irlap.c

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/*********************************************************************
 *                
 * Filename:      irlap.c
 * Version:       1.0
 * Description:   IrLAP implementation for Linux
 * Status:        Stable
 * Author:        Dag Brattli <[e-mail]>
 * Created at:    Mon Aug  4 20:40:53 1997
 * Modified at:   Tue Dec 14 09:26:44 1999
 * Modified by:   Dag Brattli <[e-mail]>
 * 
 *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
 *     
 *     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.
 * 
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License 
 *     along with this program; if not, write to the Free Software 
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
 *     MA 02111-1307 USA
 *     
 ********************************************************************/

#include <linux/config.h>
#include <linux/malloc.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/random.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h>
#include <net/irda/irqueue.h>
#include <net/irda/irlmp.h>
#include <net/irda/irlmp_frame.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/qos.h>
#include <net/irda/irlap_comp.h>

hashbin_t *irlap = NULL;
int sysctl_slot_timeout = SLOT_TIMEOUT * 1000 / HZ;

static void __irlap_close(struct irlap_cb *self);

static char *lap_reasons[] = {
	"ERROR, NOT USED",
	"LAP_DISC_INDICATION",
	"LAP_NO_RESPONSE",
	"LAP_RESET_INDICATION",
	"LAP_FOUND_NONE",
	"LAP_MEDIA_BUSY",
	"LAP_PRIMARY_CONFLICT",
	"ERROR, NOT USED",
};

#ifdef CONFIG_PROC_FS
int irlap_proc_read(char *, char **, off_t, int);

#endif /* CONFIG_PROC_FS */

int __init irlap_init(void)
{
	/* Allocate master array */
	irlap = hashbin_new(HB_LOCAL);
	if (irlap == NULL) {
	        ERROR(__FUNCTION__ "(), can't allocate irlap hashbin!\n");
		return -ENOMEM;
	}

#ifdef CONFIG_IRDA_COMPRESSION
	irlap_compressors = hashbin_new(HB_LOCAL);
	if (irlap_compressors == NULL) {
		WARNING(__FUNCTION__ 
			"(), can't allocate compressors hashbin!\n");
		return -ENOMEM;
	}
#endif

	return 0;
}

void irlap_cleanup(void)
{
	ASSERT(irlap != NULL, return;);

	hashbin_delete(irlap, (FREE_FUNC) __irlap_close);

#ifdef CONFIG_IRDA_COMPRESSION
	hashbin_delete(irlap_compressors, (FREE_FUNC) kfree);
#endif
}

/*
 * Function irlap_open (driver)
 *
 *    Initialize IrLAP layer
 *
 */
struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos)
{
	struct irlap_cb *self;

	IRDA_DEBUG(4, __FUNCTION__ "()\n");
	
	/* Initialize the irlap structure. */
	self = kmalloc(sizeof(struct irlap_cb), GFP_KERNEL);
	if (self == NULL)
		return NULL;
	
	memset(self, 0, sizeof(struct irlap_cb));
	self->magic = LAP_MAGIC;

	/* Make a binding between the layers */
	self->netdev = dev;
	self->qos_dev = qos;

	/* FIXME: should we get our own field? */
	dev->atalk_ptr = self;

	irlap_next_state(self, LAP_OFFLINE);

	/* Initialize transmit queue */
	skb_queue_head_init(&self->txq);
	skb_queue_head_init(&self->txq_ultra);
	skb_queue_head_init(&self->wx_list);

	/* My unique IrLAP device address! */
	get_random_bytes(&self->saddr, sizeof(self->saddr));
	memcpy(dev->dev_addr, &self->saddr, 4);

	init_timer(&self->slot_timer);
	init_timer(&self->query_timer);
	init_timer(&self->discovery_timer);
	init_timer(&self->final_timer);		
	init_timer(&self->poll_timer);
	init_timer(&self->wd_timer);
	init_timer(&self->backoff_timer);
	init_timer(&self->media_busy_timer);	

	irlap_apply_default_connection_parameters(self);

	self->N3 = 3; /* # connections attemts to try before giving up */
	
	irlap_next_state(self, LAP_NDM);

	hashbin_insert(irlap, (irda_queue_t *) self, self->saddr, NULL);

	irlmp_register_link(self, self->saddr, &self->notify);
	
	return self;
}

/*
 * Function __irlap_close (self)
 *
 *    Remove IrLAP and all allocated memory. Stop any pending timers.
 *
 */
static void __irlap_close(struct irlap_cb *self)
{
	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	/* Stop timers */
	del_timer(&self->slot_timer);
	del_timer(&self->query_timer);
	del_timer(&self->discovery_timer);
	del_timer(&self->final_timer);		
	del_timer(&self->poll_timer);
	del_timer(&self->wd_timer);
	del_timer(&self->backoff_timer);
	del_timer(&self->media_busy_timer);

	irlap_flush_all_queues(self);
       
	self->magic = 0;
	
	kfree(self);
}

/*
 * Function irlap_close (self)
 *
 *    Remove IrLAP instance
 *
 */
void irlap_close(struct irlap_cb *self) 
{
	struct irlap_cb *lap;

	IRDA_DEBUG(4, __FUNCTION__ "()\n");
	
	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	irlap_disconnect_indication(self, LAP_DISC_INDICATION);

	irlmp_unregister_link(self->saddr);
	self->notify.instance = NULL;

	/* Be sure that we manage to remove ourself from the hash */
	lap = hashbin_remove(irlap, self->saddr, NULL);
	if (!lap) {
		IRDA_DEBUG(1, __FUNCTION__ "(), Didn't find myself!\n");
		return;
	}
	__irlap_close(lap);
}

/*
 * Function irlap_connect_indication (self, skb)
 *
 *    Another device is attempting to make a connection
 *
 */
void irlap_connect_indication(struct irlap_cb *self, struct sk_buff *skb) 
{
	IRDA_DEBUG(4, __FUNCTION__ "()\n");

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	irlap_init_qos_capabilities(self, NULL); /* No user QoS! */

	skb_get(skb); /*LEVEL4*/
	irlmp_link_connect_indication(self->notify.instance, self->saddr, 
				      self->daddr, &self->qos_tx, skb);
}

/*
 * Function irlap_connect_response (self, skb)
 *
 *    Service user has accepted incomming connection
 *
 */
void irlap_connect_response(struct irlap_cb *self, struct sk_buff *skb) 
{
	IRDA_DEBUG(4, __FUNCTION__ "()\n");
	
	irlap_do_event(self, CONNECT_RESPONSE, skb, NULL);
	kfree_skb(skb);
}

/*
 * Function irlap_connect_request (self, daddr, qos_user, sniff)
 *
 *    Request connection with another device, sniffing is not implemented 
 *    yet.
 *
 */
void irlap_connect_request(struct irlap_cb *self, __u32 daddr, 
			   struct qos_info *qos_user, int sniff) 
{
	IRDA_DEBUG(3, __FUNCTION__ "(), daddr=0x%08x\n", daddr);

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

 	self->daddr = daddr;
	
	/*
	 *  If the service user specifies QoS values for this connection, 
	 *  then use them
	 */
	irlap_init_qos_capabilities(self, qos_user);
	
	if ((self->state == LAP_NDM) && !self->media_busy)
		irlap_do_event(self, CONNECT_REQUEST, NULL, NULL);
	else
		self->connect_pending = TRUE;
}

/*
 * Function irlap_connect_confirm (self, skb)
 *
 *    Connection request has been accepted
 *
 */
void irlap_connect_confirm(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(4, __FUNCTION__ "()\n");

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	skb_get(skb); /*LEVEL4*/
	irlmp_link_connect_confirm(self->notify.instance, &self->qos_tx, skb);
}

/*
 * Function irlap_data_indication (self, skb)
 *
 *    Received data frames from IR-port, so we just pass them up to 
 *    IrLMP for further processing
 *
 */
void irlap_data_indication(struct irlap_cb *self, struct sk_buff *skb,
			   int unreliable) 
{
	/* Hide LAP header from IrLMP layer */
	skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

#ifdef CONFIG_IRDA_COMPRESSION
	if (self->qos_tx.compression.value) {
		skb_get(skb); /*LEVEL4*/
		skb = irlap_decompress_frame(self, skb);
		if (!skb) {
			IRDA_DEBUG(1, __FUNCTION__ "(), Decompress error!\n");
			return;
		}
	}
#endif
	skb_get(skb); /*LEVEL4*/
	irlmp_link_data_indication(self->notify.instance, skb, unreliable);
}


/*
 * Function irlap_data_request (self, skb)
 *
 *    Queue data for transmission, must wait until XMIT state
 *
 */
void irlap_data_request(struct irlap_cb *self, struct sk_buff *skb, 
			int unreliable)
{
	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, __FUNCTION__ "()\n");

#ifdef CONFIG_IRDA_COMPRESSION
	if (self->qos_tx.compression.value) {
		skb = irlap_compress_frame(self, skb);
		if (!skb) {
			IRDA_DEBUG(1, __FUNCTION__ "(), Compress error!\n");
			return;
		}
	}
#endif
	ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER), 
	       return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	/*  
	 *  Must set frame format now so that the rest of the code knows 
	 *  if its dealing with an I or an UI frame
	 */
	if (unreliable)
		skb->data[1] = UI_FRAME;
	else
		skb->data[1] = I_FRAME;

	/* 
	 *  Send event if this frame only if we are in the right state 
	 *  FIXME: udata should be sent first! (skb_queue_head?)
	 */
  	if ((self->state == LAP_XMIT_P) || (self->state == LAP_XMIT_S)) {
		/*
		 *  Check if the transmit queue contains some unsent frames,
		 *  and if so, make sure they are sent first
		 */
		if (!skb_queue_empty(&self->txq)) {
			skb_queue_tail(&self->txq, skb);
			skb = skb_dequeue(&self->txq);
			
			ASSERT(skb != NULL, return;);
		}
		irlap_do_event(self, SEND_I_CMD, skb, NULL);
		kfree_skb(skb);
	} else
		skb_queue_tail(&self->txq, skb);
}

/*
 * Function irlap_unitdata_request (self, skb)
 *
 *    Send Ultra data. This is data that must be sent outside any connection
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlap_unitdata_request(struct irlap_cb *self, struct sk_buff *skb)
{
	ASSERT(self != NULL, return;);
	ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, __FUNCTION__ "()\n");

	ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER), 
	       return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	skb->data[0] = CBROADCAST;
	skb->data[1] = UI_FRAME;

	skb_queue_tail(&self->txq_ultra, skb);

	irlap_do_event(self, SEND_UI_FRAME, NULL, NULL);
}
#endif /*CONFIG_IRDA_ULTRA */

/*
 * Function irlap_udata_indication (self, skb)
 *
 *    Receive Ultra data. This is data that is received outside any connection
 *
 */