xref: /freebsd/sys/net80211/ieee80211_output.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002-2007 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_inet.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/mbuf.h>
35 #include <sys/kernel.h>
36 #include <sys/endian.h>
37 
38 #include <sys/socket.h>
39 
40 #include <net/bpf.h>
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_regdomain.h>
49 
50 #ifdef INET
51 #include <netinet/in.h>
52 #include <netinet/if_ether.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #endif
56 
57 #define	ETHER_HEADER_COPY(dst, src) \
58 	memcpy(dst, src, sizeof(struct ether_header))
59 
60 static struct mbuf *ieee80211_encap_fastframe(struct ieee80211com *ic,
61 	struct mbuf *m1, const struct ether_header *eh1,
62 	struct mbuf *m2, const struct ether_header *eh2);
63 static int ieee80211_fragment(struct ieee80211com *, struct mbuf *,
64 	u_int hdrsize, u_int ciphdrsize, u_int mtu);
65 static	void ieee80211_tx_mgt_cb(struct ieee80211_node *, void *, int);
66 
67 #ifdef IEEE80211_DEBUG
68 /*
69  * Decide if an outbound management frame should be
70  * printed when debugging is enabled.  This filters some
71  * of the less interesting frames that come frequently
72  * (e.g. beacons).
73  */
74 static __inline int
75 doprint(struct ieee80211com *ic, int subtype)
76 {
77 	switch (subtype) {
78 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
79 		return (ic->ic_opmode == IEEE80211_M_IBSS);
80 	}
81 	return 1;
82 }
83 #endif
84 
85 /*
86  * Set the direction field and address fields of an outgoing
87  * non-QoS frame.  Note this should be called early on in
88  * constructing a frame as it sets i_fc[1]; other bits can
89  * then be or'd in.
90  */
91 static void
92 ieee80211_send_setup(struct ieee80211com *ic,
93 	struct ieee80211_node *ni,
94 	struct ieee80211_frame *wh,
95 	int type,
96 	const uint8_t sa[IEEE80211_ADDR_LEN],
97 	const uint8_t da[IEEE80211_ADDR_LEN],
98 	const uint8_t bssid[IEEE80211_ADDR_LEN])
99 {
100 #define	WH4(wh)	((struct ieee80211_frame_addr4 *)wh)
101 
102 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | type;
103 	if ((type & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_DATA) {
104 		switch (ic->ic_opmode) {
105 		case IEEE80211_M_STA:
106 			wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
107 			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
108 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
109 			IEEE80211_ADDR_COPY(wh->i_addr3, da);
110 			break;
111 		case IEEE80211_M_IBSS:
112 		case IEEE80211_M_AHDEMO:
113 			wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
114 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
115 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
116 			IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
117 			break;
118 		case IEEE80211_M_HOSTAP:
119 			wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
120 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
121 			IEEE80211_ADDR_COPY(wh->i_addr2, bssid);
122 			IEEE80211_ADDR_COPY(wh->i_addr3, sa);
123 			break;
124 		case IEEE80211_M_WDS:
125 			wh->i_fc[1] = IEEE80211_FC1_DIR_DSTODS;
126 			/* XXX cheat, bssid holds RA */
127 			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
128 			IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
129 			IEEE80211_ADDR_COPY(wh->i_addr3, da);
130 			IEEE80211_ADDR_COPY(WH4(wh)->i_addr4, sa);
131 			break;
132 		case IEEE80211_M_MONITOR:	/* NB: to quiet compiler */
133 			break;
134 		}
135 	} else {
136 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
137 		IEEE80211_ADDR_COPY(wh->i_addr1, da);
138 		IEEE80211_ADDR_COPY(wh->i_addr2, sa);
139 		IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
140 	}
141 	*(uint16_t *)&wh->i_dur[0] = 0;
142 	/* NB: use non-QoS tid */
143 	*(uint16_t *)&wh->i_seq[0] =
144 	    htole16(ni->ni_txseqs[IEEE80211_NONQOS_TID] << IEEE80211_SEQ_SEQ_SHIFT);
145 	ni->ni_txseqs[IEEE80211_NONQOS_TID]++;
146 #undef WH4
147 }
148 
149 /*
150  * Send a management frame to the specified node.  The node pointer
151  * must have a reference as the pointer will be passed to the driver
152  * and potentially held for a long time.  If the frame is successfully
153  * dispatched to the driver, then it is responsible for freeing the
154  * reference (and potentially free'ing up any associated storage).
155  */
156 int
157 ieee80211_mgmt_output(struct ieee80211com *ic, struct ieee80211_node *ni,
158     struct mbuf *m, int type)
159 {
160 	struct ifnet *ifp = ic->ic_ifp;
161 	struct ieee80211_frame *wh;
162 
163 	KASSERT(ni != NULL, ("null node"));
164 
165 	/*
166 	 * Yech, hack alert!  We want to pass the node down to the
167 	 * driver's start routine.  If we don't do so then the start
168 	 * routine must immediately look it up again and that can
169 	 * cause a lock order reversal if, for example, this frame
170 	 * is being sent because the station is being timedout and
171 	 * the frame being sent is a DEAUTH message.  We could stick
172 	 * this in an m_tag and tack that on to the mbuf.  However
173 	 * that's rather expensive to do for every frame so instead
174 	 * we stuff it in the rcvif field since outbound frames do
175 	 * not (presently) use this.
176 	 */
177 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
178 	if (m == NULL)
179 		return ENOMEM;
180 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
181 	m->m_pkthdr.rcvif = (void *)ni;
182 
183 	wh = mtod(m, struct ieee80211_frame *);
184 	ieee80211_send_setup(ic, ni, wh,
185 		IEEE80211_FC0_TYPE_MGT | type,
186 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
187 	if ((m->m_flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
188 		m->m_flags &= ~M_LINK0;
189 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
190 			"[%s] encrypting frame (%s)\n",
191 			ether_sprintf(wh->i_addr1), __func__);
192 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
193 	}
194 	if (ni->ni_flags & IEEE80211_NODE_QOS) {
195 		/* NB: force all management frames to the highest queue */
196 		M_WME_SETAC(m, WME_AC_VO);
197 	} else
198 		M_WME_SETAC(m, WME_AC_BE);
199 #ifdef IEEE80211_DEBUG
200 	/* avoid printing too many frames */
201 	if ((ieee80211_msg_debug(ic) && doprint(ic, type)) ||
202 	    ieee80211_msg_dumppkts(ic)) {
203 		printf("[%s] send %s on channel %u\n",
204 		    ether_sprintf(wh->i_addr1),
205 		    ieee80211_mgt_subtype_name[
206 			(type & IEEE80211_FC0_SUBTYPE_MASK) >>
207 				IEEE80211_FC0_SUBTYPE_SHIFT],
208 		    ieee80211_chan2ieee(ic, ic->ic_curchan));
209 	}
210 #endif
211 	IEEE80211_NODE_STAT(ni, tx_mgmt);
212 	IF_ENQUEUE(&ic->ic_mgtq, m);
213 	if_start(ifp);
214 	ifp->if_opackets++;
215 
216 	return 0;
217 }
218 
219 /*
220  * Raw packet transmit stub for legacy drivers.
221  * Send the packet through the mgt q so we bypass
222  * the normal encapsulation work.
223  */
224 int
225 ieee80211_raw_xmit(struct ieee80211_node *ni, struct mbuf *m,
226 	const struct ieee80211_bpf_params *params)
227 {
228 	struct ieee80211com *ic = ni->ni_ic;
229 	struct ifnet *ifp = ic->ic_ifp;
230 
231 	m->m_pkthdr.rcvif = (void *) ni;
232 	IF_ENQUEUE(&ic->ic_mgtq, m);
233 	if_start(ifp);
234 	ifp->if_opackets++;
235 
236 	return 0;
237 }
238 
239 /*
240  * 802.11 output routine. This is (currently) used only to
241  * connect bpf write calls to the 802.11 layer for injecting
242  * raw 802.11 frames.  Note we locate the ieee80211com from
243  * the ifnet using a spare field setup at attach time.  This
244  * will go away when the virtual ap support comes in.
245  */
246 int
247 ieee80211_output(struct ifnet *ifp, struct mbuf *m,
248 	struct sockaddr *dst, struct rtentry *rt0)
249 {
250 #define senderr(e) do { error = (e); goto bad;} while (0)
251 	struct ieee80211com *ic = ifp->if_llsoftc;	/* XXX */
252 	struct ieee80211_node *ni = NULL;
253 	struct ieee80211_frame *wh;
254 	int error;
255 
256 	/*
257 	 * Hand to the 802.3 code if not tagged as
258 	 * a raw 802.11 frame.
259 	 */
260 	if (dst->sa_family != AF_IEEE80211)
261 		return ether_output(ifp, m, dst, rt0);
262 #ifdef MAC
263 	error = mac_check_ifnet_transmit(ifp, m);
264 	if (error)
265 		senderr(error);
266 #endif
267 	if (ifp->if_flags & IFF_MONITOR)
268 		senderr(ENETDOWN);
269 	if ((ifp->if_flags & IFF_UP) == 0)
270 		senderr(ENETDOWN);
271 
272 	/* XXX bypass bridge, pfil, carp, etc. */
273 
274 	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_ack))
275 		senderr(EIO);	/* XXX */
276 	wh = mtod(m, struct ieee80211_frame *);
277 	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
278 	    IEEE80211_FC0_VERSION_0)
279 		senderr(EIO);	/* XXX */
280 
281 	/* locate destination node */
282 	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
283 	case IEEE80211_FC1_DIR_NODS:
284 	case IEEE80211_FC1_DIR_FROMDS:
285 		ni = ieee80211_find_txnode(ic, wh->i_addr1);
286 		break;
287 	case IEEE80211_FC1_DIR_TODS:
288 	case IEEE80211_FC1_DIR_DSTODS:
289 		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame))
290 			senderr(EIO);	/* XXX */
291 		ni = ieee80211_find_txnode(ic, wh->i_addr3);
292 		break;
293 	default:
294 		senderr(EIO);	/* XXX */
295 	}
296 	if (ni == NULL) {
297 		/*
298 		 * Permit packets w/ bpf params through regardless
299 		 * (see below about sa_len).
300 		 */
301 		if (dst->sa_len == 0)
302 			senderr(EHOSTUNREACH);
303 		ni = ieee80211_ref_node(ic->ic_bss);
304 	}
305 
306 	/* XXX ctrl frames should go through */
307 	if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) &&
308 	    (m->m_flags & M_PWR_SAV) == 0) {
309 		/*
310 		 * Station in power save mode; pass the frame
311 		 * to the 802.11 layer and continue.  We'll get
312 		 * the frame back when the time is right.
313 		 */
314 		ieee80211_pwrsave(ni, m);
315 		error = 0;
316 		goto reclaim;
317 	}
318 
319 	/* calculate priority so drivers can find the tx queue */
320 	/* XXX assumes an 802.3 frame */
321 	if (ieee80211_classify(ic, m, ni))
322 		senderr(EIO);		/* XXX */
323 
324 	BPF_MTAP(ifp, m);
325 	/*
326 	 * NB: DLT_IEEE802_11_RADIO identifies the parameters are
327 	 * present by setting the sa_len field of the sockaddr (yes,
328 	 * this is a hack).
329 	 * NB: we assume sa_data is suitably aligned to cast.
330 	 */
331 	return ic->ic_raw_xmit(ni, m, (const struct ieee80211_bpf_params *)
332 		(dst->sa_len ? dst->sa_data : NULL));
333 bad:
334 	if (m != NULL)
335 		m_freem(m);
336 reclaim:
337 	if (ni != NULL)
338 		ieee80211_free_node(ni);
339 	return error;
340 #undef senderr
341 }
342 
343 /*
344  * Send a null data frame to the specified node.
345  *
346  * NB: the caller is assumed to have setup a node reference
347  *     for use; this is necessary to deal with a race condition
348  *     when probing for inactive stations.
349  */
350 int
351 ieee80211_send_nulldata(struct ieee80211_node *ni)
352 {
353 	struct ieee80211com *ic = ni->ni_ic;
354 	struct ifnet *ifp = ic->ic_ifp;
355 	struct mbuf *m;
356 	struct ieee80211_frame *wh;
357 
358 	MGETHDR(m, M_NOWAIT, MT_DATA);
359 	if (m == NULL) {
360 		/* XXX debug msg */
361 		ieee80211_unref_node(&ni);
362 		ic->ic_stats.is_tx_nobuf++;
363 		return ENOMEM;
364 	}
365 	MH_ALIGN(m, sizeof(struct ieee80211_frame));
366 	m->m_pkthdr.rcvif = (void *) ni;
367 
368 	wh = mtod(m, struct ieee80211_frame *);
369 	ieee80211_send_setup(ic, ni, wh,
370 		IEEE80211_FC0_TYPE_DATA | IEEE80211_FC0_SUBTYPE_NODATA,
371 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
372 	/* NB: power management bit is never sent by an AP */
373 	if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) &&
374 	    ic->ic_opmode != IEEE80211_M_HOSTAP &&
375 	    ic->ic_opmode != IEEE80211_M_WDS)
376 		wh->i_fc[1] |= IEEE80211_FC1_PWR_MGT;
377 	m->m_len = m->m_pkthdr.len = sizeof(struct ieee80211_frame);
378 	M_WME_SETAC(m, WME_AC_BE);
379 
380 	IEEE80211_NODE_STAT(ni, tx_data);
381 
382 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
383 	    "[%s] send null data frame on channel %u, pwr mgt %s\n",
384 	    ether_sprintf(ni->ni_macaddr),
385 	    ieee80211_chan2ieee(ic, ic->ic_curchan),
386 	    wh->i_fc[1] & IEEE80211_FC1_PWR_MGT ? "ena" : "dis");
387 
388 	IF_ENQUEUE(&ic->ic_mgtq, m);		/* cheat */
389 	if_start(ifp);
390 
391 	return 0;
392 }
393 
394 /*
395  * Assign priority to a frame based on any vlan tag assigned
396  * to the station and/or any Diffserv setting in an IP header.
397  * Finally, if an ACM policy is setup (in station mode) it's
398  * applied.
399  */
400 int
401 ieee80211_classify(struct ieee80211com *ic, struct mbuf *m, struct ieee80211_node *ni)
402 {
403 	int v_wme_ac, d_wme_ac, ac;
404 #ifdef INET
405 	struct ether_header *eh;
406 #endif
407 
408 	if ((ni->ni_flags & IEEE80211_NODE_QOS) == 0) {
409 		ac = WME_AC_BE;
410 		goto done;
411 	}
412 
413 	/*
414 	 * If node has a vlan tag then all traffic
415 	 * to it must have a matching tag.
416 	 */
417 	v_wme_ac = 0;
418 	if (ni->ni_vlan != 0) {
419 		 if ((m->m_flags & M_VLANTAG) == 0) {
420 			IEEE80211_NODE_STAT(ni, tx_novlantag);
421 			return 1;
422 		}
423 		if (EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) !=
424 		    EVL_VLANOFTAG(ni->ni_vlan)) {
425 			IEEE80211_NODE_STAT(ni, tx_vlanmismatch);
426 			return 1;
427 		}
428 		/* map vlan priority to AC */
429 		v_wme_ac = TID_TO_WME_AC(EVL_PRIOFTAG(ni->ni_vlan));
430 	}
431 
432 #ifdef INET
433 	eh = mtod(m, struct ether_header *);
434 	if (eh->ether_type == htons(ETHERTYPE_IP)) {
435 		uint8_t tos;
436 		/*
437 		 * IP frame, map the DSCP bits from the TOS field.
438 		 */
439 		/* XXX m_copydata may be too slow for fast path */
440 		/* NB: ip header may not be in first mbuf */
441 		m_copydata(m, sizeof(struct ether_header) +
442 		    offsetof(struct ip, ip_tos), sizeof(tos), &tos);
443 		tos >>= 5;		/* NB: ECN + low 3 bits of DSCP */
444 		d_wme_ac = TID_TO_WME_AC(tos);
445 	} else {
446 #endif /* INET */
447 		d_wme_ac = WME_AC_BE;
448 #ifdef INET
449 	}
450 #endif
451 	/*
452 	 * Use highest priority AC.
453 	 */
454 	if (v_wme_ac > d_wme_ac)
455 		ac = v_wme_ac;
456 	else
457 		ac = d_wme_ac;
458 
459 	/*
460 	 * Apply ACM policy.
461 	 */
462 	if (ic->ic_opmode == IEEE80211_M_STA) {
463 		static const int acmap[4] = {
464 			WME_AC_BK,	/* WME_AC_BE */
465 			WME_AC_BK,	/* WME_AC_BK */
466 			WME_AC_BE,	/* WME_AC_VI */
467 			WME_AC_VI,	/* WME_AC_VO */
468 		};
469 		while (ac != WME_AC_BK &&
470 		    ic->ic_wme.wme_wmeBssChanParams.cap_wmeParams[ac].wmep_acm)
471 			ac = acmap[ac];
472 	}
473 done:
474 	M_WME_SETAC(m, ac);
475 	return 0;
476 }
477 
478 /*
479  * Insure there is sufficient contiguous space to encapsulate the
480  * 802.11 data frame.  If room isn't already there, arrange for it.
481  * Drivers and cipher modules assume we have done the necessary work
482  * and fail rudely if they don't find the space they need.
483  */
484 static struct mbuf *
485 ieee80211_mbuf_adjust(struct ieee80211com *ic, int hdrsize,
486 	struct ieee80211_key *key, struct mbuf *m)
487 {
488 #define	TO_BE_RECLAIMED	(sizeof(struct ether_header) - sizeof(struct llc))
489 	int needed_space = ic->ic_headroom + hdrsize;
490 
491 	if (key != NULL) {
492 		/* XXX belongs in crypto code? */
493 		needed_space += key->wk_cipher->ic_header;
494 		/* XXX frags */
495 		/*
496 		 * When crypto is being done in the host we must insure
497 		 * the data are writable for the cipher routines; clone
498 		 * a writable mbuf chain.
499 		 * XXX handle SWMIC specially
500 		 */
501 		if (key->wk_flags & (IEEE80211_KEY_SWCRYPT|IEEE80211_KEY_SWMIC)) {
502 			m = m_unshare(m, M_NOWAIT);
503 			if (m == NULL) {
504 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
505 				    "%s: cannot get writable mbuf\n", __func__);
506 				ic->ic_stats.is_tx_nobuf++; /* XXX new stat */
507 				return NULL;
508 			}
509 		}
510 	}
511 	/*
512 	 * We know we are called just before stripping an Ethernet
513 	 * header and prepending an LLC header.  This means we know
514 	 * there will be
515 	 *	sizeof(struct ether_header) - sizeof(struct llc)
516 	 * bytes recovered to which we need additional space for the
517 	 * 802.11 header and any crypto header.
518 	 */
519 	/* XXX check trailing space and copy instead? */
520 	if (M_LEADINGSPACE(m) < needed_space - TO_BE_RECLAIMED) {
521 		struct mbuf *n = m_gethdr(M_NOWAIT, m->m_type);
522 		if (n == NULL) {
523 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
524 			    "%s: cannot expand storage\n", __func__);
525 			ic->ic_stats.is_tx_nobuf++;
526 			m_freem(m);
527 			return NULL;
528 		}
529 		KASSERT(needed_space <= MHLEN,
530 		    ("not enough room, need %u got %zu\n", needed_space, MHLEN));
531 		/*
532 		 * Setup new mbuf to have leading space to prepend the
533 		 * 802.11 header and any crypto header bits that are
534 		 * required (the latter are added when the driver calls
535 		 * back to ieee80211_crypto_encap to do crypto encapsulation).
536 		 */
537 		/* NB: must be first 'cuz it clobbers m_data */
538 		m_move_pkthdr(n, m);
539 		n->m_len = 0;			/* NB: m_gethdr does not set */
540 		n->m_data += needed_space;
541 		/*
542 		 * Pull up Ethernet header to create the expected layout.
543 		 * We could use m_pullup but that's overkill (i.e. we don't
544 		 * need the actual data) and it cannot fail so do it inline
545 		 * for speed.
546 		 */
547 		/* NB: struct ether_header is known to be contiguous */
548 		n->m_len += sizeof(struct ether_header);
549 		m->m_len -= sizeof(struct ether_header);
550 		m->m_data += sizeof(struct ether_header);
551 		/*
552 		 * Replace the head of the chain.
553 		 */
554 		n->m_next = m;
555 		m = n;
556 	}
557 	return m;
558 #undef TO_BE_RECLAIMED
559 }
560 
561 /*
562  * Return the transmit key to use in sending a unicast frame.
563  * If a unicast key is set we use that.  When no unicast key is set
564  * we fall back to the default transmit key.
565  */
566 static __inline struct ieee80211_key *
567 ieee80211_crypto_getucastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
568 {
569 	if (IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
570 		if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
571 		    IEEE80211_KEY_UNDEFINED(&ic->ic_nw_keys[ic->ic_def_txkey]))
572 			return NULL;
573 		return &ic->ic_nw_keys[ic->ic_def_txkey];
574 	} else {
575 		return &ni->ni_ucastkey;
576 	}
577 }
578 
579 /*
580  * Return the transmit key to use in sending a multicast frame.
581  * Multicast traffic always uses the group key which is installed as
582  * the default tx key.
583  */
584 static __inline struct ieee80211_key *
585 ieee80211_crypto_getmcastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
586 {
587 	if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
588 	    IEEE80211_KEY_UNDEFINED(&ic->ic_nw_keys[ic->ic_def_txkey]))
589 		return NULL;
590 	return &ic->ic_nw_keys[ic->ic_def_txkey];
591 }
592 
593 /*
594  * Encapsulate an outbound data frame.  The mbuf chain is updated.
595  * If an error is encountered NULL is returned.  The caller is required
596  * to provide a node reference and pullup the ethernet header in the
597  * first mbuf.
598  */
599 struct mbuf *
600 ieee80211_encap(struct ieee80211com *ic, struct mbuf *m,
601 	struct ieee80211_node *ni)
602 {
603 	struct ether_header eh;
604 	struct ieee80211_frame *wh;
605 	struct ieee80211_key *key;
606 	struct llc *llc;
607 	int hdrsize, datalen, addqos, txfrag, isff;
608 
609 	/*
610 	 * Copy existing Ethernet header to a safe place.  The
611 	 * rest of the code assumes it's ok to strip it when
612 	 * reorganizing state for the final encapsulation.
613 	 */
614 	KASSERT(m->m_len >= sizeof(eh), ("no ethernet header!"));
615 	memcpy(&eh, mtod(m, caddr_t), sizeof(struct ether_header));
616 
617 	/*
618 	 * Insure space for additional headers.  First identify
619 	 * transmit key to use in calculating any buffer adjustments
620 	 * required.  This is also used below to do privacy
621 	 * encapsulation work.  Then calculate the 802.11 header
622 	 * size and any padding required by the driver.
623 	 *
624 	 * Note key may be NULL if we fall back to the default
625 	 * transmit key and that is not set.  In that case the
626 	 * buffer may not be expanded as needed by the cipher
627 	 * routines, but they will/should discard it.
628 	 */
629 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
630 		if (ic->ic_opmode == IEEE80211_M_STA ||
631 		    !IEEE80211_IS_MULTICAST(eh.ether_dhost))
632 			key = ieee80211_crypto_getucastkey(ic, ni);
633 		else
634 			key = ieee80211_crypto_getmcastkey(ic, ni);
635 		if (key == NULL && eh.ether_type != htons(ETHERTYPE_PAE)) {
636 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
637 			    "[%s] no default transmit key (%s) deftxkey %u\n",
638 			    ether_sprintf(eh.ether_dhost), __func__,
639 			    ic->ic_def_txkey);
640 			ic->ic_stats.is_tx_nodefkey++;
641 			goto bad;
642 		}
643 	} else
644 		key = NULL;
645 	/* XXX 4-address format */
646 	/*
647 	 * XXX Some ap's don't handle QoS-encapsulated EAPOL
648 	 * frames so suppress use.  This may be an issue if other
649 	 * ap's require all data frames to be QoS-encapsulated
650 	 * once negotiated in which case we'll need to make this
651 	 * configurable.
652 	 */
653 	addqos = (ni->ni_flags & (IEEE80211_NODE_QOS|IEEE80211_NODE_HT)) &&
654 		 eh.ether_type != htons(ETHERTYPE_PAE);
655 	if (addqos)
656 		hdrsize = sizeof(struct ieee80211_qosframe);
657 	else
658 		hdrsize = sizeof(struct ieee80211_frame);
659 	if (ic->ic_flags & IEEE80211_F_DATAPAD)
660 		hdrsize = roundup(hdrsize, sizeof(uint32_t));
661 
662 	if ((isff = m->m_flags & M_FF) != 0) {
663 		struct mbuf *m2;
664 		struct ether_header eh2;
665 
666 		/*
667 		 * Fast frame encapsulation.  There must be two packets
668 		 * chained with m_nextpkt.  We do header adjustment for
669 		 * each, add the tunnel encapsulation, and then concatenate
670 		 * the mbuf chains to form a single frame for transmission.
671 		 */
672 		m2 = m->m_nextpkt;
673 		if (m2 == NULL) {
674 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
675 				"%s: only one frame\n", __func__);
676 			goto bad;
677 		}
678 		m->m_nextpkt = NULL;
679 		/*
680 		 * Include fast frame headers in adjusting header
681 		 * layout; this allocates space according to what
682 		 * ieee80211_encap_fastframe will do.
683 		 */
684 		m = ieee80211_mbuf_adjust(ic,
685 			hdrsize + sizeof(struct llc) + sizeof(uint32_t) + 2 +
686 			    sizeof(struct ether_header),
687 			key, m);
688 		if (m == NULL) {
689 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
690 			m_freem(m2);
691 			goto bad;
692 		}
693 		/*
694 		 * Copy second frame's Ethernet header out of line
695 		 * and adjust for encapsulation headers.  Note that
696 		 * we make room for padding in case there isn't room
697 		 * at the end of first frame.
698 		 */
699 		KASSERT(m2->m_len >= sizeof(eh2), ("no ethernet header!"));
700 		memcpy(&eh2, mtod(m2, caddr_t), sizeof(struct ether_header));
701 		m2 = ieee80211_mbuf_adjust(ic,
702 			ATH_FF_MAX_HDR_PAD + sizeof(struct ether_header),
703 			NULL, m2);
704 		if (m2 == NULL) {
705 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
706 			goto bad;
707 		}
708 		m = ieee80211_encap_fastframe(ic, m, &eh, m2, &eh2);
709 		if (m == NULL)
710 			goto bad;
711 	} else {
712 		/*
713 		 * Normal frame.
714 		 */
715 		m = ieee80211_mbuf_adjust(ic, hdrsize, key, m);
716 		if (m == NULL) {
717 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
718 			goto bad;
719 		}
720 		/* NB: this could be optimized 'cuz of ieee80211_mbuf_adjust */
721 		m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
722 		llc = mtod(m, struct llc *);
723 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
724 		llc->llc_control = LLC_UI;
725 		llc->llc_snap.org_code[0] = 0;
726 		llc->llc_snap.org_code[1] = 0;
727 		llc->llc_snap.org_code[2] = 0;
728 		llc->llc_snap.ether_type = eh.ether_type;
729 	}
730 	datalen = m->m_pkthdr.len;		/* NB: w/o 802.11 header */
731 
732 	M_PREPEND(m, hdrsize, M_DONTWAIT);
733 	if (m == NULL) {
734 		ic->ic_stats.is_tx_nobuf++;
735 		goto bad;
736 	}
737 	wh = mtod(m, struct ieee80211_frame *);
738 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
739 	*(uint16_t *)wh->i_dur = 0;
740 	switch (ic->ic_opmode) {
741 	case IEEE80211_M_STA:
742 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
743 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
744 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
745 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
746 		break;
747 	case IEEE80211_M_IBSS:
748 	case IEEE80211_M_AHDEMO:
749 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
750 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
751 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
752 		/*
753 		 * NB: always use the bssid from ic_bss as the
754 		 *     neighbor's may be stale after an ibss merge
755 		 */
756 		IEEE80211_ADDR_COPY(wh->i_addr3, ic->ic_bss->ni_bssid);
757 		break;
758 	case IEEE80211_M_HOSTAP:
759 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
760 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
761 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
762 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
763 		break;
764 	case IEEE80211_M_MONITOR:
765 	case IEEE80211_M_WDS:
766 		goto bad;
767 	}
768 	if (m->m_flags & M_MORE_DATA)
769 		wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
770 	if (addqos) {
771 		struct ieee80211_qosframe *qwh =
772 			(struct ieee80211_qosframe *) wh;
773 		int ac, tid;
774 
775 		ac = M_WME_GETAC(m);
776 		/* map from access class/queue to 11e header priorty value */
777 		tid = WME_AC_TO_TID(ac);
778 		qwh->i_qos[0] = tid & IEEE80211_QOS_TID;
779 		/*
780 		 * Check if A-MPDU tx aggregation is setup or if we
781 		 * should try to enable it.  The sta must be associated
782 		 * with HT and A-MPDU enabled for use.  On the first
783 		 * frame that goes out We issue an ADDBA request and
784 		 * wait for a reply.  The frame being encapsulated
785 		 * will go out w/o using A-MPDU, or possibly it might
786 		 * be collected by the driver and held/retransmit.
787 		 * ieee80211_ampdu_request handles staggering requests
788 		 * in case the receiver NAK's us or we are otherwise
789 		 * unable to establish a BA stream.
790 		 */
791 		if ((ni->ni_flags & IEEE80211_NODE_AMPDU_TX) &&
792 		    (ic->ic_flags_ext & IEEE80211_FEXT_AMPDU_TX)) {
793 			struct ieee80211_tx_ampdu *tap = &ni->ni_tx_ampdu[ac];
794 
795 			if (IEEE80211_AMPDU_RUNNING(tap)) {
796 				/*
797 				 * Operational, mark frame for aggregation.
798 				 */
799 				qwh->i_qos[0] |= IEEE80211_QOS_ACKPOLICY_BA;
800 			} else if (!IEEE80211_AMPDU_REQUESTED(tap)) {
801 				/*
802 				 * Not negotiated yet, request service.
803 				 */
804 				ieee80211_ampdu_request(ni, tap);
805 			}
806 		}
807 		/* XXX works even when BA marked above */
808 		if (ic->ic_wme.wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy)
809 			qwh->i_qos[0] |= IEEE80211_QOS_ACKPOLICY_NOACK;
810 		qwh->i_qos[1] = 0;
811 		qwh->i_fc[0] |= IEEE80211_FC0_SUBTYPE_QOS;
812 
813 		*(uint16_t *)wh->i_seq =
814 		    htole16(ni->ni_txseqs[tid] << IEEE80211_SEQ_SEQ_SHIFT);
815 		ni->ni_txseqs[tid]++;
816 	} else {
817 		*(uint16_t *)wh->i_seq =
818 		    htole16(ni->ni_txseqs[IEEE80211_NONQOS_TID] << IEEE80211_SEQ_SEQ_SHIFT);
819 		ni->ni_txseqs[IEEE80211_NONQOS_TID]++;
820 	}
821 	/* check if xmit fragmentation is required */
822 	txfrag = (m->m_pkthdr.len > ic->ic_fragthreshold &&
823 	    !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
824 	    (ic->ic_caps & IEEE80211_C_TXFRAG) &&
825 	    !isff);		/* NB: don't fragment ff's */
826 	if (key != NULL) {
827 		/*
828 		 * IEEE 802.1X: send EAPOL frames always in the clear.
829 		 * WPA/WPA2: encrypt EAPOL keys when pairwise keys are set.
830 		 */
831 		if (eh.ether_type != htons(ETHERTYPE_PAE) ||
832 		    ((ic->ic_flags & IEEE80211_F_WPA) &&
833 		     (ic->ic_opmode == IEEE80211_M_STA ?
834 		      !IEEE80211_KEY_UNDEFINED(key) :
835 		      !IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)))) {
836 			wh->i_fc[1] |= IEEE80211_FC1_WEP;
837 			if (!ieee80211_crypto_enmic(ic, key, m, txfrag)) {
838 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
839 				    "[%s] enmic failed, discard frame\n",
840 				    ether_sprintf(eh.ether_dhost));
841 				ic->ic_stats.is_crypto_enmicfail++;
842 				goto bad;
843 			}
844 		}
845 	}
846 	/*
847 	 * NB: frag flags may leak from above; they should only
848 	 *     be set on return to the caller if we fragment at
849 	 *     the 802.11 layer.
850 	 */
851 	m->m_flags &= ~(M_FRAG | M_FIRSTFRAG);
852 	if (txfrag && !ieee80211_fragment(ic, m, hdrsize,
853 	    key != NULL ? key->wk_cipher->ic_header : 0, ic->ic_fragthreshold))
854 		goto bad;
855 
856 	IEEE80211_NODE_STAT(ni, tx_data);
857 	if (IEEE80211_IS_MULTICAST(wh->i_addr1))
858 		IEEE80211_NODE_STAT(ni, tx_mcast);
859 	else
860 		IEEE80211_NODE_STAT(ni, tx_ucast);
861 	IEEE80211_NODE_STAT_ADD(ni, tx_bytes, datalen);
862 
863 	return m;
864 bad:
865 	if (m != NULL)
866 		m_freem(m);
867 	return NULL;
868 }
869 
870 /*
871  * Do Ethernet-LLC encapsulation for each payload in a fast frame
872  * tunnel encapsulation.  The frame is assumed to have an Ethernet
873  * header at the front that must be stripped before prepending the
874  * LLC followed by the Ethernet header passed in (with an Ethernet
875  * type that specifies the payload size).
876  */
877 static struct mbuf *
878 ieee80211_encap1(struct ieee80211com *ic, struct mbuf *m,
879 	const struct ether_header *eh)
880 {
881 	struct llc *llc;
882 	uint16_t payload;
883 
884 	/* XXX optimize by combining m_adj+M_PREPEND */
885 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
886 	llc = mtod(m, struct llc *);
887 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
888 	llc->llc_control = LLC_UI;
889 	llc->llc_snap.org_code[0] = 0;
890 	llc->llc_snap.org_code[1] = 0;
891 	llc->llc_snap.org_code[2] = 0;
892 	llc->llc_snap.ether_type = eh->ether_type;
893 	payload = m->m_pkthdr.len;		/* NB: w/o Ethernet header */
894 
895 	M_PREPEND(m, sizeof(struct ether_header), M_DONTWAIT);
896 	if (m == NULL) {		/* XXX cannot happen */
897 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
898 			"%s: no space for ether_header\n", __func__);
899 		ic->ic_stats.is_tx_nobuf++;
900 		return NULL;
901 	}
902 	ETHER_HEADER_COPY(mtod(m, void *), eh);
903 	mtod(m, struct ether_header *)->ether_type = htons(payload);
904 	return m;
905 }
906 
907 /*
908  * Do fast frame tunnel encapsulation.  The two frames and
909  * Ethernet headers are supplied.  The caller is assumed to
910  * have arrange for space in the mbuf chains for encapsulating
911  * headers (to avoid major mbuf fragmentation).
912  *
913  * The encapsulated frame is returned or NULL if there is a
914  * problem (should not happen).
915  */
916 static struct mbuf *
917 ieee80211_encap_fastframe(struct ieee80211com *ic,
918 	struct mbuf *m1, const struct ether_header *eh1,
919 	struct mbuf *m2, const struct ether_header *eh2)
920 {
921 	struct llc *llc;
922 	struct mbuf *m;
923 	int pad;
924 
925 	/*
926 	 * First, each frame gets a standard encapsulation.
927 	 */
928 	m1 = ieee80211_encap1(ic, m1, eh1);
929 	if (m1 == NULL) {
930 		m_freem(m2);
931 		return NULL;
932 	}
933 	m2 = ieee80211_encap1(ic, m2, eh2);
934 	if (m2 == NULL) {
935 		m_freem(m1);
936 		return NULL;
937 	}
938 
939 	/*
940 	 * Pad leading frame to a 4-byte boundary.  If there
941 	 * is space at the end of the first frame, put it
942 	 * there; otherwise prepend to the front of the second
943 	 * frame.  We know doing the second will always work
944 	 * because we reserve space above.  We prefer appending
945 	 * as this typically has better DMA alignment properties.
946 	 */
947 	for (m = m1; m->m_next != NULL; m = m->m_next)
948 		;
949 	pad = roundup2(m1->m_pkthdr.len, 4) - m1->m_pkthdr.len;
950 	if (pad) {
951 		if (M_TRAILINGSPACE(m) < pad) {		/* prepend to second */
952 			m2->m_data -= pad;
953 			m2->m_len += pad;
954 			m2->m_pkthdr.len += pad;
955 		} else {				/* append to first */
956 			m->m_len += pad;
957 			m1->m_pkthdr.len += pad;
958 		}
959 	}
960 
961 	/*
962 	 * Now, stick 'em together and prepend the tunnel headers;
963 	 * first the Atheros tunnel header (all zero for now) and
964 	 * then a special fast frame LLC.
965 	 *
966 	 * XXX optimize by prepending together
967 	 */
968 	m->m_next = m2;			/* NB: last mbuf from above */
969 	m1->m_pkthdr.len += m2->m_pkthdr.len;
970 	M_PREPEND(m1, sizeof(uint32_t)+2, M_DONTWAIT);
971 	if (m1 == NULL) {		/* XXX cannot happen */
972 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
973 			"%s: no space for tunnel header\n", __func__);
974 		ic->ic_stats.is_tx_nobuf++;
975 		return NULL;
976 	}
977 	memset(mtod(m1, void *), 0, sizeof(uint32_t)+2);
978 
979 	M_PREPEND(m1, sizeof(struct llc), M_DONTWAIT);
980 	if (m1 == NULL) {		/* XXX cannot happen */
981 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
982 			"%s: no space for llc header\n", __func__);
983 		ic->ic_stats.is_tx_nobuf++;
984 		return NULL;
985 	}
986 	llc = mtod(m1, struct llc *);
987 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
988 	llc->llc_control = LLC_UI;
989 	llc->llc_snap.org_code[0] = ATH_FF_SNAP_ORGCODE_0;
990 	llc->llc_snap.org_code[1] = ATH_FF_SNAP_ORGCODE_1;
991 	llc->llc_snap.org_code[2] = ATH_FF_SNAP_ORGCODE_2;
992 	llc->llc_snap.ether_type = htons(ATH_FF_ETH_TYPE);
993 
994 	ic->ic_stats.is_ff_encap++;
995 
996 	return m1;
997 }
998 
999 /*
1000  * Fragment the frame according to the specified mtu.
1001  * The size of the 802.11 header (w/o padding) is provided
1002  * so we don't need to recalculate it.  We create a new
1003  * mbuf for each fragment and chain it through m_nextpkt;
1004  * we might be able to optimize this by reusing the original
1005  * packet's mbufs but that is significantly more complicated.
1006  */
1007 static int
1008 ieee80211_fragment(struct ieee80211com *ic, struct mbuf *m0,
1009 	u_int hdrsize, u_int ciphdrsize, u_int mtu)
1010 {
1011 	struct ieee80211_frame *wh, *whf;
1012 	struct mbuf *m, *prev, *next;
1013 	u_int totalhdrsize, fragno, fragsize, off, remainder, payload;
1014 
1015 	KASSERT(m0->m_nextpkt == NULL, ("mbuf already chained?"));
1016 	KASSERT(m0->m_pkthdr.len > mtu,
1017 		("pktlen %u mtu %u", m0->m_pkthdr.len, mtu));
1018 
1019 	wh = mtod(m0, struct ieee80211_frame *);
1020 	/* NB: mark the first frag; it will be propagated below */
1021 	wh->i_fc[1] |= IEEE80211_FC1_MORE_FRAG;
1022 	totalhdrsize = hdrsize + ciphdrsize;
1023 	fragno = 1;
1024 	off = mtu - ciphdrsize;
1025 	remainder = m0->m_pkthdr.len - off;
1026 	prev = m0;
1027 	do {
1028 		fragsize = totalhdrsize + remainder;
1029 		if (fragsize > mtu)
1030 			fragsize = mtu;
1031 		KASSERT(fragsize < MCLBYTES,
1032 			("fragment size %u too big!", fragsize));
1033 		if (fragsize > MHLEN)
1034 			m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1035 		else
1036 			m = m_gethdr(M_DONTWAIT, MT_DATA);
1037 		if (m == NULL)
1038 			goto bad;
1039 		/* leave room to prepend any cipher header */
1040 		m_align(m, fragsize - ciphdrsize);
1041 
1042 		/*
1043 		 * Form the header in the fragment.  Note that since
1044 		 * we mark the first fragment with the MORE_FRAG bit
1045 		 * it automatically is propagated to each fragment; we
1046 		 * need only clear it on the last fragment (done below).
1047 		 */
1048 		whf = mtod(m, struct ieee80211_frame *);
1049 		memcpy(whf, wh, hdrsize);
1050 		*(uint16_t *)&whf->i_seq[0] |= htole16(
1051 			(fragno & IEEE80211_SEQ_FRAG_MASK) <<
1052 				IEEE80211_SEQ_FRAG_SHIFT);
1053 		fragno++;
1054 
1055 		payload = fragsize - totalhdrsize;
1056 		/* NB: destination is known to be contiguous */
1057 		m_copydata(m0, off, payload, mtod(m, uint8_t *) + hdrsize);
1058 		m->m_len = hdrsize + payload;
1059 		m->m_pkthdr.len = hdrsize + payload;
1060 		m->m_flags |= M_FRAG;
1061 
1062 		/* chain up the fragment */
1063 		prev->m_nextpkt = m;
1064 		prev = m;
1065 
1066 		/* deduct fragment just formed */
1067 		remainder -= payload;
1068 		off += payload;
1069 	} while (remainder != 0);
1070 	whf->i_fc[1] &= ~IEEE80211_FC1_MORE_FRAG;
1071 
1072 	/* strip first mbuf now that everything has been copied */
1073 	m_adj(m0, -(m0->m_pkthdr.len - (mtu - ciphdrsize)));
1074 	m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1075 
1076 	ic->ic_stats.is_tx_fragframes++;
1077 	ic->ic_stats.is_tx_frags += fragno-1;
1078 
1079 	return 1;
1080 bad:
1081 	/* reclaim fragments but leave original frame for caller to free */
1082 	for (m = m0->m_nextpkt; m != NULL; m = next) {
1083 		next = m->m_nextpkt;
1084 		m->m_nextpkt = NULL;		/* XXX paranoid */
1085 		m_freem(m);
1086 	}
1087 	m0->m_nextpkt = NULL;
1088 	return 0;
1089 }
1090 
1091 /*
1092  * Add a supported rates element id to a frame.
1093  */
1094 static uint8_t *
1095 ieee80211_add_rates(uint8_t *frm, const struct ieee80211_rateset *rs)
1096 {
1097 	int nrates;
1098 
1099 	*frm++ = IEEE80211_ELEMID_RATES;
1100 	nrates = rs->rs_nrates;
1101 	if (nrates > IEEE80211_RATE_SIZE)
1102 		nrates = IEEE80211_RATE_SIZE;
1103 	*frm++ = nrates;
1104 	memcpy(frm, rs->rs_rates, nrates);
1105 	return frm + nrates;
1106 }
1107 
1108 /*
1109  * Add an extended supported rates element id to a frame.
1110  */
1111 static uint8_t *
1112 ieee80211_add_xrates(uint8_t *frm, const struct ieee80211_rateset *rs)
1113 {
1114 	/*
1115 	 * Add an extended supported rates element if operating in 11g mode.
1116 	 */
1117 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
1118 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
1119 		*frm++ = IEEE80211_ELEMID_XRATES;
1120 		*frm++ = nrates;
1121 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
1122 		frm += nrates;
1123 	}
1124 	return frm;
1125 }
1126 
1127 /*
1128  * Add an ssid elemet to a frame.
1129  */
1130 static uint8_t *
1131 ieee80211_add_ssid(uint8_t *frm, const uint8_t *ssid, u_int len)
1132 {
1133 	*frm++ = IEEE80211_ELEMID_SSID;
1134 	*frm++ = len;
1135 	memcpy(frm, ssid, len);
1136 	return frm + len;
1137 }
1138 
1139 /*
1140  * Add an erp element to a frame.
1141  */
1142 static uint8_t *
1143 ieee80211_add_erp(uint8_t *frm, struct ieee80211com *ic)
1144 {
1145 	uint8_t erp;
1146 
1147 	*frm++ = IEEE80211_ELEMID_ERP;
1148 	*frm++ = 1;
1149 	erp = 0;
1150 	if (ic->ic_nonerpsta != 0)
1151 		erp |= IEEE80211_ERP_NON_ERP_PRESENT;
1152 	if (ic->ic_flags & IEEE80211_F_USEPROT)
1153 		erp |= IEEE80211_ERP_USE_PROTECTION;
1154 	if (ic->ic_flags & IEEE80211_F_USEBARKER)
1155 		erp |= IEEE80211_ERP_LONG_PREAMBLE;
1156 	*frm++ = erp;
1157 	return frm;
1158 }
1159 
1160 static uint8_t *
1161 ieee80211_setup_wpa_ie(struct ieee80211com *ic, uint8_t *ie)
1162 {
1163 #define	WPA_OUI_BYTES		0x00, 0x50, 0xf2
1164 #define	ADDSHORT(frm, v) do {			\
1165 	frm[0] = (v) & 0xff;			\
1166 	frm[1] = (v) >> 8;			\
1167 	frm += 2;				\
1168 } while (0)
1169 #define	ADDSELECTOR(frm, sel) do {		\
1170 	memcpy(frm, sel, 4);			\
1171 	frm += 4;				\
1172 } while (0)
1173 	static const uint8_t oui[4] = { WPA_OUI_BYTES, WPA_OUI_TYPE };
1174 	static const uint8_t cipher_suite[][4] = {
1175 		{ WPA_OUI_BYTES, WPA_CSE_WEP40 },	/* NB: 40-bit */
1176 		{ WPA_OUI_BYTES, WPA_CSE_TKIP },
1177 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX WRAP */
1178 		{ WPA_OUI_BYTES, WPA_CSE_CCMP },
1179 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1180 		{ WPA_OUI_BYTES, WPA_CSE_NULL },
1181 	};
1182 	static const uint8_t wep104_suite[4] =
1183 		{ WPA_OUI_BYTES, WPA_CSE_WEP104 };
1184 	static const uint8_t key_mgt_unspec[4] =
1185 		{ WPA_OUI_BYTES, WPA_ASE_8021X_UNSPEC };
1186 	static const uint8_t key_mgt_psk[4] =
1187 		{ WPA_OUI_BYTES, WPA_ASE_8021X_PSK };
1188 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1189 	uint8_t *frm = ie;
1190 	uint8_t *selcnt;
1191 
1192 	*frm++ = IEEE80211_ELEMID_VENDOR;
1193 	*frm++ = 0;				/* length filled in below */
1194 	memcpy(frm, oui, sizeof(oui));		/* WPA OUI */
1195 	frm += sizeof(oui);
1196 	ADDSHORT(frm, WPA_VERSION);
1197 
1198 	/* XXX filter out CKIP */
1199 
1200 	/* multicast cipher */
1201 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1202 	    rsn->rsn_mcastkeylen >= 13)
1203 		ADDSELECTOR(frm, wep104_suite);
1204 	else
1205 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1206 
1207 	/* unicast cipher list */
1208 	selcnt = frm;
1209 	ADDSHORT(frm, 0);			/* selector count */
1210 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1211 		selcnt[0]++;
1212 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1213 	}
1214 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1215 		selcnt[0]++;
1216 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1217 	}
1218 
1219 	/* authenticator selector list */
1220 	selcnt = frm;
1221 	ADDSHORT(frm, 0);			/* selector count */
1222 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1223 		selcnt[0]++;
1224 		ADDSELECTOR(frm, key_mgt_unspec);
1225 	}
1226 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1227 		selcnt[0]++;
1228 		ADDSELECTOR(frm, key_mgt_psk);
1229 	}
1230 
1231 	/* optional capabilities */
1232 	if (rsn->rsn_caps != 0 && rsn->rsn_caps != RSN_CAP_PREAUTH)
1233 		ADDSHORT(frm, rsn->rsn_caps);
1234 
1235 	/* calculate element length */
1236 	ie[1] = frm - ie - 2;
1237 	KASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1238 		("WPA IE too big, %u > %zu",
1239 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1240 	return frm;
1241 #undef ADDSHORT
1242 #undef ADDSELECTOR
1243 #undef WPA_OUI_BYTES
1244 }
1245 
1246 static uint8_t *
1247 ieee80211_setup_rsn_ie(struct ieee80211com *ic, uint8_t *ie)
1248 {
1249 #define	RSN_OUI_BYTES		0x00, 0x0f, 0xac
1250 #define	ADDSHORT(frm, v) do {			\
1251 	frm[0] = (v) & 0xff;			\
1252 	frm[1] = (v) >> 8;			\
1253 	frm += 2;				\
1254 } while (0)
1255 #define	ADDSELECTOR(frm, sel) do {		\
1256 	memcpy(frm, sel, 4);			\
1257 	frm += 4;				\
1258 } while (0)
1259 	static const uint8_t cipher_suite[][4] = {
1260 		{ RSN_OUI_BYTES, RSN_CSE_WEP40 },	/* NB: 40-bit */
1261 		{ RSN_OUI_BYTES, RSN_CSE_TKIP },
1262 		{ RSN_OUI_BYTES, RSN_CSE_WRAP },
1263 		{ RSN_OUI_BYTES, RSN_CSE_CCMP },
1264 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1265 		{ RSN_OUI_BYTES, RSN_CSE_NULL },
1266 	};
1267 	static const uint8_t wep104_suite[4] =
1268 		{ RSN_OUI_BYTES, RSN_CSE_WEP104 };
1269 	static const uint8_t key_mgt_unspec[4] =
1270 		{ RSN_OUI_BYTES, RSN_ASE_8021X_UNSPEC };
1271 	static const uint8_t key_mgt_psk[4] =
1272 		{ RSN_OUI_BYTES, RSN_ASE_8021X_PSK };
1273 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1274 	uint8_t *frm = ie;
1275 	uint8_t *selcnt;
1276 
1277 	*frm++ = IEEE80211_ELEMID_RSN;
1278 	*frm++ = 0;				/* length filled in below */
1279 	ADDSHORT(frm, RSN_VERSION);
1280 
1281 	/* XXX filter out CKIP */
1282 
1283 	/* multicast cipher */
1284 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1285 	    rsn->rsn_mcastkeylen >= 13)
1286 		ADDSELECTOR(frm, wep104_suite);
1287 	else
1288 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1289 
1290 	/* unicast cipher list */
1291 	selcnt = frm;
1292 	ADDSHORT(frm, 0);			/* selector count */
1293 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1294 		selcnt[0]++;
1295 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1296 	}
1297 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1298 		selcnt[0]++;
1299 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1300 	}
1301 
1302 	/* authenticator selector list */
1303 	selcnt = frm;
1304 	ADDSHORT(frm, 0);			/* selector count */
1305 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1306 		selcnt[0]++;
1307 		ADDSELECTOR(frm, key_mgt_unspec);
1308 	}
1309 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1310 		selcnt[0]++;
1311 		ADDSELECTOR(frm, key_mgt_psk);
1312 	}
1313 
1314 	/* optional capabilities */
1315 	ADDSHORT(frm, rsn->rsn_caps);
1316 	/* XXX PMKID */
1317 
1318 	/* calculate element length */
1319 	ie[1] = frm - ie - 2;
1320 	KASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1321 		("RSN IE too big, %u > %zu",
1322 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1323 	return frm;
1324 #undef ADDSELECTOR
1325 #undef ADDSHORT
1326 #undef RSN_OUI_BYTES
1327 }
1328 
1329 /*
1330  * Add a WPA/RSN element to a frame.
1331  */
1332 static uint8_t *
1333 ieee80211_add_wpa(uint8_t *frm, struct ieee80211com *ic)
1334 {
1335 
1336 	KASSERT(ic->ic_flags & IEEE80211_F_WPA, ("no WPA/RSN!"));
1337 	if (ic->ic_flags & IEEE80211_F_WPA2)
1338 		frm = ieee80211_setup_rsn_ie(ic, frm);
1339 	if (ic->ic_flags & IEEE80211_F_WPA1)
1340 		frm = ieee80211_setup_wpa_ie(ic, frm);
1341 	return frm;
1342 }
1343 
1344 #define	WME_OUI_BYTES		0x00, 0x50, 0xf2
1345 /*
1346  * Add a WME information element to a frame.
1347  */
1348 static uint8_t *
1349 ieee80211_add_wme_info(uint8_t *frm, struct ieee80211_wme_state *wme)
1350 {
1351 	static const struct ieee80211_wme_info info = {
1352 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1353 		.wme_len	= sizeof(struct ieee80211_wme_info) - 2,
1354 		.wme_oui	= { WME_OUI_BYTES },
1355 		.wme_type	= WME_OUI_TYPE,
1356 		.wme_subtype	= WME_INFO_OUI_SUBTYPE,
1357 		.wme_version	= WME_VERSION,
1358 		.wme_info	= 0,
1359 	};
1360 	memcpy(frm, &info, sizeof(info));
1361 	return frm + sizeof(info);
1362 }
1363 
1364 /*
1365  * Add a WME parameters element to a frame.
1366  */
1367 static uint8_t *
1368 ieee80211_add_wme_param(uint8_t *frm, struct ieee80211_wme_state *wme)
1369 {
1370 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
1371 #define	ADDSHORT(frm, v) do {			\
1372 	frm[0] = (v) & 0xff;			\
1373 	frm[1] = (v) >> 8;			\
1374 	frm += 2;				\
1375 } while (0)
1376 	/* NB: this works 'cuz a param has an info at the front */
1377 	static const struct ieee80211_wme_info param = {
1378 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1379 		.wme_len	= sizeof(struct ieee80211_wme_param) - 2,
1380 		.wme_oui	= { WME_OUI_BYTES },
1381 		.wme_type	= WME_OUI_TYPE,
1382 		.wme_subtype	= WME_PARAM_OUI_SUBTYPE,
1383 		.wme_version	= WME_VERSION,
1384 	};
1385 	int i;
1386 
1387 	memcpy(frm, &param, sizeof(param));
1388 	frm += __offsetof(struct ieee80211_wme_info, wme_info);
1389 	*frm++ = wme->wme_bssChanParams.cap_info;	/* AC info */
1390 	*frm++ = 0;					/* reserved field */
1391 	for (i = 0; i < WME_NUM_AC; i++) {
1392 		const struct wmeParams *ac =
1393 		       &wme->wme_bssChanParams.cap_wmeParams[i];
1394 		*frm++ = SM(i, WME_PARAM_ACI)
1395 		       | SM(ac->wmep_acm, WME_PARAM_ACM)
1396 		       | SM(ac->wmep_aifsn, WME_PARAM_AIFSN)
1397 		       ;
1398 		*frm++ = SM(ac->wmep_logcwmax, WME_PARAM_LOGCWMAX)
1399 		       | SM(ac->wmep_logcwmin, WME_PARAM_LOGCWMIN)
1400 		       ;
1401 		ADDSHORT(frm, ac->wmep_txopLimit);
1402 	}
1403 	return frm;
1404 #undef SM
1405 #undef ADDSHORT
1406 }
1407 #undef WME_OUI_BYTES
1408 
1409 #define	ATH_OUI_BYTES		0x00, 0x03, 0x7f
1410 /*
1411  * Add a WME information element to a frame.
1412  */
1413 static uint8_t *
1414 ieee80211_add_ath(uint8_t *frm, uint8_t caps, uint16_t defkeyix)
1415 {
1416 	static const struct ieee80211_ath_ie info = {
1417 		.ath_id		= IEEE80211_ELEMID_VENDOR,
1418 		.ath_len	= sizeof(struct ieee80211_ath_ie) - 2,
1419 		.ath_oui	= { ATH_OUI_BYTES },
1420 		.ath_oui_type	= ATH_OUI_TYPE,
1421 		.ath_oui_subtype= ATH_OUI_SUBTYPE,
1422 		.ath_version	= ATH_OUI_VERSION,
1423 	};
1424 	struct ieee80211_ath_ie *ath = (struct ieee80211_ath_ie *) frm;
1425 
1426 	memcpy(frm, &info, sizeof(info));
1427 	ath->ath_capability = caps;
1428 	ath->ath_defkeyix[0] = (defkeyix & 0xff);
1429 	ath->ath_defkeyix[1] = ((defkeyix >> 8) & 0xff);
1430 	return frm + sizeof(info);
1431 }
1432 #undef ATH_OUI_BYTES
1433 
1434 /*
1435  * Send a probe request frame with the specified ssid
1436  * and any optional information element data.
1437  */
1438 int
1439 ieee80211_send_probereq(struct ieee80211_node *ni,
1440 	const uint8_t sa[IEEE80211_ADDR_LEN],
1441 	const uint8_t da[IEEE80211_ADDR_LEN],
1442 	const uint8_t bssid[IEEE80211_ADDR_LEN],
1443 	const uint8_t *ssid, size_t ssidlen,
1444 	const void *optie, size_t optielen)
1445 {
1446 	struct ieee80211com *ic = ni->ni_ic;
1447 	struct ieee80211_frame *wh;
1448 	const struct ieee80211_rateset *rs;
1449 	struct mbuf *m;
1450 	uint8_t *frm;
1451 
1452 	/*
1453 	 * Hold a reference on the node so it doesn't go away until after
1454 	 * the xmit is complete all the way in the driver.  On error we
1455 	 * will remove our reference.
1456 	 */
1457 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1458 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1459 		__func__, __LINE__,
1460 		ni, ether_sprintf(ni->ni_macaddr),
1461 		ieee80211_node_refcnt(ni)+1);
1462 	ieee80211_ref_node(ni);
1463 
1464 	/*
1465 	 * prreq frame format
1466 	 *	[tlv] ssid
1467 	 *	[tlv] supported rates
1468 	 *	[tlv] extended supported rates
1469 	 *	[tlv] user-specified ie's
1470 	 */
1471 	m = ieee80211_getmgtframe(&frm,
1472 		 ic->ic_headroom + sizeof(struct ieee80211_frame),
1473 		 2 + IEEE80211_NWID_LEN
1474 	       + 2 + IEEE80211_RATE_SIZE
1475 	       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1476 	       + (optie != NULL ? optielen : 0)
1477 	);
1478 	if (m == NULL) {
1479 		ic->ic_stats.is_tx_nobuf++;
1480 		ieee80211_free_node(ni);
1481 		return ENOMEM;
1482 	}
1483 
1484 	frm = ieee80211_add_ssid(frm, ssid, ssidlen);
1485 	rs = ieee80211_get_suprates(ic, ic->ic_curchan);
1486 	frm = ieee80211_add_rates(frm, rs);
1487 	frm = ieee80211_add_xrates(frm, rs);
1488 
1489 	if (optie != NULL) {
1490 		memcpy(frm, optie, optielen);
1491 		frm += optielen;
1492 	}
1493 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1494 
1495 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1496 	if (m == NULL)
1497 		return ENOMEM;
1498 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
1499 	m->m_pkthdr.rcvif = (void *)ni;
1500 
1501 	wh = mtod(m, struct ieee80211_frame *);
1502 	ieee80211_send_setup(ic, ni, wh,
1503 		IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_PROBE_REQ,
1504 		sa, da, bssid);
1505 	/* XXX power management? */
1506 
1507 	IEEE80211_NODE_STAT(ni, tx_probereq);
1508 	IEEE80211_NODE_STAT(ni, tx_mgmt);
1509 
1510 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
1511 	    "[%s] send probe req on channel %u\n",
1512 	    ether_sprintf(wh->i_addr1),
1513 	    ieee80211_chan2ieee(ic, ic->ic_curchan));
1514 
1515 	IF_ENQUEUE(&ic->ic_mgtq, m);
1516 	if_start(ic->ic_ifp);
1517 	return 0;
1518 }
1519 
1520 /*
1521  * Calculate capability information for mgt frames.
1522  */
1523 static uint16_t
1524 getcapinfo(struct ieee80211com *ic, struct ieee80211_channel *chan)
1525 {
1526 	uint16_t capinfo;
1527 
1528 	KASSERT(ic->ic_opmode != IEEE80211_M_STA, ("station mode"));
1529 
1530 	if (ic->ic_opmode == IEEE80211_M_HOSTAP)
1531 		capinfo = IEEE80211_CAPINFO_ESS;
1532 	else if (ic->ic_opmode == IEEE80211_M_IBSS)
1533 		capinfo = IEEE80211_CAPINFO_IBSS;
1534 	else
1535 		capinfo = 0;
1536 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1537 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1538 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1539 	    IEEE80211_IS_CHAN_2GHZ(chan))
1540 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1541 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1542 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1543 	return capinfo;
1544 }
1545 
1546 /*
1547  * Send a management frame.  The node is for the destination (or ic_bss
1548  * when in station mode).  Nodes other than ic_bss have their reference
1549  * count bumped to reflect our use for an indeterminant time.
1550  */
1551 int
1552 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
1553 	int type, int arg)
1554 {
1555 #define	HTFLAGS (IEEE80211_NODE_HT | IEEE80211_NODE_HTCOMPAT)
1556 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
1557 	const struct ieee80211_rateset *rs;
1558 	struct mbuf *m;
1559 	uint8_t *frm;
1560 	uint16_t capinfo;
1561 	int has_challenge, is_shared_key, ret, status;
1562 
1563 	KASSERT(ni != NULL, ("null node"));
1564 
1565 	/*
1566 	 * Hold a reference on the node so it doesn't go away until after
1567 	 * the xmit is complete all the way in the driver.  On error we
1568 	 * will remove our reference.
1569 	 */
1570 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1571 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1572 		__func__, __LINE__,
1573 		ni, ether_sprintf(ni->ni_macaddr),
1574 		ieee80211_node_refcnt(ni)+1);
1575 	ieee80211_ref_node(ni);
1576 
1577 	switch (type) {
1578 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1579 		/*
1580 		 * probe response frame format
1581 		 *	[8] time stamp
1582 		 *	[2] beacon interval
1583 		 *	[2] cabability information
1584 		 *	[tlv] ssid
1585 		 *	[tlv] supported rates
1586 		 *	[tlv] parameter set (FH/DS)
1587 		 *	[tlv] parameter set (IBSS)
1588 		 *	[tlv] extended rate phy (ERP)
1589 		 *	[tlv] extended supported rates
1590 		 *	[tlv] WPA
1591 		 *	[tlv] WME (optional)
1592 		 *	[tlv] HT capabilities
1593 		 *	[tlv] HT information
1594 		 *	[tlv] Vendor OUI HT capabilities (optional)
1595 		 *	[tlv] Vendor OUI HT information (optional)
1596 		 *	[tlv] Atheros capabilities
1597 		 */
1598 		m = ieee80211_getmgtframe(&frm,
1599 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1600 			 8
1601 		       + sizeof(uint16_t)
1602 		       + sizeof(uint16_t)
1603 		       + 2 + IEEE80211_NWID_LEN
1604 		       + 2 + IEEE80211_RATE_SIZE
1605 		       + 7	/* max(7,3) */
1606 		       + 6
1607 		       + 3
1608 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1609 		       /* XXX !WPA1+WPA2 fits w/o a cluster */
1610 		       + (ic->ic_flags & IEEE80211_F_WPA ?
1611 				2*sizeof(struct ieee80211_ie_wpa) : 0)
1612 		       + sizeof(struct ieee80211_wme_param)
1613 		       /* XXX check for cluster requirement */
1614 		       + 2*sizeof(struct ieee80211_ie_htcap) + 4
1615 		       + 2*sizeof(struct ieee80211_ie_htinfo) + 4
1616 		       + sizeof(struct ieee80211_ath_ie)
1617 		);
1618 		if (m == NULL)
1619 			senderr(ENOMEM, is_tx_nobuf);
1620 
1621 		memset(frm, 0, 8);	/* timestamp should be filled later */
1622 		frm += 8;
1623 		*(uint16_t *)frm = htole16(ic->ic_bss->ni_intval);
1624 		frm += 2;
1625 		capinfo = getcapinfo(ic, ic->ic_curchan);
1626 		*(uint16_t *)frm = htole16(capinfo);
1627 		frm += 2;
1628 
1629 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
1630 				ic->ic_bss->ni_esslen);
1631 		rs = ieee80211_get_suprates(ic, ic->ic_curchan);
1632 		frm = ieee80211_add_rates(frm, rs);
1633 
1634 		if (IEEE80211_IS_CHAN_FHSS(ic->ic_curchan)) {
1635                         *frm++ = IEEE80211_ELEMID_FHPARMS;
1636                         *frm++ = 5;
1637                         *frm++ = ni->ni_fhdwell & 0x00ff;
1638                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
1639                         *frm++ = IEEE80211_FH_CHANSET(
1640 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1641                         *frm++ = IEEE80211_FH_CHANPAT(
1642 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1643                         *frm++ = ni->ni_fhindex;
1644 		} else {
1645 			*frm++ = IEEE80211_ELEMID_DSPARMS;
1646 			*frm++ = 1;
1647 			*frm++ = ieee80211_chan2ieee(ic, ic->ic_curchan);
1648 		}
1649 
1650 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
1651 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1652 			*frm++ = 2;
1653 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1654 		}
1655 		if (ic->ic_flags & IEEE80211_F_WPA)
1656 			frm = ieee80211_add_wpa(frm, ic);
1657 		if (IEEE80211_IS_CHAN_ANYG(ic->ic_curchan))
1658 			frm = ieee80211_add_erp(frm, ic);
1659 		frm = ieee80211_add_xrates(frm, rs);
1660 		/*
1661 		 * NB: legacy 11b clients do not get certain ie's.
1662 		 *     The caller identifies such clients by passing
1663 		 *     a token in arg to us.  Could expand this to be
1664 		 *     any legacy client for stuff like HT ie's.
1665 		 */
1666 		if (IEEE80211_IS_CHAN_HT(ic->ic_curchan) &&
1667 		    arg != IEEE80211_SEND_LEGACY_11B) {
1668 			frm = ieee80211_add_htcap(frm, ni);
1669 			frm = ieee80211_add_htinfo(frm, ni);
1670 		}
1671 		if (ic->ic_flags & IEEE80211_F_WME)
1672 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1673 		if (IEEE80211_IS_CHAN_HT(ic->ic_curchan) &&
1674 		    (ic->ic_flags_ext & IEEE80211_FEXT_HTCOMPAT) &&
1675 		    arg != IEEE80211_SEND_LEGACY_11B) {
1676 			frm = ieee80211_add_htcap_vendor(frm, ni);
1677 			frm = ieee80211_add_htinfo_vendor(frm, ni);
1678 		}
1679 		if (ni->ni_ath_ie != NULL)
1680 			frm = ieee80211_add_ath(frm, ni->ni_ath_flags,
1681 				ni->ni_ath_defkeyix);
1682 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1683 		break;
1684 
1685 	case IEEE80211_FC0_SUBTYPE_AUTH:
1686 		status = arg >> 16;
1687 		arg &= 0xffff;
1688 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
1689 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
1690 		    ni->ni_challenge != NULL);
1691 
1692 		/*
1693 		 * Deduce whether we're doing open authentication or
1694 		 * shared key authentication.  We do the latter if
1695 		 * we're in the middle of a shared key authentication
1696 		 * handshake or if we're initiating an authentication
1697 		 * request and configured to use shared key.
1698 		 */
1699 		is_shared_key = has_challenge ||
1700 		     arg >= IEEE80211_AUTH_SHARED_RESPONSE ||
1701 		     (arg == IEEE80211_AUTH_SHARED_REQUEST &&
1702 		      ic->ic_bss->ni_authmode == IEEE80211_AUTH_SHARED);
1703 
1704 		m = ieee80211_getmgtframe(&frm,
1705 			  ic->ic_headroom + sizeof(struct ieee80211_frame),
1706 			  3 * sizeof(uint16_t)
1707 			+ (has_challenge && status == IEEE80211_STATUS_SUCCESS ?
1708 				sizeof(uint16_t)+IEEE80211_CHALLENGE_LEN : 0)
1709 		);
1710 		if (m == NULL)
1711 			senderr(ENOMEM, is_tx_nobuf);
1712 
1713 		((uint16_t *)frm)[0] =
1714 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
1715 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
1716 		((uint16_t *)frm)[1] = htole16(arg);	/* sequence number */
1717 		((uint16_t *)frm)[2] = htole16(status);/* status */
1718 
1719 		if (has_challenge && status == IEEE80211_STATUS_SUCCESS) {
1720 			((uint16_t *)frm)[3] =
1721 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
1722 			    IEEE80211_ELEMID_CHALLENGE);
1723 			memcpy(&((uint16_t *)frm)[4], ni->ni_challenge,
1724 			    IEEE80211_CHALLENGE_LEN);
1725 			m->m_pkthdr.len = m->m_len =
1726 				4 * sizeof(uint16_t) + IEEE80211_CHALLENGE_LEN;
1727 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
1728 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1729 				    "[%s] request encrypt frame (%s)\n",
1730 				    ether_sprintf(ni->ni_macaddr), __func__);
1731 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
1732 			}
1733 		} else
1734 			m->m_pkthdr.len = m->m_len = 3 * sizeof(uint16_t);
1735 
1736 		/* XXX not right for shared key */
1737 		if (status == IEEE80211_STATUS_SUCCESS)
1738 			IEEE80211_NODE_STAT(ni, tx_auth);
1739 		else
1740 			IEEE80211_NODE_STAT(ni, tx_auth_fail);
1741 
1742 		if (ic->ic_opmode == IEEE80211_M_STA)
1743 			ieee80211_add_callback(m, ieee80211_tx_mgt_cb,
1744 				(void *) ic->ic_state);
1745 		break;
1746 
1747 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
1748 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1749 			"[%s] send station deauthenticate (reason %d)\n",
1750 			ether_sprintf(ni->ni_macaddr), arg);
1751 		m = ieee80211_getmgtframe(&frm,
1752 			ic->ic_headroom + sizeof(struct ieee80211_frame),
1753 			sizeof(uint16_t));
1754 		if (m == NULL)
1755 			senderr(ENOMEM, is_tx_nobuf);
1756 		*(uint16_t *)frm = htole16(arg);	/* reason */
1757 		m->m_pkthdr.len = m->m_len = sizeof(uint16_t);
1758 
1759 		IEEE80211_NODE_STAT(ni, tx_deauth);
1760 		IEEE80211_NODE_STAT_SET(ni, tx_deauth_code, arg);
1761 
1762 		ieee80211_node_unauthorize(ni);		/* port closed */
1763 		break;
1764 
1765 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1766 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1767 		/*
1768 		 * asreq frame format
1769 		 *	[2] capability information
1770 		 *	[2] listen interval
1771 		 *	[6*] current AP address (reassoc only)
1772 		 *	[tlv] ssid
1773 		 *	[tlv] supported rates
1774 		 *	[tlv] extended supported rates
1775 		 *	[tlv] WME
1776 		 *	[tlv] HT capabilities
1777 		 *	[tlv] Vendor OUI HT capabilities (optional)
1778 		 *	[tlv] Atheros capabilities (if negotiated)
1779 		 *	[tlv] user-specified ie's
1780 		 */
1781 		m = ieee80211_getmgtframe(&frm,
1782 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1783 			 sizeof(uint16_t)
1784 		       + sizeof(uint16_t)
1785 		       + IEEE80211_ADDR_LEN
1786 		       + 2 + IEEE80211_NWID_LEN
1787 		       + 2 + IEEE80211_RATE_SIZE
1788 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1789 		       + sizeof(struct ieee80211_wme_info)
1790 		       + 2*sizeof(struct ieee80211_ie_htcap) + 4
1791 		       + sizeof(struct ieee80211_ath_ie)
1792 		       + (ic->ic_opt_ie != NULL ? ic->ic_opt_ie_len : 0)
1793 		);
1794 		if (m == NULL)
1795 			senderr(ENOMEM, is_tx_nobuf);
1796 
1797 		KASSERT(ic->ic_opmode == IEEE80211_M_STA,
1798 		    ("wrong mode %u", ic->ic_opmode));
1799 		capinfo = IEEE80211_CAPINFO_ESS;
1800 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1801 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1802 		/*
1803 		 * NB: Some 11a AP's reject the request when
1804 		 *     short premable is set.
1805 		 */
1806 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1807 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1808 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1809 		if (IEEE80211_IS_CHAN_ANYG(ic->ic_curchan) &&
1810 		    (ic->ic_caps & IEEE80211_C_SHSLOT))
1811 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1812 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SPECTRUM_MGMT) &&
1813 		    (ic->ic_flags & IEEE80211_F_DOTH))
1814 			capinfo |= IEEE80211_CAPINFO_SPECTRUM_MGMT;
1815 		*(uint16_t *)frm = htole16(capinfo);
1816 		frm += 2;
1817 
1818 		KASSERT(ic->ic_bss->ni_intval != 0,
1819 			("beacon interval is zero!"));
1820 		*(uint16_t *)frm = htole16(howmany(ic->ic_lintval,
1821 						   ic->ic_bss->ni_intval));
1822 		frm += 2;
1823 
1824 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
1825 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
1826 			frm += IEEE80211_ADDR_LEN;
1827 		}
1828 
1829 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
1830 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1831 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1832 		if ((ic->ic_flags_ext & IEEE80211_FEXT_HT) &&
1833 		    ni->ni_htcap_ie != NULL &&
1834 		    ni->ni_htcap_ie[0] == IEEE80211_ELEMID_HTCAP)
1835 			frm = ieee80211_add_htcap(frm, ni);
1836 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1837 			frm = ieee80211_add_wme_info(frm, &ic->ic_wme);
1838 		if ((ic->ic_flags_ext & IEEE80211_FEXT_HT) &&
1839 		    ni->ni_htcap_ie != NULL &&
1840 		    ni->ni_htcap_ie[0] == IEEE80211_ELEMID_VENDOR)
1841 			frm = ieee80211_add_htcap_vendor(frm, ni);
1842 		if (IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS))
1843 			frm = ieee80211_add_ath(frm,
1844 				IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS),
1845 				(ic->ic_flags & IEEE80211_F_WPA) == 0 &&
1846 				ni->ni_authmode != IEEE80211_AUTH_8021X &&
1847 				ic->ic_def_txkey != IEEE80211_KEYIX_NONE ?
1848 				ic->ic_def_txkey : 0x7fff);
1849 		if (ic->ic_opt_ie != NULL) {
1850 			memcpy(frm, ic->ic_opt_ie, ic->ic_opt_ie_len);
1851 			frm += ic->ic_opt_ie_len;
1852 		}
1853 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1854 
1855 		ieee80211_add_callback(m, ieee80211_tx_mgt_cb,
1856 			(void *) ic->ic_state);
1857 		break;
1858 
1859 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1860 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1861 		/*
1862 		 * asresp frame format
1863 		 *	[2] capability information
1864 		 *	[2] status
1865 		 *	[2] association ID
1866 		 *	[tlv] supported rates
1867 		 *	[tlv] extended supported rates
1868 		 *	[tlv] WME (if enabled and STA enabled)
1869 		 *	[tlv] HT capabilities (standard or vendor OUI)
1870 		 *	[tlv] HT information (standard or vendor OUI)
1871 		 *	[tlv] Atheros capabilities (if enabled and STA enabled)
1872 		 */
1873 		m = ieee80211_getmgtframe(&frm,
1874 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1875 			 sizeof(uint16_t)
1876 		       + sizeof(uint16_t)
1877 		       + sizeof(uint16_t)
1878 		       + 2 + IEEE80211_RATE_SIZE
1879 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1880 		       + sizeof(struct ieee80211_wme_param)
1881 		       + sizeof(struct ieee80211_ie_htcap) + 4
1882 		       + sizeof(struct ieee80211_ie_htinfo) + 4
1883 		       + sizeof(struct ieee80211_ath_ie)
1884 		);
1885 		if (m == NULL)
1886 			senderr(ENOMEM, is_tx_nobuf);
1887 
1888 		capinfo = getcapinfo(ic, ic->ic_curchan);
1889 		*(uint16_t *)frm = htole16(capinfo);
1890 		frm += 2;
1891 
1892 		*(uint16_t *)frm = htole16(arg);	/* status */
1893 		frm += 2;
1894 
1895 		if (arg == IEEE80211_STATUS_SUCCESS) {
1896 			*(uint16_t *)frm = htole16(ni->ni_associd);
1897 			IEEE80211_NODE_STAT(ni, tx_assoc);
1898 		} else
1899 			IEEE80211_NODE_STAT(ni, tx_assoc_fail);
1900 		frm += 2;
1901 
1902 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1903 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1904 		/* NB: respond according to what we received */
1905 		if ((ni->ni_flags & HTFLAGS) == IEEE80211_NODE_HT) {
1906 			frm = ieee80211_add_htcap(frm, ni);
1907 			frm = ieee80211_add_htinfo(frm, ni);
1908 		}
1909 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1910 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1911 		if ((ni->ni_flags & HTFLAGS) == HTFLAGS) {
1912 			frm = ieee80211_add_htcap_vendor(frm, ni);
1913 			frm = ieee80211_add_htinfo_vendor(frm, ni);
1914 		}
1915 		if (IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS))
1916 			frm = ieee80211_add_ath(frm,
1917 				IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS),
1918 				ni->ni_ath_defkeyix);
1919 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1920 		break;
1921 
1922 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
1923 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1924 			"[%s] send station disassociate (reason %d)\n",
1925 			ether_sprintf(ni->ni_macaddr), arg);
1926 		m = ieee80211_getmgtframe(&frm,
1927 			ic->ic_headroom + sizeof(struct ieee80211_frame),
1928 			sizeof(uint16_t));
1929 		if (m == NULL)
1930 			senderr(ENOMEM, is_tx_nobuf);
1931 		*(uint16_t *)frm = htole16(arg);	/* reason */
1932 		m->m_pkthdr.len = m->m_len = sizeof(uint16_t);
1933 
1934 		IEEE80211_NODE_STAT(ni, tx_disassoc);
1935 		IEEE80211_NODE_STAT_SET(ni, tx_disassoc_code, arg);
1936 		break;
1937 
1938 	default:
1939 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1940 			"[%s] invalid mgmt frame type %u\n",
1941 			ether_sprintf(ni->ni_macaddr), type);
1942 		senderr(EINVAL, is_tx_unknownmgt);
1943 		/* NOTREACHED */
1944 	}
1945 
1946 	ret = ieee80211_mgmt_output(ic, ni, m, type);
1947 	if (ret != 0)
1948 		goto bad;
1949 	return 0;
1950 bad:
1951 	ieee80211_free_node(ni);
1952 	return ret;
1953 #undef senderr
1954 #undef HTFLAGS
1955 }
1956 
1957 static void
1958 ieee80211_tx_mgt_timeout(void *arg)
1959 {
1960 	struct ieee80211_node *ni = arg;
1961 	struct ieee80211com *ic	= ni->ni_ic;
1962 
1963 	if (ic->ic_state != IEEE80211_S_INIT &&
1964 	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
1965 		/*
1966 		 * NB: it's safe to specify a timeout as the reason here;
1967 		 *     it'll only be used in the right state.
1968 		 */
1969 		ieee80211_new_state(ic, IEEE80211_S_SCAN,
1970 			IEEE80211_SCAN_FAIL_TIMEOUT);
1971 	}
1972 }
1973 
1974 static void
1975 ieee80211_tx_mgt_cb(struct ieee80211_node *ni, void *arg, int status)
1976 {
1977 	struct ieee80211com *ic = ni->ni_ic;
1978 	enum ieee80211_state ostate = (enum ieee80211_state) arg;
1979 
1980 	/*
1981 	 * Frame transmit completed; arrange timer callback.  If
1982 	 * transmit was successfuly we wait for response.  Otherwise
1983 	 * we arrange an immediate callback instead of doing the
1984 	 * callback directly since we don't know what state the driver
1985 	 * is in (e.g. what locks it is holding).  This work should
1986 	 * not be too time-critical and not happen too often so the
1987 	 * added overhead is acceptable.
1988 	 *
1989 	 * XXX what happens if !acked but response shows up before callback?
1990 	 */
1991 	if (ic->ic_state == ostate)
1992 		callout_reset(&ic->ic_mgtsend,
1993 			status == 0 ? IEEE80211_TRANS_WAIT*hz : 0,
1994 			ieee80211_tx_mgt_timeout, ni);
1995 }
1996 
1997 /*
1998  * Allocate a beacon frame and fillin the appropriate bits.
1999  */
2000 struct mbuf *
2001 ieee80211_beacon_alloc(struct ieee80211_node *ni,
2002 	struct ieee80211_beacon_offsets *bo)
2003 {
2004 	struct ieee80211com *ic = ni->ni_ic;
2005 	struct ifnet *ifp = ic->ic_ifp;
2006 	struct ieee80211_frame *wh;
2007 	struct mbuf *m;
2008 	int pktlen;
2009 	uint8_t *frm;
2010 	uint16_t capinfo;
2011 	struct ieee80211_rateset *rs;
2012 
2013 	/*
2014 	 * beacon frame format
2015 	 *	[8] time stamp
2016 	 *	[2] beacon interval
2017 	 *	[2] cabability information
2018 	 *	[tlv] ssid
2019 	 *	[tlv] supported rates
2020 	 *	[3] parameter set (DS)
2021 	 *	[tlv] parameter set (IBSS/TIM)
2022 	 *	[tlv] country code
2023 	 *	[tlv] extended rate phy (ERP)
2024 	 *	[tlv] extended supported rates
2025 	 *	[tlv] WME parameters
2026 	 *	[tlv] WPA/RSN parameters
2027 	 *	[tlv] HT capabilities
2028 	 *	[tlv] HT information
2029 	 *	[tlv] Vendor OUI HT capabilities (optional)
2030 	 *	[tlv] Vendor OUI HT information (optional)
2031 	 * XXX Vendor-specific OIDs (e.g. Atheros)
2032 	 * NB: we allocate the max space required for the TIM bitmap.
2033 	 */
2034 	rs = &ni->ni_rates;
2035 	pktlen =   8					/* time stamp */
2036 		 + sizeof(uint16_t)			/* beacon interval */
2037 		 + sizeof(uint16_t)			/* capabilities */
2038 		 + 2 + ni->ni_esslen			/* ssid */
2039 	         + 2 + IEEE80211_RATE_SIZE		/* supported rates */
2040 	         + 2 + 1				/* DS parameters */
2041 		 + 2 + 4 + ic->ic_tim_len		/* DTIM/IBSSPARMS */
2042 		 + sizeof(struct ieee80211_country_ie)	/* country code */
2043 		 + 2 + 1				/* ERP */
2044 	         + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
2045 		 + (ic->ic_caps & IEEE80211_C_WME ?	/* WME */
2046 			sizeof(struct ieee80211_wme_param) : 0)
2047 		 + (ic->ic_caps & IEEE80211_C_WPA ?	/* WPA 1+2 */
2048 			2*sizeof(struct ieee80211_ie_wpa) : 0)
2049 		 /* XXX conditional? */
2050 		 + 4+2*sizeof(struct ieee80211_ie_htcap)/* HT caps */
2051 		 + 4+2*sizeof(struct ieee80211_ie_htinfo)/* HT info */
2052 		 ;
2053 	m = ieee80211_getmgtframe(&frm,
2054 		ic->ic_headroom + sizeof(struct ieee80211_frame), pktlen);
2055 	if (m == NULL) {
2056 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
2057 			"%s: cannot get buf; size %u\n", __func__, pktlen);
2058 		ic->ic_stats.is_tx_nobuf++;
2059 		return NULL;
2060 	}
2061 
2062 	memset(bo, 0, sizeof(*bo));
2063 
2064 	memset(frm, 0, 8);	/* XXX timestamp is set by hardware/driver */
2065 	frm += 8;
2066 	*(uint16_t *)frm = htole16(ni->ni_intval);
2067 	frm += 2;
2068 	capinfo = getcapinfo(ic, ni->ni_chan);
2069 	bo->bo_caps = (uint16_t *)frm;
2070 	*(uint16_t *)frm = htole16(capinfo);
2071 	frm += 2;
2072 	*frm++ = IEEE80211_ELEMID_SSID;
2073 	if ((ic->ic_flags & IEEE80211_F_HIDESSID) == 0) {
2074 		*frm++ = ni->ni_esslen;
2075 		memcpy(frm, ni->ni_essid, ni->ni_esslen);
2076 		frm += ni->ni_esslen;
2077 	} else
2078 		*frm++ = 0;
2079 	frm = ieee80211_add_rates(frm, rs);
2080 	if (!IEEE80211_IS_CHAN_FHSS(ic->ic_bsschan)) {
2081 		*frm++ = IEEE80211_ELEMID_DSPARMS;
2082 		*frm++ = 1;
2083 		*frm++ = ieee80211_chan2ieee(ic, ic->ic_bsschan);
2084 	}
2085 	bo->bo_tim = frm;
2086 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
2087 		*frm++ = IEEE80211_ELEMID_IBSSPARMS;
2088 		*frm++ = 2;
2089 		*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
2090 		bo->bo_tim_len = 0;
2091 	} else if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
2092 		struct ieee80211_tim_ie *tie = (struct ieee80211_tim_ie *) frm;
2093 
2094 		tie->tim_ie = IEEE80211_ELEMID_TIM;
2095 		tie->tim_len = 4;	/* length */
2096 		tie->tim_count = 0;	/* DTIM count */
2097 		tie->tim_period = ic->ic_dtim_period;	/* DTIM period */
2098 		tie->tim_bitctl = 0;	/* bitmap control */
2099 		tie->tim_bitmap[0] = 0;	/* Partial Virtual Bitmap */
2100 		frm += sizeof(struct ieee80211_tim_ie);
2101 		bo->bo_tim_len = 1;
2102 	}
2103 	bo->bo_tim_trailer = frm;
2104 	if (ic->ic_flags & IEEE80211_F_DOTH)
2105 		frm = ieee80211_add_countryie(frm, ic,
2106 			ic->ic_countrycode, ic->ic_location);
2107 	if (ic->ic_flags & IEEE80211_F_WPA)
2108 		frm = ieee80211_add_wpa(frm, ic);
2109 	if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan)) {
2110 		bo->bo_erp = frm;
2111 		frm = ieee80211_add_erp(frm, ic);
2112 	}
2113 	frm = ieee80211_add_xrates(frm, rs);
2114 	if (IEEE80211_IS_CHAN_HT(ic->ic_bsschan)) {
2115 		frm = ieee80211_add_htcap(frm, ni);
2116 		bo->bo_htinfo = frm;
2117 		frm = ieee80211_add_htinfo(frm, ni);
2118 	}
2119 	if (ic->ic_flags & IEEE80211_F_WME) {
2120 		bo->bo_wme = frm;
2121 		frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
2122 	}
2123 	if (IEEE80211_IS_CHAN_HT(ic->ic_bsschan) &&
2124 	    (ic->ic_flags_ext & IEEE80211_FEXT_HTCOMPAT)) {
2125 		frm = ieee80211_add_htcap_vendor(frm, ni);
2126 		frm = ieee80211_add_htinfo_vendor(frm, ni);
2127 	}
2128 	bo->bo_tim_trailer_len = frm - bo->bo_tim_trailer;
2129 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
2130 
2131 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
2132 	KASSERT(m != NULL, ("no space for 802.11 header?"));
2133 	wh = mtod(m, struct ieee80211_frame *);
2134 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
2135 	    IEEE80211_FC0_SUBTYPE_BEACON;
2136 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
2137 	*(uint16_t *)wh->i_dur = 0;
2138 	IEEE80211_ADDR_COPY(wh->i_addr1, ifp->if_broadcastaddr);
2139 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
2140 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
2141 	*(uint16_t *)wh->i_seq = 0;
2142 
2143 	return m;
2144 }
2145 
2146 /*
2147  * Update the dynamic parts of a beacon frame based on the current state.
2148  */
2149 int
2150 ieee80211_beacon_update(struct ieee80211_node *ni,
2151 	struct ieee80211_beacon_offsets *bo, struct mbuf *m, int mcast)
2152 {
2153 	struct ieee80211com *ic = ni->ni_ic;
2154 	int len_changed = 0;
2155 	uint16_t capinfo;
2156 
2157 	IEEE80211_BEACON_LOCK(ic);
2158 	/* XXX faster to recalculate entirely or just changes? */
2159 	capinfo = getcapinfo(ic, ni->ni_chan);
2160 	*bo->bo_caps = htole16(capinfo);
2161 
2162 	if (ic->ic_flags & IEEE80211_F_WME) {
2163 		struct ieee80211_wme_state *wme = &ic->ic_wme;
2164 
2165 		/*
2166 		 * Check for agressive mode change.  When there is
2167 		 * significant high priority traffic in the BSS
2168 		 * throttle back BE traffic by using conservative
2169 		 * parameters.  Otherwise BE uses agressive params
2170 		 * to optimize performance of legacy/non-QoS traffic.
2171 		 */
2172 		if (wme->wme_flags & WME_F_AGGRMODE) {
2173 			if (wme->wme_hipri_traffic >
2174 			    wme->wme_hipri_switch_thresh) {
2175 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
2176 				    "%s: traffic %u, disable aggressive mode\n",
2177 				    __func__, wme->wme_hipri_traffic);
2178 				wme->wme_flags &= ~WME_F_AGGRMODE;
2179 				ieee80211_wme_updateparams_locked(ic);
2180 				wme->wme_hipri_traffic =
2181 					wme->wme_hipri_switch_hysteresis;
2182 			} else
2183 				wme->wme_hipri_traffic = 0;
2184 		} else {
2185 			if (wme->wme_hipri_traffic <=
2186 			    wme->wme_hipri_switch_thresh) {
2187 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
2188 				    "%s: traffic %u, enable aggressive mode\n",
2189 				    __func__, wme->wme_hipri_traffic);
2190 				wme->wme_flags |= WME_F_AGGRMODE;
2191 				ieee80211_wme_updateparams_locked(ic);
2192 				wme->wme_hipri_traffic = 0;
2193 			} else
2194 				wme->wme_hipri_traffic =
2195 					wme->wme_hipri_switch_hysteresis;
2196 		}
2197 		if (isset(bo->bo_flags, IEEE80211_BEACON_WME)) {
2198 			(void) ieee80211_add_wme_param(bo->bo_wme, wme);
2199 			clrbit(bo->bo_flags, IEEE80211_BEACON_WME);
2200 		}
2201 	}
2202 
2203 	if (isset(bo->bo_flags, IEEE80211_BEACON_HTINFO)) {
2204 		ieee80211_ht_update_beacon(ic, bo);
2205 		clrbit(bo->bo_flags, IEEE80211_BEACON_HTINFO);
2206 	}
2207 
2208 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {	/* NB: no IBSS support*/
2209 		struct ieee80211_tim_ie *tie =
2210 			(struct ieee80211_tim_ie *) bo->bo_tim;
2211 		if (isset(bo->bo_flags, IEEE80211_BEACON_TIM)) {
2212 			u_int timlen, timoff, i;
2213 			/*
2214 			 * ATIM/DTIM needs updating.  If it fits in the
2215 			 * current space allocated then just copy in the
2216 			 * new bits.  Otherwise we need to move any trailing
2217 			 * data to make room.  Note that we know there is
2218 			 * contiguous space because ieee80211_beacon_allocate
2219 			 * insures there is space in the mbuf to write a
2220 			 * maximal-size virtual bitmap (based on ic_max_aid).
2221 			 */
2222 			/*
2223 			 * Calculate the bitmap size and offset, copy any
2224 			 * trailer out of the way, and then copy in the
2225 			 * new bitmap and update the information element.
2226 			 * Note that the tim bitmap must contain at least
2227 			 * one byte and any offset must be even.
2228 			 */
2229 			if (ic->ic_ps_pending != 0) {
2230 				timoff = 128;		/* impossibly large */
2231 				for (i = 0; i < ic->ic_tim_len; i++)
2232 					if (ic->ic_tim_bitmap[i]) {
2233 						timoff = i &~ 1;
2234 						break;
2235 					}
2236 				KASSERT(timoff != 128, ("tim bitmap empty!"));
2237 				for (i = ic->ic_tim_len-1; i >= timoff; i--)
2238 					if (ic->ic_tim_bitmap[i])
2239 						break;
2240 				timlen = 1 + (i - timoff);
2241 			} else {
2242 				timoff = 0;
2243 				timlen = 1;
2244 			}
2245 			if (timlen != bo->bo_tim_len) {
2246 				/* copy up/down trailer */
2247 				int adjust = tie->tim_bitmap+timlen
2248 					   - bo->bo_tim_trailer;
2249 				ovbcopy(bo->bo_tim_trailer,
2250 				    bo->bo_tim_trailer+adjust,
2251 				    bo->bo_tim_trailer_len);
2252 				bo->bo_tim_trailer += adjust;
2253 				bo->bo_wme += adjust;
2254 				bo->bo_erp += adjust;
2255 				bo->bo_htinfo += adjust;
2256 				bo->bo_tim_len = timlen;
2257 
2258 				/* update information element */
2259 				tie->tim_len = 3 + timlen;
2260 				tie->tim_bitctl = timoff;
2261 				len_changed = 1;
2262 			}
2263 			memcpy(tie->tim_bitmap, ic->ic_tim_bitmap + timoff,
2264 				bo->bo_tim_len);
2265 
2266 			clrbit(bo->bo_flags, IEEE80211_BEACON_TIM);
2267 
2268 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
2269 				"%s: TIM updated, pending %u, off %u, len %u\n",
2270 				__func__, ic->ic_ps_pending, timoff, timlen);
2271 		}
2272 		/* count down DTIM period */
2273 		if (tie->tim_count == 0)
2274 			tie->tim_count = tie->tim_period - 1;
2275 		else
2276 			tie->tim_count--;
2277 		/* update state for buffered multicast frames on DTIM */
2278 		if (mcast && tie->tim_count == 0)
2279 			tie->tim_bitctl |= 1;
2280 		else
2281 			tie->tim_bitctl &= ~1;
2282 		if (isset(bo->bo_flags, IEEE80211_BEACON_ERP)) {
2283 			/*
2284 			 * ERP element needs updating.
2285 			 */
2286 			(void) ieee80211_add_erp(bo->bo_erp, ic);
2287 			clrbit(bo->bo_flags, IEEE80211_BEACON_ERP);
2288 		}
2289 	}
2290 	IEEE80211_BEACON_UNLOCK(ic);
2291 
2292 	return len_changed;
2293 }
2294