xref: /netbsd-src/sys/net80211/ieee80211_output.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: ieee80211_output.c,v 1.47 2007/03/04 06:03:19 christos 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 1.47 2007/03/04 06:03:19 christos Exp $");
40 #endif
41 
42 #include "opt_inet.h"
43 
44 #ifdef __NetBSD__
45 #include "bpfilter.h"
46 #endif /* __NetBSD__ */
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/mbuf.h>
51 #include <sys/kernel.h>
52 #include <sys/endian.h>
53 #include <sys/errno.h>
54 #include <sys/proc.h>
55 #include <sys/sysctl.h>
56 
57 #include <net/if.h>
58 #include <net/if_llc.h>
59 #include <net/if_media.h>
60 #include <net/if_arp.h>
61 #include <net/if_ether.h>
62 #include <net/if_llc.h>
63 #include <net/if_vlanvar.h>
64 
65 #include <net80211/ieee80211_netbsd.h>
66 #include <net80211/ieee80211_var.h>
67 
68 #if NBPFILTER > 0
69 #include <net/bpf.h>
70 #endif
71 
72 #ifdef INET
73 #include <netinet/in.h>
74 #include <netinet/in_systm.h>
75 #include <netinet/in_var.h>
76 #include <netinet/ip.h>
77 #include <net/if_ether.h>
78 #endif
79 
80 static int ieee80211_fragment(struct ieee80211com *, struct mbuf *,
81 	u_int hdrsize, u_int ciphdrsize, u_int mtu);
82 
83 #ifdef IEEE80211_DEBUG
84 /*
85  * Decide if an outbound management frame should be
86  * printed when debugging is enabled.  This filters some
87  * of the less interesting frames that come frequently
88  * (e.g. beacons).
89  */
90 static __inline int
91 doprint(struct ieee80211com *ic, int subtype)
92 {
93 	switch (subtype) {
94 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
95 		return (ic->ic_opmode == IEEE80211_M_IBSS);
96 	}
97 	return 1;
98 }
99 #endif
100 
101 /*
102  * Set the direction field and address fields of an outgoing
103  * non-QoS frame.  Note this should be called early on in
104  * constructing a frame as it sets i_fc[1]; other bits can
105  * then be or'd in.
106  */
107 static void
108 ieee80211_send_setup(struct ieee80211com *ic,
109 	struct ieee80211_node *ni,
110 	struct ieee80211_frame *wh,
111 	int type,
112 	const u_int8_t sa[IEEE80211_ADDR_LEN],
113 	const u_int8_t da[IEEE80211_ADDR_LEN],
114 	const u_int8_t bssid[IEEE80211_ADDR_LEN])
115 {
116 #define	WH4(wh)	((struct ieee80211_frame_addr4 *)wh)
117 
118 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | type;
119 	if ((type & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_DATA) {
120 		switch (ic->ic_opmode) {
121 		case IEEE80211_M_STA:
122 			wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
123 			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
124 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
125 			IEEE80211_ADDR_COPY(wh->i_addr3, da);
126 			break;
127 		case IEEE80211_M_IBSS:
128 		case IEEE80211_M_AHDEMO:
129 			wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
130 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
131 			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
132 			IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
133 			break;
134 		case IEEE80211_M_HOSTAP:
135 			wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
136 			IEEE80211_ADDR_COPY(wh->i_addr1, da);
137 			IEEE80211_ADDR_COPY(wh->i_addr2, bssid);
138 			IEEE80211_ADDR_COPY(wh->i_addr3, sa);
139 			break;
140 		case IEEE80211_M_MONITOR:	/* NB: to quiet compiler */
141 			break;
142 		}
143 	} else {
144 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
145 		IEEE80211_ADDR_COPY(wh->i_addr1, da);
146 		IEEE80211_ADDR_COPY(wh->i_addr2, sa);
147 		IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
148 	}
149 	*(u_int16_t *)&wh->i_dur[0] = 0;
150 	/* NB: use non-QoS tid */
151 	*(u_int16_t *)&wh->i_seq[0] =
152 	    htole16(ni->ni_txseqs[0] << IEEE80211_SEQ_SEQ_SHIFT);
153 	ni->ni_txseqs[0]++;
154 #undef WH4
155 }
156 
157 /*
158  * Send a management frame to the specified node.  The node pointer
159  * must have a reference as the pointer will be passed to the driver
160  * and potentially held for a long time.  If the frame is successfully
161  * dispatched to the driver, then it is responsible for freeing the
162  * reference (and potentially free'ing up any associated storage).
163  */
164 static int
165 ieee80211_mgmt_output(struct ieee80211com *ic, struct ieee80211_node *ni,
166     struct mbuf *m, int type, int timer)
167 {
168 	struct ifnet *ifp = ic->ic_ifp;
169 	struct ieee80211_frame *wh;
170 
171 	IASSERT(ni != NULL, ("null node"));
172 
173 	/*
174 	 * Yech, hack alert!  We want to pass the node down to the
175 	 * driver's start routine.  If we don't do so then the start
176 	 * routine must immediately look it up again and that can
177 	 * cause a lock order reversal if, for example, this frame
178 	 * is being sent because the station is being timedout and
179 	 * the frame being sent is a DEAUTH message.  We could stick
180 	 * this in an m_tag and tack that on to the mbuf.  However
181 	 * that's rather expensive to do for every frame so instead
182 	 * we stuff it in the rcvif field since outbound frames do
183 	 * not (presently) use this.
184 	 */
185 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
186 	if (m == NULL)
187 		return ENOMEM;
188 #ifdef __FreeBSD__
189 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
190 #endif
191 	m->m_pkthdr.rcvif = (void *)ni;
192 
193 	wh = mtod(m, struct ieee80211_frame *);
194 	ieee80211_send_setup(ic, ni, wh,
195 		IEEE80211_FC0_TYPE_MGT | type,
196 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
197 	if ((m->m_flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
198 		m->m_flags &= ~M_LINK0;
199 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
200 			"[%s] encrypting frame (%s)\n",
201 			ether_sprintf(wh->i_addr1), __func__);
202 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
203 	}
204 #ifdef IEEE80211_DEBUG
205 	/* avoid printing too many frames */
206 	if ((ieee80211_msg_debug(ic) && doprint(ic, type)) ||
207 	    ieee80211_msg_dumppkts(ic)) {
208 		printf("[%s] send %s on channel %u\n",
209 		    ether_sprintf(wh->i_addr1),
210 		    ieee80211_mgt_subtype_name[
211 			(type & IEEE80211_FC0_SUBTYPE_MASK) >>
212 				IEEE80211_FC0_SUBTYPE_SHIFT],
213 		    ieee80211_chan2ieee(ic, ic->ic_curchan));
214 	}
215 #endif
216 	IEEE80211_NODE_STAT(ni, tx_mgmt);
217 	IF_ENQUEUE(&ic->ic_mgtq, m);
218 	if (timer) {
219 		/*
220 		 * Set the mgt frame timeout.
221 		 */
222 		ic->ic_mgt_timer = timer;
223 		ifp->if_timer = 1;
224 	}
225 	(*ifp->if_start)(ifp);
226 	return 0;
227 }
228 
229 /*
230  * Send a null data frame to the specified node.
231  *
232  * NB: the caller is assumed to have setup a node reference
233  *     for use; this is necessary to deal with a race condition
234  *     when probing for inactive stations.
235  */
236 int
237 ieee80211_send_nulldata(struct ieee80211_node *ni)
238 {
239 	struct ieee80211com *ic = ni->ni_ic;
240 	struct ifnet *ifp = ic->ic_ifp;
241 	struct mbuf *m;
242 	struct ieee80211_frame *wh;
243 
244 	MGETHDR(m, M_NOWAIT, MT_HEADER);
245 	if (m == NULL) {
246 		/* XXX debug msg */
247 		ic->ic_stats.is_tx_nobuf++;
248 		ieee80211_unref_node(&ni);
249 		return ENOMEM;
250 	}
251 	m->m_pkthdr.rcvif = (void *) ni;
252 
253 	wh = mtod(m, struct ieee80211_frame *);
254 	ieee80211_send_setup(ic, ni, wh,
255 		IEEE80211_FC0_TYPE_DATA | IEEE80211_FC0_SUBTYPE_NODATA,
256 		ic->ic_myaddr, ni->ni_macaddr, ni->ni_bssid);
257 	/* NB: power management bit is never sent by an AP */
258 	if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) &&
259 	    ic->ic_opmode != IEEE80211_M_HOSTAP)
260 		wh->i_fc[1] |= IEEE80211_FC1_PWR_MGT;
261 	m->m_len = m->m_pkthdr.len = sizeof(struct ieee80211_frame);
262 
263 	IEEE80211_NODE_STAT(ni, tx_data);
264 
265 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
266 	    "[%s] send null data frame on channel %u, pwr mgt %s\n",
267 	    ether_sprintf(ni->ni_macaddr),
268 	    ieee80211_chan2ieee(ic, ic->ic_curchan),
269 	    wh->i_fc[1] & IEEE80211_FC1_PWR_MGT ? "ena" : "dis");
270 
271 	IF_ENQUEUE(&ic->ic_mgtq, m);		/* cheat */
272 	(*ifp->if_start)(ifp);
273 
274 	return 0;
275 }
276 
277 /*
278  * Assign priority to a frame based on any vlan tag assigned
279  * to the station and/or any Diffserv setting in an IP header.
280  * Finally, if an ACM policy is setup (in station mode) it's
281  * applied.
282  */
283 int
284 ieee80211_classify(struct ieee80211com *ic, struct mbuf *m, struct ieee80211_node *ni)
285 {
286 	int v_wme_ac, d_wme_ac, ac;
287 #ifdef INET
288 	struct ether_header *eh;
289 #endif
290 
291 	if ((ni->ni_flags & IEEE80211_NODE_QOS) == 0) {
292 		ac = WME_AC_BE;
293 		goto done;
294 	}
295 
296 	/*
297 	 * If node has a vlan tag then all traffic
298 	 * to it must have a matching tag.
299 	 */
300 	v_wme_ac = 0;
301 	if (ni->ni_vlan != 0) {
302 		/* XXX used to check ec_nvlans. */
303 		struct m_tag *mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL);
304 		if (mtag == NULL) {
305 			IEEE80211_NODE_STAT(ni, tx_novlantag);
306 			return 1;
307 		}
308 		if (EVL_VLANOFTAG(VLAN_TAG_VALUE(mtag)) !=
309 		    EVL_VLANOFTAG(ni->ni_vlan)) {
310 			IEEE80211_NODE_STAT(ni, tx_vlanmismatch);
311 			return 1;
312 		}
313 		/* map vlan priority to AC */
314 		switch (EVL_PRIOFTAG(ni->ni_vlan)) {
315 		case 1:
316 		case 2:
317 			v_wme_ac = WME_AC_BK;
318 			break;
319 		case 0:
320 		case 3:
321 			v_wme_ac = WME_AC_BE;
322 			break;
323 		case 4:
324 		case 5:
325 			v_wme_ac = WME_AC_VI;
326 			break;
327 		case 6:
328 		case 7:
329 			v_wme_ac = WME_AC_VO;
330 			break;
331 		}
332 	}
333 
334 #ifdef INET
335 	eh = mtod(m, struct ether_header *);
336 	if (eh->ether_type == htons(ETHERTYPE_IP)) {
337 		const struct ip *ip = (struct ip *)
338 			(mtod(m, u_int8_t *) + sizeof (*eh));
339 		/*
340 		 * IP frame, map the TOS field.
341 		 */
342 		switch (ip->ip_tos) {
343 		case 0x08:
344 		case 0x20:
345 			d_wme_ac = WME_AC_BK;	/* background */
346 			break;
347 		case 0x28:
348 		case 0xa0:
349 			d_wme_ac = WME_AC_VI;	/* video */
350 			break;
351 		case 0x30:			/* voice */
352 		case 0xe0:
353 		case 0x88:			/* XXX UPSD */
354 		case 0xb8:
355 			d_wme_ac = WME_AC_VO;
356 			break;
357 		default:
358 			d_wme_ac = WME_AC_BE;
359 			break;
360 		}
361 	} else {
362 #endif /* INET */
363 		d_wme_ac = WME_AC_BE;
364 #ifdef INET
365 	}
366 #endif
367 	/*
368 	 * Use highest priority AC.
369 	 */
370 	if (v_wme_ac > d_wme_ac)
371 		ac = v_wme_ac;
372 	else
373 		ac = d_wme_ac;
374 
375 	/*
376 	 * Apply ACM policy.
377 	 */
378 	if (ic->ic_opmode == IEEE80211_M_STA) {
379 		static const int acmap[4] = {
380 			WME_AC_BK,	/* WME_AC_BE */
381 			WME_AC_BK,	/* WME_AC_BK */
382 			WME_AC_BE,	/* WME_AC_VI */
383 			WME_AC_VI,	/* WME_AC_VO */
384 		};
385 		while (ac != WME_AC_BK &&
386 		    ic->ic_wme.wme_wmeBssChanParams.cap_wmeParams[ac].wmep_acm)
387 			ac = acmap[ac];
388 	}
389 done:
390 	M_WME_SETAC(m, ac);
391 	return 0;
392 }
393 
394 /*
395  * Insure there is sufficient contiguous space to encapsulate the
396  * 802.11 data frame.  If room isn't already there, arrange for it.
397  * Drivers and cipher modules assume we have done the necessary work
398  * and fail rudely if they don't find the space they need.
399  */
400 static struct mbuf *
401 ieee80211_mbuf_adjust(struct ieee80211com *ic, int hdrsize,
402 	struct ieee80211_key *key, struct mbuf *m)
403 {
404 #define	TO_BE_RECLAIMED	(sizeof(struct ether_header) - sizeof(struct llc))
405 	int needed_space = hdrsize;
406 	int wlen = 0;
407 
408 	if (key != NULL) {
409 		/* XXX belongs in crypto code? */
410 		needed_space += key->wk_cipher->ic_header;
411 		/* XXX frags */
412 	}
413 	/*
414 	 * We know we are called just before stripping an Ethernet
415 	 * header and prepending an LLC header.  This means we know
416 	 * there will be
417 	 *	sizeof(struct ether_header) - sizeof(struct llc)
418 	 * bytes recovered to which we need additional space for the
419 	 * 802.11 header and any crypto header.
420 	 */
421 	/* XXX check trailing space and copy instead? */
422 	if (M_LEADINGSPACE(m) < needed_space - TO_BE_RECLAIMED) {
423 		struct mbuf *n = m_gethdr(M_NOWAIT, m->m_type);
424 		if (n == NULL) {
425 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
426 			    "%s: cannot expand storage\n", __func__);
427 			ic->ic_stats.is_tx_nobuf++;
428 			m_freem(m);
429 			return NULL;
430 		}
431 		IASSERT(needed_space <= MHLEN,
432 		    ("not enough room, need %u got %zu\n", needed_space, MHLEN));
433 		/*
434 		 * Setup new mbuf to have leading space to prepend the
435 		 * 802.11 header and any crypto header bits that are
436 		 * required (the latter are added when the driver calls
437 		 * back to ieee80211_crypto_encap to do crypto encapsulation).
438 		 */
439 		/* NB: must be first 'cuz it clobbers m_data */
440 		M_MOVE_PKTHDR(n, m);
441 		n->m_len = 0;			/* NB: m_gethdr does not set */
442 		n->m_data += needed_space;
443 		/*
444 		 * Pull up Ethernet header to create the expected layout.
445 		 * We could use m_pullup but that's overkill (i.e. we don't
446 		 * need the actual data) and it cannot fail so do it inline
447 		 * for speed.
448 		 */
449 		/* NB: struct ether_header is known to be contiguous */
450 		n->m_len += sizeof(struct ether_header);
451 		m->m_len -= sizeof(struct ether_header);
452 		m->m_data += sizeof(struct ether_header);
453 		/*
454 		 * Replace the head of the chain.
455 		 */
456 		n->m_next = m;
457 		m = n;
458 	} else {
459                 /* We will overwrite the ethernet header in the
460                  * 802.11 encapsulation stage.  Make sure that it
461                  * is writable.
462 		 */
463 		wlen = sizeof(struct ether_header);
464 	}
465 
466 	/*
467 	 * If we're going to s/w encrypt the mbuf chain make sure it is
468 	 * writable.
469 	 */
470 	if (key != NULL && (key->wk_flags & IEEE80211_KEY_SWCRYPT) != 0)
471 		wlen = M_COPYALL;
472 
473 	if (wlen != 0 && m_makewritable(&m, 0, wlen, M_DONTWAIT) != 0) {
474 		m_freem(m);
475 		return NULL;
476 	}
477 	return m;
478 #undef TO_BE_RECLAIMED
479 }
480 
481 /*
482  * Return the transmit key to use in sending a unicast frame.
483  * If a unicast key is set we use that.  When no unicast key is set
484  * we fall back to the default transmit key.
485  */
486 static __inline struct ieee80211_key *
487 ieee80211_crypto_getucastkey(struct ieee80211com *ic, struct ieee80211_node *ni)
488 {
489 	if (IEEE80211_KEY_UNDEFINED(ni->ni_ucastkey)) {
490 		if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
491 		    IEEE80211_KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
492 			return NULL;
493 		return &ic->ic_nw_keys[ic->ic_def_txkey];
494 	} else {
495 		return &ni->ni_ucastkey;
496 	}
497 }
498 
499 /*
500  * Return the transmit key to use in sending a multicast frame.
501  * Multicast traffic always uses the group key which is installed as
502  * the default tx key.
503  */
504 static __inline struct ieee80211_key *
505 ieee80211_crypto_getmcastkey(struct ieee80211com *ic,
506     struct ieee80211_node *ni)
507 {
508 	if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
509 	    IEEE80211_KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
510 		return NULL;
511 	return &ic->ic_nw_keys[ic->ic_def_txkey];
512 }
513 
514 /*
515  * Encapsulate an outbound data frame.  The mbuf chain is updated.
516  * If an error is encountered NULL is returned.  The caller is required
517  * to provide a node reference and pullup the ethernet header in the
518  * first mbuf.
519  */
520 struct mbuf *
521 ieee80211_encap(struct ieee80211com *ic, struct mbuf *m,
522 	struct ieee80211_node *ni)
523 {
524 	struct ether_header eh;
525 	struct ieee80211_frame *wh;
526 	struct ieee80211_key *key;
527 	struct llc *llc;
528 	int hdrsize, datalen, addqos, txfrag;
529 
530 	IASSERT(m->m_len >= sizeof(eh), ("no ethernet header!"));
531 	memcpy(&eh, mtod(m, void *), sizeof(struct ether_header));
532 
533 	/*
534 	 * Insure space for additional headers.  First identify
535 	 * transmit key to use in calculating any buffer adjustments
536 	 * required.  This is also used below to do privacy
537 	 * encapsulation work.  Then calculate the 802.11 header
538 	 * size and any padding required by the driver.
539 	 *
540 	 * Note key may be NULL if we fall back to the default
541 	 * transmit key and that is not set.  In that case the
542 	 * buffer may not be expanded as needed by the cipher
543 	 * routines, but they will/should discard it.
544 	 */
545 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
546 		if (ic->ic_opmode == IEEE80211_M_STA ||
547 		    !IEEE80211_IS_MULTICAST(eh.ether_dhost))
548 			key = ieee80211_crypto_getucastkey(ic, ni);
549 		else
550 			key = ieee80211_crypto_getmcastkey(ic, ni);
551 		if (key == NULL && eh.ether_type != htons(ETHERTYPE_PAE)) {
552 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
553 			    "[%s] no default transmit key (%s) deftxkey %u\n",
554 			    ether_sprintf(eh.ether_dhost), __func__,
555 			    ic->ic_def_txkey);
556 			ic->ic_stats.is_tx_nodefkey++;
557 		}
558 	} else
559 		key = NULL;
560 	/* XXX 4-address format */
561 	/*
562 	 * XXX Some ap's don't handle QoS-encapsulated EAPOL
563 	 * frames so suppress use.  This may be an issue if other
564 	 * ap's require all data frames to be QoS-encapsulated
565 	 * once negotiated in which case we'll need to make this
566 	 * configurable.
567 	 */
568 	addqos = (ni->ni_flags & IEEE80211_NODE_QOS) &&
569 		 eh.ether_type != htons(ETHERTYPE_PAE);
570 	if (addqos)
571 		hdrsize = sizeof(struct ieee80211_qosframe);
572 	else
573 		hdrsize = sizeof(struct ieee80211_frame);
574 	if (ic->ic_flags & IEEE80211_F_DATAPAD)
575 		hdrsize = roundup(hdrsize, sizeof(u_int32_t));
576 	m = ieee80211_mbuf_adjust(ic, hdrsize, key, m);
577 	if (m == NULL) {
578 		/* NB: ieee80211_mbuf_adjust handles msgs+statistics */
579 		goto bad;
580 	}
581 
582 	/* NB: this could be optimized because of ieee80211_mbuf_adjust */
583 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
584 	llc = mtod(m, struct llc *);
585 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
586 	llc->llc_control = LLC_UI;
587 	llc->llc_snap.org_code[0] = 0;
588 	llc->llc_snap.org_code[1] = 0;
589 	llc->llc_snap.org_code[2] = 0;
590 	llc->llc_snap.ether_type = eh.ether_type;
591 	datalen = m->m_pkthdr.len;		/* NB: w/o 802.11 header */
592 
593 	M_PREPEND(m, hdrsize, M_DONTWAIT);
594 	if (m == NULL) {
595 		ic->ic_stats.is_tx_nobuf++;
596 		goto bad;
597 	}
598 	wh = mtod(m, struct ieee80211_frame *);
599 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
600 	*(u_int16_t *)wh->i_dur = 0;
601 	switch (ic->ic_opmode) {
602 	case IEEE80211_M_STA:
603 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
604 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
605 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
606 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
607 		break;
608 	case IEEE80211_M_IBSS:
609 	case IEEE80211_M_AHDEMO:
610 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
611 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
612 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
613 		/*
614 		 * NB: always use the bssid from ic_bss as the
615 		 *     neighbor's may be stale after an ibss merge
616 		 */
617 		IEEE80211_ADDR_COPY(wh->i_addr3, ic->ic_bss->ni_bssid);
618 		break;
619 	case IEEE80211_M_HOSTAP:
620 #ifndef IEEE80211_NO_HOSTAP
621 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
622 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
623 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
624 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
625 #endif /* !IEEE80211_NO_HOSTAP */
626 		break;
627 	case IEEE80211_M_MONITOR:
628 		goto bad;
629 	}
630 	if (m->m_flags & M_MORE_DATA)
631 		wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
632 	if (addqos) {
633 		struct ieee80211_qosframe *qwh =
634 			(struct ieee80211_qosframe *) wh;
635 		int ac, tid;
636 
637 		ac = M_WME_GETAC(m);
638 		/* map from access class/queue to 11e header priorty value */
639 		tid = WME_AC_TO_TID(ac);
640 		qwh->i_qos[0] = tid & IEEE80211_QOS_TID;
641 		if (ic->ic_wme.wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy)
642 			qwh->i_qos[0] |= 1 << IEEE80211_QOS_ACKPOLICY_S;
643 		qwh->i_qos[1] = 0;
644 		qwh->i_fc[0] |= IEEE80211_FC0_SUBTYPE_QOS;
645 
646 		*(u_int16_t *)wh->i_seq =
647 		    htole16(ni->ni_txseqs[tid] << IEEE80211_SEQ_SEQ_SHIFT);
648 		ni->ni_txseqs[tid]++;
649 	} else {
650 		*(u_int16_t *)wh->i_seq =
651 		    htole16(ni->ni_txseqs[0] << IEEE80211_SEQ_SEQ_SHIFT);
652 		ni->ni_txseqs[0]++;
653 	}
654 	/* check if xmit fragmentation is required */
655 	txfrag = (m->m_pkthdr.len > ic->ic_fragthreshold &&
656 	    !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
657 	    (m->m_flags & M_FF) == 0);          /* NB: don't fragment ff's */
658 	if (key != NULL) {
659 		/*
660 		 * IEEE 802.1X: send EAPOL frames always in the clear.
661 		 * WPA/WPA2: encrypt EAPOL keys when pairwise keys are set.
662 		 */
663 		if (eh.ether_type != htons(ETHERTYPE_PAE) ||
664 		    ((ic->ic_flags & IEEE80211_F_WPA) &&
665 		     (ic->ic_opmode == IEEE80211_M_STA ?
666 		      !IEEE80211_KEY_UNDEFINED(*key) :
667 		      !IEEE80211_KEY_UNDEFINED(ni->ni_ucastkey)))) {
668 			wh->i_fc[1] |= IEEE80211_FC1_WEP;
669 			if (!ieee80211_crypto_enmic(ic, key, m, txfrag)) {
670 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
671 				    "[%s] enmic failed, discard frame\n",
672 				    ether_sprintf(eh.ether_dhost));
673 				ic->ic_stats.is_crypto_enmicfail++;
674 				goto bad;
675 			}
676 		}
677 	}
678 	if (txfrag && !ieee80211_fragment(ic, m, hdrsize,
679 	    key != NULL ? key->wk_cipher->ic_header : 0, ic->ic_fragthreshold))
680 		goto bad;
681 
682 	IEEE80211_NODE_STAT(ni, tx_data);
683 	IEEE80211_NODE_STAT_ADD(ni, tx_bytes, datalen);
684 
685 	return m;
686 bad:
687 	if (m != NULL)
688 		m_freem(m);
689 	return NULL;
690 }
691 
692 /*
693  * Arguments in:
694  *
695  * paylen:  payload length (no FCS, no WEP header)
696  *
697  * hdrlen:  header length
698  *
699  * rate:    MSDU speed, units 500kb/s
700  *
701  * flags:   IEEE80211_F_SHPREAMBLE (use short preamble),
702  *          IEEE80211_F_SHSLOT (use short slot length)
703  *
704  * Arguments out:
705  *
706  * d:       802.11 Duration field for RTS,
707  *          802.11 Duration field for data frame,
708  *          PLCP Length for data frame,
709  *          residual octets at end of data slot
710  */
711 static int
712 ieee80211_compute_duration1(int len, int use_ack, uint32_t icflags, int rate,
713     struct ieee80211_duration *d)
714 {
715 	int pre, ctsrate;
716 	int ack, bitlen, data_dur, remainder;
717 
718 	/* RTS reserves medium for SIFS | CTS | SIFS | (DATA) | SIFS | ACK
719 	 * DATA reserves medium for SIFS | ACK
720 	 *
721 	 * XXXMYC: no ACK on multicast/broadcast or control packets
722 	 */
723 
724 	bitlen = len * 8;
725 
726 	pre = IEEE80211_DUR_DS_SIFS;
727 	if ((icflags & IEEE80211_F_SHPREAMBLE) != 0)
728 		pre += IEEE80211_DUR_DS_SHORT_PREAMBLE + IEEE80211_DUR_DS_FAST_PLCPHDR;
729 	else
730 		pre += IEEE80211_DUR_DS_LONG_PREAMBLE + IEEE80211_DUR_DS_SLOW_PLCPHDR;
731 
732 	d->d_residue = 0;
733 	data_dur = (bitlen * 2) / rate;
734 	remainder = (bitlen * 2) % rate;
735 	if (remainder != 0) {
736 		d->d_residue = (rate - remainder) / 16;
737 		data_dur++;
738 	}
739 
740 	switch (rate) {
741 	case 2:		/* 1 Mb/s */
742 	case 4:		/* 2 Mb/s */
743 		/* 1 - 2 Mb/s WLAN: send ACK/CTS at 1 Mb/s */
744 		ctsrate = 2;
745 		break;
746 	case 11:	/* 5.5 Mb/s */
747 	case 22:	/* 11  Mb/s */
748 	case 44:	/* 22  Mb/s */
749 		/* 5.5 - 11 Mb/s WLAN: send ACK/CTS at 2 Mb/s */
750 		ctsrate = 4;
751 		break;
752 	default:
753 		/* TBD */
754 		return -1;
755 	}
756 
757 	d->d_plcp_len = data_dur;
758 
759 	ack = (use_ack) ? pre + (IEEE80211_DUR_DS_SLOW_ACK * 2) / ctsrate : 0;
760 
761 	d->d_rts_dur =
762 	    pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate +
763 	    pre + data_dur +
764 	    ack;
765 
766 	d->d_data_dur = ack;
767 
768 	return 0;
769 }
770 
771 /*
772  * Arguments in:
773  *
774  * wh:      802.11 header
775  *
776  * paylen:  payload length (no FCS, no WEP header)
777  *
778  * rate:    MSDU speed, units 500kb/s
779  *
780  * fraglen: fragment length, set to maximum (or higher) for no
781  *          fragmentation
782  *
783  * flags:   IEEE80211_F_PRIVACY (hardware adds WEP),
784  *          IEEE80211_F_SHPREAMBLE (use short preamble),
785  *          IEEE80211_F_SHSLOT (use short slot length)
786  *
787  * Arguments out:
788  *
789  * d0: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
790  *     of first/only fragment
791  *
792  * dn: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
793  *     of last fragment
794  *
795  * ieee80211_compute_duration assumes crypto-encapsulation, if any,
796  * has already taken place.
797  */
798 int
799 ieee80211_compute_duration(const struct ieee80211_frame_min *wh,
800     const struct ieee80211_key *wk, int len,
801     uint32_t icflags, int fraglen, int rate, struct ieee80211_duration *d0,
802     struct ieee80211_duration *dn, int *npktp, int debug)
803 {
804 	int ack, rc;
805 	int cryptolen,	/* crypto overhead: header+trailer */
806 	    firstlen,	/* first fragment's payload + overhead length */
807 	    hdrlen,	/* header length w/o driver padding */
808 	    lastlen,	/* last fragment's payload length w/ overhead */
809 	    lastlen0,	/* last fragment's payload length w/o overhead */
810 	    npkt,	/* number of fragments */
811 	    overlen,	/* non-802.11 header overhead per fragment */
812 	    paylen;	/* payload length w/o overhead */
813 
814 	hdrlen = ieee80211_anyhdrsize((const void *)wh);
815 
816         /* Account for padding required by the driver. */
817 	if (icflags & IEEE80211_F_DATAPAD)
818 		paylen = len - roundup(hdrlen, sizeof(u_int32_t));
819 	else
820 		paylen = len - hdrlen;
821 
822 	overlen = IEEE80211_CRC_LEN;
823 
824 	if (wk != NULL) {
825 		cryptolen = wk->wk_cipher->ic_header +
826 		            wk->wk_cipher->ic_trailer;
827 		paylen -= cryptolen;
828 		overlen += cryptolen;
829 	}
830 
831 	npkt = paylen / fraglen;
832 	lastlen0 = paylen % fraglen;
833 
834 	if (npkt == 0)			/* no fragments */
835 		lastlen = paylen + overlen;
836 	else if (lastlen0 != 0) {	/* a short "tail" fragment */
837 		lastlen = lastlen0 + overlen;
838 		npkt++;
839 	} else				/* full-length "tail" fragment */
840 		lastlen = fraglen + overlen;
841 
842 	if (npktp != NULL)
843 		*npktp = npkt;
844 
845 	if (npkt > 1)
846 		firstlen = fraglen + overlen;
847 	else
848 		firstlen = paylen + overlen;
849 
850 	if (debug) {
851 		printf("%s: npkt %d firstlen %d lastlen0 %d lastlen %d "
852 		    "fraglen %d overlen %d len %d rate %d icflags %08x\n",
853 		    __func__, npkt, firstlen, lastlen0, lastlen, fraglen,
854 		    overlen, len, rate, icflags);
855 	}
856 
857 	ack = !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
858 	    (wh->i_fc[1] & IEEE80211_FC0_TYPE_MASK) != IEEE80211_FC0_TYPE_CTL;
859 
860 	rc = ieee80211_compute_duration1(firstlen + hdrlen,
861 	    ack, icflags, rate, d0);
862 	if (rc == -1)
863 		return rc;
864 
865 	if (npkt <= 1) {
866 		*dn = *d0;
867 		return 0;
868 	}
869 	return ieee80211_compute_duration1(lastlen + hdrlen, ack, icflags, rate,
870 	    dn);
871 }
872 
873 /*
874  * Fragment the frame according to the specified mtu.
875  * The size of the 802.11 header (w/o padding) is provided
876  * so we don't need to recalculate it.  We create a new
877  * mbuf for each fragment and chain it through m_nextpkt;
878  * we might be able to optimize this by reusing the original
879  * packet's mbufs but that is significantly more complicated.
880  */
881 static int
882 ieee80211_fragment(struct ieee80211com *ic, struct mbuf *m0,
883 	u_int hdrsize, u_int ciphdrsize, u_int mtu)
884 {
885 	struct ieee80211_frame *wh, *whf;
886 	struct mbuf *m, *prev, *next;
887 	u_int totalhdrsize, fragno, fragsize, off, remainder, payload;
888 
889 	IASSERT(m0->m_nextpkt == NULL, ("mbuf already chained?"));
890 	IASSERT(m0->m_pkthdr.len > mtu,
891 		("pktlen %u mtu %u", m0->m_pkthdr.len, mtu));
892 
893 	wh = mtod(m0, struct ieee80211_frame *);
894 	/* NB: mark the first frag; it will be propagated below */
895 	wh->i_fc[1] |= IEEE80211_FC1_MORE_FRAG;
896 	totalhdrsize = hdrsize + ciphdrsize;
897 	fragno = 1;
898 	off = mtu - ciphdrsize;
899 	remainder = m0->m_pkthdr.len - off;
900 	prev = m0;
901 	do {
902 		fragsize = totalhdrsize + remainder;
903 		if (fragsize > mtu)
904 			fragsize = mtu;
905 		IASSERT(fragsize < MCLBYTES,
906 			("fragment size %u too big!", fragsize));
907 		if (fragsize > MHLEN)
908 			m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
909 		else
910 			m = m_gethdr(M_DONTWAIT, MT_DATA);
911 		if (m == NULL)
912 			goto bad;
913 		/* leave room to prepend any cipher header */
914 		m_align(m, fragsize - ciphdrsize);
915 
916 		/*
917 		 * Form the header in the fragment.  Note that since
918 		 * we mark the first fragment with the MORE_FRAG bit
919 		 * it automatically is propagated to each fragment; we
920 		 * need only clear it on the last fragment (done below).
921 		 */
922 		whf = mtod(m, struct ieee80211_frame *);
923 		memcpy(whf, wh, hdrsize);
924 		*(u_int16_t *)&whf->i_seq[0] |= htole16(
925 			(fragno & IEEE80211_SEQ_FRAG_MASK) <<
926 				IEEE80211_SEQ_FRAG_SHIFT);
927 		fragno++;
928 
929 		payload = fragsize - totalhdrsize;
930 		/* NB: destination is known to be contiguous */
931 		m_copydata(m0, off, payload, mtod(m, u_int8_t *) + hdrsize);
932 		m->m_len = hdrsize + payload;
933 		m->m_pkthdr.len = hdrsize + payload;
934 		m->m_flags |= M_FRAG;
935 
936 		/* chain up the fragment */
937 		prev->m_nextpkt = m;
938 		prev = m;
939 
940 		/* deduct fragment just formed */
941 		remainder -= payload;
942 		off += payload;
943 	} while (remainder != 0);
944 	whf->i_fc[1] &= ~IEEE80211_FC1_MORE_FRAG;
945 
946 	/* strip first mbuf now that everything has been copied */
947 	m_adj(m0, -(m0->m_pkthdr.len - (mtu - ciphdrsize)));
948 	m0->m_flags |= M_FIRSTFRAG | M_FRAG;
949 
950 	ic->ic_stats.is_tx_fragframes++;
951 	ic->ic_stats.is_tx_frags += fragno-1;
952 
953 	return 1;
954 bad:
955 	/* reclaim fragments but leave original frame for caller to free */
956 	for (m = m0->m_nextpkt; m != NULL; m = next) {
957 		next = m->m_nextpkt;
958 		m->m_nextpkt = NULL;            /* XXX paranoid */
959 		m_freem(m);
960 	}
961 	m0->m_nextpkt = NULL;
962 	return 0;
963 }
964 
965 /*
966  * Add a supported rates element id to a frame.
967  */
968 static u_int8_t *
969 ieee80211_add_rates(u_int8_t *frm, const struct ieee80211_rateset *rs)
970 {
971 	int nrates;
972 
973 	*frm++ = IEEE80211_ELEMID_RATES;
974 	nrates = rs->rs_nrates;
975 	if (nrates > IEEE80211_RATE_SIZE)
976 		nrates = IEEE80211_RATE_SIZE;
977 	*frm++ = nrates;
978 	memcpy(frm, rs->rs_rates, nrates);
979 	return frm + nrates;
980 }
981 
982 /*
983  * Add an extended supported rates element id to a frame.
984  */
985 static u_int8_t *
986 ieee80211_add_xrates(u_int8_t *frm, const struct ieee80211_rateset *rs)
987 {
988 	/*
989 	 * Add an extended supported rates element if operating in 11g mode.
990 	 */
991 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
992 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
993 		*frm++ = IEEE80211_ELEMID_XRATES;
994 		*frm++ = nrates;
995 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
996 		frm += nrates;
997 	}
998 	return frm;
999 }
1000 
1001 /*
1002  * Add an ssid elemet to a frame.
1003  */
1004 static u_int8_t *
1005 ieee80211_add_ssid(u_int8_t *frm, const u_int8_t *ssid, u_int len)
1006 {
1007 	*frm++ = IEEE80211_ELEMID_SSID;
1008 	*frm++ = len;
1009 	memcpy(frm, ssid, len);
1010 	return frm + len;
1011 }
1012 
1013 /*
1014  * Add an erp element to a frame.
1015  */
1016 static u_int8_t *
1017 ieee80211_add_erp(u_int8_t *frm, struct ieee80211com *ic)
1018 {
1019 	u_int8_t erp;
1020 
1021 	*frm++ = IEEE80211_ELEMID_ERP;
1022 	*frm++ = 1;
1023 	erp = 0;
1024 	if (ic->ic_nonerpsta != 0)
1025 		erp |= IEEE80211_ERP_NON_ERP_PRESENT;
1026 	if (ic->ic_flags & IEEE80211_F_USEPROT)
1027 		erp |= IEEE80211_ERP_USE_PROTECTION;
1028 	if (ic->ic_flags & IEEE80211_F_USEBARKER)
1029 		erp |= IEEE80211_ERP_LONG_PREAMBLE;
1030 	*frm++ = erp;
1031 	return frm;
1032 }
1033 
1034 static u_int8_t *
1035 ieee80211_setup_wpa_ie(struct ieee80211com *ic, u_int8_t *ie)
1036 {
1037 #define	WPA_OUI_BYTES		0x00, 0x50, 0xf2
1038 #define	ADDSHORT(frm, v) do {			\
1039 	frm[0] = (v) & 0xff;			\
1040 	frm[1] = (v) >> 8;			\
1041 	frm += 2;				\
1042 } while (0)
1043 #define	ADDSELECTOR(frm, sel) do {		\
1044 	memcpy(frm, sel, 4);			\
1045 	frm += 4;				\
1046 } while (0)
1047 	static const u_int8_t oui[4] = { WPA_OUI_BYTES, WPA_OUI_TYPE };
1048 	static const u_int8_t cipher_suite[][4] = {
1049 		{ WPA_OUI_BYTES, WPA_CSE_WEP40 },	/* NB: 40-bit */
1050 		{ WPA_OUI_BYTES, WPA_CSE_TKIP },
1051 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX WRAP */
1052 		{ WPA_OUI_BYTES, WPA_CSE_CCMP },
1053 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1054 		{ WPA_OUI_BYTES, WPA_CSE_NULL },
1055 	};
1056 	static const u_int8_t wep104_suite[4] =
1057 		{ WPA_OUI_BYTES, WPA_CSE_WEP104 };
1058 	static const u_int8_t key_mgt_unspec[4] =
1059 		{ WPA_OUI_BYTES, WPA_ASE_8021X_UNSPEC };
1060 	static const u_int8_t key_mgt_psk[4] =
1061 		{ WPA_OUI_BYTES, WPA_ASE_8021X_PSK };
1062 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1063 	u_int8_t *frm = ie;
1064 	u_int8_t *selcnt;
1065 
1066 	*frm++ = IEEE80211_ELEMID_VENDOR;
1067 	*frm++ = 0;				/* length filled in below */
1068 	memcpy(frm, oui, sizeof(oui));		/* WPA OUI */
1069 	frm += sizeof(oui);
1070 	ADDSHORT(frm, WPA_VERSION);
1071 
1072 	/* XXX filter out CKIP */
1073 
1074 	/* multicast cipher */
1075 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1076 	    rsn->rsn_mcastkeylen >= 13)
1077 		ADDSELECTOR(frm, wep104_suite);
1078 	else
1079 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1080 
1081 	/* unicast cipher list */
1082 	selcnt = frm;
1083 	ADDSHORT(frm, 0);			/* selector count */
1084 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1085 		selcnt[0]++;
1086 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1087 	}
1088 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1089 		selcnt[0]++;
1090 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1091 	}
1092 
1093 	/* authenticator selector list */
1094 	selcnt = frm;
1095 	ADDSHORT(frm, 0);			/* selector count */
1096 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1097 		selcnt[0]++;
1098 		ADDSELECTOR(frm, key_mgt_unspec);
1099 	}
1100 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1101 		selcnt[0]++;
1102 		ADDSELECTOR(frm, key_mgt_psk);
1103 	}
1104 
1105 	/* optional capabilities */
1106 	if (rsn->rsn_caps != 0 && rsn->rsn_caps != RSN_CAP_PREAUTH)
1107 		ADDSHORT(frm, rsn->rsn_caps);
1108 
1109 	/* calculate element length */
1110 	ie[1] = frm - ie - 2;
1111 	IASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1112 		("WPA IE too big, %u > %zu",
1113 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1114 	return frm;
1115 #undef ADDSHORT
1116 #undef ADDSELECTOR
1117 #undef WPA_OUI_BYTES
1118 }
1119 
1120 static u_int8_t *
1121 ieee80211_setup_rsn_ie(struct ieee80211com *ic, u_int8_t *ie)
1122 {
1123 #define	RSN_OUI_BYTES		0x00, 0x0f, 0xac
1124 #define	ADDSHORT(frm, v) do {			\
1125 	frm[0] = (v) & 0xff;			\
1126 	frm[1] = (v) >> 8;			\
1127 	frm += 2;				\
1128 } while (0)
1129 #define	ADDSELECTOR(frm, sel) do {		\
1130 	memcpy(frm, sel, 4);			\
1131 	frm += 4;				\
1132 } while (0)
1133 	static const u_int8_t cipher_suite[][4] = {
1134 		{ RSN_OUI_BYTES, RSN_CSE_WEP40 },	/* NB: 40-bit */
1135 		{ RSN_OUI_BYTES, RSN_CSE_TKIP },
1136 		{ RSN_OUI_BYTES, RSN_CSE_WRAP },
1137 		{ RSN_OUI_BYTES, RSN_CSE_CCMP },
1138 		{ 0x00, 0x00, 0x00, 0x00 },		/* XXX CKIP */
1139 		{ RSN_OUI_BYTES, RSN_CSE_NULL },
1140 	};
1141 	static const u_int8_t wep104_suite[4] =
1142 		{ RSN_OUI_BYTES, RSN_CSE_WEP104 };
1143 	static const u_int8_t key_mgt_unspec[4] =
1144 		{ RSN_OUI_BYTES, RSN_ASE_8021X_UNSPEC };
1145 	static const u_int8_t key_mgt_psk[4] =
1146 		{ RSN_OUI_BYTES, RSN_ASE_8021X_PSK };
1147 	const struct ieee80211_rsnparms *rsn = &ic->ic_bss->ni_rsn;
1148 	u_int8_t *frm = ie;
1149 	u_int8_t *selcnt;
1150 
1151 	*frm++ = IEEE80211_ELEMID_RSN;
1152 	*frm++ = 0;				/* length filled in below */
1153 	ADDSHORT(frm, RSN_VERSION);
1154 
1155 	/* XXX filter out CKIP */
1156 
1157 	/* multicast cipher */
1158 	if (rsn->rsn_mcastcipher == IEEE80211_CIPHER_WEP &&
1159 	    rsn->rsn_mcastkeylen >= 13)
1160 		ADDSELECTOR(frm, wep104_suite);
1161 	else
1162 		ADDSELECTOR(frm, cipher_suite[rsn->rsn_mcastcipher]);
1163 
1164 	/* unicast cipher list */
1165 	selcnt = frm;
1166 	ADDSHORT(frm, 0);			/* selector count */
1167 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_AES_CCM)) {
1168 		selcnt[0]++;
1169 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_AES_CCM]);
1170 	}
1171 	if (rsn->rsn_ucastcipherset & (1<<IEEE80211_CIPHER_TKIP)) {
1172 		selcnt[0]++;
1173 		ADDSELECTOR(frm, cipher_suite[IEEE80211_CIPHER_TKIP]);
1174 	}
1175 
1176 	/* authenticator selector list */
1177 	selcnt = frm;
1178 	ADDSHORT(frm, 0);			/* selector count */
1179 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_UNSPEC) {
1180 		selcnt[0]++;
1181 		ADDSELECTOR(frm, key_mgt_unspec);
1182 	}
1183 	if (rsn->rsn_keymgmtset & WPA_ASE_8021X_PSK) {
1184 		selcnt[0]++;
1185 		ADDSELECTOR(frm, key_mgt_psk);
1186 	}
1187 
1188 	/* optional capabilities */
1189 	ADDSHORT(frm, rsn->rsn_caps);
1190 	/* XXX PMKID */
1191 
1192 	/* calculate element length */
1193 	ie[1] = frm - ie - 2;
1194 	IASSERT(ie[1]+2 <= sizeof(struct ieee80211_ie_wpa),
1195 		("RSN IE too big, %u > %zu",
1196 		ie[1]+2, sizeof(struct ieee80211_ie_wpa)));
1197 	return frm;
1198 #undef ADDSELECTOR
1199 #undef ADDSHORT
1200 #undef RSN_OUI_BYTES
1201 }
1202 
1203 /*
1204  * Add a WPA/RSN element to a frame.
1205  */
1206 static u_int8_t *
1207 ieee80211_add_wpa(u_int8_t *frm, struct ieee80211com *ic)
1208 {
1209 
1210 	IASSERT(ic->ic_flags & IEEE80211_F_WPA, ("no WPA/RSN!"));
1211 	if (ic->ic_flags & IEEE80211_F_WPA2)
1212 		frm = ieee80211_setup_rsn_ie(ic, frm);
1213 	if (ic->ic_flags & IEEE80211_F_WPA1)
1214 		frm = ieee80211_setup_wpa_ie(ic, frm);
1215 	return frm;
1216 }
1217 
1218 #define	WME_OUI_BYTES		0x00, 0x50, 0xf2
1219 /*
1220  * Add a WME information element to a frame.
1221  */
1222 static u_int8_t *
1223 ieee80211_add_wme_info(u_int8_t *frm, struct ieee80211_wme_state *wme)
1224 {
1225 	static const struct ieee80211_wme_info info = {
1226 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1227 		.wme_len	= sizeof(struct ieee80211_wme_info) - 2,
1228 		.wme_oui	= { WME_OUI_BYTES },
1229 		.wme_type	= WME_OUI_TYPE,
1230 		.wme_subtype	= WME_INFO_OUI_SUBTYPE,
1231 		.wme_version	= WME_VERSION,
1232 		.wme_info	= 0,
1233 	};
1234 	memcpy(frm, &info, sizeof(info));
1235 	return frm + sizeof(info);
1236 }
1237 
1238 /*
1239  * Add a WME parameters element to a frame.
1240  */
1241 static u_int8_t *
1242 ieee80211_add_wme_param(u_int8_t *frm, struct ieee80211_wme_state *wme)
1243 {
1244 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
1245 #define	ADDSHORT(frm, v) do {			\
1246 	frm[0] = (v) & 0xff;			\
1247 	frm[1] = (v) >> 8;			\
1248 	frm += 2;				\
1249 } while (0)
1250 	/* NB: this works 'cuz a param has an info at the front */
1251 	static const struct ieee80211_wme_info param = {
1252 		.wme_id		= IEEE80211_ELEMID_VENDOR,
1253 		.wme_len	= sizeof(struct ieee80211_wme_param) - 2,
1254 		.wme_oui	= { WME_OUI_BYTES },
1255 		.wme_type	= WME_OUI_TYPE,
1256 		.wme_subtype	= WME_PARAM_OUI_SUBTYPE,
1257 		.wme_version	= WME_VERSION,
1258 	};
1259 	int i;
1260 
1261 	memcpy(frm, &param, sizeof(param));
1262 	frm += __offsetof(struct ieee80211_wme_info, wme_info);
1263 	*frm++ = wme->wme_bssChanParams.cap_info;	/* AC info */
1264 	*frm++ = 0;					/* reserved field */
1265 	for (i = 0; i < WME_NUM_AC; i++) {
1266 		const struct wmeParams *ac =
1267 		       &wme->wme_bssChanParams.cap_wmeParams[i];
1268 		*frm++ = SM(i, WME_PARAM_ACI)
1269 		       | SM(ac->wmep_acm, WME_PARAM_ACM)
1270 		       | SM(ac->wmep_aifsn, WME_PARAM_AIFSN)
1271 		       ;
1272 		*frm++ = SM(ac->wmep_logcwmax, WME_PARAM_LOGCWMAX)
1273 		       | SM(ac->wmep_logcwmin, WME_PARAM_LOGCWMIN)
1274 		       ;
1275 		ADDSHORT(frm, ac->wmep_txopLimit);
1276 	}
1277 	return frm;
1278 #undef SM
1279 #undef ADDSHORT
1280 }
1281 #undef WME_OUI_BYTES
1282 
1283 /*
1284  * Send a probe request frame with the specified ssid
1285  * and any optional information element data.
1286  */
1287 int
1288 ieee80211_send_probereq(struct ieee80211_node *ni,
1289 	const u_int8_t sa[IEEE80211_ADDR_LEN],
1290 	const u_int8_t da[IEEE80211_ADDR_LEN],
1291 	const u_int8_t bssid[IEEE80211_ADDR_LEN],
1292 	const u_int8_t *ssid, size_t ssidlen,
1293 	const void *optie, size_t optielen)
1294 {
1295 	struct ieee80211com *ic = ni->ni_ic;
1296 	enum ieee80211_phymode mode;
1297 	struct ieee80211_frame *wh;
1298 	struct mbuf *m;
1299 	u_int8_t *frm;
1300 
1301 	/*
1302 	 * Hold a reference on the node so it doesn't go away until after
1303 	 * the xmit is complete all the way in the driver.  On error we
1304 	 * will remove our reference.
1305 	 */
1306 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1307 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1308 		__func__, __LINE__,
1309 		ni, ether_sprintf(ni->ni_macaddr),
1310 		ieee80211_node_refcnt(ni)+1);
1311 	ieee80211_ref_node(ni);
1312 
1313 	/*
1314 	 * prreq frame format
1315 	 *	[tlv] ssid
1316 	 *	[tlv] supported rates
1317 	 *	[tlv] extended supported rates
1318 	 *	[tlv] user-specified ie's
1319 	 */
1320 	m = ieee80211_getmgtframe(&frm,
1321 		 2 + IEEE80211_NWID_LEN
1322 	       + 2 + IEEE80211_RATE_SIZE
1323 	       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1324 	       + (optie != NULL ? optielen : 0)
1325 	);
1326 	if (m == NULL) {
1327 		ic->ic_stats.is_tx_nobuf++;
1328 		ieee80211_free_node(ni);
1329 		return ENOMEM;
1330 	}
1331 
1332 	frm = ieee80211_add_ssid(frm, ssid, ssidlen);
1333 	mode = ieee80211_chan2mode(ic, ic->ic_curchan);
1334 	frm = ieee80211_add_rates(frm, &ic->ic_sup_rates[mode]);
1335 	frm = ieee80211_add_xrates(frm, &ic->ic_sup_rates[mode]);
1336 
1337 	if (optie != NULL) {
1338 		memcpy(frm, optie, optielen);
1339 		frm += optielen;
1340 	}
1341 	m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1342 
1343 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1344 	if (m == NULL)
1345 		return ENOMEM;
1346 	IASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
1347 	m->m_pkthdr.rcvif = (void *)ni;
1348 
1349 	wh = mtod(m, struct ieee80211_frame *);
1350 	ieee80211_send_setup(ic, ni, wh,
1351 		IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_PROBE_REQ,
1352 		sa, da, bssid);
1353 	/* XXX power management? */
1354 
1355 	IEEE80211_NODE_STAT(ni, tx_probereq);
1356 	IEEE80211_NODE_STAT(ni, tx_mgmt);
1357 
1358 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
1359 	    "[%s] send probe req on channel %u\n",
1360 	    ether_sprintf(wh->i_addr1),
1361 	    ieee80211_chan2ieee(ic, ic->ic_curchan));
1362 
1363 	IF_ENQUEUE(&ic->ic_mgtq, m);
1364 	(*ic->ic_ifp->if_start)(ic->ic_ifp);
1365 	return 0;
1366 }
1367 
1368 /*
1369  * Send a management frame.  The node is for the destination (or ic_bss
1370  * when in station mode).  Nodes other than ic_bss have their reference
1371  * count bumped to reflect our use for an indeterminant time.
1372  */
1373 int
1374 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
1375 	int type, int arg)
1376 {
1377 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
1378 	struct mbuf *m;
1379 	u_int8_t *frm;
1380 	u_int16_t capinfo;
1381 	int has_challenge, is_shared_key, ret, timer, status;
1382 
1383 	IASSERT(ni != NULL, ("null node"));
1384 
1385 	/*
1386 	 * Hold a reference on the node so it doesn't go away until after
1387 	 * the xmit is complete all the way in the driver.  On error we
1388 	 * will remove our reference.
1389 	 */
1390 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1391 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1392 		__func__, __LINE__,
1393 		ni, ether_sprintf(ni->ni_macaddr),
1394 		ieee80211_node_refcnt(ni)+1);
1395 	ieee80211_ref_node(ni);
1396 
1397 	timer = 0;
1398 	switch (type) {
1399 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
1400 		/*
1401 		 * probe response frame format
1402 		 *	[8] time stamp
1403 		 *	[2] beacon interval
1404 		 *	[2] cabability information
1405 		 *	[tlv] ssid
1406 		 *	[tlv] supported rates
1407 		 *	[tlv] parameter set (FH/DS)
1408 		 *	[tlv] parameter set (IBSS)
1409 		 *	[tlv] extended rate phy (ERP)
1410 		 *	[tlv] extended supported rates
1411 		 *	[tlv] WPA
1412 		 *	[tlv] WME (optional)
1413 		 */
1414 		m = ieee80211_getmgtframe(&frm,
1415 			 8
1416 		       + sizeof(u_int16_t)
1417 		       + sizeof(u_int16_t)
1418 		       + 2 + IEEE80211_NWID_LEN
1419 		       + 2 + IEEE80211_RATE_SIZE
1420 		       + 7	/* max(7,3) */
1421 		       + 6
1422 		       + 3
1423 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1424 		       /* XXX !WPA1+WPA2 fits w/o a cluster */
1425 		       + (ic->ic_flags & IEEE80211_F_WPA ?
1426 				2*sizeof(struct ieee80211_ie_wpa) : 0)
1427 		       + sizeof(struct ieee80211_wme_param)
1428 		);
1429 		if (m == NULL)
1430 			senderr(ENOMEM, is_tx_nobuf);
1431 
1432 		memset(frm, 0, 8);	/* timestamp should be filled later */
1433 		frm += 8;
1434 		*(u_int16_t *)frm = htole16(ic->ic_bss->ni_intval);
1435 		frm += 2;
1436 		if (ic->ic_opmode == IEEE80211_M_IBSS)
1437 			capinfo = IEEE80211_CAPINFO_IBSS;
1438 		else
1439 			capinfo = IEEE80211_CAPINFO_ESS;
1440 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1441 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1442 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1443 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1444 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1445 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
1446 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1447 		*(u_int16_t *)frm = htole16(capinfo);
1448 		frm += 2;
1449 
1450 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
1451 				ic->ic_bss->ni_esslen);
1452 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1453 
1454 		if (ic->ic_phytype == IEEE80211_T_FH) {
1455                         *frm++ = IEEE80211_ELEMID_FHPARMS;
1456                         *frm++ = 5;
1457                         *frm++ = ni->ni_fhdwell & 0x00ff;
1458                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
1459                         *frm++ = IEEE80211_FH_CHANSET(
1460 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1461                         *frm++ = IEEE80211_FH_CHANPAT(
1462 			    ieee80211_chan2ieee(ic, ic->ic_curchan));
1463                         *frm++ = ni->ni_fhindex;
1464 		} else {
1465 			*frm++ = IEEE80211_ELEMID_DSPARMS;
1466 			*frm++ = 1;
1467 			*frm++ = ieee80211_chan2ieee(ic, ic->ic_curchan);
1468 		}
1469 
1470 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
1471 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1472 			*frm++ = 2;
1473 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1474 		}
1475 		if (ic->ic_flags & IEEE80211_F_WPA)
1476 			frm = ieee80211_add_wpa(frm, ic);
1477 		if (ic->ic_curmode == IEEE80211_MODE_11G)
1478 			frm = ieee80211_add_erp(frm, ic);
1479 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1480 		if (ic->ic_flags & IEEE80211_F_WME)
1481 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1482 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1483 		break;
1484 
1485 	case IEEE80211_FC0_SUBTYPE_AUTH:
1486 		status = arg >> 16;
1487 		arg &= 0xffff;
1488 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
1489 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
1490 		    ni->ni_challenge != NULL);
1491 
1492 		/*
1493 		 * Deduce whether we're doing open authentication or
1494 		 * shared key authentication.  We do the latter if
1495 		 * we're in the middle of a shared key authentication
1496 		 * handshake or if we're initiating an authentication
1497 		 * request and configured to use shared key.
1498 		 */
1499 		is_shared_key = has_challenge ||
1500 		     arg >= IEEE80211_AUTH_SHARED_RESPONSE ||
1501 		     (arg == IEEE80211_AUTH_SHARED_REQUEST &&
1502 		      ic->ic_bss->ni_authmode == IEEE80211_AUTH_SHARED);
1503 
1504 		m = ieee80211_getmgtframe(&frm,
1505 			  3 * sizeof(u_int16_t)
1506 			+ (has_challenge && status == IEEE80211_STATUS_SUCCESS ?
1507 				sizeof(u_int16_t)+IEEE80211_CHALLENGE_LEN : 0)
1508 		);
1509 		if (m == NULL)
1510 			senderr(ENOMEM, is_tx_nobuf);
1511 
1512 		((u_int16_t *)frm)[0] =
1513 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
1514 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
1515 		((u_int16_t *)frm)[1] = htole16(arg);	/* sequence number */
1516 		((u_int16_t *)frm)[2] = htole16(status);/* status */
1517 
1518 		if (has_challenge && status == IEEE80211_STATUS_SUCCESS) {
1519 			((u_int16_t *)frm)[3] =
1520 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
1521 			    IEEE80211_ELEMID_CHALLENGE);
1522 			memcpy(&((u_int16_t *)frm)[4], ni->ni_challenge,
1523 			    IEEE80211_CHALLENGE_LEN);
1524 			m->m_pkthdr.len = m->m_len =
1525 				4 * sizeof(u_int16_t) + IEEE80211_CHALLENGE_LEN;
1526 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
1527 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1528 				    "[%s] request encrypt frame (%s)\n",
1529 				    ether_sprintf(ni->ni_macaddr), __func__);
1530 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
1531 			}
1532 		} else
1533 			m->m_pkthdr.len = m->m_len = 3 * sizeof(u_int16_t);
1534 
1535 		/* XXX not right for shared key */
1536 		if (status == IEEE80211_STATUS_SUCCESS)
1537 			IEEE80211_NODE_STAT(ni, tx_auth);
1538 		else
1539 			IEEE80211_NODE_STAT(ni, tx_auth_fail);
1540 
1541 		if (ic->ic_opmode == IEEE80211_M_STA)
1542 			timer = IEEE80211_TRANS_WAIT;
1543 		break;
1544 
1545 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
1546 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
1547 			"[%s] send station deauthenticate (reason %d)\n",
1548 			ether_sprintf(ni->ni_macaddr), arg);
1549 		m = ieee80211_getmgtframe(&frm, sizeof(u_int16_t));
1550 		if (m == NULL)
1551 			senderr(ENOMEM, is_tx_nobuf);
1552 		*(u_int16_t *)frm = htole16(arg);	/* reason */
1553 		m->m_pkthdr.len = m->m_len = sizeof(u_int16_t);
1554 
1555 		IEEE80211_NODE_STAT(ni, tx_deauth);
1556 		IEEE80211_NODE_STAT_SET(ni, tx_deauth_code, arg);
1557 
1558 		ieee80211_node_unauthorize(ni);		/* port closed */
1559 		break;
1560 
1561 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
1562 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
1563 		/*
1564 		 * asreq frame format
1565 		 *	[2] capability information
1566 		 *	[2] listen interval
1567 		 *	[6*] current AP address (reassoc only)
1568 		 *	[tlv] ssid
1569 		 *	[tlv] supported rates
1570 		 *	[tlv] extended supported rates
1571 		 *	[tlv] WME
1572 		 *	[tlv] user-specified ie's
1573 		 */
1574 		m = ieee80211_getmgtframe(&frm,
1575 			 sizeof(u_int16_t)
1576 		       + sizeof(u_int16_t)
1577 		       + IEEE80211_ADDR_LEN
1578 		       + 2 + IEEE80211_NWID_LEN
1579 		       + 2 + IEEE80211_RATE_SIZE
1580 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1581 		       + sizeof(struct ieee80211_wme_info)
1582 		       + (ic->ic_opt_ie != NULL ? ic->ic_opt_ie_len : 0)
1583 		);
1584 		if (m == NULL)
1585 			senderr(ENOMEM, is_tx_nobuf);
1586 
1587 		capinfo = 0;
1588 		if (ic->ic_opmode == IEEE80211_M_IBSS)
1589 			capinfo |= IEEE80211_CAPINFO_IBSS;
1590 		else		/* IEEE80211_M_STA */
1591 			capinfo |= IEEE80211_CAPINFO_ESS;
1592 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1593 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1594 		/*
1595 		 * NB: Some 11a AP's reject the request when
1596 		 *     short premable is set.
1597 		 */
1598 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1599 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1600 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1601 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) &&
1602 		    (ic->ic_caps & IEEE80211_C_SHSLOT))
1603 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1604 		*(u_int16_t *)frm = htole16(capinfo);
1605 		frm += 2;
1606 
1607 		*(u_int16_t *)frm = htole16(ic->ic_lintval);
1608 		frm += 2;
1609 
1610 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
1611 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
1612 			frm += IEEE80211_ADDR_LEN;
1613 		}
1614 
1615 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
1616 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1617 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1618 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1619 			frm = ieee80211_add_wme_info(frm, &ic->ic_wme);
1620 		if (ic->ic_opt_ie != NULL) {
1621 			memcpy(frm, ic->ic_opt_ie, ic->ic_opt_ie_len);
1622 			frm += ic->ic_opt_ie_len;
1623 		}
1624 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1625 
1626 		timer = IEEE80211_TRANS_WAIT;
1627 		break;
1628 
1629 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
1630 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
1631 		/*
1632 		 * asreq frame format
1633 		 *	[2] capability information
1634 		 *	[2] status
1635 		 *	[2] association ID
1636 		 *	[tlv] supported rates
1637 		 *	[tlv] extended supported rates
1638 		 *	[tlv] WME (if enabled and STA enabled)
1639 		 */
1640 		m = ieee80211_getmgtframe(&frm,
1641 			 sizeof(u_int16_t)
1642 		       + sizeof(u_int16_t)
1643 		       + sizeof(u_int16_t)
1644 		       + 2 + IEEE80211_RATE_SIZE
1645 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1646 		       + sizeof(struct ieee80211_wme_param)
1647 		);
1648 		if (m == NULL)
1649 			senderr(ENOMEM, is_tx_nobuf);
1650 
1651 		capinfo = IEEE80211_CAPINFO_ESS;
1652 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
1653 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
1654 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1655 		    IEEE80211_IS_CHAN_2GHZ(ic->ic_curchan))
1656 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1657 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
1658 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1659 		*(u_int16_t *)frm = htole16(capinfo);
1660 		frm += 2;
1661 
1662 		*(u_int16_t *)frm = htole16(arg);	/* status */
1663 		frm += 2;
1664 
1665 		if (arg == IEEE80211_STATUS_SUCCESS) {
1666 			*(u_int16_t *)frm = htole16(ni->ni_associd);
1667 			IEEE80211_NODE_STAT(ni, tx_assoc);
1668 		} else
1669 			IEEE80211_NODE_STAT(ni, tx_assoc_fail);
1670 		frm += 2;
1671 
1672 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
1673 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
1674 		if ((ic->ic_flags & IEEE80211_F_WME) && ni->ni_wme_ie != NULL)
1675 			frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1676 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
1677 		break;
1678 
1679 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
1680 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1681 			"[%s] send station disassociate (reason %d)\n",
1682 			ether_sprintf(ni->ni_macaddr), arg);
1683 		m = ieee80211_getmgtframe(&frm, sizeof(u_int16_t));
1684 		if (m == NULL)
1685 			senderr(ENOMEM, is_tx_nobuf);
1686 		*(u_int16_t *)frm = htole16(arg);	/* reason */
1687 		m->m_pkthdr.len = m->m_len = sizeof(u_int16_t);
1688 
1689 		IEEE80211_NODE_STAT(ni, tx_disassoc);
1690 		IEEE80211_NODE_STAT_SET(ni, tx_disassoc_code, arg);
1691 		break;
1692 
1693 	default:
1694 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1695 			"[%s] invalid mgmt frame type %u\n",
1696 			ether_sprintf(ni->ni_macaddr), type);
1697 		senderr(EINVAL, is_tx_unknownmgt);
1698 		/* NOTREACHED */
1699 	}
1700 	ret = ieee80211_mgmt_output(ic, ni, m, type, timer);
1701 	if (ret != 0) {
1702 bad:
1703 		ieee80211_free_node(ni);
1704 	}
1705 	return ret;
1706 #undef senderr
1707 }
1708 
1709 /*
1710  * Allocate a beacon frame and fillin the appropriate bits.
1711  */
1712 struct mbuf *
1713 ieee80211_beacon_alloc(struct ieee80211com *ic, struct ieee80211_node *ni,
1714 	struct ieee80211_beacon_offsets *bo)
1715 {
1716 	struct ifnet *ifp = ic->ic_ifp;
1717 	struct ieee80211_frame *wh;
1718 	struct mbuf *m;
1719 	int pktlen;
1720 	u_int8_t *frm, *efrm;
1721 	u_int16_t capinfo;
1722 	struct ieee80211_rateset *rs;
1723 
1724 	/*
1725 	 * beacon frame format
1726 	 *	[8] time stamp
1727 	 *	[2] beacon interval
1728 	 *	[2] cabability information
1729 	 *	[tlv] ssid
1730 	 *	[tlv] supported rates
1731 	 *	[3] parameter set (DS)
1732 	 *	[tlv] parameter set (IBSS/TIM)
1733 	 *	[tlv] extended rate phy (ERP)
1734 	 *	[tlv] extended supported rates
1735 	 *	[tlv] WME parameters
1736 	 *	[tlv] WPA/RSN parameters
1737 	 * XXX Vendor-specific OIDs (e.g. Atheros)
1738 	 * NB: we allocate the max space required for the TIM bitmap.
1739 	 */
1740 	rs = &ni->ni_rates;
1741 	pktlen =   8					/* time stamp */
1742 		 + sizeof(u_int16_t)			/* beacon interval */
1743 		 + sizeof(u_int16_t)			/* capabilities */
1744 		 + 2 + ni->ni_esslen			/* ssid */
1745 	         + 2 + IEEE80211_RATE_SIZE		/* supported rates */
1746 	         + 2 + 1				/* DS parameters */
1747 		 + 2 + 4 + ic->ic_tim_len		/* DTIM/IBSSPARMS */
1748 		 + 2 + 1				/* ERP */
1749 	         + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)
1750 		 + (ic->ic_caps & IEEE80211_C_WME ?	/* WME */
1751 			sizeof(struct ieee80211_wme_param) : 0)
1752 		 + (ic->ic_caps & IEEE80211_C_WPA ?	/* WPA 1+2 */
1753 			2*sizeof(struct ieee80211_ie_wpa) : 0)
1754 		 ;
1755 	m = ieee80211_getmgtframe(&frm, pktlen);
1756 	if (m == NULL) {
1757 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
1758 			"%s: cannot get buf; size %u\n", __func__, pktlen);
1759 		ic->ic_stats.is_tx_nobuf++;
1760 		return NULL;
1761 	}
1762 
1763 	memset(frm, 0, 8);	/* XXX timestamp is set by hardware/driver */
1764 	frm += 8;
1765 	*(u_int16_t *)frm = htole16(ni->ni_intval);
1766 	frm += 2;
1767 	if (ic->ic_opmode == IEEE80211_M_IBSS)
1768 		capinfo = IEEE80211_CAPINFO_IBSS;
1769 	else
1770 		capinfo = IEEE80211_CAPINFO_ESS;
1771 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1772 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1773 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1774 	    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
1775 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1776 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1777 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1778 	bo->bo_caps = (u_int16_t *)frm;
1779 	*(u_int16_t *)frm = htole16(capinfo);
1780 	frm += 2;
1781 	*frm++ = IEEE80211_ELEMID_SSID;
1782 	if ((ic->ic_flags & IEEE80211_F_HIDESSID) == 0) {
1783 		*frm++ = ni->ni_esslen;
1784 		memcpy(frm, ni->ni_essid, ni->ni_esslen);
1785 		frm += ni->ni_esslen;
1786 	} else
1787 		*frm++ = 0;
1788 	frm = ieee80211_add_rates(frm, rs);
1789 	if (ic->ic_curmode != IEEE80211_MODE_FH) {
1790 		*frm++ = IEEE80211_ELEMID_DSPARMS;
1791 		*frm++ = 1;
1792 		*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
1793 	}
1794 	bo->bo_tim = frm;
1795 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
1796 		*frm++ = IEEE80211_ELEMID_IBSSPARMS;
1797 		*frm++ = 2;
1798 		*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
1799 		bo->bo_tim_len = 0;
1800 	} else {
1801 		struct ieee80211_tim_ie *tie = (struct ieee80211_tim_ie *) frm;
1802 
1803 		tie->tim_ie = IEEE80211_ELEMID_TIM;
1804 		tie->tim_len = 4;	/* length */
1805 		tie->tim_count = 0;	/* DTIM count */
1806 		tie->tim_period = ic->ic_dtim_period;	/* DTIM period */
1807 		tie->tim_bitctl = 0;	/* bitmap control */
1808 		tie->tim_bitmap[0] = 0;	/* Partial Virtual Bitmap */
1809 		frm += sizeof(struct ieee80211_tim_ie);
1810 		bo->bo_tim_len = 1;
1811 	}
1812 	bo->bo_trailer = frm;
1813 	if (ic->ic_flags & IEEE80211_F_WME) {
1814 		bo->bo_wme = frm;
1815 		frm = ieee80211_add_wme_param(frm, &ic->ic_wme);
1816 		ic->ic_flags &= ~IEEE80211_F_WMEUPDATE;
1817 	}
1818 	if (ic->ic_flags & IEEE80211_F_WPA)
1819 		frm = ieee80211_add_wpa(frm, ic);
1820 	if (ic->ic_curmode == IEEE80211_MODE_11G)
1821 		frm = ieee80211_add_erp(frm, ic);
1822 	efrm = ieee80211_add_xrates(frm, rs);
1823 	bo->bo_trailer_len = efrm - bo->bo_trailer;
1824 	m->m_pkthdr.len = m->m_len = efrm - mtod(m, u_int8_t *);
1825 
1826 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
1827 	IASSERT(m != NULL, ("no space for 802.11 header?"));
1828 	wh = mtod(m, struct ieee80211_frame *);
1829 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT |
1830 	    IEEE80211_FC0_SUBTYPE_BEACON;
1831 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
1832 	*(u_int16_t *)wh->i_dur = 0;
1833 	IEEE80211_ADDR_COPY(wh->i_addr1, ifp->if_broadcastaddr);
1834 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
1835 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
1836 	*(u_int16_t *)wh->i_seq = 0;
1837 
1838 	return m;
1839 }
1840 
1841 /*
1842  * Update the dynamic parts of a beacon frame based on the current state.
1843  */
1844 int
1845 ieee80211_beacon_update(struct ieee80211com *ic, struct ieee80211_node *ni,
1846     struct ieee80211_beacon_offsets *bo, struct mbuf *m, int mcast)
1847 {
1848 	int len_changed = 0;
1849 	u_int16_t capinfo;
1850 
1851 	IEEE80211_BEACON_LOCK(ic);
1852 	/* XXX faster to recalculate entirely or just changes? */
1853 	if (ic->ic_opmode == IEEE80211_M_IBSS)
1854 		capinfo = IEEE80211_CAPINFO_IBSS;
1855 	else
1856 		capinfo = IEEE80211_CAPINFO_ESS;
1857 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
1858 		capinfo |= IEEE80211_CAPINFO_PRIVACY;
1859 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
1860 	    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
1861 		capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
1862 	if (ic->ic_flags & IEEE80211_F_SHSLOT)
1863 		capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
1864 	*bo->bo_caps = htole16(capinfo);
1865 
1866 	if (ic->ic_flags & IEEE80211_F_WME) {
1867 		struct ieee80211_wme_state *wme = &ic->ic_wme;
1868 
1869 		/*
1870 		 * Check for agressive mode change.  When there is
1871 		 * significant high priority traffic in the BSS
1872 		 * throttle back BE traffic by using conservative
1873 		 * parameters.  Otherwise BE uses agressive params
1874 		 * to optimize performance of legacy/non-QoS traffic.
1875 		 */
1876 		if (wme->wme_flags & WME_F_AGGRMODE) {
1877 			if (wme->wme_hipri_traffic >
1878 			    wme->wme_hipri_switch_thresh) {
1879 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
1880 				    "%s: traffic %u, disable aggressive mode\n",
1881 				    __func__, wme->wme_hipri_traffic);
1882 				wme->wme_flags &= ~WME_F_AGGRMODE;
1883 				ieee80211_wme_updateparams_locked(ic);
1884 				wme->wme_hipri_traffic =
1885 					wme->wme_hipri_switch_hysteresis;
1886 			} else
1887 				wme->wme_hipri_traffic = 0;
1888 		} else {
1889 			if (wme->wme_hipri_traffic <=
1890 			    wme->wme_hipri_switch_thresh) {
1891 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_WME,
1892 				    "%s: traffic %u, enable aggressive mode\n",
1893 				    __func__, wme->wme_hipri_traffic);
1894 				wme->wme_flags |= WME_F_AGGRMODE;
1895 				ieee80211_wme_updateparams_locked(ic);
1896 				wme->wme_hipri_traffic = 0;
1897 			} else
1898 				wme->wme_hipri_traffic =
1899 					wme->wme_hipri_switch_hysteresis;
1900 		}
1901 		if (ic->ic_flags & IEEE80211_F_WMEUPDATE) {
1902 			(void) ieee80211_add_wme_param(bo->bo_wme, wme);
1903 			ic->ic_flags &= ~IEEE80211_F_WMEUPDATE;
1904 		}
1905 	}
1906 
1907 #ifndef IEEE80211_NO_HOSTAP
1908 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {	/* NB: no IBSS support*/
1909 		struct ieee80211_tim_ie *tie =
1910 			(struct ieee80211_tim_ie *) bo->bo_tim;
1911 		if (ic->ic_flags & IEEE80211_F_TIMUPDATE) {
1912 			u_int timlen, timoff, i;
1913 			/*
1914 			 * ATIM/DTIM needs updating.  If it fits in the
1915 			 * current space allocated then just copy in the
1916 			 * new bits.  Otherwise we need to move any trailing
1917 			 * data to make room.  Note that we know there is
1918 			 * contiguous space because ieee80211_beacon_allocate
1919 			 * insures there is space in the mbuf to write a
1920 			 * maximal-size virtual bitmap (based on ic_max_aid).
1921 			 */
1922 			/*
1923 			 * Calculate the bitmap size and offset, copy any
1924 			 * trailer out of the way, and then copy in the
1925 			 * new bitmap and update the information element.
1926 			 * Note that the tim bitmap must contain at least
1927 			 * one byte and any offset must be even.
1928 			 */
1929 			if (ic->ic_ps_pending != 0) {
1930 				timoff = 128;		/* impossibly large */
1931 				for (i = 0; i < ic->ic_tim_len; i++)
1932 					if (ic->ic_tim_bitmap[i]) {
1933 						timoff = i &~ 1;
1934 						break;
1935 					}
1936 				IASSERT(timoff != 128, ("tim bitmap empty!"));
1937 				for (i = ic->ic_tim_len-1; i >= timoff; i--)
1938 					if (ic->ic_tim_bitmap[i])
1939 						break;
1940 				timlen = 1 + (i - timoff);
1941 			} else {
1942 				timoff = 0;
1943 				timlen = 1;
1944 			}
1945 			if (timlen != bo->bo_tim_len) {
1946 				/* copy up/down trailer */
1947 				ovbcopy(bo->bo_trailer, tie->tim_bitmap+timlen,
1948 					bo->bo_trailer_len);
1949 				bo->bo_trailer = tie->tim_bitmap+timlen;
1950 				bo->bo_wme = bo->bo_trailer;
1951 				bo->bo_tim_len = timlen;
1952 
1953 				/* update information element */
1954 				tie->tim_len = 3 + timlen;
1955 				tie->tim_bitctl = timoff;
1956 				len_changed = 1;
1957 			}
1958 			memcpy(tie->tim_bitmap, ic->ic_tim_bitmap + timoff,
1959 				bo->bo_tim_len);
1960 
1961 			ic->ic_flags &= ~IEEE80211_F_TIMUPDATE;
1962 
1963 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
1964 				"%s: TIM updated, pending %u, off %u, len %u\n",
1965 				__func__, ic->ic_ps_pending, timoff, timlen);
1966 		}
1967 		/* count down DTIM period */
1968 		if (tie->tim_count == 0)
1969 			tie->tim_count = tie->tim_period - 1;
1970 		else
1971 			tie->tim_count--;
1972 		/* update state for buffered multicast frames on DTIM */
1973 		if (mcast && (tie->tim_count == 1 || tie->tim_period == 1))
1974 			tie->tim_bitctl |= 1;
1975 		else
1976 			tie->tim_bitctl &= ~1;
1977 	}
1978 #endif /* !IEEE80211_NO_HOSTAP */
1979 	IEEE80211_BEACON_UNLOCK(ic);
1980 
1981 	return len_changed;
1982 }
1983 
1984 /*
1985  * Save an outbound packet for a node in power-save sleep state.
1986  * The new packet is placed on the node's saved queue, and the TIM
1987  * is changed, if necessary.
1988  */
1989 void
1990 ieee80211_pwrsave(struct ieee80211com *ic, struct ieee80211_node *ni,
1991 		  struct mbuf *m)
1992 {
1993 	int qlen, age;
1994 
1995 	IEEE80211_NODE_SAVEQ_LOCK(ni);
1996 	if (IF_QFULL(&ni->ni_savedq)) {
1997 		IF_DROP(&ni->ni_savedq);
1998 		IEEE80211_NODE_SAVEQ_UNLOCK(ni);
1999 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
2000 			"[%s] pwr save q overflow, drops %d (size %d)\n",
2001 			ether_sprintf(ni->ni_macaddr),
2002 			ni->ni_savedq.ifq_drops, IEEE80211_PS_MAX_QUEUE);
2003 #ifdef IEEE80211_DEBUG
2004 		if (ieee80211_msg_dumppkts(ic))
2005 			ieee80211_dump_pkt(mtod(m, void *), m->m_len, -1, -1);
2006 #endif
2007 		m_freem(m);
2008 		return;
2009 	}
2010 	/*
2011 	 * Tag the frame with it's expiry time and insert
2012 	 * it in the queue.  The aging interval is 4 times
2013 	 * the listen interval specified by the station.
2014 	 * Frames that sit around too long are reclaimed
2015 	 * using this information.
2016 	 */
2017 	/* XXX handle overflow? */
2018 	age = ((ni->ni_intval * ic->ic_bintval) << 2) / 1024; /* TU -> secs */
2019 	_IEEE80211_NODE_SAVEQ_ENQUEUE(ni, m, qlen, age);
2020 	IEEE80211_NODE_SAVEQ_UNLOCK(ni);
2021 
2022 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
2023 		"[%s] save frame with age %d, %u now queued\n",
2024 		ether_sprintf(ni->ni_macaddr), age, qlen);
2025 
2026 	if (qlen == 1)
2027 		ic->ic_set_tim(ni, 1);
2028 }
2029