xref: /linux/net/wireless/util.c (revision 9e8ba5f3ec35cba4fd8a8bebda548c4db2651e40)
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 "core.h"
13 
14 struct ieee80211_rate *
15 ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
16 			    u32 basic_rates, int bitrate)
17 {
18 	struct ieee80211_rate *result = &sband->bitrates[0];
19 	int i;
20 
21 	for (i = 0; i < sband->n_bitrates; i++) {
22 		if (!(basic_rates & BIT(i)))
23 			continue;
24 		if (sband->bitrates[i].bitrate > bitrate)
25 			continue;
26 		result = &sband->bitrates[i];
27 	}
28 
29 	return result;
30 }
31 EXPORT_SYMBOL(ieee80211_get_response_rate);
32 
33 int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)
34 {
35 	/* see 802.11 17.3.8.3.2 and Annex J
36 	 * there are overlapping channel numbers in 5GHz and 2GHz bands */
37 	if (band == IEEE80211_BAND_5GHZ) {
38 		if (chan >= 182 && chan <= 196)
39 			return 4000 + chan * 5;
40 		else
41 			return 5000 + chan * 5;
42 	} else { /* IEEE80211_BAND_2GHZ */
43 		if (chan == 14)
44 			return 2484;
45 		else if (chan < 14)
46 			return 2407 + chan * 5;
47 		else
48 			return 0; /* not supported */
49 	}
50 }
51 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
52 
53 int ieee80211_frequency_to_channel(int freq)
54 {
55 	/* see 802.11 17.3.8.3.2 and Annex J */
56 	if (freq == 2484)
57 		return 14;
58 	else if (freq < 2484)
59 		return (freq - 2407) / 5;
60 	else if (freq >= 4910 && freq <= 4980)
61 		return (freq - 4000) / 5;
62 	else
63 		return (freq - 5000) / 5;
64 }
65 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
66 
67 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
68 						  int freq)
69 {
70 	enum ieee80211_band band;
71 	struct ieee80211_supported_band *sband;
72 	int i;
73 
74 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
75 		sband = wiphy->bands[band];
76 
77 		if (!sband)
78 			continue;
79 
80 		for (i = 0; i < sband->n_channels; i++) {
81 			if (sband->channels[i].center_freq == freq)
82 				return &sband->channels[i];
83 		}
84 	}
85 
86 	return NULL;
87 }
88 EXPORT_SYMBOL(__ieee80211_get_channel);
89 
90 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
91 				     enum ieee80211_band band)
92 {
93 	int i, want;
94 
95 	switch (band) {
96 	case IEEE80211_BAND_5GHZ:
97 		want = 3;
98 		for (i = 0; i < sband->n_bitrates; i++) {
99 			if (sband->bitrates[i].bitrate == 60 ||
100 			    sband->bitrates[i].bitrate == 120 ||
101 			    sband->bitrates[i].bitrate == 240) {
102 				sband->bitrates[i].flags |=
103 					IEEE80211_RATE_MANDATORY_A;
104 				want--;
105 			}
106 		}
107 		WARN_ON(want);
108 		break;
109 	case IEEE80211_BAND_2GHZ:
110 		want = 7;
111 		for (i = 0; i < sband->n_bitrates; i++) {
112 			if (sband->bitrates[i].bitrate == 10) {
113 				sband->bitrates[i].flags |=
114 					IEEE80211_RATE_MANDATORY_B |
115 					IEEE80211_RATE_MANDATORY_G;
116 				want--;
117 			}
118 
119 			if (sband->bitrates[i].bitrate == 20 ||
120 			    sband->bitrates[i].bitrate == 55 ||
121 			    sband->bitrates[i].bitrate == 110 ||
122 			    sband->bitrates[i].bitrate == 60 ||
123 			    sband->bitrates[i].bitrate == 120 ||
124 			    sband->bitrates[i].bitrate == 240) {
125 				sband->bitrates[i].flags |=
126 					IEEE80211_RATE_MANDATORY_G;
127 				want--;
128 			}
129 
130 			if (sband->bitrates[i].bitrate != 10 &&
131 			    sband->bitrates[i].bitrate != 20 &&
132 			    sband->bitrates[i].bitrate != 55 &&
133 			    sband->bitrates[i].bitrate != 110)
134 				sband->bitrates[i].flags |=
135 					IEEE80211_RATE_ERP_G;
136 		}
137 		WARN_ON(want != 0 && want != 3 && want != 6);
138 		break;
139 	case IEEE80211_NUM_BANDS:
140 		WARN_ON(1);
141 		break;
142 	}
143 }
144 
145 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
146 {
147 	enum ieee80211_band band;
148 
149 	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
150 		if (wiphy->bands[band])
151 			set_mandatory_flags_band(wiphy->bands[band], band);
152 }
153 
154 bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
155 {
156 	int i;
157 	for (i = 0; i < wiphy->n_cipher_suites; i++)
158 		if (cipher == wiphy->cipher_suites[i])
159 			return true;
160 	return false;
161 }
162 
163 int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
164 				   struct key_params *params, int key_idx,
165 				   bool pairwise, const u8 *mac_addr)
166 {
167 	if (key_idx > 5)
168 		return -EINVAL;
169 
170 	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
171 		return -EINVAL;
172 
173 	if (pairwise && !mac_addr)
174 		return -EINVAL;
175 
176 	/*
177 	 * Disallow pairwise keys with non-zero index unless it's WEP
178 	 * or a vendor specific cipher (because current deployments use
179 	 * pairwise WEP keys with non-zero indices and for vendor specific
180 	 * ciphers this should be validated in the driver or hardware level
181 	 * - but 802.11i clearly specifies to use zero)
182 	 */
183 	if (pairwise && key_idx &&
184 	    ((params->cipher == WLAN_CIPHER_SUITE_TKIP) ||
185 	     (params->cipher == WLAN_CIPHER_SUITE_CCMP) ||
186 	     (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC)))
187 		return -EINVAL;
188 
189 	switch (params->cipher) {
190 	case WLAN_CIPHER_SUITE_WEP40:
191 		if (params->key_len != WLAN_KEY_LEN_WEP40)
192 			return -EINVAL;
193 		break;
194 	case WLAN_CIPHER_SUITE_TKIP:
195 		if (params->key_len != WLAN_KEY_LEN_TKIP)
196 			return -EINVAL;
197 		break;
198 	case WLAN_CIPHER_SUITE_CCMP:
199 		if (params->key_len != WLAN_KEY_LEN_CCMP)
200 			return -EINVAL;
201 		break;
202 	case WLAN_CIPHER_SUITE_WEP104:
203 		if (params->key_len != WLAN_KEY_LEN_WEP104)
204 			return -EINVAL;
205 		break;
206 	case WLAN_CIPHER_SUITE_AES_CMAC:
207 		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
208 			return -EINVAL;
209 		break;
210 	default:
211 		/*
212 		 * We don't know anything about this algorithm,
213 		 * allow using it -- but the driver must check
214 		 * all parameters! We still check below whether
215 		 * or not the driver supports this algorithm,
216 		 * of course.
217 		 */
218 		break;
219 	}
220 
221 	if (params->seq) {
222 		switch (params->cipher) {
223 		case WLAN_CIPHER_SUITE_WEP40:
224 		case WLAN_CIPHER_SUITE_WEP104:
225 			/* These ciphers do not use key sequence */
226 			return -EINVAL;
227 		case WLAN_CIPHER_SUITE_TKIP:
228 		case WLAN_CIPHER_SUITE_CCMP:
229 		case WLAN_CIPHER_SUITE_AES_CMAC:
230 			if (params->seq_len != 6)
231 				return -EINVAL;
232 			break;
233 		}
234 	}
235 
236 	if (!cfg80211_supported_cipher_suite(&rdev->wiphy, params->cipher))
237 		return -EINVAL;
238 
239 	return 0;
240 }
241 
242 unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
243 {
244 	unsigned int hdrlen = 24;
245 
246 	if (ieee80211_is_data(fc)) {
247 		if (ieee80211_has_a4(fc))
248 			hdrlen = 30;
249 		if (ieee80211_is_data_qos(fc)) {
250 			hdrlen += IEEE80211_QOS_CTL_LEN;
251 			if (ieee80211_has_order(fc))
252 				hdrlen += IEEE80211_HT_CTL_LEN;
253 		}
254 		goto out;
255 	}
256 
257 	if (ieee80211_is_ctl(fc)) {
258 		/*
259 		 * ACK and CTS are 10 bytes, all others 16. To see how
260 		 * to get this condition consider
261 		 *   subtype mask:   0b0000000011110000 (0x00F0)
262 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
263 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
264 		 *   bits that matter:         ^^^      (0x00E0)
265 		 *   value of those: 0b0000000011000000 (0x00C0)
266 		 */
267 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
268 			hdrlen = 10;
269 		else
270 			hdrlen = 16;
271 	}
272 out:
273 	return hdrlen;
274 }
275 EXPORT_SYMBOL(ieee80211_hdrlen);
276 
277 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
278 {
279 	const struct ieee80211_hdr *hdr =
280 			(const struct ieee80211_hdr *)skb->data;
281 	unsigned int hdrlen;
282 
283 	if (unlikely(skb->len < 10))
284 		return 0;
285 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
286 	if (unlikely(hdrlen > skb->len))
287 		return 0;
288 	return hdrlen;
289 }
290 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
291 
292 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
293 {
294 	int ae = meshhdr->flags & MESH_FLAGS_AE;
295 	/* 7.1.3.5a.2 */
296 	switch (ae) {
297 	case 0:
298 		return 6;
299 	case MESH_FLAGS_AE_A4:
300 		return 12;
301 	case MESH_FLAGS_AE_A5_A6:
302 		return 18;
303 	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
304 		return 24;
305 	default:
306 		return 6;
307 	}
308 }
309 
310 int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
311 			   enum nl80211_iftype iftype)
312 {
313 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
314 	u16 hdrlen, ethertype;
315 	u8 *payload;
316 	u8 dst[ETH_ALEN];
317 	u8 src[ETH_ALEN] __aligned(2);
318 
319 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
320 		return -1;
321 
322 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
323 
324 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
325 	 * header
326 	 * IEEE 802.11 address fields:
327 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
328 	 *   0     0   DA    SA    BSSID n/a
329 	 *   0     1   DA    BSSID SA    n/a
330 	 *   1     0   BSSID SA    DA    n/a
331 	 *   1     1   RA    TA    DA    SA
332 	 */
333 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
334 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
335 
336 	switch (hdr->frame_control &
337 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
338 	case cpu_to_le16(IEEE80211_FCTL_TODS):
339 		if (unlikely(iftype != NL80211_IFTYPE_AP &&
340 			     iftype != NL80211_IFTYPE_AP_VLAN &&
341 			     iftype != NL80211_IFTYPE_P2P_GO))
342 			return -1;
343 		break;
344 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
345 		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
346 			     iftype != NL80211_IFTYPE_MESH_POINT &&
347 			     iftype != NL80211_IFTYPE_AP_VLAN &&
348 			     iftype != NL80211_IFTYPE_STATION))
349 			return -1;
350 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
351 			struct ieee80211s_hdr *meshdr =
352 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
353 			/* make sure meshdr->flags is on the linear part */
354 			if (!pskb_may_pull(skb, hdrlen + 1))
355 				return -1;
356 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
357 				skb_copy_bits(skb, hdrlen +
358 					offsetof(struct ieee80211s_hdr, eaddr1),
359 				       	dst, ETH_ALEN);
360 				skb_copy_bits(skb, hdrlen +
361 					offsetof(struct ieee80211s_hdr, eaddr2),
362 				        src, ETH_ALEN);
363 			}
364 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
365 		}
366 		break;
367 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
368 		if ((iftype != NL80211_IFTYPE_STATION &&
369 		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
370 		     iftype != NL80211_IFTYPE_MESH_POINT) ||
371 		    (is_multicast_ether_addr(dst) &&
372 		     !compare_ether_addr(src, addr)))
373 			return -1;
374 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
375 			struct ieee80211s_hdr *meshdr =
376 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
377 			/* make sure meshdr->flags is on the linear part */
378 			if (!pskb_may_pull(skb, hdrlen + 1))
379 				return -1;
380 			if (meshdr->flags & MESH_FLAGS_AE_A4)
381 				skb_copy_bits(skb, hdrlen +
382 					offsetof(struct ieee80211s_hdr, eaddr1),
383 					src, ETH_ALEN);
384 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
385 		}
386 		break;
387 	case cpu_to_le16(0):
388 		if (iftype != NL80211_IFTYPE_ADHOC &&
389 		    iftype != NL80211_IFTYPE_STATION)
390 				return -1;
391 		break;
392 	}
393 
394 	if (!pskb_may_pull(skb, hdrlen + 8))
395 		return -1;
396 
397 	payload = skb->data + hdrlen;
398 	ethertype = (payload[6] << 8) | payload[7];
399 
400 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
401 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
402 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
403 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
404 		 * replace EtherType */
405 		skb_pull(skb, hdrlen + 6);
406 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
407 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
408 	} else {
409 		struct ethhdr *ehdr;
410 		__be16 len;
411 
412 		skb_pull(skb, hdrlen);
413 		len = htons(skb->len);
414 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
415 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
416 		memcpy(ehdr->h_source, src, ETH_ALEN);
417 		ehdr->h_proto = len;
418 	}
419 	return 0;
420 }
421 EXPORT_SYMBOL(ieee80211_data_to_8023);
422 
423 int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
424 			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
425 {
426 	struct ieee80211_hdr hdr;
427 	u16 hdrlen, ethertype;
428 	__le16 fc;
429 	const u8 *encaps_data;
430 	int encaps_len, skip_header_bytes;
431 	int nh_pos, h_pos;
432 	int head_need;
433 
434 	if (unlikely(skb->len < ETH_HLEN))
435 		return -EINVAL;
436 
437 	nh_pos = skb_network_header(skb) - skb->data;
438 	h_pos = skb_transport_header(skb) - skb->data;
439 
440 	/* convert Ethernet header to proper 802.11 header (based on
441 	 * operation mode) */
442 	ethertype = (skb->data[12] << 8) | skb->data[13];
443 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
444 
445 	switch (iftype) {
446 	case NL80211_IFTYPE_AP:
447 	case NL80211_IFTYPE_AP_VLAN:
448 	case NL80211_IFTYPE_P2P_GO:
449 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
450 		/* DA BSSID SA */
451 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
452 		memcpy(hdr.addr2, addr, ETH_ALEN);
453 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
454 		hdrlen = 24;
455 		break;
456 	case NL80211_IFTYPE_STATION:
457 	case NL80211_IFTYPE_P2P_CLIENT:
458 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
459 		/* BSSID SA DA */
460 		memcpy(hdr.addr1, bssid, ETH_ALEN);
461 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
462 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
463 		hdrlen = 24;
464 		break;
465 	case NL80211_IFTYPE_ADHOC:
466 		/* DA SA BSSID */
467 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
468 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
469 		memcpy(hdr.addr3, bssid, ETH_ALEN);
470 		hdrlen = 24;
471 		break;
472 	default:
473 		return -EOPNOTSUPP;
474 	}
475 
476 	if (qos) {
477 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
478 		hdrlen += 2;
479 	}
480 
481 	hdr.frame_control = fc;
482 	hdr.duration_id = 0;
483 	hdr.seq_ctrl = 0;
484 
485 	skip_header_bytes = ETH_HLEN;
486 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
487 		encaps_data = bridge_tunnel_header;
488 		encaps_len = sizeof(bridge_tunnel_header);
489 		skip_header_bytes -= 2;
490 	} else if (ethertype > 0x600) {
491 		encaps_data = rfc1042_header;
492 		encaps_len = sizeof(rfc1042_header);
493 		skip_header_bytes -= 2;
494 	} else {
495 		encaps_data = NULL;
496 		encaps_len = 0;
497 	}
498 
499 	skb_pull(skb, skip_header_bytes);
500 	nh_pos -= skip_header_bytes;
501 	h_pos -= skip_header_bytes;
502 
503 	head_need = hdrlen + encaps_len - skb_headroom(skb);
504 
505 	if (head_need > 0 || skb_cloned(skb)) {
506 		head_need = max(head_need, 0);
507 		if (head_need)
508 			skb_orphan(skb);
509 
510 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC))
511 			return -ENOMEM;
512 
513 		skb->truesize += head_need;
514 	}
515 
516 	if (encaps_data) {
517 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
518 		nh_pos += encaps_len;
519 		h_pos += encaps_len;
520 	}
521 
522 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
523 
524 	nh_pos += hdrlen;
525 	h_pos += hdrlen;
526 
527 	/* Update skb pointers to various headers since this modified frame
528 	 * is going to go through Linux networking code that may potentially
529 	 * need things like pointer to IP header. */
530 	skb_set_mac_header(skb, 0);
531 	skb_set_network_header(skb, nh_pos);
532 	skb_set_transport_header(skb, h_pos);
533 
534 	return 0;
535 }
536 EXPORT_SYMBOL(ieee80211_data_from_8023);
537 
538 
539 void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
540 			      const u8 *addr, enum nl80211_iftype iftype,
541 			      const unsigned int extra_headroom,
542 			      bool has_80211_header)
543 {
544 	struct sk_buff *frame = NULL;
545 	u16 ethertype;
546 	u8 *payload;
547 	const struct ethhdr *eth;
548 	int remaining, err;
549 	u8 dst[ETH_ALEN], src[ETH_ALEN];
550 
551 	if (has_80211_header) {
552 		err = ieee80211_data_to_8023(skb, addr, iftype);
553 		if (err)
554 			goto out;
555 
556 		/* skip the wrapping header */
557 		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
558 		if (!eth)
559 			goto out;
560 	} else {
561 		eth = (struct ethhdr *) skb->data;
562 	}
563 
564 	while (skb != frame) {
565 		u8 padding;
566 		__be16 len = eth->h_proto;
567 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
568 
569 		remaining = skb->len;
570 		memcpy(dst, eth->h_dest, ETH_ALEN);
571 		memcpy(src, eth->h_source, ETH_ALEN);
572 
573 		padding = (4 - subframe_len) & 0x3;
574 		/* the last MSDU has no padding */
575 		if (subframe_len > remaining)
576 			goto purge;
577 
578 		skb_pull(skb, sizeof(struct ethhdr));
579 		/* reuse skb for the last subframe */
580 		if (remaining <= subframe_len + padding)
581 			frame = skb;
582 		else {
583 			unsigned int hlen = ALIGN(extra_headroom, 4);
584 			/*
585 			 * Allocate and reserve two bytes more for payload
586 			 * alignment since sizeof(struct ethhdr) is 14.
587 			 */
588 			frame = dev_alloc_skb(hlen + subframe_len + 2);
589 			if (!frame)
590 				goto purge;
591 
592 			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
593 			memcpy(skb_put(frame, ntohs(len)), skb->data,
594 				ntohs(len));
595 
596 			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
597 							padding);
598 			if (!eth) {
599 				dev_kfree_skb(frame);
600 				goto purge;
601 			}
602 		}
603 
604 		skb_reset_network_header(frame);
605 		frame->dev = skb->dev;
606 		frame->priority = skb->priority;
607 
608 		payload = frame->data;
609 		ethertype = (payload[6] << 8) | payload[7];
610 
611 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
612 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
613 			   compare_ether_addr(payload,
614 					      bridge_tunnel_header) == 0)) {
615 			/* remove RFC1042 or Bridge-Tunnel
616 			 * encapsulation and replace EtherType */
617 			skb_pull(frame, 6);
618 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
619 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
620 		} else {
621 			memcpy(skb_push(frame, sizeof(__be16)), &len,
622 				sizeof(__be16));
623 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
624 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
625 		}
626 		__skb_queue_tail(list, frame);
627 	}
628 
629 	return;
630 
631  purge:
632 	__skb_queue_purge(list);
633  out:
634 	dev_kfree_skb(skb);
635 }
636 EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
637 
638 /* Given a data frame determine the 802.1p/1d tag to use. */
639 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
640 {
641 	unsigned int dscp;
642 
643 	/* skb->priority values from 256->263 are magic values to
644 	 * directly indicate a specific 802.1d priority.  This is used
645 	 * to allow 802.1d priority to be passed directly in from VLAN
646 	 * tags, etc.
647 	 */
648 	if (skb->priority >= 256 && skb->priority <= 263)
649 		return skb->priority - 256;
650 
651 	switch (skb->protocol) {
652 	case htons(ETH_P_IP):
653 		dscp = ip_hdr(skb)->tos & 0xfc;
654 		break;
655 	default:
656 		return 0;
657 	}
658 
659 	return dscp >> 5;
660 }
661 EXPORT_SYMBOL(cfg80211_classify8021d);
662 
663 const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
664 {
665 	u8 *end, *pos;
666 
667 	pos = bss->information_elements;
668 	if (pos == NULL)
669 		return NULL;
670 	end = pos + bss->len_information_elements;
671 
672 	while (pos + 1 < end) {
673 		if (pos + 2 + pos[1] > end)
674 			break;
675 		if (pos[0] == ie)
676 			return pos;
677 		pos += 2 + pos[1];
678 	}
679 
680 	return NULL;
681 }
682 EXPORT_SYMBOL(ieee80211_bss_get_ie);
683 
684 void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
685 {
686 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
687 	struct net_device *dev = wdev->netdev;
688 	int i;
689 
690 	if (!wdev->connect_keys)
691 		return;
692 
693 	for (i = 0; i < 6; i++) {
694 		if (!wdev->connect_keys->params[i].cipher)
695 			continue;
696 		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,
697 					&wdev->connect_keys->params[i])) {
698 			netdev_err(dev, "failed to set key %d\n", i);
699 			continue;
700 		}
701 		if (wdev->connect_keys->def == i)
702 			if (rdev->ops->set_default_key(wdev->wiphy, dev,
703 						       i, true, true)) {
704 				netdev_err(dev, "failed to set defkey %d\n", i);
705 				continue;
706 			}
707 		if (wdev->connect_keys->defmgmt == i)
708 			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
709 				netdev_err(dev, "failed to set mgtdef %d\n", i);
710 	}
711 
712 	kfree(wdev->connect_keys);
713 	wdev->connect_keys = NULL;
714 }
715 
716 static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
717 {
718 	struct cfg80211_event *ev;
719 	unsigned long flags;
720 	const u8 *bssid = NULL;
721 
722 	spin_lock_irqsave(&wdev->event_lock, flags);
723 	while (!list_empty(&wdev->event_list)) {
724 		ev = list_first_entry(&wdev->event_list,
725 				      struct cfg80211_event, list);
726 		list_del(&ev->list);
727 		spin_unlock_irqrestore(&wdev->event_lock, flags);
728 
729 		wdev_lock(wdev);
730 		switch (ev->type) {
731 		case EVENT_CONNECT_RESULT:
732 			if (!is_zero_ether_addr(ev->cr.bssid))
733 				bssid = ev->cr.bssid;
734 			__cfg80211_connect_result(
735 				wdev->netdev, bssid,
736 				ev->cr.req_ie, ev->cr.req_ie_len,
737 				ev->cr.resp_ie, ev->cr.resp_ie_len,
738 				ev->cr.status,
739 				ev->cr.status == WLAN_STATUS_SUCCESS,
740 				NULL);
741 			break;
742 		case EVENT_ROAMED:
743 			__cfg80211_roamed(wdev, ev->rm.bss, ev->rm.req_ie,
744 					  ev->rm.req_ie_len, ev->rm.resp_ie,
745 					  ev->rm.resp_ie_len);
746 			break;
747 		case EVENT_DISCONNECTED:
748 			__cfg80211_disconnected(wdev->netdev,
749 						ev->dc.ie, ev->dc.ie_len,
750 						ev->dc.reason, true);
751 			break;
752 		case EVENT_IBSS_JOINED:
753 			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
754 			break;
755 		}
756 		wdev_unlock(wdev);
757 
758 		kfree(ev);
759 
760 		spin_lock_irqsave(&wdev->event_lock, flags);
761 	}
762 	spin_unlock_irqrestore(&wdev->event_lock, flags);
763 }
764 
765 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
766 {
767 	struct wireless_dev *wdev;
768 
769 	ASSERT_RTNL();
770 	ASSERT_RDEV_LOCK(rdev);
771 
772 	mutex_lock(&rdev->devlist_mtx);
773 
774 	list_for_each_entry(wdev, &rdev->netdev_list, list)
775 		cfg80211_process_wdev_events(wdev);
776 
777 	mutex_unlock(&rdev->devlist_mtx);
778 }
779 
780 int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
781 			  struct net_device *dev, enum nl80211_iftype ntype,
782 			  u32 *flags, struct vif_params *params)
783 {
784 	int err;
785 	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
786 
787 	ASSERT_RDEV_LOCK(rdev);
788 
789 	/* don't support changing VLANs, you just re-create them */
790 	if (otype == NL80211_IFTYPE_AP_VLAN)
791 		return -EOPNOTSUPP;
792 
793 	if (!rdev->ops->change_virtual_intf ||
794 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
795 		return -EOPNOTSUPP;
796 
797 	/* if it's part of a bridge, reject changing type to station/ibss */
798 	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&
799 	    (ntype == NL80211_IFTYPE_ADHOC ||
800 	     ntype == NL80211_IFTYPE_STATION ||
801 	     ntype == NL80211_IFTYPE_P2P_CLIENT))
802 		return -EBUSY;
803 
804 	if (ntype != otype) {
805 		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
806 						    ntype);
807 		if (err)
808 			return err;
809 
810 		dev->ieee80211_ptr->use_4addr = false;
811 		dev->ieee80211_ptr->mesh_id_up_len = 0;
812 
813 		switch (otype) {
814 		case NL80211_IFTYPE_ADHOC:
815 			cfg80211_leave_ibss(rdev, dev, false);
816 			break;
817 		case NL80211_IFTYPE_STATION:
818 		case NL80211_IFTYPE_P2P_CLIENT:
819 			cfg80211_disconnect(rdev, dev,
820 					    WLAN_REASON_DEAUTH_LEAVING, true);
821 			break;
822 		case NL80211_IFTYPE_MESH_POINT:
823 			/* mesh should be handled? */
824 			break;
825 		default:
826 			break;
827 		}
828 
829 		cfg80211_process_rdev_events(rdev);
830 	}
831 
832 	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
833 					     ntype, flags, params);
834 
835 	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
836 
837 	if (!err && params && params->use_4addr != -1)
838 		dev->ieee80211_ptr->use_4addr = params->use_4addr;
839 
840 	if (!err) {
841 		dev->priv_flags &= ~IFF_DONT_BRIDGE;
842 		switch (ntype) {
843 		case NL80211_IFTYPE_STATION:
844 			if (dev->ieee80211_ptr->use_4addr)
845 				break;
846 			/* fall through */
847 		case NL80211_IFTYPE_P2P_CLIENT:
848 		case NL80211_IFTYPE_ADHOC:
849 			dev->priv_flags |= IFF_DONT_BRIDGE;
850 			break;
851 		case NL80211_IFTYPE_P2P_GO:
852 		case NL80211_IFTYPE_AP:
853 		case NL80211_IFTYPE_AP_VLAN:
854 		case NL80211_IFTYPE_WDS:
855 		case NL80211_IFTYPE_MESH_POINT:
856 			/* bridging OK */
857 			break;
858 		case NL80211_IFTYPE_MONITOR:
859 			/* monitor can't bridge anyway */
860 			break;
861 		case NL80211_IFTYPE_UNSPECIFIED:
862 		case NUM_NL80211_IFTYPES:
863 			/* not happening */
864 			break;
865 		}
866 	}
867 
868 	return err;
869 }
870 
871 u16 cfg80211_calculate_bitrate(struct rate_info *rate)
872 {
873 	int modulation, streams, bitrate;
874 
875 	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
876 		return rate->legacy;
877 
878 	/* the formula below does only work for MCS values smaller than 32 */
879 	if (rate->mcs >= 32)
880 		return 0;
881 
882 	modulation = rate->mcs & 7;
883 	streams = (rate->mcs >> 3) + 1;
884 
885 	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
886 			13500000 : 6500000;
887 
888 	if (modulation < 4)
889 		bitrate *= (modulation + 1);
890 	else if (modulation == 4)
891 		bitrate *= (modulation + 2);
892 	else
893 		bitrate *= (modulation + 3);
894 
895 	bitrate *= streams;
896 
897 	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
898 		bitrate = (bitrate / 9) * 10;
899 
900 	/* do NOT round down here */
901 	return (bitrate + 50000) / 100000;
902 }
903 
904 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
905 				 u32 beacon_int)
906 {
907 	struct wireless_dev *wdev;
908 	int res = 0;
909 
910 	if (!beacon_int)
911 		return -EINVAL;
912 
913 	mutex_lock(&rdev->devlist_mtx);
914 
915 	list_for_each_entry(wdev, &rdev->netdev_list, list) {
916 		if (!wdev->beacon_interval)
917 			continue;
918 		if (wdev->beacon_interval != beacon_int) {
919 			res = -EINVAL;
920 			break;
921 		}
922 	}
923 
924 	mutex_unlock(&rdev->devlist_mtx);
925 
926 	return res;
927 }
928 
929 int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
930 				  struct wireless_dev *wdev,
931 				  enum nl80211_iftype iftype)
932 {
933 	struct wireless_dev *wdev_iter;
934 	int num[NUM_NL80211_IFTYPES];
935 	int total = 1;
936 	int i, j;
937 
938 	ASSERT_RTNL();
939 
940 	/* Always allow software iftypes */
941 	if (rdev->wiphy.software_iftypes & BIT(iftype))
942 		return 0;
943 
944 	/*
945 	 * Drivers will gradually all set this flag, until all
946 	 * have it we only enforce for those that set it.
947 	 */
948 	if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS))
949 		return 0;
950 
951 	memset(num, 0, sizeof(num));
952 
953 	num[iftype] = 1;
954 
955 	mutex_lock(&rdev->devlist_mtx);
956 	list_for_each_entry(wdev_iter, &rdev->netdev_list, list) {
957 		if (wdev_iter == wdev)
958 			continue;
959 		if (!netif_running(wdev_iter->netdev))
960 			continue;
961 
962 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
963 			continue;
964 
965 		num[wdev_iter->iftype]++;
966 		total++;
967 	}
968 	mutex_unlock(&rdev->devlist_mtx);
969 
970 	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
971 		const struct ieee80211_iface_combination *c;
972 		struct ieee80211_iface_limit *limits;
973 
974 		c = &rdev->wiphy.iface_combinations[i];
975 
976 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
977 				 GFP_KERNEL);
978 		if (!limits)
979 			return -ENOMEM;
980 		if (total > c->max_interfaces)
981 			goto cont;
982 
983 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
984 			if (rdev->wiphy.software_iftypes & BIT(iftype))
985 				continue;
986 			for (j = 0; j < c->n_limits; j++) {
987 				if (!(limits[j].types & iftype))
988 					continue;
989 				if (limits[j].max < num[iftype])
990 					goto cont;
991 				limits[j].max -= num[iftype];
992 			}
993 		}
994 		/* yay, it fits */
995 		kfree(limits);
996 		return 0;
997  cont:
998 		kfree(limits);
999 	}
1000 
1001 	return -EBUSY;
1002 }
1003 
1004 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
1005 			   const u8 *rates, unsigned int n_rates,
1006 			   u32 *mask)
1007 {
1008 	int i, j;
1009 
1010 	if (!sband)
1011 		return -EINVAL;
1012 
1013 	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
1014 		return -EINVAL;
1015 
1016 	*mask = 0;
1017 
1018 	for (i = 0; i < n_rates; i++) {
1019 		int rate = (rates[i] & 0x7f) * 5;
1020 		bool found = false;
1021 
1022 		for (j = 0; j < sband->n_bitrates; j++) {
1023 			if (sband->bitrates[j].bitrate == rate) {
1024 				found = true;
1025 				*mask |= BIT(j);
1026 				break;
1027 			}
1028 		}
1029 		if (!found)
1030 			return -EINVAL;
1031 	}
1032 
1033 	/*
1034 	 * mask must have at least one bit set here since we
1035 	 * didn't accept a 0-length rates array nor allowed
1036 	 * entries in the array that didn't exist
1037 	 */
1038 
1039 	return 0;
1040 }
1041 
1042 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
1043 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
1044 const unsigned char rfc1042_header[] __aligned(2) =
1045 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
1046 EXPORT_SYMBOL(rfc1042_header);
1047 
1048 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
1049 const unsigned char bridge_tunnel_header[] __aligned(2) =
1050 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
1051 EXPORT_SYMBOL(bridge_tunnel_header);
1052