1 /* 2 * Copyright 2002-2005, Instant802 Networks, Inc. 3 * Copyright 2005-2006, Devicescape Software, Inc. 4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 5 * Copyright 2008-2010 Johannes Berg <johannes@sipsolutions.net> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <net/mac80211.h> 13 #include "ieee80211_i.h" 14 #include "rate.h" 15 #include "mesh.h" 16 #include "led.h" 17 18 19 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw, 20 struct sk_buff *skb) 21 { 22 struct ieee80211_local *local = hw_to_local(hw); 23 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 24 int tmp; 25 26 skb->pkt_type = IEEE80211_TX_STATUS_MSG; 27 skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ? 28 &local->skb_queue : &local->skb_queue_unreliable, skb); 29 tmp = skb_queue_len(&local->skb_queue) + 30 skb_queue_len(&local->skb_queue_unreliable); 31 while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT && 32 (skb = skb_dequeue(&local->skb_queue_unreliable))) { 33 dev_kfree_skb_irq(skb); 34 tmp--; 35 I802_DEBUG_INC(local->tx_status_drop); 36 } 37 tasklet_schedule(&local->tasklet); 38 } 39 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe); 40 41 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local, 42 struct sta_info *sta, 43 struct sk_buff *skb) 44 { 45 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 46 47 /* 48 * This skb 'survived' a round-trip through the driver, and 49 * hopefully the driver didn't mangle it too badly. However, 50 * we can definitely not rely on the control information 51 * being correct. Clear it so we don't get junk there, and 52 * indicate that it needs new processing, but must not be 53 * modified/encrypted again. 54 */ 55 memset(&info->control, 0, sizeof(info->control)); 56 57 info->control.jiffies = jiffies; 58 info->control.vif = &sta->sdata->vif; 59 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING | 60 IEEE80211_TX_INTFL_RETRANSMISSION; 61 info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS; 62 63 sta->tx_filtered_count++; 64 65 /* 66 * Clear the TX filter mask for this STA when sending the next 67 * packet. If the STA went to power save mode, this will happen 68 * when it wakes up for the next time. 69 */ 70 set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT); 71 72 /* 73 * This code races in the following way: 74 * 75 * (1) STA sends frame indicating it will go to sleep and does so 76 * (2) hardware/firmware adds STA to filter list, passes frame up 77 * (3) hardware/firmware processes TX fifo and suppresses a frame 78 * (4) we get TX status before having processed the frame and 79 * knowing that the STA has gone to sleep. 80 * 81 * This is actually quite unlikely even when both those events are 82 * processed from interrupts coming in quickly after one another or 83 * even at the same time because we queue both TX status events and 84 * RX frames to be processed by a tasklet and process them in the 85 * same order that they were received or TX status last. Hence, there 86 * is no race as long as the frame RX is processed before the next TX 87 * status, which drivers can ensure, see below. 88 * 89 * Note that this can only happen if the hardware or firmware can 90 * actually add STAs to the filter list, if this is done by the 91 * driver in response to set_tim() (which will only reduce the race 92 * this whole filtering tries to solve, not completely solve it) 93 * this situation cannot happen. 94 * 95 * To completely solve this race drivers need to make sure that they 96 * (a) don't mix the irq-safe/not irq-safe TX status/RX processing 97 * functions and 98 * (b) always process RX events before TX status events if ordering 99 * can be unknown, for example with different interrupt status 100 * bits. 101 */ 102 if (test_sta_flags(sta, WLAN_STA_PS_STA) && 103 skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) { 104 skb_queue_tail(&sta->tx_filtered, skb); 105 return; 106 } 107 108 if (!test_sta_flags(sta, WLAN_STA_PS_STA) && 109 !(info->flags & IEEE80211_TX_INTFL_RETRIED)) { 110 /* Software retry the packet once */ 111 info->flags |= IEEE80211_TX_INTFL_RETRIED; 112 ieee80211_add_pending_skb(local, skb); 113 return; 114 } 115 116 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 117 if (net_ratelimit()) 118 wiphy_debug(local->hw.wiphy, 119 "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n", 120 skb_queue_len(&sta->tx_filtered), 121 !!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies); 122 #endif 123 dev_kfree_skb(skb); 124 } 125 126 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb) 127 { 128 struct ieee80211_mgmt *mgmt = (void *) skb->data; 129 struct ieee80211_local *local = sta->local; 130 struct ieee80211_sub_if_data *sdata = sta->sdata; 131 132 if (ieee80211_is_action(mgmt->frame_control) && 133 sdata->vif.type == NL80211_IFTYPE_STATION && 134 mgmt->u.action.category == WLAN_CATEGORY_HT && 135 mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) { 136 /* 137 * This update looks racy, but isn't -- if we come 138 * here we've definitely got a station that we're 139 * talking to, and on a managed interface that can 140 * only be the AP. And the only other place updating 141 * this variable is before we're associated. 142 */ 143 switch (mgmt->u.action.u.ht_smps.smps_control) { 144 case WLAN_HT_SMPS_CONTROL_DYNAMIC: 145 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC; 146 break; 147 case WLAN_HT_SMPS_CONTROL_STATIC: 148 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC; 149 break; 150 case WLAN_HT_SMPS_CONTROL_DISABLED: 151 default: /* shouldn't happen since we don't send that */ 152 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF; 153 break; 154 } 155 156 ieee80211_queue_work(&local->hw, &local->recalc_smps); 157 } 158 } 159 160 /* 161 * Use a static threshold for now, best value to be determined 162 * by testing ... 163 * Should it depend on: 164 * - on # of retransmissions 165 * - current throughput (higher value for higher tpt)? 166 */ 167 #define STA_LOST_PKT_THRESHOLD 50 168 169 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) 170 { 171 struct sk_buff *skb2; 172 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 173 struct ieee80211_local *local = hw_to_local(hw); 174 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 175 u16 frag, type; 176 __le16 fc; 177 struct ieee80211_supported_band *sband; 178 struct ieee80211_tx_status_rtap_hdr *rthdr; 179 struct ieee80211_sub_if_data *sdata; 180 struct net_device *prev_dev = NULL; 181 struct sta_info *sta, *tmp; 182 int retry_count = -1, i; 183 int rates_idx = -1; 184 bool send_to_cooked; 185 bool acked; 186 187 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 188 /* the HW cannot have attempted that rate */ 189 if (i >= hw->max_report_rates) { 190 info->status.rates[i].idx = -1; 191 info->status.rates[i].count = 0; 192 } else if (info->status.rates[i].idx >= 0) { 193 rates_idx = i; 194 } 195 196 retry_count += info->status.rates[i].count; 197 } 198 if (retry_count < 0) 199 retry_count = 0; 200 201 rcu_read_lock(); 202 203 sband = local->hw.wiphy->bands[info->band]; 204 fc = hdr->frame_control; 205 206 for_each_sta_info(local, hdr->addr1, sta, tmp) { 207 /* skip wrong virtual interface */ 208 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN)) 209 continue; 210 211 acked = !!(info->flags & IEEE80211_TX_STAT_ACK); 212 if (!acked && test_sta_flags(sta, WLAN_STA_PS_STA)) { 213 /* 214 * The STA is in power save mode, so assume 215 * that this TX packet failed because of that. 216 */ 217 ieee80211_handle_filtered_frame(local, sta, skb); 218 rcu_read_unlock(); 219 return; 220 } 221 222 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) && 223 (rates_idx != -1)) 224 sta->last_tx_rate = info->status.rates[rates_idx]; 225 226 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) && 227 (ieee80211_is_data_qos(fc))) { 228 u16 tid, ssn; 229 u8 *qc; 230 231 qc = ieee80211_get_qos_ctl(hdr); 232 tid = qc[0] & 0xf; 233 ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10) 234 & IEEE80211_SCTL_SEQ); 235 ieee80211_send_bar(sta->sdata, hdr->addr1, 236 tid, ssn); 237 } 238 239 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) { 240 ieee80211_handle_filtered_frame(local, sta, skb); 241 rcu_read_unlock(); 242 return; 243 } else { 244 if (!acked) 245 sta->tx_retry_failed++; 246 sta->tx_retry_count += retry_count; 247 } 248 249 rate_control_tx_status(local, sband, sta, skb); 250 if (ieee80211_vif_is_mesh(&sta->sdata->vif)) 251 ieee80211s_update_metric(local, sta, skb); 252 253 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked) 254 ieee80211_frame_acked(sta, skb); 255 256 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) && 257 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)) 258 ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked); 259 260 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) { 261 if (info->flags & IEEE80211_TX_STAT_ACK) { 262 if (sta->lost_packets) 263 sta->lost_packets = 0; 264 } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) { 265 cfg80211_cqm_pktloss_notify(sta->sdata->dev, 266 sta->sta.addr, 267 sta->lost_packets, 268 GFP_ATOMIC); 269 sta->lost_packets = 0; 270 } 271 } 272 } 273 274 rcu_read_unlock(); 275 276 ieee80211_led_tx(local, 0); 277 278 /* SNMP counters 279 * Fragments are passed to low-level drivers as separate skbs, so these 280 * are actually fragments, not frames. Update frame counters only for 281 * the first fragment of the frame. */ 282 283 frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG; 284 type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE; 285 286 if (info->flags & IEEE80211_TX_STAT_ACK) { 287 if (frag == 0) { 288 local->dot11TransmittedFrameCount++; 289 if (is_multicast_ether_addr(hdr->addr1)) 290 local->dot11MulticastTransmittedFrameCount++; 291 if (retry_count > 0) 292 local->dot11RetryCount++; 293 if (retry_count > 1) 294 local->dot11MultipleRetryCount++; 295 } 296 297 /* This counter shall be incremented for an acknowledged MPDU 298 * with an individual address in the address 1 field or an MPDU 299 * with a multicast address in the address 1 field of type Data 300 * or Management. */ 301 if (!is_multicast_ether_addr(hdr->addr1) || 302 type == IEEE80211_FTYPE_DATA || 303 type == IEEE80211_FTYPE_MGMT) 304 local->dot11TransmittedFragmentCount++; 305 } else { 306 if (frag == 0) 307 local->dot11FailedCount++; 308 } 309 310 if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) && 311 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) && 312 !(info->flags & IEEE80211_TX_CTL_INJECTED) && 313 local->ps_sdata && !(local->scanning)) { 314 if (info->flags & IEEE80211_TX_STAT_ACK) { 315 local->ps_sdata->u.mgd.flags |= 316 IEEE80211_STA_NULLFUNC_ACKED; 317 ieee80211_queue_work(&local->hw, 318 &local->dynamic_ps_enable_work); 319 } else 320 mod_timer(&local->dynamic_ps_timer, jiffies + 321 msecs_to_jiffies(10)); 322 } 323 324 if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) { 325 struct ieee80211_work *wk; 326 327 rcu_read_lock(); 328 list_for_each_entry_rcu(wk, &local->work_list, list) { 329 if (wk->type != IEEE80211_WORK_OFFCHANNEL_TX) 330 continue; 331 if (wk->offchan_tx.frame != skb) 332 continue; 333 wk->offchan_tx.frame = NULL; 334 break; 335 } 336 rcu_read_unlock(); 337 cfg80211_mgmt_tx_status( 338 skb->dev, (unsigned long) skb, skb->data, skb->len, 339 !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC); 340 } 341 342 /* this was a transmitted frame, but now we want to reuse it */ 343 skb_orphan(skb); 344 345 /* Need to make a copy before skb->cb gets cleared */ 346 send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) || 347 (type != IEEE80211_FTYPE_DATA); 348 349 /* 350 * This is a bit racy but we can avoid a lot of work 351 * with this test... 352 */ 353 if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) { 354 dev_kfree_skb(skb); 355 return; 356 } 357 358 /* send frame to monitor interfaces now */ 359 360 if (skb_headroom(skb) < sizeof(*rthdr)) { 361 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n"); 362 dev_kfree_skb(skb); 363 return; 364 } 365 366 rthdr = (struct ieee80211_tx_status_rtap_hdr *) 367 skb_push(skb, sizeof(*rthdr)); 368 369 memset(rthdr, 0, sizeof(*rthdr)); 370 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr)); 371 rthdr->hdr.it_present = 372 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) | 373 (1 << IEEE80211_RADIOTAP_DATA_RETRIES) | 374 (1 << IEEE80211_RADIOTAP_RATE)); 375 376 if (!(info->flags & IEEE80211_TX_STAT_ACK) && 377 !is_multicast_ether_addr(hdr->addr1)) 378 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL); 379 380 /* 381 * XXX: Once radiotap gets the bitmap reset thing the vendor 382 * extensions proposal contains, we can actually report 383 * the whole set of tries we did. 384 */ 385 if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) || 386 (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)) 387 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS); 388 else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) 389 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS); 390 if (info->status.rates[0].idx >= 0 && 391 !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) 392 rthdr->rate = sband->bitrates[ 393 info->status.rates[0].idx].bitrate / 5; 394 395 /* for now report the total retry_count */ 396 rthdr->data_retries = retry_count; 397 398 /* XXX: is this sufficient for BPF? */ 399 skb_set_mac_header(skb, 0); 400 skb->ip_summed = CHECKSUM_UNNECESSARY; 401 skb->pkt_type = PACKET_OTHERHOST; 402 skb->protocol = htons(ETH_P_802_2); 403 memset(skb->cb, 0, sizeof(skb->cb)); 404 405 rcu_read_lock(); 406 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 407 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) { 408 if (!ieee80211_sdata_running(sdata)) 409 continue; 410 411 if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) && 412 !send_to_cooked) 413 continue; 414 415 if (prev_dev) { 416 skb2 = skb_clone(skb, GFP_ATOMIC); 417 if (skb2) { 418 skb2->dev = prev_dev; 419 netif_rx(skb2); 420 } 421 } 422 423 prev_dev = sdata->dev; 424 } 425 } 426 if (prev_dev) { 427 skb->dev = prev_dev; 428 netif_rx(skb); 429 skb = NULL; 430 } 431 rcu_read_unlock(); 432 dev_kfree_skb(skb); 433 } 434 EXPORT_SYMBOL(ieee80211_tx_status); 435