From 99e139d5902e488eb779cd4f00c978f3803c39be Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 5 Jun 2012 11:33:15 +0000 Subject: net: use common rand()/srand() functions Replace rand() with the functions from lib/. The link-local network code stores its own seed, derived from the MAC address. Thus making it independent from calls to srand() in other modules. Signed-off-by: Michael Walle Acked-by: Joe Hershberger --- net/net_rand.h | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'net/net_rand.h') diff --git a/net/net_rand.h b/net/net_rand.h index c98db642805..ba9d0642cf2 100644 --- a/net/net_rand.h +++ b/net/net_rand.h @@ -9,18 +9,35 @@ #ifndef __NET_RAND_H__ #define __NET_RAND_H__ -#define RAND_MAX 0xffffffff +#include /* - * Seed the random number generator using the eth0 MAC address + * Return a seed for the PRNG derived from the eth0 MAC address. */ -void srand_mac(void); +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; +} /* - * Get a random number (after seeding with MAC address) - * - * @return random number + * Seed the random number generator using the eth0 MAC address. */ -unsigned long rand(void); +static inline void srand_mac(void) +{ + srand(seed_mac()); +} #endif /* __NET_RAND_H__ */ -- cgit