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Johannes Bergc2d15602007-07-27 15:43:23 +02001/*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * utilities for mac80211
12 */
13
14#include <net/mac80211.h>
15#include <linux/netdevice.h>
16#include <linux/types.h>
17#include <linux/slab.h>
18#include <linux/skbuff.h>
19#include <linux/etherdevice.h>
20#include <linux/if_arp.h>
21#include <linux/wireless.h>
22#include <linux/bitmap.h>
Eric W. Biederman881d9662007-09-17 11:56:21 -070023#include <net/net_namespace.h>
Johannes Bergc2d15602007-07-27 15:43:23 +020024#include <net/cfg80211.h>
Johannes Bergdabeb342007-11-09 01:57:29 +010025#include <net/rtnetlink.h>
Johannes Bergc2d15602007-07-27 15:43:23 +020026
27#include "ieee80211_i.h"
Johannes Berg2c8dccc2008-04-08 15:14:40 -040028#include "rate.h"
Luis Carlos Coboee385852008-02-23 15:17:11 +010029#include "mesh.h"
Johannes Bergc2d15602007-07-27 15:43:23 +020030#include "wme.h"
31
32/* privid for wiphys to determine whether they belong to us or not */
33void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
34
35/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
36/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
Senthil Balasubramanianc97c23e2008-05-28 23:15:32 +053037const unsigned char rfc1042_header[] __aligned(2) =
Johannes Bergc2d15602007-07-27 15:43:23 +020038 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
39
40/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
Senthil Balasubramanianc97c23e2008-05-28 23:15:32 +053041const unsigned char bridge_tunnel_header[] __aligned(2) =
Johannes Bergc2d15602007-07-27 15:43:23 +020042 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
43
Johannes Bergc2d15602007-07-27 15:43:23 +020044
Ron Rindjunsky71364712007-12-25 17:00:36 +020045u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
46 enum ieee80211_if_types type)
Johannes Bergc2d15602007-07-27 15:43:23 +020047{
48 u16 fc;
49
Ron Rindjunsky98f0b0a2007-12-18 17:23:53 +020050 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
51 if (len < 16)
Johannes Bergc2d15602007-07-27 15:43:23 +020052 return NULL;
53
54 fc = le16_to_cpu(hdr->frame_control);
55
56 switch (fc & IEEE80211_FCTL_FTYPE) {
57 case IEEE80211_FTYPE_DATA:
Ron Rindjunsky98f0b0a2007-12-18 17:23:53 +020058 if (len < 24) /* drop incorrect hdr len (data) */
59 return NULL;
Johannes Bergc2d15602007-07-27 15:43:23 +020060 switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
61 case IEEE80211_FCTL_TODS:
62 return hdr->addr1;
63 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
64 return NULL;
65 case IEEE80211_FCTL_FROMDS:
66 return hdr->addr2;
67 case 0:
68 return hdr->addr3;
69 }
70 break;
71 case IEEE80211_FTYPE_MGMT:
Ron Rindjunsky98f0b0a2007-12-18 17:23:53 +020072 if (len < 24) /* drop incorrect hdr len (mgmt) */
73 return NULL;
Johannes Bergc2d15602007-07-27 15:43:23 +020074 return hdr->addr3;
75 case IEEE80211_FTYPE_CTL:
76 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
77 return hdr->addr1;
Ron Rindjunsky71364712007-12-25 17:00:36 +020078 else if ((fc & IEEE80211_FCTL_STYPE) ==
79 IEEE80211_STYPE_BACK_REQ) {
80 switch (type) {
81 case IEEE80211_IF_TYPE_STA:
82 return hdr->addr2;
83 case IEEE80211_IF_TYPE_AP:
84 case IEEE80211_IF_TYPE_VLAN:
85 return hdr->addr1;
86 default:
87 return NULL;
88 }
89 }
Johannes Bergc2d15602007-07-27 15:43:23 +020090 else
91 return NULL;
92 }
93
94 return NULL;
95}
96
97int ieee80211_get_hdrlen(u16 fc)
98{
99 int hdrlen = 24;
100
101 switch (fc & IEEE80211_FCTL_FTYPE) {
102 case IEEE80211_FTYPE_DATA:
103 if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
104 hdrlen = 30; /* Addr4 */
105 /*
106 * The QoS Control field is two bytes and its presence is
107 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
108 * hdrlen if that bit is set.
109 * This works by masking out the bit and shifting it to
110 * bit position 1 so the result has the value 0 or 2.
111 */
112 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
113 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
114 break;
115 case IEEE80211_FTYPE_CTL:
116 /*
117 * ACK and CTS are 10 bytes, all others 16. To see how
118 * to get this condition consider
119 * subtype mask: 0b0000000011110000 (0x00F0)
120 * ACK subtype: 0b0000000011010000 (0x00D0)
121 * CTS subtype: 0b0000000011000000 (0x00C0)
122 * bits that matter: ^^^ (0x00E0)
123 * value of those: 0b0000000011000000 (0x00C0)
124 */
125 if ((fc & 0xE0) == 0xC0)
126 hdrlen = 10;
127 else
128 hdrlen = 16;
129 break;
130 }
131
132 return hdrlen;
133}
134EXPORT_SYMBOL(ieee80211_get_hdrlen);
135
136int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
137{
138 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
139 int hdrlen;
140
141 if (unlikely(skb->len < 10))
142 return 0;
143 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
144 if (unlikely(hdrlen > skb->len))
145 return 0;
146 return hdrlen;
147}
148EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
149
Luis Carlos Coboee385852008-02-23 15:17:11 +0100150int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
151{
152 int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
153 /* 7.1.3.5a.2 */
154 switch (ae) {
155 case 0:
Luis Carlos Coboef269252008-05-05 12:02:35 -0700156 return 6;
Luis Carlos Coboee385852008-02-23 15:17:11 +0100157 case 1:
Luis Carlos Coboef269252008-05-05 12:02:35 -0700158 return 12;
Luis Carlos Coboee385852008-02-23 15:17:11 +0100159 case 2:
Luis Carlos Coboef269252008-05-05 12:02:35 -0700160 return 18;
Luis Carlos Coboee385852008-02-23 15:17:11 +0100161 case 3:
Luis Carlos Coboef269252008-05-05 12:02:35 -0700162 return 24;
Luis Carlos Coboee385852008-02-23 15:17:11 +0100163 default:
Luis Carlos Coboef269252008-05-05 12:02:35 -0700164 return 6;
Luis Carlos Coboee385852008-02-23 15:17:11 +0100165 }
166}
Luis Carlos Coboee385852008-02-23 15:17:11 +0100167
Johannes Berg5cf121c2008-02-25 16:27:43 +0100168void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
Johannes Bergc2d15602007-07-27 15:43:23 +0200169{
170 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
171
172 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
Johannes Berg5cf121c2008-02-25 16:27:43 +0100173 if (tx->extra_frag) {
Johannes Bergc2d15602007-07-27 15:43:23 +0200174 struct ieee80211_hdr *fhdr;
175 int i;
Johannes Berg5cf121c2008-02-25 16:27:43 +0100176 for (i = 0; i < tx->num_extra_frag; i++) {
Johannes Bergc2d15602007-07-27 15:43:23 +0200177 fhdr = (struct ieee80211_hdr *)
Johannes Berg5cf121c2008-02-25 16:27:43 +0100178 tx->extra_frag[i]->data;
Johannes Bergc2d15602007-07-27 15:43:23 +0200179 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
180 }
181 }
182}
183
184int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
185 int rate, int erp, int short_preamble)
186{
187 int dur;
188
189 /* calculate duration (in microseconds, rounded up to next higher
190 * integer if it includes a fractional microsecond) to send frame of
191 * len bytes (does not include FCS) at the given rate. Duration will
192 * also include SIFS.
193 *
194 * rate is in 100 kbps, so divident is multiplied by 10 in the
195 * DIV_ROUND_UP() operations.
196 */
197
Johannes Berg8318d782008-01-24 19:38:38 +0100198 if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
Johannes Bergc2d15602007-07-27 15:43:23 +0200199 /*
200 * OFDM:
201 *
202 * N_DBPS = DATARATE x 4
203 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
204 * (16 = SIGNAL time, 6 = tail bits)
205 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
206 *
207 * T_SYM = 4 usec
208 * 802.11a - 17.5.2: aSIFSTime = 16 usec
209 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
210 * signal ext = 6 usec
211 */
Johannes Bergc2d15602007-07-27 15:43:23 +0200212 dur = 16; /* SIFS + signal ext */
213 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
214 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
215 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
216 4 * rate); /* T_SYM x N_SYM */
217 } else {
218 /*
219 * 802.11b or 802.11g with 802.11b compatibility:
220 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
221 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
222 *
223 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
224 * aSIFSTime = 10 usec
225 * aPreambleLength = 144 usec or 72 usec with short preamble
226 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
227 */
228 dur = 10; /* aSIFSTime = 10 usec */
229 dur += short_preamble ? (72 + 24) : (144 + 48);
230
231 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
232 }
233
234 return dur;
235}
236
237/* Exported duration function for driver use */
Johannes Berg32bfd352007-12-19 01:31:26 +0100238__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
239 struct ieee80211_vif *vif,
Johannes Berg8318d782008-01-24 19:38:38 +0100240 size_t frame_len,
241 struct ieee80211_rate *rate)
Johannes Bergc2d15602007-07-27 15:43:23 +0200242{
243 struct ieee80211_local *local = hw_to_local(hw);
Johannes Berg32bfd352007-12-19 01:31:26 +0100244 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
Johannes Bergc2d15602007-07-27 15:43:23 +0200245 u16 dur;
246 int erp;
247
Johannes Berg8318d782008-01-24 19:38:38 +0100248 erp = 0;
249 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
250 erp = rate->flags & IEEE80211_RATE_ERP_G;
251
252 dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
Johannes Berg471b3ef2007-12-28 14:32:58 +0100253 sdata->bss_conf.use_short_preamble);
Johannes Bergc2d15602007-07-27 15:43:23 +0200254
255 return cpu_to_le16(dur);
256}
257EXPORT_SYMBOL(ieee80211_generic_frame_duration);
258
Johannes Berg32bfd352007-12-19 01:31:26 +0100259__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
260 struct ieee80211_vif *vif, size_t frame_len,
Johannes Bergc2d15602007-07-27 15:43:23 +0200261 const struct ieee80211_tx_control *frame_txctl)
262{
263 struct ieee80211_local *local = hw_to_local(hw);
264 struct ieee80211_rate *rate;
Johannes Berg32bfd352007-12-19 01:31:26 +0100265 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
Johannes Berg471b3ef2007-12-28 14:32:58 +0100266 bool short_preamble;
Johannes Bergc2d15602007-07-27 15:43:23 +0200267 int erp;
268 u16 dur;
269
Johannes Berg471b3ef2007-12-28 14:32:58 +0100270 short_preamble = sdata->bss_conf.use_short_preamble;
Daniel Drake7e9ed182007-07-27 15:43:24 +0200271
Johannes Berg8318d782008-01-24 19:38:38 +0100272 rate = frame_txctl->rts_cts_rate;
273
274 erp = 0;
275 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
276 erp = rate->flags & IEEE80211_RATE_ERP_G;
Johannes Bergc2d15602007-07-27 15:43:23 +0200277
278 /* CTS duration */
Johannes Berg8318d782008-01-24 19:38:38 +0100279 dur = ieee80211_frame_duration(local, 10, rate->bitrate,
Johannes Bergc2d15602007-07-27 15:43:23 +0200280 erp, short_preamble);
281 /* Data frame duration */
Johannes Berg8318d782008-01-24 19:38:38 +0100282 dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
Johannes Bergc2d15602007-07-27 15:43:23 +0200283 erp, short_preamble);
284 /* ACK duration */
Johannes Berg8318d782008-01-24 19:38:38 +0100285 dur += ieee80211_frame_duration(local, 10, rate->bitrate,
Johannes Bergc2d15602007-07-27 15:43:23 +0200286 erp, short_preamble);
287
288 return cpu_to_le16(dur);
289}
290EXPORT_SYMBOL(ieee80211_rts_duration);
291
Johannes Berg32bfd352007-12-19 01:31:26 +0100292__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
293 struct ieee80211_vif *vif,
Johannes Bergc2d15602007-07-27 15:43:23 +0200294 size_t frame_len,
295 const struct ieee80211_tx_control *frame_txctl)
296{
297 struct ieee80211_local *local = hw_to_local(hw);
298 struct ieee80211_rate *rate;
Johannes Berg32bfd352007-12-19 01:31:26 +0100299 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
Johannes Berg471b3ef2007-12-28 14:32:58 +0100300 bool short_preamble;
Johannes Bergc2d15602007-07-27 15:43:23 +0200301 int erp;
302 u16 dur;
303
Johannes Berg471b3ef2007-12-28 14:32:58 +0100304 short_preamble = sdata->bss_conf.use_short_preamble;
Daniel Drake7e9ed182007-07-27 15:43:24 +0200305
Johannes Berg8318d782008-01-24 19:38:38 +0100306 rate = frame_txctl->rts_cts_rate;
307 erp = 0;
308 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
309 erp = rate->flags & IEEE80211_RATE_ERP_G;
Johannes Bergc2d15602007-07-27 15:43:23 +0200310
311 /* Data frame duration */
Johannes Berg8318d782008-01-24 19:38:38 +0100312 dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
Johannes Bergc2d15602007-07-27 15:43:23 +0200313 erp, short_preamble);
314 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
315 /* ACK duration */
Johannes Berg8318d782008-01-24 19:38:38 +0100316 dur += ieee80211_frame_duration(local, 10, rate->bitrate,
Johannes Bergc2d15602007-07-27 15:43:23 +0200317 erp, short_preamble);
318 }
319
Johannes Bergc2d15602007-07-27 15:43:23 +0200320 return cpu_to_le16(dur);
321}
322EXPORT_SYMBOL(ieee80211_ctstoself_duration);
323
Johannes Bergc2d15602007-07-27 15:43:23 +0200324void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
325{
326 struct ieee80211_local *local = hw_to_local(hw);
327
328 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
329 &local->state[queue])) {
330 if (test_bit(IEEE80211_LINK_STATE_PENDING,
331 &local->state[queue]))
332 tasklet_schedule(&local->tx_pending_tasklet);
333 else
334 if (!ieee80211_qdisc_installed(local->mdev)) {
335 if (queue == 0)
336 netif_wake_queue(local->mdev);
337 } else
338 __netif_schedule(local->mdev);
339 }
340}
341EXPORT_SYMBOL(ieee80211_wake_queue);
342
343void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
344{
345 struct ieee80211_local *local = hw_to_local(hw);
346
347 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
348 netif_stop_queue(local->mdev);
349 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
350}
351EXPORT_SYMBOL(ieee80211_stop_queue);
352
353void ieee80211_start_queues(struct ieee80211_hw *hw)
354{
355 struct ieee80211_local *local = hw_to_local(hw);
356 int i;
357
358 for (i = 0; i < local->hw.queues; i++)
359 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
360 if (!ieee80211_qdisc_installed(local->mdev))
361 netif_start_queue(local->mdev);
362}
363EXPORT_SYMBOL(ieee80211_start_queues);
364
365void ieee80211_stop_queues(struct ieee80211_hw *hw)
366{
367 int i;
368
369 for (i = 0; i < hw->queues; i++)
370 ieee80211_stop_queue(hw, i);
371}
372EXPORT_SYMBOL(ieee80211_stop_queues);
373
374void ieee80211_wake_queues(struct ieee80211_hw *hw)
375{
376 int i;
377
378 for (i = 0; i < hw->queues; i++)
379 ieee80211_wake_queue(hw, i);
380}
381EXPORT_SYMBOL(ieee80211_wake_queues);
Johannes Bergdabeb342007-11-09 01:57:29 +0100382
Johannes Berg32bfd352007-12-19 01:31:26 +0100383void ieee80211_iterate_active_interfaces(
384 struct ieee80211_hw *hw,
385 void (*iterator)(void *data, u8 *mac,
386 struct ieee80211_vif *vif),
387 void *data)
Johannes Bergdabeb342007-11-09 01:57:29 +0100388{
389 struct ieee80211_local *local = hw_to_local(hw);
390 struct ieee80211_sub_if_data *sdata;
391
Ivo van Doorn2f561fe2008-05-10 13:40:49 +0200392 rtnl_lock();
393
394 list_for_each_entry(sdata, &local->interfaces, list) {
395 switch (sdata->vif.type) {
396 case IEEE80211_IF_TYPE_INVALID:
397 case IEEE80211_IF_TYPE_MNTR:
398 case IEEE80211_IF_TYPE_VLAN:
399 continue;
400 case IEEE80211_IF_TYPE_AP:
401 case IEEE80211_IF_TYPE_STA:
402 case IEEE80211_IF_TYPE_IBSS:
403 case IEEE80211_IF_TYPE_WDS:
404 case IEEE80211_IF_TYPE_MESH_POINT:
405 break;
406 }
407 if (sdata->dev == local->mdev)
408 continue;
409 if (netif_running(sdata->dev))
410 iterator(data, sdata->dev->dev_addr,
411 &sdata->vif);
412 }
413
414 rtnl_unlock();
415}
416EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
417
418void ieee80211_iterate_active_interfaces_atomic(
419 struct ieee80211_hw *hw,
420 void (*iterator)(void *data, u8 *mac,
421 struct ieee80211_vif *vif),
422 void *data)
423{
424 struct ieee80211_local *local = hw_to_local(hw);
425 struct ieee80211_sub_if_data *sdata;
426
Johannes Berge38bad42007-11-28 10:55:32 +0100427 rcu_read_lock();
Johannes Bergdabeb342007-11-09 01:57:29 +0100428
Johannes Berge38bad42007-11-28 10:55:32 +0100429 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
Johannes Berg51fb61e2007-12-19 01:31:27 +0100430 switch (sdata->vif.type) {
Johannes Bergdabeb342007-11-09 01:57:29 +0100431 case IEEE80211_IF_TYPE_INVALID:
432 case IEEE80211_IF_TYPE_MNTR:
433 case IEEE80211_IF_TYPE_VLAN:
434 continue;
435 case IEEE80211_IF_TYPE_AP:
436 case IEEE80211_IF_TYPE_STA:
437 case IEEE80211_IF_TYPE_IBSS:
438 case IEEE80211_IF_TYPE_WDS:
Johannes Berg6032f932008-02-23 15:17:07 +0100439 case IEEE80211_IF_TYPE_MESH_POINT:
Johannes Bergdabeb342007-11-09 01:57:29 +0100440 break;
441 }
442 if (sdata->dev == local->mdev)
443 continue;
444 if (netif_running(sdata->dev))
445 iterator(data, sdata->dev->dev_addr,
Johannes Berg32bfd352007-12-19 01:31:26 +0100446 &sdata->vif);
Johannes Bergdabeb342007-11-09 01:57:29 +0100447 }
Johannes Berge38bad42007-11-28 10:55:32 +0100448
449 rcu_read_unlock();
Johannes Bergdabeb342007-11-09 01:57:29 +0100450}
Ivo van Doorn2f561fe2008-05-10 13:40:49 +0200451EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);