1 /* 2 * HT handling 3 * 4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 5 * Copyright 2002-2005, Instant802 Networks, Inc. 6 * Copyright 2005-2006, Devicescape Software, Inc. 7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 9 * Copyright 2007-2010, Intel Corporation 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #include <linux/ieee80211.h> 17 #include <linux/slab.h> 18 #include <linux/export.h> 19 #include <net/mac80211.h> 20 #include "ieee80211_i.h" 21 #include "driver-ops.h" 22 #include "wme.h" 23 24 /** 25 * DOC: TX A-MPDU aggregation 26 * 27 * Aggregation on the TX side requires setting the hardware flag 28 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed 29 * packets with a flag indicating A-MPDU aggregation. The driver 30 * or device is responsible for actually aggregating the frames, 31 * as well as deciding how many and which to aggregate. 32 * 33 * When TX aggregation is started by some subsystem (usually the rate 34 * control algorithm would be appropriate) by calling the 35 * ieee80211_start_tx_ba_session() function, the driver will be 36 * notified via its @ampdu_action function, with the 37 * %IEEE80211_AMPDU_TX_START action. 38 * 39 * In response to that, the driver is later required to call the 40 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really 41 * start the aggregation session after the peer has also responded. 42 * If the peer responds negatively, the session will be stopped 43 * again right away. Note that it is possible for the aggregation 44 * session to be stopped before the driver has indicated that it 45 * is done setting it up, in which case it must not indicate the 46 * setup completion. 47 * 48 * Also note that, since we also need to wait for a response from 49 * the peer, the driver is notified of the completion of the 50 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the 51 * @ampdu_action callback. 52 * 53 * Similarly, when the aggregation session is stopped by the peer 54 * or something calling ieee80211_stop_tx_ba_session(), the driver's 55 * @ampdu_action function will be called with the action 56 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, 57 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). 58 */ 59 60 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 61 const u8 *da, u16 tid, 62 u8 dialog_token, u16 start_seq_num, 63 u16 agg_size, u16 timeout) 64 { 65 struct ieee80211_local *local = sdata->local; 66 struct sk_buff *skb; 67 struct ieee80211_mgmt *mgmt; 68 u16 capab; 69 70 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 71 72 if (!skb) 73 return; 74 75 skb_reserve(skb, local->hw.extra_tx_headroom); 76 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 77 memset(mgmt, 0, 24); 78 memcpy(mgmt->da, da, ETH_ALEN); 79 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 80 if (sdata->vif.type == NL80211_IFTYPE_AP || 81 sdata->vif.type == NL80211_IFTYPE_AP_VLAN) 82 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 83 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 84 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 85 86 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 87 IEEE80211_STYPE_ACTION); 88 89 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 90 91 mgmt->u.action.category = WLAN_CATEGORY_BACK; 92 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 93 94 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 95 capab = (u16)(1 << 1); /* bit 1 aggregation policy */ 96 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 97 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 98 99 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 100 101 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 102 mgmt->u.action.u.addba_req.start_seq_num = 103 cpu_to_le16(start_seq_num << 4); 104 105 ieee80211_tx_skb(sdata, skb); 106 } 107 108 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) 109 { 110 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 111 struct ieee80211_local *local = sdata->local; 112 struct sk_buff *skb; 113 struct ieee80211_bar *bar; 114 u16 bar_control = 0; 115 116 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); 117 if (!skb) 118 return; 119 120 skb_reserve(skb, local->hw.extra_tx_headroom); 121 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar)); 122 memset(bar, 0, sizeof(*bar)); 123 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 124 IEEE80211_STYPE_BACK_REQ); 125 memcpy(bar->ra, ra, ETH_ALEN); 126 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 127 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 128 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 129 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 130 bar->control = cpu_to_le16(bar_control); 131 bar->start_seq_num = cpu_to_le16(ssn); 132 133 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 134 ieee80211_tx_skb(sdata, skb); 135 } 136 EXPORT_SYMBOL(ieee80211_send_bar); 137 138 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 139 struct tid_ampdu_tx *tid_tx) 140 { 141 lockdep_assert_held(&sta->ampdu_mlme.mtx); 142 lockdep_assert_held(&sta->lock); 143 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 144 } 145 146 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 147 enum ieee80211_back_parties initiator, 148 bool tx) 149 { 150 struct ieee80211_local *local = sta->local; 151 struct tid_ampdu_tx *tid_tx; 152 int ret; 153 154 lockdep_assert_held(&sta->ampdu_mlme.mtx); 155 156 spin_lock_bh(&sta->lock); 157 158 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 159 if (!tid_tx) { 160 spin_unlock_bh(&sta->lock); 161 return -ENOENT; 162 } 163 164 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 165 /* not even started yet! */ 166 ieee80211_assign_tid_tx(sta, tid, NULL); 167 spin_unlock_bh(&sta->lock); 168 kfree_rcu(tid_tx, rcu_head); 169 return 0; 170 } 171 172 spin_unlock_bh(&sta->lock); 173 174 #ifdef CONFIG_MAC80211_HT_DEBUG 175 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", 176 sta->sta.addr, tid); 177 #endif /* CONFIG_MAC80211_HT_DEBUG */ 178 179 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 180 181 del_timer_sync(&tid_tx->addba_resp_timer); 182 183 /* 184 * After this packets are no longer handed right through 185 * to the driver but are put onto tid_tx->pending instead, 186 * with locking to ensure proper access. 187 */ 188 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 189 190 tid_tx->stop_initiator = initiator; 191 tid_tx->tx_stop = tx; 192 193 ret = drv_ampdu_action(local, sta->sdata, 194 IEEE80211_AMPDU_TX_STOP, 195 &sta->sta, tid, NULL, 0); 196 197 /* HW shall not deny going back to legacy */ 198 if (WARN_ON(ret)) { 199 /* 200 * We may have pending packets get stuck in this case... 201 * Not bothering with a workaround for now. 202 */ 203 } 204 205 return ret; 206 } 207 208 /* 209 * After sending add Block Ack request we activated a timer until 210 * add Block Ack response will arrive from the recipient. 211 * If this timer expires sta_addba_resp_timer_expired will be executed. 212 */ 213 static void sta_addba_resp_timer_expired(unsigned long data) 214 { 215 /* not an elegant detour, but there is no choice as the timer passes 216 * only one argument, and both sta_info and TID are needed, so init 217 * flow in sta_info_create gives the TID as data, while the timer_to_id 218 * array gives the sta through container_of */ 219 u16 tid = *(u8 *)data; 220 struct sta_info *sta = container_of((void *)data, 221 struct sta_info, timer_to_tid[tid]); 222 struct tid_ampdu_tx *tid_tx; 223 224 /* check if the TID waits for addBA response */ 225 rcu_read_lock(); 226 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 227 if (!tid_tx || 228 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 229 rcu_read_unlock(); 230 #ifdef CONFIG_MAC80211_HT_DEBUG 231 printk(KERN_DEBUG "timer expired on tid %d but we are not " 232 "(or no longer) expecting addBA response there\n", 233 tid); 234 #endif 235 return; 236 } 237 238 #ifdef CONFIG_MAC80211_HT_DEBUG 239 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid); 240 #endif 241 242 ieee80211_stop_tx_ba_session(&sta->sta, tid); 243 rcu_read_unlock(); 244 } 245 246 static inline int ieee80211_ac_from_tid(int tid) 247 { 248 return ieee802_1d_to_ac[tid & 7]; 249 } 250 251 /* 252 * When multiple aggregation sessions on multiple stations 253 * are being created/destroyed simultaneously, we need to 254 * refcount the global queue stop caused by that in order 255 * to not get into a situation where one of the aggregation 256 * setup or teardown re-enables queues before the other is 257 * ready to handle that. 258 * 259 * These two functions take care of this issue by keeping 260 * a global "agg_queue_stop" refcount. 261 */ 262 static void __acquires(agg_queue) 263 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid) 264 { 265 int queue = ieee80211_ac_from_tid(tid); 266 267 if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1) 268 ieee80211_stop_queue_by_reason( 269 &local->hw, queue, 270 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 271 __acquire(agg_queue); 272 } 273 274 static void __releases(agg_queue) 275 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) 276 { 277 int queue = ieee80211_ac_from_tid(tid); 278 279 if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0) 280 ieee80211_wake_queue_by_reason( 281 &local->hw, queue, 282 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 283 __release(agg_queue); 284 } 285 286 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 287 { 288 struct tid_ampdu_tx *tid_tx; 289 struct ieee80211_local *local = sta->local; 290 struct ieee80211_sub_if_data *sdata = sta->sdata; 291 u16 start_seq_num; 292 int ret; 293 294 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 295 296 /* 297 * While we're asking the driver about the aggregation, 298 * stop the AC queue so that we don't have to worry 299 * about frames that came in while we were doing that, 300 * which would require us to put them to the AC pending 301 * afterwards which just makes the code more complex. 302 */ 303 ieee80211_stop_queue_agg(local, tid); 304 305 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 306 307 /* 308 * make sure no packets are being processed to get 309 * valid starting sequence number 310 */ 311 synchronize_net(); 312 313 start_seq_num = sta->tid_seq[tid] >> 4; 314 315 ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, 316 &sta->sta, tid, &start_seq_num, 0); 317 if (ret) { 318 #ifdef CONFIG_MAC80211_HT_DEBUG 319 printk(KERN_DEBUG "BA request denied - HW unavailable for" 320 " tid %d\n", tid); 321 #endif 322 spin_lock_bh(&sta->lock); 323 ieee80211_assign_tid_tx(sta, tid, NULL); 324 spin_unlock_bh(&sta->lock); 325 326 ieee80211_wake_queue_agg(local, tid); 327 kfree_rcu(tid_tx, rcu_head); 328 return; 329 } 330 331 /* we can take packets again now */ 332 ieee80211_wake_queue_agg(local, tid); 333 334 /* activate the timer for the recipient's addBA response */ 335 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 336 #ifdef CONFIG_MAC80211_HT_DEBUG 337 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid); 338 #endif 339 340 spin_lock_bh(&sta->lock); 341 sta->ampdu_mlme.addba_req_num[tid]++; 342 spin_unlock_bh(&sta->lock); 343 344 /* send AddBA request */ 345 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 346 tid_tx->dialog_token, start_seq_num, 347 local->hw.max_tx_aggregation_subframes, 348 tid_tx->timeout); 349 } 350 351 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 352 u16 timeout) 353 { 354 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 355 struct ieee80211_sub_if_data *sdata = sta->sdata; 356 struct ieee80211_local *local = sdata->local; 357 struct tid_ampdu_tx *tid_tx; 358 int ret = 0; 359 360 trace_api_start_tx_ba_session(pubsta, tid); 361 362 if (WARN_ON(!local->ops->ampdu_action)) 363 return -EINVAL; 364 365 if ((tid >= STA_TID_NUM) || 366 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) || 367 (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) 368 return -EINVAL; 369 370 #ifdef CONFIG_MAC80211_HT_DEBUG 371 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n", 372 pubsta->addr, tid); 373 #endif /* CONFIG_MAC80211_HT_DEBUG */ 374 375 /* 376 * The aggregation code is not prepared to handle 377 * anything but STA/AP due to the BSSID handling. 378 * IBSS could work in the code but isn't supported 379 * by drivers or the standard. 380 */ 381 if (sdata->vif.type != NL80211_IFTYPE_STATION && 382 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 383 sdata->vif.type != NL80211_IFTYPE_AP) 384 return -EINVAL; 385 386 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 387 #ifdef CONFIG_MAC80211_HT_DEBUG 388 printk(KERN_DEBUG "BA sessions blocked. " 389 "Denying BA session request\n"); 390 #endif 391 return -EINVAL; 392 } 393 394 spin_lock_bh(&sta->lock); 395 396 /* we have tried too many times, receiver does not want A-MPDU */ 397 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 398 ret = -EBUSY; 399 goto err_unlock_sta; 400 } 401 402 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 403 /* check if the TID is not in aggregation flow already */ 404 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 405 #ifdef CONFIG_MAC80211_HT_DEBUG 406 printk(KERN_DEBUG "BA request denied - session is not " 407 "idle on tid %u\n", tid); 408 #endif /* CONFIG_MAC80211_HT_DEBUG */ 409 ret = -EAGAIN; 410 goto err_unlock_sta; 411 } 412 413 /* prepare A-MPDU MLME for Tx aggregation */ 414 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 415 if (!tid_tx) { 416 ret = -ENOMEM; 417 goto err_unlock_sta; 418 } 419 420 skb_queue_head_init(&tid_tx->pending); 421 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 422 423 tid_tx->timeout = timeout; 424 425 /* Tx timer */ 426 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; 427 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 428 init_timer(&tid_tx->addba_resp_timer); 429 430 /* assign a dialog token */ 431 sta->ampdu_mlme.dialog_token_allocator++; 432 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 433 434 /* 435 * Finally, assign it to the start array; the work item will 436 * collect it and move it to the normal array. 437 */ 438 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 439 440 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 441 442 /* this flow continues off the work */ 443 err_unlock_sta: 444 spin_unlock_bh(&sta->lock); 445 return ret; 446 } 447 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 448 449 /* 450 * splice packets from the STA's pending to the local pending, 451 * requires a call to ieee80211_agg_splice_finish later 452 */ 453 static void __acquires(agg_queue) 454 ieee80211_agg_splice_packets(struct ieee80211_local *local, 455 struct tid_ampdu_tx *tid_tx, u16 tid) 456 { 457 int queue = ieee80211_ac_from_tid(tid); 458 unsigned long flags; 459 460 ieee80211_stop_queue_agg(local, tid); 461 462 if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates" 463 " from the pending queue\n", tid)) 464 return; 465 466 if (!skb_queue_empty(&tid_tx->pending)) { 467 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 468 /* copy over remaining packets */ 469 skb_queue_splice_tail_init(&tid_tx->pending, 470 &local->pending[queue]); 471 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 472 } 473 } 474 475 static void __releases(agg_queue) 476 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) 477 { 478 ieee80211_wake_queue_agg(local, tid); 479 } 480 481 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 482 struct sta_info *sta, u16 tid) 483 { 484 struct tid_ampdu_tx *tid_tx; 485 486 lockdep_assert_held(&sta->ampdu_mlme.mtx); 487 488 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 489 490 #ifdef CONFIG_MAC80211_HT_DEBUG 491 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); 492 #endif 493 494 drv_ampdu_action(local, sta->sdata, 495 IEEE80211_AMPDU_TX_OPERATIONAL, 496 &sta->sta, tid, NULL, tid_tx->buf_size); 497 498 /* 499 * synchronize with TX path, while splicing the TX path 500 * should block so it won't put more packets onto pending. 501 */ 502 spin_lock_bh(&sta->lock); 503 504 ieee80211_agg_splice_packets(local, tid_tx, tid); 505 /* 506 * Now mark as operational. This will be visible 507 * in the TX path, and lets it go lock-free in 508 * the common case. 509 */ 510 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 511 ieee80211_agg_splice_finish(local, tid); 512 513 spin_unlock_bh(&sta->lock); 514 } 515 516 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) 517 { 518 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 519 struct ieee80211_local *local = sdata->local; 520 struct sta_info *sta; 521 struct tid_ampdu_tx *tid_tx; 522 523 trace_api_start_tx_ba_cb(sdata, ra, tid); 524 525 if (tid >= STA_TID_NUM) { 526 #ifdef CONFIG_MAC80211_HT_DEBUG 527 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 528 tid, STA_TID_NUM); 529 #endif 530 return; 531 } 532 533 mutex_lock(&local->sta_mtx); 534 sta = sta_info_get(sdata, ra); 535 if (!sta) { 536 mutex_unlock(&local->sta_mtx); 537 #ifdef CONFIG_MAC80211_HT_DEBUG 538 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 539 #endif 540 return; 541 } 542 543 mutex_lock(&sta->ampdu_mlme.mtx); 544 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 545 546 if (WARN_ON(!tid_tx)) { 547 #ifdef CONFIG_MAC80211_HT_DEBUG 548 printk(KERN_DEBUG "addBA was not requested!\n"); 549 #endif 550 goto unlock; 551 } 552 553 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 554 goto unlock; 555 556 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 557 ieee80211_agg_tx_operational(local, sta, tid); 558 559 unlock: 560 mutex_unlock(&sta->ampdu_mlme.mtx); 561 mutex_unlock(&local->sta_mtx); 562 } 563 564 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 565 const u8 *ra, u16 tid) 566 { 567 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 568 struct ieee80211_local *local = sdata->local; 569 struct ieee80211_ra_tid *ra_tid; 570 struct sk_buff *skb = dev_alloc_skb(0); 571 572 if (unlikely(!skb)) 573 return; 574 575 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 576 memcpy(&ra_tid->ra, ra, ETH_ALEN); 577 ra_tid->tid = tid; 578 579 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; 580 skb_queue_tail(&sdata->skb_queue, skb); 581 ieee80211_queue_work(&local->hw, &sdata->work); 582 } 583 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 584 585 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 586 enum ieee80211_back_parties initiator, 587 bool tx) 588 { 589 int ret; 590 591 mutex_lock(&sta->ampdu_mlme.mtx); 592 593 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx); 594 595 mutex_unlock(&sta->ampdu_mlme.mtx); 596 597 return ret; 598 } 599 600 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 601 { 602 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 603 struct ieee80211_sub_if_data *sdata = sta->sdata; 604 struct ieee80211_local *local = sdata->local; 605 struct tid_ampdu_tx *tid_tx; 606 int ret = 0; 607 608 trace_api_stop_tx_ba_session(pubsta, tid); 609 610 if (!local->ops->ampdu_action) 611 return -EINVAL; 612 613 if (tid >= STA_TID_NUM) 614 return -EINVAL; 615 616 spin_lock_bh(&sta->lock); 617 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 618 619 if (!tid_tx) { 620 ret = -ENOENT; 621 goto unlock; 622 } 623 624 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 625 /* already in progress stopping it */ 626 ret = 0; 627 goto unlock; 628 } 629 630 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 631 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 632 633 unlock: 634 spin_unlock_bh(&sta->lock); 635 return ret; 636 } 637 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 638 639 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) 640 { 641 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 642 struct ieee80211_local *local = sdata->local; 643 struct sta_info *sta; 644 struct tid_ampdu_tx *tid_tx; 645 646 trace_api_stop_tx_ba_cb(sdata, ra, tid); 647 648 if (tid >= STA_TID_NUM) { 649 #ifdef CONFIG_MAC80211_HT_DEBUG 650 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 651 tid, STA_TID_NUM); 652 #endif 653 return; 654 } 655 656 #ifdef CONFIG_MAC80211_HT_DEBUG 657 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n", 658 ra, tid); 659 #endif /* CONFIG_MAC80211_HT_DEBUG */ 660 661 mutex_lock(&local->sta_mtx); 662 663 sta = sta_info_get(sdata, ra); 664 if (!sta) { 665 #ifdef CONFIG_MAC80211_HT_DEBUG 666 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 667 #endif 668 goto unlock; 669 } 670 671 mutex_lock(&sta->ampdu_mlme.mtx); 672 spin_lock_bh(&sta->lock); 673 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 674 675 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 676 #ifdef CONFIG_MAC80211_HT_DEBUG 677 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); 678 #endif 679 goto unlock_sta; 680 } 681 682 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 683 ieee80211_send_delba(sta->sdata, ra, tid, 684 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 685 686 /* 687 * When we get here, the TX path will not be lockless any more wrt. 688 * aggregation, since the OPERATIONAL bit has long been cleared. 689 * Thus it will block on getting the lock, if it occurs. So if we 690 * stop the queue now, we will not get any more packets, and any 691 * that might be being processed will wait for us here, thereby 692 * guaranteeing that no packets go to the tid_tx pending queue any 693 * more. 694 */ 695 696 ieee80211_agg_splice_packets(local, tid_tx, tid); 697 698 /* future packets must not find the tid_tx struct any more */ 699 ieee80211_assign_tid_tx(sta, tid, NULL); 700 701 ieee80211_agg_splice_finish(local, tid); 702 703 kfree_rcu(tid_tx, rcu_head); 704 705 unlock_sta: 706 spin_unlock_bh(&sta->lock); 707 mutex_unlock(&sta->ampdu_mlme.mtx); 708 unlock: 709 mutex_unlock(&local->sta_mtx); 710 } 711 712 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 713 const u8 *ra, u16 tid) 714 { 715 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 716 struct ieee80211_local *local = sdata->local; 717 struct ieee80211_ra_tid *ra_tid; 718 struct sk_buff *skb = dev_alloc_skb(0); 719 720 if (unlikely(!skb)) 721 return; 722 723 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 724 memcpy(&ra_tid->ra, ra, ETH_ALEN); 725 ra_tid->tid = tid; 726 727 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; 728 skb_queue_tail(&sdata->skb_queue, skb); 729 ieee80211_queue_work(&local->hw, &sdata->work); 730 } 731 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 732 733 734 void ieee80211_process_addba_resp(struct ieee80211_local *local, 735 struct sta_info *sta, 736 struct ieee80211_mgmt *mgmt, 737 size_t len) 738 { 739 struct tid_ampdu_tx *tid_tx; 740 u16 capab, tid; 741 u8 buf_size; 742 743 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 744 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 745 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 746 747 mutex_lock(&sta->ampdu_mlme.mtx); 748 749 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 750 if (!tid_tx) 751 goto out; 752 753 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 754 #ifdef CONFIG_MAC80211_HT_DEBUG 755 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid); 756 #endif 757 goto out; 758 } 759 760 del_timer(&tid_tx->addba_resp_timer); 761 762 #ifdef CONFIG_MAC80211_HT_DEBUG 763 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid); 764 #endif 765 /* 766 * IEEE 802.11-2007 7.3.1.14: 767 * In an ADDBA Response frame, when the Status Code field 768 * is set to 0, the Buffer Size subfield is set to a value 769 * of at least 1. 770 */ 771 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 772 == WLAN_STATUS_SUCCESS && buf_size) { 773 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 774 &tid_tx->state)) { 775 /* ignore duplicate response */ 776 goto out; 777 } 778 779 tid_tx->buf_size = buf_size; 780 781 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 782 ieee80211_agg_tx_operational(local, sta, tid); 783 784 sta->ampdu_mlme.addba_req_num[tid] = 0; 785 } else { 786 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 787 true); 788 } 789 790 out: 791 mutex_unlock(&sta->ampdu_mlme.mtx); 792 } 793