xref: /freebsd/sys/dev/ath/if_ath_keycache.c (revision 076ad2f8) 
1 /*-
2  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13  *    redistribution must be conditioned upon including a substantially
14  *    similar Disclaimer requirement for further binary redistribution.
15  *
16  * NO WARRANTY
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGES.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * Driver for the Atheros Wireless LAN controller.
35  *
36  * This software is derived from work of Atsushi Onoe; his contribution
37  * is greatly appreciated.
38  */
39 
40 #include "opt_inet.h"
41 #include "opt_ath.h"
42 #include "opt_wlan.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysctl.h>
47 #include <sys/mbuf.h>
48 #include <sys/malloc.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/errno.h>
55 #include <sys/callout.h>
56 #include <sys/bus.h>
57 #include <sys/endian.h>
58 #include <sys/kthread.h>
59 #include <sys/taskqueue.h>
60 #include <sys/priv.h>
61 
62 #include <machine/bus.h>
63 
64 #include <net/if.h>
65 #include <net/if_var.h>
66 #include <net/if_dl.h>
67 #include <net/if_media.h>
68 #include <net/if_types.h>
69 #include <net/if_arp.h>
70 #include <net/ethernet.h>
71 #include <net/if_llc.h>
72 
73 #include <net80211/ieee80211_var.h>
74 
75 #include <net/bpf.h>
76 
77 #include <dev/ath/if_athvar.h>
78 
79 #include <dev/ath/if_ath_debug.h>
80 #include <dev/ath/if_ath_keycache.h>
81 #include <dev/ath/if_ath_misc.h>
82 
83 #ifdef ATH_DEBUG
84 static void
85 ath_keyprint(struct ath_softc *sc, const char *tag, u_int ix,
86 	const HAL_KEYVAL *hk, const u_int8_t mac[IEEE80211_ADDR_LEN])
87 {
88 	static const char *ciphers[] = {
89 		"WEP",
90 		"AES-OCB",
91 		"AES-CCM",
92 		"CKIP",
93 		"TKIP",
94 		"CLR",
95 	};
96 	int i, n;
97 
98 	printf("%s: [%02u] %-7s ", tag, ix, ciphers[hk->kv_type]);
99 	for (i = 0, n = hk->kv_len; i < n; i++)
100 		printf("%02x", hk->kv_val[i]);
101 	printf(" mac %s", ether_sprintf(mac));
102 	if (hk->kv_type == HAL_CIPHER_TKIP) {
103 		printf(" %s ", sc->sc_splitmic ? "mic" : "rxmic");
104 		for (i = 0; i < sizeof(hk->kv_mic); i++)
105 			printf("%02x", hk->kv_mic[i]);
106 		if (!sc->sc_splitmic) {
107 			printf(" txmic ");
108 			for (i = 0; i < sizeof(hk->kv_txmic); i++)
109 				printf("%02x", hk->kv_txmic[i]);
110 		}
111 	}
112 	printf("\n");
113 }
114 #endif
115 
116 /*
117  * Set a TKIP key into the hardware.  This handles the
118  * potential distribution of key state to multiple key
119  * cache slots for TKIP.
120  */
121 static int
122 ath_keyset_tkip(struct ath_softc *sc, const struct ieee80211_key *k,
123 	HAL_KEYVAL *hk, const u_int8_t mac[IEEE80211_ADDR_LEN])
124 {
125 #define	IEEE80211_KEY_XR	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV)
126 	static const u_int8_t zerobssid[IEEE80211_ADDR_LEN];
127 	struct ath_hal *ah = sc->sc_ah;
128 
129 	KASSERT(k->wk_cipher->ic_cipher == IEEE80211_CIPHER_TKIP,
130 		("got a non-TKIP key, cipher %u", k->wk_cipher->ic_cipher));
131 	if ((k->wk_flags & IEEE80211_KEY_XR) == IEEE80211_KEY_XR) {
132 		if (sc->sc_splitmic) {
133 			/*
134 			 * TX key goes at first index, RX key at the rx index.
135 			 * The hal handles the MIC keys at index+64.
136 			 */
137 			memcpy(hk->kv_mic, k->wk_txmic, sizeof(hk->kv_mic));
138 			KEYPRINTF(sc, k->wk_keyix, hk, zerobssid);
139 			if (!ath_hal_keyset(ah, k->wk_keyix, hk, zerobssid))
140 				return 0;
141 
142 			memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
143 			KEYPRINTF(sc, k->wk_keyix+32, hk, mac);
144 			/* XXX delete tx key on failure? */
145 			return ath_hal_keyset(ah, k->wk_keyix+32, hk, mac);
146 		} else {
147 			/*
148 			 * Room for both TX+RX MIC keys in one key cache
149 			 * slot, just set key at the first index; the hal
150 			 * will handle the rest.
151 			 */
152 			memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
153 			memcpy(hk->kv_txmic, k->wk_txmic, sizeof(hk->kv_txmic));
154 			KEYPRINTF(sc, k->wk_keyix, hk, mac);
155 			return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
156 		}
157 	} else if (k->wk_flags & IEEE80211_KEY_XMIT) {
158 		if (sc->sc_splitmic) {
159 			/*
160 			 * NB: must pass MIC key in expected location when
161 			 * the keycache only holds one MIC key per entry.
162 			 */
163 			memcpy(hk->kv_mic, k->wk_txmic, sizeof(hk->kv_txmic));
164 		} else
165 			memcpy(hk->kv_txmic, k->wk_txmic, sizeof(hk->kv_txmic));
166 		KEYPRINTF(sc, k->wk_keyix, hk, mac);
167 		return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
168 	} else if (k->wk_flags & IEEE80211_KEY_RECV) {
169 		memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
170 		KEYPRINTF(sc, k->wk_keyix, hk, mac);
171 		return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
172 	}
173 	return 0;
174 #undef IEEE80211_KEY_XR
175 }
176 
177 /*
178  * Set a net80211 key into the hardware.  This handles the
179  * potential distribution of key state to multiple key
180  * cache slots for TKIP with hardware MIC support.
181  */
182 int
183 ath_keyset(struct ath_softc *sc, struct ieee80211vap *vap,
184 	const struct ieee80211_key *k,
185 	struct ieee80211_node *bss)
186 {
187 	static const u_int8_t ciphermap[] = {
188 		HAL_CIPHER_WEP,		/* IEEE80211_CIPHER_WEP */
189 		HAL_CIPHER_TKIP,	/* IEEE80211_CIPHER_TKIP */
190 		HAL_CIPHER_AES_OCB,	/* IEEE80211_CIPHER_AES_OCB */
191 		HAL_CIPHER_AES_CCM,	/* IEEE80211_CIPHER_AES_CCM */
192 		(u_int8_t) -1,		/* 4 is not allocated */
193 		HAL_CIPHER_CKIP,	/* IEEE80211_CIPHER_CKIP */
194 		HAL_CIPHER_CLR,		/* IEEE80211_CIPHER_NONE */
195 	};
196 	struct ath_hal *ah = sc->sc_ah;
197 	const struct ieee80211_cipher *cip = k->wk_cipher;
198 	u_int8_t gmac[IEEE80211_ADDR_LEN];
199 	const u_int8_t *mac;
200 	HAL_KEYVAL hk;
201 	int ret;
202 
203 	memset(&hk, 0, sizeof(hk));
204 	/*
205 	 * Software crypto uses a "clear key" so non-crypto
206 	 * state kept in the key cache are maintained and
207 	 * so that rx frames have an entry to match.
208 	 */
209 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) {
210 		KASSERT(cip->ic_cipher < nitems(ciphermap),
211 			("invalid cipher type %u", cip->ic_cipher));
212 		hk.kv_type = ciphermap[cip->ic_cipher];
213 		hk.kv_len = k->wk_keylen;
214 		memcpy(hk.kv_val, k->wk_key, k->wk_keylen);
215 	} else
216 		hk.kv_type = HAL_CIPHER_CLR;
217 
218 	/*
219 	 * If we're installing a clear cipher key and
220 	 * the hardware doesn't support that, just succeed.
221 	 * Leave it up to the net80211 layer to figure it out.
222 	 */
223 	if (hk.kv_type == HAL_CIPHER_CLR && sc->sc_hasclrkey == 0) {
224 		return (1);
225 	}
226 
227 	/*
228 	 * XXX TODO: check this:
229 	 *
230 	 * Group keys on hardware that supports multicast frame
231 	 * key search should only be done in adhoc/hostap mode,
232 	 * not STA mode.
233 	 *
234 	 * XXX TODO: what about mesh, tdma?
235 	 */
236 #if 0
237 	if ((vap->iv_opmode == IEEE80211_M_HOSTAP ||
238 	     vap->iv_opmode == IEEE80211_M_IBSS) &&
239 #else
240 	if (
241 #endif
242 	    (k->wk_flags & IEEE80211_KEY_GROUP) &&
243 	    sc->sc_mcastkey) {
244 		/*
245 		 * Group keys on hardware that supports multicast frame
246 		 * key search use a MAC that is the sender's address with
247 		 * the multicast bit set instead of the app-specified address.
248 		 */
249 		IEEE80211_ADDR_COPY(gmac, bss->ni_macaddr);
250 		gmac[0] |= 0x01;
251 		mac = gmac;
252 	} else
253 		mac = k->wk_macaddr;
254 
255 	ATH_LOCK(sc);
256 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
257 	if (hk.kv_type == HAL_CIPHER_TKIP &&
258 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
259 		ret = ath_keyset_tkip(sc, k, &hk, mac);
260 	} else {
261 		KEYPRINTF(sc, k->wk_keyix, &hk, mac);
262 		ret = ath_hal_keyset(ah, k->wk_keyix, &hk, mac);
263 	}
264 	ath_power_restore_power_state(sc);
265 	ATH_UNLOCK(sc);
266 
267 	return (ret);
268 }
269 
270 /*
271  * Allocate tx/rx key slots for TKIP.  We allocate two slots for
272  * each key, one for decrypt/encrypt and the other for the MIC.
273  */
274 static u_int16_t
275 key_alloc_2pair(struct ath_softc *sc,
276 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
277 {
278 	u_int i, keyix;
279 
280 	KASSERT(sc->sc_splitmic, ("key cache !split"));
281 	/* XXX could optimize */
282 	for (i = 0; i < nitems(sc->sc_keymap)/4; i++) {
283 		u_int8_t b = sc->sc_keymap[i];
284 		if (b != 0xff) {
285 			/*
286 			 * One or more slots in this byte are free.
287 			 */
288 			keyix = i*NBBY;
289 			while (b & 1) {
290 		again:
291 				keyix++;
292 				b >>= 1;
293 			}
294 			/* XXX IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV */
295 			if (isset(sc->sc_keymap, keyix+32) ||
296 			    isset(sc->sc_keymap, keyix+64) ||
297 			    isset(sc->sc_keymap, keyix+32+64)) {
298 				/* full pair unavailable */
299 				/* XXX statistic */
300 				if (keyix == (i+1)*NBBY) {
301 					/* no slots were appropriate, advance */
302 					continue;
303 				}
304 				goto again;
305 			}
306 			setbit(sc->sc_keymap, keyix);
307 			setbit(sc->sc_keymap, keyix+64);
308 			setbit(sc->sc_keymap, keyix+32);
309 			setbit(sc->sc_keymap, keyix+32+64);
310 			DPRINTF(sc, ATH_DEBUG_KEYCACHE,
311 				"%s: key pair %u,%u %u,%u\n",
312 				__func__, keyix, keyix+64,
313 				keyix+32, keyix+32+64);
314 			*txkeyix = keyix;
315 			*rxkeyix = keyix+32;
316 			return 1;
317 		}
318 	}
319 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of pair space\n", __func__);
320 	return 0;
321 }
322 
323 /*
324  * Allocate tx/rx key slots for TKIP.  We allocate two slots for
325  * each key, one for decrypt/encrypt and the other for the MIC.
326  */
327 static u_int16_t
328 key_alloc_pair(struct ath_softc *sc,
329 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
330 {
331 	u_int i, keyix;
332 
333 	KASSERT(!sc->sc_splitmic, ("key cache split"));
334 	/* XXX could optimize */
335 	for (i = 0; i < nitems(sc->sc_keymap)/4; i++) {
336 		u_int8_t b = sc->sc_keymap[i];
337 		if (b != 0xff) {
338 			/*
339 			 * One or more slots in this byte are free.
340 			 */
341 			keyix = i*NBBY;
342 			while (b & 1) {
343 		again:
344 				keyix++;
345 				b >>= 1;
346 			}
347 			if (isset(sc->sc_keymap, keyix+64)) {
348 				/* full pair unavailable */
349 				/* XXX statistic */
350 				if (keyix == (i+1)*NBBY) {
351 					/* no slots were appropriate, advance */
352 					continue;
353 				}
354 				goto again;
355 			}
356 			setbit(sc->sc_keymap, keyix);
357 			setbit(sc->sc_keymap, keyix+64);
358 			DPRINTF(sc, ATH_DEBUG_KEYCACHE,
359 				"%s: key pair %u,%u\n",
360 				__func__, keyix, keyix+64);
361 			*txkeyix = *rxkeyix = keyix;
362 			return 1;
363 		}
364 	}
365 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of pair space\n", __func__);
366 	return 0;
367 }
368 
369 /*
370  * Allocate a single key cache slot.
371  */
372 static int
373 key_alloc_single(struct ath_softc *sc,
374 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
375 {
376 	u_int i, keyix;
377 
378 	if (sc->sc_hasclrkey == 0) {
379 		/*
380 		 * Map to slot 0 for the AR5210.
381 		 */
382 		*txkeyix = *rxkeyix = 0;
383 		return (1);
384 	}
385 
386 	/* XXX try i,i+32,i+64,i+32+64 to minimize key pair conflicts */
387 	for (i = 0; i < nitems(sc->sc_keymap); i++) {
388 		u_int8_t b = sc->sc_keymap[i];
389 		if (b != 0xff) {
390 			/*
391 			 * One or more slots are free.
392 			 */
393 			keyix = i*NBBY;
394 			while (b & 1)
395 				keyix++, b >>= 1;
396 			setbit(sc->sc_keymap, keyix);
397 			DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: key %u\n",
398 				__func__, keyix);
399 			*txkeyix = *rxkeyix = keyix;
400 			return 1;
401 		}
402 	}
403 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of space\n", __func__);
404 	return 0;
405 }
406 
407 /*
408  * Allocate one or more key cache slots for a uniacst key.  The
409  * key itself is needed only to identify the cipher.  For hardware
410  * TKIP with split cipher+MIC keys we allocate two key cache slot
411  * pairs so that we can setup separate TX and RX MIC keys.  Note
412  * that the MIC key for a TKIP key at slot i is assumed by the
413  * hardware to be at slot i+64.  This limits TKIP keys to the first
414  * 64 entries.
415  */
416 int
417 ath_key_alloc(struct ieee80211vap *vap, struct ieee80211_key *k,
418 	ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
419 {
420 	struct ath_softc *sc = vap->iv_ic->ic_softc;
421 
422 	/*
423 	 * Group key allocation must be handled specially for
424 	 * parts that do not support multicast key cache search
425 	 * functionality.  For those parts the key id must match
426 	 * the h/w key index so lookups find the right key.  On
427 	 * parts w/ the key search facility we install the sender's
428 	 * mac address (with the high bit set) and let the hardware
429 	 * find the key w/o using the key id.  This is preferred as
430 	 * it permits us to support multiple users for adhoc and/or
431 	 * multi-station operation.
432 	 */
433 	if (k->wk_keyix != IEEE80211_KEYIX_NONE) {
434 		/*
435 		 * Only global keys should have key index assigned.
436 		 */
437 		if (!(&vap->iv_nw_keys[0] <= k &&
438 		      k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])) {
439 			/* should not happen */
440 			DPRINTF(sc, ATH_DEBUG_KEYCACHE,
441 				"%s: bogus group key\n", __func__);
442 			return 0;
443 		}
444 		if (vap->iv_opmode != IEEE80211_M_HOSTAP ||
445 		    !(k->wk_flags & IEEE80211_KEY_GROUP) ||
446 		    !sc->sc_mcastkey) {
447 			/*
448 			 * XXX we pre-allocate the global keys so
449 			 * have no way to check if they've already
450 			 * been allocated.
451 			 */
452 			*keyix = *rxkeyix =
453 			    ieee80211_crypto_get_key_wepidx(vap, k);
454 			return 1;
455 		}
456 		/*
457 		 * Group key and device supports multicast key search.
458 		 */
459 		k->wk_keyix = IEEE80211_KEYIX_NONE;
460 	}
461 
462 	/*
463 	 * We allocate two pair for TKIP when using the h/w to do
464 	 * the MIC.  For everything else, including software crypto,
465 	 * we allocate a single entry.  Note that s/w crypto requires
466 	 * a pass-through slot on the 5211 and 5212.  The 5210 does
467 	 * not support pass-through cache entries and we map all
468 	 * those requests to slot 0.
469 	 */
470 	if (k->wk_flags & IEEE80211_KEY_SWCRYPT) {
471 		return key_alloc_single(sc, keyix, rxkeyix);
472 	} else if (k->wk_cipher->ic_cipher == IEEE80211_CIPHER_TKIP &&
473 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
474 		if (sc->sc_splitmic)
475 			return key_alloc_2pair(sc, keyix, rxkeyix);
476 		else
477 			return key_alloc_pair(sc, keyix, rxkeyix);
478 	} else {
479 		return key_alloc_single(sc, keyix, rxkeyix);
480 	}
481 }
482 
483 /*
484  * Delete an entry in the key cache allocated by ath_key_alloc.
485  */
486 int
487 ath_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
488 {
489 	struct ath_softc *sc = vap->iv_ic->ic_softc;
490 	struct ath_hal *ah = sc->sc_ah;
491 	const struct ieee80211_cipher *cip = k->wk_cipher;
492 	u_int keyix = k->wk_keyix;
493 
494 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: delete key %u\n", __func__, keyix);
495 
496 	ATH_LOCK(sc);
497 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
498 	ath_hal_keyreset(ah, keyix);
499 	/*
500 	 * Handle split tx/rx keying required for TKIP with h/w MIC.
501 	 */
502 	if (cip->ic_cipher == IEEE80211_CIPHER_TKIP &&
503 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0 && sc->sc_splitmic)
504 		ath_hal_keyreset(ah, keyix+32);		/* RX key */
505 	if (keyix >= IEEE80211_WEP_NKID) {
506 		/*
507 		 * Don't touch keymap entries for global keys so
508 		 * they are never considered for dynamic allocation.
509 		 */
510 		clrbit(sc->sc_keymap, keyix);
511 		if (cip->ic_cipher == IEEE80211_CIPHER_TKIP &&
512 		    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
513 			clrbit(sc->sc_keymap, keyix+64);	/* TX key MIC */
514 			if (sc->sc_splitmic) {
515 				/* +32 for RX key, +32+64 for RX key MIC */
516 				clrbit(sc->sc_keymap, keyix+32);
517 				clrbit(sc->sc_keymap, keyix+32+64);
518 			}
519 		}
520 	}
521 	ath_power_restore_power_state(sc);
522 	ATH_UNLOCK(sc);
523 	return 1;
524 }
525 
526 /*
527  * Set the key cache contents for the specified key.  Key cache
528  * slot(s) must already have been allocated by ath_key_alloc.
529  */
530 int
531 ath_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k)
532 {
533 	struct ath_softc *sc = vap->iv_ic->ic_softc;
534 
535 	return ath_keyset(sc, vap, k, vap->iv_bss);
536 }
537