xref: /netbsd-src/sys/net80211/ieee80211_proto.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: ieee80211_proto.c,v 1.17 2004/09/07 01:07:40 enami 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_proto.c,v 1.8 2004/04/02 20:22:25 sam Exp $");
37 #else
38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_proto.c,v 1.17 2004/09/07 01:07:40 enami Exp $");
39 #endif
40 
41 /*
42  * IEEE 802.11 protocol support.
43  */
44 
45 #include "opt_inet.h"
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 #include <net/bpf.h>
81 
82 #ifdef INET
83 #include <netinet/in.h>
84 #ifdef __FreeBSD__
85 #include <netinet/if_ether.h>
86 #else
87 #include <net/if_ether.h>
88 #endif
89 #endif
90 
91 #include <net/route.h>
92 
93 #define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
94 
95 const char *ieee80211_mgt_subtype_name[] = {
96 	"assoc_req",	"assoc_resp",	"reassoc_req",	"reassoc_resp",
97 	"probe_req",	"probe_resp",	"reserved#6",	"reserved#7",
98 	"beacon",	"atim",		"disassoc",	"auth",
99 	"deauth",	"reserved#13",	"reserved#14",	"reserved#15"
100 };
101 const char *ieee80211_state_name[IEEE80211_S_MAX] = {
102 	"INIT",		/* IEEE80211_S_INIT */
103 	"SCAN",		/* IEEE80211_S_SCAN */
104 	"AUTH",		/* IEEE80211_S_AUTH */
105 	"ASSOC",	/* IEEE80211_S_ASSOC */
106 	"RUN"		/* IEEE80211_S_RUN */
107 };
108 
109 static int ieee80211_newstate(struct ieee80211com *, enum ieee80211_state, int);
110 
111 void
112 ieee80211_proto_attach(struct ifnet *ifp)
113 {
114 	struct ieee80211com *ic = (void *)ifp;
115 
116 	ifp->if_hdrlen = sizeof(struct ieee80211_frame);
117 
118 #ifdef notdef
119 	ic->ic_rtsthreshold = IEEE80211_RTS_DEFAULT;
120 #else
121 	ic->ic_rtsthreshold = IEEE80211_RTS_MAX;
122 #endif
123 	ic->ic_fragthreshold = 2346;		/* XXX not used yet */
124 	ic->ic_fixed_rate = -1;			/* no fixed rate */
125 	ic->ic_protmode = IEEE80211_PROT_CTSONLY;
126 
127 #ifdef __FreeBSD__
128 	mtx_init(&ic->ic_mgtq.ifq_mtx, ifp->if_xname, "mgmt send q", MTX_DEF);
129 #endif
130 
131 	/* protocol state change handler */
132 	ic->ic_newstate = ieee80211_newstate;
133 
134 	/* initialize management frame handlers */
135 	ic->ic_recv_mgmt = ieee80211_recv_mgmt;
136 	ic->ic_send_mgmt = ieee80211_send_mgmt;
137 }
138 
139 void
140 ieee80211_proto_detach(struct ifnet *ifp)
141 {
142 	struct ieee80211com *ic = (void *)ifp;
143 
144 #ifdef __FreeBSD__
145 	IF_DRAIN(&ic->ic_mgtq);
146 	mtx_destroy(&ic->ic_mgtq.ifq_mtx);
147 #else
148 	IF_PURGE(&ic->ic_mgtq);
149 	IF_PURGE(&ic->ic_pwrsaveq);
150 #endif
151 }
152 
153 void
154 ieee80211_print_essid(u_int8_t *essid, int len)
155 {
156 	int i;
157 	u_int8_t *p;
158 
159 	if (len > IEEE80211_NWID_LEN)
160 		len = IEEE80211_NWID_LEN;
161 	/* determine printable or not */
162 	for (i = 0, p = essid; i < len; i++, p++) {
163 		if (*p < ' ' || *p > 0x7e)
164 			break;
165 	}
166 	if (i == len) {
167 		printf("\"");
168 		for (i = 0, p = essid; i < len; i++, p++)
169 			printf("%c", *p);
170 		printf("\"");
171 	} else {
172 		printf("0x");
173 		for (i = 0, p = essid; i < len; i++, p++)
174 			printf("%02x", *p);
175 	}
176 }
177 
178 void
179 ieee80211_dump_pkt(u_int8_t *buf, int len, int rate, int rssi)
180 {
181 	struct ieee80211_frame *wh;
182 	int i;
183 
184 	wh = (struct ieee80211_frame *)buf;
185 	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
186 	case IEEE80211_FC1_DIR_NODS:
187 		printf("NODS %s", ether_sprintf(wh->i_addr2));
188 		printf("->%s", ether_sprintf(wh->i_addr1));
189 		printf("(%s)", ether_sprintf(wh->i_addr3));
190 		break;
191 	case IEEE80211_FC1_DIR_TODS:
192 		printf("TODS %s", ether_sprintf(wh->i_addr2));
193 		printf("->%s", ether_sprintf(wh->i_addr3));
194 		printf("(%s)", ether_sprintf(wh->i_addr1));
195 		break;
196 	case IEEE80211_FC1_DIR_FROMDS:
197 		printf("FRDS %s", ether_sprintf(wh->i_addr3));
198 		printf("->%s", ether_sprintf(wh->i_addr1));
199 		printf("(%s)", ether_sprintf(wh->i_addr2));
200 		break;
201 	case IEEE80211_FC1_DIR_DSTODS:
202 		printf("DSDS %s", ether_sprintf((u_int8_t *)&wh[1]));
203 		printf("->%s", ether_sprintf(wh->i_addr3));
204 		printf("(%s", ether_sprintf(wh->i_addr2));
205 		printf("->%s)", ether_sprintf(wh->i_addr1));
206 		break;
207 	}
208 	switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
209 	case IEEE80211_FC0_TYPE_DATA:
210 		printf(" data");
211 		break;
212 	case IEEE80211_FC0_TYPE_MGT:
213 		printf(" %s", ieee80211_mgt_subtype_name[
214 		    (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK)
215 		    >> IEEE80211_FC0_SUBTYPE_SHIFT]);
216 		break;
217 	default:
218 		printf(" type#%d", wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK);
219 		break;
220 	}
221 	if (wh->i_fc[1] & IEEE80211_FC1_WEP)
222 		printf(" WEP");
223 	if (rate >= 0)
224 		printf(" %dM", rate / 2);
225 	if (rssi >= 0)
226 		printf(" +%d", rssi);
227 	printf("\n");
228 	if (len > 0) {
229 		for (i = 0; i < len; i++) {
230 			if ((i & 1) == 0)
231 				printf(" ");
232 			printf("%02x", buf[i]);
233 		}
234 		printf("\n");
235 	}
236 }
237 
238 int
239 ieee80211_fix_rate(struct ieee80211com *ic, struct ieee80211_node *ni, int flags)
240 {
241 #define	RV(v)	((v) & IEEE80211_RATE_VAL)
242 	int i, j, ignore, error;
243 	int okrate, badrate;
244 	struct ieee80211_rateset *srs, *nrs;
245 	u_int8_t r;
246 
247 	error = 0;
248 	okrate = badrate = 0;
249 	srs = &ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
250 	nrs = &ni->ni_rates;
251 	for (i = 0; i < nrs->rs_nrates; ) {
252 		ignore = 0;
253 		if (flags & IEEE80211_F_DOSORT) {
254 			/*
255 			 * Sort rates.
256 			 */
257 			for (j = i + 1; j < nrs->rs_nrates; j++) {
258 				if (RV(nrs->rs_rates[i]) > RV(nrs->rs_rates[j])) {
259 					r = nrs->rs_rates[i];
260 					nrs->rs_rates[i] = nrs->rs_rates[j];
261 					nrs->rs_rates[j] = r;
262 				}
263 			}
264 		}
265 		r = nrs->rs_rates[i] & IEEE80211_RATE_VAL;
266 		badrate = r;
267 		if (flags & IEEE80211_F_DOFRATE) {
268 			/*
269 			 * Apply fixed rate constraint.  Note that we do
270 			 * not apply the constraint to basic rates as
271 			 * otherwise we may not be able to associate if
272 			 * the rate set we submit to the AP is invalid
273 			 * (e.g. fix rate at 36Mb/s which is not a basic
274 			 * rate for 11a operation).
275 			 */
276 			if ((nrs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0 &&
277 			    ic->ic_fixed_rate >= 0 &&
278 			    r != RV(srs->rs_rates[ic->ic_fixed_rate]))
279 				ignore++;
280 		}
281 		if (flags & IEEE80211_F_DONEGO) {
282 			/*
283 			 * Check against supported rates.
284 			 */
285 			for (j = 0; j < srs->rs_nrates; j++) {
286 				if (r == RV(srs->rs_rates[j])) {
287 					/*
288 					 * Overwrite with the supported rate
289 					 * value so any basic rate bit is set.
290 					 * This insures that response we send
291 					 * to stations have the necessary basic
292 					 * rate bit set.
293 					 */
294 					nrs->rs_rates[i] = srs->rs_rates[j];
295 					break;
296 				}
297 			}
298 			if (j == srs->rs_nrates) {
299 				/*
300 				 * A rate in the node's rate set is not
301 				 * supported.  If this is a basic rate and we
302 				 * are operating as an AP then this is an error.
303 				 * Otherwise we just discard/ignore the rate.
304 				 * Note that this is important for 11b stations
305 				 * when they want to associate with an 11g AP.
306 				 */
307 				if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
308 				    (nrs->rs_rates[i] & IEEE80211_RATE_BASIC))
309 					error++;
310 				ignore++;
311 			}
312 		}
313 		if (flags & IEEE80211_F_DODEL) {
314 			/*
315 			 * Delete unacceptable rates.
316 			 */
317 			if (ignore) {
318 				nrs->rs_nrates--;
319 				for (j = i; j < nrs->rs_nrates; j++)
320 					nrs->rs_rates[j] = nrs->rs_rates[j + 1];
321 				nrs->rs_rates[j] = 0;
322 				continue;
323 			}
324 		}
325 		if (!ignore) {
326 			okrate = nrs->rs_rates[i];
327 			ni->ni_txrate = i;
328 		}
329 		i++;
330 	}
331 	if (okrate == 0 || error != 0)
332 		return badrate | IEEE80211_RATE_BASIC;
333 	else
334 		return RV(okrate);
335 #undef RV
336 }
337 
338 static int
339 ieee80211_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int mgt)
340 {
341 	struct ifnet *ifp = &ic->ic_if;
342 	struct ieee80211_node *ni;
343 	enum ieee80211_state ostate;
344 	ieee80211_node_critsec_decl(s);
345 	int linkstate = LINK_STATE_DOWN;
346 
347 	ostate = ic->ic_state;
348 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_STATE, ("%s: %s -> %s\n", __func__,
349 		ieee80211_state_name[ostate], ieee80211_state_name[nstate]));
350 	ic->ic_state = nstate;			/* state transition */
351 	ni = ic->ic_bss;			/* NB: no reference held */
352 	switch (nstate) {
353 	case IEEE80211_S_INIT:
354 		switch (ostate) {
355 		case IEEE80211_S_INIT:
356 			break;
357 		case IEEE80211_S_RUN:
358 			switch (ic->ic_opmode) {
359 			case IEEE80211_M_STA:
360 				IEEE80211_SEND_MGMT(ic, ni,
361 				    IEEE80211_FC0_SUBTYPE_DISASSOC,
362 				    IEEE80211_REASON_ASSOC_LEAVE);
363 				break;
364 			case IEEE80211_M_HOSTAP:
365 				ieee80211_node_critsec_begin(ic, s);
366 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
367 					if (ni->ni_associd == 0)
368 						continue;
369 					IEEE80211_SEND_MGMT(ic, ni,
370 					    IEEE80211_FC0_SUBTYPE_DISASSOC,
371 					    IEEE80211_REASON_ASSOC_LEAVE);
372 				}
373 				ieee80211_node_critsec_end(ic, s);
374 				break;
375 			default:
376 				break;
377 			}
378 			/* FALLTHRU */
379 		case IEEE80211_S_ASSOC:
380 			switch (ic->ic_opmode) {
381 			case IEEE80211_M_STA:
382 				IEEE80211_SEND_MGMT(ic, ni,
383 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
384 				    IEEE80211_REASON_AUTH_LEAVE);
385 				break;
386 			case IEEE80211_M_HOSTAP:
387 				ieee80211_node_critsec_begin(ic, s);
388 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
389 					IEEE80211_SEND_MGMT(ic, ni,
390 					    IEEE80211_FC0_SUBTYPE_DEAUTH,
391 					    IEEE80211_REASON_AUTH_LEAVE);
392 				}
393 				ieee80211_node_critsec_end(ic, s);
394 				break;
395 			default:
396 				break;
397 			}
398 			/* FALLTHRU */
399 		case IEEE80211_S_AUTH:
400 		case IEEE80211_S_SCAN:
401 			ic->ic_mgt_timer = 0;
402 #ifdef __FreeBSD__
403 			IF_DRAIN(&ic->ic_mgtq);
404 #else
405 			IF_PURGE(&ic->ic_mgtq);
406 			IF_PURGE(&ic->ic_pwrsaveq);
407 #endif
408 			if (ic->ic_wep_ctx != NULL) {
409 				free(ic->ic_wep_ctx, M_DEVBUF);
410 				ic->ic_wep_ctx = NULL;
411 			}
412 			ieee80211_free_allnodes(ic);
413 			break;
414 		}
415 		break;
416 	case IEEE80211_S_SCAN:
417 		ic->ic_flags &= ~IEEE80211_F_SIBSS;
418 		/* initialize bss for probe request */
419 		IEEE80211_ADDR_COPY(ni->ni_macaddr, ifp->if_broadcastaddr);
420 		IEEE80211_ADDR_COPY(ni->ni_bssid, ifp->if_broadcastaddr);
421 		ni->ni_rates = ic->ic_sup_rates[
422 			ieee80211_chan2mode(ic, ni->ni_chan)];
423 		ni->ni_associd = 0;
424 		ni->ni_rstamp = 0;
425 		switch (ostate) {
426 		case IEEE80211_S_INIT:
427 			if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
428 			    ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
429 				/*
430 				 * AP operation and we already have a channel;
431 				 * bypass the scan and startup immediately.
432 				 */
433 				ieee80211_create_ibss(ic, ic->ic_des_chan);
434 			} else {
435 				ieee80211_begin_scan(ic);
436 			}
437 			break;
438 		case IEEE80211_S_SCAN:
439 			/* scan next */
440 			if (ic->ic_flags & IEEE80211_F_ASCAN) {
441 				IEEE80211_SEND_MGMT(ic, ni,
442 				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
443 			}
444 			break;
445 		case IEEE80211_S_RUN:
446 			/* beacon miss */
447 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_STATE,
448 				("no recent beacons from %s; rescanning\n",
449 				ether_sprintf(ic->ic_bss->ni_bssid)));
450 			/* XXX this clears the scan set */
451 			ieee80211_free_allnodes(ic);
452 			/* FALLTHRU */
453 		case IEEE80211_S_AUTH:
454 		case IEEE80211_S_ASSOC:
455 			/* timeout restart scan */
456 			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
457 			if (ni != NULL) {
458 				ni->ni_fails++;
459 			}
460 			ieee80211_begin_scan(ic);
461 			break;
462 		}
463 		break;
464 	case IEEE80211_S_AUTH:
465 		switch (ostate) {
466 		case IEEE80211_S_INIT:
467 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
468 				("%s: invalid transition\n", __func__));
469 			break;
470 		case IEEE80211_S_SCAN:
471 			IEEE80211_SEND_MGMT(ic, ni,
472 			    IEEE80211_FC0_SUBTYPE_AUTH, 1);
473 			break;
474 		case IEEE80211_S_AUTH:
475 		case IEEE80211_S_ASSOC:
476 			switch (mgt) {
477 			case IEEE80211_FC0_SUBTYPE_AUTH:
478 				/* ??? */
479 				IEEE80211_SEND_MGMT(ic, ni,
480 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
481 				break;
482 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
483 				/* ignore and retry scan on timeout */
484 				break;
485 			}
486 			break;
487 		case IEEE80211_S_RUN:
488 			switch (mgt) {
489 			case IEEE80211_FC0_SUBTYPE_AUTH:
490 				IEEE80211_SEND_MGMT(ic, ni,
491 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
492 				ic->ic_state = ostate;	/* stay RUN */
493 				break;
494 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
495 				/* try to reauth */
496 				IEEE80211_SEND_MGMT(ic, ni,
497 				    IEEE80211_FC0_SUBTYPE_AUTH, 1);
498 				break;
499 			}
500 			break;
501 		}
502 		break;
503 	case IEEE80211_S_ASSOC:
504 		switch (ostate) {
505 		case IEEE80211_S_INIT:
506 		case IEEE80211_S_SCAN:
507 		case IEEE80211_S_ASSOC:
508 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
509 				("%s: invalid transition\n", __func__));
510 			break;
511 		case IEEE80211_S_AUTH:
512 			IEEE80211_SEND_MGMT(ic, ni,
513 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 0);
514 			break;
515 		case IEEE80211_S_RUN:
516 			IEEE80211_SEND_MGMT(ic, ni,
517 			    IEEE80211_FC0_SUBTYPE_REASSOC_REQ, 0);
518 			break;
519 		}
520 		break;
521 	case IEEE80211_S_RUN:
522 		linkstate = LINK_STATE_UP;
523 		switch (ostate) {
524 		case IEEE80211_S_INIT:
525 		case IEEE80211_S_AUTH:
526 		case IEEE80211_S_RUN:
527 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
528 				("%s: invalid transition\n", __func__));
529 			break;
530 		case IEEE80211_S_SCAN:		/* adhoc/hostap mode */
531 		case IEEE80211_S_ASSOC:		/* infra mode */
532 			IASSERT(ni->ni_txrate < ni->ni_rates.rs_nrates,
533 				("%s: bogus xmit rate %u setup", __func__,
534 					ni->ni_txrate));
535 #ifdef IEEE80211_DEBUG
536 			if (ieee80211_msg_debug(ic)) {
537 				if_printf(ifp, " ");
538 				if (ic->ic_opmode == IEEE80211_M_STA)
539 					printf("associated ");
540 				else
541 					printf("synchronized ");
542 				printf("with %s ssid ",
543 				    ether_sprintf(ni->ni_bssid));
544 				ieee80211_print_essid(ic->ic_bss->ni_essid,
545 				    ni->ni_esslen);
546 				printf(" channel %d start %uMb\n",
547 					ieee80211_chan2ieee(ic, ni->ni_chan),
548 					IEEE80211_RATE2MBS(ni->ni_rates.rs_rates[ni->ni_txrate]));
549 			}
550 #endif
551 			ic->ic_mgt_timer = 0;
552 			(*ifp->if_start)(ifp);
553 			break;
554 		}
555 		break;
556 	}
557 	if (ifp->if_link_state != linkstate) {
558 		ifp->if_link_state = linkstate;
559 		s = splnet();
560 		rt_ifmsg(ifp);
561 		splx(s);
562 	}
563 	return 0;
564 }
565