Merge tag 'batman-adv-for-davem' of git://git.open-mesh.org/linux-merge

Included changes:
- minimal fixes to the packet layout to avoid the __packed attribute when not
  needed
- new packet type called UNICAST_4ADDR: in this packet it is possible to find
  both source and destination node (in the classic UNICAST header only the
  destination field exists).
- a new feature: Distributed ARP Table (D.A.T.). It aims to reduce ARP lookups
  latency by means of a simil-DHT approach.

Documentation/networking/batman-adv.txt

@@ -203,7 +203,8 @@ abled  during run time. Following log_levels are defined:
 2 - Enable messages related to route added / changed / deleted
 4 - Enable messages related to translation table operations
 8 - Enable messages related to bridge loop avoidance
-15 - enable all messages
+16 - Enable messaged related to DAT, ARP snooping and parsing
+31 - Enable all messages
 
 The debug output can be changed at runtime  using  the  file
 /sys/class/net/bat0/mesh/log_level. e.g.

net/batman-adv/Kconfig

@@ -25,6 +25,16 @@ config BATMAN_ADV_BLA
 	  more than one mesh node in the same LAN, you can safely remove
 	  this feature and save some space.
 
+config BATMAN_ADV_DAT
+	bool "Distributed ARP Table"
+	depends on BATMAN_ADV && INET
+	default n
+	help
+	  This option enables DAT (Distributed ARP Table), a DHT based
+	  mechanism that increases ARP reliability on sparse wireless
+	  mesh networks. If you think that your network does not need
+	  this option you can safely remove it and save some space.
+
 config BATMAN_ADV_DEBUG
 	bool "B.A.T.M.A.N. debugging"
 	depends on BATMAN_ADV

net/batman-adv/Makefile

@@ -23,6 +23,7 @@ batman-adv-y += bat_iv_ogm.o
 batman-adv-y += bitarray.o
 batman-adv-$(CONFIG_BATMAN_ADV_BLA) += bridge_loop_avoidance.o
 batman-adv-y += debugfs.o
+batman-adv-$(CONFIG_BATMAN_ADV_DAT) += distributed-arp-table.o
 batman-adv-y += gateway_client.o
 batman-adv-y += gateway_common.o
 batman-adv-y += hard-interface.o

net/batman-adv/bat_iv_ogm.c

@@ -411,9 +411,11 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 
 	if ((atomic_read(&bat_priv->aggregated_ogms)) &&
 	    (packet_len < BATADV_MAX_AGGREGATION_BYTES))
-		skb_size = BATADV_MAX_AGGREGATION_BYTES + ETH_HLEN;
+		skb_size = BATADV_MAX_AGGREGATION_BYTES;
 	else
-		skb_size = packet_len + ETH_HLEN;
+		skb_size = packet_len;
+
+	skb_size += ETH_HLEN + NET_IP_ALIGN;
 
 	forw_packet_aggr->skb = dev_alloc_skb(skb_size);
 	if (!forw_packet_aggr->skb) {
@@ -422,7 +424,7 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 		kfree(forw_packet_aggr);
 		goto out;
 	}
-	skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
+	skb_reserve(forw_packet_aggr->skb, ETH_HLEN + NET_IP_ALIGN);
 
 	INIT_HLIST_NODE(&forw_packet_aggr->list);
 

net/batman-adv/debugfs.c

@@ -31,6 +31,7 @@
 #include "vis.h"
 #include "icmp_socket.h"
 #include "bridge_loop_avoidance.h"
+#include "distributed-arp-table.h"
 
 static struct dentry *batadv_debugfs;
 
@@ -280,6 +281,19 @@ static int batadv_bla_backbone_table_open(struct inode *inode,
 
 #endif
 
+#ifdef CONFIG_BATMAN_ADV_DAT
+/**
+ * batadv_dat_cache_open - Prepare file handler for reads from dat_chache
+ * @inode: inode which was opened
+ * @file: file handle to be initialized
+ */
+static int batadv_dat_cache_open(struct inode *inode, struct file *file)
+{
+	struct net_device *net_dev = (struct net_device *)inode->i_private;
+	return single_open(file, batadv_dat_cache_seq_print_text, net_dev);
+}
+#endif
+
 static int batadv_transtable_local_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
@@ -319,6 +333,9 @@ static BATADV_DEBUGINFO(bla_claim_table, S_IRUGO, batadv_bla_claim_table_open);
 static BATADV_DEBUGINFO(bla_backbone_table, S_IRUGO,
 			batadv_bla_backbone_table_open);
 #endif
+#ifdef CONFIG_BATMAN_ADV_DAT
+static BATADV_DEBUGINFO(dat_cache, S_IRUGO, batadv_dat_cache_open);
+#endif
 static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
 			batadv_transtable_local_open);
 static BATADV_DEBUGINFO(vis_data, S_IRUGO, batadv_vis_data_open);
@@ -330,6 +347,9 @@ static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 #ifdef CONFIG_BATMAN_ADV_BLA
 	&batadv_debuginfo_bla_claim_table,
 	&batadv_debuginfo_bla_backbone_table,
+#endif
+#ifdef CONFIG_BATMAN_ADV_DAT
+	&batadv_debuginfo_dat_cache,
 #endif
 	&batadv_debuginfo_transtable_local,
 	&batadv_debuginfo_vis_data,