xref: /freebsd/sys/net80211/ieee80211_adhoc.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
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_var.h>
52 #include <net/if_media.h>
53 #include <net/if_llc.h>
54 #include <net/ethernet.h>
55 
56 #include <net/bpf.h>
57 
58 #include <net80211/ieee80211_var.h>
59 #include <net80211/ieee80211_adhoc.h>
60 #include <net80211/ieee80211_input.h>
61 #ifdef IEEE80211_SUPPORT_SUPERG
62 #include <net80211/ieee80211_superg.h>
63 #endif
64 #ifdef IEEE80211_SUPPORT_TDMA
65 #include <net80211/ieee80211_tdma.h>
66 #endif
67 #include <net80211/ieee80211_sta.h>
68 
69 #define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
70 
71 static	void adhoc_vattach(struct ieee80211vap *);
72 static	int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
73 static int adhoc_input(struct ieee80211_node *, struct mbuf *,
74 	    const struct ieee80211_rx_stats *, int, int);
75 static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
76 	int subtype, const struct ieee80211_rx_stats *, int, int);
77 static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
78 	    int subtype, const struct ieee80211_rx_stats *rxs, int, int);
79 static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
80 
81 void
82 ieee80211_adhoc_attach(struct ieee80211com *ic)
83 {
84 	ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
85 	ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
86 }
87 
88 void
89 ieee80211_adhoc_detach(struct ieee80211com *ic)
90 {
91 }
92 
93 static void
94 adhoc_vdetach(struct ieee80211vap *vap)
95 {
96 }
97 
98 static void
99 adhoc_vattach(struct ieee80211vap *vap)
100 {
101 	vap->iv_newstate = adhoc_newstate;
102 	vap->iv_input = adhoc_input;
103 	if (vap->iv_opmode == IEEE80211_M_IBSS)
104 		vap->iv_recv_mgmt = adhoc_recv_mgmt;
105 	else
106 		vap->iv_recv_mgmt = ahdemo_recv_mgmt;
107 	vap->iv_recv_ctl = adhoc_recv_ctl;
108 	vap->iv_opdetach = adhoc_vdetach;
109 #ifdef IEEE80211_SUPPORT_TDMA
110 	/*
111 	 * Throw control to tdma support.  Note we do this
112 	 * after setting up our callbacks so it can piggyback
113 	 * on top of us.
114 	 */
115 	if (vap->iv_caps & IEEE80211_C_TDMA)
116 		ieee80211_tdma_vattach(vap);
117 #endif
118 }
119 
120 static void
121 sta_leave(void *arg, struct ieee80211_node *ni)
122 {
123 	struct ieee80211vap *vap = ni->ni_vap;
124 
125 	if (ni != vap->iv_bss)
126 		ieee80211_node_leave(ni);
127 }
128 
129 /*
130  * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
131  */
132 static int
133 adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
134 {
135 	struct ieee80211com *ic = vap->iv_ic;
136 	struct ieee80211_node *ni;
137 	enum ieee80211_state ostate;
138 
139 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
140 
141 	ostate = vap->iv_state;
142 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
143 	    __func__, ieee80211_state_name[ostate],
144 	    ieee80211_state_name[nstate], arg);
145 	vap->iv_state = nstate;			/* state transition */
146 	if (ostate != IEEE80211_S_SCAN)
147 		ieee80211_cancel_scan(vap);	/* background scan */
148 	ni = vap->iv_bss;			/* NB: no reference held */
149 	switch (nstate) {
150 	case IEEE80211_S_INIT:
151 		switch (ostate) {
152 		case IEEE80211_S_SCAN:
153 			ieee80211_cancel_scan(vap);
154 			break;
155 		default:
156 			break;
157 		}
158 		if (ostate != IEEE80211_S_INIT) {
159 			/* NB: optimize INIT -> INIT case */
160 			ieee80211_reset_bss(vap);
161 		}
162 		break;
163 	case IEEE80211_S_SCAN:
164 		switch (ostate) {
165 		case IEEE80211_S_RUN:		/* beacon miss */
166 			/* purge station table; entries are stale */
167 			ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
168 			    sta_leave, NULL);
169 			/* fall thru... */
170 		case IEEE80211_S_INIT:
171 			if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
172 			    !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
173 				/*
174 				 * Already have a channel; bypass the
175 				 * scan and startup immediately.
176 				 */
177 				ieee80211_create_ibss(vap,
178 				    ieee80211_ht_adjust_channel(ic,
179 				    vap->iv_des_chan, vap->iv_flags_ht));
180 				break;
181 			}
182 			/*
183 			 * Initiate a scan.  We can come here as a result
184 			 * of an IEEE80211_IOC_SCAN_REQ too in which case
185 			 * the vap will be marked with IEEE80211_FEXT_SCANREQ
186 			 * and the scan request parameters will be present
187 			 * in iv_scanreq.  Otherwise we do the default.
188 			 */
189 			if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
190 				ieee80211_check_scan(vap,
191 				    vap->iv_scanreq_flags,
192 				    vap->iv_scanreq_duration,
193 				    vap->iv_scanreq_mindwell,
194 				    vap->iv_scanreq_maxdwell,
195 				    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
196 				vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
197 			} else
198 				ieee80211_check_scan_current(vap);
199 			break;
200 		case IEEE80211_S_SCAN:
201 			/*
202 			 * This can happen because of a change in state
203 			 * that requires a reset.  Trigger a new scan
204 			 * unless we're in manual roaming mode in which
205 			 * case an application must issue an explicit request.
206 			 */
207 			if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
208 				ieee80211_check_scan_current(vap);
209 			break;
210 		default:
211 			goto invalid;
212 		}
213 		break;
214 	case IEEE80211_S_RUN:
215 		if (vap->iv_flags & IEEE80211_F_WPA) {
216 			/* XXX validate prerequisites */
217 		}
218 		switch (ostate) {
219 		case IEEE80211_S_INIT:
220 			/*
221 			 * Already have a channel; bypass the
222 			 * scan and startup immediately.
223 			 * Note that ieee80211_create_ibss will call
224 			 * back to do a RUN->RUN state change.
225 			 */
226 			ieee80211_create_ibss(vap,
227 			    ieee80211_ht_adjust_channel(ic,
228 				ic->ic_curchan, vap->iv_flags_ht));
229 			/* NB: iv_bss is changed on return */
230 			ni = vap->iv_bss;
231 			break;
232 		case IEEE80211_S_SCAN:
233 #ifdef IEEE80211_DEBUG
234 			if (ieee80211_msg_debug(vap)) {
235 				ieee80211_note(vap,
236 				    "synchronized with %s ssid ",
237 				    ether_sprintf(ni->ni_bssid));
238 				ieee80211_print_essid(vap->iv_bss->ni_essid,
239 				    ni->ni_esslen);
240 				/* XXX MCS/HT */
241 				printf(" channel %d start %uMb\n",
242 				    ieee80211_chan2ieee(ic, ic->ic_curchan),
243 				    IEEE80211_RATE2MBS(ni->ni_txrate));
244 			}
245 #endif
246 			break;
247 		case IEEE80211_S_RUN:	/* IBSS merge */
248 			break;
249 		default:
250 			goto invalid;
251 		}
252 		/*
253 		 * When 802.1x is not in use mark the port authorized
254 		 * at this point so traffic can flow.
255 		 */
256 		if (ni->ni_authmode != IEEE80211_AUTH_8021X)
257 			ieee80211_node_authorize(ni);
258 		/*
259 		 * Fake association when joining an existing bss.
260 		 */
261 		if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
262 		    ic->ic_newassoc != NULL)
263 			ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
264 		break;
265 	case IEEE80211_S_SLEEP:
266 		vap->iv_sta_ps(vap, 0);
267 		break;
268 	default:
269 	invalid:
270 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
271 		    "%s: unexpected state transition %s -> %s\n", __func__,
272 		    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
273 		break;
274 	}
275 	return 0;
276 }
277 
278 /*
279  * Decide if a received management frame should be
280  * printed when debugging is enabled.  This filters some
281  * of the less interesting frames that come frequently
282  * (e.g. beacons).
283  */
284 static __inline int
285 doprint(struct ieee80211vap *vap, int subtype)
286 {
287 	switch (subtype) {
288 	case IEEE80211_FC0_SUBTYPE_BEACON:
289 		return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
290 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
291 		return 1;
292 	}
293 	return 1;
294 }
295 
296 /*
297  * Process a received frame.  The node associated with the sender
298  * should be supplied.  If nothing was found in the node table then
299  * the caller is assumed to supply a reference to iv_bss instead.
300  * The RSSI and a timestamp are also supplied.  The RSSI data is used
301  * during AP scanning to select a AP to associate with; it can have
302  * any units so long as values have consistent units and higher values
303  * mean ``better signal''.  The receive timestamp is currently not used
304  * by the 802.11 layer.
305  */
306 static int
307 adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
308     const struct ieee80211_rx_stats *rxs, int rssi, int nf)
309 {
310 	struct ieee80211vap *vap = ni->ni_vap;
311 	struct ieee80211com *ic = ni->ni_ic;
312 	struct ifnet *ifp = vap->iv_ifp;
313 	struct ieee80211_frame *wh;
314 	struct ieee80211_key *key;
315 	struct ether_header *eh;
316 	int hdrspace, need_tap = 1;	/* mbuf need to be tapped. */
317 	uint8_t dir, type, subtype, qos;
318 	uint8_t *bssid;
319 	int is_hw_decrypted = 0;
320 	int has_decrypted = 0;
321 
322 	/*
323 	 * Some devices do hardware decryption all the way through
324 	 * to pretending the frame wasn't encrypted in the first place.
325 	 * So, tag it appropriately so it isn't discarded inappropriately.
326 	 */
327 	if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_DECRYPTED))
328 		is_hw_decrypted = 1;
329 
330 	if (m->m_flags & M_AMPDU_MPDU) {
331 		/*
332 		 * Fastpath for A-MPDU reorder q resubmission.  Frames
333 		 * w/ M_AMPDU_MPDU marked have already passed through
334 		 * here but were received out of order and been held on
335 		 * the reorder queue.  When resubmitted they are marked
336 		 * with the M_AMPDU_MPDU flag and we can bypass most of
337 		 * the normal processing.
338 		 */
339 		wh = mtod(m, struct ieee80211_frame *);
340 		type = IEEE80211_FC0_TYPE_DATA;
341 		dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
342 		subtype = IEEE80211_FC0_SUBTYPE_QOS;
343 		hdrspace = ieee80211_hdrspace(ic, wh);	/* XXX optimize? */
344 		goto resubmit_ampdu;
345 	}
346 
347 	KASSERT(ni != NULL, ("null node"));
348 	ni->ni_inact = ni->ni_inact_reload;
349 
350 	type = -1;			/* undefined */
351 
352 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
353 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
354 		    ni->ni_macaddr, NULL,
355 		    "too short (1): len %u", m->m_pkthdr.len);
356 		vap->iv_stats.is_rx_tooshort++;
357 		goto out;
358 	}
359 	/*
360 	 * Bit of a cheat here, we use a pointer for a 3-address
361 	 * frame format but don't reference fields past outside
362 	 * ieee80211_frame_min w/o first validating the data is
363 	 * present.
364 	 */
365 	wh = mtod(m, struct ieee80211_frame *);
366 
367 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
368 	    IEEE80211_FC0_VERSION_0) {
369 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
370 		    ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
371 		    wh->i_fc[0], wh->i_fc[1]);
372 		vap->iv_stats.is_rx_badversion++;
373 		goto err;
374 	}
375 
376 	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
377 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
378 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
379 	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
380 		if (dir != IEEE80211_FC1_DIR_NODS)
381 			bssid = wh->i_addr1;
382 		else if (type == IEEE80211_FC0_TYPE_CTL)
383 			bssid = wh->i_addr1;
384 		else {
385 			if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
386 				IEEE80211_DISCARD_MAC(vap,
387 				    IEEE80211_MSG_ANY, ni->ni_macaddr,
388 				    NULL, "too short (2): len %u",
389 				    m->m_pkthdr.len);
390 				vap->iv_stats.is_rx_tooshort++;
391 				goto out;
392 			}
393 			bssid = wh->i_addr3;
394 		}
395 		/*
396 		 * Validate the bssid.
397 		 */
398 		if (!(type == IEEE80211_FC0_TYPE_MGT &&
399 		     (subtype == IEEE80211_FC0_SUBTYPE_BEACON ||
400 		      subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP)) &&
401 		    !IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
402 		    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
403 			/* not interested in */
404 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
405 			    bssid, NULL, "%s", "not to bss");
406 			vap->iv_stats.is_rx_wrongbss++;
407 			goto out;
408 		}
409 		/*
410 		 * Data frame, cons up a node when it doesn't
411 		 * exist. This should probably done after an ACL check.
412 		 */
413 		if (type == IEEE80211_FC0_TYPE_DATA &&
414 		    ni == vap->iv_bss &&
415 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
416 			/*
417 			 * Beware of frames that come in too early; we
418 			 * can receive broadcast frames and creating sta
419 			 * entries will blow up because there is no bss
420 			 * channel yet.
421 			 */
422 			if (vap->iv_state != IEEE80211_S_RUN) {
423 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
424 				    wh, "data", "not in RUN state (%s)",
425 				    ieee80211_state_name[vap->iv_state]);
426 				vap->iv_stats.is_rx_badstate++;
427 				goto err;
428 			}
429 			/*
430 			 * Fake up a node for this newly discovered member
431 			 * of the IBSS.
432 			 *
433 			 * Note: This doesn't "upgrade" the node to 11n;
434 			 * that will happen after a probe request/response
435 			 * exchange.
436 			 */
437 			ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
438 			if (ni == NULL) {
439 				/* NB: stat kept for alloc failure */
440 				goto err;
441 			}
442 		}
443 		IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
444 		ni->ni_noise = nf;
445 		if (IEEE80211_HAS_SEQ(type, subtype) &&
446 		    IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
447 			uint8_t tid = ieee80211_gettid(wh);
448 			if (IEEE80211_QOS_HAS_SEQ(wh) &&
449 			    TID_TO_WME_AC(tid) >= WME_AC_VI)
450 				ic->ic_wme.wme_hipri_traffic++;
451 			if (! ieee80211_check_rxseq(ni, wh, bssid, rxs))
452 				goto out;
453 		}
454 	}
455 
456 	switch (type) {
457 	case IEEE80211_FC0_TYPE_DATA:
458 		hdrspace = ieee80211_hdrspace(ic, wh);
459 		if (m->m_len < hdrspace &&
460 		    (m = m_pullup(m, hdrspace)) == NULL) {
461 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
462 			    ni->ni_macaddr, NULL,
463 			    "data too short: expecting %u", hdrspace);
464 			vap->iv_stats.is_rx_tooshort++;
465 			goto out;		/* XXX */
466 		}
467 		if (dir != IEEE80211_FC1_DIR_NODS) {
468 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
469 			    wh, "data", "incorrect dir 0x%x", dir);
470 			vap->iv_stats.is_rx_wrongdir++;
471 			goto out;
472 		}
473 		/* XXX no power-save support */
474 
475 		/*
476 		 * Handle A-MPDU re-ordering.  If the frame is to be
477 		 * processed directly then ieee80211_ampdu_reorder
478 		 * will return 0; otherwise it has consumed the mbuf
479 		 * and we should do nothing more with it.
480 		 */
481 		if ((m->m_flags & M_AMPDU) &&
482 		    ieee80211_ampdu_reorder(ni, m, rxs) != 0) {
483 			m = NULL;
484 			goto out;
485 		}
486 	resubmit_ampdu:
487 
488 		/*
489 		 * Handle privacy requirements.  Note that we
490 		 * must not be preempted from here until after
491 		 * we (potentially) call ieee80211_crypto_demic;
492 		 * otherwise we may violate assumptions in the
493 		 * crypto cipher modules used to do delayed update
494 		 * of replay sequence numbers.
495 		 */
496 		if (is_hw_decrypted || wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
497 			if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
498 				/*
499 				 * Discard encrypted frames when privacy is off.
500 				 */
501 				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
502 				    wh, "WEP", "%s", "PRIVACY off");
503 				vap->iv_stats.is_rx_noprivacy++;
504 				IEEE80211_NODE_STAT(ni, rx_noprivacy);
505 				goto out;
506 			}
507 			if (ieee80211_crypto_decap(ni, m, hdrspace, &key) == 0) {
508 				/* NB: stats+msgs handled in crypto_decap */
509 				IEEE80211_NODE_STAT(ni, rx_wepfail);
510 				goto out;
511 			}
512 			wh = mtod(m, struct ieee80211_frame *);
513 			wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
514 			has_decrypted = 1;
515 		} else {
516 			/* XXX M_WEP and IEEE80211_F_PRIVACY */
517 			key = NULL;
518 		}
519 
520 		/*
521 		 * Save QoS bits for use below--before we strip the header.
522 		 */
523 		if (subtype == IEEE80211_FC0_SUBTYPE_QOS) {
524 			qos = (dir == IEEE80211_FC1_DIR_DSTODS) ?
525 			    ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0] :
526 			    ((struct ieee80211_qosframe *)wh)->i_qos[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);
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);
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 		eh = mtod(m, struct ether_header *);
575 		if (!ieee80211_node_is_authorized(ni)) {
576 			/*
577 			 * Deny any non-PAE frames received prior to
578 			 * authorization.  For open/shared-key
579 			 * authentication the port is mark authorized
580 			 * after authentication completes.  For 802.1x
581 			 * the port is not marked authorized by the
582 			 * authenticator until the handshake has completed.
583 			 */
584 			if (eh->ether_type != htons(ETHERTYPE_PAE)) {
585 				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
586 				    eh->ether_shost, "data",
587 				    "unauthorized port: ether type 0x%x len %u",
588 				    eh->ether_type, m->m_pkthdr.len);
589 				vap->iv_stats.is_rx_unauth++;
590 				IEEE80211_NODE_STAT(ni, rx_unauth);
591 				goto err;
592 			}
593 		} else {
594 			/*
595 			 * When denying unencrypted frames, discard
596 			 * any non-PAE frames received without encryption.
597 			 */
598 			if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
599 			    ((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
600 			    (is_hw_decrypted == 0) &&
601 			    eh->ether_type != htons(ETHERTYPE_PAE)) {
602 				/*
603 				 * Drop unencrypted frames.
604 				 */
605 				vap->iv_stats.is_rx_unencrypted++;
606 				IEEE80211_NODE_STAT(ni, rx_unencrypted);
607 				goto out;
608 			}
609 		}
610 		/* XXX require HT? */
611 		if (qos & IEEE80211_QOS_AMSDU) {
612 			m = ieee80211_decap_amsdu(ni, m);
613 			if (m == NULL)
614 				return IEEE80211_FC0_TYPE_DATA;
615 		} else {
616 #ifdef IEEE80211_SUPPORT_SUPERG
617 			m = ieee80211_decap_fastframe(vap, ni, m);
618 			if (m == NULL)
619 				return IEEE80211_FC0_TYPE_DATA;
620 #endif
621 		}
622 		if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
623 			ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
624 		else
625 			ieee80211_deliver_data(vap, ni, m);
626 		return IEEE80211_FC0_TYPE_DATA;
627 
628 	case IEEE80211_FC0_TYPE_MGT:
629 		vap->iv_stats.is_rx_mgmt++;
630 		IEEE80211_NODE_STAT(ni, rx_mgmt);
631 		if (dir != IEEE80211_FC1_DIR_NODS) {
632 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
633 			    wh, "data", "incorrect dir 0x%x", dir);
634 			vap->iv_stats.is_rx_wrongdir++;
635 			goto err;
636 		}
637 		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
638 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
639 			    ni->ni_macaddr, "mgt", "too short: len %u",
640 			    m->m_pkthdr.len);
641 			vap->iv_stats.is_rx_tooshort++;
642 			goto out;
643 		}
644 #ifdef IEEE80211_DEBUG
645 		if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
646 		    ieee80211_msg_dumppkts(vap)) {
647 			if_printf(ifp, "received %s from %s rssi %d\n",
648 			    ieee80211_mgt_subtype_name(subtype),
649 			    ether_sprintf(wh->i_addr2), rssi);
650 		}
651 #endif
652 		if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
653 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
654 			    wh, NULL, "%s", "WEP set but not permitted");
655 			vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
656 			goto out;
657 		}
658 		vap->iv_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
659 		goto out;
660 
661 	case IEEE80211_FC0_TYPE_CTL:
662 		vap->iv_stats.is_rx_ctl++;
663 		IEEE80211_NODE_STAT(ni, rx_ctrl);
664 		vap->iv_recv_ctl(ni, m, subtype);
665 		goto out;
666 
667 	default:
668 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
669 		    wh, "bad", "frame type 0x%x", type);
670 		/* should not come here */
671 		break;
672 	}
673 err:
674 	if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
675 out:
676 	if (m != NULL) {
677 		if (need_tap && ieee80211_radiotap_active_vap(vap))
678 			ieee80211_radiotap_rx(vap, m);
679 		m_freem(m);
680 	}
681 	return type;
682 }
683 
684 static int
685 is11bclient(const uint8_t *rates, const uint8_t *xrates)
686 {
687 	static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
688 	int i;
689 
690 	/* NB: the 11b clients we care about will not have xrates */
691 	if (xrates != NULL || rates == NULL)
692 		return 0;
693 	for (i = 0; i < rates[1]; i++) {
694 		int r = rates[2+i] & IEEE80211_RATE_VAL;
695 		if (r > 2*11 || ((1<<r) & brates) == 0)
696 			return 0;
697 	}
698 	return 1;
699 }
700 
701 static void
702 adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
703 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
704 {
705 	struct ieee80211vap *vap = ni->ni_vap;
706 	struct ieee80211com *ic = ni->ni_ic;
707 	struct ieee80211_channel *rxchan = ic->ic_curchan;
708 	struct ieee80211_frame *wh;
709 	uint8_t *frm, *efrm;
710 	uint8_t *ssid, *rates, *xrates;
711 #if 0
712 	int ht_state_change = 0;
713 #endif
714 
715 	wh = mtod(m0, struct ieee80211_frame *);
716 	frm = (uint8_t *)&wh[1];
717 	efrm = mtod(m0, uint8_t *) + m0->m_len;
718 	switch (subtype) {
719 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
720 	case IEEE80211_FC0_SUBTYPE_BEACON: {
721 		struct ieee80211_scanparams scan;
722 		struct ieee80211_channel *c;
723 		/*
724 		 * We process beacon/probe response
725 		 * frames to discover neighbors.
726 		 */
727 		if (rxs != NULL) {
728 			c = ieee80211_lookup_channel_rxstatus(vap, rxs);
729 			if (c != NULL)
730 				rxchan = c;
731 		}
732 		if (ieee80211_parse_beacon(ni, m0, rxchan, &scan) != 0)
733 			return;
734 		/*
735 		 * Count frame now that we know it's to be processed.
736 		 */
737 		if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
738 			vap->iv_stats.is_rx_beacon++;		/* XXX remove */
739 			IEEE80211_NODE_STAT(ni, rx_beacons);
740 		} else
741 			IEEE80211_NODE_STAT(ni, rx_proberesp);
742 		/*
743 		 * If scanning, just pass information to the scan module.
744 		 */
745 		if (ic->ic_flags & IEEE80211_F_SCAN) {
746 			if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
747 				/*
748 				 * Actively scanning a channel marked passive;
749 				 * send a probe request now that we know there
750 				 * is 802.11 traffic present.
751 				 *
752 				 * XXX check if the beacon we recv'd gives
753 				 * us what we need and suppress the probe req
754 				 */
755 				ieee80211_probe_curchan(vap, 1);
756 				ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
757 			}
758 			ieee80211_add_scan(vap, rxchan, &scan, wh,
759 			    subtype, rssi, nf);
760 			return;
761 		}
762 		if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
763 			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
764 				/*
765 				 * Create a new entry in the neighbor table.
766 				 *
767 				 * XXX TODO:
768 				 *
769 				 * Here we're not scanning; so if we have an
770 				 * SSID then make sure it matches our SSID.
771 				 * Otherwise this code will match on all IBSS
772 				 * beacons/probe requests for all SSIDs,
773 				 * filling the node table with nodes that
774 				 * aren't ours.
775 				 */
776 				if (ieee80211_ibss_node_check_new(ni, &scan)) {
777 					ni = ieee80211_add_neighbor(vap, wh, &scan);
778 					/*
779 					 * Send a probe request so we announce 11n
780 					 * capabilities.
781 					 */
782 					ieee80211_send_probereq(ni, /* node */
783 					    vap->iv_myaddr, /* SA */
784 					    ni->ni_macaddr, /* DA */
785 					    vap->iv_bss->ni_bssid, /* BSSID */
786 					    vap->iv_bss->ni_essid,
787 					    vap->iv_bss->ni_esslen); /* SSID */
788 				} else
789 					ni = NULL;
790 
791 			} else if (ni->ni_capinfo == 0) {
792 				/*
793 				 * Update faked node created on transmit.
794 				 * Note this also updates the tsf.
795 				 */
796 				ieee80211_init_neighbor(ni, wh, &scan);
797 
798 				/*
799 				 * Send a probe request so we announce 11n
800 				 * capabilities.
801 				 */
802 				ieee80211_send_probereq(ni, /* node */
803 					vap->iv_myaddr, /* SA */
804 					ni->ni_macaddr, /* DA */
805 					vap->iv_bss->ni_bssid, /* BSSID */
806 					vap->iv_bss->ni_essid,
807 					vap->iv_bss->ni_esslen); /* SSID */
808 			} else {
809 				/*
810 				 * Record tsf for potential resync.
811 				 */
812 				memcpy(ni->ni_tstamp.data, scan.tstamp,
813 					sizeof(ni->ni_tstamp));
814 			}
815 			/*
816 			 * This isn't enabled yet - otherwise it would
817 			 * update the HT parameters and channel width
818 			 * from any node, which could lead to lots of
819 			 * strange behaviour if the 11n nodes aren't
820 			 * exactly configured to match.
821 			 */
822 #if 0
823 			if (scan.htcap != NULL && scan.htinfo != NULL &&
824 			    (vap->iv_flags_ht & IEEE80211_FHT_HT)) {
825 				ieee80211_ht_updateparams(ni,
826 				    scan.htcap, scan.htinfo));
827 				if (ieee80211_ht_updateparams_final(ni,
828 				    scan.htcap, scan.htinfo))
829 					ht_state_change = 1;
830 			}
831 
832 			/* XXX same for VHT? */
833 #endif
834 			if (ni != NULL) {
835 				IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
836 				ni->ni_noise = nf;
837 			}
838 			/*
839 			 * Same here - the channel width change should
840 			 * be applied to the specific peer node, not
841 			 * to the ic.  Ie, the interface configuration
842 			 * should stay in its current channel width;
843 			 * but it should change the rate control and
844 			 * any queued frames for the given node only.
845 			 *
846 			 * Since there's no (current) way to inform
847 			 * the driver that a channel width change has
848 			 * occurred for a single node, just stub this
849 			 * out.
850 			 */
851 #if 0
852 			if (ht_state_change)
853 				ieee80211_update_chw(ic);
854 #endif
855 		}
856 		break;
857 	}
858 
859 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
860 		if (vap->iv_state != IEEE80211_S_RUN) {
861 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
862 			    wh, NULL, "wrong state %s",
863 			    ieee80211_state_name[vap->iv_state]);
864 			vap->iv_stats.is_rx_mgtdiscard++;
865 			return;
866 		}
867 		if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
868 			/* frame must be directed */
869 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
870 			    wh, NULL, "%s", "not unicast");
871 			vap->iv_stats.is_rx_mgtdiscard++;	/* XXX stat */
872 			return;
873 		}
874 
875 		/*
876 		 * prreq frame format
877 		 *	[tlv] ssid
878 		 *	[tlv] supported rates
879 		 *	[tlv] extended supported rates
880 		 */
881 		ssid = rates = xrates = NULL;
882 		while (efrm - frm > 1) {
883 			IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
884 			switch (*frm) {
885 			case IEEE80211_ELEMID_SSID:
886 				ssid = frm;
887 				break;
888 			case IEEE80211_ELEMID_RATES:
889 				rates = frm;
890 				break;
891 			case IEEE80211_ELEMID_XRATES:
892 				xrates = frm;
893 				break;
894 			}
895 			frm += frm[1] + 2;
896 		}
897 		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
898 		if (xrates != NULL)
899 			IEEE80211_VERIFY_ELEMENT(xrates,
900 				IEEE80211_RATE_MAXSIZE - rates[1], return);
901 		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
902 		IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
903 		if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
904 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
905 			    wh, NULL,
906 			    "%s", "no ssid with ssid suppression enabled");
907 			vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
908 			return;
909 		}
910 
911 		/* XXX find a better class or define it's own */
912 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
913 		    "%s", "recv probe req");
914 		/*
915 		 * Some legacy 11b clients cannot hack a complete
916 		 * probe response frame.  When the request includes
917 		 * only a bare-bones rate set, communicate this to
918 		 * the transmit side.
919 		 */
920 		ieee80211_send_proberesp(vap, wh->i_addr2,
921 		    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
922 
923 		/*
924 		 * Note: we don't benefit from stashing the probe request
925 		 * IEs away to use for IBSS negotiation, because we
926 		 * typically don't get all of the IEs.
927 		 */
928 		break;
929 
930 	case IEEE80211_FC0_SUBTYPE_ACTION:
931 	case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
932 		if ((ni == vap->iv_bss) &&
933 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
934 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
935 			    wh, NULL, "%s", "unknown node");
936 			vap->iv_stats.is_rx_mgtdiscard++;
937 		} else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
938 		    !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
939 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
940 			    wh, NULL, "%s", "not for us");
941 			vap->iv_stats.is_rx_mgtdiscard++;
942 		} else if (vap->iv_state != IEEE80211_S_RUN) {
943 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
944 			    wh, NULL, "wrong state %s",
945 			    ieee80211_state_name[vap->iv_state]);
946 			vap->iv_stats.is_rx_mgtdiscard++;
947 		} else {
948 			if (ieee80211_parse_action(ni, m0) == 0)
949 				(void)ic->ic_recv_action(ni, wh, frm, efrm);
950 		}
951 		break;
952 
953 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
954 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
955 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
956 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
957 	case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
958 	case IEEE80211_FC0_SUBTYPE_ATIM:
959 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
960 	case IEEE80211_FC0_SUBTYPE_AUTH:
961 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
962 		IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
963 		    wh, NULL, "%s", "not handled");
964 		vap->iv_stats.is_rx_mgtdiscard++;
965 		break;
966 
967 	default:
968 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
969 		    wh, "mgt", "subtype 0x%x not handled", subtype);
970 		vap->iv_stats.is_rx_badsubtype++;
971 		break;
972 	}
973 }
974 #undef IEEE80211_VERIFY_LENGTH
975 #undef IEEE80211_VERIFY_ELEMENT
976 
977 static void
978 ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
979 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
980 {
981 	struct ieee80211vap *vap = ni->ni_vap;
982 	struct ieee80211com *ic = ni->ni_ic;
983 	struct ieee80211_frame *wh;
984 
985 	/*
986 	 * Process management frames when scanning; useful for doing
987 	 * a site-survey.
988 	 */
989 	if (ic->ic_flags & IEEE80211_F_SCAN)
990 		adhoc_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
991 	else {
992 		wh = mtod(m0, struct ieee80211_frame *);
993 		switch (subtype) {
994 		case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
995 		case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
996 		case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
997 		case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
998 		case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
999 		case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1000 		case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
1001 		case IEEE80211_FC0_SUBTYPE_BEACON:
1002 		case IEEE80211_FC0_SUBTYPE_ATIM:
1003 		case IEEE80211_FC0_SUBTYPE_DISASSOC:
1004 		case IEEE80211_FC0_SUBTYPE_AUTH:
1005 		case IEEE80211_FC0_SUBTYPE_DEAUTH:
1006 		case IEEE80211_FC0_SUBTYPE_ACTION:
1007 		case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
1008 			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
1009 			     wh, NULL, "%s", "not handled");
1010 			vap->iv_stats.is_rx_mgtdiscard++;
1011 			break;
1012 		default:
1013 			IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
1014 			     wh, "mgt", "subtype 0x%x not handled", subtype);
1015 			vap->iv_stats.is_rx_badsubtype++;
1016 			break;
1017 		}
1018 	}
1019 }
1020 
1021 static void
1022 adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
1023 {
1024 
1025 	switch (subtype) {
1026 	case IEEE80211_FC0_SUBTYPE_BAR:
1027 		ieee80211_recv_bar(ni, m);
1028 		break;
1029 	}
1030 }
1031