sdla_chdlc.c

linux-2.6.15.6

	/* 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;
	dev->tx_timeout		= &if_tx_timeout;
	dev->watchdog_timeo	= TX_TIMEOUT;
	
	/* 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;
	}
	
	if (chdlc_priv_area->true_if_encoding){
		dev->type	= ARPHRD_HDLC; /* This breaks the tcpdump */
	}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;
	SET_MODULE_OWNER(dev);
   
	return 0;
}

/*============================================================================
 * Open network interface.
 * o enable communications and interrupts.
 * o prevent module from unloading by incrementing use count
 *
 * Return 0 if O.k. or errno.
 */
static int if_open(struct net_device* 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 (netif_running(dev))
		return -EBUSY;

	/* Initialize the work queue entry */
	chdlc_priv_area->tq_working=0;

	INIT_WORK(&chdlc_priv_area->common.wanpipe_work,
			(void *)(void *)chdlc_work, 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);
 
	do_gettimeofday(&tv);
	chdlc_priv_area->router_start_time = tv.tv_sec;

	netif_start_queue(dev);

	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;

	/* Start the CHDLC configuration after 1sec delay.
	 * This will give the interface initilization time
	 * to finish its configuration */
	mod_timer(&chdlc_priv_area->poll_delay_timer, jiffies + HZ);
	return err;
}

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

	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){
                		dev_kfree_skb_any(skb);
			}
		}
		kfree(chdlc_priv_area->bh_head);
		chdlc_priv_area->bh_head=NULL;
	}

	netif_stop_queue(dev);
	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 (!tty_init_cnt)
		return;

	if (card->tty_opt){
		struct serial_state * state;
		if (!(--tty_init_cnt)){
			int e1;
			serial_driver.refcount=0;
			
			if ((e1 = tty_unregister_driver(&serial_driver)))
				printk("SERIAL: failed to unregister serial driver (%d)\n",
				       e1);
			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));
	}
	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, struct net_device* dev,
		     unsigned short type, void* daddr, void* saddr,
		     unsigned len)
{
	skb->protocol = htons(type);

	return CHDLC_HDR_LEN;
}


/*============================================================================
 * Handle transmit timeout event from netif watchdog
 */
static void if_tx_timeout(struct net_device *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);
}



/*============================================================================
 * Re-build media header.
 *
 * Return:	1	physical address resolved.
 *		0	physical address not resolved
 */
static int if_rebuild_hdr (struct sk_buff *skb)
{
	return 1;
}


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

	netif_stop_queue(dev);
	
	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);

		netif_wake_queue(dev);
		return 0;
	}

   	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;
			}
			netif_start_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;
			dev_kfree_skb_any(skb);
			netif_start_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;
		netif_start_queue(dev);
		goto if_send_exit_crit;
	}

	if(card->u.c.state != WAN_CONNECTED){
       		++card->wandev.stats.tx_dropped;
		netif_start_queue(dev);
		
	}else if(!skb->protocol){
        	++card->wandev.stats.tx_errors;
		netif_start_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;
				netif_start_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)) {
			netif_stop_queue(dev);
		}else{
			++card->wandev.stats.tx_packets;
                        card->wandev.stats.tx_bytes += len;
			
			netif_start_queue(dev);
			
		 	dev->trans_start = jiffies;
		}	
	}

if_send_exit_crit:
	
	if (!(err=netif_queue_stopped(dev))) {
		dev_kfree_skb_any(skb);
	}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, struct net_device* dev,
				struct sk_buff *skb)
{
	u32 src_ip_addr;
        u32 broadcast_ip_addr = 0;
        struct in_device *in_dev;

        /* read the IP source address from the outgoing packet */
        src_ip_addr = *(u32 *)(skb->data + 12);

	/* read the IP broadcast address for the device */
        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;
        }
 
        /* 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 */