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