[U-Boot] [PATCH v7 2/4] net: use common rand()/srand() functions

Michael Walle michael at walle.cc
Thu May 31 20:12:43 CEST 2012


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 <michael at walle.cc>
Cc: Joe Hershberger <joe.hershberger at ni.com>
---
 include/configs/ETX094.h          |    1 +
 include/configs/MERGERBOX.h       |    1 +
 include/configs/MVBC_P.h          |    1 +
 include/configs/MVBLM7.h          |    1 +
 include/configs/MVSMR.h           |    1 +
 include/configs/bfin_adi_common.h |    1 +
 include/configs/sacsng.h          |    1 +
 net/Makefile                      |    2 -
 net/link_local.c                  |    7 ++--
 net/net_rand.c                    |   68 -------------------------------------
 net/net_rand.h                    |   32 +++++++++++++----
 11 files changed, 36 insertions(+), 80 deletions(-)
 delete mode 100644 net/net_rand.c

diff --git a/include/configs/ETX094.h b/include/configs/ETX094.h
index c427093..aee9915 100644
--- a/include/configs/ETX094.h
+++ b/include/configs/ETX094.h
@@ -54,6 +54,7 @@
 
 #define	CONFIG_FLASH_16BIT		/* for board with 16bit wide flash	*/
 #undef	SB_ETX094			/* only for SB-Board with 16MB SDRAM	*/
+#define CONFIG_RAND
 #define	CONFIG_BOOTP_RANDOM_DELAY	/* graceful BOOTP recovery mode		*/
 
 #define CONFIG_ETHADDR 08:00:06:00:00:00
diff --git a/include/configs/MERGERBOX.h b/include/configs/MERGERBOX.h
index 8176916..c2b962f 100644
--- a/include/configs/MERGERBOX.h
+++ b/include/configs/MERGERBOX.h
@@ -315,6 +315,7 @@
 /*
  * BOOTP options
  */
+#define CONFIG_RAND
 #define CONFIG_BOOTP_BOOTFILESIZE
 #define CONFIG_BOOTP_BOOTPATH
 #define CONFIG_BOOTP_GATEWAY
diff --git a/include/configs/MVBC_P.h b/include/configs/MVBC_P.h
index ade4893..d38da0b 100644
--- a/include/configs/MVBC_P.h
+++ b/include/configs/MVBC_P.h
@@ -110,6 +110,7 @@
 
 #undef CONFIG_WATCHDOG
 
+#define CONFIG_RAND
 #define CONFIG_BOOTP_VENDOREX
 #define CONFIG_BOOTP_SUBNETMASK
 #define CONFIG_BOOTP_GATEWAY
diff --git a/include/configs/MVBLM7.h b/include/configs/MVBLM7.h
index 8b20f72..7c8c808 100644
--- a/include/configs/MVBLM7.h
+++ b/include/configs/MVBLM7.h
@@ -232,6 +232,7 @@
 
 #define CONFIG_ETHPRIME		"TSEC0"
 
+#define CONFIG_RAND
 #define CONFIG_BOOTP_VENDOREX
 #define CONFIG_BOOTP_SUBNETMASK
 #define CONFIG_BOOTP_GATEWAY
diff --git a/include/configs/MVSMR.h b/include/configs/MVSMR.h
index f94ad5c..6f10907 100644
--- a/include/configs/MVSMR.h
+++ b/include/configs/MVSMR.h
@@ -98,6 +98,7 @@
 #define CONFIG_CMD_PING
 #define CONFIG_CMD_SDRAM
 
+#define CONFIG_RAND
 #define CONFIG_BOOTP_BOOTFILESIZE
 #define CONFIG_BOOTP_BOOTPATH
 #define CONFIG_BOOTP_DNS
diff --git a/include/configs/bfin_adi_common.h b/include/configs/bfin_adi_common.h
index 3fbf5c6..0f4c2d8 100644
--- a/include/configs/bfin_adi_common.h
+++ b/include/configs/bfin_adi_common.h
@@ -11,6 +11,7 @@
 #ifndef _CONFIG_CMD_DEFAULT_H
 # include <config_cmd_default.h>
 # if ADI_CMDS_NETWORK
+#  define CONFIG_RAND
 #  define CONFIG_CMD_DHCP
 #  define CONFIG_BOOTP_SUBNETMASK
 #  define CONFIG_BOOTP_GATEWAY
diff --git a/include/configs/sacsng.h b/include/configs/sacsng.h
index 43036b2..d604de3 100644
--- a/include/configs/sacsng.h
+++ b/include/configs/sacsng.h
@@ -475,6 +475,7 @@
 	"bootm"
 #endif /* CONFIG_BOOT_ROOT_NFS */
 
+#define CONFIG_RAND
 #define CONFIG_BOOTP_RANDOM_DELAY       /* Randomize the BOOTP retry delay */
 
 /*
diff --git a/net/Makefile b/net/Makefile
index 5264687..e7764ce 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 3362863..582d011 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 5387aba..0000000
--- 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 at denx.de
- */
-
-#include <common.h>
-#include <net.h>
-#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 c98db64..62de375 100644
--- a/net/net_rand.h
+++ b/net/net_rand.h
@@ -9,18 +9,36 @@
 #ifndef __NET_RAND_H__
 #define __NET_RAND_H__
 
-#define RAND_MAX 0xffffffff
+#include <common.h>
 
 /*
- * Seed the random number generator using the eth0 MAC address
+ * Return a seed for the PRNG derived from the timer and 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 = get_timer(0);
+	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 timer and the eth0 MAC address.
  */
-unsigned long rand(void);
+static inline void srand_mac(void)
+{
+	srand(seed_mac());
+}
 
 #endif /* __NET_RAND_H__ */
-- 
1.7.2.5



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