xref: /netbsd-src/sys/net80211/ieee80211_output.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: ieee80211_output.c,v 1.49 2010/01/19 22:08:17 pooka Exp $	*/
2 /*-
3  * Copyright (c) 2001 Atsushi Onoe
4  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * Alternatively, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2 as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #ifdef __FreeBSD__
36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_output.c,v 1.34 2005/08/10 16:22:29 sam Exp $");
37 #endif
38 #ifdef __NetBSD__
39 __KERNEL_RCSID(0, "$NetBSD: ieee80211_output.c,v 1.49 2010/01/19 22:08:17 pooka Exp $");
40 #endif
41 
42 #include "opt_inet.h"
43 
44 #ifdef __NetBSD__
45 #endif /* __NetBSD__ */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/kernel.h>
51 #include <sys/endian.h>
52 #include <sys/errno.h>
53 #include <sys/proc.h>
54 #include <sys/sysctl.h>
55 
56 #include <net/if.h>
57 #include <net/if_llc.h>
58 #include <net/if_media.h>
59 #include <net/if_arp.h>
60 #include <net/if_ether.h>
61 #include <net/if_llc.h>
62 #include <net/if_vlanvar.h>
63 
64 #include <net80211/ieee80211_netbsd.h>
65 #include <net80211/ieee80211_var.h>
66 
67 #include <net/bpf.h>
68 
69 #ifdef INET
70 #include <netinet/in.h>
71 #include <netinet/in_systm.h>
72 #include <netinet/in_var.h>
73 #include <netinet/ip.h>
74 #include <net/if_ether.h>
75 #endif
76 
77 static int ieee80211_fragment(struct ieee80211com *, struct mbuf *,
78 	u_int hdrsize, u_int ciphdrsize, u_int mtu);
79 
80 #ifdef IEEE80211_DEBUG
81 /*
82  * Decide if an outbound management frame should be
83  * printed when debugging is enabled.  This filters some
84  * of the less interesting frames that come frequently
85  * (e.g. beacons).
86  */
87 static __inline int
88 doprint(struct ieee80211com *ic, int subtype)
89 {
90 	switch (subtype) {
91 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
92 		return (ic->ic_opmode == IEEE80211_M_IBSS);
93 	}
94 	return 1;
95 }
96 #endif
97 
98 /*
99  * Set the direction field and address fields of an outgoing
100  * non-QoS frame.  Note this should be called early on in
101  * constructing a frame as it sets i_fc[1]; other bits can
102  * then be or'd in.
103  */
104 static void
105 ieee80211_send_setup(struct ieee80211com *ic,
106 	struct ieee80211_node *ni,
107 	struct ieee80211_frame *wh,
108 	int type,
109 	const u_int8_t sa[IEEE80211_ADDR_LEN],
110 	const u_int8_t da[IEEE80211_ADDR_LEN],
111 	const u_int8_t bssid[IEEE80211_ADDR_LEN])
112 {
113 #define	WH4(wh)	((struct ieee80211_frame_addr4 *)wh)
114 
115 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | type;
116 	if ((type & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_DATA) {
117 		switch (ic->ic_opmode) {
118 		case IEEE80211_M_STA:
119 			wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
120 			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
121 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
122 			IEEE80211_ADDR_COPY(wh->i_addr3, da);
123 			break;
124 		case IEEE80211_M_IBSS:
125 		case IEEE80211_M_AHDEMO:
126 			wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
127 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
128 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
129 			IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
130 			break;
131 		case IEEE80211_M_HOSTAP:
132 			wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
133 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
134 			IEEE80211_ADDR_COPY(wh->i_addr2, bssid);
135 			IEEE80211_ADDR_COPY(wh->i_addr3, sa);
136 			break;
137 		case IEEE80211_M_MONITOR:	/* NB: to quiet compiler */
138 			break;
139 		}
140 	} else {
141 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
142 		IEEE80211_ADDR_COPY(wh->i_addr1, da);
143 		IEEE80211_ADDR_COPY(wh->i_addr2, sa);
144 		IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
145 	}
146 	*(u_int16_t *)&wh->i_dur[0] = 0;
147 	/* NB: use non-QoS tid */
148 	*(u_int16_t *)&wh->i_seq[0] =
149 	    htole16(ni->ni_txseqs[0] << IEEE80211_SEQ_SEQ_SHIFT);
150 	ni->ni_txseqs[0]++;
151 #undef WH4
152 }
153 
154 /*
155  * Send a management frame to the specified node.  The node pointer
156  * must have a reference as the pointer will be passed to the driver
157  * and potentially held for a long time.  If the frame is successfully
158  * dispatched to the driver, then it is responsible for freeing the
159  * reference (and potentially free'ing up any associated storage).
160  */
161 static int
162 ieee80211_mgmt_output(struct ieee80211com *ic, struct ieee80211_node *ni,
163     struct mbuf *m, int type, int timer)
164 {
165 	struct ifnet *ifp = ic->ic_ifp;
166 	struct ieee80211_frame *wh;
167 
168 	IASSERT(ni != NULL, ("null node"));
169 
170 	/*
171 	 * Yech, hack alert!  We want to pass the node down to the
172 	 * driver's start routine.  If we don't do so then the start
173 	 * routine must immediately look it up again and that can
174 	 * cause a lock order reversal if, for example, this frame
175 	 * is being sent because the station is being timedout and
176 	 * the frame being sent is a DEAUTH message.  We could stick
177 	 * this in an m_tag and tack that on to the mbuf.  However
178 	 * that's rather expensive to do for every frame so instead
179 	 * we stuff it in the rcvif field since outbound frames do
180 	 * not (presently) use this.
181 	 */
182 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
183 	if (m == NULL)
184 		return ENOMEM;
185 #ifdef __FreeBSD__
186 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
187 #endif
188 	m->m_pkthdr.rcvif = (void *)ni;
189 
190 	wh = mtod(m, struct ieee80211_frame *);
191 	ieee80211_send_setup(ic, ni, wh,
192 		IEEE80211_FC0_TYPE_MGT | type,
193 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
194 	if ((m->m_flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
195 		m->m_flags &= ~M_LINK0;
196 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
197 			"[%s] encrypting frame (%s)\n",
198 			ether_sprintf(wh->i_addr1), __func__);
199 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
200 	}
201 #ifdef IEEE80211_DEBUG
202 	/* avoid printing too many frames */
203 	if ((ieee80211_msg_debug(ic) && doprint(ic, type)) ||
204 	    ieee80211_msg_dumppkts(ic)) {
205 		printf("[%s] send %s on channel %u\n",
206 		    ether_sprintf(wh->i_addr1),
207 		    ieee80211_mgt_subtype_name[
208 			(type & IEEE80211_FC0_SUBTYPE_MASK) >>
209 				IEEE80211_FC0_SUBTYPE_SHIFT],
210 		    ieee80211_chan2ieee(ic, ic->ic_curchan));
211 	}
212 #endif
213 	IEEE80211_NODE_STAT(ni, tx_mgmt);
214 	IF_ENQUEUE(&ic->ic_mgtq, m);
215 	if (timer) {
216 		/*
217 		 * Set the mgt frame timeout.
218 		 */
219 		ic->ic_mgt_timer = timer;
220 		ifp->if_timer = 1;
221 	}
222 	(*ifp->if_start)(ifp);
223 	return 0;
224 }
225 
226 /*
227  * Send a null data frame to the specified node.
228  *
229  * NB: the caller is assumed to have setup a node reference
230  *     for use; this is necessary to deal with a race condition
231  *     when probing for inactive stations.
232  */
233 int
234 ieee80211_send_nulldata(struct ieee80211_node *ni)
235 {
236 	struct ieee80211com *ic = ni->ni_ic;
237 	struct ifnet *ifp = ic->ic_ifp;
238 	struct mbuf *m;
239 	struct ieee80211_frame *wh;
240 
241 	MGETHDR(m, M_NOWAIT, MT_HEADER);
242 	if (m == NULL) {
243 		/* XXX debug msg */
244 		ic->ic_stats.is_tx_nobuf++;
245 		ieee80211_unref_node(&ni);
246 		return ENOMEM;
247 	}
248 	m->m_pkthdr.rcvif = (void *) ni;
249 
250 	wh = mtod(m, struct ieee80211_frame *);
251 	ieee80211_send_setup(ic, ni, wh,
252 		IEEE80211_FC0_TYPE_DATA | IEEE80211_FC0_SUBTYPE_NODATA,
253 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
254 	/* NB: power management bit is never sent by an AP */
255 	if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) &&
256 	    ic->ic_opmode != IEEE80211_M_HOSTAP)
257 		wh->i_fc[1] |= IEEE80211_FC1_PWR_MGT;
258 	m->m_len = m->m_pkthdr.len = sizeof(struct ieee80211_frame);
259 
260 	IEEE80211_NODE_STAT(ni, tx_data);
261 
262 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
263 	    "[%s] send null data frame on channel %u, pwr mgt %s\n",
264 	    ether_sprintf(ni->ni_macaddr),
265 	    ieee80211_chan2ieee(ic, ic->ic_curchan),
266 	    wh->i_fc[1] & IEEE80211_FC1_PWR_MGT ? "ena" : "dis");
267 
268 	IF_ENQUEUE(&ic->ic_mgtq, m);		/* cheat */
269 	(*ifp->if_start)(ifp);
270 
271 	return 0;
272 }
273 
274 /*
275  * Assign priority to a frame based on any vlan tag assigned
276  * to the station and/or any Diffserv setting in an IP header.
277  * Finally, if an ACM policy is setup (in station mode) it's
278  * applied.
279  */
280 int
281 ieee80211_classify(struct ieee80211com *ic, struct mbuf *m, struct ieee80211_node *ni)
282 {
283 	int v_wme_ac, d_wme_ac, ac;
284 #ifdef INET
285 	struct ether_header *eh;
286 #endif
287 
288 	if ((ni->ni_flags & IEEE80211_NODE_QOS) == 0) {
289 		ac = WME_AC_BE;
290 		goto done;
291 	}
292 
293 	/*
294 	 * If node has a vlan tag then all traffic
295 	 * to it must have a matching tag.
296 	 */
297 	v_wme_ac = 0;
298 	if (ni->ni_vlan != 0) {
299 		/* XXX used to check ec_nvlans. */
300 		struct m_tag *mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL);
301 		if (mtag == NULL) {
302 			IEEE80211_NODE_STAT(ni, tx_novlantag);
303 			return 1;
304 		}
305 		if (EVL_VLANOFTAG(VLAN_TAG_VALUE(mtag)) !=
306 		    EVL_VLANOFTAG(ni->ni_vlan)) {
307 			IEEE80211_NODE_STAT(ni, tx_vlanmismatch);
308 			return 1;
309 		}
310 		/* map vlan priority to AC */
311 		switch (EVL_PRIOFTAG(ni->ni_vlan)) {
312 		case 1:
313 		case 2:
314 			v_wme_ac = WME_AC_BK;
315 			break;
316 		case 0:
317 		case 3:
318 			v_wme_ac = WME_AC_BE;
319 			break;
320 		case 4:
321 		case 5:
322 			v_wme_ac = WME_AC_VI;
323 			break;
324 		case 6:
325 		case 7:
326 			v_wme_ac = WME_AC_VO;
327 			break;
328 		}
329 	}
330 
331 #ifdef INET
332 	eh = mtod(m, struct ether_header *);
333 	if (eh->ether_type == htons(ETHERTYPE_IP)) {
334 		const struct ip *ip = (struct ip *)
335 			(mtod(m, u_int8_t *) + sizeof (*eh));
336 		/*
337 		 * IP frame, map the TOS field.
338 		 */
339 		switch (ip->ip_tos) {
340 		case 0x08:
341 		case 0x20:
342 			d_wme_ac = WME_AC_BK;	/* background */
343 			break;
344 		case 0x28:
345 		case 0xa0:
346 			d_wme_ac = WME_AC_VI;	/* video */
347 			break;
348 		case 0x30:			/* voice */
349 		case 0xe0:
350 		case 0x88:			/* XXX UPSD */
351 		case 0xb8:
352 			d_wme_ac = WME_AC_VO;
353 			break;
354 		default:
355 			d_wme_ac = WME_AC_BE;
356 			break;
357 		}
358 	} else {
359 #endif /* INET */
360 		d_wme_ac = WME_AC_BE;
361 #ifdef INET
362 	}
363 #endif
364 	/*
365 	 * Use highest priority AC.
366 	 */
367 	if (v_wme_ac > d_wme_ac)
368 		ac = v_wme_ac;
369 	else
370 		ac = d_wme_ac;
371 
372 	/*
373 	 * Apply ACM policy.
374 	 */
375 	if (ic->ic_opmode == IEEE80211_M_STA) {
376 		static const int acmap[4] = {
377 			WME_AC_BK,	/* WME_AC_BE */
378 			WME_AC_BK,	/* WME_AC_BK */
379 			WME_AC_BE,	/* WME_AC_VI */
380 			WME_AC_VI,	/* WME_AC_VO */
381 		};
382 		while (ac != WME_AC_BK &&
383 		    ic->ic_wme.wme_wmeBssChanParams.cap_wmeParams[ac].wmep_acm)
384 			ac = acmap[ac];
385 	}
386 done:
387 	M_WME_SETAC(m, ac);
388 	return 0;
389 }
390 
391 /*
392  * Insure there is sufficient contiguous space to encapsulate the
393  * 802.11 data frame.  If room isn't already there, arrange for it.
394  * Drivers and cipher modules assume we have done the necessary work
395  * and fail rudely if they don't find the space they need.
396  */
397 static struct mbuf *
398 ieee80211_mbuf_adjust(struct ieee80211com *ic, int hdrsize,
399 	struct ieee80211_key *key, struct mbuf *m)
400 {
401 #define	TO_BE_RECLAIMED	(sizeof(struct ether_header) - sizeof(struct llc))
402 	int needed_space = hdrsize;
403 	int wlen = 0;
404 
405 	if (key != NULL) {
406 		/* XXX belongs in crypto code? */
407 		needed_space += key->wk_cipher->ic_header;
408 		/* XXX frags */
409 	}
410 	/*
411 	 * We know we are called just before stripping an Ethernet
412 	 * header and prepending an LLC header.  This means we know
413 	 * there will be
414 	 *	sizeof(struct ether_header) - sizeof(struct llc)
415 	 * bytes recovered to which we need additional space for the
416 	 * 802.11 header and any crypto header.
417 	 */
418 	/* XXX check trailing space and copy instead? */
419 	if (M_LEADINGSPACE(m) < needed_space - TO_BE_RECLAIMED) {
420 		struct mbuf *n = m_gethdr(M_NOWAIT, m->m_type);
421 		if (n == NULL) {
422 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
423 			    "%s: cannot expand storage\n", __func__);
424 			ic->ic_stats.is_tx_nobuf++;
425 			m_freem(m);
426 			return NULL;
427 		}
428 		IASSERT(needed_space <= MHLEN,
429 		    ("not enough room, need %u got %zu\n", needed_space, MHLEN));
430 		/*
431 		 * Setup new mbuf to have leading space to prepend the
432 		 * 802.11 header and any crypto header bits that are
433 		 * required (the latter are added when the driver calls
434 		 * back to ieee80211_crypto_encap to do crypto encapsulation).
435 		 */
436 		/* NB: must be first 'cuz it clobbers m_data */
437 		M_MOVE_PKTHDR(n, m);
438 		n->m_len = 0;			/* NB: m_gethdr does not set */
439 		n->m_data += needed_space;
440 		/*
441 		 * Pull up Ethernet header to create the expected layout.
442 		 * We could use m_pullup but that's overkill (i.e. we don't
443 		 * need the actual data) and it cannot fail so do it inline
444 		 * for speed.
445 		 */
446 		/* NB: struct ether_header is known to be contiguous */
447 		n->m_len += sizeof(struct ether_header);
448 		m->m_len -= sizeof(struct ether_header);
449 		m->m_data += sizeof(struct ether_header);
450 		/*
451 		 * Replace the head of the chain.
452 		 */
453 		n->m_next = m;
454 		m = n;
455 	} else {
456                 /* We will overwrite the ethernet header in the
457                  * 802.11 encapsulation stage.  Make sure that it
458                  * is writable.
459 		 */
460 		wlen = sizeof(struct ether_header);
461 	}
462 
463 	/*
464 	 * If we're going to s/w encrypt the mbuf chain make sure it is
465 	 * writable.
466 	 */
467 	if (key != NULL && (key->wk_flags & IEEE80211_KEY_SWCRYPT) != 0)
468 		wlen = M_COPYALL;
469 
470 	if (wlen != 0 && m_makewritable(&m, 0, wlen, M_DONTWAIT) != 0) {
471 		m_freem(m);
472 		return NULL;
473 	}
474 	return m;
475 #undef TO_BE_RECLAIMED
476 }
477 
478 /*
479  * Return the transmit key to use in sending a unicast frame.
480  * If a unicast key is set we use that.  When no unicast key is set
481  * we fall back to the default transmit key.
482  */
483 static __inline struct ieee80211_key *
484 ieee80211_crypto_getucastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
485 {
486 	if (IEEE80211_KEY_UNDEFINED(ni->ni_ucastkey)) {
487 		if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
488 		    IEEE80211_KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
489 			return NULL;
490 		return &ic->ic_nw_keys[ic->ic_def_txkey];
491 	} else {
492 		return &ni->ni_ucastkey;
493 	}
494 }
495 
496 /*
497  * Return the transmit key to use in sending a multicast frame.
498  * Multicast traffic always uses the group key which is installed as
499  * the default tx key.
500  */
501 static __inline struct ieee80211_key *
502 ieee80211_crypto_getmcastkey(struct ieee80211com *ic,
503     struct ieee80211_node *ni)
504 {
505 	if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
506 	    IEEE80211_KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
507 		return NULL;
508 	return &ic->ic_nw_keys[ic->ic_def_txkey];
509 }
510 
511 /*
512  * Encapsulate an outbound data frame.  The mbuf chain is updated.
513  * If an error is encountered NULL is returned.  The caller is required
514  * to provide a node reference and pullup the ethernet header in the
515  * first mbuf.
516  */
517 struct mbuf *
518 ieee80211_encap(struct ieee80211com *ic, struct mbuf *m,
519 	struct ieee80211_node *ni)
520 {
521 	struct ether_header eh;
522 	struct ieee80211_frame *wh;
523 	struct ieee80211_key *key;
524 	struct llc *llc;
525 	int hdrsize, datalen, addqos, txfrag;
526 
527 	IASSERT(m->m_len >= sizeof(eh), ("no ethernet header!"));
528 	memcpy(&eh, mtod(m, void *), sizeof(struct ether_header));
529 
530 	/*
531 	 * Insure space for additional headers.  First identify
532 	 * transmit key to use in calculating any buffer adjustments
533 	 * required.  This is also used below to do privacy
534 	 * encapsulation work.  Then calculate the 802.11 header
535 	 * size and any padding required by the driver.
536 	 *
537 	 * Note key may be NULL if we fall back to the default
538 	 * transmit key and that is not set.  In that case the
539 	 * buffer may not be expanded as needed by the cipher
540 	 * routines, but they will/should discard it.
541 	 */
542 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
543 		if (ic->ic_opmode == IEEE80211_M_STA ||
544 		    !IEEE80211_IS_MULTICAST(eh.ether_dhost))
545 			key = ieee80211_crypto_getucastkey(ic, ni);
546 		else
547 			key = ieee80211_crypto_getmcastkey(ic, ni);
548 		if (key == NULL && eh.ether_type != htons(ETHERTYPE_PAE)) {
549 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
550 			    "[%s] no default transmit key (%s) deftxkey %u\n",
551 			    ether_sprintf(eh.ether_dhost), __func__,
552 			    ic->ic_def_txkey);
553 			ic->ic_stats.is_tx_nodefkey++;
554 		}
555 	} else
556 		key = NULL;
557 	/* XXX 4-address format */
558 	/*
559 	 * XXX Some ap's don't handle QoS-encapsulated EAPOL
560 	 * frames so suppress use.  This may be an issue if other
561 	 * ap's require all data frames to be QoS-encapsulated
562 	 * once negotiated in which case we'll need to make this
563 	 * configurable.
564 	 */
565 	addqos = (ni->ni_flags & IEEE80211_NODE_QOS) &&
566 		 eh.ether_type != htons(ETHERTYPE_PAE);
567 	if (addqos)
568 		hdrsize = sizeof(struct ieee80211_qosframe);
569 	else
570 		hdrsize = sizeof(struct ieee80211_frame);
571 	if (ic->ic_flags & IEEE80211_F_DATAPAD)
572 		hdrsize = roundup(hdrsize, sizeof(u_int32_t));
573 	m = ieee80211_mbuf_adjust(ic, hdrsize, key, m);
574 	if (m == NULL) {
575 		/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
576 		goto bad;
577 	}
578 
579 	/* NB: this could be optimized because of ieee80211_mbuf_adjust */
580 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
581 	llc = mtod(m, struct llc *);
582 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
583 	llc->llc_control = LLC_UI;
584 	llc->llc_snap.org_code[0] = 0;
585 	llc->llc_snap.org_code[1] = 0;
586 	llc->llc_snap.org_code[2] = 0;
587 	llc->llc_snap.ether_type = eh.ether_type;
588 	datalen = m->m_pkthdr.len;		/* NB: w/o 802.11 header */
589 
590 	M_PREPEND(m, hdrsize, M_DONTWAIT);
591 	if (m == NULL) {
592 		ic->ic_stats.is_tx_nobuf++;
593 		goto bad;
594 	}
595 	wh = mtod(m, struct ieee80211_frame *);
596 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
597 	*(u_int16_t *)wh->i_dur = 0;
598 	switch (ic->ic_opmode) {
599 	case IEEE80211_M_STA:
600 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
601 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
602 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
603 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
604 		break;
605 	case IEEE80211_M_IBSS:
606 	case IEEE80211_M_AHDEMO:
607 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
608 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
609 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
610 		/*
611 		 * NB: always use the bssid from ic_bss as the
612 		 *     neighbor's may be stale after an ibss merge
613 		 */
614 		IEEE80211_ADDR_COPY(wh->i_addr3, ic->ic_bss->ni_bssid);
615 		break;
616 	case IEEE80211_M_HOSTAP:
617 #ifndef IEEE80211_NO_HOSTAP
618 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
619 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
620 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
621 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
622 #endif /* !IEEE80211_NO_HOSTAP */
623 		break;
624 	case IEEE80211_M_MONITOR:
625 		goto bad;
626 	}
627 	if (m->m_flags & M_MORE_DATA)
628 		wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
629 	if (addqos) {
630 		struct ieee80211_qosframe *qwh =
631 			(struct ieee80211_qosframe *) wh;
632 		int ac, tid;
633 
634 		ac = M_WME_GETAC(m);
635 		/* map from access class/queue to 11e header priorty value */
636 		tid = WME_AC_TO_TID(ac);
637 		qwh->i_qos[0] = tid & IEEE80211_QOS_TID;
638 		if (ic->ic_wme.wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy)
639 			qwh->i_qos[0] |= 1 << IEEE80211_QOS_ACKPOLICY_S;
640 		qwh->i_qos[1] = 0;
641 		qwh->i_fc[0] |= IEEE80211_FC0_SUBTYPE_QOS;
642 
643 		*(u_int16_t *)wh->i_seq =
644 		    htole16(ni->ni_txseqs[tid] << IEEE80211_SEQ_SEQ_SHIFT);
645 		ni->ni_txseqs[tid]++;
646 	} else {
647 		*(u_int16_t *)wh->i_seq =
648 		    htole16(ni->ni_txseqs[0] << IEEE80211_SEQ_SEQ_SHIFT);
649 		ni->ni_txseqs[0]++;
650 	}
651 	/* check if xmit fragmentation is required */
652 	txfrag = (m->m_pkthdr.len > ic->ic_fragthreshold &&
653 	    !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
654 	    (m->m_flags & M_FF) == 0);          /* NB: don't fragment ff's */
655 	if (key != NULL) {
656 		/*
657 		 * IEEE 802.1X: send EAPOL frames always in the clear.
658 		 * WPA/WPA2: encrypt EAPOL keys when pairwise keys are set.
659 		 */
660 		if (eh.ether_type != htons(ETHERTYPE_PAE) ||
661 		    ((ic->ic_flags & IEEE80211_F_WPA) &&
662 		     (ic->ic_opmode == IEEE80211_M_STA ?
663 		      !IEEE80211_KEY_UNDEFINED(*key) :
664 		      !IEEE80211_KEY_UNDEFINED(ni->ni_ucastkey)))) {
665 			wh->i_fc[1] |= IEEE80211_FC1_WEP;
666 			if (!ieee80211_crypto_enmic(ic, key, m, txfrag)) {
667 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
668 				    "[%s] enmic failed, discard frame\n",
669 				    ether_sprintf(eh.ether_dhost));
670 				ic->ic_stats.is_crypto_enmicfail++;
671 				goto bad;
672 			}
673 		}
674 	}
675 	if (txfrag && !ieee80211_fragment(ic, m, hdrsize,
676 	    key != NULL ? key->wk_cipher->ic_header : 0, ic->ic_fragthreshold))
677 		goto bad;
678 
679 	IEEE80211_NODE_STAT(ni, tx_data);
680 	IEEE80211_NODE_STAT_ADD(ni, tx_bytes, datalen);
681 
682 	return m;
683 bad:
684 	if (m != NULL)
685 		m_freem(m);
686 	return NULL;
687 }
688 
689 /*
690  * Arguments in:
691  *
692  * paylen:  payload length (no FCS, no WEP header)
693  *
694  * hdrlen:  header length
695  *
696  * rate:    MSDU speed, units 500kb/s
697  *
698  * flags:   IEEE80211_F_SHPREAMBLE (use short preamble),
699  *          IEEE80211_F_SHSLOT (use short slot length)
700  *
701  * Arguments out:
702  *
703  * d:       802.11 Duration field for RTS,
704  *          802.11 Duration field for data frame,
705  *          PLCP Length for data frame,
706  *          residual octets at end of data slot
707  */
708 static int
709 ieee80211_compute_duration1(int len, int use_ack, uint32_t icflags, int rate,
710     struct ieee80211_duration *d)
711 {
712 	int pre, ctsrate;
713 	int ack, bitlen, data_dur, remainder;
714 
715 	/* RTS reserves medium for SIFS | CTS | SIFS | (DATA) | SIFS | ACK
716 	 * DATA reserves medium for SIFS | ACK,
717 	 *
718 	 * (XXX or SIFS | ACK | SIFS | DATA | SIFS | ACK, if more fragments)
719 	 *
720 	 * XXXMYC: no ACK on multicast/broadcast or control packets
721 	 */
722 
723 	bitlen = len * 8;
724 
725 	pre = IEEE80211_DUR_DS_SIFS;
726 	if ((icflags & IEEE80211_F_SHPREAMBLE) != 0)
727 		pre += IEEE80211_DUR_DS_SHORT_PREAMBLE + IEEE80211_DUR_DS_FAST_PLCPHDR;
728 	else
729 		pre += IEEE80211_DUR_DS_LONG_PREAMBLE + IEEE80211_DUR_DS_SLOW_PLCPHDR;
730 
731 	d->d_residue = 0;
732 	data_dur = (bitlen * 2) / rate;
733 	remainder = (bitlen * 2) % rate;
734 	if (remainder != 0) {
735 		d->d_residue = (rate - remainder) / 16;
736 		data_dur++;
737 	}
738 
739 	switch (rate) {
740 	case 2:		/* 1 Mb/s */
741 	case 4:		/* 2 Mb/s */
742 		/* 1 - 2 Mb/s WLAN: send ACK/CTS at 1 Mb/s */
743 		ctsrate = 2;
744 		break;
745 	case 11:	/* 5.5 Mb/s */
746 	case 22:	/* 11  Mb/s */
747 	case 44:	/* 22  Mb/s */
748 		/* 5.5 - 11 Mb/s WLAN: send ACK/CTS at 2 Mb/s */
749 		ctsrate = 4;
750 		break;
751 	default:
752 		/* TBD */
753 		return -1;
754 	}
755 
756 	d->d_plcp_len = data_dur;
757 
758 	ack = (use_ack) ? pre + (IEEE80211_DUR_DS_SLOW_ACK * 2) / ctsrate : 0;
759 
760 	d->d_rts_dur =
761 	    pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate +
762 	    pre + data_dur +
763 	    ack;
764 
765 	d->d_data_dur = ack;
766 
767 	return 0;
768 }
769 
770 /*
771  * Arguments in:
772  *
773  * wh:      802.11 header
774  *
775  * paylen:  payload length (no FCS, no WEP header)
776  *
777  * rate:    MSDU speed, units 500kb/s
778  *
779  * fraglen: fragment length, set to maximum (or higher) for no
780  *          fragmentation
781  *
782  * flags:   IEEE80211_F_PRIVACY (hardware adds WEP),
783  *          IEEE80211_F_SHPREAMBLE (use short preamble),
784  *          IEEE80211_F_SHSLOT (use short slot length)
785  *
786  * Arguments out:
787  *
788  * d0: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
789  *     of first/only fragment
790  *
791  * dn: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
792  *     of last fragment
793  *
794  * ieee80211_compute_duration assumes crypto-encapsulation, if any,
795  * has already taken place.
796  */
797 int
798 ieee80211_compute_duration(const struct ieee80211_frame_min *wh,
799     const struct ieee80211_key *wk, int len,
800     uint32_t icflags, int fraglen, int rate, struct ieee80211_duration *d0,
801     struct ieee80211_duration *dn, int *npktp, int debug)
802 {
803 	int ack, rc;
804 	int cryptolen,	/* crypto overhead: header+trailer */
805 	    firstlen,	/* first fragment's payload + overhead length */
806 	    hdrlen,	/* header length w/o driver padding */
807 	    lastlen,	/* last fragment's payload length w/ overhead */
808 	    lastlen0,	/* last fragment's payload length w/o overhead */
809 	    npkt,	/* number of fragments */
810 	    overlen,	/* non-802.11 header overhead per fragment */
811 	    paylen;	/* payload length w/o overhead */
812 
813 	hdrlen = ieee80211_anyhdrsize((const void *)wh);
814 
815         /* Account for padding required by the driver. */
816 	if (icflags & IEEE80211_F_DATAPAD)
817 		paylen = len - roundup(hdrlen, sizeof(u_int32_t));
818 	else
819 		paylen = len - hdrlen;
820 
821 	overlen = IEEE80211_CRC_LEN;
822 
823 	if (wk != NULL) {
824 		cryptolen = wk->wk_cipher->ic_header +
825 		            wk->wk_cipher->ic_trailer;
826 		paylen -= cryptolen;
827 		overlen += cryptolen;
828 	}
829 
830 	npkt = paylen / fraglen;
831 	lastlen0 = paylen % fraglen;
832 
833 	if (npkt == 0)			/* no fragments */
834 		lastlen = paylen + overlen;
835 	else if (lastlen0 != 0) {	/* a short "tail" fragment */
836 		lastlen = lastlen0 + overlen;
837 		npkt++;
838 	} else				/* full-length "tail" fragment */
839 		lastlen = fraglen + overlen;
840 
841 	if (npktp != NULL)
842 		*npktp = npkt;
843 
844 	if (npkt > 1)
845 		firstlen = fraglen + overlen;
846 	else
847 		firstlen = paylen + overlen;
848 
849 	if (debug) {
850 		printf("%s: npkt %d firstlen %d lastlen0 %d lastlen %d "
851 		    "fraglen %d overlen %d len %d rate %d icflags %08x\n",
852 		    __func__, npkt, firstlen, lastlen0, lastlen, fraglen,
853 		    overlen, len, rate, icflags);
854 	}
855 
856 	ack = !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
857 	    (wh->i_fc[1] & IEEE80211_FC0_TYPE_MASK) != IEEE80211_FC0_TYPE_CTL;
858 
859 	rc = ieee80211_compute_duration1(firstlen + hdrlen,
860 	    ack, icflags, rate, d0);
861 	if (rc == -1)
862 		return rc;
863 
864 	if (npkt <= 1) {
865 		*dn = *d0;
866 		return 0;
867 	}
868 	return ieee80211_compute_duration1(lastlen + hdrlen, ack, icflags, rate,
869 	    dn);
870 }
871 
872 /*
873  * Fragment the frame according to the specified mtu.
874  * The size of the 802.11 header (w/o padding) is provided
875  * so we don't need to recalculate it.  We create a new
876  * mbuf for each fragment and chain it through m_nextpkt;
877  * we might be able to optimize this by reusing the original
878  * packet's mbufs but that is significantly more complicated.
879  */
880 static int
881 ieee80211_fragment(struct ieee80211com *ic, struct mbuf *m0,
882 	u_int hdrsize, u_int ciphdrsize, u_int mtu)
883 {
884 	struct ieee80211_frame *wh, *whf;
885 	struct mbuf *m, *prev, *next;
886 	u_int totalhdrsize, fragno, fragsize, off, remainder, payload;
887 
888 	IASSERT(m0->m_nextpkt == NULL, ("mbuf already chained?"));
889 	IASSERT(m0->m_pkthdr.len > mtu,
890 		("pktlen %u mtu %u", m0->m_pkthdr.len, mtu));
891 
892 	wh = mtod(m0, struct ieee80211_frame *);
893 	/* NB: mark the first frag; it will be propagated below */
894 	wh->i_fc[1] |= IEEE80211_FC1_MORE_FRAG;
895 	totalhdrsize = hdrsize + ciphdrsize;
896 	fragno = 1;
897 	off = mtu - ciphdrsize;
898 	remainder = m0->m_pkthdr.len - off;
899 	prev = m0;
900 	do {
901 		fragsize = totalhdrsize + remainder;
902 		if (fragsize > mtu)
903 			fragsize = mtu;
904 		IASSERT(fragsize < MCLBYTES,
905 			("fragment size %u too big!", fragsize));
906 		if (fragsize > MHLEN)
907 			m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
908 		else
909 			m = m_gethdr(M_DONTWAIT, MT_DATA);
910 		if (m == NULL)
911 			goto bad;
912 		/* leave room to prepend any cipher header */
913 		m_align(m, fragsize - ciphdrsize);
914 
915 		/*
916 		 * Form the header in the fragment.  Note that since
917 		 * we mark the first fragment with the MORE_FRAG bit
918 		 * it automatically is propagated to each fragment; we
919 		 * need only clear it on the last fragment (done below).
920 		 */
921 		whf = mtod(m, struct ieee80211_frame *);
922 		memcpy(whf, wh, hdrsize);
923 		*(u_int16_t *)&whf->i_seq[0] |= htole16(
924 			(fragno & IEEE80211_SEQ_FRAG_MASK) <<
925 				IEEE80211_SEQ_FRAG_SHIFT);
926 		fragno++;
927 
928 		payload = fragsize - totalhdrsize;
929 		/* NB: destination is known to be contiguous */
930 		m_copydata(m0, off, payload, mtod(m, u_int8_t *) + hdrsize);
931 		m->m_len = hdrsize + payload;
932 		m->m_pkthdr.len = hdrsize + payload;
933 		m->m_flags |= M_FRAG;
934 
935 		/* chain up the fragment */
936 		prev->m_nextpkt = m;
937 		prev = m;
938 
939 		/* deduct fragment just formed */
940 		remainder -= payload;
941 		off += payload;
942 	} while (remainder != 0);
943 	whf->i_fc[1] &= ~IEEE80211_FC1_MORE_FRAG;
944 
945 	/* strip first mbuf now that everything has been copied */
946 	m_adj(m0, -(m0->m_pkthdr.len - (mtu - ciphdrsize)));
947 	m0->m_flags |= M_FIRSTFRAG | M_FRAG;
948 
949 	ic->ic_stats.is_tx_fragframes++;
950 	ic->ic_stats.is_tx_frags += fragno-1;
951 
952 	return 1;
953 bad:
954 	/* reclaim fragments but leave original frame for caller to free */
955 	for (m = m0->m_nextpkt; m != NULL; m = next) {
956 		next = m->m_nextpkt;
957 		m->m_nextpkt = NULL;            /* XXX paranoid */
958 		m_freem(m);
959 	}
960 	m0->m_nextpkt = NULL;
961 	return 0;
962 }
963 
964 /*
965  * Add a supported rates element id to a frame.
966  */
967 static u_int8_t *
968 ieee80211_add_rates(u_int8_t *frm, const struct ieee80211_rateset *rs)
969 {
970 	int nrates;
971 
972 	*frm++ = IEEE80211_ELEMID_RATES;
973 	nrates = rs->rs_nrates;
974 	if (nrates > IEEE80211_RATE_SIZE)
975 		nrates = IEEE80211_RATE_SIZE;
976 	*frm++ = nrates;
977 	memcpy(frm, rs->rs_rates, nrates);
978 	return frm + nrates;
979 }
980 
981 /*
982  * Add an extended supported rates element id to a frame.
983  */
984 static u_int8_t *
985 ieee80211_add_xrates(u_int8_t *frm, const struct ieee80211_rateset *rs)
986 {
987 	/*
988 	 * Add an extended supported rates element if operating in 11g mode.
989 	 */
990 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
991 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
992 		*frm++ = IEEE80211_ELEMID_XRATES;
993 		*frm++ = nrates;
994 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
995 		frm += nrates;
996 	}
997 	return frm;
998 }
999 
1000 /*
1001  * Add an ssid elemet to a frame.
1002  */
1003 static u_int8_t *
1004 ieee80211_add_ssid(u_int8_t *frm, const u_int8_t *ssid, u_int len)
1005 {
1006 	*frm++ = IEEE80211_ELEMID_SSID;
1007 	*frm++ = len;
1008 	memcpy(frm, ssid, len);
1009 	return frm + len;
1010 }
1011 
1012 /*
1013  * Add an erp element to a frame.
1014  */
1015 static u_int8_t *
1016 ieee80211_add_erp(u_int8_t *frm, struct ieee80211com *ic)
1017 {
1018 	u_int8_t erp;
1019 
1020 	*frm++ = IEEE80211_ELEMID_ERP;
1021 	*frm++ = 1;
1022 	erp = 0;
1023 	if (ic->ic_nonerpsta != 0)
1024 		erp |= IEEE80211_ERP_NON_ERP_PRESENT;
1025 	if (ic->ic_flags & IEEE80211_F_USEPROT)
1026 		erp |= IEEE80211_ERP_USE_PROTECTION;
1027 	if (ic->ic_flags & IEEE80211_F_USEBARKER)
1028 		erp |= IEEE80211_ERP_LONG_PREAMBLE;
1029 	*frm++ = erp;
1030 	return frm;
1031 }
1032 
1033 static u_int8_t *
1034 ieee80211_setup_wpa_ie(struct ieee80211com *ic, u_int8_t *ie)
1035 {
1036 #define	WPA_OUI_BYTES		0x00, 0x50, 0xf2
1037 #define	ADDSHORT(frm, v) do {			\
1038 	frm[0] = (v) & 0xff;			\
1039 	frm[1] = (v) >> 8;			\
1040 	frm += 2;				\
1041 } while (0)
1042 #define	ADDSELECTOR(frm, sel) do {		\
1043 	memcpy(frm, sel, 4);			\
1044 	frm += 4;				\
1045 } while (0)
1046 	static const u_int8_t oui[4] = { WPA_OUI_BYTES, WPA_OUI_TYPE };
1047 	static const u_int8_t cipher_suite[][4] = {
1048 		{ WPA_OUI_BYTES, WPA_CSE_WEP40 },	/* NB: 40-bit */
1049 		{ WPA_OUI_BYTES, WPA_CSE_TKIP },
1050 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX WRAP */
1051 		{ WPA_OUI_BYTES, WPA_CSE_CCMP },
1052 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1053 		{ WPA_OUI_BYTES, WPA_CSE_NULL },
1054 	};
1055 	static const u_int8_t wep104_suite[4] =
1056 		{ WPA_OUI_BYTES, WPA_CSE_WEP104 };
1057 	static const u_int8_t key_mgt_unspec[4] =
1058 		{ WPA_OUI_BYTES, WPA_ASE_8021X_UNSPEC };
1059 	static const u_int8_t key_mgt_psk[4] =
1060 		{ WPA_OUI_BYTES, WPA_ASE_8021X_PSK };
1061 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1062 	u_int8_t *frm = ie;
1063 	u_int8_t *selcnt;
1064 
1065 	*frm++ = IEEE80211_ELEMID_VENDOR;
1066 	*frm++ = 0;				/* length filled in below */
1067 	memcpy(frm, oui, sizeof(oui));		/* WPA OUI */
1068 	frm += sizeof(oui);
1069 	ADDSHORT(frm, WPA_VERSION);
1070 
1071 	/* XXX filter out CKIP */
1072 
1073 	/* multicast cipher */
1074 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1075 	    rsn->rsn_mcastkeylen >= 13)
1076 		ADDSELECTOR(frm, wep104_suite);
1077 	else
1078 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1079 
1080 	/* unicast cipher list */
1081 	selcnt = frm;
1082 	ADDSHORT(frm, 0);			/* selector count */
1083 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1084 		selcnt[0]++;
1085 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1086 	}
1087 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1088 		selcnt[0]++;
1089 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1090 	}
1091 
1092 	/* authenticator selector list */
1093 	selcnt = frm;
1094 	ADDSHORT(frm, 0);			/* selector count */
1095 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1096 		selcnt[0]++;
1097 		ADDSELECTOR(frm, key_mgt_unspec);
1098 	}
1099 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1100 		selcnt[0]++;
1101 		ADDSELECTOR(frm, key_mgt_psk);
1102 	}
1103 
1104 	/* optional capabilities */
1105 	if (rsn->rsn_caps != 0 && rsn->rsn_caps != RSN_CAP_PREAUTH)
1106 		ADDSHORT(frm, rsn->rsn_caps);
1107 
1108 	/* calculate element length */
1109 	ie[1] = frm - ie - 2;
1110 	IASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1111 		("WPA IE too big, %u > %zu",
1112 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1113 	return frm;
1114 #undef ADDSHORT
1115 #undef ADDSELECTOR
1116 #undef WPA_OUI_BYTES
1117 }
1118 
1119 static u_int8_t *
1120 ieee80211_setup_rsn_ie(struct ieee80211com *ic, u_int8_t *ie)
1121 {
1122 #define	RSN_OUI_BYTES		0x00, 0x0f, 0xac
1123 #define	ADDSHORT(frm, v) do {			\
1124 	frm[0] = (v) & 0xff;			\
1125 	frm[1] = (v) >> 8;			\
1126 	frm += 2;				\
1127 } while (0)
1128 #define	ADDSELECTOR(frm, sel) do {		\
1129 	memcpy(frm, sel, 4);			\
1130 	frm += 4;				\
1131 } while (0)
1132 	static const u_int8_t cipher_suite[][4] = {
1133 		{ RSN_OUI_BYTES, RSN_CSE_WEP40 },	/* NB: 40-bit */
1134 		{ RSN_OUI_BYTES, RSN_CSE_TKIP },
1135 		{ RSN_OUI_BYTES, RSN_CSE_WRAP },
1136 		{ RSN_OUI_BYTES, RSN_CSE_CCMP },
1137 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1138 		{ RSN_OUI_BYTES, RSN_CSE_NULL },
1139 	};
1140 	static const u_int8_t wep104_suite[4] =
1141 		{ RSN_OUI_BYTES, RSN_CSE_WEP104 };
1142 	static const u_int8_t key_mgt_unspec[4] =
1143 		{ RSN_OUI_BYTES, RSN_ASE_8021X_UNSPEC };
1144 	static const u_int8_t key_mgt_psk[4] =
1145 		{ RSN_OUI_BYTES, RSN_ASE_8021X_PSK };
1146 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1147 	u_int8_t *frm = ie;
1148 	u_int8_t *selcnt;
1149 
1150 	*frm++ = IEEE80211_ELEMID_RSN;
1151 	*frm++ = 0;				/* length filled in below */
1152 	ADDSHORT(frm, RSN_VERSION);
1153 
1154 	/* XXX filter out CKIP */
1155 
1156 	/* multicast cipher */
1157 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1158 	    rsn->rsn_mcastkeylen >= 13)
1159 		ADDSELECTOR(frm, wep104_suite);
1160 	else
1161 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1162 
1163 	/* unicast cipher list */
1164 	selcnt = frm;
1165 	ADDSHORT(frm, 0);			/* selector count */
1166 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1167 		selcnt[0]++;
1168 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1169 	}
1170 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1171 		selcnt[0]++;
1172 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1173 	}
1174 
1175 	/* authenticator selector list */
1176 	selcnt = frm;
1177 	ADDSHORT(frm, 0);			/* selector count */
1178 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1179 		selcnt[0]++;
1180 		ADDSELECTOR(frm, key_mgt_unspec);
1181 	}
1182 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1183 		selcnt[0]++;
1184 		ADDSELECTOR(frm, key_mgt_psk);
1185 	}
1186 
1187 	/* optional capabilities */
1188 	ADDSHORT(frm, rsn->rsn_caps);
1189 	/* XXX PMKID */
1190 
1191 	/* calculate element length */
1192 	ie[1] = frm - ie - 2;
1193 	IASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1194 		("RSN IE too big, %u > %zu",
1195 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1196 	return frm;
1197 #undef ADDSELECTOR
1198 #undef ADDSHORT
1199 #undef RSN_OUI_BYTES
1200 }
1201 
1202 /*
1203  * Add a WPA/RSN element to a frame.
1204  */
1205 static u_int8_t *
1206 ieee80211_add_wpa(u_int8_t *frm, struct ieee80211com *ic)
1207 {
1208 
1209 	IASSERT(ic->ic_flags & IEEE80211_F_WPA, ("no WPA/RSN!"));
1210 	if (ic->ic_flags & IEEE80211_F_WPA2)
1211 		frm = ieee80211_setup_rsn_ie(ic, frm);
1212 	if (ic->ic_flags & IEEE80211_F_WPA1)
1213 		frm = ieee80211_setup_wpa_ie(ic, frm);
1214 	return frm;
1215 }
1216 
1217 #define	WME_OUI_BYTES		0x00, 0x50, 0xf2
1218 /*
1219  * Add a WME information element to a frame.
1220  */
1221 static u_int8_t *
1222 ieee80211_add_wme_info(u_int8_t *frm, struct ieee80211_wme_state *wme)
1223 {
1224 	static const struct ieee80211_wme_info info = {
1225 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1226 		.wme_len	= sizeof(struct ieee80211_wme_info) - 2,
1227 		.wme_oui	= { WME_OUI_BYTES },
1228 		.wme_type	= WME_OUI_TYPE,
1229 		.wme_subtype	= WME_INFO_OUI_SUBTYPE,
1230 		.wme_version	= WME_VERSION,
1231 		.wme_info	= 0,
1232 	};
1233 	memcpy(frm, &info, sizeof(info));
1234 	return frm + sizeof(info);
1235 }
1236 
1237 /*
1238  * Add a WME parameters element to a frame.
1239  */
1240 static u_int8_t *
1241 ieee80211_add_wme_param(u_int8_t *frm, struct ieee80211_wme_state *wme)
1242 {
1243 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
1244 #define	ADDSHORT(frm, v) do {			\
1245 	frm[0] = (v) & 0xff;			\
1246 	frm[1] = (v) >> 8;			\
1247 	frm += 2;				\
1248 } while (0)
1249 	/* NB: this works 'cuz a param has an info at the front */
1250 	static const struct ieee80211_wme_info param = {
1251 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1252 		.wme_len	= sizeof(struct ieee80211_wme_param) - 2,
1253 		.wme_oui	= { WME_OUI_BYTES },
1254 		.wme_type	= WME_OUI_TYPE,
1255 		.wme_subtype	= WME_PARAM_OUI_SUBTYPE,
1256 		.wme_version	= WME_VERSION,
1257 	};
1258 	int i;
1259 
1260 	memcpy(frm, &param, sizeof(param));
1261 	frm += __offsetof(struct ieee80211_wme_info, wme_info);
1262 	*frm++ = wme->wme_bssChanParams.cap_info;	/* AC info */
1263 	*frm++ = 0;					/* reserved field */
1264 	for (i = 0; i < WME_NUM_AC; i++) {
1265 		const struct wmeParams *ac =
1266 		       &wme->wme_bssChanParams.cap_wmeParams[i];
1267 		*frm++ = SM(i, WME_PARAM_ACI)
1268 		       | SM(ac->wmep_acm, WME_PARAM_ACM)
1269 		       | SM(ac->wmep_aifsn, WME_PARAM_AIFSN)
1270 		       ;
1271 		*frm++ = SM(ac->wmep_logcwmax, WME_PARAM_LOGCWMAX)
1272 		       | SM(ac->wmep_logcwmin, WME_PARAM_LOGCWMIN)
1273 		       ;
1274 		ADDSHORT(frm, ac->wmep_txopLimit);
1275 	}
1276 	return frm;
1277 #undef SM
1278 #undef ADDSHORT
1279 }
1280 #undef WME_OUI_BYTES
1281 
1282 /*
1283  * Send a probe request frame with the specified ssid
1284  * and any optional information element data.
1285  */
1286 int
1287 ieee80211_send_probereq(struct ieee80211_node *ni,
1288 	const u_int8_t sa[IEEE80211_ADDR_LEN],
1289 	const u_int8_t da[IEEE80211_ADDR_LEN],
1290 	const u_int8_t bssid[IEEE80211_ADDR_LEN],
1291 	const u_int8_t *ssid, size_t ssidlen,
1292 	const void *optie, size_t optielen)
1293 {
1294 	struct ieee80211com *ic = ni->ni_ic;
1295 	enum ieee80211_phymode mode;
1296 	struct ieee80211_frame *wh;
1297 	struct mbuf *m;
1298 	u_int8_t *frm;
1299 
1300 	/*
1301 	 * Hold a reference on the node so it doesn't go away until after
1302 	 * the xmit is complete all the way in the driver.  On error we
1303 	 * will remove our reference.
1304 	 */
1305 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1306 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1307 		__func__, __LINE__,
1308 		ni, ether_sprintf(ni->ni_macaddr),
1309 		ieee80211_node_refcnt(ni)+1);
1310 	ieee80211_ref_node(ni);
1311 
1312 	/*
1313 	 * prreq frame format
1314 	 *	[tlv] ssid
1315 	 *	[tlv] supported rates
1316 	 *	[tlv] extended supported rates
1317 	 *	[tlv] user-specified ie's
1318 	 */
1319 	m = ieee80211_getmgtframe(&frm,
1320 		 2 + IEEE80211_NWID_LEN
1321 	       + 2 + IEEE80211_RATE_SIZE
1322 	       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1323 	       + (optie != NULL ? optielen : 0)
1324 	);
1325 	if (m == NULL) {
1326 		ic->ic_stats.is_tx_nobuf++;
1327 		ieee80211_free_node(ni);
1328 		return ENOMEM;
1329 	}
1330 
1331 	frm = ieee80211_add_ssid(frm, ssid, ssidlen);
1332 	mode = ieee80211_chan2mode(ic, ic->ic_curchan);
1333 	frm = ieee80211_add_rates(frm, &ic->ic_sup_rates[mode]);
1334 	frm = ieee80211_add_xrates(frm, &ic->ic_sup_rates[mode]);
1335 
1336 	if (optie != NULL) {
1337 		memcpy(frm, optie, optielen);
1338 		frm += optielen;
1339 	}
1340 	m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1341 
1342 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1343 	if (m == NULL)
1344 		return ENOMEM;
1345 	IASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
1346 	m->m_pkthdr.rcvif = (void *)ni;
1347 
1348 	wh = mtod(m, struct ieee80211_frame *);
1349 	ieee80211_send_setup(ic, ni, wh,
1350 		IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_PROBE_REQ,
1351 		sa, da, bssid);
1352 	/* XXX power management? */
1353 
1354 	IEEE80211_NODE_STAT(ni, tx_probereq);
1355 	IEEE80211_NODE_STAT(ni, tx_mgmt);
1356 
1357 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
1358 	    "[%s] send probe req on channel %u\n",
1359 	    ether_sprintf(wh->i_addr1),
1360 	    ieee80211_chan2ieee(ic, ic->ic_curchan));
1361 
1362 	IF_ENQUEUE(&ic->ic_mgtq, m);
1363 	(*ic->ic_ifp->if_start)(ic->ic_ifp);
1364 	return 0;
1365 }
1366 
1367 /*
1368  * Send a management frame.  The node is for the destination (or ic_bss
1369  * when in station mode).  Nodes other than ic_bss have their reference
1370  * count bumped to reflect our use for an indeterminant time.
1371  */
1372 int
1373 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
1374 	int type, int arg)
1375 {
1376 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
1377 	struct mbuf *m;
1378 	u_int8_t *frm;
1379 	u_int16_t capinfo;
1380 	int has_challenge, is_shared_key, ret, timer, status;
1381 
1382 	IASSERT(ni != NULL, ("null node"));
1383 
1384 	/*
1385 	 * Hold a reference on the node so it doesn't go away until after
1386 	 * the xmit is complete all the way in the driver.  On error we
1387 	 * will remove our reference.
1388 	 */
1389 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1390 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1391 		__func__, __LINE__,
1392 		ni, ether_sprintf(ni->ni_macaddr),
1393 		ieee80211_node_refcnt(ni)+1);
1394 	ieee80211_ref_node(ni);
1395 
1396 	timer = 0;
1397 	switch (type) {
1398 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1399 		/*
1400 		 * probe response frame format
1401 		 *	[8] time stamp
1402 		 *	[2] beacon interval
1403 		 *	[2] cabability information
1404 		 *	[tlv] ssid
1405 		 *	[tlv] supported rates
1406 		 *	[tlv] parameter set (FH/DS)
1407 		 *	[tlv] parameter set (IBSS)
1408 		 *	[tlv] extended rate phy (ERP)
1409 		 *	[tlv] extended supported rates
1410 		 *	[tlv] WPA
1411 		 *	[tlv] WME (optional)
1412 		 */
1413 		m = ieee80211_getmgtframe(&frm,
1414 			 8
1415 		       + sizeof(u_int16_t)
1416 		       + sizeof(u_int16_t)
1417 		       + 2 + IEEE80211_NWID_LEN
1418 		       + 2 + IEEE80211_RATE_SIZE
1419 		       + 7	/* max(7,3) */
1420 		       + 6
1421 		       + 3
1422 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1423 		       /* XXX !WPA1+WPA2 fits w/o a cluster */
1424 		       + (ic->ic_flags & IEEE80211_F_WPA ?
1425 				2*sizeof(struct ieee80211_ie_wpa) : 0)
1426 		       + sizeof(struct ieee80211_wme_param)
1427 		);
1428 		if (m == NULL)
1429 			senderr(ENOMEM, is_tx_nobuf);
1430 
1431 		memset(frm, 0, 8);	/* timestamp should be filled later */
1432 		frm += 8;
1433 		*(u_int16_t *)frm = htole16(ic->ic_bss->ni_intval);
1434 		frm += 2;
1435 		if (ic->ic_opmode == IEEE80211_M_IBSS)
1436 			capinfo = IEEE80211_CAPINFO_IBSS;
1437 		else
1438 			capinfo = IEEE80211_CAPINFO_ESS;
1439 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1440 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1441 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1442 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1443 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1444 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
1445 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1446 		*(u_int16_t *)frm = htole16(capinfo);
1447 		frm += 2;
1448 
1449 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
1450 				ic->ic_bss->ni_esslen);
1451 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1452 
1453 		if (ic->ic_phytype == IEEE80211_T_FH) {
1454                         *frm++ = IEEE80211_ELEMID_FHPARMS;
1455                         *frm++ = 5;
1456                         *frm++ = ni->ni_fhdwell & 0x00ff;
1457                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
1458                         *frm++ = IEEE80211_FH_CHANSET(
1459 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1460                         *frm++ = IEEE80211_FH_CHANPAT(
1461 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1462                         *frm++ = ni->ni_fhindex;
1463 		} else {
1464 			*frm++ = IEEE80211_ELEMID_DSPARMS;
1465 			*frm++ = 1;
1466 			*frm++ = ieee80211_chan2ieee(ic, ic->ic_curchan);
1467 		}
1468 
1469 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
1470 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1471 			*frm++ = 2;
1472 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1473 		}
1474 		if (ic->ic_flags & IEEE80211_F_WPA)
1475 			frm = ieee80211_add_wpa(frm, ic);
1476 		if (ic->ic_curmode == IEEE80211_MODE_11G)
1477 			frm = ieee80211_add_erp(frm, ic);
1478 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1479 		if (ic->ic_flags & IEEE80211_F_WME)
1480 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1481 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1482 		break;
1483 
1484 	case IEEE80211_FC0_SUBTYPE_AUTH:
1485 		status = arg >> 16;
1486 		arg &= 0xffff;
1487 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
1488 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
1489 		    ni->ni_challenge != NULL);
1490 
1491 		/*
1492 		 * Deduce whether we're doing open authentication or
1493 		 * shared key authentication.  We do the latter if
1494 		 * we're in the middle of a shared key authentication
1495 		 * handshake or if we're initiating an authentication
1496 		 * request and configured to use shared key.
1497 		 */
1498 		is_shared_key = has_challenge ||
1499 		     arg >= IEEE80211_AUTH_SHARED_RESPONSE ||
1500 		     (arg == IEEE80211_AUTH_SHARED_REQUEST &&
1501 		      ic->ic_bss->ni_authmode == IEEE80211_AUTH_SHARED);
1502 
1503 		m = ieee80211_getmgtframe(&frm,
1504 			  3 * sizeof(u_int16_t)
1505 			+ (has_challenge && status == IEEE80211_STATUS_SUCCESS ?
1506 				sizeof(u_int16_t)+IEEE80211_CHALLENGE_LEN : 0)
1507 		);
1508 		if (m == NULL)
1509 			senderr(ENOMEM, is_tx_nobuf);
1510 
1511 		((u_int16_t *)frm)[0] =
1512 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
1513 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
1514 		((u_int16_t *)frm)[1] = htole16(arg);	/* sequence number */
1515 		((u_int16_t *)frm)[2] = htole16(status);/* status */
1516 
1517 		if (has_challenge && status == IEEE80211_STATUS_SUCCESS) {
1518 			((u_int16_t *)frm)[3] =
1519 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
1520 			    IEEE80211_ELEMID_CHALLENGE);
1521 			memcpy(&((u_int16_t *)frm)[4], ni->ni_challenge,
1522 			    IEEE80211_CHALLENGE_LEN);
1523 			m->m_pkthdr.len = m->m_len =
1524 				4 * sizeof(u_int16_t) + IEEE80211_CHALLENGE_LEN;
1525 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
1526 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1527 				    "[%s] request encrypt frame (%s)\n",
1528 				    ether_sprintf(ni->ni_macaddr), __func__);
1529 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
1530 			}
1531 		} else
1532 			m->m_pkthdr.len = m->m_len = 3 * sizeof(u_int16_t);
1533 
1534 		/* XXX not right for shared key */
1535 		if (status == IEEE80211_STATUS_SUCCESS)
1536 			IEEE80211_NODE_STAT(ni, tx_auth);
1537 		else
1538 			IEEE80211_NODE_STAT(ni, tx_auth_fail);
1539 
1540 		if (ic->ic_opmode == IEEE80211_M_STA)
1541 			timer = IEEE80211_TRANS_WAIT;
1542 		break;
1543 
1544 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
1545 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1546 			"[%s] send station deauthenticate (reason %d)\n",
1547 			ether_sprintf(ni->ni_macaddr), arg);
1548 		m = ieee80211_getmgtframe(&frm, sizeof(u_int16_t));
1549 		if (m == NULL)
1550 			senderr(ENOMEM, is_tx_nobuf);
1551 		*(u_int16_t *)frm = htole16(arg);	/* reason */
1552 		m->m_pkthdr.len = m->m_len = sizeof(u_int16_t);
1553 
1554 		IEEE80211_NODE_STAT(ni, tx_deauth);
1555 		IEEE80211_NODE_STAT_SET(ni, tx_deauth_code, arg);
1556 
1557 		ieee80211_node_unauthorize(ni);		/* port closed */
1558 		break;
1559 
1560 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1561 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1562 		/*
1563 		 * asreq frame format
1564 		 *	[2] capability information
1565 		 *	[2] listen interval
1566 		 *	[6*] current AP address (reassoc only)
1567 		 *	[tlv] ssid
1568 		 *	[tlv] supported rates
1569 		 *	[tlv] extended supported rates
1570 		 *	[tlv] WME
1571 		 *	[tlv] user-specified ie's
1572 		 */
1573 		m = ieee80211_getmgtframe(&frm,
1574 			 sizeof(u_int16_t)
1575 		       + sizeof(u_int16_t)
1576 		       + IEEE80211_ADDR_LEN
1577 		       + 2 + IEEE80211_NWID_LEN
1578 		       + 2 + IEEE80211_RATE_SIZE
1579 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1580 		       + sizeof(struct ieee80211_wme_info)
1581 		       + (ic->ic_opt_ie != NULL ? ic->ic_opt_ie_len : 0)
1582 		);
1583 		if (m == NULL)
1584 			senderr(ENOMEM, is_tx_nobuf);
1585 
1586 		capinfo = 0;
1587 		if (ic->ic_opmode == IEEE80211_M_IBSS)
1588 			capinfo |= IEEE80211_CAPINFO_IBSS;
1589 		else		/* IEEE80211_M_STA */
1590 			capinfo |= IEEE80211_CAPINFO_ESS;
1591 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1592 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1593 		/*
1594 		 * NB: Some 11a AP's reject the request when
1595 		 *     short premable is set.
1596 		 */
1597 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1598 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1599 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1600 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) &&
1601 		    (ic->ic_caps & IEEE80211_C_SHSLOT))
1602 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1603 		*(u_int16_t *)frm = htole16(capinfo);
1604 		frm += 2;
1605 
1606 		*(u_int16_t *)frm = htole16(ic->ic_lintval);
1607 		frm += 2;
1608 
1609 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
1610 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
1611 			frm += IEEE80211_ADDR_LEN;
1612 		}
1613 
1614 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
1615 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1616 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1617 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1618 			frm = ieee80211_add_wme_info(frm, &ic->ic_wme);
1619 		if (ic->ic_opt_ie != NULL) {
1620 			memcpy(frm, ic->ic_opt_ie, ic->ic_opt_ie_len);
1621 			frm += ic->ic_opt_ie_len;
1622 		}
1623 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1624 
1625 		timer = IEEE80211_TRANS_WAIT;
1626 		break;
1627 
1628 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1629 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1630 		/*
1631 		 * asreq frame format
1632 		 *	[2] capability information
1633 		 *	[2] status
1634 		 *	[2] association ID
1635 		 *	[tlv] supported rates
1636 		 *	[tlv] extended supported rates
1637 		 *	[tlv] WME (if enabled and STA enabled)
1638 		 */
1639 		m = ieee80211_getmgtframe(&frm,
1640 			 sizeof(u_int16_t)
1641 		       + sizeof(u_int16_t)
1642 		       + sizeof(u_int16_t)
1643 		       + 2 + IEEE80211_RATE_SIZE
1644 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1645 		       + sizeof(struct ieee80211_wme_param)
1646 		);
1647 		if (m == NULL)
1648 			senderr(ENOMEM, is_tx_nobuf);
1649 
1650 		capinfo = IEEE80211_CAPINFO_ESS;
1651 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1652 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1653 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1654 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1655 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1656 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
1657 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1658 		*(u_int16_t *)frm = htole16(capinfo);
1659 		frm += 2;
1660 
1661 		*(u_int16_t *)frm = htole16(arg);	/* status */
1662 		frm += 2;
1663 
1664 		if (arg == IEEE80211_STATUS_SUCCESS) {
1665 			*(u_int16_t *)frm = htole16(ni->ni_associd);
1666 			IEEE80211_NODE_STAT(ni, tx_assoc);
1667 		} else
1668 			IEEE80211_NODE_STAT(ni, tx_assoc_fail);
1669 		frm += 2;
1670 
1671 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1672 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1673 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1674 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1675 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1676 		break;
1677 
1678 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
1679 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1680 			"[%s] send station disassociate (reason %d)\n",
1681 			ether_sprintf(ni->ni_macaddr), arg);
1682 		m = ieee80211_getmgtframe(&frm, sizeof(u_int16_t));
1683 		if (m == NULL)
1684 			senderr(ENOMEM, is_tx_nobuf);
1685 		*(u_int16_t *)frm = htole16(arg);	/* reason */
1686 		m->m_pkthdr.len = m->m_len = sizeof(u_int16_t);
1687 
1688 		IEEE80211_NODE_STAT(ni, tx_disassoc);
1689 		IEEE80211_NODE_STAT_SET(ni, tx_disassoc_code, arg);
1690 		break;
1691 
1692 	default:
1693 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1694 			"[%s] invalid mgmt frame type %u\n",
1695 			ether_sprintf(ni->ni_macaddr), type);
1696 		senderr(EINVAL, is_tx_unknownmgt);
1697 		/* NOTREACHED */
1698 	}
1699 	ret = ieee80211_mgmt_output(ic, ni, m, type, timer);
1700 	if (ret != 0) {
1701 bad:
1702 		ieee80211_free_node(ni);
1703 	}
1704 	return ret;
1705 #undef senderr
1706 }
1707 
1708 /*
1709  * Allocate a beacon frame and fillin the appropriate bits.
1710  */
1711 struct mbuf *
1712 ieee80211_beacon_alloc(struct ieee80211com *ic, struct ieee80211_node *ni,
1713 	struct ieee80211_beacon_offsets *bo)
1714 {
1715 	struct ifnet *ifp = ic->ic_ifp;
1716 	struct ieee80211_frame *wh;
1717 	struct mbuf *m;
1718 	int pktlen;
1719 	u_int8_t *frm, *efrm;
1720 	u_int16_t capinfo;
1721 	struct ieee80211_rateset *rs;
1722 
1723 	/*
1724 	 * beacon frame format
1725 	 *	[8] time stamp
1726 	 *	[2] beacon interval
1727 	 *	[2] cabability information
1728 	 *	[tlv] ssid
1729 	 *	[tlv] supported rates
1730 	 *	[3] parameter set (DS)
1731 	 *	[tlv] parameter set (IBSS/TIM)
1732 	 *	[tlv] extended rate phy (ERP)
1733 	 *	[tlv] extended supported rates
1734 	 *	[tlv] WME parameters
1735 	 *	[tlv] WPA/RSN parameters
1736 	 * XXX Vendor-specific OIDs (e.g. Atheros)
1737 	 * NB: we allocate the max space required for the TIM bitmap.
1738 	 */
1739 	rs = &ni->ni_rates;
1740 	pktlen =   8					/* time stamp */
1741 		 + sizeof(u_int16_t)			/* beacon interval */
1742 		 + sizeof(u_int16_t)			/* capabilities */
1743 		 + 2 + ni->ni_esslen			/* ssid */
1744 	         + 2 + IEEE80211_RATE_SIZE		/* supported rates */
1745 	         + 2 + 1				/* DS parameters */
1746 		 + 2 + 4 + ic->ic_tim_len		/* DTIM/IBSSPARMS */
1747 		 + 2 + 1				/* ERP */
1748 	         + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1749 		 + (ic->ic_caps & IEEE80211_C_WME ?	/* WME */
1750 			sizeof(struct ieee80211_wme_param) : 0)
1751 		 + (ic->ic_caps & IEEE80211_C_WPA ?	/* WPA 1+2 */
1752 			2*sizeof(struct ieee80211_ie_wpa) : 0)
1753 		 ;
1754 	m = ieee80211_getmgtframe(&frm, pktlen);
1755 	if (m == NULL) {
1756 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1757 			"%s: cannot get buf; size %u\n", __func__, pktlen);
1758 		ic->ic_stats.is_tx_nobuf++;
1759 		return NULL;
1760 	}
1761 
1762 	memset(frm, 0, 8);	/* XXX timestamp is set by hardware/driver */
1763 	frm += 8;
1764 	*(u_int16_t *)frm = htole16(ni->ni_intval);
1765 	frm += 2;
1766 	if (ic->ic_opmode == IEEE80211_M_IBSS)
1767 		capinfo = IEEE80211_CAPINFO_IBSS;
1768 	else
1769 		capinfo = IEEE80211_CAPINFO_ESS;
1770 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1771 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1772 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1773 	    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
1774 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1775 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1776 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1777 	bo->bo_caps = (u_int16_t *)frm;
1778 	*(u_int16_t *)frm = htole16(capinfo);
1779 	frm += 2;
1780 	*frm++ = IEEE80211_ELEMID_SSID;
1781 	if ((ic->ic_flags & IEEE80211_F_HIDESSID) == 0) {
1782 		*frm++ = ni->ni_esslen;
1783 		memcpy(frm, ni->ni_essid, ni->ni_esslen);
1784 		frm += ni->ni_esslen;
1785 	} else
1786 		*frm++ = 0;
1787 	frm = ieee80211_add_rates(frm, rs);
1788 	if (ic->ic_curmode != IEEE80211_MODE_FH) {
1789 		*frm++ = IEEE80211_ELEMID_DSPARMS;
1790 		*frm++ = 1;
1791 		*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
1792 	}
1793 	bo->bo_tim = frm;
1794 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
1795 		*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1796 		*frm++ = 2;
1797 		*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1798 		bo->bo_tim_len = 0;
1799 	} else {
1800 		struct ieee80211_tim_ie *tie = (struct ieee80211_tim_ie *) frm;
1801 
1802 		tie->tim_ie = IEEE80211_ELEMID_TIM;
1803 		tie->tim_len = 4;	/* length */
1804 		tie->tim_count = 0;	/* DTIM count */
1805 		tie->tim_period = ic->ic_dtim_period;	/* DTIM period */
1806 		tie->tim_bitctl = 0;	/* bitmap control */
1807 		tie->tim_bitmap[0] = 0;	/* Partial Virtual Bitmap */
1808 		frm += sizeof(struct ieee80211_tim_ie);
1809 		bo->bo_tim_len = 1;
1810 	}
1811 	bo->bo_trailer = frm;
1812 	if (ic->ic_flags & IEEE80211_F_WME) {
1813 		bo->bo_wme = frm;
1814 		frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1815 		ic->ic_flags &= ~IEEE80211_F_WMEUPDATE;
1816 	}
1817 	if (ic->ic_flags & IEEE80211_F_WPA)
1818 		frm = ieee80211_add_wpa(frm, ic);
1819 	if (ic->ic_curmode == IEEE80211_MODE_11G)
1820 		frm = ieee80211_add_erp(frm, ic);
1821 	efrm = ieee80211_add_xrates(frm, rs);
1822 	bo->bo_trailer_len = efrm - bo->bo_trailer;
1823 	m->m_pkthdr.len = m->m_len = efrm - mtod(m, u_int8_t *);
1824 
1825 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1826 	IASSERT(m != NULL, ("no space for 802.11 header?"));
1827 	wh = mtod(m, struct ieee80211_frame *);
1828 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
1829 	    IEEE80211_FC0_SUBTYPE_BEACON;
1830 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
1831 	*(u_int16_t *)wh->i_dur = 0;
1832 	IEEE80211_ADDR_COPY(wh->i_addr1, ifp->if_broadcastaddr);
1833 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
1834 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
1835 	*(u_int16_t *)wh->i_seq = 0;
1836 
1837 	return m;
1838 }
1839 
1840 /*
1841  * Update the dynamic parts of a beacon frame based on the current state.
1842  */
1843 int
1844 ieee80211_beacon_update(struct ieee80211com *ic, struct ieee80211_node *ni,
1845     struct ieee80211_beacon_offsets *bo, struct mbuf *m, int mcast)
1846 {
1847 	int len_changed = 0;
1848 	u_int16_t capinfo;
1849 
1850 	IEEE80211_BEACON_LOCK(ic);
1851 	/* XXX faster to recalculate entirely or just changes? */
1852 	if (ic->ic_opmode == IEEE80211_M_IBSS)
1853 		capinfo = IEEE80211_CAPINFO_IBSS;
1854 	else
1855 		capinfo = IEEE80211_CAPINFO_ESS;
1856 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1857 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1858 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1859 	    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
1860 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1861 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1862 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1863 	*bo->bo_caps = htole16(capinfo);
1864 
1865 	if (ic->ic_flags & IEEE80211_F_WME) {
1866 		struct ieee80211_wme_state *wme = &ic->ic_wme;
1867 
1868 		/*
1869 		 * Check for agressive mode change.  When there is
1870 		 * significant high priority traffic in the BSS
1871 		 * throttle back BE traffic by using conservative
1872 		 * parameters.  Otherwise BE uses agressive params
1873 		 * to optimize performance of legacy/non-QoS traffic.
1874 		 */
1875 		if (wme->wme_flags & WME_F_AGGRMODE) {
1876 			if (wme->wme_hipri_traffic >
1877 			    wme->wme_hipri_switch_thresh) {
1878 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
1879 				    "%s: traffic %u, disable aggressive mode\n",
1880 				    __func__, wme->wme_hipri_traffic);
1881 				wme->wme_flags &= ~WME_F_AGGRMODE;
1882 				ieee80211_wme_updateparams_locked(ic);
1883 				wme->wme_hipri_traffic =
1884 					wme->wme_hipri_switch_hysteresis;
1885 			} else
1886 				wme->wme_hipri_traffic = 0;
1887 		} else {
1888 			if (wme->wme_hipri_traffic <=
1889 			    wme->wme_hipri_switch_thresh) {
1890 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
1891 				    "%s: traffic %u, enable aggressive mode\n",
1892 				    __func__, wme->wme_hipri_traffic);
1893 				wme->wme_flags |= WME_F_AGGRMODE;
1894 				ieee80211_wme_updateparams_locked(ic);
1895 				wme->wme_hipri_traffic = 0;
1896 			} else
1897 				wme->wme_hipri_traffic =
1898 					wme->wme_hipri_switch_hysteresis;
1899 		}
1900 		if (ic->ic_flags & IEEE80211_F_WMEUPDATE) {
1901 			(void) ieee80211_add_wme_param(bo->bo_wme, wme);
1902 			ic->ic_flags &= ~IEEE80211_F_WMEUPDATE;
1903 		}
1904 	}
1905 
1906 #ifndef IEEE80211_NO_HOSTAP
1907 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {	/* NB: no IBSS support*/
1908 		struct ieee80211_tim_ie *tie =
1909 			(struct ieee80211_tim_ie *) bo->bo_tim;
1910 		if (ic->ic_flags & IEEE80211_F_TIMUPDATE) {
1911 			u_int timlen, timoff, i;
1912 			/*
1913 			 * ATIM/DTIM needs updating.  If it fits in the
1914 			 * current space allocated then just copy in the
1915 			 * new bits.  Otherwise we need to move any trailing
1916 			 * data to make room.  Note that we know there is
1917 			 * contiguous space because ieee80211_beacon_allocate
1918 			 * insures there is space in the mbuf to write a
1919 			 * maximal-size virtual bitmap (based on ic_max_aid).
1920 			 */
1921 			/*
1922 			 * Calculate the bitmap size and offset, copy any
1923 			 * trailer out of the way, and then copy in the
1924 			 * new bitmap and update the information element.
1925 			 * Note that the tim bitmap must contain at least
1926 			 * one byte and any offset must be even.
1927 			 */
1928 			if (ic->ic_ps_pending != 0) {
1929 				timoff = 128;		/* impossibly large */
1930 				for (i = 0; i < ic->ic_tim_len; i++)
1931 					if (ic->ic_tim_bitmap[i]) {
1932 						timoff = i &~ 1;
1933 						break;
1934 					}
1935 				IASSERT(timoff != 128, ("tim bitmap empty!"));
1936 				for (i = ic->ic_tim_len-1; i >= timoff; i--)
1937 					if (ic->ic_tim_bitmap[i])
1938 						break;
1939 				timlen = 1 + (i - timoff);
1940 			} else {
1941 				timoff = 0;
1942 				timlen = 1;
1943 			}
1944 			if (timlen != bo->bo_tim_len) {
1945 				/* copy up/down trailer */
1946 				ovbcopy(bo->bo_trailer, tie->tim_bitmap+timlen,
1947 					bo->bo_trailer_len);
1948 				bo->bo_trailer = tie->tim_bitmap+timlen;
1949 				bo->bo_wme = bo->bo_trailer;
1950 				bo->bo_tim_len = timlen;
1951 
1952 				/* update information element */
1953 				tie->tim_len = 3 + timlen;
1954 				tie->tim_bitctl = timoff;
1955 				len_changed = 1;
1956 			}
1957 			memcpy(tie->tim_bitmap, ic->ic_tim_bitmap + timoff,
1958 				bo->bo_tim_len);
1959 
1960 			ic->ic_flags &= ~IEEE80211_F_TIMUPDATE;
1961 
1962 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
1963 				"%s: TIM updated, pending %u, off %u, len %u\n",
1964 				__func__, ic->ic_ps_pending, timoff, timlen);
1965 		}
1966 		/* count down DTIM period */
1967 		if (tie->tim_count == 0)
1968 			tie->tim_count = tie->tim_period - 1;
1969 		else
1970 			tie->tim_count--;
1971 		/* update state for buffered multicast frames on DTIM */
1972 		if (mcast && (tie->tim_count == 1 || tie->tim_period == 1))
1973 			tie->tim_bitctl |= 1;
1974 		else
1975 			tie->tim_bitctl &= ~1;
1976 	}
1977 #endif /* !IEEE80211_NO_HOSTAP */
1978 	IEEE80211_BEACON_UNLOCK(ic);
1979 
1980 	return len_changed;
1981 }
1982 
1983 /*
1984  * Save an outbound packet for a node in power-save sleep state.
1985  * The new packet is placed on the node's saved queue, and the TIM
1986  * is changed, if necessary.
1987  */
1988 void
1989 ieee80211_pwrsave(struct ieee80211com *ic, struct ieee80211_node *ni,
1990 		  struct mbuf *m)
1991 {
1992 	int qlen, age;
1993 
1994 	IEEE80211_NODE_SAVEQ_LOCK(ni);
1995 	if (IF_QFULL(&ni->ni_savedq)) {
1996 		IF_DROP(&ni->ni_savedq);
1997 		IEEE80211_NODE_SAVEQ_UNLOCK(ni);
1998 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1999 			"[%s] pwr save q overflow, drops %d (size %d)\n",
2000 			ether_sprintf(ni->ni_macaddr),
2001 			ni->ni_savedq.ifq_drops, IEEE80211_PS_MAX_QUEUE);
2002 #ifdef IEEE80211_DEBUG
2003 		if (ieee80211_msg_dumppkts(ic))
2004 			ieee80211_dump_pkt(mtod(m, void *), m->m_len, -1, -1);
2005 #endif
2006 		m_freem(m);
2007 		return;
2008 	}
2009 	/*
2010 	 * Tag the frame with it's expiry time and insert
2011 	 * it in the queue.  The aging interval is 4 times
2012 	 * the listen interval specified by the station.
2013 	 * Frames that sit around too long are reclaimed
2014 	 * using this information.
2015 	 */
2016 	/* XXX handle overflow? */
2017 	age = ((ni->ni_intval * ic->ic_bintval) << 2) / 1024; /* TU -> secs */
2018 	_IEEE80211_NODE_SAVEQ_ENQUEUE(ni, m, qlen, age);
2019 	IEEE80211_NODE_SAVEQ_UNLOCK(ni);
2020 
2021 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
2022 		"[%s] save frame with age %d, %u now queued\n",
2023 		ether_sprintf(ni->ni_macaddr), age, qlen);
2024 
2025 	if (qlen == 1)
2026 		ic->ic_set_tim(ni, 1);
2027 }
2028