/* Copyright (C) 2007-2016 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, see . */ #include "hard-interface.h" #include "main.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "bridge_loop_avoidance.h" #include "debugfs.h" #include "distributed-arp-table.h" #include "gateway_client.h" #include "originator.h" #include "packet.h" #include "send.h" #include "soft-interface.h" #include "sysfs.h" #include "translation-table.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. * * Return: 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 (dev_get_iflink(net_dev) == 0 || dev_get_iflink(net_dev) == net_dev->ifindex) return false; /* recurse over the parent device */ parent_dev = __dev_get_by_index(&init_net, dev_get_iflink(net_dev)); /* 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); 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; } /** * batadv_is_wifi_netdev - check if the given net_device struct is a wifi * interface * @net_device: the device to check * * Return: true if the net device is a 802.11 wireless device, false otherwise. */ bool batadv_is_wifi_netdev(struct net_device *net_device) { if (!net_device) return false; #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) return true; #endif /* cfg80211 drivers have to set ieee80211_ptr */ if (net_device->ieee80211_ptr) return true; return false; } 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_hard_iface *primary_if; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; batadv_dat_init_own_addr(bat_priv, primary_if); 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(); } /** * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom * @soft_iface: netdev struct of the mesh interface */ static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface) { const struct batadv_hard_iface *hard_iface; unsigned short lower_header_len = ETH_HLEN; unsigned short lower_headroom = 0; unsigned short lower_tailroom = 0; unsigned short needed_headroom; rcu_read_lock(); list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { if (hard_iface->if_status == BATADV_IF_NOT_IN_USE) continue; if (hard_iface->soft_iface != soft_iface) continue; lower_header_len = max_t(unsigned short, lower_header_len, hard_iface->net_dev->hard_header_len); lower_headroom = max_t(unsigned short, lower_headroom, hard_iface->net_dev->needed_headroom); lower_tailroom = max_t(unsigned short, lower_tailroom, hard_iface->net_dev->needed_tailroom); } rcu_read_unlock(); needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN); needed_headroom += batadv_max_header_len(); soft_iface->needed_headroom = needed_headroom; soft_iface->needed_tailroom = lower_tailroom; } int batadv_hardif_min_mtu(struct net_device *soft_iface) { struct batadv_priv *bat_priv = netdev_priv(soft_iface); const struct batadv_hard_iface *hard_iface; int min_mtu = INT_MAX; 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, min_mtu); } rcu_read_unlock(); if (atomic_read(&bat_priv->fragmentation) == 0) goto out; /* with fragmentation enabled the maximum size of internally generated * packets such as translation table exchanges or tvlv containers, etc * has to be calculated */ min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE); min_mtu -= sizeof(struct batadv_frag_packet); min_mtu *= BATADV_FRAG_MAX_FRAGMENTS; out: /* report to the other components the maximum amount of bytes that * batman-adv can send over the wire (without considering the payload * overhead). For example, this value is used by TT to compute the * maximum local table table size */ atomic_set(&bat_priv->packet_size_max, min_mtu); /* the real soft-interface MTU is computed by removing the payload * overhead from the maximum amount of bytes that was just computed. * * However batman-adv does not support MTUs bigger than ETH_DATA_LEN */ return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN); } /* adjusts the MTU if a new interface with a smaller MTU appeared. */ void batadv_update_min_mtu(struct net_device *soft_iface) { soft_iface->mtu = batadv_hardif_min_mtu(soft_iface); /* Check if the local translate table should be cleaned up to match a * new (and smaller) MTU. */ batadv_tt_local_resize_to_mtu(soft_iface); } 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 = htons(ETH_P_BATMAN); int max_header_len = batadv_max_header_len(); 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, NULL, NULL); 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); 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 + max_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 %i would solve the problem.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, ETH_DATA_LEN + max_header_len); if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu < ETH_DATA_LEN + max_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 %i.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, ETH_DATA_LEN + max_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); batadv_hardif_recalc_extra_skbroom(soft_iface); /* 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); netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface); batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface); /* nobody uses this interface anymore */ if (!bat_priv->num_ifaces) { batadv_gw_check_client_stop(bat_priv); if (autodel == BATADV_IF_CLEANUP_AUTO) batadv_softif_destroy_sysfs(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_debugfs_del_hardif(hard_iface); 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 = kzalloc(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; ret = batadv_debugfs_add_hardif(hard_iface); if (ret) goto free_sysfs; INIT_LIST_HEAD(&hard_iface->list); INIT_HLIST_HEAD(&hard_iface->neigh_list); INIT_WORK(&hard_iface->cleanup_work, batadv_hardif_remove_interface_finish); spin_lock_init(&hard_iface->neigh_list_lock); hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT; if (batadv_is_wifi_netdev(net_dev)) hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; /* 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); return hard_iface; free_sysfs: batadv_sysfs_del_hardif(&hard_iface->hardif_obj); 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 = netdev_notifier_info_to_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); bat_priv = netdev_priv(net_dev); batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS); return NOTIFY_DONE; } hard_iface = batadv_hardif_get_by_netdev(net_dev); if (!hard_iface && (event == NETDEV_REGISTER || event == NETDEV_POST_TYPE_CHANGE)) 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: case NETDEV_PRE_TYPE_CHANGE: 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; } struct notifier_block batadv_hard_if_notifier = { .notifier_call = batadv_hard_if_event, };