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 <dm/uclass.h> 13#include <rng.h> 14 15/* 16 * Return a seed for the PRNG derived from the eth0 MAC address. 17 */ 18static inline unsigned int seed_mac(void) 19{ 20 unsigned char enetaddr[ARP_HLEN]; 21 unsigned int seed; 22 23 /* get our mac */ 24 memcpy(enetaddr, eth_get_ethaddr(), ARP_HLEN); 25 26 seed = enetaddr[5]; 27 seed ^= enetaddr[4] << 8; 28 seed ^= enetaddr[3] << 16; 29 seed ^= enetaddr[2] << 24; 30 seed ^= enetaddr[1]; 31 seed ^= enetaddr[0] << 8; 32 33 return seed; 34} 35 36/* 37 * Seed the random number generator using the eth0 MAC address. 38 */ 39static inline void srand_mac(void) 40{ 41 int ret; 42 struct udevice *devp; 43 u32 randv = 0; 44 45 if (IS_ENABLED(CONFIG_DM_RNG)) { 46 ret = uclass_get_device(UCLASS_RNG, 0, &devp); 47 if (ret) { 48 ret = dm_rng_read(devp, &randv, sizeof(randv)); 49 if (ret < 0) 50 randv = 0; 51 } 52 } 53 if (randv) 54 srand(randv); 55 else 56 srand(seed_mac()); 57} 58 59#endif /* __NET_RAND_H__ */ 60