net: Add batman-adv meshing protocol
B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
wireless. See http://www.open-mesh.org/ for more information and user space
tools.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
new file mode 100644
index 0000000..4f95777
--- /dev/null
+++ b/net/batman-adv/hard-interface.c
@@ -0,0 +1,651 @@
+/*
+ * 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,
+};