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 77 "Rx BA session stop requested for %pM tid %u %s reason: %d\n", 78 sta->sta.addr, tid, 79 initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator", 80 (int)reason); 81 #endif /* CONFIG_MAC80211_HT_DEBUG */ 82 83 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP, 84 &sta->sta, tid, NULL, 0)) 85 printk(KERN_DEBUG "HW problem - can not stop rx " 86 "aggregation for tid %d\n", tid); 87 88 /* check if this is a self generated aggregation halt */ 89 if (initiator == WLAN_BACK_RECIPIENT && tx) 90 ieee80211_send_delba(sta->sdata, sta->sta.addr, 91 tid, WLAN_BACK_RECIPIENT, reason); 92 93 del_timer_sync(&tid_rx->session_timer); 94 del_timer_sync(&tid_rx->reorder_timer); 95 96 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); 97 } 98 99 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, 100 u16 initiator, u16 reason, bool tx) 101 { 102 mutex_lock(&sta->ampdu_mlme.mtx); 103 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx); 104 mutex_unlock(&sta->ampdu_mlme.mtx); 105 } 106 107 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap, 108 const u8 *addr) 109 { 110 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 111 struct sta_info *sta; 112 int i; 113 114 rcu_read_lock(); 115 sta = sta_info_get_bss(sdata, addr); 116 if (!sta) { 117 rcu_read_unlock(); 118 return; 119 } 120 121 for (i = 0; i < STA_TID_NUM; i++) 122 if (ba_rx_bitmap & BIT(i)) 123 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested); 124 125 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 126 rcu_read_unlock(); 127 } 128 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session); 129 130 /* 131 * After accepting the AddBA Request we activated a timer, 132 * resetting it after each frame that arrives from the originator. 133 */ 134 static void sta_rx_agg_session_timer_expired(unsigned long data) 135 { 136 /* not an elegant detour, but there is no choice as the timer passes 137 * only one argument, and various sta_info are needed here, so init 138 * flow in sta_info_create gives the TID as data, while the timer_to_id 139 * array gives the sta through container_of */ 140 u8 *ptid = (u8 *)data; 141 u8 *timer_to_id = ptid - *ptid; 142 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 143 timer_to_tid[0]); 144 145 #ifdef CONFIG_MAC80211_HT_DEBUG 146 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid); 147 #endif 148 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired); 149 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work); 150 } 151 152 static void sta_rx_agg_reorder_timer_expired(unsigned long data) 153 { 154 u8 *ptid = (u8 *)data; 155 u8 *timer_to_id = ptid - *ptid; 156 struct sta_info *sta = container_of(timer_to_id, struct sta_info, 157 timer_to_tid[0]); 158 159 rcu_read_lock(); 160 ieee80211_release_reorder_timeout(sta, *ptid); 161 rcu_read_unlock(); 162 } 163 164 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid, 165 u8 dialog_token, u16 status, u16 policy, 166 u16 buf_size, u16 timeout) 167 { 168 struct ieee80211_local *local = sdata->local; 169 struct sk_buff *skb; 170 struct ieee80211_mgmt *mgmt; 171 u16 capab; 172 173 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); 174 if (!skb) 175 return; 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 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 185 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 186 else if (sdata->vif.type == NL80211_IFTYPE_STATION) 187 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); 188 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) 189 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); 190 191 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 192 IEEE80211_STYPE_ACTION); 193 194 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp)); 195 mgmt->u.action.category = WLAN_CATEGORY_BACK; 196 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP; 197 mgmt->u.action.u.addba_resp.dialog_token = dialog_token; 198 199 capab = (u16)(policy << 1); /* bit 1 aggregation policy */ 200 capab |= (u16)(tid << 2); /* bit 5:2 TID number */ 201 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */ 202 203 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab); 204 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout); 205 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status); 206 207 ieee80211_tx_skb(sdata, skb); 208 } 209 210 void ieee80211_process_addba_request(struct ieee80211_local *local, 211 struct sta_info *sta, 212 struct ieee80211_mgmt *mgmt, 213 size_t len) 214 { 215 struct tid_ampdu_rx *tid_agg_rx; 216 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status; 217 u8 dialog_token; 218 int ret = -EOPNOTSUPP; 219 220 /* extract session parameters from addba request frame */ 221 dialog_token = mgmt->u.action.u.addba_req.dialog_token; 222 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout); 223 start_seq_num = 224 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4; 225 226 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab); 227 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1; 228 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; 229 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; 230 231 status = WLAN_STATUS_REQUEST_DECLINED; 232 233 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { 234 #ifdef CONFIG_MAC80211_HT_DEBUG 235 printk(KERN_DEBUG "Suspend in progress. " 236 "Denying ADDBA request\n"); 237 #endif 238 goto end_no_lock; 239 } 240 241 /* sanity check for incoming parameters: 242 * check if configuration can support the BA policy 243 * and if buffer size does not exceeds max value */ 244 /* XXX: check own ht delayed BA capability?? */ 245 if (((ba_policy != 1) && 246 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || 247 (buf_size > IEEE80211_MAX_AMPDU_BUF)) { 248 status = WLAN_STATUS_INVALID_QOS_PARAM; 249 #ifdef CONFIG_MAC80211_HT_DEBUG 250 if (net_ratelimit()) 251 printk(KERN_DEBUG "AddBA Req with bad params from " 252 "%pM on tid %u. policy %d, buffer size %d\n", 253 mgmt->sa, tid, ba_policy, 254 buf_size); 255 #endif /* CONFIG_MAC80211_HT_DEBUG */ 256 goto end_no_lock; 257 } 258 /* determine default buffer size */ 259 if (buf_size == 0) 260 buf_size = IEEE80211_MAX_AMPDU_BUF; 261 262 /* make sure the size doesn't exceed the maximum supported by the hw */ 263 if (buf_size > local->hw.max_rx_aggregation_subframes) 264 buf_size = local->hw.max_rx_aggregation_subframes; 265 266 /* examine state machine */ 267 mutex_lock(&sta->ampdu_mlme.mtx); 268 269 if (sta->ampdu_mlme.tid_rx[tid]) { 270 #ifdef CONFIG_MAC80211_HT_DEBUG 271 if (net_ratelimit()) 272 printk(KERN_DEBUG "unexpected AddBA Req from " 273 "%pM on tid %u\n", 274 mgmt->sa, tid); 275 #endif /* CONFIG_MAC80211_HT_DEBUG */ 276 277 /* delete existing Rx BA session on the same tid */ 278 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT, 279 WLAN_STATUS_UNSPECIFIED_QOS, 280 false); 281 } 282 283 /* prepare A-MPDU MLME for Rx aggregation */ 284 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL); 285 if (!tid_agg_rx) 286 goto end; 287 288 spin_lock_init(&tid_agg_rx->reorder_lock); 289 290 /* rx timer */ 291 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired; 292 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 293 init_timer(&tid_agg_rx->session_timer); 294 295 /* rx reorder timer */ 296 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired; 297 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid]; 298 init_timer(&tid_agg_rx->reorder_timer); 299 300 /* prepare reordering buffer */ 301 tid_agg_rx->reorder_buf = 302 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL); 303 tid_agg_rx->reorder_time = 304 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL); 305 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { 306 kfree(tid_agg_rx->reorder_buf); 307 kfree(tid_agg_rx->reorder_time); 308 kfree(tid_agg_rx); 309 goto end; 310 } 311 312 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START, 313 &sta->sta, tid, &start_seq_num, 0); 314 #ifdef CONFIG_MAC80211_HT_DEBUG 315 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret); 316 #endif /* CONFIG_MAC80211_HT_DEBUG */ 317 318 if (ret) { 319 kfree(tid_agg_rx->reorder_buf); 320 kfree(tid_agg_rx->reorder_time); 321 kfree(tid_agg_rx); 322 goto end; 323 } 324 325 /* update data */ 326 tid_agg_rx->dialog_token = dialog_token; 327 tid_agg_rx->ssn = start_seq_num; 328 tid_agg_rx->head_seq_num = start_seq_num; 329 tid_agg_rx->buf_size = buf_size; 330 tid_agg_rx->timeout = timeout; 331 tid_agg_rx->stored_mpdu_num = 0; 332 status = WLAN_STATUS_SUCCESS; 333 334 /* activate it for RX */ 335 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx); 336 337 if (timeout) 338 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout)); 339 340 end: 341 mutex_unlock(&sta->ampdu_mlme.mtx); 342 343 end_no_lock: 344 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid, 345 dialog_token, status, 1, buf_size, timeout); 346 } 347