// SPDX-License-Identifier: GPL-2.0

  /* Copyright (C) 2016-2019  B.A.T.M.A.N. contributors:

   *
   * Matthias Schiffer

   */
  
  #include "netlink.h"
  #include "main.h"

  #include <linux/atomic.h>

  #include <linux/bitops.h>

  #include <linux/bug.h>

  #include <linux/byteorder/generic.h>

  #include <linux/cache.h>

  #include <linux/err.h>

  #include <linux/errno.h>

  #include <linux/export.h>

  #include <linux/genetlink.h>

  #include <linux/gfp.h>

  #include <linux/if_ether.h>

  #include <linux/if_vlan.h>

  #include <linux/init.h>

  #include <linux/kernel.h>

  #include <linux/limits.h>

  #include <linux/list.h>

  #include <linux/netdevice.h>
  #include <linux/netlink.h>

  #include <linux/printk.h>

  #include <linux/rtnetlink.h>

  #include <linux/skbuff.h>

  #include <linux/stddef.h>

  #include <linux/types.h>

  #include <net/genetlink.h>

  #include <net/net_namespace.h>

  #include <net/netlink.h>

  #include <net/sock.h>

  #include <uapi/linux/batadv_packet.h>

  #include <uapi/linux/batman_adv.h>

  #include "bat_algo.h"

  #include "bridge_loop_avoidance.h"

  #include "distributed-arp-table.h"

  #include "gateway_client.h"

  #include "gateway_common.h"

  #include "hard-interface.h"

  #include "log.h"

  #include "multicast.h"

  #include "network-coding.h"

  #include "originator.h"

  #include "soft-interface.h"

  #include "tp_meter.h"

  #include "translation-table.h"

  struct genl_family batadv_netlink_family;

  /* multicast groups */
  enum batadv_netlink_multicast_groups {

  	BATADV_NL_MCGRP_CONFIG,

  	BATADV_NL_MCGRP_TPMETER,
  };

  /**
   * enum batadv_genl_ops_flags - flags for genl_ops's internal_flags
   */
  enum batadv_genl_ops_flags {
  	/**
  	 * @BATADV_FLAG_NEED_MESH: request requires valid soft interface in
  	 *  attribute BATADV_ATTR_MESH_IFINDEX and expects a pointer to it to be
  	 *  saved in info->user_ptr[0]
  	 */
  	BATADV_FLAG_NEED_MESH = BIT(0),

  
  	/**
  	 * @BATADV_FLAG_NEED_HARDIF: request requires valid hard interface in
  	 *  attribute BATADV_ATTR_HARD_IFINDEX and expects a pointer to it to be
  	 *  saved in info->user_ptr[1]
  	 */
  	BATADV_FLAG_NEED_HARDIF = BIT(1),

  
  	/**
  	 * @BATADV_FLAG_NEED_VLAN: request requires valid vlan in
  	 *  attribute BATADV_ATTR_VLANID and expects a pointer to it to be
  	 *  saved in info->user_ptr[1]
  	 */
  	BATADV_FLAG_NEED_VLAN = BIT(2),

  };

  static const struct genl_multicast_group batadv_netlink_mcgrps[] = {

  	[BATADV_NL_MCGRP_CONFIG] = { .name = BATADV_NL_MCAST_GROUP_CONFIG },

  	[BATADV_NL_MCGRP_TPMETER] = { .name = BATADV_NL_MCAST_GROUP_TPMETER },
  };

  static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {

  	[BATADV_ATTR_VERSION]			= { .type = NLA_STRING },
  	[BATADV_ATTR_ALGO_NAME]			= { .type = NLA_STRING },
  	[BATADV_ATTR_MESH_IFINDEX]		= { .type = NLA_U32 },
  	[BATADV_ATTR_MESH_IFNAME]		= { .type = NLA_STRING },
  	[BATADV_ATTR_MESH_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_HARD_IFINDEX]		= { .type = NLA_U32 },
  	[BATADV_ATTR_HARD_IFNAME]		= { .type = NLA_STRING },
  	[BATADV_ATTR_HARD_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_ORIG_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_TPMETER_RESULT]		= { .type = NLA_U8 },
  	[BATADV_ATTR_TPMETER_TEST_TIME]		= { .type = NLA_U32 },
  	[BATADV_ATTR_TPMETER_BYTES]		= { .type = NLA_U64 },
  	[BATADV_ATTR_TPMETER_COOKIE]		= { .type = NLA_U32 },
  	[BATADV_ATTR_ACTIVE]			= { .type = NLA_FLAG },
  	[BATADV_ATTR_TT_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_TT_TTVN]			= { .type = NLA_U8 },
  	[BATADV_ATTR_TT_LAST_TTVN]		= { .type = NLA_U8 },
  	[BATADV_ATTR_TT_CRC32]			= { .type = NLA_U32 },
  	[BATADV_ATTR_TT_VID]			= { .type = NLA_U16 },
  	[BATADV_ATTR_TT_FLAGS]			= { .type = NLA_U32 },
  	[BATADV_ATTR_FLAG_BEST]			= { .type = NLA_FLAG },
  	[BATADV_ATTR_LAST_SEEN_MSECS]		= { .type = NLA_U32 },
  	[BATADV_ATTR_NEIGH_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_TQ]			= { .type = NLA_U8 },
  	[BATADV_ATTR_THROUGHPUT]		= { .type = NLA_U32 },
  	[BATADV_ATTR_BANDWIDTH_UP]		= { .type = NLA_U32 },
  	[BATADV_ATTR_BANDWIDTH_DOWN]		= { .type = NLA_U32 },
  	[BATADV_ATTR_ROUTER]			= { .len = ETH_ALEN },
  	[BATADV_ATTR_BLA_OWN]			= { .type = NLA_FLAG },
  	[BATADV_ATTR_BLA_ADDRESS]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_BLA_VID]			= { .type = NLA_U16 },
  	[BATADV_ATTR_BLA_BACKBONE]		= { .len = ETH_ALEN },
  	[BATADV_ATTR_BLA_CRC]			= { .type = NLA_U16 },
  	[BATADV_ATTR_DAT_CACHE_IP4ADDRESS]	= { .type = NLA_U32 },
  	[BATADV_ATTR_DAT_CACHE_HWADDRESS]	= { .len = ETH_ALEN },
  	[BATADV_ATTR_DAT_CACHE_VID]		= { .type = NLA_U16 },

  	[BATADV_ATTR_MCAST_FLAGS]		= { .type = NLA_U32 },
  	[BATADV_ATTR_MCAST_FLAGS_PRIV]		= { .type = NLA_U32 },

  	[BATADV_ATTR_VLANID]			= { .type = NLA_U16 },

  	[BATADV_ATTR_AGGREGATED_OGMS_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_AP_ISOLATION_ENABLED]	= { .type = NLA_U8 },
  	[BATADV_ATTR_ISOLATION_MARK]		= { .type = NLA_U32 },
  	[BATADV_ATTR_ISOLATION_MASK]		= { .type = NLA_U32 },

  	[BATADV_ATTR_BONDING_ENABLED]		= { .type = NLA_U8 },

  	[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_FRAGMENTATION_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_GW_BANDWIDTH_DOWN]		= { .type = NLA_U32 },
  	[BATADV_ATTR_GW_BANDWIDTH_UP]		= { .type = NLA_U32 },
  	[BATADV_ATTR_GW_MODE]			= { .type = NLA_U8 },
  	[BATADV_ATTR_GW_SEL_CLASS]		= { .type = NLA_U32 },

  	[BATADV_ATTR_HOP_PENALTY]		= { .type = NLA_U8 },

  	[BATADV_ATTR_LOG_LEVEL]			= { .type = NLA_U32 },

  	[BATADV_ATTR_MULTICAST_FORCEFLOOD_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_MULTICAST_FANOUT]		= { .type = NLA_U32 },

  	[BATADV_ATTR_NETWORK_CODING_ENABLED]	= { .type = NLA_U8 },

  	[BATADV_ATTR_ORIG_INTERVAL]		= { .type = NLA_U32 },

  	[BATADV_ATTR_ELP_INTERVAL]		= { .type = NLA_U32 },

  	[BATADV_ATTR_THROUGHPUT_OVERRIDE]	= { .type = NLA_U32 },

  };
  
  /**

   * batadv_netlink_get_ifindex() - Extract an interface index from a message

   * @nlh: Message header
   * @attrtype: Attribute which holds an interface index
   *
   * Return: interface index, or 0.
   */

  int

  batadv_netlink_get_ifindex(const struct nlmsghdr *nlh, int attrtype)
  {
  	struct nlattr *attr = nlmsg_find_attr(nlh, GENL_HDRLEN, attrtype);

  	return (attr && nla_len(attr) == sizeof(u32)) ? nla_get_u32(attr) : 0;

  }
  
  /**

   * batadv_netlink_mesh_fill_ap_isolation() - Add ap_isolation softif attribute
   * @msg: Netlink message to dump into
   * @bat_priv: the bat priv with all the soft interface information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_mesh_fill_ap_isolation(struct sk_buff *msg,
  						 struct batadv_priv *bat_priv)
  {
  	struct batadv_softif_vlan *vlan;
  	u8 ap_isolation;
  
  	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
  	if (!vlan)
  		return 0;
  
  	ap_isolation = atomic_read(&vlan->ap_isolation);
  	batadv_softif_vlan_put(vlan);
  
  	return nla_put_u8(msg, BATADV_ATTR_AP_ISOLATION_ENABLED,
  			  !!ap_isolation);
  }
  
  /**
   * batadv_option_set_ap_isolation() - Set ap_isolation from genl msg
   * @attr: parsed BATADV_ATTR_AP_ISOLATION_ENABLED attribute
   * @bat_priv: the bat priv with all the soft interface information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_set_mesh_ap_isolation(struct nlattr *attr,
  						struct batadv_priv *bat_priv)
  {
  	struct batadv_softif_vlan *vlan;
  
  	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
  	if (!vlan)
  		return -ENOENT;
  
  	atomic_set(&vlan->ap_isolation, !!nla_get_u8(attr));
  	batadv_softif_vlan_put(vlan);
  
  	return 0;
  }
  
  /**

   * batadv_netlink_mesh_fill() - Fill message with mesh attributes
   * @msg: Netlink message to dump into
   * @bat_priv: the bat priv with all the soft interface information
   * @cmd: type of message to generate
   * @portid: Port making netlink request
   * @seq: sequence number for message
   * @flags: Additional flags for message

   *

   * Return: 0 on success or negative error number in case of failure

   */

  static int batadv_netlink_mesh_fill(struct sk_buff *msg,
  				    struct batadv_priv *bat_priv,
  				    enum batadv_nl_commands cmd,
  				    u32 portid, u32 seq, int flags)

  {

  	struct net_device *soft_iface = bat_priv->soft_iface;

  	struct batadv_hard_iface *primary_if = NULL;
  	struct net_device *hard_iface;

  	void *hdr;
  
  	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, flags, cmd);
  	if (!hdr)
  		return -ENOBUFS;

  
  	if (nla_put_string(msg, BATADV_ATTR_VERSION, BATADV_SOURCE_VERSION) ||
  	    nla_put_string(msg, BATADV_ATTR_ALGO_NAME,

  			   bat_priv->algo_ops->name) ||

  	    nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX, soft_iface->ifindex) ||
  	    nla_put_string(msg, BATADV_ATTR_MESH_IFNAME, soft_iface->name) ||
  	    nla_put(msg, BATADV_ATTR_MESH_ADDRESS, ETH_ALEN,

  		    soft_iface->dev_addr) ||
  	    nla_put_u8(msg, BATADV_ATTR_TT_TTVN,
  		       (u8)atomic_read(&bat_priv->tt.vn)))

  		goto nla_put_failure;

  #ifdef CONFIG_BATMAN_ADV_BLA
  	if (nla_put_u16(msg, BATADV_ATTR_BLA_CRC,
  			ntohs(bat_priv->bla.claim_dest.group)))

  		goto nla_put_failure;

  #endif

  	if (batadv_mcast_mesh_info_put(msg, bat_priv))

  		goto nla_put_failure;

  	primary_if = batadv_primary_if_get_selected(bat_priv);
  	if (primary_if && primary_if->if_status == BATADV_IF_ACTIVE) {
  		hard_iface = primary_if->net_dev;
  
  		if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
  				hard_iface->ifindex) ||
  		    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
  				   hard_iface->name) ||
  		    nla_put(msg, BATADV_ATTR_HARD_ADDRESS, ETH_ALEN,
  			    hard_iface->dev_addr))

  			goto nla_put_failure;

  	}

  	if (nla_put_u8(msg, BATADV_ATTR_AGGREGATED_OGMS_ENABLED,
  		       !!atomic_read(&bat_priv->aggregated_ogms)))
  		goto nla_put_failure;

  	if (batadv_netlink_mesh_fill_ap_isolation(msg, bat_priv))
  		goto nla_put_failure;
  
  	if (nla_put_u32(msg, BATADV_ATTR_ISOLATION_MARK,
  			bat_priv->isolation_mark))
  		goto nla_put_failure;
  
  	if (nla_put_u32(msg, BATADV_ATTR_ISOLATION_MASK,
  			bat_priv->isolation_mark_mask))
  		goto nla_put_failure;

  	if (nla_put_u8(msg, BATADV_ATTR_BONDING_ENABLED,
  		       !!atomic_read(&bat_priv->bonding)))
  		goto nla_put_failure;

  #ifdef CONFIG_BATMAN_ADV_BLA
  	if (nla_put_u8(msg, BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED,
  		       !!atomic_read(&bat_priv->bridge_loop_avoidance)))
  		goto nla_put_failure;
  #endif /* CONFIG_BATMAN_ADV_BLA */

  #ifdef CONFIG_BATMAN_ADV_DAT
  	if (nla_put_u8(msg, BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED,
  		       !!atomic_read(&bat_priv->distributed_arp_table)))
  		goto nla_put_failure;
  #endif /* CONFIG_BATMAN_ADV_DAT */

  	if (nla_put_u8(msg, BATADV_ATTR_FRAGMENTATION_ENABLED,
  		       !!atomic_read(&bat_priv->fragmentation)))
  		goto nla_put_failure;

  	if (nla_put_u32(msg, BATADV_ATTR_GW_BANDWIDTH_DOWN,
  			atomic_read(&bat_priv->gw.bandwidth_down)))
  		goto nla_put_failure;
  
  	if (nla_put_u32(msg, BATADV_ATTR_GW_BANDWIDTH_UP,
  			atomic_read(&bat_priv->gw.bandwidth_up)))
  		goto nla_put_failure;
  
  	if (nla_put_u8(msg, BATADV_ATTR_GW_MODE,
  		       atomic_read(&bat_priv->gw.mode)))
  		goto nla_put_failure;
  
  	if (bat_priv->algo_ops->gw.get_best_gw_node &&
  	    bat_priv->algo_ops->gw.is_eligible) {
  		/* GW selection class is not available if the routing algorithm
  		 * in use does not implement the GW API
  		 */
  		if (nla_put_u32(msg, BATADV_ATTR_GW_SEL_CLASS,
  				atomic_read(&bat_priv->gw.sel_class)))
  			goto nla_put_failure;
  	}

  	if (nla_put_u8(msg, BATADV_ATTR_HOP_PENALTY,
  		       atomic_read(&bat_priv->hop_penalty)))
  		goto nla_put_failure;

  #ifdef CONFIG_BATMAN_ADV_DEBUG
  	if (nla_put_u32(msg, BATADV_ATTR_LOG_LEVEL,
  			atomic_read(&bat_priv->log_level)))
  		goto nla_put_failure;
  #endif /* CONFIG_BATMAN_ADV_DEBUG */

  #ifdef CONFIG_BATMAN_ADV_MCAST
  	if (nla_put_u8(msg, BATADV_ATTR_MULTICAST_FORCEFLOOD_ENABLED,
  		       !atomic_read(&bat_priv->multicast_mode)))
  		goto nla_put_failure;

  
  	if (nla_put_u32(msg, BATADV_ATTR_MULTICAST_FANOUT,
  			atomic_read(&bat_priv->multicast_fanout)))
  		goto nla_put_failure;

  #endif /* CONFIG_BATMAN_ADV_MCAST */

  #ifdef CONFIG_BATMAN_ADV_NC
  	if (nla_put_u8(msg, BATADV_ATTR_NETWORK_CODING_ENABLED,
  		       !!atomic_read(&bat_priv->network_coding)))
  		goto nla_put_failure;
  #endif /* CONFIG_BATMAN_ADV_NC */

  	if (nla_put_u32(msg, BATADV_ATTR_ORIG_INTERVAL,
  			atomic_read(&bat_priv->orig_interval)))
  		goto nla_put_failure;

  	if (primary_if)
  		batadv_hardif_put(primary_if);

  	genlmsg_end(msg, hdr);
  	return 0;
  
  nla_put_failure:

  	if (primary_if)
  		batadv_hardif_put(primary_if);

  	genlmsg_cancel(msg, hdr);
  	return -EMSGSIZE;

  }
  
  /**

   * batadv_netlink_notify_mesh() - send softif attributes to listener
   * @bat_priv: the bat priv with all the soft interface information

   *
   * Return: 0 on success, < 0 on error
   */

  int batadv_netlink_notify_mesh(struct batadv_priv *bat_priv)

  {

  	struct sk_buff *msg;

  	int ret;

  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;

  	ret = batadv_netlink_mesh_fill(msg, bat_priv, BATADV_CMD_SET_MESH,
  				       0, 0, 0);
  	if (ret < 0) {
  		nlmsg_free(msg);
  		return ret;

  	}

  	genlmsg_multicast_netns(&batadv_netlink_family,
  				dev_net(bat_priv->soft_iface), msg, 0,
  				BATADV_NL_MCGRP_CONFIG, GFP_KERNEL);

  	return 0;
  }

  /**
   * batadv_netlink_get_mesh() - Get softif attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_get_mesh(struct sk_buff *skb, struct genl_info *info)
  {
  	struct batadv_priv *bat_priv = info->user_ptr[0];
  	struct sk_buff *msg;
  	int ret;

  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;

  	ret = batadv_netlink_mesh_fill(msg, bat_priv, BATADV_CMD_GET_MESH,
  				       info->snd_portid, info->snd_seq, 0);
  	if (ret < 0) {
  		nlmsg_free(msg);

  		return ret;
  	}

  	ret = genlmsg_reply(msg, info);
  
  	return ret;
  }
  
  /**
   * batadv_netlink_set_mesh() - Set softif attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_set_mesh(struct sk_buff *skb, struct genl_info *info)
  {
  	struct batadv_priv *bat_priv = info->user_ptr[0];

  	struct nlattr *attr;
  
  	if (info->attrs[BATADV_ATTR_AGGREGATED_OGMS_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_AGGREGATED_OGMS_ENABLED];
  
  		atomic_set(&bat_priv->aggregated_ogms, !!nla_get_u8(attr));
  	}

  	if (info->attrs[BATADV_ATTR_AP_ISOLATION_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_AP_ISOLATION_ENABLED];
  
  		batadv_netlink_set_mesh_ap_isolation(attr, bat_priv);
  	}
  
  	if (info->attrs[BATADV_ATTR_ISOLATION_MARK]) {
  		attr = info->attrs[BATADV_ATTR_ISOLATION_MARK];
  
  		bat_priv->isolation_mark = nla_get_u32(attr);
  	}
  
  	if (info->attrs[BATADV_ATTR_ISOLATION_MASK]) {
  		attr = info->attrs[BATADV_ATTR_ISOLATION_MASK];
  
  		bat_priv->isolation_mark_mask = nla_get_u32(attr);
  	}

  	if (info->attrs[BATADV_ATTR_BONDING_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_BONDING_ENABLED];
  
  		atomic_set(&bat_priv->bonding, !!nla_get_u8(attr));
  	}

  #ifdef CONFIG_BATMAN_ADV_BLA
  	if (info->attrs[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED];
  
  		atomic_set(&bat_priv->bridge_loop_avoidance,
  			   !!nla_get_u8(attr));
  		batadv_bla_status_update(bat_priv->soft_iface);
  	}
  #endif /* CONFIG_BATMAN_ADV_BLA */

  #ifdef CONFIG_BATMAN_ADV_DAT
  	if (info->attrs[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED];
  
  		atomic_set(&bat_priv->distributed_arp_table,
  			   !!nla_get_u8(attr));
  		batadv_dat_status_update(bat_priv->soft_iface);
  	}
  #endif /* CONFIG_BATMAN_ADV_DAT */

  	if (info->attrs[BATADV_ATTR_FRAGMENTATION_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_FRAGMENTATION_ENABLED];
  
  		atomic_set(&bat_priv->fragmentation, !!nla_get_u8(attr));
  		batadv_update_min_mtu(bat_priv->soft_iface);
  	}

  	if (info->attrs[BATADV_ATTR_GW_BANDWIDTH_DOWN]) {
  		attr = info->attrs[BATADV_ATTR_GW_BANDWIDTH_DOWN];
  
  		atomic_set(&bat_priv->gw.bandwidth_down, nla_get_u32(attr));
  		batadv_gw_tvlv_container_update(bat_priv);
  	}
  
  	if (info->attrs[BATADV_ATTR_GW_BANDWIDTH_UP]) {
  		attr = info->attrs[BATADV_ATTR_GW_BANDWIDTH_UP];
  
  		atomic_set(&bat_priv->gw.bandwidth_up, nla_get_u32(attr));
  		batadv_gw_tvlv_container_update(bat_priv);
  	}
  
  	if (info->attrs[BATADV_ATTR_GW_MODE]) {
  		u8 gw_mode;
  
  		attr = info->attrs[BATADV_ATTR_GW_MODE];
  		gw_mode = nla_get_u8(attr);
  
  		if (gw_mode <= BATADV_GW_MODE_SERVER) {
  			/* Invoking batadv_gw_reselect() is not enough to really
  			 * de-select the current GW. It will only instruct the
  			 * gateway client code to perform a re-election the next
  			 * time that this is needed.
  			 *
  			 * When gw client mode is being switched off the current
  			 * GW must be de-selected explicitly otherwise no GW_ADD
  			 * uevent is thrown on client mode re-activation. This
  			 * is operation is performed in
  			 * batadv_gw_check_client_stop().
  			 */
  			batadv_gw_reselect(bat_priv);
  
  			/* always call batadv_gw_check_client_stop() before
  			 * changing the gateway state
  			 */
  			batadv_gw_check_client_stop(bat_priv);
  			atomic_set(&bat_priv->gw.mode, gw_mode);
  			batadv_gw_tvlv_container_update(bat_priv);
  		}
  	}
  
  	if (info->attrs[BATADV_ATTR_GW_SEL_CLASS] &&
  	    bat_priv->algo_ops->gw.get_best_gw_node &&
  	    bat_priv->algo_ops->gw.is_eligible) {
  		/* setting the GW selection class is allowed only if the routing
  		 * algorithm in use implements the GW API
  		 */
  
  		u32 sel_class_max = 0xffffffffu;
  		u32 sel_class;
  
  		attr = info->attrs[BATADV_ATTR_GW_SEL_CLASS];
  		sel_class = nla_get_u32(attr);
  
  		if (!bat_priv->algo_ops->gw.store_sel_class)
  			sel_class_max = BATADV_TQ_MAX_VALUE;
  
  		if (sel_class >= 1 && sel_class <= sel_class_max) {
  			atomic_set(&bat_priv->gw.sel_class, sel_class);
  			batadv_gw_reselect(bat_priv);
  		}
  	}

  	if (info->attrs[BATADV_ATTR_HOP_PENALTY]) {
  		attr = info->attrs[BATADV_ATTR_HOP_PENALTY];
  
  		atomic_set(&bat_priv->hop_penalty, nla_get_u8(attr));
  	}

  #ifdef CONFIG_BATMAN_ADV_DEBUG
  	if (info->attrs[BATADV_ATTR_LOG_LEVEL]) {
  		attr = info->attrs[BATADV_ATTR_LOG_LEVEL];
  
  		atomic_set(&bat_priv->log_level,
  			   nla_get_u32(attr) & BATADV_DBG_ALL);
  	}
  #endif /* CONFIG_BATMAN_ADV_DEBUG */

  #ifdef CONFIG_BATMAN_ADV_MCAST
  	if (info->attrs[BATADV_ATTR_MULTICAST_FORCEFLOOD_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_MULTICAST_FORCEFLOOD_ENABLED];
  
  		atomic_set(&bat_priv->multicast_mode, !nla_get_u8(attr));
  	}

  
  	if (info->attrs[BATADV_ATTR_MULTICAST_FANOUT]) {
  		attr = info->attrs[BATADV_ATTR_MULTICAST_FANOUT];
  
  		atomic_set(&bat_priv->multicast_fanout, nla_get_u32(attr));
  	}

  #endif /* CONFIG_BATMAN_ADV_MCAST */

  #ifdef CONFIG_BATMAN_ADV_NC
  	if (info->attrs[BATADV_ATTR_NETWORK_CODING_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_NETWORK_CODING_ENABLED];
  
  		atomic_set(&bat_priv->network_coding, !!nla_get_u8(attr));
  		batadv_nc_status_update(bat_priv->soft_iface);
  	}
  #endif /* CONFIG_BATMAN_ADV_NC */

  	if (info->attrs[BATADV_ATTR_ORIG_INTERVAL]) {
  		u32 orig_interval;
  
  		attr = info->attrs[BATADV_ATTR_ORIG_INTERVAL];
  		orig_interval = nla_get_u32(attr);
  
  		orig_interval = min_t(u32, orig_interval, INT_MAX);
  		orig_interval = max_t(u32, orig_interval, 2 * BATADV_JITTER);
  
  		atomic_set(&bat_priv->orig_interval, orig_interval);
  	}

  	batadv_netlink_notify_mesh(bat_priv);
  
  	return 0;

  }

  /**

   * batadv_netlink_tp_meter_put() - Fill information of started tp_meter session

   * @msg: netlink message to be sent back
   * @cookie: tp meter session cookie
   *
   *  Return: 0 on success, < 0 on error
   */
  static int
  batadv_netlink_tp_meter_put(struct sk_buff *msg, u32 cookie)
  {
  	if (nla_put_u32(msg, BATADV_ATTR_TPMETER_COOKIE, cookie))
  		return -ENOBUFS;
  
  	return 0;
  }
  
  /**

   * batadv_netlink_tpmeter_notify() - send tp_meter result via netlink to client

   * @bat_priv: the bat priv with all the soft interface information
   * @dst: destination of tp_meter session
   * @result: reason for tp meter session stop
   * @test_time: total time ot the tp_meter session
   * @total_bytes: bytes acked to the receiver
   * @cookie: cookie of tp_meter session
   *
   * Return: 0 on success, < 0 on error
   */
  int batadv_netlink_tpmeter_notify(struct batadv_priv *bat_priv, const u8 *dst,
  				  u8 result, u32 test_time, u64 total_bytes,
  				  u32 cookie)
  {
  	struct sk_buff *msg;
  	void *hdr;
  	int ret;
  
  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;
  
  	hdr = genlmsg_put(msg, 0, 0, &batadv_netlink_family, 0,
  			  BATADV_CMD_TP_METER);
  	if (!hdr) {
  		ret = -ENOBUFS;
  		goto err_genlmsg;
  	}
  
  	if (nla_put_u32(msg, BATADV_ATTR_TPMETER_COOKIE, cookie))
  		goto nla_put_failure;
  
  	if (nla_put_u32(msg, BATADV_ATTR_TPMETER_TEST_TIME, test_time))
  		goto nla_put_failure;
  
  	if (nla_put_u64_64bit(msg, BATADV_ATTR_TPMETER_BYTES, total_bytes,
  			      BATADV_ATTR_PAD))
  		goto nla_put_failure;
  
  	if (nla_put_u8(msg, BATADV_ATTR_TPMETER_RESULT, result))
  		goto nla_put_failure;
  
  	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN, dst))
  		goto nla_put_failure;
  
  	genlmsg_end(msg, hdr);
  
  	genlmsg_multicast_netns(&batadv_netlink_family,
  				dev_net(bat_priv->soft_iface), msg, 0,
  				BATADV_NL_MCGRP_TPMETER, GFP_KERNEL);
  
  	return 0;
  
  nla_put_failure:
  	genlmsg_cancel(msg, hdr);
  	ret = -EMSGSIZE;
  
  err_genlmsg:
  	nlmsg_free(msg);
  	return ret;
  }
  
  /**

   * batadv_netlink_tp_meter_start() - Start a new tp_meter session

   * @skb: received netlink message
   * @info: receiver information
   *
   * Return: 0 on success, < 0 on error
   */
  static int
  batadv_netlink_tp_meter_start(struct sk_buff *skb, struct genl_info *info)
  {

  	struct batadv_priv *bat_priv = info->user_ptr[0];

  	struct sk_buff *msg = NULL;
  	u32 test_length;
  	void *msg_head;

  	u32 cookie;
  	u8 *dst;
  	int ret;

  	if (!info->attrs[BATADV_ATTR_ORIG_ADDRESS])
  		return -EINVAL;
  
  	if (!info->attrs[BATADV_ATTR_TPMETER_TEST_TIME])
  		return -EINVAL;

  	dst = nla_data(info->attrs[BATADV_ATTR_ORIG_ADDRESS]);
  
  	test_length = nla_get_u32(info->attrs[BATADV_ATTR_TPMETER_TEST_TIME]);

  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg) {
  		ret = -ENOMEM;
  		goto out;
  	}
  
  	msg_head = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  			       &batadv_netlink_family, 0,
  			       BATADV_CMD_TP_METER);
  	if (!msg_head) {
  		ret = -ENOBUFS;
  		goto out;
  	}

  	batadv_tp_start(bat_priv, dst, test_length, &cookie);
  
  	ret = batadv_netlink_tp_meter_put(msg, cookie);
  
   out:

  	if (ret) {
  		if (msg)
  			nlmsg_free(msg);
  		return ret;
  	}
  
  	genlmsg_end(msg, msg_head);
  	return genlmsg_reply(msg, info);
  }
  
  /**

   * batadv_netlink_tp_meter_start() - Cancel a running tp_meter session

   * @skb: received netlink message
   * @info: receiver information
   *
   * Return: 0 on success, < 0 on error
   */
  static int
  batadv_netlink_tp_meter_cancel(struct sk_buff *skb, struct genl_info *info)
  {

  	struct batadv_priv *bat_priv = info->user_ptr[0];

  	u8 *dst;
  	int ret = 0;

  	if (!info->attrs[BATADV_ATTR_ORIG_ADDRESS])
  		return -EINVAL;

  	dst = nla_data(info->attrs[BATADV_ATTR_ORIG_ADDRESS]);

  	batadv_tp_stop(bat_priv, dst, BATADV_TP_REASON_CANCEL);

  	return ret;
  }

  /**

   * batadv_netlink_hardif_fill() - Fill message with hardif attributes

   * @msg: Netlink message to dump into

   * @bat_priv: the bat priv with all the soft interface information
   * @hard_iface: hard interface which was modified
   * @cmd: type of message to generate

   * @portid: Port making netlink request

   * @seq: sequence number for message
   * @flags: Additional flags for message

   * @cb: Control block containing additional options

   *

   * Return: 0 on success or negative error number in case of failure

   */

  static int batadv_netlink_hardif_fill(struct sk_buff *msg,
  				      struct batadv_priv *bat_priv,
  				      struct batadv_hard_iface *hard_iface,
  				      enum batadv_nl_commands cmd,
  				      u32 portid, u32 seq, int flags,
  				      struct netlink_callback *cb)

  {
  	struct net_device *net_dev = hard_iface->net_dev;
  	void *hdr;

  	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, flags, cmd);

  	if (!hdr)

  		return -ENOBUFS;
  
  	if (cb)
  		genl_dump_check_consistent(cb, hdr);

  	if (nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX,
  			bat_priv->soft_iface->ifindex))
  		goto nla_put_failure;

  	if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
  			net_dev->ifindex) ||
  	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
  			   net_dev->name) ||
  	    nla_put(msg, BATADV_ATTR_HARD_ADDRESS, ETH_ALEN,
  		    net_dev->dev_addr))
  		goto nla_put_failure;
  
  	if (hard_iface->if_status == BATADV_IF_ACTIVE) {
  		if (nla_put_flag(msg, BATADV_ATTR_ACTIVE))
  			goto nla_put_failure;
  	}

  #ifdef CONFIG_BATMAN_ADV_BATMAN_V
  	if (nla_put_u32(msg, BATADV_ATTR_ELP_INTERVAL,
  			atomic_read(&hard_iface->bat_v.elp_interval)))
  		goto nla_put_failure;

  
  	if (nla_put_u32(msg, BATADV_ATTR_THROUGHPUT_OVERRIDE,
  			atomic_read(&hard_iface->bat_v.throughput_override)))
  		goto nla_put_failure;

  #endif /* CONFIG_BATMAN_ADV_BATMAN_V */

  	genlmsg_end(msg, hdr);
  	return 0;

  nla_put_failure:

  	genlmsg_cancel(msg, hdr);
  	return -EMSGSIZE;
  }
  
  /**

   * batadv_netlink_notify_hardif() - send hardif attributes to listener
   * @bat_priv: the bat priv with all the soft interface information
   * @hard_iface: hard interface which was modified
   *
   * Return: 0 on success, < 0 on error
   */

  int batadv_netlink_notify_hardif(struct batadv_priv *bat_priv,
  				 struct batadv_hard_iface *hard_iface)

  {
  	struct sk_buff *msg;
  	int ret;
  
  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;
  
  	ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,
  					 BATADV_CMD_SET_HARDIF, 0, 0, 0, NULL);
  	if (ret < 0) {
  		nlmsg_free(msg);
  		return ret;
  	}
  
  	genlmsg_multicast_netns(&batadv_netlink_family,
  				dev_net(bat_priv->soft_iface), msg, 0,
  				BATADV_NL_MCGRP_CONFIG, GFP_KERNEL);
  
  	return 0;
  }
  
  /**
   * batadv_netlink_get_hardif() - Get hardif attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_get_hardif(struct sk_buff *skb,
  				     struct genl_info *info)
  {
  	struct batadv_hard_iface *hard_iface = info->user_ptr[1];
  	struct batadv_priv *bat_priv = info->user_ptr[0];
  	struct sk_buff *msg;
  	int ret;
  
  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;
  
  	ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,
  					 BATADV_CMD_GET_HARDIF,
  					 info->snd_portid, info->snd_seq, 0,
  					 NULL);
  	if (ret < 0) {
  		nlmsg_free(msg);
  		return ret;
  	}
  
  	ret = genlmsg_reply(msg, info);
  
  	return ret;
  }
  
  /**
   * batadv_netlink_set_hardif() - Set hardif attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_set_hardif(struct sk_buff *skb,
  				     struct genl_info *info)
  {
  	struct batadv_hard_iface *hard_iface = info->user_ptr[1];
  	struct batadv_priv *bat_priv = info->user_ptr[0];

  #ifdef CONFIG_BATMAN_ADV_BATMAN_V
  	struct nlattr *attr;
  
  	if (info->attrs[BATADV_ATTR_ELP_INTERVAL]) {
  		attr = info->attrs[BATADV_ATTR_ELP_INTERVAL];
  
  		atomic_set(&hard_iface->bat_v.elp_interval, nla_get_u32(attr));
  	}

  
  	if (info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE]) {
  		attr = info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE];
  
  		atomic_set(&hard_iface->bat_v.throughput_override,
  			   nla_get_u32(attr));
  	}

  #endif /* CONFIG_BATMAN_ADV_BATMAN_V */

  	batadv_netlink_notify_hardif(bat_priv, hard_iface);
  
  	return 0;
  }
  
  /**
   * batadv_netlink_dump_hardif() - Dump all hard interface into a messages

   * @msg: Netlink message to dump into
   * @cb: Parameters from query
   *
   * Return: error code, or length of reply message on success
   */
  static int

  batadv_netlink_dump_hardif(struct sk_buff *msg, struct netlink_callback *cb)

  {
  	struct net *net = sock_net(cb->skb->sk);
  	struct net_device *soft_iface;
  	struct batadv_hard_iface *hard_iface;

  	struct batadv_priv *bat_priv;

  	int ifindex;
  	int portid = NETLINK_CB(cb->skb).portid;

  	int skip = cb->args[0];
  	int i = 0;
  
  	ifindex = batadv_netlink_get_ifindex(cb->nlh,
  					     BATADV_ATTR_MESH_IFINDEX);
  	if (!ifindex)
  		return -EINVAL;
  
  	soft_iface = dev_get_by_index(net, ifindex);
  	if (!soft_iface)
  		return -ENODEV;
  
  	if (!batadv_softif_is_valid(soft_iface)) {
  		dev_put(soft_iface);
  		return -ENODEV;
  	}

  	bat_priv = netdev_priv(soft_iface);

  	rtnl_lock();
  	cb->seq = batadv_hardif_generation << 1 | 1;

  	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {

  		if (hard_iface->soft_iface != soft_iface)
  			continue;
  
  		if (i++ < skip)
  			continue;

  		if (batadv_netlink_hardif_fill(msg, bat_priv, hard_iface,
  					       BATADV_CMD_GET_HARDIF,
  					       portid, cb->nlh->nlmsg_seq,
  					       NLM_F_MULTI, cb)) {

  			i--;
  			break;
  		}
  	}

  	rtnl_unlock();

  
  	dev_put(soft_iface);
  
  	cb->args[0] = i;
  
  	return msg->len;
  }

  /**

   * batadv_netlink_vlan_fill() - Fill message with vlan attributes
   * @msg: Netlink message to dump into
   * @bat_priv: the bat priv with all the soft interface information
   * @vlan: vlan which was modified
   * @cmd: type of message to generate
   * @portid: Port making netlink request
   * @seq: sequence number for message
   * @flags: Additional flags for message
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_vlan_fill(struct sk_buff *msg,
  				    struct batadv_priv *bat_priv,
  				    struct batadv_softif_vlan *vlan,
  				    enum batadv_nl_commands cmd,
  				    u32 portid, u32 seq, int flags)
  {
  	void *hdr;
  
  	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, flags, cmd);
  	if (!hdr)
  		return -ENOBUFS;
  
  	if (nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX,
  			bat_priv->soft_iface->ifindex))
  		goto nla_put_failure;
  
  	if (nla_put_u32(msg, BATADV_ATTR_VLANID, vlan->vid & VLAN_VID_MASK))
  		goto nla_put_failure;

  	if (nla_put_u8(msg, BATADV_ATTR_AP_ISOLATION_ENABLED,
  		       !!atomic_read(&vlan->ap_isolation)))
  		goto nla_put_failure;

  	genlmsg_end(msg, hdr);
  	return 0;
  
  nla_put_failure:
  	genlmsg_cancel(msg, hdr);
  	return -EMSGSIZE;
  }
  
  /**
   * batadv_netlink_notify_vlan() - send vlan attributes to listener
   * @bat_priv: the bat priv with all the soft interface information
   * @vlan: vlan which was modified
   *
   * Return: 0 on success, < 0 on error
   */

  int batadv_netlink_notify_vlan(struct batadv_priv *bat_priv,
  			       struct batadv_softif_vlan *vlan)

  {
  	struct sk_buff *msg;
  	int ret;
  
  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;
  
  	ret = batadv_netlink_vlan_fill(msg, bat_priv, vlan,
  				       BATADV_CMD_SET_VLAN, 0, 0, 0);
  	if (ret < 0) {
  		nlmsg_free(msg);
  		return ret;
  	}
  
  	genlmsg_multicast_netns(&batadv_netlink_family,
  				dev_net(bat_priv->soft_iface), msg, 0,
  				BATADV_NL_MCGRP_CONFIG, GFP_KERNEL);
  
  	return 0;
  }
  
  /**
   * batadv_netlink_get_vlan() - Get vlan attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_get_vlan(struct sk_buff *skb, struct genl_info *info)
  {
  	struct batadv_softif_vlan *vlan = info->user_ptr[1];
  	struct batadv_priv *bat_priv = info->user_ptr[0];
  	struct sk_buff *msg;
  	int ret;
  
  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  	if (!msg)
  		return -ENOMEM;
  
  	ret = batadv_netlink_vlan_fill(msg, bat_priv, vlan, BATADV_CMD_GET_VLAN,
  				       info->snd_portid, info->snd_seq, 0);
  	if (ret < 0) {
  		nlmsg_free(msg);
  		return ret;
  	}
  
  	ret = genlmsg_reply(msg, info);
  
  	return ret;
  }
  
  /**
   * batadv_netlink_set_vlan() - Get vlan attributes
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_netlink_set_vlan(struct sk_buff *skb, struct genl_info *info)
  {
  	struct batadv_softif_vlan *vlan = info->user_ptr[1];
  	struct batadv_priv *bat_priv = info->user_ptr[0];

  	struct nlattr *attr;
  
  	if (info->attrs[BATADV_ATTR_AP_ISOLATION_ENABLED]) {
  		attr = info->attrs[BATADV_ATTR_AP_ISOLATION_ENABLED];
  
  		atomic_set(&vlan->ap_isolation, !!nla_get_u8(attr));
  	}

  
  	batadv_netlink_notify_vlan(bat_priv, vlan);
  
  	return 0;
  }
  
  /**

   * batadv_get_softif_from_info() - Retrieve soft interface from genl attributes
   * @net: the applicable net namespace
   * @info: receiver information
   *
   * Return: Pointer to soft interface (with increased refcnt) on success, error
   *  pointer on error
   */
  static struct net_device *
  batadv_get_softif_from_info(struct net *net, struct genl_info *info)
  {
  	struct net_device *soft_iface;
  	int ifindex;
  
  	if (!info->attrs[BATADV_ATTR_MESH_IFINDEX])
  		return ERR_PTR(-EINVAL);
  
  	ifindex = nla_get_u32(info->attrs[BATADV_ATTR_MESH_IFINDEX]);
  
  	soft_iface = dev_get_by_index(net, ifindex);
  	if (!soft_iface)
  		return ERR_PTR(-ENODEV);
  
  	if (!batadv_softif_is_valid(soft_iface))
  		goto err_put_softif;
  
  	return soft_iface;
  
  err_put_softif:
  	dev_put(soft_iface);
  
  	return ERR_PTR(-EINVAL);
  }
  
  /**

   * batadv_get_hardif_from_info() - Retrieve hardif from genl attributes
   * @bat_priv: the bat priv with all the soft interface information
   * @net: the applicable net namespace
   * @info: receiver information
   *
   * Return: Pointer to hard interface (with increased refcnt) on success, error
   *  pointer on error
   */
  static struct batadv_hard_iface *
  batadv_get_hardif_from_info(struct batadv_priv *bat_priv, struct net *net,
  			    struct genl_info *info)
  {
  	struct batadv_hard_iface *hard_iface;
  	struct net_device *hard_dev;
  	unsigned int hardif_index;
  
  	if (!info->attrs[BATADV_ATTR_HARD_IFINDEX])
  		return ERR_PTR(-EINVAL);
  
  	hardif_index = nla_get_u32(info->attrs[BATADV_ATTR_HARD_IFINDEX]);
  
  	hard_dev = dev_get_by_index(net, hardif_index);
  	if (!hard_dev)
  		return ERR_PTR(-ENODEV);
  
  	hard_iface = batadv_hardif_get_by_netdev(hard_dev);
  	if (!hard_iface)
  		goto err_put_harddev;
  
  	if (hard_iface->soft_iface != bat_priv->soft_iface)
  		goto err_put_hardif;
  
  	/* hard_dev is referenced by hard_iface and not needed here */
  	dev_put(hard_dev);
  
  	return hard_iface;
  
  err_put_hardif:
  	batadv_hardif_put(hard_iface);
  err_put_harddev:
  	dev_put(hard_dev);
  
  	return ERR_PTR(-EINVAL);
  }
  
  /**

   * batadv_get_vlan_from_info() - Retrieve vlan from genl attributes
   * @bat_priv: the bat priv with all the soft interface information
   * @net: the applicable net namespace
   * @info: receiver information
   *
   * Return: Pointer to vlan on success (with increased refcnt), error pointer
   *  on error
   */
  static struct batadv_softif_vlan *
  batadv_get_vlan_from_info(struct batadv_priv *bat_priv, struct net *net,
  			  struct genl_info *info)
  {
  	struct batadv_softif_vlan *vlan;
  	u16 vid;
  
  	if (!info->attrs[BATADV_ATTR_VLANID])
  		return ERR_PTR(-EINVAL);
  
  	vid = nla_get_u16(info->attrs[BATADV_ATTR_VLANID]);
  
  	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
  	if (!vlan)
  		return ERR_PTR(-ENOENT);
  
  	return vlan;
  }
  
  /**

   * batadv_pre_doit() - Prepare batman-adv genl doit request
   * @ops: requested netlink operation
   * @skb: Netlink message with request data
   * @info: receiver information
   *
   * Return: 0 on success or negative error number in case of failure
   */
  static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
  			   struct genl_info *info)
  {
  	struct net *net = genl_info_net(info);

  	struct batadv_hard_iface *hard_iface;
  	struct batadv_priv *bat_priv = NULL;

  	struct batadv_softif_vlan *vlan;

  	struct net_device *soft_iface;

  	u8 user_ptr1_flags;
  	u8 mesh_dep_flags;
  	int ret;

  	user_ptr1_flags = BATADV_FLAG_NEED_HARDIF | BATADV_FLAG_NEED_VLAN;

  	if (WARN_ON(hweight8(ops->internal_flags & user_ptr1_flags) > 1))
  		return -EINVAL;

  	mesh_dep_flags = BATADV_FLAG_NEED_HARDIF | BATADV_FLAG_NEED_VLAN;

  	if (WARN_ON((ops->internal_flags & mesh_dep_flags) &&
  		    (~ops->internal_flags & BATADV_FLAG_NEED_MESH)))
  		return -EINVAL;

  
  	if (ops->internal_flags & BATADV_FLAG_NEED_MESH) {
  		soft_iface = batadv_get_softif_from_info(net, info);
  		if (IS_ERR(soft_iface))
  			return PTR_ERR(soft_iface);
  
  		bat_priv = netdev_priv(soft_iface);
  		info->user_ptr[0] = bat_priv;
  	}

  	if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF) {
  		hard_iface = batadv_get_hardif_from_info(bat_priv, net, info);
  		if (IS_ERR(hard_iface)) {
  			ret = PTR_ERR(hard_iface);
  			goto err_put_softif;
  		}
  
  		info->user_ptr[1] = hard_iface;
  	}

  	if (ops->internal_flags & BATADV_FLAG_NEED_VLAN) {
  		vlan = batadv_get_vlan_from_info(bat_priv, net, info);
  		if (IS_ERR(vlan)) {
  			ret = PTR_ERR(vlan);
  			goto err_put_softif;
  		}
  
  		info->user_ptr[1] = vlan;
  	}

  	return 0;

  
  err_put_softif:
  	if (bat_priv)
  		dev_put(bat_priv->soft_iface);
  
  	return ret;

  }
  
  /**
   * batadv_post_doit() - End batman-adv genl doit request
   * @ops: requested netlink operation
   * @skb: Netlink message with request data
   * @info: receiver information
   */
  static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb,
  			     struct genl_info *info)
  {

  	struct batadv_hard_iface *hard_iface;

  	struct batadv_softif_vlan *vlan;

  	struct batadv_priv *bat_priv;

  	if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF &&
  	    info->user_ptr[1]) {
  		hard_iface = info->user_ptr[1];
  
  		batadv_hardif_put(hard_iface);
  	}

  	if (ops->internal_flags & BATADV_FLAG_NEED_VLAN && info->user_ptr[1]) {
  		vlan = info->user_ptr[1];
  		batadv_softif_vlan_put(vlan);
  	}

  	if (ops->internal_flags & BATADV_FLAG_NEED_MESH && info->user_ptr[0]) {
  		bat_priv = info->user_ptr[0];
  		dev_put(bat_priv->soft_iface);
  	}
  }

  static const struct genl_ops batadv_netlink_ops[] = {

  	{

  		.cmd = BATADV_CMD_GET_MESH,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		/* can be retrieved by unprivileged users */

  		.doit = batadv_netlink_get_mesh,
  		.internal_flags = BATADV_FLAG_NEED_MESH,

  	},

  	{
  		.cmd = BATADV_CMD_TP_METER,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.doit = batadv_netlink_tp_meter_start,

  		.internal_flags = BATADV_FLAG_NEED_MESH,

  	},
  	{
  		.cmd = BATADV_CMD_TP_METER_CANCEL,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.doit = batadv_netlink_tp_meter_cancel,

  		.internal_flags = BATADV_FLAG_NEED_MESH,

  	},

  	{
  		.cmd = BATADV_CMD_GET_ROUTING_ALGOS,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_algo_dump,
  	},

  	{

  		.cmd = BATADV_CMD_GET_HARDIF,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		/* can be retrieved by unprivileged users */

  		.dumpit = batadv_netlink_dump_hardif,
  		.doit = batadv_netlink_get_hardif,
  		.internal_flags = BATADV_FLAG_NEED_MESH |
  				  BATADV_FLAG_NEED_HARDIF,

  	},

  	{
  		.cmd = BATADV_CMD_GET_TRANSTABLE_LOCAL,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_tt_local_dump,
  	},
  	{
  		.cmd = BATADV_CMD_GET_TRANSTABLE_GLOBAL,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_tt_global_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_ORIGINATORS,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_orig_dump,
  	},
  	{
  		.cmd = BATADV_CMD_GET_NEIGHBORS,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_hardif_neigh_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_GATEWAYS,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_gw_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_BLA_CLAIM,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_bla_claim_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_BLA_BACKBONE,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_bla_backbone_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_DAT_CACHE,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_dat_cache_dump,
  	},

  	{
  		.cmd = BATADV_CMD_GET_MCAST_FLAGS,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.dumpit = batadv_mcast_flags_dump,
  	},

  	{
  		.cmd = BATADV_CMD_SET_MESH,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.doit = batadv_netlink_set_mesh,
  		.internal_flags = BATADV_FLAG_NEED_MESH,
  	},

  	{
  		.cmd = BATADV_CMD_SET_HARDIF,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.doit = batadv_netlink_set_hardif,
  		.internal_flags = BATADV_FLAG_NEED_MESH |
  				  BATADV_FLAG_NEED_HARDIF,
  	},

  	{
  		.cmd = BATADV_CMD_GET_VLAN,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		/* can be retrieved by unprivileged users */

  		.doit = batadv_netlink_get_vlan,
  		.internal_flags = BATADV_FLAG_NEED_MESH |
  				  BATADV_FLAG_NEED_VLAN,
  	},
  	{
  		.cmd = BATADV_CMD_SET_VLAN,

  		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

  		.flags = GENL_ADMIN_PERM,

  		.doit = batadv_netlink_set_vlan,
  		.internal_flags = BATADV_FLAG_NEED_MESH |
  				  BATADV_FLAG_NEED_VLAN,
  	},

  };

  struct genl_family batadv_netlink_family __ro_after_init = {

  	.hdrsize = 0,
  	.name = BATADV_NL_NAME,
  	.version = 1,
  	.maxattr = BATADV_ATTR_MAX,

  	.policy = batadv_netlink_policy,

  	.netnsok = true,

  	.pre_doit = batadv_pre_doit,
  	.post_doit = batadv_post_doit,

  	.module = THIS_MODULE,
  	.ops = batadv_netlink_ops,
  	.n_ops = ARRAY_SIZE(batadv_netlink_ops),
  	.mcgrps = batadv_netlink_mcgrps,
  	.n_mcgrps = ARRAY_SIZE(batadv_netlink_mcgrps),
  };

  /**

   * batadv_netlink_register() - register batadv genl netlink family

   */
  void __init batadv_netlink_register(void)
  {
  	int ret;

  	ret = genl_register_family(&batadv_netlink_family);

  	if (ret)
  		pr_warn("unable to register netlink family");
  }
  
  /**

   * batadv_netlink_unregister() - unregister batadv genl netlink family

   */
  void batadv_netlink_unregister(void)
  {
  	genl_unregister_family(&batadv_netlink_family);
  }