wifi: mac80211: verify link addresses are different

When adding multiple links, verify that they all have
different addresses.

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

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index bf3bc43411acad299d3e104c17e281e8dd240d86..e544621ead0ef80507f20763bc0d81240f2d3369 100644 (file)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -444,6 +444,32 @@ static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
        }
 }
 
+static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
+{
+       unsigned int i, j;
+
+       for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
+               struct ieee80211_link_data *link1;
+
+               link1 = sdata_dereference(sdata->link[i], sdata);
+               if (!link1)
+                       continue;
+               for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
+                       struct ieee80211_link_data *link2;
+
+                       link2 = sdata_dereference(sdata->link[j], sdata);
+                       if (!link2)
+                               continue;
+
+                       if (ether_addr_equal(link1->conf->addr,
+                                            link2->conf->addr))
+                               return -EALREADY;
+               }
+       }
+
+       return 0;
+}
+
 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
                                      struct link_container **to_free,
                                      u16 new_links)
@@ -518,10 +544,14 @@ static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
 
        sdata->vif.valid_links = new_links;
 
-       /* tell the driver */
-       ret = drv_change_vif_links(sdata->local, sdata,
-                                  old_links, new_links,
-                                  old);
+       ret = ieee80211_check_dup_link_addrs(sdata);
+       if (!ret) {
+               /* tell the driver */
+               ret = drv_change_vif_links(sdata->local, sdata,
+                                          old_links, new_links,
+                                          old);
+       }
+
        if (ret) {
                /* restore config */
                memcpy(sdata->link, old_data, sizeof(old_data));