xref: /freebsd/sys/net80211/ieee80211_adhoc.c (revision 7a7741af18d6c8a804cc643cb7ecda9d730c6aa6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 /*
29  * IEEE 802.11 IBSS mode support.
30  */
31 #include "opt_inet.h"
32 #include "opt_wlan.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/mbuf.h>
37 #include <sys/malloc.h>
38 #include <sys/kernel.h>
39 
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/endian.h>
43 #include <sys/errno.h>
44 #include <sys/proc.h>
45 #include <sys/sysctl.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/if_media.h>
50 #include <net/if_llc.h>
51 #include <net/if_private.h>
52 #include <net/ethernet.h>
53 
54 #include <net/bpf.h>
55 
56 #include <net80211/ieee80211_var.h>
57 #include <net80211/ieee80211_adhoc.h>
58 #include <net80211/ieee80211_input.h>
59 #ifdef IEEE80211_SUPPORT_SUPERG
60 #include <net80211/ieee80211_superg.h>
61 #endif
62 #ifdef IEEE80211_SUPPORT_TDMA
63 #include <net80211/ieee80211_tdma.h>
64 #endif
65 #include <net80211/ieee80211_sta.h>
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 *,
72 	    const struct ieee80211_rx_stats *, int, int);
73 static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
74 	int subtype, const struct ieee80211_rx_stats *, int, int);
75 static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
76 	    int subtype, const struct ieee80211_rx_stats *rxs, int, int);
77 static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
78 
79 void
80 ieee80211_adhoc_attach(struct ieee80211com *ic)
81 {
82 	ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
83 	ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
84 }
85 
86 void
87 ieee80211_adhoc_detach(struct ieee80211com *ic)
88 {
89 }
90 
91 static void
92 adhoc_vdetach(struct ieee80211vap *vap)
93 {
94 }
95 
96 static void
97 adhoc_vattach(struct ieee80211vap *vap)
98 {
99 	vap->iv_newstate = adhoc_newstate;
100 	vap->iv_input = adhoc_input;
101 	if (vap->iv_opmode == IEEE80211_M_IBSS)
102 		vap->iv_recv_mgmt = adhoc_recv_mgmt;
103 	else
104 		vap->iv_recv_mgmt = ahdemo_recv_mgmt;
105 	vap->iv_recv_ctl = adhoc_recv_ctl;
106 	vap->iv_opdetach = adhoc_vdetach;
107 #ifdef IEEE80211_SUPPORT_TDMA
108 	/*
109 	 * Throw control to tdma support.  Note we do this
110 	 * after setting up our callbacks so it can piggyback
111 	 * on top of us.
112 	 */
113 	if (vap->iv_caps & IEEE80211_C_TDMA)
114 		ieee80211_tdma_vattach(vap);
115 #endif
116 }
117 
118 static void
119 sta_leave(void *arg, struct ieee80211_node *ni)
120 {
121 	struct ieee80211vap *vap = ni->ni_vap;
122 
123 	if (ni != vap->iv_bss)
124 		ieee80211_node_leave(ni);
125 }
126 
127 /*
128  * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
129  */
130 static int
131 adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
132 {
133 	struct ieee80211com *ic = vap->iv_ic;
134 	struct ieee80211_node *ni;
135 	enum ieee80211_state ostate;
136 
137 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
138 
139 	ostate = vap->iv_state;
140 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
141 	    __func__, ieee80211_state_name[ostate],
142 	    ieee80211_state_name[nstate], arg);
143 	vap->iv_state = nstate;			/* state transition */
144 	if (ostate != IEEE80211_S_SCAN)
145 		ieee80211_cancel_scan(vap);	/* background scan */
146 	ni = vap->iv_bss;			/* NB: no reference held */
147 	switch (nstate) {
148 	case IEEE80211_S_INIT:
149 		switch (ostate) {
150 		case IEEE80211_S_SCAN:
151 			ieee80211_cancel_scan(vap);
152 			break;
153 		default:
154 			break;
155 		}
156 		if (ostate != IEEE80211_S_INIT) {
157 			/* NB: optimize INIT -> INIT case */
158 			ieee80211_reset_bss(vap);
159 		}
160 		break;
161 	case IEEE80211_S_SCAN:
162 		switch (ostate) {
163 		case IEEE80211_S_RUN:		/* beacon miss */
164 			/* purge station table; entries are stale */
165 			ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
166 			    sta_leave, NULL);
167 			/* fall thru... */
168 		case IEEE80211_S_INIT:
169 			if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
170 			    !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
171 				/*
172 				 * Already have a channel; bypass the
173 				 * scan and startup immediately.
174 				 */
175 				ieee80211_create_ibss(vap,
176 				    ieee80211_ht_adjust_channel(ic,
177 				    vap->iv_des_chan, vap->iv_flags_ht));
178 				break;
179 			}
180 			/*
181 			 * Initiate a scan.  We can come here as a result
182 			 * of an IEEE80211_IOC_SCAN_REQ too in which case
183 			 * the vap will be marked with IEEE80211_FEXT_SCANREQ
184 			 * and the scan request parameters will be present
185 			 * in iv_scanreq.  Otherwise we do the default.
186 			 */
187 			if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
188 				ieee80211_check_scan(vap,
189 				    vap->iv_scanreq_flags,
190 				    vap->iv_scanreq_duration,
191 				    vap->iv_scanreq_mindwell,
192 				    vap->iv_scanreq_maxdwell,
193 				    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
194 				vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
195 			} else
196 				ieee80211_check_scan_current(vap);
197 			break;
198 		case IEEE80211_S_SCAN:
199 			/*
200 			 * This can happen because of a change in state
201 			 * that requires a reset.  Trigger a new scan
202 			 * unless we're in manual roaming mode in which
203 			 * case an application must issue an explicit request.
204 			 */
205 			if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
206 				ieee80211_check_scan_current(vap);
207 			break;
208 		default:
209 			goto invalid;
210 		}
211 		break;
212 	case IEEE80211_S_RUN:
213 		if (vap->iv_flags & IEEE80211_F_WPA) {
214 			/* XXX validate prerequisites */
215 		}
216 		switch (ostate) {
217 		case IEEE80211_S_INIT:
218 			/*
219 			 * Already have a channel; bypass the
220 			 * scan and startup immediately.
221 			 * Note that ieee80211_create_ibss will call
222 			 * back to do a RUN->RUN state change.
223 			 */
224 			ieee80211_create_ibss(vap,
225 			    ieee80211_ht_adjust_channel(ic,
226 				ic->ic_curchan, vap->iv_flags_ht));
227 			/* NB: iv_bss is changed on return */
228 			ni = vap->iv_bss;
229 			break;
230 		case IEEE80211_S_SCAN:
231 #ifdef IEEE80211_DEBUG
232 			if (ieee80211_msg_debug(vap)) {
233 				ieee80211_note(vap,
234 				    "synchronized with %s ssid ",
235 				    ether_sprintf(ni->ni_bssid));
236 				ieee80211_print_essid(vap->iv_bss->ni_essid,
237 				    ni->ni_esslen);
238 				/* XXX MCS/HT */
239 				printf(" channel %d start %uMb\n",
240 				    ieee80211_chan2ieee(ic, ic->ic_curchan),
241 				    IEEE80211_RATE2MBS(ni->ni_txrate));
242 			}
243 #endif
244 			break;
245 		case IEEE80211_S_RUN:	/* IBSS merge */
246 			break;
247 		default:
248 			goto invalid;
249 		}
250 		/*
251 		 * When 802.1x is not in use mark the port authorized
252 		 * at this point so traffic can flow.
253 		 */
254 		if (ni->ni_authmode != IEEE80211_AUTH_8021X)
255 			ieee80211_node_authorize(ni);
256 		/*
257 		 * Fake association when joining an existing bss.
258 		 */
259 		if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
260 		    ic->ic_newassoc != NULL)
261 			ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
262 		break;
263 	case IEEE80211_S_SLEEP:
264 		vap->iv_sta_ps(vap, 0);
265 		break;
266 	default:
267 	invalid:
268 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
269 		    "%s: unexpected state transition %s -> %s\n", __func__,
270 		    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
271 		break;
272 	}
273 	return 0;
274 }
275 
276 /*
277  * Decide if a received management frame should be
278  * printed when debugging is enabled.  This filters some
279  * of the less interesting frames that come frequently
280  * (e.g. beacons).
281  */
282 static __inline int
283 doprint(struct ieee80211vap *vap, int subtype)
284 {
285 	switch (subtype) {
286 	case IEEE80211_FC0_SUBTYPE_BEACON:
287 		return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
288 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
289 		return 1;
290 	}
291 	return 1;
292 }
293 
294 /*
295  * Process a received frame.  The node associated with the sender
296  * should be supplied.  If nothing was found in the node table then
297  * the caller is assumed to supply a reference to iv_bss instead.
298  * The RSSI and a timestamp are also supplied.  The RSSI data is used
299  * during AP scanning to select a AP to associate with; it can have
300  * any units so long as values have consistent units and higher values
301  * mean ``better signal''.  The receive timestamp is currently not used
302  * by the 802.11 layer.
303  */
304 static int
305 adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
306     const struct ieee80211_rx_stats *rxs, int rssi, int nf)
307 {
308 	struct ieee80211vap *vap = ni->ni_vap;
309 	struct ieee80211com *ic = ni->ni_ic;
310 	struct ifnet *ifp = vap->iv_ifp;
311 	struct ieee80211_frame *wh;
312 	struct ieee80211_key *key;
313 	struct ether_header *eh;
314 	int hdrspace, need_tap = 1;	/* mbuf need to be tapped. */
315 	uint8_t dir, type, subtype, qos;
316 	uint8_t *bssid;
317 	int is_hw_decrypted = 0;
318 	int has_decrypted = 0;
319 
320 	/*
321 	 * Some devices do hardware decryption all the way through
322 	 * to pretending the frame wasn't encrypted in the first place.
323 	 * So, tag it appropriately so it isn't discarded inappropriately.
324 	 */
325 	if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_DECRYPTED))
326 		is_hw_decrypted = 1;
327 
328 	if (m->m_flags & M_AMPDU_MPDU) {
329 		/*
330 		 * Fastpath for A-MPDU reorder q resubmission.  Frames
331 		 * w/ M_AMPDU_MPDU marked have already passed through
332 		 * here but were received out of order and been held on
333 		 * the reorder queue.  When resubmitted they are marked
334 		 * with the M_AMPDU_MPDU flag and we can bypass most of
335 		 * the normal processing.
336 		 */
337 		wh = mtod(m, struct ieee80211_frame *);
338 		type = IEEE80211_FC0_TYPE_DATA;
339 		dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
340 		subtype = IEEE80211_FC0_SUBTYPE_QOS_DATA;
341 		hdrspace = ieee80211_hdrspace(ic, wh);	/* XXX optimize? */
342 		goto resubmit_ampdu;
343 	}
344 
345 	KASSERT(ni != NULL, ("null node"));
346 	ni->ni_inact = ni->ni_inact_reload;
347 
348 	type = -1;			/* undefined */
349 
350 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
351 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
352 		    ni->ni_macaddr, NULL,
353 		    "too short (1): len %u", m->m_pkthdr.len);
354 		vap->iv_stats.is_rx_tooshort++;
355 		goto out;
356 	}
357 	/*
358 	 * Bit of a cheat here, we use a pointer for a 3-address
359 	 * frame format but don't reference fields past outside
360 	 * ieee80211_frame_min w/o first validating the data is
361 	 * present.
362 	 */
363 	wh = mtod(m, struct ieee80211_frame *);
364 
365 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
366 	    IEEE80211_FC0_VERSION_0) {
367 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
368 		    ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
369 		    wh->i_fc[0], wh->i_fc[1]);
370 		vap->iv_stats.is_rx_badversion++;
371 		goto err;
372 	}
373 
374 	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
375 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
376 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
377 	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
378 		if (dir != IEEE80211_FC1_DIR_NODS)
379 			bssid = wh->i_addr1;
380 		else if (type == IEEE80211_FC0_TYPE_CTL)
381 			bssid = wh->i_addr1;
382 		else {
383 			if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
384 				IEEE80211_DISCARD_MAC(vap,
385 				    IEEE80211_MSG_ANY, ni->ni_macaddr,
386 				    NULL, "too short (2): len %u",
387 				    m->m_pkthdr.len);
388 				vap->iv_stats.is_rx_tooshort++;
389 				goto out;
390 			}
391 			bssid = wh->i_addr3;
392 		}
393 		/*
394 		 * Validate the bssid.
395 		 */
396 		if (!(type == IEEE80211_FC0_TYPE_MGT &&
397 		     (subtype == IEEE80211_FC0_SUBTYPE_BEACON ||
398 		      subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP)) &&
399 		    !IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
400 		    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
401 			/* not interested in */
402 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
403 			    bssid, NULL, "%s", "not to bss");
404 			vap->iv_stats.is_rx_wrongbss++;
405 			goto out;
406 		}
407 		/*
408 		 * Data frame, cons up a node when it doesn't
409 		 * exist. This should probably done after an ACL check.
410 		 */
411 		if (type == IEEE80211_FC0_TYPE_DATA &&
412 		    ni == vap->iv_bss &&
413 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
414 			/*
415 			 * Beware of frames that come in too early; we
416 			 * can receive broadcast frames and creating sta
417 			 * entries will blow up because there is no bss
418 			 * channel yet.
419 			 */
420 			if (vap->iv_state != IEEE80211_S_RUN) {
421 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
422 				    wh, "data", "not in RUN state (%s)",
423 				    ieee80211_state_name[vap->iv_state]);
424 				vap->iv_stats.is_rx_badstate++;
425 				goto err;
426 			}
427 			/*
428 			 * Fake up a node for this newly discovered member
429 			 * of the IBSS.
430 			 *
431 			 * Note: This doesn't "upgrade" the node to 11n;
432 			 * that will happen after a probe request/response
433 			 * exchange.
434 			 */
435 			ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
436 			if (ni == NULL) {
437 				/* NB: stat kept for alloc failure */
438 				goto err;
439 			}
440 		}
441 		IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
442 		ni->ni_noise = nf;
443 		if (IEEE80211_HAS_SEQ(type, subtype) &&
444 		    IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
445 			uint8_t tid = ieee80211_gettid(wh);
446 			if (IEEE80211_QOS_HAS_SEQ(wh) &&
447 			    TID_TO_WME_AC(tid) >= WME_AC_VI)
448 				ic->ic_wme.wme_hipri_traffic++;
449 			if (! ieee80211_check_rxseq(ni, wh, bssid, rxs))
450 				goto out;
451 		}
452 	}
453 
454 	switch (type) {
455 	case IEEE80211_FC0_TYPE_DATA:
456 		hdrspace = ieee80211_hdrspace(ic, wh);
457 		if (m->m_len < hdrspace &&
458 		    (m = m_pullup(m, hdrspace)) == NULL) {
459 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
460 			    ni->ni_macaddr, NULL,
461 			    "data too short: expecting %u", hdrspace);
462 			vap->iv_stats.is_rx_tooshort++;
463 			goto out;		/* XXX */
464 		}
465 		if (dir != IEEE80211_FC1_DIR_NODS) {
466 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
467 			    wh, "data", "incorrect dir 0x%x", dir);
468 			vap->iv_stats.is_rx_wrongdir++;
469 			goto out;
470 		}
471 		/* XXX no power-save support */
472 
473 		/*
474 		 * Handle A-MPDU re-ordering.  If the frame is to be
475 		 * processed directly then ieee80211_ampdu_reorder
476 		 * will return 0; otherwise it has consumed the mbuf
477 		 * and we should do nothing more with it.
478 		 */
479 		if ((m->m_flags & M_AMPDU) &&
480 		    ieee80211_ampdu_reorder(ni, m, rxs) != 0) {
481 			m = NULL;
482 			goto out;
483 		}
484 	resubmit_ampdu:
485 
486 		/*
487 		 * Handle privacy requirements.  Note that we
488 		 * must not be preempted from here until after
489 		 * we (potentially) call ieee80211_crypto_demic;
490 		 * otherwise we may violate assumptions in the
491 		 * crypto cipher modules used to do delayed update
492 		 * of replay sequence numbers.
493 		 */
494 		if (is_hw_decrypted || IEEE80211_IS_PROTECTED(wh)) {
495 			if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
496 				/*
497 				 * Discard encrypted frames when privacy is off.
498 				 */
499 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
500 				    wh, "WEP", "%s", "PRIVACY off");
501 				vap->iv_stats.is_rx_noprivacy++;
502 				IEEE80211_NODE_STAT(ni, rx_noprivacy);
503 				goto out;
504 			}
505 			if (ieee80211_crypto_decap(ni, m, hdrspace, &key) == 0) {
506 				/* NB: stats+msgs handled in crypto_decap */
507 				IEEE80211_NODE_STAT(ni, rx_wepfail);
508 				goto out;
509 			}
510 			wh = mtod(m, struct ieee80211_frame *);
511 			wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
512 			has_decrypted = 1;
513 		} else {
514 			/* XXX M_WEP and IEEE80211_F_PRIVACY */
515 			key = NULL;
516 		}
517 
518 		/*
519 		 * Save QoS bits for use below--before we strip the header.
520 		 */
521 		if (subtype == IEEE80211_FC0_SUBTYPE_QOS_DATA)
522 			qos = ieee80211_getqos(wh)[0];
523 		else
524 			qos = 0;
525 
526 		/*
527 		 * Next up, any fragmentation.
528 		 */
529 		if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
530 			m = ieee80211_defrag(ni, m, hdrspace, has_decrypted);
531 			if (m == NULL) {
532 				/* Fragment dropped or frame not complete yet */
533 				goto out;
534 			}
535 		}
536 		wh = NULL;		/* no longer valid, catch any uses */
537 
538 		/*
539 		 * Next strip any MSDU crypto bits.
540 		 */
541 		if (!ieee80211_crypto_demic(vap, key, m, 0)) {
542 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
543 			    ni->ni_macaddr, "data", "%s", "demic error");
544 			vap->iv_stats.is_rx_demicfail++;
545 			IEEE80211_NODE_STAT(ni, rx_demicfail);
546 			goto out;
547 		}
548 
549 		/* copy to listener after decrypt */
550 		if (ieee80211_radiotap_active_vap(vap))
551 			ieee80211_radiotap_rx(vap, m);
552 		need_tap = 0;
553 
554 		/*
555 		 * Finally, strip the 802.11 header.
556 		 */
557 		m = ieee80211_decap(vap, m, hdrspace, qos);
558 		if (m == NULL) {
559 			/* XXX mask bit to check for both */
560 			/* don't count Null data frames as errors */
561 			if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
562 			    subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
563 				goto out;
564 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
565 			    ni->ni_macaddr, "data", "%s", "decap error");
566 			vap->iv_stats.is_rx_decap++;
567 			IEEE80211_NODE_STAT(ni, rx_decap);
568 			goto err;
569 		}
570 		if (!(qos & IEEE80211_QOS_AMSDU))
571 			eh = mtod(m, struct ether_header *);
572 		else
573 			eh = NULL;
574 		if (!ieee80211_node_is_authorized(ni)) {
575 			/*
576 			 * Deny any non-PAE frames received prior to
577 			 * authorization.  For open/shared-key
578 			 * authentication the port is mark authorized
579 			 * after authentication completes.  For 802.1x
580 			 * the port is not marked authorized by the
581 			 * authenticator until the handshake has completed.
582 			 */
583 			if (eh == NULL ||
584 			    eh->ether_type != htons(ETHERTYPE_PAE)) {
585 				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
586 				    ni->ni_macaddr, "data", "unauthorized or "
587 				    "unknown port: ether type 0x%x len %u",
588 				    eh == NULL ? -1 : eh->ether_type,
589 				    m->m_pkthdr.len);
590 				vap->iv_stats.is_rx_unauth++;
591 				IEEE80211_NODE_STAT(ni, rx_unauth);
592 				goto err;
593 			}
594 		} else {
595 			/*
596 			 * When denying unencrypted frames, discard
597 			 * any non-PAE frames received without encryption.
598 			 */
599 			if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
600 			    ((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
601 			    (is_hw_decrypted == 0) &&
602 			    (eh == NULL ||
603 			     eh->ether_type != htons(ETHERTYPE_PAE))) {
604 				/*
605 				 * Drop unencrypted frames.
606 				 */
607 				vap->iv_stats.is_rx_unencrypted++;
608 				IEEE80211_NODE_STAT(ni, rx_unencrypted);
609 				goto out;
610 			}
611 		}
612 		/* XXX require HT? */
613 		if (qos & IEEE80211_QOS_AMSDU) {
614 			m = ieee80211_decap_amsdu(ni, m);
615 			if (m == NULL)
616 				return IEEE80211_FC0_TYPE_DATA;
617 		} else {
618 #ifdef IEEE80211_SUPPORT_SUPERG
619 			m = ieee80211_decap_fastframe(vap, ni, m);
620 			if (m == NULL)
621 				return IEEE80211_FC0_TYPE_DATA;
622 #endif
623 		}
624 		if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
625 			ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
626 		else
627 			ieee80211_deliver_data(vap, ni, m);
628 		return IEEE80211_FC0_TYPE_DATA;
629 
630 	case IEEE80211_FC0_TYPE_MGT:
631 		vap->iv_stats.is_rx_mgmt++;
632 		IEEE80211_NODE_STAT(ni, rx_mgmt);
633 		if (dir != IEEE80211_FC1_DIR_NODS) {
634 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
635 			    wh, "data", "incorrect dir 0x%x", dir);
636 			vap->iv_stats.is_rx_wrongdir++;
637 			goto err;
638 		}
639 		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
640 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
641 			    ni->ni_macaddr, "mgt", "too short: len %u",
642 			    m->m_pkthdr.len);
643 			vap->iv_stats.is_rx_tooshort++;
644 			goto out;
645 		}
646 #ifdef IEEE80211_DEBUG
647 		if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
648 		    ieee80211_msg_dumppkts(vap)) {
649 			if_printf(ifp, "received %s from %s rssi %d\n",
650 			    ieee80211_mgt_subtype_name(subtype),
651 			    ether_sprintf(wh->i_addr2), rssi);
652 		}
653 #endif
654 		if (IEEE80211_IS_PROTECTED(wh)) {
655 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
656 			    wh, NULL, "%s", "WEP set but not permitted");
657 			vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
658 			goto out;
659 		}
660 		vap->iv_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
661 		goto out;
662 
663 	case IEEE80211_FC0_TYPE_CTL:
664 		vap->iv_stats.is_rx_ctl++;
665 		IEEE80211_NODE_STAT(ni, rx_ctrl);
666 		vap->iv_recv_ctl(ni, m, subtype);
667 		goto out;
668 
669 	default:
670 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
671 		    wh, "bad", "frame type 0x%x", type);
672 		/* should not come here */
673 		break;
674 	}
675 err:
676 	if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
677 out:
678 	if (m != NULL) {
679 		if (need_tap && ieee80211_radiotap_active_vap(vap))
680 			ieee80211_radiotap_rx(vap, m);
681 		m_freem(m);
682 	}
683 	return type;
684 }
685 
686 static int
687 is11bclient(const uint8_t *rates, const uint8_t *xrates)
688 {
689 	static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
690 	int i;
691 
692 	/* NB: the 11b clients we care about will not have xrates */
693 	if (xrates != NULL || rates == NULL)
694 		return 0;
695 	for (i = 0; i < rates[1]; i++) {
696 		int r = rates[2+i] & IEEE80211_RATE_VAL;
697 		if (r > 2*11 || ((1<<r) & brates) == 0)
698 			return 0;
699 	}
700 	return 1;
701 }
702 
703 static void
704 adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
705 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
706 {
707 	struct ieee80211vap *vap = ni->ni_vap;
708 	struct ieee80211com *ic = ni->ni_ic;
709 	struct ieee80211_channel *rxchan = ic->ic_curchan;
710 	struct ieee80211_frame *wh;
711 	uint8_t *frm, *efrm;
712 	uint8_t *ssid, *rates, *xrates;
713 #if 0
714 	int ht_state_change = 0;
715 #endif
716 
717 	wh = mtod(m0, struct ieee80211_frame *);
718 	frm = (uint8_t *)&wh[1];
719 	efrm = mtod(m0, uint8_t *) + m0->m_len;
720 
721 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
722 	    "%s: recv mgmt frame, addr2=%6D, ni=%p (%6D) fc=%.02x %.02x\n",
723 	    __func__,
724 	    wh->i_addr2, ":",
725 	    ni,
726 	    ni->ni_macaddr, ":",
727 	    wh->i_fc[0],
728 	    wh->i_fc[1]);
729 	switch (subtype) {
730 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
731 	case IEEE80211_FC0_SUBTYPE_BEACON: {
732 		struct ieee80211_scanparams scan;
733 		struct ieee80211_channel *c;
734 		/*
735 		 * We process beacon/probe response
736 		 * frames to discover neighbors.
737 		 */
738 		if (rxs != NULL) {
739 			c = ieee80211_lookup_channel_rxstatus(vap, rxs);
740 			if (c != NULL)
741 				rxchan = c;
742 		}
743 		if (ieee80211_parse_beacon(ni, m0, rxchan, &scan) != 0)
744 			return;
745 		/*
746 		 * Count frame now that we know it's to be processed.
747 		 */
748 		if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
749 			vap->iv_stats.is_rx_beacon++;		/* XXX remove */
750 			IEEE80211_NODE_STAT(ni, rx_beacons);
751 		} else
752 			IEEE80211_NODE_STAT(ni, rx_proberesp);
753 		/*
754 		 * If scanning, just pass information to the scan module.
755 		 */
756 		if (ic->ic_flags & IEEE80211_F_SCAN) {
757 			if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
758 				/*
759 				 * Actively scanning a channel marked passive;
760 				 * send a probe request now that we know there
761 				 * is 802.11 traffic present.
762 				 *
763 				 * XXX check if the beacon we recv'd gives
764 				 * us what we need and suppress the probe req
765 				 */
766 				ieee80211_probe_curchan(vap, true);
767 				ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
768 			}
769 			ieee80211_add_scan(vap, rxchan, &scan, wh,
770 			    subtype, rssi, nf);
771 			return;
772 		}
773 		if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
774 			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
775 				/*
776 				 * Create a new entry in the neighbor table.
777 				 *
778 				 * XXX TODO:
779 				 *
780 				 * Here we're not scanning; so if we have an
781 				 * SSID then make sure it matches our SSID.
782 				 * Otherwise this code will match on all IBSS
783 				 * beacons/probe requests for all SSIDs,
784 				 * filling the node table with nodes that
785 				 * aren't ours.
786 				 */
787 				if (ieee80211_ibss_node_check_new(ni, &scan)) {
788 					ni = ieee80211_add_neighbor(vap, wh, &scan);
789 					/*
790 					 * Send a probe request so we announce 11n
791 					 * capabilities.
792 					 */
793 					ieee80211_send_probereq(ni, /* node */
794 					    vap->iv_myaddr, /* SA */
795 					    ni->ni_macaddr, /* DA */
796 					    vap->iv_bss->ni_bssid, /* BSSID */
797 					    vap->iv_bss->ni_essid,
798 					    vap->iv_bss->ni_esslen); /* SSID */
799 				} else
800 					ni = NULL;
801 
802 				/*
803 				 * Send a probe request so we announce 11n
804 				 * capabilities.
805 				 *
806 				 * Don't do this if we're scanning.
807 				 */
808 				if (! (ic->ic_flags & IEEE80211_F_SCAN))
809 					ieee80211_send_probereq(ni, /* node */
810 						vap->iv_myaddr, /* SA */
811 						ni->ni_macaddr, /* DA */
812 						vap->iv_bss->ni_bssid, /* BSSID */
813 						vap->iv_bss->ni_essid,
814 						vap->iv_bss->ni_esslen); /* SSID */
815 
816 			} else if (ni->ni_capinfo == 0) {
817 				/*
818 				 * Update faked node created on transmit.
819 				 * Note this also updates the tsf.
820 				 */
821 				ieee80211_init_neighbor(ni, wh, &scan);
822 
823 				/*
824 				 * Send a probe request so we announce 11n
825 				 * capabilities.
826 				 */
827 				ieee80211_send_probereq(ni, /* node */
828 					vap->iv_myaddr, /* SA */
829 					ni->ni_macaddr, /* DA */
830 					vap->iv_bss->ni_bssid, /* BSSID */
831 					vap->iv_bss->ni_essid,
832 					vap->iv_bss->ni_esslen); /* SSID */
833 			} else {
834 				/*
835 				 * Record tsf for potential resync.
836 				 */
837 				memcpy(ni->ni_tstamp.data, scan.tstamp,
838 					sizeof(ni->ni_tstamp));
839 			}
840 			/*
841 			 * This isn't enabled yet - otherwise it would
842 			 * update the HT parameters and channel width
843 			 * from any node, which could lead to lots of
844 			 * strange behaviour if the 11n nodes aren't
845 			 * exactly configured to match.
846 			 */
847 #if 0
848 			if (scan.htcap != NULL && scan.htinfo != NULL &&
849 			    (vap->iv_flags_ht & IEEE80211_FHT_HT)) {
850 				ieee80211_ht_updateparams(ni,
851 				    scan.htcap, scan.htinfo));
852 				if (ieee80211_ht_updateparams_final(ni,
853 				    scan.htcap, scan.htinfo))
854 					ht_state_change = 1;
855 			}
856 
857 			/* XXX same for VHT? */
858 #endif
859 			if (ni != NULL) {
860 				IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
861 				ni->ni_noise = nf;
862 			}
863 			/*
864 			 * Same here - the channel width change should
865 			 * be applied to the specific peer node, not
866 			 * to the ic.  Ie, the interface configuration
867 			 * should stay in its current channel width;
868 			 * but it should change the rate control and
869 			 * any queued frames for the given node only.
870 			 *
871 			 * Since there's no (current) way to inform
872 			 * the driver that a channel width change has
873 			 * occurred for a single node, just stub this
874 			 * out.
875 			 */
876 #if 0
877 			if (ht_state_change)
878 				ieee80211_update_chw(ic);
879 #endif
880 		}
881 		break;
882 	}
883 
884 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
885 		if (vap->iv_state != IEEE80211_S_RUN) {
886 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
887 			    wh, NULL, "wrong state %s",
888 			    ieee80211_state_name[vap->iv_state]);
889 			vap->iv_stats.is_rx_mgtdiscard++;
890 			return;
891 		}
892 		if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
893 			/* frame must be directed */
894 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
895 			    wh, NULL, "%s", "not unicast");
896 			vap->iv_stats.is_rx_mgtdiscard++;	/* XXX stat */
897 			return;
898 		}
899 
900 		/*
901 		 * prreq frame format
902 		 *	[tlv] ssid
903 		 *	[tlv] supported rates
904 		 *	[tlv] extended supported rates
905 		 */
906 		ssid = rates = xrates = NULL;
907 		while (efrm - frm > 1) {
908 			IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
909 			switch (*frm) {
910 			case IEEE80211_ELEMID_SSID:
911 				ssid = frm;
912 				break;
913 			case IEEE80211_ELEMID_RATES:
914 				rates = frm;
915 				break;
916 			case IEEE80211_ELEMID_XRATES:
917 				xrates = frm;
918 				break;
919 			}
920 			frm += frm[1] + 2;
921 		}
922 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
923 		if (xrates != NULL)
924 			IEEE80211_VERIFY_ELEMENT(xrates,
925 				IEEE80211_RATE_MAXSIZE - rates[1], return);
926 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
927 		IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
928 		if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
929 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
930 			    wh, NULL,
931 			    "%s", "no ssid with ssid suppression enabled");
932 			vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
933 			return;
934 		}
935 
936 		/* XXX find a better class or define it's own */
937 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
938 		    "%s", "recv probe req");
939 		/*
940 		 * Some legacy 11b clients cannot hack a complete
941 		 * probe response frame.  When the request includes
942 		 * only a bare-bones rate set, communicate this to
943 		 * the transmit side.
944 		 */
945 		ieee80211_send_proberesp(vap, wh->i_addr2,
946 		    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
947 
948 		/*
949 		 * Note: we don't benefit from stashing the probe request
950 		 * IEs away to use for IBSS negotiation, because we
951 		 * typically don't get all of the IEs.
952 		 */
953 		break;
954 
955 	case IEEE80211_FC0_SUBTYPE_ACTION:
956 	case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
957 		if ((ni == vap->iv_bss) &&
958 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
959 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
960 			    wh, NULL, "%s", "unknown node");
961 			vap->iv_stats.is_rx_mgtdiscard++;
962 		} else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
963 		    !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
964 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
965 			    wh, NULL, "%s", "not for us");
966 			vap->iv_stats.is_rx_mgtdiscard++;
967 		} else if (vap->iv_state != IEEE80211_S_RUN) {
968 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
969 			    wh, NULL, "wrong state %s",
970 			    ieee80211_state_name[vap->iv_state]);
971 			vap->iv_stats.is_rx_mgtdiscard++;
972 		} else {
973 			if (ieee80211_parse_action(ni, m0) == 0)
974 				(void)ic->ic_recv_action(ni, wh, frm, efrm);
975 		}
976 		break;
977 
978 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
979 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
980 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
981 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
982 	case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
983 	case IEEE80211_FC0_SUBTYPE_ATIM:
984 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
985 	case IEEE80211_FC0_SUBTYPE_AUTH:
986 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
987 		IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
988 		    wh, NULL, "%s", "not handled");
989 		vap->iv_stats.is_rx_mgtdiscard++;
990 		break;
991 
992 	default:
993 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
994 		    wh, "mgt", "subtype 0x%x not handled", subtype);
995 		vap->iv_stats.is_rx_badsubtype++;
996 		break;
997 	}
998 }
999 #undef IEEE80211_VERIFY_LENGTH
1000 #undef IEEE80211_VERIFY_ELEMENT
1001 
1002 static void
1003 ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
1004 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
1005 {
1006 	struct ieee80211vap *vap = ni->ni_vap;
1007 	struct ieee80211com *ic = ni->ni_ic;
1008 
1009 	/*
1010 	 * Process management frames when scanning; useful for doing
1011 	 * a site-survey.
1012 	 */
1013 	if (ic->ic_flags & IEEE80211_F_SCAN)
1014 		adhoc_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
1015 	else {
1016 #ifdef IEEE80211_DEBUG
1017 		struct ieee80211_frame *wh;
1018 
1019 		wh = mtod(m0, struct ieee80211_frame *);
1020 #endif
1021 		switch (subtype) {
1022 		case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1023 		case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1024 		case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1025 		case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1026 		case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
1027 		case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1028 		case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
1029 		case IEEE80211_FC0_SUBTYPE_BEACON:
1030 		case IEEE80211_FC0_SUBTYPE_ATIM:
1031 		case IEEE80211_FC0_SUBTYPE_DISASSOC:
1032 		case IEEE80211_FC0_SUBTYPE_AUTH:
1033 		case IEEE80211_FC0_SUBTYPE_DEAUTH:
1034 		case IEEE80211_FC0_SUBTYPE_ACTION:
1035 		case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
1036 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
1037 			     wh, NULL, "%s", "not handled");
1038 			vap->iv_stats.is_rx_mgtdiscard++;
1039 			break;
1040 		default:
1041 			IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
1042 			     wh, "mgt", "subtype 0x%x not handled", subtype);
1043 			vap->iv_stats.is_rx_badsubtype++;
1044 			break;
1045 		}
1046 	}
1047 }
1048 
1049 static void
1050 adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
1051 {
1052 
1053 	switch (subtype) {
1054 	case IEEE80211_FC0_SUBTYPE_BAR:
1055 		ieee80211_recv_bar(ni, m);
1056 		break;
1057 	}
1058 }
1059