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
 110         if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
 111                 skb->priority = 0; /* required for correct WPA/11i MIC */
 112                 return 0;
 113         }
 114
 115         rcu_read_lock();
 116         switch (sdata->vif.type) {
 117         case NL80211_IFTYPE_AP_VLAN:
 118                 sta = rcu_dereference(sdata->u.vlan.sta);
 119                 if (sta) {
 120                         qos = test_sta_flag(sta, WLAN_STA_WME);
 121                         break;
 122                 }
 123         case NL80211_IFTYPE_AP:
 124                 ra = skb->data;
 125                 break;
 126         case NL80211_IFTYPE_WDS:
 127                 ra = sdata->u.wds.remote_addr;
 128                 break;
 129 #ifdef CONFIG_MAC80211_MESH
 130         case NL80211_IFTYPE_MESH_POINT:
 131                 qos = true;
 132                 break;
 133 #endif
 134         case NL80211_IFTYPE_STATION:
 135                 ra = sdata->u.mgd.bssid;
 136                 break;
 137         case NL80211_IFTYPE_ADHOC:
 138                 ra = skb->data;
 139                 break;
 140         default:
 141                 break;
 142         }
 143
 144         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 145                 sta = sta_info_get(sdata, ra);
 146                 if (sta)
 147                         qos = test_sta_flag(sta, WLAN_STA_WME);
 148         }
 149         rcu_read_unlock();
 150
 151         if (!qos) {
 152                 skb->priority = 0; /* required for correct WPA/11i MIC */
 153                 return IEEE80211_AC_BE;
 154         }
 155
 156         /* use the data classifier to determine what 802.1d tag the
 157          * data frame has */
 158         skb->priority = cfg80211_classify8021d(skb);
 159
 160         return ieee80211_downgrade_queue(sdata, skb);
 161 }
 162
 163 /**
 164  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
 165  *
 166  * @sdata: local subif
 167  * @skb: packet to be updated
 168  */
 169 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 170                            struct sk_buff *skb)
 171 {
 172         struct ieee80211_hdr *hdr = (void *)skb->data;
 173         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 174         u8 *p;
 175         u8 ack_policy, tid;
 176
 177         if (!ieee80211_is_data_qos(hdr->frame_control))
 178                 return;
 179
 180         p = ieee80211_get_qos_ctl(hdr);
 181         tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 182
 183         /* preserve EOSP bit */
 184         ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
 185
 186         if (is_multicast_ether_addr(hdr->addr1) ||
 187             sdata->noack_map & BIT(tid)) {
 188                 ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 189                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 190         }
 191
 192         /* qos header is 2 bytes */
 193         *p++ = ack_policy | tid;
 194         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 195                 /* preserve RSPI and Mesh PS Level bit */
 196                 *p &= ((IEEE80211_QOS_CTL_RSPI |
 197                         IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
 198
 199                 /* Nulls don't have a mesh header (frame body) */
 200                 if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
 201                         *p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
 202         } else {
 203                 *p = 0;
 204         }
 205 }