@@ -306,6 +306,8 @@ void ieee80211_set_bitrate_flags(struct wiphy *wiphy);
void cfg80211_bss_expire(struct cfg80211_registered_device *rdev);
void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
unsigned long age_secs);
+void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev,
+ struct ieee80211_channel *channel);
/* IBSS */
int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
@@ -16092,7 +16092,7 @@ void cfg80211_ch_switch_notify(struct net_device *dev,
if (wdev->iftype == NL80211_IFTYPE_STATION &&
!WARN_ON(!wdev->current_bss))
- wdev->current_bss->pub.channel = chandef->chan;
+ cfg80211_update_assoc_bss_entry(wdev, chandef->chan);
nl80211_ch_switch_notify(rdev, dev, chandef, GFP_KERNEL,
NL80211_CMD_CH_SWITCH_NOTIFY, 0);
@@ -2002,6 +2002,85 @@ void cfg80211_bss_iter(struct wiphy *wiphy,
}
EXPORT_SYMBOL(cfg80211_bss_iter);
+void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev,
+ struct ieee80211_channel *chan)
+{
+ struct wiphy *wiphy = wdev->wiphy;
+ struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+ struct cfg80211_internal_bss *cbss = wdev->current_bss;
+ struct cfg80211_internal_bss *new = NULL;
+ struct cfg80211_internal_bss *bss;
+ struct cfg80211_bss *nontrans_bss;
+ struct cfg80211_bss *tmp;
+
+ spin_lock_bh(&rdev->bss_lock);
+
+ if (WARN_ON(cbss->pub.channel == chan))
+ goto done;
+
+ /* use transmitting bss */
+ if (cbss->pub.transmitted_bss)
+ cbss = container_of(cbss->pub.transmitted_bss,
+ struct cfg80211_internal_bss,
+ pub);
+
+ cbss->pub.channel = chan;
+
+ list_for_each_entry(bss, &rdev->bss_list, list) {
+ if (!cfg80211_bss_type_match(bss->pub.capability,
+ bss->pub.channel->band,
+ wdev->conn_bss_type))
+ continue;
+
+ if (bss == cbss)
+ continue;
+
+ if (!cmp_bss(&bss->pub, &cbss->pub, BSS_CMP_REGULAR)) {
+ new = bss;
+ break;
+ }
+ }
+
+ if (new) {
+ /* to save time, update IEs for trasmitted bss only */
+ if (cfg80211_update_known_bss(rdev, cbss, new, false)) {
+ new->pub.proberesp_ies = NULL;
+ new->pub.beacon_ies = NULL;
+ }
+
+ list_for_each_entry_safe(nontrans_bss, tmp,
+ &new->pub.nontrans_list,
+ nontrans_list) {
+ bss = container_of(nontrans_bss,
+ struct cfg80211_internal_bss, pub);
+ if (__cfg80211_unlink_bss(rdev, bss))
+ rdev->bss_generation++;
+ }
+
+ WARN_ON(atomic_read(&new->hold));
+ if (!WARN_ON(!__cfg80211_unlink_bss(rdev, new)))
+ rdev->bss_generation++;
+ }
+
+ rb_erase(&cbss->rbn, &rdev->bss_tree);
+ rb_insert_bss(rdev, cbss);
+ rdev->bss_generation++;
+
+ list_for_each_entry_safe(nontrans_bss, tmp,
+ &cbss->pub.nontrans_list,
+ nontrans_list) {
+ bss = container_of(nontrans_bss,
+ struct cfg80211_internal_bss, pub);
+ bss->pub.channel = chan;
+ rb_erase(&bss->rbn, &rdev->bss_tree);
+ rb_insert_bss(rdev, bss);
+ rdev->bss_generation++;
+ }
+
+done:
+ spin_unlock_bh(&rdev->bss_lock);
+}
+
#ifdef CONFIG_CFG80211_WEXT
static struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
When associated BSS completes channel switch procedure, its channel record needs to be updated. The existing mac80211 solution was extended to cfg80211 in commit 5dc8cdce1d72 ("mac80211/cfg80211: update bss channel on channel switch") However that solution still appears to be incomplete as it may lead to duplicated scan entries for associated BSS after channel switch. The root cause of the problem is as follows. Each BSS entry is included into the following data structures: - bss list rdev->bss_list - bss search tree rdev->bss_tree Updating BSS channel record without rebuilding bss_tree may break tree search since cmp_bss considers all of the following: channel, bssid, ssid. When BSS channel is updated, but its location in bss_tree is not updated, then subsequent search operations may fail to locate this BSS since they will be traversing bss_tree in wrong direction. As a result, for scan performed after associated BSS channel switch, cfg80211_bss_update may add the second entry for the same BSS to both bss_list and bss_tree, rather then update the existing one. To summarize, if BSS channel needs to be updated, then bss_tree should be rebuilt in order to put updated BSS entry into a proper location. This commit suggests the following straightforward solution: - if new entry has been already created for BSS after channel switch, then use its IEs to update known BSS entry and then remove new entry completely - use rb_erase/rb_insert_bss reinstall updated BSS in bss_tree - update channel and location in rb-tree for non-transmitting bss entries Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com> --- Cover email is not attached to patchwork, so duplicate it here as well... Suggested approach to handle non-transmitting BSS entries is simplified in the following sense. If new entries have been already created after channel switch, only transmitting bss will be updated using IEs of new entry for the same transmitting bss. Non-transmitting bss entries will be updated as soon as new mgmt frames are received. Updating non-transmitting bss entries seems too expensive: nested nontrans_list traversing is needed since we can not rely on the same order of old and new non-transmitting entries. Basic use-case tested using both iwlwifi and qtnfmac. However multi-BSSID support has not yet been tested. v1 -> v2 - use IEs of new BSS entry to update known BSS entry for this purpose extract BSS update code from cfg80211_bss_update into a separate function cfg80211_update_known_bss v2 -> v3 - minor cleanup according to review comments - split cfg80211_update_known_bss function into a separate patch - update channel and location in rb-tree for nontransmit bss entries Regards, Sergey --- net/wireless/core.h | 2 ++ net/wireless/nl80211.c | 2 +- net/wireless/scan.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+), 1 deletion(-)