xref: /freebsd/sys/net80211/ieee80211_output.c (revision fa030de01267cc324a0b57479715e4a53356b665)
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_spare2;	/* 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 		switch (EVL_PRIOFTAG(ni->ni_vlan)) {
430 		case 1:
431 		case 2:
432 			v_wme_ac = WME_AC_BK;
433 			break;
434 		case 0:
435 		case 3:
436 			v_wme_ac = WME_AC_BE;
437 			break;
438 		case 4:
439 		case 5:
440 			v_wme_ac = WME_AC_VI;
441 			break;
442 		case 6:
443 		case 7:
444 			v_wme_ac = WME_AC_VO;
445 			break;
446 		}
447 	}
448 
449 #ifdef INET
450 	eh = mtod(m, struct ether_header *);
451 	if (eh->ether_type == htons(ETHERTYPE_IP)) {
452 		const struct ip *ip = (struct ip *)
453 			(mtod(m, uint8_t *) + sizeof (*eh));
454 		/*
455 		 * IP frame, map the TOS field.
456 		 */
457 		switch (ip->ip_tos) {
458 		case 0x08:
459 		case 0x20:
460 			d_wme_ac = WME_AC_BK;	/* background */
461 			break;
462 		case 0x28:
463 		case 0xa0:
464 			d_wme_ac = WME_AC_VI;	/* video */
465 			break;
466 		case 0x30:			/* voice */
467 		case 0xe0:
468 		case 0x88:			/* XXX UPSD */
469 		case 0xb8:
470 			d_wme_ac = WME_AC_VO;
471 			break;
472 		default:
473 			d_wme_ac = WME_AC_BE;
474 			break;
475 		}
476 	} else {
477 #endif /* INET */
478 		d_wme_ac = WME_AC_BE;
479 #ifdef INET
480 	}
481 #endif
482 	/*
483 	 * Use highest priority AC.
484 	 */
485 	if (v_wme_ac > d_wme_ac)
486 		ac = v_wme_ac;
487 	else
488 		ac = d_wme_ac;
489 
490 	/*
491 	 * Apply ACM policy.
492 	 */
493 	if (ic->ic_opmode == IEEE80211_M_STA) {
494 		static const int acmap[4] = {
495 			WME_AC_BK,	/* WME_AC_BE */
496 			WME_AC_BK,	/* WME_AC_BK */
497 			WME_AC_BE,	/* WME_AC_VI */
498 			WME_AC_VI,	/* WME_AC_VO */
499 		};
500 		while (ac != WME_AC_BK &&
501 		    ic->ic_wme.wme_wmeBssChanParams.cap_wmeParams[ac].wmep_acm)
502 			ac = acmap[ac];
503 	}
504 done:
505 	M_WME_SETAC(m, ac);
506 	return 0;
507 }
508 
509 /*
510  * Insure there is sufficient contiguous space to encapsulate the
511  * 802.11 data frame.  If room isn't already there, arrange for it.
512  * Drivers and cipher modules assume we have done the necessary work
513  * and fail rudely if they don't find the space they need.
514  */
515 static struct mbuf *
516 ieee80211_mbuf_adjust(struct ieee80211com *ic, int hdrsize,
517 	struct ieee80211_key *key, struct mbuf *m)
518 {
519 #define	TO_BE_RECLAIMED	(sizeof(struct ether_header) - sizeof(struct llc))
520 	int needed_space = ic->ic_headroom + hdrsize;
521 
522 	if (key != NULL) {
523 		/* XXX belongs in crypto code? */
524 		needed_space += key->wk_cipher->ic_header;
525 		/* XXX frags */
526 		/*
527 		 * When crypto is being done in the host we must insure
528 		 * the data are writable for the cipher routines; clone
529 		 * a writable mbuf chain.
530 		 * XXX handle SWMIC specially
531 		 */
532 		if (key->wk_flags & (IEEE80211_KEY_SWCRYPT|IEEE80211_KEY_SWMIC)) {
533 			m = m_unshare(m, M_NOWAIT);
534 			if (m == NULL) {
535 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
536 				    "%s: cannot get writable mbuf\n", __func__);
537 				ic->ic_stats.is_tx_nobuf++; /* XXX new stat */
538 				return NULL;
539 			}
540 		}
541 	}
542 	/*
543 	 * We know we are called just before stripping an Ethernet
544 	 * header and prepending an LLC header.  This means we know
545 	 * there will be
546 	 *	sizeof(struct ether_header) - sizeof(struct llc)
547 	 * bytes recovered to which we need additional space for the
548 	 * 802.11 header and any crypto header.
549 	 */
550 	/* XXX check trailing space and copy instead? */
551 	if (M_LEADINGSPACE(m) < needed_space - TO_BE_RECLAIMED) {
552 		struct mbuf *n = m_gethdr(M_NOWAIT, m->m_type);
553 		if (n == NULL) {
554 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
555 			    "%s: cannot expand storage\n", __func__);
556 			ic->ic_stats.is_tx_nobuf++;
557 			m_freem(m);
558 			return NULL;
559 		}
560 		KASSERT(needed_space <= MHLEN,
561 		    ("not enough room, need %u got %zu\n", needed_space, MHLEN));
562 		/*
563 		 * Setup new mbuf to have leading space to prepend the
564 		 * 802.11 header and any crypto header bits that are
565 		 * required (the latter are added when the driver calls
566 		 * back to ieee80211_crypto_encap to do crypto encapsulation).
567 		 */
568 		/* NB: must be first 'cuz it clobbers m_data */
569 		m_move_pkthdr(n, m);
570 		n->m_len = 0;			/* NB: m_gethdr does not set */
571 		n->m_data += needed_space;
572 		/*
573 		 * Pull up Ethernet header to create the expected layout.
574 		 * We could use m_pullup but that's overkill (i.e. we don't
575 		 * need the actual data) and it cannot fail so do it inline
576 		 * for speed.
577 		 */
578 		/* NB: struct ether_header is known to be contiguous */
579 		n->m_len += sizeof(struct ether_header);
580 		m->m_len -= sizeof(struct ether_header);
581 		m->m_data += sizeof(struct ether_header);
582 		/*
583 		 * Replace the head of the chain.
584 		 */
585 		n->m_next = m;
586 		m = n;
587 	}
588 	return m;
589 #undef TO_BE_RECLAIMED
590 }
591 
592 /*
593  * Return the transmit key to use in sending a unicast frame.
594  * If a unicast key is set we use that.  When no unicast key is set
595  * we fall back to the default transmit key.
596  */
597 static __inline struct ieee80211_key *
598 ieee80211_crypto_getucastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
599 {
600 	if (IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
601 		if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
602 		    IEEE80211_KEY_UNDEFINED(&ic->ic_nw_keys[ic->ic_def_txkey]))
603 			return NULL;
604 		return &ic->ic_nw_keys[ic->ic_def_txkey];
605 	} else {
606 		return &ni->ni_ucastkey;
607 	}
608 }
609 
610 /*
611  * Return the transmit key to use in sending a multicast frame.
612  * Multicast traffic always uses the group key which is installed as
613  * the default tx key.
614  */
615 static __inline struct ieee80211_key *
616 ieee80211_crypto_getmcastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
617 {
618 	if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
619 	    IEEE80211_KEY_UNDEFINED(&ic->ic_nw_keys[ic->ic_def_txkey]))
620 		return NULL;
621 	return &ic->ic_nw_keys[ic->ic_def_txkey];
622 }
623 
624 /*
625  * Encapsulate an outbound data frame.  The mbuf chain is updated.
626  * If an error is encountered NULL is returned.  The caller is required
627  * to provide a node reference and pullup the ethernet header in the
628  * first mbuf.
629  */
630 struct mbuf *
631 ieee80211_encap(struct ieee80211com *ic, struct mbuf *m,
632 	struct ieee80211_node *ni)
633 {
634 	struct ether_header eh;
635 	struct ieee80211_frame *wh;
636 	struct ieee80211_key *key;
637 	struct llc *llc;
638 	int hdrsize, datalen, addqos, txfrag, isff;
639 
640 	/*
641 	 * Copy existing Ethernet header to a safe place.  The
642 	 * rest of the code assumes it's ok to strip it when
643 	 * reorganizing state for the final encapsulation.
644 	 */
645 	KASSERT(m->m_len >= sizeof(eh), ("no ethernet header!"));
646 	memcpy(&eh, mtod(m, caddr_t), sizeof(struct ether_header));
647 
648 	/*
649 	 * Insure space for additional headers.  First identify
650 	 * transmit key to use in calculating any buffer adjustments
651 	 * required.  This is also used below to do privacy
652 	 * encapsulation work.  Then calculate the 802.11 header
653 	 * size and any padding required by the driver.
654 	 *
655 	 * Note key may be NULL if we fall back to the default
656 	 * transmit key and that is not set.  In that case the
657 	 * buffer may not be expanded as needed by the cipher
658 	 * routines, but they will/should discard it.
659 	 */
660 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
661 		if (ic->ic_opmode == IEEE80211_M_STA ||
662 		    !IEEE80211_IS_MULTICAST(eh.ether_dhost))
663 			key = ieee80211_crypto_getucastkey(ic, ni);
664 		else
665 			key = ieee80211_crypto_getmcastkey(ic, ni);
666 		if (key == NULL && eh.ether_type != htons(ETHERTYPE_PAE)) {
667 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
668 			    "[%s] no default transmit key (%s) deftxkey %u\n",
669 			    ether_sprintf(eh.ether_dhost), __func__,
670 			    ic->ic_def_txkey);
671 			ic->ic_stats.is_tx_nodefkey++;
672 			goto bad;
673 		}
674 	} else
675 		key = NULL;
676 	/* XXX 4-address format */
677 	/*
678 	 * XXX Some ap's don't handle QoS-encapsulated EAPOL
679 	 * frames so suppress use.  This may be an issue if other
680 	 * ap's require all data frames to be QoS-encapsulated
681 	 * once negotiated in which case we'll need to make this
682 	 * configurable.
683 	 */
684 	addqos = (ni->ni_flags & (IEEE80211_NODE_QOS|IEEE80211_NODE_HT)) &&
685 		 eh.ether_type != htons(ETHERTYPE_PAE);
686 	if (addqos)
687 		hdrsize = sizeof(struct ieee80211_qosframe);
688 	else
689 		hdrsize = sizeof(struct ieee80211_frame);
690 	if (ic->ic_flags & IEEE80211_F_DATAPAD)
691 		hdrsize = roundup(hdrsize, sizeof(uint32_t));
692 
693 	if ((isff = m->m_flags & M_FF) != 0) {
694 		struct mbuf *m2;
695 		struct ether_header eh2;
696 
697 		/*
698 		 * Fast frame encapsulation.  There must be two packets
699 		 * chained with m_nextpkt.  We do header adjustment for
700 		 * each, add the tunnel encapsulation, and then concatenate
701 		 * the mbuf chains to form a single frame for transmission.
702 		 */
703 		m2 = m->m_nextpkt;
704 		if (m2 == NULL) {
705 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
706 				"%s: only one frame\n", __func__);
707 			goto bad;
708 		}
709 		m->m_nextpkt = NULL;
710 		/*
711 		 * Include fast frame headers in adjusting header
712 		 * layout; this allocates space according to what
713 		 * ieee80211_encap_fastframe will do.
714 		 */
715 		m = ieee80211_mbuf_adjust(ic,
716 			hdrsize + sizeof(struct llc) + sizeof(uint32_t) + 2 +
717 			    sizeof(struct ether_header),
718 			key, m);
719 		if (m == NULL) {
720 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
721 			m_freem(m2);
722 			goto bad;
723 		}
724 		/*
725 		 * Copy second frame's Ethernet header out of line
726 		 * and adjust for encapsulation headers.  Note that
727 		 * we make room for padding in case there isn't room
728 		 * at the end of first frame.
729 		 */
730 		KASSERT(m2->m_len >= sizeof(eh2), ("no ethernet header!"));
731 		memcpy(&eh2, mtod(m2, caddr_t), sizeof(struct ether_header));
732 		m2 = ieee80211_mbuf_adjust(ic,
733 			ATH_FF_MAX_HDR_PAD + sizeof(struct ether_header),
734 			NULL, m2);
735 		if (m2 == NULL) {
736 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
737 			goto bad;
738 		}
739 		m = ieee80211_encap_fastframe(ic, m, &eh, m2, &eh2);
740 		if (m == NULL)
741 			goto bad;
742 	} else {
743 		/*
744 		 * Normal frame.
745 		 */
746 		m = ieee80211_mbuf_adjust(ic, hdrsize, key, m);
747 		if (m == NULL) {
748 			/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
749 			goto bad;
750 		}
751 		/* NB: this could be optimized 'cuz of ieee80211_mbuf_adjust */
752 		m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
753 		llc = mtod(m, struct llc *);
754 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
755 		llc->llc_control = LLC_UI;
756 		llc->llc_snap.org_code[0] = 0;
757 		llc->llc_snap.org_code[1] = 0;
758 		llc->llc_snap.org_code[2] = 0;
759 		llc->llc_snap.ether_type = eh.ether_type;
760 	}
761 	datalen = m->m_pkthdr.len;		/* NB: w/o 802.11 header */
762 
763 	M_PREPEND(m, hdrsize, M_DONTWAIT);
764 	if (m == NULL) {
765 		ic->ic_stats.is_tx_nobuf++;
766 		goto bad;
767 	}
768 	wh = mtod(m, struct ieee80211_frame *);
769 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
770 	*(uint16_t *)wh->i_dur = 0;
771 	switch (ic->ic_opmode) {
772 	case IEEE80211_M_STA:
773 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
774 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
775 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
776 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
777 		break;
778 	case IEEE80211_M_IBSS:
779 	case IEEE80211_M_AHDEMO:
780 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
781 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
782 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
783 		/*
784 		 * NB: always use the bssid from ic_bss as the
785 		 *     neighbor's may be stale after an ibss merge
786 		 */
787 		IEEE80211_ADDR_COPY(wh->i_addr3, ic->ic_bss->ni_bssid);
788 		break;
789 	case IEEE80211_M_HOSTAP:
790 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
791 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
792 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
793 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
794 		break;
795 	case IEEE80211_M_MONITOR:
796 	case IEEE80211_M_WDS:
797 		goto bad;
798 	}
799 	if (m->m_flags & M_MORE_DATA)
800 		wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
801 	if (addqos) {
802 		struct ieee80211_qosframe *qwh =
803 			(struct ieee80211_qosframe *) wh;
804 		int ac, tid;
805 
806 		ac = M_WME_GETAC(m);
807 		/* map from access class/queue to 11e header priorty value */
808 		tid = WME_AC_TO_TID(ac);
809 		qwh->i_qos[0] = tid & IEEE80211_QOS_TID;
810 		/*
811 		 * Check if A-MPDU tx aggregation is setup or if we
812 		 * should try to enable it.  The sta must be associated
813 		 * with HT and A-MPDU enabled for use.  On the first
814 		 * frame that goes out We issue an ADDBA request and
815 		 * wait for a reply.  The frame being encapsulated
816 		 * will go out w/o using A-MPDU, or possibly it might
817 		 * be collected by the driver and held/retransmit.
818 		 * ieee80211_ampdu_request handles staggering requests
819 		 * in case the receiver NAK's us or we are otherwise
820 		 * unable to establish a BA stream.
821 		 */
822 		if ((ni->ni_flags & IEEE80211_NODE_HT) &&
823 		    (ic->ic_flags_ext & IEEE80211_FEXT_AMPDU_TX)) {
824 			struct ieee80211_tx_ampdu *tap = &ni->ni_tx_ampdu[ac];
825 
826 			if (IEEE80211_AMPDU_RUNNING(tap)) {
827 				/*
828 				 * Operational, mark frame for aggregation.
829 				 */
830 				qwh->i_qos[0] |= IEEE80211_QOS_ACKPOLICY_BA;
831 			} else if (!IEEE80211_AMPDU_REQUESTED(tap)) {
832 				/*
833 				 * Not negotiated yet, request service.
834 				 */
835 				ieee80211_ampdu_request(ni, tap);
836 			}
837 		}
838 		/* XXX works even when BA marked above */
839 		if (ic->ic_wme.wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy)
840 			qwh->i_qos[0] |= IEEE80211_QOS_ACKPOLICY_NOACK;
841 		qwh->i_qos[1] = 0;
842 		qwh->i_fc[0] |= IEEE80211_FC0_SUBTYPE_QOS;
843 
844 		*(uint16_t *)wh->i_seq =
845 		    htole16(ni->ni_txseqs[tid] << IEEE80211_SEQ_SEQ_SHIFT);
846 		ni->ni_txseqs[tid]++;
847 	} else {
848 		*(uint16_t *)wh->i_seq =
849 		    htole16(ni->ni_txseqs[IEEE80211_NONQOS_TID] << IEEE80211_SEQ_SEQ_SHIFT);
850 		ni->ni_txseqs[IEEE80211_NONQOS_TID]++;
851 	}
852 	/* check if xmit fragmentation is required */
853 	txfrag = (m->m_pkthdr.len > ic->ic_fragthreshold &&
854 	    !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
855 	    (ic->ic_caps & IEEE80211_C_TXFRAG) &&
856 	    !isff);		/* NB: don't fragment ff's */
857 	if (key != NULL) {
858 		/*
859 		 * IEEE 802.1X: send EAPOL frames always in the clear.
860 		 * WPA/WPA2: encrypt EAPOL keys when pairwise keys are set.
861 		 */
862 		if (eh.ether_type != htons(ETHERTYPE_PAE) ||
863 		    ((ic->ic_flags & IEEE80211_F_WPA) &&
864 		     (ic->ic_opmode == IEEE80211_M_STA ?
865 		      !IEEE80211_KEY_UNDEFINED(key) :
866 		      !IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)))) {
867 			wh->i_fc[1] |= IEEE80211_FC1_WEP;
868 			if (!ieee80211_crypto_enmic(ic, key, m, txfrag)) {
869 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
870 				    "[%s] enmic failed, discard frame\n",
871 				    ether_sprintf(eh.ether_dhost));
872 				ic->ic_stats.is_crypto_enmicfail++;
873 				goto bad;
874 			}
875 		}
876 	}
877 	/*
878 	 * NB: frag flags may leak from above; they should only
879 	 *     be set on return to the caller if we fragment at
880 	 *     the 802.11 layer.
881 	 */
882 	m->m_flags &= ~(M_FRAG | M_FIRSTFRAG);
883 	if (txfrag && !ieee80211_fragment(ic, m, hdrsize,
884 	    key != NULL ? key->wk_cipher->ic_header : 0, ic->ic_fragthreshold))
885 		goto bad;
886 
887 	IEEE80211_NODE_STAT(ni, tx_data);
888 	if (IEEE80211_IS_MULTICAST(wh->i_addr1))
889 		IEEE80211_NODE_STAT(ni, tx_mcast);
890 	else
891 		IEEE80211_NODE_STAT(ni, tx_ucast);
892 	IEEE80211_NODE_STAT_ADD(ni, tx_bytes, datalen);
893 
894 	return m;
895 bad:
896 	if (m != NULL)
897 		m_freem(m);
898 	return NULL;
899 }
900 
901 /*
902  * Do Ethernet-LLC encapsulation for each payload in a fast frame
903  * tunnel encapsulation.  The frame is assumed to have an Ethernet
904  * header at the front that must be stripped before prepending the
905  * LLC followed by the Ethernet header passed in (with an Ethernet
906  * type that specifies the payload size).
907  */
908 static struct mbuf *
909 ieee80211_encap1(struct ieee80211com *ic, struct mbuf *m,
910 	const struct ether_header *eh)
911 {
912 	struct llc *llc;
913 	uint16_t payload;
914 
915 	/* XXX optimize by combining m_adj+M_PREPEND */
916 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
917 	llc = mtod(m, struct llc *);
918 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
919 	llc->llc_control = LLC_UI;
920 	llc->llc_snap.org_code[0] = 0;
921 	llc->llc_snap.org_code[1] = 0;
922 	llc->llc_snap.org_code[2] = 0;
923 	llc->llc_snap.ether_type = eh->ether_type;
924 	payload = m->m_pkthdr.len;		/* NB: w/o Ethernet header */
925 
926 	M_PREPEND(m, sizeof(struct ether_header), M_DONTWAIT);
927 	if (m == NULL) {		/* XXX cannot happen */
928 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
929 			"%s: no space for ether_header\n", __func__);
930 		ic->ic_stats.is_tx_nobuf++;
931 		return NULL;
932 	}
933 	ETHER_HEADER_COPY(mtod(m, void *), eh);
934 	mtod(m, struct ether_header *)->ether_type = htons(payload);
935 	return m;
936 }
937 
938 /*
939  * Do fast frame tunnel encapsulation.  The two frames and
940  * Ethernet headers are supplied.  The caller is assumed to
941  * have arrange for space in the mbuf chains for encapsulating
942  * headers (to avoid major mbuf fragmentation).
943  *
944  * The encapsulated frame is returned or NULL if there is a
945  * problem (should not happen).
946  */
947 static struct mbuf *
948 ieee80211_encap_fastframe(struct ieee80211com *ic,
949 	struct mbuf *m1, const struct ether_header *eh1,
950 	struct mbuf *m2, const struct ether_header *eh2)
951 {
952 	struct llc *llc;
953 	struct mbuf *m;
954 	int pad;
955 
956 	/*
957 	 * First, each frame gets a standard encapsulation.
958 	 */
959 	m1 = ieee80211_encap1(ic, m1, eh1);
960 	if (m1 == NULL) {
961 		m_freem(m2);
962 		return NULL;
963 	}
964 	m2 = ieee80211_encap1(ic, m2, eh2);
965 	if (m2 == NULL) {
966 		m_freem(m1);
967 		return NULL;
968 	}
969 
970 	/*
971 	 * Pad leading frame to a 4-byte boundary.  If there
972 	 * is space at the end of the first frame, put it
973 	 * there; otherwise prepend to the front of the second
974 	 * frame.  We know doing the second will always work
975 	 * because we reserve space above.  We prefer appending
976 	 * as this typically has better DMA alignment properties.
977 	 */
978 	for (m = m1; m->m_next != NULL; m = m->m_next)
979 		;
980 	pad = roundup2(m1->m_pkthdr.len, 4) - m1->m_pkthdr.len;
981 	if (pad) {
982 		if (M_TRAILINGSPACE(m) < pad) {		/* prepend to second */
983 			m2->m_data -= pad;
984 			m2->m_len += pad;
985 			m2->m_pkthdr.len += pad;
986 		} else {				/* append to first */
987 			m->m_len += pad;
988 			m1->m_pkthdr.len += pad;
989 		}
990 	}
991 
992 	/*
993 	 * Now, stick 'em together and prepend the tunnel headers;
994 	 * first the Atheros tunnel header (all zero for now) and
995 	 * then a special fast frame LLC.
996 	 *
997 	 * XXX optimize by prepending together
998 	 */
999 	m->m_next = m2;			/* NB: last mbuf from above */
1000 	m1->m_pkthdr.len += m2->m_pkthdr.len;
1001 	M_PREPEND(m1, sizeof(uint32_t)+2, M_DONTWAIT);
1002 	if (m1 == NULL) {		/* XXX cannot happen */
1003 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
1004 			"%s: no space for tunnel header\n", __func__);
1005 		ic->ic_stats.is_tx_nobuf++;
1006 		return NULL;
1007 	}
1008 	memset(mtod(m1, void *), 0, sizeof(uint32_t)+2);
1009 
1010 	M_PREPEND(m1, sizeof(struct llc), M_DONTWAIT);
1011 	if (m1 == NULL) {		/* XXX cannot happen */
1012 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SUPERG,
1013 			"%s: no space for llc header\n", __func__);
1014 		ic->ic_stats.is_tx_nobuf++;
1015 		return NULL;
1016 	}
1017 	llc = mtod(m1, struct llc *);
1018 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
1019 	llc->llc_control = LLC_UI;
1020 	llc->llc_snap.org_code[0] = ATH_FF_SNAP_ORGCODE_0;
1021 	llc->llc_snap.org_code[1] = ATH_FF_SNAP_ORGCODE_1;
1022 	llc->llc_snap.org_code[2] = ATH_FF_SNAP_ORGCODE_2;
1023 	llc->llc_snap.ether_type = htons(ATH_FF_ETH_TYPE);
1024 
1025 	ic->ic_stats.is_ff_encap++;
1026 
1027 	return m1;
1028 }
1029 
1030 /*
1031  * Fragment the frame according to the specified mtu.
1032  * The size of the 802.11 header (w/o padding) is provided
1033  * so we don't need to recalculate it.  We create a new
1034  * mbuf for each fragment and chain it through m_nextpkt;
1035  * we might be able to optimize this by reusing the original
1036  * packet's mbufs but that is significantly more complicated.
1037  */
1038 static int
1039 ieee80211_fragment(struct ieee80211com *ic, struct mbuf *m0,
1040 	u_int hdrsize, u_int ciphdrsize, u_int mtu)
1041 {
1042 	struct ieee80211_frame *wh, *whf;
1043 	struct mbuf *m, *prev, *next;
1044 	u_int totalhdrsize, fragno, fragsize, off, remainder, payload;
1045 
1046 	KASSERT(m0->m_nextpkt == NULL, ("mbuf already chained?"));
1047 	KASSERT(m0->m_pkthdr.len > mtu,
1048 		("pktlen %u mtu %u", m0->m_pkthdr.len, mtu));
1049 
1050 	wh = mtod(m0, struct ieee80211_frame *);
1051 	/* NB: mark the first frag; it will be propagated below */
1052 	wh->i_fc[1] |= IEEE80211_FC1_MORE_FRAG;
1053 	totalhdrsize = hdrsize + ciphdrsize;
1054 	fragno = 1;
1055 	off = mtu - ciphdrsize;
1056 	remainder = m0->m_pkthdr.len - off;
1057 	prev = m0;
1058 	do {
1059 		fragsize = totalhdrsize + remainder;
1060 		if (fragsize > mtu)
1061 			fragsize = mtu;
1062 		KASSERT(fragsize < MCLBYTES,
1063 			("fragment size %u too big!", fragsize));
1064 		if (fragsize > MHLEN)
1065 			m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1066 		else
1067 			m = m_gethdr(M_DONTWAIT, MT_DATA);
1068 		if (m == NULL)
1069 			goto bad;
1070 		/* leave room to prepend any cipher header */
1071 		m_align(m, fragsize - ciphdrsize);
1072 
1073 		/*
1074 		 * Form the header in the fragment.  Note that since
1075 		 * we mark the first fragment with the MORE_FRAG bit
1076 		 * it automatically is propagated to each fragment; we
1077 		 * need only clear it on the last fragment (done below).
1078 		 */
1079 		whf = mtod(m, struct ieee80211_frame *);
1080 		memcpy(whf, wh, hdrsize);
1081 		*(uint16_t *)&whf->i_seq[0] |= htole16(
1082 			(fragno & IEEE80211_SEQ_FRAG_MASK) <<
1083 				IEEE80211_SEQ_FRAG_SHIFT);
1084 		fragno++;
1085 
1086 		payload = fragsize - totalhdrsize;
1087 		/* NB: destination is known to be contiguous */
1088 		m_copydata(m0, off, payload, mtod(m, uint8_t *) + hdrsize);
1089 		m->m_len = hdrsize + payload;
1090 		m->m_pkthdr.len = hdrsize + payload;
1091 		m->m_flags |= M_FRAG;
1092 
1093 		/* chain up the fragment */
1094 		prev->m_nextpkt = m;
1095 		prev = m;
1096 
1097 		/* deduct fragment just formed */
1098 		remainder -= payload;
1099 		off += payload;
1100 	} while (remainder != 0);
1101 	whf->i_fc[1] &= ~IEEE80211_FC1_MORE_FRAG;
1102 
1103 	/* strip first mbuf now that everything has been copied */
1104 	m_adj(m0, -(m0->m_pkthdr.len - (mtu - ciphdrsize)));
1105 	m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1106 
1107 	ic->ic_stats.is_tx_fragframes++;
1108 	ic->ic_stats.is_tx_frags += fragno-1;
1109 
1110 	return 1;
1111 bad:
1112 	/* reclaim fragments but leave original frame for caller to free */
1113 	for (m = m0->m_nextpkt; m != NULL; m = next) {
1114 		next = m->m_nextpkt;
1115 		m->m_nextpkt = NULL;		/* XXX paranoid */
1116 		m_freem(m);
1117 	}
1118 	m0->m_nextpkt = NULL;
1119 	return 0;
1120 }
1121 
1122 /*
1123  * Add a supported rates element id to a frame.
1124  */
1125 static uint8_t *
1126 ieee80211_add_rates(uint8_t *frm, const struct ieee80211_rateset *rs)
1127 {
1128 	int nrates;
1129 
1130 	*frm++ = IEEE80211_ELEMID_RATES;
1131 	nrates = rs->rs_nrates;
1132 	if (nrates > IEEE80211_RATE_SIZE)
1133 		nrates = IEEE80211_RATE_SIZE;
1134 	*frm++ = nrates;
1135 	memcpy(frm, rs->rs_rates, nrates);
1136 	return frm + nrates;
1137 }
1138 
1139 /*
1140  * Add an extended supported rates element id to a frame.
1141  */
1142 static uint8_t *
1143 ieee80211_add_xrates(uint8_t *frm, const struct ieee80211_rateset *rs)
1144 {
1145 	/*
1146 	 * Add an extended supported rates element if operating in 11g mode.
1147 	 */
1148 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
1149 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
1150 		*frm++ = IEEE80211_ELEMID_XRATES;
1151 		*frm++ = nrates;
1152 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
1153 		frm += nrates;
1154 	}
1155 	return frm;
1156 }
1157 
1158 /*
1159  * Add an ssid elemet to a frame.
1160  */
1161 static uint8_t *
1162 ieee80211_add_ssid(uint8_t *frm, const uint8_t *ssid, u_int len)
1163 {
1164 	*frm++ = IEEE80211_ELEMID_SSID;
1165 	*frm++ = len;
1166 	memcpy(frm, ssid, len);
1167 	return frm + len;
1168 }
1169 
1170 /*
1171  * Add an erp element to a frame.
1172  */
1173 static uint8_t *
1174 ieee80211_add_erp(uint8_t *frm, struct ieee80211com *ic)
1175 {
1176 	uint8_t erp;
1177 
1178 	*frm++ = IEEE80211_ELEMID_ERP;
1179 	*frm++ = 1;
1180 	erp = 0;
1181 	if (ic->ic_nonerpsta != 0)
1182 		erp |= IEEE80211_ERP_NON_ERP_PRESENT;
1183 	if (ic->ic_flags & IEEE80211_F_USEPROT)
1184 		erp |= IEEE80211_ERP_USE_PROTECTION;
1185 	if (ic->ic_flags & IEEE80211_F_USEBARKER)
1186 		erp |= IEEE80211_ERP_LONG_PREAMBLE;
1187 	*frm++ = erp;
1188 	return frm;
1189 }
1190 
1191 static uint8_t *
1192 ieee80211_setup_wpa_ie(struct ieee80211com *ic, uint8_t *ie)
1193 {
1194 #define	WPA_OUI_BYTES		0x00, 0x50, 0xf2
1195 #define	ADDSHORT(frm, v) do {			\
1196 	frm[0] = (v) & 0xff;			\
1197 	frm[1] = (v) >> 8;			\
1198 	frm += 2;				\
1199 } while (0)
1200 #define	ADDSELECTOR(frm, sel) do {		\
1201 	memcpy(frm, sel, 4);			\
1202 	frm += 4;				\
1203 } while (0)
1204 	static const uint8_t oui[4] = { WPA_OUI_BYTES, WPA_OUI_TYPE };
1205 	static const uint8_t cipher_suite[][4] = {
1206 		{ WPA_OUI_BYTES, WPA_CSE_WEP40 },	/* NB: 40-bit */
1207 		{ WPA_OUI_BYTES, WPA_CSE_TKIP },
1208 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX WRAP */
1209 		{ WPA_OUI_BYTES, WPA_CSE_CCMP },
1210 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1211 		{ WPA_OUI_BYTES, WPA_CSE_NULL },
1212 	};
1213 	static const uint8_t wep104_suite[4] =
1214 		{ WPA_OUI_BYTES, WPA_CSE_WEP104 };
1215 	static const uint8_t key_mgt_unspec[4] =
1216 		{ WPA_OUI_BYTES, WPA_ASE_8021X_UNSPEC };
1217 	static const uint8_t key_mgt_psk[4] =
1218 		{ WPA_OUI_BYTES, WPA_ASE_8021X_PSK };
1219 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1220 	uint8_t *frm = ie;
1221 	uint8_t *selcnt;
1222 
1223 	*frm++ = IEEE80211_ELEMID_VENDOR;
1224 	*frm++ = 0;				/* length filled in below */
1225 	memcpy(frm, oui, sizeof(oui));		/* WPA OUI */
1226 	frm += sizeof(oui);
1227 	ADDSHORT(frm, WPA_VERSION);
1228 
1229 	/* XXX filter out CKIP */
1230 
1231 	/* multicast cipher */
1232 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1233 	    rsn->rsn_mcastkeylen >= 13)
1234 		ADDSELECTOR(frm, wep104_suite);
1235 	else
1236 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1237 
1238 	/* unicast cipher list */
1239 	selcnt = frm;
1240 	ADDSHORT(frm, 0);			/* selector count */
1241 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1242 		selcnt[0]++;
1243 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1244 	}
1245 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1246 		selcnt[0]++;
1247 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1248 	}
1249 
1250 	/* authenticator selector list */
1251 	selcnt = frm;
1252 	ADDSHORT(frm, 0);			/* selector count */
1253 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1254 		selcnt[0]++;
1255 		ADDSELECTOR(frm, key_mgt_unspec);
1256 	}
1257 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1258 		selcnt[0]++;
1259 		ADDSELECTOR(frm, key_mgt_psk);
1260 	}
1261 
1262 	/* optional capabilities */
1263 	if (rsn->rsn_caps != 0 && rsn->rsn_caps != RSN_CAP_PREAUTH)
1264 		ADDSHORT(frm, rsn->rsn_caps);
1265 
1266 	/* calculate element length */
1267 	ie[1] = frm - ie - 2;
1268 	KASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1269 		("WPA IE too big, %u > %zu",
1270 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1271 	return frm;
1272 #undef ADDSHORT
1273 #undef ADDSELECTOR
1274 #undef WPA_OUI_BYTES
1275 }
1276 
1277 static uint8_t *
1278 ieee80211_setup_rsn_ie(struct ieee80211com *ic, uint8_t *ie)
1279 {
1280 #define	RSN_OUI_BYTES		0x00, 0x0f, 0xac
1281 #define	ADDSHORT(frm, v) do {			\
1282 	frm[0] = (v) & 0xff;			\
1283 	frm[1] = (v) >> 8;			\
1284 	frm += 2;				\
1285 } while (0)
1286 #define	ADDSELECTOR(frm, sel) do {		\
1287 	memcpy(frm, sel, 4);			\
1288 	frm += 4;				\
1289 } while (0)
1290 	static const uint8_t cipher_suite[][4] = {
1291 		{ RSN_OUI_BYTES, RSN_CSE_WEP40 },	/* NB: 40-bit */
1292 		{ RSN_OUI_BYTES, RSN_CSE_TKIP },
1293 		{ RSN_OUI_BYTES, RSN_CSE_WRAP },
1294 		{ RSN_OUI_BYTES, RSN_CSE_CCMP },
1295 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1296 		{ RSN_OUI_BYTES, RSN_CSE_NULL },
1297 	};
1298 	static const uint8_t wep104_suite[4] =
1299 		{ RSN_OUI_BYTES, RSN_CSE_WEP104 };
1300 	static const uint8_t key_mgt_unspec[4] =
1301 		{ RSN_OUI_BYTES, RSN_ASE_8021X_UNSPEC };
1302 	static const uint8_t key_mgt_psk[4] =
1303 		{ RSN_OUI_BYTES, RSN_ASE_8021X_PSK };
1304 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1305 	uint8_t *frm = ie;
1306 	uint8_t *selcnt;
1307 
1308 	*frm++ = IEEE80211_ELEMID_RSN;
1309 	*frm++ = 0;				/* length filled in below */
1310 	ADDSHORT(frm, RSN_VERSION);
1311 
1312 	/* XXX filter out CKIP */
1313 
1314 	/* multicast cipher */
1315 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1316 	    rsn->rsn_mcastkeylen >= 13)
1317 		ADDSELECTOR(frm, wep104_suite);
1318 	else
1319 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1320 
1321 	/* unicast cipher list */
1322 	selcnt = frm;
1323 	ADDSHORT(frm, 0);			/* selector count */
1324 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1325 		selcnt[0]++;
1326 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1327 	}
1328 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1329 		selcnt[0]++;
1330 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1331 	}
1332 
1333 	/* authenticator selector list */
1334 	selcnt = frm;
1335 	ADDSHORT(frm, 0);			/* selector count */
1336 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1337 		selcnt[0]++;
1338 		ADDSELECTOR(frm, key_mgt_unspec);
1339 	}
1340 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1341 		selcnt[0]++;
1342 		ADDSELECTOR(frm, key_mgt_psk);
1343 	}
1344 
1345 	/* optional capabilities */
1346 	ADDSHORT(frm, rsn->rsn_caps);
1347 	/* XXX PMKID */
1348 
1349 	/* calculate element length */
1350 	ie[1] = frm - ie - 2;
1351 	KASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1352 		("RSN IE too big, %u > %zu",
1353 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1354 	return frm;
1355 #undef ADDSELECTOR
1356 #undef ADDSHORT
1357 #undef RSN_OUI_BYTES
1358 }
1359 
1360 /*
1361  * Add a WPA/RSN element to a frame.
1362  */
1363 static uint8_t *
1364 ieee80211_add_wpa(uint8_t *frm, struct ieee80211com *ic)
1365 {
1366 
1367 	KASSERT(ic->ic_flags & IEEE80211_F_WPA, ("no WPA/RSN!"));
1368 	if (ic->ic_flags & IEEE80211_F_WPA2)
1369 		frm = ieee80211_setup_rsn_ie(ic, frm);
1370 	if (ic->ic_flags & IEEE80211_F_WPA1)
1371 		frm = ieee80211_setup_wpa_ie(ic, frm);
1372 	return frm;
1373 }
1374 
1375 #define	WME_OUI_BYTES		0x00, 0x50, 0xf2
1376 /*
1377  * Add a WME information element to a frame.
1378  */
1379 static uint8_t *
1380 ieee80211_add_wme_info(uint8_t *frm, struct ieee80211_wme_state *wme)
1381 {
1382 	static const struct ieee80211_wme_info info = {
1383 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1384 		.wme_len	= sizeof(struct ieee80211_wme_info) - 2,
1385 		.wme_oui	= { WME_OUI_BYTES },
1386 		.wme_type	= WME_OUI_TYPE,
1387 		.wme_subtype	= WME_INFO_OUI_SUBTYPE,
1388 		.wme_version	= WME_VERSION,
1389 		.wme_info	= 0,
1390 	};
1391 	memcpy(frm, &info, sizeof(info));
1392 	return frm + sizeof(info);
1393 }
1394 
1395 /*
1396  * Add a WME parameters element to a frame.
1397  */
1398 static uint8_t *
1399 ieee80211_add_wme_param(uint8_t *frm, struct ieee80211_wme_state *wme)
1400 {
1401 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
1402 #define	ADDSHORT(frm, v) do {			\
1403 	frm[0] = (v) & 0xff;			\
1404 	frm[1] = (v) >> 8;			\
1405 	frm += 2;				\
1406 } while (0)
1407 	/* NB: this works 'cuz a param has an info at the front */
1408 	static const struct ieee80211_wme_info param = {
1409 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1410 		.wme_len	= sizeof(struct ieee80211_wme_param) - 2,
1411 		.wme_oui	= { WME_OUI_BYTES },
1412 		.wme_type	= WME_OUI_TYPE,
1413 		.wme_subtype	= WME_PARAM_OUI_SUBTYPE,
1414 		.wme_version	= WME_VERSION,
1415 	};
1416 	int i;
1417 
1418 	memcpy(frm, &param, sizeof(param));
1419 	frm += __offsetof(struct ieee80211_wme_info, wme_info);
1420 	*frm++ = wme->wme_bssChanParams.cap_info;	/* AC info */
1421 	*frm++ = 0;					/* reserved field */
1422 	for (i = 0; i < WME_NUM_AC; i++) {
1423 		const struct wmeParams *ac =
1424 		       &wme->wme_bssChanParams.cap_wmeParams[i];
1425 		*frm++ = SM(i, WME_PARAM_ACI)
1426 		       | SM(ac->wmep_acm, WME_PARAM_ACM)
1427 		       | SM(ac->wmep_aifsn, WME_PARAM_AIFSN)
1428 		       ;
1429 		*frm++ = SM(ac->wmep_logcwmax, WME_PARAM_LOGCWMAX)
1430 		       | SM(ac->wmep_logcwmin, WME_PARAM_LOGCWMIN)
1431 		       ;
1432 		ADDSHORT(frm, ac->wmep_txopLimit);
1433 	}
1434 	return frm;
1435 #undef SM
1436 #undef ADDSHORT
1437 }
1438 #undef WME_OUI_BYTES
1439 
1440 #define	ATH_OUI_BYTES		0x00, 0x03, 0x7f
1441 /*
1442  * Add a WME information element to a frame.
1443  */
1444 static uint8_t *
1445 ieee80211_add_ath(uint8_t *frm, uint8_t caps, uint16_t defkeyix)
1446 {
1447 	static const struct ieee80211_ath_ie info = {
1448 		.ath_id		= IEEE80211_ELEMID_VENDOR,
1449 		.ath_len	= sizeof(struct ieee80211_ath_ie) - 2,
1450 		.ath_oui	= { ATH_OUI_BYTES },
1451 		.ath_oui_type	= ATH_OUI_TYPE,
1452 		.ath_oui_subtype= ATH_OUI_SUBTYPE,
1453 		.ath_version	= ATH_OUI_VERSION,
1454 	};
1455 	struct ieee80211_ath_ie *ath = (struct ieee80211_ath_ie *) frm;
1456 
1457 	memcpy(frm, &info, sizeof(info));
1458 	ath->ath_capability = caps;
1459 	ath->ath_defkeyix[0] = (defkeyix & 0xff);
1460 	ath->ath_defkeyix[1] = ((defkeyix >> 8) & 0xff);
1461 	return frm + sizeof(info);
1462 }
1463 #undef ATH_OUI_BYTES
1464 
1465 /*
1466  * Send a probe request frame with the specified ssid
1467  * and any optional information element data.
1468  */
1469 int
1470 ieee80211_send_probereq(struct ieee80211_node *ni,
1471 	const uint8_t sa[IEEE80211_ADDR_LEN],
1472 	const uint8_t da[IEEE80211_ADDR_LEN],
1473 	const uint8_t bssid[IEEE80211_ADDR_LEN],
1474 	const uint8_t *ssid, size_t ssidlen,
1475 	const void *optie, size_t optielen)
1476 {
1477 	struct ieee80211com *ic = ni->ni_ic;
1478 	struct ieee80211_frame *wh;
1479 	const struct ieee80211_rateset *rs;
1480 	struct mbuf *m;
1481 	uint8_t *frm;
1482 
1483 	/*
1484 	 * Hold a reference on the node so it doesn't go away until after
1485 	 * the xmit is complete all the way in the driver.  On error we
1486 	 * will remove our reference.
1487 	 */
1488 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1489 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1490 		__func__, __LINE__,
1491 		ni, ether_sprintf(ni->ni_macaddr),
1492 		ieee80211_node_refcnt(ni)+1);
1493 	ieee80211_ref_node(ni);
1494 
1495 	/*
1496 	 * prreq frame format
1497 	 *	[tlv] ssid
1498 	 *	[tlv] supported rates
1499 	 *	[tlv] extended supported rates
1500 	 *	[tlv] user-specified ie's
1501 	 */
1502 	m = ieee80211_getmgtframe(&frm,
1503 		 ic->ic_headroom + sizeof(struct ieee80211_frame),
1504 		 2 + IEEE80211_NWID_LEN
1505 	       + 2 + IEEE80211_RATE_SIZE
1506 	       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1507 	       + (optie != NULL ? optielen : 0)
1508 	);
1509 	if (m == NULL) {
1510 		ic->ic_stats.is_tx_nobuf++;
1511 		ieee80211_free_node(ni);
1512 		return ENOMEM;
1513 	}
1514 
1515 	frm = ieee80211_add_ssid(frm, ssid, ssidlen);
1516 	rs = ieee80211_get_suprates(ic, ic->ic_curchan);
1517 	frm = ieee80211_add_rates(frm, rs);
1518 	frm = ieee80211_add_xrates(frm, rs);
1519 
1520 	if (optie != NULL) {
1521 		memcpy(frm, optie, optielen);
1522 		frm += optielen;
1523 	}
1524 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1525 
1526 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1527 	if (m == NULL)
1528 		return ENOMEM;
1529 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
1530 	m->m_pkthdr.rcvif = (void *)ni;
1531 
1532 	wh = mtod(m, struct ieee80211_frame *);
1533 	ieee80211_send_setup(ic, ni, wh,
1534 		IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_PROBE_REQ,
1535 		sa, da, bssid);
1536 	/* XXX power management? */
1537 
1538 	IEEE80211_NODE_STAT(ni, tx_probereq);
1539 	IEEE80211_NODE_STAT(ni, tx_mgmt);
1540 
1541 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
1542 	    "[%s] send probe req on channel %u\n",
1543 	    ether_sprintf(wh->i_addr1),
1544 	    ieee80211_chan2ieee(ic, ic->ic_curchan));
1545 
1546 	IF_ENQUEUE(&ic->ic_mgtq, m);
1547 	if_start(ic->ic_ifp);
1548 	return 0;
1549 }
1550 
1551 /*
1552  * Calculate capability information for mgt frames.
1553  */
1554 static uint16_t
1555 getcapinfo(struct ieee80211com *ic, struct ieee80211_channel *chan)
1556 {
1557 	uint16_t capinfo;
1558 
1559 	KASSERT(ic->ic_opmode != IEEE80211_M_STA, ("station mode"));
1560 
1561 	if (ic->ic_opmode == IEEE80211_M_HOSTAP)
1562 		capinfo = IEEE80211_CAPINFO_ESS;
1563 	else if (ic->ic_opmode == IEEE80211_M_IBSS)
1564 		capinfo = IEEE80211_CAPINFO_IBSS;
1565 	else
1566 		capinfo = 0;
1567 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1568 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1569 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1570 	    IEEE80211_IS_CHAN_2GHZ(chan))
1571 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1572 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1573 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1574 	return capinfo;
1575 }
1576 
1577 /*
1578  * Send a management frame.  The node is for the destination (or ic_bss
1579  * when in station mode).  Nodes other than ic_bss have their reference
1580  * count bumped to reflect our use for an indeterminant time.
1581  */
1582 int
1583 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
1584 	int type, int arg)
1585 {
1586 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
1587 	struct mbuf *m;
1588 	uint8_t *frm;
1589 	uint16_t capinfo;
1590 	int has_challenge, is_shared_key, ret, status;
1591 
1592 	KASSERT(ni != NULL, ("null node"));
1593 
1594 	/*
1595 	 * Hold a reference on the node so it doesn't go away until after
1596 	 * the xmit is complete all the way in the driver.  On error we
1597 	 * will remove our reference.
1598 	 */
1599 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1600 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1601 		__func__, __LINE__,
1602 		ni, ether_sprintf(ni->ni_macaddr),
1603 		ieee80211_node_refcnt(ni)+1);
1604 	ieee80211_ref_node(ni);
1605 
1606 	switch (type) {
1607 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1608 		/*
1609 		 * probe response frame format
1610 		 *	[8] time stamp
1611 		 *	[2] beacon interval
1612 		 *	[2] cabability information
1613 		 *	[tlv] ssid
1614 		 *	[tlv] supported rates
1615 		 *	[tlv] parameter set (FH/DS)
1616 		 *	[tlv] parameter set (IBSS)
1617 		 *	[tlv] extended rate phy (ERP)
1618 		 *	[tlv] extended supported rates
1619 		 *	[tlv] WPA
1620 		 *	[tlv] WME (optional)
1621 		 *	[tlv] HT capabilities
1622 		 *	[tlv] HT information
1623 		 *	[tlv] Vendor OUI HT capabilities (optional)
1624 		 *	[tlv] Vendor OUI HT information (optional)
1625 		 *	[tlv] Atheros capabilities
1626 		 */
1627 		m = ieee80211_getmgtframe(&frm,
1628 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1629 			 8
1630 		       + sizeof(uint16_t)
1631 		       + sizeof(uint16_t)
1632 		       + 2 + IEEE80211_NWID_LEN
1633 		       + 2 + IEEE80211_RATE_SIZE
1634 		       + 7	/* max(7,3) */
1635 		       + 6
1636 		       + 3
1637 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1638 		       /* XXX !WPA1+WPA2 fits w/o a cluster */
1639 		       + (ic->ic_flags & IEEE80211_F_WPA ?
1640 				2*sizeof(struct ieee80211_ie_wpa) : 0)
1641 		       + sizeof(struct ieee80211_wme_param)
1642 		       /* XXX check for cluster requirement */
1643 		       + 2*sizeof(struct ieee80211_ie_htcap) + 4
1644 		       + 2*sizeof(struct ieee80211_ie_htinfo) + 4
1645 		       + sizeof(struct ieee80211_ath_ie)
1646 		);
1647 		if (m == NULL)
1648 			senderr(ENOMEM, is_tx_nobuf);
1649 
1650 		memset(frm, 0, 8);	/* timestamp should be filled later */
1651 		frm += 8;
1652 		*(uint16_t *)frm = htole16(ic->ic_bss->ni_intval);
1653 		frm += 2;
1654 		capinfo = getcapinfo(ic, ic->ic_curchan);
1655 		*(uint16_t *)frm = htole16(capinfo);
1656 		frm += 2;
1657 
1658 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
1659 				ic->ic_bss->ni_esslen);
1660 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1661 
1662 		if (IEEE80211_IS_CHAN_FHSS(ic->ic_curchan)) {
1663                         *frm++ = IEEE80211_ELEMID_FHPARMS;
1664                         *frm++ = 5;
1665                         *frm++ = ni->ni_fhdwell & 0x00ff;
1666                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
1667                         *frm++ = IEEE80211_FH_CHANSET(
1668 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1669                         *frm++ = IEEE80211_FH_CHANPAT(
1670 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1671                         *frm++ = ni->ni_fhindex;
1672 		} else {
1673 			*frm++ = IEEE80211_ELEMID_DSPARMS;
1674 			*frm++ = 1;
1675 			*frm++ = ieee80211_chan2ieee(ic, ic->ic_curchan);
1676 		}
1677 
1678 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
1679 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1680 			*frm++ = 2;
1681 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1682 		}
1683 		if (ic->ic_flags & IEEE80211_F_WPA)
1684 			frm = ieee80211_add_wpa(frm, ic);
1685 		if (IEEE80211_IS_CHAN_ANYG(ic->ic_curchan))
1686 			frm = ieee80211_add_erp(frm, ic);
1687 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1688 		if (ic->ic_flags & IEEE80211_F_WME)
1689 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1690 		if (IEEE80211_IS_CHAN_HT(ic->ic_curchan)) {
1691 			frm = ieee80211_add_htcap(frm, ni);
1692 			frm = ieee80211_add_htinfo(frm, ni);
1693 			if (ic->ic_flags_ext & IEEE80211_FEXT_HTCOMPAT) {
1694 				frm = ieee80211_add_htcap_vendor(frm, ni);
1695 				frm = ieee80211_add_htinfo_vendor(frm, ni);
1696 			}
1697 		}
1698 		if (ni->ni_ath_ie != NULL)
1699 			frm = ieee80211_add_ath(frm, ni->ni_ath_flags,
1700 				ni->ni_ath_defkeyix);
1701 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1702 		break;
1703 
1704 	case IEEE80211_FC0_SUBTYPE_AUTH:
1705 		status = arg >> 16;
1706 		arg &= 0xffff;
1707 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
1708 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
1709 		    ni->ni_challenge != NULL);
1710 
1711 		/*
1712 		 * Deduce whether we're doing open authentication or
1713 		 * shared key authentication.  We do the latter if
1714 		 * we're in the middle of a shared key authentication
1715 		 * handshake or if we're initiating an authentication
1716 		 * request and configured to use shared key.
1717 		 */
1718 		is_shared_key = has_challenge ||
1719 		     arg >= IEEE80211_AUTH_SHARED_RESPONSE ||
1720 		     (arg == IEEE80211_AUTH_SHARED_REQUEST &&
1721 		      ic->ic_bss->ni_authmode == IEEE80211_AUTH_SHARED);
1722 
1723 		m = ieee80211_getmgtframe(&frm,
1724 			  ic->ic_headroom + sizeof(struct ieee80211_frame),
1725 			  3 * sizeof(uint16_t)
1726 			+ (has_challenge && status == IEEE80211_STATUS_SUCCESS ?
1727 				sizeof(uint16_t)+IEEE80211_CHALLENGE_LEN : 0)
1728 		);
1729 		if (m == NULL)
1730 			senderr(ENOMEM, is_tx_nobuf);
1731 
1732 		((uint16_t *)frm)[0] =
1733 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
1734 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
1735 		((uint16_t *)frm)[1] = htole16(arg);	/* sequence number */
1736 		((uint16_t *)frm)[2] = htole16(status);/* status */
1737 
1738 		if (has_challenge && status == IEEE80211_STATUS_SUCCESS) {
1739 			((uint16_t *)frm)[3] =
1740 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
1741 			    IEEE80211_ELEMID_CHALLENGE);
1742 			memcpy(&((uint16_t *)frm)[4], ni->ni_challenge,
1743 			    IEEE80211_CHALLENGE_LEN);
1744 			m->m_pkthdr.len = m->m_len =
1745 				4 * sizeof(uint16_t) + IEEE80211_CHALLENGE_LEN;
1746 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
1747 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1748 				    "[%s] request encrypt frame (%s)\n",
1749 				    ether_sprintf(ni->ni_macaddr), __func__);
1750 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
1751 			}
1752 		} else
1753 			m->m_pkthdr.len = m->m_len = 3 * sizeof(uint16_t);
1754 
1755 		/* XXX not right for shared key */
1756 		if (status == IEEE80211_STATUS_SUCCESS)
1757 			IEEE80211_NODE_STAT(ni, tx_auth);
1758 		else
1759 			IEEE80211_NODE_STAT(ni, tx_auth_fail);
1760 
1761 		if (ic->ic_opmode == IEEE80211_M_STA)
1762 			ieee80211_add_callback(m, ieee80211_tx_mgt_cb,
1763 				(void *) ic->ic_state);
1764 		break;
1765 
1766 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
1767 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1768 			"[%s] send station deauthenticate (reason %d)\n",
1769 			ether_sprintf(ni->ni_macaddr), arg);
1770 		m = ieee80211_getmgtframe(&frm,
1771 			ic->ic_headroom + sizeof(struct ieee80211_frame),
1772 			sizeof(uint16_t));
1773 		if (m == NULL)
1774 			senderr(ENOMEM, is_tx_nobuf);
1775 		*(uint16_t *)frm = htole16(arg);	/* reason */
1776 		m->m_pkthdr.len = m->m_len = sizeof(uint16_t);
1777 
1778 		IEEE80211_NODE_STAT(ni, tx_deauth);
1779 		IEEE80211_NODE_STAT_SET(ni, tx_deauth_code, arg);
1780 
1781 		ieee80211_node_unauthorize(ni);		/* port closed */
1782 		break;
1783 
1784 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1785 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1786 		/*
1787 		 * asreq frame format
1788 		 *	[2] capability information
1789 		 *	[2] listen interval
1790 		 *	[6*] current AP address (reassoc only)
1791 		 *	[tlv] ssid
1792 		 *	[tlv] supported rates
1793 		 *	[tlv] extended supported rates
1794 		 *	[tlv] WME
1795 		 *	[tlv] HT capabilities
1796 		 *	[tlv] Vendor OUI HT capabilities (optional)
1797 		 *	[tlv] Atheros capabilities (if negotiated)
1798 		 *	[tlv] user-specified ie's
1799 		 */
1800 		m = ieee80211_getmgtframe(&frm,
1801 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1802 			 sizeof(uint16_t)
1803 		       + sizeof(uint16_t)
1804 		       + IEEE80211_ADDR_LEN
1805 		       + 2 + IEEE80211_NWID_LEN
1806 		       + 2 + IEEE80211_RATE_SIZE
1807 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1808 		       + sizeof(struct ieee80211_wme_info)
1809 		       + 2*sizeof(struct ieee80211_ie_htcap) + 4
1810 		       + sizeof(struct ieee80211_ath_ie)
1811 		       + (ic->ic_opt_ie != NULL ? ic->ic_opt_ie_len : 0)
1812 		);
1813 		if (m == NULL)
1814 			senderr(ENOMEM, is_tx_nobuf);
1815 
1816 		KASSERT(ic->ic_opmode == IEEE80211_M_STA,
1817 		    ("wrong mode %u", ic->ic_opmode));
1818 		capinfo = IEEE80211_CAPINFO_ESS;
1819 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1820 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1821 		/*
1822 		 * NB: Some 11a AP's reject the request when
1823 		 *     short premable is set.
1824 		 */
1825 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1826 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1827 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1828 		if (IEEE80211_IS_CHAN_ANYG(ic->ic_curchan) &&
1829 		    (ic->ic_caps & IEEE80211_C_SHSLOT))
1830 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1831 		*(uint16_t *)frm = htole16(capinfo);
1832 		frm += 2;
1833 
1834 		KASSERT(ic->ic_bss->ni_intval != 0,
1835 			("beacon interval is zero!"));
1836 		*(uint16_t *)frm = htole16(howmany(ic->ic_lintval,
1837 						   ic->ic_bss->ni_intval));
1838 		frm += 2;
1839 
1840 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
1841 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
1842 			frm += IEEE80211_ADDR_LEN;
1843 		}
1844 
1845 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
1846 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1847 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1848 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1849 			frm = ieee80211_add_wme_info(frm, &ic->ic_wme);
1850 		if (IEEE80211_IS_CHAN_HT(ic->ic_curchan)) {
1851 			frm = ieee80211_add_htcap(frm, ni);
1852 			if (ic->ic_flags_ext & IEEE80211_FEXT_HTCOMPAT)
1853 				frm = ieee80211_add_htcap_vendor(frm, ni);
1854 		}
1855 		if (IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS))
1856 			frm = ieee80211_add_ath(frm,
1857 				IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS),
1858 				(ic->ic_flags & IEEE80211_F_WPA) == 0 &&
1859 				ni->ni_authmode != IEEE80211_AUTH_8021X &&
1860 				ic->ic_def_txkey != IEEE80211_KEYIX_NONE ?
1861 				ic->ic_def_txkey : 0x7fff);
1862 		if (ic->ic_opt_ie != NULL) {
1863 			memcpy(frm, ic->ic_opt_ie, ic->ic_opt_ie_len);
1864 			frm += ic->ic_opt_ie_len;
1865 		}
1866 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1867 
1868 		ieee80211_add_callback(m, ieee80211_tx_mgt_cb,
1869 			(void *) ic->ic_state);
1870 		break;
1871 
1872 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1873 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1874 		/*
1875 		 * asresp frame format
1876 		 *	[2] capability information
1877 		 *	[2] status
1878 		 *	[2] association ID
1879 		 *	[tlv] supported rates
1880 		 *	[tlv] extended supported rates
1881 		 *	[tlv] WME (if enabled and STA enabled)
1882 		 *	[tlv] HT capabilities (standard or vendor OUI)
1883 		 *	[tlv] HT information (standard or vendor OUI)
1884 		 *	[tlv] Atheros capabilities (if enabled and STA enabled)
1885 		 */
1886 		m = ieee80211_getmgtframe(&frm,
1887 			 ic->ic_headroom + sizeof(struct ieee80211_frame),
1888 			 sizeof(uint16_t)
1889 		       + sizeof(uint16_t)
1890 		       + sizeof(uint16_t)
1891 		       + 2 + IEEE80211_RATE_SIZE
1892 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1893 		       + sizeof(struct ieee80211_wme_param)
1894 		       + sizeof(struct ieee80211_ie_htcap) + 4
1895 		       + sizeof(struct ieee80211_ie_htinfo) + 4
1896 		       + sizeof(struct ieee80211_ath_ie)
1897 		);
1898 		if (m == NULL)
1899 			senderr(ENOMEM, is_tx_nobuf);
1900 
1901 		capinfo = getcapinfo(ic, ic->ic_curchan);
1902 		*(uint16_t *)frm = htole16(capinfo);
1903 		frm += 2;
1904 
1905 		*(uint16_t *)frm = htole16(arg);	/* status */
1906 		frm += 2;
1907 
1908 		if (arg == IEEE80211_STATUS_SUCCESS) {
1909 			*(uint16_t *)frm = htole16(ni->ni_associd);
1910 			IEEE80211_NODE_STAT(ni, tx_assoc);
1911 		} else
1912 			IEEE80211_NODE_STAT(ni, tx_assoc_fail);
1913 		frm += 2;
1914 
1915 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1916 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1917 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1918 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1919 		if (IEEE80211_IS_CHAN_HT(ic->ic_curchan)) {
1920 			/* NB: respond according to what we received */
1921 			if (ni->ni_flags & IEEE80211_NODE_HTCOMPAT) {
1922 				frm = ieee80211_add_htcap_vendor(frm, ni);
1923 				frm = ieee80211_add_htinfo_vendor(frm, ni);
1924 			} else {
1925 				frm = ieee80211_add_htcap(frm, ni);
1926 				frm = ieee80211_add_htinfo(frm, ni);
1927 			}
1928 		}
1929 		if (IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS))
1930 			frm = ieee80211_add_ath(frm,
1931 				IEEE80211_ATH_CAP(ic, ni, IEEE80211_F_ATHEROS),
1932 				ni->ni_ath_defkeyix);
1933 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1934 		break;
1935 
1936 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
1937 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1938 			"[%s] send station disassociate (reason %d)\n",
1939 			ether_sprintf(ni->ni_macaddr), arg);
1940 		m = ieee80211_getmgtframe(&frm,
1941 			ic->ic_headroom + sizeof(struct ieee80211_frame),
1942 			sizeof(uint16_t));
1943 		if (m == NULL)
1944 			senderr(ENOMEM, is_tx_nobuf);
1945 		*(uint16_t *)frm = htole16(arg);	/* reason */
1946 		m->m_pkthdr.len = m->m_len = sizeof(uint16_t);
1947 
1948 		IEEE80211_NODE_STAT(ni, tx_disassoc);
1949 		IEEE80211_NODE_STAT_SET(ni, tx_disassoc_code, arg);
1950 		break;
1951 
1952 	default:
1953 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1954 			"[%s] invalid mgmt frame type %u\n",
1955 			ether_sprintf(ni->ni_macaddr), type);
1956 		senderr(EINVAL, is_tx_unknownmgt);
1957 		/* NOTREACHED */
1958 	}
1959 
1960 	ret = ieee80211_mgmt_output(ic, ni, m, type);
1961 	if (ret != 0)
1962 		goto bad;
1963 	return 0;
1964 bad:
1965 	ieee80211_free_node(ni);
1966 	return ret;
1967 #undef senderr
1968 }
1969 
1970 static void
1971 ieee80211_tx_mgt_timeout(void *arg)
1972 {
1973 	struct ieee80211_node *ni = arg;
1974 	struct ieee80211com *ic	= ni->ni_ic;
1975 
1976 	if (ic->ic_state != IEEE80211_S_INIT &&
1977 	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
1978 		/*
1979 		 * NB: it's safe to specify a timeout as the reason here;
1980 		 *     it'll only be used in the right state.
1981 		 */
1982 		ieee80211_new_state(ic, IEEE80211_S_SCAN,
1983 			IEEE80211_SCAN_FAIL_TIMEOUT);
1984 	}
1985 }
1986 
1987 static void
1988 ieee80211_tx_mgt_cb(struct ieee80211_node *ni, void *arg, int status)
1989 {
1990 	struct ieee80211com *ic = ni->ni_ic;
1991 	enum ieee80211_state ostate = (enum ieee80211_state) arg;
1992 
1993 	/*
1994 	 * Frame transmit completed; arrange timer callback.  If
1995 	 * transmit was successfuly we wait for response.  Otherwise
1996 	 * we arrange an immediate callback instead of doing the
1997 	 * callback directly since we don't know what state the driver
1998 	 * is in (e.g. what locks it is holding).  This work should
1999 	 * not be too time-critical and not happen too often so the
2000 	 * added overhead is acceptable.
2001 	 *
2002 	 * XXX what happens if !acked but response shows up before callback?
2003 	 */
2004 	if (ic->ic_state == ostate)
2005 		callout_reset(&ic->ic_mgtsend,
2006 			status == 0 ? IEEE80211_TRANS_WAIT*hz : 0,
2007 			ieee80211_tx_mgt_timeout, ni);
2008 }
2009 
2010 /*
2011  * Allocate a beacon frame and fillin the appropriate bits.
2012  */
2013 struct mbuf *
2014 ieee80211_beacon_alloc(struct ieee80211_node *ni,
2015 	struct ieee80211_beacon_offsets *bo)
2016 {
2017 	struct ieee80211com *ic = ni->ni_ic;
2018 	struct ifnet *ifp = ic->ic_ifp;
2019 	struct ieee80211_frame *wh;
2020 	struct mbuf *m;
2021 	int pktlen;
2022 	uint8_t *frm;
2023 	uint16_t capinfo;
2024 	struct ieee80211_rateset *rs;
2025 
2026 	/*
2027 	 * beacon frame format
2028 	 *	[8] time stamp
2029 	 *	[2] beacon interval
2030 	 *	[2] cabability information
2031 	 *	[tlv] ssid
2032 	 *	[tlv] supported rates
2033 	 *	[3] parameter set (DS)
2034 	 *	[tlv] parameter set (IBSS/TIM)
2035 	 *	[tlv] country code
2036 	 *	[tlv] extended rate phy (ERP)
2037 	 *	[tlv] extended supported rates
2038 	 *	[tlv] WME parameters
2039 	 *	[tlv] WPA/RSN parameters
2040 	 *	[tlv] HT capabilities
2041 	 *	[tlv] HT information
2042 	 *	[tlv] Vendor OUI HT capabilities (optional)
2043 	 *	[tlv] Vendor OUI HT information (optional)
2044 	 * XXX Vendor-specific OIDs (e.g. Atheros)
2045 	 * NB: we allocate the max space required for the TIM bitmap.
2046 	 */
2047 	rs = &ni->ni_rates;
2048 	pktlen =   8					/* time stamp */
2049 		 + sizeof(uint16_t)			/* beacon interval */
2050 		 + sizeof(uint16_t)			/* capabilities */
2051 		 + 2 + ni->ni_esslen			/* ssid */
2052 	         + 2 + IEEE80211_RATE_SIZE		/* supported rates */
2053 	         + 2 + 1				/* DS parameters */
2054 		 + 2 + 4 + ic->ic_tim_len		/* DTIM/IBSSPARMS */
2055 		 + sizeof(struct ieee80211_country_ie)	/* country code */
2056 		 + 2 + 1				/* ERP */
2057 	         + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
2058 		 + (ic->ic_caps & IEEE80211_C_WME ?	/* WME */
2059 			sizeof(struct ieee80211_wme_param) : 0)
2060 		 + (ic->ic_caps & IEEE80211_C_WPA ?	/* WPA 1+2 */
2061 			2*sizeof(struct ieee80211_ie_wpa) : 0)
2062 		 /* XXX conditional? */
2063 		 + 4+2*sizeof(struct ieee80211_ie_htcap)/* HT caps */
2064 		 + 4+2*sizeof(struct ieee80211_ie_htinfo)/* HT info */
2065 		 ;
2066 	m = ieee80211_getmgtframe(&frm,
2067 		ic->ic_headroom + sizeof(struct ieee80211_frame), pktlen);
2068 	if (m == NULL) {
2069 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
2070 			"%s: cannot get buf; size %u\n", __func__, pktlen);
2071 		ic->ic_stats.is_tx_nobuf++;
2072 		return NULL;
2073 	}
2074 
2075 	memset(frm, 0, 8);	/* XXX timestamp is set by hardware/driver */
2076 	frm += 8;
2077 	*(uint16_t *)frm = htole16(ni->ni_intval);
2078 	frm += 2;
2079 	capinfo = getcapinfo(ic, ni->ni_chan);
2080 	bo->bo_caps = (uint16_t *)frm;
2081 	*(uint16_t *)frm = htole16(capinfo);
2082 	frm += 2;
2083 	*frm++ = IEEE80211_ELEMID_SSID;
2084 	if ((ic->ic_flags & IEEE80211_F_HIDESSID) == 0) {
2085 		*frm++ = ni->ni_esslen;
2086 		memcpy(frm, ni->ni_essid, ni->ni_esslen);
2087 		frm += ni->ni_esslen;
2088 	} else
2089 		*frm++ = 0;
2090 	frm = ieee80211_add_rates(frm, rs);
2091 	if (!IEEE80211_IS_CHAN_FHSS(ic->ic_bsschan)) {
2092 		*frm++ = IEEE80211_ELEMID_DSPARMS;
2093 		*frm++ = 1;
2094 		*frm++ = ieee80211_chan2ieee(ic, ic->ic_bsschan);
2095 	}
2096 	bo->bo_tim = frm;
2097 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
2098 		*frm++ = IEEE80211_ELEMID_IBSSPARMS;
2099 		*frm++ = 2;
2100 		*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
2101 		bo->bo_tim_len = 0;
2102 	} else if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
2103 		struct ieee80211_tim_ie *tie = (struct ieee80211_tim_ie *) frm;
2104 
2105 		tie->tim_ie = IEEE80211_ELEMID_TIM;
2106 		tie->tim_len = 4;	/* length */
2107 		tie->tim_count = 0;	/* DTIM count */
2108 		tie->tim_period = ic->ic_dtim_period;	/* DTIM period */
2109 		tie->tim_bitctl = 0;	/* bitmap control */
2110 		tie->tim_bitmap[0] = 0;	/* Partial Virtual Bitmap */
2111 		frm += sizeof(struct ieee80211_tim_ie);
2112 		bo->bo_tim_len = 1;
2113 	}
2114 	bo->bo_tim_trailer = frm;
2115 	if (ic->ic_flags & IEEE80211_F_DOTH)
2116 		frm = ieee80211_add_countryie(frm, ic,
2117 			ic->ic_countrycode, ic->ic_location);
2118 	if (ic->ic_flags & IEEE80211_F_WME) {
2119 		bo->bo_wme = frm;
2120 		frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
2121 	} else
2122 		bo->bo_wme = NULL;
2123 	if (ic->ic_flags & IEEE80211_F_WPA)
2124 		frm = ieee80211_add_wpa(frm, ic);
2125 	if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan)) {
2126 		bo->bo_erp = frm;
2127 		frm = ieee80211_add_erp(frm, ic);
2128 	} else
2129 		bo->bo_erp = NULL;
2130 	frm = ieee80211_add_xrates(frm, rs);
2131 	if (IEEE80211_IS_CHAN_HT(ic->ic_bsschan)) {
2132 		frm = ieee80211_add_htcap(frm, ni);
2133 		bo->bo_htinfo = frm;
2134 		frm = ieee80211_add_htinfo(frm, ni);
2135 		if (ic->ic_flags_ext & IEEE80211_FEXT_HTCOMPAT) {
2136 			frm = ieee80211_add_htcap_vendor(frm, ni);
2137 			frm = ieee80211_add_htinfo_vendor(frm, ni);
2138 		}
2139 	} else
2140 		bo->bo_htinfo = NULL;
2141 	bo->bo_tim_trailer_len = frm - bo->bo_tim_trailer;
2142 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
2143 
2144 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
2145 	KASSERT(m != NULL, ("no space for 802.11 header?"));
2146 	wh = mtod(m, struct ieee80211_frame *);
2147 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
2148 	    IEEE80211_FC0_SUBTYPE_BEACON;
2149 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
2150 	*(uint16_t *)wh->i_dur = 0;
2151 	IEEE80211_ADDR_COPY(wh->i_addr1, ifp->if_broadcastaddr);
2152 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
2153 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
2154 	*(uint16_t *)wh->i_seq = 0;
2155 
2156 	return m;
2157 }
2158 
2159 /*
2160  * Update the dynamic parts of a beacon frame based on the current state.
2161  */
2162 int
2163 ieee80211_beacon_update(struct ieee80211_node *ni,
2164 	struct ieee80211_beacon_offsets *bo, struct mbuf *m, int mcast)
2165 {
2166 	struct ieee80211com *ic = ni->ni_ic;
2167 	int len_changed = 0;
2168 	uint16_t capinfo;
2169 
2170 	IEEE80211_BEACON_LOCK(ic);
2171 	/* XXX faster to recalculate entirely or just changes? */
2172 	capinfo = getcapinfo(ic, ni->ni_chan);
2173 	*bo->bo_caps = htole16(capinfo);
2174 
2175 	if (ic->ic_flags & IEEE80211_F_WME) {
2176 		struct ieee80211_wme_state *wme = &ic->ic_wme;
2177 
2178 		/*
2179 		 * Check for agressive mode change.  When there is
2180 		 * significant high priority traffic in the BSS
2181 		 * throttle back BE traffic by using conservative
2182 		 * parameters.  Otherwise BE uses agressive params
2183 		 * to optimize performance of legacy/non-QoS traffic.
2184 		 */
2185 		if (wme->wme_flags & WME_F_AGGRMODE) {
2186 			if (wme->wme_hipri_traffic >
2187 			    wme->wme_hipri_switch_thresh) {
2188 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
2189 				    "%s: traffic %u, disable aggressive mode\n",
2190 				    __func__, wme->wme_hipri_traffic);
2191 				wme->wme_flags &= ~WME_F_AGGRMODE;
2192 				ieee80211_wme_updateparams_locked(ic);
2193 				wme->wme_hipri_traffic =
2194 					wme->wme_hipri_switch_hysteresis;
2195 			} else
2196 				wme->wme_hipri_traffic = 0;
2197 		} else {
2198 			if (wme->wme_hipri_traffic <=
2199 			    wme->wme_hipri_switch_thresh) {
2200 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
2201 				    "%s: traffic %u, enable aggressive mode\n",
2202 				    __func__, wme->wme_hipri_traffic);
2203 				wme->wme_flags |= WME_F_AGGRMODE;
2204 				ieee80211_wme_updateparams_locked(ic);
2205 				wme->wme_hipri_traffic = 0;
2206 			} else
2207 				wme->wme_hipri_traffic =
2208 					wme->wme_hipri_switch_hysteresis;
2209 		}
2210 		if (isset(bo->bo_flags, IEEE80211_BEACON_WME)) {
2211 			(void) ieee80211_add_wme_param(bo->bo_wme, wme);
2212 			clrbit(bo->bo_flags, IEEE80211_BEACON_WME);
2213 		}
2214 	}
2215 
2216 	if (isset(bo->bo_flags, IEEE80211_BEACON_HTINFO)) {
2217 		ieee80211_ht_update_beacon(ic, bo);
2218 		clrbit(bo->bo_flags, IEEE80211_BEACON_HTINFO);
2219 	}
2220 
2221 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {	/* NB: no IBSS support*/
2222 		struct ieee80211_tim_ie *tie =
2223 			(struct ieee80211_tim_ie *) bo->bo_tim;
2224 		if (isset(bo->bo_flags, IEEE80211_BEACON_TIM)) {
2225 			u_int timlen, timoff, i;
2226 			/*
2227 			 * ATIM/DTIM needs updating.  If it fits in the
2228 			 * current space allocated then just copy in the
2229 			 * new bits.  Otherwise we need to move any trailing
2230 			 * data to make room.  Note that we know there is
2231 			 * contiguous space because ieee80211_beacon_allocate
2232 			 * insures there is space in the mbuf to write a
2233 			 * maximal-size virtual bitmap (based on ic_max_aid).
2234 			 */
2235 			/*
2236 			 * Calculate the bitmap size and offset, copy any
2237 			 * trailer out of the way, and then copy in the
2238 			 * new bitmap and update the information element.
2239 			 * Note that the tim bitmap must contain at least
2240 			 * one byte and any offset must be even.
2241 			 */
2242 			if (ic->ic_ps_pending != 0) {
2243 				timoff = 128;		/* impossibly large */
2244 				for (i = 0; i < ic->ic_tim_len; i++)
2245 					if (ic->ic_tim_bitmap[i]) {
2246 						timoff = i &~ 1;
2247 						break;
2248 					}
2249 				KASSERT(timoff != 128, ("tim bitmap empty!"));
2250 				for (i = ic->ic_tim_len-1; i >= timoff; i--)
2251 					if (ic->ic_tim_bitmap[i])
2252 						break;
2253 				timlen = 1 + (i - timoff);
2254 			} else {
2255 				timoff = 0;
2256 				timlen = 1;
2257 			}
2258 			if (timlen != bo->bo_tim_len) {
2259 				/* copy up/down trailer */
2260 				int adjust = tie->tim_bitmap+timlen
2261 					   - bo->bo_tim_trailer;
2262 				ovbcopy(bo->bo_tim_trailer,
2263 				    bo->bo_tim_trailer+adjust,
2264 				    bo->bo_tim_trailer_len);
2265 				bo->bo_tim_trailer += adjust;
2266 				bo->bo_wme += adjust;
2267 				bo->bo_erp += adjust;
2268 				bo->bo_htinfo += adjust;
2269 				bo->bo_tim_len = timlen;
2270 
2271 				/* update information element */
2272 				tie->tim_len = 3 + timlen;
2273 				tie->tim_bitctl = timoff;
2274 				len_changed = 1;
2275 			}
2276 			memcpy(tie->tim_bitmap, ic->ic_tim_bitmap + timoff,
2277 				bo->bo_tim_len);
2278 
2279 			clrbit(bo->bo_flags, IEEE80211_BEACON_TIM);
2280 
2281 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
2282 				"%s: TIM updated, pending %u, off %u, len %u\n",
2283 				__func__, ic->ic_ps_pending, timoff, timlen);
2284 		}
2285 		/* count down DTIM period */
2286 		if (tie->tim_count == 0)
2287 			tie->tim_count = tie->tim_period - 1;
2288 		else
2289 			tie->tim_count--;
2290 		/* update state for buffered multicast frames on DTIM */
2291 		if (mcast && tie->tim_count == 0)
2292 			tie->tim_bitctl |= 1;
2293 		else
2294 			tie->tim_bitctl &= ~1;
2295 		if (isset(bo->bo_flags, IEEE80211_BEACON_ERP)) {
2296 			/*
2297 			 * ERP element needs updating.
2298 			 */
2299 			(void) ieee80211_add_erp(bo->bo_erp, ic);
2300 			clrbit(bo->bo_flags, IEEE80211_BEACON_ERP);
2301 		}
2302 	}
2303 	IEEE80211_BEACON_UNLOCK(ic);
2304 
2305 	return len_changed;
2306 }
2307