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 = (struct ieee80211_mgmt *) skb_put(skb, 24); 80 memset(mgmt, 0, 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 = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar)); 129 memset(bar, 0, sizeof(*bar)); 130 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 131 IEEE80211_STYPE_BACK_REQ); 132 memcpy(bar->ra, ra, ETH_ALEN); 133 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 134 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 135 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 136 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 137 bar->control = cpu_to_le16(bar_control); 138 bar->start_seq_num = cpu_to_le16(ssn); 139 140 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | 141 IEEE80211_TX_CTL_REQ_TX_STATUS; 142 ieee80211_tx_skb_tid(sdata, skb, tid); 143 } 144 EXPORT_SYMBOL(ieee80211_send_bar); 145 146 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 147 struct tid_ampdu_tx *tid_tx) 148 { 149 lockdep_assert_held(&sta->ampdu_mlme.mtx); 150 lockdep_assert_held(&sta->lock); 151 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 152 } 153 154 /* 155 * When multiple aggregation sessions on multiple stations 156 * are being created/destroyed simultaneously, we need to 157 * refcount the global queue stop caused by that in order 158 * to not get into a situation where one of the aggregation 159 * setup or teardown re-enables queues before the other is 160 * ready to handle that. 161 * 162 * These two functions take care of this issue by keeping 163 * a global "agg_queue_stop" refcount. 164 */ 165 static void __acquires(agg_queue) 166 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 167 { 168 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 169 170 /* we do refcounting here, so don't use the queue reason refcounting */ 171 172 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1) 173 ieee80211_stop_queue_by_reason( 174 &sdata->local->hw, queue, 175 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 176 false); 177 __acquire(agg_queue); 178 } 179 180 static void __releases(agg_queue) 181 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) 182 { 183 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; 184 185 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0) 186 ieee80211_wake_queue_by_reason( 187 &sdata->local->hw, queue, 188 IEEE80211_QUEUE_STOP_REASON_AGGREGATION, 189 false); 190 __release(agg_queue); 191 } 192 193 static void 194 ieee80211_agg_stop_txq(struct sta_info *sta, int tid) 195 { 196 struct ieee80211_txq *txq = sta->sta.txq[tid]; 197 struct ieee80211_sub_if_data *sdata; 198 struct fq *fq; 199 struct txq_info *txqi; 200 201 if (!txq) 202 return; 203 204 txqi = to_txq_info(txq); 205 sdata = vif_to_sdata(txq->vif); 206 fq = &sdata->local->fq; 207 208 /* Lock here to protect against further seqno updates on dequeue */ 209 spin_lock_bh(&fq->lock); 210 set_bit(IEEE80211_TXQ_STOP, &txqi->flags); 211 spin_unlock_bh(&fq->lock); 212 } 213 214 static void 215 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) 216 { 217 struct ieee80211_txq *txq = sta->sta.txq[tid]; 218 struct txq_info *txqi; 219 220 if (!txq) 221 return; 222 223 txqi = to_txq_info(txq); 224 225 if (enable) 226 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 227 else 228 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); 229 230 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); 231 drv_wake_tx_queue(sta->sdata->local, txqi); 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 */ 238 static void __acquires(agg_queue) 239 ieee80211_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 } 261 262 static void __releases(agg_queue) 263 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid) 264 { 265 ieee80211_wake_queue_agg(sdata, tid); 266 } 267 268 static 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 } 297 298 int ___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 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 332 if (!tid_tx) { 333 spin_unlock_bh(&sta->lock); 334 return -ENOENT; 335 } 336 337 /* 338 * if we're already stopping ignore any new requests to stop 339 * unless we're destroying it in which case notify the driver 340 */ 341 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 342 spin_unlock_bh(&sta->lock); 343 if (reason != AGG_STOP_DESTROY_STA) 344 return -EALREADY; 345 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT; 346 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 347 WARN_ON_ONCE(ret); 348 return 0; 349 } 350 351 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 352 /* not even started yet! */ 353 ieee80211_assign_tid_tx(sta, tid, NULL); 354 spin_unlock_bh(&sta->lock); 355 kfree_rcu(tid_tx, rcu_head); 356 return 0; 357 } 358 359 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 360 361 spin_unlock_bh(&sta->lock); 362 363 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n", 364 sta->sta.addr, tid); 365 366 del_timer_sync(&tid_tx->addba_resp_timer); 367 del_timer_sync(&tid_tx->session_timer); 368 369 /* 370 * After this packets are no longer handed right through 371 * to the driver but are put onto tid_tx->pending instead, 372 * with locking to ensure proper access. 373 */ 374 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 375 376 /* 377 * There might be a few packets being processed right now (on 378 * another CPU) that have already gotten past the aggregation 379 * check when it was still OPERATIONAL and consequently have 380 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might 381 * call into the driver at the same time or even before the 382 * TX paths calls into it, which could confuse the driver. 383 * 384 * Wait for all currently running TX paths to finish before 385 * telling the driver. New packets will not go through since 386 * the aggregation session is no longer OPERATIONAL. 387 */ 388 synchronize_net(); 389 390 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ? 391 WLAN_BACK_RECIPIENT : 392 WLAN_BACK_INITIATOR; 393 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; 394 395 ret = drv_ampdu_action(local, sta->sdata, ¶ms); 396 397 /* HW shall not deny going back to legacy */ 398 if (WARN_ON(ret)) { 399 /* 400 * We may have pending packets get stuck in this case... 401 * Not bothering with a workaround for now. 402 */ 403 } 404 405 /* 406 * In the case of AGG_STOP_DESTROY_STA, the driver won't 407 * necessarily call ieee80211_stop_tx_ba_cb(), so this may 408 * seem like we can leave the tid_tx data pending forever. 409 * This is true, in a way, but "forever" is only until the 410 * station struct is actually destroyed. In the meantime, 411 * leaving it around ensures that we don't transmit packets 412 * to the driver on this TID which might confuse it. 413 */ 414 415 return 0; 416 } 417 418 /* 419 * After sending add Block Ack request we activated a timer until 420 * add Block Ack response will arrive from the recipient. 421 * If this timer expires sta_addba_resp_timer_expired will be executed. 422 */ 423 static void sta_addba_resp_timer_expired(unsigned long data) 424 { 425 /* not an elegant detour, but there is no choice as the timer passes 426 * only one argument, and both sta_info and TID are needed, so init 427 * flow in sta_info_create gives the TID as data, while the timer_to_id 428 * array gives the sta through container_of */ 429 u16 tid = *(u8 *)data; 430 struct sta_info *sta = container_of((void *)data, 431 struct sta_info, timer_to_tid[tid]); 432 struct tid_ampdu_tx *tid_tx; 433 434 /* check if the TID waits for addBA response */ 435 rcu_read_lock(); 436 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 437 if (!tid_tx || 438 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 439 rcu_read_unlock(); 440 ht_dbg(sta->sdata, 441 "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\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 rcu_read_unlock(); 451 } 452 453 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 454 { 455 struct tid_ampdu_tx *tid_tx; 456 struct ieee80211_local *local = sta->local; 457 struct ieee80211_sub_if_data *sdata = sta->sdata; 458 struct ieee80211_ampdu_params params = { 459 .sta = &sta->sta, 460 .action = IEEE80211_AMPDU_TX_START, 461 .tid = tid, 462 .buf_size = 0, 463 .amsdu = false, 464 .timeout = 0, 465 }; 466 int ret; 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 /* send AddBA request */ 516 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 517 tid_tx->dialog_token, params.ssn, 518 IEEE80211_MAX_AMPDU_BUF, 519 tid_tx->timeout); 520 } 521 522 /* 523 * After accepting the AddBA Response we activated a timer, 524 * resetting it after each frame that we send. 525 */ 526 static void sta_tx_agg_session_timer_expired(unsigned long data) 527 { 528 /* not an elegant detour, but there is no choice as the timer passes 529 * only one argument, and various sta_info are needed here, so init 530 * flow in sta_info_create gives the TID as data, while the timer_to_id 531 * array gives the sta through container_of */ 532 u8 *ptid = (u8 *)data; 533 u8 *timer_to_id = ptid - *ptid; 534 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 535 timer_to_tid[0]); 536 struct tid_ampdu_tx *tid_tx; 537 unsigned long timeout; 538 539 rcu_read_lock(); 540 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]); 541 if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 542 rcu_read_unlock(); 543 return; 544 } 545 546 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); 547 if (time_is_after_jiffies(timeout)) { 548 mod_timer(&tid_tx->session_timer, timeout); 549 rcu_read_unlock(); 550 return; 551 } 552 553 rcu_read_unlock(); 554 555 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n", 556 sta->sta.addr, (u16)*ptid); 557 558 ieee80211_stop_tx_ba_session(&sta->sta, *ptid); 559 } 560 561 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 562 u16 timeout) 563 { 564 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 565 struct ieee80211_sub_if_data *sdata = sta->sdata; 566 struct ieee80211_local *local = sdata->local; 567 struct tid_ampdu_tx *tid_tx; 568 int ret = 0; 569 570 trace_api_start_tx_ba_session(pubsta, tid); 571 572 if (WARN(sta->reserved_tid == tid, 573 "Requested to start BA session on reserved tid=%d", tid)) 574 return -EINVAL; 575 576 if (!pubsta->ht_cap.ht_supported) 577 return -EINVAL; 578 579 if (WARN_ON_ONCE(!local->ops->ampdu_action)) 580 return -EINVAL; 581 582 if ((tid >= IEEE80211_NUM_TIDS) || 583 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) || 584 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) 585 return -EINVAL; 586 587 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID)) 588 return -EINVAL; 589 590 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n", 591 pubsta->addr, tid); 592 593 if (sdata->vif.type != NL80211_IFTYPE_STATION && 594 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 595 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 596 sdata->vif.type != NL80211_IFTYPE_AP && 597 sdata->vif.type != NL80211_IFTYPE_ADHOC) 598 return -EINVAL; 599 600 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 601 ht_dbg(sdata, 602 "BA sessions blocked - Denying BA session request %pM tid %d\n", 603 sta->sta.addr, tid); 604 return -EINVAL; 605 } 606 607 /* 608 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 609 * member of an IBSS, and has no other existing Block Ack agreement 610 * with the recipient STA, then the initiating STA shall transmit a 611 * Probe Request frame to the recipient STA and shall not transmit an 612 * ADDBA Request frame unless it receives a Probe Response frame 613 * from the recipient within dot11ADDBAFailureTimeout. 614 * 615 * The probe request mechanism for ADDBA is currently not implemented, 616 * but we only build up Block Ack session with HT STAs. This information 617 * is set when we receive a bss info from a probe response or a beacon. 618 */ 619 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 620 !sta->sta.ht_cap.ht_supported) { 621 ht_dbg(sdata, 622 "BA request denied - IBSS STA %pM does not advertise HT support\n", 623 pubsta->addr); 624 return -EINVAL; 625 } 626 627 spin_lock_bh(&sta->lock); 628 629 /* we have tried too many times, receiver does not want A-MPDU */ 630 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 631 ret = -EBUSY; 632 goto err_unlock_sta; 633 } 634 635 /* 636 * if we have tried more than HT_AGG_BURST_RETRIES times we 637 * will spread our requests in time to avoid stalling connection 638 * for too long 639 */ 640 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && 641 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + 642 HT_AGG_RETRIES_PERIOD)) { 643 ht_dbg(sdata, 644 "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n", 645 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid); 646 ret = -EBUSY; 647 goto err_unlock_sta; 648 } 649 650 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 651 /* check if the TID is not in aggregation flow already */ 652 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 653 ht_dbg(sdata, 654 "BA request denied - session is not idle on %pM tid %u\n", 655 sta->sta.addr, tid); 656 ret = -EAGAIN; 657 goto err_unlock_sta; 658 } 659 660 /* prepare A-MPDU MLME for Tx aggregation */ 661 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 662 if (!tid_tx) { 663 ret = -ENOMEM; 664 goto err_unlock_sta; 665 } 666 667 skb_queue_head_init(&tid_tx->pending); 668 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 669 670 tid_tx->timeout = timeout; 671 672 /* response timer */ 673 setup_timer(&tid_tx->addba_resp_timer, 674 sta_addba_resp_timer_expired, 675 (unsigned long)&sta->timer_to_tid[tid]); 676 677 /* tx timer */ 678 setup_deferrable_timer(&tid_tx->session_timer, 679 sta_tx_agg_session_timer_expired, 680 (unsigned long)&sta->timer_to_tid[tid]); 681 682 /* assign a dialog token */ 683 sta->ampdu_mlme.dialog_token_allocator++; 684 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 685 686 /* 687 * Finally, assign it to the start array; the work item will 688 * collect it and move it to the normal array. 689 */ 690 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 691 692 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 693 694 /* this flow continues off the work */ 695 err_unlock_sta: 696 spin_unlock_bh(&sta->lock); 697 return ret; 698 } 699 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 700 701 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 702 struct sta_info *sta, u16 tid) 703 { 704 struct tid_ampdu_tx *tid_tx; 705 struct ieee80211_ampdu_params params = { 706 .sta = &sta->sta, 707 .action = IEEE80211_AMPDU_TX_OPERATIONAL, 708 .tid = tid, 709 .timeout = 0, 710 .ssn = 0, 711 }; 712 713 lockdep_assert_held(&sta->ampdu_mlme.mtx); 714 715 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 716 params.buf_size = tid_tx->buf_size; 717 params.amsdu = tid_tx->amsdu; 718 719 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", 720 sta->sta.addr, tid); 721 722 drv_ampdu_action(local, sta->sdata, ¶ms); 723 724 /* 725 * synchronize with TX path, while splicing the TX path 726 * should block so it won't put more packets onto pending. 727 */ 728 spin_lock_bh(&sta->lock); 729 730 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); 731 /* 732 * Now mark as operational. This will be visible 733 * in the TX path, and lets it go lock-free in 734 * the common case. 735 */ 736 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 737 ieee80211_agg_splice_finish(sta->sdata, tid); 738 739 spin_unlock_bh(&sta->lock); 740 741 ieee80211_agg_start_txq(sta, tid, true); 742 } 743 744 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, 745 struct tid_ampdu_tx *tid_tx) 746 { 747 struct ieee80211_sub_if_data *sdata = sta->sdata; 748 struct ieee80211_local *local = sdata->local; 749 750 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 751 return; 752 753 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 754 ieee80211_agg_tx_operational(local, sta, tid); 755 } 756 757 static struct tid_ampdu_tx * 758 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, 759 const u8 *ra, u16 tid, struct sta_info **sta) 760 { 761 struct tid_ampdu_tx *tid_tx; 762 763 if (tid >= IEEE80211_NUM_TIDS) { 764 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", 765 tid, IEEE80211_NUM_TIDS); 766 return NULL; 767 } 768 769 *sta = sta_info_get_bss(sdata, ra); 770 if (!*sta) { 771 ht_dbg(sdata, "Could not find station: %pM\n", ra); 772 return NULL; 773 } 774 775 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); 776 777 if (WARN_ON(!tid_tx)) 778 ht_dbg(sdata, "addBA was not requested!\n"); 779 780 return tid_tx; 781 } 782 783 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 784 const u8 *ra, u16 tid) 785 { 786 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 787 struct ieee80211_local *local = sdata->local; 788 struct sta_info *sta; 789 struct tid_ampdu_tx *tid_tx; 790 791 trace_api_start_tx_ba_cb(sdata, ra, tid); 792 793 rcu_read_lock(); 794 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 795 if (!tid_tx) 796 goto out; 797 798 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); 799 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 800 out: 801 rcu_read_unlock(); 802 } 803 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 804 805 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 806 enum ieee80211_agg_stop_reason reason) 807 { 808 int ret; 809 810 mutex_lock(&sta->ampdu_mlme.mtx); 811 812 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); 813 814 mutex_unlock(&sta->ampdu_mlme.mtx); 815 816 return ret; 817 } 818 819 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 820 { 821 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 822 struct ieee80211_sub_if_data *sdata = sta->sdata; 823 struct ieee80211_local *local = sdata->local; 824 struct tid_ampdu_tx *tid_tx; 825 int ret = 0; 826 827 trace_api_stop_tx_ba_session(pubsta, tid); 828 829 if (!local->ops->ampdu_action) 830 return -EINVAL; 831 832 if (tid >= IEEE80211_NUM_TIDS) 833 return -EINVAL; 834 835 spin_lock_bh(&sta->lock); 836 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 837 838 if (!tid_tx) { 839 ret = -ENOENT; 840 goto unlock; 841 } 842 843 WARN(sta->reserved_tid == tid, 844 "Requested to stop BA session on reserved tid=%d", tid); 845 846 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 847 /* already in progress stopping it */ 848 ret = 0; 849 goto unlock; 850 } 851 852 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 853 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 854 855 unlock: 856 spin_unlock_bh(&sta->lock); 857 return ret; 858 } 859 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 860 861 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, 862 struct tid_ampdu_tx *tid_tx) 863 { 864 struct ieee80211_sub_if_data *sdata = sta->sdata; 865 bool send_delba = false; 866 867 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", 868 sta->sta.addr, tid); 869 870 spin_lock_bh(&sta->lock); 871 872 if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 873 ht_dbg(sdata, 874 "unexpected callback to A-MPDU stop for %pM tid %d\n", 875 sta->sta.addr, tid); 876 goto unlock_sta; 877 } 878 879 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 880 send_delba = true; 881 882 ieee80211_remove_tid_tx(sta, tid); 883 884 unlock_sta: 885 spin_unlock_bh(&sta->lock); 886 887 if (send_delba) 888 ieee80211_send_delba(sdata, sta->sta.addr, tid, 889 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 890 } 891 892 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 893 const u8 *ra, u16 tid) 894 { 895 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 896 struct ieee80211_local *local = sdata->local; 897 struct sta_info *sta; 898 struct tid_ampdu_tx *tid_tx; 899 900 trace_api_stop_tx_ba_cb(sdata, ra, tid); 901 902 rcu_read_lock(); 903 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); 904 if (!tid_tx) 905 goto out; 906 907 set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); 908 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 909 out: 910 rcu_read_unlock(); 911 } 912 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 913 914 915 void ieee80211_process_addba_resp(struct ieee80211_local *local, 916 struct sta_info *sta, 917 struct ieee80211_mgmt *mgmt, 918 size_t len) 919 { 920 struct tid_ampdu_tx *tid_tx; 921 struct ieee80211_txq *txq; 922 u16 capab, tid; 923 u8 buf_size; 924 bool amsdu; 925 926 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 927 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK; 928 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 929 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 930 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes); 931 932 txq = sta->sta.txq[tid]; 933 if (!amsdu && txq) 934 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags); 935 936 mutex_lock(&sta->ampdu_mlme.mtx); 937 938 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 939 if (!tid_tx) 940 goto out; 941 942 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 943 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n", 944 sta->sta.addr, tid); 945 goto out; 946 } 947 948 del_timer_sync(&tid_tx->addba_resp_timer); 949 950 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", 951 sta->sta.addr, tid); 952 953 /* 954 * addba_resp_timer may have fired before we got here, and 955 * caused WANT_STOP to be set. If the stop then was already 956 * processed further, STOPPING might be set. 957 */ 958 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 959 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 960 ht_dbg(sta->sdata, 961 "got addBA resp for %pM tid %d but we already gave up\n", 962 sta->sta.addr, tid); 963 goto out; 964 } 965 966 /* 967 * IEEE 802.11-2007 7.3.1.14: 968 * In an ADDBA Response frame, when the Status Code field 969 * is set to 0, the Buffer Size subfield is set to a value 970 * of at least 1. 971 */ 972 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 973 == WLAN_STATUS_SUCCESS && buf_size) { 974 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 975 &tid_tx->state)) { 976 /* ignore duplicate response */ 977 goto out; 978 } 979 980 tid_tx->buf_size = buf_size; 981 tid_tx->amsdu = amsdu; 982 983 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 984 ieee80211_agg_tx_operational(local, sta, tid); 985 986 sta->ampdu_mlme.addba_req_num[tid] = 0; 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