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 <net/mac80211.h> 42 #include "ieee80211_i.h" 43 #include "driver-ops.h" 44 45 static void ieee80211_free_tid_rx(struct rcu_head *h) 46 { 47 struct tid_ampdu_rx *tid_rx = 48 container_of(h, struct tid_ampdu_rx, rcu_head); 49 int i; 50 51 for (i = 0; i < tid_rx->buf_size; i++) 52 dev_kfree_skb(tid_rx->reorder_buf[i]); 53 kfree(tid_rx->reorder_buf); 54 kfree(tid_rx->reorder_time); 55 kfree(tid_rx); 56 } 57 58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 59 u16 initiator, u16 reason, bool tx) 60 { 61 struct ieee80211_local *local = sta->local; 62 struct tid_ampdu_rx *tid_rx; 63 64 lockdep_assert_held(&sta->ampdu_mlme.mtx); 65 66 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid], 67 lockdep_is_held(&sta->ampdu_mlme.mtx)); 68 69 if (!tid_rx) 70 return; 71 72 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL); 73 74 #ifdef CONFIG_MAC80211_HT_DEBUG 75 printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n", 76 sta->sta.addr, tid); 77 #endif /* CONFIG_MAC80211_HT_DEBUG */ 78 79 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 80 &sta->sta, tid, NULL, 0)) 81 printk(KERN_DEBUG "HW problem - can not stop rx " 82 "aggregation for tid %d\n", tid); 83 84 /* check if this is a self generated aggregation halt */ 85 if (initiator == WLAN_BACK_RECIPIENT && tx) 86 ieee80211_send_delba(sta->sdata, sta->sta.addr, 87 tid, 0, reason); 88 89 del_timer_sync(&tid_rx->session_timer); 90 del_timer_sync(&tid_rx->reorder_timer); 91 92 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 93 } 94 95 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 96 u16 initiator, u16 reason, bool tx) 97 { 98 mutex_lock(&sta->ampdu_mlme.mtx); 99 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 100 mutex_unlock(&sta->ampdu_mlme.mtx); 101 } 102 103 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 104 const u8 *addr) 105 { 106 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 107 struct sta_info *sta; 108 int i; 109 110 rcu_read_lock(); 111 sta = sta_info_get(sdata, addr); 112 if (!sta) { 113 rcu_read_unlock(); 114 return; 115 } 116 117 for (i = 0; i < STA_TID_NUM; i++) 118 if (ba_rx_bitmap & BIT(i)) 119 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 120 121 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 122 rcu_read_unlock(); 123 } 124 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 125 126 /* 127 * After accepting the AddBA Request we activated a timer, 128 * resetting it after each frame that arrives from the originator. 129 */ 130 static void sta_rx_agg_session_timer_expired(unsigned long data) 131 { 132 /* not an elegant detour, but there is no choice as the timer passes 133 * only one argument, and various sta_info are needed here, so init 134 * flow in sta_info_create gives the TID as data, while the timer_to_id 135 * array gives the sta through container_of */ 136 u8 *ptid = (u8 *)data; 137 u8 *timer_to_id = ptid - *ptid; 138 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 139 timer_to_tid[0]); 140 141 #ifdef CONFIG_MAC80211_HT_DEBUG 142 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid); 143 #endif 144 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 145 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 146 } 147 148 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 149 { 150 u8 *ptid = (u8 *)data; 151 u8 *timer_to_id = ptid - *ptid; 152 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 153 timer_to_tid[0]); 154 155 rcu_read_lock(); 156 ieee80211_release_reorder_timeout(sta, *ptid); 157 rcu_read_unlock(); 158 } 159 160 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 161 u8 dialog_token, u16 status, u16 policy, 162 u16 buf_size, u16 timeout) 163 { 164 struct ieee80211_local *local = sdata->local; 165 struct sk_buff *skb; 166 struct ieee80211_mgmt *mgmt; 167 u16 capab; 168 169 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 170 171 if (!skb) { 172 printk(KERN_DEBUG "%s: failed to allocate buffer " 173 "for addba resp frame\n", sdata->name); 174 return; 175 } 176 177 skb_reserve(skb, local->hw.extra_tx_headroom); 178 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 179 memset(mgmt, 0, 24); 180 memcpy(mgmt->da, da, ETH_ALEN); 181 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 182 if (sdata->vif.type == NL80211_IFTYPE_AP || 183 sdata->vif.type == NL80211_IFTYPE_AP_VLAN) 184 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 185 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 186 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 187 188 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 189 IEEE80211_STYPE_ACTION); 190 191 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 192 mgmt->u.action.category = WLAN_CATEGORY_BACK; 193 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 194 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 195 196 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 197 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 198 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 199 200 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 201 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 202 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 203 204 ieee80211_tx_skb(sdata, skb); 205 } 206 207 void ieee80211_process_addba_request(struct ieee80211_local *local, 208 struct sta_info *sta, 209 struct ieee80211_mgmt *mgmt, 210 size_t len) 211 { 212 struct tid_ampdu_rx *tid_agg_rx; 213 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 214 u8 dialog_token; 215 int ret = -EOPNOTSUPP; 216 217 /* extract session parameters from addba request frame */ 218 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 219 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 220 start_seq_num = 221 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 222 223 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 224 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 225 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 226 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 227 228 status = WLAN_STATUS_REQUEST_DECLINED; 229 230 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) { 231 #ifdef CONFIG_MAC80211_HT_DEBUG 232 printk(KERN_DEBUG "Suspend in progress. " 233 "Denying ADDBA request\n"); 234 #endif 235 goto end_no_lock; 236 } 237 238 /* sanity check for incoming parameters: 239 * check if configuration can support the BA policy 240 * and if buffer size does not exceeds max value */ 241 /* XXX: check own ht delayed BA capability?? */ 242 if (((ba_policy != 1) && 243 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 244 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 245 status = WLAN_STATUS_INVALID_QOS_PARAM; 246 #ifdef CONFIG_MAC80211_HT_DEBUG 247 if (net_ratelimit()) 248 printk(KERN_DEBUG "AddBA Req with bad params from " 249 "%pM on tid %u. policy %d, buffer size %d\n", 250 mgmt->sa, tid, ba_policy, 251 buf_size); 252 #endif /* CONFIG_MAC80211_HT_DEBUG */ 253 goto end_no_lock; 254 } 255 /* determine default buffer size */ 256 if (buf_size == 0) 257 buf_size = IEEE80211_MAX_AMPDU_BUF; 258 259 /* make sure the size doesn't exceed the maximum supported by the hw */ 260 if (buf_size > local->hw.max_rx_aggregation_subframes) 261 buf_size = local->hw.max_rx_aggregation_subframes; 262 263 /* examine state machine */ 264 mutex_lock(&sta->ampdu_mlme.mtx); 265 266 if (sta->ampdu_mlme.tid_rx[tid]) { 267 #ifdef CONFIG_MAC80211_HT_DEBUG 268 if (net_ratelimit()) 269 printk(KERN_DEBUG "unexpected AddBA Req from " 270 "%pM on tid %u\n", 271 mgmt->sa, tid); 272 #endif /* CONFIG_MAC80211_HT_DEBUG */ 273 274 /* delete existing Rx BA session on the same tid */ 275 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 276 WLAN_STATUS_UNSPECIFIED_QOS, 277 false); 278 } 279 280 /* prepare A-MPDU MLME for Rx aggregation */ 281 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 282 if (!tid_agg_rx) { 283 #ifdef CONFIG_MAC80211_HT_DEBUG 284 if (net_ratelimit()) 285 printk(KERN_ERR "allocate rx mlme to tid %d failed\n", 286 tid); 287 #endif 288 goto end; 289 } 290 291 spin_lock_init(&tid_agg_rx->reorder_lock); 292 293 /* rx timer */ 294 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 295 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 296 init_timer(&tid_agg_rx->session_timer); 297 298 /* rx reorder timer */ 299 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 300 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 301 init_timer(&tid_agg_rx->reorder_timer); 302 303 /* prepare reordering buffer */ 304 tid_agg_rx->reorder_buf = 305 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL); 306 tid_agg_rx->reorder_time = 307 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 308 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 309 #ifdef CONFIG_MAC80211_HT_DEBUG 310 if (net_ratelimit()) 311 printk(KERN_ERR "can not allocate reordering buffer " 312 "to tid %d\n", tid); 313 #endif 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)); 347 348 end: 349 mutex_unlock(&sta->ampdu_mlme.mtx); 350 351 end_no_lock: 352 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 353 dialog_token, status, 1, buf_size, timeout); 354 } 355