ieee80211_node.c revision 1.20
1 /* $NetBSD: ieee80211_node.c,v 1.20 2004/07/23 08:25:25 mycroft 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 1.20 2004/07/23 08:25:25 mycroft 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 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, ("begin %s scan\n", 182 (ic->ic_flags & IEEE80211_F_ASCAN) ? "active" : "passive")); 183 /* 184 * Clear scan state and flush any previously seen 185 * AP's. Note that the latter assumes we don't act 186 * as both an AP and a station, otherwise we'll 187 * potentially flush state of stations associated 188 * with us. 189 */ 190 ieee80211_reset_scan(ifp); 191 ieee80211_free_allnodes(ic); 192 193 /* Scan the next channel. */ 194 ieee80211_next_scan(ifp); 195 } 196 197 /* 198 * Switch to the next channel marked for scanning. 199 */ 200 void 201 ieee80211_next_scan(struct ifnet *ifp) 202 { 203 struct ieee80211com *ic = (void *)ifp; 204 struct ieee80211_channel *chan; 205 206 chan = ic->ic_bss->ni_chan; 207 for (;;) { 208 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 209 chan = &ic->ic_channels[0]; 210 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 211 /* 212 * Honor channels marked passive-only 213 * during an active scan. 214 */ 215 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 216 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 217 break; 218 } 219 if (chan == ic->ic_bss->ni_chan) { 220 ieee80211_end_scan(ifp); 221 return; 222 } 223 } 224 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 225 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, 226 ("%s: chan %d->%d\n", __func__, 227 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 228 ieee80211_chan2ieee(ic, chan))); 229 ic->ic_bss->ni_chan = chan; 230 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 231 } 232 233 void 234 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 235 { 236 struct ieee80211_node *ni; 237 238 ni = ic->ic_bss; 239 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, ("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 if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0) 247 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid); 248 else 249 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 250 } 251 ni->ni_esslen = ic->ic_des_esslen; 252 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 253 ni->ni_rssi = 0; 254 ni->ni_rstamp = 0; 255 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 256 ni->ni_intval = ic->ic_lintval; 257 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 258 if (ic->ic_flags & IEEE80211_F_WEPON) 259 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 260 if (ic->ic_phytype == IEEE80211_T_FH) { 261 ni->ni_fhdwell = 200; /* XXX */ 262 ni->ni_fhindex = 1; 263 } 264 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 265 } 266 267 int 268 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni) 269 { 270 u_int8_t rate; 271 int fail; 272 273 fail = 0; 274 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 275 fail |= 0x01; 276 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 277 ni->ni_chan != ic->ic_des_chan) 278 fail |= 0x01; 279 if (ic->ic_opmode == IEEE80211_M_IBSS) { 280 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 281 fail |= 0x02; 282 } else { 283 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 284 fail |= 0x02; 285 } 286 if (ic->ic_flags & IEEE80211_F_WEPON) { 287 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 288 fail |= 0x04; 289 } else { 290 /* XXX does this mean privacy is supported or required? */ 291 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 292 fail |= 0x04; 293 } 294 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 295 if (rate & IEEE80211_RATE_BASIC) 296 fail |= 0x08; 297 if (ic->ic_des_esslen != 0 && 298 (ni->ni_esslen != ic->ic_des_esslen || 299 memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) 300 fail |= 0x10; 301 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 302 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 303 fail |= 0x20; 304 #ifdef IEEE80211_DEBUG 305 if (ic->ic_if.if_flags & IFF_DEBUG) { 306 printf(" %c %s", fail ? '-' : '+', 307 ether_sprintf(ni->ni_macaddr)); 308 printf(" %s%c", ether_sprintf(ni->ni_bssid), 309 fail & 0x20 ? '!' : ' '); 310 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 311 fail & 0x01 ? '!' : ' '); 312 printf(" %+4d", ni->ni_rssi); 313 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 314 fail & 0x08 ? '!' : ' '); 315 printf(" %4s%c", 316 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 317 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 318 "????", 319 fail & 0x02 ? '!' : ' '); 320 printf(" %3s%c ", 321 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 322 "wep" : "no", 323 fail & 0x04 ? '!' : ' '); 324 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 325 printf("%s\n", fail & 0x10 ? "!" : ""); 326 } 327 #endif 328 return fail; 329 } 330 331 /* 332 * Complete a scan of potential channels. 333 */ 334 void 335 ieee80211_end_scan(struct ifnet *ifp) 336 { 337 struct ieee80211com *ic = (void *)ifp; 338 struct ieee80211_node *ni, *nextbs, *selbs; 339 int i, fail; 340 341 ic->ic_flags &= ~IEEE80211_F_ASCAN; 342 ni = TAILQ_FIRST(&ic->ic_node); 343 344 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 345 /* XXX off stack? */ 346 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 347 /* 348 * The passive scan to look for existing AP's completed, 349 * select a channel to camp on. Identify the channels 350 * that already have one or more AP's and try to locate 351 * an unnoccupied one. If that fails, pick a random 352 * channel from the active set. 353 */ 354 for (; ni != NULL; ni = nextbs) { 355 ieee80211_ref_node(ni); 356 nextbs = TAILQ_NEXT(ni, ni_list); 357 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 358 ieee80211_free_node(ic, ni); 359 } 360 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 361 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 362 break; 363 if (i == IEEE80211_CHAN_MAX) { 364 fail = arc4random() & 3; /* random 0-3 */ 365 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 366 if (isset(ic->ic_chan_active, i) && fail-- == 0) 367 break; 368 } 369 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 370 return; 371 } 372 if (ni == NULL) { 373 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, 374 ("%s: no scan candidate\n", __func__)); 375 notfound: 376 if (ic->ic_opmode == IEEE80211_M_IBSS && 377 (ic->ic_flags & IEEE80211_F_IBSSON) && 378 ic->ic_des_esslen != 0) { 379 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 380 return; 381 } 382 /* 383 * Reset the list of channels to scan and start again. 384 */ 385 ieee80211_reset_scan(ifp); 386 ieee80211_next_scan(ifp); 387 return; 388 } 389 selbs = NULL; 390 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, 391 ("\tmacaddr bssid chan rssi rate flag wep essid\n")); 392 for (; ni != NULL; ni = nextbs) { 393 ieee80211_ref_node(ni); 394 nextbs = TAILQ_NEXT(ni, ni_list); 395 if (ni->ni_fails) { 396 /* 397 * The configuration of the access points may change 398 * during my scan. So delete the entry for the AP 399 * and retry to associate if there is another beacon. 400 */ 401 if (ni->ni_fails++ > 2) 402 ieee80211_free_node(ic, ni); 403 continue; 404 } 405 if (ieee80211_match_bss(ic, ni) == 0) { 406 if (selbs == NULL) 407 selbs = ni; 408 else if (ni->ni_rssi > selbs->ni_rssi) { 409 ieee80211_unref_node(&selbs); 410 selbs = ni; 411 } else 412 ieee80211_unref_node(&ni); 413 } else { 414 ieee80211_unref_node(&ni); 415 } 416 } 417 if (selbs == NULL) 418 goto notfound; 419 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 420 if (ic->ic_opmode == IEEE80211_M_IBSS) { 421 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 422 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 423 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 424 selbs->ni_fails++; 425 ieee80211_unref_node(&selbs); 426 goto notfound; 427 } 428 ieee80211_unref_node(&selbs); 429 /* 430 * Discard scan set; the nodes have a refcnt of zero 431 * and have not asked the driver to setup private 432 * node state. Let them be repopulated on demand either 433 * through transmission (ieee80211_find_txnode) or receipt 434 * of a probe response (to be added). 435 */ 436 ieee80211_free_allnodes(ic); 437 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 438 } else { 439 ieee80211_unref_node(&selbs); 440 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 441 } 442 } 443 444 int 445 ieee80211_get_rate(struct ieee80211com *ic) 446 { 447 u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE]; 448 int rate; 449 450 rates = &ic->ic_bss->ni_rates.rs_rates; 451 452 if (ic->ic_fixed_rate != -1) 453 rate = (*rates)[ic->ic_fixed_rate]; 454 else if (ic->ic_state == IEEE80211_S_RUN) 455 rate = (*rates)[ic->ic_bss->ni_txrate]; 456 else 457 rate = 0; 458 459 return rate & IEEE80211_RATE_VAL; 460 } 461 462 static struct ieee80211_node * 463 ieee80211_node_alloc(struct ieee80211com *ic) 464 { 465 struct ieee80211_node *ni; 466 MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node), 467 M_80211_NODE, M_NOWAIT | M_ZERO); 468 return ni; 469 } 470 471 static void 472 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 473 { 474 if (ni->ni_challenge != NULL) { 475 FREE(ni->ni_challenge, M_DEVBUF); 476 ni->ni_challenge = NULL; 477 } 478 FREE(ni, M_80211_NODE); 479 } 480 481 static void 482 ieee80211_node_copy(struct ieee80211com *ic, 483 struct ieee80211_node *dst, const struct ieee80211_node *src) 484 { 485 *dst = *src; 486 dst->ni_challenge = NULL; 487 } 488 489 static u_int8_t 490 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) 491 { 492 return ni->ni_rssi; 493 } 494 495 static void 496 ieee80211_setup_node(struct ieee80211com *ic, 497 struct ieee80211_node *ni, u_int8_t *macaddr) 498 { 499 int hash; 500 ieee80211_node_critsec_decl(s); 501 502 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 503 hash = IEEE80211_NODE_HASH(macaddr); 504 ni->ni_refcnt = 1; /* mark referenced */ 505 ieee80211_node_critsec_begin(ic, s); 506 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 507 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 508 /* 509 * Note we don't enable the inactive timer when acting 510 * as a station. Nodes created in this mode represent 511 * AP's identified while scanning. If we time them out 512 * then several things happen: we can't return the data 513 * to users to show the list of AP's we encountered, and 514 * more importantly, we'll incorrectly deauthenticate 515 * ourself because the inactivity timer will kick us off. 516 */ 517 if (ic->ic_opmode != IEEE80211_M_STA) 518 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 519 ieee80211_node_critsec_end(ic, s); 520 } 521 522 struct ieee80211_node * 523 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 524 { 525 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 526 if (ni != NULL) 527 ieee80211_setup_node(ic, ni, macaddr); 528 else 529 ic->ic_stats.is_rx_nodealloc++; 530 return ni; 531 } 532 533 struct ieee80211_node * 534 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 535 { 536 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 537 if (ni != NULL) { 538 ieee80211_setup_node(ic, ni, macaddr); 539 /* 540 * Inherit from ic_bss. 541 */ 542 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid); 543 ni->ni_chan = ic->ic_bss->ni_chan; 544 } else 545 ic->ic_stats.is_rx_nodealloc++; 546 return ni; 547 } 548 549 static struct ieee80211_node * 550 _ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 551 { 552 struct ieee80211_node *ni; 553 int hash; 554 555 #ifdef __FreeBSD__ 556 IEEE80211_NODE_LOCK_ASSERT(ic); 557 #endif /* __FreeBSD__ */ 558 559 hash = IEEE80211_NODE_HASH(macaddr); 560 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 561 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 562 ieee80211_node_incref(ni); /* mark referenced */ 563 return ni; 564 } 565 } 566 return NULL; 567 } 568 569 struct ieee80211_node * 570 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 571 { 572 struct ieee80211_node *ni; 573 ieee80211_node_critsec_decl(s); 574 575 ieee80211_node_critsec_begin(ic, s); 576 ni = _ieee80211_find_node(ic, macaddr); 577 ieee80211_node_critsec_end(ic, s); 578 return ni; 579 } 580 581 /* 582 * Return a reference to the appropriate node for sending 583 * a data frame. This handles node discovery in adhoc networks. 584 */ 585 struct ieee80211_node * 586 ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr) 587 { 588 struct ieee80211_node *ni; 589 ieee80211_node_critsec_decl(s); 590 591 /* 592 * The destination address should be in the node table 593 * unless we are operating in station mode or this is a 594 * multicast/broadcast frame. 595 */ 596 if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr)) 597 return ic->ic_bss; 598 599 /* XXX can't hold lock across dup_bss 'cuz of recursive locking */ 600 ieee80211_node_critsec_begin(ic, s); 601 ni = _ieee80211_find_node(ic, macaddr); 602 ieee80211_node_critsec_end(ic, s); 603 if (ni == NULL && 604 (ic->ic_opmode == IEEE80211_M_IBSS || 605 ic->ic_opmode == IEEE80211_M_AHDEMO)) { 606 /* 607 * Fake up a node; this handles node discovery in 608 * adhoc mode. Note that for the driver's benefit 609 * we we treat this like an association so the driver 610 * has an opportunity to setup it's private state. 611 * 612 * XXX need better way to handle this; issue probe 613 * request so we can deduce rate set, etc. 614 */ 615 ni = ieee80211_dup_bss(ic, macaddr); 616 if (ni != NULL) { 617 /* XXX no rate negotiation; just dup */ 618 ni->ni_rates = ic->ic_bss->ni_rates; 619 if (ic->ic_newassoc) 620 (*ic->ic_newassoc)(ic, ni, 1); 621 } 622 } 623 return ni; 624 } 625 626 /* 627 * For some types of packet and for some operating modes, it is 628 * desirable to process a Rx packet using its sender's node-record 629 * instead of the BSS record, when that is possible. 630 * 631 * - AP mode: keep a node-record for every authenticated/associated 632 * station *in the BSS*. For future use, we also track neighboring 633 * APs, since they might belong to the same ESSID. 634 * 635 * - IBSS mode: keep a node-record for every station *in the BSS*. 636 * 637 * - monitor mode: keep a node-record for every sender, regardless 638 * of BSS. 639 * 640 * - STA mode: the only available node-record is the BSS record, 641 * ic->ic_bss. 642 * 643 * Of all the 802.11 Control packets, only the node-records for 644 * RTS packets node-record can be looked up. 645 * 646 * Return non-zero if the packet's node-record is kept, zero 647 * otherwise. 648 */ 649 static __inline int 650 ieee80211_needs_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh, 651 u_int8_t **bssid) 652 { 653 struct ieee80211_node *bss = ic->ic_bss; 654 int monitor, rc = 0; 655 656 monitor = (ic->ic_opmode == IEEE80211_M_MONITOR); 657 658 *bssid = NULL; 659 660 switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) { 661 case IEEE80211_FC0_TYPE_CTL: 662 if (!monitor) 663 break; 664 return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == 665 IEEE80211_FC0_SUBTYPE_RTS; 666 case IEEE80211_FC0_TYPE_MGT: 667 *bssid = wh->i_addr3; 668 switch (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) { 669 case IEEE80211_FC0_SUBTYPE_BEACON: 670 case IEEE80211_FC0_SUBTYPE_PROBE_RESP: 671 rc = 1; 672 break; 673 default: 674 break; 675 } 676 break; 677 case IEEE80211_FC0_TYPE_DATA: 678 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 679 case IEEE80211_FC1_DIR_NODS: 680 *bssid = wh->i_addr3; 681 if (ic->ic_opmode == IEEE80211_M_IBSS || 682 ic->ic_opmode == IEEE80211_M_AHDEMO) 683 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 684 break; 685 case IEEE80211_FC1_DIR_TODS: 686 *bssid = wh->i_addr1; 687 if (ic->ic_opmode == IEEE80211_M_HOSTAP) 688 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); 689 break; 690 case IEEE80211_FC1_DIR_FROMDS: 691 case IEEE80211_FC1_DIR_DSTODS: 692 *bssid = wh->i_addr2; 693 rc = (ic->ic_opmode == IEEE80211_M_HOSTAP); 694 break; 695 } 696 break; 697 } 698 return monitor || rc; 699 } 700 701 struct ieee80211_node * 702 ieee80211_find_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh) 703 { 704 struct ieee80211_node *ni; 705 const static u_int8_t zero[IEEE80211_ADDR_LEN]; 706 u_int8_t *bssid; 707 ieee80211_node_critsec_decl(s); 708 709 if (!ieee80211_needs_rxnode(ic, wh, &bssid)) 710 return ieee80211_ref_node(ic->ic_bss); 711 712 ieee80211_node_critsec_begin(ic, s); 713 ni = _ieee80211_find_node(ic, wh->i_addr2); 714 ieee80211_node_critsec_end(ic, s); 715 716 if (ni != NULL) 717 return ni; 718 719 if (ic->ic_opmode == IEEE80211_M_HOSTAP) 720 return ieee80211_ref_node(ic->ic_bss); 721 722 /* XXX see remarks in ieee80211_find_txnode */ 723 /* XXX no rate negotiation; just dup */ 724 if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL) 725 return ieee80211_ref_node(ic->ic_bss); 726 727 IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero); 728 729 ni->ni_rates = ic->ic_bss->ni_rates; 730 if (ic->ic_newassoc) 731 (*ic->ic_newassoc)(ic, ni, 1); 732 733 IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE, 734 ("%s: faked-up node %p for %s\n", __func__, ni, 735 ether_sprintf(wh->i_addr2))); 736 737 return ieee80211_ref_node(ni); 738 } 739 740 /* 741 * Like find but search based on the channel too. 742 */ 743 struct ieee80211_node * 744 ieee80211_lookup_node(struct ieee80211com *ic, 745 u_int8_t *macaddr, struct ieee80211_channel *chan) 746 { 747 struct ieee80211_node *ni; 748 int hash; 749 ieee80211_node_critsec_decl(s); 750 751 hash = IEEE80211_NODE_HASH(macaddr); 752 ieee80211_node_critsec_begin(ic, s); 753 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 754 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && 755 ni->ni_chan == chan) { 756 ieee80211_node_incref(ni);/* mark referenced */ 757 break; 758 } 759 } 760 ieee80211_node_critsec_end(ic, s); 761 return ni; 762 } 763 764 static void 765 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 766 { 767 IASSERT(ni != ic->ic_bss, ("freeing bss node")); 768 769 IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap); 770 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 771 LIST_REMOVE(ni, ni_hash); 772 if (!IF_IS_EMPTY(&ni->ni_savedq)) { 773 IF_PURGE(&ni->ni_savedq); 774 if (ic->ic_set_tim) 775 ic->ic_set_tim(ic, ni->ni_associd, 0); 776 } 777 if (TAILQ_EMPTY(&ic->ic_node)) 778 ic->ic_inact_timer = 0; 779 (*ic->ic_node_free)(ic, ni); 780 } 781 782 void 783 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 784 { 785 ieee80211_node_critsec_decl(s); 786 787 IASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 788 789 if (ieee80211_node_decref(ni) == 0) { 790 ieee80211_node_critsec_begin(ic, s); 791 _ieee80211_free_node(ic, ni); 792 ieee80211_node_critsec_end(ic, s); 793 } 794 } 795 796 void 797 ieee80211_free_allnodes(struct ieee80211com *ic) 798 { 799 struct ieee80211_node *ni; 800 ieee80211_node_critsec_decl(s); 801 802 ieee80211_node_critsec_begin(ic, s); 803 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 804 _ieee80211_free_node(ic, ni); 805 ieee80211_node_critsec_end(ic, s); 806 } 807 808 /* 809 * Timeout inactive nodes. Note that we cannot hold the node 810 * lock while sending a frame as this would lead to a LOR. 811 * Instead we use a generation number to mark nodes that we've 812 * scanned and drop the lock and restart a scan if we have to 813 * time out a node. Since we are single-threaded by virtue of 814 * controlling the inactivity timer we can be sure this will 815 * process each node only once. 816 */ 817 void 818 ieee80211_timeout_nodes(struct ieee80211com *ic) 819 { 820 struct ieee80211_node *ni; 821 ieee80211_node_critsec_decl(s); 822 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ 823 824 restart: 825 ieee80211_node_critsec_begin(ic, s); 826 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { 827 if (ni->ni_scangen == gen) /* previously handled */ 828 continue; 829 ni->ni_scangen = gen; 830 if (++ni->ni_inact > ieee80211_inact_max) { 831 IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE, 832 ("station %s timed out due to inactivity (%u secs)\n", 833 ether_sprintf(ni->ni_macaddr), 834 ni->ni_inact)); 835 /* 836 * Send a deauthenticate frame. 837 * 838 * Drop the node lock before sending the 839 * deauthentication frame in case the driver takes 840 * a lock, as this will result in a LOR between the 841 * node lock and the driver lock. 842 */ 843 ieee80211_node_critsec_end(ic, s); 844 IEEE80211_SEND_MGMT(ic, ni, 845 IEEE80211_FC0_SUBTYPE_DEAUTH, 846 IEEE80211_REASON_AUTH_EXPIRE); 847 ieee80211_free_node(ic, ni); 848 ic->ic_stats.is_node_timeout++; 849 goto restart; 850 } 851 } 852 if (!TAILQ_EMPTY(&ic->ic_node)) 853 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 854 ieee80211_node_critsec_end(ic, s); 855 } 856 857 void 858 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 859 { 860 struct ieee80211_node *ni; 861 ieee80211_node_critsec_decl(s); 862 863 ieee80211_node_critsec_begin(ic, s); 864 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 865 (*f)(arg, ni); 866 ieee80211_node_critsec_end(ic, s); 867 } 868
Indexes created Tue Sep 23 14:10:03 GMT 2025