Linux-2.6.33.2/net/irda/discovery.c
/*********************************************************************
*
* Filename: discovery.c
* Version: 0.1
* Description: Routines for handling discoveries at the IrLMP layer
* Status: Experimental.
* Author: Dag Brattli <dagb@cs.uit.no>
* Created at: Tue Apr 6 15:33:50 1999
* Modified at: Sat Oct 9 17:11:31 1999
* Modified by: Dag Brattli <dagb@cs.uit.no>
* Modified at: Fri May 28 3:11 CST 1999
* Modified by: Horst von Brand <vonbrand@sleipnir.valparaiso.cl>
*
* 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>
#include <asm/unaligned.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 (get_unaligned((__u16 *)node->data.hints) == get_unaligned((__u16 *)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", __func__);
/*
* 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", __func__);
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 interrupted. - 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 ((get_unaligned((__u16 *)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 const 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);
}
const struct file_operations discovery_seq_fops = {
.owner = THIS_MODULE,
.open = discovery_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif