summaryrefslogtreecommitdiffstats
path: root/net/wireless/util.c
blob: 693275a16a26b504061647e206443db5eaffed44 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/*
 * Wireless utility functions
 *
 * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>
 */
#include <linux/bitops.h>
#include <linux/etherdevice.h>
#include <net/cfg80211.h>
#include <net/ip.h>
#include "core.h"

struct ieee80211_rate *
ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
			    u32 basic_rates, int bitrate)
{
	struct ieee80211_rate *result = &sband->bitrates[0];
	int i;

	for (i = 0; i < sband->n_bitrates; i++) {
		if (!(basic_rates & BIT(i)))
			continue;
		if (sband->bitrates[i].bitrate > bitrate)
			continue;
		result = &sband->bitrates[i];
	}

	return result;
}
EXPORT_SYMBOL(ieee80211_get_response_rate);

int ieee80211_channel_to_frequency(int chan)
{
	if (chan < 14)
		return 2407 + chan * 5;

	if (chan == 14)
		return 2484;

	/* FIXME: 802.11j 17.3.8.3.2 */
	return (chan + 1000) * 5;
}
EXPORT_SYMBOL(ieee80211_channel_to_frequency);

int ieee80211_frequency_to_channel(int freq)
{
	if (freq == 2484)
		return 14;

	if (freq < 2484)
		return (freq - 2407) / 5;

	/* FIXME: 802.11j 17.3.8.3.2 */
	return freq/5 - 1000;
}
EXPORT_SYMBOL(ieee80211_frequency_to_channel);

struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
						  int freq)
{
	enum ieee80211_band band;
	struct ieee80211_supported_band *sband;
	int i;

	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		sband = wiphy->bands[band];

		if (!sband)
			continue;

		for (i = 0; i < sband->n_channels; i++) {
			if (sband->channels[i].center_freq == freq)
				return &sband->channels[i];
		}
	}

	return NULL;
}
EXPORT_SYMBOL(__ieee80211_get_channel);

static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
				     enum ieee80211_band band)
{
	int i, want;

	switch (band) {
	case IEEE80211_BAND_5GHZ:
		want = 3;
		for (i = 0; i < sband->n_bitrates; i++) {
			if (sband->bitrates[i].bitrate == 60 ||
			    sband->bitrates[i].bitrate == 120 ||
			    sband->bitrates[i].bitrate == 240) {
				sband->bitrates[i].flags |=
					IEEE80211_RATE_MANDATORY_A;
				want--;
			}
		}
		WARN_ON(want);
		break;
	case IEEE80211_BAND_2GHZ:
		want = 7;
		for (i = 0; i < sband->n_bitrates; i++) {
			if (sband->bitrates[i].bitrate == 10) {
				sband->bitrates[i].flags |=
					IEEE80211_RATE_MANDATORY_B |
					IEEE80211_RATE_MANDATORY_G;
				want--;
			}

			if (sband->bitrates[i].bitrate == 20 ||
			    sband->bitrates[i].bitrate == 55 ||
			    sband->bitrates[i].bitrate == 110 ||
			    sband->bitrates[i].bitrate == 60 ||
			    sband->bitrates[i].bitrate == 120 ||
			    sband->bitrates[i].bitrate == 240) {
				sband->bitrates[i].flags |=
					IEEE80211_RATE_MANDATORY_G;
				want--;
			}

			if (sband->bitrates[i].bitrate != 10 &&
			    sband->bitrates[i].bitrate != 20 &&
			    sband->bitrates[i].bitrate != 55 &&
			    sband->bitrates[i].bitrate != 110)
				sband->bitrates[i].flags |=
					IEEE80211_RATE_ERP_G;
		}
		WARN_ON(want != 0 && want != 3 && want != 6);
		break;
	case IEEE80211_NUM_BANDS:
		WARN_ON(1);
		break;
	}
}

void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
{
	enum ieee80211_band band;

	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
		if (wiphy->bands[band])
			set_mandatory_flags_band(wiphy->bands[band], band);
}

int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
				   struct key_params *params, int key_idx,
				   const u8 *mac_addr)
{
	int i;

	if (key_idx > 5)
		return -EINVAL;

	/*
	 * Disallow pairwise keys with non-zero index unless it's WEP
	 * (because current deployments use pairwise WEP keys with
	 * non-zero indizes but 802.11i clearly specifies to use zero)
	 */
	if (mac_addr && key_idx &&
	    params->cipher != WLAN_CIPHER_SUITE_WEP40 &&
	    params->cipher != WLAN_CIPHER_SUITE_WEP104)
		return -EINVAL;

	switch (params->cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
		if (params->key_len != WLAN_KEY_LEN_WEP40)
			return -EINVAL;
		break;
	case WLAN_CIPHER_SUITE_TKIP:
		if (params->key_len != WLAN_KEY_LEN_TKIP)
			return -EINVAL;
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		if (params->key_len != WLAN_KEY_LEN_CCMP)
			return -EINVAL;
		break;
	case WLAN_CIPHER_SUITE_WEP104:
		if (params->key_len != WLAN_KEY_LEN_WEP104)
			return -EINVAL;
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	if (params->seq) {
		switch (params->cipher) {
		case WLAN_CIPHER_SUITE_WEP40:
		case WLAN_CIPHER_SUITE_WEP104:
			/* These ciphers do not use key sequence */
			return -EINVAL;
		case WLAN_CIPHER_SUITE_TKIP:
		case WLAN_CIPHER_SUITE_CCMP:
		case WLAN_CIPHER_SUITE_AES_CMAC:
			if (params->seq_len != 6)
				return -EINVAL;
			break;
		}
	}

	for (i = 0; i < rdev->wiphy.n_cipher_suites; i++)
		if (params->cipher == rdev->wiphy.cipher_suites[i])
			break;
	if (i == rdev->wiphy.n_cipher_suites)
		return -EINVAL;

	return 0;
}

/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
EXPORT_SYMBOL(rfc1042_header);

/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
const unsigned char bridge_tunnel_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
EXPORT_SYMBOL(bridge_tunnel_header);

unsigned int ieee80211_hdrlen(__le16 fc)
{
	unsigned int hdrlen = 24;

	if (ieee80211_is_data(fc)) {
		if (ieee80211_has_a4(fc))
			hdrlen = 30;
		if (ieee80211_is_data_qos(fc))
			hdrlen += IEEE80211_QOS_CTL_LEN;
		goto out;
	}

	if (ieee80211_is_ctl(fc)) {
		/*
		 * ACK and CTS are 10 bytes, all others 16. To see how
		 * to get this condition consider
		 *   subtype mask:   0b0000000011110000 (0x00F0)
		 *   ACK subtype:    0b0000000011010000 (0x00D0)
		 *   CTS subtype:    0b0000000011000000 (0x00C0)
		 *   bits that matter:         ^^^      (0x00E0)
		 *   value of those: 0b0000000011000000 (0x00C0)
		 */
		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
			hdrlen = 10;
		else
			hdrlen = 16;
	}
out:
	return hdrlen;
}
EXPORT_SYMBOL(ieee80211_hdrlen);

unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
	const struct ieee80211_hdr *hdr =
			(const struct ieee80211_hdr *)skb->data;
	unsigned int hdrlen;

	if (unlikely(skb->len < 10))
		return 0;
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	if (unlikely(hdrlen > skb->len))
		return 0;
	return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
{
	int ae = meshhdr->flags & MESH_FLAGS_AE;
	/* 7.1.3.5a.2 */
	switch (ae) {
	case 0:
		return 6;
	case MESH_FLAGS_AE_A4:
		return 12;
	case MESH_FLAGS_AE_A5_A6:
		return 18;
	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
		return 24;
	default:
		return 6;
	}
}

int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
			   enum nl80211_iftype iftype)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 hdrlen, ethertype;
	u8 *payload;
	u8 dst[ETH_ALEN];
	u8 src[ETH_ALEN] __aligned(2);

	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
		return -1;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);

	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
	 * header
	 * IEEE 802.11 address fields:
	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
	 *   0     0   DA    SA    BSSID n/a
	 *   0     1   DA    BSSID SA    n/a
	 *   1     0   BSSID SA    DA    n/a
	 *   1     1   RA    TA    DA    SA
	 */
	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);

	switch (hdr->frame_control &
		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
	case cpu_to_le16(IEEE80211_FCTL_TODS):
		if (unlikely(iftype != NL80211_IFTYPE_AP &&
			     iftype != NL80211_IFTYPE_AP_VLAN))
			return -1;
		break;
	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
		if (unlikely(iftype != NL80211_IFTYPE_WDS &&
			     iftype != NL80211_IFTYPE_MESH_POINT))
			return -1;
		if (iftype == NL80211_IFTYPE_MESH_POINT) {
			struct ieee80211s_hdr *meshdr =
				(struct ieee80211s_hdr *) (skb->data + hdrlen);
			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
				memcpy(dst, meshdr->eaddr1, ETH_ALEN);
				memcpy(src, meshdr->eaddr2, ETH_ALEN);
			}
		}
		break;
	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
		if ((iftype != NL80211_IFTYPE_STATION &&
		    iftype != NL80211_IFTYPE_MESH_POINT) ||
		    (is_multicast_ether_addr(dst) &&
		     !compare_ether_addr(src, addr)))
			return -1;
		if (iftype == NL80211_IFTYPE_MESH_POINT) {
			struct ieee80211s_hdr *meshdr =
				(struct ieee80211s_hdr *) (skb->data + hdrlen);
			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
			if (meshdr->flags & MESH_FLAGS_AE_A4)
				memcpy(src, meshdr->eaddr1, ETH_ALEN);
		}
		break;
	case cpu_to_le16(0):
		if (iftype != NL80211_IFTYPE_ADHOC)
			return -1;
		break;
	}

	if (unlikely(skb->len - hdrlen < 8))
		return -1;

	payload = skb->data + hdrlen;
	ethertype = (payload[6] << 8) | payload[7];

	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
		/* remove RFC1042 or Bridge-Tunnel encapsulation and
		 * replace EtherType */
		skb_pull(skb, hdrlen + 6);
		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
	} else {
		struct ethhdr *ehdr;
		__be16 len;

		skb_pull(skb, hdrlen);
		len = htons(skb->len);
		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
		memcpy(ehdr->h_dest, dst, ETH_ALEN);
		memcpy(ehdr->h_source, src, ETH_ALEN);
		ehdr->h_proto = len;
	}
	return 0;
}
EXPORT_SYMBOL(ieee80211_data_to_8023);

int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
{
	struct ieee80211_hdr hdr;
	u16 hdrlen, ethertype;
	__le16 fc;
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
	int nh_pos, h_pos;
	int head_need;

	if (unlikely(skb->len < ETH_HLEN))
		return -EINVAL;

	nh_pos = skb_network_header(skb) - skb->data;
	h_pos = skb_transport_header(skb) - skb->data;

	/* convert Ethernet header to proper 802.11 header (based on
	 * operation mode) */
	ethertype = (skb->data[12] << 8) | skb->data[13];
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);

	switch (iftype) {
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
		/* DA BSSID SA */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 24;
		break;
	case NL80211_IFTYPE_STATION:
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
		/* BSSID SA DA */
		memcpy(hdr.addr1, bssid, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
		break;
	case NL80211_IFTYPE_ADHOC:
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, bssid, ETH_ALEN);
		hdrlen = 24;
		break;
	default:
		return -EOPNOTSUPP;
	}

	if (qos) {
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
		hdrlen += 2;
	}

	hdr.frame_control = fc;
	hdr.duration_id = 0;
	hdr.seq_ctrl = 0;

	skip_header_bytes = ETH_HLEN;
	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
		encaps_data = bridge_tunnel_header;
		encaps_len = sizeof(bridge_tunnel_header);
		skip_header_bytes -= 2;
	} else if (ethertype > 0x600) {
		encaps_data = rfc1042_header;
		encaps_len = sizeof(rfc1042_header);
		skip_header_bytes -= 2;
	} else {
		encaps_data = NULL;
		encaps_len = 0;
	}

	skb_pull(skb, skip_header_bytes);
	nh_pos -= skip_header_bytes;
	h_pos -= skip_header_bytes;

	head_need = hdrlen + encaps_len - skb_headroom(skb);

	if (head_need > 0 || skb_cloned(skb)) {
		head_need = max(head_need, 0);
		if (head_need)
			skb_orphan(skb);

		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) {
			printk(KERN_ERR "failed to reallocate Tx buffer\n");
			return -ENOMEM;
		}
		skb->truesize += head_need;
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}

	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);

	nh_pos += hdrlen;
	h_pos += hdrlen;

	/* Update skb pointers to various headers since this modified frame
	 * is going to go through Linux networking code that may potentially
	 * need things like pointer to IP header. */
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, nh_pos);
	skb_set_transport_header(skb, h_pos);

	return 0;
}
EXPORT_SYMBOL(ieee80211_data_from_8023);

/* Given a data frame determine the 802.1p/1d tag to use. */
unsigned int cfg80211_classify8021d(struct sk_buff *skb)
{
	unsigned int dscp;

	/* skb->priority values from 256->263 are magic values to
	 * directly indicate a specific 802.1d priority.  This is used
	 * to allow 802.1d priority to be passed directly in from VLAN
	 * tags, etc.
	 */
	if (skb->priority >= 256 && skb->priority <= 263)
		return skb->priority - 256;

	switch (skb->protocol) {
	case htons(ETH_P_IP):
		dscp = ip_hdr(skb)->tos & 0xfc;
		break;
	default:
		return 0;
	}

	return dscp >> 5;
}
EXPORT_SYMBOL(cfg80211_classify8021d);

const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
{
	u8 *end, *pos;

	pos = bss->information_elements;
	if (pos == NULL)
		return NULL;
	end = pos + bss->len_information_elements;

	while (pos + 1 < end) {
		if (pos + 2 + pos[1] > end)
			break;
		if (pos[0] == ie)
			return pos;
		pos += 2 + pos[1];
	}

	return NULL;
}
EXPORT_SYMBOL(ieee80211_bss_get_ie);

void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
{
	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
	struct net_device *dev = wdev->netdev;
	int i;

	if (!wdev->connect_keys)
		return;

	for (i = 0; i < 6; i++) {
		if (!wdev->connect_keys->params[i].cipher)
			continue;
		if (rdev->ops->add_key(wdev->wiphy, dev, i, NULL,
					&wdev->connect_keys->params[i])) {
			printk(KERN_ERR "%s: failed to set key %d\n",
				dev->name, i);
			continue;
		}
		if (wdev->connect_keys->def == i)
			if (rdev->ops->set_default_key(wdev->wiphy, dev, i)) {
				printk(KERN_ERR "%s: failed to set defkey %d\n",
					dev->name, i);
				continue;
			}
		if (wdev->connect_keys->defmgmt == i)
			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
				printk(KERN_ERR "%s: failed to set mgtdef %d\n",
					dev->name, i);
	}

	kfree(wdev->connect_keys);
	wdev->connect_keys = NULL;
}
OpenPOWER on IntegriCloud