[PATCH] mac80211: ERP IE handling improvements

The "protection needed" flag is currently parsed out of the ERP IE in
beacons. This patch allows the ERP IE to be available at assocation time
and causes the appropriate actions to be performed earlier.

It is slightly complicated by the fact that most APs don't include the
ERP IE in association responses. To work around this, we store ERP
values in the ieee80211_sta_bss structure.

Also added some WLAN_ERP defines for use by upcoming patches.

Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index ecd61e8438a5132cb20116517858d4e84e05d1b7..272f8c8c90da609da135879020be6a7c3a582f4d 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -227,6 +227,17 @@ struct ieee80211_cts {
 #define WLAN_CAPABILITY_SHORT_SLOT_TIME        (1<<10)
 #define WLAN_CAPABILITY_DSSS_OFDM      (1<<13)
 
+/* 802.11g ERP information element */
+#define WLAN_ERP_NON_ERP_PRESENT (1<<0)
+#define WLAN_ERP_USE_PROTECTION (1<<1)
+#define WLAN_ERP_BARKER_PREAMBLE (1<<2)
+
+/* WLAN_ERP_BARKER_PREAMBLE values */
+enum {
+       WLAN_ERP_PREAMBLE_SHORT = 0,
+       WLAN_ERP_PREAMBLE_LONG = 1,
+};
+
 /* Status codes */
 enum ieee80211_statuscode {
        WLAN_STATUS_SUCCESS = 0,

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index b222a9afd4e9fb38e681212eb9cf0109e6d27b47..99ff7c5e920482761b95e0419e65bbf1ed61047c 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -99,6 +99,12 @@ struct ieee80211_sta_bss {
        int probe_resp;
        unsigned long last_update;
 
+       /* during assocation, we save an ERP value from a probe response so
+        * that we can feed ERP info to the driver when handling the
+        * association completes. these fields probably won't be up-to-date
+        * otherwise, you probably don't want to use them. */
+       int has_erp_value;
+       u8 erp_value;
 };
 
 

diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index f3ca83743b48fcce739f5b9064f6a1ef8263e3d8..df6c410de16179f25e5b4999bfeeb31a2e814f94 100644 (file)
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -314,6 +314,27 @@ static void ieee80211_sta_wmm_params(struct net_device *dev,
 }
 
 
+static void ieee80211_handle_erp_ie(struct net_device *dev, u8 erp_value)
+{
+       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+       struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+       int use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
+
+       if (use_protection != !!ifsta->use_protection) {
+               if (net_ratelimit()) {
+                       printk(KERN_DEBUG "%s: CTS protection %s (BSSID="
+                              MAC_FMT ")\n",
+                              dev->name,
+                              use_protection ? "enabled" : "disabled",
+                              MAC_ARG(ifsta->bssid));
+               }
+               ifsta->use_protection = use_protection ? 1 : 0;
+               local->cts_protect_erp_frames = use_protection;
+       }
+}
+
+
 static void ieee80211_sta_send_associnfo(struct net_device *dev,
                                         struct ieee80211_if_sta *ifsta)
 {
@@ -377,9 +398,18 @@ static void ieee80211_set_associated(struct net_device *dev,
 
        if (assoc) {
                struct ieee80211_sub_if_data *sdata;
+               struct ieee80211_sta_bss *bss;
                sdata = IEEE80211_DEV_TO_SUB_IF(dev);
                if (sdata->type != IEEE80211_IF_TYPE_STA)
                        return;
+
+               bss = ieee80211_rx_bss_get(dev, ifsta->bssid);
+               if (bss) {
+                       if (bss->has_erp_value)
+                               ieee80211_handle_erp_ie(dev, bss->erp_value);
+                       ieee80211_rx_bss_put(dev, bss);
+               }
+
                netif_carrier_on(dev);
                ifsta->prev_bssid_set = 1;
                memcpy(ifsta->prev_bssid, sdata->u.sta.bssid, ETH_ALEN);
@@ -1177,6 +1207,18 @@ static void ieee80211_rx_mgmt_assoc_resp(struct net_device *dev,
                return;
        }
 
+       /* it probably doesn't, but if the frame includes an ERP value then
+        * update our stored copy */
+       if (elems.erp_info && elems.erp_info_len >= 1) {
+               struct ieee80211_sta_bss *bss
+                       = ieee80211_rx_bss_get(dev, ifsta->bssid);
+               if (bss) {
+                       bss->erp_value = elems.erp_info[0];
+                       bss->has_erp_value = 1;
+                       ieee80211_rx_bss_put(dev, bss);
+               }
+       }
+
        printk(KERN_DEBUG "%s: associated\n", dev->name);
        ifsta->aid = aid;
        ifsta->ap_capab = capab_info;
@@ -1499,6 +1541,12 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
                return;
        }
 
+       /* save the ERP value so that it is available at association time */
+       if (elems.erp_info && elems.erp_info_len >= 1) {
+               bss->erp_value = elems.erp_info[0];
+               bss->has_erp_value = 1;
+       }
+
        bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int);
        bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info);
        if (elems.ssid && elems.ssid_len <= IEEE80211_MAX_SSID_LEN) {
@@ -1614,10 +1662,8 @@ static void ieee80211_rx_mgmt_beacon(struct net_device *dev,
                                     size_t len,
                                     struct ieee80211_rx_status *rx_status)
 {
-       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_if_sta *ifsta;
-       int use_protection;
        size_t baselen;
        struct ieee802_11_elems elems;
 
@@ -1641,23 +1687,8 @@ static void ieee80211_rx_mgmt_beacon(struct net_device *dev,
                                   &elems) == ParseFailed)
                return;
 
-       use_protection = 0;
-       if (elems.erp_info && elems.erp_info_len >= 1) {
-               use_protection =
-                       (elems.erp_info[0] & ERP_INFO_USE_PROTECTION) != 0;
-       }
-
-       if (use_protection != !!ifsta->use_protection) {
-               if (net_ratelimit()) {
-                       printk(KERN_DEBUG "%s: CTS protection %s (BSSID="
-                              MAC_FMT ")\n",
-                              dev->name,
-                              use_protection ? "enabled" : "disabled",
-                              MAC_ARG(ifsta->bssid));
-               }
-               ifsta->use_protection = use_protection ? 1 : 0;
-               local->cts_protect_erp_frames = use_protection;
-       }
+       if (elems.erp_info && elems.erp_info_len >= 1)
+               ieee80211_handle_erp_ie(dev, elems.erp_info[0]);
 
        if (elems.wmm_param && ifsta->wmm_enabled) {
                ieee80211_sta_wmm_params(dev, ifsta, elems.wmm_param,