xref: /linux/net/wireless/util.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
1 /*
2  * Wireless utility functions
3  *
4  * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/export.h>
7 #include <linux/bitops.h>
8 #include <linux/etherdevice.h>
9 #include <linux/slab.h>
10 #include <net/cfg80211.h>
11 #include <net/ip.h>
12 #include <net/dsfield.h>
13 #include "core.h"
14 
15 struct ieee80211_rate *
16 ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
17 			    u32 basic_rates, int bitrate)
18 {
19 	struct ieee80211_rate *result = &sband->bitrates[0];
20 	int i;
21 
22 	for (i = 0; i < sband->n_bitrates; i++) {
23 		if (!(basic_rates & BIT(i)))
24 			continue;
25 		if (sband->bitrates[i].bitrate > bitrate)
26 			continue;
27 		result = &sband->bitrates[i];
28 	}
29 
30 	return result;
31 }
32 EXPORT_SYMBOL(ieee80211_get_response_rate);
33 
34 int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)
35 {
36 	/* see 802.11 17.3.8.3.2 and Annex J
37 	 * there are overlapping channel numbers in 5GHz and 2GHz bands */
38 	if (chan <= 0)
39 		return 0; /* not supported */
40 	switch (band) {
41 	case IEEE80211_BAND_2GHZ:
42 		if (chan == 14)
43 			return 2484;
44 		else if (chan < 14)
45 			return 2407 + chan * 5;
46 		break;
47 	case IEEE80211_BAND_5GHZ:
48 		if (chan >= 182 && chan <= 196)
49 			return 4000 + chan * 5;
50 		else
51 			return 5000 + chan * 5;
52 		break;
53 	case IEEE80211_BAND_60GHZ:
54 		if (chan < 5)
55 			return 56160 + chan * 2160;
56 		break;
57 	default:
58 		;
59 	}
60 	return 0; /* not supported */
61 }
62 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
63 
64 int ieee80211_frequency_to_channel(int freq)
65 {
66 	/* see 802.11 17.3.8.3.2 and Annex J */
67 	if (freq == 2484)
68 		return 14;
69 	else if (freq < 2484)
70 		return (freq - 2407) / 5;
71 	else if (freq >= 4910 && freq <= 4980)
72 		return (freq - 4000) / 5;
73 	else if (freq <= 45000) /* DMG band lower limit */
74 		return (freq - 5000) / 5;
75 	else if (freq >= 58320 && freq <= 64800)
76 		return (freq - 56160) / 2160;
77 	else
78 		return 0;
79 }
80 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
81 
82 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
83 						  int freq)
84 {
85 	enum ieee80211_band band;
86 	struct ieee80211_supported_band *sband;
87 	int i;
88 
89 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
90 		sband = wiphy->bands[band];
91 
92 		if (!sband)
93 			continue;
94 
95 		for (i = 0; i < sband->n_channels; i++) {
96 			if (sband->channels[i].center_freq == freq)
97 				return &sband->channels[i];
98 		}
99 	}
100 
101 	return NULL;
102 }
103 EXPORT_SYMBOL(__ieee80211_get_channel);
104 
105 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
106 				     enum ieee80211_band band)
107 {
108 	int i, want;
109 
110 	switch (band) {
111 	case IEEE80211_BAND_5GHZ:
112 		want = 3;
113 		for (i = 0; i < sband->n_bitrates; i++) {
114 			if (sband->bitrates[i].bitrate == 60 ||
115 			    sband->bitrates[i].bitrate == 120 ||
116 			    sband->bitrates[i].bitrate == 240) {
117 				sband->bitrates[i].flags |=
118 					IEEE80211_RATE_MANDATORY_A;
119 				want--;
120 			}
121 		}
122 		WARN_ON(want);
123 		break;
124 	case IEEE80211_BAND_2GHZ:
125 		want = 7;
126 		for (i = 0; i < sband->n_bitrates; i++) {
127 			if (sband->bitrates[i].bitrate == 10) {
128 				sband->bitrates[i].flags |=
129 					IEEE80211_RATE_MANDATORY_B |
130 					IEEE80211_RATE_MANDATORY_G;
131 				want--;
132 			}
133 
134 			if (sband->bitrates[i].bitrate == 20 ||
135 			    sband->bitrates[i].bitrate == 55 ||
136 			    sband->bitrates[i].bitrate == 110 ||
137 			    sband->bitrates[i].bitrate == 60 ||
138 			    sband->bitrates[i].bitrate == 120 ||
139 			    sband->bitrates[i].bitrate == 240) {
140 				sband->bitrates[i].flags |=
141 					IEEE80211_RATE_MANDATORY_G;
142 				want--;
143 			}
144 
145 			if (sband->bitrates[i].bitrate != 10 &&
146 			    sband->bitrates[i].bitrate != 20 &&
147 			    sband->bitrates[i].bitrate != 55 &&
148 			    sband->bitrates[i].bitrate != 110)
149 				sband->bitrates[i].flags |=
150 					IEEE80211_RATE_ERP_G;
151 		}
152 		WARN_ON(want != 0 && want != 3 && want != 6);
153 		break;
154 	case IEEE80211_BAND_60GHZ:
155 		/* check for mandatory HT MCS 1..4 */
156 		WARN_ON(!sband->ht_cap.ht_supported);
157 		WARN_ON((sband->ht_cap.mcs.rx_mask[0] & 0x1e) != 0x1e);
158 		break;
159 	case IEEE80211_NUM_BANDS:
160 		WARN_ON(1);
161 		break;
162 	}
163 }
164 
165 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
166 {
167 	enum ieee80211_band band;
168 
169 	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
170 		if (wiphy->bands[band])
171 			set_mandatory_flags_band(wiphy->bands[band], band);
172 }
173 
174 bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
175 {
176 	int i;
177 	for (i = 0; i < wiphy->n_cipher_suites; i++)
178 		if (cipher == wiphy->cipher_suites[i])
179 			return true;
180 	return false;
181 }
182 
183 int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
184 				   struct key_params *params, int key_idx,
185 				   bool pairwise, const u8 *mac_addr)
186 {
187 	if (key_idx > 5)
188 		return -EINVAL;
189 
190 	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
191 		return -EINVAL;
192 
193 	if (pairwise && !mac_addr)
194 		return -EINVAL;
195 
196 	/*
197 	 * Disallow pairwise keys with non-zero index unless it's WEP
198 	 * or a vendor specific cipher (because current deployments use
199 	 * pairwise WEP keys with non-zero indices and for vendor specific
200 	 * ciphers this should be validated in the driver or hardware level
201 	 * - but 802.11i clearly specifies to use zero)
202 	 */
203 	if (pairwise && key_idx &&
204 	    ((params->cipher == WLAN_CIPHER_SUITE_TKIP) ||
205 	     (params->cipher == WLAN_CIPHER_SUITE_CCMP) ||
206 	     (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC)))
207 		return -EINVAL;
208 
209 	switch (params->cipher) {
210 	case WLAN_CIPHER_SUITE_WEP40:
211 		if (params->key_len != WLAN_KEY_LEN_WEP40)
212 			return -EINVAL;
213 		break;
214 	case WLAN_CIPHER_SUITE_TKIP:
215 		if (params->key_len != WLAN_KEY_LEN_TKIP)
216 			return -EINVAL;
217 		break;
218 	case WLAN_CIPHER_SUITE_CCMP:
219 		if (params->key_len != WLAN_KEY_LEN_CCMP)
220 			return -EINVAL;
221 		break;
222 	case WLAN_CIPHER_SUITE_WEP104:
223 		if (params->key_len != WLAN_KEY_LEN_WEP104)
224 			return -EINVAL;
225 		break;
226 	case WLAN_CIPHER_SUITE_AES_CMAC:
227 		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
228 			return -EINVAL;
229 		break;
230 	default:
231 		/*
232 		 * We don't know anything about this algorithm,
233 		 * allow using it -- but the driver must check
234 		 * all parameters! We still check below whether
235 		 * or not the driver supports this algorithm,
236 		 * of course.
237 		 */
238 		break;
239 	}
240 
241 	if (params->seq) {
242 		switch (params->cipher) {
243 		case WLAN_CIPHER_SUITE_WEP40:
244 		case WLAN_CIPHER_SUITE_WEP104:
245 			/* These ciphers do not use key sequence */
246 			return -EINVAL;
247 		case WLAN_CIPHER_SUITE_TKIP:
248 		case WLAN_CIPHER_SUITE_CCMP:
249 		case WLAN_CIPHER_SUITE_AES_CMAC:
250 			if (params->seq_len != 6)
251 				return -EINVAL;
252 			break;
253 		}
254 	}
255 
256 	if (!cfg80211_supported_cipher_suite(&rdev->wiphy, params->cipher))
257 		return -EINVAL;
258 
259 	return 0;
260 }
261 
262 unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
263 {
264 	unsigned int hdrlen = 24;
265 
266 	if (ieee80211_is_data(fc)) {
267 		if (ieee80211_has_a4(fc))
268 			hdrlen = 30;
269 		if (ieee80211_is_data_qos(fc)) {
270 			hdrlen += IEEE80211_QOS_CTL_LEN;
271 			if (ieee80211_has_order(fc))
272 				hdrlen += IEEE80211_HT_CTL_LEN;
273 		}
274 		goto out;
275 	}
276 
277 	if (ieee80211_is_ctl(fc)) {
278 		/*
279 		 * ACK and CTS are 10 bytes, all others 16. To see how
280 		 * to get this condition consider
281 		 *   subtype mask:   0b0000000011110000 (0x00F0)
282 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
283 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
284 		 *   bits that matter:         ^^^      (0x00E0)
285 		 *   value of those: 0b0000000011000000 (0x00C0)
286 		 */
287 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
288 			hdrlen = 10;
289 		else
290 			hdrlen = 16;
291 	}
292 out:
293 	return hdrlen;
294 }
295 EXPORT_SYMBOL(ieee80211_hdrlen);
296 
297 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
298 {
299 	const struct ieee80211_hdr *hdr =
300 			(const struct ieee80211_hdr *)skb->data;
301 	unsigned int hdrlen;
302 
303 	if (unlikely(skb->len < 10))
304 		return 0;
305 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
306 	if (unlikely(hdrlen > skb->len))
307 		return 0;
308 	return hdrlen;
309 }
310 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
311 
312 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
313 {
314 	int ae = meshhdr->flags & MESH_FLAGS_AE;
315 	/* 7.1.3.5a.2 */
316 	switch (ae) {
317 	case 0:
318 		return 6;
319 	case MESH_FLAGS_AE_A4:
320 		return 12;
321 	case MESH_FLAGS_AE_A5_A6:
322 		return 18;
323 	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
324 		return 24;
325 	default:
326 		return 6;
327 	}
328 }
329 
330 int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
331 			   enum nl80211_iftype iftype)
332 {
333 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
334 	u16 hdrlen, ethertype;
335 	u8 *payload;
336 	u8 dst[ETH_ALEN];
337 	u8 src[ETH_ALEN] __aligned(2);
338 
339 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
340 		return -1;
341 
342 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
343 
344 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
345 	 * header
346 	 * IEEE 802.11 address fields:
347 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
348 	 *   0     0   DA    SA    BSSID n/a
349 	 *   0     1   DA    BSSID SA    n/a
350 	 *   1     0   BSSID SA    DA    n/a
351 	 *   1     1   RA    TA    DA    SA
352 	 */
353 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
354 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
355 
356 	switch (hdr->frame_control &
357 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
358 	case cpu_to_le16(IEEE80211_FCTL_TODS):
359 		if (unlikely(iftype != NL80211_IFTYPE_AP &&
360 			     iftype != NL80211_IFTYPE_AP_VLAN &&
361 			     iftype != NL80211_IFTYPE_P2P_GO))
362 			return -1;
363 		break;
364 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
365 		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
366 			     iftype != NL80211_IFTYPE_MESH_POINT &&
367 			     iftype != NL80211_IFTYPE_AP_VLAN &&
368 			     iftype != NL80211_IFTYPE_STATION))
369 			return -1;
370 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
371 			struct ieee80211s_hdr *meshdr =
372 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
373 			/* make sure meshdr->flags is on the linear part */
374 			if (!pskb_may_pull(skb, hdrlen + 1))
375 				return -1;
376 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
377 				skb_copy_bits(skb, hdrlen +
378 					offsetof(struct ieee80211s_hdr, eaddr1),
379 				       	dst, ETH_ALEN);
380 				skb_copy_bits(skb, hdrlen +
381 					offsetof(struct ieee80211s_hdr, eaddr2),
382 				        src, ETH_ALEN);
383 			}
384 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
385 		}
386 		break;
387 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
388 		if ((iftype != NL80211_IFTYPE_STATION &&
389 		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
390 		     iftype != NL80211_IFTYPE_MESH_POINT) ||
391 		    (is_multicast_ether_addr(dst) &&
392 		     ether_addr_equal(src, addr)))
393 			return -1;
394 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
395 			struct ieee80211s_hdr *meshdr =
396 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
397 			/* make sure meshdr->flags is on the linear part */
398 			if (!pskb_may_pull(skb, hdrlen + 1))
399 				return -1;
400 			if (meshdr->flags & MESH_FLAGS_AE_A4)
401 				skb_copy_bits(skb, hdrlen +
402 					offsetof(struct ieee80211s_hdr, eaddr1),
403 					src, ETH_ALEN);
404 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
405 		}
406 		break;
407 	case cpu_to_le16(0):
408 		if (iftype != NL80211_IFTYPE_ADHOC &&
409 		    iftype != NL80211_IFTYPE_STATION)
410 				return -1;
411 		break;
412 	}
413 
414 	if (!pskb_may_pull(skb, hdrlen + 8))
415 		return -1;
416 
417 	payload = skb->data + hdrlen;
418 	ethertype = (payload[6] << 8) | payload[7];
419 
420 	if (likely((ether_addr_equal(payload, rfc1042_header) &&
421 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
422 		   ether_addr_equal(payload, bridge_tunnel_header))) {
423 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
424 		 * replace EtherType */
425 		skb_pull(skb, hdrlen + 6);
426 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
427 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
428 	} else {
429 		struct ethhdr *ehdr;
430 		__be16 len;
431 
432 		skb_pull(skb, hdrlen);
433 		len = htons(skb->len);
434 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
435 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
436 		memcpy(ehdr->h_source, src, ETH_ALEN);
437 		ehdr->h_proto = len;
438 	}
439 	return 0;
440 }
441 EXPORT_SYMBOL(ieee80211_data_to_8023);
442 
443 int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
444 			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
445 {
446 	struct ieee80211_hdr hdr;
447 	u16 hdrlen, ethertype;
448 	__le16 fc;
449 	const u8 *encaps_data;
450 	int encaps_len, skip_header_bytes;
451 	int nh_pos, h_pos;
452 	int head_need;
453 
454 	if (unlikely(skb->len < ETH_HLEN))
455 		return -EINVAL;
456 
457 	nh_pos = skb_network_header(skb) - skb->data;
458 	h_pos = skb_transport_header(skb) - skb->data;
459 
460 	/* convert Ethernet header to proper 802.11 header (based on
461 	 * operation mode) */
462 	ethertype = (skb->data[12] << 8) | skb->data[13];
463 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
464 
465 	switch (iftype) {
466 	case NL80211_IFTYPE_AP:
467 	case NL80211_IFTYPE_AP_VLAN:
468 	case NL80211_IFTYPE_P2P_GO:
469 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
470 		/* DA BSSID SA */
471 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
472 		memcpy(hdr.addr2, addr, ETH_ALEN);
473 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
474 		hdrlen = 24;
475 		break;
476 	case NL80211_IFTYPE_STATION:
477 	case NL80211_IFTYPE_P2P_CLIENT:
478 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
479 		/* BSSID SA DA */
480 		memcpy(hdr.addr1, bssid, ETH_ALEN);
481 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
482 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
483 		hdrlen = 24;
484 		break;
485 	case NL80211_IFTYPE_ADHOC:
486 		/* DA SA BSSID */
487 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
488 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
489 		memcpy(hdr.addr3, bssid, ETH_ALEN);
490 		hdrlen = 24;
491 		break;
492 	default:
493 		return -EOPNOTSUPP;
494 	}
495 
496 	if (qos) {
497 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
498 		hdrlen += 2;
499 	}
500 
501 	hdr.frame_control = fc;
502 	hdr.duration_id = 0;
503 	hdr.seq_ctrl = 0;
504 
505 	skip_header_bytes = ETH_HLEN;
506 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
507 		encaps_data = bridge_tunnel_header;
508 		encaps_len = sizeof(bridge_tunnel_header);
509 		skip_header_bytes -= 2;
510 	} else if (ethertype > 0x600) {
511 		encaps_data = rfc1042_header;
512 		encaps_len = sizeof(rfc1042_header);
513 		skip_header_bytes -= 2;
514 	} else {
515 		encaps_data = NULL;
516 		encaps_len = 0;
517 	}
518 
519 	skb_pull(skb, skip_header_bytes);
520 	nh_pos -= skip_header_bytes;
521 	h_pos -= skip_header_bytes;
522 
523 	head_need = hdrlen + encaps_len - skb_headroom(skb);
524 
525 	if (head_need > 0 || skb_cloned(skb)) {
526 		head_need = max(head_need, 0);
527 		if (head_need)
528 			skb_orphan(skb);
529 
530 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC))
531 			return -ENOMEM;
532 
533 		skb->truesize += head_need;
534 	}
535 
536 	if (encaps_data) {
537 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
538 		nh_pos += encaps_len;
539 		h_pos += encaps_len;
540 	}
541 
542 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
543 
544 	nh_pos += hdrlen;
545 	h_pos += hdrlen;
546 
547 	/* Update skb pointers to various headers since this modified frame
548 	 * is going to go through Linux networking code that may potentially
549 	 * need things like pointer to IP header. */
550 	skb_set_mac_header(skb, 0);
551 	skb_set_network_header(skb, nh_pos);
552 	skb_set_transport_header(skb, h_pos);
553 
554 	return 0;
555 }
556 EXPORT_SYMBOL(ieee80211_data_from_8023);
557 
558 
559 void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
560 			      const u8 *addr, enum nl80211_iftype iftype,
561 			      const unsigned int extra_headroom,
562 			      bool has_80211_header)
563 {
564 	struct sk_buff *frame = NULL;
565 	u16 ethertype;
566 	u8 *payload;
567 	const struct ethhdr *eth;
568 	int remaining, err;
569 	u8 dst[ETH_ALEN], src[ETH_ALEN];
570 
571 	if (has_80211_header) {
572 		err = ieee80211_data_to_8023(skb, addr, iftype);
573 		if (err)
574 			goto out;
575 
576 		/* skip the wrapping header */
577 		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
578 		if (!eth)
579 			goto out;
580 	} else {
581 		eth = (struct ethhdr *) skb->data;
582 	}
583 
584 	while (skb != frame) {
585 		u8 padding;
586 		__be16 len = eth->h_proto;
587 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
588 
589 		remaining = skb->len;
590 		memcpy(dst, eth->h_dest, ETH_ALEN);
591 		memcpy(src, eth->h_source, ETH_ALEN);
592 
593 		padding = (4 - subframe_len) & 0x3;
594 		/* the last MSDU has no padding */
595 		if (subframe_len > remaining)
596 			goto purge;
597 
598 		skb_pull(skb, sizeof(struct ethhdr));
599 		/* reuse skb for the last subframe */
600 		if (remaining <= subframe_len + padding)
601 			frame = skb;
602 		else {
603 			unsigned int hlen = ALIGN(extra_headroom, 4);
604 			/*
605 			 * Allocate and reserve two bytes more for payload
606 			 * alignment since sizeof(struct ethhdr) is 14.
607 			 */
608 			frame = dev_alloc_skb(hlen + subframe_len + 2);
609 			if (!frame)
610 				goto purge;
611 
612 			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
613 			memcpy(skb_put(frame, ntohs(len)), skb->data,
614 				ntohs(len));
615 
616 			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
617 							padding);
618 			if (!eth) {
619 				dev_kfree_skb(frame);
620 				goto purge;
621 			}
622 		}
623 
624 		skb_reset_network_header(frame);
625 		frame->dev = skb->dev;
626 		frame->priority = skb->priority;
627 
628 		payload = frame->data;
629 		ethertype = (payload[6] << 8) | payload[7];
630 
631 		if (likely((ether_addr_equal(payload, rfc1042_header) &&
632 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
633 			   ether_addr_equal(payload, bridge_tunnel_header))) {
634 			/* remove RFC1042 or Bridge-Tunnel
635 			 * encapsulation and replace EtherType */
636 			skb_pull(frame, 6);
637 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
638 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
639 		} else {
640 			memcpy(skb_push(frame, sizeof(__be16)), &len,
641 				sizeof(__be16));
642 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
643 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
644 		}
645 		__skb_queue_tail(list, frame);
646 	}
647 
648 	return;
649 
650  purge:
651 	__skb_queue_purge(list);
652  out:
653 	dev_kfree_skb(skb);
654 }
655 EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
656 
657 /* Given a data frame determine the 802.1p/1d tag to use. */
658 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
659 {
660 	unsigned int dscp;
661 
662 	/* skb->priority values from 256->263 are magic values to
663 	 * directly indicate a specific 802.1d priority.  This is used
664 	 * to allow 802.1d priority to be passed directly in from VLAN
665 	 * tags, etc.
666 	 */
667 	if (skb->priority >= 256 && skb->priority <= 263)
668 		return skb->priority - 256;
669 
670 	switch (skb->protocol) {
671 	case htons(ETH_P_IP):
672 		dscp = ipv4_get_dsfield(ip_hdr(skb)) & 0xfc;
673 		break;
674 	case htons(ETH_P_IPV6):
675 		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & 0xfc;
676 		break;
677 	default:
678 		return 0;
679 	}
680 
681 	return dscp >> 5;
682 }
683 EXPORT_SYMBOL(cfg80211_classify8021d);
684 
685 const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
686 {
687 	if (bss->information_elements == NULL)
688 		return NULL;
689 	return cfg80211_find_ie(ie, bss->information_elements,
690 				 bss->len_information_elements);
691 }
692 EXPORT_SYMBOL(ieee80211_bss_get_ie);
693 
694 void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
695 {
696 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
697 	struct net_device *dev = wdev->netdev;
698 	int i;
699 
700 	if (!wdev->connect_keys)
701 		return;
702 
703 	for (i = 0; i < 6; i++) {
704 		if (!wdev->connect_keys->params[i].cipher)
705 			continue;
706 		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,
707 					&wdev->connect_keys->params[i])) {
708 			netdev_err(dev, "failed to set key %d\n", i);
709 			continue;
710 		}
711 		if (wdev->connect_keys->def == i)
712 			if (rdev->ops->set_default_key(wdev->wiphy, dev,
713 						       i, true, true)) {
714 				netdev_err(dev, "failed to set defkey %d\n", i);
715 				continue;
716 			}
717 		if (wdev->connect_keys->defmgmt == i)
718 			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
719 				netdev_err(dev, "failed to set mgtdef %d\n", i);
720 	}
721 
722 	kfree(wdev->connect_keys);
723 	wdev->connect_keys = NULL;
724 }
725 
726 void cfg80211_process_wdev_events(struct wireless_dev *wdev)
727 {
728 	struct cfg80211_event *ev;
729 	unsigned long flags;
730 	const u8 *bssid = NULL;
731 
732 	spin_lock_irqsave(&wdev->event_lock, flags);
733 	while (!list_empty(&wdev->event_list)) {
734 		ev = list_first_entry(&wdev->event_list,
735 				      struct cfg80211_event, list);
736 		list_del(&ev->list);
737 		spin_unlock_irqrestore(&wdev->event_lock, flags);
738 
739 		wdev_lock(wdev);
740 		switch (ev->type) {
741 		case EVENT_CONNECT_RESULT:
742 			if (!is_zero_ether_addr(ev->cr.bssid))
743 				bssid = ev->cr.bssid;
744 			__cfg80211_connect_result(
745 				wdev->netdev, bssid,
746 				ev->cr.req_ie, ev->cr.req_ie_len,
747 				ev->cr.resp_ie, ev->cr.resp_ie_len,
748 				ev->cr.status,
749 				ev->cr.status == WLAN_STATUS_SUCCESS,
750 				NULL);
751 			break;
752 		case EVENT_ROAMED:
753 			__cfg80211_roamed(wdev, ev->rm.bss, ev->rm.req_ie,
754 					  ev->rm.req_ie_len, ev->rm.resp_ie,
755 					  ev->rm.resp_ie_len);
756 			break;
757 		case EVENT_DISCONNECTED:
758 			__cfg80211_disconnected(wdev->netdev,
759 						ev->dc.ie, ev->dc.ie_len,
760 						ev->dc.reason, true);
761 			break;
762 		case EVENT_IBSS_JOINED:
763 			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
764 			break;
765 		}
766 		wdev_unlock(wdev);
767 
768 		kfree(ev);
769 
770 		spin_lock_irqsave(&wdev->event_lock, flags);
771 	}
772 	spin_unlock_irqrestore(&wdev->event_lock, flags);
773 }
774 
775 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
776 {
777 	struct wireless_dev *wdev;
778 
779 	ASSERT_RTNL();
780 	ASSERT_RDEV_LOCK(rdev);
781 
782 	mutex_lock(&rdev->devlist_mtx);
783 
784 	list_for_each_entry(wdev, &rdev->wdev_list, list)
785 		cfg80211_process_wdev_events(wdev);
786 
787 	mutex_unlock(&rdev->devlist_mtx);
788 }
789 
790 int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
791 			  struct net_device *dev, enum nl80211_iftype ntype,
792 			  u32 *flags, struct vif_params *params)
793 {
794 	int err;
795 	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
796 
797 	ASSERT_RDEV_LOCK(rdev);
798 
799 	/* don't support changing VLANs, you just re-create them */
800 	if (otype == NL80211_IFTYPE_AP_VLAN)
801 		return -EOPNOTSUPP;
802 
803 	/* cannot change into P2P device type */
804 	if (ntype == NL80211_IFTYPE_P2P_DEVICE)
805 		return -EOPNOTSUPP;
806 
807 	if (!rdev->ops->change_virtual_intf ||
808 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
809 		return -EOPNOTSUPP;
810 
811 	/* if it's part of a bridge, reject changing type to station/ibss */
812 	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&
813 	    (ntype == NL80211_IFTYPE_ADHOC ||
814 	     ntype == NL80211_IFTYPE_STATION ||
815 	     ntype == NL80211_IFTYPE_P2P_CLIENT))
816 		return -EBUSY;
817 
818 	if (ntype != otype && netif_running(dev)) {
819 		mutex_lock(&rdev->devlist_mtx);
820 		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
821 						    ntype);
822 		mutex_unlock(&rdev->devlist_mtx);
823 		if (err)
824 			return err;
825 
826 		dev->ieee80211_ptr->use_4addr = false;
827 		dev->ieee80211_ptr->mesh_id_up_len = 0;
828 
829 		switch (otype) {
830 		case NL80211_IFTYPE_AP:
831 			cfg80211_stop_ap(rdev, dev);
832 			break;
833 		case NL80211_IFTYPE_ADHOC:
834 			cfg80211_leave_ibss(rdev, dev, false);
835 			break;
836 		case NL80211_IFTYPE_STATION:
837 		case NL80211_IFTYPE_P2P_CLIENT:
838 			cfg80211_disconnect(rdev, dev,
839 					    WLAN_REASON_DEAUTH_LEAVING, true);
840 			break;
841 		case NL80211_IFTYPE_MESH_POINT:
842 			/* mesh should be handled? */
843 			break;
844 		default:
845 			break;
846 		}
847 
848 		cfg80211_process_rdev_events(rdev);
849 	}
850 
851 	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
852 					     ntype, flags, params);
853 
854 	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
855 
856 	if (!err && params && params->use_4addr != -1)
857 		dev->ieee80211_ptr->use_4addr = params->use_4addr;
858 
859 	if (!err) {
860 		dev->priv_flags &= ~IFF_DONT_BRIDGE;
861 		switch (ntype) {
862 		case NL80211_IFTYPE_STATION:
863 			if (dev->ieee80211_ptr->use_4addr)
864 				break;
865 			/* fall through */
866 		case NL80211_IFTYPE_P2P_CLIENT:
867 		case NL80211_IFTYPE_ADHOC:
868 			dev->priv_flags |= IFF_DONT_BRIDGE;
869 			break;
870 		case NL80211_IFTYPE_P2P_GO:
871 		case NL80211_IFTYPE_AP:
872 		case NL80211_IFTYPE_AP_VLAN:
873 		case NL80211_IFTYPE_WDS:
874 		case NL80211_IFTYPE_MESH_POINT:
875 			/* bridging OK */
876 			break;
877 		case NL80211_IFTYPE_MONITOR:
878 			/* monitor can't bridge anyway */
879 			break;
880 		case NL80211_IFTYPE_UNSPECIFIED:
881 		case NUM_NL80211_IFTYPES:
882 			/* not happening */
883 			break;
884 		case NL80211_IFTYPE_P2P_DEVICE:
885 			WARN_ON(1);
886 			break;
887 		}
888 	}
889 
890 	if (!err && ntype != otype && netif_running(dev)) {
891 		cfg80211_update_iface_num(rdev, ntype, 1);
892 		cfg80211_update_iface_num(rdev, otype, -1);
893 	}
894 
895 	return err;
896 }
897 
898 static u32 cfg80211_calculate_bitrate_60g(struct rate_info *rate)
899 {
900 	static const u32 __mcs2bitrate[] = {
901 		/* control PHY */
902 		[0] =   275,
903 		/* SC PHY */
904 		[1] =  3850,
905 		[2] =  7700,
906 		[3] =  9625,
907 		[4] = 11550,
908 		[5] = 12512, /* 1251.25 mbps */
909 		[6] = 15400,
910 		[7] = 19250,
911 		[8] = 23100,
912 		[9] = 25025,
913 		[10] = 30800,
914 		[11] = 38500,
915 		[12] = 46200,
916 		/* OFDM PHY */
917 		[13] =  6930,
918 		[14] =  8662, /* 866.25 mbps */
919 		[15] = 13860,
920 		[16] = 17325,
921 		[17] = 20790,
922 		[18] = 27720,
923 		[19] = 34650,
924 		[20] = 41580,
925 		[21] = 45045,
926 		[22] = 51975,
927 		[23] = 62370,
928 		[24] = 67568, /* 6756.75 mbps */
929 		/* LP-SC PHY */
930 		[25] =  6260,
931 		[26] =  8340,
932 		[27] = 11120,
933 		[28] = 12510,
934 		[29] = 16680,
935 		[30] = 22240,
936 		[31] = 25030,
937 	};
938 
939 	if (WARN_ON_ONCE(rate->mcs >= ARRAY_SIZE(__mcs2bitrate)))
940 		return 0;
941 
942 	return __mcs2bitrate[rate->mcs];
943 }
944 
945 u32 cfg80211_calculate_bitrate(struct rate_info *rate)
946 {
947 	int modulation, streams, bitrate;
948 
949 	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
950 		return rate->legacy;
951 	if (rate->flags & RATE_INFO_FLAGS_60G)
952 		return cfg80211_calculate_bitrate_60g(rate);
953 
954 	/* the formula below does only work for MCS values smaller than 32 */
955 	if (WARN_ON_ONCE(rate->mcs >= 32))
956 		return 0;
957 
958 	modulation = rate->mcs & 7;
959 	streams = (rate->mcs >> 3) + 1;
960 
961 	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
962 			13500000 : 6500000;
963 
964 	if (modulation < 4)
965 		bitrate *= (modulation + 1);
966 	else if (modulation == 4)
967 		bitrate *= (modulation + 2);
968 	else
969 		bitrate *= (modulation + 3);
970 
971 	bitrate *= streams;
972 
973 	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
974 		bitrate = (bitrate / 9) * 10;
975 
976 	/* do NOT round down here */
977 	return (bitrate + 50000) / 100000;
978 }
979 EXPORT_SYMBOL(cfg80211_calculate_bitrate);
980 
981 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
982 				 u32 beacon_int)
983 {
984 	struct wireless_dev *wdev;
985 	int res = 0;
986 
987 	if (!beacon_int)
988 		return -EINVAL;
989 
990 	mutex_lock(&rdev->devlist_mtx);
991 
992 	list_for_each_entry(wdev, &rdev->wdev_list, list) {
993 		if (!wdev->beacon_interval)
994 			continue;
995 		if (wdev->beacon_interval != beacon_int) {
996 			res = -EINVAL;
997 			break;
998 		}
999 	}
1000 
1001 	mutex_unlock(&rdev->devlist_mtx);
1002 
1003 	return res;
1004 }
1005 
1006 int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
1007 				 struct wireless_dev *wdev,
1008 				 enum nl80211_iftype iftype,
1009 				 struct ieee80211_channel *chan,
1010 				 enum cfg80211_chan_mode chanmode)
1011 {
1012 	struct wireless_dev *wdev_iter;
1013 	u32 used_iftypes = BIT(iftype);
1014 	int num[NUM_NL80211_IFTYPES];
1015 	struct ieee80211_channel
1016 			*used_channels[CFG80211_MAX_NUM_DIFFERENT_CHANNELS];
1017 	struct ieee80211_channel *ch;
1018 	enum cfg80211_chan_mode chmode;
1019 	int num_different_channels = 0;
1020 	int total = 1;
1021 	int i, j;
1022 
1023 	ASSERT_RTNL();
1024 	lockdep_assert_held(&rdev->devlist_mtx);
1025 
1026 	/* Always allow software iftypes */
1027 	if (rdev->wiphy.software_iftypes & BIT(iftype))
1028 		return 0;
1029 
1030 	memset(num, 0, sizeof(num));
1031 	memset(used_channels, 0, sizeof(used_channels));
1032 
1033 	num[iftype] = 1;
1034 
1035 	switch (chanmode) {
1036 	case CHAN_MODE_UNDEFINED:
1037 		break;
1038 	case CHAN_MODE_SHARED:
1039 		WARN_ON(!chan);
1040 		used_channels[0] = chan;
1041 		num_different_channels++;
1042 		break;
1043 	case CHAN_MODE_EXCLUSIVE:
1044 		num_different_channels++;
1045 		break;
1046 	}
1047 
1048 	list_for_each_entry(wdev_iter, &rdev->wdev_list, list) {
1049 		if (wdev_iter == wdev)
1050 			continue;
1051 		if (wdev_iter->netdev) {
1052 			if (!netif_running(wdev_iter->netdev))
1053 				continue;
1054 		} else if (wdev_iter->iftype == NL80211_IFTYPE_P2P_DEVICE) {
1055 			if (!wdev_iter->p2p_started)
1056 				continue;
1057 		} else {
1058 			WARN_ON(1);
1059 		}
1060 
1061 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
1062 			continue;
1063 
1064 		/*
1065 		 * We may be holding the "wdev" mutex, but now need to lock
1066 		 * wdev_iter. This is OK because once we get here wdev_iter
1067 		 * is not wdev (tested above), but we need to use the nested
1068 		 * locking for lockdep.
1069 		 */
1070 		mutex_lock_nested(&wdev_iter->mtx, 1);
1071 		__acquire(wdev_iter->mtx);
1072 		cfg80211_get_chan_state(wdev_iter, &ch, &chmode);
1073 		wdev_unlock(wdev_iter);
1074 
1075 		switch (chmode) {
1076 		case CHAN_MODE_UNDEFINED:
1077 			break;
1078 		case CHAN_MODE_SHARED:
1079 			for (i = 0; i < CFG80211_MAX_NUM_DIFFERENT_CHANNELS; i++)
1080 				if (!used_channels[i] || used_channels[i] == ch)
1081 					break;
1082 
1083 			if (i == CFG80211_MAX_NUM_DIFFERENT_CHANNELS)
1084 				return -EBUSY;
1085 
1086 			if (used_channels[i] == NULL) {
1087 				used_channels[i] = ch;
1088 				num_different_channels++;
1089 			}
1090 			break;
1091 		case CHAN_MODE_EXCLUSIVE:
1092 			num_different_channels++;
1093 			break;
1094 		}
1095 
1096 		num[wdev_iter->iftype]++;
1097 		total++;
1098 		used_iftypes |= BIT(wdev_iter->iftype);
1099 	}
1100 
1101 	if (total == 1)
1102 		return 0;
1103 
1104 	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
1105 		const struct ieee80211_iface_combination *c;
1106 		struct ieee80211_iface_limit *limits;
1107 		u32 all_iftypes = 0;
1108 
1109 		c = &rdev->wiphy.iface_combinations[i];
1110 
1111 		if (total > c->max_interfaces)
1112 			continue;
1113 		if (num_different_channels > c->num_different_channels)
1114 			continue;
1115 
1116 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
1117 				 GFP_KERNEL);
1118 		if (!limits)
1119 			return -ENOMEM;
1120 
1121 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
1122 			if (rdev->wiphy.software_iftypes & BIT(iftype))
1123 				continue;
1124 			for (j = 0; j < c->n_limits; j++) {
1125 				all_iftypes |= limits[j].types;
1126 				if (!(limits[j].types & BIT(iftype)))
1127 					continue;
1128 				if (limits[j].max < num[iftype])
1129 					goto cont;
1130 				limits[j].max -= num[iftype];
1131 			}
1132 		}
1133 
1134 		/*
1135 		 * Finally check that all iftypes that we're currently
1136 		 * using are actually part of this combination. If they
1137 		 * aren't then we can't use this combination and have
1138 		 * to continue to the next.
1139 		 */
1140 		if ((all_iftypes & used_iftypes) != used_iftypes)
1141 			goto cont;
1142 
1143 		/*
1144 		 * This combination covered all interface types and
1145 		 * supported the requested numbers, so we're good.
1146 		 */
1147 		kfree(limits);
1148 		return 0;
1149  cont:
1150 		kfree(limits);
1151 	}
1152 
1153 	return -EBUSY;
1154 }
1155 
1156 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
1157 			   const u8 *rates, unsigned int n_rates,
1158 			   u32 *mask)
1159 {
1160 	int i, j;
1161 
1162 	if (!sband)
1163 		return -EINVAL;
1164 
1165 	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
1166 		return -EINVAL;
1167 
1168 	*mask = 0;
1169 
1170 	for (i = 0; i < n_rates; i++) {
1171 		int rate = (rates[i] & 0x7f) * 5;
1172 		bool found = false;
1173 
1174 		for (j = 0; j < sband->n_bitrates; j++) {
1175 			if (sband->bitrates[j].bitrate == rate) {
1176 				found = true;
1177 				*mask |= BIT(j);
1178 				break;
1179 			}
1180 		}
1181 		if (!found)
1182 			return -EINVAL;
1183 	}
1184 
1185 	/*
1186 	 * mask must have at least one bit set here since we
1187 	 * didn't accept a 0-length rates array nor allowed
1188 	 * entries in the array that didn't exist
1189 	 */
1190 
1191 	return 0;
1192 }
1193 
1194 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
1195 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
1196 const unsigned char rfc1042_header[] __aligned(2) =
1197 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
1198 EXPORT_SYMBOL(rfc1042_header);
1199 
1200 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
1201 const unsigned char bridge_tunnel_header[] __aligned(2) =
1202 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
1203 EXPORT_SYMBOL(bridge_tunnel_header);
1204