ieee80211_node.c revision 1.10
1 /* $NetBSD: ieee80211_node.c,v 1.10 2004/01/13 23:37:30 dyoung Exp $ */ 2 /*- 3 * Copyright (c) 2001 Atsushi Onoe 4 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * Alternatively, this software may be distributed under the terms of the 19 * GNU General Public License ("GPL") version 2 as published by the Free 20 * Software Foundation. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #ifdef __FreeBSD__ 36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.13 2003/11/09 23:36:46 sam Exp $"); 37 #else 38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_node.c,v 1.10 2004/01/13 23:37:30 dyoung Exp $"); 39 #endif 40 41 #include "opt_inet.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/malloc.h> 47 #include <sys/kernel.h> 48 #include <sys/socket.h> 49 #include <sys/sockio.h> 50 #include <sys/endian.h> 51 #include <sys/errno.h> 52 #ifdef __FreeBSD__ 53 #include <sys/bus.h> 54 #endif 55 #include <sys/proc.h> 56 #include <sys/sysctl.h> 57 58 #ifdef __FreeBSD__ 59 #include <machine/atomic.h> 60 #endif 61 62 #include <net/if.h> 63 #include <net/if_dl.h> 64 #include <net/if_media.h> 65 #include <net/if_arp.h> 66 #ifdef __FreeBSD__ 67 #include <net/ethernet.h> 68 #else 69 #include <net/if_ether.h> 70 #endif 71 #include <net/if_llc.h> 72 73 #include <net80211/ieee80211_var.h> 74 #include <net80211/ieee80211_compat.h> 75 76 #include <net/bpf.h> 77 78 #ifdef INET 79 #include <netinet/in.h> 80 #ifdef __FreeBSD__ 81 #include <netinet/if_ether.h> 82 #else 83 #include <net/if_ether.h> 84 #endif 85 #endif 86 87 static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); 88 static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); 89 static void ieee80211_node_copy(struct ieee80211com *, 90 struct ieee80211_node *, const struct ieee80211_node *); 91 static u_int8_t ieee80211_node_getrssi(struct ieee80211com *, 92 struct ieee80211_node *); 93 94 static void ieee80211_setup_node(struct ieee80211com *ic, 95 struct ieee80211_node *ni, u_int8_t *macaddr); 96 static void _ieee80211_free_node(struct ieee80211com *, 97 struct ieee80211_node *); 98 99 MALLOC_DEFINE(M_80211_NODE, "node", "802.11 node state"); 100 101 void 102 ieee80211_node_attach(struct ifnet *ifp) 103 { 104 struct ieee80211com *ic = (void *)ifp; 105 106 #ifdef __FreeBSD__ 107 /* XXX need unit */ 108 IEEE80211_NODE_LOCK_INIT(ic, ifp->if_xname); 109 #endif 110 TAILQ_INIT(&ic->ic_node); 111 ic->ic_node_alloc = ieee80211_node_alloc; 112 ic->ic_node_free = ieee80211_node_free; 113 ic->ic_node_copy = ieee80211_node_copy; 114 ic->ic_node_getrssi = ieee80211_node_getrssi; 115 ic->ic_scangen = 1; 116 } 117 118 void 119 ieee80211_node_lateattach(struct ifnet *ifp) 120 { 121 struct ieee80211com *ic = (void *)ifp; 122 123 ic->ic_bss = (*ic->ic_node_alloc)(ic); 124 IASSERT(ic->ic_bss != NULL, ("unable to setup inital BSS node")); 125 ic->ic_bss->ni_chan = IEEE80211_CHAN_ANYC; 126 } 127 128 void 129 ieee80211_node_detach(struct ifnet *ifp) 130 { 131 struct ieee80211com *ic = (void *)ifp; 132 133 if (ic->ic_bss != NULL) 134 (*ic->ic_node_free)(ic, ic->ic_bss); 135 ieee80211_free_allnodes(ic); 136 #ifdef __FreeBSD__ 137 IEEE80211_NODE_LOCK_DESTROY(ic); 138 #endif 139 } 140 141 /* 142 * AP scanning support. 143 */ 144 145 /* 146 * Initialize the active channel set based on the set 147 * of available channels and the current PHY mode. 148 */ 149 static void 150 ieee80211_reset_scan(struct ifnet *ifp) 151 { 152 struct ieee80211com *ic = (void *)ifp; 153 154 memcpy(ic->ic_chan_scan, ic->ic_chan_active, 155 sizeof(ic->ic_chan_active)); 156 /* NB: hack, setup so next_scan starts with the first channel */ 157 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) 158 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; 159 } 160 161 /* 162 * Begin an active scan. 163 */ 164 void 165 ieee80211_begin_scan(struct ifnet *ifp) 166 { 167 struct ieee80211com *ic = (void *)ifp; 168 169 /* 170 * In all but hostap mode scanning starts off in 171 * an active mode before switching to passive. 172 */ 173 if (ic->ic_opmode != IEEE80211_M_HOSTAP) { 174 ic->ic_flags |= IEEE80211_F_ASCAN; 175 ic->ic_stats.is_scan_active++; 176 } else 177 ic->ic_stats.is_scan_passive++; 178 if (ifp->if_flags & IFF_DEBUG) 179 if_printf(ifp, "begin %s scan\n", 180 (ic->ic_flags & IEEE80211_F_ASCAN) ? 181 "active" : "passive"); 182 /* 183 * Clear scan state and flush any previously seen 184 * AP's. Note that the latter assumes we don't act 185 * as both an AP and a station, otherwise we'll 186 * potentially flush state of stations associated 187 * with us. 188 */ 189 ieee80211_reset_scan(ifp); 190 ieee80211_free_allnodes(ic); 191 192 /* Scan the next channel. */ 193 ieee80211_next_scan(ifp); 194 } 195 196 /* 197 * Switch to the next channel marked for scanning. 198 */ 199 void 200 ieee80211_next_scan(struct ifnet *ifp) 201 { 202 struct ieee80211com *ic = (void *)ifp; 203 struct ieee80211_channel *chan; 204 205 chan = ic->ic_bss->ni_chan; 206 for (;;) { 207 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 208 chan = &ic->ic_channels[0]; 209 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 210 /* 211 * Honor channels marked passive-only 212 * during an active scan. 213 */ 214 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 215 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 216 break; 217 } 218 if (chan == ic->ic_bss->ni_chan) { 219 ieee80211_end_scan(ifp); 220 return; 221 } 222 } 223 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 224 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", 225 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 226 ieee80211_chan2ieee(ic, chan))); 227 ic->ic_bss->ni_chan = chan; 228 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 229 } 230 231 void 232 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 233 { 234 struct ieee80211_node *ni; 235 struct ifnet *ifp = &ic->ic_if; 236 237 ni = ic->ic_bss; 238 if (ifp->if_flags & IFF_DEBUG) 239 if_printf(ifp, "creating ibss\n"); 240 ic->ic_flags |= IEEE80211_F_SIBSS; 241 ni->ni_chan = chan; 242 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; 243 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); 244 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); 245 if (ic->ic_opmode == IEEE80211_M_IBSS) 246 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 247 ni->ni_esslen = ic->ic_des_esslen; 248 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 249 ni->ni_rssi = 0; 250 ni->ni_rstamp = 0; 251 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 252 ni->ni_intval = ic->ic_lintval; 253 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 254 if (ic->ic_flags & IEEE80211_F_WEPON) 255 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 256 if (ic->ic_phytype == IEEE80211_T_FH) { 257 ni->ni_fhdwell = 200; /* XXX */ 258 ni->ni_fhindex = 1; 259 } 260 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 261 } 262 263 int 264 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni) 265 { 266 struct ifnet *ifp = &ic->ic_if; 267 u_int8_t rate; 268 int fail; 269 270 fail = 0; 271 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 272 fail |= 0x01; 273 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 274 ni->ni_chan != ic->ic_des_chan) 275 fail |= 0x01; 276 if (ic->ic_opmode == IEEE80211_M_IBSS) { 277 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 278 fail |= 0x02; 279 } else { 280 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 281 fail |= 0x02; 282 } 283 if (ic->ic_flags & IEEE80211_F_WEPON) { 284 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 285 fail |= 0x04; 286 } else { 287 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 288 fail |= 0x04; 289 } 290 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 291 if (rate & IEEE80211_RATE_BASIC) 292 fail |= 0x08; 293 if (ic->ic_des_esslen != 0 && 294 (ni->ni_esslen != ic->ic_des_esslen || 295 memcmp(ni->ni_essid, ic->ic_des_essid, 296 ic->ic_des_esslen != 0))) 297 fail |= 0x10; 298 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 299 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 300 fail |= 0x20; 301 if (ifp->if_flags & IFF_DEBUG) { 302 printf(" %c %s", fail ? '-' : '+', 303 ether_sprintf(ni->ni_macaddr)); 304 printf(" %s%c", ether_sprintf(ni->ni_bssid), 305 fail & 0x20 ? '!' : ' '); 306 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 307 fail & 0x01 ? '!' : ' '); 308 printf(" %+4d", ni->ni_rssi); 309 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 310 fail & 0x08 ? '!' : ' '); 311 printf(" %4s%c", 312 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 313 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 314 "????", 315 fail & 0x02 ? '!' : ' '); 316 printf(" %3s%c ", 317 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 318 "wep" : "no", 319 fail & 0x04 ? '!' : ' '); 320 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 321 printf("%s\n", fail & 0x10 ? "!" : ""); 322 } 323 return fail; 324 } 325 326 /* 327 * Complete a scan of potential channels. 328 */ 329 void 330 ieee80211_end_scan(struct ifnet *ifp) 331 { 332 struct ieee80211com *ic = (void *)ifp; 333 struct ieee80211_node *ni, *nextbs, *selbs; 334 int i, fail; 335 336 ic->ic_flags &= ~IEEE80211_F_ASCAN; 337 ni = TAILQ_FIRST(&ic->ic_node); 338 339 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 340 /* XXX off stack? */ 341 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 342 /* 343 * The passive scan to look for existing AP's completed, 344 * select a channel to camp on. Identify the channels 345 * that already have one or more AP's and try to locate 346 * an unnoccupied one. If that fails, pick a random 347 * channel from the active set. 348 */ 349 for (; ni != NULL; ni = nextbs) { 350 ieee80211_ref_node(ni); 351 nextbs = TAILQ_NEXT(ni, ni_list); 352 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 353 ieee80211_free_node(ic, ni); 354 } 355 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 356 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 357 break; 358 if (i == IEEE80211_CHAN_MAX) { 359 fail = arc4random() & 3; /* random 0-3 */ 360 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 361 if (isset(ic->ic_chan_active, i) && fail-- == 0) 362 break; 363 } 364 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 365 return; 366 } 367 if (ni == NULL) { 368 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 369 notfound: 370 if (ic->ic_opmode == IEEE80211_M_IBSS && 371 (ic->ic_flags & IEEE80211_F_IBSSON) && 372 ic->ic_des_esslen != 0) { 373 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 374 return; 375 } 376 /* 377 * Reset the list of channels to scan and start again. 378 */ 379 ieee80211_reset_scan(ifp); 380 ieee80211_next_scan(ifp); 381 return; 382 } 383 selbs = NULL; 384 if (ifp->if_flags & IFF_DEBUG) 385 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); 386 for (; ni != NULL; ni = nextbs) { 387 ieee80211_ref_node(ni); 388 nextbs = TAILQ_NEXT(ni, ni_list); 389 if (ni->ni_fails) { 390 /* 391 * The configuration of the access points may change 392 * during my scan. So delete the entry for the AP 393 * and retry to associate if there is another beacon. 394 */ 395 if (ni->ni_fails++ > 2) 396 ieee80211_free_node(ic, ni); 397 continue; 398 } 399 if (ieee80211_match_bss(ic, ni) == 0) { 400 if (selbs == NULL) 401 selbs = ni; 402 else if (ni->ni_rssi > selbs->ni_rssi) { 403 ieee80211_unref_node(&selbs); 404 selbs = ni; 405 } else 406 ieee80211_unref_node(&ni); 407 } else { 408 ieee80211_unref_node(&ni); 409 } 410 } 411 if (selbs == NULL) 412 goto notfound; 413 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 414 if (ic->ic_opmode == IEEE80211_M_IBSS) { 415 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 416 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 417 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 418 selbs->ni_fails++; 419 ieee80211_unref_node(&selbs); 420 goto notfound; 421 } 422 ieee80211_unref_node(&selbs); 423 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 424 } else { 425 ieee80211_unref_node(&selbs); 426 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 427 } 428 } 429 430 int 431 ieee80211_get_rate(struct ieee80211com *ic) 432 { 433 u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE]; 434 int rate; 435 436 rates = &ic->ic_bss->ni_rates.rs_rates; 437 438 if (ic->ic_fixed_rate != -1) 439 rate = (*rates)[ic->ic_fixed_rate]; 440 else if (ic->ic_state == IEEE80211_S_RUN) 441 rate = (*rates)[ic->ic_bss->ni_txrate]; 442 else 443 rate = 0; 444 445 return rate & IEEE80211_RATE_VAL; 446 } 447 448 static struct ieee80211_node * 449 ieee80211_node_alloc(struct ieee80211com *ic) 450 { 451 return malloc(sizeof(struct ieee80211_node), M_80211_NODE, 452 M_NOWAIT | M_ZERO); 453 } 454 455 static void 456 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 457 { 458 if (ni->ni_challenge != NULL) { 459 free(ni->ni_challenge, M_DEVBUF); 460 ni->ni_challenge = NULL; 461 } 462 free(ni, M_80211_NODE); 463 } 464 465 static void 466 ieee80211_node_copy(struct ieee80211com *ic, 467 struct ieee80211_node *dst, const struct ieee80211_node *src) 468 { 469 *dst = *src; 470 dst->ni_challenge = NULL; 471 } 472 473 static u_int8_t 474 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) 475 { 476 return ni->ni_rssi; 477 } 478 479 static void 480 ieee80211_setup_node(struct ieee80211com *ic, 481 struct ieee80211_node *ni, u_int8_t *macaddr) 482 { 483 int hash; 484 ieee80211_node_critsec_decl(s); 485 486 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 487 hash = IEEE80211_NODE_HASH(macaddr); 488 ni->ni_refcnt = 1; /* mark referenced */ 489 ieee80211_node_critsec_begin(ic, s); 490 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 491 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 492 /* 493 * Note we don't enable the inactive timer when acting 494 * as a station. Nodes created in this mode represent 495 * AP's identified while scanning. If we time them out 496 * then several things happen: we can't return the data 497 * to users to show the list of AP's we encountered, and 498 * more importantly, we'll incorrectly deauthenticate 499 * ourself because the inactivity timer will kick us off. 500 */ 501 if (ic->ic_opmode != IEEE80211_M_STA) 502 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 503 ieee80211_node_critsec_end(ic, s); 504 } 505 506 struct ieee80211_node * 507 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 508 { 509 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 510 if (ni != NULL) 511 ieee80211_setup_node(ic, ni, macaddr); 512 return ni; 513 } 514 515 struct ieee80211_node * 516 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 517 { 518 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 519 if (ni != NULL) { 520 memcpy(ni, ic->ic_bss, sizeof(struct ieee80211_node)); 521 ieee80211_setup_node(ic, ni, macaddr); 522 } 523 return ni; 524 } 525 526 struct ieee80211_node * 527 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 528 { 529 struct ieee80211_node *ni; 530 int hash; 531 ieee80211_node_critsec_decl(s); 532 533 hash = IEEE80211_NODE_HASH(macaddr); 534 ieee80211_node_critsec_begin(ic, s); 535 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 536 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 537 ieee80211_node_incref(ni); /* mark referenced */ 538 break; 539 } 540 } 541 ieee80211_node_critsec_end(ic, s); 542 return ni; 543 } 544 545 struct ieee80211_node * 546 ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr) 547 { 548 struct ieee80211_node *ni; 549 ieee80211_node_critsec_decl(s); 550 551 /* 552 * The destination address should be in the node table 553 * unless this is a multicast/broadcast frames or we are 554 * in station mode. 555 */ 556 if (IEEE80211_IS_MULTICAST(macaddr) || ic->ic_opmode == IEEE80211_M_STA) 557 return ic->ic_bss; 558 559 ieee80211_node_critsec_begin(ic, s); 560 ni = ieee80211_find_node(ic, macaddr); 561 if (ni == NULL) { 562 if (ic->ic_opmode != IEEE80211_M_MONITOR) 563 ni = ieee80211_dup_bss(ic, macaddr); 564 IEEE80211_DPRINTF(("%s: faked-up node %p for %s\n", 565 __func__, ni, ether_sprintf(macaddr))); 566 if (ni == NULL) { 567 ieee80211_node_critsec_end(ic, s); 568 /* ic->ic_stats.st_tx_nonode++; XXX statistic */ 569 return NULL; 570 } 571 (void)ieee80211_ref_node(ni); 572 } 573 ieee80211_node_critsec_end(ic, s); 574 return ni; 575 } 576 577 /* 578 * For some types of packet and for some operating modes, it is 579 * desirable to process a Rx packet using its sender's node-record 580 * instead of the BSS record, when that is possible. 581 * 582 * - AP mode: it is desirable to keep a node-record for every 583 * authenticated/associated station *in the BSS*. For future use, 584 * we also track neighboring APs, since they might belong to the 585 * same ESSID. 586 * 587 * - IBSS mode: it is desirable to keep a node-record for every 588 * station *in the BSS*. 589 * 590 * - monitor mode: it is desirable to keep a node-record for every 591 * sender, regardless of BSS. 592 * 593 * - STA mode: the only available node-record is the BSS record, 594 * ic->ic_bss. 595 * 596 * Of all the 802.11 Control packets, only the node-records for 597 * RTS packets node-record can be looked up. 598 * 599 * Return non-zero if the packet's node-record is kept, zero 600 * otherwise. 601 */ 602 static __inline int 603 ieee80211_needs_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh, 604 u_int8_t **bssid) 605 { 606 struct ieee80211_node *bss = ic->ic_bss; 607 int needsnode, rc = 0; 608 609 if (ic->ic_opmode == IEEE80211_M_STA) 610 return 0; 611 612 needsnode = (ic->ic_opmode == IEEE80211_M_MONITOR); 613 614 *bssid = NULL; 615 616 switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) { 617 case IEEE80211_FC0_TYPE_CTL: 618 return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == 619 IEEE80211_FC0_SUBTYPE_RTS; 620 621 case IEEE80211_FC0_TYPE_MGT: 622 *bssid = wh->i_addr3; 623 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 624 break; 625 case IEEE80211_FC0_TYPE_DATA: 626 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 627 case IEEE80211_FC1_DIR_NODS: 628 *bssid = wh->i_addr3; 629 if (ic->ic_opmode == IEEE80211_M_IBSS || 630 ic->ic_opmode == IEEE80211_M_AHDEMO) 631 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 632 break; 633 case IEEE80211_FC1_DIR_TODS: 634 *bssid = wh->i_addr1; 635 if (ic->ic_opmode == IEEE80211_M_HOSTAP) 636 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 637 break; 638 case IEEE80211_FC1_DIR_FROMDS: 639 case IEEE80211_FC1_DIR_DSTODS: 640 *bssid = wh->i_addr2; 641 rc = (ic->ic_opmode == IEEE80211_M_HOSTAP); 642 break; 643 } 644 break; 645 } 646 return needsnode || rc; 647 } 648 649 struct ieee80211_node * 650 ieee80211_find_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh) 651 { 652 struct ieee80211_node *ni; 653 const static u_int8_t zero[IEEE80211_ADDR_LEN]; 654 u_int8_t *bssid; 655 ieee80211_node_critsec_decl(s); 656 657 ieee80211_node_critsec_begin(ic, s); 658 659 if (!ieee80211_needs_rxnode(ic, wh, &bssid)) 660 return ieee80211_ref_node(ic->ic_bss); 661 662 ni = ieee80211_find_node(ic, wh->i_addr2); 663 664 if (ni == NULL) { 665 if (ic->ic_opmode != IEEE80211_M_HOSTAP) { 666 if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) != NULL) 667 IEEE80211_ADDR_COPY(ni->ni_bssid, 668 (bssid != NULL) ? bssid : zero); 669 670 IEEE80211_DPRINTF(("%s: faked-up node %p for %s\n", 671 __func__, ni, ether_sprintf(wh->i_addr2))); 672 } 673 ni = ieee80211_ref_node((ni == NULL) ? ic->ic_bss : ni); 674 } 675 ieee80211_node_critsec_end(ic, s); 676 IASSERT(ni != NULL, ("%s: null node", __func__)); 677 return ni; 678 } 679 680 /* 681 * Like find but search based on the channel too. 682 */ 683 struct ieee80211_node * 684 ieee80211_lookup_node(struct ieee80211com *ic, 685 u_int8_t *macaddr, struct ieee80211_channel *chan) 686 { 687 struct ieee80211_node *ni; 688 int hash; 689 ieee80211_node_critsec_decl(s); 690 691 hash = IEEE80211_NODE_HASH(macaddr); 692 ieee80211_node_critsec_begin(ic, s); 693 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 694 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && ni->ni_chan == chan) { 695 ieee80211_node_incref(ni);/* mark referenced */ 696 break; 697 } 698 } 699 ieee80211_node_critsec_end(ic, s); 700 return ni; 701 } 702 703 static void 704 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 705 { 706 IASSERT(ni != ic->ic_bss, ("freeing bss node")); 707 708 IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap); 709 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 710 LIST_REMOVE(ni, ni_hash); 711 if (!IF_IS_EMPTY(&ni->ni_savedq)) { 712 IF_PURGE(&ni->ni_savedq); 713 if (ic->ic_set_tim) 714 ic->ic_set_tim(ic, ni->ni_associd, 0); 715 } 716 if (TAILQ_EMPTY(&ic->ic_node)) 717 ic->ic_inact_timer = 0; 718 (*ic->ic_node_free)(ic, ni); 719 } 720 721 void 722 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 723 { 724 ieee80211_node_critsec_decl(s); 725 726 IASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 727 728 if (ieee80211_node_decref(ni) == 0) { 729 ieee80211_node_critsec_begin(ic, s); 730 _ieee80211_free_node(ic, ni); 731 ieee80211_node_critsec_end(ic, s); 732 } 733 } 734 735 void 736 ieee80211_free_allnodes(struct ieee80211com *ic) 737 { 738 struct ieee80211_node *ni; 739 ieee80211_node_critsec_decl(s); 740 741 ieee80211_node_critsec_begin(ic, s); 742 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 743 _ieee80211_free_node(ic, ni); 744 ieee80211_node_critsec_end(ic, s); 745 } 746 747 /* 748 * Timeout inactive nodes. Note that we cannot hold the node 749 * lock while sending a frame as this would lead to a LOR. 750 * Instead we use a generation number to mark nodes that we've 751 * scanned and drop the lock and restart a scan if we have to 752 * time out a node. Since we are single-threaded by virtue of 753 * controlling the inactivity timer we can be sure this will 754 * process each node only once. 755 */ 756 void 757 ieee80211_timeout_nodes(struct ieee80211com *ic) 758 { 759 struct ieee80211_node *ni; 760 ieee80211_node_critsec_decl(s); 761 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ 762 763 restart: 764 ieee80211_node_critsec_begin(ic, s); 765 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { 766 if (ni->ni_scangen == gen) /* previously handled */ 767 continue; 768 ni->ni_scangen = gen; 769 if (++ni->ni_inact > IEEE80211_INACT_MAX) { 770 IEEE80211_DPRINTF(("station %s timed out " 771 "due to inactivity (%u secs)\n", 772 ether_sprintf(ni->ni_macaddr), 773 ni->ni_inact)); 774 /* 775 * Send a deauthenticate frame. 776 * 777 * Drop the node lock before sending the 778 * deauthentication frame in case the driver takes 779 * a lock, as this will result in a LOR between the 780 * node lock and the driver lock. 781 */ 782 ieee80211_node_critsec_end(ic, s); 783 IEEE80211_SEND_MGMT(ic, ni, 784 IEEE80211_FC0_SUBTYPE_DEAUTH, 785 IEEE80211_REASON_AUTH_EXPIRE); 786 ieee80211_free_node(ic, ni); 787 ic->ic_stats.is_node_timeout++; 788 goto restart; 789 } 790 } 791 if (!TAILQ_EMPTY(&ic->ic_node)) 792 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 793 ieee80211_node_critsec_end(ic, s); 794 } 795 796 void 797 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 798 { 799 struct ieee80211_node *ni; 800 ieee80211_node_critsec_decl(s); 801 802 ieee80211_node_critsec_begin(ic, s); 803 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 804 (*f)(arg, ni); 805 ieee80211_node_critsec_end(ic, s); 806 } 807
Indexes created Mon Sep 22 21:09:42 GMT 2025