path: root/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];

static 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",
	"UNKNOWN",
};

const char *irlmp_reason_str(LM_REASON reason)
{
	reason = min_t(size_t, reason, ARRAY_SIZE(irlmp_reasons) - 1);
	return irlmp_reasons[reason];
}

/*
 * 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)
		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)
		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) {
		net_warn_ratelimited("%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 [%d]\n", __func__,
		   irlmp_reason_str(reason), 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)){
		net_warn_ratelimited("%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++) {
				net_err_ratelimited("%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 */