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1da177e4 | 1 | /********************************************************************* |
6819bc2e | 2 | * |
1da177e4 LT |
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> | |
6819bc2e | 13 | * |
1da177e4 | 14 | * Copyright (c) 1999 Dag Brattli, All Rights Reserved. |
6819bc2e YH |
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 | |
1da177e4 | 19 | * the License, or (at your option) any later version. |
6819bc2e | 20 | * |
1da177e4 LT |
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. | |
6819bc2e YH |
25 | * |
26 | * You should have received a copy of the GNU General Public License | |
d3770509 | 27 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
6819bc2e | 28 | * |
1da177e4 LT |
29 | ********************************************************************/ |
30 | ||
31 | #include <linux/string.h> | |
32 | #include <linux/socket.h> | |
d7fe0f24 | 33 | #include <linux/fs.h> |
1da177e4 | 34 | #include <linux/seq_file.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
bc3b2d7f | 36 | #include <linux/export.h> |
1da177e4 LT |
37 | |
38 | #include <net/irda/irda.h> | |
39 | #include <net/irda/irlmp.h> | |
40 | ||
41 | #include <net/irda/discovery.h> | |
42 | ||
33222383 GY |
43 | #include <asm/unaligned.h> |
44 | ||
1da177e4 LT |
45 | /* |
46 | * Function irlmp_add_discovery (cachelog, discovery) | |
47 | * | |
48 | * Add a new discovery to the cachelog, and remove any old discoveries | |
49 | * from the same device | |
50 | * | |
51 | * Note : we try to preserve the time this device was *first* discovered | |
52 | * (as opposed to the time of last discovery used for cleanup). This is | |
53 | * used by clients waiting for discovery events to tell if the device | |
54 | * discovered is "new" or just the same old one. They can't rely there | |
55 | * on a binary flag (new/old), because not all discovery events are | |
56 | * propagated to them, and they might not always listen, so they would | |
57 | * miss some new devices popping up... | |
58 | * Jean II | |
59 | */ | |
60 | void irlmp_add_discovery(hashbin_t *cachelog, discovery_t *new) | |
61 | { | |
62 | discovery_t *discovery, *node; | |
63 | unsigned long flags; | |
64 | ||
65 | /* Set time of first discovery if node is new (see below) */ | |
66 | new->firststamp = new->timestamp; | |
67 | ||
68 | spin_lock_irqsave(&cachelog->hb_spinlock, flags); | |
69 | ||
6819bc2e YH |
70 | /* |
71 | * Remove all discoveries of devices that has previously been | |
72 | * discovered on the same link with the same name (info), or the | |
1da177e4 LT |
73 | * same daddr. We do this since some devices (mostly PDAs) change |
74 | * their device address between every discovery. | |
75 | */ | |
76 | discovery = (discovery_t *) hashbin_get_first(cachelog); | |
77 | while (discovery != NULL ) { | |
78 | node = discovery; | |
79 | ||
80 | /* Be sure to stay one item ahead */ | |
81 | discovery = (discovery_t *) hashbin_get_next(cachelog); | |
82 | ||
83 | if ((node->data.saddr == new->data.saddr) && | |
6819bc2e | 84 | ((node->data.daddr == new->data.daddr) || |
1da177e4 LT |
85 | (strcmp(node->data.info, new->data.info) == 0))) |
86 | { | |
6819bc2e | 87 | /* This discovery is a previous discovery |
1da177e4 LT |
88 | * from the same device, so just remove it |
89 | */ | |
90 | hashbin_remove_this(cachelog, (irda_queue_t *) node); | |
91 | /* Check if hints bits are unchanged */ | |
33222383 | 92 | if (get_unaligned((__u16 *)node->data.hints) == get_unaligned((__u16 *)new->data.hints)) |
1da177e4 LT |
93 | /* Set time of first discovery for this node */ |
94 | new->firststamp = node->firststamp; | |
95 | kfree(node); | |
96 | } | |
97 | } | |
98 | ||
99 | /* Insert the new and updated version */ | |
100 | hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL); | |
101 | ||
102 | spin_unlock_irqrestore(&cachelog->hb_spinlock, flags); | |
103 | } | |
104 | ||
105 | /* | |
106 | * Function irlmp_add_discovery_log (cachelog, log) | |
107 | * | |
108 | * Merge a disovery log into the cachelog. | |
109 | * | |
110 | */ | |
111 | void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log) | |
112 | { | |
113 | discovery_t *discovery; | |
114 | ||
1da177e4 LT |
115 | /* |
116 | * If log is missing this means that IrLAP was unable to perform the | |
117 | * discovery, so restart discovery again with just the half timeout | |
118 | * of the normal one. | |
119 | */ | |
120 | /* Well... It means that there was nobody out there - Jean II */ | |
121 | if (log == NULL) { | |
122 | /* irlmp_start_discovery_timer(irlmp, 150); */ | |
123 | return; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Locking : we are the only owner of this discovery log, so | |
128 | * no need to lock it. | |
129 | * We just need to lock the global log in irlmp_add_discovery(). | |
130 | */ | |
131 | discovery = (discovery_t *) hashbin_remove_first(log); | |
132 | while (discovery != NULL) { | |
133 | irlmp_add_discovery(cachelog, discovery); | |
134 | ||
135 | discovery = (discovery_t *) hashbin_remove_first(log); | |
136 | } | |
6819bc2e | 137 | |
1da177e4 LT |
138 | /* Delete the now empty log */ |
139 | hashbin_delete(log, (FREE_FUNC) kfree); | |
140 | } | |
141 | ||
142 | /* | |
143 | * Function irlmp_expire_discoveries (log, saddr, force) | |
144 | * | |
145 | * Go through all discoveries and expire all that has stayed too long | |
146 | * | |
147 | * Note : this assume that IrLAP won't change its saddr, which | |
148 | * currently is a valid assumption... | |
149 | */ | |
150 | void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force) | |
151 | { | |
152 | discovery_t * discovery; | |
153 | discovery_t * curr; | |
154 | unsigned long flags; | |
155 | discinfo_t * buffer = NULL; | |
156 | int n; /* Size of the full log */ | |
157 | int i = 0; /* How many we expired */ | |
158 | ||
159 | IRDA_ASSERT(log != NULL, return;); | |
1da177e4 LT |
160 | spin_lock_irqsave(&log->hb_spinlock, flags); |
161 | ||
162 | discovery = (discovery_t *) hashbin_get_first(log); | |
163 | while (discovery != NULL) { | |
164 | /* Be sure to be one item ahead */ | |
165 | curr = discovery; | |
166 | discovery = (discovery_t *) hashbin_get_next(log); | |
167 | ||
168 | /* Test if it's time to expire this discovery */ | |
169 | if ((curr->data.saddr == saddr) && | |
170 | (force || | |
171 | ((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT))) | |
172 | { | |
173 | /* Create buffer as needed. | |
174 | * As this function get called a lot and most time | |
175 | * we don't have anything to put in the log (we are | |
176 | * quite picky), we can save a lot of overhead | |
177 | * by not calling kmalloc. Jean II */ | |
178 | if(buffer == NULL) { | |
179 | /* Create the client specific buffer */ | |
180 | n = HASHBIN_GET_SIZE(log); | |
181 | buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); | |
182 | if (buffer == NULL) { | |
183 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
184 | return; | |
185 | } | |
186 | ||
187 | } | |
188 | ||
189 | /* Copy discovery information */ | |
190 | memcpy(&(buffer[i]), &(curr->data), | |
191 | sizeof(discinfo_t)); | |
192 | i++; | |
193 | ||
194 | /* Remove it from the log */ | |
195 | curr = hashbin_remove_this(log, (irda_queue_t *) curr); | |
a51482bd | 196 | kfree(curr); |
1da177e4 LT |
197 | } |
198 | } | |
199 | ||
200 | /* Drop the spinlock before calling the higher layers, as | |
201 | * we can't guarantee they won't call us back and create a | |
202 | * deadlock. We will work on our own private data, so we | |
3a4fa0a2 | 203 | * don't care to be interrupted. - Jean II */ |
1da177e4 LT |
204 | spin_unlock_irqrestore(&log->hb_spinlock, flags); |
205 | ||
206 | if(buffer == NULL) | |
207 | return; | |
208 | ||
209 | /* Tell IrLMP and registered clients about it */ | |
210 | irlmp_discovery_expiry(buffer, i); | |
211 | ||
212 | /* Free up our buffer */ | |
213 | kfree(buffer); | |
214 | } | |
215 | ||
216 | #if 0 | |
217 | /* | |
218 | * Function irlmp_dump_discoveries (log) | |
219 | * | |
220 | * Print out all discoveries in log | |
221 | * | |
222 | */ | |
223 | void irlmp_dump_discoveries(hashbin_t *log) | |
224 | { | |
225 | discovery_t *discovery; | |
226 | ||
227 | IRDA_ASSERT(log != NULL, return;); | |
228 | ||
229 | discovery = (discovery_t *) hashbin_get_first(log); | |
230 | while (discovery != NULL) { | |
955a9d20 JP |
231 | pr_debug("Discovery:\n"); |
232 | pr_debug(" daddr=%08x\n", discovery->data.daddr); | |
233 | pr_debug(" saddr=%08x\n", discovery->data.saddr); | |
234 | pr_debug(" nickname=%s\n", discovery->data.info); | |
1da177e4 LT |
235 | |
236 | discovery = (discovery_t *) hashbin_get_next(log); | |
237 | } | |
238 | } | |
239 | #endif | |
240 | ||
241 | /* | |
242 | * Function irlmp_copy_discoveries (log, pn, mask) | |
243 | * | |
244 | * Copy all discoveries in a buffer | |
245 | * | |
246 | * This function implement a safe way for lmp clients to access the | |
247 | * discovery log. The basic problem is that we don't want the log | |
248 | * to change (add/remove) while the client is reading it. If the | |
249 | * lmp client manipulate directly the hashbin, he is sure to get | |
250 | * into troubles... | |
251 | * The idea is that we copy all the current discovery log in a buffer | |
252 | * which is specific to the client and pass this copy to him. As we | |
253 | * do this operation with the spinlock grabbed, we are safe... | |
254 | * Note : we don't want those clients to grab the spinlock, because | |
255 | * we have no control on how long they will hold it... | |
256 | * Note : we choose to copy the log in "struct irda_device_info" to | |
257 | * save space... | |
258 | * Note : the client must kfree himself() the log... | |
259 | * Jean II | |
260 | */ | |
261 | struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn, | |
262 | __u16 mask, int old_entries) | |
263 | { | |
264 | discovery_t * discovery; | |
265 | unsigned long flags; | |
266 | discinfo_t * buffer = NULL; | |
267 | int j_timeout = (sysctl_discovery_timeout * HZ); | |
268 | int n; /* Size of the full log */ | |
269 | int i = 0; /* How many we picked */ | |
270 | ||
271 | IRDA_ASSERT(pn != NULL, return NULL;); | |
272 | IRDA_ASSERT(log != NULL, return NULL;); | |
273 | ||
274 | /* Save spin lock */ | |
275 | spin_lock_irqsave(&log->hb_spinlock, flags); | |
276 | ||
277 | discovery = (discovery_t *) hashbin_get_first(log); | |
278 | while (discovery != NULL) { | |
279 | /* Mask out the ones we don't want : | |
280 | * We want to match the discovery mask, and to get only | |
281 | * the most recent one (unless we want old ones) */ | |
33222383 | 282 | if ((get_unaligned((__u16 *)discovery->data.hints) & mask) && |
1da177e4 | 283 | ((old_entries) || |
33222383 | 284 | ((jiffies - discovery->firststamp) < j_timeout))) { |
1da177e4 LT |
285 | /* Create buffer as needed. |
286 | * As this function get called a lot and most time | |
287 | * we don't have anything to put in the log (we are | |
288 | * quite picky), we can save a lot of overhead | |
289 | * by not calling kmalloc. Jean II */ | |
290 | if(buffer == NULL) { | |
291 | /* Create the client specific buffer */ | |
292 | n = HASHBIN_GET_SIZE(log); | |
293 | buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); | |
294 | if (buffer == NULL) { | |
295 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
296 | return NULL; | |
297 | } | |
298 | ||
299 | } | |
300 | ||
301 | /* Copy discovery information */ | |
302 | memcpy(&(buffer[i]), &(discovery->data), | |
303 | sizeof(discinfo_t)); | |
304 | i++; | |
305 | } | |
306 | discovery = (discovery_t *) hashbin_get_next(log); | |
307 | } | |
308 | ||
309 | spin_unlock_irqrestore(&log->hb_spinlock, flags); | |
310 | ||
311 | /* Get the actual number of device in the buffer and return */ | |
312 | *pn = i; | |
a02cec21 | 313 | return buffer; |
1da177e4 LT |
314 | } |
315 | ||
316 | #ifdef CONFIG_PROC_FS | |
317 | static inline discovery_t *discovery_seq_idx(loff_t pos) | |
318 | ||
319 | { | |
320 | discovery_t *discovery; | |
321 | ||
6819bc2e | 322 | for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); |
1da177e4 LT |
323 | discovery != NULL; |
324 | discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { | |
325 | if (pos-- == 0) | |
326 | break; | |
327 | } | |
6819bc2e | 328 | |
1da177e4 LT |
329 | return discovery; |
330 | } | |
331 | ||
332 | static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) | |
333 | { | |
334 | spin_lock_irq(&irlmp->cachelog->hb_spinlock); | |
6819bc2e | 335 | return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; |
1da177e4 LT |
336 | } |
337 | ||
338 | static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
339 | { | |
340 | ++*pos; | |
6819bc2e | 341 | return (v == SEQ_START_TOKEN) |
1da177e4 LT |
342 | ? (void *) hashbin_get_first(irlmp->cachelog) |
343 | : (void *) hashbin_get_next(irlmp->cachelog); | |
344 | } | |
345 | ||
346 | static void discovery_seq_stop(struct seq_file *seq, void *v) | |
347 | { | |
348 | spin_unlock_irq(&irlmp->cachelog->hb_spinlock); | |
349 | } | |
350 | ||
351 | static int discovery_seq_show(struct seq_file *seq, void *v) | |
352 | { | |
353 | if (v == SEQ_START_TOKEN) | |
354 | seq_puts(seq, "IrLMP: Discovery log:\n\n"); | |
355 | else { | |
356 | const discovery_t *discovery = v; | |
357 | ||
6819bc2e | 358 | seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", |
1da177e4 | 359 | discovery->data.info, |
6819bc2e | 360 | discovery->data.hints[0], |
1da177e4 LT |
361 | discovery->data.hints[1]); |
362 | #if 0 | |
363 | if ( discovery->data.hints[0] & HINT_PNP) | |
364 | seq_puts(seq, "PnP Compatible "); | |
365 | if ( discovery->data.hints[0] & HINT_PDA) | |
366 | seq_puts(seq, "PDA/Palmtop "); | |
367 | if ( discovery->data.hints[0] & HINT_COMPUTER) | |
368 | seq_puts(seq, "Computer "); | |
369 | if ( discovery->data.hints[0] & HINT_PRINTER) | |
370 | seq_puts(seq, "Printer "); | |
371 | if ( discovery->data.hints[0] & HINT_MODEM) | |
372 | seq_puts(seq, "Modem "); | |
373 | if ( discovery->data.hints[0] & HINT_FAX) | |
374 | seq_puts(seq, "Fax "); | |
375 | if ( discovery->data.hints[0] & HINT_LAN) | |
376 | seq_puts(seq, "LAN Access "); | |
6819bc2e | 377 | |
1da177e4 LT |
378 | if ( discovery->data.hints[1] & HINT_TELEPHONY) |
379 | seq_puts(seq, "Telephony "); | |
380 | if ( discovery->data.hints[1] & HINT_FILE_SERVER) | |
6819bc2e | 381 | seq_puts(seq, "File Server "); |
1da177e4 LT |
382 | if ( discovery->data.hints[1] & HINT_COMM) |
383 | seq_puts(seq, "IrCOMM "); | |
384 | if ( discovery->data.hints[1] & HINT_OBEX) | |
385 | seq_puts(seq, "IrOBEX "); | |
6819bc2e | 386 | #endif |
1da177e4 LT |
387 | seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", |
388 | discovery->data.saddr, | |
389 | discovery->data.daddr); | |
6819bc2e | 390 | |
1da177e4 LT |
391 | seq_putc(seq, '\n'); |
392 | } | |
393 | return 0; | |
394 | } | |
395 | ||
56b3d975 | 396 | static const struct seq_operations discovery_seq_ops = { |
1da177e4 LT |
397 | .start = discovery_seq_start, |
398 | .next = discovery_seq_next, | |
399 | .stop = discovery_seq_stop, | |
400 | .show = discovery_seq_show, | |
401 | }; | |
402 | ||
403 | static int discovery_seq_open(struct inode *inode, struct file *file) | |
404 | { | |
405 | IRDA_ASSERT(irlmp != NULL, return -EINVAL;); | |
406 | ||
407 | return seq_open(file, &discovery_seq_ops); | |
408 | } | |
409 | ||
9a32144e | 410 | const struct file_operations discovery_seq_fops = { |
1da177e4 LT |
411 | .owner = THIS_MODULE, |
412 | .open = discovery_seq_open, | |
413 | .read = seq_read, | |
414 | .llseek = seq_lseek, | |
415 | .release = seq_release, | |
416 | }; | |
417 | #endif |