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 #ifdef CONFIG_MAC80211_HT_DEBUG 78 printk(KERN_DEBUG 79 "Rx BA session stop requested for %pM tid %u %s reason: %d\n", 80 sta->sta.addr, tid, 81 initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator", 82 (int)reason); 83 #endif /* CONFIG_MAC80211_HT_DEBUG */ 84 85 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 86 &sta->sta, tid, NULL, 0)) 87 printk(KERN_DEBUG "HW problem - can not stop rx " 88 "aggregation for tid %d\n", tid); 89 90 /* check if this is a self generated aggregation halt */ 91 if (initiator == WLAN_BACK_RECIPIENT && tx) 92 ieee80211_send_delba(sta->sdata, sta->sta.addr, 93 tid, WLAN_BACK_RECIPIENT, reason); 94 95 del_timer_sync(&tid_rx->session_timer); 96 97 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 98 } 99 100 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 101 u16 initiator, u16 reason, bool tx) 102 { 103 mutex_lock(&sta->ampdu_mlme.mtx); 104 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 105 mutex_unlock(&sta->ampdu_mlme.mtx); 106 } 107 108 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 109 const u8 *addr) 110 { 111 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 112 struct sta_info *sta; 113 int i; 114 115 rcu_read_lock(); 116 sta = sta_info_get_bss(sdata, addr); 117 if (!sta) { 118 rcu_read_unlock(); 119 return; 120 } 121 122 for (i = 0; i < STA_TID_NUM; i++) 123 if (ba_rx_bitmap & BIT(i)) 124 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 125 126 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 127 rcu_read_unlock(); 128 } 129 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 130 131 /* 132 * After accepting the AddBA Request we activated a timer, 133 * resetting it after each frame that arrives from the originator. 134 */ 135 static void sta_rx_agg_session_timer_expired(unsigned long data) 136 { 137 /* not an elegant detour, but there is no choice as the timer passes 138 * only one argument, and various sta_info are needed here, so init 139 * flow in sta_info_create gives the TID as data, while the timer_to_id 140 * array gives the sta through container_of */ 141 u8 *ptid = (u8 *)data; 142 u8 *timer_to_id = ptid - *ptid; 143 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 144 timer_to_tid[0]); 145 struct tid_ampdu_rx *tid_rx; 146 unsigned long timeout; 147 148 tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]); 149 if (!tid_rx) 150 return; 151 152 timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout); 153 if (time_is_after_jiffies(timeout)) { 154 mod_timer(&tid_rx->session_timer, timeout); 155 return; 156 } 157 158 #ifdef CONFIG_MAC80211_HT_DEBUG 159 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid); 160 #endif 161 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 162 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 163 } 164 165 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 166 { 167 u8 *ptid = (u8 *)data; 168 u8 *timer_to_id = ptid - *ptid; 169 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 170 timer_to_tid[0]); 171 172 rcu_read_lock(); 173 ieee80211_release_reorder_timeout(sta, *ptid); 174 rcu_read_unlock(); 175 } 176 177 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 178 u8 dialog_token, u16 status, u16 policy, 179 u16 buf_size, u16 timeout) 180 { 181 struct ieee80211_local *local = sdata->local; 182 struct sk_buff *skb; 183 struct ieee80211_mgmt *mgmt; 184 u16 capab; 185 186 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 187 if (!skb) 188 return; 189 190 skb_reserve(skb, local->hw.extra_tx_headroom); 191 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 192 memset(mgmt, 0, 24); 193 memcpy(mgmt->da, da, ETH_ALEN); 194 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 195 if (sdata->vif.type == NL80211_IFTYPE_AP || 196 sdata->vif.type == NL80211_IFTYPE_AP_VLAN || 197 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 198 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 199 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 200 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 201 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 202 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 203 204 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 205 IEEE80211_STYPE_ACTION); 206 207 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 208 mgmt->u.action.category = WLAN_CATEGORY_BACK; 209 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 210 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 211 212 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 213 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 214 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 215 216 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 217 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 218 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 219 220 ieee80211_tx_skb(sdata, skb); 221 } 222 223 void ieee80211_process_addba_request(struct ieee80211_local *local, 224 struct sta_info *sta, 225 struct ieee80211_mgmt *mgmt, 226 size_t len) 227 { 228 struct tid_ampdu_rx *tid_agg_rx; 229 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 230 u8 dialog_token; 231 int ret = -EOPNOTSUPP; 232 233 /* extract session parameters from addba request frame */ 234 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 235 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 236 start_seq_num = 237 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 238 239 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 240 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 241 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 242 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 243 244 status = WLAN_STATUS_REQUEST_DECLINED; 245 246 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 247 #ifdef CONFIG_MAC80211_HT_DEBUG 248 printk(KERN_DEBUG "Suspend in progress. " 249 "Denying ADDBA request\n"); 250 #endif 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 #ifdef CONFIG_MAC80211_HT_DEBUG 263 net_dbg_ratelimited("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 #endif /* CONFIG_MAC80211_HT_DEBUG */ 266 goto end_no_lock; 267 } 268 /* determine default buffer size */ 269 if (buf_size == 0) 270 buf_size = IEEE80211_MAX_AMPDU_BUF; 271 272 /* make sure the size doesn't exceed the maximum supported by the hw */ 273 if (buf_size > local->hw.max_rx_aggregation_subframes) 274 buf_size = local->hw.max_rx_aggregation_subframes; 275 276 /* examine state machine */ 277 mutex_lock(&sta->ampdu_mlme.mtx); 278 279 if (sta->ampdu_mlme.tid_rx[tid]) { 280 #ifdef CONFIG_MAC80211_HT_DEBUG 281 net_dbg_ratelimited("unexpected AddBA Req from %pM on tid %u\n", 282 mgmt->sa, tid); 283 #endif /* CONFIG_MAC80211_HT_DEBUG */ 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 = kmalloc(sizeof(struct tid_ampdu_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 *), 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 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 321 &sta->sta, tid, &start_seq_num, 0); 322 #ifdef CONFIG_MAC80211_HT_DEBUG 323 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret); 324 #endif /* CONFIG_MAC80211_HT_DEBUG */ 325 326 if (ret) { 327 kfree(tid_agg_rx->reorder_buf); 328 kfree(tid_agg_rx->reorder_time); 329 kfree(tid_agg_rx); 330 goto end; 331 } 332 333 /* update data */ 334 tid_agg_rx->dialog_token = dialog_token; 335 tid_agg_rx->ssn = start_seq_num; 336 tid_agg_rx->head_seq_num = start_seq_num; 337 tid_agg_rx->buf_size = buf_size; 338 tid_agg_rx->timeout = timeout; 339 tid_agg_rx->stored_mpdu_num = 0; 340 status = WLAN_STATUS_SUCCESS; 341 342 /* activate it for RX */ 343 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 344 345 if (timeout) { 346 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 347 tid_agg_rx->last_rx = jiffies; 348 } 349 350 end: 351 mutex_unlock(&sta->ampdu_mlme.mtx); 352 353 end_no_lock: 354 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 355 dialog_token, status, 1, buf_size, timeout); 356 } 357