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         u32 sta_flags = 0;
  63         const u8 *ra = NULL;
  64         bool qos = false;
  65
  66         if (local->hw.queues < 4 || skb->len < 6) {
  67                 skb->priority = 0; /* required for correct WPA/11i MIC */
  68                 return min_t(u16, local->hw.queues - 1,
  69                              ieee802_1d_to_ac[skb->priority]);
  70         }
  71
  72         rcu_read_lock();
  73         switch (sdata->vif.type) {
  74         case NL80211_IFTYPE_AP_VLAN:
  75                 rcu_read_lock();
  76                 sta = rcu_dereference(sdata->u.vlan.sta);
  77                 if (sta)
  78                         sta_flags = get_sta_flags(sta);
  79                 rcu_read_unlock();
  80                 if (sta)
  81                         break;
  82         case NL80211_IFTYPE_AP:
  83                 ra = skb->data;
  84                 break;
  85         case NL80211_IFTYPE_WDS:
  86                 ra = sdata->u.wds.remote_addr;
  87                 break;
  88 #ifdef CONFIG_MAC80211_MESH
  89         case NL80211_IFTYPE_MESH_POINT:
  90                 /*
  91                  * XXX: This is clearly broken ... but already was before,
  92                  * because ieee80211_fill_mesh_addresses() would clear A1
  93                  * except for multicast addresses.
  94                  */
  95                 break;
  96 #endif
  97         case NL80211_IFTYPE_STATION:
  98                 ra = sdata->u.mgd.bssid;
  99                 break;
 100         case NL80211_IFTYPE_ADHOC:
 101                 ra = skb->data;
 102                 break;
 103         default:
 104                 break;
 105         }
 106
 107         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 108                 sta = sta_info_get(sdata, ra);
 109                 if (sta)
 110                         sta_flags = get_sta_flags(sta);
 111         }
 112
 113         if (sta_flags & WLAN_STA_WME)
 114                 qos = true;
 115
 116         rcu_read_unlock();
 117
 118         if (!qos) {
 119                 skb->priority = 0; /* required for correct WPA/11i MIC */
 120                 return ieee802_1d_to_ac[skb->priority];
 121         }
 122
 123         /* use the data classifier to determine what 802.1d tag the
 124          * data frame has */
 125         skb->priority = cfg80211_classify8021d(skb);
 126
 127         return ieee80211_downgrade_queue(local, skb);
 128 }
 129
 130 u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
 131                               struct sk_buff *skb)
 132 {
 133         /* in case we are a client verify acm is not set for this ac */
 134         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 135                 if (wme_downgrade_ac(skb)) {
 136                         /*
 137                          * This should not really happen. The AP has marked all
 138                          * lower ACs to require admission control which is not
 139                          * a reasonable configuration. Allow the frame to be
 140                          * transmitted using AC_BK as a workaround.
 141                          */
 142                         break;
 143                 }
 144         }
 145
 146         /* look up which queue to use for frames with this 1d tag */
 147         return ieee802_1d_to_ac[skb->priority];
 148 }
 149
 150 void ieee80211_set_qos_hdr(struct ieee80211_local *local, struct sk_buff *skb)
 151 {
 152         struct ieee80211_hdr *hdr = (void *)skb->data;
 153
 154         /* Fill in the QoS header if there is one. */
 155         if (ieee80211_is_data_qos(hdr->frame_control)) {
 156                 u8 *p = ieee80211_get_qos_ctl(hdr);
 157                 u8 ack_policy = 0, tid;
 158
 159                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 160
 161                 if (unlikely(local->wifi_wme_noack_test))
 162                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 163                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 164                 /* qos header is 2 bytes, second reserved */
 165                 *p++ = ack_policy | tid;
 166                 *p = 0;
 167         }
 168 }