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printk removal, receive reordering bugfix
[cor_2_6_31.git] / net / wireless / util.c
blob25550692dda6b7a4112adebfa28d2666666c79d3
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 <net/cfg80211.h>
9 #include <net/ip.h>
10 #include "core.h"
11
12 struct ieee80211_rate *
13 ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
14 u32 basic_rates, int bitrate)
15 {
16 struct ieee80211_rate *result = &sband->bitrates[0];
17 int i;
18
19 for (i = 0; i < sband->n_bitrates; i++) {
20 if (!(basic_rates & BIT(i)))
21 continue;
22 if (sband->bitrates[i].bitrate > bitrate)
23 continue;
24 result = &sband->bitrates[i];
25 }
26
27 return result;
28 }
29 EXPORT_SYMBOL(ieee80211_get_response_rate);
30
31 int ieee80211_channel_to_frequency(int chan)
32 {
33 if (chan < 14)
34 return 2407 + chan * 5;
35
36 if (chan == 14)
37 return 2484;
38
39 /* FIXME: 802.11j 17.3.8.3.2 */
40 return (chan + 1000) * 5;
41 }
42 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
43
44 int ieee80211_frequency_to_channel(int freq)
45 {
46 if (freq == 2484)
47 return 14;
48
49 if (freq < 2484)
50 return (freq - 2407) / 5;
51
52 /* FIXME: 802.11j 17.3.8.3.2 */
53 return freq/5 - 1000;
54 }
55 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
56
57 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
58 int freq)
59 {
60 enum ieee80211_band band;
61 struct ieee80211_supported_band *sband;
62 int i;
63
64 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
65 sband = wiphy->bands[band];
66
67 if (!sband)
68 continue;
69
70 for (i = 0; i < sband->n_channels; i++) {
71 if (sband->channels[i].center_freq == freq)
72 return &sband->channels[i];
73 }
74 }
75
76 return NULL;
77 }
78 EXPORT_SYMBOL(__ieee80211_get_channel);
79
80 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
81 enum ieee80211_band band)
82 {
83 int i, want;
84
85 switch (band) {
86 case IEEE80211_BAND_5GHZ:
87 want = 3;
88 for (i = 0; i < sband->n_bitrates; i++) {
89 if (sband->bitrates[i].bitrate == 60 ||
90 sband->bitrates[i].bitrate == 120 ||
91 sband->bitrates[i].bitrate == 240) {
92 sband->bitrates[i].flags |=
93 IEEE80211_RATE_MANDATORY_A;
94 want--;
95 }
96 }
97 WARN_ON(want);
98 break;
99 case IEEE80211_BAND_2GHZ:
100 want = 7;
101 for (i = 0; i < sband->n_bitrates; i++) {
102 if (sband->bitrates[i].bitrate == 10) {
103 sband->bitrates[i].flags |=
104 IEEE80211_RATE_MANDATORY_B |
105 IEEE80211_RATE_MANDATORY_G;
106 want--;
107 }
108
109 if (sband->bitrates[i].bitrate == 20 ||
110 sband->bitrates[i].bitrate == 55 ||
111 sband->bitrates[i].bitrate == 110 ||
112 sband->bitrates[i].bitrate == 60 ||
113 sband->bitrates[i].bitrate == 120 ||
114 sband->bitrates[i].bitrate == 240) {
115 sband->bitrates[i].flags |=
116 IEEE80211_RATE_MANDATORY_G;
117 want--;
118 }
119
120 if (sband->bitrates[i].bitrate != 10 &&
121 sband->bitrates[i].bitrate != 20 &&
122 sband->bitrates[i].bitrate != 55 &&
123 sband->bitrates[i].bitrate != 110)
124 sband->bitrates[i].flags |=
125 IEEE80211_RATE_ERP_G;
126 }
127 WARN_ON(want != 0 && want != 3 && want != 6);
128 break;
129 case IEEE80211_NUM_BANDS:
130 WARN_ON(1);
131 break;
132 }
133 }
134
135 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
136 {
137 enum ieee80211_band band;
138
139 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
140 if (wiphy->bands[band])
141 set_mandatory_flags_band(wiphy->bands[band], band);
142 }
143
144 int cfg80211_validate_key_settings(struct key_params *params, int key_idx,
145 const u8 *mac_addr)
146 {
147 if (key_idx > 5)
148 return -EINVAL;
149
150 /*
151 * Disallow pairwise keys with non-zero index unless it's WEP
152 * (because current deployments use pairwise WEP keys with
153 * non-zero indizes but 802.11i clearly specifies to use zero)
154 */
155 if (mac_addr && key_idx &&
156 params->cipher != WLAN_CIPHER_SUITE_WEP40 &&
157 params->cipher != WLAN_CIPHER_SUITE_WEP104)
158 return -EINVAL;
159
160 switch (params->cipher) {
161 case WLAN_CIPHER_SUITE_WEP40:
162 if (params->key_len != WLAN_KEY_LEN_WEP40)
163 return -EINVAL;
164 break;
165 case WLAN_CIPHER_SUITE_TKIP:
166 if (params->key_len != WLAN_KEY_LEN_TKIP)
167 return -EINVAL;
168 break;
169 case WLAN_CIPHER_SUITE_CCMP:
170 if (params->key_len != WLAN_KEY_LEN_CCMP)
171 return -EINVAL;
172 break;
173 case WLAN_CIPHER_SUITE_WEP104:
174 if (params->key_len != WLAN_KEY_LEN_WEP104)
175 return -EINVAL;
176 break;
177 case WLAN_CIPHER_SUITE_AES_CMAC:
178 if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
179 return -EINVAL;
180 break;
181 default:
182 return -EINVAL;
183 }
184
185 if (params->seq) {
186 switch (params->cipher) {
187 case WLAN_CIPHER_SUITE_WEP40:
188 case WLAN_CIPHER_SUITE_WEP104:
189 /* These ciphers do not use key sequence */
190 return -EINVAL;
191 case WLAN_CIPHER_SUITE_TKIP:
192 case WLAN_CIPHER_SUITE_CCMP:
193 case WLAN_CIPHER_SUITE_AES_CMAC:
194 if (params->seq_len != 6)
195 return -EINVAL;
196 break;
197 }
198 }
199
200 return 0;
201 }
202
203 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
204 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
205 const unsigned char rfc1042_header[] __aligned(2) =
206 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
207 EXPORT_SYMBOL(rfc1042_header);
208
209 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
210 const unsigned char bridge_tunnel_header[] __aligned(2) =
211 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
212 EXPORT_SYMBOL(bridge_tunnel_header);
213
214 unsigned int ieee80211_hdrlen(__le16 fc)
215 {
216 unsigned int hdrlen = 24;
217
218 if (ieee80211_is_data(fc)) {
219 if (ieee80211_has_a4(fc))
220 hdrlen = 30;
221 if (ieee80211_is_data_qos(fc))
222 hdrlen += IEEE80211_QOS_CTL_LEN;
223 goto out;
224 }
225
226 if (ieee80211_is_ctl(fc)) {
227 /*
228 * ACK and CTS are 10 bytes, all others 16. To see how
229 * to get this condition consider
230 * subtype mask: 0b0000000011110000 (0x00F0)
231 * ACK subtype: 0b0000000011010000 (0x00D0)
232 * CTS subtype: 0b0000000011000000 (0x00C0)
233 * bits that matter: ^^^ (0x00E0)
234 * value of those: 0b0000000011000000 (0x00C0)
235 */
236 if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
237 hdrlen = 10;
238 else
239 hdrlen = 16;
240 }
241 out:
242 return hdrlen;
243 }
244 EXPORT_SYMBOL(ieee80211_hdrlen);
245
246 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
247 {
248 const struct ieee80211_hdr *hdr =
249 (const struct ieee80211_hdr *)skb->data;
250 unsigned int hdrlen;
251
252 if (unlikely(skb->len < 10))
253 return 0;
254 hdrlen = ieee80211_hdrlen(hdr->frame_control);
255 if (unlikely(hdrlen > skb->len))
256 return 0;
257 return hdrlen;
258 }
259 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
260
261 static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
262 {
263 int ae = meshhdr->flags & MESH_FLAGS_AE;
264 /* 7.1.3.5a.2 */
265 switch (ae) {
266 case 0:
267 return 6;
268 case 1:
269 return 12;
270 case 2:
271 return 18;
272 case 3:
273 return 24;
274 default:
275 return 6;
276 }
277 }
278
279 int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
280 enum nl80211_iftype iftype)
281 {
282 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
283 u16 hdrlen, ethertype;
284 u8 *payload;
285 u8 dst[ETH_ALEN];
286 u8 src[ETH_ALEN] __aligned(2);
287
288 if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
289 return -1;
290
291 hdrlen = ieee80211_hdrlen(hdr->frame_control);
292
293 /* convert IEEE 802.11 header + possible LLC headers into Ethernet
294 * header
295 * IEEE 802.11 address fields:
296 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
297 * 0 0 DA SA BSSID n/a
298 * 0 1 DA BSSID SA n/a
299 * 1 0 BSSID SA DA n/a
300 * 1 1 RA TA DA SA
301 */
302 memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
303 memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
304
305 switch (hdr->frame_control &
306 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
307 case cpu_to_le16(IEEE80211_FCTL_TODS):
308 if (unlikely(iftype != NL80211_IFTYPE_AP &&
309 iftype != NL80211_IFTYPE_AP_VLAN))
310 return -1;
311 break;
312 case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
313 if (unlikely(iftype != NL80211_IFTYPE_WDS &&
314 iftype != NL80211_IFTYPE_MESH_POINT))
315 return -1;
316 if (iftype == NL80211_IFTYPE_MESH_POINT) {
317 struct ieee80211s_hdr *meshdr =
318 (struct ieee80211s_hdr *) (skb->data + hdrlen);
319 hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
320 if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
321 memcpy(dst, meshdr->eaddr1, ETH_ALEN);
322 memcpy(src, meshdr->eaddr2, ETH_ALEN);
323 }
324 }
325 break;
326 case cpu_to_le16(IEEE80211_FCTL_FROMDS):
327 if (iftype != NL80211_IFTYPE_STATION ||
328 (is_multicast_ether_addr(dst) &&
329 !compare_ether_addr(src, addr)))
330 return -1;
331 break;
332 case cpu_to_le16(0):
333 if (iftype != NL80211_IFTYPE_ADHOC)
334 return -1;
335 break;
336 }
337
338 if (unlikely(skb->len - hdrlen < 8))
339 return -1;
340
341 payload = skb->data + hdrlen;
342 ethertype = (payload[6] << 8) | payload[7];
343
344 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
345 ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
346 compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
347 /* remove RFC1042 or Bridge-Tunnel encapsulation and
348 * replace EtherType */
349 skb_pull(skb, hdrlen + 6);
350 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
351 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
352 } else {
353 struct ethhdr *ehdr;
354 __be16 len;
355
356 skb_pull(skb, hdrlen);
357 len = htons(skb->len);
358 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
359 memcpy(ehdr->h_dest, dst, ETH_ALEN);
360 memcpy(ehdr->h_source, src, ETH_ALEN);
361 ehdr->h_proto = len;
362 }
363 return 0;
364 }
365 EXPORT_SYMBOL(ieee80211_data_to_8023);
366
367 int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
368 enum nl80211_iftype iftype, u8 *bssid, bool qos)
369 {
370 struct ieee80211_hdr hdr;
371 u16 hdrlen, ethertype;
372 __le16 fc;
373 const u8 *encaps_data;
374 int encaps_len, skip_header_bytes;
375 int nh_pos, h_pos;
376 int head_need;
377
378 if (unlikely(skb->len < ETH_HLEN))
379 return -EINVAL;
380
381 nh_pos = skb_network_header(skb) - skb->data;
382 h_pos = skb_transport_header(skb) - skb->data;
383
384 /* convert Ethernet header to proper 802.11 header (based on
385 * operation mode) */
386 ethertype = (skb->data[12] << 8) | skb->data[13];
387 fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
388
389 switch (iftype) {
390 case NL80211_IFTYPE_AP:
391 case NL80211_IFTYPE_AP_VLAN:
392 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
393 /* DA BSSID SA */
394 memcpy(hdr.addr1, skb->data, ETH_ALEN);
395 memcpy(hdr.addr2, addr, ETH_ALEN);
396 memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
397 hdrlen = 24;
398 break;
399 case NL80211_IFTYPE_STATION:
400 fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
401 /* BSSID SA DA */
402 memcpy(hdr.addr1, bssid, ETH_ALEN);
403 memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
404 memcpy(hdr.addr3, skb->data, ETH_ALEN);
405 hdrlen = 24;
406 break;
407 case NL80211_IFTYPE_ADHOC:
408 /* DA SA BSSID */
409 memcpy(hdr.addr1, skb->data, ETH_ALEN);
410 memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
411 memcpy(hdr.addr3, bssid, ETH_ALEN);
412 hdrlen = 24;
413 break;
414 default:
415 return -EOPNOTSUPP;
416 }
417
418 if (qos) {
419 fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
420 hdrlen += 2;
421 }
422
423 hdr.frame_control = fc;
424 hdr.duration_id = 0;
425 hdr.seq_ctrl = 0;
426
427 skip_header_bytes = ETH_HLEN;
428 if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
429 encaps_data = bridge_tunnel_header;
430 encaps_len = sizeof(bridge_tunnel_header);
431 skip_header_bytes -= 2;
432 } else if (ethertype > 0x600) {
433 encaps_data = rfc1042_header;
434 encaps_len = sizeof(rfc1042_header);
435 skip_header_bytes -= 2;
436 } else {
437 encaps_data = NULL;
438 encaps_len = 0;
439 }
440
441 skb_pull(skb, skip_header_bytes);
442 nh_pos -= skip_header_bytes;
443 h_pos -= skip_header_bytes;
444
445 head_need = hdrlen + encaps_len - skb_headroom(skb);
446
447 if (head_need > 0 || skb_cloned(skb)) {
448 head_need = max(head_need, 0);
449 if (head_need)
450 skb_orphan(skb);
451
452 if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) {
453 printk(KERN_ERR "failed to reallocate Tx buffer\n");
454 return -ENOMEM;
455 }
456 skb->truesize += head_need;
457 }
458
459 if (encaps_data) {
460 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
461 nh_pos += encaps_len;
462 h_pos += encaps_len;
463 }
464
465 memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
466
467 nh_pos += hdrlen;
468 h_pos += hdrlen;
469
470 /* Update skb pointers to various headers since this modified frame
471 * is going to go through Linux networking code that may potentially
472 * need things like pointer to IP header. */
473 skb_set_mac_header(skb, 0);
474 skb_set_network_header(skb, nh_pos);
475 skb_set_transport_header(skb, h_pos);
476
477 return 0;
478 }
479 EXPORT_SYMBOL(ieee80211_data_from_8023);
480
481 /* Given a data frame determine the 802.1p/1d tag to use. */
482 unsigned int cfg80211_classify8021d(struct sk_buff *skb)
483 {
484 unsigned int dscp;
485
486 /* skb->priority values from 256->263 are magic values to
487 * directly indicate a specific 802.1d priority. This is used
488 * to allow 802.1d priority to be passed directly in from VLAN
489 * tags, etc.
490 */
491 if (skb->priority >= 256 && skb->priority <= 263)
492 return skb->priority - 256;
493
494 switch (skb->protocol) {
495 case htons(ETH_P_IP):
496 dscp = ip_hdr(skb)->tos & 0xfc;
497 break;
498 default:
499 return 0;
500 }
501
502 return dscp >> 5;
503 }
504 EXPORT_SYMBOL(cfg80211_classify8021d);
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