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mac80211: fix sta_info mesh timer bug

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I noticed a bug I introduced when mesh is enabled: sta_info_destroy()
will end up calling cancel_timer() on a timer that has never been
initialized because the timer is only initialized in mesh_plink_alloc(),
not in sta_info_alloc(). This patch moves the initialization of all mesh
related fields into sta_info_alloc(), adds a bit of sanity checking to
the cfg80211 handlers and sta_info_insert() and makes mesh_plink_alloc()
a static helper function that is only used from the mesh plink code.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg
2008-02-27 09:56:40 +01:00
committed by John W. Linville
parent dbbea6713d
commit 03e4497ebe
4 changed files with 37 additions and 42 deletions
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33
net/mac80211/sta_info.c
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@@ -31,13 +31,12 @@
* 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() or
* mesh_plink_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.
* 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.
*
* 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,
@@ -248,6 +247,12 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
#ifdef CONFIG_MAC80211_MESH
sta->plink_state = LISTEN;
spin_lock_init(&sta->plink_lock);
init_timer(&sta->plink_timer);
#endif
return sta;
}
@@ -258,7 +263,19 @@ int sta_info_insert(struct sta_info *sta)
unsigned long flags;
DECLARE_MAC_BUF(mac);
WARN_ON(!netif_running(sdata->dev));
/*
* 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)))
return -ENETDOWN;
if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0))
return -EINVAL;
if (WARN_ON(is_multicast_ether_addr(sta->addr)))
return -EINVAL;
spin_lock_irqsave(&local->sta_lock, flags);
/* check if STA exists already */