xref: /freebsd/sys/net80211/ieee80211_input.c (revision cacdd70cc751fb68dec4b86c5e5b8c969b6e26ef)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002-2008 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 
50 #include <net/bpf.h>
51 
52 #ifdef INET
53 #include <netinet/in.h>
54 #include <net/ethernet.h>
55 #endif
56 
57 int
58 ieee80211_input_all(struct ieee80211com *ic,
59 	struct mbuf *m, int rssi, int noise, u_int32_t rstamp)
60 {
61 	struct ieee80211vap *vap;
62 	int type = -1;
63 
64 	/* XXX locking */
65 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
66 		struct ieee80211_node *ni;
67 		struct mbuf *mcopy;
68 
69 		/*
70 		 * WDS vap's only receive directed traffic from the
71 		 * station at the ``far end''.  That traffic should
72 		 * be passed through the AP vap the station is associated
73 		 * to--so don't spam them with mcast frames.
74 		 */
75 		if (vap->iv_opmode == IEEE80211_M_WDS)
76 			continue;
77 		if (TAILQ_NEXT(vap, iv_next) != NULL) {
78 			/*
79 			 * Packet contents are changed by ieee80211_decap
80 			 * so do a deep copy of the packet.
81 			 */
82 			mcopy = m_dup(m, M_DONTWAIT);
83 			if (mcopy == NULL) {
84 				/* XXX stat+msg */
85 				continue;
86 			}
87 		} else {
88 			mcopy = m;
89 			m = NULL;
90 		}
91 		ni = ieee80211_ref_node(vap->iv_bss);
92 		type = ieee80211_input(ni, mcopy, rssi, noise, rstamp);
93 		ieee80211_free_node(ni);
94 	}
95 	if (m != NULL)			/* no vaps, reclaim mbuf */
96 		m_freem(m);
97 	return type;
98 }
99 
100 /*
101  * This function reassemble fragments.
102  *
103  * XXX should handle 3 concurrent reassemblies per-spec.
104  */
105 struct mbuf *
106 ieee80211_defrag(struct ieee80211_node *ni, struct mbuf *m, int hdrspace)
107 {
108 	struct ieee80211vap *vap = ni->ni_vap;
109 	struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
110 	struct ieee80211_frame *lwh;
111 	uint16_t rxseq;
112 	uint8_t fragno;
113 	uint8_t more_frag = wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG;
114 	struct mbuf *mfrag;
115 
116 	KASSERT(!IEEE80211_IS_MULTICAST(wh->i_addr1), ("multicast fragm?"));
117 
118 	rxseq = le16toh(*(uint16_t *)wh->i_seq);
119 	fragno = rxseq & IEEE80211_SEQ_FRAG_MASK;
120 
121 	/* Quick way out, if there's nothing to defragment */
122 	if (!more_frag && fragno == 0 && ni->ni_rxfrag[0] == NULL)
123 		return m;
124 
125 	/*
126 	 * Remove frag to insure it doesn't get reaped by timer.
127 	 */
128 	if (ni->ni_table == NULL) {
129 		/*
130 		 * Should never happen.  If the node is orphaned (not in
131 		 * the table) then input packets should not reach here.
132 		 * Otherwise, a concurrent request that yanks the table
133 		 * should be blocked by other interlocking and/or by first
134 		 * shutting the driver down.  Regardless, be defensive
135 		 * here and just bail
136 		 */
137 		/* XXX need msg+stat */
138 		m_freem(m);
139 		return NULL;
140 	}
141 	IEEE80211_NODE_LOCK(ni->ni_table);
142 	mfrag = ni->ni_rxfrag[0];
143 	ni->ni_rxfrag[0] = NULL;
144 	IEEE80211_NODE_UNLOCK(ni->ni_table);
145 
146 	/*
147 	 * Validate new fragment is in order and
148 	 * related to the previous ones.
149 	 */
150 	if (mfrag != NULL) {
151 		uint16_t last_rxseq;
152 
153 		lwh = mtod(mfrag, struct ieee80211_frame *);
154 		last_rxseq = le16toh(*(uint16_t *)lwh->i_seq);
155 		/* NB: check seq # and frag together */
156 		if (rxseq != last_rxseq+1 ||
157 		    !IEEE80211_ADDR_EQ(wh->i_addr1, lwh->i_addr1) ||
158 		    !IEEE80211_ADDR_EQ(wh->i_addr2, lwh->i_addr2)) {
159 			/*
160 			 * Unrelated fragment or no space for it,
161 			 * clear current fragments.
162 			 */
163 			m_freem(mfrag);
164 			mfrag = NULL;
165 		}
166 	}
167 
168  	if (mfrag == NULL) {
169 		if (fragno != 0) {		/* !first fragment, discard */
170 			vap->iv_stats.is_rx_defrag++;
171 			IEEE80211_NODE_STAT(ni, rx_defrag);
172 			m_freem(m);
173 			return NULL;
174 		}
175 		mfrag = m;
176 	} else {				/* concatenate */
177 		m_adj(m, hdrspace);		/* strip header */
178 		m_cat(mfrag, m);
179 		/* NB: m_cat doesn't update the packet header */
180 		mfrag->m_pkthdr.len += m->m_pkthdr.len;
181 		/* track last seqnum and fragno */
182 		lwh = mtod(mfrag, struct ieee80211_frame *);
183 		*(uint16_t *) lwh->i_seq = *(uint16_t *) wh->i_seq;
184 	}
185 	if (more_frag) {			/* more to come, save */
186 		ni->ni_rxfragstamp = ticks;
187 		ni->ni_rxfrag[0] = mfrag;
188 		mfrag = NULL;
189 	}
190 	return mfrag;
191 }
192 
193 void
194 ieee80211_deliver_data(struct ieee80211vap *vap,
195 	struct ieee80211_node *ni, struct mbuf *m)
196 {
197 	struct ether_header *eh = mtod(m, struct ether_header *);
198 	struct ifnet *ifp = vap->iv_ifp;
199 
200 	/* NB: see hostap_deliver_data, this path doesn't handle hostap */
201 	KASSERT(vap->iv_opmode != IEEE80211_M_HOSTAP, ("gack, hostap"));
202 	/*
203 	 * Do accounting.
204 	 */
205 	ifp->if_ipackets++;
206 	IEEE80211_NODE_STAT(ni, rx_data);
207 	IEEE80211_NODE_STAT_ADD(ni, rx_bytes, m->m_pkthdr.len);
208 	if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
209 		m->m_flags |= M_MCAST;		/* XXX M_BCAST? */
210 		IEEE80211_NODE_STAT(ni, rx_mcast);
211 	} else
212 		IEEE80211_NODE_STAT(ni, rx_ucast);
213 	m->m_pkthdr.rcvif = ifp;
214 
215 	/* clear driver/net80211 flags before passing up */
216 	m->m_flags &= ~M_80211_RX;
217 
218 	if (ni->ni_vlan != 0) {
219 		/* attach vlan tag */
220 		m->m_pkthdr.ether_vtag = ni->ni_vlan;
221 		m->m_flags |= M_VLANTAG;
222 	}
223 	ifp->if_input(ifp, m);
224 }
225 
226 struct mbuf *
227 ieee80211_decap(struct ieee80211vap *vap, struct mbuf *m, int hdrlen)
228 {
229 	struct ieee80211_qosframe_addr4 wh;	/* Max size address frames */
230 	struct ether_header *eh;
231 	struct llc *llc;
232 
233 	if (m->m_len < hdrlen + sizeof(*llc) &&
234 	    (m = m_pullup(m, hdrlen + sizeof(*llc))) == NULL) {
235 		/* XXX stat, msg */
236 		return NULL;
237 	}
238 	memcpy(&wh, mtod(m, caddr_t), hdrlen);
239 	llc = (struct llc *)(mtod(m, caddr_t) + hdrlen);
240 	if (llc->llc_dsap == LLC_SNAP_LSAP && llc->llc_ssap == LLC_SNAP_LSAP &&
241 	    llc->llc_control == LLC_UI && llc->llc_snap.org_code[0] == 0 &&
242 	    llc->llc_snap.org_code[1] == 0 && llc->llc_snap.org_code[2] == 0 &&
243 	    /* NB: preserve AppleTalk frames that have a native SNAP hdr */
244 	    !(llc->llc_snap.ether_type == htons(ETHERTYPE_AARP) ||
245 	      llc->llc_snap.ether_type == htons(ETHERTYPE_IPX))) {
246 		m_adj(m, hdrlen + sizeof(struct llc) - sizeof(*eh));
247 		llc = NULL;
248 	} else {
249 		m_adj(m, hdrlen - sizeof(*eh));
250 	}
251 	eh = mtod(m, struct ether_header *);
252 	switch (wh.i_fc[1] & IEEE80211_FC1_DIR_MASK) {
253 	case IEEE80211_FC1_DIR_NODS:
254 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
255 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
256 		break;
257 	case IEEE80211_FC1_DIR_TODS:
258 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
259 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
260 		break;
261 	case IEEE80211_FC1_DIR_FROMDS:
262 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
263 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr3);
264 		break;
265 	case IEEE80211_FC1_DIR_DSTODS:
266 		IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
267 		IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr4);
268 		break;
269 	}
270 #ifdef ALIGNED_POINTER
271 	if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), uint32_t)) {
272 		struct mbuf *n, *n0, **np;
273 		caddr_t newdata;
274 		int off, pktlen;
275 
276 		n0 = NULL;
277 		np = &n0;
278 		off = 0;
279 		pktlen = m->m_pkthdr.len;
280 		while (pktlen > off) {
281 			if (n0 == NULL) {
282 				MGETHDR(n, M_DONTWAIT, MT_DATA);
283 				if (n == NULL) {
284 					m_freem(m);
285 					return NULL;
286 				}
287 				M_MOVE_PKTHDR(n, m);
288 				n->m_len = MHLEN;
289 			} else {
290 				MGET(n, M_DONTWAIT, MT_DATA);
291 				if (n == NULL) {
292 					m_freem(m);
293 					m_freem(n0);
294 					return NULL;
295 				}
296 				n->m_len = MLEN;
297 			}
298 			if (pktlen - off >= MINCLSIZE) {
299 				MCLGET(n, M_DONTWAIT);
300 				if (n->m_flags & M_EXT)
301 					n->m_len = n->m_ext.ext_size;
302 			}
303 			if (n0 == NULL) {
304 				newdata =
305 				    (caddr_t)ALIGN(n->m_data + sizeof(*eh)) -
306 				    sizeof(*eh);
307 				n->m_len -= newdata - n->m_data;
308 				n->m_data = newdata;
309 			}
310 			if (n->m_len > pktlen - off)
311 				n->m_len = pktlen - off;
312 			m_copydata(m, off, n->m_len, mtod(n, caddr_t));
313 			off += n->m_len;
314 			*np = n;
315 			np = &n->m_next;
316 		}
317 		m_freem(m);
318 		m = n0;
319 	}
320 #endif /* ALIGNED_POINTER */
321 	if (llc != NULL) {
322 		eh = mtod(m, struct ether_header *);
323 		eh->ether_type = htons(m->m_pkthdr.len - sizeof(*eh));
324 	}
325 	return m;
326 }
327 
328 /*
329  * Decap a frame encapsulated in a fast-frame/A-MSDU.
330  */
331 struct mbuf *
332 ieee80211_decap1(struct mbuf *m, int *framelen)
333 {
334 #define	FF_LLC_SIZE	(sizeof(struct ether_header) + sizeof(struct llc))
335 	struct ether_header *eh;
336 	struct llc *llc;
337 
338 	/*
339 	 * The frame has an 802.3 header followed by an 802.2
340 	 * LLC header.  The encapsulated frame length is in the
341 	 * first header type field; save that and overwrite it
342 	 * with the true type field found in the second.  Then
343 	 * copy the 802.3 header up to where it belongs and
344 	 * adjust the mbuf contents to remove the void.
345 	 */
346 	if (m->m_len < FF_LLC_SIZE && (m = m_pullup(m, FF_LLC_SIZE)) == NULL)
347 		return NULL;
348 	eh = mtod(m, struct ether_header *);	/* 802.3 header is first */
349 	llc = (struct llc *)&eh[1];		/* 802.2 header follows */
350 	*framelen = ntohs(eh->ether_type)	/* encap'd frame size */
351 		  + sizeof(struct ether_header) - sizeof(struct llc);
352 	eh->ether_type = llc->llc_un.type_snap.ether_type;
353 	ovbcopy(eh, mtod(m, uint8_t *) + sizeof(struct llc),
354 		sizeof(struct ether_header));
355 	m_adj(m, sizeof(struct llc));
356 	return m;
357 #undef FF_LLC_SIZE
358 }
359 
360 /*
361  * Decap the encapsulated frame pair and dispatch the first
362  * for delivery.  The second frame is returned for delivery
363  * via the normal path.
364  */
365 struct mbuf *
366 ieee80211_decap_fastframe(struct ieee80211_node *ni, struct mbuf *m)
367 {
368 #define	MS(x,f)	(((x) & f) >> f##_S)
369 	struct ieee80211vap *vap = ni->ni_vap;
370 	uint32_t ath;
371 	struct mbuf *n;
372 	int framelen;
373 
374 	m_copydata(m, 0, sizeof(uint32_t), (caddr_t) &ath);
375 	if (MS(ath, ATH_FF_PROTO) != ATH_FF_PROTO_L2TUNNEL) {
376 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
377 		    ni->ni_macaddr, "fast-frame",
378 		    "unsupport tunnel protocol, header 0x%x", ath);
379 		vap->iv_stats.is_ff_badhdr++;
380 		m_freem(m);
381 		return NULL;
382 	}
383 	/* NB: skip header and alignment padding */
384 	m_adj(m, roundup(sizeof(uint32_t) - 2, 4) + 2);
385 
386 	vap->iv_stats.is_ff_decap++;
387 
388 	/*
389 	 * Decap the first frame, bust it apart from the
390 	 * second and deliver; then decap the second frame
391 	 * and return it to the caller for normal delivery.
392 	 */
393 	m = ieee80211_decap1(m, &framelen);
394 	if (m == NULL) {
395 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
396 		    ni->ni_macaddr, "fast-frame", "%s", "first decap failed");
397 		vap->iv_stats.is_ff_tooshort++;
398 		return NULL;
399 	}
400 	n = m_split(m, framelen, M_NOWAIT);
401 	if (n == NULL) {
402 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
403 		    ni->ni_macaddr, "fast-frame",
404 		    "%s", "unable to split encapsulated frames");
405 		vap->iv_stats.is_ff_split++;
406 		m_freem(m);			/* NB: must reclaim */
407 		return NULL;
408 	}
409 	/* XXX not right for WDS */
410 	vap->iv_deliver_data(vap, ni, m);	/* 1st of pair */
411 
412 	/*
413 	 * Decap second frame.
414 	 */
415 	m_adj(n, roundup2(framelen, 4) - framelen);	/* padding */
416 	n = ieee80211_decap1(n, &framelen);
417 	if (n == NULL) {
418 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
419 		    ni->ni_macaddr, "fast-frame", "%s", "second decap failed");
420 		vap->iv_stats.is_ff_tooshort++;
421 	}
422 	/* XXX verify framelen against mbuf contents */
423 	return n;				/* 2nd delivered by caller */
424 #undef MS
425 }
426 
427 /*
428  * Install received rate set information in the node's state block.
429  */
430 int
431 ieee80211_setup_rates(struct ieee80211_node *ni,
432 	const uint8_t *rates, const uint8_t *xrates, int flags)
433 {
434 	struct ieee80211vap *vap = ni->ni_vap;
435 	struct ieee80211_rateset *rs = &ni->ni_rates;
436 
437 	memset(rs, 0, sizeof(*rs));
438 	rs->rs_nrates = rates[1];
439 	memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
440 	if (xrates != NULL) {
441 		uint8_t nxrates;
442 		/*
443 		 * Tack on 11g extended supported rate element.
444 		 */
445 		nxrates = xrates[1];
446 		if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
447 			nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
448 			IEEE80211_NOTE(vap, IEEE80211_MSG_XRATE, ni,
449 			    "extended rate set too large; only using "
450 			    "%u of %u rates", nxrates, xrates[1]);
451 			vap->iv_stats.is_rx_rstoobig++;
452 		}
453 		memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
454 		rs->rs_nrates += nxrates;
455 	}
456 	return ieee80211_fix_rate(ni, rs, flags);
457 }
458 
459 /*
460  * Send a management frame error response to the specified
461  * station.  If ni is associated with the station then use
462  * it; otherwise allocate a temporary node suitable for
463  * transmitting the frame and then free the reference so
464  * it will go away as soon as the frame has been transmitted.
465  */
466 void
467 ieee80211_send_error(struct ieee80211_node *ni,
468 	const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg)
469 {
470 	struct ieee80211vap *vap = ni->ni_vap;
471 	int istmp;
472 
473 	if (ni == vap->iv_bss) {
474 		if (vap->iv_state != IEEE80211_S_RUN) {
475 			/*
476 			 * XXX hack until we get rid of this routine.
477 			 * We can be called prior to the vap reaching
478 			 * run state under certain conditions in which
479 			 * case iv_bss->ni_chan will not be setup.
480 			 * Check for this explicitly and and just ignore
481 			 * the request.
482 			 */
483 			return;
484 		}
485 		ni = ieee80211_tmp_node(vap, mac);
486 		if (ni == NULL) {
487 			/* XXX msg */
488 			return;
489 		}
490 		istmp = 1;
491 	} else
492 		istmp = 0;
493 	IEEE80211_SEND_MGMT(ni, subtype, arg);
494 	if (istmp)
495 		ieee80211_free_node(ni);
496 }
497 
498 int
499 ieee80211_alloc_challenge(struct ieee80211_node *ni)
500 {
501 	if (ni->ni_challenge == NULL)
502 		MALLOC(ni->ni_challenge, uint32_t*, IEEE80211_CHALLENGE_LEN,
503 		    M_80211_NODE, M_NOWAIT);
504 	if (ni->ni_challenge == NULL) {
505 		IEEE80211_NOTE(ni->ni_vap,
506 		    IEEE80211_MSG_DEBUG | IEEE80211_MSG_AUTH, ni,
507 		    "%s", "shared key challenge alloc failed");
508 		/* XXX statistic */
509 	}
510 	return (ni->ni_challenge != NULL);
511 }
512 
513 void
514 ieee80211_parse_ath(struct ieee80211_node *ni, uint8_t *ie)
515 {
516 	const struct ieee80211_ath_ie *ath =
517 		(const struct ieee80211_ath_ie *) ie;
518 
519 	ni->ni_ath_flags = ath->ath_capability;
520 	ni->ni_ath_defkeyix = LE_READ_2(&ath->ath_defkeyix);
521 }
522 
523 /*
524  * Parse a Beacon or ProbeResponse frame and return the
525  * useful information in an ieee80211_scanparams structure.
526  * Status is set to 0 if no problems were found; otherwise
527  * a bitmask of IEEE80211_BPARSE_* items is returned that
528  * describes the problems detected.
529  */
530 int
531 ieee80211_parse_beacon(struct ieee80211_node *ni, struct mbuf *m,
532 	struct ieee80211_scanparams *scan)
533 {
534 	struct ieee80211vap *vap = ni->ni_vap;
535 	struct ieee80211com *ic = ni->ni_ic;
536 	struct ieee80211_frame *wh;
537 	uint8_t *frm, *efrm;
538 
539 	wh = mtod(m, struct ieee80211_frame *);
540 	frm = (uint8_t *)&wh[1];
541 	efrm = mtod(m, uint8_t *) + m->m_len;
542 	scan->status = 0;
543 	/*
544 	 * beacon/probe response frame format
545 	 *	[8] time stamp
546 	 *	[2] beacon interval
547 	 *	[2] capability information
548 	 *	[tlv] ssid
549 	 *	[tlv] supported rates
550 	 *	[tlv] country information
551 	 *	[tlv] parameter set (FH/DS)
552 	 *	[tlv] erp information
553 	 *	[tlv] extended supported rates
554 	 *	[tlv] WME
555 	 *	[tlv] WPA or RSN
556 	 *	[tlv] HT capabilities
557 	 *	[tlv] HT information
558 	 *	[tlv] Atheros capabilities
559 	 */
560 	IEEE80211_VERIFY_LENGTH(efrm - frm, 12,
561 	    return (scan->status = IEEE80211_BPARSE_BADIELEN));
562 	memset(scan, 0, sizeof(*scan));
563 	scan->tstamp  = frm;				frm += 8;
564 	scan->bintval = le16toh(*(uint16_t *)frm);	frm += 2;
565 	scan->capinfo = le16toh(*(uint16_t *)frm);	frm += 2;
566 	scan->bchan = ieee80211_chan2ieee(ic, ic->ic_curchan);
567 	scan->chan = scan->bchan;
568 	scan->ies = frm;
569 	scan->ies_len = efrm - frm;
570 
571 	while (efrm - frm > 1) {
572 		IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2,
573 		    return (scan->status = IEEE80211_BPARSE_BADIELEN));
574 		switch (*frm) {
575 		case IEEE80211_ELEMID_SSID:
576 			scan->ssid = frm;
577 			break;
578 		case IEEE80211_ELEMID_RATES:
579 			scan->rates = frm;
580 			break;
581 		case IEEE80211_ELEMID_COUNTRY:
582 			scan->country = frm;
583 			break;
584 		case IEEE80211_ELEMID_FHPARMS:
585 			if (ic->ic_phytype == IEEE80211_T_FH) {
586 				scan->fhdwell = LE_READ_2(&frm[2]);
587 				scan->chan = IEEE80211_FH_CHAN(frm[4], frm[5]);
588 				scan->fhindex = frm[6];
589 			}
590 			break;
591 		case IEEE80211_ELEMID_DSPARMS:
592 			/*
593 			 * XXX hack this since depending on phytype
594 			 * is problematic for multi-mode devices.
595 			 */
596 			if (ic->ic_phytype != IEEE80211_T_FH)
597 				scan->chan = frm[2];
598 			break;
599 		case IEEE80211_ELEMID_TIM:
600 			/* XXX ATIM? */
601 			scan->tim = frm;
602 			scan->timoff = frm - mtod(m, uint8_t *);
603 			break;
604 		case IEEE80211_ELEMID_IBSSPARMS:
605 		case IEEE80211_ELEMID_CFPARMS:
606 			/* NB: avoid debugging complaints */
607 			break;
608 		case IEEE80211_ELEMID_XRATES:
609 			scan->xrates = frm;
610 			break;
611 		case IEEE80211_ELEMID_ERP:
612 			if (frm[1] != 1) {
613 				IEEE80211_DISCARD_IE(vap,
614 				    IEEE80211_MSG_ELEMID, wh, "ERP",
615 				    "bad len %u", frm[1]);
616 				vap->iv_stats.is_rx_elem_toobig++;
617 				break;
618 			}
619 			scan->erp = frm[2] | 0x100;
620 			break;
621 		case IEEE80211_ELEMID_HTCAP:
622 			scan->htcap = frm;
623 			break;
624 		case IEEE80211_ELEMID_RSN:
625 			scan->rsn = frm;
626 			break;
627 		case IEEE80211_ELEMID_HTINFO:
628 			scan->htinfo = frm;
629 			break;
630 		case IEEE80211_ELEMID_VENDOR:
631 			if (iswpaoui(frm))
632 				scan->wpa = frm;
633 			else if (iswmeparam(frm) || iswmeinfo(frm))
634 				scan->wme = frm;
635 			else if (isatherosoui(frm))
636 				scan->ath = frm;
637 			else if (vap->iv_flags_ext & IEEE80211_FEXT_HTCOMPAT) {
638 				/*
639 				 * Accept pre-draft HT ie's if the
640 				 * standard ones have not been seen.
641 				 */
642 				if (ishtcapoui(frm)) {
643 					if (scan->htcap == NULL)
644 						scan->htcap = frm;
645 				} else if (ishtinfooui(frm)) {
646 					if (scan->htinfo == NULL)
647 						scan->htcap = frm;
648 				}
649 			}
650 			break;
651 		default:
652 			IEEE80211_DISCARD_IE(vap, IEEE80211_MSG_ELEMID,
653 			    wh, "unhandled",
654 			    "id %u, len %u", *frm, frm[1]);
655 			vap->iv_stats.is_rx_elem_unknown++;
656 			break;
657 		}
658 		frm += frm[1] + 2;
659 	}
660 	IEEE80211_VERIFY_ELEMENT(scan->rates, IEEE80211_RATE_MAXSIZE,
661 	    scan->status |= IEEE80211_BPARSE_RATES_INVALID);
662 	if (scan->rates != NULL && scan->xrates != NULL) {
663 		/*
664 		 * NB: don't process XRATES if RATES is missing.  This
665 		 * avoids a potential null ptr deref and should be ok
666 		 * as the return code will already note RATES is missing
667 		 * (so callers shouldn't otherwise process the frame).
668 		 */
669 		IEEE80211_VERIFY_ELEMENT(scan->xrates,
670 		    IEEE80211_RATE_MAXSIZE - scan->rates[1],
671 		    scan->status |= IEEE80211_BPARSE_XRATES_INVALID);
672 	}
673 	IEEE80211_VERIFY_ELEMENT(scan->ssid, IEEE80211_NWID_LEN,
674 	    scan->status |= IEEE80211_BPARSE_SSID_INVALID);
675 #if IEEE80211_CHAN_MAX < 255
676 	if (scan->chan > IEEE80211_CHAN_MAX) {
677 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,
678 		    wh, NULL, "invalid channel %u", scan->chan);
679 		vap->iv_stats.is_rx_badchan++;
680 		scan->status |= IEEE80211_BPARSE_CHAN_INVALID;
681 	}
682 #endif
683 	if (scan->chan != scan->bchan && ic->ic_phytype != IEEE80211_T_FH) {
684 		/*
685 		 * Frame was received on a channel different from the
686 		 * one indicated in the DS params element id;
687 		 * silently discard it.
688 		 *
689 		 * NB: this can happen due to signal leakage.
690 		 *     But we should take it for FH phy because
691 		 *     the rssi value should be correct even for
692 		 *     different hop pattern in FH.
693 		 */
694 		IEEE80211_DISCARD(vap,
695 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
696 		    wh, NULL, "for off-channel %u", scan->chan);
697 		vap->iv_stats.is_rx_chanmismatch++;
698 		scan->status |= IEEE80211_BPARSE_OFFCHAN;
699 	}
700 	if (!(IEEE80211_BINTVAL_MIN <= scan->bintval &&
701 	      scan->bintval <= IEEE80211_BINTVAL_MAX)) {
702 		IEEE80211_DISCARD(vap,
703 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
704 		    wh, NULL, "bogus beacon interval", scan->bintval);
705 		vap->iv_stats.is_rx_badbintval++;
706 		scan->status |= IEEE80211_BPARSE_BINTVAL_INVALID;
707 	}
708 	if (scan->country != NULL) {
709 		/*
710 		 * Validate we have at least enough data to extract
711 		 * the country code.  Not sure if we should return an
712 		 * error instead of discarding the IE; consider this
713 		 * being lenient as we don't depend on the data for
714 		 * correct operation.
715 		 */
716 		IEEE80211_VERIFY_LENGTH(scan->country[1], 3 * sizeof(uint8_t),
717 		    scan->country = NULL);
718 	}
719 	/*
720 	 * Process HT ie's.  This is complicated by our
721 	 * accepting both the standard ie's and the pre-draft
722 	 * vendor OUI ie's that some vendors still use/require.
723 	 */
724 	if (scan->htcap != NULL) {
725 		IEEE80211_VERIFY_LENGTH(scan->htcap[1],
726 		     scan->htcap[0] == IEEE80211_ELEMID_VENDOR ?
727 			 4 + sizeof(struct ieee80211_ie_htcap)-2 :
728 			 sizeof(struct ieee80211_ie_htcap)-2,
729 		     scan->htcap = NULL);
730 	}
731 	if (scan->htinfo != NULL) {
732 		IEEE80211_VERIFY_LENGTH(scan->htinfo[1],
733 		     scan->htinfo[0] == IEEE80211_ELEMID_VENDOR ?
734 			 4 + sizeof(struct ieee80211_ie_htinfo)-2 :
735 			 sizeof(struct ieee80211_ie_htinfo)-2,
736 		     scan->htinfo = NULL);
737 	}
738 	return scan->status;
739 }
740 
741 /*
742  * Parse an Action frame.  Return 0 on success, non-zero on failure.
743  */
744 int
745 ieee80211_parse_action(struct ieee80211_node *ni, struct mbuf *m)
746 {
747 	struct ieee80211vap *vap = ni->ni_vap;
748 	const struct ieee80211_action *ia;
749 	struct ieee80211_frame *wh;
750 	uint8_t *frm, *efrm;
751 
752 	/*
753 	 * action frame format:
754 	 *	[1] category
755 	 *	[1] action
756 	 *	[tlv] parameters
757 	 */
758 	wh = mtod(m, struct ieee80211_frame *);
759 	frm = (u_int8_t *)&wh[1];
760 	efrm = mtod(m, u_int8_t *) + m->m_len;
761 	IEEE80211_VERIFY_LENGTH(efrm - frm,
762 		sizeof(struct ieee80211_action), return EINVAL);
763 	ia = (const struct ieee80211_action *) frm;
764 
765 	vap->iv_stats.is_rx_action++;
766 	IEEE80211_NODE_STAT(ni, rx_action);
767 
768 	/* verify frame payloads but defer processing */
769 	/* XXX maybe push this to method */
770 	switch (ia->ia_category) {
771 	case IEEE80211_ACTION_CAT_BA:
772 		switch (ia->ia_action) {
773 		case IEEE80211_ACTION_BA_ADDBA_REQUEST:
774 			IEEE80211_VERIFY_LENGTH(efrm - frm,
775 			    sizeof(struct ieee80211_action_ba_addbarequest),
776 			    return EINVAL);
777 			break;
778 		case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
779 			IEEE80211_VERIFY_LENGTH(efrm - frm,
780 			    sizeof(struct ieee80211_action_ba_addbaresponse),
781 			    return EINVAL);
782 			break;
783 		case IEEE80211_ACTION_BA_DELBA:
784 			IEEE80211_VERIFY_LENGTH(efrm - frm,
785 			    sizeof(struct ieee80211_action_ba_delba),
786 			    return EINVAL);
787 			break;
788 		}
789 		break;
790 	case IEEE80211_ACTION_CAT_HT:
791 		switch (ia->ia_action) {
792 		case IEEE80211_ACTION_HT_TXCHWIDTH:
793 			IEEE80211_VERIFY_LENGTH(efrm - frm,
794 			    sizeof(struct ieee80211_action_ht_txchwidth),
795 			    return EINVAL);
796 			break;
797 		case IEEE80211_ACTION_HT_MIMOPWRSAVE:
798 			IEEE80211_VERIFY_LENGTH(efrm - frm,
799 			    sizeof(struct ieee80211_action_ht_mimopowersave),
800 			    return EINVAL);
801 			break;
802 		}
803 		break;
804 	}
805 	return 0;
806 }
807 
808 #ifdef IEEE80211_DEBUG
809 /*
810  * Debugging support.
811  */
812 void
813 ieee80211_ssid_mismatch(struct ieee80211vap *vap, const char *tag,
814 	uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid)
815 {
816 	printf("[%s] discard %s frame, ssid mismatch: ",
817 		ether_sprintf(mac), tag);
818 	ieee80211_print_essid(ssid + 2, ssid[1]);
819 	printf("\n");
820 }
821 
822 /*
823  * Return the bssid of a frame.
824  */
825 static const uint8_t *
826 ieee80211_getbssid(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
827 {
828 	if (vap->iv_opmode == IEEE80211_M_STA)
829 		return wh->i_addr2;
830 	if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) != IEEE80211_FC1_DIR_NODS)
831 		return wh->i_addr1;
832 	if ((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
833 		return wh->i_addr1;
834 	return wh->i_addr3;
835 }
836 
837 #include <machine/stdarg.h>
838 
839 void
840 ieee80211_note(struct ieee80211vap *vap, const char *fmt, ...)
841 {
842 	char buf[128];		/* XXX */
843 	va_list ap;
844 
845 	va_start(ap, fmt);
846 	vsnprintf(buf, sizeof(buf), fmt, ap);
847 	va_end(ap);
848 
849 	if_printf(vap->iv_ifp, "%s", buf);	/* NB: no \n */
850 }
851 
852 void
853 ieee80211_note_frame(struct ieee80211vap *vap,
854 	const struct ieee80211_frame *wh,
855 	const char *fmt, ...)
856 {
857 	char buf[128];		/* XXX */
858 	va_list ap;
859 
860 	va_start(ap, fmt);
861 	vsnprintf(buf, sizeof(buf), fmt, ap);
862 	va_end(ap);
863 	if_printf(vap->iv_ifp, "[%s] %s\n",
864 		ether_sprintf(ieee80211_getbssid(vap, wh)), buf);
865 }
866 
867 void
868 ieee80211_note_mac(struct ieee80211vap *vap,
869 	const uint8_t mac[IEEE80211_ADDR_LEN],
870 	const char *fmt, ...)
871 {
872 	char buf[128];		/* XXX */
873 	va_list ap;
874 
875 	va_start(ap, fmt);
876 	vsnprintf(buf, sizeof(buf), fmt, ap);
877 	va_end(ap);
878 	if_printf(vap->iv_ifp, "[%s] %s\n", ether_sprintf(mac), buf);
879 }
880 
881 void
882 ieee80211_discard_frame(struct ieee80211vap *vap,
883 	const struct ieee80211_frame *wh,
884 	const char *type, const char *fmt, ...)
885 {
886 	va_list ap;
887 
888 	if_printf(vap->iv_ifp, "[%s] discard ",
889 		ether_sprintf(ieee80211_getbssid(vap, wh)));
890 	if (type == NULL) {
891 		printf("%s frame, ", ieee80211_mgt_subtype_name[
892 			(wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) >>
893 			IEEE80211_FC0_SUBTYPE_SHIFT]);
894 	} else
895 		printf("%s frame, ", type);
896 	va_start(ap, fmt);
897 	vprintf(fmt, ap);
898 	va_end(ap);
899 	printf("\n");
900 }
901 
902 void
903 ieee80211_discard_ie(struct ieee80211vap *vap,
904 	const struct ieee80211_frame *wh,
905 	const char *type, const char *fmt, ...)
906 {
907 	va_list ap;
908 
909 	if_printf(vap->iv_ifp, "[%s] discard ",
910 		ether_sprintf(ieee80211_getbssid(vap, wh)));
911 	if (type != NULL)
912 		printf("%s information element, ", type);
913 	else
914 		printf("information element, ");
915 	va_start(ap, fmt);
916 	vprintf(fmt, ap);
917 	va_end(ap);
918 	printf("\n");
919 }
920 
921 void
922 ieee80211_discard_mac(struct ieee80211vap *vap,
923 	const uint8_t mac[IEEE80211_ADDR_LEN],
924 	const char *type, const char *fmt, ...)
925 {
926 	va_list ap;
927 
928 	if_printf(vap->iv_ifp, "[%s] discard ", ether_sprintf(mac));
929 	if (type != NULL)
930 		printf("%s frame, ", type);
931 	else
932 		printf("frame, ");
933 	va_start(ap, fmt);
934 	vprintf(fmt, ap);
935 	va_end(ap);
936 	printf("\n");
937 }
938 #endif /* IEEE80211_DEBUG */
939