batman-adv: don't let backbone gateways exchange tt entries

As the backbone gateways are connected to the same backbone, they
should announce the same clients on the backbone non-exclusively.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

4 files changed, 74 insertions, 2 deletions

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 56b9b4924763..6186f6e92e33 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -24,6 +24,7 @@
 #include "hard-interface.h"
 #include "originator.h"
 #include "bridge_loop_avoidance.h"
+#include "translation-table.h"
 #include "send.h"
 
 #include <linux/etherdevice.h>
@@ -359,6 +360,7 @@ static struct backbone_gw *bla_get_backbone_gw(struct bat_priv *bat_priv,
                                                uint8_t *orig, short vid)
 {
         struct backbone_gw *entry;
+        struct orig_node *orig_node;
         int hash_added;
 
         entry = backbone_hash_find(bat_priv, orig, vid);
@@ -393,6 +395,13 @@ static struct backbone_gw *bla_get_backbone_gw(struct bat_priv *bat_priv,
                 return NULL;
         }
 
+        /* this is a gateway now, remove any tt entries */
+        orig_node = orig_hash_find(bat_priv, orig);
+        if (orig_node) {
+                tt_global_del_orig(bat_priv, orig_node,
+                                   "became a backbone gateway");
+                orig_node_free_ref(orig_node);
+        }
         return entry;
 }
 
@@ -1050,6 +1059,47 @@ int bla_init(struct bat_priv *bat_priv)
 }
 
 /**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: originator mac address
+ *
+ * check if the originator is a gateway for any VLAN ID.
+ *
+ * returns 1 if it is found, 0 otherwise
+ *
+ */
+
+int bla_is_backbone_gw_orig(struct bat_priv *bat_priv, uint8_t *orig)
+{
+        struct hashtable_t *hash = bat_priv->backbone_hash;
+        struct hlist_head *head;
+        struct hlist_node *node;
+        struct backbone_gw *backbone_gw;
+        int i;
+
+        if (!atomic_read(&bat_priv->bridge_loop_avoidance))
+                return 0;
+
+        if (!hash)
+                return 0;
+
+        for (i = 0; i < hash->size; i++) {
+                head = &hash->table[i];
+
+                rcu_read_lock();
+                hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
+                        if (compare_eth(backbone_gw->orig, orig)) {
+                                rcu_read_unlock();
+                                return 1;
+                        }
+                }
+                rcu_read_unlock();
+        }
+
+        return 0;
+}
+
+
+/**
  * @skb: the frame to be checked
  * @orig_node: the orig_node of the frame
  * @hdr_size: maximum length of the frame
diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h
index d9e34803a465..b74940f09baf 100644
--- a/net/batman-adv/bridge_loop_avoidance.h
+++ b/net/batman-adv/bridge_loop_avoidance.h
@@ -27,6 +27,7 @@ int bla_tx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid);
 int bla_is_backbone_gw(struct sk_buff *skb,
                        struct orig_node *orig_node, int hdr_size);
 int bla_claim_table_seq_print_text(struct seq_file *seq, void *offset);
+int bla_is_backbone_gw_orig(struct bat_priv *bat_priv, uint8_t *orig);
 void bla_update_orig_address(struct bat_priv *bat_priv,
                              struct hard_iface *primary_if,
                              struct hard_iface *oldif);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index a1d8c9b0f902..1d1fd04c9c3a 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -673,6 +673,13 @@ int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
         if (!is_my_mac(roam_adv_packet->dst))
                 return route_unicast_packet(skb, recv_if);
 
+        /* check if it is a backbone gateway. we don't accept
+         * roaming advertisement from it, as it has the same
+         * entries as we have.
+         */
+        if (bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
+                goto out;
+
         orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
         if (!orig_node)
                 goto out;
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 9648b0dc57ef..e16a3690bdb2 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -27,6 +27,7 @@
 #include "hash.h"
 #include "originator.h"
 #include "routing.h"
+#include "bridge_loop_avoidance.h"
 
 #include <linux/crc16.h>
 
@@ -1615,10 +1616,15 @@ out:
 bool send_tt_response(struct bat_priv *bat_priv,
                       struct tt_query_packet *tt_request)
 {
-        if (is_my_mac(tt_request->dst))
+        if (is_my_mac(tt_request->dst)) {
+                /* don't answer backbone gws! */
+                if (bla_is_backbone_gw_orig(bat_priv, tt_request->src))
+                        return true;
+
                 return send_my_tt_response(bat_priv, tt_request);
-        else
+        } else {
                 return send_other_tt_response(bat_priv, tt_request);
+        }
 }
 
 static void _tt_update_changes(struct bat_priv *bat_priv,
@@ -1722,6 +1728,10 @@ void handle_tt_response(struct bat_priv *bat_priv,
                 tt_response->src, tt_response->ttvn, tt_response->tt_data,
                 (tt_response->flags & TT_FULL_TABLE ? 'F' : '.'));
 
+        /* we should have never asked a backbone gw */
+        if (bla_is_backbone_gw_orig(bat_priv, tt_response->src))
+                goto out;
+
         orig_node = orig_hash_find(bat_priv, tt_response->src);
         if (!orig_node)
                 goto out;
@@ -2052,6 +2062,10 @@ void tt_update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
         uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
         bool full_table = true;
 
+        /* don't care about a backbone gateways updates. */
+        if (bla_is_backbone_gw_orig(bat_priv, orig_node->orig))
+                return;
+
         /* orig table not initialised AND first diff is in the OGM OR the ttvn
          * increased by one -> we can apply the attached changes */
         if ((!orig_node->tt_initialised && ttvn == 1) ||