linux/net/mac80211/wme.c
Thomas Pedersen d3c1597b8d mac80211: fix forwarded mesh frame queue mapping
We can't rely on ieee80211_select_queue() to do its job at this point
since the skb->protocol is not yet known. Instead, factor out and reuse
the queue mapping logic for injected frames.

Also, to mitigate congestion, forwarded frames should be dropped if the
outgoing queue was stopped.  This was not correctly implemented as we
were not checking the right queue.  Furthermore, we were dropping frames
that had arrived to their destination if that queue was stopped.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-28 14:44:05 -05:00

190 lines
4.4 KiB
C

/*
* Copyright 2004, Instant802 Networks, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/pkt_sched.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "wme.h"
/* Default mapping in classifier to work with default
* queue setup.
*/
const int ieee802_1d_to_ac[8] = {
IEEE80211_AC_BE,
IEEE80211_AC_BK,
IEEE80211_AC_BK,
IEEE80211_AC_BE,
IEEE80211_AC_VI,
IEEE80211_AC_VI,
IEEE80211_AC_VO,
IEEE80211_AC_VO
};
static int wme_downgrade_ac(struct sk_buff *skb)
{
switch (skb->priority) {
case 6:
case 7:
skb->priority = 5; /* VO -> VI */
return 0;
case 4:
case 5:
skb->priority = 3; /* VI -> BE */
return 0;
case 0:
case 3:
skb->priority = 2; /* BE -> BK */
return 0;
default:
return -1;
}
}
/* Indicate which queue to use for this fully formed 802.11 frame */
u16 ieee80211_select_queue_80211(struct ieee80211_local *local,
struct sk_buff *skb,
struct ieee80211_hdr *hdr)
{
u8 *p;
if (local->hw.queues < 4)
return 0;
if (!ieee80211_is_data(hdr->frame_control)) {
skb->priority = 7;
return ieee802_1d_to_ac[skb->priority];
}
if (!ieee80211_is_data_qos(hdr->frame_control)) {
skb->priority = 0;
return ieee802_1d_to_ac[skb->priority];
}
p = ieee80211_get_qos_ctl(hdr);
skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
return ieee80211_downgrade_queue(local, skb);
}
/* Indicate which queue to use. */
u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta = NULL;
const u8 *ra = NULL;
bool qos = false;
if (local->hw.queues < 4 || skb->len < 6) {
skb->priority = 0; /* required for correct WPA/11i MIC */
return min_t(u16, local->hw.queues - 1, IEEE80211_AC_BE);
}
rcu_read_lock();
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
sta = rcu_dereference(sdata->u.vlan.sta);
if (sta) {
qos = test_sta_flag(sta, WLAN_STA_WME);
break;
}
case NL80211_IFTYPE_AP:
ra = skb->data;
break;
case NL80211_IFTYPE_WDS:
ra = sdata->u.wds.remote_addr;
break;
#ifdef CONFIG_MAC80211_MESH
case NL80211_IFTYPE_MESH_POINT:
qos = true;
break;
#endif
case NL80211_IFTYPE_STATION:
ra = sdata->u.mgd.bssid;
break;
case NL80211_IFTYPE_ADHOC:
ra = skb->data;
break;
default:
break;
}
if (!sta && ra && !is_multicast_ether_addr(ra)) {
sta = sta_info_get(sdata, ra);
if (sta)
qos = test_sta_flag(sta, WLAN_STA_WME);
}
rcu_read_unlock();
if (!qos) {
skb->priority = 0; /* required for correct WPA/11i MIC */
return IEEE80211_AC_BE;
}
/* use the data classifier to determine what 802.1d tag the
* data frame has */
skb->priority = cfg80211_classify8021d(skb);
return ieee80211_downgrade_queue(local, skb);
}
u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
struct sk_buff *skb)
{
/* in case we are a client verify acm is not set for this ac */
while (unlikely(local->wmm_acm & BIT(skb->priority))) {
if (wme_downgrade_ac(skb)) {
/*
* This should not really happen. The AP has marked all
* lower ACs to require admission control which is not
* a reasonable configuration. Allow the frame to be
* transmitted using AC_BK as a workaround.
*/
break;
}
}
/* look up which queue to use for frames with this 1d tag */
return ieee802_1d_to_ac[skb->priority];
}
void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (void *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
/* Fill in the QoS header if there is one. */
if (ieee80211_is_data_qos(hdr->frame_control)) {
u8 *p = ieee80211_get_qos_ctl(hdr);
u8 ack_policy, tid;
tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
/* preserve EOSP bit */
ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
if (is_multicast_ether_addr(hdr->addr1) ||
sdata->noack_map & BIT(tid)) {
ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
info->flags |= IEEE80211_TX_CTL_NO_ACK;
}
/* qos header is 2 bytes */
*p++ = ack_policy | tid;
*p = ieee80211_vif_is_mesh(&sdata->vif) ?
(IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) : 0;
}
}