mac80211: split up and insert custom IEs correctly

Currently, we insert all user-specified IEs before the HT
IE for association, and after the HT IE for probe requests.
For association, that's correct only if the user-specified
IEs are RSN only, incorrect in all other cases including
WPA. Change this to split apart the user-specified IEs in
two places for association: before the HT IE (e.g. RSN),
after the HT IE (generally empty right now I think?) and
after WMM (all other vendor-specific IEs). For probes,
split the IEs in different places to be correct according
to the spec.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 36 insertions, 7 deletions

diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index c03c22d5bca3..affdd10b67ad 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -204,6 +204,7 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
         struct ieee80211_mgmt *mgmt;
         u8 *pos;
         const u8 *ies;
+        size_t offset = 0, noffset;
         int i, len, count, rates_len, supp_rates_len;
         u16 capab;
         struct ieee80211_supported_band *sband;
@@ -337,14 +338,26 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
-        /*
-         * XXX: These IEs could contain (vendor-specified)
-         *      IEs that belong after HT -- the buffer may
-         *      need to be split up.
-         */
+        /* if present, add any custom IEs that go before HT */
         if (wk->ie_len && wk->ie) {
-                pos = skb_put(skb, wk->ie_len);
-                memcpy(pos, wk->ie, wk->ie_len);
+                static const u8 before_ht[] = {
+                        WLAN_EID_SSID,
+                        WLAN_EID_SUPP_RATES,
+                        WLAN_EID_EXT_SUPP_RATES,
+                        WLAN_EID_PWR_CAPABILITY,
+                        WLAN_EID_SUPPORTED_CHANNELS,
+                        WLAN_EID_RSN,
+                        WLAN_EID_QOS_CAPA,
+                        WLAN_EID_RRM_ENABLED_CAPABILITIES,
+                        WLAN_EID_MOBILITY_DOMAIN,
+                        WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
+                };
+                noffset = ieee80211_ie_split(wk->ie, wk->ie_len,
+                                             before_ht, ARRAY_SIZE(before_ht),
+                                             offset);
+                pos = skb_put(skb, noffset - offset);
+                memcpy(pos, wk->ie + offset, noffset - offset);
+                offset = noffset;
         }
 
         if (wk->assoc.use_11n && wk->assoc.wmm_used &&
@@ -352,6 +365,15 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
                 ieee80211_add_ht_ie(skb, wk->assoc.ht_information_ie,
                                     sband, wk->chan, wk->assoc.smps);
 
+        /* if present, add any custom non-vendor IEs that go after HT */
+        if (wk->ie_len && wk->ie) {
+                noffset = ieee80211_ie_split_vendor(wk->ie, wk->ie_len,
+                                                    offset);
+                pos = skb_put(skb, noffset - offset);
+                memcpy(pos, wk->ie + offset, noffset - offset);
+                offset = noffset;
+        }
+
         if (wk->assoc.wmm_used && local->hw.queues >= 4) {
                 pos = skb_put(skb, 9);
                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
@@ -365,6 +387,13 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
                 *pos++ = 0;
         }
 
+        /* add any remaining custom (i.e. vendor specific here) IEs */
+        if (wk->ie_len && wk->ie) {
+                noffset = wk->ie_len;
+                pos = skb_put(skb, noffset - offset);
+                memcpy(pos, wk->ie + offset, noffset - offset);
+        }
+
         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
         ieee80211_tx_skb(sdata, skb);
 }