net/batman-adv/main.c - kernel/msm-4.9 - Gitiles

 /* 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 <linux/crc32c.h>
 #include <linux/highmem.h>
 #include "main.h"
 #include "sysfs.h"
 #include "debugfs.h"
 #include "routing.h"
 #include "send.h"
 #include "originator.h"
 #include "soft-interface.h"
 #include "icmp_socket.h"
 #include "translation-table.h"
 #include "hard-interface.h"
 #include "gateway_client.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
 #include "vis.h"
 #include "hash.h"
 #include "bat_algo.h"


 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  * list traversals just rcu-locked
  */
 struct list_head batadv_hardif_list;
 static int (*batadv_rx_handler[256])(struct sk_buff *,
 				     struct batadv_hard_iface *);
 char batadv_routing_algo[20] = "BATMAN_IV";
 static struct hlist_head batadv_algo_list;

 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

 struct workqueue_struct *batadv_event_workqueue;

 static void batadv_recv_handler_init(void);

 static int __init batadv_init(void)
 {
 	INIT_LIST_HEAD(&batadv_hardif_list);
 	INIT_HLIST_HEAD(&batadv_algo_list);

 	batadv_recv_handler_init();

 	batadv_iv_init();

 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");

 	if (!batadv_event_workqueue)
 		return -ENOMEM;

 	batadv_socket_init();
 	batadv_debugfs_init();

 	register_netdevice_notifier(&batadv_hard_if_notifier);

 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);

 	return 0;
 }

 static void __exit batadv_exit(void)
 {
 	batadv_debugfs_destroy();
 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
 	batadv_hardif_remove_interfaces();

 	flush_workqueue(batadv_event_workqueue);
 	destroy_workqueue(batadv_event_workqueue);
 	batadv_event_workqueue = NULL;

 	rcu_barrier();
 }

 int batadv_mesh_init(struct net_device *soft_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 	int ret;

 	spin_lock_init(&bat_priv->forw_bat_list_lock);
 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
 	spin_lock_init(&bat_priv->tt.changes_list_lock);
 	spin_lock_init(&bat_priv->tt.req_list_lock);
 	spin_lock_init(&bat_priv->tt.roam_list_lock);
 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
 	spin_lock_init(&bat_priv->gw.list_lock);
 	spin_lock_init(&bat_priv->vis.hash_lock);
 	spin_lock_init(&bat_priv->vis.list_lock);

 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 	INIT_HLIST_HEAD(&bat_priv->gw.list);
 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 	INIT_LIST_HEAD(&bat_priv->tt.req_list);
 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);

 	ret = batadv_originator_init(bat_priv);
 	if (ret < 0)
 		goto err;

 	ret = batadv_tt_init(bat_priv);
 	if (ret < 0)
 		goto err;

 	batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 			    BATADV_NULL_IFINDEX);

 	ret = batadv_vis_init(bat_priv);
 	if (ret < 0)
 		goto err;

 	ret = batadv_bla_init(bat_priv);
 	if (ret < 0)
 		goto err;

 	ret = batadv_dat_init(bat_priv);
 	if (ret < 0)
 		goto err;

 	atomic_set(&bat_priv->gw.reselect, 0);
 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);

 	return 0;

 err:
 	batadv_mesh_free(soft_iface);
 	return ret;
 }

 void batadv_mesh_free(struct net_device *soft_iface)
 {
 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);

 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);

 	batadv_purge_outstanding_packets(bat_priv, NULL);

 	batadv_vis_quit(bat_priv);

 	batadv_gw_node_purge(bat_priv);
 	batadv_originator_free(bat_priv);

 	batadv_tt_free(bat_priv);

 	batadv_bla_free(bat_priv);

 	batadv_dat_free(bat_priv);

 	free_percpu(bat_priv->bat_counters);

 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 }

 int batadv_is_my_mac(const uint8_t *addr)
 {
 	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)
 			continue;

 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 			rcu_read_unlock();
 			return 1;
 		}
 	}
 	rcu_read_unlock();
 	return 0;
 }

 /**
  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
  *  function that requires the primary interface
  * @seq: debugfs table seq_file struct
  *
  * Returns primary interface if found or NULL otherwise.
  */
 struct batadv_hard_iface *
 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 {
 	struct net_device *net_dev = (struct net_device *)seq->private;
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
 	struct batadv_hard_iface *primary_if;

 	primary_if = batadv_primary_if_get_selected(bat_priv);

 	if (!primary_if) {
 		seq_printf(seq,
 			   "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 			   net_dev->name);
 		goto out;
 	}

 	if (primary_if->if_status == BATADV_IF_ACTIVE)
 		goto out;

 	seq_printf(seq,
 		   "BATMAN mesh %s disabled - primary interface not active\n",
 		   net_dev->name);
 	batadv_hardif_free_ref(primary_if);
 	primary_if = NULL;

 out:
 	return primary_if;
 }

 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 					struct batadv_hard_iface *recv_if)
 {
 	return NET_RX_DROP;
 }

 /* incoming packets with the batman ethertype received on any active hard
  * interface
  */
 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 			   struct packet_type *ptype,
 			   struct net_device *orig_dev)
 {
 	struct batadv_priv *bat_priv;
 	struct batadv_ogm_packet *batadv_ogm_packet;
 	struct batadv_hard_iface *hard_iface;
 	uint8_t idx;
 	int ret;

 	hard_iface = container_of(ptype, struct batadv_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 != ETH_HLEN || !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) != BATADV_MESH_ACTIVE)
 		goto err_free;

 	/* discard frames on not active interfaces */
 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
 		goto err_free;

 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;

 	if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Drop packet: incompatible batman version (%i)\n",
 			   batadv_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.
 	 */
 	idx = batadv_ogm_packet->header.packet_type;
 	ret = (*batadv_rx_handler[idx])(skb, hard_iface);

 	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;
 }

 static void batadv_recv_handler_init(void)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;

 	/* batman icmp packet */
 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 	/* unicast with 4 addresses packet */
 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 	/* unicast packet */
 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 	/* fragmented unicast packet */
 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 	/* broadcast packet */
 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 	/* vis packet */
 	batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 	/* Translation table query (request or response) */
 	batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 	/* Roaming advertisement */
 	batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 }

 int
 batadv_recv_handler_register(uint8_t packet_type,
 			     int (*recv_handler)(struct sk_buff *,
 						 struct batadv_hard_iface *))
 {
 	if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 		return -EBUSY;

 	batadv_rx_handler[packet_type] = recv_handler;
 	return 0;
 }

 void batadv_recv_handler_unregister(uint8_t packet_type)
 {
 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 }

 static struct batadv_algo_ops *batadv_algo_get(char *name)
 {
 	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 	struct hlist_node *node;

 	hlist_for_each_entry(bat_algo_ops_tmp, node, &batadv_algo_list, list) {
 		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 			continue;

 		bat_algo_ops = bat_algo_ops_tmp;
 		break;
 	}

 	return bat_algo_ops;
 }

 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 {
 	struct batadv_algo_ops *bat_algo_ops_tmp;
 	int ret;

 	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 	if (bat_algo_ops_tmp) {
 		pr_info("Trying to register already registered routing algorithm: %s\n",
 			bat_algo_ops->name);
 		ret = -EEXIST;
 		goto out;
 	}

 	/* all algorithms must implement all ops (for now) */
 	if (!bat_algo_ops->bat_iface_enable ||
 	    !bat_algo_ops->bat_iface_disable ||
 	    !bat_algo_ops->bat_iface_update_mac ||
 	    !bat_algo_ops->bat_primary_iface_set ||
 	    !bat_algo_ops->bat_ogm_schedule ||
 	    !bat_algo_ops->bat_ogm_emit) {
 		pr_info("Routing algo '%s' does not implement required ops\n",
 			bat_algo_ops->name);
 		ret = -EINVAL;
 		goto out;
 	}

 	INIT_HLIST_NODE(&bat_algo_ops->list);
 	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 	ret = 0;

 out:
 	return ret;
 }

 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 {
 	struct batadv_algo_ops *bat_algo_ops;
 	int ret = -EINVAL;

 	bat_algo_ops = batadv_algo_get(name);
 	if (!bat_algo_ops)
 		goto out;

 	bat_priv->bat_algo_ops = bat_algo_ops;
 	ret = 0;

 out:
 	return ret;
 }

 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 {
 	struct batadv_algo_ops *bat_algo_ops;
 	struct hlist_node *node;

 	seq_printf(seq, "Available routing algorithms:\n");

 	hlist_for_each_entry(bat_algo_ops, node, &batadv_algo_list, list) {
 		seq_printf(seq, "%s\n", bat_algo_ops->name);
 	}

 	return 0;
 }

 /**
  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
  *  the header
  * @skb: skb pointing to fragmented socket buffers
  * @payload_ptr: Pointer to position inside the head buffer of the skb
  *  marking the start of the data to be CRC'ed
  *
  * payload_ptr must always point to an address in the skb head buffer and not to
  * a fragment.
  */
 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 {
 	u32 crc = 0;
 	unsigned int from;
 	unsigned int to = skb->len;
 	struct skb_seq_state st;
 	const u8 *data;
 	unsigned int len;
 	unsigned int consumed = 0;

 	from = (unsigned int)(payload_ptr - skb->data);

 	skb_prepare_seq_read(skb, from, to, &st);
 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 		crc = crc32c(crc, data, len);
 		consumed += len;
 	}
 	skb_abort_seq_read(&st);

 	return htonl(crc);
 }

 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 {
 	struct batadv_algo_ops *bat_algo_ops;
 	char *algo_name = (char *)val;
 	size_t name_len = strlen(algo_name);

 	if (algo_name[name_len - 1] == '\n')
 		algo_name[name_len - 1] = '\0';

 	bat_algo_ops = batadv_algo_get(algo_name);
 	if (!bat_algo_ops) {
 		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 		return -EINVAL;
 	}

 	return param_set_copystring(algo_name, kp);
 }

 static const struct kernel_param_ops batadv_param_ops_ra = {
 	.set = batadv_param_set_ra,
 	.get = param_get_string,
 };

 static struct kparam_string batadv_param_string_ra = {
 	.maxlen = sizeof(batadv_routing_algo),
 	.string = batadv_routing_algo,
 };

 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 		0644);
 module_init(batadv_init);
 module_exit(batadv_exit);

 MODULE_LICENSE("GPL");

 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 MODULE_VERSION(BATADV_SOURCE_VERSION);
	/* 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 <linux/crc32c.h>
	#include <linux/highmem.h>
	#include "main.h"
	#include "sysfs.h"
	#include "debugfs.h"
	#include "routing.h"
	#include "send.h"
	#include "originator.h"
	#include "soft-interface.h"
	#include "icmp_socket.h"
	#include "translation-table.h"
	#include "hard-interface.h"
	#include "gateway_client.h"
	#include "bridge_loop_avoidance.h"
	#include "distributed-arp-table.h"
	#include "vis.h"
	#include "hash.h"
	#include "bat_algo.h"


	/* List manipulations on hardif_list have to be rtnl_lock()'ed,
	* list traversals just rcu-locked
	*/
	struct list_head batadv_hardif_list;
	static int (batadv_rx_handler[256])(struct sk_buff ,
	struct batadv_hard_iface *);
	char batadv_routing_algo[20] = "BATMAN_IV";
	static struct hlist_head batadv_algo_list;

	unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

	struct workqueue_struct *batadv_event_workqueue;

	static void batadv_recv_handler_init(void);

	static int __init batadv_init(void)
	{
	INIT_LIST_HEAD(&batadv_hardif_list);
	INIT_HLIST_HEAD(&batadv_algo_list);

	batadv_recv_handler_init();

	batadv_iv_init();

	batadv_event_workqueue = create_singlethread_workqueue("bat_events");

	if (!batadv_event_workqueue)
	return -ENOMEM;

	batadv_socket_init();
	batadv_debugfs_init();

	register_netdevice_notifier(&batadv_hard_if_notifier);

	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
	BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);

	return 0;
	}

	static void __exit batadv_exit(void)
	{
	batadv_debugfs_destroy();
	unregister_netdevice_notifier(&batadv_hard_if_notifier);
	batadv_hardif_remove_interfaces();

	flush_workqueue(batadv_event_workqueue);
	destroy_workqueue(batadv_event_workqueue);
	batadv_event_workqueue = NULL;

	rcu_barrier();
	}

	int batadv_mesh_init(struct net_device *soft_iface)
	{
	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
	int ret;

	spin_lock_init(&bat_priv->forw_bat_list_lock);
	spin_lock_init(&bat_priv->forw_bcast_list_lock);
	spin_lock_init(&bat_priv->tt.changes_list_lock);
	spin_lock_init(&bat_priv->tt.req_list_lock);
	spin_lock_init(&bat_priv->tt.roam_list_lock);
	spin_lock_init(&bat_priv->tt.last_changeset_lock);
	spin_lock_init(&bat_priv->gw.list_lock);
	spin_lock_init(&bat_priv->vis.hash_lock);
	spin_lock_init(&bat_priv->vis.list_lock);

	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
	INIT_HLIST_HEAD(&bat_priv->gw.list);
	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
	INIT_LIST_HEAD(&bat_priv->tt.req_list);
	INIT_LIST_HEAD(&bat_priv->tt.roam_list);

	ret = batadv_originator_init(bat_priv);
	if (ret < 0)
	goto err;

	ret = batadv_tt_init(bat_priv);
	if (ret < 0)
	goto err;

	batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
	BATADV_NULL_IFINDEX);

	ret = batadv_vis_init(bat_priv);
	if (ret < 0)
	goto err;

	ret = batadv_bla_init(bat_priv);
	if (ret < 0)
	goto err;

	ret = batadv_dat_init(bat_priv);
	if (ret < 0)
	goto err;

	atomic_set(&bat_priv->gw.reselect, 0);
	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);

	return 0;

	err:
	batadv_mesh_free(soft_iface);
	return ret;
	}

	void batadv_mesh_free(struct net_device *soft_iface)
	{
	struct batadv_priv *bat_priv = netdev_priv(soft_iface);

	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);

	batadv_purge_outstanding_packets(bat_priv, NULL);

	batadv_vis_quit(bat_priv);

	batadv_gw_node_purge(bat_priv);
	batadv_originator_free(bat_priv);

	batadv_tt_free(bat_priv);

	batadv_bla_free(bat_priv);

	batadv_dat_free(bat_priv);

	free_percpu(bat_priv->bat_counters);

	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
	}

	int batadv_is_my_mac(const uint8_t *addr)
	{
	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)
	continue;

	if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
	rcu_read_unlock();
	return 1;
	}
	}
	rcu_read_unlock();
	return 0;
	}

	/**
	* batadv_seq_print_text_primary_if_get - called from debugfs table printing
	* function that requires the primary interface
	* @seq: debugfs table seq_file struct
	*
	* Returns primary interface if found or NULL otherwise.
	*/
	struct batadv_hard_iface *
	batadv_seq_print_text_primary_if_get(struct seq_file *seq)
	{
	struct net_device net_dev = (struct net_device )seq->private;
	struct batadv_priv *bat_priv = netdev_priv(net_dev);
	struct batadv_hard_iface *primary_if;

	primary_if = batadv_primary_if_get_selected(bat_priv);

	if (!primary_if) {
	seq_printf(seq,
	"BATMAN mesh %s disabled - please specify interfaces to enable it\n",
	net_dev->name);
	goto out;
	}

	if (primary_if->if_status == BATADV_IF_ACTIVE)
	goto out;

	seq_printf(seq,
	"BATMAN mesh %s disabled - primary interface not active\n",
	net_dev->name);
	batadv_hardif_free_ref(primary_if);
	primary_if = NULL;

	out:
	return primary_if;
	}

	static int batadv_recv_unhandled_packet(struct sk_buff *skb,
	struct batadv_hard_iface *recv_if)
	{
	return NET_RX_DROP;
	}

	/* incoming packets with the batman ethertype received on any active hard
	* interface
	*/
	int batadv_batman_skb_recv(struct sk_buff skb, struct net_device dev,
	struct packet_type *ptype,
	struct net_device *orig_dev)
	{
	struct batadv_priv *bat_priv;
	struct batadv_ogm_packet *batadv_ogm_packet;
	struct batadv_hard_iface *hard_iface;
	uint8_t idx;
	int ret;

	hard_iface = container_of(ptype, struct batadv_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 != ETH_HLEN \|\| !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) != BATADV_MESH_ACTIVE)
	goto err_free;

	/* discard frames on not active interfaces */
	if (hard_iface->if_status != BATADV_IF_ACTIVE)
	goto err_free;

	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;

	if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"Drop packet: incompatible batman version (%i)\n",
	batadv_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.
	*/
	idx = batadv_ogm_packet->header.packet_type;
	ret = (*batadv_rx_handler[idx])(skb, hard_iface);

	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;
	}

	static void batadv_recv_handler_init(void)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
	batadv_rx_handler[i] = batadv_recv_unhandled_packet;

	/* batman icmp packet */
	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
	/* unicast with 4 addresses packet */
	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
	/* unicast packet */
	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
	/* fragmented unicast packet */
	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
	/* broadcast packet */
	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
	/* vis packet */
	batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
	/* Translation table query (request or response) */
	batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
	/* Roaming advertisement */
	batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
	}

	int
	batadv_recv_handler_register(uint8_t packet_type,
	int (recv_handler)(struct sk_buff ,
	struct batadv_hard_iface *))
	{
	if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
	return -EBUSY;

	batadv_rx_handler[packet_type] = recv_handler;
	return 0;
	}

	void batadv_recv_handler_unregister(uint8_t packet_type)
	{
	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
	}

	static struct batadv_algo_ops batadv_algo_get(char name)
	{
	struct batadv_algo_ops bat_algo_ops = NULL, bat_algo_ops_tmp;
	struct hlist_node *node;

	hlist_for_each_entry(bat_algo_ops_tmp, node, &batadv_algo_list, list) {
	if (strcmp(bat_algo_ops_tmp->name, name) != 0)
	continue;

	bat_algo_ops = bat_algo_ops_tmp;
	break;
	}

	return bat_algo_ops;
	}

	int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
	{
	struct batadv_algo_ops *bat_algo_ops_tmp;
	int ret;

	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
	if (bat_algo_ops_tmp) {
	pr_info("Trying to register already registered routing algorithm: %s\n",
	bat_algo_ops->name);
	ret = -EEXIST;
	goto out;
	}

	/* all algorithms must implement all ops (for now) */
	if (!bat_algo_ops->bat_iface_enable \|\|
	!bat_algo_ops->bat_iface_disable \|\|
	!bat_algo_ops->bat_iface_update_mac \|\|
	!bat_algo_ops->bat_primary_iface_set \|\|
	!bat_algo_ops->bat_ogm_schedule \|\|
	!bat_algo_ops->bat_ogm_emit) {
	pr_info("Routing algo '%s' does not implement required ops\n",
	bat_algo_ops->name);
	ret = -EINVAL;
	goto out;
	}

	INIT_HLIST_NODE(&bat_algo_ops->list);
	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
	ret = 0;

	out:
	return ret;
	}

	int batadv_algo_select(struct batadv_priv bat_priv, char name)
	{
	struct batadv_algo_ops *bat_algo_ops;
	int ret = -EINVAL;

	bat_algo_ops = batadv_algo_get(name);
	if (!bat_algo_ops)
	goto out;

	bat_priv->bat_algo_ops = bat_algo_ops;
	ret = 0;

	out:
	return ret;
	}

	int batadv_algo_seq_print_text(struct seq_file seq, void offset)
	{
	struct batadv_algo_ops *bat_algo_ops;
	struct hlist_node *node;

	seq_printf(seq, "Available routing algorithms:\n");

	hlist_for_each_entry(bat_algo_ops, node, &batadv_algo_list, list) {
	seq_printf(seq, "%s\n", bat_algo_ops->name);
	}

	return 0;
	}

	/**
	* batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
	* the header
	* @skb: skb pointing to fragmented socket buffers
	* @payload_ptr: Pointer to position inside the head buffer of the skb
	* marking the start of the data to be CRC'ed
	*
	* payload_ptr must always point to an address in the skb head buffer and not to
	* a fragment.
	*/
	__be32 batadv_skb_crc32(struct sk_buff skb, u8 payload_ptr)
	{
	u32 crc = 0;
	unsigned int from;
	unsigned int to = skb->len;
	struct skb_seq_state st;
	const u8 *data;
	unsigned int len;
	unsigned int consumed = 0;

	from = (unsigned int)(payload_ptr - skb->data);

	skb_prepare_seq_read(skb, from, to, &st);
	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
	crc = crc32c(crc, data, len);
	consumed += len;
	}
	skb_abort_seq_read(&st);

	return htonl(crc);
	}

	static int batadv_param_set_ra(const char val, const struct kernel_param kp)
	{
	struct batadv_algo_ops *bat_algo_ops;
	char algo_name = (char )val;
	size_t name_len = strlen(algo_name);

	if (algo_name[name_len - 1] == '\n')
	algo_name[name_len - 1] = '\0';

	bat_algo_ops = batadv_algo_get(algo_name);
	if (!bat_algo_ops) {
	pr_err("Routing algorithm '%s' is not supported\n", algo_name);
	return -EINVAL;
	}

	return param_set_copystring(algo_name, kp);
	}

	static const struct kernel_param_ops batadv_param_ops_ra = {
	.set = batadv_param_set_ra,
	.get = param_get_string,
	};

	static struct kparam_string batadv_param_string_ra = {
	.maxlen = sizeof(batadv_routing_algo),
	.string = batadv_routing_algo,
	};

	module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
	0644);
	module_init(batadv_init);
	module_exit(batadv_exit);

	MODULE_LICENSE("GPL");

	MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
	MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
	MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
	MODULE_VERSION(BATADV_SOURCE_VERSION);