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: releng/5.3/sys/net80211/ieee80211_node.c 127876 2004-04-05 04:15:55Z 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
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 u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
74 struct ieee80211_node *);
75
76 static void ieee80211_setup_node(struct ieee80211com *ic,
77 struct ieee80211_node *ni, u_int8_t *macaddr);
78 static void _ieee80211_free_node(struct ieee80211com *,
79 struct ieee80211_node *);
80
81 MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state");
82
83 void
84 ieee80211_node_attach(struct ifnet *ifp)
85 {
86 struct ieee80211com *ic = (void *)ifp;
87
88 /* XXX need unit */
89 IEEE80211_NODE_LOCK_INIT(ic, ifp->if_xname);
90 TAILQ_INIT(&ic->ic_node);
91 ic->ic_node_alloc = ieee80211_node_alloc;
92 ic->ic_node_free = ieee80211_node_free;
93 ic->ic_node_copy = ieee80211_node_copy;
94 ic->ic_node_getrssi = ieee80211_node_getrssi;
95 ic->ic_scangen = 1;
96 }
97
98 void
99 ieee80211_node_lateattach(struct ifnet *ifp)
100 {
101 struct ieee80211com *ic = (void *)ifp;
102 struct ieee80211_node *ni;
103
104 ni = (*ic->ic_node_alloc)(ic);
105 KASSERT(ni != NULL, ("unable to setup inital BSS node"));
106 ni->ni_chan = IEEE80211_CHAN_ANYC;
107 ic->ic_bss = ni;
108 ic->ic_txpower = IEEE80211_TXPOWER_MAX;
109 }
110
111 void
112 ieee80211_node_detach(struct ifnet *ifp)
113 {
114 struct ieee80211com *ic = (void *)ifp;
115
116 if (ic->ic_bss != NULL)
117 (*ic->ic_node_free)(ic, ic->ic_bss);
118 ieee80211_free_allnodes(ic);
119 IEEE80211_NODE_LOCK_DESTROY(ic);
120 }
121
122 /*
123 * AP scanning support.
124 */
125
126 /*
127 * Initialize the active channel set based on the set
128 * of available channels and the current PHY mode.
129 */
130 static void
131 ieee80211_reset_scan(struct ifnet *ifp)
132 {
133 struct ieee80211com *ic = (void *)ifp;
134
135 memcpy(ic->ic_chan_scan, ic->ic_chan_active,
136 sizeof(ic->ic_chan_active));
137 /* NB: hack, setup so next_scan starts with the first channel */
138 if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
139 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX];
140 }
141
142 /*
143 * Begin an active scan.
144 */
145 void
146 ieee80211_begin_scan(struct ifnet *ifp)
147 {
148 struct ieee80211com *ic = (void *)ifp;
149
150 /*
151 * In all but hostap mode scanning starts off in
152 * an active mode before switching to passive.
153 */
154 if (ic->ic_opmode != IEEE80211_M_HOSTAP) {
155 ic->ic_flags |= IEEE80211_F_ASCAN;
156 ic->ic_stats.is_scan_active++;
157 } else
158 ic->ic_stats.is_scan_passive++;
159 if (ifp->if_flags & IFF_DEBUG)
160 if_printf(ifp, "begin %s scan\n",
161 (ic->ic_flags & IEEE80211_F_ASCAN) ?
162 "active" : "passive");
163 /*
164 * Clear scan state and flush any previously seen
165 * AP's. Note that the latter assumes we don't act
166 * as both an AP and a station, otherwise we'll
167 * potentially flush state of stations associated
168 * with us.
169 */
170 ieee80211_reset_scan(ifp);
171 ieee80211_free_allnodes(ic);
172
173 /* Scan the next channel. */
174 ieee80211_next_scan(ifp);
175 }
176
177 /*
178 * Switch to the next channel marked for scanning.
179 */
180 void
181 ieee80211_next_scan(struct ifnet *ifp)
182 {
183 struct ieee80211com *ic = (void *)ifp;
184 struct ieee80211_channel *chan;
185
186 chan = ic->ic_bss->ni_chan;
187 for (;;) {
188 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
189 chan = &ic->ic_channels[0];
190 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
191 /*
192 * Honor channels marked passive-only
193 * during an active scan.
194 */
195 if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 ||
196 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0)
197 break;
198 }
199 if (chan == ic->ic_bss->ni_chan) {
200 ieee80211_end_scan(ifp);
201 return;
202 }
203 }
204 clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
205 IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n",
206 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
207 ieee80211_chan2ieee(ic, chan)));
208 ic->ic_bss->ni_chan = chan;
209 ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
210 }
211
212 void
213 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
214 {
215 struct ieee80211_node *ni;
216 struct ifnet *ifp = &ic->ic_if;
217
218 ni = ic->ic_bss;
219 if (ifp->if_flags & IFF_DEBUG)
220 if_printf(ifp, "creating ibss\n");
221 ic->ic_flags |= IEEE80211_F_SIBSS;
222 ni->ni_chan = chan;
223 ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
224 IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr);
225 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
226 if (ic->ic_opmode == IEEE80211_M_IBSS)
227 ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */
228 ni->ni_esslen = ic->ic_des_esslen;
229 memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
230 ni->ni_rssi = 0;
231 ni->ni_rstamp = 0;
232 memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp));
233 ni->ni_intval = ic->ic_lintval;
234 ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
235 if (ic->ic_flags & IEEE80211_F_WEPON)
236 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
237 if (ic->ic_phytype == IEEE80211_T_FH) {
238 ni->ni_fhdwell = 200; /* XXX */
239 ni->ni_fhindex = 1;
240 }
241 ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
242 }
243
244 static int
245 ieee80211_match_bss(struct ifnet *ifp, struct ieee80211_node *ni)
246 {
247 struct ieee80211com *ic = (void *)ifp;
248 u_int8_t rate;
249 int fail;
250
251 fail = 0;
252 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
253 fail |= 0x01;
254 if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
255 ni->ni_chan != ic->ic_des_chan)
256 fail |= 0x01;
257 if (ic->ic_opmode == IEEE80211_M_IBSS) {
258 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
259 fail |= 0x02;
260 } else {
261 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
262 fail |= 0x02;
263 }
264 if (ic->ic_flags & IEEE80211_F_WEPON) {
265 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
266 fail |= 0x04;
267 } else {
268 /* XXX does this mean privacy is supported or required? */
269 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
270 fail |= 0x04;
271 }
272 rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO);
273 if (rate & IEEE80211_RATE_BASIC)
274 fail |= 0x08;
275 if (ic->ic_des_esslen != 0 &&
276 (ni->ni_esslen != ic->ic_des_esslen ||
277 memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
278 fail |= 0x10;
279 if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
280 !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
281 fail |= 0x20;
282 #ifdef IEEE80211_DEBUG
283 if (ifp->if_flags & IFF_DEBUG) {
284 printf(" %c %s", fail ? '-' : '+',
285 ether_sprintf(ni->ni_macaddr));
286 printf(" %s%c", ether_sprintf(ni->ni_bssid),
287 fail & 0x20 ? '!' : ' ');
288 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
289 fail & 0x01 ? '!' : ' ');
290 printf(" %+4d", ni->ni_rssi);
291 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
292 fail & 0x08 ? '!' : ' ');
293 printf(" %4s%c",
294 (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
295 (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
296 "????",
297 fail & 0x02 ? '!' : ' ');
298 printf(" %3s%c ",
299 (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
300 "wep" : "no",
301 fail & 0x04 ? '!' : ' ');
302 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
303 printf("%s\n", fail & 0x10 ? "!" : "");
304 }
305 #endif
306 return fail;
307 }
308
309 /*
310 * Complete a scan of potential channels.
311 */
312 void
313 ieee80211_end_scan(struct ifnet *ifp)
314 {
315 struct ieee80211com *ic = (void *)ifp;
316 struct ieee80211_node *ni, *nextbs, *selbs;
317 int i, fail;
318
319 ic->ic_flags &= ~IEEE80211_F_ASCAN;
320 ni = TAILQ_FIRST(&ic->ic_node);
321
322 if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
323 /* XXX off stack? */
324 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)];
325 /*
326 * The passive scan to look for existing AP's completed,
327 * select a channel to camp on. Identify the channels
328 * that already have one or more AP's and try to locate
329 * an unnoccupied one. If that fails, pick a random
330 * channel from the active set.
331 */
332 for (; ni != NULL; ni = nextbs) {
333 ieee80211_ref_node(ni);
334 nextbs = TAILQ_NEXT(ni, ni_list);
335 setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan));
336 ieee80211_free_node(ic, ni);
337 }
338 for (i = 0; i < IEEE80211_CHAN_MAX; i++)
339 if (isset(ic->ic_chan_active, i) && isclr(occupied, i))
340 break;
341 if (i == IEEE80211_CHAN_MAX) {
342 fail = arc4random() & 3; /* random 0-3 */
343 for (i = 0; i < IEEE80211_CHAN_MAX; i++)
344 if (isset(ic->ic_chan_active, i) && fail-- == 0)
345 break;
346 }
347 ieee80211_create_ibss(ic, &ic->ic_channels[i]);
348 return;
349 }
350 if (ni == NULL) {
351 IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__));
352 notfound:
353 if (ic->ic_opmode == IEEE80211_M_IBSS &&
354 (ic->ic_flags & IEEE80211_F_IBSSON) &&
355 ic->ic_des_esslen != 0) {
356 ieee80211_create_ibss(ic, ic->ic_ibss_chan);
357 return;
358 }
359 /*
360 * Reset the list of channels to scan and start again.
361 */
362 ieee80211_reset_scan(ifp);
363 ieee80211_next_scan(ifp);
364 return;
365 }
366 selbs = NULL;
367 if (ifp->if_flags & IFF_DEBUG)
368 if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n");
369 for (; ni != NULL; ni = nextbs) {
370 ieee80211_ref_node(ni);
371 nextbs = TAILQ_NEXT(ni, ni_list);
372 if (ni->ni_fails) {
373 /*
374 * The configuration of the access points may change
375 * during my scan. So delete the entry for the AP
376 * and retry to associate if there is another beacon.
377 */
378 if (ni->ni_fails++ > 2)
379 ieee80211_free_node(ic, ni);
380 continue;
381 }
382 if (ieee80211_match_bss(ifp, ni) == 0) {
383 if (selbs == NULL)
384 selbs = ni;
385 else if (ni->ni_rssi > selbs->ni_rssi) {
386 ieee80211_unref_node(&selbs);
387 selbs = ni;
388 } else
389 ieee80211_unref_node(&ni);
390 } else {
391 ieee80211_unref_node(&ni);
392 }
393 }
394 if (selbs == NULL)
395 goto notfound;
396 (*ic->ic_node_copy)(ic, ic->ic_bss, selbs);
397 if (ic->ic_opmode == IEEE80211_M_IBSS) {
398 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE |
399 IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
400 if (ic->ic_bss->ni_rates.rs_nrates == 0) {
401 selbs->ni_fails++;
402 ieee80211_unref_node(&selbs);
403 goto notfound;
404 }
405 ieee80211_unref_node(&selbs);
406 /*
407 * Discard scan set; the nodes have a refcnt of zero
408 * and have not asked the driver to setup private
409 * node state. Let them be repopulated on demand either
410 * through transmission (ieee80211_find_txnode) or receipt
411 * of a probe response (to be added).
412 */
413 ieee80211_free_allnodes(ic);
414 ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
415 } else {
416 ieee80211_unref_node(&selbs);
417 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
418 }
419 }
420
421 static struct ieee80211_node *
422 ieee80211_node_alloc(struct ieee80211com *ic)
423 {
424 struct ieee80211_node *ni;
425 MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node),
426 M_80211_NODE, M_NOWAIT | M_ZERO);
427 return ni;
428 }
429
430 static void
431 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni)
432 {
433 FREE(ni, M_80211_NODE);
434 }
435
436 static void
437 ieee80211_node_copy(struct ieee80211com *ic,
438 struct ieee80211_node *dst, const struct ieee80211_node *src)
439 {
440 *dst = *src;
441 }
442
443 static u_int8_t
444 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni)
445 {
446 return ni->ni_rssi;
447 }
448
449 static void
450 ieee80211_setup_node(struct ieee80211com *ic,
451 struct ieee80211_node *ni, u_int8_t *macaddr)
452 {
453 int hash;
454
455 IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
456 hash = IEEE80211_NODE_HASH(macaddr);
457 ni->ni_refcnt = 1; /* mark referenced */
458 IEEE80211_NODE_LOCK(ic);
459 TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list);
460 LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash);
461 /*
462 * Note we don't enable the inactive timer when acting
463 * as a station. Nodes created in this mode represent
464 * AP's identified while scanning. If we time them out
465 * then several things happen: we can't return the data
466 * to users to show the list of AP's we encountered, and
467 * more importantly, we'll incorrectly deauthenticate
468 * ourself because the inactivity timer will kick us off.
469 */
470 if (ic->ic_opmode != IEEE80211_M_STA)
471 ic->ic_inact_timer = IEEE80211_INACT_WAIT;
472 IEEE80211_NODE_UNLOCK(ic);
473 }
474
475 struct ieee80211_node *
476 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr)
477 {
478 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic);
479 if (ni != NULL)
480 ieee80211_setup_node(ic, ni, macaddr);
481 else
482 ic->ic_stats.is_rx_nodealloc++;
483 return ni;
484 }
485
486 struct ieee80211_node *
487 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr)
488 {
489 struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic);
490 if (ni != NULL) {
491 ieee80211_setup_node(ic, ni, macaddr);
492 /*
493 * Inherit from ic_bss.
494 */
495 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
496 ni->ni_chan = ic->ic_bss->ni_chan;
497 } else
498 ic->ic_stats.is_rx_nodealloc++;
499 return ni;
500 }
501
502 static struct ieee80211_node *
503 _ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr)
504 {
505 struct ieee80211_node *ni;
506 int hash;
507
508 IEEE80211_NODE_LOCK_ASSERT(ic);
509
510 hash = IEEE80211_NODE_HASH(macaddr);
511 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
512 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
513 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */
514 return ni;
515 }
516 }
517 return NULL;
518 }
519
520 struct ieee80211_node *
521 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr)
522 {
523 struct ieee80211_node *ni;
524
525 IEEE80211_NODE_LOCK(ic);
526 ni = _ieee80211_find_node(ic, macaddr);
527 IEEE80211_NODE_UNLOCK(ic);
528 return ni;
529 }
530
531 /*
532 * Return a reference to the appropriate node for sending
533 * a data frame. This handles node discovery in adhoc networks.
534 */
535 struct ieee80211_node *
536 ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr)
537 {
538 struct ieee80211_node *ni;
539
540 /*
541 * The destination address should be in the node table
542 * unless we are operating in station mode or this is a
543 * multicast/broadcast frame.
544 */
545 if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
546 return ic->ic_bss;
547
548 /* XXX can't hold lock across dup_bss 'cuz of recursive locking */
549 IEEE80211_NODE_LOCK(ic);
550 ni = _ieee80211_find_node(ic, macaddr);
551 IEEE80211_NODE_UNLOCK(ic);
552 if (ni == NULL &&
553 (ic->ic_opmode == IEEE80211_M_IBSS ||
554 ic->ic_opmode == IEEE80211_M_AHDEMO)) {
555 /*
556 * Fake up a node; this handles node discovery in
557 * adhoc mode. Note that for the driver's benefit
558 * we we treat this like an association so the driver
559 * has an opportunity to setup it's private state.
560 *
561 * XXX need better way to handle this; issue probe
562 * request so we can deduce rate set, etc.
563 */
564 ni = ieee80211_dup_bss(ic, macaddr);
565 if (ni != NULL) {
566 /* XXX no rate negotiation; just dup */
567 ni->ni_rates = ic->ic_bss->ni_rates;
568 if (ic->ic_newassoc)
569 (*ic->ic_newassoc)(ic, ni, 1);
570 }
571 }
572 return ni;
573 }
574
575 /*
576 * Like find but search based on the channel too.
577 */
578 struct ieee80211_node *
579 ieee80211_lookup_node(struct ieee80211com *ic,
580 u_int8_t *macaddr, struct ieee80211_channel *chan)
581 {
582 struct ieee80211_node *ni;
583 int hash;
584
585 hash = IEEE80211_NODE_HASH(macaddr);
586 IEEE80211_NODE_LOCK(ic);
587 LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
588 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) &&
589 ni->ni_chan == chan) {
590 atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */
591 break;
592 }
593 }
594 IEEE80211_NODE_UNLOCK(ic);
595 return ni;
596 }
597
598 static void
599 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
600 {
601 KASSERT(ni != ic->ic_bss, ("freeing bss node"));
602
603 TAILQ_REMOVE(&ic->ic_node, ni, ni_list);
604 LIST_REMOVE(ni, ni_hash);
605 if (TAILQ_EMPTY(&ic->ic_node))
606 ic->ic_inact_timer = 0;
607 (*ic->ic_node_free)(ic, ni);
608 }
609
610 void
611 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
612 {
613 KASSERT(ni != ic->ic_bss, ("freeing ic_bss"));
614
615 /* XXX need equivalent of atomic_dec_and_test */
616 atomic_subtract_int(&ni->ni_refcnt, 1);
617 if (atomic_cmpset_int(&ni->ni_refcnt, 0, 1)) {
618 IEEE80211_NODE_LOCK(ic);
619 _ieee80211_free_node(ic, ni);
620 IEEE80211_NODE_UNLOCK(ic);
621 }
622 }
623
624 void
625 ieee80211_free_allnodes(struct ieee80211com *ic)
626 {
627 struct ieee80211_node *ni;
628
629 IEEE80211_NODE_LOCK(ic);
630 while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL)
631 _ieee80211_free_node(ic, ni);
632 IEEE80211_NODE_UNLOCK(ic);
633 }
634
635 /*
636 * Timeout inactive nodes. Note that we cannot hold the node
637 * lock while sending a frame as this would lead to a LOR.
638 * Instead we use a generation number to mark nodes that we've
639 * scanned and drop the lock and restart a scan if we have to
640 * time out a node. Since we are single-threaded by virtue of
641 * controlling the inactivity timer we can be sure this will
642 * process each node only once.
643 */
644 void
645 ieee80211_timeout_nodes(struct ieee80211com *ic)
646 {
647 struct ieee80211_node *ni;
648 u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/
649
650 restart:
651 IEEE80211_NODE_LOCK(ic);
652 TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
653 if (ni->ni_scangen == gen) /* previously handled */
654 continue;
655 ni->ni_scangen = gen;
656 if (++ni->ni_inact > IEEE80211_INACT_MAX) {
657 IEEE80211_DPRINTF(("station %s timed out "
658 "due to inactivity (%u secs)\n",
659 ether_sprintf(ni->ni_macaddr),
660 ni->ni_inact));
661 /*
662 * Send a deauthenticate frame.
663 *
664 * Drop the node lock before sending the
665 * deauthentication frame in case the driver takes
666 * a lock, as this will result in a LOR between the
667 * node lock and the driver lock.
668 */
669 IEEE80211_NODE_UNLOCK(ic);
670 IEEE80211_SEND_MGMT(ic, ni,
671 IEEE80211_FC0_SUBTYPE_DEAUTH,
672 IEEE80211_REASON_AUTH_EXPIRE);
673 ieee80211_free_node(ic, ni);
674 ic->ic_stats.is_node_timeout++;
675 goto restart;
676 }
677 }
678 if (!TAILQ_EMPTY(&ic->ic_node))
679 ic->ic_inact_timer = IEEE80211_INACT_WAIT;
680 IEEE80211_NODE_UNLOCK(ic);
681 }
682
683 void
684 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg)
685 {
686 struct ieee80211_node *ni;
687
688 IEEE80211_NODE_LOCK(ic);
689 TAILQ_FOREACH(ni, &ic->ic_node, ni_list)
690 (*f)(arg, ni);
691 IEEE80211_NODE_UNLOCK(ic);
692 }
Cache object: 66d3846b3b31e1dcc1c15a5662932e00
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