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/** 17 * DOC: RX A-MPDU aggregation 18 * 19 * Aggregation on the RX side requires only implementing the 20 * @ampdu_action callback that is invoked to start/stop any 21 * block-ack sessions for RX aggregation. 22 * 23 * When RX aggregation is started by the peer, the driver is 24 * notified via @ampdu_action function, with the 25 * %IEEE80211_AMPDU_RX_START action, and may reject the request 26 * in which case a negative response is sent to the peer, if it 27 * accepts it a positive response is sent. 28 * 29 * While the session is active, the device/driver are required 30 * to de-aggregate frames and pass them up one by one to mac80211, 31 * which will handle the reorder buffer. 32 * 33 * When the aggregation session is stopped again by the peer or 34 * ourselves, the driver's @ampdu_action function will be called 35 * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the 36 * call must not fail. 37 */ 38 39#include <linux/ieee80211.h> 40#include <linux/slab.h> 41#include <linux/export.h> 42#include <net/mac80211.h> 43#include "ieee80211_i.h" 44#include "driver-ops.h" 45 46static void ieee80211_free_tid_rx(struct rcu_head *h) 47{ 48 struct tid_ampdu_rx *tid_rx = 49 container_of(h, struct tid_ampdu_rx, rcu_head); 50 int i; 51 52 for (i = 0; i < tid_rx->buf_size; i++) 53 __skb_queue_purge(&tid_rx->reorder_buf[i]); 54 kfree(tid_rx->reorder_buf); 55 kfree(tid_rx->reorder_time); 56 kfree(tid_rx); 57} 58 59void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 60 u16 initiator, u16 reason, bool tx) 61{ 62 struct ieee80211_local *local = sta->local; 63 struct tid_ampdu_rx *tid_rx; 64 65 lockdep_assert_held(&sta->ampdu_mlme.mtx); 66 67 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid], 68 lockdep_is_held(&sta->ampdu_mlme.mtx)); 69 70 if (!tid_rx) 71 return; 72 73 RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL); 74 75 ht_dbg(sta->sdata, 76 "Rx BA session stop requested for %pM tid %u %s reason: %d\n", 77 sta->sta.addr, tid, 78 initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator", 79 (int)reason); 80 81 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 82 &sta->sta, tid, NULL, 0)) 83 sdata_info(sta->sdata, 84 "HW problem - can not stop rx aggregation for %pM tid %d\n", 85 sta->sta.addr, tid); 86 87 /* check if this is a self generated aggregation halt */ 88 if (initiator == WLAN_BACK_RECIPIENT && tx) 89 ieee80211_send_delba(sta->sdata, sta->sta.addr, 90 tid, WLAN_BACK_RECIPIENT, reason); 91 92 del_timer_sync(&tid_rx->session_timer); 93 94 /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */ 95 spin_lock_bh(&tid_rx->reorder_lock); 96 tid_rx->removed = true; 97 spin_unlock_bh(&tid_rx->reorder_lock); 98 del_timer_sync(&tid_rx->reorder_timer); 99 100 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 101} 102 103void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 104 u16 initiator, u16 reason, bool tx) 105{ 106 mutex_lock(&sta->ampdu_mlme.mtx); 107 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 108 mutex_unlock(&sta->ampdu_mlme.mtx); 109} 110 111void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 112 const u8 *addr) 113{ 114 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 115 struct sta_info *sta; 116 int i; 117 118 rcu_read_lock(); 119 sta = sta_info_get_bss(sdata, addr); 120 if (!sta) { 121 rcu_read_unlock(); 122 return; 123 } 124 125 for (i = 0; i < IEEE80211_NUM_TIDS; i++) 126 if (ba_rx_bitmap & BIT(i)) 127 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 128 129 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 130 rcu_read_unlock(); 131} 132EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 133 134/* 135 * After accepting the AddBA Request we activated a timer, 136 * resetting it after each frame that arrives from the originator. 137 */ 138static void sta_rx_agg_session_timer_expired(unsigned long data) 139{ 140 /* not an elegant detour, but there is no choice as the timer passes 141 * only one argument, and various sta_info are needed here, so init 142 * flow in sta_info_create gives the TID as data, while the timer_to_id 143 * array gives the sta through container_of */ 144 u8 *ptid = (u8 *)data; 145 u8 *timer_to_id = ptid - *ptid; 146 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 147 timer_to_tid[0]); 148 struct tid_ampdu_rx *tid_rx; 149 unsigned long timeout; 150 151 rcu_read_lock(); 152 tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]); 153 if (!tid_rx) { 154 rcu_read_unlock(); 155 return; 156 } 157 158 timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout); 159 if (time_is_after_jiffies(timeout)) { 160 mod_timer(&tid_rx->session_timer, timeout); 161 rcu_read_unlock(); 162 return; 163 } 164 rcu_read_unlock(); 165 166 ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n", 167 sta->sta.addr, (u16)*ptid); 168 169 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 170 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 171} 172 173static void sta_rx_agg_reorder_timer_expired(unsigned long data) 174{ 175 u8 *ptid = (u8 *)data; 176 u8 *timer_to_id = ptid - *ptid; 177 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 178 timer_to_tid[0]); 179 180 rcu_read_lock(); 181 ieee80211_release_reorder_timeout(sta, *ptid); 182 rcu_read_unlock(); 183} 184 185static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 186 u8 dialog_token, u16 status, u16 policy, 187 u16 buf_size, u16 timeout) 188{ 189 struct ieee80211_local *local = sdata->local; 190 struct sk_buff *skb; 191 struct ieee80211_mgmt *mgmt; 192 u16 capab; 193 194 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 195 if (!skb) 196 return; 197 198 skb_reserve(skb, local->hw.extra_tx_headroom); 199 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 200 memset(mgmt, 0, 24); 201 memcpy(mgmt->da, da, ETH_ALEN); 202 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 203 if (sdata->vif.type == NL80211_IFTYPE_AP || 204 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 205 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 206 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 207 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 208 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 209 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 210 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 211 212 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 213 IEEE80211_STYPE_ACTION); 214 215 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 216 mgmt->u.action.category = WLAN_CATEGORY_BACK; 217 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 218 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 219 220 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 221 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 222 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 223 224 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 225 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 226 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 227 228 ieee80211_tx_skb(sdata, skb); 229} 230 231void __ieee80211_start_rx_ba_session(struct sta_info *sta, 232 u8 dialog_token, u16 timeout, 233 u16 start_seq_num, u16 ba_policy, u16 tid, 234 u16 buf_size, bool tx, bool auto_seq) 235{ 236 struct ieee80211_local *local = sta->sdata->local; 237 struct tid_ampdu_rx *tid_agg_rx; 238 int i, ret = -EOPNOTSUPP; 239 u16 status = WLAN_STATUS_REQUEST_DECLINED; 240 241 if (!sta->sta.ht_cap.ht_supported) { 242 ht_dbg(sta->sdata, 243 "STA %pM erroneously requests BA session on tid %d w/o QoS\n", 244 sta->sta.addr, tid); 245 /* send a response anyway, it's an error case if we get here */ 246 goto end_no_lock; 247 } 248 249 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 250 ht_dbg(sta->sdata, 251 "Suspend in progress - Denying ADDBA request (%pM tid %d)\n", 252 sta->sta.addr, tid); 253 goto end_no_lock; 254 } 255 256 /* sanity check for incoming parameters: 257 * check if configuration can support the BA policy 258 * and if buffer size does not exceeds max value */ 259 /* XXX: check own ht delayed BA capability?? */ 260 if (((ba_policy != 1) && 261 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 262 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 263 status = WLAN_STATUS_INVALID_QOS_PARAM; 264 ht_dbg_ratelimited(sta->sdata, 265 "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n", 266 sta->sta.addr, tid, ba_policy, buf_size); 267 goto end_no_lock; 268 } 269 /* determine default buffer size */ 270 if (buf_size == 0) 271 buf_size = IEEE80211_MAX_AMPDU_BUF; 272 273 /* make sure the size doesn't exceed the maximum supported by the hw */ 274 if (buf_size > local->hw.max_rx_aggregation_subframes) 275 buf_size = local->hw.max_rx_aggregation_subframes; 276 277 /* examine state machine */ 278 mutex_lock(&sta->ampdu_mlme.mtx); 279 280 if (sta->ampdu_mlme.tid_rx[tid]) { 281 ht_dbg_ratelimited(sta->sdata, 282 "unexpected AddBA Req from %pM on tid %u\n", 283 sta->sta.addr, tid); 284 285 /* delete existing Rx BA session on the same tid */ 286 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 287 WLAN_STATUS_UNSPECIFIED_QOS, 288 false); 289 } 290 291 /* prepare A-MPDU MLME for Rx aggregation */ 292 tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL); 293 if (!tid_agg_rx) 294 goto end; 295 296 spin_lock_init(&tid_agg_rx->reorder_lock); 297 298 /* rx timer */ 299 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 300 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 301 init_timer_deferrable(&tid_agg_rx->session_timer); 302 303 /* rx reorder timer */ 304 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 305 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 306 init_timer(&tid_agg_rx->reorder_timer); 307 308 /* prepare reordering buffer */ 309 tid_agg_rx->reorder_buf = 310 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL); 311 tid_agg_rx->reorder_time = 312 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 313 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 314 kfree(tid_agg_rx->reorder_buf); 315 kfree(tid_agg_rx->reorder_time); 316 kfree(tid_agg_rx); 317 goto end; 318 } 319 320 for (i = 0; i < buf_size; i++) 321 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]); 322 323 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 324 &sta->sta, tid, &start_seq_num, 0); 325 ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n", 326 sta->sta.addr, tid, ret); 327 if (ret) { 328 kfree(tid_agg_rx->reorder_buf); 329 kfree(tid_agg_rx->reorder_time); 330 kfree(tid_agg_rx); 331 goto end; 332 } 333 334 /* update data */ 335 tid_agg_rx->dialog_token = dialog_token; 336 tid_agg_rx->ssn = start_seq_num; 337 tid_agg_rx->head_seq_num = start_seq_num; 338 tid_agg_rx->buf_size = buf_size; 339 tid_agg_rx->timeout = timeout; 340 tid_agg_rx->stored_mpdu_num = 0; 341 tid_agg_rx->auto_seq = auto_seq; 342 status = WLAN_STATUS_SUCCESS; 343 344 /* activate it for RX */ 345 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 346 347 if (timeout) { 348 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 349 tid_agg_rx->last_rx = jiffies; 350 } 351 352end: 353 mutex_unlock(&sta->ampdu_mlme.mtx); 354 355end_no_lock: 356 if (tx) 357 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 358 dialog_token, status, 1, buf_size, 359 timeout); 360} 361 362void ieee80211_process_addba_request(struct ieee80211_local *local, 363 struct sta_info *sta, 364 struct ieee80211_mgmt *mgmt, 365 size_t len) 366{ 367 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num; 368 u8 dialog_token; 369 370 /* extract session parameters from addba request frame */ 371 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 372 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 373 start_seq_num = 374 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 375 376 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 377 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 378 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 379 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 380 381 __ieee80211_start_rx_ba_session(sta, dialog_token, timeout, 382 start_seq_num, ba_policy, tid, 383 buf_size, true, false); 384} 385 386void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif, 387 const u8 *addr, u16 tid) 388{ 389 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 390 struct ieee80211_local *local = sdata->local; 391 struct ieee80211_rx_agg *rx_agg; 392 struct sk_buff *skb = dev_alloc_skb(0); 393 394 if (unlikely(!skb)) 395 return; 396 397 rx_agg = (struct ieee80211_rx_agg *) &skb->cb; 398 memcpy(&rx_agg->addr, addr, ETH_ALEN); 399 rx_agg->tid = tid; 400 401 skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START; 402 skb_queue_tail(&sdata->skb_queue, skb); 403 ieee80211_queue_work(&local->hw, &sdata->work); 404} 405EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl); 406 407void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif, 408 const u8 *addr, u16 tid) 409{ 410 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 411 struct ieee80211_local *local = sdata->local; 412 struct ieee80211_rx_agg *rx_agg; 413 struct sk_buff *skb = dev_alloc_skb(0); 414 415 if (unlikely(!skb)) 416 return; 417 418 rx_agg = (struct ieee80211_rx_agg *) &skb->cb; 419 memcpy(&rx_agg->addr, addr, ETH_ALEN); 420 rx_agg->tid = tid; 421 422 skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP; 423 skb_queue_tail(&sdata->skb_queue, skb); 424 ieee80211_queue_work(&local->hw, &sdata->work); 425} 426EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl); 427