From 83d5cc012441531ab0bf6f99881958e964e9cf11 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 12 Jan 2012 09:31:10 +0100 Subject: [PATCH] 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 Signed-off-by: John W. Linville --- net/mac80211/cfg.c | 22 ++++++++-------------- net/mac80211/debugfs_sta.c | 5 +++-- net/mac80211/ibss.c | 6 +++--- net/mac80211/iface.c | 6 +++--- net/mac80211/mesh_plink.c | 6 +++--- net/mac80211/mlme.c | 17 +++++++++++++---- net/mac80211/sta_info.c | 19 ++++++++++++++----- net/mac80211/sta_info.h | 17 ++++++++++++----- 8 files changed, 59 insertions(+), 39 deletions(-) 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 @@ static int sta_apply_parameters(struct ieee80211_local *local, 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 @@ static int sta_apply_parameters(struct ieee80211_local *local, 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 @@ static int sta_apply_parameters(struct ieee80211_local *local, 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 @@ static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev, 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 @@ static ssize_t sta_flags_read(struct file *file, char __user *userbuf, 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 @@ static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 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 @@ static int ieee80211_do_open(struct net_device *dev, bool coming_up) 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 @@ static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata, 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 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk, 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 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU) 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 @@ static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local, 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 @@ static int __must_check __sta_info_destroy(struct sta_info *sta) 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 @@ static int __must_check __sta_info_destroy(struct sta_info *sta) 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 @@ void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta, } 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 @@ enum ieee80211_sta_info_flags { WLAN_STA_UAPSD, WLAN_STA_SP, WLAN_STA_4ADDR_EVENT, + WLAN_STA_INSERTED, }; enum ieee80211_sta_state { @@ -427,13 +429,17 @@ static inline int test_and_set_sta_flag(struct sta_info *sta, 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(struct sta_info *sta); 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, -- 2.7.4