diff options
Diffstat (limited to 'net/batman-adv/tvlv.c')
| -rw-r--r-- | net/batman-adv/tvlv.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c new file mode 100644 index 000000000..99fc48efd --- /dev/null +++ b/net/batman-adv/tvlv.c @@ -0,0 +1,637 @@ +// 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) +{ + 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 + * @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 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, + 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); +} |