net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  * Copyright 2013-2014  Intel Mobile Communications GmbH
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/module.h>
  13 #include <linux/if_arp.h>
  14 #include <linux/types.h>
  15 #include <net/ip.h>
  16 #include <net/pkt_sched.h>
  17
  18 #include <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "wme.h"
  21
  22 /* Default mapping in classifier to work with default
  23  * queue setup.
  24  */
  25 const int ieee802_1d_to_ac[8] = {
  26         IEEE80211_AC_BE,
  27         IEEE80211_AC_BK,
  28         IEEE80211_AC_BK,
  29         IEEE80211_AC_BE,
  30         IEEE80211_AC_VI,
  31         IEEE80211_AC_VI,
  32         IEEE80211_AC_VO,
  33         IEEE80211_AC_VO
  34 };
  35
  36 static int wme_downgrade_ac(struct sk_buff *skb)
  37 {
  38         switch (skb->priority) {
  39         case 6:
  40         case 7:
  41                 skb->priority = 5; /* VO -> VI */
  42                 return 0;
  43         case 4:
  44         case 5:
  45                 skb->priority = 3; /* VI -> BE */
  46                 return 0;
  47         case 0:
  48         case 3:
  49                 skb->priority = 2; /* BE -> BK */
  50                 return 0;
  51         default:
  52                 return -1;
  53         }
  54 }
  55
  56 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
  57                                      struct sta_info *sta, struct sk_buff *skb)
  58 {
  59         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  60
  61         /* in case we are a client verify acm is not set for this ac */
  62         while (sdata->wmm_acm & BIT(skb->priority)) {
  63                 int ac = ieee802_1d_to_ac[skb->priority];
  64
  65                 if (ifmgd->tx_tspec[ac].admitted_time &&
  66                     skb->priority == ifmgd->tx_tspec[ac].up)
  67                         return ac;
  68
  69                 if (wme_downgrade_ac(skb)) {
  70                         /*
  71                          * This should not really happen. The AP has marked all
  72                          * lower ACs to require admission control which is not
  73                          * a reasonable configuration. Allow the frame to be
  74                          * transmitted using AC_BK as a workaround.
  75                          */
  76                         break;
  77                 }
  78         }
  79
  80         /* look up which queue to use for frames with this 1d tag */
  81         return ieee802_1d_to_ac[skb->priority];
  82 }
  83
  84 /* Indicate which queue to use for this fully formed 802.11 frame */
  85 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
  86                                  struct sk_buff *skb,
  87                                  struct ieee80211_hdr *hdr)
  88 {
  89         struct ieee80211_local *local = sdata->local;
  90         u8 *p;
  91
  92         if (local->hw.queues < IEEE80211_NUM_ACS)
  93                 return 0;
  94
  95         if (!ieee80211_is_data(hdr->frame_control)) {
  96                 skb->priority = 7;
  97                 return ieee802_1d_to_ac[skb->priority];
  98         }
  99         if (!ieee80211_is_data_qos(hdr->frame_control)) {
 100                 skb->priority = 0;
 101                 return ieee802_1d_to_ac[skb->priority];
 102         }
 103
 104         p = ieee80211_get_qos_ctl(hdr);
 105         skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
 106
 107         return ieee80211_downgrade_queue(sdata, NULL, skb);
 108 }
 109
 110 /* Indicate which queue to use. */
 111 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 112                            struct sk_buff *skb)
 113 {
 114         struct ieee80211_local *local = sdata->local;
 115         struct sta_info *sta = NULL;
 116         const u8 *ra = NULL;
 117         bool qos = false;
 118         struct mac80211_qos_map *qos_map;
 119         u16 ret;
 120
 121         if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
 122                 skb->priority = 0; /* required for correct WPA/11i MIC */
 123                 return 0;
 124         }
 125
 126         rcu_read_lock();
 127         switch (sdata->vif.type) {
 128         case NL80211_IFTYPE_AP_VLAN:
 129                 sta = rcu_dereference(sdata->u.vlan.sta);
 130                 if (sta) {
 131                         qos = sta->sta.wme;
 132                         break;
 133                 }
 134         case NL80211_IFTYPE_AP:
 135                 ra = skb->data;
 136                 break;
 137         case NL80211_IFTYPE_WDS:
 138                 ra = sdata->u.wds.remote_addr;
 139                 break;
 140 #ifdef CONFIG_MAC80211_MESH
 141         case NL80211_IFTYPE_MESH_POINT:
 142                 qos = true;
 143                 break;
 144 #endif
 145         case NL80211_IFTYPE_STATION:
 146                 ra = sdata->u.mgd.bssid;
 147                 break;
 148         case NL80211_IFTYPE_ADHOC:
 149                 ra = skb->data;
 150                 break;
 151         case NL80211_IFTYPE_OCB:
 152                 /* all stations are required to support WME */
 153                 qos = true;
 154                 break;
 155         default:
 156                 break;
 157         }
 158
 159         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 160                 sta = sta_info_get(sdata, ra);
 161                 if (sta)
 162                         qos = sta->sta.wme;
 163         }
 164
 165         if (!qos) {
 166                 skb->priority = 0; /* required for correct WPA/11i MIC */
 167                 ret = IEEE80211_AC_BE;
 168                 goto out;
 169         }
 170
 171         if (skb->protocol == sdata->control_port_protocol) {
 172                 skb->priority = 7;
 173                 goto downgrade;
 174         }
 175
 176         /* use the data classifier to determine what 802.1d tag the
 177          * data frame has */
 178         qos_map = rcu_dereference(sdata->qos_map);
 179         skb->priority = cfg80211_classify8021d(skb, qos_map ?
 180                                                &qos_map->qos_map : NULL);
 181
 182  downgrade:
 183         ret = ieee80211_downgrade_queue(sdata, sta, skb);
 184  out:
 185         rcu_read_unlock();
 186         return ret;
 187 }
 188
 189 /**
 190  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
 191  *
 192  * @sdata: local subif
 193  * @skb: packet to be updated
 194  */
 195 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 196                            struct sk_buff *skb)
 197 {
 198         struct ieee80211_hdr *hdr = (void *)skb->data;
 199         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 200         u8 *p;
 201         u8 ack_policy, tid;
 202
 203         if (!ieee80211_is_data_qos(hdr->frame_control))
 204                 return;
 205
 206         p = ieee80211_get_qos_ctl(hdr);
 207         tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 208
 209         /* preserve EOSP bit */
 210         ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
 211
 212         if (is_multicast_ether_addr(hdr->addr1) ||
 213             sdata->noack_map & BIT(tid)) {
 214                 ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 215                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 216         }
 217
 218         /* qos header is 2 bytes */
 219         *p++ = ack_policy | tid;
 220         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 221                 /* preserve RSPI and Mesh PS Level bit */
 222                 *p &= ((IEEE80211_QOS_CTL_RSPI |
 223                         IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
 224
 225                 /* Nulls don't have a mesh header (frame body) */
 226                 if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
 227                         *p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
 228         } else {
 229                 *p = 0;
 230         }
 231 }