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 * Copyright (C) 2018 Intel Corporation 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License version 2 as 15 * published by the Free Software Foundation. 16 */ 17 18 #include <linux/ieee80211.h> 19 #include <linux/slab.h> 20 #include <linux/export.h> 21 #include <net/mac80211.h> 22 #include "ieee80211_i.h" 23 #include "driver-ops.h" 24 #include "wme.h" 25 26 /** 27 * DOC: TX A-MPDU aggregation 28 * 29 * Aggregation on the TX side requires setting the hardware flag 30 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed 31 * packets with a flag indicating A-MPDU aggregation. The driver 32 * or device is responsible for actually aggregating the frames, 33 * as well as deciding how many and which to aggregate. 34 * 35 * When TX aggregation is started by some subsystem (usually the rate 36 * control algorithm would be appropriate) by calling the 37 * ieee80211_start_tx_ba_session() function, the driver will be 38 * notified via its @ampdu_action function, with the 39 * %IEEE80211_AMPDU_TX_START action. 40 * 41 * In response to that, the driver is later required to call the 42 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really 43 * start the aggregation session after the peer has also responded. 44 * If the peer responds negatively, the session will be stopped 45 * again right away. Note that it is possible for the aggregation 46 * session to be stopped before the driver has indicated that it 47 * is done setting it up, in which case it must not indicate the 48 * setup completion. 49 * 50 * Also note that, since we also need to wait for a response from 51 * the peer, the driver is notified of the completion of the 52 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the 53 * @ampdu_action callback. 54 * 55 * Similarly, when the aggregation session is stopped by the peer 56 * or something calling ieee80211_stop_tx_ba_session(), the driver's 57 * @ampdu_action function will be called with the action 58 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, 59 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). 60 * Note that the sta can get destroyed before the BA tear down is 61 * complete. 62 */ 63 64 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 65 const u8 *da, u16 tid, 66 u8 dialog_token, u16 start_seq_num, 67 u16 agg_size, u16 timeout) 68 { 69 struct ieee80211_local *local = sdata->local; 70 struct sk_buff *skb; 71 struct ieee80211_mgmt *mgmt; 72 u16 capab; 73 74 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 75 76 if (!skb) 77 return; 78 79 skb_reserve(skb, local->hw.extra_tx_headroom); 80 mgmt = skb_put_zero(skb, 24); 81 memcpy(mgmt->da, da, ETH_ALEN); 82 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 83 if (sdata->vif.type == NL80211_IFTYPE_AP || 84 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 85 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 86 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 87 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 88 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 89 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 90 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 91 92 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 93 IEEE80211_STYPE_ACTION); 94 95 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 96 97 mgmt->u.action.category = WLAN_CATEGORY_BACK; 98 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 99 100 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 101 capab = (u16)(1 << 0); /* bit 0 A-MSDU support */ 102 capab |= (u16)(1 << 1); /* bit 1 aggregation policy */ 103 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 104 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 105 106 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 107 108 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 109 mgmt->u.action.u.addba_req.start_seq_num = 110 cpu_to_le16(start_seq_num << 4); 111 112 ieee80211_tx_skb(sdata, skb); 113 } 114 115 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) 116 { 117 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 118 struct ieee80211_local *local = sdata->local; 119 struct sk_buff *skb; 120 struct ieee80211_bar *bar; 121 u16 bar_control = 0; 122 123 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); 124 if (!skb) 125 return; 126 127 skb_reserve(skb, local->hw.extra_tx_headroom); 128 bar = skb_put_zero(skb, sizeof(*bar)); 129 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 130 IEEE80211_STYPE_BACK_REQ); 131 memcpy(bar->ra, ra, ETH_ALEN); 132 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 133 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 134 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 135 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 136 bar->control = cpu_to_le16(bar_control); 137 bar->start_seq_num = cpu_to_le16(ssn); 138 139 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | 140 IEEE80211_TX_CTL_REQ_TX_STATUS; 141 ieee80211_tx_skb_tid(sdata, skb, tid); 142 } 143 EXPORT_SYMBOL(ieee80211_send_bar); 144 145 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 146 struct tid_ampdu_tx *tid_tx) 147 { 148 lockdep_assert_held(&sta->ampdu_mlme.mtx); 149 lockdep_assert_held(&sta->lock); 150 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 151 } 152 153 /* 154 * When multiple aggregation sessions on multiple stations 155 * are being created/destroyed simultaneously, we need to 156 * refcount the global queue stop caused by that in order 157 * to not get into a situation where one of the aggregation 158 * setup or teardown re-enables queues before the other is 159 * ready to handle that. 160 * 161 * These two functions take care of this issue by keeping 162 * a global "agg_queue_stop" refcount. 163 */ 164 static void __acquires(agg_queue) 165 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 166 { 167 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 168 169 /* we do refcounting here, so don't use the queue reason refcounting */ 170 171 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1) 172 ieee80211_stop_queue_by_reason( 173 &sdata->local->hw, queue, 174 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 175 false); 176 __acquire(agg_queue); 177 } 178 179 static void __releases(agg_queue) 180 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 181 { 182 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 183 184 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0) 185 ieee80211_wake_queue_by_reason( 186 &sdata->local->hw, queue, 187 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 188 false); 189 __release(agg_queue); 190 } 191 192 static void 193 ieee80211_agg_stop_txq(struct sta_info *sta, int tid) 194 { 195 struct ieee80211_txq *txq = sta->sta.txq[tid]; 196 struct ieee80211_sub_if_data *sdata; 197 struct fq *fq; 198 struct txq_info *txqi; 199 200 if (!txq) 201 return; 202 203 txqi = to_txq_info(txq); 204 sdata = vif_to_sdata(txq->vif); 205 fq = &sdata->local->fq; 206 207 /* Lock here to protect against further seqno updates on dequeue */ 208 spin_lock_bh(&fq->lock); 209 set_bit(IEEE80211_TXQ_STOP, &txqi->flags); 210 spin_unlock_bh(&fq->lock); 211 } 212 213 static void 214 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) 215 { 216 struct ieee80211_txq *txq = sta->sta.txq[tid]; 217 struct txq_info *txqi; 218 219 if (!txq) 220 return; 221 222 txqi = to_txq_info(txq); 223 224 if (enable) 225 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 226 else 227 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 228 229 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); 230 local_bh_disable(); 231 rcu_read_lock(); 232 drv_wake_tx_queue(sta->sdata->local, txqi); 233 rcu_read_unlock(); 234 local_bh_enable(); 235 } 236 237 /* 238 * splice packets from the STA's pending to the local pending, 239 * requires a call to ieee80211_agg_splice_finish later 240 */ 241 static void __acquires(agg_queue) 242 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata, 243 struct tid_ampdu_tx *tid_tx, u16 tid) 244 { 245 struct ieee80211_local *local = sdata->local; 246 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 247 unsigned long flags; 248 249 ieee80211_stop_queue_agg(sdata, tid); 250 251 if (WARN(!tid_tx, 252 "TID %d gone but expected when splicing aggregates from the pending queue\n", 253 tid)) 254 return; 255 256 if (!skb_queue_empty(&tid_tx->pending)) { 257 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 258 /* copy over remaining packets */ 259 skb_queue_splice_tail_init(&tid_tx->pending, 260 &local->pending[queue]); 261 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 262 } 263 } 264 265 static void __releases(agg_queue) 266 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid) 267 { 268 ieee80211_wake_queue_agg(sdata, tid); 269 } 270 271 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid) 272 { 273 struct tid_ampdu_tx *tid_tx; 274 275 lockdep_assert_held(&sta->ampdu_mlme.mtx); 276 lockdep_assert_held(&sta->lock); 277 278 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 279 280 /* 281 * When we get here, the TX path will not be lockless any more wrt. 282 * aggregation, since the OPERATIONAL bit has long been cleared. 283 * Thus it will block on getting the lock, if it occurs. So if we 284 * stop the queue now, we will not get any more packets, and any 285 * that might be being processed will wait for us here, thereby 286 * guaranteeing that no packets go to the tid_tx pending queue any 287 * more. 288 */ 289 290 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 291 292 /* future packets must not find the tid_tx struct any more */ 293 ieee80211_assign_tid_tx(sta, tid, NULL); 294 295 ieee80211_agg_splice_finish(sta->sdata, tid); 296 ieee80211_agg_start_txq(sta, tid, false); 297 298 kfree_rcu(tid_tx, rcu_head); 299 } 300 301 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 302 enum ieee80211_agg_stop_reason reason) 303 { 304 struct ieee80211_local *local = sta->local; 305 struct tid_ampdu_tx *tid_tx; 306 struct ieee80211_ampdu_params params = { 307 .sta = &sta->sta, 308 .tid = tid, 309 .buf_size = 0, 310 .amsdu = false, 311 .timeout = 0, 312 .ssn = 0, 313 }; 314 int ret; 315 316 lockdep_assert_held(&sta->ampdu_mlme.mtx); 317 318 switch (reason) { 319 case AGG_STOP_DECLINED: 320 case AGG_STOP_LOCAL_REQUEST: 321 case AGG_STOP_PEER_REQUEST: 322 params.action = IEEE80211_AMPDU_TX_STOP_CONT; 323 break; 324 case AGG_STOP_DESTROY_STA: 325 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH; 326 break; 327 default: 328 WARN_ON_ONCE(1); 329 return -EINVAL; 330 } 331 332 spin_lock_bh(&sta->lock); 333 334 /* free struct pending for start, if present */ 335 tid_tx = sta->ampdu_mlme.tid_start_tx[tid]; 336 kfree(tid_tx); 337 sta->ampdu_mlme.tid_start_tx[tid] = NULL; 338 339 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 340 if (!tid_tx) { 341 spin_unlock_bh(&sta->lock); 342 return -ENOENT; 343 } 344 345 /* 346 * if we're already stopping ignore any new requests to stop 347 * unless we're destroying it in which case notify the driver 348 */ 349 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 350 spin_unlock_bh(&sta->lock); 351 if (reason != AGG_STOP_DESTROY_STA) 352 return -EALREADY; 353 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT; 354 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 355 WARN_ON_ONCE(ret); 356 return 0; 357 } 358 359 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 360 /* not even started yet! */ 361 ieee80211_assign_tid_tx(sta, tid, NULL); 362 spin_unlock_bh(&sta->lock); 363 kfree_rcu(tid_tx, rcu_head); 364 return 0; 365 } 366 367 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 368 369 spin_unlock_bh(&sta->lock); 370 371 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n", 372 sta->sta.addr, tid); 373 374 del_timer_sync(&tid_tx->addba_resp_timer); 375 del_timer_sync(&tid_tx->session_timer); 376 377 /* 378 * After this packets are no longer handed right through 379 * to the driver but are put onto tid_tx->pending instead, 380 * with locking to ensure proper access. 381 */ 382 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 383 384 /* 385 * There might be a few packets being processed right now (on 386 * another CPU) that have already gotten past the aggregation 387 * check when it was still OPERATIONAL and consequently have 388 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might 389 * call into the driver at the same time or even before the 390 * TX paths calls into it, which could confuse the driver. 391 * 392 * Wait for all currently running TX paths to finish before 393 * telling the driver. New packets will not go through since 394 * the aggregation session is no longer OPERATIONAL. 395 */ 396 if (!local->in_reconfig) 397 synchronize_net(); 398 399 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ? 400 WLAN_BACK_RECIPIENT : 401 WLAN_BACK_INITIATOR; 402 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; 403 404 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 405 406 /* HW shall not deny going back to legacy */ 407 if (WARN_ON(ret)) { 408 /* 409 * We may have pending packets get stuck in this case... 410 * Not bothering with a workaround for now. 411 */ 412 } 413 414 /* 415 * In the case of AGG_STOP_DESTROY_STA, the driver won't 416 * necessarily call ieee80211_stop_tx_ba_cb(), so this may 417 * seem like we can leave the tid_tx data pending forever. 418 * This is true, in a way, but "forever" is only until the 419 * station struct is actually destroyed. In the meantime, 420 * leaving it around ensures that we don't transmit packets 421 * to the driver on this TID which might confuse it. 422 */ 423 424 return 0; 425 } 426 427 /* 428 * After sending add Block Ack request we activated a timer until 429 * add Block Ack response will arrive from the recipient. 430 * If this timer expires sta_addba_resp_timer_expired will be executed. 431 */ 432 static void sta_addba_resp_timer_expired(struct timer_list *t) 433 { 434 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, addba_resp_timer); 435 struct sta_info *sta = tid_tx->sta; 436 u8 tid = tid_tx->tid; 437 438 /* check if the TID waits for addBA response */ 439 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 440 ht_dbg(sta->sdata, 441 "timer expired on %pM tid %d not expecting addBA response\n", 442 sta->sta.addr, tid); 443 return; 444 } 445 446 ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n", 447 sta->sta.addr, tid); 448 449 ieee80211_stop_tx_ba_session(&sta->sta, tid); 450 } 451 452 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 453 { 454 struct tid_ampdu_tx *tid_tx; 455 struct ieee80211_local *local = sta->local; 456 struct ieee80211_sub_if_data *sdata = sta->sdata; 457 struct ieee80211_ampdu_params params = { 458 .sta = &sta->sta, 459 .action = IEEE80211_AMPDU_TX_START, 460 .tid = tid, 461 .buf_size = 0, 462 .amsdu = false, 463 .timeout = 0, 464 }; 465 int ret; 466 u16 buf_size; 467 468 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 469 470 /* 471 * Start queuing up packets for this aggregation session. 472 * We're going to release them once the driver is OK with 473 * that. 474 */ 475 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 476 477 ieee80211_agg_stop_txq(sta, tid); 478 479 /* 480 * Make sure no packets are being processed. This ensures that 481 * we have a valid starting sequence number and that in-flight 482 * packets have been flushed out and no packets for this TID 483 * will go into the driver during the ampdu_action call. 484 */ 485 synchronize_net(); 486 487 params.ssn = sta->tid_seq[tid] >> 4; 488 ret = drv_ampdu_action(local, sdata, ¶ms); 489 if (ret) { 490 ht_dbg(sdata, 491 "BA request denied - HW unavailable for %pM tid %d\n", 492 sta->sta.addr, tid); 493 spin_lock_bh(&sta->lock); 494 ieee80211_agg_splice_packets(sdata, tid_tx, tid); 495 ieee80211_assign_tid_tx(sta, tid, NULL); 496 ieee80211_agg_splice_finish(sdata, tid); 497 spin_unlock_bh(&sta->lock); 498 499 ieee80211_agg_start_txq(sta, tid, false); 500 501 kfree_rcu(tid_tx, rcu_head); 502 return; 503 } 504 505 /* activate the timer for the recipient's addBA response */ 506 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 507 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n", 508 sta->sta.addr, tid); 509 510 spin_lock_bh(&sta->lock); 511 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies; 512 sta->ampdu_mlme.addba_req_num[tid]++; 513 spin_unlock_bh(&sta->lock); 514 515 if (sta->sta.he_cap.has_he) { 516 buf_size = local->hw.max_tx_aggregation_subframes; 517 } else { 518 /* 519 * We really should use what the driver told us it will 520 * transmit as the maximum, but certain APs (e.g. the 521 * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012) 522 * will crash when we use a lower number. 523 */ 524 buf_size = IEEE80211_MAX_AMPDU_BUF_HT; 525 } 526 527 /* send AddBA request */ 528 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 529 tid_tx->dialog_token, params.ssn, 530 buf_size, tid_tx->timeout); 531 } 532 533 /* 534 * After accepting the AddBA Response we activated a timer, 535 * resetting it after each frame that we send. 536 */ 537 static void sta_tx_agg_session_timer_expired(struct timer_list *t) 538 { 539 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer); 540 struct sta_info *sta = tid_tx->sta; 541 u8 tid = tid_tx->tid; 542 unsigned long timeout; 543 544 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 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 return; 552 } 553 554 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n", 555 sta->sta.addr, tid); 556 557 ieee80211_stop_tx_ba_session(&sta->sta, tid); 558 } 559 560 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 561 u16 timeout) 562 { 563 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 564 struct ieee80211_sub_if_data *sdata = sta->sdata; 565 struct ieee80211_local *local = sdata->local; 566 struct tid_ampdu_tx *tid_tx; 567 int ret = 0; 568 569 trace_api_start_tx_ba_session(pubsta, tid); 570 571 if (WARN(sta->reserved_tid == tid, 572 "Requested to start BA session on reserved tid=%d", tid)) 573 return -EINVAL; 574 575 if (!pubsta->ht_cap.ht_supported) 576 return -EINVAL; 577 578 if (WARN_ON_ONCE(!local->ops->ampdu_action)) 579 return -EINVAL; 580 581 if ((tid >= IEEE80211_NUM_TIDS) || 582 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) || 583 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) 584 return -EINVAL; 585 586 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID)) 587 return -EINVAL; 588 589 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n", 590 pubsta->addr, tid); 591 592 if (sdata->vif.type != NL80211_IFTYPE_STATION && 593 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 594 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 595 sdata->vif.type != NL80211_IFTYPE_AP && 596 sdata->vif.type != NL80211_IFTYPE_ADHOC) 597 return -EINVAL; 598 599 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 600 ht_dbg(sdata, 601 "BA sessions blocked - Denying BA session request %pM tid %d\n", 602 sta->sta.addr, tid); 603 return -EINVAL; 604 } 605 606 /* 607 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 608 * member of an IBSS, and has no other existing Block Ack agreement 609 * with the recipient STA, then the initiating STA shall transmit a 610 * Probe Request frame to the recipient STA and shall not transmit an 611 * ADDBA Request frame unless it receives a Probe Response frame 612 * from the recipient within dot11ADDBAFailureTimeout. 613 * 614 * The probe request mechanism for ADDBA is currently not implemented, 615 * but we only build up Block Ack session with HT STAs. This information 616 * is set when we receive a bss info from a probe response or a beacon. 617 */ 618 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 619 !sta->sta.ht_cap.ht_supported) { 620 ht_dbg(sdata, 621 "BA request denied - IBSS STA %pM does not advertise HT support\n", 622 pubsta->addr); 623 return -EINVAL; 624 } 625 626 spin_lock_bh(&sta->lock); 627 628 /* we have tried too many times, receiver does not want A-MPDU */ 629 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 630 ret = -EBUSY; 631 goto err_unlock_sta; 632 } 633 634 /* 635 * if we have tried more than HT_AGG_BURST_RETRIES times we 636 * will spread our requests in time to avoid stalling connection 637 * for too long 638 */ 639 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && 640 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + 641 HT_AGG_RETRIES_PERIOD)) { 642 ht_dbg(sdata, 643 "BA request denied - %d failed requests on %pM tid %u\n", 644 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid); 645 ret = -EBUSY; 646 goto err_unlock_sta; 647 } 648 649 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 650 /* check if the TID is not in aggregation flow already */ 651 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 652 ht_dbg(sdata, 653 "BA request denied - session is not idle on %pM tid %u\n", 654 sta->sta.addr, tid); 655 ret = -EAGAIN; 656 goto err_unlock_sta; 657 } 658 659 /* prepare A-MPDU MLME for Tx aggregation */ 660 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 661 if (!tid_tx) { 662 ret = -ENOMEM; 663 goto err_unlock_sta; 664 } 665 666 skb_queue_head_init(&tid_tx->pending); 667 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 668 669 tid_tx->timeout = timeout; 670 tid_tx->sta = sta; 671 tid_tx->tid = tid; 672 673 /* response timer */ 674 timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0); 675 676 /* tx timer */ 677 timer_setup(&tid_tx->session_timer, 678 sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE); 679 680 /* assign a dialog token */ 681 sta->ampdu_mlme.dialog_token_allocator++; 682 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 683 684 /* 685 * Finally, assign it to the start array; the work item will 686 * collect it and move it to the normal array. 687 */ 688 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 689 690 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 691 692 /* this flow continues off the work */ 693 err_unlock_sta: 694 spin_unlock_bh(&sta->lock); 695 return ret; 696 } 697 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 698 699 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 700 struct sta_info *sta, u16 tid) 701 { 702 struct tid_ampdu_tx *tid_tx; 703 struct ieee80211_ampdu_params params = { 704 .sta = &sta->sta, 705 .action = IEEE80211_AMPDU_TX_OPERATIONAL, 706 .tid = tid, 707 .timeout = 0, 708 .ssn = 0, 709 }; 710 711 lockdep_assert_held(&sta->ampdu_mlme.mtx); 712 713 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 714 params.buf_size = tid_tx->buf_size; 715 params.amsdu = tid_tx->amsdu; 716 717 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", 718 sta->sta.addr, tid); 719 720 drv_ampdu_action(local, sta->sdata, ¶ms); 721 722 /* 723 * synchronize with TX path, while splicing the TX path 724 * should block so it won't put more packets onto pending. 725 */ 726 spin_lock_bh(&sta->lock); 727 728 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 729 /* 730 * Now mark as operational. This will be visible 731 * in the TX path, and lets it go lock-free in 732 * the common case. 733 */ 734 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 735 ieee80211_agg_splice_finish(sta->sdata, tid); 736 737 spin_unlock_bh(&sta->lock); 738 739 ieee80211_agg_start_txq(sta, tid, true); 740 } 741 742 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, 743 struct tid_ampdu_tx *tid_tx) 744 { 745 struct ieee80211_sub_if_data *sdata = sta->sdata; 746 struct ieee80211_local *local = sdata->local; 747 748 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 749 return; 750 751 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 752 ieee80211_agg_tx_operational(local, sta, tid); 753 } 754 755 static struct tid_ampdu_tx * 756 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, 757 const u8 *ra, u16 tid, struct sta_info **sta) 758 { 759 struct tid_ampdu_tx *tid_tx; 760 761 if (tid >= IEEE80211_NUM_TIDS) { 762 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", 763 tid, IEEE80211_NUM_TIDS); 764 return NULL; 765 } 766 767 *sta = sta_info_get_bss(sdata, ra); 768 if (!*sta) { 769 ht_dbg(sdata, "Could not find station: %pM\n", ra); 770 return NULL; 771 } 772 773 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); 774 775 if (WARN_ON(!tid_tx)) 776 ht_dbg(sdata, "addBA was not requested!\n"); 777 778 return tid_tx; 779 } 780 781 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 782 const u8 *ra, u16 tid) 783 { 784 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 785 struct ieee80211_local *local = sdata->local; 786 struct sta_info *sta; 787 struct tid_ampdu_tx *tid_tx; 788 789 trace_api_start_tx_ba_cb(sdata, ra, tid); 790 791 rcu_read_lock(); 792 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 793 if (!tid_tx) 794 goto out; 795 796 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); 797 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 798 out: 799 rcu_read_unlock(); 800 } 801 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 802 803 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 804 enum ieee80211_agg_stop_reason reason) 805 { 806 int ret; 807 808 mutex_lock(&sta->ampdu_mlme.mtx); 809 810 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); 811 812 mutex_unlock(&sta->ampdu_mlme.mtx); 813 814 return ret; 815 } 816 817 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 818 { 819 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 820 struct ieee80211_sub_if_data *sdata = sta->sdata; 821 struct ieee80211_local *local = sdata->local; 822 struct tid_ampdu_tx *tid_tx; 823 int ret = 0; 824 825 trace_api_stop_tx_ba_session(pubsta, tid); 826 827 if (!local->ops->ampdu_action) 828 return -EINVAL; 829 830 if (tid >= IEEE80211_NUM_TIDS) 831 return -EINVAL; 832 833 spin_lock_bh(&sta->lock); 834 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 835 836 if (!tid_tx) { 837 ret = -ENOENT; 838 goto unlock; 839 } 840 841 WARN(sta->reserved_tid == tid, 842 "Requested to stop BA session on reserved tid=%d", tid); 843 844 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 845 /* already in progress stopping it */ 846 ret = 0; 847 goto unlock; 848 } 849 850 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 851 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 852 853 unlock: 854 spin_unlock_bh(&sta->lock); 855 return ret; 856 } 857 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 858 859 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, 860 struct tid_ampdu_tx *tid_tx) 861 { 862 struct ieee80211_sub_if_data *sdata = sta->sdata; 863 bool send_delba = false; 864 865 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", 866 sta->sta.addr, tid); 867 868 spin_lock_bh(&sta->lock); 869 870 if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 871 ht_dbg(sdata, 872 "unexpected callback to A-MPDU stop for %pM tid %d\n", 873 sta->sta.addr, tid); 874 goto unlock_sta; 875 } 876 877 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 878 send_delba = true; 879 880 ieee80211_remove_tid_tx(sta, tid); 881 882 unlock_sta: 883 spin_unlock_bh(&sta->lock); 884 885 if (send_delba) 886 ieee80211_send_delba(sdata, sta->sta.addr, tid, 887 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 888 } 889 890 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 891 const u8 *ra, u16 tid) 892 { 893 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 894 struct ieee80211_local *local = sdata->local; 895 struct sta_info *sta; 896 struct tid_ampdu_tx *tid_tx; 897 898 trace_api_stop_tx_ba_cb(sdata, ra, tid); 899 900 rcu_read_lock(); 901 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 902 if (!tid_tx) 903 goto out; 904 905 set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); 906 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 907 out: 908 rcu_read_unlock(); 909 } 910 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 911 912 913 void ieee80211_process_addba_resp(struct ieee80211_local *local, 914 struct sta_info *sta, 915 struct ieee80211_mgmt *mgmt, 916 size_t len) 917 { 918 struct tid_ampdu_tx *tid_tx; 919 struct ieee80211_txq *txq; 920 u16 capab, tid, buf_size; 921 bool amsdu; 922 923 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 924 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK; 925 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 926 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 927 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes); 928 929 txq = sta->sta.txq[tid]; 930 if (!amsdu && txq) 931 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags); 932 933 mutex_lock(&sta->ampdu_mlme.mtx); 934 935 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 936 if (!tid_tx) 937 goto out; 938 939 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 940 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n", 941 sta->sta.addr, tid); 942 goto out; 943 } 944 945 del_timer_sync(&tid_tx->addba_resp_timer); 946 947 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", 948 sta->sta.addr, tid); 949 950 /* 951 * addba_resp_timer may have fired before we got here, and 952 * caused WANT_STOP to be set. If the stop then was already 953 * processed further, STOPPING might be set. 954 */ 955 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 956 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 957 ht_dbg(sta->sdata, 958 "got addBA resp for %pM tid %d but we already gave up\n", 959 sta->sta.addr, tid); 960 goto out; 961 } 962 963 /* 964 * IEEE 802.11-2007 7.3.1.14: 965 * In an ADDBA Response frame, when the Status Code field 966 * is set to 0, the Buffer Size subfield is set to a value 967 * of at least 1. 968 */ 969 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 970 == WLAN_STATUS_SUCCESS && buf_size) { 971 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 972 &tid_tx->state)) { 973 /* ignore duplicate response */ 974 goto out; 975 } 976 977 tid_tx->buf_size = buf_size; 978 tid_tx->amsdu = amsdu; 979 980 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 981 ieee80211_agg_tx_operational(local, sta, tid); 982 983 sta->ampdu_mlme.addba_req_num[tid] = 0; 984 985 tid_tx->timeout = 986 le16_to_cpu(mgmt->u.action.u.addba_resp.timeout); 987 988 if (tid_tx->timeout) { 989 mod_timer(&tid_tx->session_timer, 990 TU_TO_EXP_TIME(tid_tx->timeout)); 991 tid_tx->last_tx = jiffies; 992 } 993 994 } else { 995 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED); 996 } 997 998 out: 999 mutex_unlock(&sta->ampdu_mlme.mtx); 1000 } 1001