diff options
Diffstat (limited to 'net/mac80211/sta_info.c')
-rw-r--r-- | net/mac80211/sta_info.c | 347 |
1 files changed, 237 insertions, 110 deletions
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 21070e9bc8d0..0a7e0fed3251 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -72,7 +72,7 @@ static int sta_info_hash_del(struct ieee80211_local *local, if (!s) return -ENOENT; if (s == sta) { - rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], + RCU_INIT_POINTER(local->sta_hash[STA_HASH(sta->sta.addr)], s->hnext); return 0; } @@ -82,7 +82,7 @@ static int sta_info_hash_del(struct ieee80211_local *local, s = rcu_dereference_protected(s->hnext, lockdep_is_held(&local->sta_lock)); if (rcu_access_pointer(s->hnext)) { - rcu_assign_pointer(s->hnext, sta->hnext); + RCU_INIT_POINTER(s->hnext, sta->hnext); return 0; } @@ -100,6 +100,27 @@ struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata, lockdep_is_held(&local->sta_lock) || lockdep_is_held(&local->sta_mtx)); while (sta) { + if (sta->sdata == sdata && !sta->dummy && + memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) + break; + sta = rcu_dereference_check(sta->hnext, + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); + } + return sta; +} + +/* get a station info entry even if it is a dummy station*/ +struct sta_info *sta_info_get_rx(struct ieee80211_sub_if_data *sdata, + const u8 *addr) +{ + struct ieee80211_local *local = sdata->local; + struct sta_info *sta; + + sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)], + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); + while (sta) { if (sta->sdata == sdata && memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) break; @@ -126,6 +147,32 @@ struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata, while (sta) { if ((sta->sdata == sdata || (sta->sdata->bss && sta->sdata->bss == sdata->bss)) && + !sta->dummy && + memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) + break; + sta = rcu_dereference_check(sta->hnext, + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); + } + return sta; +} + +/* + * Get sta info either from the specified interface + * or from one of its vlans (including dummy stations) + */ +struct sta_info *sta_info_get_bss_rx(struct ieee80211_sub_if_data *sdata, + const u8 *addr) +{ + struct ieee80211_local *local = sdata->local; + struct sta_info *sta; + + sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)], + lockdep_is_held(&local->sta_lock) || + lockdep_is_held(&local->sta_mtx)); + while (sta) { + if ((sta->sdata == sdata || + (sta->sdata->bss && sta->sdata->bss == sdata->bss)) && memcmp(sta->sta.addr, addr, ETH_ALEN) == 0) break; sta = rcu_dereference_check(sta->hnext, @@ -184,7 +231,7 @@ static void sta_info_hash_add(struct ieee80211_local *local, struct sta_info *sta) { sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)]; - rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta); + RCU_INIT_POINTER(local->sta_hash[STA_HASH(sta->sta.addr)], sta); } static void sta_unblock(struct work_struct *wk) @@ -280,7 +327,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, return sta; } -static int sta_info_finish_insert(struct sta_info *sta, bool async) +static int sta_info_finish_insert(struct sta_info *sta, + bool async, bool dummy_reinsert) { struct ieee80211_local *local = sta->local; struct ieee80211_sub_if_data *sdata = sta->sdata; @@ -290,50 +338,58 @@ static int sta_info_finish_insert(struct sta_info *sta, bool async) lockdep_assert_held(&local->sta_mtx); - /* notify driver */ - if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) - sdata = container_of(sdata->bss, - struct ieee80211_sub_if_data, - u.ap); - err = drv_sta_add(local, sdata, &sta->sta); - if (err) { - if (!async) - return err; - printk(KERN_DEBUG "%s: failed to add IBSS STA %pM to driver (%d)" - " - keeping it anyway.\n", - sdata->name, sta->sta.addr, err); - } else { - sta->uploaded = true; + if (!sta->dummy || dummy_reinsert) { + /* notify driver */ + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) + sdata = container_of(sdata->bss, + struct ieee80211_sub_if_data, + u.ap); + err = drv_sta_add(local, sdata, &sta->sta); + if (err) { + if (!async) + return err; + printk(KERN_DEBUG "%s: failed to add IBSS STA %pM to " + "driver (%d) - keeping it anyway.\n", + sdata->name, sta->sta.addr, err); + } else { + sta->uploaded = true; #ifdef CONFIG_MAC80211_VERBOSE_DEBUG - if (async) - wiphy_debug(local->hw.wiphy, - "Finished adding IBSS STA %pM\n", - sta->sta.addr); + if (async) + wiphy_debug(local->hw.wiphy, + "Finished adding IBSS STA %pM\n", + sta->sta.addr); #endif + } + + sdata = sta->sdata; } - sdata = sta->sdata; + if (!dummy_reinsert) { + if (!async) { + local->num_sta++; + local->sta_generation++; + smp_mb(); - if (!async) { - local->num_sta++; - local->sta_generation++; - smp_mb(); + /* make the station visible */ + spin_lock_irqsave(&local->sta_lock, flags); + sta_info_hash_add(local, sta); + spin_unlock_irqrestore(&local->sta_lock, flags); + } - /* make the station visible */ - spin_lock_irqsave(&local->sta_lock, flags); - sta_info_hash_add(local, sta); - spin_unlock_irqrestore(&local->sta_lock, flags); + list_add(&sta->list, &local->sta_list); + } else { + sta->dummy = false; } - list_add(&sta->list, &local->sta_list); - - ieee80211_sta_debugfs_add(sta); - rate_control_add_sta_debugfs(sta); - - sinfo.filled = 0; - sinfo.generation = local->sta_generation; - cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL); + if (!sta->dummy) { + ieee80211_sta_debugfs_add(sta); + rate_control_add_sta_debugfs(sta); + memset(&sinfo, 0, sizeof(sinfo)); + sinfo.filled = 0; + sinfo.generation = local->sta_generation; + cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL); + } return 0; } @@ -350,7 +406,7 @@ static void sta_info_finish_pending(struct ieee80211_local *local) list_del(&sta->list); spin_unlock_irqrestore(&local->sta_lock, flags); - sta_info_finish_insert(sta, true); + sta_info_finish_insert(sta, true, false); spin_lock_irqsave(&local->sta_lock, flags); } @@ -367,106 +423,117 @@ static void sta_info_finish_work(struct work_struct *work) mutex_unlock(&local->sta_mtx); } -int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU) +static int sta_info_insert_check(struct sta_info *sta) { - struct ieee80211_local *local = sta->local; struct ieee80211_sub_if_data *sdata = sta->sdata; - unsigned long flags; - int err = 0; /* * 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(!ieee80211_sdata_running(sdata))) { - err = -ENETDOWN; - rcu_read_lock(); - goto out_free; - } + if (unlikely(!ieee80211_sdata_running(sdata))) + return -ENETDOWN; if (WARN_ON(compare_ether_addr(sta->sta.addr, sdata->vif.addr) == 0 || - is_multicast_ether_addr(sta->sta.addr))) { - err = -EINVAL; + is_multicast_ether_addr(sta->sta.addr))) + return -EINVAL; + + return 0; +} + +static int sta_info_insert_ibss(struct sta_info *sta) __acquires(RCU) +{ + struct ieee80211_local *local = sta->local; + struct ieee80211_sub_if_data *sdata = sta->sdata; + unsigned long flags; + + spin_lock_irqsave(&local->sta_lock, flags); + /* check if STA exists already */ + if (sta_info_get_bss_rx(sdata, sta->sta.addr)) { + spin_unlock_irqrestore(&local->sta_lock, flags); rcu_read_lock(); - goto out_free; + return -EEXIST; } - /* - * In ad-hoc mode, we sometimes need to insert stations - * from tasklet context from the RX path. To avoid races, - * always do so in that case -- see the comment below. - */ - if (sdata->vif.type == NL80211_IFTYPE_ADHOC) { - spin_lock_irqsave(&local->sta_lock, flags); - /* check if STA exists already */ - if (sta_info_get_bss(sdata, sta->sta.addr)) { - spin_unlock_irqrestore(&local->sta_lock, flags); - rcu_read_lock(); - err = -EEXIST; - goto out_free; - } - - local->num_sta++; - local->sta_generation++; - smp_mb(); - sta_info_hash_add(local, sta); + local->num_sta++; + local->sta_generation++; + smp_mb(); + sta_info_hash_add(local, sta); - list_add_tail(&sta->list, &local->sta_pending_list); + list_add_tail(&sta->list, &local->sta_pending_list); - rcu_read_lock(); - spin_unlock_irqrestore(&local->sta_lock, flags); + rcu_read_lock(); + spin_unlock_irqrestore(&local->sta_lock, flags); #ifdef CONFIG_MAC80211_VERBOSE_DEBUG - wiphy_debug(local->hw.wiphy, "Added IBSS STA %pM\n", - sta->sta.addr); + wiphy_debug(local->hw.wiphy, "Added IBSS STA %pM\n", + sta->sta.addr); #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ - ieee80211_queue_work(&local->hw, &local->sta_finish_work); + ieee80211_queue_work(&local->hw, &local->sta_finish_work); - return 0; - } + return 0; +} + +/* + * should be called with sta_mtx locked + * this function replaces the mutex lock + * with a RCU lock + */ +static int sta_info_insert_non_ibss(struct sta_info *sta) __acquires(RCU) +{ + struct ieee80211_local *local = sta->local; + struct ieee80211_sub_if_data *sdata = sta->sdata; + unsigned long flags; + struct sta_info *exist_sta; + bool dummy_reinsert = false; + int err = 0; + + lockdep_assert_held(&local->sta_mtx); /* * On first glance, this will look racy, because the code - * below this point, which inserts a station with sleeping, + * in this function, which inserts a station with sleeping, * unlocks the sta_lock between checking existence in the * hash table and inserting into it. * * However, it is not racy against itself because it keeps - * the mutex locked. It still seems to race against the - * above code that atomically inserts the station... That, - * however, is not true because the above code can only - * be invoked for IBSS interfaces, and the below code will - * not be -- and the two do not race against each other as - * the hash table also keys off the interface. + * the mutex locked. */ - might_sleep(); - - mutex_lock(&local->sta_mtx); - spin_lock_irqsave(&local->sta_lock, flags); - /* check if STA exists already */ - if (sta_info_get_bss(sdata, sta->sta.addr)) { - spin_unlock_irqrestore(&local->sta_lock, flags); - mutex_unlock(&local->sta_mtx); - rcu_read_lock(); - err = -EEXIST; - goto out_free; + /* + * check if STA exists already. + * only accept a scenario of a second call to sta_info_insert_non_ibss + * with a dummy station entry that was inserted earlier + * in that case - assume that the dummy station flag should + * be removed. + */ + exist_sta = sta_info_get_bss_rx(sdata, sta->sta.addr); + if (exist_sta) { + if (exist_sta == sta && sta->dummy) { + dummy_reinsert = true; + } else { + spin_unlock_irqrestore(&local->sta_lock, flags); + mutex_unlock(&local->sta_mtx); + rcu_read_lock(); + return -EEXIST; + } } spin_unlock_irqrestore(&local->sta_lock, flags); - err = sta_info_finish_insert(sta, false); + err = sta_info_finish_insert(sta, false, dummy_reinsert); if (err) { mutex_unlock(&local->sta_mtx); rcu_read_lock(); - goto out_free; + return err; } #ifdef CONFIG_MAC80211_VERBOSE_DEBUG - wiphy_debug(local->hw.wiphy, "Inserted STA %pM\n", sta->sta.addr); + wiphy_debug(local->hw.wiphy, "Inserted %sSTA %pM\n", + sta->dummy ? "dummy " : "", sta->sta.addr); #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ /* move reference to rcu-protected */ @@ -477,6 +544,51 @@ int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU) mesh_accept_plinks_update(sdata); return 0; +} + +int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU) +{ + struct ieee80211_local *local = sta->local; + struct ieee80211_sub_if_data *sdata = sta->sdata; + int err = 0; + + err = sta_info_insert_check(sta); + if (err) { + rcu_read_lock(); + goto out_free; + } + + /* + * In ad-hoc mode, we sometimes need to insert stations + * from tasklet context from the RX path. To avoid races, + * always do so in that case -- see the comment below. + */ + if (sdata->vif.type == NL80211_IFTYPE_ADHOC) { + err = sta_info_insert_ibss(sta); + if (err) + goto out_free; + + return 0; + } + + /* + * It might seem that the function called below is in race against + * the function call above that atomically inserts the station... That, + * however, is not true because the above code can only + * be invoked for IBSS interfaces, and the below code will + * not be -- and the two do not race against each other as + * the hash table also keys off the interface. + */ + + might_sleep(); + + mutex_lock(&local->sta_mtx); + + err = sta_info_insert_non_ibss(sta); + if (err) + goto out_free; + + return 0; out_free: BUG_ON(!err); __sta_info_free(local, sta); @@ -492,6 +604,25 @@ int sta_info_insert(struct sta_info *sta) return err; } +/* Caller must hold sta->local->sta_mtx */ +int sta_info_reinsert(struct sta_info *sta) +{ + struct ieee80211_local *local = sta->local; + int err = 0; + + err = sta_info_insert_check(sta); + if (err) { + mutex_unlock(&local->sta_mtx); + return err; + } + + might_sleep(); + + err = sta_info_insert_non_ibss(sta); + rcu_read_unlock(); + return err; +} + static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid) { /* @@ -560,14 +691,13 @@ void sta_info_clear_tim_bit(struct sta_info *sta) spin_unlock_irqrestore(&sta->local->sta_lock, flags); } -static int sta_info_buffer_expired(struct sta_info *sta, - struct sk_buff *skb) +static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb) { struct ieee80211_tx_info *info; int timeout; if (!skb) - return 0; + return false; info = IEEE80211_SKB_CB(skb); @@ -587,9 +717,6 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local, unsigned long flags; struct sk_buff *skb; - if (skb_queue_empty(&sta->ps_tx_buf)) - return false; - for (;;) { spin_lock_irqsave(&sta->ps_tx_buf.lock, flags); skb = skb_peek(&sta->ps_tx_buf); @@ -614,7 +741,7 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local, sta_info_clear_tim_bit(sta); } - return true; + return !skb_queue_empty(&sta->ps_tx_buf); } static int __must_check __sta_info_destroy(struct sta_info *sta) @@ -672,7 +799,7 @@ static int __must_check __sta_info_destroy(struct sta_info *sta) local->sta_generation++; if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) - rcu_assign_pointer(sdata->u.vlan.sta, NULL); + RCU_INIT_POINTER(sdata->u.vlan.sta, NULL); if (sta->uploaded) { if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) @@ -732,7 +859,7 @@ int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr) int ret; mutex_lock(&sdata->local->sta_mtx); - sta = sta_info_get(sdata, addr); + sta = sta_info_get_rx(sdata, addr); ret = __sta_info_destroy(sta); mutex_unlock(&sdata->local->sta_mtx); @@ -746,7 +873,7 @@ int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata, int ret; mutex_lock(&sdata->local->sta_mtx); - sta = sta_info_get_bss(sdata, addr); + sta = sta_info_get_bss_rx(sdata, addr); ret = __sta_info_destroy(sta); mutex_unlock(&sdata->local->sta_mtx); |