/*
   * 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;
  	}
  }
  
  static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
  				     struct sk_buff *skb)
  {
  	/* in case we are a client verify acm is not set for this ac */
  	while (unlikely(sdata->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];
  }
  
  /* Indicate which queue to use for this fully formed 802.11 frame */
  u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
  				 struct sk_buff *skb,
  				 struct ieee80211_hdr *hdr)
  {
  	struct ieee80211_local *local = sdata->local;
  	u8 *p;
  
  	if (local->hw.queues < IEEE80211_NUM_ACS)
  		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(sdata, 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;
  	struct mac80211_qos_map *qos_map;
  
  	if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
  		skb->priority = 0; /* required for correct WPA/11i MIC */
  		return 0;
  	}
  
  	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;
  	}
  
  	if (skb->protocol == sdata->control_port_protocol) {
  		skb->priority = 7;
  		return ieee80211_downgrade_queue(sdata, skb);
  	}
  
  	/* use the data classifier to determine what 802.1d tag the
  	 * data frame has */
  	rcu_read_lock();
  	qos_map = rcu_dereference(sdata->qos_map);
  	skb->priority = cfg80211_classify8021d(skb, qos_map ?
  					       &qos_map->qos_map : NULL);
  	rcu_read_unlock();
  
  	return ieee80211_downgrade_queue(sdata, skb);
  }
  
  /**
   * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
   *
   * @sdata: local subif
   * @skb: packet to be updated
   */
  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);
  	u8 *p;
  	u8 ack_policy, tid;
  
  	if (!ieee80211_is_data_qos(hdr->frame_control))
  		return;
  
  	p = ieee80211_get_qos_ctl(hdr);
  	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;
  	if (ieee80211_vif_is_mesh(&sdata->vif)) {
  		/* preserve RSPI and Mesh PS Level bit */
  		*p &= ((IEEE80211_QOS_CTL_RSPI |
  			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
  
  		/* Nulls don't have a mesh header (frame body) */
  		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
  			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
  	} else {
  		*p = 0;
  	}
  }