/* Please avoid adding hacks here - instead add it to mac80211/backports.git */

#undef CONFIG_MODULE_STRIPPED

#include <linux/version.h>	/* LINUX_VERSION_CODE */
#include <linux/types.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 1, 0)

#define dev_get_iflink(_net_dev) ((_net_dev)->iflink)

#endif /* < KERNEL_VERSION(4, 1, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 16, 0)

/* Linux 3.15 misses the uapi include.... */
#include <uapi/linux/nl80211.h>

#endif /* < KERNEL_VERSION(3, 16, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 9, 0)

#include <linux/netdevice.h>

#define netdev_master_upper_dev_link(dev, upper_dev, upper_priv, upper_info) ({\
	BUILD_BUG_ON(upper_priv != NULL); \
	BUILD_BUG_ON(upper_info != NULL); \
	netdev_set_master(dev, upper_dev); \
})

#elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0)

#include <linux/netdevice.h>

#define netdev_master_upper_dev_link(dev, upper_dev, upper_priv, upper_info) ({\
	BUILD_BUG_ON(upper_priv != NULL); \
	BUILD_BUG_ON(upper_info != NULL); \
	netdev_master_upper_dev_link(dev, upper_dev); \
})

#endif /* < KERNEL_VERSION(4, 5, 0) */


#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)

/* for batadv_v_elp_get_throughput which would have used
 * STATION_INFO_EXPECTED_THROUGHPUT in Linux 4.0.0
 */
#define NL80211_STA_INFO_EXPECTED_THROUGHPUT    28

/* wild hack for batadv_getlink_net only */
#define get_link_net get_xstats_size || 1 ? fallback_net : (struct net*)netdev->rtnl_link_ops->get_xstats_size

#endif /* < KERNEL_VERSION(4, 0, 0) */


#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0)

struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
				     unsigned int transport_len,
				     __sum16(*skb_chkf)(struct sk_buff *skb));

int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed);

int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed);

#endif /* < KERNEL_VERSION(4, 2, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)

#define IFF_NO_QUEUE	0; dev->tx_queue_len = 0

static inline bool hlist_fake(struct hlist_node *h)
{
	return h->pprev == &h->next;
}

#endif /* < KERNEL_VERSION(4, 3, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 6, 0)

#include <linux/ethtool.h>

#define ethtool_link_ksettings batadv_ethtool_link_ksettings

struct batadv_ethtool_link_ksettings {
	struct {
		__u32	speed;
		__u8	duplex;
	} base;
};

#define __ethtool_get_link_ksettings(__dev, __link_settings) \
	batadv_ethtool_get_link_ksettings(__dev, __link_settings)

static inline int
batadv_ethtool_get_link_ksettings(struct net_device *dev,
				  struct ethtool_link_ksettings *link_ksettings)
{
	struct ethtool_cmd cmd;
	int ret;

	memset(&cmd, 0, sizeof(cmd));
	ret = __ethtool_get_settings(dev, &cmd);

	if (ret != 0)
		return ret;

	link_ksettings->base.duplex = cmd.duplex;
	link_ksettings->base.speed = ethtool_cmd_speed(&cmd);

	return 0;
}

#endif /* < KERNEL_VERSION(4, 6, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 7, 0)

#define netif_trans_update batadv_netif_trans_update
static inline void batadv_netif_trans_update(struct net_device *dev)
{
	dev->trans_start = jiffies;
}

#endif /* < KERNEL_VERSION(4, 7, 0) */


#include_next <linux/netlink.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 7, 0)

#include_next <net/netlink.h>

static inline bool batadv_nla_need_padding_for_64bit(struct sk_buff *skb);

static inline int batadv_nla_align_64bit(struct sk_buff *skb, int padattr)
{
	if (batadv_nla_need_padding_for_64bit(skb) &&
	    !nla_reserve(skb, padattr, 0))
		return -EMSGSIZE;

	return 0;
}

static inline struct nlattr *batadv__nla_reserve_64bit(struct sk_buff *skb,
						       int attrtype,
						       int attrlen, int padattr)
{
	if (batadv_nla_need_padding_for_64bit(skb))
		batadv_nla_align_64bit(skb, padattr);

	return __nla_reserve(skb, attrtype, attrlen);
}

static inline void batadv__nla_put_64bit(struct sk_buff *skb, int attrtype,
					 int attrlen, const void *data,
					 int padattr)
{
	struct nlattr *nla;

	nla = batadv__nla_reserve_64bit(skb, attrtype, attrlen, padattr);
	memcpy(nla_data(nla), data, attrlen);
}

static inline bool batadv_nla_need_padding_for_64bit(struct sk_buff *skb)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	/* The nlattr header is 4 bytes in size, that's why we test
	 * if the skb->data _is_ aligned.  A NOP attribute, plus
	 * nlattr header for next attribute, will make nla_data()
	 * 8-byte aligned.
	 */
	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
		return true;
#endif
	return false;
}

static inline int batadv_nla_total_size_64bit(int payload)
{
	return NLA_ALIGN(nla_attr_size(payload))
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
		+ NLA_ALIGN(nla_attr_size(0))
#endif
		;
}

static inline int batadv_nla_put_64bit(struct sk_buff *skb, int attrtype,
				       int attrlen, const void *data,
				       int padattr)
{
	size_t len;

	if (batadv_nla_need_padding_for_64bit(skb))
		len = batadv_nla_total_size_64bit(attrlen);
	else
		len = nla_total_size(attrlen);
	if (unlikely(skb_tailroom(skb) < len))
		return -EMSGSIZE;

	batadv__nla_put_64bit(skb, attrtype, attrlen, data, padattr);
	return 0;
}

#define nla_put_u64_64bit(_skb, _attrtype, _value, _padattr) \
	batadv_nla_put_u64_64bit(_skb, _attrtype, _value, _padattr)
static inline int batadv_nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
					   u64 value, int padattr)
{
	return batadv_nla_put_64bit(skb, attrtype, sizeof(u64), &value,
				    padattr);
}

#endif /* < KERNEL_VERSION(4, 7, 0) */


#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)

#include_next <linux/cache.h>

/* hack for netlink.c which marked the family ops as ro */
#ifdef __ro_after_init
#undef __ro_after_init
#endif
#define __ro_after_init

#endif /* < KERNEL_VERSION(4, 10, 0) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 9)

/* work around missing attribute needs_free_netdev and priv_destructor in
 * net_device
 */
#define ether_setup(dev) \
	void batadv_softif_free2(struct net_device *dev) \
	{ \
		batadv_softif_free(dev); \
		free_netdev(dev); \
	} \
	void (*t1)(struct net_device *dev) __attribute__((unused)); \
	bool t2 __attribute__((unused)); \
	ether_setup(dev)
#define needs_free_netdev destructor = batadv_softif_free2; t2
#define priv_destructor destructor = batadv_softif_free2; t1

#endif /* < KERNEL_VERSION(4, 11, 9) */

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0)

static inline void *batadv_skb_put(struct sk_buff *skb, unsigned int len)
{
	return (void *)skb_put(skb, len);
}
#define skb_put batadv_skb_put

static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
{
	void *tmp = skb_put(skb, len);

	memset(tmp, 0, len);

	return tmp;
}

static inline void *skb_put_data(struct sk_buff *skb, const void *data,
				 unsigned int len)
{
	void *tmp = skb_put(skb, len);

	memcpy(tmp, data, len);

	return tmp;
}

#endif /* < KERNEL_VERSION(4, 13, 0) */

/* <DECLARE_EWMA> */

#include <linux/version.h>
#include_next <linux/average.h>

#include <linux/bug.h>

#ifdef DECLARE_EWMA
#undef DECLARE_EWMA
#endif /* DECLARE_EWMA */

/*
 * Exponentially weighted moving average (EWMA)
 *
 * This implements a fixed-precision EWMA algorithm, with both the
 * precision and fall-off coefficient determined at compile-time
 * and built into the generated helper funtions.
 *
 * The first argument to the macro is the name that will be used
 * for the struct and helper functions.
 *
 * The second argument, the precision, expresses how many bits are
 * used for the fractional part of the fixed-precision values.
 *
 * The third argument, the weight reciprocal, determines how the
 * new values will be weighed vs. the old state, new values will
 * get weight 1/weight_rcp and old values 1-1/weight_rcp. Note
 * that this parameter must be a power of two for efficiency.
 */

#define DECLARE_EWMA(name, _precision, _weight_rcp)			\
	struct ewma_##name {						\
		unsigned long internal;					\
	};								\
	static inline void ewma_##name##_init(struct ewma_##name *e)	\
	{								\
		BUILD_BUG_ON(!__builtin_constant_p(_precision));	\
		BUILD_BUG_ON(!__builtin_constant_p(_weight_rcp));	\
		/*							\
		 * Even if you want to feed it just 0/1 you should have	\
		 * some bits for the non-fractional part...		\
		 */							\
		BUILD_BUG_ON((_precision) > 30);			\
		BUILD_BUG_ON_NOT_POWER_OF_2(_weight_rcp);		\
		e->internal = 0;					\
	}								\
	static inline unsigned long					\
	ewma_##name##_read(struct ewma_##name *e)			\
	{								\
		BUILD_BUG_ON(!__builtin_constant_p(_precision));	\
		BUILD_BUG_ON(!__builtin_constant_p(_weight_rcp));	\
		BUILD_BUG_ON((_precision) > 30);			\
		BUILD_BUG_ON_NOT_POWER_OF_2(_weight_rcp);		\
		return e->internal >> (_precision);			\
	}								\
	static inline void ewma_##name##_add(struct ewma_##name *e,	\
					     unsigned long val)		\
	{								\
		unsigned long internal = ACCESS_ONCE(e->internal);	\
		unsigned long weight_rcp = ilog2(_weight_rcp);		\
		unsigned long precision = _precision;			\
									\
		BUILD_BUG_ON(!__builtin_constant_p(_precision));	\
		BUILD_BUG_ON(!__builtin_constant_p(_weight_rcp));	\
		BUILD_BUG_ON((_precision) > 30);			\
		BUILD_BUG_ON_NOT_POWER_OF_2(_weight_rcp);		\
									\
		ACCESS_ONCE(e->internal) = internal ?			\
			(((internal << weight_rcp) - internal) +	\
				(val << precision)) >> weight_rcp :	\
			(val << precision);				\
	}

/* </DECLARE_EWMA> */