Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1154 insertions, 0 deletions

diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
new file mode 100644
index 000000000..6baec4e68
--- /dev/null
+++ b/net/batman-adv/bat_v.c
@@ -0,0 +1,1154 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2013-2018  B.A.T.M.A.N. contributors:
+ *
+ * Linus Lüssing, Marek Lindner
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "bat_v.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/cache.h>
+#include <linux/errno.h>
+#include <linux/if_ether.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/seq_file.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
+#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>
+
+#include "bat_algo.h"
+#include "bat_v_elp.h"
+#include "bat_v_ogm.h"
+#include "gateway_client.h"
+#include "gateway_common.h"
+#include "hard-interface.h"
+#include "hash.h"
+#include "log.h"
+#include "netlink.h"
+#include "originator.h"
+
+struct sk_buff;
+
+static void batadv_v_iface_activate(struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+	struct batadv_hard_iface *primary_if;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+
+	if (primary_if) {
+		batadv_v_elp_iface_activate(primary_if, hard_iface);
+		batadv_hardif_put(primary_if);
+	}
+
+	/* B.A.T.M.A.N. V does not use any queuing mechanism, therefore it can
+	 * set the interface as ACTIVE right away, without any risk of race
+	 * condition
+	 */
+	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
+		hard_iface->if_status = BATADV_IF_ACTIVE;
+}
+
+static int batadv_v_iface_enable(struct batadv_hard_iface *hard_iface)
+{
+	int ret;
+
+	ret = batadv_v_elp_iface_enable(hard_iface);
+	if (ret < 0)
+		return ret;
+
+	ret = batadv_v_ogm_iface_enable(hard_iface);
+	if (ret < 0)
+		batadv_v_elp_iface_disable(hard_iface);
+
+	return ret;
+}
+
+static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
+{
+	batadv_v_elp_iface_disable(hard_iface);
+}
+
+static void batadv_v_primary_iface_set(struct batadv_hard_iface *hard_iface)
+{
+	batadv_v_elp_primary_iface_set(hard_iface);
+	batadv_v_ogm_primary_iface_set(hard_iface);
+}
+
+/**
+ * batadv_v_iface_update_mac() - react to hard-interface MAC address change
+ * @hard_iface: the modified interface
+ *
+ * If the modified interface is the primary one, update the originator
+ * address in the ELP and OGM messages to reflect the new MAC address.
+ */
+static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+	struct batadv_hard_iface *primary_if;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+	if (primary_if != hard_iface)
+		goto out;
+
+	batadv_v_primary_iface_set(hard_iface);
+out:
+	if (primary_if)
+		batadv_hardif_put(primary_if);
+}
+
+static void
+batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
+{
+	ewma_throughput_init(&hardif_neigh->bat_v.throughput);
+	INIT_WORK(&hardif_neigh->bat_v.metric_work,
+		  batadv_v_elp_throughput_metric_update);
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+/**
+ * batadv_v_orig_print_neigh() - print neighbors for the originator table
+ * @orig_node: the orig_node for which the neighbors are printed
+ * @if_outgoing: outgoing interface for these entries
+ * @seq: debugfs table seq_file struct
+ *
+ * Must be called while holding an rcu lock.
+ */
+static void
+batadv_v_orig_print_neigh(struct batadv_orig_node *orig_node,
+			  struct batadv_hard_iface *if_outgoing,
+			  struct seq_file *seq)
+{
+	struct batadv_neigh_node *neigh_node;
+	struct batadv_neigh_ifinfo *n_ifinfo;
+
+	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
+		n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+		if (!n_ifinfo)
+			continue;
+
+		seq_printf(seq, " %pM (%9u.%1u)",
+			   neigh_node->addr,
+			   n_ifinfo->bat_v.throughput / 10,
+			   n_ifinfo->bat_v.throughput % 10);
+
+		batadv_neigh_ifinfo_put(n_ifinfo);
+	}
+}
+
+/**
+ * batadv_v_hardif_neigh_print() - print a single ELP neighbour node
+ * @seq: neighbour table seq_file struct
+ * @hardif_neigh: hardif neighbour information
+ */
+static void
+batadv_v_hardif_neigh_print(struct seq_file *seq,
+			    struct batadv_hardif_neigh_node *hardif_neigh)
+{
+	int last_secs, last_msecs;
+	u32 throughput;
+
+	last_secs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) / 1000;
+	last_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) % 1000;
+	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
+
+	seq_printf(seq, "%pM %4i.%03is (%9u.%1u) [%10s]\n",
+		   hardif_neigh->addr, last_secs, last_msecs, throughput / 10,
+		   throughput % 10, hardif_neigh->if_incoming->net_dev->name);
+}
+
+/**
+ * batadv_v_neigh_print() - print the single hop neighbour list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @seq: neighbour table seq_file struct
+ */
+static void batadv_v_neigh_print(struct batadv_priv *bat_priv,
+				 struct seq_file *seq)
+{
+	struct net_device *net_dev = (struct net_device *)seq->private;
+	struct batadv_hardif_neigh_node *hardif_neigh;
+	struct batadv_hard_iface *hard_iface;
+	int batman_count = 0;
+
+	seq_puts(seq,
+		 "  Neighbor        last-seen ( throughput) [        IF]\n");
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+		if (hard_iface->soft_iface != net_dev)
+			continue;
+
+		hlist_for_each_entry_rcu(hardif_neigh,
+					 &hard_iface->neigh_list, list) {
+			batadv_v_hardif_neigh_print(seq, hardif_neigh);
+			batman_count++;
+		}
+	}
+	rcu_read_unlock();
+
+	if (batman_count == 0)
+		seq_puts(seq, "No batman nodes in range ...\n");
+}
+#endif
+
+/**
+ * batadv_v_neigh_dump_neigh() - Dump a neighbour into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @hardif_neigh: Neighbour to dump
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_v_neigh_dump_neigh(struct sk_buff *msg, u32 portid, u32 seq,
+			  struct batadv_hardif_neigh_node *hardif_neigh)
+{
+	void *hdr;
+	unsigned int last_seen_msecs;
+	u32 throughput;
+
+	last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen);
+	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
+	throughput = throughput * 100;
+
+	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, NLM_F_MULTI,
+			  BATADV_CMD_GET_NEIGHBORS);
+	if (!hdr)
+		return -ENOBUFS;
+
+	if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
+		    hardif_neigh->addr) ||
+	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+			hardif_neigh->if_incoming->net_dev->ifindex) ||
+	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
+			last_seen_msecs) ||
+	    nla_put_u32(msg, BATADV_ATTR_THROUGHPUT, throughput))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+	return 0;
+
+ nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+/**
+ * batadv_v_neigh_dump_hardif() - Dump the  neighbours of a hard interface into
+ *  a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @hard_iface: The hard interface to be dumped
+ * @idx_s: Entries to be skipped
+ *
+ * This function assumes the caller holds rcu_read_lock().
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_v_neigh_dump_hardif(struct sk_buff *msg, u32 portid, u32 seq,
+			   struct batadv_priv *bat_priv,
+			   struct batadv_hard_iface *hard_iface,
+			   int *idx_s)
+{
+	struct batadv_hardif_neigh_node *hardif_neigh;
+	int idx = 0;
+
+	hlist_for_each_entry_rcu(hardif_neigh,
+				 &hard_iface->neigh_list, list) {
+		if (idx++ < *idx_s)
+			continue;
+
+		if (batadv_v_neigh_dump_neigh(msg, portid, seq, hardif_neigh)) {
+			*idx_s = idx - 1;
+			return -EMSGSIZE;
+		}
+	}
+
+	*idx_s = 0;
+	return 0;
+}
+
+/**
+ * batadv_v_neigh_dump() - Dump the neighbours of a hard interface  into a
+ *  message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ * @single_hardif: Limit dumping to this hard interface
+ */
+static void
+batadv_v_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb,
+		    struct batadv_priv *bat_priv,
+		    struct batadv_hard_iface *single_hardif)
+{
+	struct batadv_hard_iface *hard_iface;
+	int i_hardif = 0;
+	int i_hardif_s = cb->args[0];
+	int idx = cb->args[1];
+	int portid = NETLINK_CB(cb->skb).portid;
+
+	rcu_read_lock();
+	if (single_hardif) {
+		if (i_hardif_s == 0) {
+			if (batadv_v_neigh_dump_hardif(msg, portid,
+						       cb->nlh->nlmsg_seq,
+						       bat_priv, single_hardif,
+						       &idx) == 0)
+				i_hardif++;
+		}
+	} else {
+		list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+			if (hard_iface->soft_iface != bat_priv->soft_iface)
+				continue;
+
+			if (i_hardif++ < i_hardif_s)
+				continue;
+
+			if (batadv_v_neigh_dump_hardif(msg, portid,
+						       cb->nlh->nlmsg_seq,
+						       bat_priv, hard_iface,
+						       &idx)) {
+				i_hardif--;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	cb->args[0] = i_hardif;
+	cb->args[1] = idx;
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+/**
+ * batadv_v_orig_print() - print the originator table
+ * @bat_priv: the bat priv with all the soft interface information
+ * @seq: debugfs table seq_file struct
+ * @if_outgoing: the outgoing interface for which this should be printed
+ */
+static void batadv_v_orig_print(struct batadv_priv *bat_priv,
+				struct seq_file *seq,
+				struct batadv_hard_iface *if_outgoing)
+{
+	struct batadv_neigh_node *neigh_node;
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	int last_seen_msecs, last_seen_secs;
+	struct batadv_orig_node *orig_node;
+	struct batadv_neigh_ifinfo *n_ifinfo;
+	unsigned long last_seen_jiffies;
+	struct hlist_head *head;
+	int batman_count = 0;
+	u32 i;
+
+	seq_puts(seq,
+		 "  Originator      last-seen ( throughput)           Nexthop [outgoingIF]:   Potential nexthops ...\n");
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+			neigh_node = batadv_orig_router_get(orig_node,
+							    if_outgoing);
+			if (!neigh_node)
+				continue;
+
+			n_ifinfo = batadv_neigh_ifinfo_get(neigh_node,
+							   if_outgoing);
+			if (!n_ifinfo)
+				goto next;
+
+			last_seen_jiffies = jiffies - orig_node->last_seen;
+			last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
+			last_seen_secs = last_seen_msecs / 1000;
+			last_seen_msecs = last_seen_msecs % 1000;
+
+			seq_printf(seq, "%pM %4i.%03is (%9u.%1u) %pM [%10s]:",
+				   orig_node->orig, last_seen_secs,
+				   last_seen_msecs,
+				   n_ifinfo->bat_v.throughput / 10,
+				   n_ifinfo->bat_v.throughput % 10,
+				   neigh_node->addr,
+				   neigh_node->if_incoming->net_dev->name);
+
+			batadv_v_orig_print_neigh(orig_node, if_outgoing, seq);
+			seq_putc(seq, '\n');
+			batman_count++;
+
+next:
+			batadv_neigh_node_put(neigh_node);
+			if (n_ifinfo)
+				batadv_neigh_ifinfo_put(n_ifinfo);
+		}
+		rcu_read_unlock();
+	}
+
+	if (batman_count == 0)
+		seq_puts(seq, "No batman nodes in range ...\n");
+}
+#endif
+
+/**
+ * batadv_v_orig_dump_subentry() - Dump an originator subentry into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @orig_node: Originator to dump
+ * @neigh_node: Single hops neighbour
+ * @best: Is the best originator
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_v_orig_dump_subentry(struct sk_buff *msg, u32 portid, u32 seq,
+			    struct batadv_priv *bat_priv,
+			    struct batadv_hard_iface *if_outgoing,
+			    struct batadv_orig_node *orig_node,
+			    struct batadv_neigh_node *neigh_node,
+			    bool best)
+{
+	struct batadv_neigh_ifinfo *n_ifinfo;
+	unsigned int last_seen_msecs;
+	u32 throughput;
+	void *hdr;
+
+	n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+	if (!n_ifinfo)
+		return 0;
+
+	throughput = n_ifinfo->bat_v.throughput * 100;
+
+	batadv_neigh_ifinfo_put(n_ifinfo);
+
+	last_seen_msecs = jiffies_to_msecs(jiffies - orig_node->last_seen);
+
+	if (if_outgoing != BATADV_IF_DEFAULT &&
+	    if_outgoing != neigh_node->if_incoming)
+		return 0;
+
+	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, NLM_F_MULTI,
+			  BATADV_CMD_GET_ORIGINATORS);
+	if (!hdr)
+		return -ENOBUFS;
+
+	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN, orig_node->orig) ||
+	    nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
+		    neigh_node->addr) ||
+	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+			neigh_node->if_incoming->net_dev->ifindex) ||
+	    nla_put_u32(msg, BATADV_ATTR_THROUGHPUT, throughput) ||
+	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
+			last_seen_msecs))
+		goto nla_put_failure;
+
+	if (best && nla_put_flag(msg, BATADV_ATTR_FLAG_BEST))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+	return 0;
+
+ nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+/**
+ * batadv_v_orig_dump_entry() - Dump an originator entry into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @orig_node: Originator to dump
+ * @sub_s: Number of sub entries to skip
+ *
+ * This function assumes the caller holds rcu_read_lock().
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_v_orig_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+			 struct batadv_priv *bat_priv,
+			 struct batadv_hard_iface *if_outgoing,
+			 struct batadv_orig_node *orig_node, int *sub_s)
+{
+	struct batadv_neigh_node *neigh_node_best;
+	struct batadv_neigh_node *neigh_node;
+	int sub = 0;
+	bool best;
+
+	neigh_node_best = batadv_orig_router_get(orig_node, if_outgoing);
+	if (!neigh_node_best)
+		goto out;
+
+	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
+		if (sub++ < *sub_s)
+			continue;
+
+		best = (neigh_node == neigh_node_best);
+
+		if (batadv_v_orig_dump_subentry(msg, portid, seq, bat_priv,
+						if_outgoing, orig_node,
+						neigh_node, best)) {
+			batadv_neigh_node_put(neigh_node_best);
+
+			*sub_s = sub - 1;
+			return -EMSGSIZE;
+		}
+	}
+
+ out:
+	if (neigh_node_best)
+		batadv_neigh_node_put(neigh_node_best);
+
+	*sub_s = 0;
+	return 0;
+}
+
+/**
+ * batadv_v_orig_dump_bucket() - Dump an originator bucket into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @head: Bucket to be dumped
+ * @idx_s: Number of entries to be skipped
+ * @sub: Number of sub entries to be skipped
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_v_orig_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
+			  struct batadv_priv *bat_priv,
+			  struct batadv_hard_iface *if_outgoing,
+			  struct hlist_head *head, int *idx_s, int *sub)
+{
+	struct batadv_orig_node *orig_node;
+	int idx = 0;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+		if (idx++ < *idx_s)
+			continue;
+
+		if (batadv_v_orig_dump_entry(msg, portid, seq, bat_priv,
+					     if_outgoing, orig_node, sub)) {
+			rcu_read_unlock();
+			*idx_s = idx - 1;
+			return -EMSGSIZE;
+		}
+	}
+	rcu_read_unlock();
+
+	*idx_s = 0;
+	*sub = 0;
+	return 0;
+}
+
+/**
+ * batadv_v_orig_dump() - Dump the originators into a message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ */
+static void
+batadv_v_orig_dump(struct sk_buff *msg, struct netlink_callback *cb,
+		   struct batadv_priv *bat_priv,
+		   struct batadv_hard_iface *if_outgoing)
+{
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	struct hlist_head *head;
+	int bucket = cb->args[0];
+	int idx = cb->args[1];
+	int sub = cb->args[2];
+	int portid = NETLINK_CB(cb->skb).portid;
+
+	while (bucket < hash->size) {
+		head = &hash->table[bucket];
+
+		if (batadv_v_orig_dump_bucket(msg, portid,
+					      cb->nlh->nlmsg_seq,
+					      bat_priv, if_outgoing, head, &idx,
+					      &sub))
+			break;
+
+		bucket++;
+	}
+
+	cb->args[0] = bucket;
+	cb->args[1] = idx;
+	cb->args[2] = sub;
+}
+
+static int batadv_v_neigh_cmp(struct batadv_neigh_node *neigh1,
+			      struct batadv_hard_iface *if_outgoing1,
+			      struct batadv_neigh_node *neigh2,
+			      struct batadv_hard_iface *if_outgoing2)
+{
+	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
+	int ret = 0;
+
+	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
+	if (!ifinfo1)
+		goto err_ifinfo1;
+
+	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+	if (!ifinfo2)
+		goto err_ifinfo2;
+
+	ret = ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;
+
+	batadv_neigh_ifinfo_put(ifinfo2);
+err_ifinfo2:
+	batadv_neigh_ifinfo_put(ifinfo1);
+err_ifinfo1:
+	return ret;
+}
+
+static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
+				  struct batadv_hard_iface *if_outgoing1,
+				  struct batadv_neigh_node *neigh2,
+				  struct batadv_hard_iface *if_outgoing2)
+{
+	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
+	u32 threshold;
+	bool ret = false;
+
+	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
+	if (!ifinfo1)
+		goto err_ifinfo1;
+
+	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+	if (!ifinfo2)
+		goto err_ifinfo2;
+
+	threshold = ifinfo1->bat_v.throughput / 4;
+	threshold = ifinfo1->bat_v.throughput - threshold;
+
+	ret = ifinfo2->bat_v.throughput > threshold;
+
+	batadv_neigh_ifinfo_put(ifinfo2);
+err_ifinfo2:
+	batadv_neigh_ifinfo_put(ifinfo1);
+err_ifinfo1:
+	return ret;
+}
+
+/**
+ * batadv_v_init_sel_class() - initialize GW selection class
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_v_init_sel_class(struct batadv_priv *bat_priv)
+{
+	/* set default throughput difference threshold to 5Mbps */
+	atomic_set(&bat_priv->gw.sel_class, 50);
+}
+
+static ssize_t batadv_v_store_sel_class(struct batadv_priv *bat_priv,
+					char *buff, size_t count)
+{
+	u32 old_class, class;
+
+	if (!batadv_parse_throughput(bat_priv->soft_iface, buff,
+				     "B.A.T.M.A.N. V GW selection class",
+				     &class))
+		return -EINVAL;
+
+	old_class = atomic_read(&bat_priv->gw.sel_class);
+	atomic_set(&bat_priv->gw.sel_class, class);
+
+	if (old_class != class)
+		batadv_gw_reselect(bat_priv);
+
+	return count;
+}
+
+static ssize_t batadv_v_show_sel_class(struct batadv_priv *bat_priv, char *buff)
+{
+	u32 class = atomic_read(&bat_priv->gw.sel_class);
+
+	return sprintf(buff, "%u.%u MBit\n", class / 10, class % 10);
+}
+
+/**
+ * batadv_v_gw_throughput_get() - retrieve the GW-bandwidth for a given GW
+ * @gw_node: the GW to retrieve the metric for
+ * @bw: the pointer where the metric will be stored. The metric is computed as
+ *  the minimum between the GW advertised throughput and the path throughput to
+ *  it in the mesh
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int batadv_v_gw_throughput_get(struct batadv_gw_node *gw_node, u32 *bw)
+{
+	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
+	struct batadv_orig_node *orig_node;
+	struct batadv_neigh_node *router;
+	int ret = -1;
+
+	orig_node = gw_node->orig_node;
+	router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
+	if (!router)
+		goto out;
+
+	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
+	if (!router_ifinfo)
+		goto out;
+
+	/* the GW metric is computed as the minimum between the path throughput
+	 * to reach the GW itself and the advertised bandwidth.
+	 * This gives us an approximation of the effective throughput that the
+	 * client can expect via this particular GW node
+	 */
+	*bw = router_ifinfo->bat_v.throughput;
+	*bw = min_t(u32, *bw, gw_node->bandwidth_down);
+
+	ret = 0;
+out:
+	if (router)
+		batadv_neigh_node_put(router);
+	if (router_ifinfo)
+		batadv_neigh_ifinfo_put(router_ifinfo);
+
+	return ret;
+}
+
+/**
+ * batadv_v_gw_get_best_gw_node() - retrieve the best GW node
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: the GW node having the best GW-metric, NULL if no GW is known
+ */
+static struct batadv_gw_node *
+batadv_v_gw_get_best_gw_node(struct batadv_priv *bat_priv)
+{
+	struct batadv_gw_node *gw_node, *curr_gw = NULL;
+	u32 max_bw = 0, bw;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
+		if (!kref_get_unless_zero(&gw_node->refcount))
+			continue;
+
+		if (batadv_v_gw_throughput_get(gw_node, &bw) < 0)
+			goto next;
+
+		if (curr_gw && bw <= max_bw)
+			goto next;
+
+		if (curr_gw)
+			batadv_gw_node_put(curr_gw);
+
+		curr_gw = gw_node;
+		kref_get(&curr_gw->refcount);
+		max_bw = bw;
+
+next:
+		batadv_gw_node_put(gw_node);
+	}
+	rcu_read_unlock();
+
+	return curr_gw;
+}
+
+/**
+ * batadv_v_gw_is_eligible() - check if a originator would be selected as GW
+ * @bat_priv: the bat priv with all the soft interface information
+ * @curr_gw_orig: originator representing the currently selected GW
+ * @orig_node: the originator representing the new candidate
+ *
+ * Return: true if orig_node can be selected as current GW, false otherwise
+ */
+static bool batadv_v_gw_is_eligible(struct batadv_priv *bat_priv,
+				    struct batadv_orig_node *curr_gw_orig,
+				    struct batadv_orig_node *orig_node)
+{
+	struct batadv_gw_node *curr_gw, *orig_gw = NULL;
+	u32 gw_throughput, orig_throughput, threshold;
+	bool ret = false;
+
+	threshold = atomic_read(&bat_priv->gw.sel_class);
+
+	curr_gw = batadv_gw_node_get(bat_priv, curr_gw_orig);
+	if (!curr_gw) {
+		ret = true;
+		goto out;
+	}
+
+	if (batadv_v_gw_throughput_get(curr_gw, &gw_throughput) < 0) {
+		ret = true;
+		goto out;
+	}
+
+	orig_gw = batadv_gw_node_get(bat_priv, orig_node);
+	if (!orig_gw)
+		goto out;
+
+	if (batadv_v_gw_throughput_get(orig_gw, &orig_throughput) < 0)
+		goto out;
+
+	if (orig_throughput < gw_throughput)
+		goto out;
+
+	if ((orig_throughput - gw_throughput) < threshold)
+		goto out;
+
+	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+		   "Restarting gateway selection: better gateway found (throughput curr: %u, throughput new: %u)\n",
+		   gw_throughput, orig_throughput);
+
+	ret = true;
+out:
+	if (curr_gw)
+		batadv_gw_node_put(curr_gw);
+	if (orig_gw)
+		batadv_gw_node_put(orig_gw);
+
+	return ret;
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+/* fails if orig_node has no router */
+static int batadv_v_gw_write_buffer_text(struct batadv_priv *bat_priv,
+					 struct seq_file *seq,
+					 const struct batadv_gw_node *gw_node)
+{
+	struct batadv_gw_node *curr_gw;
+	struct batadv_neigh_node *router;
+	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
+	int ret = -1;
+
+	router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
+	if (!router)
+		goto out;
+
+	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
+	if (!router_ifinfo)
+		goto out;
+
+	curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
+
+	seq_printf(seq, "%s %pM (%9u.%1u) %pM [%10s]: %u.%u/%u.%u MBit\n",
+		   (curr_gw == gw_node ? "=>" : "  "),
+		   gw_node->orig_node->orig,
+		   router_ifinfo->bat_v.throughput / 10,
+		   router_ifinfo->bat_v.throughput % 10, router->addr,
+		   router->if_incoming->net_dev->name,
+		   gw_node->bandwidth_down / 10,
+		   gw_node->bandwidth_down % 10,
+		   gw_node->bandwidth_up / 10,
+		   gw_node->bandwidth_up % 10);
+	ret = seq_has_overflowed(seq) ? -1 : 0;
+
+	if (curr_gw)
+		batadv_gw_node_put(curr_gw);
+out:
+	if (router_ifinfo)
+		batadv_neigh_ifinfo_put(router_ifinfo);
+	if (router)
+		batadv_neigh_node_put(router);
+	return ret;
+}
+
+/**
+ * batadv_v_gw_print() - print the gateway list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @seq: gateway table seq_file struct
+ */
+static void batadv_v_gw_print(struct batadv_priv *bat_priv,
+			      struct seq_file *seq)
+{
+	struct batadv_gw_node *gw_node;
+	int gw_count = 0;
+
+	seq_puts(seq,
+		 "      Gateway        ( throughput)           Nexthop [outgoingIF]: advertised uplink bandwidth\n");
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
+		/* fails if orig_node has no router */
+		if (batadv_v_gw_write_buffer_text(bat_priv, seq, gw_node) < 0)
+			continue;
+
+		gw_count++;
+	}
+	rcu_read_unlock();
+
+	if (gw_count == 0)
+		seq_puts(seq, "No gateways in range ...\n");
+}
+#endif
+
+/**
+ * batadv_v_gw_dump_entry() - Dump a gateway into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @gw_node: Gateway to be dumped
+ *
+ * Return: Error code, or 0 on success
+ */
+static int batadv_v_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+				  struct batadv_priv *bat_priv,
+				  struct batadv_gw_node *gw_node)
+{
+	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
+	struct batadv_neigh_node *router;
+	struct batadv_gw_node *curr_gw = NULL;
+	int ret = 0;
+	void *hdr;
+
+	router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
+	if (!router)
+		goto out;
+
+	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
+	if (!router_ifinfo)
+		goto out;
+
+	curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
+
+	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+			  NLM_F_MULTI, BATADV_CMD_GET_GATEWAYS);
+	if (!hdr) {
+		ret = -ENOBUFS;
+		goto out;
+	}
+
+	ret = -EMSGSIZE;
+
+	if (curr_gw == gw_node) {
+		if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) {
+			genlmsg_cancel(msg, hdr);
+			goto out;
+		}
+	}
+
+	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
+		    gw_node->orig_node->orig)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	if (nla_put_u32(msg, BATADV_ATTR_THROUGHPUT,
+			router_ifinfo->bat_v.throughput)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	if (nla_put(msg, BATADV_ATTR_ROUTER, ETH_ALEN, router->addr)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	if (nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+			   router->if_incoming->net_dev->name)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	if (nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
+			gw_node->bandwidth_down)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	if (nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP, gw_node->bandwidth_up)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
+
+	genlmsg_end(msg, hdr);
+	ret = 0;
+
+out:
+	if (curr_gw)
+		batadv_gw_node_put(curr_gw);
+	if (router_ifinfo)
+		batadv_neigh_ifinfo_put(router_ifinfo);
+	if (router)
+		batadv_neigh_node_put(router);
+	return ret;
+}
+
+/**
+ * batadv_v_gw_dump() - Dump gateways into a message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ */
+static void batadv_v_gw_dump(struct sk_buff *msg, struct netlink_callback *cb,
+			     struct batadv_priv *bat_priv)
+{
+	int portid = NETLINK_CB(cb->skb).portid;
+	struct batadv_gw_node *gw_node;
+	int idx_skip = cb->args[0];
+	int idx = 0;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
+		if (idx++ < idx_skip)
+			continue;
+
+		if (batadv_v_gw_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
+					   bat_priv, gw_node)) {
+			idx_skip = idx - 1;
+			goto unlock;
+		}
+	}
+
+	idx_skip = idx;
+unlock:
+	rcu_read_unlock();
+
+	cb->args[0] = idx_skip;
+}
+
+static struct batadv_algo_ops batadv_batman_v __read_mostly = {
+	.name = "BATMAN_V",
+	.iface = {
+		.activate = batadv_v_iface_activate,
+		.enable = batadv_v_iface_enable,
+		.disable = batadv_v_iface_disable,
+		.update_mac = batadv_v_iface_update_mac,
+		.primary_set = batadv_v_primary_iface_set,
+	},
+	.neigh = {
+		.hardif_init = batadv_v_hardif_neigh_init,
+		.cmp = batadv_v_neigh_cmp,
+		.is_similar_or_better = batadv_v_neigh_is_sob,
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+		.print = batadv_v_neigh_print,
+#endif
+		.dump = batadv_v_neigh_dump,
+	},
+	.orig = {
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+		.print = batadv_v_orig_print,
+#endif
+		.dump = batadv_v_orig_dump,
+	},
+	.gw = {
+		.init_sel_class = batadv_v_init_sel_class,
+		.store_sel_class = batadv_v_store_sel_class,
+		.show_sel_class = batadv_v_show_sel_class,
+		.get_best_gw_node = batadv_v_gw_get_best_gw_node,
+		.is_eligible = batadv_v_gw_is_eligible,
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+		.print = batadv_v_gw_print,
+#endif
+		.dump = batadv_v_gw_dump,
+	},
+};
+
+/**
+ * batadv_v_hardif_init() - initialize the algorithm specific fields in the
+ *  hard-interface object
+ * @hard_iface: the hard-interface to initialize
+ */
+void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
+{
+	/* enable link throughput auto-detection by setting the throughput
+	 * override to zero
+	 */
+	atomic_set(&hard_iface->bat_v.throughput_override, 0);
+	atomic_set(&hard_iface->bat_v.elp_interval, 500);
+}
+
+/**
+ * batadv_v_mesh_init() - initialize the B.A.T.M.A.N. V private resources for a
+ *  mesh
+ * @bat_priv: the object representing the mesh interface to initialise
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+int batadv_v_mesh_init(struct batadv_priv *bat_priv)
+{
+	int ret = 0;
+
+	ret = batadv_v_ogm_init(bat_priv);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+/**
+ * batadv_v_mesh_free() - free the B.A.T.M.A.N. V private resources for a mesh
+ * @bat_priv: the object representing the mesh interface to free
+ */
+void batadv_v_mesh_free(struct batadv_priv *bat_priv)
+{
+	batadv_v_ogm_free(bat_priv);
+}
+
+/**
+ * batadv_v_init() - B.A.T.M.A.N. V initialization function
+ *
+ * Description: Takes care of initializing all the subcomponents.
+ * It is invoked upon module load only.
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+int __init batadv_v_init(void)
+{
+	int ret;
+
+	/* B.A.T.M.A.N. V echo location protocol packet  */
+	ret = batadv_recv_handler_register(BATADV_ELP,
+					   batadv_v_elp_packet_recv);
+	if (ret < 0)
+		return ret;
+
+	ret = batadv_recv_handler_register(BATADV_OGM2,
+					   batadv_v_ogm_packet_recv);
+	if (ret < 0)
+		goto elp_unregister;
+
+	ret = batadv_algo_register(&batadv_batman_v);
+	if (ret < 0)
+		goto ogm_unregister;
+
+	return ret;
+
+ogm_unregister:
+	batadv_recv_handler_unregister(BATADV_OGM2);
+
+elp_unregister:
+	batadv_recv_handler_unregister(BATADV_ELP);
+
+	return ret;
+}