diff options
Diffstat (limited to 'net/batman-adv/hard-interface.c')
| -rw-r--r-- | net/batman-adv/hard-interface.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c new file mode 100644 index 00000000..522243af --- /dev/null +++ b/net/batman-adv/hard-interface.c @@ -0,0 +1,694 @@ +/* Copyright (C) 2007-2013 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 "distributed-arp-table.h" +#include "hard-interface.h" +#include "soft-interface.h" +#include "send.h" +#include "translation-table.h" +#include "routing.h" +#include "sysfs.h" +#include "originator.h" +#include "hash.h" +#include "bridge_loop_avoidance.h" + +#include <linux/if_arp.h> +#include <linux/if_ether.h> + +void batadv_hardif_free_rcu(struct rcu_head *rcu) +{ + struct batadv_hard_iface *hard_iface; + + hard_iface = container_of(rcu, struct batadv_hard_iface, rcu); + dev_put(hard_iface->net_dev); + kfree(hard_iface); +} + +struct batadv_hard_iface * +batadv_hardif_get_by_netdev(const struct net_device *net_dev) +{ + struct batadv_hard_iface *hard_iface; + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_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; +} + +/** + * batadv_is_on_batman_iface - check if a device is a batman iface descendant + * @net_dev: the device to check + * + * If the user creates any virtual device on top of a batman-adv interface, it + * is important to prevent this new interface to be used to create a new mesh + * network (this behaviour would lead to a batman-over-batman configuration). + * This function recursively checks all the fathers of the device passed as + * argument looking for a batman-adv soft interface. + * + * Returns true if the device is descendant of a batman-adv mesh interface (or + * if it is a batman-adv interface itself), false otherwise + */ +static bool batadv_is_on_batman_iface(const struct net_device *net_dev) +{ + struct net_device *parent_dev; + bool ret; + + /* check if this is a batman-adv mesh interface */ + if (batadv_softif_is_valid(net_dev)) + return true; + + /* no more parents..stop recursion */ + if (net_dev->iflink == net_dev->ifindex) + return false; + + /* recurse over the parent device */ + parent_dev = dev_get_by_index(&init_net, net_dev->iflink); + /* if we got a NULL parent_dev there is something broken.. */ + if (WARN(!parent_dev, "Cannot find parent device")) + return false; + + ret = batadv_is_on_batman_iface(parent_dev); + + if (parent_dev) + dev_put(parent_dev); + return ret; +} + +static int batadv_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 (batadv_is_on_batman_iface(net_dev)) + return 0; + + return 1; +} + +static struct batadv_hard_iface * +batadv_hardif_get_active(const struct net_device *soft_iface) +{ + struct batadv_hard_iface *hard_iface; + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->soft_iface != soft_iface) + continue; + + if (hard_iface->if_status == BATADV_IF_ACTIVE && + atomic_inc_not_zero(&hard_iface->refcount)) + goto out; + } + + hard_iface = NULL; + +out: + rcu_read_unlock(); + return hard_iface; +} + +static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv, + struct batadv_hard_iface *oldif) +{ + struct batadv_vis_packet *vis_packet; + struct batadv_hard_iface *primary_if; + struct sk_buff *skb; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + batadv_dat_init_own_addr(bat_priv, primary_if); + + skb = bat_priv->vis.my_info->skb_packet; + vis_packet = (struct batadv_vis_packet *)skb->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); + + batadv_bla_update_orig_address(bat_priv, primary_if, oldif); +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); +} + +static void batadv_primary_if_select(struct batadv_priv *bat_priv, + struct batadv_hard_iface *new_hard_iface) +{ + struct batadv_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 (!new_hard_iface) + goto out; + + bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface); + batadv_primary_if_update_addr(bat_priv, curr_hard_iface); + +out: + if (curr_hard_iface) + batadv_hardif_free_ref(curr_hard_iface); +} + +static bool +batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface) +{ + if (hard_iface->net_dev->flags & IFF_UP) + return true; + + return false; +} + +static void batadv_check_known_mac_addr(const struct net_device *net_dev) +{ + const struct batadv_hard_iface *hard_iface; + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if ((hard_iface->if_status != BATADV_IF_ACTIVE) && + (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)) + continue; + + if (hard_iface->net_dev == net_dev) + continue; + + if (!batadv_compare_eth(hard_iface->net_dev->dev_addr, + net_dev->dev_addr)) + continue; + + pr_warn("The newly added mac address (%pM) already exists on: %s\n", + net_dev->dev_addr, hard_iface->net_dev->name); + pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n"); + } + rcu_read_unlock(); +} + +int batadv_hardif_min_mtu(struct net_device *soft_iface) +{ + const struct batadv_priv *bat_priv = netdev_priv(soft_iface); + const struct batadv_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, &batadv_hardif_list, list) { + if ((hard_iface->if_status != BATADV_IF_ACTIVE) && + (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)) + continue; + + if (hard_iface->soft_iface != soft_iface) + continue; + + min_mtu = min_t(int, + hard_iface->net_dev->mtu - BATADV_HEADER_LEN, + min_mtu); + } + rcu_read_unlock(); +out: + return min_mtu; +} + +/* adjusts the MTU if a new interface with a smaller MTU appeared. */ +void batadv_update_min_mtu(struct net_device *soft_iface) +{ + int min_mtu; + + min_mtu = batadv_hardif_min_mtu(soft_iface); + if (soft_iface->mtu != min_mtu) + soft_iface->mtu = min_mtu; +} + +static void +batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv; + struct batadv_hard_iface *primary_if = NULL; + + if (hard_iface->if_status != BATADV_IF_INACTIVE) + goto out; + + bat_priv = netdev_priv(hard_iface->soft_iface); + + bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface); + hard_iface->if_status = BATADV_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 = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + batadv_primary_if_select(bat_priv, hard_iface); + + batadv_info(hard_iface->soft_iface, "Interface activated: %s\n", + hard_iface->net_dev->name); + + batadv_update_min_mtu(hard_iface->soft_iface); + +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); +} + +static void +batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface) +{ + if ((hard_iface->if_status != BATADV_IF_ACTIVE) && + (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)) + return; + + hard_iface->if_status = BATADV_IF_INACTIVE; + + batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n", + hard_iface->net_dev->name); + + batadv_update_min_mtu(hard_iface->soft_iface); +} + +/** + * batadv_master_del_slave - remove hard_iface from the current master interface + * @slave: the interface enslaved in another master + * @master: the master from which slave has to be removed + * + * Invoke ndo_del_slave on master passing slave as argument. In this way slave + * is free'd and master can correctly change its internal state. + * Return 0 on success, a negative value representing the error otherwise + */ +static int batadv_master_del_slave(struct batadv_hard_iface *slave, + struct net_device *master) +{ + int ret; + + if (!master) + return 0; + + ret = -EBUSY; + if (master->netdev_ops->ndo_del_slave) + ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev); + + return ret; +} + +int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, + const char *iface_name) +{ + struct batadv_priv *bat_priv; + struct net_device *soft_iface, *master; + __be16 ethertype = __constant_htons(ETH_P_BATMAN); + int ret; + + if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) + goto out; + + if (!atomic_inc_not_zero(&hard_iface->refcount)) + goto out; + + soft_iface = dev_get_by_name(&init_net, iface_name); + + if (!soft_iface) { + soft_iface = batadv_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 (!batadv_softif_is_valid(soft_iface)) { + pr_err("Can't create batman mesh interface %s: already exists as regular interface\n", + soft_iface->name); + ret = -EINVAL; + goto err_dev; + } + + /* check if the interface is enslaved in another virtual one and + * in that case unlink it first + */ + master = netdev_master_upper_dev_get(hard_iface->net_dev); + ret = batadv_master_del_slave(hard_iface, master); + if (ret) + goto err_dev; + + hard_iface->soft_iface = soft_iface; + bat_priv = netdev_priv(hard_iface->soft_iface); + + ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface); + if (ret) + goto err_dev; + + ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface); + if (ret < 0) + goto err_upper; + + hard_iface->if_num = bat_priv->num_ifaces; + bat_priv->num_ifaces++; + hard_iface->if_status = BATADV_IF_INACTIVE; + ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces); + if (ret < 0) { + bat_priv->bat_algo_ops->bat_iface_disable(hard_iface); + bat_priv->num_ifaces--; + hard_iface->if_status = BATADV_IF_NOT_IN_USE; + goto err_upper; + } + + hard_iface->batman_adv_ptype.type = ethertype; + hard_iface->batman_adv_ptype.func = batadv_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->frag_seqno, 1); + batadv_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 + BATADV_HEADER_LEN) + batadv_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 + BATADV_HEADER_LEN); + + if (!atomic_read(&bat_priv->fragmentation) && + hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN) + batadv_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 + BATADV_HEADER_LEN); + + if (batadv_hardif_is_iface_up(hard_iface)) + batadv_hardif_activate_interface(hard_iface); + else + batadv_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 */ + batadv_schedule_bat_ogm(hard_iface); + +out: + return 0; + +err_upper: + netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface); +err_dev: + hard_iface->soft_iface = NULL; + dev_put(soft_iface); +err: + batadv_hardif_free_ref(hard_iface); + return ret; +} + +void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface, + enum batadv_hard_if_cleanup autodel) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + struct batadv_hard_iface *primary_if = NULL; + + if (hard_iface->if_status == BATADV_IF_ACTIVE) + batadv_hardif_deactivate_interface(hard_iface); + + if (hard_iface->if_status != BATADV_IF_INACTIVE) + goto out; + + batadv_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--; + batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces); + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (hard_iface == primary_if) { + struct batadv_hard_iface *new_if; + + new_if = batadv_hardif_get_active(hard_iface->soft_iface); + batadv_primary_if_select(bat_priv, new_if); + + if (new_if) + batadv_hardif_free_ref(new_if); + } + + bat_priv->bat_algo_ops->bat_iface_disable(hard_iface); + hard_iface->if_status = BATADV_IF_NOT_IN_USE; + + /* delete all references to this hard_iface */ + batadv_purge_orig_ref(bat_priv); + batadv_purge_outstanding_packets(bat_priv, hard_iface); + dev_put(hard_iface->soft_iface); + + /* nobody uses this interface anymore */ + if (!bat_priv->num_ifaces && autodel == BATADV_IF_CLEANUP_AUTO) + batadv_softif_destroy_sysfs(hard_iface->soft_iface); + + netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface); + hard_iface->soft_iface = NULL; + batadv_hardif_free_ref(hard_iface); + +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); +} + +/** + * batadv_hardif_remove_interface_finish - cleans up the remains of a hardif + * @work: work queue item + * + * Free the parts of the hard interface which can not be removed under + * rtnl lock (to prevent deadlock situations). + */ +static void batadv_hardif_remove_interface_finish(struct work_struct *work) +{ + struct batadv_hard_iface *hard_iface; + + hard_iface = container_of(work, struct batadv_hard_iface, + cleanup_work); + + batadv_sysfs_del_hardif(&hard_iface->hardif_obj); + batadv_hardif_free_ref(hard_iface); +} + +static struct batadv_hard_iface * +batadv_hardif_add_interface(struct net_device *net_dev) +{ + struct batadv_hard_iface *hard_iface; + int ret; + + ASSERT_RTNL(); + + ret = batadv_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 = batadv_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 = BATADV_IF_NOT_IN_USE; + INIT_LIST_HEAD(&hard_iface->list); + INIT_WORK(&hard_iface->cleanup_work, + batadv_hardif_remove_interface_finish); + + /* extra reference for return */ + atomic_set(&hard_iface->refcount, 2); + + batadv_check_known_mac_addr(hard_iface->net_dev); + list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list); + + /* This can't be called via a bat_priv callback because + * we have no bat_priv yet. + */ + atomic_set(&hard_iface->bat_iv.ogm_seqno, 1); + hard_iface->bat_iv.ogm_buff = NULL; + + return hard_iface; + +free_if: + kfree(hard_iface); +release_dev: + dev_put(net_dev); +out: + return NULL; +} + +static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface) +{ + ASSERT_RTNL(); + + /* first deactivate interface */ + if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) + batadv_hardif_disable_interface(hard_iface, + BATADV_IF_CLEANUP_AUTO); + + if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) + return; + + hard_iface->if_status = BATADV_IF_TO_BE_REMOVED; + queue_work(batadv_event_workqueue, &hard_iface->cleanup_work); +} + +void batadv_hardif_remove_interfaces(void) +{ + struct batadv_hard_iface *hard_iface, *hard_iface_tmp; + + rtnl_lock(); + list_for_each_entry_safe(hard_iface, hard_iface_tmp, + &batadv_hardif_list, list) { + list_del_rcu(&hard_iface->list); + batadv_hardif_remove_interface(hard_iface); + } + rtnl_unlock(); +} + +static int batadv_hard_if_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *net_dev = ptr; + struct batadv_hard_iface *hard_iface; + struct batadv_hard_iface *primary_if = NULL; + struct batadv_priv *bat_priv; + + if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) { + batadv_sysfs_add_meshif(net_dev); + return NOTIFY_DONE; + } + + hard_iface = batadv_hardif_get_by_netdev(net_dev); + if (!hard_iface && event == NETDEV_REGISTER) + hard_iface = batadv_hardif_add_interface(net_dev); + + if (!hard_iface) + goto out; + + switch (event) { + case NETDEV_UP: + batadv_hardif_activate_interface(hard_iface); + break; + case NETDEV_GOING_DOWN: + case NETDEV_DOWN: + batadv_hardif_deactivate_interface(hard_iface); + break; + case NETDEV_UNREGISTER: + list_del_rcu(&hard_iface->list); + + batadv_hardif_remove_interface(hard_iface); + break; + case NETDEV_CHANGEMTU: + if (hard_iface->soft_iface) + batadv_update_min_mtu(hard_iface->soft_iface); + break; + case NETDEV_CHANGEADDR: + if (hard_iface->if_status == BATADV_IF_NOT_IN_USE) + goto hardif_put; + + batadv_check_known_mac_addr(hard_iface->net_dev); + + bat_priv = netdev_priv(hard_iface->soft_iface); + bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface); + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto hardif_put; + + if (hard_iface == primary_if) + batadv_primary_if_update_addr(bat_priv, NULL); + break; + default: + break; + } + +hardif_put: + batadv_hardif_free_ref(hard_iface); +out: + if (primary_if) + batadv_hardif_free_ref(primary_if); + return NOTIFY_DONE; +} + +/* This function returns true if the interface represented by ifindex is a + * 802.11 wireless device + */ +bool batadv_is_wifi_iface(int ifindex) +{ + struct net_device *net_device = NULL; + bool ret = false; + + if (ifindex == BATADV_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 batadv_hard_if_notifier = { + .notifier_call = batadv_hard_if_event, +}; 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