net/batman-adv/main.h - kernel/msm-4.19 - Gitiles

 /* Copyright (C) 2007-2017  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 <http://www.gnu.org/licenses/>.
  */

 #ifndef _NET_BATMAN_ADV_MAIN_H_
 #define _NET_BATMAN_ADV_MAIN_H_

 #define BATADV_DRIVER_AUTHOR "Marek Lindner <mareklindner@neomailbox.ch>, " \
 			     "Simon Wunderlich <sw@simonwunderlich.de>"
 #define BATADV_DRIVER_DESC   "B.A.T.M.A.N. advanced"
 #define BATADV_DRIVER_DEVICE "batman-adv"

 #ifndef BATADV_SOURCE_VERSION
 #define BATADV_SOURCE_VERSION "2017.0"
 #endif

 /* B.A.T.M.A.N. parameters */

 #define BATADV_TQ_MAX_VALUE 255
 #define BATADV_THROUGHPUT_MAX_VALUE 0xFFFFFFFF
 #define BATADV_JITTER 20

 /* Time To Live of broadcast messages */
 #define BATADV_TTL 50

 /* maximum sequence number age of broadcast messages */
 #define BATADV_BCAST_MAX_AGE 64

 /* purge originators after time in seconds if no valid packet comes in
  * -> TODO: check influence on BATADV_TQ_LOCAL_WINDOW_SIZE
  */
 #define BATADV_PURGE_TIMEOUT 200000 /* 200 seconds */
 #define BATADV_TT_LOCAL_TIMEOUT 600000 /* in milliseconds */
 #define BATADV_TT_CLIENT_ROAM_TIMEOUT 600000 /* in milliseconds */
 #define BATADV_TT_CLIENT_TEMP_TIMEOUT 600000 /* in milliseconds */
 #define BATADV_TT_WORK_PERIOD 5000 /* 5 seconds */
 #define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */
 #define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */
 #define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */
 /* sliding packet range of received originator messages in sequence numbers
  * (should be a multiple of our word size)
  */
 #define BATADV_TQ_LOCAL_WINDOW_SIZE 64
 /* milliseconds we have to keep pending tt_req */
 #define BATADV_TT_REQUEST_TIMEOUT 3000

 #define BATADV_TQ_GLOBAL_WINDOW_SIZE 5
 #define BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM 1
 #define BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM 1
 #define BATADV_TQ_TOTAL_BIDRECT_LIMIT 1

 /* B.A.T.M.A.N. V */
 #define BATADV_THROUGHPUT_DEFAULT_VALUE 10 /* 1 Mbps */
 #define BATADV_ELP_PROBES_PER_NODE 2
 #define BATADV_ELP_MIN_PROBE_SIZE 200 /* bytes */
 #define BATADV_ELP_PROBE_MAX_TX_DIFF 100 /* milliseconds */
 #define BATADV_ELP_MAX_AGE 64
 #define BATADV_OGM_MAX_ORIGDIFF 5
 #define BATADV_OGM_MAX_AGE 64

 /* number of OGMs sent with the last tt diff */
 #define BATADV_TT_OGM_APPEND_MAX 3

 /* Time in which a client can roam at most ROAMING_MAX_COUNT times in
  * milliseconds
  */
 #define BATADV_ROAMING_MAX_TIME 20000
 #define BATADV_ROAMING_MAX_COUNT 5

 #define BATADV_NO_FLAGS 0

 #define BATADV_NULL_IFINDEX 0 /* dummy ifindex used to avoid iface checks */

 #define BATADV_NO_MARK 0

 /* default interface for multi interface operation. The default interface is
  * used for communication which originated locally (i.e. is not forwarded)
  * or where special forwarding is not desired/necessary.
  */
 #define BATADV_IF_DEFAULT	((struct batadv_hard_iface *)NULL)

 #define BATADV_NUM_WORDS BITS_TO_LONGS(BATADV_TQ_LOCAL_WINDOW_SIZE)

 #define BATADV_LOG_BUF_LEN 8192	  /* has to be a power of 2 */

 /* number of packets to send for broadcasts on different interface types */
 #define BATADV_NUM_BCASTS_DEFAULT 1
 #define BATADV_NUM_BCASTS_WIRELESS 3
 #define BATADV_NUM_BCASTS_MAX 3

 /* length of the single packet used by the TP meter */
 #define BATADV_TP_PACKET_LEN ETH_DATA_LEN

 /* msecs after which an ARP_REQUEST is sent in broadcast as fallback */
 #define ARP_REQ_DELAY 250
 /* numbers of originator to contact for any PUT/GET DHT operation */
 #define BATADV_DAT_CANDIDATES_NUM 3

 /* BATADV_TQ_SIMILARITY_THRESHOLD - TQ points that a secondary metric can differ
  * at most from the primary one in order to be still considered acceptable
  */
 #define BATADV_TQ_SIMILARITY_THRESHOLD 50

 /* should not be bigger than 512 bytes or change the size of
  * forw_packet->direct_link_flags
  */
 #define BATADV_MAX_AGGREGATION_BYTES 512
 #define BATADV_MAX_AGGREGATION_MS 100

 #define BATADV_BLA_PERIOD_LENGTH	10000	/* 10 seconds */
 #define BATADV_BLA_BACKBONE_TIMEOUT	(BATADV_BLA_PERIOD_LENGTH * 6)
 #define BATADV_BLA_CLAIM_TIMEOUT	(BATADV_BLA_PERIOD_LENGTH * 10)
 #define BATADV_BLA_WAIT_PERIODS		3
 #define BATADV_BLA_LOOPDETECT_PERIODS	6
 #define BATADV_BLA_LOOPDETECT_TIMEOUT	3000	/* 3 seconds */

 #define BATADV_DUPLIST_SIZE		16
 #define BATADV_DUPLIST_TIMEOUT		500	/* 500 ms */
 /* don't reset again within 30 seconds */
 #define BATADV_RESET_PROTECTION_MS 30000
 #define BATADV_EXPECTED_SEQNO_RANGE	65536

 #define BATADV_NC_NODE_TIMEOUT 10000 /* Milliseconds */

 /**
  * BATADV_TP_MAX_NUM - maximum number of simultaneously active tp sessions
  */
 #define BATADV_TP_MAX_NUM 5

 enum batadv_mesh_state {
 	BATADV_MESH_INACTIVE,
 	BATADV_MESH_ACTIVE,
 	BATADV_MESH_DEACTIVATING,
 };

 #define BATADV_BCAST_QUEUE_LEN		256
 #define BATADV_BATMAN_QUEUE_LEN	256

 enum batadv_uev_action {
 	BATADV_UEV_ADD = 0,
 	BATADV_UEV_DEL,
 	BATADV_UEV_CHANGE,
 	BATADV_UEV_LOOPDETECT,
 };

 enum batadv_uev_type {
 	BATADV_UEV_GW = 0,
 	BATADV_UEV_BLA,
 };

 #define BATADV_GW_THRESHOLD	50

 /* Number of fragment chains for each orig_node */
 #define BATADV_FRAG_BUFFER_COUNT 8
 /* Maximum number of fragments for one packet */
 #define BATADV_FRAG_MAX_FRAGMENTS 16
 /* Maxumim size of each fragment */
 #define BATADV_FRAG_MAX_FRAG_SIZE 1400
 /* Time to keep fragments while waiting for rest of the fragments */
 #define BATADV_FRAG_TIMEOUT 10000

 #define BATADV_DAT_CANDIDATE_NOT_FOUND	0
 #define BATADV_DAT_CANDIDATE_ORIG	1

 /* Debug Messages */
 #ifdef pr_fmt
 #undef pr_fmt
 #endif
 /* Append 'batman-adv: ' before kernel messages */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 /* Kernel headers */

 #include <linux/bitops.h> /* for packet.h */
 #include <linux/compiler.h>
 #include <linux/etherdevice.h>
 #include <linux/if_ether.h> /* for packet.h */
 #include <linux/if_vlan.h>
 #include <linux/jiffies.h>
 #include <linux/percpu.h>
 #include <linux/types.h>

 #include "types.h"

 struct net_device;
 struct packet_type;
 struct seq_file;
 struct sk_buff;

 #define BATADV_PRINT_VID(vid) (((vid) & BATADV_VLAN_HAS_TAG) ? \
 			       (int)((vid) & VLAN_VID_MASK) : -1)

 extern struct list_head batadv_hardif_list;

 extern unsigned char batadv_broadcast_addr[];
 extern struct workqueue_struct *batadv_event_workqueue;

 int batadv_mesh_init(struct net_device *soft_iface);
 void batadv_mesh_free(struct net_device *soft_iface);
 bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr);
 struct batadv_hard_iface *
 batadv_seq_print_text_primary_if_get(struct seq_file *seq);
 int batadv_max_header_len(void);
 void batadv_skb_set_priority(struct sk_buff *skb, int offset);
 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 			   struct packet_type *ptype,
 			   struct net_device *orig_dev);
 int
 batadv_recv_handler_register(u8 packet_type,
 			     int (*recv_handler)(struct sk_buff *,
 						 struct batadv_hard_iface *));
 void batadv_recv_handler_unregister(u8 packet_type);
 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);

 /**
  * batadv_compare_eth - Compare two not u16 aligned Ethernet addresses
  * @data1: Pointer to a six-byte array containing the Ethernet address
  * @data2: Pointer other six-byte array containing the Ethernet address
  *
  * note: can't use ether_addr_equal() as it requires aligned memory
  *
  * Return: true if they are the same ethernet addr
  */
 static inline bool batadv_compare_eth(const void *data1, const void *data2)
 {
 	return ether_addr_equal_unaligned(data1, data2);
 }

 /**
  * batadv_has_timed_out - compares current time (jiffies) and timestamp +
  *  timeout
  * @timestamp:		base value to compare with (in jiffies)
  * @timeout:		added to base value before comparing (in milliseconds)
  *
  * Return: true if current time is after timestamp + timeout
  */
 static inline bool batadv_has_timed_out(unsigned long timestamp,
 					unsigned int timeout)
 {
 	return time_is_before_jiffies(timestamp + msecs_to_jiffies(timeout));
 }

 #define batadv_atomic_dec_not_zero(v)	atomic_add_unless((v), -1, 0)

 /* Returns the smallest signed integer in two's complement with the sizeof x */
 #define batadv_smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))

 /* Checks if a sequence number x is a predecessor/successor of y.
  * they handle overflows/underflows and can correctly check for a
  * predecessor/successor unless the variable sequence number has grown by
  * more then 2**(bitwidth(x)-1)-1.
  * This means that for a u8 with the maximum value 255, it would think:
  *  - when adding nothing - it is neither a predecessor nor a successor
  *  - before adding more than 127 to the starting value - it is a predecessor,
  *  - when adding 128 - it is neither a predecessor nor a successor,
  *  - after adding more than 127 to the starting value - it is a successor
  */
 #define batadv_seq_before(x, y) ({typeof(x)_d1 = (x); \
 				 typeof(y)_d2 = (y); \
 				 typeof(x)_dummy = (_d1 - _d2); \
 				 (void)(&_d1 == &_d2); \
 				 _dummy > batadv_smallest_signed_int(_dummy); })
 #define batadv_seq_after(x, y) batadv_seq_before(y, x)

 /* Stop preemption on local cpu while incrementing the counter */
 static inline void batadv_add_counter(struct batadv_priv *bat_priv, size_t idx,
 				      size_t count)
 {
 	this_cpu_add(bat_priv->bat_counters[idx], count);
 }

 #define batadv_inc_counter(b, i) batadv_add_counter(b, i, 1)

 /* Define a macro to reach the control buffer of the skb. The members of the
  * control buffer are defined in struct batadv_skb_cb in types.h.
  * The macro is inspired by the similar macro TCP_SKB_CB() in tcp.h.
  */
 #define BATADV_SKB_CB(__skb)       ((struct batadv_skb_cb *)&((__skb)->cb[0]))

 unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len);
 bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid);

 #endif /* _NET_BATMAN_ADV_MAIN_H_ */
	/* Copyright (C) 2007-2017 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 <http://www.gnu.org/licenses/>.
	*/

	#ifndef _NET_BATMAN_ADV_MAIN_H_
	#define _NET_BATMAN_ADV_MAIN_H_

	#define BATADV_DRIVER_AUTHOR "Marek Lindner <mareklindner@neomailbox.ch>, " \
	"Simon Wunderlich <sw@simonwunderlich.de>"
	#define BATADV_DRIVER_DESC "B.A.T.M.A.N. advanced"
	#define BATADV_DRIVER_DEVICE "batman-adv"

	#ifndef BATADV_SOURCE_VERSION
	#define BATADV_SOURCE_VERSION "2017.0"
	#endif

	/* B.A.T.M.A.N. parameters */

	#define BATADV_TQ_MAX_VALUE 255
	#define BATADV_THROUGHPUT_MAX_VALUE 0xFFFFFFFF
	#define BATADV_JITTER 20

	/* Time To Live of broadcast messages */
	#define BATADV_TTL 50

	/* maximum sequence number age of broadcast messages */
	#define BATADV_BCAST_MAX_AGE 64

	/* purge originators after time in seconds if no valid packet comes in
	* -> TODO: check influence on BATADV_TQ_LOCAL_WINDOW_SIZE
	*/
	#define BATADV_PURGE_TIMEOUT 200000 /* 200 seconds */
	#define BATADV_TT_LOCAL_TIMEOUT 600000 /* in milliseconds */
	#define BATADV_TT_CLIENT_ROAM_TIMEOUT 600000 /* in milliseconds */
	#define BATADV_TT_CLIENT_TEMP_TIMEOUT 600000 /* in milliseconds */
	#define BATADV_TT_WORK_PERIOD 5000 /* 5 seconds */
	#define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */
	#define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */
	#define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */
	/* sliding packet range of received originator messages in sequence numbers
	* (should be a multiple of our word size)
	*/
	#define BATADV_TQ_LOCAL_WINDOW_SIZE 64
	/* milliseconds we have to keep pending tt_req */
	#define BATADV_TT_REQUEST_TIMEOUT 3000

	#define BATADV_TQ_GLOBAL_WINDOW_SIZE 5
	#define BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM 1
	#define BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM 1
	#define BATADV_TQ_TOTAL_BIDRECT_LIMIT 1

	/* B.A.T.M.A.N. V */
	#define BATADV_THROUGHPUT_DEFAULT_VALUE 10 /* 1 Mbps */
	#define BATADV_ELP_PROBES_PER_NODE 2
	#define BATADV_ELP_MIN_PROBE_SIZE 200 /* bytes */
	#define BATADV_ELP_PROBE_MAX_TX_DIFF 100 /* milliseconds */
	#define BATADV_ELP_MAX_AGE 64
	#define BATADV_OGM_MAX_ORIGDIFF 5
	#define BATADV_OGM_MAX_AGE 64

	/* number of OGMs sent with the last tt diff */
	#define BATADV_TT_OGM_APPEND_MAX 3

	/* Time in which a client can roam at most ROAMING_MAX_COUNT times in
	* milliseconds
	*/
	#define BATADV_ROAMING_MAX_TIME 20000
	#define BATADV_ROAMING_MAX_COUNT 5

	#define BATADV_NO_FLAGS 0

	#define BATADV_NULL_IFINDEX 0 /* dummy ifindex used to avoid iface checks */

	#define BATADV_NO_MARK 0

	/* default interface for multi interface operation. The default interface is
	* used for communication which originated locally (i.e. is not forwarded)
	* or where special forwarding is not desired/necessary.
	*/
	#define BATADV_IF_DEFAULT ((struct batadv_hard_iface *)NULL)

	#define BATADV_NUM_WORDS BITS_TO_LONGS(BATADV_TQ_LOCAL_WINDOW_SIZE)

	#define BATADV_LOG_BUF_LEN 8192 /* has to be a power of 2 */

	/* number of packets to send for broadcasts on different interface types */
	#define BATADV_NUM_BCASTS_DEFAULT 1
	#define BATADV_NUM_BCASTS_WIRELESS 3
	#define BATADV_NUM_BCASTS_MAX 3

	/* length of the single packet used by the TP meter */
	#define BATADV_TP_PACKET_LEN ETH_DATA_LEN

	/* msecs after which an ARP_REQUEST is sent in broadcast as fallback */
	#define ARP_REQ_DELAY 250
	/* numbers of originator to contact for any PUT/GET DHT operation */
	#define BATADV_DAT_CANDIDATES_NUM 3

	/* BATADV_TQ_SIMILARITY_THRESHOLD - TQ points that a secondary metric can differ
	* at most from the primary one in order to be still considered acceptable
	*/
	#define BATADV_TQ_SIMILARITY_THRESHOLD 50

	/* should not be bigger than 512 bytes or change the size of
	* forw_packet->direct_link_flags
	*/
	#define BATADV_MAX_AGGREGATION_BYTES 512
	#define BATADV_MAX_AGGREGATION_MS 100

	#define BATADV_BLA_PERIOD_LENGTH 10000 /* 10 seconds */
	#define BATADV_BLA_BACKBONE_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 6)
	#define BATADV_BLA_CLAIM_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 10)
	#define BATADV_BLA_WAIT_PERIODS 3
	#define BATADV_BLA_LOOPDETECT_PERIODS 6
	#define BATADV_BLA_LOOPDETECT_TIMEOUT 3000 /* 3 seconds */

	#define BATADV_DUPLIST_SIZE 16
	#define BATADV_DUPLIST_TIMEOUT 500 /* 500 ms */
	/* don't reset again within 30 seconds */
	#define BATADV_RESET_PROTECTION_MS 30000
	#define BATADV_EXPECTED_SEQNO_RANGE 65536

	#define BATADV_NC_NODE_TIMEOUT 10000 /* Milliseconds */

	/**
	* BATADV_TP_MAX_NUM - maximum number of simultaneously active tp sessions
	*/
	#define BATADV_TP_MAX_NUM 5

	enum batadv_mesh_state {
	BATADV_MESH_INACTIVE,
	BATADV_MESH_ACTIVE,
	BATADV_MESH_DEACTIVATING,
	};

	#define BATADV_BCAST_QUEUE_LEN 256
	#define BATADV_BATMAN_QUEUE_LEN 256

	enum batadv_uev_action {
	BATADV_UEV_ADD = 0,
	BATADV_UEV_DEL,
	BATADV_UEV_CHANGE,
	BATADV_UEV_LOOPDETECT,
	};

	enum batadv_uev_type {
	BATADV_UEV_GW = 0,
	BATADV_UEV_BLA,
	};

	#define BATADV_GW_THRESHOLD 50

	/* Number of fragment chains for each orig_node */
	#define BATADV_FRAG_BUFFER_COUNT 8
	/* Maximum number of fragments for one packet */
	#define BATADV_FRAG_MAX_FRAGMENTS 16
	/* Maxumim size of each fragment */
	#define BATADV_FRAG_MAX_FRAG_SIZE 1400
	/* Time to keep fragments while waiting for rest of the fragments */
	#define BATADV_FRAG_TIMEOUT 10000

	#define BATADV_DAT_CANDIDATE_NOT_FOUND 0
	#define BATADV_DAT_CANDIDATE_ORIG 1

	/* Debug Messages */
	#ifdef pr_fmt
	#undef pr_fmt
	#endif
	/* Append 'batman-adv: ' before kernel messages */
	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	/* Kernel headers */

	#include <linux/bitops.h> /* for packet.h */
	#include <linux/compiler.h>
	#include <linux/etherdevice.h>
	#include <linux/if_ether.h> /* for packet.h */
	#include <linux/if_vlan.h>
	#include <linux/jiffies.h>
	#include <linux/percpu.h>
	#include <linux/types.h>

	#include "types.h"

	struct net_device;
	struct packet_type;
	struct seq_file;
	struct sk_buff;

	#define BATADV_PRINT_VID(vid) (((vid) & BATADV_VLAN_HAS_TAG) ? \
	(int)((vid) & VLAN_VID_MASK) : -1)

	extern struct list_head batadv_hardif_list;

	extern unsigned char batadv_broadcast_addr[];
	extern struct workqueue_struct *batadv_event_workqueue;

	int batadv_mesh_init(struct net_device *soft_iface);
	void batadv_mesh_free(struct net_device *soft_iface);
	bool batadv_is_my_mac(struct batadv_priv bat_priv, const u8 addr);
	struct batadv_hard_iface *
	batadv_seq_print_text_primary_if_get(struct seq_file *seq);
	int batadv_max_header_len(void);
	void batadv_skb_set_priority(struct sk_buff *skb, int offset);
	int batadv_batman_skb_recv(struct sk_buff skb, struct net_device dev,
	struct packet_type *ptype,
	struct net_device *orig_dev);
	int
	batadv_recv_handler_register(u8 packet_type,
	int (recv_handler)(struct sk_buff ,
	struct batadv_hard_iface *));
	void batadv_recv_handler_unregister(u8 packet_type);
	__be32 batadv_skb_crc32(struct sk_buff skb, u8 payload_ptr);

	/**
	* batadv_compare_eth - Compare two not u16 aligned Ethernet addresses
	* @data1: Pointer to a six-byte array containing the Ethernet address
	* @data2: Pointer other six-byte array containing the Ethernet address
	*
	* note: can't use ether_addr_equal() as it requires aligned memory
	*
	* Return: true if they are the same ethernet addr
	*/
	static inline bool batadv_compare_eth(const void data1, const void data2)
	{
	return ether_addr_equal_unaligned(data1, data2);
	}

	/**
	* batadv_has_timed_out - compares current time (jiffies) and timestamp +
	* timeout
	* @timestamp: base value to compare with (in jiffies)
	* @timeout: added to base value before comparing (in milliseconds)
	*
	* Return: true if current time is after timestamp + timeout
	*/
	static inline bool batadv_has_timed_out(unsigned long timestamp,
	unsigned int timeout)
	{
	return time_is_before_jiffies(timestamp + msecs_to_jiffies(timeout));
	}

	#define batadv_atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0)

	/* Returns the smallest signed integer in two's complement with the sizeof x */
	#define batadv_smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))

	/* Checks if a sequence number x is a predecessor/successor of y.
	* they handle overflows/underflows and can correctly check for a
	* predecessor/successor unless the variable sequence number has grown by
	* more then 2**(bitwidth(x)-1)-1.
	* This means that for a u8 with the maximum value 255, it would think:
	* - when adding nothing - it is neither a predecessor nor a successor
	* - before adding more than 127 to the starting value - it is a predecessor,
	* - when adding 128 - it is neither a predecessor nor a successor,
	* - after adding more than 127 to the starting value - it is a successor
	*/
	#define batadv_seq_before(x, y) ({typeof(x)_d1 = (x); \
	typeof(y)_d2 = (y); \
	typeof(x)_dummy = (_d1 - _d2); \
	(void)(&_d1 == &_d2); \
	_dummy > batadv_smallest_signed_int(_dummy); })
	#define batadv_seq_after(x, y) batadv_seq_before(y, x)

	/* Stop preemption on local cpu while incrementing the counter */
	static inline void batadv_add_counter(struct batadv_priv *bat_priv, size_t idx,
	size_t count)
	{
	this_cpu_add(bat_priv->bat_counters[idx], count);
	}

	#define batadv_inc_counter(b, i) batadv_add_counter(b, i, 1)

	/* Define a macro to reach the control buffer of the skb. The members of the
	* control buffer are defined in struct batadv_skb_cb in types.h.
	* The macro is inspired by the similar macro TCP_SKB_CB() in tcp.h.
	*/
	#define BATADV_SKB_CB(__skb) ((struct batadv_skb_cb *)&((__skb)->cb[0]))

	unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len);
	bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid);

	#endif /* _NET_BATMAN_ADV_MAIN_H_ */