linux/net/batman-adv/hard-interface.c

689 lines
17 KiB
C

/*
* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "main.h"
#include "hard-interface.h"
#include "soft-interface.h"
#include "send.h"
#include "translation-table.h"
#include "routing.h"
#include "bat_sysfs.h"
#include "originator.h"
#include "hash.h"
#include <linux/if_arp.h>
static int batman_skb_recv(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *ptype,
struct net_device *orig_dev);
void hardif_free_rcu(struct rcu_head *rcu)
{
struct hard_iface *hard_iface;
hard_iface = container_of(rcu, struct hard_iface, rcu);
dev_put(hard_iface->net_dev);
kfree(hard_iface);
}
struct hard_iface *hardif_get_by_netdev(const struct net_device *net_dev)
{
struct hard_iface *hard_iface;
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->net_dev == net_dev &&
atomic_inc_not_zero(&hard_iface->refcount))
goto out;
}
hard_iface = NULL;
out:
rcu_read_unlock();
return hard_iface;
}
static int is_valid_iface(const struct net_device *net_dev)
{
if (net_dev->flags & IFF_LOOPBACK)
return 0;
if (net_dev->type != ARPHRD_ETHER)
return 0;
if (net_dev->addr_len != ETH_ALEN)
return 0;
/* no batman over batman */
if (softif_is_valid(net_dev))
return 0;
/* Device is being bridged */
/* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
return 0; */
return 1;
}
static struct hard_iface *hardif_get_active(const struct net_device *soft_iface)
{
struct hard_iface *hard_iface;
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
if (hard_iface->if_status == IF_ACTIVE &&
atomic_inc_not_zero(&hard_iface->refcount))
goto out;
}
hard_iface = NULL;
out:
rcu_read_unlock();
return hard_iface;
}
static void primary_if_update_addr(struct bat_priv *bat_priv)
{
struct vis_packet *vis_packet;
struct hard_iface *primary_if;
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
vis_packet = (struct vis_packet *)
bat_priv->my_vis_info->skb_packet->data;
memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
memcpy(vis_packet->sender_orig,
primary_if->net_dev->dev_addr, ETH_ALEN);
out:
if (primary_if)
hardif_free_ref(primary_if);
}
static void primary_if_select(struct bat_priv *bat_priv,
struct hard_iface *new_hard_iface)
{
struct hard_iface *curr_hard_iface;
ASSERT_RTNL();
if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
new_hard_iface = NULL;
curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
if (curr_hard_iface)
hardif_free_ref(curr_hard_iface);
if (!new_hard_iface)
return;
bat_priv->bat_algo_ops->bat_ogm_init_primary(new_hard_iface);
primary_if_update_addr(bat_priv);
}
static bool hardif_is_iface_up(const struct hard_iface *hard_iface)
{
if (hard_iface->net_dev->flags & IFF_UP)
return true;
return false;
}
static void check_known_mac_addr(const struct net_device *net_dev)
{
const struct hard_iface *hard_iface;
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if ((hard_iface->if_status != IF_ACTIVE) &&
(hard_iface->if_status != IF_TO_BE_ACTIVATED))
continue;
if (hard_iface->net_dev == net_dev)
continue;
if (!compare_eth(hard_iface->net_dev->dev_addr,
net_dev->dev_addr))
continue;
pr_warning("The newly added mac address (%pM) already exists on: %s\n",
net_dev->dev_addr, hard_iface->net_dev->name);
pr_warning("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
}
rcu_read_unlock();
}
int hardif_min_mtu(struct net_device *soft_iface)
{
const struct bat_priv *bat_priv = netdev_priv(soft_iface);
const struct hard_iface *hard_iface;
/* allow big frames if all devices are capable to do so
* (have MTU > 1500 + BAT_HEADER_LEN) */
int min_mtu = ETH_DATA_LEN;
if (atomic_read(&bat_priv->fragmentation))
goto out;
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if ((hard_iface->if_status != IF_ACTIVE) &&
(hard_iface->if_status != IF_TO_BE_ACTIVATED))
continue;
if (hard_iface->soft_iface != soft_iface)
continue;
min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
min_mtu);
}
rcu_read_unlock();
out:
return min_mtu;
}
/* adjusts the MTU if a new interface with a smaller MTU appeared. */
void update_min_mtu(struct net_device *soft_iface)
{
int min_mtu;
min_mtu = hardif_min_mtu(soft_iface);
if (soft_iface->mtu != min_mtu)
soft_iface->mtu = min_mtu;
}
static void hardif_activate_interface(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv;
struct hard_iface *primary_if = NULL;
if (hard_iface->if_status != IF_INACTIVE)
goto out;
bat_priv = netdev_priv(hard_iface->soft_iface);
bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface);
hard_iface->if_status = IF_TO_BE_ACTIVATED;
/**
* the first active interface becomes our primary interface or
* the next active interface after the old primary interface was removed
*/
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
primary_if_select(bat_priv, hard_iface);
bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
hard_iface->net_dev->name);
update_min_mtu(hard_iface->soft_iface);
out:
if (primary_if)
hardif_free_ref(primary_if);
}
static void hardif_deactivate_interface(struct hard_iface *hard_iface)
{
if ((hard_iface->if_status != IF_ACTIVE) &&
(hard_iface->if_status != IF_TO_BE_ACTIVATED))
return;
hard_iface->if_status = IF_INACTIVE;
bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
hard_iface->net_dev->name);
update_min_mtu(hard_iface->soft_iface);
}
int hardif_enable_interface(struct hard_iface *hard_iface,
const char *iface_name)
{
struct bat_priv *bat_priv;
struct net_device *soft_iface;
int ret;
if (hard_iface->if_status != IF_NOT_IN_USE)
goto out;
if (!atomic_inc_not_zero(&hard_iface->refcount))
goto out;
/* hard-interface is part of a bridge */
if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT)
pr_err("You are about to enable batman-adv on '%s' which already is part of a bridge. Unless you know exactly what you are doing this is probably wrong and won't work the way you think it would.\n",
hard_iface->net_dev->name);
soft_iface = dev_get_by_name(&init_net, iface_name);
if (!soft_iface) {
soft_iface = softif_create(iface_name);
if (!soft_iface) {
ret = -ENOMEM;
goto err;
}
/* dev_get_by_name() increases the reference counter for us */
dev_hold(soft_iface);
}
if (!softif_is_valid(soft_iface)) {
pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
soft_iface->name);
dev_put(soft_iface);
ret = -EINVAL;
goto err;
}
hard_iface->soft_iface = soft_iface;
bat_priv = netdev_priv(hard_iface->soft_iface);
bat_priv->bat_algo_ops->bat_ogm_init(hard_iface);
if (!hard_iface->packet_buff) {
bat_err(hard_iface->soft_iface,
"Can't add interface packet (%s): out of memory\n",
hard_iface->net_dev->name);
ret = -ENOMEM;
goto err;
}
hard_iface->if_num = bat_priv->num_ifaces;
bat_priv->num_ifaces++;
hard_iface->if_status = IF_INACTIVE;
orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
hard_iface->batman_adv_ptype.func = batman_skb_recv;
hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
dev_add_pack(&hard_iface->batman_adv_ptype);
atomic_set(&hard_iface->seqno, 1);
atomic_set(&hard_iface->frag_seqno, 1);
bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
hard_iface->net_dev->name);
if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
ETH_DATA_LEN + BAT_HEADER_LEN)
bat_info(hard_iface->soft_iface,
"The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %zi would solve the problem.\n",
hard_iface->net_dev->name, hard_iface->net_dev->mtu,
ETH_DATA_LEN + BAT_HEADER_LEN);
if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
ETH_DATA_LEN + BAT_HEADER_LEN)
bat_info(hard_iface->soft_iface,
"The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %zi.\n",
hard_iface->net_dev->name, hard_iface->net_dev->mtu,
ETH_DATA_LEN + BAT_HEADER_LEN);
if (hardif_is_iface_up(hard_iface))
hardif_activate_interface(hard_iface);
else
bat_err(hard_iface->soft_iface,
"Not using interface %s (retrying later): interface not active\n",
hard_iface->net_dev->name);
/* begin scheduling originator messages on that interface */
schedule_bat_ogm(hard_iface);
out:
return 0;
err:
hardif_free_ref(hard_iface);
return ret;
}
void hardif_disable_interface(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct hard_iface *primary_if = NULL;
if (hard_iface->if_status == IF_ACTIVE)
hardif_deactivate_interface(hard_iface);
if (hard_iface->if_status != IF_INACTIVE)
goto out;
bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
hard_iface->net_dev->name);
dev_remove_pack(&hard_iface->batman_adv_ptype);
bat_priv->num_ifaces--;
orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
primary_if = primary_if_get_selected(bat_priv);
if (hard_iface == primary_if) {
struct hard_iface *new_if;
new_if = hardif_get_active(hard_iface->soft_iface);
primary_if_select(bat_priv, new_if);
if (new_if)
hardif_free_ref(new_if);
}
kfree(hard_iface->packet_buff);
hard_iface->packet_buff = NULL;
hard_iface->if_status = IF_NOT_IN_USE;
/* delete all references to this hard_iface */
purge_orig_ref(bat_priv);
purge_outstanding_packets(bat_priv, hard_iface);
dev_put(hard_iface->soft_iface);
/* nobody uses this interface anymore */
if (!bat_priv->num_ifaces)
softif_destroy(hard_iface->soft_iface);
hard_iface->soft_iface = NULL;
hardif_free_ref(hard_iface);
out:
if (primary_if)
hardif_free_ref(primary_if);
}
static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
{
struct hard_iface *hard_iface;
int ret;
ASSERT_RTNL();
ret = is_valid_iface(net_dev);
if (ret != 1)
goto out;
dev_hold(net_dev);
hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC);
if (!hard_iface)
goto release_dev;
ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
if (ret)
goto free_if;
hard_iface->if_num = -1;
hard_iface->net_dev = net_dev;
hard_iface->soft_iface = NULL;
hard_iface->if_status = IF_NOT_IN_USE;
INIT_LIST_HEAD(&hard_iface->list);
/* extra reference for return */
atomic_set(&hard_iface->refcount, 2);
check_known_mac_addr(hard_iface->net_dev);
list_add_tail_rcu(&hard_iface->list, &hardif_list);
return hard_iface;
free_if:
kfree(hard_iface);
release_dev:
dev_put(net_dev);
out:
return NULL;
}
static void hardif_remove_interface(struct hard_iface *hard_iface)
{
ASSERT_RTNL();
/* first deactivate interface */
if (hard_iface->if_status != IF_NOT_IN_USE)
hardif_disable_interface(hard_iface);
if (hard_iface->if_status != IF_NOT_IN_USE)
return;
hard_iface->if_status = IF_TO_BE_REMOVED;
sysfs_del_hardif(&hard_iface->hardif_obj);
hardif_free_ref(hard_iface);
}
void hardif_remove_interfaces(void)
{
struct hard_iface *hard_iface, *hard_iface_tmp;
rtnl_lock();
list_for_each_entry_safe(hard_iface, hard_iface_tmp,
&hardif_list, list) {
list_del_rcu(&hard_iface->list);
hardif_remove_interface(hard_iface);
}
rtnl_unlock();
}
static int hard_if_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *net_dev = ptr;
struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
struct hard_iface *primary_if = NULL;
struct bat_priv *bat_priv;
if (!hard_iface && event == NETDEV_REGISTER)
hard_iface = hardif_add_interface(net_dev);
if (!hard_iface)
goto out;
switch (event) {
case NETDEV_UP:
hardif_activate_interface(hard_iface);
break;
case NETDEV_GOING_DOWN:
case NETDEV_DOWN:
hardif_deactivate_interface(hard_iface);
break;
case NETDEV_UNREGISTER:
list_del_rcu(&hard_iface->list);
hardif_remove_interface(hard_iface);
break;
case NETDEV_CHANGEMTU:
if (hard_iface->soft_iface)
update_min_mtu(hard_iface->soft_iface);
break;
case NETDEV_CHANGEADDR:
if (hard_iface->if_status == IF_NOT_IN_USE)
goto hardif_put;
check_known_mac_addr(hard_iface->net_dev);
bat_priv = netdev_priv(hard_iface->soft_iface);
bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface);
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto hardif_put;
if (hard_iface == primary_if)
primary_if_update_addr(bat_priv);
break;
default:
break;
}
hardif_put:
hardif_free_ref(hard_iface);
out:
if (primary_if)
hardif_free_ref(primary_if);
return NOTIFY_DONE;
}
/* incoming packets with the batman ethertype received on any active hard
* interface */
static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *ptype,
struct net_device *orig_dev)
{
struct bat_priv *bat_priv;
struct batman_ogm_packet *batman_ogm_packet;
struct hard_iface *hard_iface;
int ret;
hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
skb = skb_share_check(skb, GFP_ATOMIC);
/* skb was released by skb_share_check() */
if (!skb)
goto err_out;
/* packet should hold at least type and version */
if (unlikely(!pskb_may_pull(skb, 2)))
goto err_free;
/* expect a valid ethernet header here. */
if (unlikely(skb->mac_len != sizeof(struct ethhdr) ||
!skb_mac_header(skb)))
goto err_free;
if (!hard_iface->soft_iface)
goto err_free;
bat_priv = netdev_priv(hard_iface->soft_iface);
if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
goto err_free;
/* discard frames on not active interfaces */
if (hard_iface->if_status != IF_ACTIVE)
goto err_free;
batman_ogm_packet = (struct batman_ogm_packet *)skb->data;
if (batman_ogm_packet->header.version != COMPAT_VERSION) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: incompatible batman version (%i)\n",
batman_ogm_packet->header.version);
goto err_free;
}
/* all receive handlers return whether they received or reused
* the supplied skb. if not, we have to free the skb. */
switch (batman_ogm_packet->header.packet_type) {
/* batman originator packet */
case BAT_OGM:
ret = recv_bat_ogm_packet(skb, hard_iface);
break;
/* batman icmp packet */
case BAT_ICMP:
ret = recv_icmp_packet(skb, hard_iface);
break;
/* unicast packet */
case BAT_UNICAST:
ret = recv_unicast_packet(skb, hard_iface);
break;
/* fragmented unicast packet */
case BAT_UNICAST_FRAG:
ret = recv_ucast_frag_packet(skb, hard_iface);
break;
/* broadcast packet */
case BAT_BCAST:
ret = recv_bcast_packet(skb, hard_iface);
break;
/* vis packet */
case BAT_VIS:
ret = recv_vis_packet(skb, hard_iface);
break;
/* Translation table query (request or response) */
case BAT_TT_QUERY:
ret = recv_tt_query(skb, hard_iface);
break;
/* Roaming advertisement */
case BAT_ROAM_ADV:
ret = recv_roam_adv(skb, hard_iface);
break;
default:
ret = NET_RX_DROP;
}
if (ret == NET_RX_DROP)
kfree_skb(skb);
/* return NET_RX_SUCCESS in any case as we
* most probably dropped the packet for
* routing-logical reasons. */
return NET_RX_SUCCESS;
err_free:
kfree_skb(skb);
err_out:
return NET_RX_DROP;
}
/* This function returns true if the interface represented by ifindex is a
* 802.11 wireless device */
bool is_wifi_iface(int ifindex)
{
struct net_device *net_device = NULL;
bool ret = false;
if (ifindex == NULL_IFINDEX)
goto out;
net_device = dev_get_by_index(&init_net, ifindex);
if (!net_device)
goto out;
#ifdef CONFIG_WIRELESS_EXT
/* pre-cfg80211 drivers have to implement WEXT, so it is possible to
* check for wireless_handlers != NULL */
if (net_device->wireless_handlers)
ret = true;
else
#endif
/* cfg80211 drivers have to set ieee80211_ptr */
if (net_device->ieee80211_ptr)
ret = true;
out:
if (net_device)
dev_put(net_device);
return ret;
}
struct notifier_block hard_if_notifier = {
.notifier_call = hard_if_event,
};