cfg80211: separate internal SME implementation

The current internal SME implementation in cfg80211 is
very mixed up with the MLME handling, which has been
causing issues for a long time. There are three things
that the implementation has to provide:
 * a basic SME implementation for nl80211's connect()
   call (for drivers implementing auth/assoc, which is
   really just mac80211) and wireless extensions
 * MLME events for the userspace SME
 * SME events (connected, disconnected etc.) for all
   different SME implementation possibilities (driver,
   cfg80211 and userspace)

To achieve these goals it isn't necessary to track the
software SME's connection status outside of it's state
(which is the part that caused many issues.) Instead,
track it only in the SME data (wdev->conn) and in the
general case only track whether the wdev is connected
or not (via wdev->current_bss.)

Also separate the internal implementation to not have
callbacks from the SME events, but rather call it from
the API functions that the driver (or rather mac80211)
calls. This separates the code better.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 60 insertions, 131 deletions

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 4b9c2be0d56d..a61a44bc6cf0 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -21,129 +21,85 @@
 void cfg80211_rx_assoc_resp(struct net_device *dev, struct cfg80211_bss *bss,
                             const u8 *buf, size_t len)
 {
-        u16 status_code;
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         struct wiphy *wiphy = wdev->wiphy;
         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)buf;
         u8 *ie = mgmt->u.assoc_resp.variable;
         int ieoffs = offsetof(struct ieee80211_mgmt, u.assoc_resp.variable);
+        u16 status_code = le16_to_cpu(mgmt->u.assoc_resp.status_code);
 
         trace_cfg80211_send_rx_assoc(dev, bss);
 
-        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)) {
+        if (cfg80211_sme_rx_assoc_resp(wdev, status_code)) {
                 cfg80211_put_bss(wiphy, bss);
                 return;
         }
 
         nl80211_send_rx_assoc(rdev, dev, buf, len, GFP_KERNEL);
-
-        if (status_code != WLAN_STATUS_SUCCESS && wdev->conn) {
-                cfg80211_sme_failed_assoc(wdev);
-                /*
-                 * do not call connect_result() now because the
-                 * sme will schedule work that does it later.
-                 */
-                cfg80211_put_bss(wiphy, bss);
-                return;
-        }
-
-        if (!wdev->conn && wdev->sme_state == CFG80211_SME_IDLE) {
-                /*
-                 * This is for the userspace SME, the CONNECTING
-                 * state will be changed to CONNECTED by
-                 * __cfg80211_connect_result() below.
-                 */
-                wdev->sme_state = CFG80211_SME_CONNECTING;
-        }
-
-        /* this consumes the bss reference */
+        /* update current_bss etc., consumes the bss reference */
         __cfg80211_connect_result(dev, mgmt->bssid, NULL, 0, ie, len - ieoffs,
                                   status_code,
                                   status_code == WLAN_STATUS_SUCCESS, bss);
 }
 EXPORT_SYMBOL(cfg80211_rx_assoc_resp);
 
-static void cfg80211_process_deauth(struct net_device *dev,
+static void cfg80211_process_auth(struct wireless_dev *wdev,
+                                  const u8 *buf, size_t len)
+{
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+
+        nl80211_send_rx_auth(rdev, wdev->netdev, buf, len, GFP_KERNEL);
+        cfg80211_sme_rx_auth(wdev, buf, len);
+}
+
+static void cfg80211_process_deauth(struct wireless_dev *wdev,
                                     const u8 *buf, size_t len)
 {
-        struct wireless_dev *wdev = dev->ieee80211_ptr;
-        struct wiphy *wiphy = wdev->wiphy;
-        struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)buf;
         const u8 *bssid = mgmt->bssid;
-        bool was_current = false;
-
-        if (wdev->current_bss &&
-            ether_addr_equal(wdev->current_bss->pub.bssid, bssid)) {
-                cfg80211_unhold_bss(wdev->current_bss);
-                cfg80211_put_bss(wiphy, &wdev->current_bss->pub);
-                wdev->current_bss = NULL;
-                was_current = true;
-        }
+        u16 reason_code = le16_to_cpu(mgmt->u.deauth.reason_code);
+        bool from_ap = !ether_addr_equal(mgmt->sa, wdev->netdev->dev_addr);
 
-        nl80211_send_deauth(rdev, dev, buf, len, GFP_KERNEL);
+        nl80211_send_deauth(rdev, wdev->netdev, buf, len, GFP_KERNEL);
 
-        if (wdev->sme_state == CFG80211_SME_CONNECTED && was_current) {
-                u16 reason_code;
-                bool from_ap;
-
-                reason_code = le16_to_cpu(mgmt->u.deauth.reason_code);
+        if (!wdev->current_bss ||
+            !ether_addr_equal(wdev->current_bss->pub.bssid, bssid))
+                return;
 
-                from_ap = !ether_addr_equal(mgmt->sa, dev->dev_addr);
-                __cfg80211_disconnected(dev, NULL, 0, reason_code, from_ap);
-        } else if (wdev->sme_state == CFG80211_SME_CONNECTING) {
-                __cfg80211_connect_result(dev, mgmt->bssid, NULL, 0, NULL, 0,
-                                          WLAN_STATUS_UNSPECIFIED_FAILURE,
-                                          false, NULL);
-        }
+        __cfg80211_disconnected(wdev->netdev, NULL, 0, reason_code, from_ap);
+        cfg80211_sme_deauth(wdev);
 }
 
-static void cfg80211_process_disassoc(struct net_device *dev,
+static void cfg80211_process_disassoc(struct wireless_dev *wdev,
                                       const u8 *buf, size_t len)
 {
-        struct wireless_dev *wdev = dev->ieee80211_ptr;
-        struct wiphy *wiphy = wdev->wiphy;
-        struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)buf;
         const u8 *bssid = mgmt->bssid;
-        u16 reason_code;
-        bool from_ap;
+        u16 reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code);
+        bool from_ap = !ether_addr_equal(mgmt->sa, wdev->netdev->dev_addr);
 
-        nl80211_send_disassoc(rdev, dev, buf, len, GFP_KERNEL);
+        nl80211_send_disassoc(rdev, wdev->netdev, buf, len, GFP_KERNEL);
 
-        if (wdev->sme_state != CFG80211_SME_CONNECTED)
+        if (WARN_ON(!wdev->current_bss ||
+                    !ether_addr_equal(wdev->current_bss->pub.bssid, bssid)))
                 return;
 
-        if (wdev->current_bss &&
-            ether_addr_equal(wdev->current_bss->pub.bssid, bssid)) {
-                cfg80211_sme_disassoc(dev, wdev->current_bss);
-                cfg80211_unhold_bss(wdev->current_bss);
-                cfg80211_put_bss(wiphy, &wdev->current_bss->pub);
-                wdev->current_bss = NULL;
-        } else
-                WARN_ON(1);
-
-        reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code);
-
-        from_ap = !ether_addr_equal(mgmt->sa, dev->dev_addr);
-        __cfg80211_disconnected(dev, NULL, 0, reason_code, from_ap);
+        __cfg80211_disconnected(wdev->netdev, NULL, 0, reason_code, from_ap);
+        cfg80211_sme_disassoc(wdev);
 }
 
 void cfg80211_rx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
-        struct wiphy *wiphy = wdev->wiphy;
-        struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
         struct ieee80211_mgmt *mgmt = (void *)buf;
 
         ASSERT_WDEV_LOCK(wdev);
@@ -153,14 +109,12 @@ void cfg80211_rx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len)
         if (WARN_ON(len < 2))
                 return;
 
-        if (ieee80211_is_auth(mgmt->frame_control)) {
-                nl80211_send_rx_auth(rdev, dev, buf, len, GFP_KERNEL);
-                cfg80211_sme_rx_auth(dev, buf, len);
-        } else if (ieee80211_is_deauth(mgmt->frame_control)) {
-                cfg80211_process_deauth(dev, buf, len);
-        } else if (ieee80211_is_disassoc(mgmt->frame_control)) {
-                cfg80211_process_disassoc(dev, buf, len);
-        }
+        if (ieee80211_is_auth(mgmt->frame_control))
+                cfg80211_process_auth(wdev, buf, len);
+        else if (ieee80211_is_deauth(mgmt->frame_control))
+                cfg80211_process_deauth(wdev, buf, len);
+        else if (ieee80211_is_disassoc(mgmt->frame_control))
+                cfg80211_process_disassoc(wdev, buf, len);
 }
 EXPORT_SYMBOL(cfg80211_rx_mlme_mgmt);
 
@@ -173,10 +127,7 @@ void cfg80211_auth_timeout(struct net_device *dev, const u8 *addr)
         trace_cfg80211_send_auth_timeout(dev, addr);
 
         nl80211_send_auth_timeout(rdev, dev, addr, GFP_KERNEL);
-        if (wdev->sme_state == CFG80211_SME_CONNECTING)
-                __cfg80211_connect_result(dev, addr, NULL, 0, NULL, 0,
-                                          WLAN_STATUS_UNSPECIFIED_FAILURE,
-                                          false, NULL);
+        cfg80211_sme_auth_timeout(wdev);
 }
 EXPORT_SYMBOL(cfg80211_auth_timeout);
 
@@ -189,10 +140,7 @@ void cfg80211_assoc_timeout(struct net_device *dev, const u8 *addr)
         trace_cfg80211_send_assoc_timeout(dev, addr);
 
         nl80211_send_assoc_timeout(rdev, dev, addr, GFP_KERNEL);
-        if (wdev->sme_state == CFG80211_SME_CONNECTING)
-                __cfg80211_connect_result(dev, addr, NULL, 0, NULL, 0,
-                                          WLAN_STATUS_UNSPECIFIED_FAILURE,
-                                          false, NULL);
+        cfg80211_sme_assoc_timeout(wdev);
 }
 EXPORT_SYMBOL(cfg80211_assoc_timeout);
 
@@ -209,9 +157,9 @@ void cfg80211_tx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len)
                 return;
 
         if (ieee80211_is_deauth(mgmt->frame_control))
-                cfg80211_process_deauth(dev, buf, len);
+                cfg80211_process_deauth(wdev, buf, len);
         else
-                cfg80211_process_disassoc(dev, buf, len);
+                cfg80211_process_disassoc(wdev, buf, len);
 }
 EXPORT_SYMBOL(cfg80211_tx_mlme_mgmt);
 
@@ -336,21 +284,12 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         int err;
-        bool was_connected = false;
 
         ASSERT_WDEV_LOCK(wdev);
 
-        if (wdev->current_bss && req->prev_bssid &&
-            ether_addr_equal(wdev->current_bss->pub.bssid, req->prev_bssid)) {
-                /*
-                 * Trying to reassociate: Allow this to proceed and let the old
-                 * association to be dropped when the new one is completed.
-                 */
-                if (wdev->sme_state == CFG80211_SME_CONNECTED) {
-                        was_connected = true;
-                        wdev->sme_state = CFG80211_SME_CONNECTING;
-                }
-        } else if (wdev->current_bss)
+        if (wdev->current_bss &&
+            (!req->prev_bssid || !ether_addr_equal(wdev->current_bss->pub.bssid,
+                                                   req->prev_bssid)))
                 return -EALREADY;
 
         cfg80211_oper_and_ht_capa(&req->ht_capa_mask,
@@ -360,11 +299,8 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 
         req->bss = cfg80211_get_bss(&rdev->wiphy, chan, bssid, ssid, ssid_len,
                                     WLAN_CAPABILITY_ESS, WLAN_CAPABILITY_ESS);
-        if (!req->bss) {
-                if (was_connected)
-                        wdev->sme_state = CFG80211_SME_CONNECTED;
+        if (!req->bss)
                 return -ENOENT;
-        }
 
         err = cfg80211_can_use_chan(rdev, wdev, chan, CHAN_MODE_SHARED);
         if (err)
@@ -373,11 +309,8 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
         err = rdev_assoc(rdev, dev, req);
 
 out:
-        if (err) {
-                if (was_connected)
-                        wdev->sme_state = CFG80211_SME_CONNECTED;
+        if (err)
                 cfg80211_put_bss(&rdev->wiphy, req->bss);
-        }
 
         return err;
 }
@@ -398,8 +331,9 @@ int cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
 
         ASSERT_WDEV_LOCK(wdev);
 
-        if (local_state_change && (!wdev->current_bss ||
-            !ether_addr_equal(wdev->current_bss->pub.bssid, bssid)))
+        if (local_state_change &&
+            (!wdev->current_bss ||
+             !ether_addr_equal(wdev->current_bss->pub.bssid, bssid)))
                 return 0;
 
         return rdev_deauth(rdev, dev, &req);
@@ -417,13 +351,11 @@ int cfg80211_mlme_disassoc(struct cfg80211_registered_device *rdev,
                 .ie = ie,
                 .ie_len = ie_len,
         };
+        int err;
 
         ASSERT_WDEV_LOCK(wdev);
 
-        if (wdev->sme_state != CFG80211_SME_CONNECTED)
-                return -ENOTCONN;
-
-        if (WARN(!wdev->current_bss, "sme_state=%d\n", wdev->sme_state))
+        if (!wdev->current_bss)
                 return -ENOTCONN;
 
         if (ether_addr_equal(wdev->current_bss->pub.bssid, bssid))
@@ -431,7 +363,13 @@ int cfg80211_mlme_disassoc(struct cfg80211_registered_device *rdev,
         else
                 return -ENOTCONN;
 
-        return rdev_disassoc(rdev, dev, &req);
+        err = rdev_disassoc(rdev, dev, &req);
+        if (err)
+                return err;
+
+        /* driver should have reported the disassoc */
+        WARN_ON(wdev->current_bss);
+        return 0;
 }
 
 void cfg80211_mlme_down(struct cfg80211_registered_device *rdev,
@@ -439,10 +377,6 @@ void cfg80211_mlme_down(struct cfg80211_registered_device *rdev,
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         u8 bssid[ETH_ALEN];
-        struct cfg80211_deauth_request req = {
-                .reason_code = WLAN_REASON_DEAUTH_LEAVING,
-                .bssid = bssid,
-        };
 
         ASSERT_WDEV_LOCK(wdev);
 
@@ -453,13 +387,8 @@ void cfg80211_mlme_down(struct cfg80211_registered_device *rdev,
                 return;
 
         memcpy(bssid, wdev->current_bss->pub.bssid, ETH_ALEN);
-        rdev_deauth(rdev, dev, &req);
-
-        if (wdev->current_bss) {
-                cfg80211_unhold_bss(wdev->current_bss);
-                cfg80211_put_bss(&rdev->wiphy, &wdev->current_bss->pub);
-                wdev->current_bss = NULL;
-        }
+        cfg80211_mlme_deauth(rdev, dev, bssid, NULL, 0,
+                             WLAN_REASON_DEAUTH_LEAVING, false);
 }
 
 struct cfg80211_mgmt_registration {