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0538f75991
some of the fields in struct batadv_neigh_node are strictly related to the B.A.T.M.A.N. IV algorithm. In order to make the struct usable by any routing algorithm it has to be split and made more generic Signed-off-by: Antonio Quartulli <antonio@open-mesh.com> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
822 lines
21 KiB
C
822 lines
21 KiB
C
/* Copyright (C) 2009-2013 B.A.T.M.A.N. contributors:
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*
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* Marek Lindner
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA
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*/
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#include "main.h"
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#include "sysfs.h"
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#include "gateway_client.h"
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#include "gateway_common.h"
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#include "hard-interface.h"
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#include "originator.h"
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#include "translation-table.h"
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#include "routing.h"
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/udp.h>
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#include <linux/if_vlan.h>
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/* This is the offset of the options field in a dhcp packet starting at
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* the beginning of the dhcp header
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*/
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#define BATADV_DHCP_OPTIONS_OFFSET 240
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#define BATADV_DHCP_REQUEST 3
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static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
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{
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if (atomic_dec_and_test(&gw_node->refcount))
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kfree_rcu(gw_node, rcu);
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}
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static struct batadv_gw_node *
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batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
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{
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struct batadv_gw_node *gw_node;
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rcu_read_lock();
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gw_node = rcu_dereference(bat_priv->gw.curr_gw);
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if (!gw_node)
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goto out;
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if (!atomic_inc_not_zero(&gw_node->refcount))
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gw_node = NULL;
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out:
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rcu_read_unlock();
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return gw_node;
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}
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struct batadv_orig_node *
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batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
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{
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struct batadv_gw_node *gw_node;
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struct batadv_orig_node *orig_node = NULL;
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gw_node = batadv_gw_get_selected_gw_node(bat_priv);
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if (!gw_node)
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goto out;
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rcu_read_lock();
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orig_node = gw_node->orig_node;
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if (!orig_node)
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goto unlock;
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if (!atomic_inc_not_zero(&orig_node->refcount))
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orig_node = NULL;
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unlock:
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rcu_read_unlock();
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out:
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if (gw_node)
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batadv_gw_node_free_ref(gw_node);
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return orig_node;
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}
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static void batadv_gw_select(struct batadv_priv *bat_priv,
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struct batadv_gw_node *new_gw_node)
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{
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struct batadv_gw_node *curr_gw_node;
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spin_lock_bh(&bat_priv->gw.list_lock);
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if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
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new_gw_node = NULL;
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curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
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rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
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if (curr_gw_node)
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batadv_gw_node_free_ref(curr_gw_node);
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spin_unlock_bh(&bat_priv->gw.list_lock);
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}
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void batadv_gw_deselect(struct batadv_priv *bat_priv)
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{
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atomic_set(&bat_priv->gw.reselect, 1);
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}
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static struct batadv_gw_node *
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batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
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{
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struct batadv_neigh_node *router;
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struct batadv_gw_node *gw_node, *curr_gw = NULL;
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uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
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uint32_t gw_divisor;
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uint8_t max_tq = 0;
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uint8_t tq_avg;
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struct batadv_orig_node *orig_node;
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gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
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gw_divisor *= 64;
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rcu_read_lock();
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hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
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if (gw_node->deleted)
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continue;
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orig_node = gw_node->orig_node;
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router = batadv_orig_node_get_router(orig_node);
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if (!router)
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continue;
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if (!atomic_inc_not_zero(&gw_node->refcount))
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goto next;
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tq_avg = router->bat_iv.tq_avg;
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switch (atomic_read(&bat_priv->gw_sel_class)) {
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case 1: /* fast connection */
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tmp_gw_factor = tq_avg * tq_avg;
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tmp_gw_factor *= gw_node->bandwidth_down;
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tmp_gw_factor *= 100 * 100;
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tmp_gw_factor /= gw_divisor;
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if ((tmp_gw_factor > max_gw_factor) ||
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((tmp_gw_factor == max_gw_factor) &&
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(tq_avg > max_tq))) {
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if (curr_gw)
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batadv_gw_node_free_ref(curr_gw);
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curr_gw = gw_node;
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atomic_inc(&curr_gw->refcount);
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}
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break;
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default: /* 2: stable connection (use best statistic)
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* 3: fast-switch (use best statistic but change as
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* soon as a better gateway appears)
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* XX: late-switch (use best statistic but change as
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* soon as a better gateway appears which has
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* $routing_class more tq points)
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*/
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if (tq_avg > max_tq) {
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if (curr_gw)
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batadv_gw_node_free_ref(curr_gw);
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curr_gw = gw_node;
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atomic_inc(&curr_gw->refcount);
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}
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break;
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}
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if (tq_avg > max_tq)
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max_tq = tq_avg;
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if (tmp_gw_factor > max_gw_factor)
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max_gw_factor = tmp_gw_factor;
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batadv_gw_node_free_ref(gw_node);
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next:
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batadv_neigh_node_free_ref(router);
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}
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rcu_read_unlock();
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return curr_gw;
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}
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/**
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* batadv_gw_check_client_stop - check if client mode has been switched off
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* @bat_priv: the bat priv with all the soft interface information
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*
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* This function assumes the caller has checked that the gw state *is actually
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* changing*. This function is not supposed to be called when there is no state
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* change.
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*/
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void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
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{
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struct batadv_gw_node *curr_gw;
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if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
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return;
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curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
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if (!curr_gw)
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return;
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/* if batman-adv is switching the gw client mode off and a gateway was
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* already selected, send a DEL uevent
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*/
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batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
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batadv_gw_node_free_ref(curr_gw);
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}
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void batadv_gw_election(struct batadv_priv *bat_priv)
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{
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struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
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struct batadv_neigh_node *router = NULL;
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char gw_addr[18] = { '\0' };
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if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
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goto out;
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curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
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if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
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goto out;
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next_gw = batadv_gw_get_best_gw_node(bat_priv);
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if (curr_gw == next_gw)
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goto out;
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if (next_gw) {
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sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
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router = batadv_orig_node_get_router(next_gw->orig_node);
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if (!router) {
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batadv_gw_deselect(bat_priv);
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goto out;
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}
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}
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if ((curr_gw) && (!next_gw)) {
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Removing selected gateway - no gateway in range\n");
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batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
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NULL);
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} else if ((!curr_gw) && (next_gw)) {
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
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next_gw->orig_node->orig,
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next_gw->bandwidth_down / 10,
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next_gw->bandwidth_down % 10,
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next_gw->bandwidth_up / 10,
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next_gw->bandwidth_up % 10, router->bat_iv.tq_avg);
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batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
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gw_addr);
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} else {
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
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next_gw->orig_node->orig,
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next_gw->bandwidth_down / 10,
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next_gw->bandwidth_down % 10,
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next_gw->bandwidth_up / 10,
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next_gw->bandwidth_up % 10, router->bat_iv.tq_avg);
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batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
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gw_addr);
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}
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batadv_gw_select(bat_priv, next_gw);
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out:
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if (curr_gw)
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batadv_gw_node_free_ref(curr_gw);
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if (next_gw)
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batadv_gw_node_free_ref(next_gw);
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if (router)
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batadv_neigh_node_free_ref(router);
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}
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void batadv_gw_check_election(struct batadv_priv *bat_priv,
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struct batadv_orig_node *orig_node)
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{
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struct batadv_orig_node *curr_gw_orig;
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struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
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uint8_t gw_tq_avg, orig_tq_avg;
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curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
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if (!curr_gw_orig)
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goto deselect;
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router_gw = batadv_orig_node_get_router(curr_gw_orig);
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if (!router_gw)
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goto deselect;
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/* this node already is the gateway */
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if (curr_gw_orig == orig_node)
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goto out;
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router_orig = batadv_orig_node_get_router(orig_node);
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if (!router_orig)
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goto out;
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gw_tq_avg = router_gw->bat_iv.tq_avg;
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orig_tq_avg = router_orig->bat_iv.tq_avg;
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/* the TQ value has to be better */
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if (orig_tq_avg < gw_tq_avg)
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goto out;
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/* if the routing class is greater than 3 the value tells us how much
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* greater the TQ value of the new gateway must be
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*/
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if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
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(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
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goto out;
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
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gw_tq_avg, orig_tq_avg);
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deselect:
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batadv_gw_deselect(bat_priv);
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out:
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if (curr_gw_orig)
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batadv_orig_node_free_ref(curr_gw_orig);
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if (router_gw)
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batadv_neigh_node_free_ref(router_gw);
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if (router_orig)
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batadv_neigh_node_free_ref(router_orig);
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return;
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}
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/**
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* batadv_gw_node_add - add gateway node to list of available gateways
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* @bat_priv: the bat priv with all the soft interface information
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* @orig_node: originator announcing gateway capabilities
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* @gateway: announced bandwidth information
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*/
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static void batadv_gw_node_add(struct batadv_priv *bat_priv,
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struct batadv_orig_node *orig_node,
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struct batadv_tvlv_gateway_data *gateway)
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{
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struct batadv_gw_node *gw_node;
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if (gateway->bandwidth_down == 0)
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return;
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gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
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if (!gw_node)
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return;
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INIT_HLIST_NODE(&gw_node->list);
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gw_node->orig_node = orig_node;
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atomic_set(&gw_node->refcount, 1);
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spin_lock_bh(&bat_priv->gw.list_lock);
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hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
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spin_unlock_bh(&bat_priv->gw.list_lock);
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
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orig_node->orig,
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ntohl(gateway->bandwidth_down) / 10,
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ntohl(gateway->bandwidth_down) % 10,
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ntohl(gateway->bandwidth_up) / 10,
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ntohl(gateway->bandwidth_up) % 10);
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}
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/**
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* batadv_gw_node_get - retrieve gateway node from list of available gateways
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* @bat_priv: the bat priv with all the soft interface information
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* @orig_node: originator announcing gateway capabilities
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*
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* Returns gateway node if found or NULL otherwise.
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*/
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static struct batadv_gw_node *
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batadv_gw_node_get(struct batadv_priv *bat_priv,
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struct batadv_orig_node *orig_node)
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{
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struct batadv_gw_node *gw_node_tmp, *gw_node = NULL;
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rcu_read_lock();
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hlist_for_each_entry_rcu(gw_node_tmp, &bat_priv->gw.list, list) {
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if (gw_node_tmp->orig_node != orig_node)
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continue;
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if (gw_node_tmp->deleted)
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continue;
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if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
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continue;
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gw_node = gw_node_tmp;
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break;
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}
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rcu_read_unlock();
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return gw_node;
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}
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/**
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* batadv_gw_node_update - update list of available gateways with changed
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* bandwidth information
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* @bat_priv: the bat priv with all the soft interface information
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* @orig_node: originator announcing gateway capabilities
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* @gateway: announced bandwidth information
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*/
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void batadv_gw_node_update(struct batadv_priv *bat_priv,
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struct batadv_orig_node *orig_node,
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struct batadv_tvlv_gateway_data *gateway)
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{
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struct batadv_gw_node *gw_node, *curr_gw = NULL;
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gw_node = batadv_gw_node_get(bat_priv, orig_node);
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if (!gw_node) {
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batadv_gw_node_add(bat_priv, orig_node, gateway);
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goto out;
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}
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if ((gw_node->bandwidth_down == ntohl(gateway->bandwidth_down)) &&
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(gw_node->bandwidth_up == ntohl(gateway->bandwidth_up)))
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goto out;
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
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orig_node->orig,
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gw_node->bandwidth_down / 10,
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gw_node->bandwidth_down % 10,
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gw_node->bandwidth_up / 10,
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gw_node->bandwidth_up % 10,
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ntohl(gateway->bandwidth_down) / 10,
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ntohl(gateway->bandwidth_down) % 10,
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ntohl(gateway->bandwidth_up) / 10,
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ntohl(gateway->bandwidth_up) % 10);
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gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
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gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
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gw_node->deleted = 0;
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if (ntohl(gateway->bandwidth_down) == 0) {
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gw_node->deleted = jiffies;
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Gateway %pM removed from gateway list\n",
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orig_node->orig);
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|
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/* Note: We don't need a NULL check here, since curr_gw never
|
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* gets dereferenced.
|
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*/
|
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curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
|
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if (gw_node == curr_gw)
|
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batadv_gw_deselect(bat_priv);
|
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}
|
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|
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out:
|
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if (curr_gw)
|
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batadv_gw_node_free_ref(curr_gw);
|
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if (gw_node)
|
|
batadv_gw_node_free_ref(gw_node);
|
|
}
|
|
|
|
void batadv_gw_node_delete(struct batadv_priv *bat_priv,
|
|
struct batadv_orig_node *orig_node)
|
|
{
|
|
struct batadv_tvlv_gateway_data gateway;
|
|
|
|
gateway.bandwidth_down = 0;
|
|
gateway.bandwidth_up = 0;
|
|
|
|
batadv_gw_node_update(bat_priv, orig_node, &gateway);
|
|
}
|
|
|
|
void batadv_gw_node_purge(struct batadv_priv *bat_priv)
|
|
{
|
|
struct batadv_gw_node *gw_node, *curr_gw;
|
|
struct hlist_node *node_tmp;
|
|
unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
|
|
int do_deselect = 0;
|
|
|
|
curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
|
|
|
|
spin_lock_bh(&bat_priv->gw.list_lock);
|
|
|
|
hlist_for_each_entry_safe(gw_node, node_tmp,
|
|
&bat_priv->gw.list, list) {
|
|
if (((!gw_node->deleted) ||
|
|
(time_before(jiffies, gw_node->deleted + timeout))) &&
|
|
atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
|
|
continue;
|
|
|
|
if (curr_gw == gw_node)
|
|
do_deselect = 1;
|
|
|
|
hlist_del_rcu(&gw_node->list);
|
|
batadv_gw_node_free_ref(gw_node);
|
|
}
|
|
|
|
spin_unlock_bh(&bat_priv->gw.list_lock);
|
|
|
|
/* gw_deselect() needs to acquire the gw_list_lock */
|
|
if (do_deselect)
|
|
batadv_gw_deselect(bat_priv);
|
|
|
|
if (curr_gw)
|
|
batadv_gw_node_free_ref(curr_gw);
|
|
}
|
|
|
|
/* fails if orig_node has no router */
|
|
static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
|
|
struct seq_file *seq,
|
|
const struct batadv_gw_node *gw_node)
|
|
{
|
|
struct batadv_gw_node *curr_gw;
|
|
struct batadv_neigh_node *router;
|
|
int ret = -1;
|
|
|
|
router = batadv_orig_node_get_router(gw_node->orig_node);
|
|
if (!router)
|
|
goto out;
|
|
|
|
curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
|
|
|
|
ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
|
|
(curr_gw == gw_node ? "=>" : " "),
|
|
gw_node->orig_node->orig,
|
|
router->bat_iv.tq_avg, router->addr,
|
|
router->if_incoming->net_dev->name,
|
|
gw_node->bandwidth_down / 10,
|
|
gw_node->bandwidth_down % 10,
|
|
gw_node->bandwidth_up / 10,
|
|
gw_node->bandwidth_up % 10);
|
|
|
|
batadv_neigh_node_free_ref(router);
|
|
if (curr_gw)
|
|
batadv_gw_node_free_ref(curr_gw);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
|
|
{
|
|
struct net_device *net_dev = (struct net_device *)seq->private;
|
|
struct batadv_priv *bat_priv = netdev_priv(net_dev);
|
|
struct batadv_hard_iface *primary_if;
|
|
struct batadv_gw_node *gw_node;
|
|
int gw_count = 0;
|
|
|
|
primary_if = batadv_seq_print_text_primary_if_get(seq);
|
|
if (!primary_if)
|
|
goto out;
|
|
|
|
seq_printf(seq,
|
|
" %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
|
|
"Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
|
|
BATADV_SOURCE_VERSION, primary_if->net_dev->name,
|
|
primary_if->net_dev->dev_addr, net_dev->name);
|
|
|
|
rcu_read_lock();
|
|
hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
|
|
if (gw_node->deleted)
|
|
continue;
|
|
|
|
/* fails if orig_node has no router */
|
|
if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
|
|
continue;
|
|
|
|
gw_count++;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (gw_count == 0)
|
|
seq_puts(seq, "No gateways in range ...\n");
|
|
|
|
out:
|
|
if (primary_if)
|
|
batadv_hardif_free_ref(primary_if);
|
|
return 0;
|
|
}
|
|
|
|
/* this call might reallocate skb data */
|
|
static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
|
|
{
|
|
int ret = false;
|
|
unsigned char *p;
|
|
int pkt_len;
|
|
|
|
if (skb_linearize(skb) < 0)
|
|
goto out;
|
|
|
|
pkt_len = skb_headlen(skb);
|
|
|
|
if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
|
|
goto out;
|
|
|
|
p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
|
|
pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
|
|
|
|
/* Access the dhcp option lists. Each entry is made up by:
|
|
* - octet 1: option type
|
|
* - octet 2: option data len (only if type != 255 and 0)
|
|
* - octet 3: option data
|
|
*/
|
|
while (*p != 255 && !ret) {
|
|
/* p now points to the first octet: option type */
|
|
if (*p == 53) {
|
|
/* type 53 is the message type option.
|
|
* Jump the len octet and go to the data octet
|
|
*/
|
|
if (pkt_len < 2)
|
|
goto out;
|
|
p += 2;
|
|
|
|
/* check if the message type is what we need */
|
|
if (*p == BATADV_DHCP_REQUEST)
|
|
ret = true;
|
|
break;
|
|
} else if (*p == 0) {
|
|
/* option type 0 (padding), just go forward */
|
|
if (pkt_len < 1)
|
|
goto out;
|
|
pkt_len--;
|
|
p++;
|
|
} else {
|
|
/* This is any other option. So we get the length... */
|
|
if (pkt_len < 1)
|
|
goto out;
|
|
pkt_len--;
|
|
p++;
|
|
|
|
/* ...and then we jump over the data */
|
|
if (pkt_len < 1 + (*p))
|
|
goto out;
|
|
pkt_len -= 1 + (*p);
|
|
p += 1 + (*p);
|
|
}
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/* this call might reallocate skb data */
|
|
bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
|
|
{
|
|
struct ethhdr *ethhdr;
|
|
struct iphdr *iphdr;
|
|
struct ipv6hdr *ipv6hdr;
|
|
struct udphdr *udphdr;
|
|
struct vlan_ethhdr *vhdr;
|
|
__be16 proto;
|
|
|
|
/* check for ethernet header */
|
|
if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
|
|
return false;
|
|
ethhdr = (struct ethhdr *)skb->data;
|
|
proto = ethhdr->h_proto;
|
|
*header_len += ETH_HLEN;
|
|
|
|
/* check for initial vlan header */
|
|
if (proto == htons(ETH_P_8021Q)) {
|
|
if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
|
|
return false;
|
|
|
|
vhdr = (struct vlan_ethhdr *)skb->data;
|
|
proto = vhdr->h_vlan_encapsulated_proto;
|
|
*header_len += VLAN_HLEN;
|
|
}
|
|
|
|
/* check for ip header */
|
|
switch (proto) {
|
|
case htons(ETH_P_IP):
|
|
if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
|
|
return false;
|
|
iphdr = (struct iphdr *)(skb->data + *header_len);
|
|
*header_len += iphdr->ihl * 4;
|
|
|
|
/* check for udp header */
|
|
if (iphdr->protocol != IPPROTO_UDP)
|
|
return false;
|
|
|
|
break;
|
|
case htons(ETH_P_IPV6):
|
|
if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
|
|
return false;
|
|
ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
|
|
*header_len += sizeof(*ipv6hdr);
|
|
|
|
/* check for udp header */
|
|
if (ipv6hdr->nexthdr != IPPROTO_UDP)
|
|
return false;
|
|
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
|
|
return false;
|
|
|
|
/* skb->data might have been reallocated by pskb_may_pull() */
|
|
ethhdr = (struct ethhdr *)skb->data;
|
|
if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
|
|
ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
|
|
|
|
udphdr = (struct udphdr *)(skb->data + *header_len);
|
|
*header_len += sizeof(*udphdr);
|
|
|
|
/* check for bootp port */
|
|
if ((proto == htons(ETH_P_IP)) &&
|
|
(udphdr->dest != htons(67)))
|
|
return false;
|
|
|
|
if ((proto == htons(ETH_P_IPV6)) &&
|
|
(udphdr->dest != htons(547)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_gw_out_of_range - check if the dhcp request destination is the best gw
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the outgoing packet
|
|
*
|
|
* Check if the skb is a DHCP request and if it is sent to the current best GW
|
|
* server. Due to topology changes it may be the case that the GW server
|
|
* previously selected is not the best one anymore.
|
|
*
|
|
* Returns true if the packet destination is unicast and it is not the best gw,
|
|
* false otherwise.
|
|
*
|
|
* This call might reallocate skb data.
|
|
*/
|
|
bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
|
|
struct batadv_orig_node *orig_dst_node = NULL;
|
|
struct batadv_gw_node *gw_node = NULL, *curr_gw = NULL;
|
|
struct ethhdr *ethhdr;
|
|
bool ret, out_of_range = false;
|
|
unsigned int header_len = 0;
|
|
uint8_t curr_tq_avg;
|
|
unsigned short vid;
|
|
|
|
vid = batadv_get_vid(skb, 0);
|
|
|
|
ret = batadv_gw_is_dhcp_target(skb, &header_len);
|
|
if (!ret)
|
|
goto out;
|
|
|
|
ethhdr = (struct ethhdr *)skb->data;
|
|
orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
|
|
ethhdr->h_dest, vid);
|
|
if (!orig_dst_node)
|
|
goto out;
|
|
|
|
gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
|
|
if (!gw_node->bandwidth_down == 0)
|
|
goto out;
|
|
|
|
ret = batadv_is_type_dhcprequest(skb, header_len);
|
|
if (!ret)
|
|
goto out;
|
|
|
|
switch (atomic_read(&bat_priv->gw_mode)) {
|
|
case BATADV_GW_MODE_SERVER:
|
|
/* If we are a GW then we are our best GW. We can artificially
|
|
* set the tq towards ourself as the maximum value
|
|
*/
|
|
curr_tq_avg = BATADV_TQ_MAX_VALUE;
|
|
break;
|
|
case BATADV_GW_MODE_CLIENT:
|
|
curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
|
|
if (!curr_gw)
|
|
goto out;
|
|
|
|
/* packet is going to our gateway */
|
|
if (curr_gw->orig_node == orig_dst_node)
|
|
goto out;
|
|
|
|
/* If the dhcp packet has been sent to a different gw,
|
|
* we have to evaluate whether the old gw is still
|
|
* reliable enough
|
|
*/
|
|
neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
|
|
NULL);
|
|
if (!neigh_curr)
|
|
goto out;
|
|
|
|
curr_tq_avg = neigh_curr->bat_iv.tq_avg;
|
|
break;
|
|
case BATADV_GW_MODE_OFF:
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
|
|
if (!neigh_old)
|
|
goto out;
|
|
|
|
if (curr_tq_avg - neigh_old->bat_iv.tq_avg > BATADV_GW_THRESHOLD)
|
|
out_of_range = true;
|
|
|
|
out:
|
|
if (orig_dst_node)
|
|
batadv_orig_node_free_ref(orig_dst_node);
|
|
if (curr_gw)
|
|
batadv_gw_node_free_ref(curr_gw);
|
|
if (gw_node)
|
|
batadv_gw_node_free_ref(gw_node);
|
|
if (neigh_old)
|
|
batadv_neigh_node_free_ref(neigh_old);
|
|
if (neigh_curr)
|
|
batadv_neigh_node_free_ref(neigh_curr);
|
|
return out_of_range;
|
|
}
|