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@xxxxxxxxxxxxxxxx>
Cc: Luis Carlos Cobo <luisca@xxxxxxxxxxx>
---
net/mac80211/cfg.c | 13 +++++++------
net/mac80211/mesh.h | 2 --
net/mac80211/mesh_plink.c | 31 +++++--------------------------
net/mac80211/sta_info.c | 33 +++++++++++++++++++++++++--------
4 files changed, 37 insertions(+), 42 deletions(-)
--- everything.orig/net/mac80211/cfg.c 2008-02-27 09:33:30.000000000 +0100
+++ everything/net/mac80211/cfg.c 2008-02-27 09:39:33.000000000 +0100
@@ -17,8 +17,6 @@
#include "ieee80211_rate.h"
#include "mesh.h"
-#define DEFAULT_RATES 0
-
static enum ieee80211_if_types
nl80211_type_to_mac80211_type(enum nl80211_iftype type)
{
@@ -660,10 +658,13 @@ static int ieee80211_add_station(struct
} else
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- if (ieee80211_vif_is_mesh(&sdata->vif))
- sta = mesh_plink_alloc(sdata, mac, DEFAULT_RATES, GFP_KERNEL);
- else
- sta = sta_info_alloc(sdata, mac, GFP_KERNEL);
+ if (compare_ether_addr(mac, dev->dev_addr) == 0)
+ return -EINVAL;
+
+ if (is_multicast_ether_addr(mac))
+ return -EINVAL;
+
+ sta = sta_info_alloc(sdata, mac, GFP_KERNEL);
if (!sta)
return -ENOMEM;
--- everything.orig/net/mac80211/mesh.h 2008-02-27 09:33:43.000000000 +0100
+++ everything/net/mac80211/mesh.h 2008-02-27 09:33:45.000000000 +0100
@@ -232,8 +232,6 @@ void mesh_neighbour_update(u8 *hw_addr,
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie,
struct net_device *dev);
void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
-struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
- u8 *hw_addr, u64 rates, gfp_t gfp);
void mesh_plink_broken(struct sta_info *sta);
void mesh_plink_deactivate(struct sta_info *sta);
int mesh_plink_open(struct sta_info *sta);
--- everything.orig/net/mac80211/sta_info.c 2008-02-27 09:34:33.000000000 +0100
+++ everything/net/mac80211/sta_info.c 2008-02-27 09:51:13.000000000 +0100
@@ -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,
@@ -244,6 +243,12 @@ struct sta_info *sta_info_alloc(struct i
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;
}
@@ -254,7 +259,19 @@ 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 */
--- everything.orig/net/mac80211/mesh_plink.c 2008-02-27 09:35:20.000000000 +0100
+++ everything/net/mac80211/mesh_plink.c 2008-02-27 09:44:36.000000000 +0100
@@ -88,40 +88,19 @@ static inline void mesh_plink_fsm_restar
sta->llid = sta->plid = sta->reason = sta->plink_retries = 0;
}
-/**
- * mesh_plink_alloc - allocate a new mesh peer link
- *
- * @sdata: local mesh interface
- * @hw_addr: hardware address (ETH_ALEN length)
- * @rates: rates the mesh peer supports
- *
- * The initial state of the new plink is set to LISTEN
- *
- * Returns: NULL on error.
- */
-struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
- u8 *hw_addr, u64 rates, gfp_t gfp)
+static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
+ u8 *hw_addr, u64 rates)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
- if (compare_ether_addr(hw_addr, sdata->dev->dev_addr) == 0)
- /* never add ourselves as neighbours */
- return NULL;
-
- if (is_multicast_ether_addr(hw_addr))
- return NULL;
-
if (local->num_sta >= MESH_MAX_PLINKS)
return NULL;
- sta = sta_info_alloc(sdata, hw_addr, gfp);
+ sta = sta_info_alloc(sdata, hw_addr, GFP_ATOMIC);
if (!sta)
return NULL;
- sta->plink_state = LISTEN;
- spin_lock_init(&sta->plink_lock);
- init_timer(&sta->plink_timer);
sta->flags |= WLAN_STA_AUTHORIZED;
sta->supp_rates[local->hw.conf.channel->band] = rates;
@@ -249,7 +228,7 @@ void mesh_neighbour_update(u8 *hw_addr,
sta = sta_info_get(local, hw_addr);
if (!sta) {
- sta = mesh_plink_alloc(sdata, hw_addr, rates, GFP_ATOMIC);
+ sta = mesh_plink_alloc(sdata, hw_addr, rates);
if (!sta) {
rcu_read_unlock();
return;
@@ -518,7 +497,7 @@ void mesh_rx_plink_frame(struct net_devi
}
rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
- sta = mesh_plink_alloc(sdata, mgmt->sa, rates, GFP_ATOMIC);
+ sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
if (!sta) {
mpl_dbg("Mesh plink error: plink table full\n");
rcu_read_unlock();
-
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