mac80211: station state transition error handling
In the future, when we start notifying drivers,
state transitions could potentially fail. To make
it easier to distinguish between programming bugs
and driver failures:
* rename sta_info_move_state() to
sta_info_pre_move_state() which can only be
called before the station is inserted (and
check this with a new station flag).
* rename sta_info_move_state_checked() to just
plain sta_info_move_state(), as it will be
the regular function that can fail for more
than just one reason (bad transition or an
error from the driver)
This makes the programming model easier -- one of
the functions can only be called before insertion
and can't fail, the other can fail.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9846078..dc74204 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -776,12 +776,10 @@
if (set & BIT(NL80211_STA_FLAG_AUTHENTICATED) &&
!test_sta_flag(sta, WLAN_STA_AUTH)) {
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTH);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTH);
if (ret)
return ret;
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_ASSOC);
+ ret = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
if (ret)
return ret;
}
@@ -789,11 +787,9 @@
if (mask & BIT(NL80211_STA_FLAG_AUTHORIZED)) {
if (set & BIT(NL80211_STA_FLAG_AUTHORIZED))
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTHORIZED);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
else if (test_sta_flag(sta, WLAN_STA_AUTHORIZED))
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_ASSOC);
+ ret = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
if (ret)
return ret;
}
@@ -805,12 +801,10 @@
if (!(set & BIT(NL80211_STA_FLAG_AUTHENTICATED)) &&
test_sta_flag(sta, WLAN_STA_AUTH)) {
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTH);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTH);
if (ret)
return ret;
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_NONE);
+ ret = sta_info_move_state(sta, IEEE80211_STA_NONE);
if (ret)
return ret;
}
@@ -944,8 +938,8 @@
if (!sta)
return -ENOMEM;
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
err = sta_apply_parameters(local, sta, params);
if (err) {
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 2406b3e..c838371 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -63,14 +63,15 @@
test_sta_flag(sta, WLAN_STA_##flg) ? #flg "\n" : ""
int res = scnprintf(buf, sizeof(buf),
- "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+ "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
TEST(AUTH), TEST(ASSOC), TEST(PS_STA),
TEST(PS_DRIVER), TEST(AUTHORIZED),
TEST(SHORT_PREAMBLE),
TEST(WME), TEST(WDS), TEST(CLEAR_PS_FILT),
TEST(MFP), TEST(BLOCK_BA), TEST(PSPOLL),
TEST(UAPSD), TEST(SP), TEST(TDLS_PEER),
- TEST(TDLS_PEER_AUTH));
+ TEST(TDLS_PEER_AUTH), TEST(4ADDR_EVENT),
+ TEST(INSERTED));
#undef TEST
return simple_read_from_buffer(userbuf, count, ppos, buf, res);
}
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index d38baa4..a98d370 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -265,9 +265,9 @@
addr, sdata->name);
#endif
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
rate_control_rate_init(sta);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index e47768c..6b0d70e 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -318,9 +318,9 @@
goto err_del_interface;
}
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
res = sta_info_insert(sta);
if (res) {
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 41ef1b4..bf92e28 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -96,9 +96,9 @@
if (!sta)
return NULL;
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
set_sta_flag(sta, WLAN_STA_WME);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index de3268c..acc11b5 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1587,10 +1587,19 @@
return false;
}
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- if (!(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ err = sta_info_move_state(sta, IEEE80211_STA_AUTH);
+ if (!err)
+ err = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
+ if (!err && !(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
+ err = sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ if (err) {
+ printk(KERN_DEBUG
+ "%s: failed to move station %pM to desired state\n",
+ sdata->name, sta->sta.addr);
+ WARN_ON(__sta_info_destroy(sta));
+ mutex_unlock(&sdata->local->sta_mtx);
+ return false;
+ }
rates = 0;
basic_rates = 0;
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f28fa02..df8f0a2 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -403,6 +403,8 @@
sta_info_hash_add(local, sta);
list_add(&sta->list, &local->sta_list);
+
+ set_sta_flag(sta, WLAN_STA_INSERTED);
} else {
sta->dummy = false;
}
@@ -707,7 +709,7 @@
return have_buffered;
}
-static int __must_check __sta_info_destroy(struct sta_info *sta)
+int __must_check __sta_info_destroy(struct sta_info *sta)
{
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
@@ -722,6 +724,8 @@
local = sta->local;
sdata = sta->sdata;
+ lockdep_assert_held(&local->sta_mtx);
+
/*
* Before removing the station from the driver and
* rate control, it might still start new aggregation
@@ -763,8 +767,13 @@
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
- while (sta->sta_state > IEEE80211_STA_NONE)
- sta_info_move_state(sta, sta->sta_state - 1);
+ while (sta->sta_state > IEEE80211_STA_NONE) {
+ int err = sta_info_move_state(sta, sta->sta_state - 1);
+ if (err) {
+ WARN_ON_ONCE(1);
+ break;
+ }
+ }
if (sta->uploaded) {
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
@@ -1391,8 +1400,8 @@
}
EXPORT_SYMBOL(ieee80211_sta_set_buffered);
-int sta_info_move_state_checked(struct sta_info *sta,
- enum ieee80211_sta_state new_state)
+int sta_info_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state)
{
might_sleep();
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 6f77f12..381de37 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -52,6 +52,7 @@
* @WLAN_STA_SP: Station is in a service period, so don't try to
* reply to other uAPSD trigger frames or PS-Poll.
* @WLAN_STA_4ADDR_EVENT: 4-addr event was already sent for this frame.
+ * @WLAN_STA_INSERTED: This station is inserted into the hash table.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH,
@@ -71,6 +72,7 @@
WLAN_STA_UAPSD,
WLAN_STA_SP,
WLAN_STA_4ADDR_EVENT,
+ WLAN_STA_INSERTED,
};
enum ieee80211_sta_state {
@@ -427,13 +429,17 @@
return test_and_set_bit(flag, &sta->_flags);
}
-int sta_info_move_state_checked(struct sta_info *sta,
- enum ieee80211_sta_state new_state);
+int sta_info_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state);
-static inline void sta_info_move_state(struct sta_info *sta,
- enum ieee80211_sta_state new_state)
+static inline void sta_info_pre_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state)
{
- int ret = sta_info_move_state_checked(sta, new_state);
+ int ret;
+
+ WARN_ON_ONCE(test_sta_flag(sta, WLAN_STA_INSERTED));
+
+ ret = sta_info_move_state(sta, new_state);
WARN_ON_ONCE(ret);
}
@@ -544,6 +550,7 @@
int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
int sta_info_reinsert(struct sta_info *sta);
+int __must_check __sta_info_destroy(struct sta_info *sta);
int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,