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 /**
  57  * ieee80211_fix_reserved_tid - return the TID to use if this one is reserved
  58  * @tid: the assumed-reserved TID
  59  *
  60  * Returns: the alternative TID to use, or 0 on error
  61  */
  62 static inline u8 ieee80211_fix_reserved_tid(u8 tid)
  63 {
  64         switch (tid) {
  65         case 0:
  66                 return 3;
  67         case 1:
  68                 return 2;
  69         case 2:
  70                 return 1;
  71         case 3:
  72                 return 0;
  73         case 4:
  74                 return 5;
  75         case 5:
  76                 return 4;
  77         case 6:
  78                 return 7;
  79         case 7:
  80                 return 6;
  81         }
  82
  83         return 0;
  84 }
  85
  86 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
  87                                      struct sta_info *sta, struct sk_buff *skb)
  88 {
  89         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  90
  91         /* in case we are a client verify acm is not set for this ac */
  92         while (sdata->wmm_acm & BIT(skb->priority)) {
  93                 int ac = ieee802_1d_to_ac[skb->priority];
  94
  95                 if (ifmgd->tx_tspec[ac].admitted_time &&
  96                     skb->priority == ifmgd->tx_tspec[ac].up)
  97                         return ac;
  98
  99                 if (wme_downgrade_ac(skb)) {
 100                         /*
 101                          * This should not really happen. The AP has marked all
 102                          * lower ACs to require admission control which is not
 103                          * a reasonable configuration. Allow the frame to be
 104                          * transmitted using AC_BK as a workaround.
 105                          */
 106                         break;
 107                 }
 108         }
 109
 110         /* Check to see if this is a reserved TID */
 111         if (sta && sta->reserved_tid == skb->priority)
 112                 skb->priority = ieee80211_fix_reserved_tid(skb->priority);
 113
 114         /* look up which queue to use for frames with this 1d tag */
 115         return ieee802_1d_to_ac[skb->priority];
 116 }
 117
 118 /* Indicate which queue to use for this fully formed 802.11 frame */
 119 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
 120                                  struct sk_buff *skb,
 121                                  struct ieee80211_hdr *hdr)
 122 {
 123         struct ieee80211_local *local = sdata->local;
 124         u8 *p;
 125
 126         if (local->hw.queues < IEEE80211_NUM_ACS)
 127                 return 0;
 128
 129         if (!ieee80211_is_data(hdr->frame_control)) {
 130                 skb->priority = 7;
 131                 return ieee802_1d_to_ac[skb->priority];
 132         }
 133         if (!ieee80211_is_data_qos(hdr->frame_control)) {
 134                 skb->priority = 0;
 135                 return ieee802_1d_to_ac[skb->priority];
 136         }
 137
 138         p = ieee80211_get_qos_ctl(hdr);
 139         skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
 140
 141         return ieee80211_downgrade_queue(sdata, NULL, skb);
 142 }
 143
 144 /* Indicate which queue to use. */
 145 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 146                            struct sk_buff *skb)
 147 {
 148         struct ieee80211_local *local = sdata->local;
 149         struct sta_info *sta = NULL;
 150         const u8 *ra = NULL;
 151         bool qos = false;
 152         struct mac80211_qos_map *qos_map;
 153         u16 ret;
 154
 155         if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
 156                 skb->priority = 0; /* required for correct WPA/11i MIC */
 157                 return 0;
 158         }
 159
 160         rcu_read_lock();
 161         switch (sdata->vif.type) {
 162         case NL80211_IFTYPE_AP_VLAN:
 163                 sta = rcu_dereference(sdata->u.vlan.sta);
 164                 if (sta) {
 165                         qos = sta->sta.wme;
 166                         break;
 167                 }
 168         case NL80211_IFTYPE_AP:
 169                 ra = skb->data;
 170                 break;
 171         case NL80211_IFTYPE_WDS:
 172                 ra = sdata->u.wds.remote_addr;
 173                 break;
 174 #ifdef CONFIG_MAC80211_MESH
 175         case NL80211_IFTYPE_MESH_POINT:
 176                 qos = true;
 177                 break;
 178 #endif
 179         case NL80211_IFTYPE_STATION:
 180                 /* might be a TDLS station */
 181                 sta = sta_info_get(sdata, skb->data);
 182                 if (sta)
 183                         qos = sta->sta.wme;
 184
 185                 ra = sdata->u.mgd.bssid;
 186                 break;
 187         case NL80211_IFTYPE_ADHOC:
 188                 ra = skb->data;
 189                 break;
 190         case NL80211_IFTYPE_OCB:
 191                 /* all stations are required to support WME */
 192                 qos = true;
 193                 break;
 194         default:
 195                 break;
 196         }
 197
 198         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 199                 sta = sta_info_get(sdata, ra);
 200                 if (sta)
 201                         qos = sta->sta.wme;
 202         }
 203
 204         if (!qos) {
 205                 skb->priority = 0; /* required for correct WPA/11i MIC */
 206                 ret = IEEE80211_AC_BE;
 207                 goto out;
 208         }
 209
 210         if (skb->protocol == sdata->control_port_protocol) {
 211                 skb->priority = 7;
 212                 goto downgrade;
 213         }
 214
 215         /* use the data classifier to determine what 802.1d tag the
 216          * data frame has */
 217         qos_map = rcu_dereference(sdata->qos_map);
 218         skb->priority = cfg80211_classify8021d(skb, qos_map ?
 219                                                &qos_map->qos_map : NULL);
 220
 221  downgrade:
 222         ret = ieee80211_downgrade_queue(sdata, sta, skb);
 223  out:
 224         rcu_read_unlock();
 225         return ret;
 226 }
 227
 228 /**
 229  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
 230  *
 231  * @sdata: local subif
 232  * @skb: packet to be updated
 233  */
 234 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 235                            struct sk_buff *skb)
 236 {
 237         struct ieee80211_hdr *hdr = (void *)skb->data;
 238         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 239         u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 240         u8 flags;
 241         u8 *p;
 242
 243         if (!ieee80211_is_data_qos(hdr->frame_control))
 244                 return;
 245
 246         p = ieee80211_get_qos_ctl(hdr);
 247
 248         /* set up the first byte */
 249
 250         /*
 251          * preserve everything but the TID and ACK policy
 252          * (which we both write here)
 253          */
 254         flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
 255                        IEEE80211_QOS_CTL_ACK_POLICY_MASK);
 256
 257         if (is_multicast_ether_addr(hdr->addr1) ||
 258             sdata->noack_map & BIT(tid)) {
 259                 flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 260                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 261         }
 262
 263         *p = flags | tid;
 264
 265         /* set up the second byte */
 266         p++;
 267
 268         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 269                 /* preserve RSPI and Mesh PS Level bit */
 270                 *p &= ((IEEE80211_QOS_CTL_RSPI |
 271                         IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
 272
 273                 /* Nulls don't have a mesh header (frame body) */
 274                 if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
 275                         *p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
 276         } else {
 277                 *p = 0;
 278         }
 279 }