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 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 62 sta->tx_filtered_count++; 63 64 /* 65 * Clear the TX filter mask for this STA when sending the next 66 * packet. If the STA went to power save mode, this will happen 67 * when it wakes up for the next time. 68 */ 69 set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT); 70 71 /* 72 * This code races in the following way: 73 * 74 * (1) STA sends frame indicating it will go to sleep and does so 75 * (2) hardware/firmware adds STA to filter list, passes frame up 76 * (3) hardware/firmware processes TX fifo and suppresses a frame 77 * (4) we get TX status before having processed the frame and 78 * knowing that the STA has gone to sleep. 79 * 80 * This is actually quite unlikely even when both those events are 81 * processed from interrupts coming in quickly after one another or 82 * even at the same time because we queue both TX status events and 83 * RX frames to be processed by a tasklet and process them in the 84 * same order that they were received or TX status last. Hence, there 85 * is no race as long as the frame RX is processed before the next TX 86 * status, which drivers can ensure, see below. 87 * 88 * Note that this can only happen if the hardware or firmware can 89 * actually add STAs to the filter list, if this is done by the 90 * driver in response to set_tim() (which will only reduce the race 91 * this whole filtering tries to solve, not completely solve it) 92 * this situation cannot happen. 93 * 94 * To completely solve this race drivers need to make sure that they 95 * (a) don't mix the irq-safe/not irq-safe TX status/RX processing 96 * functions and 97 * (b) always process RX events before TX status events if ordering 98 * can be unknown, for example with different interrupt status 99 * bits. 100 */ 101 if (test_sta_flags(sta, WLAN_STA_PS_STA) && 102 skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) { 103 skb_queue_tail(&sta->tx_filtered, skb); 104 return; 105 } 106 107 if (!test_sta_flags(sta, WLAN_STA_PS_STA) && 108 !(info->flags & IEEE80211_TX_INTFL_RETRIED)) { 109 /* Software retry the packet once */ 110 info->flags |= IEEE80211_TX_INTFL_RETRIED; 111 ieee80211_add_pending_skb(local, skb); 112 return; 113 } 114 115 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 116 if (net_ratelimit()) 117 printk(KERN_DEBUG "%s: dropped TX filtered frame, " 118 "queue_len=%d PS=%d @%lu\n", 119 wiphy_name(local->hw.wiphy), 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 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) 161 { 162 struct sk_buff *skb2; 163 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 164 struct ieee80211_local *local = hw_to_local(hw); 165 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 166 u16 frag, type; 167 __le16 fc; 168 struct ieee80211_supported_band *sband; 169 struct ieee80211_tx_status_rtap_hdr *rthdr; 170 struct ieee80211_sub_if_data *sdata; 171 struct net_device *prev_dev = NULL; 172 struct sta_info *sta, *tmp; 173 int retry_count = -1, i; 174 bool injected; 175 176 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 177 /* the HW cannot have attempted that rate */ 178 if (i >= hw->max_rates) { 179 info->status.rates[i].idx = -1; 180 info->status.rates[i].count = 0; 181 } 182 183 retry_count += info->status.rates[i].count; 184 } 185 if (retry_count < 0) 186 retry_count = 0; 187 188 rcu_read_lock(); 189 190 sband = local->hw.wiphy->bands[info->band]; 191 fc = hdr->frame_control; 192 193 for_each_sta_info(local, hdr->addr1, sta, tmp) { 194 /* skip wrong virtual interface */ 195 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN)) 196 continue; 197 198 if (!(info->flags & IEEE80211_TX_STAT_ACK) && 199 test_sta_flags(sta, WLAN_STA_PS_STA)) { 200 /* 201 * The STA is in power save mode, so assume 202 * that this TX packet failed because of that. 203 */ 204 ieee80211_handle_filtered_frame(local, sta, skb); 205 rcu_read_unlock(); 206 return; 207 } 208 209 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) && 210 (ieee80211_is_data_qos(fc))) { 211 u16 tid, ssn; 212 u8 *qc; 213 214 qc = ieee80211_get_qos_ctl(hdr); 215 tid = qc[0] & 0xf; 216 ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10) 217 & IEEE80211_SCTL_SEQ); 218 ieee80211_send_bar(sta->sdata, hdr->addr1, 219 tid, ssn); 220 } 221 222 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) { 223 ieee80211_handle_filtered_frame(local, sta, skb); 224 rcu_read_unlock(); 225 return; 226 } else { 227 if (!(info->flags & IEEE80211_TX_STAT_ACK)) 228 sta->tx_retry_failed++; 229 sta->tx_retry_count += retry_count; 230 } 231 232 rate_control_tx_status(local, sband, sta, skb); 233 if (ieee80211_vif_is_mesh(&sta->sdata->vif)) 234 ieee80211s_update_metric(local, sta, skb); 235 236 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && 237 (info->flags & IEEE80211_TX_STAT_ACK)) 238 ieee80211_frame_acked(sta, skb); 239 } 240 241 rcu_read_unlock(); 242 243 ieee80211_led_tx(local, 0); 244 245 /* SNMP counters 246 * Fragments are passed to low-level drivers as separate skbs, so these 247 * are actually fragments, not frames. Update frame counters only for 248 * the first fragment of the frame. */ 249 250 frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG; 251 type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE; 252 253 if (info->flags & IEEE80211_TX_STAT_ACK) { 254 if (frag == 0) { 255 local->dot11TransmittedFrameCount++; 256 if (is_multicast_ether_addr(hdr->addr1)) 257 local->dot11MulticastTransmittedFrameCount++; 258 if (retry_count > 0) 259 local->dot11RetryCount++; 260 if (retry_count > 1) 261 local->dot11MultipleRetryCount++; 262 } 263 264 /* This counter shall be incremented for an acknowledged MPDU 265 * with an individual address in the address 1 field or an MPDU 266 * with a multicast address in the address 1 field of type Data 267 * or Management. */ 268 if (!is_multicast_ether_addr(hdr->addr1) || 269 type == IEEE80211_FTYPE_DATA || 270 type == IEEE80211_FTYPE_MGMT) 271 local->dot11TransmittedFragmentCount++; 272 } else { 273 if (frag == 0) 274 local->dot11FailedCount++; 275 } 276 277 if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) && 278 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) && 279 !(info->flags & IEEE80211_TX_CTL_INJECTED) && 280 local->ps_sdata && !(local->scanning)) { 281 if (info->flags & IEEE80211_TX_STAT_ACK) { 282 local->ps_sdata->u.mgd.flags |= 283 IEEE80211_STA_NULLFUNC_ACKED; 284 ieee80211_queue_work(&local->hw, 285 &local->dynamic_ps_enable_work); 286 } else 287 mod_timer(&local->dynamic_ps_timer, jiffies + 288 msecs_to_jiffies(10)); 289 } 290 291 if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) 292 cfg80211_action_tx_status( 293 skb->dev, (unsigned long) skb, skb->data, skb->len, 294 !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC); 295 296 /* this was a transmitted frame, but now we want to reuse it */ 297 skb_orphan(skb); 298 299 /* 300 * This is a bit racy but we can avoid a lot of work 301 * with this test... 302 */ 303 if (!local->monitors && !local->cooked_mntrs) { 304 dev_kfree_skb(skb); 305 return; 306 } 307 308 /* send frame to monitor interfaces now */ 309 310 if (skb_headroom(skb) < sizeof(*rthdr)) { 311 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n"); 312 dev_kfree_skb(skb); 313 return; 314 } 315 316 rthdr = (struct ieee80211_tx_status_rtap_hdr *) 317 skb_push(skb, sizeof(*rthdr)); 318 319 memset(rthdr, 0, sizeof(*rthdr)); 320 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr)); 321 rthdr->hdr.it_present = 322 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) | 323 (1 << IEEE80211_RADIOTAP_DATA_RETRIES) | 324 (1 << IEEE80211_RADIOTAP_RATE)); 325 326 if (!(info->flags & IEEE80211_TX_STAT_ACK) && 327 !is_multicast_ether_addr(hdr->addr1)) 328 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL); 329 330 /* 331 * XXX: Once radiotap gets the bitmap reset thing the vendor 332 * extensions proposal contains, we can actually report 333 * the whole set of tries we did. 334 */ 335 if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) || 336 (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)) 337 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS); 338 else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) 339 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS); 340 if (info->status.rates[0].idx >= 0 && 341 !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) 342 rthdr->rate = sband->bitrates[ 343 info->status.rates[0].idx].bitrate / 5; 344 345 /* for now report the total retry_count */ 346 rthdr->data_retries = retry_count; 347 348 /* Need to make a copy before skb->cb gets cleared */ 349 injected = !!(info->flags & IEEE80211_TX_CTL_INJECTED); 350 351 /* XXX: is this sufficient for BPF? */ 352 skb_set_mac_header(skb, 0); 353 skb->ip_summed = CHECKSUM_UNNECESSARY; 354 skb->pkt_type = PACKET_OTHERHOST; 355 skb->protocol = htons(ETH_P_802_2); 356 memset(skb->cb, 0, sizeof(skb->cb)); 357 358 rcu_read_lock(); 359 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 360 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) { 361 if (!ieee80211_sdata_running(sdata)) 362 continue; 363 364 if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) && 365 !injected && 366 (type == IEEE80211_FTYPE_DATA)) 367 continue; 368 369 if (prev_dev) { 370 skb2 = skb_clone(skb, GFP_ATOMIC); 371 if (skb2) { 372 skb2->dev = prev_dev; 373 netif_rx(skb2); 374 } 375 } 376 377 prev_dev = sdata->dev; 378 } 379 } 380 if (prev_dev) { 381 skb->dev = prev_dev; 382 netif_rx(skb); 383 skb = NULL; 384 } 385 rcu_read_unlock(); 386 dev_kfree_skb(skb); 387 } 388 EXPORT_SYMBOL(ieee80211_tx_status); 389