/*
   * Copyright 2004, Instant802 Networks, Inc.
   *
   * 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 <linux/netdevice.h>
  #include <linux/skbuff.h>
  #include <linux/module.h>
  #include <linux/if_arp.h>
  #include <linux/types.h>
  #include <net/ip.h>
  #include <net/pkt_sched.h>
  
  #include <net/mac80211.h>
  #include "ieee80211_i.h"
  #include "wme.h"

  /* Default mapping in classifier to work with default

   * queue setup.
   */

  const int ieee802_1d_to_ac[8] = {
  	IEEE80211_AC_BE,
  	IEEE80211_AC_BK,
  	IEEE80211_AC_BK,
  	IEEE80211_AC_BE,
  	IEEE80211_AC_VI,
  	IEEE80211_AC_VI,
  	IEEE80211_AC_VO,
  	IEEE80211_AC_VO
  };

  static int wme_downgrade_ac(struct sk_buff *skb)

  {
  	switch (skb->priority) {
  	case 6:
  	case 7:
  		skb->priority = 5; /* VO -> VI */
  		return 0;
  	case 4:
  	case 5:
  		skb->priority = 3; /* VI -> BE */
  		return 0;
  	case 0:
  	case 3:
  		skb->priority = 2; /* BE -> BK */
  		return 0;
  	default:
  		return -1;
  	}
  }

  /* Indicate which queue to use for this fully formed 802.11 frame */
  u16 ieee80211_select_queue_80211(struct ieee80211_local *local,
  				 struct sk_buff *skb,
  				 struct ieee80211_hdr *hdr)
  {
  	u8 *p;
  
  	if (local->hw.queues < 4)
  		return 0;
  
  	if (!ieee80211_is_data(hdr->frame_control)) {
  		skb->priority = 7;
  		return ieee802_1d_to_ac[skb->priority];
  	}
  	if (!ieee80211_is_data_qos(hdr->frame_control)) {
  		skb->priority = 0;
  		return ieee802_1d_to_ac[skb->priority];
  	}
  
  	p = ieee80211_get_qos_ctl(hdr);
  	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
  
  	return ieee80211_downgrade_queue(local, skb);
  }

  /* Indicate which queue to use. */
  u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
  			   struct sk_buff *skb)

  {

  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta = NULL;

  	const u8 *ra = NULL;
  	bool qos = false;

  	if (local->hw.queues < 4 || skb->len < 6) {
  		skb->priority = 0; /* required for correct WPA/11i MIC */

  		return min_t(u16, local->hw.queues - 1, IEEE80211_AC_BE);

  	}
  
  	rcu_read_lock();
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:

  		sta = rcu_dereference(sdata->u.vlan.sta);

  		if (sta) {

  			qos = test_sta_flag(sta, WLAN_STA_WME);

  			break;

  		}

  	case NL80211_IFTYPE_AP:
  		ra = skb->data;
  		break;
  	case NL80211_IFTYPE_WDS:
  		ra = sdata->u.wds.remote_addr;
  		break;
  #ifdef CONFIG_MAC80211_MESH
  	case NL80211_IFTYPE_MESH_POINT:

  		qos = true;

  		break;
  #endif
  	case NL80211_IFTYPE_STATION:
  		ra = sdata->u.mgd.bssid;
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		ra = skb->data;
  		break;
  	default:
  		break;

  	}

  	if (!sta && ra && !is_multicast_ether_addr(ra)) {
  		sta = sta_info_get(sdata, ra);
  		if (sta)

  			qos = test_sta_flag(sta, WLAN_STA_WME);

  	}

  	rcu_read_unlock();
  
  	if (!qos) {

  		skb->priority = 0; /* required for correct WPA/11i MIC */

  		return IEEE80211_AC_BE;

  	}
  
  	/* use the data classifier to determine what 802.1d tag the

  	 * data frame has */

  	skb->priority = cfg80211_classify8021d(skb);

  	return ieee80211_downgrade_queue(local, skb);
  }
  
  u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
  			      struct sk_buff *skb)
  {

  	/* in case we are a client verify acm is not set for this ac */

  	while (unlikely(local->wmm_acm & BIT(skb->priority))) {
  		if (wme_downgrade_ac(skb)) {

  			/*
  			 * This should not really happen. The AP has marked all
  			 * lower ACs to require admission control which is not
  			 * a reasonable configuration. Allow the frame to be
  			 * transmitted using AC_BK as a workaround.

  			 */

  			break;

  		}
  	}
  
  	/* look up which queue to use for frames with this 1d tag */
  	return ieee802_1d_to_ac[skb->priority];
  }

  void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
  			   struct sk_buff *skb)

  {

  	struct ieee80211_hdr *hdr = (void *)skb->data;

  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

  
  	/* Fill in the QoS header if there is one. */

  	if (ieee80211_is_data_qos(hdr->frame_control)) {

  		u8 *p = ieee80211_get_qos_ctl(hdr);

  		u8 ack_policy, tid;

  		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;

  		/* preserve EOSP bit */
  		ack_policy = *p & IEEE80211_QOS_CTL_EOSP;

  		if (is_multicast_ether_addr(hdr->addr1) ||
  		    sdata->noack_map & BIT(tid)) {

  			ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;

  			info->flags |= IEEE80211_TX_CTL_NO_ACK;
  		}

  		/* qos header is 2 bytes */

  		*p++ = ack_policy | tid;

  		*p = ieee80211_vif_is_mesh(&sdata->vif) ?
  			(IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) : 0;

  	}

  }