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

Included changes:
- introduction of the new Network Coding component. This new mechanism aims to
  increase throughput by fusing multiple packets in one transmission.
- minor cleanups

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/ABI/testing/sysfs-class-net-mesh

@@ -67,6 +67,14 @@ Description:
                 Defines the penalty which will be applied to an
                 originator message's tq-field on every hop.
 
+What:           /sys/class/net/<mesh_iface>/mesh/network_coding
+Date:           Nov 2012
+Contact:        Martin Hundeboll <martin@hundeboll.net>
+Description:
+                Controls whether Network Coding (using some magic
+                to send fewer wifi packets but still the same
+                content) is enabled or not.
+
 What:           /sys/class/net/<mesh_iface>/mesh/orig_interval
 Date:           May 2010
 Contact:        Marek Lindner <lindner_marek@yahoo.de>

net/batman-adv/Kconfig

@@ -36,6 +36,20 @@ config BATMAN_ADV_DAT
 	  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_NC
+	bool "Network Coding"
+	depends on BATMAN_ADV
+	default n
+	help
+	  This option enables network coding, a mechanism that aims to
+	  increase the overall network throughput by fusing multiple
+	  packets in one transmission.
+	  Note that interfaces controlled by batman-adv must be manually
+	  configured to have promiscuous mode enabled in order to make
+	  network coding work.
+	  If you think that your network does not need this feature you
+	  can safely disable 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

@@ -30,6 +30,7 @@ batman-adv-y += hard-interface.o
 batman-adv-y += hash.o
 batman-adv-y += icmp_socket.o
 batman-adv-y += main.o
+batman-adv-$(CONFIG_BATMAN_ADV_NC) += network-coding.o
 batman-adv-y += originator.o
 batman-adv-y += ring_buffer.o
 batman-adv-y += routing.o

net/batman-adv/bat_iv_ogm.c

@@ -27,6 +27,7 @@
 #include "hard-interface.h"
 #include "send.h"
 #include "bat_algo.h"
+#include "network-coding.h"
 
 static struct batadv_neigh_node *
 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
@@ -1185,6 +1186,10 @@ static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
 	if (!orig_neigh_node)
 		goto out;
 
+	/* Update nc_nodes of the originator */
+	batadv_nc_update_nc_node(bat_priv, orig_node, orig_neigh_node,
+				 batadv_ogm_packet, is_single_hop_neigh);
+
 	orig_neigh_router = batadv_orig_node_get_router(orig_neigh_node);
 
 	/* drop packet if sender is not a direct neighbor and if we

net/batman-adv/debugfs.c

@@ -32,6 +32,7 @@
 #include "icmp_socket.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
+#include "network-coding.h"
 
 static struct dentry *batadv_debugfs;
 
@@ -310,6 +311,14 @@ struct batadv_debuginfo {
 	const struct file_operations fops;
 };
 
+#ifdef CONFIG_BATMAN_ADV_NC
+static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
+{
+	struct net_device *net_dev = (struct net_device *)inode->i_private;
+	return single_open(file, batadv_nc_nodes_seq_print_text, net_dev);
+}
+#endif
+
 #define BATADV_DEBUGINFO(_name, _mode, _open)		\
 struct batadv_debuginfo batadv_debuginfo_##_name = {	\
 	.attr = { .name = __stringify(_name),		\
@@ -348,6 +357,9 @@ static BATADV_DEBUGINFO(dat_cache, S_IRUGO, batadv_dat_cache_open);
 static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
 			batadv_transtable_local_open);
 static BATADV_DEBUGINFO(vis_data, S_IRUGO, batadv_vis_data_open);
+#ifdef CONFIG_BATMAN_ADV_NC
+static BATADV_DEBUGINFO(nc_nodes, S_IRUGO, batadv_nc_nodes_open);
+#endif
 
 static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 	&batadv_debuginfo_originators,
@@ -362,6 +374,9 @@ static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 #endif
 	&batadv_debuginfo_transtable_local,
 	&batadv_debuginfo_vis_data,
+#ifdef CONFIG_BATMAN_ADV_NC
+	&batadv_debuginfo_nc_nodes,
+#endif
 	NULL,
 };
 
@@ -431,6 +446,9 @@ int batadv_debugfs_add_meshif(struct net_device *dev)
 		}
 	}
 
+	if (batadv_nc_init_debugfs(bat_priv) < 0)
+		goto rem_attr;
+
 	return 0;
 rem_attr:
 	debugfs_remove_recursive(bat_priv->debug_dir);

net/batman-adv/distributed-arp-table.c

@@ -816,7 +816,6 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
 	bool ret = false;
 	struct batadv_dat_entry *dat_entry = NULL;
 	struct sk_buff *skb_new;
-	struct batadv_hard_iface *primary_if = NULL;
 
 	if (!atomic_read(&bat_priv->distributed_arp_table))
 		goto out;
@@ -838,22 +837,18 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
 
 	dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst);
 	if (dat_entry) {
-		primary_if = batadv_primary_if_get_selected(bat_priv);
-		if (!primary_if)
-			goto out;
-
 		skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
-				     primary_if->soft_iface, ip_dst, hw_src,
+				     bat_priv->soft_iface, ip_dst, hw_src,
 				     dat_entry->mac_addr, hw_src);
 		if (!skb_new)
 			goto out;
 
 		skb_reset_mac_header(skb_new);
 		skb_new->protocol = eth_type_trans(skb_new,
-						   primary_if->soft_iface);
+						   bat_priv->soft_iface);
 		bat_priv->stats.rx_packets++;
 		bat_priv->stats.rx_bytes += skb->len + ETH_HLEN;
-		primary_if->soft_iface->last_rx = jiffies;
+		bat_priv->soft_iface->last_rx = jiffies;
 
 		netif_rx(skb_new);
 		batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
@@ -866,8 +861,6 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
 out:
 	if (dat_entry)
 		batadv_dat_entry_free_ref(dat_entry);
-	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
 	return ret;
 }
 
@@ -887,7 +880,6 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
 	__be32 ip_src, ip_dst;
 	uint8_t *hw_src;
 	struct sk_buff *skb_new;
-	struct batadv_hard_iface *primary_if = NULL;
 	struct batadv_dat_entry *dat_entry = NULL;
 	bool ret = false;
 	int err;
@@ -912,12 +904,8 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
 	if (!dat_entry)
 		goto out;
 
-	primary_if = batadv_primary_if_get_selected(bat_priv);
-	if (!primary_if)
-		goto out;
-
 	skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
-			     primary_if->soft_iface, ip_dst, hw_src,
+			     bat_priv->soft_iface, ip_dst, hw_src,
 			     dat_entry->mac_addr, hw_src);
 
 	if (!skb_new)
@@ -941,8 +929,6 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
 out:
 	if (dat_entry)
 		batadv_dat_entry_free_ref(dat_entry);
-	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
 	if (ret)
 		kfree_skb(skb);
 	return ret;

net/batman-adv/main.c

@@ -35,6 +35,7 @@
 #include "vis.h"
 #include "hash.h"
 #include "bat_algo.h"
+#include "network-coding.h"
 
 
 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
@@ -135,6 +136,10 @@ int batadv_mesh_init(struct net_device *soft_iface)
 	if (ret < 0)
 		goto err;
 
+	ret = batadv_nc_init(bat_priv);
+	if (ret < 0)
+		goto err;
+
 	atomic_set(&bat_priv->gw.reselect, 0);
 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 
@@ -157,6 +162,7 @@ void batadv_mesh_free(struct net_device *soft_iface)
 
 	batadv_gw_node_purge(bat_priv);
 	batadv_originator_free(bat_priv);
+	batadv_nc_free(bat_priv);
 
 	batadv_tt_free(bat_priv);
 

net/batman-adv/main.h

@@ -105,6 +105,8 @@
 #define BATADV_RESET_PROTECTION_MS 30000
 #define BATADV_EXPECTED_SEQNO_RANGE	65536
 
+#define BATADV_NC_NODE_TIMEOUT 10000 /* Milliseconds */
+
 enum batadv_mesh_state {
 	BATADV_MESH_INACTIVE,
 	BATADV_MESH_ACTIVE,
@@ -185,6 +187,7 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);
  * @BATADV_DBG_TT: translation table messages
  * @BATADV_DBG_BLA: bridge loop avoidance messages
  * @BATADV_DBG_DAT: ARP snooping and DAT related messages
+ * @BATADV_DBG_NC: network coding related messages
  * @BATADV_DBG_ALL: the union of all the above log levels
  */
 enum batadv_dbg_level {
@@ -193,7 +196,8 @@ enum batadv_dbg_level {
 	BATADV_DBG_TT	  = BIT(2),
 	BATADV_DBG_BLA    = BIT(3),
 	BATADV_DBG_DAT    = BIT(4),
-	BATADV_DBG_ALL    = 31,
+	BATADV_DBG_NC	  = BIT(5),
+	BATADV_DBG_ALL    = 63,
 };
 
 #ifdef CONFIG_BATMAN_ADV_DEBUG
@@ -298,4 +302,10 @@ static inline uint64_t batadv_sum_counter(struct batadv_priv *bat_priv,
 	return sum;
 }
 
+/* Define a macro to reach the control buffer of the skb. The members of the
+ * control buffer are defined in struct batadv_skb_cb in types.h.
+ * The macro is inspired by the similar macro TCP_SKB_CB() in tcp.h.
+ */
+#define BATADV_SKB_CB(__skb)       ((struct batadv_skb_cb *)&((__skb)->cb[0]))
+
 #endif /* _NET_BATMAN_ADV_MAIN_H_ */

net/batman-adv/network-coding.h

@@ -0,0 +1,123 @@
+/* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
+ *
+ * Martin Hundebøll, Jeppe Ledet-Pedersen
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#ifndef _NET_BATMAN_ADV_NETWORK_CODING_H_
+#define _NET_BATMAN_ADV_NETWORK_CODING_H_
+
+#ifdef CONFIG_BATMAN_ADV_NC
+
+int batadv_nc_init(struct batadv_priv *bat_priv);
+void batadv_nc_free(struct batadv_priv *bat_priv);
+void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
+			      struct batadv_orig_node *orig_node,
+			      struct batadv_orig_node *orig_neigh_node,
+			      struct batadv_ogm_packet *ogm_packet,
+			      int is_single_hop_neigh);
+void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
+			  struct batadv_orig_node *orig_node,
+			  bool (*to_purge)(struct batadv_priv *,
+					   struct batadv_nc_node *));
+void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv);
+void batadv_nc_init_orig(struct batadv_orig_node *orig_node);
+bool batadv_nc_skb_forward(struct sk_buff *skb,
+			   struct batadv_neigh_node *neigh_node,
+			   struct ethhdr *ethhdr);
+void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
+				      struct sk_buff *skb);
+void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
+					 struct sk_buff *skb);
+int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset);
+int batadv_nc_init_debugfs(struct batadv_priv *bat_priv);
+
+#else /* ifdef CONFIG_BATMAN_ADV_NC */
+
+static inline int batadv_nc_init(struct batadv_priv *bat_priv)
+{
+	return 0;
+}
+
+static inline void batadv_nc_free(struct batadv_priv *bat_priv)
+{
+	return;
+}
+
+static inline void
+batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
+			 struct batadv_orig_node *orig_node,
+			 struct batadv_orig_node *orig_neigh_node,
+			 struct batadv_ogm_packet *ogm_packet,
+			 int is_single_hop_neigh)
+{
+	return;
+}
+
+static inline void
+batadv_nc_purge_orig(struct batadv_priv *bat_priv,
+		     struct batadv_orig_node *orig_node,
+		     bool (*to_purge)(struct batadv_priv *,
+				      struct batadv_nc_node *))
+{
+	return;
+}
+
+static inline void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
+{
+	return;
+}
+
+static inline void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
+{
+	return;
+}
+
+static inline bool batadv_nc_skb_forward(struct sk_buff *skb,
+					 struct batadv_neigh_node *neigh_node,
+					 struct ethhdr *ethhdr)
+{
+	return false;
+}
+
+static inline void
+batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
+				 struct sk_buff *skb)
+{
+	return;
+}
+
+static inline void
+batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
+				    struct sk_buff *skb)
+{
+	return;
+}
+
+static inline int batadv_nc_nodes_seq_print_text(struct seq_file *seq,
+						 void *offset)
+{
+	return 0;
+}
+
+static inline int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
+{
+	return 0;
+}
+
+#endif /* ifdef CONFIG_BATMAN_ADV_NC */
+
+#endif /* _NET_BATMAN_ADV_NETWORK_CODING_H_ */

net/batman-adv/originator.c

@@ -28,6 +28,7 @@
 #include "unicast.h"
 #include "soft-interface.h"
 #include "bridge_loop_avoidance.h"
+#include "network-coding.h"
 
 /* hash class keys */
 static struct lock_class_key batadv_orig_hash_lock_class_key;
@@ -142,6 +143,9 @@ static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
 
 	spin_unlock_bh(&orig_node->neigh_list_lock);
 
+	/* Free nc_nodes */
+	batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
+
 	batadv_frag_list_free(&orig_node->frag_list);
 	batadv_tt_global_del_orig(orig_node->bat_priv, orig_node,
 				  "originator timed out");
@@ -219,6 +223,8 @@ struct batadv_orig_node *batadv_get_orig_node(struct batadv_priv *bat_priv,
 	spin_lock_init(&orig_node->neigh_list_lock);
 	spin_lock_init(&orig_node->tt_buff_lock);
 
+	batadv_nc_init_orig(orig_node);
+
 	/* extra reference for return */
 	atomic_set(&orig_node->refcount, 2);
 

net/batman-adv/packet.h

@@ -30,6 +30,7 @@ enum batadv_packettype {
 	BATADV_TT_QUERY		= 0x07,
 	BATADV_ROAM_ADV		= 0x08,
 	BATADV_UNICAST_4ADDR	= 0x09,
+	BATADV_CODED		= 0x0a,
 };
 
 /**
@@ -278,4 +279,36 @@ struct batadv_tt_change {
 	uint8_t addr[ETH_ALEN];
 } __packed;
 
+/**
+ * struct batadv_coded_packet - network coded packet
+ * @header: common batman packet header and ttl of first included packet
+ * @reserved: Align following fields to 2-byte boundaries
+ * @first_source: original source of first included packet
+ * @first_orig_dest: original destinal of first included packet
+ * @first_crc: checksum of first included packet
+ * @first_ttvn: tt-version number of first included packet
+ * @second_ttl: ttl of second packet
+ * @second_dest: second receiver of this coded packet
+ * @second_source: original source of second included packet
+ * @second_orig_dest: original destination of second included packet
+ * @second_crc: checksum of second included packet
+ * @second_ttvn: tt version number of second included packet
+ * @coded_len: length of network coded part of the payload
+ */
+struct batadv_coded_packet {
+	struct batadv_header header;
+	uint8_t  first_ttvn;
+	/* uint8_t  first_dest[ETH_ALEN]; - saved in mac header destination */
+	uint8_t  first_source[ETH_ALEN];
+	uint8_t  first_orig_dest[ETH_ALEN];
+	__be32   first_crc;
+	uint8_t  second_ttl;
+	uint8_t  second_ttvn;
+	uint8_t  second_dest[ETH_ALEN];
+	uint8_t  second_source[ETH_ALEN];
+	uint8_t  second_orig_dest[ETH_ALEN];
+	__be32   second_crc;
+	uint16_t coded_len;
+};
+
 #endif /* _NET_BATMAN_ADV_PACKET_H_ */

net/batman-adv/routing.c

@@ -29,6 +29,7 @@
 #include "unicast.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
+#include "network-coding.h"
 
 static int batadv_route_unicast_packet(struct sk_buff *skb,
 				       struct batadv_hard_iface *recv_if);
@@ -548,27 +549,37 @@ batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
 	return router;
 }
 
+/**
+ * batadv_check_unicast_packet - Check for malformed unicast packets
+ * @skb: packet to check
+ * @hdr_size: size of header to pull
+ *
+ * Check for short header and bad addresses in given packet. Returns negative
+ * value when check fails and 0 otherwise. The negative value depends on the
+ * reason: -ENODATA for bad header, -EBADR for broadcast destination or source,
+ * and -EREMOTE for non-local (other host) destination.
+ */
 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 {
 	struct ethhdr *ethhdr;
 
 	/* drop packet if it has not necessary minimum size */
 	if (unlikely(!pskb_may_pull(skb, hdr_size)))
-		return -1;
+		return -ENODATA;
 
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with unicast indication but broadcast recipient */
 	if (is_broadcast_ether_addr(ethhdr->h_dest))
-		return -1;
+		return -EBADR;
 
 	/* packet with broadcast sender address */
 	if (is_broadcast_ether_addr(ethhdr->h_source))
-		return -1;
+		return -EBADR;
 
 	/* not for me */
 	if (!batadv_is_my_mac(ethhdr->h_dest))
-		return -1;
+		return -EREMOTE;
 
 	return 0;
 }
@@ -850,14 +861,17 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
 	/* decrement ttl */
 	unicast_packet->header.ttl--;
 
+	/* network code packet if possible */
+	if (batadv_nc_skb_forward(skb, neigh_node, ethhdr)) {
+		ret = NET_RX_SUCCESS;
+	} else if (batadv_send_skb_to_orig(skb, orig_node, recv_if)) {
+		ret = NET_RX_SUCCESS;
+
 		/* Update stats counter */
 		batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 		batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
 				   skb->len + ETH_HLEN);
-
+	}
-	/* route it */
-	if (batadv_send_skb_to_orig(skb, orig_node, recv_if))
-		ret = NET_RX_SUCCESS;
 
 out:
 	if (neigh_node)
@@ -1033,7 +1047,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 	struct batadv_unicast_4addr_packet *unicast_4addr_packet;
 	uint8_t *orig_addr;
 	struct batadv_orig_node *orig_node = NULL;
-	int hdr_size = sizeof(*unicast_packet);
+	int check, hdr_size = sizeof(*unicast_packet);
 	bool is4addr;
 
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
@@ -1044,7 +1058,16 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 	if (is4addr)
 		hdr_size = sizeof(*unicast_4addr_packet);
 
-	if (batadv_check_unicast_packet(skb, hdr_size) < 0)
+	/* function returns -EREMOTE for promiscuous packets */
+	check = batadv_check_unicast_packet(skb, hdr_size);
+
+	/* Even though the packet is not for us, we might save it to use for
+	 * decoding a later received coded packet
+	 */
+	if (check == -EREMOTE)
+		batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
+
+	if (check < 0)
 		return NET_RX_DROP;
 
 	if (!batadv_check_unicast_ttvn(bat_priv, skb))

net/batman-adv/send.c

@@ -27,6 +27,7 @@
 #include "vis.h"
 #include "gateway_common.h"
 #include "originator.h"
+#include "network-coding.h"
 
 #include <linux/if_ether.h>
 
@@ -39,6 +40,7 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 			   struct batadv_hard_iface *hard_iface,
 			   const uint8_t *dst_addr)
 {
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 	struct ethhdr *ethhdr;
 
 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
@@ -70,6 +72,9 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 
 	skb->dev = hard_iface->net_dev;
 
+	/* Save a clone of the skb to use when decoding coded packets */
+	batadv_nc_skb_store_for_decoding(bat_priv, skb);
+
 	/* dev_queue_xmit() returns a negative result on error.	 However on
 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 	 * (which is > 0). This will not be treated as an error.

net/batman-adv/soft-interface.c

@@ -37,6 +37,7 @@
 #include <linux/if_ether.h>
 #include "unicast.h"
 #include "bridge_loop_avoidance.h"
+#include "network-coding.h"
 
 
 static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd);
@@ -544,6 +545,8 @@ struct net_device *batadv_softif_create(const char *name)
 	if (ret < 0)
 		goto unreg_soft_iface;
 
+	batadv_nc_init_bat_priv(bat_priv);
+
 	ret = batadv_sysfs_add_meshif(soft_iface);
 	if (ret < 0)
 		goto unreg_soft_iface;
@@ -662,6 +665,17 @@ static const struct {
 	{ "dat_put_rx" },
 	{ "dat_cached_reply_tx" },
 #endif
+#ifdef CONFIG_BATMAN_ADV_NC
+	{ "nc_code" },
+	{ "nc_code_bytes" },
+	{ "nc_recode" },
+	{ "nc_recode_bytes" },
+	{ "nc_buffer" },
+	{ "nc_decode" },
+	{ "nc_decode_bytes" },
+	{ "nc_decode_failed" },
+	{ "nc_sniffed" },
+#endif
 };
 
 static void batadv_get_strings(struct net_device *dev, uint32_t stringset,

net/batman-adv/sysfs.c

@@ -442,6 +442,9 @@ static BATADV_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, batadv_show_gw_bwidth,
 #ifdef CONFIG_BATMAN_ADV_DEBUG
 BATADV_ATTR_SIF_UINT(log_level, S_IRUGO | S_IWUSR, 0, BATADV_DBG_ALL, NULL);
 #endif
+#ifdef CONFIG_BATMAN_ADV_NC
+BATADV_ATTR_SIF_BOOL(network_coding, S_IRUGO | S_IWUSR, NULL);
+#endif
 
 static struct batadv_attribute *batadv_mesh_attrs[] = {
 	&batadv_attr_aggregated_ogms,
@@ -463,6 +466,9 @@ static struct batadv_attribute *batadv_mesh_attrs[] = {
 	&batadv_attr_gw_bandwidth,
 #ifdef CONFIG_BATMAN_ADV_DEBUG
 	&batadv_attr_log_level,
+#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+	&batadv_attr_network_coding,
 #endif
 	NULL,
 };
@@ -688,15 +694,10 @@ int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
 			enum batadv_uev_action action, const char *data)
 {
 	int ret = -ENOMEM;
-	struct batadv_hard_iface *primary_if;
 	struct kobject *bat_kobj;
 	char *uevent_env[4] = { NULL, NULL, NULL, NULL };
 
-	primary_if = batadv_primary_if_get_selected(bat_priv);
+	bat_kobj = &bat_priv->soft_iface->dev.kobj;
-	if (!primary_if)
-		goto out;
-
-	bat_kobj = &primary_if->soft_iface->dev.kobj;
 
 	uevent_env[0] = kmalloc(strlen(BATADV_UEV_TYPE_VAR) +
 				strlen(batadv_uev_type_str[type]) + 1,
@@ -732,9 +733,6 @@ out:
 	kfree(uevent_env[1]);
 	kfree(uevent_env[2]);
 
-	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
-
 	if (ret)
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",

net/batman-adv/translation-table.c

@@ -385,25 +385,19 @@ static void batadv_tt_prepare_packet_buff(struct batadv_priv *bat_priv,
 					  int *packet_buff_len,
 					  int min_packet_len)
 {
-	struct batadv_hard_iface *primary_if;
 	int req_len;
 
-	primary_if = batadv_primary_if_get_selected(bat_priv);
-
 	req_len = min_packet_len;
 	req_len += batadv_tt_len(atomic_read(&bat_priv->tt.local_changes));
 
 	/* if we have too many changes for one packet don't send any
 	 * and wait for the tt table request which will be fragmented
 	 */
-	if ((!primary_if) || (req_len > primary_if->soft_iface->mtu))
+	if (req_len > bat_priv->soft_iface->mtu)
 		req_len = min_packet_len;
 
 	batadv_tt_realloc_packet_buff(packet_buff, packet_buff_len,
 				      min_packet_len, req_len);
-
-	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
 }
 
 static int batadv_tt_changes_fill_buff(struct batadv_priv *bat_priv,
@@ -908,7 +902,7 @@ out_remove:
 	/* remove address from local hash if present */
 	local_flags = batadv_tt_local_remove(bat_priv, tt_addr,
 					     "global tt received",
-					     !!(flags & BATADV_TT_CLIENT_ROAM));
+					     flags & BATADV_TT_CLIENT_ROAM);
 	tt_global_entry->common.flags |= local_flags & BATADV_TT_CLIENT_WIFI;
 
 	if (!(flags & BATADV_TT_CLIENT_ROAM))
@@ -1580,7 +1574,7 @@ static int batadv_tt_global_valid(const void *entry_ptr,
 static struct sk_buff *
 batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
 			      struct batadv_hashtable *hash,
-			      struct batadv_hard_iface *primary_if,
+			      struct batadv_priv *bat_priv,
 			      int (*valid_cb)(const void *, const void *),
 			      void *cb_data)
 {
@@ -1594,8 +1588,8 @@ batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
 	uint32_t i;
 	size_t len;
 
-	if (tt_query_size + tt_len > primary_if->soft_iface->mtu) {
+	if (tt_query_size + tt_len > bat_priv->soft_iface->mtu) {
-		tt_len = primary_if->soft_iface->mtu - tt_query_size;
+		tt_len = bat_priv->soft_iface->mtu - tt_query_size;
 		tt_len -= tt_len % sizeof(struct batadv_tt_change);
 	}
 	tt_tot = tt_len / sizeof(struct batadv_tt_change);
@@ -1715,7 +1709,6 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
 {
 	struct batadv_orig_node *req_dst_orig_node;
 	struct batadv_orig_node *res_dst_orig_node = NULL;
-	struct batadv_hard_iface *primary_if = NULL;
 	uint8_t orig_ttvn, req_ttvn, ttvn;
 	int ret = false;
 	unsigned char *tt_buff;
@@ -1740,10 +1733,6 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
 	if (!res_dst_orig_node)
 		goto out;
 
-	primary_if = batadv_primary_if_get_selected(bat_priv);
-	if (!primary_if)
-		goto out;
-
 	orig_ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
 	req_ttvn = tt_request->ttvn;
 
@@ -1791,7 +1780,7 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
 
 		skb = batadv_tt_response_fill_table(tt_len, ttvn,
 						    bat_priv->tt.global_hash,
-						    primary_if,
+						    bat_priv,
 						    batadv_tt_global_valid,
 						    req_dst_orig_node);
 		if (!skb)
@@ -1828,8 +1817,6 @@ out:
 		batadv_orig_node_free_ref(res_dst_orig_node);
 	if (req_dst_orig_node)
 		batadv_orig_node_free_ref(req_dst_orig_node);
-	if (primary_if)
-		batadv_hardif_free_ref(primary_if);
 	if (!ret)
 		kfree_skb(skb);
 	return ret;
@@ -1907,7 +1894,7 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
 
 		skb = batadv_tt_response_fill_table(tt_len, ttvn,
 						    bat_priv->tt.local_hash,
-						    primary_if,
+						    bat_priv,
 						    batadv_tt_local_valid_entry,
 						    NULL);
 		if (!skb)
@@ -2528,7 +2515,7 @@ bool batadv_tt_global_client_is_roaming(struct batadv_priv *bat_priv,
 	if (!tt_global_entry)
 		goto out;
 
-	ret = !!(tt_global_entry->common.flags & BATADV_TT_CLIENT_ROAM);
+	ret = tt_global_entry->common.flags & BATADV_TT_CLIENT_ROAM;
 	batadv_tt_global_entry_free_ref(tt_global_entry);
 out:
 	return ret;

net/batman-adv/types.h

@@ -128,6 +128,10 @@ struct batadv_hard_iface {
  * @bond_list: list of bonding candidates
  * @refcount: number of contexts the object is used
  * @rcu: struct used for freeing in an RCU-safe manner
+ * @in_coding_list: list of nodes this orig can hear
+ * @out_coding_list: list of nodes that can hear this orig
+ * @in_coding_list_lock: protects in_coding_list
+ * @out_coding_list_lock: protects out_coding_list
  */
 struct batadv_orig_node {
 	uint8_t orig[ETH_ALEN];
@@ -171,6 +175,12 @@ struct batadv_orig_node {
 	struct list_head bond_list;
 	atomic_t refcount;
 	struct rcu_head rcu;
+#ifdef CONFIG_BATMAN_ADV_NC
+	struct list_head in_coding_list;
+	struct list_head out_coding_list;
+	spinlock_t in_coding_list_lock; /* Protects in_coding_list */
+	spinlock_t out_coding_list_lock; /* Protects out_coding_list */
+#endif
 };
 
 /**
@@ -265,6 +275,17 @@ struct batadv_bcast_duplist_entry {
  * @BATADV_CNT_DAT_PUT_RX: received dht PUT traffic packet counter
  * @BATADV_CNT_DAT_CACHED_REPLY_TX: transmitted dat cache reply traffic packet
  *  counter
+ * @BATADV_CNT_NC_CODE: transmitted nc-combined traffic packet counter
+ * @BATADV_CNT_NC_CODE_BYTES: transmitted nc-combined traffic bytes counter
+ * @BATADV_CNT_NC_RECODE: transmitted nc-recombined traffic packet counter
+ * @BATADV_CNT_NC_RECODE_BYTES: transmitted nc-recombined traffic bytes counter
+ * @BATADV_CNT_NC_BUFFER: counter for packets buffered for later nc decoding
+ * @BATADV_CNT_NC_DECODE: received and nc-decoded traffic packet counter
+ * @BATADV_CNT_NC_DECODE_BYTES: received and nc-decoded traffic bytes counter
+ * @BATADV_CNT_NC_DECODE_FAILED: received and decode-failed traffic packet
+ *  counter
+ * @BATADV_CNT_NC_SNIFFED: counter for nc-decoded packets received in promisc
+ *  mode.
  * @BATADV_CNT_NUM: number of traffic counters
  */
 enum batadv_counters {
@@ -291,6 +312,17 @@ enum batadv_counters {
 	BATADV_CNT_DAT_PUT_TX,
 	BATADV_CNT_DAT_PUT_RX,
 	BATADV_CNT_DAT_CACHED_REPLY_TX,
+#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+	BATADV_CNT_NC_CODE,
+	BATADV_CNT_NC_CODE_BYTES,
+	BATADV_CNT_NC_RECODE,
+	BATADV_CNT_NC_RECODE_BYTES,
+	BATADV_CNT_NC_BUFFER,
+	BATADV_CNT_NC_DECODE,
+	BATADV_CNT_NC_DECODE_BYTES,
+	BATADV_CNT_NC_DECODE_FAILED,
+	BATADV_CNT_NC_SNIFFED,
 #endif
 	BATADV_CNT_NUM,
 };
@@ -427,6 +459,35 @@ struct batadv_priv_dat {
 };
 #endif
 
+/**
+ * struct batadv_priv_nc - per mesh interface network coding private data
+ * @work: work queue callback item for cleanup
+ * @debug_dir: dentry for nc subdir in batman-adv directory in debugfs
+ * @min_tq: only consider neighbors for encoding if neigh_tq > min_tq
+ * @max_fwd_delay: maximum packet forward delay to allow coding of packets
+ * @max_buffer_time: buffer time for sniffed packets used to decoding
+ * @timestamp_fwd_flush: timestamp of last forward packet queue flush
+ * @timestamp_sniffed_purge: timestamp of last sniffed packet queue purge
+ * @coding_hash: Hash table used to buffer skbs while waiting for another
+ *  incoming skb to code it with. Skbs are added to the buffer just before being
+ *  forwarded in routing.c
+ * @decoding_hash: Hash table used to buffer skbs that might be needed to decode
+ *  a received coded skb. The buffer is used for 1) skbs arriving on the
+ *  soft-interface; 2) skbs overheard on the hard-interface; and 3) skbs
+ *  forwarded by batman-adv.
+ */
+struct batadv_priv_nc {
+	struct delayed_work work;
+	struct dentry *debug_dir;
+	u8 min_tq;
+	u32 max_fwd_delay;
+	u32 max_buffer_time;
+	unsigned long timestamp_fwd_flush;
+	unsigned long timestamp_sniffed_purge;
+	struct batadv_hashtable *coding_hash;
+	struct batadv_hashtable *decoding_hash;
+};
+
 /**
  * struct batadv_priv - per mesh interface data
  * @mesh_state: current status of the mesh (inactive/active/deactivating)
@@ -470,6 +531,8 @@ struct batadv_priv_dat {
  * @tt: translation table data
  * @vis: vis data
  * @dat: distributed arp table data
+ * @network_coding: bool indicating whether network coding is enabled
+ * @batadv_priv_nc: network coding data
  */
 struct batadv_priv {
 	atomic_t mesh_state;
@@ -522,6 +585,10 @@ struct batadv_priv {
 #ifdef CONFIG_BATMAN_ADV_DAT
 	struct batadv_priv_dat dat;
 #endif
+#ifdef CONFIG_BATMAN_ADV_NC
+	atomic_t network_coding;
+	struct batadv_priv_nc nc;
+#endif /* CONFIG_BATMAN_ADV_NC */
 };
 
 /**
@@ -701,6 +768,75 @@ struct batadv_tt_roam_node {
 	struct list_head list;
 };
 
+/**
+ * struct batadv_nc_node - network coding node
+ * @list: next and prev pointer for the list handling
+ * @addr: the node's mac address
+ * @refcount: number of contexts the object is used by
+ * @rcu: struct used for freeing in an RCU-safe manner
+ * @orig_node: pointer to corresponding orig node struct
+ * @last_seen: timestamp of last ogm received from this node
+ */
+struct batadv_nc_node {
+	struct list_head list;
+	uint8_t addr[ETH_ALEN];
+	atomic_t refcount;
+	struct rcu_head rcu;
+	struct batadv_orig_node *orig_node;
+	unsigned long last_seen;
+};
+
+/**
+ * struct batadv_nc_path - network coding path
+ * @hash_entry: next and prev pointer for the list handling
+ * @rcu: struct used for freeing in an RCU-safe manner
+ * @refcount: number of contexts the object is used by
+ * @packet_list: list of buffered packets for this path
+ * @packet_list_lock: access lock for packet list
+ * @next_hop: next hop (destination) of path
+ * @prev_hop: previous hop (source) of path
+ * @last_valid: timestamp for last validation of path
+ */
+struct batadv_nc_path {
+	struct hlist_node hash_entry;
+	struct rcu_head rcu;
+	atomic_t refcount;
+	struct list_head packet_list;
+	spinlock_t packet_list_lock; /* Protects packet_list */
+	uint8_t next_hop[ETH_ALEN];
+	uint8_t prev_hop[ETH_ALEN];
+	unsigned long last_valid;
+};
+
+/**
+ * struct batadv_nc_packet - network coding packet used when coding and
+ *  decoding packets
+ * @list: next and prev pointer for the list handling
+ * @packet_id: crc32 checksum of skb data
+ * @timestamp: field containing the info when the packet was added to path
+ * @neigh_node: pointer to original next hop neighbor of skb
+ * @skb: skb which can be encoded or used for decoding
+ * @nc_path: pointer to path this nc packet is attached to
+ */
+struct batadv_nc_packet {
+	struct list_head list;
+	__be32 packet_id;
+	unsigned long timestamp;
+	struct batadv_neigh_node *neigh_node;
+	struct sk_buff *skb;
+	struct batadv_nc_path *nc_path;
+};
+
+/**
+ * batadv_skb_cb - control buffer structure used to store private data relevant
+ *  to batman-adv in the skb->cb buffer in skbs.
+ * @decoded: Marks a skb as decoded, which is checked when searching for coding
+ *  opportunities in network-coding.c
+ */
+struct batadv_skb_cb {
+	bool decoded;
+};
+
 /**
  * struct batadv_forw_packet - structure for bcast packets to be sent/forwarded
  * @list: list node for batadv_socket_client::queue_list

net/batman-adv/unicast.c

@@ -122,7 +122,7 @@ batadv_frag_search_packet(struct list_head *head,
 {
 	struct batadv_frag_packet_list_entry *tfp;
 	struct batadv_unicast_frag_packet *tmp_up = NULL;
-	int is_head_tmp, is_head;
+	bool is_head_tmp, is_head;
 	uint16_t search_seqno;
 
 	if (up->flags & BATADV_UNI_FRAG_HEAD)
@@ -130,7 +130,7 @@ batadv_frag_search_packet(struct list_head *head,
 	else
 		search_seqno = ntohs(up->seqno)-1;
 
-	is_head = !!(up->flags & BATADV_UNI_FRAG_HEAD);
+	is_head = up->flags & BATADV_UNI_FRAG_HEAD;
 
 	list_for_each_entry(tfp, head, list) {
 		if (!tfp->skb)
@@ -142,7 +142,7 @@ batadv_frag_search_packet(struct list_head *head,
 		tmp_up = (struct batadv_unicast_frag_packet *)tfp->skb->data;
 
 		if (tfp->seqno == search_seqno) {
-			is_head_tmp = !!(tmp_up->flags & BATADV_UNI_FRAG_HEAD);
+			is_head_tmp = tmp_up->flags & BATADV_UNI_FRAG_HEAD;
 			if (is_head_tmp != is_head)
 				return tfp;
 			else