linux/net/mac80211/mesh_ps.c
Johannes Berg b9731062ce mac80211: mesh: fix potentially unaligned access
The pointer here points directly into the frame, so the
access is potentially unaligned. Use get_unaligned_le16
to avoid that.

Fixes: 3f52b7e328 ("mac80211: mesh power save basics")
Link: https://lore.kernel.org/r/20210920154009.3110ff75be0c.Ib6a2ff9e9cc9bc6fca50fce631ec1ce725cc926b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-09-23 13:25:09 +02:00

608 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
* Copyright 2012-2013, cozybit Inc.
* Copyright (C) 2021 Intel Corporation
*/
#include "mesh.h"
#include "wme.h"
/* mesh PS management */
/**
* mps_qos_null_get - create pre-addressed QoS Null frame for mesh powersave
* @sta: the station to get the frame for
*/
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 = 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;
nullfunc->seq_ctrl = 0;
/* no address resolution for this frame -> set addr 1 immediately */
memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
skb_put_zero(skb, 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
* @sta: the station to send to
*/
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->mesh->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->mesh->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
light_sleep_cnt++;
else if (sta->mesh->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->mesh->local_pm == pm)
return 0;
mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
pm, sta->sta.addr);
sta->mesh->local_pm = pm;
/*
* announce peer-specific power mode transition
* (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
*/
if (sta->mesh->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->mesh->plink_state == NL80211_PLINK_ESTAB)
pm = sta->mesh->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->mesh->plink_state == NL80211_PLINK_ESTAB &&
sta->mesh->peer_pm != NL80211_MESH_POWER_UNKNOWN)
pm = sta->mesh->peer_pm;
else
pm = sta->mesh->nonpeer_pm;
do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
/* clear the MPSP flags for non-peers or active STA */
if (sta->mesh->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->mesh->peer_pm == pm)
return;
mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
sta->sta.addr, pm);
sta->mesh->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->mesh->nonpeer_pm == pm)
return;
mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
sta->sta.addr, pm);
sta->mesh->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
* @sta: the station to handle
* @frames: the frame list to append to
*
* 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->control.flags |= IEEE80211_TX_INTCFL_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->mesh->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;
if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
sta->mesh->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 || !get_unaligned_le16(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->mesh->plink_state == NL80211_PLINK_ESTAB)
mpsp_trigger_send(sta, has_buffered, !buffer_local);
else
mps_frame_deliver(sta, 1);
}