xref: /linux/net/wireless/util.c (revision db4e83957f961f9053282409c5062c6baef857a4)
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 <linux/crc32.h>
11 #include <net/cfg80211.h>
12 #include <net/ip.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 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
244 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
245 const unsigned char rfc1042_header[] __aligned(2) =
246 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
247 EXPORT_SYMBOL(rfc1042_header);
248 
249 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
250 const unsigned char bridge_tunnel_header[] __aligned(2) =
251 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
252 EXPORT_SYMBOL(bridge_tunnel_header);
253 
254 unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
255 {
256 	unsigned int hdrlen = 24;
257 
258 	if (ieee80211_is_data(fc)) {
259 		if (ieee80211_has_a4(fc))
260 			hdrlen = 30;
261 		if (ieee80211_is_data_qos(fc)) {
262 			hdrlen += IEEE80211_QOS_CTL_LEN;
263 			if (ieee80211_has_order(fc))
264 				hdrlen += IEEE80211_HT_CTL_LEN;
265 		}
266 		goto out;
267 	}
268 
269 	if (ieee80211_is_ctl(fc)) {
270 		/*
271 		 * ACK and CTS are 10 bytes, all others 16. To see how
272 		 * to get this condition consider
273 		 *   subtype mask:   0b0000000011110000 (0x00F0)
274 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
275 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
276 		 *   bits that matter:         ^^^      (0x00E0)
277 		 *   value of those: 0b0000000011000000 (0x00C0)
278 		 */
279 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
280 			hdrlen = 10;
281 		else
282 			hdrlen = 16;
283 	}
284 out:
285 	return hdrlen;
286 }
287 EXPORT_SYMBOL(ieee80211_hdrlen);
288 
289 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
290 {
291 	const struct ieee80211_hdr *hdr =
292 			(const struct ieee80211_hdr *)skb->data;
293 	unsigned int hdrlen;
294 
295 	if (unlikely(skb->len < 10))
296 		return 0;
297 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
298 	if (unlikely(hdrlen > skb->len))
299 		return 0;
300 	return hdrlen;
301 }
302 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
303 
304 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
305 {
306 	int ae = meshhdr->flags & MESH_FLAGS_AE;
307 	/* 7.1.3.5a.2 */
308 	switch (ae) {
309 	case 0:
310 		return 6;
311 	case MESH_FLAGS_AE_A4:
312 		return 12;
313 	case MESH_FLAGS_AE_A5_A6:
314 		return 18;
315 	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
316 		return 24;
317 	default:
318 		return 6;
319 	}
320 }
321 
322 int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
323 			   enum nl80211_iftype iftype)
324 {
325 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
326 	u16 hdrlen, ethertype;
327 	u8 *payload;
328 	u8 dst[ETH_ALEN];
329 	u8 src[ETH_ALEN] __aligned(2);
330 
331 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
332 		return -1;
333 
334 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
335 
336 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
337 	 * header
338 	 * IEEE 802.11 address fields:
339 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
340 	 *   0     0   DA    SA    BSSID n/a
341 	 *   0     1   DA    BSSID SA    n/a
342 	 *   1     0   BSSID SA    DA    n/a
343 	 *   1     1   RA    TA    DA    SA
344 	 */
345 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
346 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
347 
348 	switch (hdr->frame_control &
349 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
350 	case cpu_to_le16(IEEE80211_FCTL_TODS):
351 		if (unlikely(iftype != NL80211_IFTYPE_AP &&
352 			     iftype != NL80211_IFTYPE_AP_VLAN &&
353 			     iftype != NL80211_IFTYPE_P2P_GO))
354 			return -1;
355 		break;
356 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
357 		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
358 			     iftype != NL80211_IFTYPE_MESH_POINT &&
359 			     iftype != NL80211_IFTYPE_AP_VLAN &&
360 			     iftype != NL80211_IFTYPE_STATION))
361 			return -1;
362 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
363 			struct ieee80211s_hdr *meshdr =
364 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
365 			/* make sure meshdr->flags is on the linear part */
366 			if (!pskb_may_pull(skb, hdrlen + 1))
367 				return -1;
368 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
369 				skb_copy_bits(skb, hdrlen +
370 					offsetof(struct ieee80211s_hdr, eaddr1),
371 				       	dst, ETH_ALEN);
372 				skb_copy_bits(skb, hdrlen +
373 					offsetof(struct ieee80211s_hdr, eaddr2),
374 				        src, ETH_ALEN);
375 			}
376 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
377 		}
378 		break;
379 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
380 		if ((iftype != NL80211_IFTYPE_STATION &&
381 		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
382 		     iftype != NL80211_IFTYPE_MESH_POINT) ||
383 		    (is_multicast_ether_addr(dst) &&
384 		     !compare_ether_addr(src, addr)))
385 			return -1;
386 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
387 			struct ieee80211s_hdr *meshdr =
388 				(struct ieee80211s_hdr *) (skb->data + hdrlen);
389 			/* make sure meshdr->flags is on the linear part */
390 			if (!pskb_may_pull(skb, hdrlen + 1))
391 				return -1;
392 			if (meshdr->flags & MESH_FLAGS_AE_A4)
393 				skb_copy_bits(skb, hdrlen +
394 					offsetof(struct ieee80211s_hdr, eaddr1),
395 					src, ETH_ALEN);
396 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
397 		}
398 		break;
399 	case cpu_to_le16(0):
400 		if (iftype != NL80211_IFTYPE_ADHOC &&
401 		    iftype != NL80211_IFTYPE_STATION)
402 				return -1;
403 		break;
404 	}
405 
406 	if (!pskb_may_pull(skb, hdrlen + 8))
407 		return -1;
408 
409 	payload = skb->data + hdrlen;
410 	ethertype = (payload[6] << 8) | payload[7];
411 
412 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
413 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
414 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
415 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
416 		 * replace EtherType */
417 		skb_pull(skb, hdrlen + 6);
418 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
419 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
420 	} else {
421 		struct ethhdr *ehdr;
422 		__be16 len;
423 
424 		skb_pull(skb, hdrlen);
425 		len = htons(skb->len);
426 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
427 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
428 		memcpy(ehdr->h_source, src, ETH_ALEN);
429 		ehdr->h_proto = len;
430 	}
431 	return 0;
432 }
433 EXPORT_SYMBOL(ieee80211_data_to_8023);
434 
435 int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,
436 			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
437 {
438 	struct ieee80211_hdr hdr;
439 	u16 hdrlen, ethertype;
440 	__le16 fc;
441 	const u8 *encaps_data;
442 	int encaps_len, skip_header_bytes;
443 	int nh_pos, h_pos;
444 	int head_need;
445 
446 	if (unlikely(skb->len < ETH_HLEN))
447 		return -EINVAL;
448 
449 	nh_pos = skb_network_header(skb) - skb->data;
450 	h_pos = skb_transport_header(skb) - skb->data;
451 
452 	/* convert Ethernet header to proper 802.11 header (based on
453 	 * operation mode) */
454 	ethertype = (skb->data[12] << 8) | skb->data[13];
455 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
456 
457 	switch (iftype) {
458 	case NL80211_IFTYPE_AP:
459 	case NL80211_IFTYPE_AP_VLAN:
460 	case NL80211_IFTYPE_P2P_GO:
461 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
462 		/* DA BSSID SA */
463 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
464 		memcpy(hdr.addr2, addr, ETH_ALEN);
465 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
466 		hdrlen = 24;
467 		break;
468 	case NL80211_IFTYPE_STATION:
469 	case NL80211_IFTYPE_P2P_CLIENT:
470 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
471 		/* BSSID SA DA */
472 		memcpy(hdr.addr1, bssid, ETH_ALEN);
473 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
474 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
475 		hdrlen = 24;
476 		break;
477 	case NL80211_IFTYPE_ADHOC:
478 		/* DA SA BSSID */
479 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
480 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
481 		memcpy(hdr.addr3, bssid, ETH_ALEN);
482 		hdrlen = 24;
483 		break;
484 	default:
485 		return -EOPNOTSUPP;
486 	}
487 
488 	if (qos) {
489 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
490 		hdrlen += 2;
491 	}
492 
493 	hdr.frame_control = fc;
494 	hdr.duration_id = 0;
495 	hdr.seq_ctrl = 0;
496 
497 	skip_header_bytes = ETH_HLEN;
498 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
499 		encaps_data = bridge_tunnel_header;
500 		encaps_len = sizeof(bridge_tunnel_header);
501 		skip_header_bytes -= 2;
502 	} else if (ethertype > 0x600) {
503 		encaps_data = rfc1042_header;
504 		encaps_len = sizeof(rfc1042_header);
505 		skip_header_bytes -= 2;
506 	} else {
507 		encaps_data = NULL;
508 		encaps_len = 0;
509 	}
510 
511 	skb_pull(skb, skip_header_bytes);
512 	nh_pos -= skip_header_bytes;
513 	h_pos -= skip_header_bytes;
514 
515 	head_need = hdrlen + encaps_len - skb_headroom(skb);
516 
517 	if (head_need > 0 || skb_cloned(skb)) {
518 		head_need = max(head_need, 0);
519 		if (head_need)
520 			skb_orphan(skb);
521 
522 		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC))
523 			return -ENOMEM;
524 
525 		skb->truesize += head_need;
526 	}
527 
528 	if (encaps_data) {
529 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
530 		nh_pos += encaps_len;
531 		h_pos += encaps_len;
532 	}
533 
534 	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
535 
536 	nh_pos += hdrlen;
537 	h_pos += hdrlen;
538 
539 	/* Update skb pointers to various headers since this modified frame
540 	 * is going to go through Linux networking code that may potentially
541 	 * need things like pointer to IP header. */
542 	skb_set_mac_header(skb, 0);
543 	skb_set_network_header(skb, nh_pos);
544 	skb_set_transport_header(skb, h_pos);
545 
546 	return 0;
547 }
548 EXPORT_SYMBOL(ieee80211_data_from_8023);
549 
550 
551 void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
552 			      const u8 *addr, enum nl80211_iftype iftype,
553 			      const unsigned int extra_headroom,
554 			      bool has_80211_header)
555 {
556 	struct sk_buff *frame = NULL;
557 	u16 ethertype;
558 	u8 *payload;
559 	const struct ethhdr *eth;
560 	int remaining, err;
561 	u8 dst[ETH_ALEN], src[ETH_ALEN];
562 
563 	if (has_80211_header) {
564 		err = ieee80211_data_to_8023(skb, addr, iftype);
565 		if (err)
566 			goto out;
567 
568 		/* skip the wrapping header */
569 		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
570 		if (!eth)
571 			goto out;
572 	} else {
573 		eth = (struct ethhdr *) skb->data;
574 	}
575 
576 	while (skb != frame) {
577 		u8 padding;
578 		__be16 len = eth->h_proto;
579 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
580 
581 		remaining = skb->len;
582 		memcpy(dst, eth->h_dest, ETH_ALEN);
583 		memcpy(src, eth->h_source, ETH_ALEN);
584 
585 		padding = (4 - subframe_len) & 0x3;
586 		/* the last MSDU has no padding */
587 		if (subframe_len > remaining)
588 			goto purge;
589 
590 		skb_pull(skb, sizeof(struct ethhdr));
591 		/* reuse skb for the last subframe */
592 		if (remaining <= subframe_len + padding)
593 			frame = skb;
594 		else {
595 			unsigned int hlen = ALIGN(extra_headroom, 4);
596 			/*
597 			 * Allocate and reserve two bytes more for payload
598 			 * alignment since sizeof(struct ethhdr) is 14.
599 			 */
600 			frame = dev_alloc_skb(hlen + subframe_len + 2);
601 			if (!frame)
602 				goto purge;
603 
604 			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
605 			memcpy(skb_put(frame, ntohs(len)), skb->data,
606 				ntohs(len));
607 
608 			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
609 							padding);
610 			if (!eth) {
611 				dev_kfree_skb(frame);
612 				goto purge;
613 			}
614 		}
615 
616 		skb_reset_network_header(frame);
617 		frame->dev = skb->dev;
618 		frame->priority = skb->priority;
619 
620 		payload = frame->data;
621 		ethertype = (payload[6] << 8) | payload[7];
622 
623 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
624 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
625 			   compare_ether_addr(payload,
626 					      bridge_tunnel_header) == 0)) {
627 			/* remove RFC1042 or Bridge-Tunnel
628 			 * encapsulation and replace EtherType */
629 			skb_pull(frame, 6);
630 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
631 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
632 		} else {
633 			memcpy(skb_push(frame, sizeof(__be16)), &len,
634 				sizeof(__be16));
635 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
636 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
637 		}
638 		__skb_queue_tail(list, frame);
639 	}
640 
641 	return;
642 
643  purge:
644 	__skb_queue_purge(list);
645  out:
646 	dev_kfree_skb(skb);
647 }
648 EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);
649 
650 /* Given a data frame determine the 802.1p/1d tag to use. */
651 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
652 {
653 	unsigned int dscp;
654 
655 	/* skb->priority values from 256->263 are magic values to
656 	 * directly indicate a specific 802.1d priority.  This is used
657 	 * to allow 802.1d priority to be passed directly in from VLAN
658 	 * tags, etc.
659 	 */
660 	if (skb->priority >= 256 && skb->priority <= 263)
661 		return skb->priority - 256;
662 
663 	switch (skb->protocol) {
664 	case htons(ETH_P_IP):
665 		dscp = ip_hdr(skb)->tos & 0xfc;
666 		break;
667 	default:
668 		return 0;
669 	}
670 
671 	return dscp >> 5;
672 }
673 EXPORT_SYMBOL(cfg80211_classify8021d);
674 
675 const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
676 {
677 	u8 *end, *pos;
678 
679 	pos = bss->information_elements;
680 	if (pos == NULL)
681 		return NULL;
682 	end = pos + bss->len_information_elements;
683 
684 	while (pos + 1 < end) {
685 		if (pos + 2 + pos[1] > end)
686 			break;
687 		if (pos[0] == ie)
688 			return pos;
689 		pos += 2 + pos[1];
690 	}
691 
692 	return NULL;
693 }
694 EXPORT_SYMBOL(ieee80211_bss_get_ie);
695 
696 void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
697 {
698 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
699 	struct net_device *dev = wdev->netdev;
700 	int i;
701 
702 	if (!wdev->connect_keys)
703 		return;
704 
705 	for (i = 0; i < 6; i++) {
706 		if (!wdev->connect_keys->params[i].cipher)
707 			continue;
708 		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,
709 					&wdev->connect_keys->params[i])) {
710 			netdev_err(dev, "failed to set key %d\n", i);
711 			continue;
712 		}
713 		if (wdev->connect_keys->def == i)
714 			if (rdev->ops->set_default_key(wdev->wiphy, dev,
715 						       i, true, true)) {
716 				netdev_err(dev, "failed to set defkey %d\n", i);
717 				continue;
718 			}
719 		if (wdev->connect_keys->defmgmt == i)
720 			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
721 				netdev_err(dev, "failed to set mgtdef %d\n", i);
722 	}
723 
724 	kfree(wdev->connect_keys);
725 	wdev->connect_keys = NULL;
726 }
727 
728 static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
729 {
730 	struct cfg80211_event *ev;
731 	unsigned long flags;
732 	const u8 *bssid = NULL;
733 
734 	spin_lock_irqsave(&wdev->event_lock, flags);
735 	while (!list_empty(&wdev->event_list)) {
736 		ev = list_first_entry(&wdev->event_list,
737 				      struct cfg80211_event, list);
738 		list_del(&ev->list);
739 		spin_unlock_irqrestore(&wdev->event_lock, flags);
740 
741 		wdev_lock(wdev);
742 		switch (ev->type) {
743 		case EVENT_CONNECT_RESULT:
744 			if (!is_zero_ether_addr(ev->cr.bssid))
745 				bssid = ev->cr.bssid;
746 			__cfg80211_connect_result(
747 				wdev->netdev, bssid,
748 				ev->cr.req_ie, ev->cr.req_ie_len,
749 				ev->cr.resp_ie, ev->cr.resp_ie_len,
750 				ev->cr.status,
751 				ev->cr.status == WLAN_STATUS_SUCCESS,
752 				NULL);
753 			break;
754 		case EVENT_ROAMED:
755 			__cfg80211_roamed(wdev, ev->rm.channel, ev->rm.bssid,
756 					  ev->rm.req_ie, ev->rm.req_ie_len,
757 					  ev->rm.resp_ie, ev->rm.resp_ie_len);
758 			break;
759 		case EVENT_DISCONNECTED:
760 			__cfg80211_disconnected(wdev->netdev,
761 						ev->dc.ie, ev->dc.ie_len,
762 						ev->dc.reason, true);
763 			break;
764 		case EVENT_IBSS_JOINED:
765 			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
766 			break;
767 		}
768 		wdev_unlock(wdev);
769 
770 		kfree(ev);
771 
772 		spin_lock_irqsave(&wdev->event_lock, flags);
773 	}
774 	spin_unlock_irqrestore(&wdev->event_lock, flags);
775 }
776 
777 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
778 {
779 	struct wireless_dev *wdev;
780 
781 	ASSERT_RTNL();
782 	ASSERT_RDEV_LOCK(rdev);
783 
784 	mutex_lock(&rdev->devlist_mtx);
785 
786 	list_for_each_entry(wdev, &rdev->netdev_list, list)
787 		cfg80211_process_wdev_events(wdev);
788 
789 	mutex_unlock(&rdev->devlist_mtx);
790 }
791 
792 int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
793 			  struct net_device *dev, enum nl80211_iftype ntype,
794 			  u32 *flags, struct vif_params *params)
795 {
796 	int err;
797 	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
798 
799 	ASSERT_RDEV_LOCK(rdev);
800 
801 	/* don't support changing VLANs, you just re-create them */
802 	if (otype == NL80211_IFTYPE_AP_VLAN)
803 		return -EOPNOTSUPP;
804 
805 	if (!rdev->ops->change_virtual_intf ||
806 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
807 		return -EOPNOTSUPP;
808 
809 	/* if it's part of a bridge, reject changing type to station/ibss */
810 	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&
811 	    (ntype == NL80211_IFTYPE_ADHOC ||
812 	     ntype == NL80211_IFTYPE_STATION ||
813 	     ntype == NL80211_IFTYPE_P2P_CLIENT))
814 		return -EBUSY;
815 
816 	if (ntype != otype) {
817 		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
818 						    ntype);
819 		if (err)
820 			return err;
821 
822 		dev->ieee80211_ptr->use_4addr = false;
823 		dev->ieee80211_ptr->mesh_id_up_len = 0;
824 
825 		switch (otype) {
826 		case NL80211_IFTYPE_ADHOC:
827 			cfg80211_leave_ibss(rdev, dev, false);
828 			break;
829 		case NL80211_IFTYPE_STATION:
830 		case NL80211_IFTYPE_P2P_CLIENT:
831 			cfg80211_disconnect(rdev, dev,
832 					    WLAN_REASON_DEAUTH_LEAVING, true);
833 			break;
834 		case NL80211_IFTYPE_MESH_POINT:
835 			/* mesh should be handled? */
836 			break;
837 		default:
838 			break;
839 		}
840 
841 		cfg80211_process_rdev_events(rdev);
842 	}
843 
844 	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
845 					     ntype, flags, params);
846 
847 	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
848 
849 	if (!err && params && params->use_4addr != -1)
850 		dev->ieee80211_ptr->use_4addr = params->use_4addr;
851 
852 	if (!err) {
853 		dev->priv_flags &= ~IFF_DONT_BRIDGE;
854 		switch (ntype) {
855 		case NL80211_IFTYPE_STATION:
856 			if (dev->ieee80211_ptr->use_4addr)
857 				break;
858 			/* fall through */
859 		case NL80211_IFTYPE_P2P_CLIENT:
860 		case NL80211_IFTYPE_ADHOC:
861 			dev->priv_flags |= IFF_DONT_BRIDGE;
862 			break;
863 		case NL80211_IFTYPE_P2P_GO:
864 		case NL80211_IFTYPE_AP:
865 		case NL80211_IFTYPE_AP_VLAN:
866 		case NL80211_IFTYPE_WDS:
867 		case NL80211_IFTYPE_MESH_POINT:
868 			/* bridging OK */
869 			break;
870 		case NL80211_IFTYPE_MONITOR:
871 			/* monitor can't bridge anyway */
872 			break;
873 		case NL80211_IFTYPE_UNSPECIFIED:
874 		case NUM_NL80211_IFTYPES:
875 			/* not happening */
876 			break;
877 		}
878 	}
879 
880 	return err;
881 }
882 
883 u16 cfg80211_calculate_bitrate(struct rate_info *rate)
884 {
885 	int modulation, streams, bitrate;
886 
887 	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
888 		return rate->legacy;
889 
890 	/* the formula below does only work for MCS values smaller than 32 */
891 	if (rate->mcs >= 32)
892 		return 0;
893 
894 	modulation = rate->mcs & 7;
895 	streams = (rate->mcs >> 3) + 1;
896 
897 	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
898 			13500000 : 6500000;
899 
900 	if (modulation < 4)
901 		bitrate *= (modulation + 1);
902 	else if (modulation == 4)
903 		bitrate *= (modulation + 2);
904 	else
905 		bitrate *= (modulation + 3);
906 
907 	bitrate *= streams;
908 
909 	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
910 		bitrate = (bitrate / 9) * 10;
911 
912 	/* do NOT round down here */
913 	return (bitrate + 50000) / 100000;
914 }
915 
916 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
917 				 u32 beacon_int)
918 {
919 	struct wireless_dev *wdev;
920 	int res = 0;
921 
922 	if (!beacon_int)
923 		return -EINVAL;
924 
925 	mutex_lock(&rdev->devlist_mtx);
926 
927 	list_for_each_entry(wdev, &rdev->netdev_list, list) {
928 		if (!wdev->beacon_interval)
929 			continue;
930 		if (wdev->beacon_interval != beacon_int) {
931 			res = -EINVAL;
932 			break;
933 		}
934 	}
935 
936 	mutex_unlock(&rdev->devlist_mtx);
937 
938 	return res;
939 }
940 
941 int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
942 				  struct wireless_dev *wdev,
943 				  enum nl80211_iftype iftype)
944 {
945 	struct wireless_dev *wdev_iter;
946 	int num[NUM_NL80211_IFTYPES];
947 	int total = 1;
948 	int i, j;
949 
950 	ASSERT_RTNL();
951 
952 	/* Always allow software iftypes */
953 	if (rdev->wiphy.software_iftypes & BIT(iftype))
954 		return 0;
955 
956 	/*
957 	 * Drivers will gradually all set this flag, until all
958 	 * have it we only enforce for those that set it.
959 	 */
960 	if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS))
961 		return 0;
962 
963 	memset(num, 0, sizeof(num));
964 
965 	num[iftype] = 1;
966 
967 	mutex_lock(&rdev->devlist_mtx);
968 	list_for_each_entry(wdev_iter, &rdev->netdev_list, list) {
969 		if (wdev_iter == wdev)
970 			continue;
971 		if (!netif_running(wdev_iter->netdev))
972 			continue;
973 
974 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
975 			continue;
976 
977 		num[wdev_iter->iftype]++;
978 		total++;
979 	}
980 	mutex_unlock(&rdev->devlist_mtx);
981 
982 	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
983 		const struct ieee80211_iface_combination *c;
984 		struct ieee80211_iface_limit *limits;
985 
986 		c = &rdev->wiphy.iface_combinations[i];
987 
988 		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
989 				 GFP_KERNEL);
990 		if (!limits)
991 			return -ENOMEM;
992 		if (total > c->max_interfaces)
993 			goto cont;
994 
995 		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
996 			if (rdev->wiphy.software_iftypes & BIT(iftype))
997 				continue;
998 			for (j = 0; j < c->n_limits; j++) {
999 				if (!(limits[j].types & iftype))
1000 					continue;
1001 				if (limits[j].max < num[iftype])
1002 					goto cont;
1003 				limits[j].max -= num[iftype];
1004 			}
1005 		}
1006 		/* yay, it fits */
1007 		kfree(limits);
1008 		return 0;
1009  cont:
1010 		kfree(limits);
1011 	}
1012 
1013 	return -EBUSY;
1014 }
1015 
1016 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
1017 			   const u8 *rates, unsigned int n_rates,
1018 			   u32 *mask)
1019 {
1020 	int i, j;
1021 
1022 	if (!sband)
1023 		return -EINVAL;
1024 
1025 	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
1026 		return -EINVAL;
1027 
1028 	*mask = 0;
1029 
1030 	for (i = 0; i < n_rates; i++) {
1031 		int rate = (rates[i] & 0x7f) * 5;
1032 		bool found = false;
1033 
1034 		for (j = 0; j < sband->n_bitrates; j++) {
1035 			if (sband->bitrates[j].bitrate == rate) {
1036 				found = true;
1037 				*mask |= BIT(j);
1038 				break;
1039 			}
1040 		}
1041 		if (!found)
1042 			return -EINVAL;
1043 	}
1044 
1045 	/*
1046 	 * mask must have at least one bit set here since we
1047 	 * didn't accept a 0-length rates array nor allowed
1048 	 * entries in the array that didn't exist
1049 	 */
1050 
1051 	return 0;
1052 }
1053 
1054 u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
1055 			       struct ieee802_11_elems *elems,
1056 			       u64 filter, u32 crc)
1057 {
1058 	size_t left = len;
1059 	u8 *pos = start;
1060 	bool calc_crc = filter != 0;
1061 
1062 	memset(elems, 0, sizeof(*elems));
1063 	elems->ie_start = start;
1064 	elems->total_len = len;
1065 
1066 	while (left >= 2) {
1067 		u8 id, elen;
1068 
1069 		id = *pos++;
1070 		elen = *pos++;
1071 		left -= 2;
1072 
1073 		if (elen > left)
1074 			break;
1075 
1076 		if (calc_crc && id < 64 && (filter & (1ULL << id)))
1077 			crc = crc32_be(crc, pos - 2, elen + 2);
1078 
1079 		switch (id) {
1080 		case WLAN_EID_SSID:
1081 			elems->ssid = pos;
1082 			elems->ssid_len = elen;
1083 			break;
1084 		case WLAN_EID_SUPP_RATES:
1085 			elems->supp_rates = pos;
1086 			elems->supp_rates_len = elen;
1087 			break;
1088 		case WLAN_EID_FH_PARAMS:
1089 			elems->fh_params = pos;
1090 			elems->fh_params_len = elen;
1091 			break;
1092 		case WLAN_EID_DS_PARAMS:
1093 			elems->ds_params = pos;
1094 			elems->ds_params_len = elen;
1095 			break;
1096 		case WLAN_EID_CF_PARAMS:
1097 			elems->cf_params = pos;
1098 			elems->cf_params_len = elen;
1099 			break;
1100 		case WLAN_EID_TIM:
1101 			if (elen >= sizeof(struct ieee80211_tim_ie)) {
1102 				elems->tim = (void *)pos;
1103 				elems->tim_len = elen;
1104 			}
1105 			break;
1106 		case WLAN_EID_IBSS_PARAMS:
1107 			elems->ibss_params = pos;
1108 			elems->ibss_params_len = elen;
1109 			break;
1110 		case WLAN_EID_CHALLENGE:
1111 			elems->challenge = pos;
1112 			elems->challenge_len = elen;
1113 			break;
1114 		case WLAN_EID_VENDOR_SPECIFIC:
1115 			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
1116 			    pos[2] == 0xf2) {
1117 				/* Microsoft OUI (00:50:F2) */
1118 
1119 				if (calc_crc)
1120 					crc = crc32_be(crc, pos - 2, elen + 2);
1121 
1122 				if (pos[3] == 1) {
1123 					/* OUI Type 1 - WPA IE */
1124 					elems->wpa = pos;
1125 					elems->wpa_len = elen;
1126 				} else if (elen >= 5 && pos[3] == 2) {
1127 					/* OUI Type 2 - WMM IE */
1128 					if (pos[4] == 0) {
1129 						elems->wmm_info = pos;
1130 						elems->wmm_info_len = elen;
1131 					} else if (pos[4] == 1) {
1132 						elems->wmm_param = pos;
1133 						elems->wmm_param_len = elen;
1134 					}
1135 				}
1136 			}
1137 			break;
1138 		case WLAN_EID_RSN:
1139 			elems->rsn = pos;
1140 			elems->rsn_len = elen;
1141 			break;
1142 		case WLAN_EID_ERP_INFO:
1143 			elems->erp_info = pos;
1144 			elems->erp_info_len = elen;
1145 			break;
1146 		case WLAN_EID_EXT_SUPP_RATES:
1147 			elems->ext_supp_rates = pos;
1148 			elems->ext_supp_rates_len = elen;
1149 			break;
1150 		case WLAN_EID_HT_CAPABILITY:
1151 			if (elen >= sizeof(struct ieee80211_ht_cap))
1152 				elems->ht_cap_elem = (void *)pos;
1153 			break;
1154 		case WLAN_EID_HT_INFORMATION:
1155 			if (elen >= sizeof(struct ieee80211_ht_info))
1156 				elems->ht_info_elem = (void *)pos;
1157 			break;
1158 		case WLAN_EID_MESH_ID:
1159 			elems->mesh_id = pos;
1160 			elems->mesh_id_len = elen;
1161 			break;
1162 		case WLAN_EID_MESH_CONFIG:
1163 			if (elen >= sizeof(struct ieee80211_meshconf_ie))
1164 				elems->mesh_config = (void *)pos;
1165 			break;
1166 		case WLAN_EID_PEER_MGMT:
1167 			elems->peering = pos;
1168 			elems->peering_len = elen;
1169 			break;
1170 		case WLAN_EID_PREQ:
1171 			elems->preq = pos;
1172 			elems->preq_len = elen;
1173 			break;
1174 		case WLAN_EID_PREP:
1175 			elems->prep = pos;
1176 			elems->prep_len = elen;
1177 			break;
1178 		case WLAN_EID_PERR:
1179 			elems->perr = pos;
1180 			elems->perr_len = elen;
1181 			break;
1182 		case WLAN_EID_RANN:
1183 			if (elen >= sizeof(struct ieee80211_rann_ie))
1184 				elems->rann = (void *)pos;
1185 			break;
1186 		case WLAN_EID_CHANNEL_SWITCH:
1187 			elems->ch_switch_elem = pos;
1188 			elems->ch_switch_elem_len = elen;
1189 			break;
1190 		case WLAN_EID_QUIET:
1191 			if (!elems->quiet_elem) {
1192 				elems->quiet_elem = pos;
1193 				elems->quiet_elem_len = elen;
1194 			}
1195 			elems->num_of_quiet_elem++;
1196 			break;
1197 		case WLAN_EID_COUNTRY:
1198 			elems->country_elem = pos;
1199 			elems->country_elem_len = elen;
1200 			break;
1201 		case WLAN_EID_PWR_CONSTRAINT:
1202 			elems->pwr_constr_elem = pos;
1203 			elems->pwr_constr_elem_len = elen;
1204 			break;
1205 		case WLAN_EID_TIMEOUT_INTERVAL:
1206 			elems->timeout_int = pos;
1207 			elems->timeout_int_len = elen;
1208 			break;
1209 		default:
1210 			break;
1211 		}
1212 
1213 		left -= elen;
1214 		pos += elen;
1215 	}
1216 
1217 	return crc;
1218 }
1219 EXPORT_SYMBOL(ieee802_11_parse_elems_crc);
1220