ieee80211_node.c revision 1.16
1 /* $NetBSD: ieee80211_node.c,v 1.16 2004/07/23 05:19:41 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 1.22 2004/04/05 04:15:55 sam Exp $"); 37 #else 38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_node.c,v 1.16 2004/07/23 05:19:41 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, "80211node", "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 struct ieee80211_node *ni; 123 124 ni = (*ic->ic_node_alloc)(ic); 125 IASSERT(ni != NULL, ("unable to setup inital BSS node")); 126 ni->ni_chan = IEEE80211_CHAN_ANYC; 127 ic->ic_bss = ni; 128 ic->ic_txpower = IEEE80211_TXPOWER_MAX; 129 } 130 131 void 132 ieee80211_node_detach(struct ifnet *ifp) 133 { 134 struct ieee80211com *ic = (void *)ifp; 135 136 if (ic->ic_bss != NULL) 137 (*ic->ic_node_free)(ic, ic->ic_bss); 138 ieee80211_free_allnodes(ic); 139 #ifdef __FreeBSD__ 140 IEEE80211_NODE_LOCK_DESTROY(ic); 141 #endif 142 } 143 144 /* 145 * AP scanning support. 146 */ 147 148 /* 149 * Initialize the active channel set based on the set 150 * of available channels and the current PHY mode. 151 */ 152 static void 153 ieee80211_reset_scan(struct ifnet *ifp) 154 { 155 struct ieee80211com *ic = (void *)ifp; 156 157 memcpy(ic->ic_chan_scan, ic->ic_chan_active, 158 sizeof(ic->ic_chan_active)); 159 /* NB: hack, setup so next_scan starts with the first channel */ 160 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) 161 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; 162 } 163 164 /* 165 * Begin an active scan. 166 */ 167 void 168 ieee80211_begin_scan(struct ifnet *ifp) 169 { 170 struct ieee80211com *ic = (void *)ifp; 171 172 /* 173 * In all but hostap mode scanning starts off in 174 * an active mode before switching to passive. 175 */ 176 if (ic->ic_opmode != IEEE80211_M_HOSTAP) { 177 ic->ic_flags |= IEEE80211_F_ASCAN; 178 ic->ic_stats.is_scan_active++; 179 } else 180 ic->ic_stats.is_scan_passive++; 181 if (ifp->if_flags & IFF_DEBUG) 182 if_printf(ifp, "begin %s scan\n", 183 (ic->ic_flags & IEEE80211_F_ASCAN) ? 184 "active" : "passive"); 185 /* 186 * Clear scan state and flush any previously seen 187 * AP's. Note that the latter assumes we don't act 188 * as both an AP and a station, otherwise we'll 189 * potentially flush state of stations associated 190 * with us. 191 */ 192 ieee80211_reset_scan(ifp); 193 ieee80211_free_allnodes(ic); 194 195 /* Scan the next channel. */ 196 ieee80211_next_scan(ifp); 197 } 198 199 /* 200 * Switch to the next channel marked for scanning. 201 */ 202 void 203 ieee80211_next_scan(struct ifnet *ifp) 204 { 205 struct ieee80211com *ic = (void *)ifp; 206 struct ieee80211_channel *chan; 207 208 chan = ic->ic_bss->ni_chan; 209 for (;;) { 210 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 211 chan = &ic->ic_channels[0]; 212 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 213 /* 214 * Honor channels marked passive-only 215 * during an active scan. 216 */ 217 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 218 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 219 break; 220 } 221 if (chan == ic->ic_bss->ni_chan) { 222 ieee80211_end_scan(ifp); 223 return; 224 } 225 } 226 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 227 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", 228 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 229 ieee80211_chan2ieee(ic, chan))); 230 ic->ic_bss->ni_chan = chan; 231 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 232 } 233 234 void 235 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 236 { 237 struct ieee80211_node *ni; 238 struct ifnet *ifp = &ic->ic_if; 239 240 ni = ic->ic_bss; 241 if (ifp->if_flags & IFF_DEBUG) 242 if_printf(ifp, "creating ibss\n"); 243 ic->ic_flags |= IEEE80211_F_SIBSS; 244 ni->ni_chan = chan; 245 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; 246 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); 247 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); 248 if (ic->ic_opmode == IEEE80211_M_IBSS) { 249 if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0) 250 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid); 251 else 252 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 253 } 254 ni->ni_esslen = ic->ic_des_esslen; 255 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 256 ni->ni_rssi = 0; 257 ni->ni_rstamp = 0; 258 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 259 ni->ni_intval = ic->ic_lintval; 260 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 261 if (ic->ic_flags & IEEE80211_F_WEPON) 262 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 263 if (ic->ic_phytype == IEEE80211_T_FH) { 264 ni->ni_fhdwell = 200; /* XXX */ 265 ni->ni_fhindex = 1; 266 } 267 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 268 } 269 270 int 271 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni) 272 { 273 u_int8_t rate; 274 int fail; 275 276 fail = 0; 277 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 278 fail |= 0x01; 279 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 280 ni->ni_chan != ic->ic_des_chan) 281 fail |= 0x01; 282 if (ic->ic_opmode == IEEE80211_M_IBSS) { 283 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 284 fail |= 0x02; 285 } else { 286 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 287 fail |= 0x02; 288 } 289 if (ic->ic_flags & IEEE80211_F_WEPON) { 290 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 291 fail |= 0x04; 292 } else { 293 /* XXX does this mean privacy is supported or required? */ 294 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 295 fail |= 0x04; 296 } 297 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 298 if (rate & IEEE80211_RATE_BASIC) 299 fail |= 0x08; 300 if (ic->ic_des_esslen != 0 && 301 (ni->ni_esslen != ic->ic_des_esslen || 302 memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) 303 fail |= 0x10; 304 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 305 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 306 fail |= 0x20; 307 #ifdef IEEE80211_DEBUG 308 if (ic->ic_if.if_flags & IFF_DEBUG) { 309 printf(" %c %s", fail ? '-' : '+', 310 ether_sprintf(ni->ni_macaddr)); 311 printf(" %s%c", ether_sprintf(ni->ni_bssid), 312 fail & 0x20 ? '!' : ' '); 313 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 314 fail & 0x01 ? '!' : ' '); 315 printf(" %+4d", ni->ni_rssi); 316 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 317 fail & 0x08 ? '!' : ' '); 318 printf(" %4s%c", 319 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 320 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 321 "????", 322 fail & 0x02 ? '!' : ' '); 323 printf(" %3s%c ", 324 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 325 "wep" : "no", 326 fail & 0x04 ? '!' : ' '); 327 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 328 printf("%s\n", fail & 0x10 ? "!" : ""); 329 } 330 #endif 331 return fail; 332 } 333 334 /* 335 * Complete a scan of potential channels. 336 */ 337 void 338 ieee80211_end_scan(struct ifnet *ifp) 339 { 340 struct ieee80211com *ic = (void *)ifp; 341 struct ieee80211_node *ni, *nextbs, *selbs; 342 int i, fail; 343 344 ic->ic_flags &= ~IEEE80211_F_ASCAN; 345 ni = TAILQ_FIRST(&ic->ic_node); 346 347 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 348 /* XXX off stack? */ 349 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 350 /* 351 * The passive scan to look for existing AP's completed, 352 * select a channel to camp on. Identify the channels 353 * that already have one or more AP's and try to locate 354 * an unnoccupied one. If that fails, pick a random 355 * channel from the active set. 356 */ 357 for (; ni != NULL; ni = nextbs) { 358 ieee80211_ref_node(ni); 359 nextbs = TAILQ_NEXT(ni, ni_list); 360 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 361 ieee80211_free_node(ic, ni); 362 } 363 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 364 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 365 break; 366 if (i == IEEE80211_CHAN_MAX) { 367 fail = arc4random() & 3; /* random 0-3 */ 368 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 369 if (isset(ic->ic_chan_active, i) && fail-- == 0) 370 break; 371 } 372 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 373 return; 374 } 375 if (ni == NULL) { 376 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 377 notfound: 378 if (ic->ic_opmode == IEEE80211_M_IBSS && 379 (ic->ic_flags & IEEE80211_F_IBSSON) && 380 ic->ic_des_esslen != 0) { 381 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 382 return; 383 } 384 /* 385 * Reset the list of channels to scan and start again. 386 */ 387 ieee80211_reset_scan(ifp); 388 ieee80211_next_scan(ifp); 389 return; 390 } 391 selbs = NULL; 392 if (ifp->if_flags & IFF_DEBUG) 393 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); 394 for (; ni != NULL; ni = nextbs) { 395 ieee80211_ref_node(ni); 396 nextbs = TAILQ_NEXT(ni, ni_list); 397 if (ni->ni_fails) { 398 /* 399 * The configuration of the access points may change 400 * during my scan. So delete the entry for the AP 401 * and retry to associate if there is another beacon. 402 */ 403 if (ni->ni_fails++ > 2) 404 ieee80211_free_node(ic, ni); 405 continue; 406 } 407 if (ieee80211_match_bss(ic, ni) == 0) { 408 if (selbs == NULL) 409 selbs = ni; 410 else if (ni->ni_rssi > selbs->ni_rssi) { 411 ieee80211_unref_node(&selbs); 412 selbs = ni; 413 } else 414 ieee80211_unref_node(&ni); 415 } else { 416 ieee80211_unref_node(&ni); 417 } 418 } 419 if (selbs == NULL) 420 goto notfound; 421 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 422 if (ic->ic_opmode == IEEE80211_M_IBSS) { 423 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 424 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 425 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 426 selbs->ni_fails++; 427 ieee80211_unref_node(&selbs); 428 goto notfound; 429 } 430 ieee80211_unref_node(&selbs); 431 /* 432 * Discard scan set; the nodes have a refcnt of zero 433 * and have not asked the driver to setup private 434 * node state. Let them be repopulated on demand either 435 * through transmission (ieee80211_find_txnode) or receipt 436 * of a probe response (to be added). 437 */ 438 ieee80211_free_allnodes(ic); 439 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 440 } else { 441 ieee80211_unref_node(&selbs); 442 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 443 } 444 } 445 446 int 447 ieee80211_get_rate(struct ieee80211com *ic) 448 { 449 u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE]; 450 int rate; 451 452 rates = &ic->ic_bss->ni_rates.rs_rates; 453 454 if (ic->ic_fixed_rate != -1) 455 rate = (*rates)[ic->ic_fixed_rate]; 456 else if (ic->ic_state == IEEE80211_S_RUN) 457 rate = (*rates)[ic->ic_bss->ni_txrate]; 458 else 459 rate = 0; 460 461 return rate & IEEE80211_RATE_VAL; 462 } 463 464 static struct ieee80211_node * 465 ieee80211_node_alloc(struct ieee80211com *ic) 466 { 467 struct ieee80211_node *ni; 468 MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node), 469 M_80211_NODE, M_NOWAIT | M_ZERO); 470 return ni; 471 } 472 473 static void 474 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 475 { 476 if (ni->ni_challenge != NULL) { 477 FREE(ni->ni_challenge, M_DEVBUF); 478 ni->ni_challenge = NULL; 479 } 480 FREE(ni, M_80211_NODE); 481 } 482 483 static void 484 ieee80211_node_copy(struct ieee80211com *ic, 485 struct ieee80211_node *dst, const struct ieee80211_node *src) 486 { 487 *dst = *src; 488 dst->ni_challenge = NULL; 489 } 490 491 static u_int8_t 492 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) 493 { 494 return ni->ni_rssi; 495 } 496 497 static void 498 ieee80211_setup_node(struct ieee80211com *ic, 499 struct ieee80211_node *ni, u_int8_t *macaddr) 500 { 501 int hash; 502 ieee80211_node_critsec_decl(s); 503 504 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 505 hash = IEEE80211_NODE_HASH(macaddr); 506 ni->ni_refcnt = 1; /* mark referenced */ 507 ieee80211_node_critsec_begin(ic, s); 508 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 509 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 510 /* 511 * Note we don't enable the inactive timer when acting 512 * as a station. Nodes created in this mode represent 513 * AP's identified while scanning. If we time them out 514 * then several things happen: we can't return the data 515 * to users to show the list of AP's we encountered, and 516 * more importantly, we'll incorrectly deauthenticate 517 * ourself because the inactivity timer will kick us off. 518 */ 519 if (ic->ic_opmode != IEEE80211_M_STA) 520 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 521 ieee80211_node_critsec_end(ic, s); 522 } 523 524 struct ieee80211_node * 525 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 526 { 527 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 528 if (ni != NULL) 529 ieee80211_setup_node(ic, ni, macaddr); 530 else 531 ic->ic_stats.is_rx_nodealloc++; 532 return ni; 533 } 534 535 struct ieee80211_node * 536 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 537 { 538 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 539 if (ni != NULL) { 540 ieee80211_setup_node(ic, ni, macaddr); 541 /* 542 * Inherit from ic_bss. 543 */ 544 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid); 545 ni->ni_chan = ic->ic_bss->ni_chan; 546 } else 547 ic->ic_stats.is_rx_nodealloc++; 548 return ni; 549 } 550 551 static struct ieee80211_node * 552 _ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 553 { 554 struct ieee80211_node *ni; 555 int hash; 556 557 #ifdef __FreeBSD__ 558 IEEE80211_NODE_LOCK_ASSERT(ic); 559 #endif /* __FreeBSD__ */ 560 561 hash = IEEE80211_NODE_HASH(macaddr); 562 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 563 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 564 ieee80211_node_incref(ni); /* mark referenced */ 565 return ni; 566 } 567 } 568 return NULL; 569 } 570 571 struct ieee80211_node * 572 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 573 { 574 struct ieee80211_node *ni; 575 ieee80211_node_critsec_decl(s); 576 577 ieee80211_node_critsec_begin(ic, s); 578 ni = _ieee80211_find_node(ic, macaddr); 579 ieee80211_node_critsec_end(ic, s); 580 return ni; 581 } 582 583 /* 584 * Return a reference to the appropriate node for sending 585 * a data frame. This handles node discovery in adhoc networks. 586 */ 587 struct ieee80211_node * 588 ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr) 589 { 590 struct ieee80211_node *ni; 591 ieee80211_node_critsec_decl(s); 592 593 /* 594 * The destination address should be in the node table 595 * unless we are operating in station mode or this is a 596 * multicast/broadcast frame. 597 */ 598 if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr)) 599 return ic->ic_bss; 600 601 /* XXX can't hold lock across dup_bss 'cuz of recursive locking */ 602 ieee80211_node_critsec_begin(ic, s); 603 ni = _ieee80211_find_node(ic, macaddr); 604 ieee80211_node_critsec_end(ic, s); 605 if (ni == NULL && 606 (ic->ic_opmode == IEEE80211_M_IBSS || 607 ic->ic_opmode == IEEE80211_M_AHDEMO)) { 608 /* 609 * Fake up a node; this handles node discovery in 610 * adhoc mode. Note that for the driver's benefit 611 * we we treat this like an association so the driver 612 * has an opportunity to setup it's private state. 613 * 614 * XXX need better way to handle this; issue probe 615 * request so we can deduce rate set, etc. 616 */ 617 ni = ieee80211_dup_bss(ic, macaddr); 618 if (ni != NULL) { 619 /* XXX no rate negotiation; just dup */ 620 ni->ni_rates = ic->ic_bss->ni_rates; 621 if (ic->ic_newassoc) 622 (*ic->ic_newassoc)(ic, ni, 1); 623 } 624 } 625 return ni; 626 } 627 628 /* 629 * For some types of packet and for some operating modes, it is 630 * desirable to process a Rx packet using its sender's node-record 631 * instead of the BSS record, when that is possible. 632 * 633 * - AP mode: it is desirable to keep a node-record for every 634 * authenticated/associated station *in the BSS*. For future use, 635 * we also track neighboring APs, since they might belong to the 636 * same ESSID. 637 * 638 * - IBSS mode: it is desirable to keep a node-record for every 639 * station *in the BSS*. 640 * 641 * - monitor mode: it is desirable to keep a node-record for every 642 * sender, regardless of BSS. 643 * 644 * - STA mode: the only available node-record is the BSS record, 645 * ic->ic_bss. 646 * 647 * Of all the 802.11 Control packets, only the node-records for 648 * RTS packets node-record can be looked up. 649 * 650 * Return non-zero if the packet's node-record is kept, zero 651 * otherwise. 652 */ 653 static __inline int 654 ieee80211_needs_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh, 655 u_int8_t **bssid) 656 { 657 struct ieee80211_node *bss = ic->ic_bss; 658 int needsnode, rc = 0; 659 660 if (ic->ic_opmode == IEEE80211_M_STA) 661 return 0; 662 663 needsnode = (ic->ic_opmode == IEEE80211_M_MONITOR); 664 665 *bssid = NULL; 666 667 switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) { 668 case IEEE80211_FC0_TYPE_CTL: 669 return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == 670 IEEE80211_FC0_SUBTYPE_RTS; 671 672 case IEEE80211_FC0_TYPE_MGT: 673 *bssid = wh->i_addr3; 674 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 675 break; 676 case IEEE80211_FC0_TYPE_DATA: 677 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 678 case IEEE80211_FC1_DIR_NODS: 679 *bssid = wh->i_addr3; 680 if (ic->ic_opmode == IEEE80211_M_IBSS || 681 ic->ic_opmode == IEEE80211_M_AHDEMO) 682 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 683 break; 684 case IEEE80211_FC1_DIR_TODS: 685 *bssid = wh->i_addr1; 686 if (ic->ic_opmode == IEEE80211_M_HOSTAP) 687 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 688 break; 689 case IEEE80211_FC1_DIR_FROMDS: 690 case IEEE80211_FC1_DIR_DSTODS: 691 *bssid = wh->i_addr2; 692 rc = (ic->ic_opmode == IEEE80211_M_HOSTAP); 693 break; 694 } 695 break; 696 } 697 return needsnode || rc; 698 } 699 700 struct ieee80211_node * 701 ieee80211_find_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh) 702 { 703 struct ieee80211_node *ni; 704 const static u_int8_t zero[IEEE80211_ADDR_LEN]; 705 u_int8_t *bssid; 706 ieee80211_node_critsec_decl(s); 707 708 if (!ieee80211_needs_rxnode(ic, wh, &bssid)) 709 return ieee80211_ref_node(ic->ic_bss); 710 711 ieee80211_node_critsec_begin(ic, s); 712 ni = _ieee80211_find_node(ic, wh->i_addr2); 713 ieee80211_node_critsec_end(ic, s); 714 715 if (ni != NULL) 716 return ni; 717 718 if (ic->ic_opmode == IEEE80211_M_HOSTAP) 719 return ieee80211_ref_node(ic->ic_bss); 720 721 /* XXX see remarks in ieee80211_find_txnode */ 722 /* XXX no rate negotiation; just dup */ 723 if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL) 724 return ieee80211_ref_node(ic->ic_bss); 725 726 IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero); 727 728 ni->ni_rates = ic->ic_bss->ni_rates; 729 if (ic->ic_newassoc) 730 (*ic->ic_newassoc)(ic, ni, 1); 731 732 IEEE80211_DPRINTF(("%s: faked-up node %p for %s\n", __func__, ni, 733 ether_sprintf(wh->i_addr2))); 734 735 return ieee80211_ref_node(ni); 736 } 737 738 /* 739 * Like find but search based on the channel too. 740 */ 741 struct ieee80211_node * 742 ieee80211_lookup_node(struct ieee80211com *ic, 743 u_int8_t *macaddr, struct ieee80211_channel *chan) 744 { 745 struct ieee80211_node *ni; 746 int hash; 747 ieee80211_node_critsec_decl(s); 748 749 hash = IEEE80211_NODE_HASH(macaddr); 750 ieee80211_node_critsec_begin(ic, s); 751 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 752 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && 753 ni->ni_chan == chan) { 754 ieee80211_node_incref(ni);/* mark referenced */ 755 break; 756 } 757 } 758 ieee80211_node_critsec_end(ic, s); 759 return ni; 760 } 761 762 static void 763 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 764 { 765 IASSERT(ni != ic->ic_bss, ("freeing bss node")); 766 767 IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap); 768 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 769 LIST_REMOVE(ni, ni_hash); 770 if (!IF_IS_EMPTY(&ni->ni_savedq)) { 771 IF_PURGE(&ni->ni_savedq); 772 if (ic->ic_set_tim) 773 ic->ic_set_tim(ic, ni->ni_associd, 0); 774 } 775 if (TAILQ_EMPTY(&ic->ic_node)) 776 ic->ic_inact_timer = 0; 777 (*ic->ic_node_free)(ic, ni); 778 } 779 780 void 781 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 782 { 783 ieee80211_node_critsec_decl(s); 784 785 IASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 786 787 if (ieee80211_node_decref(ni) == 0) { 788 ieee80211_node_critsec_begin(ic, s); 789 _ieee80211_free_node(ic, ni); 790 ieee80211_node_critsec_end(ic, s); 791 } 792 } 793 794 void 795 ieee80211_free_allnodes(struct ieee80211com *ic) 796 { 797 struct ieee80211_node *ni; 798 ieee80211_node_critsec_decl(s); 799 800 ieee80211_node_critsec_begin(ic, s); 801 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 802 _ieee80211_free_node(ic, ni); 803 ieee80211_node_critsec_end(ic, s); 804 } 805 806 /* 807 * Timeout inactive nodes. Note that we cannot hold the node 808 * lock while sending a frame as this would lead to a LOR. 809 * Instead we use a generation number to mark nodes that we've 810 * scanned and drop the lock and restart a scan if we have to 811 * time out a node. Since we are single-threaded by virtue of 812 * controlling the inactivity timer we can be sure this will 813 * process each node only once. 814 */ 815 void 816 ieee80211_timeout_nodes(struct ieee80211com *ic) 817 { 818 struct ieee80211_node *ni; 819 ieee80211_node_critsec_decl(s); 820 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ 821 822 restart: 823 ieee80211_node_critsec_begin(ic, s); 824 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { 825 if (ni->ni_scangen == gen) /* previously handled */ 826 continue; 827 ni->ni_scangen = gen; 828 if (++ni->ni_inact > ieee80211_inact_max) { 829 IEEE80211_DPRINTF(("station %s timed out " 830 "due to inactivity (%u secs)\n", 831 ether_sprintf(ni->ni_macaddr), 832 ni->ni_inact)); 833 /* 834 * Send a deauthenticate frame. 835 * 836 * Drop the node lock before sending the 837 * deauthentication frame in case the driver takes 838 * a lock, as this will result in a LOR between the 839 * node lock and the driver lock. 840 */ 841 ieee80211_node_critsec_end(ic, s); 842 IEEE80211_SEND_MGMT(ic, ni, 843 IEEE80211_FC0_SUBTYPE_DEAUTH, 844 IEEE80211_REASON_AUTH_EXPIRE); 845 ieee80211_free_node(ic, ni); 846 ic->ic_stats.is_node_timeout++; 847 goto restart; 848 } 849 } 850 if (!TAILQ_EMPTY(&ic->ic_node)) 851 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 852 ieee80211_node_critsec_end(ic, s); 853 } 854 855 void 856 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 857 { 858 struct ieee80211_node *ni; 859 ieee80211_node_critsec_decl(s); 860 861 ieee80211_node_critsec_begin(ic, s); 862 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 863 (*f)(arg, ni); 864 ieee80211_node_critsec_end(ic, s); 865 } 866
Indexes created Mon Sep 22 13:09:51 GMT 2025