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 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 140 struct tid_ampdu_tx *tid_tx) 141 { 142 lockdep_assert_held(&sta->ampdu_mlme.mtx); 143 lockdep_assert_held(&sta->lock); 144 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], 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; 153 int ret; 154 155 lockdep_assert_held(&sta->ampdu_mlme.mtx); 156 157 spin_lock_bh(&sta->lock); 158 159 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 160 if (!tid_tx) { 161 spin_unlock_bh(&sta->lock); 162 return -ENOENT; 163 } 164 165 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 166 /* not even started yet! */ 167 ieee80211_assign_tid_tx(sta, tid, NULL); 168 spin_unlock_bh(&sta->lock); 169 kfree_rcu(tid_tx, rcu_head); 170 return 0; 171 } 172 173 spin_unlock_bh(&sta->lock); 174 175 #ifdef CONFIG_MAC80211_HT_DEBUG 176 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", 177 sta->sta.addr, tid); 178 #endif /* CONFIG_MAC80211_HT_DEBUG */ 179 180 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 181 182 del_timer_sync(&tid_tx->addba_resp_timer); 183 184 /* 185 * After this packets are no longer handed right through 186 * to the driver but are put onto tid_tx->pending instead, 187 * with locking to ensure proper access. 188 */ 189 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 190 191 tid_tx->stop_initiator = initiator; 192 tid_tx->tx_stop = tx; 193 194 ret = drv_ampdu_action(local, sta->sdata, 195 IEEE80211_AMPDU_TX_STOP, 196 &sta->sta, tid, NULL, 0); 197 198 /* HW shall not deny going back to legacy */ 199 if (WARN_ON(ret)) { 200 /* 201 * We may have pending packets get stuck in this case... 202 * Not bothering with a workaround for now. 203 */ 204 } 205 206 return ret; 207 } 208 209 /* 210 * After sending add Block Ack request we activated a timer until 211 * add Block Ack response will arrive from the recipient. 212 * If this timer expires sta_addba_resp_timer_expired will be executed. 213 */ 214 static void sta_addba_resp_timer_expired(unsigned long data) 215 { 216 /* not an elegant detour, but there is no choice as the timer passes 217 * only one argument, and both sta_info and TID are needed, so init 218 * flow in sta_info_create gives the TID as data, while the timer_to_id 219 * array gives the sta through container_of */ 220 u16 tid = *(u8 *)data; 221 struct sta_info *sta = container_of((void *)data, 222 struct sta_info, timer_to_tid[tid]); 223 struct tid_ampdu_tx *tid_tx; 224 225 /* check if the TID waits for addBA response */ 226 rcu_read_lock(); 227 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 228 if (!tid_tx || 229 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 230 rcu_read_unlock(); 231 #ifdef CONFIG_MAC80211_HT_DEBUG 232 printk(KERN_DEBUG "timer expired on tid %d but we are not " 233 "(or no longer) expecting addBA response there\n", 234 tid); 235 #endif 236 return; 237 } 238 239 #ifdef CONFIG_MAC80211_HT_DEBUG 240 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid); 241 #endif 242 243 ieee80211_stop_tx_ba_session(&sta->sta, tid); 244 rcu_read_unlock(); 245 } 246 247 static inline int ieee80211_ac_from_tid(int tid) 248 { 249 return ieee802_1d_to_ac[tid & 7]; 250 } 251 252 /* 253 * When multiple aggregation sessions on multiple stations 254 * are being created/destroyed simultaneously, we need to 255 * refcount the global queue stop caused by that in order 256 * to not get into a situation where one of the aggregation 257 * setup or teardown re-enables queues before the other is 258 * ready to handle that. 259 * 260 * These two functions take care of this issue by keeping 261 * a global "agg_queue_stop" refcount. 262 */ 263 static void __acquires(agg_queue) 264 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid) 265 { 266 int queue = ieee80211_ac_from_tid(tid); 267 268 if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1) 269 ieee80211_stop_queue_by_reason( 270 &local->hw, queue, 271 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 272 __acquire(agg_queue); 273 } 274 275 static void __releases(agg_queue) 276 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) 277 { 278 int queue = ieee80211_ac_from_tid(tid); 279 280 if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0) 281 ieee80211_wake_queue_by_reason( 282 &local->hw, queue, 283 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 284 __release(agg_queue); 285 } 286 287 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 288 { 289 struct tid_ampdu_tx *tid_tx; 290 struct ieee80211_local *local = sta->local; 291 struct ieee80211_sub_if_data *sdata = sta->sdata; 292 u16 start_seq_num; 293 int ret; 294 295 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 296 297 /* 298 * While we're asking the driver about the aggregation, 299 * stop the AC queue so that we don't have to worry 300 * about frames that came in while we were doing that, 301 * which would require us to put them to the AC pending 302 * afterwards which just makes the code more complex. 303 */ 304 ieee80211_stop_queue_agg(local, tid); 305 306 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 307 308 /* 309 * make sure no packets are being processed to get 310 * valid starting sequence number 311 */ 312 synchronize_net(); 313 314 start_seq_num = sta->tid_seq[tid] >> 4; 315 316 ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, 317 &sta->sta, tid, &start_seq_num, 0); 318 if (ret) { 319 #ifdef CONFIG_MAC80211_HT_DEBUG 320 printk(KERN_DEBUG "BA request denied - HW unavailable for" 321 " tid %d\n", tid); 322 #endif 323 spin_lock_bh(&sta->lock); 324 ieee80211_assign_tid_tx(sta, tid, NULL); 325 spin_unlock_bh(&sta->lock); 326 327 ieee80211_wake_queue_agg(local, tid); 328 kfree_rcu(tid_tx, rcu_head); 329 return; 330 } 331 332 /* we can take packets again now */ 333 ieee80211_wake_queue_agg(local, tid); 334 335 /* activate the timer for the recipient's addBA response */ 336 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 337 #ifdef CONFIG_MAC80211_HT_DEBUG 338 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid); 339 #endif 340 341 spin_lock_bh(&sta->lock); 342 sta->ampdu_mlme.addba_req_num[tid]++; 343 spin_unlock_bh(&sta->lock); 344 345 /* send AddBA request */ 346 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 347 tid_tx->dialog_token, start_seq_num, 348 local->hw.max_tx_aggregation_subframes, 349 tid_tx->timeout); 350 } 351 352 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 353 u16 timeout) 354 { 355 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 356 struct ieee80211_sub_if_data *sdata = sta->sdata; 357 struct ieee80211_local *local = sdata->local; 358 struct tid_ampdu_tx *tid_tx; 359 int ret = 0; 360 361 trace_api_start_tx_ba_session(pubsta, tid); 362 363 if (WARN_ON(!local->ops->ampdu_action)) 364 return -EINVAL; 365 366 if ((tid >= STA_TID_NUM) || 367 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) 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_flags(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 #ifdef CONFIG_MAC80211_HT_DEBUG 417 if (net_ratelimit()) 418 printk(KERN_ERR "allocate tx mlme to tid %d failed\n", 419 tid); 420 #endif 421 ret = -ENOMEM; 422 goto err_unlock_sta; 423 } 424 425 skb_queue_head_init(&tid_tx->pending); 426 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 427 428 tid_tx->timeout = timeout; 429 430 /* Tx timer */ 431 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; 432 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 433 init_timer(&tid_tx->addba_resp_timer); 434 435 /* assign a dialog token */ 436 sta->ampdu_mlme.dialog_token_allocator++; 437 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 438 439 /* 440 * Finally, assign it to the start array; the work item will 441 * collect it and move it to the normal array. 442 */ 443 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 444 445 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 446 447 /* this flow continues off the work */ 448 err_unlock_sta: 449 spin_unlock_bh(&sta->lock); 450 return ret; 451 } 452 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 453 454 /* 455 * splice packets from the STA's pending to the local pending, 456 * requires a call to ieee80211_agg_splice_finish later 457 */ 458 static void __acquires(agg_queue) 459 ieee80211_agg_splice_packets(struct ieee80211_local *local, 460 struct tid_ampdu_tx *tid_tx, u16 tid) 461 { 462 int queue = ieee80211_ac_from_tid(tid); 463 unsigned long flags; 464 465 ieee80211_stop_queue_agg(local, tid); 466 467 if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates" 468 " from the pending queue\n", tid)) 469 return; 470 471 if (!skb_queue_empty(&tid_tx->pending)) { 472 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 473 /* copy over remaining packets */ 474 skb_queue_splice_tail_init(&tid_tx->pending, 475 &local->pending[queue]); 476 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 477 } 478 } 479 480 static void __releases(agg_queue) 481 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) 482 { 483 ieee80211_wake_queue_agg(local, tid); 484 } 485 486 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 487 struct sta_info *sta, u16 tid) 488 { 489 struct tid_ampdu_tx *tid_tx; 490 491 lockdep_assert_held(&sta->ampdu_mlme.mtx); 492 493 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 494 495 #ifdef CONFIG_MAC80211_HT_DEBUG 496 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); 497 #endif 498 499 drv_ampdu_action(local, sta->sdata, 500 IEEE80211_AMPDU_TX_OPERATIONAL, 501 &sta->sta, tid, NULL, tid_tx->buf_size); 502 503 /* 504 * synchronize with TX path, while splicing the TX path 505 * should block so it won't put more packets onto pending. 506 */ 507 spin_lock_bh(&sta->lock); 508 509 ieee80211_agg_splice_packets(local, tid_tx, tid); 510 /* 511 * Now mark as operational. This will be visible 512 * in the TX path, and lets it go lock-free in 513 * the common case. 514 */ 515 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 516 ieee80211_agg_splice_finish(local, tid); 517 518 spin_unlock_bh(&sta->lock); 519 } 520 521 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) 522 { 523 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 524 struct ieee80211_local *local = sdata->local; 525 struct sta_info *sta; 526 struct tid_ampdu_tx *tid_tx; 527 528 trace_api_start_tx_ba_cb(sdata, ra, tid); 529 530 if (tid >= STA_TID_NUM) { 531 #ifdef CONFIG_MAC80211_HT_DEBUG 532 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 533 tid, STA_TID_NUM); 534 #endif 535 return; 536 } 537 538 mutex_lock(&local->sta_mtx); 539 sta = sta_info_get(sdata, ra); 540 if (!sta) { 541 mutex_unlock(&local->sta_mtx); 542 #ifdef CONFIG_MAC80211_HT_DEBUG 543 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 544 #endif 545 return; 546 } 547 548 mutex_lock(&sta->ampdu_mlme.mtx); 549 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 550 551 if (WARN_ON(!tid_tx)) { 552 #ifdef CONFIG_MAC80211_HT_DEBUG 553 printk(KERN_DEBUG "addBA was not requested!\n"); 554 #endif 555 goto unlock; 556 } 557 558 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 559 goto unlock; 560 561 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 562 ieee80211_agg_tx_operational(local, sta, tid); 563 564 unlock: 565 mutex_unlock(&sta->ampdu_mlme.mtx); 566 mutex_unlock(&local->sta_mtx); 567 } 568 569 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 570 const u8 *ra, u16 tid) 571 { 572 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 573 struct ieee80211_local *local = sdata->local; 574 struct ieee80211_ra_tid *ra_tid; 575 struct sk_buff *skb = dev_alloc_skb(0); 576 577 if (unlikely(!skb)) { 578 #ifdef CONFIG_MAC80211_HT_DEBUG 579 if (net_ratelimit()) 580 printk(KERN_WARNING "%s: Not enough memory, " 581 "dropping start BA session", sdata->name); 582 #endif 583 return; 584 } 585 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 586 memcpy(&ra_tid->ra, ra, ETH_ALEN); 587 ra_tid->tid = tid; 588 589 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; 590 skb_queue_tail(&sdata->skb_queue, skb); 591 ieee80211_queue_work(&local->hw, &sdata->work); 592 } 593 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 594 595 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 596 enum ieee80211_back_parties initiator, 597 bool tx) 598 { 599 int ret; 600 601 mutex_lock(&sta->ampdu_mlme.mtx); 602 603 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx); 604 605 mutex_unlock(&sta->ampdu_mlme.mtx); 606 607 return ret; 608 } 609 610 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 611 { 612 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 613 struct ieee80211_sub_if_data *sdata = sta->sdata; 614 struct ieee80211_local *local = sdata->local; 615 struct tid_ampdu_tx *tid_tx; 616 int ret = 0; 617 618 trace_api_stop_tx_ba_session(pubsta, tid); 619 620 if (!local->ops->ampdu_action) 621 return -EINVAL; 622 623 if (tid >= STA_TID_NUM) 624 return -EINVAL; 625 626 spin_lock_bh(&sta->lock); 627 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 628 629 if (!tid_tx) { 630 ret = -ENOENT; 631 goto unlock; 632 } 633 634 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 635 /* already in progress stopping it */ 636 ret = 0; 637 goto unlock; 638 } 639 640 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 641 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 642 643 unlock: 644 spin_unlock_bh(&sta->lock); 645 return ret; 646 } 647 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 648 649 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) 650 { 651 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 652 struct ieee80211_local *local = sdata->local; 653 struct sta_info *sta; 654 struct tid_ampdu_tx *tid_tx; 655 656 trace_api_stop_tx_ba_cb(sdata, ra, tid); 657 658 if (tid >= STA_TID_NUM) { 659 #ifdef CONFIG_MAC80211_HT_DEBUG 660 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 661 tid, STA_TID_NUM); 662 #endif 663 return; 664 } 665 666 #ifdef CONFIG_MAC80211_HT_DEBUG 667 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n", 668 ra, tid); 669 #endif /* CONFIG_MAC80211_HT_DEBUG */ 670 671 mutex_lock(&local->sta_mtx); 672 673 sta = sta_info_get(sdata, ra); 674 if (!sta) { 675 #ifdef CONFIG_MAC80211_HT_DEBUG 676 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 677 #endif 678 goto unlock; 679 } 680 681 mutex_lock(&sta->ampdu_mlme.mtx); 682 spin_lock_bh(&sta->lock); 683 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 684 685 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 686 #ifdef CONFIG_MAC80211_HT_DEBUG 687 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); 688 #endif 689 goto unlock_sta; 690 } 691 692 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 693 ieee80211_send_delba(sta->sdata, ra, tid, 694 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 695 696 /* 697 * When we get here, the TX path will not be lockless any more wrt. 698 * aggregation, since the OPERATIONAL bit has long been cleared. 699 * Thus it will block on getting the lock, if it occurs. So if we 700 * stop the queue now, we will not get any more packets, and any 701 * that might be being processed will wait for us here, thereby 702 * guaranteeing that no packets go to the tid_tx pending queue any 703 * more. 704 */ 705 706 ieee80211_agg_splice_packets(local, tid_tx, tid); 707 708 /* future packets must not find the tid_tx struct any more */ 709 ieee80211_assign_tid_tx(sta, tid, NULL); 710 711 ieee80211_agg_splice_finish(local, tid); 712 713 kfree_rcu(tid_tx, rcu_head); 714 715 unlock_sta: 716 spin_unlock_bh(&sta->lock); 717 mutex_unlock(&sta->ampdu_mlme.mtx); 718 unlock: 719 mutex_unlock(&local->sta_mtx); 720 } 721 722 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 723 const u8 *ra, u16 tid) 724 { 725 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 726 struct ieee80211_local *local = sdata->local; 727 struct ieee80211_ra_tid *ra_tid; 728 struct sk_buff *skb = dev_alloc_skb(0); 729 730 if (unlikely(!skb)) { 731 #ifdef CONFIG_MAC80211_HT_DEBUG 732 if (net_ratelimit()) 733 printk(KERN_WARNING "%s: Not enough memory, " 734 "dropping stop BA session", sdata->name); 735 #endif 736 return; 737 } 738 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 739 memcpy(&ra_tid->ra, ra, ETH_ALEN); 740 ra_tid->tid = tid; 741 742 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; 743 skb_queue_tail(&sdata->skb_queue, skb); 744 ieee80211_queue_work(&local->hw, &sdata->work); 745 } 746 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 747 748 749 void ieee80211_process_addba_resp(struct ieee80211_local *local, 750 struct sta_info *sta, 751 struct ieee80211_mgmt *mgmt, 752 size_t len) 753 { 754 struct tid_ampdu_tx *tid_tx; 755 u16 capab, tid; 756 u8 buf_size; 757 758 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 759 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 760 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 761 762 mutex_lock(&sta->ampdu_mlme.mtx); 763 764 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 765 if (!tid_tx) 766 goto out; 767 768 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 769 #ifdef CONFIG_MAC80211_HT_DEBUG 770 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid); 771 #endif 772 goto out; 773 } 774 775 del_timer(&tid_tx->addba_resp_timer); 776 777 #ifdef CONFIG_MAC80211_HT_DEBUG 778 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid); 779 #endif 780 781 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 782 == WLAN_STATUS_SUCCESS) { 783 /* 784 * IEEE 802.11-2007 7.3.1.14: 785 * In an ADDBA Response frame, when the Status Code field 786 * is set to 0, the Buffer Size subfield is set to a value 787 * of at least 1. 788 */ 789 if (!buf_size) 790 goto out; 791 792 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 793 &tid_tx->state)) { 794 /* ignore duplicate response */ 795 goto out; 796 } 797 798 tid_tx->buf_size = buf_size; 799 800 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 801 ieee80211_agg_tx_operational(local, sta, tid); 802 803 sta->ampdu_mlme.addba_req_num[tid] = 0; 804 } else { 805 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 806 true); 807 } 808 809 out: 810 mutex_unlock(&sta->ampdu_mlme.mtx); 811 } 812