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

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/*
* 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;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
/* 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,
};