1 /* 2 * HT handling 3 * 4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 5 * Copyright 2002-2005, Instant802 Networks, Inc. 6 * Copyright 2005-2006, Devicescape Software, Inc. 7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 9 * Copyright 2007-2010, Intel Corporation 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #include <linux/ieee80211.h> 17 #include <linux/slab.h> 18 #include <linux/export.h> 19 #include <net/mac80211.h> 20 #include "ieee80211_i.h" 21 #include "driver-ops.h" 22 #include "wme.h" 23 24 /** 25 * DOC: TX A-MPDU aggregation 26 * 27 * Aggregation on the TX side requires setting the hardware flag 28 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed 29 * packets with a flag indicating A-MPDU aggregation. The driver 30 * or device is responsible for actually aggregating the frames, 31 * as well as deciding how many and which to aggregate. 32 * 33 * When TX aggregation is started by some subsystem (usually the rate 34 * control algorithm would be appropriate) by calling the 35 * ieee80211_start_tx_ba_session() function, the driver will be 36 * notified via its @ampdu_action function, with the 37 * %IEEE80211_AMPDU_TX_START action. 38 * 39 * In response to that, the driver is later required to call the 40 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really 41 * start the aggregation session after the peer has also responded. 42 * If the peer responds negatively, the session will be stopped 43 * again right away. Note that it is possible for the aggregation 44 * session to be stopped before the driver has indicated that it 45 * is done setting it up, in which case it must not indicate the 46 * setup completion. 47 * 48 * Also note that, since we also need to wait for a response from 49 * the peer, the driver is notified of the completion of the 50 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the 51 * @ampdu_action callback. 52 * 53 * Similarly, when the aggregation session is stopped by the peer 54 * or something calling ieee80211_stop_tx_ba_session(), the driver's 55 * @ampdu_action function will be called with the action 56 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, 57 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). 58 * Note that the sta can get destroyed before the BA tear down is 59 * complete. 60 */ 61 62 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, 63 const u8 *da, u16 tid, 64 u8 dialog_token, u16 start_seq_num, 65 u16 agg_size, u16 timeout) 66 { 67 struct ieee80211_local *local = sdata->local; 68 struct sk_buff *skb; 69 struct ieee80211_mgmt *mgmt; 70 u16 capab; 71 72 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 73 74 if (!skb) 75 return; 76 77 skb_reserve(skb, local->hw.extra_tx_headroom); 78 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 79 memset(mgmt, 0, 24); 80 memcpy(mgmt->da, da, ETH_ALEN); 81 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 82 if (sdata->vif.type == NL80211_IFTYPE_AP || 83 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 84 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 85 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 86 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 87 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 88 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 89 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 90 91 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 92 IEEE80211_STYPE_ACTION); 93 94 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); 95 96 mgmt->u.action.category = WLAN_CATEGORY_BACK; 97 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; 98 99 mgmt->u.action.u.addba_req.dialog_token = dialog_token; 100 capab = (u16)(1 << 1); /* bit 1 aggregation policy */ 101 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 102 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ 103 104 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); 105 106 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); 107 mgmt->u.action.u.addba_req.start_seq_num = 108 cpu_to_le16(start_seq_num << 4); 109 110 ieee80211_tx_skb_tid(sdata, skb, tid); 111 } 112 113 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) 114 { 115 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 116 struct ieee80211_local *local = sdata->local; 117 struct sk_buff *skb; 118 struct ieee80211_bar *bar; 119 u16 bar_control = 0; 120 121 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); 122 if (!skb) 123 return; 124 125 skb_reserve(skb, local->hw.extra_tx_headroom); 126 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar)); 127 memset(bar, 0, sizeof(*bar)); 128 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | 129 IEEE80211_STYPE_BACK_REQ); 130 memcpy(bar->ra, ra, ETH_ALEN); 131 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); 132 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; 133 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; 134 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); 135 bar->control = cpu_to_le16(bar_control); 136 bar->start_seq_num = cpu_to_le16(ssn); 137 138 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 139 ieee80211_tx_skb_tid(sdata, skb, tid); 140 } 141 EXPORT_SYMBOL(ieee80211_send_bar); 142 143 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, 144 struct tid_ampdu_tx *tid_tx) 145 { 146 lockdep_assert_held(&sta->ampdu_mlme.mtx); 147 lockdep_assert_held(&sta->lock); 148 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); 149 } 150 151 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 152 enum ieee80211_back_parties initiator, 153 bool tx) 154 { 155 struct ieee80211_local *local = sta->local; 156 struct tid_ampdu_tx *tid_tx; 157 int ret; 158 159 lockdep_assert_held(&sta->ampdu_mlme.mtx); 160 161 spin_lock_bh(&sta->lock); 162 163 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 164 if (!tid_tx) { 165 spin_unlock_bh(&sta->lock); 166 return -ENOENT; 167 } 168 169 /* if we're already stopping ignore any new requests to stop */ 170 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 171 spin_unlock_bh(&sta->lock); 172 return -EALREADY; 173 } 174 175 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { 176 /* not even started yet! */ 177 ieee80211_assign_tid_tx(sta, tid, NULL); 178 spin_unlock_bh(&sta->lock); 179 kfree_rcu(tid_tx, rcu_head); 180 return 0; 181 } 182 183 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); 184 185 spin_unlock_bh(&sta->lock); 186 187 #ifdef CONFIG_MAC80211_HT_DEBUG 188 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", 189 sta->sta.addr, tid); 190 #endif /* CONFIG_MAC80211_HT_DEBUG */ 191 192 del_timer_sync(&tid_tx->addba_resp_timer); 193 del_timer_sync(&tid_tx->session_timer); 194 195 /* 196 * After this packets are no longer handed right through 197 * to the driver but are put onto tid_tx->pending instead, 198 * with locking to ensure proper access. 199 */ 200 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 201 202 /* 203 * There might be a few packets being processed right now (on 204 * another CPU) that have already gotten past the aggregation 205 * check when it was still OPERATIONAL and consequently have 206 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might 207 * call into the driver at the same time or even before the 208 * TX paths calls into it, which could confuse the driver. 209 * 210 * Wait for all currently running TX paths to finish before 211 * telling the driver. New packets will not go through since 212 * the aggregation session is no longer OPERATIONAL. 213 */ 214 synchronize_net(); 215 216 tid_tx->stop_initiator = initiator; 217 tid_tx->tx_stop = tx; 218 219 ret = drv_ampdu_action(local, sta->sdata, 220 IEEE80211_AMPDU_TX_STOP, 221 &sta->sta, tid, NULL, 0); 222 223 /* HW shall not deny going back to legacy */ 224 if (WARN_ON(ret)) { 225 /* 226 * We may have pending packets get stuck in this case... 227 * Not bothering with a workaround for now. 228 */ 229 } 230 231 return ret; 232 } 233 234 /* 235 * After sending add Block Ack request we activated a timer until 236 * add Block Ack response will arrive from the recipient. 237 * If this timer expires sta_addba_resp_timer_expired will be executed. 238 */ 239 static void sta_addba_resp_timer_expired(unsigned long data) 240 { 241 /* not an elegant detour, but there is no choice as the timer passes 242 * only one argument, and both sta_info and TID are needed, so init 243 * flow in sta_info_create gives the TID as data, while the timer_to_id 244 * array gives the sta through container_of */ 245 u16 tid = *(u8 *)data; 246 struct sta_info *sta = container_of((void *)data, 247 struct sta_info, timer_to_tid[tid]); 248 struct tid_ampdu_tx *tid_tx; 249 250 /* check if the TID waits for addBA response */ 251 rcu_read_lock(); 252 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); 253 if (!tid_tx || 254 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { 255 rcu_read_unlock(); 256 #ifdef CONFIG_MAC80211_HT_DEBUG 257 printk(KERN_DEBUG "timer expired on tid %d but we are not " 258 "(or no longer) expecting addBA response there\n", 259 tid); 260 #endif 261 return; 262 } 263 264 #ifdef CONFIG_MAC80211_HT_DEBUG 265 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid); 266 #endif 267 268 ieee80211_stop_tx_ba_session(&sta->sta, tid); 269 rcu_read_unlock(); 270 } 271 272 static inline int ieee80211_ac_from_tid(int tid) 273 { 274 return ieee802_1d_to_ac[tid & 7]; 275 } 276 277 /* 278 * When multiple aggregation sessions on multiple stations 279 * are being created/destroyed simultaneously, we need to 280 * refcount the global queue stop caused by that in order 281 * to not get into a situation where one of the aggregation 282 * setup or teardown re-enables queues before the other is 283 * ready to handle that. 284 * 285 * These two functions take care of this issue by keeping 286 * a global "agg_queue_stop" refcount. 287 */ 288 static void __acquires(agg_queue) 289 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid) 290 { 291 int queue = ieee80211_ac_from_tid(tid); 292 293 if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1) 294 ieee80211_stop_queue_by_reason( 295 &local->hw, queue, 296 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 297 __acquire(agg_queue); 298 } 299 300 static void __releases(agg_queue) 301 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid) 302 { 303 int queue = ieee80211_ac_from_tid(tid); 304 305 if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0) 306 ieee80211_wake_queue_by_reason( 307 &local->hw, queue, 308 IEEE80211_QUEUE_STOP_REASON_AGGREGATION); 309 __release(agg_queue); 310 } 311 312 /* 313 * splice packets from the STA's pending to the local pending, 314 * requires a call to ieee80211_agg_splice_finish later 315 */ 316 static void __acquires(agg_queue) 317 ieee80211_agg_splice_packets(struct ieee80211_local *local, 318 struct tid_ampdu_tx *tid_tx, u16 tid) 319 { 320 int queue = ieee80211_ac_from_tid(tid); 321 unsigned long flags; 322 323 ieee80211_stop_queue_agg(local, tid); 324 325 if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates" 326 " from the pending queue\n", tid)) 327 return; 328 329 if (!skb_queue_empty(&tid_tx->pending)) { 330 spin_lock_irqsave(&local->queue_stop_reason_lock, flags); 331 /* copy over remaining packets */ 332 skb_queue_splice_tail_init(&tid_tx->pending, 333 &local->pending[queue]); 334 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); 335 } 336 } 337 338 static void __releases(agg_queue) 339 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid) 340 { 341 ieee80211_wake_queue_agg(local, tid); 342 } 343 344 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) 345 { 346 struct tid_ampdu_tx *tid_tx; 347 struct ieee80211_local *local = sta->local; 348 struct ieee80211_sub_if_data *sdata = sta->sdata; 349 u16 start_seq_num; 350 int ret; 351 352 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 353 354 /* 355 * Start queuing up packets for this aggregation session. 356 * We're going to release them once the driver is OK with 357 * that. 358 */ 359 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 360 361 /* 362 * Make sure no packets are being processed. This ensures that 363 * we have a valid starting sequence number and that in-flight 364 * packets have been flushed out and no packets for this TID 365 * will go into the driver during the ampdu_action call. 366 */ 367 synchronize_net(); 368 369 start_seq_num = sta->tid_seq[tid] >> 4; 370 371 ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, 372 &sta->sta, tid, &start_seq_num, 0); 373 if (ret) { 374 #ifdef CONFIG_MAC80211_HT_DEBUG 375 printk(KERN_DEBUG "BA request denied - HW unavailable for" 376 " tid %d\n", tid); 377 #endif 378 spin_lock_bh(&sta->lock); 379 ieee80211_agg_splice_packets(local, tid_tx, tid); 380 ieee80211_assign_tid_tx(sta, tid, NULL); 381 ieee80211_agg_splice_finish(local, tid); 382 spin_unlock_bh(&sta->lock); 383 384 kfree_rcu(tid_tx, rcu_head); 385 return; 386 } 387 388 /* activate the timer for the recipient's addBA response */ 389 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); 390 #ifdef CONFIG_MAC80211_HT_DEBUG 391 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid); 392 #endif 393 394 spin_lock_bh(&sta->lock); 395 sta->ampdu_mlme.addba_req_num[tid]++; 396 spin_unlock_bh(&sta->lock); 397 398 /* send AddBA request */ 399 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 400 tid_tx->dialog_token, start_seq_num, 401 local->hw.max_tx_aggregation_subframes, 402 tid_tx->timeout); 403 } 404 405 /* 406 * After accepting the AddBA Response we activated a timer, 407 * resetting it after each frame that we send. 408 */ 409 static void sta_tx_agg_session_timer_expired(unsigned long data) 410 { 411 /* not an elegant detour, but there is no choice as the timer passes 412 * only one argument, and various sta_info are needed here, so init 413 * flow in sta_info_create gives the TID as data, while the timer_to_id 414 * array gives the sta through container_of */ 415 u8 *ptid = (u8 *)data; 416 u8 *timer_to_id = ptid - *ptid; 417 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 418 timer_to_tid[0]); 419 420 #ifdef CONFIG_MAC80211_HT_DEBUG 421 printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid); 422 #endif 423 424 ieee80211_stop_tx_ba_session(&sta->sta, *ptid); 425 } 426 427 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 428 u16 timeout) 429 { 430 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 431 struct ieee80211_sub_if_data *sdata = sta->sdata; 432 struct ieee80211_local *local = sdata->local; 433 struct tid_ampdu_tx *tid_tx; 434 int ret = 0; 435 436 trace_api_start_tx_ba_session(pubsta, tid); 437 438 if (WARN_ON(!local->ops->ampdu_action)) 439 return -EINVAL; 440 441 if ((tid >= STA_TID_NUM) || 442 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) || 443 (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) 444 return -EINVAL; 445 446 #ifdef CONFIG_MAC80211_HT_DEBUG 447 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n", 448 pubsta->addr, tid); 449 #endif /* CONFIG_MAC80211_HT_DEBUG */ 450 451 if (sdata->vif.type != NL80211_IFTYPE_STATION && 452 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 453 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 454 sdata->vif.type != NL80211_IFTYPE_AP && 455 sdata->vif.type != NL80211_IFTYPE_ADHOC) 456 return -EINVAL; 457 458 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 459 #ifdef CONFIG_MAC80211_HT_DEBUG 460 printk(KERN_DEBUG "BA sessions blocked. " 461 "Denying BA session request\n"); 462 #endif 463 return -EINVAL; 464 } 465 466 /* 467 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 468 * member of an IBSS, and has no other existing Block Ack agreement 469 * with the recipient STA, then the initiating STA shall transmit a 470 * Probe Request frame to the recipient STA and shall not transmit an 471 * ADDBA Request frame unless it receives a Probe Response frame 472 * from the recipient within dot11ADDBAFailureTimeout. 473 * 474 * The probe request mechanism for ADDBA is currently not implemented, 475 * but we only build up Block Ack session with HT STAs. This information 476 * is set when we receive a bss info from a probe response or a beacon. 477 */ 478 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 479 !sta->sta.ht_cap.ht_supported) { 480 #ifdef CONFIG_MAC80211_HT_DEBUG 481 printk(KERN_DEBUG "BA request denied - IBSS STA %pM" 482 "does not advertise HT support\n", pubsta->addr); 483 #endif /* CONFIG_MAC80211_HT_DEBUG */ 484 return -EINVAL; 485 } 486 487 spin_lock_bh(&sta->lock); 488 489 /* we have tried too many times, receiver does not want A-MPDU */ 490 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 491 ret = -EBUSY; 492 goto err_unlock_sta; 493 } 494 495 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 496 /* check if the TID is not in aggregation flow already */ 497 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 498 #ifdef CONFIG_MAC80211_HT_DEBUG 499 printk(KERN_DEBUG "BA request denied - session is not " 500 "idle on tid %u\n", tid); 501 #endif /* CONFIG_MAC80211_HT_DEBUG */ 502 ret = -EAGAIN; 503 goto err_unlock_sta; 504 } 505 506 /* prepare A-MPDU MLME for Tx aggregation */ 507 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 508 if (!tid_tx) { 509 ret = -ENOMEM; 510 goto err_unlock_sta; 511 } 512 513 skb_queue_head_init(&tid_tx->pending); 514 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 515 516 tid_tx->timeout = timeout; 517 518 /* response timer */ 519 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; 520 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 521 init_timer(&tid_tx->addba_resp_timer); 522 523 /* tx timer */ 524 tid_tx->session_timer.function = sta_tx_agg_session_timer_expired; 525 tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 526 init_timer(&tid_tx->session_timer); 527 528 /* assign a dialog token */ 529 sta->ampdu_mlme.dialog_token_allocator++; 530 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 531 532 /* 533 * Finally, assign it to the start array; the work item will 534 * collect it and move it to the normal array. 535 */ 536 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 537 538 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 539 540 /* this flow continues off the work */ 541 err_unlock_sta: 542 spin_unlock_bh(&sta->lock); 543 return ret; 544 } 545 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 546 547 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 548 struct sta_info *sta, u16 tid) 549 { 550 struct tid_ampdu_tx *tid_tx; 551 552 lockdep_assert_held(&sta->ampdu_mlme.mtx); 553 554 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 555 556 #ifdef CONFIG_MAC80211_HT_DEBUG 557 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); 558 #endif 559 560 drv_ampdu_action(local, sta->sdata, 561 IEEE80211_AMPDU_TX_OPERATIONAL, 562 &sta->sta, tid, NULL, tid_tx->buf_size); 563 564 /* 565 * synchronize with TX path, while splicing the TX path 566 * should block so it won't put more packets onto pending. 567 */ 568 spin_lock_bh(&sta->lock); 569 570 ieee80211_agg_splice_packets(local, tid_tx, tid); 571 /* 572 * Now mark as operational. This will be visible 573 * in the TX path, and lets it go lock-free in 574 * the common case. 575 */ 576 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 577 ieee80211_agg_splice_finish(local, tid); 578 579 spin_unlock_bh(&sta->lock); 580 } 581 582 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) 583 { 584 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 585 struct ieee80211_local *local = sdata->local; 586 struct sta_info *sta; 587 struct tid_ampdu_tx *tid_tx; 588 589 trace_api_start_tx_ba_cb(sdata, ra, tid); 590 591 if (tid >= STA_TID_NUM) { 592 #ifdef CONFIG_MAC80211_HT_DEBUG 593 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 594 tid, STA_TID_NUM); 595 #endif 596 return; 597 } 598 599 mutex_lock(&local->sta_mtx); 600 sta = sta_info_get_bss(sdata, ra); 601 if (!sta) { 602 mutex_unlock(&local->sta_mtx); 603 #ifdef CONFIG_MAC80211_HT_DEBUG 604 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 605 #endif 606 return; 607 } 608 609 mutex_lock(&sta->ampdu_mlme.mtx); 610 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 611 612 if (WARN_ON(!tid_tx)) { 613 #ifdef CONFIG_MAC80211_HT_DEBUG 614 printk(KERN_DEBUG "addBA was not requested!\n"); 615 #endif 616 goto unlock; 617 } 618 619 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 620 goto unlock; 621 622 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 623 ieee80211_agg_tx_operational(local, sta, tid); 624 625 unlock: 626 mutex_unlock(&sta->ampdu_mlme.mtx); 627 mutex_unlock(&local->sta_mtx); 628 } 629 630 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 631 const u8 *ra, u16 tid) 632 { 633 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 634 struct ieee80211_local *local = sdata->local; 635 struct ieee80211_ra_tid *ra_tid; 636 struct sk_buff *skb = dev_alloc_skb(0); 637 638 if (unlikely(!skb)) 639 return; 640 641 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 642 memcpy(&ra_tid->ra, ra, ETH_ALEN); 643 ra_tid->tid = tid; 644 645 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; 646 skb_queue_tail(&sdata->skb_queue, skb); 647 ieee80211_queue_work(&local->hw, &sdata->work); 648 } 649 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 650 651 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 652 enum ieee80211_back_parties initiator, 653 bool tx) 654 { 655 int ret; 656 657 mutex_lock(&sta->ampdu_mlme.mtx); 658 659 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx); 660 661 mutex_unlock(&sta->ampdu_mlme.mtx); 662 663 return ret; 664 } 665 666 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 667 { 668 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 669 struct ieee80211_sub_if_data *sdata = sta->sdata; 670 struct ieee80211_local *local = sdata->local; 671 struct tid_ampdu_tx *tid_tx; 672 int ret = 0; 673 674 trace_api_stop_tx_ba_session(pubsta, tid); 675 676 if (!local->ops->ampdu_action) 677 return -EINVAL; 678 679 if (tid >= STA_TID_NUM) 680 return -EINVAL; 681 682 spin_lock_bh(&sta->lock); 683 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 684 685 if (!tid_tx) { 686 ret = -ENOENT; 687 goto unlock; 688 } 689 690 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 691 /* already in progress stopping it */ 692 ret = 0; 693 goto unlock; 694 } 695 696 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 697 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 698 699 unlock: 700 spin_unlock_bh(&sta->lock); 701 return ret; 702 } 703 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 704 705 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) 706 { 707 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 708 struct ieee80211_local *local = sdata->local; 709 struct sta_info *sta; 710 struct tid_ampdu_tx *tid_tx; 711 712 trace_api_stop_tx_ba_cb(sdata, ra, tid); 713 714 if (tid >= STA_TID_NUM) { 715 #ifdef CONFIG_MAC80211_HT_DEBUG 716 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 717 tid, STA_TID_NUM); 718 #endif 719 return; 720 } 721 722 #ifdef CONFIG_MAC80211_HT_DEBUG 723 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n", 724 ra, tid); 725 #endif /* CONFIG_MAC80211_HT_DEBUG */ 726 727 mutex_lock(&local->sta_mtx); 728 729 sta = sta_info_get_bss(sdata, ra); 730 if (!sta) { 731 #ifdef CONFIG_MAC80211_HT_DEBUG 732 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 733 #endif 734 goto unlock; 735 } 736 737 mutex_lock(&sta->ampdu_mlme.mtx); 738 spin_lock_bh(&sta->lock); 739 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 740 741 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 742 #ifdef CONFIG_MAC80211_HT_DEBUG 743 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); 744 #endif 745 goto unlock_sta; 746 } 747 748 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 749 ieee80211_send_delba(sta->sdata, ra, tid, 750 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 751 752 /* 753 * When we get here, the TX path will not be lockless any more wrt. 754 * aggregation, since the OPERATIONAL bit has long been cleared. 755 * Thus it will block on getting the lock, if it occurs. So if we 756 * stop the queue now, we will not get any more packets, and any 757 * that might be being processed will wait for us here, thereby 758 * guaranteeing that no packets go to the tid_tx pending queue any 759 * more. 760 */ 761 762 ieee80211_agg_splice_packets(local, tid_tx, tid); 763 764 /* future packets must not find the tid_tx struct any more */ 765 ieee80211_assign_tid_tx(sta, tid, NULL); 766 767 ieee80211_agg_splice_finish(local, tid); 768 769 kfree_rcu(tid_tx, rcu_head); 770 771 unlock_sta: 772 spin_unlock_bh(&sta->lock); 773 mutex_unlock(&sta->ampdu_mlme.mtx); 774 unlock: 775 mutex_unlock(&local->sta_mtx); 776 } 777 778 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 779 const u8 *ra, u16 tid) 780 { 781 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 782 struct ieee80211_local *local = sdata->local; 783 struct ieee80211_ra_tid *ra_tid; 784 struct sk_buff *skb = dev_alloc_skb(0); 785 786 if (unlikely(!skb)) 787 return; 788 789 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 790 memcpy(&ra_tid->ra, ra, ETH_ALEN); 791 ra_tid->tid = tid; 792 793 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; 794 skb_queue_tail(&sdata->skb_queue, skb); 795 ieee80211_queue_work(&local->hw, &sdata->work); 796 } 797 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 798 799 800 void ieee80211_process_addba_resp(struct ieee80211_local *local, 801 struct sta_info *sta, 802 struct ieee80211_mgmt *mgmt, 803 size_t len) 804 { 805 struct tid_ampdu_tx *tid_tx; 806 u16 capab, tid; 807 u8 buf_size; 808 809 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 810 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 811 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 812 813 mutex_lock(&sta->ampdu_mlme.mtx); 814 815 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 816 if (!tid_tx) 817 goto out; 818 819 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 820 #ifdef CONFIG_MAC80211_HT_DEBUG 821 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid); 822 #endif 823 goto out; 824 } 825 826 del_timer_sync(&tid_tx->addba_resp_timer); 827 828 #ifdef CONFIG_MAC80211_HT_DEBUG 829 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid); 830 #endif 831 832 /* 833 * addba_resp_timer may have fired before we got here, and 834 * caused WANT_STOP to be set. If the stop then was already 835 * processed further, STOPPING might be set. 836 */ 837 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 838 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 839 #ifdef CONFIG_MAC80211_HT_DEBUG 840 printk(KERN_DEBUG 841 "got addBA resp for tid %d but we already gave up\n", 842 tid); 843 #endif 844 goto out; 845 } 846 847 /* 848 * IEEE 802.11-2007 7.3.1.14: 849 * In an ADDBA Response frame, when the Status Code field 850 * is set to 0, the Buffer Size subfield is set to a value 851 * of at least 1. 852 */ 853 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 854 == WLAN_STATUS_SUCCESS && buf_size) { 855 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 856 &tid_tx->state)) { 857 /* ignore duplicate response */ 858 goto out; 859 } 860 861 tid_tx->buf_size = buf_size; 862 863 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 864 ieee80211_agg_tx_operational(local, sta, tid); 865 866 sta->ampdu_mlme.addba_req_num[tid] = 0; 867 868 if (tid_tx->timeout) 869 mod_timer(&tid_tx->session_timer, 870 TU_TO_EXP_TIME(tid_tx->timeout)); 871 872 } else { 873 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 874 true); 875 } 876 877 out: 878 mutex_unlock(&sta->ampdu_mlme.mtx); 879 } 880