xref: /freebsd/sys/dev/ath/if_ath_keycache.c (revision 9ecd54f24fe9fa373e07c9fd7c052deb2188f545)
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 
82 #ifdef ATH_DEBUG
83 static void
84 ath_keyprint(struct ath_softc *sc, const char *tag, u_int ix,
85 	const HAL_KEYVAL *hk, const u_int8_t mac[IEEE80211_ADDR_LEN])
86 {
87 	static const char *ciphers[] = {
88 		"WEP",
89 		"AES-OCB",
90 		"AES-CCM",
91 		"CKIP",
92 		"TKIP",
93 		"CLR",
94 	};
95 	int i, n;
96 
97 	printf("%s: [%02u] %-7s ", tag, ix, ciphers[hk->kv_type]);
98 	for (i = 0, n = hk->kv_len; i < n; i++)
99 		printf("%02x", hk->kv_val[i]);
100 	printf(" mac %s", ether_sprintf(mac));
101 	if (hk->kv_type == HAL_CIPHER_TKIP) {
102 		printf(" %s ", sc->sc_splitmic ? "mic" : "rxmic");
103 		for (i = 0; i < sizeof(hk->kv_mic); i++)
104 			printf("%02x", hk->kv_mic[i]);
105 		if (!sc->sc_splitmic) {
106 			printf(" txmic ");
107 			for (i = 0; i < sizeof(hk->kv_txmic); i++)
108 				printf("%02x", hk->kv_txmic[i]);
109 		}
110 	}
111 	printf("\n");
112 }
113 #endif
114 
115 /*
116  * Set a TKIP key into the hardware.  This handles the
117  * potential distribution of key state to multiple key
118  * cache slots for TKIP.
119  */
120 static int
121 ath_keyset_tkip(struct ath_softc *sc, const struct ieee80211_key *k,
122 	HAL_KEYVAL *hk, const u_int8_t mac[IEEE80211_ADDR_LEN])
123 {
124 #define	IEEE80211_KEY_XR	(IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV)
125 	static const u_int8_t zerobssid[IEEE80211_ADDR_LEN];
126 	struct ath_hal *ah = sc->sc_ah;
127 
128 	KASSERT(k->wk_cipher->ic_cipher == IEEE80211_CIPHER_TKIP,
129 		("got a non-TKIP key, cipher %u", k->wk_cipher->ic_cipher));
130 	if ((k->wk_flags & IEEE80211_KEY_XR) == IEEE80211_KEY_XR) {
131 		if (sc->sc_splitmic) {
132 			/*
133 			 * TX key goes at first index, RX key at the rx index.
134 			 * The hal handles the MIC keys at index+64.
135 			 */
136 			memcpy(hk->kv_mic, k->wk_txmic, sizeof(hk->kv_mic));
137 			KEYPRINTF(sc, k->wk_keyix, hk, zerobssid);
138 			if (!ath_hal_keyset(ah, k->wk_keyix, hk, zerobssid))
139 				return 0;
140 
141 			memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
142 			KEYPRINTF(sc, k->wk_keyix+32, hk, mac);
143 			/* XXX delete tx key on failure? */
144 			return ath_hal_keyset(ah, k->wk_keyix+32, hk, mac);
145 		} else {
146 			/*
147 			 * Room for both TX+RX MIC keys in one key cache
148 			 * slot, just set key at the first index; the hal
149 			 * will handle the rest.
150 			 */
151 			memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
152 			memcpy(hk->kv_txmic, k->wk_txmic, sizeof(hk->kv_txmic));
153 			KEYPRINTF(sc, k->wk_keyix, hk, mac);
154 			return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
155 		}
156 	} else if (k->wk_flags & IEEE80211_KEY_XMIT) {
157 		if (sc->sc_splitmic) {
158 			/*
159 			 * NB: must pass MIC key in expected location when
160 			 * the keycache only holds one MIC key per entry.
161 			 */
162 			memcpy(hk->kv_mic, k->wk_txmic, sizeof(hk->kv_txmic));
163 		} else
164 			memcpy(hk->kv_txmic, k->wk_txmic, sizeof(hk->kv_txmic));
165 		KEYPRINTF(sc, k->wk_keyix, hk, mac);
166 		return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
167 	} else if (k->wk_flags & IEEE80211_KEY_RECV) {
168 		memcpy(hk->kv_mic, k->wk_rxmic, sizeof(hk->kv_mic));
169 		KEYPRINTF(sc, k->wk_keyix, hk, mac);
170 		return ath_hal_keyset(ah, k->wk_keyix, hk, mac);
171 	}
172 	return 0;
173 #undef IEEE80211_KEY_XR
174 }
175 
176 /*
177  * Set a net80211 key into the hardware.  This handles the
178  * potential distribution of key state to multiple key
179  * cache slots for TKIP with hardware MIC support.
180  */
181 int
182 ath_keyset(struct ath_softc *sc, struct ieee80211vap *vap,
183 	const struct ieee80211_key *k,
184 	struct ieee80211_node *bss)
185 {
186 #define	N(a)	(sizeof(a)/sizeof(a[0]))
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 
202 	memset(&hk, 0, sizeof(hk));
203 	/*
204 	 * Software crypto uses a "clear key" so non-crypto
205 	 * state kept in the key cache are maintained and
206 	 * so that rx frames have an entry to match.
207 	 */
208 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) {
209 		KASSERT(cip->ic_cipher < N(ciphermap),
210 			("invalid cipher type %u", cip->ic_cipher));
211 		hk.kv_type = ciphermap[cip->ic_cipher];
212 		hk.kv_len = k->wk_keylen;
213 		memcpy(hk.kv_val, k->wk_key, k->wk_keylen);
214 	} else
215 		hk.kv_type = HAL_CIPHER_CLR;
216 
217 	/*
218 	 * If we're installing a clear cipher key and
219 	 * the hardware doesn't support that, just succeed.
220 	 * Leave it up to the net80211 layer to figure it out.
221 	 */
222 	if (hk.kv_type == HAL_CIPHER_CLR && sc->sc_hasclrkey == 0) {
223 		return (1);
224 	}
225 
226 	/*
227 	 * XXX TODO: check this:
228 	 *
229 	 * Group keys on hardware that supports multicast frame
230 	 * key search should only be done in adhoc/hostap mode,
231 	 * not STA mode.
232 	 *
233 	 * XXX TODO: what about mesh, tdma?
234 	 */
235 #if 0
236 	if ((vap->iv_opmode == IEEE80211_M_HOSTAP ||
237 	     vap->iv_opmode == IEEE80211_M_IBSS) &&
238 #else
239 	if (
240 #endif
241 	    (k->wk_flags & IEEE80211_KEY_GROUP) &&
242 	    sc->sc_mcastkey) {
243 		/*
244 		 * Group keys on hardware that supports multicast frame
245 		 * key search use a MAC that is the sender's address with
246 		 * the multicast bit set instead of the app-specified address.
247 		 */
248 		IEEE80211_ADDR_COPY(gmac, bss->ni_macaddr);
249 		gmac[0] |= 0x01;
250 		mac = gmac;
251 	} else
252 		mac = k->wk_macaddr;
253 
254 	if (hk.kv_type == HAL_CIPHER_TKIP &&
255 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
256 		return ath_keyset_tkip(sc, k, &hk, mac);
257 	} else {
258 		KEYPRINTF(sc, k->wk_keyix, &hk, mac);
259 		return ath_hal_keyset(ah, k->wk_keyix, &hk, mac);
260 	}
261 #undef N
262 }
263 
264 /*
265  * Allocate tx/rx key slots for TKIP.  We allocate two slots for
266  * each key, one for decrypt/encrypt and the other for the MIC.
267  */
268 static u_int16_t
269 key_alloc_2pair(struct ath_softc *sc,
270 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
271 {
272 #define	N(a)	(sizeof(a)/sizeof(a[0]))
273 	u_int i, keyix;
274 
275 	KASSERT(sc->sc_splitmic, ("key cache !split"));
276 	/* XXX could optimize */
277 	for (i = 0; i < N(sc->sc_keymap)/4; i++) {
278 		u_int8_t b = sc->sc_keymap[i];
279 		if (b != 0xff) {
280 			/*
281 			 * One or more slots in this byte are free.
282 			 */
283 			keyix = i*NBBY;
284 			while (b & 1) {
285 		again:
286 				keyix++;
287 				b >>= 1;
288 			}
289 			/* XXX IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV */
290 			if (isset(sc->sc_keymap, keyix+32) ||
291 			    isset(sc->sc_keymap, keyix+64) ||
292 			    isset(sc->sc_keymap, keyix+32+64)) {
293 				/* full pair unavailable */
294 				/* XXX statistic */
295 				if (keyix == (i+1)*NBBY) {
296 					/* no slots were appropriate, advance */
297 					continue;
298 				}
299 				goto again;
300 			}
301 			setbit(sc->sc_keymap, keyix);
302 			setbit(sc->sc_keymap, keyix+64);
303 			setbit(sc->sc_keymap, keyix+32);
304 			setbit(sc->sc_keymap, keyix+32+64);
305 			DPRINTF(sc, ATH_DEBUG_KEYCACHE,
306 				"%s: key pair %u,%u %u,%u\n",
307 				__func__, keyix, keyix+64,
308 				keyix+32, keyix+32+64);
309 			*txkeyix = keyix;
310 			*rxkeyix = keyix+32;
311 			return 1;
312 		}
313 	}
314 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of pair space\n", __func__);
315 	return 0;
316 #undef N
317 }
318 
319 /*
320  * Allocate tx/rx key slots for TKIP.  We allocate two slots for
321  * each key, one for decrypt/encrypt and the other for the MIC.
322  */
323 static u_int16_t
324 key_alloc_pair(struct ath_softc *sc,
325 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
326 {
327 #define	N(a)	(sizeof(a)/sizeof(a[0]))
328 	u_int i, keyix;
329 
330 	KASSERT(!sc->sc_splitmic, ("key cache split"));
331 	/* XXX could optimize */
332 	for (i = 0; i < N(sc->sc_keymap)/4; i++) {
333 		u_int8_t b = sc->sc_keymap[i];
334 		if (b != 0xff) {
335 			/*
336 			 * One or more slots in this byte are free.
337 			 */
338 			keyix = i*NBBY;
339 			while (b & 1) {
340 		again:
341 				keyix++;
342 				b >>= 1;
343 			}
344 			if (isset(sc->sc_keymap, keyix+64)) {
345 				/* full pair unavailable */
346 				/* XXX statistic */
347 				if (keyix == (i+1)*NBBY) {
348 					/* no slots were appropriate, advance */
349 					continue;
350 				}
351 				goto again;
352 			}
353 			setbit(sc->sc_keymap, keyix);
354 			setbit(sc->sc_keymap, keyix+64);
355 			DPRINTF(sc, ATH_DEBUG_KEYCACHE,
356 				"%s: key pair %u,%u\n",
357 				__func__, keyix, keyix+64);
358 			*txkeyix = *rxkeyix = keyix;
359 			return 1;
360 		}
361 	}
362 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of pair space\n", __func__);
363 	return 0;
364 #undef N
365 }
366 
367 /*
368  * Allocate a single key cache slot.
369  */
370 static int
371 key_alloc_single(struct ath_softc *sc,
372 	ieee80211_keyix *txkeyix, ieee80211_keyix *rxkeyix)
373 {
374 #define	N(a)	(sizeof(a)/sizeof(a[0]))
375 	u_int i, keyix;
376 
377 	if (sc->sc_hasclrkey == 0) {
378 		/*
379 		 * Map to slot 0 for the AR5210.
380 		 */
381 		*txkeyix = *rxkeyix = 0;
382 		return (1);
383 	}
384 
385 	/* XXX try i,i+32,i+64,i+32+64 to minimize key pair conflicts */
386 	for (i = 0; i < N(sc->sc_keymap); i++) {
387 		u_int8_t b = sc->sc_keymap[i];
388 		if (b != 0xff) {
389 			/*
390 			 * One or more slots are free.
391 			 */
392 			keyix = i*NBBY;
393 			while (b & 1)
394 				keyix++, b >>= 1;
395 			setbit(sc->sc_keymap, keyix);
396 			DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: key %u\n",
397 				__func__, keyix);
398 			*txkeyix = *rxkeyix = keyix;
399 			return 1;
400 		}
401 	}
402 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: out of space\n", __func__);
403 	return 0;
404 #undef N
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_ifp->if_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 = k - vap->iv_nw_keys;
453 			return 1;
454 		}
455 		/*
456 		 * Group key and device supports multicast key search.
457 		 */
458 		k->wk_keyix = IEEE80211_KEYIX_NONE;
459 	}
460 
461 	/*
462 	 * We allocate two pair for TKIP when using the h/w to do
463 	 * the MIC.  For everything else, including software crypto,
464 	 * we allocate a single entry.  Note that s/w crypto requires
465 	 * a pass-through slot on the 5211 and 5212.  The 5210 does
466 	 * not support pass-through cache entries and we map all
467 	 * those requests to slot 0.
468 	 */
469 	if (k->wk_flags & IEEE80211_KEY_SWCRYPT) {
470 		return key_alloc_single(sc, keyix, rxkeyix);
471 	} else if (k->wk_cipher->ic_cipher == IEEE80211_CIPHER_TKIP &&
472 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
473 		if (sc->sc_splitmic)
474 			return key_alloc_2pair(sc, keyix, rxkeyix);
475 		else
476 			return key_alloc_pair(sc, keyix, rxkeyix);
477 	} else {
478 		return key_alloc_single(sc, keyix, rxkeyix);
479 	}
480 }
481 
482 /*
483  * Delete an entry in the key cache allocated by ath_key_alloc.
484  */
485 int
486 ath_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
487 {
488 	struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;
489 	struct ath_hal *ah = sc->sc_ah;
490 	const struct ieee80211_cipher *cip = k->wk_cipher;
491 	u_int keyix = k->wk_keyix;
492 
493 	DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s: delete key %u\n", __func__, keyix);
494 
495 	ath_hal_keyreset(ah, keyix);
496 	/*
497 	 * Handle split tx/rx keying required for TKIP with h/w MIC.
498 	 */
499 	if (cip->ic_cipher == IEEE80211_CIPHER_TKIP &&
500 	    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0 && sc->sc_splitmic)
501 		ath_hal_keyreset(ah, keyix+32);		/* RX key */
502 	if (keyix >= IEEE80211_WEP_NKID) {
503 		/*
504 		 * Don't touch keymap entries for global keys so
505 		 * they are never considered for dynamic allocation.
506 		 */
507 		clrbit(sc->sc_keymap, keyix);
508 		if (cip->ic_cipher == IEEE80211_CIPHER_TKIP &&
509 		    (k->wk_flags & IEEE80211_KEY_SWMIC) == 0) {
510 			clrbit(sc->sc_keymap, keyix+64);	/* TX key MIC */
511 			if (sc->sc_splitmic) {
512 				/* +32 for RX key, +32+64 for RX key MIC */
513 				clrbit(sc->sc_keymap, keyix+32);
514 				clrbit(sc->sc_keymap, keyix+32+64);
515 			}
516 		}
517 	}
518 	return 1;
519 }
520 
521 /*
522  * Set the key cache contents for the specified key.  Key cache
523  * slot(s) must already have been allocated by ath_key_alloc.
524  */
525 int
526 ath_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k,
527 	const u_int8_t mac[IEEE80211_ADDR_LEN])
528 {
529 	struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;
530 
531 	return ath_keyset(sc, vap, k, vap->iv_bss);
532 }
533