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 /* Indicate which queue to use for this fully formed 802.11 frame */
  56 u16 ieee80211_select_queue_80211(struct ieee80211_local *local,
  57                                  struct sk_buff *skb,
  58                                  struct ieee80211_hdr *hdr)
  59 {
  60         u8 *p;
  61
  62         if (local->hw.queues < 4)
  63                 return 0;
  64
  65         if (!ieee80211_is_data(hdr->frame_control)) {
  66                 skb->priority = 7;
  67                 return ieee802_1d_to_ac[skb->priority];
  68         }
  69         if (!ieee80211_is_data_qos(hdr->frame_control)) {
  70                 skb->priority = 0;
  71                 return ieee802_1d_to_ac[skb->priority];
  72         }
  73
  74         p = ieee80211_get_qos_ctl(hdr);
  75         skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
  76
  77         return ieee80211_downgrade_queue(local, skb);
  78 }
  79
  80 /* Indicate which queue to use. */
  81 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
  82                            struct sk_buff *skb)
  83 {
  84         struct ieee80211_local *local = sdata->local;
  85         struct sta_info *sta = NULL;
  86         const u8 *ra = NULL;
  87         bool qos = false;
  88
  89         if (local->hw.queues < 4 || skb->len < 6) {
  90                 skb->priority = 0; /* required for correct WPA/11i MIC */
  91                 return min_t(u16, local->hw.queues - 1, IEEE80211_AC_BE);
  92         }
  93
  94         rcu_read_lock();
  95         switch (sdata->vif.type) {
  96         case NL80211_IFTYPE_AP_VLAN:
  97                 sta = rcu_dereference(sdata->u.vlan.sta);
  98                 if (sta) {
  99                         qos = test_sta_flag(sta, WLAN_STA_WME);
 100                         break;
 101                 }
 102         case NL80211_IFTYPE_AP:
 103                 ra = skb->data;
 104                 break;
 105         case NL80211_IFTYPE_WDS:
 106                 ra = sdata->u.wds.remote_addr;
 107                 break;
 108 #ifdef CONFIG_MAC80211_MESH
 109         case NL80211_IFTYPE_MESH_POINT:
 110                 qos = true;
 111                 break;
 112 #endif
 113         case NL80211_IFTYPE_STATION:
 114                 ra = sdata->u.mgd.bssid;
 115                 break;
 116         case NL80211_IFTYPE_ADHOC:
 117                 ra = skb->data;
 118                 break;
 119         default:
 120                 break;
 121         }
 122
 123         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 124                 sta = sta_info_get(sdata, ra);
 125                 if (sta)
 126                         qos = test_sta_flag(sta, WLAN_STA_WME);
 127         }
 128         rcu_read_unlock();
 129
 130         if (!qos) {
 131                 skb->priority = 0; /* required for correct WPA/11i MIC */
 132                 return IEEE80211_AC_BE;
 133         }
 134
 135         /* use the data classifier to determine what 802.1d tag the
 136          * data frame has */
 137         skb->priority = cfg80211_classify8021d(skb);
 138
 139         return ieee80211_downgrade_queue(local, skb);
 140 }
 141
 142 u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
 143                               struct sk_buff *skb)
 144 {
 145         /* in case we are a client verify acm is not set for this ac */
 146         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 147                 if (wme_downgrade_ac(skb)) {
 148                         /*
 149                          * This should not really happen. The AP has marked all
 150                          * lower ACs to require admission control which is not
 151                          * a reasonable configuration. Allow the frame to be
 152                          * transmitted using AC_BK as a workaround.
 153                          */
 154                         break;
 155                 }
 156         }
 157
 158         /* look up which queue to use for frames with this 1d tag */
 159         return ieee802_1d_to_ac[skb->priority];
 160 }
 161
 162 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 163                            struct sk_buff *skb)
 164 {
 165         struct ieee80211_hdr *hdr = (void *)skb->data;
 166         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 167
 168         /* Fill in the QoS header if there is one. */
 169         if (ieee80211_is_data_qos(hdr->frame_control)) {
 170                 u8 *p = ieee80211_get_qos_ctl(hdr);
 171                 u8 ack_policy, tid;
 172
 173                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 174
 175                 /* preserve EOSP bit */
 176                 ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
 177
 178                 if (is_multicast_ether_addr(hdr->addr1) ||
 179                     sdata->noack_map & BIT(tid)) {
 180                         ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 181                         info->flags |= IEEE80211_TX_CTL_NO_ACK;
 182                 }
 183
 184                 /* qos header is 2 bytes */
 185                 *p++ = ack_policy | tid;
 186                 *p = ieee80211_vif_is_mesh(&sdata->vif) ?
 187                         (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) : 0;
 188         }
 189 }