/* 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 . */ #include "send.h" #include "main.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "distributed-arp-table.h" #include "fragmentation.h" #include "gateway_client.h" #include "hard-interface.h" #include "log.h" #include "network-coding.h" #include "originator.h" #include "routing.h" #include "soft-interface.h" #include "translation-table.h" static void batadv_send_outstanding_bcast_packet(struct work_struct *work); /** * batadv_send_skb_packet - send an already prepared packet * @skb: the packet to send * @hard_iface: the interface to use to send the broadcast packet * @dst_addr: the payload destination * * Send out an already prepared packet to the given neighbor or broadcast it * using the specified interface. Either hard_iface or neigh_node must be not * NULL. * If neigh_node is NULL, then the packet is broadcasted using hard_iface, * otherwise it is sent as unicast to the given neighbor. * * Return: NET_TX_DROP in case of error or the result of dev_queue_xmit(skb) * otherwise */ int batadv_send_skb_packet(struct sk_buff *skb, struct batadv_hard_iface *hard_iface, const u8 *dst_addr) { struct batadv_priv *bat_priv; struct ethhdr *ethhdr; int ret; bat_priv = netdev_priv(hard_iface->soft_iface); 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. * * a negative value cannot be returned because it could be interepreted * as not consumed skb by callers of batadv_send_skb_to_orig. */ ret = dev_queue_xmit(skb); if (ret < 0) ret = NET_XMIT_DROP; return ret; send_skb_err: kfree_skb(skb); return NET_XMIT_DROP; } int batadv_send_broadcast_skb(struct sk_buff *skb, struct batadv_hard_iface *hard_iface) { return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr); } int batadv_send_unicast_skb(struct sk_buff *skb, struct batadv_neigh_node *neigh) { #ifdef CONFIG_BATMAN_ADV_BATMAN_V struct batadv_hardif_neigh_node *hardif_neigh; #endif int ret; ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr); #ifdef CONFIG_BATMAN_ADV_BATMAN_V hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr); if ((hardif_neigh) && (ret != NET_XMIT_DROP)) hardif_neigh->bat_v.last_unicast_tx = jiffies; if (hardif_neigh) batadv_hardif_neigh_put(hardif_neigh); #endif return ret; } /** * 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. * * Return: -1 on failure (and the skb is not consumed), -EINPROGRESS if the * skb is buffered for later transmit or the NET_XMIT status returned by the * lower routine if the packet has been passed down. * * If the returning value is not -1 the skb has been consumed. */ 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 = -1; /* 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. */ ret = batadv_frag_send_packet(skb, orig_node, neigh_node); 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 = -EINPROGRESS; else ret = batadv_send_unicast_skb(skb, neigh_node); out: if (neigh_node) batadv_neigh_node_put(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 * * Return: 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; u8 ttvn = (u8)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 * * Return: 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: the destination node * @packet_subtype: the unicast 4addr packet subtype to use * * Return: 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_put(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. * * Return: 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 batadv_unicast_packet *unicast_packet; struct ethhdr *ethhdr; int res, 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; res = batadv_send_skb_to_orig(skb, orig_node, NULL); if (res != -1) ret = NET_XMIT_SUCCESS; out: 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. * * Return: 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, u8 *dst_hint, unsigned short vid) { struct ethhdr *ethhdr = (struct ethhdr *)skb->data; struct batadv_orig_node *orig_node; u8 *src, *dst; int ret; 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); ret = batadv_send_skb_unicast(bat_priv, skb, packet_type, packet_subtype, orig_node, vid); if (orig_node) batadv_orig_node_put(orig_node); return ret; } /** * 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. * * Return: 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; int ret; orig_node = batadv_gw_get_selected_orig(bat_priv); ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR, BATADV_P_DATA, orig_node, vid); if (orig_node) batadv_orig_node_put(orig_node); return ret; } /** * batadv_forw_packet_free - free a forwarding packet * @forw_packet: The packet to free * * This frees a forwarding packet and releases any resources it might * have claimed. */ void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) { kfree_skb(forw_packet->skb); if (forw_packet->if_incoming) batadv_hardif_put(forw_packet->if_incoming); if (forw_packet->if_outgoing) batadv_hardif_put(forw_packet->if_outgoing); if (forw_packet->queue_left) atomic_inc(forw_packet->queue_left); kfree(forw_packet); } /** * batadv_forw_packet_alloc - allocate a forwarding packet * @if_incoming: The (optional) if_incoming to be grabbed * @if_outgoing: The (optional) if_outgoing to be grabbed * @queue_left: The (optional) queue counter to decrease * @bat_priv: The bat_priv for the mesh of this forw_packet * * Allocates a forwarding packet and tries to get a reference to the * (optional) if_incoming, if_outgoing and queue_left. If queue_left * is NULL then bat_priv is optional, too. * * Return: An allocated forwarding packet on success, NULL otherwise. */ struct batadv_forw_packet * batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, struct batadv_hard_iface *if_outgoing, atomic_t *queue_left, struct batadv_priv *bat_priv) { struct batadv_forw_packet *forw_packet; const char *qname; if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) { qname = "unknown"; if (queue_left == &bat_priv->bcast_queue_left) qname = "bcast"; if (queue_left == &bat_priv->batman_queue_left) qname = "batman"; batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "%s queue is full\n", qname); return NULL; } forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); if (!forw_packet) goto err; if (if_incoming) kref_get(&if_incoming->refcount); if (if_outgoing) kref_get(&if_outgoing->refcount); forw_packet->skb = NULL; forw_packet->queue_left = queue_left; forw_packet->if_incoming = if_incoming; forw_packet->if_outgoing = if_outgoing; forw_packet->num_packets = 0; return forw_packet; err: if (queue_left) atomic_inc(queue_left); return NULL; } 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); } /** * batadv_add_bcast_packet_to_list - queue broadcast packet for multiple sends * @bat_priv: the bat priv with all the soft interface information * @skb: broadcast packet to add * @delay: number of jiffies to wait before sending * * add a broadcast packet to the queue and setup timers. broadcast packets * are sent multiple times to increase probability for being received. * * The skb is not consumed, so the caller should make sure that the * skb is freed. * * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors. */ 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; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto err; forw_packet = batadv_forw_packet_alloc(primary_if, NULL, &bat_priv->bcast_queue_left, bat_priv); batadv_hardif_put(primary_if); if (!forw_packet) goto err; newskb = skb_copy(skb, GFP_ATOMIC); if (!newskb) goto err_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; 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; err_packet_free: batadv_forw_packet_free(forw_packet); err: 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 = to_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; if (!kref_get_unless_zero(&hard_iface->refcount)) continue; /* send a copy of the saved skb */ skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC); if (skb1) batadv_send_broadcast_skb(skb1, hard_iface); batadv_hardif_put(hard_iface); } 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); } 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) && (forw_packet->if_outgoing != 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); }