net/mac80211/key.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2002-2005, Instant802 Networks, Inc.
  * Copyright 2005-2006, Devicescape Software, Inc.
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>
  *
  * 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
  * published by the Free Software Foundation.
  */

 #include <linux/if_ether.h>
 #include <linux/etherdevice.h>
 #include <linux/list.h>
 #include <linux/rcupdate.h>
 #include <linux/rtnetlink.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <net/mac80211.h>
 #include <asm/unaligned.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 #include "debugfs_key.h"
 #include "aes_ccm.h"
 #include "aes_cmac.h"


 /**
  * DOC: Key handling basics
  *
  * Key handling in mac80211 is done based on per-interface (sub_if_data)
  * keys and per-station keys. Since each station belongs to an interface,
  * each station key also belongs to that interface.
  *
  * Hardware acceleration is done on a best-effort basis for algorithms
  * that are implemented in software,  for each key the hardware is asked
  * to enable that key for offloading but if it cannot do that the key is
  * simply kept for software encryption (unless it is for an algorithm
  * that isn't implemented in software).
  * There is currently no way of knowing whether a key is handled in SW
  * or HW except by looking into debugfs.
  *
  * All key management is internally protected by a mutex. Within all
  * other parts of mac80211, key references are, just as STA structure
  * references, protected by RCU. Note, however, that some things are
  * unprotected, namely the key->sta dereferences within the hardware
  * acceleration functions. This means that sta_info_destroy() must
  * remove the key which waits for an RCU grace period.
  */

 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

 static void assert_key_lock(struct ieee80211_local *local)
 {
 	lockdep_assert_held(&local->key_mtx);
 }

 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
 {
 	/*
 	 * When this count is zero, SKB resizing for allocating tailroom
 	 * for IV or MMIC is skipped. But, this check has created two race
 	 * cases in xmit path while transiting from zero count to one:
 	 *
 	 * 1. SKB resize was skipped because no key was added but just before
 	 * the xmit key is added and SW encryption kicks off.
 	 *
 	 * 2. SKB resize was skipped because all the keys were hw planted but
 	 * just before xmit one of the key is deleted and SW encryption kicks
 	 * off.
 	 *
 	 * In both the above case SW encryption will find not enough space for
 	 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
 	 *
 	 * Solution has been explained at
 	 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
 	 */

 	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
 		/*
 		 * Flush all XMIT packets currently using HW encryption or no
 		 * encryption at all if the count transition is from 0 -> 1.
 		 */
 		synchronize_net();
 	}
 }

 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 {
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
 	int ret;

 	might_sleep();

 	if (!key->local->ops->set_key)
 		goto out_unsupported;

 	assert_key_lock(key->local);

 	sta = key->sta;

 	/*
 	 * If this is a per-STA GTK, check if it
 	 * is supported; if not, return.
 	 */
 	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 	    !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
 		goto out_unsupported;

 	if (sta && !sta->uploaded)
 		goto out_unsupported;

 	sdata = key->sdata;
 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 		/*
 		 * The driver doesn't know anything about VLAN interfaces.
 		 * Hence, don't send GTKs for VLAN interfaces to the driver.
 		 */
 		if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 			goto out_unsupported;
 	}

 	ret = drv_set_key(key->local, SET_KEY, sdata,
 			  sta ? &sta->sta : NULL, &key->conf);

 	if (!ret) {
 		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;

 		if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 		      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
 		      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
 			sdata->crypto_tx_tailroom_needed_cnt--;

 		WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 			(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));

 		return 0;
 	}

 	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
 		sdata_err(sdata,
 			  "failed to set key (%d, %pM) to hardware (%d)\n",
 			  key->conf.keyidx,
 			  sta ? sta->sta.addr : bcast_addr, ret);

  out_unsupported:
 	switch (key->conf.cipher) {
 	case WLAN_CIPHER_SUITE_WEP40:
 	case WLAN_CIPHER_SUITE_WEP104:
 	case WLAN_CIPHER_SUITE_TKIP:
 	case WLAN_CIPHER_SUITE_CCMP:
 	case WLAN_CIPHER_SUITE_AES_CMAC:
 		/* all of these we can do in software */
 		return 0;
 	default:
 		return -EINVAL;
 	}
 }

 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 {
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
 	int ret;

 	might_sleep();

 	if (!key || !key->local->ops->set_key)
 		return;

 	assert_key_lock(key->local);

 	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 		return;

 	sta = key->sta;
 	sdata = key->sdata;

 	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 	      (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
 	      (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
 		increment_tailroom_need_count(sdata);

 	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 			  sta ? &sta->sta : NULL, &key->conf);

 	if (ret)
 		sdata_err(sdata,
 			  "failed to remove key (%d, %pM) from hardware (%d)\n",
 			  key->conf.keyidx,
 			  sta ? sta->sta.addr : bcast_addr, ret);

 	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 }

 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 					int idx, bool uni, bool multi)
 {
 	struct ieee80211_key *key = NULL;

 	assert_key_lock(sdata->local);

 	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

 	if (uni) {
 		rcu_assign_pointer(sdata->default_unicast_key, key);
 		drv_set_default_unicast_key(sdata->local, sdata, idx);
 	}

 	if (multi)
 		rcu_assign_pointer(sdata->default_multicast_key, key);

 	ieee80211_debugfs_key_update_default(sdata);
 }

 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 			       bool uni, bool multi)
 {
 	mutex_lock(&sdata->local->key_mtx);
 	__ieee80211_set_default_key(sdata, idx, uni, multi);
 	mutex_unlock(&sdata->local->key_mtx);
 }

 static void
 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 {
 	struct ieee80211_key *key = NULL;

 	assert_key_lock(sdata->local);

 	if (idx >= NUM_DEFAULT_KEYS &&
 	    idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 		key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

 	rcu_assign_pointer(sdata->default_mgmt_key, key);

 	ieee80211_debugfs_key_update_default(sdata);
 }

 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 				    int idx)
 {
 	mutex_lock(&sdata->local->key_mtx);
 	__ieee80211_set_default_mgmt_key(sdata, idx);
 	mutex_unlock(&sdata->local->key_mtx);
 }


 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 				    struct sta_info *sta,
 				    bool pairwise,
 				    struct ieee80211_key *old,
 				    struct ieee80211_key *new)
 {
 	int idx;
 	bool defunikey, defmultikey, defmgmtkey;

 	if (new)
 		list_add_tail(&new->list, &sdata->key_list);

 	if (sta && pairwise) {
 		rcu_assign_pointer(sta->ptk, new);
 	} else if (sta) {
 		if (old)
 			idx = old->conf.keyidx;
 		else
 			idx = new->conf.keyidx;
 		rcu_assign_pointer(sta->gtk[idx], new);
 	} else {
 		WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);

 		if (old)
 			idx = old->conf.keyidx;
 		else
 			idx = new->conf.keyidx;

 		defunikey = old &&
 			old == key_mtx_dereference(sdata->local,
 						sdata->default_unicast_key);
 		defmultikey = old &&
 			old == key_mtx_dereference(sdata->local,
 						sdata->default_multicast_key);
 		defmgmtkey = old &&
 			old == key_mtx_dereference(sdata->local,
 						sdata->default_mgmt_key);

 		if (defunikey && !new)
 			__ieee80211_set_default_key(sdata, -1, true, false);
 		if (defmultikey && !new)
 			__ieee80211_set_default_key(sdata, -1, false, true);
 		if (defmgmtkey && !new)
 			__ieee80211_set_default_mgmt_key(sdata, -1);

 		rcu_assign_pointer(sdata->keys[idx], new);
 		if (defunikey && new)
 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
 						    true, false);
 		if (defmultikey && new)
 			__ieee80211_set_default_key(sdata, new->conf.keyidx,
 						    false, true);
 		if (defmgmtkey && new)
 			__ieee80211_set_default_mgmt_key(sdata,
 							 new->conf.keyidx);
 	}

 	if (old)
 		list_del(&old->list);
 }

 struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 					  const u8 *key_data,
 					  size_t seq_len, const u8 *seq)
 {
 	struct ieee80211_key *key;
 	int i, j, err;

 	BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);

 	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 	if (!key)
 		return ERR_PTR(-ENOMEM);

 	/*
 	 * Default to software encryption; we'll later upload the
 	 * key to the hardware if possible.
 	 */
 	key->conf.flags = 0;
 	key->flags = 0;

 	key->conf.cipher = cipher;
 	key->conf.keyidx = idx;
 	key->conf.keylen = key_len;
 	switch (cipher) {
 	case WLAN_CIPHER_SUITE_WEP40:
 	case WLAN_CIPHER_SUITE_WEP104:
 		key->conf.iv_len = WEP_IV_LEN;
 		key->conf.icv_len = WEP_ICV_LEN;
 		break;
 	case WLAN_CIPHER_SUITE_TKIP:
 		key->conf.iv_len = TKIP_IV_LEN;
 		key->conf.icv_len = TKIP_ICV_LEN;
 		if (seq) {
 			for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 				key->u.tkip.rx[i].iv32 =
 					get_unaligned_le32(&seq[2]);
 				key->u.tkip.rx[i].iv16 =
 					get_unaligned_le16(seq);
 			}
 		}
 		spin_lock_init(&key->u.tkip.txlock);
 		break;
 	case WLAN_CIPHER_SUITE_CCMP:
 		key->conf.iv_len = CCMP_HDR_LEN;
 		key->conf.icv_len = CCMP_MIC_LEN;
 		if (seq) {
 			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 				for (j = 0; j < CCMP_PN_LEN; j++)
 					key->u.ccmp.rx_pn[i][j] =
 						seq[CCMP_PN_LEN - j - 1];
 		}
 		/*
 		 * Initialize AES key state here as an optimization so that
 		 * it does not need to be initialized for every packet.
 		 */
 		key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
 		if (IS_ERR(key->u.ccmp.tfm)) {
 			err = PTR_ERR(key->u.ccmp.tfm);
 			kfree(key);
 			return ERR_PTR(err);
 		}
 		break;
 	case WLAN_CIPHER_SUITE_AES_CMAC:
 		key->conf.iv_len = 0;
 		key->conf.icv_len = sizeof(struct ieee80211_mmie);
 		if (seq)
 			for (j = 0; j < CMAC_PN_LEN; j++)
 				key->u.aes_cmac.rx_pn[j] =
 					seq[CMAC_PN_LEN - j - 1];
 		/*
 		 * Initialize AES key state here as an optimization so that
 		 * it does not need to be initialized for every packet.
 		 */
 		key->u.aes_cmac.tfm =
 			ieee80211_aes_cmac_key_setup(key_data);
 		if (IS_ERR(key->u.aes_cmac.tfm)) {
 			err = PTR_ERR(key->u.aes_cmac.tfm);
 			kfree(key);
 			return ERR_PTR(err);
 		}
 		break;
 	}
 	memcpy(key->conf.key, key_data, key_len);
 	INIT_LIST_HEAD(&key->list);

 	return key;
 }

 static void __ieee80211_key_destroy(struct ieee80211_key *key)
 {
 	if (!key)
 		return;

 	/*
 	 * Synchronize so the TX path can no longer be using
 	 * this key before we free/remove it.
 	 */
 	synchronize_net();

 	if (key->local)
 		ieee80211_key_disable_hw_accel(key);

 	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
 		ieee80211_aes_key_free(key->u.ccmp.tfm);
 	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 		ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 	if (key->local) {
 		ieee80211_debugfs_key_remove(key);
 		key->sdata->crypto_tx_tailroom_needed_cnt--;
 	}

 	kfree(key);
 }

 int ieee80211_key_link(struct ieee80211_key *key,
 		       struct ieee80211_sub_if_data *sdata,
 		       struct sta_info *sta)
 {
 	struct ieee80211_key *old_key;
 	int idx, ret;
 	bool pairwise;

 	BUG_ON(!sdata);
 	BUG_ON(!key);

 	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 	idx = key->conf.keyidx;
 	key->local = sdata->local;
 	key->sdata = sdata;
 	key->sta = sta;

 	if (sta) {
 		/*
 		 * some hardware cannot handle TKIP with QoS, so
 		 * we indicate whether QoS could be in use.
 		 */
 		if (test_sta_flag(sta, WLAN_STA_WME))
 			key->conf.flags |= IEEE80211_KEY_FLAG_WMM_STA;
 	} else {
 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 			struct sta_info *ap;

 			/*
 			 * We're getting a sta pointer in, so must be under
 			 * appropriate locking for sta_info_get().
 			 */

 			/* same here, the AP could be using QoS */
 			ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
 			if (ap) {
 				if (test_sta_flag(ap, WLAN_STA_WME))
 					key->conf.flags |=
 						IEEE80211_KEY_FLAG_WMM_STA;
 			}
 		}
 	}

 	mutex_lock(&sdata->local->key_mtx);

 	if (sta && pairwise)
 		old_key = key_mtx_dereference(sdata->local, sta->ptk);
 	else if (sta)
 		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 	else
 		old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

 	increment_tailroom_need_count(sdata);

 	__ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 	__ieee80211_key_destroy(old_key);

 	ieee80211_debugfs_key_add(key);

 	ret = ieee80211_key_enable_hw_accel(key);

 	mutex_unlock(&sdata->local->key_mtx);

 	return ret;
 }

 void __ieee80211_key_free(struct ieee80211_key *key)
 {
 	if (!key)
 		return;

 	/*
 	 * Replace key with nothingness if it was ever used.
 	 */
 	if (key->sdata)
 		__ieee80211_key_replace(key->sdata, key->sta,
 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 				key, NULL);
 	__ieee80211_key_destroy(key);
 }

 void ieee80211_key_free(struct ieee80211_local *local,
 			struct ieee80211_key *key)
 {
 	mutex_lock(&local->key_mtx);
 	__ieee80211_key_free(key);
 	mutex_unlock(&local->key_mtx);
 }

 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_key *key;

 	ASSERT_RTNL();

 	if (WARN_ON(!ieee80211_sdata_running(sdata)))
 		return;

 	mutex_lock(&sdata->local->key_mtx);

 	sdata->crypto_tx_tailroom_needed_cnt = 0;

 	list_for_each_entry(key, &sdata->key_list, list) {
 		increment_tailroom_need_count(sdata);
 		ieee80211_key_enable_hw_accel(key);
 	}

 	mutex_unlock(&sdata->local->key_mtx);
 }

 void ieee80211_iter_keys(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_key *key;
 	struct ieee80211_sub_if_data *sdata;

 	ASSERT_RTNL();

 	mutex_lock(&local->key_mtx);
 	if (vif) {
 		sdata = vif_to_sdata(vif);
 		list_for_each_entry(key, &sdata->key_list, list)
 			iter(hw, &sdata->vif,
 			     key->sta ? &key->sta->sta : NULL,
 			     &key->conf, iter_data);
 	} else {
 		list_for_each_entry(sdata, &local->interfaces, list)
 			list_for_each_entry(key, &sdata->key_list, list)
 				iter(hw, &sdata->vif,
 				     key->sta ? &key->sta->sta : NULL,
 				     &key->conf, iter_data);
 	}
 	mutex_unlock(&local->key_mtx);
 }
 EXPORT_SYMBOL(ieee80211_iter_keys);

 void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_key *key;

 	ASSERT_RTNL();

 	mutex_lock(&sdata->local->key_mtx);

 	list_for_each_entry(key, &sdata->key_list, list)
 		ieee80211_key_disable_hw_accel(key);

 	mutex_unlock(&sdata->local->key_mtx);
 }

 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_key *key, *tmp;

 	mutex_lock(&sdata->local->key_mtx);

 	ieee80211_debugfs_key_remove_mgmt_default(sdata);

 	list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 		__ieee80211_key_free(key);

 	ieee80211_debugfs_key_update_default(sdata);

 	mutex_unlock(&sdata->local->key_mtx);
 }


 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 				const u8 *replay_ctr, gfp_t gfp)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

 	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);

 	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 }
 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);

 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
 			      struct ieee80211_key_seq *seq)
 {
 	struct ieee80211_key *key;
 	u64 pn64;

 	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
 		return;

 	key = container_of(keyconf, struct ieee80211_key, conf);

 	switch (key->conf.cipher) {
 	case WLAN_CIPHER_SUITE_TKIP:
 		seq->tkip.iv32 = key->u.tkip.tx.iv32;
 		seq->tkip.iv16 = key->u.tkip.tx.iv16;
 		break;
 	case WLAN_CIPHER_SUITE_CCMP:
 		pn64 = atomic64_read(&key->u.ccmp.tx_pn);
 		seq->ccmp.pn[5] = pn64;
 		seq->ccmp.pn[4] = pn64 >> 8;
 		seq->ccmp.pn[3] = pn64 >> 16;
 		seq->ccmp.pn[2] = pn64 >> 24;
 		seq->ccmp.pn[1] = pn64 >> 32;
 		seq->ccmp.pn[0] = pn64 >> 40;
 		break;
 	case WLAN_CIPHER_SUITE_AES_CMAC:
 		pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
 		seq->ccmp.pn[5] = pn64;
 		seq->ccmp.pn[4] = pn64 >> 8;
 		seq->ccmp.pn[3] = pn64 >> 16;
 		seq->ccmp.pn[2] = pn64 >> 24;
 		seq->ccmp.pn[1] = pn64 >> 32;
 		seq->ccmp.pn[0] = pn64 >> 40;
 		break;
 	default:
 		WARN_ON(1);
 	}
 }
 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);

 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 			      int tid, struct ieee80211_key_seq *seq)
 {
 	struct ieee80211_key *key;
 	const u8 *pn;

 	key = container_of(keyconf, struct ieee80211_key, conf);

 	switch (key->conf.cipher) {
 	case WLAN_CIPHER_SUITE_TKIP:
 		if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 			return;
 		seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 		seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 		break;
 	case WLAN_CIPHER_SUITE_CCMP:
 		if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 			return;
 		if (tid < 0)
 			pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 		else
 			pn = key->u.ccmp.rx_pn[tid];
 		memcpy(seq->ccmp.pn, pn, CCMP_PN_LEN);
 		break;
 	case WLAN_CIPHER_SUITE_AES_CMAC:
 		if (WARN_ON(tid != 0))
 			return;
 		pn = key->u.aes_cmac.rx_pn;
 		memcpy(seq->aes_cmac.pn, pn, CMAC_PN_LEN);
 		break;
 	}
 }
 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
	/*
	* Copyright 2002-2005, Instant802 Networks, Inc.
	* Copyright 2005-2006, Devicescape Software, Inc.
	* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
	* Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
	*
	* 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
	* published by the Free Software Foundation.
	*/

	#include <linux/if_ether.h>
	#include <linux/etherdevice.h>
	#include <linux/list.h>
	#include <linux/rcupdate.h>
	#include <linux/rtnetlink.h>
	#include <linux/slab.h>
	#include <linux/export.h>
	#include <net/mac80211.h>
	#include <asm/unaligned.h>
	#include "ieee80211_i.h"
	#include "driver-ops.h"
	#include "debugfs_key.h"
	#include "aes_ccm.h"
	#include "aes_cmac.h"


	/**
	* DOC: Key handling basics
	*
	* Key handling in mac80211 is done based on per-interface (sub_if_data)
	* keys and per-station keys. Since each station belongs to an interface,
	* each station key also belongs to that interface.
	*
	* Hardware acceleration is done on a best-effort basis for algorithms
	* that are implemented in software, for each key the hardware is asked
	* to enable that key for offloading but if it cannot do that the key is
	* simply kept for software encryption (unless it is for an algorithm
	* that isn't implemented in software).
	* There is currently no way of knowing whether a key is handled in SW
	* or HW except by looking into debugfs.
	*
	* All key management is internally protected by a mutex. Within all
	* other parts of mac80211, key references are, just as STA structure
	* references, protected by RCU. Note, however, that some things are
	* unprotected, namely the key->sta dereferences within the hardware
	* acceleration functions. This means that sta_info_destroy() must
	* remove the key which waits for an RCU grace period.
	*/

	static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

	static void assert_key_lock(struct ieee80211_local *local)
	{
	lockdep_assert_held(&local->key_mtx);
	}

	static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
	{
	/*
	* When this count is zero, SKB resizing for allocating tailroom
	* for IV or MMIC is skipped. But, this check has created two race
	* cases in xmit path while transiting from zero count to one:
	*
	* 1. SKB resize was skipped because no key was added but just before
	* the xmit key is added and SW encryption kicks off.
	*
	* 2. SKB resize was skipped because all the keys were hw planted but
	* just before xmit one of the key is deleted and SW encryption kicks
	* off.
	*
	* In both the above case SW encryption will find not enough space for
	* tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
	*
	* Solution has been explained at
	* http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
	*/

	if (!sdata->crypto_tx_tailroom_needed_cnt++) {
	/*
	* Flush all XMIT packets currently using HW encryption or no
	* encryption at all if the count transition is from 0 -> 1.
	*/
	synchronize_net();
	}
	}

	static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
	{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (!key->local->ops->set_key)
	goto out_unsupported;

	assert_key_lock(key->local);

	sta = key->sta;

	/*
	* If this is a per-STA GTK, check if it
	* is supported; if not, return.
	*/
	if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
	!(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
	goto out_unsupported;

	if (sta && !sta->uploaded)
	goto out_unsupported;

	sdata = key->sdata;
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
	/*
	* The driver doesn't know anything about VLAN interfaces.
	* Hence, don't send GTKs for VLAN interfaces to the driver.
	*/
	if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
	goto out_unsupported;
	}

	ret = drv_set_key(key->local, SET_KEY, sdata,
	sta ? &sta->sta : NULL, &key->conf);

	if (!ret) {
	key->flags \|= KEY_FLAG_UPLOADED_TO_HARDWARE;

	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) \|\|
	(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) \|\|
	(key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
	sdata->crypto_tx_tailroom_needed_cnt--;

	WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
	(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));

	return 0;
	}

	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
	sdata_err(sdata,
	"failed to set key (%d, %pM) to hardware (%d)\n",
	key->conf.keyidx,
	sta ? sta->sta.addr : bcast_addr, ret);

	out_unsupported:
	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
	case WLAN_CIPHER_SUITE_TKIP:
	case WLAN_CIPHER_SUITE_CCMP:
	case WLAN_CIPHER_SUITE_AES_CMAC:
	/* all of these we can do in software */
	return 0;
	default:
	return -EINVAL;
	}
	}

	static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
	{
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	int ret;

	might_sleep();

	if (!key \|\| !key->local->ops->set_key)
	return;

	assert_key_lock(key->local);

	if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
	return;

	sta = key->sta;
	sdata = key->sdata;

	if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) \|\|
	(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) \|\|
	(key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
	increment_tailroom_need_count(sdata);

	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
	sta ? &sta->sta : NULL, &key->conf);

	if (ret)
	sdata_err(sdata,
	"failed to remove key (%d, %pM) from hardware (%d)\n",
	key->conf.keyidx,
	sta ? sta->sta.addr : bcast_addr, ret);

	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
	}

	static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
	int idx, bool uni, bool multi)
	{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
	key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	if (uni) {
	rcu_assign_pointer(sdata->default_unicast_key, key);
	drv_set_default_unicast_key(sdata->local, sdata, idx);
	}

	if (multi)
	rcu_assign_pointer(sdata->default_multicast_key, key);

	ieee80211_debugfs_key_update_default(sdata);
	}

	void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
	bool uni, bool multi)
	{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_key(sdata, idx, uni, multi);
	mutex_unlock(&sdata->local->key_mtx);
	}

	static void
	__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
	{
	struct ieee80211_key *key = NULL;

	assert_key_lock(sdata->local);

	if (idx >= NUM_DEFAULT_KEYS &&
	idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
	key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	rcu_assign_pointer(sdata->default_mgmt_key, key);

	ieee80211_debugfs_key_update_default(sdata);
	}

	void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
	int idx)
	{
	mutex_lock(&sdata->local->key_mtx);
	__ieee80211_set_default_mgmt_key(sdata, idx);
	mutex_unlock(&sdata->local->key_mtx);
	}


	static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
	struct sta_info *sta,
	bool pairwise,
	struct ieee80211_key *old,
	struct ieee80211_key *new)
	{
	int idx;
	bool defunikey, defmultikey, defmgmtkey;

	if (new)
	list_add_tail(&new->list, &sdata->key_list);

	if (sta && pairwise) {
	rcu_assign_pointer(sta->ptk, new);
	} else if (sta) {
	if (old)
	idx = old->conf.keyidx;
	else
	idx = new->conf.keyidx;
	rcu_assign_pointer(sta->gtk[idx], new);
	} else {
	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);

	if (old)
	idx = old->conf.keyidx;
	else
	idx = new->conf.keyidx;

	defunikey = old &&
	old == key_mtx_dereference(sdata->local,
	sdata->default_unicast_key);
	defmultikey = old &&
	old == key_mtx_dereference(sdata->local,
	sdata->default_multicast_key);
	defmgmtkey = old &&
	old == key_mtx_dereference(sdata->local,
	sdata->default_mgmt_key);

	if (defunikey && !new)
	__ieee80211_set_default_key(sdata, -1, true, false);
	if (defmultikey && !new)
	__ieee80211_set_default_key(sdata, -1, false, true);
	if (defmgmtkey && !new)
	__ieee80211_set_default_mgmt_key(sdata, -1);

	rcu_assign_pointer(sdata->keys[idx], new);
	if (defunikey && new)
	__ieee80211_set_default_key(sdata, new->conf.keyidx,
	true, false);
	if (defmultikey && new)
	__ieee80211_set_default_key(sdata, new->conf.keyidx,
	false, true);
	if (defmgmtkey && new)
	__ieee80211_set_default_mgmt_key(sdata,
	new->conf.keyidx);
	}

	if (old)
	list_del(&old->list);
	}

	struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
	const u8 *key_data,
	size_t seq_len, const u8 *seq)
	{
	struct ieee80211_key *key;
	int i, j, err;

	BUG_ON(idx < 0 \|\| idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);

	key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
	if (!key)
	return ERR_PTR(-ENOMEM);

	/*
	* Default to software encryption; we'll later upload the
	* key to the hardware if possible.
	*/
	key->conf.flags = 0;
	key->flags = 0;

	key->conf.cipher = cipher;
	key->conf.keyidx = idx;
	key->conf.keylen = key_len;
	switch (cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
	key->conf.iv_len = WEP_IV_LEN;
	key->conf.icv_len = WEP_ICV_LEN;
	break;
	case WLAN_CIPHER_SUITE_TKIP:
	key->conf.iv_len = TKIP_IV_LEN;
	key->conf.icv_len = TKIP_ICV_LEN;
	if (seq) {
	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
	key->u.tkip.rx[i].iv32 =
	get_unaligned_le32(&seq[2]);
	key->u.tkip.rx[i].iv16 =
	get_unaligned_le16(seq);
	}
	}
	spin_lock_init(&key->u.tkip.txlock);
	break;
	case WLAN_CIPHER_SUITE_CCMP:
	key->conf.iv_len = CCMP_HDR_LEN;
	key->conf.icv_len = CCMP_MIC_LEN;
	if (seq) {
	for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
	for (j = 0; j < CCMP_PN_LEN; j++)
	key->u.ccmp.rx_pn[i][j] =
	seq[CCMP_PN_LEN - j - 1];
	}
	/*
	* Initialize AES key state here as an optimization so that
	* it does not need to be initialized for every packet.
	*/
	key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
	if (IS_ERR(key->u.ccmp.tfm)) {
	err = PTR_ERR(key->u.ccmp.tfm);
	kfree(key);
	return ERR_PTR(err);
	}
	break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
	key->conf.iv_len = 0;
	key->conf.icv_len = sizeof(struct ieee80211_mmie);
	if (seq)
	for (j = 0; j < CMAC_PN_LEN; j++)
	key->u.aes_cmac.rx_pn[j] =
	seq[CMAC_PN_LEN - j - 1];
	/*
	* Initialize AES key state here as an optimization so that
	* it does not need to be initialized for every packet.
	*/
	key->u.aes_cmac.tfm =
	ieee80211_aes_cmac_key_setup(key_data);
	if (IS_ERR(key->u.aes_cmac.tfm)) {
	err = PTR_ERR(key->u.aes_cmac.tfm);
	kfree(key);
	return ERR_PTR(err);
	}
	break;
	}
	memcpy(key->conf.key, key_data, key_len);
	INIT_LIST_HEAD(&key->list);

	return key;
	}

	static void __ieee80211_key_destroy(struct ieee80211_key *key)
	{
	if (!key)
	return;

	/*
	* Synchronize so the TX path can no longer be using
	* this key before we free/remove it.
	*/
	synchronize_net();

	if (key->local)
	ieee80211_key_disable_hw_accel(key);

	if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
	ieee80211_aes_key_free(key->u.ccmp.tfm);
	if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
	ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
	if (key->local) {
	ieee80211_debugfs_key_remove(key);
	key->sdata->crypto_tx_tailroom_needed_cnt--;
	}

	kfree(key);
	}

	int ieee80211_key_link(struct ieee80211_key *key,
	struct ieee80211_sub_if_data *sdata,
	struct sta_info *sta)
	{
	struct ieee80211_key *old_key;
	int idx, ret;
	bool pairwise;

	BUG_ON(!sdata);
	BUG_ON(!key);

	pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
	idx = key->conf.keyidx;
	key->local = sdata->local;
	key->sdata = sdata;
	key->sta = sta;

	if (sta) {
	/*
	* some hardware cannot handle TKIP with QoS, so
	* we indicate whether QoS could be in use.
	*/
	if (test_sta_flag(sta, WLAN_STA_WME))
	key->conf.flags \|= IEEE80211_KEY_FLAG_WMM_STA;
	} else {
	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
	struct sta_info *ap;

	/*
	* We're getting a sta pointer in, so must be under
	* appropriate locking for sta_info_get().
	*/

	/* same here, the AP could be using QoS */
	ap = sta_info_get(key->sdata, key->sdata->u.mgd.bssid);
	if (ap) {
	if (test_sta_flag(ap, WLAN_STA_WME))
	key->conf.flags \|=
	IEEE80211_KEY_FLAG_WMM_STA;
	}
	}
	}

	mutex_lock(&sdata->local->key_mtx);

	if (sta && pairwise)
	old_key = key_mtx_dereference(sdata->local, sta->ptk);
	else if (sta)
	old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
	else
	old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);

	increment_tailroom_need_count(sdata);

	__ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
	__ieee80211_key_destroy(old_key);

	ieee80211_debugfs_key_add(key);

	ret = ieee80211_key_enable_hw_accel(key);

	mutex_unlock(&sdata->local->key_mtx);

	return ret;
	}

	void __ieee80211_key_free(struct ieee80211_key *key)
	{
	if (!key)
	return;

	/*
	* Replace key with nothingness if it was ever used.
	*/
	if (key->sdata)
	__ieee80211_key_replace(key->sdata, key->sta,
	key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
	key, NULL);
	__ieee80211_key_destroy(key);
	}

	void ieee80211_key_free(struct ieee80211_local *local,
	struct ieee80211_key *key)
	{
	mutex_lock(&local->key_mtx);
	__ieee80211_key_free(key);
	mutex_unlock(&local->key_mtx);
	}

	void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
	{
	struct ieee80211_key *key;

	ASSERT_RTNL();

	if (WARN_ON(!ieee80211_sdata_running(sdata)))
	return;

	mutex_lock(&sdata->local->key_mtx);

	sdata->crypto_tx_tailroom_needed_cnt = 0;

	list_for_each_entry(key, &sdata->key_list, list) {
	increment_tailroom_need_count(sdata);
	ieee80211_key_enable_hw_accel(key);
	}

	mutex_unlock(&sdata->local->key_mtx);
	}

	void ieee80211_iter_keys(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_key *key;
	struct ieee80211_sub_if_data *sdata;

	ASSERT_RTNL();

	mutex_lock(&local->key_mtx);
	if (vif) {
	sdata = vif_to_sdata(vif);
	list_for_each_entry(key, &sdata->key_list, list)
	iter(hw, &sdata->vif,
	key->sta ? &key->sta->sta : NULL,
	&key->conf, iter_data);
	} else {
	list_for_each_entry(sdata, &local->interfaces, list)
	list_for_each_entry(key, &sdata->key_list, list)
	iter(hw, &sdata->vif,
	key->sta ? &key->sta->sta : NULL,
	&key->conf, iter_data);
	}
	mutex_unlock(&local->key_mtx);
	}
	EXPORT_SYMBOL(ieee80211_iter_keys);

	void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
	{
	struct ieee80211_key *key;

	ASSERT_RTNL();

	mutex_lock(&sdata->local->key_mtx);

	list_for_each_entry(key, &sdata->key_list, list)
	ieee80211_key_disable_hw_accel(key);

	mutex_unlock(&sdata->local->key_mtx);
	}

	void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
	{
	struct ieee80211_key key, tmp;

	mutex_lock(&sdata->local->key_mtx);

	ieee80211_debugfs_key_remove_mgmt_default(sdata);

	list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
	__ieee80211_key_free(key);

	ieee80211_debugfs_key_update_default(sdata);

	mutex_unlock(&sdata->local->key_mtx);
	}


	void ieee80211_gtk_rekey_notify(struct ieee80211_vif vif, const u8 bssid,
	const u8 *replay_ctr, gfp_t gfp)
	{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

	trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);

	cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
	}
	EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);

	void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
	struct ieee80211_key_seq *seq)
	{
	struct ieee80211_key *key;
	u64 pn64;

	if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
	return;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
	seq->tkip.iv32 = key->u.tkip.tx.iv32;
	seq->tkip.iv16 = key->u.tkip.tx.iv16;
	break;
	case WLAN_CIPHER_SUITE_CCMP:
	pn64 = atomic64_read(&key->u.ccmp.tx_pn);
	seq->ccmp.pn[5] = pn64;
	seq->ccmp.pn[4] = pn64 >> 8;
	seq->ccmp.pn[3] = pn64 >> 16;
	seq->ccmp.pn[2] = pn64 >> 24;
	seq->ccmp.pn[1] = pn64 >> 32;
	seq->ccmp.pn[0] = pn64 >> 40;
	break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
	pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
	seq->ccmp.pn[5] = pn64;
	seq->ccmp.pn[4] = pn64 >> 8;
	seq->ccmp.pn[3] = pn64 >> 16;
	seq->ccmp.pn[2] = pn64 >> 24;
	seq->ccmp.pn[1] = pn64 >> 32;
	seq->ccmp.pn[0] = pn64 >> 40;
	break;
	default:
	WARN_ON(1);
	}
	}
	EXPORT_SYMBOL(ieee80211_get_key_tx_seq);

	void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
	int tid, struct ieee80211_key_seq *seq)
	{
	struct ieee80211_key *key;
	const u8 *pn;

	key = container_of(keyconf, struct ieee80211_key, conf);

	switch (key->conf.cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
	if (WARN_ON(tid < 0 \|\| tid >= IEEE80211_NUM_TIDS))
	return;
	seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
	seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
	break;
	case WLAN_CIPHER_SUITE_CCMP:
	if (WARN_ON(tid < -1 \|\| tid >= IEEE80211_NUM_TIDS))
	return;
	if (tid < 0)
	pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
	else
	pn = key->u.ccmp.rx_pn[tid];
	memcpy(seq->ccmp.pn, pn, CCMP_PN_LEN);
	break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
	if (WARN_ON(tid != 0))
	return;
	pn = key->u.aes_cmac.rx_pn;
	memcpy(seq->aes_cmac.pn, pn, CMAC_PN_LEN);
	break;
	}
	}
	EXPORT_SYMBOL(ieee80211_get_key_rx_seq);