From 84f1772bc0c7bc26db9dbdbeabc4b1fa0ea1ace3 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 3 Jul 2019 15:38:21 +0200 Subject: cfg80211: clean up cfg80211_inform_single_bss_frame_data() cfg80211_inform_single_bss_frame_data() doesn't need the non_tx_data data argument since it's always NULL. Signed-off-by: Johannes Berg Reviewed-by: Sergey Matyukevich Link: https://lore.kernel.org/r/20190703133823.10530-1-johannes@sipsolutions.net Signed-off-by: Johannes Berg --- net/wireless/scan.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index d66e6d4b7555..70d061ed9cb6 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1776,7 +1776,6 @@ static struct cfg80211_bss * cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, struct ieee80211_mgmt *mgmt, size_t len, - struct cfg80211_non_tx_bss *non_tx_data, gfp_t gfp) { struct cfg80211_internal_bss tmp = {}, *res; @@ -1835,11 +1834,6 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, tmp.pub.chains = data->chains; memcpy(tmp.pub.chain_signal, data->chain_signal, IEEE80211_MAX_CHAINS); ether_addr_copy(tmp.parent_bssid, data->parent_bssid); - if (non_tx_data) { - tmp.pub.transmitted_bss = non_tx_data->tx_bss; - tmp.pub.bssid_index = non_tx_data->bssid_index; - tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; - } signal_valid = abs(data->chan->center_freq - channel->center_freq) <= wiphy->max_adj_channel_rssi_comp; @@ -1877,7 +1871,7 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy, struct cfg80211_non_tx_bss non_tx_data; res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt, - len, NULL, gfp); + len, gfp); if (!res || !wiphy->support_mbssid || !cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) return res; -- cgit v1.2.3 From b0d1d7ffc55571185e626a6ab2983400fc493cc2 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 3 Jul 2019 15:38:22 +0200 Subject: cfg80211: don't parse MBSSID if transmitting BSS isn't created Don't parse the multi-BSSID structures if we couldn't even create their transmitting BSS, this would confuse all of our tracking. This also means that non_tx_data->tx_bss will never be NULL, so we can clean up a little bit. Signed-off-by: Johannes Berg Reviewed-by: Sergey Matyukevich Link: https://lore.kernel.org/r/20190703133823.10530-2-johannes@sipsolutions.net Signed-off-by: Johannes Berg --- net/wireless/scan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 70d061ed9cb6..186ae1bb510a 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1440,7 +1440,7 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, regulatory_hint_found_beacon(wiphy, channel, gfp); } - if (non_tx_data && non_tx_data->tx_bss) { + if (non_tx_data) { /* this is a nontransmitting bss, we need to add it to * transmitting bss' list if it is not there */ @@ -1659,6 +1659,8 @@ cfg80211_inform_bss_data(struct wiphy *wiphy, res = cfg80211_inform_single_bss_data(wiphy, data, ftype, bssid, tsf, capability, beacon_interval, ie, ielen, NULL, gfp); + if (!res) + return NULL; non_tx_data.tx_bss = res; cfg80211_parse_mbssid_data(wiphy, data, ftype, bssid, tsf, beacon_interval, ie, ielen, &non_tx_data, -- cgit v1.2.3 From 60d7dfea00e14d87bdfd94cb7cca1f7592069fd4 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 3 Jul 2019 15:38:23 +0200 Subject: cfg80211: give all multi-BSSID BSS entries the same timestamp If we just read jiffies over and over again, a non-transmitting entry may have a newer timestamp than the transmitting one, leading to possible confusion on expiry. Give them all the same timestamp when creating them. Signed-off-by: Johannes Berg Reviewed-by: Sergey Matyukevich Link: https://lore.kernel.org/r/20190703133823.10530-3-johannes@sipsolutions.net Signed-off-by: Johannes Berg --- net/wireless/scan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 186ae1bb510a..a98dabab557a 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1368,6 +1368,7 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, struct cfg80211_internal_bss tmp = {}, *res; int bss_type; bool signal_valid; + unsigned long ts; if (WARN_ON(!wiphy)) return NULL; @@ -1390,8 +1391,11 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, tmp.ts_boottime = data->boottime_ns; if (non_tx_data) { tmp.pub.transmitted_bss = non_tx_data->tx_bss; + ts = bss_from_pub(non_tx_data->tx_bss)->ts; tmp.pub.bssid_index = non_tx_data->bssid_index; tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; + } else { + ts = jiffies; } /* @@ -1425,8 +1429,7 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, signal_valid = abs(data->chan->center_freq - channel->center_freq) <= wiphy->max_adj_channel_rssi_comp; - res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, - jiffies); + res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts); if (!res) return NULL; -- cgit v1.2.3 From 3ab8227d3e7d1d2bf1829675d3197e3cb600e9f6 Mon Sep 17 00:00:00 2001 From: Sergey Matyukevich Date: Fri, 26 Jul 2019 16:39:32 +0000 Subject: cfg80211: refactor cfg80211_bss_update This patch implements minor refactoring for cfg80211_bss_update function. Code path for updating known BSS is extracted into dedicated cfg80211_update_known_bss function. Signed-off-by: Sergey Matyukevich Link: https://lore.kernel.org/r/20190726163922.27509-2-sergey.matyukevich.os@quantenna.com Signed-off-by: Johannes Berg --- net/wireless/scan.c | 171 +++++++++++++++++++++++++++------------------------- 1 file changed, 89 insertions(+), 82 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index a98dabab557a..9119f5ce3677 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1091,6 +1091,93 @@ struct cfg80211_non_tx_bss { u8 bssid_index; }; +static bool +cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, + struct cfg80211_internal_bss *known, + struct cfg80211_internal_bss *new, + bool signal_valid) +{ + lockdep_assert_held(&rdev->bss_lock); + + /* Update IEs */ + if (rcu_access_pointer(new->pub.proberesp_ies)) { + const struct cfg80211_bss_ies *old; + + old = rcu_access_pointer(known->pub.proberesp_ies); + + rcu_assign_pointer(known->pub.proberesp_ies, + new->pub.proberesp_ies); + /* Override possible earlier Beacon frame IEs */ + rcu_assign_pointer(known->pub.ies, + new->pub.proberesp_ies); + if (old) + kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); + } else if (rcu_access_pointer(new->pub.beacon_ies)) { + const struct cfg80211_bss_ies *old; + struct cfg80211_internal_bss *bss; + + if (known->pub.hidden_beacon_bss && + !list_empty(&known->hidden_list)) { + const struct cfg80211_bss_ies *f; + + /* The known BSS struct is one of the probe + * response members of a group, but we're + * receiving a beacon (beacon_ies in the new + * bss is used). This can only mean that the + * AP changed its beacon from not having an + * SSID to showing it, which is confusing so + * drop this information. + */ + + f = rcu_access_pointer(new->pub.beacon_ies); + kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head); + return false; + } + + old = rcu_access_pointer(known->pub.beacon_ies); + + rcu_assign_pointer(known->pub.beacon_ies, new->pub.beacon_ies); + + /* Override IEs if they were from a beacon before */ + if (old == rcu_access_pointer(known->pub.ies)) + rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies); + + /* Assign beacon IEs to all sub entries */ + list_for_each_entry(bss, &known->hidden_list, hidden_list) { + const struct cfg80211_bss_ies *ies; + + ies = rcu_access_pointer(bss->pub.beacon_ies); + WARN_ON(ies != old); + + rcu_assign_pointer(bss->pub.beacon_ies, + new->pub.beacon_ies); + } + + if (old) + kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); + } + + known->pub.beacon_interval = new->pub.beacon_interval; + + /* don't update the signal if beacon was heard on + * adjacent channel. + */ + if (signal_valid) + known->pub.signal = new->pub.signal; + known->pub.capability = new->pub.capability; + known->ts = new->ts; + known->ts_boottime = new->ts_boottime; + known->parent_tsf = new->parent_tsf; + known->pub.chains = new->pub.chains; + memcpy(known->pub.chain_signal, new->pub.chain_signal, + IEEE80211_MAX_CHAINS); + ether_addr_copy(known->parent_bssid, new->parent_bssid); + known->pub.max_bssid_indicator = new->pub.max_bssid_indicator; + known->pub.bssid_index = new->pub.bssid_index; + + return true; +} + /* Returned bss is reference counted and must be cleaned up appropriately. */ struct cfg80211_internal_bss * cfg80211_bss_update(struct cfg80211_registered_device *rdev, @@ -1114,88 +1201,8 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR); if (found) { - /* Update IEs */ - if (rcu_access_pointer(tmp->pub.proberesp_ies)) { - const struct cfg80211_bss_ies *old; - - old = rcu_access_pointer(found->pub.proberesp_ies); - - rcu_assign_pointer(found->pub.proberesp_ies, - tmp->pub.proberesp_ies); - /* Override possible earlier Beacon frame IEs */ - rcu_assign_pointer(found->pub.ies, - tmp->pub.proberesp_ies); - if (old) - kfree_rcu((struct cfg80211_bss_ies *)old, - rcu_head); - } else if (rcu_access_pointer(tmp->pub.beacon_ies)) { - const struct cfg80211_bss_ies *old; - struct cfg80211_internal_bss *bss; - - if (found->pub.hidden_beacon_bss && - !list_empty(&found->hidden_list)) { - const struct cfg80211_bss_ies *f; - - /* - * The found BSS struct is one of the probe - * response members of a group, but we're - * receiving a beacon (beacon_ies in the tmp - * bss is used). This can only mean that the - * AP changed its beacon from not having an - * SSID to showing it, which is confusing so - * drop this information. - */ - - f = rcu_access_pointer(tmp->pub.beacon_ies); - kfree_rcu((struct cfg80211_bss_ies *)f, - rcu_head); - goto drop; - } - - old = rcu_access_pointer(found->pub.beacon_ies); - - rcu_assign_pointer(found->pub.beacon_ies, - tmp->pub.beacon_ies); - - /* Override IEs if they were from a beacon before */ - if (old == rcu_access_pointer(found->pub.ies)) - rcu_assign_pointer(found->pub.ies, - tmp->pub.beacon_ies); - - /* Assign beacon IEs to all sub entries */ - list_for_each_entry(bss, &found->hidden_list, - hidden_list) { - const struct cfg80211_bss_ies *ies; - - ies = rcu_access_pointer(bss->pub.beacon_ies); - WARN_ON(ies != old); - - rcu_assign_pointer(bss->pub.beacon_ies, - tmp->pub.beacon_ies); - } - - if (old) - kfree_rcu((struct cfg80211_bss_ies *)old, - rcu_head); - } - - found->pub.beacon_interval = tmp->pub.beacon_interval; - /* - * don't update the signal if beacon was heard on - * adjacent channel. - */ - if (signal_valid) - found->pub.signal = tmp->pub.signal; - found->pub.capability = tmp->pub.capability; - found->ts = tmp->ts; - found->ts_boottime = tmp->ts_boottime; - found->parent_tsf = tmp->parent_tsf; - found->pub.chains = tmp->pub.chains; - memcpy(found->pub.chain_signal, tmp->pub.chain_signal, - IEEE80211_MAX_CHAINS); - ether_addr_copy(found->parent_bssid, tmp->parent_bssid); - found->pub.max_bssid_indicator = tmp->pub.max_bssid_indicator; - found->pub.bssid_index = tmp->pub.bssid_index; + if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid)) + goto drop; } else { struct cfg80211_internal_bss *new; struct cfg80211_internal_bss *hidden; -- cgit v1.2.3 From 0afd425b1b64251f19b5d8d8b49bf56fefbc643f Mon Sep 17 00:00:00 2001 From: Sergey Matyukevich Date: Fri, 26 Jul 2019 16:39:34 +0000 Subject: cfg80211: fix duplicated scan entries after channel switch 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 - for nontransmit BSS entry, the whole transmit BSS hierarchy is updated Signed-off-by: Sergey Matyukevich Link: https://lore.kernel.org/r/20190726163922.27509-3-sergey.matyukevich.os@quantenna.com Signed-off-by: Johannes Berg --- net/wireless/core.h | 2 ++ net/wireless/nl80211.c | 2 +- net/wireless/scan.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+), 1 deletion(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/core.h b/net/wireless/core.h index ee8388fe4a92..77556c58d9ac 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -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, diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 10b57aa10227..a8d4b2b6b3ec 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -16116,7 +16116,7 @@ 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); diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 9119f5ce3677..d313c9befa23 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2001,6 +2001,85 @@ 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 transmitting 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) -- cgit v1.2.3