xref: /openbmc/linux/net/wireless/util.c (revision 9cdb81c7)
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 (band == IEEE80211_BAND_5GHZ) {
39 		if (chan >= 182 && chan <= 196)
40 			return 4000 + chan * 5;
41 		else
42 			return 5000 + chan * 5;
43 	} else { /* IEEE80211_BAND_2GHZ */
44 		if (chan == 14)
45 			return 2484;
46 		else if (chan < 14)
47 			return 2407 + chan * 5;
48 		else
49 			return 0; /* not supported */
50 	}
51 }
52 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
53 
54 int ieee80211_frequency_to_channel(int freq)
55 {
56 	/* see 802.11 17.3.8.3.2 and Annex J */
57 	if (freq == 2484)
58 		return 14;
59 	else if (freq < 2484)
60 		return (freq - 2407) / 5;
61 	else if (freq >= 4910 && freq <= 4980)
62 		return (freq - 4000) / 5;
63 	else
64 		return (freq - 5000) / 5;
65 }
66 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
67 
68 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
69 						  int freq)
70 {
71 	enum ieee80211_band band;
72 	struct ieee80211_supported_band *sband;
73 	int i;
74 
75 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
76 		sband = wiphy->bands[band];
77 
78 		if (!sband)
79 			continue;
80 
81 		for (i = 0; i < sband->n_channels; i++) {
82 			if (sband->channels[i].center_freq == freq)
83 				return &sband->channels[i];
84 		}
85 	}
86 
87 	return NULL;
88 }
89 EXPORT_SYMBOL(__ieee80211_get_channel);
90 
91 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
92 				     enum ieee80211_band band)
93 {
94 	int i, want;
95 
96 	switch (band) {
97 	case IEEE80211_BAND_5GHZ:
98 		want = 3;
99 		for (i = 0; i < sband->n_bitrates; i++) {
100 			if (sband->bitrates[i].bitrate == 60 ||
101 			    sband->bitrates[i].bitrate == 120 ||
102 			    sband->bitrates[i].bitrate == 240) {
103 				sband->bitrates[i].flags |=
104 					IEEE80211_RATE_MANDATORY_A;
105 				want--;
106 			}
107 		}
108 		WARN_ON(want);
109 		break;
110 	case IEEE80211_BAND_2GHZ:
111 		want = 7;
112 		for (i = 0; i < sband->n_bitrates; i++) {
113 			if (sband->bitrates[i].bitrate == 10) {
114 				sband->bitrates[i].flags |=
115 					IEEE80211_RATE_MANDATORY_B |
116 					IEEE80211_RATE_MANDATORY_G;
117 				want--;
118 			}
119 
120 			if (sband->bitrates[i].bitrate == 20 ||
121 			    sband->bitrates[i].bitrate == 55 ||
122 			    sband->bitrates[i].bitrate == 110 ||
123 			    sband->bitrates[i].bitrate == 60 ||
124 			    sband->bitrates[i].bitrate == 120 ||
125 			    sband->bitrates[i].bitrate == 240) {
126 				sband->bitrates[i].flags |=
127 					IEEE80211_RATE_MANDATORY_G;
128 				want--;
129 			}
130 
131 			if (sband->bitrates[i].bitrate != 10 &&
132 			    sband->bitrates[i].bitrate != 20 &&
133 			    sband->bitrates[i].bitrate != 55 &&
134 			    sband->bitrates[i].bitrate != 110)
135 				sband->bitrates[i].flags |=
136 					IEEE80211_RATE_ERP_G;
137 		}
138 		WARN_ON(want != 0 && want != 3 && want != 6);
139 		break;
140 	case IEEE80211_NUM_BANDS:
141 		WARN_ON(1);
142 		break;
143 	}
144 }
145 
146 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
147 {
148 	enum ieee80211_band band;
149 
150 	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
151 		if (wiphy->bands[band])
152 			set_mandatory_flags_band(wiphy->bands[band], band);
153 }
154 
155 bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
156 {
157 	int i;
158 	for (i = 0; i < wiphy->n_cipher_suites; i++)
159 		if (cipher == wiphy->cipher_suites[i])
160 			return true;
161 	return false;
162 }
163 
164 int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
165 				   struct key_params *params, int key_idx,
166 				   bool pairwise, const u8 *mac_addr)
167 {
168 	if (key_idx > 5)
169 		return -EINVAL;
170 
171 	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
172 		return -EINVAL;
173 
174 	if (pairwise && !mac_addr)
175 		return -EINVAL;
176 
177 	/*
178 	 * Disallow pairwise keys with non-zero index unless it's WEP
179 	 * or a vendor specific cipher (because current deployments use
180 	 * pairwise WEP keys with non-zero indices and for vendor specific
181 	 * ciphers this should be validated in the driver or hardware level
182 	 * - but 802.11i clearly specifies to use zero)
183 	 */
184 	if (pairwise && key_idx &&
185 	    ((params->cipher == WLAN_CIPHER_SUITE_TKIP) ||
186 	     (params->cipher == WLAN_CIPHER_SUITE_CCMP) ||
187 	     (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC)))
188 		return -EINVAL;
189 
190 	switch (params->cipher) {
191 	case WLAN_CIPHER_SUITE_WEP40:
192 		if (params->key_len != WLAN_KEY_LEN_WEP40)
193 			return -EINVAL;
194 		break;
195 	case WLAN_CIPHER_SUITE_TKIP:
196 		if (params->key_len != WLAN_KEY_LEN_TKIP)
197 			return -EINVAL;
198 		break;
199 	case WLAN_CIPHER_SUITE_CCMP:
200 		if (params->key_len != WLAN_KEY_LEN_CCMP)
201 			return -EINVAL;
202 		break;
203 	case WLAN_CIPHER_SUITE_WEP104:
204 		if (params->key_len != WLAN_KEY_LEN_WEP104)
205 			return -EINVAL;
206 		break;
207 	case WLAN_CIPHER_SUITE_AES_CMAC:
208 		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
209 			return -EINVAL;
210 		break;
211 	default:
212 		/*
213 		 * We don't know anything about this algorithm,
214 		 * allow using it -- but the driver must check
215 		 * all parameters! We still check below whether
216 		 * or not the driver supports this algorithm,
217 		 * of course.
218 		 */
219 		break;
220 	}
221 
222 	if (params->seq) {
223 		switch (params->cipher) {
224 		case WLAN_CIPHER_SUITE_WEP40:
225 		case WLAN_CIPHER_SUITE_WEP104:
226 			/* These ciphers do not use key sequence */
227 			return -EINVAL;
228 		case WLAN_CIPHER_SUITE_TKIP:
229 		case WLAN_CIPHER_SUITE_CCMP:
230 		case WLAN_CIPHER_SUITE_AES_CMAC:
231 			if (params->seq_len != 6)
232 				return -EINVAL;
233 			break;
234 		}
235 	}
236 
237 	if (!cfg80211_supported_cipher_suite(&rdev->wiphy, params->cipher))
238 		return -EINVAL;
239 
240 	return 0;
241 }
242 
243 unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
244 {
245 	unsigned int hdrlen = 24;
246 
247 	if (ieee80211_is_data(fc)) {
248 		if (ieee80211_has_a4(fc))
249 			hdrlen = 30;
250 		if (ieee80211_is_data_qos(fc)) {
251 			hdrlen += IEEE80211_QOS_CTL_LEN;
252 			if (ieee80211_has_order(fc))
253 				hdrlen += IEEE80211_HT_CTL_LEN;
254 		}
255 		goto out;
256 	}
257 
258 	if (ieee80211_is_ctl(fc)) {
259 		/*
260 		 * ACK and CTS are 10 bytes, all others 16. To see how
261 		 * to get this condition consider
262 		 *   subtype mask:   0b0000000011110000 (0x00F0)
263 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
264 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
265 		 *   bits that matter:         ^^^      (0x00E0)
266 		 *   value of those: 0b0000000011000000 (0x00C0)
267 		 */
268 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
269 			hdrlen = 10;
270 		else
271 			hdrlen = 16;
272 	}
273 out:
274 	return hdrlen;
275 }
276 EXPORT_SYMBOL(ieee80211_hdrlen);
277 
278 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
279 {
280 	const struct ieee80211_hdr *hdr =
281 			(const struct ieee80211_hdr *)skb->data;
282 	unsigned int hdrlen;
283 
284 	if (unlikely(skb->len < 10))
285 		return 0;
286 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
287 	if (unlikely(hdrlen > skb->len))
288 		return 0;
289 	return hdrlen;
290 }
291 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
292 
293 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
294 {
295 	int ae = meshhdr->flags & MESH_FLAGS_AE;
296 	/* 7.1.3.5a.2 */
297 	switch (ae) {
298 	case 0:
299 		return 6;
300 	case MESH_FLAGS_AE_A4:
301 		return 12;
302 	case MESH_FLAGS_AE_A5_A6:
303 		return 18;
304 	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
305 		return 24;
306 	default:
307 		return 6;
308 	}
309 }
310 
311 int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
312 			   enum nl80211_iftype iftype)
313 {
314 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
315 	u16 hdrlen, ethertype;
316 	u8 *payload;
317 	u8 dst[ETH_ALEN];
318 	u8 src[ETH_ALEN] __aligned(2);
319 
320 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
321 		return -1;
322 
323 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
324 
325 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
326 	 * header
327 	 * IEEE 802.11 address fields:
328 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
329 	 *   0     0   DA    SA    BSSID n/a
330 	 *   0     1   DA    BSSID SA    n/a
331 	 *   1     0   BSSID SA    DA    n/a
332 	 *   1     1   RA    TA    DA    SA
333 	 */
334 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
335 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
336 
337 	switch (hdr->frame_control &
338 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
339 	case cpu_to_le16(IEEE80211_FCTL_TODS):
340 		if (unlikely(iftype != NL80211_IFTYPE_AP &&
341 			     iftype != NL80211_IFTYPE_AP_VLAN &&
342 			     iftype != NL80211_IFTYPE_P2P_GO))
343 			return -1;
344 		break;
345 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
346 		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
347 			     iftype != NL80211_IFTYPE_MESH_POINT &&
348 			     iftype != NL80211_IFTYPE_AP_VLAN &&
349 			     iftype != NL80211_IFTYPE_STATION))
350 			return -1;
351 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
352 			struct ieee80211s_hdr *meshdr =
353 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
354 			/* make sure meshdr->flags is on the linear part */
355 			if (!pskb_may_pull(skb, hdrlen + 1))
356 				return -1;
357 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
358 				skb_copy_bits(skb, hdrlen +
359 					offsetof(struct ieee80211s_hdr, eaddr1),
360 				       	dst, ETH_ALEN);
361 				skb_copy_bits(skb, hdrlen +
362 					offsetof(struct ieee80211s_hdr, eaddr2),
363 				        src, ETH_ALEN);
364 			}
365 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
366 		}
367 		break;
368 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
369 		if ((iftype != NL80211_IFTYPE_STATION &&
370 		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
371 		     iftype != NL80211_IFTYPE_MESH_POINT) ||
372 		    (is_multicast_ether_addr(dst) &&
373 		     !compare_ether_addr(src, addr)))
374 			return -1;
375 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
376 			struct ieee80211s_hdr *meshdr =
377 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
378 			/* make sure meshdr->flags is on the linear part */
379 			if (!pskb_may_pull(skb, hdrlen + 1))
380 				return -1;
381 			if (meshdr->flags & MESH_FLAGS_AE_A4)
382 				skb_copy_bits(skb, hdrlen +
383 					offsetof(struct ieee80211s_hdr, eaddr1),
384 					src, ETH_ALEN);
385 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
386 		}
387 		break;
388 	case cpu_to_le16(0):
389 		if (iftype != NL80211_IFTYPE_ADHOC &&
390 		    iftype != NL80211_IFTYPE_STATION)
391 				return -1;
392 		break;
393 	}
394 
395 	if (!pskb_may_pull(skb, hdrlen + 8))
396 		return -1;
397 
398 	payload = skb->data + hdrlen;
399 	ethertype = (payload[6] << 8) | payload[7];
400 
401 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
402 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
403 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
404 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
405 		 * replace EtherType */
406 		skb_pull(skb, hdrlen + 6);
407 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
408 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
409 	} else {
410 		struct ethhdr *ehdr;
411 		__be16 len;
412 
413 		skb_pull(skb, hdrlen);
414 		len = htons(skb->len);
415 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
416 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
417 		memcpy(ehdr->h_source, src, ETH_ALEN);
418 		ehdr->h_proto = len;
419 	}
420 	return 0;
421 }
422 EXPORT_SYMBOL(ieee80211_data_to_8023);
423 
424 int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
425 			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
426 {
427 	struct ieee80211_hdr hdr;
428 	u16 hdrlen, ethertype;
429 	__le16 fc;
430 	const u8 *encaps_data;
431 	int encaps_len, skip_header_bytes;
432 	int nh_pos, h_pos;
433 	int head_need;
434 
435 	if (unlikely(skb->len < ETH_HLEN))
436 		return -EINVAL;
437 
438 	nh_pos = skb_network_header(skb) - skb->data;
439 	h_pos = skb_transport_header(skb) - skb->data;
440 
441 	/* convert Ethernet header to proper 802.11 header (based on
442 	 * operation mode) */
443 	ethertype = (skb->data[12] << 8) | skb->data[13];
444 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
445 
446 	switch (iftype) {
447 	case NL80211_IFTYPE_AP:
448 	case NL80211_IFTYPE_AP_VLAN:
449 	case NL80211_IFTYPE_P2P_GO:
450 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
451 		/* DA BSSID SA */
452 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
453 		memcpy(hdr.addr2, addr, ETH_ALEN);
454 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
455 		hdrlen = 24;
456 		break;
457 	case NL80211_IFTYPE_STATION:
458 	case NL80211_IFTYPE_P2P_CLIENT:
459 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
460 		/* BSSID SA DA */
461 		memcpy(hdr.addr1, bssid, ETH_ALEN);
462 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
463 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
464 		hdrlen = 24;
465 		break;
466 	case NL80211_IFTYPE_ADHOC:
467 		/* DA SA BSSID */
468 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
469 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
470 		memcpy(hdr.addr3, bssid, ETH_ALEN);
471 		hdrlen = 24;
472 		break;
473 	default:
474 		return -EOPNOTSUPP;
475 	}
476 
477 	if (qos) {
478 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
479 		hdrlen += 2;
480 	}
481 
482 	hdr.frame_control = fc;
483 	hdr.duration_id = 0;
484 	hdr.seq_ctrl = 0;
485 
486 	skip_header_bytes = ETH_HLEN;
487 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
488 		encaps_data = bridge_tunnel_header;
489 		encaps_len = sizeof(bridge_tunnel_header);
490 		skip_header_bytes -= 2;
491 	} else if (ethertype > 0x600) {
492 		encaps_data = rfc1042_header;
493 		encaps_len = sizeof(rfc1042_header);
494 		skip_header_bytes -= 2;
495 	} else {
496 		encaps_data = NULL;
497 		encaps_len = 0;
498 	}
499 
500 	skb_pull(skb, skip_header_bytes);
501 	nh_pos -= skip_header_bytes;
502 	h_pos -= skip_header_bytes;
503 
504 	head_need = hdrlen + encaps_len - skb_headroom(skb);
505 
506 	if (head_need > 0 || skb_cloned(skb)) {
507 		head_need = max(head_need, 0);
508 		if (head_need)
509 			skb_orphan(skb);
510 
511 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC))
512 			return -ENOMEM;
513 
514 		skb->truesize += head_need;
515 	}
516 
517 	if (encaps_data) {
518 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
519 		nh_pos += encaps_len;
520 		h_pos += encaps_len;
521 	}
522 
523 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
524 
525 	nh_pos += hdrlen;
526 	h_pos += hdrlen;
527 
528 	/* Update skb pointers to various headers since this modified frame
529 	 * is going to go through Linux networking code that may potentially
530 	 * need things like pointer to IP header. */
531 	skb_set_mac_header(skb, 0);
532 	skb_set_network_header(skb, nh_pos);
533 	skb_set_transport_header(skb, h_pos);
534 
535 	return 0;
536 }
537 EXPORT_SYMBOL(ieee80211_data_from_8023);
538 
539 
540 void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
541 			      const u8 *addr, enum nl80211_iftype iftype,
542 			      const unsigned int extra_headroom,
543 			      bool has_80211_header)
544 {
545 	struct sk_buff *frame = NULL;
546 	u16 ethertype;
547 	u8 *payload;
548 	const struct ethhdr *eth;
549 	int remaining, err;
550 	u8 dst[ETH_ALEN], src[ETH_ALEN];
551 
552 	if (has_80211_header) {
553 		err = ieee80211_data_to_8023(skb, addr, iftype);
554 		if (err)
555 			goto out;
556 
557 		/* skip the wrapping header */
558 		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
559 		if (!eth)
560 			goto out;
561 	} else {
562 		eth = (struct ethhdr *) skb->data;
563 	}
564 
565 	while (skb != frame) {
566 		u8 padding;
567 		__be16 len = eth->h_proto;
568 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
569 
570 		remaining = skb->len;
571 		memcpy(dst, eth->h_dest, ETH_ALEN);
572 		memcpy(src, eth->h_source, ETH_ALEN);
573 
574 		padding = (4 - subframe_len) & 0x3;
575 		/* the last MSDU has no padding */
576 		if (subframe_len > remaining)
577 			goto purge;
578 
579 		skb_pull(skb, sizeof(struct ethhdr));
580 		/* reuse skb for the last subframe */
581 		if (remaining <= subframe_len + padding)
582 			frame = skb;
583 		else {
584 			unsigned int hlen = ALIGN(extra_headroom, 4);
585 			/*
586 			 * Allocate and reserve two bytes more for payload
587 			 * alignment since sizeof(struct ethhdr) is 14.
588 			 */
589 			frame = dev_alloc_skb(hlen + subframe_len + 2);
590 			if (!frame)
591 				goto purge;
592 
593 			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
594 			memcpy(skb_put(frame, ntohs(len)), skb->data,
595 				ntohs(len));
596 
597 			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
598 							padding);
599 			if (!eth) {
600 				dev_kfree_skb(frame);
601 				goto purge;
602 			}
603 		}
604 
605 		skb_reset_network_header(frame);
606 		frame->dev = skb->dev;
607 		frame->priority = skb->priority;
608 
609 		payload = frame->data;
610 		ethertype = (payload[6] << 8) | payload[7];
611 
612 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
613 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
614 			   compare_ether_addr(payload,
615 					      bridge_tunnel_header) == 0)) {
616 			/* remove RFC1042 or Bridge-Tunnel
617 			 * encapsulation and replace EtherType */
618 			skb_pull(frame, 6);
619 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
620 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
621 		} else {
622 			memcpy(skb_push(frame, sizeof(__be16)), &len,
623 				sizeof(__be16));
624 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
625 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
626 		}
627 		__skb_queue_tail(list, frame);
628 	}
629 
630 	return;
631 
632  purge:
633 	__skb_queue_purge(list);
634  out:
635 	dev_kfree_skb(skb);
636 }
637 EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
638 
639 /* Given a data frame determine the 802.1p/1d tag to use. */
640 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
641 {
642 	unsigned int dscp;
643 
644 	/* skb->priority values from 256->263 are magic values to
645 	 * directly indicate a specific 802.1d priority.  This is used
646 	 * to allow 802.1d priority to be passed directly in from VLAN
647 	 * tags, etc.
648 	 */
649 	if (skb->priority >= 256 && skb->priority <= 263)
650 		return skb->priority - 256;
651 
652 	switch (skb->protocol) {
653 	case htons(ETH_P_IP):
654 		dscp = ipv4_get_dsfield(ip_hdr(skb)) & 0xfc;
655 		break;
656 	case htons(ETH_P_IPV6):
657 		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & 0xfc;
658 		break;
659 	default:
660 		return 0;
661 	}
662 
663 	return dscp >> 5;
664 }
665 EXPORT_SYMBOL(cfg80211_classify8021d);
666 
667 const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
668 {
669 	u8 *end, *pos;
670 
671 	pos = bss->information_elements;
672 	if (pos == NULL)
673 		return NULL;
674 	end = pos + bss->len_information_elements;
675 
676 	while (pos + 1 < end) {
677 		if (pos + 2 + pos[1] > end)
678 			break;
679 		if (pos[0] == ie)
680 			return pos;
681 		pos += 2 + pos[1];
682 	}
683 
684 	return NULL;
685 }
686 EXPORT_SYMBOL(ieee80211_bss_get_ie);
687 
688 void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
689 {
690 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
691 	struct net_device *dev = wdev->netdev;
692 	int i;
693 
694 	if (!wdev->connect_keys)
695 		return;
696 
697 	for (i = 0; i < 6; i++) {
698 		if (!wdev->connect_keys->params[i].cipher)
699 			continue;
700 		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,
701 					&wdev->connect_keys->params[i])) {
702 			netdev_err(dev, "failed to set key %d\n", i);
703 			continue;
704 		}
705 		if (wdev->connect_keys->def == i)
706 			if (rdev->ops->set_default_key(wdev->wiphy, dev,
707 						       i, true, true)) {
708 				netdev_err(dev, "failed to set defkey %d\n", i);
709 				continue;
710 			}
711 		if (wdev->connect_keys->defmgmt == i)
712 			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
713 				netdev_err(dev, "failed to set mgtdef %d\n", i);
714 	}
715 
716 	kfree(wdev->connect_keys);
717 	wdev->connect_keys = NULL;
718 }
719 
720 static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
721 {
722 	struct cfg80211_event *ev;
723 	unsigned long flags;
724 	const u8 *bssid = NULL;
725 
726 	spin_lock_irqsave(&wdev->event_lock, flags);
727 	while (!list_empty(&wdev->event_list)) {
728 		ev = list_first_entry(&wdev->event_list,
729 				      struct cfg80211_event, list);
730 		list_del(&ev->list);
731 		spin_unlock_irqrestore(&wdev->event_lock, flags);
732 
733 		wdev_lock(wdev);
734 		switch (ev->type) {
735 		case EVENT_CONNECT_RESULT:
736 			if (!is_zero_ether_addr(ev->cr.bssid))
737 				bssid = ev->cr.bssid;
738 			__cfg80211_connect_result(
739 				wdev->netdev, bssid,
740 				ev->cr.req_ie, ev->cr.req_ie_len,
741 				ev->cr.resp_ie, ev->cr.resp_ie_len,
742 				ev->cr.status,
743 				ev->cr.status == WLAN_STATUS_SUCCESS,
744 				NULL);
745 			break;
746 		case EVENT_ROAMED:
747 			__cfg80211_roamed(wdev, ev->rm.bss, ev->rm.req_ie,
748 					  ev->rm.req_ie_len, ev->rm.resp_ie,
749 					  ev->rm.resp_ie_len);
750 			break;
751 		case EVENT_DISCONNECTED:
752 			__cfg80211_disconnected(wdev->netdev,
753 						ev->dc.ie, ev->dc.ie_len,
754 						ev->dc.reason, true);
755 			break;
756 		case EVENT_IBSS_JOINED:
757 			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
758 			break;
759 		}
760 		wdev_unlock(wdev);
761 
762 		kfree(ev);
763 
764 		spin_lock_irqsave(&wdev->event_lock, flags);
765 	}
766 	spin_unlock_irqrestore(&wdev->event_lock, flags);
767 }
768 
769 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
770 {
771 	struct wireless_dev *wdev;
772 
773 	ASSERT_RTNL();
774 	ASSERT_RDEV_LOCK(rdev);
775 
776 	mutex_lock(&rdev->devlist_mtx);
777 
778 	list_for_each_entry(wdev, &rdev->netdev_list, list)
779 		cfg80211_process_wdev_events(wdev);
780 
781 	mutex_unlock(&rdev->devlist_mtx);
782 }
783 
784 int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
785 			  struct net_device *dev, enum nl80211_iftype ntype,
786 			  u32 *flags, struct vif_params *params)
787 {
788 	int err;
789 	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
790 
791 	ASSERT_RDEV_LOCK(rdev);
792 
793 	/* don't support changing VLANs, you just re-create them */
794 	if (otype == NL80211_IFTYPE_AP_VLAN)
795 		return -EOPNOTSUPP;
796 
797 	if (!rdev->ops->change_virtual_intf ||
798 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
799 		return -EOPNOTSUPP;
800 
801 	/* if it's part of a bridge, reject changing type to station/ibss */
802 	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&
803 	    (ntype == NL80211_IFTYPE_ADHOC ||
804 	     ntype == NL80211_IFTYPE_STATION ||
805 	     ntype == NL80211_IFTYPE_P2P_CLIENT))
806 		return -EBUSY;
807 
808 	if (ntype != otype) {
809 		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
810 						    ntype);
811 		if (err)
812 			return err;
813 
814 		dev->ieee80211_ptr->use_4addr = false;
815 		dev->ieee80211_ptr->mesh_id_up_len = 0;
816 
817 		switch (otype) {
818 		case NL80211_IFTYPE_ADHOC:
819 			cfg80211_leave_ibss(rdev, dev, false);
820 			break;
821 		case NL80211_IFTYPE_STATION:
822 		case NL80211_IFTYPE_P2P_CLIENT:
823 			cfg80211_disconnect(rdev, dev,
824 					    WLAN_REASON_DEAUTH_LEAVING, true);
825 			break;
826 		case NL80211_IFTYPE_MESH_POINT:
827 			/* mesh should be handled? */
828 			break;
829 		default:
830 			break;
831 		}
832 
833 		cfg80211_process_rdev_events(rdev);
834 	}
835 
836 	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
837 					     ntype, flags, params);
838 
839 	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
840 
841 	if (!err && params && params->use_4addr != -1)
842 		dev->ieee80211_ptr->use_4addr = params->use_4addr;
843 
844 	if (!err) {
845 		dev->priv_flags &= ~IFF_DONT_BRIDGE;
846 		switch (ntype) {
847 		case NL80211_IFTYPE_STATION:
848 			if (dev->ieee80211_ptr->use_4addr)
849 				break;
850 			/* fall through */
851 		case NL80211_IFTYPE_P2P_CLIENT:
852 		case NL80211_IFTYPE_ADHOC:
853 			dev->priv_flags |= IFF_DONT_BRIDGE;
854 			break;
855 		case NL80211_IFTYPE_P2P_GO:
856 		case NL80211_IFTYPE_AP:
857 		case NL80211_IFTYPE_AP_VLAN:
858 		case NL80211_IFTYPE_WDS:
859 		case NL80211_IFTYPE_MESH_POINT:
860 			/* bridging OK */
861 			break;
862 		case NL80211_IFTYPE_MONITOR:
863 			/* monitor can't bridge anyway */
864 			break;
865 		case NL80211_IFTYPE_UNSPECIFIED:
866 		case NUM_NL80211_IFTYPES:
867 			/* not happening */
868 			break;
869 		}
870 	}
871 
872 	return err;
873 }
874 
875 u16 cfg80211_calculate_bitrate(struct rate_info *rate)
876 {
877 	int modulation, streams, bitrate;
878 
879 	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
880 		return rate->legacy;
881 
882 	/* the formula below does only work for MCS values smaller than 32 */
883 	if (rate->mcs >= 32)
884 		return 0;
885 
886 	modulation = rate->mcs & 7;
887 	streams = (rate->mcs >> 3) + 1;
888 
889 	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
890 			13500000 : 6500000;
891 
892 	if (modulation < 4)
893 		bitrate *= (modulation + 1);
894 	else if (modulation == 4)
895 		bitrate *= (modulation + 2);
896 	else
897 		bitrate *= (modulation + 3);
898 
899 	bitrate *= streams;
900 
901 	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
902 		bitrate = (bitrate / 9) * 10;
903 
904 	/* do NOT round down here */
905 	return (bitrate + 50000) / 100000;
906 }
907 EXPORT_SYMBOL(cfg80211_calculate_bitrate);
908 
909 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
910 				 u32 beacon_int)
911 {
912 	struct wireless_dev *wdev;
913 	int res = 0;
914 
915 	if (!beacon_int)
916 		return -EINVAL;
917 
918 	mutex_lock(&rdev->devlist_mtx);
919 
920 	list_for_each_entry(wdev, &rdev->netdev_list, list) {
921 		if (!wdev->beacon_interval)
922 			continue;
923 		if (wdev->beacon_interval != beacon_int) {
924 			res = -EINVAL;
925 			break;
926 		}
927 	}
928 
929 	mutex_unlock(&rdev->devlist_mtx);
930 
931 	return res;
932 }
933 
934 int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
935 				  struct wireless_dev *wdev,
936 				  enum nl80211_iftype iftype)
937 {
938 	struct wireless_dev *wdev_iter;
939 	int num[NUM_NL80211_IFTYPES];
940 	int total = 1;
941 	int i, j;
942 
943 	ASSERT_RTNL();
944 
945 	/* Always allow software iftypes */
946 	if (rdev->wiphy.software_iftypes & BIT(iftype))
947 		return 0;
948 
949 	/*
950 	 * Drivers will gradually all set this flag, until all
951 	 * have it we only enforce for those that set it.
952 	 */
953 	if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS))
954 		return 0;
955 
956 	memset(num, 0, sizeof(num));
957 
958 	num[iftype] = 1;
959 
960 	mutex_lock(&rdev->devlist_mtx);
961 	list_for_each_entry(wdev_iter, &rdev->netdev_list, list) {
962 		if (wdev_iter == wdev)
963 			continue;
964 		if (!netif_running(wdev_iter->netdev))
965 			continue;
966 
967 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
968 			continue;
969 
970 		num[wdev_iter->iftype]++;
971 		total++;
972 	}
973 	mutex_unlock(&rdev->devlist_mtx);
974 
975 	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
976 		const struct ieee80211_iface_combination *c;
977 		struct ieee80211_iface_limit *limits;
978 
979 		c = &rdev->wiphy.iface_combinations[i];
980 
981 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
982 				 GFP_KERNEL);
983 		if (!limits)
984 			return -ENOMEM;
985 		if (total > c->max_interfaces)
986 			goto cont;
987 
988 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
989 			if (rdev->wiphy.software_iftypes & BIT(iftype))
990 				continue;
991 			for (j = 0; j < c->n_limits; j++) {
992 				if (!(limits[j].types & iftype))
993 					continue;
994 				if (limits[j].max < num[iftype])
995 					goto cont;
996 				limits[j].max -= num[iftype];
997 			}
998 		}
999 		/* yay, it fits */
1000 		kfree(limits);
1001 		return 0;
1002  cont:
1003 		kfree(limits);
1004 	}
1005 
1006 	return -EBUSY;
1007 }
1008 
1009 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
1010 			   const u8 *rates, unsigned int n_rates,
1011 			   u32 *mask)
1012 {
1013 	int i, j;
1014 
1015 	if (!sband)
1016 		return -EINVAL;
1017 
1018 	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
1019 		return -EINVAL;
1020 
1021 	*mask = 0;
1022 
1023 	for (i = 0; i < n_rates; i++) {
1024 		int rate = (rates[i] & 0x7f) * 5;
1025 		bool found = false;
1026 
1027 		for (j = 0; j < sband->n_bitrates; j++) {
1028 			if (sband->bitrates[j].bitrate == rate) {
1029 				found = true;
1030 				*mask |= BIT(j);
1031 				break;
1032 			}
1033 		}
1034 		if (!found)
1035 			return -EINVAL;
1036 	}
1037 
1038 	/*
1039 	 * mask must have at least one bit set here since we
1040 	 * didn't accept a 0-length rates array nor allowed
1041 	 * entries in the array that didn't exist
1042 	 */
1043 
1044 	return 0;
1045 }
1046 
1047 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
1048 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
1049 const unsigned char rfc1042_header[] __aligned(2) =
1050 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
1051 EXPORT_SYMBOL(rfc1042_header);
1052 
1053 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
1054 const unsigned char bridge_tunnel_header[] __aligned(2) =
1055 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
1056 EXPORT_SYMBOL(bridge_tunnel_header);
1057