xref: /netbsd-src/sys/net80211/ieee80211_input.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: ieee80211_input.c,v 1.21 2004/02/11 10:19:32 mrg 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_input.c,v 1.12 2003/10/17 23:59:11 sam Exp $");
37 #else
38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_input.c,v 1.21 2004/02/11 10:19:32 mrg Exp $");
39 #endif
40 
41 #include "opt_inet.h"
42 
43 #ifdef __NetBSD__
44 #include "bpfilter.h"
45 #endif /* __NetBSD__ */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/malloc.h>
51 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/endian.h>
55 #include <sys/errno.h>
56 #ifdef __FreeBSD__
57 #include <sys/bus.h>
58 #endif
59 #include <sys/proc.h>
60 #include <sys/sysctl.h>
61 
62 #ifdef __FreeBSD__
63 #include <machine/atomic.h>
64 #endif
65 
66 #include <net/if.h>
67 #include <net/if_dl.h>
68 #include <net/if_media.h>
69 #include <net/if_arp.h>
70 #ifdef __FreeBSD__
71 #include <net/ethernet.h>
72 #else
73 #include <net/if_ether.h>
74 #endif
75 #include <net/if_llc.h>
76 
77 #include <net80211/ieee80211_var.h>
78 #include <net80211/ieee80211_compat.h>
79 
80 #if NBPFILTER > 0
81 #include <net/bpf.h>
82 #endif
83 
84 #ifdef INET
85 #include <netinet/in.h>
86 #ifdef __FreeBSD__
87 #include <netinet/if_ether.h>
88 #else
89 #include <net/if_ether.h>
90 #endif
91 #endif
92 
93 static void ieee80211_recv_pspoll(struct ieee80211com *,
94     struct mbuf *, int, u_int32_t);
95 
96 /*
97  * Process a received frame.  The node associated with the sender
98  * should be supplied.  If nothing was found in the node table then
99  * the caller is assumed to supply a reference to ic_bss instead.
100  * The RSSI and a timestamp are also supplied.  The RSSI data is used
101  * during AP scanning to select a AP to associate with; it can have
102  * any units so long as values have consistent units and higher values
103  * mean ``better signal''.  The receive timestamp is currently not used
104  * by the 802.11 layer.
105  */
106 void
107 ieee80211_input(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node *ni,
108 	int rssi, u_int32_t rstamp)
109 {
110 	struct ieee80211com *ic = (void *)ifp;
111 	struct ieee80211_frame *wh;
112 	struct ether_header *eh;
113 	struct mbuf *m1;
114 	int len;
115 	u_int8_t dir, type, subtype;
116 	u_int8_t *bssid;
117 	u_int16_t rxseq;
118 	ALTQ_DECL(struct altq_pktattr pktattr;)
119 
120 	IASSERT(ni != NULL, ("null node"));
121 
122 	/* trim CRC here so WEP can find its own CRC at the end of packet. */
123 	if (m->m_flags & M_HASFCS) {
124 		m_adj(m, -IEEE80211_CRC_LEN);
125 		m->m_flags &= ~M_HASFCS;
126 	}
127 
128 	/*
129 	 * In monitor mode, send everything directly to bpf.
130 	 * Also do not process frames w/o i_addr2 any further.
131 	 * XXX may want to include the CRC
132 	 */
133 	if (ic->ic_opmode == IEEE80211_M_MONITOR ||
134 	    m->m_pkthdr.len < sizeof(struct ieee80211_frame_min))
135 		goto out;
136 
137 	wh = mtod(m, struct ieee80211_frame *);
138 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
139 	    IEEE80211_FC0_VERSION_0) {
140 		if (ifp->if_flags & IFF_DEBUG)
141 			if_printf(ifp, "receive packet with wrong version: %x\n",
142 			    wh->i_fc[0]);
143 		ieee80211_unref_node(&ni);
144 		ic->ic_stats.is_rx_badversion++;
145 		goto err;
146 	}
147 
148 	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
149 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
150 	/*
151 	 * NB: We are not yet prepared to handle control frames,
152 	 *     but permitting drivers to send them to us allows
153 	 *     them to go through bpf tapping at the 802.11 layer.
154 	 */
155 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
156 		/* XXX statistic */
157 		IEEE80211_DPRINTF2(("%s: frame too short, len %u\n",
158 			__func__, m->m_pkthdr.len));
159 		ic->ic_stats.is_rx_tooshort++;
160 		goto out;		/* XXX */
161 	}
162 	if (ic->ic_state != IEEE80211_S_SCAN) {
163 		switch (ic->ic_opmode) {
164 		case IEEE80211_M_STA:
165 			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_bssid)) {
166 				/* not interested in */
167 				IEEE80211_DPRINTF2(("%s: discard frame from "
168 					"bss %s\n", __func__,
169 					ether_sprintf(wh->i_addr2)));
170 				ic->ic_stats.is_rx_wrongbss++;
171 				goto out;
172 			}
173 			break;
174 		case IEEE80211_M_IBSS:
175 		case IEEE80211_M_AHDEMO:
176 		case IEEE80211_M_HOSTAP:
177 			if (dir == IEEE80211_FC1_DIR_NODS)
178 				bssid = wh->i_addr3;
179 			else
180 				bssid = wh->i_addr1;
181 			if (!IEEE80211_ADDR_EQ(bssid, ic->ic_bss->ni_bssid) &&
182 			    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr) &&
183 			    (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) ==
184 			    IEEE80211_FC0_TYPE_DATA) {
185 				/* not interested in */
186 				IEEE80211_DPRINTF2(("%s: discard frame from "
187 					"bss %s\n", __func__,
188 					ether_sprintf(bssid)));
189 				ic->ic_stats.is_rx_wrongbss++;
190 				goto out;
191 			}
192 			break;
193 		case IEEE80211_M_MONITOR:
194 			goto out;
195 		default:
196 			/* XXX catch bad values */
197 			break;
198 		}
199 		ni->ni_rssi = rssi;
200 		ni->ni_rstamp = rstamp;
201 		rxseq = ni->ni_rxseq;
202 		ni->ni_rxseq =
203 		    le16toh(*(u_int16_t *)wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
204 		/* TODO: fragment */
205 		if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
206 		    rxseq == ni->ni_rxseq) {
207 			/* duplicate, silently discarded */
208 			ic->ic_stats.is_rx_dup++; /* XXX per-station stat */
209 			goto out;
210 		}
211 		ni->ni_inact = 0;
212 	}
213 
214 	if (ic->ic_set_tim != NULL &&
215 	    (wh->i_fc[1] & IEEE80211_FC1_PWR_MGT)
216 	    && ni->ni_pwrsave == 0) {
217 		/* turn on power save mode */
218 
219 		if (ifp->if_flags & IFF_DEBUG)
220 			printf("%s: power save mode on for %s\n",
221 			    ifp->if_xname, ether_sprintf(wh->i_addr2));
222 
223 		ni->ni_pwrsave = IEEE80211_PS_SLEEP;
224 	}
225 	if (ic->ic_set_tim != NULL &&
226 	    (wh->i_fc[1] & IEEE80211_FC1_PWR_MGT) == 0 &&
227 	    ni->ni_pwrsave != 0) {
228 		/* turn off power save mode, dequeue stored packets */
229 
230 		ni->ni_pwrsave = 0;
231 		if (ic->ic_set_tim)
232 			ic->ic_set_tim(ic, ni->ni_associd, 0);
233 
234 		if (ifp->if_flags & IFF_DEBUG)
235 			printf("%s: power save mode off for %s\n",
236 			    ifp->if_xname, ether_sprintf(wh->i_addr2));
237 
238 		while (!IF_IS_EMPTY(&ni->ni_savedq)) {
239 			struct mbuf *m;
240 			IF_DEQUEUE(&ni->ni_savedq, m);
241 			IF_ENQUEUE(&ic->ic_pwrsaveq, m);
242 			(*ifp->if_start)(ifp);
243 		}
244 	}
245 
246 	switch (type) {
247 	case IEEE80211_FC0_TYPE_DATA:
248 		switch (ic->ic_opmode) {
249 		case IEEE80211_M_STA:
250 			if (dir != IEEE80211_FC1_DIR_FROMDS) {
251 				ic->ic_stats.is_rx_wrongdir++;
252 				goto out;
253 			}
254 			if ((ifp->if_flags & IFF_SIMPLEX) &&
255 			    IEEE80211_IS_MULTICAST(wh->i_addr1) &&
256 			    IEEE80211_ADDR_EQ(wh->i_addr3, ic->ic_myaddr)) {
257 				/*
258 				 * In IEEE802.11 network, multicast packet
259 				 * sent from me is broadcasted from AP.
260 				 * It should be silently discarded for
261 				 * SIMPLEX interface.
262 				 */
263 				ic->ic_stats.is_rx_mcastecho++;
264 				goto out;
265 			}
266 			break;
267 		case IEEE80211_M_IBSS:
268 		case IEEE80211_M_AHDEMO:
269 			if (dir != IEEE80211_FC1_DIR_NODS) {
270 				ic->ic_stats.is_rx_wrongdir++;
271 				goto out;
272 			}
273 			break;
274 		case IEEE80211_M_HOSTAP:
275 			if (dir != IEEE80211_FC1_DIR_TODS) {
276 				ic->ic_stats.is_rx_wrongdir++;
277 				goto out;
278 			}
279 			/* check if source STA is associated */
280 			if (ni == ic->ic_bss) {
281 				IEEE80211_DPRINTF(("%s: data from unknown src "
282 					"%s\n", __func__,
283 					ether_sprintf(wh->i_addr2)));
284 				/* NB: caller deals with reference */
285 				ni = ieee80211_dup_bss(ic, wh->i_addr2);
286 				if (ni != NULL) {
287 					IEEE80211_SEND_MGMT(ic, ni,
288 					    IEEE80211_FC0_SUBTYPE_DEAUTH,
289 					    IEEE80211_REASON_NOT_AUTHED);
290 					ieee80211_free_node(ic, ni);
291 				}
292 				ic->ic_stats.is_rx_notassoc++;
293 				goto err;
294 			}
295 			if (ni->ni_associd == 0) {
296 				IEEE80211_DPRINTF(("ieee80211_input: "
297 				    "data from unassoc src %s\n",
298 				    ether_sprintf(wh->i_addr2)));
299 				IEEE80211_SEND_MGMT(ic, ni,
300 				    IEEE80211_FC0_SUBTYPE_DISASSOC,
301 				    IEEE80211_REASON_NOT_ASSOCED);
302 				ieee80211_unref_node(&ni);
303 				ic->ic_stats.is_rx_notassoc++;
304 				goto err;
305 			}
306 			break;
307 		case IEEE80211_M_MONITOR:
308 			break;
309 		}
310 		if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
311 			if (ic->ic_flags & IEEE80211_F_WEPON) {
312 				m = ieee80211_wep_crypt(ifp, m, 0);
313 				if (m == NULL) {
314 					ic->ic_stats.is_rx_wepfail++;
315 					goto err;
316 				}
317 				wh = mtod(m, struct ieee80211_frame *);
318 			} else {
319 				ic->ic_stats.is_rx_nowep++;
320 				goto out;
321 			}
322 		}
323 #if NBPFILTER > 0
324 		/* copy to listener after decrypt */
325 		if (ic->ic_rawbpf)
326 			bpf_mtap(ic->ic_rawbpf, m);
327 #endif
328 		m = ieee80211_decap(ifp, m);
329 		if (m == NULL) {
330 			IEEE80211_DPRINTF(("ieee80211_input: "
331 			    "decapsulation error for src %s\n",
332 			    ether_sprintf(wh->i_addr2)));
333 			ic->ic_stats.is_rx_decap++;
334 			goto err;
335 		}
336 		ifp->if_ipackets++;
337 
338 		/* perform as a bridge within the AP */
339 		m1 = NULL;
340 		if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
341 			eh = mtod(m, struct ether_header *);
342 			if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
343 				m1 = m_copypacket(m, M_DONTWAIT);
344 				if (m1 == NULL)
345 					ifp->if_oerrors++;
346 				else
347 					m1->m_flags |= M_MCAST;
348 			} else {
349 				ni = ieee80211_find_node(ic, eh->ether_dhost);
350 				if (ni != NULL) {
351 					if (ni->ni_associd != 0) {
352 						m1 = m;
353 						m = NULL;
354 					}
355 					ieee80211_unref_node(&ni);
356 				}
357 			}
358 			if (m1 != NULL) {
359 #ifdef ALTQ
360 				if (ALTQ_IS_ENABLED(&ifp->if_snd))
361 					altq_etherclassify(&ifp->if_snd, m1,
362 					    &pktattr);
363 #endif
364 				len = m1->m_pkthdr.len;
365 				IF_ENQUEUE(&ifp->if_snd, m1);
366 				if (m != NULL)
367 					ifp->if_omcasts++;
368 				ifp->if_obytes += len;
369 			}
370 		}
371 		if (m != NULL) {
372 #if NBPFILTER > 0
373 			/*
374 			 * If we forward packet into transmitter of the AP,
375 			 * we don't need to duplicate for DLT_EN10MB.
376 			 */
377 			if (ifp->if_bpf && m1 == NULL)
378 				bpf_mtap(ifp->if_bpf, m);
379 #endif
380 			(*ifp->if_input)(ifp, m);
381 		}
382 		return;
383 
384 	case IEEE80211_FC0_TYPE_MGT:
385 		if (dir != IEEE80211_FC1_DIR_NODS) {
386 			ic->ic_stats.is_rx_wrongdir++;
387 			goto err;
388 		}
389 		if (ic->ic_opmode == IEEE80211_M_AHDEMO) {
390 			ic->ic_stats.is_rx_ahdemo_mgt++;
391 			goto out;
392 		}
393 		subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
394 
395 		/* drop frames without interest */
396 		if (ic->ic_state == IEEE80211_S_SCAN) {
397 			if (subtype != IEEE80211_FC0_SUBTYPE_BEACON &&
398 			    subtype != IEEE80211_FC0_SUBTYPE_PROBE_RESP) {
399 				ic->ic_stats.is_rx_mgtdiscard++;
400 				goto out;
401 			}
402 		} else {
403 			if (ic->ic_opmode != IEEE80211_M_IBSS &&
404 			    subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
405 				ic->ic_stats.is_rx_mgtdiscard++;
406 				goto out;
407 			}
408 		}
409 
410 		if (ifp->if_flags & IFF_DEBUG) {
411 			/* avoid to print too many frames */
412 			int doprint = 0;
413 
414 			switch (subtype) {
415 			case IEEE80211_FC0_SUBTYPE_BEACON:
416 				if (ic->ic_state == IEEE80211_S_SCAN)
417 					doprint = 1;
418 				break;
419 			case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
420 				if (ic->ic_opmode == IEEE80211_M_IBSS)
421 					doprint = 1;
422 				break;
423 			default:
424 				doprint = 1;
425 				break;
426 			}
427 #ifdef IEEE80211_DEBUG
428 			doprint += ieee80211_debug;
429 #endif
430 			if (doprint)
431 				if_printf(ifp, "received %s from %s rssi %d\n",
432 				    ieee80211_mgt_subtype_name[subtype
433 				    >> IEEE80211_FC0_SUBTYPE_SHIFT],
434 				    ether_sprintf(wh->i_addr2), rssi);
435 		}
436 #if NBPFILTER > 0
437 		if (ic->ic_rawbpf)
438 			bpf_mtap(ic->ic_rawbpf, m);
439 #endif
440 		(*ic->ic_recv_mgmt)(ic, m, ni, subtype, rssi, rstamp);
441 		m_freem(m);
442 		return;
443 
444 	case IEEE80211_FC0_TYPE_CTL:
445 		ic->ic_stats.is_rx_ctl++;
446 		if (ic->ic_opmode != IEEE80211_M_HOSTAP)
447 			goto out;
448 		subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
449 		if (subtype == IEEE80211_FC0_SUBTYPE_PS_POLL) {
450 			/* XXX statistic */
451 			/* Dump out a single packet from the host */
452 			if (ifp->if_flags & IFF_DEBUG)
453 				printf("%s: got power save probe from %s\n",
454 				    ifp->if_xname,
455 				    ether_sprintf(wh->i_addr2));
456 			ieee80211_recv_pspoll(ic, m, rssi, rstamp);
457 		}
458 		goto out;
459 
460 	default:
461 		IEEE80211_DPRINTF(("%s: bad type %x\n", __func__, type));
462 		/* should not come here */
463 		break;
464 	}
465   err:
466 	ifp->if_ierrors++;
467   out:
468 	if (m != NULL) {
469 #if NBPFILTER > 0
470 		if (ic->ic_rawbpf)
471 			bpf_mtap(ic->ic_rawbpf, m);
472 #endif
473 		m_freem(m);
474 	}
475 }
476 
477 struct mbuf *
478 ieee80211_decap(struct ifnet *ifp, struct mbuf *m)
479 {
480 	struct ether_header *eh;
481 	struct ieee80211_frame wh;
482 	struct llc *llc;
483 
484 	if (m->m_len < sizeof(wh) + sizeof(*llc)) {
485 		m = m_pullup(m, sizeof(wh) + sizeof(*llc));
486 		if (m == NULL)
487 			return NULL;
488 	}
489 	memcpy(&wh, mtod(m, caddr_t), sizeof(wh));
490 	llc = (struct llc *)(mtod(m, caddr_t) + sizeof(wh));
491 	if (llc->llc_dsap == LLC_SNAP_LSAP && llc->llc_ssap == LLC_SNAP_LSAP &&
492 	    llc->llc_control == LLC_UI && llc->llc_snap.org_code[0] == 0 &&
493 	    llc->llc_snap.org_code[1] == 0 && llc->llc_snap.org_code[2] == 0) {
494 		m_adj(m, sizeof(wh) + sizeof(struct llc) - sizeof(*eh));
495 		llc = NULL;
496 	} else {
497 		m_adj(m, sizeof(wh) - sizeof(*eh));
498 	}
499 	eh = mtod(m, struct ether_header *);
500 	switch (wh.i_fc[1] & IEEE80211_FC1_DIR_MASK) {
501 	case IEEE80211_FC1_DIR_NODS:
502 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
503 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
504 		break;
505 	case IEEE80211_FC1_DIR_TODS:
506 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
507 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
508 		break;
509 	case IEEE80211_FC1_DIR_FROMDS:
510 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
511 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr3);
512 		break;
513 	case IEEE80211_FC1_DIR_DSTODS:
514 		/* not yet supported */
515 		IEEE80211_DPRINTF(("%s: DS to DS\n", __func__));
516 		m_freem(m);
517 		return NULL;
518 	}
519 #ifdef ALIGNED_POINTER
520 	if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), u_int32_t)) {
521 		struct mbuf *n, *n0, **np;
522 		caddr_t newdata;
523 		int off, pktlen;
524 
525 		n0 = NULL;
526 		np = &n0;
527 		off = 0;
528 		pktlen = m->m_pkthdr.len;
529 		while (pktlen > off) {
530 			if (n0 == NULL) {
531 				MGETHDR(n, M_DONTWAIT, MT_DATA);
532 				if (n == NULL) {
533 					m_freem(m);
534 					return NULL;
535 				}
536 #ifdef __FreeBSD__
537 				M_MOVE_PKTHDR(n, m);
538 #else
539 				M_COPY_PKTHDR(n, m);
540 #endif
541 				n->m_len = MHLEN;
542 			} else {
543 				MGET(n, M_DONTWAIT, MT_DATA);
544 				if (n == NULL) {
545 					m_freem(m);
546 					m_freem(n0);
547 					return NULL;
548 				}
549 				n->m_len = MLEN;
550 			}
551 			if (pktlen - off >= MINCLSIZE) {
552 				MCLGET(n, M_DONTWAIT);
553 				if (n->m_flags & M_EXT)
554 					n->m_len = n->m_ext.ext_size;
555 			}
556 			if (n0 == NULL) {
557 				newdata =
558 				    (caddr_t)ALIGN(n->m_data + sizeof(*eh)) -
559 				    sizeof(*eh);
560 				n->m_len -= newdata - n->m_data;
561 				n->m_data = newdata;
562 			}
563 			if (n->m_len > pktlen - off)
564 				n->m_len = pktlen - off;
565 			m_copydata(m, off, n->m_len, mtod(n, caddr_t));
566 			off += n->m_len;
567 			*np = n;
568 			np = &n->m_next;
569 		}
570 		m_freem(m);
571 		m = n0;
572 	}
573 #endif /* ALIGNED_POINTER */
574 	if (llc != NULL) {
575 		eh = mtod(m, struct ether_header *);
576 		eh->ether_type = htons(m->m_pkthdr.len - sizeof(*eh));
577 	}
578 	return m;
579 }
580 
581 /*
582  * Install received rate set information in the node's state block.
583  */
584 static int
585 ieee80211_setup_rates(struct ieee80211com *ic, struct ieee80211_node *ni,
586 	u_int8_t *rates, u_int8_t *xrates, int flags)
587 {
588 	struct ieee80211_rateset *rs = &ni->ni_rates;
589 
590 	memset(rs, 0, sizeof(*rs));
591 	rs->rs_nrates = rates[1];
592 	memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
593 	if (xrates != NULL) {
594 		u_int8_t nxrates;
595 		/*
596 		 * Tack on 11g extended supported rate element.
597 		 */
598 		nxrates = xrates[1];
599 		if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
600 			nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
601 			IEEE80211_DPRINTF(("%s: extended rate set too large;"
602 				" only using %u of %u rates\n",
603 				__func__, nxrates, xrates[1]));
604 			ic->ic_stats.is_rx_rstoobig++;
605 		}
606 		memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
607 		rs->rs_nrates += nxrates;
608 	}
609 	return ieee80211_fix_rate(ic, ni, flags);
610 }
611 
612 /* Verify the existence and length of __elem or get out. */
613 #define IEEE80211_VERIFY_ELEMENT(__elem, __maxlen) do {			\
614 	if ((__elem) == NULL) {						\
615 		IEEE80211_DPRINTF(("%s: no " #__elem "in %s frame\n",	\
616 			__func__, ieee80211_mgt_subtype_name[subtype >>	\
617 				IEEE80211_FC0_SUBTYPE_SHIFT]));		\
618 		ic->ic_stats.is_rx_elem_missing++;			\
619 		return;							\
620 	}								\
621 	if ((__elem)[1] > (__maxlen)) {					\
622 		IEEE80211_DPRINTF(("%s: bad " #__elem " len %d in %s "	\
623 			"frame from %s\n", __func__, (__elem)[1],	\
624 			ieee80211_mgt_subtype_name[subtype >>		\
625 				IEEE80211_FC0_SUBTYPE_SHIFT],		\
626 			ether_sprintf(wh->i_addr2)));			\
627 		ic->ic_stats.is_rx_elem_toobig++;			\
628 		return;							\
629 	}								\
630 } while (0)
631 
632 #define	IEEE80211_VERIFY_LENGTH(_len, _minlen) do {			\
633 	if ((_len) < (_minlen)) {					\
634 		IEEE80211_DPRINTF(("%s: %s frame too short from %s\n",	\
635 			__func__,					\
636 			ieee80211_mgt_subtype_name[subtype >>		\
637 				IEEE80211_FC0_SUBTYPE_SHIFT],		\
638 			ether_sprintf(wh->i_addr2)));			\
639 		ic->ic_stats.is_rx_elem_toosmall++;			\
640 		return;							\
641 	}								\
642 } while (0)
643 
644 static void
645 ieee80211_auth_open(struct ieee80211com *ic, struct ieee80211_frame *wh,
646     struct ieee80211_node *ni, int rssi, u_int32_t rstamp, u_int16_t seq,
647     u_int16_t status)
648 {
649 	struct ifnet *ifp = &ic->ic_if;
650 	int allocbs;
651 	switch (ic->ic_opmode) {
652 	case IEEE80211_M_IBSS:
653 		if (ic->ic_state != IEEE80211_S_RUN ||
654 		    seq != IEEE80211_AUTH_OPEN_REQUEST) {
655 			ic->ic_stats.is_rx_bad_auth++;
656 			return;
657 		}
658 		ieee80211_new_state(ic, IEEE80211_S_AUTH,
659 		    wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
660 		break;
661 
662 	case IEEE80211_M_AHDEMO:
663 		/* should not come here */
664 		break;
665 
666 	case IEEE80211_M_HOSTAP:
667 		if (ic->ic_state != IEEE80211_S_RUN ||
668 		    seq != IEEE80211_AUTH_OPEN_REQUEST) {
669 			ic->ic_stats.is_rx_bad_auth++;
670 			return;
671 		}
672 		if (ni == ic->ic_bss) {
673 			ni = ieee80211_alloc_node(ic, wh->i_addr2);
674 			if (ni == NULL) {
675 				ic->ic_stats.is_rx_nodealloc++;
676 				return;
677 			}
678 			IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
679 			ni->ni_rssi = rssi;
680 			ni->ni_rstamp = rstamp;
681 			ni->ni_chan = ic->ic_bss->ni_chan;
682 			allocbs = 1;
683 		} else
684 			allocbs = 0;
685 		IEEE80211_SEND_MGMT(ic, ni,
686 			IEEE80211_FC0_SUBTYPE_AUTH, seq + 1);
687 		if (ifp->if_flags & IFF_DEBUG)
688 			if_printf(ifp, "station %s %s authenticated (open)\n",
689 			    ether_sprintf(ni->ni_macaddr),
690 			    (allocbs ? "newly" : "already"));
691 		break;
692 
693 	case IEEE80211_M_STA:
694 		if (ic->ic_state != IEEE80211_S_AUTH ||
695 		    seq != IEEE80211_AUTH_OPEN_RESPONSE) {
696 			ic->ic_stats.is_rx_bad_auth++;
697 			return;
698 		}
699 		if (status != 0) {
700 			if_printf(&ic->ic_if,
701 			    "open authentication failed (reason %d) for %s\n",
702 			    status,
703 			    ether_sprintf(wh->i_addr3));
704 			if (ni != ic->ic_bss)
705 				ni->ni_fails++;
706 			ic->ic_stats.is_rx_auth_fail++;
707 			return;
708 		}
709 		ieee80211_new_state(ic, IEEE80211_S_ASSOC,
710 		    wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
711 		break;
712 	case IEEE80211_M_MONITOR:
713 		break;
714 	}
715 }
716 
717 /* TBD send appropriate responses on error? */
718 static void
719 ieee80211_auth_shared(struct ieee80211com *ic, struct ieee80211_frame *wh,
720     u_int8_t *frm, u_int8_t *efrm, struct ieee80211_node *ni, int rssi,
721     u_int32_t rstamp, u_int16_t seq, u_int16_t status)
722 {
723 	struct ifnet *ifp = &ic->ic_if;
724 	u_int8_t *challenge = NULL;
725 	int allocbs, i;
726 
727 	if ((ic->ic_flags & IEEE80211_F_WEPON) == 0) {
728 		IEEE80211_DPRINTF(("%s: WEP is off\n", __func__));
729 		return;
730 	}
731 
732 	if (frm + 1 < efrm) {
733 		if (frm[1] + 2 > efrm - frm) {
734 			IEEE80211_DPRINTF(("elt %d %d bytes too long\n",
735 			    frm[0], (frm[1] + 2) - (int)(efrm - frm)));
736 			ic->ic_stats.is_rx_bad_auth++;
737 			return;
738 		}
739 		if (*frm == IEEE80211_ELEMID_CHALLENGE)
740 			challenge = frm;
741 		frm += frm[1] + 2;
742 	}
743 	switch (seq) {
744 	case IEEE80211_AUTH_SHARED_CHALLENGE:
745 	case IEEE80211_AUTH_SHARED_RESPONSE:
746 		if (challenge == NULL) {
747 			IEEE80211_DPRINTF(("%s: no challenge sent\n",
748 			    __func__));
749 			ic->ic_stats.is_rx_bad_auth++;
750 			return;
751 		}
752 		if (challenge[1] != IEEE80211_CHALLENGE_LEN) {
753 			IEEE80211_DPRINTF(("%s: bad challenge len %d\n",
754 			    __func__, challenge[1]));
755 			ic->ic_stats.is_rx_bad_auth++;
756 			return;
757 		}
758 	default:
759 		break;
760 	}
761 	switch (ic->ic_opmode) {
762 	case IEEE80211_M_MONITOR:
763 	case IEEE80211_M_AHDEMO:
764 	case IEEE80211_M_IBSS:
765 		IEEE80211_DPRINTF(("%s: unexpected operating mode\n",
766 		    __func__));
767 		return;
768 	case IEEE80211_M_HOSTAP:
769 		if (ic->ic_state != IEEE80211_S_RUN) {
770 			IEEE80211_DPRINTF(("%s: not running\n", __func__));
771 			return;
772 		}
773 		switch (seq) {
774 		case IEEE80211_AUTH_SHARED_REQUEST:
775 			if (ni == ic->ic_bss) {
776 				ni = ieee80211_alloc_node(ic, wh->i_addr2);
777 				if (ni == NULL) {
778 					ic->ic_stats.is_rx_nodealloc++;
779 					return;
780 				}
781 				IEEE80211_ADDR_COPY(ni->ni_bssid,
782 				    ic->ic_bss->ni_bssid);
783 				ni->ni_rssi = rssi;
784 				ni->ni_rstamp = rstamp;
785 				ni->ni_chan = ic->ic_bss->ni_chan;
786 				allocbs = 1;
787 			} else
788 				allocbs = 0;
789 			if (ni->ni_challenge == NULL)
790 				ni->ni_challenge = (u_int32_t*)malloc(
791 				    IEEE80211_CHALLENGE_LEN, M_DEVBUF,
792 				    M_NOWAIT);
793 			if (ni->ni_challenge == NULL) {
794 				IEEE80211_DPRINTF(("challenge alloc failed\n"));
795 				/* XXX statistic */
796 				return;
797 			}
798 			for (i = IEEE80211_CHALLENGE_LEN / sizeof(u_int32_t);
799 			     --i >= 0; )
800 				ni->ni_challenge[i] = arc4random();
801 			if (ifp->if_flags & IFF_DEBUG)
802 				if_printf(ifp, "station %s shared key "
803 					"%sauthentication\n",
804 					ether_sprintf(ni->ni_macaddr),
805 					allocbs ? "" : "re");
806 			break;
807 		case IEEE80211_AUTH_SHARED_RESPONSE:
808 			if (ni == ic->ic_bss) {
809 				IEEE80211_DPRINTF(("%s: unknown STA\n",
810 				    __func__));
811 				return;
812 			}
813 			if (ni->ni_challenge == NULL) {
814 				IEEE80211_DPRINTF((
815 				    "%s: no challenge recorded\n", __func__));
816 				ic->ic_stats.is_rx_bad_auth++;
817 				return;
818 			}
819 			if (memcmp(ni->ni_challenge, &challenge[2],
820 			           challenge[1]) != 0) {
821 				IEEE80211_DPRINTF(("%s: challenge mismatch\n",
822 				    __func__));
823 				ic->ic_stats.is_rx_auth_fail++;
824 				return;
825 			}
826 			if (ifp->if_flags & IFF_DEBUG)
827 				if_printf(ifp, "station %s authenticated "
828 					"(shared key)\n",
829 					ether_sprintf(ni->ni_macaddr));
830 			break;
831 		default:
832 			IEEE80211_DPRINTF(("%s: bad seq %d from %s\n",
833 			    __func__, seq, ether_sprintf(wh->i_addr2)));
834 			ic->ic_stats.is_rx_bad_auth++;
835 			return;
836 		}
837 		IEEE80211_SEND_MGMT(ic, ni,
838 			IEEE80211_FC0_SUBTYPE_AUTH, seq + 1);
839 		break;
840 
841 	case IEEE80211_M_STA:
842 		if (ic->ic_state != IEEE80211_S_AUTH)
843 			return;
844 		switch (seq) {
845 		case IEEE80211_AUTH_SHARED_PASS:
846 			if (ni->ni_challenge != NULL) {
847 				FREE(ni->ni_challenge, M_DEVBUF);
848 				ni->ni_challenge = NULL;
849 			}
850 			if (status != 0) {
851 				if_printf(&ic->ic_if,
852 				    "%s: shared authentication failed "
853 				    "(reason %d) for %s\n",
854 				    __func__, status,
855 				    ether_sprintf(wh->i_addr3));
856 				if (ni != ic->ic_bss)
857 					ni->ni_fails++;
858 				ic->ic_stats.is_rx_auth_fail++;
859 				return;
860 			}
861 			ieee80211_new_state(ic, IEEE80211_S_ASSOC,
862 			    wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
863 			break;
864 		case IEEE80211_AUTH_SHARED_CHALLENGE:
865 			if (ni->ni_challenge == NULL)
866 				ni->ni_challenge = (u_int32_t*)malloc(
867 				    challenge[1], M_DEVBUF, M_NOWAIT);
868 			if (ni->ni_challenge == NULL) {
869 				IEEE80211_DPRINTF((
870 				    "%s: challenge alloc failed\n", __func__));
871 				/* XXX statistic */
872 				return;
873 			}
874 			memcpy(ni->ni_challenge, &challenge[2], challenge[1]);
875 			IEEE80211_SEND_MGMT(ic, ni,
876 				IEEE80211_FC0_SUBTYPE_AUTH, seq + 1);
877 			break;
878 		default:
879 			IEEE80211_DPRINTF(("%s: bad seq %d from %s\n",
880 			    __func__, seq, ether_sprintf(wh->i_addr2)));
881 			ic->ic_stats.is_rx_bad_auth++;
882 			return;
883 		}
884 		break;
885 	}
886 }
887 
888 void
889 ieee80211_recv_mgmt(struct ieee80211com *ic, struct mbuf *m0,
890 	struct ieee80211_node *ni,
891 	int subtype, int rssi, u_int32_t rstamp)
892 {
893 #define	ISPROBE(_st)	((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
894 	struct ifnet *ifp = &ic->ic_if;
895 	struct ieee80211_frame *wh;
896 	u_int8_t *frm, *efrm;
897 	u_int8_t *ssid, *rates, *xrates;
898 	int reassoc, resp, newassoc, allocbs;
899 
900 	wh = mtod(m0, struct ieee80211_frame *);
901 	frm = (u_int8_t *)&wh[1];
902 	efrm = mtod(m0, u_int8_t *) + m0->m_len;
903 	switch (subtype) {
904 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
905 	case IEEE80211_FC0_SUBTYPE_BEACON: {
906 		u_int8_t *tstamp, *bintval, *capinfo, *country;
907 		u_int8_t chan, bchan, fhindex, erp;
908 		u_int16_t fhdwell;
909 
910 		if (ic->ic_opmode != IEEE80211_M_IBSS &&
911 		    ic->ic_state != IEEE80211_S_SCAN) {
912 			/* XXX: may be useful for background scan */
913 			return;
914 		}
915 
916 		/*
917 		 * beacon/probe response frame format
918 		 *	[8] time stamp
919 		 *	[2] beacon interval
920 		 *	[2] capability information
921 		 *	[tlv] ssid
922 		 *	[tlv] supported rates
923 		 *	[tlv] country information
924 		 *	[tlv] parameter set (FH/DS)
925 		 *	[tlv] erp information
926 		 *	[tlv] extended supported rates
927 		 */
928 		IEEE80211_VERIFY_LENGTH(efrm - frm, 12);
929 		tstamp  = frm;	frm += 8;
930 		bintval = frm;	frm += 2;
931 		capinfo = frm;	frm += 2;
932 		ssid = rates = xrates = country = NULL;
933 		bchan = ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan);
934 		chan = bchan;
935 		fhdwell = 0;
936 		fhindex = 0;
937 		erp = 0;
938 		while (frm < efrm) {
939 			switch (*frm) {
940 			case IEEE80211_ELEMID_SSID:
941 				ssid = frm;
942 				break;
943 			case IEEE80211_ELEMID_RATES:
944 				rates = frm;
945 				break;
946 			case IEEE80211_ELEMID_COUNTRY:
947 				country = frm;
948 				break;
949 			case IEEE80211_ELEMID_FHPARMS:
950 				if (ic->ic_phytype == IEEE80211_T_FH) {
951 					fhdwell = (frm[3] << 8) | frm[2];
952 					chan = IEEE80211_FH_CHAN(frm[4], frm[5]);
953 					fhindex = frm[6];
954 				}
955 				break;
956 			case IEEE80211_ELEMID_DSPARMS:
957 				/*
958 				 * XXX hack this since depending on phytype
959 				 * is problematic for multi-mode devices.
960 				 */
961 				if (ic->ic_phytype != IEEE80211_T_FH)
962 					chan = frm[2];
963 				break;
964 			case IEEE80211_ELEMID_TIM:
965 				break;
966 			case IEEE80211_ELEMID_XRATES:
967 				xrates = frm;
968 				break;
969 			case IEEE80211_ELEMID_ERP:
970 				if (frm[1] != 1) {
971 					IEEE80211_DPRINTF(("%s: invalid ERP "
972 						"element; length %u, expecting "
973 						"1\n", __func__, frm[1]));
974 					ic->ic_stats.is_rx_elem_toobig++;
975 					break;
976 				}
977 				erp = frm[2];
978 				break;
979 			default:
980 				IEEE80211_DPRINTF2(("%s: element id %u/len %u "
981 					"ignored\n", __func__, *frm, frm[1]));
982 				ic->ic_stats.is_rx_elem_unknown++;
983 				break;
984 			}
985 			frm += frm[1] + 2;
986 		}
987 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE);
988 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN);
989 		if (
990 #if IEEE80211_CHAN_MAX < 255
991 		    chan > IEEE80211_CHAN_MAX ||
992 #endif
993 		    isclr(ic->ic_chan_active, chan)) {
994 			IEEE80211_DPRINTF(("%s: ignore %s with invalid channel "
995 				"%u\n", __func__,
996 				ISPROBE(subtype) ? "probe response" : "beacon",
997 				chan));
998 			ic->ic_stats.is_rx_badchan++;
999 			return;
1000 		}
1001 		if (chan != bchan && ic->ic_phytype != IEEE80211_T_FH) {
1002 			/*
1003 			 * Frame was received on a channel different from the
1004 			 * one indicated in the DS params element id;
1005 			 * silently discard it.
1006 			 *
1007 			 * NB: this can happen due to signal leakage.
1008 			 *     But we should take it for FH phy because
1009 			 *     the rssi value should be correct even for
1010 			 *     different hop pattern in FH.
1011 			 */
1012 			IEEE80211_DPRINTF(("%s: ignore %s on channel %u marked "
1013 				"for channel %u\n", __func__,
1014 				ISPROBE(subtype) ? "probe response" : "beacon",
1015 				bchan, chan));
1016 			ic->ic_stats.is_rx_chanmismatch++;
1017 			return;
1018 		}
1019 
1020 		/*
1021 		 * Use mac and channel for lookup so we collect all
1022 		 * potential AP's when scanning.  Otherwise we may
1023 		 * see the same AP on multiple channels and will only
1024 		 * record the last one.  We could filter APs here based
1025 		 * on rssi, etc. but leave that to the end of the scan
1026 		 * so we can keep the selection criteria in one spot.
1027 		 * This may result in a bloat of the scanned AP list but
1028 		 * it shouldn't be too much.
1029 		 */
1030 		ni = ieee80211_lookup_node(ic, wh->i_addr2,
1031 				&ic->ic_channels[chan]);
1032 #ifdef IEEE80211_DEBUG
1033 		if (ieee80211_debug &&
1034 		    (ni == NULL || ic->ic_state == IEEE80211_S_SCAN)) {
1035 			printf("%s: %s%s on chan %u (bss chan %u) ",
1036 			    __func__, (ni == NULL ? "new " : ""),
1037 			    ISPROBE(subtype) ? "probe response" : "beacon",
1038 			    chan, bchan);
1039 			ieee80211_print_essid(ssid + 2, ssid[1]);
1040 			printf(" from %s\n", ether_sprintf(wh->i_addr2));
1041 			printf("%s: caps 0x%x bintval %u erp 0x%x\n",
1042 				__func__, le16toh(*(u_int16_t *)capinfo),
1043 				le16toh(*(u_int16_t *)bintval), erp);
1044 			if (country) {
1045 				int i;
1046 				printf("%s: country info", __func__);
1047 				for (i = 0; i < country[1]; i++)
1048 					printf(" %02x", country[i+2]);
1049 				printf("\n");
1050 			}
1051 		}
1052 #endif
1053 		if (ni == NULL) {
1054 			ni = ieee80211_alloc_node(ic, wh->i_addr2);
1055 			if (ni == NULL) {
1056 				ic->ic_stats.is_rx_nodealloc++;
1057 				return;
1058 			}
1059 			ni->ni_esslen = ssid[1];
1060 			memset(ni->ni_essid, 0, sizeof(ni->ni_essid));
1061 			memcpy(ni->ni_essid, ssid + 2, ssid[1]);
1062 		} else if (subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP) {
1063 			/*
1064 			 * Update ESSID at probe response to adopt hidden AP by
1065 			 * Lucent/Cisco, which announces null ESSID in beacon.
1066 			 */
1067 			ni->ni_esslen = ssid[1];
1068 			memset(ni->ni_essid, 0, sizeof(ni->ni_essid));
1069 			memcpy(ni->ni_essid, ssid + 2, ssid[1]);
1070 		}
1071 		IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
1072 		ni->ni_rssi = rssi;
1073 		ni->ni_rstamp = rstamp;
1074 		memcpy(ni->ni_tstamp, tstamp, sizeof(ni->ni_tstamp));
1075 		ni->ni_intval = le16toh(*(u_int16_t *)bintval);
1076 		ni->ni_capinfo = le16toh(*(u_int16_t *)capinfo);
1077 		/* XXX validate channel # */
1078 		ni->ni_chan = &ic->ic_channels[chan];
1079 		ni->ni_fhdwell = fhdwell;
1080 		ni->ni_fhindex = fhindex;
1081 		ni->ni_erp = erp;
1082 		/* NB: must be after ni_chan is setup */
1083 		ieee80211_setup_rates(ic, ni, rates, xrates, IEEE80211_F_DOSORT);
1084 		ieee80211_unref_node(&ni);
1085 		break;
1086 	}
1087 
1088 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ: {
1089 		u_int8_t rate;
1090 
1091 		if (ic->ic_opmode == IEEE80211_M_STA)
1092 			return;
1093 		if (ic->ic_state != IEEE80211_S_RUN)
1094 			return;
1095 
1096 		/*
1097 		 * prreq frame format
1098 		 *	[tlv] ssid
1099 		 *	[tlv] supported rates
1100 		 *	[tlv] extended supported rates
1101 		 */
1102 		ssid = rates = xrates = NULL;
1103 		while (frm < efrm) {
1104 			switch (*frm) {
1105 			case IEEE80211_ELEMID_SSID:
1106 				ssid = frm;
1107 				break;
1108 			case IEEE80211_ELEMID_RATES:
1109 				rates = frm;
1110 				break;
1111 			case IEEE80211_ELEMID_XRATES:
1112 				xrates = frm;
1113 				break;
1114 			}
1115 			frm += frm[1] + 2;
1116 		}
1117 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE);
1118 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN);
1119 		if (ssid[1] != 0 &&
1120 		    (ssid[1] != ic->ic_bss->ni_esslen ||
1121 		    memcmp(ssid + 2, ic->ic_bss->ni_essid, ic->ic_bss->ni_esslen) != 0)) {
1122 #ifdef IEEE80211_DEBUG
1123 			if (ieee80211_debug) {
1124 				printf("%s: ssid mismatch ", __func__);
1125 				ieee80211_print_essid(ssid + 2, ssid[1]);
1126 				printf(" from %s\n", ether_sprintf(wh->i_addr2));
1127 			}
1128 #endif
1129 			ic->ic_stats.is_rx_ssidmismatch++;
1130 			return;
1131 		}
1132 
1133 		if (ni == ic->ic_bss) {
1134 			ni = ieee80211_dup_bss(ic, wh->i_addr2);
1135 			if (ni == NULL) {
1136 				ic->ic_stats.is_rx_nodealloc++;
1137 				return;
1138 			}
1139 			IEEE80211_DPRINTF(("%s: new req from %s\n",
1140 				__func__, ether_sprintf(wh->i_addr2)));
1141 			allocbs = 1;
1142 		} else
1143 			allocbs = 0;
1144 		ni->ni_rssi = rssi;
1145 		ni->ni_rstamp = rstamp;
1146 		rate = ieee80211_setup_rates(ic, ni, rates, xrates,
1147 				IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE
1148 				| IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
1149 		if (rate & IEEE80211_RATE_BASIC) {
1150 			IEEE80211_DPRINTF(("%s: rate negotiation failed: %s\n",
1151 				__func__,ether_sprintf(wh->i_addr2)));
1152 		} else {
1153 			IEEE80211_SEND_MGMT(ic, ni,
1154 				IEEE80211_FC0_SUBTYPE_PROBE_RESP, 0);
1155 		}
1156 		if (allocbs) {
1157 			/* XXX just use free? */
1158 			if (ic->ic_opmode == IEEE80211_M_HOSTAP)
1159 				ieee80211_free_node(ic, ni);
1160 			else
1161 				ieee80211_unref_node(&ni);
1162 		}
1163 		break;
1164 	}
1165 
1166 	case IEEE80211_FC0_SUBTYPE_AUTH: {
1167 		u_int16_t algo, seq, status;
1168 		/*
1169 		 * auth frame format
1170 		 *	[2] algorithm
1171 		 *	[2] sequence
1172 		 *	[2] status
1173 		 *	[tlv*] challenge
1174 		 */
1175 		IEEE80211_VERIFY_LENGTH(efrm - frm, 6);
1176 		algo   = le16toh(*(u_int16_t *)frm);
1177 		seq    = le16toh(*(u_int16_t *)(frm + 2));
1178 		status = le16toh(*(u_int16_t *)(frm + 4));
1179 		IEEE80211_DPRINTF(("%s: auth %d seq %d from %s\n",
1180 		    __func__, algo, seq, ether_sprintf(wh->i_addr2)));
1181 
1182 		if (algo == IEEE80211_AUTH_ALG_SHARED)
1183 			ieee80211_auth_shared(ic, wh, frm + 6, efrm, ni, rssi,
1184 			    rstamp, seq, status);
1185 		else if (algo == IEEE80211_AUTH_ALG_OPEN)
1186 			ieee80211_auth_open(ic, wh, ni, rssi, rstamp, seq,
1187 			    status);
1188 		else {
1189 			IEEE80211_DPRINTF(("%s: unsupported authentication "
1190 				"algorithm %d from %s\n",
1191 				__func__, algo, ether_sprintf(wh->i_addr2)));
1192 			ic->ic_stats.is_rx_auth_unsupported++;
1193 			return;
1194 		}
1195 		break;
1196 	}
1197 
1198 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1199 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ: {
1200 		u_int16_t capinfo, bintval;
1201 
1202 		if (ic->ic_opmode != IEEE80211_M_HOSTAP ||
1203 		    (ic->ic_state != IEEE80211_S_RUN))
1204 			return;
1205 
1206 		if (subtype == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
1207 			reassoc = 1;
1208 			resp = IEEE80211_FC0_SUBTYPE_REASSOC_RESP;
1209 		} else {
1210 			reassoc = 0;
1211 			resp = IEEE80211_FC0_SUBTYPE_ASSOC_RESP;
1212 		}
1213 		/*
1214 		 * asreq frame format
1215 		 *	[2] capability information
1216 		 *	[2] listen interval
1217 		 *	[6*] current AP address (reassoc only)
1218 		 *	[tlv] ssid
1219 		 *	[tlv] supported rates
1220 		 *	[tlv] extended supported rates
1221 		 */
1222 		IEEE80211_VERIFY_LENGTH(efrm - frm, (reassoc ? 10 : 4));
1223 		if (!IEEE80211_ADDR_EQ(wh->i_addr3, ic->ic_bss->ni_bssid)) {
1224 			IEEE80211_DPRINTF(("%s: ignore other bss from %s\n",
1225 				__func__, ether_sprintf(wh->i_addr2)));
1226 			ic->ic_stats.is_rx_assoc_bss++;
1227 			return;
1228 		}
1229 		capinfo = le16toh(*(u_int16_t *)frm);	frm += 2;
1230 		bintval = le16toh(*(u_int16_t *)frm);	frm += 2;
1231 		if (reassoc)
1232 			frm += 6;	/* ignore current AP info */
1233 		ssid = rates = xrates = NULL;
1234 		while (frm < efrm) {
1235 			switch (*frm) {
1236 			case IEEE80211_ELEMID_SSID:
1237 				ssid = frm;
1238 				break;
1239 			case IEEE80211_ELEMID_RATES:
1240 				rates = frm;
1241 				break;
1242 			case IEEE80211_ELEMID_XRATES:
1243 				xrates = frm;
1244 				break;
1245 			}
1246 			frm += frm[1] + 2;
1247 		}
1248 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE);
1249 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN);
1250 		if (ssid[1] != ic->ic_bss->ni_esslen ||
1251 		    memcmp(ssid + 2, ic->ic_bss->ni_essid, ssid[1]) != 0) {
1252 #ifdef IEEE80211_DEBUG
1253 			if (ieee80211_debug) {
1254 				printf("%s: ssid mismatch ", __func__);
1255 				ieee80211_print_essid(ssid + 2, ssid[1]);
1256 				printf(" from %s\n", ether_sprintf(wh->i_addr2));
1257 			}
1258 #endif
1259 			ic->ic_stats.is_rx_ssidmismatch++;
1260 			return;
1261 		}
1262 		if (ni == ic->ic_bss) {
1263 			IEEE80211_DPRINTF(("%s: not authenticated for %s\n",
1264 				__func__, ether_sprintf(wh->i_addr2)));
1265 			ni = ieee80211_dup_bss(ic, wh->i_addr2);
1266 			if (ni != NULL) {
1267 				IEEE80211_SEND_MGMT(ic, ni,
1268 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
1269 				    IEEE80211_REASON_ASSOC_NOT_AUTHED);
1270 				ieee80211_free_node(ic, ni);
1271 			}
1272 			ic->ic_stats.is_rx_assoc_notauth++;
1273 			return;
1274 		}
1275 		/* discard challenge after association */
1276 		if (ni->ni_challenge != NULL) {
1277 			FREE(ni->ni_challenge, M_DEVBUF);
1278 			ni->ni_challenge = NULL;
1279 		}
1280 		/* XXX per-node cipher suite */
1281 		/* XXX some stations use the privacy bit for handling APs
1282 		       that suport both encrypted and unencrypted traffic */
1283 		if ((capinfo & IEEE80211_CAPINFO_ESS) == 0 ||
1284 		    (capinfo & IEEE80211_CAPINFO_PRIVACY) !=
1285 		    ((ic->ic_flags & IEEE80211_F_WEPON) ?
1286 		     IEEE80211_CAPINFO_PRIVACY : 0)) {
1287 			IEEE80211_DPRINTF(("%s: capability mismatch %x for %s\n",
1288 				__func__, capinfo, ether_sprintf(wh->i_addr2)));
1289 			IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1290 			ni->ni_associd = 0;
1291 			IEEE80211_SEND_MGMT(ic, ni, resp,
1292 				IEEE80211_STATUS_CAPINFO);
1293 			ic->ic_stats.is_rx_assoc_capmismatch++;
1294 			return;
1295 		}
1296 		ieee80211_setup_rates(ic, ni, rates, xrates,
1297 				IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE |
1298 				IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
1299 		if (ni->ni_rates.rs_nrates == 0) {
1300 			IEEE80211_DPRINTF(("%s: rate mismatch for %s\n",
1301 				__func__, ether_sprintf(wh->i_addr2)));
1302 			IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1303 			ni->ni_associd = 0;
1304 			IEEE80211_SEND_MGMT(ic, ni, resp,
1305 				IEEE80211_STATUS_BASIC_RATE);
1306 			ic->ic_stats.is_rx_assoc_norate++;
1307 			return;
1308 		}
1309 		ni->ni_rssi = rssi;
1310 		ni->ni_rstamp = rstamp;
1311 		ni->ni_intval = bintval;
1312 		ni->ni_capinfo = capinfo;
1313 		ni->ni_chan = ic->ic_bss->ni_chan;
1314 		ni->ni_fhdwell = ic->ic_bss->ni_fhdwell;
1315 		ni->ni_fhindex = ic->ic_bss->ni_fhindex;
1316 		if (ni->ni_associd == 0) {
1317 			u_int16_t aid;
1318 
1319 			/*
1320 			 * It would be clever to search the bitmap
1321 			 * more efficiently, but this will do for now.
1322 			 */
1323 			for (aid = 1; aid < ic->ic_max_aid; aid++) {
1324 				if (!IEEE80211_AID_ISSET(aid,
1325 				    ic->ic_aid_bitmap))
1326 					break;
1327 			}
1328 
1329 			if (ic->ic_bss->ni_associd >= ic->ic_max_aid) {
1330 				IEEE80211_SEND_MGMT(ic, ni, resp,
1331 				    IEEE80211_REASON_ASSOC_TOOMANY);
1332 				return;
1333 			} else {
1334 				ni->ni_associd = aid | 0xc000;
1335 				IEEE80211_AID_SET(ni->ni_associd,
1336 				    ic->ic_aid_bitmap);
1337 				newassoc = 1;
1338 			}
1339 		} else
1340 			newassoc = 0;
1341 		/* XXX for 11g must turn off short slot time if long
1342 	           slot time sta associates */
1343 		IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
1344 		if (ifp->if_flags & IFF_DEBUG)
1345 			if_printf(ifp, "station %s %s associated at aid %d\n",
1346 			    (newassoc ? "newly" : "already"),
1347 			    ether_sprintf(ni->ni_macaddr),
1348 			    ni->ni_associd & ~0xc000);
1349 		/* give driver a chance to setup state like ni_txrate */
1350 		if (ic->ic_newassoc)
1351 			(*ic->ic_newassoc)(ic, ni, newassoc);
1352 		break;
1353 	}
1354 
1355 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1356 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP: {
1357 		u_int16_t status;
1358 
1359 		if (ic->ic_opmode != IEEE80211_M_STA ||
1360 		    ic->ic_state != IEEE80211_S_ASSOC)
1361 			return;
1362 
1363 		/*
1364 		 * asresp frame format
1365 		 *	[2] capability information
1366 		 *	[2] status
1367 		 *	[2] association ID
1368 		 *	[tlv] supported rates
1369 		 *	[tlv] extended supported rates
1370 		 */
1371 		IEEE80211_VERIFY_LENGTH(efrm - frm, 6);
1372 		ni = ic->ic_bss;
1373 		ni->ni_capinfo = le16toh(*(u_int16_t *)frm);
1374 		frm += 2;
1375 
1376 		status = le16toh(*(u_int16_t *)frm);
1377 		frm += 2;
1378 		if (status != 0) {
1379 			if (ifp->if_flags & IFF_DEBUG)
1380 				if_printf(ifp,
1381 				    "association failed (reason %d) for %s\n",
1382 				    status, ether_sprintf(wh->i_addr3));
1383 			if (ni != ic->ic_bss)
1384 				ni->ni_fails++;
1385 			ic->ic_stats.is_rx_auth_fail++;
1386 			return;
1387 		}
1388 		ni->ni_associd = le16toh(*(u_int16_t *)frm);
1389 		frm += 2;
1390 
1391 		rates = xrates = NULL;
1392 		while (frm < efrm) {
1393 			switch (*frm) {
1394 			case IEEE80211_ELEMID_RATES:
1395 				rates = frm;
1396 				break;
1397 			case IEEE80211_ELEMID_XRATES:
1398 				xrates = frm;
1399 				break;
1400 			}
1401 			frm += frm[1] + 2;
1402 		}
1403 
1404 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE);
1405 		ieee80211_setup_rates(ic, ni, rates, xrates,
1406 				IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE |
1407 				IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
1408 		if (ni->ni_rates.rs_nrates != 0)
1409 			ieee80211_new_state(ic, IEEE80211_S_RUN,
1410 				wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
1411 		break;
1412 	}
1413 
1414 	case IEEE80211_FC0_SUBTYPE_DEAUTH: {
1415 		u_int16_t reason;
1416 		/*
1417 		 * deauth frame format
1418 		 *	[2] reason
1419 		 */
1420 		IEEE80211_VERIFY_LENGTH(efrm - frm, 2);
1421 		reason = le16toh(*(u_int16_t *)frm);
1422 		ic->ic_stats.is_rx_deauth++;
1423 		switch (ic->ic_opmode) {
1424 		case IEEE80211_M_STA:
1425 			ieee80211_new_state(ic, IEEE80211_S_AUTH,
1426 			    wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
1427 			break;
1428 		case IEEE80211_M_HOSTAP:
1429 			if (ni != ic->ic_bss) {
1430 				if (ifp->if_flags & IFF_DEBUG)
1431 					if_printf(ifp, "station %s deauthenticated"
1432 					    " by peer (reason %d)\n",
1433 					    ether_sprintf(ni->ni_macaddr), reason);
1434 				/* node will be free'd on return */
1435 				ieee80211_unref_node(&ni);
1436 			}
1437 			break;
1438 		default:
1439 			break;
1440 		}
1441 		break;
1442 	}
1443 
1444 	case IEEE80211_FC0_SUBTYPE_DISASSOC: {
1445 		u_int16_t reason;
1446 		/*
1447 		 * disassoc frame format
1448 		 *	[2] reason
1449 		 */
1450 		IEEE80211_VERIFY_LENGTH(efrm - frm, 2);
1451 		reason = le16toh(*(u_int16_t *)frm);
1452 		ic->ic_stats.is_rx_disassoc++;
1453 		switch (ic->ic_opmode) {
1454 		case IEEE80211_M_STA:
1455 			ieee80211_new_state(ic, IEEE80211_S_ASSOC,
1456 			    wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK);
1457 			break;
1458 		case IEEE80211_M_HOSTAP:
1459 			if (ni != ic->ic_bss) {
1460 				if (ifp->if_flags & IFF_DEBUG)
1461 					if_printf(ifp, "station %s disassociated"
1462 					    " by peer (reason %d)\n",
1463 					    ether_sprintf(ni->ni_macaddr), reason);
1464 				IEEE80211_AID_CLR(ni->ni_associd,
1465 				    ic->ic_aid_bitmap);
1466 				ni->ni_associd = 0;
1467 				/* XXX node reclaimed how? */
1468 			}
1469 			break;
1470 		default:
1471 			break;
1472 		}
1473 		break;
1474 	}
1475 	default:
1476 		IEEE80211_DPRINTF(("%s: mgmt frame with subtype 0x%x not "
1477 			"handled\n", __func__, subtype));
1478 		ic->ic_stats.is_rx_badsubtype++;
1479 		break;
1480 	}
1481 #undef ISPROBE
1482 }
1483 
1484 static void
1485 ieee80211_recv_pspoll(struct ieee80211com *ic, struct mbuf *m0, int rssi,
1486 		      u_int32_t rstamp)
1487 {
1488 	struct ifnet *ifp = &ic->ic_if;
1489 	struct ieee80211_frame *wh;
1490 	struct ieee80211_node *ni;
1491 	struct mbuf *m;
1492 	u_int16_t aid;
1493 
1494 	if (ic->ic_set_tim == NULL)  /* No powersaving functionality */
1495 		return;
1496 
1497 	wh = mtod(m0, struct ieee80211_frame *);
1498 
1499 	if ((ni = ieee80211_find_node(ic, wh->i_addr2)) == NULL) {
1500 		if (ifp->if_flags & IFF_DEBUG)
1501 			printf("%s: station %s sent bogus power save poll\n",
1502 			       ifp->if_xname, ether_sprintf(wh->i_addr2));
1503 		return;
1504 	}
1505 
1506 	memcpy(&aid, wh->i_dur, sizeof(wh->i_dur));
1507 	if ((aid & 0xc000) != 0xc000) {
1508 		if (ifp->if_flags & IFF_DEBUG)
1509 			printf("%s: station %s sent bogus aid %x\n",
1510 			       ifp->if_xname, ether_sprintf(wh->i_addr2), aid);
1511 		return;
1512 	}
1513 
1514 	if (aid != ni->ni_associd) {
1515 		if (ifp->if_flags & IFF_DEBUG)
1516 			printf("%s: station %s aid %x doesn't match pspoll "
1517 			       "aid %x\n",
1518 			       ifp->if_xname, ether_sprintf(wh->i_addr2),
1519 			       ni->ni_associd, aid);
1520 		return;
1521 	}
1522 
1523 	/* Okay, take the first queued packet and put it out... */
1524 
1525 	IF_DEQUEUE(&ni->ni_savedq, m);
1526 	if (m == NULL) {
1527 		if (ifp->if_flags & IFF_DEBUG)
1528 			printf("%s: station %s sent pspoll, "
1529 			       "but no packets are saved\n",
1530 			       ifp->if_xname, ether_sprintf(wh->i_addr2));
1531 		return;
1532 	}
1533 	wh = mtod(m, struct ieee80211_frame *);
1534 
1535 	/*
1536 	 * If this is the last packet, turn off the TIM fields.
1537 	 * If there are more packets, set the more packets bit.
1538 	 */
1539 
1540 	if (IF_IS_EMPTY(&ni->ni_savedq)) {
1541 		if (ic->ic_set_tim)
1542 			ic->ic_set_tim(ic, ni->ni_associd, 0);
1543 	} else {
1544 		wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
1545 	}
1546 
1547 	if (ifp->if_flags & IFF_DEBUG)
1548 		printf("%s: enqueued power saving packet for station %s\n",
1549 		       ifp->if_xname, ether_sprintf(ni->ni_macaddr));
1550 
1551 	IF_ENQUEUE(&ic->ic_pwrsaveq, m);
1552 	(*ifp->if_start)(ifp);
1553 }
1554 #undef IEEE80211_VERIFY_LENGTH
1555 #undef IEEE80211_VERIFY_ELEMENT
1556