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

652 lines
16 KiB
C

/*
* Copyright (C) 2007-2010 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>
/* protect update critical side of if_list - but not the content */
static DEFINE_SPINLOCK(if_list_lock);
static void hardif_free_rcu(struct rcu_head *rcu)
{
struct batman_if *batman_if;
batman_if = container_of(rcu, struct batman_if, rcu);
dev_put(batman_if->net_dev);
kref_put(&batman_if->refcount, hardif_free_ref);
}
struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev)
{
struct batman_if *batman_if;
rcu_read_lock();
list_for_each_entry_rcu(batman_if, &if_list, list) {
if (batman_if->net_dev == net_dev)
goto out;
}
batman_if = NULL;
out:
if (batman_if)
kref_get(&batman_if->refcount);
rcu_read_unlock();
return batman_if;
}
static int is_valid_iface(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 */
#ifdef HAVE_NET_DEVICE_OPS
if (net_dev->netdev_ops->ndo_start_xmit == interface_tx)
return 0;
#else
if (net_dev->hard_start_xmit == interface_tx)
return 0;
#endif
/* Device is being bridged */
/* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
return 0; */
return 1;
}
static struct batman_if *get_active_batman_if(struct net_device *soft_iface)
{
struct batman_if *batman_if;
rcu_read_lock();
list_for_each_entry_rcu(batman_if, &if_list, list) {
if (batman_if->soft_iface != soft_iface)
continue;
if (batman_if->if_status == IF_ACTIVE)
goto out;
}
batman_if = NULL;
out:
if (batman_if)
kref_get(&batman_if->refcount);
rcu_read_unlock();
return batman_if;
}
static void update_primary_addr(struct bat_priv *bat_priv)
{
struct vis_packet *vis_packet;
vis_packet = (struct vis_packet *)
bat_priv->my_vis_info->skb_packet->data;
memcpy(vis_packet->vis_orig,
bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
memcpy(vis_packet->sender_orig,
bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
}
static void set_primary_if(struct bat_priv *bat_priv,
struct batman_if *batman_if)
{
struct batman_packet *batman_packet;
struct batman_if *old_if;
if (batman_if)
kref_get(&batman_if->refcount);
old_if = bat_priv->primary_if;
bat_priv->primary_if = batman_if;
if (old_if)
kref_put(&old_if->refcount, hardif_free_ref);
if (!bat_priv->primary_if)
return;
batman_packet = (struct batman_packet *)(batman_if->packet_buff);
batman_packet->flags = PRIMARIES_FIRST_HOP;
batman_packet->ttl = TTL;
update_primary_addr(bat_priv);
/***
* hacky trick to make sure that we send the HNA information via
* our new primary interface
*/
atomic_set(&bat_priv->hna_local_changed, 1);
}
static bool hardif_is_iface_up(struct batman_if *batman_if)
{
if (batman_if->net_dev->flags & IFF_UP)
return true;
return false;
}
static void update_mac_addresses(struct batman_if *batman_if)
{
memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
batman_if->net_dev->dev_addr, ETH_ALEN);
memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
batman_if->net_dev->dev_addr, ETH_ALEN);
}
static void check_known_mac_addr(struct net_device *net_dev)
{
struct batman_if *batman_if;
rcu_read_lock();
list_for_each_entry_rcu(batman_if, &if_list, list) {
if ((batman_if->if_status != IF_ACTIVE) &&
(batman_if->if_status != IF_TO_BE_ACTIVATED))
continue;
if (batman_if->net_dev == net_dev)
continue;
if (!compare_orig(batman_if->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,
batman_if->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)
{
struct bat_priv *bat_priv = netdev_priv(soft_iface);
struct batman_if *batman_if;
/* 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(batman_if, &if_list, list) {
if ((batman_if->if_status != IF_ACTIVE) &&
(batman_if->if_status != IF_TO_BE_ACTIVATED))
continue;
if (batman_if->soft_iface != soft_iface)
continue;
min_mtu = min_t(int, batman_if->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 batman_if *batman_if)
{
struct bat_priv *bat_priv;
if (batman_if->if_status != IF_INACTIVE)
return;
bat_priv = netdev_priv(batman_if->soft_iface);
update_mac_addresses(batman_if);
batman_if->if_status = IF_TO_BE_ACTIVATED;
/**
* the first active interface becomes our primary interface or
* the next active interface after the old primay interface was removed
*/
if (!bat_priv->primary_if)
set_primary_if(bat_priv, batman_if);
bat_info(batman_if->soft_iface, "Interface activated: %s\n",
batman_if->net_dev->name);
update_min_mtu(batman_if->soft_iface);
return;
}
static void hardif_deactivate_interface(struct batman_if *batman_if)
{
if ((batman_if->if_status != IF_ACTIVE) &&
(batman_if->if_status != IF_TO_BE_ACTIVATED))
return;
batman_if->if_status = IF_INACTIVE;
bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
batman_if->net_dev->name);
update_min_mtu(batman_if->soft_iface);
}
int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
{
struct bat_priv *bat_priv;
struct batman_packet *batman_packet;
if (batman_if->if_status != IF_NOT_IN_USE)
goto out;
batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
if (!batman_if->soft_iface) {
batman_if->soft_iface = softif_create(iface_name);
if (!batman_if->soft_iface)
goto err;
/* dev_get_by_name() increases the reference counter for us */
dev_hold(batman_if->soft_iface);
}
bat_priv = netdev_priv(batman_if->soft_iface);
batman_if->packet_len = BAT_PACKET_LEN;
batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
if (!batman_if->packet_buff) {
bat_err(batman_if->soft_iface, "Can't add interface packet "
"(%s): out of memory\n", batman_if->net_dev->name);
goto err;
}
batman_packet = (struct batman_packet *)(batman_if->packet_buff);
batman_packet->packet_type = BAT_PACKET;
batman_packet->version = COMPAT_VERSION;
batman_packet->flags = 0;
batman_packet->ttl = 2;
batman_packet->tq = TQ_MAX_VALUE;
batman_packet->num_hna = 0;
batman_if->if_num = bat_priv->num_ifaces;
bat_priv->num_ifaces++;
batman_if->if_status = IF_INACTIVE;
orig_hash_add_if(batman_if, bat_priv->num_ifaces);
batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
batman_if->batman_adv_ptype.func = batman_skb_recv;
batman_if->batman_adv_ptype.dev = batman_if->net_dev;
kref_get(&batman_if->refcount);
dev_add_pack(&batman_if->batman_adv_ptype);
atomic_set(&batman_if->seqno, 1);
atomic_set(&batman_if->frag_seqno, 1);
bat_info(batman_if->soft_iface, "Adding interface: %s\n",
batman_if->net_dev->name);
if (atomic_read(&bat_priv->fragmentation) && batman_if->net_dev->mtu <
ETH_DATA_LEN + BAT_HEADER_LEN)
bat_info(batman_if->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",
batman_if->net_dev->name, batman_if->net_dev->mtu,
ETH_DATA_LEN + BAT_HEADER_LEN);
if (!atomic_read(&bat_priv->fragmentation) && batman_if->net_dev->mtu <
ETH_DATA_LEN + BAT_HEADER_LEN)
bat_info(batman_if->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",
batman_if->net_dev->name, batman_if->net_dev->mtu,
ETH_DATA_LEN + BAT_HEADER_LEN);
if (hardif_is_iface_up(batman_if))
hardif_activate_interface(batman_if);
else
bat_err(batman_if->soft_iface, "Not using interface %s "
"(retrying later): interface not active\n",
batman_if->net_dev->name);
/* begin scheduling originator messages on that interface */
schedule_own_packet(batman_if);
out:
return 0;
err:
return -ENOMEM;
}
void hardif_disable_interface(struct batman_if *batman_if)
{
struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
if (batman_if->if_status == IF_ACTIVE)
hardif_deactivate_interface(batman_if);
if (batman_if->if_status != IF_INACTIVE)
return;
bat_info(batman_if->soft_iface, "Removing interface: %s\n",
batman_if->net_dev->name);
dev_remove_pack(&batman_if->batman_adv_ptype);
kref_put(&batman_if->refcount, hardif_free_ref);
bat_priv->num_ifaces--;
orig_hash_del_if(batman_if, bat_priv->num_ifaces);
if (batman_if == bat_priv->primary_if) {
struct batman_if *new_if;
new_if = get_active_batman_if(batman_if->soft_iface);
set_primary_if(bat_priv, new_if);
if (new_if)
kref_put(&new_if->refcount, hardif_free_ref);
}
kfree(batman_if->packet_buff);
batman_if->packet_buff = NULL;
batman_if->if_status = IF_NOT_IN_USE;
/* delete all references to this batman_if */
purge_orig_ref(bat_priv);
purge_outstanding_packets(bat_priv, batman_if);
dev_put(batman_if->soft_iface);
/* nobody uses this interface anymore */
if (!bat_priv->num_ifaces)
softif_destroy(batman_if->soft_iface);
batman_if->soft_iface = NULL;
}
static struct batman_if *hardif_add_interface(struct net_device *net_dev)
{
struct batman_if *batman_if;
int ret;
ret = is_valid_iface(net_dev);
if (ret != 1)
goto out;
dev_hold(net_dev);
batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
if (!batman_if) {
pr_err("Can't add interface (%s): out of memory\n",
net_dev->name);
goto release_dev;
}
ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
if (ret)
goto free_if;
batman_if->if_num = -1;
batman_if->net_dev = net_dev;
batman_if->soft_iface = NULL;
batman_if->if_status = IF_NOT_IN_USE;
INIT_LIST_HEAD(&batman_if->list);
kref_init(&batman_if->refcount);
check_known_mac_addr(batman_if->net_dev);
spin_lock(&if_list_lock);
list_add_tail_rcu(&batman_if->list, &if_list);
spin_unlock(&if_list_lock);
/* extra reference for return */
kref_get(&batman_if->refcount);
return batman_if;
free_if:
kfree(batman_if);
release_dev:
dev_put(net_dev);
out:
return NULL;
}
static void hardif_remove_interface(struct batman_if *batman_if)
{
/* first deactivate interface */
if (batman_if->if_status != IF_NOT_IN_USE)
hardif_disable_interface(batman_if);
if (batman_if->if_status != IF_NOT_IN_USE)
return;
batman_if->if_status = IF_TO_BE_REMOVED;
sysfs_del_hardif(&batman_if->hardif_obj);
call_rcu(&batman_if->rcu, hardif_free_rcu);
}
void hardif_remove_interfaces(void)
{
struct batman_if *batman_if, *batman_if_tmp;
struct list_head if_queue;
INIT_LIST_HEAD(&if_queue);
spin_lock(&if_list_lock);
list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
list_del_rcu(&batman_if->list);
list_add_tail(&batman_if->list, &if_queue);
}
spin_unlock(&if_list_lock);
rtnl_lock();
list_for_each_entry_safe(batman_if, batman_if_tmp, &if_queue, list) {
hardif_remove_interface(batman_if);
}
rtnl_unlock();
}
static int hard_if_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *net_dev = (struct net_device *)ptr;
struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
struct bat_priv *bat_priv;
if (!batman_if && event == NETDEV_REGISTER)
batman_if = hardif_add_interface(net_dev);
if (!batman_if)
goto out;
switch (event) {
case NETDEV_UP:
hardif_activate_interface(batman_if);
break;
case NETDEV_GOING_DOWN:
case NETDEV_DOWN:
hardif_deactivate_interface(batman_if);
break;
case NETDEV_UNREGISTER:
spin_lock(&if_list_lock);
list_del_rcu(&batman_if->list);
spin_unlock(&if_list_lock);
hardif_remove_interface(batman_if);
break;
case NETDEV_CHANGEMTU:
if (batman_if->soft_iface)
update_min_mtu(batman_if->soft_iface);
break;
case NETDEV_CHANGEADDR:
if (batman_if->if_status == IF_NOT_IN_USE)
goto hardif_put;
check_known_mac_addr(batman_if->net_dev);
update_mac_addresses(batman_if);
bat_priv = netdev_priv(batman_if->soft_iface);
if (batman_if == bat_priv->primary_if)
update_primary_addr(bat_priv);
break;
default:
break;
};
hardif_put:
kref_put(&batman_if->refcount, hardif_free_ref);
out:
return NOTIFY_DONE;
}
/* receive a packet with the batman ethertype coming on a hard
* interface */
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_packet *batman_packet;
struct batman_if *batman_if;
int ret;
batman_if = container_of(ptype, struct batman_if, 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 (!batman_if->soft_iface)
goto err_free;
bat_priv = netdev_priv(batman_if->soft_iface);
if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
goto err_free;
/* discard frames on not active interfaces */
if (batman_if->if_status != IF_ACTIVE)
goto err_free;
batman_packet = (struct batman_packet *)skb->data;
if (batman_packet->version != COMPAT_VERSION) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: incompatible batman version (%i)\n",
batman_packet->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_packet->packet_type) {
/* batman originator packet */
case BAT_PACKET:
ret = recv_bat_packet(skb, batman_if);
break;
/* batman icmp packet */
case BAT_ICMP:
ret = recv_icmp_packet(skb, batman_if);
break;
/* unicast packet */
case BAT_UNICAST:
ret = recv_unicast_packet(skb, batman_if);
break;
/* fragmented unicast packet */
case BAT_UNICAST_FRAG:
ret = recv_ucast_frag_packet(skb, batman_if);
break;
/* broadcast packet */
case BAT_BCAST:
ret = recv_bcast_packet(skb, batman_if);
break;
/* vis packet */
case BAT_VIS:
ret = recv_vis_packet(skb, batman_if);
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;
}
struct notifier_block hard_if_notifier = {
.notifier_call = hard_if_event,
};