| /* Copyright (C) 2007-2012 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" |
| |
| 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_node *node; |
| 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, 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 hlist_node *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, 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_neigh_node *router = 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; |
| |
| router = batadv_orig_node_get_router(orig_node); |
| if (!router) |
| 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; |
| |
| batadv_send_skb_packet(skb, router->if_incoming, router->addr); |
| ret = NET_RX_SUCCESS; |
| |
| out: |
| if (primary_if) |
| batadv_hardif_free_ref(primary_if); |
| if (router) |
| batadv_neigh_node_free_ref(router); |
| 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_neigh_node *router = 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; |
| |
| router = batadv_orig_node_get_router(orig_node); |
| if (!router) |
| 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; |
| |
| batadv_send_skb_packet(skb, router->if_incoming, router->addr); |
| ret = NET_RX_SUCCESS; |
| |
| out: |
| if (primary_if) |
| batadv_hardif_free_ref(primary_if); |
| if (router) |
| batadv_neigh_node_free_ref(router); |
| 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; |
| struct batadv_neigh_node *router = 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(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(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; |
| |
| router = batadv_orig_node_get_router(orig_node); |
| if (!router) |
| 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 */ |
| batadv_send_skb_packet(skb, router->if_incoming, router->addr); |
| ret = NET_RX_SUCCESS; |
| |
| out: |
| if (router) |
| batadv_neigh_node_free_ref(router); |
| 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; |
| } |
| |
| static int batadv_check_unicast_packet(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 -1; |
| |
| ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| |
| /* packet with unicast indication but broadcast recipient */ |
| if (is_broadcast_ether_addr(ethhdr->h_dest)) |
| return -1; |
| |
| /* packet with broadcast sender address */ |
| if (is_broadcast_ether_addr(ethhdr->h_source)) |
| return -1; |
| |
| /* not for me */ |
| if (!batadv_is_my_mac(ethhdr->h_dest)) |
| return -1; |
| |
| 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(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(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(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(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); |
| |
| /* Roaming phase starts: I have new information but the ttvn has not |
| * been incremented yet. This flag will make me check all the incoming |
| * packets for the correct destination. |
| */ |
| bat_priv->tt.poss_change = true; |
| |
| 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--; |
| |
| /* Update stats counter */ |
| batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); |
| batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, |
| skb->len + ETH_HLEN); |
| |
| /* route it */ |
| batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr); |
| ret = NET_RX_SUCCESS; |
| |
| out: |
| if (neigh_node) |
| batadv_neigh_node_free_ref(neigh_node); |
| 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) { |
| uint8_t curr_ttvn; |
| struct batadv_orig_node *orig_node; |
| struct ethhdr *ethhdr; |
| struct batadv_hard_iface *primary_if; |
| struct batadv_unicast_packet *unicast_packet; |
| bool tt_poss_change; |
| int is_old_ttvn; |
| |
| /* I could need to modify it */ |
| if (skb_cow(skb, sizeof(struct batadv_unicast_packet)) < 0) |
| return 0; |
| |
| unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| |
| if (batadv_is_my_mac(unicast_packet->dest)) { |
| tt_poss_change = bat_priv->tt.poss_change; |
| curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn); |
| } else { |
| orig_node = batadv_orig_hash_find(bat_priv, |
| unicast_packet->dest); |
| |
| if (!orig_node) |
| return 0; |
| |
| curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); |
| tt_poss_change = orig_node->tt_poss_change; |
| batadv_orig_node_free_ref(orig_node); |
| } |
| |
| /* Check whether I have to reroute the packet */ |
| is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); |
| if (is_old_ttvn || tt_poss_change) { |
| /* check if there is enough data before accessing it */ |
| if (pskb_may_pull(skb, sizeof(struct batadv_unicast_packet) + |
| ETH_HLEN) < 0) |
| return 0; |
| |
| ethhdr = (struct ethhdr *)(skb->data + sizeof(*unicast_packet)); |
| |
| /* we don't have an updated route for this client, so we should |
| * not try to reroute the packet!! |
| */ |
| if (batadv_tt_global_client_is_roaming(bat_priv, |
| ethhdr->h_dest)) |
| return 1; |
| |
| orig_node = batadv_transtable_search(bat_priv, NULL, |
| ethhdr->h_dest); |
| |
| if (!orig_node) { |
| if (!batadv_is_my_client(bat_priv, ethhdr->h_dest)) |
| return 0; |
| 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); |
| } else { |
| memcpy(unicast_packet->dest, orig_node->orig, |
| ETH_ALEN); |
| curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn); |
| batadv_orig_node_free_ref(orig_node); |
| } |
| |
| batadv_dbg(BATADV_DBG_ROUTES, bat_priv, |
| "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n", |
| unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest, |
| unicast_packet->dest); |
| |
| 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; |
| int hdr_size = sizeof(*unicast_packet); |
| |
| if (batadv_check_unicast_packet(skb, hdr_size) < 0) |
| return NET_RX_DROP; |
| |
| if (!batadv_check_unicast_ttvn(bat_priv, skb)) |
| return NET_RX_DROP; |
| |
| unicast_packet = (struct batadv_unicast_packet *)skb->data; |
| |
| /* packet for me */ |
| if (batadv_is_my_mac(unicast_packet->dest)) { |
| batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, |
| NULL); |
| |
| 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(skb, hdr_size) < 0) |
| return NET_RX_DROP; |
| |
| if (!batadv_check_unicast_ttvn(bat_priv, skb)) |
| return NET_RX_DROP; |
| |
| unicast_packet = (struct batadv_unicast_frag_packet *)skb->data; |
| |
| /* packet for me */ |
| if (batadv_is_my_mac(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; |
| |
| batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if, |
| sizeof(struct batadv_unicast_packet), NULL); |
| 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(ethhdr->h_source)) |
| goto out; |
| |
| bcast_packet = (struct batadv_bcast_packet *)skb->data; |
| |
| /* ignore broadcasts originated by myself */ |
| if (batadv_is_my_mac(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); |
| |
| /* keep skb linear for crc calculation */ |
| if (skb_linearize(skb) < 0) |
| goto out; |
| |
| bcast_packet = (struct batadv_bcast_packet *)skb->data; |
| |
| /* check whether this has been sent by another originator before */ |
| if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, skb->len)) |
| 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; |
| |
| /* broadcast for me */ |
| batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, |
| orig_node); |
| 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(ethhdr->h_dest)) |
| return NET_RX_DROP; |
| |
| /* ignore own packets */ |
| if (batadv_is_my_mac(vis_packet->vis_orig)) |
| return NET_RX_DROP; |
| |
| if (batadv_is_my_mac(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; |
| } |