xref: /freebsd/sys/net80211/ieee80211_adhoc.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
1 /*-
2  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 #ifdef __FreeBSD__
28 __FBSDID("$FreeBSD$");
29 #endif
30 
31 /*
32  * IEEE 802.11 IBSS mode support.
33  */
34 #include "opt_inet.h"
35 #include "opt_wlan.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/mbuf.h>
40 #include <sys/malloc.h>
41 #include <sys/kernel.h>
42 
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/endian.h>
46 #include <sys/errno.h>
47 #include <sys/proc.h>
48 #include <sys/sysctl.h>
49 
50 #include <net/if.h>
51 #include <net/if_media.h>
52 #include <net/if_llc.h>
53 #include <net/ethernet.h>
54 
55 #include <net/bpf.h>
56 
57 #include <net80211/ieee80211_var.h>
58 #include <net80211/ieee80211_adhoc.h>
59 #include <net80211/ieee80211_input.h>
60 #ifdef IEEE80211_SUPPORT_SUPERG
61 #include <net80211/ieee80211_superg.h>
62 #endif
63 #ifdef IEEE80211_SUPPORT_TDMA
64 #include <net80211/ieee80211_tdma.h>
65 #endif
66 
67 #define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
68 
69 static	void adhoc_vattach(struct ieee80211vap *);
70 static	int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
71 static int adhoc_input(struct ieee80211_node *, struct mbuf *, int, int);
72 static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
73 	int subtype, int, int);
74 static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
75 	int subtype, int, int);
76 static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
77 
78 void
79 ieee80211_adhoc_attach(struct ieee80211com *ic)
80 {
81 	ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
82 	ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
83 }
84 
85 void
86 ieee80211_adhoc_detach(struct ieee80211com *ic)
87 {
88 }
89 
90 static void
91 adhoc_vdetach(struct ieee80211vap *vap)
92 {
93 }
94 
95 static void
96 adhoc_vattach(struct ieee80211vap *vap)
97 {
98 	vap->iv_newstate = adhoc_newstate;
99 	vap->iv_input = adhoc_input;
100 	if (vap->iv_opmode == IEEE80211_M_IBSS)
101 		vap->iv_recv_mgmt = adhoc_recv_mgmt;
102 	else
103 		vap->iv_recv_mgmt = ahdemo_recv_mgmt;
104 	vap->iv_recv_ctl = adhoc_recv_ctl;
105 	vap->iv_opdetach = adhoc_vdetach;
106 #ifdef IEEE80211_SUPPORT_TDMA
107 	/*
108 	 * Throw control to tdma support.  Note we do this
109 	 * after setting up our callbacks so it can piggyback
110 	 * on top of us.
111 	 */
112 	if (vap->iv_caps & IEEE80211_C_TDMA)
113 		ieee80211_tdma_vattach(vap);
114 #endif
115 }
116 
117 static void
118 sta_leave(void *arg, struct ieee80211_node *ni)
119 {
120 	struct ieee80211vap *vap = arg;
121 
122 	if (ni->ni_vap == vap && ni != vap->iv_bss)
123 		ieee80211_node_leave(ni);
124 }
125 
126 /*
127  * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
128  */
129 static int
130 adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
131 {
132 	struct ieee80211com *ic = vap->iv_ic;
133 	struct ieee80211_node *ni;
134 	enum ieee80211_state ostate;
135 
136 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
137 
138 	ostate = vap->iv_state;
139 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
140 	    __func__, ieee80211_state_name[ostate],
141 	    ieee80211_state_name[nstate], arg);
142 	vap->iv_state = nstate;			/* state transition */
143 	if (ostate != IEEE80211_S_SCAN)
144 		ieee80211_cancel_scan(vap);	/* background scan */
145 	ni = vap->iv_bss;			/* NB: no reference held */
146 	switch (nstate) {
147 	case IEEE80211_S_INIT:
148 		switch (ostate) {
149 		case IEEE80211_S_SCAN:
150 			ieee80211_cancel_scan(vap);
151 			break;
152 		default:
153 			break;
154 		}
155 		if (ostate != IEEE80211_S_INIT) {
156 			/* NB: optimize INIT -> INIT case */
157 			ieee80211_reset_bss(vap);
158 		}
159 		break;
160 	case IEEE80211_S_SCAN:
161 		switch (ostate) {
162 		case IEEE80211_S_RUN:		/* beacon miss */
163 			/* purge station table; entries are stale */
164 			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
165 			/* fall thru... */
166 		case IEEE80211_S_INIT:
167 			if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
168 			    !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
169 				/*
170 				 * Already have a channel; bypass the
171 				 * scan and startup immediately.
172 				 */
173 				ieee80211_create_ibss(vap, vap->iv_des_chan);
174 				break;
175 			}
176 			/*
177 			 * Initiate a scan.  We can come here as a result
178 			 * of an IEEE80211_IOC_SCAN_REQ too in which case
179 			 * the vap will be marked with IEEE80211_FEXT_SCANREQ
180 			 * and the scan request parameters will be present
181 			 * in iv_scanreq.  Otherwise we do the default.
182 			 */
183 			if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
184 				ieee80211_check_scan(vap,
185 				    vap->iv_scanreq_flags,
186 				    vap->iv_scanreq_duration,
187 				    vap->iv_scanreq_mindwell,
188 				    vap->iv_scanreq_maxdwell,
189 				    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
190 				vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
191 			} else
192 				ieee80211_check_scan_current(vap);
193 			break;
194 		case IEEE80211_S_SCAN:
195 			/*
196 			 * This can happen because of a change in state
197 			 * that requires a reset.  Trigger a new scan
198 			 * unless we're in manual roaming mode in which
199 			 * case an application must issue an explicit request.
200 			 */
201 			if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
202 				ieee80211_check_scan_current(vap);
203 			break;
204 		default:
205 			goto invalid;
206 		}
207 		break;
208 	case IEEE80211_S_RUN:
209 		if (vap->iv_flags & IEEE80211_F_WPA) {
210 			/* XXX validate prerequisites */
211 		}
212 		switch (ostate) {
213 		case IEEE80211_S_SCAN:
214 #ifdef IEEE80211_DEBUG
215 			if (ieee80211_msg_debug(vap)) {
216 				ieee80211_note(vap,
217 				    "synchronized with %s ssid ",
218 				    ether_sprintf(ni->ni_bssid));
219 				ieee80211_print_essid(vap->iv_bss->ni_essid,
220 				    ni->ni_esslen);
221 				/* XXX MCS/HT */
222 				printf(" channel %d start %uMb\n",
223 				    ieee80211_chan2ieee(ic, ic->ic_curchan),
224 				    IEEE80211_RATE2MBS(ni->ni_txrate));
225 			}
226 #endif
227 			break;
228 		default:
229 			goto invalid;
230 		}
231 		/*
232 		 * When 802.1x is not in use mark the port authorized
233 		 * at this point so traffic can flow.
234 		 */
235 		if (ni->ni_authmode != IEEE80211_AUTH_8021X)
236 			ieee80211_node_authorize(ni);
237 		/*
238 		 * Fake association when joining an existing bss.
239 		 */
240 		if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
241 		    ic->ic_newassoc != NULL)
242 			ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
243 		break;
244 	case IEEE80211_S_SLEEP:
245 		ieee80211_sta_pwrsave(vap, 0);
246 		break;
247 	default:
248 	invalid:
249 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
250 		    "%s: unexpected state transition %s -> %s\n", __func__,
251 		    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
252 		break;
253 	}
254 	return 0;
255 }
256 
257 /*
258  * Decide if a received management frame should be
259  * printed when debugging is enabled.  This filters some
260  * of the less interesting frames that come frequently
261  * (e.g. beacons).
262  */
263 static __inline int
264 doprint(struct ieee80211vap *vap, int subtype)
265 {
266 	switch (subtype) {
267 	case IEEE80211_FC0_SUBTYPE_BEACON:
268 		return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
269 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
270 		return 1;
271 	}
272 	return 1;
273 }
274 
275 /*
276  * Process a received frame.  The node associated with the sender
277  * should be supplied.  If nothing was found in the node table then
278  * the caller is assumed to supply a reference to iv_bss instead.
279  * The RSSI and a timestamp are also supplied.  The RSSI data is used
280  * during AP scanning to select a AP to associate with; it can have
281  * any units so long as values have consistent units and higher values
282  * mean ``better signal''.  The receive timestamp is currently not used
283  * by the 802.11 layer.
284  */
285 static int
286 adhoc_input(struct ieee80211_node *ni, struct mbuf *m, int rssi, int nf)
287 {
288 #define	HAS_SEQ(type)	((type & 0x4) == 0)
289 	struct ieee80211vap *vap = ni->ni_vap;
290 	struct ieee80211com *ic = ni->ni_ic;
291 	struct ifnet *ifp = vap->iv_ifp;
292 	struct ieee80211_frame *wh;
293 	struct ieee80211_key *key;
294 	struct ether_header *eh;
295 	int hdrspace, need_tap = 1;	/* mbuf need to be tapped. */
296 	uint8_t dir, type, subtype, qos;
297 	uint8_t *bssid;
298 	uint16_t rxseq;
299 
300 	if (m->m_flags & M_AMPDU_MPDU) {
301 		/*
302 		 * Fastpath for A-MPDU reorder q resubmission.  Frames
303 		 * w/ M_AMPDU_MPDU marked have already passed through
304 		 * here but were received out of order and been held on
305 		 * the reorder queue.  When resubmitted they are marked
306 		 * with the M_AMPDU_MPDU flag and we can bypass most of
307 		 * the normal processing.
308 		 */
309 		wh = mtod(m, struct ieee80211_frame *);
310 		type = IEEE80211_FC0_TYPE_DATA;
311 		dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
312 		subtype = IEEE80211_FC0_SUBTYPE_QOS;
313 		hdrspace = ieee80211_hdrspace(ic, wh);	/* XXX optimize? */
314 		goto resubmit_ampdu;
315 	}
316 
317 	KASSERT(ni != NULL, ("null node"));
318 	ni->ni_inact = ni->ni_inact_reload;
319 
320 	type = -1;			/* undefined */
321 
322 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
323 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
324 		    ni->ni_macaddr, NULL,
325 		    "too short (1): len %u", m->m_pkthdr.len);
326 		vap->iv_stats.is_rx_tooshort++;
327 		goto out;
328 	}
329 	/*
330 	 * Bit of a cheat here, we use a pointer for a 3-address
331 	 * frame format but don't reference fields past outside
332 	 * ieee80211_frame_min w/o first validating the data is
333 	 * present.
334 	 */
335 	wh = mtod(m, struct ieee80211_frame *);
336 
337 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
338 	    IEEE80211_FC0_VERSION_0) {
339 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
340 		    ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
341 		    wh->i_fc[0], wh->i_fc[1]);
342 		vap->iv_stats.is_rx_badversion++;
343 		goto err;
344 	}
345 
346 	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
347 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
348 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
349 	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
350 		if (dir != IEEE80211_FC1_DIR_NODS)
351 			bssid = wh->i_addr1;
352 		else if (type == IEEE80211_FC0_TYPE_CTL)
353 			bssid = wh->i_addr1;
354 		else {
355 			if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
356 				IEEE80211_DISCARD_MAC(vap,
357 				    IEEE80211_MSG_ANY, ni->ni_macaddr,
358 				    NULL, "too short (2): len %u",
359 				    m->m_pkthdr.len);
360 				vap->iv_stats.is_rx_tooshort++;
361 				goto out;
362 			}
363 			bssid = wh->i_addr3;
364 		}
365 		/*
366 		 * Validate the bssid.
367 		 */
368 		if (!IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
369 		    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
370 			/* not interested in */
371 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
372 			    bssid, NULL, "%s", "not to bss");
373 			vap->iv_stats.is_rx_wrongbss++;
374 			goto out;
375 		}
376 		/*
377 		 * Data frame, cons up a node when it doesn't
378 		 * exist. This should probably done after an ACL check.
379 		 */
380 		if (type == IEEE80211_FC0_TYPE_DATA &&
381 		    ni == vap->iv_bss &&
382 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
383 			/*
384 			 * Beware of frames that come in too early; we
385 			 * can receive broadcast frames and creating sta
386 			 * entries will blow up because there is no bss
387 			 * channel yet.
388 			 */
389 			if (vap->iv_state != IEEE80211_S_RUN) {
390 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
391 				    wh, "data", "not in RUN state (%s)",
392 				    ieee80211_state_name[vap->iv_state]);
393 				vap->iv_stats.is_rx_badstate++;
394 				goto err;
395 			}
396 			/*
397 			 * Fake up a node for this newly
398 			 * discovered member of the IBSS.
399 			 */
400 			ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
401 			if (ni == NULL) {
402 				/* NB: stat kept for alloc failure */
403 				goto err;
404 			}
405 		}
406 		IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
407 		ni->ni_noise = nf;
408 		if (HAS_SEQ(type)) {
409 			uint8_t tid = ieee80211_gettid(wh);
410 			if (IEEE80211_QOS_HAS_SEQ(wh) &&
411 			    TID_TO_WME_AC(tid) >= WME_AC_VI)
412 				ic->ic_wme.wme_hipri_traffic++;
413 			rxseq = le16toh(*(uint16_t *)wh->i_seq);
414 			if (! ieee80211_check_rxseq(ni, wh)) {
415 				/* duplicate, discard */
416 				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
417 				    bssid, "duplicate",
418 				    "seqno <%u,%u> fragno <%u,%u> tid %u",
419 				    rxseq >> IEEE80211_SEQ_SEQ_SHIFT,
420 				    ni->ni_rxseqs[tid] >>
421 					IEEE80211_SEQ_SEQ_SHIFT,
422 				    rxseq & IEEE80211_SEQ_FRAG_MASK,
423 				    ni->ni_rxseqs[tid] &
424 					IEEE80211_SEQ_FRAG_MASK,
425 				    tid);
426 				vap->iv_stats.is_rx_dup++;
427 				IEEE80211_NODE_STAT(ni, rx_dup);
428 				goto out;
429 			}
430 			ni->ni_rxseqs[tid] = rxseq;
431 		}
432 	}
433 
434 	switch (type) {
435 	case IEEE80211_FC0_TYPE_DATA:
436 		hdrspace = ieee80211_hdrspace(ic, wh);
437 		if (m->m_len < hdrspace &&
438 		    (m = m_pullup(m, hdrspace)) == NULL) {
439 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
440 			    ni->ni_macaddr, NULL,
441 			    "data too short: expecting %u", hdrspace);
442 			vap->iv_stats.is_rx_tooshort++;
443 			goto out;		/* XXX */
444 		}
445 		if (dir != IEEE80211_FC1_DIR_NODS) {
446 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
447 			    wh, "data", "incorrect dir 0x%x", dir);
448 			vap->iv_stats.is_rx_wrongdir++;
449 			goto out;
450 		}
451 		/* XXX no power-save support */
452 
453 		/*
454 		 * Handle A-MPDU re-ordering.  If the frame is to be
455 		 * processed directly then ieee80211_ampdu_reorder
456 		 * will return 0; otherwise it has consumed the mbuf
457 		 * and we should do nothing more with it.
458 		 */
459 		if ((m->m_flags & M_AMPDU) &&
460 		    ieee80211_ampdu_reorder(ni, m) != 0) {
461 			m = NULL;
462 			goto out;
463 		}
464 	resubmit_ampdu:
465 
466 		/*
467 		 * Handle privacy requirements.  Note that we
468 		 * must not be preempted from here until after
469 		 * we (potentially) call ieee80211_crypto_demic;
470 		 * otherwise we may violate assumptions in the
471 		 * crypto cipher modules used to do delayed update
472 		 * of replay sequence numbers.
473 		 */
474 		if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
475 			if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
476 				/*
477 				 * Discard encrypted frames when privacy is off.
478 				 */
479 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
480 				    wh, "WEP", "%s", "PRIVACY off");
481 				vap->iv_stats.is_rx_noprivacy++;
482 				IEEE80211_NODE_STAT(ni, rx_noprivacy);
483 				goto out;
484 			}
485 			key = ieee80211_crypto_decap(ni, m, hdrspace);
486 			if (key == NULL) {
487 				/* NB: stats+msgs handled in crypto_decap */
488 				IEEE80211_NODE_STAT(ni, rx_wepfail);
489 				goto out;
490 			}
491 			wh = mtod(m, struct ieee80211_frame *);
492 			wh->i_fc[1] &= ~IEEE80211_FC1_WEP;
493 		} else {
494 			/* XXX M_WEP and IEEE80211_F_PRIVACY */
495 			key = NULL;
496 		}
497 
498 		/*
499 		 * Save QoS bits for use below--before we strip the header.
500 		 */
501 		if (subtype == IEEE80211_FC0_SUBTYPE_QOS) {
502 			qos = (dir == IEEE80211_FC1_DIR_DSTODS) ?
503 			    ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0] :
504 			    ((struct ieee80211_qosframe *)wh)->i_qos[0];
505 		} else
506 			qos = 0;
507 
508 		/*
509 		 * Next up, any fragmentation.
510 		 */
511 		if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
512 			m = ieee80211_defrag(ni, m, hdrspace);
513 			if (m == NULL) {
514 				/* Fragment dropped or frame not complete yet */
515 				goto out;
516 			}
517 		}
518 		wh = NULL;		/* no longer valid, catch any uses */
519 
520 		/*
521 		 * Next strip any MSDU crypto bits.
522 		 */
523 		if (key != NULL && !ieee80211_crypto_demic(vap, key, m, 0)) {
524 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
525 			    ni->ni_macaddr, "data", "%s", "demic error");
526 			vap->iv_stats.is_rx_demicfail++;
527 			IEEE80211_NODE_STAT(ni, rx_demicfail);
528 			goto out;
529 		}
530 
531 		/* copy to listener after decrypt */
532 		if (ieee80211_radiotap_active_vap(vap))
533 			ieee80211_radiotap_rx(vap, m);
534 		need_tap = 0;
535 
536 		/*
537 		 * Finally, strip the 802.11 header.
538 		 */
539 		m = ieee80211_decap(vap, m, hdrspace);
540 		if (m == NULL) {
541 			/* XXX mask bit to check for both */
542 			/* don't count Null data frames as errors */
543 			if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
544 			    subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
545 				goto out;
546 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
547 			    ni->ni_macaddr, "data", "%s", "decap error");
548 			vap->iv_stats.is_rx_decap++;
549 			IEEE80211_NODE_STAT(ni, rx_decap);
550 			goto err;
551 		}
552 		eh = mtod(m, struct ether_header *);
553 		if (!ieee80211_node_is_authorized(ni)) {
554 			/*
555 			 * Deny any non-PAE frames received prior to
556 			 * authorization.  For open/shared-key
557 			 * authentication the port is mark authorized
558 			 * after authentication completes.  For 802.1x
559 			 * the port is not marked authorized by the
560 			 * authenticator until the handshake has completed.
561 			 */
562 			if (eh->ether_type != htons(ETHERTYPE_PAE)) {
563 				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
564 				    eh->ether_shost, "data",
565 				    "unauthorized port: ether type 0x%x len %u",
566 				    eh->ether_type, m->m_pkthdr.len);
567 				vap->iv_stats.is_rx_unauth++;
568 				IEEE80211_NODE_STAT(ni, rx_unauth);
569 				goto err;
570 			}
571 		} else {
572 			/*
573 			 * When denying unencrypted frames, discard
574 			 * any non-PAE frames received without encryption.
575 			 */
576 			if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
577 			    (key == NULL && (m->m_flags & M_WEP) == 0) &&
578 			    eh->ether_type != htons(ETHERTYPE_PAE)) {
579 				/*
580 				 * Drop unencrypted frames.
581 				 */
582 				vap->iv_stats.is_rx_unencrypted++;
583 				IEEE80211_NODE_STAT(ni, rx_unencrypted);
584 				goto out;
585 			}
586 		}
587 		/* XXX require HT? */
588 		if (qos & IEEE80211_QOS_AMSDU) {
589 			m = ieee80211_decap_amsdu(ni, m);
590 			if (m == NULL)
591 				return IEEE80211_FC0_TYPE_DATA;
592 		} else {
593 #ifdef IEEE80211_SUPPORT_SUPERG
594 			m = ieee80211_decap_fastframe(vap, ni, m);
595 			if (m == NULL)
596 				return IEEE80211_FC0_TYPE_DATA;
597 #endif
598 		}
599 		if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
600 			ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
601 		else
602 			ieee80211_deliver_data(vap, ni, m);
603 		return IEEE80211_FC0_TYPE_DATA;
604 
605 	case IEEE80211_FC0_TYPE_MGT:
606 		vap->iv_stats.is_rx_mgmt++;
607 		IEEE80211_NODE_STAT(ni, rx_mgmt);
608 		if (dir != IEEE80211_FC1_DIR_NODS) {
609 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
610 			    wh, "data", "incorrect dir 0x%x", dir);
611 			vap->iv_stats.is_rx_wrongdir++;
612 			goto err;
613 		}
614 		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
615 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
616 			    ni->ni_macaddr, "mgt", "too short: len %u",
617 			    m->m_pkthdr.len);
618 			vap->iv_stats.is_rx_tooshort++;
619 			goto out;
620 		}
621 #ifdef IEEE80211_DEBUG
622 		if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
623 		    ieee80211_msg_dumppkts(vap)) {
624 			if_printf(ifp, "received %s from %s rssi %d\n",
625 			    ieee80211_mgt_subtype_name[subtype >>
626 				IEEE80211_FC0_SUBTYPE_SHIFT],
627 			    ether_sprintf(wh->i_addr2), rssi);
628 		}
629 #endif
630 		if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
631 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
632 			    wh, NULL, "%s", "WEP set but not permitted");
633 			vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
634 			goto out;
635 		}
636 		vap->iv_recv_mgmt(ni, m, subtype, rssi, nf);
637 		goto out;
638 
639 	case IEEE80211_FC0_TYPE_CTL:
640 		vap->iv_stats.is_rx_ctl++;
641 		IEEE80211_NODE_STAT(ni, rx_ctrl);
642 		vap->iv_recv_ctl(ni, m, subtype);
643 		goto out;
644 
645 	default:
646 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
647 		    wh, "bad", "frame type 0x%x", type);
648 		/* should not come here */
649 		break;
650 	}
651 err:
652 	ifp->if_ierrors++;
653 out:
654 	if (m != NULL) {
655 		if (need_tap && ieee80211_radiotap_active_vap(vap))
656 			ieee80211_radiotap_rx(vap, m);
657 		m_freem(m);
658 	}
659 	return type;
660 }
661 
662 static int
663 is11bclient(const uint8_t *rates, const uint8_t *xrates)
664 {
665 	static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
666 	int i;
667 
668 	/* NB: the 11b clients we care about will not have xrates */
669 	if (xrates != NULL || rates == NULL)
670 		return 0;
671 	for (i = 0; i < rates[1]; i++) {
672 		int r = rates[2+i] & IEEE80211_RATE_VAL;
673 		if (r > 2*11 || ((1<<r) & brates) == 0)
674 			return 0;
675 	}
676 	return 1;
677 }
678 
679 static void
680 adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
681 	int subtype, int rssi, int nf)
682 {
683 	struct ieee80211vap *vap = ni->ni_vap;
684 	struct ieee80211com *ic = ni->ni_ic;
685 	struct ieee80211_frame *wh;
686 	uint8_t *frm, *efrm, *sfrm;
687 	uint8_t *ssid, *rates, *xrates;
688 
689 	wh = mtod(m0, struct ieee80211_frame *);
690 	frm = (uint8_t *)&wh[1];
691 	efrm = mtod(m0, uint8_t *) + m0->m_len;
692 	switch (subtype) {
693 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
694 	case IEEE80211_FC0_SUBTYPE_BEACON: {
695 		struct ieee80211_scanparams scan;
696 		/*
697 		 * We process beacon/probe response
698 		 * frames to discover neighbors.
699 		 */
700 		if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
701 			return;
702 		/*
703 		 * Count frame now that we know it's to be processed.
704 		 */
705 		if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
706 			vap->iv_stats.is_rx_beacon++;		/* XXX remove */
707 			IEEE80211_NODE_STAT(ni, rx_beacons);
708 		} else
709 			IEEE80211_NODE_STAT(ni, rx_proberesp);
710 		/*
711 		 * If scanning, just pass information to the scan module.
712 		 */
713 		if (ic->ic_flags & IEEE80211_F_SCAN) {
714 			if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
715 				/*
716 				 * Actively scanning a channel marked passive;
717 				 * send a probe request now that we know there
718 				 * is 802.11 traffic present.
719 				 *
720 				 * XXX check if the beacon we recv'd gives
721 				 * us what we need and suppress the probe req
722 				 */
723 				ieee80211_probe_curchan(vap, 1);
724 				ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
725 			}
726 			ieee80211_add_scan(vap, &scan, wh, subtype, rssi, nf);
727 			return;
728 		}
729 		if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
730 			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
731 				/*
732 				 * Create a new entry in the neighbor table.
733 				 */
734 				ni = ieee80211_add_neighbor(vap, wh, &scan);
735 			} else if (ni->ni_capinfo == 0) {
736 				/*
737 				 * Update faked node created on transmit.
738 				 * Note this also updates the tsf.
739 				 */
740 				ieee80211_init_neighbor(ni, wh, &scan);
741 			} else {
742 				/*
743 				 * Record tsf for potential resync.
744 				 */
745 				memcpy(ni->ni_tstamp.data, scan.tstamp,
746 					sizeof(ni->ni_tstamp));
747 			}
748 			if (ni != NULL) {
749 				IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
750 				ni->ni_noise = nf;
751 			}
752 		}
753 		break;
754 	}
755 
756 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
757 		if (vap->iv_state != IEEE80211_S_RUN) {
758 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
759 			    wh, NULL, "wrong state %s",
760 			    ieee80211_state_name[vap->iv_state]);
761 			vap->iv_stats.is_rx_mgtdiscard++;
762 			return;
763 		}
764 		if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
765 			/* frame must be directed */
766 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
767 			    wh, NULL, "%s", "not unicast");
768 			vap->iv_stats.is_rx_mgtdiscard++;	/* XXX stat */
769 			return;
770 		}
771 
772 		/*
773 		 * prreq frame format
774 		 *	[tlv] ssid
775 		 *	[tlv] supported rates
776 		 *	[tlv] extended supported rates
777 		 */
778 		ssid = rates = xrates = NULL;
779 		sfrm = frm;
780 		while (efrm - frm > 1) {
781 			IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
782 			switch (*frm) {
783 			case IEEE80211_ELEMID_SSID:
784 				ssid = frm;
785 				break;
786 			case IEEE80211_ELEMID_RATES:
787 				rates = frm;
788 				break;
789 			case IEEE80211_ELEMID_XRATES:
790 				xrates = frm;
791 				break;
792 			}
793 			frm += frm[1] + 2;
794 		}
795 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
796 		if (xrates != NULL)
797 			IEEE80211_VERIFY_ELEMENT(xrates,
798 				IEEE80211_RATE_MAXSIZE - rates[1], return);
799 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
800 		IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
801 		if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
802 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
803 			    wh, NULL,
804 			    "%s", "no ssid with ssid suppression enabled");
805 			vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
806 			return;
807 		}
808 
809 		/* XXX find a better class or define it's own */
810 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
811 		    "%s", "recv probe req");
812 		/*
813 		 * Some legacy 11b clients cannot hack a complete
814 		 * probe response frame.  When the request includes
815 		 * only a bare-bones rate set, communicate this to
816 		 * the transmit side.
817 		 */
818 		ieee80211_send_proberesp(vap, wh->i_addr2,
819 		    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
820 		break;
821 
822 	case IEEE80211_FC0_SUBTYPE_ACTION:
823 	case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
824 		if (ni == vap->iv_bss) {
825 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
826 			    wh, NULL, "%s", "unknown node");
827 			vap->iv_stats.is_rx_mgtdiscard++;
828 		} else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
829 		    !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
830 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
831 			    wh, NULL, "%s", "not for us");
832 			vap->iv_stats.is_rx_mgtdiscard++;
833 		} else if (vap->iv_state != IEEE80211_S_RUN) {
834 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
835 			    wh, NULL, "wrong state %s",
836 			    ieee80211_state_name[vap->iv_state]);
837 			vap->iv_stats.is_rx_mgtdiscard++;
838 		} else {
839 			if (ieee80211_parse_action(ni, m0) == 0)
840 				(void)ic->ic_recv_action(ni, wh, frm, efrm);
841 		}
842 		break;
843 
844 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
845 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
846 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
847 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
848 	case IEEE80211_FC0_SUBTYPE_ATIM:
849 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
850 	case IEEE80211_FC0_SUBTYPE_AUTH:
851 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
852 		IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
853 		    wh, NULL, "%s", "not handled");
854 		vap->iv_stats.is_rx_mgtdiscard++;
855 		break;
856 
857 	default:
858 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
859 		    wh, "mgt", "subtype 0x%x not handled", subtype);
860 		vap->iv_stats.is_rx_badsubtype++;
861 		break;
862 	}
863 }
864 #undef IEEE80211_VERIFY_LENGTH
865 #undef IEEE80211_VERIFY_ELEMENT
866 
867 static void
868 ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
869 	int subtype, int rssi, int nf)
870 {
871 	struct ieee80211vap *vap = ni->ni_vap;
872 	struct ieee80211com *ic = ni->ni_ic;
873 	struct ieee80211_frame *wh;
874 
875 	/*
876 	 * Process management frames when scanning; useful for doing
877 	 * a site-survey.
878 	 */
879 	if (ic->ic_flags & IEEE80211_F_SCAN)
880 		adhoc_recv_mgmt(ni, m0, subtype, rssi, nf);
881 	else {
882 		wh = mtod(m0, struct ieee80211_frame *);
883 		switch (subtype) {
884 		case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
885 		case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
886 		case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
887 		case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
888 		case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
889 		case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
890 		case IEEE80211_FC0_SUBTYPE_BEACON:
891 		case IEEE80211_FC0_SUBTYPE_ATIM:
892 		case IEEE80211_FC0_SUBTYPE_DISASSOC:
893 		case IEEE80211_FC0_SUBTYPE_AUTH:
894 		case IEEE80211_FC0_SUBTYPE_DEAUTH:
895 		case IEEE80211_FC0_SUBTYPE_ACTION:
896 		case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
897 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
898 			     wh, NULL, "%s", "not handled");
899 			vap->iv_stats.is_rx_mgtdiscard++;
900 			break;
901 		default:
902 			IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
903 			     wh, "mgt", "subtype 0x%x not handled", subtype);
904 			vap->iv_stats.is_rx_badsubtype++;
905 			break;
906 		}
907 	}
908 }
909 
910 static void
911 adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
912 {
913 
914 	switch (subtype) {
915 	case IEEE80211_FC0_SUBTYPE_BAR:
916 		ieee80211_recv_bar(ni, m);
917 		break;
918 	}
919 }
920