batman-adv: Distributed ARP Table - add runtime switch

This patch adds a runtime switch that enables the user to turn the DAT feature
on or off at runtime

Signed-off-by: Antonio Quartulli <ordex@autistici.org>

4 files changed, 31 insertions, 0 deletions

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index f43bf8e4a2b7..c1a74a126f58 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -621,6 +621,9 @@ out:
  */
 static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
 {
+        if (!bat_priv->dat.hash)
+                return;
+
         __batadv_dat_purge(bat_priv, NULL);
 
         batadv_hash_destroy(bat_priv->dat.hash);
@@ -790,6 +793,9 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
         struct sk_buff *skb_new;
         struct batadv_hard_iface *primary_if = NULL;
 
+        if (!atomic_read(&bat_priv->distributed_arp_table))
+                goto out;
+
         type = batadv_arp_get_type(bat_priv, skb, 0);
         /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
          * message to the selected DHT candidates
@@ -861,6 +867,9 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
         bool ret = false;
         int err;
 
+        if (!atomic_read(&bat_priv->distributed_arp_table))
+                goto out;
+
         type = batadv_arp_get_type(bat_priv, skb, hdr_size);
         if (type != ARPOP_REQUEST)
                 goto out;
@@ -924,6 +933,9 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
         __be32 ip_src, ip_dst;
         uint8_t *hw_src, *hw_dst;
 
+        if (!atomic_read(&bat_priv->distributed_arp_table))
+                return;
+
         type = batadv_arp_get_type(bat_priv, skb, 0);
         if (type != ARPOP_REPLY)
                 return;
@@ -959,6 +971,9 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
         uint8_t *hw_src, *hw_dst;
         bool ret = false;
 
+        if (!atomic_read(&bat_priv->distributed_arp_table))
+                goto out;
+
         type = batadv_arp_get_type(bat_priv, skb, hdr_size);
         if (type != ARPOP_REPLY)
                 goto out;
@@ -1003,6 +1018,9 @@ bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
         bool ret = false;
         const size_t bcast_len = sizeof(struct batadv_bcast_packet);
 
+        if (!atomic_read(&bat_priv->distributed_arp_table))
+                goto out;
+
         /* If this packet is an ARP_REQUEST and the node already has the
          * information that it is going to ask, then the packet can be dropped
          */
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 9dc0ae1d4da3..7b4a3a3d9dd5 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -480,6 +480,9 @@ struct net_device *batadv_softif_create(const char *name)
         atomic_set(&bat_priv->aggregated_ogms, 1);
         atomic_set(&bat_priv->bonding, 0);
         atomic_set(&bat_priv->bridge_loop_avoidance, 0);
+#ifdef CONFIG_BATMAN_ADV_DAT
+        atomic_set(&bat_priv->distributed_arp_table, 1);
+#endif
         atomic_set(&bat_priv->ap_isolation, 0);
         atomic_set(&bat_priv->vis_mode, BATADV_VIS_TYPE_CLIENT_UPDATE);
         atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
index 42cd09e24c5f..fa3cc1af0918 100644
--- a/net/batman-adv/sysfs.c
+++ b/net/batman-adv/sysfs.c
@@ -20,6 +20,7 @@
 #include "main.h"
 #include "sysfs.h"
 #include "translation-table.h"
+#include "distributed-arp-table.h"
 #include "originator.h"
 #include "hard-interface.h"
 #include "gateway_common.h"
@@ -420,6 +421,9 @@ BATADV_ATTR_SIF_BOOL(bonding, S_IRUGO | S_IWUSR, NULL);
 #ifdef CONFIG_BATMAN_ADV_BLA
 BATADV_ATTR_SIF_BOOL(bridge_loop_avoidance, S_IRUGO | S_IWUSR, NULL);
 #endif
+#ifdef CONFIG_BATMAN_ADV_DAT
+BATADV_ATTR_SIF_BOOL(distributed_arp_table, S_IRUGO | S_IWUSR, NULL);
+#endif
 BATADV_ATTR_SIF_BOOL(fragmentation, S_IRUGO | S_IWUSR, batadv_update_min_mtu);
 BATADV_ATTR_SIF_BOOL(ap_isolation, S_IRUGO | S_IWUSR, NULL);
 static BATADV_ATTR(vis_mode, S_IRUGO | S_IWUSR, batadv_show_vis_mode,
@@ -445,6 +449,9 @@ static struct batadv_attribute *batadv_mesh_attrs[] = {
 #ifdef CONFIG_BATMAN_ADV_BLA
         &batadv_attr_bridge_loop_avoidance,
 #endif
+#ifdef CONFIG_BATMAN_ADV_DAT
+        &batadv_attr_distributed_arp_table,
+#endif
         &batadv_attr_fragmentation,
         &batadv_attr_ap_isolation,
         &batadv_attr_vis_mode,
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 00d3093f3a9c..0afeb2b43f70 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -275,6 +275,9 @@ struct batadv_priv {
         atomic_t fragmentation;         /* boolean */
         atomic_t ap_isolation;          /* boolean */
         atomic_t bridge_loop_avoidance; /* boolean */
+#ifdef CONFIG_BATMAN_ADV_DAT
+        atomic_t distributed_arp_table; /* boolean */
+#endif
         atomic_t vis_mode;              /* VIS_TYPE_* */
         atomic_t gw_mode;               /* GW_MODE_* */
         atomic_t gw_sel_class;          /* uint */