net/batman-adv/tvlv.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner, Simon Wunderlich
  */

 #include "main.h"

 #include <linux/byteorder/generic.h>
 #include <linux/etherdevice.h>
 #include <linux/gfp.h>
 #include <linux/if_ether.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/pkt_sched.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/stddef.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <uapi/linux/batadv_packet.h>

 #include "originator.h"
 #include "send.h"
 #include "tvlv.h"

 /**
  * batadv_tvlv_handler_release() - release tvlv handler from lists and queue for
  *  free after rcu grace period
  * @ref: kref pointer of the tvlv
  */
 static void batadv_tvlv_handler_release(struct kref *ref)
 {
 	struct batadv_tvlv_handler *tvlv_handler;

 	tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount);
 	kfree_rcu(tvlv_handler, rcu);
 }

 /**
  * batadv_tvlv_handler_put() - decrement the tvlv container refcounter and
  *  possibly release it
  * @tvlv_handler: the tvlv handler to free
  */
 static void batadv_tvlv_handler_put(struct batadv_tvlv_handler *tvlv_handler)
 {
 	kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release);
 }

 /**
  * batadv_tvlv_handler_get() - retrieve tvlv handler from the tvlv handler list
  *  based on the provided type and version (both need to match)
  * @bat_priv: the bat priv with all the soft interface information
  * @type: tvlv handler type to look for
  * @version: tvlv handler version to look for
  *
  * Return: tvlv handler if found or NULL otherwise.
  */
 static struct batadv_tvlv_handler *
 batadv_tvlv_handler_get(struct batadv_priv *bat_priv, u8 type, u8 version)
 {
 	struct batadv_tvlv_handler *tvlv_handler_tmp, *tvlv_handler = NULL;

 	rcu_read_lock();
 	hlist_for_each_entry_rcu(tvlv_handler_tmp,
 				 &bat_priv->tvlv.handler_list, list) {
 		if (tvlv_handler_tmp->type != type)
 			continue;

 		if (tvlv_handler_tmp->version != version)
 			continue;

 		if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount))
 			continue;

 		tvlv_handler = tvlv_handler_tmp;
 		break;
 	}
 	rcu_read_unlock();

 	return tvlv_handler;
 }

 /**
  * batadv_tvlv_container_release() - release tvlv from lists and free
  * @ref: kref pointer of the tvlv
  */
 static void batadv_tvlv_container_release(struct kref *ref)
 {
 	struct batadv_tvlv_container *tvlv;

 	tvlv = container_of(ref, struct batadv_tvlv_container, refcount);
 	kfree(tvlv);
 }

 /**
  * batadv_tvlv_container_put() - decrement the tvlv container refcounter and
  *  possibly release it
  * @tvlv: the tvlv container to free
  */
 static void batadv_tvlv_container_put(struct batadv_tvlv_container *tvlv)
 {
 	kref_put(&tvlv->refcount, batadv_tvlv_container_release);
 }

 /**
  * batadv_tvlv_container_get() - retrieve tvlv container from the tvlv container
  *  list based on the provided type and version (both need to match)
  * @bat_priv: the bat priv with all the soft interface information
  * @type: tvlv container type to look for
  * @version: tvlv container version to look for
  *
  * Has to be called with the appropriate locks being acquired
  * (tvlv.container_list_lock).
  *
  * Return: tvlv container if found or NULL otherwise.
  */
 static struct batadv_tvlv_container *
 batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version)
 {
 	struct batadv_tvlv_container *tvlv_tmp, *tvlv = NULL;

 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

 	hlist_for_each_entry(tvlv_tmp, &bat_priv->tvlv.container_list, list) {
 		if (tvlv_tmp->tvlv_hdr.type != type)
 			continue;

 		if (tvlv_tmp->tvlv_hdr.version != version)
 			continue;

 		kref_get(&tvlv_tmp->refcount);
 		tvlv = tvlv_tmp;
 		break;
 	}

 	return tvlv;
 }

 /**
  * batadv_tvlv_container_list_size() - calculate the size of the tvlv container
  *  list entries
  * @bat_priv: the bat priv with all the soft interface information
  *
  * Has to be called with the appropriate locks being acquired
  * (tvlv.container_list_lock).
  *
  * Return: size of all currently registered tvlv containers in bytes.
  */
 static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
 {
 	struct batadv_tvlv_container *tvlv;
 	u16 tvlv_len = 0;

 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

 	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
 		tvlv_len += sizeof(struct batadv_tvlv_hdr);
 		tvlv_len += ntohs(tvlv->tvlv_hdr.len);
 	}

 	return tvlv_len;
 }

 /**
  * batadv_tvlv_container_remove() - remove tvlv container from the tvlv
  *  container list
  * @bat_priv: the bat priv with all the soft interface information
  * @tvlv: the to be removed tvlv container
  *
  * Has to be called with the appropriate locks being acquired
  * (tvlv.container_list_lock).
  */
 static void batadv_tvlv_container_remove(struct batadv_priv *bat_priv,
 					 struct batadv_tvlv_container *tvlv)
 {
 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

 	if (!tvlv)
 		return;

 	hlist_del(&tvlv->list);

 	/* first call to decrement the counter, second call to free */
 	batadv_tvlv_container_put(tvlv);
 	batadv_tvlv_container_put(tvlv);
 }

 /**
  * batadv_tvlv_container_unregister() - unregister tvlv container based on the
  *  provided type and version (both need to match)
  * @bat_priv: the bat priv with all the soft interface information
  * @type: tvlv container type to unregister
  * @version: tvlv container type to unregister
  */
 void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
 				      u8 type, u8 version)
 {
 	struct batadv_tvlv_container *tvlv;

 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
 	tvlv = batadv_tvlv_container_get(bat_priv, type, version);
 	batadv_tvlv_container_remove(bat_priv, tvlv);
 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
 }

 /**
  * batadv_tvlv_container_register() - register tvlv type, version and content
  *  to be propagated with each (primary interface) OGM
  * @bat_priv: the bat priv with all the soft interface information
  * @type: tvlv container type
  * @version: tvlv container version
  * @tvlv_value: tvlv container content
  * @tvlv_value_len: tvlv container content length
  *
  * If a container of the same type and version was already registered the new
  * content is going to replace the old one.
  */
 void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
 				    u8 type, u8 version,
 				    void *tvlv_value, u16 tvlv_value_len)
 {
 	struct batadv_tvlv_container *tvlv_old, *tvlv_new;

 	if (!tvlv_value)
 		tvlv_value_len = 0;

 	tvlv_new = kzalloc(sizeof(*tvlv_new) + tvlv_value_len, GFP_ATOMIC);
 	if (!tvlv_new)
 		return;

 	tvlv_new->tvlv_hdr.version = version;
 	tvlv_new->tvlv_hdr.type = type;
 	tvlv_new->tvlv_hdr.len = htons(tvlv_value_len);

 	memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len));
 	INIT_HLIST_NODE(&tvlv_new->list);
 	kref_init(&tvlv_new->refcount);

 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
 	tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
 	batadv_tvlv_container_remove(bat_priv, tvlv_old);

 	kref_get(&tvlv_new->refcount);
 	hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);

 	/* don't return reference to new tvlv_container */
 	batadv_tvlv_container_put(tvlv_new);
 }

 /**
  * batadv_tvlv_realloc_packet_buff() - reallocate packet buffer to accommodate
  *  requested packet size
  * @packet_buff: packet buffer
  * @packet_buff_len: packet buffer size
  * @min_packet_len: requested packet minimum size
  * @additional_packet_len: requested additional packet size on top of minimum
  *  size
  *
  * Return: true of the packet buffer could be changed to the requested size,
  * false otherwise.
  */
 static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff,
 					    int *packet_buff_len,
 					    int min_packet_len,
 					    int additional_packet_len)
 {
 	unsigned char *new_buff;

 	new_buff = kmalloc(min_packet_len + additional_packet_len, GFP_ATOMIC);

 	/* keep old buffer if kmalloc should fail */
 	if (!new_buff)
 		return false;

 	memcpy(new_buff, *packet_buff, min_packet_len);
 	kfree(*packet_buff);
 	*packet_buff = new_buff;
 	*packet_buff_len = min_packet_len + additional_packet_len;

 	return true;
 }

 /**
  * batadv_tvlv_container_ogm_append() - append tvlv container content to given
  *  OGM packet buffer
  * @bat_priv: the bat priv with all the soft interface information
  * @packet_buff: ogm packet buffer
  * @packet_buff_len: ogm packet buffer size including ogm header and tvlv
  *  content
  * @packet_min_len: ogm header size to be preserved for the OGM itself
  *
  * The ogm packet might be enlarged or shrunk depending on the current size
  * and the size of the to-be-appended tvlv containers.
  *
  * Return: size of all appended tvlv containers in bytes.
  */
 u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
 				     unsigned char **packet_buff,
 				     int *packet_buff_len, int packet_min_len)
 {
 	struct batadv_tvlv_container *tvlv;
 	struct batadv_tvlv_hdr *tvlv_hdr;
 	u16 tvlv_value_len;
 	void *tvlv_value;
 	bool ret;

 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
 	tvlv_value_len = batadv_tvlv_container_list_size(bat_priv);

 	ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len,
 					      packet_min_len, tvlv_value_len);

 	if (!ret)
 		goto end;

 	if (!tvlv_value_len)
 		goto end;

 	tvlv_value = (*packet_buff) + packet_min_len;

 	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
 		tvlv_hdr = tvlv_value;
 		tvlv_hdr->type = tvlv->tvlv_hdr.type;
 		tvlv_hdr->version = tvlv->tvlv_hdr.version;
 		tvlv_hdr->len = tvlv->tvlv_hdr.len;
 		tvlv_value = tvlv_hdr + 1;
 		memcpy(tvlv_value, tvlv + 1, ntohs(tvlv->tvlv_hdr.len));
 		tvlv_value = (u8 *)tvlv_value + ntohs(tvlv->tvlv_hdr.len);
 	}

 end:
 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
 	return tvlv_value_len;
 }

 /**
  * batadv_tvlv_call_handler() - parse the given tvlv buffer to call the
  *  appropriate handlers
  * @bat_priv: the bat priv with all the soft interface information
  * @tvlv_handler: tvlv callback function handling the tvlv content
  * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
  * @orig_node: orig node emitting the ogm packet
  * @src: source mac address of the unicast packet
  * @dst: destination mac address of the unicast packet
  * @tvlv_value: tvlv content
  * @tvlv_value_len: tvlv content length
  *
  * Return: success if handler was not found or the return value of the handler
  * callback.
  */
 static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv,
 				    struct batadv_tvlv_handler *tvlv_handler,
 				    bool ogm_source,
 				    struct batadv_orig_node *orig_node,
 				    u8 *src, u8 *dst,
 				    void *tvlv_value, u16 tvlv_value_len)
 {
 	if (!tvlv_handler)
 		return NET_RX_SUCCESS;

 	if (ogm_source) {
 		if (!tvlv_handler->ogm_handler)
 			return NET_RX_SUCCESS;

 		if (!orig_node)
 			return NET_RX_SUCCESS;

 		tvlv_handler->ogm_handler(bat_priv, orig_node,
 					  BATADV_NO_FLAGS,
 					  tvlv_value, tvlv_value_len);
 		tvlv_handler->flags |= BATADV_TVLV_HANDLER_OGM_CALLED;
 	} else {
 		if (!src)
 			return NET_RX_SUCCESS;

 		if (!dst)
 			return NET_RX_SUCCESS;

 		if (!tvlv_handler->unicast_handler)
 			return NET_RX_SUCCESS;

 		return tvlv_handler->unicast_handler(bat_priv, src,
 						     dst, tvlv_value,
 						     tvlv_value_len);
 	}

 	return NET_RX_SUCCESS;
 }

 /**
  * batadv_tvlv_containers_process() - parse the given tvlv buffer to call the
  *  appropriate handlers
  * @bat_priv: the bat priv with all the soft interface information
  * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
  * @orig_node: orig node emitting the ogm packet
  * @src: source mac address of the unicast packet
  * @dst: destination mac address of the unicast packet
  * @tvlv_value: tvlv content
  * @tvlv_value_len: tvlv content length
  *
  * Return: success when processing an OGM or the return value of all called
  * handler callbacks.
  */
 int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
 				   bool ogm_source,
 				   struct batadv_orig_node *orig_node,
 				   u8 *src, u8 *dst,
 				   void *tvlv_value, u16 tvlv_value_len)
 {
 	struct batadv_tvlv_handler *tvlv_handler;
 	struct batadv_tvlv_hdr *tvlv_hdr;
 	u16 tvlv_value_cont_len;
 	u8 cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
 	int ret = NET_RX_SUCCESS;

 	while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
 		tvlv_hdr = tvlv_value;
 		tvlv_value_cont_len = ntohs(tvlv_hdr->len);
 		tvlv_value = tvlv_hdr + 1;
 		tvlv_value_len -= sizeof(*tvlv_hdr);

 		if (tvlv_value_cont_len > tvlv_value_len)
 			break;

 		tvlv_handler = batadv_tvlv_handler_get(bat_priv,
 						       tvlv_hdr->type,
 						       tvlv_hdr->version);

 		ret |= batadv_tvlv_call_handler(bat_priv, tvlv_handler,
 						ogm_source, orig_node,
 						src, dst, tvlv_value,
 						tvlv_value_cont_len);
 		if (tvlv_handler)
 			batadv_tvlv_handler_put(tvlv_handler);
 		tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len;
 		tvlv_value_len -= tvlv_value_cont_len;
 	}

 	if (!ogm_source)
 		return ret;

 	rcu_read_lock();
 	hlist_for_each_entry_rcu(tvlv_handler,
 				 &bat_priv->tvlv.handler_list, list) {
 		if ((tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
 		    !(tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CALLED))
 			tvlv_handler->ogm_handler(bat_priv, orig_node,
 						  cifnotfound, NULL, 0);

 		tvlv_handler->flags &= ~BATADV_TVLV_HANDLER_OGM_CALLED;
 	}
 	rcu_read_unlock();

 	return NET_RX_SUCCESS;
 }

 /**
  * batadv_tvlv_ogm_receive() - process an incoming ogm and call the appropriate
  *  handlers
  * @bat_priv: the bat priv with all the soft interface information
  * @batadv_ogm_packet: ogm packet containing the tvlv containers
  * @orig_node: orig node emitting the ogm packet
  */
 void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
 			     struct batadv_ogm_packet *batadv_ogm_packet,
 			     struct batadv_orig_node *orig_node)
 {
 	void *tvlv_value;
 	u16 tvlv_value_len;

 	if (!batadv_ogm_packet)
 		return;

 	tvlv_value_len = ntohs(batadv_ogm_packet->tvlv_len);
 	if (!tvlv_value_len)
 		return;

 	tvlv_value = batadv_ogm_packet + 1;

 	batadv_tvlv_containers_process(bat_priv, true, orig_node, NULL, NULL,
 				       tvlv_value, tvlv_value_len);
 }

 /**
  * batadv_tvlv_handler_register() - register tvlv handler based on the provided
  *  type and version (both need to match) for ogm tvlv payload and/or unicast
  *  payload
  * @bat_priv: the bat priv with all the soft interface information
  * @optr: ogm tvlv handler callback function. This function receives the orig
  *  node, flags and the tvlv content as argument to process.
  * @uptr: unicast tvlv handler callback function. This function receives the
  *  source & destination of the unicast packet as well as the tvlv content
  *  to process.
  * @type: tvlv handler type to be registered
  * @version: tvlv handler version to be registered
  * @flags: flags to enable or disable TVLV API behavior
  */
 void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
 				  void (*optr)(struct batadv_priv *bat_priv,
 					       struct batadv_orig_node *orig,
 					       u8 flags,
 					       void *tvlv_value,
 					       u16 tvlv_value_len),
 				  int (*uptr)(struct batadv_priv *bat_priv,
 					      u8 *src, u8 *dst,
 					      void *tvlv_value,
 					      u16 tvlv_value_len),
 				  u8 type, u8 version, u8 flags)
 {
 	struct batadv_tvlv_handler *tvlv_handler;

 	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);

 	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
 	if (tvlv_handler) {
 		spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
 		batadv_tvlv_handler_put(tvlv_handler);
 		return;
 	}

 	tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
 	if (!tvlv_handler) {
 		spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
 		return;
 	}

 	tvlv_handler->ogm_handler = optr;
 	tvlv_handler->unicast_handler = uptr;
 	tvlv_handler->type = type;
 	tvlv_handler->version = version;
 	tvlv_handler->flags = flags;
 	kref_init(&tvlv_handler->refcount);
 	INIT_HLIST_NODE(&tvlv_handler->list);

 	kref_get(&tvlv_handler->refcount);
 	hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
 	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);

 	/* don't return reference to new tvlv_handler */
 	batadv_tvlv_handler_put(tvlv_handler);
 }

 /**
  * batadv_tvlv_handler_unregister() - unregister tvlv handler based on the
  *  provided type and version (both need to match)
  * @bat_priv: the bat priv with all the soft interface information
  * @type: tvlv handler type to be unregistered
  * @version: tvlv handler version to be unregistered
  */
 void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
 				    u8 type, u8 version)
 {
 	struct batadv_tvlv_handler *tvlv_handler;

 	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
 	if (!tvlv_handler)
 		return;

 	batadv_tvlv_handler_put(tvlv_handler);
 	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
 	hlist_del_rcu(&tvlv_handler->list);
 	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
 	batadv_tvlv_handler_put(tvlv_handler);
 }

 /**
  * batadv_tvlv_unicast_send() - send a unicast packet with tvlv payload to the
  *  specified host
  * @bat_priv: the bat priv with all the soft interface information
  * @src: source mac address of the unicast packet
  * @dst: destination mac address of the unicast packet
  * @type: tvlv type
  * @version: tvlv version
  * @tvlv_value: tvlv content
  * @tvlv_value_len: tvlv content length
  */
 void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, u8 *src,
 			      u8 *dst, u8 type, u8 version,
 			      void *tvlv_value, u16 tvlv_value_len)
 {
 	struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
 	struct batadv_tvlv_hdr *tvlv_hdr;
 	struct batadv_orig_node *orig_node;
 	struct sk_buff *skb;
 	unsigned char *tvlv_buff;
 	unsigned int tvlv_len;
 	ssize_t hdr_len = sizeof(*unicast_tvlv_packet);

 	orig_node = batadv_orig_hash_find(bat_priv, dst);
 	if (!orig_node)
 		return;

 	tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;

 	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
 	if (!skb)
 		goto out;

 	skb->priority = TC_PRIO_CONTROL;
 	skb_reserve(skb, ETH_HLEN);
 	tvlv_buff = skb_put(skb, sizeof(*unicast_tvlv_packet) + tvlv_len);
 	unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)tvlv_buff;
 	unicast_tvlv_packet->packet_type = BATADV_UNICAST_TVLV;
 	unicast_tvlv_packet->version = BATADV_COMPAT_VERSION;
 	unicast_tvlv_packet->ttl = BATADV_TTL;
 	unicast_tvlv_packet->reserved = 0;
 	unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
 	unicast_tvlv_packet->align = 0;
 	ether_addr_copy(unicast_tvlv_packet->src, src);
 	ether_addr_copy(unicast_tvlv_packet->dst, dst);

 	tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
 	tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
 	tvlv_hdr->version = version;
 	tvlv_hdr->type = type;
 	tvlv_hdr->len = htons(tvlv_value_len);
 	tvlv_buff += sizeof(*tvlv_hdr);
 	memcpy(tvlv_buff, tvlv_value, tvlv_value_len);

 	batadv_send_skb_to_orig(skb, orig_node, NULL);
 out:
 	batadv_orig_node_put(orig_node);
 }
	// SPDX-License-Identifier: GPL-2.0
	/* Copyright (C) 2007-2020 B.A.T.M.A.N. contributors:
	*
	* Marek Lindner, Simon Wunderlich
	*/

	#include "main.h"

	#include <linux/byteorder/generic.h>
	#include <linux/etherdevice.h>
	#include <linux/gfp.h>
	#include <linux/if_ether.h>
	#include <linux/kernel.h>
	#include <linux/kref.h>
	#include <linux/list.h>
	#include <linux/lockdep.h>
	#include <linux/netdevice.h>
	#include <linux/pkt_sched.h>
	#include <linux/rculist.h>
	#include <linux/rcupdate.h>
	#include <linux/skbuff.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>
	#include <linux/stddef.h>
	#include <linux/string.h>
	#include <linux/types.h>
	#include <uapi/linux/batadv_packet.h>

	#include "originator.h"
	#include "send.h"
	#include "tvlv.h"

	/**
	* batadv_tvlv_handler_release() - release tvlv handler from lists and queue for
	* free after rcu grace period
	* @ref: kref pointer of the tvlv
	*/
	static void batadv_tvlv_handler_release(struct kref *ref)
	{
	struct batadv_tvlv_handler *tvlv_handler;

	tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount);
	kfree_rcu(tvlv_handler, rcu);
	}

	/**
	* batadv_tvlv_handler_put() - decrement the tvlv container refcounter and
	* possibly release it
	* @tvlv_handler: the tvlv handler to free
	*/
	static void batadv_tvlv_handler_put(struct batadv_tvlv_handler *tvlv_handler)
	{
	kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release);
	}

	/**
	* batadv_tvlv_handler_get() - retrieve tvlv handler from the tvlv handler list
	* based on the provided type and version (both need to match)
	* @bat_priv: the bat priv with all the soft interface information
	* @type: tvlv handler type to look for
	* @version: tvlv handler version to look for
	*
	* Return: tvlv handler if found or NULL otherwise.
	*/
	static struct batadv_tvlv_handler *
	batadv_tvlv_handler_get(struct batadv_priv *bat_priv, u8 type, u8 version)
	{
	struct batadv_tvlv_handler tvlv_handler_tmp, tvlv_handler = NULL;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tvlv_handler_tmp,
	&bat_priv->tvlv.handler_list, list) {
	if (tvlv_handler_tmp->type != type)
	continue;

	if (tvlv_handler_tmp->version != version)
	continue;

	if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount))
	continue;

	tvlv_handler = tvlv_handler_tmp;
	break;
	}
	rcu_read_unlock();

	return tvlv_handler;
	}

	/**
	* batadv_tvlv_container_release() - release tvlv from lists and free
	* @ref: kref pointer of the tvlv
	*/
	static void batadv_tvlv_container_release(struct kref *ref)
	{
	struct batadv_tvlv_container *tvlv;

	tvlv = container_of(ref, struct batadv_tvlv_container, refcount);
	kfree(tvlv);
	}

	/**
	* batadv_tvlv_container_put() - decrement the tvlv container refcounter and
	* possibly release it
	* @tvlv: the tvlv container to free
	*/
	static void batadv_tvlv_container_put(struct batadv_tvlv_container *tvlv)
	{
	kref_put(&tvlv->refcount, batadv_tvlv_container_release);
	}

	/**
	* batadv_tvlv_container_get() - retrieve tvlv container from the tvlv container
	* list based on the provided type and version (both need to match)
	* @bat_priv: the bat priv with all the soft interface information
	* @type: tvlv container type to look for
	* @version: tvlv container version to look for
	*
	* Has to be called with the appropriate locks being acquired
	* (tvlv.container_list_lock).
	*
	* Return: tvlv container if found or NULL otherwise.
	*/
	static struct batadv_tvlv_container *
	batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version)
	{
	struct batadv_tvlv_container tvlv_tmp, tvlv = NULL;

	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

	hlist_for_each_entry(tvlv_tmp, &bat_priv->tvlv.container_list, list) {
	if (tvlv_tmp->tvlv_hdr.type != type)
	continue;

	if (tvlv_tmp->tvlv_hdr.version != version)
	continue;

	kref_get(&tvlv_tmp->refcount);
	tvlv = tvlv_tmp;
	break;
	}

	return tvlv;
	}

	/**
	* batadv_tvlv_container_list_size() - calculate the size of the tvlv container
	* list entries
	* @bat_priv: the bat priv with all the soft interface information
	*
	* Has to be called with the appropriate locks being acquired
	* (tvlv.container_list_lock).
	*
	* Return: size of all currently registered tvlv containers in bytes.
	*/
	static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
	{
	struct batadv_tvlv_container *tvlv;
	u16 tvlv_len = 0;

	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
	tvlv_len += sizeof(struct batadv_tvlv_hdr);
	tvlv_len += ntohs(tvlv->tvlv_hdr.len);
	}

	return tvlv_len;
	}

	/**
	* batadv_tvlv_container_remove() - remove tvlv container from the tvlv
	* container list
	* @bat_priv: the bat priv with all the soft interface information
	* @tvlv: the to be removed tvlv container
	*
	* Has to be called with the appropriate locks being acquired
	* (tvlv.container_list_lock).
	*/
	static void batadv_tvlv_container_remove(struct batadv_priv *bat_priv,
	struct batadv_tvlv_container *tvlv)
	{
	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);

	if (!tvlv)
	return;

	hlist_del(&tvlv->list);

	/* first call to decrement the counter, second call to free */
	batadv_tvlv_container_put(tvlv);
	batadv_tvlv_container_put(tvlv);
	}

	/**
	* batadv_tvlv_container_unregister() - unregister tvlv container based on the
	* provided type and version (both need to match)
	* @bat_priv: the bat priv with all the soft interface information
	* @type: tvlv container type to unregister
	* @version: tvlv container type to unregister
	*/
	void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
	u8 type, u8 version)
	{
	struct batadv_tvlv_container *tvlv;

	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
	tvlv = batadv_tvlv_container_get(bat_priv, type, version);
	batadv_tvlv_container_remove(bat_priv, tvlv);
	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
	}

	/**
	* batadv_tvlv_container_register() - register tvlv type, version and content
	* to be propagated with each (primary interface) OGM
	* @bat_priv: the bat priv with all the soft interface information
	* @type: tvlv container type
	* @version: tvlv container version
	* @tvlv_value: tvlv container content
	* @tvlv_value_len: tvlv container content length
	*
	* If a container of the same type and version was already registered the new
	* content is going to replace the old one.
	*/
	void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
	u8 type, u8 version,
	void *tvlv_value, u16 tvlv_value_len)
	{
	struct batadv_tvlv_container tvlv_old, tvlv_new;

	if (!tvlv_value)
	tvlv_value_len = 0;

	tvlv_new = kzalloc(sizeof(*tvlv_new) + tvlv_value_len, GFP_ATOMIC);
	if (!tvlv_new)
	return;

	tvlv_new->tvlv_hdr.version = version;
	tvlv_new->tvlv_hdr.type = type;
	tvlv_new->tvlv_hdr.len = htons(tvlv_value_len);

	memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len));
	INIT_HLIST_NODE(&tvlv_new->list);
	kref_init(&tvlv_new->refcount);

	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
	tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
	batadv_tvlv_container_remove(bat_priv, tvlv_old);

	kref_get(&tvlv_new->refcount);
	hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);

	/* don't return reference to new tvlv_container */
	batadv_tvlv_container_put(tvlv_new);
	}

	/**
	* batadv_tvlv_realloc_packet_buff() - reallocate packet buffer to accommodate
	* requested packet size
	* @packet_buff: packet buffer
	* @packet_buff_len: packet buffer size
	* @min_packet_len: requested packet minimum size
	* @additional_packet_len: requested additional packet size on top of minimum
	* size
	*
	* Return: true of the packet buffer could be changed to the requested size,
	* false otherwise.
	*/
	static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff,
	int *packet_buff_len,
	int min_packet_len,
	int additional_packet_len)
	{
	unsigned char *new_buff;

	new_buff = kmalloc(min_packet_len + additional_packet_len, GFP_ATOMIC);

	/* keep old buffer if kmalloc should fail */
	if (!new_buff)
	return false;

	memcpy(new_buff, *packet_buff, min_packet_len);
	kfree(*packet_buff);
	*packet_buff = new_buff;
	*packet_buff_len = min_packet_len + additional_packet_len;

	return true;
	}

	/**
	* batadv_tvlv_container_ogm_append() - append tvlv container content to given
	* OGM packet buffer
	* @bat_priv: the bat priv with all the soft interface information
	* @packet_buff: ogm packet buffer
	* @packet_buff_len: ogm packet buffer size including ogm header and tvlv
	* content
	* @packet_min_len: ogm header size to be preserved for the OGM itself
	*
	* The ogm packet might be enlarged or shrunk depending on the current size
	* and the size of the to-be-appended tvlv containers.
	*
	* Return: size of all appended tvlv containers in bytes.
	*/
	u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
	unsigned char **packet_buff,
	int *packet_buff_len, int packet_min_len)
	{
	struct batadv_tvlv_container *tvlv;
	struct batadv_tvlv_hdr *tvlv_hdr;
	u16 tvlv_value_len;
	void *tvlv_value;
	bool ret;

	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
	tvlv_value_len = batadv_tvlv_container_list_size(bat_priv);

	ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len,
	packet_min_len, tvlv_value_len);

	if (!ret)
	goto end;

	if (!tvlv_value_len)
	goto end;

	tvlv_value = (*packet_buff) + packet_min_len;

	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
	tvlv_hdr = tvlv_value;
	tvlv_hdr->type = tvlv->tvlv_hdr.type;
	tvlv_hdr->version = tvlv->tvlv_hdr.version;
	tvlv_hdr->len = tvlv->tvlv_hdr.len;
	tvlv_value = tvlv_hdr + 1;
	memcpy(tvlv_value, tvlv + 1, ntohs(tvlv->tvlv_hdr.len));
	tvlv_value = (u8 *)tvlv_value + ntohs(tvlv->tvlv_hdr.len);
	}

	end:
	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
	return tvlv_value_len;
	}

	/**
	* batadv_tvlv_call_handler() - parse the given tvlv buffer to call the
	* appropriate handlers
	* @bat_priv: the bat priv with all the soft interface information
	* @tvlv_handler: tvlv callback function handling the tvlv content
	* @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
	* @orig_node: orig node emitting the ogm packet
	* @src: source mac address of the unicast packet
	* @dst: destination mac address of the unicast packet
	* @tvlv_value: tvlv content
	* @tvlv_value_len: tvlv content length
	*
	* Return: success if handler was not found or the return value of the handler
	* callback.
	*/
	static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv,
	struct batadv_tvlv_handler *tvlv_handler,
	bool ogm_source,
	struct batadv_orig_node *orig_node,
	u8 src, u8 dst,
	void *tvlv_value, u16 tvlv_value_len)
	{
	if (!tvlv_handler)
	return NET_RX_SUCCESS;

	if (ogm_source) {
	if (!tvlv_handler->ogm_handler)
	return NET_RX_SUCCESS;

	if (!orig_node)
	return NET_RX_SUCCESS;

	tvlv_handler->ogm_handler(bat_priv, orig_node,
	BATADV_NO_FLAGS,
	tvlv_value, tvlv_value_len);
	tvlv_handler->flags \|= BATADV_TVLV_HANDLER_OGM_CALLED;
	} else {
	if (!src)
	return NET_RX_SUCCESS;

	if (!dst)
	return NET_RX_SUCCESS;

	if (!tvlv_handler->unicast_handler)
	return NET_RX_SUCCESS;

	return tvlv_handler->unicast_handler(bat_priv, src,
	dst, tvlv_value,
	tvlv_value_len);
	}

	return NET_RX_SUCCESS;
	}

	/**
	* batadv_tvlv_containers_process() - parse the given tvlv buffer to call the
	* appropriate handlers
	* @bat_priv: the bat priv with all the soft interface information
	* @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
	* @orig_node: orig node emitting the ogm packet
	* @src: source mac address of the unicast packet
	* @dst: destination mac address of the unicast packet
	* @tvlv_value: tvlv content
	* @tvlv_value_len: tvlv content length
	*
	* Return: success when processing an OGM or the return value of all called
	* handler callbacks.
	*/
	int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
	bool ogm_source,
	struct batadv_orig_node *orig_node,
	u8 src, u8 dst,
	void *tvlv_value, u16 tvlv_value_len)
	{
	struct batadv_tvlv_handler *tvlv_handler;
	struct batadv_tvlv_hdr *tvlv_hdr;
	u16 tvlv_value_cont_len;
	u8 cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
	int ret = NET_RX_SUCCESS;

	while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
	tvlv_hdr = tvlv_value;
	tvlv_value_cont_len = ntohs(tvlv_hdr->len);
	tvlv_value = tvlv_hdr + 1;
	tvlv_value_len -= sizeof(*tvlv_hdr);

	if (tvlv_value_cont_len > tvlv_value_len)
	break;

	tvlv_handler = batadv_tvlv_handler_get(bat_priv,
	tvlv_hdr->type,
	tvlv_hdr->version);

	ret \|= batadv_tvlv_call_handler(bat_priv, tvlv_handler,
	ogm_source, orig_node,
	src, dst, tvlv_value,
	tvlv_value_cont_len);
	if (tvlv_handler)
	batadv_tvlv_handler_put(tvlv_handler);
	tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len;
	tvlv_value_len -= tvlv_value_cont_len;
	}

	if (!ogm_source)
	return ret;

	rcu_read_lock();
	hlist_for_each_entry_rcu(tvlv_handler,
	&bat_priv->tvlv.handler_list, list) {
	if ((tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
	!(tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CALLED))
	tvlv_handler->ogm_handler(bat_priv, orig_node,
	cifnotfound, NULL, 0);

	tvlv_handler->flags &= ~BATADV_TVLV_HANDLER_OGM_CALLED;
	}
	rcu_read_unlock();

	return NET_RX_SUCCESS;
	}

	/**
	* batadv_tvlv_ogm_receive() - process an incoming ogm and call the appropriate
	* handlers
	* @bat_priv: the bat priv with all the soft interface information
	* @batadv_ogm_packet: ogm packet containing the tvlv containers
	* @orig_node: orig node emitting the ogm packet
	*/
	void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
	struct batadv_ogm_packet *batadv_ogm_packet,
	struct batadv_orig_node *orig_node)
	{
	void *tvlv_value;
	u16 tvlv_value_len;

	if (!batadv_ogm_packet)
	return;

	tvlv_value_len = ntohs(batadv_ogm_packet->tvlv_len);
	if (!tvlv_value_len)
	return;

	tvlv_value = batadv_ogm_packet + 1;

	batadv_tvlv_containers_process(bat_priv, true, orig_node, NULL, NULL,
	tvlv_value, tvlv_value_len);
	}

	/**
	* batadv_tvlv_handler_register() - register tvlv handler based on the provided
	* type and version (both need to match) for ogm tvlv payload and/or unicast
	* payload
	* @bat_priv: the bat priv with all the soft interface information
	* @optr: ogm tvlv handler callback function. This function receives the orig
	* node, flags and the tvlv content as argument to process.
	* @uptr: unicast tvlv handler callback function. This function receives the
	* source & destination of the unicast packet as well as the tvlv content
	* to process.
	* @type: tvlv handler type to be registered
	* @version: tvlv handler version to be registered
	* @flags: flags to enable or disable TVLV API behavior
	*/
	void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
	void (optr)(struct batadv_priv bat_priv,
	struct batadv_orig_node *orig,
	u8 flags,
	void *tvlv_value,
	u16 tvlv_value_len),
	int (uptr)(struct batadv_priv bat_priv,
	u8 src, u8 dst,
	void *tvlv_value,
	u16 tvlv_value_len),
	u8 type, u8 version, u8 flags)
	{
	struct batadv_tvlv_handler *tvlv_handler;

	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);

	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
	if (tvlv_handler) {
	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
	batadv_tvlv_handler_put(tvlv_handler);
	return;
	}

	tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
	if (!tvlv_handler) {
	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
	return;
	}

	tvlv_handler->ogm_handler = optr;
	tvlv_handler->unicast_handler = uptr;
	tvlv_handler->type = type;
	tvlv_handler->version = version;
	tvlv_handler->flags = flags;
	kref_init(&tvlv_handler->refcount);
	INIT_HLIST_NODE(&tvlv_handler->list);

	kref_get(&tvlv_handler->refcount);
	hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);

	/* don't return reference to new tvlv_handler */
	batadv_tvlv_handler_put(tvlv_handler);
	}

	/**
	* batadv_tvlv_handler_unregister() - unregister tvlv handler based on the
	* provided type and version (both need to match)
	* @bat_priv: the bat priv with all the soft interface information
	* @type: tvlv handler type to be unregistered
	* @version: tvlv handler version to be unregistered
	*/
	void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
	u8 type, u8 version)
	{
	struct batadv_tvlv_handler *tvlv_handler;

	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
	if (!tvlv_handler)
	return;

	batadv_tvlv_handler_put(tvlv_handler);
	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
	hlist_del_rcu(&tvlv_handler->list);
	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
	batadv_tvlv_handler_put(tvlv_handler);
	}

	/**
	* batadv_tvlv_unicast_send() - send a unicast packet with tvlv payload to the
	* specified host
	* @bat_priv: the bat priv with all the soft interface information
	* @src: source mac address of the unicast packet
	* @dst: destination mac address of the unicast packet
	* @type: tvlv type
	* @version: tvlv version
	* @tvlv_value: tvlv content
	* @tvlv_value_len: tvlv content length
	*/
	void batadv_tvlv_unicast_send(struct batadv_priv bat_priv, u8 src,
	u8 *dst, u8 type, u8 version,
	void *tvlv_value, u16 tvlv_value_len)
	{
	struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
	struct batadv_tvlv_hdr *tvlv_hdr;
	struct batadv_orig_node *orig_node;
	struct sk_buff *skb;
	unsigned char *tvlv_buff;
	unsigned int tvlv_len;
	ssize_t hdr_len = sizeof(*unicast_tvlv_packet);

	orig_node = batadv_orig_hash_find(bat_priv, dst);
	if (!orig_node)
	return;

	tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;

	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
	if (!skb)
	goto out;

	skb->priority = TC_PRIO_CONTROL;
	skb_reserve(skb, ETH_HLEN);
	tvlv_buff = skb_put(skb, sizeof(*unicast_tvlv_packet) + tvlv_len);
	unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)tvlv_buff;
	unicast_tvlv_packet->packet_type = BATADV_UNICAST_TVLV;
	unicast_tvlv_packet->version = BATADV_COMPAT_VERSION;
	unicast_tvlv_packet->ttl = BATADV_TTL;
	unicast_tvlv_packet->reserved = 0;
	unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
	unicast_tvlv_packet->align = 0;
	ether_addr_copy(unicast_tvlv_packet->src, src);
	ether_addr_copy(unicast_tvlv_packet->dst, dst);

	tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
	tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
	tvlv_hdr->version = version;
	tvlv_hdr->type = type;
	tvlv_hdr->len = htons(tvlv_value_len);
	tvlv_buff += sizeof(*tvlv_hdr);
	memcpy(tvlv_buff, tvlv_value, tvlv_value_len);

	batadv_send_skb_to_orig(skb, orig_node, NULL);
	out:
	batadv_orig_node_put(orig_node);
	}