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 del_timer_sync(&tid_rx->reorder_timer); 53 54 for (i = 0; i < tid_rx->buf_size; i++) 55 dev_kfree_skb(tid_rx->reorder_buf[i]); 56 kfree(tid_rx->reorder_buf); 57 kfree(tid_rx->reorder_time); 58 kfree(tid_rx); 59 } 60 61 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 62 u16 initiator, u16 reason, bool tx) 63 { 64 struct ieee80211_local *local = sta->local; 65 struct tid_ampdu_rx *tid_rx; 66 67 lockdep_assert_held(&sta->ampdu_mlme.mtx); 68 69 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid], 70 lockdep_is_held(&sta->ampdu_mlme.mtx)); 71 72 if (!tid_rx) 73 return; 74 75 RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL); 76 77 ht_dbg(sta->sdata, 78 "Rx BA session stop requested for %pM tid %u %s reason: %d\n", 79 sta->sta.addr, tid, 80 initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator", 81 (int)reason); 82 83 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 84 &sta->sta, tid, NULL, 0)) 85 sdata_info(sta->sdata, 86 "HW problem - can not stop rx aggregation for tid %d\n", 87 tid); 88 89 /* check if this is a self generated aggregation halt */ 90 if (initiator == WLAN_BACK_RECIPIENT && tx) 91 ieee80211_send_delba(sta->sdata, sta->sta.addr, 92 tid, WLAN_BACK_RECIPIENT, reason); 93 94 del_timer_sync(&tid_rx->session_timer); 95 96 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 97 } 98 99 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 100 u16 initiator, u16 reason, bool tx) 101 { 102 mutex_lock(&sta->ampdu_mlme.mtx); 103 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 104 mutex_unlock(&sta->ampdu_mlme.mtx); 105 } 106 107 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 108 const u8 *addr) 109 { 110 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 111 struct sta_info *sta; 112 int i; 113 114 rcu_read_lock(); 115 sta = sta_info_get_bss(sdata, addr); 116 if (!sta) { 117 rcu_read_unlock(); 118 return; 119 } 120 121 for (i = 0; i < IEEE80211_NUM_TIDS; i++) 122 if (ba_rx_bitmap & BIT(i)) 123 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 124 125 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 126 rcu_read_unlock(); 127 } 128 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 129 130 /* 131 * After accepting the AddBA Request we activated a timer, 132 * resetting it after each frame that arrives from the originator. 133 */ 134 static void sta_rx_agg_session_timer_expired(unsigned long data) 135 { 136 /* not an elegant detour, but there is no choice as the timer passes 137 * only one argument, and various sta_info are needed here, so init 138 * flow in sta_info_create gives the TID as data, while the timer_to_id 139 * array gives the sta through container_of */ 140 u8 *ptid = (u8 *)data; 141 u8 *timer_to_id = ptid - *ptid; 142 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 143 timer_to_tid[0]); 144 struct tid_ampdu_rx *tid_rx; 145 unsigned long timeout; 146 147 rcu_read_lock(); 148 tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]); 149 if (!tid_rx) { 150 rcu_read_unlock(); 151 return; 152 } 153 154 timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout); 155 if (time_is_after_jiffies(timeout)) { 156 mod_timer(&tid_rx->session_timer, timeout); 157 rcu_read_unlock(); 158 return; 159 } 160 rcu_read_unlock(); 161 162 ht_dbg(sta->sdata, "rx session timer expired on tid %d\n", (u16)*ptid); 163 164 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 165 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 166 } 167 168 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 169 { 170 u8 *ptid = (u8 *)data; 171 u8 *timer_to_id = ptid - *ptid; 172 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 173 timer_to_tid[0]); 174 175 rcu_read_lock(); 176 ieee80211_release_reorder_timeout(sta, *ptid); 177 rcu_read_unlock(); 178 } 179 180 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 181 u8 dialog_token, u16 status, u16 policy, 182 u16 buf_size, u16 timeout) 183 { 184 struct ieee80211_local *local = sdata->local; 185 struct sk_buff *skb; 186 struct ieee80211_mgmt *mgmt; 187 u16 capab; 188 189 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 190 if (!skb) 191 return; 192 193 skb_reserve(skb, local->hw.extra_tx_headroom); 194 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 195 memset(mgmt, 0, 24); 196 memcpy(mgmt->da, da, ETH_ALEN); 197 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 198 if (sdata->vif.type == NL80211_IFTYPE_AP || 199 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 200 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 201 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 202 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 203 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 204 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 205 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 206 207 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 208 IEEE80211_STYPE_ACTION); 209 210 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 211 mgmt->u.action.category = WLAN_CATEGORY_BACK; 212 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 213 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 214 215 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 216 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 217 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 218 219 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 220 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 221 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 222 223 ieee80211_tx_skb(sdata, skb); 224 } 225 226 void ieee80211_process_addba_request(struct ieee80211_local *local, 227 struct sta_info *sta, 228 struct ieee80211_mgmt *mgmt, 229 size_t len) 230 { 231 struct tid_ampdu_rx *tid_agg_rx; 232 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 233 u8 dialog_token; 234 int ret = -EOPNOTSUPP; 235 236 /* extract session parameters from addba request frame */ 237 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 238 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 239 start_seq_num = 240 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 241 242 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 243 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 244 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 245 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 246 247 status = WLAN_STATUS_REQUEST_DECLINED; 248 249 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 250 ht_dbg(sta->sdata, "Suspend in progress - Denying ADDBA request\n"); 251 goto end_no_lock; 252 } 253 254 /* sanity check for incoming parameters: 255 * check if configuration can support the BA policy 256 * and if buffer size does not exceeds max value */ 257 /* XXX: check own ht delayed BA capability?? */ 258 if (((ba_policy != 1) && 259 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 260 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 261 status = WLAN_STATUS_INVALID_QOS_PARAM; 262 ht_dbg_ratelimited(sta->sdata, 263 "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n", 264 mgmt->sa, tid, ba_policy, buf_size); 265 goto end_no_lock; 266 } 267 /* determine default buffer size */ 268 if (buf_size == 0) 269 buf_size = IEEE80211_MAX_AMPDU_BUF; 270 271 /* make sure the size doesn't exceed the maximum supported by the hw */ 272 if (buf_size > local->hw.max_rx_aggregation_subframes) 273 buf_size = local->hw.max_rx_aggregation_subframes; 274 275 /* examine state machine */ 276 mutex_lock(&sta->ampdu_mlme.mtx); 277 278 if (sta->ampdu_mlme.tid_rx[tid]) { 279 ht_dbg_ratelimited(sta->sdata, 280 "unexpected AddBA Req from %pM on tid %u\n", 281 mgmt->sa, tid); 282 283 /* delete existing Rx BA session on the same tid */ 284 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 285 WLAN_STATUS_UNSPECIFIED_QOS, 286 false); 287 } 288 289 /* prepare A-MPDU MLME for Rx aggregation */ 290 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 291 if (!tid_agg_rx) 292 goto end; 293 294 spin_lock_init(&tid_agg_rx->reorder_lock); 295 296 /* rx timer */ 297 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 298 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 299 init_timer_deferrable(&tid_agg_rx->session_timer); 300 301 /* rx reorder timer */ 302 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 303 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 304 init_timer(&tid_agg_rx->reorder_timer); 305 306 /* prepare reordering buffer */ 307 tid_agg_rx->reorder_buf = 308 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL); 309 tid_agg_rx->reorder_time = 310 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 311 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 312 kfree(tid_agg_rx->reorder_buf); 313 kfree(tid_agg_rx->reorder_time); 314 kfree(tid_agg_rx); 315 goto end; 316 } 317 318 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 319 &sta->sta, tid, &start_seq_num, 0); 320 ht_dbg(sta->sdata, "Rx A-MPDU request on tid %d result %d\n", tid, ret); 321 if (ret) { 322 kfree(tid_agg_rx->reorder_buf); 323 kfree(tid_agg_rx->reorder_time); 324 kfree(tid_agg_rx); 325 goto end; 326 } 327 328 /* update data */ 329 tid_agg_rx->dialog_token = dialog_token; 330 tid_agg_rx->ssn = start_seq_num; 331 tid_agg_rx->head_seq_num = start_seq_num; 332 tid_agg_rx->buf_size = buf_size; 333 tid_agg_rx->timeout = timeout; 334 tid_agg_rx->stored_mpdu_num = 0; 335 status = WLAN_STATUS_SUCCESS; 336 337 /* activate it for RX */ 338 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 339 340 if (timeout) { 341 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 342 tid_agg_rx->last_rx = jiffies; 343 } 344 345 end: 346 mutex_unlock(&sta->ampdu_mlme.mtx); 347 348 end_no_lock: 349 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 350 dialog_token, status, 1, buf_size, timeout); 351 } 352