ieee80211_node.c revision 1.1
1 /*- 2 * Copyright (c) 2001 Atsushi Onoe 3 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * Alternatively, this software may be distributed under the terms of the 18 * GNU General Public License ("GPL") version 2 as published by the Free 19 * Software Foundation. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.6 2003/08/19 22:17:03 sam Exp $"); 35 36 #include "opt_inet.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/mbuf.h> 41 #include <sys/malloc.h> 42 #include <sys/kernel.h> 43 #include <sys/socket.h> 44 #include <sys/sockio.h> 45 #include <sys/endian.h> 46 #include <sys/errno.h> 47 #include <sys/bus.h> 48 #include <sys/proc.h> 49 #include <sys/sysctl.h> 50 51 #include <machine/atomic.h> 52 53 #include <net/if.h> 54 #include <net/if_dl.h> 55 #include <net/if_media.h> 56 #include <net/if_arp.h> 57 #include <net/ethernet.h> 58 #include <net/if_llc.h> 59 60 #include <net80211/ieee80211_var.h> 61 62 #include <net/bpf.h> 63 64 #ifdef INET 65 #include <netinet/in.h> 66 #include <netinet/if_ether.h> 67 #endif 68 69 static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); 70 static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); 71 static void ieee80211_node_copy(struct ieee80211com *, 72 struct ieee80211_node *, const struct ieee80211_node *); 73 static void ieee80211_setup_node(struct ieee80211com *ic, 74 struct ieee80211_node *ni, u_int8_t *macaddr); 75 static void _ieee80211_free_node(struct ieee80211com *, 76 struct ieee80211_node *); 77 78 void 79 ieee80211_node_attach(struct ifnet *ifp) 80 { 81 struct ieee80211com *ic = (void *)ifp; 82 83 /* XXX need unit */ 84 mtx_init(&ic->ic_nodelock, ifp->if_name, "802.11 node table", MTX_DEF); 85 TAILQ_INIT(&ic->ic_node); 86 ic->ic_node_alloc = ieee80211_node_alloc; 87 ic->ic_node_free = ieee80211_node_free; 88 ic->ic_node_copy = ieee80211_node_copy; 89 } 90 91 void 92 ieee80211_node_lateattach(struct ifnet *ifp) 93 { 94 struct ieee80211com *ic = (void *)ifp; 95 96 ic->ic_bss = (*ic->ic_node_alloc)(ic); 97 KASSERT(ic->ic_bss != NULL, ("unable to setup inital BSS node")); 98 ic->ic_bss->ni_chan = IEEE80211_CHAN_ANYC; 99 } 100 101 void 102 ieee80211_node_detach(struct ifnet *ifp) 103 { 104 struct ieee80211com *ic = (void *)ifp; 105 106 if (ic->ic_bss != NULL) 107 (*ic->ic_node_free)(ic, ic->ic_bss); 108 ieee80211_free_allnodes(ic); 109 mtx_destroy(&ic->ic_nodelock); 110 } 111 112 /* 113 * AP scanning support. 114 */ 115 116 /* 117 * Initialize the active channel set based on the set 118 * of available channels and the current PHY mode. 119 */ 120 static void 121 ieee80211_reset_scan(struct ifnet *ifp) 122 { 123 struct ieee80211com *ic = (void *)ifp; 124 125 memcpy(ic->ic_chan_scan, ic->ic_chan_active, 126 sizeof(ic->ic_chan_active)); 127 /* NB: hack, setup so next_scan starts with the first channel */ 128 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) 129 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; 130 } 131 132 /* 133 * Begin an active scan. 134 */ 135 void 136 ieee80211_begin_scan(struct ifnet *ifp) 137 { 138 struct ieee80211com *ic = (void *)ifp; 139 140 /* 141 * In all but hostap mode scanning starts off in 142 * an active mode before switching to passive. 143 */ 144 if (ic->ic_opmode != IEEE80211_M_HOSTAP) 145 ic->ic_flags |= IEEE80211_F_ASCAN; 146 if (ifp->if_flags & IFF_DEBUG) 147 if_printf(ifp, "begin %s scan\n", 148 (ic->ic_flags & IEEE80211_F_ASCAN) ? 149 "active" : "passive"); 150 /* 151 * Clear scan state and flush any previously seen 152 * AP's. Note that the latter assumes we don't act 153 * as both an AP and a station, otherwise we'll 154 * potentially flush state of stations associated 155 * with us. 156 */ 157 ieee80211_reset_scan(ifp); 158 ieee80211_free_allnodes(ic); 159 160 /* Scan the next channel. */ 161 ieee80211_next_scan(ifp); 162 } 163 164 /* 165 * Switch to the next channel marked for scanning. 166 */ 167 void 168 ieee80211_next_scan(struct ifnet *ifp) 169 { 170 struct ieee80211com *ic = (void *)ifp; 171 struct ieee80211_channel *chan; 172 173 chan = ic->ic_bss->ni_chan; 174 for (;;) { 175 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) 176 chan = &ic->ic_channels[0]; 177 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { 178 /* 179 * Honor channels marked passive-only 180 * during an active scan. 181 */ 182 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || 183 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) 184 break; 185 } 186 if (chan == ic->ic_bss->ni_chan) { 187 ieee80211_end_scan(ifp); 188 return; 189 } 190 } 191 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); 192 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", 193 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), 194 ieee80211_chan2ieee(ic, chan))); 195 ic->ic_bss->ni_chan = chan; 196 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); 197 } 198 199 void 200 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) 201 { 202 struct ieee80211_node *ni; 203 struct ifnet *ifp = &ic->ic_if; 204 205 ni = ic->ic_bss; 206 if (ifp->if_flags & IFF_DEBUG) 207 if_printf(ifp, "creating ibss\n"); 208 ic->ic_flags |= IEEE80211_F_SIBSS; 209 ni->ni_chan = chan; 210 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; 211 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); 212 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); 213 if (ic->ic_opmode == IEEE80211_M_IBSS) 214 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ 215 ni->ni_esslen = ic->ic_des_esslen; 216 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); 217 ni->ni_rssi = 0; 218 ni->ni_rstamp = 0; 219 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 220 ni->ni_intval = ic->ic_lintval; 221 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 222 if (ic->ic_flags & IEEE80211_F_WEPON) 223 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 224 if (ic->ic_phytype == IEEE80211_T_FH) { 225 ni->ni_fhdwell = 200; /* XXX */ 226 ni->ni_fhindex = 1; 227 } 228 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 229 } 230 231 /* 232 * Complete a scan of potential channels. 233 */ 234 void 235 ieee80211_end_scan(struct ifnet *ifp) 236 { 237 struct ieee80211com *ic = (void *)ifp; 238 struct ieee80211_node *ni, *nextbs, *selbs; 239 u_int8_t rate; 240 int i, fail; 241 242 ic->ic_flags &= ~IEEE80211_F_ASCAN; 243 ni = TAILQ_FIRST(&ic->ic_node); 244 245 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 246 /* XXX off stack? */ 247 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 248 /* 249 * The passive scan to look for existing AP's completed, 250 * select a channel to camp on. Identify the channels 251 * that already have one or more AP's and try to locate 252 * an unnoccupied one. If that fails, pick a random 253 * channel from the active set. 254 */ 255 for (; ni != NULL; ni = nextbs) { 256 ieee80211_ref_node(ni); 257 nextbs = TAILQ_NEXT(ni, ni_list); 258 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 259 ieee80211_free_node(ic, ni); 260 } 261 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 262 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 263 break; 264 if (i == IEEE80211_CHAN_MAX) { 265 fail = arc4random() & 3; /* random 0-3 */ 266 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 267 if (isset(ic->ic_chan_active, i) && fail-- == 0) 268 break; 269 } 270 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 271 return; 272 } 273 if (ni == NULL) { 274 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 275 notfound: 276 if (ic->ic_opmode == IEEE80211_M_IBSS && 277 (ic->ic_flags & IEEE80211_F_IBSSON) && 278 ic->ic_des_esslen != 0) { 279 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 280 return; 281 } 282 /* 283 * Reset the list of channels to scan and start again. 284 */ 285 ieee80211_reset_scan(ifp); 286 ieee80211_next_scan(ifp); 287 return; 288 } 289 selbs = NULL; 290 if (ifp->if_flags & IFF_DEBUG) 291 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); 292 for (; ni != NULL; ni = nextbs) { 293 ieee80211_ref_node(ni); 294 nextbs = TAILQ_NEXT(ni, ni_list); 295 if (ni->ni_fails) { 296 /* 297 * The configuration of the access points may change 298 * during my scan. So delete the entry for the AP 299 * and retry to associate if there is another beacon. 300 */ 301 if (ni->ni_fails++ > 2) 302 ieee80211_free_node(ic, ni); 303 continue; 304 } 305 fail = 0; 306 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 307 fail |= 0x01; 308 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 309 ni->ni_chan != ic->ic_des_chan) 310 fail |= 0x01; 311 if (ic->ic_opmode == IEEE80211_M_IBSS) { 312 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 313 fail |= 0x02; 314 } else { 315 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 316 fail |= 0x02; 317 } 318 if (ic->ic_flags & IEEE80211_F_WEPON) { 319 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 320 fail |= 0x04; 321 } else { 322 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 323 fail |= 0x04; 324 } 325 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 326 if (rate & IEEE80211_RATE_BASIC) 327 fail |= 0x08; 328 if (ic->ic_des_esslen != 0 && 329 (ni->ni_esslen != ic->ic_des_esslen || 330 memcmp(ni->ni_essid, ic->ic_des_essid, 331 ic->ic_des_esslen != 0))) 332 fail |= 0x10; 333 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 334 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 335 fail |= 0x20; 336 if (ifp->if_flags & IFF_DEBUG) { 337 printf(" %c %s", fail ? '-' : '+', 338 ether_sprintf(ni->ni_macaddr)); 339 printf(" %s%c", ether_sprintf(ni->ni_bssid), 340 fail & 0x20 ? '!' : ' '); 341 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 342 fail & 0x01 ? '!' : ' '); 343 printf(" %+4d", ni->ni_rssi); 344 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 345 fail & 0x08 ? '!' : ' '); 346 printf(" %4s%c", 347 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 348 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 349 "????", 350 fail & 0x02 ? '!' : ' '); 351 printf(" %3s%c ", 352 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 353 "wep" : "no", 354 fail & 0x04 ? '!' : ' '); 355 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 356 printf("%s\n", fail & 0x10 ? "!" : ""); 357 } 358 if (!fail) { 359 if (selbs == NULL) 360 selbs = ni; 361 else if (ni->ni_rssi > selbs->ni_rssi) { 362 ieee80211_unref_node(&selbs); 363 selbs = ni; 364 } else 365 ieee80211_unref_node(&ni); 366 } else { 367 ieee80211_unref_node(&ni); 368 } 369 } 370 if (selbs == NULL) 371 goto notfound; 372 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 373 if (ic->ic_opmode == IEEE80211_M_IBSS) { 374 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 375 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 376 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 377 selbs->ni_fails++; 378 ieee80211_unref_node(&selbs); 379 goto notfound; 380 } 381 ieee80211_unref_node(&selbs); 382 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 383 } else { 384 ieee80211_unref_node(&selbs); 385 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 386 } 387 } 388 389 static struct ieee80211_node * 390 ieee80211_node_alloc(struct ieee80211com *ic) 391 { 392 return malloc(sizeof(struct ieee80211_node), M_DEVBUF, 393 M_NOWAIT | M_ZERO); 394 } 395 396 static void 397 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 398 { 399 free(ni, M_DEVBUF); 400 } 401 402 static void 403 ieee80211_node_copy(struct ieee80211com *ic, 404 struct ieee80211_node *dst, const struct ieee80211_node *src) 405 { 406 *dst = *src; 407 } 408 409 static void 410 ieee80211_setup_node(struct ieee80211com *ic, 411 struct ieee80211_node *ni, u_int8_t *macaddr) 412 { 413 int hash; 414 415 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 416 hash = IEEE80211_NODE_HASH(macaddr); 417 ni->ni_refcnt = 1; /* mark referenced */ 418 mtx_lock(&ic->ic_nodelock); 419 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 420 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 421 /* 422 * Note we don't enable the inactive timer when acting 423 * as a station. Nodes created in this mode represent 424 * AP's identified while scanning. If we time them out 425 * then several things happen: we can't return the data 426 * to users to show the list of AP's we encountered, and 427 * more importantly, we'll incorrectly deauthenticate 428 * ourself because the inactivity timer will kick us off. 429 */ 430 if (ic->ic_opmode != IEEE80211_M_STA) 431 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 432 mtx_unlock(&ic->ic_nodelock); 433 } 434 435 struct ieee80211_node * 436 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 437 { 438 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 439 if (ni != NULL) 440 ieee80211_setup_node(ic, ni, macaddr); 441 return ni; 442 } 443 444 struct ieee80211_node * 445 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 446 { 447 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 448 if (ni != NULL) { 449 memcpy(ni, ic->ic_bss, sizeof(struct ieee80211_node)); 450 ieee80211_setup_node(ic, ni, macaddr); 451 } 452 return ni; 453 } 454 455 struct ieee80211_node * 456 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 457 { 458 struct ieee80211_node *ni; 459 int hash; 460 461 hash = IEEE80211_NODE_HASH(macaddr); 462 mtx_lock(&ic->ic_nodelock); 463 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 464 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 465 atomic_add_int(&ni->ni_refcnt, 1); /* mark referenced */ 466 break; 467 } 468 } 469 mtx_unlock(&ic->ic_nodelock); 470 return ni; 471 } 472 473 /* 474 * Like find but search based on the channel too. 475 */ 476 struct ieee80211_node * 477 ieee80211_lookup_node(struct ieee80211com *ic, 478 u_int8_t *macaddr, struct ieee80211_channel *chan) 479 { 480 struct ieee80211_node *ni; 481 int hash; 482 483 hash = IEEE80211_NODE_HASH(macaddr); 484 mtx_lock(&ic->ic_nodelock); 485 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 486 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && ni->ni_chan == chan) { 487 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 488 break; 489 } 490 } 491 mtx_unlock(&ic->ic_nodelock); 492 return ni; 493 } 494 495 static void 496 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 497 { 498 KASSERT(ni != ic->ic_bss, ("freeing bss node")); 499 500 TAILQ_REMOVE(&ic->ic_node, ni, ni_list); 501 LIST_REMOVE(ni, ni_hash); 502 if (TAILQ_EMPTY(&ic->ic_node)) 503 ic->ic_inact_timer = 0; 504 (*ic->ic_node_free)(ic, ni); 505 } 506 507 void 508 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 509 { 510 KASSERT(ni != ic->ic_bss, ("freeing ic_bss")); 511 512 /* XXX need equivalent of atomic_dec_and_test */ 513 atomic_subtract_int(&ni->ni_refcnt, 1); 514 if (atomic_cmpset_int(&ni->ni_refcnt, 0, 1)) { 515 mtx_lock(&ic->ic_nodelock); 516 _ieee80211_free_node(ic, ni); 517 mtx_unlock(&ic->ic_nodelock); 518 } 519 } 520 521 void 522 ieee80211_free_allnodes(struct ieee80211com *ic) 523 { 524 struct ieee80211_node *ni; 525 526 mtx_lock(&ic->ic_nodelock); 527 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 528 _ieee80211_free_node(ic, ni); 529 mtx_unlock(&ic->ic_nodelock); 530 } 531 532 void 533 ieee80211_timeout_nodes(struct ieee80211com *ic) 534 { 535 struct ieee80211_node *ni, *nextbs; 536 537 mtx_lock(&ic->ic_nodelock); 538 for (ni = TAILQ_FIRST(&ic->ic_node); ni != NULL;) { 539 if (++ni->ni_inact > IEEE80211_INACT_MAX) { 540 IEEE80211_DPRINTF(("station %s timed out " 541 "due to inactivity (%u secs)\n", 542 ether_sprintf(ni->ni_macaddr), 543 ni->ni_inact)); 544 nextbs = TAILQ_NEXT(ni, ni_list); 545 /* 546 * Send a deauthenticate frame. 547 */ 548 IEEE80211_SEND_MGMT(ic, ni, 549 IEEE80211_FC0_SUBTYPE_DEAUTH, 550 IEEE80211_REASON_AUTH_EXPIRE); 551 ieee80211_free_node(ic, ni); 552 ni = nextbs; 553 } else 554 ni = TAILQ_NEXT(ni, ni_list); 555 } 556 if (!TAILQ_EMPTY(&ic->ic_node)) 557 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 558 mtx_unlock(&ic->ic_nodelock); 559 } 560 561 void 562 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 563 { 564 struct ieee80211_node *ni; 565 566 mtx_lock(&ic->ic_nodelock); 567 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 568 (*f)(arg, ni); 569 mtx_unlock(&ic->ic_nodelock); 570 } 571
Indexes created Tue Sep 23 07:09:52 GMT 2025