/* * Copyright (C) 2007-2011 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 "bat_ogm.h" #include "translation-table.h" #include "ring_buffer.h" #include "originator.h" #include "routing.h" #include "gateway_common.h" #include "gateway_client.h" #include "hard-interface.h" #include "send.h" void bat_ogm_init(struct hard_iface *hard_iface) { struct batman_ogm_packet *batman_ogm_packet; hard_iface->packet_len = BATMAN_OGM_LEN; hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC); batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff; batman_ogm_packet->packet_type = BAT_OGM; batman_ogm_packet->version = COMPAT_VERSION; batman_ogm_packet->flags = NO_FLAGS; batman_ogm_packet->ttl = 2; batman_ogm_packet->tq = TQ_MAX_VALUE; batman_ogm_packet->tt_num_changes = 0; batman_ogm_packet->ttvn = 0; } void bat_ogm_init_primary(struct hard_iface *hard_iface) { struct batman_ogm_packet *batman_ogm_packet; batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff; batman_ogm_packet->flags = PRIMARIES_FIRST_HOP; batman_ogm_packet->ttl = TTL; } void bat_ogm_update_mac(struct hard_iface *hard_iface) { struct batman_ogm_packet *batman_ogm_packet; batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff; memcpy(batman_ogm_packet->orig, hard_iface->net_dev->dev_addr, ETH_ALEN); memcpy(batman_ogm_packet->prev_sender, hard_iface->net_dev->dev_addr, ETH_ALEN); } /* is there another aggregated packet here? */ static int bat_ogm_aggr_packet(int buff_pos, int packet_len, int tt_num_changes) { int next_buff_pos = buff_pos + BATMAN_OGM_LEN + tt_len(tt_num_changes); return (next_buff_pos <= packet_len) && (next_buff_pos <= MAX_AGGREGATION_BYTES); } static void bat_ogm_orig_update(struct bat_priv *bat_priv, struct orig_node *orig_node, const struct ethhdr *ethhdr, const struct batman_ogm_packet *batman_ogm_packet, struct hard_iface *if_incoming, const unsigned char *tt_buff, int is_duplicate) { struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL; struct neigh_node *router = NULL; struct orig_node *orig_node_tmp; struct hlist_node *node; uint8_t bcast_own_sum_orig, bcast_own_sum_neigh; bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): " "Searching and updating originator entry of received packet\n"); rcu_read_lock(); hlist_for_each_entry_rcu(tmp_neigh_node, node, &orig_node->neigh_list, list) { if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) && (tmp_neigh_node->if_incoming == if_incoming) && atomic_inc_not_zero(&tmp_neigh_node->refcount)) { if (neigh_node) neigh_node_free_ref(neigh_node); neigh_node = tmp_neigh_node; continue; } if (is_duplicate) continue; spin_lock_bh(&tmp_neigh_node->tq_lock); ring_buffer_set(tmp_neigh_node->tq_recv, &tmp_neigh_node->tq_index, 0); tmp_neigh_node->tq_avg = ring_buffer_avg(tmp_neigh_node->tq_recv); spin_unlock_bh(&tmp_neigh_node->tq_lock); } if (!neigh_node) { struct orig_node *orig_tmp; orig_tmp = get_orig_node(bat_priv, ethhdr->h_source); if (!orig_tmp) goto unlock; neigh_node = create_neighbor(orig_node, orig_tmp, ethhdr->h_source, if_incoming); orig_node_free_ref(orig_tmp); if (!neigh_node) goto unlock; } else bat_dbg(DBG_BATMAN, bat_priv, "Updating existing last-hop neighbor of originator\n"); rcu_read_unlock(); orig_node->flags = batman_ogm_packet->flags; neigh_node->last_valid = jiffies; spin_lock_bh(&neigh_node->tq_lock); ring_buffer_set(neigh_node->tq_recv, &neigh_node->tq_index, batman_ogm_packet->tq); neigh_node->tq_avg = ring_buffer_avg(neigh_node->tq_recv); spin_unlock_bh(&neigh_node->tq_lock); if (!is_duplicate) { orig_node->last_ttl = batman_ogm_packet->ttl; neigh_node->last_ttl = batman_ogm_packet->ttl; } bonding_candidate_add(orig_node, neigh_node); /* if this neighbor already is our next hop there is nothing * to change */ router = orig_node_get_router(orig_node); if (router == neigh_node) goto update_tt; /* if this neighbor does not offer a better TQ we won't consider it */ if (router && (router->tq_avg > neigh_node->tq_avg)) goto update_tt; /* if the TQ is the same and the link not more symmetric we * won't consider it either */ if (router && (neigh_node->tq_avg == router->tq_avg)) { orig_node_tmp = router->orig_node; spin_lock_bh(&orig_node_tmp->ogm_cnt_lock); bcast_own_sum_orig = orig_node_tmp->bcast_own_sum[if_incoming->if_num]; spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock); orig_node_tmp = neigh_node->orig_node; spin_lock_bh(&orig_node_tmp->ogm_cnt_lock); bcast_own_sum_neigh = orig_node_tmp->bcast_own_sum[if_incoming->if_num]; spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock); if (bcast_own_sum_orig >= bcast_own_sum_neigh) goto update_tt; } update_route(bat_priv, orig_node, neigh_node); update_tt: /* I have to check for transtable changes only if the OGM has been * sent through a primary interface */ if (((batman_ogm_packet->orig != ethhdr->h_source) && (batman_ogm_packet->ttl > 2)) || (batman_ogm_packet->flags & PRIMARIES_FIRST_HOP)) tt_update_orig(bat_priv, orig_node, tt_buff, batman_ogm_packet->tt_num_changes, batman_ogm_packet->ttvn, batman_ogm_packet->tt_crc); if (orig_node->gw_flags != batman_ogm_packet->gw_flags) gw_node_update(bat_priv, orig_node, batman_ogm_packet->gw_flags); orig_node->gw_flags = batman_ogm_packet->gw_flags; /* restart gateway selection if fast or late switching was enabled */ if ((orig_node->gw_flags) && (atomic_read(&bat_priv->gw_mode) == GW_MODE_CLIENT) && (atomic_read(&bat_priv->gw_sel_class) > 2)) gw_check_election(bat_priv, orig_node); goto out; unlock: rcu_read_unlock(); out: if (neigh_node) neigh_node_free_ref(neigh_node); if (router) neigh_node_free_ref(router); } static int bat_ogm_calc_tq(struct orig_node *orig_node, struct orig_node *orig_neigh_node, struct batman_ogm_packet *batman_ogm_packet, struct hard_iface *if_incoming) { struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface); struct neigh_node *neigh_node = NULL, *tmp_neigh_node; struct hlist_node *node; uint8_t total_count; uint8_t orig_eq_count, neigh_rq_count, tq_own; int tq_asym_penalty, ret = 0; /* find corresponding one hop neighbor */ rcu_read_lock(); hlist_for_each_entry_rcu(tmp_neigh_node, node, &orig_neigh_node->neigh_list, list) { if (!compare_eth(tmp_neigh_node->addr, orig_neigh_node->orig)) continue; if (tmp_neigh_node->if_incoming != if_incoming) continue; if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) continue; neigh_node = tmp_neigh_node; break; } rcu_read_unlock(); if (!neigh_node) neigh_node = create_neighbor(orig_neigh_node, orig_neigh_node, orig_neigh_node->orig, if_incoming); if (!neigh_node) goto out; /* if orig_node is direct neighbor update neigh_node last_valid */ if (orig_node == orig_neigh_node) neigh_node->last_valid = jiffies; orig_node->last_valid = jiffies; /* find packet count of corresponding one hop neighbor */ spin_lock_bh(&orig_node->ogm_cnt_lock); orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num]; neigh_rq_count = neigh_node->real_packet_count; spin_unlock_bh(&orig_node->ogm_cnt_lock); /* pay attention to not get a value bigger than 100 % */ total_count = (orig_eq_count > neigh_rq_count ? neigh_rq_count : orig_eq_count); /* if we have too few packets (too less data) we set tq_own to zero */ /* if we receive too few packets it is not considered bidirectional */ if ((total_count < TQ_LOCAL_BIDRECT_SEND_MINIMUM) || (neigh_rq_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM)) tq_own = 0; else /* neigh_node->real_packet_count is never zero as we * only purge old information when getting new * information */ tq_own = (TQ_MAX_VALUE * total_count) / neigh_rq_count; /* * 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does * affect the nearly-symmetric links only a little, but * punishes asymmetric links more. This will give a value * between 0 and TQ_MAX_VALUE */ tq_asym_penalty = TQ_MAX_VALUE - (TQ_MAX_VALUE * (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) * (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) * (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count)) / (TQ_LOCAL_WINDOW_SIZE * TQ_LOCAL_WINDOW_SIZE * TQ_LOCAL_WINDOW_SIZE); batman_ogm_packet->tq = ((batman_ogm_packet->tq * tq_own * tq_asym_penalty) / (TQ_MAX_VALUE * TQ_MAX_VALUE)); bat_dbg(DBG_BATMAN, bat_priv, "bidirectional: " "orig = %-15pM neigh = %-15pM => own_bcast = %2i, " "real recv = %2i, local tq: %3i, asym_penalty: %3i, " "total tq: %3i\n", orig_node->orig, orig_neigh_node->orig, total_count, neigh_rq_count, tq_own, tq_asym_penalty, batman_ogm_packet->tq); /* if link has the minimum required transmission quality * consider it bidirectional */ if (batman_ogm_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT) ret = 1; out: if (neigh_node) neigh_node_free_ref(neigh_node); return ret; } /* processes a batman packet for all interfaces, adjusts the sequence number and * finds out whether it is a duplicate. * returns: * 1 the packet is a duplicate * 0 the packet has not yet been received * -1 the packet is old and has been received while the seqno window * was protected. Caller should drop it. */ static int bat_ogm_update_seqnos(const struct ethhdr *ethhdr, const struct batman_ogm_packet *batman_ogm_packet, const struct hard_iface *if_incoming) { struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface); struct orig_node *orig_node; struct neigh_node *tmp_neigh_node; struct hlist_node *node; int is_duplicate = 0; int32_t seq_diff; int need_update = 0; int set_mark, ret = -1; orig_node = get_orig_node(bat_priv, batman_ogm_packet->orig); if (!orig_node) return 0; spin_lock_bh(&orig_node->ogm_cnt_lock); seq_diff = batman_ogm_packet->seqno - orig_node->last_real_seqno; /* signalize caller that the packet is to be dropped. */ if (window_protected(bat_priv, seq_diff, &orig_node->batman_seqno_reset)) goto out; rcu_read_lock(); hlist_for_each_entry_rcu(tmp_neigh_node, node, &orig_node->neigh_list, list) { is_duplicate |= get_bit_status(tmp_neigh_node->real_bits, orig_node->last_real_seqno, batman_ogm_packet->seqno); if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) && (tmp_neigh_node->if_incoming == if_incoming)) set_mark = 1; else set_mark = 0; /* if the window moved, set the update flag. */ need_update |= bit_get_packet(bat_priv, tmp_neigh_node->real_bits, seq_diff, set_mark); tmp_neigh_node->real_packet_count = bit_packet_count(tmp_neigh_node->real_bits); } rcu_read_unlock(); if (need_update) { bat_dbg(DBG_BATMAN, bat_priv, "updating last_seqno: old %d, new %d\n", orig_node->last_real_seqno, batman_ogm_packet->seqno); orig_node->last_real_seqno = batman_ogm_packet->seqno; } ret = is_duplicate; out: spin_unlock_bh(&orig_node->ogm_cnt_lock); orig_node_free_ref(orig_node); return ret; } static void bat_ogm_process(const struct ethhdr *ethhdr, struct batman_ogm_packet *batman_ogm_packet, const unsigned char *tt_buff, struct hard_iface *if_incoming) { struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface); struct hard_iface *hard_iface; struct orig_node *orig_neigh_node, *orig_node; struct neigh_node *router = NULL, *router_router = NULL; struct neigh_node *orig_neigh_router = NULL; int has_directlink_flag; int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0; int is_broadcast = 0, is_bidirectional, is_single_hop_neigh; int is_duplicate; uint32_t if_incoming_seqno; /* Silently drop when the batman packet is actually not a * correct packet. * * This might happen if a packet is padded (e.g. Ethernet has a * minimum frame length of 64 byte) and the aggregation interprets * it as an additional length. * * TODO: A more sane solution would be to have a bit in the * batman_ogm_packet to detect whether the packet is the last * packet in an aggregation. Here we expect that the padding * is always zero (or not 0x01) */ if (batman_ogm_packet->packet_type != BAT_OGM) return; /* could be changed by schedule_own_packet() */ if_incoming_seqno = atomic_read(&if_incoming->seqno); has_directlink_flag = (batman_ogm_packet->flags & DIRECTLINK ? 1 : 0); is_single_hop_neigh = (compare_eth(ethhdr->h_source, batman_ogm_packet->orig) ? 1 : 0); bat_dbg(DBG_BATMAN, bat_priv, "Received BATMAN packet via NB: %pM, IF: %s [%pM] " "(from OG: %pM, via prev OG: %pM, seqno %d, ttvn %u, " "crc %u, changes %u, td %d, TTL %d, V %d, IDF %d)\n", ethhdr->h_source, if_incoming->net_dev->name, if_incoming->net_dev->dev_addr, batman_ogm_packet->orig, batman_ogm_packet->prev_sender, batman_ogm_packet->seqno, batman_ogm_packet->ttvn, batman_ogm_packet->tt_crc, batman_ogm_packet->tt_num_changes, batman_ogm_packet->tq, batman_ogm_packet->ttl, batman_ogm_packet->version, has_directlink_flag); rcu_read_lock(); list_for_each_entry_rcu(hard_iface, &hardif_list, list) { if (hard_iface->if_status != IF_ACTIVE) continue; if (hard_iface->soft_iface != if_incoming->soft_iface) continue; if (compare_eth(ethhdr->h_source, hard_iface->net_dev->dev_addr)) is_my_addr = 1; if (compare_eth(batman_ogm_packet->orig, hard_iface->net_dev->dev_addr)) is_my_orig = 1; if (compare_eth(batman_ogm_packet->prev_sender, hard_iface->net_dev->dev_addr)) is_my_oldorig = 1; if (is_broadcast_ether_addr(ethhdr->h_source)) is_broadcast = 1; } rcu_read_unlock(); if (batman_ogm_packet->version != COMPAT_VERSION) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: incompatible batman version (%i)\n", batman_ogm_packet->version); return; } if (is_my_addr) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: received my own broadcast (sender: %pM" ")\n", ethhdr->h_source); return; } if (is_broadcast) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: " "ignoring all packets with broadcast source addr (sender: %pM" ")\n", ethhdr->h_source); return; } if (is_my_orig) { unsigned long *word; int offset; orig_neigh_node = get_orig_node(bat_priv, ethhdr->h_source); if (!orig_neigh_node) return; /* neighbor has to indicate direct link and it has to * come via the corresponding interface */ /* save packet seqno for bidirectional check */ if (has_directlink_flag && compare_eth(if_incoming->net_dev->dev_addr, batman_ogm_packet->orig)) { offset = if_incoming->if_num * NUM_WORDS; spin_lock_bh(&orig_neigh_node->ogm_cnt_lock); word = &(orig_neigh_node->bcast_own[offset]); bit_mark(word, if_incoming_seqno - batman_ogm_packet->seqno - 2); orig_neigh_node->bcast_own_sum[if_incoming->if_num] = bit_packet_count(word); spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock); } bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: " "originator packet from myself (via neighbor)\n"); orig_node_free_ref(orig_neigh_node); return; } if (is_my_oldorig) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: ignoring all rebroadcast echos (sender: " "%pM)\n", ethhdr->h_source); return; } orig_node = get_orig_node(bat_priv, batman_ogm_packet->orig); if (!orig_node) return; is_duplicate = bat_ogm_update_seqnos(ethhdr, batman_ogm_packet, if_incoming); if (is_duplicate == -1) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: packet within seqno protection time " "(sender: %pM)\n", ethhdr->h_source); goto out; } if (batman_ogm_packet->tq == 0) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: originator packet with tq equal 0\n"); goto out; } router = orig_node_get_router(orig_node); if (router) router_router = orig_node_get_router(router->orig_node); /* avoid temporary routing loops */ if (router && router_router && (compare_eth(router->addr, batman_ogm_packet->prev_sender)) && !(compare_eth(batman_ogm_packet->orig, batman_ogm_packet->prev_sender)) && (compare_eth(router->addr, router_router->addr))) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: ignoring all rebroadcast packets that " "may make me loop (sender: %pM)\n", ethhdr->h_source); goto out; } /* if sender is a direct neighbor the sender mac equals * originator mac */ orig_neigh_node = (is_single_hop_neigh ? orig_node : get_orig_node(bat_priv, ethhdr->h_source)); if (!orig_neigh_node) goto out; orig_neigh_router = orig_node_get_router(orig_neigh_node); /* drop packet if sender is not a direct neighbor and if we * don't route towards it */ if (!is_single_hop_neigh && (!orig_neigh_router)) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: OGM via unknown neighbor!\n"); goto out_neigh; } is_bidirectional = bat_ogm_calc_tq(orig_node, orig_neigh_node, batman_ogm_packet, if_incoming); bonding_save_primary(orig_node, orig_neigh_node, batman_ogm_packet); /* update ranking if it is not a duplicate or has the same * seqno and similar ttl as the non-duplicate */ if (is_bidirectional && (!is_duplicate || ((orig_node->last_real_seqno == batman_ogm_packet->seqno) && (orig_node->last_ttl - 3 <= batman_ogm_packet->ttl)))) bat_ogm_orig_update(bat_priv, orig_node, ethhdr, batman_ogm_packet, if_incoming, tt_buff, is_duplicate); /* is single hop (direct) neighbor */ if (is_single_hop_neigh) { /* mark direct link on incoming interface */ schedule_forward_packet(orig_node, ethhdr, batman_ogm_packet, 1, if_incoming); bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: " "rebroadcast neighbor packet with direct link flag\n"); goto out_neigh; } /* multihop originator */ if (!is_bidirectional) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: not received via bidirectional link\n"); goto out_neigh; } if (is_duplicate) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: duplicate packet received\n"); goto out_neigh; } bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: rebroadcast originator packet\n"); schedule_forward_packet(orig_node, ethhdr, batman_ogm_packet, 0, if_incoming); out_neigh: if ((orig_neigh_node) && (!is_single_hop_neigh)) orig_node_free_ref(orig_neigh_node); out: if (router) neigh_node_free_ref(router); if (router_router) neigh_node_free_ref(router_router); if (orig_neigh_router) neigh_node_free_ref(orig_neigh_router); orig_node_free_ref(orig_node); } void bat_ogm_receive(const struct ethhdr *ethhdr, unsigned char *packet_buff, int packet_len, struct hard_iface *if_incoming) { struct batman_ogm_packet *batman_ogm_packet; int buff_pos = 0; unsigned char *tt_buff; batman_ogm_packet = (struct batman_ogm_packet *)packet_buff; /* unpack the aggregated packets and process them one by one */ do { /* network to host order for our 32bit seqno and the orig_interval */ batman_ogm_packet->seqno = ntohl(batman_ogm_packet->seqno); batman_ogm_packet->tt_crc = ntohs(batman_ogm_packet->tt_crc); tt_buff = packet_buff + buff_pos + BATMAN_OGM_LEN; bat_ogm_process(ethhdr, batman_ogm_packet, tt_buff, if_incoming); buff_pos += BATMAN_OGM_LEN + tt_len(batman_ogm_packet->tt_num_changes); batman_ogm_packet = (struct batman_ogm_packet *) (packet_buff + buff_pos); } while (bat_ogm_aggr_packet(buff_pos, packet_len, batman_ogm_packet->tt_num_changes)); }