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 * (c) if PS mode transitions are manual (i.e. the flag 102 * %IEEE80211_HW_AP_LINK_PS is set), always process PS state 103 * changes before calling TX status events if ordering can be 104 * unknown. 105 */ 106 if (test_sta_flags(sta, WLAN_STA_PS_STA) && 107 skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) { 108 skb_queue_tail(&sta->tx_filtered, skb); 109 return; 110 } 111 112 if (!test_sta_flags(sta, WLAN_STA_PS_STA) && 113 !(info->flags & IEEE80211_TX_INTFL_RETRIED)) { 114 /* Software retry the packet once */ 115 info->flags |= IEEE80211_TX_INTFL_RETRIED; 116 ieee80211_add_pending_skb(local, skb); 117 return; 118 } 119 120 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 121 if (net_ratelimit()) 122 wiphy_debug(local->hw.wiphy, 123 "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n", 124 skb_queue_len(&sta->tx_filtered), 125 !!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies); 126 #endif 127 dev_kfree_skb(skb); 128 } 129 130 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb) 131 { 132 struct ieee80211_mgmt *mgmt = (void *) skb->data; 133 struct ieee80211_local *local = sta->local; 134 struct ieee80211_sub_if_data *sdata = sta->sdata; 135 136 if (ieee80211_is_action(mgmt->frame_control) && 137 sdata->vif.type == NL80211_IFTYPE_STATION && 138 mgmt->u.action.category == WLAN_CATEGORY_HT && 139 mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) { 140 /* 141 * This update looks racy, but isn't -- if we come 142 * here we've definitely got a station that we're 143 * talking to, and on a managed interface that can 144 * only be the AP. And the only other place updating 145 * this variable is before we're associated. 146 */ 147 switch (mgmt->u.action.u.ht_smps.smps_control) { 148 case WLAN_HT_SMPS_CONTROL_DYNAMIC: 149 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC; 150 break; 151 case WLAN_HT_SMPS_CONTROL_STATIC: 152 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC; 153 break; 154 case WLAN_HT_SMPS_CONTROL_DISABLED: 155 default: /* shouldn't happen since we don't send that */ 156 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF; 157 break; 158 } 159 160 ieee80211_queue_work(&local->hw, &local->recalc_smps); 161 } 162 } 163 164 /* 165 * Use a static threshold for now, best value to be determined 166 * by testing ... 167 * Should it depend on: 168 * - on # of retransmissions 169 * - current throughput (higher value for higher tpt)? 170 */ 171 #define STA_LOST_PKT_THRESHOLD 50 172 173 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) 174 { 175 struct sk_buff *skb2; 176 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 177 struct ieee80211_local *local = hw_to_local(hw); 178 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 179 u16 frag, type; 180 __le16 fc; 181 struct ieee80211_supported_band *sband; 182 struct ieee80211_tx_status_rtap_hdr *rthdr; 183 struct ieee80211_sub_if_data *sdata; 184 struct net_device *prev_dev = NULL; 185 struct sta_info *sta, *tmp; 186 int retry_count = -1, i; 187 int rates_idx = -1; 188 bool send_to_cooked; 189 bool acked; 190 191 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 192 /* the HW cannot have attempted that rate */ 193 if (i >= hw->max_report_rates) { 194 info->status.rates[i].idx = -1; 195 info->status.rates[i].count = 0; 196 } else if (info->status.rates[i].idx >= 0) { 197 rates_idx = i; 198 } 199 200 retry_count += info->status.rates[i].count; 201 } 202 if (retry_count < 0) 203 retry_count = 0; 204 205 rcu_read_lock(); 206 207 sband = local->hw.wiphy->bands[info->band]; 208 fc = hdr->frame_control; 209 210 for_each_sta_info(local, hdr->addr1, sta, tmp) { 211 /* skip wrong virtual interface */ 212 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN)) 213 continue; 214 215 acked = !!(info->flags & IEEE80211_TX_STAT_ACK); 216 if (!acked && test_sta_flags(sta, WLAN_STA_PS_STA)) { 217 /* 218 * The STA is in power save mode, so assume 219 * that this TX packet failed because of that. 220 */ 221 ieee80211_handle_filtered_frame(local, sta, skb); 222 rcu_read_unlock(); 223 return; 224 } 225 226 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) && 227 (rates_idx != -1)) 228 sta->last_tx_rate = info->status.rates[rates_idx]; 229 230 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) && 231 (ieee80211_is_data_qos(fc))) { 232 u16 tid, ssn; 233 u8 *qc; 234 235 qc = ieee80211_get_qos_ctl(hdr); 236 tid = qc[0] & 0xf; 237 ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10) 238 & IEEE80211_SCTL_SEQ); 239 ieee80211_send_bar(sta->sdata, hdr->addr1, 240 tid, ssn); 241 } 242 243 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) { 244 ieee80211_handle_filtered_frame(local, sta, skb); 245 rcu_read_unlock(); 246 return; 247 } else { 248 if (!acked) 249 sta->tx_retry_failed++; 250 sta->tx_retry_count += retry_count; 251 } 252 253 rate_control_tx_status(local, sband, sta, skb); 254 if (ieee80211_vif_is_mesh(&sta->sdata->vif)) 255 ieee80211s_update_metric(local, sta, skb); 256 257 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked) 258 ieee80211_frame_acked(sta, skb); 259 260 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) && 261 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)) 262 ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked); 263 264 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) { 265 if (info->flags & IEEE80211_TX_STAT_ACK) { 266 if (sta->lost_packets) 267 sta->lost_packets = 0; 268 } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) { 269 cfg80211_cqm_pktloss_notify(sta->sdata->dev, 270 sta->sta.addr, 271 sta->lost_packets, 272 GFP_ATOMIC); 273 sta->lost_packets = 0; 274 } 275 } 276 } 277 278 rcu_read_unlock(); 279 280 ieee80211_led_tx(local, 0); 281 282 /* SNMP counters 283 * Fragments are passed to low-level drivers as separate skbs, so these 284 * are actually fragments, not frames. Update frame counters only for 285 * the first fragment of the frame. */ 286 287 frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG; 288 type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE; 289 290 if (info->flags & IEEE80211_TX_STAT_ACK) { 291 if (frag == 0) { 292 local->dot11TransmittedFrameCount++; 293 if (is_multicast_ether_addr(hdr->addr1)) 294 local->dot11MulticastTransmittedFrameCount++; 295 if (retry_count > 0) 296 local->dot11RetryCount++; 297 if (retry_count > 1) 298 local->dot11MultipleRetryCount++; 299 } 300 301 /* This counter shall be incremented for an acknowledged MPDU 302 * with an individual address in the address 1 field or an MPDU 303 * with a multicast address in the address 1 field of type Data 304 * or Management. */ 305 if (!is_multicast_ether_addr(hdr->addr1) || 306 type == IEEE80211_FTYPE_DATA || 307 type == IEEE80211_FTYPE_MGMT) 308 local->dot11TransmittedFragmentCount++; 309 } else { 310 if (frag == 0) 311 local->dot11FailedCount++; 312 } 313 314 if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) && 315 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) && 316 !(info->flags & IEEE80211_TX_CTL_INJECTED) && 317 local->ps_sdata && !(local->scanning)) { 318 if (info->flags & IEEE80211_TX_STAT_ACK) { 319 local->ps_sdata->u.mgd.flags |= 320 IEEE80211_STA_NULLFUNC_ACKED; 321 } else 322 mod_timer(&local->dynamic_ps_timer, jiffies + 323 msecs_to_jiffies(10)); 324 } 325 326 if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) { 327 struct ieee80211_work *wk; 328 u64 cookie = (unsigned long)skb; 329 330 rcu_read_lock(); 331 list_for_each_entry_rcu(wk, &local->work_list, list) { 332 if (wk->type != IEEE80211_WORK_OFFCHANNEL_TX) 333 continue; 334 if (wk->offchan_tx.frame != skb) 335 continue; 336 wk->offchan_tx.frame = NULL; 337 break; 338 } 339 rcu_read_unlock(); 340 if (local->hw_roc_skb_for_status == skb) { 341 cookie = local->hw_roc_cookie ^ 2; 342 local->hw_roc_skb_for_status = NULL; 343 } 344 345 if (cookie == local->hw_offchan_tx_cookie) 346 local->hw_offchan_tx_cookie = 0; 347 348 cfg80211_mgmt_tx_status( 349 skb->dev, cookie, skb->data, skb->len, 350 !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC); 351 } 352 353 /* this was a transmitted frame, but now we want to reuse it */ 354 skb_orphan(skb); 355 356 /* Need to make a copy before skb->cb gets cleared */ 357 send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) || 358 (type != IEEE80211_FTYPE_DATA); 359 360 /* 361 * This is a bit racy but we can avoid a lot of work 362 * with this test... 363 */ 364 if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) { 365 dev_kfree_skb(skb); 366 return; 367 } 368 369 /* send frame to monitor interfaces now */ 370 371 if (skb_headroom(skb) < sizeof(*rthdr)) { 372 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n"); 373 dev_kfree_skb(skb); 374 return; 375 } 376 377 rthdr = (struct ieee80211_tx_status_rtap_hdr *) 378 skb_push(skb, sizeof(*rthdr)); 379 380 memset(rthdr, 0, sizeof(*rthdr)); 381 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr)); 382 rthdr->hdr.it_present = 383 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) | 384 (1 << IEEE80211_RADIOTAP_DATA_RETRIES) | 385 (1 << IEEE80211_RADIOTAP_RATE)); 386 387 if (!(info->flags & IEEE80211_TX_STAT_ACK) && 388 !is_multicast_ether_addr(hdr->addr1)) 389 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL); 390 391 /* 392 * XXX: Once radiotap gets the bitmap reset thing the vendor 393 * extensions proposal contains, we can actually report 394 * the whole set of tries we did. 395 */ 396 if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) || 397 (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)) 398 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS); 399 else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) 400 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS); 401 if (info->status.rates[0].idx >= 0 && 402 !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) 403 rthdr->rate = sband->bitrates[ 404 info->status.rates[0].idx].bitrate / 5; 405 406 /* for now report the total retry_count */ 407 rthdr->data_retries = retry_count; 408 409 /* XXX: is this sufficient for BPF? */ 410 skb_set_mac_header(skb, 0); 411 skb->ip_summed = CHECKSUM_UNNECESSARY; 412 skb->pkt_type = PACKET_OTHERHOST; 413 skb->protocol = htons(ETH_P_802_2); 414 memset(skb->cb, 0, sizeof(skb->cb)); 415 416 rcu_read_lock(); 417 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 418 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) { 419 if (!ieee80211_sdata_running(sdata)) 420 continue; 421 422 if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) && 423 !send_to_cooked) 424 continue; 425 426 if (prev_dev) { 427 skb2 = skb_clone(skb, GFP_ATOMIC); 428 if (skb2) { 429 skb2->dev = prev_dev; 430 netif_rx(skb2); 431 } 432 } 433 434 prev_dev = sdata->dev; 435 } 436 } 437 if (prev_dev) { 438 skb->dev = prev_dev; 439 netif_rx(skb); 440 skb = NULL; 441 } 442 rcu_read_unlock(); 443 dev_kfree_skb(skb); 444 } 445 EXPORT_SYMBOL(ieee80211_tx_status); 446