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mac80211: delay IBSS station insertion
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In order to notify drivers and simplify the station
management code, defer IBSS station insertion to a
work item and don't do it directly while receiving
a frame.

This increases the complexity in IBSS a little bit,
but it's pretty straight forward and it allows us
to reduce the station management complexity (next
patch) considerably.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Johannes Berg authored and John W. Linville committed Dec 15, 2011
1 parent 5654416 commit 8bf11d8
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Showing 4 changed files with 140 additions and 57 deletions.
154 changes: 122 additions & 32 deletions net/mac80211/ibss.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -275,6 +275,80 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
cbss->tsf);
}

static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
__acquires(RCU)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
u8 addr[ETH_ALEN];

memcpy(addr, sta->sta.addr, ETH_ALEN);

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
wiphy_debug(sdata->local->hw.wiphy,
"Adding new IBSS station %pM (dev=%s)\n",
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);

rate_control_rate_init(sta);

/* If it fails, maybe we raced another insertion? */
if (sta_info_insert_rcu(sta))
return sta_info_get(sdata, addr);
return sta;
}

static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr,
u32 supp_rates)
__acquires(RCU)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
int band = local->hw.conf.channel->band;

/*
* XXX: Consider removing the least recently used entry and
* allow new one to be added.
*/
if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
if (net_ratelimit())
printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
rcu_read_lock();
return NULL;
}

if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
rcu_read_lock();
return NULL;
}

if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) {
rcu_read_lock();
return NULL;
}

sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
if (!sta) {
rcu_read_lock();
return NULL;
}

sta->last_rx = jiffies;

/* make sure mandatory rates are always added */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);

return ieee80211_ibss_finish_sta(sta);
}

static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len,
Expand Down Expand Up @@ -334,10 +408,11 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
#endif
rates_updated = true;
}
} else
} else {
rcu_read_unlock();
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
mgmt->sa, supp_rates,
GFP_ATOMIC);
mgmt->sa, supp_rates);
}
}

if (sta && elems->wmm_info)
Expand Down Expand Up @@ -464,21 +539,17 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
ieee80211_sta_join_ibss(sdata, bss);
supp_rates = ieee80211_sta_get_rates(local, elems, band);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
supp_rates, GFP_KERNEL);
supp_rates);
rcu_read_unlock();
}

put_bss:
ieee80211_rx_bss_put(local, bss);
}

/*
* Add a new IBSS station, will also be called by the RX code when,
* in IBSS mode, receiving a frame from a yet-unknown station, hence
* must be callable in atomic context.
*/
struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
u8 *bssid, u8 *addr, u32 supp_rates,
gfp_t gfp)
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr,
u32 supp_rates)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
Expand All @@ -493,40 +564,29 @@ struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
if (net_ratelimit())
printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
return NULL;
return;
}

if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
return NULL;
return;

if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
return NULL;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
wiphy_debug(local->hw.wiphy, "Adding new IBSS station %pM (dev=%s)\n",
addr, sdata->name);
#endif
return;

sta = sta_info_alloc(sdata, addr, gfp);
sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
if (!sta)
return NULL;
return;

sta->last_rx = jiffies;

sta_info_move_state(sta, IEEE80211_STA_AUTH);
sta_info_move_state(sta, IEEE80211_STA_ASSOC);
sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);

/* make sure mandatory rates are always added */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);

rate_control_rate_init(sta);

/* If it fails, maybe we raced another insertion? */
if (sta_info_insert(sta))
return sta_info_get(sdata, addr);
return sta;
spin_lock(&ifibss->incomplete_lock);
list_add(&sta->list, &ifibss->incomplete_stations);
spin_unlock(&ifibss->incomplete_lock);
ieee80211_queue_work(&local->hw, &sdata->work);
}

static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
Expand Down Expand Up @@ -865,6 +925,7 @@ void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct sta_info *sta;

mutex_lock(&ifibss->mtx);

Expand All @@ -876,6 +937,19 @@ void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
if (!ifibss->ssid_len)
goto out;

spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);

ieee80211_ibss_finish_sta(sta);
rcu_read_unlock();
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);

switch (ifibss->state) {
case IEEE80211_IBSS_MLME_SEARCH:
ieee80211_sta_find_ibss(sdata);
Expand Down Expand Up @@ -934,6 +1008,8 @@ void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
setup_timer(&ifibss->timer, ieee80211_ibss_timer,
(unsigned long) sdata);
mutex_init(&ifibss->mtx);
INIT_LIST_HEAD(&ifibss->incomplete_stations);
spin_lock_init(&ifibss->incomplete_lock);
}

/* scan finished notification */
Expand Down Expand Up @@ -1053,6 +1129,7 @@ int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
struct cfg80211_bss *cbss;
u16 capability;
int active_ibss;
struct sta_info *sta;

mutex_lock(&sdata->u.ibss.mtx);

Expand Down Expand Up @@ -1081,6 +1158,19 @@ int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
}

sta_info_flush(sdata->local, sdata);

spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);

sta_info_free(local, sta);
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);

netif_carrier_off(sdata->dev);

/* remove beacon */
Expand Down
8 changes: 5 additions & 3 deletions net/mac80211/ieee80211_i.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -482,6 +482,9 @@ struct ieee80211_if_ibss {
struct sk_buff __rcu *presp;
struct sk_buff *skb;

spinlock_t incomplete_lock;
struct list_head incomplete_stations;

enum {
IEEE80211_IBSS_MLME_SEARCH,
IEEE80211_IBSS_MLME_JOINED,
Expand Down Expand Up @@ -1172,9 +1175,8 @@ void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata);
/* IBSS code */
void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local);
void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata);
struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
u8 *bssid, u8 *addr, u32 supp_rates,
gfp_t gfp);
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr, u32 supp_rates);
int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
struct cfg80211_ibss_params *params);
int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata);
Expand Down
4 changes: 2 additions & 2 deletions net/mac80211/rx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2775,8 +2775,8 @@ static int prepare_for_handlers(struct ieee80211_rx_data *rx,
rate_idx = 0; /* TODO: HT rates */
else
rate_idx = status->rate_idx;
rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
BIT(rate_idx));
}
break;
case NL80211_IFTYPE_MESH_POINT:
Expand Down
31 changes: 11 additions & 20 deletions net/mac80211/sta_info.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -354,35 +354,26 @@ static int sta_info_finish_insert(struct sta_info *sta,
/* notify driver */
err = drv_sta_add(local, sdata, &sta->sta);
if (err) {
if (!async)
if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
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 {
} 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);
#endif
}

sdata = sta->sdata;
}

if (!dummy_reinsert) {
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);
}
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);

list_add(&sta->list, &local->sta_list);
} else {
Expand Down Expand Up @@ -1546,7 +1537,7 @@ EXPORT_SYMBOL(ieee80211_sta_set_buffered);
int sta_info_move_state_checked(struct sta_info *sta,
enum ieee80211_sta_state new_state)
{
/* might_sleep(); -- for driver notify later, fix IBSS first */
might_sleep();

if (sta->sta_state == new_state)
return 0;
Expand Down

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