batman-adv: tvlv - basic infrastructure

The goal is to provide the infrastructure for sending, receiving and
parsing information 'containers' while preserving backward
compatibility. TVLV (based on the commonly known Type Length Value
technique) was chosen as the format for those containers. Even if a
node does not know the tvlv type of a certain container it can simply
skip the current container and proceed with the next. Past experience
has shown features evolve over time, so a 'version' field was added
right from the start to allow differentiating between feature
variants - hence the name: T(ype) V(ersion) L(ength) V(alue).

This patch introduces the basic TVLV infrastructure:
 * register / unregister tvlv containers to be sent with each OGM
   (on primary interfaces only)
 * register / unregister callback handlers to be called upon
   finding the corresponding tvlv type in a tvlv buffer
 * unicast tvlv send / receive API calls

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

1 files changed, 575 insertions, 0 deletions

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 1356af660b5b..e2de68a5b0c6 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -36,6 +36,7 @@
 #include "gateway_client.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
+#include "unicast.h"
 #include "vis.h"
 #include "hash.h"
 #include "bat_algo.h"
@@ -112,6 +113,8 @@ int batadv_mesh_init(struct net_device *soft_iface)
         spin_lock_init(&bat_priv->gw.list_lock);
         spin_lock_init(&bat_priv->vis.hash_lock);
         spin_lock_init(&bat_priv->vis.list_lock);
+        spin_lock_init(&bat_priv->tvlv.container_list_lock);
+        spin_lock_init(&bat_priv->tvlv.handler_list_lock);
 
         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
@@ -119,6 +122,8 @@ int batadv_mesh_init(struct net_device *soft_iface)
         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
         INIT_LIST_HEAD(&bat_priv->tt.req_list);
         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
+        INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
+        INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
 
         ret = batadv_originator_init(bat_priv);
         if (ret < 0)
@@ -408,6 +413,8 @@ static void batadv_recv_handler_init(void)
         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
         /* Roaming advertisement */
         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
+        /* unicast tvlv packet */
+        batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
 }
 
 int
@@ -536,6 +543,574 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
         return htonl(crc);
 }
 
+/**
+ * batadv_tvlv_handler_free_ref - decrement the tvlv handler refcounter and
+ *  possibly free it
+ * @tvlv_handler: the tvlv handler to free
+ */
+static void
+batadv_tvlv_handler_free_ref(struct batadv_tvlv_handler *tvlv_handler)
+{
+        if (atomic_dec_and_test(&tvlv_handler->refcount))
+                kfree_rcu(tvlv_handler, rcu);
+}
+
+/**
+ * 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
+ *
+ * Returns tvlv handler if found or NULL otherwise.
+ */
+static struct batadv_tvlv_handler
+*batadv_tvlv_handler_get(struct batadv_priv *bat_priv,
+                         uint8_t type, uint8_t 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 (!atomic_inc_not_zero(&tvlv_handler_tmp->refcount))
+                        continue;
+
+                tvlv_handler = tvlv_handler_tmp;
+                break;
+        }
+        rcu_read_unlock();
+
+        return tvlv_handler;
+}
+
+/**
+ * batadv_tvlv_container_free_ref - decrement the tvlv container refcounter and
+ *  possibly free it
+ * @tvlv_handler: the tvlv container to free
+ */
+static void batadv_tvlv_container_free_ref(struct batadv_tvlv_container *tvlv)
+{
+        if (atomic_dec_and_test(&tvlv->refcount))
+                kfree(tvlv);
+}
+
+/**
+ * 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).
+ *
+ * Returns tvlv container if found or NULL otherwise.
+ */
+static struct batadv_tvlv_container
+*batadv_tvlv_container_get(struct batadv_priv *bat_priv,
+                           uint8_t type, uint8_t version)
+{
+        struct batadv_tvlv_container *tvlv_tmp, *tvlv = NULL;
+
+        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;
+
+                if (!atomic_inc_not_zero(&tvlv_tmp->refcount))
+                        continue;
+
+                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).
+ *
+ * Returns size of all currently registered tvlv containers in bytes.
+ */
+static uint16_t batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
+{
+        struct batadv_tvlv_container *tvlv;
+        uint16_t tvlv_len = 0;
+
+        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
+ * @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_tvlv_container *tvlv)
+{
+        if (!tvlv)
+                return;
+
+        hlist_del(&tvlv->list);
+
+        /* first call to decrement the counter, second call to free */
+        batadv_tvlv_container_free_ref(tvlv);
+        batadv_tvlv_container_free_ref(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,
+                                      uint8_t type, uint8_t 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(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,
+                                    uint8_t type, uint8_t version,
+                                    void *tvlv_value, uint16_t 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);
+        atomic_set(&tvlv_new->refcount, 1);
+
+        spin_lock_bh(&bat_priv->tvlv.container_list_lock);
+        tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
+        batadv_tvlv_container_remove(tvlv_old);
+        hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
+        spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
+}
+
+/**
+ * batadv_tvlv_realloc_packet_buff - reallocate packet buffer to accomodate
+ *  requested packet size
+ * @packet_buff: packet buffer
+ * @packet_buff_len: packet buffer size
+ * @packet_min_len: requested packet minimum size
+ * @additional_packet_len: requested additional packet size on top of minimum
+ *  size
+ *
+ * Returns 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) {
+                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;
+        }
+
+        return false;
+}
+
+/**
+ * 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.
+ *
+ * Returns size of all appended tvlv containers in bytes.
+ */
+uint16_t 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;
+        uint16_t 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 = (uint8_t *)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 wether 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
+ *
+ * Returns 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,
+                                    uint8_t *src, uint8_t *dst,
+                                    void *tvlv_value, uint16_t 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 wether 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
+ *
+ * Returns 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,
+                                   uint8_t *src, uint8_t *dst,
+                                   void *tvlv_value, uint16_t tvlv_value_len)
+{
+        struct batadv_tvlv_handler *tvlv_handler;
+        struct batadv_tvlv_hdr *tvlv_hdr;
+        uint16_t tvlv_value_cont_len;
+        uint8_t 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_free_ref(tvlv_handler);
+                tvlv_value = (uint8_t *)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;
+        uint16_t 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,
+                                               uint8_t flags,
+                                               void *tvlv_value,
+                                               uint16_t tvlv_value_len),
+                                  int (*uptr)(struct batadv_priv *bat_priv,
+                                              uint8_t *src, uint8_t *dst,
+                                              void *tvlv_value,
+                                              uint16_t tvlv_value_len),
+                                  uint8_t type, uint8_t version, uint8_t flags)
+{
+        struct batadv_tvlv_handler *tvlv_handler;
+
+        tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
+        if (tvlv_handler) {
+                batadv_tvlv_handler_free_ref(tvlv_handler);
+                return;
+        }
+
+        tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
+        if (!tvlv_handler)
+                return;
+
+        tvlv_handler->ogm_handler = optr;
+        tvlv_handler->unicast_handler = uptr;
+        tvlv_handler->type = type;
+        tvlv_handler->version = version;
+        tvlv_handler->flags = flags;
+        atomic_set(&tvlv_handler->refcount, 1);
+        INIT_HLIST_NODE(&tvlv_handler->list);
+
+        spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
+        hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
+        spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
+}
+
+/**
+ * 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,
+                                    uint8_t type, uint8_t version)
+{
+        struct batadv_tvlv_handler *tvlv_handler;
+
+        tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
+        if (!tvlv_handler)
+                return;
+
+        batadv_tvlv_handler_free_ref(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_free_ref(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, uint8_t *src,
+                              uint8_t *dst, uint8_t type, uint8_t version,
+                              void *tvlv_value, uint16_t 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 = NULL;
+        unsigned char *tvlv_buff;
+        unsigned int tvlv_len;
+        ssize_t hdr_len = sizeof(*unicast_tvlv_packet);
+        bool ret = false;
+
+        orig_node = batadv_orig_hash_find(bat_priv, dst);
+        if (!orig_node)
+                goto out;
+
+        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->header.packet_type = BATADV_UNICAST_TVLV;
+        unicast_tvlv_packet->header.version = BATADV_COMPAT_VERSION;
+        unicast_tvlv_packet->header.ttl = BATADV_TTL;
+        unicast_tvlv_packet->reserved = 0;
+        unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
+        unicast_tvlv_packet->align = 0;
+        memcpy(unicast_tvlv_packet->src, src, ETH_ALEN);
+        memcpy(unicast_tvlv_packet->dst, dst, ETH_ALEN);
+
+        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);
+
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
+                ret = true;
+
+out:
+        if (skb && !ret)
+                kfree_skb(skb);
+        if (orig_node)
+                batadv_orig_node_free_ref(orig_node);
+}
+
 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 {
         struct batadv_algo_ops *bat_algo_ops;