* 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"
-struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
- int idx, size_t key_len, gfp_t flags)
+
+/**
+ * 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 each key
+ * that is eligible the hardware is asked to enable that key but if
+ * it cannot do that they key is simply kept for software encryption.
+ * There is currently no way of knowing this except by looking into
+ * debugfs.
+ *
+ * All key operations are protected internally so you can call them at
+ * any time.
+ *
+ * Within 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 flush the key todo
+ * list.
+ *
+ * All the direct key list manipulation functions must not sleep because
+ * they can operate on STA info structs that are protected by RCU.
+ */
+
+static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
+
+/* key mutex: used to synchronise todo runners */
+static DEFINE_MUTEX(key_mutex);
+static DEFINE_SPINLOCK(todo_lock);
+static LIST_HEAD(todo_list);
+
+static void key_todo(struct work_struct *work)
+{
+ ieee80211_key_todo();
+}
+
+static DECLARE_WORK(todo_work, key_todo);
+
+/**
+ * add_todo - add todo item for a key
+ *
+ * @key: key to add to do item for
+ * @flag: todo flag(s)
+ *
+ * Must be called with IRQs or softirqs disabled.
+ */
+static void add_todo(struct ieee80211_key *key, u32 flag)
+{
+ if (!key)
+ return;
+
+ spin_lock(&todo_lock);
+ key->flags |= flag;
+ /*
+ * Remove again if already on the list so that we move it to the end.
+ */
+ if (!list_empty(&key->todo))
+ list_del(&key->todo);
+ list_add_tail(&key->todo, &todo_list);
+ schedule_work(&todo_work);
+ spin_unlock(&todo_lock);
+}
+
+/**
+ * ieee80211_key_lock - lock the mac80211 key operation lock
+ *
+ * This locks the (global) mac80211 key operation lock, all
+ * key operations must be done under this lock.
+ */
+static void ieee80211_key_lock(void)
+{
+ mutex_lock(&key_mutex);
+}
+
+/**
+ * ieee80211_key_unlock - unlock the mac80211 key operation lock
+ */
+static void ieee80211_key_unlock(void)
+{
+ mutex_unlock(&key_mutex);
+}
+
+static void assert_key_lock(void)
+{
+ WARN_ON(!mutex_is_locked(&key_mutex));
+}
+
+static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key)
+{
+ if (key->sta)
+ return &key->sta->sta;
+
+ return NULL;
+}
+
+static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_sta *sta;
+ int ret;
+
+ assert_key_lock();
+ might_sleep();
+
+ if (!key->local->ops->set_key)
+ 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, SET_KEY, sdata, sta, &key->conf);
+
+ if (!ret) {
+ spin_lock_bh(&todo_lock);
+ key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
+ spin_unlock_bh(&todo_lock);
+ }
+
+ if (ret && ret != -ENOSPC && ret != -EOPNOTSUPP)
+ printk(KERN_ERR "mac80211-%s: failed to set key "
+ "(%d, %pM) to hardware (%d)\n",
+ wiphy_name(key->local->hw.wiphy),
+ key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
+}
+
+static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_sta *sta;
+ int ret;
+
+ assert_key_lock();
+ might_sleep();
+
+ if (!key || !key->local->ops->set_key)
+ return;
+
+ spin_lock_bh(&todo_lock);
+ if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
+ spin_unlock_bh(&todo_lock);
+ return;
+ }
+ spin_unlock_bh(&todo_lock);
+
+ 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)
+ printk(KERN_ERR "mac80211-%s: failed to remove key "
+ "(%d, %pM) from hardware (%d)\n",
+ wiphy_name(key->local->hw.wiphy),
+ key->conf.keyidx, sta ? sta->addr : bcast_addr, ret);
+
+ spin_lock_bh(&todo_lock);
+ key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
+ spin_unlock_bh(&todo_lock);
+}
+
+static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
+ int idx)
+{
+ struct ieee80211_key *key = NULL;
+
+ if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
+ key = sdata->keys[idx];
+
+ rcu_assign_pointer(sdata->default_key, key);
+
+ if (key)
+ add_todo(key, KEY_FLAG_TODO_DEFKEY);
+}
+
+void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sdata->local->key_lock, flags);
+ __ieee80211_set_default_key(sdata, idx);
+ spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+}
+
+static void
+__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ struct ieee80211_key *key = NULL;
+
+ if (idx >= NUM_DEFAULT_KEYS &&
+ idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+ key = sdata->keys[idx];
+
+ rcu_assign_pointer(sdata->default_mgmt_key, key);
+
+ if (key)
+ add_todo(key, KEY_FLAG_TODO_DEFMGMTKEY);
+}
+
+void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
+ int idx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sdata->local->key_lock, flags);
+ __ieee80211_set_default_mgmt_key(sdata, idx);
+ spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+}
+
+
+static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
+ struct sta_info *sta,
+ struct ieee80211_key *old,
+ struct ieee80211_key *new)
+{
+ int idx, defkey, defmgmtkey;
+
+ if (new)
+ list_add(&new->list, &sdata->key_list);
+
+ if (sta) {
+ rcu_assign_pointer(sta->key, new);
+ } else {
+ WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
+
+ if (old)
+ idx = old->conf.keyidx;
+ else
+ idx = new->conf.keyidx;
+
+ defkey = old && sdata->default_key == old;
+ defmgmtkey = old && sdata->default_mgmt_key == old;
+
+ if (defkey && !new)
+ __ieee80211_set_default_key(sdata, -1);
+ if (defmgmtkey && !new)
+ __ieee80211_set_default_mgmt_key(sdata, -1);
+
+ rcu_assign_pointer(sdata->keys[idx], new);
+ if (defkey && new)
+ __ieee80211_set_default_key(sdata, new->conf.keyidx);
+ if (defmgmtkey && new)
+ __ieee80211_set_default_mgmt_key(sdata,
+ new->conf.keyidx);
+ }
+
+ if (old) {
+ /*
+ * We'll use an empty list to indicate that the key
+ * has already been removed.
+ */
+ list_del_init(&old->list);
+ }
+}
+
+struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
+ int idx,
+ size_t key_len,
+ const u8 *key_data,
+ size_t seq_len, const u8 *seq)
{
struct ieee80211_key *key;
+ int i, j;
- key = kzalloc(sizeof(struct ieee80211_key) + key_len, flags);
+ 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 NULL;
- kref_init(&key->kref);
+
+ /*
+ * Default to software encryption; we'll later upload the
+ * key to the hardware if possible.
+ */
+ key->conf.flags = 0;
+ key->flags = 0;
+
+ key->conf.alg = alg;
+ key->conf.keyidx = idx;
+ key->conf.keylen = key_len;
+ switch (alg) {
+ case ALG_WEP:
+ key->conf.iv_len = WEP_IV_LEN;
+ key->conf.icv_len = WEP_ICV_LEN;
+ break;
+ case ALG_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 ALG_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; i++)
+ for (j = 0; j < CCMP_PN_LEN; j++)
+ key->u.ccmp.rx_pn[i][j] =
+ seq[CCMP_PN_LEN - j - 1];
+ }
+ break;
+ case ALG_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];
+ break;
+ }
+ memcpy(key->conf.key, key_data, key_len);
+ INIT_LIST_HEAD(&key->list);
+ INIT_LIST_HEAD(&key->todo);
+
+ if (alg == ALG_CCMP) {
+ /*
+ * 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 (!key->u.ccmp.tfm) {
+ kfree(key);
+ return NULL;
+ }
+ }
+
+ if (alg == ALG_AES_CMAC) {
+ /*
+ * 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 (!key->u.aes_cmac.tfm) {
+ kfree(key);
+ return NULL;
+ }
+ }
+
return key;
}
-static void ieee80211_key_release(struct kref *kref)
+void ieee80211_key_link(struct ieee80211_key *key,
+ struct ieee80211_sub_if_data *sdata,
+ struct sta_info *sta)
+{
+ struct ieee80211_key *old_key;
+ unsigned long flags;
+ int idx;
+
+ BUG_ON(!sdata);
+ BUG_ON(!key);
+
+ 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;
+
+ /*
+ * This key is for a specific sta interface,
+ * inform the driver that it should try to store
+ * this key as pairwise key.
+ */
+ key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
+ } else {
+ if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ struct sta_info *ap;
+
+ /*
+ * We're getting a sta pointer in,
+ * so must be under RCU read lock.
+ */
+
+ /* 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;
+ }
+ }
+ }
+
+ spin_lock_irqsave(&sdata->local->key_lock, flags);
+
+ if (sta)
+ old_key = sta->key;
+ else
+ old_key = sdata->keys[idx];
+
+ __ieee80211_key_replace(sdata, sta, old_key, key);
+
+ /* free old key later */
+ add_todo(old_key, KEY_FLAG_TODO_DELETE);
+
+ add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS);
+ if (ieee80211_sdata_running(sdata))
+ add_todo(key, KEY_FLAG_TODO_HWACCEL_ADD);
+
+ spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+}
+
+static void __ieee80211_key_free(struct ieee80211_key *key)
+{
+ /*
+ * Replace key with nothingness if it was ever used.
+ */
+ if (key->sdata)
+ __ieee80211_key_replace(key->sdata, key->sta,
+ key, NULL);
+
+ add_todo(key, KEY_FLAG_TODO_DELETE);
+}
+
+void ieee80211_key_free(struct ieee80211_key *key)
+{
+ unsigned long flags;
+
+ if (!key)
+ return;
+
+ if (!key->sdata) {
+ /* The key has not been linked yet, simply free it
+ * and don't Oops */
+ if (key->conf.alg == ALG_CCMP)
+ ieee80211_aes_key_free(key->u.ccmp.tfm);
+ kfree(key);
+ return;
+ }
+
+ spin_lock_irqsave(&key->sdata->local->key_lock, flags);
+ __ieee80211_key_free(key);
+ spin_unlock_irqrestore(&key->sdata->local->key_lock, flags);
+}
+
+/*
+ * To be safe against concurrent manipulations of the list (which shouldn't
+ * actually happen) we need to hold the spinlock. But under the spinlock we
+ * can't actually do much, so we defer processing to the todo list. Then run
+ * the todo list to be sure the operation and possibly previously pending
+ * operations are completed.
+ */
+static void ieee80211_todo_for_each_key(struct ieee80211_sub_if_data *sdata,
+ u32 todo_flags)
{
struct ieee80211_key *key;
+ unsigned long flags;
+
+ might_sleep();
+
+ spin_lock_irqsave(&sdata->local->key_lock, flags);
+ list_for_each_entry(key, &sdata->key_list, list)
+ add_todo(key, todo_flags);
+ spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+
+ ieee80211_key_todo();
+}
+
+void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
+{
+ ASSERT_RTNL();
+
+ if (WARN_ON(!ieee80211_sdata_running(sdata)))
+ return;
+
+ ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_ADD);
+}
+
+void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata)
+{
+ ASSERT_RTNL();
+
+ ieee80211_todo_for_each_key(sdata, KEY_FLAG_TODO_HWACCEL_REMOVE);
+}
+
+static void __ieee80211_key_destroy(struct ieee80211_key *key)
+{
+ if (!key)
+ return;
+
+ ieee80211_key_disable_hw_accel(key);
- key = container_of(kref, struct ieee80211_key, kref);
if (key->conf.alg == ALG_CCMP)
ieee80211_aes_key_free(key->u.ccmp.tfm);
+ if (key->conf.alg == ALG_AES_CMAC)
+ ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
ieee80211_debugfs_key_remove(key);
+
kfree(key);
}
-void ieee80211_key_free(struct ieee80211_key *key)
+static void __ieee80211_key_todo(void)
{
- if (key)
- kref_put(&key->kref, ieee80211_key_release);
+ struct ieee80211_key *key;
+ bool work_done;
+ u32 todoflags;
+
+ /*
+ * NB: sta_info_destroy relies on this!
+ */
+ synchronize_rcu();
+
+ spin_lock_bh(&todo_lock);
+ while (!list_empty(&todo_list)) {
+ key = list_first_entry(&todo_list, struct ieee80211_key, todo);
+ list_del_init(&key->todo);
+ todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS |
+ KEY_FLAG_TODO_DEFKEY |
+ KEY_FLAG_TODO_DEFMGMTKEY |
+ KEY_FLAG_TODO_HWACCEL_ADD |
+ KEY_FLAG_TODO_HWACCEL_REMOVE |
+ KEY_FLAG_TODO_DELETE);
+ key->flags &= ~todoflags;
+ spin_unlock_bh(&todo_lock);
+
+ work_done = false;
+
+ if (todoflags & KEY_FLAG_TODO_ADD_DEBUGFS) {
+ ieee80211_debugfs_key_add(key);
+ work_done = true;
+ }
+ if (todoflags & KEY_FLAG_TODO_DEFKEY) {
+ ieee80211_debugfs_key_remove_default(key->sdata);
+ ieee80211_debugfs_key_add_default(key->sdata);
+ work_done = true;
+ }
+ if (todoflags & KEY_FLAG_TODO_DEFMGMTKEY) {
+ ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
+ ieee80211_debugfs_key_add_mgmt_default(key->sdata);
+ work_done = true;
+ }
+ if (todoflags & KEY_FLAG_TODO_HWACCEL_ADD) {
+ ieee80211_key_enable_hw_accel(key);
+ work_done = true;
+ }
+ if (todoflags & KEY_FLAG_TODO_HWACCEL_REMOVE) {
+ ieee80211_key_disable_hw_accel(key);
+ work_done = true;
+ }
+ if (todoflags & KEY_FLAG_TODO_DELETE) {
+ __ieee80211_key_destroy(key);
+ work_done = true;
+ }
+
+ WARN_ON(!work_done);
+
+ spin_lock_bh(&todo_lock);
+ }
+ spin_unlock_bh(&todo_lock);
+}
+
+void ieee80211_key_todo(void)
+{
+ ieee80211_key_lock();
+ __ieee80211_key_todo();
+ ieee80211_key_unlock();
+}
+
+void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_key *key, *tmp;
+ unsigned long flags;
+
+ ieee80211_key_lock();
+
+ ieee80211_debugfs_key_remove_default(sdata);
+ ieee80211_debugfs_key_remove_mgmt_default(sdata);
+
+ spin_lock_irqsave(&sdata->local->key_lock, flags);
+ list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
+ __ieee80211_key_free(key);
+ spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+
+ __ieee80211_key_todo();
+
+ ieee80211_key_unlock();
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff