batman-adv: implement AP-isolation on the sender side

If a node has to send a packet issued by a WIFI client to another WIFI client,
the packet is dropped.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

5 files changed, 29 insertions, 12 deletions

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 13444e92bc9..91a7860ecad 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1535,7 +1535,7 @@ static int check_unicast_ttvn(struct bat_priv *bat_priv,
 
                 ethhdr = (struct ethhdr *)(skb->data +
                         sizeof(struct unicast_packet));
-                orig_node = transtable_search(bat_priv, ethhdr->h_dest);
+                orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
 
                 if (!orig_node) {
                         if (!is_my_client(bat_priv, ethhdr->h_dest))
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 9addbab5299..402fd96239d 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -597,7 +597,8 @@ static int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)
         /* Register the client MAC in the transtable */
         tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);
 
-        orig_node = transtable_search(bat_priv, ethhdr->h_dest);
+        orig_node = transtable_search(bat_priv, ethhdr->h_source,
+                                      ethhdr->h_dest);
         if (is_multicast_ether_addr(ethhdr->h_dest) ||
                                 (orig_node && orig_node->gw_flags)) {
                 ret = gw_is_target(bat_priv, skb, orig_node);
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index d0ed931ad2e..1f128e1656a 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -794,29 +794,43 @@ static bool _is_ap_isolated(struct tt_local_entry *tt_local_entry,
 }
 
 struct orig_node *transtable_search(struct bat_priv *bat_priv,
-                                    const uint8_t *addr)
+                                    const uint8_t *src, const uint8_t *addr)
 {
-        struct tt_global_entry *tt_global_entry;
+        struct tt_local_entry *tt_local_entry = NULL;
+        struct tt_global_entry *tt_global_entry = NULL;
         struct orig_node *orig_node = NULL;
 
-        tt_global_entry = tt_global_hash_find(bat_priv, addr);
+        if (src && atomic_read(&bat_priv->ap_isolation)) {
+                tt_local_entry = tt_local_hash_find(bat_priv, src);
+                if (!tt_local_entry)
+                        goto out;
+        }
 
+        tt_global_entry = tt_global_hash_find(bat_priv, addr);
         if (!tt_global_entry)
                 goto out;
 
+        /* check whether the clients should not communicate due to AP
+         * isolation */
+        if (tt_local_entry && _is_ap_isolated(tt_local_entry, tt_global_entry))
+                goto out;
+
         if (!atomic_inc_not_zero(&tt_global_entry->orig_node->refcount))
-                goto free_tt;
+                goto out;
 
         /* A global client marked as PENDING has already moved from that
          * originator */
         if (tt_global_entry->flags & TT_CLIENT_PENDING)
-                goto free_tt;
+                goto out;
 
         orig_node = tt_global_entry->orig_node;
 
-free_tt:
-        tt_global_entry_free_ref(tt_global_entry);
 out:
+        if (tt_global_entry)
+                tt_global_entry_free_ref(tt_global_entry);
+        if (tt_local_entry)
+                tt_local_entry_free_ref(tt_local_entry);
+
         return orig_node;
 }
 
diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h
index f1d148ef0e3..b47e8760b76 100644
--- a/net/batman-adv/translation-table.h
+++ b/net/batman-adv/translation-table.h
@@ -43,7 +43,7 @@ void tt_global_del(struct bat_priv *bat_priv,
                    struct orig_node *orig_node, const unsigned char *addr,
                    const char *message, bool roaming);
 struct orig_node *transtable_search(struct bat_priv *bat_priv,
-                                    const uint8_t *addr);
+                                    const uint8_t *src, const uint8_t *addr);
 void tt_save_orig_buffer(struct bat_priv *bat_priv, struct orig_node *orig_node,
                          const unsigned char *tt_buff, uint8_t tt_num_changes);
 uint16_t tt_local_crc(struct bat_priv *bat_priv);
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index 32b125fb3d3..07d1c1da89d 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -299,8 +299,10 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
                         goto find_router;
         }
 
-        /* check for tt host - increases orig_node refcount */
-        orig_node = transtable_search(bat_priv, ethhdr->h_dest);
+        /* check for tt host - increases orig_node refcount.
+         * returns NULL in case of AP isolation */
+        orig_node = transtable_search(bat_priv, ethhdr->h_source,
+                                      ethhdr->h_dest);
 
 find_router:
         /**