linux/net/mac80211/mesh_ps.c
Marco Porsch 446075d76b mac80211: fixes for mesh powersave logic
This patch fixes errors in the mesh powersave logic which
cause that remote peers do not get peer power mode change
notifications and mesh peer service periods (MPSPs) got
stuck.

When closing a peer link, set the (now invalid) peer-specific
power mode to 'unknown'.

Avoid overhead when local power mode is unchanged.

Reliably clear MPSP flags on peering status update.

Avoid MPSP flags getting stuck by not requesting a further
MPSP ownership if we already are an MPSP owner.

Signed-off-by: Marco Porsch <marco@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-10-28 15:05:26 +01:00

606 lines
16 KiB
C

/*
* Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
* Copyright 2012-2013, cozybit 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 "mesh.h"
#include "wme.h"
/* mesh PS management */
/**
* mps_qos_null_get - create pre-addressed QoS Null frame for mesh powersave
*/
static struct sk_buff *mps_qos_null_get(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
struct ieee80211_hdr *nullfunc; /* use 4addr header */
struct sk_buff *skb;
int size = sizeof(*nullfunc);
__le16 fc;
skb = dev_alloc_skb(local->hw.extra_tx_headroom + size + 2);
if (!skb)
return NULL;
skb_reserve(skb, local->hw.extra_tx_headroom);
nullfunc = (struct ieee80211_hdr *) skb_put(skb, size);
fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_NULLFUNC);
ieee80211_fill_mesh_addresses(nullfunc, &fc, sta->sta.addr,
sdata->vif.addr);
nullfunc->frame_control = fc;
nullfunc->duration_id = 0;
/* no address resolution for this frame -> set addr 1 immediately */
memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
memset(skb_put(skb, 2), 0, 2); /* append QoS control field */
ieee80211_mps_set_frame_flags(sdata, sta, nullfunc);
return skb;
}
/**
* mps_qos_null_tx - send a QoS Null to indicate link-specific power mode
*/
static void mps_qos_null_tx(struct sta_info *sta)
{
struct sk_buff *skb;
skb = mps_qos_null_get(sta);
if (!skb)
return;
mps_dbg(sta->sdata, "announcing peer-specific power mode to %pM\n",
sta->sta.addr);
/* don't unintentionally start a MPSP */
if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
u8 *qc = ieee80211_get_qos_ctl((void *) skb->data);
qc[0] |= IEEE80211_QOS_CTL_EOSP;
}
ieee80211_tx_skb(sta->sdata, skb);
}
/**
* ieee80211_mps_local_status_update - track status of local link-specific PMs
*
* @sdata: local mesh subif
*
* sets the non-peer power mode and triggers the driver PS (re-)configuration
* Return BSS_CHANGED_BEACON if a beacon update is necessary.
*/
u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct sta_info *sta;
bool peering = false;
int light_sleep_cnt = 0;
int deep_sleep_cnt = 0;
u32 changed = 0;
enum nl80211_mesh_power_mode nonpeer_pm;
rcu_read_lock();
list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
if (sdata != sta->sdata)
continue;
switch (sta->plink_state) {
case NL80211_PLINK_OPN_SNT:
case NL80211_PLINK_OPN_RCVD:
case NL80211_PLINK_CNF_RCVD:
peering = true;
break;
case NL80211_PLINK_ESTAB:
if (sta->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
light_sleep_cnt++;
else if (sta->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
deep_sleep_cnt++;
break;
default:
break;
}
}
rcu_read_unlock();
/*
* Set non-peer mode to active during peering/scanning/authentication
* (see IEEE802.11-2012 13.14.8.3). The non-peer mesh power mode is
* deep sleep if the local STA is in light or deep sleep towards at
* least one mesh peer (see 13.14.3.1). Otherwise, set it to the
* user-configured default value.
*/
if (peering) {
mps_dbg(sdata, "setting non-peer PM to active for peering\n");
nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
} else if (light_sleep_cnt || deep_sleep_cnt) {
mps_dbg(sdata, "setting non-peer PM to deep sleep\n");
nonpeer_pm = NL80211_MESH_POWER_DEEP_SLEEP;
} else {
mps_dbg(sdata, "setting non-peer PM to user value\n");
nonpeer_pm = ifmsh->mshcfg.power_mode;
}
/* need update if sleep counts move between 0 and non-zero */
if (ifmsh->nonpeer_pm != nonpeer_pm ||
!ifmsh->ps_peers_light_sleep != !light_sleep_cnt ||
!ifmsh->ps_peers_deep_sleep != !deep_sleep_cnt)
changed = BSS_CHANGED_BEACON;
ifmsh->nonpeer_pm = nonpeer_pm;
ifmsh->ps_peers_light_sleep = light_sleep_cnt;
ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;
return changed;
}
/**
* ieee80211_mps_set_sta_local_pm - set local PM towards a mesh STA
*
* @sta: mesh STA
* @pm: the power mode to set
* Return BSS_CHANGED_BEACON if a beacon update is in order.
*/
u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
enum nl80211_mesh_power_mode pm)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
if (sta->local_pm == pm)
return 0;
mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
pm, sta->sta.addr);
sta->local_pm = pm;
/*
* announce peer-specific power mode transition
* (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
*/
if (sta->plink_state == NL80211_PLINK_ESTAB)
mps_qos_null_tx(sta);
return ieee80211_mps_local_status_update(sdata);
}
/**
* ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
*
* @sdata: local mesh subif
* @sta: mesh STA
* @hdr: 802.11 frame header
*
* see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
*
* NOTE: sta must be given when an individually-addressed QoS frame header
* is handled, for group-addressed and management frames it is not used
*/
void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
struct ieee80211_hdr *hdr)
{
enum nl80211_mesh_power_mode pm;
u8 *qc;
if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
ieee80211_is_data_qos(hdr->frame_control) &&
!sta))
return;
if (is_unicast_ether_addr(hdr->addr1) &&
ieee80211_is_data_qos(hdr->frame_control) &&
sta->plink_state == NL80211_PLINK_ESTAB)
pm = sta->local_pm;
else
pm = sdata->u.mesh.nonpeer_pm;
if (pm == NL80211_MESH_POWER_ACTIVE)
hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
else
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
if (!ieee80211_is_data_qos(hdr->frame_control))
return;
qc = ieee80211_get_qos_ctl(hdr);
if ((is_unicast_ether_addr(hdr->addr1) &&
pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
(is_multicast_ether_addr(hdr->addr1) &&
sdata->u.mesh.ps_peers_deep_sleep > 0))
qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
else
qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
}
/**
* ieee80211_mps_sta_status_update - update buffering status of neighbor STA
*
* @sta: mesh STA
*
* called after change of peering status or non-peer/peer-specific power mode
*/
void ieee80211_mps_sta_status_update(struct sta_info *sta)
{
enum nl80211_mesh_power_mode pm;
bool do_buffer;
/* For non-assoc STA, prevent buffering or frame transmission */
if (sta->sta_state < IEEE80211_STA_ASSOC)
return;
/*
* use peer-specific power mode if peering is established and the
* peer's power mode is known
*/
if (sta->plink_state == NL80211_PLINK_ESTAB &&
sta->peer_pm != NL80211_MESH_POWER_UNKNOWN)
pm = sta->peer_pm;
else
pm = sta->nonpeer_pm;
do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
/* clear the MPSP flags for non-peers or active STA */
if (sta->plink_state != NL80211_PLINK_ESTAB) {
clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
} else if (!do_buffer) {
clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
}
/* Don't let the same PS state be set twice */
if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
return;
if (do_buffer) {
set_sta_flag(sta, WLAN_STA_PS_STA);
atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
sta->sta.addr);
} else {
ieee80211_sta_ps_deliver_wakeup(sta);
}
}
static void mps_set_sta_peer_pm(struct sta_info *sta,
struct ieee80211_hdr *hdr)
{
enum nl80211_mesh_power_mode pm;
u8 *qc = ieee80211_get_qos_ctl(hdr);
/*
* Test Power Management field of frame control (PW) and
* mesh power save level subfield of QoS control field (PSL)
*
* | PM | PSL| Mesh PM |
* +----+----+---------+
* | 0 |Rsrv| Active |
* | 1 | 0 | Light |
* | 1 | 1 | Deep |
*/
if (ieee80211_has_pm(hdr->frame_control)) {
if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
pm = NL80211_MESH_POWER_DEEP_SLEEP;
else
pm = NL80211_MESH_POWER_LIGHT_SLEEP;
} else {
pm = NL80211_MESH_POWER_ACTIVE;
}
if (sta->peer_pm == pm)
return;
mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
sta->sta.addr, pm);
sta->peer_pm = pm;
ieee80211_mps_sta_status_update(sta);
}
static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
struct ieee80211_hdr *hdr)
{
enum nl80211_mesh_power_mode pm;
if (ieee80211_has_pm(hdr->frame_control))
pm = NL80211_MESH_POWER_DEEP_SLEEP;
else
pm = NL80211_MESH_POWER_ACTIVE;
if (sta->nonpeer_pm == pm)
return;
mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
sta->sta.addr, pm);
sta->nonpeer_pm = pm;
ieee80211_mps_sta_status_update(sta);
}
/**
* ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
*
* @sta: STA info that transmitted the frame
* @hdr: IEEE 802.11 (QoS) Header
*/
void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
struct ieee80211_hdr *hdr)
{
if (is_unicast_ether_addr(hdr->addr1) &&
ieee80211_is_data_qos(hdr->frame_control)) {
/*
* individually addressed QoS Data/Null frames contain
* peer link-specific PS mode towards the local STA
*/
mps_set_sta_peer_pm(sta, hdr);
/* check for mesh Peer Service Period trigger frames */
ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
sta, false, false);
} else {
/*
* can only determine non-peer PS mode
* (see IEEE802.11-2012 8.2.4.1.7)
*/
mps_set_sta_nonpeer_pm(sta, hdr);
}
}
/* mesh PS frame release */
static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct sk_buff *skb;
struct ieee80211_hdr *nullfunc;
struct ieee80211_tx_info *info;
u8 *qc;
skb = mps_qos_null_get(sta);
if (!skb)
return;
nullfunc = (struct ieee80211_hdr *) skb->data;
if (!eosp)
nullfunc->frame_control |=
cpu_to_le16(IEEE80211_FCTL_MOREDATA);
/*
* | RSPI | EOSP | MPSP triggering |
* +------+------+--------------------+
* | 0 | 0 | local STA is owner |
* | 0 | 1 | no MPSP (MPSP end) |
* | 1 | 0 | both STA are owner |
* | 1 | 1 | peer STA is owner | see IEEE802.11-2012 13.14.9.2
*/
qc = ieee80211_get_qos_ctl(nullfunc);
if (rspi)
qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
if (eosp)
qc[0] |= IEEE80211_QOS_CTL_EOSP;
info = IEEE80211_SKB_CB(skb);
info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
IEEE80211_TX_CTL_REQ_TX_STATUS;
mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
ieee80211_tx_skb(sdata, skb);
}
/**
* mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
*
* To properly end a mesh MPSP the last transmitted frame has to set the EOSP
* flag in the QoS Control field. In case the current tailing frame is not a
* QoS Data frame, append a QoS Null to carry the flag.
*/
static void mpsp_qos_null_append(struct sta_info *sta,
struct sk_buff_head *frames)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_tx_info *info;
if (ieee80211_is_data_qos(hdr->frame_control))
return;
new_skb = mps_qos_null_get(sta);
if (!new_skb)
return;
mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
sta->sta.addr);
/*
* This frame has to be transmitted last. Assign lowest priority to
* make sure it cannot pass other frames when releasing multiple ACs.
*/
new_skb->priority = 1;
skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
ieee80211_set_qos_hdr(sdata, new_skb);
info = IEEE80211_SKB_CB(new_skb);
info->control.vif = &sdata->vif;
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
__skb_queue_tail(frames, new_skb);
}
/**
* mps_frame_deliver - transmit frames during mesh powersave
*
* @sta: STA info to transmit to
* @n_frames: number of frames to transmit. -1 for all
*/
static void mps_frame_deliver(struct sta_info *sta, int n_frames)
{
struct ieee80211_local *local = sta->sdata->local;
int ac;
struct sk_buff_head frames;
struct sk_buff *skb;
bool more_data = false;
skb_queue_head_init(&frames);
/* collect frame(s) from buffers */
for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
while (n_frames != 0) {
skb = skb_dequeue(&sta->tx_filtered[ac]);
if (!skb) {
skb = skb_dequeue(
&sta->ps_tx_buf[ac]);
if (skb)
local->total_ps_buffered--;
}
if (!skb)
break;
n_frames--;
__skb_queue_tail(&frames, skb);
}
if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
!skb_queue_empty(&sta->ps_tx_buf[ac]))
more_data = true;
}
/* nothing to send? -> EOSP */
if (skb_queue_empty(&frames)) {
mpsp_trigger_send(sta, false, true);
return;
}
/* in a MPSP make sure the last skb is a QoS Data frame */
if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
mpsp_qos_null_append(sta, &frames);
mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
skb_queue_len(&frames), sta->sta.addr);
/* prepare collected frames for transmission */
skb_queue_walk(&frames, skb) {
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (void *) skb->data;
/*
* Tell TX path to send this frame even though the
* STA may still remain is PS mode after this frame
* exchange.
*/
info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
if (more_data || !skb_queue_is_last(&frames, skb))
hdr->frame_control |=
cpu_to_le16(IEEE80211_FCTL_MOREDATA);
else
hdr->frame_control &=
cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
if (skb_queue_is_last(&frames, skb) &&
ieee80211_is_data_qos(hdr->frame_control)) {
u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
/* MPSP trigger frame ends service period */
*qoshdr |= IEEE80211_QOS_CTL_EOSP;
info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
}
}
ieee80211_add_pending_skbs(local, &frames);
sta_info_recalc_tim(sta);
}
/**
* ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
*
* @qc: QoS Control field
* @sta: peer to start a MPSP with
* @tx: frame was transmitted by the local STA
* @acked: frame has been transmitted successfully
*
* NOTE: active mode STA may only serve as MPSP owner
*/
void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
bool tx, bool acked)
{
u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
if (tx) {
if (rspi && acked)
set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
if (eosp)
clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
else if (acked &&
test_sta_flag(sta, WLAN_STA_PS_STA) &&
!test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
mps_frame_deliver(sta, -1);
} else {
if (eosp)
clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
else if (sta->local_pm != NL80211_MESH_POWER_ACTIVE)
set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
mps_frame_deliver(sta, -1);
}
}
/**
* ieee80211_mps_frame_release - release frames buffered due to mesh power save
*
* @sta: mesh STA
* @elems: IEs of beacon or probe response
*
* For peers if we have individually-addressed frames buffered or the peer
* indicates buffered frames, send a corresponding MPSP trigger frame. Since
* we do not evaluate the awake window duration, QoS Nulls are used as MPSP
* trigger frames. If the neighbour STA is not a peer, only send single frames.
*/
void ieee80211_mps_frame_release(struct sta_info *sta,
struct ieee802_11_elems *elems)
{
int ac, buffer_local = 0;
bool has_buffered = false;
/* TIM map only for LLID <= IEEE80211_MAX_AID */
if (sta->plink_state == NL80211_PLINK_ESTAB)
has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
le16_to_cpu(sta->llid) % IEEE80211_MAX_AID);
if (has_buffered)
mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
sta->sta.addr);
/* only transmit to PS STA with announced, non-zero awake window */
if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
(!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
return;
if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
skb_queue_len(&sta->tx_filtered[ac]);
if (!has_buffered && !buffer_local)
return;
if (sta->plink_state == NL80211_PLINK_ESTAB)
mpsp_trigger_send(sta, has_buffered, !buffer_local);
else
mps_frame_deliver(sta, 1);
}