From fe7a5d5c1ad659bf0ec7dc171e122aeefa16ac25 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 18 Nov 2009 18:42:47 +0100 Subject: mac80211: move TX status handling It's enough code to have its own file, I think. Especially since I'm going to add to it. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/status.c | 337 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 337 insertions(+) create mode 100644 net/mac80211/status.c (limited to 'net/mac80211/status.c') diff --git a/net/mac80211/status.c b/net/mac80211/status.c new file mode 100644 index 000000000000..9f91fd8e6efb --- /dev/null +++ b/net/mac80211/status.c @@ -0,0 +1,337 @@ +/* + * Copyright 2002-2005, Instant802 Networks, Inc. + * Copyright 2005-2006, Devicescape Software, Inc. + * Copyright 2006-2007 Jiri Benc + * Copyright 2008-2009 Johannes Berg + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include "ieee80211_i.h" +#include "rate.h" +#include "mesh.h" +#include "led.h" + + +void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw, + struct sk_buff *skb) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + int tmp; + + skb->pkt_type = IEEE80211_TX_STATUS_MSG; + skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ? + &local->skb_queue : &local->skb_queue_unreliable, skb); + tmp = skb_queue_len(&local->skb_queue) + + skb_queue_len(&local->skb_queue_unreliable); + while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT && + (skb = skb_dequeue(&local->skb_queue_unreliable))) { + dev_kfree_skb_irq(skb); + tmp--; + I802_DEBUG_INC(local->tx_status_drop); + } + tasklet_schedule(&local->tasklet); +} +EXPORT_SYMBOL(ieee80211_tx_status_irqsafe); + +static void ieee80211_handle_filtered_frame(struct ieee80211_local *local, + struct sta_info *sta, + struct sk_buff *skb) +{ + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + /* + * XXX: This is temporary! + * + * The problem here is that when we get here, the driver will + * quite likely have pretty much overwritten info->control by + * using info->driver_data or info->rate_driver_data. Thus, + * when passing out the frame to the driver again, we would be + * passing completely bogus data since the driver would then + * expect a properly filled info->control. In mac80211 itself + * the same problem occurs, since we need info->control.vif + * internally. + * + * To fix this, we should send the frame through TX processing + * again. However, it's not that simple, since the frame will + * have been software-encrypted (if applicable) already, and + * encrypting it again doesn't do much good. So to properly do + * that, we not only have to skip the actual 'raw' encryption + * (key selection etc. still has to be done!) but also the + * sequence number assignment since that impacts the crypto + * encapsulation, of course. + * + * Hence, for now, fix the bug by just dropping the frame. + */ + goto drop; + + sta->tx_filtered_count++; + + /* + * Clear the TX filter mask for this STA when sending the next + * packet. If the STA went to power save mode, this will happen + * when it wakes up for the next time. + */ + set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT); + + /* + * This code races in the following way: + * + * (1) STA sends frame indicating it will go to sleep and does so + * (2) hardware/firmware adds STA to filter list, passes frame up + * (3) hardware/firmware processes TX fifo and suppresses a frame + * (4) we get TX status before having processed the frame and + * knowing that the STA has gone to sleep. + * + * This is actually quite unlikely even when both those events are + * processed from interrupts coming in quickly after one another or + * even at the same time because we queue both TX status events and + * RX frames to be processed by a tasklet and process them in the + * same order that they were received or TX status last. Hence, there + * is no race as long as the frame RX is processed before the next TX + * status, which drivers can ensure, see below. + * + * Note that this can only happen if the hardware or firmware can + * actually add STAs to the filter list, if this is done by the + * driver in response to set_tim() (which will only reduce the race + * this whole filtering tries to solve, not completely solve it) + * this situation cannot happen. + * + * To completely solve this race drivers need to make sure that they + * (a) don't mix the irq-safe/not irq-safe TX status/RX processing + * functions and + * (b) always process RX events before TX status events if ordering + * can be unknown, for example with different interrupt status + * bits. + */ + if (test_sta_flags(sta, WLAN_STA_PS_STA) && + skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) { + skb_queue_tail(&sta->tx_filtered, skb); + return; + } + + if (!test_sta_flags(sta, WLAN_STA_PS_STA) && + !(info->flags & IEEE80211_TX_INTFL_RETRIED)) { + /* Software retry the packet once */ + info->flags |= IEEE80211_TX_INTFL_RETRIED; + ieee80211_add_pending_skb(local, skb); + return; + } + + drop: +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + if (net_ratelimit()) + printk(KERN_DEBUG "%s: dropped TX filtered frame, " + "queue_len=%d PS=%d @%lu\n", + wiphy_name(local->hw.wiphy), + skb_queue_len(&sta->tx_filtered), + !!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies); +#endif + dev_kfree_skb(skb); +} + +void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb) +{ + struct sk_buff *skb2; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + u16 frag, type; + __le16 fc; + struct ieee80211_supported_band *sband; + struct ieee80211_tx_status_rtap_hdr *rthdr; + struct ieee80211_sub_if_data *sdata; + struct net_device *prev_dev = NULL; + struct sta_info *sta; + int retry_count = -1, i; + + for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { + /* the HW cannot have attempted that rate */ + if (i >= hw->max_rates) { + info->status.rates[i].idx = -1; + info->status.rates[i].count = 0; + } + + retry_count += info->status.rates[i].count; + } + if (retry_count < 0) + retry_count = 0; + + rcu_read_lock(); + + sband = local->hw.wiphy->bands[info->band]; + + sta = sta_info_get(local, hdr->addr1); + + if (sta) { + if (!(info->flags & IEEE80211_TX_STAT_ACK) && + test_sta_flags(sta, WLAN_STA_PS_STA)) { + /* + * The STA is in power save mode, so assume + * that this TX packet failed because of that. + */ + ieee80211_handle_filtered_frame(local, sta, skb); + rcu_read_unlock(); + return; + } + + fc = hdr->frame_control; + + if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) && + (ieee80211_is_data_qos(fc))) { + u16 tid, ssn; + u8 *qc; + + qc = ieee80211_get_qos_ctl(hdr); + tid = qc[0] & 0xf; + ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10) + & IEEE80211_SCTL_SEQ); + ieee80211_send_bar(sta->sdata, hdr->addr1, + tid, ssn); + } + + if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) { + ieee80211_handle_filtered_frame(local, sta, skb); + rcu_read_unlock(); + return; + } else { + if (!(info->flags & IEEE80211_TX_STAT_ACK)) + sta->tx_retry_failed++; + sta->tx_retry_count += retry_count; + } + + rate_control_tx_status(local, sband, sta, skb); + if (ieee80211_vif_is_mesh(&sta->sdata->vif)) + ieee80211s_update_metric(local, sta, skb); + } + + rcu_read_unlock(); + + ieee80211_led_tx(local, 0); + + /* SNMP counters + * Fragments are passed to low-level drivers as separate skbs, so these + * are actually fragments, not frames. Update frame counters only for + * the first fragment of the frame. */ + + frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG; + type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE; + + if (info->flags & IEEE80211_TX_STAT_ACK) { + if (frag == 0) { + local->dot11TransmittedFrameCount++; + if (is_multicast_ether_addr(hdr->addr1)) + local->dot11MulticastTransmittedFrameCount++; + if (retry_count > 0) + local->dot11RetryCount++; + if (retry_count > 1) + local->dot11MultipleRetryCount++; + } + + /* This counter shall be incremented for an acknowledged MPDU + * with an individual address in the address 1 field or an MPDU + * with a multicast address in the address 1 field of type Data + * or Management. */ + if (!is_multicast_ether_addr(hdr->addr1) || + type == IEEE80211_FTYPE_DATA || + type == IEEE80211_FTYPE_MGMT) + local->dot11TransmittedFragmentCount++; + } else { + if (frag == 0) + local->dot11FailedCount++; + } + + /* this was a transmitted frame, but now we want to reuse it */ + skb_orphan(skb); + + /* + * This is a bit racy but we can avoid a lot of work + * with this test... + */ + if (!local->monitors && !local->cooked_mntrs) { + dev_kfree_skb(skb); + return; + } + + /* send frame to monitor interfaces now */ + + if (skb_headroom(skb) < sizeof(*rthdr)) { + printk(KERN_ERR "ieee80211_tx_status: headroom too small\n"); + dev_kfree_skb(skb); + return; + } + + rthdr = (struct ieee80211_tx_status_rtap_hdr *) + skb_push(skb, sizeof(*rthdr)); + + memset(rthdr, 0, sizeof(*rthdr)); + rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr)); + rthdr->hdr.it_present = + cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) | + (1 << IEEE80211_RADIOTAP_DATA_RETRIES) | + (1 << IEEE80211_RADIOTAP_RATE)); + + if (!(info->flags & IEEE80211_TX_STAT_ACK) && + !is_multicast_ether_addr(hdr->addr1)) + rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL); + + /* + * XXX: Once radiotap gets the bitmap reset thing the vendor + * extensions proposal contains, we can actually report + * the whole set of tries we did. + */ + if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) || + (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)) + rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS); + else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) + rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS); + if (info->status.rates[0].idx >= 0 && + !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) + rthdr->rate = sband->bitrates[ + info->status.rates[0].idx].bitrate / 5; + + /* for now report the total retry_count */ + rthdr->data_retries = retry_count; + + /* XXX: is this sufficient for BPF? */ + skb_set_mac_header(skb, 0); + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb->pkt_type = PACKET_OTHERHOST; + skb->protocol = htons(ETH_P_802_2); + memset(skb->cb, 0, sizeof(skb->cb)); + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (sdata->vif.type == NL80211_IFTYPE_MONITOR) { + if (!netif_running(sdata->dev)) + continue; + + if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) && + !(info->flags & IEEE80211_TX_CTL_INJECTED) && + (type == IEEE80211_FTYPE_DATA)) + continue; + + if (prev_dev) { + skb2 = skb_clone(skb, GFP_ATOMIC); + if (skb2) { + skb2->dev = prev_dev; + netif_rx(skb2); + } + } + + prev_dev = sdata->dev; + } + } + if (prev_dev) { + skb->dev = prev_dev; + netif_rx(skb); + skb = NULL; + } + rcu_read_unlock(); + dev_kfree_skb(skb); +} +EXPORT_SYMBOL(ieee80211_tx_status); -- cgit v1.2.3