From: Eliad Peller <eliad@xxxxxxxxxx>
add ieee80211_iter_keys_rcu() to iterate over uploaded
keys in atomic context (when rcu is locked)
The station removal code removes the keys only after
calling synchronize_net(), so it's not safe to iterate
the keys at this point (and postponing the actual key
deletion with call_rcu() might result in some
badly-ordered ops calls).
Add a flag to indicate a station is being removed,
and skip the configured keys if it's set.
Signed-off-by: Eliad Peller <eliadx.peller@xxxxxxxxx>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
---
include/net/mac80211.h | 24 +++++++++++++++++++++
net/mac80211/key.c | 56 +++++++++++++++++++++++++++++++++++++++++++++----
net/mac80211/sta_info.c | 1 +
net/mac80211/sta_info.h | 2 ++
4 files changed, 79 insertions(+), 4 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index f5a9571..bcb7022 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4916,6 +4916,30 @@ void ieee80211_iter_keys(struct ieee80211_hw *hw,
void *iter_data);
/**
+ * ieee80211_iter_keys_rcu - iterate keys programmed into the device
+ * @hw: pointer obtained from ieee80211_alloc_hw()
+ * @vif: virtual interface to iterate, may be %NULL for all
+ * @iter: iterator function that will be called for each key
+ * @iter_data: custom data to pass to the iterator function
+ *
+ * This function can be used to iterate all the keys known to
+ * mac80211, even those that weren't previously programmed into
+ * the device. Note that due to locking reasons, keys of station
+ * in removal process will be skipped.
+ *
+ * This function requires being called in an RCU critical section,
+ * and thus iter must be atomic.
+ */
+void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ void (*iter)(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta,
+ struct ieee80211_key_conf *key,
+ void *data),
+ void *iter_data);
+
+/**
* ieee80211_iter_chan_contexts_atomic - iterate channel contexts
* @hw: pointre obtained from ieee80211_alloc_hw().
* @iter: iterator function
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 44388d6..5e5bc59 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -4,6 +4,7 @@
* Copyright 2006-2007 Jiri Benc <jbenc@xxxxxxx>
* Copyright 2007-2008 Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
* Copyright 2013-2014 Intel Mobile Communications GmbH
+ * Copyright 2015 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
@@ -320,7 +321,7 @@ static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
return;
if (new)
- list_add_tail(&new->list, &sdata->key_list);
+ list_add_tail_rcu(&new->list, &sdata->key_list);
WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
@@ -368,7 +369,7 @@ static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
}
if (old)
- list_del(&old->list);
+ list_del_rcu(&old->list);
}
struct ieee80211_key *
@@ -592,8 +593,8 @@ static void ieee80211_key_destroy(struct ieee80211_key *key,
return;
/*
- * Synchronize so the TX path can no longer be using
- * this key before we free/remove it.
+ * Synchronize so the TX path and rcu key iterators
+ * can no longer be using this key before we free/remove it.
*/
synchronize_net();
@@ -744,6 +745,53 @@ void ieee80211_iter_keys(struct ieee80211_hw *hw,
}
EXPORT_SYMBOL(ieee80211_iter_keys);
+static void
+_ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
+ struct ieee80211_sub_if_data *sdata,
+ void (*iter)(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta,
+ struct ieee80211_key_conf *key,
+ void *data),
+ void *iter_data)
+{
+ struct ieee80211_key *key;
+
+ list_for_each_entry_rcu(key, &sdata->key_list, list) {
+ /* skip keys of station in removal process */
+ if (key->sta && key->sta->removed)
+ continue;
+ if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
+ continue;
+
+ iter(hw, &sdata->vif,
+ key->sta ? &key->sta->sta : NULL,
+ &key->conf, iter_data);
+ }
+}
+
+void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ void (*iter)(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta,
+ struct ieee80211_key_conf *key,
+ void *data),
+ void *iter_data)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+ struct ieee80211_sub_if_data *sdata;
+
+ if (vif) {
+ sdata = vif_to_sdata(vif);
+ _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
+ } else {
+ list_for_each_entry_rcu(sdata, &local->interfaces, list)
+ _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
+ }
+}
+EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
+
static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
struct list_head *keys)
{
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 723fa30..4402ad5 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -883,6 +883,7 @@ static int __must_check __sta_info_destroy_part1(struct sta_info *sta)
}
list_del_rcu(&sta->list);
+ sta->removed = true;
drv_sta_pre_rcu_remove(local, sta->sdata, sta);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 2cafb21..d605162 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -367,6 +367,7 @@ DECLARE_EWMA(signal, 1024, 8)
* @mesh: mesh STA information
* @debugfs: debug filesystem info
* @dead: set to true when sta is unlinked
+ * @removed: set to true when sta is being removed from sta_list
* @uploaded: set to true when sta is uploaded to the driver
* @sta: station information we share with the driver
* @sta_state: duplicates information about station state (for debug)
@@ -412,6 +413,7 @@ struct sta_info {
u16 listen_interval;
bool dead;
+ bool removed;
bool uploaded;
--
2.5.0
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