ieee80211_adhoc.c revision 186904
1/*-
2 * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27#ifdef __FreeBSD__
28__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_adhoc.c 186904 2009-01-08 17:12:47Z sam $");
29#endif
30
31/*
32 * IEEE 802.11 IBSS mode support.
33 */
34#include "opt_inet.h"
35#include "opt_wlan.h"
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/mbuf.h>
40#include <sys/malloc.h>
41#include <sys/kernel.h>
42
43#include <sys/socket.h>
44#include <sys/sockio.h>
45#include <sys/endian.h>
46#include <sys/errno.h>
47#include <sys/proc.h>
48#include <sys/sysctl.h>
49
50#include <net/if.h>
51#include <net/if_media.h>
52#include <net/if_llc.h>
53#include <net/ethernet.h>
54
55#include <net/bpf.h>
56
57#include <net80211/ieee80211_var.h>
58#include <net80211/ieee80211_adhoc.h>
59#include <net80211/ieee80211_input.h>
60#ifdef IEEE80211_SUPPORT_TDMA
61#include <net80211/ieee80211_tdma.h>
62#endif
63
64#define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
65
66static	void adhoc_vattach(struct ieee80211vap *);
67static	int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
68static int adhoc_input(struct ieee80211_node *, struct mbuf *,
69	int rssi, int noise, uint32_t rstamp);
70static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
71	int subtype, int rssi, int noise, uint32_t rstamp);
72static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
73	int subtype, int rssi, int noise, uint32_t rstamp);
74
75void
76ieee80211_adhoc_attach(struct ieee80211com *ic)
77{
78	ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
79	ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
80}
81
82void
83ieee80211_adhoc_detach(struct ieee80211com *ic)
84{
85}
86
87static void
88adhoc_vdetach(struct ieee80211vap *vap)
89{
90}
91
92static void
93adhoc_vattach(struct ieee80211vap *vap)
94{
95	vap->iv_newstate = adhoc_newstate;
96	vap->iv_input = adhoc_input;
97	if (vap->iv_opmode == IEEE80211_M_IBSS)
98		vap->iv_recv_mgmt = adhoc_recv_mgmt;
99	else
100		vap->iv_recv_mgmt = ahdemo_recv_mgmt;
101	vap->iv_opdetach = adhoc_vdetach;
102#ifdef IEEE80211_SUPPORT_TDMA
103	/*
104	 * Throw control to tdma support.  Note we do this
105	 * after setting up our callbacks so it can piggyback
106	 * on top of us.
107	 */
108	if (vap->iv_caps & IEEE80211_C_TDMA)
109		ieee80211_tdma_vattach(vap);
110#endif
111}
112
113/*
114 * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
115 */
116static int
117adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
118{
119	struct ieee80211com *ic = vap->iv_ic;
120	struct ieee80211_node *ni;
121	enum ieee80211_state ostate;
122
123	IEEE80211_LOCK_ASSERT(vap->iv_ic);
124
125	ostate = vap->iv_state;
126	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
127	    __func__, ieee80211_state_name[ostate],
128	    ieee80211_state_name[nstate], arg);
129	vap->iv_state = nstate;			/* state transition */
130	if (ostate != IEEE80211_S_SCAN)
131		ieee80211_cancel_scan(vap);	/* background scan */
132	ni = vap->iv_bss;			/* NB: no reference held */
133	switch (nstate) {
134	case IEEE80211_S_INIT:
135		switch (ostate) {
136		case IEEE80211_S_SCAN:
137			ieee80211_cancel_scan(vap);
138			break;
139		default:
140			break;
141		}
142		if (ostate != IEEE80211_S_INIT) {
143			/* NB: optimize INIT -> INIT case */
144			ieee80211_reset_bss(vap);
145		}
146		break;
147	case IEEE80211_S_SCAN:
148		switch (ostate) {
149		case IEEE80211_S_INIT:
150		case IEEE80211_S_RUN:		/* beacon miss */
151			if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
152			    !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
153				/*
154				 * Already have a channel; bypass the
155				 * scan and startup immediately.
156				 */
157				ieee80211_create_ibss(vap, vap->iv_des_chan);
158				break;
159			}
160			/*
161			 * Initiate a scan.  We can come here as a result
162			 * of an IEEE80211_IOC_SCAN_REQ too in which case
163			 * the vap will be marked with IEEE80211_FEXT_SCANREQ
164			 * and the scan request parameters will be present
165			 * in iv_scanreq.  Otherwise we do the default.
166			 */
167			if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
168				ieee80211_check_scan(vap,
169				    vap->iv_scanreq_flags,
170				    vap->iv_scanreq_duration,
171				    vap->iv_scanreq_mindwell,
172				    vap->iv_scanreq_maxdwell,
173				    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
174				vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
175			} else
176				ieee80211_check_scan_current(vap);
177			break;
178		case IEEE80211_S_SCAN:
179			/*
180			 * This can happen because of a change in state
181			 * that requires a reset.  Trigger a new scan
182			 * unless we're in manual roaming mode in which
183			 * case an application must issue an explicit request.
184			 */
185			if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
186				ieee80211_check_scan_current(vap);
187			break;
188		default:
189			goto invalid;
190		}
191		break;
192	case IEEE80211_S_RUN:
193		if (vap->iv_flags & IEEE80211_F_WPA) {
194			/* XXX validate prerequisites */
195		}
196		switch (ostate) {
197		case IEEE80211_S_SCAN:
198#ifdef IEEE80211_DEBUG
199			if (ieee80211_msg_debug(vap)) {
200				ieee80211_note(vap,
201				    "synchronized with %s ssid ",
202				    ether_sprintf(ni->ni_bssid));
203				ieee80211_print_essid(vap->iv_bss->ni_essid,
204				    ni->ni_esslen);
205				/* XXX MCS/HT */
206				printf(" channel %d start %uMb\n",
207				    ieee80211_chan2ieee(ic, ic->ic_curchan),
208				    IEEE80211_RATE2MBS(ni->ni_txrate));
209			}
210#endif
211			break;
212		default:
213			goto invalid;
214		}
215		/*
216		 * When 802.1x is not in use mark the port authorized
217		 * at this point so traffic can flow.
218		 */
219		if (ni->ni_authmode != IEEE80211_AUTH_8021X)
220			ieee80211_node_authorize(ni);
221		/*
222		 * Fake association when joining an existing bss.
223		 */
224		if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
225		    ic->ic_newassoc != NULL)
226			ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
227		break;
228	case IEEE80211_S_SLEEP:
229		ieee80211_sta_pwrsave(vap, 0);
230		break;
231	default:
232	invalid:
233		IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
234		    "%s: unexpected state transition %s -> %s\n", __func__,
235		    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
236		break;
237	}
238	return 0;
239}
240
241/*
242 * Decide if a received management frame should be
243 * printed when debugging is enabled.  This filters some
244 * of the less interesting frames that come frequently
245 * (e.g. beacons).
246 */
247static __inline int
248doprint(struct ieee80211vap *vap, int subtype)
249{
250	switch (subtype) {
251	case IEEE80211_FC0_SUBTYPE_BEACON:
252		return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
253	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
254		return 1;
255	}
256	return 1;
257}
258
259/*
260 * Process a received frame.  The node associated with the sender
261 * should be supplied.  If nothing was found in the node table then
262 * the caller is assumed to supply a reference to iv_bss instead.
263 * The RSSI and a timestamp are also supplied.  The RSSI data is used
264 * during AP scanning to select a AP to associate with; it can have
265 * any units so long as values have consistent units and higher values
266 * mean ``better signal''.  The receive timestamp is currently not used
267 * by the 802.11 layer.
268 */
269static int
270adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
271	int rssi, int noise, uint32_t rstamp)
272{
273#define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
274#define	HAS_SEQ(type)	((type & 0x4) == 0)
275	struct ieee80211vap *vap = ni->ni_vap;
276	struct ieee80211com *ic = ni->ni_ic;
277	struct ifnet *ifp = vap->iv_ifp;
278	struct ieee80211_frame *wh;
279	struct ieee80211_key *key;
280	struct ether_header *eh;
281	int hdrspace, need_tap;
282	uint8_t dir, type, subtype, qos;
283	uint8_t *bssid;
284	uint16_t rxseq;
285
286	if (m->m_flags & M_AMPDU_MPDU) {
287		/*
288		 * Fastpath for A-MPDU reorder q resubmission.  Frames
289		 * w/ M_AMPDU_MPDU marked have already passed through
290		 * here but were received out of order and been held on
291		 * the reorder queue.  When resubmitted they are marked
292		 * with the M_AMPDU_MPDU flag and we can bypass most of
293		 * the normal processing.
294		 */
295		wh = mtod(m, struct ieee80211_frame *);
296		type = IEEE80211_FC0_TYPE_DATA;
297		dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
298		subtype = IEEE80211_FC0_SUBTYPE_QOS;
299		hdrspace = ieee80211_hdrspace(ic, wh);	/* XXX optimize? */
300		goto resubmit_ampdu;
301	}
302
303	KASSERT(ni != NULL, ("null node"));
304	ni->ni_inact = ni->ni_inact_reload;
305
306	need_tap = 1;			/* mbuf need to be tapped. */
307	type = -1;			/* undefined */
308
309	if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
310		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
311		    ni->ni_macaddr, NULL,
312		    "too short (1): len %u", m->m_pkthdr.len);
313		vap->iv_stats.is_rx_tooshort++;
314		goto out;
315	}
316	/*
317	 * Bit of a cheat here, we use a pointer for a 3-address
318	 * frame format but don't reference fields past outside
319	 * ieee80211_frame_min w/o first validating the data is
320	 * present.
321	 */
322	wh = mtod(m, struct ieee80211_frame *);
323
324	if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
325	    IEEE80211_FC0_VERSION_0) {
326		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
327		    ni->ni_macaddr, NULL, "wrong version %x", wh->i_fc[0]);
328		vap->iv_stats.is_rx_badversion++;
329		goto err;
330	}
331
332	dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
333	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
334	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
335	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
336		if (dir != IEEE80211_FC1_DIR_NODS)
337			bssid = wh->i_addr1;
338		else if (type == IEEE80211_FC0_TYPE_CTL)
339			bssid = wh->i_addr1;
340		else {
341			if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
342				IEEE80211_DISCARD_MAC(vap,
343				    IEEE80211_MSG_ANY, ni->ni_macaddr,
344				    NULL, "too short (2): len %u",
345				    m->m_pkthdr.len);
346				vap->iv_stats.is_rx_tooshort++;
347				goto out;
348			}
349			bssid = wh->i_addr3;
350		}
351		/*
352		 * Validate the bssid.
353		 */
354		if (!IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
355		    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
356			/* not interested in */
357			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
358			    bssid, NULL, "%s", "not to bss");
359			vap->iv_stats.is_rx_wrongbss++;
360			goto out;
361		}
362		/*
363		 * Data frame, cons up a node when it doesn't
364		 * exist. This should probably done after an ACL check.
365		 */
366		if (type == IEEE80211_FC0_TYPE_DATA &&
367		    ni == vap->iv_bss &&
368		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
369			/*
370			 * Beware of frames that come in too early; we
371			 * can receive broadcast frames and creating sta
372			 * entries will blow up because there is no bss
373			 * channel yet.
374			 */
375			if (vap->iv_state != IEEE80211_S_RUN) {
376				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
377				    wh, "data", "not in RUN state (%s)",
378				    ieee80211_state_name[vap->iv_state]);
379				vap->iv_stats.is_rx_badstate++;
380				goto err;
381			}
382			/*
383			 * Fake up a node for this newly
384			 * discovered member of the IBSS.
385			 */
386			ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
387			if (ni == NULL) {
388				/* NB: stat kept for alloc failure */
389				goto err;
390			}
391		}
392		IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
393		ni->ni_noise = noise;
394		ni->ni_rstamp = rstamp;
395		if (HAS_SEQ(type)) {
396			uint8_t tid = ieee80211_gettid(wh);
397			if (IEEE80211_QOS_HAS_SEQ(wh) &&
398			    TID_TO_WME_AC(tid) >= WME_AC_VI)
399				ic->ic_wme.wme_hipri_traffic++;
400			rxseq = le16toh(*(uint16_t *)wh->i_seq);
401			if ((ni->ni_flags & IEEE80211_NODE_HT) == 0 &&
402			    (wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
403			    SEQ_LEQ(rxseq, ni->ni_rxseqs[tid])) {
404				/* duplicate, discard */
405				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
406				    bssid, "duplicate",
407				    "seqno <%u,%u> fragno <%u,%u> tid %u",
408				    rxseq >> IEEE80211_SEQ_SEQ_SHIFT,
409				    ni->ni_rxseqs[tid] >>
410					IEEE80211_SEQ_SEQ_SHIFT,
411				    rxseq & IEEE80211_SEQ_FRAG_MASK,
412				    ni->ni_rxseqs[tid] &
413					IEEE80211_SEQ_FRAG_MASK,
414				    tid);
415				vap->iv_stats.is_rx_dup++;
416				IEEE80211_NODE_STAT(ni, rx_dup);
417				goto out;
418			}
419			ni->ni_rxseqs[tid] = rxseq;
420		}
421	}
422
423	switch (type) {
424	case IEEE80211_FC0_TYPE_DATA:
425		hdrspace = ieee80211_hdrspace(ic, wh);
426		if (m->m_len < hdrspace &&
427		    (m = m_pullup(m, hdrspace)) == NULL) {
428			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
429			    ni->ni_macaddr, NULL,
430			    "data too short: expecting %u", hdrspace);
431			vap->iv_stats.is_rx_tooshort++;
432			goto out;		/* XXX */
433		}
434		if (dir != IEEE80211_FC1_DIR_NODS) {
435			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
436			    wh, "data", "incorrect dir 0x%x", dir);
437			vap->iv_stats.is_rx_wrongdir++;
438			goto out;
439		}
440		/* XXX no power-save support */
441
442		/*
443		 * Handle A-MPDU re-ordering.  If the frame is to be
444		 * processed directly then ieee80211_ampdu_reorder
445		 * will return 0; otherwise it has consumed the mbuf
446		 * and we should do nothing more with it.
447		 */
448		if ((m->m_flags & M_AMPDU) &&
449		    ieee80211_ampdu_reorder(ni, m) != 0) {
450			m = NULL;
451			goto out;
452		}
453	resubmit_ampdu:
454
455		/*
456		 * Handle privacy requirements.  Note that we
457		 * must not be preempted from here until after
458		 * we (potentially) call ieee80211_crypto_demic;
459		 * otherwise we may violate assumptions in the
460		 * crypto cipher modules used to do delayed update
461		 * of replay sequence numbers.
462		 */
463		if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
464			if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
465				/*
466				 * Discard encrypted frames when privacy is off.
467				 */
468				IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
469				    wh, "WEP", "%s", "PRIVACY off");
470				vap->iv_stats.is_rx_noprivacy++;
471				IEEE80211_NODE_STAT(ni, rx_noprivacy);
472				goto out;
473			}
474			key = ieee80211_crypto_decap(ni, m, hdrspace);
475			if (key == NULL) {
476				/* NB: stats+msgs handled in crypto_decap */
477				IEEE80211_NODE_STAT(ni, rx_wepfail);
478				goto out;
479			}
480			wh = mtod(m, struct ieee80211_frame *);
481			wh->i_fc[1] &= ~IEEE80211_FC1_WEP;
482		} else {
483			/* XXX M_WEP and IEEE80211_F_PRIVACY */
484			key = NULL;
485		}
486
487		/*
488		 * Save QoS bits for use below--before we strip the header.
489		 */
490		if (subtype == IEEE80211_FC0_SUBTYPE_QOS) {
491			qos = (dir == IEEE80211_FC1_DIR_DSTODS) ?
492			    ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0] :
493			    ((struct ieee80211_qosframe *)wh)->i_qos[0];
494		} else
495			qos = 0;
496
497		/*
498		 * Next up, any fragmentation.
499		 */
500		if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
501			m = ieee80211_defrag(ni, m, hdrspace);
502			if (m == NULL) {
503				/* Fragment dropped or frame not complete yet */
504				goto out;
505			}
506		}
507		wh = NULL;		/* no longer valid, catch any uses */
508
509		/*
510		 * Next strip any MSDU crypto bits.
511		 */
512		if (key != NULL && !ieee80211_crypto_demic(vap, key, m, 0)) {
513			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
514			    ni->ni_macaddr, "data", "%s", "demic error");
515			vap->iv_stats.is_rx_demicfail++;
516			IEEE80211_NODE_STAT(ni, rx_demicfail);
517			goto out;
518		}
519
520		/* copy to listener after decrypt */
521		if (bpf_peers_present(vap->iv_rawbpf))
522			bpf_mtap(vap->iv_rawbpf, m);
523		need_tap = 0;
524
525		/*
526		 * Finally, strip the 802.11 header.
527		 */
528		m = ieee80211_decap(vap, m, hdrspace);
529		if (m == NULL) {
530			/* XXX mask bit to check for both */
531			/* don't count Null data frames as errors */
532			if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
533			    subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
534				goto out;
535			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
536			    ni->ni_macaddr, "data", "%s", "decap error");
537			vap->iv_stats.is_rx_decap++;
538			IEEE80211_NODE_STAT(ni, rx_decap);
539			goto err;
540		}
541		eh = mtod(m, struct ether_header *);
542		if (!ieee80211_node_is_authorized(ni)) {
543			/*
544			 * Deny any non-PAE frames received prior to
545			 * authorization.  For open/shared-key
546			 * authentication the port is mark authorized
547			 * after authentication completes.  For 802.1x
548			 * the port is not marked authorized by the
549			 * authenticator until the handshake has completed.
550			 */
551			if (eh->ether_type != htons(ETHERTYPE_PAE)) {
552				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
553				    eh->ether_shost, "data",
554				    "unauthorized port: ether type 0x%x len %u",
555				    eh->ether_type, m->m_pkthdr.len);
556				vap->iv_stats.is_rx_unauth++;
557				IEEE80211_NODE_STAT(ni, rx_unauth);
558				goto err;
559			}
560		} else {
561			/*
562			 * When denying unencrypted frames, discard
563			 * any non-PAE frames received without encryption.
564			 */
565			if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
566			    (key == NULL && (m->m_flags & M_WEP) == 0) &&
567			    eh->ether_type != htons(ETHERTYPE_PAE)) {
568				/*
569				 * Drop unencrypted frames.
570				 */
571				vap->iv_stats.is_rx_unencrypted++;
572				IEEE80211_NODE_STAT(ni, rx_unencrypted);
573				goto out;
574			}
575		}
576		/* XXX require HT? */
577		if (qos & IEEE80211_QOS_AMSDU) {
578			m = ieee80211_decap_amsdu(ni, m);
579			if (m == NULL)
580				return IEEE80211_FC0_TYPE_DATA;
581		} else if (IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_FF) &&
582#define	FF_LLC_SIZE	(sizeof(struct ether_header) + sizeof(struct llc))
583		    m->m_pkthdr.len >= 3*FF_LLC_SIZE) {
584			struct llc *llc;
585
586			/*
587			 * Check for fast-frame tunnel encapsulation.
588			 */
589			if (m->m_len < FF_LLC_SIZE &&
590			    (m = m_pullup(m, FF_LLC_SIZE)) == NULL) {
591				IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
592				    ni->ni_macaddr, "fast-frame",
593				    "%s", "m_pullup(llc) failed");
594				vap->iv_stats.is_rx_tooshort++;
595				return IEEE80211_FC0_TYPE_DATA;
596			}
597			llc = (struct llc *)(mtod(m, uint8_t *) +
598				sizeof(struct ether_header));
599			if (llc->llc_snap.ether_type == htons(ATH_FF_ETH_TYPE)) {
600				m_adj(m, FF_LLC_SIZE);
601				m = ieee80211_decap_fastframe(ni, m);
602				if (m == NULL)
603					return IEEE80211_FC0_TYPE_DATA;
604			}
605		}
606#undef FF_LLC_SIZE
607		if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
608			ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
609		else
610			ieee80211_deliver_data(vap, ni, m);
611		return IEEE80211_FC0_TYPE_DATA;
612
613	case IEEE80211_FC0_TYPE_MGT:
614		vap->iv_stats.is_rx_mgmt++;
615		IEEE80211_NODE_STAT(ni, rx_mgmt);
616		if (dir != IEEE80211_FC1_DIR_NODS) {
617			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
618			    wh, "data", "incorrect dir 0x%x", dir);
619			vap->iv_stats.is_rx_wrongdir++;
620			goto err;
621		}
622		if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
623			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
624			    ni->ni_macaddr, "mgt", "too short: len %u",
625			    m->m_pkthdr.len);
626			vap->iv_stats.is_rx_tooshort++;
627			goto out;
628		}
629#ifdef IEEE80211_DEBUG
630		if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
631		    ieee80211_msg_dumppkts(vap)) {
632			if_printf(ifp, "received %s from %s rssi %d\n",
633			    ieee80211_mgt_subtype_name[subtype >>
634				IEEE80211_FC0_SUBTYPE_SHIFT],
635			    ether_sprintf(wh->i_addr2), rssi);
636		}
637#endif
638		if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
639			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
640			    wh, NULL, "%s", "WEP set but not permitted");
641			vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
642			goto out;
643		}
644		if (bpf_peers_present(vap->iv_rawbpf))
645			bpf_mtap(vap->iv_rawbpf, m);
646		vap->iv_recv_mgmt(ni, m, subtype, rssi, noise, rstamp);
647		m_freem(m);
648		return IEEE80211_FC0_TYPE_MGT;
649
650	case IEEE80211_FC0_TYPE_CTL:
651		vap->iv_stats.is_rx_ctl++;
652		IEEE80211_NODE_STAT(ni, rx_ctrl);
653		goto out;
654	default:
655		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
656		    wh, "bad", "frame type 0x%x", type);
657		/* should not come here */
658		break;
659	}
660err:
661	ifp->if_ierrors++;
662out:
663	if (m != NULL) {
664		if (bpf_peers_present(vap->iv_rawbpf) && need_tap)
665			bpf_mtap(vap->iv_rawbpf, m);
666		m_freem(m);
667	}
668	return type;
669#undef SEQ_LEQ
670}
671
672static int
673is11bclient(const uint8_t *rates, const uint8_t *xrates)
674{
675	static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
676	int i;
677
678	/* NB: the 11b clients we care about will not have xrates */
679	if (xrates != NULL || rates == NULL)
680		return 0;
681	for (i = 0; i < rates[1]; i++) {
682		int r = rates[2+i] & IEEE80211_RATE_VAL;
683		if (r > 2*11 || ((1<<r) & brates) == 0)
684			return 0;
685	}
686	return 1;
687}
688
689static void
690adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
691	int subtype, int rssi, int noise, uint32_t rstamp)
692{
693	struct ieee80211vap *vap = ni->ni_vap;
694	struct ieee80211com *ic = ni->ni_ic;
695	struct ieee80211_frame *wh;
696	uint8_t *frm, *efrm, *sfrm;
697	uint8_t *ssid, *rates, *xrates;
698
699	wh = mtod(m0, struct ieee80211_frame *);
700	frm = (uint8_t *)&wh[1];
701	efrm = mtod(m0, uint8_t *) + m0->m_len;
702	switch (subtype) {
703	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
704	case IEEE80211_FC0_SUBTYPE_BEACON: {
705		struct ieee80211_scanparams scan;
706		/*
707		 * We process beacon/probe response
708		 * frames to discover neighbors.
709		 */
710		if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
711			return;
712		/*
713		 * Count frame now that we know it's to be processed.
714		 */
715		if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
716			vap->iv_stats.is_rx_beacon++;		/* XXX remove */
717			IEEE80211_NODE_STAT(ni, rx_beacons);
718		} else
719			IEEE80211_NODE_STAT(ni, rx_proberesp);
720		/*
721		 * If scanning, just pass information to the scan module.
722		 */
723		if (ic->ic_flags & IEEE80211_F_SCAN) {
724			if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
725				/*
726				 * Actively scanning a channel marked passive;
727				 * send a probe request now that we know there
728				 * is 802.11 traffic present.
729				 *
730				 * XXX check if the beacon we recv'd gives
731				 * us what we need and suppress the probe req
732				 */
733				ieee80211_probe_curchan(vap, 1);
734				ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
735			}
736			ieee80211_add_scan(vap, &scan, wh,
737				subtype, rssi, noise, rstamp);
738			return;
739		}
740		if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
741			if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
742				/*
743				 * Create a new entry in the neighbor table.
744				 */
745				ni = ieee80211_add_neighbor(vap, wh, &scan);
746			} else if (ni->ni_capinfo == 0) {
747				/*
748				 * Update faked node created on transmit.
749				 * Note this also updates the tsf.
750				 */
751				ieee80211_init_neighbor(ni, wh, &scan);
752			} else {
753				/*
754				 * Record tsf for potential resync.
755				 */
756				memcpy(ni->ni_tstamp.data, scan.tstamp,
757					sizeof(ni->ni_tstamp));
758			}
759			if (ni != NULL) {
760				IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
761				ni->ni_noise = noise;
762				ni->ni_rstamp = rstamp;
763			}
764		}
765		break;
766	}
767
768	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
769		if (vap->iv_state != IEEE80211_S_RUN) {
770			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
771			    wh, NULL, "wrong state %s",
772			    ieee80211_state_name[vap->iv_state]);
773			vap->iv_stats.is_rx_mgtdiscard++;
774			return;
775		}
776		if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
777			/* frame must be directed */
778			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
779			    wh, NULL, "%s", "not unicast");
780			vap->iv_stats.is_rx_mgtdiscard++;	/* XXX stat */
781			return;
782		}
783
784		/*
785		 * prreq frame format
786		 *	[tlv] ssid
787		 *	[tlv] supported rates
788		 *	[tlv] extended supported rates
789		 */
790		ssid = rates = xrates = NULL;
791		sfrm = frm;
792		while (efrm - frm > 1) {
793			IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
794			switch (*frm) {
795			case IEEE80211_ELEMID_SSID:
796				ssid = frm;
797				break;
798			case IEEE80211_ELEMID_RATES:
799				rates = frm;
800				break;
801			case IEEE80211_ELEMID_XRATES:
802				xrates = frm;
803				break;
804			}
805			frm += frm[1] + 2;
806		}
807		IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
808		if (xrates != NULL)
809			IEEE80211_VERIFY_ELEMENT(xrates,
810				IEEE80211_RATE_MAXSIZE - rates[1], return);
811		IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
812		IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
813		if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
814			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
815			    wh, NULL,
816			    "%s", "no ssid with ssid suppression enabled");
817			vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
818			return;
819		}
820
821		/* XXX find a better class or define it's own */
822		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
823		    "%s", "recv probe req");
824		/*
825		 * Some legacy 11b clients cannot hack a complete
826		 * probe response frame.  When the request includes
827		 * only a bare-bones rate set, communicate this to
828		 * the transmit side.
829		 */
830		ieee80211_send_proberesp(vap, wh->i_addr2,
831		    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
832		break;
833
834	case IEEE80211_FC0_SUBTYPE_ACTION: {
835		const struct ieee80211_action *ia;
836
837		if (vap->iv_state != IEEE80211_S_RUN) {
838			IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
839			    wh, NULL, "wrong state %s",
840			    ieee80211_state_name[vap->iv_state]);
841			vap->iv_stats.is_rx_mgtdiscard++;
842			return;
843		}
844		/*
845		 * action frame format:
846		 *	[1] category
847		 *	[1] action
848		 *	[tlv] parameters
849		 */
850		IEEE80211_VERIFY_LENGTH(efrm - frm,
851			sizeof(struct ieee80211_action), return);
852		ia = (const struct ieee80211_action *) frm;
853
854		vap->iv_stats.is_rx_action++;
855		IEEE80211_NODE_STAT(ni, rx_action);
856
857		/* verify frame payloads but defer processing */
858		/* XXX maybe push this to method */
859		switch (ia->ia_category) {
860		case IEEE80211_ACTION_CAT_BA:
861			switch (ia->ia_action) {
862			case IEEE80211_ACTION_BA_ADDBA_REQUEST:
863				IEEE80211_VERIFY_LENGTH(efrm - frm,
864				    sizeof(struct ieee80211_action_ba_addbarequest),
865				    return);
866				break;
867			case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
868				IEEE80211_VERIFY_LENGTH(efrm - frm,
869				    sizeof(struct ieee80211_action_ba_addbaresponse),
870				    return);
871				break;
872			case IEEE80211_ACTION_BA_DELBA:
873				IEEE80211_VERIFY_LENGTH(efrm - frm,
874				    sizeof(struct ieee80211_action_ba_delba),
875				    return);
876				break;
877			}
878			break;
879		case IEEE80211_ACTION_CAT_HT:
880			switch (ia->ia_action) {
881			case IEEE80211_ACTION_HT_TXCHWIDTH:
882				IEEE80211_VERIFY_LENGTH(efrm - frm,
883				    sizeof(struct ieee80211_action_ht_txchwidth),
884				    return);
885				break;
886			}
887			break;
888		}
889		ic->ic_recv_action(ni, frm, efrm);
890		break;
891	}
892
893	case IEEE80211_FC0_SUBTYPE_AUTH:
894	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
895	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
896	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
897	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
898	case IEEE80211_FC0_SUBTYPE_DEAUTH:
899	case IEEE80211_FC0_SUBTYPE_DISASSOC:
900		IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
901		     wh, NULL, "%s", "not handled");
902		vap->iv_stats.is_rx_mgtdiscard++;
903		return;
904
905	default:
906		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
907		     wh, "mgt", "subtype 0x%x not handled", subtype);
908		vap->iv_stats.is_rx_badsubtype++;
909		break;
910	}
911}
912#undef IEEE80211_VERIFY_LENGTH
913#undef IEEE80211_VERIFY_ELEMENT
914
915static void
916ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
917	int subtype, int rssi, int noise, uint32_t rstamp)
918{
919	struct ieee80211vap *vap = ni->ni_vap;
920	struct ieee80211com *ic = ni->ni_ic;
921
922	/*
923	 * Process management frames when scanning; useful for doing
924	 * a site-survey.
925	 */
926	if (ic->ic_flags & IEEE80211_F_SCAN)
927		adhoc_recv_mgmt(ni, m0, subtype, rssi, noise, rstamp);
928	else
929		vap->iv_stats.is_rx_mgtdiscard++;
930}
931