ieee80211_proto.c revision 121172 
1/*-
2 * Copyright (c) 2001 Atsushi Onoe
3 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * Alternatively, this software may be distributed under the terms of the
18 * GNU General Public License ("GPL") version 2 as published by the Free
19 * Software Foundation.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_proto.c 121172 2003-10-17 21:41:52Z sam $");
35
36/*
37 * IEEE 802.11 protocol support.
38 */
39
40#include "opt_inet.h"
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/mbuf.h>
45#include <sys/malloc.h>
46#include <sys/kernel.h>
47#include <sys/socket.h>
48#include <sys/sockio.h>
49#include <sys/endian.h>
50#include <sys/errno.h>
51#include <sys/bus.h>
52#include <sys/proc.h>
53#include <sys/sysctl.h>
54
55#include <machine/atomic.h>
56
57#include <net/if.h>
58#include <net/if_dl.h>
59#include <net/if_media.h>
60#include <net/if_arp.h>
61#include <net/ethernet.h>
62#include <net/if_llc.h>
63
64#include <net80211/ieee80211_var.h>
65
66#include <net/bpf.h>
67
68#ifdef INET
69#include <netinet/in.h>
70#include <netinet/if_ether.h>
71#endif
72
73#define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
74
75const char *ieee80211_mgt_subtype_name[] = {
76	"assoc_req",	"assoc_resp",	"reassoc_req",	"reassoc_resp",
77	"probe_req",	"probe_resp",	"reserved#6",	"reserved#7",
78	"beacon",	"atim",		"disassoc",	"auth",
79	"deauth",	"reserved#13",	"reserved#14",	"reserved#15"
80};
81const char *ieee80211_state_name[IEEE80211_S_MAX] = {
82	"INIT",		/* IEEE80211_S_INIT */
83	"SCAN",		/* IEEE80211_S_SCAN */
84	"AUTH",		/* IEEE80211_S_AUTH */
85	"ASSOC",	/* IEEE80211_S_ASSOC */
86	"RUN"		/* IEEE80211_S_RUN */
87};
88
89static int ieee80211_newstate(struct ieee80211com *, enum ieee80211_state, int);
90
91void
92ieee80211_proto_attach(struct ifnet *ifp)
93{
94	struct ieee80211com *ic = (void *)ifp;
95
96	ifp->if_hdrlen = sizeof(struct ieee80211_frame);
97
98#ifdef notdef
99	ic->ic_rtsthreshold = IEEE80211_RTS_DEFAULT;
100#else
101	ic->ic_rtsthreshold = IEEE80211_RTS_MAX;
102#endif
103	ic->ic_fragthreshold = 2346;		/* XXX not used yet */
104	ic->ic_fixed_rate = -1;			/* no fixed rate */
105
106	mtx_init(&ic->ic_mgtq.ifq_mtx, ifp->if_name, "mgmt send q", MTX_DEF);
107
108	/* protocol state change handler */
109	ic->ic_newstate = ieee80211_newstate;
110
111	/* initialize management frame handlers */
112	ic->ic_recv_mgmt = ieee80211_recv_mgmt;
113	ic->ic_send_mgmt = ieee80211_send_mgmt;
114}
115
116void
117ieee80211_proto_detach(struct ifnet *ifp)
118{
119	struct ieee80211com *ic = (void *)ifp;
120
121	IF_DRAIN(&ic->ic_mgtq);
122	mtx_destroy(&ic->ic_mgtq.ifq_mtx);
123}
124
125void
126ieee80211_print_essid(u_int8_t *essid, int len)
127{
128	int i;
129	u_int8_t *p;
130
131	if (len > IEEE80211_NWID_LEN)
132		len = IEEE80211_NWID_LEN;
133	/* determine printable or not */
134	for (i = 0, p = essid; i < len; i++, p++) {
135		if (*p < ' ' || *p > 0x7e)
136			break;
137	}
138	if (i == len) {
139		printf("\"");
140		for (i = 0, p = essid; i < len; i++, p++)
141			printf("%c", *p);
142		printf("\"");
143	} else {
144		printf("0x");
145		for (i = 0, p = essid; i < len; i++, p++)
146			printf("%02x", *p);
147	}
148}
149
150void
151ieee80211_dump_pkt(u_int8_t *buf, int len, int rate, int rssi)
152{
153	struct ieee80211_frame *wh;
154	int i;
155
156	wh = (struct ieee80211_frame *)buf;
157	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
158	case IEEE80211_FC1_DIR_NODS:
159		printf("NODS %s", ether_sprintf(wh->i_addr2));
160		printf("->%s", ether_sprintf(wh->i_addr1));
161		printf("(%s)", ether_sprintf(wh->i_addr3));
162		break;
163	case IEEE80211_FC1_DIR_TODS:
164		printf("TODS %s", ether_sprintf(wh->i_addr2));
165		printf("->%s", ether_sprintf(wh->i_addr3));
166		printf("(%s)", ether_sprintf(wh->i_addr1));
167		break;
168	case IEEE80211_FC1_DIR_FROMDS:
169		printf("FRDS %s", ether_sprintf(wh->i_addr3));
170		printf("->%s", ether_sprintf(wh->i_addr1));
171		printf("(%s)", ether_sprintf(wh->i_addr2));
172		break;
173	case IEEE80211_FC1_DIR_DSTODS:
174		printf("DSDS %s", ether_sprintf((u_int8_t *)&wh[1]));
175		printf("->%s", ether_sprintf(wh->i_addr3));
176		printf("(%s", ether_sprintf(wh->i_addr2));
177		printf("->%s)", ether_sprintf(wh->i_addr1));
178		break;
179	}
180	switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
181	case IEEE80211_FC0_TYPE_DATA:
182		printf(" data");
183		break;
184	case IEEE80211_FC0_TYPE_MGT:
185		printf(" %s", ieee80211_mgt_subtype_name[
186		    (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK)
187		    >> IEEE80211_FC0_SUBTYPE_SHIFT]);
188		break;
189	default:
190		printf(" type#%d", wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK);
191		break;
192	}
193	if (wh->i_fc[1] & IEEE80211_FC1_WEP)
194		printf(" WEP");
195	if (rate >= 0)
196		printf(" %dM", rate / 2);
197	if (rssi >= 0)
198		printf(" +%d", rssi);
199	printf("\n");
200	if (len > 0) {
201		for (i = 0; i < len; i++) {
202			if ((i & 1) == 0)
203				printf(" ");
204			printf("%02x", buf[i]);
205		}
206		printf("\n");
207	}
208}
209
210int
211ieee80211_fix_rate(struct ieee80211com *ic, struct ieee80211_node *ni, int flags)
212{
213#define	RV(v)	((v) & IEEE80211_RATE_VAL)
214	int i, j, ignore, error;
215	int okrate, badrate;
216	struct ieee80211_rateset *srs, *nrs;
217	u_int8_t r;
218
219	error = 0;
220	okrate = badrate = 0;
221	srs = &ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
222	nrs = &ni->ni_rates;
223	for (i = 0; i < nrs->rs_nrates; ) {
224		ignore = 0;
225		if (flags & IEEE80211_F_DOSORT) {
226			/*
227			 * Sort rates.
228			 */
229			for (j = i + 1; j < nrs->rs_nrates; j++) {
230				if (RV(nrs->rs_rates[i]) > RV(nrs->rs_rates[j])) {
231					r = nrs->rs_rates[i];
232					nrs->rs_rates[i] = nrs->rs_rates[j];
233					nrs->rs_rates[j] = r;
234				}
235			}
236		}
237		r = nrs->rs_rates[i] & IEEE80211_RATE_VAL;
238		badrate = r;
239		if (flags & IEEE80211_F_DOFRATE) {
240			/*
241			 * Apply fixed rate constraint.  Note that we do
242			 * not apply the constraint to basic rates as
243			 * otherwise we may not be able to associate if
244			 * the rate set we submit to the AP is invalid
245			 * (e.g. fix rate at 36Mb/s which is not a basic
246			 * rate for 11a operation).
247			 */
248			if ((nrs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0 &&
249			    ic->ic_fixed_rate >= 0 &&
250			    r != RV(srs->rs_rates[ic->ic_fixed_rate]))
251				ignore++;
252		}
253		if (flags & IEEE80211_F_DONEGO) {
254			/*
255			 * Check against supported rates.
256			 */
257			for (j = 0; j < srs->rs_nrates; j++) {
258				if (r == RV(srs->rs_rates[j]))
259					break;
260			}
261			if (j == srs->rs_nrates) {
262				/*
263				 * A rate in the node's rate set is not
264				 * supported.  If this is a basic rate and we
265				 * are operating as an AP then this is an error.
266				 * Otherwise we just discard/ignore the rate.
267				 * Note that this is important for 11b stations
268				 * when they want to associate with an 11g AP.
269				 */
270				if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
271				    (nrs->rs_rates[i] & IEEE80211_RATE_BASIC))
272					error++;
273				ignore++;
274			}
275		}
276		if (flags & IEEE80211_F_DODEL) {
277			/*
278			 * Delete unacceptable rates.
279			 */
280			if (ignore) {
281				nrs->rs_nrates--;
282				for (j = i; j < nrs->rs_nrates; j++)
283					nrs->rs_rates[j] = nrs->rs_rates[j + 1];
284				nrs->rs_rates[j] = 0;
285				continue;
286			}
287		}
288		if (!ignore)
289			okrate = nrs->rs_rates[i];
290		i++;
291	}
292	if (okrate == 0 || error != 0)
293		return badrate | IEEE80211_RATE_BASIC;
294	else
295		return RV(okrate);
296#undef RV
297}
298
299static int
300ieee80211_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int mgt)
301{
302	struct ifnet *ifp = &ic->ic_if;
303	struct ieee80211_node *ni;
304	enum ieee80211_state ostate;
305
306	ostate = ic->ic_state;
307	IEEE80211_DPRINTF(("%s: %s -> %s\n", __func__,
308		ieee80211_state_name[ostate], ieee80211_state_name[nstate]));
309	ic->ic_state = nstate;			/* state transition */
310	ni = ic->ic_bss;			/* NB: no reference held */
311	switch (nstate) {
312	case IEEE80211_S_INIT:
313		switch (ostate) {
314		case IEEE80211_S_INIT:
315			break;
316		case IEEE80211_S_RUN:
317			switch (ic->ic_opmode) {
318			case IEEE80211_M_STA:
319				IEEE80211_SEND_MGMT(ic, ni,
320				    IEEE80211_FC0_SUBTYPE_DISASSOC,
321				    IEEE80211_REASON_ASSOC_LEAVE);
322				break;
323			case IEEE80211_M_HOSTAP:
324				IEEE80211_NODE_LOCK(ic);
325				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
326					if (ni->ni_associd == 0)
327						continue;
328					IEEE80211_SEND_MGMT(ic, ni,
329					    IEEE80211_FC0_SUBTYPE_DISASSOC,
330					    IEEE80211_REASON_ASSOC_LEAVE);
331				}
332				IEEE80211_NODE_UNLOCK(ic);
333				break;
334			default:
335				break;
336			}
337			/* FALLTHRU */
338		case IEEE80211_S_ASSOC:
339			switch (ic->ic_opmode) {
340			case IEEE80211_M_STA:
341				IEEE80211_SEND_MGMT(ic, ni,
342				    IEEE80211_FC0_SUBTYPE_DEAUTH,
343				    IEEE80211_REASON_AUTH_LEAVE);
344				break;
345			case IEEE80211_M_HOSTAP:
346				IEEE80211_NODE_LOCK(ic);
347				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
348					IEEE80211_SEND_MGMT(ic, ni,
349					    IEEE80211_FC0_SUBTYPE_DEAUTH,
350					    IEEE80211_REASON_AUTH_LEAVE);
351				}
352				IEEE80211_NODE_UNLOCK(ic);
353				break;
354			default:
355				break;
356			}
357			/* FALLTHRU */
358		case IEEE80211_S_AUTH:
359		case IEEE80211_S_SCAN:
360			ic->ic_mgt_timer = 0;
361			IF_DRAIN(&ic->ic_mgtq);
362			if (ic->ic_wep_ctx != NULL) {
363				free(ic->ic_wep_ctx, M_DEVBUF);
364				ic->ic_wep_ctx = NULL;
365			}
366			ieee80211_free_allnodes(ic);
367			break;
368		}
369		break;
370	case IEEE80211_S_SCAN:
371		ic->ic_flags &= ~IEEE80211_F_SIBSS;
372		/* initialize bss for probe request */
373		IEEE80211_ADDR_COPY(ni->ni_macaddr, ifp->if_broadcastaddr);
374		IEEE80211_ADDR_COPY(ni->ni_bssid, ifp->if_broadcastaddr);
375		ni->ni_rates = ic->ic_sup_rates[
376			ieee80211_chan2mode(ic, ni->ni_chan)];
377		ni->ni_associd = 0;
378		ni->ni_rstamp = 0;
379		switch (ostate) {
380		case IEEE80211_S_INIT:
381			if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
382			    ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
383				/*
384				 * AP operation and we already have a channel;
385				 * bypass the scan and startup immediately.
386				 */
387				ieee80211_create_ibss(ic, ic->ic_des_chan);
388			} else {
389				ieee80211_begin_scan(ifp);
390			}
391			break;
392		case IEEE80211_S_SCAN:
393			/* scan next */
394			if (ic->ic_flags & IEEE80211_F_ASCAN) {
395				IEEE80211_SEND_MGMT(ic, ni,
396				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
397			}
398			break;
399		case IEEE80211_S_RUN:
400			/* beacon miss */
401			if (ifp->if_flags & IFF_DEBUG) {
402				/* XXX bssid clobbered above */
403				if_printf(ifp, "no recent beacons from %s;"
404				    " rescanning\n",
405				    ether_sprintf(ic->ic_bss->ni_bssid));
406			}
407			ieee80211_free_allnodes(ic);
408			/* FALLTHRU */
409		case IEEE80211_S_AUTH:
410		case IEEE80211_S_ASSOC:
411			/* timeout restart scan */
412			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
413			if (ni != NULL) {
414				ni->ni_fails++;
415				ieee80211_unref_node(&ni);
416			}
417			ieee80211_begin_scan(ifp);
418			break;
419		}
420		break;
421	case IEEE80211_S_AUTH:
422		switch (ostate) {
423		case IEEE80211_S_INIT:
424			IEEE80211_DPRINTF(("%s: invalid transition\n",
425				__func__));
426			break;
427		case IEEE80211_S_SCAN:
428			IEEE80211_SEND_MGMT(ic, ni,
429			    IEEE80211_FC0_SUBTYPE_AUTH, 1);
430			break;
431		case IEEE80211_S_AUTH:
432		case IEEE80211_S_ASSOC:
433			switch (mgt) {
434			case IEEE80211_FC0_SUBTYPE_AUTH:
435				/* ??? */
436				IEEE80211_SEND_MGMT(ic, ni,
437				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
438				break;
439			case IEEE80211_FC0_SUBTYPE_DEAUTH:
440				/* ignore and retry scan on timeout */
441				break;
442			}
443			break;
444		case IEEE80211_S_RUN:
445			switch (mgt) {
446			case IEEE80211_FC0_SUBTYPE_AUTH:
447				IEEE80211_SEND_MGMT(ic, ni,
448				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
449				ic->ic_state = ostate;	/* stay RUN */
450				break;
451			case IEEE80211_FC0_SUBTYPE_DEAUTH:
452				/* try to reauth */
453				IEEE80211_SEND_MGMT(ic, ni,
454				    IEEE80211_FC0_SUBTYPE_AUTH, 1);
455				break;
456			}
457			break;
458		}
459		break;
460	case IEEE80211_S_ASSOC:
461		switch (ostate) {
462		case IEEE80211_S_INIT:
463		case IEEE80211_S_SCAN:
464		case IEEE80211_S_ASSOC:
465			IEEE80211_DPRINTF(("%s: invalid transition\n",
466				__func__));
467			break;
468		case IEEE80211_S_AUTH:
469			IEEE80211_SEND_MGMT(ic, ni,
470			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 0);
471			break;
472		case IEEE80211_S_RUN:
473			IEEE80211_SEND_MGMT(ic, ni,
474			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 1);
475			break;
476		}
477		break;
478	case IEEE80211_S_RUN:
479		switch (ostate) {
480		case IEEE80211_S_INIT:
481		case IEEE80211_S_AUTH:
482		case IEEE80211_S_RUN:
483			IEEE80211_DPRINTF(("%s: invalid transition\n",
484				__func__));
485			break;
486		case IEEE80211_S_SCAN:		/* adhoc/hostap mode */
487		case IEEE80211_S_ASSOC:		/* infra mode */
488			KASSERT(ni->ni_txrate < ni->ni_rates.rs_nrates,
489				("%s: bogus xmit rate %u setup\n", __func__,
490					ni->ni_txrate));
491			if (ifp->if_flags & IFF_DEBUG) {
492				if_printf(ifp, " ");
493				if (ic->ic_opmode == IEEE80211_M_STA)
494					printf("associated ");
495				else
496					printf("synchronized ");
497				printf("with %s ssid ",
498				    ether_sprintf(ni->ni_bssid));
499				ieee80211_print_essid(ic->ic_bss->ni_essid,
500				    ni->ni_esslen);
501				printf(" channel %d start %uMb\n",
502					ieee80211_chan2ieee(ic, ni->ni_chan),
503					IEEE80211_RATE2MBS(ni->ni_rates.rs_rates[ni->ni_txrate]));
504			}
505			ic->ic_mgt_timer = 0;
506			(*ifp->if_start)(ifp);
507			break;
508		}
509		break;
510	}
511	return 0;
512}
513