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