/* Copyright (C) 2007-2016 B.A.T.M.A.N. contributors: * * Marek Lindner, Simon Wunderlich * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "main.h" #include <linux/byteorder/generic.h> #include <linux/etherdevice.h> #include <linux/fs.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 "originator.h" #include "packet.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; tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version); if (tvlv_handler) { batadv_tvlv_handler_put(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; kref_init(&tvlv_handler->refcount); INIT_HLIST_NODE(&tvlv_handler->list); spin_lock_bh(&bat_priv->tvlv.handler_list_lock); 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); }