xref: /netbsd-src/sys/net80211/ieee80211_output.c (revision fd5cb0acea84d278e04e640d37ca2398f894991f)
1 /*	$NetBSD: ieee80211_output.c,v 1.27 2005/01/21 22:57:30 dyoung Exp $	*/
2 /*-
3  * Copyright (c) 2001 Atsushi Onoe
4  * Copyright (c) 2002, 2003 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 1.10 2004/04/02 23:25:39 sam Exp $");
37 #else
38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_output.c,v 1.27 2005/01/21 22:57:30 dyoung Exp $");
39 #endif
40 
41 #include "opt_inet.h"
42 
43 #ifdef __NetBSD__
44 #include "bpfilter.h"
45 #endif /* __NetBSD__ */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/malloc.h>
51 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/endian.h>
55 #include <sys/errno.h>
56 #ifdef __FreeBSD__
57 #include <sys/bus.h>
58 #endif
59 #include <sys/proc.h>
60 #include <sys/sysctl.h>
61 
62 #ifdef __FreeBSD__
63 #include <machine/atomic.h>
64 #endif
65 
66 #include <net/if.h>
67 #include <net/if_dl.h>
68 #include <net/if_media.h>
69 #include <net/if_arp.h>
70 #ifdef __FreeBSD__
71 #include <net/ethernet.h>
72 #else
73 #include <net/if_ether.h>
74 #endif
75 #include <net/if_llc.h>
76 
77 #include <net80211/ieee80211_var.h>
78 #include <net80211/ieee80211_compat.h>
79 
80 #if NBPFILTER > 0
81 #include <net/bpf.h>
82 #endif
83 
84 #ifdef INET
85 #include <netinet/in.h>
86 #ifdef __FreeBSD__
87 #include <netinet/if_ether.h>
88 #else
89 #include <net/if_ether.h>
90 #endif
91 #endif
92 
93 #ifdef IEEE80211_DEBUG
94 /*
95  * Decide if an outbound management frame should be
96  * printed when debugging is enabled.  This filters some
97  * of the less interesting frames that come frequently
98  * (e.g. beacons).
99  */
100 static __inline int
101 doprint(struct ieee80211com *ic, int subtype)
102 {
103 	switch (subtype) {
104 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
105 		return (ic->ic_opmode == IEEE80211_M_IBSS);
106 	}
107 	return 1;
108 }
109 #endif
110 
111 /*
112  * Send a management frame to the specified node.  The node pointer
113  * must have a reference as the pointer will be passed to the driver
114  * and potentially held for a long time.  If the frame is successfully
115  * dispatched to the driver, then it is responsible for freeing the
116  * reference (and potentially free'ing up any associated storage).
117  */
118 static int
119 ieee80211_mgmt_output(struct ifnet *ifp, struct ieee80211_node *ni,
120     struct mbuf *m, int type)
121 {
122 	struct ieee80211com *ic = (void *)ifp;
123 	struct ieee80211_frame *wh;
124 
125 	IASSERT(ni != NULL, ("null node"));
126 	ni->ni_inact = 0;
127 
128 	/*
129 	 * Yech, hack alert!  We want to pass the node down to the
130 	 * driver's start routine.  If we don't do so then the start
131 	 * routine must immediately look it up again and that can
132 	 * cause a lock order reversal if, for example, this frame
133 	 * is being sent because the station is being timedout and
134 	 * the frame being sent is a DEAUTH message.  We could stick
135 	 * this in an m_tag and tack that on to the mbuf.  However
136 	 * that's rather expensive to do for every frame so instead
137 	 * we stuff it in the rcvif field since outbound frames do
138 	 * not (presently) use this.
139 	 */
140 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
141 	if (m == NULL)
142 		return ENOMEM;
143 #ifdef __FreeBSD__
144 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
145 #endif
146 	m->m_pkthdr.rcvif = (void *)ni;
147 
148 	wh = mtod(m, struct ieee80211_frame *);
149 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT | type;
150 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
151 	*(u_int16_t *)&wh->i_dur[0] = 0;
152 	*(u_int16_t *)&wh->i_seq[0] =
153 	    htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT);
154 	ni->ni_txseq++;
155 	IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_macaddr);
156 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
157 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
158 
159 	if ((m->m_flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
160 		m->m_flags &= ~M_LINK0;
161 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
162 			("%s: encrypting frame for %s\n",
163 			__func__, ether_sprintf(wh->i_addr1)));
164 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
165 	}
166 #ifdef IEEE80211_DEBUG
167 	/* avoid printing too many frames */
168 	if ((ieee80211_msg_debug(ic) && doprint(ic, type)) ||
169 	    ieee80211_msg_dumppkts(ic)) {
170 		if_printf(ifp, "sending %s to %s on channel %u\n",
171 		    ieee80211_mgt_subtype_name[
172 		    (type & IEEE80211_FC0_SUBTYPE_MASK)
173 		    >> IEEE80211_FC0_SUBTYPE_SHIFT],
174 		    ether_sprintf(ni->ni_macaddr),
175 		    ieee80211_chan2ieee(ic, ni->ni_chan));
176 	}
177 #endif
178 	IF_ENQUEUE(&ic->ic_mgtq, m);
179 	ifp->if_timer = 1;
180 	(*ifp->if_start)(ifp);
181 	return 0;
182 }
183 
184 /*
185  * Encapsulate an outbound data frame.  The mbuf chain is updated and
186  * a reference to the destination node is returned.  If an error is
187  * encountered NULL is returned and the node reference will also be NULL.
188  *
189  * NB: The caller is responsible for free'ing a returned node reference.
190  *     The convention is ic_bss is not reference counted; the caller must
191  *     maintain that.
192  */
193 struct mbuf *
194 ieee80211_encap(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node **pni)
195 {
196 	struct ieee80211com *ic = (void *)ifp;
197 	struct ether_header eh;
198 	struct ieee80211_frame *wh;
199 	struct ieee80211_node *ni = NULL;
200 	struct llc *llc;
201 
202 	if (m->m_len < sizeof(struct ether_header)) {
203 		m = m_pullup(m, sizeof(struct ether_header));
204 		if (m == NULL) {
205 			ic->ic_stats.is_tx_nombuf++;
206 			goto bad;
207 		}
208 	}
209 	memcpy(&eh, mtod(m, caddr_t), sizeof(struct ether_header));
210 
211 	ni = ieee80211_find_txnode(ic, eh.ether_dhost);
212 	if (ni == NULL) {
213 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
214 			("%s: no node for dst %s, discard frame\n",
215 			__func__, ether_sprintf(eh.ether_dhost)));
216 		ic->ic_stats.is_tx_nonode++;
217 		goto bad;
218 	}
219 	ni->ni_inact = 0;
220 
221 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
222 	llc = mtod(m, struct llc *);
223 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
224 	llc->llc_control = LLC_UI;
225 	llc->llc_snap.org_code[0] = 0;
226 	llc->llc_snap.org_code[1] = 0;
227 	llc->llc_snap.org_code[2] = 0;
228 	llc->llc_snap.ether_type = eh.ether_type;
229 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
230 	if (m == NULL) {
231 		ic->ic_stats.is_tx_nombuf++;
232 		goto bad;
233 	}
234 	wh = mtod(m, struct ieee80211_frame *);
235 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
236 	*(u_int16_t *)&wh->i_dur[0] = 0;
237 	*(u_int16_t *)&wh->i_seq[0] =
238 	    htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT);
239 	ni->ni_txseq++;
240 	switch (ic->ic_opmode) {
241 	case IEEE80211_M_STA:
242 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
243 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
244 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
245 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
246 		break;
247 	case IEEE80211_M_IBSS:
248 	case IEEE80211_M_AHDEMO:
249 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
250 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
251 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
252 		IEEE80211_ADDR_COPY(wh->i_addr3, ic->ic_bss->ni_bssid);
253 		break;
254 	case IEEE80211_M_HOSTAP:
255 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
256 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
257 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
258 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
259 		break;
260 	case IEEE80211_M_MONITOR:
261 		goto bad;
262 	}
263 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
264 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
265 	*pni = ni;
266 	return m;
267 bad:
268 	if (m != NULL)
269 		m_freem(m);
270 	if (ni != NULL)
271 		ieee80211_release_node(ic, ni);
272 	*pni = NULL;
273 	return NULL;
274 }
275 
276 /*
277  * Arguments in:
278  *
279  * paylen:  payload length (no FCS, no WEP header)
280  *
281  * hdrlen:  header length
282  *
283  * rate:    MSDU speed, units 500kb/s
284  *
285  * flags:   IEEE80211_F_SHPREAMBLE (use short preamble),
286  *          IEEE80211_F_SHSLOT (use short slot length)
287  *
288  * Arguments out:
289  *
290  * d:       802.11 Duration field for RTS,
291  *          802.11 Duration field for data frame,
292  *          PLCP Length for data frame,
293  *          residual octets at end of data slot
294  */
295 static int
296 ieee80211_compute_duration1(int len, int use_ack, uint32_t flags, int rate,
297     struct ieee80211_duration *d)
298 {
299 	int pre, ctsrate;
300 	int ack, bitlen, data_dur, remainder;
301 
302 	/* RTS reserves medium for SIFS | CTS | SIFS | (DATA) | SIFS | ACK
303 	 * DATA reserves medium for SIFS | ACK
304 	 *
305 	 * XXXMYC: no ACK on multicast/broadcast or control packets
306 	 */
307 
308 	bitlen = len * 8;
309 
310 	pre = IEEE80211_DUR_DS_SIFS;
311 	if ((flags & IEEE80211_F_SHPREAMBLE) != 0)
312 		pre += IEEE80211_DUR_DS_SHORT_PREAMBLE + IEEE80211_DUR_DS_FAST_PLCPHDR;
313 	else
314 		pre += IEEE80211_DUR_DS_LONG_PREAMBLE + IEEE80211_DUR_DS_SLOW_PLCPHDR;
315 
316 	d->d_residue = 0;
317 	data_dur = (bitlen * 2) / rate;
318 	remainder = (bitlen * 2) % rate;
319 	if (remainder != 0) {
320 		d->d_residue = (rate - remainder) / 16;
321 		data_dur++;
322 	}
323 
324 	switch (rate) {
325 	case 2:		/* 1 Mb/s */
326 	case 4:		/* 2 Mb/s */
327 		/* 1 - 2 Mb/s WLAN: send ACK/CTS at 1 Mb/s */
328 		ctsrate = 2;
329 		break;
330 	case 11:	/* 5.5 Mb/s */
331 	case 22:	/* 11  Mb/s */
332 	case 44:	/* 22  Mb/s */
333 		/* 5.5 - 11 Mb/s WLAN: send ACK/CTS at 2 Mb/s */
334 		ctsrate = 4;
335 		break;
336 	default:
337 		/* TBD */
338 		return -1;
339 	}
340 
341 	d->d_plcp_len = data_dur;
342 
343 	ack = (use_ack) ? pre + (IEEE80211_DUR_DS_SLOW_ACK * 2) / ctsrate : 0;
344 
345 	d->d_rts_dur =
346 	    pre + (IEEE80211_DUR_DS_SLOW_CTS * 2) / ctsrate +
347 	    pre + data_dur +
348 	    ack;
349 
350 	d->d_data_dur = ack;
351 
352 	return 0;
353 }
354 
355 /*
356  * Arguments in:
357  *
358  * wh:      802.11 header
359  *
360  * paylen:  payload length (no FCS, no WEP header)
361  *
362  * rate:    MSDU speed, units 500kb/s
363  *
364  * fraglen: fragment length, set to maximum (or higher) for no
365  *          fragmentation
366  *
367  * flags:   IEEE80211_F_PRIVACY (hardware adds WEP),
368  *          IEEE80211_F_SHPREAMBLE (use short preamble),
369  *          IEEE80211_F_SHSLOT (use short slot length)
370  *
371  * Arguments out:
372  *
373  * d0: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
374  *     of first/only fragment
375  *
376  * dn: 802.11 Duration fields (RTS/Data), PLCP Length, Service fields
377  *     of first/only fragment
378  */
379 int
380 ieee80211_compute_duration(struct ieee80211_frame *wh, int len,
381     uint32_t flags, int fraglen, int rate, struct ieee80211_duration *d0,
382     struct ieee80211_duration *dn, int *npktp, int debug)
383 {
384 	int ack, rc;
385 	int firstlen, hdrlen, lastlen, lastlen0, npkt, overlen, paylen;
386 
387 	if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS)
388 		hdrlen = sizeof(struct ieee80211_frame_addr4);
389 	else
390 		hdrlen = sizeof(struct ieee80211_frame);
391 
392 	paylen = len - hdrlen;
393 
394 	if ((flags & IEEE80211_F_PRIVACY) != 0)
395 		overlen = IEEE80211_WEP_TOTLEN + IEEE80211_CRC_LEN;
396 	else
397 		overlen = IEEE80211_CRC_LEN;
398 
399 	npkt = paylen / fraglen;
400 	lastlen0 = paylen % fraglen;
401 
402 	if (npkt == 0)			/* no fragments */
403 		lastlen = paylen + overlen;
404 	else if (lastlen0 != 0) {	/* a short "tail" fragment */
405 		lastlen = lastlen0 + overlen;
406 		npkt++;
407 	} else				/* full-length "tail" fragment */
408 		lastlen = fraglen + overlen;
409 
410 	if (npktp != NULL)
411 		*npktp = npkt;
412 
413 	if (npkt > 1)
414 		firstlen = fraglen + overlen;
415 	else
416 		firstlen = paylen + overlen;
417 
418 	if (debug) {
419 		printf("%s: npkt %d firstlen %d lastlen0 %d lastlen %d "
420 		    "fraglen %d overlen %d len %d rate %d flags %08x\n",
421 		    __func__, npkt, firstlen, lastlen0, lastlen, fraglen,
422 		    overlen, len, rate, flags);
423 	}
424 
425 	ack = !IEEE80211_IS_MULTICAST(wh->i_addr1) &&
426 	    (wh->i_fc[1] & IEEE80211_FC0_TYPE_MASK) != IEEE80211_FC0_TYPE_CTL;
427 
428 	rc = ieee80211_compute_duration1(firstlen + hdrlen,
429 	    ack, flags, rate, d0);
430 	if (rc == -1)
431 		return rc;
432 
433 	if (npkt <= 1) {
434 		*dn = *d0;
435 		return 0;
436 	}
437 	return ieee80211_compute_duration1(lastlen + hdrlen, ack, flags, rate,
438 	    dn);
439 }
440 
441 /*
442  * Add a supported rates element id to a frame.
443  */
444 u_int8_t *
445 ieee80211_add_rates(u_int8_t *frm, const struct ieee80211_rateset *rs)
446 {
447 	int nrates;
448 
449 	*frm++ = IEEE80211_ELEMID_RATES;
450 	nrates = rs->rs_nrates;
451 	if (nrates > IEEE80211_RATE_SIZE)
452 		nrates = IEEE80211_RATE_SIZE;
453 	*frm++ = nrates;
454 	memcpy(frm, rs->rs_rates, nrates);
455 	return frm + nrates;
456 }
457 
458 /*
459  * Add an extended supported rates element id to a frame.
460  */
461 u_int8_t *
462 ieee80211_add_xrates(u_int8_t *frm, const struct ieee80211_rateset *rs)
463 {
464 	/*
465 	 * Add an extended supported rates element if operating in 11g mode.
466 	 */
467 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
468 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
469 		*frm++ = IEEE80211_ELEMID_XRATES;
470 		*frm++ = nrates;
471 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
472 		frm += nrates;
473 	}
474 	return frm;
475 }
476 
477 /*
478  * Add an ssid elemet to a frame.
479  */
480 static u_int8_t *
481 ieee80211_add_ssid(u_int8_t *frm, const u_int8_t *ssid, u_int len)
482 {
483 	*frm++ = IEEE80211_ELEMID_SSID;
484 	*frm++ = len;
485 	memcpy(frm, ssid, len);
486 	return frm + len;
487 }
488 
489 static struct mbuf *
490 ieee80211_getmbuf(int flags, int type, u_int pktlen)
491 {
492 	struct mbuf *m;
493 
494 	IASSERT(pktlen <= MCLBYTES, ("802.11 packet too large: %u", pktlen));
495 	MGETHDR(m, flags, type);
496 	if (m == NULL || pktlen <= MHLEN)
497 		return m;
498 	MCLGET(m, flags);
499 	if ((m->m_flags & M_EXT) != 0)
500 		return m;
501 	m_free(m);
502 	return NULL;
503 }
504 
505 /*
506  * Send a management frame.  The node is for the destination (or ic_bss
507  * when in station mode).  Nodes other than ic_bss have their reference
508  * count bumped to reflect our use for an indeterminant time.
509  */
510 int
511 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
512 	int type, int arg)
513 {
514 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
515 	struct ifnet *ifp = &ic->ic_if;
516 	struct mbuf *m;
517 	u_int8_t *frm;
518 	enum ieee80211_phymode mode;
519 	u_int16_t capinfo;
520 	int has_challenge, is_shared_key, ret, timer;
521 
522 	IASSERT(ni != NULL, ("null node"));
523 
524 	/*
525 	 * Hold a reference on the node so it doesn't go away until after
526 	 * the xmit is complete all the way in the driver.  On error we
527 	 * will remove our reference.
528 	 */
529 	ieee80211_ref_node(ni);
530 	timer = 0;
531 	switch (type) {
532 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
533 		/*
534 		 * prreq frame format
535 		 *	[tlv] ssid
536 		 *	[tlv] supported rates
537 		 *	[tlv] extended supported rates
538 		 */
539 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
540 			 2 + ic->ic_des_esslen
541 		       + 2 + IEEE80211_RATE_SIZE
542 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
543 		if (m == NULL)
544 			senderr(ENOMEM, is_tx_nombuf);
545 		m->m_data += sizeof(struct ieee80211_frame);
546 		frm = mtod(m, u_int8_t *);
547 		frm = ieee80211_add_ssid(frm, ic->ic_des_essid, ic->ic_des_esslen);
548 		mode = ieee80211_chan2mode(ic, ni->ni_chan);
549 		frm = ieee80211_add_rates(frm, &ic->ic_sup_rates[mode]);
550 		frm = ieee80211_add_xrates(frm, &ic->ic_sup_rates[mode]);
551 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
552 
553 		timer = IEEE80211_TRANS_WAIT;
554 		break;
555 
556 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
557 		/*
558 		 * probe response frame format
559 		 *	[8] time stamp
560 		 *	[2] beacon interval
561 		 *	[2] cabability information
562 		 *	[tlv] ssid
563 		 *	[tlv] supported rates
564 		 *	[tlv] parameter set (FH/DS)
565 		 *	[tlv] parameter set (IBSS)
566 		 *	[tlv] extended supported rates
567 		 */
568 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
569 			 8 + 2 + 2 + 2
570 		       + 2 + ni->ni_esslen
571 		       + 2 + IEEE80211_RATE_SIZE
572 		       + (ic->ic_phytype == IEEE80211_T_FH ? 7 : 3)
573 		       + 6
574 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
575 		if (m == NULL)
576 			senderr(ENOMEM, is_tx_nombuf);
577 		m->m_data += sizeof(struct ieee80211_frame);
578 		frm = mtod(m, u_int8_t *);
579 
580 		memset(frm, 0, 8);	/* timestamp should be filled later */
581 		frm += 8;
582 		*(u_int16_t *)frm = htole16(ic->ic_bss->ni_intval);
583 		frm += 2;
584 		if (ic->ic_opmode == IEEE80211_M_IBSS)
585 			capinfo = IEEE80211_CAPINFO_IBSS;
586 		else
587 			capinfo = IEEE80211_CAPINFO_ESS;
588 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
589 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
590 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
591 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
592 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
593 		*(u_int16_t *)frm = htole16(capinfo);
594 		frm += 2;
595 
596 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
597 				ic->ic_bss->ni_esslen);
598 		frm = ieee80211_add_rates(frm, &ic->ic_bss->ni_rates);
599 
600 		if (ic->ic_phytype == IEEE80211_T_FH) {
601                         *frm++ = IEEE80211_ELEMID_FHPARMS;
602                         *frm++ = 5;
603                         *frm++ = ni->ni_fhdwell & 0x00ff;
604                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
605                         *frm++ = IEEE80211_FH_CHANSET(
606 			    ieee80211_chan2ieee(ic, ni->ni_chan));
607                         *frm++ = IEEE80211_FH_CHANPAT(
608 			    ieee80211_chan2ieee(ic, ni->ni_chan));
609                         *frm++ = ni->ni_fhindex;
610 		} else {
611 			*frm++ = IEEE80211_ELEMID_DSPARMS;
612 			*frm++ = 1;
613 			*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
614 		}
615 
616 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
617 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
618 			*frm++ = 2;
619 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
620 		} else {	/* IEEE80211_M_HOSTAP */
621 			/* TODO: TIM */
622 			*frm++ = IEEE80211_ELEMID_TIM;
623 			*frm++ = 4;	/* length */
624 			*frm++ = 0;	/* DTIM count */
625 			*frm++ = 1;	/* DTIM period */
626 			*frm++ = 0;	/* bitmap control */
627 			*frm++ = 0;	/* Partial Virtual Bitmap (variable length) */
628 		}
629 		frm = ieee80211_add_xrates(frm, &ic->ic_bss->ni_rates);
630 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
631 		break;
632 
633 	case IEEE80211_FC0_SUBTYPE_AUTH:
634 		MGETHDR(m, M_DONTWAIT, MT_DATA);
635 		if (m == NULL)
636 			senderr(ENOMEM, is_tx_nombuf);
637 
638 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
639 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
640 		    ni->ni_challenge != NULL);
641 
642 		is_shared_key = has_challenge || (ni->ni_challenge != NULL &&
643 		    arg == IEEE80211_AUTH_SHARED_PASS);
644 
645 		if (has_challenge) {
646 			MH_ALIGN(m, 2 * 3 + 2 + IEEE80211_CHALLENGE_LEN);
647 			m->m_pkthdr.len = m->m_len =
648 			    2 * 3 + 2 + IEEE80211_CHALLENGE_LEN;
649 		} else {
650 			MH_ALIGN(m, 2 * 3);
651 			m->m_pkthdr.len = m->m_len = 2 * 3;
652 		}
653 		frm = mtod(m, u_int8_t *);
654 		((u_int16_t *)frm)[0] =
655 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
656 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
657 		((u_int16_t *)frm)[1] = htole16(arg);	/* sequence number */
658 		((u_int16_t *)frm)[2] = 0;		/* status */
659 
660 		if (has_challenge) {
661 			((u_int16_t *)frm)[3] =
662 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
663 			    IEEE80211_ELEMID_CHALLENGE);
664 			memcpy(&((u_int16_t *)frm)[4], ni->ni_challenge,
665 			    IEEE80211_CHALLENGE_LEN);
666 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
667 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
668 				    ("%s: request encrypt frame\n", __func__));
669 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
670 			}
671 		}
672 		if (ic->ic_opmode == IEEE80211_M_STA)
673 			timer = IEEE80211_TRANS_WAIT;
674 		break;
675 
676 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
677 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
678 			("send station %s deauthenticate (reason %d)\n",
679 			ether_sprintf(ni->ni_macaddr), arg));
680 		MGETHDR(m, M_DONTWAIT, MT_DATA);
681 		if (m == NULL)
682 			senderr(ENOMEM, is_tx_nombuf);
683 		MH_ALIGN(m, 2);
684 		m->m_pkthdr.len = m->m_len = 2;
685 		*mtod(m, u_int16_t *) = htole16(arg);	/* reason */
686 		break;
687 
688 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
689 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
690 		/*
691 		 * asreq frame format
692 		 *	[2] capability information
693 		 *	[2] listen interval
694 		 *	[6*] current AP address (reassoc only)
695 		 *	[tlv] ssid
696 		 *	[tlv] supported rates
697 		 *	[tlv] extended supported rates
698 		 */
699 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
700 			 sizeof(capinfo)
701 		       + sizeof(u_int16_t)
702 		       + IEEE80211_ADDR_LEN
703 		       + 2 + ni->ni_esslen
704 		       + 2 + IEEE80211_RATE_SIZE
705 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
706 		if (m == NULL)
707 			senderr(ENOMEM, is_tx_nombuf);
708 		m->m_data += sizeof(struct ieee80211_frame);
709 		frm = mtod(m, u_int8_t *);
710 
711 		capinfo = 0;
712 		if (ic->ic_opmode == IEEE80211_M_IBSS)
713 			capinfo |= IEEE80211_CAPINFO_IBSS;
714 		else		/* IEEE80211_M_STA */
715 			capinfo |= IEEE80211_CAPINFO_ESS;
716 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
717 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
718 		/*
719 		 * NB: Some 11a AP's reject the request when
720 		 *     short premable is set.
721 		 */
722 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
723 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
724 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
725 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
726 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
727 		*(u_int16_t *)frm = htole16(capinfo);
728 		frm += 2;
729 
730 		*(u_int16_t *)frm = htole16(ic->ic_lintval);
731 		frm += 2;
732 
733 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
734 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
735 			frm += IEEE80211_ADDR_LEN;
736 		}
737 
738 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
739 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
740 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
741 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
742 
743 		timer = IEEE80211_TRANS_WAIT;
744 		break;
745 
746 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
747 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
748 		/*
749 		 * asreq frame format
750 		 *	[2] capability information
751 		 *	[2] status
752 		 *	[2] association ID
753 		 *	[tlv] supported rates
754 		 *	[tlv] extended supported rates
755 		 */
756 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
757 			 sizeof(capinfo)
758 		       + sizeof(u_int16_t)
759 		       + sizeof(u_int16_t)
760 		       + 2 + IEEE80211_RATE_SIZE
761 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
762 		if (m == NULL)
763 			senderr(ENOMEM, is_tx_nombuf);
764 		m->m_data += sizeof(struct ieee80211_frame);
765 		frm = mtod(m, u_int8_t *);
766 
767 		capinfo = IEEE80211_CAPINFO_ESS;
768 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
769 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
770 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
771 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
772 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
773 		*(u_int16_t *)frm = htole16(capinfo);
774 		frm += 2;
775 
776 		*(u_int16_t *)frm = htole16(arg);	/* status */
777 		frm += 2;
778 
779 		if (arg == IEEE80211_STATUS_SUCCESS)
780 			*(u_int16_t *)frm = htole16(ni->ni_associd);
781 		frm += 2;
782 
783 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
784 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
785 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
786 		break;
787 
788 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
789 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
790 			("send station %s disassociate (reason %d)\n",
791 			ether_sprintf(ni->ni_macaddr), arg));
792 		MGETHDR(m, M_DONTWAIT, MT_DATA);
793 		if (m == NULL)
794 			senderr(ENOMEM, is_tx_nombuf);
795 		MH_ALIGN(m, 2);
796 		m->m_pkthdr.len = m->m_len = 2;
797 		*mtod(m, u_int16_t *) = htole16(arg);	/* reason */
798 		break;
799 
800 	default:
801 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
802 			("%s: invalid mgmt frame type %u\n", __func__, type));
803 		senderr(EINVAL, is_tx_unknownmgt);
804 		/* NOTREACHED */
805 	}
806 
807 	ret = ieee80211_mgmt_output(ifp, ni, m, type);
808 	if (ret == 0) {
809 		if (timer)
810 			ic->ic_mgt_timer = timer;
811 	} else {
812 bad:
813 		ieee80211_release_node(ic, ni);
814 	}
815 	return ret;
816 #undef senderr
817 }
818 
819 void
820 ieee80211_pwrsave(struct ieee80211com *ic, struct ieee80211_node *ni,
821 		  struct mbuf *m)
822 {
823 	/* Store the new packet on our queue, changing the TIM if necessary */
824 
825 	if (IF_IS_EMPTY(&ni->ni_savedq)) {
826 		ic->ic_set_tim(ic, ni->ni_associd, 1);
827 	}
828 	if (ni->ni_savedq.ifq_len >= IEEE80211_PS_MAX_QUEUE) {
829 		IF_DROP(&ni->ni_savedq);
830 		m_freem(m);
831 		if (ic->ic_if.if_flags & IFF_DEBUG)
832 			printf("%s: station %s power save queue overflow"
833 			       " of size %d drops %d\n",
834 			       ic->ic_if.if_xname,
835 			       ether_sprintf(ni->ni_macaddr),
836 			       IEEE80211_PS_MAX_QUEUE,
837 			       ni->ni_savedq.ifq_drops);
838 	} else {
839 		/* Similar to ieee80211_mgmt_output, store the node in
840 		 * the rcvif field.
841 		 */
842 		IF_ENQUEUE(&ni->ni_savedq, m);
843 		m->m_pkthdr.rcvif = (void *)ni;
844 	}
845 }
846 
847