cfg80211: support non-inheritance element

Subelement profile may specify element IDs it doesn't inherit
from the management frame. Support it.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 48703ec60d06ceb6a936aba457f6475d9c661463..522881f31938b572b158f69e61d0dcd524e0b26c 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -2487,6 +2487,7 @@ enum ieee80211_eid_ext {
        WLAN_EID_EXT_HE_MU_EDCA = 38,
        WLAN_EID_EXT_MAX_CHANNEL_SWITCH_TIME = 52,
        WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION = 55,
+       WLAN_EID_EXT_NON_INHERITANCE = 56,
 };
 
 /* Action category code */

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 70432fd638afc21093005bca9e7dcff5254e15b1..777c4f0216100d3afa702f484afa65faedff4525 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5534,6 +5534,14 @@ static inline void cfg80211_gen_new_bssid(const u8 *bssid, u8 max_bssid,
        u64_to_ether_addr(new_bssid_u64, new_bssid);
 }
 
+/**
+ * cfg80211_is_element_inherited - returns if element ID should be inherited
+ * @element: element to check
+ * @non_inherit_element: non inheritance element
+ */
+bool cfg80211_is_element_inherited(const struct element *element,
+                                  const struct element *non_inherit_element);
+
 /**
  * enum cfg80211_bss_frame_type - frame type that the BSS data came from
  * @CFG80211_BSS_FTYPE_UNKNOWN: driver doesn't know whether the data is

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 49f700a1460b0274260977ef0e7256d2d087724f..bda9114ded77f86dbf66d393a47511b2a9d55763 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -179,12 +179,63 @@ static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
        return true;
 }
 
+bool cfg80211_is_element_inherited(const struct element *elem,
+                                  const struct element *non_inherit_elem)
+{
+       u8 id_len, ext_id_len, i, loop_len, id;
+       const u8 *list;
+
+       if (elem->id == WLAN_EID_MULTIPLE_BSSID)
+               return false;
+
+       if (!non_inherit_elem || non_inherit_elem->datalen < 2)
+               return true;
+
+       /*
+        * non inheritance element format is:
+        * ext ID (56) | IDs list len | list | extension IDs list len | list
+        * Both lists are optional. Both lengths are mandatory.
+        * This means valid length is:
+        * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths
+        */
+       id_len = non_inherit_elem->data[1];
+       if (non_inherit_elem->datalen < 3 + id_len)
+               return true;
+
+       ext_id_len = non_inherit_elem->data[2 + id_len];
+       if (non_inherit_elem->datalen < 3 + id_len + ext_id_len)
+               return true;
+
+       if (elem->id == WLAN_EID_EXTENSION) {
+               if (!ext_id_len)
+                       return true;
+               loop_len = ext_id_len;
+               list = &non_inherit_elem->data[3 + id_len];
+               id = elem->data[0];
+       } else {
+               if (!id_len)
+                       return true;
+               loop_len = id_len;
+               list = &non_inherit_elem->data[2];
+               id = elem->id;
+       }
+
+       for (i = 0; i < loop_len; i++) {
+               if (list[i] == id)
+                       return false;
+       }
+
+       return true;
+}
+EXPORT_SYMBOL(cfg80211_is_element_inherited);
+
 static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
                                  const u8 *subelement, size_t subie_len,
                                  u8 *new_ie, gfp_t gfp)
 {
        u8 *pos, *tmp;
        const u8 *tmp_old, *tmp_new;
+       const struct element *non_inherit_elem;
        u8 *sub_copy;
 
        /* copy subelement as we need to change its content to
@@ -204,6 +255,11 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
                pos += (tmp_new[1] + 2);
        }
 
+       /* get non inheritance list if exists */
+       non_inherit_elem =
+               cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
+                                      sub_copy, subie_len);
+
        /* go through IEs in ie (skip SSID) and subelement,
         * merge them into new_ie
         */
@@ -224,8 +280,11 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
                                                     subie_len);
 
                if (!tmp) {
+                       const struct element *old_elem = (void *)tmp_old;
+
                        /* ie in old ie but not in subelement */
-                       if (tmp_old[0] != WLAN_EID_MULTIPLE_BSSID) {
+                       if (cfg80211_is_element_inherited(old_elem,
+                                                         non_inherit_elem)) {
                                memcpy(pos, tmp_old, tmp_old[1] + 2);
                                pos += tmp_old[1] + 2;
                        }