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 = sta->ampdu_mlme.tid_rx[tid]; 67 68 if (!tid_rx) 69 return; 70 71 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL); 72 73 #ifdef CONFIG_MAC80211_HT_DEBUG 74 printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n", 75 sta->sta.addr, tid); 76 #endif /* CONFIG_MAC80211_HT_DEBUG */ 77 78 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 79 &sta->sta, tid, NULL)) 80 printk(KERN_DEBUG "HW problem - can not stop rx " 81 "aggregation for tid %d\n", tid); 82 83 /* check if this is a self generated aggregation halt */ 84 if (initiator == WLAN_BACK_RECIPIENT && tx) 85 ieee80211_send_delba(sta->sdata, sta->sta.addr, 86 tid, 0, reason); 87 88 del_timer_sync(&tid_rx->session_timer); 89 del_timer_sync(&tid_rx->reorder_timer); 90 91 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 92 } 93 94 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 95 u16 initiator, u16 reason, bool tx) 96 { 97 mutex_lock(&sta->ampdu_mlme.mtx); 98 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 99 mutex_unlock(&sta->ampdu_mlme.mtx); 100 } 101 102 /* 103 * After accepting the AddBA Request we activated a timer, 104 * resetting it after each frame that arrives from the originator. 105 */ 106 static void sta_rx_agg_session_timer_expired(unsigned long data) 107 { 108 /* not an elegant detour, but there is no choice as the timer passes 109 * only one argument, and various sta_info are needed here, so init 110 * flow in sta_info_create gives the TID as data, while the timer_to_id 111 * array gives the sta through container_of */ 112 u8 *ptid = (u8 *)data; 113 u8 *timer_to_id = ptid - *ptid; 114 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 115 timer_to_tid[0]); 116 117 #ifdef CONFIG_MAC80211_HT_DEBUG 118 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid); 119 #endif 120 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 121 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 122 } 123 124 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 125 { 126 u8 *ptid = (u8 *)data; 127 u8 *timer_to_id = ptid - *ptid; 128 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 129 timer_to_tid[0]); 130 131 rcu_read_lock(); 132 ieee80211_release_reorder_timeout(sta, *ptid); 133 rcu_read_unlock(); 134 } 135 136 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 137 u8 dialog_token, u16 status, u16 policy, 138 u16 buf_size, u16 timeout) 139 { 140 struct ieee80211_local *local = sdata->local; 141 struct sk_buff *skb; 142 struct ieee80211_mgmt *mgmt; 143 u16 capab; 144 145 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 146 147 if (!skb) { 148 printk(KERN_DEBUG "%s: failed to allocate buffer " 149 "for addba resp frame\n", sdata->name); 150 return; 151 } 152 153 skb_reserve(skb, local->hw.extra_tx_headroom); 154 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); 155 memset(mgmt, 0, 24); 156 memcpy(mgmt->da, da, ETH_ALEN); 157 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 158 if (sdata->vif.type == NL80211_IFTYPE_AP || 159 sdata->vif.type == NL80211_IFTYPE_AP_VLAN) 160 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 161 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 162 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 163 164 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 165 IEEE80211_STYPE_ACTION); 166 167 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 168 mgmt->u.action.category = WLAN_CATEGORY_BACK; 169 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 170 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 171 172 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 173 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 174 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 175 176 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 177 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 178 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 179 180 ieee80211_tx_skb(sdata, skb); 181 } 182 183 void ieee80211_process_addba_request(struct ieee80211_local *local, 184 struct sta_info *sta, 185 struct ieee80211_mgmt *mgmt, 186 size_t len) 187 { 188 struct ieee80211_hw *hw = &local->hw; 189 struct ieee80211_conf *conf = &hw->conf; 190 struct tid_ampdu_rx *tid_agg_rx; 191 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 192 u8 dialog_token; 193 int ret = -EOPNOTSUPP; 194 195 /* extract session parameters from addba request frame */ 196 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 197 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 198 start_seq_num = 199 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 200 201 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 202 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 203 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 204 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 205 206 status = WLAN_STATUS_REQUEST_DECLINED; 207 208 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) { 209 #ifdef CONFIG_MAC80211_HT_DEBUG 210 printk(KERN_DEBUG "Suspend in progress. " 211 "Denying ADDBA request\n"); 212 #endif 213 goto end_no_lock; 214 } 215 216 /* sanity check for incoming parameters: 217 * check if configuration can support the BA policy 218 * and if buffer size does not exceeds max value */ 219 /* XXX: check own ht delayed BA capability?? */ 220 if (((ba_policy != 1) && 221 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 222 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 223 status = WLAN_STATUS_INVALID_QOS_PARAM; 224 #ifdef CONFIG_MAC80211_HT_DEBUG 225 if (net_ratelimit()) 226 printk(KERN_DEBUG "AddBA Req with bad params from " 227 "%pM on tid %u. policy %d, buffer size %d\n", 228 mgmt->sa, tid, ba_policy, 229 buf_size); 230 #endif /* CONFIG_MAC80211_HT_DEBUG */ 231 goto end_no_lock; 232 } 233 /* determine default buffer size */ 234 if (buf_size == 0) { 235 struct ieee80211_supported_band *sband; 236 237 sband = local->hw.wiphy->bands[conf->channel->band]; 238 buf_size = IEEE80211_MIN_AMPDU_BUF; 239 buf_size = buf_size << sband->ht_cap.ampdu_factor; 240 } 241 242 243 /* examine state machine */ 244 mutex_lock(&sta->ampdu_mlme.mtx); 245 246 if (sta->ampdu_mlme.tid_rx[tid]) { 247 #ifdef CONFIG_MAC80211_HT_DEBUG 248 if (net_ratelimit()) 249 printk(KERN_DEBUG "unexpected AddBA Req from " 250 "%pM on tid %u\n", 251 mgmt->sa, tid); 252 #endif /* CONFIG_MAC80211_HT_DEBUG */ 253 goto end; 254 } 255 256 /* prepare A-MPDU MLME for Rx aggregation */ 257 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 258 if (!tid_agg_rx) { 259 #ifdef CONFIG_MAC80211_HT_DEBUG 260 if (net_ratelimit()) 261 printk(KERN_ERR "allocate rx mlme to tid %d failed\n", 262 tid); 263 #endif 264 goto end; 265 } 266 267 spin_lock_init(&tid_agg_rx->reorder_lock); 268 269 /* rx timer */ 270 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 271 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 272 init_timer(&tid_agg_rx->session_timer); 273 274 /* rx reorder timer */ 275 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 276 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 277 init_timer(&tid_agg_rx->reorder_timer); 278 279 /* prepare reordering buffer */ 280 tid_agg_rx->reorder_buf = 281 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL); 282 tid_agg_rx->reorder_time = 283 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 284 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 285 #ifdef CONFIG_MAC80211_HT_DEBUG 286 if (net_ratelimit()) 287 printk(KERN_ERR "can not allocate reordering buffer " 288 "to tid %d\n", tid); 289 #endif 290 kfree(tid_agg_rx->reorder_buf); 291 kfree(tid_agg_rx->reorder_time); 292 kfree(tid_agg_rx); 293 goto end; 294 } 295 296 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 297 &sta->sta, tid, &start_seq_num); 298 #ifdef CONFIG_MAC80211_HT_DEBUG 299 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret); 300 #endif /* CONFIG_MAC80211_HT_DEBUG */ 301 302 if (ret) { 303 kfree(tid_agg_rx->reorder_buf); 304 kfree(tid_agg_rx->reorder_time); 305 kfree(tid_agg_rx); 306 goto end; 307 } 308 309 /* update data */ 310 tid_agg_rx->dialog_token = dialog_token; 311 tid_agg_rx->ssn = start_seq_num; 312 tid_agg_rx->head_seq_num = start_seq_num; 313 tid_agg_rx->buf_size = buf_size; 314 tid_agg_rx->timeout = timeout; 315 tid_agg_rx->stored_mpdu_num = 0; 316 status = WLAN_STATUS_SUCCESS; 317 318 /* activate it for RX */ 319 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 320 321 if (timeout) 322 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 323 324 end: 325 mutex_unlock(&sta->ampdu_mlme.mtx); 326 327 end_no_lock: 328 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 329 dialog_token, status, 1, buf_size, timeout); 330 } 331