1 files changed, 535 insertions, 0 deletions

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
new file mode 100644
index 00000000..f825e2f0
--- /dev/null
+++ b/net/mac80211/key.c
@@ -0,0 +1,535 @@
+/*
+ * 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 <net/mac80211.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 struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
+{
+	if (key->sta)
+		return &key->sta->sta;
+
+	return NULL;
+}
+
+static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_sta *sta;
+	int ret;
+
+	might_sleep();
+
+	if (!key->local->ops->set_key)
+		goto out_unsupported;
+
+	assert_key_lock(key->local);
+
+	sta = get_sta_for_key(key);
+
+	/*
+	 * 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;
+
+	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;
+		sdata = container_of(sdata->bss,
+				     struct ieee80211_sub_if_data,
+				     u.ap);
+	}
+
+	ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf);
+
+	if (!ret) {
+		key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
+		return 0;
+	}
+
+	if (ret != -ENOSPC && ret != -EOPNOTSUPP)
+		wiphy_err(key->local->hw.wiphy,
+			  "failed to set key (%d, %pM) to hardware (%d)\n",
+			  key->conf.keyidx, 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 ieee80211_sta *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 = get_sta_for_key(key);
+	sdata = key->sdata;
+
+	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+		sdata = container_of(sdata->bss,
+				     struct ieee80211_sub_if_data,
+				     u.ap);
+
+	ret = drv_set_key(key->local, DISABLE_KEY, sdata,
+			  sta, &key->conf);
+
+	if (ret)
+		wiphy_err(key->local->hw.wiphy,
+			  "failed to remove key (%d, %pM) from hardware (%d)\n",
+			  key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
+
+	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
+}
+
+void ieee80211_key_removed(struct ieee80211_key_conf *key_conf)
+{
+	struct ieee80211_key *key;
+
+	key = container_of(key_conf, struct ieee80211_key, conf);
+
+	might_sleep();
+	assert_key_lock(key->local);
+
+	key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
+
+	/*
+	 * Flush TX path to avoid attempts to use this key
+	 * after this function returns. Until then, drivers
+	 * must be prepared to handle the key.
+	 */
+	synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(ieee80211_key_removed);
+
+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);
+	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(&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 < NUM_RX_DATA_QUEUES; i++) {
+				key->u.tkip.rx[i].iv32 =
+					get_unaligned_le32(&seq[2]);
+				key->u.tkip.rx[i].iv16 =
+					get_unaligned_le16(seq);
+			}
+		}
+		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 < NUM_RX_DATA_QUEUES + 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 < 6; j++)
+				key->u.aes_cmac.rx_pn[j] = seq[6 - 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_rcu();
+
+	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);
+
+	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_flags(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_flags(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]);
+
+	__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);
+
+	list_for_each_entry(key, &sdata->key_list, list)
+		ieee80211_key_enable_hw_accel(key);
+
+	mutex_unlock(&sdata->local->key_mtx);
+}
+
+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);
+}