diff options
Diffstat (limited to 'net/batman-adv/routing.c')
| -rw-r--r-- | net/batman-adv/routing.c | 1132 |
1 files changed, 1132 insertions, 0 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c new file mode 100644 index 00000000..8df3a1ff --- /dev/null +++ b/net/batman-adv/routing.c @@ -0,0 +1,1132 @@ +/* + * 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" + +void slide_own_bcast_window(struct hard_iface *hard_iface) +{ + struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + struct hashtable_t *hash = bat_priv->orig_hash; + struct hlist_node *node; + struct hlist_head *head; + struct orig_node *orig_node; + unsigned long *word; + uint32_t i; + size_t word_index; + + 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 * NUM_WORDS; + word = &(orig_node->bcast_own[word_index]); + + bit_get_packet(bat_priv, word, 1, 0); + orig_node->bcast_own_sum[hard_iface->if_num] = + bit_packet_count(word); + spin_unlock_bh(&orig_node->ogm_cnt_lock); + } + rcu_read_unlock(); + } +} + +static void _update_route(struct bat_priv *bat_priv, + struct orig_node *orig_node, + struct neigh_node *neigh_node) +{ + struct neigh_node *curr_router; + + curr_router = orig_node_get_router(orig_node); + + /* route deleted */ + if ((curr_router) && (!neigh_node)) { + bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n", + orig_node->orig); + tt_global_del_orig(bat_priv, orig_node, + "Deleted route towards originator"); + + /* route added */ + } else if ((!curr_router) && (neigh_node)) { + + bat_dbg(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) { + bat_dbg(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) + 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) + neigh_node_free_ref(curr_router); +} + +void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node, + struct neigh_node *neigh_node) +{ + struct neigh_node *router = NULL; + + if (!orig_node) + goto out; + + router = orig_node_get_router(orig_node); + + if (router != neigh_node) + _update_route(bat_priv, orig_node, neigh_node); + +out: + if (router) + neigh_node_free_ref(router); +} + +/* caller must hold the neigh_list_lock */ +void bonding_candidate_del(struct orig_node *orig_node, + struct 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); + neigh_node_free_ref(neigh_node); + atomic_dec(&orig_node->bond_candidates); + +out: + return; +} + +void bonding_candidate_add(struct orig_node *orig_node, + struct neigh_node *neigh_node) +{ + struct hlist_node *node; + struct 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 (!compare_eth(orig_node->orig, + neigh_node->orig_node->primary_addr)) + goto candidate_del; + + router = 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 - 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) || + (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: + bonding_candidate_del(orig_node, neigh_node); + +out: + spin_unlock_bh(&orig_node->neigh_list_lock); + + if (router) + neigh_node_free_ref(router); +} + +/* copy primary address for bonding */ +void bonding_save_primary(const struct orig_node *orig_node, + struct orig_node *orig_neigh_node, + const struct batman_ogm_packet *batman_ogm_packet) +{ + if (!(batman_ogm_packet->flags & 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 window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff, + unsigned long *last_reset) +{ + if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) || + (seq_num_diff >= EXPECTED_SEQNO_RANGE)) { + if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) { + + *last_reset = jiffies; + bat_dbg(DBG_BATMAN, bat_priv, + "old packet received, start protection\n"); + + return 0; + } else { + return 1; + } + } + return 0; +} + +int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface) +{ + struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN))) + return NET_RX_DROP; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with broadcast indication but unicast recipient */ + if (!is_broadcast_ether_addr(ethhdr->h_dest)) + return NET_RX_DROP; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + return NET_RX_DROP; + + /* create a copy of the skb, if needed, to modify it. */ + if (skb_cow(skb, 0) < 0) + return NET_RX_DROP; + + /* keep skb linear */ + if (skb_linearize(skb) < 0) + return NET_RX_DROP; + + bat_priv->bat_algo_ops->bat_ogm_receive(hard_iface, skb); + + kfree_skb(skb); + return NET_RX_SUCCESS; +} + +static int recv_my_icmp_packet(struct bat_priv *bat_priv, + struct sk_buff *skb, size_t icmp_len) +{ + struct hard_iface *primary_if = NULL; + struct orig_node *orig_node = NULL; + struct neigh_node *router = NULL; + struct icmp_packet_rr *icmp_packet; + int ret = NET_RX_DROP; + + icmp_packet = (struct icmp_packet_rr *)skb->data; + + /* add data to device queue */ + if (icmp_packet->msg_type != ECHO_REQUEST) { + bat_socket_receive_packet(icmp_packet, icmp_len); + goto out; + } + + primary_if = primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* answer echo request (ping) */ + /* get routing information */ + orig_node = orig_hash_find(bat_priv, icmp_packet->orig); + if (!orig_node) + goto out; + + router = 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, sizeof(struct ethhdr)) < 0) + goto out; + + icmp_packet = (struct 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 = ECHO_REPLY; + icmp_packet->header.ttl = TTL; + + send_skb_packet(skb, router->if_incoming, router->addr); + ret = NET_RX_SUCCESS; + +out: + if (primary_if) + hardif_free_ref(primary_if); + if (router) + neigh_node_free_ref(router); + if (orig_node) + orig_node_free_ref(orig_node); + return ret; +} + +static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv, + struct sk_buff *skb) +{ + struct hard_iface *primary_if = NULL; + struct orig_node *orig_node = NULL; + struct neigh_node *router = NULL; + struct icmp_packet *icmp_packet; + int ret = NET_RX_DROP; + + icmp_packet = (struct icmp_packet *)skb->data; + + /* send TTL exceeded if packet is an echo request (traceroute) */ + if (icmp_packet->msg_type != 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 = primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* get routing information */ + orig_node = orig_hash_find(bat_priv, icmp_packet->orig); + if (!orig_node) + goto out; + + router = 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, sizeof(struct ethhdr)) < 0) + goto out; + + icmp_packet = (struct 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 = TTL_EXCEEDED; + icmp_packet->header.ttl = TTL; + + send_skb_packet(skb, router->if_incoming, router->addr); + ret = NET_RX_SUCCESS; + +out: + if (primary_if) + hardif_free_ref(primary_if); + if (router) + neigh_node_free_ref(router); + if (orig_node) + orig_node_free_ref(orig_node); + return ret; +} + + +int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct icmp_packet_rr *icmp_packet; + struct ethhdr *ethhdr; + struct orig_node *orig_node = NULL; + struct neigh_node *router = NULL; + int hdr_size = sizeof(struct 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 icmp_packet_rr)) + hdr_size = sizeof(struct 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 (!is_my_mac(ethhdr->h_dest)) + goto out; + + icmp_packet = (struct icmp_packet_rr *)skb->data; + + /* add record route information if not full */ + if ((hdr_size == sizeof(struct icmp_packet_rr)) && + (icmp_packet->rr_cur < BAT_RR_LEN)) { + memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]), + ethhdr->h_dest, ETH_ALEN); + icmp_packet->rr_cur++; + } + + /* packet for me */ + if (is_my_mac(icmp_packet->dst)) + return recv_my_icmp_packet(bat_priv, skb, hdr_size); + + /* TTL exceeded */ + if (icmp_packet->header.ttl < 2) + return recv_icmp_ttl_exceeded(bat_priv, skb); + + /* get routing information */ + orig_node = orig_hash_find(bat_priv, icmp_packet->dst); + if (!orig_node) + goto out; + + router = 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, sizeof(struct ethhdr)) < 0) + goto out; + + icmp_packet = (struct icmp_packet_rr *)skb->data; + + /* decrement ttl */ + icmp_packet->header.ttl--; + + /* route it */ + send_skb_packet(skb, router->if_incoming, router->addr); + ret = NET_RX_SUCCESS; + +out: + if (router) + neigh_node_free_ref(router); + if (orig_node) + 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 neigh_node *find_bond_router(struct orig_node *primary_orig, + const struct hard_iface *recv_if) +{ + struct neigh_node *tmp_neigh_node; + struct 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 neigh_node *find_ifalter_router(struct orig_node *primary_orig, + const struct hard_iface *recv_if) +{ + struct neigh_node *tmp_neigh_node; + struct 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; + + /* if we don't have a router yet + * or this one is better, choose it. */ + if ((!router) || + (tmp_neigh_node->tq_avg > router->tq_avg)) { + /* decrement refcount of + * previously selected router */ + if (router) + neigh_node_free_ref(router); + + router = tmp_neigh_node; + atomic_inc_not_zero(&router->refcount); + } + + neigh_node_free_ref(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; +} + +int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct tt_query_packet *tt_query; + uint16_t tt_len; + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet)))) + goto out; + + /* I could need to modify it */ + if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0) + 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; + + tt_query = (struct tt_query_packet *)skb->data; + + tt_query->tt_data = ntohs(tt_query->tt_data); + + switch (tt_query->flags & TT_QUERY_TYPE_MASK) { + case TT_REQUEST: + /* If we cannot provide an answer the tt_request is + * forwarded */ + if (!send_tt_response(bat_priv, tt_query)) { + bat_dbg(DBG_TT, bat_priv, + "Routing TT_REQUEST to %pM [%c]\n", + tt_query->dst, + (tt_query->flags & TT_FULL_TABLE ? 'F' : '.')); + tt_query->tt_data = htons(tt_query->tt_data); + return route_unicast_packet(skb, recv_if); + } + break; + case TT_RESPONSE: + if (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 tt_query_packet *)skb->data; + + tt_len = tt_query->tt_data * sizeof(struct tt_change); + + /* Ensure we have all the claimed data */ + if (unlikely(skb_headlen(skb) < + sizeof(struct tt_query_packet) + tt_len)) + goto out; + + handle_tt_response(bat_priv, tt_query); + } else { + bat_dbg(DBG_TT, bat_priv, + "Routing TT_RESPONSE to %pM [%c]\n", + tt_query->dst, + (tt_query->flags & TT_FULL_TABLE ? 'F' : '.')); + tt_query->tt_data = htons(tt_query->tt_data); + return 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 recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct roam_adv_packet *roam_adv_packet; + struct orig_node *orig_node; + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet)))) + 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; + + roam_adv_packet = (struct roam_adv_packet *)skb->data; + + if (!is_my_mac(roam_adv_packet->dst)) + return route_unicast_packet(skb, recv_if); + + orig_node = orig_hash_find(bat_priv, roam_adv_packet->src); + if (!orig_node) + goto out; + + bat_dbg(DBG_TT, bat_priv, + "Received ROAMING_ADV from %pM (client %pM)\n", + roam_adv_packet->src, roam_adv_packet->client); + + tt_global_add(bat_priv, orig_node, roam_adv_packet->client, + atomic_read(&orig_node->last_ttvn) + 1, true, false); + + /* 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; + + 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 neigh_node *find_router(struct bat_priv *bat_priv, + struct orig_node *orig_node, + const struct hard_iface *recv_if) +{ + struct orig_node *primary_orig_node; + struct orig_node *router_orig; + struct neigh_node *router; + static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0}; + int bonding_enabled; + + if (!orig_node) + return NULL; + + router = 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; + + /* if we have something in the primary_addr, we can search + * for a potential bonding candidate. */ + if (compare_eth(router_orig->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 (compare_eth(router_orig->primary_addr, router_orig->orig)) { + primary_orig_node = router_orig; + } else { + primary_orig_node = orig_hash_find(bat_priv, + router_orig->primary_addr); + if (!primary_orig_node) + goto return_router; + + 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. */ + + neigh_node_free_ref(router); + + if (bonding_enabled) + router = find_bond_router(primary_orig_node, recv_if); + else + router = find_ifalter_router(primary_orig_node, recv_if); + +return_router: + if (router && router->if_incoming->if_status != IF_ACTIVE) + goto err_unlock; + + rcu_read_unlock(); + return router; +err_unlock: + rcu_read_unlock(); +err: + if (router) + neigh_node_free_ref(router); + return NULL; +} + +static int 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 (!is_my_mac(ethhdr->h_dest)) + return -1; + + return 0; +} + +int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct orig_node *orig_node = NULL; + struct neigh_node *neigh_node = NULL; + struct 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 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 = orig_hash_find(bat_priv, unicast_packet->dest); + + if (!orig_node) + goto out; + + /* find_router() increases neigh_nodes refcount if found. */ + neigh_node = 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, sizeof(struct ethhdr)) < 0) + goto out; + + unicast_packet = (struct unicast_packet *)skb->data; + + if (unicast_packet->header.packet_type == BAT_UNICAST && + atomic_read(&bat_priv->fragmentation) && + skb->len > neigh_node->if_incoming->net_dev->mtu) { + ret = frag_send_skb(skb, bat_priv, + neigh_node->if_incoming, neigh_node->addr); + goto out; + } + + if (unicast_packet->header.packet_type == BAT_UNICAST_FRAG && + frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) { + + ret = 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 unicast_packet *)skb->data; + } + + /* decrement ttl */ + unicast_packet->header.ttl--; + + /* route it */ + send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr); + ret = NET_RX_SUCCESS; + +out: + if (neigh_node) + neigh_node_free_ref(neigh_node); + if (orig_node) + orig_node_free_ref(orig_node); + return ret; +} + +static int check_unicast_ttvn(struct bat_priv *bat_priv, + struct sk_buff *skb) { + uint8_t curr_ttvn; + struct orig_node *orig_node; + struct ethhdr *ethhdr; + struct hard_iface *primary_if; + struct unicast_packet *unicast_packet; + bool tt_poss_change; + + /* I could need to modify it */ + if (skb_cow(skb, sizeof(struct unicast_packet)) < 0) + return 0; + + unicast_packet = (struct unicast_packet *)skb->data; + + if (is_my_mac(unicast_packet->dest)) { + tt_poss_change = bat_priv->tt_poss_change; + curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn); + } else { + orig_node = 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; + orig_node_free_ref(orig_node); + } + + /* Check whether I have to reroute the packet */ + if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) { + /* Linearize the skb before accessing it */ + if (skb_linearize(skb) < 0) + return 0; + + ethhdr = (struct ethhdr *)(skb->data + + sizeof(struct unicast_packet)); + orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest); + + if (!orig_node) { + if (!is_my_client(bat_priv, ethhdr->h_dest)) + return 0; + primary_if = primary_if_get_selected(bat_priv); + if (!primary_if) + return 0; + memcpy(unicast_packet->dest, + primary_if->net_dev->dev_addr, ETH_ALEN); + 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); + orig_node_free_ref(orig_node); + } + + bat_dbg(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 recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct unicast_packet *unicast_packet; + int hdr_size = sizeof(*unicast_packet); + + if (check_unicast_packet(skb, hdr_size) < 0) + return NET_RX_DROP; + + if (!check_unicast_ttvn(bat_priv, skb)) + return NET_RX_DROP; + + unicast_packet = (struct unicast_packet *)skb->data; + + /* packet for me */ + if (is_my_mac(unicast_packet->dest)) { + interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size); + return NET_RX_SUCCESS; + } + + return route_unicast_packet(skb, recv_if); +} + +int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct unicast_frag_packet *unicast_packet; + int hdr_size = sizeof(*unicast_packet); + struct sk_buff *new_skb = NULL; + int ret; + + if (check_unicast_packet(skb, hdr_size) < 0) + return NET_RX_DROP; + + if (!check_unicast_ttvn(bat_priv, skb)) + return NET_RX_DROP; + + unicast_packet = (struct unicast_frag_packet *)skb->data; + + /* packet for me */ + if (is_my_mac(unicast_packet->dest)) { + + ret = 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; + + interface_rx(recv_if->soft_iface, new_skb, recv_if, + sizeof(struct unicast_packet)); + return NET_RX_SUCCESS; + } + + return route_unicast_packet(skb, recv_if); +} + + +int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); + struct orig_node *orig_node = NULL; + struct 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 (is_my_mac(ethhdr->h_source)) + goto out; + + bcast_packet = (struct bcast_packet *)skb->data; + + /* ignore broadcasts originated by myself */ + if (is_my_mac(bcast_packet->orig)) + goto out; + + if (bcast_packet->header.ttl < 2) + goto out; + + orig_node = 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 (get_bit_status(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 (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 (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); + + /* rebroadcast packet */ + add_bcast_packet_to_list(bat_priv, skb, 1); + + /* broadcast for me */ + interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size); + ret = NET_RX_SUCCESS; + goto out; + +spin_unlock: + spin_unlock_bh(&orig_node->bcast_seqno_lock); +out: + if (orig_node) + orig_node_free_ref(orig_node); + return ret; +} + +int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if) +{ + struct vis_packet *vis_packet; + struct ethhdr *ethhdr; + struct bat_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 vis_packet *)skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* not for me */ + if (!is_my_mac(ethhdr->h_dest)) + return NET_RX_DROP; + + /* ignore own packets */ + if (is_my_mac(vis_packet->vis_orig)) + return NET_RX_DROP; + + if (is_my_mac(vis_packet->sender_orig)) + return NET_RX_DROP; + + switch (vis_packet->vis_type) { + case VIS_TYPE_SERVER_SYNC: + receive_server_sync_packet(bat_priv, vis_packet, + skb_headlen(skb)); + break; + + case VIS_TYPE_CLIENT_UPDATE: + 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; +} |