net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/skbuff.h>
  11 #include <linux/module.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/types.h>
  14 #include <net/ip.h>
  15 #include <net/pkt_sched.h>
  16
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "wme.h"
  20
  21 /* Default mapping in classifier to work with default
  22  * queue setup.
  23  */
  24 const int ieee802_1d_to_ac[8] = {
  25         IEEE80211_AC_BE,
  26         IEEE80211_AC_BK,
  27         IEEE80211_AC_BK,
  28         IEEE80211_AC_BE,
  29         IEEE80211_AC_VI,
  30         IEEE80211_AC_VI,
  31         IEEE80211_AC_VO,
  32         IEEE80211_AC_VO
  33 };
  34
  35 static int wme_downgrade_ac(struct sk_buff *skb)
  36 {
  37         switch (skb->priority) {
  38         case 6:
  39         case 7:
  40                 skb->priority = 5; /* VO -> VI */
  41                 return 0;
  42         case 4:
  43         case 5:
  44                 skb->priority = 3; /* VI -> BE */
  45                 return 0;
  46         case 0:
  47         case 3:
  48                 skb->priority = 2; /* BE -> BK */
  49                 return 0;
  50         default:
  51                 return -1;
  52         }
  53 }
  54
  55 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
  56                                      struct sk_buff *skb)
  57 {
  58         /* in case we are a client verify acm is not set for this ac */
  59         while (unlikely(sdata->wmm_acm & BIT(skb->priority))) {
  60                 if (wme_downgrade_ac(skb)) {
  61                         /*
  62                          * This should not really happen. The AP has marked all
  63                          * lower ACs to require admission control which is not
  64                          * a reasonable configuration. Allow the frame to be
  65                          * transmitted using AC_BK as a workaround.
  66                          */
  67                         break;
  68                 }
  69         }
  70
  71         /* look up which queue to use for frames with this 1d tag */
  72         return ieee802_1d_to_ac[skb->priority];
  73 }
  74
  75 /* Indicate which queue to use for this fully formed 802.11 frame */
  76 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
  77                                  struct sk_buff *skb,
  78                                  struct ieee80211_hdr *hdr)
  79 {
  80         struct ieee80211_local *local = sdata->local;
  81         u8 *p;
  82
  83         if (local->hw.queues < IEEE80211_NUM_ACS)
  84                 return 0;
  85
  86         if (!ieee80211_is_data(hdr->frame_control)) {
  87                 skb->priority = 7;
  88                 return ieee802_1d_to_ac[skb->priority];
  89         }
  90         if (!ieee80211_is_data_qos(hdr->frame_control)) {
  91                 skb->priority = 0;
  92                 return ieee802_1d_to_ac[skb->priority];
  93         }
  94
  95         p = ieee80211_get_qos_ctl(hdr);
  96         skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
  97
  98         return ieee80211_downgrade_queue(sdata, skb);
  99 }
 100
 101 /* Indicate which queue to use. */
 102 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 103                            struct sk_buff *skb)
 104 {
 105         struct ieee80211_local *local = sdata->local;
 106         struct sta_info *sta = NULL;
 107         const u8 *ra = NULL;
 108         bool qos = false;
 109         struct mac80211_qos_map *qos_map;
 110
 111         if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
 112                 skb->priority = 0; /* required for correct WPA/11i MIC */
 113                 return 0;
 114         }
 115
 116         rcu_read_lock();
 117         switch (sdata->vif.type) {
 118         case NL80211_IFTYPE_AP_VLAN:
 119                 sta = rcu_dereference(sdata->u.vlan.sta);
 120                 if (sta) {
 121                         qos = test_sta_flag(sta, WLAN_STA_WME);
 122                         break;
 123                 }
 124         case NL80211_IFTYPE_AP:
 125                 ra = skb->data;
 126                 break;
 127         case NL80211_IFTYPE_WDS:
 128                 ra = sdata->u.wds.remote_addr;
 129                 break;
 130 #ifdef CONFIG_MAC80211_MESH
 131         case NL80211_IFTYPE_MESH_POINT:
 132                 qos = true;
 133                 break;
 134 #endif
 135         case NL80211_IFTYPE_STATION:
 136                 ra = sdata->u.mgd.bssid;
 137                 break;
 138         case NL80211_IFTYPE_ADHOC:
 139                 ra = skb->data;
 140                 break;
 141         default:
 142                 break;
 143         }
 144
 145         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 146                 sta = sta_info_get(sdata, ra);
 147                 if (sta)
 148                         qos = test_sta_flag(sta, WLAN_STA_WME);
 149         }
 150         rcu_read_unlock();
 151
 152         if (!qos) {
 153                 skb->priority = 0; /* required for correct WPA/11i MIC */
 154                 return IEEE80211_AC_BE;
 155         }
 156
 157         /* use the data classifier to determine what 802.1d tag the
 158          * data frame has */
 159         rcu_read_lock();
 160         qos_map = rcu_dereference(sdata->qos_map);
 161         skb->priority = cfg80211_classify8021d(skb, qos_map ?
 162                                                &qos_map->qos_map : NULL);
 163         rcu_read_unlock();
 164
 165         return ieee80211_downgrade_queue(sdata, skb);
 166 }
 167
 168 /**
 169  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
 170  *
 171  * @sdata: local subif
 172  * @skb: packet to be updated
 173  */
 174 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 175                            struct sk_buff *skb)
 176 {
 177         struct ieee80211_hdr *hdr = (void *)skb->data;
 178         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 179         u8 *p;
 180         u8 ack_policy, tid;
 181
 182         if (!ieee80211_is_data_qos(hdr->frame_control))
 183                 return;
 184
 185         p = ieee80211_get_qos_ctl(hdr);
 186         tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 187
 188         /* preserve EOSP bit */
 189         ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
 190
 191         if (is_multicast_ether_addr(hdr->addr1) ||
 192             sdata->noack_map & BIT(tid)) {
 193                 ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 194                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 195         }
 196
 197         /* qos header is 2 bytes */
 198         *p++ = ack_policy | tid;
 199         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 200                 /* preserve RSPI and Mesh PS Level bit */
 201                 *p &= ((IEEE80211_QOS_CTL_RSPI |
 202                         IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
 203
 204                 /* Nulls don't have a mesh header (frame body) */
 205                 if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
 206                         *p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
 207         } else {
 208                 *p = 0;
 209         }
 210 }