Divided the sta_info_insert_rcu function to 3 mini-functions:
sta_info_insert_check - the initial checks done when inserting
a new station
sta_info_insert_ibss - the function that handles the station
addition for IBSS interfaces
sta_info_insert_non_ibss - the function that handles the station
addition in other cases
The outer API was not changed.
The refactoring was done for better usage of the different
stages in the station addition in new scenarios added
in the next commit.
Signed-off-by: Guy Eilam <[email protected]>
---
net/mac80211/sta_info.c | 148 ++++++++++++++++++++++++++++++-----------------
1 files changed, 95 insertions(+), 53 deletions(-)
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 5eaa167..d469d9d 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -368,93 +368,90 @@ 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(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;
+ 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;
+ return -EEXIST;
}
spin_unlock_irqrestore(&local->sta_lock, flags);
@@ -463,7 +460,7 @@ int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
if (err) {
mutex_unlock(&local->sta_mtx);
rcu_read_lock();
- goto out_free;
+ return err;
}
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
@@ -478,6 +475,51 @@ 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);
--
1.7.4.1
When associating to an AP, the station might miss the first EAP
packet that the AP sends due to a race condition between the association
success procedure and the rx flow in mac80211.
In such cases, the packet might fall in ieee80211_rx_h_check due to
the fact that the relevant rx->sta wasn't allocated yet.
Allocation of the relevant station info struct before actually
sending the association request and setting it with a new
dummy_sta flag solve this problem.
The station will accept only EAP packets from the AP while it
is in the pre-association/dummy state.
This dummy station entry is not seen by normal sta_info_get()
calls, only by sta_info_get_bss_rx().
The driver is not notified for the first insertion of the
dummy station. The driver is notified only after the association
is complete and the dummy flag is removed from the station entry.
That way, all the rest of the code flow should be untouched by
this change.
Signed-off-by: Guy Eilam <[email protected]>
---
net/mac80211/mlme.c | 59 +++++++++++++--
net/mac80211/rx.c | 21 ++++-
net/mac80211/sta_info.c | 186 ++++++++++++++++++++++++++++++++++------------
net/mac80211/sta_info.h | 30 +++++++-
4 files changed, 236 insertions(+), 60 deletions(-)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d6470c7..60a6f27 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1482,10 +1482,14 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk,
ifmgd->aid = aid;
- sta = sta_info_alloc(sdata, cbss->bssid, GFP_KERNEL);
- if (!sta) {
- printk(KERN_DEBUG "%s: failed to alloc STA entry for"
- " the AP\n", sdata->name);
+ mutex_lock(&sdata->local->sta_mtx);
+ /*
+ * station info was already allocated and inserted before
+ * the association and should be available to us
+ */
+ sta = sta_info_get_rx(sdata, cbss->bssid);
+ if (WARN_ON(!sta)) {
+ mutex_unlock(&sdata->local->sta_mtx);
return false;
}
@@ -1556,7 +1560,8 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk,
if (elems.wmm_param)
set_sta_flags(sta, WLAN_STA_WME);
- err = sta_info_insert(sta);
+ /* sta_info_reinsert will also unlock the mutex lock */
+ err = sta_info_reinsert(sta);
sta = NULL;
if (err) {
printk(KERN_DEBUG "%s: failed to insert STA entry for"
@@ -2429,6 +2434,32 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
return 0;
}
+/* create and insert a dummy station entry */
+static int ieee80211_pre_assoc(struct ieee80211_sub_if_data *sdata,
+ u8 *bssid) {
+ struct sta_info *sta;
+ int err;
+
+ sta = sta_info_alloc(sdata, bssid, GFP_KERNEL);
+ if (!sta) {
+ printk(KERN_DEBUG "%s: failed to alloc STA entry for"
+ " the AP\n", sdata->name);
+ return -ENOMEM;
+ }
+
+ sta->dummy = true;
+
+ err = sta_info_insert(sta);
+ sta = NULL;
+ if (err) {
+ printk(KERN_DEBUG "%s: failed to insert Dummy STA entry for"
+ " the AP (error %d)\n", sdata->name, err);
+ return err;
+ }
+
+ return 0;
+}
+
static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
struct sk_buff *skb)
{
@@ -2436,9 +2467,11 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
struct ieee80211_mgmt *mgmt;
struct ieee80211_rx_status *rx_status;
struct ieee802_11_elems elems;
+ struct cfg80211_bss *cbss = wk->assoc.bss;
u16 status;
if (!skb) {
+ sta_info_destroy_addr(wk->sdata, cbss->bssid);
cfg80211_send_assoc_timeout(wk->sdata->dev, wk->filter_ta);
goto destroy;
}
@@ -2468,12 +2501,16 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
if (!ieee80211_assoc_success(wk, mgmt, skb->len)) {
mutex_unlock(&wk->sdata->u.mgd.mtx);
/* oops -- internal error -- send timeout for now */
+ sta_info_destroy_addr(wk->sdata, cbss->bssid);
cfg80211_send_assoc_timeout(wk->sdata->dev,
wk->filter_ta);
return WORK_DONE_DESTROY;
}
mutex_unlock(&wk->sdata->u.mgd.mtx);
+ } else {
+ /* assoc failed - destroy the dummy station entry */
+ sta_info_destroy_addr(wk->sdata, cbss->bssid);
}
cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
@@ -2492,7 +2529,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
struct ieee80211_bss *bss = (void *)req->bss->priv;
struct ieee80211_work *wk;
const u8 *ssid;
- int i;
+ int i, err;
mutex_lock(&ifmgd->mtx);
if (ifmgd->associated) {
@@ -2517,6 +2554,16 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
if (!wk)
return -ENOMEM;
+ /*
+ * create a dummy station info entry in order
+ * to start accepting incoming EAPOL packets from the station
+ */
+ err = ieee80211_pre_assoc(sdata, req->bss->bssid);
+ if (err) {
+ kfree(wk);
+ return err;
+ }
+
ifmgd->flags &= ~IEEE80211_STA_DISABLE_11N;
ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index fe2c2a7..7b5e3f3 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -850,8 +850,21 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
ieee80211_is_pspoll(hdr->frame_control)) &&
rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
- (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
+ (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
+ if (rx->sta && rx->sta->dummy &&
+ ieee80211_is_data_present(hdr->frame_control)) {
+ u16 ethertype;
+ u8 *payload;
+
+ payload = rx->skb->data +
+ ieee80211_hdrlen(hdr->frame_control);
+ ethertype = (payload[6] << 8) | payload[7];
+ if (cpu_to_be16(ethertype) ==
+ rx->sdata->control_port_protocol)
+ return RX_CONTINUE;
+ }
return RX_DROP_MONITOR;
+ }
return RX_CONTINUE;
}
@@ -2791,7 +2804,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
if (ieee80211_is_data(fc)) {
prev_sta = NULL;
- for_each_sta_info(local, hdr->addr2, sta, tmp) {
+ for_each_sta_info_rx(local, hdr->addr2, sta, tmp) {
if (!prev_sta) {
prev_sta = sta;
continue;
@@ -2835,7 +2848,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
continue;
}
- rx.sta = sta_info_get_bss(prev, hdr->addr2);
+ rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
rx.sdata = prev;
ieee80211_prepare_and_rx_handle(&rx, skb, false);
@@ -2843,7 +2856,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
}
if (prev) {
- rx.sta = sta_info_get_bss(prev, hdr->addr2);
+ rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
rx.sdata = prev;
if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index d469d9d..17caba2 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -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,
@@ -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;
@@ -290,51 +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);
-
- memset(&sinfo, 0, sizeof(sinfo));
- 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;
}
@@ -351,7 +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);
}
@@ -395,7 +450,7 @@ static int sta_info_insert_ibss(struct sta_info *sta) __acquires(RCU)
spin_lock_irqsave(&local->sta_lock, flags);
/* check if STA exists already */
- if (sta_info_get_bss(sdata, sta->sta.addr)) {
+ if (sta_info_get_bss_rx(sdata, sta->sta.addr)) {
spin_unlock_irqrestore(&local->sta_lock, flags);
rcu_read_lock();
return -EEXIST;
@@ -431,6 +486,8 @@ 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);
@@ -446,17 +503,28 @@ static int sta_info_insert_non_ibss(struct sta_info *sta) __acquires(RCU)
*/
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();
- return -EEXIST;
+ /*
+ * 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();
@@ -464,7 +532,8 @@ static int sta_info_insert_non_ibss(struct sta_info *sta) __acquires(RCU)
}
#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 */
@@ -535,6 +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)
{
/*
@@ -775,7 +863,7 @@ 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);
@@ -789,7 +877,7 @@ 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);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 28beb78..e9eb565 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -238,10 +238,12 @@ struct sta_ampdu_mlme {
* @plink_timer: peer link watch timer
* @plink_timer_was_running: used by suspend/resume to restore timers
* @debugfs: debug filesystem info
- * @sta: station information we share with the driver
* @dead: set to true when sta is unlinked
* @uploaded: set to true when sta is uploaded to the driver
* @lost_packets: number of consecutive lost packets
+ * @dummy: indicate a dummy station created for receiving
+ * EAP frames before association
+ * @sta: station information we share with the driver
*/
struct sta_info {
/* General information, mostly static */
@@ -336,6 +338,9 @@ struct sta_info {
unsigned int lost_packets;
+ /* should be right in front of sta to be in the same cache line */
+ bool dummy;
+
/* keep last! */
struct ieee80211_sta sta;
};
@@ -436,9 +441,15 @@ rcu_dereference_protected_tid_tx(struct sta_info *sta, int tid)
struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
+struct sta_info *sta_info_get_rx(struct ieee80211_sub_if_data *sdata,
+ const u8 *addr);
+
struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
+struct sta_info *sta_info_get_bss_rx(struct ieee80211_sub_if_data *sdata,
+ const u8 *addr);
+
static inline
void for_each_sta_info_type_check(struct ieee80211_local *local,
const u8 *addr,
@@ -459,6 +470,22 @@ void for_each_sta_info_type_check(struct ieee80211_local *local,
_sta = nxt, \
nxt = _sta ? rcu_dereference(_sta->hnext) : NULL \
) \
+ /* run code only if address matches and it's not a dummy sta */ \
+ if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0 && \
+ !_sta->dummy)
+
+#define for_each_sta_info_rx(local, _addr, _sta, nxt) \
+ for ( /* initialise loop */ \
+ _sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
+ nxt = _sta ? rcu_dereference(_sta->hnext) : NULL; \
+ /* typecheck */ \
+ for_each_sta_info_type_check(local, (_addr), _sta, nxt),\
+ /* continue condition */ \
+ _sta; \
+ /* advance loop */ \
+ _sta = nxt, \
+ nxt = _sta ? rcu_dereference(_sta->hnext) : NULL \
+ ) \
/* compare address and run code only if it matches */ \
if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0)
@@ -484,6 +511,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
int sta_info_insert(struct sta_info *sta);
int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
int sta_info_insert_atomic(struct sta_info *sta);
+int sta_info_reinsert(struct sta_info *sta);
int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
--
1.7.4.1
On Wed, 2011-08-17 at 15:18 +0300, Guy Eilam wrote:
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -850,8 +850,21 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
> ieee80211_is_pspoll(hdr->frame_control)) &&
> rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
> rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
> - (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
> + (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
> + if (rx->sta && rx->sta->dummy &&
> + ieee80211_is_data_present(hdr->frame_control)) {
> + u16 ethertype;
> + u8 *payload;
> +
> + payload = rx->skb->data +
> + ieee80211_hdrlen(hdr->frame_control);
> + ethertype = (payload[6] << 8) | payload[7];
> + if (cpu_to_be16(ethertype) ==
> + rx->sdata->control_port_protocol)
> + return RX_CONTINUE;
> + }
> return RX_DROP_MONITOR;
> + }
It might be easier to read to split the outer condition now into
data/ps-poll?
Anyway, didn't pay attention if this got applied -- seems fine.
johannes
On Wed, Aug 17, 2011 at 03:18:15PM +0300, Guy Eilam wrote:
> Allocation of the relevant station info struct before actually
> sending the association request and setting it with a new
> dummy_sta flag solve this problem.
> This dummy station entry is not seen by normal sta_info_get()
> calls, only by sta_info_get_bss_rx().
> The driver is not notified for the first insertion of the
> dummy station. The driver is notified only after the association
> is complete and the dummy flag is removed from the station entry.
I'm seeing issues with that dummy entry not getting removed and every
consecutive association attempt failing since ieee80211_pre_assoc()
fails to insert the new dummy station entry (sta_info_insert() returns
-EEXIST).
This happens at least in the case where association comeback mechanism
is used and the association fails:
[17726.918932] wlan0: authenticate with 00:03:7f:12:2a:14 (try 1)
[17726.921063] wlan0: authenticated
[17726.921079] ieee80211 phy0: device now idle
[17726.922992] ieee80211 phy0: Allocated STA 00:03:7f:12:2a:14
[17726.923000] ieee80211 phy0: Inserted dummy STA 00:03:7f:12:2a:14
[17726.930772] ieee80211 phy0: device no longer idle - working
[17726.941184] wlan0: associate with 00:03:7f:12:2a:14 (try 1)
[17726.945652] wlan0: RX ReassocResp from 00:03:7f:12:2a:14 (capab=0x411 status=30 aid=1)
[17726.945657] wlan0: 00:03:7f:12:2a:14 rejected association temporarily; comeback duration 1000 TU (1024 ms)
[17727.968031] wlan0: associate with 00:03:7f:12:2a:14 (try 2)
[17727.970915] wlan0: deauthenticated from 00:03:7f:12:2a:14 (Reason: 6)
Note: There is no "Removed STA" message here, i.e., __sta_info_destroy()
does not get called because we do not get to the ieee80211_assoc_done()
work in this case.. Is that the main issue here? Or should that dummy
STA entry be removed somewhere else in this type of case? Or should
ieee80211_pre_assoc() just accept -EEXIST and allow the new association
to continue?
The next connection attempt fails:
[18016.942906] wlan0: authenticate with 00:03:7f:12:2a:14 (try 1)
[18016.945114] wlan0: authenticated
[18016.945130] ieee80211 phy0: device now idle
[18016.945344] ieee80211 phy0: Allocated STA 00:03:7f:12:2a:14
[18016.945353] ieee80211 phy0: Destroyed STA 00:03:7f:12:2a:14
[18016.945356] wlan0: failed to insert Dummy STA entry for the AP (error -17)
and the dummy entry gets finally removed only when the interface is set
down:
[18036.716235] wlan0: deauthenticating from 00:03:7f:12:2a:14 by local choice (reason=3)
[18036.780038] ieee80211 phy0: Removed STA 00:03:7f:12:2a:14
[18036.780050] ieee80211 phy0: Destroyed STA 00:03:7f:12:2a:14
> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
> index d6470c7..60a6f27 100644
> --- a/net/mac80211/mlme.c
> +++ b/net/mac80211/mlme.c
>
> +/* create and insert a dummy station entry */
> +static int ieee80211_pre_assoc(struct ieee80211_sub_if_data *sdata,
> + u8 *bssid) {
> + struct sta_info *sta;
> + int err;
> +
> + sta = sta_info_alloc(sdata, bssid, GFP_KERNEL);
> + if (!sta) {
> + printk(KERN_DEBUG "%s: failed to alloc STA entry for"
> + " the AP\n", sdata->name);
> + return -ENOMEM;
> + }
> +
> + sta->dummy = true;
> +
> + err = sta_info_insert(sta);
> + sta = NULL;
> + if (err) {
> + printk(KERN_DEBUG "%s: failed to insert Dummy STA entry for"
> + " the AP (error %d)\n", sdata->name, err);
> + return err;
> + }
This is the place where the consecutive connections fail..
> @@ -2468,12 +2501,16 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
> if (!ieee80211_assoc_success(wk, mgmt, skb->len)) {
> mutex_unlock(&wk->sdata->u.mgd.mtx);
> /* oops -- internal error -- send timeout for now */
> + sta_info_destroy_addr(wk->sdata, cbss->bssid);
> cfg80211_send_assoc_timeout(wk->sdata->dev,
> wk->filter_ta);
> return WORK_DONE_DESTROY;
> }
>
> mutex_unlock(&wk->sdata->u.mgd.mtx);
> + } else {
> + /* assoc failed - destroy the dummy station entry */
> + sta_info_destroy_addr(wk->sdata, cbss->bssid);
> }
And this is the place where I guess the dummy entry was supposed to get
removed, but it wasn't in the assoc comeback case.
This makes it quite painful to run any IEEE 802.11w testing.. Making
ieee80211_pre_assoc() ignore EEXIST works around the issues, but a more
proper fix could be to make sure that the dummy entry gets removed when
we stop trying to associate in whatever ways that may happen.
--
Jouni Malinen PGP id EFC895FA