diff options
Diffstat (limited to 'net/batman-adv/bat_iv_ogm.c')
| -rw-r--r-- | net/batman-adv/bat_iv_ogm.c | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c new file mode 100644 index 000000000000..6fa2d465b6cd --- /dev/null +++ b/net/batman-adv/bat_iv_ogm.c @@ -0,0 +1,639 @@ +/* + * 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" + +/* 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)); +} |