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ieee80211_proto.c revision 1.7
      1 /*	$NetBSD: ieee80211_proto.c,v 1.7 2004/01/13 23:37:30 dyoung 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 1.6 2003/10/31 18:32:09 brooks Exp $");
     37 #else
     38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_proto.c,v 1.7 2004/01/13 23:37:30 dyoung 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 #define	IEEE80211_RATE2MBS(r)	(((r) & IEEE80211_RATE_VAL) / 2)
     92 
     93 const char *ieee80211_mgt_subtype_name[] = {
     94 	"assoc_req",	"assoc_resp",	"reassoc_req",	"reassoc_resp",
     95 	"probe_req",	"probe_resp",	"reserved#6",	"reserved#7",
     96 	"beacon",	"atim",		"disassoc",	"auth",
     97 	"deauth",	"reserved#13",	"reserved#14",	"reserved#15"
     98 };
     99 const char *ieee80211_state_name[IEEE80211_S_MAX] = {
    100 	"INIT",		/* IEEE80211_S_INIT */
    101 	"SCAN",		/* IEEE80211_S_SCAN */
    102 	"AUTH",		/* IEEE80211_S_AUTH */
    103 	"ASSOC",	/* IEEE80211_S_ASSOC */
    104 	"RUN"		/* IEEE80211_S_RUN */
    105 };
    106 
    107 static int ieee80211_newstate(struct ieee80211com *, enum ieee80211_state, int);
    108 
    109 void
    110 ieee80211_proto_attach(struct ifnet *ifp)
    111 {
    112 	struct ieee80211com *ic = (void *)ifp;
    113 
    114 	ifp->if_hdrlen = sizeof(struct ieee80211_frame);
    115 
    116 #ifdef notdef
    117 	ic->ic_rtsthreshold = IEEE80211_RTS_DEFAULT;
    118 #else
    119 	ic->ic_rtsthreshold = IEEE80211_RTS_MAX;
    120 #endif
    121 	ic->ic_fragthreshold = 2346;		/* XXX not used yet */
    122 	ic->ic_fixed_rate = -1;			/* no fixed rate */
    123 
    124 #ifdef __FreeBSD__
    125 	mtx_init(&ic->ic_mgtq.ifq_mtx, ifp->if_xname, "mgmt send q", MTX_DEF);
    126 #endif
    127 
    128 	/* protocol state change handler */
    129 	ic->ic_newstate = ieee80211_newstate;
    130 
    131 	/* initialize management frame handlers */
    132 	ic->ic_recv_mgmt = ieee80211_recv_mgmt;
    133 	ic->ic_send_mgmt = ieee80211_send_mgmt;
    134 }
    135 
    136 void
    137 ieee80211_proto_detach(struct ifnet *ifp)
    138 {
    139 	struct ieee80211com *ic = (void *)ifp;
    140 
    141 #ifdef __FreeBSD__
    142 	IF_DRAIN(&ic->ic_mgtq);
    143 	mtx_destroy(&ic->ic_mgtq.ifq_mtx);
    144 #else
    145 	IF_PURGE(&ic->ic_mgtq);
    146 	IF_PURGE(&ic->ic_pwrsaveq);
    147 #endif
    148 }
    149 
    150 void
    151 ieee80211_print_essid(u_int8_t *essid, int len)
    152 {
    153 	int i;
    154 	u_int8_t *p;
    155 
    156 	if (len > IEEE80211_NWID_LEN)
    157 		len = IEEE80211_NWID_LEN;
    158 	/* determine printable or not */
    159 	for (i = 0, p = essid; i < len; i++, p++) {
    160 		if (*p < ' ' || *p > 0x7e)
    161 			break;
    162 	}
    163 	if (i == len) {
    164 		printf("\"");
    165 		for (i = 0, p = essid; i < len; i++, p++)
    166 			printf("%c", *p);
    167 		printf("\"");
    168 	} else {
    169 		printf("0x");
    170 		for (i = 0, p = essid; i < len; i++, p++)
    171 			printf("%02x", *p);
    172 	}
    173 }
    174 
    175 void
    176 ieee80211_dump_pkt(u_int8_t *buf, int len, int rate, int rssi)
    177 {
    178 	struct ieee80211_frame *wh;
    179 	int i;
    180 
    181 	wh = (struct ieee80211_frame *)buf;
    182 	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
    183 	case IEEE80211_FC1_DIR_NODS:
    184 		printf("NODS %s", ether_sprintf(wh->i_addr2));
    185 		printf("->%s", ether_sprintf(wh->i_addr1));
    186 		printf("(%s)", ether_sprintf(wh->i_addr3));
    187 		break;
    188 	case IEEE80211_FC1_DIR_TODS:
    189 		printf("TODS %s", ether_sprintf(wh->i_addr2));
    190 		printf("->%s", ether_sprintf(wh->i_addr3));
    191 		printf("(%s)", ether_sprintf(wh->i_addr1));
    192 		break;
    193 	case IEEE80211_FC1_DIR_FROMDS:
    194 		printf("FRDS %s", ether_sprintf(wh->i_addr3));
    195 		printf("->%s", ether_sprintf(wh->i_addr1));
    196 		printf("(%s)", ether_sprintf(wh->i_addr2));
    197 		break;
    198 	case IEEE80211_FC1_DIR_DSTODS:
    199 		printf("DSDS %s", ether_sprintf((u_int8_t *)&wh[1]));
    200 		printf("->%s", ether_sprintf(wh->i_addr3));
    201 		printf("(%s", ether_sprintf(wh->i_addr2));
    202 		printf("->%s)", ether_sprintf(wh->i_addr1));
    203 		break;
    204 	}
    205 	switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
    206 	case IEEE80211_FC0_TYPE_DATA:
    207 		printf(" data");
    208 		break;
    209 	case IEEE80211_FC0_TYPE_MGT:
    210 		printf(" %s", ieee80211_mgt_subtype_name[
    211 		    (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK)
    212 		    >> IEEE80211_FC0_SUBTYPE_SHIFT]);
    213 		break;
    214 	default:
    215 		printf(" type#%d", wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK);
    216 		break;
    217 	}
    218 	if (wh->i_fc[1] & IEEE80211_FC1_WEP)
    219 		printf(" WEP");
    220 	if (rate >= 0)
    221 		printf(" %dM", rate / 2);
    222 	if (rssi >= 0)
    223 		printf(" +%d", rssi);
    224 	printf("\n");
    225 	if (len > 0) {
    226 		for (i = 0; i < len; i++) {
    227 			if ((i & 1) == 0)
    228 				printf(" ");
    229 			printf("%02x", buf[i]);
    230 		}
    231 		printf("\n");
    232 	}
    233 }
    234 
    235 int
    236 ieee80211_fix_rate(struct ieee80211com *ic, struct ieee80211_node *ni, int flags)
    237 {
    238 #define	RV(v)	((v) & IEEE80211_RATE_VAL)
    239 	int i, j, ignore, error;
    240 	int okrate, badrate;
    241 	struct ieee80211_rateset *srs, *nrs;
    242 	u_int8_t r;
    243 
    244 	error = 0;
    245 	okrate = badrate = 0;
    246 	srs = &ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
    247 	nrs = &ni->ni_rates;
    248 	for (i = 0; i < nrs->rs_nrates; ) {
    249 		ignore = 0;
    250 		if (flags & IEEE80211_F_DOSORT) {
    251 			/*
    252 			 * Sort rates.
    253 			 */
    254 			for (j = i + 1; j < nrs->rs_nrates; j++) {
    255 				if (RV(nrs->rs_rates[i]) > RV(nrs->rs_rates[j])) {
    256 					r = nrs->rs_rates[i];
    257 					nrs->rs_rates[i] = nrs->rs_rates[j];
    258 					nrs->rs_rates[j] = r;
    259 				}
    260 			}
    261 		}
    262 		r = nrs->rs_rates[i] & IEEE80211_RATE_VAL;
    263 		badrate = r;
    264 		if (flags & IEEE80211_F_DOFRATE) {
    265 			/*
    266 			 * Apply fixed rate constraint.  Note that we do
    267 			 * not apply the constraint to basic rates as
    268 			 * otherwise we may not be able to associate if
    269 			 * the rate set we submit to the AP is invalid
    270 			 * (e.g. fix rate at 36Mb/s which is not a basic
    271 			 * rate for 11a operation).
    272 			 */
    273 			if ((nrs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0 &&
    274 			    ic->ic_fixed_rate >= 0 &&
    275 			    r != RV(srs->rs_rates[ic->ic_fixed_rate]))
    276 				ignore++;
    277 		}
    278 		if (flags & IEEE80211_F_DONEGO) {
    279 			/*
    280 			 * Check against supported rates.
    281 			 */
    282 			for (j = 0; j < srs->rs_nrates; j++) {
    283 				if (r == RV(srs->rs_rates[j]))
    284 					break;
    285 			}
    286 			if (j == srs->rs_nrates) {
    287 				/*
    288 				 * A rate in the node's rate set is not
    289 				 * supported.  If this is a basic rate and we
    290 				 * are operating as an AP then this is an error.
    291 				 * Otherwise we just discard/ignore the rate.
    292 				 * Note that this is important for 11b stations
    293 				 * when they want to associate with an 11g AP.
    294 				 */
    295 				if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
    296 				    (nrs->rs_rates[i] & IEEE80211_RATE_BASIC))
    297 					error++;
    298 				ignore++;
    299 			}
    300 		}
    301 		if (flags & IEEE80211_F_DODEL) {
    302 			/*
    303 			 * Delete unacceptable rates.
    304 			 */
    305 			if (ignore) {
    306 				nrs->rs_nrates--;
    307 				for (j = i; j < nrs->rs_nrates; j++)
    308 					nrs->rs_rates[j] = nrs->rs_rates[j + 1];
    309 				nrs->rs_rates[j] = 0;
    310 				continue;
    311 			}
    312 		}
    313 		if (!ignore)
    314 			okrate = nrs->rs_rates[i];
    315 		i++;
    316 	}
    317 	if (okrate == 0 || error != 0)
    318 		return badrate | IEEE80211_RATE_BASIC;
    319 	else
    320 		return RV(okrate);
    321 #undef RV
    322 }
    323 
    324 static int
    325 ieee80211_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int mgt)
    326 {
    327 	struct ifnet *ifp = &ic->ic_if;
    328 	struct ieee80211_node *ni;
    329 	enum ieee80211_state ostate;
    330 	ieee80211_node_critsec_decl(s);
    331 
    332 	ostate = ic->ic_state;
    333 	IEEE80211_DPRINTF(("%s: %s -> %s\n", __func__,
    334 		ieee80211_state_name[ostate], ieee80211_state_name[nstate]));
    335 	ic->ic_state = nstate;			/* state transition */
    336 	ni = ic->ic_bss;			/* NB: no reference held */
    337 	switch (nstate) {
    338 	case IEEE80211_S_INIT:
    339 		switch (ostate) {
    340 		case IEEE80211_S_INIT:
    341 			break;
    342 		case IEEE80211_S_RUN:
    343 			switch (ic->ic_opmode) {
    344 			case IEEE80211_M_STA:
    345 				IEEE80211_SEND_MGMT(ic, ni,
    346 				    IEEE80211_FC0_SUBTYPE_DISASSOC,
    347 				    IEEE80211_REASON_ASSOC_LEAVE);
    348 				break;
    349 			case IEEE80211_M_HOSTAP:
    350 				ieee80211_node_critsec_begin(ic, s);
    351 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
    352 					if (ni->ni_associd == 0)
    353 						continue;
    354 					IEEE80211_SEND_MGMT(ic, ni,
    355 					    IEEE80211_FC0_SUBTYPE_DISASSOC,
    356 					    IEEE80211_REASON_ASSOC_LEAVE);
    357 				}
    358 				ieee80211_node_critsec_end(ic, s);
    359 				break;
    360 			default:
    361 				break;
    362 			}
    363 			/* FALLTHRU */
    364 		case IEEE80211_S_ASSOC:
    365 			switch (ic->ic_opmode) {
    366 			case IEEE80211_M_STA:
    367 				IEEE80211_SEND_MGMT(ic, ni,
    368 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
    369 				    IEEE80211_REASON_AUTH_LEAVE);
    370 				break;
    371 			case IEEE80211_M_HOSTAP:
    372 				ieee80211_node_critsec_begin(ic, s);
    373 				TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
    374 					IEEE80211_SEND_MGMT(ic, ni,
    375 					    IEEE80211_FC0_SUBTYPE_DEAUTH,
    376 					    IEEE80211_REASON_AUTH_LEAVE);
    377 				}
    378 				ieee80211_node_critsec_end(ic, s);
    379 				break;
    380 			default:
    381 				break;
    382 			}
    383 			/* FALLTHRU */
    384 		case IEEE80211_S_AUTH:
    385 		case IEEE80211_S_SCAN:
    386 			ic->ic_mgt_timer = 0;
    387 #ifdef __FreeBSD__
    388 			IF_DRAIN(&ic->ic_mgtq);
    389 #else
    390 			IF_PURGE(&ic->ic_mgtq);
    391 			IF_PURGE(&ic->ic_pwrsaveq);
    392 #endif
    393 			if (ic->ic_wep_ctx != NULL) {
    394 				free(ic->ic_wep_ctx, M_DEVBUF);
    395 				ic->ic_wep_ctx = NULL;
    396 			}
    397 			ieee80211_free_allnodes(ic);
    398 			break;
    399 		}
    400 		break;
    401 	case IEEE80211_S_SCAN:
    402 		ic->ic_flags &= ~IEEE80211_F_SIBSS;
    403 		/* initialize bss for probe request */
    404 		IEEE80211_ADDR_COPY(ni->ni_macaddr, ifp->if_broadcastaddr);
    405 		IEEE80211_ADDR_COPY(ni->ni_bssid, ifp->if_broadcastaddr);
    406 		ni->ni_rates = ic->ic_sup_rates[
    407 			ieee80211_chan2mode(ic, ni->ni_chan)];
    408 		ni->ni_associd = 0;
    409 		ni->ni_rstamp = 0;
    410 		switch (ostate) {
    411 		case IEEE80211_S_INIT:
    412 			if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
    413 			    ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
    414 				/*
    415 				 * AP operation and we already have a channel;
    416 				 * bypass the scan and startup immediately.
    417 				 */
    418 				ieee80211_create_ibss(ic, ic->ic_des_chan);
    419 			} else {
    420 				ieee80211_begin_scan(ifp);
    421 			}
    422 			break;
    423 		case IEEE80211_S_SCAN:
    424 			/* scan next */
    425 			if (ic->ic_flags & IEEE80211_F_ASCAN) {
    426 				IEEE80211_SEND_MGMT(ic, ni,
    427 				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
    428 			}
    429 			break;
    430 		case IEEE80211_S_RUN:
    431 			/* beacon miss */
    432 			if (ifp->if_flags & IFF_DEBUG) {
    433 				/* XXX bssid clobbered above */
    434 				if_printf(ifp, "no recent beacons from %s;"
    435 				    " rescanning\n",
    436 				    ether_sprintf(ic->ic_bss->ni_bssid));
    437 			}
    438 			ieee80211_free_allnodes(ic);
    439 			/* FALLTHRU */
    440 		case IEEE80211_S_AUTH:
    441 		case IEEE80211_S_ASSOC:
    442 			/* timeout restart scan */
    443 			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
    444 			if (ni != NULL) {
    445 				ni->ni_fails++;
    446 				ieee80211_unref_node(&ni);
    447 			}
    448 			ieee80211_begin_scan(ifp);
    449 			break;
    450 		}
    451 		break;
    452 	case IEEE80211_S_AUTH:
    453 		switch (ostate) {
    454 		case IEEE80211_S_INIT:
    455 			IEEE80211_DPRINTF(("%s: invalid transition\n",
    456 				__func__));
    457 			break;
    458 		case IEEE80211_S_SCAN:
    459 			IEEE80211_SEND_MGMT(ic, ni,
    460 			    IEEE80211_FC0_SUBTYPE_AUTH, 1);
    461 			break;
    462 		case IEEE80211_S_AUTH:
    463 		case IEEE80211_S_ASSOC:
    464 			switch (mgt) {
    465 			case IEEE80211_FC0_SUBTYPE_AUTH:
    466 				/* ??? */
    467 				IEEE80211_SEND_MGMT(ic, ni,
    468 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
    469 				break;
    470 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
    471 				/* ignore and retry scan on timeout */
    472 				break;
    473 			}
    474 			break;
    475 		case IEEE80211_S_RUN:
    476 			switch (mgt) {
    477 			case IEEE80211_FC0_SUBTYPE_AUTH:
    478 				IEEE80211_SEND_MGMT(ic, ni,
    479 				    IEEE80211_FC0_SUBTYPE_AUTH, 2);
    480 				ic->ic_state = ostate;	/* stay RUN */
    481 				break;
    482 			case IEEE80211_FC0_SUBTYPE_DEAUTH:
    483 				/* try to reauth */
    484 				IEEE80211_SEND_MGMT(ic, ni,
    485 				    IEEE80211_FC0_SUBTYPE_AUTH, 1);
    486 				break;
    487 			}
    488 			break;
    489 		}
    490 		break;
    491 	case IEEE80211_S_ASSOC:
    492 		switch (ostate) {
    493 		case IEEE80211_S_INIT:
    494 		case IEEE80211_S_SCAN:
    495 		case IEEE80211_S_ASSOC:
    496 			IEEE80211_DPRINTF(("%s: invalid transition\n",
    497 				__func__));
    498 			break;
    499 		case IEEE80211_S_AUTH:
    500 			IEEE80211_SEND_MGMT(ic, ni,
    501 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 0);
    502 			break;
    503 		case IEEE80211_S_RUN:
    504 			IEEE80211_SEND_MGMT(ic, ni,
    505 			    IEEE80211_FC0_SUBTYPE_ASSOC_REQ, 1);
    506 			break;
    507 		}
    508 		break;
    509 	case IEEE80211_S_RUN:
    510 		switch (ostate) {
    511 		case IEEE80211_S_INIT:
    512 		case IEEE80211_S_AUTH:
    513 		case IEEE80211_S_RUN:
    514 			IEEE80211_DPRINTF(("%s: invalid transition\n",
    515 				__func__));
    516 			break;
    517 		case IEEE80211_S_SCAN:		/* adhoc/hostap mode */
    518 		case IEEE80211_S_ASSOC:		/* infra mode */
    519 			IASSERT(ni->ni_txrate < ni->ni_rates.rs_nrates,
    520 				("%s: bogus xmit rate %u setup\n", __func__,
    521 					ni->ni_txrate));
    522 			if (ifp->if_flags & IFF_DEBUG) {
    523 				if_printf(ifp, " ");
    524 				if (ic->ic_opmode == IEEE80211_M_STA)
    525 					printf("associated ");
    526 				else
    527 					printf("synchronized ");
    528 				printf("with %s ssid ",
    529 				    ether_sprintf(ni->ni_bssid));
    530 				ieee80211_print_essid(ic->ic_bss->ni_essid,
    531 				    ni->ni_esslen);
    532 				printf(" channel %d start %uMb\n",
    533 					ieee80211_chan2ieee(ic, ni->ni_chan),
    534 					IEEE80211_RATE2MBS(ni->ni_rates.rs_rates[ni->ni_txrate]));
    535 			}
    536 			ic->ic_mgt_timer = 0;
    537 			(*ifp->if_start)(ifp);
    538 			break;
    539 		}
    540 		break;
    541 	}
    542 	return 0;
    543 }
    544