diff options
Diffstat (limited to 'net/batman-adv/hard-interface.c')
| -rw-r--r-- | net/batman-adv/hard-interface.c | 688 |
1 files changed, 688 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..37789770 --- /dev/null +++ b/net/batman-adv/hard-interface.c @@ -0,0 +1,688 @@ +/* + * 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, +}; |