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
  56 /* Indicate which queue to use. */
  57 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
  58                            struct sk_buff *skb)
  59 {
  60         struct ieee80211_local *local = sdata->local;
  61         struct sta_info *sta = NULL;
  62         const u8 *ra = NULL;
  63         bool qos = false;
  64
  65         if (local->hw.queues < 4 || skb->len < 6) {
  66                 skb->priority = 0; /* required for correct WPA/11i MIC */
  67                 return min_t(u16, local->hw.queues - 1, IEEE80211_AC_BE);
  68         }
  69
  70         rcu_read_lock();
  71         switch (sdata->vif.type) {
  72         case NL80211_IFTYPE_AP_VLAN:
  73                 sta = rcu_dereference(sdata->u.vlan.sta);
  74                 if (sta) {
  75                         qos = get_sta_flags(sta) & WLAN_STA_WME;
  76                         break;
  77                 }
  78         case NL80211_IFTYPE_AP:
  79                 ra = skb->data;
  80                 break;
  81         case NL80211_IFTYPE_WDS:
  82                 ra = sdata->u.wds.remote_addr;
  83                 break;
  84 #ifdef CONFIG_MAC80211_MESH
  85         case NL80211_IFTYPE_MESH_POINT:
  86                 /*
  87                  * XXX: This is clearly broken ... but already was before,
  88                  * because ieee80211_fill_mesh_addresses() would clear A1
  89                  * except for multicast addresses.
  90                  */
  91                 break;
  92 #endif
  93         case NL80211_IFTYPE_STATION:
  94                 ra = sdata->u.mgd.bssid;
  95                 break;
  96         case NL80211_IFTYPE_ADHOC:
  97                 ra = skb->data;
  98                 break;
  99         default:
 100                 break;
 101         }
 102
 103         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 104                 sta = sta_info_get(sdata, ra);
 105                 if (sta)
 106                         qos = get_sta_flags(sta) & WLAN_STA_WME;
 107         }
 108         rcu_read_unlock();
 109
 110         if (!qos) {
 111                 skb->priority = 0; /* required for correct WPA/11i MIC */
 112                 return IEEE80211_AC_BE;
 113         }
 114
 115         /* use the data classifier to determine what 802.1d tag the
 116          * data frame has */
 117         skb->priority = cfg80211_classify8021d(skb);
 118
 119         return ieee80211_downgrade_queue(local, skb);
 120 }
 121
 122 u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
 123                               struct sk_buff *skb)
 124 {
 125         /* in case we are a client verify acm is not set for this ac */
 126         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 127                 if (wme_downgrade_ac(skb)) {
 128                         /*
 129                          * This should not really happen. The AP has marked all
 130                          * lower ACs to require admission control which is not
 131                          * a reasonable configuration. Allow the frame to be
 132                          * transmitted using AC_BK as a workaround.
 133                          */
 134                         break;
 135                 }
 136         }
 137
 138         /* look up which queue to use for frames with this 1d tag */
 139         return ieee802_1d_to_ac[skb->priority];
 140 }
 141
 142 void ieee80211_set_qos_hdr(struct ieee80211_local *local, struct sk_buff *skb)
 143 {
 144         struct ieee80211_hdr *hdr = (void *)skb->data;
 145
 146         /* Fill in the QoS header if there is one. */
 147         if (ieee80211_is_data_qos(hdr->frame_control)) {
 148                 u8 *p = ieee80211_get_qos_ctl(hdr);
 149                 u8 ack_policy = 0, tid;
 150
 151                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 152
 153                 if (unlikely(local->wifi_wme_noack_test))
 154                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 155                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 156                 /* qos header is 2 bytes, second reserved */
 157                 *p++ = ack_policy | tid;
 158                 *p = 0;
 159         }
 160 }