READ_GLOBAL_EXCEPTION_CONDITION;
  	err = sdla_exec(mbox) ? mbox->return_code : CMD_TIMEOUT;
  
  	if(err != CMD_TIMEOUT ){
  	
  		switch(mbox->return_code) {
           
  	      	case EXCEP_MODEM_STATUS_CHANGE:
  
  			printk(KERN_INFO "%s: Modem status change\n",
  				card->devname);
  
  			switch(mbox->data[0] & (DCD_HIGH | CTS_HIGH)) {
  				case (DCD_HIGH):
  					printk(KERN_INFO "%s: DCD high, CTS low\n",card->devname);
  					break;
  				case (CTS_HIGH):
                                          printk(KERN_INFO "%s: DCD low, CTS high\n",card->devname); 
  					break;
                                  case ((DCD_HIGH | CTS_HIGH)):
                                          printk(KERN_INFO "%s: DCD high, CTS high\n",card->devname);
                                          break;
  				default:
                                          printk(KERN_INFO "%s: DCD low, CTS low\n",card->devname);
                                          break;
  			}
  			break;
  
                  case EXCEP_TRC_DISABLED:
                          printk(KERN_INFO "%s: Line trace disabled\n",
  				card->devname);
                          break;
  
  		case EXCEP_IRQ_TIMEOUT:
  			printk(KERN_INFO "%s: IRQ timeout occurred\n",
  				card->devname); 
  			break;
  
  		case 0x17:
  			if (card->tty_opt){
  				if (card->tty && card->tty_open){ 
  					printk(KERN_INFO 
  						"%s: Modem Hangup Exception: Hanging Up!\n",
  						card->devname);
  					tty_hangup(card->tty);
  				}
  				break;
  			}
  
  			/* If TTY is not used just drop throught */
  			
                  default:
                          printk(KERN_INFO "%s: Global exception %x\n",
  				card->devname, mbox->return_code);
                          break;
                  }
  	}
  	return 0;
  }
  
  
  /*============================================================================
   * Process chdlc exception condition
   */
  static int process_chdlc_exception(sdla_t *card)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	int err;
  
  	mb->buffer_length = 0;
  	mb->command = READ_CHDLC_EXCEPTION_CONDITION;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	if(err != CMD_TIMEOUT) {
  	
  		switch (err) {
  
  		case EXCEP_LINK_ACTIVE:
  			port_set_state(card, WAN_CONNECTED);
  			trigger_chdlc_poll(card->wandev.dev);
  			break;
  
  		case EXCEP_LINK_INACTIVE_MODEM:
  			port_set_state(card, WAN_DISCONNECTED);
  			unconfigure_ip(card);
  			trigger_chdlc_poll(card->wandev.dev);
  			break;
  
  		case EXCEP_LINK_INACTIVE_KPALV:
  			port_set_state(card, WAN_DISCONNECTED);
  			printk(KERN_INFO "%s: Keepalive timer expired.\n",
  				 		card->devname);
  			unconfigure_ip(card);
  			trigger_chdlc_poll(card->wandev.dev);
  			break;
  
  		case EXCEP_IP_ADDRESS_DISCOVERED:
  			if (configure_ip(card)) 
  				return -1;
  			break;
  
  		case EXCEP_LOOPBACK_CONDITION:
  			printk(KERN_INFO "%s: Loopback Condition Detected.\n",
  						card->devname);
  			break;
  
  		case NO_CHDLC_EXCEP_COND_TO_REPORT:
  			printk(KERN_INFO "%s: No exceptions reported.\n",
  						card->devname);
  			break;
  		}
  
  	}
  	return 0;
  }
  
  
  /*============================================================================
   * Configure IP from SLARP negotiation
   * This adds dynamic routes when SLARP has provided valid addresses
   */
  
  static int configure_ip (sdla_t* card)
  {
  	netdevice_t *dev = card->wandev.dev;
          chdlc_private_area_t *chdlc_priv_area;
          char err;
  
  	if (!dev)
  		return 0;
  
  	chdlc_priv_area = dev->priv;
  	
  	
          /* set to discover */
          if(card->u.c.slarp_timer != 0x00) {
  		CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  		CHDLC_CONFIGURATION_STRUCT *cfg;
  
       		mb->buffer_length = 0;
  		mb->command = READ_CHDLC_CONFIGURATION;
  		err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	
  		if(err != COMMAND_OK) {
  			chdlc_error(card,err,mb);
  			return -1;
  		}
  
  		cfg = (CHDLC_CONFIGURATION_STRUCT *)mb->data;
                  chdlc_priv_area->IP_address = cfg->IP_address;
                  chdlc_priv_area->IP_netmask = cfg->IP_netmask;
  
  		/* Set flag to add route */
  		chdlc_priv_area->route_status = ADD_ROUTE;
  
  		/* The idea here is to add the route in the poll routine.
  	   	This way, we aren't in interrupt context when adding routes */
  		trigger_chdlc_poll(dev);
          }
  
  	return 0;
  }
  
  
  /*============================================================================
   * Un-Configure IP negotiated by SLARP
   * This removes dynamic routes when the link becomes inactive.
   */
  
  static int unconfigure_ip (sdla_t* card)
  {
  	netdevice_t *dev = card->wandev.dev;
  	chdlc_private_area_t *chdlc_priv_area;
  
  	if (!dev)
  		return 0;
  
  	chdlc_priv_area= dev->priv;
  	
  	if (chdlc_priv_area->route_status == ROUTE_ADDED) {
  
  		/* Note: If this function is called, the 
                   * port state has been DISCONNECTED.  This state
                   * change will trigger a poll_disconnected 
                   * function, that will check for this condition. 
  		 */
  		chdlc_priv_area->route_status = REMOVE_ROUTE;
  
  	}
  	return 0;
  }
  
  /*============================================================================
   * Routine to add/remove routes 
   * Called like a polling routine when Routes are flagged to be added/removed.
   */
  
  static void process_route (sdla_t *card)
  {
          netdevice_t *dev = card->wandev.dev;
          unsigned char port_num;
          chdlc_private_area_t *chdlc_priv_area = NULL;
  	u32 local_IP_addr = 0;
  	u32 remote_IP_addr = 0;
  	u32 IP_netmask, IP_addr;
          int err = 0;
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  	struct in_device *in_dev;
  	mm_segment_t fs;
  	struct ifreq if_info;
          struct sockaddr_in *if_data1, *if_data2;
  #else
  	unsigned long fs = 0;
          struct rtentry route;
  #endif
  	
          chdlc_priv_area = dev->priv;
          port_num = card->u.c.comm_port;
  
  	/* Bug Fix Mar 16 2000
  	 * AND the IP address to the Mask before checking
           * the last two bits. */
  
  	if((chdlc_priv_area->route_status == ADD_ROUTE) &&
  		((chdlc_priv_area->IP_address & ~chdlc_priv_area->IP_netmask) > 2)) {
  
  		printk(KERN_INFO "%s: Dynamic route failure.\n",card->devname);
  
                  if(card->u.c.slarp_timer) {
  			u32 addr_net = htonl(chdlc_priv_area->IP_address);
  
  			printk(KERN_INFO "%s: Bad IP address %u.%u.%u.%u received\n",
  				card->devname,
  			       NIPQUAD(addr_net));
                          printk(KERN_INFO "%s: from remote station.\n",
  				card->devname);
  
                  }else{ 
  			u32 addr_net = htonl(chdlc_priv_area->IP_address);
  
                          printk(KERN_INFO "%s: Bad IP address %u.%u.%u.%u issued\n",
  			       card->devname,
  			       NIPQUAD(addr_net));
                          printk(KERN_INFO "%s: to remote station. Local\n",
  				card->devname);
  			printk(KERN_INFO "%s: IP address must be A.B.C.1\n",
  				card->devname);
  			printk(KERN_INFO "%s: or A.B.C.2.\n",card->devname);
  		}
  
  		/* remove the route due to the IP address error condition */
  		chdlc_priv_area->route_status = REMOVE_ROUTE;
  		err = 1;
     	}
  
  	/* If we are removing a route with bad IP addressing, then use the */
  	/* locally configured IP addresses */
          if((chdlc_priv_area->route_status == REMOVE_ROUTE) && err) {
  
   	        /* do not remove a bad route that has already been removed */
          	if(chdlc_priv_area->route_removed) {
  	                return;
          	}
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
                  in_dev = dev->ip_ptr;
  
                  if(in_dev != NULL) {
                          struct in_ifaddr *ifa = in_dev->ifa_list;
                          if (ifa != NULL ) {
                                  local_IP_addr = ifa->ifa_local;
                                  IP_netmask  = ifa->ifa_mask;
                          }
                  }
  #else
                  local_IP_addr = dev->pa_addr;
                  remote_IP_addr = dev->pa_dstaddr;
                  IP_netmask = dev->pa_mask;
  #endif
  	}else{ 
         		/* According to Cisco HDLC, if the point-to-point address is
  		   A.B.C.1, then we are the opposite (A.B.C.2), and vice-versa.
  		*/
  		IP_netmask = ntohl(chdlc_priv_area->IP_netmask);
  	        remote_IP_addr = ntohl(chdlc_priv_area->IP_address);
  	
  
  		/* If Netmask is 255.255.255.255 the local address
                   * calculation will fail. Default it back to 255.255.255.0 */
  		if (IP_netmask == 0xffffffff)
  			IP_netmask &= 0x00ffffff;
  
  		/* Bug Fix Mar 16 2000
  		 * AND the Remote IP address with IP netmask, instead
                   * of static netmask of 255.255.255.0 */
          	local_IP_addr = (remote_IP_addr & IP_netmask) +
                  	(~remote_IP_addr & ntohl(0x0003));
  
  	        if(!card->u.c.slarp_timer) {
  			IP_addr = local_IP_addr;
  			local_IP_addr = remote_IP_addr;
  			remote_IP_addr = IP_addr;
         		}
  	}
  
          fs = get_fs();                  /* Save file system  */
          set_fs(get_ds());               /* Get user space block */
  
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
          /* Setup a structure for adding/removing routes */
          memset(&if_info, 0, sizeof(if_info));
          strcpy(if_info.ifr_name, dev->name);
  
  #else
  	/* Setup a structure for adding/removing routes */
  	dev->pa_mask = IP_netmask;
  	dev->pa_dstaddr = remote_IP_addr;
  	dev->pa_addr = local_IP_addr;
  
  	memset(&route, 0, sizeof(route));
  	route.rt_dev = dev->name;
  	route.rt_flags = 0;
  	((struct sockaddr_in *)&(route.rt_dst))->sin_addr.s_addr =
  			dev->pa_dstaddr;
  	((struct sockaddr_in *)&(route.rt_dst))->sin_family = AF_INET;
  	((struct sockaddr_in *)&(route.rt_genmask))->sin_addr.s_addr =
  			0xFFFFFFFF;
          ((struct sockaddr_in *)&(route.rt_genmask))->sin_family =
  			AF_INET;
  #endif
  
  	switch (chdlc_priv_area->route_status) {
  
  	case ADD_ROUTE:
  
  		if(!card->u.c.slarp_timer) {
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  			if_data2 = (struct sockaddr_in *)&if_info.ifr_dstaddr;
  			if_data2->sin_addr.s_addr = remote_IP_addr;
  			if_data2->sin_family = AF_INET;
  			err = devinet_ioctl(SIOCSIFDSTADDR, &if_info);
  #else
                          err = ip_rt_new(&route);
  #endif
  		} else { 
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  			if_data1 = (struct sockaddr_in *)&if_info.ifr_addr;
  			if_data1->sin_addr.s_addr = local_IP_addr;
  			if_data1->sin_family = AF_INET;
  			if(!(err = devinet_ioctl(SIOCSIFADDR, &if_info))){
  				if_data2 = (struct sockaddr_in *)&if_info.ifr_dstaddr;
  				if_data2->sin_addr.s_addr = remote_IP_addr;
  				if_data2->sin_family = AF_INET;
  				err = devinet_ioctl(SIOCSIFDSTADDR, &if_info);
  			}
  #else
                 		err = ip_rt_new(&route);
  #endif
  		}
  
                 if(err) {
  			printk(KERN_INFO "%s: Add route %u.%u.%u.%u failed (%d)\n", 
  				card->devname, NIPQUAD(remote_IP_addr), err);
  		} else {
  			((chdlc_private_area_t *)dev->priv)->route_status = ROUTE_ADDED;
  			printk(KERN_INFO "%s: Dynamic route added.\n",
  				card->devname);
  			printk(KERN_INFO "%s:    Local IP addr : %u.%u.%u.%u\n",
  				card->devname, NIPQUAD(local_IP_addr));
  			printk(KERN_INFO "%s:    Remote IP addr: %u.%u.%u.%u\n",
  				card->devname, NIPQUAD(remote_IP_addr));
  			chdlc_priv_area->route_removed = 0;
  		}
  		break;
  
  
  	case REMOVE_ROUTE:
  	
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  		/* Change the local ip address of the interface to 0.
  		 * This will also delete the destination route.
  		 */
  		if(!card->u.c.slarp_timer) {
  			if_data2 = (struct sockaddr_in *)&if_info.ifr_dstaddr;
  			if_data2->sin_addr.s_addr = 0;
  			if_data2->sin_family = AF_INET;
  			err = devinet_ioctl(SIOCSIFDSTADDR, &if_info);
  		} else {
  			if_data1 = (struct sockaddr_in *)&if_info.ifr_addr;
  			if_data1->sin_addr.s_addr = 0;
  			if_data1->sin_family = AF_INET;
  			err = devinet_ioctl(SIOCSIFADDR,&if_info);
  		
  		}
  #else
  		/* set the point-to-point IP address to 0.0.0.0 */
  		dev->pa_dstaddr = 0; 
  		err = ip_rt_kill(&route);
  #endif
  		if(err) {
  			printk(KERN_INFO
  				"%s: Remove route %u.%u.%u.%u failed, (err %d)\n",
  					card->devname, NIPQUAD(remote_IP_addr),
  					err);
  		} else {
  			((chdlc_private_area_t *)dev->priv)->route_status =
  				NO_ROUTE;
                          printk(KERN_INFO "%s: Dynamic route removed: %u.%u.%u.%u\n",
                                          card->devname, NIPQUAD(local_IP_addr)); 
  			chdlc_priv_area->route_removed = 1;
  		}
  		break;
  	}
  
          set_fs(fs);                     /* Restore file system */
  
  }
  
  
  /*=============================================================================
   * Store a UDP management packet for later processing.
   */
  
  static int store_udp_mgmt_pkt(char udp_pkt_src, sdla_t* card,
                                  struct sk_buff *skb, netdevice_t* dev,
                                  chdlc_private_area_t* chdlc_priv_area )
  {
  	int udp_pkt_stored = 0;
  
  	if(!chdlc_priv_area->udp_pkt_lgth &&
  	  (skb->len <= MAX_LGTH_UDP_MGNT_PKT)) {
          	chdlc_priv_area->udp_pkt_lgth = skb->len;
  		chdlc_priv_area->udp_pkt_src = udp_pkt_src;
         		memcpy(chdlc_priv_area->udp_pkt_data, skb->data, skb->len);
  		chdlc_priv_area->timer_int_enabled = TMR_INT_ENABLED_UDP;
  		udp_pkt_stored = 1;
  	}
  
  	if(udp_pkt_src == UDP_PKT_FRM_STACK){
  		wan_dev_kfree_skb(skb, FREE_WRITE);
  	}else{
                  wan_dev_kfree_skb(skb, FREE_READ);
  	}
  		
  	return(udp_pkt_stored);
  }
  
  
  /*=============================================================================
   * Process UDP management packet.
   */
  
  static int process_udp_mgmt_pkt(sdla_t* card, netdevice_t* dev,
  				chdlc_private_area_t* chdlc_priv_area ) 
  {
  	unsigned char *buf;
  	unsigned int frames, len;
  	struct sk_buff *new_skb;
  	unsigned short buffer_length, real_len;
  	unsigned long data_ptr;
  	unsigned data_length;
  	int udp_mgmt_req_valid = 1;
  	CHDLC_MAILBOX_STRUCT *mb = card->mbox;
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  	chdlc_udp_pkt_t *chdlc_udp_pkt;
  	struct timeval tv;
  	int err;
  	char ut_char;
  
  	chdlc_udp_pkt = (chdlc_udp_pkt_t *) chdlc_priv_area->udp_pkt_data;
  
  	if(chdlc_priv_area->udp_pkt_src == UDP_PKT_FRM_NETWORK){
  
  		/* Only these commands are support for remote debugging.
  		 * All others are not */
  		switch(chdlc_udp_pkt->cblock.command) {
  
  			case READ_GLOBAL_STATISTICS:
  			case READ_MODEM_STATUS:  
  			case READ_CHDLC_LINK_STATUS:
  			case CPIPE_ROUTER_UP_TIME:
  			case READ_COMMS_ERROR_STATS:
  			case READ_CHDLC_OPERATIONAL_STATS:
  
  			/* These two commands are executed for
  			 * each request */
  			case READ_CHDLC_CONFIGURATION:
  			case READ_CHDLC_CODE_VERSION:
  				udp_mgmt_req_valid = 1;
  				break;
  			default:
  				udp_mgmt_req_valid = 0;
  				break;
  		} 
  	}
  	
    	if(!udp_mgmt_req_valid) {
  
  		/* set length to 0 */
  		chdlc_udp_pkt->cblock.buffer_length = 0;
  
      		/* set return code */
  		chdlc_udp_pkt->cblock.return_code = 0xCD;
  
  		if (net_ratelimit()){	
  			printk(KERN_INFO 
  			"%s: Warning, Illegal UDP command attempted from network: %x\n",
  			card->devname,chdlc_udp_pkt->cblock.command);
  		}
  
     	} else {
  	   	unsigned long trace_status_cfg_addr = 0;
  		TRACE_STATUS_EL_CFG_STRUCT trace_cfg_struct;
  		TRACE_STATUS_ELEMENT_STRUCT trace_element_struct;
  
  		switch(chdlc_udp_pkt->cblock.command) {
  
  		case CPIPE_ENABLE_TRACING:
  		     if (!chdlc_priv_area->TracingEnabled) {
  
  			/* OPERATE_DATALINE_MONITOR */
  
  			mb->buffer_length = sizeof(LINE_TRACE_CONFIG_STRUCT);
  			mb->command = SET_TRACE_CONFIGURATION;
  
      			((LINE_TRACE_CONFIG_STRUCT *)mb->data)->
  				trace_config = TRACE_ACTIVE;
  			/* Trace delay mode is not used because it slows
  			   down transfer and results in a standoff situation
  			   when there is a lot of data */
  
  			/* Configure the Trace based on user inputs */
  			((LINE_TRACE_CONFIG_STRUCT *)mb->data)->trace_config |= 
  					chdlc_udp_pkt->data[0];
  
  			((LINE_TRACE_CONFIG_STRUCT *)mb->data)->
  			   trace_deactivation_timer = 4000;
  
  
  			err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  			if (err != COMMAND_OK) {
  				chdlc_error(card,err,mb);
  				card->TracingEnabled = 0;
  				chdlc_udp_pkt->cblock.return_code = err;
  				mb->buffer_length = 0;
  				break;
  	    		} 
  
  			/* Get the base address of the trace element list */
  			mb->buffer_length = 0;
  			mb->command = READ_TRACE_CONFIGURATION;
  			err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  
  			if (err != COMMAND_OK) {
  				chdlc_error(card,err,mb);
  				chdlc_priv_area->TracingEnabled = 0;
  				chdlc_udp_pkt->cblock.return_code = err;
  				mb->buffer_length = 0;
  				break;
  	    		} 	
  
  	   		trace_status_cfg_addr =((LINE_TRACE_CONFIG_STRUCT *)
  				mb->data) -> ptr_trace_stat_el_cfg_struct;
  
  			sdla_peek(&card->hw, trace_status_cfg_addr,
  				 &trace_cfg_struct, sizeof(trace_cfg_struct));
  		    
  			chdlc_priv_area->start_trace_addr = trace_cfg_struct.
  				base_addr_trace_status_elements;
  
  			chdlc_priv_area->number_trace_elements = 
  					trace_cfg_struct.number_trace_status_elements;
  
  			chdlc_priv_area->end_trace_addr = (unsigned long)
  					((TRACE_STATUS_ELEMENT_STRUCT *)
  					 chdlc_priv_area->start_trace_addr + 
  					 (chdlc_priv_area->number_trace_elements - 1));
  
  			chdlc_priv_area->base_addr_trace_buffer = 
  					trace_cfg_struct.base_addr_trace_buffer;
  
  			chdlc_priv_area->end_addr_trace_buffer = 
  					trace_cfg_struct.end_addr_trace_buffer;
  
  		    	chdlc_priv_area->curr_trace_addr = 
  					trace_cfg_struct.next_trace_element_to_use;
  
  	    		chdlc_priv_area->available_buffer_space = 2000 - 
  								  sizeof(ip_pkt_t) -
  								  sizeof(udp_pkt_t) -
  							      	  sizeof(wp_mgmt_t) -
  								  sizeof(cblock_t) -
  							          sizeof(trace_info_t);	
  	       	     }
  		     chdlc_udp_pkt->cblock.return_code = COMMAND_OK;
  		     mb->buffer_length = 0;
  	       	     chdlc_priv_area->TracingEnabled = 1;
  	       	     break;
  	   
  
  		case CPIPE_DISABLE_TRACING:
  		     if (chdlc_priv_area->TracingEnabled) {
  
  			/* OPERATE_DATALINE_MONITOR */
  			mb->buffer_length = sizeof(LINE_TRACE_CONFIG_STRUCT);
  			mb->command = SET_TRACE_CONFIGURATION;
      			((LINE_TRACE_CONFIG_STRUCT *)mb->data)->
  				trace_config = TRACE_INACTIVE;
  			err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  		     }		
  
  		     chdlc_priv_area->TracingEnabled = 0;
  		     chdlc_udp_pkt->cblock.return_code = COMMAND_OK;
  		     mb->buffer_length = 0;
  		     break;
  	   
  
  		case CPIPE_GET_TRACE_INFO:
  
  		     if (!chdlc_priv_area->TracingEnabled) {
  			chdlc_udp_pkt->cblock.return_code = 1;
  			mb->buffer_length = 0;
  			break;
  		     }
  
    		     chdlc_udp_pkt->trace_info.ismoredata = 0x00;
  		     buffer_length = 0;	/* offset of packet already occupied */
  
  		     for (frames=0; frames < chdlc_priv_area->number_trace_elements; frames++){
  
  			trace_pkt_t *trace_pkt = (trace_pkt_t *)
  				&chdlc_udp_pkt->data[buffer_length];
  
  			sdla_peek(&card->hw, chdlc_priv_area->curr_trace_addr,
  			   	  (unsigned char *)&trace_element_struct,
  			   	  sizeof(TRACE_STATUS_ELEMENT_STRUCT));
  
       			if (trace_element_struct.opp_flag == 0x00) {
  			 	break;
  			}
  
  			/* get pointer to real data */
  			data_ptr = trace_element_struct.ptr_data_bfr;
  
  			/* See if there is actual data on the trace buffer */
  			if (data_ptr){
  				data_length = trace_element_struct.trace_length;
  			}else{
  				data_length = 0;
  				chdlc_udp_pkt->trace_info.ismoredata = 0x01;
  			}
  	
     			if( (chdlc_priv_area->available_buffer_space - buffer_length)
  				< ( sizeof(trace_pkt_t) + data_length) ) {
  
                              /* indicate there are more frames on board & exit */
  				chdlc_udp_pkt->trace_info.ismoredata = 0x01;
                                 	break;
                           }
  
  			trace_pkt->status = trace_element_struct.trace_type;
  
  			trace_pkt->time_stamp =
  				trace_element_struct.trace_time_stamp;
  
  			trace_pkt->real_length =
  				trace_element_struct.trace_length;
  
  			/* see if we can fit the frame into the user buffer */
  			real_len = trace_pkt->real_length;
  
  			if (data_ptr == 0) {
  			     	trace_pkt->data_avail = 0x00;
  			} else {
  				unsigned tmp = 0;
  
  				/* get the data from circular buffer
  				    must check for end of buffer */
  			        trace_pkt->data_avail = 0x01;
  
  				if ((data_ptr + real_len) >
  					     chdlc_priv_area->end_addr_trace_buffer + 1){
  
  				    	tmp = chdlc_priv_area->end_addr_trace_buffer - data_ptr + 1;
  				    	sdla_peek(&card->hw, data_ptr,
  					       	  trace_pkt->data,tmp);
  				    	data_ptr = chdlc_priv_area->base_addr_trace_buffer;
  				}
  	
  		        	sdla_peek(&card->hw, data_ptr,
  					  &trace_pkt->data[tmp], real_len - tmp);
  			}	
  
  			/* zero the opp flag to show we got the frame */
  			ut_char = 0x00;
  			sdla_poke(&card->hw, chdlc_priv_area->curr_trace_addr, &ut_char, 1);
  
         			/* now move onto the next frame */
         			chdlc_priv_area->curr_trace_addr += sizeof(TRACE_STATUS_ELEMENT_STRUCT);
  
         			/* check if we went over the last address */
  			if ( chdlc_priv_area->curr_trace_addr > chdlc_priv_area->end_trace_addr ) {
  				chdlc_priv_area->curr_trace_addr = chdlc_priv_area->start_trace_addr;
         			}
  
              		if(trace_pkt->data_avail == 0x01) {
  				buffer_length += real_len - 1;
  			}
  	 
  	       	    	/* for the header */
  	            	buffer_length += sizeof(trace_pkt_t);
  
  		     }  /* For Loop */
  
  		     if (frames == chdlc_priv_area->number_trace_elements){
  			chdlc_udp_pkt->trace_info.ismoredata = 0x01;
  	             }
   		     chdlc_udp_pkt->trace_info.num_frames = frames;
  		 
      		     mb->buffer_length = buffer_length;
  		     chdlc_udp_pkt->cblock.buffer_length = buffer_length; 
  		 
  		     chdlc_udp_pkt->cblock.return_code = COMMAND_OK; 
  		     
  		     break;
  
  
  		case CPIPE_FT1_READ_STATUS:
  			((unsigned char *)chdlc_udp_pkt->data )[0] =
  				flags->FT1_info_struct.parallel_port_A_input;
  
  			((unsigned char *)chdlc_udp_pkt->data )[1] =
  				flags->FT1_info_struct.parallel_port_B_input;
  				
  			chdlc_udp_pkt->cblock.return_code = COMMAND_OK;
  			chdlc_udp_pkt->cblock.buffer_length = 2;
  			mb->buffer_length = 2;
  			break;
  
  		case CPIPE_ROUTER_UP_TIME:
  			do_gettimeofday( &tv );
  			chdlc_priv_area->router_up_time = tv.tv_sec - 
  					chdlc_priv_area->router_start_time;
  			*(unsigned long *)&chdlc_udp_pkt->data = 
  					chdlc_priv_area->router_up_time;	
  			mb->buffer_length = sizeof(unsigned long);
  			chdlc_udp_pkt->cblock.buffer_length = sizeof(unsigned long);
  			chdlc_udp_pkt->cblock.return_code = COMMAND_OK;
  			break;
  
     		case FT1_MONITOR_STATUS_CTRL:
  			/* Enable FT1 MONITOR STATUS */
  	        	if ((chdlc_udp_pkt->data[0] & ENABLE_READ_FT1_STATUS) ||  
  				(chdlc_udp_pkt->data[0] & ENABLE_READ_FT1_OP_STATS)) {
  			
  			     	if( rCount++ != 0 ) {
  					chdlc_udp_pkt->cblock.
  					return_code = COMMAND_OK;
  					mb->buffer_length = 1;
  		  			break;
  		    	     	}
  	      		}
  
  	      		/* Disable FT1 MONITOR STATUS */
  	      		if( chdlc_udp_pkt->data[0] == 0) {
  
  	      	   	     	if( --rCount != 0) {
  		  			chdlc_udp_pkt->cblock.
  					return_code = COMMAND_OK;
  					mb->buffer_length = 1;
  		  			break;
  	   	    	     	} 
  	      		} 	
  			goto dflt_1;
  
  		default:
  dflt_1:
  			/* it's a board command */
  			mb->command = chdlc_udp_pkt->cblock.command;
  			mb->buffer_length = chdlc_udp_pkt->cblock.buffer_length;
  			if (mb->buffer_length) {
  				memcpy(&mb->data, (unsigned char *) chdlc_udp_pkt->
  							data, mb->buffer_length);
  	      		} 
  			/* run the command on the board */
  			err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  			if (err != COMMAND_OK) {
  				break;
  			}
  
  			/* copy the result back to our buffer */
  	         	memcpy(&chdlc_udp_pkt->cblock, mb, sizeof(cblock_t)); 
  			
  			if (mb->buffer_length) {
  	         		memcpy(&chdlc_udp_pkt->data, &mb->data, 
  								mb->buffer_length); 
  	      		}
  
  		} /* end of switch */
       	} /* end of else */
  
       	/* Fill UDP TTL */
  	chdlc_udp_pkt->ip_pkt.ttl = card->wandev.ttl; 
  
       	len = reply_udp(chdlc_priv_area->udp_pkt_data, mb->buffer_length);
  	
  
       	if(chdlc_priv_area->udp_pkt_src == UDP_PKT_FRM_NETWORK){
  
  		/* Must check if we interrupted if_send() routine. The
  		 * tx buffers might be used. If so drop the packet */
  	   	if (!test_bit(SEND_CRIT,&card->wandev.critical)) {
  		
  			if(!chdlc_send(card, chdlc_priv_area->udp_pkt_data, len)) {
  				++ card->wandev.stats.tx_packets;
  #if defined(LINUX_2_1) || defined(LINUX_2_4)
  				card->wandev.stats.tx_bytes += len;
  #endif
  			}
  		}
  	} else {	
  	
  		/* Pass it up the stack
      		   Allocate socket buffer */
  		if ((new_skb = dev_alloc_skb(len)) != NULL) {
  			/* copy data into new_skb */
  
   	    		buf = skb_put(new_skb, len);
    	    		memcpy(buf, chdlc_priv_area->udp_pkt_data, len);
  
              		/* Decapsulate pkt and pass it up the protocol stack */
  	    		new_skb->protocol = htons(ETH_P_IP);
              		new_skb->dev = dev;
  	    		new_skb->mac.raw  = new_skb->data;
  	
  			netif_rx(new_skb);
  		} else {
  	    	
  			printk(KERN_INFO "%s: no socket buffers available!\n",
  					card->devname);
    		}
      	}
   
  	chdlc_priv_area->udp_pkt_lgth = 0;
   	
  	return 0;
  }
  
  /*============================================================================
   * Initialize Receive and Transmit Buffers.
   */
  
  static void init_chdlc_tx_rx_buff( sdla_t* card)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	CHDLC_TX_STATUS_EL_CFG_STRUCT *tx_config;
  	CHDLC_RX_STATUS_EL_CFG_STRUCT *rx_config;
  	char err;
  	
  	mb->buffer_length = 0;
  	mb->command = READ_CHDLC_CONFIGURATION;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  
  	if(err != COMMAND_OK) {
  		if (card->wandev.dev){
  			chdlc_error(card,err,mb);
  		}
  		return;
  	}
  
  	if(card->hw.type == SDLA_S514) {
  		tx_config = (CHDLC_TX_STATUS_EL_CFG_STRUCT *)(card->hw.dpmbase +
                  (((CHDLC_CONFIGURATION_STRUCT *)mb->data)->
                              ptr_CHDLC_Tx_stat_el_cfg_struct));
          	rx_config = (CHDLC_RX_STATUS_EL_CFG_STRUCT *)(card->hw.dpmbase +
                  (((CHDLC_CONFIGURATION_STRUCT *)mb->data)->
                              ptr_CHDLC_Rx_stat_el_cfg_struct));
  
         		/* Setup Head and Tails for buffers */
          	card->u.c.txbuf_base = (void *)(card->hw.dpmbase +
                  tx_config->base_addr_Tx_status_elements);
          	card->u.c.txbuf_last = 
  		(CHDLC_DATA_TX_STATUS_EL_STRUCT *)  
                  card->u.c.txbuf_base +
  		(tx_config->number_Tx_status_elements - 1);
  
          	card->u.c.rxbuf_base = (void *)(card->hw.dpmbase +
                  rx_config->base_addr_Rx_status_elements);
          	card->u.c.rxbuf_last =
  		(CHDLC_DATA_RX_STATUS_EL_STRUCT *)
                  card->u.c.rxbuf_base +
  		(rx_config->number_Rx_status_elements - 1);
  
   		/* Set up next pointer to be used */
          	card->u.c.txbuf = (void *)(card->hw.dpmbase +
                  tx_config->next_Tx_status_element_to_use);
          	card->u.c.rxmb = (void *)(card->hw.dpmbase +
                  rx_config->next_Rx_status_element_to_use);
  	}
          else {
                  tx_config = (CHDLC_TX_STATUS_EL_CFG_STRUCT *)(card->hw.dpmbase +
  			(((CHDLC_CONFIGURATION_STRUCT *)mb->data)->
  			ptr_CHDLC_Tx_stat_el_cfg_struct % SDLA_WINDOWSIZE));
  
                  rx_config = (CHDLC_RX_STATUS_EL_CFG_STRUCT *)(card->hw.dpmbase +
  			(((CHDLC_CONFIGURATION_STRUCT *)mb->data)->
  			ptr_CHDLC_Rx_stat_el_cfg_struct % SDLA_WINDOWSIZE));
  
                  /* Setup Head and Tails for buffers */
                  card->u.c.txbuf_base = (void *)(card->hw.dpmbase +
  		(tx_config->base_addr_Tx_status_elements % SDLA_WINDOWSIZE));
                  card->u.c.txbuf_last =
  		(CHDLC_DATA_TX_STATUS_EL_STRUCT *)card->u.c.txbuf_base
  		+ (tx_config->number_Tx_status_elements - 1);
                  card->u.c.rxbuf_base = (void *)(card->hw.dpmbase +
  		(rx_config->base_addr_Rx_status_elements % SDLA_WINDOWSIZE));
                  card->u.c.rxbuf_last = 
  		(CHDLC_DATA_RX_STATUS_EL_STRUCT *)card->u.c.rxbuf_base
  		+ (rx_config->number_Rx_status_elements - 1);
  
                   /* Set up next pointer to be used */
                  card->u.c.txbuf = (void *)(card->hw.dpmbase +
  		(tx_config->next_Tx_status_element_to_use % SDLA_WINDOWSIZE));
                  card->u.c.rxmb = (void *)(card->hw.dpmbase +
  		(rx_config->next_Rx_status_element_to_use % SDLA_WINDOWSIZE));
          }
  
          /* Setup Actual Buffer Start and end addresses */
          card->u.c.rx_base = rx_config->base_addr_Rx_buffer;
          card->u.c.rx_top  = rx_config->end_addr_Rx_buffer;
  
  }
  
  /*=============================================================================
   * Perform Interrupt Test by running READ_CHDLC_CODE_VERSION command MAX_INTR
   * _TEST_COUNTER times.
   */
  static int intr_test( sdla_t* card)
  {
  	CHDLC_MAILBOX_STRUCT* mb = card->mbox;
  	int err,i;
  
  	Intr_test_counter = 0;
  	
  	err = chdlc_set_intr_mode(card, APP_INT_ON_COMMAND_COMPLETE);
  
  	if (err == CMD_OK) { 
  		for (i = 0; i < MAX_INTR_TEST_COUNTER; i ++) {	
  			mb->buffer_length  = 0;
  			mb->command = READ_CHDLC_CODE_VERSION;
  			err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  			if (err != CMD_OK) 
  				chdlc_error(card, err, mb);
  		}
  	}
  	else {
  		return err;
  	}
  
  	err = chdlc_set_intr_mode(card, 0);
  
  	if (err != CMD_OK)
  		return err;
  
  	return 0;
  }
  
  /*==============================================================================
   * Determine what type of UDP call it is. CPIPEAB ?
   */
  static int udp_pkt_type(struct sk_buff *skb, sdla_t* card)
  {
  	 chdlc_udp_pkt_t *chdlc_udp_pkt = (chdlc_udp_pkt_t *)skb->data;
  
  #ifdef _WAN_UDP_DEBUG
  		printk(KERN_INFO "SIG %s = %s\n\
  				  UPP %x = %x\n\
  				  PRT %x = %x\n\
  				  REQ %i = %i\n\
  				  36 th = %x 37th = %x\n",
  				  chdlc_udp_pkt->wp_mgmt.signature,
  				  UDPMGMT_SIGNATURE,
  				  chdlc_udp_pkt->udp_pkt.udp_dst_port,
  				  ntohs(card->wandev.udp_port),
  				  chdlc_udp_pkt->ip_pkt.protocol,
  				  UDPMGMT_UDP_PROTOCOL,
  				  chdlc_udp_pkt->wp_mgmt.request_reply,
  				  UDPMGMT_REQUEST,
  				  skb->data[36], skb->data[37]);
  #endif	
  		
  	if (!strncmp(chdlc_udp_pkt->wp_mgmt.signature,UDPMGMT_SIGNATURE,8) &&
  	   (chdlc_udp_pkt->udp_pkt.udp_dst_port == ntohs(card->wandev.udp_port)) &&
  	   (chdlc_udp_pkt->ip_pkt.protocol == UDPMGMT_UDP_PROTOCOL) &&
  	   (chdlc_udp_pkt->wp_mgmt.request_reply == UDPMGMT_REQUEST)) {
  
  		return UDP_CPIPE_TYPE;
  
  	}else{ 
  		return UDP_INVALID_TYPE;
  	}
  }
  
  /*============================================================================
   * Set PORT state.
   */
  static void port_set_state (sdla_t *card, int state)
  {
          if (card->u.c.state != state)
          {
                  switch (state)
                  {
                  case WAN_CONNECTED:
                          printk (KERN_INFO "%s: Link connected!\n",
                                  card->devname);
                        	break;
  
                  case WAN_CONNECTING:
                          printk (KERN_INFO "%s: Link connecting...\n",
                                  card->devname);
                          break;
  
                  case WAN_DISCONNECTED:
                          printk (KERN_INFO "%s: Link disconnected!\n",
                                  card->devname);
                          break;
                  }
  
                  card->wandev.state = card->u.c.state = state;
  		if (card->wandev.dev){
  			netdevice_t *dev = card->wandev.dev;
  			chdlc_private_area_t *chdlc_priv_area = dev->priv;
  			chdlc_priv_area->common.state = state;
  		}
          }
  }
  
  /*===========================================================================
   * config_chdlc
   *
   *	Configure the chdlc protocol and enable communications.		
   *
   *   	The if_open() function binds this function to the poll routine.
   *      Therefore, this function will run every time the chdlc interface
   *      is brought up. We cannot run this function from the if_open 
   *      because if_open does not have access to the remote IP address.
   *      
   *	If the communications are not enabled, proceed to configure
   *      the card and enable communications.
   *
   *      If the communications are enabled, it means that the interface
   *      was shutdown by ether the user or driver. In this case, we 
   *      have to check that the IP addresses have not changed.  If
   *      the IP addresses have changed, we have to reconfigure the firmware
   *      and update the changed IP addresses.  Otherwise, just exit.
   *
   */
  
  static int config_chdlc (sdla_t *card)
  {
  	netdevice_t *dev = card->wandev.dev;
  	chdlc_private_area_t *chdlc_priv_area = dev->priv;
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  
  	if (card->u.c.comm_enabled){
  
  		/* Jun 20. 2000: NC
  		 * IP addresses are not used in the API mode */
  		
  		if ((chdlc_priv_area->ip_local_tmp != chdlc_priv_area->ip_local ||
  		     chdlc_priv_area->ip_remote_tmp != chdlc_priv_area->ip_remote) && 
  		     card->u.c.usedby == WANPIPE) {
  			
  			/* The IP addersses have changed, we must
                           * stop the communications and reconfigure
                           * the card. Reason: the firmware must know
                           * the local and remote IP addresses. */
  			disable_comm(card);
  			port_set_state(card, WAN_DISCONNECTED);
  			printk(KERN_INFO 
  				"%s: IP addresses changed!\n",
  					card->devname);
  			printk(KERN_INFO 
  				"%s: Restarting communications ...\n",
  					card->devname);
  		}else{ 
  			/* IP addresses are the same and the link is up, 
                           * we dont have to do anything here. Therefore, exit */
  			return 0;
  		}
  	}
  
  	chdlc_priv_area->ip_local = chdlc_priv_area->ip_local_tmp;
  	chdlc_priv_area->ip_remote = chdlc_priv_area->ip_remote_tmp;
  
  
  	/* Setup the Board for asynchronous mode */
  	if (card->u.c.async_mode){
  		
  		if (set_asy_config(card)) {
  			printk (KERN_INFO "%s: Failed CHDLC Async configuration!\n",
  				card->devname);
  			return 0;
  		}
  	}else{
  		/* Setup the Board for CHDLC */
  		if (set_chdlc_config(card)) {
  			printk (KERN_INFO "%s: Failed CHDLC configuration!\n",
  				card->devname);
  			return 0;
  		}
  	}
  
  	/* Set interrupt mode and mask */
          if (chdlc_set_intr_mode(card, APP_INT_ON_RX_FRAME |
                  		APP_INT_ON_GLOBAL_EXCEP_COND |
                  		APP_INT_ON_TX_FRAME |
                  		APP_INT_ON_CHDLC_EXCEP_COND | APP_INT_ON_TIMER)){
  		printk (KERN_INFO "%s: Failed to set interrupt triggers!\n",
  				card->devname);
  		return 0;	
          }
  	
  
  	/* Mask the Transmit and Timer interrupt */
  	flags->interrupt_info_struct.interrupt_permission &= 
  		~(APP_INT_ON_TX_FRAME | APP_INT_ON_TIMER);
  
  	/* In TTY mode, receive interrupt will be enabled during
  	 * wanpipe_tty_open() operation */
  	if (card->tty_opt){
  		flags->interrupt_info_struct.interrupt_permission &= ~APP_INT_ON_RX_FRAME;
  	}
  
  	/* Enable communications */
   	if (card->u.c.async_mode){
  		if (asy_comm_enable(card) != 0) {
  			printk(KERN_INFO "%s: Failed to enable async commnunication!\n",
  					card->devname);
  			flags->interrupt_info_struct.interrupt_permission = 0;
  			card->u.c.comm_enabled=0;
  			chdlc_set_intr_mode(card,0);
  			return 0;
  		}
          }else{ 
  		if (chdlc_comm_enable(card) != 0) {
  			printk(KERN_INFO "%s: Failed to enable chdlc communications!\n",
  					card->devname);
  			flags->interrupt_info_struct.interrupt_permission = 0;
  			card->u.c.comm_enabled=0;
  			chdlc_set_intr_mode(card,0);
  			return 0;
  		}
  	}
  
  	/* Initialize Rx/Tx buffer control fields */
  	init_chdlc_tx_rx_buff(card);
  	port_set_state(card, WAN_CONNECTING);
  	return 0; 
  }
  
  
  /*============================================================
   * chdlc_poll
   *	
   * Rationale:
   * 	We cannot manipulate the routing tables, or
   *      ip addresses withing the interrupt. Therefore
   *      we must perform such actons outside an interrupt 
   *      at a later time. 
   *
   * Description:	
   *	CHDLC polling routine, responsible for 
   *     	shutting down interfaces upon disconnect
   *     	and adding/removing routes. 
   *      
   * Usage:        
   * 	This function is executed for each CHDLC  
   * 	interface through a tq_schedule bottom half.
   *      
   *      trigger_chdlc_poll() function is used to kick
   *      the chldc_poll routine.  
   */
  
  static void chdlc_poll (netdevice_t *dev)
  {
  	chdlc_private_area_t *chdlc_priv_area;
  	sdla_t *card;
  	u8 check_gateway=0;	
  	SHARED_MEMORY_INFO_STRUCT* flags;
  
  	
  	if (!dev || (chdlc_priv_area=dev->priv) == NULL)
  		return;
  
  	card = chdlc_priv_area->card;
  	flags = card->u.c.flags;
  	
  	/* (Re)Configuraiton is in progress, stop what you are 
  	 * doing and get out */
  	if (test_bit(PERI_CRIT,&card->wandev.critical)){
  		clear_bit(POLL_CRIT,&card->wandev.critical);
  		return;
  	}
  	
  	/* if_open() function has triggered the polling routine
  	 * to determine the configured IP addresses.  Once the
  	 * addresses are found, trigger the chdlc configuration */
  	if (test_bit(0,&chdlc_priv_area->config_chdlc)){
  
  		chdlc_priv_area->ip_local_tmp  = get_ip_address(dev,WAN_LOCAL_IP);
  		chdlc_priv_area->ip_remote_tmp = get_ip_address(dev,WAN_POINTOPOINT_IP);
  	
  	       /* Jun 20. 2000 Bug Fix
  	 	* Only perform this check in WANPIPE mode, since
  	 	* IP addresses are not used in the API mode. */
  	
  		if (chdlc_priv_area->ip_local_tmp == chdlc_priv_area->ip_remote_tmp && 
  		    card->u.c.slarp_timer == 0x00 && 
  		    !card->u.c.backup && 
  		    card->u.c.usedby == WANPIPE){
  
  			if (++chdlc_priv_area->ip_error > MAX_IP_ERRORS){
  				printk(KERN_INFO "\n%s: --- WARNING ---\n",
  						card->devname);
  				printk(KERN_INFO 
  				"%s: The local IP address is the same as the\n",
  						card->devname);
  				printk(KERN_INFO 
  				"%s: Point-to-Point IP address.\n",
  						card->devname);
  				printk(KERN_INFO "%s: --- WARNING ---\n\n",
  						card->devname);
  			}else{
  				clear_bit(POLL_CRIT,&card->wandev.critical);
  				chdlc_priv_area->poll_delay_timer.expires = jiffies+HZ;
  				add_timer(&chdlc_priv_area->poll_delay_timer);
  				return;
  			}
  		}
  
  		clear_bit(0,&chdlc_priv_area->config_chdlc);
  		clear_bit(POLL_CRIT,&card->wandev.critical);
  		
  		chdlc_priv_area->timer_int_enabled |= TMR_INT_ENABLED_CONFIG;
  		flags->interrupt_info_struct.interrupt_permission |= APP_INT_ON_TIMER;
  		return;
  	}
  	/* Dynamic interface implementation, as well as dynamic
  	 * routing.  */
  	
  	switch (card->u.c.state){
  
  	case WAN_DISCONNECTED:
  
  		/* If the dynamic interface configuration is on, and interface 
  		 * is up, then bring down the netowrk interface */
  		
  		if (test_bit(DYN_OPT_ON,&chdlc_priv_area->interface_down) && 
  		    !test_bit(DEV_DOWN,  &chdlc_priv_area->interface_down) &&		
  		    card->wandev.dev->flags & IFF_UP){	
  
  			printk(KERN_INFO "%s: Interface %s down.\n",
  				card->devname,card->wandev.dev->name);
  			change_dev_flags(card->wandev.dev,(card->wandev.dev->flags&~IFF_UP));
  			set_bit(DEV_DOWN,&chdlc_priv_area->interface_down);
  			chdlc_priv_area->route_status = NO_ROUTE;
  
  		}else{
  			/* We need to check if the local IP address is
                 	  	 * zero. If it is, we shouldn't try to remove it.
                   	 */
  
  			if (card->wandev.dev->flags & IFF_UP && 
  		    	    get_ip_address(card->wandev.dev,WAN_LOCAL_IP) && 
  		    	    chdlc_priv_area->route_status != NO_ROUTE &&
  			    card->u.c.slarp_timer){
  
  				process_route(card);
  			}
  		}
  		break;
  
  	case WAN_CONNECTED:
  
  		/* In SMP machine this code can execute before the interface
  		 * comes up.  In this case, we must make sure that we do not
  		 * try to bring up the interface before dev_open() is finished */
  
  
  		/* DEV_DOWN will be set only when we bring down the interface
  		 * for the very first time. This way we know that it was us
  		 * that brought the interface down */
  		
  		if (test_bit(DYN_OPT_ON,&chdlc_priv_area->interface_down) &&
  		    test_bit(DEV_DOWN,  &chdlc_priv_area->interface_down) &&
  		    !(card->wandev.dev->flags & IFF_UP)){
  			
  			printk(KERN_INFO "%s: Interface %s up.\n",
  				card->devname,card->wandev.dev->name);
  			change_dev_flags(card->wandev.dev,(card->wandev.dev->flags|IFF_UP));
  			clear_bit(DEV_DOWN,&chdlc_priv_area->interface_down);
  			check_gateway=1;
  		}
  
  		if (chdlc_priv_area->route_status == ADD_ROUTE && 
  		    card->u.c.slarp_timer){ 
  
  			process_route(card);
  			check_gateway=1;
  		}
  
  		if (chdlc_priv_area->gateway && check_gateway)
  			add_gateway(card,dev);
  
  		break;
  	}	
  
  	clear_bit(POLL_CRIT,&card->wandev.critical);
  }
  
  /*============================================================
   * trigger_chdlc_poll
   *
   * Description:
   * 	Add a chdlc_poll() task into a tq_scheduler bh handler
   *      for a specific dlci/interface.  This will kick
   *      the fr_poll() routine at a later time. 
   *
   * Usage:
   * 	Interrupts use this to defer a taks to 
   *      a polling routine.
   *
   */	
  static void trigger_chdlc_poll (netdevice_t *dev)
  {
  	chdlc_private_area_t *chdlc_priv_area;
  	sdla_t *card;
  
  	if (!dev)
  		return;
  	
  	if ((chdlc_priv_area = dev->priv)==NULL)
  		return;
  
  	card = chdlc_priv_area->card;
  	
  	if (test_and_set_bit(POLL_CRIT,&card->wandev.critical)){
  		return;
  	}
  	if (test_bit(PERI_CRIT,&card->wandev.critical)){
  		return; 
  	}
  #ifdef LINUX_2_4
  	schedule_task(&chdlc_priv_area->poll_task);
  #else
  	queue_task(&chdlc_priv_area->poll_task, &tq_scheduler);
  #endif
  	return;
  }
  
  
  static void chdlc_poll_delay (unsigned long dev_ptr)
  {
  	netdevice_t *dev = (netdevice_t *)dev_ptr;
  	trigger_chdlc_poll(dev);
  }
  
  
  void s508_lock (sdla_t *card, unsigned long *smp_flags)
  {
  #if defined(__SMP__) || defined(LINUX_2_4)
  	spin_lock_irqsave(&card->wandev.lock, *smp_flags);
          if (card->next){
          	spin_lock(&card->next->wandev.lock);
  	}
  #else
          disable_irq(card->hw.irq);
  #endif                                                                     
  }
  
  void s508_unlock (sdla_t *card, unsigned long *smp_flags)
  {
  #if defined(__SMP__) || defined(LINUX_2_4)
          if (card->next){
          	spin_unlock(&card->next->wandev.lock);
          }
          spin_unlock_irqrestore(&card->wandev.lock, *smp_flags);
  #else
          enable_irq(card->hw.irq);
  #endif           
  }
  
  //*********** TTY SECTION ****************
  #if defined(LINUX_2_4) || defined(LINUX_2_1)
  
  static void wanpipe_tty_trigger_tx_irq(sdla_t *card)
  {
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  	INTERRUPT_INFORMATION_STRUCT *chdlc_int = &flags->interrupt_info_struct;
  	chdlc_int->interrupt_permission |= APP_INT_ON_TX_FRAME;
  }
  
  static void wanpipe_tty_trigger_poll(sdla_t *card)
  {
  #ifdef LINUX_2_4
  	schedule_task(&card->tty_task_queue);
  #else
  	queue_task(&card->tty_task_queue, &tq_scheduler);
  #endif
  }
  
  static void tty_poll_task (void* data)
  {
  	sdla_t *card = (sdla_t*)data;
  	struct tty_struct *tty;
  
  	if ((tty=card->tty)==NULL)
  		return;
  	
  	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
  	    tty->ldisc.write_wakeup){
  		(tty->ldisc.write_wakeup)(tty);
  	}
  	wake_up_interruptible(&tty->write_wait);
  #if defined(SERIAL_HAVE_POLL_WAIT) || \
           (defined LINUX_2_1 && LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15))
  	wake_up_interruptible(&tty->poll_wait);
  #endif	
  	return;
  }
  
  static void wanpipe_tty_close(struct tty_struct *tty, struct file * filp)
  {
  	sdla_t *card;
  	unsigned long smp_flags;
  	
  	if (!tty || !tty->driver_data){
  		return;
  	}
  	
  	card = (sdla_t*)tty->driver_data;
  	
  	if (!card)
  		return;
  
  	printk(KERN_INFO "%s: Closing TTY Driver!\n",
  			card->devname);
  
  	/* Sanity Check */
  	if (!card->tty_open)
  		return;
  	
  	wanpipe_close(card);
  	if (--card->tty_open == 0){
  
  		lock_adapter_irq(&card->wandev.lock,&smp_flags);	
  		card->tty=NULL;
  		chdlc_disable_comm_shutdown(card);
  		unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  
  		if (card->tty_buf){
  			kfree(card->tty_buf);
  			card->tty_buf=NULL;			
  		}
  
  		if (card->tty_rx){
  			kfree(card->tty_rx);
  			card->tty_rx=NULL;
  		}
  	}
  	return;
  }
  static int wanpipe_tty_open(struct tty_struct *tty, struct file * filp)
  {
  	unsigned long smp_flags;
  	sdla_t *card;
  	
  	if (!tty){
  		return -ENODEV;
  	}
  	
  	if (!tty->driver_data){
  		int port;
  		port = MINOR(tty->device) - tty->driver.minor_start;
  		if ((port < 0) || (port >= NR_PORTS)) 
  			return -ENODEV;
  		
  		tty->driver_data = WAN_CARD(port);
  		if (!tty->driver_data)
  			return -ENODEV;
  	}
  
  	card = (sdla_t*)tty->driver_data;
  
  	if (!card){
  		lock_adapter_irq(&card->wandev.lock,&smp_flags);	
  		card->tty=NULL;
  		unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  		return -ENODEV;
  	}
  
  	printk(KERN_INFO "%s: Opening TTY Driver!\n",
  			card->devname);
  
  	if (card->tty_open == 0){
  		lock_adapter_irq(&card->wandev.lock,&smp_flags);	
  		card->tty=tty;
  		unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  
  		if (!card->tty_buf){
  			card->tty_buf = kmalloc(TTY_CHDLC_MAX_MTU, GFP_KERNEL);
  			if (!card->tty_buf){
  				card->tty_buf=NULL;
  				card->tty=NULL;
  				return -ENOMEM;	
  			}
  		}
  
  		if (!card->tty_rx){
  			card->tty_rx = kmalloc(TTY_CHDLC_MAX_MTU, GFP_KERNEL);
  			if (!card->tty_rx){
  				/* Free the buffer above */
  				kfree(card->tty_buf);
  				card->tty_buf=NULL;
  				card->tty=NULL;
  				return -ENOMEM;	
  			}
  		}
  	}
  
  	++card->tty_open;
  	wanpipe_open(card);
  	return 0;
  }
  
  static int wanpipe_tty_write(struct tty_struct * tty, int from_user,
  		    const unsigned char *buf, int count)
  {
  	unsigned long smp_flags=0;
  	sdla_t *card=NULL;
  
  	if (!tty){
  		dbg_printk(KERN_INFO "NO TTY in Write\n");
  		return -ENODEV;
  	}
  
  	card = (sdla_t *)tty->driver_data;
  			
  	if (!card){
  		dbg_printk(KERN_INFO "No Card in TTY Write\n");
  		return -ENODEV;
  	}	
  
  	if (count > card->wandev.mtu){
  		dbg_printk(KERN_INFO "Frame too big in Write %i Max: %i\n",
  				count,card->wandev.mtu);
  		return -EINVAL;
  	}
  	
  	if (card->wandev.state != WAN_CONNECTED){
  		dbg_printk(KERN_INFO "Card not connected in TTY Write\n");
  		return -EINVAL;
  	}
  
  	/* Lock the 508 Card: SMP is supported */
        	if(card->hw.type != SDLA_S514){
  		s508_lock(card,&smp_flags);
  	} 
  	
  	if (test_and_set_bit(SEND_CRIT,(void*)&card->wandev.critical)){
  		printk(KERN_INFO "%s: Critical in TTY Write\n",
  				card->devname);
  		
  		/* Lock the 508 Card: SMP is supported */
  		if(card->hw.type != SDLA_S514)
  			s508_unlock(card,&smp_flags);
  		
  		return -EINVAL; 
  	}
  	
  	if (from_user) {
  		
  		unsigned char *tmp_buf;
  		
  		if ((tmp_buf=card->tty_buf)==NULL){
  			dbg_printk(KERN_INFO "No TTY BUF in Write\n");
  			
  			clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  			
  			if(card->hw.type != SDLA_S514)
  				s508_unlock(card,&smp_flags);
  			
  			return -ENOMEM;
  		}
  		
  		if (copy_from_user(tmp_buf,buf,count)){
  			dbg_printk(KERN_INFO "%s: Failed to copy from user!\n",
  					card->devname);
  			
  			clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  			
  			if(card->hw.type != SDLA_S514)
  				s508_unlock(card,&smp_flags);
  			
  			return -EINVAL;
  		}
  
  		if (chdlc_send(card,(void*)tmp_buf,count)){
  			dbg_printk(KERN_INFO "%s: Failed to send, retry later: user!\n",
  					card->devname);
  			
  			clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  			
  			wanpipe_tty_trigger_tx_irq(card);
  			
  			if(card->hw.type != SDLA_S514)
  				s508_unlock(card,&smp_flags);
  			return 0;
  		}
  
  	}else{
  	 	if (chdlc_send(card,(void*)buf,count)){
  			dbg_printk(KERN_INFO "%s: Failed to send, retry later: kernel!\n",
  					card->devname);
  			clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  	
  			wanpipe_tty_trigger_tx_irq(card);
  			
  			if(card->hw.type != SDLA_S514)
  				s508_unlock(card,&smp_flags);
  			return 0;
  		}
  	}
  	dbg_printk(KERN_INFO "%s: Packet sent OK: %i\n",card->devname,count);
  	clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  	
  	if(card->hw.type != SDLA_S514)
  		s508_unlock(card,&smp_flags);
  
  	return count;
  }
  
  static void wanpipe_tty_receive(sdla_t *card, unsigned addr, unsigned int len)
  {
  	unsigned offset=0;
  	unsigned olen=len;
  	char fp=0;
  	struct tty_struct *tty;
  	int i;
  	
  	if (!card->tty_open){
  		dbg_printk(KERN_INFO "%s: TTY not open during receive\n",
  				card->devname);
  		return;
  	}
  	
  	if ((tty=card->tty) == NULL){
  		dbg_printk(KERN_INFO "%s: No TTY on receive\n",
  				card->devname);
  		return;
  	}
  	
  	if (!tty->driver_data){
  		dbg_printk(KERN_INFO "%s: No Driver Data, or Flip on receive\n",
  				card->devname);
  		return;
  	}
  	
  
  	if (card->u.c.async_mode){
  		if ((tty->flip.count+len) >= TTY_FLIPBUF_SIZE){
  			if (net_ratelimit()){
  				printk(KERN_INFO 
  					"%s: Received packet size too big: %i bytes, Max: %i!\n",
  					card->devname,len,TTY_FLIPBUF_SIZE);
  			}
  			return;
  		}
  
  		
  		if((addr + len) > card->u.c.rx_top + 1) {
  			offset = card->u.c.rx_top - addr + 1;
  			
  			sdla_peek(&card->hw, addr, tty->flip.char_buf_ptr, offset);
  			
  			addr = card->u.c.rx_base;
  			len -= offset;
  			
  			tty->flip.char_buf_ptr+=offset;
  			tty->flip.count+=offset;
  			for (i=0;i<offset;i++){
  				*tty->flip.flag_buf_ptr = 0;
  				tty->flip.flag_buf_ptr++;
  			}
  		}
  		
  		sdla_peek(&card->hw, addr, tty->flip.char_buf_ptr, len);
  			
  		tty->flip.char_buf_ptr+=len;
  		card->tty->flip.count+=len;
  		for (i=0;i<len;i++){
  			*tty->flip.flag_buf_ptr = 0;
  			tty->flip.flag_buf_ptr++;
  		}
  
  		tty->low_latency=1;
  		tty_flip_buffer_push(tty);
  	}else{
  		if (!card->tty_rx){	
  			if (net_ratelimit()){
  				printk(KERN_INFO 
  				"%s: Receive sync buffer not available!\n",
  				 card->devname);
  			}
  			return;
  		}
  	
  		if (len > TTY_CHDLC_MAX_MTU){
  			if (net_ratelimit()){
  				printk(KERN_INFO 
  				"%s: Received packet size too big: %i bytes, Max: %i!\n",
  					card->devname,len,TTY_FLIPBUF_SIZE);
  			}
  			return;
  		}
  
  		
  		if((addr + len) > card->u.c.rx_top + 1) {
  			offset = card->u.c.rx_top - addr + 1;
  			
  			sdla_peek(&card->hw, addr, card->tty_rx, offset);
  			
  			addr = card->u.c.rx_base;
  			len -= offset;
  		}
  		sdla_peek(&card->hw, addr, card->tty_rx+offset, len);
  		if (tty->ldisc.receive_buf){
  			tty->ldisc.receive_buf(tty,card->tty_rx,&fp,olen);
  		}else{
  			if (net_ratelimit()){
  				printk(KERN_INFO 
  					"%s: NO TTY Sync line discipline!\n",
  					card->devname);
  			}
  		}
  	}
  
  	dbg_printk(KERN_INFO "%s: Received Data %i\n",card->devname,olen);
  	return;
  }
  
  
  static void wanpipe_tty_stop(struct tty_struct *tty)
  {
  	return;
  }
  
  static void wanpipe_tty_start(struct tty_struct *tty)
  {
  	return;
  }
  
  static int config_tty (sdla_t *card)
  {
  	SHARED_MEMORY_INFO_STRUCT *flags = card->u.c.flags;
  
  	/* Setup the Board for asynchronous mode */
  	if (card->u.c.async_mode){
  		
  		if (set_asy_config(card)) {
  			printk (KERN_INFO "%s: Failed CHDLC Async configuration!\n",
  				card->devname);
  			return -EINVAL;
  		}
  	}else{
  		/* Setup the Board for CHDLC */
  		if (set_chdlc_config(card)) {
  			printk (KERN_INFO "%s: Failed CHDLC configuration!\n",
  				card->devname);
  			return -EINVAL;
  		}
  	}
  
  	/* Set interrupt mode and mask */
          if (chdlc_set_intr_mode(card, APP_INT_ON_RX_FRAME |
                  		APP_INT_ON_GLOBAL_EXCEP_COND |
                  		APP_INT_ON_TX_FRAME |
                  		APP_INT_ON_CHDLC_EXCEP_COND | APP_INT_ON_TIMER)){
  		printk (KERN_INFO "%s: Failed to set interrupt triggers!\n",
  				card->devname);
  		return -EINVAL;	
          }
  	
  
  	/* Mask the Transmit and Timer interrupt */
  	flags->interrupt_info_struct.interrupt_permission &= 
  		~(APP_INT_ON_TX_FRAME | APP_INT_ON_TIMER);
  
  	
  	/* Enable communications */
   	if (card->u.c.async_mode){
  		if (asy_comm_enable(card) != 0) {
  			printk(KERN_INFO "%s: Failed to enable async commnunication!\n",
  					card->devname);
  			flags->interrupt_info_struct.interrupt_permission = 0;
  			card->u.c.comm_enabled=0;
  			chdlc_set_intr_mode(card,0);
  			return -EINVAL;
  		}
          }else{ 
  		if (chdlc_comm_enable(card) != 0) {
  			printk(KERN_INFO "%s: Failed to enable chdlc communications!\n",
  					card->devname);
  			flags->interrupt_info_struct.interrupt_permission = 0;
  			card->u.c.comm_enabled=0;
  			chdlc_set_intr_mode(card,0);
  			return -EINVAL;
  		}
  	}
  
  	/* Initialize Rx/Tx buffer control fields */
  	init_chdlc_tx_rx_buff(card);
  	port_set_state(card, WAN_CONNECTING);
  	return 0; 
  }
  
  
  static int change_speed(sdla_t *card, struct tty_struct *tty,
  			 struct termios *old_termios)
  {
  	int	baud, ret=0;
  	unsigned cflag; 
  	int	dbits,sbits,parity,handshaking;
  
  	cflag = tty->termios->c_cflag;
  
  	/* There is always one stop bit */
  	sbits=WANOPT_ONE;
  	
  	/* Parity is defaulted to NONE */
  	parity = WANOPT_NONE;
  
  	handshaking=0;
  	
  	/* byte size and parity */
  	switch (cflag & CSIZE) {
  	      case CS5: dbits = 5; break;
  	      case CS6: dbits = 6; break;
  	      case CS7: dbits = 7; break;
  	      case CS8: dbits = 8; break;
  	      /* Never happens, but GCC is too dumb to figure it out */
  	      default:  dbits = 8; break;
  	}
  	
  	/* One more stop bit should be supported, thus increment
  	 * the number of stop bits Max=2 */
  	if (cflag & CSTOPB) {
  		sbits = WANOPT_TWO;
  	}
  	if (cflag & PARENB) {
  		parity = WANOPT_EVEN;
  	}
  	if (cflag & PARODD){
  		parity = WANOPT_ODD;
  	}
  
  	/* Determine divisor based on baud rate */
  	baud = tty_get_baud_rate(tty);
  
  	if (!baud)
  		baud = 9600;	/* B0 transition handled in rs_set_termios */
  
  	if (cflag & CRTSCTS) {
  		handshaking|=ASY_RTS_HS_FOR_RX;
  	}
  	
  	if (I_IGNPAR(tty))
  		parity = WANOPT_NONE;
  
  	if (I_IXOFF(tty)){
  		handshaking|=ASY_XON_XOFF_HS_FOR_RX;
  		handshaking|=ASY_XON_XOFF_HS_FOR_TX;
  	}
  
  	if (I_IXON(tty)){
  		handshaking|=ASY_XON_XOFF_HS_FOR_RX;
  		handshaking|=ASY_XON_XOFF_HS_FOR_TX;
  	}
  
  	if (card->u.c.async_mode){
  		if (card->wandev.bps != baud)
  			ret=1;
  		card->wandev.bps = baud;
  	}
  
  	if (card->u.c.async_mode){
  		if (card->u.c.protocol_options != handshaking)
  			ret=1;
  		card->u.c.protocol_options = handshaking;
  
  		if (card->u.c.tx_bits_per_char != dbits)
  			ret=1;
  		card->u.c.tx_bits_per_char = dbits;
  
  		if (card->u.c.rx_bits_per_char != dbits)
  			ret=1;
  		card->u.c.rx_bits_per_char = dbits;
  		
  		if (card->u.c.stop_bits != sbits)
  			ret=1;
  		card->u.c.stop_bits = sbits;
  
  		if (card->u.c.parity != parity)
  			ret=1;
  		card->u.c.parity = parity;	
  
  		card->u.c.break_timer = 50;
  		card->u.c.inter_char_timer = 10;
  		card->u.c.rx_complete_length = 100;
  		card->u.c.xon_char = 0xFE;
  	}else{
  		card->u.c.protocol_options = HDLC_STREAMING_MODE;
  	}
  	
  	return ret;
  }
  
  	
  static void wanpipe_tty_set_termios(struct tty_struct *tty, struct termios *old_termios)
  {
  	sdla_t *card;
  	int err=1;
  
  	if (!tty){
  		return;
  	}
  
  	card = (sdla_t *)tty->driver_data;
  			
  	if (!card)
  		return;
  
  	if (change_speed(card, tty, old_termios) || !card->u.c.comm_enabled){
  		unsigned long smp_flags;
  		
  		if (card->u.c.comm_enabled){
  			lock_adapter_irq(&card->wandev.lock,&smp_flags);
  			chdlc_disable_comm_shutdown(card);
  			unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  		}
  		lock_adapter_irq(&card->wandev.lock,&smp_flags);
  		err = config_tty(card);
  		unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  		if (card->u.c.async_mode){
  			printk(KERN_INFO "%s: TTY Async Configuration:\n"
  				 "   Baud        =%i\n"
  				 "   Handshaking =%s\n"
  				 "   Tx Dbits    =%i\n"
  				 "   Rx Dbits    =%i\n"
  				 "   Parity      =%s\n"
  				 "   Stop Bits   =%i\n",
  				 card->devname,
  				 card->wandev.bps,
  				 opt_decode[card->u.c.protocol_options],
  				 card->u.c.tx_bits_per_char,
  				 card->u.c.rx_bits_per_char,
  				 p_decode[card->u.c.parity] ,
  				 card->u.c.stop_bits);
  		}else{
  			printk(KERN_INFO "%s: TTY Sync Configuration:\n"
  				 "   Baud        =%i\n"
  				 "   Protocol    =HDLC_STREAMING\n",
  				 card->devname,card->wandev.bps);
  		}
  		if (!err){
  			port_set_state(card,WAN_CONNECTED);
  		}else{
  			port_set_state(card,WAN_DISCONNECTED);
  		}
  	}
  	return;
  }
  
  static void wanpipe_tty_put_char(struct tty_struct *tty, unsigned char ch)
  {
  	sdla_t *card;
  	unsigned long smp_flags=0;
  
  	if (!tty){
  		return;
  	}
  	
  	card = (sdla_t *)tty->driver_data;
  			
  	if (!card)
  		return;
  
  	if (card->wandev.state != WAN_CONNECTED)
  		return;
  
  	if(card->hw.type != SDLA_S514)
  		s508_lock(card,&smp_flags);
  	
  	if (test_and_set_bit(SEND_CRIT,(void*)&card->wandev.critical)){
  		
  		wanpipe_tty_trigger_tx_irq(card);
  
  		if(card->hw.type != SDLA_S514)
  			s508_unlock(card,&smp_flags);
  		return;
  	}
  
  	if (chdlc_send(card,(void*)&ch,1)){
  		wanpipe_tty_trigger_tx_irq(card);
  		dbg_printk("%s: Failed to TX char!\n",card->devname);
  	}
  	
  	dbg_printk("%s: Char TX OK\n",card->devname);
  	
  	clear_bit(SEND_CRIT,(void*)&card->wandev.critical);
  	
  	if(card->hw.type != SDLA_S514)
  		s508_unlock(card,&smp_flags);
  	
  	return;
  }
  
  static void wanpipe_tty_flush_chars(struct tty_struct *tty)
  {
  	return;
  }
  
  static void wanpipe_tty_flush_buffer(struct tty_struct *tty)
  {
  	if (!tty)
  		return;
  	
  	wake_up_interruptible(&tty->write_wait);
  #if defined(SERIAL_HAVE_POLL_WAIT) || \
           (defined LINUX_2_1 && LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,15))
  	wake_up_interruptible(&tty->poll_wait);
  #endif
  	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
  	    tty->ldisc.write_wakeup)
  		(tty->ldisc.write_wakeup)(tty);
  
  	return;
  }
  
  /*
   * This function is used to send a high-priority XON/XOFF character to
   * the device
   */
  static void wanpipe_tty_send_xchar(struct tty_struct *tty, char ch)
  {
  	return;
  }
  
  
  static int wanpipe_tty_chars_in_buffer(struct tty_struct *tty)
  {
  	return 0;
  }
  
  
  static int wanpipe_tty_write_room(struct tty_struct *tty)
  {
  	sdla_t *card;
  
  	printk(KERN_INFO "TTY Write Room\n");
  	
  	if (!tty){
  		return 0;
  	}
  
  	card = (sdla_t *)tty->driver_data;
  	if (!card)
  		return 0;
  
  	if (card->wandev.state != WAN_CONNECTED)
  		return 0;
  	
  	return SEC_MAX_NO_DATA_BYTES_IN_FRAME;
  }
  
  
  static int set_modem_status(sdla_t *card, unsigned char data)
  {
  	CHDLC_MAILBOX_STRUCT *mb = card->mbox;
  	int err;
  
  	mb->buffer_length=1;
  	mb->command=SET_MODEM_STATUS;
  	mb->data[0]=data;
  	err = sdla_exec(mb) ? mb->return_code : CMD_TIMEOUT;
  	if (err != COMMAND_OK) 
  		chdlc_error (card, err, mb);
  	
  	return err;
  }
  
  static void wanpipe_tty_hangup(struct tty_struct *tty)
  {
  	sdla_t *card;
  	unsigned long smp_flags;
  
  	printk(KERN_INFO "TTY Hangup!\n");
  	
  	if (!tty){
  		return;
  	}
  
  	card = (sdla_t *)tty->driver_data;
  	if (!card)
  		return;
  
  	lock_adapter_irq(&card->wandev.lock,&smp_flags);
  	set_modem_status(card,0);
  	unlock_adapter_irq(&card->wandev.lock,&smp_flags);
  	return;
  }
  
  static void wanpipe_tty_break(struct tty_struct *tty, int break_state)
  {
  	return;
  }
  
  static void wanpipe_tty_wait_until_sent(struct tty_struct *tty, int timeout)
  {
  	return;
  }
  
  static void wanpipe_tty_throttle(struct tty_struct * tty)
  {
  	return;
  }
  
  static void wanpipe_tty_unthrottle(struct tty_struct * tty)
  {
  	return;
  }
  
  int wanpipe_tty_read_proc(char *page, char **start, off_t off, int count,
  		 int *eof, void *data)
  {
  	return 0;
  }
  
  /*
   * The serial driver boot-time initialization code!
   */
  int wanpipe_tty_init(sdla_t *card)
  {
  	struct serial_state * state;
  	
  	/* Initialize the tty_driver structure */
  
  	if (card->tty_minor < 0 || card->tty_minor > NR_PORTS){
  		printk(KERN_INFO "%s: Illegal Minor TTY number (0-4): %i\n",
  				card->devname,card->tty_minor);
  		return -EINVAL;
  	}
  
  	if (WAN_CARD(card->tty_minor)){
  		printk(KERN_INFO "%s: TTY Minor %i, already in use\n",
  				card->devname,card->tty_minor);
  		return -EBUSY;
  	}
  
  	if (tty_init_cnt==0){
  		
  		printk(KERN_INFO "%s: TTY %s Driver Init: Major %i, Minor Range %i-%i\n",
  				card->devname,
  				card->u.c.async_mode ? "ASYNC" : "SYNC",
  				WAN_TTY_MAJOR,MIN_PORT,MAX_PORT);
  		
  		tty_driver_mode = card->u.c.async_mode;
  		
  		memset(&serial_driver, 0, sizeof(struct tty_driver));
  		serial_driver.magic = TTY_DRIVER_MAGIC;
  		serial_driver.driver_name = "wanpipe_tty"; 
  		serial_driver.name = "ttyW";
  		serial_driver.major = WAN_TTY_MAJOR;
  		serial_driver.minor_start = WAN_TTY_MINOR;
  		serial_driver.num = NR_PORTS; 
  		serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
  		serial_driver.subtype = SERIAL_TYPE_NORMAL;
  		
  		serial_driver.init_termios = tty_std_termios;
  		serial_driver.init_termios.c_cflag =
  			B9600 | CS8 | CREAD | HUPCL | CLOCAL;
  		serial_driver.flags = TTY_DRIVER_REAL_RAW;
  		
  		serial_driver.refcount = &serial_refcount;
  		serial_driver.table = serial_table;
  		serial_driver.termios = serial_termios;
  		serial_driver.termios_locked = serial_termios_locked;
  
  		serial_driver.open = wanpipe_tty_open;
  		serial_driver.close = wanpipe_tty_close;
  		serial_driver.write = wanpipe_tty_write;
  		
  		serial_driver.put_char = wanpipe_tty_put_char;
  		serial_driver.flush_chars = wanpipe_tty_flush_chars;
  		serial_driver.write_room = wanpipe_tty_write_room;
  		serial_driver.chars_in_buffer = wanpipe_tty_chars_in_buffer;
  		serial_driver.flush_buffer = wanpipe_tty_flush_buffer;
  		//serial_driver.ioctl = wanpipe_tty_ioctl;
  		serial_driver.throttle = wanpipe_tty_throttle;
  		serial_driver.unthrottle = wanpipe_tty_unthrottle;
  		serial_driver.send_xchar = wanpipe_tty_send_xchar;
  		serial_driver.set_termios = wanpipe_tty_set_termios;
  		serial_driver.stop = wanpipe_tty_stop;
  		serial_driver.start = wanpipe_tty_start;
  		serial_driver.hangup = wanpipe_tty_hangup;
  		serial_driver.break_ctl = wanpipe_tty_break;
  		serial_driver.wait_until_sent = wanpipe_tty_wait_until_sent;
  		serial_driver.read_proc = wanpipe_tty_read_proc;
  		
  		/*
  		 * The callout device is just like normal device except for
  		 * major number and the subtype code.
  		 */
  		callout_driver = serial_driver;
  		callout_driver.name = "cuw";
  		callout_driver.major = TTYAUX_MAJOR;
  		callout_driver.subtype = SERIAL_TYPE_CALLOUT;
  		callout_driver.read_proc = 0;
  		callout_driver.proc_entry = 0;
  
  		if (tty_register_driver(&serial_driver)){
  			printk(KERN_INFO "%s: Failed to register serial driver!\n",
  					card->devname);
  		}
  
  		if (tty_register_driver(&callout_driver)){
  			printk(KERN_INFO "%s: Failed to register callout driver!\n",
  					card->devname);
  		}
  
  	}
  
  
  	/* The subsequent ports must comply to the initial configuration */
  	if (tty_driver_mode != card->u.c.async_mode){
  		printk(KERN_INFO "%s: Error: TTY Driver operation mode mismatch!\n",
  				card->devname);
  		printk(KERN_INFO "%s: The TTY driver is configured for %s!\n",
  				card->devname, tty_driver_mode ? "ASYNC" : "SYNC");
  		return -EINVAL;
  	}
  	
  	tty_init_cnt++;
  	
  	printk(KERN_INFO "%s: Initializing TTY %s Driver Minor %i\n",
  			card->devname,
  			tty_driver_mode ? "ASYNC" : "SYNC",
  			card->tty_minor);
  	
  	tty_card_map[card->tty_minor] = card;
  	state = &rs_table[card->tty_minor];
  	
  	state->magic = SSTATE_MAGIC;
  	state->line = 0;
  	state->type = PORT_UNKNOWN;
  	state->custom_divisor = 0;
  	state->close_delay = 5*HZ/10;
  	state->closing_wait = 30*HZ;
  	state->callout_termios = callout_driver.init_termios;
  	state->normal_termios = serial_driver.init_termios;
  	state->icount.cts = state->icount.dsr = 
  		state->icount.rng = state->icount.dcd = 0;
  	state->icount.rx = state->icount.tx = 0;
  	state->icount.frame = state->icount.parity = 0;
  	state->icount.overrun = state->icount.brk = 0;
  	state->irq = card->wandev.irq; 
  
  	card->tty_task_queue.routine = tty_poll_task;
  	card->tty_task_queue.data = (void*)card;
  	return 0;
  }
  
  #endif
  
  
  MODULE_LICENSE("GPL");
  
  /****** End ****************************************************************/
  