From: Ben Greear <[email protected]>
Best link is the link with the highest state (ie, associated)
and if multiple links have same state, the highest
frequency wins.
This makes current ethtool stats more useful. Per-link
ethtool stats can be added later.
Signed-off-by: Ben Greear <[email protected]>
---
v3: Fix glaring bug in ieee80211_find_best_sta_link that would
have crashed on 2+ links.
Re-work locking slightly in ethtool.c: Cannot hold rcu_read_lock
while calling sta_set_sinfo. I'm hoping the wiphy_lock means that
link and/or sta cannot go away while this method is being traversed,
otherwise the rcu read lock/unlock around ieee80211_find_best_sta_link
is probably not sufficient.
net/mac80211/ethtool.c | 12 +++++++--
net/mac80211/link.c | 56 +++++++++++++++++++++++++++++++++++++++++
net/mac80211/sta_info.h | 4 +++
3 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/net/mac80211/ethtool.c b/net/mac80211/ethtool.c
index 99f6174a9d69..3d12111996e5 100644
--- a/net/mac80211/ethtool.c
+++ b/net/mac80211/ethtool.c
@@ -83,6 +83,7 @@ static void ieee80211_get_stats(struct net_device *dev,
struct ieee80211_local *local = sdata->local;
struct station_info sinfo;
struct survey_info survey;
+ struct ieee80211_link_data *link = NULL;
int i, q;
#define STA_STATS_SURVEY_LEN 7
@@ -112,12 +113,17 @@ static void ieee80211_get_stats(struct net_device *dev,
wiphy_lock(local->hw.wiphy);
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
- sta = sta_info_get_bss(sdata, sdata->deflink.u.mgd.bssid);
+ rcu_read_lock();
+ sta = ieee80211_find_best_sta_link(sdata, &link);
+ rcu_read_unlock();
if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
goto do_survey;
memset(&sinfo, 0, sizeof(sinfo));
+ /* sta_set_sinfo cannot hold rcu read lock since it can block
+ * calling into firmware for stats.
+ */
sta_set_sinfo(sta, &sinfo, false);
i = 0;
@@ -158,7 +164,9 @@ static void ieee80211_get_stats(struct net_device *dev,
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
- if (chanctx_conf)
+ if (link)
+ channel = link->conf->chandef.chan;
+ else if (chanctx_conf)
channel = chanctx_conf->def.chan;
else
channel = NULL;
diff --git a/net/mac80211/link.c b/net/mac80211/link.c
index bf7bd880d062..2dc0f46ee053 100644
--- a/net/mac80211/link.c
+++ b/net/mac80211/link.c
@@ -115,6 +115,62 @@ static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
kfree(links[link_id]);
}
+/* For cases where we need a link for stats and such, and just want
+ * a 'good' one.
+ */
+struct sta_info *
+ieee80211_find_best_sta_link(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_link_data **link)
+{
+ struct ieee80211_link_data *best_link = NULL;
+ struct sta_info *best_sta = NULL;
+ int i;
+
+ for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
+ struct ieee80211_link_data *link1;
+ struct sta_info *sta1;
+ bool sta1_better = false;
+
+ link1 = sdata_dereference(sdata->link[i], sdata);
+ if (!link1)
+ continue;
+ if (!best_link) {
+ best_link = link1;
+ best_sta = sta_info_get_bss(sdata, best_link->u.mgd.bssid);
+ continue;
+ }
+
+ sta1 = sta_info_get_bss(sdata, link1->u.mgd.bssid);
+ if (!sta1)
+ continue;
+
+ /* we have two potential best links, find one we like best. */
+ if (!best_sta || sta1->sta_state > best_sta->sta_state) {
+ sta1_better = true;
+ } else if (sta1->sta_state == best_sta->sta_state) {
+ u32 freq_best = 0;
+ u32 freq1 = 0;
+
+ if (best_link->conf->chandef.chan)
+ freq_best = best_link->conf->chandef.chan->center_freq;
+ if (link1->conf->chandef.chan)
+ freq1 = link1->conf->chandef.chan->center_freq;
+ if (freq1 > freq_best)
+ sta1_better = true;
+ }
+
+ if (sta1_better) {
+ best_sta = sta1;
+ best_link = link1;
+ }
+ }
+
+ *link = best_link;
+ if (best_link)
+ return sta_info_get_bss(sdata, best_link->u.mgd.bssid);
+ return sta_info_get_bss(sdata, sdata->deflink.u.mgd.bssid);
+}
+
static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
{
unsigned int i, j;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 7acf2223e47a..c57380b622e6 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -929,6 +929,10 @@ void ieee80211_sta_set_max_amsdu_subframes(struct sta_info *sta,
void __ieee80211_sta_recalc_aggregates(struct sta_info *sta, u16 active_links);
+struct sta_info *
+ieee80211_find_best_sta_link(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_link_data **link);
+
enum sta_stats_type {
STA_STATS_RATE_TYPE_INVALID = 0,
STA_STATS_RATE_TYPE_LEGACY,
--
2.40.0