cfg80211: use reassociation when possible

With the move of everything related to the SME from
mac80211 to cfg80211, we lost the ability to send
reassociation frames. This adds them back, but only
for wireless extensions. With the userspace SME, it
shall control assoc vs. reassoc (it already can do
so with the nl80211 interface).

I haven't touched the connect() implementation, so
it is not possible to reassociate with the nl80211
connect primitive. I think that should be done with
the NL80211_CMD_ROAM command, but we'll have to see
how that can be handled in the future, especially
with fullmac chips.

This patch addresses only the immediate regression
we had in mac80211, which previously sent reassoc.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 64df51d9a89fdd722e9fda6cd1c3e484dbd94052..1ee30fcd6fdcbc64489add2ac73c4f67504e8ced 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1335,10 +1335,10 @@ struct wireless_dev {
                struct cfg80211_cached_keys *keys;
                u8 *ie;
                size_t ie_len;
-               u8 bssid[ETH_ALEN];
+               u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
                u8 ssid[IEEE80211_MAX_SSID_LEN];
                s8 default_key, default_mgmt_key;
-               bool ps;
+               bool ps, prev_bssid_valid;
                int ps_timeout;
        } wext;
 #endif

diff --git a/net/wireless/core.h b/net/wireless/core.h
index 5696b95af9bedcee7cdd0175efd0807eacacf7ca..92e0492b0e4db454f5ad2569925ac69d500f942e 100644 (file)
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -335,7 +335,8 @@ void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
 int __cfg80211_connect(struct cfg80211_registered_device *rdev,
                       struct net_device *dev,
                       struct cfg80211_connect_params *connect,
-                      struct cfg80211_cached_keys *connkeys);
+                      struct cfg80211_cached_keys *connkeys,
+                      const u8 *prev_bssid);
 int cfg80211_connect(struct cfg80211_registered_device *rdev,
                     struct net_device *dev,
                     struct cfg80211_connect_params *connect,
@@ -353,6 +354,7 @@ int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
                              struct wireless_dev *wdev);
 
 void cfg80211_conn_work(struct work_struct *work);
+bool cfg80211_sme_failed_reassoc(struct wireless_dev *wdev);
 
 /* internal helpers */
 int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 51d5df67c632825b27d127efceb541c984a69585..da64071ceb84fa9a4dc83747804aea6b0bc02175 100644 (file)
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -67,6 +67,16 @@ void cfg80211_send_rx_assoc(struct net_device *dev, const u8 *buf, size_t len)
 
        status_code = le16_to_cpu(mgmt->u.assoc_resp.status_code);
 
+       /*
+        * This is a bit of a hack, we don't notify userspace of
+        * a (re-)association reply if we tried to send a reassoc
+        * and got a reject -- we only try again with an assoc
+        * frame instead of reassoc.
+        */
+       if (status_code != WLAN_STATUS_SUCCESS && wdev->conn &&
+           cfg80211_sme_failed_reassoc(wdev))
+               goto out;
+
        nl80211_send_rx_assoc(rdev, dev, buf, len, GFP_KERNEL);
 
        if (status_code == WLAN_STATUS_SUCCESS) {
@@ -97,6 +107,7 @@ void cfg80211_send_rx_assoc(struct net_device *dev, const u8 *buf, size_t len)
                cfg80211_put_bss(&bss->pub);
        }
 
+ out:
        wdev_unlock(wdev);
 }
 EXPORT_SYMBOL(cfg80211_send_rx_assoc);

diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 219c3bc2c37d3c1a3bf88a0b5aae1b11751d2602..104b33e34d22bc0f9a2e71b80d2300a148eb5857 100644 (file)
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -27,10 +27,10 @@ struct cfg80211_conn {
                CFG80211_CONN_ASSOCIATE_NEXT,
                CFG80211_CONN_ASSOCIATING,
        } state;
-       u8 bssid[ETH_ALEN];
+       u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
        u8 *ie;
        size_t ie_len;
-       bool auto_auth;
+       bool auto_auth, prev_bssid_valid;
 };
 
 
@@ -110,6 +110,7 @@ static int cfg80211_conn_do_work(struct wireless_dev *wdev)
 {
        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
        struct cfg80211_connect_params *params;
+       const u8 *prev_bssid = NULL;
        int err;
 
        ASSERT_WDEV_LOCK(wdev);
@@ -135,15 +136,11 @@ static int cfg80211_conn_do_work(struct wireless_dev *wdev)
        case CFG80211_CONN_ASSOCIATE_NEXT:
                BUG_ON(!rdev->ops->assoc);
                wdev->conn->state = CFG80211_CONN_ASSOCIATING;
-               /*
-                * We could, later, implement roaming here and then actually
-                * set prev_bssid to non-NULL. But then we need to be aware
-                * that some APs don't like that -- so we'd need to retry
-                * the association.
-                */
+               if (wdev->conn->prev_bssid_valid)
+                       prev_bssid = wdev->conn->prev_bssid;
                err = __cfg80211_mlme_assoc(rdev, wdev->netdev,
                                            params->channel, params->bssid,
-                                           NULL,
+                                           prev_bssid,
                                            params->ssid, params->ssid_len,
                                            params->ie, params->ie_len,
                                            false, &params->crypto);
@@ -316,6 +313,28 @@ void cfg80211_sme_rx_auth(struct net_device *dev,
        }
 }
 
+bool cfg80211_sme_failed_reassoc(struct wireless_dev *wdev)
+{
+       struct wiphy *wiphy = wdev->wiphy;
+       struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+
+       if (WARN_ON(!wdev->conn))
+               return false;
+
+       if (!wdev->conn->prev_bssid_valid)
+               return false;
+
+       /*
+        * Some stupid APs don't accept reassoc, so we
+        * need to fall back to trying regular assoc.
+        */
+       wdev->conn->prev_bssid_valid = false;
+       wdev->conn->state = CFG80211_CONN_ASSOCIATE_NEXT;
+       schedule_work(&rdev->conn_work);
+
+       return true;
+}
+
 void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
                               const u8 *req_ie, size_t req_ie_len,
                               const u8 *resp_ie, size_t resp_ie_len,
@@ -359,8 +378,11 @@ void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
 
                memset(&wrqu, 0, sizeof(wrqu));
                wrqu.ap_addr.sa_family = ARPHRD_ETHER;
-               if (bssid && status == WLAN_STATUS_SUCCESS)
+               if (bssid && status == WLAN_STATUS_SUCCESS) {
                        memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
+                       memcpy(wdev->wext.prev_bssid, bssid, ETH_ALEN);
+                       wdev->wext.prev_bssid_valid = true;
+               }
                wireless_send_event(dev, SIOCGIWAP, &wrqu, NULL);
        }
 #endif
@@ -511,6 +533,8 @@ void __cfg80211_roamed(struct wireless_dev *wdev, const u8 *bssid,
        memset(&wrqu, 0, sizeof(wrqu));
        wrqu.ap_addr.sa_family = ARPHRD_ETHER;
        memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
+       memcpy(wdev->wext.prev_bssid, bssid, ETH_ALEN);
+       wdev->wext.prev_bssid_valid = true;
        wireless_send_event(wdev->netdev, SIOCGIWAP, &wrqu, NULL);
 #endif
 }
@@ -643,7 +667,8 @@ EXPORT_SYMBOL(cfg80211_disconnected);
 int __cfg80211_connect(struct cfg80211_registered_device *rdev,
                       struct net_device *dev,
                       struct cfg80211_connect_params *connect,
-                      struct cfg80211_cached_keys *connkeys)
+                      struct cfg80211_cached_keys *connkeys,
+                      const u8 *prev_bssid)
 {
        struct wireless_dev *wdev = dev->ieee80211_ptr;
        struct ieee80211_channel *chan;
@@ -742,6 +767,11 @@ int __cfg80211_connect(struct cfg80211_registered_device *rdev,
                wdev->sme_state = CFG80211_SME_CONNECTING;
                wdev->connect_keys = connkeys;
 
+               if (prev_bssid) {
+                       memcpy(wdev->conn->prev_bssid, prev_bssid, ETH_ALEN);
+                       wdev->conn->prev_bssid_valid = true;
+               }
+
                /* we're good if we have both BSSID and channel */
                if (wdev->conn->params.bssid && wdev->conn->params.channel) {
                        wdev->conn->state = CFG80211_CONN_AUTHENTICATE_NEXT;
@@ -794,7 +824,7 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
 
        mutex_lock(&rdev->devlist_mtx);
        wdev_lock(dev->ieee80211_ptr);
-       err = __cfg80211_connect(rdev, dev, connect, connkeys);
+       err = __cfg80211_connect(rdev, dev, connect, connkeys, NULL);
        wdev_unlock(dev->ieee80211_ptr);
        mutex_unlock(&rdev->devlist_mtx);
 

diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index fe1a536391226acf727625aa8dba2be76f01497a..907470063f22a042f9dc7082369b432f422b92a7 100644 (file)
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -15,6 +15,7 @@ int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
                              struct wireless_dev *wdev)
 {
        struct cfg80211_cached_keys *ck = NULL;
+       const u8 *prev_bssid = NULL;
        int err, i;
 
        ASSERT_RDEV_LOCK(rdev);
@@ -42,8 +43,12 @@ int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
                for (i = 0; i < 6; i++)
                        ck->params[i].key = ck->data[i];
        }
+
+       if (wdev->wext.prev_bssid_valid)
+               prev_bssid = wdev->wext.prev_bssid;
+
        err = __cfg80211_connect(rdev, wdev->netdev,
-                                &wdev->wext.connect, ck);
+                                &wdev->wext.connect, ck, prev_bssid);
        if (err)
                kfree(ck);
 
@@ -184,6 +189,7 @@ int cfg80211_mgd_wext_siwessid(struct net_device *dev,
                        goto out;
        }
 
+       wdev->wext.prev_bssid_valid = false;
        wdev->wext.connect.ssid = wdev->wext.ssid;
        memcpy(wdev->wext.ssid, ssid, len);
        wdev->wext.connect.ssid_len = len;