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 46 static 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 59 void ___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, false)) 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 } 102 103 void __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 } 110 111 void 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 } 132 EXPORT_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 */ 138 static 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 } 172 173 static 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 } 184 185 static 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 bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU); 193 u16 capab; 194 195 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 196 if (!skb) 197 return; 198 199 skb_reserve(skb, local->hw.extra_tx_headroom); 200 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 201 memset(mgmt, 0, 24); 202 memcpy(mgmt->da, da, ETH_ALEN); 203 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 204 if (sdata->vif.type == NL80211_IFTYPE_AP || 205 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 206 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 207 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 208 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 209 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 210 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 211 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 212 213 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 214 IEEE80211_STYPE_ACTION); 215 216 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 217 mgmt->u.action.category = WLAN_CATEGORY_BACK; 218 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 219 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 220 221 capab = (u16)(amsdu << 0); /* bit 0 A-MSDU support */ 222 capab |= (u16)(policy << 1); /* bit 1 aggregation policy */ 223 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 224 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 225 226 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 227 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 228 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 229 230 ieee80211_tx_skb(sdata, skb); 231 } 232 233 void __ieee80211_start_rx_ba_session(struct sta_info *sta, 234 u8 dialog_token, u16 timeout, 235 u16 start_seq_num, u16 ba_policy, u16 tid, 236 u16 buf_size, bool tx, bool auto_seq) 237 { 238 struct ieee80211_local *local = sta->sdata->local; 239 struct tid_ampdu_rx *tid_agg_rx; 240 int i, ret = -EOPNOTSUPP; 241 u16 status = WLAN_STATUS_REQUEST_DECLINED; 242 243 if (!sta->sta.ht_cap.ht_supported) { 244 ht_dbg(sta->sdata, 245 "STA %pM erroneously requests BA session on tid %d w/o QoS\n", 246 sta->sta.addr, tid); 247 /* send a response anyway, it's an error case if we get here */ 248 goto end_no_lock; 249 } 250 251 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 252 ht_dbg(sta->sdata, 253 "Suspend in progress - Denying ADDBA request (%pM tid %d)\n", 254 sta->sta.addr, tid); 255 goto end_no_lock; 256 } 257 258 /* sanity check for incoming parameters: 259 * check if configuration can support the BA policy 260 * and if buffer size does not exceeds max value */ 261 /* XXX: check own ht delayed BA capability?? */ 262 if (((ba_policy != 1) && 263 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 264 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 265 status = WLAN_STATUS_INVALID_QOS_PARAM; 266 ht_dbg_ratelimited(sta->sdata, 267 "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n", 268 sta->sta.addr, tid, ba_policy, buf_size); 269 goto end_no_lock; 270 } 271 /* determine default buffer size */ 272 if (buf_size == 0) 273 buf_size = IEEE80211_MAX_AMPDU_BUF; 274 275 /* make sure the size doesn't exceed the maximum supported by the hw */ 276 if (buf_size > local->hw.max_rx_aggregation_subframes) 277 buf_size = local->hw.max_rx_aggregation_subframes; 278 279 /* examine state machine */ 280 mutex_lock(&sta->ampdu_mlme.mtx); 281 282 if (sta->ampdu_mlme.tid_rx[tid]) { 283 ht_dbg_ratelimited(sta->sdata, 284 "unexpected AddBA Req from %pM on tid %u\n", 285 sta->sta.addr, tid); 286 287 /* delete existing Rx BA session on the same tid */ 288 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 289 WLAN_STATUS_UNSPECIFIED_QOS, 290 false); 291 } 292 293 /* prepare A-MPDU MLME for Rx aggregation */ 294 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 295 if (!tid_agg_rx) 296 goto end; 297 298 spin_lock_init(&tid_agg_rx->reorder_lock); 299 300 /* rx timer */ 301 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 302 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 303 init_timer_deferrable(&tid_agg_rx->session_timer); 304 305 /* rx reorder timer */ 306 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 307 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 308 init_timer(&tid_agg_rx->reorder_timer); 309 310 /* prepare reordering buffer */ 311 tid_agg_rx->reorder_buf = 312 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL); 313 tid_agg_rx->reorder_time = 314 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 315 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 316 kfree(tid_agg_rx->reorder_buf); 317 kfree(tid_agg_rx->reorder_time); 318 kfree(tid_agg_rx); 319 goto end; 320 } 321 322 for (i = 0; i < buf_size; i++) 323 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]); 324 325 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 326 &sta->sta, tid, &start_seq_num, 0, false); 327 ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n", 328 sta->sta.addr, tid, ret); 329 if (ret) { 330 kfree(tid_agg_rx->reorder_buf); 331 kfree(tid_agg_rx->reorder_time); 332 kfree(tid_agg_rx); 333 goto end; 334 } 335 336 /* update data */ 337 tid_agg_rx->dialog_token = dialog_token; 338 tid_agg_rx->ssn = start_seq_num; 339 tid_agg_rx->head_seq_num = start_seq_num; 340 tid_agg_rx->buf_size = buf_size; 341 tid_agg_rx->timeout = timeout; 342 tid_agg_rx->stored_mpdu_num = 0; 343 tid_agg_rx->auto_seq = auto_seq; 344 status = WLAN_STATUS_SUCCESS; 345 346 /* activate it for RX */ 347 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 348 349 if (timeout) { 350 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 351 tid_agg_rx->last_rx = jiffies; 352 } 353 354 end: 355 mutex_unlock(&sta->ampdu_mlme.mtx); 356 357 end_no_lock: 358 if (tx) 359 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 360 dialog_token, status, 1, buf_size, 361 timeout); 362 } 363 364 void ieee80211_process_addba_request(struct ieee80211_local *local, 365 struct sta_info *sta, 366 struct ieee80211_mgmt *mgmt, 367 size_t len) 368 { 369 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num; 370 u8 dialog_token; 371 372 /* extract session parameters from addba request frame */ 373 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 374 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 375 start_seq_num = 376 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 377 378 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 379 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 380 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 381 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 382 383 __ieee80211_start_rx_ba_session(sta, dialog_token, timeout, 384 start_seq_num, ba_policy, tid, 385 buf_size, true, false); 386 } 387 388 void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif, 389 const u8 *addr, u16 tid) 390 { 391 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 392 struct ieee80211_local *local = sdata->local; 393 struct ieee80211_rx_agg *rx_agg; 394 struct sk_buff *skb = dev_alloc_skb(0); 395 396 if (unlikely(!skb)) 397 return; 398 399 rx_agg = (struct ieee80211_rx_agg *) &skb->cb; 400 memcpy(&rx_agg->addr, addr, ETH_ALEN); 401 rx_agg->tid = tid; 402 403 skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START; 404 skb_queue_tail(&sdata->skb_queue, skb); 405 ieee80211_queue_work(&local->hw, &sdata->work); 406 } 407 EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl); 408 409 void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif, 410 const u8 *addr, u16 tid) 411 { 412 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 413 struct ieee80211_local *local = sdata->local; 414 struct ieee80211_rx_agg *rx_agg; 415 struct sk_buff *skb = dev_alloc_skb(0); 416 417 if (unlikely(!skb)) 418 return; 419 420 rx_agg = (struct ieee80211_rx_agg *) &skb->cb; 421 memcpy(&rx_agg->addr, addr, ETH_ALEN); 422 rx_agg->tid = tid; 423 424 skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP; 425 skb_queue_tail(&sdata->skb_queue, skb); 426 ieee80211_queue_work(&local->hw, &sdata->work); 427 } 428 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl); 429