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.last_addba_req_time[tid] = jiffies; 396 sta->ampdu_mlme.addba_req_num[tid]++; 397 spin_unlock_bh(&sta->lock); 398 399 /* send AddBA request */ 400 ieee80211_send_addba_request(sdata, sta->sta.addr, tid, 401 tid_tx->dialog_token, start_seq_num, 402 local->hw.max_tx_aggregation_subframes, 403 tid_tx->timeout); 404 } 405 406 /* 407 * After accepting the AddBA Response we activated a timer, 408 * resetting it after each frame that we send. 409 */ 410 static void sta_tx_agg_session_timer_expired(unsigned long data) 411 { 412 /* not an elegant detour, but there is no choice as the timer passes 413 * only one argument, and various sta_info are needed here, so init 414 * flow in sta_info_create gives the TID as data, while the timer_to_id 415 * array gives the sta through container_of */ 416 u8 *ptid = (u8 *)data; 417 u8 *timer_to_id = ptid - *ptid; 418 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 419 timer_to_tid[0]); 420 421 #ifdef CONFIG_MAC80211_HT_DEBUG 422 printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid); 423 #endif 424 425 ieee80211_stop_tx_ba_session(&sta->sta, *ptid); 426 } 427 428 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, 429 u16 timeout) 430 { 431 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 432 struct ieee80211_sub_if_data *sdata = sta->sdata; 433 struct ieee80211_local *local = sdata->local; 434 struct tid_ampdu_tx *tid_tx; 435 int ret = 0; 436 437 trace_api_start_tx_ba_session(pubsta, tid); 438 439 if (WARN_ON(!local->ops->ampdu_action)) 440 return -EINVAL; 441 442 if ((tid >= STA_TID_NUM) || 443 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) || 444 (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) 445 return -EINVAL; 446 447 #ifdef CONFIG_MAC80211_HT_DEBUG 448 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n", 449 pubsta->addr, tid); 450 #endif /* CONFIG_MAC80211_HT_DEBUG */ 451 452 if (sdata->vif.type != NL80211_IFTYPE_STATION && 453 sdata->vif.type != NL80211_IFTYPE_MESH_POINT && 454 sdata->vif.type != NL80211_IFTYPE_AP_VLAN && 455 sdata->vif.type != NL80211_IFTYPE_AP && 456 sdata->vif.type != NL80211_IFTYPE_ADHOC) 457 return -EINVAL; 458 459 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 460 #ifdef CONFIG_MAC80211_HT_DEBUG 461 printk(KERN_DEBUG "BA sessions blocked. " 462 "Denying BA session request\n"); 463 #endif 464 return -EINVAL; 465 } 466 467 /* 468 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a 469 * member of an IBSS, and has no other existing Block Ack agreement 470 * with the recipient STA, then the initiating STA shall transmit a 471 * Probe Request frame to the recipient STA and shall not transmit an 472 * ADDBA Request frame unless it receives a Probe Response frame 473 * from the recipient within dot11ADDBAFailureTimeout. 474 * 475 * The probe request mechanism for ADDBA is currently not implemented, 476 * but we only build up Block Ack session with HT STAs. This information 477 * is set when we receive a bss info from a probe response or a beacon. 478 */ 479 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && 480 !sta->sta.ht_cap.ht_supported) { 481 #ifdef CONFIG_MAC80211_HT_DEBUG 482 printk(KERN_DEBUG "BA request denied - IBSS STA %pM" 483 "does not advertise HT support\n", pubsta->addr); 484 #endif /* CONFIG_MAC80211_HT_DEBUG */ 485 return -EINVAL; 486 } 487 488 spin_lock_bh(&sta->lock); 489 490 /* we have tried too many times, receiver does not want A-MPDU */ 491 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { 492 ret = -EBUSY; 493 goto err_unlock_sta; 494 } 495 496 /* 497 * if we have tried more than HT_AGG_BURST_RETRIES times we 498 * will spread our requests in time to avoid stalling connection 499 * for too long 500 */ 501 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && 502 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + 503 HT_AGG_RETRIES_PERIOD)) { 504 #ifdef CONFIG_MAC80211_HT_DEBUG 505 printk(KERN_DEBUG "BA request denied - " 506 "waiting a grace period after %d failed requests " 507 "on tid %u\n", 508 sta->ampdu_mlme.addba_req_num[tid], tid); 509 #endif /* CONFIG_MAC80211_HT_DEBUG */ 510 ret = -EBUSY; 511 goto err_unlock_sta; 512 } 513 514 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 515 /* check if the TID is not in aggregation flow already */ 516 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { 517 #ifdef CONFIG_MAC80211_HT_DEBUG 518 printk(KERN_DEBUG "BA request denied - session is not " 519 "idle on tid %u\n", tid); 520 #endif /* CONFIG_MAC80211_HT_DEBUG */ 521 ret = -EAGAIN; 522 goto err_unlock_sta; 523 } 524 525 /* prepare A-MPDU MLME for Tx aggregation */ 526 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); 527 if (!tid_tx) { 528 ret = -ENOMEM; 529 goto err_unlock_sta; 530 } 531 532 skb_queue_head_init(&tid_tx->pending); 533 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); 534 535 tid_tx->timeout = timeout; 536 537 /* response timer */ 538 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; 539 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 540 init_timer(&tid_tx->addba_resp_timer); 541 542 /* tx timer */ 543 tid_tx->session_timer.function = sta_tx_agg_session_timer_expired; 544 tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 545 init_timer(&tid_tx->session_timer); 546 547 /* assign a dialog token */ 548 sta->ampdu_mlme.dialog_token_allocator++; 549 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; 550 551 /* 552 * Finally, assign it to the start array; the work item will 553 * collect it and move it to the normal array. 554 */ 555 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; 556 557 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 558 559 /* this flow continues off the work */ 560 err_unlock_sta: 561 spin_unlock_bh(&sta->lock); 562 return ret; 563 } 564 EXPORT_SYMBOL(ieee80211_start_tx_ba_session); 565 566 static void ieee80211_agg_tx_operational(struct ieee80211_local *local, 567 struct sta_info *sta, u16 tid) 568 { 569 struct tid_ampdu_tx *tid_tx; 570 571 lockdep_assert_held(&sta->ampdu_mlme.mtx); 572 573 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 574 575 #ifdef CONFIG_MAC80211_HT_DEBUG 576 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid); 577 #endif 578 579 drv_ampdu_action(local, sta->sdata, 580 IEEE80211_AMPDU_TX_OPERATIONAL, 581 &sta->sta, tid, NULL, tid_tx->buf_size); 582 583 /* 584 * synchronize with TX path, while splicing the TX path 585 * should block so it won't put more packets onto pending. 586 */ 587 spin_lock_bh(&sta->lock); 588 589 ieee80211_agg_splice_packets(local, tid_tx, tid); 590 /* 591 * Now mark as operational. This will be visible 592 * in the TX path, and lets it go lock-free in 593 * the common case. 594 */ 595 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); 596 ieee80211_agg_splice_finish(local, tid); 597 598 spin_unlock_bh(&sta->lock); 599 } 600 601 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) 602 { 603 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 604 struct ieee80211_local *local = sdata->local; 605 struct sta_info *sta; 606 struct tid_ampdu_tx *tid_tx; 607 608 trace_api_start_tx_ba_cb(sdata, ra, tid); 609 610 if (tid >= STA_TID_NUM) { 611 #ifdef CONFIG_MAC80211_HT_DEBUG 612 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 613 tid, STA_TID_NUM); 614 #endif 615 return; 616 } 617 618 mutex_lock(&local->sta_mtx); 619 sta = sta_info_get_bss(sdata, ra); 620 if (!sta) { 621 mutex_unlock(&local->sta_mtx); 622 #ifdef CONFIG_MAC80211_HT_DEBUG 623 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 624 #endif 625 return; 626 } 627 628 mutex_lock(&sta->ampdu_mlme.mtx); 629 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 630 631 if (WARN_ON(!tid_tx)) { 632 #ifdef CONFIG_MAC80211_HT_DEBUG 633 printk(KERN_DEBUG "addBA was not requested!\n"); 634 #endif 635 goto unlock; 636 } 637 638 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) 639 goto unlock; 640 641 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) 642 ieee80211_agg_tx_operational(local, sta, tid); 643 644 unlock: 645 mutex_unlock(&sta->ampdu_mlme.mtx); 646 mutex_unlock(&local->sta_mtx); 647 } 648 649 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 650 const u8 *ra, u16 tid) 651 { 652 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 653 struct ieee80211_local *local = sdata->local; 654 struct ieee80211_ra_tid *ra_tid; 655 struct sk_buff *skb = dev_alloc_skb(0); 656 657 if (unlikely(!skb)) 658 return; 659 660 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 661 memcpy(&ra_tid->ra, ra, ETH_ALEN); 662 ra_tid->tid = tid; 663 664 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; 665 skb_queue_tail(&sdata->skb_queue, skb); 666 ieee80211_queue_work(&local->hw, &sdata->work); 667 } 668 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); 669 670 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, 671 enum ieee80211_back_parties initiator, 672 bool tx) 673 { 674 int ret; 675 676 mutex_lock(&sta->ampdu_mlme.mtx); 677 678 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx); 679 680 mutex_unlock(&sta->ampdu_mlme.mtx); 681 682 return ret; 683 } 684 685 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) 686 { 687 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 688 struct ieee80211_sub_if_data *sdata = sta->sdata; 689 struct ieee80211_local *local = sdata->local; 690 struct tid_ampdu_tx *tid_tx; 691 int ret = 0; 692 693 trace_api_stop_tx_ba_session(pubsta, tid); 694 695 if (!local->ops->ampdu_action) 696 return -EINVAL; 697 698 if (tid >= STA_TID_NUM) 699 return -EINVAL; 700 701 spin_lock_bh(&sta->lock); 702 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 703 704 if (!tid_tx) { 705 ret = -ENOENT; 706 goto unlock; 707 } 708 709 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 710 /* already in progress stopping it */ 711 ret = 0; 712 goto unlock; 713 } 714 715 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); 716 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); 717 718 unlock: 719 spin_unlock_bh(&sta->lock); 720 return ret; 721 } 722 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); 723 724 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) 725 { 726 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 727 struct ieee80211_local *local = sdata->local; 728 struct sta_info *sta; 729 struct tid_ampdu_tx *tid_tx; 730 731 trace_api_stop_tx_ba_cb(sdata, ra, tid); 732 733 if (tid >= STA_TID_NUM) { 734 #ifdef CONFIG_MAC80211_HT_DEBUG 735 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n", 736 tid, STA_TID_NUM); 737 #endif 738 return; 739 } 740 741 #ifdef CONFIG_MAC80211_HT_DEBUG 742 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n", 743 ra, tid); 744 #endif /* CONFIG_MAC80211_HT_DEBUG */ 745 746 mutex_lock(&local->sta_mtx); 747 748 sta = sta_info_get_bss(sdata, ra); 749 if (!sta) { 750 #ifdef CONFIG_MAC80211_HT_DEBUG 751 printk(KERN_DEBUG "Could not find station: %pM\n", ra); 752 #endif 753 goto unlock; 754 } 755 756 mutex_lock(&sta->ampdu_mlme.mtx); 757 spin_lock_bh(&sta->lock); 758 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 759 760 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 761 #ifdef CONFIG_MAC80211_HT_DEBUG 762 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n"); 763 #endif 764 goto unlock_sta; 765 } 766 767 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) 768 ieee80211_send_delba(sta->sdata, ra, tid, 769 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); 770 771 /* 772 * When we get here, the TX path will not be lockless any more wrt. 773 * aggregation, since the OPERATIONAL bit has long been cleared. 774 * Thus it will block on getting the lock, if it occurs. So if we 775 * stop the queue now, we will not get any more packets, and any 776 * that might be being processed will wait for us here, thereby 777 * guaranteeing that no packets go to the tid_tx pending queue any 778 * more. 779 */ 780 781 ieee80211_agg_splice_packets(local, tid_tx, tid); 782 783 /* future packets must not find the tid_tx struct any more */ 784 ieee80211_assign_tid_tx(sta, tid, NULL); 785 786 ieee80211_agg_splice_finish(local, tid); 787 788 kfree_rcu(tid_tx, rcu_head); 789 790 unlock_sta: 791 spin_unlock_bh(&sta->lock); 792 mutex_unlock(&sta->ampdu_mlme.mtx); 793 unlock: 794 mutex_unlock(&local->sta_mtx); 795 } 796 797 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, 798 const u8 *ra, u16 tid) 799 { 800 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 801 struct ieee80211_local *local = sdata->local; 802 struct ieee80211_ra_tid *ra_tid; 803 struct sk_buff *skb = dev_alloc_skb(0); 804 805 if (unlikely(!skb)) 806 return; 807 808 ra_tid = (struct ieee80211_ra_tid *) &skb->cb; 809 memcpy(&ra_tid->ra, ra, ETH_ALEN); 810 ra_tid->tid = tid; 811 812 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; 813 skb_queue_tail(&sdata->skb_queue, skb); 814 ieee80211_queue_work(&local->hw, &sdata->work); 815 } 816 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); 817 818 819 void ieee80211_process_addba_resp(struct ieee80211_local *local, 820 struct sta_info *sta, 821 struct ieee80211_mgmt *mgmt, 822 size_t len) 823 { 824 struct tid_ampdu_tx *tid_tx; 825 u16 capab, tid; 826 u8 buf_size; 827 828 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); 829 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 830 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 831 832 mutex_lock(&sta->ampdu_mlme.mtx); 833 834 tid_tx = rcu_dereference_protected_tid_tx(sta, tid); 835 if (!tid_tx) 836 goto out; 837 838 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { 839 #ifdef CONFIG_MAC80211_HT_DEBUG 840 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid); 841 #endif 842 goto out; 843 } 844 845 del_timer_sync(&tid_tx->addba_resp_timer); 846 847 #ifdef CONFIG_MAC80211_HT_DEBUG 848 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid); 849 #endif 850 851 /* 852 * addba_resp_timer may have fired before we got here, and 853 * caused WANT_STOP to be set. If the stop then was already 854 * processed further, STOPPING might be set. 855 */ 856 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || 857 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { 858 #ifdef CONFIG_MAC80211_HT_DEBUG 859 printk(KERN_DEBUG 860 "got addBA resp for tid %d but we already gave up\n", 861 tid); 862 #endif 863 goto out; 864 } 865 866 /* 867 * IEEE 802.11-2007 7.3.1.14: 868 * In an ADDBA Response frame, when the Status Code field 869 * is set to 0, the Buffer Size subfield is set to a value 870 * of at least 1. 871 */ 872 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) 873 == WLAN_STATUS_SUCCESS && buf_size) { 874 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, 875 &tid_tx->state)) { 876 /* ignore duplicate response */ 877 goto out; 878 } 879 880 tid_tx->buf_size = buf_size; 881 882 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) 883 ieee80211_agg_tx_operational(local, sta, tid); 884 885 sta->ampdu_mlme.addba_req_num[tid] = 0; 886 887 if (tid_tx->timeout) 888 mod_timer(&tid_tx->session_timer, 889 TU_TO_EXP_TIME(tid_tx->timeout)); 890 891 } else { 892 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 893 true); 894 } 895 896 out: 897 mutex_unlock(&sta->ampdu_mlme.mtx); 898 } 899