From 3ab8227d3e7d1d2bf1829675d3197e3cb600e9f6 Mon Sep 17 00:00:00 2001 From: Sergey Matyukevich Date: Fri, 26 Jul 2019 16:39:32 +0000 Subject: [PATCH] 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(-) 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; -- 2.11.0