xref: /openbmc/linux/net/wireless/util.c (revision 9c1f8594)
1 /*
2  * Wireless utility functions
3  *
4  * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/bitops.h>
7 #include <linux/etherdevice.h>
8 #include <linux/slab.h>
9 #include <net/cfg80211.h>
10 #include <net/ip.h>
11 #include "core.h"
12 
13 struct ieee80211_rate *
14 ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
15 			    u32 basic_rates, int bitrate)
16 {
17 	struct ieee80211_rate *result = &sband->bitrates[0];
18 	int i;
19 
20 	for (i = 0; i < sband->n_bitrates; i++) {
21 		if (!(basic_rates & BIT(i)))
22 			continue;
23 		if (sband->bitrates[i].bitrate > bitrate)
24 			continue;
25 		result = &sband->bitrates[i];
26 	}
27 
28 	return result;
29 }
30 EXPORT_SYMBOL(ieee80211_get_response_rate);
31 
32 int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)
33 {
34 	/* see 802.11 17.3.8.3.2 and Annex J
35 	 * there are overlapping channel numbers in 5GHz and 2GHz bands */
36 	if (band == IEEE80211_BAND_5GHZ) {
37 		if (chan >= 182 && chan <= 196)
38 			return 4000 + chan * 5;
39 		else
40 			return 5000 + chan * 5;
41 	} else { /* IEEE80211_BAND_2GHZ */
42 		if (chan == 14)
43 			return 2484;
44 		else if (chan < 14)
45 			return 2407 + chan * 5;
46 		else
47 			return 0; /* not supported */
48 	}
49 }
50 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
51 
52 int ieee80211_frequency_to_channel(int freq)
53 {
54 	/* see 802.11 17.3.8.3.2 and Annex J */
55 	if (freq == 2484)
56 		return 14;
57 	else if (freq < 2484)
58 		return (freq - 2407) / 5;
59 	else if (freq >= 4910 && freq <= 4980)
60 		return (freq - 4000) / 5;
61 	else
62 		return (freq - 5000) / 5;
63 }
64 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
65 
66 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
67 						  int freq)
68 {
69 	enum ieee80211_band band;
70 	struct ieee80211_supported_band *sband;
71 	int i;
72 
73 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
74 		sband = wiphy->bands[band];
75 
76 		if (!sband)
77 			continue;
78 
79 		for (i = 0; i < sband->n_channels; i++) {
80 			if (sband->channels[i].center_freq == freq)
81 				return &sband->channels[i];
82 		}
83 	}
84 
85 	return NULL;
86 }
87 EXPORT_SYMBOL(__ieee80211_get_channel);
88 
89 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
90 				     enum ieee80211_band band)
91 {
92 	int i, want;
93 
94 	switch (band) {
95 	case IEEE80211_BAND_5GHZ:
96 		want = 3;
97 		for (i = 0; i < sband->n_bitrates; i++) {
98 			if (sband->bitrates[i].bitrate == 60 ||
99 			    sband->bitrates[i].bitrate == 120 ||
100 			    sband->bitrates[i].bitrate == 240) {
101 				sband->bitrates[i].flags |=
102 					IEEE80211_RATE_MANDATORY_A;
103 				want--;
104 			}
105 		}
106 		WARN_ON(want);
107 		break;
108 	case IEEE80211_BAND_2GHZ:
109 		want = 7;
110 		for (i = 0; i < sband->n_bitrates; i++) {
111 			if (sband->bitrates[i].bitrate == 10) {
112 				sband->bitrates[i].flags |=
113 					IEEE80211_RATE_MANDATORY_B |
114 					IEEE80211_RATE_MANDATORY_G;
115 				want--;
116 			}
117 
118 			if (sband->bitrates[i].bitrate == 20 ||
119 			    sband->bitrates[i].bitrate == 55 ||
120 			    sband->bitrates[i].bitrate == 110 ||
121 			    sband->bitrates[i].bitrate == 60 ||
122 			    sband->bitrates[i].bitrate == 120 ||
123 			    sband->bitrates[i].bitrate == 240) {
124 				sband->bitrates[i].flags |=
125 					IEEE80211_RATE_MANDATORY_G;
126 				want--;
127 			}
128 
129 			if (sband->bitrates[i].bitrate != 10 &&
130 			    sband->bitrates[i].bitrate != 20 &&
131 			    sband->bitrates[i].bitrate != 55 &&
132 			    sband->bitrates[i].bitrate != 110)
133 				sband->bitrates[i].flags |=
134 					IEEE80211_RATE_ERP_G;
135 		}
136 		WARN_ON(want != 0 && want != 3 && want != 6);
137 		break;
138 	case IEEE80211_NUM_BANDS:
139 		WARN_ON(1);
140 		break;
141 	}
142 }
143 
144 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
145 {
146 	enum ieee80211_band band;
147 
148 	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
149 		if (wiphy->bands[band])
150 			set_mandatory_flags_band(wiphy->bands[band], band);
151 }
152 
153 int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
154 				   struct key_params *params, int key_idx,
155 				   bool pairwise, const u8 *mac_addr)
156 {
157 	int i;
158 
159 	if (key_idx > 5)
160 		return -EINVAL;
161 
162 	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
163 		return -EINVAL;
164 
165 	if (pairwise && !mac_addr)
166 		return -EINVAL;
167 
168 	/*
169 	 * Disallow pairwise keys with non-zero index unless it's WEP
170 	 * or a vendor specific cipher (because current deployments use
171 	 * pairwise WEP keys with non-zero indices and for vendor specific
172 	 * ciphers this should be validated in the driver or hardware level
173 	 * - but 802.11i clearly specifies to use zero)
174 	 */
175 	if (pairwise && key_idx &&
176 	    ((params->cipher == WLAN_CIPHER_SUITE_TKIP) ||
177 	     (params->cipher == WLAN_CIPHER_SUITE_CCMP) ||
178 	     (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC)))
179 		return -EINVAL;
180 
181 	switch (params->cipher) {
182 	case WLAN_CIPHER_SUITE_WEP40:
183 		if (params->key_len != WLAN_KEY_LEN_WEP40)
184 			return -EINVAL;
185 		break;
186 	case WLAN_CIPHER_SUITE_TKIP:
187 		if (params->key_len != WLAN_KEY_LEN_TKIP)
188 			return -EINVAL;
189 		break;
190 	case WLAN_CIPHER_SUITE_CCMP:
191 		if (params->key_len != WLAN_KEY_LEN_CCMP)
192 			return -EINVAL;
193 		break;
194 	case WLAN_CIPHER_SUITE_WEP104:
195 		if (params->key_len != WLAN_KEY_LEN_WEP104)
196 			return -EINVAL;
197 		break;
198 	case WLAN_CIPHER_SUITE_AES_CMAC:
199 		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
200 			return -EINVAL;
201 		break;
202 	default:
203 		/*
204 		 * We don't know anything about this algorithm,
205 		 * allow using it -- but the driver must check
206 		 * all parameters! We still check below whether
207 		 * or not the driver supports this algorithm,
208 		 * of course.
209 		 */
210 		break;
211 	}
212 
213 	if (params->seq) {
214 		switch (params->cipher) {
215 		case WLAN_CIPHER_SUITE_WEP40:
216 		case WLAN_CIPHER_SUITE_WEP104:
217 			/* These ciphers do not use key sequence */
218 			return -EINVAL;
219 		case WLAN_CIPHER_SUITE_TKIP:
220 		case WLAN_CIPHER_SUITE_CCMP:
221 		case WLAN_CIPHER_SUITE_AES_CMAC:
222 			if (params->seq_len != 6)
223 				return -EINVAL;
224 			break;
225 		}
226 	}
227 
228 	for (i = 0; i < rdev->wiphy.n_cipher_suites; i++)
229 		if (params->cipher == rdev->wiphy.cipher_suites[i])
230 			break;
231 	if (i == rdev->wiphy.n_cipher_suites)
232 		return -EINVAL;
233 
234 	return 0;
235 }
236 
237 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
238 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
239 const unsigned char rfc1042_header[] __aligned(2) =
240 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
241 EXPORT_SYMBOL(rfc1042_header);
242 
243 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
244 const unsigned char bridge_tunnel_header[] __aligned(2) =
245 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
246 EXPORT_SYMBOL(bridge_tunnel_header);
247 
248 unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
249 {
250 	unsigned int hdrlen = 24;
251 
252 	if (ieee80211_is_data(fc)) {
253 		if (ieee80211_has_a4(fc))
254 			hdrlen = 30;
255 		if (ieee80211_is_data_qos(fc)) {
256 			hdrlen += IEEE80211_QOS_CTL_LEN;
257 			if (ieee80211_has_order(fc))
258 				hdrlen += IEEE80211_HT_CTL_LEN;
259 		}
260 		goto out;
261 	}
262 
263 	if (ieee80211_is_ctl(fc)) {
264 		/*
265 		 * ACK and CTS are 10 bytes, all others 16. To see how
266 		 * to get this condition consider
267 		 *   subtype mask:   0b0000000011110000 (0x00F0)
268 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
269 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
270 		 *   bits that matter:         ^^^      (0x00E0)
271 		 *   value of those: 0b0000000011000000 (0x00C0)
272 		 */
273 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
274 			hdrlen = 10;
275 		else
276 			hdrlen = 16;
277 	}
278 out:
279 	return hdrlen;
280 }
281 EXPORT_SYMBOL(ieee80211_hdrlen);
282 
283 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
284 {
285 	const struct ieee80211_hdr *hdr =
286 			(const struct ieee80211_hdr *)skb->data;
287 	unsigned int hdrlen;
288 
289 	if (unlikely(skb->len < 10))
290 		return 0;
291 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
292 	if (unlikely(hdrlen > skb->len))
293 		return 0;
294 	return hdrlen;
295 }
296 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
297 
298 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
299 {
300 	int ae = meshhdr->flags & MESH_FLAGS_AE;
301 	/* 7.1.3.5a.2 */
302 	switch (ae) {
303 	case 0:
304 		return 6;
305 	case MESH_FLAGS_AE_A4:
306 		return 12;
307 	case MESH_FLAGS_AE_A5_A6:
308 		return 18;
309 	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
310 		return 24;
311 	default:
312 		return 6;
313 	}
314 }
315 
316 int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
317 			   enum nl80211_iftype iftype)
318 {
319 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
320 	u16 hdrlen, ethertype;
321 	u8 *payload;
322 	u8 dst[ETH_ALEN];
323 	u8 src[ETH_ALEN] __aligned(2);
324 
325 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
326 		return -1;
327 
328 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
329 
330 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
331 	 * header
332 	 * IEEE 802.11 address fields:
333 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
334 	 *   0     0   DA    SA    BSSID n/a
335 	 *   0     1   DA    BSSID SA    n/a
336 	 *   1     0   BSSID SA    DA    n/a
337 	 *   1     1   RA    TA    DA    SA
338 	 */
339 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
340 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
341 
342 	switch (hdr->frame_control &
343 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
344 	case cpu_to_le16(IEEE80211_FCTL_TODS):
345 		if (unlikely(iftype != NL80211_IFTYPE_AP &&
346 			     iftype != NL80211_IFTYPE_AP_VLAN &&
347 			     iftype != NL80211_IFTYPE_P2P_GO))
348 			return -1;
349 		break;
350 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
351 		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
352 			     iftype != NL80211_IFTYPE_MESH_POINT &&
353 			     iftype != NL80211_IFTYPE_AP_VLAN &&
354 			     iftype != NL80211_IFTYPE_STATION))
355 			return -1;
356 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
357 			struct ieee80211s_hdr *meshdr =
358 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
359 			/* make sure meshdr->flags is on the linear part */
360 			if (!pskb_may_pull(skb, hdrlen + 1))
361 				return -1;
362 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
363 				skb_copy_bits(skb, hdrlen +
364 					offsetof(struct ieee80211s_hdr, eaddr1),
365 				       	dst, ETH_ALEN);
366 				skb_copy_bits(skb, hdrlen +
367 					offsetof(struct ieee80211s_hdr, eaddr2),
368 				        src, ETH_ALEN);
369 			}
370 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
371 		}
372 		break;
373 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
374 		if ((iftype != NL80211_IFTYPE_STATION &&
375 		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
376 		     iftype != NL80211_IFTYPE_MESH_POINT) ||
377 		    (is_multicast_ether_addr(dst) &&
378 		     !compare_ether_addr(src, addr)))
379 			return -1;
380 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
381 			struct ieee80211s_hdr *meshdr =
382 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
383 			/* make sure meshdr->flags is on the linear part */
384 			if (!pskb_may_pull(skb, hdrlen + 1))
385 				return -1;
386 			if (meshdr->flags & MESH_FLAGS_AE_A4)
387 				skb_copy_bits(skb, hdrlen +
388 					offsetof(struct ieee80211s_hdr, eaddr1),
389 					src, ETH_ALEN);
390 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
391 		}
392 		break;
393 	case cpu_to_le16(0):
394 		if (iftype != NL80211_IFTYPE_ADHOC)
395 			return -1;
396 		break;
397 	}
398 
399 	if (!pskb_may_pull(skb, hdrlen + 8))
400 		return -1;
401 
402 	payload = skb->data + hdrlen;
403 	ethertype = (payload[6] << 8) | payload[7];
404 
405 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
406 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
407 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
408 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
409 		 * replace EtherType */
410 		skb_pull(skb, hdrlen + 6);
411 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
412 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
413 	} else {
414 		struct ethhdr *ehdr;
415 		__be16 len;
416 
417 		skb_pull(skb, hdrlen);
418 		len = htons(skb->len);
419 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
420 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
421 		memcpy(ehdr->h_source, src, ETH_ALEN);
422 		ehdr->h_proto = len;
423 	}
424 	return 0;
425 }
426 EXPORT_SYMBOL(ieee80211_data_to_8023);
427 
428 int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
429 			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
430 {
431 	struct ieee80211_hdr hdr;
432 	u16 hdrlen, ethertype;
433 	__le16 fc;
434 	const u8 *encaps_data;
435 	int encaps_len, skip_header_bytes;
436 	int nh_pos, h_pos;
437 	int head_need;
438 
439 	if (unlikely(skb->len < ETH_HLEN))
440 		return -EINVAL;
441 
442 	nh_pos = skb_network_header(skb) - skb->data;
443 	h_pos = skb_transport_header(skb) - skb->data;
444 
445 	/* convert Ethernet header to proper 802.11 header (based on
446 	 * operation mode) */
447 	ethertype = (skb->data[12] << 8) | skb->data[13];
448 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
449 
450 	switch (iftype) {
451 	case NL80211_IFTYPE_AP:
452 	case NL80211_IFTYPE_AP_VLAN:
453 	case NL80211_IFTYPE_P2P_GO:
454 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
455 		/* DA BSSID SA */
456 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
457 		memcpy(hdr.addr2, addr, ETH_ALEN);
458 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
459 		hdrlen = 24;
460 		break;
461 	case NL80211_IFTYPE_STATION:
462 	case NL80211_IFTYPE_P2P_CLIENT:
463 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
464 		/* BSSID SA DA */
465 		memcpy(hdr.addr1, bssid, ETH_ALEN);
466 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
467 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
468 		hdrlen = 24;
469 		break;
470 	case NL80211_IFTYPE_ADHOC:
471 		/* DA SA BSSID */
472 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
473 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
474 		memcpy(hdr.addr3, bssid, ETH_ALEN);
475 		hdrlen = 24;
476 		break;
477 	default:
478 		return -EOPNOTSUPP;
479 	}
480 
481 	if (qos) {
482 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
483 		hdrlen += 2;
484 	}
485 
486 	hdr.frame_control = fc;
487 	hdr.duration_id = 0;
488 	hdr.seq_ctrl = 0;
489 
490 	skip_header_bytes = ETH_HLEN;
491 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
492 		encaps_data = bridge_tunnel_header;
493 		encaps_len = sizeof(bridge_tunnel_header);
494 		skip_header_bytes -= 2;
495 	} else if (ethertype > 0x600) {
496 		encaps_data = rfc1042_header;
497 		encaps_len = sizeof(rfc1042_header);
498 		skip_header_bytes -= 2;
499 	} else {
500 		encaps_data = NULL;
501 		encaps_len = 0;
502 	}
503 
504 	skb_pull(skb, skip_header_bytes);
505 	nh_pos -= skip_header_bytes;
506 	h_pos -= skip_header_bytes;
507 
508 	head_need = hdrlen + encaps_len - skb_headroom(skb);
509 
510 	if (head_need > 0 || skb_cloned(skb)) {
511 		head_need = max(head_need, 0);
512 		if (head_need)
513 			skb_orphan(skb);
514 
515 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) {
516 			pr_err("failed to reallocate Tx buffer\n");
517 			return -ENOMEM;
518 		}
519 		skb->truesize += head_need;
520 	}
521 
522 	if (encaps_data) {
523 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
524 		nh_pos += encaps_len;
525 		h_pos += encaps_len;
526 	}
527 
528 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
529 
530 	nh_pos += hdrlen;
531 	h_pos += hdrlen;
532 
533 	/* Update skb pointers to various headers since this modified frame
534 	 * is going to go through Linux networking code that may potentially
535 	 * need things like pointer to IP header. */
536 	skb_set_mac_header(skb, 0);
537 	skb_set_network_header(skb, nh_pos);
538 	skb_set_transport_header(skb, h_pos);
539 
540 	return 0;
541 }
542 EXPORT_SYMBOL(ieee80211_data_from_8023);
543 
544 
545 void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
546 			      const u8 *addr, enum nl80211_iftype iftype,
547 			      const unsigned int extra_headroom,
548 			      bool has_80211_header)
549 {
550 	struct sk_buff *frame = NULL;
551 	u16 ethertype;
552 	u8 *payload;
553 	const struct ethhdr *eth;
554 	int remaining, err;
555 	u8 dst[ETH_ALEN], src[ETH_ALEN];
556 
557 	if (has_80211_header) {
558 		err = ieee80211_data_to_8023(skb, addr, iftype);
559 		if (err)
560 			goto out;
561 
562 		/* skip the wrapping header */
563 		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
564 		if (!eth)
565 			goto out;
566 	} else {
567 		eth = (struct ethhdr *) skb->data;
568 	}
569 
570 	while (skb != frame) {
571 		u8 padding;
572 		__be16 len = eth->h_proto;
573 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
574 
575 		remaining = skb->len;
576 		memcpy(dst, eth->h_dest, ETH_ALEN);
577 		memcpy(src, eth->h_source, ETH_ALEN);
578 
579 		padding = (4 - subframe_len) & 0x3;
580 		/* the last MSDU has no padding */
581 		if (subframe_len > remaining)
582 			goto purge;
583 
584 		skb_pull(skb, sizeof(struct ethhdr));
585 		/* reuse skb for the last subframe */
586 		if (remaining <= subframe_len + padding)
587 			frame = skb;
588 		else {
589 			unsigned int hlen = ALIGN(extra_headroom, 4);
590 			/*
591 			 * Allocate and reserve two bytes more for payload
592 			 * alignment since sizeof(struct ethhdr) is 14.
593 			 */
594 			frame = dev_alloc_skb(hlen + subframe_len + 2);
595 			if (!frame)
596 				goto purge;
597 
598 			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
599 			memcpy(skb_put(frame, ntohs(len)), skb->data,
600 				ntohs(len));
601 
602 			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
603 							padding);
604 			if (!eth) {
605 				dev_kfree_skb(frame);
606 				goto purge;
607 			}
608 		}
609 
610 		skb_reset_network_header(frame);
611 		frame->dev = skb->dev;
612 		frame->priority = skb->priority;
613 
614 		payload = frame->data;
615 		ethertype = (payload[6] << 8) | payload[7];
616 
617 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
618 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
619 			   compare_ether_addr(payload,
620 					      bridge_tunnel_header) == 0)) {
621 			/* remove RFC1042 or Bridge-Tunnel
622 			 * encapsulation and replace EtherType */
623 			skb_pull(frame, 6);
624 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
625 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
626 		} else {
627 			memcpy(skb_push(frame, sizeof(__be16)), &len,
628 				sizeof(__be16));
629 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
630 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
631 		}
632 		__skb_queue_tail(list, frame);
633 	}
634 
635 	return;
636 
637  purge:
638 	__skb_queue_purge(list);
639  out:
640 	dev_kfree_skb(skb);
641 }
642 EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
643 
644 /* Given a data frame determine the 802.1p/1d tag to use. */
645 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
646 {
647 	unsigned int dscp;
648 
649 	/* skb->priority values from 256->263 are magic values to
650 	 * directly indicate a specific 802.1d priority.  This is used
651 	 * to allow 802.1d priority to be passed directly in from VLAN
652 	 * tags, etc.
653 	 */
654 	if (skb->priority >= 256 && skb->priority <= 263)
655 		return skb->priority - 256;
656 
657 	switch (skb->protocol) {
658 	case htons(ETH_P_IP):
659 		dscp = ip_hdr(skb)->tos & 0xfc;
660 		break;
661 	default:
662 		return 0;
663 	}
664 
665 	return dscp >> 5;
666 }
667 EXPORT_SYMBOL(cfg80211_classify8021d);
668 
669 const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
670 {
671 	u8 *end, *pos;
672 
673 	pos = bss->information_elements;
674 	if (pos == NULL)
675 		return NULL;
676 	end = pos + bss->len_information_elements;
677 
678 	while (pos + 1 < end) {
679 		if (pos + 2 + pos[1] > end)
680 			break;
681 		if (pos[0] == ie)
682 			return pos;
683 		pos += 2 + pos[1];
684 	}
685 
686 	return NULL;
687 }
688 EXPORT_SYMBOL(ieee80211_bss_get_ie);
689 
690 void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
691 {
692 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
693 	struct net_device *dev = wdev->netdev;
694 	int i;
695 
696 	if (!wdev->connect_keys)
697 		return;
698 
699 	for (i = 0; i < 6; i++) {
700 		if (!wdev->connect_keys->params[i].cipher)
701 			continue;
702 		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,
703 					&wdev->connect_keys->params[i])) {
704 			netdev_err(dev, "failed to set key %d\n", i);
705 			continue;
706 		}
707 		if (wdev->connect_keys->def == i)
708 			if (rdev->ops->set_default_key(wdev->wiphy, dev,
709 						       i, true, true)) {
710 				netdev_err(dev, "failed to set defkey %d\n", i);
711 				continue;
712 			}
713 		if (wdev->connect_keys->defmgmt == i)
714 			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
715 				netdev_err(dev, "failed to set mgtdef %d\n", i);
716 	}
717 
718 	kfree(wdev->connect_keys);
719 	wdev->connect_keys = NULL;
720 }
721 
722 static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
723 {
724 	struct cfg80211_event *ev;
725 	unsigned long flags;
726 	const u8 *bssid = NULL;
727 
728 	spin_lock_irqsave(&wdev->event_lock, flags);
729 	while (!list_empty(&wdev->event_list)) {
730 		ev = list_first_entry(&wdev->event_list,
731 				      struct cfg80211_event, list);
732 		list_del(&ev->list);
733 		spin_unlock_irqrestore(&wdev->event_lock, flags);
734 
735 		wdev_lock(wdev);
736 		switch (ev->type) {
737 		case EVENT_CONNECT_RESULT:
738 			if (!is_zero_ether_addr(ev->cr.bssid))
739 				bssid = ev->cr.bssid;
740 			__cfg80211_connect_result(
741 				wdev->netdev, bssid,
742 				ev->cr.req_ie, ev->cr.req_ie_len,
743 				ev->cr.resp_ie, ev->cr.resp_ie_len,
744 				ev->cr.status,
745 				ev->cr.status == WLAN_STATUS_SUCCESS,
746 				NULL);
747 			break;
748 		case EVENT_ROAMED:
749 			__cfg80211_roamed(wdev, ev->rm.channel, ev->rm.bssid,
750 					  ev->rm.req_ie, ev->rm.req_ie_len,
751 					  ev->rm.resp_ie, ev->rm.resp_ie_len);
752 			break;
753 		case EVENT_DISCONNECTED:
754 			__cfg80211_disconnected(wdev->netdev,
755 						ev->dc.ie, ev->dc.ie_len,
756 						ev->dc.reason, true);
757 			break;
758 		case EVENT_IBSS_JOINED:
759 			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
760 			break;
761 		}
762 		wdev_unlock(wdev);
763 
764 		kfree(ev);
765 
766 		spin_lock_irqsave(&wdev->event_lock, flags);
767 	}
768 	spin_unlock_irqrestore(&wdev->event_lock, flags);
769 }
770 
771 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
772 {
773 	struct wireless_dev *wdev;
774 
775 	ASSERT_RTNL();
776 	ASSERT_RDEV_LOCK(rdev);
777 
778 	mutex_lock(&rdev->devlist_mtx);
779 
780 	list_for_each_entry(wdev, &rdev->netdev_list, list)
781 		cfg80211_process_wdev_events(wdev);
782 
783 	mutex_unlock(&rdev->devlist_mtx);
784 }
785 
786 int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
787 			  struct net_device *dev, enum nl80211_iftype ntype,
788 			  u32 *flags, struct vif_params *params)
789 {
790 	int err;
791 	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
792 
793 	ASSERT_RDEV_LOCK(rdev);
794 
795 	/* don't support changing VLANs, you just re-create them */
796 	if (otype == NL80211_IFTYPE_AP_VLAN)
797 		return -EOPNOTSUPP;
798 
799 	if (!rdev->ops->change_virtual_intf ||
800 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
801 		return -EOPNOTSUPP;
802 
803 	/* if it's part of a bridge, reject changing type to station/ibss */
804 	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&
805 	    (ntype == NL80211_IFTYPE_ADHOC ||
806 	     ntype == NL80211_IFTYPE_STATION ||
807 	     ntype == NL80211_IFTYPE_P2P_CLIENT))
808 		return -EBUSY;
809 
810 	if (ntype != otype) {
811 		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
812 						    ntype);
813 		if (err)
814 			return err;
815 
816 		dev->ieee80211_ptr->use_4addr = false;
817 		dev->ieee80211_ptr->mesh_id_up_len = 0;
818 
819 		switch (otype) {
820 		case NL80211_IFTYPE_ADHOC:
821 			cfg80211_leave_ibss(rdev, dev, false);
822 			break;
823 		case NL80211_IFTYPE_STATION:
824 		case NL80211_IFTYPE_P2P_CLIENT:
825 			cfg80211_disconnect(rdev, dev,
826 					    WLAN_REASON_DEAUTH_LEAVING, true);
827 			break;
828 		case NL80211_IFTYPE_MESH_POINT:
829 			/* mesh should be handled? */
830 			break;
831 		default:
832 			break;
833 		}
834 
835 		cfg80211_process_rdev_events(rdev);
836 	}
837 
838 	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
839 					     ntype, flags, params);
840 
841 	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
842 
843 	if (!err && params && params->use_4addr != -1)
844 		dev->ieee80211_ptr->use_4addr = params->use_4addr;
845 
846 	if (!err) {
847 		dev->priv_flags &= ~IFF_DONT_BRIDGE;
848 		switch (ntype) {
849 		case NL80211_IFTYPE_STATION:
850 			if (dev->ieee80211_ptr->use_4addr)
851 				break;
852 			/* fall through */
853 		case NL80211_IFTYPE_P2P_CLIENT:
854 		case NL80211_IFTYPE_ADHOC:
855 			dev->priv_flags |= IFF_DONT_BRIDGE;
856 			break;
857 		case NL80211_IFTYPE_P2P_GO:
858 		case NL80211_IFTYPE_AP:
859 		case NL80211_IFTYPE_AP_VLAN:
860 		case NL80211_IFTYPE_WDS:
861 		case NL80211_IFTYPE_MESH_POINT:
862 			/* bridging OK */
863 			break;
864 		case NL80211_IFTYPE_MONITOR:
865 			/* monitor can't bridge anyway */
866 			break;
867 		case NL80211_IFTYPE_UNSPECIFIED:
868 		case NUM_NL80211_IFTYPES:
869 			/* not happening */
870 			break;
871 		}
872 	}
873 
874 	return err;
875 }
876 
877 u16 cfg80211_calculate_bitrate(struct rate_info *rate)
878 {
879 	int modulation, streams, bitrate;
880 
881 	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
882 		return rate->legacy;
883 
884 	/* the formula below does only work for MCS values smaller than 32 */
885 	if (rate->mcs >= 32)
886 		return 0;
887 
888 	modulation = rate->mcs & 7;
889 	streams = (rate->mcs >> 3) + 1;
890 
891 	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
892 			13500000 : 6500000;
893 
894 	if (modulation < 4)
895 		bitrate *= (modulation + 1);
896 	else if (modulation == 4)
897 		bitrate *= (modulation + 2);
898 	else
899 		bitrate *= (modulation + 3);
900 
901 	bitrate *= streams;
902 
903 	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
904 		bitrate = (bitrate / 9) * 10;
905 
906 	/* do NOT round down here */
907 	return (bitrate + 50000) / 100000;
908 }
909 
910 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
911 				 u32 beacon_int)
912 {
913 	struct wireless_dev *wdev;
914 	int res = 0;
915 
916 	if (!beacon_int)
917 		return -EINVAL;
918 
919 	mutex_lock(&rdev->devlist_mtx);
920 
921 	list_for_each_entry(wdev, &rdev->netdev_list, list) {
922 		if (!wdev->beacon_interval)
923 			continue;
924 		if (wdev->beacon_interval != beacon_int) {
925 			res = -EINVAL;
926 			break;
927 		}
928 	}
929 
930 	mutex_unlock(&rdev->devlist_mtx);
931 
932 	return res;
933 }
934 
935 int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
936 				  struct wireless_dev *wdev,
937 				  enum nl80211_iftype iftype)
938 {
939 	struct wireless_dev *wdev_iter;
940 	int num[NUM_NL80211_IFTYPES];
941 	int total = 1;
942 	int i, j;
943 
944 	ASSERT_RTNL();
945 
946 	/* Always allow software iftypes */
947 	if (rdev->wiphy.software_iftypes & BIT(iftype))
948 		return 0;
949 
950 	/*
951 	 * Drivers will gradually all set this flag, until all
952 	 * have it we only enforce for those that set it.
953 	 */
954 	if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS))
955 		return 0;
956 
957 	memset(num, 0, sizeof(num));
958 
959 	num[iftype] = 1;
960 
961 	mutex_lock(&rdev->devlist_mtx);
962 	list_for_each_entry(wdev_iter, &rdev->netdev_list, list) {
963 		if (wdev_iter == wdev)
964 			continue;
965 		if (!netif_running(wdev_iter->netdev))
966 			continue;
967 
968 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
969 			continue;
970 
971 		num[wdev_iter->iftype]++;
972 		total++;
973 	}
974 	mutex_unlock(&rdev->devlist_mtx);
975 
976 	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
977 		const struct ieee80211_iface_combination *c;
978 		struct ieee80211_iface_limit *limits;
979 
980 		c = &rdev->wiphy.iface_combinations[i];
981 
982 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
983 				 GFP_KERNEL);
984 		if (!limits)
985 			return -ENOMEM;
986 		if (total > c->max_interfaces)
987 			goto cont;
988 
989 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
990 			if (rdev->wiphy.software_iftypes & BIT(iftype))
991 				continue;
992 			for (j = 0; j < c->n_limits; j++) {
993 				if (!(limits[j].types & iftype))
994 					continue;
995 				if (limits[j].max < num[iftype])
996 					goto cont;
997 				limits[j].max -= num[iftype];
998 			}
999 		}
1000 		/* yay, it fits */
1001 		kfree(limits);
1002 		return 0;
1003  cont:
1004 		kfree(limits);
1005 	}
1006 
1007 	return -EBUSY;
1008 }
1009 
1010 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
1011 			   const u8 *rates, unsigned int n_rates,
1012 			   u32 *mask)
1013 {
1014 	int i, j;
1015 
1016 	if (!sband)
1017 		return -EINVAL;
1018 
1019 	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
1020 		return -EINVAL;
1021 
1022 	*mask = 0;
1023 
1024 	for (i = 0; i < n_rates; i++) {
1025 		int rate = (rates[i] & 0x7f) * 5;
1026 		bool found = false;
1027 
1028 		for (j = 0; j < sband->n_bitrates; j++) {
1029 			if (sband->bitrates[j].bitrate == rate) {
1030 				found = true;
1031 				*mask |= BIT(j);
1032 				break;
1033 			}
1034 		}
1035 		if (!found)
1036 			return -EINVAL;
1037 	}
1038 
1039 	/*
1040 	 * mask must have at least one bit set here since we
1041 	 * didn't accept a 0-length rates array nor allowed
1042 	 * entries in the array that didn't exist
1043 	 */
1044 
1045 	return 0;
1046 }
1047