cfg80211: support profile split between elements

Since an element is limited to 255 octets, a profile may be split
split to several elements. Support the split as defined in the 11ax
draft 3. Detect legacy split and print a net-rate limited warning,
since there is no ROI in supporting this probably non-existent
split.

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/net/cfg80211.h b/include/net/cfg80211.h
index 777c4f0216100d3afa702f484afa65faedff4525..f6665f8eba5a6a435cc7184342aee54195de7119 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5542,6 +5542,20 @@ static inline void cfg80211_gen_new_bssid(const u8 *bssid, u8 max_bssid,
 bool cfg80211_is_element_inherited(const struct element *element,
                                   const struct element *non_inherit_element);
 
+/**
+ * cfg80211_merge_profile - merges a MBSSID profile if it is split between IEs
+ * @ie: ies
+ * @ielen: length of IEs
+ * @mbssid_elem: current MBSSID element
+ * @sub_elem: current MBSSID subelement (profile)
+ * @merged_ie: location of the merged profile
+ * @max_copy_len: max merged profile length
+ */
+size_t cfg80211_merge_profile(const u8 *ie, size_t ielen,
+                             const struct element *mbssid_elem,
+                             const struct element *sub_elem,
+                             u8 **merged_ie, size_t max_copy_len);
+
 /**
  * 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 bda9114ded77f86dbf66d393a47511b2a9d55763..878c867f3f7d40f7cdafb406d9e09d450b10bfbf 100644 (file)
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1456,6 +1456,78 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
        return &res->pub;
 }
 
+static const struct element
+*cfg80211_get_profile_continuation(const u8 *ie, size_t ielen,
+                                  const struct element *mbssid_elem,
+                                  const struct element *sub_elem)
+{
+       const u8 *mbssid_end = mbssid_elem->data + mbssid_elem->datalen;
+       const struct element *next_mbssid;
+       const struct element *next_sub;
+
+       next_mbssid = cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID,
+                                        mbssid_end,
+                                        ielen - (mbssid_end - ie));
+
+       /*
+        * If is is not the last subelement in current MBSSID IE or there isn't
+        * a next MBSSID IE - profile is complete.
+       */
+       if ((sub_elem->data + sub_elem->datalen < mbssid_end - 1) ||
+           !next_mbssid)
+               return NULL;
+
+       /* For any length error, just return NULL */
+
+       if (next_mbssid->datalen < 4)
+               return NULL;
+
+       next_sub = (void *)&next_mbssid->data[1];
+
+       if (next_mbssid->data + next_mbssid->datalen <
+           next_sub->data + next_sub->datalen)
+               return NULL;
+
+       if (next_sub->id != 0 || next_sub->datalen < 2)
+               return NULL;
+
+       /*
+        * Check if the first element in the next sub element is a start
+        * of a new profile
+        */
+       return next_sub->data[0] == WLAN_EID_NON_TX_BSSID_CAP ?
+              NULL : next_mbssid;
+}
+
+size_t cfg80211_merge_profile(const u8 *ie, size_t ielen,
+                             const struct element *mbssid_elem,
+                             const struct element *sub_elem,
+                             u8 **merged_ie, size_t max_copy_len)
+{
+       size_t copied_len = sub_elem->datalen;
+       const struct element *next_mbssid;
+
+       if (sub_elem->datalen > max_copy_len)
+               return 0;
+
+       memcpy(*merged_ie, sub_elem->data, sub_elem->datalen);
+
+       while ((next_mbssid = cfg80211_get_profile_continuation(ie, ielen,
+                                                               mbssid_elem,
+                                                               sub_elem))) {
+               const struct element *next_sub = (void *)&next_mbssid->data[1];
+
+               if (copied_len + next_sub->datalen > max_copy_len)
+                       break;
+               memcpy(*merged_ie + copied_len, next_sub->data,
+                      next_sub->datalen);
+               copied_len += next_sub->datalen;
+       }
+
+       return copied_len;
+}
+EXPORT_SYMBOL(cfg80211_merge_profile);
+
 static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
                                       struct cfg80211_inform_bss *data,
                                       enum cfg80211_bss_frame_type ftype,
@@ -1469,7 +1541,8 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
        const struct element *elem, *sub;
        size_t new_ie_len;
        u8 new_bssid[ETH_ALEN];
-       u8 *new_ie;
+       u8 *new_ie, *profile;
+       u64 seen_indices = 0;
        u16 capability;
        struct cfg80211_bss *bss;
 
@@ -1487,10 +1560,16 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
        if (!new_ie)
                return;
 
+       profile = kmalloc(ielen, gfp);
+       if (!profile)
+               goto out;
+
        for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) {
                if (elem->datalen < 4)
                        continue;
                for_each_element(sub, elem->data + 1, elem->datalen - 1) {
+                       u8 profile_len;
+
                        if (sub->id != 0 || sub->datalen < 4) {
                                /* not a valid BSS profile */
                                continue;
@@ -1505,16 +1584,31 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
                                continue;
                        }
 
+                       memset(profile, 0, ielen);
+                       profile_len = cfg80211_merge_profile(ie, ielen,
+                                                            elem,
+                                                            sub,
+                                                            &profile,
+                                                            ielen);
+
                        /* found a Nontransmitted BSSID Profile */
                        mbssid_index_ie = cfg80211_find_ie
                                (WLAN_EID_MULTI_BSSID_IDX,
-                                sub->data, sub->datalen);
+                                profile, profile_len);
                        if (!mbssid_index_ie || mbssid_index_ie[1] < 1 ||
-                           mbssid_index_ie[2] == 0) {
+                           mbssid_index_ie[2] == 0 ||
+                           mbssid_index_ie[2] > 46) {
                                /* No valid Multiple BSSID-Index element */
                                continue;
                        }
 
+                       if (seen_indices & BIT(mbssid_index_ie[2]))
+                               /* We don't support legacy split of a profile */
+                               net_dbg_ratelimited("Partial info for BSSID index %d\n",
+                                                   mbssid_index_ie[2]);
+
+                       seen_indices |= BIT(mbssid_index_ie[2]);
+
                        non_tx_data->bssid_index = mbssid_index_ie[2];
                        non_tx_data->max_bssid_indicator = elem->data[0];
 
@@ -1523,13 +1617,14 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
                                               non_tx_data->bssid_index,
                                               new_bssid);
                        memset(new_ie, 0, IEEE80211_MAX_DATA_LEN);
-                       new_ie_len = cfg80211_gen_new_ie(ie, ielen, sub->data,
-                                                        sub->datalen, new_ie,
+                       new_ie_len = cfg80211_gen_new_ie(ie, ielen,
+                                                        profile,
+                                                        profile_len, new_ie,
                                                         gfp);
                        if (!new_ie_len)
                                continue;
 
-                       capability = get_unaligned_le16(sub->data + 2);
+                       capability = get_unaligned_le16(profile + 2);
                        bss = cfg80211_inform_single_bss_data(wiphy, data,
                                                              ftype,
                                                              new_bssid, tsf,
@@ -1545,7 +1640,9 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
                }
        }
 
+out:
        kfree(new_ie);
+       kfree(profile);
 }
 
 struct cfg80211_bss *