ieee80211_node.c revision 118887
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: head/sys/net80211/ieee80211_node.c 118887 2003-08-13 22:09:44Z sam $"); 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 69static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); 70static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); 71static void ieee80211_node_copy(struct ieee80211com *, 72 struct ieee80211_node *, const struct ieee80211_node *); 73static void ieee80211_setup_node(struct ieee80211com *ic, 74 struct ieee80211_node *ni, u_int8_t *macaddr); 75static void _ieee80211_free_node(struct ieee80211com *, 76 struct ieee80211_node *); 77 78void 79ieee80211_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 91void 92ieee80211_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 101void 102ieee80211_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 */ 120static void 121ieee80211_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 */ 135void 136ieee80211_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 */ 167void 168ieee80211_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 199void 200ieee80211_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 ni->ni_rantenna = 0; 220 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); 221 ni->ni_intval = ic->ic_lintval; 222 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; 223 if (ic->ic_flags & IEEE80211_F_WEPON) 224 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; 225 if (ic->ic_phytype == IEEE80211_T_FH) { 226 ni->ni_fhdwell = 200; /* XXX */ 227 ni->ni_fhindex = 1; 228 } 229 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 230} 231 232/* 233 * Complete a scan of potential channels. 234 */ 235void 236ieee80211_end_scan(struct ifnet *ifp) 237{ 238 struct ieee80211com *ic = (void *)ifp; 239 struct ieee80211_node *ni, *nextbs, *selbs; 240 u_int8_t rate; 241 int i, fail; 242 243 ic->ic_flags &= ~IEEE80211_F_ASCAN; 244 ni = TAILQ_FIRST(&ic->ic_node); 245 246 if (ic->ic_opmode == IEEE80211_M_HOSTAP) { 247 /* XXX off stack? */ 248 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; 249 /* 250 * The passive scan to look for existing AP's completed, 251 * select a channel to camp on. Identify the channels 252 * that already have one or more AP's and try to locate 253 * an unnoccupied one. If that fails, pick a random 254 * channel from the active set. 255 */ 256 for (; ni != NULL; ni = nextbs) { 257 ieee80211_ref_node(ni); 258 nextbs = TAILQ_NEXT(ni, ni_list); 259 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); 260 ieee80211_free_node(ic, ni); 261 } 262 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 263 if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) 264 break; 265 if (i == IEEE80211_CHAN_MAX) { 266 fail = arc4random() & 3; /* random 0-3 */ 267 for (i = 0; i < IEEE80211_CHAN_MAX; i++) 268 if (isset(ic->ic_chan_active, i) && fail-- == 0) 269 break; 270 } 271 ieee80211_create_ibss(ic, &ic->ic_channels[i]); 272 return; 273 } 274 if (ni == NULL) { 275 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); 276 notfound: 277 if (ic->ic_opmode == IEEE80211_M_IBSS && 278 (ic->ic_flags & IEEE80211_F_IBSSON) && 279 ic->ic_des_esslen != 0) { 280 ieee80211_create_ibss(ic, ic->ic_ibss_chan); 281 return; 282 } 283 /* 284 * Reset the list of channels to scan and start again. 285 */ 286 ieee80211_reset_scan(ifp); 287 ieee80211_next_scan(ifp); 288 return; 289 } 290 selbs = NULL; 291 if (ifp->if_flags & IFF_DEBUG) 292 if_printf(ifp, "\tmacaddr bssid chan rssi rate ant flag wep essid\n"); 293 for (; ni != NULL; ni = nextbs) { 294 ieee80211_ref_node(ni); 295 nextbs = TAILQ_NEXT(ni, ni_list); 296 if (ni->ni_fails) { 297 /* 298 * The configuration of the access points may change 299 * during my scan. So delete the entry for the AP 300 * and retry to associate if there is another beacon. 301 */ 302 if (ni->ni_fails++ > 2) 303 ieee80211_free_node(ic, ni); 304 continue; 305 } 306 fail = 0; 307 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) 308 fail |= 0x01; 309 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && 310 ni->ni_chan != ic->ic_des_chan) 311 fail |= 0x01; 312 if (ic->ic_opmode == IEEE80211_M_IBSS) { 313 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 314 fail |= 0x02; 315 } else { 316 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) 317 fail |= 0x02; 318 } 319 if (ic->ic_flags & IEEE80211_F_WEPON) { 320 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 321 fail |= 0x04; 322 } else { 323 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) 324 fail |= 0x04; 325 } 326 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); 327 if (rate & IEEE80211_RATE_BASIC) 328 fail |= 0x08; 329 if (ic->ic_des_esslen != 0 && 330 (ni->ni_esslen != ic->ic_des_esslen || 331 memcmp(ni->ni_essid, ic->ic_des_essid, 332 ic->ic_des_esslen != 0))) 333 fail |= 0x10; 334 if ((ic->ic_flags & IEEE80211_F_DESBSSID) && 335 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) 336 fail |= 0x20; 337 if (ifp->if_flags & IFF_DEBUG) { 338 printf(" %c %s", fail ? '-' : '+', 339 ether_sprintf(ni->ni_macaddr)); 340 printf(" %s%c", ether_sprintf(ni->ni_bssid), 341 fail & 0x20 ? '!' : ' '); 342 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), 343 fail & 0x01 ? '!' : ' '); 344 printf(" %+4d", ni->ni_rssi); 345 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 346 fail & 0x08 ? '!' : ' '); 347 printf(" %3d", ni->ni_rantenna); 348 printf(" %4s%c", 349 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 350 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 351 "????", 352 fail & 0x02 ? '!' : ' '); 353 printf(" %3s%c ", 354 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 355 "wep" : "no", 356 fail & 0x04 ? '!' : ' '); 357 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); 358 printf("%s\n", fail & 0x10 ? "!" : ""); 359 } 360 if (!fail) { 361 if (selbs == NULL) 362 selbs = ni; 363 else if (ni->ni_rssi > selbs->ni_rssi) { 364 ieee80211_unref_node(&selbs); 365 selbs = ni; 366 } else 367 ieee80211_unref_node(&ni); 368 } else { 369 ieee80211_unref_node(&ni); 370 } 371 } 372 if (selbs == NULL) 373 goto notfound; 374 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); 375 if (ic->ic_opmode == IEEE80211_M_IBSS) { 376 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | 377 IEEE80211_F_DONEGO | IEEE80211_F_DODEL); 378 if (ic->ic_bss->ni_rates.rs_nrates == 0) { 379 selbs->ni_fails++; 380 ieee80211_unref_node(&selbs); 381 goto notfound; 382 } 383 ieee80211_unref_node(&selbs); 384 ieee80211_new_state(ic, IEEE80211_S_RUN, -1); 385 } else { 386 ieee80211_unref_node(&selbs); 387 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); 388 } 389} 390 391static struct ieee80211_node * 392ieee80211_node_alloc(struct ieee80211com *ic) 393{ 394 return malloc(sizeof(struct ieee80211_node), M_DEVBUF, 395 M_NOWAIT | M_ZERO); 396} 397 398static void 399ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) 400{ 401 free(ni, M_DEVBUF); 402} 403 404static void 405ieee80211_node_copy(struct ieee80211com *ic, 406 struct ieee80211_node *dst, const struct ieee80211_node *src) 407{ 408 *dst = *src; 409} 410 411static void 412ieee80211_setup_node(struct ieee80211com *ic, 413 struct ieee80211_node *ni, u_int8_t *macaddr) 414{ 415 int hash; 416 417 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); 418 hash = IEEE80211_NODE_HASH(macaddr); 419 ni->ni_refcnt = 1; /* mark referenced */ 420 mtx_lock(&ic->ic_nodelock); 421 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); 422 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); 423 /* 424 * Note we don't enable the inactive timer when acting 425 * as a station. Nodes created in this mode represent 426 * AP's identified while scanning. If we time them out 427 * then several things happen: we can't return the data 428 * to users to show the list of AP's we encountered, and 429 * more importantly, we'll incorrectly deauthenticate 430 * ourself because the inactivity timer will kick us off. 431 */ 432 if (ic->ic_opmode != IEEE80211_M_STA) 433 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 434 mtx_unlock(&ic->ic_nodelock); 435} 436 437struct ieee80211_node * 438ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr) 439{ 440 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 441 if (ni != NULL) 442 ieee80211_setup_node(ic, ni, macaddr); 443 return ni; 444} 445 446struct ieee80211_node * 447ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr) 448{ 449 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); 450 if (ni != NULL) { 451 memcpy(ni, ic->ic_bss, sizeof(struct ieee80211_node)); 452 ieee80211_setup_node(ic, ni, macaddr); 453 } 454 return ni; 455} 456 457struct ieee80211_node * 458ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr) 459{ 460 struct ieee80211_node *ni; 461 int hash; 462 463 hash = IEEE80211_NODE_HASH(macaddr); 464 mtx_lock(&ic->ic_nodelock); 465 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 466 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { 467 atomic_add_int(&ni->ni_refcnt, 1); /* mark referenced */ 468 break; 469 } 470 } 471 mtx_unlock(&ic->ic_nodelock); 472 return ni; 473} 474 475/* 476 * Like find but search based on the channel too. 477 */ 478struct ieee80211_node * 479ieee80211_lookup_node(struct ieee80211com *ic, 480 u_int8_t *macaddr, struct ieee80211_channel *chan) 481{ 482 struct ieee80211_node *ni; 483 int hash; 484 485 hash = IEEE80211_NODE_HASH(macaddr); 486 mtx_lock(&ic->ic_nodelock); 487 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { 488 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && ni->ni_chan == chan) { 489 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ 490 break; 491 } 492 } 493 mtx_unlock(&ic->ic_nodelock); 494 return ni; 495} 496 497static void 498_ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 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 507void 508ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) 509{ 510 /* XXX need equivalent of atomic_dec_and_test */ 511 atomic_subtract_int(&ni->ni_refcnt, 1); 512 if (atomic_cmpset_int(&ni->ni_refcnt, 0, 1)) { 513 mtx_lock(&ic->ic_nodelock); 514 _ieee80211_free_node(ic, ni); 515 mtx_unlock(&ic->ic_nodelock); 516 } 517} 518 519void 520ieee80211_free_allnodes(struct ieee80211com *ic) 521{ 522 struct ieee80211_node *ni; 523 524 mtx_lock(&ic->ic_nodelock); 525 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) 526 _ieee80211_free_node(ic, ni); 527 mtx_unlock(&ic->ic_nodelock); 528} 529 530void 531ieee80211_timeout_nodes(struct ieee80211com *ic) 532{ 533 struct ieee80211_node *ni, *nextbs; 534 535 mtx_lock(&ic->ic_nodelock); 536 for (ni = TAILQ_FIRST(&ic->ic_node); ni != NULL;) { 537 if (++ni->ni_inact <= IEEE80211_INACT_MAX) { 538 ni = TAILQ_NEXT(ni, ni_list); 539 continue; 540 } 541 /* NB: don't honor reference count */ 542 IEEE80211_DPRINTF(("station %s timed out " 543 "due to inactivity (%u secs)\n", 544 ether_sprintf(ni->ni_macaddr), 545 ni->ni_inact)); 546 nextbs = TAILQ_NEXT(ni, ni_list); 547 IEEE80211_SEND_MGMT(ic, ni, 548 IEEE80211_FC0_SUBTYPE_DEAUTH, 549 IEEE80211_REASON_AUTH_EXPIRE); 550 _ieee80211_free_node(ic, ni); 551 ni = nextbs; 552 } 553 if (!TAILQ_EMPTY(&ic->ic_node)) 554 ic->ic_inact_timer = IEEE80211_INACT_WAIT; 555 mtx_unlock(&ic->ic_nodelock); 556} 557 558void 559ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) 560{ 561 struct ieee80211_node *ni; 562 563 mtx_lock(&ic->ic_nodelock); 564 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) 565 (*f)(arg, ni); 566 mtx_unlock(&ic->ic_nodelock); 567} 568