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 * $FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.22 2004/04/05 04:15:55 sam Exp $ 33 * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211_node.c,v 1.1 2004/07/26 16:30:17 joerg Exp $ 34 */ 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 #include <sys/thread.h> 51 #include <sys/thread2.h> 52 53 #include <machine/atomic.h> 54 55 #include <net/if.h> 56 #include <net/if_dl.h> 57 #include <net/if_media.h> 58 #include <net/if_arp.h> 59 #include <net/ethernet.h> 60 #include <net/if_llc.h> 61 62 #include <netproto/802_11/ieee80211_var.h> 63 64 #include <net/bpf.h> 65 66 #ifdef INET 67 #include <netinet/in.h> 68 #include <netinet/if_ether.h> 69 #endif 70 71 static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); 72 static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); 73 static void ieee80211_node_copy(struct ieee80211com *, 74 struct ieee80211_node *, const struct ieee80211_node *); 75 static uint8_t ieee80211_node_getrssi(struct ieee80211com *, 76 struct ieee80211_node *); 77 78 static void ieee80211_setup_node(struct ieee80211com *ic, 79 struct ieee80211_node *ni, uint8_t *macaddr); 80 static void _ieee80211_free_node(struct ieee80211com *, 81 struct ieee80211_node *); 82 83 MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state"); 84 85 void 86 ieee80211_node_attach(struct ifnet *ifp) 87 { 88 struct ieee80211com *ic = (void *)ifp; 89 90 lwkt_token_init(&ic->ic_nodetoken); 91 TAILQ_INIT(&ic->ic_node); 92 ic->ic_node_alloc = ieee80211_node_alloc; 93 ic->ic_node_free = ieee80211_node_free; 94 ic->ic_node_copy = ieee80211_node_copy; 95 ic->ic_node_getrssi = ieee80211_node_getrssi; 96 ic->ic_scangen = 1; 97 } 98 99 void 100 ieee80211_node_lateattach(struct ifnet *ifp) 101 { 102 struct ieee80211com *ic = (void *)ifp; 103 struct ieee80211_node *ni; 104 105 ni = (*ic->ic_node_alloc)(ic); 106 KASSERT(ni != NULL, ("unable to setup inital BSS node")); 107 ni->ni_chan = IEEE80211_CHAN_ANYC; 108 ic->ic_bss = ni; 109 ic->ic_txpower = IEEE80211_TXPOWER_MAX; 110 } 111 112 void 113 ieee80211_node_detach(struct ifnet *ifp) 114 { 115 struct ieee80211com *ic = (void *)ifp; 116 117 if (ic->ic_bss != NULL) 118 (*ic->ic_node_free)(ic, ic->ic_bss); 119 ieee80211_free_allnodes(ic); 120 lwkt_token_uninit(&ic->ic_nodetoken); 121 } 122 123 /* 124 * AP scanning support. 125 */ 126 127 /* 128 * Initialize the active channel set based on the set 129 * of available channels and the current PHY mode. 130 */ 131 static void 132 ieee80211_reset_scan(struct ifnet *ifp) 133 { 134 struct ieee80211com *ic = (void *)ifp; 135 136 memcpy(ic->ic_chan_scan, ic->ic_chan_active, 137 sizeof(ic->ic_chan_active)); 138 /* NB: hack, setup so next_scan starts with the first channel */ 139 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) 140 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; 141 } 142 143 /* 144 * Begin an active scan. 145 */ 146 void 147 ieee80211_begin_scan(struct ifnet *ifp) 148 { 149 struct ieee80211com *ic = (void *)ifp; 150 151 /* 152 * In all but hostap mode scanning starts off in 153 * an active mode before switching to passive. 154 */ 155 if (ic->ic_opmode != IEEE80211_M_HOSTAP) { 156 ic->ic_flags |= IEEE80211_F_ASCAN; 157 ic->ic_stats.is_scan_active++; 158 } else 159 ic->ic_stats.is_scan_passive++; 160 if (ifp->if_flags & IFF_DEBUG) 161 if_printf(ifp, "begin %s scan\n", 162 (ic->ic_flags & IEEE80211_F_ASCAN) ? 163 "active" : "passive"); 164 /* 165 * Clear scan state and flush any previously seen 166 * AP's. Note that the latter assumes we don't act 167 * as both an AP and a station, otherwise we'll 168 * potentially flush state of stations associated 169 * with us. 170 */ 171 ieee80211_reset_scan(ifp); 172 ieee80211_free_allnodes(ic); 173 174 /* Scan the next channel. */ 175 ieee80211_next_scan(ifp); 176 } 177 178 /* 179 * Switch to the next channel marked for scanning. 180 */ 181 void 182 ieee80211_next_scan(struct ifnet *ifp) 183 { 184 struct ieee80211com *ic = (void *)ifp; 185 struct ieee80211_channel *chan; 186 187 chan = ic->ic_bss->ni_chan; 188 for (;;) { 189 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 190 chan = &ic->ic_channels[0]; 191 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 192 /* 193 * Honor channels marked passive-only 194 * during an active scan. 195 */ 196 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 197 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 198 break; 199 } 200 if (chan == ic->ic_bss->ni_chan) { 201 ieee80211_end_scan(ifp); 202 return; 203 } 204 } 205 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 206 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", 207 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 208 ieee80211_chan2ieee(ic, chan))); 209 ic->ic_bss->ni_chan = chan; 210 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 211 } 212 213 void 214 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 215 { 216 struct ieee80211_node *ni; 217 struct ifnet *ifp = &ic->ic_if; 218 219 ni = ic->ic_bss; 220 if (ifp->if_flags & IFF_DEBUG) 221 if_printf(ifp, "creating ibss\n"); 222 ic->ic_flags |= IEEE80211_F_SIBSS; 223 ni->ni_chan = chan; 224 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; 225 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); 226 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); 227 if (ic->ic_opmode == IEEE80211_M_IBSS) 228 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 229 ni->ni_esslen = ic->ic_des_esslen; 230 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 231 ni->ni_rssi = 0; 232 ni->ni_rstamp = 0; 233 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 234 ni->ni_intval = ic->ic_lintval; 235 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 236 if (ic->ic_flags & IEEE80211_F_WEPON) 237 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 238 if (ic->ic_phytype == IEEE80211_T_FH) { 239 ni->ni_fhdwell = 200; /* XXX */ 240 ni->ni_fhindex = 1; 241 } 242 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 243 } 244 245 static int 246 ieee80211_match_bss(struct ifnet *ifp, struct ieee80211_node *ni) 247 { 248 struct ieee80211com *ic = (void *)ifp; 249 uint8_t rate; 250 int fail; 251 252 fail = 0; 253 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 254 fail |= 0x01; 255 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 256 ni->ni_chan != ic->ic_des_chan) 257 fail |= 0x01; 258 if (ic->ic_opmode == IEEE80211_M_IBSS) { 259 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 260 fail |= 0x02; 261 } else { 262 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 263 fail |= 0x02; 264 } 265 if (ic->ic_flags & IEEE80211_F_WEPON) { 266 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 267 fail |= 0x04; 268 } else { 269 /* XXX does this mean privacy is supported or required? */ 270 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 271 fail |= 0x04; 272 } 273 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 274 if (rate & IEEE80211_RATE_BASIC) 275 fail |= 0x08; 276 if (ic->ic_des_esslen != 0 && 277 (ni->ni_esslen != ic->ic_des_esslen || 278 memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) 279 fail |= 0x10; 280 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 281 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 282 fail |= 0x20; 283 #ifdef IEEE80211_DEBUG 284 if (ifp->if_flags & IFF_DEBUG) { 285 printf(" %c %6D", fail ? '-' : '+', ni->ni_macaddr, ":"); 286 printf(" %6D%c", ni->ni_bssid, ":", fail & 0x20 ? '!' : ' '); 287 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 288 fail & 0x01 ? '!' : ' '); 289 printf(" %+4d", ni->ni_rssi); 290 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 291 fail & 0x08 ? '!' : ' '); 292 printf(" %4s%c", 293 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 294 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 295 "????", 296 fail & 0x02 ? '!' : ' '); 297 printf(" %3s%c ", 298 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 299 "wep" : "no", 300 fail & 0x04 ? '!' : ' '); 301 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 302 printf("%s\n", fail & 0x10 ? "!" : ""); 303 } 304 #endif 305 return fail; 306 } 307 308 /* 309 * Complete a scan of potential channels. 310 */ 311 void 312 ieee80211_end_scan(struct ifnet *ifp) 313 { 314 struct ieee80211com *ic = (void *)ifp; 315 struct ieee80211_node *ni, *nextbs, *selbs; 316 int i, fail; 317 318 ic->ic_flags &= ~IEEE80211_F_ASCAN; 319 ni = TAILQ_FIRST(&ic->ic_node); 320 321 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 322 /* XXX off stack? */ 323 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 324 /* 325 * The passive scan to look for existing AP's completed, 326 * select a channel to camp on. Identify the channels 327 * that already have one or more AP's and try to locate 328 * an unnoccupied one. If that fails, pick a random 329 * channel from the active set. 330 */ 331 for (; ni != NULL; ni = nextbs) { 332 ieee80211_ref_node(ni); 333 nextbs = TAILQ_NEXT(ni, ni_list); 334 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 335 ieee80211_free_node(ic, ni); 336 } 337 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 338 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 339 break; 340 if (i == IEEE80211_CHAN_MAX) { 341 fail = arc4random() & 3; /* random 0-3 */ 342 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 343 if (isset(ic->ic_chan_active, i) && fail-- == 0) 344 break; 345 } 346 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 347 return; 348 } 349 if (ni == NULL) { 350 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 351 notfound: 352 if (ic->ic_opmode == IEEE80211_M_IBSS && 353 (ic->ic_flags & IEEE80211_F_IBSSON) && 354 ic->ic_des_esslen != 0) { 355 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 356 return; 357 } 358 /* 359 * Reset the list of channels to scan and start again. 360 */ 361 ieee80211_reset_scan(ifp); 362 ieee80211_next_scan(ifp); 363 return; 364 } 365 selbs = NULL; 366 if (ifp->if_flags & IFF_DEBUG) 367 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); 368 for (; ni != NULL; ni = nextbs) { 369 ieee80211_ref_node(ni); 370 nextbs = TAILQ_NEXT(ni, ni_list); 371 if (ni->ni_fails) { 372 /* 373 * The configuration of the access points may change 374 * during my scan. So delete the entry for the AP 375 * and retry to associate if there is another beacon. 376 */ 377 if (ni->ni_fails++ > 2) 378 ieee80211_free_node(ic, ni); 379 continue; 380 } 381 if (ieee80211_match_bss(ifp, ni) == 0) { 382 if (selbs == NULL) 383 selbs = ni; 384 else if (ni->ni_rssi > selbs->ni_rssi) { 385 ieee80211_unref_node(&selbs); 386 selbs = ni; 387 } else 388 ieee80211_unref_node(&ni); 389 } else { 390 ieee80211_unref_node(&ni); 391 } 392 } 393 if (selbs == NULL) 394 goto notfound; 395 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 396 if (ic->ic_opmode == IEEE80211_M_IBSS) { 397 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 398 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 399 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 400 selbs->ni_fails++; 401 ieee80211_unref_node(&selbs); 402 goto notfound; 403 } 404 ieee80211_unref_node(&selbs); 405 /* 406 * Discard scan set; the nodes have a refcnt of zero 407 * and have not asked the driver to setup private 408 * node state. Let them be repopulated on demand either 409 * through transmission (ieee80211_find_txnode) or receipt 410 * of a probe response (to be added). 411 */ 412 ieee80211_free_allnodes(ic); 413 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 414 } else { 415 ieee80211_unref_node(&selbs); 416 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 417 } 418 } 419 420 static struct ieee80211_node * 421 ieee80211_node_alloc(struct ieee80211com *ic) 422 { 423 struct ieee80211_node *ni; 424 MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node), 425 M_80211_NODE, M_NOWAIT | M_ZERO); 426 return ni; 427 } 428 429 static void 430 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 431 { 432 FREE(ni, M_80211_NODE); 433 } 434 435 static void 436 ieee80211_node_copy(struct ieee80211com *ic, 437 struct ieee80211_node *dst, const struct ieee80211_node *src) 438 { 439 *dst = *src; 440 } 441 442 static uint8_t 443 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) 444 { 445 return ni->ni_rssi; 446 } 447 448 static void 449 ieee80211_setup_node(struct ieee80211com *ic, 450 struct ieee80211_node *ni, uint8_t *macaddr) 451 { 452 lwkt_tokref ilock; 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 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 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 lwkt_reltoken(&ilock); 473 } 474 475 struct ieee80211_node * 476 ieee80211_alloc_node(struct ieee80211com *ic, uint8_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 } 485 486 struct ieee80211_node * 487 ieee80211_dup_bss(struct ieee80211com *ic, uint8_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 } 501 502 static struct ieee80211_node * 503 _ieee80211_find_node(struct ieee80211com *ic, uint8_t *macaddr) 504 { 505 struct ieee80211_node *ni; 506 int hash; 507 508 hash = IEEE80211_NODE_HASH(macaddr); 509 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 510 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 511 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 512 return ni; 513 } 514 } 515 return NULL; 516 } 517 518 struct ieee80211_node * 519 ieee80211_find_node(struct ieee80211com *ic, uint8_t *macaddr) 520 { 521 struct ieee80211_node *ni; 522 struct lwkt_tokref ilock; 523 524 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 525 ni = _ieee80211_find_node(ic, macaddr); 526 lwkt_reltoken(&ilock); 527 return ni; 528 } 529 530 /* 531 * Return a reference to the appropriate node for sending 532 * a data frame. This handles node discovery in adhoc networks. 533 */ 534 struct ieee80211_node * 535 ieee80211_find_txnode(struct ieee80211com *ic, uint8_t *macaddr) 536 { 537 struct ieee80211_node *ni; 538 struct lwkt_tokref ilock; 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 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 550 ni = _ieee80211_find_node(ic, macaddr); 551 lwkt_reltoken(&ilock); 552 ni = _ieee80211_find_node(ic, macaddr); 553 if (ni == NULL && 554 (ic->ic_opmode == IEEE80211_M_IBSS || 555 ic->ic_opmode == IEEE80211_M_AHDEMO)) { 556 /* 557 * Fake up a node; this handles node discovery in 558 * adhoc mode. Note that for the driver's benefit 559 * we we treat this like an association so the driver 560 * has an opportunity to setup it's private state. 561 * 562 * XXX need better way to handle this; issue probe 563 * request so we can deduce rate set, etc. 564 */ 565 ni = ieee80211_dup_bss(ic, macaddr); 566 if (ni != NULL) { 567 /* XXX no rate negotiation; just dup */ 568 ni->ni_rates = ic->ic_bss->ni_rates; 569 if (ic->ic_newassoc) 570 (*ic->ic_newassoc)(ic, ni, 1); 571 } 572 } 573 return ni; 574 } 575 576 /* 577 * Like find but search based on the channel too. 578 */ 579 struct ieee80211_node * 580 ieee80211_lookup_node(struct ieee80211com *ic, 581 uint8_t *macaddr, struct ieee80211_channel *chan) 582 { 583 struct ieee80211_node *ni; 584 int hash; 585 lwkt_tokref ilock; 586 587 hash = IEEE80211_NODE_HASH(macaddr); 588 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 589 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 590 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && 591 ni->ni_chan == chan) { 592 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 593 break; 594 } 595 } 596 lwkt_reltoken(&ilock); 597 return ni; 598 } 599 600 static void 601 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 602 { 603 KASSERT(ni != ic->ic_bss, ("freeing bss node")); 604 605 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 606 LIST_REMOVE(ni, ni_hash); 607 if (TAILQ_EMPTY(&ic->ic_node)) 608 ic->ic_inact_timer = 0; 609 (*ic->ic_node_free)(ic, ni); 610 } 611 612 void 613 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 614 { 615 lwkt_tokref ilock; 616 617 KASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 618 619 /* XXX DF atomic op */ 620 crit_enter(); 621 --ni->ni_refcnt; 622 if (ni->ni_refcnt == 0) { 623 crit_exit(); 624 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 625 _ieee80211_free_node(ic, ni); 626 lwkt_reltoken(&ilock); 627 } else { 628 crit_exit(); 629 } 630 } 631 632 void 633 ieee80211_free_allnodes(struct ieee80211com *ic) 634 { 635 struct ieee80211_node *ni; 636 lwkt_tokref ilock; 637 638 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 639 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 640 _ieee80211_free_node(ic, ni); 641 lwkt_reltoken(&ilock); 642 } 643 644 /* 645 * Timeout inactive nodes. Note that we cannot hold the node 646 * lock while sending a frame as this would lead to a LOR. 647 * Instead we use a generation number to mark nodes that we've 648 * scanned and drop the lock and restart a scan if we have to 649 * time out a node. Since we are single-threaded by virtue of 650 * controlling the inactivity timer we can be sure this will 651 * process each node only once. 652 */ 653 void 654 ieee80211_timeout_nodes(struct ieee80211com *ic) 655 { 656 struct ieee80211_node *ni; 657 lwkt_tokref ilock; 658 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ 659 660 restart: 661 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 662 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { 663 if (ni->ni_scangen == gen) /* previously handled */ 664 continue; 665 ni->ni_scangen = gen; 666 if (++ni->ni_inact > IEEE80211_INACT_MAX) { 667 IEEE80211_DPRINTF(("station %6D timed out " 668 "due to inactivity (%u secs)\n", 669 ni->ni_macaddr, ":", ni->ni_inact)); 670 /* 671 * Send a deauthenticate frame. 672 * 673 * Drop the node lock before sending the 674 * deauthentication frame in case the driver takes 675 * a lock, as this will result in a LOR between the 676 * node lock and the driver lock. 677 */ 678 lwkt_reltoken(&ilock); 679 IEEE80211_SEND_MGMT(ic, ni, 680 IEEE80211_FC0_SUBTYPE_DEAUTH, 681 IEEE80211_REASON_AUTH_EXPIRE); 682 ieee80211_free_node(ic, ni); 683 ic->ic_stats.is_node_timeout++; 684 goto restart; 685 } 686 } 687 if (!TAILQ_EMPTY(&ic->ic_node)) 688 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 689 lwkt_reltoken(&ilock); 690 } 691 692 void 693 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 694 { 695 struct ieee80211_node *ni; 696 struct lwkt_tokref ilock; 697 698 lwkt_gettoken(&ilock, &ic->ic_nodetoken); 699 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 700 (*f)(arg, ni); 701 lwkt_reltoken(&ilock); 702 } 703