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 <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
new file mode 100644
index 0000000..9f91fd8
--- /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 <jbenc@suse.cz>
+ * Copyright 2008-2009 Johannes Berg <johannes@sipsolutions.net>
+ *
+ * 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 <net/mac80211.h>
+#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);