// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*/
#include "main.h"
#include <linux/byteorder/generic.h>
#include <linux/container_of.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_ether.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)
{
if (!tvlv_handler)
return;
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)
{
if (!tvlv)
return;
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
* @packet_type: indicates for which packet type the TVLV handler is called
* @orig_node: orig node emitting the ogm packet
* @skb: the skb the TVLV handler is called for
* @tvlv_value: tvlv content
* @tvlv_value_len: tvlv content length
*
* Return: success if the 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,
u8 packet_type,
struct batadv_orig_node *orig_node,
struct sk_buff *skb, void *tvlv_value,
u16 tvlv_value_len)
{
unsigned int tvlv_offset;
u8 *src, *dst;
if (!tvlv_handler)
return NET_RX_SUCCESS;
switch (packet_type) {
case BATADV_IV_OGM:
case BATADV_OGM2:
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;
break;
case BATADV_UNICAST_TVLV:
if (!skb)
return NET_RX_SUCCESS;
if (!tvlv_handler->unicast_handler)
return NET_RX_SUCCESS;
src = ((struct batadv_unicast_tvlv_packet *)skb->data)->src;
dst = ((struct batadv_unicast_tvlv_packet *)skb->data)->dst;
return tvlv_handler->unicast_handler(bat_priv, src,
dst, tvlv_value,
tvlv_value_len);
case BATADV_MCAST:
if (!skb)
return NET_RX_SUCCESS;
if (!tvlv_handler->mcast_handler)
return NET_RX_SUCCESS;
tvlv_offset = (unsigned char *)tvlv_value - skb->data;
skb_set_network_header(skb, tvlv_offset);
skb_set_transport_header(skb, tvlv_offset + tvlv_value_len);
return tvlv_handler->mcast_handler(bat_priv, skb);
}
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
* @packet_type: indicates for which packet type the TVLV handler is called
* @orig_node: orig node emitting the ogm packet
* @skb: the skb the TVLV handler is called for
* @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,
u8 packet_type,
struct batadv_orig_node *orig_node,
struct sk_buff *skb, 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,
packet_type, orig_node, skb,
tvlv_value,
tvlv_value_cont_len);
batadv_tvlv_handler_put(tvlv_handler);
tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len;
tvlv_value_len -= tvlv_value_cont_len;
}
if (packet_type != BATADV_IV_OGM &&
packet_type != BATADV_OGM2)
return ret;
rcu_read_lock();
hlist_for_each_entry_rcu(tvlv_handler,
&bat_priv->tvlv.handler_list, list) {
if (!tvlv_handler->ogm_handler)
continue;
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, BATADV_IV_OGM, orig_node, 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.
* @mptr: multicast packet tvlv handler callback function. This function
* receives the full skb to process, with the skb network header pointing
* to the current tvlv and the skb transport header pointing to the first
* byte after the current tvlv.
* @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),
int (*mptr)(struct batadv_priv *bat_priv,
struct sk_buff *skb),
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->mcast_handler = mptr;
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, const u8 *src,
const 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);
}
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