diff options
author | Johannes Berg <johannes.berg@intel.com> | 2010-06-01 08:19:19 (GMT) |
---|---|---|
committer | John W. Linville <linville@tuxdriver.com> | 2010-06-03 18:10:46 (GMT) |
commit | ad0e2b5a00dbec303e4682b403bb6703d11dcdb2 (patch) | |
tree | b7aeb06a284af0cfb4aa1de840592478b373f554 /net/mac80211/key.c | |
parent | efe4c457a1d4e56840c42bf2e409dc04e8ad4304 (diff) | |
download | linux-ad0e2b5a00dbec303e4682b403bb6703d11dcdb2.tar.xz |
mac80211: simplify key locking
Since I recently made station management able
to sleep, I can now rework key management as
well; since it will no longer need a spinlock
and can also use a mutex instead, a bunch of
code to allow drivers' set_key to sleep while
key management is protected by a spinlock can
now be removed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/key.c')
-rw-r--r-- | net/mac80211/key.c | 288 |
1 files changed, 66 insertions, 222 deletions
diff --git a/net/mac80211/key.c b/net/mac80211/key.c index e8f6e3b..d0d9001 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -36,80 +36,20 @@ * 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. + * All key operations are protected internally. * * 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. + * 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 }; -/* 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) +static void assert_key_lock(struct ieee80211_local *local) { - 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)); + WARN_ON(!mutex_is_locked(&local->key_mtx)); } static struct ieee80211_sta *get_sta_for_key(struct ieee80211_key *key) @@ -126,12 +66,13 @@ static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key) struct ieee80211_sta *sta; int ret; - assert_key_lock(); might_sleep(); if (!key->local->ops->set_key) return; + assert_key_lock(key->local); + sta = get_sta_for_key(key); sdata = key->sdata; @@ -142,11 +83,8 @@ static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key) ret = drv_set_key(key->local, SET_KEY, sdata, sta, &key->conf); - if (!ret) { - spin_lock_bh(&todo_lock); + if (!ret) 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 " @@ -161,18 +99,15 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) 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); + assert_key_lock(key->local); + + if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) return; - } - spin_unlock_bh(&todo_lock); sta = get_sta_for_key(key); sdata = key->sdata; @@ -191,9 +126,7 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) 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, @@ -201,22 +134,24 @@ static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, { struct ieee80211_key *key = NULL; + assert_key_lock(sdata->local); + 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); + if (key) { + ieee80211_debugfs_key_remove_default(key->sdata); + ieee80211_debugfs_key_add_default(key->sdata); + } } void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx) { - unsigned long flags; - - spin_lock_irqsave(&sdata->local->key_lock, flags); + mutex_lock(&sdata->local->key_mtx); __ieee80211_set_default_key(sdata, idx); - spin_unlock_irqrestore(&sdata->local->key_lock, flags); + mutex_unlock(&sdata->local->key_mtx); } static void @@ -224,24 +159,26 @@ __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 = sdata->keys[idx]; rcu_assign_pointer(sdata->default_mgmt_key, key); - if (key) - add_todo(key, KEY_FLAG_TODO_DEFMGMTKEY); + if (key) { + ieee80211_debugfs_key_remove_mgmt_default(key->sdata); + ieee80211_debugfs_key_add_mgmt_default(key->sdata); + } } 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); + mutex_lock(&sdata->local->key_mtx); __ieee80211_set_default_mgmt_key(sdata, idx); - spin_unlock_irqrestore(&sdata->local->key_lock, flags); + mutex_unlock(&sdata->local->key_mtx); } @@ -352,7 +289,6 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg, } memcpy(key->conf.key, key_data, key_len); INIT_LIST_HEAD(&key->list); - INIT_LIST_HEAD(&key->todo); if (alg == ALG_CCMP) { /* @@ -382,12 +318,27 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg, return key; } +static void __ieee80211_key_destroy(struct ieee80211_key *key) +{ + if (!key) + return; + + ieee80211_key_disable_hw_accel(key); + + 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_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); @@ -431,7 +382,7 @@ void ieee80211_key_link(struct ieee80211_key *key, } } - spin_lock_irqsave(&sdata->local->key_lock, flags); + mutex_lock(&sdata->local->key_mtx); if (sta) old_key = sta->key; @@ -439,15 +390,13 @@ void ieee80211_key_link(struct ieee80211_key *key, old_key = sdata->keys[idx]; __ieee80211_key_replace(sdata, sta, old_key, key); + __ieee80211_key_destroy(old_key); - /* free old key later */ - add_todo(old_key, KEY_FLAG_TODO_DELETE); + ieee80211_debugfs_key_add(key); - add_todo(key, KEY_FLAG_TODO_ADD_DEBUGFS); - if (ieee80211_sdata_running(sdata)) - add_todo(key, KEY_FLAG_TODO_HWACCEL_ADD); + ieee80211_key_enable_hw_accel(key); - spin_unlock_irqrestore(&sdata->local->key_lock, flags); + mutex_unlock(&sdata->local->key_mtx); } static void __ieee80211_key_free(struct ieee80211_key *key) @@ -458,170 +407,65 @@ static void __ieee80211_key_free(struct ieee80211_key *key) if (key->sdata) __ieee80211_key_replace(key->sdata, key->sta, key, NULL); - - add_todo(key, KEY_FLAG_TODO_DELETE); + __ieee80211_key_destroy(key); } void ieee80211_key_free(struct ieee80211_key *key) { - unsigned long flags; + struct ieee80211_local *local; 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; - } + local = key->sdata->local; - spin_lock_irqsave(&key->sdata->local->key_lock, flags); + mutex_lock(&local->key_mtx); __ieee80211_key_free(key); - spin_unlock_irqrestore(&key->sdata->local->key_lock, flags); + mutex_unlock(&local->key_mtx); } -/* - * 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) +void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata) { 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); + mutex_lock(&sdata->local->key_mtx); - 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); + list_for_each_entry(key, &sdata->key_list, list) + ieee80211_key_enable_hw_accel(key); - kfree(key); + mutex_unlock(&sdata->local->key_mtx); } -static void __ieee80211_key_todo(void) +void ieee80211_disable_keys(struct ieee80211_sub_if_data *sdata) { 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; - } + ASSERT_RTNL(); - WARN_ON(!work_done); + mutex_lock(&sdata->local->key_mtx); - spin_lock_bh(&todo_lock); - } - spin_unlock_bh(&todo_lock); -} + list_for_each_entry(key, &sdata->key_list, list) + ieee80211_key_disable_hw_accel(key); -void ieee80211_key_todo(void) -{ - ieee80211_key_lock(); - __ieee80211_key_todo(); - ieee80211_key_unlock(); + mutex_unlock(&sdata->local->key_mtx); } void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata) { struct ieee80211_key *key, *tmp; - unsigned long flags; - ieee80211_key_lock(); + mutex_lock(&sdata->local->key_mtx); 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(); + mutex_unlock(&sdata->local->key_mtx); } |