Skip to content

Commit

Permalink
mac80211: fix last RX rate data consistency
Browse files Browse the repository at this point in the history 
When storing the last_rate_* values in the RX code, there's nothing
to guarantee consistency, so a concurrent reader could see, e.g.
last_rate_idx on the new value, but last_rate_flag still on the old,
getting completely bogus values in the end.

To fix this, I lifted the sta_stats_encode_rate() function from my
old rate statistics code, which encodes the entire rate data into a
single 16-bit value, avoiding the consistency issue.

Signed-off-by: Johannes Berg <[email protected]>
  • Loading branch information
@jmberg-intel
jmberg-intel committed Apr 6, 2016
1 parent b8da6b6 commit 4f6b1b3
Show file tree
Hide file tree
Showing 3 changed files with 77 additions and 49 deletions.
21 changes: 5 additions & 16 deletions net/mac80211/rx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1421,16 +1421,9 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
sta->rx_stats.last_rx = jiffies;
if (ieee80211_is_data(hdr->frame_control) &&
!is_multicast_ether_addr(hdr->addr1)) {
sta->rx_stats.last_rate_idx =
status->rate_idx;
sta->rx_stats.last_rate_flag =
status->flag;
sta->rx_stats.last_rate_vht_flag =
status->vht_flag;
sta->rx_stats.last_rate_vht_nss =
status->vht_nss;
}
!is_multicast_ether_addr(hdr->addr1))
sta->rx_stats.last_rate =
sta_stats_encode_rate(status);
}
} else if (rx->sdata->vif.type == NL80211_IFTYPE_OCB) {
sta->rx_stats.last_rx = jiffies;
Expand All @@ -1440,12 +1433,8 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
* match the current local configuration when processed.
*/
sta->rx_stats.last_rx = jiffies;
if (ieee80211_is_data(hdr->frame_control)) {
sta->rx_stats.last_rate_idx = status->rate_idx;
sta->rx_stats.last_rate_flag = status->flag;
sta->rx_stats.last_rate_vht_flag = status->vht_flag;
sta->rx_stats.last_rate_vht_nss = status->vht_nss;
}
if (ieee80211_is_data(hdr->frame_control))
sta->rx_stats.last_rate = sta_stats_encode_rate(status);
}

if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
Expand Down
60 changes: 32 additions & 28 deletions net/mac80211/sta_info.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1928,43 +1928,47 @@ u8 sta_info_tx_streams(struct sta_info *sta)
>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
}

static void sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo)
static void sta_stats_decode_rate(struct ieee80211_local *local, u16 rate,
struct rate_info *rinfo)
{
rinfo->flags = 0;

if (sta->rx_stats.last_rate_flag & RX_FLAG_HT) {
rinfo->flags |= RATE_INFO_FLAGS_MCS;
rinfo->mcs = sta->rx_stats.last_rate_idx;
} else if (sta->rx_stats.last_rate_flag & RX_FLAG_VHT) {
rinfo->flags |= RATE_INFO_FLAGS_VHT_MCS;
rinfo->nss = sta->rx_stats.last_rate_vht_nss;
rinfo->mcs = sta->rx_stats.last_rate_idx;
} else {
rinfo->bw = (rate & STA_STATS_RATE_BW_MASK) >>
STA_STATS_RATE_BW_SHIFT;

if (rate & STA_STATS_RATE_VHT) {
rinfo->flags = RATE_INFO_FLAGS_VHT_MCS;
rinfo->mcs = rate & 0xf;
rinfo->nss = (rate & 0xf0) >> 4;
} else if (rate & STA_STATS_RATE_HT) {
rinfo->flags = RATE_INFO_FLAGS_MCS;
rinfo->mcs = rate & 0xff;
} else if (rate & STA_STATS_RATE_LEGACY) {
struct ieee80211_supported_band *sband;
int shift = ieee80211_vif_get_shift(&sta->sdata->vif);
u16 brate;

sband = sta->local->hw.wiphy->bands[
ieee80211_get_sdata_band(sta->sdata)];
brate = sband->bitrates[sta->rx_stats.last_rate_idx].bitrate;
unsigned int shift;

sband = local->hw.wiphy->bands[(rate >> 4) & 0xf];
brate = sband->bitrates[rate & 0xf].bitrate;
if (rinfo->bw == RATE_INFO_BW_5)
shift = 2;
else if (rinfo->bw == RATE_INFO_BW_10)
shift = 1;
else
shift = 0;
rinfo->legacy = DIV_ROUND_UP(brate, 1 << shift);
}

if (sta->rx_stats.last_rate_flag & RX_FLAG_SHORT_GI)
if (rate & STA_STATS_RATE_SGI)
rinfo->flags |= RATE_INFO_FLAGS_SHORT_GI;
}

static void sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo)
{
u16 rate = ACCESS_ONCE(sta->rx_stats.last_rate);

if (sta->rx_stats.last_rate_flag & RX_FLAG_5MHZ)
rinfo->bw = RATE_INFO_BW_5;
else if (sta->rx_stats.last_rate_flag & RX_FLAG_10MHZ)
rinfo->bw = RATE_INFO_BW_10;
else if (sta->rx_stats.last_rate_flag & RX_FLAG_40MHZ)
rinfo->bw = RATE_INFO_BW_40;
else if (sta->rx_stats.last_rate_vht_flag & RX_VHT_FLAG_80MHZ)
rinfo->bw = RATE_INFO_BW_80;
else if (sta->rx_stats.last_rate_vht_flag & RX_VHT_FLAG_160MHZ)
rinfo->bw = RATE_INFO_BW_160;
if (rate == STA_STATS_RATE_INVALID)
rinfo->flags = 0;
else
rinfo->bw = RATE_INFO_BW_20;
sta_stats_decode_rate(sta->local, rate, rinfo);
}

void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
Expand Down
45 changes: 40 additions & 5 deletions net/mac80211/sta_info.h
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/*
* Copyright 2002-2005, Devicescape Software, Inc.
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright(c) 2015 Intel Deutschland GmbH
* Copyright(c) 2015-2016 Intel Deutschland GmbH
*
* 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
Expand Down Expand Up @@ -452,10 +452,7 @@ struct sta_info {
int last_signal;
u8 chains;
s8 chain_signal_last[IEEE80211_MAX_CHAINS];
int last_rate_idx;
u32 last_rate_flag;
u32 last_rate_vht_flag;
u8 last_rate_vht_nss;
u16 last_rate;
u64 msdu[IEEE80211_NUM_TIDS + 1];
} rx_stats;
struct {
Expand Down Expand Up @@ -683,4 +680,42 @@ void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta);

unsigned long ieee80211_sta_last_active(struct sta_info *sta);

#define STA_STATS_RATE_INVALID 0
#define STA_STATS_RATE_VHT 0x8000
#define STA_STATS_RATE_HT 0x4000
#define STA_STATS_RATE_LEGACY 0x2000
#define STA_STATS_RATE_SGI 0x1000
#define STA_STATS_RATE_BW_SHIFT 9
#define STA_STATS_RATE_BW_MASK (0x7 << STA_STATS_RATE_BW_SHIFT)

static inline u16 sta_stats_encode_rate(struct ieee80211_rx_status *s)
{
u16 r = s->rate_idx;

if (s->vht_flag & RX_VHT_FLAG_80MHZ)
r |= RATE_INFO_BW_80 << STA_STATS_RATE_BW_SHIFT;
else if (s->vht_flag & RX_VHT_FLAG_160MHZ)
r |= RATE_INFO_BW_160 << STA_STATS_RATE_BW_SHIFT;
else if (s->flag & RX_FLAG_40MHZ)
r |= RATE_INFO_BW_40 << STA_STATS_RATE_BW_SHIFT;
else if (s->flag & RX_FLAG_10MHZ)
r |= RATE_INFO_BW_10 << STA_STATS_RATE_BW_SHIFT;
else if (s->flag & RX_FLAG_5MHZ)
r |= RATE_INFO_BW_5 << STA_STATS_RATE_BW_SHIFT;
else
r |= RATE_INFO_BW_20 << STA_STATS_RATE_BW_SHIFT;

if (s->flag & RX_FLAG_SHORT_GI)
r |= STA_STATS_RATE_SGI;

if (s->flag & RX_FLAG_VHT)
r |= STA_STATS_RATE_VHT | (s->vht_nss << 4);
else if (s->flag & RX_FLAG_HT)
r |= STA_STATS_RATE_HT;
else
r |= STA_STATS_RATE_LEGACY | (s->band << 4);

return r;
}

#endif /* STA_INFO_H */

0 comments on commit 4f6b1b3

Please sign in to comment.