diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
commit | cf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch) | |
tree | 1b7705db288ae2917105e624b01fdf81e0882bf1 /net/mac80211/sta_info.c | |
parent | adf6d34e460387ee3e8f1e1875d52bff51212c7d (diff) | |
parent | 15f7d677ccff6f0f5de8a1ee43a792567e9f9de9 (diff) | |
download | linux-fsl-qoriq-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.tar.xz |
Merge branch 'merge-fixes' into devel
Diffstat (limited to 'net/mac80211/sta_info.c')
-rw-r--r-- | net/mac80211/sta_info.c | 698 |
1 files changed, 523 insertions, 175 deletions
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 1f74bd2..7d4fe4a 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -15,21 +15,57 @@ #include <linux/skbuff.h> #include <linux/if_arp.h> #include <linux/timer.h> +#include <linux/rtnetlink.h> #include <net/mac80211.h> #include "ieee80211_i.h" -#include "ieee80211_rate.h" +#include "rate.h" #include "sta_info.h" #include "debugfs_sta.h" +#include "mesh.h" -/* Caller must hold local->sta_lock */ -static void sta_info_hash_add(struct ieee80211_local *local, - struct sta_info *sta) -{ - sta->hnext = local->sta_hash[STA_HASH(sta->addr)]; - local->sta_hash[STA_HASH(sta->addr)] = sta; -} - +/** + * DOC: STA information lifetime rules + * + * STA info structures (&struct sta_info) are managed in a hash table + * for faster lookup and a list for iteration. They are managed using + * RCU, i.e. access to the list and hash table is protected by RCU. + * + * Upon allocating a STA info structure with sta_info_alloc(), the caller owns + * that structure. It must then either destroy it using sta_info_destroy() + * (which is pretty useless) or insert it into the hash table using + * sta_info_insert() which demotes the reference from ownership to a regular + * RCU-protected reference; if the function is called without protection by an + * RCU critical section the reference is instantly invalidated. Note that the + * caller may not do much with the STA info before inserting it, in particular, + * it may not start any mesh peer link management or add encryption keys. + * + * When the insertion fails (sta_info_insert()) returns non-zero), the + * structure will have been freed by sta_info_insert()! + * + * Because there are debugfs entries for each station, and adding those + * must be able to sleep, it is also possible to "pin" a station entry, + * that means it can be removed from the hash table but not be freed. + * See the comment in __sta_info_unlink() for more information, this is + * an internal capability only. + * + * In order to remove a STA info structure, the caller needs to first + * unlink it (sta_info_unlink()) from the list and hash tables and + * then destroy it; sta_info_destroy() will wait for an RCU grace period + * to elapse before actually freeing it. Due to the pinning and the + * possibility of multiple callers trying to remove the same STA info at + * the same time, sta_info_unlink() can clear the STA info pointer it is + * passed to indicate that the STA info is owned by somebody else now. + * + * If sta_info_unlink() did not clear the pointer then the caller owns + * the STA info structure now and is responsible of destroying it with + * a call to sta_info_destroy(). + * + * In all other cases, there is no concept of ownership on a STA entry, + * each structure is owned by the global hash table/list until it is + * removed. All users of the structure need to be RCU protected so that + * the structure won't be freed before they are done using it. + */ /* Caller must hold local->sta_lock */ static int sta_info_hash_del(struct ieee80211_local *local, @@ -41,237 +77,439 @@ static int sta_info_hash_del(struct ieee80211_local *local, if (!s) return -ENOENT; if (s == sta) { - local->sta_hash[STA_HASH(sta->addr)] = s->hnext; + rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], + s->hnext); return 0; } while (s->hnext && s->hnext != sta) s = s->hnext; if (s->hnext) { - s->hnext = sta->hnext; + rcu_assign_pointer(s->hnext, sta->hnext); return 0; } return -ENOENT; } -struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr) +/* protected by RCU */ +static struct sta_info *__sta_info_find(struct ieee80211_local *local, + u8 *addr) { struct sta_info *sta; - read_lock_bh(&local->sta_lock); - sta = local->sta_hash[STA_HASH(addr)]; + sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]); while (sta) { - if (memcmp(sta->addr, addr, ETH_ALEN) == 0) { - __sta_info_get(sta); + if (compare_ether_addr(sta->addr, addr) == 0) break; - } - sta = sta->hnext; + sta = rcu_dereference(sta->hnext); } - read_unlock_bh(&local->sta_lock); - return sta; } + +struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr) +{ + return __sta_info_find(local, addr); +} EXPORT_SYMBOL(sta_info_get); -int sta_info_min_txrate_get(struct ieee80211_local *local) +struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx, + struct net_device *dev) { struct sta_info *sta; - struct ieee80211_hw_mode *mode; - int min_txrate = 9999999; - int i; - - read_lock_bh(&local->sta_lock); - mode = local->oper_hw_mode; - for (i = 0; i < STA_HASH_SIZE; i++) { - sta = local->sta_hash[i]; - while (sta) { - if (sta->txrate < min_txrate) - min_txrate = sta->txrate; - sta = sta->hnext; + int i = 0; + + list_for_each_entry_rcu(sta, &local->sta_list, list) { + if (dev && dev != sta->sdata->dev) + continue; + if (i < idx) { + ++i; + continue; } + return sta; } - read_unlock_bh(&local->sta_lock); - if (min_txrate == 9999999) - min_txrate = 0; - return mode->rates[min_txrate].rate; + return NULL; } +/** + * __sta_info_free - internal STA free helper + * + * @sta: STA info to free + * + * This function must undo everything done by sta_info_alloc() + * that may happen before sta_info_insert(). + */ +static void __sta_info_free(struct ieee80211_local *local, + struct sta_info *sta) +{ + DECLARE_MAC_BUF(mbuf); + + rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv); + rate_control_put(sta->rate_ctrl); + +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + printk(KERN_DEBUG "%s: Destroyed STA %s\n", + wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr)); +#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ -static void sta_info_release(struct kref *kref) + kfree(sta); +} + +void sta_info_destroy(struct sta_info *sta) { - struct sta_info *sta = container_of(kref, struct sta_info, kref); - struct ieee80211_local *local = sta->local; + struct ieee80211_local *local; struct sk_buff *skb; int i; - /* free sta structure; it has already been removed from - * hash table etc. external structures. Make sure that all - * buffered frames are release (one might have been added - * after sta_info_free() was called). */ + might_sleep(); + + if (!sta) + return; + + local = sta->local; + + rate_control_remove_sta_debugfs(sta); + ieee80211_sta_debugfs_remove(sta); + +#ifdef CONFIG_MAC80211_MESH + if (ieee80211_vif_is_mesh(&sta->sdata->vif)) + mesh_plink_deactivate(sta); +#endif + + /* + * We have only unlinked the key, and actually destroying it + * may mean it is removed from hardware which requires that + * the key->sta pointer is still valid, so flush the key todo + * list here. + * + * ieee80211_key_todo() will synchronize_rcu() so after this + * nothing can reference this sta struct any more. + */ + ieee80211_key_todo(); + +#ifdef CONFIG_MAC80211_MESH + if (ieee80211_vif_is_mesh(&sta->sdata->vif)) + del_timer_sync(&sta->plink_timer); +#endif + while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) { local->total_ps_buffered--; dev_kfree_skb_any(skb); } - while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) { + + while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) dev_kfree_skb_any(skb); + + for (i = 0; i < STA_TID_NUM; i++) { + spin_lock_bh(&sta->ampdu_mlme.ampdu_rx); + if (sta->ampdu_mlme.tid_rx[i]) + del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer); + spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx); + spin_lock_bh(&sta->ampdu_mlme.ampdu_tx); + if (sta->ampdu_mlme.tid_tx[i]) + del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer); + spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx); } - for (i = 0; i < STA_TID_NUM; i++) - del_timer_sync(&sta->ampdu_mlme.tid_rx[i].session_timer); - rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv); - rate_control_put(sta->rate_ctrl); - kfree(sta); + + __sta_info_free(local, sta); } -void sta_info_put(struct sta_info *sta) +/* Caller must hold local->sta_lock */ +static void sta_info_hash_add(struct ieee80211_local *local, + struct sta_info *sta) { - kref_put(&sta->kref, sta_info_release); + sta->hnext = local->sta_hash[STA_HASH(sta->addr)]; + rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], sta); } -EXPORT_SYMBOL(sta_info_put); - -struct sta_info * sta_info_add(struct ieee80211_local *local, - struct net_device *dev, u8 *addr, gfp_t gfp) +struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, + u8 *addr, gfp_t gfp) { + struct ieee80211_local *local = sdata->local; struct sta_info *sta; int i; - DECLARE_MAC_BUF(mac); + DECLARE_MAC_BUF(mbuf); sta = kzalloc(sizeof(*sta), gfp); if (!sta) return NULL; - kref_init(&sta->kref); + memcpy(sta->addr, addr, ETH_ALEN); + sta->local = local; + sta->sdata = sdata; sta->rate_ctrl = rate_control_get(local->rate_ctrl); - sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp); + sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, + gfp); if (!sta->rate_ctrl_priv) { rate_control_put(sta->rate_ctrl); kfree(sta); return NULL; } - memcpy(sta->addr, addr, ETH_ALEN); - sta->local = local; - sta->dev = dev; spin_lock_init(&sta->ampdu_mlme.ampdu_rx); + spin_lock_init(&sta->ampdu_mlme.ampdu_tx); for (i = 0; i < STA_TID_NUM; i++) { /* timer_to_tid must be initialized with identity mapping to * enable session_timer's data differentiation. refer to * sta_rx_agg_session_timer_expired for useage */ sta->timer_to_tid[i] = i; - /* rx timers */ - sta->ampdu_mlme.tid_rx[i].session_timer.function = - sta_rx_agg_session_timer_expired; - sta->ampdu_mlme.tid_rx[i].session_timer.data = - (unsigned long)&sta->timer_to_tid[i]; - init_timer(&sta->ampdu_mlme.tid_rx[i].session_timer); + /* tid to tx queue: initialize according to HW (0 is valid) */ + sta->tid_to_tx_q[i] = local->hw.queues; + /* rx */ + sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE; + sta->ampdu_mlme.tid_rx[i] = NULL; + /* tx */ + sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE; + sta->ampdu_mlme.tid_tx[i] = NULL; + sta->ampdu_mlme.addba_req_num[i] = 0; } skb_queue_head_init(&sta->ps_tx_buf); skb_queue_head_init(&sta->tx_filtered); - __sta_info_get(sta); /* sta used by caller, decremented by - * sta_info_put() */ - write_lock_bh(&local->sta_lock); + +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + printk(KERN_DEBUG "%s: Allocated STA %s\n", + wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr)); +#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ + +#ifdef CONFIG_MAC80211_MESH + sta->plink_state = PLINK_LISTEN; + spin_lock_init(&sta->plink_lock); + init_timer(&sta->plink_timer); +#endif + + return sta; +} + +int sta_info_insert(struct sta_info *sta) +{ + struct ieee80211_local *local = sta->local; + struct ieee80211_sub_if_data *sdata = sta->sdata; + unsigned long flags; + int err = 0; + DECLARE_MAC_BUF(mac); + + /* + * Can't be a WARN_ON because it can be triggered through a race: + * something inserts a STA (on one CPU) without holding the RTNL + * and another CPU turns off the net device. + */ + if (unlikely(!netif_running(sdata->dev))) { + err = -ENETDOWN; + goto out_free; + } + + if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0 || + is_multicast_ether_addr(sta->addr))) { + err = -EINVAL; + goto out_free; + } + + spin_lock_irqsave(&local->sta_lock, flags); + /* check if STA exists already */ + if (__sta_info_find(local, sta->addr)) { + spin_unlock_irqrestore(&local->sta_lock, flags); + err = -EEXIST; + goto out_free; + } list_add(&sta->list, &local->sta_list); local->num_sta++; sta_info_hash_add(local, sta); - if (local->ops->sta_notify) { - struct ieee80211_sub_if_data *sdata; - sdata = IEEE80211_DEV_TO_SUB_IF(dev); + /* notify driver */ + if (local->ops->sta_notify) { if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) sdata = sdata->u.vlan.ap; local->ops->sta_notify(local_to_hw(local), &sdata->vif, - STA_NOTIFY_ADD, addr); + STA_NOTIFY_ADD, sta->addr); } - write_unlock_bh(&local->sta_lock); #ifdef CONFIG_MAC80211_VERBOSE_DEBUG - printk(KERN_DEBUG "%s: Added STA %s\n", - wiphy_name(local->hw.wiphy), print_mac(mac, addr)); + printk(KERN_DEBUG "%s: Inserted STA %s\n", + wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr)); #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ + spin_unlock_irqrestore(&local->sta_lock, flags); + #ifdef CONFIG_MAC80211_DEBUGFS - /* debugfs entry adding might sleep, so schedule process + /* + * Debugfs entry adding might sleep, so schedule process * context task for adding entry for STAs that do not yet - * have one. */ - queue_work(local->hw.workqueue, &local->sta_debugfs_add); + * have one. + * NOTE: due to auto-freeing semantics this may only be done + * if the insertion is successful! + */ + schedule_work(&local->sta_debugfs_add); #endif - return sta; + if (ieee80211_vif_is_mesh(&sdata->vif)) + mesh_accept_plinks_update(sdata); + + return 0; + out_free: + BUG_ON(!err); + __sta_info_free(local, sta); + return err; } -/* Caller must hold local->sta_lock */ -void sta_info_remove(struct sta_info *sta) +static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid) { - struct ieee80211_local *local = sta->local; - struct ieee80211_sub_if_data *sdata; + /* + * This format has been mandated by the IEEE specifications, + * so this line may not be changed to use the __set_bit() format. + */ + bss->tim[aid / 8] |= (1 << (aid % 8)); +} - /* don't do anything if we've been removed already */ - if (sta_info_hash_del(local, sta)) - return; +static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid) +{ + /* + * This format has been mandated by the IEEE specifications, + * so this line may not be changed to use the __clear_bit() format. + */ + bss->tim[aid / 8] &= ~(1 << (aid % 8)); +} - list_del(&sta->list); - sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); - if (sta->flags & WLAN_STA_PS) { - sta->flags &= ~WLAN_STA_PS; - if (sdata->bss) - atomic_dec(&sdata->bss->num_sta_ps); +static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss, + struct sta_info *sta) +{ + if (bss) + __bss_tim_set(bss, sta->aid); + if (sta->local->ops->set_tim) { + sta->local->tim_in_locked_section = true; + sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 1); + sta->local->tim_in_locked_section = false; } - local->num_sta--; - sta_info_remove_aid_ptr(sta); +} + +void sta_info_set_tim_bit(struct sta_info *sta) +{ + unsigned long flags; + spin_lock_irqsave(&sta->local->sta_lock, flags); + __sta_info_set_tim_bit(sta->sdata->bss, sta); + spin_unlock_irqrestore(&sta->local->sta_lock, flags); } -void sta_info_free(struct sta_info *sta) +static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss, + struct sta_info *sta) { - struct sk_buff *skb; - struct ieee80211_local *local = sta->local; - DECLARE_MAC_BUF(mac); + if (bss) + __bss_tim_clear(bss, sta->aid); + if (sta->local->ops->set_tim) { + sta->local->tim_in_locked_section = true; + sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 0); + sta->local->tim_in_locked_section = false; + } +} - might_sleep(); +void sta_info_clear_tim_bit(struct sta_info *sta) +{ + unsigned long flags; - write_lock_bh(&local->sta_lock); - sta_info_remove(sta); - write_unlock_bh(&local->sta_lock); + spin_lock_irqsave(&sta->local->sta_lock, flags); + __sta_info_clear_tim_bit(sta->sdata->bss, sta); + spin_unlock_irqrestore(&sta->local->sta_lock, flags); +} - while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) { - local->total_ps_buffered--; - dev_kfree_skb(skb); - } - while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) { - dev_kfree_skb(skb); +void __sta_info_unlink(struct sta_info **sta) +{ + struct ieee80211_local *local = (*sta)->local; + struct ieee80211_sub_if_data *sdata = (*sta)->sdata; +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + DECLARE_MAC_BUF(mbuf); +#endif + /* + * pull caller's reference if we're already gone. + */ + if (sta_info_hash_del(local, *sta)) { + *sta = NULL; + return; } -#ifdef CONFIG_MAC80211_VERBOSE_DEBUG - printk(KERN_DEBUG "%s: Removed STA %s\n", - wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr)); -#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ + if ((*sta)->key) { + ieee80211_key_free((*sta)->key); + WARN_ON((*sta)->key); + } - ieee80211_key_free(sta->key); - sta->key = NULL; + list_del(&(*sta)->list); - if (local->ops->sta_notify) { - struct ieee80211_sub_if_data *sdata; + if ((*sta)->flags & WLAN_STA_PS) { + (*sta)->flags &= ~WLAN_STA_PS; + if (sdata->bss) + atomic_dec(&sdata->bss->num_sta_ps); + __sta_info_clear_tim_bit(sdata->bss, *sta); + } - sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); + local->num_sta--; + if (local->ops->sta_notify) { if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) sdata = sdata->u.vlan.ap; local->ops->sta_notify(local_to_hw(local), &sdata->vif, - STA_NOTIFY_REMOVE, sta->addr); + STA_NOTIFY_REMOVE, (*sta)->addr); } - rate_control_remove_sta_debugfs(sta); - ieee80211_sta_debugfs_remove(sta); + if (ieee80211_vif_is_mesh(&sdata->vif)) { + mesh_accept_plinks_update(sdata); +#ifdef CONFIG_MAC80211_MESH + del_timer(&(*sta)->plink_timer); +#endif + } - sta_info_put(sta); +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + printk(KERN_DEBUG "%s: Removed STA %s\n", + wiphy_name(local->hw.wiphy), print_mac(mbuf, (*sta)->addr)); +#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ + + /* + * Finally, pull caller's reference if the STA is pinned by the + * task that is adding the debugfs entries. In that case, we + * leave the STA "to be freed". + * + * The rules are not trivial, but not too complex either: + * (1) pin_status is only modified under the sta_lock + * (2) STAs may only be pinned under the RTNL so that + * sta_info_flush() is guaranteed to actually destroy + * all STAs that are active for a given interface, this + * is required for correctness because otherwise we + * could notify a driver that an interface is going + * away and only after that (!) notify it about a STA + * on that interface going away. + * (3) sta_info_debugfs_add_work() will set the status + * to PINNED when it found an item that needs a new + * debugfs directory created. In that case, that item + * must not be freed although all *RCU* users are done + * with it. Hence, we tell the caller of _unlink() + * that the item is already gone (as can happen when + * two tasks try to unlink/destroy at the same time) + * (4) We set the pin_status to DESTROY here when we + * find such an item. + * (5) sta_info_debugfs_add_work() will reset the pin_status + * from PINNED to NORMAL when it is done with the item, + * but will check for DESTROY before resetting it in + * which case it will free the item. + */ + if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) { + (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY; + *sta = NULL; + return; + } } +void sta_info_unlink(struct sta_info **sta) +{ + struct ieee80211_local *local = (*sta)->local; + unsigned long flags; + + spin_lock_irqsave(&local->sta_lock, flags); + __sta_info_unlink(sta); + spin_unlock_irqrestore(&local->sta_lock, flags); +} static inline int sta_info_buffer_expired(struct ieee80211_local *local, struct sta_info *sta, @@ -299,6 +537,7 @@ static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local, { unsigned long flags; struct sk_buff *skb; + struct ieee80211_sub_if_data *sdata; DECLARE_MAC_BUF(mac); if (skb_queue_empty(&sta->ps_tx_buf)) @@ -307,21 +546,23 @@ static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local, for (;;) { spin_lock_irqsave(&sta->ps_tx_buf.lock, flags); skb = skb_peek(&sta->ps_tx_buf); - if (sta_info_buffer_expired(local, sta, skb)) { + if (sta_info_buffer_expired(local, sta, skb)) skb = __skb_dequeue(&sta->ps_tx_buf); - if (skb_queue_empty(&sta->ps_tx_buf)) - sta->flags &= ~WLAN_STA_TIM; - } else + else skb = NULL; spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags); - if (skb) { - local->total_ps_buffered--; - printk(KERN_DEBUG "Buffered frame expired (STA " - "%s)\n", print_mac(mac, sta->addr)); - dev_kfree_skb(skb); - } else + if (!skb) break; + + sdata = sta->sdata; + local->total_ps_buffered--; + printk(KERN_DEBUG "Buffered frame expired (STA " + "%s)\n", print_mac(mac, sta->addr)); + dev_kfree_skb(skb); + + if (skb_queue_empty(&sta->ps_tx_buf)) + sta_info_clear_tim_bit(sta); } } @@ -331,13 +572,10 @@ static void sta_info_cleanup(unsigned long data) struct ieee80211_local *local = (struct ieee80211_local *) data; struct sta_info *sta; - read_lock_bh(&local->sta_lock); - list_for_each_entry(sta, &local->sta_list, list) { - __sta_info_get(sta); + rcu_read_lock(); + list_for_each_entry_rcu(sta, &local->sta_list, list) sta_info_cleanup_expire_buffered(local, sta); - sta_info_put(sta); - } - read_unlock_bh(&local->sta_lock); + rcu_read_unlock(); local->sta_cleanup.expires = round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); @@ -345,38 +583,106 @@ static void sta_info_cleanup(unsigned long data) } #ifdef CONFIG_MAC80211_DEBUGFS -static void sta_info_debugfs_add_task(struct work_struct *work) +/* + * See comment in __sta_info_unlink, + * caller must hold local->sta_lock. + */ +static void __sta_info_pin(struct sta_info *sta) +{ + WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL); + sta->pin_status = STA_INFO_PIN_STAT_PINNED; +} + +/* + * See comment in __sta_info_unlink, returns sta if it + * needs to be destroyed. + */ +static struct sta_info *__sta_info_unpin(struct sta_info *sta) +{ + struct sta_info *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&sta->local->sta_lock, flags); + WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY && + sta->pin_status != STA_INFO_PIN_STAT_PINNED); + if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY) + ret = sta; + sta->pin_status = STA_INFO_PIN_STAT_NORMAL; + spin_unlock_irqrestore(&sta->local->sta_lock, flags); + + return ret; +} + +static void sta_info_debugfs_add_work(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, sta_debugfs_add); struct sta_info *sta, *tmp; + unsigned long flags; + /* We need to keep the RTNL across the whole pinned status. */ + rtnl_lock(); while (1) { sta = NULL; - read_lock_bh(&local->sta_lock); + + spin_lock_irqsave(&local->sta_lock, flags); list_for_each_entry(tmp, &local->sta_list, list) { if (!tmp->debugfs.dir) { sta = tmp; - __sta_info_get(sta); + __sta_info_pin(sta); break; } } - read_unlock_bh(&local->sta_lock); + spin_unlock_irqrestore(&local->sta_lock, flags); if (!sta) break; ieee80211_sta_debugfs_add(sta); rate_control_add_sta_debugfs(sta); - sta_info_put(sta); + + sta = __sta_info_unpin(sta); + sta_info_destroy(sta); } + rtnl_unlock(); } #endif +static void __ieee80211_run_pending_flush(struct ieee80211_local *local) +{ + struct sta_info *sta; + unsigned long flags; + + ASSERT_RTNL(); + + spin_lock_irqsave(&local->sta_lock, flags); + while (!list_empty(&local->sta_flush_list)) { + sta = list_first_entry(&local->sta_flush_list, + struct sta_info, list); + list_del(&sta->list); + spin_unlock_irqrestore(&local->sta_lock, flags); + sta_info_destroy(sta); + spin_lock_irqsave(&local->sta_lock, flags); + } + spin_unlock_irqrestore(&local->sta_lock, flags); +} + +static void ieee80211_sta_flush_work(struct work_struct *work) +{ + struct ieee80211_local *local = + container_of(work, struct ieee80211_local, sta_flush_work); + + rtnl_lock(); + __ieee80211_run_pending_flush(local); + rtnl_unlock(); +} + void sta_info_init(struct ieee80211_local *local) { - rwlock_init(&local->sta_lock); + spin_lock_init(&local->sta_lock); INIT_LIST_HEAD(&local->sta_list); + INIT_LIST_HEAD(&local->sta_flush_list); + INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work); setup_timer(&local->sta_cleanup, sta_info_cleanup, (unsigned long)local); @@ -384,7 +690,7 @@ void sta_info_init(struct ieee80211_local *local) round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); #ifdef CONFIG_MAC80211_DEBUGFS - INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task); + INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_work); #endif } @@ -397,47 +703,89 @@ int sta_info_start(struct ieee80211_local *local) void sta_info_stop(struct ieee80211_local *local) { del_timer(&local->sta_cleanup); + cancel_work_sync(&local->sta_flush_work); +#ifdef CONFIG_MAC80211_DEBUGFS + /* + * Make sure the debugfs adding work isn't pending after this + * because we're about to be destroyed. It doesn't matter + * whether it ran or not since we're going to flush all STAs + * anyway. + */ + cancel_work_sync(&local->sta_debugfs_add); +#endif + + rtnl_lock(); sta_info_flush(local, NULL); + __ieee80211_run_pending_flush(local); + rtnl_unlock(); } -void sta_info_remove_aid_ptr(struct sta_info *sta) +/** + * sta_info_flush - flush matching STA entries from the STA table + * + * Returns the number of removed STA entries. + * + * @local: local interface data + * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs + */ +int sta_info_flush(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata) { - struct ieee80211_sub_if_data *sdata; + struct sta_info *sta, *tmp; + LIST_HEAD(tmp_list); + int ret = 0; + unsigned long flags; - if (sta->aid <= 0) - return; + might_sleep(); + ASSERT_RTNL(); + + spin_lock_irqsave(&local->sta_lock, flags); + list_for_each_entry_safe(sta, tmp, &local->sta_list, list) { + if (!sdata || sdata == sta->sdata) { + __sta_info_unlink(&sta); + if (sta) { + list_add_tail(&sta->list, &tmp_list); + ret++; + } + } + } + spin_unlock_irqrestore(&local->sta_lock, flags); - sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); + list_for_each_entry_safe(sta, tmp, &tmp_list, list) + sta_info_destroy(sta); - if (sdata->local->ops->set_tim) - sdata->local->ops->set_tim(local_to_hw(sdata->local), - sta->aid, 0); - if (sdata->bss) - __bss_tim_clear(sdata->bss, sta->aid); + return ret; } - /** - * sta_info_flush - flush matching STA entries from the STA table - * @local: local interface data - * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs + * sta_info_flush_delayed - flush matching STA entries from the STA table + * + * This function unlinks all stations for a given interface and queues + * them for freeing. Note that the workqueue function scheduled here has + * to run before any new keys can be added to the system to avoid set_key() + * callback ordering issues. + * + * @sdata: the interface */ -void sta_info_flush(struct ieee80211_local *local, struct net_device *dev) +void sta_info_flush_delayed(struct ieee80211_sub_if_data *sdata) { + struct ieee80211_local *local = sdata->local; struct sta_info *sta, *tmp; - LIST_HEAD(tmp_list); - - write_lock_bh(&local->sta_lock); - list_for_each_entry_safe(sta, tmp, &local->sta_list, list) - if (!dev || dev == sta->dev) { - __sta_info_get(sta); - sta_info_remove(sta); - list_add_tail(&sta->list, &tmp_list); + unsigned long flags; + bool work = false; + + spin_lock_irqsave(&local->sta_lock, flags); + list_for_each_entry_safe(sta, tmp, &local->sta_list, list) { + if (sdata == sta->sdata) { + __sta_info_unlink(&sta); + if (sta) { + list_add_tail(&sta->list, + &local->sta_flush_list); + work = true; + } } - write_unlock_bh(&local->sta_lock); - - list_for_each_entry_safe(sta, tmp, &tmp_list, list) { - sta_info_free(sta); - sta_info_put(sta); } + if (work) + schedule_work(&local->sta_flush_work); + spin_unlock_irqrestore(&local->sta_lock, flags); } |