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 dev_kfree_skb(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 #ifdef CONFIG_MAC80211_HT_DEBUG 76 printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n", 77 sta->sta.addr, tid); 78 #endif /* CONFIG_MAC80211_HT_DEBUG */ 79 80 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 81 &sta->sta, tid, NULL, 0)) 82 printk(KERN_DEBUG "HW problem - can not stop rx " 83 "aggregation for tid %d\n", tid); 84 85 /* check if this is a self generated aggregation halt */ 86 if (initiator == WLAN_BACK_RECIPIENT && tx) 87 ieee80211_send_delba(sta->sdata, sta->sta.addr, 88 tid, 0, reason); 89 90 del_timer_sync(&tid_rx->session_timer); 91 del_timer_sync(&tid_rx->reorder_timer); 92 93 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 94 } 95 96 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 97 u16 initiator, u16 reason, bool tx) 98 { 99 mutex_lock(&sta->ampdu_mlme.mtx); 100 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 101 mutex_unlock(&sta->ampdu_mlme.mtx); 102 } 103 104 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 105 const u8 *addr) 106 { 107 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 108 struct sta_info *sta; 109 int i; 110 111 rcu_read_lock(); 112 sta = sta_info_get(sdata, addr); 113 if (!sta) { 114 rcu_read_unlock(); 115 return; 116 } 117 118 for (i = 0; i < STA_TID_NUM; i++) 119 if (ba_rx_bitmap & BIT(i)) 120 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 121 122 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 123 rcu_read_unlock(); 124 } 125 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 126 127 /* 128 * After accepting the AddBA Request we activated a timer, 129 * resetting it after each frame that arrives from the originator. 130 */ 131 static void sta_rx_agg_session_timer_expired(unsigned long data) 132 { 133 /* not an elegant detour, but there is no choice as the timer passes 134 * only one argument, and various sta_info are needed here, so init 135 * flow in sta_info_create gives the TID as data, while the timer_to_id 136 * array gives the sta through container_of */ 137 u8 *ptid = (u8 *)data; 138 u8 *timer_to_id = ptid - *ptid; 139 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 140 timer_to_tid[0]); 141 142 #ifdef CONFIG_MAC80211_HT_DEBUG 143 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid); 144 #endif 145 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 146 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 147 } 148 149 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 150 { 151 u8 *ptid = (u8 *)data; 152 u8 *timer_to_id = ptid - *ptid; 153 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 154 timer_to_tid[0]); 155 156 rcu_read_lock(); 157 ieee80211_release_reorder_timeout(sta, *ptid); 158 rcu_read_unlock(); 159 } 160 161 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 162 u8 dialog_token, u16 status, u16 policy, 163 u16 buf_size, u16 timeout) 164 { 165 struct ieee80211_local *local = sdata->local; 166 struct sk_buff *skb; 167 struct ieee80211_mgmt *mgmt; 168 u16 capab; 169 170 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 171 if (!skb) 172 return; 173 174 skb_reserve(skb, local->hw.extra_tx_headroom); 175 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 176 memset(mgmt, 0, 24); 177 memcpy(mgmt->da, da, ETH_ALEN); 178 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 179 if (sdata->vif.type == NL80211_IFTYPE_AP || 180 sdata->vif.type == NL80211_IFTYPE_AP_VLAN) 181 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 182 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 183 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 184 185 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 186 IEEE80211_STYPE_ACTION); 187 188 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 189 mgmt->u.action.category = WLAN_CATEGORY_BACK; 190 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 191 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 192 193 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 194 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 195 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 196 197 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 198 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 199 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 200 201 ieee80211_tx_skb(sdata, skb); 202 } 203 204 void ieee80211_process_addba_request(struct ieee80211_local *local, 205 struct sta_info *sta, 206 struct ieee80211_mgmt *mgmt, 207 size_t len) 208 { 209 struct tid_ampdu_rx *tid_agg_rx; 210 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 211 u8 dialog_token; 212 int ret = -EOPNOTSUPP; 213 214 /* extract session parameters from addba request frame */ 215 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 216 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 217 start_seq_num = 218 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 219 220 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 221 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 222 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 223 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 224 225 status = WLAN_STATUS_REQUEST_DECLINED; 226 227 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 228 #ifdef CONFIG_MAC80211_HT_DEBUG 229 printk(KERN_DEBUG "Suspend in progress. " 230 "Denying ADDBA request\n"); 231 #endif 232 goto end_no_lock; 233 } 234 235 /* sanity check for incoming parameters: 236 * check if configuration can support the BA policy 237 * and if buffer size does not exceeds max value */ 238 /* XXX: check own ht delayed BA capability?? */ 239 if (((ba_policy != 1) && 240 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 241 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 242 status = WLAN_STATUS_INVALID_QOS_PARAM; 243 #ifdef CONFIG_MAC80211_HT_DEBUG 244 if (net_ratelimit()) 245 printk(KERN_DEBUG "AddBA Req with bad params from " 246 "%pM on tid %u. policy %d, buffer size %d\n", 247 mgmt->sa, tid, ba_policy, 248 buf_size); 249 #endif /* CONFIG_MAC80211_HT_DEBUG */ 250 goto end_no_lock; 251 } 252 /* determine default buffer size */ 253 if (buf_size == 0) 254 buf_size = IEEE80211_MAX_AMPDU_BUF; 255 256 /* make sure the size doesn't exceed the maximum supported by the hw */ 257 if (buf_size > local->hw.max_rx_aggregation_subframes) 258 buf_size = local->hw.max_rx_aggregation_subframes; 259 260 /* examine state machine */ 261 mutex_lock(&sta->ampdu_mlme.mtx); 262 263 if (sta->ampdu_mlme.tid_rx[tid]) { 264 #ifdef CONFIG_MAC80211_HT_DEBUG 265 if (net_ratelimit()) 266 printk(KERN_DEBUG "unexpected AddBA Req from " 267 "%pM on tid %u\n", 268 mgmt->sa, tid); 269 #endif /* CONFIG_MAC80211_HT_DEBUG */ 270 271 /* delete existing Rx BA session on the same tid */ 272 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 273 WLAN_STATUS_UNSPECIFIED_QOS, 274 false); 275 } 276 277 /* prepare A-MPDU MLME for Rx aggregation */ 278 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 279 if (!tid_agg_rx) 280 goto end; 281 282 spin_lock_init(&tid_agg_rx->reorder_lock); 283 284 /* rx timer */ 285 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 286 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 287 init_timer(&tid_agg_rx->session_timer); 288 289 /* rx reorder timer */ 290 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 291 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 292 init_timer(&tid_agg_rx->reorder_timer); 293 294 /* prepare reordering buffer */ 295 tid_agg_rx->reorder_buf = 296 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL); 297 tid_agg_rx->reorder_time = 298 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 299 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 300 kfree(tid_agg_rx->reorder_buf); 301 kfree(tid_agg_rx->reorder_time); 302 kfree(tid_agg_rx); 303 goto end; 304 } 305 306 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 307 &sta->sta, tid, &start_seq_num, 0); 308 #ifdef CONFIG_MAC80211_HT_DEBUG 309 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret); 310 #endif /* CONFIG_MAC80211_HT_DEBUG */ 311 312 if (ret) { 313 kfree(tid_agg_rx->reorder_buf); 314 kfree(tid_agg_rx->reorder_time); 315 kfree(tid_agg_rx); 316 goto end; 317 } 318 319 /* update data */ 320 tid_agg_rx->dialog_token = dialog_token; 321 tid_agg_rx->ssn = start_seq_num; 322 tid_agg_rx->head_seq_num = start_seq_num; 323 tid_agg_rx->buf_size = buf_size; 324 tid_agg_rx->timeout = timeout; 325 tid_agg_rx->stored_mpdu_num = 0; 326 status = WLAN_STATUS_SUCCESS; 327 328 /* activate it for RX */ 329 RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 330 331 if (timeout) 332 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 333 334 end: 335 mutex_unlock(&sta->ampdu_mlme.mtx); 336 337 end_no_lock: 338 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 339 dialog_token, status, 1, buf_size, timeout); 340 } 341