ring-buffer: Make non-consuming read less expensive with lots of cpus.

[zen-stable.git] / net / irda / irlmp.c

/*********************************************************************
 *
 * Filename:      irlmp.c
 * Version:       1.0
 * Description:   IrDA Link Management Protocol (LMP) layer
 * Status:        Stable.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Sun Aug 17 20:54:32 1997
 * Modified at:   Wed Jan  5 11:26:03 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
 *     All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     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.
 *
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/random.h>
#include <linux/seq_file.h>

#include <net/irda/irda.h>
#include <net/irda/timer.h>
#include <net/irda/qos.h>
#include <net/irda/irlap.h>
#include <net/irda/iriap.h>
#include <net/irda/irlmp.h>
#include <net/irda/irlmp_frame.h>

#include <asm/unaligned.h>

static __u8 irlmp_find_free_slsap(void);
static int irlmp_slsap_inuse(__u8 slsap_sel);

/* Master structure */
struct irlmp_cb *irlmp = NULL;

/* These can be altered by the sysctl interface */
int  sysctl_discovery         = 0;
int  sysctl_discovery_timeout = 3; /* 3 seconds by default */
int  sysctl_discovery_slots   = 6; /* 6 slots by default */
int  sysctl_lap_keepalive_time = LM_IDLE_TIMEOUT * 1000 / HZ;
char sysctl_devname[65];

const char *irlmp_reasons[] = {
        "ERROR, NOT USED",
        "LM_USER_REQUEST",
        "LM_LAP_DISCONNECT",
        "LM_CONNECT_FAILURE",
        "LM_LAP_RESET",
        "LM_INIT_DISCONNECT",
        "ERROR, NOT USED",
};

/*
 * Function irlmp_init (void)
 *
 *    Create (allocate) the main IrLMP structure
 *
 */
int __init irlmp_init(void)
{
        IRDA_DEBUG(1, "%s()\n", __func__);
        /* Initialize the irlmp structure. */
        irlmp = kzalloc( sizeof(struct irlmp_cb), GFP_KERNEL);
        if (irlmp == NULL)
                return -ENOMEM;

        irlmp->magic = LMP_MAGIC;

        irlmp->clients = hashbin_new(HB_LOCK);
        irlmp->services = hashbin_new(HB_LOCK);
        irlmp->links = hashbin_new(HB_LOCK);
        irlmp->unconnected_lsaps = hashbin_new(HB_LOCK);
        irlmp->cachelog = hashbin_new(HB_NOLOCK);

        if ((irlmp->clients == NULL) ||
            (irlmp->services == NULL) ||
            (irlmp->links == NULL) ||
            (irlmp->unconnected_lsaps == NULL) ||
            (irlmp->cachelog == NULL)) {
                return -ENOMEM;
        }

        spin_lock_init(&irlmp->cachelog->hb_spinlock);

        irlmp->last_lsap_sel = 0x0f; /* Reserved 0x00-0x0f */
        strcpy(sysctl_devname, "Linux");

        init_timer(&irlmp->discovery_timer);

        /* Do discovery every 3 seconds, conditionally */
        if (sysctl_discovery)
                irlmp_start_discovery_timer(irlmp,
                                            sysctl_discovery_timeout*HZ);

        return 0;
}

/*
 * Function irlmp_cleanup (void)
 *
 *    Remove IrLMP layer
 *
 */
void irlmp_cleanup(void)
{
        /* Check for main structure */
        IRDA_ASSERT(irlmp != NULL, return;);
        IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return;);

        del_timer(&irlmp->discovery_timer);

        hashbin_delete(irlmp->links, (FREE_FUNC) kfree);
        hashbin_delete(irlmp->unconnected_lsaps, (FREE_FUNC) kfree);
        hashbin_delete(irlmp->clients, (FREE_FUNC) kfree);
        hashbin_delete(irlmp->services, (FREE_FUNC) kfree);
        hashbin_delete(irlmp->cachelog, (FREE_FUNC) kfree);

        /* De-allocate main structure */
        kfree(irlmp);
        irlmp = NULL;
}

/*
 * Function irlmp_open_lsap (slsap, notify)
 *
 *   Register with IrLMP and create a local LSAP,
 *   returns handle to LSAP.
 */
struct lsap_cb *irlmp_open_lsap(__u8 slsap_sel, notify_t *notify, __u8 pid)
{
        struct lsap_cb *self;

        IRDA_ASSERT(notify != NULL, return NULL;);
        IRDA_ASSERT(irlmp != NULL, return NULL;);
        IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return NULL;);
        IRDA_ASSERT(notify->instance != NULL, return NULL;);

        /*  Does the client care which Source LSAP selector it gets?  */
        if (slsap_sel == LSAP_ANY) {
                slsap_sel = irlmp_find_free_slsap();
                if (!slsap_sel)
                        return NULL;
        } else if (irlmp_slsap_inuse(slsap_sel))
                return NULL;

        /* Allocate new instance of a LSAP connection */
        self = kzalloc(sizeof(struct lsap_cb), GFP_ATOMIC);
        if (self == NULL) {
                IRDA_ERROR("%s: can't allocate memory\n", __func__);
                return NULL;
        }

        self->magic = LMP_LSAP_MAGIC;
        self->slsap_sel = slsap_sel;

        /* Fix connectionless LSAP's */
        if (slsap_sel == LSAP_CONNLESS) {
#ifdef CONFIG_IRDA_ULTRA
                self->dlsap_sel = LSAP_CONNLESS;
                self->pid = pid;
#endif /* CONFIG_IRDA_ULTRA */
        } else
                self->dlsap_sel = LSAP_ANY;
        /* self->connected = FALSE; -> already NULL via memset() */

        init_timer(&self->watchdog_timer);

        self->notify = *notify;

        self->lsap_state = LSAP_DISCONNECTED;

        /* Insert into queue of unconnected LSAPs */
        hashbin_insert(irlmp->unconnected_lsaps, (irda_queue_t *) self,
                       (long) self, NULL);

        return self;
}
EXPORT_SYMBOL(irlmp_open_lsap);

/*
 * Function __irlmp_close_lsap (self)
 *
 *    Remove an instance of LSAP
 */
static void __irlmp_close_lsap(struct lsap_cb *self)
{
        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);

        /*
         *  Set some of the variables to preset values
         */
        self->magic = 0;
        del_timer(&self->watchdog_timer); /* Important! */

        if (self->conn_skb)
                dev_kfree_skb(self->conn_skb);

        kfree(self);
}

/*
 * Function irlmp_close_lsap (self)
 *
 *    Close and remove LSAP
 *
 */
void irlmp_close_lsap(struct lsap_cb *self)
{
        struct lap_cb *lap;
        struct lsap_cb *lsap = NULL;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);

        /*
         *  Find out if we should remove this LSAP from a link or from the
         *  list of unconnected lsaps (not associated with a link)
         */
        lap = self->lap;
        if (lap) {
                IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, return;);
                /* We might close a LSAP before it has completed the
                 * connection setup. In those case, higher layers won't
                 * send a proper disconnect request. Harmless, except
                 * that we will forget to close LAP... - Jean II */
                if(self->lsap_state != LSAP_DISCONNECTED) {
                        self->lsap_state = LSAP_DISCONNECTED;
                        irlmp_do_lap_event(self->lap,
                                           LM_LAP_DISCONNECT_REQUEST, NULL);
                }
                /* Now, remove from the link */
                lsap = hashbin_remove(lap->lsaps, (long) self, NULL);
#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
                lap->cache.valid = FALSE;
#endif
        }
        self->lap = NULL;
        /* Check if we found the LSAP! If not then try the unconnected lsaps */
        if (!lsap) {
                lsap = hashbin_remove(irlmp->unconnected_lsaps, (long) self,
                                      NULL);
        }
        if (!lsap) {
                IRDA_DEBUG(0,
                     "%s(), Looks like somebody has removed me already!\n",
                           __func__);
                return;
        }
        __irlmp_close_lsap(self);
}
EXPORT_SYMBOL(irlmp_close_lsap);

/*
 * Function irlmp_register_irlap (saddr, notify)
 *
 *    Register IrLAP layer with IrLMP. There is possible to have multiple
 *    instances of the IrLAP layer, each connected to different IrDA ports
 *
 */
void irlmp_register_link(struct irlap_cb *irlap, __u32 saddr, notify_t *notify)
{
        struct lap_cb *lap;

        IRDA_ASSERT(irlmp != NULL, return;);
        IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return;);
        IRDA_ASSERT(notify != NULL, return;);

        /*
         *  Allocate new instance of a LSAP connection
         */
        lap = kzalloc(sizeof(struct lap_cb), GFP_KERNEL);
        if (lap == NULL) {
                IRDA_ERROR("%s: unable to kmalloc\n", __func__);
                return;
        }

        lap->irlap = irlap;
        lap->magic = LMP_LAP_MAGIC;
        lap->saddr = saddr;
        lap->daddr = DEV_ADDR_ANY;
#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
        lap->cache.valid = FALSE;
#endif
        lap->lsaps = hashbin_new(HB_LOCK);
        if (lap->lsaps == NULL) {
                IRDA_WARNING("%s(), unable to kmalloc lsaps\n", __func__);
                kfree(lap);
                return;
        }

        lap->lap_state = LAP_STANDBY;

        init_timer(&lap->idle_timer);

        /*
         *  Insert into queue of LMP links
         */
        hashbin_insert(irlmp->links, (irda_queue_t *) lap, lap->saddr, NULL);

        /*
         *  We set only this variable so IrLAP can tell us on which link the
         *  different events happened on
         */
        irda_notify_init(notify);
        notify->instance = lap;
}

/*
 * Function irlmp_unregister_irlap (saddr)
 *
 *    IrLAP layer has been removed!
 *
 */
void irlmp_unregister_link(__u32 saddr)
{
        struct lap_cb *link;

        IRDA_DEBUG(4, "%s()\n", __func__);

        /* We must remove ourselves from the hashbin *first*. This ensure
         * that no more LSAPs will be open on this link and no discovery
         * will be triggered anymore. Jean II */
        link = hashbin_remove(irlmp->links, saddr, NULL);
        if (link) {
                IRDA_ASSERT(link->magic == LMP_LAP_MAGIC, return;);

                /* Kill all the LSAPs on this link. Jean II */
                link->reason = LAP_DISC_INDICATION;
                link->daddr = DEV_ADDR_ANY;
                irlmp_do_lap_event(link, LM_LAP_DISCONNECT_INDICATION, NULL);

                /* Remove all discoveries discovered at this link */
                irlmp_expire_discoveries(irlmp->cachelog, link->saddr, TRUE);

                /* Final cleanup */
                del_timer(&link->idle_timer);
                link->magic = 0;
                hashbin_delete(link->lsaps, (FREE_FUNC) __irlmp_close_lsap);
                kfree(link);
        }
}

/*
 * Function irlmp_connect_request (handle, dlsap, userdata)
 *
 *    Connect with a peer LSAP
 *
 */
int irlmp_connect_request(struct lsap_cb *self, __u8 dlsap_sel,
                          __u32 saddr, __u32 daddr,
                          struct qos_info *qos, struct sk_buff *userdata)
{
        struct sk_buff *tx_skb = userdata;
        struct lap_cb *lap;
        struct lsap_cb *lsap;
        int ret;

        IRDA_ASSERT(self != NULL, return -EBADR;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -EBADR;);

        IRDA_DEBUG(2,
              "%s(), slsap_sel=%02x, dlsap_sel=%02x, saddr=%08x, daddr=%08x\n",
              __func__, self->slsap_sel, dlsap_sel, saddr, daddr);

        if (test_bit(0, &self->connected)) {
                ret = -EISCONN;
                goto err;
        }

        /* Client must supply destination device address */
        if (!daddr) {
                ret = -EINVAL;
                goto err;
        }

        /* Any userdata? */
        if (tx_skb == NULL) {
                tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
                if (!tx_skb)
                        return -ENOMEM;

                skb_reserve(tx_skb, LMP_MAX_HEADER);
        }

        /* Make room for MUX control header (3 bytes) */
        IRDA_ASSERT(skb_headroom(tx_skb) >= LMP_CONTROL_HEADER, return -1;);
        skb_push(tx_skb, LMP_CONTROL_HEADER);

        self->dlsap_sel = dlsap_sel;

        /*
         * Find the link to where we should try to connect since there may
         * be more than one IrDA port on this machine. If the client has
         * passed us the saddr (and already knows which link to use), then
         * we use that to find the link, if not then we have to look in the
         * discovery log and check if any of the links has discovered a
         * device with the given daddr
         */
        if ((!saddr) || (saddr == DEV_ADDR_ANY)) {
                discovery_t *discovery;
                unsigned long flags;

                spin_lock_irqsave(&irlmp->cachelog->hb_spinlock, flags);
                if (daddr != DEV_ADDR_ANY)
                        discovery = hashbin_find(irlmp->cachelog, daddr, NULL);
                else {
                        IRDA_DEBUG(2, "%s(), no daddr\n", __func__);
                        discovery = (discovery_t *)
                                hashbin_get_first(irlmp->cachelog);
                }

                if (discovery) {
                        saddr = discovery->data.saddr;
                        daddr = discovery->data.daddr;
                }
                spin_unlock_irqrestore(&irlmp->cachelog->hb_spinlock, flags);
        }
        lap = hashbin_lock_find(irlmp->links, saddr, NULL);
        if (lap == NULL) {
                IRDA_DEBUG(1, "%s(), Unable to find a usable link!\n", __func__);
                ret = -EHOSTUNREACH;
                goto err;
        }

        /* Check if LAP is disconnected or already connected */
        if (lap->daddr == DEV_ADDR_ANY)
                lap->daddr = daddr;
        else if (lap->daddr != daddr) {
                /* Check if some LSAPs are active on this LAP */
                if (HASHBIN_GET_SIZE(lap->lsaps) == 0) {
                        /* No active connection, but LAP hasn't been
                         * disconnected yet (waiting for timeout in LAP).
                         * Maybe we could give LAP a bit of help in this case.
                         */
                        IRDA_DEBUG(0, "%s(), sorry, but I'm waiting for LAP to timeout!\n", __func__);
                        ret = -EAGAIN;
                        goto err;
                }

                /* LAP is already connected to a different node, and LAP
                 * can only talk to one node at a time */
                IRDA_DEBUG(0, "%s(), sorry, but link is busy!\n", __func__);
                ret = -EBUSY;
                goto err;
        }

        self->lap = lap;

        /*
         *  Remove LSAP from list of unconnected LSAPs and insert it into the
         *  list of connected LSAPs for the particular link
         */
        lsap = hashbin_remove(irlmp->unconnected_lsaps, (long) self, NULL);

        IRDA_ASSERT(lsap != NULL, return -1;);
        IRDA_ASSERT(lsap->magic == LMP_LSAP_MAGIC, return -1;);
        IRDA_ASSERT(lsap->lap != NULL, return -1;);
        IRDA_ASSERT(lsap->lap->magic == LMP_LAP_MAGIC, return -1;);

        hashbin_insert(self->lap->lsaps, (irda_queue_t *) self, (long) self,
                       NULL);

        set_bit(0, &self->connected);   /* TRUE */

        /*
         *  User supplied qos specifications?
         */
        if (qos)
                self->qos = *qos;

        irlmp_do_lsap_event(self, LM_CONNECT_REQUEST, tx_skb);

        /* Drop reference count - see irlap_data_request(). */
        dev_kfree_skb(tx_skb);

        return 0;

err:
        /* Cleanup */
        if(tx_skb)
                dev_kfree_skb(tx_skb);
        return ret;
}
EXPORT_SYMBOL(irlmp_connect_request);

/*
 * Function irlmp_connect_indication (self)
 *
 *    Incoming connection
 *
 */
void irlmp_connect_indication(struct lsap_cb *self, struct sk_buff *skb)
{
        int max_seg_size;
        int lap_header_size;
        int max_header_size;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);
        IRDA_ASSERT(skb != NULL, return;);
        IRDA_ASSERT(self->lap != NULL, return;);

        IRDA_DEBUG(2, "%s(), slsap_sel=%02x, dlsap_sel=%02x\n",
                   __func__, self->slsap_sel, self->dlsap_sel);

        /* Note : self->lap is set in irlmp_link_data_indication(),
         * (case CONNECT_CMD:) because we have no way to set it here.
         * Similarly, self->dlsap_sel is usually set in irlmp_find_lsap().
         * Jean II */

        self->qos = *self->lap->qos;

        max_seg_size = self->lap->qos->data_size.value-LMP_HEADER;
        lap_header_size = IRLAP_GET_HEADER_SIZE(self->lap->irlap);
        max_header_size = LMP_HEADER + lap_header_size;

        /* Hide LMP_CONTROL_HEADER header from layer above */
        skb_pull(skb, LMP_CONTROL_HEADER);

        if (self->notify.connect_indication) {
                /* Don't forget to refcount it - see irlap_driver_rcv(). */
                skb_get(skb);
                self->notify.connect_indication(self->notify.instance, self,
                                                &self->qos, max_seg_size,
                                                max_header_size, skb);
        }
}

/*
 * Function irlmp_connect_response (handle, userdata)
 *
 *    Service user is accepting connection
 *
 */
int irlmp_connect_response(struct lsap_cb *self, struct sk_buff *userdata)
{
        IRDA_ASSERT(self != NULL, return -1;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -1;);
        IRDA_ASSERT(userdata != NULL, return -1;);

        /* We set the connected bit and move the lsap to the connected list
         * in the state machine itself. Jean II */

        IRDA_DEBUG(2, "%s(), slsap_sel=%02x, dlsap_sel=%02x\n",
                   __func__, self->slsap_sel, self->dlsap_sel);

        /* Make room for MUX control header (3 bytes) */
        IRDA_ASSERT(skb_headroom(userdata) >= LMP_CONTROL_HEADER, return -1;);
        skb_push(userdata, LMP_CONTROL_HEADER);

        irlmp_do_lsap_event(self, LM_CONNECT_RESPONSE, userdata);

        /* Drop reference count - see irlap_data_request(). */
        dev_kfree_skb(userdata);

        return 0;
}
EXPORT_SYMBOL(irlmp_connect_response);

/*
 * Function irlmp_connect_confirm (handle, skb)
 *
 *    LSAP connection confirmed peer device!
 */
void irlmp_connect_confirm(struct lsap_cb *self, struct sk_buff *skb)
{
        int max_header_size;
        int lap_header_size;
        int max_seg_size;

        IRDA_DEBUG(3, "%s()\n", __func__);

        IRDA_ASSERT(skb != NULL, return;);
        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);
        IRDA_ASSERT(self->lap != NULL, return;);

        self->qos = *self->lap->qos;

        max_seg_size    = self->lap->qos->data_size.value-LMP_HEADER;
        lap_header_size = IRLAP_GET_HEADER_SIZE(self->lap->irlap);
        max_header_size = LMP_HEADER + lap_header_size;

        IRDA_DEBUG(2, "%s(), max_header_size=%d\n",
                   __func__, max_header_size);

        /* Hide LMP_CONTROL_HEADER header from layer above */
        skb_pull(skb, LMP_CONTROL_HEADER);

        if (self->notify.connect_confirm) {
                /* Don't forget to refcount it - see irlap_driver_rcv() */
                skb_get(skb);
                self->notify.connect_confirm(self->notify.instance, self,
                                             &self->qos, max_seg_size,
                                             max_header_size, skb);
        }
}

/*
 * Function irlmp_dup (orig, instance)
 *
 *    Duplicate LSAP, can be used by servers to confirm a connection on a
 *    new LSAP so it can keep listening on the old one.
 *
 */
struct lsap_cb *irlmp_dup(struct lsap_cb *orig, void *instance)
{
        struct lsap_cb *new;
        unsigned long flags;

        IRDA_DEBUG(1, "%s()\n", __func__);

        spin_lock_irqsave(&irlmp->unconnected_lsaps->hb_spinlock, flags);

        /* Only allowed to duplicate unconnected LSAP's, and only LSAPs
         * that have received a connect indication. Jean II */
        if ((!hashbin_find(irlmp->unconnected_lsaps, (long) orig, NULL)) ||
            (orig->lap == NULL)) {
                IRDA_DEBUG(0, "%s(), invalid LSAP (wrong state)\n",
                           __func__);
                spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock,
                                       flags);
                return NULL;
        }

        /* Allocate a new instance */
        new = kmemdup(orig, sizeof(*new), GFP_ATOMIC);
        if (!new)  {
                IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
                spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock,
                                       flags);
                return NULL;
        }
        /* new->lap = orig->lap; => done in the memcpy() */
        /* new->slsap_sel = orig->slsap_sel; => done in the memcpy() */
        new->conn_skb = NULL;

        spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);

        /* Not everything is the same */
        new->notify.instance = instance;

        init_timer(&new->watchdog_timer);

        hashbin_insert(irlmp->unconnected_lsaps, (irda_queue_t *) new,
                       (long) new, NULL);

#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
        /* Make sure that we invalidate the LSAP cache */
        new->lap->cache.valid = FALSE;
#endif /* CONFIG_IRDA_CACHE_LAST_LSAP */

        return new;
}

/*
 * Function irlmp_disconnect_request (handle, userdata)
 *
 *    The service user is requesting disconnection, this will not remove the
 *    LSAP, but only mark it as disconnected
 */
int irlmp_disconnect_request(struct lsap_cb *self, struct sk_buff *userdata)
{
        struct lsap_cb *lsap;

        IRDA_ASSERT(self != NULL, return -1;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -1;);
        IRDA_ASSERT(userdata != NULL, return -1;);

        /* Already disconnected ?
         * There is a race condition between irlmp_disconnect_indication()
         * and us that might mess up the hashbins below. This fixes it.
         * Jean II */
        if (! test_and_clear_bit(0, &self->connected)) {
                IRDA_DEBUG(0, "%s(), already disconnected!\n", __func__);
                dev_kfree_skb(userdata);
                return -1;
        }

        skb_push(userdata, LMP_CONTROL_HEADER);

        /*
         *  Do the event before the other stuff since we must know
         *  which lap layer that the frame should be transmitted on
         */
        irlmp_do_lsap_event(self, LM_DISCONNECT_REQUEST, userdata);

        /* Drop reference count - see irlap_data_request(). */
        dev_kfree_skb(userdata);

        /*
         *  Remove LSAP from list of connected LSAPs for the particular link
         *  and insert it into the list of unconnected LSAPs
         */
        IRDA_ASSERT(self->lap != NULL, return -1;);
        IRDA_ASSERT(self->lap->magic == LMP_LAP_MAGIC, return -1;);
        IRDA_ASSERT(self->lap->lsaps != NULL, return -1;);

        lsap = hashbin_remove(self->lap->lsaps, (long) self, NULL);
#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
        self->lap->cache.valid = FALSE;
#endif

        IRDA_ASSERT(lsap != NULL, return -1;);
        IRDA_ASSERT(lsap->magic == LMP_LSAP_MAGIC, return -1;);
        IRDA_ASSERT(lsap == self, return -1;);

        hashbin_insert(irlmp->unconnected_lsaps, (irda_queue_t *) self,
                       (long) self, NULL);

        /* Reset some values */
        self->dlsap_sel = LSAP_ANY;
        self->lap = NULL;

        return 0;
}
EXPORT_SYMBOL(irlmp_disconnect_request);

/*
 * Function irlmp_disconnect_indication (reason, userdata)
 *
 *    LSAP is being closed!
 */
void irlmp_disconnect_indication(struct lsap_cb *self, LM_REASON reason,
                                 struct sk_buff *skb)
{
        struct lsap_cb *lsap;

        IRDA_DEBUG(1, "%s(), reason=%s\n", __func__, irlmp_reasons[reason]);
        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);

        IRDA_DEBUG(3, "%s(), slsap_sel=%02x, dlsap_sel=%02x\n",
                   __func__, self->slsap_sel, self->dlsap_sel);

        /* Already disconnected ?
         * There is a race condition between irlmp_disconnect_request()
         * and us that might mess up the hashbins below. This fixes it.
         * Jean II */
        if (! test_and_clear_bit(0, &self->connected)) {
                IRDA_DEBUG(0, "%s(), already disconnected!\n", __func__);
                return;
        }

        /*
         *  Remove association between this LSAP and the link it used
         */
        IRDA_ASSERT(self->lap != NULL, return;);
        IRDA_ASSERT(self->lap->lsaps != NULL, return;);

        lsap = hashbin_remove(self->lap->lsaps, (long) self, NULL);
#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
        self->lap->cache.valid = FALSE;
#endif

        IRDA_ASSERT(lsap != NULL, return;);
        IRDA_ASSERT(lsap == self, return;);
        hashbin_insert(irlmp->unconnected_lsaps, (irda_queue_t *) lsap,
                       (long) lsap, NULL);

        self->dlsap_sel = LSAP_ANY;
        self->lap = NULL;

        /*
         *  Inform service user
         */
        if (self->notify.disconnect_indication) {
                /* Don't forget to refcount it - see irlap_driver_rcv(). */
                if(skb)
                        skb_get(skb);
                self->notify.disconnect_indication(self->notify.instance,
                                                   self, reason, skb);
        } else {
                IRDA_DEBUG(0, "%s(), no handler\n", __func__);
        }
}

/*
 * Function irlmp_do_expiry (void)
 *
 *    Do a cleanup of the discovery log (remove old entries)
 *
 * Note : separate from irlmp_do_discovery() so that we can handle
 * passive discovery properly.
 */
void irlmp_do_expiry(void)
{
        struct lap_cb *lap;

        /*
         * Expire discovery on all links which are *not* connected.
         * On links which are connected, we can't do discovery
         * anymore and can't refresh the log, so we freeze the
         * discovery log to keep info about the device we are
         * connected to.
         * This info is mandatory if we want irlmp_connect_request()
         * to work properly. - Jean II
         */
        lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
        while (lap != NULL) {
                IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, return;);

                if (lap->lap_state == LAP_STANDBY) {
                        /* Expire discoveries discovered on this link */
                        irlmp_expire_discoveries(irlmp->cachelog, lap->saddr,
                                                 FALSE);
                }
                lap = (struct lap_cb *) hashbin_get_next(irlmp->links);
        }
}

/*
 * Function irlmp_do_discovery (nslots)
 *
 *    Do some discovery on all links
 *
 * Note : log expiry is done above.
 */
void irlmp_do_discovery(int nslots)
{
        struct lap_cb *lap;
        __u16 *data_hintsp;

        /* Make sure the value is sane */
        if ((nslots != 1) && (nslots != 6) && (nslots != 8) && (nslots != 16)){
                IRDA_WARNING("%s: invalid value for number of slots!\n",
                             __func__);
                nslots = sysctl_discovery_slots = 8;
        }

        /* Construct new discovery info to be used by IrLAP, */
        data_hintsp = (__u16 *) irlmp->discovery_cmd.data.hints;
        put_unaligned(irlmp->hints.word, data_hintsp);

        /*
         *  Set character set for device name (we use ASCII), and
         *  copy device name. Remember to make room for a \0 at the
         *  end
         */
        irlmp->discovery_cmd.data.charset = CS_ASCII;
        strncpy(irlmp->discovery_cmd.data.info, sysctl_devname,
                NICKNAME_MAX_LEN);
        irlmp->discovery_cmd.name_len = strlen(irlmp->discovery_cmd.data.info);
        irlmp->discovery_cmd.nslots = nslots;

        /*
         * Try to send discovery packets on all links
         */
        lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
        while (lap != NULL) {
                IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, return;);

                if (lap->lap_state == LAP_STANDBY) {
                        /* Try to discover */
                        irlmp_do_lap_event(lap, LM_LAP_DISCOVERY_REQUEST,
                                           NULL);
                }
                lap = (struct lap_cb *) hashbin_get_next(irlmp->links);
        }
}

/*
 * Function irlmp_discovery_request (nslots)
 *
 *    Do a discovery of devices in front of the computer
 *
 * If the caller has registered a client discovery callback, this
 * allow him to receive the full content of the discovery log through
 * this callback (as normally he will receive only new discoveries).
 */
void irlmp_discovery_request(int nslots)
{
        /* Return current cached discovery log (in full) */
        irlmp_discovery_confirm(irlmp->cachelog, DISCOVERY_LOG);

        /*
         * Start a single discovery operation if discovery is not already
         * running
         */
        if (!sysctl_discovery) {
                /* Check if user wants to override the default */
                if (nslots == DISCOVERY_DEFAULT_SLOTS)
                        nslots = sysctl_discovery_slots;

                irlmp_do_discovery(nslots);
                /* Note : we never do expiry here. Expiry will run on the
                 * discovery timer regardless of the state of sysctl_discovery
                 * Jean II */
        }
}
EXPORT_SYMBOL(irlmp_discovery_request);

/*
 * Function irlmp_get_discoveries (pn, mask, slots)
 *
 *    Return the current discovery log
 *
 * If discovery is not enabled, you should call this function again
 * after 1 or 2 seconds (i.e. after discovery has been done).
 */
struct irda_device_info *irlmp_get_discoveries(int *pn, __u16 mask, int nslots)
{
        /* If discovery is not enabled, it's likely that the discovery log
         * will be empty. So, we trigger a single discovery, so that next
         * time the user call us there might be some results in the log.
         * Jean II
         */
        if (!sysctl_discovery) {
                /* Check if user wants to override the default */
                if (nslots == DISCOVERY_DEFAULT_SLOTS)
                        nslots = sysctl_discovery_slots;

                /* Start discovery - will complete sometime later */
                irlmp_do_discovery(nslots);
                /* Note : we never do expiry here. Expiry will run on the
                 * discovery timer regardless of the state of sysctl_discovery
                 * Jean II */
        }

        /* Return current cached discovery log */
        return(irlmp_copy_discoveries(irlmp->cachelog, pn, mask, TRUE));
}
EXPORT_SYMBOL(irlmp_get_discoveries);

/*
 * Function irlmp_notify_client (log)
 *
 *    Notify all about discovered devices
 *
 * Clients registered with IrLMP are :
 *      o IrComm
 *      o IrLAN
 *      o Any socket (in any state - ouch, that may be a lot !)
 * The client may have defined a callback to be notified in case of
 * partial/selective discovery based on the hints that it passed to IrLMP.
 */
static inline void
irlmp_notify_client(irlmp_client_t *client,
                    hashbin_t *log, DISCOVERY_MODE mode)
{
        discinfo_t *discoveries;        /* Copy of the discovery log */
        int     number;                 /* Number of nodes in the log */
        int     i;

        IRDA_DEBUG(3, "%s()\n", __func__);

        /* Check if client wants or not partial/selective log (optimisation) */
        if (!client->disco_callback)
                return;

        /*
         * Locking notes :
         * the old code was manipulating the log directly, which was
         * very racy. Now, we use copy_discoveries, that protects
         * itself while dumping the log for us.
         * The overhead of the copy is compensated by the fact that
         * we only pass new discoveries in normal mode and don't
         * pass the same old entry every 3s to the caller as we used
         * to do (virtual function calling is expensive).
         * Jean II
         */

        /*
         * Now, check all discovered devices (if any), and notify client
         * only about the services that the client is interested in
         * We also notify only about the new devices unless the caller
         * explicitly request a dump of the log. Jean II
         */
        discoveries = irlmp_copy_discoveries(log, &number,
                                             client->hint_mask.word,
                                             (mode == DISCOVERY_LOG));
        /* Check if the we got some results */
        if (discoveries == NULL)
                return; /* No nodes discovered */

        /* Pass all entries to the listener */
        for(i = 0; i < number; i++)
                client->disco_callback(&(discoveries[i]), mode, client->priv);

        /* Free up our buffer */
        kfree(discoveries);
}

/*
 * Function irlmp_discovery_confirm ( self, log)
 *
 *    Some device(s) answered to our discovery request! Check to see which
 *    device it is, and give indication to the client(s)
 *
 */
void irlmp_discovery_confirm(hashbin_t *log, DISCOVERY_MODE mode)
{
        irlmp_client_t *client;
        irlmp_client_t *client_next;

        IRDA_DEBUG(3, "%s()\n", __func__);

        IRDA_ASSERT(log != NULL, return;);

        if (!(HASHBIN_GET_SIZE(log)))
                return;

        /* For each client - notify callback may touch client list */
        client = (irlmp_client_t *) hashbin_get_first(irlmp->clients);
        while (NULL != hashbin_find_next(irlmp->clients, (long) client, NULL,
                                         (void *) &client_next) ) {
                /* Check if we should notify client */
                irlmp_notify_client(client, log, mode);

                client = client_next;
        }
}

/*
 * Function irlmp_discovery_expiry (expiry)
 *
 *      This device is no longer been discovered, and therefore it is being
 *      purged from the discovery log. Inform all clients who have
 *      registered for this event...
 *
 *      Note : called exclusively from discovery.c
 *      Note : this is no longer called under discovery spinlock, so the
 *              client can do whatever he wants in the callback.
 */
void irlmp_discovery_expiry(discinfo_t *expiries, int number)
{
        irlmp_client_t *client;
        irlmp_client_t *client_next;
        int             i;

        IRDA_DEBUG(3, "%s()\n", __func__);

        IRDA_ASSERT(expiries != NULL, return;);

        /* For each client - notify callback may touch client list */
        client = (irlmp_client_t *) hashbin_get_first(irlmp->clients);
        while (NULL != hashbin_find_next(irlmp->clients, (long) client, NULL,
                                         (void *) &client_next) ) {

                /* Pass all entries to the listener */
                for(i = 0; i < number; i++) {
                        /* Check if we should notify client */
                        if ((client->expir_callback) &&
                            (client->hint_mask.word &
                             get_unaligned((__u16 *)expiries[i].hints)
                             & 0x7f7f) )
                                client->expir_callback(&(expiries[i]),
                                                       EXPIRY_TIMEOUT,
                                                       client->priv);
                }

                /* Next client */
                client = client_next;
        }
}

/*
 * Function irlmp_get_discovery_response ()
 *
 *    Used by IrLAP to get the discovery info it needs when answering
 *    discovery requests by other devices.
 */
discovery_t *irlmp_get_discovery_response(void)
{
        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(irlmp != NULL, return NULL;);

        put_unaligned(irlmp->hints.word, (__u16 *)irlmp->discovery_rsp.data.hints);

        /*
         *  Set character set for device name (we use ASCII), and
         *  copy device name. Remember to make room for a \0 at the
         *  end
         */
        irlmp->discovery_rsp.data.charset = CS_ASCII;

        strncpy(irlmp->discovery_rsp.data.info, sysctl_devname,
                NICKNAME_MAX_LEN);
        irlmp->discovery_rsp.name_len = strlen(irlmp->discovery_rsp.data.info);

        return &irlmp->discovery_rsp;
}

/*
 * Function irlmp_data_request (self, skb)
 *
 *    Send some data to peer device
 *
 * Note on skb management :
 * After calling the lower layers of the IrDA stack, we always
 * kfree() the skb, which drop the reference count (and potentially
 * destroy it).
 * IrLMP and IrLAP may queue the packet, and in those cases will need
 * to use skb_get() to keep it around.
 * Jean II
 */
int irlmp_data_request(struct lsap_cb *self, struct sk_buff *userdata)
{
        int     ret;

        IRDA_ASSERT(self != NULL, return -1;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -1;);

        /* Make room for MUX header */
        IRDA_ASSERT(skb_headroom(userdata) >= LMP_HEADER, return -1;);
        skb_push(userdata, LMP_HEADER);

        ret = irlmp_do_lsap_event(self, LM_DATA_REQUEST, userdata);

        /* Drop reference count - see irlap_data_request(). */
        dev_kfree_skb(userdata);

        return ret;
}
EXPORT_SYMBOL(irlmp_data_request);

/*
 * Function irlmp_data_indication (handle, skb)
 *
 *    Got data from LAP layer so pass it up to upper layer
 *
 */
void irlmp_data_indication(struct lsap_cb *self, struct sk_buff *skb)
{
        /* Hide LMP header from layer above */
        skb_pull(skb, LMP_HEADER);

        if (self->notify.data_indication) {
                /* Don't forget to refcount it - see irlap_driver_rcv(). */
                skb_get(skb);
                self->notify.data_indication(self->notify.instance, self, skb);
        }
}

/*
 * Function irlmp_udata_request (self, skb)
 */
int irlmp_udata_request(struct lsap_cb *self, struct sk_buff *userdata)
{
        int     ret;

        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(userdata != NULL, return -1;);

        /* Make room for MUX header */
        IRDA_ASSERT(skb_headroom(userdata) >= LMP_HEADER, return -1;);
        skb_push(userdata, LMP_HEADER);

        ret = irlmp_do_lsap_event(self, LM_UDATA_REQUEST, userdata);

        /* Drop reference count - see irlap_data_request(). */
        dev_kfree_skb(userdata);

        return ret;
}

/*
 * Function irlmp_udata_indication (self, skb)
 *
 *    Send unreliable data (but still within the connection)
 *
 */
void irlmp_udata_indication(struct lsap_cb *self, struct sk_buff *skb)
{
        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);
        IRDA_ASSERT(skb != NULL, return;);

        /* Hide LMP header from layer above */
        skb_pull(skb, LMP_HEADER);

        if (self->notify.udata_indication) {
                /* Don't forget to refcount it - see irlap_driver_rcv(). */
                skb_get(skb);
                self->notify.udata_indication(self->notify.instance, self,
                                              skb);
        }
}

/*
 * Function irlmp_connless_data_request (self, skb)
 */
#ifdef CONFIG_IRDA_ULTRA
int irlmp_connless_data_request(struct lsap_cb *self, struct sk_buff *userdata,
                                __u8 pid)
{
        struct sk_buff *clone_skb;
        struct lap_cb *lap;

        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(userdata != NULL, return -1;);

        /* Make room for MUX and PID header */
        IRDA_ASSERT(skb_headroom(userdata) >= LMP_HEADER+LMP_PID_HEADER,
                    return -1;);

        /* Insert protocol identifier */
        skb_push(userdata, LMP_PID_HEADER);
        if(self != NULL)
          userdata->data[0] = self->pid;
        else
          userdata->data[0] = pid;

        /* Connectionless sockets must use 0x70 */
        skb_push(userdata, LMP_HEADER);
        userdata->data[0] = userdata->data[1] = LSAP_CONNLESS;

        /* Try to send Connectionless  packets out on all links */
        lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
        while (lap != NULL) {
                IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, return -1;);

                clone_skb = skb_clone(userdata, GFP_ATOMIC);
                if (!clone_skb) {
                        dev_kfree_skb(userdata);
                        return -ENOMEM;
                }

                irlap_unitdata_request(lap->irlap, clone_skb);
                /* irlap_unitdata_request() don't increase refcount,
                 * so no dev_kfree_skb() - Jean II */

                lap = (struct lap_cb *) hashbin_get_next(irlmp->links);
        }
        dev_kfree_skb(userdata);

        return 0;
}
#endif /* CONFIG_IRDA_ULTRA */

/*
 * Function irlmp_connless_data_indication (self, skb)
 *
 *    Receive unreliable data outside any connection. Mostly used by Ultra
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlmp_connless_data_indication(struct lsap_cb *self, struct sk_buff *skb)
{
        IRDA_DEBUG(4, "%s()\n", __func__);

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return;);
        IRDA_ASSERT(skb != NULL, return;);

        /* Hide LMP and PID header from layer above */
        skb_pull(skb, LMP_HEADER+LMP_PID_HEADER);

        if (self->notify.udata_indication) {
                /* Don't forget to refcount it - see irlap_driver_rcv(). */
                skb_get(skb);
                self->notify.udata_indication(self->notify.instance, self,
                                              skb);
        }
}
#endif /* CONFIG_IRDA_ULTRA */

/*
 * Propagate status indication from LAP to LSAPs (via LMP)
 * This don't trigger any change of state in lap_cb, lmp_cb or lsap_cb,
 * and the event is stateless, therefore we can bypass both state machines
 * and send the event direct to the LSAP user.
 * Jean II
 */
void irlmp_status_indication(struct lap_cb *self,
                             LINK_STATUS link, LOCK_STATUS lock)
{
        struct lsap_cb *next;
        struct lsap_cb *curr;

        /* Send status_indication to all LSAPs using this link */
        curr = (struct lsap_cb *) hashbin_get_first( self->lsaps);
        while (NULL != hashbin_find_next(self->lsaps, (long) curr, NULL,
                                         (void *) &next) ) {
                IRDA_ASSERT(curr->magic == LMP_LSAP_MAGIC, return;);
                /*
                 *  Inform service user if he has requested it
                 */
                if (curr->notify.status_indication != NULL)
                        curr->notify.status_indication(curr->notify.instance,
                                                       link, lock);
                else
                        IRDA_DEBUG(2, "%s(), no handler\n", __func__);

                curr = next;
        }
}

/*
 * Receive flow control indication from LAP.
 * LAP want us to send it one more frame. We implement a simple round
 * robin scheduler between the active sockets so that we get a bit of
 * fairness. Note that the round robin is far from perfect, but it's
 * better than nothing.
 * We then poll the selected socket so that we can do synchronous
 * refilling of IrLAP (which allow to minimise the number of buffers).
 * Jean II
 */
void irlmp_flow_indication(struct lap_cb *self, LOCAL_FLOW flow)
{
        struct lsap_cb *next;
        struct lsap_cb *curr;
        int     lsap_todo;

        IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
        IRDA_ASSERT(flow == FLOW_START, return;);

        /* Get the number of lsap. That's the only safe way to know
         * that we have looped around... - Jean II */
        lsap_todo = HASHBIN_GET_SIZE(self->lsaps);
        IRDA_DEBUG(4, "%s() : %d lsaps to scan\n", __func__, lsap_todo);

        /* Poll lsap in order until the queue is full or until we
         * tried them all.
         * Most often, the current LSAP will have something to send,
         * so we will go through this loop only once. - Jean II */
        while((lsap_todo--) &&
              (IRLAP_GET_TX_QUEUE_LEN(self->irlap) < LAP_HIGH_THRESHOLD)) {
                /* Try to find the next lsap we should poll. */
                next = self->flow_next;
                /* If we have no lsap, restart from first one */
                if(next == NULL)
                        next = (struct lsap_cb *) hashbin_get_first(self->lsaps);
                /* Verify current one and find the next one */
                curr = hashbin_find_next(self->lsaps, (long) next, NULL,
                                         (void *) &self->flow_next);
                /* Uh-oh... Paranoia */
                if(curr == NULL)
                        break;
                IRDA_DEBUG(4, "%s() : curr is %p, next was %p and is now %p, still %d to go - queue len = %d\n", __func__, curr, next, self->flow_next, lsap_todo, IRLAP_GET_TX_QUEUE_LEN(self->irlap));

                /* Inform lsap user that it can send one more packet. */
                if (curr->notify.flow_indication != NULL)
                        curr->notify.flow_indication(curr->notify.instance,
                                                     curr, flow);
                else
                        IRDA_DEBUG(1, "%s(), no handler\n", __func__);
        }
}

#if 0
/*
 * Function irlmp_hint_to_service (hint)
 *
 *    Returns a list of all servics contained in the given hint bits. This
 *    function assumes that the hint bits have the size of two bytes only
 */
__u8 *irlmp_hint_to_service(__u8 *hint)
{
        __u8 *service;
        int i = 0;

        /*
         * Allocate array to store services in. 16 entries should be safe
         * since we currently only support 2 hint bytes
         */
        service = kmalloc(16, GFP_ATOMIC);
        if (!service) {
                IRDA_DEBUG(1, "%s(), Unable to kmalloc!\n", __func__);
                return NULL;
        }

        if (!hint[0]) {
                IRDA_DEBUG(1, "<None>\n");
                kfree(service);
                return NULL;
        }
        if (hint[0] & HINT_PNP)
                IRDA_DEBUG(1, "PnP Compatible ");
        if (hint[0] & HINT_PDA)
                IRDA_DEBUG(1, "PDA/Palmtop ");
        if (hint[0] & HINT_COMPUTER)
                IRDA_DEBUG(1, "Computer ");
        if (hint[0] & HINT_PRINTER) {
                IRDA_DEBUG(1, "Printer ");
                service[i++] = S_PRINTER;
        }
        if (hint[0] & HINT_MODEM)
                IRDA_DEBUG(1, "Modem ");
        if (hint[0] & HINT_FAX)
                IRDA_DEBUG(1, "Fax ");
        if (hint[0] & HINT_LAN) {
                IRDA_DEBUG(1, "LAN Access ");
                service[i++] = S_LAN;
        }
        /*
         *  Test if extension byte exists. This byte will usually be
         *  there, but this is not really required by the standard.
         *  (IrLMP p. 29)
         */
        if (hint[0] & HINT_EXTENSION) {
                if (hint[1] & HINT_TELEPHONY) {
                        IRDA_DEBUG(1, "Telephony ");
                        service[i++] = S_TELEPHONY;
                } if (hint[1] & HINT_FILE_SERVER)
                        IRDA_DEBUG(1, "File Server ");

                if (hint[1] & HINT_COMM) {
                        IRDA_DEBUG(1, "IrCOMM ");
                        service[i++] = S_COMM;
                }
                if (hint[1] & HINT_OBEX) {
                        IRDA_DEBUG(1, "IrOBEX ");
                        service[i++] = S_OBEX;
                }
        }
        IRDA_DEBUG(1, "\n");

        /* So that client can be notified about any discovery */
        service[i++] = S_ANY;

        service[i] = S_END;

        return service;
}
#endif

static const __u16 service_hint_mapping[S_END][2] = {
        { HINT_PNP,             0 },                    /* S_PNP */
        { HINT_PDA,             0 },                    /* S_PDA */
        { HINT_COMPUTER,        0 },                    /* S_COMPUTER */
        { HINT_PRINTER,         0 },                    /* S_PRINTER */
        { HINT_MODEM,           0 },                    /* S_MODEM */
        { HINT_FAX,             0 },                    /* S_FAX */
        { HINT_LAN,             0 },                    /* S_LAN */
        { HINT_EXTENSION,       HINT_TELEPHONY },       /* S_TELEPHONY */
        { HINT_EXTENSION,       HINT_COMM },            /* S_COMM */
        { HINT_EXTENSION,       HINT_OBEX },            /* S_OBEX */
        { 0xFF,                 0xFF },                 /* S_ANY */
};

/*
 * Function irlmp_service_to_hint (service)
 *
 *    Converts a service type, to a hint bit
 *
 *    Returns: a 16 bit hint value, with the service bit set
 */
__u16 irlmp_service_to_hint(int service)
{
        __u16_host_order hint;

        hint.byte[0] = service_hint_mapping[service][0];
        hint.byte[1] = service_hint_mapping[service][1];

        return hint.word;
}
EXPORT_SYMBOL(irlmp_service_to_hint);

/*
 * Function irlmp_register_service (service)
 *
 *    Register local service with IrLMP
 *
 */
void *irlmp_register_service(__u16 hints)
{
        irlmp_service_t *service;

        IRDA_DEBUG(4, "%s(), hints = %04x\n", __func__, hints);

        /* Make a new registration */
        service = kmalloc(sizeof(irlmp_service_t), GFP_ATOMIC);
        if (!service) {
                IRDA_DEBUG(1, "%s(), Unable to kmalloc!\n", __func__);
                return NULL;
        }
        service->hints.word = hints;
        hashbin_insert(irlmp->services, (irda_queue_t *) service,
                       (long) service, NULL);

        irlmp->hints.word |= hints;

        return (void *)service;
}
EXPORT_SYMBOL(irlmp_register_service);

/*
 * Function irlmp_unregister_service (handle)
 *
 *    Unregister service with IrLMP.
 *
 *    Returns: 0 on success, -1 on error
 */
int irlmp_unregister_service(void *handle)
{
        irlmp_service_t *service;
        unsigned long flags;

        IRDA_DEBUG(4, "%s()\n", __func__);

        if (!handle)
                return -1;

        /* Caller may call with invalid handle (it's legal) - Jean II */
        service = hashbin_lock_find(irlmp->services, (long) handle, NULL);
        if (!service) {
                IRDA_DEBUG(1, "%s(), Unknown service!\n", __func__);
                return -1;
        }

        hashbin_remove_this(irlmp->services, (irda_queue_t *) service);
        kfree(service);

        /* Remove old hint bits */
        irlmp->hints.word = 0;

        /* Refresh current hint bits */
        spin_lock_irqsave(&irlmp->services->hb_spinlock, flags);
        service = (irlmp_service_t *) hashbin_get_first(irlmp->services);
        while (service) {
                irlmp->hints.word |= service->hints.word;

                service = (irlmp_service_t *)hashbin_get_next(irlmp->services);
        }
        spin_unlock_irqrestore(&irlmp->services->hb_spinlock, flags);
        return 0;
}
EXPORT_SYMBOL(irlmp_unregister_service);

/*
 * Function irlmp_register_client (hint_mask, callback1, callback2)
 *
 *    Register a local client with IrLMP
 *      First callback is selective discovery (based on hints)
 *      Second callback is for selective discovery expiries
 *
 *    Returns: handle > 0 on success, 0 on error
 */
void *irlmp_register_client(__u16 hint_mask, DISCOVERY_CALLBACK1 disco_clb,
                            DISCOVERY_CALLBACK2 expir_clb, void *priv)
{
        irlmp_client_t *client;

        IRDA_DEBUG(1, "%s()\n", __func__);
        IRDA_ASSERT(irlmp != NULL, return NULL;);

        /* Make a new registration */
        client = kmalloc(sizeof(irlmp_client_t), GFP_ATOMIC);
        if (!client) {
                IRDA_DEBUG( 1, "%s(), Unable to kmalloc!\n", __func__);
                return NULL;
        }

        /* Register the details */
        client->hint_mask.word = hint_mask;
        client->disco_callback = disco_clb;
        client->expir_callback = expir_clb;
        client->priv = priv;

        hashbin_insert(irlmp->clients, (irda_queue_t *) client,
                       (long) client, NULL);

        return (void *) client;
}
EXPORT_SYMBOL(irlmp_register_client);

/*
 * Function irlmp_update_client (handle, hint_mask, callback1, callback2)
 *
 *    Updates specified client (handle) with possibly new hint_mask and
 *    callback
 *
 *    Returns: 0 on success, -1 on error
 */
int irlmp_update_client(void *handle, __u16 hint_mask,
                        DISCOVERY_CALLBACK1 disco_clb,
                        DISCOVERY_CALLBACK2 expir_clb, void *priv)
{
        irlmp_client_t *client;

        if (!handle)
                return -1;

        client = hashbin_lock_find(irlmp->clients, (long) handle, NULL);
        if (!client) {
                IRDA_DEBUG(1, "%s(), Unknown client!\n", __func__);
                return -1;
        }

        client->hint_mask.word = hint_mask;
        client->disco_callback = disco_clb;
        client->expir_callback = expir_clb;
        client->priv = priv;

        return 0;
}
EXPORT_SYMBOL(irlmp_update_client);

/*
 * Function irlmp_unregister_client (handle)
 *
 *    Returns: 0 on success, -1 on error
 *
 */
int irlmp_unregister_client(void *handle)
{
        struct irlmp_client *client;

        IRDA_DEBUG(4, "%s()\n", __func__);

        if (!handle)
                return -1;

        /* Caller may call with invalid handle (it's legal) - Jean II */
        client = hashbin_lock_find(irlmp->clients, (long) handle, NULL);
        if (!client) {
                IRDA_DEBUG(1, "%s(), Unknown client!\n", __func__);
                return -1;
        }

        IRDA_DEBUG(4, "%s(), removing client!\n", __func__);
        hashbin_remove_this(irlmp->clients, (irda_queue_t *) client);
        kfree(client);

        return 0;
}
EXPORT_SYMBOL(irlmp_unregister_client);

/*
 * Function irlmp_slsap_inuse (slsap)
 *
 *    Check if the given source LSAP selector is in use
 *
 * This function is clearly not very efficient. On the mitigating side, the
 * stack make sure that in 99% of the cases, we are called only once
 * for each socket allocation. We could probably keep a bitmap
 * of the allocated LSAP, but I'm not sure the complexity is worth it.
 * Jean II
 */
static int irlmp_slsap_inuse(__u8 slsap_sel)
{
        struct lsap_cb *self;
        struct lap_cb *lap;
        unsigned long flags;

        IRDA_ASSERT(irlmp != NULL, return TRUE;);
        IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return TRUE;);
        IRDA_ASSERT(slsap_sel != LSAP_ANY, return TRUE;);

        IRDA_DEBUG(4, "%s()\n", __func__);

#ifdef CONFIG_IRDA_ULTRA
        /* Accept all bindings to the connectionless LSAP */
        if (slsap_sel == LSAP_CONNLESS)
                return FALSE;
#endif /* CONFIG_IRDA_ULTRA */

        /* Valid values are between 0 and 127 (0x0-0x6F) */
        if (slsap_sel > LSAP_MAX)
                return TRUE;

        /*
         *  Check if slsap is already in use. To do this we have to loop over
         *  every IrLAP connection and check every LSAP associated with each
         *  the connection.
         */
        spin_lock_irqsave_nested(&irlmp->links->hb_spinlock, flags,
                        SINGLE_DEPTH_NESTING);
        lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
        while (lap != NULL) {
                IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, goto errlap;);

                /* Careful for priority inversions here !
                 * irlmp->links is never taken while another IrDA
                 * spinlock is held, so we are safe. Jean II */
                spin_lock(&lap->lsaps->hb_spinlock);

                /* For this IrLAP, check all the LSAPs */
                self = (struct lsap_cb *) hashbin_get_first(lap->lsaps);
                while (self != NULL) {
                        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC,
                                    goto errlsap;);

                        if ((self->slsap_sel == slsap_sel)) {
                                IRDA_DEBUG(4, "Source LSAP selector=%02x in use\n",
                                           self->slsap_sel);
                                goto errlsap;
                        }
                        self = (struct lsap_cb*) hashbin_get_next(lap->lsaps);
                }
                spin_unlock(&lap->lsaps->hb_spinlock);

                /* Next LAP */
                lap = (struct lap_cb *) hashbin_get_next(irlmp->links);
        }
        spin_unlock_irqrestore(&irlmp->links->hb_spinlock, flags);

        /*
         * Server sockets are typically waiting for connections and
         * therefore reside in the unconnected list. We don't want
         * to give out their LSAPs for obvious reasons...
         * Jean II
         */
        spin_lock_irqsave(&irlmp->unconnected_lsaps->hb_spinlock, flags);

        self = (struct lsap_cb *) hashbin_get_first(irlmp->unconnected_lsaps);
        while (self != NULL) {
                IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, goto erruncon;);
                if ((self->slsap_sel == slsap_sel)) {
                        IRDA_DEBUG(4, "Source LSAP selector=%02x in use (unconnected)\n",
                                   self->slsap_sel);
                        goto erruncon;
                }
                self = (struct lsap_cb*) hashbin_get_next(irlmp->unconnected_lsaps);
        }
        spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);

        return FALSE;

        /* Error exit from within one of the two nested loops.
         * Make sure we release the right spinlock in the righ order.
         * Jean II */
errlsap:
        spin_unlock(&lap->lsaps->hb_spinlock);
IRDA_ASSERT_LABEL(errlap:)
        spin_unlock_irqrestore(&irlmp->links->hb_spinlock, flags);
        return TRUE;

        /* Error exit from within the unconnected loop.
         * Just one spinlock to release... Jean II */
erruncon:
        spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);
        return TRUE;
}

/*
 * Function irlmp_find_free_slsap ()
 *
 *    Find a free source LSAP to use. This function is called if the service
 *    user has requested a source LSAP equal to LM_ANY
 */
static __u8 irlmp_find_free_slsap(void)
{
        __u8 lsap_sel;
        int wrapped = 0;

        IRDA_ASSERT(irlmp != NULL, return -1;);
        IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return -1;);

        /* Most users don't really care which LSAPs they are given,
         * and therefore we automatically give them a free LSAP.
         * This function try to find a suitable LSAP, i.e. which is
         * not in use and is within the acceptable range. Jean II */

        do {
                /* Always increment to LSAP number before using it.
                 * In theory, we could reuse the last LSAP number, as long
                 * as it is no longer in use. Some IrDA stack do that.
                 * However, the previous socket may be half closed, i.e.
                 * we closed it, we think it's no longer in use, but the
                 * other side did not receive our close and think it's
                 * active and still send data on it.
                 * This is similar to what is done with PIDs and TCP ports.
                 * Also, this reduce the number of calls to irlmp_slsap_inuse()
                 * which is an expensive function to call.
                 * Jean II */
                irlmp->last_lsap_sel++;

                /* Check if we need to wraparound (0x70-0x7f are reserved) */
                if (irlmp->last_lsap_sel > LSAP_MAX) {
                        /* 0x00-0x10 are also reserved for well know ports */
                        irlmp->last_lsap_sel = 0x10;

                        /* Make sure we terminate the loop */
                        if (wrapped++) {
                                IRDA_ERROR("%s: no more free LSAPs !\n",
                                           __func__);
                                return 0;
                        }
                }

                /* If the LSAP is in use, try the next one.
                 * Despite the autoincrement, we need to check if the lsap
                 * is really in use or not, first because LSAP may be
                 * directly allocated in irlmp_open_lsap(), and also because
                 * we may wraparound on old sockets. Jean II */
        } while (irlmp_slsap_inuse(irlmp->last_lsap_sel));

        /* Got it ! */
        lsap_sel = irlmp->last_lsap_sel;
        IRDA_DEBUG(4, "%s(), found free lsap_sel=%02x\n",
                   __func__, lsap_sel);

        return lsap_sel;
}

/*
 * Function irlmp_convert_lap_reason (lap_reason)
 *
 *    Converts IrLAP disconnect reason codes to IrLMP disconnect reason
 *    codes
 *
 */
LM_REASON irlmp_convert_lap_reason( LAP_REASON lap_reason)
{
        int reason = LM_LAP_DISCONNECT;

        switch (lap_reason) {
        case LAP_DISC_INDICATION: /* Received a disconnect request from peer */
                IRDA_DEBUG( 1, "%s(), LAP_DISC_INDICATION\n", __func__);
                reason = LM_USER_REQUEST;
                break;
        case LAP_NO_RESPONSE:    /* To many retransmits without response */
                IRDA_DEBUG( 1, "%s(), LAP_NO_RESPONSE\n", __func__);
                reason = LM_LAP_DISCONNECT;
                break;
        case LAP_RESET_INDICATION:
                IRDA_DEBUG( 1, "%s(), LAP_RESET_INDICATION\n", __func__);
                reason = LM_LAP_RESET;
                break;
        case LAP_FOUND_NONE:
        case LAP_MEDIA_BUSY:
        case LAP_PRIMARY_CONFLICT:
                IRDA_DEBUG(1, "%s(), LAP_FOUND_NONE, LAP_MEDIA_BUSY or LAP_PRIMARY_CONFLICT\n", __func__);
                reason = LM_CONNECT_FAILURE;
                break;
        default:
                IRDA_DEBUG(1, "%s(), Unknown IrLAP disconnect reason %d!\n",
                           __func__, lap_reason);
                reason = LM_LAP_DISCONNECT;
                break;
        }

        return reason;
}

#ifdef CONFIG_PROC_FS

struct irlmp_iter_state {
        hashbin_t *hashbin;
};

#define LSAP_START_TOKEN        ((void *)1)
#define LINK_START_TOKEN        ((void *)2)

static void *irlmp_seq_hb_idx(struct irlmp_iter_state *iter, loff_t *off)
{
        void *element;

        spin_lock_irq(&iter->hashbin->hb_spinlock);
        for (element = hashbin_get_first(iter->hashbin);
             element != NULL;
             element = hashbin_get_next(iter->hashbin)) {
                if (!off || *off-- == 0) {
                        /* NB: hashbin left locked */
                        return element;
                }
        }
        spin_unlock_irq(&iter->hashbin->hb_spinlock);
        iter->hashbin = NULL;
        return NULL;
}


static void *irlmp_seq_start(struct seq_file *seq, loff_t *pos)
{
        struct irlmp_iter_state *iter = seq->private;
        void *v;
        loff_t off = *pos;

        iter->hashbin = NULL;
        if (off-- == 0)
                return LSAP_START_TOKEN;

        iter->hashbin = irlmp->unconnected_lsaps;
        v = irlmp_seq_hb_idx(iter, &off);
        if (v)
                return v;

        if (off-- == 0)
                return LINK_START_TOKEN;

        iter->hashbin = irlmp->links;
        return irlmp_seq_hb_idx(iter, &off);
}

static void *irlmp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct irlmp_iter_state *iter = seq->private;

        ++*pos;

        if (v == LSAP_START_TOKEN) {            /* start of list of lsaps */
                iter->hashbin = irlmp->unconnected_lsaps;
                v = irlmp_seq_hb_idx(iter, NULL);
                return v ? v : LINK_START_TOKEN;
        }

        if (v == LINK_START_TOKEN) {            /* start of list of links */
                iter->hashbin = irlmp->links;
                return irlmp_seq_hb_idx(iter, NULL);
        }

        v = hashbin_get_next(iter->hashbin);

        if (v == NULL) {                        /* no more in this hash bin */
                spin_unlock_irq(&iter->hashbin->hb_spinlock);

                if (iter->hashbin == irlmp->unconnected_lsaps)
                        v =  LINK_START_TOKEN;

                iter->hashbin = NULL;
        }
        return v;
}

static void irlmp_seq_stop(struct seq_file *seq, void *v)
{
        struct irlmp_iter_state *iter = seq->private;

        if (iter->hashbin)
                spin_unlock_irq(&iter->hashbin->hb_spinlock);
}

static int irlmp_seq_show(struct seq_file *seq, void *v)
{
        const struct irlmp_iter_state *iter = seq->private;
        struct lsap_cb *self = v;

        if (v == LSAP_START_TOKEN)
                seq_puts(seq, "Unconnected LSAPs:\n");
        else if (v == LINK_START_TOKEN)
                seq_puts(seq, "\nRegistered Link Layers:\n");
        else if (iter->hashbin == irlmp->unconnected_lsaps) {
                self = v;
                IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -EINVAL; );
                seq_printf(seq, "lsap state: %s, ",
                           irlsap_state[ self->lsap_state]);
                seq_printf(seq,
                           "slsap_sel: %#02x, dlsap_sel: %#02x, ",
                           self->slsap_sel, self->dlsap_sel);
                seq_printf(seq, "(%s)", self->notify.name);
                seq_printf(seq, "\n");
        } else if (iter->hashbin == irlmp->links) {
                struct lap_cb *lap = v;

                seq_printf(seq, "lap state: %s, ",
                           irlmp_state[lap->lap_state]);

                seq_printf(seq, "saddr: %#08x, daddr: %#08x, ",
                           lap->saddr, lap->daddr);
                seq_printf(seq, "num lsaps: %d",
                           HASHBIN_GET_SIZE(lap->lsaps));
                seq_printf(seq, "\n");

                /* Careful for priority inversions here !
                 * All other uses of attrib spinlock are independent of
                 * the object spinlock, so we are safe. Jean II */
                spin_lock(&lap->lsaps->hb_spinlock);

                seq_printf(seq, "\n  Connected LSAPs:\n");
                for (self = (struct lsap_cb *) hashbin_get_first(lap->lsaps);
                     self != NULL;
                     self = (struct lsap_cb *)hashbin_get_next(lap->lsaps)) {
                        IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC,
                                    goto outloop;);
                        seq_printf(seq, "  lsap state: %s, ",
                                   irlsap_state[ self->lsap_state]);
                        seq_printf(seq,
                                   "slsap_sel: %#02x, dlsap_sel: %#02x, ",
                                   self->slsap_sel, self->dlsap_sel);
                        seq_printf(seq, "(%s)", self->notify.name);
                        seq_putc(seq, '\n');

                }
        IRDA_ASSERT_LABEL(outloop:)
                spin_unlock(&lap->lsaps->hb_spinlock);
                seq_putc(seq, '\n');
        } else
                return -EINVAL;

        return 0;
}

static const struct seq_operations irlmp_seq_ops = {
        .start  = irlmp_seq_start,
        .next   = irlmp_seq_next,
        .stop   = irlmp_seq_stop,
        .show   = irlmp_seq_show,
};

static int irlmp_seq_open(struct inode *inode, struct file *file)
{
        IRDA_ASSERT(irlmp != NULL, return -EINVAL;);

        return seq_open_private(file, &irlmp_seq_ops,
                        sizeof(struct irlmp_iter_state));
}

const struct file_operations irlmp_seq_fops = {
        .owner          = THIS_MODULE,
        .open           = irlmp_seq_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release_private,
};

#endif /* PROC_FS */