/* Copyright 2015-2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */

#ifndef COMPAT_H
#define COMPAT_H

#include <linux/kconfig.h>
#include <linux/version.h>
#include <linux/types.h>
#include <linux/netdevice.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 1, 0)
#error "WireGuard requires Linux >= 4.1"
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0) && !defined(DEBUG) && defined(net_dbg_ratelimited)
#undef net_dbg_ratelimited
#define net_dbg_ratelimited(fmt, ...) do { if (0) no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0)
#define get_random_long() (((u64)get_random_int() << 32) | get_random_int())
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
#define RCU_LOCKDEP_WARN(cond, message) rcu_lockdep_assert(!(cond), message)
#endif

/* https://lkml.org/lkml/2016/9/28/904
 * 64-bit jiffy functions like in include/linux/jiffies.h */
#define time_is_before_jiffies64(a) time_after64(get_jiffies_64(), a)
#define time_is_after_jiffies64(a) time_before64(get_jiffies_64(), a)
#define time_is_before_eq_jiffies64(a) time_after_eq64(get_jiffies_64(), a)
#define time_is_after_eq_jiffies64(a) time_before_eq64(get_jiffies_64(), a)

/* https://lkml.org/lkml/2015/6/12/415
 * Inverse of netdev_priv in include/linux/netdevice.h */
static inline struct net_device *netdev_pub(void *dev)
{
	return (struct net_device *)((char *)dev - ALIGN(sizeof(struct net_device), NETDEV_ALIGN));
}
#endif