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, see <http://www.gnu.org/licenses/>. 28 * 29 ********************************************************************/ 30 31#include <linux/string.h> 32#include <linux/socket.h> 33#include <linux/fs.h> 34#include <linux/seq_file.h> 35#include <linux/slab.h> 36#include <linux/export.h> 37 38#include <net/irda/irda.h> 39#include <net/irda/irlmp.h> 40 41#include <net/irda/discovery.h> 42 43#include <asm/unaligned.h> 44 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 */ 60void 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 70 /* 71 * Remove all discoveries of devices that has previously been 72 * discovered on the same link with the same name (info), or the 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) && 84 ((node->data.daddr == new->data.daddr) || 85 (strcmp(node->data.info, new->data.info) == 0))) 86 { 87 /* This discovery is a previous discovery 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 */ 92 if (get_unaligned((__u16 *)node->data.hints) == get_unaligned((__u16 *)new->data.hints)) 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 */ 111void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log) 112{ 113 discovery_t *discovery; 114 115 /* 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 } 137 138 /* 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 */ 150void 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;); 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); 196 kfree(curr); 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 203 * don't care to be interrupted. - Jean II */ 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 */ 223void 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) { 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); 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 */ 261struct 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) */ 282 if ((get_unaligned((__u16 *)discovery->data.hints) & mask) && 283 ((old_entries) || 284 ((jiffies - discovery->firststamp) < j_timeout))) { 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; 313 return buffer; 314} 315 316#ifdef CONFIG_PROC_FS 317static inline discovery_t *discovery_seq_idx(loff_t pos) 318 319{ 320 discovery_t *discovery; 321 322 for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); 323 discovery != NULL; 324 discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { 325 if (pos-- == 0) 326 break; 327 } 328 329 return discovery; 330} 331 332static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) 333{ 334 spin_lock_irq(&irlmp->cachelog->hb_spinlock); 335 return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; 336} 337 338static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) 339{ 340 ++*pos; 341 return (v == SEQ_START_TOKEN) 342 ? (void *) hashbin_get_first(irlmp->cachelog) 343 : (void *) hashbin_get_next(irlmp->cachelog); 344} 345 346static void discovery_seq_stop(struct seq_file *seq, void *v) 347{ 348 spin_unlock_irq(&irlmp->cachelog->hb_spinlock); 349} 350 351static 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; 357 358 seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", 359 discovery->data.info, 360 discovery->data.hints[0], 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 "); 377 378 if ( discovery->data.hints[1] & HINT_TELEPHONY) 379 seq_puts(seq, "Telephony "); 380 if ( discovery->data.hints[1] & HINT_FILE_SERVER) 381 seq_puts(seq, "File Server "); 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 "); 386#endif 387 seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", 388 discovery->data.saddr, 389 discovery->data.daddr); 390 391 seq_putc(seq, '\n'); 392 } 393 return 0; 394} 395 396static const struct seq_operations discovery_seq_ops = { 397 .start = discovery_seq_start, 398 .next = discovery_seq_next, 399 .stop = discovery_seq_stop, 400 .show = discovery_seq_show, 401}; 402 403static 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 410const struct file_operations discovery_seq_fops = { 411 .owner = THIS_MODULE, 412 .open = discovery_seq_open, 413 .read = seq_read, 414 .llseek = seq_lseek, 415 .release = seq_release, 416}; 417#endif 418