diff options
Diffstat (limited to 'net/batman-adv/routing.c')
| -rw-r--r-- | net/batman-adv/routing.c | 1300 |
1 files changed, 1300 insertions, 0 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c new file mode 100644 index 00000000..b27a4d79 --- /dev/null +++ b/net/batman-adv/routing.c @@ -0,0 +1,1300 @@ +/* Copyright (C) 2007-2013 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + */ + +#include "main.h" +#include "routing.h" +#include "send.h" +#include "soft-interface.h" +#include "hard-interface.h" +#include "icmp_socket.h" +#include "translation-table.h" +#include "originator.h" +#include "vis.h" +#include "unicast.h" +#include "bridge_loop_avoidance.h" +#include "distributed-arp-table.h" +#include "network-coding.h" + +static int batadv_route_unicast_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if); + +void batadv_slide_own_bcast_window(struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + struct batadv_hashtable *hash = bat_priv->orig_hash; + struct hlist_head *head; + struct batadv_orig_node *orig_node; + unsigned long *word; + uint32_t i; + size_t word_index; + uint8_t *w; + + for (i = 0; i < hash->size; i++) { + head = &hash->table[i]; + + rcu_read_lock(); + hlist_for_each_entry_rcu(orig_node, head, hash_entry) { + spin_lock_bh(&orig_node->ogm_cnt_lock); + word_index = hard_iface->if_num * BATADV_NUM_WORDS; + word = &(orig_node->bcast_own[word_index]); + + batadv_bit_get_packet(bat_priv, word, 1, 0); + w = &orig_node->bcast_own_sum[hard_iface->if_num]; + *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE); + spin_unlock_bh(&orig_node->ogm_cnt_lock); + } + rcu_read_unlock(); + } +} + +static void _batadv_update_route(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node) +{ + struct batadv_neigh_node *curr_router; + + curr_router = batadv_orig_node_get_router(orig_node); + + /* route deleted */ + if ((curr_router) && (!neigh_node)) { + batadv_dbg(BATADV_DBG_ROUTES, bat_priv, + "Deleting route towards: %pM\n", orig_node->orig); + batadv_tt_global_del_orig(bat_priv, orig_node, + "Deleted route towards originator"); + + /* route added */ + } else if ((!curr_router) && (neigh_node)) { + batadv_dbg(BATADV_DBG_ROUTES, bat_priv, + "Adding route towards: %pM (via %pM)\n", + orig_node->orig, neigh_node->addr); + /* route changed */ + } else if (neigh_node && curr_router) { + batadv_dbg(BATADV_DBG_ROUTES, bat_priv, + "Changing route towards: %pM (now via %pM - was via %pM)\n", + orig_node->orig, neigh_node->addr, + curr_router->addr); + } + + if (curr_router) + batadv_neigh_node_free_ref(curr_router); + + /* increase refcount of new best neighbor */ + if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount)) + neigh_node = NULL; + + spin_lock_bh(&orig_node->neigh_list_lock); + rcu_assign_pointer(orig_node->router, neigh_node); + spin_unlock_bh(&orig_node->neigh_list_lock); + + /* decrease refcount of previous best neighbor */ + if (curr_router) + batadv_neigh_node_free_ref(curr_router); +} + +void batadv_update_route(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node) +{ + struct batadv_neigh_node *router = NULL; + + if (!orig_node) + goto out; + + router = batadv_orig_node_get_router(orig_node); + + if (router != neigh_node) + _batadv_update_route(bat_priv, orig_node, neigh_node); + +out: + if (router) + batadv_neigh_node_free_ref(router); +} + +/* caller must hold the neigh_list_lock */ +void batadv_bonding_candidate_del(struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node) +{ + /* this neighbor is not part of our candidate list */ + if (list_empty(&neigh_node->bonding_list)) + goto out; + + list_del_rcu(&neigh_node->bonding_list); + INIT_LIST_HEAD(&neigh_node->bonding_list); + batadv_neigh_node_free_ref(neigh_node); + atomic_dec(&orig_node->bond_candidates); + +out: + return; +} + +void batadv_bonding_candidate_add(struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node) +{ + struct batadv_neigh_node *tmp_neigh_node, *router = NULL; + uint8_t interference_candidate = 0; + + spin_lock_bh(&orig_node->neigh_list_lock); + + /* only consider if it has the same primary address ... */ + if (!batadv_compare_eth(orig_node->orig, + neigh_node->orig_node->primary_addr)) + goto candidate_del; + + router = batadv_orig_node_get_router(orig_node); + if (!router) + goto candidate_del; + + /* ... and is good enough to be considered */ + if (neigh_node->tq_avg < router->tq_avg - BATADV_BONDING_TQ_THRESHOLD) + goto candidate_del; + + /* check if we have another candidate with the same mac address or + * interface. If we do, we won't select this candidate because of + * possible interference. + */ + hlist_for_each_entry_rcu(tmp_neigh_node, + &orig_node->neigh_list, list) { + if (tmp_neigh_node == neigh_node) + continue; + + /* we only care if the other candidate is even + * considered as candidate. + */ + if (list_empty(&tmp_neigh_node->bonding_list)) + continue; + + if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) || + (batadv_compare_eth(neigh_node->addr, + tmp_neigh_node->addr))) { + interference_candidate = 1; + break; + } + } + + /* don't care further if it is an interference candidate */ + if (interference_candidate) + goto candidate_del; + + /* this neighbor already is part of our candidate list */ + if (!list_empty(&neigh_node->bonding_list)) + goto out; + + if (!atomic_inc_not_zero(&neigh_node->refcount)) + goto out; + + list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list); + atomic_inc(&orig_node->bond_candidates); + goto out; + +candidate_del: + batadv_bonding_candidate_del(orig_node, neigh_node); + +out: + spin_unlock_bh(&orig_node->neigh_list_lock); + + if (router) + batadv_neigh_node_free_ref(router); +} + +/* copy primary address for bonding */ +void +batadv_bonding_save_primary(const struct batadv_orig_node *orig_node, + struct batadv_orig_node *orig_neigh_node, + const struct batadv_ogm_packet *batman_ogm_packet) +{ + if (!(batman_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP)) + return; + + memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN); +} + +/* checks whether the host restarted and is in the protection time. + * returns: + * 0 if the packet is to be accepted + * 1 if the packet is to be ignored. + */ +int batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff, + unsigned long *last_reset) +{ + if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE || + seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) { + if (!batadv_has_timed_out(*last_reset, + BATADV_RESET_PROTECTION_MS)) + return 1; + + *last_reset = jiffies; + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "old packet received, start protection\n"); + } + + return 0; +} + +bool batadv_check_management_packet(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface, + int header_len) +{ + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, header_len))) + return false; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with broadcast indication but unicast recipient */ + if (!is_broadcast_ether_addr(ethhdr->h_dest)) + return false; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + return false; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, 0) < 0) + return false; + + /* keep skb linear */ + if (skb_linearize(skb) < 0) + return false; + + return true; +} + +static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, + struct sk_buff *skb, size_t icmp_len) +{ + struct batadv_hard_iface *primary_if = NULL; + struct batadv_orig_node *orig_node = NULL; + struct batadv_icmp_packet_rr *icmp_packet; + int ret = NET_RX_DROP; + + icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; + + /* add data to device queue */ + if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { + batadv_socket_receive_packet(icmp_packet, icmp_len); + goto out; + } + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* answer echo request (ping) */ + /* get routing information */ + orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); + if (!orig_node) + goto out; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, ETH_HLEN) < 0) + goto out; + + icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; + + memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); + memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN); + icmp_packet->msg_type = BATADV_ECHO_REPLY; + icmp_packet->header.ttl = BATADV_TTL; + + if (batadv_send_skb_to_orig(skb, orig_node, NULL)) + ret = NET_RX_SUCCESS; + +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + if (orig_node) + batadv_orig_node_free_ref(orig_node); + return ret; +} + +static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct batadv_hard_iface *primary_if = NULL; + struct batadv_orig_node *orig_node = NULL; + struct batadv_icmp_packet *icmp_packet; + int ret = NET_RX_DROP; + + icmp_packet = (struct batadv_icmp_packet *)skb->data; + + /* send TTL exceeded if packet is an echo request (traceroute) */ + if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { + pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n", + icmp_packet->orig, icmp_packet->dst); + goto out; + } + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* get routing information */ + orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); + if (!orig_node) + goto out; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, ETH_HLEN) < 0) + goto out; + + icmp_packet = (struct batadv_icmp_packet *)skb->data; + + memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); + memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN); + icmp_packet->msg_type = BATADV_TTL_EXCEEDED; + icmp_packet->header.ttl = BATADV_TTL; + + if (batadv_send_skb_to_orig(skb, orig_node, NULL)) + ret = NET_RX_SUCCESS; + +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + if (orig_node) + batadv_orig_node_free_ref(orig_node); + return ret; +} + + +int batadv_recv_icmp_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_icmp_packet_rr *icmp_packet; + struct ethhdr *ethhdr; + struct batadv_orig_node *orig_node = NULL; + int hdr_size = sizeof(struct batadv_icmp_packet); + int ret = NET_RX_DROP; + + /* we truncate all incoming icmp packets if they don't match our size */ + if (skb->len >= sizeof(struct batadv_icmp_packet_rr)) + hdr_size = sizeof(struct batadv_icmp_packet_rr); + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, hdr_size))) + goto out; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with unicast indication but broadcast recipient */ + if (is_broadcast_ether_addr(ethhdr->h_dest)) + goto out; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + goto out; + + /* not for me */ + if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) + goto out; + + icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; + + /* add record route information if not full */ + if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) && + (icmp_packet->rr_cur < BATADV_RR_LEN)) { + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]), + ethhdr->h_dest, ETH_ALEN); + icmp_packet->rr_cur++; + } + + /* packet for me */ + if (batadv_is_my_mac(bat_priv, icmp_packet->dst)) + return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size); + + /* TTL exceeded */ + if (icmp_packet->header.ttl < 2) + return batadv_recv_icmp_ttl_exceeded(bat_priv, skb); + + /* get routing information */ + orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst); + if (!orig_node) + goto out; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, ETH_HLEN) < 0) + goto out; + + icmp_packet = (struct batadv_icmp_packet_rr *)skb->data; + + /* decrement ttl */ + icmp_packet->header.ttl--; + + /* route it */ + if (batadv_send_skb_to_orig(skb, orig_node, recv_if)) + ret = NET_RX_SUCCESS; + +out: + if (orig_node) + batadv_orig_node_free_ref(orig_node); + return ret; +} + +/* In the bonding case, send the packets in a round + * robin fashion over the remaining interfaces. + * + * This method rotates the bonding list and increases the + * returned router's refcount. + */ +static struct batadv_neigh_node * +batadv_find_bond_router(struct batadv_orig_node *primary_orig, + const struct batadv_hard_iface *recv_if) +{ + struct batadv_neigh_node *tmp_neigh_node; + struct batadv_neigh_node *router = NULL, *first_candidate = NULL; + + rcu_read_lock(); + list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list, + bonding_list) { + if (!first_candidate) + first_candidate = tmp_neigh_node; + + /* recv_if == NULL on the first node. */ + if (tmp_neigh_node->if_incoming == recv_if) + continue; + + if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) + continue; + + router = tmp_neigh_node; + break; + } + + /* use the first candidate if nothing was found. */ + if (!router && first_candidate && + atomic_inc_not_zero(&first_candidate->refcount)) + router = first_candidate; + + if (!router) + goto out; + + /* selected should point to the next element + * after the current router + */ + spin_lock_bh(&primary_orig->neigh_list_lock); + /* this is a list_move(), which unfortunately + * does not exist as rcu version + */ + list_del_rcu(&primary_orig->bond_list); + list_add_rcu(&primary_orig->bond_list, + &router->bonding_list); + spin_unlock_bh(&primary_orig->neigh_list_lock); + +out: + rcu_read_unlock(); + return router; +} + +/* Interface Alternating: Use the best of the + * remaining candidates which are not using + * this interface. + * + * Increases the returned router's refcount + */ +static struct batadv_neigh_node * +batadv_find_ifalter_router(struct batadv_orig_node *primary_orig, + const struct batadv_hard_iface *recv_if) +{ + struct batadv_neigh_node *tmp_neigh_node; + struct batadv_neigh_node *router = NULL, *first_candidate = NULL; + + rcu_read_lock(); + list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list, + bonding_list) { + if (!first_candidate) + first_candidate = tmp_neigh_node; + + /* recv_if == NULL on the first node. */ + if (tmp_neigh_node->if_incoming == recv_if) + continue; + + if (router && tmp_neigh_node->tq_avg <= router->tq_avg) + continue; + + if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) + continue; + + /* decrement refcount of previously selected router */ + if (router) + batadv_neigh_node_free_ref(router); + + /* we found a better router (or at least one valid router) */ + router = tmp_neigh_node; + } + + /* use the first candidate if nothing was found. */ + if (!router && first_candidate && + atomic_inc_not_zero(&first_candidate->refcount)) + router = first_candidate; + + rcu_read_unlock(); + return router; +} + +/** + * batadv_check_unicast_packet - Check for malformed unicast packets + * @bat_priv: the bat priv with all the soft interface information + * @skb: packet to check + * @hdr_size: size of header to pull + * + * Check for short header and bad addresses in given packet. Returns negative + * value when check fails and 0 otherwise. The negative value depends on the + * reason: -ENODATA for bad header, -EBADR for broadcast destination or source, + * and -EREMOTE for non-local (other host) destination. + */ +static int batadv_check_unicast_packet(struct batadv_priv *bat_priv, + struct sk_buff *skb, int hdr_size) +{ + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, hdr_size))) + return -ENODATA; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with unicast indication but broadcast recipient */ + if (is_broadcast_ether_addr(ethhdr->h_dest)) + return -EBADR; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + return -EBADR; + + /* not for me */ + if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) + return -EREMOTE; + + return 0; +} + +int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_tt_query_packet *tt_query; + uint16_t tt_size; + int hdr_size = sizeof(*tt_query); + char tt_flag; + size_t packet_size; + + if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) + return NET_RX_DROP; + + /* I could need to modify it */ + if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0) + goto out; + + tt_query = (struct batadv_tt_query_packet *)skb->data; + + switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) { + case BATADV_TT_REQUEST: + batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX); + + /* If we cannot provide an answer the tt_request is + * forwarded + */ + if (!batadv_send_tt_response(bat_priv, tt_query)) { + if (tt_query->flags & BATADV_TT_FULL_TABLE) + tt_flag = 'F'; + else + tt_flag = '.'; + + batadv_dbg(BATADV_DBG_TT, bat_priv, + "Routing TT_REQUEST to %pM [%c]\n", + tt_query->dst, + tt_flag); + return batadv_route_unicast_packet(skb, recv_if); + } + break; + case BATADV_TT_RESPONSE: + batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX); + + if (batadv_is_my_mac(bat_priv, tt_query->dst)) { + /* packet needs to be linearized to access the TT + * changes + */ + if (skb_linearize(skb) < 0) + goto out; + /* skb_linearize() possibly changed skb->data */ + tt_query = (struct batadv_tt_query_packet *)skb->data; + + tt_size = batadv_tt_len(ntohs(tt_query->tt_data)); + + /* Ensure we have all the claimed data */ + packet_size = sizeof(struct batadv_tt_query_packet); + packet_size += tt_size; + if (unlikely(skb_headlen(skb) < packet_size)) + goto out; + + batadv_handle_tt_response(bat_priv, tt_query); + } else { + if (tt_query->flags & BATADV_TT_FULL_TABLE) + tt_flag = 'F'; + else + tt_flag = '.'; + batadv_dbg(BATADV_DBG_TT, bat_priv, + "Routing TT_RESPONSE to %pM [%c]\n", + tt_query->dst, + tt_flag); + return batadv_route_unicast_packet(skb, recv_if); + } + break; + } + +out: + /* returning NET_RX_DROP will make the caller function kfree the skb */ + return NET_RX_DROP; +} + +int batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_roam_adv_packet *roam_adv_packet; + struct batadv_orig_node *orig_node; + + if (batadv_check_unicast_packet(bat_priv, skb, + sizeof(*roam_adv_packet)) < 0) + goto out; + + batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX); + + roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data; + + if (!batadv_is_my_mac(bat_priv, roam_adv_packet->dst)) + return batadv_route_unicast_packet(skb, recv_if); + + /* check if it is a backbone gateway. we don't accept + * roaming advertisement from it, as it has the same + * entries as we have. + */ + if (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src)) + goto out; + + orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src); + if (!orig_node) + goto out; + + batadv_dbg(BATADV_DBG_TT, bat_priv, + "Received ROAMING_ADV from %pM (client %pM)\n", + roam_adv_packet->src, roam_adv_packet->client); + + batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client, + BATADV_TT_CLIENT_ROAM, + atomic_read(&orig_node->last_ttvn) + 1); + + batadv_orig_node_free_ref(orig_node); +out: + /* returning NET_RX_DROP will make the caller function kfree the skb */ + return NET_RX_DROP; +} + +/* find a suitable router for this originator, and use + * bonding if possible. increases the found neighbors + * refcount. + */ +struct batadv_neigh_node * +batadv_find_router(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node, + const struct batadv_hard_iface *recv_if) +{ + struct batadv_orig_node *primary_orig_node; + struct batadv_orig_node *router_orig; + struct batadv_neigh_node *router; + static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0}; + int bonding_enabled; + uint8_t *primary_addr; + + if (!orig_node) + return NULL; + + router = batadv_orig_node_get_router(orig_node); + if (!router) + goto err; + + /* without bonding, the first node should + * always choose the default router. + */ + bonding_enabled = atomic_read(&bat_priv->bonding); + + rcu_read_lock(); + /* select default router to output */ + router_orig = router->orig_node; + if (!router_orig) + goto err_unlock; + + if ((!recv_if) && (!bonding_enabled)) + goto return_router; + + primary_addr = router_orig->primary_addr; + + /* if we have something in the primary_addr, we can search + * for a potential bonding candidate. + */ + if (batadv_compare_eth(primary_addr, zero_mac)) + goto return_router; + + /* find the orig_node which has the primary interface. might + * even be the same as our router_orig in many cases + */ + if (batadv_compare_eth(primary_addr, router_orig->orig)) { + primary_orig_node = router_orig; + } else { + primary_orig_node = batadv_orig_hash_find(bat_priv, + primary_addr); + if (!primary_orig_node) + goto return_router; + + batadv_orig_node_free_ref(primary_orig_node); + } + + /* with less than 2 candidates, we can't do any + * bonding and prefer the original router. + */ + if (atomic_read(&primary_orig_node->bond_candidates) < 2) + goto return_router; + + /* all nodes between should choose a candidate which + * is is not on the interface where the packet came + * in. + */ + batadv_neigh_node_free_ref(router); + + if (bonding_enabled) + router = batadv_find_bond_router(primary_orig_node, recv_if); + else + router = batadv_find_ifalter_router(primary_orig_node, recv_if); + +return_router: + if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE) + goto err_unlock; + + rcu_read_unlock(); + return router; +err_unlock: + rcu_read_unlock(); +err: + if (router) + batadv_neigh_node_free_ref(router); + return NULL; +} + +static int batadv_route_unicast_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_orig_node *orig_node = NULL; + struct batadv_neigh_node *neigh_node = NULL; + struct batadv_unicast_packet *unicast_packet; + struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb); + int ret = NET_RX_DROP; + struct sk_buff *new_skb; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + + /* TTL exceeded */ + if (unicast_packet->header.ttl < 2) { + pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", + ethhdr->h_source, unicast_packet->dest); + goto out; + } + + /* get routing information */ + orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); + + if (!orig_node) + goto out; + + /* find_router() increases neigh_nodes refcount if found. */ + neigh_node = batadv_find_router(bat_priv, orig_node, recv_if); + + if (!neigh_node) + goto out; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, ETH_HLEN) < 0) + goto out; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + + if (unicast_packet->header.packet_type == BATADV_UNICAST && + atomic_read(&bat_priv->fragmentation) && + skb->len > neigh_node->if_incoming->net_dev->mtu) { + ret = batadv_frag_send_skb(skb, bat_priv, + neigh_node->if_incoming, + neigh_node->addr); + goto out; + } + + if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG && + batadv_frag_can_reassemble(skb, + neigh_node->if_incoming->net_dev->mtu)) { + ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb); + + if (ret == NET_RX_DROP) + goto out; + + /* packet was buffered for late merge */ + if (!new_skb) { + ret = NET_RX_SUCCESS; + goto out; + } + + skb = new_skb; + unicast_packet = (struct batadv_unicast_packet *)skb->data; + } + + /* decrement ttl */ + unicast_packet->header.ttl--; + + /* network code packet if possible */ + if (batadv_nc_skb_forward(skb, neigh_node, ethhdr)) { + ret = NET_RX_SUCCESS; + } else if (batadv_send_skb_to_orig(skb, orig_node, recv_if)) { + ret = NET_RX_SUCCESS; + + /* Update stats counter */ + batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); + batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, + skb->len + ETH_HLEN); + } + +out: + if (neigh_node) + batadv_neigh_node_free_ref(neigh_node); + if (orig_node) + batadv_orig_node_free_ref(orig_node); + return ret; +} + +/** + * batadv_reroute_unicast_packet - update the unicast header for re-routing + * @bat_priv: the bat priv with all the soft interface information + * @unicast_packet: the unicast header to be updated + * @dst_addr: the payload destination + * + * Search the translation table for dst_addr and update the unicast header with + * the new corresponding information (originator address where the destination + * client currently is and its known TTVN) + * + * Returns true if the packet header has been updated, false otherwise + */ +static bool +batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, + struct batadv_unicast_packet *unicast_packet, + uint8_t *dst_addr) +{ + struct batadv_orig_node *orig_node = NULL; + struct batadv_hard_iface *primary_if = NULL; + bool ret = false; + uint8_t *orig_addr, orig_ttvn; + + if (batadv_is_my_client(bat_priv, dst_addr)) { + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + orig_addr = primary_if->net_dev->dev_addr; + orig_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn); + } else { + orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr); + if (!orig_node) + goto out; + + if (batadv_compare_eth(orig_node->orig, unicast_packet->dest)) + goto out; + + orig_addr = orig_node->orig; + orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); + } + + /* update the packet header */ + memcpy(unicast_packet->dest, orig_addr, ETH_ALEN); + unicast_packet->ttvn = orig_ttvn; + + ret = true; +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + if (orig_node) + batadv_orig_node_free_ref(orig_node); + + return ret; +} + +static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, + struct sk_buff *skb, int hdr_len) { + uint8_t curr_ttvn, old_ttvn; + struct batadv_orig_node *orig_node; + struct ethhdr *ethhdr; + struct batadv_hard_iface *primary_if; + struct batadv_unicast_packet *unicast_packet; + int is_old_ttvn; + + /* check if there is enough data before accessing it */ + if (pskb_may_pull(skb, hdr_len + ETH_HLEN) < 0) + return 0; + + /* create a copy of the skb (in case of for re-routing) to modify it. */ + if (skb_cow(skb, sizeof(*unicast_packet)) < 0) + return 0; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + ethhdr = (struct ethhdr *)(skb->data + hdr_len); + + /* check if the destination client was served by this node and it is now + * roaming. In this case, it means that the node has got a ROAM_ADV + * message and that it knows the new destination in the mesh to re-route + * the packet to + */ + if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest)) { + if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + ethhdr->h_dest)) + net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, + bat_priv, + "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n", + unicast_packet->dest, + ethhdr->h_dest); + /* at this point the mesh destination should have been + * substituted with the originator address found in the global + * table. If not, let the packet go untouched anyway because + * there is nothing the node can do + */ + return 1; + } + + /* retrieve the TTVN known by this node for the packet destination. This + * value is used later to check if the node which sent (or re-routed + * last time) the packet had an updated information or not + */ + curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn); + if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) { + orig_node = batadv_orig_hash_find(bat_priv, + unicast_packet->dest); + /* if it is not possible to find the orig_node representing the + * destination, the packet can immediately be dropped as it will + * not be possible to deliver it + */ + if (!orig_node) + return 0; + + curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); + batadv_orig_node_free_ref(orig_node); + } + + /* check if the TTVN contained in the packet is fresher than what the + * node knows + */ + is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); + if (!is_old_ttvn) + return 1; + + old_ttvn = unicast_packet->ttvn; + /* the packet was forged based on outdated network information. Its + * destination can possibly be updated and forwarded towards the new + * target host + */ + if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + ethhdr->h_dest)) { + net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv, + "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", + unicast_packet->dest, ethhdr->h_dest, + old_ttvn, curr_ttvn); + return 1; + } + + /* the packet has not been re-routed: either the destination is + * currently served by this node or there is no destination at all and + * it is possible to drop the packet + */ + if (!batadv_is_my_client(bat_priv, ethhdr->h_dest)) + return 0; + + /* update the header in order to let the packet be delivered to this + * node's soft interface + */ + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + return 0; + + memcpy(unicast_packet->dest, primary_if->net_dev->dev_addr, ETH_ALEN); + + batadv_hardif_free_ref(primary_if); + + unicast_packet->ttvn = curr_ttvn; + + return 1; +} + +int batadv_recv_unicast_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_unicast_packet *unicast_packet; + struct batadv_unicast_4addr_packet *unicast_4addr_packet; + uint8_t *orig_addr; + struct batadv_orig_node *orig_node = NULL; + int check, hdr_size = sizeof(*unicast_packet); + bool is4addr; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; + + is4addr = unicast_packet->header.packet_type == BATADV_UNICAST_4ADDR; + /* the caller function should have already pulled 2 bytes */ + if (is4addr) + hdr_size = sizeof(*unicast_4addr_packet); + + /* function returns -EREMOTE for promiscuous packets */ + check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); + + /* Even though the packet is not for us, we might save it to use for + * decoding a later received coded packet + */ + if (check == -EREMOTE) + batadv_nc_skb_store_sniffed_unicast(bat_priv, skb); + + if (check < 0) + return NET_RX_DROP; + if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) + return NET_RX_DROP; + + /* packet for me */ + if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { + if (is4addr) { + batadv_dat_inc_counter(bat_priv, + unicast_4addr_packet->subtype); + orig_addr = unicast_4addr_packet->src; + orig_node = batadv_orig_hash_find(bat_priv, orig_addr); + } + + if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, + hdr_size)) + goto rx_success; + if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, + hdr_size)) + goto rx_success; + + batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, + orig_node); + +rx_success: + if (orig_node) + batadv_orig_node_free_ref(orig_node); + + return NET_RX_SUCCESS; + } + + return batadv_route_unicast_packet(skb, recv_if); +} + +int batadv_recv_ucast_frag_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_unicast_frag_packet *unicast_packet; + int hdr_size = sizeof(*unicast_packet); + struct sk_buff *new_skb = NULL; + int ret; + + if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) + return NET_RX_DROP; + + if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) + return NET_RX_DROP; + + unicast_packet = (struct batadv_unicast_frag_packet *)skb->data; + + /* packet for me */ + if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { + ret = batadv_frag_reassemble_skb(skb, bat_priv, &new_skb); + + if (ret == NET_RX_DROP) + return NET_RX_DROP; + + /* packet was buffered for late merge */ + if (!new_skb) + return NET_RX_SUCCESS; + + if (batadv_dat_snoop_incoming_arp_request(bat_priv, new_skb, + hdr_size)) + goto rx_success; + if (batadv_dat_snoop_incoming_arp_reply(bat_priv, new_skb, + hdr_size)) + goto rx_success; + + batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if, + sizeof(struct batadv_unicast_packet), NULL); + +rx_success: + return NET_RX_SUCCESS; + } + + return batadv_route_unicast_packet(skb, recv_if); +} + + +int batadv_recv_bcast_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct batadv_orig_node *orig_node = NULL; + struct batadv_bcast_packet *bcast_packet; + struct ethhdr *ethhdr; + int hdr_size = sizeof(*bcast_packet); + int ret = NET_RX_DROP; + int32_t seq_diff; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, hdr_size))) + goto out; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with broadcast indication but unicast recipient */ + if (!is_broadcast_ether_addr(ethhdr->h_dest)) + goto out; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + goto out; + + /* ignore broadcasts sent by myself */ + if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) + goto out; + + bcast_packet = (struct batadv_bcast_packet *)skb->data; + + /* ignore broadcasts originated by myself */ + if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) + goto out; + + if (bcast_packet->header.ttl < 2) + goto out; + + orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig); + + if (!orig_node) + goto out; + + spin_lock_bh(&orig_node->bcast_seqno_lock); + + /* check whether the packet is a duplicate */ + if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno, + ntohl(bcast_packet->seqno))) + goto spin_unlock; + + seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno; + + /* check whether the packet is old and the host just restarted. */ + if (batadv_window_protected(bat_priv, seq_diff, + &orig_node->bcast_seqno_reset)) + goto spin_unlock; + + /* mark broadcast in flood history, update window position + * if required. + */ + if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1)) + orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno); + + spin_unlock_bh(&orig_node->bcast_seqno_lock); + + /* check whether this has been sent by another originator before */ + if (batadv_bla_check_bcast_duplist(bat_priv, skb)) + goto out; + + /* rebroadcast packet */ + batadv_add_bcast_packet_to_list(bat_priv, skb, 1); + + /* don't hand the broadcast up if it is from an originator + * from the same backbone. + */ + if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) + goto out; + + if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) + goto rx_success; + if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) + goto rx_success; + + /* broadcast for me */ + batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, + orig_node); + +rx_success: + ret = NET_RX_SUCCESS; + goto out; + +spin_unlock: + spin_unlock_bh(&orig_node->bcast_seqno_lock); +out: + if (orig_node) + batadv_orig_node_free_ref(orig_node); + return ret; +} + +int batadv_recv_vis_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if) +{ + struct batadv_vis_packet *vis_packet; + struct ethhdr *ethhdr; + struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); + int hdr_size = sizeof(*vis_packet); + + /* keep skb linear */ + if (skb_linearize(skb) < 0) + return NET_RX_DROP; + + if (unlikely(!pskb_may_pull(skb, hdr_size))) + return NET_RX_DROP; + + vis_packet = (struct batadv_vis_packet *)skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* not for me */ + if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) + return NET_RX_DROP; + + /* ignore own packets */ + if (batadv_is_my_mac(bat_priv, vis_packet->vis_orig)) + return NET_RX_DROP; + + if (batadv_is_my_mac(bat_priv, vis_packet->sender_orig)) + return NET_RX_DROP; + + switch (vis_packet->vis_type) { + case BATADV_VIS_TYPE_SERVER_SYNC: + batadv_receive_server_sync_packet(bat_priv, vis_packet, + skb_headlen(skb)); + break; + + case BATADV_VIS_TYPE_CLIENT_UPDATE: + batadv_receive_client_update_packet(bat_priv, vis_packet, + skb_headlen(skb)); + break; + + default: /* ignore unknown packet */ + break; + } + + /* We take a copy of the data in the packet, so we should + * always free the skbuf. + */ + return NET_RX_DROP; +} |