xref: /freebsd/sys/net80211/ieee80211_input.c (revision 59aa14a91db84e940b6732cd1ff069f0268793bf)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_wlan.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/mbuf.h>
35 #include <sys/malloc.h>
36 #include <sys/endian.h>
37 #include <sys/kernel.h>
38 
39 #include <sys/socket.h>
40 
41 #include <net/ethernet.h>
42 #include <net/if.h>
43 #include <net/if_llc.h>
44 #include <net/if_media.h>
45 #include <net/if_vlan_var.h>
46 
47 #include <net80211/ieee80211_var.h>
48 #include <net80211/ieee80211_input.h>
49 #ifdef IEEE80211_SUPPORT_MESH
50 #include <net80211/ieee80211_mesh.h>
51 #endif
52 
53 #include <net/bpf.h>
54 
55 #ifdef INET
56 #include <netinet/in.h>
57 #include <net/ethernet.h>
58 #endif
59 
60 int
61 ieee80211_input_all(struct ieee80211com *ic, struct mbuf *m, int rssi, int nf)
62 {
63 	struct ieee80211vap *vap;
64 	int type = -1;
65 
66 	m->m_flags |= M_BCAST;		/* NB: mark for bpf tap'ing */
67 
68 	/* XXX locking */
69 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
70 		struct ieee80211_node *ni;
71 		struct mbuf *mcopy;
72 
73 		/* NB: could check for IFF_UP but this is cheaper */
74 		if (vap->iv_state == IEEE80211_S_INIT)
75 			continue;
76 		/*
77 		 * WDS vap's only receive directed traffic from the
78 		 * station at the ``far end''.  That traffic should
79 		 * be passed through the AP vap the station is associated
80 		 * to--so don't spam them with mcast frames.
81 		 */
82 		if (vap->iv_opmode == IEEE80211_M_WDS)
83 			continue;
84 		if (TAILQ_NEXT(vap, iv_next) != NULL) {
85 			/*
86 			 * Packet contents are changed by ieee80211_decap
87 			 * so do a deep copy of the packet.
88 			 */
89 			mcopy = m_dup(m, M_DONTWAIT);
90 			if (mcopy == NULL) {
91 				/* XXX stat+msg */
92 				continue;
93 			}
94 		} else {
95 			mcopy = m;
96 			m = NULL;
97 		}
98 		ni = ieee80211_ref_node(vap->iv_bss);
99 		type = ieee80211_input(ni, mcopy, rssi, nf);
100 		ieee80211_free_node(ni);
101 	}
102 	if (m != NULL)			/* no vaps, reclaim mbuf */
103 		m_freem(m);
104 	return type;
105 }
106 
107 /*
108  * This function reassembles fragments.
109  *
110  * XXX should handle 3 concurrent reassemblies per-spec.
111  */
112 struct mbuf *
113 ieee80211_defrag(struct ieee80211_node *ni, struct mbuf *m, int hdrspace)
114 {
115 	struct ieee80211vap *vap = ni->ni_vap;
116 	struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
117 	struct ieee80211_frame *lwh;
118 	uint16_t rxseq;
119 	uint8_t fragno;
120 	uint8_t more_frag = wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG;
121 	struct mbuf *mfrag;
122 
123 	KASSERT(!IEEE80211_IS_MULTICAST(wh->i_addr1), ("multicast fragm?"));
124 
125 	rxseq = le16toh(*(uint16_t *)wh->i_seq);
126 	fragno = rxseq & IEEE80211_SEQ_FRAG_MASK;
127 
128 	/* Quick way out, if there's nothing to defragment */
129 	if (!more_frag && fragno == 0 && ni->ni_rxfrag[0] == NULL)
130 		return m;
131 
132 	/*
133 	 * Remove frag to insure it doesn't get reaped by timer.
134 	 */
135 	if (ni->ni_table == NULL) {
136 		/*
137 		 * Should never happen.  If the node is orphaned (not in
138 		 * the table) then input packets should not reach here.
139 		 * Otherwise, a concurrent request that yanks the table
140 		 * should be blocked by other interlocking and/or by first
141 		 * shutting the driver down.  Regardless, be defensive
142 		 * here and just bail
143 		 */
144 		/* XXX need msg+stat */
145 		m_freem(m);
146 		return NULL;
147 	}
148 	IEEE80211_NODE_LOCK(ni->ni_table);
149 	mfrag = ni->ni_rxfrag[0];
150 	ni->ni_rxfrag[0] = NULL;
151 	IEEE80211_NODE_UNLOCK(ni->ni_table);
152 
153 	/*
154 	 * Validate new fragment is in order and
155 	 * related to the previous ones.
156 	 */
157 	if (mfrag != NULL) {
158 		uint16_t last_rxseq;
159 
160 		lwh = mtod(mfrag, struct ieee80211_frame *);
161 		last_rxseq = le16toh(*(uint16_t *)lwh->i_seq);
162 		/* NB: check seq # and frag together */
163 		if (rxseq != last_rxseq+1 ||
164 		    !IEEE80211_ADDR_EQ(wh->i_addr1, lwh->i_addr1) ||
165 		    !IEEE80211_ADDR_EQ(wh->i_addr2, lwh->i_addr2)) {
166 			/*
167 			 * Unrelated fragment or no space for it,
168 			 * clear current fragments.
169 			 */
170 			m_freem(mfrag);
171 			mfrag = NULL;
172 		}
173 	}
174 
175  	if (mfrag == NULL) {
176 		if (fragno != 0) {		/* !first fragment, discard */
177 			vap->iv_stats.is_rx_defrag++;
178 			IEEE80211_NODE_STAT(ni, rx_defrag);
179 			m_freem(m);
180 			return NULL;
181 		}
182 		mfrag = m;
183 	} else {				/* concatenate */
184 		m_adj(m, hdrspace);		/* strip header */
185 		m_cat(mfrag, m);
186 		/* NB: m_cat doesn't update the packet header */
187 		mfrag->m_pkthdr.len += m->m_pkthdr.len;
188 		/* track last seqnum and fragno */
189 		lwh = mtod(mfrag, struct ieee80211_frame *);
190 		*(uint16_t *) lwh->i_seq = *(uint16_t *) wh->i_seq;
191 	}
192 	if (more_frag) {			/* more to come, save */
193 		ni->ni_rxfragstamp = ticks;
194 		ni->ni_rxfrag[0] = mfrag;
195 		mfrag = NULL;
196 	}
197 	return mfrag;
198 }
199 
200 void
201 ieee80211_deliver_data(struct ieee80211vap *vap,
202 	struct ieee80211_node *ni, struct mbuf *m)
203 {
204 	struct ether_header *eh = mtod(m, struct ether_header *);
205 	struct ifnet *ifp = vap->iv_ifp;
206 
207 	/* clear driver/net80211 flags before passing up */
208 	m->m_flags &= ~(M_80211_RX | M_MCAST | M_BCAST);
209 
210 	/* NB: see hostap_deliver_data, this path doesn't handle hostap */
211 	KASSERT(vap->iv_opmode != IEEE80211_M_HOSTAP, ("gack, hostap"));
212 	/*
213 	 * Do accounting.
214 	 */
215 	ifp->if_ipackets++;
216 	IEEE80211_NODE_STAT(ni, rx_data);
217 	IEEE80211_NODE_STAT_ADD(ni, rx_bytes, m->m_pkthdr.len);
218 	if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
219 		m->m_flags |= M_MCAST;		/* XXX M_BCAST? */
220 		IEEE80211_NODE_STAT(ni, rx_mcast);
221 	} else
222 		IEEE80211_NODE_STAT(ni, rx_ucast);
223 	m->m_pkthdr.rcvif = ifp;
224 
225 	if (ni->ni_vlan != 0) {
226 		/* attach vlan tag */
227 		m->m_pkthdr.ether_vtag = ni->ni_vlan;
228 		m->m_flags |= M_VLANTAG;
229 	}
230 	ifp->if_input(ifp, m);
231 }
232 
233 struct mbuf *
234 ieee80211_decap(struct ieee80211vap *vap, struct mbuf *m, int hdrlen)
235 {
236 #ifdef IEEE80211_SUPPORT_MESH
237 	union {
238 		struct ieee80211_qosframe_addr4 wh4;
239 		uint8_t b[sizeof(struct ieee80211_qosframe_addr4) +
240 			  sizeof(struct ieee80211_meshcntl_ae11)];
241 	} whu;
242 #define	wh	whu.wh4
243 #else
244 	struct ieee80211_qosframe_addr4 wh;
245 #endif
246 	struct ether_header *eh;
247 	struct llc *llc;
248 
249 	if (m->m_len < hdrlen + sizeof(*llc) &&
250 	    (m = m_pullup(m, hdrlen + sizeof(*llc))) == NULL) {
251 		/* XXX stat, msg */
252 		return NULL;
253 	}
254 	memcpy(&wh, mtod(m, caddr_t), hdrlen);
255 	llc = (struct llc *)(mtod(m, caddr_t) + hdrlen);
256 	if (llc->llc_dsap == LLC_SNAP_LSAP && llc->llc_ssap == LLC_SNAP_LSAP &&
257 	    llc->llc_control == LLC_UI && llc->llc_snap.org_code[0] == 0 &&
258 	    llc->llc_snap.org_code[1] == 0 && llc->llc_snap.org_code[2] == 0 &&
259 	    /* NB: preserve AppleTalk frames that have a native SNAP hdr */
260 	    !(llc->llc_snap.ether_type == htons(ETHERTYPE_AARP) ||
261 	      llc->llc_snap.ether_type == htons(ETHERTYPE_IPX))) {
262 		m_adj(m, hdrlen + sizeof(struct llc) - sizeof(*eh));
263 		llc = NULL;
264 	} else {
265 		m_adj(m, hdrlen - sizeof(*eh));
266 	}
267 	eh = mtod(m, struct ether_header *);
268 	switch (wh.i_fc[1] & IEEE80211_FC1_DIR_MASK) {
269 	case IEEE80211_FC1_DIR_NODS:
270 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
271 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
272 		break;
273 	case IEEE80211_FC1_DIR_TODS:
274 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
275 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
276 		break;
277 	case IEEE80211_FC1_DIR_FROMDS:
278 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
279 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr3);
280 		break;
281 	case IEEE80211_FC1_DIR_DSTODS:
282 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
283 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr4);
284 		break;
285 	}
286 #ifdef ALIGNED_POINTER
287 	if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), uint32_t)) {
288 		struct mbuf *n, *n0, **np;
289 		caddr_t newdata;
290 		int off, pktlen;
291 
292 		n0 = NULL;
293 		np = &n0;
294 		off = 0;
295 		pktlen = m->m_pkthdr.len;
296 		while (pktlen > off) {
297 			if (n0 == NULL) {
298 				MGETHDR(n, M_DONTWAIT, MT_DATA);
299 				if (n == NULL) {
300 					m_freem(m);
301 					return NULL;
302 				}
303 				M_MOVE_PKTHDR(n, m);
304 				n->m_len = MHLEN;
305 			} else {
306 				MGET(n, M_DONTWAIT, MT_DATA);
307 				if (n == NULL) {
308 					m_freem(m);
309 					m_freem(n0);
310 					return NULL;
311 				}
312 				n->m_len = MLEN;
313 			}
314 			if (pktlen - off >= MINCLSIZE) {
315 				MCLGET(n, M_DONTWAIT);
316 				if (n->m_flags & M_EXT)
317 					n->m_len = n->m_ext.ext_size;
318 			}
319 			if (n0 == NULL) {
320 				newdata =
321 				    (caddr_t)ALIGN(n->m_data + sizeof(*eh)) -
322 				    sizeof(*eh);
323 				n->m_len -= newdata - n->m_data;
324 				n->m_data = newdata;
325 			}
326 			if (n->m_len > pktlen - off)
327 				n->m_len = pktlen - off;
328 			m_copydata(m, off, n->m_len, mtod(n, caddr_t));
329 			off += n->m_len;
330 			*np = n;
331 			np = &n->m_next;
332 		}
333 		m_freem(m);
334 		m = n0;
335 	}
336 #endif /* ALIGNED_POINTER */
337 	if (llc != NULL) {
338 		eh = mtod(m, struct ether_header *);
339 		eh->ether_type = htons(m->m_pkthdr.len - sizeof(*eh));
340 	}
341 	return m;
342 #undef	wh
343 }
344 
345 /*
346  * Decap a frame encapsulated in a fast-frame/A-MSDU.
347  */
348 struct mbuf *
349 ieee80211_decap1(struct mbuf *m, int *framelen)
350 {
351 #define	FF_LLC_SIZE	(sizeof(struct ether_header) + sizeof(struct llc))
352 	struct ether_header *eh;
353 	struct llc *llc;
354 
355 	/*
356 	 * The frame has an 802.3 header followed by an 802.2
357 	 * LLC header.  The encapsulated frame length is in the
358 	 * first header type field; save that and overwrite it
359 	 * with the true type field found in the second.  Then
360 	 * copy the 802.3 header up to where it belongs and
361 	 * adjust the mbuf contents to remove the void.
362 	 */
363 	if (m->m_len < FF_LLC_SIZE && (m = m_pullup(m, FF_LLC_SIZE)) == NULL)
364 		return NULL;
365 	eh = mtod(m, struct ether_header *);	/* 802.3 header is first */
366 	llc = (struct llc *)&eh[1];		/* 802.2 header follows */
367 	*framelen = ntohs(eh->ether_type)	/* encap'd frame size */
368 		  + sizeof(struct ether_header) - sizeof(struct llc);
369 	eh->ether_type = llc->llc_un.type_snap.ether_type;
370 	ovbcopy(eh, mtod(m, uint8_t *) + sizeof(struct llc),
371 		sizeof(struct ether_header));
372 	m_adj(m, sizeof(struct llc));
373 	return m;
374 #undef FF_LLC_SIZE
375 }
376 
377 /*
378  * Install received rate set information in the node's state block.
379  */
380 int
381 ieee80211_setup_rates(struct ieee80211_node *ni,
382 	const uint8_t *rates, const uint8_t *xrates, int flags)
383 {
384 	struct ieee80211vap *vap = ni->ni_vap;
385 	struct ieee80211_rateset *rs = &ni->ni_rates;
386 
387 	memset(rs, 0, sizeof(*rs));
388 	rs->rs_nrates = rates[1];
389 	memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
390 	if (xrates != NULL) {
391 		uint8_t nxrates;
392 		/*
393 		 * Tack on 11g extended supported rate element.
394 		 */
395 		nxrates = xrates[1];
396 		if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
397 			nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
398 			IEEE80211_NOTE(vap, IEEE80211_MSG_XRATE, ni,
399 			    "extended rate set too large; only using "
400 			    "%u of %u rates", nxrates, xrates[1]);
401 			vap->iv_stats.is_rx_rstoobig++;
402 		}
403 		memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
404 		rs->rs_nrates += nxrates;
405 	}
406 	return ieee80211_fix_rate(ni, rs, flags);
407 }
408 
409 /*
410  * Send a management frame error response to the specified
411  * station.  If ni is associated with the station then use
412  * it; otherwise allocate a temporary node suitable for
413  * transmitting the frame and then free the reference so
414  * it will go away as soon as the frame has been transmitted.
415  */
416 void
417 ieee80211_send_error(struct ieee80211_node *ni,
418 	const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg)
419 {
420 	struct ieee80211vap *vap = ni->ni_vap;
421 	int istmp;
422 
423 	if (ni == vap->iv_bss) {
424 		if (vap->iv_state != IEEE80211_S_RUN) {
425 			/*
426 			 * XXX hack until we get rid of this routine.
427 			 * We can be called prior to the vap reaching
428 			 * run state under certain conditions in which
429 			 * case iv_bss->ni_chan will not be setup.
430 			 * Check for this explicitly and and just ignore
431 			 * the request.
432 			 */
433 			return;
434 		}
435 		ni = ieee80211_tmp_node(vap, mac);
436 		if (ni == NULL) {
437 			/* XXX msg */
438 			return;
439 		}
440 		istmp = 1;
441 	} else
442 		istmp = 0;
443 	IEEE80211_SEND_MGMT(ni, subtype, arg);
444 	if (istmp)
445 		ieee80211_free_node(ni);
446 }
447 
448 int
449 ieee80211_alloc_challenge(struct ieee80211_node *ni)
450 {
451 	if (ni->ni_challenge == NULL)
452 		ni->ni_challenge = (uint32_t *) malloc(IEEE80211_CHALLENGE_LEN,
453 		    M_80211_NODE, M_NOWAIT);
454 	if (ni->ni_challenge == NULL) {
455 		IEEE80211_NOTE(ni->ni_vap,
456 		    IEEE80211_MSG_DEBUG | IEEE80211_MSG_AUTH, ni,
457 		    "%s", "shared key challenge alloc failed");
458 		/* XXX statistic */
459 	}
460 	return (ni->ni_challenge != NULL);
461 }
462 
463 /*
464  * Parse a Beacon or ProbeResponse frame and return the
465  * useful information in an ieee80211_scanparams structure.
466  * Status is set to 0 if no problems were found; otherwise
467  * a bitmask of IEEE80211_BPARSE_* items is returned that
468  * describes the problems detected.
469  */
470 int
471 ieee80211_parse_beacon(struct ieee80211_node *ni, struct mbuf *m,
472 	struct ieee80211_scanparams *scan)
473 {
474 	struct ieee80211vap *vap = ni->ni_vap;
475 	struct ieee80211com *ic = ni->ni_ic;
476 	struct ieee80211_frame *wh;
477 	uint8_t *frm, *efrm;
478 
479 	wh = mtod(m, struct ieee80211_frame *);
480 	frm = (uint8_t *)&wh[1];
481 	efrm = mtod(m, uint8_t *) + m->m_len;
482 	scan->status = 0;
483 	/*
484 	 * beacon/probe response frame format
485 	 *	[8] time stamp
486 	 *	[2] beacon interval
487 	 *	[2] capability information
488 	 *	[tlv] ssid
489 	 *	[tlv] supported rates
490 	 *	[tlv] country information
491 	 *	[tlv] channel switch announcement (CSA)
492 	 *	[tlv] parameter set (FH/DS)
493 	 *	[tlv] erp information
494 	 *	[tlv] extended supported rates
495 	 *	[tlv] WME
496 	 *	[tlv] WPA or RSN
497 	 *	[tlv] HT capabilities
498 	 *	[tlv] HT information
499 	 *	[tlv] Atheros capabilities
500 	 *	[tlv] Mesh ID
501 	 *	[tlv] Mesh Configuration
502 	 */
503 	IEEE80211_VERIFY_LENGTH(efrm - frm, 12,
504 	    return (scan->status = IEEE80211_BPARSE_BADIELEN));
505 	memset(scan, 0, sizeof(*scan));
506 	scan->tstamp  = frm;				frm += 8;
507 	scan->bintval = le16toh(*(uint16_t *)frm);	frm += 2;
508 	scan->capinfo = le16toh(*(uint16_t *)frm);	frm += 2;
509 	scan->bchan = ieee80211_chan2ieee(ic, ic->ic_curchan);
510 	scan->chan = scan->bchan;
511 	scan->ies = frm;
512 	scan->ies_len = efrm - frm;
513 
514 	while (efrm - frm > 1) {
515 		IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2,
516 		    return (scan->status = IEEE80211_BPARSE_BADIELEN));
517 		switch (*frm) {
518 		case IEEE80211_ELEMID_SSID:
519 			scan->ssid = frm;
520 			break;
521 		case IEEE80211_ELEMID_RATES:
522 			scan->rates = frm;
523 			break;
524 		case IEEE80211_ELEMID_COUNTRY:
525 			scan->country = frm;
526 			break;
527 		case IEEE80211_ELEMID_CSA:
528 			scan->csa = frm;
529 			break;
530 		case IEEE80211_ELEMID_FHPARMS:
531 			if (ic->ic_phytype == IEEE80211_T_FH) {
532 				scan->fhdwell = LE_READ_2(&frm[2]);
533 				scan->chan = IEEE80211_FH_CHAN(frm[4], frm[5]);
534 				scan->fhindex = frm[6];
535 			}
536 			break;
537 		case IEEE80211_ELEMID_DSPARMS:
538 			/*
539 			 * XXX hack this since depending on phytype
540 			 * is problematic for multi-mode devices.
541 			 */
542 			if (ic->ic_phytype != IEEE80211_T_FH)
543 				scan->chan = frm[2];
544 			break;
545 		case IEEE80211_ELEMID_TIM:
546 			/* XXX ATIM? */
547 			scan->tim = frm;
548 			scan->timoff = frm - mtod(m, uint8_t *);
549 			break;
550 		case IEEE80211_ELEMID_IBSSPARMS:
551 		case IEEE80211_ELEMID_CFPARMS:
552 		case IEEE80211_ELEMID_PWRCNSTR:
553 			/* NB: avoid debugging complaints */
554 			break;
555 		case IEEE80211_ELEMID_XRATES:
556 			scan->xrates = frm;
557 			break;
558 		case IEEE80211_ELEMID_ERP:
559 			if (frm[1] != 1) {
560 				IEEE80211_DISCARD_IE(vap,
561 				    IEEE80211_MSG_ELEMID, wh, "ERP",
562 				    "bad len %u", frm[1]);
563 				vap->iv_stats.is_rx_elem_toobig++;
564 				break;
565 			}
566 			scan->erp = frm[2] | 0x100;
567 			break;
568 		case IEEE80211_ELEMID_HTCAP:
569 			scan->htcap = frm;
570 			break;
571 		case IEEE80211_ELEMID_RSN:
572 			scan->rsn = frm;
573 			break;
574 		case IEEE80211_ELEMID_HTINFO:
575 			scan->htinfo = frm;
576 			break;
577 #ifdef IEEE80211_SUPPORT_TDMA
578 		case IEEE80211_ELEMID_MESHID:
579 			scan->meshid = frm;
580 			break;
581 		case IEEE80211_ELEMID_MESHCONF:
582 			scan->meshconf = frm;
583 			break;
584 #endif
585 		case IEEE80211_ELEMID_VENDOR:
586 			if (iswpaoui(frm))
587 				scan->wpa = frm;
588 			else if (iswmeparam(frm) || iswmeinfo(frm))
589 				scan->wme = frm;
590 #ifdef IEEE80211_SUPPORT_SUPERG
591 			else if (isatherosoui(frm))
592 				scan->ath = frm;
593 #endif
594 #ifdef IEEE80211_SUPPORT_TDMA
595 			else if (istdmaoui(frm))
596 				scan->tdma = frm;
597 #endif
598 			else if (vap->iv_flags_ht & IEEE80211_FHT_HTCOMPAT) {
599 				/*
600 				 * Accept pre-draft HT ie's if the
601 				 * standard ones have not been seen.
602 				 */
603 				if (ishtcapoui(frm)) {
604 					if (scan->htcap == NULL)
605 						scan->htcap = frm;
606 				} else if (ishtinfooui(frm)) {
607 					if (scan->htinfo == NULL)
608 						scan->htcap = frm;
609 				}
610 			}
611 			break;
612 		default:
613 			IEEE80211_DISCARD_IE(vap, IEEE80211_MSG_ELEMID,
614 			    wh, "unhandled",
615 			    "id %u, len %u", *frm, frm[1]);
616 			vap->iv_stats.is_rx_elem_unknown++;
617 			break;
618 		}
619 		frm += frm[1] + 2;
620 	}
621 	IEEE80211_VERIFY_ELEMENT(scan->rates, IEEE80211_RATE_MAXSIZE,
622 	    scan->status |= IEEE80211_BPARSE_RATES_INVALID);
623 	if (scan->rates != NULL && scan->xrates != NULL) {
624 		/*
625 		 * NB: don't process XRATES if RATES is missing.  This
626 		 * avoids a potential null ptr deref and should be ok
627 		 * as the return code will already note RATES is missing
628 		 * (so callers shouldn't otherwise process the frame).
629 		 */
630 		IEEE80211_VERIFY_ELEMENT(scan->xrates,
631 		    IEEE80211_RATE_MAXSIZE - scan->rates[1],
632 		    scan->status |= IEEE80211_BPARSE_XRATES_INVALID);
633 	}
634 	IEEE80211_VERIFY_ELEMENT(scan->ssid, IEEE80211_NWID_LEN,
635 	    scan->status |= IEEE80211_BPARSE_SSID_INVALID);
636 	if (scan->chan != scan->bchan && ic->ic_phytype != IEEE80211_T_FH) {
637 		/*
638 		 * Frame was received on a channel different from the
639 		 * one indicated in the DS params element id;
640 		 * silently discard it.
641 		 *
642 		 * NB: this can happen due to signal leakage.
643 		 *     But we should take it for FH phy because
644 		 *     the rssi value should be correct even for
645 		 *     different hop pattern in FH.
646 		 */
647 		IEEE80211_DISCARD(vap,
648 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
649 		    wh, NULL, "for off-channel %u", scan->chan);
650 		vap->iv_stats.is_rx_chanmismatch++;
651 		scan->status |= IEEE80211_BPARSE_OFFCHAN;
652 	}
653 	if (!(IEEE80211_BINTVAL_MIN <= scan->bintval &&
654 	      scan->bintval <= IEEE80211_BINTVAL_MAX)) {
655 		IEEE80211_DISCARD(vap,
656 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
657 		    wh, NULL, "bogus beacon interval", scan->bintval);
658 		vap->iv_stats.is_rx_badbintval++;
659 		scan->status |= IEEE80211_BPARSE_BINTVAL_INVALID;
660 	}
661 	if (scan->country != NULL) {
662 		/*
663 		 * Validate we have at least enough data to extract
664 		 * the country code.  Not sure if we should return an
665 		 * error instead of discarding the IE; consider this
666 		 * being lenient as we don't depend on the data for
667 		 * correct operation.
668 		 */
669 		IEEE80211_VERIFY_LENGTH(scan->country[1], 3 * sizeof(uint8_t),
670 		    scan->country = NULL);
671 	}
672 	if (scan->csa != NULL) {
673 		/*
674 		 * Validate Channel Switch Announcement; this must
675 		 * be the correct length or we toss the frame.
676 		 */
677 		IEEE80211_VERIFY_LENGTH(scan->csa[1], 3 * sizeof(uint8_t),
678 		    scan->status |= IEEE80211_BPARSE_CSA_INVALID);
679 	}
680 	/*
681 	 * Process HT ie's.  This is complicated by our
682 	 * accepting both the standard ie's and the pre-draft
683 	 * vendor OUI ie's that some vendors still use/require.
684 	 */
685 	if (scan->htcap != NULL) {
686 		IEEE80211_VERIFY_LENGTH(scan->htcap[1],
687 		     scan->htcap[0] == IEEE80211_ELEMID_VENDOR ?
688 			 4 + sizeof(struct ieee80211_ie_htcap)-2 :
689 			 sizeof(struct ieee80211_ie_htcap)-2,
690 		     scan->htcap = NULL);
691 	}
692 	if (scan->htinfo != NULL) {
693 		IEEE80211_VERIFY_LENGTH(scan->htinfo[1],
694 		     scan->htinfo[0] == IEEE80211_ELEMID_VENDOR ?
695 			 4 + sizeof(struct ieee80211_ie_htinfo)-2 :
696 			 sizeof(struct ieee80211_ie_htinfo)-2,
697 		     scan->htinfo = NULL);
698 	}
699 	return scan->status;
700 }
701 
702 /*
703  * Parse an Action frame.  Return 0 on success, non-zero on failure.
704  */
705 int
706 ieee80211_parse_action(struct ieee80211_node *ni, struct mbuf *m)
707 {
708 	struct ieee80211vap *vap = ni->ni_vap;
709 	const struct ieee80211_action *ia;
710 	struct ieee80211_frame *wh;
711 	uint8_t *frm, *efrm;
712 
713 	/*
714 	 * action frame format:
715 	 *	[1] category
716 	 *	[1] action
717 	 *	[tlv] parameters
718 	 */
719 	wh = mtod(m, struct ieee80211_frame *);
720 	frm = (u_int8_t *)&wh[1];
721 	efrm = mtod(m, u_int8_t *) + m->m_len;
722 	IEEE80211_VERIFY_LENGTH(efrm - frm,
723 		sizeof(struct ieee80211_action), return EINVAL);
724 	ia = (const struct ieee80211_action *) frm;
725 
726 	vap->iv_stats.is_rx_action++;
727 	IEEE80211_NODE_STAT(ni, rx_action);
728 
729 	/* verify frame payloads but defer processing */
730 	/* XXX maybe push this to method */
731 	switch (ia->ia_category) {
732 	case IEEE80211_ACTION_CAT_BA:
733 		switch (ia->ia_action) {
734 		case IEEE80211_ACTION_BA_ADDBA_REQUEST:
735 			IEEE80211_VERIFY_LENGTH(efrm - frm,
736 			    sizeof(struct ieee80211_action_ba_addbarequest),
737 			    return EINVAL);
738 			break;
739 		case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
740 			IEEE80211_VERIFY_LENGTH(efrm - frm,
741 			    sizeof(struct ieee80211_action_ba_addbaresponse),
742 			    return EINVAL);
743 			break;
744 		case IEEE80211_ACTION_BA_DELBA:
745 			IEEE80211_VERIFY_LENGTH(efrm - frm,
746 			    sizeof(struct ieee80211_action_ba_delba),
747 			    return EINVAL);
748 			break;
749 		}
750 		break;
751 	case IEEE80211_ACTION_CAT_HT:
752 		switch (ia->ia_action) {
753 		case IEEE80211_ACTION_HT_TXCHWIDTH:
754 			IEEE80211_VERIFY_LENGTH(efrm - frm,
755 			    sizeof(struct ieee80211_action_ht_txchwidth),
756 			    return EINVAL);
757 			break;
758 		case IEEE80211_ACTION_HT_MIMOPWRSAVE:
759 			IEEE80211_VERIFY_LENGTH(efrm - frm,
760 			    sizeof(struct ieee80211_action_ht_mimopowersave),
761 			    return EINVAL);
762 			break;
763 		}
764 		break;
765 	}
766 	return 0;
767 }
768 
769 #ifdef IEEE80211_DEBUG
770 /*
771  * Debugging support.
772  */
773 void
774 ieee80211_ssid_mismatch(struct ieee80211vap *vap, const char *tag,
775 	uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid)
776 {
777 	printf("[%s] discard %s frame, ssid mismatch: ",
778 		ether_sprintf(mac), tag);
779 	ieee80211_print_essid(ssid + 2, ssid[1]);
780 	printf("\n");
781 }
782 
783 /*
784  * Return the bssid of a frame.
785  */
786 static const uint8_t *
787 ieee80211_getbssid(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
788 {
789 	if (vap->iv_opmode == IEEE80211_M_STA)
790 		return wh->i_addr2;
791 	if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) != IEEE80211_FC1_DIR_NODS)
792 		return wh->i_addr1;
793 	if ((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
794 		return wh->i_addr1;
795 	return wh->i_addr3;
796 }
797 
798 #include <machine/stdarg.h>
799 
800 void
801 ieee80211_note(struct ieee80211vap *vap, const char *fmt, ...)
802 {
803 	char buf[128];		/* XXX */
804 	va_list ap;
805 
806 	va_start(ap, fmt);
807 	vsnprintf(buf, sizeof(buf), fmt, ap);
808 	va_end(ap);
809 
810 	if_printf(vap->iv_ifp, "%s", buf);	/* NB: no \n */
811 }
812 
813 void
814 ieee80211_note_frame(struct ieee80211vap *vap,
815 	const struct ieee80211_frame *wh,
816 	const char *fmt, ...)
817 {
818 	char buf[128];		/* XXX */
819 	va_list ap;
820 
821 	va_start(ap, fmt);
822 	vsnprintf(buf, sizeof(buf), fmt, ap);
823 	va_end(ap);
824 	if_printf(vap->iv_ifp, "[%s] %s\n",
825 		ether_sprintf(ieee80211_getbssid(vap, wh)), buf);
826 }
827 
828 void
829 ieee80211_note_mac(struct ieee80211vap *vap,
830 	const uint8_t mac[IEEE80211_ADDR_LEN],
831 	const char *fmt, ...)
832 {
833 	char buf[128];		/* XXX */
834 	va_list ap;
835 
836 	va_start(ap, fmt);
837 	vsnprintf(buf, sizeof(buf), fmt, ap);
838 	va_end(ap);
839 	if_printf(vap->iv_ifp, "[%s] %s\n", ether_sprintf(mac), buf);
840 }
841 
842 void
843 ieee80211_discard_frame(struct ieee80211vap *vap,
844 	const struct ieee80211_frame *wh,
845 	const char *type, const char *fmt, ...)
846 {
847 	va_list ap;
848 
849 	if_printf(vap->iv_ifp, "[%s] discard ",
850 		ether_sprintf(ieee80211_getbssid(vap, wh)));
851 	if (type == NULL) {
852 		printf("%s frame, ", ieee80211_mgt_subtype_name[
853 			(wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) >>
854 			IEEE80211_FC0_SUBTYPE_SHIFT]);
855 	} else
856 		printf("%s frame, ", type);
857 	va_start(ap, fmt);
858 	vprintf(fmt, ap);
859 	va_end(ap);
860 	printf("\n");
861 }
862 
863 void
864 ieee80211_discard_ie(struct ieee80211vap *vap,
865 	const struct ieee80211_frame *wh,
866 	const char *type, const char *fmt, ...)
867 {
868 	va_list ap;
869 
870 	if_printf(vap->iv_ifp, "[%s] discard ",
871 		ether_sprintf(ieee80211_getbssid(vap, wh)));
872 	if (type != NULL)
873 		printf("%s information element, ", type);
874 	else
875 		printf("information element, ");
876 	va_start(ap, fmt);
877 	vprintf(fmt, ap);
878 	va_end(ap);
879 	printf("\n");
880 }
881 
882 void
883 ieee80211_discard_mac(struct ieee80211vap *vap,
884 	const uint8_t mac[IEEE80211_ADDR_LEN],
885 	const char *type, const char *fmt, ...)
886 {
887 	va_list ap;
888 
889 	if_printf(vap->iv_ifp, "[%s] discard ", ether_sprintf(mac));
890 	if (type != NULL)
891 		printf("%s frame, ", type);
892 	else
893 		printf("frame, ");
894 	va_start(ap, fmt);
895 	vprintf(fmt, ap);
896 	va_end(ap);
897 	printf("\n");
898 }
899 #endif /* IEEE80211_DEBUG */
900