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768 lines
21 KiB
768 lines
21 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Copyright (C) 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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#include "gateway_client.h" |
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#include "main.h" |
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#include <linux/atomic.h> |
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#include <linux/byteorder/generic.h> |
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#include <linux/errno.h> |
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#include <linux/etherdevice.h> |
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#include <linux/gfp.h> |
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#include <linux/if_ether.h> |
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#include <linux/if_vlan.h> |
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#include <linux/in.h> |
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#include <linux/ip.h> |
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#include <linux/ipv6.h> |
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#include <linux/kernel.h> |
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#include <linux/kref.h> |
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#include <linux/list.h> |
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#include <linux/lockdep.h> |
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#include <linux/netdevice.h> |
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#include <linux/netlink.h> |
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#include <linux/rculist.h> |
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#include <linux/rcupdate.h> |
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#include <linux/skbuff.h> |
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <linux/stddef.h> |
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#include <linux/udp.h> |
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#include <net/sock.h> |
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#include <uapi/linux/batadv_packet.h> |
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#include <uapi/linux/batman_adv.h> |
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#include "hard-interface.h" |
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#include "log.h" |
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#include "netlink.h" |
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#include "originator.h" |
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#include "routing.h" |
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#include "soft-interface.h" |
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#include "translation-table.h" |
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/* These are the offsets of the "hw type" and "hw address length" in the dhcp |
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* packet starting at the beginning of the dhcp header |
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*/ |
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#define BATADV_DHCP_HTYPE_OFFSET 1 |
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#define BATADV_DHCP_HLEN_OFFSET 2 |
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/* Value of htype representing Ethernet */ |
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#define BATADV_DHCP_HTYPE_ETHERNET 0x01 |
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/* This is the offset of the "chaddr" field in the dhcp packet starting at the |
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* beginning of the dhcp header |
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*/ |
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#define BATADV_DHCP_CHADDR_OFFSET 28 |
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|
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/** |
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* batadv_gw_node_release() - release gw_node from lists and queue for free |
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* after rcu grace period |
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* @ref: kref pointer of the gw_node |
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*/ |
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void batadv_gw_node_release(struct kref *ref) |
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{ |
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struct batadv_gw_node *gw_node; |
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gw_node = container_of(ref, struct batadv_gw_node, refcount); |
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batadv_orig_node_put(gw_node->orig_node); |
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kfree_rcu(gw_node, rcu); |
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} |
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/** |
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* batadv_gw_get_selected_gw_node() - Get currently selected gateway |
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* @bat_priv: the bat priv with all the soft interface information |
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* |
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* Return: selected gateway (with increased refcnt), NULL on errors |
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*/ |
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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 (!kref_get_unless_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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/** |
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* batadv_gw_get_selected_orig() - Get originator of currently selected gateway |
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* @bat_priv: the bat priv with all the soft interface information |
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* |
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* Return: orig_node of selected gateway (with increased refcnt), NULL on errors |
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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 (!kref_get_unless_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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batadv_gw_node_put(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) |
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kref_get(&new_gw_node->refcount); |
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curr_gw_node = rcu_replace_pointer(bat_priv->gw.curr_gw, new_gw_node, |
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true); |
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batadv_gw_node_put(curr_gw_node); |
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spin_unlock_bh(&bat_priv->gw.list_lock); |
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} |
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/** |
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* batadv_gw_reselect() - force a gateway reselection |
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* @bat_priv: the bat priv with all the soft interface information |
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* |
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* Set a flag to remind the GW component to perform a new gateway reselection. |
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* However this function does not ensure that the current gateway is going to be |
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* deselected. The reselection mechanism may elect the same gateway once again. |
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* |
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* This means that invoking batadv_gw_reselect() does not guarantee a gateway |
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* change and therefore a uevent is not necessarily expected. |
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*/ |
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void batadv_gw_reselect(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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/** |
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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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/* deselect the current gateway so that next time that client mode is |
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* enabled a proper GW_ADD event can be sent |
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*/ |
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batadv_gw_select(bat_priv, NULL); |
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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_put(curr_gw); |
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} |
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/** |
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* batadv_gw_election() - Elect the best gateway |
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* @bat_priv: the bat priv with all the soft interface information |
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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; |
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struct batadv_gw_node *next_gw = NULL; |
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struct batadv_neigh_node *router = NULL; |
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struct batadv_neigh_ifinfo *router_ifinfo = 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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if (!bat_priv->algo_ops->gw.get_best_gw_node) |
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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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/* if gw.reselect is set to 1 it means that a previous call to |
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* gw.is_eligible() said that we have a new best GW, therefore it can |
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* now be picked from the list and selected |
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*/ |
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next_gw = bat_priv->algo_ops->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_router_get(next_gw->orig_node, |
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BATADV_IF_DEFAULT); |
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if (!router) { |
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batadv_gw_reselect(bat_priv); |
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goto out; |
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} |
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router_ifinfo = batadv_neigh_ifinfo_get(router, |
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BATADV_IF_DEFAULT); |
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if (!router_ifinfo) { |
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batadv_gw_reselect(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, |
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router_ifinfo->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, |
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router_ifinfo->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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batadv_gw_node_put(curr_gw); |
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batadv_gw_node_put(next_gw); |
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batadv_neigh_node_put(router); |
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batadv_neigh_ifinfo_put(router_ifinfo); |
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} |
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/** |
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* batadv_gw_check_election() - Elect orig node as best gateway when eligible |
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* @bat_priv: the bat priv with all the soft interface information |
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* @orig_node: orig node which is to be checked |
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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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/* abort immediately if the routing algorithm does not support gateway |
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* election |
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*/ |
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if (!bat_priv->algo_ops->gw.is_eligible) |
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return; |
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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 reselect; |
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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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if (!bat_priv->algo_ops->gw.is_eligible(bat_priv, curr_gw_orig, |
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orig_node)) |
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goto out; |
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reselect: |
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batadv_gw_reselect(bat_priv); |
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out: |
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batadv_orig_node_put(curr_gw_orig); |
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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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* Has to be called with the appropriate locks being acquired |
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* (gw.list_lock). |
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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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lockdep_assert_held(&bat_priv->gw.list_lock); |
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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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kref_init(&gw_node->refcount); |
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INIT_HLIST_NODE(&gw_node->list); |
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kref_get(&orig_node->refcount); |
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gw_node->orig_node = orig_node; |
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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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kref_get(&gw_node->refcount); |
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hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.gateway_list); |
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bat_priv->gw.generation++; |
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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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/* don't return reference to new gw_node */ |
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batadv_gw_node_put(gw_node); |
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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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* Return: gateway node if found or NULL otherwise. |
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*/ |
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struct batadv_gw_node *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.gateway_list, |
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list) { |
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if (gw_node_tmp->orig_node != orig_node) |
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continue; |
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if (!kref_get_unless_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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spin_lock_bh(&bat_priv->gw.list_lock); |
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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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spin_unlock_bh(&bat_priv->gw.list_lock); |
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goto out; |
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} |
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spin_unlock_bh(&bat_priv->gw.list_lock); |
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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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if (ntohl(gateway->bandwidth_down) == 0) { |
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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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/* 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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spin_lock_bh(&bat_priv->gw.list_lock); |
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if (!hlist_unhashed(&gw_node->list)) { |
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hlist_del_init_rcu(&gw_node->list); |
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batadv_gw_node_put(gw_node); |
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bat_priv->gw.generation++; |
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} |
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spin_unlock_bh(&bat_priv->gw.list_lock); |
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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_reselect(bat_priv); |
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batadv_gw_node_put(curr_gw); |
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} |
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out: |
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batadv_gw_node_put(gw_node); |
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} |
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/** |
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* batadv_gw_node_delete() - Remove orig_node from gateway list |
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* @bat_priv: the bat priv with all the soft interface information |
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* @orig_node: orig node which is currently in process of being removed |
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*/ |
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void batadv_gw_node_delete(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_tvlv_gateway_data gateway; |
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gateway.bandwidth_down = 0; |
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gateway.bandwidth_up = 0; |
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batadv_gw_node_update(bat_priv, orig_node, &gateway); |
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} |
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/** |
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* batadv_gw_node_free() - Free gateway information from soft interface |
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* @bat_priv: the bat priv with all the soft interface information |
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*/ |
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void batadv_gw_node_free(struct batadv_priv *bat_priv) |
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{ |
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struct batadv_gw_node *gw_node; |
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struct hlist_node *node_tmp; |
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spin_lock_bh(&bat_priv->gw.list_lock); |
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hlist_for_each_entry_safe(gw_node, node_tmp, |
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&bat_priv->gw.gateway_list, list) { |
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hlist_del_init_rcu(&gw_node->list); |
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batadv_gw_node_put(gw_node); |
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bat_priv->gw.generation++; |
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} |
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spin_unlock_bh(&bat_priv->gw.list_lock); |
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} |
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/** |
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* batadv_gw_dump() - Dump gateways into a message |
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* @msg: Netlink message to dump into |
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* @cb: Control block containing additional options |
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* |
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* Return: Error code, or length of message |
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*/ |
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int batadv_gw_dump(struct sk_buff *msg, struct netlink_callback *cb) |
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{ |
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struct batadv_hard_iface *primary_if = NULL; |
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struct net *net = sock_net(cb->skb->sk); |
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struct net_device *soft_iface; |
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struct batadv_priv *bat_priv; |
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int ifindex; |
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int ret; |
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ifindex = batadv_netlink_get_ifindex(cb->nlh, |
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BATADV_ATTR_MESH_IFINDEX); |
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if (!ifindex) |
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return -EINVAL; |
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soft_iface = dev_get_by_index(net, ifindex); |
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if (!soft_iface || !batadv_softif_is_valid(soft_iface)) { |
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ret = -ENODEV; |
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goto out; |
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} |
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bat_priv = netdev_priv(soft_iface); |
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|
|
primary_if = batadv_primary_if_get_selected(bat_priv); |
|
if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
if (!bat_priv->algo_ops->gw.dump) { |
|
ret = -EOPNOTSUPP; |
|
goto out; |
|
} |
|
|
|
bat_priv->algo_ops->gw.dump(msg, cb, bat_priv); |
|
|
|
ret = msg->len; |
|
|
|
out: |
|
batadv_hardif_put(primary_if); |
|
dev_put(soft_iface); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* batadv_gw_dhcp_recipient_get() - check if a packet is a DHCP message |
|
* @skb: the packet to check |
|
* @header_len: a pointer to the batman-adv header size |
|
* @chaddr: buffer where the client address will be stored. Valid |
|
* only if the function returns BATADV_DHCP_TO_CLIENT |
|
* |
|
* This function may re-allocate the data buffer of the skb passed as argument. |
|
* |
|
* Return: |
|
* - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error |
|
* while parsing it |
|
* - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server |
|
* - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client |
|
*/ |
|
enum batadv_dhcp_recipient |
|
batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len, |
|
u8 *chaddr) |
|
{ |
|
enum batadv_dhcp_recipient ret = BATADV_DHCP_NO; |
|
struct ethhdr *ethhdr; |
|
struct iphdr *iphdr; |
|
struct ipv6hdr *ipv6hdr; |
|
struct udphdr *udphdr; |
|
struct vlan_ethhdr *vhdr; |
|
int chaddr_offset; |
|
__be16 proto; |
|
u8 *p; |
|
|
|
/* check for ethernet header */ |
|
if (!pskb_may_pull(skb, *header_len + ETH_HLEN)) |
|
return BATADV_DHCP_NO; |
|
|
|
ethhdr = eth_hdr(skb); |
|
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 BATADV_DHCP_NO; |
|
|
|
vhdr = vlan_eth_hdr(skb); |
|
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 BATADV_DHCP_NO; |
|
|
|
iphdr = (struct iphdr *)(skb->data + *header_len); |
|
*header_len += iphdr->ihl * 4; |
|
|
|
/* check for udp header */ |
|
if (iphdr->protocol != IPPROTO_UDP) |
|
return BATADV_DHCP_NO; |
|
|
|
break; |
|
case htons(ETH_P_IPV6): |
|
if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr))) |
|
return BATADV_DHCP_NO; |
|
|
|
ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len); |
|
*header_len += sizeof(*ipv6hdr); |
|
|
|
/* check for udp header */ |
|
if (ipv6hdr->nexthdr != IPPROTO_UDP) |
|
return BATADV_DHCP_NO; |
|
|
|
break; |
|
default: |
|
return BATADV_DHCP_NO; |
|
} |
|
|
|
if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr))) |
|
return BATADV_DHCP_NO; |
|
|
|
udphdr = (struct udphdr *)(skb->data + *header_len); |
|
*header_len += sizeof(*udphdr); |
|
|
|
/* check for bootp port */ |
|
switch (proto) { |
|
case htons(ETH_P_IP): |
|
if (udphdr->dest == htons(67)) |
|
ret = BATADV_DHCP_TO_SERVER; |
|
else if (udphdr->source == htons(67)) |
|
ret = BATADV_DHCP_TO_CLIENT; |
|
break; |
|
case htons(ETH_P_IPV6): |
|
if (udphdr->dest == htons(547)) |
|
ret = BATADV_DHCP_TO_SERVER; |
|
else if (udphdr->source == htons(547)) |
|
ret = BATADV_DHCP_TO_CLIENT; |
|
break; |
|
} |
|
|
|
chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET; |
|
/* store the client address if the message is going to a client */ |
|
if (ret == BATADV_DHCP_TO_CLIENT) { |
|
if (!pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) |
|
return BATADV_DHCP_NO; |
|
|
|
/* check if the DHCP packet carries an Ethernet DHCP */ |
|
p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET; |
|
if (*p != BATADV_DHCP_HTYPE_ETHERNET) |
|
return BATADV_DHCP_NO; |
|
|
|
/* check if the DHCP packet carries a valid Ethernet address */ |
|
p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET; |
|
if (*p != ETH_ALEN) |
|
return BATADV_DHCP_NO; |
|
|
|
ether_addr_copy(chaddr, skb->data + chaddr_offset); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* batadv_gw_out_of_range() - check if the dhcp request destination is the best |
|
* gateway |
|
* @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. |
|
* |
|
* This call might reallocate skb data. |
|
* Must be invoked only when the DHCP packet is going TO a DHCP SERVER. |
|
* |
|
* Return: true if the packet destination is unicast and it is not the best gw, |
|
* false otherwise. |
|
*/ |
|
bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, |
|
struct sk_buff *skb) |
|
{ |
|
struct batadv_neigh_node *neigh_curr = NULL; |
|
struct batadv_neigh_node *neigh_old = NULL; |
|
struct batadv_orig_node *orig_dst_node = NULL; |
|
struct batadv_gw_node *gw_node = NULL; |
|
struct batadv_gw_node *curr_gw = NULL; |
|
struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo; |
|
struct ethhdr *ethhdr = (struct ethhdr *)skb->data; |
|
bool out_of_range = false; |
|
u8 curr_tq_avg; |
|
unsigned short vid; |
|
|
|
vid = batadv_get_vid(skb, 0); |
|
|
|
if (is_multicast_ether_addr(ethhdr->h_dest)) |
|
goto out; |
|
|
|
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) |
|
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_ifinfo = batadv_neigh_ifinfo_get(neigh_curr, |
|
BATADV_IF_DEFAULT); |
|
if (!curr_ifinfo) |
|
goto out; |
|
|
|
curr_tq_avg = curr_ifinfo->bat_iv.tq_avg; |
|
batadv_neigh_ifinfo_put(curr_ifinfo); |
|
|
|
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; |
|
|
|
old_ifinfo = batadv_neigh_ifinfo_get(neigh_old, BATADV_IF_DEFAULT); |
|
if (!old_ifinfo) |
|
goto out; |
|
|
|
if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD) |
|
out_of_range = true; |
|
batadv_neigh_ifinfo_put(old_ifinfo); |
|
|
|
out: |
|
batadv_orig_node_put(orig_dst_node); |
|
batadv_gw_node_put(curr_gw); |
|
batadv_gw_node_put(gw_node); |
|
batadv_neigh_node_put(neigh_old); |
|
batadv_neigh_node_put(neigh_curr); |
|
return out_of_range; |
|
}
|
|
|