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 * Copyright(c) 2015-2017 Intel Deutschland GmbH 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License version 2 as 14 * published by the Free Software Foundation. 15 */ 16 17 #include <linux/ieee80211.h> 18 #include <linux/slab.h> 19 #include <linux/export.h> 20 #include <net/mac80211.h> 21 #include "ieee80211_i.h" 22 #include "driver-ops.h" 23 #include "wme.h" 24 25 /** 26 * DOC: TX A-MPDU aggregation 27 * 28 * Aggregation on the TX side requires setting the hardware flag 29 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed 30 * packets with a flag indicating A-MPDU aggregation. The driver 31 * or device is responsible for actually aggregating the frames, 32 * as well as deciding how many and which to aggregate. 33 * 34 * When TX aggregation is started by some subsystem (usually the rate 35 * control algorithm would be appropriate) by calling the 36 * ieee80211_start_tx_ba_session() function, the driver will be 37 * notified via its @ampdu_action function, with the 38 * %IEEE80211_AMPDU_TX_START action. 39 * 40 * In response to that, the driver is later required to call the 41 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really 42 * start the aggregation session after the peer has also responded. 43 * If the peer responds negatively, the session will be stopped 44 * again right away. Note that it is possible for the aggregation 45 * session to be stopped before the driver has indicated that it 46 * is done setting it up, in which case it must not indicate the 47 * setup completion. 48 * 49 * Also note that, since we also need to wait for a response from 50 * the peer, the driver is notified of the completion of the 51 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the 52 * @ampdu_action callback. 53 * 54 * Similarly, when the aggregation session is stopped by the peer 55 * or something calling ieee80211_stop_tx_ba_session(), the driver's 56 * @ampdu_action function will be called with the action 57 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, 58 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). 59 * Note that the sta can get destroyed before the BA tear down is 60 * complete. 61 */ 62 63 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 64 const u8 *da, u16 tid, 65 u8 dialog_token, u16 start_seq_num, 66 u16 agg_size, u16 timeout) 67 { 68 struct ieee80211_local *local = sdata->local; 69 struct sk_buff *skb; 70 struct ieee80211_mgmt *mgmt; 71 u16 capab; 72 73 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 74 75 if (!skb) 76 return; 77 78 skb_reserve(skb, local->hw.extra_tx_headroom); 79 mgmt = skb_put_zero(skb, 24); 80 memcpy(mgmt->da, da, ETH_ALEN); 81 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 82 if (sdata->vif.type == NL80211_IFTYPE_AP || 83 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 84 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 85 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 86 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 87 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 88 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 89 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 90 91 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 92 IEEE80211_STYPE_ACTION); 93 94 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 95 96 mgmt->u.action.category = WLAN_CATEGORY_BACK; 97 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 98 99 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 100 capab = (u16)(1 << 0); /* bit 0 A-MSDU support */ 101 capab |= (u16)(1 << 1); /* bit 1 aggregation policy */ 102 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 103 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 104 105 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 106 107 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 108 mgmt->u.action.u.addba_req.start_seq_num = 109 cpu_to_le16(start_seq_num << 4); 110 111 ieee80211_tx_skb(sdata, skb); 112 } 113 114 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) 115 { 116 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 117 struct ieee80211_local *local = sdata->local; 118 struct sk_buff *skb; 119 struct ieee80211_bar *bar; 120 u16 bar_control = 0; 121 122 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); 123 if (!skb) 124 return; 125 126 skb_reserve(skb, local->hw.extra_tx_headroom); 127 bar = skb_put_zero(skb, sizeof(*bar)); 128 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 129 IEEE80211_STYPE_BACK_REQ); 130 memcpy(bar->ra, ra, ETH_ALEN); 131 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 132 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 133 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 134 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 135 bar->control = cpu_to_le16(bar_control); 136 bar->start_seq_num = cpu_to_le16(ssn); 137 138 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | 139 IEEE80211_TX_CTL_REQ_TX_STATUS; 140 ieee80211_tx_skb_tid(sdata, skb, tid); 141 } 142 EXPORT_SYMBOL(ieee80211_send_bar); 143 144 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 145 struct tid_ampdu_tx *tid_tx) 146 { 147 lockdep_assert_held(&sta->ampdu_mlme.mtx); 148 lockdep_assert_held(&sta->lock); 149 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 150 } 151 152 /* 153 * When multiple aggregation sessions on multiple stations 154 * are being created/destroyed simultaneously, we need to 155 * refcount the global queue stop caused by that in order 156 * to not get into a situation where one of the aggregation 157 * setup or teardown re-enables queues before the other is 158 * ready to handle that. 159 * 160 * These two functions take care of this issue by keeping 161 * a global "agg_queue_stop" refcount. 162 */ 163 static void __acquires(agg_queue) 164 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 165 { 166 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 167 168 /* we do refcounting here, so don't use the queue reason refcounting */ 169 170 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1) 171 ieee80211_stop_queue_by_reason( 172 &sdata->local->hw, queue, 173 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 174 false); 175 __acquire(agg_queue); 176 } 177 178 static void __releases(agg_queue) 179 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 180 { 181 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 182 183 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0) 184 ieee80211_wake_queue_by_reason( 185 &sdata->local->hw, queue, 186 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 187 false); 188 __release(agg_queue); 189 } 190 191 static void 192 ieee80211_agg_stop_txq(struct sta_info *sta, int tid) 193 { 194 struct ieee80211_txq *txq = sta->sta.txq[tid]; 195 struct ieee80211_sub_if_data *sdata; 196 struct fq *fq; 197 struct txq_info *txqi; 198 199 if (!txq) 200 return; 201 202 txqi = to_txq_info(txq); 203 sdata = vif_to_sdata(txq->vif); 204 fq = &sdata->local->fq; 205 206 /* Lock here to protect against further seqno updates on dequeue */ 207 spin_lock_bh(&fq->lock); 208 set_bit(IEEE80211_TXQ_STOP, &txqi->flags); 209 spin_unlock_bh(&fq->lock); 210 } 211 212 static void 213 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) 214 { 215 struct ieee80211_txq *txq = sta->sta.txq[tid]; 216 struct txq_info *txqi; 217 218 if (!txq) 219 return; 220 221 txqi = to_txq_info(txq); 222 223 if (enable) 224 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 225 else 226 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 227 228 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); 229 local_bh_disable(); 230 rcu_read_lock(); 231 drv_wake_tx_queue(sta->sdata->local, txqi); 232 rcu_read_unlock(); 233 local_bh_enable(); 234 } 235 236 /* 237 * splice packets from the STA's pending to the local pending, 238 * requires a call to ieee80211_agg_splice_finish later 239 */ 240 static void __acquires(agg_queue) 241 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata, 242 struct tid_ampdu_tx *tid_tx, u16 tid) 243 { 244 struct ieee80211_local *local = sdata->local; 245 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 246 unsigned long flags; 247 248 ieee80211_stop_queue_agg(sdata, tid); 249 250 if (WARN(!tid_tx, 251 "TID %d gone but expected when splicing aggregates from the pending queue\n", 252 tid)) 253 return; 254 255 if (!skb_queue_empty(&tid_tx->pending)) { 256 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 257 /* copy over remaining packets */ 258 skb_queue_splice_tail_init(&tid_tx->pending, 259 &local->pending[queue]); 260 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 261 } 262 } 263 264 static void __releases(agg_queue) 265 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid) 266 { 267 ieee80211_wake_queue_agg(sdata, tid); 268 } 269 270 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid) 271 { 272 struct tid_ampdu_tx *tid_tx; 273 274 lockdep_assert_held(&sta->ampdu_mlme.mtx); 275 lockdep_assert_held(&sta->lock); 276 277 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 278 279 /* 280 * When we get here, the TX path will not be lockless any more wrt. 281 * aggregation, since the OPERATIONAL bit has long been cleared. 282 * Thus it will block on getting the lock, if it occurs. So if we 283 * stop the queue now, we will not get any more packets, and any 284 * that might be being processed will wait for us here, thereby 285 * guaranteeing that no packets go to the tid_tx pending queue any 286 * more. 287 */ 288 289 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 290 291 /* future packets must not find the tid_tx struct any more */ 292 ieee80211_assign_tid_tx(sta, tid, NULL); 293 294 ieee80211_agg_splice_finish(sta->sdata, tid); 295 ieee80211_agg_start_txq(sta, tid, false); 296 297 kfree_rcu(tid_tx, rcu_head); 298 } 299 300 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 301 enum ieee80211_agg_stop_reason reason) 302 { 303 struct ieee80211_local *local = sta->local; 304 struct tid_ampdu_tx *tid_tx; 305 struct ieee80211_ampdu_params params = { 306 .sta = &sta->sta, 307 .tid = tid, 308 .buf_size = 0, 309 .amsdu = false, 310 .timeout = 0, 311 .ssn = 0, 312 }; 313 int ret; 314 315 lockdep_assert_held(&sta->ampdu_mlme.mtx); 316 317 switch (reason) { 318 case AGG_STOP_DECLINED: 319 case AGG_STOP_LOCAL_REQUEST: 320 case AGG_STOP_PEER_REQUEST: 321 params.action = IEEE80211_AMPDU_TX_STOP_CONT; 322 break; 323 case AGG_STOP_DESTROY_STA: 324 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH; 325 break; 326 default: 327 WARN_ON_ONCE(1); 328 return -EINVAL; 329 } 330 331 spin_lock_bh(&sta->lock); 332 333 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 334 if (!tid_tx) { 335 spin_unlock_bh(&sta->lock); 336 return -ENOENT; 337 } 338 339 /* 340 * if we're already stopping ignore any new requests to stop 341 * unless we're destroying it in which case notify the driver 342 */ 343 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 344 spin_unlock_bh(&sta->lock); 345 if (reason != AGG_STOP_DESTROY_STA) 346 return -EALREADY; 347 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT; 348 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 349 WARN_ON_ONCE(ret); 350 return 0; 351 } 352 353 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 354 /* not even started yet! */ 355 ieee80211_assign_tid_tx(sta, tid, NULL); 356 spin_unlock_bh(&sta->lock); 357 kfree_rcu(tid_tx, rcu_head); 358 return 0; 359 } 360 361 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 362 363 spin_unlock_bh(&sta->lock); 364 365 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n", 366 sta->sta.addr, tid); 367 368 del_timer_sync(&tid_tx->addba_resp_timer); 369 del_timer_sync(&tid_tx->session_timer); 370 371 /* 372 * After this packets are no longer handed right through 373 * to the driver but are put onto tid_tx->pending instead, 374 * with locking to ensure proper access. 375 */ 376 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 377 378 /* 379 * There might be a few packets being processed right now (on 380 * another CPU) that have already gotten past the aggregation 381 * check when it was still OPERATIONAL and consequently have 382 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might 383 * call into the driver at the same time or even before the 384 * TX paths calls into it, which could confuse the driver. 385 * 386 * Wait for all currently running TX paths to finish before 387 * telling the driver. New packets will not go through since 388 * the aggregation session is no longer OPERATIONAL. 389 */ 390 synchronize_net(); 391 392 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ? 393 WLAN_BACK_RECIPIENT : 394 WLAN_BACK_INITIATOR; 395 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; 396 397 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 398 399 /* HW shall not deny going back to legacy */ 400 if (WARN_ON(ret)) { 401 /* 402 * We may have pending packets get stuck in this case... 403 * Not bothering with a workaround for now. 404 */ 405 } 406 407 /* 408 * In the case of AGG_STOP_DESTROY_STA, the driver won't 409 * necessarily call ieee80211_stop_tx_ba_cb(), so this may 410 * seem like we can leave the tid_tx data pending forever. 411 * This is true, in a way, but "forever" is only until the 412 * station struct is actually destroyed. In the meantime, 413 * leaving it around ensures that we don't transmit packets 414 * to the driver on this TID which might confuse it. 415 */ 416 417 return 0; 418 } 419 420 /* 421 * After sending add Block Ack request we activated a timer until 422 * add Block Ack response will arrive from the recipient. 423 * If this timer expires sta_addba_resp_timer_expired will be executed. 424 */ 425 static void sta_addba_resp_timer_expired(unsigned long data) 426 { 427 /* not an elegant detour, but there is no choice as the timer passes 428 * only one argument, and both sta_info and TID are needed, so init 429 * flow in sta_info_create gives the TID as data, while the timer_to_id 430 * array gives the sta through container_of */ 431 u16 tid = *(u8 *)data; 432 struct sta_info *sta = container_of((void *)data, 433 struct sta_info, timer_to_tid[tid]); 434 struct tid_ampdu_tx *tid_tx; 435 436 /* check if the TID waits for addBA response */ 437 rcu_read_lock(); 438 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 439 if (!tid_tx || 440 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 441 rcu_read_unlock(); 442 ht_dbg(sta->sdata, 443 "timer expired on %pM tid %d not expecting addBA response\n", 444 sta->sta.addr, tid); 445 return; 446 } 447 448 ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n", 449 sta->sta.addr, tid); 450 451 ieee80211_stop_tx_ba_session(&sta->sta, tid); 452 rcu_read_unlock(); 453 } 454 455 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 456 { 457 struct tid_ampdu_tx *tid_tx; 458 struct ieee80211_local *local = sta->local; 459 struct ieee80211_sub_if_data *sdata = sta->sdata; 460 struct ieee80211_ampdu_params params = { 461 .sta = &sta->sta, 462 .action = IEEE80211_AMPDU_TX_START, 463 .tid = tid, 464 .buf_size = 0, 465 .amsdu = false, 466 .timeout = 0, 467 }; 468 int ret; 469 470 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 471 472 /* 473 * Start queuing up packets for this aggregation session. 474 * We're going to release them once the driver is OK with 475 * that. 476 */ 477 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 478 479 ieee80211_agg_stop_txq(sta, tid); 480 481 /* 482 * Make sure no packets are being processed. This ensures that 483 * we have a valid starting sequence number and that in-flight 484 * packets have been flushed out and no packets for this TID 485 * will go into the driver during the ampdu_action call. 486 */ 487 synchronize_net(); 488 489 params.ssn = sta->tid_seq[tid] >> 4; 490 ret = drv_ampdu_action(local, sdata, ¶ms); 491 if (ret) { 492 ht_dbg(sdata, 493 "BA request denied - HW unavailable for %pM tid %d\n", 494 sta->sta.addr, tid); 495 spin_lock_bh(&sta->lock); 496 ieee80211_agg_splice_packets(sdata, tid_tx, tid); 497 ieee80211_assign_tid_tx(sta, tid, NULL); 498 ieee80211_agg_splice_finish(sdata, tid); 499 spin_unlock_bh(&sta->lock); 500 501 ieee80211_agg_start_txq(sta, tid, false); 502 503 kfree_rcu(tid_tx, rcu_head); 504 return; 505 } 506 507 /* activate the timer for the recipient's addBA response */ 508 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 509 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n", 510 sta->sta.addr, tid); 511 512 spin_lock_bh(&sta->lock); 513 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies; 514 sta->ampdu_mlme.addba_req_num[tid]++; 515 spin_unlock_bh(&sta->lock); 516 517 /* send AddBA request */ 518 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 519 tid_tx->dialog_token, params.ssn, 520 IEEE80211_MAX_AMPDU_BUF, 521 tid_tx->timeout); 522 } 523 524 /* 525 * After accepting the AddBA Response we activated a timer, 526 * resetting it after each frame that we send. 527 */ 528 static void sta_tx_agg_session_timer_expired(unsigned long data) 529 { 530 /* not an elegant detour, but there is no choice as the timer passes 531 * only one argument, and various sta_info are needed here, so init 532 * flow in sta_info_create gives the TID as data, while the timer_to_id 533 * array gives the sta through container_of */ 534 u8 *ptid = (u8 *)data; 535 u8 *timer_to_id = ptid - *ptid; 536 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 537 timer_to_tid[0]); 538 struct tid_ampdu_tx *tid_tx; 539 unsigned long timeout; 540 541 rcu_read_lock(); 542 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]); 543 if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 544 rcu_read_unlock(); 545 return; 546 } 547 548 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); 549 if (time_is_after_jiffies(timeout)) { 550 mod_timer(&tid_tx->session_timer, timeout); 551 rcu_read_unlock(); 552 return; 553 } 554 555 rcu_read_unlock(); 556 557 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n", 558 sta->sta.addr, (u16)*ptid); 559 560 ieee80211_stop_tx_ba_session(&sta->sta, *ptid); 561 } 562 563 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 564 u16 timeout) 565 { 566 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 567 struct ieee80211_sub_if_data *sdata = sta->sdata; 568 struct ieee80211_local *local = sdata->local; 569 struct tid_ampdu_tx *tid_tx; 570 int ret = 0; 571 572 trace_api_start_tx_ba_session(pubsta, tid); 573 574 if (WARN(sta->reserved_tid == tid, 575 "Requested to start BA session on reserved tid=%d", tid)) 576 return -EINVAL; 577 578 if (!pubsta->ht_cap.ht_supported) 579 return -EINVAL; 580 581 if (WARN_ON_ONCE(!local->ops->ampdu_action)) 582 return -EINVAL; 583 584 if ((tid >= IEEE80211_NUM_TIDS) || 585 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) || 586 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) 587 return -EINVAL; 588 589 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID)) 590 return -EINVAL; 591 592 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n", 593 pubsta->addr, tid); 594 595 if (sdata->vif.type != NL80211_IFTYPE_STATION && 596 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 597 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 598 sdata->vif.type != NL80211_IFTYPE_AP && 599 sdata->vif.type != NL80211_IFTYPE_ADHOC) 600 return -EINVAL; 601 602 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 603 ht_dbg(sdata, 604 "BA sessions blocked - Denying BA session request %pM tid %d\n", 605 sta->sta.addr, tid); 606 return -EINVAL; 607 } 608 609 /* 610 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 611 * member of an IBSS, and has no other existing Block Ack agreement 612 * with the recipient STA, then the initiating STA shall transmit a 613 * Probe Request frame to the recipient STA and shall not transmit an 614 * ADDBA Request frame unless it receives a Probe Response frame 615 * from the recipient within dot11ADDBAFailureTimeout. 616 * 617 * The probe request mechanism for ADDBA is currently not implemented, 618 * but we only build up Block Ack session with HT STAs. This information 619 * is set when we receive a bss info from a probe response or a beacon. 620 */ 621 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 622 !sta->sta.ht_cap.ht_supported) { 623 ht_dbg(sdata, 624 "BA request denied - IBSS STA %pM does not advertise HT support\n", 625 pubsta->addr); 626 return -EINVAL; 627 } 628 629 spin_lock_bh(&sta->lock); 630 631 /* we have tried too many times, receiver does not want A-MPDU */ 632 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 633 ret = -EBUSY; 634 goto err_unlock_sta; 635 } 636 637 /* 638 * if we have tried more than HT_AGG_BURST_RETRIES times we 639 * will spread our requests in time to avoid stalling connection 640 * for too long 641 */ 642 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && 643 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + 644 HT_AGG_RETRIES_PERIOD)) { 645 ht_dbg(sdata, 646 "BA request denied - %d failed requests on %pM tid %u\n", 647 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid); 648 ret = -EBUSY; 649 goto err_unlock_sta; 650 } 651 652 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 653 /* check if the TID is not in aggregation flow already */ 654 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 655 ht_dbg(sdata, 656 "BA request denied - session is not idle on %pM tid %u\n", 657 sta->sta.addr, tid); 658 ret = -EAGAIN; 659 goto err_unlock_sta; 660 } 661 662 /* prepare A-MPDU MLME for Tx aggregation */ 663 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 664 if (!tid_tx) { 665 ret = -ENOMEM; 666 goto err_unlock_sta; 667 } 668 669 skb_queue_head_init(&tid_tx->pending); 670 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 671 672 tid_tx->timeout = timeout; 673 674 /* response timer */ 675 setup_timer(&tid_tx->addba_resp_timer, 676 sta_addba_resp_timer_expired, 677 (unsigned long)&sta->timer_to_tid[tid]); 678 679 /* tx timer */ 680 setup_deferrable_timer(&tid_tx->session_timer, 681 sta_tx_agg_session_timer_expired, 682 (unsigned long)&sta->timer_to_tid[tid]); 683 684 /* assign a dialog token */ 685 sta->ampdu_mlme.dialog_token_allocator++; 686 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 687 688 /* 689 * Finally, assign it to the start array; the work item will 690 * collect it and move it to the normal array. 691 */ 692 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 693 694 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 695 696 /* this flow continues off the work */ 697 err_unlock_sta: 698 spin_unlock_bh(&sta->lock); 699 return ret; 700 } 701 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 702 703 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 704 struct sta_info *sta, u16 tid) 705 { 706 struct tid_ampdu_tx *tid_tx; 707 struct ieee80211_ampdu_params params = { 708 .sta = &sta->sta, 709 .action = IEEE80211_AMPDU_TX_OPERATIONAL, 710 .tid = tid, 711 .timeout = 0, 712 .ssn = 0, 713 }; 714 715 lockdep_assert_held(&sta->ampdu_mlme.mtx); 716 717 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 718 params.buf_size = tid_tx->buf_size; 719 params.amsdu = tid_tx->amsdu; 720 721 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", 722 sta->sta.addr, tid); 723 724 drv_ampdu_action(local, sta->sdata, ¶ms); 725 726 /* 727 * synchronize with TX path, while splicing the TX path 728 * should block so it won't put more packets onto pending. 729 */ 730 spin_lock_bh(&sta->lock); 731 732 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 733 /* 734 * Now mark as operational. This will be visible 735 * in the TX path, and lets it go lock-free in 736 * the common case. 737 */ 738 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 739 ieee80211_agg_splice_finish(sta->sdata, tid); 740 741 spin_unlock_bh(&sta->lock); 742 743 ieee80211_agg_start_txq(sta, tid, true); 744 } 745 746 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, 747 struct tid_ampdu_tx *tid_tx) 748 { 749 struct ieee80211_sub_if_data *sdata = sta->sdata; 750 struct ieee80211_local *local = sdata->local; 751 752 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 753 return; 754 755 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 756 ieee80211_agg_tx_operational(local, sta, tid); 757 } 758 759 static struct tid_ampdu_tx * 760 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, 761 const u8 *ra, u16 tid, struct sta_info **sta) 762 { 763 struct tid_ampdu_tx *tid_tx; 764 765 if (tid >= IEEE80211_NUM_TIDS) { 766 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", 767 tid, IEEE80211_NUM_TIDS); 768 return NULL; 769 } 770 771 *sta = sta_info_get_bss(sdata, ra); 772 if (!*sta) { 773 ht_dbg(sdata, "Could not find station: %pM\n", ra); 774 return NULL; 775 } 776 777 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); 778 779 if (WARN_ON(!tid_tx)) 780 ht_dbg(sdata, "addBA was not requested!\n"); 781 782 return tid_tx; 783 } 784 785 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 786 const u8 *ra, u16 tid) 787 { 788 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 789 struct ieee80211_local *local = sdata->local; 790 struct sta_info *sta; 791 struct tid_ampdu_tx *tid_tx; 792 793 trace_api_start_tx_ba_cb(sdata, ra, tid); 794 795 rcu_read_lock(); 796 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 797 if (!tid_tx) 798 goto out; 799 800 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); 801 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 802 out: 803 rcu_read_unlock(); 804 } 805 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 806 807 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 808 enum ieee80211_agg_stop_reason reason) 809 { 810 int ret; 811 812 mutex_lock(&sta->ampdu_mlme.mtx); 813 814 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); 815 816 mutex_unlock(&sta->ampdu_mlme.mtx); 817 818 return ret; 819 } 820 821 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 822 { 823 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 824 struct ieee80211_sub_if_data *sdata = sta->sdata; 825 struct ieee80211_local *local = sdata->local; 826 struct tid_ampdu_tx *tid_tx; 827 int ret = 0; 828 829 trace_api_stop_tx_ba_session(pubsta, tid); 830 831 if (!local->ops->ampdu_action) 832 return -EINVAL; 833 834 if (tid >= IEEE80211_NUM_TIDS) 835 return -EINVAL; 836 837 spin_lock_bh(&sta->lock); 838 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 839 840 if (!tid_tx) { 841 ret = -ENOENT; 842 goto unlock; 843 } 844 845 WARN(sta->reserved_tid == tid, 846 "Requested to stop BA session on reserved tid=%d", tid); 847 848 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 849 /* already in progress stopping it */ 850 ret = 0; 851 goto unlock; 852 } 853 854 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 855 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 856 857 unlock: 858 spin_unlock_bh(&sta->lock); 859 return ret; 860 } 861 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 862 863 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, 864 struct tid_ampdu_tx *tid_tx) 865 { 866 struct ieee80211_sub_if_data *sdata = sta->sdata; 867 bool send_delba = false; 868 869 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", 870 sta->sta.addr, tid); 871 872 spin_lock_bh(&sta->lock); 873 874 if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 875 ht_dbg(sdata, 876 "unexpected callback to A-MPDU stop for %pM tid %d\n", 877 sta->sta.addr, tid); 878 goto unlock_sta; 879 } 880 881 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 882 send_delba = true; 883 884 ieee80211_remove_tid_tx(sta, tid); 885 886 unlock_sta: 887 spin_unlock_bh(&sta->lock); 888 889 if (send_delba) 890 ieee80211_send_delba(sdata, sta->sta.addr, tid, 891 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 892 } 893 894 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 895 const u8 *ra, u16 tid) 896 { 897 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 898 struct ieee80211_local *local = sdata->local; 899 struct sta_info *sta; 900 struct tid_ampdu_tx *tid_tx; 901 902 trace_api_stop_tx_ba_cb(sdata, ra, tid); 903 904 rcu_read_lock(); 905 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 906 if (!tid_tx) 907 goto out; 908 909 set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); 910 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 911 out: 912 rcu_read_unlock(); 913 } 914 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 915 916 917 void ieee80211_process_addba_resp(struct ieee80211_local *local, 918 struct sta_info *sta, 919 struct ieee80211_mgmt *mgmt, 920 size_t len) 921 { 922 struct tid_ampdu_tx *tid_tx; 923 struct ieee80211_txq *txq; 924 u16 capab, tid; 925 u8 buf_size; 926 bool amsdu; 927 928 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 929 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK; 930 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 931 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 932 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes); 933 934 txq = sta->sta.txq[tid]; 935 if (!amsdu && txq) 936 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags); 937 938 mutex_lock(&sta->ampdu_mlme.mtx); 939 940 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 941 if (!tid_tx) 942 goto out; 943 944 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 945 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n", 946 sta->sta.addr, tid); 947 goto out; 948 } 949 950 del_timer_sync(&tid_tx->addba_resp_timer); 951 952 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", 953 sta->sta.addr, tid); 954 955 /* 956 * addba_resp_timer may have fired before we got here, and 957 * caused WANT_STOP to be set. If the stop then was already 958 * processed further, STOPPING might be set. 959 */ 960 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 961 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 962 ht_dbg(sta->sdata, 963 "got addBA resp for %pM tid %d but we already gave up\n", 964 sta->sta.addr, tid); 965 goto out; 966 } 967 968 /* 969 * IEEE 802.11-2007 7.3.1.14: 970 * In an ADDBA Response frame, when the Status Code field 971 * is set to 0, the Buffer Size subfield is set to a value 972 * of at least 1. 973 */ 974 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 975 == WLAN_STATUS_SUCCESS && buf_size) { 976 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 977 &tid_tx->state)) { 978 /* ignore duplicate response */ 979 goto out; 980 } 981 982 tid_tx->buf_size = buf_size; 983 tid_tx->amsdu = amsdu; 984 985 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 986 ieee80211_agg_tx_operational(local, sta, tid); 987 988 sta->ampdu_mlme.addba_req_num[tid] = 0; 989 990 if (tid_tx->timeout) { 991 mod_timer(&tid_tx->session_timer, 992 TU_TO_EXP_TIME(tid_tx->timeout)); 993 tid_tx->last_tx = jiffies; 994 } 995 996 } else { 997 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED); 998 } 999 1000 out: 1001 mutex_unlock(&sta->ampdu_mlme.mtx); 1002 } 1003