xref: /freebsd/sys/net80211/ieee80211_proto.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 
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 
116 void
117 ieee80211_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 
125 void
126 ieee80211_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 
150 void
151 ieee80211_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 
210 int
211 ieee80211_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 < ni->ni_rates.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 				if (nrs->rs_rates[i] & IEEE80211_RATE_BASIC)
263 					error++;
264 				ignore++;
265 			}
266 		}
267 		if (flags & IEEE80211_F_DODEL) {
268 			/*
269 			 * Delete unacceptable rates.
270 			 */
271 			if (ignore) {
272 				nrs->rs_nrates--;
273 				for (j = i; j < nrs->rs_nrates; j++)
274 					nrs->rs_rates[j] = nrs->rs_rates[j + 1];
275 				nrs->rs_rates[j] = 0;
276 				continue;
277 			}
278 		}
279 		if (!ignore)
280 			okrate = nrs->rs_rates[i];
281 		i++;
282 	}
283 	if (okrate == 0 || error != 0)
284 		return badrate | IEEE80211_RATE_BASIC;
285 	else
286 		return RV(okrate);
287 #undef RV
288 }
289 
290 static int
291 ieee80211_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int mgt)
292 {
293 	struct ifnet *ifp = &ic->ic_if;
294 	struct ieee80211_node *ni;
295 	enum ieee80211_state ostate;
296 
297 	ostate = ic->ic_state;
298 	IEEE80211_DPRINTF(("%s: %s -> %s\n", __func__,
299 		ieee80211_state_name[ostate], ieee80211_state_name[nstate]));
300 	ic->ic_state = nstate;			/* state transition */
301 	ni = ic->ic_bss;			/* NB: no reference held */
302 	switch (nstate) {
303 	case IEEE80211_S_INIT:
304 		switch (ostate) {
305 		case IEEE80211_S_INIT:
306 			break;
307 		case IEEE80211_S_RUN:
308 			switch (ic->ic_opmode) {
309 			case IEEE80211_M_STA:
310 				IEEE80211_SEND_MGMT(ic, ni,
311 				    IEEE80211_FC0_SUBTYPE_DISASSOC,
312 				    IEEE80211_REASON_ASSOC_LEAVE);
313 				break;
314 			case IEEE80211_M_HOSTAP:
315 				mtx_lock(&ic->ic_nodelock);
316 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
317 					if (ni->ni_associd == 0)
318 						continue;
319 					IEEE80211_SEND_MGMT(ic, ni,
320 					    IEEE80211_FC0_SUBTYPE_DISASSOC,
321 					    IEEE80211_REASON_ASSOC_LEAVE);
322 				}
323 				mtx_unlock(&ic->ic_nodelock);
324 				break;
325 			default:
326 				break;
327 			}
328 			/* FALLTHRU */
329 		case IEEE80211_S_ASSOC:
330 			switch (ic->ic_opmode) {
331 			case IEEE80211_M_STA:
332 				IEEE80211_SEND_MGMT(ic, ni,
333 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
334 				    IEEE80211_REASON_AUTH_LEAVE);
335 				break;
336 			case IEEE80211_M_HOSTAP:
337 				mtx_lock(&ic->ic_nodelock);
338 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
339 					IEEE80211_SEND_MGMT(ic, ni,
340 					    IEEE80211_FC0_SUBTYPE_DEAUTH,
341 					    IEEE80211_REASON_AUTH_LEAVE);
342 				}
343 				mtx_unlock(&ic->ic_nodelock);
344 				break;
345 			default:
346 				break;
347 			}
348 			/* FALLTHRU */
349 		case IEEE80211_S_AUTH:
350 		case IEEE80211_S_SCAN:
351 			ic->ic_mgt_timer = 0;
352 			IF_DRAIN(&ic->ic_mgtq);
353 			if (ic->ic_wep_ctx != NULL) {
354 				free(ic->ic_wep_ctx, M_DEVBUF);
355 				ic->ic_wep_ctx = NULL;
356 			}
357 			ieee80211_free_allnodes(ic);
358 			break;
359 		}
360 		break;
361 	case IEEE80211_S_SCAN:
362 		ic->ic_flags &= ~IEEE80211_F_SIBSS;
363 		/* initialize bss for probe request */
364 		IEEE80211_ADDR_COPY(ni->ni_macaddr, ifp->if_broadcastaddr);
365 		IEEE80211_ADDR_COPY(ni->ni_bssid, ifp->if_broadcastaddr);
366 		ni->ni_rates = ic->ic_sup_rates[
367 			ieee80211_chan2mode(ic, ni->ni_chan)];
368 		ni->ni_associd = 0;
369 		ni->ni_rstamp = 0;
370 		switch (ostate) {
371 		case IEEE80211_S_INIT:
372 			if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
373 			    ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
374 				/*
375 				 * AP operation and we already have a channel;
376 				 * bypass the scan and startup immediately.
377 				 */
378 				ieee80211_create_ibss(ic, ic->ic_des_chan);
379 			} else {
380 				ieee80211_begin_scan(ifp);
381 			}
382 			break;
383 		case IEEE80211_S_SCAN:
384 			/* scan next */
385 			if (ic->ic_flags & IEEE80211_F_ASCAN) {
386 				IEEE80211_SEND_MGMT(ic, ni,
387 				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
388 			}
389 			break;
390 		case IEEE80211_S_RUN:
391 			/* beacon miss */
392 			if (ifp->if_flags & IFF_DEBUG) {
393 				/* XXX bssid clobbered above */
394 				if_printf(ifp, "no recent beacons from %s;"
395 				    " rescanning\n",
396 				    ether_sprintf(ic->ic_bss->ni_bssid));
397 			}
398 			ieee80211_free_allnodes(ic);
399 			/* FALLTHRU */
400 		case IEEE80211_S_AUTH:
401 		case IEEE80211_S_ASSOC:
402 			/* timeout restart scan */
403 			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
404 			if (ni != NULL) {
405 				ni->ni_fails++;
406 				ieee80211_unref_node(&ni);
407 			}
408 			ieee80211_begin_scan(ifp);
409 			break;
410 		}
411 		break;
412 	case IEEE80211_S_AUTH:
413 		switch (ostate) {
414 		case IEEE80211_S_INIT:
415 			IEEE80211_DPRINTF(("%s: invalid transition\n",
416 				__func__));
417 			break;
418 		case IEEE80211_S_SCAN:
419 			IEEE80211_SEND_MGMT(ic, ni,
420 			    IEEE80211_FC0_SUBTYPE_AUTH, 1);
421 			break;
422 		case IEEE80211_S_AUTH:
423 		case IEEE80211_S_ASSOC:
424 			switch (mgt) {
425 			case IEEE80211_FC0_SUBTYPE_AUTH:
426 				/* ??? */
427 				IEEE80211_SEND_MGMT(ic, ni,
428 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
429 				break;
430 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
431 				/* ignore and retry scan on timeout */
432 				break;
433 			}
434 			break;
435 		case IEEE80211_S_RUN:
436 			switch (mgt) {
437 			case IEEE80211_FC0_SUBTYPE_AUTH:
438 				IEEE80211_SEND_MGMT(ic, ni,
439 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
440 				ic->ic_state = ostate;	/* stay RUN */
441 				break;
442 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
443 				/* try to reauth */
444 				IEEE80211_SEND_MGMT(ic, ni,
445 				    IEEE80211_FC0_SUBTYPE_AUTH, 1);
446 				break;
447 			}
448 			break;
449 		}
450 		break;
451 	case IEEE80211_S_ASSOC:
452 		switch (ostate) {
453 		case IEEE80211_S_INIT:
454 		case IEEE80211_S_SCAN:
455 		case IEEE80211_S_ASSOC:
456 			IEEE80211_DPRINTF(("%s: invalid transition\n",
457 				__func__));
458 			break;
459 		case IEEE80211_S_AUTH:
460 			IEEE80211_SEND_MGMT(ic, ni,
461 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 0);
462 			break;
463 		case IEEE80211_S_RUN:
464 			IEEE80211_SEND_MGMT(ic, ni,
465 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 1);
466 			break;
467 		}
468 		break;
469 	case IEEE80211_S_RUN:
470 		switch (ostate) {
471 		case IEEE80211_S_INIT:
472 		case IEEE80211_S_AUTH:
473 		case IEEE80211_S_RUN:
474 			IEEE80211_DPRINTF(("%s: invalid transition\n",
475 				__func__));
476 			break;
477 		case IEEE80211_S_SCAN:		/* adhoc/hostap mode */
478 		case IEEE80211_S_ASSOC:		/* infra mode */
479 			KASSERT(ni->ni_txrate < ni->ni_rates.rs_nrates,
480 				("%s: bogus xmit rate %u setup\n", __func__,
481 					ni->ni_txrate));
482 			if (ifp->if_flags & IFF_DEBUG) {
483 				if_printf(ifp, " ");
484 				if (ic->ic_opmode == IEEE80211_M_STA)
485 					printf("associated ");
486 				else
487 					printf("synchronized ");
488 				printf("with %s ssid ",
489 				    ether_sprintf(ni->ni_bssid));
490 				ieee80211_print_essid(ic->ic_bss->ni_essid,
491 				    ni->ni_esslen);
492 				printf(" channel %d start %uMb\n",
493 					ieee80211_chan2ieee(ic, ni->ni_chan),
494 					IEEE80211_RATE2MBS(ni->ni_rates.rs_rates[ni->ni_txrate]));
495 			}
496 			ic->ic_mgt_timer = 0;
497 			(*ifp->if_start)(ifp);
498 			break;
499 		}
500 		break;
501 	}
502 	return 0;
503 }
504