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__ */ 44