Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/net/irda/discovery.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 12761 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /********************************************************************* |
2 | * |
3 | * Filename: discovery.c |
4 | * Version: 0.1 |
5 | * Description: Routines for handling discoveries at the IrLMP layer |
6 | * Status: Experimental. |
7 | * Author: Dag Brattli <dagb@cs.uit.no> |
8 | * Created at: Tue Apr 6 15:33:50 1999 |
9 | * Modified at: Sat Oct 9 17:11:31 1999 |
10 | * Modified by: Dag Brattli <dagb@cs.uit.no> |
11 | * Modified at: Fri May 28 3:11 CST 1999 |
12 | * Modified by: Horst von Brand <vonbrand@sleipnir.valparaiso.cl> |
13 | * |
14 | * Copyright (c) 1999 Dag Brattli, All Rights Reserved. |
15 | * |
16 | * This program is free software; you can redistribute it and/or |
17 | * modify it under the terms of the GNU General Public License as |
18 | * published by the Free Software Foundation; either version 2 of |
19 | * the License, or (at your option) any later version. |
20 | * |
21 | * This program is distributed in the hope that it will be useful, |
22 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
24 | * GNU General Public License for more details. |
25 | * |
26 | * You should have received a copy of the GNU General Public License |
27 | * along with this program; if not, write to the Free Software |
28 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
29 | * MA 02111-1307 USA |
30 | * |
31 | ********************************************************************/ |
32 | |
33 | #include <linux/string.h> |
34 | #include <linux/socket.h> |
35 | #include <linux/seq_file.h> |
36 | |
37 | #include <net/irda/irda.h> |
38 | #include <net/irda/irlmp.h> |
39 | |
40 | #include <net/irda/discovery.h> |
41 | |
42 | /* |
43 | * Function irlmp_add_discovery (cachelog, discovery) |
44 | * |
45 | * Add a new discovery to the cachelog, and remove any old discoveries |
46 | * from the same device |
47 | * |
48 | * Note : we try to preserve the time this device was *first* discovered |
49 | * (as opposed to the time of last discovery used for cleanup). This is |
50 | * used by clients waiting for discovery events to tell if the device |
51 | * discovered is "new" or just the same old one. They can't rely there |
52 | * on a binary flag (new/old), because not all discovery events are |
53 | * propagated to them, and they might not always listen, so they would |
54 | * miss some new devices popping up... |
55 | * Jean II |
56 | */ |
57 | void irlmp_add_discovery(hashbin_t *cachelog, discovery_t *new) |
58 | { |
59 | discovery_t *discovery, *node; |
60 | unsigned long flags; |
61 | |
62 | /* Set time of first discovery if node is new (see below) */ |
63 | new->firststamp = new->timestamp; |
64 | |
65 | spin_lock_irqsave(&cachelog->hb_spinlock, flags); |
66 | |
67 | /* |
68 | * Remove all discoveries of devices that has previously been |
69 | * discovered on the same link with the same name (info), or the |
70 | * same daddr. We do this since some devices (mostly PDAs) change |
71 | * their device address between every discovery. |
72 | */ |
73 | discovery = (discovery_t *) hashbin_get_first(cachelog); |
74 | while (discovery != NULL ) { |
75 | node = discovery; |
76 | |
77 | /* Be sure to stay one item ahead */ |
78 | discovery = (discovery_t *) hashbin_get_next(cachelog); |
79 | |
80 | if ((node->data.saddr == new->data.saddr) && |
81 | ((node->data.daddr == new->data.daddr) || |
82 | (strcmp(node->data.info, new->data.info) == 0))) |
83 | { |
84 | /* This discovery is a previous discovery |
85 | * from the same device, so just remove it |
86 | */ |
87 | hashbin_remove_this(cachelog, (irda_queue_t *) node); |
88 | /* Check if hints bits are unchanged */ |
89 | if(u16ho(node->data.hints) == u16ho(new->data.hints)) |
90 | /* Set time of first discovery for this node */ |
91 | new->firststamp = node->firststamp; |
92 | kfree(node); |
93 | } |
94 | } |
95 | |
96 | /* Insert the new and updated version */ |
97 | hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL); |
98 | |
99 | spin_unlock_irqrestore(&cachelog->hb_spinlock, flags); |
100 | } |
101 | |
102 | /* |
103 | * Function irlmp_add_discovery_log (cachelog, log) |
104 | * |
105 | * Merge a disovery log into the cachelog. |
106 | * |
107 | */ |
108 | void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log) |
109 | { |
110 | discovery_t *discovery; |
111 | |
112 | IRDA_DEBUG(4, "%s()\n", __FUNCTION__); |
113 | |
114 | /* |
115 | * If log is missing this means that IrLAP was unable to perform the |
116 | * discovery, so restart discovery again with just the half timeout |
117 | * of the normal one. |
118 | */ |
119 | /* Well... It means that there was nobody out there - Jean II */ |
120 | if (log == NULL) { |
121 | /* irlmp_start_discovery_timer(irlmp, 150); */ |
122 | return; |
123 | } |
124 | |
125 | /* |
126 | * Locking : we are the only owner of this discovery log, so |
127 | * no need to lock it. |
128 | * We just need to lock the global log in irlmp_add_discovery(). |
129 | */ |
130 | discovery = (discovery_t *) hashbin_remove_first(log); |
131 | while (discovery != NULL) { |
132 | irlmp_add_discovery(cachelog, discovery); |
133 | |
134 | discovery = (discovery_t *) hashbin_remove_first(log); |
135 | } |
136 | |
137 | /* Delete the now empty log */ |
138 | hashbin_delete(log, (FREE_FUNC) kfree); |
139 | } |
140 | |
141 | /* |
142 | * Function irlmp_expire_discoveries (log, saddr, force) |
143 | * |
144 | * Go through all discoveries and expire all that has stayed too long |
145 | * |
146 | * Note : this assume that IrLAP won't change its saddr, which |
147 | * currently is a valid assumption... |
148 | */ |
149 | void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force) |
150 | { |
151 | discovery_t * discovery; |
152 | discovery_t * curr; |
153 | unsigned long flags; |
154 | discinfo_t * buffer = NULL; |
155 | int n; /* Size of the full log */ |
156 | int i = 0; /* How many we expired */ |
157 | |
158 | IRDA_ASSERT(log != NULL, return;); |
159 | IRDA_DEBUG(4, "%s()\n", __FUNCTION__); |
160 | |
161 | spin_lock_irqsave(&log->hb_spinlock, flags); |
162 | |
163 | discovery = (discovery_t *) hashbin_get_first(log); |
164 | while (discovery != NULL) { |
165 | /* Be sure to be one item ahead */ |
166 | curr = discovery; |
167 | discovery = (discovery_t *) hashbin_get_next(log); |
168 | |
169 | /* Test if it's time to expire this discovery */ |
170 | if ((curr->data.saddr == saddr) && |
171 | (force || |
172 | ((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT))) |
173 | { |
174 | /* Create buffer as needed. |
175 | * As this function get called a lot and most time |
176 | * we don't have anything to put in the log (we are |
177 | * quite picky), we can save a lot of overhead |
178 | * by not calling kmalloc. Jean II */ |
179 | if(buffer == NULL) { |
180 | /* Create the client specific buffer */ |
181 | n = HASHBIN_GET_SIZE(log); |
182 | buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); |
183 | if (buffer == NULL) { |
184 | spin_unlock_irqrestore(&log->hb_spinlock, flags); |
185 | return; |
186 | } |
187 | |
188 | } |
189 | |
190 | /* Copy discovery information */ |
191 | memcpy(&(buffer[i]), &(curr->data), |
192 | sizeof(discinfo_t)); |
193 | i++; |
194 | |
195 | /* Remove it from the log */ |
196 | curr = hashbin_remove_this(log, (irda_queue_t *) curr); |
197 | if (curr) |
198 | kfree(curr); |
199 | } |
200 | } |
201 | |
202 | /* Drop the spinlock before calling the higher layers, as |
203 | * we can't guarantee they won't call us back and create a |
204 | * deadlock. We will work on our own private data, so we |
205 | * don't care to be interupted. - Jean II */ |
206 | spin_unlock_irqrestore(&log->hb_spinlock, flags); |
207 | |
208 | if(buffer == NULL) |
209 | return; |
210 | |
211 | /* Tell IrLMP and registered clients about it */ |
212 | irlmp_discovery_expiry(buffer, i); |
213 | |
214 | /* Free up our buffer */ |
215 | kfree(buffer); |
216 | } |
217 | |
218 | #if 0 |
219 | /* |
220 | * Function irlmp_dump_discoveries (log) |
221 | * |
222 | * Print out all discoveries in log |
223 | * |
224 | */ |
225 | void irlmp_dump_discoveries(hashbin_t *log) |
226 | { |
227 | discovery_t *discovery; |
228 | |
229 | IRDA_ASSERT(log != NULL, return;); |
230 | |
231 | discovery = (discovery_t *) hashbin_get_first(log); |
232 | while (discovery != NULL) { |
233 | IRDA_DEBUG(0, "Discovery:\n"); |
234 | IRDA_DEBUG(0, " daddr=%08x\n", discovery->data.daddr); |
235 | IRDA_DEBUG(0, " saddr=%08x\n", discovery->data.saddr); |
236 | IRDA_DEBUG(0, " nickname=%s\n", discovery->data.info); |
237 | |
238 | discovery = (discovery_t *) hashbin_get_next(log); |
239 | } |
240 | } |
241 | #endif |
242 | |
243 | /* |
244 | * Function irlmp_copy_discoveries (log, pn, mask) |
245 | * |
246 | * Copy all discoveries in a buffer |
247 | * |
248 | * This function implement a safe way for lmp clients to access the |
249 | * discovery log. The basic problem is that we don't want the log |
250 | * to change (add/remove) while the client is reading it. If the |
251 | * lmp client manipulate directly the hashbin, he is sure to get |
252 | * into troubles... |
253 | * The idea is that we copy all the current discovery log in a buffer |
254 | * which is specific to the client and pass this copy to him. As we |
255 | * do this operation with the spinlock grabbed, we are safe... |
256 | * Note : we don't want those clients to grab the spinlock, because |
257 | * we have no control on how long they will hold it... |
258 | * Note : we choose to copy the log in "struct irda_device_info" to |
259 | * save space... |
260 | * Note : the client must kfree himself() the log... |
261 | * Jean II |
262 | */ |
263 | struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn, |
264 | __u16 mask, int old_entries) |
265 | { |
266 | discovery_t * discovery; |
267 | unsigned long flags; |
268 | discinfo_t * buffer = NULL; |
269 | int j_timeout = (sysctl_discovery_timeout * HZ); |
270 | int n; /* Size of the full log */ |
271 | int i = 0; /* How many we picked */ |
272 | |
273 | IRDA_ASSERT(pn != NULL, return NULL;); |
274 | IRDA_ASSERT(log != NULL, return NULL;); |
275 | |
276 | /* Save spin lock */ |
277 | spin_lock_irqsave(&log->hb_spinlock, flags); |
278 | |
279 | discovery = (discovery_t *) hashbin_get_first(log); |
280 | while (discovery != NULL) { |
281 | /* Mask out the ones we don't want : |
282 | * We want to match the discovery mask, and to get only |
283 | * the most recent one (unless we want old ones) */ |
284 | if ((u16ho(discovery->data.hints) & mask) && |
285 | ((old_entries) || |
286 | ((jiffies - discovery->firststamp) < j_timeout)) ) { |
287 | /* Create buffer as needed. |
288 | * As this function get called a lot and most time |
289 | * we don't have anything to put in the log (we are |
290 | * quite picky), we can save a lot of overhead |
291 | * by not calling kmalloc. Jean II */ |
292 | if(buffer == NULL) { |
293 | /* Create the client specific buffer */ |
294 | n = HASHBIN_GET_SIZE(log); |
295 | buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); |
296 | if (buffer == NULL) { |
297 | spin_unlock_irqrestore(&log->hb_spinlock, flags); |
298 | return NULL; |
299 | } |
300 | |
301 | } |
302 | |
303 | /* Copy discovery information */ |
304 | memcpy(&(buffer[i]), &(discovery->data), |
305 | sizeof(discinfo_t)); |
306 | i++; |
307 | } |
308 | discovery = (discovery_t *) hashbin_get_next(log); |
309 | } |
310 | |
311 | spin_unlock_irqrestore(&log->hb_spinlock, flags); |
312 | |
313 | /* Get the actual number of device in the buffer and return */ |
314 | *pn = i; |
315 | return(buffer); |
316 | } |
317 | |
318 | #ifdef CONFIG_PROC_FS |
319 | static inline discovery_t *discovery_seq_idx(loff_t pos) |
320 | |
321 | { |
322 | discovery_t *discovery; |
323 | |
324 | for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); |
325 | discovery != NULL; |
326 | discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { |
327 | if (pos-- == 0) |
328 | break; |
329 | } |
330 | |
331 | return discovery; |
332 | } |
333 | |
334 | static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) |
335 | { |
336 | spin_lock_irq(&irlmp->cachelog->hb_spinlock); |
337 | return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; |
338 | } |
339 | |
340 | static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
341 | { |
342 | ++*pos; |
343 | return (v == SEQ_START_TOKEN) |
344 | ? (void *) hashbin_get_first(irlmp->cachelog) |
345 | : (void *) hashbin_get_next(irlmp->cachelog); |
346 | } |
347 | |
348 | static void discovery_seq_stop(struct seq_file *seq, void *v) |
349 | { |
350 | spin_unlock_irq(&irlmp->cachelog->hb_spinlock); |
351 | } |
352 | |
353 | static int discovery_seq_show(struct seq_file *seq, void *v) |
354 | { |
355 | if (v == SEQ_START_TOKEN) |
356 | seq_puts(seq, "IrLMP: Discovery log:\n\n"); |
357 | else { |
358 | const discovery_t *discovery = v; |
359 | |
360 | seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", |
361 | discovery->data.info, |
362 | discovery->data.hints[0], |
363 | discovery->data.hints[1]); |
364 | #if 0 |
365 | if ( discovery->data.hints[0] & HINT_PNP) |
366 | seq_puts(seq, "PnP Compatible "); |
367 | if ( discovery->data.hints[0] & HINT_PDA) |
368 | seq_puts(seq, "PDA/Palmtop "); |
369 | if ( discovery->data.hints[0] & HINT_COMPUTER) |
370 | seq_puts(seq, "Computer "); |
371 | if ( discovery->data.hints[0] & HINT_PRINTER) |
372 | seq_puts(seq, "Printer "); |
373 | if ( discovery->data.hints[0] & HINT_MODEM) |
374 | seq_puts(seq, "Modem "); |
375 | if ( discovery->data.hints[0] & HINT_FAX) |
376 | seq_puts(seq, "Fax "); |
377 | if ( discovery->data.hints[0] & HINT_LAN) |
378 | seq_puts(seq, "LAN Access "); |
379 | |
380 | if ( discovery->data.hints[1] & HINT_TELEPHONY) |
381 | seq_puts(seq, "Telephony "); |
382 | if ( discovery->data.hints[1] & HINT_FILE_SERVER) |
383 | seq_puts(seq, "File Server "); |
384 | if ( discovery->data.hints[1] & HINT_COMM) |
385 | seq_puts(seq, "IrCOMM "); |
386 | if ( discovery->data.hints[1] & HINT_OBEX) |
387 | seq_puts(seq, "IrOBEX "); |
388 | #endif |
389 | seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", |
390 | discovery->data.saddr, |
391 | discovery->data.daddr); |
392 | |
393 | seq_putc(seq, '\n'); |
394 | } |
395 | return 0; |
396 | } |
397 | |
398 | static struct seq_operations discovery_seq_ops = { |
399 | .start = discovery_seq_start, |
400 | .next = discovery_seq_next, |
401 | .stop = discovery_seq_stop, |
402 | .show = discovery_seq_show, |
403 | }; |
404 | |
405 | static int discovery_seq_open(struct inode *inode, struct file *file) |
406 | { |
407 | IRDA_ASSERT(irlmp != NULL, return -EINVAL;); |
408 | |
409 | return seq_open(file, &discovery_seq_ops); |
410 | } |
411 | |
412 | struct file_operations discovery_seq_fops = { |
413 | .owner = THIS_MODULE, |
414 | .open = discovery_seq_open, |
415 | .read = seq_read, |
416 | .llseek = seq_lseek, |
417 | .release = seq_release, |
418 | }; |
419 | #endif |