/net/mac80211/agg-tx.c
C | 1006 lines | 630 code | 177 blank | 199 comment | 90 complexity | 31f2c59a8cff6902df7616e2650d1db8 MD5 | raw file
1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * HT handling 4 * 5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 6 * Copyright 2002-2005, Instant802 Networks, Inc. 7 * Copyright 2005-2006, Devicescape Software, Inc. 8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 10 * Copyright 2007-2010, Intel Corporation 11 * Copyright(c) 2015-2017 Intel Deutschland GmbH 12 * Copyright (C) 2018 - 2019 Intel Corporation 13 */ 14 15#include <linux/ieee80211.h> 16#include <linux/slab.h> 17#include <linux/export.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 * Note that the sta can get destroyed before the BA tear down is 58 * complete. 59 */ 60 61static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 62 const u8 *da, u16 tid, 63 u8 dialog_token, u16 start_seq_num, 64 u16 agg_size, u16 timeout) 65{ 66 struct ieee80211_local *local = sdata->local; 67 struct sk_buff *skb; 68 struct ieee80211_mgmt *mgmt; 69 u16 capab; 70 71 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 72 73 if (!skb) 74 return; 75 76 skb_reserve(skb, local->hw.extra_tx_headroom); 77 mgmt = skb_put_zero(skb, 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 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 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 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 87 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 88 89 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 90 IEEE80211_STYPE_ACTION); 91 92 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 93 94 mgmt->u.action.category = WLAN_CATEGORY_BACK; 95 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 96 97 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 98 capab = (u16)(1 << 0); /* bit 0 A-MSDU support */ 99 capab |= (u16)(1 << 1); /* bit 1 aggregation policy */ 100 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 101 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 102 103 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 104 105 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 106 mgmt->u.action.u.addba_req.start_seq_num = 107 cpu_to_le16(start_seq_num << 4); 108 109 ieee80211_tx_skb(sdata, skb); 110} 111 112void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) 113{ 114 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 115 struct ieee80211_local *local = sdata->local; 116 struct sk_buff *skb; 117 struct ieee80211_bar *bar; 118 u16 bar_control = 0; 119 120 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); 121 if (!skb) 122 return; 123 124 skb_reserve(skb, local->hw.extra_tx_headroom); 125 bar = skb_put_zero(skb, sizeof(*bar)); 126 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 127 IEEE80211_STYPE_BACK_REQ); 128 memcpy(bar->ra, ra, ETH_ALEN); 129 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 130 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 131 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 132 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 133 bar->control = cpu_to_le16(bar_control); 134 bar->start_seq_num = cpu_to_le16(ssn); 135 136 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | 137 IEEE80211_TX_CTL_REQ_TX_STATUS; 138 ieee80211_tx_skb_tid(sdata, skb, tid); 139} 140EXPORT_SYMBOL(ieee80211_send_bar); 141 142void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 143 struct tid_ampdu_tx *tid_tx) 144{ 145 lockdep_assert_held(&sta->ampdu_mlme.mtx); 146 lockdep_assert_held(&sta->lock); 147 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 148} 149 150/* 151 * When multiple aggregation sessions on multiple stations 152 * are being created/destroyed simultaneously, we need to 153 * refcount the global queue stop caused by that in order 154 * to not get into a situation where one of the aggregation 155 * setup or teardown re-enables queues before the other is 156 * ready to handle that. 157 * 158 * These two functions take care of this issue by keeping 159 * a global "agg_queue_stop" refcount. 160 */ 161static void __acquires(agg_queue) 162ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 163{ 164 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 165 166 /* we do refcounting here, so don't use the queue reason refcounting */ 167 168 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1) 169 ieee80211_stop_queue_by_reason( 170 &sdata->local->hw, queue, 171 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 172 false); 173 __acquire(agg_queue); 174} 175 176static void __releases(agg_queue) 177ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 178{ 179 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 180 181 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0) 182 ieee80211_wake_queue_by_reason( 183 &sdata->local->hw, queue, 184 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 185 false); 186 __release(agg_queue); 187} 188 189static void 190ieee80211_agg_stop_txq(struct sta_info *sta, int tid) 191{ 192 struct ieee80211_txq *txq = sta->sta.txq[tid]; 193 struct ieee80211_sub_if_data *sdata; 194 struct fq *fq; 195 struct txq_info *txqi; 196 197 if (!txq) 198 return; 199 200 txqi = to_txq_info(txq); 201 sdata = vif_to_sdata(txq->vif); 202 fq = &sdata->local->fq; 203 204 /* Lock here to protect against further seqno updates on dequeue */ 205 spin_lock_bh(&fq->lock); 206 set_bit(IEEE80211_TXQ_STOP, &txqi->flags); 207 spin_unlock_bh(&fq->lock); 208} 209 210static void 211ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) 212{ 213 struct ieee80211_txq *txq = sta->sta.txq[tid]; 214 struct txq_info *txqi; 215 216 if (!txq) 217 return; 218 219 txqi = to_txq_info(txq); 220 221 if (enable) 222 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 223 else 224 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 225 226 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); 227 local_bh_disable(); 228 rcu_read_lock(); 229 schedule_and_wake_txq(sta->sdata->local, txqi); 230 rcu_read_unlock(); 231 local_bh_enable(); 232} 233 234/* 235 * splice packets from the STA's pending to the local pending, 236 * requires a call to ieee80211_agg_splice_finish later 237 */ 238static void __acquires(agg_queue) 239ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata, 240 struct tid_ampdu_tx *tid_tx, u16 tid) 241{ 242 struct ieee80211_local *local = sdata->local; 243 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 244 unsigned long flags; 245 246 ieee80211_stop_queue_agg(sdata, tid); 247 248 if (WARN(!tid_tx, 249 "TID %d gone but expected when splicing aggregates from the pending queue\n", 250 tid)) 251 return; 252 253 if (!skb_queue_empty(&tid_tx->pending)) { 254 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 255 /* copy over remaining packets */ 256 skb_queue_splice_tail_init(&tid_tx->pending, 257 &local->pending[queue]); 258 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 259 } 260} 261 262static void __releases(agg_queue) 263ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid) 264{ 265 ieee80211_wake_queue_agg(sdata, tid); 266} 267 268static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid) 269{ 270 struct tid_ampdu_tx *tid_tx; 271 272 lockdep_assert_held(&sta->ampdu_mlme.mtx); 273 lockdep_assert_held(&sta->lock); 274 275 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 276 277 /* 278 * When we get here, the TX path will not be lockless any more wrt. 279 * aggregation, since the OPERATIONAL bit has long been cleared. 280 * Thus it will block on getting the lock, if it occurs. So if we 281 * stop the queue now, we will not get any more packets, and any 282 * that might be being processed will wait for us here, thereby 283 * guaranteeing that no packets go to the tid_tx pending queue any 284 * more. 285 */ 286 287 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 288 289 /* future packets must not find the tid_tx struct any more */ 290 ieee80211_assign_tid_tx(sta, tid, NULL); 291 292 ieee80211_agg_splice_finish(sta->sdata, tid); 293 ieee80211_agg_start_txq(sta, tid, false); 294 295 kfree_rcu(tid_tx, rcu_head); 296} 297 298int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 299 enum ieee80211_agg_stop_reason reason) 300{ 301 struct ieee80211_local *local = sta->local; 302 struct tid_ampdu_tx *tid_tx; 303 struct ieee80211_ampdu_params params = { 304 .sta = &sta->sta, 305 .tid = tid, 306 .buf_size = 0, 307 .amsdu = false, 308 .timeout = 0, 309 .ssn = 0, 310 }; 311 int ret; 312 313 lockdep_assert_held(&sta->ampdu_mlme.mtx); 314 315 switch (reason) { 316 case AGG_STOP_DECLINED: 317 case AGG_STOP_LOCAL_REQUEST: 318 case AGG_STOP_PEER_REQUEST: 319 params.action = IEEE80211_AMPDU_TX_STOP_CONT; 320 break; 321 case AGG_STOP_DESTROY_STA: 322 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH; 323 break; 324 default: 325 WARN_ON_ONCE(1); 326 return -EINVAL; 327 } 328 329 spin_lock_bh(&sta->lock); 330 331 /* free struct pending for start, if present */ 332 tid_tx = sta->ampdu_mlme.tid_start_tx[tid]; 333 kfree(tid_tx); 334 sta->ampdu_mlme.tid_start_tx[tid] = NULL; 335 336 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 337 if (!tid_tx) { 338 spin_unlock_bh(&sta->lock); 339 return -ENOENT; 340 } 341 342 /* 343 * if we're already stopping ignore any new requests to stop 344 * unless we're destroying it in which case notify the driver 345 */ 346 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 347 spin_unlock_bh(&sta->lock); 348 if (reason != AGG_STOP_DESTROY_STA) 349 return -EALREADY; 350 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT; 351 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 352 WARN_ON_ONCE(ret); 353 return 0; 354 } 355 356 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 357 /* not even started yet! */ 358 ieee80211_assign_tid_tx(sta, tid, NULL); 359 spin_unlock_bh(&sta->lock); 360 kfree_rcu(tid_tx, rcu_head); 361 return 0; 362 } 363 364 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 365 366 ieee80211_agg_stop_txq(sta, tid); 367 368 spin_unlock_bh(&sta->lock); 369 370 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n", 371 sta->sta.addr, tid); 372 373 del_timer_sync(&tid_tx->addba_resp_timer); 374 del_timer_sync(&tid_tx->session_timer); 375 376 /* 377 * After this packets are no longer handed right through 378 * to the driver but are put onto tid_tx->pending instead, 379 * with locking to ensure proper access. 380 */ 381 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 382 383 /* 384 * There might be a few packets being processed right now (on 385 * another CPU) that have already gotten past the aggregation 386 * check when it was still OPERATIONAL and consequently have 387 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might 388 * call into the driver at the same time or even before the 389 * TX paths calls into it, which could confuse the driver. 390 * 391 * Wait for all currently running TX paths to finish before 392 * telling the driver. New packets will not go through since 393 * the aggregation session is no longer OPERATIONAL. 394 */ 395 if (!local->in_reconfig) 396 synchronize_net(); 397 398 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ? 399 WLAN_BACK_RECIPIENT : 400 WLAN_BACK_INITIATOR; 401 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; 402 403 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 404 405 /* HW shall not deny going back to legacy */ 406 if (WARN_ON(ret)) { 407 /* 408 * We may have pending packets get stuck in this case... 409 * Not bothering with a workaround for now. 410 */ 411 } 412 413 /* 414 * In the case of AGG_STOP_DESTROY_STA, the driver won't 415 * necessarily call ieee80211_stop_tx_ba_cb(), so this may 416 * seem like we can leave the tid_tx data pending forever. 417 * This is true, in a way, but "forever" is only until the 418 * station struct is actually destroyed. In the meantime, 419 * leaving it around ensures that we don't transmit packets 420 * to the driver on this TID which might confuse it. 421 */ 422 423 return 0; 424} 425 426/* 427 * After sending add Block Ack request we activated a timer until 428 * add Block Ack response will arrive from the recipient. 429 * If this timer expires sta_addba_resp_timer_expired will be executed. 430 */ 431static void sta_addba_resp_timer_expired(struct timer_list *t) 432{ 433 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, addba_resp_timer); 434 struct sta_info *sta = tid_tx->sta; 435 u8 tid = tid_tx->tid; 436 437 /* check if the TID waits for addBA response */ 438 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 439 ht_dbg(sta->sdata, 440 "timer expired on %pM tid %d not expecting addBA response\n", 441 sta->sta.addr, tid); 442 return; 443 } 444 445 ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n", 446 sta->sta.addr, tid); 447 448 ieee80211_stop_tx_ba_session(&sta->sta, tid); 449} 450 451void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 452{ 453 struct tid_ampdu_tx *tid_tx; 454 struct ieee80211_local *local = sta->local; 455 struct ieee80211_sub_if_data *sdata = sta->sdata; 456 struct ieee80211_ampdu_params params = { 457 .sta = &sta->sta, 458 .action = IEEE80211_AMPDU_TX_START, 459 .tid = tid, 460 .buf_size = 0, 461 .amsdu = false, 462 .timeout = 0, 463 }; 464 int ret; 465 u16 buf_size; 466 467 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 468 469 /* 470 * Start queuing up packets for this aggregation session. 471 * We're going to release them once the driver is OK with 472 * that. 473 */ 474 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 475 476 ieee80211_agg_stop_txq(sta, tid); 477 478 /* 479 * Make sure no packets are being processed. This ensures that 480 * we have a valid starting sequence number and that in-flight 481 * packets have been flushed out and no packets for this TID 482 * will go into the driver during the ampdu_action call. 483 */ 484 synchronize_net(); 485 486 params.ssn = sta->tid_seq[tid] >> 4; 487 ret = drv_ampdu_action(local, sdata, ¶ms); 488 if (ret == IEEE80211_AMPDU_TX_START_IMMEDIATE) { 489 /* 490 * We didn't send the request yet, so don't need to check 491 * here if we already got a response, just mark as driver 492 * ready immediately. 493 */ 494 set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state); 495 } else if (ret) { 496 ht_dbg(sdata, 497 "BA request denied - HW unavailable for %pM tid %d\n", 498 sta->sta.addr, tid); 499 spin_lock_bh(&sta->lock); 500 ieee80211_agg_splice_packets(sdata, tid_tx, tid); 501 ieee80211_assign_tid_tx(sta, tid, NULL); 502 ieee80211_agg_splice_finish(sdata, tid); 503 spin_unlock_bh(&sta->lock); 504 505 ieee80211_agg_start_txq(sta, tid, false); 506 507 kfree_rcu(tid_tx, rcu_head); 508 return; 509 } 510 511 /* activate the timer for the recipient's addBA response */ 512 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 513 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n", 514 sta->sta.addr, tid); 515 516 spin_lock_bh(&sta->lock); 517 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies; 518 sta->ampdu_mlme.addba_req_num[tid]++; 519 spin_unlock_bh(&sta->lock); 520 521 if (sta->sta.he_cap.has_he) { 522 buf_size = local->hw.max_tx_aggregation_subframes; 523 } else { 524 /* 525 * We really should use what the driver told us it will 526 * transmit as the maximum, but certain APs (e.g. the 527 * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012) 528 * will crash when we use a lower number. 529 */ 530 buf_size = IEEE80211_MAX_AMPDU_BUF_HT; 531 } 532 533 /* send AddBA request */ 534 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 535 tid_tx->dialog_token, params.ssn, 536 buf_size, tid_tx->timeout); 537} 538 539/* 540 * After accepting the AddBA Response we activated a timer, 541 * resetting it after each frame that we send. 542 */ 543static void sta_tx_agg_session_timer_expired(struct timer_list *t) 544{ 545 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer); 546 struct sta_info *sta = tid_tx->sta; 547 u8 tid = tid_tx->tid; 548 unsigned long timeout; 549 550 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 551 return; 552 } 553 554 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); 555 if (time_is_after_jiffies(timeout)) { 556 mod_timer(&tid_tx->session_timer, timeout); 557 return; 558 } 559 560 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n", 561 sta->sta.addr, tid); 562 563 ieee80211_stop_tx_ba_session(&sta->sta, tid); 564} 565 566int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 567 u16 timeout) 568{ 569 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 570 struct ieee80211_sub_if_data *sdata = sta->sdata; 571 struct ieee80211_local *local = sdata->local; 572 struct tid_ampdu_tx *tid_tx; 573 int ret = 0; 574 575 trace_api_start_tx_ba_session(pubsta, tid); 576 577 if (WARN(sta->reserved_tid == tid, 578 "Requested to start BA session on reserved tid=%d", tid)) 579 return -EINVAL; 580 581 if (!pubsta->ht_cap.ht_supported) 582 return -EINVAL; 583 584 if (WARN_ON_ONCE(!local->ops->ampdu_action)) 585 return -EINVAL; 586 587 if ((tid >= IEEE80211_NUM_TIDS) || 588 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) || 589 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) 590 return -EINVAL; 591 592 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID)) 593 return -EINVAL; 594 595 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n", 596 pubsta->addr, tid); 597 598 if (sdata->vif.type != NL80211_IFTYPE_STATION && 599 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 600 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 601 sdata->vif.type != NL80211_IFTYPE_AP && 602 sdata->vif.type != NL80211_IFTYPE_ADHOC) 603 return -EINVAL; 604 605 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 606 ht_dbg(sdata, 607 "BA sessions blocked - Denying BA session request %pM tid %d\n", 608 sta->sta.addr, tid); 609 return -EINVAL; 610 } 611 612 /* 613 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 614 * member of an IBSS, and has no other existing Block Ack agreement 615 * with the recipient STA, then the initiating STA shall transmit a 616 * Probe Request frame to the recipient STA and shall not transmit an 617 * ADDBA Request frame unless it receives a Probe Response frame 618 * from the recipient within dot11ADDBAFailureTimeout. 619 * 620 * The probe request mechanism for ADDBA is currently not implemented, 621 * but we only build up Block Ack session with HT STAs. This information 622 * is set when we receive a bss info from a probe response or a beacon. 623 */ 624 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 625 !sta->sta.ht_cap.ht_supported) { 626 ht_dbg(sdata, 627 "BA request denied - IBSS STA %pM does not advertise HT support\n", 628 pubsta->addr); 629 return -EINVAL; 630 } 631 632 spin_lock_bh(&sta->lock); 633 634 /* we have tried too many times, receiver does not want A-MPDU */ 635 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 636 ret = -EBUSY; 637 goto err_unlock_sta; 638 } 639 640 /* 641 * if we have tried more than HT_AGG_BURST_RETRIES times we 642 * will spread our requests in time to avoid stalling connection 643 * for too long 644 */ 645 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && 646 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + 647 HT_AGG_RETRIES_PERIOD)) { 648 ht_dbg(sdata, 649 "BA request denied - %d failed requests on %pM tid %u\n", 650 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid); 651 ret = -EBUSY; 652 goto err_unlock_sta; 653 } 654 655 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 656 /* check if the TID is not in aggregation flow already */ 657 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 658 ht_dbg(sdata, 659 "BA request denied - session is not idle on %pM tid %u\n", 660 sta->sta.addr, tid); 661 ret = -EAGAIN; 662 goto err_unlock_sta; 663 } 664 665 /* prepare A-MPDU MLME for Tx aggregation */ 666 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 667 if (!tid_tx) { 668 ret = -ENOMEM; 669 goto err_unlock_sta; 670 } 671 672 skb_queue_head_init(&tid_tx->pending); 673 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 674 675 tid_tx->timeout = timeout; 676 tid_tx->sta = sta; 677 tid_tx->tid = tid; 678 679 /* response timer */ 680 timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0); 681 682 /* tx timer */ 683 timer_setup(&tid_tx->session_timer, 684 sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE); 685 686 /* assign a dialog token */ 687 sta->ampdu_mlme.dialog_token_allocator++; 688 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 689 690 /* 691 * Finally, assign it to the start array; the work item will 692 * collect it and move it to the normal array. 693 */ 694 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 695 696 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 697 698 /* this flow continues off the work */ 699 err_unlock_sta: 700 spin_unlock_bh(&sta->lock); 701 return ret; 702} 703EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 704 705static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 706 struct sta_info *sta, u16 tid) 707{ 708 struct tid_ampdu_tx *tid_tx; 709 struct ieee80211_ampdu_params params = { 710 .sta = &sta->sta, 711 .action = IEEE80211_AMPDU_TX_OPERATIONAL, 712 .tid = tid, 713 .timeout = 0, 714 .ssn = 0, 715 }; 716 717 lockdep_assert_held(&sta->ampdu_mlme.mtx); 718 719 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 720 params.buf_size = tid_tx->buf_size; 721 params.amsdu = tid_tx->amsdu; 722 723 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", 724 sta->sta.addr, tid); 725 726 drv_ampdu_action(local, sta->sdata, ¶ms); 727 728 /* 729 * synchronize with TX path, while splicing the TX path 730 * should block so it won't put more packets onto pending. 731 */ 732 spin_lock_bh(&sta->lock); 733 734 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 735 /* 736 * Now mark as operational. This will be visible 737 * in the TX path, and lets it go lock-free in 738 * the common case. 739 */ 740 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 741 ieee80211_agg_splice_finish(sta->sdata, tid); 742 743 spin_unlock_bh(&sta->lock); 744 745 ieee80211_agg_start_txq(sta, tid, true); 746} 747 748void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, 749 struct tid_ampdu_tx *tid_tx) 750{ 751 struct ieee80211_sub_if_data *sdata = sta->sdata; 752 struct ieee80211_local *local = sdata->local; 753 754 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 755 return; 756 757 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 758 ieee80211_agg_tx_operational(local, sta, tid); 759} 760 761static struct tid_ampdu_tx * 762ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, 763 const u8 *ra, u16 tid, struct sta_info **sta) 764{ 765 struct tid_ampdu_tx *tid_tx; 766 767 if (tid >= IEEE80211_NUM_TIDS) { 768 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", 769 tid, IEEE80211_NUM_TIDS); 770 return NULL; 771 } 772 773 *sta = sta_info_get_bss(sdata, ra); 774 if (!*sta) { 775 ht_dbg(sdata, "Could not find station: %pM\n", ra); 776 return NULL; 777 } 778 779 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); 780 781 if (WARN_ON(!tid_tx)) 782 ht_dbg(sdata, "addBA was not requested!\n"); 783 784 return tid_tx; 785} 786 787void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 788 const u8 *ra, u16 tid) 789{ 790 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 791 struct ieee80211_local *local = sdata->local; 792 struct sta_info *sta; 793 struct tid_ampdu_tx *tid_tx; 794 795 trace_api_start_tx_ba_cb(sdata, ra, tid); 796 797 rcu_read_lock(); 798 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 799 if (!tid_tx) 800 goto out; 801 802 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); 803 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 804 out: 805 rcu_read_unlock(); 806} 807EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 808 809int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 810 enum ieee80211_agg_stop_reason reason) 811{ 812 int ret; 813 814 mutex_lock(&sta->ampdu_mlme.mtx); 815 816 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); 817 818 mutex_unlock(&sta->ampdu_mlme.mtx); 819 820 return ret; 821} 822 823int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 824{ 825 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 826 struct ieee80211_sub_if_data *sdata = sta->sdata; 827 struct ieee80211_local *local = sdata->local; 828 struct tid_ampdu_tx *tid_tx; 829 int ret = 0; 830 831 trace_api_stop_tx_ba_session(pubsta, tid); 832 833 if (!local->ops->ampdu_action) 834 return -EINVAL; 835 836 if (tid >= IEEE80211_NUM_TIDS) 837 return -EINVAL; 838 839 spin_lock_bh(&sta->lock); 840 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 841 842 if (!tid_tx) { 843 ret = -ENOENT; 844 goto unlock; 845 } 846 847 WARN(sta->reserved_tid == tid, 848 "Requested to stop BA session on reserved tid=%d", tid); 849 850 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 851 /* already in progress stopping it */ 852 ret = 0; 853 goto unlock; 854 } 855 856 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 857 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 858 859 unlock: 860 spin_unlock_bh(&sta->lock); 861 return ret; 862} 863EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 864 865void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, 866 struct tid_ampdu_tx *tid_tx) 867{ 868 struct ieee80211_sub_if_data *sdata = sta->sdata; 869 bool send_delba = false; 870 871 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", 872 sta->sta.addr, tid); 873 874 spin_lock_bh(&sta->lock); 875 876 if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 877 ht_dbg(sdata, 878 "unexpected callback to A-MPDU stop for %pM tid %d\n", 879 sta->sta.addr, tid); 880 goto unlock_sta; 881 } 882 883 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 884 send_delba = true; 885 886 ieee80211_remove_tid_tx(sta, tid); 887 888 unlock_sta: 889 spin_unlock_bh(&sta->lock); 890 891 if (send_delba) 892 ieee80211_send_delba(sdata, sta->sta.addr, tid, 893 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 894} 895 896void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 897 const u8 *ra, u16 tid) 898{ 899 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 900 struct ieee80211_local *local = sdata->local; 901 struct sta_info *sta; 902 struct tid_ampdu_tx *tid_tx; 903 904 trace_api_stop_tx_ba_cb(sdata, ra, tid); 905 906 rcu_read_lock(); 907 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 908 if (!tid_tx) 909 goto out; 910 911 set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); 912 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 913 out: 914 rcu_read_unlock(); 915} 916EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 917 918 919void ieee80211_process_addba_resp(struct ieee80211_local *local, 920 struct sta_info *sta, 921 struct ieee80211_mgmt *mgmt, 922 size_t len) 923{ 924 struct tid_ampdu_tx *tid_tx; 925 struct ieee80211_txq *txq; 926 u16 capab, tid, buf_size; 927 bool amsdu; 928 929 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 930 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK; 931 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 932 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 933 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes); 934 935 txq = sta->sta.txq[tid]; 936 if (!amsdu && txq) 937 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags); 938 939 mutex_lock(&sta->ampdu_mlme.mtx); 940 941 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 942 if (!tid_tx) 943 goto out; 944 945 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 946 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n", 947 sta->sta.addr, tid); 948 goto out; 949 } 950 951 del_timer_sync(&tid_tx->addba_resp_timer); 952 953 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", 954 sta->sta.addr, tid); 955 956 /* 957 * addba_resp_timer may have fired before we got here, and 958 * caused WANT_STOP to be set. If the stop then was already 959 * processed further, STOPPING might be set. 960 */ 961 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 962 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 963 ht_dbg(sta->sdata, 964 "got addBA resp for %pM tid %d but we already gave up\n", 965 sta->sta.addr, tid); 966 goto out; 967 } 968 969 /* 970 * IEEE 802.11-2007 7.3.1.14: 971 * In an ADDBA Response frame, when the Status Code field 972 * is set to 0, the Buffer Size subfield is set to a value 973 * of at least 1. 974 */ 975 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 976 == WLAN_STATUS_SUCCESS && buf_size) { 977 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 978 &tid_tx->state)) { 979 /* ignore duplicate response */ 980 goto out; 981 } 982 983 tid_tx->buf_size = buf_size; 984 tid_tx->amsdu = amsdu; 985 986 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 987 ieee80211_agg_tx_operational(local, sta, tid); 988 989 sta->ampdu_mlme.addba_req_num[tid] = 0; 990 991 tid_tx->timeout = 992 le16_to_cpu(mgmt->u.action.u.addba_resp.timeout); 993 994 if (tid_tx->timeout) { 995 mod_timer(&tid_tx->session_timer, 996 TU_TO_EXP_TIME(tid_tx->timeout)); 997 tid_tx->last_tx = jiffies; 998 } 999 1000 } else { 1001 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED); 1002 } 1003 1004 out: 1005 mutex_unlock(&sta->ampdu_mlme.mtx); 1006}