From 99e139d5902e488eb779cd4f00c978f3803c39be Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 5 Jun 2012 11:33:15 +0000 Subject: [PATCH] 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 --- include/common.h | 4 ++- lib/Makefile | 4 ++- net/Makefile | 2 -- net/link_local.c | 7 ++--- net/net_rand.c | 68 ------------------------------------------------ net/net_rand.h | 31 +++++++++++++++++----- 6 files changed, 34 insertions(+), 82 deletions(-) delete mode 100644 net/net_rand.c diff --git a/include/common.h b/include/common.h index e16c53e538..d1dd65a851 100644 --- a/include/common.h +++ b/include/common.h @@ -761,7 +761,9 @@ char * strmhz(char *buf, unsigned long hz); #include /* lib/rand.c */ -#ifdef CONFIG_RANDOM_MACADDR +#if defined(CONFIG_RANDOM_MACADDR) || \ + defined(CONFIG_BOOTP_RANDOM_DELAY) || \ + defined(CONFIG_CMD_LINK_LOCAL) #define RAND_MAX -1U void srand(unsigned int seed); unsigned int rand(void); diff --git a/lib/Makefile b/lib/Makefile index 0ca45fc1e9..556601c291 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -67,8 +67,10 @@ COBJS-y += time.o COBJS-$(CONFIG_BOOTP_PXE) += uuid.o COBJS-y += vsprintf.o COBJS-$(CONFIG_RANDOM_MACADDR) += rand.o +COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += rand.o +COBJS-$(CONFIG_CMD_LINK_LOCAL) += rand.o -COBJS := $(COBJS-y) +COBJS := $(sort $(COBJS-y)) SRCS := $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(COBJS)) diff --git a/net/Makefile b/net/Makefile index 526468718a..e7764ce932 100644 --- a/net/Makefile +++ b/net/Makefile @@ -34,8 +34,6 @@ COBJS-$(CONFIG_CMD_DNS) += dns.o COBJS-$(CONFIG_CMD_NET) += eth.o COBJS-$(CONFIG_CMD_LINK_LOCAL) += link_local.o COBJS-$(CONFIG_CMD_NET) += net.o -COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += net_rand.o -COBJS-$(CONFIG_CMD_LINK_LOCAL) += net_rand.o COBJS-$(CONFIG_CMD_NFS) += nfs.o COBJS-$(CONFIG_CMD_PING) += ping.o COBJS-$(CONFIG_CMD_RARP) += rarp.o diff --git a/net/link_local.c b/net/link_local.c index 336286395b..582d0115b7 100644 --- a/net/link_local.c +++ b/net/link_local.c @@ -56,6 +56,7 @@ static unsigned conflicts; static unsigned nprobes; static unsigned nclaims; static int ready; +static unsigned int seed; static void link_local_timeout(void); @@ -68,7 +69,7 @@ static IPaddr_t pick(void) unsigned tmp; do { - tmp = rand() & IN_CLASSB_HOST; + tmp = rand_r(&seed) & IN_CLASSB_HOST; } while (tmp > (IN_CLASSB_HOST - 0x0200)); return (IPaddr_t) htonl((LINKLOCAL_ADDR + 0x0100) + tmp); } @@ -78,7 +79,7 @@ static IPaddr_t pick(void) */ static inline unsigned random_delay_ms(unsigned secs) { - return rand() % (secs * 1000); + return rand_r(&seed) % (secs * 1000); } static void configure_wait(void) @@ -109,7 +110,7 @@ void link_local_start(void) } NetOurSubnetMask = IN_CLASSB_NET; - srand_mac(); + seed = seed_mac(); if (ip == 0) ip = pick(); diff --git a/net/net_rand.c b/net/net_rand.c deleted file mode 100644 index 5387abadcf..0000000000 --- a/net/net_rand.c +++ /dev/null @@ -1,68 +0,0 @@ -/* - * Based on LiMon - BOOTP. - * - * Copyright 1994, 1995, 2000 Neil Russell. - * (See License) - * Copyright 2000 Roland Borde - * Copyright 2000 Paolo Scaffardi - * Copyright 2000-2004 Wolfgang Denk, wd@denx.de - */ - -#include -#include -#include "net_rand.h" - -static ulong seed1, seed2; - -void srand_mac(void) -{ - ulong tst1, tst2, m_mask; - ulong m_value = 0; - int reg; - unsigned char bi_enetaddr[6]; - - /* get our mac */ - eth_getenv_enetaddr("ethaddr", bi_enetaddr); - - debug("BootpRequest => Our Mac: "); - for (reg = 0; reg < 6; reg++) - debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':'); - - /* Mac-Manipulation 2 get seed1 */ - tst1 = 0; - tst2 = 0; - for (reg = 2; reg < 6; reg++) { - tst1 = tst1 << 8; - tst1 = tst1 | bi_enetaddr[reg]; - } - for (reg = 0; reg < 2; reg++) { - tst2 = tst2 | bi_enetaddr[reg]; - tst2 = tst2 << 8; - } - - seed1 = tst1^tst2; - - /* Mirror seed1*/ - m_mask = 0x1; - for (reg = 1; reg <= 32; reg++) { - m_value |= (m_mask & seed1); - seed1 = seed1 >> 1; - m_value = m_value << 1; - } - seed1 = m_value; - seed2 = 0xb78d0945; -} - -unsigned long rand(void) -{ - ulong sum; - - /* Random Number Generator */ - sum = seed1 + seed2; - if (sum < seed1 || sum < seed2) - sum++; - seed2 = seed1; - seed1 = sum; - - return sum; -} diff --git a/net/net_rand.h b/net/net_rand.h index c98db64280..ba9d0642cf 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__ */ -- 2.30.2