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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); | |
a51482bd | 197 | kfree(curr); |
1da177e4 LT |
198 | } |
199 | } | |
200 | ||
201 | /* Drop the spinlock before calling the higher layers, as | |
202 | * we can't guarantee they won't call us back and create a | |
203 | * deadlock. We will work on our own private data, so we | |
204 | * don't care to be interupted. - Jean II */ | |
205 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
206 | ||
207 | if(buffer == NULL) | |
208 | return; | |
209 | ||
210 | /* Tell IrLMP and registered clients about it */ | |
211 | irlmp_discovery_expiry(buffer, i); | |
212 | ||
213 | /* Free up our buffer */ | |
214 | kfree(buffer); | |
215 | } | |
216 | ||
217 | #if 0 | |
218 | /* | |
219 | * Function irlmp_dump_discoveries (log) | |
220 | * | |
221 | * Print out all discoveries in log | |
222 | * | |
223 | */ | |
224 | void irlmp_dump_discoveries(hashbin_t *log) | |
225 | { | |
226 | discovery_t *discovery; | |
227 | ||
228 | IRDA_ASSERT(log != NULL, return;); | |
229 | ||
230 | discovery = (discovery_t *) hashbin_get_first(log); | |
231 | while (discovery != NULL) { | |
232 | IRDA_DEBUG(0, "Discovery:\n"); | |
233 | IRDA_DEBUG(0, " daddr=%08x\n", discovery->data.daddr); | |
234 | IRDA_DEBUG(0, " saddr=%08x\n", discovery->data.saddr); | |
235 | IRDA_DEBUG(0, " nickname=%s\n", discovery->data.info); | |
236 | ||
237 | discovery = (discovery_t *) hashbin_get_next(log); | |
238 | } | |
239 | } | |
240 | #endif | |
241 | ||
242 | /* | |
243 | * Function irlmp_copy_discoveries (log, pn, mask) | |
244 | * | |
245 | * Copy all discoveries in a buffer | |
246 | * | |
247 | * This function implement a safe way for lmp clients to access the | |
248 | * discovery log. The basic problem is that we don't want the log | |
249 | * to change (add/remove) while the client is reading it. If the | |
250 | * lmp client manipulate directly the hashbin, he is sure to get | |
251 | * into troubles... | |
252 | * The idea is that we copy all the current discovery log in a buffer | |
253 | * which is specific to the client and pass this copy to him. As we | |
254 | * do this operation with the spinlock grabbed, we are safe... | |
255 | * Note : we don't want those clients to grab the spinlock, because | |
256 | * we have no control on how long they will hold it... | |
257 | * Note : we choose to copy the log in "struct irda_device_info" to | |
258 | * save space... | |
259 | * Note : the client must kfree himself() the log... | |
260 | * Jean II | |
261 | */ | |
262 | struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn, | |
263 | __u16 mask, int old_entries) | |
264 | { | |
265 | discovery_t * discovery; | |
266 | unsigned long flags; | |
267 | discinfo_t * buffer = NULL; | |
268 | int j_timeout = (sysctl_discovery_timeout * HZ); | |
269 | int n; /* Size of the full log */ | |
270 | int i = 0; /* How many we picked */ | |
271 | ||
272 | IRDA_ASSERT(pn != NULL, return NULL;); | |
273 | IRDA_ASSERT(log != NULL, return NULL;); | |
274 | ||
275 | /* Save spin lock */ | |
276 | spin_lock_irqsave(&log->hb_spinlock, flags); | |
277 | ||
278 | discovery = (discovery_t *) hashbin_get_first(log); | |
279 | while (discovery != NULL) { | |
280 | /* Mask out the ones we don't want : | |
281 | * We want to match the discovery mask, and to get only | |
282 | * the most recent one (unless we want old ones) */ | |
283 | if ((u16ho(discovery->data.hints) & mask) && | |
284 | ((old_entries) || | |
285 | ((jiffies - discovery->firststamp) < j_timeout)) ) { | |
286 | /* Create buffer as needed. | |
287 | * As this function get called a lot and most time | |
288 | * we don't have anything to put in the log (we are | |
289 | * quite picky), we can save a lot of overhead | |
290 | * by not calling kmalloc. Jean II */ | |
291 | if(buffer == NULL) { | |
292 | /* Create the client specific buffer */ | |
293 | n = HASHBIN_GET_SIZE(log); | |
294 | buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); | |
295 | if (buffer == NULL) { | |
296 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
297 | return NULL; | |
298 | } | |
299 | ||
300 | } | |
301 | ||
302 | /* Copy discovery information */ | |
303 | memcpy(&(buffer[i]), &(discovery->data), | |
304 | sizeof(discinfo_t)); | |
305 | i++; | |
306 | } | |
307 | discovery = (discovery_t *) hashbin_get_next(log); | |
308 | } | |
309 | ||
310 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
311 | ||
312 | /* Get the actual number of device in the buffer and return */ | |
313 | *pn = i; | |
314 | return(buffer); | |
315 | } | |
316 | ||
317 | #ifdef CONFIG_PROC_FS | |
318 | static inline discovery_t *discovery_seq_idx(loff_t pos) | |
319 | ||
320 | { | |
321 | discovery_t *discovery; | |
322 | ||
323 | for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); | |
324 | discovery != NULL; | |
325 | discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { | |
326 | if (pos-- == 0) | |
327 | break; | |
328 | } | |
329 | ||
330 | return discovery; | |
331 | } | |
332 | ||
333 | static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) | |
334 | { | |
335 | spin_lock_irq(&irlmp->cachelog->hb_spinlock); | |
336 | return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; | |
337 | } | |
338 | ||
339 | static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
340 | { | |
341 | ++*pos; | |
342 | return (v == SEQ_START_TOKEN) | |
343 | ? (void *) hashbin_get_first(irlmp->cachelog) | |
344 | : (void *) hashbin_get_next(irlmp->cachelog); | |
345 | } | |
346 | ||
347 | static void discovery_seq_stop(struct seq_file *seq, void *v) | |
348 | { | |
349 | spin_unlock_irq(&irlmp->cachelog->hb_spinlock); | |
350 | } | |
351 | ||
352 | static int discovery_seq_show(struct seq_file *seq, void *v) | |
353 | { | |
354 | if (v == SEQ_START_TOKEN) | |
355 | seq_puts(seq, "IrLMP: Discovery log:\n\n"); | |
356 | else { | |
357 | const discovery_t *discovery = v; | |
358 | ||
359 | seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", | |
360 | discovery->data.info, | |
361 | discovery->data.hints[0], | |
362 | discovery->data.hints[1]); | |
363 | #if 0 | |
364 | if ( discovery->data.hints[0] & HINT_PNP) | |
365 | seq_puts(seq, "PnP Compatible "); | |
366 | if ( discovery->data.hints[0] & HINT_PDA) | |
367 | seq_puts(seq, "PDA/Palmtop "); | |
368 | if ( discovery->data.hints[0] & HINT_COMPUTER) | |
369 | seq_puts(seq, "Computer "); | |
370 | if ( discovery->data.hints[0] & HINT_PRINTER) | |
371 | seq_puts(seq, "Printer "); | |
372 | if ( discovery->data.hints[0] & HINT_MODEM) | |
373 | seq_puts(seq, "Modem "); | |
374 | if ( discovery->data.hints[0] & HINT_FAX) | |
375 | seq_puts(seq, "Fax "); | |
376 | if ( discovery->data.hints[0] & HINT_LAN) | |
377 | seq_puts(seq, "LAN Access "); | |
378 | ||
379 | if ( discovery->data.hints[1] & HINT_TELEPHONY) | |
380 | seq_puts(seq, "Telephony "); | |
381 | if ( discovery->data.hints[1] & HINT_FILE_SERVER) | |
382 | seq_puts(seq, "File Server "); | |
383 | if ( discovery->data.hints[1] & HINT_COMM) | |
384 | seq_puts(seq, "IrCOMM "); | |
385 | if ( discovery->data.hints[1] & HINT_OBEX) | |
386 | seq_puts(seq, "IrOBEX "); | |
387 | #endif | |
388 | seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", | |
389 | discovery->data.saddr, | |
390 | discovery->data.daddr); | |
391 | ||
392 | seq_putc(seq, '\n'); | |
393 | } | |
394 | return 0; | |
395 | } | |
396 | ||
397 | static struct seq_operations discovery_seq_ops = { | |
398 | .start = discovery_seq_start, | |
399 | .next = discovery_seq_next, | |
400 | .stop = discovery_seq_stop, | |
401 | .show = discovery_seq_show, | |
402 | }; | |
403 | ||
404 | static int discovery_seq_open(struct inode *inode, struct file *file) | |
405 | { | |
406 | IRDA_ASSERT(irlmp != NULL, return -EINVAL;); | |
407 | ||
408 | return seq_open(file, &discovery_seq_ops); | |
409 | } | |
410 | ||
411 | struct file_operations discovery_seq_fops = { | |
412 | .owner = THIS_MODULE, | |
413 | .open = discovery_seq_open, | |
414 | .read = seq_read, | |
415 | .llseek = seq_lseek, | |
416 | .release = seq_release, | |
417 | }; | |
418 | #endif |