[people/ms/u-boot.git] / net / net_rand.h

/*
 *	Copied from LiMon - BOOTP.
 *
 *	Copyright 1994, 1995, 2000 Neil Russell.
 *	(See License)
 *	Copyright 2000 Paolo Scaffardi
 */

#ifndef __NET_RAND_H__
#define __NET_RAND_H__

#include <common.h>

/*
 * Return a seed for the PRNG derived from the eth0 MAC address.
 */
static inline unsigned int seed_mac(void)
{
	unsigned char enetaddr[6];
	unsigned int seed;

	/* get our mac */
	eth_getenv_enetaddr("ethaddr", enetaddr);

	seed = enetaddr[5];
	seed ^= enetaddr[4] << 8;
	seed ^= enetaddr[3] << 16;
	seed ^= enetaddr[2] << 24;
	seed ^= enetaddr[1];
	seed ^= enetaddr[0] << 8;

	return seed;
}

/*
 * Seed the random number generator using the eth0 MAC address.
 */
static inline void srand_mac(void)
{
	srand(seed_mac());
}

#endif /* __NET_RAND_H__ */
Commit	Line	Data
	1	/*
	2	* Copied from LiMon - BOOTP.
	3	*
	4	* Copyright 1994, 1995, 2000 Neil Russell.
	5	* (See License)
	6	* Copyright 2000 Paolo Scaffardi
	7	*/
	8
	9	#ifndef __NET_RAND_H__
	10	#define __NET_RAND_H__
	11
	12	#include <common.h>
	13
	14	/*
	15	* Return a seed for the PRNG derived from the eth0 MAC address.
	16	*/
	17	static inline unsigned int seed_mac(void)
	18	{
	19	unsigned char enetaddr[6];
	20	unsigned int seed;
	21
	22	/* get our mac */
	23	eth_getenv_enetaddr("ethaddr", enetaddr);
	24
	25	seed = enetaddr[5];
	26	seed ^= enetaddr[4] << 8;
	27	seed ^= enetaddr[3] << 16;
	28	seed ^= enetaddr[2] << 24;
	29	seed ^= enetaddr[1];
	30	seed ^= enetaddr[0] << 8;
	31
	32	return seed;
	33	}
	34
	35	/*
	36	* Seed the random number generator using the eth0 MAC address.
	37	*/
	38	static inline void srand_mac(void)
	39	{
	40	srand(seed_mac());
	41	}
	42
	43	#endif /* __NET_RAND_H__ */