diff options
Diffstat (limited to 'net/batman-adv/send.c')
| -rw-r--r-- | net/batman-adv/send.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c new file mode 100644 index 000000000..3d64ed20c --- /dev/null +++ b/net/batman-adv/send.c @@ -0,0 +1,645 @@ +/* Copyright (C) 2007-2014 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 "distributed-arp-table.h" +#include "send.h" +#include "routing.h" +#include "translation-table.h" +#include "soft-interface.h" +#include "hard-interface.h" +#include "gateway_common.h" +#include "gateway_client.h" +#include "originator.h" +#include "network-coding.h" +#include "fragmentation.h" +#include "multicast.h" + +static void batadv_send_outstanding_bcast_packet(struct work_struct *work); + +/* send out an already prepared packet to the given address via the + * specified batman interface + */ +int batadv_send_skb_packet(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface, + const uint8_t *dst_addr) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + struct ethhdr *ethhdr; + + if (hard_iface->if_status != BATADV_IF_ACTIVE) + goto send_skb_err; + + if (unlikely(!hard_iface->net_dev)) + goto send_skb_err; + + if (!(hard_iface->net_dev->flags & IFF_UP)) { + pr_warn("Interface %s is not up - can't send packet via that interface!\n", + hard_iface->net_dev->name); + goto send_skb_err; + } + + /* push to the ethernet header. */ + if (batadv_skb_head_push(skb, ETH_HLEN) < 0) + goto send_skb_err; + + skb_reset_mac_header(skb); + + ethhdr = eth_hdr(skb); + ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr); + ether_addr_copy(ethhdr->h_dest, dst_addr); + ethhdr->h_proto = htons(ETH_P_BATMAN); + + skb_set_network_header(skb, ETH_HLEN); + skb->protocol = htons(ETH_P_BATMAN); + + skb->dev = hard_iface->net_dev; + + /* Save a clone of the skb to use when decoding coded packets */ + batadv_nc_skb_store_for_decoding(bat_priv, skb); + + /* dev_queue_xmit() returns a negative result on error. However on + * congestion and traffic shaping, it drops and returns NET_XMIT_DROP + * (which is > 0). This will not be treated as an error. + */ + return dev_queue_xmit(skb); +send_skb_err: + kfree_skb(skb); + return NET_XMIT_DROP; +} + +/** + * batadv_send_skb_to_orig - Lookup next-hop and transmit skb. + * @skb: Packet to be transmitted. + * @orig_node: Final destination of the packet. + * @recv_if: Interface used when receiving the packet (can be NULL). + * + * Looks up the best next-hop towards the passed originator and passes the + * skb on for preparation of MAC header. If the packet originated from this + * host, NULL can be passed as recv_if and no interface alternating is + * attempted. + * + * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or + * NET_XMIT_POLICED if the skb is buffered for later transmit. + */ +int batadv_send_skb_to_orig(struct sk_buff *skb, + struct batadv_orig_node *orig_node, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = orig_node->bat_priv; + struct batadv_neigh_node *neigh_node; + int ret = NET_XMIT_DROP; + + /* batadv_find_router() increases neigh_nodes refcount if found. */ + neigh_node = batadv_find_router(bat_priv, orig_node, recv_if); + if (!neigh_node) + goto out; + + /* Check if the skb is too large to send in one piece and fragment + * it if needed. + */ + if (atomic_read(&bat_priv->fragmentation) && + skb->len > neigh_node->if_incoming->net_dev->mtu) { + /* Fragment and send packet. */ + if (batadv_frag_send_packet(skb, orig_node, neigh_node)) + ret = NET_XMIT_SUCCESS; + + goto out; + } + + /* try to network code the packet, if it is received on an interface + * (i.e. being forwarded). If the packet originates from this node or if + * network coding fails, then send the packet as usual. + */ + if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) { + ret = NET_XMIT_POLICED; + } else { + batadv_send_skb_packet(skb, neigh_node->if_incoming, + neigh_node->addr); + ret = NET_XMIT_SUCCESS; + } + +out: + if (neigh_node) + batadv_neigh_node_free_ref(neigh_node); + + return ret; +} + +/** + * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the + * common fields for unicast packets + * @skb: the skb carrying the unicast header to initialize + * @hdr_size: amount of bytes to push at the beginning of the skb + * @orig_node: the destination node + * + * Returns false if the buffer extension was not possible or true otherwise. + */ +static bool +batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size, + struct batadv_orig_node *orig_node) +{ + struct batadv_unicast_packet *unicast_packet; + uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); + + if (batadv_skb_head_push(skb, hdr_size) < 0) + return false; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + unicast_packet->version = BATADV_COMPAT_VERSION; + /* batman packet type: unicast */ + unicast_packet->packet_type = BATADV_UNICAST; + /* set unicast ttl */ + unicast_packet->ttl = BATADV_TTL; + /* copy the destination for faster routing */ + ether_addr_copy(unicast_packet->dest, orig_node->orig); + /* set the destination tt version number */ + unicast_packet->ttvn = ttvn; + + return true; +} + +/** + * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header + * @skb: the skb containing the payload to encapsulate + * @orig_node: the destination node + * + * Returns false if the payload could not be encapsulated or true otherwise. + */ +static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb, + struct batadv_orig_node *orig_node) +{ + size_t uni_size = sizeof(struct batadv_unicast_packet); + + return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node); +} + +/** + * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a + * unicast 4addr header + * @bat_priv: the bat priv with all the soft interface information + * @skb: the skb containing the payload to encapsulate + * @orig_node: the destination node + * @packet_subtype: the unicast 4addr packet subtype to use + * + * Returns false if the payload could not be encapsulated or true otherwise. + */ +bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv, + struct sk_buff *skb, + struct batadv_orig_node *orig, + int packet_subtype) +{ + struct batadv_hard_iface *primary_if; + struct batadv_unicast_4addr_packet *uc_4addr_packet; + bool ret = false; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* Pull the header space and fill the unicast_packet substructure. + * We can do that because the first member of the uc_4addr_packet + * is of type struct unicast_packet + */ + if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet), + orig)) + goto out; + + uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; + uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR; + ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr); + uc_4addr_packet->subtype = packet_subtype; + uc_4addr_packet->reserved = 0; + + ret = true; +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + return ret; +} + +/** + * batadv_send_skb_unicast - encapsulate and send an skb via unicast + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @packet_type: the batman unicast packet type to use + * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast + * 4addr packets) + * @orig_node: the originator to send the packet to + * @vid: the vid to be used to search the translation table + * + * Wrap the given skb into a batman-adv unicast or unicast-4addr header + * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied + * as packet_type. Then send this frame to the given orig_node and release a + * reference to this orig_node. + * + * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_unicast(struct batadv_priv *bat_priv, + struct sk_buff *skb, int packet_type, + int packet_subtype, + struct batadv_orig_node *orig_node, + unsigned short vid) +{ + struct ethhdr *ethhdr; + struct batadv_unicast_packet *unicast_packet; + int ret = NET_XMIT_DROP; + + if (!orig_node) + goto out; + + switch (packet_type) { + case BATADV_UNICAST: + if (!batadv_send_skb_prepare_unicast(skb, orig_node)) + goto out; + break; + case BATADV_UNICAST_4ADDR: + if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb, + orig_node, + packet_subtype)) + goto out; + break; + default: + /* this function supports UNICAST and UNICAST_4ADDR only. It + * should never be invoked with any other packet type + */ + goto out; + } + + /* skb->data might have been reallocated by + * batadv_send_skb_prepare_unicast{,_4addr}() + */ + ethhdr = eth_hdr(skb); + unicast_packet = (struct batadv_unicast_packet *)skb->data; + + /* inform the destination node that we are still missing a correct route + * for this client. The destination will receive this packet and will + * try to reroute it because the ttvn contained in the header is less + * than the current one + */ + if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) + unicast_packet->ttvn = unicast_packet->ttvn - 1; + + if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP) + ret = NET_XMIT_SUCCESS; + +out: + if (orig_node) + batadv_orig_node_free_ref(orig_node); + if (ret == NET_XMIT_DROP) + kfree_skb(skb); + return ret; +} + +/** + * batadv_send_skb_via_tt_generic - send an skb via TT lookup + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @packet_type: the batman unicast packet type to use + * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast + * 4addr packets) + * @dst_hint: can be used to override the destination contained in the skb + * @vid: the vid to be used to search the translation table + * + * Look up the recipient node for the destination address in the ethernet + * header via the translation table. Wrap the given skb into a batman-adv + * unicast or unicast-4addr header depending on whether BATADV_UNICAST or + * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame + * to the according destination node. + * + * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, + struct sk_buff *skb, int packet_type, + int packet_subtype, uint8_t *dst_hint, + unsigned short vid) +{ + struct ethhdr *ethhdr = (struct ethhdr *)skb->data; + struct batadv_orig_node *orig_node; + uint8_t *src, *dst; + + src = ethhdr->h_source; + dst = ethhdr->h_dest; + + /* if we got an hint! let's send the packet to this client (if any) */ + if (dst_hint) { + src = NULL; + dst = dst_hint; + } + orig_node = batadv_transtable_search(bat_priv, src, dst, vid); + + return batadv_send_skb_unicast(bat_priv, skb, packet_type, + packet_subtype, orig_node, vid); +} + +/** + * batadv_send_skb_via_gw - send an skb via gateway lookup + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @vid: the vid to be used to search the translation table + * + * Look up the currently selected gateway. Wrap the given skb into a batman-adv + * unicast header and send this frame to this gateway node. + * + * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ + struct batadv_orig_node *orig_node; + + orig_node = batadv_gw_get_selected_orig(bat_priv); + return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0, + orig_node, vid); +} + +void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + + if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) || + (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)) + return; + + /* the interface gets activated here to avoid race conditions between + * the moment of activating the interface in + * hardif_activate_interface() where the originator mac is set and + * outdated packets (especially uninitialized mac addresses) in the + * packet queue + */ + if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED) + hard_iface->if_status = BATADV_IF_ACTIVE; + + bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface); +} + +static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) +{ + if (forw_packet->skb) + kfree_skb(forw_packet->skb); + if (forw_packet->if_incoming) + batadv_hardif_free_ref(forw_packet->if_incoming); + if (forw_packet->if_outgoing) + batadv_hardif_free_ref(forw_packet->if_outgoing); + kfree(forw_packet); +} + +static void +_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time) +{ + /* add new packet to packet list */ + spin_lock_bh(&bat_priv->forw_bcast_list_lock); + hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list); + spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + + /* start timer for this packet */ + queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work, + send_time); +} + +/* add a broadcast packet to the queue and setup timers. broadcast packets + * are sent multiple times to increase probability for being received. + * + * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on + * errors. + * + * The skb is not consumed, so the caller should make sure that the + * skb is freed. + */ +int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, + const struct sk_buff *skb, + unsigned long delay) +{ + struct batadv_hard_iface *primary_if = NULL; + struct batadv_forw_packet *forw_packet; + struct batadv_bcast_packet *bcast_packet; + struct sk_buff *newskb; + + if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "bcast packet queue full\n"); + goto out; + } + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out_and_inc; + + forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); + + if (!forw_packet) + goto out_and_inc; + + newskb = skb_copy(skb, GFP_ATOMIC); + if (!newskb) + goto packet_free; + + /* as we have a copy now, it is safe to decrease the TTL */ + bcast_packet = (struct batadv_bcast_packet *)newskb->data; + bcast_packet->ttl--; + + skb_reset_mac_header(newskb); + + forw_packet->skb = newskb; + forw_packet->if_incoming = primary_if; + forw_packet->if_outgoing = NULL; + + /* how often did we send the bcast packet ? */ + forw_packet->num_packets = 0; + + INIT_DELAYED_WORK(&forw_packet->delayed_work, + batadv_send_outstanding_bcast_packet); + + _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay); + return NETDEV_TX_OK; + +packet_free: + kfree(forw_packet); +out_and_inc: + atomic_inc(&bat_priv->bcast_queue_left); +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + return NETDEV_TX_BUSY; +} + +static void batadv_send_outstanding_bcast_packet(struct work_struct *work) +{ + struct batadv_hard_iface *hard_iface; + struct delayed_work *delayed_work; + struct batadv_forw_packet *forw_packet; + struct sk_buff *skb1; + struct net_device *soft_iface; + struct batadv_priv *bat_priv; + + delayed_work = container_of(work, struct delayed_work, work); + forw_packet = container_of(delayed_work, struct batadv_forw_packet, + delayed_work); + soft_iface = forw_packet->if_incoming->soft_iface; + bat_priv = netdev_priv(soft_iface); + + spin_lock_bh(&bat_priv->forw_bcast_list_lock); + hlist_del(&forw_packet->list); + spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) + goto out; + + if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) + goto out; + + /* rebroadcast packet */ + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->soft_iface != soft_iface) + continue; + + if (forw_packet->num_packets >= hard_iface->num_bcasts) + continue; + + /* send a copy of the saved skb */ + skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC); + if (skb1) + batadv_send_skb_packet(skb1, hard_iface, + batadv_broadcast_addr); + } + rcu_read_unlock(); + + forw_packet->num_packets++; + + /* if we still have some more bcasts to send */ + if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) { + _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, + msecs_to_jiffies(5)); + return; + } + +out: + batadv_forw_packet_free(forw_packet); + atomic_inc(&bat_priv->bcast_queue_left); +} + +void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work) +{ + struct delayed_work *delayed_work; + struct batadv_forw_packet *forw_packet; + struct batadv_priv *bat_priv; + + delayed_work = container_of(work, struct delayed_work, work); + forw_packet = container_of(delayed_work, struct batadv_forw_packet, + delayed_work); + bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface); + spin_lock_bh(&bat_priv->forw_bat_list_lock); + hlist_del(&forw_packet->list); + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) + goto out; + + bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet); + + /* we have to have at least one packet in the queue to determine the + * queues wake up time unless we are shutting down. + * + * only re-schedule if this is the "original" copy, e.g. the OGM of the + * primary interface should only be rescheduled once per period, but + * this function will be called for the forw_packet instances of the + * other secondary interfaces as well. + */ + if (forw_packet->own && + forw_packet->if_incoming == forw_packet->if_outgoing) + batadv_schedule_bat_ogm(forw_packet->if_incoming); + +out: + /* don't count own packet */ + if (!forw_packet->own) + atomic_inc(&bat_priv->batman_queue_left); + + batadv_forw_packet_free(forw_packet); +} + +void +batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, + const struct batadv_hard_iface *hard_iface) +{ + struct batadv_forw_packet *forw_packet; + struct hlist_node *safe_tmp_node; + bool pending; + + if (hard_iface) + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "purge_outstanding_packets(): %s\n", + hard_iface->net_dev->name); + else + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "purge_outstanding_packets()\n"); + + /* free bcast list */ + spin_lock_bh(&bat_priv->forw_bcast_list_lock); + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, + &bat_priv->forw_bcast_list, list) { + /* if purge_outstanding_packets() was called with an argument + * we delete only packets belonging to the given interface + */ + if ((hard_iface) && + (forw_packet->if_incoming != hard_iface)) + continue; + + spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + + /* batadv_send_outstanding_bcast_packet() will lock the list to + * delete the item from the list + */ + pending = cancel_delayed_work_sync(&forw_packet->delayed_work); + spin_lock_bh(&bat_priv->forw_bcast_list_lock); + + if (pending) { + hlist_del(&forw_packet->list); + batadv_forw_packet_free(forw_packet); + } + } + spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + + /* free batman packet list */ + spin_lock_bh(&bat_priv->forw_bat_list_lock); + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, + &bat_priv->forw_bat_list, list) { + /* if purge_outstanding_packets() was called with an argument + * we delete only packets belonging to the given interface + */ + if ((hard_iface) && + (forw_packet->if_incoming != hard_iface) && + (forw_packet->if_outgoing != hard_iface)) + continue; + + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + /* send_outstanding_bat_packet() will lock the list to + * delete the item from the list + */ + pending = cancel_delayed_work_sync(&forw_packet->delayed_work); + spin_lock_bh(&bat_priv->forw_bat_list_lock); + + if (pending) { + hlist_del(&forw_packet->list); + batadv_forw_packet_free(forw_packet); + } + } + spin_unlock_bh(&bat_priv->forw_bat_list_lock); +} |