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 <net/mac80211.h> 19 #include "ieee80211_i.h" 20 #include "driver-ops.h" 21 #include "wme.h" 22 23 /** 24 * DOC: TX A-MPDU aggregation 25 * 26 * Aggregation on the TX side requires setting the hardware flag 27 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed 28 * packets with a flag indicating A-MPDU aggregation. The driver 29 * or device is responsible for actually aggregating the frames, 30 * as well as deciding how many and which to aggregate. 31 * 32 * When TX aggregation is started by some subsystem (usually the rate 33 * control algorithm would be appropriate) by calling the 34 * ieee80211_start_tx_ba_session() function, the driver will be 35 * notified via its @ampdu_action function, with the 36 * %IEEE80211_AMPDU_TX_START action. 37 * 38 * In response to that, the driver is later required to call the 39 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really 40 * start the aggregation session after the peer has also responded. 41 * If the peer responds negatively, the session will be stopped 42 * again right away. Note that it is possible for the aggregation 43 * session to be stopped before the driver has indicated that it 44 * is done setting it up, in which case it must not indicate the 45 * setup completion. 46 * 47 * Also note that, since we also need to wait for a response from 48 * the peer, the driver is notified of the completion of the 49 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the 50 * @ampdu_action callback. 51 * 52 * Similarly, when the aggregation session is stopped by the peer 53 * or something calling ieee80211_stop_tx_ba_session(), the driver's 54 * @ampdu_action function will be called with the action 55 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, 56 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). 57 */ 58 59 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 60 const u8 *da, u16 tid, 61 u8 dialog_token, u16 start_seq_num, 62 u16 agg_size, u16 timeout) 63 { 64 struct ieee80211_local *local = sdata->local; 65 struct sk_buff *skb; 66 struct ieee80211_mgmt *mgmt; 67 u16 capab; 68 69 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 70 71 if (!skb) { 72 printk(KERN_ERR "%s: failed to allocate buffer " 73 "for addba request frame\n", sdata->name); 74 return; 75 } 76 skb_reserve(skb, local->hw.extra_tx_headroom); 77 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 78 memset(mgmt, 0, 24); 79 memcpy(mgmt->da, da, ETH_ALEN); 80 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 81 if (sdata->vif.type == NL80211_IFTYPE_AP || 82 sdata->vif.type == NL80211_IFTYPE_AP_VLAN) 83 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 84 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 85 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 86 87 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 88 IEEE80211_STYPE_ACTION); 89 90 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 91 92 mgmt->u.action.category = WLAN_CATEGORY_BACK; 93 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 94 95 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 96 capab = (u16)(1 << 1); /* bit 1 aggregation policy */ 97 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 98 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 99 100 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 101 102 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 103 mgmt->u.action.u.addba_req.start_seq_num = 104 cpu_to_le16(start_seq_num << 4); 105 106 ieee80211_tx_skb(sdata, skb); 107 } 108 109 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn) 110 { 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 printk(KERN_ERR "%s: failed to allocate buffer for " 119 "bar frame\n", sdata->name); 120 return; 121 } 122 skb_reserve(skb, local->hw.extra_tx_headroom); 123 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar)); 124 memset(bar, 0, sizeof(*bar)); 125 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 126 IEEE80211_STYPE_BACK_REQ); 127 memcpy(bar->ra, ra, ETH_ALEN); 128 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 129 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 130 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 131 bar_control |= (u16)(tid << 12); 132 bar->control = cpu_to_le16(bar_control); 133 bar->start_seq_num = cpu_to_le16(ssn); 134 135 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 136 ieee80211_tx_skb(sdata, skb); 137 } 138 139 static void kfree_tid_tx(struct rcu_head *rcu_head) 140 { 141 struct tid_ampdu_tx *tid_tx = 142 container_of(rcu_head, struct tid_ampdu_tx, rcu_head); 143 144 kfree(tid_tx); 145 } 146 147 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 148 enum ieee80211_back_parties initiator, 149 bool tx) 150 { 151 struct ieee80211_local *local = sta->local; 152 struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid]; 153 int ret; 154 155 lockdep_assert_held(&sta->ampdu_mlme.mtx); 156 157 if (!tid_tx) 158 return -ENOENT; 159 160 spin_lock_bh(&sta->lock); 161 162 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 163 /* not even started yet! */ 164 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL); 165 spin_unlock_bh(&sta->lock); 166 call_rcu(&tid_tx->rcu_head, kfree_tid_tx); 167 return 0; 168 } 169 170 spin_unlock_bh(&sta->lock); 171 172 #ifdef CONFIG_MAC80211_HT_DEBUG 173 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", 174 sta->sta.addr, tid); 175 #endif /* CONFIG_MAC80211_HT_DEBUG */ 176 177 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 178 179 del_timer_sync(&tid_tx->addba_resp_timer); 180 181 /* 182 * After this packets are no longer handed right through 183 * to the driver but are put onto tid_tx->pending instead, 184 * with locking to ensure proper access. 185 */ 186 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 187 188 tid_tx->stop_initiator = initiator; 189 tid_tx->tx_stop = tx; 190 191 ret = drv_ampdu_action(local, sta->sdata, 192 IEEE80211_AMPDU_TX_STOP, 193 &sta->sta, tid, NULL); 194 195 /* HW shall not deny going back to legacy */ 196 if (WARN_ON(ret)) { 197 /* 198 * We may have pending packets get stuck in this case... 199 * Not bothering with a workaround for now. 200 */ 201 } 202 203 return ret; 204 } 205 206 /* 207 * After sending add Block Ack request we activated a timer until 208 * add Block Ack response will arrive from the recipient. 209 * If this timer expires sta_addba_resp_timer_expired will be executed. 210 */ 211 static void sta_addba_resp_timer_expired(unsigned long data) 212 { 213 /* not an elegant detour, but there is no choice as the timer passes 214 * only one argument, and both sta_info and TID are needed, so init 215 * flow in sta_info_create gives the TID as data, while the timer_to_id 216 * array gives the sta through container_of */ 217 u16 tid = *(u8 *)data; 218 struct sta_info *sta = container_of((void *)data, 219 struct sta_info, timer_to_tid[tid]); 220 struct tid_ampdu_tx *tid_tx; 221 222 /* check if the TID waits for addBA response */ 223 rcu_read_lock(); 224 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 225 if (!tid_tx || 226 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 227 rcu_read_unlock(); 228 #ifdef CONFIG_MAC80211_HT_DEBUG 229 printk(KERN_DEBUG "timer expired on tid %d but we are not " 230 "(or no longer) expecting addBA response there\n", 231 tid); 232 #endif 233 return; 234 } 235 236 #ifdef CONFIG_MAC80211_HT_DEBUG 237 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid); 238 #endif 239 240 ieee80211_stop_tx_ba_session(&sta->sta, tid); 241 rcu_read_unlock(); 242 } 243 244 static inline int ieee80211_ac_from_tid(int tid) 245 { 246 return ieee802_1d_to_ac[tid & 7]; 247 } 248 249 /* 250 * When multiple aggregation sessions on multiple stations 251 * are being created/destroyed simultaneously, we need to 252 * refcount the global queue stop caused by that in order 253 * to not get into a situation where one of the aggregation 254 * setup or teardown re-enables queues before the other is 255 * ready to handle that. 256 * 257 * These two functions take care of this issue by keeping 258 * a global "agg_queue_stop" refcount. 259 */ 260 static void __acquires(agg_queue) 261 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid) 262 { 263 int queue = ieee80211_ac_from_tid(tid); 264 265 if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1) 266 ieee80211_stop_queue_by_reason( 267 &local->hw, queue, 268 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 269 __acquire(agg_queue); 270 } 271 272 static void __releases(agg_queue) 273 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) 274 { 275 int queue = ieee80211_ac_from_tid(tid); 276 277 if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0) 278 ieee80211_wake_queue_by_reason( 279 &local->hw, queue, 280 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 281 __release(agg_queue); 282 } 283 284 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 285 { 286 struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid]; 287 struct ieee80211_local *local = sta->local; 288 struct ieee80211_sub_if_data *sdata = sta->sdata; 289 u16 start_seq_num; 290 int ret; 291 292 lockdep_assert_held(&sta->ampdu_mlme.mtx); 293 294 /* 295 * While we're asking the driver about the aggregation, 296 * stop the AC queue so that we don't have to worry 297 * about frames that came in while we were doing that, 298 * which would require us to put them to the AC pending 299 * afterwards which just makes the code more complex. 300 */ 301 ieee80211_stop_queue_agg(local, tid); 302 303 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 304 305 /* 306 * make sure no packets are being processed to get 307 * valid starting sequence number 308 */ 309 synchronize_net(); 310 311 start_seq_num = sta->tid_seq[tid] >> 4; 312 313 ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, 314 &sta->sta, tid, &start_seq_num); 315 if (ret) { 316 #ifdef CONFIG_MAC80211_HT_DEBUG 317 printk(KERN_DEBUG "BA request denied - HW unavailable for" 318 " tid %d\n", tid); 319 #endif 320 spin_lock_bh(&sta->lock); 321 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL); 322 spin_unlock_bh(&sta->lock); 323 324 ieee80211_wake_queue_agg(local, tid); 325 call_rcu(&tid_tx->rcu_head, kfree_tid_tx); 326 return; 327 } 328 329 /* we can take packets again now */ 330 ieee80211_wake_queue_agg(local, tid); 331 332 /* activate the timer for the recipient's addBA response */ 333 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 334 #ifdef CONFIG_MAC80211_HT_DEBUG 335 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid); 336 #endif 337 338 spin_lock_bh(&sta->lock); 339 sta->ampdu_mlme.addba_req_num[tid]++; 340 spin_unlock_bh(&sta->lock); 341 342 /* send AddBA request */ 343 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 344 tid_tx->dialog_token, start_seq_num, 345 0x40, 5000); 346 } 347 348 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 349 { 350 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 351 struct ieee80211_sub_if_data *sdata = sta->sdata; 352 struct ieee80211_local *local = sdata->local; 353 struct tid_ampdu_tx *tid_tx; 354 int ret = 0; 355 356 trace_api_start_tx_ba_session(pubsta, tid); 357 358 if (WARN_ON(!local->ops->ampdu_action)) 359 return -EINVAL; 360 361 if ((tid >= STA_TID_NUM) || 362 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) 363 return -EINVAL; 364 365 #ifdef CONFIG_MAC80211_HT_DEBUG 366 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n", 367 pubsta->addr, tid); 368 #endif /* CONFIG_MAC80211_HT_DEBUG */ 369 370 /* 371 * The aggregation code is not prepared to handle 372 * anything but STA/AP due to the BSSID handling. 373 * IBSS could work in the code but isn't supported 374 * by drivers or the standard. 375 */ 376 if (sdata->vif.type != NL80211_IFTYPE_STATION && 377 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 378 sdata->vif.type != NL80211_IFTYPE_AP) 379 return -EINVAL; 380 381 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) { 382 #ifdef CONFIG_MAC80211_HT_DEBUG 383 printk(KERN_DEBUG "BA sessions blocked. " 384 "Denying BA session request\n"); 385 #endif 386 return -EINVAL; 387 } 388 389 spin_lock_bh(&sta->lock); 390 391 /* we have tried too many times, receiver does not want A-MPDU */ 392 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 393 ret = -EBUSY; 394 goto err_unlock_sta; 395 } 396 397 tid_tx = sta->ampdu_mlme.tid_tx[tid]; 398 /* check if the TID is not in aggregation flow already */ 399 if (tid_tx) { 400 #ifdef CONFIG_MAC80211_HT_DEBUG 401 printk(KERN_DEBUG "BA request denied - session is not " 402 "idle on tid %u\n", tid); 403 #endif /* CONFIG_MAC80211_HT_DEBUG */ 404 ret = -EAGAIN; 405 goto err_unlock_sta; 406 } 407 408 /* prepare A-MPDU MLME for Tx aggregation */ 409 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 410 if (!tid_tx) { 411 #ifdef CONFIG_MAC80211_HT_DEBUG 412 if (net_ratelimit()) 413 printk(KERN_ERR "allocate tx mlme to tid %d failed\n", 414 tid); 415 #endif 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 /* Tx timer */ 424 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; 425 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 426 init_timer(&tid_tx->addba_resp_timer); 427 428 /* assign a dialog token */ 429 sta->ampdu_mlme.dialog_token_allocator++; 430 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 431 432 /* finally, assign it to the array */ 433 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 434 435 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 436 437 /* this flow continues off the work */ 438 err_unlock_sta: 439 spin_unlock_bh(&sta->lock); 440 return ret; 441 } 442 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 443 444 /* 445 * splice packets from the STA's pending to the local pending, 446 * requires a call to ieee80211_agg_splice_finish later 447 */ 448 static void __acquires(agg_queue) 449 ieee80211_agg_splice_packets(struct ieee80211_local *local, 450 struct tid_ampdu_tx *tid_tx, u16 tid) 451 { 452 int queue = ieee80211_ac_from_tid(tid); 453 unsigned long flags; 454 455 ieee80211_stop_queue_agg(local, tid); 456 457 if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates" 458 " from the pending queue\n", tid)) 459 return; 460 461 if (!skb_queue_empty(&tid_tx->pending)) { 462 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 463 /* copy over remaining packets */ 464 skb_queue_splice_tail_init(&tid_tx->pending, 465 &local->pending[queue]); 466 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 467 } 468 } 469 470 static void __releases(agg_queue) 471 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) 472 { 473 ieee80211_wake_queue_agg(local, tid); 474 } 475 476 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 477 struct sta_info *sta, u16 tid) 478 { 479 lockdep_assert_held(&sta->ampdu_mlme.mtx); 480 481 #ifdef CONFIG_MAC80211_HT_DEBUG 482 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); 483 #endif 484 485 drv_ampdu_action(local, sta->sdata, 486 IEEE80211_AMPDU_TX_OPERATIONAL, 487 &sta->sta, tid, NULL); 488 489 /* 490 * synchronize with TX path, while splicing the TX path 491 * should block so it won't put more packets onto pending. 492 */ 493 spin_lock_bh(&sta->lock); 494 495 ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid); 496 /* 497 * Now mark as operational. This will be visible 498 * in the TX path, and lets it go lock-free in 499 * the common case. 500 */ 501 set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state); 502 ieee80211_agg_splice_finish(local, tid); 503 504 spin_unlock_bh(&sta->lock); 505 } 506 507 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) 508 { 509 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 510 struct ieee80211_local *local = sdata->local; 511 struct sta_info *sta; 512 struct tid_ampdu_tx *tid_tx; 513 514 trace_api_start_tx_ba_cb(sdata, ra, tid); 515 516 if (tid >= STA_TID_NUM) { 517 #ifdef CONFIG_MAC80211_HT_DEBUG 518 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 519 tid, STA_TID_NUM); 520 #endif 521 return; 522 } 523 524 mutex_lock(&local->sta_mtx); 525 sta = sta_info_get(sdata, ra); 526 if (!sta) { 527 mutex_unlock(&local->sta_mtx); 528 #ifdef CONFIG_MAC80211_HT_DEBUG 529 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 530 #endif 531 return; 532 } 533 534 mutex_lock(&sta->ampdu_mlme.mtx); 535 tid_tx = sta->ampdu_mlme.tid_tx[tid]; 536 537 if (WARN_ON(!tid_tx)) { 538 #ifdef CONFIG_MAC80211_HT_DEBUG 539 printk(KERN_DEBUG "addBA was not requested!\n"); 540 #endif 541 goto unlock; 542 } 543 544 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 545 goto unlock; 546 547 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 548 ieee80211_agg_tx_operational(local, sta, tid); 549 550 unlock: 551 mutex_unlock(&sta->ampdu_mlme.mtx); 552 mutex_unlock(&local->sta_mtx); 553 } 554 555 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 556 const u8 *ra, u16 tid) 557 { 558 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 559 struct ieee80211_local *local = sdata->local; 560 struct ieee80211_ra_tid *ra_tid; 561 struct sk_buff *skb = dev_alloc_skb(0); 562 563 if (unlikely(!skb)) { 564 #ifdef CONFIG_MAC80211_HT_DEBUG 565 if (net_ratelimit()) 566 printk(KERN_WARNING "%s: Not enough memory, " 567 "dropping start BA session", sdata->name); 568 #endif 569 return; 570 } 571 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 572 memcpy(&ra_tid->ra, ra, ETH_ALEN); 573 ra_tid->tid = tid; 574 575 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; 576 skb_queue_tail(&sdata->skb_queue, skb); 577 ieee80211_queue_work(&local->hw, &sdata->work); 578 } 579 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 580 581 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 582 enum ieee80211_back_parties initiator, 583 bool tx) 584 { 585 int ret; 586 587 mutex_lock(&sta->ampdu_mlme.mtx); 588 589 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx); 590 591 mutex_unlock(&sta->ampdu_mlme.mtx); 592 593 return ret; 594 } 595 596 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 597 { 598 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 599 struct ieee80211_sub_if_data *sdata = sta->sdata; 600 struct ieee80211_local *local = sdata->local; 601 struct tid_ampdu_tx *tid_tx; 602 int ret = 0; 603 604 trace_api_stop_tx_ba_session(pubsta, tid); 605 606 if (!local->ops->ampdu_action) 607 return -EINVAL; 608 609 if (tid >= STA_TID_NUM) 610 return -EINVAL; 611 612 spin_lock_bh(&sta->lock); 613 tid_tx = sta->ampdu_mlme.tid_tx[tid]; 614 615 if (!tid_tx) { 616 ret = -ENOENT; 617 goto unlock; 618 } 619 620 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 621 /* already in progress stopping it */ 622 ret = 0; 623 goto unlock; 624 } 625 626 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 627 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 628 629 unlock: 630 spin_unlock_bh(&sta->lock); 631 return ret; 632 } 633 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 634 635 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) 636 { 637 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 638 struct ieee80211_local *local = sdata->local; 639 struct sta_info *sta; 640 struct tid_ampdu_tx *tid_tx; 641 642 trace_api_stop_tx_ba_cb(sdata, ra, tid); 643 644 if (tid >= STA_TID_NUM) { 645 #ifdef CONFIG_MAC80211_HT_DEBUG 646 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 647 tid, STA_TID_NUM); 648 #endif 649 return; 650 } 651 652 #ifdef CONFIG_MAC80211_HT_DEBUG 653 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n", 654 ra, tid); 655 #endif /* CONFIG_MAC80211_HT_DEBUG */ 656 657 mutex_lock(&local->sta_mtx); 658 659 sta = sta_info_get(sdata, ra); 660 if (!sta) { 661 #ifdef CONFIG_MAC80211_HT_DEBUG 662 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 663 #endif 664 goto unlock; 665 } 666 667 mutex_lock(&sta->ampdu_mlme.mtx); 668 spin_lock_bh(&sta->lock); 669 tid_tx = sta->ampdu_mlme.tid_tx[tid]; 670 671 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 672 #ifdef CONFIG_MAC80211_HT_DEBUG 673 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); 674 #endif 675 goto unlock_sta; 676 } 677 678 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 679 ieee80211_send_delba(sta->sdata, ra, tid, 680 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 681 682 /* 683 * When we get here, the TX path will not be lockless any more wrt. 684 * aggregation, since the OPERATIONAL bit has long been cleared. 685 * Thus it will block on getting the lock, if it occurs. So if we 686 * stop the queue now, we will not get any more packets, and any 687 * that might be being processed will wait for us here, thereby 688 * guaranteeing that no packets go to the tid_tx pending queue any 689 * more. 690 */ 691 692 ieee80211_agg_splice_packets(local, tid_tx, tid); 693 694 /* future packets must not find the tid_tx struct any more */ 695 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL); 696 697 ieee80211_agg_splice_finish(local, tid); 698 699 call_rcu(&tid_tx->rcu_head, kfree_tid_tx); 700 701 unlock_sta: 702 spin_unlock_bh(&sta->lock); 703 mutex_unlock(&sta->ampdu_mlme.mtx); 704 unlock: 705 mutex_unlock(&local->sta_mtx); 706 } 707 708 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 709 const u8 *ra, u16 tid) 710 { 711 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 712 struct ieee80211_local *local = sdata->local; 713 struct ieee80211_ra_tid *ra_tid; 714 struct sk_buff *skb = dev_alloc_skb(0); 715 716 if (unlikely(!skb)) { 717 #ifdef CONFIG_MAC80211_HT_DEBUG 718 if (net_ratelimit()) 719 printk(KERN_WARNING "%s: Not enough memory, " 720 "dropping stop BA session", sdata->name); 721 #endif 722 return; 723 } 724 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 725 memcpy(&ra_tid->ra, ra, ETH_ALEN); 726 ra_tid->tid = tid; 727 728 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; 729 skb_queue_tail(&sdata->skb_queue, skb); 730 ieee80211_queue_work(&local->hw, &sdata->work); 731 } 732 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 733 734 735 void ieee80211_process_addba_resp(struct ieee80211_local *local, 736 struct sta_info *sta, 737 struct ieee80211_mgmt *mgmt, 738 size_t len) 739 { 740 struct tid_ampdu_tx *tid_tx; 741 u16 capab, tid; 742 743 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 744 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 745 746 mutex_lock(&sta->ampdu_mlme.mtx); 747 748 tid_tx = sta->ampdu_mlme.tid_tx[tid]; 749 if (!tid_tx) 750 goto out; 751 752 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 753 #ifdef CONFIG_MAC80211_HT_DEBUG 754 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid); 755 #endif 756 goto out; 757 } 758 759 del_timer(&tid_tx->addba_resp_timer); 760 761 #ifdef CONFIG_MAC80211_HT_DEBUG 762 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid); 763 #endif 764 765 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 766 == WLAN_STATUS_SUCCESS) { 767 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 768 &tid_tx->state)) { 769 /* ignore duplicate response */ 770 goto out; 771 } 772 773 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 774 ieee80211_agg_tx_operational(local, sta, tid); 775 776 sta->ampdu_mlme.addba_req_num[tid] = 0; 777 } else { 778 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 779 true); 780 } 781 782 out: 783 mutex_unlock(&sta->ampdu_mlme.mtx); 784 } 785