net/irda/discovery.c - kernel/common - Git at Google

 /*********************************************************************
  *
  * Filename:      discovery.c
  * Version:       0.1
  * Description:   Routines for handling discoveries at the IrLMP layer
  * Status:        Experimental.
  * Author:        Dag Brattli <[email protected]>
  * Created at:    Tue Apr  6 15:33:50 1999
  * Modified at:   Sat Oct  9 17:11:31 1999
  * Modified by:   Dag Brattli <[email protected]>
  * Modified at:   Fri May 28  3:11 CST 1999
  * Modified by:   Horst von Brand <[email protected]>
  *
  *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
  *
  *     This program is free software; you can redistribute it and/or
  *     modify it under the terms of the GNU General Public License as
  *     published by the Free Software Foundation; either version 2 of
  *     the License, or (at your option) any later version.
  *
  *     This program is distributed in the hope that it will be useful,
  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  *     GNU General Public License for more details.
  *
  *     You should have received a copy of the GNU General Public License
  *     along with this program; if not, write to the Free Software
  *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  *     MA 02111-1307 USA
  *
  ********************************************************************/

 #include <linux/string.h>
 #include <linux/socket.h>
 #include <linux/fs.h>
 #include <linux/seq_file.h>

 #include <net/irda/irda.h>
 #include <net/irda/irlmp.h>

 #include <net/irda/discovery.h>

 /*
  * Function irlmp_add_discovery (cachelog, discovery)
  *
  *    Add a new discovery to the cachelog, and remove any old discoveries
  *    from the same device
  *
  * Note : we try to preserve the time this device was *first* discovered
  * (as opposed to the time of last discovery used for cleanup). This is
  * used by clients waiting for discovery events to tell if the device
  * discovered is "new" or just the same old one. They can't rely there
  * on a binary flag (new/old), because not all discovery events are
  * propagated to them, and they might not always listen, so they would
  * miss some new devices popping up...
  * Jean II
  */
 void irlmp_add_discovery(hashbin_t *cachelog, discovery_t *new)
 {
 	discovery_t *discovery, *node;
 	unsigned long flags;

 	/* Set time of first discovery if node is new (see below) */
 	new->firststamp = new->timestamp;

 	spin_lock_irqsave(&cachelog->hb_spinlock, flags);

 	/*
 	 * Remove all discoveries of devices that has previously been
 	 * discovered on the same link with the same name (info), or the
 	 * same daddr. We do this since some devices (mostly PDAs) change
 	 * their device address between every discovery.
 	 */
 	discovery = (discovery_t *) hashbin_get_first(cachelog);
 	while (discovery != NULL ) {
 		node = discovery;

 		/* Be sure to stay one item ahead */
 		discovery = (discovery_t *) hashbin_get_next(cachelog);

 		if ((node->data.saddr == new->data.saddr) &&
 		    ((node->data.daddr == new->data.daddr) ||
 		     (strcmp(node->data.info, new->data.info) == 0)))
 		{
 			/* This discovery is a previous discovery
 			 * from the same device, so just remove it
 			 */
 			hashbin_remove_this(cachelog, (irda_queue_t *) node);
 			/* Check if hints bits are unchanged */
 			if(u16ho(node->data.hints) == u16ho(new->data.hints))
 				/* Set time of first discovery for this node */
 				new->firststamp = node->firststamp;
 			kfree(node);
 		}
 	}

 	/* Insert the new and updated version */
 	hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL);

 	spin_unlock_irqrestore(&cachelog->hb_spinlock, flags);
 }

 /*
  * Function irlmp_add_discovery_log (cachelog, log)
  *
  *    Merge a disovery log into the cachelog.
  *
  */
 void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log)
 {
 	discovery_t *discovery;

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

 	/*
 	 *  If log is missing this means that IrLAP was unable to perform the
 	 *  discovery, so restart discovery again with just the half timeout
 	 *  of the normal one.
 	 */
 	/* Well... It means that there was nobody out there - Jean II */
 	if (log == NULL) {
 		/* irlmp_start_discovery_timer(irlmp, 150); */
 		return;
 	}

 	/*
 	 * Locking : we are the only owner of this discovery log, so
 	 * no need to lock it.
 	 * We just need to lock the global log in irlmp_add_discovery().
 	 */
 	discovery = (discovery_t *) hashbin_remove_first(log);
 	while (discovery != NULL) {
 		irlmp_add_discovery(cachelog, discovery);

 		discovery = (discovery_t *) hashbin_remove_first(log);
 	}

 	/* Delete the now empty log */
 	hashbin_delete(log, (FREE_FUNC) kfree);
 }

 /*
  * Function irlmp_expire_discoveries (log, saddr, force)
  *
  *    Go through all discoveries and expire all that has stayed too long
  *
  * Note : this assume that IrLAP won't change its saddr, which
  * currently is a valid assumption...
  */
 void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force)
 {
 	discovery_t *		discovery;
 	discovery_t *		curr;
 	unsigned long		flags;
 	discinfo_t *		buffer = NULL;
 	int			n;		/* Size of the full log */
 	int			i = 0;		/* How many we expired */

 	IRDA_ASSERT(log != NULL, return;);
 	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

 	spin_lock_irqsave(&log->hb_spinlock, flags);

 	discovery = (discovery_t *) hashbin_get_first(log);
 	while (discovery != NULL) {
 		/* Be sure to be one item ahead */
 		curr = discovery;
 		discovery = (discovery_t *) hashbin_get_next(log);

 		/* Test if it's time to expire this discovery */
 		if ((curr->data.saddr == saddr) &&
 		    (force ||
 		     ((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT)))
 		{
 			/* Create buffer as needed.
 			 * As this function get called a lot and most time
 			 * we don't have anything to put in the log (we are
 			 * quite picky), we can save a lot of overhead
 			 * by not calling kmalloc. Jean II */
 			if(buffer == NULL) {
 				/* Create the client specific buffer */
 				n = HASHBIN_GET_SIZE(log);
 				buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC);
 				if (buffer == NULL) {
 					spin_unlock_irqrestore(&log->hb_spinlock, flags);
 					return;
 				}

 			}

 			/* Copy discovery information */
 			memcpy(&(buffer[i]), &(curr->data),
 			       sizeof(discinfo_t));
 			i++;

 			/* Remove it from the log */
 			curr = hashbin_remove_this(log, (irda_queue_t *) curr);
 			kfree(curr);
 		}
 	}

 	/* Drop the spinlock before calling the higher layers, as
 	 * we can't guarantee they won't call us back and create a
 	 * deadlock. We will work on our own private data, so we
 	 * don't care to be interupted. - Jean II */
 	spin_unlock_irqrestore(&log->hb_spinlock, flags);

 	if(buffer == NULL)
 		return;

 	/* Tell IrLMP and registered clients about it */
 	irlmp_discovery_expiry(buffer, i);

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

 #if 0
 /*
  * Function irlmp_dump_discoveries (log)
  *
  *    Print out all discoveries in log
  *
  */
 void irlmp_dump_discoveries(hashbin_t *log)
 {
 	discovery_t *discovery;

 	IRDA_ASSERT(log != NULL, return;);

 	discovery = (discovery_t *) hashbin_get_first(log);
 	while (discovery != NULL) {
 		IRDA_DEBUG(0, "Discovery:\n");
 		IRDA_DEBUG(0, "  daddr=%08x\n", discovery->data.daddr);
 		IRDA_DEBUG(0, "  saddr=%08x\n", discovery->data.saddr);
 		IRDA_DEBUG(0, "  nickname=%s\n", discovery->data.info);

 		discovery = (discovery_t *) hashbin_get_next(log);
 	}
 }
 #endif

 /*
  * Function irlmp_copy_discoveries (log, pn, mask)
  *
  *    Copy all discoveries in a buffer
  *
  * This function implement a safe way for lmp clients to access the
  * discovery log. The basic problem is that we don't want the log
  * to change (add/remove) while the client is reading it. If the
  * lmp client manipulate directly the hashbin, he is sure to get
  * into troubles...
  * The idea is that we copy all the current discovery log in a buffer
  * which is specific to the client and pass this copy to him. As we
  * do this operation with the spinlock grabbed, we are safe...
  * Note : we don't want those clients to grab the spinlock, because
  * we have no control on how long they will hold it...
  * Note : we choose to copy the log in "struct irda_device_info" to
  * save space...
  * Note : the client must kfree himself() the log...
  * Jean II
  */
 struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn,
 						__u16 mask, int old_entries)
 {
 	discovery_t *		discovery;
 	unsigned long		flags;
 	discinfo_t *		buffer = NULL;
 	int			j_timeout = (sysctl_discovery_timeout * HZ);
 	int			n;		/* Size of the full log */
 	int			i = 0;		/* How many we picked */

 	IRDA_ASSERT(pn != NULL, return NULL;);
 	IRDA_ASSERT(log != NULL, return NULL;);

 	/* Save spin lock */
 	spin_lock_irqsave(&log->hb_spinlock, flags);

 	discovery = (discovery_t *) hashbin_get_first(log);
 	while (discovery != NULL) {
 		/* Mask out the ones we don't want :
 		 * We want to match the discovery mask, and to get only
 		 * the most recent one (unless we want old ones) */
 		if ((u16ho(discovery->data.hints) & mask) &&
 		    ((old_entries) ||
 		     ((jiffies - discovery->firststamp) < j_timeout)) ) {
 			/* Create buffer as needed.
 			 * As this function get called a lot and most time
 			 * we don't have anything to put in the log (we are
 			 * quite picky), we can save a lot of overhead
 			 * by not calling kmalloc. Jean II */
 			if(buffer == NULL) {
 				/* Create the client specific buffer */
 				n = HASHBIN_GET_SIZE(log);
 				buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC);
 				if (buffer == NULL) {
 					spin_unlock_irqrestore(&log->hb_spinlock, flags);
 					return NULL;
 				}

 			}

 			/* Copy discovery information */
 			memcpy(&(buffer[i]), &(discovery->data),
 			       sizeof(discinfo_t));
 			i++;
 		}
 		discovery = (discovery_t *) hashbin_get_next(log);
 	}

 	spin_unlock_irqrestore(&log->hb_spinlock, flags);

 	/* Get the actual number of device in the buffer and return */
 	*pn = i;
 	return(buffer);
 }

 #ifdef CONFIG_PROC_FS
 static inline discovery_t *discovery_seq_idx(loff_t pos)

 {
 	discovery_t *discovery;

 	for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog);
 	     discovery != NULL;
 	     discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) {
 		if (pos-- == 0)
 			break;
 	}

 	return discovery;
 }

 static void *discovery_seq_start(struct seq_file *seq, loff_t *pos)
 {
 	spin_lock_irq(&irlmp->cachelog->hb_spinlock);
         return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN;
 }

 static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	++*pos;
 	return (v == SEQ_START_TOKEN)
 		? (void *) hashbin_get_first(irlmp->cachelog)
 		: (void *) hashbin_get_next(irlmp->cachelog);
 }

 static void discovery_seq_stop(struct seq_file *seq, void *v)
 {
 	spin_unlock_irq(&irlmp->cachelog->hb_spinlock);
 }

 static int discovery_seq_show(struct seq_file *seq, void *v)
 {
 	if (v == SEQ_START_TOKEN)
 		seq_puts(seq, "IrLMP: Discovery log:\n\n");
 	else {
 		const discovery_t *discovery = v;

 		seq_printf(seq, "nickname: %s, hint: 0x%02x%02x",
 			   discovery->data.info,
 			   discovery->data.hints[0],
 			   discovery->data.hints[1]);
 #if 0
 		if ( discovery->data.hints[0] & HINT_PNP)
 			seq_puts(seq, "PnP Compatible ");
 		if ( discovery->data.hints[0] & HINT_PDA)
 			seq_puts(seq, "PDA/Palmtop ");
 		if ( discovery->data.hints[0] & HINT_COMPUTER)
 			seq_puts(seq, "Computer ");
 		if ( discovery->data.hints[0] & HINT_PRINTER)
 			seq_puts(seq, "Printer ");
 		if ( discovery->data.hints[0] & HINT_MODEM)
 			seq_puts(seq, "Modem ");
 		if ( discovery->data.hints[0] & HINT_FAX)
 			seq_puts(seq, "Fax ");
 		if ( discovery->data.hints[0] & HINT_LAN)
 			seq_puts(seq, "LAN Access ");

 		if ( discovery->data.hints[1] & HINT_TELEPHONY)
 			seq_puts(seq, "Telephony ");
 		if ( discovery->data.hints[1] & HINT_FILE_SERVER)
 			seq_puts(seq, "File Server ");
 		if ( discovery->data.hints[1] & HINT_COMM)
 			seq_puts(seq, "IrCOMM ");
 		if ( discovery->data.hints[1] & HINT_OBEX)
 			seq_puts(seq, "IrOBEX ");
 #endif
 		seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n",
 			       discovery->data.saddr,
 			       discovery->data.daddr);

 		seq_putc(seq, '\n');
 	}
 	return 0;
 }

 static struct seq_operations discovery_seq_ops = {
 	.start  = discovery_seq_start,
 	.next   = discovery_seq_next,
 	.stop   = discovery_seq_stop,
 	.show   = discovery_seq_show,
 };

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

 	return seq_open(file, &discovery_seq_ops);
 }

 struct file_operations discovery_seq_fops = {
 	.owner		= THIS_MODULE,
 	.open           = discovery_seq_open,
 	.read           = seq_read,
 	.llseek         = seq_lseek,
 	.release	= seq_release,
 };
 #endif
	/*********************************************************************
	*
	* Filename: discovery.c
	* Version: 0.1
	* Description: Routines for handling discoveries at the IrLMP layer
	* Status: Experimental.
	* Author: Dag Brattli <[email protected]>
	* Created at: Tue Apr 6 15:33:50 1999
	* Modified at: Sat Oct 9 17:11:31 1999
	* Modified by: Dag Brattli <[email protected]>
	* Modified at: Fri May 28 3:11 CST 1999
	* Modified by: Horst von Brand <[email protected]>
	*
	* Copyright (c) 1999 Dag Brattli, All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of
	* the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*
	********************************************************************/

	#include <linux/string.h>
	#include <linux/socket.h>
	#include <linux/fs.h>
	#include <linux/seq_file.h>

	#include <net/irda/irda.h>
	#include <net/irda/irlmp.h>

	#include <net/irda/discovery.h>

	/*
	* Function irlmp_add_discovery (cachelog, discovery)
	*
	* Add a new discovery to the cachelog, and remove any old discoveries
	* from the same device
	*
	* Note : we try to preserve the time this device was first discovered
	* (as opposed to the time of last discovery used for cleanup). This is
	* used by clients waiting for discovery events to tell if the device
	* discovered is "new" or just the same old one. They can't rely there
	* on a binary flag (new/old), because not all discovery events are
	* propagated to them, and they might not always listen, so they would
	* miss some new devices popping up...
	* Jean II
	*/
	void irlmp_add_discovery(hashbin_t cachelog, discovery_t new)
	{
	discovery_t discovery, node;
	unsigned long flags;

	/* Set time of first discovery if node is new (see below) */
	new->firststamp = new->timestamp;

	spin_lock_irqsave(&cachelog->hb_spinlock, flags);

	/*
	* Remove all discoveries of devices that has previously been
	* discovered on the same link with the same name (info), or the
	* same daddr. We do this since some devices (mostly PDAs) change
	* their device address between every discovery.
	*/
	discovery = (discovery_t *) hashbin_get_first(cachelog);
	while (discovery != NULL ) {
	node = discovery;

	/* Be sure to stay one item ahead */
	discovery = (discovery_t *) hashbin_get_next(cachelog);

	if ((node->data.saddr == new->data.saddr) &&
	((node->data.daddr == new->data.daddr) \|\|
	(strcmp(node->data.info, new->data.info) == 0)))
	{
	/* This discovery is a previous discovery
	* from the same device, so just remove it
	*/
	hashbin_remove_this(cachelog, (irda_queue_t *) node);
	/* Check if hints bits are unchanged */
	if(u16ho(node->data.hints) == u16ho(new->data.hints))
	/* Set time of first discovery for this node */
	new->firststamp = node->firststamp;
	kfree(node);
	}
	}

	/* Insert the new and updated version */
	hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL);

	spin_unlock_irqrestore(&cachelog->hb_spinlock, flags);
	}

	/*
	* Function irlmp_add_discovery_log (cachelog, log)
	*
	* Merge a disovery log into the cachelog.
	*
	*/
	void irlmp_add_discovery_log(hashbin_t cachelog, hashbin_t log)
	{
	discovery_t *discovery;

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

	/*
	* If log is missing this means that IrLAP was unable to perform the
	* discovery, so restart discovery again with just the half timeout
	* of the normal one.
	*/
	/* Well... It means that there was nobody out there - Jean II */
	if (log == NULL) {
	/* irlmp_start_discovery_timer(irlmp, 150); */
	return;
	}

	/*
	* Locking : we are the only owner of this discovery log, so
	* no need to lock it.
	* We just need to lock the global log in irlmp_add_discovery().
	*/
	discovery = (discovery_t *) hashbin_remove_first(log);
	while (discovery != NULL) {
	irlmp_add_discovery(cachelog, discovery);

	discovery = (discovery_t *) hashbin_remove_first(log);
	}

	/* Delete the now empty log */
	hashbin_delete(log, (FREE_FUNC) kfree);
	}

	/*
	* Function irlmp_expire_discoveries (log, saddr, force)
	*
	* Go through all discoveries and expire all that has stayed too long
	*
	* Note : this assume that IrLAP won't change its saddr, which
	* currently is a valid assumption...
	*/
	void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force)
	{
	discovery_t * discovery;
	discovery_t * curr;
	unsigned long flags;
	discinfo_t * buffer = NULL;
	int n; /* Size of the full log */
	int i = 0; /* How many we expired */

	IRDA_ASSERT(log != NULL, return;);
	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

	spin_lock_irqsave(&log->hb_spinlock, flags);

	discovery = (discovery_t *) hashbin_get_first(log);
	while (discovery != NULL) {
	/* Be sure to be one item ahead */
	curr = discovery;
	discovery = (discovery_t *) hashbin_get_next(log);

	/* Test if it's time to expire this discovery */
	if ((curr->data.saddr == saddr) &&
	(force \|\|
	((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT)))
	{
	/* Create buffer as needed.
	* As this function get called a lot and most time
	* we don't have anything to put in the log (we are
	* quite picky), we can save a lot of overhead
	* by not calling kmalloc. Jean II */
	if(buffer == NULL) {
	/* Create the client specific buffer */
	n = HASHBIN_GET_SIZE(log);
	buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC);
	if (buffer == NULL) {
	spin_unlock_irqrestore(&log->hb_spinlock, flags);
	return;
	}

	}

	/* Copy discovery information */
	memcpy(&(buffer[i]), &(curr->data),
	sizeof(discinfo_t));
	i++;

	/* Remove it from the log */
	curr = hashbin_remove_this(log, (irda_queue_t *) curr);
	kfree(curr);
	}
	}

	/* Drop the spinlock before calling the higher layers, as
	* we can't guarantee they won't call us back and create a
	* deadlock. We will work on our own private data, so we
	* don't care to be interupted. - Jean II */
	spin_unlock_irqrestore(&log->hb_spinlock, flags);

	if(buffer == NULL)
	return;

	/* Tell IrLMP and registered clients about it */
	irlmp_discovery_expiry(buffer, i);

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

	#if 0
	/*
	* Function irlmp_dump_discoveries (log)
	*
	* Print out all discoveries in log
	*
	*/
	void irlmp_dump_discoveries(hashbin_t *log)
	{
	discovery_t *discovery;

	IRDA_ASSERT(log != NULL, return;);

	discovery = (discovery_t *) hashbin_get_first(log);
	while (discovery != NULL) {
	IRDA_DEBUG(0, "Discovery:\n");
	IRDA_DEBUG(0, " daddr=%08x\n", discovery->data.daddr);
	IRDA_DEBUG(0, " saddr=%08x\n", discovery->data.saddr);
	IRDA_DEBUG(0, " nickname=%s\n", discovery->data.info);

	discovery = (discovery_t *) hashbin_get_next(log);
	}
	}
	#endif

	/*
	* Function irlmp_copy_discoveries (log, pn, mask)
	*
	* Copy all discoveries in a buffer
	*
	* This function implement a safe way for lmp clients to access the
	* discovery log. The basic problem is that we don't want the log
	* to change (add/remove) while the client is reading it. If the
	* lmp client manipulate directly the hashbin, he is sure to get
	* into troubles...
	* The idea is that we copy all the current discovery log in a buffer
	* which is specific to the client and pass this copy to him. As we
	* do this operation with the spinlock grabbed, we are safe...
	* Note : we don't want those clients to grab the spinlock, because
	* we have no control on how long they will hold it...
	* Note : we choose to copy the log in "struct irda_device_info" to
	* save space...
	* Note : the client must kfree himself() the log...
	* Jean II
	*/
	struct irda_device_info irlmp_copy_discoveries(hashbin_t log, int *pn,
	__u16 mask, int old_entries)
	{
	discovery_t * discovery;
	unsigned long flags;
	discinfo_t * buffer = NULL;
	int j_timeout = (sysctl_discovery_timeout * HZ);
	int n; /* Size of the full log */
	int i = 0; /* How many we picked */

	IRDA_ASSERT(pn != NULL, return NULL;);
	IRDA_ASSERT(log != NULL, return NULL;);

	/* Save spin lock */
	spin_lock_irqsave(&log->hb_spinlock, flags);

	discovery = (discovery_t *) hashbin_get_first(log);
	while (discovery != NULL) {
	/* Mask out the ones we don't want :
	* We want to match the discovery mask, and to get only
	* the most recent one (unless we want old ones) */
	if ((u16ho(discovery->data.hints) & mask) &&
	((old_entries) \|\|
	((jiffies - discovery->firststamp) < j_timeout)) ) {
	/* Create buffer as needed.
	* As this function get called a lot and most time
	* we don't have anything to put in the log (we are
	* quite picky), we can save a lot of overhead
	* by not calling kmalloc. Jean II */
	if(buffer == NULL) {
	/* Create the client specific buffer */
	n = HASHBIN_GET_SIZE(log);
	buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC);
	if (buffer == NULL) {
	spin_unlock_irqrestore(&log->hb_spinlock, flags);
	return NULL;
	}

	}

	/* Copy discovery information */
	memcpy(&(buffer[i]), &(discovery->data),
	sizeof(discinfo_t));
	i++;
	}
	discovery = (discovery_t *) hashbin_get_next(log);
	}

	spin_unlock_irqrestore(&log->hb_spinlock, flags);

	/* Get the actual number of device in the buffer and return */
	*pn = i;
	return(buffer);
	}

	#ifdef CONFIG_PROC_FS
	static inline discovery_t *discovery_seq_idx(loff_t pos)

	{
	discovery_t *discovery;

	for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog);
	discovery != NULL;
	discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) {
	if (pos-- == 0)
	break;
	}

	return discovery;
	}

	static void discovery_seq_start(struct seq_file seq, loff_t *pos)
	{
	spin_lock_irq(&irlmp->cachelog->hb_spinlock);
	return pos ? discovery_seq_idx(pos - 1) : SEQ_START_TOKEN;
	}

	static void discovery_seq_next(struct seq_file seq, void v, loff_t pos)
	{
	++*pos;
	return (v == SEQ_START_TOKEN)
	? (void *) hashbin_get_first(irlmp->cachelog)
	: (void *) hashbin_get_next(irlmp->cachelog);
	}

	static void discovery_seq_stop(struct seq_file seq, void v)
	{
	spin_unlock_irq(&irlmp->cachelog->hb_spinlock);
	}

	static int discovery_seq_show(struct seq_file seq, void v)
	{
	if (v == SEQ_START_TOKEN)
	seq_puts(seq, "IrLMP: Discovery log:\n\n");
	else {
	const discovery_t *discovery = v;

	seq_printf(seq, "nickname: %s, hint: 0x%02x%02x",
	discovery->data.info,
	discovery->data.hints[0],
	discovery->data.hints[1]);
	#if 0
	if ( discovery->data.hints[0] & HINT_PNP)
	seq_puts(seq, "PnP Compatible ");
	if ( discovery->data.hints[0] & HINT_PDA)
	seq_puts(seq, "PDA/Palmtop ");
	if ( discovery->data.hints[0] & HINT_COMPUTER)
	seq_puts(seq, "Computer ");
	if ( discovery->data.hints[0] & HINT_PRINTER)
	seq_puts(seq, "Printer ");
	if ( discovery->data.hints[0] & HINT_MODEM)
	seq_puts(seq, "Modem ");
	if ( discovery->data.hints[0] & HINT_FAX)
	seq_puts(seq, "Fax ");
	if ( discovery->data.hints[0] & HINT_LAN)
	seq_puts(seq, "LAN Access ");

	if ( discovery->data.hints[1] & HINT_TELEPHONY)
	seq_puts(seq, "Telephony ");
	if ( discovery->data.hints[1] & HINT_FILE_SERVER)
	seq_puts(seq, "File Server ");
	if ( discovery->data.hints[1] & HINT_COMM)
	seq_puts(seq, "IrCOMM ");
	if ( discovery->data.hints[1] & HINT_OBEX)
	seq_puts(seq, "IrOBEX ");
	#endif
	seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n",
	discovery->data.saddr,
	discovery->data.daddr);

	seq_putc(seq, '\n');
	}
	return 0;
	}

	static struct seq_operations discovery_seq_ops = {
	.start = discovery_seq_start,
	.next = discovery_seq_next,
	.stop = discovery_seq_stop,
	.show = discovery_seq_show,
	};

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

	return seq_open(file, &discovery_seq_ops);
	}

	struct file_operations discovery_seq_fops = {
	.owner = THIS_MODULE,
	.open = discovery_seq_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
	};
	#endif