xref: /freebsd/sys/net80211/ieee80211_proto.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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("$FreeBSD$");
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 
75 const 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 };
81 const 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 
89 static int ieee80211_newstate(struct ieee80211com *, enum ieee80211_state, int);
90 
91 void
92 ieee80211_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 	ic->ic_protmode = IEEE80211_PROT_CTSONLY;
106 
107 	mtx_init(&ic->ic_mgtq.ifq_mtx, ifp->if_xname, "mgmt send q", MTX_DEF);
108 
109 	/* protocol state change handler */
110 	ic->ic_newstate = ieee80211_newstate;
111 
112 	/* initialize management frame handlers */
113 	ic->ic_recv_mgmt = ieee80211_recv_mgmt;
114 	ic->ic_send_mgmt = ieee80211_send_mgmt;
115 }
116 
117 void
118 ieee80211_proto_detach(struct ifnet *ifp)
119 {
120 	struct ieee80211com *ic = (void *)ifp;
121 
122 	IF_DRAIN(&ic->ic_mgtq);
123 	mtx_destroy(&ic->ic_mgtq.ifq_mtx);
124 }
125 
126 void
127 ieee80211_print_essid(u_int8_t *essid, int len)
128 {
129 	int i;
130 	u_int8_t *p;
131 
132 	if (len > IEEE80211_NWID_LEN)
133 		len = IEEE80211_NWID_LEN;
134 	/* determine printable or not */
135 	for (i = 0, p = essid; i < len; i++, p++) {
136 		if (*p < ' ' || *p > 0x7e)
137 			break;
138 	}
139 	if (i == len) {
140 		printf("\"");
141 		for (i = 0, p = essid; i < len; i++, p++)
142 			printf("%c", *p);
143 		printf("\"");
144 	} else {
145 		printf("0x");
146 		for (i = 0, p = essid; i < len; i++, p++)
147 			printf("%02x", *p);
148 	}
149 }
150 
151 void
152 ieee80211_dump_pkt(u_int8_t *buf, int len, int rate, int rssi)
153 {
154 	struct ieee80211_frame *wh;
155 	int i;
156 
157 	wh = (struct ieee80211_frame *)buf;
158 	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
159 	case IEEE80211_FC1_DIR_NODS:
160 		printf("NODS %s", ether_sprintf(wh->i_addr2));
161 		printf("->%s", ether_sprintf(wh->i_addr1));
162 		printf("(%s)", ether_sprintf(wh->i_addr3));
163 		break;
164 	case IEEE80211_FC1_DIR_TODS:
165 		printf("TODS %s", ether_sprintf(wh->i_addr2));
166 		printf("->%s", ether_sprintf(wh->i_addr3));
167 		printf("(%s)", ether_sprintf(wh->i_addr1));
168 		break;
169 	case IEEE80211_FC1_DIR_FROMDS:
170 		printf("FRDS %s", ether_sprintf(wh->i_addr3));
171 		printf("->%s", ether_sprintf(wh->i_addr1));
172 		printf("(%s)", ether_sprintf(wh->i_addr2));
173 		break;
174 	case IEEE80211_FC1_DIR_DSTODS:
175 		printf("DSDS %s", ether_sprintf((u_int8_t *)&wh[1]));
176 		printf("->%s", ether_sprintf(wh->i_addr3));
177 		printf("(%s", ether_sprintf(wh->i_addr2));
178 		printf("->%s)", ether_sprintf(wh->i_addr1));
179 		break;
180 	}
181 	switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
182 	case IEEE80211_FC0_TYPE_DATA:
183 		printf(" data");
184 		break;
185 	case IEEE80211_FC0_TYPE_MGT:
186 		printf(" %s", ieee80211_mgt_subtype_name[
187 		    (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK)
188 		    >> IEEE80211_FC0_SUBTYPE_SHIFT]);
189 		break;
190 	default:
191 		printf(" type#%d", wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK);
192 		break;
193 	}
194 	if (wh->i_fc[1] & IEEE80211_FC1_WEP)
195 		printf(" WEP");
196 	if (rate >= 0)
197 		printf(" %dM", rate / 2);
198 	if (rssi >= 0)
199 		printf(" +%d", rssi);
200 	printf("\n");
201 	if (len > 0) {
202 		for (i = 0; i < len; i++) {
203 			if ((i & 1) == 0)
204 				printf(" ");
205 			printf("%02x", buf[i]);
206 		}
207 		printf("\n");
208 	}
209 }
210 
211 int
212 ieee80211_fix_rate(struct ieee80211com *ic, struct ieee80211_node *ni, int flags)
213 {
214 #define	RV(v)	((v) & IEEE80211_RATE_VAL)
215 	int i, j, ignore, error;
216 	int okrate, badrate;
217 	struct ieee80211_rateset *srs, *nrs;
218 	u_int8_t r;
219 
220 	error = 0;
221 	okrate = badrate = 0;
222 	srs = &ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
223 	nrs = &ni->ni_rates;
224 	for (i = 0; i < nrs->rs_nrates; ) {
225 		ignore = 0;
226 		if (flags & IEEE80211_F_DOSORT) {
227 			/*
228 			 * Sort rates.
229 			 */
230 			for (j = i + 1; j < nrs->rs_nrates; j++) {
231 				if (RV(nrs->rs_rates[i]) > RV(nrs->rs_rates[j])) {
232 					r = nrs->rs_rates[i];
233 					nrs->rs_rates[i] = nrs->rs_rates[j];
234 					nrs->rs_rates[j] = r;
235 				}
236 			}
237 		}
238 		r = nrs->rs_rates[i] & IEEE80211_RATE_VAL;
239 		badrate = r;
240 		if (flags & IEEE80211_F_DOFRATE) {
241 			/*
242 			 * Apply fixed rate constraint.  Note that we do
243 			 * not apply the constraint to basic rates as
244 			 * otherwise we may not be able to associate if
245 			 * the rate set we submit to the AP is invalid
246 			 * (e.g. fix rate at 36Mb/s which is not a basic
247 			 * rate for 11a operation).
248 			 */
249 			if ((nrs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0 &&
250 			    ic->ic_fixed_rate >= 0 &&
251 			    r != RV(srs->rs_rates[ic->ic_fixed_rate]))
252 				ignore++;
253 		}
254 		if (flags & IEEE80211_F_DONEGO) {
255 			/*
256 			 * Check against supported rates.
257 			 */
258 			for (j = 0; j < srs->rs_nrates; j++) {
259 				if (r == RV(srs->rs_rates[j])) {
260 					/*
261 					 * Overwrite with the supported rate
262 					 * value so any basic rate bit is set.
263 					 * This insures that response we send
264 					 * to stations have the necessary basic
265 					 * rate bit set.
266 					 */
267 					nrs->rs_rates[i] = srs->rs_rates[j];
268 					break;
269 				}
270 			}
271 			if (j == srs->rs_nrates) {
272 				/*
273 				 * A rate in the node's rate set is not
274 				 * supported.  If this is a basic rate and we
275 				 * are operating as an AP then this is an error.
276 				 * Otherwise we just discard/ignore the rate.
277 				 * Note that this is important for 11b stations
278 				 * when they want to associate with an 11g AP.
279 				 */
280 				if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
281 				    (nrs->rs_rates[i] & IEEE80211_RATE_BASIC))
282 					error++;
283 				ignore++;
284 			}
285 		}
286 		if (flags & IEEE80211_F_DODEL) {
287 			/*
288 			 * Delete unacceptable rates.
289 			 */
290 			if (ignore) {
291 				nrs->rs_nrates--;
292 				for (j = i; j < nrs->rs_nrates; j++)
293 					nrs->rs_rates[j] = nrs->rs_rates[j + 1];
294 				nrs->rs_rates[j] = 0;
295 				continue;
296 			}
297 		}
298 		if (!ignore)
299 			okrate = nrs->rs_rates[i];
300 		i++;
301 	}
302 	if (okrate == 0 || error != 0)
303 		return badrate | IEEE80211_RATE_BASIC;
304 	else
305 		return RV(okrate);
306 #undef RV
307 }
308 
309 static int
310 ieee80211_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int mgt)
311 {
312 	struct ifnet *ifp = &ic->ic_if;
313 	struct ieee80211_node *ni;
314 	enum ieee80211_state ostate;
315 
316 	ostate = ic->ic_state;
317 	IEEE80211_DPRINTF(("%s: %s -> %s\n", __func__,
318 		ieee80211_state_name[ostate], ieee80211_state_name[nstate]));
319 	ic->ic_state = nstate;			/* state transition */
320 	ni = ic->ic_bss;			/* NB: no reference held */
321 	switch (nstate) {
322 	case IEEE80211_S_INIT:
323 		switch (ostate) {
324 		case IEEE80211_S_INIT:
325 			break;
326 		case IEEE80211_S_RUN:
327 			switch (ic->ic_opmode) {
328 			case IEEE80211_M_STA:
329 				IEEE80211_SEND_MGMT(ic, ni,
330 				    IEEE80211_FC0_SUBTYPE_DISASSOC,
331 				    IEEE80211_REASON_ASSOC_LEAVE);
332 				break;
333 			case IEEE80211_M_HOSTAP:
334 				IEEE80211_NODE_LOCK(ic);
335 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
336 					if (ni->ni_associd == 0)
337 						continue;
338 					IEEE80211_SEND_MGMT(ic, ni,
339 					    IEEE80211_FC0_SUBTYPE_DISASSOC,
340 					    IEEE80211_REASON_ASSOC_LEAVE);
341 				}
342 				IEEE80211_NODE_UNLOCK(ic);
343 				break;
344 			default:
345 				break;
346 			}
347 			/* FALLTHRU */
348 		case IEEE80211_S_ASSOC:
349 			switch (ic->ic_opmode) {
350 			case IEEE80211_M_STA:
351 				IEEE80211_SEND_MGMT(ic, ni,
352 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
353 				    IEEE80211_REASON_AUTH_LEAVE);
354 				break;
355 			case IEEE80211_M_HOSTAP:
356 				IEEE80211_NODE_LOCK(ic);
357 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
358 					IEEE80211_SEND_MGMT(ic, ni,
359 					    IEEE80211_FC0_SUBTYPE_DEAUTH,
360 					    IEEE80211_REASON_AUTH_LEAVE);
361 				}
362 				IEEE80211_NODE_UNLOCK(ic);
363 				break;
364 			default:
365 				break;
366 			}
367 			/* FALLTHRU */
368 		case IEEE80211_S_AUTH:
369 		case IEEE80211_S_SCAN:
370 			ic->ic_mgt_timer = 0;
371 			IF_DRAIN(&ic->ic_mgtq);
372 			if (ic->ic_wep_ctx != NULL) {
373 				free(ic->ic_wep_ctx, M_DEVBUF);
374 				ic->ic_wep_ctx = NULL;
375 			}
376 			ieee80211_free_allnodes(ic);
377 			break;
378 		}
379 		break;
380 	case IEEE80211_S_SCAN:
381 		ic->ic_flags &= ~IEEE80211_F_SIBSS;
382 		/* initialize bss for probe request */
383 		IEEE80211_ADDR_COPY(ni->ni_macaddr, ifp->if_broadcastaddr);
384 		IEEE80211_ADDR_COPY(ni->ni_bssid, ifp->if_broadcastaddr);
385 		ni->ni_rates = ic->ic_sup_rates[
386 			ieee80211_chan2mode(ic, ni->ni_chan)];
387 		ni->ni_associd = 0;
388 		ni->ni_rstamp = 0;
389 		switch (ostate) {
390 		case IEEE80211_S_INIT:
391 			if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
392 			    ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
393 				/*
394 				 * AP operation and we already have a channel;
395 				 * bypass the scan and startup immediately.
396 				 */
397 				ieee80211_create_ibss(ic, ic->ic_des_chan);
398 			} else {
399 				ieee80211_begin_scan(ifp);
400 			}
401 			break;
402 		case IEEE80211_S_SCAN:
403 			/* scan next */
404 			if (ic->ic_flags & IEEE80211_F_ASCAN) {
405 				IEEE80211_SEND_MGMT(ic, ni,
406 				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
407 			}
408 			break;
409 		case IEEE80211_S_RUN:
410 			/* beacon miss */
411 			if (ifp->if_flags & IFF_DEBUG) {
412 				/* XXX bssid clobbered above */
413 				if_printf(ifp, "no recent beacons from %s;"
414 				    " rescanning\n",
415 				    ether_sprintf(ic->ic_bss->ni_bssid));
416 			}
417 			ieee80211_free_allnodes(ic);
418 			/* FALLTHRU */
419 		case IEEE80211_S_AUTH:
420 		case IEEE80211_S_ASSOC:
421 			/* timeout restart scan */
422 			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
423 			if (ni != NULL) {
424 				ni->ni_fails++;
425 				ieee80211_unref_node(&ni);
426 			}
427 			ieee80211_begin_scan(ifp);
428 			break;
429 		}
430 		break;
431 	case IEEE80211_S_AUTH:
432 		switch (ostate) {
433 		case IEEE80211_S_INIT:
434 			IEEE80211_DPRINTF(("%s: invalid transition\n",
435 				__func__));
436 			break;
437 		case IEEE80211_S_SCAN:
438 			IEEE80211_SEND_MGMT(ic, ni,
439 			    IEEE80211_FC0_SUBTYPE_AUTH, 1);
440 			break;
441 		case IEEE80211_S_AUTH:
442 		case IEEE80211_S_ASSOC:
443 			switch (mgt) {
444 			case IEEE80211_FC0_SUBTYPE_AUTH:
445 				/* ??? */
446 				IEEE80211_SEND_MGMT(ic, ni,
447 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
448 				break;
449 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
450 				/* ignore and retry scan on timeout */
451 				break;
452 			}
453 			break;
454 		case IEEE80211_S_RUN:
455 			switch (mgt) {
456 			case IEEE80211_FC0_SUBTYPE_AUTH:
457 				IEEE80211_SEND_MGMT(ic, ni,
458 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
459 				ic->ic_state = ostate;	/* stay RUN */
460 				break;
461 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
462 				/* try to reauth */
463 				IEEE80211_SEND_MGMT(ic, ni,
464 				    IEEE80211_FC0_SUBTYPE_AUTH, 1);
465 				break;
466 			}
467 			break;
468 		}
469 		break;
470 	case IEEE80211_S_ASSOC:
471 		switch (ostate) {
472 		case IEEE80211_S_INIT:
473 		case IEEE80211_S_SCAN:
474 		case IEEE80211_S_ASSOC:
475 			IEEE80211_DPRINTF(("%s: invalid transition\n",
476 				__func__));
477 			break;
478 		case IEEE80211_S_AUTH:
479 			IEEE80211_SEND_MGMT(ic, ni,
480 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 0);
481 			break;
482 		case IEEE80211_S_RUN:
483 			IEEE80211_SEND_MGMT(ic, ni,
484 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 1);
485 			break;
486 		}
487 		break;
488 	case IEEE80211_S_RUN:
489 		switch (ostate) {
490 		case IEEE80211_S_INIT:
491 		case IEEE80211_S_AUTH:
492 		case IEEE80211_S_RUN:
493 			IEEE80211_DPRINTF(("%s: invalid transition\n",
494 				__func__));
495 			break;
496 		case IEEE80211_S_SCAN:		/* adhoc/hostap mode */
497 		case IEEE80211_S_ASSOC:		/* infra mode */
498 			KASSERT(ni->ni_txrate < ni->ni_rates.rs_nrates,
499 				("%s: bogus xmit rate %u setup\n", __func__,
500 					ni->ni_txrate));
501 			if (ifp->if_flags & IFF_DEBUG) {
502 				if_printf(ifp, " ");
503 				if (ic->ic_opmode == IEEE80211_M_STA)
504 					printf("associated ");
505 				else
506 					printf("synchronized ");
507 				printf("with %s ssid ",
508 				    ether_sprintf(ni->ni_bssid));
509 				ieee80211_print_essid(ic->ic_bss->ni_essid,
510 				    ni->ni_esslen);
511 				printf(" channel %d start %uMb\n",
512 					ieee80211_chan2ieee(ic, ni->ni_chan),
513 					IEEE80211_RATE2MBS(ni->ni_rates.rs_rates[ni->ni_txrate]));
514 			}
515 			ic->ic_mgt_timer = 0;
516 			if_start(ifp);
517 			break;
518 		}
519 		break;
520 	}
521 	return 0;
522 }
523