wireless: Support ht-capabilities over-rides.

This allows users to disable features such as HT, HT40,
and to modify the MCS, AMPDU, and AMSDU settings for
drivers that support it.

The MCS, AMPDU, and AMSDU features that may be disabled are
are reported in the phy-info netlink message as a mask.

Attemping to disable features that are not supported will
take no affect, but will not return errors.  This is to aid
backwards compatibility in user-space apps that may not be
clever enough to deal with parsing the the capabilities mask.

This patch only enables the infrastructure.  An additional
patch will enable the feature in mac80211.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 41 insertions, 0 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 6396819a7e41..97bfebfcce90 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1169,6 +1169,17 @@ enum nl80211_commands {
  * @NL80211_ATTR_PROBE_RESP: Probe Response template data. Contains the entire
  *      probe-response frame. The DA field in the 802.11 header is zero-ed out,
  *      to be filled by the FW.
+ * @NL80211_ATTR_DISABLE_HT:  Force HT capable interfaces to disable
+ *      this feature.  Currently, only supported in mac80211 drivers.
+ * @NL80211_ATTR_HT_CAPABILITY_MASK: Specify which bits of the
+ *      ATTR_HT_CAPABILITY to which attention should be paid.
+ *      Currently, only mac80211 NICs support this feature.
+ *      The values that may be configured are:
+ *       MCS rates, MAX-AMSDU, HT-20-40 and HT_CAP_SGI_40
+ *       AMPDU density and AMPDU factor.
+ *      All values are treated as suggestions and may be ignored
+ *      by the driver as required.  The actual values may be seen in
+ *      the station debugfs ht_caps file.
  *
  * @NL80211_ATTR_DFS_REGION: region for regulatory rules which this country
  *    abides to when initiating radiation on DFS channels. A country maps
@@ -1414,6 +1425,9 @@ enum nl80211_attrs {
 
         NL80211_ATTR_DFS_REGION,
 
+        NL80211_ATTR_DISABLE_HT,
+        NL80211_ATTR_HT_CAPABILITY_MASK,
+
         /* add attributes here, update the policy in nl80211.c */
 
         __NL80211_ATTR_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6a1d849c597a..d5e18913f293 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1044,6 +1044,15 @@ struct cfg80211_auth_request {
 };
 
 /**
+ * enum cfg80211_assoc_req_flags - Over-ride default behaviour in association.
+ *
+ * @ASSOC_REQ_DISABLE_HT:  Disable HT (802.11n)
+ */
+enum cfg80211_assoc_req_flags {
+        ASSOC_REQ_DISABLE_HT            = BIT(0),
+};
+
+/**
  * struct cfg80211_assoc_request - (Re)Association request data
  *
  * This structure provides information needed to complete IEEE 802.11
@@ -1054,6 +1063,10 @@ struct cfg80211_auth_request {
  * @use_mfp: Use management frame protection (IEEE 802.11w) in this association
  * @crypto: crypto settings
  * @prev_bssid: previous BSSID, if not %NULL use reassociate frame
+ * @flags:  See &enum cfg80211_assoc_req_flags
+ * @ht_capa:  HT Capabilities over-rides.  Values set in ht_capa_mask
+ *   will be used in ht_capa.  Un-supported values will be ignored.
+ * @ht_capa_mask:  The bits of ht_capa which are to be used.
  */
 struct cfg80211_assoc_request {
         struct cfg80211_bss *bss;
@@ -1061,6 +1074,9 @@ struct cfg80211_assoc_request {
         size_t ie_len;
         struct cfg80211_crypto_settings crypto;
         bool use_mfp;
+        u32 flags;
+        struct ieee80211_ht_cap ht_capa;
+        struct ieee80211_ht_cap ht_capa_mask;
 };
 
 /**
@@ -1159,6 +1175,10 @@ struct cfg80211_ibss_params {
  * @key_len: length of WEP key for shared key authentication
  * @key_idx: index of WEP key for shared key authentication
  * @key: WEP key for shared key authentication
+ * @flags:  See &enum cfg80211_assoc_req_flags
+ * @ht_capa:  HT Capabilities over-rides.  Values set in ht_capa_mask
+ *   will be used in ht_capa.  Un-supported values will be ignored.
+ * @ht_capa_mask:  The bits of ht_capa which are to be used.
  */
 struct cfg80211_connect_params {
         struct ieee80211_channel *channel;
@@ -1172,6 +1192,9 @@ struct cfg80211_connect_params {
         struct cfg80211_crypto_settings crypto;
         const u8 *key;
         u8 key_len, key_idx;
+        u32 flags;
+        struct ieee80211_ht_cap ht_capa;
+        struct ieee80211_ht_cap ht_capa_mask;
 };
 
 /**
@@ -1938,6 +1961,8 @@ struct wiphy_wowlan_support {
  * @wowlan: WoWLAN support information
  *
  * @ap_sme_capa: AP SME capabilities, flags from &enum nl80211_ap_sme_features.
+ * @ht_capa_mod_mask:  Specify what ht_cap values can be over-ridden.
+ *      If null, then none can be over-ridden.
  */
 struct wiphy {
         /* assign these fields before you register the wiphy */
@@ -2027,6 +2052,8 @@ struct wiphy {
         /* dir in debugfs: ieee80211/<wiphyname> */
         struct dentry *debugfsdir;
 
+        const struct ieee80211_ht_cap *ht_capa_mod_mask;
+
 #ifdef CONFIG_NET_NS
         /* the network namespace this phy lives in currently */
         struct net *_net;