cfg80211: clean up mesh plink station change API

Make the ability to leave the plink_state unchanged not use a
magic -1 variable that isn't in the enum, but an explicit change
flag; reject invalid plink states or actions and move the needed
constants for plink actions to the right header file. Also
reject plink_state changes for non-mesh interfaces.

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

4 files changed, 54 insertions, 24 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index d581c6de5d64..9b54574c3df9 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -611,22 +611,10 @@ struct cfg80211_ap_settings {
 };
 
 /**
- * enum plink_action - actions to perform in mesh peers
- *
- * @PLINK_ACTION_INVALID: action 0 is reserved
- * @PLINK_ACTION_OPEN: start mesh peer link establishment
- * @PLINK_ACTION_BLOCK: block traffic from this mesh peer
- */
-enum plink_actions {
-        PLINK_ACTION_INVALID,
-        PLINK_ACTION_OPEN,
-        PLINK_ACTION_BLOCK,
-};
-
-/**
  * enum station_parameters_apply_mask - station parameter values to apply
  * @STATION_PARAM_APPLY_UAPSD: apply new uAPSD parameters (uapsd_queues, max_sp)
  * @STATION_PARAM_APPLY_CAPABILITY: apply new capability
+ * @STATION_PARAM_APPLY_PLINK_STATE: apply new plink state
  *
  * Not all station parameters have in-band "no change" signalling,
  * for those that don't these flags will are used.
@@ -634,6 +622,7 @@ enum plink_actions {
 enum station_parameters_apply_mask {
         STATION_PARAM_APPLY_UAPSD = BIT(0),
         STATION_PARAM_APPLY_CAPABILITY = BIT(1),
+        STATION_PARAM_APPLY_PLINK_STATE = BIT(2),
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c46bb016f4e4..7dcc69f73d2c 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -884,7 +884,8 @@ enum nl80211_commands {
  *      consisting of a nested array.
  *
  * @NL80211_ATTR_MESH_ID: mesh id (1-32 bytes).
- * @NL80211_ATTR_STA_PLINK_ACTION: action to perform on the mesh peer link.
+ * @NL80211_ATTR_STA_PLINK_ACTION: action to perform on the mesh peer link
+ *      (see &enum nl80211_plink_action).
  * @NL80211_ATTR_MPATH_NEXT_HOP: MAC address of the next hop for a mesh path.
  * @NL80211_ATTR_MPATH_INFO: information about a mesh_path, part of mesh path
  *      info given for %NL80211_CMD_GET_MPATH, nested attribute described at
@@ -3307,6 +3308,23 @@ enum nl80211_plink_state {
         MAX_NL80211_PLINK_STATES = NUM_NL80211_PLINK_STATES - 1
 };
 
+/**
+ * enum nl80211_plink_action - actions to perform in mesh peers
+ *
+ * @NL80211_PLINK_ACTION_NO_ACTION: perform no action
+ * @NL80211_PLINK_ACTION_OPEN: start mesh peer link establishment
+ * @NL80211_PLINK_ACTION_BLOCK: block traffic from this mesh peer
+ * @NUM_NL80211_PLINK_ACTIONS: number of possible actions
+ */
+enum plink_actions {
+        NL80211_PLINK_ACTION_NO_ACTION,
+        NL80211_PLINK_ACTION_OPEN,
+        NL80211_PLINK_ACTION_BLOCK,
+
+        NUM_NL80211_PLINK_ACTIONS,
+};
+
+
 #define NL80211_KCK_LEN                 16
 #define NL80211_KEK_LEN                 16
 #define NL80211_REPLAY_CTR_LEN          8
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index fb306814576a..ca28405d5f65 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1261,7 +1261,9 @@ static int sta_apply_parameters(struct ieee80211_local *local,
         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 #ifdef CONFIG_MAC80211_MESH
                 u32 changed = 0;
-                if (sdata->u.mesh.security & IEEE80211_MESH_SEC_SECURED) {
+                if (sdata->u.mesh.security & IEEE80211_MESH_SEC_SECURED &&
+                    (params->sta_modify_mask &
+                                        STATION_PARAM_APPLY_PLINK_STATE)) {
                         switch (params->plink_state) {
                         case NL80211_PLINK_ESTAB:
                                 if (sta->plink_state != NL80211_PLINK_ESTAB)
@@ -1292,12 +1294,18 @@ static int sta_apply_parameters(struct ieee80211_local *local,
                                 /*  nothing  */
                                 break;
                         }
+                } else if (params->sta_modify_mask &
+                                        STATION_PARAM_APPLY_PLINK_STATE) {
+                        return -EINVAL;
                 } else {
                         switch (params->plink_action) {
-                        case PLINK_ACTION_OPEN:
+                        case NL80211_PLINK_ACTION_NO_ACTION:
+                                /* nothing */
+                                break;
+                        case NL80211_PLINK_ACTION_OPEN:
                                 changed |= mesh_plink_open(sta);
                                 break;
-                        case PLINK_ACTION_BLOCK:
+                        case NL80211_PLINK_ACTION_BLOCK:
                                 changed |= mesh_plink_block(sta);
                                 break;
                         }
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d44ab216c0ec..9e7ece0e5e5e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3412,7 +3412,6 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
         memset(&params, 0, sizeof(params));
 
         params.listen_interval = -1;
-        params.plink_state = -1;
 
         if (info->attrs[NL80211_ATTR_STA_AID])
                 return -EINVAL;
@@ -3451,13 +3450,20 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
         if (parse_station_flags(info, dev->ieee80211_ptr->iftype, &params))
                 return -EINVAL;
 
-        if (info->attrs[NL80211_ATTR_STA_PLINK_ACTION])
+        if (info->attrs[NL80211_ATTR_STA_PLINK_ACTION]) {
                 params.plink_action =
-                    nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_ACTION]);
+                        nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_ACTION]);
+                if (params.plink_action >= NUM_NL80211_PLINK_ACTIONS)
+                        return -EINVAL;
+        }
 
-        if (info->attrs[NL80211_ATTR_STA_PLINK_STATE])
+        if (info->attrs[NL80211_ATTR_STA_PLINK_STATE]) {
                 params.plink_state =
-                    nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_STATE]);
+                        nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_STATE]);
+                if (params.plink_state >= NUM_NL80211_PLINK_STATES)
+                        return -EINVAL;
+                params.sta_modify_mask |= STATION_PARAM_APPLY_PLINK_STATE;
+        }
 
         if (info->attrs[NL80211_ATTR_LOCAL_MESH_POWER_MODE]) {
                 enum nl80211_mesh_power_mode pm = nla_get_u32(
@@ -3479,6 +3485,8 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                         return -EINVAL;
                 if (params.local_pm)
                         return -EINVAL;
+                if (params.sta_modify_mask & STATION_PARAM_APPLY_PLINK_STATE)
+                        return -EINVAL;
 
                 /* TDLS can't be set, ... */
                 if (params.sta_flags_set & BIT(NL80211_STA_FLAG_TDLS_PEER))
@@ -3542,6 +3550,8 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                         return -EINVAL;
                 if (params.local_pm)
                         return -EINVAL;
+                if (params.sta_modify_mask & STATION_PARAM_APPLY_PLINK_STATE)
+                        return -EINVAL;
                 /* reject any changes other than AUTHORIZED or WME (for TDLS) */
                 if (params.sta_flags_mask & ~(BIT(NL80211_STA_FLAG_AUTHORIZED) |
                                               BIT(NL80211_STA_FLAG_WME)))
@@ -3553,6 +3563,8 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                         return -EINVAL;
                 if (params.local_pm)
                         return -EINVAL;
+                if (params.sta_modify_mask & STATION_PARAM_APPLY_PLINK_STATE)
+                        return -EINVAL;
                 if (info->attrs[NL80211_ATTR_HT_CAPABILITY] ||
                     info->attrs[NL80211_ATTR_VHT_CAPABILITY])
                         return -EINVAL;
@@ -3652,9 +3664,12 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
                 params.vht_capa =
                         nla_data(info->attrs[NL80211_ATTR_VHT_CAPABILITY]);
 
-        if (info->attrs[NL80211_ATTR_STA_PLINK_ACTION])
+        if (info->attrs[NL80211_ATTR_STA_PLINK_ACTION]) {
                 params.plink_action =
-                    nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_ACTION]);
+                        nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_ACTION]);
+                if (params.plink_action >= NUM_NL80211_PLINK_ACTIONS)
+                        return -EINVAL;
+        }
 
         if (!rdev->ops->add_station)
                 return -EOPNOTSUPP;