xref: /freebsd/sys/net80211/ieee80211_adhoc.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007-2009 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #ifdef __FreeBSD__
30 __FBSDID("$FreeBSD$");
31 #endif
32 
33 /*
34  * IEEE 802.11 IBSS mode support.
35  */
36 #include "opt_inet.h"
37 #include "opt_wlan.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/mbuf.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/endian.h>
48 #include <sys/errno.h>
49 #include <sys/proc.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/if_media.h>
55 #include <net/if_llc.h>
56 #include <net/ethernet.h>
57 
58 #include <net/bpf.h>
59 
60 #include <net80211/ieee80211_var.h>
61 #include <net80211/ieee80211_adhoc.h>
62 #include <net80211/ieee80211_input.h>
63 #ifdef IEEE80211_SUPPORT_SUPERG
64 #include <net80211/ieee80211_superg.h>
65 #endif
66 #ifdef IEEE80211_SUPPORT_TDMA
67 #include <net80211/ieee80211_tdma.h>
68 #endif
69 #include <net80211/ieee80211_sta.h>
70 
71 #define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
72 
73 static	void adhoc_vattach(struct ieee80211vap *);
74 static	int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
75 static int adhoc_input(struct ieee80211_node *, struct mbuf *,
76 	    const struct ieee80211_rx_stats *, int, int);
77 static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
78 	int subtype, const struct ieee80211_rx_stats *, int, int);
79 static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
80 	    int subtype, const struct ieee80211_rx_stats *rxs, int, int);
81 static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
82 
83 void
84 ieee80211_adhoc_attach(struct ieee80211com *ic)
85 {
86 	ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
87 	ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
88 }
89 
90 void
91 ieee80211_adhoc_detach(struct ieee80211com *ic)
92 {
93 }
94 
95 static void
96 adhoc_vdetach(struct ieee80211vap *vap)
97 {
98 }
99 
100 static void
101 adhoc_vattach(struct ieee80211vap *vap)
102 {
103 	vap->iv_newstate = adhoc_newstate;
104 	vap->iv_input = adhoc_input;
105 	if (vap->iv_opmode == IEEE80211_M_IBSS)
106 		vap->iv_recv_mgmt = adhoc_recv_mgmt;
107 	else
108 		vap->iv_recv_mgmt = ahdemo_recv_mgmt;
109 	vap->iv_recv_ctl = adhoc_recv_ctl;
110 	vap->iv_opdetach = adhoc_vdetach;
111 #ifdef IEEE80211_SUPPORT_TDMA
112 	/*
113 	 * Throw control to tdma support.  Note we do this
114 	 * after setting up our callbacks so it can piggyback
115 	 * on top of us.
116 	 */
117 	if (vap->iv_caps & IEEE80211_C_TDMA)
118 		ieee80211_tdma_vattach(vap);
119 #endif
120 }
121 
122 static void
123 sta_leave(void *arg, struct ieee80211_node *ni)
124 {
125 	struct ieee80211vap *vap = ni->ni_vap;
126 
127 	if (ni != vap->iv_bss)
128 		ieee80211_node_leave(ni);
129 }
130 
131 /*
132  * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
133  */
134 static int
135 adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
136 {
137 	struct ieee80211com *ic = vap->iv_ic;
138 	struct ieee80211_node *ni;
139 	enum ieee80211_state ostate;
140 
141 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
142 
143 	ostate = vap->iv_state;
144 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
145 	    __func__, ieee80211_state_name[ostate],
146 	    ieee80211_state_name[nstate], arg);
147 	vap->iv_state = nstate;			/* state transition */
148 	if (ostate != IEEE80211_S_SCAN)
149 		ieee80211_cancel_scan(vap);	/* background scan */
150 	ni = vap->iv_bss;			/* NB: no reference held */
151 	switch (nstate) {
152 	case IEEE80211_S_INIT:
153 		switch (ostate) {
154 		case IEEE80211_S_SCAN:
155 			ieee80211_cancel_scan(vap);
156 			break;
157 		default:
158 			break;
159 		}
160 		if (ostate != IEEE80211_S_INIT) {
161 			/* NB: optimize INIT -> INIT case */
162 			ieee80211_reset_bss(vap);
163 		}
164 		break;
165 	case IEEE80211_S_SCAN:
166 		switch (ostate) {
167 		case IEEE80211_S_RUN:		/* beacon miss */
168 			/* purge station table; entries are stale */
169 			ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
170 			    sta_leave, NULL);
171 			/* fall thru... */
172 		case IEEE80211_S_INIT:
173 			if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
174 			    !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
175 				/*
176 				 * Already have a channel; bypass the
177 				 * scan and startup immediately.
178 				 */
179 				ieee80211_create_ibss(vap,
180 				    ieee80211_ht_adjust_channel(ic,
181 				    vap->iv_des_chan, vap->iv_flags_ht));
182 				break;
183 			}
184 			/*
185 			 * Initiate a scan.  We can come here as a result
186 			 * of an IEEE80211_IOC_SCAN_REQ too in which case
187 			 * the vap will be marked with IEEE80211_FEXT_SCANREQ
188 			 * and the scan request parameters will be present
189 			 * in iv_scanreq.  Otherwise we do the default.
190 			 */
191 			if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
192 				ieee80211_check_scan(vap,
193 				    vap->iv_scanreq_flags,
194 				    vap->iv_scanreq_duration,
195 				    vap->iv_scanreq_mindwell,
196 				    vap->iv_scanreq_maxdwell,
197 				    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
198 				vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
199 			} else
200 				ieee80211_check_scan_current(vap);
201 			break;
202 		case IEEE80211_S_SCAN:
203 			/*
204 			 * This can happen because of a change in state
205 			 * that requires a reset.  Trigger a new scan
206 			 * unless we're in manual roaming mode in which
207 			 * case an application must issue an explicit request.
208 			 */
209 			if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
210 				ieee80211_check_scan_current(vap);
211 			break;
212 		default:
213 			goto invalid;
214 		}
215 		break;
216 	case IEEE80211_S_RUN:
217 		if (vap->iv_flags & IEEE80211_F_WPA) {
218 			/* XXX validate prerequisites */
219 		}
220 		switch (ostate) {
221 		case IEEE80211_S_INIT:
222 			/*
223 			 * Already have a channel; bypass the
224 			 * scan and startup immediately.
225 			 * Note that ieee80211_create_ibss will call
226 			 * back to do a RUN->RUN state change.
227 			 */
228 			ieee80211_create_ibss(vap,
229 			    ieee80211_ht_adjust_channel(ic,
230 				ic->ic_curchan, vap->iv_flags_ht));
231 			/* NB: iv_bss is changed on return */
232 			ni = vap->iv_bss;
233 			break;
234 		case IEEE80211_S_SCAN:
235 #ifdef IEEE80211_DEBUG
236 			if (ieee80211_msg_debug(vap)) {
237 				ieee80211_note(vap,
238 				    "synchronized with %s ssid ",
239 				    ether_sprintf(ni->ni_bssid));
240 				ieee80211_print_essid(vap->iv_bss->ni_essid,
241 				    ni->ni_esslen);
242 				/* XXX MCS/HT */
243 				printf(" channel %d start %uMb\n",
244 				    ieee80211_chan2ieee(ic, ic->ic_curchan),
245 				    IEEE80211_RATE2MBS(ni->ni_txrate));
246 			}
247 #endif
248 			break;
249 		case IEEE80211_S_RUN:	/* IBSS merge */
250 			break;
251 		default:
252 			goto invalid;
253 		}
254 		/*
255 		 * When 802.1x is not in use mark the port authorized
256 		 * at this point so traffic can flow.
257 		 */
258 		if (ni->ni_authmode != IEEE80211_AUTH_8021X)
259 			ieee80211_node_authorize(ni);
260 		/*
261 		 * Fake association when joining an existing bss.
262 		 */
263 		if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
264 		    ic->ic_newassoc != NULL)
265 			ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
266 		break;
267 	case IEEE80211_S_SLEEP:
268 		vap->iv_sta_ps(vap, 0);
269 		break;
270 	default:
271 	invalid:
272 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
273 		    "%s: unexpected state transition %s -> %s\n", __func__,
274 		    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
275 		break;
276 	}
277 	return 0;
278 }
279 
280 /*
281  * Decide if a received management frame should be
282  * printed when debugging is enabled.  This filters some
283  * of the less interesting frames that come frequently
284  * (e.g. beacons).
285  */
286 static __inline int
287 doprint(struct ieee80211vap *vap, int subtype)
288 {
289 	switch (subtype) {
290 	case IEEE80211_FC0_SUBTYPE_BEACON:
291 		return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
292 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
293 		return 1;
294 	}
295 	return 1;
296 }
297 
298 /*
299  * Process a received frame.  The node associated with the sender
300  * should be supplied.  If nothing was found in the node table then
301  * the caller is assumed to supply a reference to iv_bss instead.
302  * The RSSI and a timestamp are also supplied.  The RSSI data is used
303  * during AP scanning to select a AP to associate with; it can have
304  * any units so long as values have consistent units and higher values
305  * mean ``better signal''.  The receive timestamp is currently not used
306  * by the 802.11 layer.
307  */
308 static int
309 adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
310     const struct ieee80211_rx_stats *rxs, int rssi, int nf)
311 {
312 	struct ieee80211vap *vap = ni->ni_vap;
313 	struct ieee80211com *ic = ni->ni_ic;
314 	struct ifnet *ifp = vap->iv_ifp;
315 	struct ieee80211_frame *wh;
316 	struct ieee80211_key *key;
317 	struct ether_header *eh;
318 	int hdrspace, need_tap = 1;	/* mbuf need to be tapped. */
319 	uint8_t dir, type, subtype, qos;
320 	uint8_t *bssid;
321 	int is_hw_decrypted = 0;
322 	int has_decrypted = 0;
323 
324 	/*
325 	 * Some devices do hardware decryption all the way through
326 	 * to pretending the frame wasn't encrypted in the first place.
327 	 * So, tag it appropriately so it isn't discarded inappropriately.
328 	 */
329 	if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_DECRYPTED))
330 		is_hw_decrypted = 1;
331 
332 	if (m->m_flags & M_AMPDU_MPDU) {
333 		/*
334 		 * Fastpath for A-MPDU reorder q resubmission.  Frames
335 		 * w/ M_AMPDU_MPDU marked have already passed through
336 		 * here but were received out of order and been held on
337 		 * the reorder queue.  When resubmitted they are marked
338 		 * with the M_AMPDU_MPDU flag and we can bypass most of
339 		 * the normal processing.
340 		 */
341 		wh = mtod(m, struct ieee80211_frame *);
342 		type = IEEE80211_FC0_TYPE_DATA;
343 		dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
344 		subtype = IEEE80211_FC0_SUBTYPE_QOS;
345 		hdrspace = ieee80211_hdrspace(ic, wh);	/* XXX optimize? */
346 		goto resubmit_ampdu;
347 	}
348 
349 	KASSERT(ni != NULL, ("null node"));
350 	ni->ni_inact = ni->ni_inact_reload;
351 
352 	type = -1;			/* undefined */
353 
354 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
355 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
356 		    ni->ni_macaddr, NULL,
357 		    "too short (1): len %u", m->m_pkthdr.len);
358 		vap->iv_stats.is_rx_tooshort++;
359 		goto out;
360 	}
361 	/*
362 	 * Bit of a cheat here, we use a pointer for a 3-address
363 	 * frame format but don't reference fields past outside
364 	 * ieee80211_frame_min w/o first validating the data is
365 	 * present.
366 	 */
367 	wh = mtod(m, struct ieee80211_frame *);
368 
369 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
370 	    IEEE80211_FC0_VERSION_0) {
371 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
372 		    ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
373 		    wh->i_fc[0], wh->i_fc[1]);
374 		vap->iv_stats.is_rx_badversion++;
375 		goto err;
376 	}
377 
378 	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
379 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
380 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
381 	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
382 		if (dir != IEEE80211_FC1_DIR_NODS)
383 			bssid = wh->i_addr1;
384 		else if (type == IEEE80211_FC0_TYPE_CTL)
385 			bssid = wh->i_addr1;
386 		else {
387 			if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
388 				IEEE80211_DISCARD_MAC(vap,
389 				    IEEE80211_MSG_ANY, ni->ni_macaddr,
390 				    NULL, "too short (2): len %u",
391 				    m->m_pkthdr.len);
392 				vap->iv_stats.is_rx_tooshort++;
393 				goto out;
394 			}
395 			bssid = wh->i_addr3;
396 		}
397 		/*
398 		 * Validate the bssid.
399 		 */
400 		if (!(type == IEEE80211_FC0_TYPE_MGT &&
401 		     (subtype == IEEE80211_FC0_SUBTYPE_BEACON ||
402 		      subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP)) &&
403 		    !IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
404 		    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
405 			/* not interested in */
406 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
407 			    bssid, NULL, "%s", "not to bss");
408 			vap->iv_stats.is_rx_wrongbss++;
409 			goto out;
410 		}
411 		/*
412 		 * Data frame, cons up a node when it doesn't
413 		 * exist. This should probably done after an ACL check.
414 		 */
415 		if (type == IEEE80211_FC0_TYPE_DATA &&
416 		    ni == vap->iv_bss &&
417 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
418 			/*
419 			 * Beware of frames that come in too early; we
420 			 * can receive broadcast frames and creating sta
421 			 * entries will blow up because there is no bss
422 			 * channel yet.
423 			 */
424 			if (vap->iv_state != IEEE80211_S_RUN) {
425 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
426 				    wh, "data", "not in RUN state (%s)",
427 				    ieee80211_state_name[vap->iv_state]);
428 				vap->iv_stats.is_rx_badstate++;
429 				goto err;
430 			}
431 			/*
432 			 * Fake up a node for this newly discovered member
433 			 * of the IBSS.
434 			 *
435 			 * Note: This doesn't "upgrade" the node to 11n;
436 			 * that will happen after a probe request/response
437 			 * exchange.
438 			 */
439 			ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
440 			if (ni == NULL) {
441 				/* NB: stat kept for alloc failure */
442 				goto err;
443 			}
444 		}
445 		IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
446 		ni->ni_noise = nf;
447 		if (IEEE80211_HAS_SEQ(type, subtype) &&
448 		    IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
449 			uint8_t tid = ieee80211_gettid(wh);
450 			if (IEEE80211_QOS_HAS_SEQ(wh) &&
451 			    TID_TO_WME_AC(tid) >= WME_AC_VI)
452 				ic->ic_wme.wme_hipri_traffic++;
453 			if (! ieee80211_check_rxseq(ni, wh, bssid, rxs))
454 				goto out;
455 		}
456 	}
457 
458 	switch (type) {
459 	case IEEE80211_FC0_TYPE_DATA:
460 		hdrspace = ieee80211_hdrspace(ic, wh);
461 		if (m->m_len < hdrspace &&
462 		    (m = m_pullup(m, hdrspace)) == NULL) {
463 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
464 			    ni->ni_macaddr, NULL,
465 			    "data too short: expecting %u", hdrspace);
466 			vap->iv_stats.is_rx_tooshort++;
467 			goto out;		/* XXX */
468 		}
469 		if (dir != IEEE80211_FC1_DIR_NODS) {
470 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
471 			    wh, "data", "incorrect dir 0x%x", dir);
472 			vap->iv_stats.is_rx_wrongdir++;
473 			goto out;
474 		}
475 		/* XXX no power-save support */
476 
477 		/*
478 		 * Handle A-MPDU re-ordering.  If the frame is to be
479 		 * processed directly then ieee80211_ampdu_reorder
480 		 * will return 0; otherwise it has consumed the mbuf
481 		 * and we should do nothing more with it.
482 		 */
483 		if ((m->m_flags & M_AMPDU) &&
484 		    ieee80211_ampdu_reorder(ni, m, rxs) != 0) {
485 			m = NULL;
486 			goto out;
487 		}
488 	resubmit_ampdu:
489 
490 		/*
491 		 * Handle privacy requirements.  Note that we
492 		 * must not be preempted from here until after
493 		 * we (potentially) call ieee80211_crypto_demic;
494 		 * otherwise we may violate assumptions in the
495 		 * crypto cipher modules used to do delayed update
496 		 * of replay sequence numbers.
497 		 */
498 		if (is_hw_decrypted || IEEE80211_IS_PROTECTED(wh)) {
499 			if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
500 				/*
501 				 * Discard encrypted frames when privacy is off.
502 				 */
503 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
504 				    wh, "WEP", "%s", "PRIVACY off");
505 				vap->iv_stats.is_rx_noprivacy++;
506 				IEEE80211_NODE_STAT(ni, rx_noprivacy);
507 				goto out;
508 			}
509 			if (ieee80211_crypto_decap(ni, m, hdrspace, &key) == 0) {
510 				/* NB: stats+msgs handled in crypto_decap */
511 				IEEE80211_NODE_STAT(ni, rx_wepfail);
512 				goto out;
513 			}
514 			wh = mtod(m, struct ieee80211_frame *);
515 			wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
516 			has_decrypted = 1;
517 		} else {
518 			/* XXX M_WEP and IEEE80211_F_PRIVACY */
519 			key = NULL;
520 		}
521 
522 		/*
523 		 * Save QoS bits for use below--before we strip the header.
524 		 */
525 		if (subtype == IEEE80211_FC0_SUBTYPE_QOS)
526 			qos = ieee80211_getqos(wh)[0];
527 		else
528 			qos = 0;
529 
530 		/*
531 		 * Next up, any fragmentation.
532 		 */
533 		if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
534 			m = ieee80211_defrag(ni, m, hdrspace, has_decrypted);
535 			if (m == NULL) {
536 				/* Fragment dropped or frame not complete yet */
537 				goto out;
538 			}
539 		}
540 		wh = NULL;		/* no longer valid, catch any uses */
541 
542 		/*
543 		 * Next strip any MSDU crypto bits.
544 		 */
545 		if (!ieee80211_crypto_demic(vap, key, m, 0)) {
546 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
547 			    ni->ni_macaddr, "data", "%s", "demic error");
548 			vap->iv_stats.is_rx_demicfail++;
549 			IEEE80211_NODE_STAT(ni, rx_demicfail);
550 			goto out;
551 		}
552 
553 		/* copy to listener after decrypt */
554 		if (ieee80211_radiotap_active_vap(vap))
555 			ieee80211_radiotap_rx(vap, m);
556 		need_tap = 0;
557 
558 		/*
559 		 * Finally, strip the 802.11 header.
560 		 */
561 		m = ieee80211_decap(vap, m, hdrspace, qos);
562 		if (m == NULL) {
563 			/* XXX mask bit to check for both */
564 			/* don't count Null data frames as errors */
565 			if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
566 			    subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
567 				goto out;
568 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
569 			    ni->ni_macaddr, "data", "%s", "decap error");
570 			vap->iv_stats.is_rx_decap++;
571 			IEEE80211_NODE_STAT(ni, rx_decap);
572 			goto err;
573 		}
574 		if (!(qos & IEEE80211_QOS_AMSDU))
575 			eh = mtod(m, struct ether_header *);
576 		else
577 			eh = NULL;
578 		if (!ieee80211_node_is_authorized(ni)) {
579 			/*
580 			 * Deny any non-PAE frames received prior to
581 			 * authorization.  For open/shared-key
582 			 * authentication the port is mark authorized
583 			 * after authentication completes.  For 802.1x
584 			 * the port is not marked authorized by the
585 			 * authenticator until the handshake has completed.
586 			 */
587 			if (eh == NULL ||
588 			    eh->ether_type != htons(ETHERTYPE_PAE)) {
589 				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
590 				    ni->ni_macaddr, "data", "unauthorized or "
591 				    "unknown port: ether type 0x%x len %u",
592 				    eh == NULL ? -1 : eh->ether_type,
593 				    m->m_pkthdr.len);
594 				vap->iv_stats.is_rx_unauth++;
595 				IEEE80211_NODE_STAT(ni, rx_unauth);
596 				goto err;
597 			}
598 		} else {
599 			/*
600 			 * When denying unencrypted frames, discard
601 			 * any non-PAE frames received without encryption.
602 			 */
603 			if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
604 			    ((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
605 			    (is_hw_decrypted == 0) &&
606 			    (eh == NULL ||
607 			     eh->ether_type != htons(ETHERTYPE_PAE))) {
608 				/*
609 				 * Drop unencrypted frames.
610 				 */
611 				vap->iv_stats.is_rx_unencrypted++;
612 				IEEE80211_NODE_STAT(ni, rx_unencrypted);
613 				goto out;
614 			}
615 		}
616 		/* XXX require HT? */
617 		if (qos & IEEE80211_QOS_AMSDU) {
618 			m = ieee80211_decap_amsdu(ni, m);
619 			if (m == NULL)
620 				return IEEE80211_FC0_TYPE_DATA;
621 		} else {
622 #ifdef IEEE80211_SUPPORT_SUPERG
623 			m = ieee80211_decap_fastframe(vap, ni, m);
624 			if (m == NULL)
625 				return IEEE80211_FC0_TYPE_DATA;
626 #endif
627 		}
628 		if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
629 			ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
630 		else
631 			ieee80211_deliver_data(vap, ni, m);
632 		return IEEE80211_FC0_TYPE_DATA;
633 
634 	case IEEE80211_FC0_TYPE_MGT:
635 		vap->iv_stats.is_rx_mgmt++;
636 		IEEE80211_NODE_STAT(ni, rx_mgmt);
637 		if (dir != IEEE80211_FC1_DIR_NODS) {
638 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
639 			    wh, "data", "incorrect dir 0x%x", dir);
640 			vap->iv_stats.is_rx_wrongdir++;
641 			goto err;
642 		}
643 		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
644 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
645 			    ni->ni_macaddr, "mgt", "too short: len %u",
646 			    m->m_pkthdr.len);
647 			vap->iv_stats.is_rx_tooshort++;
648 			goto out;
649 		}
650 #ifdef IEEE80211_DEBUG
651 		if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
652 		    ieee80211_msg_dumppkts(vap)) {
653 			if_printf(ifp, "received %s from %s rssi %d\n",
654 			    ieee80211_mgt_subtype_name(subtype),
655 			    ether_sprintf(wh->i_addr2), rssi);
656 		}
657 #endif
658 		if (IEEE80211_IS_PROTECTED(wh)) {
659 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
660 			    wh, NULL, "%s", "WEP set but not permitted");
661 			vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
662 			goto out;
663 		}
664 		vap->iv_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
665 		goto out;
666 
667 	case IEEE80211_FC0_TYPE_CTL:
668 		vap->iv_stats.is_rx_ctl++;
669 		IEEE80211_NODE_STAT(ni, rx_ctrl);
670 		vap->iv_recv_ctl(ni, m, subtype);
671 		goto out;
672 
673 	default:
674 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
675 		    wh, "bad", "frame type 0x%x", type);
676 		/* should not come here */
677 		break;
678 	}
679 err:
680 	if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
681 out:
682 	if (m != NULL) {
683 		if (need_tap && ieee80211_radiotap_active_vap(vap))
684 			ieee80211_radiotap_rx(vap, m);
685 		m_freem(m);
686 	}
687 	return type;
688 }
689 
690 static int
691 is11bclient(const uint8_t *rates, const uint8_t *xrates)
692 {
693 	static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
694 	int i;
695 
696 	/* NB: the 11b clients we care about will not have xrates */
697 	if (xrates != NULL || rates == NULL)
698 		return 0;
699 	for (i = 0; i < rates[1]; i++) {
700 		int r = rates[2+i] & IEEE80211_RATE_VAL;
701 		if (r > 2*11 || ((1<<r) & brates) == 0)
702 			return 0;
703 	}
704 	return 1;
705 }
706 
707 static void
708 adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
709 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
710 {
711 	struct ieee80211vap *vap = ni->ni_vap;
712 	struct ieee80211com *ic = ni->ni_ic;
713 	struct ieee80211_channel *rxchan = ic->ic_curchan;
714 	struct ieee80211_frame *wh;
715 	uint8_t *frm, *efrm;
716 	uint8_t *ssid, *rates, *xrates;
717 #if 0
718 	int ht_state_change = 0;
719 #endif
720 
721 	wh = mtod(m0, struct ieee80211_frame *);
722 	frm = (uint8_t *)&wh[1];
723 	efrm = mtod(m0, uint8_t *) + m0->m_len;
724 
725 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
726 	    "%s: recv mgmt frame, addr2=%6D, ni=%p (%6D) fc=%.02x %.02x\n",
727 	    __func__,
728 	    wh->i_addr2, ":",
729 	    ni,
730 	    ni->ni_macaddr, ":",
731 	    wh->i_fc[0],
732 	    wh->i_fc[1]);
733 	switch (subtype) {
734 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
735 	case IEEE80211_FC0_SUBTYPE_BEACON: {
736 		struct ieee80211_scanparams scan;
737 		struct ieee80211_channel *c;
738 		/*
739 		 * We process beacon/probe response
740 		 * frames to discover neighbors.
741 		 */
742 		if (rxs != NULL) {
743 			c = ieee80211_lookup_channel_rxstatus(vap, rxs);
744 			if (c != NULL)
745 				rxchan = c;
746 		}
747 		if (ieee80211_parse_beacon(ni, m0, rxchan, &scan) != 0)
748 			return;
749 		/*
750 		 * Count frame now that we know it's to be processed.
751 		 */
752 		if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
753 			vap->iv_stats.is_rx_beacon++;		/* XXX remove */
754 			IEEE80211_NODE_STAT(ni, rx_beacons);
755 		} else
756 			IEEE80211_NODE_STAT(ni, rx_proberesp);
757 		/*
758 		 * If scanning, just pass information to the scan module.
759 		 */
760 		if (ic->ic_flags & IEEE80211_F_SCAN) {
761 			if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
762 				/*
763 				 * Actively scanning a channel marked passive;
764 				 * send a probe request now that we know there
765 				 * is 802.11 traffic present.
766 				 *
767 				 * XXX check if the beacon we recv'd gives
768 				 * us what we need and suppress the probe req
769 				 */
770 				ieee80211_probe_curchan(vap, 1);
771 				ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
772 			}
773 			ieee80211_add_scan(vap, rxchan, &scan, wh,
774 			    subtype, rssi, nf);
775 			return;
776 		}
777 		if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
778 			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
779 				/*
780 				 * Create a new entry in the neighbor table.
781 				 *
782 				 * XXX TODO:
783 				 *
784 				 * Here we're not scanning; so if we have an
785 				 * SSID then make sure it matches our SSID.
786 				 * Otherwise this code will match on all IBSS
787 				 * beacons/probe requests for all SSIDs,
788 				 * filling the node table with nodes that
789 				 * aren't ours.
790 				 */
791 				if (ieee80211_ibss_node_check_new(ni, &scan)) {
792 					ni = ieee80211_add_neighbor(vap, wh, &scan);
793 					/*
794 					 * Send a probe request so we announce 11n
795 					 * capabilities.
796 					 */
797 					ieee80211_send_probereq(ni, /* node */
798 					    vap->iv_myaddr, /* SA */
799 					    ni->ni_macaddr, /* DA */
800 					    vap->iv_bss->ni_bssid, /* BSSID */
801 					    vap->iv_bss->ni_essid,
802 					    vap->iv_bss->ni_esslen); /* SSID */
803 				} else
804 					ni = NULL;
805 
806 				/*
807 				 * Send a probe request so we announce 11n
808 				 * capabilities.
809 				 *
810 				 * Don't do this if we're scanning.
811 				 */
812 				if (! (ic->ic_flags & IEEE80211_F_SCAN))
813 					ieee80211_send_probereq(ni, /* node */
814 						vap->iv_myaddr, /* SA */
815 						ni->ni_macaddr, /* DA */
816 						vap->iv_bss->ni_bssid, /* BSSID */
817 						vap->iv_bss->ni_essid,
818 						vap->iv_bss->ni_esslen); /* SSID */
819 
820 			} else if (ni->ni_capinfo == 0) {
821 				/*
822 				 * Update faked node created on transmit.
823 				 * Note this also updates the tsf.
824 				 */
825 				ieee80211_init_neighbor(ni, wh, &scan);
826 
827 				/*
828 				 * Send a probe request so we announce 11n
829 				 * capabilities.
830 				 */
831 				ieee80211_send_probereq(ni, /* node */
832 					vap->iv_myaddr, /* SA */
833 					ni->ni_macaddr, /* DA */
834 					vap->iv_bss->ni_bssid, /* BSSID */
835 					vap->iv_bss->ni_essid,
836 					vap->iv_bss->ni_esslen); /* SSID */
837 			} else {
838 				/*
839 				 * Record tsf for potential resync.
840 				 */
841 				memcpy(ni->ni_tstamp.data, scan.tstamp,
842 					sizeof(ni->ni_tstamp));
843 			}
844 			/*
845 			 * This isn't enabled yet - otherwise it would
846 			 * update the HT parameters and channel width
847 			 * from any node, which could lead to lots of
848 			 * strange behaviour if the 11n nodes aren't
849 			 * exactly configured to match.
850 			 */
851 #if 0
852 			if (scan.htcap != NULL && scan.htinfo != NULL &&
853 			    (vap->iv_flags_ht & IEEE80211_FHT_HT)) {
854 				ieee80211_ht_updateparams(ni,
855 				    scan.htcap, scan.htinfo));
856 				if (ieee80211_ht_updateparams_final(ni,
857 				    scan.htcap, scan.htinfo))
858 					ht_state_change = 1;
859 			}
860 
861 			/* XXX same for VHT? */
862 #endif
863 			if (ni != NULL) {
864 				IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
865 				ni->ni_noise = nf;
866 			}
867 			/*
868 			 * Same here - the channel width change should
869 			 * be applied to the specific peer node, not
870 			 * to the ic.  Ie, the interface configuration
871 			 * should stay in its current channel width;
872 			 * but it should change the rate control and
873 			 * any queued frames for the given node only.
874 			 *
875 			 * Since there's no (current) way to inform
876 			 * the driver that a channel width change has
877 			 * occurred for a single node, just stub this
878 			 * out.
879 			 */
880 #if 0
881 			if (ht_state_change)
882 				ieee80211_update_chw(ic);
883 #endif
884 		}
885 		break;
886 	}
887 
888 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
889 		if (vap->iv_state != IEEE80211_S_RUN) {
890 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
891 			    wh, NULL, "wrong state %s",
892 			    ieee80211_state_name[vap->iv_state]);
893 			vap->iv_stats.is_rx_mgtdiscard++;
894 			return;
895 		}
896 		if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
897 			/* frame must be directed */
898 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
899 			    wh, NULL, "%s", "not unicast");
900 			vap->iv_stats.is_rx_mgtdiscard++;	/* XXX stat */
901 			return;
902 		}
903 
904 		/*
905 		 * prreq frame format
906 		 *	[tlv] ssid
907 		 *	[tlv] supported rates
908 		 *	[tlv] extended supported rates
909 		 */
910 		ssid = rates = xrates = NULL;
911 		while (efrm - frm > 1) {
912 			IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
913 			switch (*frm) {
914 			case IEEE80211_ELEMID_SSID:
915 				ssid = frm;
916 				break;
917 			case IEEE80211_ELEMID_RATES:
918 				rates = frm;
919 				break;
920 			case IEEE80211_ELEMID_XRATES:
921 				xrates = frm;
922 				break;
923 			}
924 			frm += frm[1] + 2;
925 		}
926 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
927 		if (xrates != NULL)
928 			IEEE80211_VERIFY_ELEMENT(xrates,
929 				IEEE80211_RATE_MAXSIZE - rates[1], return);
930 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
931 		IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
932 		if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
933 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
934 			    wh, NULL,
935 			    "%s", "no ssid with ssid suppression enabled");
936 			vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
937 			return;
938 		}
939 
940 		/* XXX find a better class or define it's own */
941 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
942 		    "%s", "recv probe req");
943 		/*
944 		 * Some legacy 11b clients cannot hack a complete
945 		 * probe response frame.  When the request includes
946 		 * only a bare-bones rate set, communicate this to
947 		 * the transmit side.
948 		 */
949 		ieee80211_send_proberesp(vap, wh->i_addr2,
950 		    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
951 
952 		/*
953 		 * Note: we don't benefit from stashing the probe request
954 		 * IEs away to use for IBSS negotiation, because we
955 		 * typically don't get all of the IEs.
956 		 */
957 		break;
958 
959 	case IEEE80211_FC0_SUBTYPE_ACTION:
960 	case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
961 		if ((ni == vap->iv_bss) &&
962 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
963 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
964 			    wh, NULL, "%s", "unknown node");
965 			vap->iv_stats.is_rx_mgtdiscard++;
966 		} else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
967 		    !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
968 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
969 			    wh, NULL, "%s", "not for us");
970 			vap->iv_stats.is_rx_mgtdiscard++;
971 		} else if (vap->iv_state != IEEE80211_S_RUN) {
972 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
973 			    wh, NULL, "wrong state %s",
974 			    ieee80211_state_name[vap->iv_state]);
975 			vap->iv_stats.is_rx_mgtdiscard++;
976 		} else {
977 			if (ieee80211_parse_action(ni, m0) == 0)
978 				(void)ic->ic_recv_action(ni, wh, frm, efrm);
979 		}
980 		break;
981 
982 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
983 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
984 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
985 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
986 	case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
987 	case IEEE80211_FC0_SUBTYPE_ATIM:
988 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
989 	case IEEE80211_FC0_SUBTYPE_AUTH:
990 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
991 		IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
992 		    wh, NULL, "%s", "not handled");
993 		vap->iv_stats.is_rx_mgtdiscard++;
994 		break;
995 
996 	default:
997 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
998 		    wh, "mgt", "subtype 0x%x not handled", subtype);
999 		vap->iv_stats.is_rx_badsubtype++;
1000 		break;
1001 	}
1002 }
1003 #undef IEEE80211_VERIFY_LENGTH
1004 #undef IEEE80211_VERIFY_ELEMENT
1005 
1006 static void
1007 ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
1008 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
1009 {
1010 	struct ieee80211vap *vap = ni->ni_vap;
1011 	struct ieee80211com *ic = ni->ni_ic;
1012 
1013 	/*
1014 	 * Process management frames when scanning; useful for doing
1015 	 * a site-survey.
1016 	 */
1017 	if (ic->ic_flags & IEEE80211_F_SCAN)
1018 		adhoc_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
1019 	else {
1020 #ifdef IEEE80211_DEBUG
1021 		struct ieee80211_frame *wh;
1022 
1023 		wh = mtod(m0, struct ieee80211_frame *);
1024 #endif
1025 		switch (subtype) {
1026 		case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1027 		case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1028 		case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1029 		case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1030 		case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
1031 		case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1032 		case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
1033 		case IEEE80211_FC0_SUBTYPE_BEACON:
1034 		case IEEE80211_FC0_SUBTYPE_ATIM:
1035 		case IEEE80211_FC0_SUBTYPE_DISASSOC:
1036 		case IEEE80211_FC0_SUBTYPE_AUTH:
1037 		case IEEE80211_FC0_SUBTYPE_DEAUTH:
1038 		case IEEE80211_FC0_SUBTYPE_ACTION:
1039 		case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
1040 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
1041 			     wh, NULL, "%s", "not handled");
1042 			vap->iv_stats.is_rx_mgtdiscard++;
1043 			break;
1044 		default:
1045 			IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
1046 			     wh, "mgt", "subtype 0x%x not handled", subtype);
1047 			vap->iv_stats.is_rx_badsubtype++;
1048 			break;
1049 		}
1050 	}
1051 }
1052 
1053 static void
1054 adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
1055 {
1056 
1057 	switch (subtype) {
1058 	case IEEE80211_FC0_SUBTYPE_BAR:
1059 		ieee80211_recv_bar(ni, m);
1060 		break;
1061 	}
1062 }
1063