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Commit ef044763 authored by Eliad Peller's avatar Eliad Peller Committed by Johannes Berg
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mac80211: add atomic uploaded keys iterator 



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: default avatarEliad Peller <eliadx.peller@intel.com>
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 0ead2510

include/net/mac80211.h

+24 −0
Original line number Diff line number Diff line
@@ -4917,6 +4917,30 @@ void ieee80211_iter_keys(struct ieee80211_hw *hw, 
				      void *data),

			 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().

net/mac80211/key.c

+52 −4
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>

 * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>

 * 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)

{

net/mac80211/sta_info.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

net/mac80211/sta_info.h

+2 −0
Original line number Diff line number Diff line
@@ -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;