summaryrefslogtreecommitdiff
path: root/net/irda/discovery.c
blob: 80c33f408e3fc2ccee1059d6141728cda89d1a27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
/*********************************************************************
 *
 * 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>

/*
 * 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 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 ((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 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