irlap.c

Go to the documentation of this file.

/*********************************************************************
 *                
 * Filename:      irlap.c
 * Version:       1.0
 * Description:   IrLAP implementation for Linux
 * Status:        Stable
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Mon Aug  4 20:40:53 1997
 * Modified at:   Tue Dec 14 09:26:44 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * 
 *     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, 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 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, (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! */
        
        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);
}

/*
 * 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;);

        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 = irlap_decompress_frame(self, skb);
                if (!skb) {
                        IRDA_DEBUG(1, __FUNCTION__ "(), Decompress error!\n");
                        return;
                }
        }
#endif
        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);
        } 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
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlap_unitdata_indication(struct irlap_cb *self, struct sk_buff *skb)
{
        IRDA_DEBUG(1, __FUNCTION__ "()\n"); 

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

        /* Hide LAP header from IrLMP layer */
        skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

        irlmp_link_unitdata_indication(self->notify.instance, skb);
}
#endif /* CONFIG_IRDA_ULTRA */

/*
 * Function irlap_disconnect_request (void)
 *
 *    Request to disconnect connection by service user
 */
void irlap_disconnect_request(struct irlap_cb *self) 
{
        IRDA_DEBUG(3, __FUNCTION__ "()\n");

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        
        /* Don't disconnect until all data frames are successfully sent */
        if (skb_queue_len(&self->txq) > 0) {
                self->disconnect_pending = TRUE;
                
                return;
        }

        /* Check if we are in the right state for disconnecting */
        switch (self->state) {
        case LAP_XMIT_P:        /* FALLTROUGH */
        case LAP_XMIT_S:        /* FALLTROUGH */
        case LAP_CONN:          /* FALLTROUGH */
        case LAP_RESET_WAIT:    /* FALLTROUGH */
        case LAP_RESET_CHECK:   
                irlap_do_event(self, DISCONNECT_REQUEST, NULL, NULL);
                break;
        default:
                IRDA_DEBUG(2, __FUNCTION__ "(), disconnect pending!\n");
                self->disconnect_pending = TRUE;
                break;
        }
}

/*
 * Function irlap_disconnect_indication (void)
 *
 *    Disconnect request from other device
 *
 */
void irlap_disconnect_indication(struct irlap_cb *self, LAP_REASON reason) 
{
        IRDA_DEBUG(1, __FUNCTION__ "(), reason=%s\n", lap_reasons[reason]); 

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

#ifdef CONFIG_IRDA_COMPRESSION
        irda_free_compression(self);
#endif
        /* Flush queues */
        irlap_flush_all_queues(self);
        
        switch (reason) {
        case LAP_RESET_INDICATION:
                IRDA_DEBUG(1, __FUNCTION__ "(), Sending reset request!\n");
                irlap_do_event(self, RESET_REQUEST, NULL, NULL);
                break;
        case LAP_NO_RESPONSE:      /* FALLTROUGH */     
        case LAP_DISC_INDICATION:  /* FALLTROUGH */
        case LAP_FOUND_NONE:       /* FALLTROUGH */
        case LAP_MEDIA_BUSY:
                irlmp_link_disconnect_indication(self->notify.instance, self, 
                                                 reason, NULL);
                break;
        default:
                ERROR(__FUNCTION__ "(), Unknown reason %d\n", reason);
        }
}

/*
 * Function irlap_discovery_request (gen_addr_bit)
 *
 *    Start one single discovery operation.
 *
 */
void irlap_discovery_request(struct irlap_cb *self, discovery_t *discovery) 
{
        struct irlap_info info;
        
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        ASSERT(discovery != NULL, return;);
        
        IRDA_DEBUG(4, __FUNCTION__ "(), nslots = %d\n", discovery->nslots);

        ASSERT((discovery->nslots == 1) || (discovery->nslots == 6) ||
               (discovery->nslots == 8) || (discovery->nslots == 16), 
               return;);
        
        /* Discovery is only possible in NDM mode */
        if (self->state != LAP_NDM) {
                IRDA_DEBUG(4, __FUNCTION__ 
                           "(), discovery only possible in NDM mode\n");
                irlap_discovery_confirm(self, NULL);
                return;
        }

        /* Check if last discovery request finished in time */
        if (self->discovery_log != NULL) {
                hashbin_delete(self->discovery_log, (FREE_FUNC) kfree);
                self->discovery_log = NULL;
        }
        
        self->discovery_log= hashbin_new(HB_LOCAL);
        
        info.S = discovery->nslots; /* Number of slots */
        info.s = 0; /* Current slot */
        
        self->discovery_cmd = discovery;
        info.discovery = discovery;
        
        /* Check if the slot timeout is within limits */
        if (sysctl_slot_timeout < 20) {
                ERROR(__FUNCTION__ 
                      "(), to low value for slot timeout!\n");
                sysctl_slot_timeout = 20;
        }
        /* 
         * Highest value is actually 8, but we allow higher since
         * some devices seems to require it.
         */
        if (sysctl_slot_timeout > 160) {
                ERROR(__FUNCTION__ 
                      "(), to high value for slot timeout!\n");
                sysctl_slot_timeout = 160;
        }
        
        self->slot_timeout = sysctl_slot_timeout * HZ / 1000;
        
        irlap_do_event(self, DISCOVERY_REQUEST, NULL, &info);
}

/*
 * Function irlap_discovery_confirm (log)
 *
 *    A device has been discovered in front of this station, we
 *    report directly to LMP.
 */
void irlap_discovery_confirm(struct irlap_cb *self, hashbin_t *discovery_log) 
{
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        
        ASSERT(self->notify.instance != NULL, return;);
        
        /* 
         * Check for successful discovery, since we are then allowed to clear 
         * the media busy condition (irlap p.94). This should allow us to make 
         * connection attempts much easier.
         */
        if (discovery_log && HASHBIN_GET_SIZE(discovery_log) > 0)
                irda_device_set_media_busy(self->netdev, FALSE);
        
        /* Inform IrLMP */
        irlmp_link_discovery_confirm(self->notify.instance, discovery_log);
}

/*
 * Function irlap_discovery_indication (log)
 *
 *    Somebody is trying to discover us!
 *
 */
void irlap_discovery_indication(struct irlap_cb *self, discovery_t *discovery) 
{
        IRDA_DEBUG(4, __FUNCTION__ "()\n");

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

        ASSERT(self->notify.instance != NULL, return;);
        
        irlmp_link_discovery_indication(self->notify.instance, discovery);
}

/*
 * Function irlap_status_indication (quality_of_link)
 *
 *    
 *
 */
void irlap_status_indication(int quality_of_link) 
{
        switch (quality_of_link) {
        case STATUS_NO_ACTIVITY:
                MESSAGE("IrLAP, no activity on link!\n");
                break;
        case STATUS_NOISY:
                MESSAGE("IrLAP, noisy link!\n");
                break;
        default:
                break;
        }
        irlmp_status_indication(quality_of_link, LOCK_NO_CHANGE);
}

/*
 * Function irlap_reset_indication (void)
 *
 *    
 *
 */
void irlap_reset_indication(struct irlap_cb *self)
{
        IRDA_DEBUG(1, __FUNCTION__ "()\n");

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        
        if (self->state == LAP_RESET_WAIT)
                irlap_do_event(self, RESET_REQUEST, NULL, NULL);
        else
                irlap_do_event(self, RESET_RESPONSE, NULL, NULL);
}

/*
 * Function irlap_reset_confirm (void)
 *
 *    
 *
 */
void irlap_reset_confirm(void)
{
        IRDA_DEBUG(1, __FUNCTION__ "()\n");
}

/*
 * Function irlap_generate_rand_time_slot (S, s)
 *
 *    Generate a random time slot between s and S-1 where
 *    S = Number of slots (0 -> S-1)
 *    s = Current slot
 */
int irlap_generate_rand_time_slot(int S, int s) 
{
        int slot;
        
        ASSERT((S - s) > 0, return 0;);

        slot = s + jiffies % (S-s);
        
        ASSERT((slot >= s) || (slot < S), return 0;);
        
        return slot;
}

/*
 * Function irlap_update_nr_received (nr)
 *
 *    Remove all acknowledged frames in current window queue. This code is 
 *    not intuitive and you should not try to change it. If you think it
 *    contains bugs, please mail a patch to the author instead.
 */
void irlap_update_nr_received(struct irlap_cb *self, int nr) 
{
        struct sk_buff *skb = NULL;
        int count = 0;

        /*
         * Remove all the ack-ed frames from the window queue.
         */

        /* 
         *  Optimize for the common case. It is most likely that the receiver
         *  will acknowledge all the frames we have sent! So in that case we
         *  delete all frames stored in window.
         */
        if (nr == self->vs) {
                while ((skb = skb_dequeue(&self->wx_list)) != NULL) {
                        dev_kfree_skb(skb);
                }
                /* The last acked frame is the next to send minus one */
                self->va = nr - 1;
        } else {
                /* Remove all acknowledged frames in current window */
                while ((skb_peek(&self->wx_list) != NULL) && 
                       (((self->va+1) % 8) != nr)) 
                {
                        skb = skb_dequeue(&self->wx_list);
                        dev_kfree_skb(skb);
                        
                        self->va = (self->va + 1) % 8;
                        count++;
                }
        }
        
        /* Advance window */
        self->window = self->window_size - skb_queue_len(&self->wx_list);
}

/*
 * Function irlap_validate_ns_received (ns)
 *
 *    Validate the next to send (ns) field from received frame.
 */
int irlap_validate_ns_received(struct irlap_cb *self, int ns) 
{
        /*  ns as expected?  */
        if (ns == self->vr)
                return NS_EXPECTED;
        /*
         *  Stations are allowed to treat invalid NS as unexpected NS
         *  IrLAP, Recv ... with-invalid-Ns. p. 84
         */
        return NS_UNEXPECTED;
        
        /* return NR_INVALID; */
}
/*
 * Function irlap_validate_nr_received (nr)
 *
 *    Validate the next to receive (nr) field from received frame.
 *
 */
int irlap_validate_nr_received(struct irlap_cb *self, int nr) 
{
        /*  nr as expected?  */
        if (nr == self->vs) {
                IRDA_DEBUG(4, __FUNCTION__ "(), expected!\n");
                return NR_EXPECTED;
        }

        /*
         *  unexpected nr? (but within current window), first we check if the 
         *  ns numbers of the frames in the current window wrap.
         */
        if (self->va < self->vs) {
                if ((nr >= self->va) && (nr <= self->vs))
                        return NR_UNEXPECTED;
        } else {
                if ((nr >= self->va) || (nr <= self->vs)) 
                        return NR_UNEXPECTED;
        }
        
        /* Invalid nr!  */
        return NR_INVALID;
}

/*
 * Function irlap_initiate_connection_state ()
 *
 *    Initialize the connection state parameters
 *
 */
void irlap_initiate_connection_state(struct irlap_cb *self) 
{
        IRDA_DEBUG(4, __FUNCTION__ "()\n");
        
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);

        /* Next to send and next to receive */
        self->vs = self->vr = 0;

        /* Last frame which got acked (0 - 1) % 8 */
        self->va = 7;

        self->window = 1;

        self->remote_busy = FALSE;
        self->retry_count = 0;
}

/*
 * Function irlap_wait_min_turn_around (self, qos)
 *
 *    Wait negotiated minimum turn around time, this function actually sets
 *    the number of BOS's that must be sent before the next transmitted
 *    frame in order to delay for the specified amount of time. This is
 *    done to avoid using timers, and the forbidden udelay!
 */
void irlap_wait_min_turn_around(struct irlap_cb *self, struct qos_info *qos) 
{
        __u32 min_turn_time;
        __u32 speed;
        
        /* Get QoS values.  */
        speed = qos->baud_rate.value;
        min_turn_time = qos->min_turn_time.value;

        /* No need to calculate XBOFs for speeds over 115200 bps */
        if (speed > 115200) {
                self->mtt_required = min_turn_time;
                return;
        }
        
        /*  
         *  Send additional BOF's for the next frame for the requested
         *  min turn time, so now we must calculate how many chars (XBOF's) we 
         *  must send for the requested time period (min turn time)
         */
        self->xbofs_delay = irlap_min_turn_time_in_bytes(speed, min_turn_time);
}

/*
 * Function irlap_flush_all_queues (void)
 *
 *    Flush all queues
 *
 */
void irlap_flush_all_queues(struct irlap_cb *self) 
{
        struct sk_buff* skb;

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

        /* Free transmission queue */
        while ((skb = skb_dequeue(&self->txq)) != NULL)
                dev_kfree_skb(skb);
        
        while ((skb = skb_dequeue(&self->txq_ultra)) != NULL)
                dev_kfree_skb(skb);

        /* Free sliding window buffered packets */
        while ((skb = skb_dequeue(&self->wx_list)) != NULL)
                dev_kfree_skb(skb);

#ifdef CONFIG_IRDA_RECYCLE_RR
        if (self->recycle_rr_skb) { 
                dev_kfree_skb(self->recycle_rr_skb);
                self->recycle_rr_skb = NULL;
        }
#endif
}

/*
 * Function irlap_setspeed (self, speed)
 *
 *    Change the speed of the IrDA port
 *
 */
void irlap_change_speed(struct irlap_cb *self, __u32 speed, int now)
{
        IRDA_DEBUG(0, __FUNCTION__ "(), setting speed to %d\n", speed);

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

        self->speed = speed;

        /* Change speed now, or just piggyback speed on frames */
        if (now)
                irda_device_change_speed(self->netdev, speed);
}

#ifdef CONFIG_IRDA_COMPRESSION
void irlap_init_comp_qos_capabilities(struct irlap_cb *self)
{
        struct irda_compressor *comp;
        __u8 mask; /* Current bit tested */
        int i;

        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        
        /* 
         *  Find out which compressors we support. We do this be checking that
         *  the corresponding compressor for each bit set in the QoS bits has 
         *  actually been loaded. Ths is sort of hairy code but that is what 
         *  you get when you do a little bit flicking :-)
         */
        IRDA_DEBUG(4, __FUNCTION__ "(), comp bits 0x%02x\n", 
                   self->qos_rx.compression.bits); 
        mask = 0x80; /* Start with testing MSB */
        for (i=0;i<8;i++) {
                IRDA_DEBUG(4, __FUNCTION__ "(), testing bit %d\n", 8-i);
                if (self->qos_rx.compression.bits & mask) {
                        IRDA_DEBUG(4, __FUNCTION__ 
                                   "(), bit %d is set by defalt\n", 8-i);
                        comp = hashbin_find(irlap_compressors, 
                                            compressions[msb_index(mask)], 
                                            NULL);
                        if (!comp) {
                                /* Protocol not supported, so clear the bit */
                                IRDA_DEBUG(4, __FUNCTION__ "(), Compression "
                                           "protocol %d has not been loaded!\n", 
                                           compressions[msb_index(mask)]);
                                self->qos_rx.compression.bits &= ~mask;
                                IRDA_DEBUG(4, __FUNCTION__ 
                                           "(), comp bits 0x%02x\n", 
                                           self->qos_rx.compression.bits); 
                        }
                }
                /* Try the next bit */
                mask >>= 1;
        }
}
#endif  

/*
 * Function irlap_init_qos_capabilities (self, qos)
 *
 *    Initialize QoS for this IrLAP session, What we do is to compute the
 *    intersection of the QoS capabilities for the user, driver and for
 *    IrLAP itself. Normally, IrLAP will not specify any values, but it can
 *    be used to restrict certain values.
 */
void irlap_init_qos_capabilities(struct irlap_cb *self,
                                 struct qos_info *qos_user)
{
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);
        ASSERT(self->netdev != NULL, return;);

        /* Start out with the maximum QoS support possible */
        irda_init_max_qos_capabilies(&self->qos_rx);

#ifdef CONFIG_IRDA_COMPRESSION
        irlap_init_comp_qos_capabilities(self);
#endif

        /* Apply drivers QoS capabilities */
        irda_qos_compute_intersection(&self->qos_rx, self->qos_dev);

        /*
         *  Check for user supplied QoS parameters. The service user is only 
         *  allowed to supply these values. We check each parameter since the
         *  user may not have set all of them.
         */
        if (qos_user) {
                IRDA_DEBUG(1, __FUNCTION__ "(), Found user specified QoS!\n");

                if (qos_user->baud_rate.bits)
                        self->qos_rx.baud_rate.bits &= qos_user->baud_rate.bits;

                if (qos_user->max_turn_time.bits)
                        self->qos_rx.max_turn_time.bits &= qos_user->max_turn_time.bits;
                if (qos_user->data_size.bits)
                        self->qos_rx.data_size.bits &= qos_user->data_size.bits;

                if (qos_user->link_disc_time.bits)
                        self->qos_rx.link_disc_time.bits &= qos_user->link_disc_time.bits;
#ifdef CONFIG_IRDA_COMPRESSION
                self->qos_rx.compression.bits &= qos_user->compression.bits;
#endif
        }

        /* Use 500ms in IrLAP for now */
        self->qos_rx.max_turn_time.bits &= 0x01;

        /* Set data size */
        /*self->qos_rx.data_size.bits &= 0x03;*/

        /* Set disconnect time */
        self->qos_rx.link_disc_time.bits &= 0x07;

        irda_qos_bits_to_value(&self->qos_rx);
}

/*
 * Function irlap_apply_default_connection_parameters (void)
 *
 *    Use the default connection and transmission parameters
 * 
 */
void irlap_apply_default_connection_parameters(struct irlap_cb *self)
{
        IRDA_DEBUG(4, __FUNCTION__ "()\n");

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

        irlap_change_speed(self, 9600, TRUE);

        /* Set mbusy when going to NDM state */
        irda_device_set_media_busy(self->netdev, TRUE);

        /* Default value in NDM */
        self->bofs_count = 11;

        /* 
         * Generate random connection address for this session, which must
         * be 7 bits wide and different from 0x00 and 0xfe 
         */
        while ((self->caddr == 0x00) || (self->caddr == 0xfe)) {
                get_random_bytes(&self->caddr, sizeof(self->caddr));
                self->caddr &= 0xfe;
        }

        /* Use default values until connection has been negitiated */
        self->slot_timeout = sysctl_slot_timeout;
        self->final_timeout = FINAL_TIMEOUT;
        self->poll_timeout = POLL_TIMEOUT;
        self->wd_timeout = WD_TIMEOUT;

        /* Set some default values */
        self->qos_tx.baud_rate.value = 9600;
        self->qos_rx.baud_rate.value = 9600;
        self->qos_tx.max_turn_time.value = 0;
        self->qos_rx.max_turn_time.value = 0;
        self->qos_tx.min_turn_time.value = 0;
        self->qos_rx.min_turn_time.value = 0;
        self->qos_tx.data_size.value = 64;
        self->qos_rx.data_size.value = 64;
        self->qos_tx.window_size.value = 1;
        self->qos_rx.window_size.value = 1;
        self->qos_tx.additional_bofs.value = 11;
        self->qos_rx.additional_bofs.value = 11;
        self->qos_tx.link_disc_time.value = 0;
        self->qos_rx.link_disc_time.value = 0;

        irlap_flush_all_queues(self);

        self->disconnect_pending = FALSE;
        self->connect_pending = FALSE;
}

/*
 * Function irlap_apply_connection_parameters (qos)
 *
 *    Initialize IrLAP with the negotiated QoS values
 *
 */
void irlap_apply_connection_parameters(struct irlap_cb *self) 
{
        IRDA_DEBUG(4, __FUNCTION__ "()\n");
        
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == LAP_MAGIC, return;);

        irlap_change_speed(self, self->qos_tx.baud_rate.value, FALSE);

        self->window_size = self->qos_tx.window_size.value;
        self->window      = self->qos_tx.window_size.value;
        self->bofs_count  = self->qos_tx.additional_bofs.value;

        /*
         *  Calculate how many bytes it is possible to transmit before the
         *  link must be turned around
         */
        self->line_capacity = 
                irlap_max_line_capacity(self->qos_tx.baud_rate.value,
                                        self->qos_tx.max_turn_time.value);
        /*
         *  Set N1 to 0 if Link Disconnect/Threshold Time = 3 and set it to 
         *  3 seconds otherwise. See page 71 in IrLAP for more details.
         *  TODO: these values should be calculated from the final timer
         *  as well
         */
        ASSERT(self->qos_tx.max_turn_time.value != 0, return;);
        if (self->qos_tx.link_disc_time.value == 3)
                self->N1 = 0;
        else
                self->N1 = 3000 / self->qos_tx.max_turn_time.value;
        
        IRDA_DEBUG(4, "Setting N1 = %d\n", self->N1);
        
        
        self->N2 = self->qos_tx.link_disc_time.value * 1000 / 
                self->qos_tx.max_turn_time.value;
        IRDA_DEBUG(4, "Setting N2 = %d\n", self->N2);

        /* 
         *  Initialize timeout values, some of the rules are listed on 
         *  page 92 in IrLAP.
         */
        self->poll_timeout = self->qos_tx.max_turn_time.value * HZ / 1000;
        self->wd_timeout = self->poll_timeout * 2;

        /* 
         * Be careful to keep our promises to the peer device about how long
         * time it can keep the pf bit. So here we must use the rx_qos value
         */
        self->final_timeout = self->qos_rx.max_turn_time.value * HZ / 1000;

#ifdef CONFIG_IRDA_COMPRESSION
        if (self->qos_tx.compression.value) {
                IRDA_DEBUG(1, __FUNCTION__ "(), Initializing compression\n");
                irda_set_compression(self, self->qos_tx.compression.value);

                irlap_compressor_init(self, 0);
        }
#endif
}

/*
 * Function irlap_set_local_busy (self, status)
 *
 *    
 *
 */
void irlap_set_local_busy(struct irlap_cb *self, int status)
{
        IRDA_DEBUG(0, __FUNCTION__ "()\n");

        self->local_busy = status;
        
        if (status)
                IRDA_DEBUG(0, __FUNCTION__ "(), local busy ON\n");
        else
                IRDA_DEBUG(0, __FUNCTION__ "(), local busy OFF\n");
}

#ifdef CONFIG_PROC_FS
/*
 * Function irlap_proc_read (buf, start, offset, len, unused)
 *
 *    Give some info to the /proc file system
 *
 */
int irlap_proc_read(char *buf, char **start, off_t offset, int len, 
                    int unused)
{
        struct irlap_cb *self;
        unsigned long flags;
        int i = 0;
     
        save_flags(flags);
        cli();

        len = 0;

        self = (struct irlap_cb *) hashbin_get_first(irlap);
        while (self != NULL) {
                ASSERT(self != NULL, return -ENODEV;);
                ASSERT(self->magic == LAP_MAGIC, return -EBADR;);

                len += sprintf(buf+len, "irlap%d ", i++);
                len += sprintf(buf+len, "state: %s\n", 
                               irlap_state[self->state]);
                
                len += sprintf(buf+len, "  caddr: %#02x, ", self->caddr);
                len += sprintf(buf+len, "saddr: %#08x, ", self->saddr);
                len += sprintf(buf+len, "daddr: %#08x\n", self->daddr);
                
                len += sprintf(buf+len, "  win size: %d, ", 
                               self->window_size);
                len += sprintf(buf+len, "win: %d, ", self->window);
#if CONFIG_IRDA_DYNAMIC_WINDOW
                len += sprintf(buf+len, "line capacity: %d, ", 
                               self->line_capacity);
                len += sprintf(buf+len, "bytes left: %d\n", self->bytes_left);
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
                len += sprintf(buf+len, "  tx queue len: %d ", 
                               skb_queue_len(&self->txq));
                len += sprintf(buf+len, "win queue len: %d ", 
                               skb_queue_len(&self->wx_list));
                len += sprintf(buf+len, "rbusy: %s", self->remote_busy ?
                               "TRUE" : "FALSE");
                len += sprintf(buf+len, " mbusy: %s\n", self->media_busy ?
                               "TRUE" : "FALSE");
                
                len += sprintf(buf+len, "  retrans: %d ", self->retry_count);
                len += sprintf(buf+len, "vs: %d ", self->vs);
                len += sprintf(buf+len, "vr: %d ", self->vr);
                len += sprintf(buf+len, "va: %d\n", self->va);
                
                len += sprintf(buf+len, "  qos\tbps\tmaxtt\tdsize\twinsize\taddbofs\tmintt\tldisc\tcomp\n");
                
                len += sprintf(buf+len, "  tx\t%d\t", 
                               self->qos_tx.baud_rate.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_tx.max_turn_time.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_tx.data_size.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_tx.window_size.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_tx.additional_bofs.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_tx.min_turn_time.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_tx.link_disc_time.value);
#ifdef CONFIG_IRDA_COMPRESSION
                len += sprintf(buf+len, "%d",
                               self->qos_tx.compression.value);
#endif
                len += sprintf(buf+len, "\n");

                len += sprintf(buf+len, "  rx\t%d\t", 
                               self->qos_rx.baud_rate.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_rx.max_turn_time.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_rx.data_size.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_rx.window_size.value);
                len += sprintf(buf+len, "%d\t",
                               self->qos_rx.additional_bofs.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_rx.min_turn_time.value);
                len += sprintf(buf+len, "%d\t", 
                               self->qos_rx.link_disc_time.value);
#ifdef CONFIG_IRDA_COMPRESSION
                len += sprintf(buf+len, "%d",
                               self->qos_rx.compression.value);
#endif
                len += sprintf(buf+len, "\n");
                
                self = (struct irlap_cb *) hashbin_get_next(irlap);
        }
        restore_flags(flags);

        return len;
}

#endif /* CONFIG_PROC_FS */

---