ieee80211_node.c revision 127876
1/*- 2 * Copyright (c) 2001 Atsushi Onoe 3 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * Alternatively, this software may be distributed under the terms of the 18 * GNU General Public License ("GPL") version 2 as published by the Free 19 * Software Foundation. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_node.c 127876 2004-04-05 04:15:55Z sam $"); 35 36#include "opt_inet.h" 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/mbuf.h> 41#include <sys/malloc.h> 42#include <sys/kernel.h> 43#include <sys/socket.h> 44#include <sys/sockio.h> 45#include <sys/endian.h> 46#include <sys/errno.h> 47#include <sys/bus.h> 48#include <sys/proc.h> 49#include <sys/sysctl.h> 50 51#include <machine/atomic.h> 52 53#include <net/if.h> 54#include <net/if_dl.h> 55#include <net/if_media.h> 56#include <net/if_arp.h> 57#include <net/ethernet.h> 58#include <net/if_llc.h> 59 60#include <net80211/ieee80211_var.h> 61 62#include <net/bpf.h> 63 64#ifdef INET 65#include <netinet/in.h> 66#include <netinet/if_ether.h> 67#endif 68 69static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); 70static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); 71static void ieee80211_node_copy(struct ieee80211com *, 72 struct ieee80211_node *, const struct ieee80211_node *); 73static u_int8_t ieee80211_node_getrssi(struct ieee80211com *, 74 struct ieee80211_node *); 75 76static void ieee80211_setup_node(struct ieee80211com *ic, 77 struct ieee80211_node *ni, u_int8_t *macaddr); 78static void _ieee80211_free_node(struct ieee80211com *, 79 struct ieee80211_node *); 80 81MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state"); 82 83void 84ieee80211_node_attach(struct ifnet *ifp) 85{ 86 struct ieee80211com *ic = (void *)ifp; 87 88 /* XXX need unit */ 89 IEEE80211_NODE_LOCK_INIT(ic, ifp->if_xname); 90 TAILQ_INIT(&ic->ic_node); 91 ic->ic_node_alloc = ieee80211_node_alloc; 92 ic->ic_node_free = ieee80211_node_free; 93 ic->ic_node_copy = ieee80211_node_copy; 94 ic->ic_node_getrssi = ieee80211_node_getrssi; 95 ic->ic_scangen = 1; 96} 97 98void 99ieee80211_node_lateattach(struct ifnet *ifp) 100{ 101 struct ieee80211com *ic = (void *)ifp; 102 struct ieee80211_node *ni; 103 104 ni = (*ic->ic_node_alloc)(ic); 105 KASSERT(ni != NULL, ("unable to setup inital BSS node")); 106 ni->ni_chan = IEEE80211_CHAN_ANYC; 107 ic->ic_bss = ni; 108 ic->ic_txpower = IEEE80211_TXPOWER_MAX; 109} 110 111void 112ieee80211_node_detach(struct ifnet *ifp) 113{ 114 struct ieee80211com *ic = (void *)ifp; 115 116 if (ic->ic_bss != NULL) 117 (*ic->ic_node_free)(ic, ic->ic_bss); 118 ieee80211_free_allnodes(ic); 119 IEEE80211_NODE_LOCK_DESTROY(ic); 120} 121 122/* 123 * AP scanning support. 124 */ 125 126/* 127 * Initialize the active channel set based on the set 128 * of available channels and the current PHY mode. 129 */ 130static void 131ieee80211_reset_scan(struct ifnet *ifp) 132{ 133 struct ieee80211com *ic = (void *)ifp; 134 135 memcpy(ic->ic_chan_scan, ic->ic_chan_active, 136 sizeof(ic->ic_chan_active)); 137 /* NB: hack, setup so next_scan starts with the first channel */ 138 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) 139 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; 140} 141 142/* 143 * Begin an active scan. 144 */ 145void 146ieee80211_begin_scan(struct ifnet *ifp) 147{ 148 struct ieee80211com *ic = (void *)ifp; 149 150 /* 151 * In all but hostap mode scanning starts off in 152 * an active mode before switching to passive. 153 */ 154 if (ic->ic_opmode != IEEE80211_M_HOSTAP) { 155 ic->ic_flags |= IEEE80211_F_ASCAN; 156 ic->ic_stats.is_scan_active++; 157 } else 158 ic->ic_stats.is_scan_passive++; 159 if (ifp->if_flags & IFF_DEBUG) 160 if_printf(ifp, "begin %s scan\n", 161 (ic->ic_flags & IEEE80211_F_ASCAN) ? 162 "active" : "passive"); 163 /* 164 * Clear scan state and flush any previously seen 165 * AP's. Note that the latter assumes we don't act 166 * as both an AP and a station, otherwise we'll 167 * potentially flush state of stations associated 168 * with us. 169 */ 170 ieee80211_reset_scan(ifp); 171 ieee80211_free_allnodes(ic); 172 173 /* Scan the next channel. */ 174 ieee80211_next_scan(ifp); 175} 176 177/* 178 * Switch to the next channel marked for scanning. 179 */ 180void 181ieee80211_next_scan(struct ifnet *ifp) 182{ 183 struct ieee80211com *ic = (void *)ifp; 184 struct ieee80211_channel *chan; 185 186 chan = ic->ic_bss->ni_chan; 187 for (;;) { 188 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 189 chan = &ic->ic_channels[0]; 190 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 191 /* 192 * Honor channels marked passive-only 193 * during an active scan. 194 */ 195 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 196 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 197 break; 198 } 199 if (chan == ic->ic_bss->ni_chan) { 200 ieee80211_end_scan(ifp); 201 return; 202 } 203 } 204 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 205 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", 206 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 207 ieee80211_chan2ieee(ic, chan))); 208 ic->ic_bss->ni_chan = chan; 209 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 210} 211 212void 213ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 214{ 215 struct ieee80211_node *ni; 216 struct ifnet *ifp = &ic->ic_if; 217 218 ni = ic->ic_bss; 219 if (ifp->if_flags & IFF_DEBUG) 220 if_printf(ifp, "creating ibss\n"); 221 ic->ic_flags |= IEEE80211_F_SIBSS; 222 ni->ni_chan = chan; 223 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; 224 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); 225 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); 226 if (ic->ic_opmode == IEEE80211_M_IBSS) 227 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 228 ni->ni_esslen = ic->ic_des_esslen; 229 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 230 ni->ni_rssi = 0; 231 ni->ni_rstamp = 0; 232 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 233 ni->ni_intval = ic->ic_lintval; 234 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 235 if (ic->ic_flags & IEEE80211_F_WEPON) 236 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 237 if (ic->ic_phytype == IEEE80211_T_FH) { 238 ni->ni_fhdwell = 200; /* XXX */ 239 ni->ni_fhindex = 1; 240 } 241 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 242} 243 244static int 245ieee80211_match_bss(struct ifnet *ifp, struct ieee80211_node *ni) 246{ 247 struct ieee80211com *ic = (void *)ifp; 248 u_int8_t rate; 249 int fail; 250 251 fail = 0; 252 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 253 fail |= 0x01; 254 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 255 ni->ni_chan != ic->ic_des_chan) 256 fail |= 0x01; 257 if (ic->ic_opmode == IEEE80211_M_IBSS) { 258 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 259 fail |= 0x02; 260 } else { 261 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 262 fail |= 0x02; 263 } 264 if (ic->ic_flags & IEEE80211_F_WEPON) { 265 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 266 fail |= 0x04; 267 } else { 268 /* XXX does this mean privacy is supported or required? */ 269 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 270 fail |= 0x04; 271 } 272 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 273 if (rate & IEEE80211_RATE_BASIC) 274 fail |= 0x08; 275 if (ic->ic_des_esslen != 0 && 276 (ni->ni_esslen != ic->ic_des_esslen || 277 memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) 278 fail |= 0x10; 279 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 280 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 281 fail |= 0x20; 282#ifdef IEEE80211_DEBUG 283 if (ifp->if_flags & IFF_DEBUG) { 284 printf(" %c %s", fail ? '-' : '+', 285 ether_sprintf(ni->ni_macaddr)); 286 printf(" %s%c", ether_sprintf(ni->ni_bssid), 287 fail & 0x20 ? '!' : ' '); 288 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 289 fail & 0x01 ? '!' : ' '); 290 printf(" %+4d", ni->ni_rssi); 291 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 292 fail & 0x08 ? '!' : ' '); 293 printf(" %4s%c", 294 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 295 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 296 "????", 297 fail & 0x02 ? '!' : ' '); 298 printf(" %3s%c ", 299 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 300 "wep" : "no", 301 fail & 0x04 ? '!' : ' '); 302 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 303 printf("%s\n", fail & 0x10 ? "!" : ""); 304 } 305#endif 306 return fail; 307} 308 309/* 310 * Complete a scan of potential channels. 311 */ 312void 313ieee80211_end_scan(struct ifnet *ifp) 314{ 315 struct ieee80211com *ic = (void *)ifp; 316 struct ieee80211_node *ni, *nextbs, *selbs; 317 int i, fail; 318 319 ic->ic_flags &= ~IEEE80211_F_ASCAN; 320 ni = TAILQ_FIRST(&ic->ic_node); 321 322 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 323 /* XXX off stack? */ 324 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 325 /* 326 * The passive scan to look for existing AP's completed, 327 * select a channel to camp on. Identify the channels 328 * that already have one or more AP's and try to locate 329 * an unnoccupied one. If that fails, pick a random 330 * channel from the active set. 331 */ 332 for (; ni != NULL; ni = nextbs) { 333 ieee80211_ref_node(ni); 334 nextbs = TAILQ_NEXT(ni, ni_list); 335 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 336 ieee80211_free_node(ic, ni); 337 } 338 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 339 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 340 break; 341 if (i == IEEE80211_CHAN_MAX) { 342 fail = arc4random() & 3; /* random 0-3 */ 343 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 344 if (isset(ic->ic_chan_active, i) && fail-- == 0) 345 break; 346 } 347 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 348 return; 349 } 350 if (ni == NULL) { 351 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 352 notfound: 353 if (ic->ic_opmode == IEEE80211_M_IBSS && 354 (ic->ic_flags & IEEE80211_F_IBSSON) && 355 ic->ic_des_esslen != 0) { 356 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 357 return; 358 } 359 /* 360 * Reset the list of channels to scan and start again. 361 */ 362 ieee80211_reset_scan(ifp); 363 ieee80211_next_scan(ifp); 364 return; 365 } 366 selbs = NULL; 367 if (ifp->if_flags & IFF_DEBUG) 368 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); 369 for (; ni != NULL; ni = nextbs) { 370 ieee80211_ref_node(ni); 371 nextbs = TAILQ_NEXT(ni, ni_list); 372 if (ni->ni_fails) { 373 /* 374 * The configuration of the access points may change 375 * during my scan. So delete the entry for the AP 376 * and retry to associate if there is another beacon. 377 */ 378 if (ni->ni_fails++ > 2) 379 ieee80211_free_node(ic, ni); 380 continue; 381 } 382 if (ieee80211_match_bss(ifp, ni) == 0) { 383 if (selbs == NULL) 384 selbs = ni; 385 else if (ni->ni_rssi > selbs->ni_rssi) { 386 ieee80211_unref_node(&selbs); 387 selbs = ni; 388 } else 389 ieee80211_unref_node(&ni); 390 } else { 391 ieee80211_unref_node(&ni); 392 } 393 } 394 if (selbs == NULL) 395 goto notfound; 396 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 397 if (ic->ic_opmode == IEEE80211_M_IBSS) { 398 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 399 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 400 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 401 selbs->ni_fails++; 402 ieee80211_unref_node(&selbs); 403 goto notfound; 404 } 405 ieee80211_unref_node(&selbs); 406 /* 407 * Discard scan set; the nodes have a refcnt of zero 408 * and have not asked the driver to setup private 409 * node state. Let them be repopulated on demand either 410 * through transmission (ieee80211_find_txnode) or receipt 411 * of a probe response (to be added). 412 */ 413 ieee80211_free_allnodes(ic); 414 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 415 } else { 416 ieee80211_unref_node(&selbs); 417 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 418 } 419} 420 421static struct ieee80211_node * 422ieee80211_node_alloc(struct ieee80211com *ic) 423{ 424 struct ieee80211_node *ni; 425 MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node), 426 M_80211_NODE, M_NOWAIT | M_ZERO); 427 return ni; 428} 429 430static void 431ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 432{ 433 FREE(ni, M_80211_NODE); 434} 435 436static void 437ieee80211_node_copy(struct ieee80211com *ic, 438 struct ieee80211_node *dst, const struct ieee80211_node *src) 439{ 440 *dst = *src; 441} 442 443static u_int8_t 444ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) 445{ 446 return ni->ni_rssi; 447} 448 449static void 450ieee80211_setup_node(struct ieee80211com *ic, 451 struct ieee80211_node *ni, u_int8_t *macaddr) 452{ 453 int hash; 454 455 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 456 hash = IEEE80211_NODE_HASH(macaddr); 457 ni->ni_refcnt = 1; /* mark referenced */ 458 IEEE80211_NODE_LOCK(ic); 459 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 460 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 461 /* 462 * Note we don't enable the inactive timer when acting 463 * as a station. Nodes created in this mode represent 464 * AP's identified while scanning. If we time them out 465 * then several things happen: we can't return the data 466 * to users to show the list of AP's we encountered, and 467 * more importantly, we'll incorrectly deauthenticate 468 * ourself because the inactivity timer will kick us off. 469 */ 470 if (ic->ic_opmode != IEEE80211_M_STA) 471 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 472 IEEE80211_NODE_UNLOCK(ic); 473} 474 475struct ieee80211_node * 476ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 477{ 478 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 479 if (ni != NULL) 480 ieee80211_setup_node(ic, ni, macaddr); 481 else 482 ic->ic_stats.is_rx_nodealloc++; 483 return ni; 484} 485 486struct ieee80211_node * 487ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 488{ 489 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 490 if (ni != NULL) { 491 ieee80211_setup_node(ic, ni, macaddr); 492 /* 493 * Inherit from ic_bss. 494 */ 495 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid); 496 ni->ni_chan = ic->ic_bss->ni_chan; 497 } else 498 ic->ic_stats.is_rx_nodealloc++; 499 return ni; 500} 501 502static struct ieee80211_node * 503_ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 504{ 505 struct ieee80211_node *ni; 506 int hash; 507 508 IEEE80211_NODE_LOCK_ASSERT(ic); 509 510 hash = IEEE80211_NODE_HASH(macaddr); 511 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 512 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 513 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 514 return ni; 515 } 516 } 517 return NULL; 518} 519 520struct ieee80211_node * 521ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 522{ 523 struct ieee80211_node *ni; 524 525 IEEE80211_NODE_LOCK(ic); 526 ni = _ieee80211_find_node(ic, macaddr); 527 IEEE80211_NODE_UNLOCK(ic); 528 return ni; 529} 530 531/* 532 * Return a reference to the appropriate node for sending 533 * a data frame. This handles node discovery in adhoc networks. 534 */ 535struct ieee80211_node * 536ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr) 537{ 538 struct ieee80211_node *ni; 539 540 /* 541 * The destination address should be in the node table 542 * unless we are operating in station mode or this is a 543 * multicast/broadcast frame. 544 */ 545 if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr)) 546 return ic->ic_bss; 547 548 /* XXX can't hold lock across dup_bss 'cuz of recursive locking */ 549 IEEE80211_NODE_LOCK(ic); 550 ni = _ieee80211_find_node(ic, macaddr); 551 IEEE80211_NODE_UNLOCK(ic); 552 if (ni == NULL && 553 (ic->ic_opmode == IEEE80211_M_IBSS || 554 ic->ic_opmode == IEEE80211_M_AHDEMO)) { 555 /* 556 * Fake up a node; this handles node discovery in 557 * adhoc mode. Note that for the driver's benefit 558 * we we treat this like an association so the driver 559 * has an opportunity to setup it's private state. 560 * 561 * XXX need better way to handle this; issue probe 562 * request so we can deduce rate set, etc. 563 */ 564 ni = ieee80211_dup_bss(ic, macaddr); 565 if (ni != NULL) { 566 /* XXX no rate negotiation; just dup */ 567 ni->ni_rates = ic->ic_bss->ni_rates; 568 if (ic->ic_newassoc) 569 (*ic->ic_newassoc)(ic, ni, 1); 570 } 571 } 572 return ni; 573} 574 575/* 576 * Like find but search based on the channel too. 577 */ 578struct ieee80211_node * 579ieee80211_lookup_node(struct ieee80211com *ic, 580 u_int8_t *macaddr, struct ieee80211_channel *chan) 581{ 582 struct ieee80211_node *ni; 583 int hash; 584 585 hash = IEEE80211_NODE_HASH(macaddr); 586 IEEE80211_NODE_LOCK(ic); 587 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 588 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && 589 ni->ni_chan == chan) { 590 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 591 break; 592 } 593 } 594 IEEE80211_NODE_UNLOCK(ic); 595 return ni; 596} 597 598static void 599_ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 600{ 601 KASSERT(ni != ic->ic_bss, ("freeing bss node")); 602 603 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 604 LIST_REMOVE(ni, ni_hash); 605 if (TAILQ_EMPTY(&ic->ic_node)) 606 ic->ic_inact_timer = 0; 607 (*ic->ic_node_free)(ic, ni); 608} 609 610void 611ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 612{ 613 KASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 614 615 /* XXX need equivalent of atomic_dec_and_test */ 616 atomic_subtract_int(&ni->ni_refcnt, 1); 617 if (atomic_cmpset_int(&ni->ni_refcnt, 0, 1)) { 618 IEEE80211_NODE_LOCK(ic); 619 _ieee80211_free_node(ic, ni); 620 IEEE80211_NODE_UNLOCK(ic); 621 } 622} 623 624void 625ieee80211_free_allnodes(struct ieee80211com *ic) 626{ 627 struct ieee80211_node *ni; 628 629 IEEE80211_NODE_LOCK(ic); 630 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 631 _ieee80211_free_node(ic, ni); 632 IEEE80211_NODE_UNLOCK(ic); 633} 634 635/* 636 * Timeout inactive nodes. Note that we cannot hold the node 637 * lock while sending a frame as this would lead to a LOR. 638 * Instead we use a generation number to mark nodes that we've 639 * scanned and drop the lock and restart a scan if we have to 640 * time out a node. Since we are single-threaded by virtue of 641 * controlling the inactivity timer we can be sure this will 642 * process each node only once. 643 */ 644void 645ieee80211_timeout_nodes(struct ieee80211com *ic) 646{ 647 struct ieee80211_node *ni; 648 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ 649 650restart: 651 IEEE80211_NODE_LOCK(ic); 652 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { 653 if (ni->ni_scangen == gen) /* previously handled */ 654 continue; 655 ni->ni_scangen = gen; 656 if (++ni->ni_inact > IEEE80211_INACT_MAX) { 657 IEEE80211_DPRINTF(("station %s timed out " 658 "due to inactivity (%u secs)\n", 659 ether_sprintf(ni->ni_macaddr), 660 ni->ni_inact)); 661 /* 662 * Send a deauthenticate frame. 663 * 664 * Drop the node lock before sending the 665 * deauthentication frame in case the driver takes 666 * a lock, as this will result in a LOR between the 667 * node lock and the driver lock. 668 */ 669 IEEE80211_NODE_UNLOCK(ic); 670 IEEE80211_SEND_MGMT(ic, ni, 671 IEEE80211_FC0_SUBTYPE_DEAUTH, 672 IEEE80211_REASON_AUTH_EXPIRE); 673 ieee80211_free_node(ic, ni); 674 ic->ic_stats.is_node_timeout++; 675 goto restart; 676 } 677 } 678 if (!TAILQ_EMPTY(&ic->ic_node)) 679 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 680 IEEE80211_NODE_UNLOCK(ic); 681} 682 683void 684ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 685{ 686 struct ieee80211_node *ni; 687 688 IEEE80211_NODE_LOCK(ic); 689 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 690 (*f)(arg, ni); 691 IEEE80211_NODE_UNLOCK(ic); 692} 693